Ideal condition for using sparse Look up

opdas · Post by **opdas** » Sat Jul 22, 2006 6:26 am

Hi All,

What would be an ideal condition for using sparse look up and when should we avoid the temtation of using it.

ArndW · Post by **ArndW** » Sat Jul 22, 2006 2:00 pm

A pretty good time to think about using a sparse lookup is when your lookup contains 1 million rows and your incoming data stream contains a few hundred.

ray.wurlod · Post by **ray.wurlod** » Sat Jul 22, 2006 6:29 pm

More precisely, your main input stream can contain very many rows too, but only a small number distinct lookup key values.

The idea of a sparse lookup is to be able to avoid loading a huge reference table into either a virtual Data Set or Lookup File Set.