Fully-functional dependency in DBMS

DBMSDatabaseMySQL

An attribute is fully functional dependent on another attribute, if it is Functionally Dependent on that attribute and not on any of its proper subset.

For example, an attribute Q is fully functional dependent on another attribute P, if it is Functionally Dependent on P and not on any of the proper subset of P.

Let us see an example −

<ProjectCost>

ProjectID
ProjectCost
001
1000
001
5000

<EmployeeProject>

EmpID
ProjectID
Days
E099
001
320
E056
002
190

The above relations states that −

Days are the number of days spent on the project.

EmpID, ProjectID, ProjectCost -> Days


However, it is not fully functional dependent.

Whereas the subset {EmpID, ProjectID} can easily determine the {Days} spent on the project by the employee.

This summarizes and gives our fully functional dependency −

{EmpID, ProjectID}  -> (Days)
raja
Published on 03-Jul-2018 16:08:39
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