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

What are the different approaches for database design, What are the differe...

What are the different approaches for database design? There are two basic approaches for database design which are as follows: Attribute driven: It compiles a list of att

What is persistency, What is persistency? Persistency ensures which dat...

What is persistency? Persistency ensures which data is stored and that after the object is no longer available (program stops running) the data will be available to other users

Write a short note on oracle instance, Write a short note on oracle Instanc...

Write a short note on oracle Instance? Oracle Instances: An instance is the (executed) Oracle software and the memory they use. It is the instance which manipulates the data s

What is a primary key, What is a primary key? Primary key is chosen by ...

What is a primary key? Primary key is chosen by the database designer as the principal means of identifying an entity in the entity set.

Transaction states, The following variant of the primary copy asynchronous-...

The following variant of the primary copy asynchronous-update replication protocol has been proposed for totally replicated systems. (a)  A transaction executing at site A updat

Why like predicate used for, Why Like predicate used for? LIKE predicat...

Why Like predicate used for? LIKE predicate: The LIKE predicate searches for strings in which have a certain pattern.

What are the two statements regarding transaction, What are the two stateme...

What are the two statements regarding transaction? The two statements regarding transaction of the form are:- A)     Begin transaction B)      End transaction

Define a view and a trigger, Define a view and a trigger. Construct a view ...

Define a view and a trigger. Construct a view for the above relations that have the information about suppliers and the elements they supply. The view holds the S#, SNAME, P# , PNA

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