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

Deletion anomalies-data redundancy, Deletion Anomalies: Loss of important ...

Deletion Anomalies: Loss of important Information: In some cases, useful information may be lost when a tuple is deleted. For instance, if we delete the tuple corresponding to stu

Oracle, Extend your CREATE TABLE statement from problem 3 with referential ...

Extend your CREATE TABLE statement from problem 3 with referential integrity constraints. Updates and deletes on related rows are restricted. 6. From examination of the sample data

What is a foreign key, What is a foreign key, and what is it used for? ...

What is a foreign key, and what is it used for? A foreign key is used to establish relationships between relations in the relational model. Technically, a foreign key is a colu

horizontal fragmentation, Horizontal Fragmentation- Horizontal fragmentati...

Horizontal Fragmentation- Horizontal fragmentation groups together the tuples in a relation that are collectively used by the main transactions. A horizontal fragment is produced b

Explain briefly concurrent task by taking an example, Explain briefly concu...

Explain briefly concurrent task by taking an example. Concurrent Task- The concurrent occurrence of more than one event is called concurrent task. Operating systems can handl

Which two files are used during operation of the dbms, Which two files are ...

Which two files are used during operation of the DBMS? Data dictionary and transaction log are two files used during operation of the DBMS.

MIS, We face problem of stock Opening balance and closing balance in Minus...

We face problem of stock Opening balance and closing balance in Minus

Relational algebraic operators, Problem Explain at least five relationa...

Problem Explain at least five relational algebraic operators with a suitable example. Note: All the above descriptions should be done by taking at least two examples from ou

Which operator is used to compare a value to a list literals, Which operato...

Which operator is used to compare a value to a list of literals values that have been specified? BETWEEN operator is used to compare a value to a list of literals values that h

What is a heterogeneous distributed database, What is a heterogeneous distr...

What is a heterogeneous distributed database? In a heterogeneous distributed database, dissimilar sites may use different schemas, and dissimilar dbms s/w. The sites may not be

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