Dave Cramer <pg 'at' fastcrypt.com> writes: > Guillaume > > 1G is really not a significant amount of memory these days, Yeah though we have 2G or 4G of RAM in our servers (and not only postgres running on it). > That said 6-10% of available memory should be given to an 8.0 or > older version of postgresql > > Newer versions work better around 25% > > I'm not sure what you mean by mechanically removed from effective_cache I mean that when you allocate more memory to applications, the consequence is less memory the OS will be able to use for disk cache. > effective cache is really a representation of shared buffers plus OS > cache Are you sure the shared buffers should be counted in? As I understand the documentation, they should not (as shared buffers is allocated memory for the OS, not part of "kernel's disk cache"): Sets the planner's assumption about the effective size of the disk cache (that is, the portion of the kernel's disk cache that will be used for PostgreSQL data files). This is measured in disk pages, which are normally 8192 bytes each. The default is 1000. -- Guillaume Cottenceau Create your personal SMS or WAP Service - visit http://mobilefriends.ch/