Horton

Re: [PoC] Improve dead tuple storage for lazy vacuum

Masahiko Sawada <sawada.mshk@gmail.com>

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From: Masahiko Sawada <sawada.mshk@gmail.com>
To: John Naylor <johncnaylorls@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>, Nathan Bossart <nathandbossart@gmail.com>, Andres Freund <andres@anarazel.de>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Yura Sokolov <y.sokolov@postgrespro.ru>
Date: 2024-03-29T06:05:36Z
Lists: pgsql-hackers 
On Thu, Mar 28, 2024 at 6:15 PM John Naylor <johncnaylorls@gmail.com> wrote:
>
> On Thu, Mar 28, 2024 at 12:55 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> >
> > Pushed the refactoring patch.
> >
> > I've attached the rebased vacuum improvement patch for cfbot. I
> > mentioned in the commit message that this patch eliminates the 1GB
> > limitation.
> >
> > I think the patch is in good shape. Do you have other comments or
> > suggestions, John?
>
> I'll do another pass tomorrow, but first I wanted to get in another
> slightly-challenging in-situ test.

Thanks!

>
> About the "tuples missed" -- I didn't expect contention during this
> test. I believe that's completely unrelated behavior, but wanted to
> mention it anyway, since I found it confusing.

I don't investigate it enough but bgwriter might be related to the contention.

Regards,

-- 
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com

Commits

  1. radixtree: Fix SIGSEGV at update of embeddable value to non-embeddable.

  2. Get rid of anonymous struct

  3. Teach radix tree to embed values at runtime

  4. Teach TID store to skip bitmap for small numbers of offsets

  5. Use bump context for TID bitmaps stored by vacuum

  6. Fix alignment of stack variable

  7. Use TidStore for dead tuple TIDs storage during lazy vacuum.

  8. Rethink create and attach APIs of shared TidStore.

  9. Fix inconsistent function prototypes with function definitions.

  10. Fix a calculation in TidStoreCreate().

  11. Fix potential integer handling issue in radixtree.h.

  12. Add TIDStore, to store sets of TIDs (ItemPointerData) efficiently.

  13. Fix link error for test_radixtree module on Windows

  14. Blind attempt to fix ODR violations

  15. Fix incorrect format specifier for int64

  16. Fix redefinition of typedefs

  17. Add template for adaptive radix tree

  18. Fix signedness error in 9f225e992 for gcc

  19. Introduce helper SIMD functions for small byte arrays

  20. Optimize vacuuming of relations with no indexes.

  21. Add bound check before bsearch() for performance

  22. Allocate consecutive blocks during parallel seqscans