| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Andres Freund <andres(at)anarazel(dot)de>, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: slow queries over information schema.tables |
| Date: | 2018-12-06 16:50:48 |
| Message-ID: | CA+TgmoaNhWkCt2MBpvhHX2ckJd=JHTqDAS1oXRdQPuVtp2MD=g@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Thu, Dec 6, 2018 at 11:32 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> > I'm not thrilled about depending on sinval without locking,
> > particularly given that my proposal to make sure we
> > AcceptInvalidationMessages() at least once per query was shouted down.
>
> It's fairly hard to imagine practical cases where we'd not call
> AcceptInvalidationMessages at least once per query, so I'm not
> very sure what you're on about.
Unless I'm confused, it happens any time you run a query that only
touches tables using lockmodes previously acquired by the current
transaction. Like:
BEGIN;
some query;
the same query again;
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2018-12-06 16:55:39 | Re: [PATCH] Opclass parameters |
| Previous Message | Pavel Stehule | 2018-12-06 16:49:35 | Re: proposal: plpgsql pragma statement |