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

Explain the togaf framework for enterprise architectures, Question: (a)...

Question: (a) With the help of a diagram, explain the TOGAF framework for enterprise architectures. (b) Where would you position enterprise architectures in an enterpri

Describe participation constraints, Describe Participation Constraints? ...

Describe Participation Constraints? Participation Constraints - The participation constraint exacts whether the existence of an entity depends on its being related to another

Differentiate between b-tree and b+ tree, Differentiate between B-tree and ...

Differentiate between B-tree and B + tree    Ans:  A B-tree (or Balanced Tree) is a search tree along with additional constraints that makes sure that the tree is all the time

What is the function of a domain, What is the function of a Domain? A d...

What is the function of a Domain? A domain defines the technical settings of a table field. A domain describes a value range, which sets the permissible data values for the

Shadow paging, Describe the shadow paging technique.

Describe the shadow paging technique.

horizontal fragmentation, Horizontal Fragmentation- Horizontal fragmentati...

Horizontal Fragmentation- Horizontal fragmentation groups together the tuples in a relation that are collectively used by the main transactions. A horizontal fragment is produced b

Explain instance and schemas, Explain Instance and schemas? Instances ...

Explain Instance and schemas? Instances and schemas: Databases changes over time as the information is deleted and inserted. The collection of information stored in database

List the drawbacks of relational database system, List the drawbacks of rel...

List the drawbacks of relational database system A) Repetition of data B) Inability to s certain information.

Drop table command, DROP TABLE Command: When an existing object is not ...

DROP TABLE Command: When an existing object is not needed for further use, it is always better to eliminate it from the database. To remove the existing object from the databas

Fundamental operations that are regular to mysql programs, What are the thr...

What are the three fundamental operations that are regular to MySQL Programs? a) Establishing a connection to the MySQL server b) Choosing a database. c) Disconnecting fr

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