Horton

RE: locking [user] catalog tables vs 2pc vs logical rep

Takamichi Osumi (Fujitsu) <osumi.takamichi@fujitsu.com>

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From: "osumi.takamichi@fujitsu.com" <osumi.takamichi@fujitsu.com>
To: 'Simon Riggs' <simon.riggs@enterprisedb.com>, Amit Kapila <amit.kapila16@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>, Peter Smith <smithpb2250@gmail.com>, Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Markus Wanner <markus.wanner@enterprisedb.com>
Date: 2021-06-18T08:55:17Z
Lists: pgsql-hackers

Attachments

On  Friday, June 18, 2021 11:41 AM osumi.takamichi@fujitsu.com <osumi.takamichi@fujitsu.com> wrote:
> On Thursday, June 17, 2021 10:34 PM Simon Riggs
> <simon.riggs@enterprisedb.com> wrote:
> > On Thu, Jun 17, 2021 at 12:57 PM Amit Kapila <amit.kapila16@gmail.com>
> > wrote:
> > > On Thu, Jun 17, 2021 at 4:27 PM Amit Kapila
> > > <amit.kapila16@gmail.com>
> > wrote:
> > > >
> > > > On Thu, Jun 17, 2021 at 8:41 AM osumi.takamichi@fujitsu.com
> > > > <osumi.takamichi@fujitsu.com> wrote:
> > > >
> > > > Pushed!
> > > >
> > > [Responding to Simon's comments]
> > >
> > > > If LOCK and TRUNCATE is advised against on all user catalog
> > > > tables, why would CLUSTER only apply to pg_class? Surely its
> > > > locking level is the
> > same as LOCK?
> > > >
> > >
> > > Cluster will also apply to all user catalog tables. I think we can
> > > extend it slightly as we have mentioned for Lock.
> >
> > OK, good.
> >
> > > > The use of "[user]" isn't fully explained, so it might not be
> > > > clear that this applies to both Postgres catalog tables and any
> > > > user tables that
> > have been nominated as catalogs. Probably worth linking to the
> "Capabilities"
> > section to explain.
> > > >
> > >
> > > Sounds reasonable.
> Simon, I appreciate your suggestions and yes, if the user catalog table is
> referenced by the output plugin, it can be another cause of the deadlock.
> 
> I'm going to post the patch for the those two changes, accordingly.
Hi, I've made the patch-set to cover the discussion above for all-supported versions.
Please have a look at those.


Best Regards,
	Takamichi Osumi

Commits

  1. Doc: Update caveats in synchronous logical replication.

  2. Document a few caveats in synchronous logical replication.

  3. Update the docs and comments for decoding of prepared xacts.

  4. Allow decoding at prepare time in ReorderBuffer.

  5. Documentation for logical decoding.