Horton

Re: Can we get rid of repeated queries from pg_dump?

hubert depesz lubaczewski <depesz@depesz.com>

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From: hubert depesz lubaczewski <depesz@depesz.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>, pgsql-general <pgsql-general@lists.postgresql.org>
Date: 2021-08-28T06:38:24Z
Lists: pgsql-hackers, pgsql-general 
On Fri, Aug 27, 2021 at 05:23:23PM -0400, Tom Lane wrote:
> I experimented with the attached, very quick-n-dirty patch to collect
> format_type results during the initial scan of pg_type, instead.  On the
> regression database in HEAD, it reduces the number of queries pg_dump
> issues from 3260 to 2905; but I'm having a hard time detecting any net
> performance change.
> (This is not meant for commit as-is; notably, I didn't bother to fix
> getTypes' code paths for pre-9.6 servers.  It should be fine for
> performance testing though.)

Hi,
thanks a lot for this. Will test and report back, most likely on Monday,
though.

Best regards,

depesz

Commits

  1. In pg_dump, avoid doing per-table queries for RLS policies.

  2. Cache the results of format_type() queries in pg_dump.