From ecc03ac3126626f178a183cac77722b81f244569 Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Fri, 19 Jan 2024 15:41:55 +0100 Subject: [PATCH 1/8] Enhancing catalog for support session variables and related support This patch introduces new system catalog table pg_variable. This table holds metadata about session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE. Both commands are implemented by this patch. Possibility to change owner, schema or rename. Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are introduced by this patch too. This patch enhancing pg_dump and psql to support session variables. The changes are related to system catalog. This patch is not short, but the code is simple. --- doc/src/sgml/catalogs.sgml | 121 +++++ doc/src/sgml/ddl.sgml | 40 +- doc/src/sgml/func.sgml | 32 ++ doc/src/sgml/glossary.sgml | 15 + doc/src/sgml/ref/allfiles.sgml | 3 + .../sgml/ref/alter_default_privileges.sgml | 29 +- doc/src/sgml/ref/alter_variable.sgml | 178 +++++++ doc/src/sgml/ref/comment.sgml | 1 + doc/src/sgml/ref/create_schema.sgml | 12 +- doc/src/sgml/ref/create_variable.sgml | 149 ++++++ doc/src/sgml/ref/drop_variable.sgml | 117 +++++ doc/src/sgml/ref/grant.sgml | 20 +- doc/src/sgml/ref/psql-ref.sgml | 13 + doc/src/sgml/ref/revoke.sgml | 8 + doc/src/sgml/reference.sgml | 3 + src/backend/catalog/Makefile | 1 + src/backend/catalog/aclchk.c | 76 +++ src/backend/catalog/dependency.c | 6 + src/backend/catalog/meson.build | 1 + src/backend/catalog/namespace.c | 221 +++++++++ src/backend/catalog/objectaddress.c | 121 ++++- src/backend/catalog/pg_shdepend.c | 2 + src/backend/catalog/pg_variable.c | 251 ++++++++++ src/backend/commands/alter.c | 9 + src/backend/commands/dropcmds.c | 4 + src/backend/commands/event_trigger.c | 4 + src/backend/commands/seclabel.c | 1 + src/backend/commands/tablecmds.c | 41 ++ src/backend/commands/typecmds.c | 15 + src/backend/parser/gram.y | 105 ++++- src/backend/parser/parse_utilcmd.c | 12 + src/backend/tcop/utility.c | 20 + src/backend/utils/adt/acl.c | 221 +++++++++ src/backend/utils/cache/lsyscache.c | 113 +++++ src/bin/pg_dump/common.c | 3 + src/bin/pg_dump/dumputils.c | 6 + src/bin/pg_dump/pg_backup.h | 2 + src/bin/pg_dump/pg_backup_archiver.c | 9 + src/bin/pg_dump/pg_dump.c | 190 ++++++++ src/bin/pg_dump/pg_dump.h | 15 + src/bin/pg_dump/pg_dump_sort.c | 7 + src/bin/pg_dump/t/002_pg_dump.pl | 64 +++ src/bin/psql/command.c | 3 + src/bin/psql/describe.c | 100 +++- src/bin/psql/describe.h | 3 + src/bin/psql/help.c | 1 + src/bin/psql/tab-complete.in.c | 45 +- src/include/catalog/Makefile | 3 +- src/include/catalog/meson.build | 1 + src/include/catalog/namespace.h | 6 + src/include/catalog/pg_default_acl.h | 1 + src/include/catalog/pg_proc.dat | 23 + src/include/catalog/pg_variable.h | 81 ++++ src/include/nodes/parsenodes.h | 16 + src/include/parser/kwlist.h | 2 + src/include/tcop/cmdtaglist.h | 3 + src/include/utils/acl.h | 1 + src/include/utils/lsyscache.h | 9 + src/test/regress/expected/dependency.out | 17 + src/test/regress/expected/oidjoins.out | 4 + src/test/regress/expected/psql.out | 50 ++ .../regress/expected/session_variables.out | 433 ++++++++++++++++++ src/test/regress/parallel_schedule | 2 +- src/test/regress/sql/dependency.sql | 14 + src/test/regress/sql/psql.sql | 21 + src/test/regress/sql/session_variables.sql | 297 ++++++++++++ src/tools/pgindent/typedefs.list | 4 + 67 files changed, 3366 insertions(+), 35 deletions(-) create mode 100644 doc/src/sgml/ref/alter_variable.sgml create mode 100644 doc/src/sgml/ref/create_variable.sgml create mode 100644 doc/src/sgml/ref/drop_variable.sgml create mode 100644 src/backend/catalog/pg_variable.c create mode 100644 src/include/catalog/pg_variable.h create mode 100644 src/test/regress/expected/session_variables.out create mode 100644 src/test/regress/sql/session_variables.sql diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index cbd4e40a320b..fc5623617926 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -369,6 +369,11 @@ pg_user_mapping mappings of users to foreign servers + + + pg_variable + session variables + @@ -3362,6 +3367,7 @@ SCRAM-SHA-256$<iteration count>:&l T = type, n = schema, L = large object + V = session variable @@ -9779,4 +9785,119 @@ SCRAM-SHA-256$<iteration count>:&l + + <structname>pg_variable</structname> + + + pg_variable + + + + The catalog pg_variable stores information about + session variables. + + + + <structname>pg_variable</structname> Columns + + + + + Column Type + + + Description + + + + + + + + oid oid + + + Row identifier + + + + + + vartype oid + (references pg_type.oid) + + + The OID of the variable's data type + + + + + + varname name + + + Name of the session variable + + + + + + varnamespace oid + (references pg_namespace.oid) + + + The OID of the namespace that contains this variable + + + + + + varowner oid + (references pg_authid.oid) + + + Owner of the variable + + + + + + vartypmod int4 + + + vartypmod records type-specific data + supplied at variable creation time (for example, the maximum + length of a varchar column). It is passed to + type-specific input functions and length coercion functions. + The value will generally be -1 for types that do not need vartypmod. + + + + + + varcollation oid + (references pg_collation.oid) + + + The defined collation of the variable, or zero if the variable is + not of a collatable data type. + + + + + + varacl aclitem[] + + + Access privileges; see + and + + for details + + + + + +
+ diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index fcd1cb85352f..66fa267faccb 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -2015,6 +2015,7 @@ REVOKE ALL ON accounts FROM PUBLIC; For sequences, this privilege also allows use of the currval function. For large objects, this privilege allows the object to be read. + For session variables, this privilege allows the object to be read. @@ -2050,6 +2051,8 @@ REVOKE ALL ON accounts FROM PUBLIC; setval functions. For large objects, this privilege allows writing or truncating the object. + For session variables, this privilege allows to set a value to the + object. @@ -2293,7 +2296,8 @@ REVOKE ALL ON accounts FROM PUBLIC; LARGE OBJECT, SEQUENCE, TABLE (and table-like objects), - table column + table column, + SESSION VARIABLE @@ -2308,7 +2312,8 @@ REVOKE ALL ON accounts FROM PUBLIC; LARGE OBJECT, SEQUENCE, TABLE, - table column + table column, + SESSION VARIABLE @@ -2495,6 +2500,12 @@ REVOKE ALL ON accounts FROM PUBLIC; U \dT+ + + SESSION VARIABLE + rw + none + \dV+ + @@ -5351,6 +5362,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01'; + + Session Variables + + + Session variables + + + + session variable + + + + Session variables are database objects that can hold a value. + Session variables, like relations, exist within a schema and their access + is controlled via GRANT and REVOKE + commands. A session variable can be created by the CREATE + VARIABLE command. + + + + The session variable holds value in session memory. This value is private + to each session and is released when the session ends. + + + Other Database Objects diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 574a544d9fa4..e23dfa45bf93 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -25602,6 +25602,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute'); + + + + has_session_variable_privilege + + has_session_variable_privilege ( + user name or oid, + session_variable text or oid, + privilege text ) + boolean + + + Does user have privilege for session variable? + Allowable privilege types are + SELECT, and + UPDATE. + + + @@ -26110,6 +26129,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid); Is type (or domain) visible in search path? + + + + + pg_variable_is_visible + + pg_variable_is_visible ( variable oid ) + boolean + + + Is session variable visible in search path? + + diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml index b88cac598e90..83b13f98f28e 100644 --- a/doc/src/sgml/glossary.sgml +++ b/doc/src/sgml/glossary.sgml @@ -1708,6 +1708,21 @@ + + Session variable + + + A persistent database object that holds a value in session memory. This + value is private to each session and is released when the session ends. + Read or write access to session variables is controlled by privileges, + similar to other database objects. + + + For more information, see . + + + + Shared memory diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml index f5be638867ab..2f67de3e21b6 100644 --- a/doc/src/sgml/ref/allfiles.sgml +++ b/doc/src/sgml/ref/allfiles.sgml @@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory. + @@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory. + @@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory. + diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml index 6acd0f1df914..bc73817061fe 100644 --- a/doc/src/sgml/ref/alter_default_privileges.sgml +++ b/doc/src/sgml/ref/alter_default_privileges.sgml @@ -56,6 +56,11 @@ GRANT { { SELECT | UPDATE } ON LARGE OBJECTS TO { [ GROUP ] role_name | PUBLIC } [, ...] [ WITH GRANT OPTION ] +GRANT { { SELECT | UPDATE } + [, ...] | ALL [ PRIVILEGES ] } + ON VARIABLES + TO { [ GROUP ] role_name | PUBLIC } [, ...] [ WITH GRANT OPTION ] + REVOKE [ GRANT OPTION FOR ] { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN } [, ...] | ALL [ PRIVILEGES ] } @@ -95,6 +100,14 @@ REVOKE [ GRANT OPTION FOR ] ON LARGE OBJECTS FROM { [ GROUP ] role_name | PUBLIC } [, ...] [ CASCADE | RESTRICT ] + +REVOKE [ GRANT OPTION FOR ] + { { SELECT | UPDATE } + [, ...] | ALL [ PRIVILEGES ] } + { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] } + ON VARIABLES + FROM { [ GROUP ] role_name | PUBLIC } [, ...] + [ CASCADE | RESTRICT ] @@ -129,14 +142,14 @@ REVOKE [ GRANT OPTION FOR ] Currently, only the privileges for schemas, tables (including views and foreign - tables), sequences, functions, types (including domains), and large objects - can be altered. For this command, functions include aggregates and procedures. - The words FUNCTIONS and ROUTINES are - equivalent in this command. (ROUTINES is preferred - going forward as the standard term for functions and procedures taken - together. In earlier PostgreSQL releases, only the - word FUNCTIONS was allowed. It is not possible to set - default privileges for functions and procedures separately.) + tables), sequences, functions, types (including domains), large objects + and session variables can be altered. For this command, functions include + aggregates and procedures. The words FUNCTIONS and + ROUTINES are equivalent in this command. + (ROUTINES is preferred going forward as the standard term + for functions and procedures taken together. In earlier PostgreSQL releases, + only the word FUNCTIONS was allowed. It is not possible + to set default privileges for functions and procedures separately.) diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml new file mode 100644 index 000000000000..96d2586423e4 --- /dev/null +++ b/doc/src/sgml/ref/alter_variable.sgml @@ -0,0 +1,178 @@ + + + + + ALTER VARIABLE + + + + session variable + altering + + + + ALTER VARIABLE + 7 + SQL - Language Statements + + + + ALTER VARIABLE + + change the definition of a session variable + + + + + +ALTER VARIABLE name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER } +ALTER VARIABLE name RENAME TO new_name +ALTER VARIABLE name SET SCHEMA new_schema + + + + + Description + + + The ALTER VARIABLE command changes the definition of an + existing session variable. There are several subforms: + + + + OWNER + + + This form changes the owner of the session variable. + + + + + + RENAME + + + This form changes the name of the session variable. + + + + + + SET SCHEMA + + + This form moves the session variable into another schema. + + + + + + + + + Only the owner or a superuser is allowed to alter a session variable. + In order to move a session variable from one schema to another, the user + must also have the CREATE privilege on the new schema (or + be a superuser). + + In order to move the session variable ownership from one role to another, + the user must also be a direct or indirect member of the new + owning role, and that role must have the CREATE privilege + on the session variable's schema (or be a superuser). These restrictions + enforce that altering the owner doesn't do anything you couldn't do by + dropping and recreating the session variable. + + + + + Parameters + + + + + name + + + The name (possibly schema-qualified) of the existing session variable + to alter. + + + + + + new_owner + + + The user name of the new owner of the session variable. + + + + + + new_name + + + The new name for the session variable. + + + + + + new_schema + + + The new schema for the session variable. + + + + + + + + + Examples + + + To rename a session variable: + +ALTER VARIABLE foo RENAME TO boo; + + + + + To change the owner of the session variable boo to + joe: + +ALTER VARIABLE boo OWNER TO joe; + + + + + To change the schema of the session variable boo to + private: + +ALTER VARIABLE boo SET SCHEMA private; + + + + + + Compatibility + + + Session variables and this command in particular are a PostgreSQL extension. + + + + + See Also + + + + + + + diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml index 5b43c56b1335..21cd80818fbe 100644 --- a/doc/src/sgml/ref/comment.sgml +++ b/doc/src/sgml/ref/comment.sgml @@ -65,6 +65,7 @@ COMMENT ON TRANSFORM FOR type_name LANGUAGE lang_name | TRIGGER trigger_name ON table_name | TYPE object_name | + VARIABLE object_name | VIEW object_name } IS { string_literal | NULL } diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml index ed69298ccc6c..d2bb265209b1 100644 --- a/doc/src/sgml/ref/create_schema.sgml +++ b/doc/src/sgml/ref/create_schema.sgml @@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION role_sp schema. Currently, only CREATE TABLE, CREATE VIEW, CREATE INDEX, CREATE SEQUENCE, CREATE - TRIGGER and GRANT are accepted as clauses - within CREATE SCHEMA. Other kinds of objects may - be created in separate commands after the schema is created. + TRIGGER, GRANT and CREATE + VARIABLE are accepted as clauses within CREATE + SCHEMA. Other kinds of objects may be created in separate + commands after the schema is created. @@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS The IF NOT EXISTS option is a PostgreSQL extension. + + + The CREATE VARIABLE command is a + PostgreSQL extension. + diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml new file mode 100644 index 000000000000..6e988f2e4729 --- /dev/null +++ b/doc/src/sgml/ref/create_variable.sgml @@ -0,0 +1,149 @@ + + + + + CREATE VARIABLE + + + + session variable + defining + + + + CREATE VARIABLE + 7 + SQL - Language Statements + + + + CREATE VARIABLE + define a session variable + + + + +CREATE VARIABLE [ IF NOT EXISTS ] name [ AS ] data_type [ COLLATE collation ] + + + + Description + + + The CREATE VARIABLE command creates a session variable. + Session variables, like relations, exist within a schema and their access is + controlled via the commands GRANT and REVOKE. + + + + The value of a session variable is local to the current session. Retrieving + a session variable's value returns NULL, unless its value is set to + something else in the current session with a LET command. + The content of a session variable is not transactional. This is the same as + regular variables in procedural languages. + + + + Session variables are retrieved by the SELECT + command. Their value is set with the LET command. + + + + + Session variables can be shadowed by other identifiers. + For details, see . + + + + + + Parameters + + + + + IF NOT EXISTS + + + Do not throw an error if the name already exists. A notice is issued in + this case. + + + + + + name + + + The name, optionally schema-qualified, of the session variable. + + + + + + data_type + + + The name, optionally schema-qualified, of the data type of the session + variable. + + + + + + COLLATE collation + + + The COLLATE clause assigns a collation to the session + variable (which must be of a collatable data type). If not specified, + the data type's default collation is used. + + + + + + + + + Notes + + + Use the DROP VARIABLE command to remove a session + variable. + + + + + Examples + + + Create an date session variable var1: + +CREATE VARIABLE var1 AS date; + + + + + + + Compatibility + + + The CREATE VARIABLE command is a + PostgreSQL extension. + + + + + See Also + + + + + + + + diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml new file mode 100644 index 000000000000..5bdb3560f0b0 --- /dev/null +++ b/doc/src/sgml/ref/drop_variable.sgml @@ -0,0 +1,117 @@ + + + + + DROP VARIABLE + + + + session variable + removing + + + + DROP VARIABLE + 7 + SQL - Language Statements + + + + DROP VARIABLE + remove a session variable + + + + +DROP VARIABLE [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ] + + + + + Description + + + DROP VARIABLE removes a session variable. + A session variable can only be removed by its owner or a superuser. + + + + + Parameters + + + + IF EXISTS + + + Do not throw an error if the session variable does not exist. A notice is + issued in this case. + + + + + + name + + + The name, optionally schema-qualified, of a session variable. + + + + + + CASCADE + + + Automatically drop objects that depend on the session variable (such as + views), and in turn all objects that depend on those objects + (see ). + + + + + + RESTRICT + + + Refuse to drop the session variable if any objects depend on it. This is + the default. + + + + + + + + Examples + + + To remove the session variable var1: + + +DROP VARIABLE var1; + + + + + Compatibility + + + The DROP VARIABLE command is a + PostgreSQL extension. + + + + + See Also + + + + + + + + diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml index 999f657d5c00..c11860fa200f 100644 --- a/doc/src/sgml/ref/grant.sgml +++ b/doc/src/sgml/ref/grant.sgml @@ -101,6 +101,12 @@ GRANT role_name [, ...] TO role_specification ] +GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] } + ON { VARIABLE variable_name [, ...] + | ALL VARIABLES IN SCHEMA schema_name [, ...] } + TO role_specification [, ...] [ WITH GRANT OPTION ] + [ GRANTED BY role_specification ] + where role_specification can be: [ GROUP ] role_name @@ -119,8 +125,8 @@ GRANT role_name [, ...] TO @@ -236,9 +242,9 @@ GRANT role_name [, ...] TO There is also an option to grant privileges on all objects of the same type within one or more schemas. This functionality is currently supported - only for tables, sequences, functions, and procedures. ALL - TABLES also affects views and foreign tables, just like the - specific-object GRANT command. ALL + only for tables, sequences, functions, procedures and variables. + ALL TABLES also affects views and foreign tables, just + like the specific-object GRANT command. ALL FUNCTIONS also affects aggregate and window functions, but not procedures, again just like the specific-object GRANT command. Use ALL ROUTINES to include procedures. @@ -518,8 +524,8 @@ GRANT admins TO joe; - Privileges on databases, tablespaces, schemas, languages, and - configuration parameters are + Privileges on databases, tablespaces, schemas, languages, session variables + and configuration parameters are PostgreSQL extensions. diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index f7c8bc16a7fc..4989cdc7ddba 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -2135,6 +2135,19 @@ SELECT $1 \parse stmt1 + + \dV[+] [ pattern ] + + + Lists session variables. + If pattern is + specified, only session variables whose names match the pattern are listed. + If the form \dV+ is used, additional information + about each variable is shown, like access privileges and description. + + + + \du[Sx+] [ pattern ] diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml index 8df492281a1c..760fddb7c209 100644 --- a/doc/src/sgml/ref/revoke.sgml +++ b/doc/src/sgml/ref/revoke.sgml @@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ] [ GRANTED BY role_specification ] [ CASCADE | RESTRICT ] +REVOKE [ GRANT OPTION FOR ] + { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] } + ON { VARIABLE variable_name [, ...] + | ALL VARIABLES IN SCHEMA schema_name [, ...] } + FROM { role_specification | PUBLIC } [, ...] + [ GRANTED BY role_specification ] + [ CASCADE | RESTRICT ] + where role_specification can be: [ GROUP ] role_name diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml index ff85ace83fc4..25578f3946cd 100644 --- a/doc/src/sgml/reference.sgml +++ b/doc/src/sgml/reference.sgml @@ -75,6 +75,7 @@ &alterType; &alterUser; &alterUserMapping; + &alterVariable; &alterView; &analyze; &begin; @@ -127,6 +128,7 @@ &createType; &createUser; &createUserMapping; + &createVariable; &createView; &deallocate; &declare; @@ -175,6 +177,7 @@ &dropType; &dropUser; &dropUserMapping; + &dropVariable; &dropView; &end; &execute; diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile index c090094ed08d..2c20d60db19c 100644 --- a/src/backend/catalog/Makefile +++ b/src/backend/catalog/Makefile @@ -45,6 +45,7 @@ OBJS = \ pg_shdepend.o \ pg_subscription.o \ pg_type.o \ + pg_variable.o \ storage.o \ toasting.o diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c index 9ca8a88dc910..587be8c70c8e 100644 --- a/src/backend/catalog/aclchk.c +++ b/src/backend/catalog/aclchk.c @@ -64,6 +64,7 @@ #include "catalog/pg_proc.h" #include "catalog/pg_tablespace.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/dbcommands.h" #include "commands/defrem.h" #include "commands/event_trigger.h" @@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs, case OBJECT_PARAMETER_ACL: whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL; break; + case OBJECT_VARIABLE: + whole_mask = ACL_ALL_RIGHTS_VARIABLE; + break; default: elog(ERROR, "unrecognized object type: %d", objtype); /* not reached, but keep compiler quiet */ @@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt) all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL; errormsg = gettext_noop("invalid privilege type %s for parameter"); break; + case OBJECT_VARIABLE: + all_privileges = ACL_ALL_RIGHTS_VARIABLE; + errormsg = gettext_noop("invalid privilege type %s for session variable"); + break; default: elog(ERROR, "unrecognized GrantStmt.objtype: %d", (int) stmt->objtype); @@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt) case OBJECT_PARAMETER_ACL: ExecGrant_Parameter(istmt); break; + case OBJECT_VARIABLE: + ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL); + break; default: elog(ERROR, "unrecognized GrantStmt.objtype: %d", (int) istmt->objtype); @@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant) objects = lappend_oid(objects, parameterId); } break; + + case OBJECT_VARIABLE: + foreach_node(RangeVar, varvar, objnames) + { + Oid relOid; + + relOid = LookupVariable(varvar->schemaname, + varvar->relname, + false); + objects = lappend_oid(objects, relOid); + } + break; } return objects; @@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames) table_close(rel, AccessShareLock); } break; + case OBJECT_VARIABLE: + { + ScanKeyData key; + Relation rel; + TableScanDesc scan; + HeapTuple tuple; + + ScanKeyInit(&key, + Anum_pg_variable_varnamespace, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(namespaceId)); + + rel = table_open(VariableRelationId, AccessShareLock); + scan = table_beginscan_catalog(rel, 1, &key); + + while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) + { + Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid; + + objects = lappend_oid(objects, oid); + } + + table_endscan(scan); + table_close(rel, AccessShareLock); + } + break; default: /* should not happen */ elog(ERROR, "unrecognized GrantStmt.objtype: %d", @@ -1009,6 +1058,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s all_privileges = ACL_ALL_RIGHTS_LARGEOBJECT; errormsg = gettext_noop("invalid privilege type %s for large object"); break; + case OBJECT_VARIABLE: + all_privileges = ACL_ALL_RIGHTS_VARIABLE; + errormsg = gettext_noop("invalid privilege type %s for session variable"); + break; default: elog(ERROR, "unrecognized GrantStmt.objtype: %d", (int) action->objtype); @@ -1209,6 +1262,11 @@ SetDefaultACL(InternalDefaultACL *iacls) if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS) this_privileges = ACL_ALL_RIGHTS_LARGEOBJECT; break; + case OBJECT_VARIABLE: + objtype = DEFACLOBJ_VARIABLE; + if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS) + this_privileges = ACL_ALL_RIGHTS_VARIABLE; + break; default: elog(ERROR, "unrecognized object type: %d", @@ -1456,6 +1514,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid) case DEFACLOBJ_LARGEOBJECT: iacls.objtype = OBJECT_LARGEOBJECT; break; + case DEFACLOBJ_VARIABLE: + iacls.objtype = OBJECT_VARIABLE; + break; default: /* Shouldn't get here */ elog(ERROR, "unexpected default ACL type: %d", @@ -1516,6 +1577,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid) case ParameterAclRelationId: istmt.objtype = OBJECT_PARAMETER_ACL; break; + case VariableRelationId: + istmt.objtype = OBJECT_VARIABLE; + break; default: elog(ERROR, "unexpected object class %u", classid); break; @@ -2749,6 +2813,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype, case OBJECT_TYPE: msg = gettext_noop("permission denied for type %s"); break; + case OBJECT_VARIABLE: + msg = gettext_noop("permission denied for session variable %s"); + break; case OBJECT_VIEW: msg = gettext_noop("permission denied for view %s"); break; @@ -2860,6 +2927,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype, case OBJECT_TYPE: msg = gettext_noop("must be owner of type %s"); break; + case OBJECT_VARIABLE: + msg = gettext_noop("must be owner of session variable %s"); + break; case OBJECT_VIEW: msg = gettext_noop("must be owner of view %s"); break; @@ -3008,6 +3078,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid, return ACL_NO_RIGHTS; case OBJECT_TYPE: return object_aclmask(TypeRelationId, object_oid, roleid, mask, how); + case OBJECT_VARIABLE: + return object_aclmask(VariableRelationId, object_oid, roleid, mask, how); default: elog(ERROR, "unrecognized object type: %d", (int) objtype); @@ -4271,6 +4343,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid) defaclobjtype = DEFACLOBJ_LARGEOBJECT; break; + case OBJECT_VARIABLE: + defaclobjtype = DEFACLOBJ_VARIABLE; + break; + default: return NULL; } diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c index 18316a3968bc..9e0f648b74fd 100644 --- a/src/backend/catalog/dependency.c +++ b/src/backend/catalog/dependency.c @@ -65,12 +65,14 @@ #include "catalog/pg_ts_template.h" #include "catalog/pg_type.h" #include "catalog/pg_user_mapping.h" +#include "catalog/pg_variable.h" #include "commands/comment.h" #include "commands/defrem.h" #include "commands/event_trigger.h" #include "commands/extension.h" #include "commands/policy.h" #include "commands/publicationcmds.h" +#include "commands/schemacmds.h" #include "commands/seclabel.h" #include "commands/sequence.h" #include "commands/trigger.h" @@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags) RemovePublicationById(object->objectId); break; + case VariableRelationId: + DropVariableById(object->objectId); + break; + case CastRelationId: case CollationRelationId: case ConversionRelationId: diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build index 1958ea9238a7..ed44c877fca4 100644 --- a/src/backend/catalog/meson.build +++ b/src/backend/catalog/meson.build @@ -32,6 +32,7 @@ backend_sources += files( 'pg_shdepend.c', 'pg_subscription.c', 'pg_type.c', + 'pg_variable.c', 'storage.c', 'toasting.c', ) diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c index d97d632a7ef5..4307cad15c79 100644 --- a/src/backend/catalog/namespace.c +++ b/src/backend/catalog/namespace.c @@ -41,6 +41,7 @@ #include "catalog/pg_ts_parser.h" #include "catalog/pg_ts_template.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/dbcommands.h" #include "common/hashfn_unstable.h" #include "funcapi.h" @@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing); static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing); static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing); static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing); +static bool VariableIsVisibleExt(Oid varid, bool *is_missing); static void recomputeNamespacePath(void); static void AccessTempTableNamespace(bool force); static void InitTempTableNamespace(void); @@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing) return visible; } +/* + * VariableIsVisible + * Determine whether a variable (identified by OID) is visible in the + * current search path. Visible means "would be found by searching + * for the unqualified variable name". + */ +bool +VariableIsVisible(Oid varid) +{ + return VariableIsVisibleExt(varid, NULL); +} + +/* + * VariableIsVisibleExt + * As above, but if the variable isn't found and is_missing is not NULL, + * then set *is_missing = true and return false, instead of throwing + * an error. (Caller must initialize *is_missing = false.) + */ +static bool +VariableIsVisibleExt(Oid varid, bool *is_missing) +{ + HeapTuple vartup; + Form_pg_variable varform; + Oid varnamespace; + bool visible; + + vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + if (!HeapTupleIsValid(vartup)) + { + if (is_missing != NULL) + { + *is_missing = true; + return false; + } + + elog(ERROR, "cache lookup failed for session variable %u", varid); + } + varform = (Form_pg_variable) GETSTRUCT(vartup); + + recomputeNamespacePath(); + + /* + * Quick check: if it ain't in the path at all, it ain't visible. We + * don't expect usage of session variables in the system namespace. + */ + varnamespace = varform->varnamespace; + if (!list_member_oid(activeSearchPath, varnamespace)) + visible = false; + else + { + /* + * If it is in the path, it might still not be visible; it could be + * hidden by another variable of the same name earlier in the path. So + * we must do a slow check for conflicting relations. + */ + char *varname = NameStr(varform->varname); + + visible = false; + foreach_oid(namespaceId, activeSearchPath) + { + if (namespaceId == varnamespace) + { + /* found it first in path */ + visible = true; + break; + } + if (OidIsValid(get_varname_varid(varname, namespaceId))) + { + /* found something else first in path */ + break; + } + } + } + + ReleaseSysCache(vartup); + + return visible; +} /* * TypenameGetTypid @@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing) return visible; } +/* + * Returns oid of session variable specified by possibly qualified identifier. + * + * If not found, returns InvalidOid if missing_ok, else throws error. + */ +Oid +LookupVariable(const char *nspname, + const char *varname, + bool missing_ok) +{ + Oid varoid = InvalidOid; + + if (nspname) + { + Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok); + + /* if nspname is a known namespace, the variable must be there */ + if (OidIsValid(namespaceId)) + { + varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid, + PointerGetDatum(varname), + ObjectIdGetDatum(namespaceId)); + } + } + else + { + /* iterate over the schemas on the search_path */ + recomputeNamespacePath(); + + foreach_oid(namespaceId, activeSearchPath) + { + varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid, + PointerGetDatum(varname), + ObjectIdGetDatum(namespaceId)); + + if (OidIsValid(varoid)) + break; + } + } + + if (!OidIsValid(varoid) && !missing_ok) + { + if (nspname) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("session variable \"%s.%s\" does not exist", + nspname, varname))); + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("session variable \"%s\" does not exist", + varname))); + } + + return varoid; +} + +/* + * Returns oid of session variable specified by possibly qualified identifier + * + * If not found, returns InvalidOid if missing_ok, else throws error. + */ +Oid +LookupVariableFromNameList(List *names, + bool missing_ok) +{ + char *catname = NULL; + char *nspname = NULL; + char *varname = NULL; + + switch (list_length(names)) + { + case 1: + varname = strVal(linitial(names)); + break; + case 2: + nspname = strVal(linitial(names)); + varname = strVal(lsecond(names)); + break; + case 3: + catname = strVal(linitial(names)); + nspname = strVal(lsecond(names)); + varname = strVal(lthird(names)); + + /* check catalog name */ + if (strcmp(catname, get_database_name(MyDatabaseId)) != 0) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: %s", + NameListToString(names)))); + break; + default: + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("improper session variable name (too many dotted names): %s", + NameListToString(names)))); + break; + } + + return LookupVariable(nspname, varname, missing_ok); +} + +/* + * The input list contains names with indirection expressions used as the left + * part of LET statement. The following routine returns a new list with only + * initial strings (names) - without indirection expressions. + */ +List * +NamesFromList(List *names) +{ + ListCell *l; + List *result = NIL; + + foreach(l, names) + { + Node *n = lfirst(l); + + if (IsA(n, String)) + { + result = lappend(result, n); + } + else + break; + } + + return result; +} /* * DeconstructQualifiedName @@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS) PG_RETURN_BOOL(isOtherTempNamespace(oid)); } + +Datum +pg_variable_is_visible(PG_FUNCTION_ARGS) +{ + Oid oid = PG_GETARG_OID(0); + bool result; + bool is_missing = false; + + result = VariableIsVisibleExt(oid, &is_missing); + + if (is_missing) + PG_RETURN_NULL(); + PG_RETURN_BOOL(result); +} diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c index b63fd57dc04b..444892ad6baf 100644 --- a/src/backend/catalog/objectaddress.c +++ b/src/backend/catalog/objectaddress.c @@ -62,6 +62,7 @@ #include "catalog/pg_ts_template.h" #include "catalog/pg_type.h" #include "catalog/pg_user_mapping.h" +#include "catalog/pg_variable.h" #include "commands/dbcommands.h" #include "commands/defrem.h" #include "commands/event_trigger.h" @@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] = OBJECT_USER_MAPPING, false }, + { + "session variable", + VariableRelationId, + VariableOidIndexId, + VARIABLEOID, + VARIABLENAMENSP, + Anum_pg_variable_oid, + Anum_pg_variable_varname, + Anum_pg_variable_varnamespace, + Anum_pg_variable_varowner, + Anum_pg_variable_varacl, + OBJECT_VARIABLE, + true + } }; /* @@ -831,6 +846,9 @@ static const struct object_type_map }, { "statistics object", OBJECT_STATISTIC_EXT + }, + { + "session variable", OBJECT_VARIABLE } }; @@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype, bool missing_ok); static ObjectAddress get_object_address_type(ObjectType objtype, TypeName *typename, bool missing_ok); +static ObjectAddress get_object_address_variable(List *object, bool missing_ok); static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object, bool missing_ok); static ObjectAddress get_object_address_opf_member(ObjectType objtype, @@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object, missing_ok); address.objectSubId = 0; break; + case OBJECT_VARIABLE: + address = get_object_address_variable(castNode(List, object), missing_ok); + break; /* no default, to let compiler warn about missing case */ } @@ -2008,17 +2030,21 @@ get_object_address_defacl(List *object, bool missing_ok) case DEFACLOBJ_LARGEOBJECT: objtype_str = "large objects"; break; + case DEFACLOBJ_VARIABLE: + objtype_str = "variables"; + break; default: ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("unrecognized default ACL object type \"%c\"", objtype), - errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".", + errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".", DEFACLOBJ_RELATION, DEFACLOBJ_SEQUENCE, DEFACLOBJ_FUNCTION, DEFACLOBJ_TYPE, DEFACLOBJ_NAMESPACE, - DEFACLOBJ_LARGEOBJECT))); + DEFACLOBJ_LARGEOBJECT, + DEFACLOBJ_VARIABLE))); } /* @@ -2102,6 +2128,24 @@ textarray_to_strvaluelist(ArrayType *arr) return list; } +/* + * Find the ObjectAddress for a session variable + */ +static ObjectAddress +get_object_address_variable(List *object, bool missing_ok) +{ + ObjectAddress address; + char *nspname = NULL; + char *varname = NULL; + + ObjectAddressSet(address, VariableRelationId, InvalidOid); + + DeconstructQualifiedName(object, &nspname, &varname); + address.objectId = LookupVariable(nspname, varname, missing_ok); + + return address; +} + /* * SQL-callable version of get_object_address */ @@ -2296,6 +2340,7 @@ pg_get_object_address(PG_FUNCTION_ARGS) case OBJECT_TABCONSTRAINT: case OBJECT_OPCLASS: case OBJECT_OPFAMILY: + case OBJECT_VARIABLE: objnode = (Node *) name; break; case OBJECT_ACCESS_METHOD: @@ -2467,6 +2512,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address, case OBJECT_STATISTIC_EXT: case OBJECT_TSDICTIONARY: case OBJECT_TSCONFIGURATION: + case OBJECT_VARIABLE: if (!object_ownercheck(address.classId, address.objectId, roleid)) aclcheck_error(ACLCHECK_NOT_OWNER, objtype, NameListToString(castNode(List, object))); @@ -3496,6 +3542,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok) break; } + case VariableRelationId: + { + char *nspname; + HeapTuple tup; + Form_pg_variable varform; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId)); + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", + object->objectId); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + if (VariableIsVisible(object->objectId)) + nspname = NULL; + else + nspname = get_namespace_name(varform->varnamespace); + + appendStringInfo(&buffer, _("session variable %s"), + quote_qualified_identifier(nspname, + NameStr(varform->varname))); + + ReleaseSysCache(tup); + break; + } + case TSParserRelationId: { HeapTuple tup; @@ -3854,6 +3926,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok) _("default privileges on new large objects belonging to role %s"), rolename); break; + case DEFACLOBJ_VARIABLE: + if (nspname) + appendStringInfo(&buffer, + _("default privileges on new session variables belonging to role %s in schema %s"), + rolename, nspname); + else + appendStringInfo(&buffer, + _("default privileges on new session variables belonging to role %s"), + rolename); + break; default: /* shouldn't get here */ if (nspname) @@ -4670,6 +4752,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok) appendStringInfoString(&buffer, "transform"); break; + case VariableRelationId: + appendStringInfoString(&buffer, "session variable"); + break; + default: elog(ERROR, "unsupported object class: %u", object->classId); } @@ -5780,6 +5866,10 @@ getObjectIdentityParts(const ObjectAddress *object, appendStringInfoString(&buffer, " on large objects"); break; + case DEFACLOBJ_VARIABLE: + appendStringInfoString(&buffer, + " on session variables"); + break; } if (objname) @@ -6020,6 +6110,33 @@ getObjectIdentityParts(const ObjectAddress *object, } break; + case VariableRelationId: + { + char *schema; + char *varname; + HeapTuple tup; + Form_pg_variable varform; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId)); + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", + object->objectId); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + schema = get_namespace_name_or_temp(varform->varnamespace); + varname = NameStr(varform->varname); + + appendStringInfo(&buffer, "%s", + quote_qualified_identifier(schema, varname)); + + if (objname) + *objname = list_make2(schema, pstrdup(varname)); + + ReleaseSysCache(tup); + break; + } + default: elog(ERROR, "unsupported object class: %u", object->classId); } diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c index 536191284e80..c6fd1fa074f5 100644 --- a/src/backend/catalog/pg_shdepend.c +++ b/src/backend/catalog/pg_shdepend.c @@ -46,6 +46,7 @@ #include "catalog/pg_ts_dict.h" #include "catalog/pg_type.h" #include "catalog/pg_user_mapping.h" +#include "catalog/pg_variable.h" #include "commands/alter.h" #include "commands/dbcommands.h" #include "commands/defrem.h" @@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole) case DatabaseRelationId: case TSConfigRelationId: case TSDictionaryRelationId: + case VariableRelationId: AlterObjectOwner_internal(sdepForm->classid, sdepForm->objid, newrole); diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c new file mode 100644 index 000000000000..29d967a2d5bf --- /dev/null +++ b/src/backend/catalog/pg_variable.c @@ -0,0 +1,251 @@ +/*------------------------------------------------------------------------- + * + * pg_variable.c + * session variables + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/backend/catalog/pg_variable.c + * + *------------------------------------------------------------------------- + */ + +#include "postgres.h" + +#include "access/heapam.h" +#include "catalog/dependency.h" +#include "catalog/indexing.h" +#include "catalog/namespace.h" +#include "catalog/objectaccess.h" +#include "catalog/pg_collation.h" +#include "catalog/pg_namespace.h" +#include "catalog/pg_variable.h" +#include "miscadmin.h" +#include "parser/parse_type.h" +#include "utils/builtins.h" +#include "utils/lsyscache.h" +#include "utils/syscache.h" + +static ObjectAddress create_variable(const char *varName, + Oid varNamespace, + Oid varType, + int32 varTypmod, + Oid varOwner, + Oid varCollation, + bool if_not_exists); + + +/* + * Creates entry in pg_variable table + */ +static ObjectAddress +create_variable(const char *varName, + Oid varNamespace, + Oid varType, + int32 varTypmod, + Oid varOwner, + Oid varCollation, + bool if_not_exists) +{ + Acl *varacl; + NameData varname; + bool nulls[Natts_pg_variable]; + Datum values[Natts_pg_variable]; + Relation rel; + HeapTuple tup; + TupleDesc tupdesc; + ObjectAddress myself, + referenced; + ObjectAddresses *addrs; + Oid varid; + + Assert(varName); + Assert(OidIsValid(varNamespace)); + Assert(OidIsValid(varType)); + Assert(OidIsValid(varOwner)); + + rel = table_open(VariableRelationId, RowExclusiveLock); + + /* + * Check for duplicates. Note that this does not really prevent + * duplicates, it's here just to provide nicer error message in common + * case. The real protection is the unique key on the catalog. + */ + if (SearchSysCacheExists2(VARIABLENAMENSP, + PointerGetDatum(varName), + ObjectIdGetDatum(varNamespace))) + { + if (if_not_exists) + ereport(NOTICE, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("session variable \"%s\" already exists, skipping", + varName))); + else + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("session variable \"%s\" already exists", + varName))); + + table_close(rel, RowExclusiveLock); + + return InvalidObjectAddress; + } + + memset(values, 0, sizeof(values)); + memset(nulls, false, sizeof(nulls)); + + namestrcpy(&varname, varName); + + varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid); + + values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid); + values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname); + values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace); + values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType); + values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod); + values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner); + values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation); + + varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner, + varNamespace); + if (varacl != NULL) + values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl); + else + nulls[Anum_pg_variable_varacl - 1] = true; + + tupdesc = RelationGetDescr(rel); + + tup = heap_form_tuple(tupdesc, values, nulls); + CatalogTupleInsert(rel, tup); + Assert(OidIsValid(varid)); + + addrs = new_object_addresses(); + + ObjectAddressSet(myself, VariableRelationId, varid); + + /* dependency on namespace */ + ObjectAddressSet(referenced, NamespaceRelationId, varNamespace); + add_exact_object_address(&referenced, addrs); + + /* dependency on used type */ + ObjectAddressSet(referenced, TypeRelationId, varType); + add_exact_object_address(&referenced, addrs); + + /* dependency on collation */ + if (OidIsValid(varCollation) && + varCollation != DEFAULT_COLLATION_OID) + { + ObjectAddressSet(referenced, CollationRelationId, varCollation); + add_exact_object_address(&referenced, addrs); + } + + record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL); + free_object_addresses(addrs); + + /* dependency on owner */ + recordDependencyOnOwner(VariableRelationId, varid, varOwner); + + /* dependencies on roles mentioned in default ACL */ + recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl); + + /* dependency on extension */ + recordDependencyOnCurrentExtension(&myself, false); + + heap_freetuple(tup); + + /* post creation hook for new function */ + InvokeObjectPostCreateHook(VariableRelationId, varid, 0); + + table_close(rel, RowExclusiveLock); + + return myself; +} + +/* + * Creates a new variable + * + * Used by CREATE VARIABLE command + */ +ObjectAddress +CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt) +{ + Oid namespaceid; + AclResult aclresult; + Oid typid; + int32 typmod; + Oid varowner = GetUserId(); + Oid collation; + Oid typcollation; + ObjectAddress variable; + + namespaceid = + RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL); + + typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod); + + /* disallow pseudotypes */ + if (get_typtype(typid) == TYPTYPE_PSEUDO) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("session variable cannot be pseudo-type %s", + format_type_be(typid)))); + + aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE); + if (aclresult != ACLCHECK_OK) + aclcheck_error_type(aclresult, typid); + + typcollation = get_typcollation(typid); + + if (stmt->collClause) + collation = LookupCollation(pstate, + stmt->collClause->collname, + stmt->collClause->location); + else + collation = typcollation; + + /* complain if COLLATE is applied to an uncollatable type */ + if (OidIsValid(collation) && !OidIsValid(typcollation)) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("collations are not supported by type %s", + format_type_be(typid)), + parser_errposition(pstate, stmt->collClause->location))); + + variable = create_variable(stmt->variable->relname, + namespaceid, + typid, + typmod, + varowner, + collation, + stmt->if_not_exists); + + elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable", + stmt->variable->relname, variable.objectId); + + return variable; +} + +/* + * Drop variable by OID + */ +void +DropVariableById(Oid varid) +{ + Relation rel; + HeapTuple tup; + + rel = table_open(VariableRelationId, RowExclusiveLock); + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for variable %u", varid); + + CatalogTupleDelete(rel, &tup->t_self); + + ReleaseSysCache(tup); + + table_close(rel, RowExclusiveLock); +} diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c index c801c869c1cf..c72a4adb07be 100644 --- a/src/backend/commands/alter.c +++ b/src/backend/commands/alter.c @@ -41,6 +41,7 @@ #include "catalog/pg_ts_dict.h" #include "catalog/pg_ts_parser.h" #include "catalog/pg_ts_template.h" +#include "catalog/pg_variable.h" #include "commands/alter.h" #include "commands/collationcmds.h" #include "commands/dbcommands.h" @@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid) Assert(OidIsValid(nspOid)); msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\""); break; + case VariableRelationId: + Assert(OidIsValid(nspOid)); + msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\""); + break; default: elog(ERROR, "unsupported object class: %u", classId); break; @@ -435,6 +440,7 @@ ExecRenameStmt(RenameStmt *stmt) case OBJECT_TSTEMPLATE: case OBJECT_PUBLICATION: case OBJECT_SUBSCRIPTION: + case OBJECT_VARIABLE: { ObjectAddress address; Relation catalog; @@ -575,6 +581,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt, case OBJECT_TSDICTIONARY: case OBJECT_TSPARSER: case OBJECT_TSTEMPLATE: + case OBJECT_VARIABLE: { Relation catalog; Oid classId; @@ -657,6 +664,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid, case TSDictionaryRelationId: case TSTemplateRelationId: case TSConfigRelationId: + case VariableRelationId: { Relation catalog; @@ -887,6 +895,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt) case OBJECT_TABLESPACE: case OBJECT_TSDICTIONARY: case OBJECT_TSCONFIGURATION: + case OBJECT_VARIABLE: { ObjectAddress address; diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c index ceb9a229b63b..ebb585dc4a1e 100644 --- a/src/backend/commands/dropcmds.c +++ b/src/backend/commands/dropcmds.c @@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object) msg = gettext_noop("publication \"%s\" does not exist, skipping"); name = strVal(object); break; + case OBJECT_VARIABLE: + msg = gettext_noop("session variable \"%s\" does not exist, skipping"); + name = NameListToString(castNode(List, object)); + break; case OBJECT_COLUMN: case OBJECT_DATABASE: diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c index edc2c988e293..1839c1f82c53 100644 --- a/src/backend/commands/event_trigger.c +++ b/src/backend/commands/event_trigger.c @@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype) return "TABLESPACE"; case OBJECT_TYPE: return "TYPE"; + case OBJECT_VARIABLE: + return "VARIABLE"; /* these currently aren't used */ case OBJECT_ACCESS_METHOD: case OBJECT_AGGREGATE: @@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype) return "TABLESPACES"; case OBJECT_TYPE: return "TYPES"; + case OBJECT_VARIABLE: + return "VARIABLES"; /* these currently aren't used */ case OBJECT_ACCESS_METHOD: case OBJECT_AGGREGATE: diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c index cee5d7bbb9c7..57b4e6719c25 100644 --- a/src/backend/commands/seclabel.c +++ b/src/backend/commands/seclabel.c @@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype) case OBJECT_TSPARSER: case OBJECT_TSTEMPLATE: case OBJECT_USER_MAPPING: + case OBJECT_VARIABLE: return false; /* diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 2705cf11330d..491549335c95 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -52,6 +52,7 @@ #include "catalog/pg_tablespace.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "catalog/storage.h" #include "catalog/storage_xlog.h" #include "catalog/toasting.h" @@ -6910,6 +6911,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, * (possibly nested several levels deep in composite types, arrays, etc!). * Eventually, we'd like to propagate the check or rewrite operation * into such tables, but for now, just error out if we find any. + * Also, check if "typeOid" is used as type of some session variable. * * Caller should provide either the associated relation of a rowtype, * or a type name (not both) for use in the error message, if any. @@ -6973,6 +6975,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation, continue; } + /* check if the type is used as type of some session variable */ + if (pg_depend->classid == VariableRelationId) + { + Oid varid = pg_depend->objid; + + if (origTypeName) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it", + origTypeName, + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid)))); + else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it", + RelationGetRelationName(origRelation), + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid)))); + else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it", + RelationGetRelationName(origRelation), + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid)))); + else if (origRelation->rd_rel->relkind == RELKIND_RELATION || + origRelation->rd_rel->relkind == RELKIND_MATVIEW || + origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it", + RelationGetRelationName(origRelation), + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid)))); + + continue; + } + /* Else, ignore dependees that aren't relations */ if (pg_depend->classid != RelationRelationId) continue; diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c index 45ae7472ab5a..f8fefdc2cf87 100644 --- a/src/backend/commands/typecmds.c +++ b/src/backend/commands/typecmds.c @@ -53,6 +53,7 @@ #include "catalog/pg_proc.h" #include "catalog/pg_range.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/defrem.h" #include "commands/tablecmds.h" #include "commands/typecmds.h" @@ -3373,6 +3374,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode) } continue; } + else if (pg_depend->classid == VariableRelationId) + { + /* + * We cannot to validate constraint inside session variables + * from other sessions, so better to fail if there are any + * session variable, that use this domain. + */ + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it", + domainTypeName, + get_namespace_name(get_session_variable_namespace(pg_depend->objid)), + get_session_variable_name(pg_depend->objid)))); + } /* Else, ignore dependees that aren't user columns of relations */ /* (we assume system columns are never of domain types) */ diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 3c4268b271a4..71c71272958d 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -52,6 +52,7 @@ #include "catalog/namespace.h" #include "catalog/pg_am.h" #include "catalog/pg_trigger.h" +#include "catalog/pg_variable.h" #include "commands/defrem.h" #include "commands/trigger.h" #include "gramparse.h" @@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt - CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt - CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt + CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt + CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt @@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN UNLISTEN UNLOGGED UNTIL UPDATE USER USING - VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING - VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE + VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE + VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE @@ -1050,6 +1051,7 @@ stmt: | CreatePolicyStmt | CreatePLangStmt | CreateSchemaStmt + | CreateSessionVarStmt | CreateSeqStmt | CreateStmt | CreateSubscriptionStmt @@ -1592,6 +1594,7 @@ schema_stmt: | CreateTrigStmt | GrantStmt | ViewStmt + | CreateSessionVarStmt ; @@ -5267,6 +5270,34 @@ create_extension_opt_item: } ; +/***************************************************************************** + * + * QUERY : + * CREATE VARIABLE varname [AS] type + * + *****************************************************************************/ + +CreateSessionVarStmt: + CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause + { + CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt); + n->variable = $3; + n->typeName = $5; + n->collClause = (CollateClause *) $6; + n->if_not_exists = false; + $$ = (Node *) n; + } + | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause + { + CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt); + n->variable = $6; + n->typeName = $8; + n->collClause = (CollateClause *) $9; + n->if_not_exists = true; + $$ = (Node *) n; + } + ; + /***************************************************************************** * * ALTER EXTENSION name UPDATE [ TO version ] @@ -7058,6 +7089,7 @@ object_type_any_name: | TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; } | TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; } | TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; } + | VARIABLE { $$ = OBJECT_VARIABLE; } ; /* @@ -7934,6 +7966,14 @@ privilege_target: n->objs = $2; $$ = n; } + | VARIABLE qualified_name_list + { + PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget)); + n->targtype = ACL_TARGET_OBJECT; + n->objtype = OBJECT_VARIABLE; + n->objs = $2; + $$ = n; + } | ALL TABLES IN_P SCHEMA name_list { PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget)); @@ -7979,6 +8019,14 @@ privilege_target: n->objs = $5; $$ = n; } + | ALL VARIABLES IN_P SCHEMA name_list + { + PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget)); + n->targtype = ACL_TARGET_ALL_IN_SCHEMA; + n->objtype = OBJECT_VARIABLE; + n->objs = $5; + $$ = n; + } ; @@ -8177,6 +8225,7 @@ defacl_privilege_target: | TYPES_P { $$ = OBJECT_TYPE; } | SCHEMAS { $$ = OBJECT_SCHEMA; } | LARGE_P OBJECTS_P { $$ = OBJECT_LARGEOBJECT; } + | VARIABLES { $$ = OBJECT_VARIABLE; } ; @@ -9965,6 +10014,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name n->missing_ok = false; $$ = (Node *) n; } + | ALTER VARIABLE any_name RENAME TO name + { + RenameStmt *n = makeNode(RenameStmt); + n->renameType = OBJECT_VARIABLE; + n->object = (Node *) $3; + n->newname = $6; + n->missing_ok = false; + $$ = (Node *)n; + } + | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name + { + RenameStmt *n = makeNode(RenameStmt); + n->renameType = OBJECT_VARIABLE; + n->object = (Node *) $5; + n->newname = $8; + n->missing_ok = true; + $$ = (Node *)n; + } ; opt_column: COLUMN @@ -10326,6 +10393,24 @@ AlterObjectSchemaStmt: n->missing_ok = false; $$ = (Node *) n; } + | ALTER VARIABLE any_name SET SCHEMA name + { + AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt); + n->objectType = OBJECT_VARIABLE; + n->object = (Node *) $3; + n->newschema = $6; + n->missing_ok = false; + $$ = (Node *)n; + } + | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name + { + AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt); + n->objectType = OBJECT_VARIABLE; + n->object = (Node *) $5; + n->newschema = $8; + n->missing_ok = true; + $$ = (Node *)n; + } ; /***************************************************************************** @@ -10607,6 +10692,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec n->newowner = $6; $$ = (Node *) n; } + | ALTER VARIABLE any_name OWNER TO RoleSpec + { + AlterOwnerStmt *n = makeNode(AlterOwnerStmt); + n->objectType = OBJECT_VARIABLE; + n->object = (Node *) $3; + n->newowner = $6; + $$ = (Node *)n; + } ; @@ -18017,6 +18110,8 @@ unreserved_keyword: | VALIDATE | VALIDATOR | VALUE_P + | VARIABLE + | VARIABLES | VARYING | VERSION_P | VIEW @@ -18673,6 +18768,8 @@ bare_label_keyword: | VALUE_P | VALUES | VARCHAR + | VARIABLE + | VARIABLES | VARIADIC | VERBOSE | VERSION_P diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c index 62015431fdf1..b6cbe354c51e 100644 --- a/src/backend/parser/parse_utilcmd.c +++ b/src/backend/parser/parse_utilcmd.c @@ -105,6 +105,7 @@ typedef struct List *indexes; /* CREATE INDEX items */ List *triggers; /* CREATE TRIGGER items */ List *grants; /* GRANT items */ + List *variables; /* CREATE VARIABLE items */ } CreateSchemaStmtContext; @@ -4091,6 +4092,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName) cxt.indexes = NIL; cxt.triggers = NIL; cxt.grants = NIL; + cxt.variables = NIL; /* * Run through each schema element in the schema element list. Separate @@ -4159,6 +4161,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName) cxt.grants = lappend(cxt.grants, element); break; + case T_CreateSessionVarStmt: + { + CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element; + + setSchemaName(cxt.schemaname, &elp->variable->schemaname); + cxt.variables = lappend(cxt.variables, element); + } + break; + default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(element)); @@ -4172,6 +4183,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName) result = list_concat(result, cxt.indexes); result = list_concat(result, cxt.triggers); result = list_concat(result, cxt.grants); + result = list_concat(result, cxt.variables); return result; } diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 25fe3d580166..99a51877d349 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -23,6 +23,7 @@ #include "catalog/namespace.h" #include "catalog/pg_authid.h" #include "catalog/pg_inherits.h" +#include "catalog/pg_variable.h" #include "catalog/toasting.h" #include "commands/alter.h" #include "commands/async.h" @@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree) case T_CreateRangeStmt: case T_CreateRoleStmt: case T_CreateSchemaStmt: + case T_CreateSessionVarStmt: case T_CreateSeqStmt: case T_CreateStatsStmt: case T_CreateStmt: @@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate, } break; + case T_CreateSessionVarStmt: + address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree); + break; + /* * ************* object creation / destruction ************** */ @@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype) case OBJECT_STATISTIC_EXT: tag = CMDTAG_ALTER_STATISTICS; break; + case OBJECT_VARIABLE: + tag = CMDTAG_ALTER_VARIABLE; + break; default: tag = CMDTAG_UNKNOWN; break; @@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree) case OBJECT_STATISTIC_EXT: tag = CMDTAG_DROP_STATISTICS; break; + case OBJECT_VARIABLE: + tag = CMDTAG_DROP_VARIABLE; + break; default: tag = CMDTAG_UNKNOWN; } @@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree) } break; + case T_CreateSessionVarStmt: + tag = CMDTAG_CREATE_VARIABLE; + break; + default: elog(WARNING, "unrecognized node type: %d", (int) nodeTag(parsetree)); @@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree) } break; + case T_CreateSessionVarStmt: + lev = LOGSTMT_DDL; + break; + default: elog(WARNING, "unrecognized node type: %d", (int) nodeTag(parsetree)); diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c index ca3c5ee3df3a..07874d4ba394 100644 --- a/src/backend/utils/adt/acl.c +++ b/src/backend/utils/adt/acl.c @@ -31,6 +31,7 @@ #include "catalog/pg_proc.h" #include "catalog/pg_tablespace.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/dbcommands.h" #include "commands/proclang.h" #include "commands/tablespace.h" @@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text); static AclMode convert_parameter_priv_string(text *priv_text); static AclMode convert_largeobject_priv_string(text *priv_type_text); static AclMode convert_role_priv_string(text *priv_type_text); +static Oid convert_session_variable_name(text *varname); +static AclMode convert_session_variable_priv_string(text *priv_type_text); static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode); static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue); @@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId) world_default = ACL_NO_RIGHTS; owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL; break; + case OBJECT_VARIABLE: + world_default = ACL_NO_RIGHTS; + owner_default = ACL_ALL_RIGHTS_VARIABLE; + break; default: elog(ERROR, "unrecognized object type: %d", (int) objtype); world_default = ACL_NO_RIGHTS; /* keep compiler quiet */ @@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS) case 'T': objtype = OBJECT_TYPE; break; + case 'V': + objtype = OBJECT_VARIABLE; + break; default: elog(ERROR, "unrecognized object type abbreviation: %c", objtypec); } @@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode) return ACLCHECK_NO_PRIV; } +/* + * has_session_variable_privilege variants + * These are all named "has_session_variable_privilege" at the SQL level. + * They take various combinations of variable name, variable OID, + * user name, user OID, or implicit user = current_user. + * + * The result is a boolean value: true if user has the indicated + * privilege, false if not, or NULL if session variable doesn't + * exists. + */ + +/* + * has_session_variable_privilege_name_name + * Check user privileges on a session variable given + * name username, text session variable name, and text priv name. + */ +Datum +has_session_variable_privilege_name_name(PG_FUNCTION_ARGS) +{ + Name rolename = PG_GETARG_NAME(0); + text *varname = PG_GETARG_TEXT_PP(1); + text *priv_type_text = PG_GETARG_TEXT_PP(2); + Oid roleid; + Oid varid; + AclMode mode; + AclResult aclresult; + bool is_missing = false; + + roleid = get_role_oid_or_public(NameStr(*rolename)); + mode = convert_session_variable_priv_string(priv_type_text); + varid = convert_session_variable_name(varname); + + aclresult = object_aclcheck_ext(VariableRelationId, varid, + roleid, mode, + &is_missing); + + if (is_missing) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(aclresult == ACLCHECK_OK); +} + +/* + * has_session_variable_privilege_name + * Check user privileges on a session variable given + * text session variable and text priv name. + * current_user is assumed + */ +Datum +has_session_variable_privilege_name(PG_FUNCTION_ARGS) +{ + text *varname = PG_GETARG_TEXT_PP(0); + text *priv_type_text = PG_GETARG_TEXT_PP(1); + Oid roleid; + Oid varid; + AclMode mode; + AclResult aclresult; + bool is_missing = false; + + roleid = GetUserId(); + mode = convert_session_variable_priv_string(priv_type_text); + varid = convert_session_variable_name(varname); + + aclresult = object_aclcheck_ext(VariableRelationId, varid, + roleid, mode, + &is_missing); + + PG_RETURN_BOOL(aclresult == ACLCHECK_OK); +} + +/* + * has_session_variable_privilege_name_id + * Check user privileges on a session variable given + * name usename, session variable oid, and text priv name. + */ +Datum +has_session_variable_privilege_name_id(PG_FUNCTION_ARGS) +{ + Name username = PG_GETARG_NAME(0); + Oid varid = PG_GETARG_OID(1); + text *priv_type_text = PG_GETARG_TEXT_PP(2); + Oid roleid; + AclMode mode; + AclResult aclresult; + bool is_missing = false; + + roleid = get_role_oid_or_public(NameStr(*username)); + mode = convert_session_variable_priv_string(priv_type_text); + + aclresult = object_aclcheck_ext(VariableRelationId, varid, + roleid, mode, + &is_missing); + + if (is_missing) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(aclresult == ACLCHECK_OK); +} + +/* + * has_session_variable_privilege_id + * Check user privileges on a session variable given + * session variable oid, and text priv name. + * current_user is assumed + */ +Datum +has_session_variable_privilege_id(PG_FUNCTION_ARGS) +{ + Oid varid = PG_GETARG_OID(0); + text *priv_type_text = PG_GETARG_TEXT_PP(1); + Oid roleid; + AclMode mode; + AclResult aclresult; + bool is_missing = false; + + roleid = GetUserId(); + mode = convert_session_variable_priv_string(priv_type_text); + + aclresult = object_aclcheck_ext(VariableRelationId, varid, + roleid, mode, + &is_missing); + + if (is_missing) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(aclresult == ACLCHECK_OK); +} + +/* + * has_session_variable_privilege_id_name + * Check user privileges on a session variable given + * roleid, text session variable name, and text priv name. + */ +Datum +has_session_variable_privilege_id_name(PG_FUNCTION_ARGS) +{ + Oid roleid = PG_GETARG_OID(0); + text *varname = PG_GETARG_TEXT_PP(1); + text *priv_type_text = PG_GETARG_TEXT_PP(2); + Oid varid; + AclMode mode; + AclResult aclresult; + bool is_missing = false; + + mode = convert_session_variable_priv_string(priv_type_text); + varid = convert_session_variable_name(varname); + + aclresult = object_aclcheck_ext(VariableRelationId, varid, + roleid, mode, + &is_missing); + + if (is_missing) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(aclresult == ACLCHECK_OK); +} + +/* + * has_session_variable_privilege_id_id + * Check user privileges on a session variable given + * roleid, session variable oid, and text priv name. + */ +Datum +has_session_variable_privilege_id_id(PG_FUNCTION_ARGS) +{ + Oid roleid = PG_GETARG_OID(0); + Oid varid = PG_GETARG_OID(1); + text *priv_type_text = PG_GETARG_TEXT_PP(2); + AclMode mode; + AclResult aclresult; + bool is_missing = false; + + mode = convert_session_variable_priv_string(priv_type_text); + + aclresult = object_aclcheck_ext(VariableRelationId, varid, + roleid, mode, + &is_missing); + + if (is_missing) + PG_RETURN_NULL(); + + PG_RETURN_BOOL(aclresult == ACLCHECK_OK); +} + +/* + * Given a session variable name expressed as a string, look it up and return + * Oid + */ +static Oid +convert_session_variable_name(text *varname) +{ + return LookupVariableFromNameList(textToQualifiedNameList(varname), true); +} + +/* + * convert_variable_priv_string + * Convert text string to AclMode value. + */ +static AclMode +convert_session_variable_priv_string(text *priv_type_text) +{ + static const priv_map session_variable_priv_map[] = { + {"SELECT", ACL_SELECT}, + {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)}, + {"UPDATE", ACL_UPDATE}, + {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)}, + {NULL, 0} + }; + + return convert_any_priv_string(priv_type_text, session_variable_priv_map); +} /* * initialization function (called by InitPostgres) diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c index c460a72b75d9..d77121b63f81 100644 --- a/src/backend/utils/cache/lsyscache.c +++ b/src/backend/utils/cache/lsyscache.c @@ -39,6 +39,7 @@ #include "catalog/pg_subscription.h" #include "catalog/pg_transform.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "utils/array.h" @@ -3854,3 +3855,115 @@ get_subscription_name(Oid subid, bool missing_ok) return subname; } + +/* ---------- PG_VARIABLE CACHE ---------- */ + +/* + * get_varname_varid + * Given name and namespace of variable, look up the OID. + */ +Oid +get_varname_varid(const char *varname, Oid varnamespace) +{ + return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid, + PointerGetDatum(varname), + ObjectIdGetDatum(varnamespace)); +} + +/* + * get_session_variable_name + * Returns a palloc'd copy of the name of a given session variable. + */ +char * +get_session_variable_name(Oid varid) +{ + HeapTuple tup; + Form_pg_variable varform; + char *varname; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + varname = pstrdup(NameStr(varform->varname)); + + ReleaseSysCache(tup); + + return varname; +} + +/* + * get_session_variable_namespace + * Returns the pg_namespace OID associated with a given session variable. + */ +Oid +get_session_variable_namespace(Oid varid) +{ + HeapTuple tup; + Form_pg_variable varform; + Oid varnamespace; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + varnamespace = varform->varnamespace; + + ReleaseSysCache(tup); + + return varnamespace; +} + +/* + * Returns the type of the given session variable. + */ +Oid +get_session_variable_type(Oid varid) +{ + HeapTuple tup; + Form_pg_variable varform; + Oid vartype; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + vartype = varform->vartype; + + ReleaseSysCache(tup); + + return vartype; +} + +/* + * Returns the type, typmod and collid of the given session variable. + */ +void +get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod, + Oid *collid) +{ + HeapTuple tup; + Form_pg_variable varform; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + *typid = varform->vartype; + *typmod = varform->vartypmod; + *collid = varform->varcollation; + + ReleaseSysCache(tup); +} diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c index aa1589e3331d..86360bd6d95f 100644 --- a/src/bin/pg_dump/common.c +++ b/src/bin/pg_dump/common.c @@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr) pg_log_info("reading subscription membership of tables"); getSubscriptionTables(fout); + pg_log_info("reading variables"); + getVariables(fout); + free(inhinfo); /* not needed any longer */ *numTablesPtr = numTables; diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c index 73ce34346b27..cbca7c343a1f 100644 --- a/src/bin/pg_dump/dumputils.c +++ b/src/bin/pg_dump/dumputils.c @@ -514,6 +514,12 @@ do { \ CONVERT_PRIV('r', "SELECT"); CONVERT_PRIV('w', "UPDATE"); } + else if (strcmp(type, "VARIABLE") == 0 || + strcmp(type, "VARIABLES") == 0) + { + CONVERT_PRIV('r', "SELECT"); + CONVERT_PRIV('w', "UPDATE"); + } else abort(); diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h index af0007fb6d2f..76356524af22 100644 --- a/src/bin/pg_dump/pg_backup.h +++ b/src/bin/pg_dump/pg_backup.h @@ -134,12 +134,14 @@ typedef struct _restoreOptions int selFunction; int selTrigger; int selTable; + int selVariable; SimpleStringList indexNames; SimpleStringList functionNames; SimpleStringList schemaNames; SimpleStringList schemaExcludeNames; SimpleStringList triggerNames; SimpleStringList tableNames; + SimpleStringList variableNames; int useDB; ConnParams cparams; /* parameters to use if useDB */ diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c index afa42337b110..e7964131c2e0 100644 --- a/src/bin/pg_dump/pg_backup_archiver.c +++ b/src/bin/pg_dump/pg_backup_archiver.c @@ -3179,6 +3179,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH) !simple_string_list_member(&ropt->triggerNames, te->tag)) return 0; } + else if (strcmp(te->desc, "VARIABLE") == 0) + { + if (!ropt->selVariable) + return 0; + if (ropt->variableNames.head != NULL && + !simple_string_list_member(&ropt->variableNames, te->tag)) + return 0; + } else return 0; } @@ -3742,6 +3750,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te) strcmp(type, "TEXT SEARCH DICTIONARY") == 0 || strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 || strcmp(type, "TYPE") == 0 || + strcmp(type, "VARIABLE") == 0 || strcmp(type, "VIEW") == 0 || /* non-schema-specified objects */ strcmp(type, "DATABASE") == 0 || diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index e2e7975b34e0..255800eca118 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -370,6 +370,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo); static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo); static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo); static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo); +static void dumpVariable(Archive *fout, const VariableInfo *varinfo); static void dumpDatabase(Archive *fout); static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf, const char *dbname, Oid dboid); @@ -5512,6 +5513,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query) return next_possible_free_oid; } +/* + * getVariables + * get information about variables + */ +void +getVariables(Archive *fout) +{ + PQExpBuffer query; + PGresult *res; + VariableInfo *varinfo; + int i_tableoid; + int i_oid; + int i_varname; + int i_varnamespace; + int i_vartype; + int i_vartypname; + int i_varowner; + int i_varcollation; + int i_varacl; + int i_acldefault; + int i, + ntups; + + if (fout->remoteVersion < 180000) + return; + + query = createPQExpBuffer(); + + /* get the variables in current database */ + appendPQExpBuffer(query, + "SELECT v.tableoid, v.oid, v.varname,\n" + " v.varnamespace, v.vartype,\n" + " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n" + " CASE WHEN v.varcollation <> t.typcollation " + " THEN v.varcollation\n" + " ELSE 0\n" + " END AS varcollation,\n" + " v.varowner, v.varacl,\n" + " acldefault('V', v.varowner) AS acldefault\n" + "FROM pg_catalog.pg_variable v\n" + "JOIN pg_catalog.pg_type t " + "ON (v.vartype = t.oid)"); + + res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK); + + ntups = PQntuples(res); + + i_tableoid = PQfnumber(res, "tableoid"); + i_oid = PQfnumber(res, "oid"); + i_varname = PQfnumber(res, "varname"); + i_varnamespace = PQfnumber(res, "varnamespace"); + i_vartype = PQfnumber(res, "vartype"); + i_vartypname = PQfnumber(res, "vartypname"); + i_varcollation = PQfnumber(res, "varcollation"); + + i_varowner = PQfnumber(res, "varowner"); + i_varacl = PQfnumber(res, "varacl"); + i_acldefault = PQfnumber(res, "acldefault"); + + varinfo = pg_malloc(ntups * sizeof(VariableInfo)); + + for (i = 0; i < ntups; i++) + { + TypeInfo *vtype; + + varinfo[i].dobj.objType = DO_VARIABLE; + varinfo[i].dobj.catId.tableoid = + atooid(PQgetvalue(res, i, i_tableoid)); + varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid)); + AssignDumpId(&varinfo[i].dobj); + varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname)); + varinfo[i].dobj.namespace = + findNamespace(atooid(PQgetvalue(res, i, i_varnamespace))); + + varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype)); + varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname)); + varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation)); + + varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl)); + varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault)); + varinfo[i].dacl.privtype = 0; + varinfo[i].dacl.initprivs = NULL; + varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner)); + + /* do not try to dump ACL if no ACL exists */ + if (!PQgetisnull(res, i, i_varacl)) + varinfo[i].dobj.components |= DUMP_COMPONENT_ACL; + + if (strlen(varinfo[i].rolname) == 0) + pg_log_warning("owner of variable \"%s\" appears to be invalid", + varinfo[i].dobj.name); + + /* decide whether we want to dump it */ + selectDumpableObject(&(varinfo[i].dobj), fout); + + vtype = findTypeByOid(varinfo[i].vartype); + addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId); + } + PQclear(res); + + destroyPQExpBuffer(query); +} + +/* + * dumpVariable + * dump the definition of the given session variable + */ +static void +dumpVariable(Archive *fout, const VariableInfo *varinfo) +{ + DumpOptions *dopt = fout->dopt; + + PQExpBuffer delq; + PQExpBuffer query; + char *qualvarname; + const char *vartypname; + Oid varcollation; + + /* skip if not to be dumped */ + if (!varinfo->dobj.dump || !dopt->dumpSchema) + return; + + delq = createPQExpBuffer(); + query = createPQExpBuffer(); + + qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo)); + vartypname = varinfo->vartypname; + varcollation = varinfo->varcollation; + + appendPQExpBuffer(delq, "DROP VARIABLE %s;\n", + qualvarname); + + appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s", + qualvarname, vartypname); + + if (OidIsValid(varcollation)) + { + CollInfo *coll; + + coll = findCollationByOid(varcollation); + if (coll) + appendPQExpBuffer(query, " COLLATE %s", + fmtQualifiedDumpable(coll)); + } + + appendPQExpBuffer(query, ";\n"); + + if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION) + ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId, + ARCHIVE_OPTS(.tag = varinfo->dobj.name, + .namespace = varinfo->dobj.namespace->dobj.name, + .owner = varinfo->rolname, + .description = "VARIABLE", + .section = SECTION_PRE_DATA, + .createStmt = query->data, + .dropStmt = delq->data)); + + /* dump comment if any */ + if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT) + dumpComment(fout, "VARIABLE", qualvarname, + NULL, varinfo->rolname, + varinfo->dobj.catId, 0, varinfo->dobj.dumpId); + + /* dump ACL if any */ + if (varinfo->dobj.dump & DUMP_COMPONENT_ACL) + { + char *qvarname = pg_strdup(fmtId(varinfo->dobj.name)); + + dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE", + qvarname, NULL, + varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname, + &varinfo->dacl); + + free(qvarname); + } + + destroyPQExpBuffer(delq); + destroyPQExpBuffer(query); + + free(qualvarname); +} + static void binary_upgrade_set_type_oids_by_type_oid(Archive *fout, PQExpBuffer upgrade_buffer, @@ -11540,6 +11723,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj) case DO_REL_STATS: dumpRelationStats(fout, (const RelStatsInfo *) dobj); break; + case DO_VARIABLE: + dumpVariable(fout, (VariableInfo *) dobj); + break; case DO_PRE_DATA_BOUNDARY: case DO_POST_DATA_BOUNDARY: /* never dumped, nothing to do */ @@ -15994,6 +16180,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo) case DEFACLOBJ_LARGEOBJECT: type = "LARGE OBJECTS"; break; + case DEFACLOBJ_VARIABLE: + type = "VARIABLES"; + break; default: /* shouldn't get here */ pg_fatal("unrecognized object type in default privileges: %d", @@ -19732,6 +19921,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs, case DO_CONVERSION: case DO_TABLE: case DO_TABLE_ATTACH: + case DO_VARIABLE: case DO_ATTRDEF: case DO_PROCLANG: case DO_CAST: diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h index 7417eab6aefa..1c722e48de5f 100644 --- a/src/bin/pg_dump/pg_dump.h +++ b/src/bin/pg_dump/pg_dump.h @@ -53,6 +53,7 @@ typedef enum DO_TABLE, DO_TABLE_ATTACH, DO_ATTRDEF, + DO_VARIABLE, DO_INDEX, DO_INDEX_ATTACH, DO_STATSEXT, @@ -735,6 +736,19 @@ typedef struct _SubRelInfo char *srsublsn; } SubRelInfo; +/* + * The VariableInfo struct is used to represent session variables + */ +typedef struct _VariableInfo +{ + DumpableObject dobj; + DumpableAcl dacl; + Oid vartype; + char *vartypname; + Oid varcollation; + const char *rolname; /* name of owner, or empty string */ +} VariableInfo; + /* * common utility functions */ @@ -818,5 +832,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[], int numTables); extern void getSubscriptions(Archive *fout); extern void getSubscriptionTables(Archive *fout); +extern void getVariables(Archive *fout); #endif /* PG_DUMP_H */ diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c index 0b0977788f13..b34f3418f64d 100644 --- a/src/bin/pg_dump/pg_dump_sort.c +++ b/src/bin/pg_dump/pg_dump_sort.c @@ -77,6 +77,7 @@ enum dbObjectTypePriorities PRIO_DUMMY_TYPE, PRIO_ATTRDEF, PRIO_LARGE_OBJECT, + PRIO_VARIABLE, PRIO_PRE_DATA_BOUNDARY, /* boundary! */ PRIO_TABLE_DATA, PRIO_SEQUENCE_SET, @@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] = [DO_TABLE] = PRIO_TABLE, [DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH, [DO_ATTRDEF] = PRIO_ATTRDEF, + [DO_VARIABLE] = PRIO_VARIABLE, [DO_INDEX] = PRIO_INDEX, [DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH, [DO_STATSEXT] = PRIO_STATSEXT, @@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize) "RELATION STATISTICS FOR %s (ID %d OID %u)", obj->name, obj->dumpId, obj->catId.oid); return; + case DO_VARIABLE: + snprintf(buf, bufsize, + "VARIABLE %s (ID %d OID %u)", + obj->name, obj->dumpId, obj->catId.oid); + return; } /* shouldn't get here */ snprintf(buf, bufsize, diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl index 55d892d9c162..94eefb7c5306 100644 --- a/src/bin/pg_dump/t/002_pg_dump.pl +++ b/src/bin/pg_dump/t/002_pg_dump.pl @@ -901,6 +901,16 @@ unlike => { no_privs => 1, }, }, + 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC' + => { + create_order => 56, + create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;', + regexp => qr/^ + \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm, + like => { %full_runs, section_post_data => 1, }, + unlike => { no_privs => 1, }, + }, + 'ALTER ROLE regress_dump_test_role' => { regexp => qr/^ \QALTER ROLE regress_dump_test_role WITH \E @@ -1869,6 +1879,23 @@ }, }, + 'COMMENT ON VARIABLE dump_test.variable1' => { + create_order => 71, + create_sql => 'COMMENT ON VARIABLE dump_test.variable1 + IS \'comment on variable\';', + regexp => + qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m, + like => { + %full_runs, + %dump_test_schema_runs, + section_pre_data => 1, + }, + unlike => { + exclude_dump_test_schema => 1, + only_dump_measurement => 1, + }, + }, + 'COPY test_table' => { create_order => 4, create_sql => 'INSERT INTO dump_test.test_table (col1) ' @@ -4177,6 +4204,24 @@ }, }, + 'CREATE VARIABLE test_variable' => { + all_runs => 1, + catch_all => 'CREATE ... commands', + create_order => 61, + create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;', + regexp => qr/^ + \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm, + like => { + %full_runs, + %dump_test_schema_runs, + section_pre_data => 1, + }, + unlike => { + exclude_dump_test_schema => 1, + only_dump_measurement => 1, + }, + }, + 'CREATE VIEW test_view' => { create_order => 61, create_sql => 'CREATE VIEW dump_test.test_view @@ -4641,6 +4686,25 @@ like => {}, }, + 'GRANT SELECT ON VARIABLE dump_test.variable1' => { + create_order => 73, + create_sql => + 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;', + regexp => qr/^ + \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E + /xm, + like => { + %full_runs, + %dump_test_schema_runs, + section_pre_data => 1, + }, + unlike => { + exclude_dump_test_schema => 1, + no_privs => 1, + only_dump_measurement => 1, + }, + }, + 'REFRESH MATERIALIZED VIEW matview' => { regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m, like => diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c index 81a5ba844ba0..a171bf5f3b48 100644 --- a/src/bin/psql/command.c +++ b/src/bin/psql/command.c @@ -1246,6 +1246,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd) break; } break; + case 'V': /* Variables */ + success = listVariables(pattern, show_verbose); + break; case 'x': /* Extensions */ if (show_verbose) success = listExtensionContents(pattern); diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c index 1d08268393e3..ad46ca4f9bed 100644 --- a/src/bin/psql/describe.c +++ b/src/bin/psql/describe.c @@ -1223,7 +1223,7 @@ listDefaultACLs(const char *pattern) "SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n" " n.nspname AS \"%s\",\n" " CASE d.defaclobjtype " - " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s'" + " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s'" " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n" " ", gettext_noop("Owner"), @@ -1240,6 +1240,8 @@ listDefaultACLs(const char *pattern) gettext_noop("schema"), DEFACLOBJ_LARGEOBJECT, gettext_noop("large object"), + DEFACLOBJ_VARIABLE, + gettext_noop("session variable"), gettext_noop("Type")); printACLColumn(&buf, "d.defaclacl"); @@ -5313,6 +5315,102 @@ listSchemas(const char *pattern, bool verbose, bool showSystem) return false; } +/* + * \dV + * + * listVariables() + */ +bool +listVariables(const char *pattern, bool verbose) +{ + PQExpBufferData buf; + PGresult *res; + printQueryOpt myopt = pset.popt; + static const bool translate_columns[] = {false, false, false, false, false, false, false}; + + if (pset.sversion < 180000) + { + char sverbuf[32]; + + pg_log_error("The server (version %s) does not support session variables.", + formatPGVersionNumber(pset.sversion, false, + sverbuf, sizeof(sverbuf))); + return true; + } + + initPQExpBuffer(&buf); + + printfPQExpBuffer(&buf, + "SELECT n.nspname as \"%s\",\n" + " v.varname as \"%s\",\n" + " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n" + " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n" + " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n" + " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n", + gettext_noop("Schema"), + gettext_noop("Name"), + gettext_noop("Type"), + gettext_noop("Collation"), + gettext_noop("Owner")); + + if (verbose) + { + appendPQExpBufferStr(&buf, ",\n "); + printACLColumn(&buf, "v.varacl"); + appendPQExpBuffer(&buf, + ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"", + gettext_noop("Description")); + } + + appendPQExpBufferStr(&buf, + "\nFROM pg_catalog.pg_variable v" + "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace"); + + appendPQExpBufferStr(&buf, "\nWHERE true\n"); + if (!pattern) + appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n" + " AND n.nspname <> 'information_schema'\n"); + + if (!validateSQLNamePattern(&buf, pattern, true, false, + "n.nspname", "v.varname", NULL, + "pg_catalog.pg_variable_is_visible(v.oid)", + NULL, 3)) + return false; + + appendPQExpBufferStr(&buf, "ORDER BY 1,2;"); + + res = PSQLexec(buf.data); + termPQExpBuffer(&buf); + if (!res) + return false; + + /* + * Most functions in this file are content to print an empty table when + * there are no matching objects. We intentionally deviate from that + * here, but only in !quiet mode, for historical reasons. + */ + if (PQntuples(res) == 0 && !pset.quiet) + { + if (pattern) + pg_log_error("Did not find any session variable named \"%s\".", + pattern); + else + pg_log_error("Did not find any session variables."); + } + else + { + myopt.nullPrint = NULL; + myopt.title = _("List of variables"); + myopt.translate_header = true; + myopt.translate_columns = translate_columns; + myopt.n_translate_columns = lengthof(translate_columns); + + printQuery(res, &myopt, pset.queryFout, false, pset.logfile); + } + + PQclear(res); + return true; +} /* * \dFp diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h index 18ecaa60949d..55ced4aab7b0 100644 --- a/src/bin/psql/describe.h +++ b/src/bin/psql/describe.h @@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern, /* \dl or \lo_list */ extern bool listLargeObjects(bool verbose); +/* \dV */ +extern bool listVariables(const char *pattern, bool varbose); + #endif /* DESCRIBE_H */ diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c index 403b51325a72..81886eb9725d 100644 --- a/src/bin/psql/help.c +++ b/src/bin/psql/help.c @@ -261,6 +261,7 @@ slashUsage(unsigned short int pager) HELP0(" \\dT[Sx+] [PATTERN] list data types\n"); HELP0(" \\du[Sx+] [PATTERN] list roles\n"); HELP0(" \\dv[Sx+] [PATTERN] list views\n"); + HELP0(" \\dV[x+] [PATTERN] list session variables\n"); HELP0(" \\dx[x+] [PATTERN] list extensions\n"); HELP0(" \\dX[x] [PATTERN] list extended statistics\n"); HELP0(" \\dy[x+] [PATTERN] list event triggers\n"); diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c index c916b9299a80..94bd86c01b93 100644 --- a/src/bin/psql/tab-complete.in.c +++ b/src/bin/psql/tab-complete.in.c @@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = { .refnamespace = "c1.relnamespace", }; +static const SchemaQuery Query_for_list_of_variables = { + .min_server_version = 180000, + .catname = "pg_catalog.pg_variable v", + .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)", + .namespace = "v.varnamespace", + .result = "v.varname", +}; /* * Queries to get lists of names of various kinds of things, possibly @@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = { * TABLE ... */ {"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing}, {"USER MAPPING FOR", NULL, NULL, NULL}, + {"VARIABLE", NULL, NULL, &Query_for_list_of_variables}, {"VIEW", NULL, NULL, &Query_for_list_of_views}, {NULL} /* end of list */ }; @@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end) "\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL", "\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt", "\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds", - "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", + "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV", "\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding", "\\endif", "\\endpipeline", "\\errverbose", "\\ev", "\\f", "\\flush", "\\flushrequest", @@ -2586,6 +2594,9 @@ match_previous_words(int pattern_id, "ALL"); else if (Matches("ALTER", "SYSTEM", "SET", MatchAny)) COMPLETE_WITH("TO"); + /* ALTER VARIABLE */ + else if (Matches("ALTER", "VARIABLE", MatchAny)) + COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA"); /* ALTER VIEW */ else if (Matches("ALTER", "VIEW", MatchAny)) COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET"); @@ -3169,7 +3180,7 @@ match_previous_words(int pattern_id, "ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER", "STATISTICS", "SUBSCRIPTION", "TABLE", "TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR", - "TRIGGER", "TYPE", "VIEW"); + "TRIGGER", "TYPE", "VARIABLE", "VIEW"); else if (Matches("COMMENT", "ON", "ACCESS", "METHOD")) COMPLETE_WITH_QUERY(Query_for_list_of_access_methods); else if (Matches("COMMENT", "ON", "CONSTRAINT")) @@ -3979,6 +3990,13 @@ match_previous_words(int pattern_id, else if (TailMatches("=", MatchAnyExcept("*)"))) COMPLETE_WITH(",", ")"); } +/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */ + /* Complete CREATE VARIABLE with AS */ + else if (TailMatches("CREATE", "VARIABLE", MatchAny)) + COMPLETE_WITH("AS"); + else if (TailMatches("VARIABLE", MatchAny, "AS")) + /* Complete CREATE VARIABLE with AS types */ + COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes); /* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */ /* Complete CREATE [ OR REPLACE ] VIEW with AS or WITH */ @@ -4256,6 +4274,12 @@ match_previous_words(int pattern_id, else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny)) COMPLETE_WITH("CASCADE", "RESTRICT"); + /* DROP VARIABLE */ + else if (Matches("DROP", "VARIABLE")) + COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables); + else if (Matches("DROP", "VARIABLE", MatchAny)) + COMPLETE_WITH("CASCADE", "RESTRICT"); + /* EXECUTE */ else if (Matches("EXECUTE")) COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements); @@ -4457,7 +4481,9 @@ match_previous_words(int pattern_id, * objects supported. */ if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES")) - COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "LARGE OBJECTS"); + COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", + "ROUTINES", "TYPES", "SCHEMAS", "LARGE OBJECTS", + "VARIABLES"); else COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables, "ALL FUNCTIONS IN SCHEMA", @@ -4465,6 +4491,7 @@ match_previous_words(int pattern_id, "ALL ROUTINES IN SCHEMA", "ALL SEQUENCES IN SCHEMA", "ALL TABLES IN SCHEMA", + "ALL VARIABLES IN SCHEMA", "DATABASE", "DOMAIN", "FOREIGN DATA WRAPPER", @@ -4479,7 +4506,8 @@ match_previous_words(int pattern_id, "SEQUENCE", "TABLE", "TABLESPACE", - "TYPE"); + "TYPE", + "VARIABLE"); } else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") || TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL")) @@ -4487,7 +4515,8 @@ match_previous_words(int pattern_id, "PROCEDURES IN SCHEMA", "ROUTINES IN SCHEMA", "SEQUENCES IN SCHEMA", - "TABLES IN SCHEMA"); + "TABLES IN SCHEMA", + "VARIABLES IN SCHEMA"); else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") || TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN")) COMPLETE_WITH("DATA WRAPPER", "SERVER"); @@ -4523,6 +4552,8 @@ match_previous_words(int pattern_id, COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces); else if (TailMatches("TYPE")) COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes); + else if (TailMatches("VARIABLE")) + COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables); else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny)) COMPLETE_WITH("TO"); else @@ -4825,7 +4856,7 @@ match_previous_words(int pattern_id, /* PREPARE xx AS */ else if (Matches("PREPARE", MatchAny, "AS")) - COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM"); + COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET"); /* * PREPARE TRANSACTION is missing on purpose. It's intended for transaction @@ -5314,6 +5345,8 @@ match_previous_words(int pattern_id, COMPLETE_WITH_QUERY(Query_for_list_of_roles); else if (TailMatchesCS("\\dv*")) COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views); + else if (TailMatchesCS("\\dV*")) + COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables); else if (TailMatchesCS("\\dx*")) COMPLETE_WITH_QUERY(Query_for_list_of_extensions); else if (TailMatchesCS("\\dX*")) diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile index 2bbc7805fe37..f98760de635a 100644 --- a/src/include/catalog/Makefile +++ b/src/include/catalog/Makefile @@ -81,7 +81,8 @@ CATALOG_HEADERS := \ pg_publication_namespace.h \ pg_publication_rel.h \ pg_subscription.h \ - pg_subscription_rel.h + pg_subscription_rel.h \ + pg_variable.h GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h) diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build index ec1cf467f6fa..81398efa7c9b 100644 --- a/src/include/catalog/meson.build +++ b/src/include/catalog/meson.build @@ -69,6 +69,7 @@ catalog_headers = [ 'pg_publication_rel.h', 'pg_subscription.h', 'pg_subscription_rel.h', + 'pg_variable.h', ] # The .dat files we need can just be listed alphabetically. diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h index 8c7ccc69a3c3..bdac0c13beca 100644 --- a/src/include/catalog/namespace.h +++ b/src/include/catalog/namespace.h @@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname); extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok); extern bool TypeIsVisible(Oid typid); +extern bool VariableIsVisible(Oid varid); + extern FuncCandidateList FuncnameGetCandidates(List *names, int nargs, List *argnames, bool expand_variadic, @@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context); extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path); extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path); +extern List *NamesFromList(List *names); +extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok); +extern Oid LookupVariableFromNameList(List *names, bool missing_ok); + extern Oid get_collation_oid(List *collname, bool missing_ok); extern Oid get_conversion_oid(List *conname, bool missing_ok); extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding); diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h index ce6e5098eaf0..087d35b943d7 100644 --- a/src/include/catalog/pg_default_acl.h +++ b/src/include/catalog/pg_default_acl.h @@ -69,6 +69,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8); #define DEFACLOBJ_TYPE 'T' /* type */ #define DEFACLOBJ_NAMESPACE 'n' /* namespace */ #define DEFACLOBJ_LARGEOBJECT 'L' /* large object */ +#define DEFACLOBJ_VARIABLE 'V' /* variable */ #endif /* EXPOSE_TO_CLIENT_CODE */ diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 62beb71da288..da772ff9e178 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5466,6 +5466,26 @@ prorettype => 'bool', proargtypes => 'oid oid text', prosrc => 'has_largeobject_privilege_id_id' }, +{ oid => '9613', descr => 'user privilege on session variable by username, seq name', + proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool', + proargtypes => 'name text text', + prosrc => 'has_session_variable_privilege_name_name' }, +{ oid => '9614', descr => 'user privilege on session variable by username, seq oid', + proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool', + proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' }, +{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name', + proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool', + proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' }, +{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid', + proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool', + proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' }, +{ oid => '9617', descr => 'current user privilege on session variable by seq name', + proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool', + proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' }, +{ oid => '9618', descr => 'current user privilege on session variable by seq oid', + proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool', + proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' }, + { oid => '3355', descr => 'I/O', proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct', proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' }, @@ -6676,6 +6696,9 @@ proname => 'pg_collation_is_visible', procost => '10', provolatile => 's', prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_collation_is_visible' }, +{ oid => '9999', descr => 'is session variable visible in search path?', + proname => 'pg_variable_is_visible', procost => '10', provolatile => 's', + prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' }, { oid => '2854', descr => 'get OID of current session\'s temp schema, if any', proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r', diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h new file mode 100644 index 000000000000..3d3c6eb24b58 --- /dev/null +++ b/src/include/catalog/pg_variable.h @@ -0,0 +1,81 @@ +/*------------------------------------------------------------------------- + * + * pg_variable.h + * definition of session variables system catalog (pg_variables) + * + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/catalog/pg_variable.h + * + * NOTES + * The Catalog.pm module reads this file and derives schema + * information. + * + *------------------------------------------------------------------------- + */ +#ifndef PG_VARIABLE_H +#define PG_VARIABLE_H + +#include "catalog/genbki.h" +#include "catalog/objectaddress.h" +#include "catalog/pg_variable_d.h" +#include "utils/acl.h" + +/* ---------------- + * pg_variable definition. cpp turns this into + * typedef struct FormData_pg_variable + * ---------------- + */ +CATALOG(pg_variable,9222,VariableRelationId) +{ + Oid oid; /* oid */ + + /* OID of entry in pg_type for variable's type */ + Oid vartype BKI_LOOKUP(pg_type); + + /* variable name */ + NameData varname; + + /* OID of namespace containing variable class */ + Oid varnamespace BKI_LOOKUP(pg_namespace); + + /* variable owner */ + Oid varowner BKI_LOOKUP(pg_authid); + + /* typmod for variable's type */ + int32 vartypmod BKI_DEFAULT(-1); + + /* variable collation */ + Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation); + + +#ifdef CATALOG_VARLEN /* variable-length fields start here */ + + /* access permissions */ + aclitem varacl[1] BKI_DEFAULT(_null_); + +#endif +} FormData_pg_variable; + +/* ---------------- + * Form_pg_variable corresponds to a pointer to a tuple with + * the format of the pg_variable relation. + * ---------------- + */ +typedef FormData_pg_variable *Form_pg_variable; + +DECLARE_TOAST(pg_variable, 9223, 9224); + +DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops)); +DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops)); + +extern ObjectAddress CreateVariable(ParseState *pstate, + CreateSessionVarStmt *stmt); +extern void DropVariableById(Oid varid); + +MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8); +MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8); + +#endif /* PG_VARIABLE_H */ diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 4610fc61293b..ae4b6a3862cf 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -2365,6 +2365,7 @@ typedef enum ObjectType OBJECT_TSTEMPLATE, OBJECT_TYPE, OBJECT_USER_MAPPING, + OBJECT_VARIABLE, OBJECT_VIEW, } ObjectType; @@ -3515,6 +3516,21 @@ typedef struct AlterStatsStmt bool missing_ok; /* skip error if statistics object is missing */ } AlterStatsStmt; + +/* ---------------------- + * {Create|Alter} VARIABLE Statement + * ---------------------- + */ +typedef struct CreateSessionVarStmt +{ + NodeTag type; + RangeVar *variable; /* the variable to create */ + TypeName *typeName; /* the type of variable */ + CollateClause *collClause; + bool if_not_exists; /* do nothing if it already exists */ +} CreateSessionVarStmt; + + /* ---------------------- * Create Function Statement * ---------------------- diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h index a4af3f717a11..0ea0265de7c1 100644 --- a/src/include/parser/kwlist.h +++ b/src/include/parser/kwlist.h @@ -486,6 +486,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL) PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL) +PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL) +PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL) PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL) diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h index d250a714d597..ea86954dded7 100644 --- a/src/include/tcop/cmdtaglist.h +++ b/src/include/tcop/cmdtaglist.h @@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false) PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false) PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false) PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false) +PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false) PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false) PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false) PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false) @@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false) PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false) PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false) PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false) +PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false) PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false) PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false) PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false) @@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false) PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false) PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false) PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false) +PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false) PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false) PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false) PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false) diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h index 01ae5b719fd7..5e1a8a82e90c 100644 --- a/src/include/utils/acl.h +++ b/src/include/utils/acl.h @@ -169,6 +169,7 @@ typedef struct ArrayType Acl; #define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE) #define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE) #define ACL_ALL_RIGHTS_TYPE (ACL_USAGE) +#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE) /* operation codes for pg_*_aclmask */ typedef enum diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h index fa7c7e0323b1..f4a851dc2326 100644 --- a/src/include/utils/lsyscache.h +++ b/src/include/utils/lsyscache.h @@ -139,6 +139,7 @@ extern char get_func_prokind(Oid funcid); extern bool get_func_leakproof(Oid funcid); extern RegProcedure get_func_support(Oid funcid); extern Oid get_relname_relid(const char *relname, Oid relnamespace); +extern Oid get_varname_varid(const char *varname, Oid varnamespace); extern char *get_rel_name(Oid relid); extern Oid get_rel_namespace(Oid relid); extern Oid get_rel_type_id(Oid relid); @@ -211,6 +212,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok); extern Oid get_subscription_oid(const char *subname, bool missing_ok); extern char *get_subscription_name(Oid subid, bool missing_ok); +extern char *get_session_variable_name(Oid varid); +extern Oid get_session_variable_namespace(Oid varid); +extern Oid get_session_variable_type(Oid varid); +extern void get_session_variable_type_typmod_collid(Oid varid, + Oid *typid, + int32 *typmod, + Oid *collid); + #define type_is_array(typid) (get_element_type(typid) != InvalidOid) /* type_is_array_domain accepts both plain arrays and domains over arrays */ #define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid) diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out index 75a078ada9e1..cd8e4412fa92 100644 --- a/src/test/regress/expected/dependency.out +++ b/src/test/regress/expected/dependency.out @@ -151,3 +151,20 @@ owner of type deptest_t DROP OWNED BY regress_dep_user2, regress_dep_user0; DROP USER regress_dep_user2; DROP USER regress_dep_user0; +-- dependency on type +CREATE DOMAIN vardomain AS int; +CREATE TYPE vartype AS (a int, b int, c vardomain); +CREATE VARIABLE var1 AS vartype; +-- should fail +DROP DOMAIN vardomain; +ERROR: cannot drop type vardomain because other objects depend on it +DETAIL: column c of composite type vartype depends on type vardomain +HINT: Use DROP ... CASCADE to drop the dependent objects too. +DROP TYPE vartype; +ERROR: cannot drop type vartype because other objects depend on it +DETAIL: session variable var1 depends on type vartype +HINT: Use DROP ... CASCADE to drop the dependent objects too. +-- clean up +DROP VARIABLE var1; +DROP TYPE vartype; +DROP DOMAIN vardomain; diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out index 215eb899be3e..d99533214021 100644 --- a/src/test/regress/expected/oidjoins.out +++ b/src/test/regress/expected/oidjoins.out @@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid} NOTICE: checking pg_subscription {subowner} => pg_authid {oid} NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid} NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid} +NOTICE: checking pg_variable {vartype} => pg_type {oid} +NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid} +NOTICE: checking pg_variable {varowner} => pg_authid {oid} +NOTICE: checking pg_variable {varcollation} => pg_collation {oid} diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out index cf48ae6d0c2e..fd6b2a6b8c8a 100644 --- a/src/test/regress/expected/psql.out +++ b/src/test/regress/expected/psql.out @@ -6023,6 +6023,30 @@ COMMIT; # final ON_ERROR_ROLLBACK: off DROP TABLE bla; DROP FUNCTION psql_error; +-- session variable test +CREATE ROLE regress_variable_owner; +SET ROLE TO regress_variable_owner; +CREATE VARIABLE var1 AS varchar COLLATE "C"; +\dV+ var1 + List of variables + Schema | Name | Type | Collation | Owner | Access privileges | Description +--------+------+-------------------+-----------+------------------------+-------------------+------------- + public | var1 | character varying | C | regress_variable_owner | | +(1 row) + +GRANT SELECT ON VARIABLE var1 TO PUBLIC; +COMMENT ON VARIABLE var1 IS 'some description'; +\dV+ var1 + List of variables + Schema | Name | Type | Collation | Owner | Access privileges | Description +--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------ + public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description + | | | | | =r/regress_variable_owner | +(1 row) + +DROP VARIABLE var1; +SET ROLE TO DEFAULT; +DROP ROLE regress_variable_owner; -- check describing invalid multipart names \dA regression.heap improper qualified name (too many dotted names): regression.heap @@ -6244,6 +6268,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat improper qualified name (too many dotted names): regression.myevt \dy nonesuch.myevt improper qualified name (too many dotted names): nonesuch.myevt +\dV host.regression.public.var +improper qualified name (too many dotted names): host.regression.public.var +\dV regression|mydb.public.var +cross-database references are not implemented: regression|mydb.public.var +\dV nonesuch.public.var +cross-database references are not implemented: nonesuch.public.var -- check that dots within quoted name segments are not counted \dA "no.such.access.method" List of access methods @@ -6478,6 +6508,12 @@ List of schemas ------+-------+-------+---------+----------+------ (0 rows) +\dV "no.such.variable" + List of variables + Schema | Name | Type | Collation | Owner +--------+------+------+-----------+------- +(0 rows) + -- again, but with dotted schema qualifications. \dA "no.such.schema"."no.such.access.method" improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method" @@ -6647,6 +6683,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta \dy "no.such.schema"."no.such.event.trigger" improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger" +\dV "no.such.schema"."no.such.variable" + List of variables + Schema | Name | Type | Collation | Owner +--------+------+------+-----------+------- +(0 rows) + -- again, but with current database and dotted schema qualifications. \dt regression."no.such.schema"."no.such.table.relation" List of tables @@ -6780,6 +6822,12 @@ List of text search templates --------+------+------------+-----------+--------------+----- (0 rows) +\dV regression."no.such.schema"."no.such.variable" + List of variables + Schema | Name | Type | Collation | Owner +--------+------+------+-----------+------- +(0 rows) + -- again, but with dotted database and dotted schema qualifications. \dt "no.such.database"."no.such.schema"."no.such.table.relation" cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation" @@ -6827,6 +6875,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type" \dX "no.such.database"."no.such.schema"."no.such.extended.statistics" cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics" +\dV "no.such.database"."no.such.schema"."no.such.variable" +cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable" -- check \drg and \du CREATE ROLE regress_du_role0; CREATE ROLE regress_du_role1; diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out new file mode 100644 index 000000000000..c36660ce6d32 --- /dev/null +++ b/src/test/regress/expected/session_variables.out @@ -0,0 +1,433 @@ +CREATE ROLE regress_variable_owner; +SET log_statement TO ddl; +-- should be ok +CREATE VARIABLE var1 AS int; +-- should fail, pseudotypes are not allowed +CREATE VARIABLE var2 AS anyelement; +ERROR: session variable cannot be pseudo-type anyelement +-- should be ok, do nothing +DROP VARIABLE IF EXISTS var2; +NOTICE: session variable "var2" does not exist, skipping +-- do nothing +CREATE VARIABLE IF NOT EXISTS var1 AS int; +NOTICE: session variable "var1" already exists, skipping +-- should fail +CREATE VARIABLE var1 AS int; +ERROR: session variable "var1" already exists +-- should be ok +DROP VARIABLE IF EXISTS var1; +-- the variable can use composite types +CREATE TABLE t1 (a int, b int); +CREATE VARIABLE var1 AS t1; +-- should fail +DROP TABLE t1; +ERROR: cannot drop table t1 because other objects depend on it +DETAIL: session variable var1 depends on type t1 +HINT: Use DROP ... CASCADE to drop the dependent objects too. +-- should be ok +ALTER TABLE t1 ADD COLUMN c int; +-- should fail +ALTER TABLE t1 ALTER COLUMN b TYPE numeric; +ERROR: cannot alter table "t1" because session variable "public.var1" uses it +DROP VARIABLE var1; +DROP TABLE t1; +CREATE TYPE t1 AS (a int, b int); +CREATE VARIABLE var1 AS t1; +-- should fail +DROP TYPE t1; +ERROR: cannot drop type t1 because other objects depend on it +DETAIL: session variable var1 depends on type t1 +HINT: Use DROP ... CASCADE to drop the dependent objects too. +-- should be ok +ALTER TYPE t1 ADD ATTRIBUTE c int; +-- should fail +ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric; +ERROR: cannot alter type "t1" because session variable "public.var1" uses it +DROP VARIABLE var1; +DROP TYPE t1; +SET log_statement TO default; +CREATE DOMAIN testvar_domain AS int; +CREATE TYPE testvar_type AS (a testvar_domain); +CREATE VARIABLE var1 AS testvar_domain; +-- should fail +ALTER DOMAIN testvar_domain ADD CHECK(value <> 100); +ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it +DROP VARIABLE var1; +CREATE VARIABLE var1 AS testvar_type; +-- should fail +ALTER DOMAIN testvar_domain ADD CHECK(value <> 100); +ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it +DROP VARIABLE var1; +-- should be ok +ALTER DOMAIN testvar_domain ADD CHECK(value <> 100); +DROP TYPE testvar_type; +DROP TYPE testvar_domain; +-- check event trigger support +CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped() +RETURNS event_trigger +AS $$ +DECLARE r record; +BEGIN + FOR r IN SELECT * from pg_event_trigger_dropped_objects() + LOOP + CONTINUE WHEN NOT r.normal AND NOT r.original; + + RAISE NOTICE + 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%', + r.original, r.normal, r.is_temporary, r.object_type, + r.object_identity, r.address_names, r.address_args; + END LOOP; +END; +$$ LANGUAGE plpgsql; +CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop + WHEN TAG IN ('DROP VARIABLE') + EXECUTE PROCEDURE svar_event_trigger_report_dropped(); +CREATE VARIABLE var1 AS int; +DROP VARIABLE var1; +NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={} +DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped; +-- check comment on variable +CREATE VARIABLE var1 AS int; +COMMENT ON VARIABLE var1 IS 'some variable comment'; +SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1'; + obj_description +----------------------- + some variable comment +(1 row) + +DROP VARIABLE var1; +-- check the object address of all session variables +CREATE SCHEMA vartest1; +CREATE SCHEMA vartest2; +CREATE VARIABLE vartest1.svartest_var1 AS int; +CREATE VARIABLE vartest2.svartest_var1 AS int; +SELECT + e.varname, + pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr, + b.type, b.object_names, b.object_args, + pg_identify_object(a.classid, a.objid, a.objsubid) as ident +FROM pg_variable as e, + LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b, + LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a +WHERE e.varname LIKE 'svartest_var%'; + varname | descr | type | object_names | object_args | ident +---------------+-----------------------------------------+------------------+--------------------------+-------------+-------------------------------------------------------------------- + svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1) + svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1) +(2 rows) + +DROP SCHEMA vartest1 CASCADE; +NOTICE: drop cascades to session variable vartest1.svartest_var1 +DROP SCHEMA vartest2 CASCADE; +NOTICE: drop cascades to session variable vartest2.svartest_var1 +-- check access rights and supported ALTER +CREATE SCHEMA svartest; +GRANT ALL ON SCHEMA svartest TO regress_variable_owner; +CREATE VARIABLE svartest.var1 AS int; +CREATE ROLE regress_variable_reader; +GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader; +REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader; +ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner; +ALTER VARIABLE svartest.var1 RENAME TO varxx; +ALTER VARIABLE svartest.varxx SET SCHEMA public; +DROP VARIABLE public.varxx; +ALTER DEFAULT PRIVILEGES + FOR ROLE regress_variable_owner + IN SCHEMA svartest + GRANT SELECT ON VARIABLES TO regress_variable_reader; +-- creating variable with default privileges +SET ROLE TO regress_variable_owner; +CREATE VARIABLE svartest.var1 AS int; +SET ROLE TO DEFAULT; +-- should be ok. since ALTER DEFAULT PRIVILEGES +-- allow regress_variable_reader to have SELECT priviledge +SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +DROP VARIABLE svartest.var1; +DROP SCHEMA svartest; +DROP ROLE regress_variable_reader; +-- +-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY +-- +CREATE ROLE regress_variable_r1; +CREATE ROLE regress_variable_r2; +SET ROLE TO regress_variable_owner; +CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner +GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION; +SET ROLE TO regress_variable_r1; +GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION; +SET ROLE TO DEFAULT; +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE; +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SET ROLE TO regress_variable_owner; +GRANT SELECT ON VARIABLE var1 TO regress_variable_r2; +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner; +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SET ROLE TO DEFAULT; +DROP VARIABLE var1; +-- +-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY +-- +-- +-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA +-- +CREATE SCHEMA svartest; +GRANT ALL ON SCHEMA svartest TO regress_variable_owner; +SET ROLE TO regress_variable_owner; +CREATE VARIABLE svartest.var1 AS int; +CREATE VARIABLE svartest.var2 AS int; +GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1; +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1; +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SET ROLE TO DEFAULT; +DROP VARIABLE svartest.var1; +DROP VARIABLE svartest.var2; +DROP SCHEMA svartest; +-- +-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA +-- +-- +-- function has_session_variable_privilege have various kind of signature. +-- the following are extensive test for it. +-- +SET ROLE TO regress_variable_owner; +CREATE VARIABLE public.var1 AS int; +SET search_path TO public; +GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1; +GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2; +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL; + ?column? +---------- + t +(1 row) + +SET ROLE TO regress_variable_r1; +SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT oid AS varid + FROM pg_variable + WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset +SELECT has_session_variable_privilege('var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f + has_session_variable_privilege +-------------------------------- + f +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t + has_session_variable_privilege +-------------------------------- + t +(1 row) + +-- +-- end of function has_session_variable_privilege tests. +-- +SET ROLE TO DEFAULT; +SET search_path TO DEFAULT; +DROP VARIABLE public.var1; +DROP ROLE regress_variable_r1; +DROP ROLE regress_variable_r2; +DROP ROLE regress_variable_owner; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index a424be2a6bf0..b96a8de001db 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -115,7 +115,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson # NB: temp.sql does reconnects which transiently use 2 connections, # so keep this parallel group to at most 19 tests # ---------- -test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml +test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables # ---------- # Another group of parallel tests diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql index 8d74ed7122c2..6c18b7f840a1 100644 --- a/src/test/regress/sql/dependency.sql +++ b/src/test/regress/sql/dependency.sql @@ -114,3 +114,17 @@ DROP USER regress_dep_user2; DROP OWNED BY regress_dep_user2, regress_dep_user0; DROP USER regress_dep_user2; DROP USER regress_dep_user0; + +-- dependency on type +CREATE DOMAIN vardomain AS int; +CREATE TYPE vartype AS (a int, b int, c vardomain); +CREATE VARIABLE var1 AS vartype; + +-- should fail +DROP DOMAIN vardomain; +DROP TYPE vartype; + +-- clean up +DROP VARIABLE var1; +DROP TYPE vartype; +DROP DOMAIN vardomain; diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql index 1a8a83462f02..b567ee1eee2e 100644 --- a/src/test/regress/sql/psql.sql +++ b/src/test/regress/sql/psql.sql @@ -1643,6 +1643,19 @@ COMMIT; DROP TABLE bla; DROP FUNCTION psql_error; +-- session variable test +CREATE ROLE regress_variable_owner; +SET ROLE TO regress_variable_owner; +CREATE VARIABLE var1 AS varchar COLLATE "C"; +\dV+ var1 +GRANT SELECT ON VARIABLE var1 TO PUBLIC; +COMMENT ON VARIABLE var1 IS 'some description'; +\dV+ var1 +DROP VARIABLE var1; + +SET ROLE TO DEFAULT; +DROP ROLE regress_variable_owner; + -- check describing invalid multipart names \dA regression.heap \dA nonesuch.heap @@ -1754,6 +1767,9 @@ DROP FUNCTION psql_error; \dX nonesuch.public.func_deps_stat \dy regression.myevt \dy nonesuch.myevt +\dV host.regression.public.var +\dV regression|mydb.public.var +\dV nonesuch.public.var -- check that dots within quoted name segments are not counted \dA "no.such.access.method" @@ -1795,6 +1811,8 @@ DROP FUNCTION psql_error; \dx "no.such.installed.extension" \dX "no.such.extended.statistics" \dy "no.such.event.trigger" +\dV "no.such.variable" + -- again, but with dotted schema qualifications. \dA "no.such.schema"."no.such.access.method" @@ -1835,6 +1853,7 @@ DROP FUNCTION psql_error; \dx "no.such.schema"."no.such.installed.extension" \dX "no.such.schema"."no.such.extended.statistics" \dy "no.such.schema"."no.such.event.trigger" +\dV "no.such.schema"."no.such.variable" -- again, but with current database and dotted schema qualifications. \dt regression."no.such.schema"."no.such.table.relation" @@ -1859,6 +1878,7 @@ DROP FUNCTION psql_error; \dP regression."no.such.schema"."no.such.partitioned.relation" \dT regression."no.such.schema"."no.such.data.type" \dX regression."no.such.schema"."no.such.extended.statistics" +\dV regression."no.such.schema"."no.such.variable" -- again, but with dotted database and dotted schema qualifications. \dt "no.such.database"."no.such.schema"."no.such.table.relation" @@ -1884,6 +1904,7 @@ DROP FUNCTION psql_error; \dP "no.such.database"."no.such.schema"."no.such.partitioned.relation" \dT "no.such.database"."no.such.schema"."no.such.data.type" \dX "no.such.database"."no.such.schema"."no.such.extended.statistics" +\dV "no.such.database"."no.such.schema"."no.such.variable" -- check \drg and \du CREATE ROLE regress_du_role0; diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql new file mode 100644 index 000000000000..eeb0f94ca3cd --- /dev/null +++ b/src/test/regress/sql/session_variables.sql @@ -0,0 +1,297 @@ +CREATE ROLE regress_variable_owner; + +SET log_statement TO ddl; + +-- should be ok +CREATE VARIABLE var1 AS int; + +-- should fail, pseudotypes are not allowed +CREATE VARIABLE var2 AS anyelement; + +-- should be ok, do nothing +DROP VARIABLE IF EXISTS var2; + +-- do nothing +CREATE VARIABLE IF NOT EXISTS var1 AS int; + +-- should fail +CREATE VARIABLE var1 AS int; + +-- should be ok +DROP VARIABLE IF EXISTS var1; + +-- the variable can use composite types +CREATE TABLE t1 (a int, b int); +CREATE VARIABLE var1 AS t1; + +-- should fail +DROP TABLE t1; + +-- should be ok +ALTER TABLE t1 ADD COLUMN c int; + +-- should fail +ALTER TABLE t1 ALTER COLUMN b TYPE numeric; + +DROP VARIABLE var1; +DROP TABLE t1; + +CREATE TYPE t1 AS (a int, b int); +CREATE VARIABLE var1 AS t1; + +-- should fail +DROP TYPE t1; + +-- should be ok +ALTER TYPE t1 ADD ATTRIBUTE c int; + +-- should fail +ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric; + +DROP VARIABLE var1; +DROP TYPE t1; + +SET log_statement TO default; + +CREATE DOMAIN testvar_domain AS int; +CREATE TYPE testvar_type AS (a testvar_domain); + +CREATE VARIABLE var1 AS testvar_domain; + +-- should fail +ALTER DOMAIN testvar_domain ADD CHECK(value <> 100); + +DROP VARIABLE var1; + +CREATE VARIABLE var1 AS testvar_type; + +-- should fail +ALTER DOMAIN testvar_domain ADD CHECK(value <> 100); + +DROP VARIABLE var1; + +-- should be ok +ALTER DOMAIN testvar_domain ADD CHECK(value <> 100); + +DROP TYPE testvar_type; +DROP TYPE testvar_domain; + +-- check event trigger support +CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped() +RETURNS event_trigger +AS $$ +DECLARE r record; +BEGIN + FOR r IN SELECT * from pg_event_trigger_dropped_objects() + LOOP + CONTINUE WHEN NOT r.normal AND NOT r.original; + + RAISE NOTICE + 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%', + r.original, r.normal, r.is_temporary, r.object_type, + r.object_identity, r.address_names, r.address_args; + END LOOP; +END; +$$ LANGUAGE plpgsql; + +CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop + WHEN TAG IN ('DROP VARIABLE') + EXECUTE PROCEDURE svar_event_trigger_report_dropped(); + +CREATE VARIABLE var1 AS int; +DROP VARIABLE var1; + +DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped; + +-- check comment on variable +CREATE VARIABLE var1 AS int; +COMMENT ON VARIABLE var1 IS 'some variable comment'; +SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1'; + +DROP VARIABLE var1; + +-- check the object address of all session variables +CREATE SCHEMA vartest1; +CREATE SCHEMA vartest2; +CREATE VARIABLE vartest1.svartest_var1 AS int; +CREATE VARIABLE vartest2.svartest_var1 AS int; + +SELECT + e.varname, + pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr, + b.type, b.object_names, b.object_args, + pg_identify_object(a.classid, a.objid, a.objsubid) as ident +FROM pg_variable as e, + LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b, + LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a +WHERE e.varname LIKE 'svartest_var%'; + +DROP SCHEMA vartest1 CASCADE; +DROP SCHEMA vartest2 CASCADE; + +-- check access rights and supported ALTER +CREATE SCHEMA svartest; +GRANT ALL ON SCHEMA svartest TO regress_variable_owner; + +CREATE VARIABLE svartest.var1 AS int; + +CREATE ROLE regress_variable_reader; + +GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader; +REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader; + +ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner; +ALTER VARIABLE svartest.var1 RENAME TO varxx; +ALTER VARIABLE svartest.varxx SET SCHEMA public; + +DROP VARIABLE public.varxx; + +ALTER DEFAULT PRIVILEGES + FOR ROLE regress_variable_owner + IN SCHEMA svartest + GRANT SELECT ON VARIABLES TO regress_variable_reader; + +-- creating variable with default privileges +SET ROLE TO regress_variable_owner; +CREATE VARIABLE svartest.var1 AS int; +SET ROLE TO DEFAULT; + +-- should be ok. since ALTER DEFAULT PRIVILEGES +-- allow regress_variable_reader to have SELECT priviledge +SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t + +DROP VARIABLE svartest.var1; +DROP SCHEMA svartest; +DROP ROLE regress_variable_reader; + +-- +-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY +-- +CREATE ROLE regress_variable_r1; +CREATE ROLE regress_variable_r2; + +SET ROLE TO regress_variable_owner; +CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner + +GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION; +SET ROLE TO regress_variable_r1; +GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION; +SET ROLE TO DEFAULT; + +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t + +REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE; + +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f + +SET ROLE TO regress_variable_owner; +GRANT SELECT ON VARIABLE var1 TO regress_variable_r2; + +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t + +REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner; + +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f +SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f +SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t +SET ROLE TO DEFAULT; + +DROP VARIABLE var1; +-- +-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY +-- + +-- +-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA +-- +CREATE SCHEMA svartest; +GRANT ALL ON SCHEMA svartest TO regress_variable_owner; +SET ROLE TO regress_variable_owner; + +CREATE VARIABLE svartest.var1 AS int; +CREATE VARIABLE svartest.var2 AS int; + +GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1; + +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t + +REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1; + +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f +SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f + +SET ROLE TO DEFAULT; +DROP VARIABLE svartest.var1; +DROP VARIABLE svartest.var2; +DROP SCHEMA svartest; +-- +-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA +-- + +-- +-- function has_session_variable_privilege have various kind of signature. +-- the following are extensive test for it. +-- +SET ROLE TO regress_variable_owner; + +CREATE VARIABLE public.var1 AS int; + +SET search_path TO public; + +GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1; +GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2; + +SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); +SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL; + +SET ROLE TO regress_variable_r1; + +SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f +SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t + +SELECT has_session_variable_privilege('var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f + +SELECT oid AS varid + FROM pg_variable + WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset + +SELECT has_session_variable_privilege('var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f + +SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f +SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t + +SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t +SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f + +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t + +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t +SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t +-- +-- end of function has_session_variable_privilege tests. +-- + +SET ROLE TO DEFAULT; +SET search_path TO DEFAULT; + +DROP VARIABLE public.var1; + +DROP ROLE regress_variable_r1; +DROP ROLE regress_variable_r2; + +DROP ROLE regress_variable_owner; diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index e5879e00dffe..517386fb8646 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -561,6 +561,7 @@ CreateRoleStmt CreateSchemaStmt CreateSchemaStmtContext CreateSeqStmt +CreateSessionVarStmt CreateStatsStmt CreateStmt CreateStmtContext @@ -906,6 +907,7 @@ FormData_pg_ts_parser FormData_pg_ts_template FormData_pg_type FormData_pg_user_mapping +FormData_pg_variable FormExtraData_pg_attribute Form_pg_aggregate Form_pg_am @@ -965,6 +967,7 @@ Form_pg_ts_parser Form_pg_ts_template Form_pg_type Form_pg_user_mapping +Form_pg_variable FormatNode FreeBlockNumberArray FreeListData @@ -3187,6 +3190,7 @@ VarString VarStringSortSupport Variable VariableAssignHook +VariableInfo VariableSetKind VariableSetStmt VariableShowStmt From 2597c9c65b4caf544665b4d19a8da3d01e91ce30 Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Thu, 6 Jul 2023 08:29:21 +0200 Subject: [PATCH 2/8] Storage for session variables and SQL interface Session variables are stored in session memory in a dedicated hash table. They are set by the LET command and read by the SELECT command. The access rights should be checked. The identifiers of session variables should always be shadowed by possible column identifiers: we don't want to break an application by creating some badly named session variable. The limits of this patch (solved by other patches): - session variables block parallel execution - session variables blocks simple expression evaluation (in plpgsql) - SQL functions with session variables are not inlined - CALL statement is not supported (usage of direct access to express executor) - EXECUTE statement is not supported (usage of direct access to express executor) - memory used by dropped session variables is not released Implementations of EXPLAIN LET and PREPARE LET statements are in separate patches (for better readability) --- doc/src/sgml/catalogs.sgml | 13 + doc/src/sgml/ddl.sgml | 61 + doc/src/sgml/func.sgml | 4 +- doc/src/sgml/glossary.sgml | 5 +- doc/src/sgml/parallel.sgml | 6 + doc/src/sgml/plpgsql.sgml | 14 + doc/src/sgml/ref/allfiles.sgml | 1 + doc/src/sgml/ref/alter_variable.sgml | 1 + doc/src/sgml/ref/create_variable.sgml | 5 +- doc/src/sgml/ref/drop_variable.sgml | 1 + doc/src/sgml/ref/let.sgml | 96 ++ doc/src/sgml/reference.sgml | 1 + src/backend/catalog/dependency.c | 5 + src/backend/catalog/namespace.c | 289 ++++ src/backend/catalog/pg_variable.c | 2 + src/backend/commands/Makefile | 1 + src/backend/commands/meson.build | 1 + src/backend/commands/prepare.c | 10 + src/backend/commands/session_variable.c | 529 +++++++ src/backend/executor/Makefile | 1 + src/backend/executor/execExpr.c | 32 + src/backend/executor/execMain.c | 66 + src/backend/executor/meson.build | 1 + src/backend/executor/svariableReceiver.c | 172 +++ src/backend/nodes/nodeFuncs.c | 10 + src/backend/optimizer/plan/planner.c | 36 + src/backend/optimizer/plan/setrefs.c | 156 ++- src/backend/optimizer/prep/prepjointree.c | 3 + src/backend/optimizer/util/clauses.c | 33 +- src/backend/parser/analyze.c | 272 +++- src/backend/parser/gram.y | 39 +- src/backend/parser/parse_agg.c | 9 + src/backend/parser/parse_expr.c | 223 ++- src/backend/parser/parse_func.c | 2 + src/backend/parser/parse_merge.c | 1 + src/backend/tcop/dest.c | 7 + src/backend/tcop/utility.c | 16 + src/backend/utils/adt/ruleutils.c | 46 + src/backend/utils/cache/plancache.c | 41 +- src/backend/utils/fmgr/fmgr.c | 10 +- src/bin/psql/tab-complete.in.c | 12 +- src/include/catalog/namespace.h | 1 + src/include/catalog/pg_variable.h | 9 + src/include/commands/session_variable.h | 30 + src/include/executor/svariableReceiver.h | 22 + src/include/nodes/execnodes.h | 14 + src/include/nodes/parsenodes.h | 17 + src/include/nodes/pathnodes.h | 14 + src/include/nodes/plannodes.h | 9 + src/include/nodes/primnodes.h | 14 + src/include/optimizer/planmain.h | 2 + src/include/parser/kwlist.h | 1 + src/include/parser/parse_node.h | 3 + src/include/tcop/cmdtaglist.h | 1 + src/include/tcop/dest.h | 1 + src/pl/plpgsql/src/pl_exec.c | 3 +- .../regress/expected/session_variables.out | 1232 +++++++++++++++++ src/test/regress/sql/session_variables.sql | 883 ++++++++++++ src/tools/pgindent/typedefs.list | 5 + 59 files changed, 4467 insertions(+), 27 deletions(-) create mode 100644 doc/src/sgml/ref/let.sgml create mode 100644 src/backend/commands/session_variable.c create mode 100644 src/backend/executor/svariableReceiver.c create mode 100644 src/include/commands/session_variable.h create mode 100644 src/include/executor/svariableReceiver.h diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index fc5623617926..0041e61dddd6 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -9831,6 +9831,19 @@ SCRAM-SHA-256$<iteration count>:&l + + + varcreate_lsn pg_lsn + + + LSN of the transaction where the variable was created. + varcreate_lsn and + oid together form the all-time unique + identifier (oid alone is not enough, since + object identifiers can get reused). + + + varname name diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index 66fa267faccb..b3fc62056e99 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -5385,6 +5385,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01'; The session variable holds value in session memory. This value is private to each session and is released when the session ends. + + + The value of a session variable is set with the SQL statement + LET. The value of a session variable can be retrieved + with the SQL statement SELECT. + +CREATE VARIABLE var1 AS date; +LET var1 = current_date; +SELECT var1; + + + or + + +CREATE VARIABLE public.current_user_id AS integer; +GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC; +LET current_user_id = (SELECT id FROM users WHERE usename = session_user); +SELECT current_user_id; + + + + + The value of a session variable is local to the current session. Retrieving + a variable's value returns a NULL, unless its value has + been set to something else in the current session using the + LET command. Session variables are not transactional: + any changes made to the value of a session variable in a transaction won't + be undone if the transaction is rolled back (just like variables in + procedural languages). Session variables themselves are persistent, but + their values are neither persistent nor shared (like the content of + temporary tables). + + + + Inside a query or an expression, a session variable can be + shadowed by a column with the same name. Similarly, the + name of a function or procedure argument or a PL/pgSQL variable (see + ) can shadow a session variable + in the routine's body. Such collisions of identifiers can be resolved + by using qualified identifiers: Session variables can be qualified with + the schema name, columns can use table aliases, routine variables can use + block labels, and routine arguments can use the routine name. + +CREATE VARIABLE name AS text; +LET name = 'John'; + +CREATE TABLE foo(name text); +INSERT INTO foo VALUES('Alice'); + +-- variable name is shadowed +SELECT name FROM foo; + + + which returns: + + + name +------- + Alice + + diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index e23dfa45bf93..f39ba251b17c 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -25860,8 +25860,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute'); 't' for TABLESPACE, 'F' for FOREIGN DATA WRAPPER, 'S' for FOREIGN SERVER, - or - 'T' for TYPE or DOMAIN. + 'T' for TYPE or DOMAIN or + 'V' for SESSION VARIABLE. diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml index 83b13f98f28e..2d13dcea4eff 100644 --- a/doc/src/sgml/glossary.sgml +++ b/doc/src/sgml/glossary.sgml @@ -1714,8 +1714,9 @@ A persistent database object that holds a value in session memory. This value is private to each session and is released when the session ends. - Read or write access to session variables is controlled by privileges, - similar to other database objects. + The default value of the session variable is null. Read or write access + to session variables is controlled by privileges, similar to other database + objects. For more information, see . diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml index 1ce9abf86f52..683dede6adce 100644 --- a/doc/src/sgml/parallel.sgml +++ b/doc/src/sgml/parallel.sgml @@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%'; Plan nodes that reference a correlated SubPlan. + + + + Plan nodes that use a session variable. + + diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml index e937491e6b89..1e4c43b8b614 100644 --- a/doc/src/sgml/plpgsql.sgml +++ b/doc/src/sgml/plpgsql.sgml @@ -6036,6 +6036,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE; + + + <command>Packages and package variables</command> + + + The PL/pgSQL language has no packages, and + therefore no package variables or package constants. + You can consider translating an Oracle package into a schema in + PostgreSQL. Package functions and procedures + would then become functions and procedures in that schema, and package + variables could be translated to session variables in that schema. + (see ). + + diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml index 2f67de3e21b6..cc3bd5ab5403 100644 --- a/doc/src/sgml/ref/allfiles.sgml +++ b/doc/src/sgml/ref/allfiles.sgml @@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory. + diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml index 96d2586423e4..221a699469b6 100644 --- a/doc/src/sgml/ref/alter_variable.sgml +++ b/doc/src/sgml/ref/alter_variable.sgml @@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private; + diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml index 6e988f2e4729..cd9ff63975a8 100644 --- a/doc/src/sgml/ref/create_variable.sgml +++ b/doc/src/sgml/ref/create_variable.sgml @@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] nameExamples - Create an date session variable var1: + Create a session variable var1 of data type date: CREATE VARIABLE var1 AS date; +LET var1 = current_date; +SELECT var1; @@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date; + diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml index 5bdb3560f0b0..67988b5fcd82 100644 --- a/doc/src/sgml/ref/drop_variable.sgml +++ b/doc/src/sgml/ref/drop_variable.sgml @@ -111,6 +111,7 @@ DROP VARIABLE var1; + diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml new file mode 100644 index 000000000000..00f9bea91fe3 --- /dev/null +++ b/doc/src/sgml/ref/let.sgml @@ -0,0 +1,96 @@ + + + + + LET + + + + session variable + changing + + + + LET + 7 + SQL - Language Statements + + + + LET + change a session variable's value + + + + +LET session_variable = sql_expression + + + + + Description + + + The LET command assigns a value to the specified session + variable. + + + + + + Parameters + + + + session_variable + + + The name of the session variable. + + + + + + sql_expression + + + An arbitrary SQL expression. The result must be of a data type that can + be cast to the type of the session variable in an assignment. + + + + + + + + + Examples + +CREATE VARIABLE myvar AS integer; +LET myvar = 10; +LET myvar = (SELECT sum(val) FROM tab); + + + + + Compatibility + + + The LET is a PostgreSQL + extension. + + + + + See Also + + + + + + + + diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml index 25578f3946cd..13e4adc5df3e 100644 --- a/doc/src/sgml/reference.sgml +++ b/doc/src/sgml/reference.sgml @@ -186,6 +186,7 @@ &grant; &importForeignSchema; &insert; + &let; &listen; &load; &lock; diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c index 9e0f648b74fd..90c9e8bb2541 100644 --- a/src/backend/catalog/dependency.c +++ b/src/backend/catalog/dependency.c @@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node, { Param *param = (Param *) node; + /* a variable parameter depends on the session variable */ + if (param->paramkind == PARAM_VARIABLE) + add_object_address(VariableRelationId, param->paramvarid, 0, + context->addrs); + /* A parameter must depend on the parameter's datatype */ add_object_address(TypeRelationId, param->paramtype, 0, context->addrs); diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c index 4307cad15c79..beafee2a3415 100644 --- a/src/backend/catalog/namespace.c +++ b/src/backend/catalog/namespace.c @@ -3497,6 +3497,295 @@ NamesFromList(List *names) return result; } +/* ----- + * IdentifyVariable - try to find a variable from a list of identifiers + * + * Returns the OID of the variable found, or InvalidOid. + * + * "names" is a list of up to four identifiers; possible meanings are: + * - variable (searched on the search_path) + * - schema.variable + * - variable.attribute (searched on the search_path) + * - schema.variable.attribute + * - database.schema.variable + * - database.schema.variable.attribute + * + * If there is more than one way to identify a variable, "not_unique" will be + * set to true. + * + * Unless "noerror" is true, an error is raised if there are more than four + * identifiers in the list, or if the named database is not the current one. + * This is useful if we want to identify a shadowed variable. + * + * If an attribute is identified, it is stored in "attrname", otherwise the + * parameter is set to NULL. + * + * The identified session variable will be locked with an AccessShareLock. + * ----- + */ +Oid +IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror) +{ + Oid varid = InvalidOid; + Oid old_varid = InvalidOid; + uint64 inval_count; + bool retry = false; + + /* + * DDL operations can change the results of a name lookup. Since all such + * operations will generate invalidation messages, we keep track of + * whether any such messages show up while we're performing the operation, + * and retry until either (1) no more invalidation messages show up or (2) + * the answer doesn't change. + */ + for (;;) + { + Node *field1 = NULL; + Node *field2 = NULL; + Node *field3 = NULL; + Node *field4 = NULL; + char *a = NULL; + char *b = NULL; + char *c = NULL; + char *d = NULL; + Oid varoid_without_attr = InvalidOid; + Oid varoid_with_attr = InvalidOid; + + *not_unique = false; + *attrname = NULL; + varid = InvalidOid; + + inval_count = SharedInvalidMessageCounter; + + switch (list_length(names)) + { + case 1: + field1 = linitial(names); + + Assert(IsA(field1, String)); + + varid = LookupVariable(NULL, strVal(field1), true); + break; + + case 2: + field1 = linitial(names); + field2 = lsecond(names); + + Assert(IsA(field1, String)); + a = strVal(field1); + + if (IsA(field2, String)) + { + /* when both fields are of string type */ + b = strVal(field2); + + /* + * a.b can mean "schema"."variable" or + * "variable"."attribute". Check both variants, and + * returns InvalidOid with not_unique flag, when both + * interpretations are possible. + */ + varoid_without_attr = LookupVariable(a, b, true); + varoid_with_attr = LookupVariable(NULL, a, true); + } + else + { + /* the last field of list can be star too */ + Assert(IsA(field2, A_Star)); + + /* + * The syntax ident.* is used only by relation aliases, + * and then this identifier cannot be a reference to + * session variable. + */ + return InvalidOid; + } + + if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr)) + { + *not_unique = true; + varid = varoid_without_attr; + } + else if (OidIsValid(varoid_without_attr)) + { + varid = varoid_without_attr; + } + else if (OidIsValid(varoid_with_attr)) + { + *attrname = b; + varid = varoid_with_attr; + } + break; + + case 3: + { + bool field1_is_catalog = false; + + field1 = linitial(names); + field2 = lsecond(names); + field3 = lthird(names); + + Assert(IsA(field1, String)); + Assert(IsA(field2, String)); + + a = strVal(field1); + b = strVal(field2); + + if (IsA(field3, String)) + { + c = strVal(field3); + + /* + * a.b.c can mean catalog.schema.variable or + * schema.variable.attribute. + * + * Check both variants, and set not_unique flag, when + * both interpretations are possible. + * + * When third node is star, only possible + * interpretation is schema.variable.*, but this + * pattern is not supported now. + */ + varoid_with_attr = LookupVariable(a, b, true); + + /* + * check pattern catalog.schema.variable only when + * there is possibility to success. + */ + if (strcmp(a, get_database_name(MyDatabaseId)) == 0) + { + field1_is_catalog = true; + varoid_without_attr = LookupVariable(b, c, true); + } + } + else + { + Assert(IsA(field3, A_Star)); + return InvalidOid; + } + + if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr)) + { + *not_unique = true; + varid = varoid_without_attr; + } + else if (OidIsValid(varoid_without_attr)) + { + varid = varoid_without_attr; + } + else if (OidIsValid(varoid_with_attr)) + { + *attrname = c; + varid = varoid_with_attr; + } + + /* + * When we didn't find variable, we can (when it is + * allowed) raise cross-database reference error. + */ + if (!OidIsValid(varid) && !noerror && !field1_is_catalog) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: %s", + NameListToString(names)))); + } + break; + + case 4: + { + field1 = linitial(names); + field2 = lsecond(names); + field3 = lthird(names); + field4 = lfourth(names); + + Assert(IsA(field1, String)); + Assert(IsA(field2, String)); + Assert(IsA(field3, String)); + + a = strVal(field1); + b = strVal(field2); + c = strVal(field3); + + /* + * In this case, "a" is used as catalog name - check it. + */ + if (strcmp(a, get_database_name(MyDatabaseId)) != 0) + { + if (!noerror) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cross-database references are not implemented: %s", + NameListToString(names)))); + } + + if (IsA(field4, String)) + { + d = strVal(field4); + } + else + { + Assert(IsA(field4, A_Star)); + return InvalidOid; + } + + *attrname = d; + varid = LookupVariable(b, c, true); + } + break; + + default: + if (!noerror) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("improper qualified name (too many dotted names): %s", + NameListToString(names)))); + return InvalidOid; + } + + /* + * If, upon retry, we get back the same OID we did last time, then the + * invalidation messages we processed did not change the final answer. + * So we're done. + * + * If we got a different OID, we've locked the variable that used to + * have this name rather than the one that does now. So release the + * lock. + */ + if (retry) + { + if (old_varid == varid) + break; + + if (OidIsValid(old_varid)) + UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock); + } + + /* + * Lock the variable. This will also accept any pending invalidation + * messages. If we got back InvalidOid, indicating not found, then + * there's nothing to lock, but we accept invalidation messages + * anyway, to flush any negative catcache entries that may be + * lingering. + */ + if (!OidIsValid(varid)) + AcceptInvalidationMessages(); + else + LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock); + + /* + * If no invalidation message were processed, we're done! + */ + if (inval_count == SharedInvalidMessageCounter) + break; + + retry = true; + old_varid = varid; + varid = InvalidOid; + } + + return varid; +} + /* * DeconstructQualifiedName * Given a possibly-qualified name expressed as a list of String nodes, diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c index 29d967a2d5bf..bb445e9434b9 100644 --- a/src/backend/catalog/pg_variable.c +++ b/src/backend/catalog/pg_variable.c @@ -26,6 +26,7 @@ #include "parser/parse_type.h" #include "utils/builtins.h" #include "utils/lsyscache.h" +#include "utils/pg_lsn.h" #include "utils/syscache.h" static ObjectAddress create_variable(const char *varName, @@ -101,6 +102,7 @@ create_variable(const char *varName, varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid); values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid); + values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr()); values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname); values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace); values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType); diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile index cb2fbdc7c601..aee40e7bd598 100644 --- a/src/backend/commands/Makefile +++ b/src/backend/commands/Makefile @@ -53,6 +53,7 @@ OBJS = \ schemacmds.o \ seclabel.o \ sequence.o \ + session_variable.o \ statscmds.o \ subscriptioncmds.o \ tablecmds.o \ diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build index dd4cde41d32c..101c8d75dd1e 100644 --- a/src/backend/commands/meson.build +++ b/src/backend/commands/meson.build @@ -41,6 +41,7 @@ backend_sources += files( 'schemacmds.c', 'seclabel.c', 'sequence.c', + 'session_variable.c', 'statscmds.c', 'subscriptioncmds.c', 'tablecmds.c', diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c index bf7d2b2309fc..56b3d8cb91d1 100644 --- a/src/backend/commands/prepare.c +++ b/src/backend/commands/prepare.c @@ -342,6 +342,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params, i++; } + /* + * The arguments of EXECUTE are evaluated by a direct expression + * executor call. This mode doesn't support session variables yet. + * It will be enabled later. + */ + if (pstate->p_hasSessionVariables) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("session variable cannot be used as an argument"))); + /* Prepare the expressions for execution */ exprstates = ExecPrepareExprList(params, estate); diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c new file mode 100644 index 000000000000..d2891a1dcb72 --- /dev/null +++ b/src/backend/commands/session_variable.c @@ -0,0 +1,529 @@ +/*------------------------------------------------------------------------- + * + * session_variable.c + * session variable creation/manipulation commands + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/commands/session_variable.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "catalog/pg_variable.h" +#include "commands/session_variable.h" +#include "executor/svariableReceiver.h" +#include "funcapi.h" +#include "miscadmin.h" +#include "rewrite/rewriteHandler.h" +#include "storage/lmgr.h" +#include "storage/proc.h" +#include "tcop/tcopprot.h" +#include "utils/builtins.h" +#include "utils/datum.h" +#include "utils/inval.h" +#include "utils/lsyscache.h" +#include "utils/snapmgr.h" +#include "utils/syscache.h" + +/* + * The values of session variables are stored in the backend's private memory + * in the dedicated memory context SVariableMemoryContext in binary format. + * They are stored in the "sessionvars" hash table, whose key is the OID of the + * variable. However, the OID is not good enough to identify a session + * variable: concurrent sessions could drop the session variable and create a + * new one, which could be assigned the same OID. To ensure that the values + * stored in memory and the catalog definition match, we also keep track of + * the "create_lsn". Before any access to the variable values, we need to + * check if the LSN stored in memory matches the LSN in the catalog. If there + * is a mismatch between the LSNs, or if the OID is not present in pg_variable + * at all, the value stored in memory is released. + */ +typedef struct SVariableData +{ + Oid varid; /* pg_variable OID of the variable (hash key) */ + XLogRecPtr create_lsn; + + bool isnull; + Datum value; + + Oid typid; + int16 typlen; + bool typbyval; + + bool is_domain; + + /* + * domain_check_extra holds cached domain metadata. This "extra" is + * usually stored in fn_mcxt. We do not have access to that memory context + * for session variables, but we can use TopTransactionContext instead. + * A fresh value is forced when we detect we are in a different transaction + * (the local transaction ID differs from domain_check_extra_lxid). + */ + void *domain_check_extra; + LocalTransactionId domain_check_extra_lxid; + + /* + * Stored value and type description can be outdated when we receive a + * sinval message. We then have to check if the stored data are still + * trustworthy. + */ + bool is_valid; + + uint32 hashvalue; /* used for pairing sinval message */ +} SVariableData; + +typedef SVariableData *SVariable; + +static HTAB *sessionvars = NULL; /* hash table for session variables */ + +static MemoryContext SVariableMemoryContext = NULL; + +/* + * Callback function for session variable invalidation. + */ +static void +pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue) +{ + HASH_SEQ_STATUS status; + SVariable svar; + + elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue); + + Assert(sessionvars); + + /* + * If the hashvalue is not specified, we have to recheck all currently + * used session variables. Since we can't tell the exact session variable + * from its hashvalue, we have to iterate over all items in the hash bucket. + */ + hash_seq_init(&status, sessionvars); + + while ((svar = (SVariable) hash_seq_search(&status)) != NULL) + { + if (hashvalue == 0 || svar->hashvalue == hashvalue) + { + svar->is_valid = false; + } + } +} + +/* + * Release stored value, free memory + */ +static void +free_session_variable_value(SVariable svar) +{ + /* clean the current value */ + if (!svar->isnull) + { + if (!svar->typbyval) + pfree(DatumGetPointer(svar->value)); + + svar->isnull = true; + } + + svar->value = (Datum) 0; +} + +/* + * Returns true when the entry in pg_variable is consistent with the given + * session variable. + */ +static bool +is_session_variable_valid(SVariable svar) +{ + HeapTuple tp; + bool result = false; + + Assert(OidIsValid(svar->varid)); + + tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid)); + + if (HeapTupleIsValid(tp)) + { + /* + * The OID alone is not enough as an unique identifier, because OID + * values get recycled, and a new session variable could have got + * the same OID. We do a second check against the 64-bit LSN when + * the variable was created. + */ + if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn) + result = true; + + ReleaseSysCache(tp); + } + + return result; +} + +/* + * Initialize attributes cached in "svar" + */ +static void +setup_session_variable(SVariable svar, Oid varid) +{ + HeapTuple tup; + Form_pg_variable varform; + + Assert(OidIsValid(varid)); + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for session variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + svar->varid = varid; + svar->create_lsn = varform->varcreate_lsn; + + svar->typid = varform->vartype; + + get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval); + + svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN); + svar->domain_check_extra = NULL; + svar->domain_check_extra_lxid = InvalidLocalTransactionId; + + svar->isnull = true; + svar->value = (Datum) 0; + + svar->is_valid = true; + + svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID, + ObjectIdGetDatum(varid)); + + ReleaseSysCache(tup); +} + +/* + * Assign a new value to the session variable. It is copied to + * SVariableMemoryContext if necessary. + * + * If any error happens, the existing value won't be modified. + */ +static void +set_session_variable(SVariable svar, Datum value, bool isnull) +{ + Datum newval; + SVariableData locsvar, + *_svar; + + Assert(svar); + Assert(!isnull || value == (Datum) 0); + + /* + * Use typbyval, typbylen from session variable only when they are + * trustworthy (the invalidation message was not accepted for this + * variable). If the variable might be invalid, force setup. + * + * Do not overwrite the passed session variable until we can be certain + * that no error can be thrown. + */ + if (!svar->is_valid) + { + setup_session_variable(&locsvar, svar->varid); + _svar = &locsvar; + } + else + _svar = svar; + + if (!isnull) + { + MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext); + + newval = datumCopy(value, _svar->typbyval, _svar->typlen); + + MemoryContextSwitchTo(oldcxt); + } + else + newval = value; + + free_session_variable_value(svar); + + elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value", + get_namespace_name(get_session_variable_namespace(svar->varid)), + get_session_variable_name(svar->varid), + svar->varid); + + /* no more error expected, so we can overwrite the old variable now */ + if (svar != _svar) + memcpy(svar, _svar, sizeof(SVariableData)); + + svar->value = newval; + svar->isnull = isnull; +} + +/* + * Create the hash table for storing session variables. + */ +static void +create_sessionvars_hashtables(void) +{ + HASHCTL vars_ctl; + + Assert(!sessionvars); + + if (!SVariableMemoryContext) + { + /* read sinval messages */ + CacheRegisterSyscacheCallback(VARIABLEOID, + pg_variable_cache_callback, + (Datum) 0); + + /* we need our own long-lived memory context */ + SVariableMemoryContext = + AllocSetContextCreate(TopMemoryContext, + "session variables", + ALLOCSET_START_SMALL_SIZES); + } + + memset(&vars_ctl, 0, sizeof(vars_ctl)); + vars_ctl.keysize = sizeof(Oid); + vars_ctl.entrysize = sizeof(SVariableData); + vars_ctl.hcxt = SVariableMemoryContext; + + sessionvars = hash_create("Session variables", 64, &vars_ctl, + HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); +} + +/* + * Search a session variable in the hash table given its OID. If it + * doesn't exist, then insert it there. + * + * The caller is responsible for doing permission checks. + * + * As a side effect, this function acquires a AccessShareLock on the + * session variable until the end of the transaction. + */ +static SVariable +get_session_variable(Oid varid) +{ + SVariable svar; + bool found; + + /* protect the used session variable against DROP */ + LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock); + + if (!sessionvars) + create_sessionvars_hashtables(); + + svar = (SVariable) hash_search(sessionvars, &varid, + HASH_ENTER, &found); + + if (found) + { + if (!svar->is_valid) + { + /* + * If there was an invalidation message, the variable might still be + * valid, but we have to check with the system catalog. + */ + if (is_session_variable_valid(svar)) + svar->is_valid = true; + else + /* if the value cannot be validated, we have to discard it */ + free_session_variable_value(svar); + } + } + else + svar->is_valid = false; + + /* + * Force setup for not yet initialized variables or variables that cannot + * be validated. + */ + if (!svar->is_valid) + { + setup_session_variable(svar, varid); + + elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)", + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid), + varid); + } + + /* ensure the returned data is still of the correct domain */ + if (svar->is_domain) + { + /* + * Store "extra" for domain_check() in TopTransactionContext. When we + * are in a new transaction, domain_check_extra cache is not valid any + * more. + */ + if (svar->domain_check_extra_lxid != MyProc->vxid.lxid) + svar->domain_check_extra = NULL; + + domain_check(svar->value, svar->isnull, + svar->typid, &svar->domain_check_extra, + TopTransactionContext); + + svar->domain_check_extra_lxid = MyProc->vxid.lxid; + } + + return svar; +} + +/* + * Store the given value in a session variable in the cache. + * + * The caller is responsible for doing permission checks. + * + * As a side effect, this function acquires a AccessShareLock on the session + * variable until the end of the transaction. + */ +void +SetSessionVariable(Oid varid, Datum value, bool isNull) +{ + SVariable svar; + bool found; + + /* protect used session variable against DROP */ + LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock); + + if (!sessionvars) + create_sessionvars_hashtables(); + + svar = (SVariable) hash_search(sessionvars, &varid, + HASH_ENTER, &found); + + if (!found) + { + setup_session_variable(svar, varid); + + elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)", + get_namespace_name(get_session_variable_namespace(svar->varid)), + get_session_variable_name(svar->varid), + varid); + } + + /* if this fails, it won't change the stored value */ + set_session_variable(svar, value, isNull); +} + +/* + * Returns a copy of the value stored in a variable. + */ +static inline Datum +copy_session_variable_value(SVariable svar, bool *isNull) +{ + Datum value; + + /* force copy of non NULL value */ + if (!svar->isnull) + { + value = datumCopy(svar->value, svar->typbyval, svar->typlen); + *isNull = false; + } + else + { + value = (Datum) 0; + *isNull = true; + } + + return value; +} + +/* + * Returns a copy of the value of the session variable (in the current memory + * context). The caller is responsible for permission checks. + */ +Datum +GetSessionVariable(Oid varid, bool *isNull) +{ + SVariable svar; + + svar = get_session_variable(varid); + + /* + * Although "svar" is freshly validated in this point, svar->is_valid can + * be false, if an invalidation message was processed during the domain check. + * But the variable and all its dependencies are locked now, so we don't need + * to repeat the validation. + */ + return copy_session_variable_value(svar, isNull); +} + +/* + * Assign the result of the evaluated expression to the session variable + */ +void +ExecuteLetStmt(ParseState *pstate, + LetStmt *stmt, + ParamListInfo params, + QueryEnvironment *queryEnv, + QueryCompletion *qc) +{ + Query *query = castNode(Query, stmt->query); + List *rewritten; + DestReceiver *dest; + AclResult aclresult; + PlannedStmt *plan; + QueryDesc *queryDesc; + Oid varid = query->resultVariable; + + Assert(OidIsValid(varid)); + + /* do we have permission to write to the session variable? */ + aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE); + if (aclresult != ACLCHECK_OK) + aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid)); + + /* create a dest receiver for LET */ + dest = CreateVariableDestReceiver(varid); + + /* run the query rewriter */ + query = copyObject(query); + + rewritten = QueryRewrite(query); + + Assert(list_length(rewritten) == 1); + + query = linitial_node(Query, rewritten); + Assert(query->commandType == CMD_SELECT); + + /* plan the query */ + plan = pg_plan_query(query, pstate->p_sourcetext, + CURSOR_OPT_PARALLEL_OK, params); + + /* + * Use a snapshot with an updated command ID to ensure this query sees the + * results of any previously executed queries. (This could only matter if + * the planner executed an allegedly-stable function that changed the + * database contents, but let's do it anyway to be parallel to the EXPLAIN + * code path.) + */ + PushCopiedSnapshot(GetActiveSnapshot()); + UpdateActiveSnapshotCommandId(); + + /* create a QueryDesc, redirecting output to our tuple receiver */ + queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext, + GetActiveSnapshot(), InvalidSnapshot, + dest, params, queryEnv, 0); + + /* call ExecutorStart to prepare the plan for execution */ + ExecutorStart(queryDesc, 0); + + /* + * Run the plan to completion. The result should be only one row. To + * check if there are too many result rows, we try to fetch two. + */ + ExecutorRun(queryDesc, ForwardScanDirection, 2L); + + /* save the rowcount if we're given a QueryCompletion to fill */ + if (qc) + SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed); + + /* and clean up */ + ExecutorFinish(queryDesc); + ExecutorEnd(queryDesc); + + FreeQueryDesc(queryDesc); + + PopActiveSnapshot(); +} diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile index 11118d0ce025..71248a34f264 100644 --- a/src/backend/executor/Makefile +++ b/src/backend/executor/Makefile @@ -76,6 +76,7 @@ OBJS = \ nodeWindowAgg.o \ nodeWorktablescan.o \ spi.o \ + svariableReceiver.o \ tqueue.o \ tstoreReceiver.o diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index f1569879b529..e4e9de335b53 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state, scratch.d.param.paramtype = param->paramtype; ExprEvalPushStep(state, &scratch); break; + + case PARAM_VARIABLE: + { + int es_num_session_variables = 0; + SessionVariableValue *es_session_variables = NULL; + SessionVariableValue *var; + + if (state->parent && state->parent->state) + { + es_session_variables = state->parent->state->es_session_variables; + es_num_session_variables = state->parent->state->es_num_session_variables; + } + + Assert(es_session_variables); + + /* parameter sanity checks */ + if (param->paramid >= es_num_session_variables) + elog(ERROR, "paramid of PARAM_VARIABLE param is out of range"); + + var = &es_session_variables[param->paramid]; + + /* + * In this case, pass the value like a + * constant. + */ + scratch.opcode = EEOP_CONST; + scratch.d.constval.value = var->value; + scratch.d.constval.isnull = var->isnull; + ExprEvalPushStep(state, &scratch); + } + break; + case PARAM_EXTERN: /* diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c index 7230f968101a..a9d31b085fd3 100644 --- a/src/backend/executor/execMain.c +++ b/src/backend/executor/execMain.c @@ -43,7 +43,9 @@ #include "access/xact.h" #include "catalog/namespace.h" #include "catalog/partition.h" +#include "catalog/pg_variable.h" #include "commands/matview.h" +#include "commands/session_variable.h" #include "commands/trigger.h" #include "executor/executor.h" #include "executor/execPartition.h" @@ -206,6 +208,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags) Assert(queryDesc->sourceText != NULL); estate->es_sourceText = queryDesc->sourceText; + /* + * The executor doesn't work with session variables directly. Values of + * related session variables are copied to a dedicated array, and this array + * is passed to the executor. This array is stable "snapshot" of values of + * used session variables. There are three benefits of this strategy: + * + * - consistency with external parameters and plpgsql variables, + * + * - session variables can be parallel safe, + * + * - we don't need make fresh copy for any read of session variable + * (this is necessary because the internally the session variable can + * be changed inside query execution time, and then a reference to + * previously returned value can be corrupted). + */ + if (queryDesc->plannedstmt->sessionVariables) + { + int nSessionVariables; + int i = 0; + + /* + * In this case, the query uses session variables, but we have to + * prepare the array with passed values (of used session variables) + * first. + */ + Assert(!IsParallelWorker()); + nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables); + + /* create the array used for passing values of used session variables */ + estate->es_session_variables = (SessionVariableValue *) + palloc(nSessionVariables * sizeof(SessionVariableValue)); + + /* fill the array */ + foreach_oid(varid, queryDesc->plannedstmt->sessionVariables) + { + /* + * Permission check should be executed on all explicitly used + * variables in the query. For implicitly used variable + * (like base node of assignment indirect) we cannot do permission + * check, because we need read the value (and user can have + * only UPDATE variable). In this case the permission check + * is executed in write time. + */ + if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid) + { + AclResult aclresult; + + aclresult = object_aclcheck(VariableRelationId, varid, + GetUserId(), ACL_SELECT); + if (aclresult != ACLCHECK_OK) + aclcheck_error(aclresult, OBJECT_VARIABLE, + get_session_variable_name(varid)); + } + + estate->es_session_variables[i].value = + GetSessionVariable(varid, + &estate->es_session_variables[i].isnull); + + i++; + } + + estate->es_num_session_variables = nSessionVariables; + } + /* * Fill in the query environment, if any, from queryDesc. */ diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build index 2cea41f87711..491092fcc4c7 100644 --- a/src/backend/executor/meson.build +++ b/src/backend/executor/meson.build @@ -64,6 +64,7 @@ backend_sources += files( 'nodeWindowAgg.c', 'nodeWorktablescan.c', 'spi.c', + 'svariableReceiver.c', 'tqueue.c', 'tstoreReceiver.c', ) diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c new file mode 100644 index 000000000000..c6163fb36f63 --- /dev/null +++ b/src/backend/executor/svariableReceiver.c @@ -0,0 +1,172 @@ +/*------------------------------------------------------------------------- + * + * svariableReceiver.c + * An implementation of DestReceiver that stores the result value in + * a session variable. + * + * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/backend/executor/svariableReceiver.c + * + *------------------------------------------------------------------------- + */ + +#include "postgres.h" +#include "miscadmin.h" + +#include "access/detoast.h" +#include "catalog/pg_variable.h" +#include "commands/session_variable.h" +#include "executor/svariableReceiver.h" +#include "storage/lock.h" +#include "utils/builtins.h" +#include "utils/lsyscache.h" +#include "utils/syscache.h" + +/* + * This DestReceiver is used by the LET command for storing the result to a + * session variable. The result has to have only one tuple with only one + * non-deleted attribute. The row counter (field "rows") is incremented + * after receiving a row, and an error is raised when there are no rows or + * there are more than one received rows. A received tuple cannot to have + * deleted attributes. The value is detoasted before storing it in the + * session variable. + */ +typedef struct +{ + DestReceiver pub; + Oid varid; + bool need_detoast; /* do we need to detoast the attribute? */ + int rows; /* row counter */ +} SVariableState; + +/* + * Prepare to receive tuples from executor. + */ +static void +svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo) +{ + SVariableState *myState = (SVariableState *) self; + LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY; + Form_pg_attribute attr; + Oid typid PG_USED_FOR_ASSERTS_ONLY; + Oid collid PG_USED_FOR_ASSERTS_ONLY; + int32 typmod PG_USED_FOR_ASSERTS_ONLY; + + Assert(myState->pub.mydest == DestVariable); + Assert(OidIsValid(myState->varid)); + Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid)); + Assert(typeinfo->natts == 1); + +#ifdef USE_ASSERT_CHECKING + + SET_LOCKTAG_OBJECT(locktag, + MyDatabaseId, + VariableRelationId, + myState->varid, + 0); + + Assert(LockHeldByMe(&locktag, AccessShareLock, false)); + +#endif + + attr = TupleDescAttr(typeinfo, 0); + + Assert(!attr->attisdropped); + +#ifdef USE_ASSERT_CHECKING + + get_session_variable_type_typmod_collid(myState->varid, + &typid, + &typmod, + &collid); + + Assert(attr->atttypid == typid); + Assert(attr->atttypmod < 0 || attr->atttypmod == typmod); + +#endif + + myState->need_detoast = attr->attlen == -1; + myState->rows = 0; +} + +/* + * Receive a tuple from the executor and store it in the session variable. + */ +static bool +svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self) +{ + SVariableState *myState = (SVariableState *) self; + Datum value; + bool isnull; + bool freeval = false; + + /* make sure the tuple is fully deconstructed */ + slot_getallattrs(slot); + + value = slot->tts_values[0]; + isnull = slot->tts_isnull[0]; + + if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value))) + { + value = PointerGetDatum(detoast_external_attr((struct varlena *) + DatumGetPointer(value))); + freeval = true; + } + + myState->rows += 1; + + if (myState->rows > 1) + ereport(ERROR, + (errcode(ERRCODE_TOO_MANY_ROWS), + errmsg("expression returned more than one row"))); + + SetSessionVariable(myState->varid, value, isnull); + + if (freeval) + pfree(DatumGetPointer(value)); + + return true; +} + +/* + * Clean up at end of the executor run + */ +static void +svariableShutdownReceiver(DestReceiver *self) +{ + if (((SVariableState *) self)->rows == 0) + ereport(ERROR, + (errcode(ERRCODE_NO_DATA_FOUND), + errmsg("expression returned no rows"))); +} + +/* + * Destroy the receiver when we are done with it + */ +static void +svariableDestroyReceiver(DestReceiver *self) +{ + pfree(self); +} + +/* + * Initially create a DestReceiver object. + */ +DestReceiver * +CreateVariableDestReceiver(Oid varid) +{ + SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState)); + + self->pub.receiveSlot = svariableReceiveSlot; + self->pub.rStartup = svariableStartupReceiver; + self->pub.rShutdown = svariableShutdownReceiver; + self->pub.rDestroy = svariableDestroyReceiver; + self->pub.mydest = DestVariable; + + self->varid = varid; + + return (DestReceiver *) self; +} diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c index 7bc823507f1b..d8fc3d9fa69d 100644 --- a/src/backend/nodes/nodeFuncs.c +++ b/src/backend/nodes/nodeFuncs.c @@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node, return true; } break; + case T_LetStmt: + { + LetStmt *stmt = (LetStmt *) node; + + if (WALK(stmt->target)) + return true; + if (WALK(stmt->query)) + return true; + } + break; case T_PLAssignStmt: { PLAssignStmt *stmt = (PLAssignStmt *) node; diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index beafac8c0b04..ed171e39b33e 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -338,6 +338,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions, glob->lastPlanNodeId = 0; glob->transientPlan = false; glob->dependsOnRole = false; + glob->sessionVariables = NIL; + + /* + * The (session) result variable should be stored to global, because + * it is not set in subquery. When this variable is used other than + * in base node of assignment indirection, we need to check the access + * rights (and then we need to detect this situation). The variable used + * like base node cannot be different than target (result) variable. + * Because we know the result variable before planner invocation, we + * can simply search of usage just this variable, and we don't need to + * to wait until the end of planning when we know basenodeSessionVarid. + */ + glob->resultVariable = parse->resultVariable; + glob->basenodeSessionVarid = InvalidOid; + glob->basenodeSessionVarSelectCheck = false; /* * Assess whether it's feasible to use parallel mode for this query. We @@ -576,6 +591,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions, result->paramExecTypes = glob->paramExecTypes; /* utilityStmt should be null, but we might as well copy it */ result->utilityStmt = parse->utilityStmt; + + result->sessionVariables = glob->sessionVariables; + + /* + * The session variable used (and only used) like base node + * for assignemnt indirection should be excluded from permission + * check. + */ + if (OidIsValid(glob->basenodeSessionVarid) && + (!glob->basenodeSessionVarSelectCheck)) + result->exclSelectPermCheckVarid = glob->basenodeSessionVarid; + else + result->exclSelectPermCheckVarid = InvalidOid; + result->stmt_location = parse->stmt_location; result->stmt_len = parse->stmt_len; @@ -754,6 +783,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, */ pull_up_subqueries(root); + /* + * Check if some subquery uses a session variable. The flag + * hasSessionVariables should be true if the query or some subquery uses a + * session variable. + */ + pull_up_has_session_variables(root); + /* * If this is a simple UNION ALL query, flatten it into an appendrel. We * do this now because it requires applying pull_up_subqueries to the leaf diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 150e9f060ee0..d071bd0c5596 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root, static List *set_windowagg_runcondition_references(PlannerInfo *root, List *runcondition, Plan *plan); +static bool pull_up_has_session_variables_walker(Node *node, + PlannerInfo *root); +static void record_plan_variable_dependency(PlannerInfo *root, Oid varid); /***************************************************************************** @@ -1318,6 +1321,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset) return plan; } +/* + * Search usage of session variables in subqueries + */ +void +pull_up_has_session_variables(PlannerInfo *root) +{ + Query *query = root->parse; + + if (query->hasSessionVariables) + { + root->hasSessionVariables = true; + } + else + { + (void) query_tree_walker(query, + pull_up_has_session_variables_walker, + (void *) root, 0); + } +} + +static bool +pull_up_has_session_variables_walker(Node *node, PlannerInfo *root) +{ + if (node == NULL) + return false; + if (IsA(node, Query)) + { + Query *query = (Query *) node; + + if (query->hasSessionVariables) + { + root->hasSessionVariables = true; + return false; + } + + /* recurse into subselects */ + return query_tree_walker((Query *) node, + pull_up_has_session_variables_walker, + (void *) root, 0); + } + return expression_tree_walker(node, pull_up_has_session_variables_walker, + (void *) root); +} + /* * set_indexonlyscan_references * Do set_plan_references processing on an IndexOnlyScan @@ -2018,8 +2065,9 @@ copyVar(Var *var) * This is code that is common to all variants of expression-fixing. * We must look up operator opcode info for OpExpr and related nodes, * add OIDs from regclass Const nodes into root->glob->relationOids, and - * add PlanInvalItems for user-defined functions into root->glob->invalItems. - * We also fill in column index lists for GROUPING() expressions. + * add PlanInvalItems for user-defined functions and session variables into + * root->glob->invalItems. We also fill in column index lists for GROUPING() + * expressions. * * We assume it's okay to update opcode info in-place. So this could possibly * scribble on the planner's input data structures, but it's OK. @@ -2109,6 +2157,13 @@ fix_expr_common(PlannerInfo *root, Node *node) g->cols = cols; } } + else if (IsA(node, Param)) + { + Param *p = (Param *) node; + + if (p->paramkind == PARAM_VARIABLE) + record_plan_variable_dependency(root, p->paramvarid); + } } /* @@ -2118,6 +2173,10 @@ fix_expr_common(PlannerInfo *root, Node *node) * If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from * root->multiexpr_params; otherwise no change is needed. * Just for paranoia's sake, we make a copy of the node in either case. + * + * If it's a PARAM_VARIABLE, then we collect used session variables in + * the list root->glob->sessionVariable. Also, assign the parameter's + * "paramid" to the parameter's position in that list. */ static Node * fix_param_node(PlannerInfo *root, Param *p) @@ -2136,6 +2195,62 @@ fix_param_node(PlannerInfo *root, Param *p) elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid); return copyObject(list_nth(params, colno - 1)); } + + if (p->paramkind == PARAM_VARIABLE) + { + int n = 0; + bool found = false; + + /* we will modify object */ + p = (Param *) copyObject(p); + + /* + * Now, we can actualize list of session variables, and we can + * complete paramid parameter. + */ + foreach_oid(varid, root->glob->sessionVariables) + { + if (varid == p->paramvarid) + { + p->paramid = n; + found = true; + break; + } + n += 1; + } + + if (!found) + { + root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables, + p->paramvarid); + p->paramid = n; + } + + /* + * We do SELECT permission check of all variables used by + * the query excluding the variable that is used only as base node + * of assignment indirection. The variable id assigned to this param + * should be same like resultVariable id, and this param should be + * used only once in query. When the variable is referenced by any + * other param, we should to do SELECT permission check for this variable + * too. + */ + if (p->parambasenode) + { + Assert(!OidIsValid(root->glob->basenodeSessionVarid)); + Assert(root->glob->resultVariable == p->paramvarid); + + root->glob->basenodeSessionVarid = p->paramvarid; + } + else + { + if (p->paramvarid == root->glob->resultVariable) + root->glob->basenodeSessionVarSelectCheck = true; + } + + return (Node *) p; + } + return (Node *) copyObject(p); } @@ -2197,7 +2312,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan, * replacing Aggref nodes that should be replaced by initplan output Params, * choosing the best implementation for AlternativeSubPlans, * looking up operator opcode info for OpExpr and related nodes, - * and adding OIDs from regclass Const nodes into root->glob->relationOids. + * adding OIDs from regclass Const nodes into root->glob->relationOids, + * assigning paramvarid to PARAM_VARIABLE params, and collecting the + * OIDs of session variables in the root->glob->sessionVariables list + * (paramvarid is the position of the session variable in this list). * * 'node': the expression to be modified * 'rtoffset': how much to increment varnos by @@ -2219,7 +2337,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec) root->multiexpr_params != NIL || root->glob->lastPHId != 0 || root->minmax_aggs != NIL || - root->hasAlternativeSubPlans) + root->hasAlternativeSubPlans || + root->hasSessionVariables) { return fix_scan_expr_mutator(node, &context); } @@ -3612,6 +3731,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid) } } +/* + * Record dependency on a session variable. The variable can be used as a + * session variable in an expression list, or as the target of a LET statement. + */ +static void +record_plan_variable_dependency(PlannerInfo *root, Oid varid) +{ + PlanInvalItem *inval_item = makeNode(PlanInvalItem); + + /* paramid is still session variable id */ + inval_item->cacheId = VARIABLEOID; + inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID, + ObjectIdGetDatum(varid)); + + /* append this variable to global, register dependency */ + root->glob->invalItems = lappend(root->glob->invalItems, + inval_item); +} + /* * extract_query_dependencies * Given a rewritten, but not yet planned, query or queries @@ -3697,9 +3835,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context) } /* - * Ignore other utility statements, except those (such as EXPLAIN) - * that contain a parsed-but-not-planned query. For those, we - * just need to transfer our attention to the contained query. + * Ignore other utility statements, except those (such as EXPLAIN + * or LET) that contain a parsed-but-not-planned query. For those, + * we just need to transfer our attention to the contained query. */ query = UtilityContainsQuery(query->utilityStmt); if (query == NULL) @@ -3722,6 +3860,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context) lappend_oid(context->glob->relationOids, rte->relid); } + /* record dependency on the target variable of a LET command */ + if (OidIsValid(query->resultVariable)) + record_plan_variable_dependency(context, query->resultVariable); + /* And recurse into the query's subexpressions */ return query_tree_walker(query, extract_query_dependencies_walker, context, 0); diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 87dc6f56b576..1ebc808a5e67 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -1585,6 +1585,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte, /* If subquery had any RLS conditions, now main query does too */ parse->hasRowSecurity |= subquery->hasRowSecurity; + /* if the subquery had session variables, the main query does too */ + parse->hasSessionVariables |= subquery->hasSessionVariables; + /* * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or * hasTargetSRFs, so no work needed on those flags diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 26a3e0500866..23cafc73c3b8 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -24,6 +24,7 @@ #include "catalog/pg_operator.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" +#include "commands/session_variable.h" #include "executor/executor.h" #include "executor/functions.h" #include "funcapi.h" @@ -936,6 +937,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context) if (param->paramkind == PARAM_EXTERN) return false; + /* we don't support passing session variables to workers */ + if (param->paramkind == PARAM_VARIABLE) + { + if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context)) + return true; + } + if (param->paramkind != PARAM_EXEC || !list_member_int(context->safe_param_ids, param->paramid)) { @@ -2391,6 +2399,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context) * value of the Param. * 2. Fold stable, as well as immutable, functions to constants. * 3. Reduce PlaceHolderVar nodes to their contained expressions. + * 4. Current value of session variable can be used for estimation too. *-------------------- */ Node * @@ -2517,6 +2526,27 @@ eval_const_expressions_mutator(Node *node, } } } + else if (param->paramkind == PARAM_VARIABLE && + context->estimate) + { + int16 typLen; + bool typByVal; + Datum pval; + bool isnull; + + get_typlenbyval(param->paramtype, + &typLen, &typByVal); + + pval = GetSessionVariable(param->paramvarid, &isnull); + + return (Node *) makeConst(param->paramtype, + param->paramtypmod, + param->paramcollid, + (int) typLen, + pval, + isnull, + typByVal); + } /* * Not replaceable, so just copy the Param (no need to @@ -4722,7 +4752,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid, querytree->limitOffset || querytree->limitCount || querytree->setOperations || - list_length(querytree->targetList) != 1) + (list_length(querytree->targetList) != 1) || + querytree->hasSessionVariables) goto fail; /* If the function result is composite, resolve it */ diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 1f4d6adda524..3df219f98d2d 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -25,9 +25,12 @@ #include "postgres.h" #include "access/sysattr.h" +#include "catalog/namespace.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/defrem.h" +#include "commands/session_variable.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" @@ -51,6 +54,7 @@ #include "utils/backend_status.h" #include "utils/builtins.h" #include "utils/guc.h" +#include "utils/lsyscache.h" #include "utils/rel.h" #include "utils/syscache.h" @@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt); static Query *transformCallStmt(ParseState *pstate, CallStmt *stmt); +static Query *transformLetStmt(ParseState *pstate, + LetStmt *stmt); static void transformLockingClause(ParseState *pstate, Query *qry, LockingClause *lc, bool pushedDown); #ifdef DEBUG_NODE_TESTS_ENABLED @@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree) case T_UpdateStmt: case T_DeleteStmt: case T_MergeStmt: + case T_LetStmt: (void) test_raw_expression_coverage(parseTree, NULL); break; default: @@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree) (CallStmt *) parseTree); break; + case T_LetStmt: + result = transformLetStmt(pstate, + (LetStmt *) parseTree); + break; + default: /* @@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree) case T_SelectStmt: case T_ReturnStmt: case T_PLAssignStmt: + case T_LetStmt: result = true; break; @@ -692,6 +705,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt) qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasTargetSRFs = pstate->p_hasTargetSRFs; qry->hasAggs = pstate->p_hasAggs; + qry->hasSessionVariables = pstate->p_hasSessionVariables; assign_query_collations(pstate, qry); @@ -1117,6 +1131,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt) qry->hasTargetSRFs = pstate->p_hasTargetSRFs; qry->hasSubLinks = pstate->p_hasSubLinks; + qry->hasSessionVariables = pstate->p_hasSessionVariables; assign_query_collations(pstate, qry); @@ -1582,6 +1597,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt) qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasTargetSRFs = pstate->p_hasTargetSRFs; qry->hasAggs = pstate->p_hasAggs; + qry->hasSessionVariables = pstate->p_hasSessionVariables; foreach(l, stmt->lockingClause) { @@ -1808,12 +1824,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt) qry->jointree = makeFromExpr(pstate->p_joinlist, NULL); qry->hasSubLinks = pstate->p_hasSubLinks; + qry->hasSessionVariables = pstate->p_hasSessionVariables; assign_query_collations(pstate, qry); return qry; } +/* + * transformLetStmt - + * transform an Let Statement + */ +static Query * +transformLetStmt(ParseState *pstate, LetStmt *stmt) +{ + Query *query; + Query *result; + List *exprList = NIL; + List *exprListCoer = NIL; + ListCell *lc; + ListCell *indirection_head = NULL; + Query *selectQuery; + Oid varid; + char *attrname = NULL; + bool not_unique; + bool is_rowtype; + Oid typid; + int32 typmod; + Oid collid; + List *names = NULL; + int indirection_start; + int i = 0; + + /* there can't be any outer WITH to worry about */ + Assert(pstate->p_ctenamespace == NIL); + + names = NamesFromList(stmt->target); + + /* locks the variable with an AccessShareLock */ + varid = IdentifyVariable(names, &attrname, ¬_unique, false); + if (not_unique) + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_PARAMETER), + errmsg("target \"%s\" of LET command is ambiguous", + NameListToString(names)), + parser_errposition(pstate, stmt->location))); + + if (!OidIsValid(varid)) + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("session variable \"%s\" doesn't exist", + NameListToString(names)), + parser_errposition(pstate, stmt->location))); + + /* + * Calculate start of possible position of an indirection in list, and + * when it is inside the list, store pointer on first node of indirection. + */ + indirection_start = list_length(names) - (attrname ? 1 : 0); + if (list_length(stmt->target) > indirection_start) + indirection_head = list_nth_cell(stmt->target, indirection_start); + + get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid); + + is_rowtype = type_is_rowtype(typid); + + if (attrname && !is_rowtype) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type", + attrname, + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid), + format_type_be(typid)), + parser_errposition(pstate, stmt->location))); + + pstate->p_expr_kind = EXPR_KIND_LET_TARGET; + + /* we need to postpone conversion of "unknown" to text */ + pstate->p_resolve_unknowns = false; + + selectQuery = transformStmt(pstate, stmt->query); + + /* the grammar should have produced a SELECT */ + Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT); + + /* + * Generate an expression list for the LET that selects all the non-resjunk + * columns from the subquery. + */ + exprList = NIL; + foreach_node(TargetEntry, tle, selectQuery->targetList) + { + if (tle->resjunk) + continue; + + exprList = lappend(exprList, tle->expr); + } + + /* don't allow multicolumn result */ + if (list_length(exprList) != 1) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg_plural("assignment expression returned %d column", + "assignment expression returned %d columns", + list_length(exprList), + list_length(exprList)), + parser_errposition(pstate, + exprLocation((Node *) exprList)))); + + exprListCoer = NIL; + + foreach(lc, exprList) + { + Expr *expr = (Expr *) lfirst(lc); + Expr *coerced_expr; + Oid exprtypid; + + /* now we can read the type of the expression */ + exprtypid = exprType((Node *) expr); + + if (indirection_head) + { + bool targetIsArray; + char *targetName; + Param *param; + + targetName = get_session_variable_name(varid); + targetIsArray = OidIsValid(get_element_type(typid)); + + pstate->p_hasSessionVariables = true; + + param = makeNode(Param); + param->paramkind = PARAM_VARIABLE; + param->paramvarid = varid; + param->paramtype = typid; + param->paramtypmod = typmod; + + /* + * The parameter used as basenode has to have special + * mark, because requires special access when we do + * SELECT access check. + */ + param->parambasenode = true; + + coerced_expr = (Expr *) + transformAssignmentIndirection(pstate, + (Node *) param, + targetName, + targetIsArray, + typid, + typmod, + InvalidOid, + stmt->target, + indirection_head, + (Node *) expr, + COERCION_ASSIGNMENT, + stmt->location); + } + else + coerced_expr = (Expr *) + coerce_to_target_type(pstate, + (Node *) expr, + exprtypid, + typid, typmod, + COERCION_ASSIGNMENT, + COERCE_IMPLICIT_CAST, + stmt->location); + + if (coerced_expr == NULL) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s", + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid), + format_type_be(typid), + format_type_be(exprtypid)), + errhint("You will need to rewrite or cast the expression."), + parser_errposition(pstate, exprLocation((Node *) expr)))); + + exprListCoer = lappend(exprListCoer, coerced_expr); + } + + /* generate query's target list using the computed list of expressions */ + query = makeNode(Query); + query->commandType = CMD_SELECT; + + foreach(lc, exprListCoer) + { + Expr *expr = (Expr *) lfirst(lc); + TargetEntry *tle; + + tle = makeTargetEntry(expr, + i + 1, + FigureColname((Node *) expr), + false); + query->targetList = lappend(query->targetList, tle); + } + + /* done building the range table and jointree */ + query->rtable = pstate->p_rtable; + query->jointree = makeFromExpr(pstate->p_joinlist, NULL); + + query->hasTargetSRFs = pstate->p_hasTargetSRFs; + query->hasSubLinks = pstate->p_hasSubLinks; + query->hasSessionVariables = pstate->p_hasSessionVariables; + + /* this is top-level query */ + query->canSetTag = true; + + /* + * Save target session variable ID. It is used later for + * acquiring an AccessShareLock on target variable, setting + * plan dependency and finally for creating VariableDestReceiver. + */ + query->resultVariable = varid; + + assign_query_collations(pstate, query); + + /* + * The query is executed as utility command by nested executor call. + * Assigned queryId is required in this case. + */ + if (IsQueryIdEnabled()) + JumbleQuery(query); + + stmt->query = (Node *) query; + + /* represent the command as a utility Query */ + result = makeNode(Query); + result->commandType = CMD_UTILITY; + result->utilityStmt = (Node *) stmt; + + return result; +} + /* * transformSetOperationStmt - * transforms a set-operations tree @@ -2059,6 +2304,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt) qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasTargetSRFs = pstate->p_hasTargetSRFs; qry->hasAggs = pstate->p_hasAggs; + qry->hasSessionVariables = pstate->p_hasSessionVariables; foreach(l, lockingClause) { @@ -2534,6 +2780,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt) qry->hasWindowFuncs = pstate->p_hasWindowFuncs; qry->hasTargetSRFs = pstate->p_hasTargetSRFs; qry->hasAggs = pstate->p_hasAggs; + qry->hasSessionVariables = pstate->p_hasSessionVariables; assign_query_collations(pstate, qry); @@ -2601,6 +2848,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt) qry->hasTargetSRFs = pstate->p_hasTargetSRFs; qry->hasSubLinks = pstate->p_hasSubLinks; + qry->hasSessionVariables = pstate->p_hasSessionVariables; assign_query_collations(pstate, qry); @@ -2891,9 +3139,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt) /* * Transform the target reference. Typically we will get back a Param * node, but there's no reason to be too picky about its type. + * + * Session variables should not be used as target of a PL/pgSQL assign + * statement. So we should use a dedicated expression kind and disallow + * session variables there. The dedicated context allows to eliminate + * undesirable warnings about the possibility of a target PL/pgSQL variable + * shadowing a session variable. */ target = transformExpr(pstate, (Node *) cref, - EXPR_KIND_UPDATE_TARGET); + EXPR_KIND_ASSIGN_TARGET); targettype = exprType(target); targettypmod = exprTypmod(target); targetcollation = exprCollation(target); @@ -2935,6 +3189,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt) */ type_id = exprType((Node *) tle->expr); + /* + * For indirection processing and additional casts we can use expr_kind + * EXPR_KIND_UPDATE_TARGET. + */ pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET; if (indirection) @@ -3077,6 +3335,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt) (LockingClause *) lfirst(l), false); } + qry->hasSessionVariables = pstate->p_hasSessionVariables; + assign_query_collations(pstate, qry); /* this must be done after collations, for reliable comparison of exprs */ @@ -3350,6 +3610,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt) true, stmt->funccall->location); + /* + * The arguments of CALL statement are evaluated by a direct expression + * executor call. This path is unsupported yet, so block it. It will be + * enabled later. + */ + if (pstate->p_hasSessionVariables) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("session variable cannot be used as an argument"))); + assign_expr_collations(pstate, node); fexpr = castNode(FuncExpr, node); diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 71c71272958d..99fac3411da2 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); DropTransformStmt DropUserMappingStmt ExplainStmt FetchStmt GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt - ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt + LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt RuleActionStmt RuleActionStmtOrEmpty RuleStmt @@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); KEEP KEY KEYS LABEL LANGUAGE LARGE_P LAST_P LATERAL_P - LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL + LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD @@ -1089,6 +1089,7 @@ stmt: | ImportForeignSchemaStmt | IndexStmt | InsertStmt + | LetStmt | ListenStmt | RefreshMatViewStmt | LoadStmt @@ -12868,6 +12869,38 @@ opt_hold: /* EMPTY */ { $$ = 0; } | WITHOUT HOLD { $$ = 0; } ; +/***************************************************************************** + * + * QUERY: + * LET STATEMENT + * + *****************************************************************************/ +LetStmt: LET ColId opt_indirection '=' a_expr + { + LetStmt *n = makeNode(LetStmt); + SelectStmt *select; + ResTarget *res; + + n->target = lcons(makeString($2), + check_indirection($3, yyscanner)); + + select = makeNode(SelectStmt); + res = makeNode(ResTarget); + + /* create target list for implicit query */ + res->name = NULL; + res->indirection = NIL; + res->val = (Node *) $5; + res->location = @5; + + select->targetList = list_make1(res); + n->query = (Node *) select; + + n->location = @2; + $$ = (Node *) n; + } + ; + /***************************************************************************** * * QUERY: @@ -17939,6 +17972,7 @@ unreserved_keyword: | LARGE_P | LAST_P | LEAKPROOF + | LET | LEVEL | LISTEN | LOAD @@ -18553,6 +18587,7 @@ bare_label_keyword: | LEAKPROOF | LEAST | LEFT + | LET | LEVEL | LIKE | LISTEN diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index 0ac8966e30ff..de0a4a5653aa 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr) errkind = true; break; + case EXPR_KIND_ASSIGN_TARGET: + case EXPR_KIND_LET_TARGET: + errkind = true; + break; + /* * There is intentionally no default: case here, so that the * compiler will warn if we add a new ParseExprKind without @@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, case EXPR_KIND_CYCLE_MARK: errkind = true; break; + case EXPR_KIND_ASSIGN_TARGET: + case EXPR_KIND_LET_TARGET: + errkind = true; + break; /* * There is intentionally no default: case here, so that the diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 1f8e2d54673d..988d1c66f566 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -17,6 +17,7 @@ #include "catalog/pg_aggregate.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/dbcommands.h" #include "miscadmin.h" #include "nodes/makefuncs.h" @@ -33,11 +34,13 @@ #include "parser/parse_relation.h" #include "parser/parse_target.h" #include "parser/parse_type.h" +#include "storage/lmgr.h" #include "utils/builtins.h" #include "utils/date.h" #include "utils/fmgroids.h" #include "utils/lsyscache.h" #include "utils/timestamp.h" +#include "utils/typcache.h" #include "utils/xml.h" /* GUC parameters */ @@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree, int location); static Node *make_nulltest_from_distinct(ParseState *pstate, A_Expr *distincta, Node *arg); +static Node *makeParamSessionVariable(ParseState *pstate, + Oid varid, Oid typid, int32 typmod, Oid collid, + char *attrname, int location); /* @@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind) return result; } +/* + * Returns true if the given expression kind is valid for session variables. + * Session variables can be used everywhere where external parameters can be + * used. Session variables are not allowed in DDL commands or in constraints. + * + * An identifier can be parsed as a session variable only for expression kinds + * where session variables are allowed. This is the primary usage of this + * function. + * + * The second usage of this function is to decide whether a "column does not + * exist" or a "column or variable does not exist" error message should be + * printed. When we are in an expression where session variables cannot be + * used, we raise the first form of error message. + */ +static bool +expr_kind_allows_session_variables(ParseExprKind p_expr_kind) +{ + bool result = false; + + switch (p_expr_kind) + { + case EXPR_KIND_NONE: + Assert(false); /* can't happen */ + return false; + + /* session variables allowed */ + case EXPR_KIND_OTHER: + case EXPR_KIND_JOIN_ON: + case EXPR_KIND_FROM_SUBSELECT: + case EXPR_KIND_FROM_FUNCTION: + case EXPR_KIND_WHERE: + case EXPR_KIND_HAVING: + case EXPR_KIND_FILTER: + case EXPR_KIND_WINDOW_PARTITION: + case EXPR_KIND_WINDOW_ORDER: + case EXPR_KIND_WINDOW_FRAME_RANGE: + case EXPR_KIND_WINDOW_FRAME_ROWS: + case EXPR_KIND_WINDOW_FRAME_GROUPS: + case EXPR_KIND_SELECT_TARGET: + case EXPR_KIND_INSERT_TARGET: + case EXPR_KIND_UPDATE_SOURCE: + case EXPR_KIND_UPDATE_TARGET: + case EXPR_KIND_MERGE_WHEN: + case EXPR_KIND_MERGE_RETURNING: + case EXPR_KIND_GROUP_BY: + case EXPR_KIND_ORDER_BY: + case EXPR_KIND_DISTINCT_ON: + case EXPR_KIND_LIMIT: + case EXPR_KIND_OFFSET: + case EXPR_KIND_RETURNING: + case EXPR_KIND_VALUES: + case EXPR_KIND_VALUES_SINGLE: + case EXPR_KIND_ALTER_COL_TRANSFORM: + case EXPR_KIND_EXECUTE_PARAMETER: + case EXPR_KIND_POLICY: + case EXPR_KIND_CALL_ARGUMENT: + case EXPR_KIND_COPY_WHERE: + case EXPR_KIND_LET_TARGET: + result = true; + break; + + /* session variables not allowed */ + case EXPR_KIND_CHECK_CONSTRAINT: + case EXPR_KIND_DOMAIN_CHECK: + case EXPR_KIND_COLUMN_DEFAULT: + case EXPR_KIND_FUNCTION_DEFAULT: + case EXPR_KIND_INDEX_EXPRESSION: + case EXPR_KIND_INDEX_PREDICATE: + case EXPR_KIND_STATS_EXPRESSION: + case EXPR_KIND_TRIGGER_WHEN: + case EXPR_KIND_PARTITION_BOUND: + case EXPR_KIND_PARTITION_EXPRESSION: + case EXPR_KIND_GENERATED_COLUMN: + case EXPR_KIND_JOIN_USING: + case EXPR_KIND_CYCLE_MARK: + case EXPR_KIND_ASSIGN_TARGET: + result = false; + break; + } + + return result; +} + /* * Transform a ColumnRef. * @@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) case EXPR_KIND_COPY_WHERE: case EXPR_KIND_GENERATED_COLUMN: case EXPR_KIND_CYCLE_MARK: + case EXPR_KIND_ASSIGN_TARGET: + case EXPR_KIND_LET_TARGET: /* okay */ break; @@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) } /* - * Throw error if no translation found. + * There are contexts where session variables are not allowed. We don't + * need to identify session variables in such a context, but identifying + * them allows us to raise meaningful error messages like "you cannot use + * session variables here". */ + if (expr_kind_allows_session_variables(pstate->p_expr_kind)) + { + Oid varid = InvalidOid; + char *attrname = NULL; + bool not_unique; + + /* ----- + * Session variables are shadowed by columns, routine variables or + * routine arguments. We certainly don't want to use a session variable + * when it is exactly shadowed, but a RTE like this is conceivable: + * + * CREATE TYPE t AS (c int); + * CREATE VARIABLE foo AS t; + * CREATE TABLE foo(a int, b int); + * + * SELECT foo.a, foo.b, foo.c FROM foo; + * + * However, that is very confusing, so we disallow it. We don't try to + * identify a variable if we know that it would be shadowed. + * ----- + */ + if (!node && !(relname && crerr == CRERR_NO_COLUMN)) + { + /* takes an AccessShareLock on the session variable */ + varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false); + + if (OidIsValid(varid)) + { + Oid typid; + int32 typmod; + Oid collid; + + if (not_unique) + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_PARAMETER), + errmsg("session variable reference \"%s\" is ambiguous", + NameListToString(cref->fields)), + parser_errposition(pstate, cref->location))); + + get_session_variable_type_typmod_collid(varid, &typid, &typmod, + &collid); + + node = makeParamSessionVariable(pstate, + varid, typid, typmod, collid, + attrname, cref->location); + } + } + } + + /* throw an error if no translation was found */ if (node == NULL) { switch (crerr) @@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) return node; } +/* + * Generate param variable for reference to session variable + */ +static Node * +makeParamSessionVariable(ParseState *pstate, + Oid varid, Oid typid, int32 typmod, Oid collid, + char *attrname, int location) +{ + Param *param; + + param = makeNode(Param); + + param->paramkind = PARAM_VARIABLE; + param->paramvarid = varid; + param->paramtype = typid; + param->paramtypmod = typmod; + param->paramcollid = collid; + + pstate->p_hasSessionVariables = true; + + if (attrname != NULL) + { + TupleDesc tupdesc; + int i; + + tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true); + if (!tupdesc) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type", + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid), + format_type_be(typid)), + parser_errposition(pstate, location))); + + for (i = 0; i < tupdesc->natts; i++) + { + Form_pg_attribute att = TupleDescAttr(tupdesc, i); + + if (strcmp(attrname, NameStr(att->attname)) == 0 && + !att->attisdropped) + { + /* success, so generate a FieldSelect expression */ + FieldSelect *fselect = makeNode(FieldSelect); + + fselect->arg = (Expr *) param; + fselect->fieldnum = i + 1; + fselect->resulttype = att->atttypid; + fselect->resulttypmod = att->atttypmod; + /* save attribute's collation for parse_collate.c */ + fselect->resultcollid = att->attcollation; + + ReleaseTupleDesc(tupdesc); + return (Node *) fselect; + } + } + + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_COLUMN), + errmsg("could not identify column \"%s\" in variable \"%s.%s\"", + attrname, + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid)), + parser_errposition(pstate, location))); + } + + return (Node *) param; +} + static Node * transformParamRef(ParseState *pstate, ParamRef *pref) { @@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink) case EXPR_KIND_VALUES: case EXPR_KIND_VALUES_SINGLE: case EXPR_KIND_CYCLE_MARK: + case EXPR_KIND_LET_TARGET: /* okay */ break; case EXPR_KIND_CHECK_CONSTRAINT: @@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink) case EXPR_KIND_GENERATED_COLUMN: err = _("cannot use subquery in column generation expression"); break; + case EXPR_KIND_ASSIGN_TARGET: + err = _("cannot use subquery as target of assign statement"); + break; /* * There is intentionally no default: case here, so that the @@ -3215,6 +3432,10 @@ ParseExprKindName(ParseExprKind exprKind) return "GENERATED AS"; case EXPR_KIND_CYCLE_MARK: return "CYCLE"; + case EXPR_KIND_ASSIGN_TARGET: + return "ASSIGN"; + case EXPR_KIND_LET_TARGET: + return "LET"; /* * There is intentionally no default: case here, so that the diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c index 583bbbf232f0..dc25f6dcd0e2 100644 --- a/src/backend/parser/parse_func.c +++ b/src/backend/parser/parse_func.c @@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location) err = _("set-returning functions are not allowed in column generation expressions"); break; case EXPR_KIND_CYCLE_MARK: + case EXPR_KIND_ASSIGN_TARGET: + case EXPR_KIND_LET_TARGET: errkind = true; break; diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c index 51d7703eff7e..244efcddf329 100644 --- a/src/backend/parser/parse_merge.c +++ b/src/backend/parser/parse_merge.c @@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt) qry->hasTargetSRFs = false; qry->hasSubLinks = pstate->p_hasSubLinks; + qry->hasSessionVariables = pstate->p_hasSessionVariables; assign_query_collations(pstate, qry); diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c index b620766c9388..b2f764b657fc 100644 --- a/src/backend/tcop/dest.c +++ b/src/backend/tcop/dest.c @@ -38,6 +38,7 @@ #include "executor/functions.h" #include "executor/tqueue.h" #include "executor/tstoreReceiver.h" +#include "executor/svariableReceiver.h" #include "libpq/libpq.h" #include "libpq/pqformat.h" @@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest) case DestExplainSerialize: return CreateExplainSerializeDestReceiver(NULL); + + case DestVariable: + return CreateVariableDestReceiver(InvalidOid); } /* should never get here */ @@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o case DestTransientRel: case DestTupleQueue: case DestExplainSerialize: + case DestVariable: break; } } @@ -237,6 +242,7 @@ NullCommand(CommandDest dest) case DestTransientRel: case DestTupleQueue: case DestExplainSerialize: + case DestVariable: break; } } @@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest) case DestTransientRel: case DestTupleQueue: case DestExplainSerialize: + case DestVariable: break; } } diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 99a51877d349..7a508a3644fe 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -49,6 +49,7 @@ #include "commands/schemacmds.h" #include "commands/seclabel.h" #include "commands/sequence.h" +#include "commands/session_variable.h" #include "commands/subscriptioncmds.h" #include "commands/tablecmds.h" #include "commands/tablespace.h" @@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree) case T_CallStmt: case T_DoStmt: + case T_LetStmt: { /* * Commands inside the DO block or the called procedure might @@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt, break; } + case T_LetStmt: + ExecuteLetStmt(pstate, (LetStmt *) parsetree, params, + queryEnv, qc); + break; + default: /* All other statement types have event trigger support */ ProcessUtilitySlow(pstate, pstmt, queryString, @@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree) return UtilityContainsQuery(qry->utilityStmt); return qry; + case T_LetStmt: + qry = castNode(Query, ((LetStmt *) parsetree)->query); + return qry; + default: return NULL; } @@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree) tag = CMDTAG_SELECT; break; + case T_LetStmt: + tag = CMDTAG_LET; + break; + /* utility statements --- same whether raw or cooked */ case T_TransactionStmt: { @@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree) break; case T_PLAssignStmt: + case T_LetStmt: lev = LOGSTMT_ALL; break; diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 467b08198b83..f23f511cd56d 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -37,6 +37,7 @@ #include "catalog/pg_statistic_ext.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" +#include "catalog/pg_variable.h" #include "commands/defrem.h" #include "commands/tablespace.h" #include "common/keywords.h" @@ -534,6 +535,7 @@ static char *generate_function_name(Oid funcid, int nargs, static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2); static void add_cast_to(StringInfo buf, Oid typid); static char *generate_qualified_type_name(Oid typid); +static char *generate_session_variable_name(Oid varid); static text *string_to_text(char *str); static char *flatten_reloptions(Oid relid); static void get_reloptions(StringInfo buf, Datum reloptions); @@ -8729,6 +8731,14 @@ get_parameter(Param *param, deparse_context *context) return; } + /* translate paramvarid to session variable name */ + if (param->paramkind == PARAM_VARIABLE) + { + appendStringInfo(context->buf, "%s", + generate_session_variable_name(param->paramvarid)); + return; + } + /* * Alternatively, maybe it's a subplan output, which we print as a * reference to the subplan. (We could drill down into the subplan and @@ -13556,6 +13566,42 @@ generate_collation_name(Oid collid) return result; } +/* + * generate_session_variable_name + * Compute the name to display for a session variable specified by OID + * + * The result includes all necessary quoting and schema-prefixing. + */ +static char * +generate_session_variable_name(Oid varid) +{ + HeapTuple tup; + Form_pg_variable varform; + char *varname; + char *nspname; + char *result; + + tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid)); + + if (!HeapTupleIsValid(tup)) + elog(ERROR, "cache lookup failed for variable %u", varid); + + varform = (Form_pg_variable) GETSTRUCT(tup); + + varname = NameStr(varform->varname); + + if (!VariableIsVisible(varid)) + nspname = get_namespace_name_or_temp(varform->varnamespace); + else + nspname = NULL; + + result = quote_qualified_identifier(nspname, varname); + + ReleaseSysCache(tup); + + return result; +} + /* * Given a C string, produce a TEXT datum. * diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c index 9bcbc4c3e976..7c93b9a49b48 100644 --- a/src/backend/utils/cache/plancache.c +++ b/src/backend/utils/cache/plancache.c @@ -58,6 +58,7 @@ #include "access/transam.h" #include "catalog/namespace.h" +#include "catalog/pg_variable.h" #include "executor/executor.h" #include "miscadmin.h" #include "nodes/nodeFuncs.h" @@ -154,6 +155,7 @@ InitPlanCache(void) CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0); CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0); CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0); + CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0); } /* @@ -2165,17 +2167,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire) /* * Recurse into sublink subqueries, too. But we already did the ones in - * the rtable and cteList. + * the rtable and cteList. We need to force a recursive call for session + * variables too, to find and lock variables used in the query (see + * ScanQueryWalker). */ - if (parsetree->hasSubLinks) + if (parsetree->hasSubLinks || + parsetree->hasSessionVariables) { query_tree_walker(parsetree, ScanQueryWalker, &acquire, QTW_IGNORE_RC_SUBQUERIES); } + + /* process session variables */ + if (OidIsValid(parsetree->resultVariable)) + { + if (acquire) + LockDatabaseObject(VariableRelationId, parsetree->resultVariable, + 0, AccessShareLock); + else + UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable, + 0, AccessShareLock); + } } /* - * Walker to find sublink subqueries for ScanQueryForLocks + * Walker to find sublink subqueries or referenced session variables + * for ScanQueryForLocks */ static bool ScanQueryWalker(Node *node, bool *acquire) @@ -2190,6 +2207,20 @@ ScanQueryWalker(Node *node, bool *acquire) ScanQueryForLocks(castNode(Query, sub->subselect), *acquire); /* Fall through to process lefthand args of SubLink */ } + else if (IsA(node, Param)) + { + Param *p = (Param *) node; + + if (p->paramkind == PARAM_VARIABLE) + { + if (acquire) + LockDatabaseObject(VariableRelationId, p->paramvarid, + 0, AccessShareLock); + else + UnlockDatabaseObject(VariableRelationId, p->paramvarid, + 0, AccessShareLock); + } + } /* * Do NOT recurse into Query nodes, because ScanQueryForLocks already @@ -2320,7 +2351,9 @@ PlanCacheRelCallback(Datum arg, Oid relid) /* * PlanCacheObjectCallback - * Syscache inval callback function for PROCOID and TYPEOID caches + * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID, + * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and + * VARIABLEOID caches. * * Invalidate all plans mentioning the object with the specified hash value, * or all plans mentioning any member of this cache if hashvalue == 0. diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c index 782291d99983..093622fbdc4b 100644 --- a/src/backend/utils/fmgr/fmgr.c +++ b/src/backend/utils/fmgr/fmgr.c @@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum) */ if (IsA(arg, Const)) return true; - if (IsA(arg, Param) && - ((Param *) arg)->paramkind == PARAM_EXTERN) - return true; + if (IsA(arg, Param)) + { + Param *p = (Param *) arg; + + if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE) + return true; + } return false; } diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c index 94bd86c01b93..78b130c04b0a 100644 --- a/src/bin/psql/tab-complete.in.c +++ b/src/bin/psql/tab-complete.in.c @@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = { "ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER", "COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE", "DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN", - "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK", - "MERGE INTO", "MOVE", "NOTIFY", "PREPARE", + "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET", + "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE", "REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE", "RESET", "REVOKE", "ROLLBACK", "SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START", @@ -4695,6 +4695,14 @@ match_previous_words(int pattern_id, else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES")) COMPLETE_WITH("("); +/* LET */ + /* If prev. word is LET suggest a list of variables */ + else if (Matches("LET")) + COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables); + /* Complete LET with "=" */ + else if (TailMatches("LET", MatchAny)) + COMPLETE_WITH("="); + /* LOCK */ /* Complete LOCK [TABLE] [ONLY] with a list of tables */ else if (Matches("LOCK")) diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h index bdac0c13beca..5060b8c94907 100644 --- a/src/include/catalog/namespace.h +++ b/src/include/catalog/namespace.h @@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path); extern List *NamesFromList(List *names); extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok); extern Oid LookupVariableFromNameList(List *names, bool missing_ok); +extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror); extern Oid get_collation_oid(List *collname, bool missing_ok); extern Oid get_conversion_oid(List *conname, bool missing_ok); diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h index 3d3c6eb24b58..5b45be5afaf6 100644 --- a/src/include/catalog/pg_variable.h +++ b/src/include/catalog/pg_variable.h @@ -18,6 +18,7 @@ #ifndef PG_VARIABLE_H #define PG_VARIABLE_H +#include "access/xlogdefs.h" #include "catalog/genbki.h" #include "catalog/objectaddress.h" #include "catalog/pg_variable_d.h" @@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId) /* OID of entry in pg_type for variable's type */ Oid vartype BKI_LOOKUP(pg_type); + /* + * Used for identity check [oid, create_lsn]. + * + * This column of the 8-byte XlogRecPtr type should be at an address that + * is divisible by 8, but before any column of type NameData. + */ + XLogRecPtr varcreate_lsn; + /* variable name */ NameData varname; diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h new file mode 100644 index 000000000000..2391b9ad4438 --- /dev/null +++ b/src/include/commands/session_variable.h @@ -0,0 +1,30 @@ +/*------------------------------------------------------------------------- + * + * sessionvariable.h + * prototypes for sessionvariable.c. + * + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/commands/session_variable.h + * + *------------------------------------------------------------------------- + */ + +#ifndef SESSIONVARIABLE_H +#define SESSIONVARIABLE_H + +#include "nodes/params.h" +#include "nodes/parsenodes.h" +#include "parser/parse_node.h" +#include "tcop/cmdtag.h" +#include "utils/queryenvironment.h" + +extern void SetSessionVariable(Oid varid, Datum value, bool isNull); +extern Datum GetSessionVariable(Oid varid, bool *isNull); + +extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params, + QueryEnvironment *queryEnv, QueryCompletion *qc); + +#endif diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h new file mode 100644 index 000000000000..db44d8b94c6e --- /dev/null +++ b/src/include/executor/svariableReceiver.h @@ -0,0 +1,22 @@ +/*------------------------------------------------------------------------- + * + * svariableReceiver.h + * prototypes for svariableReceiver.c + * + * + * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/executor/svariableReceiver.h + * + *------------------------------------------------------------------------- + */ + +#ifndef SVARIABLE_RECEIVER_H +#define SVARIABLE_RECEIVER_H + +#include "tcop/dest.h" + +extern DestReceiver *CreateVariableDestReceiver(Oid varid); + +#endif /* SVARIABLE_RECEIVER_H */ diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index 5b6cadb5a6c1..79c0732aad5e 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -642,6 +642,16 @@ typedef struct AsyncRequest * tuples) */ } AsyncRequest; +/* ---------------- + * SessionVariableValue + * ---------------- + */ +typedef struct SessionVariableValue +{ + bool isnull; + Datum value; +} SessionVariableValue; + /* ---------------- * EState information * @@ -702,6 +712,10 @@ typedef struct EState ParamListInfo es_param_list_info; /* values of external params */ ParamExecData *es_param_exec_vals; /* values of internal params */ + /* Session variables info: */ + int es_num_session_variables; /* number of used variables */ + SessionVariableValue *es_session_variables; /* array of copies of values */ + QueryEnvironment *es_queryEnv; /* query environment */ /* Other working state: */ diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index ae4b6a3862cf..8f874a08d295 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -142,6 +142,9 @@ typedef struct Query */ int resultRelation pg_node_attr(query_jumble_ignore); + /* target variable of LET statement */ + Oid resultVariable; + /* has aggregates in tlist or havingQual */ bool hasAggs pg_node_attr(query_jumble_ignore); /* has window functions in tlist */ @@ -162,6 +165,8 @@ typedef struct Query bool hasRowSecurity pg_node_attr(query_jumble_ignore); /* parser has added an RTE_GROUP RTE */ bool hasGroupRTE pg_node_attr(query_jumble_ignore); + /* uses session variables */ + bool hasSessionVariables pg_node_attr(query_jumble_ignore); /* is a RETURN statement */ bool isReturn pg_node_attr(query_jumble_ignore); @@ -2149,6 +2154,18 @@ typedef struct MergeStmt ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */ } MergeStmt; +/* ---------------------- + * Let Statement + * ---------------------- + */ +typedef struct LetStmt +{ + NodeTag type; + List *target; /* target variable */ + Node *query; /* source expression */ + ParseLoc location; +} LetStmt; + /* ---------------------- * Select Statement * diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h index 011e5a811c3f..ca09d8129463 100644 --- a/src/include/nodes/pathnodes.h +++ b/src/include/nodes/pathnodes.h @@ -182,6 +182,18 @@ typedef struct PlannerGlobal /* partition descriptors */ PartitionDirectory partition_directory pg_node_attr(read_write_ignore); + + /* list of used session variables */ + List *sessionVariables; + + /* Oid of session variable used like target of LET command */ + Oid resultVariable; + + /* oid of session variable used like base node for assignment indirection */ + Oid basenodeSessionVarid; + + /* true, if we do SELECT permission check on basenodeSessionVarid */ + bool basenodeSessionVarSelectCheck; } PlannerGlobal; /* macro for fetching the Plan associated with a SubPlan node */ @@ -532,6 +544,8 @@ struct PlannerInfo bool placeholdersFrozen; /* true if planning a recursive WITH item */ bool hasRecursion; + /* true if session variables were used */ + bool hasSessionVariables; /* * The rangetable index for the RTE_GROUP RTE, or 0 if there is no diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index 658d76225e47..492b9d97e5cc 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -138,6 +138,15 @@ typedef struct PlannedStmt /* non-null if this is utility stmt */ Node *utilityStmt; + List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */ + + /* + * The oid of session variable execluded from permission check. + * This session variable is used as base node of assignment indirection + * (and it is used only there). + */ + int exclSelectPermCheckVarid; + /* statement location in source string (copied from Query) */ /* start location, or -1 if unknown */ ParseLoc stmt_location; diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 7d3b4198f266..3cc2f019abbf 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -378,6 +378,9 @@ typedef struct Const * of the `paramid' field contain the SubLink's subLinkId, and * the low-order 16 bits contain the column number. (This type * of Param is also converted to PARAM_EXEC during planning.) + * + * PARAM_VARIABLE: The parameter is a reference to a session variable + * (paramvarid holds the variable's OID). */ typedef enum ParamKind { @@ -385,6 +388,7 @@ typedef enum ParamKind PARAM_EXEC, PARAM_SUBLINK, PARAM_MULTIEXPR, + PARAM_VARIABLE, } ParamKind; typedef struct Param @@ -397,6 +401,16 @@ typedef struct Param int32 paramtypmod pg_node_attr(query_jumble_ignore); /* OID of collation, or InvalidOid if none */ Oid paramcollid pg_node_attr(query_jumble_ignore); + /* OID of session variable if it is used */ + Oid paramvarid pg_node_attr(query_jumble_ignore); + + /* + * true if param is used as base node of assignment indirection + * (when target of LET statement is an array field or an record field). + * For this param we do not check SELECT access right, because this + * param is used just for execution of UPDATE operation. + */ + bool parambasenode; /* token location, or -1 if unknown */ ParseLoc location; } Param; diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h index 9d3debcab280..ba4305d61a7b 100644 --- a/src/include/optimizer/planmain.h +++ b/src/include/optimizer/planmain.h @@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid); extern void record_plan_type_dependency(PlannerInfo *root, Oid typid); extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context); +extern void pull_up_has_session_variables(PlannerInfo *root); + #endif /* PLANMAIN_H */ diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h index 0ea0265de7c1..8c0affba13bc 100644 --- a/src/include/parser/kwlist.h +++ b/src/include/parser/kwlist.h @@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL) PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL) +PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL) PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL) diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h index 994284019fbb..0b7b69a41597 100644 --- a/src/include/parser/parse_node.h +++ b/src/include/parser/parse_node.h @@ -82,6 +82,8 @@ typedef enum ParseExprKind EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */ EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */ EXPR_KIND_CYCLE_MARK, /* cycle mark value */ + EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */ + EXPR_KIND_LET_TARGET, /* LET target */ } ParseExprKind; @@ -244,6 +246,7 @@ struct ParseState bool p_hasTargetSRFs; bool p_hasSubLinks; bool p_hasModifyingCTE; + bool p_hasSessionVariables; Node *p_last_srf; /* most recent set-returning func/op found */ diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h index ea86954dded7..22082c30008b 100644 --- a/src/include/tcop/cmdtaglist.h +++ b/src/include/tcop/cmdtaglist.h @@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false) PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false) PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false) PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true) +PG_CMDTAG(CMDTAG_LET, "LET", false, false, false) PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false) PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false) PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false) diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h index 00c092e3d7c0..6ce3ea0e617d 100644 --- a/src/include/tcop/dest.h +++ b/src/include/tcop/dest.h @@ -97,6 +97,7 @@ typedef enum DestTransientRel, /* results sent to transient relation */ DestTupleQueue, /* results sent to tuple queue */ DestExplainSerialize, /* results are serialized and discarded */ + DestVariable, /* results sent to session variable */ } CommandDest; /* ---------------- diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c index bb99781c56e3..1cff5efa6f71 100644 --- a/src/pl/plpgsql/src/pl_exec.c +++ b/src/pl/plpgsql/src/pl_exec.c @@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr) query->sortClause || query->limitOffset || query->limitCount || - query->setOperations) + query->setOperations || + query->hasSessionVariables) return false; /* diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out index c36660ce6d32..f22467186e3e 100644 --- a/src/test/regress/expected/session_variables.out +++ b/src/test/regress/expected/session_variables.out @@ -431,3 +431,1235 @@ DROP VARIABLE public.var1; DROP ROLE regress_variable_r1; DROP ROLE regress_variable_r2; DROP ROLE regress_variable_owner; +-- check access rights +CREATE ROLE regress_noowner; +CREATE VARIABLE var1 AS int; +CREATE OR REPLACE FUNCTION sqlfx(int) +RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql; +CREATE OR REPLACE FUNCTION sqlfx_sd(int) +RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER; +CREATE OR REPLACE FUNCTION plpgsqlfx(int) +RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql; +CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int) +RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER; +LET var1 = 10; +-- should be ok +SELECT var1; + var1 +------ + 10 +(1 row) + +SELECT sqlfx(20); + sqlfx +------- + 30 +(1 row) + +SELECT sqlfx_sd(20); + sqlfx_sd +---------- + 30 +(1 row) + +SELECT plpgsqlfx(20); + plpgsqlfx +----------- + 30 +(1 row) + +SELECT plpgsqlfx_sd(20); + plpgsqlfx_sd +-------------- + 30 +(1 row) + +-- should fail +SET ROLE TO regress_noowner; +SELECT var1; +ERROR: permission denied for session variable var1 +SELECT sqlfx(20); +ERROR: permission denied for session variable var1 +CONTEXT: SQL function "sqlfx" statement 1 +SELECT plpgsqlfx(20); +ERROR: permission denied for session variable var1 +CONTEXT: PL/pgSQL expression "$1 + var1" +PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN +-- should be ok +SELECT sqlfx_sd(20); + sqlfx_sd +---------- + 30 +(1 row) + +SELECT plpgsqlfx_sd(20); + plpgsqlfx_sd +-------------- + 30 +(1 row) + +SET ROLE TO DEFAULT; +GRANT SELECT ON VARIABLE var1 TO regress_noowner; +-- should be ok +SET ROLE TO regress_noowner; +SELECT var1; + var1 +------ + 10 +(1 row) + +SELECT sqlfx(20); + sqlfx +------- + 30 +(1 row) + +SELECT plpgsqlfx(20); + plpgsqlfx +----------- + 30 +(1 row) + +SET ROLE TO DEFAULT; +DROP VARIABLE var1; +DROP FUNCTION sqlfx(int); +DROP FUNCTION plpgsqlfx(int); +DROP FUNCTION sqlfx_sd(int); +DROP FUNCTION plpgsqlfx_sd(int); +DROP ROLE regress_noowner; +-- use variables inside views +CREATE VARIABLE var1 AS numeric; +-- use variables in views +CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v); +SELECT * FROM test_view; + result +-------- + 0 + 0 +(2 rows) + +LET var1 = 3.14; +SELECT * FROM test_view; + result +-------- + 4.14 + 5.14 +(2 rows) + +-- start a new session +\c +SELECT * FROM test_view; + result +-------- + 0 + 0 +(2 rows) + +LET var1 = 3.14; +SELECT * FROM test_view; + result +-------- + 4.14 + 5.14 +(2 rows) + +-- should fail, dependency +DROP VARIABLE var1; +ERROR: cannot drop session variable var1 because other objects depend on it +DETAIL: view test_view depends on session variable var1 +HINT: Use DROP ... CASCADE to drop the dependent objects too. +-- should be ok +DROP VARIABLE var1 CASCADE; +NOTICE: drop cascades to view test_view +CREATE VARIABLE var1 text; +CREATE VARIABLE var2 text; +-- use variables in SQL functions +CREATE OR REPLACE FUNCTION sqlfx1(varchar) +RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql; +CREATE OR REPLACE FUNCTION sqlfx2( varchar) +RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql; +LET var1 = 'str1'; +LET var2 = 'str2'; +SELECT sqlfx1(sqlfx2('Hello')); + sqlfx1 +------------------- + str1, str2, Hello +(1 row) + +-- inlining is blocked +EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello')); + QUERY PLAN +------------------------------------------------------ + Result + Output: sqlfx1(sqlfx2('Hello'::character varying)) +(2 rows) + +DROP FUNCTION sqlfx1(varchar); +DROP FUNCTION sqlfx2(varchar); +DROP VARIABLE var1; +DROP VARIABLE var2; +-- access from cached plans should work +CREATE VARIABLE var1 AS numeric; +CREATE VARIABLE var2 AS numeric; +CREATE OR REPLACE FUNCTION plpgsqlfx() +RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql; +CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric) +RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql; +SET plan_cache_mode TO force_generic_plan; +LET var1 = 3.14; +SELECT plpgsqlfx(); + plpgsqlfx +----------- + 3.14 +(1 row) + +LET var1 = 3.14 * 2; +SELECT plpgsqlfx(); + plpgsqlfx +----------- + 6.28 +(1 row) + +SELECT plpgsqlfx2(10.0); + plpgsqlfx2 +------------ + +(1 row) + +SELECT var2; + var2 +------ + 10.0 +(1 row) + +DROP VARIABLE var1; +DROP VARIABLE var2; +-- dependency (plan invalidation) should work +CREATE VARIABLE var1 AS numeric; +CREATE VARIABLE var2 AS numeric; +LET var1 = 3.14 * 3; +SELECT plpgsqlfx(); + plpgsqlfx +----------- + 9.42 +(1 row) + +LET var1 = 3.14 * 4; +SELECT plpgsqlfx(); + plpgsqlfx +----------- + 12.56 +(1 row) + +SELECT plpgsqlfx2(10.0); + plpgsqlfx2 +------------ + +(1 row) + +SELECT var2; + var2 +------ + 10.0 +(1 row) + +DROP VARIABLE var1; +DROP VARIABLE var2; +DROP FUNCTION plpgsqlfx(); +DROP FUNCTION plpgsqlfx2(); +ERROR: function plpgsqlfx2() does not exist +-- dependency on column type +CREATE VARIABLE var1 AS int; +CREATE TABLE testvar(a int, b int, c int); +INSERT INTO testvar VALUES(10,20,30); +ALTER TABLE testvar DROP COLUMN a; +ALTER TABLE testvar DROP COLUMN b; +CREATE FUNCTION plpgsqlfx3() +RETURNS void AS $$ +BEGIN + LET var1 = (SELECT * FROM testvar); + RAISE NOTICE '%', var1; +END +$$ LANGUAGE plpgsql; +-- should be ok +SELECT plpgsqlfx3(); +NOTICE: 30 + plpgsqlfx3 +------------ + +(1 row) + +ALTER TABLE testvar ALTER COLUMN c TYPE numeric; +-- should be ok +SELECT plpgsqlfx3(); +NOTICE: 30 + plpgsqlfx3 +------------ + +(1 row) + +DROP FUNCTION plpgsqlfx3(); +DROP TABLE testvar; +DROP VARIABLE var1; +SET plan_cache_mode TO DEFAULT; +-- repeated execution should not crash +CREATE VARIABLE var1 int; +CREATE TABLE testvar(a int); +INSERT INTO testvar VALUES(1); +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = (SELECT a FROM testvar); + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; +NOTICE: 1 +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = (SELECT a + var1 FROM testvar); + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; +NOTICE: 10 +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = (SELECT a FROM testvar) + var1; + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; +NOTICE: 10 +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = i; + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; +NOTICE: 10 +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = i + var1; + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; +NOTICE: 55 +DROP VARIABLE var1; +DROP TABLE testvar; +-- usage LET statement in plpgsql should work +CREATE VARIABLE var1 int; +CREATE VARIABLE var2 numeric[]; +DO $$ +BEGIN + LET var2 = '{}'::int[]; + FOR i IN 1..10 + LOOP + LET var1 = i; + LET var2[var1] = i; + END LOOP; + RAISE NOTICE 'result array: %', var2; +END; +$$; +NOTICE: result array: {1,2,3,4,5,6,7,8,9,10} +DROP VARIABLE var1; +DROP VARIABLE var2; +-- CALL statement is not supported yet +-- requires direct access to session variable from expression executor +CREATE VARIABLE v int; +CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql; +-- should not crash (but is not supported yet) +CALL p(v); +ERROR: session variable cannot be used as an argument +DO $$ BEGIN CALL p(v); END $$; +ERROR: session variable cannot be used as an argument +CONTEXT: SQL statement "CALL p(v)" +PL/pgSQL function inline_code_block line 1 at CALL +DROP PROCEDURE p(int); +DROP VARIABLE v; +-- EXECUTE statement is not supported yet +-- requires direct access to session variable from expression executor +CREATE VARIABLE v int; +LET v = 20; +PREPARE ptest(int) AS SELECT $1; +-- should fail +EXECUTE ptest(v); +ERROR: session variable cannot be used as an argument +DEALLOCATE ptest; +DROP VARIABLE v; +-- test search path +CREATE SCHEMA svartest; +CREATE VARIABLE svartest.var1 AS numeric; +-- should fail +LET var1 = pi(); +ERROR: session variable "var1" doesn't exist +LINE 1: LET var1 = pi(); + ^ +SELECT var1; +ERROR: column "var1" does not exist +LINE 1: SELECT var1; + ^ +-- should be ok +LET svartest.var1 = pi(); +SELECT svartest.var1; + var1 +------------------ + 3.14159265358979 +(1 row) + +SET search_path TO svartest; +-- should be ok +LET var1 = pi() + 10; +SELECT var1; + var1 +------------------ + 13.1415926535898 +(1 row) + +RESET search_path; +DROP SCHEMA svartest CASCADE; +NOTICE: drop cascades to session variable svartest.var1 +CREATE VARIABLE var1 AS text; +-- variables can be updated under RO transaction +BEGIN; +SET TRANSACTION READ ONLY; +LET var1 = 'hello'; +COMMIT; +SELECT var1; + var1 +------- + hello +(1 row) + +DROP VARIABLE var1; +-- test of domains +CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100); +CREATE VARIABLE var1 AS int_domain; +-- should fail +SELECT var1; +ERROR: domain int_domain does not allow null values +-- should be ok +LET var1 = 1000; +SELECT var1; + var1 +------ + 1000 +(1 row) + +-- should fail +LET var1 = 10; +ERROR: value for domain int_domain violates check constraint "int_domain_check" +-- should fail +LET var1 = NULL; +ERROR: domain int_domain does not allow null values +-- note - domain defaults are not supported yet (like PLpgSQL) +DROP VARIABLE var1; +DROP DOMAIN int_domain; +-- the expression should remain "unknown" +CREATE VARIABLE var1 AS int4multirange[]; +-- should be ok +LET var1 = NULL; +LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}'; +LET var1[2] = '{[5,8),[12,100)}'; +SELECT var1; + var1 +---------------------------------------- + {"{[2,8),[11,14)}","{[5,8),[12,100)}"} +(1 row) + +--It should work in plpgsql too +DO $$ +BEGIN + LET var1 = NULL; + LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}'; + LET var1[2] = '{[5,8),[12,100)}'; + + RAISE NOTICE '%', var1; +END; +$$; +NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"} +DROP VARIABLE var1; +CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int); +LET svartest.var1 = 100; +SELECT svartest.var1; + var1 +------ + 100 +(1 row) + +SET search_path to public, svartest; +SELECT var1; + var1 +------ + 100 +(1 row) + +DROP SCHEMA svartest CASCADE; +NOTICE: drop cascades to 2 other objects +DETAIL: drop cascades to table foo +drop cascades to session variable var1 +CREATE VARIABLE var1 AS int; +CREATE VARIABLE var2 AS int[]; +LET var1 = 2; +LET var2 = '{}'::int[]; +LET var2[var1] = 0; +SELECT var2; + var2 +----------- + [2:2]={0} +(1 row) + +DROP VARIABLE var1, var2; +CREATE VARIABLE var1 AS int; +CREATE VARIABLE var2 AS int[]; +LET var1 = 2; +LET var2 = '{}'::int[]; +SELECT var2; + var2 +------ + {} +(1 row) + +DROP VARIABLE var1, var2; +-- the LET statement should be disallowed in CTE +CREATE VARIABLE var1 AS int; +WITH x AS (LET var1 = 100) SELECT * FROM x; +ERROR: syntax error at or near "LET" +LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x; + ^ +-- should be ok +LET var1 = generate_series(1, 1); +-- should fail +LET var1 = generate_series(1, 2); +ERROR: expression returned more than one row +LET var1 = generate_series(1, 0); +ERROR: expression returned no rows +DROP VARIABLE var1; +-- composite variables +CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2)); +CREATE VARIABLE v1 AS sv_xyz; +CREATE VARIABLE v2 AS sv_xyz; +LET v1 = (1, 2, 3.14); +LET v2 = (10, 20, 3.14 * 10); +-- should work too - there are prepared casts +LET v1 = (1, 2, 3); +SELECT v1; + v1 +------------ + (1,2,3.00) +(1 row) + +SELECT v2; + v2 +--------------- + (10,20,31.40) +(1 row) + +SELECT (v1).*; + x | y | z +---+---+------ + 1 | 2 | 3.00 +(1 row) + +SELECT (v2).*; + x | y | z +----+----+------- + 10 | 20 | 31.40 +(1 row) + +SELECT v1.x + v1.z; + ?column? +---------- + 4.00 +(1 row) + +SELECT v2.x + v2.z; + ?column? +---------- + 41.40 +(1 row) + +-- access to composite fields should be safe too +CREATE ROLE regress_var_test_role; +SET ROLE TO regress_var_test_role; +-- should fail +SELECT v2.x; +ERROR: permission denied for session variable v2 +SET ROLE TO DEFAULT; +DROP VARIABLE v1; +DROP VARIABLE v2; +DROP TYPE sv_xyz; +DROP ROLE regress_var_test_role; +-- should fail, wrong identifier +LET nodb.noschema.novar.nofield.nosubfield = 10; +ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield +LET nodb.noschema.novar.nofield = 10; +ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield +LET nodb.noschema.novar = 10; +ERROR: cross-database references are not implemented: nodb.noschema.novar +CREATE TYPE t1 AS (a int, b numeric, c text); +CREATE VARIABLE v1 AS t1; +LET v1 = (1, pi(), 'hello'); +SELECT v1; + v1 +---------------------------- + (1,3.14159265358979,hello) +(1 row) + +LET v1.b = 10.2222; +SELECT v1; + v1 +------------------- + (1,10.2222,hello) +(1 row) + +-- should fail, attribute doesn't exist +LET v1.x = 10; +ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1 +LINE 1: LET v1.x = 10; + ^ +-- should fail, don't allow multi column query +LET v1 = (NULL::t1).*; +ERROR: assignment expression returned 3 columns +LINE 1: LET v1 = (NULL::t1).*; + ^ +-- allow DROP or ADD ATTRIBUTE on composite types +-- should be ok +ALTER TYPE t1 DROP ATTRIBUTE c; +SELECT v1; + v1 +------------- + (1,10.2222) +(1 row) + +-- should be ok +ALTER TYPE t1 ADD ATTRIBUTE c int; +SELECT v1; + v1 +-------------- + (1,10.2222,) +(1 row) + +LET v1 = (10, 10.3, 20); +SELECT v1; + v1 +-------------- + (10,10.3,20) +(1 row) + +-- should be ok +ALTER TYPE t1 DROP ATTRIBUTE b; +SELECT v1; + v1 +--------- + (10,20) +(1 row) + +-- should fail, disallow data type change +ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int; +ERROR: cannot alter type "t1" because session variable "public.v1" uses it +DROP VARIABLE v1; +DROP TYPE t1; +-- the table type can be used as composite type too +CREATE TABLE svar_test(a int, b numeric, c date); +CREATE VARIABLE var1 AS svar_test; +LET var1 = (10, pi(), '2023-05-26'); +SELECT var1; + var1 +---------------------------------- + (10,3.14159265358979,05-26-2023) +(1 row) + +-- should fail due dependency +ALTER TABLE svar_test ALTER COLUMN a TYPE text; +ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it +-- should fail +DROP TABLE svar_test; +ERROR: cannot drop table svar_test because other objects depend on it +DETAIL: session variable var1 depends on type svar_test +HINT: Use DROP ... CASCADE to drop the dependent objects too. +DROP VARIABLE var1; +DROP TABLE svar_test; +CREATE TYPE vartest_t1 AS (a int, b int); +CREATE VARIABLE var1 AS vartest_t1; +CREATE TABLE vartesttab (xcol int); +CREATE ROLE regress_var_test_role; +GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role; +GRANT SELECT ON TABLE vartesttab TO regress_var_test_role; +SET ROLE TO regress_var_test_role; +-- should be ok +LET var1 = (10, 20); +LET var1.a = 30; +DO $$ +BEGIN + LET var1 = (100, 100); + LET var1.a = 1000; +END; +$$; +-- should fail +SELECT var1.a; +ERROR: permission denied for session variable var1 +SELECT var1; +ERROR: permission denied for session variable var1 +LET var1.a = var1.a + 10; +ERROR: permission denied for session variable var1 +LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10)); +ERROR: permission denied for session variable var1 +DO $$ BEGIN RAISE NOTICE '%', var1; END $$; +ERROR: permission denied for session variable var1 +CONTEXT: PL/pgSQL expression "var1" +PL/pgSQL function inline_code_block line 1 at RAISE +DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$; +ERROR: permission denied for session variable var1 +CONTEXT: PL/pgSQL expression "var1.a" +PL/pgSQL function inline_code_block line 1 at RAISE +DO $$ BEGIN LET var1.a = var1.a + 10; END $$; +ERROR: permission denied for session variable var1 +CONTEXT: SQL statement "LET var1.a = var1.a + 10" +PL/pgSQL function inline_code_block line 1 at SQL statement +SET ROLE TO DEFAULT; +GRANT SELECT ON VARIABLE var1 TO regress_var_test_role; +SET ROLE TO regress_var_test_role; +-- should be ok +SELECT var1.a; + a +------ + 1000 +(1 row) + +SELECT var1; + var1 +------------ + (1000,100) +(1 row) + +LET var1.a = var1.a + 10; +LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10)); +DO $$ BEGIN RAISE NOTICE '%', var1; END $$; +NOTICE: (0,100) +DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$; +NOTICE: 0 +DO $$ BEGIN LET var1.a = var1.a + 10; END $$; +SET ROLE TO DEFAULT; +REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role; +SET ROLE TO regress_var_test_role; +-- should fail again +SELECT var1.a; +ERROR: permission denied for session variable var1 +SELECT var1; +ERROR: permission denied for session variable var1 +LET var1.a = var1.a + 10; +ERROR: permission denied for session variable var1 +LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10)); +ERROR: permission denied for session variable var1 +DO $$ BEGIN RAISE NOTICE '%', var1; END $$; +ERROR: permission denied for session variable var1 +CONTEXT: PL/pgSQL expression "var1" +PL/pgSQL function inline_code_block line 1 at RAISE +DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$; +ERROR: permission denied for session variable var1 +CONTEXT: PL/pgSQL expression "var1.a" +PL/pgSQL function inline_code_block line 1 at RAISE +DO $$ BEGIN LET var1.a = var1.a + 10; END $$; +ERROR: permission denied for session variable var1 +CONTEXT: SQL statement "LET var1.a = var1.a + 10" +PL/pgSQL function inline_code_block line 1 at SQL statement +SET ROLE TO DEFAULT; +DROP VARIABLE var1; +DROP TABLE vartesttab; +DROP ROLE regress_var_test_role; +DROP TYPE vartest_t1; +CREATE TYPE vartest_t1 AS (a int, b int); +CREATE VARIABLE var1 AS text; +CREATE VARIABLE var2 AS vartest_t1; +-- should fail +SELECT var1.a; +ERROR: variable "public.var1" is of type "text", which is not a composite type +LINE 1: SELECT var1.a; + ^ +SELECT var2.c; +ERROR: could not identify column "c" in variable "public.var2" +LINE 1: SELECT var2.c; + ^ +DROP VARIABLE var1; +DROP VARIABLE var2; +DROP TYPE vartest_t1; +CREATE VARIABLE var1 AS int; +LET var1 = 1; +LET var1 = '1'; +LET var1 = 10.1; +-- should fail +LET var1 = '1'::jsonb; +ERROR: variable "public.var1" is of type integer, but expression is of type jsonb +LINE 1: LET var1 = '1'::jsonb; + ^ +HINT: You will need to rewrite or cast the expression. +-- should be ok +LET var1 = '1'::jsonb::int; +-- should fail +LET var1.x = 10; +ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type +LINE 1: LET var1.x = 10; + ^ +DROP VARIABLE var1; +CREATE SCHEMA vartest; +CREATE TYPE vartesttype AS (vartest int); +CREATE VARIABLE vartest.vartest AS vartesttype; +SET SEARCH_PATH TO vartest; +-- should fail +LET vartest.vartest = 1; +ERROR: target "vartest.vartest" of LET command is ambiguous +LINE 1: LET vartest.vartest = 1; + ^ +DROP VARIABLE vartest.vartest; +DROP TYPE vartesttype; +ERROR: type "vartesttype" does not exist +DROP SCHEMA vartest; +SET SEARCH_PATH TO DEFAULT; +-- arrays are supported +CREATE VARIABLE var1 AS numeric[]; +LET var1 = ARRAY[1.1,2.1]; +LET var1[1] = 10.1; +SELECT var1; + var1 +------------ + {10.1,2.1} +(1 row) + +-- LET target doesn't allow srf, should fail +LET var1[generate_series(1,3)] = 100; +ERROR: set-returning functions are not allowed in LET +LINE 1: LET var1[generate_series(1,3)] = 100; + ^ +DROP VARIABLE var1; +-- arrays inside composite +CREATE TYPE t1 AS (a numeric, b numeric[]); +CREATE VARIABLE var1 AS t1; +LET var1 = (10.1, ARRAY[0.0, 0.0]); +LET var1.a = 10.2; +SELECT var1; + var1 +-------------------- + (10.2,"{0.0,0.0}") +(1 row) + +LET var1.b[1] = 10.3; +SELECT var1; + var1 +--------------------- + (10.2,"{10.3,0.0}") +(1 row) + +DROP VARIABLE var1; +DROP TYPE t1; +-- Encourage use of parallel plans +SET parallel_setup_cost = 0; +SET parallel_tuple_cost = 0; +SET min_parallel_table_scan_size = 0; +SET max_parallel_workers_per_gather = 2; +-- test on query with workers +CREATE TABLE svar_test(a int); +INSERT INTO svar_test SELECT * FROM generate_series(1,1000); +ANALYZE svar_test; +CREATE VARIABLE zero int; +LET zero = 0; +-- result should be 100 +SELECT count(*) FROM svar_test WHERE a%10 = zero; + count +------- + 100 +(1 row) + +-- parallel execution is not supported yet +EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero; + QUERY PLAN +----------------------------------- + Aggregate + -> Seq Scan on svar_test + Filter: ((a % 10) = zero) +(3 rows) + +LET zero = (SELECT count(*) FROM svar_test); +-- result should be 1000 +SELECT zero; + zero +------ + 1000 +(1 row) + +DROP VARIABLE zero; +DROP TABLE svar_test; +RESET parallel_setup_cost; +RESET parallel_tuple_cost; +RESET min_parallel_table_scan_size; +RESET max_parallel_workers_per_gather; +-- the result of view should be same in parallel mode too +CREATE VARIABLE var1 AS int; +LET var1 = 10; +CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result; +SELECT * FROM var1view; + result +-------- + 10 +(1 row) + +SET debug_parallel_query TO on; +SELECT * FROM var1view; + result +-------- + 10 +(1 row) + +SET debug_parallel_query TO off; +DROP VIEW var1view; +DROP VARIABLE var1; +CREATE VARIABLE varid int; +CREATE TABLE svar_test(id int, v int); +LET varid = 1; +INSERT INTO svar_test VALUES(varid, 100); +SELECT * FROM svar_test; + id | v +----+----- + 1 | 100 +(1 row) + +UPDATE svar_test SET v = 200 WHERE id = varid; +SELECT * FROM svar_test; + id | v +----+----- + 1 | 200 +(1 row) + +DELETE FROM svar_test WHERE id = varid; +SELECT * FROM svar_test; + id | v +----+--- +(0 rows) + +DROP TABLE svar_test; +DROP VARIABLE varid; +-- visibility check +-- variables should be shadowed always +CREATE VARIABLE var1 AS text; +SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class'; + relname +---------- + pg_class +(1 row) + +DROP VARIABLE var1; +CREATE TABLE xxtab(avar int); +INSERT INTO xxtab VALUES(333); +CREATE TYPE xxtype AS (avar int); +CREATE VARIABLE xxtab AS xxtype; +INSERT INTO xxtab VALUES(10); +-- it is ambiguous, but columns are preferred +SELECT xxtab.avar FROM xxtab; + avar +------ + 333 + 10 +(2 rows) + +-- should be ok +SELECT avar FROM xxtab; + avar +------ + 333 + 10 +(2 rows) + +CREATE VARIABLE public.avar AS int; +-- should be ok, see the table +SELECT avar FROM xxtab; + avar +------ + 333 + 10 +(2 rows) + +-- should be ok +SELECT public.avar FROM xxtab; + avar +------ + + +(2 rows) + +DROP VARIABLE xxtab; +SELECT xxtab.avar FROM xxtab; + avar +------ + 333 + 10 +(2 rows) + +DROP VARIABLE public.avar; +DROP TYPE xxtype; +DROP TABLE xxtab; +-- The variable can be shadowed by table or by alias +CREATE TYPE public.svar_type AS (a int, b int, c int); +CREATE VARIABLE public.svar AS public.svar_type; +CREATE TABLE public.svar(a int, b int); +INSERT INTO public.svar VALUES(10, 20); +LET public.svar = (100, 200, 300); +-- should be ok +-- show table +SELECT * FROM public.svar; + a | b +----+---- + 10 | 20 +(1 row) + +SELECT svar.a FROM public.svar; + a +---- + 10 +(1 row) + +SELECT svar.* FROM public.svar; + a | b +----+---- + 10 | 20 +(1 row) + +-- show variable +SELECT public.svar; + svar +--------------- + (100,200,300) +(1 row) + +SELECT public.svar.c; + c +----- + 300 +(1 row) + +SELECT (public.svar).*; + a | b | c +-----+-----+----- + 100 | 200 | 300 +(1 row) + +-- the variable is shadowed, raise error +SELECT public.svar.c FROM public.svar; +ERROR: column svar.c does not exist +LINE 1: SELECT public.svar.c FROM public.svar; + ^ +-- can be fixed by alias +SELECT public.svar.c FROM public.svar x; + c +----- + 300 +(1 row) + +SELECT svar.a FROM public.svar; + a +---- + 10 +(1 row) + +SELECT svar.* FROM public.svar; + a | b +----+---- + 10 | 20 +(1 row) + +-- show variable +SELECT public.svar; + svar +--------------- + (100,200,300) +(1 row) + +SELECT public.svar.c; + c +----- + 300 +(1 row) + +SELECT (public.svar).*; + a | b | c +-----+-----+----- + 100 | 200 | 300 +(1 row) + +-- the variable is shadowed, raise error +SELECT public.svar.c FROM public.svar; +ERROR: column svar.c does not exist +LINE 1: SELECT public.svar.c FROM public.svar; + ^ +-- can be fixed by alias +SELECT public.svar.c FROM public.svar x; + c +----- + 300 +(1 row) + +DROP VARIABLE public.svar; +DROP TABLE public.svar; +DROP TYPE public.svar_type; +-- The sequence ident.* cannot be used by reference to session variable, +-- and in this case, there is not collision +CREATE SCHEMA vartest; +SET SEARCH_PATH TO vartest; +CREATE TABLE vartest_foo(a int, b int); +INSERT INTO vartest_foo VALUES(10,20), (30,40); +CREATE VARIABLE var1 AS vartest_foo; +LET var1 = (100,200); +-- should to fail +SELECT var1.* FROM vartest_foo; +ERROR: missing FROM-clause entry for table "var1" +LINE 1: SELECT var1.* FROM vartest_foo; + ^ +-- should be ok +SELECT var1.* FROM vartest_foo var1; + a | b +----+---- + 10 | 20 + 30 | 40 +(2 rows) + +-- should to fail +SELECT count(var1.*) FROM vartest_foo; +ERROR: missing FROM-clause entry for table "var1" +LINE 1: SELECT count(var1.*) FROM vartest_foo; + ^ +-- should be ok +SELECT count(var1.*) FROM vartest_foo var1; + count +------- + 2 +(1 row) + +SET SEARCH_PATH TO DEFAULT; +DROP SCHEMA vartest CASCADE; +NOTICE: drop cascades to 2 other objects +DETAIL: drop cascades to table vartest.vartest_foo +drop cascades to session variable vartest.var1 +CREATE TYPE ab AS (a integer, b integer); +CREATE VARIABLE v_ab AS ab; +CREATE TABLE v_ab (a integer, b integer); +INSERT INTO v_ab VALUES(10,20); +-- we should see table +SELECT v_ab.a FROM v_ab; + a +---- + 10 +(1 row) + +CREATE SCHEMA v_ab; +CREATE VARIABLE v_ab.a AS integer; +-- we should see table +SELECT v_ab.a FROM v_ab; + a +---- + 10 +(1 row) + +DROP VARIABLE v_ab; +DROP TABLE v_ab; +DROP TYPE ab; +DROP VARIABLE v_ab.a; +DROP SCHEMA v_ab; +CREATE TYPE t_am_type AS (b int); +CREATE SCHEMA xxx_am; +SET search_path TO public; +CREATE VARIABLE xxx_am AS t_am_type; +LET xxx_am = ROW(10); +-- should be ok +SELECT xxx_am; + xxx_am +-------- + (10) +(1 row) + +CREATE VARIABLE xxx_am.b AS int; +LET :"DBNAME".xxx_am.b = 20; +-- should be still ok +SELECT xxx_am; + xxx_am +-------- + (10) +(1 row) + +-- should fail, the reference should be ambiguous +SELECT xxx_am.b; +ERROR: session variable reference "xxx_am.b" is ambiguous +LINE 1: SELECT xxx_am.b; + ^ +-- enhanced references should be ok +SELECT public.xxx_am.b; + b +---- + 10 +(1 row) + +SELECT :"DBNAME".xxx_am.b; + b +---- + 20 +(1 row) + +CREATE TABLE xxx_am(b int); +INSERT INTO xxx_am VALUES(10); +-- we should see table +SELECT xxx_am.b FROM xxx_am; + b +---- + 10 +(1 row) + +SELECT x.b FROM xxx_am x; + b +---- + 10 +(1 row) + +DROP TABLE xxx_am; +DROP VARIABLE public.xxx_am; +DROP VARIABLE xxx_am.b; +DROP SCHEMA xxx_am; +CREATE SCHEMA :"DBNAME"; +CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type; +CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int; +SET search_path TO :"DBNAME"; +-- should be ambiguous +SELECT :"DBNAME".b; +ERROR: session variable reference "regression.b" is ambiguous +LINE 1: SELECT "regression".b; + ^ +-- should be ambiguous too +SELECT :"DBNAME".:"DBNAME".b; +ERROR: session variable reference "regression.regression.b" is ambiguous +LINE 1: SELECT "regression"."regression".b; + ^ +CREATE TABLE :"DBNAME"(b int); +-- should be ok +SELECT :"DBNAME".b FROM :"DBNAME"; + b +--- +(0 rows) + +DROP TABLE :"DBNAME"; +DROP VARIABLE :"DBNAME".:"DBNAME".b; +DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME"; +DROP SCHEMA :"DBNAME"; +RESET search_path; diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql index eeb0f94ca3cd..e72360d5254b 100644 --- a/src/test/regress/sql/session_variables.sql +++ b/src/test/regress/sql/session_variables.sql @@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1; DROP ROLE regress_variable_r2; DROP ROLE regress_variable_owner; + +-- check access rights +CREATE ROLE regress_noowner; + +CREATE VARIABLE var1 AS int; + +CREATE OR REPLACE FUNCTION sqlfx(int) +RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql; + +CREATE OR REPLACE FUNCTION sqlfx_sd(int) +RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER; + +CREATE OR REPLACE FUNCTION plpgsqlfx(int) +RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql; + +CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int) +RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER; + +LET var1 = 10; +-- should be ok +SELECT var1; +SELECT sqlfx(20); +SELECT sqlfx_sd(20); +SELECT plpgsqlfx(20); +SELECT plpgsqlfx_sd(20); + +-- should fail +SET ROLE TO regress_noowner; + +SELECT var1; +SELECT sqlfx(20); +SELECT plpgsqlfx(20); + +-- should be ok +SELECT sqlfx_sd(20); +SELECT plpgsqlfx_sd(20); + +SET ROLE TO DEFAULT; +GRANT SELECT ON VARIABLE var1 TO regress_noowner; + +-- should be ok +SET ROLE TO regress_noowner; + +SELECT var1; +SELECT sqlfx(20); +SELECT plpgsqlfx(20); + +SET ROLE TO DEFAULT; +DROP VARIABLE var1; +DROP FUNCTION sqlfx(int); +DROP FUNCTION plpgsqlfx(int); +DROP FUNCTION sqlfx_sd(int); +DROP FUNCTION plpgsqlfx_sd(int); + +DROP ROLE regress_noowner; + +-- use variables inside views +CREATE VARIABLE var1 AS numeric; + +-- use variables in views +CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v); +SELECT * FROM test_view; +LET var1 = 3.14; +SELECT * FROM test_view; + +-- start a new session +\c + +SELECT * FROM test_view; +LET var1 = 3.14; +SELECT * FROM test_view; + +-- should fail, dependency +DROP VARIABLE var1; + +-- should be ok +DROP VARIABLE var1 CASCADE; + +CREATE VARIABLE var1 text; +CREATE VARIABLE var2 text; + +-- use variables in SQL functions +CREATE OR REPLACE FUNCTION sqlfx1(varchar) +RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql; + +CREATE OR REPLACE FUNCTION sqlfx2( varchar) +RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql; + +LET var1 = 'str1'; +LET var2 = 'str2'; + +SELECT sqlfx1(sqlfx2('Hello')); + +-- inlining is blocked +EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello')); + +DROP FUNCTION sqlfx1(varchar); +DROP FUNCTION sqlfx2(varchar); +DROP VARIABLE var1; +DROP VARIABLE var2; + +-- access from cached plans should work +CREATE VARIABLE var1 AS numeric; +CREATE VARIABLE var2 AS numeric; + +CREATE OR REPLACE FUNCTION plpgsqlfx() +RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql; + +CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric) +RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql; + +SET plan_cache_mode TO force_generic_plan; + +LET var1 = 3.14; +SELECT plpgsqlfx(); +LET var1 = 3.14 * 2; +SELECT plpgsqlfx(); + +SELECT plpgsqlfx2(10.0); +SELECT var2; + +DROP VARIABLE var1; +DROP VARIABLE var2; + +-- dependency (plan invalidation) should work +CREATE VARIABLE var1 AS numeric; +CREATE VARIABLE var2 AS numeric; + +LET var1 = 3.14 * 3; +SELECT plpgsqlfx(); +LET var1 = 3.14 * 4; +SELECT plpgsqlfx(); + +SELECT plpgsqlfx2(10.0); +SELECT var2; + +DROP VARIABLE var1; +DROP VARIABLE var2; +DROP FUNCTION plpgsqlfx(); +DROP FUNCTION plpgsqlfx2(); + +-- dependency on column type +CREATE VARIABLE var1 AS int; +CREATE TABLE testvar(a int, b int, c int); +INSERT INTO testvar VALUES(10,20,30); + +ALTER TABLE testvar DROP COLUMN a; +ALTER TABLE testvar DROP COLUMN b; + +CREATE FUNCTION plpgsqlfx3() +RETURNS void AS $$ +BEGIN + LET var1 = (SELECT * FROM testvar); + RAISE NOTICE '%', var1; +END +$$ LANGUAGE plpgsql; + +-- should be ok +SELECT plpgsqlfx3(); + +ALTER TABLE testvar ALTER COLUMN c TYPE numeric; + +-- should be ok +SELECT plpgsqlfx3(); + +DROP FUNCTION plpgsqlfx3(); +DROP TABLE testvar; +DROP VARIABLE var1; + +SET plan_cache_mode TO DEFAULT; + +-- repeated execution should not crash +CREATE VARIABLE var1 int; +CREATE TABLE testvar(a int); +INSERT INTO testvar VALUES(1); + +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = (SELECT a FROM testvar); + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; + +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = (SELECT a + var1 FROM testvar); + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; + +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = (SELECT a FROM testvar) + var1; + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; + +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = i; + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; + +DO $$ +BEGIN + LET var1 = 0; + FOR i IN 1..10 + LOOP + LET var1 = i + var1; + END LOOP; + RAISE NOTICE '%', var1; +END; +$$; + +DROP VARIABLE var1; +DROP TABLE testvar; + +-- usage LET statement in plpgsql should work +CREATE VARIABLE var1 int; +CREATE VARIABLE var2 numeric[]; + +DO $$ +BEGIN + LET var2 = '{}'::int[]; + FOR i IN 1..10 + LOOP + LET var1 = i; + LET var2[var1] = i; + END LOOP; + RAISE NOTICE 'result array: %', var2; +END; +$$; + +DROP VARIABLE var1; +DROP VARIABLE var2; + +-- CALL statement is not supported yet +-- requires direct access to session variable from expression executor +CREATE VARIABLE v int; + +CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql; + +-- should not crash (but is not supported yet) +CALL p(v); + +DO $$ BEGIN CALL p(v); END $$; + +DROP PROCEDURE p(int); +DROP VARIABLE v; + +-- EXECUTE statement is not supported yet +-- requires direct access to session variable from expression executor +CREATE VARIABLE v int; +LET v = 20; +PREPARE ptest(int) AS SELECT $1; + +-- should fail +EXECUTE ptest(v); + +DEALLOCATE ptest; +DROP VARIABLE v; + +-- test search path +CREATE SCHEMA svartest; +CREATE VARIABLE svartest.var1 AS numeric; + +-- should fail +LET var1 = pi(); +SELECT var1; + +-- should be ok +LET svartest.var1 = pi(); +SELECT svartest.var1; + +SET search_path TO svartest; + +-- should be ok +LET var1 = pi() + 10; +SELECT var1; + +RESET search_path; +DROP SCHEMA svartest CASCADE; + +CREATE VARIABLE var1 AS text; + +-- variables can be updated under RO transaction +BEGIN; +SET TRANSACTION READ ONLY; +LET var1 = 'hello'; +COMMIT; + +SELECT var1; + +DROP VARIABLE var1; + +-- test of domains +CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100); +CREATE VARIABLE var1 AS int_domain; + +-- should fail +SELECT var1; + +-- should be ok +LET var1 = 1000; +SELECT var1; + +-- should fail +LET var1 = 10; + +-- should fail +LET var1 = NULL; + +-- note - domain defaults are not supported yet (like PLpgSQL) + +DROP VARIABLE var1; +DROP DOMAIN int_domain; + +-- the expression should remain "unknown" +CREATE VARIABLE var1 AS int4multirange[]; +-- should be ok +LET var1 = NULL; +LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}'; +LET var1[2] = '{[5,8),[12,100)}'; +SELECT var1; + +--It should work in plpgsql too +DO $$ +BEGIN + LET var1 = NULL; + LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}'; + LET var1[2] = '{[5,8),[12,100)}'; + + RAISE NOTICE '%', var1; +END; +$$; + +DROP VARIABLE var1; + +CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int); +LET svartest.var1 = 100; +SELECT svartest.var1; + +SET search_path to public, svartest; + +SELECT var1; + +DROP SCHEMA svartest CASCADE; + +CREATE VARIABLE var1 AS int; +CREATE VARIABLE var2 AS int[]; + +LET var1 = 2; +LET var2 = '{}'::int[]; + +LET var2[var1] = 0; + +SELECT var2; + +DROP VARIABLE var1, var2; + +CREATE VARIABLE var1 AS int; +CREATE VARIABLE var2 AS int[]; + +LET var1 = 2; +LET var2 = '{}'::int[]; + +SELECT var2; + +DROP VARIABLE var1, var2; + +-- the LET statement should be disallowed in CTE +CREATE VARIABLE var1 AS int; +WITH x AS (LET var1 = 100) SELECT * FROM x; + +-- should be ok +LET var1 = generate_series(1, 1); + +-- should fail +LET var1 = generate_series(1, 2); +LET var1 = generate_series(1, 0); + +DROP VARIABLE var1; + +-- composite variables +CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2)); + +CREATE VARIABLE v1 AS sv_xyz; +CREATE VARIABLE v2 AS sv_xyz; + +LET v1 = (1, 2, 3.14); +LET v2 = (10, 20, 3.14 * 10); + +-- should work too - there are prepared casts +LET v1 = (1, 2, 3); + +SELECT v1; +SELECT v2; +SELECT (v1).*; +SELECT (v2).*; + +SELECT v1.x + v1.z; +SELECT v2.x + v2.z; + +-- access to composite fields should be safe too +CREATE ROLE regress_var_test_role; + +SET ROLE TO regress_var_test_role; + +-- should fail +SELECT v2.x; + +SET ROLE TO DEFAULT; + +DROP VARIABLE v1; +DROP VARIABLE v2; +DROP TYPE sv_xyz; +DROP ROLE regress_var_test_role; + +-- should fail, wrong identifier +LET nodb.noschema.novar.nofield.nosubfield = 10; +LET nodb.noschema.novar.nofield = 10; +LET nodb.noschema.novar = 10; + +CREATE TYPE t1 AS (a int, b numeric, c text); + +CREATE VARIABLE v1 AS t1; +LET v1 = (1, pi(), 'hello'); +SELECT v1; +LET v1.b = 10.2222; +SELECT v1; + +-- should fail, attribute doesn't exist +LET v1.x = 10; + +-- should fail, don't allow multi column query +LET v1 = (NULL::t1).*; + +-- allow DROP or ADD ATTRIBUTE on composite types +-- should be ok +ALTER TYPE t1 DROP ATTRIBUTE c; +SELECT v1; + +-- should be ok +ALTER TYPE t1 ADD ATTRIBUTE c int; +SELECT v1; + +LET v1 = (10, 10.3, 20); +SELECT v1; + +-- should be ok +ALTER TYPE t1 DROP ATTRIBUTE b; +SELECT v1; + +-- should fail, disallow data type change +ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int; + +DROP VARIABLE v1; +DROP TYPE t1; + +-- the table type can be used as composite type too +CREATE TABLE svar_test(a int, b numeric, c date); +CREATE VARIABLE var1 AS svar_test; + +LET var1 = (10, pi(), '2023-05-26'); +SELECT var1; + +-- should fail due dependency +ALTER TABLE svar_test ALTER COLUMN a TYPE text; + +-- should fail +DROP TABLE svar_test; + +DROP VARIABLE var1; +DROP TABLE svar_test; + +CREATE TYPE vartest_t1 AS (a int, b int); +CREATE VARIABLE var1 AS vartest_t1; +CREATE TABLE vartesttab (xcol int); + +CREATE ROLE regress_var_test_role; + +GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role; +GRANT SELECT ON TABLE vartesttab TO regress_var_test_role; + +SET ROLE TO regress_var_test_role; + +-- should be ok +LET var1 = (10, 20); +LET var1.a = 30; + +DO $$ +BEGIN + LET var1 = (100, 100); + LET var1.a = 1000; +END; +$$; + +-- should fail +SELECT var1.a; +SELECT var1; +LET var1.a = var1.a + 10; +LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10)); + +DO $$ BEGIN RAISE NOTICE '%', var1; END $$; +DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$; +DO $$ BEGIN LET var1.a = var1.a + 10; END $$; + +SET ROLE TO DEFAULT; +GRANT SELECT ON VARIABLE var1 TO regress_var_test_role; +SET ROLE TO regress_var_test_role; + +-- should be ok +SELECT var1.a; +SELECT var1; +LET var1.a = var1.a + 10; +LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10)); + +DO $$ BEGIN RAISE NOTICE '%', var1; END $$; +DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$; +DO $$ BEGIN LET var1.a = var1.a + 10; END $$; + +SET ROLE TO DEFAULT; +REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role; +SET ROLE TO regress_var_test_role; + +-- should fail again +SELECT var1.a; +SELECT var1; +LET var1.a = var1.a + 10; +LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10)); + +DO $$ BEGIN RAISE NOTICE '%', var1; END $$; +DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$; +DO $$ BEGIN LET var1.a = var1.a + 10; END $$; + +SET ROLE TO DEFAULT; + +DROP VARIABLE var1; +DROP TABLE vartesttab; +DROP ROLE regress_var_test_role; +DROP TYPE vartest_t1; + +CREATE TYPE vartest_t1 AS (a int, b int); + +CREATE VARIABLE var1 AS text; +CREATE VARIABLE var2 AS vartest_t1; + +-- should fail +SELECT var1.a; +SELECT var2.c; + +DROP VARIABLE var1; +DROP VARIABLE var2; +DROP TYPE vartest_t1; + +CREATE VARIABLE var1 AS int; + +LET var1 = 1; +LET var1 = '1'; +LET var1 = 10.1; + +-- should fail +LET var1 = '1'::jsonb; + +-- should be ok +LET var1 = '1'::jsonb::int; + +-- should fail +LET var1.x = 10; + +DROP VARIABLE var1; + +CREATE SCHEMA vartest; +CREATE TYPE vartesttype AS (vartest int); +CREATE VARIABLE vartest.vartest AS vartesttype; +SET SEARCH_PATH TO vartest; + +-- should fail +LET vartest.vartest = 1; + +DROP VARIABLE vartest.vartest; +DROP TYPE vartesttype; +DROP SCHEMA vartest; +SET SEARCH_PATH TO DEFAULT; + +-- arrays are supported +CREATE VARIABLE var1 AS numeric[]; +LET var1 = ARRAY[1.1,2.1]; +LET var1[1] = 10.1; +SELECT var1; + +-- LET target doesn't allow srf, should fail +LET var1[generate_series(1,3)] = 100; + +DROP VARIABLE var1; + +-- arrays inside composite +CREATE TYPE t1 AS (a numeric, b numeric[]); +CREATE VARIABLE var1 AS t1; +LET var1 = (10.1, ARRAY[0.0, 0.0]); +LET var1.a = 10.2; +SELECT var1; +LET var1.b[1] = 10.3; +SELECT var1; + +DROP VARIABLE var1; +DROP TYPE t1; + +-- Encourage use of parallel plans +SET parallel_setup_cost = 0; +SET parallel_tuple_cost = 0; +SET min_parallel_table_scan_size = 0; +SET max_parallel_workers_per_gather = 2; + +-- test on query with workers +CREATE TABLE svar_test(a int); +INSERT INTO svar_test SELECT * FROM generate_series(1,1000); +ANALYZE svar_test; +CREATE VARIABLE zero int; +LET zero = 0; + +-- result should be 100 +SELECT count(*) FROM svar_test WHERE a%10 = zero; + +-- parallel execution is not supported yet +EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero; + +LET zero = (SELECT count(*) FROM svar_test); + +-- result should be 1000 +SELECT zero; + +DROP VARIABLE zero; +DROP TABLE svar_test; + +RESET parallel_setup_cost; +RESET parallel_tuple_cost; +RESET min_parallel_table_scan_size; +RESET max_parallel_workers_per_gather; + +-- the result of view should be same in parallel mode too +CREATE VARIABLE var1 AS int; +LET var1 = 10; + +CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result; + +SELECT * FROM var1view; + +SET debug_parallel_query TO on; + +SELECT * FROM var1view; + +SET debug_parallel_query TO off; + +DROP VIEW var1view; +DROP VARIABLE var1; + +CREATE VARIABLE varid int; +CREATE TABLE svar_test(id int, v int); + +LET varid = 1; +INSERT INTO svar_test VALUES(varid, 100); +SELECT * FROM svar_test; +UPDATE svar_test SET v = 200 WHERE id = varid; +SELECT * FROM svar_test; +DELETE FROM svar_test WHERE id = varid; +SELECT * FROM svar_test; + +DROP TABLE svar_test; +DROP VARIABLE varid; + +-- visibility check +-- variables should be shadowed always +CREATE VARIABLE var1 AS text; +SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class'; + +DROP VARIABLE var1; + +CREATE TABLE xxtab(avar int); + +INSERT INTO xxtab VALUES(333); + +CREATE TYPE xxtype AS (avar int); + +CREATE VARIABLE xxtab AS xxtype; + +INSERT INTO xxtab VALUES(10); + +-- it is ambiguous, but columns are preferred +SELECT xxtab.avar FROM xxtab; + +-- should be ok +SELECT avar FROM xxtab; + +CREATE VARIABLE public.avar AS int; + +-- should be ok, see the table +SELECT avar FROM xxtab; + +-- should be ok +SELECT public.avar FROM xxtab; + +DROP VARIABLE xxtab; + +SELECT xxtab.avar FROM xxtab; + +DROP VARIABLE public.avar; + +DROP TYPE xxtype; + +DROP TABLE xxtab; + +-- The variable can be shadowed by table or by alias +CREATE TYPE public.svar_type AS (a int, b int, c int); +CREATE VARIABLE public.svar AS public.svar_type; + +CREATE TABLE public.svar(a int, b int); + +INSERT INTO public.svar VALUES(10, 20); + +LET public.svar = (100, 200, 300); + +-- should be ok +-- show table +SELECT * FROM public.svar; +SELECT svar.a FROM public.svar; +SELECT svar.* FROM public.svar; + +-- show variable +SELECT public.svar; +SELECT public.svar.c; +SELECT (public.svar).*; + +-- the variable is shadowed, raise error +SELECT public.svar.c FROM public.svar; + +-- can be fixed by alias +SELECT public.svar.c FROM public.svar x; + +SELECT svar.a FROM public.svar; +SELECT svar.* FROM public.svar; + +-- show variable +SELECT public.svar; +SELECT public.svar.c; +SELECT (public.svar).*; + +-- the variable is shadowed, raise error +SELECT public.svar.c FROM public.svar; + +-- can be fixed by alias +SELECT public.svar.c FROM public.svar x; + +DROP VARIABLE public.svar; +DROP TABLE public.svar; +DROP TYPE public.svar_type; + +-- The sequence ident.* cannot be used by reference to session variable, +-- and in this case, there is not collision +CREATE SCHEMA vartest; +SET SEARCH_PATH TO vartest; +CREATE TABLE vartest_foo(a int, b int); +INSERT INTO vartest_foo VALUES(10,20), (30,40); + +CREATE VARIABLE var1 AS vartest_foo; +LET var1 = (100,200); + +-- should to fail +SELECT var1.* FROM vartest_foo; + +-- should be ok +SELECT var1.* FROM vartest_foo var1; + +-- should to fail +SELECT count(var1.*) FROM vartest_foo; + +-- should be ok +SELECT count(var1.*) FROM vartest_foo var1; + +SET SEARCH_PATH TO DEFAULT; +DROP SCHEMA vartest CASCADE; + +CREATE TYPE ab AS (a integer, b integer); + +CREATE VARIABLE v_ab AS ab; + +CREATE TABLE v_ab (a integer, b integer); +INSERT INTO v_ab VALUES(10,20); + +-- we should see table +SELECT v_ab.a FROM v_ab; + +CREATE SCHEMA v_ab; + +CREATE VARIABLE v_ab.a AS integer; + +-- we should see table +SELECT v_ab.a FROM v_ab; + +DROP VARIABLE v_ab; +DROP TABLE v_ab; +DROP TYPE ab; +DROP VARIABLE v_ab.a; +DROP SCHEMA v_ab; + +CREATE TYPE t_am_type AS (b int); +CREATE SCHEMA xxx_am; + +SET search_path TO public; + +CREATE VARIABLE xxx_am AS t_am_type; +LET xxx_am = ROW(10); + +-- should be ok +SELECT xxx_am; + +CREATE VARIABLE xxx_am.b AS int; +LET :"DBNAME".xxx_am.b = 20; + +-- should be still ok +SELECT xxx_am; + +-- should fail, the reference should be ambiguous +SELECT xxx_am.b; + +-- enhanced references should be ok +SELECT public.xxx_am.b; +SELECT :"DBNAME".xxx_am.b; + +CREATE TABLE xxx_am(b int); +INSERT INTO xxx_am VALUES(10); + +-- we should see table +SELECT xxx_am.b FROM xxx_am; +SELECT x.b FROM xxx_am x; + +DROP TABLE xxx_am; +DROP VARIABLE public.xxx_am; +DROP VARIABLE xxx_am.b; +DROP SCHEMA xxx_am; + +CREATE SCHEMA :"DBNAME"; + +CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type; +CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int; + +SET search_path TO :"DBNAME"; + +-- should be ambiguous +SELECT :"DBNAME".b; + +-- should be ambiguous too +SELECT :"DBNAME".:"DBNAME".b; + +CREATE TABLE :"DBNAME"(b int); + +-- should be ok +SELECT :"DBNAME".b FROM :"DBNAME"; + +DROP TABLE :"DBNAME"; + +DROP VARIABLE :"DBNAME".:"DBNAME".b; +DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME"; +DROP SCHEMA :"DBNAME"; + +RESET search_path; diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index 517386fb8646..179ce99ca9c4 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -1541,6 +1541,7 @@ LargeObjectDesc Latch LauncherLastStartTimesEntry LerpFunc +LetStmt LexDescr LexemeEntry LexemeHashKey @@ -2698,6 +2699,7 @@ SerializedTransactionState Session SessionBackupState SessionEndType +SessionVariableValue SetConstraintState SetConstraintStateData SetConstraintTriggerData @@ -2896,6 +2898,9 @@ SupportRequestRows SupportRequestSelectivity SupportRequestSimplify SupportRequestWFuncMonotonic +SVariable +SVariableData +SVariableState Syn SyncOps SyncRepConfigData From f712ab93e29f5edaa5c189346e703cbc79374aba Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Fri, 19 Jan 2024 20:01:56 +0100 Subject: [PATCH 3/8] function pg_session_variables for cleaning tests This is a function designed for testing and debugging. It returns the content of sessionvars as-is, and can therefore display entries about session variables that were dropped but for which this backend didn't process the shared invalidations yet. --- src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++ src/include/catalog/pg_proc.dat | 8 +++ 2 files changed, 100 insertions(+) diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c index d2891a1dcb72..fa16f47072ef 100644 --- a/src/backend/commands/session_variable.c +++ b/src/backend/commands/session_variable.c @@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate, PopActiveSnapshot(); } + +/* + * pg_session_variables - designed for testing + * + * This is a function designed for testing and debugging. It returns the + * content of session variables as-is, and can therefore display data about + * session variables that were dropped, but for which this backend didn't + * process the shared invalidations yet. + */ +Datum +pg_session_variables(PG_FUNCTION_ARGS) +{ +#define NUM_PG_SESSION_VARIABLES_ATTS 8 + + InitMaterializedSRF(fcinfo, 0); + + if (sessionvars) + { + ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + HASH_SEQ_STATUS status; + SVariable svar; + + hash_seq_init(&status, sessionvars); + + while ((svar = (SVariable) hash_seq_search(&status)) != NULL) + { + Datum values[NUM_PG_SESSION_VARIABLES_ATTS]; + bool nulls[NUM_PG_SESSION_VARIABLES_ATTS]; + HeapTuple tp; + bool var_is_valid = false; + + memset(values, 0, sizeof(values)); + memset(nulls, 0, sizeof(nulls)); + + values[0] = ObjectIdGetDatum(svar->varid); + values[3] = ObjectIdGetDatum(svar->typid); + + /* + * It is possible that the variable has been dropped from the + * catalog, but not yet purged from the hash table. + */ + tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid)); + + if (HeapTupleIsValid(tp)) + { + Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp); + + /* + * It is also possible that a variable has been dropped and + * someone created a new variable with the same object ID. Use + * the catalog information only if that is not the case. + */ + if (svar->create_lsn == varform->varcreate_lsn) + { + values[1] = CStringGetTextDatum( + get_namespace_name(varform->varnamespace)); + + values[2] = CStringGetTextDatum(NameStr(varform->varname)); + values[4] = CStringGetTextDatum(format_type_be(svar->typid)); + values[5] = BoolGetDatum(false); + + values[6] = BoolGetDatum( + object_aclcheck(VariableRelationId, svar->varid, + GetUserId(), ACL_SELECT) == ACLCHECK_OK); + + values[7] = BoolGetDatum( + object_aclcheck(VariableRelationId, svar->varid, + GetUserId(), ACL_UPDATE) == ACLCHECK_OK); + + var_is_valid = true; + } + + ReleaseSysCache(tp); + } + + /* if there is no matching catalog entry, return null values */ + if (!var_is_valid) + { + nulls[1] = true; + nulls[2] = true; + nulls[4] = true; + values[5] = BoolGetDatum(true); + nulls[6] = true; + nulls[7] = true; + } + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + } + + return (Datum) 0; +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index da772ff9e178..0662f0d68914 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -12589,4 +12589,12 @@ proargnames => '{pid,io_id,io_generation,state,operation,off,length,target,handle_data_len,raw_result,result,target_desc,f_sync,f_localmem,f_buffered}', prosrc => 'pg_get_aios' }, +# Session variables support +{ oid => '8488', descr => 'list of used session variables', + proname => 'pg_session_variables', prorows => '1000', proretset => 't', + provolatile => 's', proparallel => 'r', prorettype => 'record', + proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}', + proargmodes => '{o,o,o,o,o,o,o,o}', + proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}', + prosrc => 'pg_session_variables' }, ] From 00af05b52b486190ad85e6e13e39387195f36f99 Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Sun, 28 Jan 2024 20:54:20 +0100 Subject: [PATCH 4/8] DISCARD VARIABLES Implementation of DISCARD VARIABLES commands by removing hash table with session variables and resetting related memory context. --- doc/src/sgml/ref/discard.sgml | 13 +++- src/backend/commands/discard.c | 6 ++ src/backend/commands/session_variable.c | 28 ++++++++- src/backend/parser/gram.y | 6 ++ src/backend/tcop/utility.c | 3 + src/bin/psql/tab-complete.in.c | 2 +- src/include/commands/session_variable.h | 2 + src/include/nodes/parsenodes.h | 1 + src/include/tcop/cmdtaglist.h | 1 + .../regress/expected/session_variables.out | 63 +++++++++++++++++++ src/test/regress/sql/session_variables.sql | 36 +++++++++++ 11 files changed, 158 insertions(+), 3 deletions(-) diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml index bf44c523cac6..61b967f9c9b7 100644 --- a/doc/src/sgml/ref/discard.sgml +++ b/doc/src/sgml/ref/discard.sgml @@ -21,7 +21,7 @@ PostgreSQL documentation -DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP } +DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES } @@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP } + + VARIABLES + + + Resets the value of all session variables. If a variable + is later reused, it is re-initialized to NULL. + + + + TEMPORARY or TEMP @@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all(); DISCARD PLANS; DISCARD TEMP; DISCARD SEQUENCES; +DISCARD VARIABLES; diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c index 81339a75a528..5904a6c49171 100644 --- a/src/backend/commands/discard.c +++ b/src/backend/commands/discard.c @@ -18,6 +18,7 @@ #include "commands/async.h" #include "commands/discard.h" #include "commands/prepare.h" +#include "commands/session_variable.h" #include "commands/sequence.h" #include "utils/guc.h" #include "utils/portal.h" @@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel) ResetTempTableNamespace(); break; + case DISCARD_VARIABLES: + ResetSessionVariables(); + break; + default: elog(ERROR, "unrecognized DISCARD target: %d", stmt->target); } @@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel) ResetPlanCache(); ResetTempTableNamespace(); ResetSequenceCaches(); + ResetSessionVariables(); } diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c index fa16f47072ef..e1c86966998d 100644 --- a/src/backend/commands/session_variable.c +++ b/src/backend/commands/session_variable.c @@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue) elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue); - Assert(sessionvars); + /* + * There is no guarantee of session variables being initialized, even when + * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ] + * destroys the hash table entirely. + */ + if (!sessionvars) + return; /* * If the hashvalue is not specified, we have to recheck all currently @@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS) return (Datum) 0; } + +/* + * Fast drop of the complete content of the session variables hash table, and + * cleanup of any list that wouldn't be relevant anymore. + * This is used by the DISCARD VARIABLES (and DISCARD ALL) command. + */ +void +ResetSessionVariables(void) +{ + /* destroy hash table and reset related memory context */ + if (sessionvars) + { + hash_destroy(sessionvars); + sessionvars = NULL; + } + + /* release memory allocated by session variables */ + if (SVariableMemoryContext != NULL) + MemoryContextReset(SVariableMemoryContext); +} diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 99fac3411da2..1074d62b7dbc 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -2084,7 +2084,13 @@ DiscardStmt: n->target = DISCARD_SEQUENCES; $$ = (Node *) n; } + | DISCARD VARIABLES + { + DiscardStmt *n = makeNode(DiscardStmt); + n->target = DISCARD_VARIABLES; + $$ = (Node *) n; + } ; diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c index 7a508a3644fe..6e4d2310f5c1 100644 --- a/src/backend/tcop/utility.c +++ b/src/backend/tcop/utility.c @@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree) case DISCARD_SEQUENCES: tag = CMDTAG_DISCARD_SEQUENCES; break; + case DISCARD_VARIABLES: + tag = CMDTAG_DISCARD_VARIABLES; + break; default: tag = CMDTAG_UNKNOWN; } diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c index 78b130c04b0a..9a6d3248f1ca 100644 --- a/src/bin/psql/tab-complete.in.c +++ b/src/bin/psql/tab-complete.in.c @@ -4146,7 +4146,7 @@ match_previous_words(int pattern_id, /* DISCARD */ else if (Matches("DISCARD")) - COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP"); + COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES"); /* DO */ else if (Matches("DO")) diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h index 2391b9ad4438..a8ca43c87af7 100644 --- a/src/include/commands/session_variable.h +++ b/src/include/commands/session_variable.h @@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull); extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params, QueryEnvironment *queryEnv, QueryCompletion *qc); +extern void ResetSessionVariables(void); + #endif diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 8f874a08d295..321235c64914 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -4056,6 +4056,7 @@ typedef enum DiscardMode DISCARD_PLANS, DISCARD_SEQUENCES, DISCARD_TEMP, + DISCARD_VARIABLES, } DiscardMode; typedef struct DiscardStmt diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h index 22082c30008b..bef0ac253314 100644 --- a/src/include/tcop/cmdtaglist.h +++ b/src/include/tcop/cmdtaglist.h @@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false) PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false) PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false) PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false) +PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false) PG_CMDTAG(CMDTAG_DO, "DO", false, false, false) PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false) PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false) diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out index f22467186e3e..79ac40768f8e 100644 --- a/src/test/regress/expected/session_variables.out +++ b/src/test/regress/expected/session_variables.out @@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b; DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME"; DROP SCHEMA :"DBNAME"; RESET search_path; +-- memory cleaning by DISCARD command +CREATE VARIABLE var1 AS varchar; +LET var1 = 'Hello'; +SELECT var1; + var1 +------- + Hello +(1 row) + +DISCARD ALL; +SELECT var1; + var1 +------ + +(1 row) + +LET var1 = 'AHOJ'; +SELECT var1; + var1 +------ + AHOJ +(1 row) + +DISCARD VARIABLES; +SELECT var1; + var1 +------ + +(1 row) + +DROP VARIABLE var1; +-- initial test of debug pg_session_variables function +-- should be zero now +DISCARD VARIABLES; +SELECT count(*) FROM pg_session_variables(); + count +------- + 0 +(1 row) + +CREATE VARIABLE var1 AS varchar; +-- should be zero still +SELECT count(*) FROM pg_session_variables(); + count +------- + 0 +(1 row) + +LET var1 = 'AHOJ'; +SELECT name, typname, can_select, can_update FROM pg_session_variables(); + name | typname | can_select | can_update +------+-------------------+------------+------------ + var1 | character varying | t | t +(1 row) + +DISCARD VARIABLES; +-- should be zero again +SELECT count(*) FROM pg_session_variables(); + count +------- + 0 +(1 row) + diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql index e72360d5254b..2954759aaed1 100644 --- a/src/test/regress/sql/session_variables.sql +++ b/src/test/regress/sql/session_variables.sql @@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME"; DROP SCHEMA :"DBNAME"; RESET search_path; + +-- memory cleaning by DISCARD command +CREATE VARIABLE var1 AS varchar; +LET var1 = 'Hello'; +SELECT var1; + +DISCARD ALL; +SELECT var1; + +LET var1 = 'AHOJ'; +SELECT var1; + +DISCARD VARIABLES; +SELECT var1; + +DROP VARIABLE var1; + +-- initial test of debug pg_session_variables function +-- should be zero now +DISCARD VARIABLES; + +SELECT count(*) FROM pg_session_variables(); + +CREATE VARIABLE var1 AS varchar; + +-- should be zero still +SELECT count(*) FROM pg_session_variables(); + +LET var1 = 'AHOJ'; + +SELECT name, typname, can_select, can_update FROM pg_session_variables(); + +DISCARD VARIABLES; + +-- should be zero again +SELECT count(*) FROM pg_session_variables(); From 09869a070faf9777458749ecd9a2b5bb8218ff63 Mon Sep 17 00:00:00 2001 From: Laurenz Albe Date: Wed, 13 Nov 2024 09:31:28 +0100 Subject: [PATCH 5/8] memory cleaning after DROP VARIABLE Accepting a sinval message invalidates entries in the "sessionvars" hash table. These entries are validated before any read or write operations on session variables. When the entry cannot be validated, it is removed. Removal will be delayed when the variable was dropped by the current transaction, which could still be rolled back. --- src/backend/catalog/pg_variable.c | 7 +- src/backend/commands/session_variable.c | 153 +++++++++++- src/include/commands/session_variable.h | 2 + .../isolation/expected/session-variable.out | 110 +++++++++ src/test/isolation/isolation_schedule | 1 + .../isolation/specs/session-variable.spec | 50 ++++ .../regress/expected/session_variables.out | 217 ++++++++++++++++++ src/test/regress/sql/session_variables.sql | 120 ++++++++++ 8 files changed, 655 insertions(+), 5 deletions(-) create mode 100644 src/test/isolation/expected/session-variable.out create mode 100644 src/test/isolation/specs/session-variable.spec diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c index bb445e9434b9..d672d2a9cb34 100644 --- a/src/backend/catalog/pg_variable.c +++ b/src/backend/catalog/pg_variable.c @@ -22,6 +22,7 @@ #include "catalog/pg_collation.h" #include "catalog/pg_namespace.h" #include "catalog/pg_variable.h" +#include "commands/session_variable.h" #include "miscadmin.h" #include "parser/parse_type.h" #include "utils/builtins.h" @@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt) } /* - * Drop variable by OID + * Drop variable by OID, and register the needed session variable + * cleanup. */ void DropVariableById(Oid varid) @@ -250,4 +252,7 @@ DropVariableById(Oid varid) ReleaseSysCache(tup); table_close(rel, RowExclusiveLock); + + /* do the necessary cleanup in local memory, if needed */ + SessionVariableDropPostprocess(varid); } diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c index e1c86966998d..1596d94fb038 100644 --- a/src/backend/commands/session_variable.c +++ b/src/backend/commands/session_variable.c @@ -14,6 +14,7 @@ */ #include "postgres.h" +#include "access/xact.h" #include "catalog/pg_variable.h" #include "commands/session_variable.h" #include "executor/svariableReceiver.h" @@ -67,6 +68,14 @@ typedef struct SVariableData void *domain_check_extra; LocalTransactionId domain_check_extra_lxid; + /* + * Top level local transaction id of the last transaction that dropped the + * variable, if any. We need this information to avoid freeing memory for + * variables dropped by the local backend, in case the operation is rolled + * back. + */ + LocalTransactionId drop_lxid; + /* * Stored value and type description can be outdated when we receive a * sinval message. We then have to check if the stored data are still @@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */ static MemoryContext SVariableMemoryContext = NULL; +/* becomes true when we receive a sinval message */ +static bool needs_validation = false; + +/* + * The content of dropped session variables is not removed immediately. We do + * that in the next transaction that reads or writes a session variable. + * "validated_lxid" stores the transaction that performed said validation, so + * that we can avoid repeating the effort. + */ +static LocalTransactionId validated_lxid = InvalidLocalTransactionId; + /* * Callback function for session variable invalidation. */ @@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue) if (hashvalue == 0 || svar->hashvalue == hashvalue) { svar->is_valid = false; + needs_validation = true; + } + } +} + +/* + * Handle the local memory cleanup for a DROP VARIABLE command. + * + * Caller should take care of removing the pg_variable entry first. + */ +void +SessionVariableDropPostprocess(Oid varid) +{ + Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid)); + + if (sessionvars) + { + bool found; + SVariable svar = (SVariable) hash_search(sessionvars, &varid, + HASH_FIND, &found); + + if (found) + { + /* + * Save the current top level local transaction id to make sure we + * won't automatically remove the local variable storage in + * validate_all_session_variables() when the invalidation message + * from DROP VARIABLE arrives. After all, the transaction could + * still be rolled back. + */ + svar->is_valid = false; + svar->drop_lxid = MyProc->vxid.lxid; } } } @@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar) return result; } +/* + * Check all potentially invalid session variable data in local memory and free + * the memory for all invalid ones. This function is called before any read or + * write of a session variable. Freeing of a variable's memory is postponed if + * the variable has been dropped by the current transaction, since that + * operation could still be rolled back. + * + * It is possible that we receive a cache invalidation message while + * remove_invalid_session_variables() is executing, so we cannot guarantee that + * all entries in "sessionvars" will be set to "is_valid" after the function is + * done. However, we can guarantee that all entries get checked once. + */ +static void +remove_invalid_session_variables(void) +{ + HASH_SEQ_STATUS status; + SVariable svar; + + /* + * The validation requires system catalog access, so the session state + * should be "in transaction". + */ + Assert(IsTransactionState()); + + if (!needs_validation || !sessionvars) + return; + + /* + * Reset the flag before we start the validation. It can be set again + * by concurrently incoming sinval messages. + */ + needs_validation = false; + + elog(DEBUG1, "effective call of validate_all_session_variables()"); + + hash_seq_init(&status, sessionvars); + while ((svar = (SVariable) hash_seq_search(&status)) != NULL) + { + if (!svar->is_valid) + { + if (svar->drop_lxid == MyProc->vxid.lxid) + { + /* try again in the next transaction */ + needs_validation = true; + continue; + } + + if (!is_session_variable_valid(svar)) + { + Oid varid = svar->varid; + + free_session_variable_value(svar); + hash_search(sessionvars, &varid, HASH_REMOVE, NULL); + svar = NULL; + } + else + svar->is_valid = true; + } + } +} + /* * Initialize attributes cached in "svar" */ @@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid) svar->domain_check_extra = NULL; svar->domain_check_extra_lxid = InvalidLocalTransactionId; + svar->drop_lxid = InvalidTransactionId; + svar->isnull = true; svar->value = (Datum) 0; @@ -319,22 +434,42 @@ get_session_variable(Oid varid) if (!sessionvars) create_sessionvars_hashtables(); + if (validated_lxid == InvalidLocalTransactionId || + validated_lxid != MyProc->vxid.lxid) + { + /* free the memory from dropped session variables */ + remove_invalid_session_variables(); + + /* don't repeat the above step in the same transaction */ + validated_lxid = MyProc->vxid.lxid; + } + svar = (SVariable) hash_search(sessionvars, &varid, HASH_ENTER, &found); if (found) { + /* + * The session variable could have been dropped by a DROP VARIABLE + * statement in a subtransaction that was later rolled back, which + * means that we may have to work with the data of a variable marked + * as invalid. + */ if (!svar->is_valid) { /* - * If there was an invalidation message, the variable might still be - * valid, but we have to check with the system catalog. + * We have to check the system catalog to see if the variable is + * still valid, even if an invalidation message set it to invalid. + * + * The variable must be validated before it is accessed. The oid + * should be valid, because the related session variable is already + * locked, and remove_invalid_session_variables() would remove + * variables dropped by other transactions. */ if (is_session_variable_valid(svar)) svar->is_valid = true; else - /* if the value cannot be validated, we have to discard it */ - free_session_variable_value(svar); + elog(ERROR, "unexpected state of session variable %u", varid); } } else @@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull) if (!sessionvars) create_sessionvars_hashtables(); + if (validated_lxid == InvalidLocalTransactionId || + validated_lxid != MyProc->vxid.lxid) + { + /* free the memory from dropped session variables */ + remove_invalid_session_variables(); + + /* don't repeat the above step in the same transaction */ + validated_lxid = MyProc->vxid.lxid; + } + svar = (SVariable) hash_search(sessionvars, &varid, HASH_ENTER, &found); diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h index a8ca43c87af7..d3cc79b56089 100644 --- a/src/include/commands/session_variable.h +++ b/src/include/commands/session_variable.h @@ -21,6 +21,8 @@ #include "tcop/cmdtag.h" #include "utils/queryenvironment.h" +extern void SessionVariableDropPostprocess(Oid varid); + extern void SetSessionVariable(Oid varid, Datum value, bool isNull); extern Datum GetSessionVariable(Oid varid, bool *isNull); diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out new file mode 100644 index 000000000000..0a5579dc7cef --- /dev/null +++ b/src/test/isolation/expected/session-variable.out @@ -0,0 +1,110 @@ +Parsed test spec with 4 sessions + +starting permutation: let val drop val +step let: LET myvar = 'test'; +step val: SELECT myvar; +myvar +----- +test +(1 row) + +step drop: DROP VARIABLE myvar; +step val: SELECT myvar; +ERROR: column "myvar" does not exist + +starting permutation: let val s1 drop val sr1 +step let: LET myvar = 'test'; +step val: SELECT myvar; +myvar +----- +test +(1 row) + +step s1: BEGIN; +step drop: DROP VARIABLE myvar; +step val: SELECT myvar; +ERROR: column "myvar" does not exist +step sr1: ROLLBACK; + +starting permutation: let val dbg drop create dbg val +step let: LET myvar = 'test'; +step val: SELECT myvar; +myvar +----- +test +(1 row) + +step dbg: SELECT schema, name, removed FROM pg_session_variables(); +schema|name |removed +------+-----+------- +public|myvar|f +(1 row) + +step drop: DROP VARIABLE myvar; +step create: CREATE VARIABLE myvar AS text; +step dbg: SELECT schema, name, removed FROM pg_session_variables(); +schema|name|removed +------+----+------- + | |t +(1 row) + +step val: SELECT myvar; +myvar +----- + +(1 row) + + +starting permutation: let val s1 dbg drop create dbg val sr1 +step let: LET myvar = 'test'; +step val: SELECT myvar; +myvar +----- +test +(1 row) + +step s1: BEGIN; +step dbg: SELECT schema, name, removed FROM pg_session_variables(); +schema|name |removed +------+-----+------- +public|myvar|f +(1 row) + +step drop: DROP VARIABLE myvar; +step create: CREATE VARIABLE myvar AS text; +step dbg: SELECT schema, name, removed FROM pg_session_variables(); +schema|name |removed +------+-----+------- +public|myvar|f +(1 row) + +step val: SELECT myvar; +myvar +----- + +(1 row) + +step sr1: ROLLBACK; + +starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state +step create3: CREATE VARIABLE myvar3 AS text; +step let3: LET myvar3 = 'test'; +step s3: BEGIN; +step create4: CREATE VARIABLE myvar4 AS text; +step let4: LET myvar4 = 'test'; +step drop4: DROP VARIABLE myvar4; +step drop3: DROP VARIABLE myvar3; +step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table; +?column? +-------- +t +(1 row) + +step discard: DISCARD VARIABLES; +step sc3: COMMIT; +step state: SELECT varname FROM pg_variable; +varname +------- +myvar +(1 row) + diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule index e3c669a29c7a..8df901fc79c5 100644 --- a/src/test/isolation/isolation_schedule +++ b/src/test/isolation/isolation_schedule @@ -116,3 +116,4 @@ test: serializable-parallel-2 test: serializable-parallel-3 test: matview-write-skew test: lock-nowait +test: session-variable diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec new file mode 100644 index 000000000000..c864fee40065 --- /dev/null +++ b/src/test/isolation/specs/session-variable.spec @@ -0,0 +1,50 @@ +# Test session variables memory cleanup for sinval + +setup +{ + CREATE VARIABLE myvar AS text; +} + +teardown +{ + DROP VARIABLE IF EXISTS myvar; +} + +session s1 +step s1 { BEGIN; } +step let { LET myvar = 'test'; } +step val { SELECT myvar; } +step dbg { SELECT schema, name, removed FROM pg_session_variables(); } +step sr1 { ROLLBACK; } + +session s2 +step drop { DROP VARIABLE myvar; } +step create { CREATE VARIABLE myvar AS text; } + +session s3 +step s3 { BEGIN; } +step let3 { LET myvar3 = 'test'; } +step create4 { CREATE VARIABLE myvar4 AS text; } +step let4 { LET myvar4 = 'test'; } +step drop4 { DROP VARIABLE myvar4; } +step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; } +step discard { DISCARD VARIABLES; } +step sc3 { COMMIT; } +step state { SELECT varname FROM pg_variable; } + +session s4 +step create3 { CREATE VARIABLE myvar3 AS text; } +step drop3 { DROP VARIABLE myvar3; } + +# Concurrent drop of a known variable should lead to an error +permutation let val drop val +# Same, but with an explicit transaction +permutation let val s1 drop val sr1 +# Concurrent drop/create of a known variable should lead to empty variable +permutation let val dbg drop create dbg val +# Concurrent drop/create of a known variable should lead to empty variable +# We need a transaction to make sure that we won't accept invalidation when +# calling the dbg step after the concurrent drop +permutation let val s1 dbg drop create dbg val sr1 +# test for DISCARD ALL when all internal queues have actions registered +permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out index 79ac40768f8e..2783caa8446d 100644 --- a/src/test/regress/expected/session_variables.out +++ b/src/test/regress/expected/session_variables.out @@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables(); 0 (1 row) +-- dropped variables should be removed from memory before the next usage +-- of any session variable in the next transaction +LET var1 = 'Ahoj'; +SELECT name, typname, can_select, can_update FROM pg_session_variables(); + name | typname | can_select | can_update +------+-------------------+------------+------------ + var1 | character varying | t | t +(1 row) + +DROP VARIABLE var1; +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + count +------- + 0 +(1 row) + +-- the content of the value should be preserved when a variable is dropped +-- by an aborted transaction +CREATE VARIABLE var1 AS varchar; +LET var1 = 'Ahoj'; +BEGIN; +DROP VARIABLE var1; +-- should fail +SELECT var1; +ERROR: column "var1" does not exist +LINE 1: SELECT var1; + ^ +ROLLBACK; +-- should be ok +SELECT var1; + var1 +------ + Ahoj +(1 row) + +-- another test +BEGIN; +DROP VARIABLE var1; +CREATE VARIABLE var1 AS int; +LET var1 = 100; +-- should be ok, result 100 +SELECT var1; + var1 +------ + 100 +(1 row) + +ROLLBACK; +-- should be ok, result 'Ahoj' +SELECT var1; + var1 +------ + Ahoj +(1 row) + +DROP VARIABLE var1; +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + count +------- + 0 +(1 row) + +BEGIN; + CREATE VARIABLE var1 AS int; + LET var1 = 100; + SELECT var1; + var1 +------ + 100 +(1 row) + + SELECT name, typname, can_select, can_update FROM pg_session_variables(); + name | typname | can_select | can_update +------+---------+------------+------------ + var1 | integer | t | t +(1 row) + + DROP VARIABLE var1; +COMMIT; +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + count +------- + 0 +(1 row) + +BEGIN; + CREATE VARIABLE var1 AS int; + LET var1 = 100; + SELECT var1; + var1 +------ + 100 +(1 row) + + SELECT name, typname, can_select, can_update FROM pg_session_variables(); + name | typname | can_select | can_update +------+---------+------------+------------ + var1 | integer | t | t +(1 row) + + DROP VARIABLE var1; +COMMIT; +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + count +------- + 0 +(1 row) + +CREATE VARIABLE var1 AS int; +CREATE VARIABLE var2 AS int; +LET var1 = 10; +LET var2 = 0; +BEGIN; + SAVEPOINT s1; + DROP VARIABLE var1; + -- force cleaning by touching another session variable + SELECT var2; + var2 +------ + 0 +(1 row) + + ROLLBACK TO s1; + SAVEPOINT s2; + DROP VARIABLE var1; + SELECT var2; + var2 +------ + 0 +(1 row) + + ROLLBACK TO s2; +COMMIT; +-- should be ok +SELECT var1; + var1 +------ + 10 +(1 row) + +BEGIN; + SAVEPOINT s1; + DROP VARIABLE var1; + -- force cleaning by touching another session variable + SELECT var2; + var2 +------ + 0 +(1 row) + + ROLLBACK TO s1; + SAVEPOINT s2; + DROP VARIABLE var1; + SELECT var2; + var2 +------ + 0 +(1 row) + +ROLLBACK; +-- should be ok +SELECT var1; + var1 +------ + 10 +(1 row) + +BEGIN; + SAVEPOINT s1; + DROP VARIABLE var1; + -- force cleaning by touching another session variable + SELECT var2; + var2 +------ + 0 +(1 row) + + SAVEPOINT s2; + -- force cleaning by touching another session variable + SELECT var2; + var2 +------ + 0 +(1 row) + + ROLLBACK TO s1; + -- force cleaning by touching another session variable + SELECT var2; + var2 +------ + 0 +(1 row) + +COMMIT; +-- should be ok +SELECT var1; + var1 +------ + 10 +(1 row) + +-- repeated aborted transaction +BEGIN; DROP VARIABLE var1; ROLLBACK; +BEGIN; DROP VARIABLE var1; ROLLBACK; +BEGIN; DROP VARIABLE var1; ROLLBACK; +-- should be ok +SELECT var1; + var1 +------ + 10 +(1 row) + +DROP VARIABLE var1, var2; diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql index 2954759aaed1..a624ab8b67fe 100644 --- a/src/test/regress/sql/session_variables.sql +++ b/src/test/regress/sql/session_variables.sql @@ -1214,3 +1214,123 @@ DISCARD VARIABLES; -- should be zero again SELECT count(*) FROM pg_session_variables(); + +-- dropped variables should be removed from memory before the next usage +-- of any session variable in the next transaction + +LET var1 = 'Ahoj'; +SELECT name, typname, can_select, can_update FROM pg_session_variables(); +DROP VARIABLE var1; + +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + +-- the content of the value should be preserved when a variable is dropped +-- by an aborted transaction +CREATE VARIABLE var1 AS varchar; +LET var1 = 'Ahoj'; +BEGIN; +DROP VARIABLE var1; + +-- should fail +SELECT var1; + +ROLLBACK; + +-- should be ok +SELECT var1; + +-- another test +BEGIN; +DROP VARIABLE var1; +CREATE VARIABLE var1 AS int; +LET var1 = 100; +-- should be ok, result 100 +SELECT var1; +ROLLBACK; +-- should be ok, result 'Ahoj' +SELECT var1; + +DROP VARIABLE var1; + +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + +BEGIN; + CREATE VARIABLE var1 AS int; + LET var1 = 100; + SELECT var1; + SELECT name, typname, can_select, can_update FROM pg_session_variables(); + DROP VARIABLE var1; +COMMIT; + +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + +BEGIN; + CREATE VARIABLE var1 AS int; + LET var1 = 100; + SELECT var1; + SELECT name, typname, can_select, can_update FROM pg_session_variables(); + DROP VARIABLE var1; +COMMIT; + +-- should be zero +SELECT count(*) FROM pg_session_variables() WHERE NOT removed; + +CREATE VARIABLE var1 AS int; +CREATE VARIABLE var2 AS int; +LET var1 = 10; +LET var2 = 0; +BEGIN; + SAVEPOINT s1; + DROP VARIABLE var1; + -- force cleaning by touching another session variable + SELECT var2; + ROLLBACK TO s1; + SAVEPOINT s2; + DROP VARIABLE var1; + SELECT var2; + ROLLBACK TO s2; +COMMIT; +-- should be ok +SELECT var1; + +BEGIN; + SAVEPOINT s1; + DROP VARIABLE var1; + -- force cleaning by touching another session variable + SELECT var2; + ROLLBACK TO s1; + SAVEPOINT s2; + DROP VARIABLE var1; + SELECT var2; +ROLLBACK; +-- should be ok +SELECT var1; + +BEGIN; + SAVEPOINT s1; + DROP VARIABLE var1; + -- force cleaning by touching another session variable + SELECT var2; + + SAVEPOINT s2; + -- force cleaning by touching another session variable + SELECT var2; + ROLLBACK TO s1; + -- force cleaning by touching another session variable + SELECT var2; +COMMIT; +-- should be ok +SELECT var1; + +-- repeated aborted transaction +BEGIN; DROP VARIABLE var1; ROLLBACK; +BEGIN; DROP VARIABLE var1; ROLLBACK; +BEGIN; DROP VARIABLE var1; ROLLBACK; + +-- should be ok +SELECT var1; + +DROP VARIABLE var1, var2; From 308fccf09540a396cbf79a0721a38f7d5e77d9c8 Mon Sep 17 00:00:00 2001 From: Laurenz Albe Date: Wed, 13 Nov 2024 14:06:06 +0100 Subject: [PATCH 6/8] plpgsql tests --- src/pl/plpgsql/src/Makefile | 3 +- .../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++ src/pl/plpgsql/src/meson.build | 1 + .../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++ 4 files changed, 674 insertions(+), 1 deletion(-) create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile index 63cb96fae3ef..bbcae27d422d 100644 --- a/src/pl/plpgsql/src/Makefile +++ b/src/pl/plpgsql/src/Makefile @@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB) REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \ plpgsql_copy plpgsql_domain plpgsql_misc \ plpgsql_record plpgsql_simple plpgsql_transaction \ - plpgsql_trap plpgsql_trigger plpgsql_varprops + plpgsql_trap plpgsql_trigger plpgsql_varprops \ + plpgsql_session_variable # where to find gen_keywordlist.pl and subsidiary files TOOLSDIR = $(top_srcdir)/src/tools diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out new file mode 100644 index 000000000000..ab7799005969 --- /dev/null +++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out @@ -0,0 +1,382 @@ +-- test of session variables +CREATE VARIABLE plpgsql_sv_var AS numeric; +LET plpgsql_sv_var = pi(); +-- passing parameters to DO block +DO $$ +BEGIN + RAISE NOTICE 'value of session variable is %', plpgsql_sv_var; +END; +$$; +NOTICE: value of session variable is 3.14159265358979 +-- passing output from DO block; +DO $$ +BEGIN + LET plpgsql_sv_var = 2 * pi(); +END +$$; +SELECT plpgsql_sv_var AS "pi_multiply_2"; + pi_multiply_2 +------------------ + 6.28318530717959 +(1 row) + +DROP VARIABLE plpgsql_sv_var; +-- test access from PL/pgSQL +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS numeric; +CREATE VARIABLE plpgsql_sv_var3 AS varchar; +CREATE OR REPLACE FUNCTION writer_func() +RETURNS void AS $$ +BEGIN + LET plpgsql_sv_var1 = 10; + LET plpgsql_sv_var2 = pi(); + -- very long value + LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000)); +END; +$$ LANGUAGE plpgsql; +CREATE OR REPLACE FUNCTION updater_func() +RETURNS void AS $$ +BEGIN + LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100; + LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000; + -- very long value + LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000)); +END; +$$ LANGUAGE plpgsql; +CREATE OR REPLACE FUNCTION reader_func() +RETURNS void AS $$ +BEGIN + RAISE NOTICE 'var1 = %', plpgsql_sv_var1; + RAISE NOTICE 'var2 = %', plpgsql_sv_var2; + RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3); +END; +$$ LANGUAGE plpgsql; +-- execute in a transaction +BEGIN; +SELECT writer_func(); + writer_func +------------- + +(1 row) + +SELECT reader_func(); +NOTICE: var1 = 10 +NOTICE: var2 = 3.14159265358979 +NOTICE: length of var3 = 10002 + reader_func +------------- + +(1 row) + +SELECT updater_func(); + updater_func +-------------- + +(1 row) + +SELECT reader_func(); +NOTICE: var1 = 110 +NOTICE: var2 = 100000000003.14159265358979 +NOTICE: length of var3 = 20004 + reader_func +------------- + +(1 row) + +END; +-- execute outside of a transaction +SELECT writer_func(); + writer_func +------------- + +(1 row) + +SELECT reader_func(); +NOTICE: var1 = 10 +NOTICE: var2 = 3.14159265358979 +NOTICE: length of var3 = 10002 + reader_func +------------- + +(1 row) + +SELECT updater_func(); + updater_func +-------------- + +(1 row) + +SELECT reader_func(); +NOTICE: var1 = 110 +NOTICE: var2 = 100000000003.14159265358979 +NOTICE: length of var3 = 20004 + reader_func +------------- + +(1 row) + +-- execute inside a PL/pgSQL block +DO $$ +BEGIN + PERFORM writer_func(); + PERFORM reader_func(); + PERFORM updater_func(); + PERFORM reader_func(); +END; +$$; +NOTICE: var1 = 10 +NOTICE: var2 = 3.14159265358979 +NOTICE: length of var3 = 10002 +NOTICE: var1 = 110 +NOTICE: var2 = 100000000003.14159265358979 +NOTICE: length of var3 = 20004 +-- plan caches should be correctly invalidated +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3; +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS numeric; +CREATE VARIABLE plpgsql_sv_var3 AS varchar; +-- should work again +DO $$ +BEGIN + PERFORM writer_func(); + PERFORM reader_func(); + PERFORM updater_func(); + PERFORM reader_func(); +END; +$$; +NOTICE: var1 = 10 +NOTICE: var2 = 3.14159265358979 +NOTICE: length of var3 = 10002 +NOTICE: var1 = 110 +NOTICE: var2 = 100000000003.14159265358979 +NOTICE: length of var3 = 20004 +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3; +DROP FUNCTION writer_func; +DROP FUNCTION reader_func; +DROP FUNCTION updater_func; +-- another check of correct plan cache invalidation +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS int[]; +CREATE OR REPLACE FUNCTION test_func() +RETURNS void AS $$ +DECLARE v int[] DEFAULT '{}'; +BEGIN + LET plpgsql_sv_var1 = 1; + v[plpgsql_sv_var1] = 100; + RAISE NOTICE '%', v; + LET plpgsql_sv_var2 = v; + LET plpgsql_sv_var2[plpgsql_sv_var1] = -1; + RAISE NOTICE '%', plpgsql_sv_var2; +END; +$$ LANGUAGE plpgsql; +SELECT test_func(); +NOTICE: {100} +NOTICE: {-1} + test_func +----------- + +(1 row) + +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2; +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS int[]; +SELECT test_func(); +NOTICE: {100} +NOTICE: {-1} + test_func +----------- + +(1 row) + +DROP FUNCTION test_func(); +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2; +-- check secure access +CREATE ROLE regress_var_owner_role; +CREATE ROLE regress_var_reader_role; +CREATE ROLE regress_var_exec_role; +GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role; +SET ROLE TO regress_var_owner_role; +CREATE VARIABLE plpgsql_sv_var1 AS int; +LET plpgsql_sv_var1 = 10; +SET ROLE TO DEFAULT; +SET ROLE TO regress_var_reader_role; +CREATE OR REPLACE FUNCTION var_read_func() +RETURNS void AS $$ +BEGIN + RAISE NOTICE '%', plpgsql_sv_var1; +END; +$$ LANGUAGE plpgsql SECURITY DEFINER; +SET ROLE TO DEFAULT; +SET ROLE TO regress_var_exec_role; +-- should fail +SELECT var_read_func(); +ERROR: permission denied for session variable plpgsql_sv_var1 +CONTEXT: PL/pgSQL expression "plpgsql_sv_var1" +PL/pgSQL function var_read_func() line 3 at RAISE +SET ROLE TO DEFAULT; +SET ROLE TO regress_var_owner_role; +GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role; +SET ROLE TO DEFAULT; +SET ROLE TO regress_var_exec_role; +-- should be ok +SELECT var_read_func(); +NOTICE: 10 + var_read_func +--------------- + +(1 row) + +SET ROLE TO DEFAULT; +SET ROLE TO regress_var_owner_role; +DROP VARIABLE plpgsql_sv_var1; +SET ROLE TO DEFAULT; +SET ROLE TO regress_var_exec_role; +-- should fail, but not crash +SELECT var_read_func(); +ERROR: column "plpgsql_sv_var1" does not exist +LINE 1: plpgsql_sv_var1 + ^ +QUERY: plpgsql_sv_var1 +CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE +SET ROLE TO DEFAULT; +DROP FUNCTION var_read_func; +REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role; +DROP ROLE regress_var_owner_role; +DROP ROLE regress_var_reader_role; +DROP ROLE regress_var_exec_role; +-- returns updated value +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE OR REPLACE FUNCTION inc_var_int(int) +RETURNS int AS $$ +BEGIN + LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1); + RETURN plpgsql_sv_var1; +END; +$$ LANGUAGE plpgsql; +SELECT inc_var_int(1); + inc_var_int +------------- + 1 +(1 row) + +SELECT inc_var_int(1); + inc_var_int +------------- + 2 +(1 row) + +SELECT inc_var_int(1); + inc_var_int +------------- + 3 +(1 row) + +SELECT inc_var_int(1) FROM generate_series(1,10); + inc_var_int +------------- + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 +(10 rows) + +CREATE VARIABLE plpgsql_sv_var2 AS numeric; +LET plpgsql_sv_var2 = 0.0; +CREATE OR REPLACE FUNCTION inc_var_num(numeric) +RETURNS int AS $$ +BEGIN + LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1); + RETURN plpgsql_sv_var2; +END; +$$ LANGUAGE plpgsql; +SELECT inc_var_num(1.0); + inc_var_num +------------- + 1 +(1 row) + +SELECT inc_var_num(1.0); + inc_var_num +------------- + 2 +(1 row) + +SELECT inc_var_num(1.0); + inc_var_num +------------- + 3 +(1 row) + +SELECT inc_var_num(1.0) FROM generate_series(1,10); + inc_var_num +------------- + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12 + 13 +(10 rows) + +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2; +DROP FUNCTION inc_var_int; +DROP FUNCTION inc_var_num; +-- plpgsql variables are preferred against session variables +CREATE VARIABLE plpgsql_sv_var1 AS int; +DO $$ +<> +DECLARE plpgsql_sv_var1 int; +BEGIN + LET plpgsql_sv_var1 = 100; + + plpgsql_sv_var1 := 1000; + + -- print 100; + RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1; + + -- print 1000 + RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1; + + -- print 1000 + RAISE NOTICE 'variable is %', plpgsql_sv_var1; +END; +$$; +NOTICE: session variable is 100 +NOTICE: plpgsql variable is 1000 +NOTICE: variable is 1000 +DROP VARIABLE plpgsql_sv_var1; +-- the value should not be corrupted +CREATE VARIABLE plpgsql_sv_v text; +LET plpgsql_sv_v = 'abc'; +CREATE FUNCTION ffunc() +RETURNS text AS $$ +BEGIN + RETURN gfunc(plpgsql_sv_v); +END +$$ LANGUAGE plpgsql; +CREATE FUNCTION gfunc(t text) +RETURNS text AS $$ +BEGIN + LET plpgsql_sv_v = 'BOOM!'; + RETURN t; +END; +$$ LANGUAGE plpgsql; +select ffunc(); + ffunc +------- + abc +(1 row) + +DROP FUNCTION ffunc(); +DROP FUNCTION gfunc(text); +DROP VARIABLE plpgsql_sv_v; diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build index 33c49ac25d94..1d01d1c26291 100644 --- a/src/pl/plpgsql/src/meson.build +++ b/src/pl/plpgsql/src/meson.build @@ -88,6 +88,7 @@ tests += { 'plpgsql_trap', 'plpgsql_trigger', 'plpgsql_varprops', + 'plpgsql_session_variable', ], }, } diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql new file mode 100644 index 000000000000..a3cc264cf380 --- /dev/null +++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql @@ -0,0 +1,289 @@ +-- test of session variables +CREATE VARIABLE plpgsql_sv_var AS numeric; + +LET plpgsql_sv_var = pi(); + +-- passing parameters to DO block +DO $$ +BEGIN + RAISE NOTICE 'value of session variable is %', plpgsql_sv_var; +END; +$$; + +-- passing output from DO block; +DO $$ +BEGIN + LET plpgsql_sv_var = 2 * pi(); +END +$$; + +SELECT plpgsql_sv_var AS "pi_multiply_2"; + +DROP VARIABLE plpgsql_sv_var; + +-- test access from PL/pgSQL +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS numeric; +CREATE VARIABLE plpgsql_sv_var3 AS varchar; + +CREATE OR REPLACE FUNCTION writer_func() +RETURNS void AS $$ +BEGIN + LET plpgsql_sv_var1 = 10; + LET plpgsql_sv_var2 = pi(); + -- very long value + LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000)); +END; +$$ LANGUAGE plpgsql; + +CREATE OR REPLACE FUNCTION updater_func() +RETURNS void AS $$ +BEGIN + LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100; + LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000; + -- very long value + LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000)); +END; +$$ LANGUAGE plpgsql; + + +CREATE OR REPLACE FUNCTION reader_func() +RETURNS void AS $$ +BEGIN + RAISE NOTICE 'var1 = %', plpgsql_sv_var1; + RAISE NOTICE 'var2 = %', plpgsql_sv_var2; + RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3); +END; +$$ LANGUAGE plpgsql; + +-- execute in a transaction +BEGIN; +SELECT writer_func(); +SELECT reader_func(); +SELECT updater_func(); +SELECT reader_func(); +END; + +-- execute outside of a transaction +SELECT writer_func(); +SELECT reader_func(); +SELECT updater_func(); +SELECT reader_func(); + +-- execute inside a PL/pgSQL block +DO $$ +BEGIN + PERFORM writer_func(); + PERFORM reader_func(); + PERFORM updater_func(); + PERFORM reader_func(); +END; +$$; + +-- plan caches should be correctly invalidated +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3; + +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS numeric; +CREATE VARIABLE plpgsql_sv_var3 AS varchar; + +-- should work again +DO $$ +BEGIN + PERFORM writer_func(); + PERFORM reader_func(); + PERFORM updater_func(); + PERFORM reader_func(); +END; +$$; + +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3; + +DROP FUNCTION writer_func; +DROP FUNCTION reader_func; +DROP FUNCTION updater_func; + +-- another check of correct plan cache invalidation +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS int[]; + +CREATE OR REPLACE FUNCTION test_func() +RETURNS void AS $$ +DECLARE v int[] DEFAULT '{}'; +BEGIN + LET plpgsql_sv_var1 = 1; + v[plpgsql_sv_var1] = 100; + RAISE NOTICE '%', v; + LET plpgsql_sv_var2 = v; + LET plpgsql_sv_var2[plpgsql_sv_var1] = -1; + RAISE NOTICE '%', plpgsql_sv_var2; +END; +$$ LANGUAGE plpgsql; + +SELECT test_func(); + +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2; + +CREATE VARIABLE plpgsql_sv_var1 AS int; +CREATE VARIABLE plpgsql_sv_var2 AS int[]; + +SELECT test_func(); + +DROP FUNCTION test_func(); + +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2; + +-- check secure access +CREATE ROLE regress_var_owner_role; +CREATE ROLE regress_var_reader_role; +CREATE ROLE regress_var_exec_role; + +GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role; + +SET ROLE TO regress_var_owner_role; + +CREATE VARIABLE plpgsql_sv_var1 AS int; +LET plpgsql_sv_var1 = 10; + +SET ROLE TO DEFAULT; + +SET ROLE TO regress_var_reader_role; + +CREATE OR REPLACE FUNCTION var_read_func() +RETURNS void AS $$ +BEGIN + RAISE NOTICE '%', plpgsql_sv_var1; +END; +$$ LANGUAGE plpgsql SECURITY DEFINER; + +SET ROLE TO DEFAULT; + +SET ROLE TO regress_var_exec_role; + +-- should fail +SELECT var_read_func(); + +SET ROLE TO DEFAULT; + +SET ROLE TO regress_var_owner_role; +GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role; + +SET ROLE TO DEFAULT; + +SET ROLE TO regress_var_exec_role; + +-- should be ok +SELECT var_read_func(); + +SET ROLE TO DEFAULT; + +SET ROLE TO regress_var_owner_role; + +DROP VARIABLE plpgsql_sv_var1; + +SET ROLE TO DEFAULT; + +SET ROLE TO regress_var_exec_role; + +-- should fail, but not crash +SELECT var_read_func(); + +SET ROLE TO DEFAULT; + +DROP FUNCTION var_read_func; + +REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role; + +DROP ROLE regress_var_owner_role; +DROP ROLE regress_var_reader_role; +DROP ROLE regress_var_exec_role; + +-- returns updated value +CREATE VARIABLE plpgsql_sv_var1 AS int; + +CREATE OR REPLACE FUNCTION inc_var_int(int) +RETURNS int AS $$ +BEGIN + LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1); + RETURN plpgsql_sv_var1; +END; +$$ LANGUAGE plpgsql; + +SELECT inc_var_int(1); +SELECT inc_var_int(1); +SELECT inc_var_int(1); + +SELECT inc_var_int(1) FROM generate_series(1,10); + +CREATE VARIABLE plpgsql_sv_var2 AS numeric; + +LET plpgsql_sv_var2 = 0.0; + +CREATE OR REPLACE FUNCTION inc_var_num(numeric) +RETURNS int AS $$ +BEGIN + LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1); + RETURN plpgsql_sv_var2; +END; +$$ LANGUAGE plpgsql; + +SELECT inc_var_num(1.0); +SELECT inc_var_num(1.0); +SELECT inc_var_num(1.0); + +SELECT inc_var_num(1.0) FROM generate_series(1,10); + +DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2; + +DROP FUNCTION inc_var_int; +DROP FUNCTION inc_var_num; + +-- plpgsql variables are preferred against session variables +CREATE VARIABLE plpgsql_sv_var1 AS int; + +DO $$ +<> +DECLARE plpgsql_sv_var1 int; +BEGIN + LET plpgsql_sv_var1 = 100; + + plpgsql_sv_var1 := 1000; + + -- print 100; + RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1; + + -- print 1000 + RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1; + + -- print 1000 + RAISE NOTICE 'variable is %', plpgsql_sv_var1; +END; +$$; + +DROP VARIABLE plpgsql_sv_var1; + +-- the value should not be corrupted +CREATE VARIABLE plpgsql_sv_v text; +LET plpgsql_sv_v = 'abc'; + +CREATE FUNCTION ffunc() +RETURNS text AS $$ +BEGIN + RETURN gfunc(plpgsql_sv_v); +END +$$ LANGUAGE plpgsql; + +CREATE FUNCTION gfunc(t text) +RETURNS text AS $$ +BEGIN + LET plpgsql_sv_v = 'BOOM!'; + RETURN t; +END; +$$ LANGUAGE plpgsql; + +select ffunc(); + +DROP FUNCTION ffunc(); +DROP FUNCTION gfunc(text); + +DROP VARIABLE plpgsql_sv_v; From da2b1aaca4d6eb2276ea9e961b5ad5e0bc5f6208 Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Tue, 21 May 2024 17:55:24 +0200 Subject: [PATCH 7/8] GUC session_variables_ambiguity_warning Inside an query the session variables can be shadowed. This behaviour is by design, because this ensuring so new variables doesn't break existing queries. But this behaviour can be confusing, because shadowing is quiet. When new GUC session_variables_ambiguity_warning is on, then the warning is displayed, when some session variable can be used, but it is not used due shadowing. This feature should to help with investigation of unexpected behaviour. Note: PLpgSQL has an option that controls priority of identifier's spaces (SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe this default is the best. I cannot to implement similar very strict behaviour to session variables, because one unhappy named session variable can breaks an applications. The problems related to badly named PLpgSQL's varible is limitted just to only one routine. --- doc/src/sgml/config.sgml | 60 +++++++++++++++++++ doc/src/sgml/ddl.sgml | 11 ++++ src/backend/parser/parse_expr.c | 49 +++++++++++++-- src/backend/utils/misc/guc_tables.c | 9 +++ src/backend/utils/misc/postgresql.conf.sample | 1 + src/include/parser/parse_expr.h | 1 + .../src/expected/plpgsql_session_variable.out | 33 ++++++++++ .../src/sql/plpgsql_session_variable.sql | 29 +++++++++ .../regress/expected/session_variables.out | 26 ++++++++ src/test/regress/sql/session_variables.sql | 26 ++++++++ 10 files changed, 241 insertions(+), 4 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 14661ac2cc63..a984b5fee7ae 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -11372,6 +11372,66 @@ dynamic_library_path = '/usr/local/lib/postgresql:$libdir' + + session_variables_ambiguity_warning (boolean) + + session_variables_ambiguity_warning configuration parameter + + + + + When on, a warning is raised when any identifier in a query could be + used as both a column identifier, routine variable or a session + variable identifier. The default is off. + + + Session variables can be shadowed by column references in a query, this + is an expected behavior. Previously working queries shouldn't error out + by creating any session variable, so session variables are always shadowed + if an identifier is ambiguous. Variables should be referenced using + anunambiguous identifier without any possibility for a collision with + identifier of other database objects (column names or record fields names). + The warning messages emitted when enabling session_variables_ambiguity_warning + can help finding such identifier collision. + +CREATE TABLE foo(a int); +INSERT INTO foo VALUES(10); +CREATE VARIABLE a int; +LET a = 100; +SELECT a FROM foo; + + + + a +---- + 10 +(1 row) + + + +SET session_variables_ambiguity_warning TO on; +SELECT a FROM foo; + + + +WARNING: session variable "a" is shadowed +LINE 1: SELECT a FROM foo; + ^ +DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name. + a +---- + 10 +(1 row) + + + + This feature can significantly increase log size, so it's disabled by + default. For testing or development environments it's recommended to + enable it if you use session variables. + + + + standard_conforming_strings (boolean) stringsstandard conforming diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index b3fc62056e99..3a3f6be79f27 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -5446,6 +5446,17 @@ SELECT name FROM foo; Alice + + + When a query contains identifiers or qualified identifiers that could be + used as both a session variable identifiers and as column identifier, + then the column identifier is preferred every time. Warnings can be + emitted when this situation happens by enabling configuration parameter . User can explicitly + qualify the source object by syntax table.column or + schema.variable. It is strongly recommended to rename + shadowed variables or use qualified names always. + diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 988d1c66f566..b10e1bca3083 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -45,6 +45,7 @@ /* GUC parameters */ bool Transform_null_equals = false; +bool session_variables_ambiguity_warning = false; static Node *transformExprRecurse(ParseState *pstate, Node *expr); @@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) * * SELECT foo.a, foo.b, foo.c FROM foo; * - * However, that is very confusing, so we disallow it. We don't try to - * identify a variable if we know that it would be shadowed. - * ----- + * However, that is very confusing, so we disallow it. + * + * When session_variables_ambiguity_warning is requested, then we + * need to identify a variable although we know, so this variable + * would be shadowed. */ - if (!node && !(relname && crerr == CRERR_NO_COLUMN)) + if (node || (relname && crerr == CRERR_NO_COLUMN)) + { + /* + * In this path we just try (if it is wanted) detect if session + * variable is shadowed. + */ + if (session_variables_ambiguity_warning) + { + /* + * The AccessShareLock is created on related session variable. + * The lock will be kept for the whole transaction. + */ + varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true); + + if (OidIsValid(varid)) + { + /* this path will ending by WARNING. Unlock variable first */ + UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock); + + if (node) + ereport(WARNING, + (errcode(ERRCODE_AMBIGUOUS_COLUMN), + errmsg("session variable \"%s\" is shadowed", + NameListToString(cref->fields)), + errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."), + parser_errposition(pstate, cref->location))); + else + /* session variable is shadowed by RTE */ + ereport(WARNING, + (errcode(ERRCODE_AMBIGUOUS_COLUMN), + errmsg("session variable \"%s.%s\" is shadowed", + get_namespace_name(get_session_variable_namespace(varid)), + get_session_variable_name(varid)), + errdetail("Session variables can be shadowed by tables or table's aliases with the same name."), + parser_errposition(pstate, cref->location))); + } + } + } + else { /* takes an AccessShareLock on the session variable */ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false); diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c index 2f8cbd867599..31d70785b14a 100644 --- a/src/backend/utils/misc/guc_tables.c +++ b/src/backend/utils/misc/guc_tables.c @@ -1644,6 +1644,15 @@ struct config_bool ConfigureNamesBool[] = false, NULL, NULL, NULL }, + { + {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT, + gettext_noop("Raise a warning when reference to a session variable is ambiguous."), + NULL + }, + &session_variables_ambiguity_warning, + false, + NULL, NULL, NULL + }, { {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT, gettext_noop("Sets the default read-only status of new transactions."), diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 34826d01380b..66c6577eceb8 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -764,6 +764,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate #default_transaction_read_only = off #default_transaction_deferrable = off #session_replication_role = 'origin' +#session_variables_ambiguity_warning = off #statement_timeout = 0 # in milliseconds, 0 is disabled #transaction_timeout = 0 # in milliseconds, 0 is disabled #lock_timeout = 0 # in milliseconds, 0 is disabled diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h index efbaff8e7104..d2209070181b 100644 --- a/src/include/parser/parse_expr.h +++ b/src/include/parser/parse_expr.h @@ -17,6 +17,7 @@ /* GUC parameters */ extern PGDLLIMPORT bool Transform_null_equals; +extern PGDLLIMPORT bool session_variables_ambiguity_warning; extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind); diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out index ab7799005969..a6523f7afe27 100644 --- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out +++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out @@ -354,6 +354,39 @@ $$; NOTICE: session variable is 100 NOTICE: plpgsql variable is 1000 NOTICE: variable is 1000 +-- againt with session_variables_ambiguity_warning(on) +SET session_variables_ambiguity_warning TO on; +DO $$ +<> +DECLARE plpgsql_sv_var1 int; +BEGIN + LET plpgsql_sv_var1 = 100; + + -- should be ok without warning + plpgsql_sv_var1 := 1000; + + -- should be ok without warning + -- print 100; + RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1; + + -- should be ok without warning + -- print 1000 + RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1; + + -- should to print plpgsql variable with warning + -- print 1000 + RAISE NOTICE 'variable is %', plpgsql_sv_var1; +END; +$$; +NOTICE: session variable is 100 +NOTICE: plpgsql variable is 1000 +WARNING: session variable "plpgsql_sv_var1" is shadowed +LINE 1: plpgsql_sv_var1 + ^ +DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name. +QUERY: plpgsql_sv_var1 +NOTICE: variable is 1000 +SET session_variables_ambiguity_warning TO off; DROP VARIABLE plpgsql_sv_var1; -- the value should not be corrupted CREATE VARIABLE plpgsql_sv_v text; diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql index a3cc264cf380..9b8e90e81fac 100644 --- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql +++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql @@ -260,6 +260,35 @@ BEGIN END; $$; +-- againt with session_variables_ambiguity_warning(on) + +SET session_variables_ambiguity_warning TO on; + +DO $$ +<> +DECLARE plpgsql_sv_var1 int; +BEGIN + LET plpgsql_sv_var1 = 100; + + -- should be ok without warning + plpgsql_sv_var1 := 1000; + + -- should be ok without warning + -- print 100; + RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1; + + -- should be ok without warning + -- print 1000 + RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1; + + -- should to print plpgsql variable with warning + -- print 1000 + RAISE NOTICE 'variable is %', plpgsql_sv_var1; +END; +$$; + +SET session_variables_ambiguity_warning TO off; + DROP VARIABLE plpgsql_sv_var1; -- the value should not be corrupted diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out index 2783caa8446d..7c350ad5ef99 100644 --- a/src/test/regress/expected/session_variables.out +++ b/src/test/regress/expected/session_variables.out @@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int); INSERT INTO vartest_foo VALUES(10,20), (30,40); CREATE VARIABLE var1 AS vartest_foo; LET var1 = (100,200); +-- no variable is shadowed here +-- no warning expected +SET session_variables_ambiguity_warning TO on; -- should to fail SELECT var1.* FROM vartest_foo; ERROR: missing FROM-clause entry for table "var1" @@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1; 2 (1 row) +SET session_variables_ambiguity_warning TO off; SET SEARCH_PATH TO DEFAULT; DROP SCHEMA vartest CASCADE; NOTICE: drop cascades to 2 other objects @@ -1943,3 +1947,25 @@ SELECT var1; (1 row) DROP VARIABLE var1, var2; +-- test session_variables_ambiguity_warning +CREATE SCHEMA xxtab; +CREATE VARIABLE xxtab.avar int; +CREATE TABLE public.xxtab(avar int); +INSERT INTO public.xxtab VALUES(1); +LET xxtab.avar = 20; +SET session_variables_ambiguity_warning TO on; +--- should to raise warning, show 1 +SELECT xxtab.avar FROM public.xxtab; +WARNING: session variable "xxtab.avar" is shadowed +LINE 1: SELECT xxtab.avar FROM public.xxtab; + ^ +DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name. + avar +------ + 1 +(1 row) + +SET session_variables_ambiguity_warning TO off; +DROP TABLE public.xxtab; +DROP SCHEMA xxtab CASCADE; +NOTICE: drop cascades to session variable xxtab.avar diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql index a624ab8b67fe..68be415bf26a 100644 --- a/src/test/regress/sql/session_variables.sql +++ b/src/test/regress/sql/session_variables.sql @@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40); CREATE VARIABLE var1 AS vartest_foo; LET var1 = (100,200); +-- no variable is shadowed here +-- no warning expected +SET session_variables_ambiguity_warning TO on; + -- should to fail SELECT var1.* FROM vartest_foo; @@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo; -- should be ok SELECT count(var1.*) FROM vartest_foo var1; +SET session_variables_ambiguity_warning TO off; + SET SEARCH_PATH TO DEFAULT; DROP SCHEMA vartest CASCADE; @@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK; SELECT var1; DROP VARIABLE var1, var2; + +-- test session_variables_ambiguity_warning +CREATE SCHEMA xxtab; + +CREATE VARIABLE xxtab.avar int; + +CREATE TABLE public.xxtab(avar int); + +INSERT INTO public.xxtab VALUES(1); + +LET xxtab.avar = 20; + +SET session_variables_ambiguity_warning TO on; +--- should to raise warning, show 1 +SELECT xxtab.avar FROM public.xxtab; + +SET session_variables_ambiguity_warning TO off; + +DROP TABLE public.xxtab; +DROP SCHEMA xxtab CASCADE; From 4792140145db5716229cd4cc85d03db0ec36f5c0 Mon Sep 17 00:00:00 2001 From: "okbob@github.com" Date: Tue, 19 Nov 2024 08:14:53 +0100 Subject: [PATCH 8/8] variable fence syntax support and variable fence usage guard support this patch introduces a concept of variable fence - syntax for variable reference `VARIABLE(varname)` that is not in collision with column reference. When variable fence usage guard warning is active, then usage variable without variable fence in the case, where there can be column references, the the warning is raised. initial implementation of variable fence --- doc/src/sgml/config.sgml | 65 ++++++++++++++++ doc/src/sgml/ddl.sgml | 15 ++++ src/backend/nodes/nodeFuncs.c | 6 ++ src/backend/parser/gram.y | 28 ++++++- src/backend/parser/parse_expr.c | 74 ++++++++++++++++++- src/backend/parser/parse_target.c | 7 ++ src/backend/utils/adt/ruleutils.c | 12 ++- src/backend/utils/misc/guc_tables.c | 9 +++ src/backend/utils/misc/postgresql.conf.sample | 1 + src/include/nodes/parsenodes.h | 10 +++ src/include/nodes/primnodes.h | 2 + src/include/parser/parse_expr.h | 1 + .../regress/expected/session_variables.out | 59 +++++++++++++++ src/test/regress/sql/session_variables.sql | 41 ++++++++++ 14 files changed, 323 insertions(+), 7 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index a984b5fee7ae..8d3ec6821131 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -11432,6 +11432,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r + + session_variables_use_fence_warning_guard (boolean) + + session_variables_use_fence_warning_guard configuration parameter + + + + + When on, a warning is raised when a session variable identifier is used + inside a query without variable fence. The default is off. + The warning is raised only when variable is used in places, where an + collisions with column names is possible. + +CREATE TABLE foo(a int); +INSERT INTO foo VALUES(10); +CREATE VARIABLE b int; +LET b = 100; +SELECT a, b FROM foo; + + + + a | b +----+----- + 10 | 100 +(1 row) + + + +SET session_variables_use_fence_warning_guard TO on; +SELECT a, b FROM foo; + + + +WARNING: session variable "b" is not used inside variable fence +LINE 1: SELECT a, b FROM foo; + ^ +DETAIL: The collision of session variable' names and column names is possible. + a | b +----+----- + 10 | 100 +(1 row) + + + +SELECT a, VARIABLE(b) FROM foo; + + + + a | b +----+----- + 10 | 100 +(1 row) + + + + + This feature can significantly increase log size, so it's disabled by + default. Unless another collision resolution technique is used + (dedicated schema or using prefixes like _), + the use of variable fence syntax is strongly recommended, and this + warning should be enabled. + + + + standard_conforming_strings (boolean) stringsstandard conforming diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index 3a3f6be79f27..2a25d5ce758d 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -5457,6 +5457,21 @@ SELECT name FROM foo; schema.variable. It is strongly recommended to rename shadowed variables or use qualified names always. + + Variable fence is special syntax for session + variable identifier. Only name or qualified name can be used inside the + variable fence, and this name is used as only session variable identifier. + +SELECT VARIABLE(current_user_id); + + + + + When there is a risk of possible collisions between variable identifiers + and column names, then using variable fence syntax can be recommended. + Usage session variable without variable fence can be detected by + warning . + diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c index d8fc3d9fa69d..575365eefcd3 100644 --- a/src/backend/nodes/nodeFuncs.c +++ b/src/backend/nodes/nodeFuncs.c @@ -1673,6 +1673,9 @@ exprLocation(const Node *expr) case T_ParamRef: loc = ((const ParamRef *) expr)->location; break; + case T_VariableFence: + loc = ((const VariableFence *) expr)->location; + break; case T_A_Const: loc = ((const A_Const *) expr)->location; break; @@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node, return true; } break; + case T_VariableFence: + /* we assume the fields contain nothing interesting */ + break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node)); diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 1074d62b7dbc..72bb33aed613 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type def_arg columnElem where_clause where_or_current_clause a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound columnref in_expr having_clause func_table xmltable array_expr - OptWhereClause operator_def_arg + OptWhereClause operator_def_arg variable_fence %type opt_column_and_period_list %type rowsfrom_item rowsfrom_list opt_col_def_list %type opt_ordinality opt_without_overlaps @@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); */ %nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */ %nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP - SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH + SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE %left Op OPERATOR /* multi-character ops and user-defined operators */ %left '+' '-' %left '*' '/' '%' @@ -15691,6 +15691,19 @@ c_expr: columnref { $$ = $1; } else $$ = $2; } + | variable_fence opt_indirection + { + if ($2) + { + A_Indirection *n = makeNode(A_Indirection); + + n->arg = (Node *) $1; + n->indirection = check_indirection($2, yyscanner); + $$ = (Node *) n; + } + else + $$ = $1; + } | case_expr { $$ = $1; } | func_expr @@ -17077,6 +17090,17 @@ case_arg: a_expr { $$ = $1; } | /*EMPTY*/ { $$ = NULL; } ; +variable_fence: + VARIABLE '(' any_name ')' + { + VariableFence *vf = makeNode(VariableFence); + + vf->varname = $3; + vf->location = @3; + $$ = (Node *) vf; + } + ; + columnref: ColId { $$ = makeColumnRef($1, NIL, @1, yyscanner); diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index b10e1bca3083..fba2eb2de848 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -46,6 +46,7 @@ /* GUC parameters */ bool Transform_null_equals = false; bool session_variables_ambiguity_warning = false; +bool session_variables_use_fence_warning_guard = false; static Node *transformExprRecurse(ParseState *pstate, Node *expr); @@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate, static Node *transformIndirection(ParseState *pstate, A_Indirection *ind); static Node *transformTypeCast(ParseState *pstate, TypeCast *tc); static Node *transformCollateClause(ParseState *pstate, CollateClause *c); +static Node *transformVariableFence(ParseState *pstate, VariableFence *vf); static Node *transformJsonObjectConstructor(ParseState *pstate, JsonObjectConstructor *ctor); static Node *transformJsonArrayConstructor(ParseState *pstate, @@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate, A_Expr *distincta, Node *arg); static Node *makeParamSessionVariable(ParseState *pstate, Oid varid, Oid typid, int32 typmod, Oid collid, - char *attrname, int location); + char *attrname, bool fenced, int location); /* @@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr) result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr); break; + case T_VariableFence: + result = transformVariableFence(pstate, (VariableFence *) expr); + break; + default: /* should not reach here */ elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr)); @@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) node = makeParamSessionVariable(pstate, varid, typid, typmod, collid, - attrname, cref->location); + attrname, false, cref->location); + + /* + * The variable is not inside variable's fence, so raise warning + * when variable fence guard is active and the query has FROM + * clause. + */ + if (session_variables_use_fence_warning_guard && pstate->p_rtable) + ereport(WARNING, + (errcode(ERRCODE_AMBIGUOUS_COLUMN), + errmsg("session variable \"%s\" is not used inside variable fence", + NameListToString(cref->fields)), + errdetail("The collision of session variable' names and column names is possible."), + parser_errposition(pstate, cref->location))); } } } @@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) static Node * makeParamSessionVariable(ParseState *pstate, Oid varid, Oid typid, int32 typmod, Oid collid, - char *attrname, int location) + char *attrname, bool fenced, int location) { Param *param; @@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate, param->paramkind = PARAM_VARIABLE; param->paramvarid = varid; + param->paramvarfenced = fenced; param->paramtype = typid; param->paramtypmod = typmod; param->paramcollid = collid; @@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref) return result; } +static Node * +transformVariableFence(ParseState *pstate, VariableFence *vf) +{ + Node *result; + Oid varid = InvalidOid; + char *attrname = NULL; + bool not_unique; + + /* VariableFence can be used only in context when variables are supported */ + if (!expr_kind_allows_session_variables(pstate->p_expr_kind)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("session variable reference is not supported here"), + parser_errposition(pstate, vf->location))); + + /* takes an AccessShareLock on the session variable */ + varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false); + + if (not_unique) + ereport(ERROR, + (errcode(ERRCODE_AMBIGUOUS_PARAMETER), + errmsg("session variable reference \"%s\" is ambiguous", + NameListToString(vf->varname)), + parser_errposition(pstate, vf->location))); + + if (OidIsValid(varid)) + { + Oid typid; + int32 typmod; + Oid collid; + + get_session_variable_type_typmod_collid(varid, &typid, &typmod, + &collid); + + result = makeParamSessionVariable(pstate, + varid, typid, typmod, collid, + attrname, true, vf->location); + } + else + ereport(ERROR, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("session variable \"%s\" doesn't exist", + NameListToString(vf->varname)), + parser_errposition(pstate, vf->location))); + + return result; +} + /* Test whether an a_expr is a plain NULL constant or not */ static bool exprIsNullConstant(Node *arg) diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c index 4aba0d9d4d5c..cf01bff65a99 100644 --- a/src/backend/parser/parse_target.c +++ b/src/backend/parser/parse_target.c @@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name) (int) ((JsonFuncExpr *) node)->op); } break; + case T_VariableFence: + { + /* return last field name */ + *name = strVal(llast(((VariableFence *) node)->varname)); + return 2; + } + break; default: break; } diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index f23f511cd56d..c347991d16a3 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -8734,8 +8734,16 @@ get_parameter(Param *param, deparse_context *context) /* translate paramvarid to session variable name */ if (param->paramkind == PARAM_VARIABLE) { - appendStringInfo(context->buf, "%s", - generate_session_variable_name(param->paramvarid)); + if (param->paramvarfenced) + { + appendStringInfo(context->buf, "VARIABLE(%s)", + generate_session_variable_name(param->paramvarid)); + } + else + { + appendStringInfo(context->buf, "%s", + generate_session_variable_name(param->paramvarid)); + } return; } diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c index 31d70785b14a..c8c28d769bbc 100644 --- a/src/backend/utils/misc/guc_tables.c +++ b/src/backend/utils/misc/guc_tables.c @@ -1653,6 +1653,15 @@ struct config_bool ConfigureNamesBool[] = false, NULL, NULL, NULL }, + { + {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT, + gettext_noop("Raise a warning when variable is not used inside variable fence."), + NULL + }, + &session_variables_use_fence_warning_guard, + false, + NULL, NULL, NULL + }, { {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT, gettext_noop("Sets the default read-only status of new transactions."), diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 66c6577eceb8..3113e243bce2 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -765,6 +765,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate #default_transaction_deferrable = off #session_replication_role = 'origin' #session_variables_ambiguity_warning = off +#session_variables_use_fence_warning_guard = off #statement_timeout = 0 # in milliseconds, 0 is disabled #transaction_timeout = 0 # in milliseconds, 0 is disabled #lock_timeout = 0 # in milliseconds, 0 is disabled diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 321235c64914..f73ec20d665b 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -321,6 +321,16 @@ typedef struct ParamRef ParseLoc location; /* token location, or -1 if unknown */ } ParamRef; +/* + * VariableFence - ensure so fields will be interpretted as a variable + */ +typedef struct VariableFence +{ + NodeTag type; + List *varname; /* variable name (String nodes) */ + ParseLoc location; /* token location, or -1 if unknown */ +} VariableFence; + /* * A_Expr - infix, prefix, and postfix expressions */ diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 3cc2f019abbf..98bca6944809 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -411,6 +411,8 @@ typedef struct Param * param is used just for execution of UPDATE operation. */ bool parambasenode; + /* true when variable is used inside an fence */ + bool paramvarfenced; /* token location, or -1 if unknown */ ParseLoc location; } Param; diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h index d2209070181b..5bde43758d1b 100644 --- a/src/include/parser/parse_expr.h +++ b/src/include/parser/parse_expr.h @@ -18,6 +18,7 @@ /* GUC parameters */ extern PGDLLIMPORT bool Transform_null_equals; extern PGDLLIMPORT bool session_variables_ambiguity_warning; +extern PGDLLIMPORT bool session_variables_use_fence_warning_guard; extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind); diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out index 7c350ad5ef99..9ac08a14e0bc 100644 --- a/src/test/regress/expected/session_variables.out +++ b/src/test/regress/expected/session_variables.out @@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off; DROP TABLE public.xxtab; DROP SCHEMA xxtab CASCADE; NOTICE: drop cascades to session variable xxtab.avar +-- test session_variables_use_fence_warning_guard +SET session_variables_ambiguity_warning TO on; +SET session_variables_use_fence_warning_guard TO on; +CREATE SCHEMA testvar; +SET search_path TO 'testvar'; +CREATE VARIABLE a AS int; +LET a = 10; +CREATE TABLE test_table(a int, b int); +INSERT INTO test_table VALUES(20, 20); +-- no warning +SELECT a; + a +---- + 10 +(1 row) + +-- warning variable is shadowed +SELECT a, b FROM test_table; +WARNING: session variable "a" is shadowed +LINE 1: SELECT a, b FROM test_table; + ^ +DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name. + a | b +----+---- + 20 | 20 +(1 row) + +-- no warning +SELECT variable(a) FROM test_table; + a +---- + 10 +(1 row) + +ALTER TABLE test_table DROP COLUMN a; +-- warning - variable fence is not used +SELECT a, b FROM test_table; +WARNING: session variable "a" is not used inside variable fence +LINE 1: SELECT a, b FROM test_table; + ^ +DETAIL: The collision of session variable' names and column names is possible. + a | b +----+---- + 10 | 20 +(1 row) + +-- no warning +SELECT variable(a), b FROM test_table; + a | b +----+---- + 10 | 20 +(1 row) + +DROP VARIABLE a; +DROP TABLE test_table; +DROP SCHEMA testvar; +SET session_variables_ambiguity_warning TO DEFAULT; +SET session_variables_use_fence_warning_guard TO DEFAULT; +SET search_path TO DEFAULT; diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql index 68be415bf26a..c5420183d946 100644 --- a/src/test/regress/sql/session_variables.sql +++ b/src/test/regress/sql/session_variables.sql @@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off; DROP TABLE public.xxtab; DROP SCHEMA xxtab CASCADE; + +-- test session_variables_use_fence_warning_guard +SET session_variables_ambiguity_warning TO on; +SET session_variables_use_fence_warning_guard TO on; + +CREATE SCHEMA testvar; + +SET search_path TO 'testvar'; + +CREATE VARIABLE a AS int; +LET a = 10; + +CREATE TABLE test_table(a int, b int); + +INSERT INTO test_table VALUES(20, 20); + +-- no warning +SELECT a; + +-- warning variable is shadowed +SELECT a, b FROM test_table; + +-- no warning +SELECT variable(a) FROM test_table; + +ALTER TABLE test_table DROP COLUMN a; + +-- warning - variable fence is not used +SELECT a, b FROM test_table; + +-- no warning +SELECT variable(a), b FROM test_table; + +DROP VARIABLE a; +DROP TABLE test_table; + +DROP SCHEMA testvar; + +SET session_variables_ambiguity_warning TO DEFAULT; +SET session_variables_use_fence_warning_guard TO DEFAULT; +SET search_path TO DEFAULT;