Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Alexander Korotkov <aekorotkov@gmail.com>

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From: Alexander Korotkov <aekorotkov@gmail.com>
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2025-06-03T10:12:28Z
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.

Hi, Dmitry!

On Tue, May 20, 2025 at 1:36 AM Dmitry Koval <d.koval@postgrespro.ru> wrote:
> Changes in patches:
>
> 1) Added usage of SECURITY_RESTRICTED_OPERATION for SPLIT/MERGE
> PARTITION(S) commands.
>
> 2) For SPLIT PARTITION command: new partitions will have the same owner
> as the parent.
>
> 3) For MERGE PARTITIONS command: if merged partitions have different
> owners, an error will be generated.

Some notes to the patch.
1) I think we need explicitly document who is the owner of the new
partition(s).  The documentation for MERGE command says all the merged
partitions should have the same owner.  Good, but also we need to
state that the new partition should have the same owner.  Same to the
SPLIT command.
2) I think we also need to describe what happens not just with
ownership, but with ACLs.  We currently don't do anything to them, so
basically we discard existing ACLs.  It's probably OK, and we could
introduce options for ACL handling later.  But we need to state in the
docs that it's user responsibility to setup ACL on new partition(s).

------
Regards,
Alexander Korotkov
Supabase