From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Conlin <dc345@cantab.net>
Cc: pgsql-performance@lists.postgresql.org
Subject: Re: Change in CTE treatment in query plans?
Date: Thu, 17 Oct 2019 11:04:32 +0200
Message-ID: <19441.1571303072@sss.pgh.pa.us> (raw)
In-Reply-To: <560a2cb6-556f-67a7-3676-dba69f2c69e6@cantab.net>
References: <560a2cb6-556f-67a7-3676-dba69f2c69e6@cantab.net>
David Conlin <dc345@cantab.net> writes:
> Does anyone know if there's been a change in the way values for CTEs are
> displayed in query plans?
Offhand I don't recall any such changes, nor does a cursory look
through explain.c find anything promising.
If you're concerned with a multiply-referenced CTE, one possibility
for funny results is that the blame for its execution cost could be
spread across the multiple call sites. The same can happen with
initplans/subplans. But I'm just guessing; you didn't show any
concrete examples so it's hard to be definite.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, dc345@cantab.net, pgsql-performance@lists.postgresql.org
Subject: Re: Change in CTE treatment in query plans?
In-Reply-To: <19441.1571303072@sss.pgh.pa.us>
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