Re: pg_stat_statements and "IN" conditions

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: 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>
Date: 2022-03-14T15:38:23Z
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.

Dmitry Dolgov <9erthalion6@gmail.com> writes:
> On Mon, Mar 14, 2022 at 11:23:17AM -0400, Tom Lane wrote:
>> I do find it odd that the proposed patch doesn't cause the *entire*
>> list to be skipped over.  That seems like extra complexity and confusion
>> to no benefit.

> That's a bit surprising for me, I haven't even thought that folks could
> think this is an odd behaviour. As I've mentioned above, the original
> idea was to give some clues about what was inside the collapsed array,
> but if everyone finds it unnecessary I can of course change it.

But if what we're doing is skipping over an all-Consts list, then the
individual Consts would be elided from the pg_stat_statements entry
anyway, no?  All that would remain is information about how many such
Consts there were, which is exactly the information you want to drop.

			regards, tom lane