From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Michael Fuhr <mike@fuhr.org>
Cc: Bruno Wolff III <bruno@wolff.to>
Cc: Martin Lesser <ml-pgsql@bettercom.de>
Cc: Stephan Szabo <sszabo@megazone.bigpanda.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Effects of cascading references in foreign keys
Date: Wed, 14 Jun 2006 18:12:48 -0400 (EDT)
Message-ID: <200606142212.k5EMCm204045@candle.pha.pa.us> (raw)
In-Reply-To: <12097.1130610925@sss.pgh.pa.us>
Would someone please find the answer to Tom's last question?
---------------------------------------------------------------------------
Tom Lane wrote:
> I wrote:
> > Looking at this, I wonder if there isn't a bug or at least an
> > inefficiency in 8.1. The KeysEqual short circuit tests are still there
> > in ri_triggers.c; aren't they now redundant with the test in triggers.c?
> > And don't they need to account for the special case mentioned in the
> > comment in triggers.c, that the RI check must still be done if we are
> > looking at a row updated by the same transaction that created it?
>
> OK, I take back the possible-bug comment: the special case only applies
> to the FK-side triggers, which is to say RI_FKey_check, and that routine
> doesn't attempt to skip the check on equal old/new keys. I'm still
> wondering though if the KeysEqual tests in the other RI triggers aren't
> now a waste of cycles.
>
> regards, tom lane
>
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--
Bruce Momjian http://candle.pha.pa.us
EnterpriseDB http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
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To: pgsql-performance@postgresql.org
Cc: pgman@candle.pha.pa.us, tgl@sss.pgh.pa.us, mike@fuhr.org, bruno@wolff.to, ml-pgsql@bettercom.de, sszabo@megazone.bigpanda.com
Subject: Re: Effects of cascading references in foreign keys
In-Reply-To: <200606142212.k5EMCm204045@candle.pha.pa.us>
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