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I am on Fedora 12 (x86_64). Will eventually be on RHE. > Date: Tue, 25 May 2010 12:59:16 -0500 > From: Kevin.Grittner@xxxxxxxxxxxx > To: b_ki@xxxxxxxxxxx; pgsql-admin@xxxxxxxxxxxxxx > Subject: Re: How to find if a SELECT is reading from buffer or disk ? > > Balkrishna Sharma <b_ki@xxxxxxxxxxx> 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 > > -- > Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-admin The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with Hotmail. Get busy. |
