On Tue, May 25, 2010 at 1:48 PM, Balkrishna Sharma <b...@hotmail.com> wrote:
> Hi, > > I am increasing the shared_buffer size in postgresql.conf and want to > measure its effect on READ. In essence I want to know if the SELECT queries > I am firing repeatedly is reading from the buffer or going directly to the > disk. > > I am expecting the first SELECT to go to disk and the subsequent call of > the same SELECT to read from buffer . > > Right now I am just looking at execution time of the SELECTs and trying to > conclude. But there should be a direct way to see where the SELECT reads > from. > You can also use pg_stat_database view. you can compute cache reads percentage of the total number of reads (cache and physical) between the two snapshots using pg_stat_database.blks_hit and pg_stat_database.blks_read. Chirag Dave 416-673-4102 Database Administrator, Afilias Canada Corp. cd...@ca.afilias.info > How can I accomplish this ? > > Thanks > Bala > > ------------------------------ > The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with > Hotmail. Get > busy.<http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5> >
