Specialization and Generalization

Specialization and Generalization

Specialization: dividing an entity into multiple entities based on the unique characters between them.

E.g. In below employee table .the employees who are fresher has a  “trainer-name” , but with out any "Project"

name	age	role	trainer	Project
Amit	21	fresher	smith
Bill	30	developer		Prj-A

split this table into two tables based on the unique characteristics

Developers name age Project   Bill 30 Prj-A Fresher name age trainer Amit 21 smith ..

Generalization: creating a super entity through identifying the common attributes between two or more entities.

with the same example as mentioned above :

Developers name age Project   Bill 30 Prj-A Fresher name age trainer Amit 21 smith

create a super entity based on the common properties found in both the tables (name , age)

Employees emp-id name age 1   Bill 30 2 Amit 21 Developer emp-id project 1 Prj-A Fresher emp-id trainer 2 smith