Fds in relationships and teaches relationship, Database Management System

Assignment Help:

FDs in Relationships:

 Enrols Relationship: None as it is many to many

Teaches Relationship: Course code → Instructor

Instructor → Course code

The next question is:  How do we recognize the functional dependence in a database model?

Functional dependencies occur from the nature of the actual world that the database models. Often A and B are facts about an entity where A may be some identifier for the entity and B some characteristic. Functional dependencies cannot be automatically determined by studying one or more cases of a database. They can be determined only by a careful study of the actual world and a clear understanding of what every attribute means.

 There are no thumb rules for determining FDs.

Functional dependence is an vital concept and a large body of formal theory has been developed about it.

 


Related Discussions:- Fds in relationships and teaches relationship

Physical database design issues, Physical Database Design Issues The da...

Physical Database Design Issues The database design includes the process of logical design with the use of E-R diagram, normalisation, etc., followed by the physical design.

What is known as a search key, What is known as a search key? An attrib...

What is known as a search key? An attribute or set of attributes used to look up records in a file is known as a search key.

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

Normalization, Consider a bank that has a collection of sites, each running...

Consider a bank that has a collection of sites, each running a database system. Suppose the only way the databases interact is by electronic transfer of money between one another,

Draw entity relationship diagram, Draw entity relationship diagram for the ...

Draw entity relationship diagram for the following scenario. A university has many departments whereas each department belongs to that particular uni. That uni has also many bui

Explain the shadow paging recovery technique, Explain the shadow paging rec...

Explain the shadow paging recovery technique.  Ans: Shadow paging is a method used to acquire atomic and durable transactions, and provides the capability to manipulate pages i

Search the salary of employees who are not ‘analyst’ , Example- Search the ...

Example- Search the salary of employees who are not 'ANALYST' but get a salary below than or equal to any people employed as 'ANALYST'. SELECT EMPNO, ENAME, JOB, SAL FROMEMP

What is an index as defined in oracle, Normal 0 false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain the object-oriented decomposition, Explain the Object-oriented deco...

Explain the Object-oriented decomposition Object-oriented decomposition targets at identifying individual sovereign objects that encapsulate both a state and certain behavio

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