Entity set or entity type, Database Management System

Assignment Help:

A collection of a same kind of entities is known as an Entity Set or entity type.

Example:

For the COLLEGE database defines earlier objects of concern are Students, Faculty, Course and departments. The sets of all the students' entities form a entity set STUDENT. Likewise collection of all the courses creates an entity set COURSE.

Entity sets require not be disjoint. For example - an entity may be part of the entity set STUDENT, the entity set FACULTY, and the entity set PERSON.


Related Discussions:- Entity set or entity type

Keys - relational database integrity, Candidate Key:  In a relation R, a ca...

Candidate Key:  In a relation R, a candidate key for R is a subset of the set of attributes of R, which have the differnt two properties: (1)        Uniqueness:                N

Spanned and unspanned organisation, Spanned and unspanned organisation? ...

Spanned and unspanned organisation? Spanned and unspanned organization: If records are not permited to cross block boundaries then the organisation is called unspanned record

Non-redundant cover and canonical cover, Given the following set of functio...

Given the following set of functional dependencies {cf?bg, g?d, cdg?f, b?de, d?c} defined on R(b,c,d,e,f,g) a.Find a non-redundant cover. b.Find a canonical cover.

What is the meaning of recovery, What is the meaning of Recovery? In d...

What is the meaning of Recovery? In deferred update methods, if a transaction fails before arriving its commit point, it will not have altered the database in any way, so UNDO

E-r diagram, Let us now make the E-R diagram for the student database as pe...

Let us now make the E-R diagram for the student database as per the explanation given in the previous section. We can also states the overall logical structure of a database usi

Union - basic set operation, UNION If R1 and R2 are two union compatibl...

UNION If R1 and R2 are two union compatible relations then R3 = R1 ∪ R2 is the relation having tuples that are either in R1 or in R2 or in both. In case, R3 will have tuples

Database, why are older data models are being replaced by new data models

why are older data models are being replaced by new data models

Define a relation in dbms, Define a relation ? Relation - A relations...

Define a relation ? Relation - A relations is a named two-dimensional table of data. Mathematically, a relation can be described as a subset of the cartesian product of a lis

What you understand by client-server environment, Problem: a) Briefly d...

Problem: a) Briefly describe what you understand by Client-Server environment b) The File Server is a simple form of Client-Server. Describe the principles of the File Serve

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd