INFORMATICA INTERVIEW QUESTIONS AND ANSWERS-2

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11. Can we use the mapping parameters or variables created in one mapping into another mapping?

NO. We can use the mapping parameters or variables only in the transformations of the same mapping or mapplet in which we have created the mapping parameters or variables.

12. How can we improve session performance in aggregator transformation?
Use sorted input. Sort the input on the ports which are specified as group by ports in aggregator.

13. Under what conditions selecting Sorted Input in aggregator may fail the session?

If the input data is not sorted correctly, the session will fail.
Also if the input data is properly sorted, the session may fail if the sort order by ports and the group by ports of the aggregator are not in the same order.

14. What is the default source option for update strategy transformation?

Data driven.

15. What is Data driven?

The Informatica server follows the instructions coded in the update strategy transformations within the mapping and determines how to flag the records for insert, update, delete or reject. If you do not choose data driven option setting, the Informatica server ignores all update strategy transformations in the mapping.

16. What are the tasks that source qualifier perform?

Joins the data originating from the same source database.
Filter records when the Informatica server reads source data.
Specify an outer join rather than the default inner join
specify sorted records.
Select only distinct values from the source.
Create a custom query to issue a special SELECT statement for the Informatica server to read the source data.

17. What is the difference between STOP and ABORT options in Workflow Monitor?

When we issue the STOP command on the executing session task, the Integration Service stops reading data from the source. It continues processing, writing and committing the data to targets. If the Integration Service cannot finish processing and committing data, we can issue the abort command.

In contrast, ABORT command has a timeout period of 60 seconds. If the Integration Service cannot finish processing and committing data within the timeout period, it kills the DTM process and terminates the session.

18. How to delete duplicate rows using Informatica?

Scenario 1: If the source system is a relational database, How do you eliminate duplicate rows?

If the source system is a Relational Database, to eliminate duplicate records, we can check the Distinct option of the Source Qualifier of the source table and load the target accordingly.

Scenario 2: If the source data is from flat files, How do you eliminate duplicate rows?

We can use ‘Distinct’ property in Sorter Transformation to eliminate records from flat file sources, but we can’t use source qualifier SQL override for flat files.

But If you select the Distinct option in Sorter, all the ports will consider as key ports.

Put one Aggregator and select the Group By for one column.

We can also use Unix command i.e. sort and uniq in pre-session to avoid duplicate records in the file.

19. What is the difference between connected and connected lookups?

Go through this page for the answer.

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