satyaneerumalla

 Profile Answers by satyaneerumalla Questions by satyaneerumalla

• Aug 21st, 2006

 

Lookup transformation is not a join operation.

In simple terms you will check in a table whether any column satisfies the condition you are specifying. If it satisfies one or more columns of the satisfied row are  used in the mapping.

please follow this example carefully by imagining structures of the tables.

ex:

take source table REWARDS which contains empids who got rewards.

import the already existed EMP table into lookup transformation. then lookup or match empid fields of both tables. If you find a match means lookup is succeded. You can pass on required columns of matched rows for further processing.

Here take sal attribute and by using expression attribute increment salary by Rs1000/-. 

sarath kumar

• Aug 23rd, 2006

 

Hi

Lookup transformation is mainly used when the informatica server does not have enough considerable information.

It is used to lookup data in a relational table, synonym or view. Informatica server quieries the lookup table based on the lookup ports in the transformation.

Main use of Lookup transformation is

1. Get related values

2. Perform caliculations

3. To Update slowly changing dimensions( here we use target table as lookup table and again connect to target table)

It is often used to find present values like currency exchange rates, stocks..

calltomadhu

 Profile Answers by calltomadhu 

• Sep 23rd, 2006

 

hi

through sheduling

pradeeshkumar

 Profile Answers by pradeeshkumar 

• Aug 19th, 2010

 

Lookup is not a join. Lookup is more similar to the real world example, you are conducting a interview and you have the list of registered candidates in hand. In oreder to see whether a candidate is registered or not, you'll look into the list and then verify. That's it.