Re: How to setup RAC to avoid Inter-Instance Parallelism

From: Mathias Magnusson <>
Date: Wed, 10 Jun 2009 18:28:55 +0200
Message-ID: <>

Why is the parallell slaves on different instances a problem. I think you need to understand why that causes a problem in order to devise a solution. What happens if you log on to just one of the nodes instead of to the cluster?

WHat is the main wait event?


On Wed, Jun 10, 2009 at 6:10 PM, GBA-DBA <> wrote:

> Hello list,
> I have a two node RAC setup
> serv1 - instance 1
> serv2 - instance 2
> We are using parallel query for batch processing. The time to complete
> batch is ok when we run in a non clustered environment (that's what we have
> in dev and integrated testing) but when we move the batch to a clustered
> testing environment similar to prod everything takes 2 or 3 times longer.
> I have noticed that some of the slave processes go to instance 1 and some
> of them go to instance 2. I would like to confine the parallel slaves to one
> instance but I don't fully understand how to setup the instance_groups and
> parallel_instance_groups to achieve this.
> Could anyone help me please?
> Thanks in advance.
> --
> Regards

Received on Wed Jun 10 2009 - 11:28:55 CDT

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