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: Alvaro Herrera <alvherre@alvh.no-ip.org>, Robert Haas <robertmhaas@gmail.com>, Jacob Champion <jchampion@timescale.com>, David Rowley <dgrowleyml@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2023-01-20T03:58:36Z
Lists: pgsql-hackers 
Amit Langote <amitlangote09@gmail.com> writes:
> On Fri, Jan 20, 2023 at 12:31 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> It might be possible to incorporate this pointer into PlannedStmt
>> instead of passing it separately.

> Yeah, that would be less churn.  Though, I wonder if you still hold
> that PlannedStmt should not be scribbled upon outside the planner as
> you said upthread [1]?

Well, the whole point of that rule is that the executor can't modify
a plancache entry.  If the plancache itself sets a field in such an
entry, that doesn't seem problematic from here.

But there's other possibilities if that bothers you; QueryDesc
could hold the field, for example.  Also, I bet we'd want to copy
it into EState for the main initialization recursion.

			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.