Security-data fragmentation, Database Management System

Assignment Help:

Security: Data not needed by local applications is not stored at the site, therefore no unnecessary security violations may exist.

But how can we carry out fragmentation? Fragmentation may be carried out as per the following rules:

a)      Completeness: This rule makes sure that there is no loss of data while fragmentation. If a relation is decomposed into fragments, then every data item must appear in at least single fragment.

b)      Reconstruction: This rule makes sure preservation of functional dependencies. It should be possible to describe a relational operation that will reconstruct the relation from its fragments.

c)       Disjointness: A data item that shows in a fragment should not show in any other fragment. Though, a typical fragmentation known as vertical fragmentation is an exception to this rule. In vertical fragmentation the primary key attributes must be repeated to permit reconstruction of original relation.

This rule makes sure minimization of data redundancy. What are the dissimilar types of fragmentation?

 


Related Discussions:- Security-data fragmentation

What are the types of reference, What are the types of reference?explain it...

What are the types of reference?explain it with suitable examples? Object oriented language given the ability to refer the object attribute of the type can be referred to the s

Illustrate different types of locks in sql server, Illustrate different typ...

Illustrate different types of Locks in SQL Server. There are three kinds of locks in SQL Server i.) Shared locks - These are used for operations which don't allow any update

Sql iis setup and admin - maybe tfs, I want a good Microsoft Admin experien...

I want a good Microsoft Admin experienced in IIS and SQL Server. They require being able to set it up and administer from then onwards. Experience in Team Foundation Server a

Explain the relational completeness, Explain the Relational Completeness ...

Explain the Relational Completeness Codd described the term relational completeness to consider to a language that is complete with respect to first-order predicate calculus ex

Describe interfaces for the dba, Describe Interfaces for the DBA? Inte...

Describe Interfaces for the DBA? Interfaces for the DBA - Most database systems holds privileged commands which could be used only through the DBA's staff. These involves com

What are stand-alone procedures, What are stand-alone procedures? Proce...

What are stand-alone procedures? Procedures that are not part of a package are called as stand-alone because they independently defined. A good example of a stand-alone procedu

Explain the data access protocol, (a) Explain the three types of potentia...

(a) Explain the three types of potential mistake which could occur if concurrency control is not properly enforced in the database system. Support your answer with appropriate ex

Complexity- drawbacks of data distribution, Complexity : A distributed DBMS...

Complexity : A distributed DBMS that is available, reliable, and secure is inherently more difficult than a centralised DBMS. Though, adequate data replication is essential to have

What is a primary key, What is a primary key? Primary key is chosen by ...

What is a primary key? Primary key is chosen by the database designer as the principal means of identifying an entity in the entity set.

How to create values of structured type, How to create values of structured...

How to create values of structured type? Constructor functions are used to make values of structured types. A function with the similar name as a structured type is a construct

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