Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Alexander Korotkov <aekorotkov@gmail.com>

View thread
From: Alexander Korotkov <aekorotkov@gmail.com>
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2024-03-30T12:40:43Z
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.

Attachments

Hi, Dmitry!

Thank you for your feedback!

On Wed, Mar 27, 2024 at 10:18 PM Dmitry Koval <d.koval@postgrespro.ru> wrote:
>  > I've fixed that by skipping a copy of the identity of another
>  > partition (remove CREATE_TABLE_LIKE_IDENTITY from
>  > TableLikeClause.options).
>
> Thanks for correction!
> Probably I should have looked at the code more closely after commit [1].
> I'm also very glad that situation [2] was reproduced.
>
>  > When merging partitions you're creating a merged partition like the
>  > parent table.   But when splitting a partition you're creating new
>  > partitions like the partition being split.  What motivates this
>  > difference?
>
> When splitting a partition, I planned to set parameters for each of the
> new partitions (for example, tablespace parameter).
> It would make sense if we want to transfer part of the data of splitting
> partition to a slower (archive) storage device.
> Right now I haven't seen any interest in this functionality, so it
> hasn't been implemented yet. But I think this will be needed in the future.

OK, I've changed the code to use the parent table as a template for
new partitions in split case.  So, now it's the same in both split and
merge cases.

I also added a special note into docs about ACCESS EXCLUSIVE lock,
because I believe that's a significant limitation for usage of this
functionality.

I think 0001, 0002 and 0003 could be considered for pg17.  I will
continue reviewing them.

0004 might require more work.  I didn't rebase it for now.  I suggest
we can rebase it later and consider for pg18.

------
Regards,
Alexander Korotkov