X-Git-Url: https://granicus.if.org/sourcecode?a=blobdiff_plain;f=src%2Fbackend%2Futils%2Fcache%2Flsyscache.c;h=7a4306e93f5545764cbd02e6aa042120b385790c;hb=c6e3ac11b60ac4a8942ab964252d51c1c0bd8845;hp=ceca0e3ede0f1b5584ae290b4cb08cd369d8bd10;hpb=b985d48779146b7ba969b0963614ad7683589bc8;p=postgresql

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index ceca0e3ede..7a4306e93f 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -244,19 +244,22 @@ get_ordering_op_properties(Oid opno,
 }
 
 /*
- * get_compare_function_for_ordering_op
- *		Get the OID of the datatype-specific btree comparison function
+ * get_sort_function_for_ordering_op
+ *		Get the OID of the datatype-specific btree sort support function,
+ *		or if there is none, the btree comparison function,
  *		associated with an ordering operator (a "<" or ">" operator).
  *
- * *cmpfunc receives the comparison function OID.
+ * *sortfunc receives the support or comparison function OID.
+ * *issupport is set TRUE if it's a support func, FALSE if a comparison func.
  * *reverse is set FALSE if the operator is "<", TRUE if it's ">"
- * (indicating the comparison result must be negated before use).
+ * (indicating that comparison results must be negated before use).
  *
  * Returns TRUE if successful, FALSE if no btree function can be found.
  * (This indicates that the operator is not a valid ordering operator.)
  */
 bool
-get_compare_function_for_ordering_op(Oid opno, Oid *cmpfunc, bool *reverse)
+get_sort_function_for_ordering_op(Oid opno, Oid *sortfunc,
+								  bool *issupport, bool *reverse)
 {
 	Oid			opfamily;
 	Oid			opcintype;
@@ -267,21 +270,31 @@ get_compare_function_for_ordering_op(Oid opno, Oid *cmpfunc, bool *reverse)
 								   &opfamily, &opcintype, &strategy))
 	{
 		/* Found a suitable opfamily, get matching support function */
-		*cmpfunc = get_opfamily_proc(opfamily,
-									 opcintype,
-									 opcintype,
-									 BTORDER_PROC);
-
-		if (!OidIsValid(*cmpfunc))		/* should not happen */
-			elog(ERROR, "missing support function %d(%u,%u) in opfamily %u",
-				 BTORDER_PROC, opcintype, opcintype, opfamily);
+		*sortfunc = get_opfamily_proc(opfamily,
+									  opcintype,
+									  opcintype,
+									  BTSORTSUPPORT_PROC);
+		if (OidIsValid(*sortfunc))
+			*issupport = true;
+		else
+		{
+			/* opfamily doesn't provide sort support, get comparison func */
+			*sortfunc = get_opfamily_proc(opfamily,
+										  opcintype,
+										  opcintype,
+										  BTORDER_PROC);
+			if (!OidIsValid(*sortfunc))		/* should not happen */
+				elog(ERROR, "missing support function %d(%u,%u) in opfamily %u",
+					 BTORDER_PROC, opcintype, opcintype, opfamily);
+			*issupport = false;
+		}
 		*reverse = (strategy == BTGreaterStrategyNumber);
 		return true;
 	}
 
 	/* ensure outputs are set on failure */
-	*cmpfunc = InvalidOid;
-
+	*sortfunc = InvalidOid;
+	*issupport = false;
 	*reverse = false;
 	return false;
 }
@@ -1890,10 +1903,9 @@ getTypeIOParam(HeapTuple typeTuple)
 
 	/*
 	 * Array types get their typelem as parameter; everybody else gets their
-	 * own type OID as parameter.  (As of 8.2, domains must get their own OID
-	 * even if their base type is an array.)
+	 * own type OID as parameter.
 	 */
-	if (typeStruct->typtype == TYPTYPE_BASE && OidIsValid(typeStruct->typelem))
+	if (OidIsValid(typeStruct->typelem))
 		return typeStruct->typelem;
 	else
 		return HeapTupleGetOid(typeTuple);