Date: Thu, 22 Jul 2021 11:35:56 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: ldh@laurent-hasson.com
Cc: Tom Lane <tgl@sss.pgh.pa.us>, David Rowley <dgrowleyml@gmail.com>,
	Peter Geoghegan <pg@bowt.ie>, pgsql-performance@postgresql.org
Subject: Re: Big performance slowdown from 11.2 to 13.3
Message-ID: <20210722163556.GH19620@telsasoft.com>
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On Thu, Jul 22, 2021 at 04:30:00PM +0000, ldh@laurent-hasson.com wrote:
> Hello Justin,
> 
> > log_executor_stats=on; client_min_messages=debug;
> 
> Would the results then come in EXPLAIN or would I need to pick something up from the logs?

If you're running with psql, and client_min_messages=debug, then it'll show up
as a debug message to the client:

ts=# SET log_executor_stats=on; SET client_min_messages=debug; explain analyze SELECT 1;
SET
SET
LOG:  EXECUTOR STATISTICS
DETAIL:  ! system usage stats:
!       0.000011 s user, 0.000209 s system, 0.000219 s elapsed
!       [0.040608 s user, 0.020304 s system total]
!       7808 kB max resident size
...

It can but doesn't have to use "explain" - that just avoids showing the query
output, since it's not what's interesting here.

-- 
Justin