On Fri, 2008-03-28 at 09:08 +0000, Gregory Stark wrote: > A more invasive form of this patch would be to assign and pin a buffer when > the preread is done. That would men subsequently we would have a pinned buffer > ready to go and not need to go back to the buffer manager a second time. We > would instead just "complete" the i/o by issuing a normal read call.
So if posix_fadvise did nothing or there was a longer than optimal delay, this would be a net loss. You'd need reasonable evidence that the posix_fadvise facility was a win on all platforms and recent release levels before we could agree with that. I think we need a more thorough examination of this area before we commit anything. Maybe you've done this, but I haven't seen the analysis. Can you say more, please? Or at least say what you don't know, so other experts listening can fill in the blanks. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com PostgreSQL UK 2008 Conference: http://www.postgresql.org.uk -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
