Informatica interview questions and answers part 2

Part1[1-7]  Part2[8-14]  Part3[15-23]  Part4[24-30]  Part5[31-37]  Part6[38-44]
Part7[45-51]

8.What are the types of data warehouses?
Ans - Following are the different types of data warehouses

• Data Mart 
• ODS (operational data store)  
• Enterprise Data Warehouse

9.What are the different types of metadata that stores in repository?
Ans - The different types of metadata that stores in repository are Source definition, Target definition, Mappings,Transformations and Mapplet.

10.What are an Expression transformation?
Ans- Expression transformation is a Passive and Connected transformation. It can be used to calculate values in a single row before writing to the target.

11.What are the differences between OLTP and OLAP?

Ans - Following are the differences    
    OLTP focuses on day to day transaction. OLTP gives Data Stability, it is dynamic and highly normalized.

    OLAP is static until it is refreshed, it is demoralized. OLAP focuses on future predictions and decisions

12.What is aggregated cache?
Ans - Aggregate cache is a temporary memory location that stores the input data values when the aggregation calculation is being carried out.

13.Why do we need to reinitialize aggregate cache?
Ans - It is needed to remove the previous data present in the aggregate cache and so that it can be used by the new source.

14.What is Dimension Table?
 Ans - It contains data used to reference data stored in the fact table. Has Fewer rows,Primarily character data,One primary key and Updatable data.

Part1[1-7]  Part2[8-14]  Part3[15-23]  Part4[24-30]  Part5[31-37]  Part6[38-44]
Part7[45-51]