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

Dbms built for online transaction processing, Problem: A DBMS built for...

Problem: A DBMS built for Online Transaction Processing (OLTP) is usually regarded as unsuitable for data warehousing. Each system is designed with a different set of requireme

What is sql?, What Is Sql?  Structured Query Language (SQL) is a standa...

What Is Sql?  Structured Query Language (SQL) is a standard query language. It is usually used with all relational databases for data manipulation and definition. All the re

What are the advantages of embedded query language, What are the advantages...

What are the advantages of embedded query language? Give an example of an embedded SQL query. Embedded query language - SQL could be implemented within two ways. It can be us

Need web-based database, Our company hires independent contractors to insta...

Our company hires independent contractors to install equipment at precise locations across North America. We want to track the installation data and generate reports. The compan

What is the state machine engine, What is the State Machine Engine The...

What is the State Machine Engine The straightest approach to implement control is to have any way of explicitly representing and executing state machines. With the help of thi

Which sorting technique is used to sort databases, Which sorting technique ...

Which sorting technique is used to sort databases, whose sizes are very big?  Give one such algorithm.  Why do sorting techniques like quicksort, insertion sort, etc.  not applied

Need for client server computing, Need for Client Server Computing- Client/...

Need for Client Server Computing- Client/Server (C/S) architecture includes running the application on multiple machines in which every machine with its component software tackles

Explain how the law ensures data protection and security, Question 1: (...

Question 1: (a) Explain the legal meaning of :- (i) Computer Service Person (ii) Data holding (b) Explain how the law ensures Data protection and Security. Qu

Explain the function of input controls, Explain the function of input contr...

Explain the function of input controls. Identify four types of input control and explain the function of each. Provide an example of a data integrity error that could occur i

Domain constraints, Domain Constraints Domain constraints are primarily...

Domain Constraints Domain constraints are primarily formed for defining the logically correct values for an attribute of a relation. The relation allows attributes of a relatio

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