Horton

Re: executor relation handling

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: David Rowley <david.rowley@2ndquadrant.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Jesper Pedersen <jesper.pedersen@redhat.com>, Amit Langote <amitlangote09@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-02-09T23:31:49Z
Lists: pgsql-hackers 
Julien Rouhaud <rjuju123@gmail.com> writes:
> I just hit one of the asserts (in relation_open()) added in
> b04aeb0a053.  Here's a simple reproducer:

Yeah, I think this is the same issue being discussed in

https://www.postgresql.org/message-id/flat/19465.1541636036%40sss.pgh.pa.us

I imagine the patch David recently posted in that thread will fix this,
but can you check, and/or review the patch?

			regards, tom lane

Commits

  1. Avoid O(N^2) cost in ExecFindRowMark().

  2. Remove some unnecessary fields from Plan trees.

  3. Restore sane locking behavior during parallel query.

  4. Remove more redundant relation locking during executor startup.

  5. In the executor, use an array of pointers to access the rangetable.

  6. Centralize executor's opening/closing of Relations for rangetable entries.

  7. Change executor to just Assert that table locks were already obtained.

  8. Change rewriter/planner/executor/plancache to depend on RTE rellockmode.

  9. Add assertions that we hold some relevant lock during relation open.

  10. Create an RTE field to record the query's lock mode for each relation.