On Sat, 1 Mar 2008, Shane Ambler wrote:
It may be the way you have worded this but it makes it sound like the cache and the battery backup are as one (or that the cache doesn't work unless you have the battery)...If the raid card has the cache without the battery you would get the performance figures you mentioned, you just wouldn't have the reliability of finishing writes after a power off situation.
Wording is intentional--if you don't have a battery for it, the cache has to be turned off (or set to write-through so it's only being used on reads) in order for the database to be reliable. If you can't finish writes after a power off, you can't cache writes and expect your database to survive for too long.
-- * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
