From: Christo Du Preez <christo@mecola.com>
To: pgsql-performance@postgresql.org
Subject: Re: test / live environment, major performance difference
Date: Tue, 12 Jun 2007 15:32:40 +0200
Message-ID: <466EA078.20601@mecola.com> (raw)
Good day,
I have noticed that my server never uses indexing. No matter what I do.
As an example I took a table with about 650 rows, having a parentid
field with an index on parentid.
EXPLAIN ANALYZE
SELECT *
FROM layertype
where parentid = 300;
On my laptop the explain analyze looks like this:
"Index Scan using fki_layertype_parentid on layertype (cost=0.00..8.27
rows=1 width=109)"
" Index Cond: (parentid = 300)"
and on the problem server:
"Seq Scan on layertype (cost=0.00..20.39 rows=655 width=110)"
" Filter: (parentid = 300)"
.........
I have dropped the index, recreated it, vacuumed the table, just about
everything I could think of, And there is just no way I can get the
query planner to use the index.
PostgreSQL 8.2.3 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 4.1.2
20061115 (prerelease) (SUSE Linux)
POSTGIS="1.2.1" GEOS="3.0.0rc4-CAPI-1.3.3" PROJ="Rel. 4.5.0, 22 Oct
2006" USE_STATS
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To: pgsql-performance@postgresql.org
Cc: christo@mecola.com
Subject: Re: test / live environment, major performance difference
In-Reply-To: <466EA078.20601@mecola.com>
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