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

Project, Preliminary entities and attributes of human resourse management d...

Preliminary entities and attributes of human resourse management database management system

What is completeness constraint on generalization, What is completeness con...

What is completeness constraint on generalization? Define the variation between total and partial design constraint. Give an example each.       Ans: Completeness Constraints

Aggregation, Aggregation : One limitation of the E-R diagram is that they d...

Aggregation : One limitation of the E-R diagram is that they do not permit representation of relationships between relationships. In such a case the relationship along with its ent

Wound-wait scheme-deadlock prevention, " Wound-wait" scheme : It is based o...

" Wound-wait" scheme : It is based on a preemptive method. It is based on a simple rule:                   If Ti requests a database resource that is held by Tj

What is theta join explain, What is theta join explain? Theta  Join  -...

What is theta join explain? Theta  Join  - The  theta  join  operation  is  an  extension  to  the  natural-join operation which permits us to merge selection and a Cartesian

Describe in brief about the sequence diagrams, Describe in brief about the ...

Describe in brief about the Sequence Diagrams Sequence diagrams are interaction diagrams which emphasize time ordering of messages. In UML, it is shown as a table which shows

Describe disk manager and their work, Describe disk manager and their work?...

Describe disk manager and their work? Disk Manager: Responsible for fetching data regulated through file Manager from disk storage within Main memory and deciding what data to

Describe the terms ‘database'' and ‘data warehouse'', Problem: ‘Users a...

Problem: ‘Users and Information system specialists need to spend inordinate amounts of time locating and gathering data' (Watson and Hal, 1998) Recent developments in the ar

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