On Mon, Apr 16, 2012 at 06:24:57AM +0200, Boszormenyi Zoltan wrote: > Yes, just like when the readahead window set to 256, FETCH 1024 > will iterate through 4 windows or FETCH 64 iterates through the > same window 4 times. This is the idea behind the "readahead window".
Really? It's definitely not the idea behind FETCH 1024. Using the same window 4 times for FETCH 64 is the idea though, I agree. > How about allowing the readahead window to be resized for the > non-decorated case if the runtime encounters FETCH N and N is > greater than the previous window? To be resized by what? IMO a FETCH N should always be a FETCH N, no matter what, i.e. if the readahead window is larger, use it, but even if it's smaller we should still fetch N at the same time. Michael -- Michael Meskes Michael at Fam-Meskes dot De, Michael at Meskes dot (De|Com|Net|Org) Michael at BorussiaFan dot De, Meskes at (Debian|Postgresql) dot Org Jabber: michael.meskes at googlemail dot com VfL Borussia! Força Barça! Go SF 49ers! Use Debian GNU/Linux, PostgreSQL -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
