From: Andrus <eetasoft@online.ee>
To: pgsql-performance@postgresql.org
Subject: Why date index is not used
Date: Thu, 8 Jun 2006 21:53:17 +0300
Message-ID: <e69rq9$2a1b$1@news.hub.org> (raw)
Why Postgres 8.1 does not use makse_kuupaev_idx index in the following query
?
How to speed this query up ?
explain analyze select * from makse order by kuupaev desc, kellaaeg desc
limit 100
"Limit (cost=62907.94..62908.19 rows=100 width=876) (actual
time=33699.551..33701.001 rows=100 loops=1)"
" -> Sort (cost=62907.94..63040.49 rows=53022 width=876) (actual
time=33699.534..33700.129 rows=100 loops=1)"
" Sort Key: kuupaev, kellaaeg"
" -> Seq Scan on makse (cost=0.00..2717.22 rows=53022 width=876)
(actual time=0.020..308.502 rows=53028 loops=1)"
"Total runtime: 37857.177 ms"
CREATE TABLE makse(
kuupaev date,
kellaaeg char(6) NOT NULL DEFAULT ''::bpchar,
guid char(36) NOT NULL,
CONSTRAINT makse_pkey PRIMARY KEY (guid) )
CREATE INDEX makse_kuupaev_idx ON makse USING btree (kuupaev);
Andrus.
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To: pgsql-performance@postgresql.org
Cc: eetasoft@online.ee
Subject: Re: Why date index is not used
In-Reply-To: <e69rq9$2a1b$1@news.hub.org>
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