11.4.2.1 explain the purpose of the data dictionary

Data dictionary

The data dictionary is a collection of details that describes the content, layout, and organisation of a database, including the relationships between its components.

This vital tool is employed to regulate both access to and the modification of the database, ensuring consistent data handling and integrity.

Database users usually do not interact with the data dictionary, this is only available to database administrators.

The data dictionary describes:

• Contents
• Format
• Structure of a database
• Relationship between its entities or objects

In the project work, the data dictionary is used at the design stage in order to determine the content of database tables:

• field name
• the type of fields
• the length of each field for display
• validation to be used
• a description of the field content
• an example of the value

Data dictionary of table "Students_of_NIS".

Questions:

1. Explain the term "Data dictionary".

2. Give the list of what the data dictionary describes.

Exercises:

Ex. 1

Quiz "Validation and Verification"

Ex. 2

A school plans to keep records of Sports Day events for different years in a database. The data that needs to be held for each event in a particular year is illustrated in the following table Results:

Create Data dictionary for table Results

Exam questions: