Re: executor relation handling

Amit Langote <langote_amit_f8@lab.ntt.co.jp>

From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Jesper Pedersen <jesper.pedersen@redhat.com>, Amit Langote <amitlangote09@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2018-09-28T08:58:49Z
Lists: pgsql-hackers

Attachments

On 2018/09/28 17:48, David Rowley wrote:
> On 28 September 2018 at 20:28, Amit Langote
> <Langote_Amit_f8@lab.ntt.co.jp> wrote:
>> On 2018/09/28 17:21, David Rowley wrote:
>>> I think we maybe should switch the word "assert" for "verifies". The
>>> Assert is just checking we didn't get a NoLock and I don't think
>>> you're using "assert" meaning the Assert() marco, so likely should be
>>> changed to avoid confusion.
>>
>> Okay, I've revised the text in the attached updated patch.
> 
> Meh, I just noticed that the WARNING text claims "InitPlan" is the
> function name. I think it's best to get rid of that. It's pretty much
> redundant anyway if you do: \set VERBOSITY verbose

Oops, good catch that one.  Removed "InitPlan: " from the message in the
attached.

Thanks,
Amit

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.