Chapter 8 : Conceptual Data Modeling

Question 1

Data Dictionary is also known as what?

Answer 1

1. Data Repository

Question 2

What is metadata?

Answer 2

1. Data about data

Question 3

What is the usage of Data Dictionary? ( 6 )

Answer 3

1. Provide documentation
2. Eliminate redundancy
3. Validate data flow diagram for completeness & accuracy
4. Provide a starting point for developing screens and reports
5. Determine the contents of data stored in files
6. Develop the logic for data flow diagram processes

Question 4

What can we write when writing external entity? ( 3 )

Answer 4

1. Name
   
   • External Entity Name
   • Appears on DFDs
2. Description
   
   • External Entity and Purpose
3. Input Data Flows
   
   • Standard DFD Names for Input Data Flows into external entity
4. Output Data Flows
   
   • Standard DFD names for the output data flows

Question 5

List out Examples of External Entity

Answer 5

1. Name
   
   • Customer
2. Description
   
   • Customer register details to obtain
   • Login details such as login and password
3. Input Data Flows
   
   • Login Details
4. Output Data Flows
   
   • Customer Details

Question 6

What can we write when writing process? ( 3 )

Answer 6

1. Name
2. Description
3. Input Data Flows
4. Output Data Flows

Question 7

List out examples of Process

Answer 7

1. Name
   
   • 1.0 Register Customer
2. Description
   
   • Register customer details into the customer records and retrieves randomly generated password with login
3. Input Data Flows
   
   • Customer Details, Updated Customer Details
4. Output Data Flows
   
   • Login Details, Registration Details

Question 8

What can we write when writing data flow? ( 3 )

Answer 8

1. Name
2. Description
3. Origin / Source
4. Destination
5. Data Structure
   
   • Also known as record

Question 9

List out the examples of Data Flow ( 5 )

Answer 9

1. Name
   
   • Login Details
2. Description
   
   • To allow the customer to log on into the system
3. Origin / Source
   
   • Register Customer Process
4. Destination / Sink
   
   • Customer External Entity
5. Data Structure
   
   • Login ID , Password

Question 10

What can we write when writing data store? ( 3 )

Answer 10

1. Name
2. Description
3. Input Data Flows
4. Output Data Flows
5. Data Structure

Question 11

List out examples of Data Store

Answer 11

1. Name
   
   • Customer Record
2. Description
   
   • Stores registeration details
   • Provided updated customer details for processes
3. Input Data Flows
   
   • Registeration Details
4. Output Data Flows
   
   • Updated Customer Details
5. Data Structure
   
   • Customer ID, Name, Address, Phone, Email

Question 12

What is Entity Relationship Diagra? ( ERD , 2 )

Answer 12

1. A model that shows the logical relationship and interaction among system entities
2. Provides an overall view of the system and a blueprint for creating the physical structures

Question 13

What is Entities? ( 2 )

Answer 13

1. Objects or Concepts that can have data stored about them
2. Refer to tables used in Databases

Question 14

What is Attributes ?

Answer 14

1. Properties or Characteristics of Entities

Question 15

List out examples for ERD

Answer 15

1. Entities
   
   • Student
   • Course
2. Attributes
   
   • Stu_Id
   • Stu_Name
   • Stu_Age
   • Cou_Id
   • Cou_Name

Question 16

List out 3 types of Relationship

Answer 16

1. One-to-One
2. One-to-Many
3. Many-to-Many