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, 9 insertions, 35 deletions

diff --git a/src/backend/commands/operatorcmds.c b/src/backend/commands/operatorcmds.c
index 76884e8cd82..a84feee2a71 100644
--- a/src/backend/commands/operatorcmds.c
+++ b/src/backend/commands/operatorcmds.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/operatorcmds.c,v 1.33 2006/10/04 00:29:51 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/operatorcmds.c,v 1.34 2006/12/23 00:43:09 tgl Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -64,8 +64,8 @@ DefineOperator(List *names, List *parameters)
 	char	   *oprName;
 	Oid			oprNamespace;
 	AclResult	aclresult;
-	bool		canHash = false;	/* operator hashes */
 	bool		canMerge = false;		/* operator merges */
+	bool		canHash = false;		/* operator hashes */
 	List	   *functionName = NIL;		/* function for operator */
 	TypeName   *typeName1 = NULL;		/* first type name */
 	TypeName   *typeName2 = NULL;		/* second type name */
@@ -75,10 +75,6 @@ DefineOperator(List *names, List *parameters)
 	List	   *negatorName = NIL;		/* optional negator operator name */
 	List	   *restrictionName = NIL;	/* optional restrict. sel. procedure */
 	List	   *joinName = NIL; /* optional join sel. procedure */
-	List	   *leftSortName = NIL;		/* optional left sort operator */
-	List	   *rightSortName = NIL;	/* optional right sort operator */
-	List	   *ltCompareName = NIL;	/* optional < compare operator */
-	List	   *gtCompareName = NIL;	/* optional > compare operator */
 	ListCell   *pl;
 
 	/* Convert list of names to a name and namespace */
@@ -127,14 +123,15 @@ DefineOperator(List *names, List *parameters)
 			canHash = defGetBoolean(defel);
 		else if (pg_strcasecmp(defel->defname, "merges") == 0)
 			canMerge = defGetBoolean(defel);
+		/* These obsolete options are taken as meaning canMerge */
 		else if (pg_strcasecmp(defel->defname, "sort1") == 0)
-			leftSortName = defGetQualifiedName(defel);
+			canMerge = true;
 		else if (pg_strcasecmp(defel->defname, "sort2") == 0)
-			rightSortName = defGetQualifiedName(defel);
+			canMerge = true;
 		else if (pg_strcasecmp(defel->defname, "ltcmp") == 0)
-			ltCompareName = defGetQualifiedName(defel);
+			canMerge = true;
 		else if (pg_strcasecmp(defel->defname, "gtcmp") == 0)
-			gtCompareName = defGetQualifiedName(defel);
+			canMerge = true;
 		else
 			ereport(WARNING,
 					(errcode(ERRCODE_SYNTAX_ERROR),
@@ -157,26 +154,6 @@ DefineOperator(List *names, List *parameters)
 		typeId2 = typenameTypeId(NULL, typeName2);
 
 	/*
-	 * If any of the mergejoin support operators were given, then canMerge is
-	 * implicit.  If canMerge is specified or implicit, fill in default
-	 * operator names for any missing mergejoin support operators.
-	 */
-	if (leftSortName || rightSortName || ltCompareName || gtCompareName)
-		canMerge = true;
-
-	if (canMerge)
-	{
-		if (!leftSortName)
-			leftSortName = list_make1(makeString("<"));
-		if (!rightSortName)
-			rightSortName = list_make1(makeString("<"));
-		if (!ltCompareName)
-			ltCompareName = list_make1(makeString("<"));
-		if (!gtCompareName)
-			gtCompareName = list_make1(makeString(">"));
-	}
-
-	/*
 	 * now have OperatorCreate do all the work..
 	 */
 	OperatorCreate(oprName,		/* operator name */
@@ -188,11 +165,8 @@ DefineOperator(List *names, List *parameters)
 				   negatorName, /* optional negator operator name */
 				   restrictionName,		/* optional restrict. sel. procedure */
 				   joinName,	/* optional join sel. procedure name */
-				   canHash,		/* operator hashes */
-				   leftSortName,	/* optional left sort operator */
-				   rightSortName,		/* optional right sort operator */
-				   ltCompareName,		/* optional < comparison op */
-				   gtCompareName);		/* optional < comparison op */
+				   canMerge,	/* operator merges */
+				   canHash);	/* operator hashes */
 }