Storing Organizational Information

                                    •what is the information

                      Information is everywhere in an organization

                               •Information is stored in databases

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

                            •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

            •Entity – a person, place, thing, transaction, or event about which information is stored

The rows in each table contain the entities

In Figure 7.1 CUSTOMER includes Dave’s Sub Shop and Pizza Palace entities

            •Attributes (fields, columns) – characteristics or properties of an entity class

The 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 – 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

•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