> > > Apparently this formula is no longer relevant on the FreeBSD systems as > > > it can cache up to almost all the available RAM. With 4GB of RAM, one > > > could specify most of the RAM as being available for caching, assuming > > > that nothing but PostgreSQL runs on the server -- certainly 1/2 the RAM > > > would be a reasonable value to tell the planner. > > > > > > (This was verified by using dd: > > > dd if=/dev/zero of=/usr/local/pgsql/iotest bs=128k count=16384 to create > > > a 2G file then > > > dd if=/usr/local/pgsql/iotest of=/dev/null > > > > > > If you run systat -vmstat 2 you will see 0% diskaccess during the read > > > of the 2G file indicating that it has, in fact, been cached) > > > > Thank you for your reply. Does this apply to FreeBSD 5.4 or 6.0 on > > amd64 (or both)? > > > > Not sure about 6.0 (but I don't know why it would change) but definitely > on 5.4 amd64 (and I would imagine i386 as well).
Works on FreeBSD 6.0 RC1 as well. Tried using count=4096 on a 1 GB ram box. Same behaviour as you describe above. regards Claus ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly