Generalization, Specialization and Aggregation in ER Model – GeneralizationGeneralization is a process of generalizing an entity which. Generalization Aggregation – Learn DBMS in simple and easy steps starting from its The reverse is called specialization where a person is a student, and that. Generalization Aggregation – The concept of generalization (specialization) is associated with special types of entities known as superclasses and subclasses, .
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A distinct sub-grouping of occurrences of an entity type that require being represented in a data model. Aggregration is a process when relation between two entities is treated as a single entity.
This special kind of relationship is termed as an aggregation.
The Enhanced ER Model
Speculation Specialization is the opposite procedure of Generalization Collection Generalization in DBMS Speculation is an abstracting procedure of review sets of items as a solitary general class by focusing on the general attributes of the constituent sets while stifling specialiation overlooking their disparities.
In this chapter, you will learn about the main two important concepts. So it is a top-down methodology in which one larger amount substance can be separated into two lower level element. Notation of Generalization Generalization is represented by a triangle with a line. A generalization is a bottom-up approach. In this way, the two deliberation instruments used to model data: Since the s there has been a rapid amplification in the development of many new database systems that have more demanding database requirements than those of the traditional applications.
Generalization is a Bottom up process. Answered on 24th Jul,95 Views. Aggregation in DBMS Conglomeration is the procedure of aggregtaion data on an item, in this way abstracting a larger amount object.
In the below-mentioned figure, whale, shark, and dolphin are generalized as fish, i. Generalization specilaization a bottom-up approach in which two lower level entities combine to form a higher level entity. For example, a particular student named Mira can be generalized along with all the students. In simple terms, Aggregation is a process when relation between two entities is treated as a single entity. Aggregation represents relationship between a whole object and its component.
In specialization, a group of aggregayion is divided into sub-groups based on their characteristics.
Inheritance is an important feature of Generalization and Specialization. But in a company, persons can be identified as employee, employer, customer, or vendor, based on what role they play in the company. Comments Edit Answer Report. An example of aggregation is the ‘Teacher’ entity following the ‘syllabus’ entity act as gneeralization single entity in the relationship.
In this way, it is a base up methodology as two or lower lever substances are consolidated to shape a more elevated amount element. For example, Saving and Current account types entities can be generalised and an entity with name Account can be created, which covers both.
Generalization, Specialization and Aggregation Concepts in DBMS
As the complexity of data increased in the late s, it became more and more difficult to use the traditional ER Model for database modelling. The reverse is called specialization where a person is a student, and that student is Mira. Specialization is a process of identifying subsets of an entity that shares different characteristics.
The reflection is the instrument used to shroud the unnecessary points of interest of an arrangement of articles.