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Re: Database Performance Problem between 3:00PM and 4:00PM

From: <>
Date: Mon, 22 Oct 2007 11:04:13 -0700
Message-ID: <>

On Oct 22, 1:46 pm, joel garry <> wrote:
> On Oct 22, 8:12 am, gazzag <> wrote:
> > On 22 Oct, 15:56, wrote:
> > > I am Windows 2000 server using Oracle We have strange problem
> > > where by database becomes extremely slow between 3:00PM and 4:00PM.
> > > Same queries which take 15 seconds before 3:00PM (e.g., 2:55PM) take
> > > 3-4 minutes at 3:00PM and after that. Poblem starts right at 3:00PM
> > > every day. No of users etc are same. We have asked users not to use
> > > the system during that period for isolating performance problem,
> > > without any success.
> > > When one looks at CPU Usage, Memory Usage and Disk Usage nothing
> > > changes between 2:55PM and (3:00PM-4:00PM). I kooked at task mgr, no
> > > new processes. I have looked at Windows scheduler, Oracle dbms_job.
> > > Nothing is running between 3:00PM-4:00PM. I have no clue why system
> > > becomes so slow in that period. I was hoping that some job starts at
> > > that time, but cannot find any. Any ideas for troubleshooting will be
> > > appreciated.
> > The most likely explanation is that something else is running against
> > the database between those times. Note: this process need not
> > originate from the database server itself, hence nothing in Task
> > Manager, Scheduled Tasks and DBA_JOBS.
> > Monitor V$SESSION for any suspect sessions.
> > HTH
> > -g
> I agree, and the first thing I would look for is some performance
> monitoring tool!
> When I was taking networking (circa 1982) in school, my professor was
> the fellow who had done the arconet, which connected AM/PM minimarts
> with a 9600 multidrop line. It had just been shutdown due to
> insufficient performance. Anyhow, he told a story which totally
> cracked me up. I've posted it before, but can't remember where, so
> apologies to those who've heard this before. Imagine a thick
> Hungarian accent...
> As I recall the story went, a particular subnet would shut down every
> night at 9PM. They tried a number of tools (in those days, one wrote
> ones own), and could only find that some noise started at that time.
> Finally he went to one of the stores involved and waited until 9, and
> sure enough it went down. He plugged in a phone (in those days, it
> was analog), and heard "THIS IS THE VOICE OF GOD!"
> Turns out, a large AM transmitter was nearby, and would start
> broadcasting a Christian radio show at 9PM every night, overwhelming
> the data signal via induction.
> I've also worked in a couple of industrial areas where the place next
> door would turn on large machines at particular times, affecting
> hardware that was not isolated enough. Even my current customer
> recently got affected by some transient packet storm that overwhelmed
> one of an hp-ux machine's network interfaces, killing telnetd and the
> console. It's a dirty, dirty world.
> jg
> --
> is bogus.
> At least one web page is still up: Hide quoted text -
> - Show quoted text -

FRom the beginning we suspected Network to be an issue, We contacted our Networking departament, They monitored Network, could not find any thing. I have run perfstat, I have run Window's perfmon (for monitoring cpu, disk, memory usage..), do n''t see anything different between before 3:00PM and after 3:00PM/ It really baffels me that for weeks no one has clue on cause of the problem which happens consistenetly. Received on Mon Oct 22 2007 - 13:04:13 CDT

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