[OSM-dev] Postgres 8.4/PostGIS 1.4 performance

Jochen Topf jochen at remote.org
Sat Sep 19 18:42:53 BST 2009

On Sat, Sep 19, 2009 at 07:12:14PM +0200, Martijn van Oosterhout wrote:
> On Wed, Sep 16, 2009 at 9:39 PM, Martin Lesser <ml-osm-dev at bettercom.de> wrote:
> >> Can anybody confirm this measurement, or even suggest what the reason
> >> might be?
> >
> > Another pointer: How many VACUUMs does osm2pgsql trigger during import
> > and filling the own tables?
> None, AFAICS from the source. That's what autovacuum is for. It does
> analyse each table.
> (I beleive it used to vacuum, but I don't immediately see it in the
> current source).

I always disabled autovacuum for this kind of database. It tends to always
come at the wrong time. Its better to do the vacuum once after an import
run and never in between. Autovacuum is nice for a database where many
different programs change data all the time. For a OSM Mapnik database where
there is exactly one program changing data, it should do the vacuum itself.

Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298

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