I've created a new shared catalog table pg_shdescription to store

comments on cluster global objects like databases, tablespaces, and
roles.

It touches a lot of places, but not much in the way of big changes.  The
only design decision I made was to duplicate the query and manipulation
functions rather than to try and have them handle both shared and local
comments.  I believe this is simpler for the code and not an issue for
callers because they know what type of object they are dealing with.
This has resulted in a shobj_description function analagous to
obj_description and backend functions [Create/Delete]SharedComments
mirroring the existing [Create/Delete]Comments functions.

pg_shdescription.h goes into src/include/catalog/

Kris Jurka

src/backend/commands/user.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.168 2006/02/04 19:06:46 adunstan Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/user.c,v 1.169 2006/02/12 03:22:17 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,6 +18,7 @@
 #include "catalog/indexing.h"
 #include "catalog/pg_auth_members.h"
 #include "catalog/pg_authid.h"
+#include "commands/comment.h"
 #include "commands/user.h"
 #include "libpq/crypt.h"
 #include "miscadmin.h"
@@ -940,6 +941,11 @@ DropRole(DropRoleStmt *stmt)
 
 		systable_endscan(sscan);
 
+		/*
+		 * Remove any comments on this role.
+		 */
+		DeleteSharedComments(roleid, AuthIdRelationId);
+
 		/*
 		 * Advance command counter so that later iterations of this loop will
 		 * see the changes already made.  This is essential if, for example,