Horton

Re: generic plans and "initial" pruning

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Amit Langote <amitlangote09@gmail.com>
Cc: David Rowley <dgrowleyml@gmail.com>, Robert Haas <robertmhaas@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2022-04-01T03:45:45Z
Lists: pgsql-hackers 
Amit Langote <amitlangote09@gmail.com> writes:
> On Fri, Apr 1, 2022 at 10:32 AM David Rowley <dgrowleyml@gmail.com> wrote:
>> 1. You've changed the signature of various functions by adding
>> ExecLockRelsInfo *execlockrelsinfo.  I'm wondering why you didn't just
>> put the ExecLockRelsInfo as a new field in PlannedStmt?

> I'm worried about that churn myself and did consider this idea, though
> I couldn't shake the feeling that it's maybe wrong to put something in
> PlannedStmt that the planner itself doesn't produce.

PlannedStmt is part of the plan tree, which MUST be read-only to
the executor.  This is not negotiable.  However, there's other
places that this data could be put, such as QueryDesc.
Or for that matter, couldn't the data structure be created by
the planner?  (It looks like David is proposing exactly that
further down.)

			regards, tom lane

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.