Horton

Re: generic plans and "initial" pruning

Amit Langote <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Robert Haas <robertmhaas@gmail.com>, Jacob Champion <jchampion@timescale.com>, David Rowley <dgrowleyml@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2022-12-09T08:26:59Z
Lists: pgsql-hackers 
Thanks for the review.

On Wed, Dec 7, 2022 at 4:00 AM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> I find the API of GetCachedPlans a little weird after this patch.  I
> think it may be better to have it return a pointer of a new struct --
> one that contains both the CachedPlan pointer and the list of pruning
> results.  (As I understand, the sole caller that isn't interested in the
> pruning results, SPI_plan_get_cached_plan, can be explained by the fact
> that it knows there won't be any.  So I don't think we need to worry
> about this case?)

David, in his Apr 7 reply on this thread, also sounded to suggest
something similar.

Hmm, I was / am not so sure if GetCachedPlan() should return something
that is not CachedPlan.  An idea I had today was to replace the
part_prune_results_list output List parameter with, say,
QueryInitPruningResult, or something like that and put the current
list into that struct.   Was looking at QueryEnvironment to come up
with *that* name.  Any thoughts?

> And I think you should make that struct also be the last argument of
> PortalDefineQuery, so you don't need the separate
> PortalStorePartitionPruneResults function -- because as far as I can
> tell, the callers that pass a non-NULL pointer there are the exactly
> same that later call PortalStorePartitionPruneResults.

Yes, it would be better to not need PortalStorePartitionPruneResults.


--
Thanks, Amit Langote
EDB: http://www.enterprisedb.com

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.