Sunday, 28 August 2016

Advantages and disadvantages of database system

Advantages of database system:-
                                              File processing system has many disadvantages. Database approach is used to solve the problem of file processing system. Some important advantages of database are as follow:
1.   Redundancy control:-
                               Redundancy means data is duplicated in the system and appeared many times in the system. But in database redundancy is control, redundancy control means that data appeared only once and is not duplicated.
For example the data of a student in college database stored in one table. The table can be accessed for different purpose. If student want to change address then the change is only made in one place due to this reason data is not duplicated in the system.
2.   Data consistency:-
                           Redundancy control means that data is consistent in database. Data appeared only once so it is easy to maintain. Any updation is required then data is updated at once it will effect at all places where that data is used in the database.
3.   Consistency constrain:-
                                Consistency constrain are the rules to enter data in the database. If these rules are not followed the data is not enter in the database. For example roll no of a student always is a numeric value (1, 2, 3……). If numeric digit is not entered in student roll no it will generate an error message.
Constrain can be applied to ensure that data is enter in a specific range etc. phone number always in a numeric digit.
4.   Data atomicity:-
                         Data atomicity means all steps to complete the process carried out as a whole or it should not take place at all. Database approach ensure data atomicity that means that data always consistent and correct.
For example a user deducts amount from an account A, and add amount in account B. if money is deduct from account A but does not add in account B this situation cause data inconsistent in database. Database does not allow such situation. In database approach either both step is carried out or not.
5.   Reduced development time:-
                                          In database data is more efficiently stored. So the program that used this data is easier to develop. So this reduced overall development time of application.
6.   Increased concurrency:-
                                    Two user access the same file at the same time this will cause the loss of information. A database system manage a concurrent access and ensure that such problem not occur.
7.   Data independence:-
                                In database approach data and application program are separated from each other. We change the storage structure of a data without changing the application programs.
8.   Compactness:-
                      Compactness means data is store in way that require less space in storage device. In database management system data is stored in compactness. It saves memory.
9.   Data security:-
                      Database provides a several level of security to protect data from illegal access. Security is maintains through password.  Not every use of database should be allowed to access all the data. For example data entry operator should only be able to enter data in database. Database provides a different level of security for different users of the system.

Disadvantages of database system:-
 Database approach has many advantages but some disadvantages of using database approach are as followed:-
1.    High cost of database system:-
2.    Higher hardware cost:-
3.    Higher programming cost:-
4.    More chance of failure:-
5.    Complexity:-

                                          






                                                             

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