Sort Stage Vs CPU utilization

dhanashreepanse · Post by **dhanashreepanse** » Fri Jan 18, 2008 2:40 am

I read that the sort stage in PX is a lot faster and it is recommended that by using this before the join stage would improve the job performance.
But at the same time, the CPU utilisation is also high.

How should one decide how many sort stages should be used in one job so as to keep the CPU utilisation within limits and also considering the fact that along with this job, there are 10-20 other jobs also running in parallel and they should also not be starved of resources.
Please share your thoughts on this.

Thanks in advance.

Regards,
Dhanashree

ray.wurlod · Post by **ray.wurlod** » Fri Jan 18, 2008 5:48 am

How long is a piece of string?

Seriously yours is not a question that can be answered without knowing the results of resource monitoring on your machine.

If you don't use a Sort stage or a link sort but a sort is required, then a tsort operator will be inserted when the score is composed. So you end up doing the sorting anyway.

How much total load the machine(s) can bear is a function of the total demand for resources of everything that is running simultaneously. Simple supply-and-demand economics. Supply is constant (until you buy more), demand can be monitored/measured.