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

Purchase orber , Run the following queries. For each query show 1) What yo...

Run the following queries. For each query show 1) What you expect the output to be based upon the data 2) the SQL code and 3) the output running the query in Oracle. 1. Show all c

Create a view containing name and number of department, Create a view emp_d...

Create a view emp_dep containing e_name and number of dependents from the tables employee and dependent of (i) CREATE VIEW emp_dept AS SELECT ename, COUNT(*) FROM employee, dep

Assignment, What are the typical phases of query processing

What are the typical phases of query processing

Describe all integrity constraints which are violated, Consider the two rel...

Consider the two relations given below Given that A is the primary key of R, D is the primary key of S and there is a referential integrity among S.A and R.A, discuss all

Data dictionary, The database is to record information about artists for a ...

The database is to record information about artists for a (music) production company. An artist is the name of a singer or band; the name of the artist, the year the artist started

Employee 7566 salary is extra than salary of employee 7788, Normal 0 ...

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

Database, real life situations where database management system are most su...

real life situations where database management system are most suitable

What do you mean through integrity constraints, What do you mean through in...

What do you mean through integrity constraints? Integrity Constraints -An integrity constraint is a condition specified on a database schema and restricts the data in which

Table handling, Table Handling In RDBMS more than one table can be tac...

Table Handling In RDBMS more than one table can be tackled at a time by using join operation. Join operation is a relational operation that causes 2 tables with a common domai

Relational DB, Suppose R is a relation with attributes A1, A2,..., An. As a...

Suppose R is a relation with attributes A1, A2,..., An. As a function of n, tell how many superkeys R has, if: 1.1 The only key is A1. 1.2 The only key is A1 and A2. 1.3 The o

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages