Restructure operator classes to allow improved handling of cross-data-type

cases.  Operator classes now exist within "operator families".  While most
families are equivalent to a single class, related classes can be grouped
into one family to represent the fact that they are semantically compatible.
Cross-type operators are now naturally adjunct parts of a family, without
having to wedge them into a particular opclass as we had done originally.

This commit restructures the catalogs and cleans up enough of the fallout so
that everything still works at least as well as before, but most of the work
needed to actually improve the planner's behavior will come later.  Also,
there are not yet CREATE/DROP/ALTER OPERATOR FAMILY commands; the only way
to create a new family right now is to allow CREATE OPERATOR CLASS to make
one by default.  I owe some more documentation work, too.  But that can all
be done in smaller pieces once this infrastructure is in place.

1 files changed, 5 insertions, 22 deletions

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index a99942010b6..b2ff95f457b 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2,7 +2,7 @@
  * ruleutils.c	- Functions to convert stored expressions/querytrees
  *				back to source text
  *
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.236 2006/12/21 16:05:15 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.237 2006/12/23 00:43:11 tgl Exp $
  **********************************************************************/
 
 #include "postgres.h"
@@ -19,6 +19,7 @@
 #include "catalog/pg_opclass.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_trigger.h"
+#include "commands/defrem.h"
 #include "executor/spi.h"
 #include "funcapi.h"
 #include "nodes/makefuncs.h"
@@ -4717,11 +4718,6 @@ get_opclass_name(Oid opclass, Oid actual_datatype,
 	Form_pg_opclass opcrec;
 	char	   *opcname;
 	char	   *nspname;
-	bool		isvisible;
-
-	/* Domains use their base type's default opclass */
-	if (OidIsValid(actual_datatype))
-		actual_datatype = getBaseType(actual_datatype);
 
 	ht_opc = SearchSysCache(CLAOID,
 							ObjectIdGetDatum(opclass),
@@ -4730,25 +4726,12 @@ get_opclass_name(Oid opclass, Oid actual_datatype,
 		elog(ERROR, "cache lookup failed for opclass %u", opclass);
 	opcrec = (Form_pg_opclass) GETSTRUCT(ht_opc);
 
-	/*
-	 * Special case for ARRAY_OPS: pretend it is default for any array type
-	 */
-	if (OidIsValid(actual_datatype))
-	{
-		if (opcrec->opcintype == ANYARRAYOID &&
-			OidIsValid(get_element_type(actual_datatype)))
-			actual_datatype = opcrec->opcintype;
-	}
-
-	/* Must force use of opclass name if not in search path */
-	isvisible = OpclassIsVisible(opclass);
-
-	if (actual_datatype != opcrec->opcintype || !opcrec->opcdefault ||
-		!isvisible)
+	if (!OidIsValid(actual_datatype) ||
+		GetDefaultOpClass(actual_datatype, opcrec->opcmethod) != opclass)
 	{
 		/* Okay, we need the opclass name.	Do we need to qualify it? */
 		opcname = NameStr(opcrec->opcname);
-		if (isvisible)
+		if (OpclassIsVisible(opclass))
 			appendStringInfo(buf, " %s", quote_identifier(opcname));
 		else
 		{