CHAPTER 7 : STORING ORGANIZATIONAL INFORMATION - DATABASES

Relational Database Fundamentals 

• database maintains information about various type of object (inventory), events (transactions), people (employees), and places (ware-house).
• In hierarchical database model, information is organized into a tree-like structure that allows repeating information using parent/child relationships in such a way that it cannot have too many relationships
• the network database model is a flexible way of representing objects and their relationships.
• the relational database model is a type of database that stores information in the form of logically related two-dimensional tables.

Entities and Attributes

• entity in the relational database model is a person,place,thing,transaction, or events about which information is stored.
• attributes also called fields or columns , are characteristics or properties of an entity class. 

Keys and Relationships

•  a primary key is a fields (or group of fields) that uniquely identifies a given entity in the table.
• a foreign key in the relational database model is a primary key of one table that appears as an attribute in another table and acts to provide a logical relationship between the two tables.

relational database advantages

• increased flexibility 
• increased scalability and performance
• reduced information redundancy
• increased information integrity (quality)
• increased information security

Increased Flexibility

• database tends to mirror business structures, and a good database can handle changes quickly and easily, just as any good business need to be able to handle changes quickly and easily
• the physical view of information deals with the physical storage of information on a storage device such as hard disk.
• logical view of information focuses on how users logically access information to meet their particular business needs.

Increased scalability and performance

• scalability refers to how well system can adapt to increased demands.
• performance measure how quickly system performs a certain process or transaction.

Reduced information redundancy

• redundancy is the duplication of information, or storing the same information in multiple places.
• redundant information occurs because organizations frequently capture and store the same information in multiple location.

Increased information integrity (quality)

• information integrity is a measure of the quality of information.
• integrity constraints are rules that help ensure the quality of information.
• relational integrity constraints are rules that enforces basic and fundamental information-based constraints.
• business-critical integrity constraints enforce business rules vital to an organization's success and often require more insight and knowledge than relational integrity constraints.

database management system (DBMS)

• DBMS is software through which users and application programs interact with a database.

data driven websites

• data driven websites is an interactive website kept constantly update and relevant to the needs of its customers through the use of a database.

integrating information among multiple databases

• integration allows separate system to communicate directly with each other.
• forward integration takes information entered into a given system and send it automatically to all downstream systems and processes.
• a backward integration takes information entered into a given system and send it automatically to upstream system and process.