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

Example-revoke all on emp from mca12, Example:  //REVOKE ALL ON EMP FROM MC...

Example:  //REVOKE ALL ON EMP FROM MCA12;                              (All permissions will be cancelled) You can also cancel only some of the permissions. Drop: A user-

Max. no. of structures in a table or structure, What is the max. no. Of str...

What is the max. no. Of structures that can be included in a table or structure. Nine.

Define first normal form and second normal form, First Normal Form and seco...

First Normal Form and second normal form First Normal Form (1NF) A relation is said to be in 1NF if it having no non-atomic values and each row can give a unique combinat

When is update_statistics command used, When is UPDATE_STATISTICS command u...

When is UPDATE_STATISTICS command used? - When processing of large data is done, this command is used. - Whenever large number of modification, deletions or copy takes place

What are the failures of controlling events between objects, What are the f...

What are the failures of Controlling Events Between Objects  Failure Unintentional termination of system. Several possible causes: failure of system hardware, o

Define cardinality and participation constraints, Define cardinality and pa...

Define cardinality and participation constraints on a relationship type, completeness constraint on generalization.        Ans: Cardinality defines the number of entities to wh

Determine the types of methods for retrieving rows in python, Describe the ...

Describe the two types of methods for retrieving rows in Python? Fetchone()- Returns the next row as a sequence Fetch all()- Returns the entire result set like a strin

Describe the term- state diagram, Describe the term- State Diagram Sta...

Describe the term- State Diagram State Diagram: An object could receive a sequence of the input instructions. The state of the object can differ depending upon sequence of in

Define the traditional system analysis and design, Define the Traditional S...

Define the Traditional System Analysis and Design Traditional System Analysis and Design (SAD) have three basic life cycle models. A typical software lifecycle consists of the

Functional Dependencies, What exactly is the concept of Functional Dependen...

What exactly is the concept of Functional Dependencies? And how do we associate this concept with the logic of Super-keys, Candidate Keys, etc? Given Relation R(A,B,C,D,E) with de

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