Horton

Re: New strategies for freezing, advancing relfrozenxid early

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: John Naylor <john.naylor@enterprisedb.com>
Cc: Andres Freund <andres@anarazel.de>, Jeff Davis <pgsql@j-davis.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2023-01-26T04:36:11Z
Lists: pgsql-hackers 
On Wed, Jan 25, 2023 at 8:12 PM John Naylor
<john.naylor@enterprisedb.com> wrote:
> That was followed by several paragraphs that never got around to explaining why table size should drive freezing strategy.

You were talking about the system level view of freeze debt, and how
the table view might not be a sufficient proxy for that. What does
that have to do with anything that we've discussed on this thread
recently?

> Review is a feedback mechanism alerting the patch author to possible problems. Listening to feedback is like vacuum, in a way: If it hurts, you're not doing it enough.

An elegant analogy.

-- 
Peter Geoghegan

Commits

  1. Revert "Add eager and lazy freezing strategies to VACUUM."

  2. Add eager and lazy freezing strategies to VACUUM.

  3. Refine the definition of page-level freezing.

  4. Avoid special XID snapshotConflictHorizon values.

  5. Add page-level freezing to VACUUM.

  6. Remove overzealous MultiXact freeze assertion.

  7. Refactor how VACUUM passes around its XID cutoffs.

  8. Deduplicate freeze plans in freeze WAL records.

  9. Set relfrozenxid to oldest extant XID seen by VACUUM.

  10. Only skip pages marked as clean in the visibility map, if the last 32

  11. Add vacuum_freeze_table_age GUC option, to control when VACUUM should