From: Pierre C <lists@peufeu.com>
To: pgsql-performance@postgresql.org, "Kabu Taah" <kabuutah@hot.ee>
Subject: Re: Degrading PostgreSQL 8.4 write performance
Date: Mon, 20 Jun 2011 01:05:32 +0200
Message-ID: <op.vxcifizfeorkce@apollo13> (raw)
In-Reply-To: <20110617124857.1A82B432167@Bounce1.estpak.ee>
References: <20110617124857.1A82B432167@Bounce1.estpak.ee>
> Load testing of postgresql 8.4 for OLTP application
> suitability showed that throughput of the
> database significantly degraded over time from thousands of write
> transactions per second to almost zero.
A typical postgres benchmarking gotcha is :
- you start with empty tables
- the benchmark fills them
- query plans which were prepared based on stats of empty (or very small)
tables become totally obsolete when the table sizes grow
- therefore everything becomes very slow as the tables grow
So you should disconnect/reconnect or issue a DISCARD ALL periodically on
each connection, and of course periodically do some VACUUM ANALYZE (or
have autovacuum do that for you).
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To: pgsql-performance@postgresql.org
Cc: lists@peufeu.com, kabuutah@hot.ee
Subject: Re: Degrading PostgreSQL 8.4 write performance
In-Reply-To: <op.vxcifizfeorkce@apollo13>
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