Horton

Re: Statistics Import and Export

Magnus Hagander <magnus@hagander.net>

View thread
From: Magnus Hagander <magnus@hagander.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Bruce Momjian <bruce@momjian.us>, Nathan Bossart <nathandbossart@gmail.com>, Corey Huinker <corey.huinker@gmail.com>, Jeff Davis <pgsql@j-davis.com>, jian he <jian.universality@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Stephen Frost <sfrost@snowman.net>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Peter Smith <smithpb2250@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-11-27T18:13:04Z
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. Change pg_dump default for statistics export.

  2. pg_dump: Adjust reltuples from 0 to -1 for dumps of older versions.

  3. vacuumdb: Don't skip empty relations in --missing-stats-only mode.

  4. pg_dump: Fix query for gathering attribute stats on older versions.

  5. Prevent redeclaration of typedef TocEntry.

  6. Remove unused function parameters in pg_backup_archiver.c.

  7. pg_dump: Retrieve attribute statistics in batches.

  8. pg_dump: Reduce memory usage of dumps with statistics.

  9. Skip second WriteToc() call for custom-format dumps without data.

  10. Add relallfrozen to pg_dump statistics.

  11. Matview statistics depend on matview data.

  12. Add pg_dump --with-{schema|data|statistics} options.

  13. Stats: use schemaname/relname instead of regclass.

  14. CREATE INDEX: do update index stats if autovacuum=off.

  15. Don't convert to and from floats in pg_dump.

  16. CREATE INDEX: don't update table stats if autovacuum=off.

  17. Organize and deduplicate statistics import tests.

  18. Address stats export review comments.

  19. Address stats import review comments.

  20. Add relallfrozen to pg_class

  21. Fix pg_strtof() to not crash on NULL endptr.

  22. Use attnum to identify index columns in pg_restore_attribute_stats().

  23. pg_dump: prepare attribute stats query.

  24. Avoid unnecessary relation stats query in pg_dump.

  25. Remove redundant pg_set_*_stats() variants.

  26. Do not use in-place updates for statistics import.

  27. Fix confusion about data type of pg_class.relpages and relallvisible.

  28. Documentation fixups for dumping statistics.

  29. Trial fix for old cross-version upgrades.

  30. Transfer statistics during pg_upgrade.

  31. Lock table in ShareUpdateExclusive when importing index stats.

  32. Use in-place updates for pg_restore_relation_stats().

  33. Improve error message for replication of generated columns.

  34. pg_dump: Add dumpSchema and dumpData derivative flags.

  35. Disallow modifying statistics on system columns.

  36. Add missing CommandCounterIncrement() in stats import functions.

  37. Add functions pg_restore_relation_stats(), pg_restore_attribute_stats().

  38. Documentation fixup.

  39. Add functions pg_set_attribute_stats() and pg_clear_attribute_stats().

  40. Change pg_*_relation_stats() functions to return type to void.

  41. Disable autovacuum for tables in stats import tests.

  42. Allow pg_set_relation_stats() to set relpages to -1.

  43. Fixup for pg_set_relation_stats().

  44. Create functions pg_set_relation_stats, pg_clear_relation_stats.

  45. Add memory/disk usage for Window aggregate nodes in EXPLAIN.

  46. Improve performance of dumpSequenceData().

  47. Add INJECTION_POINT_CACHED() to run injection points directly from cache

  48. Improve performance of binary_upgrade_set_pg_class_oids().

  49. Improve assertion in mdwritev()

  50. CREATE INDEX: do not update stats during binary upgrade.

  51. Redefine pg_class.reltuples to be -1 before the first VACUUM or ANALYZE.

On Wed, Nov 27, 2024, 17:44 Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> > On 2024-Nov-27, Bruce Momjian wrote:
> >> Would there be a default?
>
> > There would be no default.  Running with no option given would raise an
> > error.  The point is: you want to break scripts currently running
> > --analyze-in-stages so that they can make a choice of which of these two
> > modes to run.  Your proposal (as I understand it) is to remove the
> > --analyze-in-stages option and add two other options.  My proposal is to
> > keep --analyze-in-stages, but require it to have a specifier of which
> > mode to run.  Both achieve what you want, but I think mine achieves it
> > in a cleaner way.
>
> I do not like the idea of breaking existing upgrade scripts,
> especially not by requiring them to use a parameter that older
> vacuumdb versions will reject.  That makes it impossible to have a
> script that is version independent.  I really doubt that there is any
> usability improvement to be had here that's worth that.
>
> How about causing "--analyze-in-stages" (as currently spelled) to
> be a no-op?  We could keep the behavior available under some other
> name.


If we're doing that we might as well make this be the "when missing".

If we make it do nothing then we surprise the users of it today just as
much as we do if we make it "when missing". And it would actually solve the
problem for the others. But the point was that people didn't like silently
changing the behavior of the existing parameter - and making it a noop
would change it even more.

/Magnus


>