An1:

In DB testing we need to check for,

1. The field size validation

2. Check constraints.

3. Indexes are done or not (for performance related issues)

4. Stored procedures

5. The field size defined in the application is matching with that in the db.

An2:

Database testing involves some indepth knowledge of the given application and requires more defined plan of approach to test the data. Key issues include :

1) data Integrity

2) data validity

3) data manipulation and updates.

Tester must be aware of the database design concepts and implementation rules