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/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.177 2002/04/11 19:59:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.178 2002/04/16 23:08:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1526,8 +1526,7 @@ _copyAExpr(A_Expr *from)
 	A_Expr	   *newnode = makeNode(A_Expr);
 
 	newnode->oper = from->oper;
-	if (from->opname)
-		newnode->opname = pstrdup(from->opname);
+	Node_Copy(from, newnode, name);
 	Node_Copy(from, newnode, lexpr);
 	Node_Copy(from, newnode, rexpr);
 
@@ -1648,8 +1647,7 @@ _copySortGroupBy(SortGroupBy *from)
 {
 	SortGroupBy *newnode = makeNode(SortGroupBy);
 
-	if (from->useOp)
-		newnode->useOp = pstrdup(from->useOp);
+	Node_Copy(from, newnode, useOp);
 	Node_Copy(from, newnode, node);
 
 	return newnode;
@@ -2128,7 +2126,7 @@ _copyRemoveOperStmt(RemoveOperStmt *from)
 {
 	RemoveOperStmt *newnode = makeNode(RemoveOperStmt);
 
-	newnode->opname = pstrdup(from->opname);
+	Node_Copy(from, newnode, opname);
 	Node_Copy(from, newnode, args);
 
 	return newnode;

src/backend/nodes/equalfuncs.c

@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.125 2002/04/11 19:59:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.126 2002/04/16 23:08:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -969,7 +969,7 @@ _equalRemoveFuncStmt(RemoveFuncStmt *a, RemoveFuncStmt *b)
 static bool
 _equalRemoveOperStmt(RemoveOperStmt *a, RemoveOperStmt *b)
 {
-	if (!equalstr(a->opname, b->opname))
+	if (!equal(a->opname, b->opname))
 		return false;
 	if (!equal(a->args, b->args))
 		return false;
@@ -1400,7 +1400,7 @@ _equalAExpr(A_Expr *a, A_Expr *b)
 {
 	if (a->oper != b->oper)
 		return false;
-	if (!equalstr(a->opname, b->opname))
+	if (!equal(a->name, b->name))
 		return false;
 	if (!equal(a->lexpr, b->lexpr))
 		return false;
@@ -1520,7 +1520,7 @@ _equalTypeCast(TypeCast *a, TypeCast *b)
 static bool
 _equalSortGroupBy(SortGroupBy *a, SortGroupBy *b)
 {
-	if (!equalstr(a->useOp, b->useOp))
+	if (!equal(a->useOp, b->useOp))
 		return false;
 	if (!equal(a->node, b->node))
 		return false;

src/backend/nodes/makefuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/makefuncs.c,v 1.30 2002/03/29 19:06:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/makefuncs.c,v 1.31 2002/04/16 23:08:10 tgl Exp $
  */
 #include "postgres.h"
 
@@ -16,6 +16,39 @@
 #include "utils/lsyscache.h"
 
 
+/*
+ * makeA_Expr -
+ *		makes an A_Expr node
+ */
+A_Expr *
+makeA_Expr(int oper, List *name, Node *lexpr, Node *rexpr)
+{
+	A_Expr	   *a = makeNode(A_Expr);
+
+	a->oper = oper;
+	a->name = name;
+	a->lexpr = lexpr;
+	a->rexpr = rexpr;
+	return a;
+}
+
+/*
+ * makeSimpleA_Expr -
+ *		As above, given a simple (unqualified) operator name
+ */
+A_Expr *
+makeSimpleA_Expr(int oper, const char *name,
+				 Node *lexpr, Node *rexpr)
+{
+	A_Expr	   *a = makeNode(A_Expr);
+
+	a->oper = oper;
+	a->name = makeList1(makeString((char *) name));
+	a->lexpr = lexpr;
+	a->rexpr = rexpr;
+	return a;
+}
+
 /*
  * makeOper -
  *	  creates an Oper node

src/backend/nodes/outfuncs.c

@@ -5,7 +5,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.154 2002/04/11 19:59:59 tgl Exp $
+ *	$Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.155 2002/04/16 23:08:10 tgl Exp $
  *
  * NOTES
  *	  Every (plan) node in POSTGRES has an associated "out" routine which
@@ -1285,7 +1285,7 @@ _outAExpr(StringInfo str, A_Expr *node)
 			appendStringInfo(str, "NOT ");
 			break;
 		case OP:
-			_outToken(str, node->opname);
+			_outNode(str, node->name);
 			appendStringInfo(str, " ");
 			break;
 		default: