Re: 8.4 open item: copy performance regression?

"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Regarding the fact that even with the xlog files pre-populated, the
> smaller set of xlog files is faster: I'm only guessing, but I suspect
> the battery backed RAID controller is what's defeating conventional
> wisdom here.  By writing to the same, relatively small, set of xlog
> files repeatedly, some of the actual disk writes probably evaporate in
> the BBU cache.

Yeah, sounds plausible.  How big is your BBU cache?
        regards, tom lane