Chapter 7 : Storing Organizational Information

Relational Database Fundamentals :

• Database - maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses).
• Hierarchical database model - information is organized into a tree-like structure 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.

Attributes
=> Characteristics or properties of an entity class.

Keys and Relationships :

• 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.  

Relational Database Advantages :

• Increased flexibility.                                                                  

Physical view - deals with the physical storage of information on a storage device.

Logical view - focuses on how users logically access information. 

• Increased scalability and performance.

Scalability - refers to how well a system can adapt to increased demand.

Performance - measures how quickly a systems performs a certain process or transaction.

• Reduced information redundancy.

Redundancy - the duplication of information or storing the same information in multiple places. \

• Increase information integrity ( quality ).

Information integrity - measures the quality of information. 

Integrity constraint - rules that help ensure the quality of information. 

• Increased information security.

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.

Data-Driven Website Business Advantages :

• Development.
• Content management.
• Future expandability.
• Minimizing human error.
• Cutting production and update costs.
• More efficient.
• Improved stability.

Integrating Information among Multiple Databases :

• Integration - allows separate systems to communicate directly with each other.
• Forward integration - takes information entered into a given systems 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.