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

Derived horizontal fragmentation, Derived horizontal fragmentation: Some ap...

Derived horizontal fragmentation: Some applications may include a join of two or more relations. If the relations are stored at dissimilar locations, there may be a major overhead

Use the relational algebra to formulate query, Consider the following datab...

Consider the following database schema: STAFF(StaffNo, fName, lName, Position, sex, dob, branchNo) BRANCH(BranchNo, Street, City) Assume the following for the above database

Describe about use case and external case in dfd, Describe about Use Case a...

Describe about Use Case and external case in DFD The processes are transformed those into the Use Case and external case in DFD has same characteristics which of an actor in O

What is called bit-level striping, Normal 0 false false fal...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Why like predicate used for, Why Like predicate used for? LIKE predicat...

Why Like predicate used for? LIKE predicate: The LIKE predicate searches for strings in which have a certain pattern.

Creation of indexes, Creation of Indexes Automatically: When a primar...

Creation of Indexes Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically. Manually: User can

N-ary relationship, For every n-ary relationship type R where n>2, we make ...

For every n-ary relationship type R where n>2, we make a new table S to represent R. We contain as foreign key attributes in s the primary keys of the relations that show the parti

How are tables stored on disk?, How are tables stored on Disk? We reali...

How are tables stored on Disk? We realise that every record of a table can have different amounts of data. This is due to in some records; some attribute values may be "zero".

Develop and evaluate partial systems, Part 1: Security Plan Consider th...

Part 1: Security Plan Consider the Case study and identify 3 security requirements. For each of these security requirements: • Discuss the necessity for the feature and how

B2b business uk database, We have a new website where I need someone to 1: ...

We have a new website where I need someone to 1: Inhabit the back end with all the recruitment agencies in the UK. I require someone who is not manually going to do this, but who w

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