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Thursday 30 January 2014

Chapter 7 (Storing Organizational Information)

What is Information

v  Relational Database Fundamentals
v  Information is everywhere in an organization
v  Information is stored in databases

§  Database – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)

Relational Database Fundamentals

v  Database models include:
§  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 – a 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


v  Entity – a person, place, thing, transaction, or event about which information is stored
§  The rows in each table contain the entities
§  Attributes (fields, columns) – characteristics or properties of an entity class
§  The columns in each table contain the attributes

Keys and Relationships

v  Primary keys and foreign keys identify the various entity classes (tables) in the database
§  Primary key – a field (or group of fields) that uniquely identifies a given entity in a table
§  Foreign key – a 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

v  Potential relational database for Coca-Cola

Relational Database Advantages

v  Database advantages from a business perspective include
§  Increased flexibility
§  Increased scalability and performance
§  Reduced information redundancy
§  Increased information integrity (quality)
§  Increased information security

Increased Flexibility

v  A 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

v  A 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

v  Databases reduce information redundancy
§  Redundancy – the duplication of information or storing the same information in multiple places
v  Inconsistency is one of the primary problems with redundant information

Increase Information Integrity (Quality)

v  Information integrity – measures the quality of information
v  Integrity constraint – rules that help ensure the quality of information
§  Relational integrity constraint
§  Business-critical integrity constraint

Increased Information Security

v  Information is an organizational asset and must be protected
v  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


v  Database management systems (DBMS) – software through which users and application programs interact with a database


DATA-DRIVEN WEB SITES

v  Data-driven Web sites – an interactive Web site kept constantly updated and relevant to the needs of its customers through the use of a database

Data-Driven Web Site Business Advantages

v  Development
v  Content Management
v  Future Expandability
v  Minimizing Human Error
v  Cutting Production and Update Costs
v  More Efficient
v  Improved Stability

Data-Driven Business Intelligence

v  BI in a data-driven Web site

  Integrating Information 

v  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


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