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: David Rowley <david.rowley@2ndquadrant.com>
Cc: 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: 2018-10-01T02:49:18Z
Lists: pgsql-hackers 
David Rowley <david.rowley@2ndquadrant.com> writes:
> On 1 October 2018 at 06:18, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> + for (slockmode = lockmode + 1;
>> +      slockmode <= AccessExclusiveLock;
>> +      slockmode++)

> So would it not be better to add the following to lockdefs.h?
> #define MaxLockLevel 8
> then use that to terminate the loop.

Good idea, will do.

			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.