Re: Cache Hit Ratio from system views

On Tue, 21 Aug 2007 18:57:18 -0000, Steve Howard <stevedhoward_at_gmail.com> wrote:

>
>If your BCHR is 50% on one system and 99% on another (once again,
>identically coded, hardware, etc.)...
>
>is that not an indication that your DBA *may* have forgotten a couple
>of zeroes for db_cache_size parameter?
>
>I am truly curious, as this should be a yes or no answer. If the
>answer is anything other than no, then it does have *some* value.

This is not the issue.
The issue is whether you meet your SLA, and/or whether end-users complain.
In one particular system I rectified all untuned statements. Then an 'expert' developer of the 3rd party vendor came in. He reverted *everything* and now no statement is using any index *by design*. BCHR is 20 percent.

End-users don't complain!

-- 

Sybrand Bakker
Senior Oracle DBA