Re: What would happen if..?

From: Yong Huang <>
Date: Sat, 15 Mar 2008 15:15:09 -0700 (PDT)
Message-ID: <>

On Mar 14, 10:23 am, Ben <> wrote:
> EE, aix 5.2 64bit
> I have seen the metric reported in Enterprise Manager several times
> for "Current Open Cursors Count" on one of our database's home page/
> screen. It's reporting it at 7828. This particular system has about
> 1200 individual sessions logged on during peak hours and drops down to
> about 500 during off hours. OPEN_CURSORS is set to 500 in this
> database.
> What I don't understand is exactly why this metric is being reported
> to me and if it is just a default value that it has decided once there
> are x number of open cursors the threshold has been crossed and I'm
> going to raise a warning.
> I guess what I'm really asking is, is there some magic number of open
> cursors that I should be worried about, or is it just reporting this
> open cursor count because by default there is a threshold set at 1200
> open cursors that it is at warning status.
> Is there some maximum number of open cursors for the entire instance
> that if we reach that number it's going to blow up shoot sparks out of
> the back of the server....


You may already know this. But just in case. EM's alert at 1200 opened cursors is system wide, not for a single session. So it doesn't make much sense. Instead of looking at v$sysstat for 'opened cursors current' as EM does, you can write your own monitoring script based on v$sesstat for statistic# 3 (10g). If it either approaches a preset limit such as 90% of open_cursors or (more challenging) monotonically goes up for a preset period of time, send an alert.

Yong Huang Received on Sat Mar 15 2008 - 17:15:09 CDT

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