Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Justin Pryzby <pryzby@telsasoft.com>

From: Justin Pryzby <pryzby@telsasoft.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Dmitry Koval <d.koval@postgrespro.ru>, Alexander Lakhin <exclusion@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, pgsql-hackers@lists.postgresql.org
Date: 2024-04-28T14:54:16Z
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 Sun, Apr 28, 2024 at 08:18:42AM -0500, Justin Pryzby wrote:
> > I will explore this.  Do we copy extended stats when we do CREATE
> > TABLE ... PARTITION OF?  I think we need to do the same here.
> 
> Right, they're not copied because an extended stats objs on the parent
> does something different than putting stats objects on each child.
> I've convinced myself that it's wrong to copy the parent's stats obj.
> If someone wants stats objects on each child, they'll have to handle
> them specially after MERGE/SPLIT, just as they would for per-child
> defaults/constraints/etc.

I dug up this thread, in which the idea of copying extended stats from
parent to child was considered some 6 years ago, but never implemented;
for consistency, MERGE/SPLIT shouldn't copy extended stats, either.

https://www.postgresql.org/message-id/20180305195750.aecbpihhcvuskzba%40alvherre.pgsql

-- 
Justin