Define the canonical cover, Database Management System

Assignment Help:

Define the Canonical cover

Ans: A canonical cover Fc for F is a set of dependencies like F logically implies all dependencies in Fc, and Fc logically entails all dependencies in F. Fc must have the subsequent properties:

  • No functional dependency in Fc consists of extraneous attribute
  • Every left side of a functional dependency in Fc is unique. Which is, there are no two dependencies α1→ β1 and α2→β2 in Fc such that α1 = α2.

 Fc is minimal in certain sense - it does not consist of extraneous attributes, and it combines functional dependencies with similar left side. It is cheaper to test Fc than it is to test F itself.


Related Discussions:- Define the canonical cover

Search the name department number and salary of employees , Example : Searc...

Example : Search the name, department number and salary of employees drawing minimum salary in that department. SELECT ENAME, SAL, DEPTNO  FROM EMP WHERE SAL IN (SELECT MI

Define deadlock avoidance, Define Deadlock avoidance These protocols a...

Define Deadlock avoidance These protocols as well ensure that the system will never enter a deadlock state although the way it is done is different from deadlock prevention. I

Modify - referential integrity, Update or Modify operation alters the exist...

Update or Modify operation alters the existing values. If these operations alter the value that is the foreign key also, the only check need is the similar as that of the Insert op

Database project, A database to track your progress in your college program...

A database to track your progress in your college program will track your progress towards graduation! A database that has information containing the classes that you have taken, c

Data base design, how to design a bakery business in data base

how to design a bakery business in data base

Can you delete data element, Can we delete data element, which is being use...

Can we delete data element, which is being used by table fields. No we cant delete data element.

The conceptual level or global level in dbms, The Conceptual Level or Globa...

The Conceptual Level or Global level The conceptual level presents a logical view of the complete database as a unified whole. It permits the user to bring all the data in th

What are the authentication modes in sql server, What are the authenticatio...

What are the authentication modes in SQL Server? How can it be changed? Windows mode and Mixed Mode - SQL and Windows. To alter authentication mode in SQL Server click Start, P

What is dbms and what are functions of dbms, What is DBMS and what are func...

What is DBMS and what are functions of DBMS? DBMS consist of collection of integrated data and set of program to admission those data. The functions performed by a typical

The third normal form (3nf), The Third Normal Form (3NF) Even though, t...

The Third Normal Form (3NF) Even though, transforming a relation that is not in 2NF into a number of relations that are in 2NF take out many of the anomalies, it does not neces

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