Horton

Re: Extended Statistics set/restore/clear functions.

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Chao Li <li.evan.chao@gmail.com>
Cc: Corey Huinker <corey.huinker@gmail.com>, jian he <jian.universality@gmail.com>, Tomas Vondra <tomas@vondra.me>, pgsql-hackers@lists.postgresql.org, tgl@sss.pgh.pa.us
Date: 2025-11-25T10:06:09Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add test doing some cloning of extended statistics data

  2. Add test for pg_restore_extended_stats() with multiranges

  3. Add support for "mcv" in pg_restore_extended_stats()

  4. Include extended statistics data in pg_dump

  5. Add support for "dependencies" in pg_restore_extended_stats()

  6. Add test for MAINTAIN permission with pg_restore_extended_stats()

  7. Add pg_restore_extended_stats()

  8. Add routine to free MCVList

  9. Improve pg_clear_extended_stats() with incorrect relation/stats combination

  10. Add pg_clear_extended_stats()

  11. Introduce routines to validate and free MVNDistinct and MVDependencies

  12. Fix typo in stat_utils.c

  13. Move attribute statistics functions to stat_utils.c

  14. Improve error messages of input functions for pg_dependencies and pg_ndistinct

  15. Improve test output of extended statistics for ndistinct and dependencies

  16. Fix some compiler warnings

  17. Add input function for data type pg_dependencies

  18. Add input function for data type pg_ndistinct

  19. Rework output format of pg_dependencies

  20. Rework output format of pg_ndistinct

  21. Fix comments of output routines for pg_ndistinct and pg_dependencies

  22. Move code specific to pg_dependencies to new file

  23. Move code specific to pg_ndistinct to new file

  24. Document some structures in attribute_stats.c

  25. Fix FATAL message for invalid recovery timeline at beginning of recovery

On Tue, Nov 25, 2025 at 04:59:28PM +0800, Chao Li wrote:
> I don’t see any of my comments are addressed in v18.

Sorry about that, I thought that v17 was addressing these.  I have
reviewed your latest email posted here:
https://www.postgresql.org/message-id/2C8A20C7-4E08-41F4-B30E-AD9F8B007AE5@gmail.com

And well, this presents a bunch of issues I have already fixed (break
after return, one error message incorrect, some descriptions).  The
comments on top of the functions are actually true as they stand (aka
ndistinct_array_end() fails if we don't have an array).  There is no
need to reset state vars upon a JSON_SEM_ACTION_FAILED AFAIK.
Finally, the consts are non-appealing for me for functions that are
internally used in these files.  And forgot one:
valid_subsequent_attnum()'s duplication is actually adapted IMO, the
argument lists could have different assumptions depending on the type
of extended stats we are dealing with.  I did not check the comments
for 0003~0005.  Perhaps you are right that these need adjustments.

Thanks,
--
Michael