| From: | Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> |
|---|---|
| To: | Bruno Wolff III <bruno(at)wolff(dot)to> |
| Cc: | Vivek Khera <khera(at)kcilink(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: deferred foreign keys |
| Date: | 2004-01-05 18:57:02 |
| Message-ID: | 20040105105401.C72490@megazone.bigpanda.com |
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| Thread: | |
| Lists: | pgsql-performance |
On Mon, 5 Jan 2004, Bruno Wolff III wrote:
> On Mon, Jan 05, 2004 at 11:33:40 -0500,
> Vivek Khera <khera(at)kcilink(dot)com> wrote:
> >
> > Thanks. Then it sorta makes it moot for me to try deferred checks,
> > since the Pimary and Foreign keys never change once set. I wonder
> > what is making the transactions appear to run lockstep, then...
>
> I think this is probably the issue with foreign key checks needing an
> exclusive lock, since there is no shared lock that will prevent deletes.
But, if he's updating the fk table but not the keyed column, it should no
longer be doing the check and grabbing the locks. If he's seeing it grab
the row locks still a full test case would be handy because it'd probably
mean we missed something.
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