Re: RAID arrays and performance

On Tue, 29 Jan 2008, Gregory Stark wrote:
>> So, this is FYI, and also an added encouragement to implement fadvise
>> prefetching in some form or another. How's that going by the way?
>
> I have a patch which implements it for the low hanging fruit of bitmap index
> scans. it does it using an extra trip through the buffer manager which is the
> least invasive approach but not necessarily the best.

Gregory - what's the status of that patch at the moment? Will it be making
it into a new version of Postgres, or are we waiting for it to be
implemented fully?

It's just that our system is doing a lot of bitmap index scans at the
moment, and it'd help to be able to spread them across the 16 discs in
the RAID array. It's the bottleneck in our system at the moment.

Matthew

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