Chapter 5.8, Problem 5.6ARQ

Explanation of Solution

Three components of database design:

The three components of the database design are as follows:

• Tables
  • When data are organized in rows and columns, it is called as table.
• Relationship
  • The relationship laid between two tables are established using a row.
• Metadata
  • Metadata gives information about other data or simply, it is a data about the data.

Normalization:

When an unstructured table is converted in a way to form one or more properly structured table is called as normalization.

Importance of the normalization:

The main purpose of normalization is to convert the unstructured table into structured table and the importances to perform normalization are as follows:

• Eliminate data redundancy.
• Isolating the data such that any changes made in the table does not affect other contents.
• Ensures proper data dependencies.
• Makes data to be consistent through the table.

Data integrity problem:

Data integrity problem arises when the accuracy and consistency of the data stored in the database is not maintained.

• Consider the information present in a table needs to be updated and that change should be reflected to the entire database contents and if the contents are not properly updated then the data integrity problem arises.

Consequence of data integrity problem:

The main consequence of the data integrity problem is that the data contents present in the table are not properly updated and any action that needs to be processed for that table and those contents can produce inconsistency in the results.

• The results obtained from that table will be incorrect and inconsistent.

Example table with data integrity problem:

Consider the below table named “Bank” with the necessary contents:

Table name: Bank

Name	Date_of_join	Branch_id	BranchName
James	Mar 3,2014	101	S1B
Rita	Jan 22,2011	100	MB
Ron	Oct 2,2000	108	S8B
joules	Aug 21,2002	100	MB
Zita	Jan 22,2011	100	MB
Larry	Apr 2,2000	108	S8B

In the above the table, the name of the branch “MB” has to be changed to “MSB”:

Table name: Bank

Name	Date_of_join	Branch_id	BranchName
James	Mar 3,2014	101	S1B
Rita	Jan 22,2011	100	MSB
Ron	Oct 2,2000	108	S8B
joules	Aug 21,2002	100	MB
Zita	Jan 22,2011	100	MSB
Larry	Apr 2,2000	108	S8B

In the above table, the highlighted content of the table is found to be improperly updated and will lead to data integrity problem. When the data of the account holders whose branch name of “MSB” needs to be counted but since the data has been improperly updated the count of the result produced will be incorrect and to avoid this kind of problem normalization is the best choice.

Normalization of a table:

The above table “Bank” is being normalized to avoid the data integrity problem and needs to be split into two tables to obtain data consistency in them.

Table name: Bank

Name	Date_of_join	Branch_id
James	Mar 3,2014	101
Rita	Jan 22,2011	100
Ron	Oct 2,2000	108
joules	Aug 21,2002	100
Zita	Jan 22,2011	100
Larry	Apr 2,2000	108

Table name: NameofBranch

Branch_id	BranchName
100	MSB
101	S1B
108	S8B

Therefore, from the above table, the redundancy of the data is being avoided, thus avoiding the inconsistency with the contents of the table...