Add transforms feature

This provides a mechanism for specifying conversions between SQL data
types and procedural languages.  As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.

reviews by Pavel Stěhule and Andres Freund

1 files changed, 15 insertions, 0 deletions

diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 3bc81762af5..578ead54632 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1780,6 +1780,18 @@ _equalImportForeignSchemaStmt(const ImportForeignSchemaStmt *a, const ImportFore
 }
 
 static bool
+_equalCreateTransformStmt(const CreateTransformStmt *a, const CreateTransformStmt *b)
+{
+	COMPARE_SCALAR_FIELD(replace);
+	COMPARE_NODE_FIELD(type_name);
+	COMPARE_STRING_FIELD(lang);
+	COMPARE_NODE_FIELD(fromsql);
+	COMPARE_NODE_FIELD(tosql);
+
+	return true;
+}
+
+static bool
 _equalCreateTrigStmt(const CreateTrigStmt *a, const CreateTrigStmt *b)
 {
 	COMPARE_STRING_FIELD(trigname);
@@ -2991,6 +3003,9 @@ equal(const void *a, const void *b)
 		case T_ImportForeignSchemaStmt:
 			retval = _equalImportForeignSchemaStmt(a, b);
 			break;
+		case T_CreateTransformStmt:
+			retval = _equalCreateTransformStmt(a, b);
+			break;
 		case T_CreateTrigStmt:
 			retval = _equalCreateTrigStmt(a, b);
 			break;