Chapter 7

STORING ORGANIZATIONAL INFORMATION

Relational Database Fundamentals

• 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.

Entities and Attributes

• 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

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.

Potential relational database for Coca-Cola

Relational Database Advantages

Database advantages from a business perspective include: 

   i)    Increased flexibility. 

   ii)   Increased scalability and performance. 

   iii)  Reduced information redundancy. 

   iv)  Increased information integrity (quality). 

   v)   Increased information security. 

i) Increased flexibility

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.

ii) Increased scalability and performance

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.

iii) Reduced information redundancy

Databases reduce information redundancy.

• Redundancy – the duplication of information or storing the same information in multiple places. 
• Inconsistency is one of the primary problems with redundant information.

iv) Increase information integrity

Information integrity – measures the quality of information.
Integrity constraint – rules that help ensure the quality of information.

• Relational integrity constraint - rule that enforces basic and fundamental information-based constraints.
• Business-critical integrity constraint - rule that enforce business rules vital to an organization’s success and often require more insight and knowledge than relational integrity constraints.

v) Increased information security

Information is an organizational asset and must be protected.
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 System

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

Direct interaction :

• The user interacts directly with the DBMS
• The DBMS obtains the information from the database

Indirect interaction:

• User interacts with an application (i.e., payroll application, manufacturing application, sales application)
• The application interacts with the DBMS
• The DBMS obtains the information from the database

Data-driven Websites

A data-driven Web site is an interactive Web Site kept constantly updated and relevant to the needs of its customers through the use of a database. Data-driven Web sites are especially useful when the site offers a great deal of information, products, or services. Web site visitors are frequently angered if they are buried under an avalanche of information when searching a Web site. A data-driven Web site invites visitors to select and view what they are interested in by inserting a query, which the Web site then analyzes and custom builds a Web page in real-time that satisfies the query. The figure displays a Wikipedia user querying business intelligence and the database sending back the appropriate Web page that satisfies the user’s request.

Data-driven Website Advantages

1. Development

2. Content management

3. Future expandability

4. Minimizing human error

5.Cutting production and update costs

6.More efficient

7. Improved Stability

Data-driven Business Intelligence

Business Intelligence in a data-driven Web site:

Companies can gain business intelligence by viewing the data accessed and analyzed from their Web site.  The figure displays how running queries or using analytic tools, such as a Pivot Table, on the database that is attached to the Web site can offer insight into the business, such as items browsed, frequent requests, items bought together, etc.

Integrating Information Among Several Databases

• 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.

Building a Central Repository Specifically For Integrated Information

The above figure displays an example of customer information integrated using this method. Users can create, read, update, and delete in the main customer repository, and it is automatically sent to all of the other databases. This method does not follow the business process when building the integrations. Business-critical integrity constraints still need to be built to ensure information is only ever entered into the customer repository, otherwise the information will become out-of-sync.