Horton

Re: Removing more vacuumlazy.c special cases, relfrozenxid optimizations

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Andres Freund <andres@anarazel.de>, Masahiko Sawada <sawada.mshk@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-03-23T20:41:33Z
Lists: pgsql-hackers 
On Wed, Mar 23, 2022 at 3:59 PM Peter Geoghegan <pg@bowt.ie> wrote:
> In other words, since DISABLE_PAGE_SKIPPING doesn't *consistently*
> force lazy_scan_noprune to refuse to process a page on HEAD (it all
> depends on FreezeLimit/vacuum_freeze_min_age), it is logical for
> DISABLE_PAGE_SKIPPING to totally get out of the business of caring
> about that -- better to limit it to caring only about the visibility
> map (by no longer making it force aggressiveness).

It seems to me that if DISABLE_PAGE_SKIPPING doesn't completely
disable skipping pages, we have a problem.

The option isn't named CARE_ABOUT_VISIBILITY_MAP. It's named
DISABLE_PAGE_SKIPPING.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

  1. Have VACUUM warn on relfrozenxid "in the future".

  2. vacuumlazy.c: Further consolidate resource allocation.

  3. Generalize how VACUUM skips all-frozen pages.

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

  5. Doc: Add relfrozenxid Tip to XID wraparound section.

  6. vacuumlazy.c: document vistest and OldestXmin.

  7. Increase hash_mem_multiplier default to 2.0.

  8. Consolidate VACUUM xid cutoff logic.

  9. Add VACUUM instrumentation for scanned pages, relfrozenxid.

  10. Simplify lazy_scan_heap's handling of scanned pages.

  11. Try to stabilize reloptions test, again.

  12. Unify VACUUM VERBOSE and autovacuum logging.

  13. Fix possible HOT corruption when RECENTLY_DEAD changes to DEAD while pruning.

  14. pg_resetxlog: add option to set oldest xid & use by pg_upgrade

  15. Teach VACUUM to bypass unnecessary index vacuuming.

  16. Centralize horizon determination for temp tables, fixing bug due to skew.

  17. pg_surgery: Try to stabilize regression tests.

  18. Add "split after new tuple" nbtree optimization.

  19. Fix bugs in vacuum of shared rels, by keeping their relcache entries current.

  20. Avoid useless truncation attempts during VACUUM.

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

  22. Fix recently-understood problems with handling of XID freezing, particularly