Entity identifier key attributes, Database Management System

Assignment Help:

An entity type usually has an attribute whose values are distinct for every individual entity in the collection. Such an attribute is known as a key attribute and its values can be used to recognize each entity uniquely.

Strong entity set: The entity types having a key attribute are known as strong entity types or regular entity types.

  • EXAMPLE: The Student entity has a key attribute RollNo which uniquely recognized it, hence is a strong entity.

Attributes

Let us first answer the question:

What is an attribute?

An attribute is a property used to define the specific feature of the entity. So to define an entity entirely, a set of attributes is used.

For example, a student entity may be defined by the student's name, address, age, course, etc.

An entity will have a value for every of its attributes. For example for a specific student the following values can be assigned:

RollNo: 1234

Name: Supriya

Age: 18

Address: B-4, Mayapuri, Delhi. Course: B.Sc. (H)


Related Discussions:- Entity identifier key attributes

Read-set(t) and timestamps-optimistic concurrency contents, read-set(T) : E...

read-set(T) : Each data items that are read by a transaction T Timestamps : for all transaction T, the start-time and the end time are reserved for all the three phases.

Structure of client server systems, Structure of Client Server Systems: In ...

Structure of Client Server Systems: In client/server architecture, clients show users who require services while servers give services. Both client and server are a combination of

What do you understand by raid, What do you understand by RAID? Explain RA...

What do you understand by RAID? Explain RAID Level 4 and Level5? RAID - It is stands for Redundant Array of Inexpensive Disks (as named by the inventor), or alternatively Re

Compare the nested-loop join and block-nested loop join, Compare the Nested...

Compare the Nested-loop join and block-nested loop join Ans: Nested  loop join - It is costly as worst case cost, no. of block accesses needed is n r * b s + b r   where b

Transactions and concurrency management, Transactions And Concurrency Manag...

Transactions And Concurrency Management  Introduction One of the main benefits of storing data in an integrated repository or a database is to permit sharing of it betwee

Database security, Ask questiwhat is row indicator in database on #Minimum...

Ask questiwhat is row indicator in database on #Minimum 100 words accepted#

Glory be, what does glory be mean

what does glory be mean

Oracle/sql, can you create a database for me in oracle/sql

can you create a database for me in oracle/sql

Give two profit of reuse of code, Give two profit of Reuse of Code. Re...

Give two profit of Reuse of Code. Reusing the implementation . Place existing class directly inside a new class. The new class can be made up of any number and type of the oth

Computer, 1. Will you advise that your organization uses open source softwa...

1. Will you advise that your organization uses open source software and why? 2. Why is it important for business managers to have a basic understanding of the software development

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