From: Tom Lane <tgl@sss.pgh.pa.us>
To: Daniel Rinehart <danielr@neophi.com>
cc: Laurenz Albe <laurenz.albe@cybertec.at>, pgsql-docs@lists.postgresql.org
Subject: Re: Additional Notes
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Comments: In-reply-to Daniel Rinehart <danielr@neophi.com>
	message dated "Thu, 16 Nov 2023 09:35:15 -0500"
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Date: Thu, 16 Nov 2023 12:05:02 -0500
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Daniel Rinehart <danielr@neophi.com> writes:
> Our callout use of NOTIFY within a TRIGGER may be tangential to the root
> cause. What we wanted to call out is that neither the NOTIFY page or the
> https://www.postgresql.org/docs/16/explicit-locking.html page mention that
> NOTIFY uses an AccessExclusiveLock.

Like Laurenz, I don't see this as being tremendously important.
The lock does not conflict with any user-acquirable lock, and
since it's not a lock on a relation it doesn't wind up getting
propagated to standby servers.  We only use it as a handy way
to serialize commit of transactions that are writing the NOTIFY
queue.  If it were a lesser but still exclusive lock type,
it wouldn't make any difference.

explicit-locking.html is really only about locks on tables.
Maybe that should be clarified somewhere?

			regards, tom lane