Re: real time app. on Oracle

in article 0BhH8.33$mR1.191_at_news.oracle.com, Howard J. Rogers at dba_at_hjrdba.com wrote on 5/23/02 7:27 PM:

> The idea is that if I, the DBA, don't use all
> of my 100% allocation, the OLTP lot get 100% of whatever I have left behind.
> For that 'spill over' to happen, it is obvious that I must NOT be using 100%
> of the CPU in the first place.

Pete is right and Howard is right. Resource Manager is active at all times - but the plan (for CPU management) is only "in effect" when the CPU maxes out -

If the CPU is not maxed, all groups will share whatever CPU is available on a first come, first served basis. The aim is not to starve a group unless it is necessary. It's the Nike principle - if you can, just do it.

If you, as the DBA group, start to use 100% of CPU, then the OLTP and DSS group will starve.

If, you, as the DBA, only consume 80% of the CPU at level 1, then the OLTP and DSS group will share any remaining CPU equally, providing the CPU is not maxed out.

If the OLTP group then maxes out the remaining 20%, then the DSS group will start to starve.

In the same way, a 60/40 split at level one does not get applied until the CPU is at 100 %. So it's entirely possible that a consumer group with the 40% can actually use 99.999% of the CPU. Received on Thu May 23 2002 - 21:50:12 CDT