From: Scott Marlowe <smarlowe@g2switchworks.com>
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 19:31:37 -0600
Message-ID: <1165109498.25316.15.camel@localhost.localdomain> (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>
On Sun, 2006-12-03 at 02:53 +0200, Alexandru Coseru wrote:
> Hello..
>
> Thanks for the tip , i think i have got the ideea..
>
> I'm too tired too , and i will try it tommorow.
>
>
> Anyway , anybody has a clue why this regex is that CPU intensive ? I did
> not saw the light on my drives blinking , and also vmstat doesn't yeld any
> blocks in or out...
> And how can it be optimized ?
I think it's just that you're running the regex across 5400 or so
elements. at 850 or so milliseconds, that comes out to 150uS for each
comparison. I'd say it's just the number of comparisons that have to be
made that's killing you here.
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To: pgsql-performance@postgresql.org
Cc: smarlowe@g2switchworks.com, alexandru.coseru@totaltelecom.ro, heikki@enterprisedb.com
Subject: Re: Regex performance issue
In-Reply-To: <1165109498.25316.15.camel@localhost.localdomain>
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