Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Dmitry Koval <d.koval@postgrespro.ru>, Alexander Lakhin <exclusion@gmail.com>, pgsql-hackers@lists.postgresql.org, Tomas Vondra <tomas.vondra@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: 2024-05-08T21:37:46Z
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. Adjust errcode in checkPartition()

  2. Fix usage of palloc() in MERGE/SPLIT PARTITION(s) code

  3. Implement ALTER TABLE ... SPLIT PARTITION ... command

  4. Implement ALTER TABLE ... MERGE PARTITIONS ... command

  5. Calculate agglevelsup correctly when Aggref contains a CTE.

  6. Use PqMsg_* macros in applyparallelworker.c.

  7. Restrict psql meta-commands in plain-text dumps.

  8. Ensure we have a snapshot when updating various system catalogs.

  9. Use specific collation where needed in new test

  10. Expand virtual generated columns in the planner

  11. Virtual generated columns

  12. Define PG_LOGICAL_DIR for path pg_logical/ in data folder

  13. Revert support for ALTER TABLE ... MERGE/SPLIT PARTITION(S) commands

  14. Avoid repeated table name lookups in createPartitionTable()

  15. Provide deterministic order for catalog queries in partition_split.sql

  16. Don't copy extended statistics during MERGE/SPLIT partition operations

  17. Fix the name collision detection in MERGE/SPLIT partition operations

  18. Fix regression tests conflict in 3ca43dbbb6

  19. Add permission check for MERGE/SPLIT partition operations

  20. Fix one more portability shortcoming in new test_pg_dump test.

  21. Inherit parent's AM for partition MERGE/SPLIT operations

  22. Add tab completion for partition MERGE/SPLIT operations

  23. Rename tables in tests of partition MERGE/SPLIT operations

  24. Make new partitions with parent's persistence during MERGE/SPLIT

  25. Document the way partition MERGE/SPLIT operations create new partitions

  26. Change the way ATExecMergePartitions() handles the name collision

  27. Grammar fixes for split/merge partitions code

  28. Checks for ALTER TABLE ... SPLIT/MERGE PARTITIONS ... commands

  29. Fix some grammer errors from error messages and codes comments

  30. Support TZ and OF format codes in to_timestamp().

  31. Support identity columns in partitioned tables

  32. Fix indentation in twophase.c

  33. Fix corner-case planner failure for MERGE.

  34. Doc: fix documentation example for bytea hex output format.

  35. Avoid repeated name lookups during table and index DDL.

On Wed, May 08, 2024 at 09:00:10PM +0300, Alexander Korotkov wrote:
> On Fri, May 3, 2024 at 4:32 PM Alexander Korotkov <aekorotkov@gmail.com> wrote:
> > On Fri, May 3, 2024 at 4:23 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> > > On Wed, May 01, 2024 at 10:51:24PM +0300, Dmitry Koval wrote:
> > > > 30.04.2024 23:15, Justin Pryzby пишет:
> > > > > Is this issue already fixed ?
> > > > > I wasn't able to reproduce it.  Maybe it only happened with earlier
> > > > > patch versions applied ?
> > > >
> > > > I think this was fixed in commit [1].
> > > >
> > > > [1] https://github.com/postgres/postgres/commit/fcf80c5d5f0f3787e70fca8fd029d2e08a923f91
> > >
> > > I tried to reproduce it at fcf80c5d5f~, but couldn't.
> > > I don't see how that patch would fix it anyway.
> > > I'm hoping Alexander can confirm what happened.
> >
> > This problem is only relevant for an old version of fix [1], which
> > overrides schemas for new partitions.  That version was never
> > committed.
> 
> Here are the patches.
> 0002 Skips copying extended statistics while creating new partitions in MERGE/SPLIT
> 
> For 0002 I'd like to hear some feedback on wordings used in docs and comments.

commit message:

Currenlty => Currently
partiions => partitios
copying => by copying

> However, parent's table extended statistics already covers all its
> children.

=> That's the wrong explanation.  It's not that "stats on the parent
table cover its children".  It's that there are two types of stats:
stats for the "table hierarchy" and stats for the individual table.
That's true for single-column stats as well as for extended stats.
In both cases, that's indicated by the inh flag in the code and in the
catalog.

The right explanation is that extended stats on partitioned tables are
not similar to indexes.  Indexes on parent table are nothing other than
a mechanism to create indexes on the child tables.  That's not true for
stats.

See also my prior messages
ZiJW1g2nbQs9ekwK@pryzbyj2023
Zi5Msg74C61DjJKW@pryzbyj2023

I think EXCLUDE IDENTITY can/should now also be removed - see 509199587.
I'm not able to reproduce that problem anyway, even before that...

-- 
Justin