From: Tom Lane <tgl@sss.pgh.pa.us>
To: Yves Vindevogel <yves.vindevogel@implements.be>
Cc: pgsql-performance@postgresql.org
Subject: Re: Updates on large tables are extremely slow
Date: Mon, 13 Jun 2005 10:32:16 -0400
Message-ID: <19628.1118673136@sss.pgh.pa.us> (raw)
In-Reply-To: <65760c67987848d35eafecdcccd8742c@implements.be>
References: <579bc853ef3957c736c2773f13c444f7@implements.be>
<42ACF2DD.8090409@paradise.net.nz>
<e61732b6bc4e763c947b526c2c099fbc@implements.be>
<42AD49BF.7050706@paradise.net.nz>
<65760c67987848d35eafecdcccd8742c@implements.be>
Yves Vindevogel <yves.vindevogel@implements.be> writes:
> rvponp=3D# vacuum verbose tblPrintjobs ;
> INFO: vacuuming "public.tblprintjobs"
> [ twenty-one different indexes on one table ]
Well, there's your problem. You think updating all those indexes is
free? It's *expensive*. Heed the manual's advice: avoid creating
indexes you are not certain you need for identifiable commonly-used
queries.
(The reason delete is fast is it doesn't have to touch the indexes ...
the necessary work is left to be done by VACUUM.)
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, yves.vindevogel@implements.be
Subject: Re: Updates on large tables are extremely slow
In-Reply-To: <19628.1118673136@sss.pgh.pa.us>
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