Re: run time stats and x$ tables

Why bother with this hitratio, it is meaning less especially when you calculate it over an week !
There are better ways !

Anjo.

Ed Stevens wrote:

> I have begun tracking performance statistics on my Oracle databases.
> Right now I am focusing on cache miss ratio, using the following query:
>
> select
> p.bp_name buffer_pool,
> lpad(to_char(100 * sum(s.pread) / sum(s.dbbget + s.conget), '990.00')
> || '%', 13) miss_rate
> from
> sys.x_$kcbwds s,
> sys.x_$kcbwbpd p
> where
> s.set_id >= p.bp_lo_sid and
> s.set_id <= p.bp_hi_sid and
> p.bp_size != 0
> group by
> p.bp_name
> /
>
> (X_$kcbwds and x_$kcbwbpd are views that map directly to the tables
> X$kcbwds and x$kcbwbpd).
>
> My basic question is - when are numbers in these ?statistics gathering?
> tables updated, and when are they zeroed? At its roots, the above
> query is selecting PREAD, DBBGET, and CONGET from x$kcbwds, and
> bp_name from x$kcbwbpd. But I don?t really know for what time frame
> these numbers are derived. If I run this query every day for a week,
> and the database is never shut down, do Tuesday?s numbers also include
> Monday?s numbers?
>
> - Ed Stevens
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Tue Nov 02 1999 - 02:22:59 CST