On Sun, 7 Jul 2002 13:06:00 +0900 (JST) Curt Sampson <[EMAIL PROTECTED]> wrote:
> > On this particular system, though, it's doing > > nothing except PG. 384 MB of RAM, I can give PG 160 of it, which > > leaves me with some 170 MB of idle RAM. > > No, that's not idle RAM; that's buffer cache. (FreeBSD, like most > modern Unix operating systems, will use any spare physical memory > to cache blocks read from the disk.) If you allocate 160/170, you > now have pretty much maximized your chances that postgres and the > operating system will be buffering the same data, and made your > memory as minimally effective as possible. Is there not a method of reading a disk block and instructing the OS not to buffer it, or am I hallucinating? (My main RDBMS experience experience is on Solaris, and I could swear that major RDBMSs on that OS will ask the OS not to buffer disk I/O on behalf of the database) -- Tim Ellis DBA, Gamet ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
