Re: buffer hit cache ratio

"Joel Garry" <joel-garry_at_home.com> wrote in message news:91884734.0312291517.620af707_at_posting.google.com...
> Isn't it a process of box ticking to _get_ you to the point of being
> able to focus on response time? Surely you aren't advocating starting
> with a default SGA on a new 6G system, when you have experience with a
> smaller system running similar stuff. Don't you set parameters to
> where you think they ought to be and then test? Even myths can be
> useful ROT.
>

I agree that database creation and setup should *largely* be a process of box ticking. SGA sizing process considered, disk layout created and confirmed, naming conventions followed, init.ora considered and created, to that extent I *really* like the template feature that dbca provides. Its the idea that to *tune* a poorly performing system the best approach is to complete a checklist of database internals, rather than try and find what is causing which processes to perform inadequately that I don't like.

You are correct about experience forming ones view. Mine is that once you have halfway sensible values for the buffer cache, shared pool etc. It is individual sessions that experience problems, not whole systems (though it can look like that if your monthly invoice production takes 52 hours to produce 700 invoices :( ).

-- 
Niall Litchfield
Oracle DBA
Audit Commission UK