1. What are the problems which arise when the Database state is
ignored while testing a database application?

Answer: Database state plays an important role in database application
testing. Ignoring it will cause following issues in tesint database
application.
1). both expected value and actual value of executing a database
application on a given input are depedent on the database state before
execution. If we don't consider the database states, we can't get
information of what would be expected value of execution just based on the
input and output.

2). After exeuction, if we don't have the database state information, we
can't tell whether the ouput of execution is actually right or not.

In all, if we don't consider database state before and after execution of
database application, the relationship between input and output of
database application is non-determinstic, which makes testing impossible.



2. One of the important issues in testing databases is the role of
the database state. Discuss three possible approaches to dealing with
this.

Answer: there are three ways to deal with it.
1). ignore database state. This way is easy and simple. However, it's not
useful for testing database application.
2). treat database state as an aspect of environment of the application.
When testing database application, we need to explicitly consider the
impact of environment on input and output.
3). treat database states as a part of input and output space.
The second way and third way are equivalent if we can model environment in
sufficient detail. However, these two ways would cause "controllability"
and "oberservability" prolem which can be solved by poplating databse
states with meaningful values before execuation and checking database
states after execution.

3. What's the difference between testing database management
system and testing database application?

Answer: This paper deal with testing database application.
Testing database application focus on testing database.
There is difference between database and DBMS. Database is a collection of
interrelated data. DBMS is an application which provides an interface for
querying and/or updating data in a database.
Testing database is to focus on the data stored in the database, the
relationship between the data.
Testing DBMS (such as MySQL, Oracle) covers more, which includes testing
the interface of DBMS, testing the query lanaguage, triggers, views ect.