Types of ETL Testing

Types Of Testing
Testing Process
Production Validation Testing
 “Table balancing” or “production reconciliation” this type of ETL  testing is done on data as it is being moved into production systems.  To support your business decision, the data in your production systems has to be in the correct order.  Informatica Data Validation Option provides the ETL testing automation and management capabilities to ensure that production systems are not compromised by the data.
Source to Target Testing (Validation Testing)
Such type of testing is carried out to validate whether the data values transformed are the expected data values.
Application Upgrades
Such type of ETL testing can be automatically generated, saving substantial test development time. This type of testing checks whether the data extracted from an older application or repository are exactly same as the data in a repository or new application.
Metadata Testing
Metadata testing includes testing of data type check, data length check and index/constraint check. 
Data Completeness Testing
To verify that all the expected data is loaded in target from the source, data completeness testing is done. Some of the tests that can be run are compare and validate counts, aggregates and actual data between the source and target for columns with simple transformation or no transformation. 
Data Accuracy Testing
This testing is done to ensure that the data is accurately loaded and transformed as expected.
Data Transformation Testing
Testing data transformation is done as in many cases it cannot be achieved by writing one source SQL  query and comparing the output with the target.  Multiple SQL queries may need to be run for each row to verify the transformation rules.
Data Quality Testing
Data Quality Tests includes syntax and reference tests.  In order to avoid any error due to date or order number during business process Data Quality testing is done.
Syntax Tests: It will report dirty data,  based on invalid characters, character pattern, incorrect upper or lower case order etc.
Reference Tests: It will check the data according to the data model.  For example: Customer ID
Data quality testing includes number check, date check, precision check, data check , null check etc. 
Incremental ETL testing
This testing is done to check the data integrity of old and new data with the addition of new data.  Incremental testing verifies that the inserts and updates are getting processed as expected during incremental ETL process.
GUI/Navigation Testing
This testing is done to check the navigation or GUI aspects of the front end reports.