MANAGEMENT

INFORMATION SYSTEMS

Chapter 7: Storing Organizational Information Databases

Learning Outcomes

1. Define the fundamental concepts of the relational database model.

2. Evaluate the advantages of the relational database model.

3. Define a database management system and its relationship to a website.

4. Explain why an organization would want to integrate its databases.

Database Fundamentals

Information is everywhere in an organization

Information is stored in databases

Database = maintains information about various types of:

Objects (i.e. inventory)

Events (i.e. transactions)

People (i.e. employees)

Places (i.e. warehouses)

Database Fundamentals

Database management system = computer program

used to manage and query a database

Database properties:

Data are managed to ensure integrity and quality

Allows shared access across a community of users

Has a schema

Supports a query language

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Database Models

Hierarchical database model = information is organized

into a tree-like structure (using parent/child

relationships) in such a way that it cannot have too

many relationships

Network database model = flexible way of representing

objects and their relationships

Relational database model = stores information in the

form of logically related two-dimensional tables

Entities and Attributes

Entity = person, place, thing, transaction, or event about

which information is stored

Rows in each table contain the entities

In Figure 7.1 CUSTOMER includes Daves Sub Shop and

Pizza Palace entities

Attribute (fields, columns) = characteristics or properties

of an entity class

Columns in each table contain the attributes

In Figure 7.1 attributes for CUSTOMER include Customer

ID, Customer Name, Contact Name

Keys and Relationships

Primary keys and foreign keys identify the various entity

classes (tables) in the database

Primary key = field (or group of fields) that uniquely

identifies a given entity in a table

Foreign key = primary key of one table that appears an

attribute in another table and acts to provide a logical

relationship among the two tables

Keys and Relationships

Advantages of Relational Database

Increased flexibility

Increased scalability and performance

Reduced information redundancy

Increased information integrity (quality)

Increased information security

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Increased Flexibility

Well-designed database should:

Handle changes quickly and easily

Provide users with different views

Have only one physical view

Physical view = deals with the physical storage of

information on a storage device

Have multiple logical views

Logical view = focuses on how users logically

access information

Increased Scalability and Performance

Database must scale to meet increased demand, while

maintaining acceptable performance levels

Scalability = refers to how well a system can adapt to

increased demands

Performance = measures how quickly a system performs a

certain process or transaction

Reduced Information Redundancy

Databases reduce information redundancy

Redundancy = duplication of information or storing the

same information in multiple places

Inconsistency is one of the primary problems with

redundant information

Increase Information Integrity (Quality)

Information integrity = measures the quality of information

Integrity constraint = rules that help ensure the quality of information

Relational integrity constraint

Business-critical integrity constraint

Increased Information Security

Information is an organizational asset and must be

protected

Databases offer several security features including:

Password = provides authentication of the user

Access level = determines who has access to the

different types of information

Access control = determines types of user access,

such as read-only access

Database Management Systems

Database management systems (DBMS) = software

through which users and application programs interact with

a database

Data-Driven Websites

Data-driven websites = interactive website kept constantly

updated and relevant to the needs of its customers through

the use of a database

Advantages of Data-Driven Website

Development

Content management

Future expandability

Minimizing human error

Cutting production and update costs

More efficient

Improved stability

Data-Driven Business Intelligence

BI in a data-driven website

Integrating Information

Integration = allows separate systems to communicate directly with each other

Forward integration = takes information entered into a given system and sends it automatically to all downstream systems and processes

Backward integration = takes information entered into a given system and sends it automatically to all upstream systems and processes

Integrating Information Forward Integration

Integrating Information Backward Integration

Integrating Information

Building a central repository specifically for integrated information