what is the difference between lookup,merge,and join stage?

arun@sinmax · Post by **arun@sinmax** » Fri Jan 30, 2009 12:33 am

ray.wurlod · Post by **ray.wurlod** » Fri Jan 30, 2009 12:59 am

Moderator: please move to parallel forum

Did you bother to Search (this question has been asked and answered before) or to read the relevant chapters (one for each stage type) in the Parallel Job Developer's Guide?

fareeda_b · Post by **fareeda_b** » Fri Jan 30, 2009 2:04 am

Hi arun,

The Lookup stage is most appropriate when reference data is small enough to fit into physical (shared) memory.
Limit use of Sparse Lookup(for DB2 and Oracle reference tables)

For reference datasets larger than available memory, use the JOIN or MERGE stage.

thanks
fareeda

kduke · Post by **kduke** » Fri Jan 30, 2009 12:08 pm

fareeda

We tend not answer questions which may look like a job interview question.