CAHPTER 7 : STORING ORGANIZATIONAL INFORMATION-DATABASE
Relation Database Fundamentals
- Information is everywhere in a organization.
- Information is stored in databases
a) Database - maintains information about various types of objects(inventory),events
(transactions),people(employees),and places(warehouse).
b) 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
- Entity - a person,place,thing,transaction,or event about which information is stored
a) The rows in each table contain entities
b) In Figure 7.1 Customer includes Dave'Sub Shop and Pizza Places entities.
- Attributes(fields,columns) - characteristics or properties of an entity class.
a) The columns in each table contain the attributes.
b) In Figure 7.1 attributes for Customer include Customer ID,Customer Name,Contact Name.
Key and Relationships
- Primary keys and foreign keys identify the various entity classes(tables) in the database.
a) Primary key - a field (or group of fields) that uniquely identifies a given entity in a table.
b) Froreign key - a primary of one table that appears an attribute in another table and acts to
provide a logical relationship among the two tables.
Keys and Relationships ( Example)
Potential relational database for Coca-Cola.
Relational Database Advantages
- Increased flexibility
a) Handle changes quickly and easily
b) Provide users with different views
c) Have only one physical view
- Physical view - deals with the physical storage of information on a storage of information on a
storage device, eg : hard disk
d) Have multiple logical view
- Logical view - focuses on how uses logically accesss information,eg : a mail-order buss- 2
people view diff format (logical views) but the same physical view.
- Increased scalability and performance
a) A database must scale to meet increased demand,while maintaining acceptable performance
level,eg : scalability and performance.
- Reduced information redundancy
a) Database reduce information redundancy.
- Redundancy - the duplication of information or storing the same information in multiple places.
- Increased information integrity (quality)
a) Information integrity is measures the qualityof information.
b) Integrity constraint is rule that help ensure the quality of information.Example : Relational
integrity constraint and business-critical integrity constraint.
- Increased information security
a) Information is an organizational asset and must be protected.
b) Database offer several security features including : password,access level and access control.
Database Management Systems
- Database management systems( DBMS) is software through which users and application programs
interact with database.
Data-Driven Web Sites
- Data-driven Web site is an interaction Web site kept constantly updated and relevant to the needs
of its customers through the use of database.
Data-Driven Web Site Business Advantages
- Development
- Content management
- Future expandability
- Maximizing human error
- Cutting production and update costs
- More efficient
- Improved stability
Data-Driven Business Intelligence
- Business intelligence in a data-driven Web site
Integrating Information among Multiple Databases
- Integration is allows separate systems to communicate directly with each other is foward integration
and backward integration.
- Forward integration and backward integration
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