Re: Possible to improve query plan?

It fits a Data Warehousing type application.

Apart from work_mem, my other parameters are pretty close to these numbers. I had the work_mem down a little because a noticed some clients were getting out of memory errors with large queries which involved lots of sorting.

Thanks
Jeremy

-----Original Message-----
From: Ing. Marcos Ortiz Valmaseda [mailto:mlortiz(at)uci(dot)cu]
Sent: Tuesday, 18 January 2011 2:38 a.m.
To: Jeremy Palmer
Cc: pgsql-performance(at)postgresql(dot)org; Andy Colson
Subject: Re: [PERFORM] Possible to improve query plan?

Which is the type of your application? You can see it on the Performance Whackamole Presentation from Josh Berkus on the
PgCon 2009:
- Web application
- Online Transaction Processing (OLTP)
- Data WareHousing (DW)

And based on the type of your application, you can configure the postgresql.conf to gain a better performance of your PostgreSQL server.
PostgreSQL postgresql.conf baseline:
shared_buffers = 25% RAM
work_mem = 512K[W] 2 MB[O] 128 MB[D]
- but no more that RAM/no_connections
maintenance_work_mem = 1/16 RAM
checkpoint_segments = 8 [W], 16-64 [O], [D]
wal_buffer = 1 MB [W], 8 MB [O], [D]
effective_cache_size = 2/3 RAM

Regards

Ing. Marcos Luís Ortíz Valmaseda
Linux User # 418229 && PostgreSQL DBA
Centro de Tecnologías Gestión de Datos (DATEC)
http://postgresql.uci.cu
http://www.postgresql.org
http://it.toolbox.com/blogs/sql-apprentice

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