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

Ideal data dictionary, An ideal data dictionary should have everything a DB...

An ideal data dictionary should have everything a DBA wants to know about the database. 1 Conceptual, External, and internal database descriptions. 2. Descriptions of attr

Write a query to find name from the relational algebra, Consider the relati...

Consider the relations City (city_name, state) Hotel (name, address) City_hotel (hotel_name, city_name, owner) Answer the following queries in relational algebra (i) Find

Information infrasture, what benefit can a company gain by managing its own...

what benefit can a company gain by managing its own infrasture and services

What are ways of finding out derived attributes, What are ways of finding o...

What are ways of finding out either an update is required or not for derived attributes? The ways to find out an update is required or, not are as: Explicit update

Shadow paging, Describe the shadow paging technique.

Describe the shadow paging technique.

Define single valued and multivalued attributes, Define single valued and m...

Define single valued and multivalued attributes. Single valued attributes: attributes with a single value for a particular entity are known as single valued attributes. Mult

Foreign keys , Foreign Keys and NULL Let us take the relation: ...

Foreign Keys and NULL Let us take the relation: DEPT DEPT ID DNAME BUDGET D1 M

Design and build a data mart, You are required to design and build a data m...

You are required to design and build a data mart/data warehouse using Oracle. A national bank allocates funding every year for its local branches to provide temporary staff cove

Describe participation constraints, Describe Participation Constraints? ...

Describe Participation Constraints? Participation Constraints - The participation constraint exacts whether the existence of an entity depends on its being related to another

Ordering of tuples, In a relation, tuples are not inserted in any definite ...

In a relation, tuples are not inserted in any definite order. Ordering of tuples is not defined as a part of a relation definition. Though, records may be structured later accordin

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages