Horton

Re: Gather performance analysis

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-10-14T20:18:29Z
Lists: pgsql-hackers 
On Tue, Oct 12, 2021 at 10:14 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> Thanks, yeah now it looks in line with other results.

Since it seems there are no remaining concerns here, and we have
benchmarking results showing that the patch helps, I have committed
the patch.

I wonder whether the new code in shm_mq_send_bytes() should guard
against calling shm_mq_inc_bytes_written() with a second argument of
0, or alternatively whether shm_mq_inc_bytes_written() should have an
internal defense against that. It might save some writes to shared
memory, but it would also add a branch, which isn't free, either.

I also think that, as a followup action item, we need to reassess
parallel_tuple_cost.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

Commits

  1. shm_mq: Update mq_bytes_written less often.