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

Architecture, With the help of a suitable diagram gives module wise explana...

With the help of a suitable diagram gives module wise explanation of system architecture of DBMS.on..

Explain er relationship model, Explain ER Relationship model? An entity...

Explain ER Relationship model? An entity-relationship model (ERM): An entity-relationship model (ERM) is an abstract theoretical illustration of structured data. Entity-relatio

Benefits of views-data control, Benefits: It limits data access. ...

Benefits: It limits data access. It makes difficult queries look easy. It permits data independence. It presents dissimilar views of the similar data.

Define object-relational systems, Define object-relational systems? Sy...

Define object-relational systems? Systems that give object-oriented extensions to relational systems are known as object-relational systems.

Multilevel indexing scheme, Multilevel Indexing Scheme Consider the ind...

Multilevel Indexing Scheme Consider the indexing scheme where the address of the block is consider in the index for each record, for a little file, this index would be little a

What is data storage, What is Data Storage? The storage structures and ...

What is Data Storage? The storage structures and access methods used by database system are specified by a set of explanation in a special type of DDL called data storage-defin

Differance between ddl and sdl, Differance between DDL and SDL? DDL and...

Differance between DDL and SDL? DDL and SDL - The data definition language (DDL) is used through DBA and database designers to describe internal schema, conceptual schema, and

What are aggregate functions, What are aggregate functions? And list the ag...

What are aggregate functions? And list the aggregate functions supported by SQL? Aggregate functions are functions that take a collection of values as input and return a one va

Define the terms physical schema and logical schema., Define the terms 1) p...

Define the terms 1) physical schema 2) logical schema. Physical schema: The physical schema explains the database design at the physical level, which is the lowest level of abs

Explain forms based and graphical interface, Explain forms based and graphi...

Explain forms based and graphical interface? Forms based and graphical interface: graphical user interface (GUI) is a kind of user interface which permits people to interact

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