RE: question about cpu usage
- From: DENNIS WILLIAMS <DWILLIAMS@xxxxxxxxxxxxx>
- To: ryan_gaffuri@xxxxxxxxxxx, oracle-l@xxxxxxxxxxxxx
- Date: Fri, 22 Oct 2004 16:02:11 -0500
Ryan
Perhaps you can tolerate a mini-O.S. lesson.
A process can be in several states -- running (only one process/CPU),
waiting (for I/O, user response, etc.), or ready-to-run (or run queue). The
O.S. lets each process have the CPU (running) for a short interval of time,
or until it must wait for something like I/O. Once a process has its I/O
satisfied, it is put on the ready-to-run queue until the O.S. decides to put
it back on the CPU.
Basically there is a queue of processes waiting for the CPU. If the
system is nearly idle, that queue will be very short. When the process is
back from the I/O, it is quickly put back on the CPU. If the system is
heavily loaded, then the queue will get very long. If you are interested and
on Unix, check out the uptime command, which will show you the length of the
run queue on your server.
Many people find the run queue a better indicator of how heavily loaded
an OLTP server is.
Dennis Williams
DBA
Lifetouch, Inc.
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of ryan_gaffuri@xxxxxxxxxxx
Sent: Friday, October 22, 2004 2:56 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: question about cpu usage
I'm not a hardware guy or sys admin person so forgive me if this is a stupid
question. Leaving out all other variables(such as IO), should I expect
performance to be the same in a databse if the server it is riding at is at
90% cpu usages as opposed to 10%? since there would still be spare cycles?
Or is there a declining returns as you get closing to the maximum available
cpu usage?
--
//www.freelists.org/webpage/oracle-l
--
//www.freelists.org/webpage/oracle-l
Other related posts:
