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To: PostgreSQL Server <postgres@rsd.it>
Cc: pgsql-sql@postgresql.org
Subject: Re: DATE TIME INDEX ? 
In-reply-to: 
 <Pine.LNX.4.44.0211161743400.8254-100000@sunrise2.radiostudiodelta.it>
References: 
 <Pine.LNX.4.44.0211161743400.8254-100000@sunrise2.radiostudiodelta.it>
Comments: In-reply-to PostgreSQL Server <postgres@rsd.it>
	message dated "Sat, 16 Nov 2002 18:01:02 +0100"
Date: Sat, 16 Nov 2002 13:42:08 -0500
Message-ID: <19219.1037472128@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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PostgreSQL Server <postgres@rsd.it> writes:
> I found that the only way to force postgres to use index is:

> explain select id,datarx::date from docs where datarx between '2002-11-13' and '2002-11-14' ;

> Index Scan using idx_documenti_datarx on documenti  (cost=0.00..7.86 rows=2 width=12)

Given the small cost estimates, you either are testing on a toy table,
or you have not run ANALYZE since loading up the table.

			regards, tom lane