Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Alexander Lakhin <exclusion@gmail.com>

View thread
From: Alexander Lakhin <exclusion@gmail.com>
To: Dmitry Koval <d.koval@postgrespro.ru>, Alexander Korotkov <aekorotkov@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-04-30T03:00:00Z
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.

30.04.2024 03:10, Dmitry Koval wrote:
> Hi!
>
> 1.
> 29.04.2024 21:00, Alexander Lakhin wrote:
>> I still wonder, why that constraint (now with a less questionable name) is
>> created during MERGE?
>
> The SPLIT/MERGE PARTITION(S) commands for creating partitions reuse the existing code of CREATE TABLE .. LIKE ... 
> command. A new partition was created with the name "merge-16385-26BCB0-tmp" (since there was an old partition with the 
> same name). The constraint "merge-16385-26BCB0-tmp_i_not_null" was created too together with the partition. 
> Subsequently, the table was renamed, but the constraint was not.
> Now a new partition is immediately created with the correct name (the old partition is renamed).

Maybe I'm doing something wrong, but the following script:
CREATE TABLE t (i int, PRIMARY KEY(i)) PARTITION BY RANGE (i);
CREATE TABLE tp_0 PARTITION OF t FOR VALUES FROM (0) TO (1);
CREATE TABLE tp_1 PARTITION OF t FOR VALUES FROM (1) TO (2);

CREATE TABLE t2 (LIKE t INCLUDING ALL);
CREATE TABLE tp2 (LIKE tp_0 INCLUDING ALL);
creates tables t2, tp2 without not-null constraints.

But after
ALTER TABLE t MERGE PARTITIONS (tp_0, tp_1) INTO tp_0;
I see:
\d+ tp_0
...
Indexes:
     "tp_0_pkey" PRIMARY KEY, btree (i)
Not-null constraints:
     "tp_0_i_not_null" NOT NULL "i"

Best regards,
Alexander