What are the things to consider while testing ETL ?

The process of Testing the web based application and ETL application is quit diffrent.the major difference is in web based application we test the GUI part of the applicaytion as well as the main functional tesitng.but as it in ETL first

We have to understand the source structure like how many records are comming from source and how many records are loaded in to the target this is the basic motivation for testing the ETL. then how many records are rejecting and waht is the reason for rejecting.

Second we have to test the Back-end data driven test.

We have to test ETL components by execuitng SQL PL/SQL queyries.

We have to test the mapping naming convertion is done with respect to SRS.


Things to be considered :
1.Check we can get the existing data
2.Check we can clean up the data
3.Check we can add new data
4.Check we can merge data
5.Check for the limitation of the data
6.Check for the security purpose of using data
7.Check whether it is overlimited how much time we needed to get from the extraction