From: | Jeff Davis <pgsql(at)j-davis(dot)com> |
---|---|
To: | Greg Stark <greg(dot)stark(at)enterprisedb(dot)com> |
Cc: | pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>, "npboley(at)gmail(dot)com" <npboley(at)gmail(dot)com> |
Subject: | Re: More FOR UPDATE/FOR SHARE problems |
Date: | 2009-01-24 23:47:51 |
Message-ID: | 1232840871.6610.40.camel@jdavis |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Sat, 2009-01-24 at 19:45 +0000, Greg Stark wrote:
> There already is quite an extensive discussion of how FOR UPDATE
> behaves including these kinds of violations.
Not in the documentation, that I can see. And I think it's important
that it be there for the reasons I mentioned.
Can you refer me to the dicussion that you're talking about? I don't
remember any discussion that points out that FOR UPDATE/FOR SHARE is
broken in the simple case of a simple WHERE clause.
> What you propose is interesting though. It would have been impossible
> before subtransactions but it's doable now. Still the performance
> might be unusable for complex queries. It's basically generalizing the
> logic a serializable transaction would take to a read committed command.
It might be effective for queries that are highly selective on large
tables. Still has strange deadlock possibilities, but I think that's the
case already.
Regards,
Jeff Davis
From | Date | Subject | |
---|---|---|---|
Next Message | Mark Kirkwood | 2009-01-24 23:48:07 | Re: Hot Standby (v9d) |
Previous Message | Bruce Momjian | 2009-01-24 23:44:35 | Re: Time to finalize patches for 8.4 beta |