CPU Usage

What kinds of operations on a db server cause heavy cpu usage as opposed to IO?
Could sorts or group bys use cpu heavily?
tia
--
MGOn Thu, 21 Feb 2008 09:29:01 -0800, Hurme <michael.geles@.thomson.com>
wrote:
>What kinds of operations on a db server cause heavy cpu usage as opposed to IO?
>Could sorts or group bys use cpu heavily?
>tia
An operation on a lot of rows, where the rows are already in memory
will be CPU intensive. GROUP BY and ORDER BY can fall into that
category.
Roy Harvey
Beacon Falls, CT|||Almost any SQL operation can cause heavy cpu usage as long as the operation
is applied to data already in cache. So in addition to what Roy mentioned,
your simple SELECT or any of the aggregate functions usch as COUNT and SUM
can all drive up cpu usage, if they are run against a small set of data and
are run repeatedly. 'Small' in this case is relative to the SQL instance
buffer pool size.
Linchi
"Hurme" wrote:
> What kinds of operations on a db server cause heavy cpu usage as opposed to IO?
> Could sorts or group bys use cpu heavily?
> tia
> --
> MG|||Optimization is one area. Certain kinds of data conversion and comparisons
can also drive CPU usage. SQL will try and trade CPU and memory usage to
drive down I/O requirements as a way to speed up the overall system.
--
Geoff N. Hiten
Senior SQL Infrastructure Consultant
Microsoft SQL Server MVP
"Hurme" <michael.geles@.thomson.com> wrote in message
news:0394DA83-9905-4B54-8A52-4BC73EDAE326@.microsoft.com...
> What kinds of operations on a db server cause heavy cpu usage as opposed
> to IO?
> Could sorts or group bys use cpu heavily?
> tia
> --
> MG