Horton

Re: Extended Statistics set/restore/clear functions.

jian he <jian.universality@gmail.com>

View thread
From: jian he <jian.universality@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Corey Huinker <corey.huinker@gmail.com>, Tomas Vondra <tomas@vondra.me>, pgsql-hackers@lists.postgresql.org, tgl@sss.pgh.pa.us
Date: 2025-11-11T15:14:34Z
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 11, 2025 at 4:07 PM Michael Paquier <michael@paquier.xyz> wrote:
> I've rebased the full set using the new structure.  0001~0004 are
> clean.  0005~ need more work and analysis, but that's a start.
hi.

diff --git a/doc/src/sgml/perform.sgml b/doc/src/sgml/perform.sgml
index 106583fb2965..e0e9f0468cb8 100644
--- a/doc/src/sgml/perform.sgml
+++ b/doc/src/sgml/perform.sgml
@@ -1579,9 +1579,39 @@ ANALYZE zipcodes;
 SELECT stxkeys AS k, stxdndistinct AS nd
   FROM pg_statistic_ext join pg_statistic_ext_data on (oid = stxoid)
   WHERE stxname = 'stts2';
--[ RECORD 1 ]------------------------------------------------------&zwsp;--
+-[ RECORD 1 ]-------------------
 k  | 1 2 5
-nd | {"1, 2": 33178, "1, 5": 33178, "2, 5": 27435, "1, 2, 5": 33178}
+nd | [                          +
+   |     {                      +
+   |         "ndistinct": 33178,+
+   |         "attributes": [    +
+   |             1,             +
+   |             2              +
+   |         ]                  +
+   |     },                     +

If you not specify as
 SELECT stxkeys AS k, stxdndistinct AS nd
   FROM pg_statistic_ext join pg_statistic_ext_data on (oid = stxoid)
   WHERE stxname = 'stts2' \gx
then it won't look like ``-[ RECORD 1 ]``.

I tried the dummy data, the above query, the nd column data look like

[{"attributes": [1, 2], "ndistinct": 2} .....
which does not look like the above.

So I guess the query in doc/src/sgml/perform.sgml would be:

SELECT stxkeys AS k, jsonb_pretty(d.stxdndistinct::text::jsonb) AS nd
FROM pg_statistic_ext join pg_statistic_ext_data d on (oid = d.stxoid)
WHERE stxname = 'stts2' \gx

per related thread, the word "join" needs uppercase?


--
jian
https://www.enterprisedb.com/