Re: System statistics and dbfmbrc

On Jan 8, 2008 2:21 PM, Wolfgang Breitling <centrex_at_centrexcc.com> wrote:

> Quoting Niall Litchfield <niall.litchfield_at_gmail.com>:
> > it's one reason why I'm moving us to collecting
> > (optimizer) stats monthly as a matter of course with more frequent
> > collections the exception driven by proven need. Thanks for your
> > input.
>
> Contrary to my earlier statement of "sitting on the fence" I think if I
> were in
> a position to make a decision on system statistics strategy I would
> collect
> system statistics into a stattab table on a regular basis, maybe hourly if
> workload fluctuates heavily, or maybe longer intervals with the interval
> boundaries coinciding with major workload shifts such as day/online to
> evening/night/batch (in which case 8-hour intervals may make sense) and
> then on
> a weekly or monthly basis review that data and decide whether to update
> the
> dictionary system stats. I would not gather system stats directly into the
> dictionary.
>
>

What's that old line about "I know you understood what was meant by what I said, but I don't believe that you understand that what I said was not what I meant!"

The word optimizer in my sentence

 I'm moving us to collecting (optimizer) stats monthly as a matter of course with more frequent collections the exception driven by proven need.

should have read object. In other words I want to reduce the frequency of * object* stats collections from weekly (or in a couple of cases nightly) to monthly. The bullet point summary in the document that I am writing that prompted this question reads of system statistics

Determine appropriate values for system statistics over a period of a week, review the values every 3-6months.

-- 
Niall Litchfield
Oracle DBA
http://www.orawin.info

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