Is there any impact on perf while calling external routines

sandeep8.s · Post by **sandeep8.s** » Mon Nov 10, 2008 3:02 am

Hi,
I have to call external routine in my DataStage job to perform certain transfermation matching and filter.
Is there any issue on performance while using these external routines?

ray.wurlod · Post by **ray.wurlod** » Mon Nov 10, 2008 6:58 am

What is your definition of "performance" in an ETL context? Without knowing this it is not possible to answer your question. And what would be your alternative if the answer were to be "yes"?

sandeep8.s · Post by **sandeep8.s** » Mon Nov 10, 2008 7:51 am

By Performance I mean the time it takes in process while calling external procedure.

ray.wurlod · Post by **ray.wurlod** » Mon Nov 10, 2008 4:27 pm

Compared to what?

Naturally there is an overhead in making the initial call, but it's negligible and only occurs on the first row (on each node). After that the routine's code is in memory and its entrypoint address is known.