Horton

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

John Naylor <johncnaylorls@gmail.com>

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From: John Naylor <johncnaylorls@gmail.com>
To: Masahiko Sawada <sawada.mshk@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: 2024-03-07T05:55:22Z
Lists: pgsql-hackers 
On Wed, Mar 6, 2024 at 6:59 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> > + /* Find the control object in shared memory */
> > + control = handle;
>
> I think it's mostly because of readability; it makes clear that the
> handle should be castable to dsa_pointer and it's a control object. I
> borrowed it from dshash_attach().

I find that a bit strange, but I went ahead and kept it.



On Wed, Mar 6, 2024 at 9:13 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:

> The 0001 patch looks good to me. I have some minor comments:

> +PGFILEDESC = "test_radixtree - test code for src/backend/lib/radixtree.c"
> +
>
> "src/backend/lib/radixtree.c" should be updated to
> "src/include/lib/radixtree.h".

Done.

> --- /dev/null
> +++ b/src/test/modules/test_radixtree/README
> @@ -0,0 +1,7 @@
> +test_integerset contains unit tests for testing the integer set implementation
> +in src/backend/lib/integerset.c.
> +
> +The tests verify the correctness of the implementation, but they can also be
> +used as a micro-benchmark.  If you set the 'intset_test_stats' flag in
> +test_integerset.c, the tests will print extra information about execution time
> +and memory usage.
>
> This file is not updated for test_radixtree. I think we can remove it
> as the test cases in test_radixtree are clear.

Done. I pushed this with a few last-minute cosmetic adjustments. This
has been a very long time coming, but we're finally in the home
stretch!

Already, I see sifaka doesn't like this, and I'm looking now...

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