Informatica Interview question with answer for lookup Transformation

In below article , we will go through the some the Informatica Interview question based on the lookup transformation in Informatica. In last tutorial , we have gone through the detailed explanation of lookup Transformation.
You can find a good details of Lookup transformation here.

We also checked some of the example of connected and unconnected lookup transformation also.

Lets go through some of the Informatica Interview question on Lookup transformation.

Check here : Difference connected and unconnected Lookup Transformation here .

Que: What is a pipeline lookup transformation??

Ans :A pipeline lookup transformation is used to perform lookup on application sources such as JMS, MSMQ or SAP. A pipeline lookup transformation has a source qualifier as the lookups source.

Que: What are the different type of Sources for Lookup ?

Ans :

• Relational source or target definition in the repository
• Flat file source or target definition in the repository
• Table or file that the Integration Service and PowerCenter Client machine can connect to
• Source qualifier definition in a mapping

Ques. What is a lookup transformation?
Ans : A lookup transformation is used to look up data in a flat file, relational table, view, and synonym.

Ques: What are the tasks of a lookup transformation?

Ans : The lookup transformation is used to perform the following tasks?

• Get a related value: Retrieve a value from the lookup table based on a value in the source.
• Perform a calculation: Retrieve a value from a lookup table and use it in a calculation.
• Update slowly changing dimension tables: Determine whether rows exist in a target.

Ques: . What is "Output Old Value on Update"?
Ans : This option is used when dynamic cache is enabled. When this option is enabled, the integration service outputs old values out of the lookup/output ports. When the Integration Service updates a row in the cache, it outputs the value that existed in the lookup cache before it updated the row based on the input data. When the Integration Service inserts a new row in the cache, it outputs null values. When you disable this property, the Integration Service outputs the same values out of the lookup/output and input/output ports.

Ques: . How do you configure a lookup transformation?

Ans : Configure the lookup transformation to perform the following types of lookups:

• Relational or flat file lookup
• Pipeline lookup
• Connected or unconnected lookup
• Cached or uncached lookup

Ques: What are the options available to configure a lookup cache?
Ans : The following options can be used to configure a lookup cache:

• Persistent cache
• Recache from lookup source
• Static cache
• Dynamic cache
• Shared Cache
• Pre-build lookup cache

Check here : Difference Static Cache and dynamic Cache  in Informatica here .

I also found a good article on Informatica Interview question on Lookup Transformation  here and here