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Re: New IndexAM API controlling index vacuum strategies

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Noah Misch <noah@leadboat.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>
Date: 2021-04-05T23:53:58Z
Lists: pgsql-hackers 
On Mon, Apr 5, 2021 at 4:29 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Peter Geoghegan <pg@bowt.ie> writes:
> > Do you think that it's okay that we rely on the propagation of global
> > state to parallel workers on Postgres 13? Don't we need something like
> > my fixup commit 49f49def on Postgres 13 as well? At least for the
> > EXEC_BACKEND case, I think.
>
> Uh ... *what* propagation of global state to parallel workers?  Workers
> fork off from the postmaster, not from their leader process.
>
> (I note that morepork is still failing.  The other ones didn't report
> in yet.)

Evidently my fixup commit 49f49def was written in way too much of a
panic. I'm going to push a new fix shortly. This will make workers do
their own GetAccessStrategy(BAS_VACUUM), just to get the buildfarm
green.

REL_13_STABLE will need to be considered separately. I still haven't
figured out how this ever appeared to work for this long. The
vac_strategy/bstrategy state simply wasn't propagated at all.

-- 
Peter Geoghegan

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Don't truncate heap when VACUUM's failsafe is in effect.

  2. Teach VACUUM to bypass unnecessary index vacuuming.

  3. Add wraparound failsafe to VACUUM.

  4. Truncate line pointer array during VACUUM.

  5. Remove tupgone special case from vacuumlazy.c.

  6. Refactor lazy_scan_heap() loop.

  7. Propagate parallel VACUUM's buffer access strategy.

  8. Simplify state managed by VACUUM.

  9. Notice that heap page has dead items during VACUUM.

  10. Adjust lazy_scan_heap() accounting comments.

  11. Use full 64-bit XID for checking if a deleted GiST page is old enough.

  12. Fix some problems with VACUUM (INDEX_CLEANUP FALSE).