From: Jim C. Nasby <jnasby@pervasive.com>
To: Marcos <mjs_ops@gmx.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: Simple Question of Performance ILIKE or Lower
Date: Wed, 18 Jan 2006 17:02:30 -0600
Message-ID: <20060118230230.GZ17896@pervasive.com> (raw)
In-Reply-To: <1137575430.966.10.camel@servidor>
References: <1137575430.966.10.camel@servidor>
On Wed, Jan 18, 2006 at 09:10:30AM +0000, Marcos wrote:
> Hi,
>
> I have a simple question about performance using two resources.
>
> What's have the best performance?
>
> lower( col1 ) LIKE lower( 'myquestion%' )
>
> OR
>
> col1 ILIKE 'myquestion%'
If you index lower( col1 ), then the former would likely perform better
(if the optimizer knows it could use the index in that case). Otherwise
I suspect they'd be the same.
Try it and find out.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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To: pgsql-performance@postgresql.org
Cc: jnasby@pervasive.com, mjs_ops@gmx.net
Subject: Re: Simple Question of Performance ILIKE or Lower
In-Reply-To: <20060118230230.GZ17896@pervasive.com>
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