Eliminate redundant data, Database Management System

Assignment Help:

 Eliminate Redundant Data

In the "Database Relation" above, the primary key is made up of the D-ID and the Emp-ID. The database-name relies only on the D-ID. The similar database-name will appear redundantly every time its associated D-ID appears in the Database Relation. The database relation has redundancy, for example D-ID value 4 is oracle is repetitive twice. In addition, it also experiences insertion anomaly that is we cannot enter Sybase in the relation as no employee has that skill.

The deletion anomaly also exists. For instance, if we remove employee with Emp-ID 3; no employee with FoxPro knowledge lefts and the information that D-ID 3 is the code of FoxPro will be gone.

To avoid these troubles, we require second normal form. To achieve this, we isolate the attributes depending on both parts of the key from those depending only on the D- ID. This result in two relations: "Database" which gives the name for every D-ID,

and "Emp-database" which lists the databases for each employee. The employee relation is already in 2NF as all the EMP-ID determines all different attributes

Employee Relation

 Emp-ID

Emp-Name

1

Gurpreet Malhotra

2

Faisal Khan

3

Manisha Kukreja

4

Sameer Singh

 

Emp-database

Relation

Emp-ID

D-ID

2

1

4

2

3

3

1

4

4

4

 

 

 

 

Database Relation

D-ID

Database

1

Access

2

DB2

3

FoxPro

4

Oracle


Related Discussions:- Eliminate redundant data

How the one-to-one associations have to be implemented, Discuss how the one...

Discuss how the one-to-one associations have to be implemented. Some of properties of associations can be implemented directly by providing suitable declarations of the data me

Database design in third normal form, The following data are required to be...

The following data are required to be stored by a family physician. Family#, FamilyAddress, Patient#, PatientName, ServiceCode, ServiceFee, ServiceDate A family can have seve

Appointment systems with sms and voice call feedback, Automated system for ...

Automated system for appointment with sms and call confirmation with service providers and user has to be initiate automatically. After selecting time and date to use service, s

What is cross product, What is Cross Product? Simply Cross product is B...

What is Cross Product? Simply Cross product is Binary Operator

What are the objectives of query processing, What are the objectives of que...

What are the objectives of query processing?       Ans: The objectives of query processing is to transform a query written in a high level language into a accurate and efficien

Explain briefly concurrent task by taking an example, Explain briefly concu...

Explain briefly concurrent task by taking an example. Concurrent Task- The concurrent occurrence of more than one event is called concurrent task. Operating systems can handl

What is meant by buffer blocks and disk buffer, What is meant by buffer blo...

What is meant by buffer blocks and disk buffer   The blocks residing temporarily in main memory are referred to as buffer blocks. The area of memory where blocks reside t

Unit database integrity, Relations create the database. They must satisfy v...

Relations create the database. They must satisfy various properties, like no duplicate tuples, no ordering of tuples, and atomic attributes, etc. Relations that satisfy these basic

Inconsistent analysis-problems of concurrent transactions, Inconsistent Ana...

Inconsistent Analysis : The problem as given with transactions T1 and T2 where two transactions interleave to make incorrect result during an analysis by Audit is the instance of s

Determine the un-normalized form, Un-Normalized Form (UNF) If a table h...

Un-Normalized Form (UNF) If a table having non-atomic values at every row, it is said to be in UNF. An atomic value is something that cannot be further decomposed. A non-atomic

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