| From: | Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com> |
|---|---|
| To: | Josh Berkus <josh(at)agliodbs(dot)com> |
| Cc: | <pgsql-sql(at)postgresql(dot)org> |
| Subject: | Re: Constraint problem |
| Date: | 2002-05-16 20:39:19 |
| Message-ID: | 20020516132750.P93696-100000@megazone23.bigpanda.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-sql |
On Thu, 16 May 2002, Josh Berkus wrote:
>
> Stephan,
> > > I don't seem to be able to create a UNIQUE constraint as DEFERRABLE. Is
> this
> > > not supported?
> >
> > Not currently.
>
> Hmm ... my workaround didn't work. I need to impose a unique constraint on
> an INT column in a table, but make sure that the constraint isn't checked
> until the end of an UPDATE statement, so that I can swap values when I need
> to.
>
> How can I do this?
I unfortunately can't think of a good workaround. AFAICT, Unique should
wait until after all of the updates but our implementation doesn't
currently do so.
Hopefully someone will have some ideas, because the best I can think of
requires an additional full table scan to check uniqueness and the
concurrency issues would be a bear.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Joel Burton | 2002-05-16 20:43:37 | Re: SQL over my head... |
| Previous Message | Gregory Brauer | 2002-05-16 20:39:09 | Re: SQL over my head... |