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

Sequential file organisation, Sequential File Organisation The most nec...

Sequential File Organisation The most necessary way to organise the collection of records in a file is to use sequential Organisation. Records of the file are stored in series

Give the levels of data abstraction, Give the levels of data abstraction? ...

Give the levels of data abstraction? There are three levels of Data Abstraction a) Physical level b) logical level c) view level

Function module, When a function module is activated syntax checking is per...

When a function module is activated syntax checking is performed automatically. YEs, a function module is activated syntax checking.

Student management system, projects?

projects?

Database tables design and test queries, Load sample data into the database...

Load sample data into the database tables design and test queries to return the following information • All rows and columns for employees • All rows and columns for customers •

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

Economics, Economics: It is now usually accepted that it costs less to make...

Economics: It is now usually accepted that it costs less to make a system of smaller computers with the equivalent power of a one large computer. It is more cost-effective to get s

Concurrent transactions-backup and recovery, Representing complex relations...

Representing complex relationship among data A database may contain varieties of data interrelated to each other in numerous ways. A DBMS must have the capability to represent

Type of views-data control, Type of views : Simple views and Difficult ...

Type of views : Simple views and Difficult Views Feature Simple Views Complex Views Number of tables One

In which format database schema is written, In which format database schema...

In which format database schema is written ? Data base schema is written in the DDL format.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages