Chapter 6, Problem 3P

a.

Program Plan Intro

Normalization:

The process used to minimize data redundancy and dependency in a relational database is known as normalization. The database table is divided into two or more tables and defines the relationship between those tables.

Second normal form (2NF):

• The value of all non-primary key attributes should be dependent on the primary key attribute.
  • If any attribute is depending on the partial primary key then it should determine the other attributes for an instance of the entity.
• The partial dependencies should be removed from the data model.

Third normal form (3NF):

• The value of any non-primary key attributes will not depend on any other non-primary key attributes.
  • If any non-primary key attributes depend on any other non-primary key attribute then it should be moved or deleted.
  • It is termed as transitive dependency.

Partial dependency:

A partial dependency exists at that time of an attributes depends only a part of primary key. This dependency is related with 1^st normal form.

Transitive dependency:

A transitive dependency exists at that time of an attributes depends on another attribute which is not part of primary key.

Functional dependency:

An association between two attributes or two set of attributes in a same relational database table, which is having some constraints is known as functional dependency.

• In a table one attribute is functionally dependent on another attribute to take one value.

Explanation of Solution

Construct the dependency diagram with all partial and transitive dependencies:

The relational schema for given INVOICE table is given below:

Invoice(INV_NUM, PROD_NUM, SALE_DATE, PROD_LABEL, VEND_CODE, VEND_NAME, QUANT_SOLD, PROD_PRICE)

• Here, “INV_NUM” and “PROD_NUM” indicates the primary key.

The representation of dependency diagram with all partial and transitive dependencies is shown below:

Explanation:

In the above dependency diagram,

• The partial dependencies are,

  INV_NUM -> (SALE_DATE)

  PROD_NUM -> (PROD_LABEL, VEND_CODE, VEND_NAME, PROD_PRICE)

• The transitive dependency is,

  VEND_CODE -> (VEND_NAME)

b.

Program Plan Intro

Normalization:

The process used to minimize data redundancy and dependency in a relational database is known as normalization. The database table is divided into two or more tables and defines the relationship between those tables.

Second normal form (2NF):

• The value of all non-primary key attributes should be dependent on the primary key attribute.
  • If any attribute is depending on the partial primary key then it should determine the other attributes for an instance of the entity.
• The partial dependencies should be removed from the data model.

Third normal form (3NF):

• The value of any non-primary key attributes will not depend on any other non-primary key attributes.
  • If any non-primary key attributes depend on any other non-primary key attribute then it should be moved or deleted.
  • It is termed as transitive dependency.

Partial dependency:

A partial dependency exists at that time of an attributes depends only a part of primary key. This dependency is related with 1^st normal form.

Transitive dependency:

A transitive dependency exists at that time of an attributes depends on another attribute which is not part of primary key.

Functional dependency:

An association between two attributes or two set of attributes in a same relational database table, which is having some constraints is known as functional dependency.

• In a table one attribute is functionally dependent on another attribute to take one value.

Explanation of Solution

Construct the dependency diagram by removing all partial dependencies:

The new dependency diagram is represented by removing all partial dependencies in INVOICE table.

First table:

The relational schema for first table is given below:

 3NF(INV_NUM, PROD_NUM, SALE_DATE, QUANT_SOLD)

• Here, “INV_NUM” and “PROD_NUM” indicates the primary keys.
• The relation is in third normal form (3NF), since there is no transitive dependency and no repeated attributes.

The representation of dependency diagram removes all partial dependencies in first table are shown below:

Second table:

The relational schema for second table is given below:

3NF(INV_NUM, SALE_DATE)

• Here, “INV_NUM” indicates the primary key.
• The relation is in third normal form (3NF), since there is no transitive dependency and no repeated attributes.

The representation of dependency diagram removes all partial dependencies in second table are shown below:

Third table:

The relational schema for third table is given below:

2NF(PROD_NUM, PROD_LABEL, VEND_CODE, VEND_NAME, PROD_PRICE)

• Here, “PROD_NUM” indicates the primary key.
• The relation is in third normal form (2NF), since there is transitive dependency in table.

The representation of dependency diagram removes all partial dependencies in third table are shown below:

c.

Program Plan Intro

Normalization:

The process used to minimize data redundancy and dependency in a relational database is known as normalization. The database table is divided into two or more tables and defines the relationship between those tables.

Second normal form (2NF):

• The value of all non-primary key attributes should be dependent on the primary key attribute.
  • If any attribute is depending on the partial primary key then it should determine the other attributes for an instance of the entity.
• The partial dependencies should be removed from the data model.

Third normal form (3NF):

• The value of any non-primary key attributes will not depend on any other non-primary key attributes.
  • If any non-primary key attributes depend on any other non-primary key attribute then it should be moved or deleted.
  • It is termed as transitive dependency.

Partial dependency:

A partial dependency exists at that time of an attributes depends only a part of primary key. This dependency is related with 1^st normal form.

Transitive dependency:

A transitive dependency exists at that time of an attributes depends on another attribute which is not part of primary key.

Functional dependency:

An association between two attributes or two set of attributes in a same relational database table, which is having some constraints is known as functional dependency.

• In a table one attribute is functionally dependent on another attribute to take one value.

Explanation of Solution

Construct the dependency diagram by removing all transitive dependencies:

The new dependency diagram is represented by removing all transitive dependencies in INVOICE table.

First table:

The relational schema for first table is given below:

 3NF(INV_NUM, PROD_NUM, QUANT_SOLD)

• Here, “INV_NUM” and “PROD_NUM” indicates the primary keys.
• The relation is in third normal form (3NF), since there is no transitive dependency and no repeated attributes.

The representation of dependency diagram removes all partial dependencies in first table are shown below:

Second table:

The relational schema for second table is given below:

3NF(INV_NUM, SALE_DATE)

• Here, “INV_NUM” indicates the primary key.
• The relation is in third normal form (3NF), since there is no transitive dependency and no repeated attributes.

The representation of dependency diagram removes all transitive dependencies in second table are shown below:

Third table:

The relational schema for third table is given below:

3NF(VEND_CODE, VEND_NAME)

• Here, “VEND_CODE” indicates the primary key.
• The relation is in third normal form (3NF), since there is no transitive dependency and no repeated attributes.

The representation of dependency diagram removes all transitive dependencies in third table are shown below:

Fourth table:

The relational schema for final table is given below:

2NF(PROD_NUM, PROD_LABEL, VEND_CODE, PROD_PRICE)

• Here, “PROD_NUM” indicates the primary key.
• The relation is in third normal form (3NF), since there is no transitive dependency and no repeated attributes.

The representation of dependency diagram removes all transitive dependencies are shown below:

d.

Explanation of Solution

The representation of Crow’s Foot Entity Relational Diagram (ERD) is shown below:

The following data model shows the solution for the given question.

Explanation:

• In the above data model, one invoice can contains many invoice line.
  • The “INVOICE” entity contains the “INV_NUM” and “SALE_DATE” attributes.
    • The primary key of “INVOICE” entity is “INV_NUM”.
  • The “INV_LINE” entity contains the “INV_NUM”, “PROD_NUM” and “QUANT_SOLD” attributes.
    • The primary and foreign key of this entity is “INV_NUM”.
    • The foreign key of this entity is “PROD_NUM”.
• The product is written in more than one invoice line.
  • The “PRODUCT” entity contains the “PROD_NUM”, “VEND_CODE”, “PROD_LABEL”, and “PROD_PRICE” attributes.
    • The primary key of “PROD_NUM” for this entity.
    • The foreign key of this entity is “VEND_CODE”.
• The vendor supplies more than one product.
  • The “VENDOR” entity contains the “VEND_CODE” and “VEND_NAME” attributes.
    • The primary key of “VEND_CODE” entity.