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MIS Ch7 Databases
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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
7-4
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
7-9
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
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