What is functional dependency, Database Management System

Assignment Help:

What is Functional Dependency?

A Functional dependency is shown by X Y among two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can form a relation state r of R. The constraint is for any two tuples t1 and t2 in r if t1[X] = t2[X] then they have t1[Y] = t2[Y]. This means the value of X component of a tuple uniquely verifies the value of component Y.

 


Related Discussions:- What is functional dependency

Define transitive dependencies, What do you understand by transitive depend...

What do you understand by transitive dependencies? Define with an example any two problems that can take place in the database if transitive dependencies are available in the datab

Illustrate the term- abstracting out common behaviour, Illustrate the term-...

Illustrate the term- Abstracting Out Common Behaviour Inheritance is not every time recognised during analysis phase of development, thus it is necessary to re-evaluate object

Which components of the schema architecture proposed by ansi, What are thre...

What are three components of the schema architecture proposed by ANSI/SPARC? The three component schema architecture proposed by ANSI/SPARC is as given below: External sche

How can we classify the operations on classes, How can we Classify the oper...

How can we Classify the operations on classes  This step fundamentally means all three models functional, object and dynamic (studied in last section) must be combined so that

Relational DB, Suppose R is a relation with attributes A1, A2,..., An. As a...

Suppose R is a relation with attributes A1, A2,..., An. As a function of n, tell how many superkeys R has, if: 1.1 The only key is A1. 1.2 The only key is A1 and A2. 1.3 The o

In an e-r diagram how attributes are represented, In an E-R diagram how att...

In an E-R diagram how attributes are represented ? In an E-R diagram attributes are represented in a ellipse.

Relational schema, crete a data base relationship model Entity: ...

crete a data base relationship model Entity: Students; Professors; Dormitories buildings; Attributes of students: Name; Address; Dorm;

Advantages of Observation Methods, Advantages of Observation  Methods: ...

Advantages of Observation  Methods: Bailey has pointed  out four  advantages of observation: 1. Superior in Data  Collection  on Non Verbal Behavior: When  a person  a opi

What is interaction diagram, What is Interaction Diagram An interactio...

What is Interaction Diagram An interaction diagram shows an interaction, comprises of a set of objects and their relationships including the messages that may be dispatched be

For known, What are the function of DBA?

What are the function of DBA?

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