From: Tom Lane <tgl@sss.pgh.pa.us>
To: exclusion@gmail.com
cc: pgsql-bugs@lists.postgresql.org, Alvaro Herrera <alvherre@2ndquadrant.com>
Subject: Re: BUG #16703: pg-dump fails to process recursive view definition
In-reply-to: <16703-e348f58aab3cf6cc@postgresql.org>
References: <16703-e348f58aab3cf6cc@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
	message dated "Thu, 05 Nov 2020 12:00:01 +0000"
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Date: Thu, 05 Nov 2020 10:00:28 -0500
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PG Bug reporting form <noreply@postgresql.org> writes:
> The following recursive views (borrowed from regress/sql/lock.sql, see
> "detecting infinite recursions in view definitions"):
> CREATE VIEW lock_view2(a) AS SELECT NULL::integer;
> CREATE VIEW lock_view3 AS SELECT * from lock_view2;
> CREATE OR REPLACE VIEW lock_view2 AS SELECT * from lock_view3;
> can be created successfully, but make a subsequent pg_dump fail:
> pg_dump: error: query failed: ERROR:  infinite recursion detected in rules
> for relation "lock_view2"
> pg_dump: error: query was: LOCK TABLE public.lock_view2 IN ACCESS SHARE
> MODE

> The offending commit is 64fc3e03.

Yeah, not surprising.

It seems like the least painful solution might be to teach
LockTableRecurse to detect recursion and just not recurse into
a view it's already locked.  (BTW, I wonder if we shouldn't
have a stack depth check there, too.)

			regards, tom lane