Re: Flush Shared Buffer Cache - Mailing list pgsql-admin

From Suvankar Roy
Subject Re: Flush Shared Buffer Cache
Date
Msg-id OFF46F752A.C15FB624-ON652575F5.001C8D93-652575F5.001D484C@tcs.com
Whole thread Raw
In response to Re: Flush Shared Buffer Cache  (Chander Ganesan <chander@otg-nc.com>)
Responses Re: Flush Shared Buffer Cache
List pgsql-admin

Hi Chander,

Actually I am trying to figure out how much execution time any query is taking is taking when executed for the first time.

Because once a query is executed for the first time, the query plan, data buffer is cached so subsequently time taken is much lower.

For this, I want to have the Shared buffer cache flushed to note the initial execution time.

Is my understanding correct here ?

Regards,

Suvankar Roy



Chander Ganesan <chander@otg-nc.com>

07/15/2009 08:48 PM

To
Suvankar Roy <suvankar.roy@tcs.com>
cc
pgsql-admin@postgresql.org
Subject
Re: [ADMIN] Flush Shared Buffer Cache





Suvankar Roy wrote:
>
> Hi,
>
> Can anyone help me out with how to flush out Shared Buffer Cache in
> Postgres.
>
> One way would be to restart the database, but I would like to avoid that.
AFAIK, that's the only way.

Is there a reason that you need to dump the shared buffers?  Perhaps if
we knew what you were trying to accomplish we could provide you with a
suitable solution that doesn't require a restart...

--
Chander Ganesan
Open Technology Group, Inc.
One Copley Parkway, Suite 210
Morrisville, NC  27560
919-463-0999/877-258-8987
http://www.otg-nc.com
Expert PostgreSQL, PostGIS, and other Open Source training delivered worldwide.


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