Chapter 6: Relational Databases and Enterprise Systems

What is a database?

Collection of related data for various uses. It maintains information about various types of objects, events, people, and places

What are the three types of data models?

- Hierarchical Data Model

- Network Data Model

- Relational Data Model

What is a hierarchical data model?

Organizes data into a tree-like structure that allows repeating information using defined parent/child relationships

What is a network data model?

Flexible model representing object and their relationships

What is a relational data model?

Data model that stores information in the form of related two dimensional tables. Allows designers and users to identify relationships at the time the database is created

What are the benefits of a relational data model?

- Flexibility and Scalability: Handles changes quickly and easily

- Simplicity: Easy to communicate to both database users and database developers

- Reduced Information Redundancy: Relational data model requires each piece of data to be recorded only in one place

What is a database management system?

Computer program that creates, modifies, and queries the database and is designed to manage a database's storage and retrieval of information

What is a data dictionary?

Describes the data fields in each database record such as field description, field length, field type, etc.

What is a database administrator?

The person responsible for the design, implementation, repair, and security of a firm's database

What are the three main constructs of a relational database?

- Tables

- Attributes

- Records

What are tables?

Primary construct, used for data storage with rows and columns much like a spreadsheet. Each table in a database represents either a class or relationship between classes

What is an attribute?

Columns in a table are called fields that represent the attributes or characteristics of the class or relationship

What are records?

The rows in a table. It represents all the specific data values that are associated with one instance

What is the entity integrity rule?

The primary key of a table must have data values and cannot be null. Null means that there is no value

What is the referential integrity rule?

The data value for a foreign key must either be null or match one of the data values that already exist in the corresponding table

What are the basic requirements of tables of a relational database?

- Each attribute has a unique name

- The values of each attribute are the same type

- Each attribute (column) of a record (row) is single valued

What are enterprise systems?

Commercialized information systems that integrate and automate business processes across a firm's value chain