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

In e-r diagram how derived attribute are represented, In E-R Diagram how de...

In E-R Diagram how derived attribute are represented ? In E-R Diagram By Dashed ellipse derived attribute are represented.

Database schemas and dependencies, 1. Staff(staffID, firstName, lastName, a...

1. Staff(staffID, firstName, lastName, availabilityID, experience, phone, mobile, email); 2. Availability(availabilityID, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday,

What is called an evaluation primitive, What is called an evaluation primit...

What is called an evaluation primitive? A relational algebra operation annotated with instructions on how to evaluate is known as an evaluation primitive.

Which of the operations constitute a basic set of operations, Which of the ...

Which of the operations constitute a basic set of operations for manipulating relational data? Relational algebra operations constitute a basic set of operations for manipulati

Explain the 10 reasons to use mysql, Question 1 Explain the 10 reasons to ...

Question 1 Explain the 10 reasons to use MySQL Question 2 Write the SQL statements to demonstrate the following using SELECT command Expression Evaluation ORDER BY

What are stored-procedures, What are stored-procedures? And what are the ad...

What are stored-procedures? And what are the advantages of using them? Stored procedures are database objects that perform a user defined operation. A stored procedure can have

Create a technology web server, Database design Database tables will be...

Database design Database tables will be created for you on the Technology web server. The schema will be as follows. Please note that this is a simplified database structure, d

Need for multiple access paths, Need for Multiple Access Paths In pract...

Need for Multiple Access Paths In practice, most of the online information systems need the support of multi-key files. For example, consider a banking database application hav

What are deadlocks, What are deadlocks?  How can they be avoided?  Ans:...

What are deadlocks?  How can they be avoided?  Ans: Deadlock considers to a particular condition when two or more processes are every waiting for another to release a resource,

List and describe the different types of indexes, Question 1 Indexes are o...

Question 1 Indexes are ocasionally defines on a single field of a file called an indexing field. List and describe the different types of indexes Question 2 Consider a book i

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