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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexandru Coseru <alexandru.coseru@totaltelecom.ro>
Cc: Heikki Linnakangas <heikki@enterprisedb.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Regex performance issue
Date: Sat, 02 Dec 2006 23:05:12 -0500
Message-ID: <12526.1165118712@sss.pgh.pa.us> (raw)
In-Reply-To: <024601c71675$81277560$3cb16956@alex>
References: <030b01c71651$984577c0$8300a8c0@tridecap.com>
	<01ea01c71653$438254e0$3cb16956@alex>
	<4571F856.7090808@enterprisedb.com>
	<022c01c7165f$17f49e80$3cb16956@alex>
	<4571FFA6.6070804@enterprisedb.com>
	<024601c71675$81277560$3cb16956@alex>

"Alexandru Coseru" <alexandru.coseru@totaltelecom.ro> writes:
> Anyway , anybody has a clue why this regex is that CPU intensive ?

The EXPLAIN result you posted offers *no* evidence that the regexp is
CPU intensive.  All you know is that it took 850+ msec to fetch 5200
rows from disk and apply the regexp filter to them.  There's no evidence
here that that was CPU time and not I/O time.

			regards, tom lane

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