Re: Query Jumbling for CALL and SET utility statements

Julien Rouhaud <rjuju123@gmail.com>

From: Julien Rouhaud <rjuju123@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Paquier <michael@paquier.xyz>, "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, Jeremy Schneider <schnjere@amazon.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Pavel Stehule <pavel.stehule@gmail.com>, Andres Freund <andres@anarazel.de>, "Imseih (AWS), Sami" <simseih@amazon.com>
Date: 2022-10-07T04:18:26Z
Lists: pgsql-hackers
On Thu, Oct 06, 2022 at 11:51:52PM -0400, Tom Lane wrote:
> Michael Paquier <michael@paquier.xyz> writes:
> > While studying a bit more this thread, I've been reminded of the fact
> > that this would treat different flavors of BEGIN/COMMIT commands (mix
> > of upper/lower characters, etc.) as different entries in
> > pg_stat_statements, and it feels inconsistent to me that we'd begin
> > jumbling the 2PC and savepoint commands with their nodes but not do
> > that for the rest of the commands, even if, as mentioned upthread,
> > applications may not mix grammars.
>
> I've been thinking since the beginning of this thread that there
> was no coherent, defensible rationale being offered for jumbling
> some utility statements and not others.

Only a very small subset causes trouble in real life scenario, but I agree that
cherry-picking some utility statements isn't a great approach.

> I wonder if the answer is to jumble them all.  We avoided that
> up to now because it would imply a ton of manual effort and
> future code maintenance ... but now that the backend/nodes/
> infrastructure is largely auto-generated, could we auto-generate
> the jumbling code?

That's a good idea.  Naively, it seems doable as the infrastructure in
gen_node_support.pl already supports everything that should be needed (like
per-member annotation).



Commits

  1. Show values of SET statements as constants in pg_stat_statements

  2. Teach contrib/pg_stat_statements to handle multi-statement commands better.