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

Define upgrade and downgrade, Define upgrade and downgrade? It gives a ...

Define upgrade and downgrade? It gives a mechanism for conversion from shared lock to exclusive lock is called as upgrade. It gives a mechanism for conversion from exclusive

Discuss the three level architecture of dbms, PRINCIPLES OF DATABASE 1....

PRINCIPLES OF DATABASE 1. State the following terms: a) Database b) Database Management System c) Entity d) Attribute e) Relationship 2. Discuss the Three Level Architecture

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

Explain the concepts of relational data model, Explain the concepts of rela...

Explain the concepts of relational data model? Relational Data Model - The relational model was first introduced through Prof. E.F. Codd of the IBM Research in the year 1970

What are the types of reference, What are the types of reference?explain it...

What are the types of reference?explain it with suitable examples? Object oriented language given the ability to refer the object attribute of the type can be referred to the s

List the sql domain types, List the SQL domain Types? SQL supports the ...

List the SQL domain Types? SQL supports the following domain types. 1) Char(n) 2) varchar(n) 3) int 4) numeric(p,d) 5) float(n) 6) date.

Explain cascade and restrict clauses of drop schema command, Explain severa...

Explain several types of constraints that can be specified using CREATE TABLE command. Explain CASCADE and RESTRICT clauses of DROP SCHEMA command? Constraint Description PRIM

The locking protocol, The Locking Protocol: To manage concurrency related ...

The Locking Protocol: To manage concurrency related problems we use locking. A lock is mainly a variable that is associated with a data item in the database. A lock can be located

Develop a web site to present decision tree structure, I am going to develo...

I am going to develop a web site to present decision tree structure. For this, I want a web application with AJAX technology to connect the database and prepare the decision tree's

DBMS, to develop elrctronic database from manual forms

to develop elrctronic database from manual forms

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