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

Develop a java application, 1 - Serial RS232 comm port comunication 2 - ...

1 - Serial RS232 comm port comunication 2 - NanoHTTPD serving a few processed pages 3 - System tray application to indicate status and access configuration forms 4 - SQLit

Explain the aggregation implies concurrency, Explain the Aggregation implie...

Explain the Aggregation implies concurrency Concurrency actually is: This in objects can be identified by the way they change state. Present objects can change state independen

Entity Relationship for music band managem modeliing, i am required to come...

i am required to come up with entities relationships, optionality and cardinality from a scenario. there is a night club and bookings for a musician band

What are the benefits of decomposing a system, What are the benefits of dec...

What are the benefits of decomposing a system? The benefits of decomposing a system into subsystems are that after decomposition, each individual component become smaller and e

Set concept is used in which type of modelling, SET concept is used in whic...

SET concept is used in which type of modelling? SET concept is used in Network Model.

What is null described testing for null in sql?, What is NULL? Give an exa...

What is NULL? Give an example to described testing for NULL in SQL? The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a re

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.

What are the drawbacks of shadow-paging technique, What are the drawbacks o...

What are the drawbacks of shadow-paging technique? The drawbacks of shadow paging is:- a) Commit Overhead b) Data fragmentation c)  Garbage collection

Need for multiple access paths, Need for Multiple Access Paths In pract...

Need for Multiple Access Paths In practice, most of the online information systems need the support of multi-key files. For example, consider a banking database application hav

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