Horton

Re: BUG #17255: Server crashes in index_delete_sort_cmp() due to race condition with vacuum

Peter Geoghegan <pg@bowt.ie>

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From: Peter Geoghegan <pg@bowt.ie>
To: Andres Freund <andres@anarazel.de>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Alexander Lakhin <exclusion@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Date: 2021-11-11T20:40:03Z
Lists: pgsql-bugs 
On Thu, Nov 11, 2021 at 12:25 PM Peter Geoghegan <pg@bowt.ie> wrote:
> Can you at least move the GlobalVisTestFor() call back? Move it from
> lazy_scan_heap() to the point right before we call lazy_scan_heap(),
> from heap_vacuum_rel()? That still seems like a big improvement, while
> obviously having no real side-effects.

I imagine that you'd also move vistest into the main state struct
(vacrel) -- it could go right next to the existing OldestXmin field in
vacrel/LVRelState. These two things are too similar to not put next to
each other, and address together. We never use one without using the
other (except in heap_page_is_all_visible(), but that's just a
stripped-down version of lazy_scan_prune() anyway, so it shouldn't
count).

-- 
Peter Geoghegan

Commits

  1. vacuumlazy.c: Standardize rel_pages terminology.

  2. vacuumlazy.c: document vistest and OldestXmin.

  3. heap pruning: Only call BufferGetBlockNumber() once.

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

  5. Assert redirect pointers are sensible after heap_page_prune().

  6. Remove tupgone special case from vacuumlazy.c.

  7. Recycle nbtree pages deleted during same VACUUM.

  8. snapshot scalability: Don't compute global horizons while building snapshots.

  9. Refactor heap_page_prune so that instead of changing item states on-the-fly,