Chapter 8

Question 1

What can dataflow diagrams be used to catalog?

Answer 1

Data processes
Flows
Stores
Structures
Elements

Question 2

Data dictionary

Answer 2

• A reference work of data about data (metadata)
• Collects and coordinates data terms, and confirms what each term means to
  different people in the organisation
• The bridge between processes and data structures/stores

Question 3

What is the need for understanding the data dictionary?

Answer 3

• Provide documentation
• Eliminate redundancy
• Validate data flow diagram
• Provide a starting point for developing screens and reports
• Determine the contents of data stored in files
• Develop logic for DFD processes

Question 4

Data repository

Answer 4

large collection of project information

Question 5

What does the data repository include?

Answer 5

• Information about data maintained by the system
• Procedural logic and use cases
• Screen and report design
• Data relationships
• Project requirements and final system deliverables
• Project management information

Question 6

Data dictionary categories

Answer 6

Data flows
Data structures
Elements
Data stores

Question 7

Algebraic notation used to describe data structures

Answer 7

=
is composed of

+
and

{ }
repetitive elements

[ ]
either/or situation

( )
optional element

Question 8

Structural records

Answer 8

• Structure may consist of elements or structural records
  Group of elements such as:
  o Customer name
  o Address
  o Telephone
• Each element is further defined until it is broken down into component elements

Question 9

what does the notation mean?

{ C }

Answer 9

C is repeating but is optional

Question 10

what does the notation mean?

[ C | D | E]

Answer 10

There is an option to choose C, D or E

Question 11

Logical data structures

Answer 11

Show what data the business needs for its day to day operations

Question 12

Physical data structures

Answer 12

Includes additional elements necessary for implementing the system

Question 13

Features of physical data structures

Answer 13

• Key fields used to locate records
• Codes to identify record status
• Transaction codes to identify different record types
• Repeating group entities
• Limits on items in a repeating group
• Password

Question 14

Data element characteristics

Answer 14

• Element ID
• Name of element
• Aliases
• Short description
• Element is base or derived - - Element length
• Type of data
• Validation criteria
• Default value

Question 15

Element ID

Answer 15

• Optional Entry

- Allows analyst to build automated data dictionary entries

Question 16

Base Element

Answer 16

Initially keyed into the system

Question 17

Derived Element

Answer 17

Created by a process, usually as the result of a calculation

Question 18

Types of data

and formats

Answer 18

Alphanumeric or text
Formats:
o Mainframe: packed, binary, display
o Microcomputer (PC) formats
o PC formats like currency, number

Question 19

Creating the data dictionary

Answer 19

• Entries are created after data flow diagram is completed or as data flow diagram is being developed
• Created using top down approach
  o Structure
  o Elements
  o Break down elements

Question 20

Developing data stores

Answer 20

• Represent data at rest
• Contain information of a permanent or semi permanent nature
• “User views” If data stores are created for only one report or screen