Re: Anything to be gained from a 'Postgres Filesystem'? - Mailing list pgsql-performance

From Sean Chittenden
Subject Re: Anything to be gained from a 'Postgres Filesystem'?
Date
Msg-id A238AA78-2390-11D9-9171-000A95C705DC@chittenden.org
Whole thread Raw
In response to Re: Anything to be gained from a 'Postgres Filesystem'?  (Neil Conway <neilc@samurai.com>)
List pgsql-performance
> As someone else noted, this doesn't belong in the filesystem (rather
> the kernel's block I/O layer/buffer cache). But I agree, an API by
> which we can tell the kernel what kind of I/O behavior to expect would
> be good.
[snip]
> The closest API to what you're describing that I'm aware of is
> posix_fadvise(). While that is technically-speaking a POSIX standard,
> it is not widely implemented (I know Linux 2.6 implements it; based on
> some quick googling, it looks like AIX does too).

Don't forget about the existence/usefulness/widely implemented
madvise(2)/posix_madvise(2) call, which can give the OS the following
hints: MADV_NORMAL, MADV_SEQUENTIAL, MADV_RANDOM, MADV_WILLNEED,
MADV_DONTNEED, and MADV_FREE.  :)  -sc

--
Sean Chittenden


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