Define the canonical cover, Database Management System

Assignment Help:

Define the Canonical cover

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

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

F_c 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 F_c than it is to test F itself.

Related Discussions:- Define the canonical cover

To eliminate duplicate rows-data manipulation language, To eliminate duplic...

To eliminate duplicate rows (distinct operator) Example: SELECT DISTINCT DEPTNO FROM EMP;

Normalization e, explain normalization,and give the examples 1NF,2NF,3NF,BC...

explain normalization,and give the examples 1NF,2NF,3NF,BCNF.AND FUNCTIONAL DEPANDENACY AND DECOMPOSITION TECHNIQUES.

What is an index as defined in oracle, Normal 0 false false ...

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

Example for while until, Assume you are given a uniprocessor system with on...

Assume you are given a uniprocessor system with one gigabyte of memory and a 300 gigabyte disk. The OS on the machine has a demand paged virtual memory system with a local page rep

List out user authorization to modify the database schema, List out various...

List out various user authorization to modify the database schema. a) Index authorization b) Resource authorization c) Alteration authorization d) Drop authorizat

What is waterfall model, Waterfall model is the linear model. The process i...

Waterfall model is the linear model. The process is completed by step by step. We couldn't stop in between of the process. Prototype model: after get the model by low cost budget o

Illustrate the state model for the atm class, Illustrate the State model fo...

Illustrate the State model for the ATM class let us take state model for the ATM class given below in Figure showing state model of the ATM class and the pseudo code derived fr

How to rearrange the execution order for efficiency, Rearrange the Executio...

Rearrange the Execution Order for Efficiency Rearranging execution order for efficiency means executing such job that requires less execution time. By rearranging the object

Define dbms, Define DBMS? DBMS: database management system (DBMS) is co...

Define DBMS? DBMS: database management system (DBMS) is computer software designed for the reason of supervision databases based on a variety of data models.

What is index, What is Index? An index is a physical structure having p...

What is Index? An index is a physical structure having pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It is possibl

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages