Re: bgwriter update question

"Mark Steben" <msteben@autorevenue.com> writes:
> I'm running on 7.4.5 (pre bgwriter) and moving to 8.2 in 3 weeks. I turn
> fsync off on my testing server. When I update a table I expect the file in
> the base directory to remain the same size until the next syncpoint when it
> would then update. But it increases immediately. I thought updates remain in
> memory until syncpoint in pre-8.0. Am I missing somethng?

The updates don't go to disk immediately (they didn't in 7.4 either).
But we always allocate disk space immediately when needed, to make sure
it's available.  Otherwise we could face the embarrassing situation of
having noplace to put rows inserted by an already-reported-committed
transaction.

            regards, tom lane