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

Approach to implement traffic data management, There are many simple and co...

There are many simple and complex approaches to implement. These reports are based on some views or certain query. The following number of reports can be built. 1. The averag

Explain about sql server 2000, What is the difference between SQL Server 2...

What is the difference between SQL Server 2000 complete and differential backups? A complete backup makes a copy of the whole database. A differential backup creates a copy of

Improved reliability, Improved Reliability: In a centralised DBMS, a server...

Improved Reliability: In a centralised DBMS, a server failure stops the operations of the DBMS. Though, a failure at single site of a DDBMS, or a failure of a communication link cr

What is distributed system, What is Distributed system ? Distributed S...

What is Distributed system ? Distributed System - A distributed system consists of a number of processing parts in which are interconnected through a computer network and in

Explain the rules for creating a labelled precedence graph, Explain the rul...

Explain the rules for creating a labelled precedence graph for testing view serializability.            Ans: A schedule S is view serializable if it is view equivalent to a ser

What is trigger, What is trigger?  Triggers are statements that are exe...

What is trigger?  Triggers are statements that are executed automatically by the system as the side effect of a modification to the database.

Design a database table, A database named yourusernameFMA has been set up f...

A database named yourusernameFMA has been set up for you to use for this assignment.  For the FMA you must create the required tables and run the queries using this database.  If y

Online examination system project, entity relationship diagram for online e...

entity relationship diagram for online examination system

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