Horton

Re: generic plans and "initial" pruning

Alexander Law <exclusion@gmail.com>

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From: Alexander Lakhin <exclusion@gmail.com>
To: Amit Langote <amitlangote09@gmail.com>, Tomas Vondra <tomas@vondra.me>
Cc: Robert Haas <robertmhaas@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Andres Freund <andres@anarazel.de>, Daniel Gustafsson <daniel@yesql.se>, David Rowley <dgrowleyml@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Thom Brown <thom@linux.com>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2025-02-22T15:00:01Z
Lists: pgsql-hackers 
Hello Amit,

21.02.2025 05:40, Amit Langote wrote:
> I pushed the final piece yesterday.

Please look at new error, produced by the following script,
starting from 525392d57:
CREATE TABLE t(id int) PARTITION BY RANGE (id);
CREATE INDEX idx on t(id);
CREATE TABLE tp_1 PARTITION OF t FOR VALUES FROM (10) TO (20);
CREATE TABLE tp_2 PARTITION OF t FOR VALUES FROM (20) TO (30) PARTITION BY RANGE(id);
CREATE TABLE tp_2_1 PARTITION OF tp_2 FOR VALUES FROM (21) to (22);
CREATE TABLE tp_2_2 PARTITION OF tp_2 FOR VALUES FROM (22) to (23);
CREATE FUNCTION stable_one() RETURNS INT AS $$ BEGIN RETURN 1; END; $$ LANGUAGE plpgsql STABLE;

SELECT min(id) OVER (PARTITION BY id ORDER BY id) FROM t WHERE id >= stable_one();

ERROR:  XX000: trying to open a pruned relation
LOCATION:  ExecGetRangeTableRelation, execUtils.c:830

This issue was discovered with SQLsmith.

Best regards,
Alexander Lakhin
Neon (https://neon.tech)

Commits

  1. Stamp 19beta1.

  2. Revert "Don't lock partitions pruned by initial pruning"

  3. Ensure first ModifyTable rel initialized if all are pruned

  4. Fix bug in cbc127917 to handle nested Append correctly

  5. Remove unstable test suite added by 525392d57

  6. Don't lock partitions pruned by initial pruning

  7. Fix an oversight in cbc127917 to handle MERGE correctly

  8. Track unpruned relids to avoid processing pruned relations

  9. Perform runtime initial pruning outside ExecInitNode()

  10. Move PartitionPruneInfo out of plan nodes into PlannedStmt

  11. Fix setrefs.c's failure to do expression processing on prune steps.

  12. Remove obsolete executor cleanup code

  13. Revert "Move PartitionPruneInfo out of plan nodes into PlannedStmt"

  14. Move PartitioPruneInfo out of plan nodes into PlannedStmt

  15. Refactor and cleanup runtime partition prune code a little

  16. Remove some unnecessary fields from Plan trees.

  17. Remove more redundant relation locking during executor startup.

  18. Shut down Gather's children before shutting down Gather itself.