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Table of contents
What is Generalization in DBMS?
Uses of Generalization in DBMS
Example Based on Generalization in DBMS
Advantages of Generalization in DBMS
Disadvantages of Generalization in DBMS
Difference Between Generalization and Specialization in DBMS
Frequently Asked Questions
What are some tools for implementing generalization in DBMS?
What is generalization in DBMS?
What are the advantages of generalization in DBMS?
Last Updated: Mar 27, 2024

Generalization in DBMS

Author Narayan Mishra
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Ashwin Goyal
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In the realm of database management, efficient storage and retrieval of information are of utmost importance. When the goal is to streamline intricate data structures and create more abstract representations of entities, this procedure is referred to as generalization. It stands as a fundamental concept within DBMS.

Generalization in DBMS

In this article, we will discuss about generalization in DBMS. We will explain why it is used. We will also explore its advantages and disadvantages. At the end of this article, we will discuss an example to understand this concept. 

So, let's get started!!

What is Generalization in DBMS?

Generalization is a process in DBMS of simplifying the complex data structure. It uses the common attributes of entities and combines them to form a new entity. It follows a bottom-up approach. It starts with lower-level entities or classes and then builds upwards to create higher-level, more generalized entities. It describes superclass and subclass relationships.

Suppose we have an entity called “ninjas” and another entity is “course enrolled”. We can combine them by checking their common attributes. Assuming that the common attribute is "name," we can establish a new entity called "ninjadetails". We can combine and store this information within a new entity. 

**Now you might be wondering why to use generalization in DBMS.

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Uses of Generalization in DBMS

Generalization in DBMS serves several purposes. The following are the uses of generalization in DBMS:

  • It is used to simplify the complex data structures. It does so by taking common attributes from different entities
  • It is used to improve the query efficiency
  • It enables inheritance between two or more entities. It helps to inherit the attributes and behavior from the parent entity to the child entity
  • It is used to simplify data management. If we change any common attribute in the higher-level entity, it will also reflect on the lower-level entity. There is no need to update manually
  • It helps to reuse common attributes. If we want to recreate a similar entity for another purpose, then we can generalize the common attributes
  • It helps to maintain data integrity and consistency

Now, let us discuss the concept of generalization in DBMS with the help of an example.

Also read, File System vs DBMS

Example Based on Generalization in DBMS

Suppose we have two entities called a Student and a Teacher. Each entity has its ID, Name, Contact Details, and Address. 

Let us look at these entities.

student and teacher entity

As we can see, there are some attributes that are common in both entities. The common attributes are Name, Contact Details, and Address. So, we can generalize them into a single entity called Person. A person can be a student or a teacher. Let's see what will happen after generalization:

generalized entity

Here is the generalized entity Person.

Advantages of Generalization in DBMS

There are several advantages of generalization in DBMS:

  • When we generalize entities, it facilitates the establishment of relationships among tables by identifying common attributes
  • It helps to simplify the structuring of database management and the recognition of pertinent attributes
  • When we separate common attributes to form a generalized entity, it eliminates data redundancy. So, there is no need to remove duplicate attributes in separate tables. We can retrieve the information from the generalized entity table
  • It follows a bottom-up approach. It focuses mainly on attributes, within the database, as opposed to focusing primarily on high-level entities
  • It supports the modeling and management of complex and interconnected data. This makes it more suitable for applications like GIS(Geographical Information Systems) and hierarchical organizational structures

Disadvantages of Generalization in DBMS

Along with the advantages, generalization also has some disadvantages:

  • It can add complexity to the database schema. When we deal with multiple levels of hierarchy and relationships, it becomes more complex to understand
  • It can add overhead in terms of storage and processing
  • When we deal with a well-structured hierarchy of entities using generalization, it requires careful consideration and design
  • It is not supported by all DBMS systems, mainly in traditional relational databases
  • When we have complex queries that involve multiple levels of generalization and inheritance, it can be challenging to optimize them

Difference Between Generalization and Specialization in DBMS

Generalization and specialization are both the process used to produce enhanced entity relationship diagrams. There are several differences between these two processes:

Generalization  Specialization
It follows the bottom-up approach. It follows the top-down approach.
It combines multiple entities into a higher-level entity with common attributes and relationships. It divides a higher-level entity into multiple lower-level entities with different attributes and relationships.
It can be applied to a group of different entities. It can only be applied to a single entity.
It results in a decrease in the schema's size. It results in an increase in the schema's size.
Inheritance is not used in this process. Inheritance is used in this process.

Frequently Asked Questions

What are some tools for implementing generalization in DBMS?

There are several tools available to implement generalization in DBMS. Popular DBMS systems like Oracle, MySQL, and Microsoft SQL Server provide tools and features for implementing Generalization through entity-relationship modeling.

What is generalization in DBMS?

Generalization in DBMS involves creating a higher-level entity from lower-level entities, capturing common characteristics. It simplifies data management and enhances abstraction.

What are the advantages of generalization in DBMS?

Advantages of generalization in DBMS include streamlined data organization, reduced redundancy, improved data retrieval efficiency, and simplified query formulation. It supports better data modeling and analysis.


In this article, we have discussed about generalization in DBMS. It comes as a survivor of simplifying data structures and improving data management. It also helps to improve query efficiency. If you want to learn more about DBMS, then you can check out our other articles:

We hope this article helped you to gain knowledge about generalization in DBMS. You can refer to our guided paths on the Coding Ninjas Studio platform. You can also consider our DBMS Course to give your career an edge over others.

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