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

Concurrent transactions-backup and recovery, Representing complex relations...

Representing complex relationship among data A database may contain varieties of data interrelated to each other in numerous ways. A DBMS must have the capability to represent

Develop a database design , A practice called Perfect Pets provides private...

A practice called Perfect Pets provides private health care for domestic pets throughout America. This service is provided through various clinics located in the main cities of Ame

Dataset, The dataset " CFOLYMPICS.XLS " contains the observations used in t...

The dataset " CFOLYMPICS.XLS " contains the observations used in the above article. The definitions of the variables are also included in this spreadsheet. However, for the purpo

Participation constraints, explain participation constraints with examples

explain participation constraints with examples

Statistical analysis of data, An important first step to the statistical an...

An important first step to the statistical analysis of data is to "get to know your data". The following tasks should contribute to this. (a) To the right of the dataset cons

Using column aliases-data manipulation language, Using Column aliases E...

Using Column aliases Example: To print column names as NAME and ANNUAL SALARY SELECT ENAME "NAME", SAL*12 "ANNUAL SALARY" FROM EMP;

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

Triggers and Stored Procedures, 10A.53 Code an Oracle Database trigger to e...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the delet

Using relational algebra which query finds customers, Using Relational Alge...

Using Relational Algebra which query finds customers, who have a balance of over 1000 ? Using Relational Algebra Π Customer_name( σ balance >1000(Deposit)) is query to find cu

Database project- inventory database for a hardware store, Normal 0 ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages