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: 2024-03-06T14:13:17Z
Lists: pgsql-hackers 
On Wed, Mar 6, 2024 at 8:20 PM John Naylor <johncnaylorls@gmail.com> wrote:
>
> On Tue, Mar 5, 2024 at 11:12 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> >
> > > I'd like to push 0001 and 0002 shortly, and then do another sweep over
> > > 0003, with remaining feedback, and get that in so we get some
> > > buildfarm testing before the remaining polishing work on
> > > tidstore/vacuum.
> >
> > Sounds a reasonable plan. 0001 and 0002 look good to me. I'm going to
> > polish tidstore and vacuum patches and update commit messages.
>
> I don't think v66 got a CI run because of vacuumlazy.c bitrot, so I'm
> attaching v67 which fixes that and has some small cosmetic adjustments
> to the template.

Thank you for updating the patch.

> One functional change for debugging build is that
> RT_STATS now prints out the number of leaves. I'll squash and push
> 0001 tomorrow morning unless there are further comments.

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

--- /dev/null
+++ b/src/test/modules/test_radixtree/Makefile
@@ -0,0 +1,23 @@
+# src/test/modules/test_radixtree/Makefile
+
+MODULE_big = test_radixtree
+OBJS = \
+   $(WIN32RES) \
+   test_radixtree.o
+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".

---
--- /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.

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