Balkrishna Sharma <b_ki(at)hotmail(dot)com> wrote:
> 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.
There's a third option -- PostgreSQL reads and writes will normally
go through the OS cache.
> 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.
> How can I accomplish this ?
You didn't mention your OS. There's usually a way to monitor disk
I/O built in to the OS. I usually start with:
vmstat 1
-Kevin