Re: New IndexAM API controlling index vacuum strategies

Peter Geoghegan <pg@bowt.ie>

From: Peter Geoghegan <pg@bowt.ie>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Matthias van de Meent <boekewurm+postgres@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Noah Misch <noah@leadboat.com>
Date: 2021-04-13T19:59:03Z
Lists: pgsql-hackers
On Mon, Apr 12, 2021 at 11:05 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> I realized that when the failsafe is triggered, we don't bypass heap
> truncation that is performed before updating relfrozenxid. I think
> it's better to bypass it too. What do you think?

I agree. Bypassing heap truncation is exactly the kind of thing that
risks adding significant, unpredictable delay at a time when we need
to advance relfrozenxid as quickly as possible.

I pushed a trivial commit that makes the failsafe bypass heap
truncation as well just now.

Thanks
-- 
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).