Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Jonathan S. Katz <jkatz@postgresql.org>

From: "Jonathan S. Katz" <jkatz@postgresql.org>
To: Robert Haas <robertmhaas@gmail.com>, Alexander Korotkov <aekorotkov@gmail.com>
Cc: Pavel Borisov <pashkin.elfe@gmail.com>, Dmitry Koval <d.koval@postgrespro.ru>, Noah Misch <noah@leadboat.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-08-22T16:43:22Z
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 8/22/24 12:33 PM, Robert Haas wrote:

> I think it is very unlikely that the problems mentioned above are the
> only ones. They're just what I found in an hour or two of testing.
> Even if they were, we're probably too close to release to be rushing
> out last minute fixes to multiple unanticipated security problems. But
> because of the design that was chosen here, I think there is probably
> more stuff here that is not right, some of which is security relevant
> and some of which is just a question of whether we're really getting
> the behavior that we want. And I don't think we can fix all that
> without either a very large number of grotty hacks similar to the one
> installed by 04158e7fa37c2dda9c3421ca922d02807b86df19, or a complete
> redesign of the feature. I believe the latter is probably a wiser
> course of action.

I can't comment on the design as much, but from a release standpoint, 
but security concerns this close to the RC/GA period do concern me.

Applying the lessons from PG15 + SQL/JSON where we (and I'll own that I 
was the one who pushed hard to include it) let it stay too long when it 
should have been reverted, I think we should take more time to work on 
this feature, revert it for PG17, and target it for PG18.

I understand it's disappointing to do a late revert of a feature, but I 
think it's better to be safer, particularly if we believe there's a an 
elevated risk of releasing something with vulnerabilities. As we saw 
with SQL/JSON, this we'll give us more time to come up with design we 
agree with, further test, and then promote as part of PG18.

Thanks,

Jonathan