Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2025-05-21T00:35:35Z
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 Mon, May 12, 2025 at 4:31 PM Dmitry Koval <d.koval@postgrespro.ru> wrote:
>
> Hi!
>
> We (with colleagues) discussed further improvements to SPLIT/MERGE
> PARTITION(S). As a result of the discussion, the following answers to
> the questions remained:
>
> 1. Who should be the owner of new partitions (SPLIT PARTITION command)
> if owner of the partition being split is not the same as the current user?
> a) current user (since he is the one who creates new tables);
> b) the owner of the partitioned partition (since it is the owner of the
> table and should continue to own it).

per https://www.postgresql.org/docs/current/sql-altertable.html
"You must own the table to use ALTER TABLE."

That means the current user must own the to be SPLITed partition.
the new partitions owner should be current user (the one who did ALTER TABLE)


> 2. Who should be the owner of the new partition (MERGE PARTITIONS
> command) if the partitions being merged have different owners?
> a) current user (since he is the one who creates new table);
> b) merging of partitions should be forbidden if they have different owners.
>
let say:

alter table whatever_range merge partitions
    ( whatever_range_c, whatever_range_de )
    into whatever_range_cde;

In this case, the current user must own
whatever_range_c and whatever_range_de to perform this operation.
and the current user will be the owner of whatever_range_cde.