What Are The Advantages And Disadvantages In Relational Data Model?


1 Answers

Anonymous Profile
Anonymous answered
Advantages of Relational approach

The popularity of the relational database approach has been apart from access of availability of a large variety of products also because it has certain inherent advantages.

1. Ease of use: The revision of any information as tables consisting 0f rows and columns is quite natural and therefore even first time users find it attractive.

2. Flexibility: Different tables from which information has to be linked and extracted can be easily manipulated by operators such as project and join to give information in the form in which it is desired.

3. Precision: The usage of relational algebra and relational calculus in the manipulation of he relations between the tables ensures that there is no ambiguity, which may otherwise arise in establishing the linkages in a complicated network type database.

4. Security: Security control and authorization can also be implemented more easily by moving sensitive attributes in a given table into a separate relation with its own authorization controls. If authorization requirement permits, a particular attribute could be joined back with others to enable full information retrieval.

5. Data Independence: Data independence is achieved more easily with normalization structure used in a relational database than in the more complicated tree or network structure.

6. Data Manipulation Language: The possibility of responding to ad-hoc query by means of a language based on relational algebra and relational calculus is easy in the relational database approach. For data organized in other structure the query language either becomes complex or extremely limited in its capabilities.

Disadvantages of Relational Approach

One should not get carried way into believing that there can be no alternative to the RDBMS. This is not so. A major constraint and therefore disadvantage in the use of relational database system is machine performance. If the number of tables between which relationships to be established are large and the tables themselves are voluminous, the performance in responding to queries is definitely degraded. It must be appreciated that the simplicity in the relational database approach arises in the logical view. With an interactive system, for example an operation like join would depend upon the physical storage also. It is, therefore common in relational databases to tune the databases and in such a case the physical data layout would be chosen so as to give good performance in the most frequently run operations. It therefore would naturally result in the fact that the lays frequently run operations would tend to become even more shared.

While the relational database approach is a logically attractive, commercially feasible approach, but if the data is for example naturally organized in a hierarchical manner and stored as such, the hierarchical approach may give better results. It is helpful to have a summary view of the differences between the relational and the non-relational approach in the following section.

Answer Question