Subject: "duplicated" wait events

From: "Drouvot, Bertrand" <[email-masked]>
Date: Fri, 4 Aug 2023 17:07:51 +0200

Hi hackers,

while working on the new system catalog pg_wait_event (see [1]) I noticed that some wait
events are currently "duplicated":

postgres=# select wait_event_name,count(*) from pg_wait_event group by wait_event_name having count(*) > 1;
  wait_event_name | count
-----------------+-------
  SyncRep         |     2
  WALWrite        |     2
(2 rows)

Indeed:

SynRep currently appears in "IPC" and "LWLock" (see [2])
WALWrite currently appears in "IO" and "LWLock" (see [2])

I think that can lead to confusion and it would be better to avoid duplicate wait event
name across Wait Class (and so fix those 2 ones above), what do you think?

[1]: https://www.postgresql.org/message-id/0e2ae164-dc89-03c3-cf7f-de86378053ac%40gmail.com
[2]: https://www.postgresql.org/docs/current/monitoring-stats.html

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com