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

Introduction to Database Design and Development, Every School has many teac...

Every School has many teachers and many students. Each student is assigned to one school and each teacher works for one school only. Each teacher teaches more than one subject but

What are the drawbacks of file oriented system in details, What are the dr...

What are the drawbacks of File Oriented System in details?

What is deadlock, What is deadlock? How can it be avoided? How can it be re...

What is deadlock? How can it be avoided? How can it be resolved once it occurs? Deadlock happens when two transactions are each waiting on a resource that the other transaction

Structure of client server systems, Structure of Client Server Systems: In ...

Structure of Client Server Systems: In client/server architecture, clients show users who require services while servers give services. Both client and server are a combination of

Research in Concurency Control Protocols, Performance of Various Concurrenc...

Performance of Various Concurrency Control Mechanisms

Database for Managers, I have to create a database about anything of my cho...

I have to create a database about anything of my choice. It has to contain 4 queries, and 4 forms. It can be anything as simple as a shoe inventory with numbers - is this a service

What are the advantages of logical databases, What are the advantages of Lo...

What are the advantages of Logical Databases? It offers a simple-to-use selection screens.  You can change the pre-generated selection screen to your needs.  It offers check f

Name the metrics for selecting top algorithm, Name the metrics for selectin...

Name the metrics for selecting top algorithm There are a number of metrics for selecting top algorithm: i) Computational complexity: Computational complexity refers to eff

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

Demonstrate the design of associations, Demonstrate the Design of associati...

Demonstrate the Design of associations During object design phase we must design a strategy to implement associations. Association may be unidirectional or bi-directional. Wha

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