How do we call shell scripts from informatica?

You can use a Command task to call the shell scripts, in the following ways:
1. Standalone Command task. You can use a Command task anywhere in the workflow or worklet to run shell commands.
2. Pre- and post-session shell command. You can call a Command task as the pre- or post-session shell command for a Session task. For more information about specifying pre-session and post-session shell commands


What is latest version of Power Center / Power Mart?

Latest Ver of Power Center is 7.1 and Informatica stopped marketing powermart product.So right now powermart is not available in market.


Can we override a native sql query within Informatica? Where do we do it? How do we do it?

we can override a sql query in the sql override property of a source qualifier


Can we use procedural logic inside Infromatica? If yes how , if now how can we use external procedural logic in informatica?

We can use External Procedure Transformation to use external procedures. Both COM and Informatica Procedures are supported using External procedure Transformation


Techniques of Error Handling – Ignore , Rejecting bad records to a flat file , loading the records and reviewing them (default values)

Rejection of records either at the database due to constraint key violation or the informatica server when writing data into target table.These rejected records we can find in the badfiles folder where a reject file will be created for a session.we can check why a record has been rejected.And this bad file contains first column a row indicator and second column a column indicator.
These row indicators or of four types
D-valid data,
O-overflowed data,
N-null data,
T- Truncated data,
And depending on these indicators we can changes to load data successfully to target.