Re: Anything to be gained from a 'Postgres Filesystem'?
Sean Chittenden <sean@chittenden.org>
From: Sean Chittenden <sean@chittenden.org>
To: Neil Conway <neilc@samurai.com>
Cc: matt@ymogen.net, pgsql-performance@postgresql.org
Date: 2004-10-21T18:40:08Z
Lists: 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