Re: What would happen if..?

From: Ben <benalvey_at_yahoo.com>
Date: Fri, 14 Mar 2008 09:49:38 -0700 (PDT)
Message-ID: <b76e09eb-1fe1-41bb-8498-f7ef19b0a9d9@b64g2000hsa.googlegroups.com>


On Mar 14, 12:32 pm, hpuxrac <johnbhur..._at_sbcglobal.net> wrote:
> On Mar 14, 12:23 pm, Ben <benal..._at_yahoo.com> wrote:
>
>
>
>
>
> > 10.2.0.2 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....
>
> Do you understand what an open cursor is and why it has been set to
> 500 for the instance you are ( apparently ) supporting?
>

honestly there are a lot of settings in our system that I look back on and couldn't begin to explain accurately why they were set to what they are or what the previous dba was thinking when he did something. I do know what cursors are though, but why 500 was decided on the "correct" number, nope, no idea, I wasn't part of that decision making process. We had layoffs a few years back and our sole dba was one of them, so now I'm sole dba and the past dba didn't really keep notes.

> Since there are no silver bullets there also are no magic numbers
> here.

didn't think so. I'm assuming 1200 was the default number set for the metric in oem. It doesn't hurt to ask for others input though.

> Well except for if you have a session that needs more open cursors
> than your instance is configured to support well that can be something
> that needs looked at and adjusted.  That's similar to the
> consideration for how many processes your instance needs to support.- Hide quoted text -
>
> - Show quoted text -
Received on Fri Mar 14 2008 - 11:49:38 CDT

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