All the databases that I've worked on (that actually have the ability to
drop columns) generate an error if the column to be dropped is part of a
key, and I think that is sound behaviour.

MikeA


-----Original Message-----
From: Ed Loehr
To: Tom Lane
Cc: Hiroshi Inoue; Peter Eisentraut; pgsql-hackers@postgreSQL.org
Sent: 00/01/24 08:13
Subject: Re: [HACKERS] Well, then you keep your darn columns

Tom Lane wrote:

> Let's see: DROP COLUMN would have to mark the column invisible, remove
> any associated constraints (particularly NOT NULL) and indexes, and
> it'd be done.  The parser would then have to ignore the column when
> doing column name lookups or expansion of '*', and it would have to
> insert a NULL value for the column when transforming INSERT or UPDATE.
> And that'd be just about it.  I like it.

How would you handle multi-column indices that included the column
being dropped?  E.g.,

	create unique index foobar on mytable(foo,bar);

where the 'bar' column is then dropped...

Dropping all of that index would seem to be problematic.

Cheers,
Ed Loehr

************

Mon, 24 Jan 2000 23:39:27 +0200
"Ansley, Michael" <Michael.Ansley@intec.co.za>
RE: [HACKERS] Well, then you keep your darn columns