From: Cristian Prieto <cristian@clickdiario.com>
To: pgsql-general@postgresql.org
Subject: Index use in BETWEEN statement...
Date: Mon, 26 Sep 2005 09:26:43 -0600
Message-ID: <20050926153244.C336210149@mail.clickdiario.com> (raw)
In-Reply-To: <20050923220857.3A0841001E@mail.clickdiario.com>
Hello pals, I have the following table in Postgresql 8.0.1
Mydb# \d geoip_block
Table "public.geoip_block"
Column | Type | Modifiers
-------------+--------+-----------
locid | bigint |
start_block | inet |
end_block | inet |
mydb# explain analyze select locid from geoip_block where
'216.230.158.50'::inet between start_block and end_block;
QUERY PLAN
----------------------------------------------------------------------------
-------------------------------------------
Seq Scan on geoip_block (cost=0.00..142772.86 rows=709688 width=8) (actual
time=14045.384..14706.927 rows=1 loops=1)
Filter: (('216.230.158.50'::inet >= start_block) AND
('216.230.158.50'::inet <= end_block))
Total runtime: 14707.038 ms
Ok, now I decided to create a index to "speed" a little the query
Mydb# create index idx_ipblocks on geoip_block(start_block, end_block);
CREATE INDEX
clickad=# explain analyze select locid from geoip_block where
'216.230.158.50'::inet between start_block and end_block;
QUERY PLAN
----------------------------------------------------------------------------
------------------------------------------
Seq Scan on geoip_block (cost=0.00..78033.96 rows=230141 width=8) (actual
time=12107.919..12610.199 rows=1 loops=1)
Filter: (('216.230.158.50'::inet >= start_block) AND
('216.230.158.50'::inet <= end_block))
Total runtime: 12610.329 ms
(3 rows)
I guess the planner is doing a sequential scan in the table, why not use the
compound index? Do you have any idea in how to speed up this query?
Thanks a lot!
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To: pgsql-performance@postgresql.org
Cc: cristian@clickdiario.com, pgsql-general@postgresql.org
Subject: Re: Index use in BETWEEN statement...
In-Reply-To: <20050926153244.C336210149@mail.clickdiario.com>
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