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

What is an entity relationship model, What is an entity relationship model?...

What is an entity relationship model? The entity relationship model is a set of basic objects known as entities and relationship between those objects. An entity is a thing or

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

Explain the need of parallel database, Probelm: a) In the context of OO...

Probelm: a) In the context of OODBMS, define the following terms with appropriate examples. (i) Object class. (ii) Abstract class. (iii) Aggregation. (iv)

Write a short note on temporary tables, Write A short note on temporary tab...

Write A short note on temporary tables? Temporary Tables - Temporary tables exists solely for a particular session, or whose data persists for the duration of the transaction

Insulation between conceptual and physical structures, Insulation between c...

Insulation between conceptual and physical structures It can be defined as: 1. The Database Administrator should be capable to vary the storage structures without affectin

Report writing help on database mgmt, Report writing help on database mgmt ...

Report writing help on database mgmt Project Description: Use of Harvard referencing, critical analysis is required. Skills required: Academic Writing, Technical Writin

Explain what is aggregation, Explain what is Aggregation? Aggregation:...

Explain what is Aggregation? Aggregation: Aggregation is an significant concept in database design whereas composite objects could be modelled during the design of database a

Functional dependencies, CAR SALE (Car_id, Option_type, Option_listprice, S...

CAR SALE (Car_id, Option_type, Option_listprice, Sale_date, Option_discountedprice) This relation refers to options installed in cars (e.g., cruise control) that were sold at a de

Determine the persistent object, Determine the Persistent object Persis...

Determine the Persistent object Persistent object can be stored in one of the following: Files Cheap, permanent, simple storage Low level (Write, Read) Ap

Functional dependencies, 1. Staff (staffID --> availabilityID) 2. Servic...

1. Staff (staffID --> availabilityID) 2. Services (servicesID --> itemBasedID --> timedBasedID) 3. TimedBased (timedbasedID--> priceid) 4. Clients (clientId, serviceId-->

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