> > When performing complex queries, with thousands of records and > > geometries I am noticing that the postmaster process never exceeds 1% > > of my system's memory (2Gb). I have tried setting the shared_buffers > > parameter to values > 2000 ... but this only leads to an error when the > > postgres server is restarted: cannot allocate this much mem, check the > > SHMMAX kernel parameter.
It sounds to me like you need to recompile Postgres with new values for SHMAX (and maybe other parameters too - I would ask on the Postgres General list). Building postgres is trivial, and if it is for a production machine it might be quite worthwhile -- there might be options for stripping debug symbols etc . -W > > > > Perhaps some answers on are this page: > > http://www.redhat.com/docs/manuals/database/RHDB-2.1-Manual/admin_user/ > > kernel-resources.html > > > > or in the minds of people on the list. The machine in question is > > mostly used for such queries and I would like postgis to be able to > > better utilize the resources available. > > > > Cheers, > > > > Dylan > > > Hi Dylan, > > Indeed, everything you need to know should be on that page - here is the > most recent version: > http://www.postgresql.org/docs/8.2/interactive/kernel-resources.html. > Experiment with different settings, but most people tend to recommend > about 25% of your available RAM (~60,000 buffers for 2Gb) for a > dedicated database server. > > > HTH, > > Mark. > > -- > ILande - Open Source Consultancy > http://www.ilande.co.uk > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
