Explain weak and strong entity type, Database Management System

Assignment Help:

Explain weak and strong entity type ?

Weak and Strong entity type: An entity set which does not have a primary key is referred to as a weak entity set. The existence of a weak entity set depends on the existence of a strong entity set; it must associate to the strong set via a on-to-many relationship set. A discriminator of a weak entity set is the set of attributes that distinguishes between all the entities of a weak entity set. The primary key of a weak entity set is formed by the primary key of the strong entity set on that the weak entity set is existence depends, plus the weak entity set's discriminator.


Related Discussions:- Explain weak and strong entity type

Insertion anomaly-data redundancy, Insertion Anomaly: Inability to show ce...

Insertion Anomaly: Inability to show certain information-The primary key of the over relation be (enrolment number, Cno). Any new tuple to be inserted in the relation should have

Normalization-e-r mapping , Normalize the following table upto and includin...

Normalize the following table upto and including the 3NF. Submit a 1 page printout of only the final set of normalized tables in Data Architect. Just use Data Architect to do the t

Explain p command in the respect of qbe, Explain P command in the respect o...

Explain P command in the respect of QBE? P: It is the command in which is used to print (logically display) the value of the attribute in whose cell it is writ

Basics of relational models, In the first unit of this block, you have been...

In the first unit of this block, you have been given with the details of the Database Management System, its structure, advantages etc. This unit is an attempt to give you informat

What is a view, What is a view?  Make a view of EMP table named DEPT 20, to...

What is a view?  Make a view of EMP table named DEPT 20, to display the employees in department 20 and their annual salary.  Ans:  View is a virtual table that does not consist

Name the three major database in oracle, Name the three major set of files ...

Name the three major set of files on disk that compose a database in Oracle. There are three main sets of files on disk that compose a database. All the files are binary. These

The need for three level architecture, The need for three level architectur...

The need for three level architecture The aim of the three level architecture is to divide each user's view of the database from the way the database is physically shown.

Prove that a relation which is 4nf must be bcnf, Prove that a relation whic...

Prove that a relation which is 4NF must be BCNF.   Ans Let R be in 4NF.  Suppose it is not in BCNF.  Hence, there exists an FD X→Y in R such that x is not a super key. Although

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