John, > -work_mem Depends on the number of concurrent queries you expect to run and what size sorts you expect them to do. > -maintenance_work_mem - 50% of the largest table? Actually, in current code I've found that anything over 256mb doesn't actually get used. > -shared_buffers - max value 50000 Actually, I need to update that. On newer faster multi-core machines you may want to allocate up to 1GB of shared buffers. > -effective_cache_size - max 2/3 of available ram, ie 24GB on the > hardware described above Yes. > -shmmax - how large dare I set this value on dedicated postgres servers? Set it to 2GB and you'll be covered. > -checkpoint_segments - this is crucial as one of the server is > transaction heavy Well, it only helps you to raise this if you have a dedicated disk resource for the xlog. Otherwise having more segments doesn't help you much. > -vacuum_cost_delay Try 200ms to start. Also, set wal_buffers to 128. -- Josh Berkus PostgreSQL @ Sun San Francisco
