This patch implements ORACLE's COMMENT SQL command.

>From the ORACLE 7 SQL Language Reference Manual:
-----------------------------------------------------
COMMENT

Purpose:

To add a comment about a table, view, snapshot, or
column into the data dictionary.

Prerequisites:

The table, view, or snapshot must be in your own
schema
or you must have COMMENT ANY TABLE system privilege.

Syntax:

COMMENT ON [ TABLE table ] |
           [ COLUMN table.column] IS 'text'

You can effectively drop a comment from the database
by setting it to the empty string ''.
-----------------------------------------------------

Example:

COMMENT ON TABLE workorders IS
   'Maintains base records for workorder information';

COMMENT ON COLUMN workorders.hours IS
   'Number of hours the engineer worked on the task';

to drop a comment:

COMMENT ON COLUMN workorders.hours IS '';

The current patch will simply perform the insert into
pg_description, as per the TODO. And, of course, when
the table is dropped, any comments relating to it
or any of its attributes are also dropped. I haven't
looked at the ODBC source yet, but I do know from
an ODBC client standpoint that the standard does
support the notion of table and column comments.
Hopefully the ODBC driver is already fetching these
values from pg_description, but if not, it should be
trivial.

Hope this makes the grade,

Mike Mascari
(mascarim@yahoo.com)

src/backend/parser/keywords.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.62 1999/09/29 16:06:08 wieck Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.63 1999/10/15 01:49:41 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -60,6 +60,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"coalesce", COALESCE},
 	{"collate", COLLATE},
 	{"column", COLUMN},
+	{"comment", COMMENT},
 	{"commit", COMMIT},
 	{"committed", COMMITTED},
 	{"constraint", CONSTRAINT},