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

Distributed query and transaction processing, Distributed query and transac...

Distributed query and transaction processing a.  Construct a query around any one of the functional divisions you made in 4a such that if executed in the distributed design of 4

Illustrate package classes and associations into models, Package classes an...

Package classes and associations into models  Programs are made of separate physical units which could be edited, imported, complied or otherwise manipulated. The careful part

Column constraints-on delete cascade, CREATE TABLE prodtrans ( pno ...

CREATE TABLE prodtrans ( pno number (4) ptype char (1) CHECK (ptype in ('I','R','S')), qty number (5) FOREIGN KEY pno REFERENCES product (pno) ON DELETE CASCADE);

Concept of foreign key, Fundamentals of Database Management 1. Explai...

Fundamentals of Database Management 1. Explain the concept of Foreign Key. How a foreign key differs from a Primary Key? Can the Foreign Key accept nulls? 2. With a necess

What are ways of finding out derived attributes, What are ways of finding o...

What are ways of finding out either an update is required or not for derived attributes? The ways to find out an update is required or, not are as: Explicit update

DW Job Scheduling, Define a job scheduling strategy that will meet business...

Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pictori

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

Give the reasons for allowing concurrency, Give the reasons for allowing co...

Give the reasons for allowing concurrency? The reasons for allowing concurrency is if the transactions run serially, a short transaction might have to wait for a preceding long

Strict 2pl-two phase locking (2pl), Strict 2PL :Though, this basic 2PL suff...

Strict 2PL :Though, this basic 2PL suffers from the trouble that it can result into loss of isolation / atomic property of transaction as theoretically speaking once a lock is rele

Explain the role of a database administrator, Explain the Role of a databas...

Explain the Role of a database administrator a. Defining the Schema   The DBA describes the schema which consists of the structure of the data in the application. The DBA

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