Operators live in namespaces. CREATE/DROP/COMMENT ON OPERATOR take

qualified operator names directly, for example CREATE OPERATOR myschema.+
( ... ).  To qualify an operator name in an expression you need to write
OPERATOR(myschema.+) (thanks to Peter for suggesting an escape hatch).
I also took advantage of having to reformat pg_operator to fix something
that'd been bugging me for a while: mergejoinable operators should have
explicit links to the associated cross-data-type comparison operators,
rather than hardwiring an assumption that they are named < and >.

src/include/utils/syscache.h

@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: syscache.h,v 1.44 2002/04/11 20:00:17 tgl Exp $
+ * $Id: syscache.h,v 1.45 2002/04/16 23:08:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,7 +46,7 @@
 #define LANGOID			15
 #define NAMESPACENAME	16
 #define NAMESPACEOID	17
-#define OPERNAME		18
+#define OPERNAMENSP		18
 #define OPEROID			19
 #define PROCNAMENSP		20
 #define PROCOID			21