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From: "Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
To: "Elielson Fontanezi" <ElielsonF@prodam.sp.gov.br>,
	"'Daryl Herzmann'" <akrherz@iastate.edu>
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	"pgsql-general" <pgsql-general@postgresql.org>
References: <A799F7647794D311924A005004ACEA97080DDE89@cprodamibs249.prodam>
Subject: Re: [SQL] Queries not using Index
Date: Wed, 24 Jul 2002 23:48:08 +0800
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> This SELECT causes a sequention scan 'cause your index
> is not HASH type, but likely a BTREE one.
> BTREE index is to interval searches (station = 'SAMI4%')
> not precise searchs. (station = 'SAMI4').

In Postgres, the hash index is slow and inefficient (it's a bit better
in7.3), and I believe btree is generally recommended over hash even for '='
instances.

Chris