DSXchange

Anyone know if the performance of a PX job is hindered by having 7 separate lookup stages vs. 1 lookup stage doing 7 lookups?

Reason I have them busted out into 7 separate lookups is so that I can identify which lookup fails.

I have a scheme cooking to identify them via a single lookup, but wondering if there is a definite answer on "N lookup stages vs. 1 lookup stage doing N lookups".

Before you go there, I know I can code it up and try it.

Just wondering if it's a truism.

Thanks,
Craig

My feeling would be that one is better than many, because of the amount of work avoided buffering data between processes. Of course, diagnosis becomes ugly - but if it's only failed lookup you're interested in, then you have a Merge stage.