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 instance and schema, Define instance and schema? Instance: Colle...

Define instance and schema? Instance: Collection of data stored in the data base at a certain moment is Schema: The overall design of the data base is known as the data base

Write query to insert data in student table, Consider student (std_id, std_...

Consider student (std_id, std_name, date_of_birth, phone, dept_name). Put the data for a student with student id200, name arun, birth date 1 February, 1985, phone number (01110 328

3-schema architecture, Gyan Gurukul is a software company that provides sof...

Gyan Gurukul is a software company that provides software related solution. Ashutosh Dubey who is the director of Gyan Gurukul want a three-level schema architecture for the Gyan G

Write short notes on relational constraints, Write short notes on relationa...

Write short notes on relational constraints? Relational Constraints are: 1. NOT NULL 2. Unique 3. Primary key 4. Foreign key 5. Table check

I need erp system, I need ERP system We are selling automotive spare par...

I need ERP system We are selling automotive spare parts on the internet and we require ERP software, which would sync with our e-shop. Our e-shop doesn't use any e-commerce plat

Domains, A domain is a set of permissible values that can be given to an at...

A domain is a set of permissible values that can be given to an attribute. So each attribute in a table has a definite domain. Values to these attributes cannot be assigned outside

What is omr, What is OMR? OMR (Optical Mark Recognition) is the transla...

What is OMR? OMR (Optical Mark Recognition) is the translation of marks - or the absence of marks - but not the shape of the mark on forms that have small circles ("also called

Managing database, 10A.53 Code an Oracle Database trigger to enforce the ...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the

Write the sql code, Express the following queries in SQL: (a) Write the...

Express the following queries in SQL: (a) Write the SQL code that will create ALL the four tables given in the appendix. Your answer should not contain the primary key and

Data base design for a museum information system, In this practical assignm...

In this practical assignment, we will run through a complete database application development cycle, starting with the schema design, from an initial data import to database applic

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