Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Dependency Preservation
It is obvious that the decomposition must be lossless so that we do not lose any information from the relation that is decomposed. Dependency preservation is another main requirement since a dependency is a constraint on the database. If each attributes appearing on the left and the right side of a dependency appear in the similar relation, then a dependency is considered to be preserved. Therefore, dependency preservation can be checked simply. Dependency preservation is important, because as stated previously, dependency is a constraint on a relation. Therefore, if a constraint is split over more than one relation (dependency is not preserved), the constraint would be complex to meet. We will not talk about this in more detail in this unit. You may refer to the more readings for more details. Though, let us state one basic point:
"A decomposition into 3NF is lossless and dependency preserving whereas a decomposition into BCNF is lossless but may or may not be dependency preserving."
What are the benefits of document scanning? Document scanning, in addition to being cost-efficient, also enhances productivity. This service enhances security as you set the pa
Structure of Client Server Systems: In client/server architecture, clients show users who require services while servers give services. Both client and server are a combination of
A database is a set of data. But, is the data kept in a database trustworthy? To answer that query we must first answer the question. What is integrity? Integrity simply means t
What is abstraction? Abstraction in the object orientation is a idea that provide opportunity to express necessary properties of object without providing much details of the im
What Is Recovery? During the life of a transaction, i.e., a after the start of a transaction but before the transaction commits, various changes may be made in a database state
case study
What is a recovery scheme? An integral part of a database system is a recovery scheme that can restore the database to the reliable state that existed before the failure.
Differentiate between Key and superkey? Key and superkey - A key a single attribute or a combination of two or more attributes of an entity set in which is used to identify o
When It is better to use files than a DBMS? It is better to use files than a DBMS when Multiple users wish to access the data.
Explain the Cartesian product: The Cartesian product operation does not need relations to union-compatible. The meaning of this is that the involved relations may have dissim
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd