Date: Tue, 27 Sep 2005 13:45:41 +0200
From: Yonatan Ben-Nes <da@canaan.co.il>
Subject: Re: Index use in BETWEEN statement...
In-reply-to: <1896.1127762243@sss.pgh.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Cristian Prieto <cristian@clickdiario.com>,
	'Sean Davis' <sdavis2@mail.nih.gov>, pgsql-general@postgresql.org,
	pgsql-performance@postgresql.org
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Tom Lane wrote:
> "Cristian Prieto" <cristian@clickdiario.com> writes:
> 
>>mydb=# explain analyze select locid from geoip_block where
>>'216.230.158.50'::inet between start_block and end_block;
> 
> 
>>As you see it still using a sequential scan in the table and ignores the
>>index, any other suggestion?
> 
> 
> That two-column index is entirely useless for this query; in fact btree
> indexes of any sort are pretty useless.  You really need some sort of
> multidimensional index type like rtree or gist.  There was discussion
> just a week or three ago of how to optimize searches for intervals
> overlapping a specified point, which is identical to your problem.
> Can't remember if the question was about timestamp intervals or plain
> intervals, but try checking the list archives.
> 
> 			regards, tom lane
> 
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I think that Tom is talking about a discussion which I started entitled 
"Planner create a slow plan without an available index" search for it 
maybe it will help you.
At the end I created an RTREE index and it did solved my problem though 
my data was 2 INT fields and not INET fields as yours so im not sure how 
can you work with that... To solve my problem I created boxes from the 2 
numbers and with them I did overlapping.