From: Tom Lane <tgl@sss.pgh.pa.us>
To: Justin Pryzby <pryzby@telsasoft.com>
cc: Robert Creager <robertc@spectralogic.com>,
        Thomas Munro <thomas.munro@gmail.com>,
        pgsql-performance@lists.postgresql.org
Subject: Re: Need help identifying a periodic performance issue.
In-reply-to: <20211117190038.GB17618@telsasoft.com>
References: <3A76761B-3DDD-4A3C-B791-E73107AFC9A2@spectralogic.com>
 <CA+hUKG+iKkdeS9g1=866pypHZwPMQL2ho+oFWLSpRjV=-PvuCg@mail.gmail.com>
 <0C3B1B2B-6571-477D-A89C-6FA7B6259840@spectralogic.com>
 <20211117190038.GB17618@telsasoft.com>
Comments: In-reply-to Justin Pryzby <pryzby@telsasoft.com>
	message dated "Wed, 17 Nov 2021 13:00:38 -0600"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <2736633.1637177330.1@sss.pgh.pa.us>
Date: Wed, 17 Nov 2021 14:28:50 -0500
Message-ID: <2736634.1637177330@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/2736634.1637177330%40sss.pgh.pa.us>
Precedence: bulk

Justin Pryzby <pryzby@telsasoft.com> writes:
> It shows that the process is running FK triggers.

Indeed, and doing a seqscan therein.  Normally I'd suppose that
this reflects a lack of an index, but RI_FKey_check should always
be doing something that matches the referenced table's unique
constraint, so why isn't it using that?

			regards, tom lane