Horton

Re: pg_stat_statements and "IN" conditions

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Marcos Pegoraro <marcos@f10.com.br>, vignesh C <vignesh21@gmail.com>, Sergei Kornilov <sk@zsrv.org>, Robert Haas <robertmhaas@gmail.com>, Zhihong Yu <zyu@yugabyte.com>, David Steele <david@pgmasters.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Greg Stark <stark@mit.edu>, Pavel Trukhanov <pavel.trukhanov@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2023-02-05T01:30:25Z
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 Sat, Feb 04, 2023 at 06:08:41PM +0100, Dmitry Dolgov wrote:
> Here is the rebased version. To adapt to the latest changes, I've marked
> ArrayExpr with custom_query_jumble to implement this functionality, but
> tried to make the actual merge logic relatively independent. Otherwise,
> everything is the same.

I was quickly looking at this patch, so these are rough impressions.

+   bool        merged;         /* whether or not the location was marked as
+                                  not contributing to jumble */

This part of the patch is a bit disturbing..  We have node attributes
to track if portions of a node should be ignored or have a location
marked, still this "merged" flag is used as an extension to track if a
location should be done or not.  Is that a concept that had better be
controlled via a new node attribute?

+--
+-- Consts merging
+--
+CREATE TABLE test_merge (id int, data int);
+-- IN queries
+-- No merging

Would it be better to split this set of tests into a new file?  FWIW,
I have a patch in baking process that refactors a bit the whole,
before being able to extend it so as we have more coverage for
normalized utility queries, as of now the query strings stored by
pg_stat_statements don't reflect that even if the jumbling computation
marks the location of the Const nodes included in utility statements
(partition bounds, queries of COPY, etc.).  I should be able to send
that tomorrow, and my guess that you could take advantage of that
even for this thread.
--
Michael