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

Oracle/sql, can you create a database for me in oracle/sql

can you create a database for me in oracle/sql

Draw an er diagram for organization of a student database, Draw an ER diagr...

Draw an ER diagram that shows the organization of a simple student database. The database captures the information about letter grades obtained by university students who enrolled

Explain dml with some examples, Explain DML with some examples? DML - D...

Explain DML with some examples? DML - Data Manipulation Language: statements used for managing data within schema objects. Some examples: • SELECT - retrieve data from the a da

Discuss the types of integrity constraints with example, Discuss the types ...

Discuss the types of integrity constraints in which must be checked for the update operations - Insert and Delete. Give examples. Insert operation can violet any of the subse

Storage of database on hard disks, Storage Of Database On Hard Disks At...

Storage Of Database On Hard Disks At this point, it is worthwhile to note the difference among the terms file Organisation and the access method. A file organisation shows to t

What is ocr, What is OCR? OCR (Optical Character Recognition) is a tech...

What is OCR? OCR (Optical Character Recognition) is a technology that enables you to change different types of machine-readable documents, like scanned paper documents, PDF fil

Create a classification model, Use again the GE Flight Quest Data and build...

Use again the GE Flight Quest Data and build on the work done for homework 1 and 2. The goal is to create a classification model which classifies flights into "on-time" (you can de

List the requirements needed to design a trigger, List the requirements nee...

List the requirements needed to design a trigger. The requirements are:- Specifying when a trigger is to be implemented. State the actions to be taken when the trigger im

ER Diagram, Soccer player ER Diagram to Relational database schema

Soccer player ER Diagram to Relational database schema

Eliminate columns not dependent on key, Eliminate Columns Not Dependent On ...

Eliminate Columns Not Dependent On Key The Employee Relation satisfies - First normal form - As it has no repeating groups. Second normal form - As it do not have multi-a

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