Horton

Re: Berserk Autovacuum (let's save next Mandrill)

David Rowley <dgrowleyml@gmail.com>

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From: David Rowley <dgrowleyml@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, Laurenz Albe <laurenz.albe@cybertec.at>, Andres Freund <andres@anarazel.de>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Justin Pryzby <pryzby@telsasoft.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Darafei Komяpa Praliaskouski <me@komzpa.net>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Michael Banck <mbanck@gmx.net>
Date: 2020-04-02T20:49:14Z
Lists: pgsql-hackers 
On Fri, 3 Apr 2020 at 04:46, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> I wrote:
> > I'd be inclined to undo what you did in favor of initializing the
> > test tables to contain significantly different numbers of rows,
> > because that would (a) achieve plan stability more directly,
> > and (b) demonstrate that the planner is actually ordering the
> > tables by cost correctly.  Maybe somewhere else we have a test
> > that is verifying (b), but these test cases abysmally fail to
> > check that point.
>
> Concretely, I suggest the attached, which replaces the autovac disables
> with adjusting partition boundaries so that the partitions contain
> different numbers of rows.

I've looked over this and I agree that it's a better solution to the problem.

I'm happy for you to go ahead on this.

David

Commits

  1. Further improve stability fix for partition_aggregate test.

  2. Improve stability fix for partition_aggregate test.

  3. Attempt to stabilize partitionwise_aggregate test

  4. Fix race condition in statext_store().

  5. Attempt to fix unstable regression tests, take 2

  6. Attempt to fix unstable regression tests

  7. Trigger autovacuum based on number of INSERTs

  8. Fix upper limit for vacuum_cleanup_index_scale_factor