Horton

Re: Add SPLIT PARTITION/MERGE PARTITIONS commands

Alexander Lakhin <exclusion@gmail.com>

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From: Alexander Lakhin <exclusion@gmail.com>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Dmitry Koval <d.koval@postgrespro.ru>, pgsql-hackers@lists.postgresql.org
Date: 2024-04-08T04:00:00Z
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.

08.04.2024 01:15, Alexander Korotkov wrote:
> Thank you for spotting this.  This seems like a missing check.  I'm
> going to get a closer look at this tomorrow.
>

Thanks!

There is also an anomaly with the MERGE command:
CREATE TABLE t1 (i int, a int, b int, c int) PARTITION BY RANGE (a, b);
CREATE TABLE t1p1 PARTITION OF t1 FOR VALUES FROM (1, 1) TO (1, 2);

CREATE TABLE t2 (i int, t text) PARTITION BY RANGE (t);
CREATE TABLE t2pa PARTITION OF t2 FOR VALUES FROM ('A') TO ('C');

CREATE TABLE t3 (i int, t text);

ALTER TABLE t2 MERGE PARTITIONS (t1p1, t2pa, t3) INTO t2p;

leads to:
ERROR:  partition bound for relation "t3" is null
WARNING:  problem in alloc set PortalContext: detected write past chunk end in block 0x55f1ef42f820, chunk 0x55f1ef42ff40
WARNING:  problem in alloc set PortalContext: detected write past chunk end in block 0x55f1ef42f820, chunk 0x55f1ef42ff40

(I'm also not sure that the error message is clear enough (can't we say
"relation X is not a partition of relation Y" in this context, as in
MarkInheritDetached(), for example?).)

Whilst with
ALTER TABLE t2 MERGE PARTITIONS (t1p1, t2pa) INTO t2p;

I get:
Program terminated with signal SIGSEGV, Segmentation fault.

#0  pg_detoast_datum_packed (datum=0x1) at fmgr.c:1866
1866            if (VARATT_IS_COMPRESSED(datum) || VARATT_IS_EXTERNAL(datum))
(gdb) bt
#0  pg_detoast_datum_packed (datum=0x1) at fmgr.c:1866
#1  0x000055d77d00fde2 in bttextcmp (...) at ../../../../src/include/postgres.h:314
#2  0x000055d77d03fa27 in FunctionCall2Coll (...) at fmgr.c:1161
#3  0x000055d77ce1572f in partition_rbound_cmp (...) at partbounds.c:3525
#4  0x000055d77ce157b9 in qsort_partition_rbound_cmp (...) at partbounds.c:3816
#5  0x000055d77d0982ef in qsort_arg (...) at ../../src/include/lib/sort_template.h:316
#6  0x000055d77ce1d109 in calculate_partition_bound_for_merge (...) at partbounds.c:5786
#7  0x000055d77cc24b2b in transformPartitionCmdForMerge (...) at parse_utilcmd.c:3524
#8  0x000055d77cc2b555 in transformAlterTableStmt (...) at parse_utilcmd.c:3812
#9  0x000055d77ccab17c in ATParseTransformCmd (...) at tablecmds.c:5650
#10 0x000055d77ccafd09 in ATExecCmd (...) at tablecmds.c:5589
...

Best regards,
Alexander