The relation model of the data base management system uses a tabular storage system for storing the data. “A data base management system developed on the relational model is termed as the relational data base management system or RDBMS in short form”.
Out of all the models available for DBMS this one is the most popular. E.F. Codd of IBM brought the relation model in to existence. He developed this model based up on the concepts of sets and relations of mathematics.
– Each row of the table consists of data related to a unique entity whereas each column stores data related to an attribute of the entity.
– The characteristic of simplicity is what that has made the relational data base management system so popular.
– The data is represented in such a way that it is easy to understand it and manipulate.
– Second advantage here is that the data is not bonded with the relationship between the two data items rather the relationships are maintained via the values of the columns.
– Most of the data bases that are available today either implement complete relational model or a part of it.
– To maintain the quality of the data base there are 3 aspects that should always be tested:
1. Actual data
2. Integrity of the data base
3. Functionality and procedures
– Every time a person uses a data base, he accesses it and either updates it or deletes it or appends something to it. – Then, the stability of the data base is disturbed and it becomes vulnerable to several bugs, errors and accidental modification.
– There are chances that the strength of the security system of the data base management system may reduce.
– Therefore, after the data base has been accessed by the user the data base should be tested in order to make it free of any errors and deliver a quality service every time.
– Such testing of the data base again and again ensures that it is free of errors.
– Though this is a new idea it’s been employed for testing application code nowadays.
– There are various situations when the testing of relational data base management system should be done.
– Firstly, whenever the quality of data is endangered, the data base should compulsorily be tested since the quality of data is considered to be an important corporate asset by most of the people.
– Another thing is that the relational data base management system operates on mission critical data and focuses up on mission critical functionality.
– Any wrong modification of the data by the functions can sometimes cause a huge loss and may also disappoint the user.
– Therefore, the functionality testing of the relational data base management system needs to be tested rigorously.
– Also, the present approaches that are applied for testing the relational data base management system are very inefficient.
– This calls for the need of performing the same tests again and again so that the rate of efficiency can be improved to some margin.
– By testing the whole data base again and again you get a concrete test suite to perform regression testing on the data base.
– Also, the data base should be tested whenever it encounters any modifications since modifications can sometime lead to loss of data.
– Immediate testing should be done ensuring that the modification was a valid one and not accidental.
– Other times when the testing should be done are:
1. Whenever there occurs an incorrect manipulation of the data through the use of views.
2. Whenever there occurs an incorrect join is performed with the help of non – key attributes.
3. Whenever there is an incorrect use of the integrity constraints.
4. Whenever a problem is caused with the data insertion, update or deletion because of the use of constraints such as check, unique and null.
Testing ensures the following 4 aspects:
3. Comprehension and