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: 2021-06-18T02:40:48Z
Lists: pgsql-hackers 
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.


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.