Generalize concept of temporary relations to "relation persistence".

This commit replaces pg_class.relistemp with pg_class.relpersistence;
and also modifies the RangeVar node type to carry relpersistence rather
than istemp.  It also removes removes rd_istemp from RelationData and
instead performs the correct computation based on relpersistence.

For clarity, we add three new macros: RelationNeedsWAL(),
RelationUsesLocalBuffers(), and RelationUsesTempNamespace(), so that we
can clarify the purpose of each check that previous depended on
rd_istemp.

This is intended as infrastructure for the upcoming unlogged tables
patch, as well as for future possible work on global temporary tables.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/backend/commands/tablespace.c b/src/backend/commands/tablespace.c
index cd80c811a92..5ad08314049 100644
--- a/src/backend/commands/tablespace.c
+++ b/src/backend/commands/tablespace.c
@@ -1050,8 +1050,8 @@ assign_default_tablespace(const char *newval, bool doit, GucSource source)
 /*
  * GetDefaultTablespace -- get the OID of the current default tablespace
  *
- * Regular objects and temporary objects have different default tablespaces,
- * hence the forTemp parameter must be specified.
+ * Temporary objects have different default tablespaces, hence the
+ * relpersistence parameter must be specified.
  *
  * May return InvalidOid to indicate "use the database's default tablespace".
  *
@@ -1062,12 +1062,12 @@ assign_default_tablespace(const char *newval, bool doit, GucSource source)
  * default_tablespace GUC variable.
  */
 Oid
-GetDefaultTablespace(bool forTemp)
+GetDefaultTablespace(char relpersistence)
 {
 	Oid			result;
 
 	/* The temp-table case is handled elsewhere */
-	if (forTemp)
+	if (relpersistence == RELPERSISTENCE_TEMP)
 	{
 		PrepareTempTablespaces();
 		return GetNextTempTableSpace();