Security-data fragmentation, Database Management System

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?

 

Posted Date: 3/13/2013 8:36:06 AM | Location : United States







Related Discussions:- Security-data fragmentation, Assignment Help, Ask Question on Security-data fragmentation, Get Answer, Expert's Help, Security-data fragmentation Discussions

Write discussion on Security-data fragmentation
Your posts are moderated
Related Questions
Do you have experts of the dbms

List the set operations of SQL? 1) Union 2) Intersect operation 3) The except operation

Illustrate the view of software architecture A model is a semantically closed abstraction of system composes of elements. It can be visualized using any of the following five v

Create an index for the table Client, field CLIENT_NO of Q ? Command:   CREATE INDEX client_client_no ON client(client_no);

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

Funky Festivals Specification Funky Festivals organise music festivals which take place at various venues throughout the UK.  A venue needs to be booked before a Festival can t

How is Oracle used in PL/SQL? Define the features of process and how they are defined? PL/SQL - PL/SQL is Oracle's procedural language (PL) superset of the Structured

The traffic data mgmt. systems infrastructure plan describes the software, hardware, data network, and other elements that will support the TDMS. The infrastructure plan is based o

Explain how the associations are implemented as classes. A general approach in this case is to transform an association class into a simple class linked to two original classes

Relations create the database. They must satisfy various properties, like no duplicate tuples, no ordering of tuples, and atomic attributes, etc. Relations that satisfy these basic