Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

jian he <jian.universality@gmail.com>

View thread
From: jian he <jian.universality@gmail.com>
To: Dmitry Koval <d.koval@postgrespro.ru>
Cc: pgsql-hackers@lists.postgresql.org
Date: 2025-06-24T08:06:56Z
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.

+ /* Sort array of lower bounds. */
+ qsort_arg(lower_bounds, nparts, sizeof(PartitionRangeBound *),
+  qsort_partition_rbound_cmp, (void *) key);
here, we don't need ``(void *)``


+ALTER TABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable>
+    MERGE PARTITIONS (<replaceable
class="parameter">partition_name1</replaceable>, <replaceable
class="parameter">partition_name2</replaceable> [, ...])
+        INTO <replaceable class="parameter">partition_name</replaceable>
In the synopsis section, we can combine the last two lines into one
for better formatting.

after
<varlistentry id="sql-altertable-parms-partition-name">
we can add the following to briefly explain parameters: partition_name1,
partition_name2


     <varlistentry id="sql-altertable-parms-partition-name1">
      <term><replaceable class="parameter">partition_name1</replaceable></term>
      <term><replaceable class="parameter">partition_name2</replaceable></term>
      <listitem>
       <para>
        The names of the tables being merged into the new partition.
       </para>
      </listitem>
     </varlistentry>

What do you think about alternative syntax:
ALTER TABLE tab1 MERGE PARTITION part1 WITH (part2, part3) mentioned in [1].
I think we need to settle this issue before moving forward.
If the current MERGE PARTITION design is finalized, then v48-0001 looks solid.

[1] https://postgr.es/m/CA+TgmoY0=bT_xBP8csR=MFE=FxGE2n2-me2-31jBOgEcLvW7ug@mail.gmail.com