Informatica Qs

1. Explain the Architecture of informatica.
A. PowerCenter and PowerMart provides the following integrated components:

- Informatica repository. The Informatica repository is at the center of the Informatica suite. You create a set of metadata tables within the repository database that the Informatica applications and tools access. The Informatica Client and Server access the repository to save and retrieve metadata.

- Informatica Repository Server. The Informatica Repository Server manages connections to the repository from client applications. It inserts, updates, and fetches objects from the repository database tables. It also maintains object consistency.

- Informatica Client. Use the Informatica Client to manage users, define sources and targets, build mappings and mapplets with the transformation logic, and create workflows to run the mapping logic. The Informatica Client has four client applications: Repository Manager, Designer, Workflow Manager, and Workflow Monitor.

- Informatica Server. The Informatica Server extracts the source data, performs the data transformation, and loads the transformed data into the targets.

2. Give the name of few transformations
A. Commonly used transformations are
Source Qualifier, Expression, Aggregator, Joiner, Lookup, Update Strategy, Filter,
Normaliser, Stored Procedure, Sequence Generator, etc.

3. What is the difference between connected and unconnected lookup?
A. An unconnected Lookup transformation exists separate from the flow of the mapping.
You write an expression using the :LKP reference qualifier to call the lookup within
another transformation.
While the connected lookup forms a part of the whole flow of mapping.
Unconnected Lookup can return maximum of one column
Connected Lookup can return multiple columns

4. What is Normalizer transformation ? Have you used it in your project?
A. Used primarily for COBOL sources, which are often stored in a
denormalized format. It is used to normalize records from COBOL and relational
sources

5. What are the system variables available in Informatica?
A. SYSDATE, SESSTARTTIME, PROC_RESULT

6. Minimum how many transformations are needed for a mapping?
A. Three. These are source definition, source qualifier and target definition.

7. Explain worklet
A. A worklet is an object that represents a set of tasks. It can contain any task available
in the Workflow Manager.

8. If two tables are present in source database and one has to get corresponding data from second. Which option is preferable- use of lookup or use of source qualifier ?
A. If table size is big then source qualifier is preferred.

9. What are shortcuts in informatica?
A. Shortcuts allow you to use metadata across folders without, making copies
ensuring uniform metadata.

A shortcut inherits all the properties of the object to which it points.
When the referred object changes, the shortcut inherits the changes.
Shortcuts allow you to reuse an object without creating multiple
objects in the repository, which also saves space in the repository.

10. If update strategy is used in a mapping, what would be the setting at the time of session creation?
A. Property “Treat source rows as” should be set as “Data driven”

11. For a flat file data source, do we mention number of sorted ports in properties of SQL qualifier?
A. No

12. Explain about your current project?
A. As per bio-data

13. What scheduler do you use in your project?
A. Informatica Scheduler and Cron

14. Tell me few unix commands.
A. cp , rm, echo, kill, grep, ps, head, tail, cat, touch etc.

15. Explain wc command.
A. This command counts the number of lines, words, and bytes or characters in a file.

16. How will you output 16th row of a file in unix?
A. Use following command
head -16 | tail –1

17. Which database is being used in your project?
A. Oracle

18. What will be the select statement to read data form a table if that table is already being used by some other SQL/mapping?
A. In UDB, even a select statement creates a lock. To avoid this situation following
query should be used

SELECT …….
FROM ……..
WHERE …..
FOR READ ONLY

19. What is a primary key and foreign key?
A. Primary and foreign keys are the most basic components on which relational theory is
based. Primary keys enforce entity integrity by uniquely identifying entity instances.
Foreign keys enforce referential integrity by completing an association between two
entities.