Re: Database size growing over time and leads to performance impact

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Pierre C wrote:
If you realize you got a bloat problem, for instance due to a misconfigured vacuum, use CLUSTER, which re-generates table AND index data, and besides, having your table clustered on an index of your choice can boost performance quite a lot in some circumstances.

8.2 is so old I don't remember if autovacuum is even included. Please try upgrading to the latest version...

In 8.2, it's included, but not turned on by default. And it can only have a single autovacuum worker, which limits its ability to keep up with more difficult workloads.

As for CLUSTER, the implementation in 8.2 is limited compared to the 8.3 one. If you look at http://www.postgresql.org/docs/8.2/static/sql-cluster.html you'll see a scary paragraph starting with "CLUSTER loses all visibility information of tuples..." that is missing from later versions, because that problem was fixed in 8.3. I try to avoid using CLUSTER on 8.2 or earlier versions unless I can block all clients during the maintenance window it's running in.

--
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@xxxxxxxxxxxxxxx   www.2ndQuadrant.us


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