Horton

Re: pg_stat_statements and "IN" conditions

vignesh C <vignesh21@gmail.com>

View thread
From: vignesh C <vignesh21@gmail.com>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Nathan Bossart <nathandbossart@gmail.com>, "Gregory Stark (as CFM)" <stark.cfm@gmail.com>, David Geier <geidav.pg@gmail.com>, Sergei Kornilov <sk@zsrv.org>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Marcos Pegoraro <marcos@f10.com.br>, Robert Haas <robertmhaas@gmail.com>, Zhihong Yu <zyu@yugabyte.com>, David Steele <david@pgmasters.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Pavel Trukhanov <pavel.trukhanov@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2024-01-06T15:34:54Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Introduce squashing of constant lists in query jumbling

  2. Make documentation builds reproducible

  3. Include values of A_Const nodes in query jumbling

  4. Teach planner about more monotonic window functions

  5. Split up guc.c for better build speed and ease of maintenance.

On Tue, 31 Oct 2023 at 14:36, Dmitry Dolgov <9erthalion6@gmail.com> wrote:
>
> > On Fri, Oct 27, 2023 at 05:02:44PM +0200, Dmitry Dolgov wrote:
> > > On Thu, Oct 26, 2023 at 09:08:42AM +0900, Michael Paquier wrote:
> > >  typedef struct ArrayExpr
> > >  {
> > > +   pg_node_attr(custom_query_jumble)
> > > +
> > >
> > > Hmm.  I am not sure that this is the best approach
> > > implementation-wise.  Wouldn't it be better to invent a new
> > > pg_node_attr (these can include parameters as well!), say
> > > query_jumble_merge or query_jumble_agg_location that aggregates all
> > > the parameters of a list to be considered as a single element.  To put
> > > it short, we could also apply the same property to other parts of a
> > > parsed tree, and not only an ArrayExpr's list.
> >
> > Sounds like an interesting idea, something like:
> >
> >     typedef struct ArrayExpr
> >     {
> >         ...
> >         List     *elements pg_node_attr(query_jumble_merge);
> >
> > to replace simple JUMBLE_NODE(elements) with more elaborated logic.
> >
> > >  /* GUC parameters */
> > >  extern PGDLLIMPORT int compute_query_id;
> > > -
> > > +extern PGDLLIMPORT bool query_id_const_merge;
> > >
> > > Not much a fan of this addition as well for an in-core GUC.  I would
> > > suggest pushing the GUC layer to pg_stat_statements, maintaining the
> > > computation method to use as a field of JumbleState as I suspect that
> > > this is something we should not enforce system-wide, but at
> > > extension-level instead.
> >
> > I also do not particularly like an extra GUC here, but as far as I can
> > tell to make it pg_stat_statements GUC only it has to be something
> > similar to EnableQueryId (e.g. EnableQueryConstMerging), that will be
> > called from pgss. Does this sound better?
>
> For clarity, here is what I had in mind for those two points.

CFBot shows documentation build has failed at [1] with:
[07:44:55.531] time make -s -j${BUILD_JOBS} -C doc
[07:44:57.987] postgres.sgml:572: element xref: validity error : IDREF
attribute linkend references an unknown ID
"guc-query-id-const-merge-threshold"
[07:44:58.179] make[2]: *** [Makefile:70: postgres-full.xml] Error 4
[07:44:58.179] make[2]: *** Deleting file 'postgres-full.xml'
[07:44:58.181] make[1]: *** [Makefile:8: all] Error 2
[07:44:58.182] make: *** [Makefile:16: all] Error 2

[1] - https://cirrus-ci.com/task/6688578378399744

Regards,
Vignesh