[EMAIL PROTECTED] (Stuart Bishop) writes: > I'm putting together a road map on how our systems can scale as our > load increases. As part of this, I need to look into setting up some > fast read only mirrors of our database. We should have more than > enough RAM to fit everything into memory. I would like to find out > if I could expect better performance by mounting the database from a > RAM disk, or if I would be better off keeping that RAM free and > increasing the effective_cache_size appropriately.
If you were willing to take on a not-inconsiderable risk, I'd think that storing WAL files on a RAMDISK would be likely to be the fastest improvement imaginable. If I could get and deploy some SSD (Solid State Disk) devices that would make this sort of thing *actually safe,* I'd expect that to be a pretty fabulous improvement, at least for write-heavy database activity. > I'd also be interested in knowing if this is dependant on whether I > am running 7.4, 8.0 or 8.1. Behaviour of all three could be somewhat different, as management of the shared cache has been in flux... -- (format nil "[EMAIL PROTECTED]" "cbbrowne" "acm.org") http://www.ntlug.org/~cbbrowne/sap.html Rules of the Evil Overlord #78. "I will not tell my Legions of Terror "And he must be taken alive!" The command will be: ``And try to take him alive if it is reasonably practical.''" <http://www.eviloverlord.com/> ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq