Re: Resource Manager and PARALLEL_DEGREE_LIMIT_P1

schonlinner_at_yahoo.com wrote:
> Hi,
>
> we have an Oracle 10g database here and want to use the resource
> manager. We created a plan and set PARALLEL_DEGREE_LIMIT_P1 of a
> consumer group to 1.
>
> What we wanted to achieve is, that each single user of that specific
> consumer group can only have a single process, thus only a single CPU
> (of our 2 CPU server), so users in other consumer groups can perform
> real parallel queries using both processors.
>
> I looked at v$session and there the users indeed have the proper
> consumer group assigned, thus the plan is in effect and the correct
> consumer group is assigned.
>
> But when a user performs a query, I can see 4 processes on Unix which
> all perform parts of the query. Do I misunderstand something?
>

[...]

Perhaps try Note:240877.1 on Metalink?

Are you sure there is a one-to-one correspondence between Unix processes and the parallel slave sets of each individual user session? Can you provide ps output showing details of the four processes, as well as the v$session information from the same time period?

It might be simpler to just focus on overall CPU allocation. The resource manager in general only enforces CPU allocations when it needs to (at least in 9i, I haven't used it under 10g yet). Think of a car pool (High Occupancy Vehicle) lane on the freeway -- when traffic is light and the HOV's are not being delayed, then no restrictions on anyone are enforced. However when the traffic gets heavy enough (rush hour) to start impacting the HOV's, then the limits are enforced for non-HOV's. This is true for CPU allocation, however I'm not sure if it's true for parallel degree limits.

-Mark Bole Received on Tue Aug 23 2005 - 12:49:53 CDT