Attached is a patch for ALTER TRIGGER RENAME per the above thread. I

left a stub for a future "ALTER RULE RENAME" but did not write that one
yet. Bruce, if you want to add my name for for that I'll take it and do
it later.

Joe Conway

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.8 2002/04/24 02:38:58 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.9 2002/04/24 02:48:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2846,6 +2846,123 @@ renamerel(Oid relid, const char *newrelname)
 	relation_close(targetrelation, NoLock);
 }
 
+/*
+ *		renametrig		- changes the name of a trigger on a relation
+ *
+ *		trigger name is changed in trigger catalog.
+ *		No record of the previous name is kept.
+ *
+ *		get proper relrelation from relation catalog (if not arg)
+ *		scan trigger catalog
+ *				for name conflict (within rel)
+ *				for original trigger (if not arg)
+ *		modify tgname in trigger tuple
+ *		insert modified trigger in trigger catalog
+ *		delete original trigger from trigger catalog
+ */
+extern void renametrig(Oid relid,
+		  const char *oldname,
+		  const char *newname)
+{
+	Relation	targetrel;
+	Relation	tgrel;
+	HeapTuple	tuple;
+	SysScanDesc	tgscan;
+	ScanKeyData key;
+	bool		found = FALSE;
+	Relation	idescs[Num_pg_trigger_indices];
+
+	/*
+	 * Grab an exclusive lock on the target table, which we will NOT
+	 * release until end of transaction.
+	 */
+	targetrel = heap_open(relid, AccessExclusiveLock);
+
+	/*
+	 * Scan pg_trigger twice for existing triggers on relation.  We do this in
+	 * order to ensure a trigger does not exist with newname (The unique index
+	 * on tgrelid/tgname would complain anyway) and to ensure a trigger does
+	 * exist with oldname.
+	 *
+	 * NOTE that this is cool only because we have AccessExclusiveLock on the
+	 * relation, so the trigger set won't be changing underneath us.
+	 */
+	tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
+
+	/*
+	 * First pass -- look for name conflict
+	 */
+	ScanKeyEntryInitialize(&key, 0,
+						   Anum_pg_trigger_tgrelid,
+						   F_OIDEQ,
+						   ObjectIdGetDatum(relid));
+	tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
+								SnapshotNow, 1, &key);
+	while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
+	{
+		Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
+
+		if (namestrcmp(&(pg_trigger->tgname), newname) == 0)
+			elog(ERROR, "renametrig: trigger %s already defined on relation %s",
+				 newname, RelationGetRelationName(targetrel));
+	}
+	systable_endscan(tgscan);
+
+	/*
+	 * Second pass -- look for trigger existing with oldname and update
+	 */
+	ScanKeyEntryInitialize(&key, 0,
+						   Anum_pg_trigger_tgrelid,
+						   F_OIDEQ,
+						   ObjectIdGetDatum(relid));
+	tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
+								SnapshotNow, 1, &key);
+	while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
+	{
+		Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
+
+		if (namestrcmp(&(pg_trigger->tgname), oldname) == 0)
+		{
+			/*
+			 * Update pg_trigger tuple with new tgname.
+			 * (Scribbling on tuple is OK because it's a copy...)
+			 */
+			namestrcpy(&(pg_trigger->tgname), newname);
+			simple_heap_update(tgrel, &tuple->t_self, tuple);
+
+			/*
+			 * keep system catalog indices current
+			 */
+			CatalogOpenIndices(Num_pg_trigger_indices, Name_pg_trigger_indices, idescs);
+			CatalogIndexInsert(idescs, Num_pg_trigger_indices, tgrel, tuple);
+			CatalogCloseIndices(Num_pg_trigger_indices, idescs);
+
+			/*
+			 * Invalidate relation's relcache entry so that other
+			 * backends (and this one too!) are sent SI message to make them
+			 * rebuild relcache entries.
+			 */
+			CacheInvalidateRelcache(relid);
+
+			found = TRUE;
+			break;
+		}
+	}
+	systable_endscan(tgscan);
+
+	heap_close(tgrel, RowExclusiveLock);
+
+	if (!found)
+		elog(ERROR, "renametrig: trigger %s not defined on relation %s",
+			 oldname, RelationGetRelationName(targetrel));
+
+	/*
+	 * Close rel, but keep exclusive lock!
+	 */
+	heap_close(targetrel, NoLock);
+}
+
+
 /*
  * Given a trigger function OID, determine whether it is an RI trigger,
  * and if so whether it is attached to PK or FK relation.

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 1.180 2002/04/18 20:01:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.181 2002/04/24 02:48:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2137,10 +2137,11 @@ _copyRenameStmt(RenameStmt *from)
 	RenameStmt *newnode = makeNode(RenameStmt);
 
 	Node_Copy(from, newnode, relation);
-	if (from->column)
-		newnode->column = pstrdup(from->column);
+	if (from->oldname)
+		newnode->oldname = pstrdup(from->oldname);
 	if (from->newname)
 		newnode->newname = pstrdup(from->newname);
+	newnode->renameType = from->renameType;
 
 	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 1.128 2002/04/18 20:01:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.129 2002/04/24 02:48:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -983,10 +983,12 @@ _equalRenameStmt(RenameStmt *a, RenameStmt *b)
 {
 	if (!equal(a->relation, b->relation))
 		return false;
-	if (!equalstr(a->column, b->column))
+	if (!equalstr(a->oldname, b->oldname))
 		return false;
 	if (!equalstr(a->newname, b->newname))
 		return false;
+	if (a->renameType != b->renameType)
+		return false;
 
 	return true;
 }

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.309 2002/04/21 21:53:23 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.310 2002/04/24 02:48:54 momjian Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -2919,8 +2919,21 @@ RenameStmt:  ALTER TABLE relation_expr RENAME opt_column opt_name TO name
 				{
 					RenameStmt *n = makeNode(RenameStmt);
 					n->relation = $3;
-					n->column = $6;
+					n->oldname = $6;
 					n->newname = $8;
+					if ($6 == NULL)
+						n->renameType = RENAME_TABLE;
+					else
+						n->renameType = RENAME_COLUMN;
+					$$ = (Node *)n;
+				}
+		| ALTER TRIGGER name ON relation_expr RENAME TO name
+				{
+					RenameStmt *n = makeNode(RenameStmt);
+					n->relation = $5;
+					n->oldname = $3;
+					n->newname = $8;
+					n->renameType = RENAME_TRIGGER;
 					$$ = (Node *)n;
 				}
 		;

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.150 2002/04/18 20:01:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.151 2002/04/24 02:48:55 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -377,23 +377,30 @@ ProcessUtility(Node *parsetree,
 
 				CheckOwnership(stmt->relation, true);
 
-				if (stmt->column == NULL)
+				switch (stmt->renameType)
 				{
-					/*
-					 * rename relation
-					 */
-					renamerel(RangeVarGetRelid(stmt->relation, false),
-							  stmt->newname);
-				}
-				else
-				{
-					/*
-					 * rename attribute
-					 */
-					renameatt(RangeVarGetRelid(stmt->relation, false),
-							  stmt->column,		/* old att name */
+					case RENAME_TABLE:
+						renamerel(RangeVarGetRelid(stmt->relation, false),
+								  stmt->newname);
+						break;
+					case RENAME_COLUMN:
+						renameatt(RangeVarGetRelid(stmt->relation, false),
+							  stmt->oldname,	/* old att name */
 							  stmt->newname,	/* new att name */
-							  interpretInhOption(stmt->relation->inhOpt));		/* recursive? */
+							  interpretInhOption(stmt->relation->inhOpt));	/* recursive? */
+						break;
+					case RENAME_TRIGGER:
+						renametrig(RangeVarGetRelid(stmt->relation, false),
+							  stmt->oldname,	/* old att name */
+							  stmt->newname);	/* new att name */
+						break;
+					case RENAME_RULE:
+						elog(ERROR, "ProcessUtility: Invalid target for RENAME: %d",
+								stmt->renameType);
+						break;
+					default:
+						elog(ERROR, "ProcessUtility: Invalid target for RENAME: %d",
+								stmt->renameType);
 				}
 			}
 			break;

src/include/commands/tablecmds.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: tablecmds.h,v 1.1 2002/04/15 05:22:04 tgl Exp $
+ * $Id: tablecmds.h,v 1.2 2002/04/24 02:48:55 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,6 +15,7 @@
 #define TABLECMDS_H
 
 #include "nodes/parsenodes.h"
+#include "utils/inval.h"
 
 extern void AlterTableAddColumn(Oid myrelid, bool inherits,
 								ColumnDef *colDef);
@@ -60,4 +61,8 @@ extern void renameatt(Oid relid,
 extern void renamerel(Oid relid,
 		  const char *newrelname);
 
+extern void renametrig(Oid relid,
+		  const char *oldname,
+		  const char *newname);
+
 #endif   /* TABLECMDS_H */

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.173 2002/04/21 00:26:43 tgl Exp $
+ * $Id: parsenodes.h,v 1.174 2002/04/24 02:48:55 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1233,17 +1233,23 @@ typedef struct RemoveOperStmt
 } RemoveOperStmt;
 
 /* ----------------------
- *		Alter Table Rename Statement
+ *		Alter Object Rename Statement
  * ----------------------
+ * Currently supports renaming tables, table columns, and triggers.
+ * If renaming a table, oldname is ignored.
  */
+#define RENAME_TABLE	110
+#define RENAME_COLUMN	111
+#define RENAME_TRIGGER	112
+#define RENAME_RULE		113
+
 typedef struct RenameStmt
 {
 	NodeTag		type;
-	RangeVar   *relation;		/* relation to be altered */
-	char	   *column;			/* if NULL, rename the relation name to
-								 * the new name. Otherwise, rename this
-								 * column name. */
+	RangeVar   *relation;		/* owning relation */
+	char	   *oldname;		/* name of rule, trigger, etc */
 	char	   *newname;		/* the new name */
+	int			renameType;		/* RENAME_TABLE, RENAME_COLUMN, etc */
 } RenameStmt;
 
 /* ----------------------