| From: | "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com> |
|---|---|
| To: | Sriram Dandapani <sdandapani(at)counterpane(dot)com> |
| Cc: | "Pgsql-Performance (E-mail)" <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: planner not using index for like operator |
| Date: | 2006-04-25 18:24:45 |
| Message-ID: | 20060425182444.GK97354@pervasive.com |
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| Lists: | pgsql-performance |
On Tue, Apr 25, 2006 at 10:08:02AM -0700, Sriram Dandapani wrote:
Here's the key:
> " Filter: ((col1)::text ~~ '172.%'::text)"
In order to do a like comparison, it has to convert col1 (which I'm
guessing is of type 'inet') to text, so there's no way it can use an
index on col1 (maybe a function index, but that's a different story).
Is there some reason you're not doing
WHERE col1 <<= '172/8'::inet
?
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)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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