What is functional dependency, Database Management System

 

A Functional dependency is described by X Y between two groups of attributes Y and X that are subsets of R specifies a constraint on the possible tuple that can make a relation state r of R. The constraint is for any two tuples t2 and t1 in r if t1[X] = t2[X] then they have t1[Y] = t2[Y]. This seems the value of X element of a tuple uniquely calculates the value of element Y.

 

 

1458_Functional Dependency.png

Posted Date: 7/30/2012 2:07:19 AM | Location : United States







Related Discussions:- What is functional dependency, Assignment Help, Ask Question on What is functional dependency, Get Answer, Expert's Help, What is functional dependency Discussions

Write discussion on What is functional dependency
Your posts are moderated
Related Questions
Project Description: I want to build a card playing Website. The user should be able to 1. Login. 2. Have profile access. 3. Put money into the site. 4. Selects t

Differance between procedural and non procedural DML? Procedural and non procedural DML Procedural DML exactly what data is require and how to obtain those data. Non procedural

Determine the method of Choosing Algorithms In general, most of operations are easy and have a satisfactory algorithm since description of what is to be done also shows how i

Explain cursors in SQL? Cursors in SQL - An object used to store the output of a query for row-through-row processing through the application programs. Cursors are constructs

How does Oracle act as ODBC and give examples of front end uses with ODBC? ODBC achieve portability at the level of the executable by introducing an extra level of indirection.

While using extract datasets it is required to have a special workarea for interface False.  It is not required to have a special workarea for interface

Define deadlock avoidance. An alternative method for avoiding deadlocks is to needs additional information about how resources are to be requested. Each request requires the s

what are information system hirarchy?

Question 1 Describe the following- Clustering Indexing Question 2 Explain the following with suitable real time examples- Implementation of Integrity rules

Explain data independence ? Data independence is the capacity to modify the schema at one stage of a database system without having to change the schema at the further level.