Foundations of Business Intelligence : Databases and Information Management

An effective information system provides users with accurate, timely, and relevant information system.

Accurate = free of errors.

Timely = when it is available to decision makers when it is needed.

Relevant = when it is useful and appropriate for the types of work and decision that require it.

File Organization Terms and Concepts

A computer system organizes data in a hierarchy that starts with the bit, which represents either a 0 or a 1.
Bits can be grouped to form a byte to represent one character, number or symbol.
Bytes can be grouped to form a field, and related fields can be grouped to form a record.
Related records can be collected to form a file, and related files can be organized into a database.

The use of traditional approach to file processing encourages each functional area in a corporation to develop specialized applications.
Each application requires a unique data file that is likely to be a subset of the master file.
These subsets of the master file lead to data redundancy and inconsistency, processing inflexibility, and wasted storage resources.

Data redundancy = the presence of duplicate data in multiple data files so that the same data are stored in more than one place or location.

Data inconsistency = the same attribute may have different values.

Database Management System (DBMS)

Database = a collection of data organized to serve many applications efficiently by centralizing the data and controlling redundant data.

Database management system (DBMS) = software that permits an organization to centralize data, manage them efficiently, and provide access to the stored data by application programs.

One record would be one student and their name, address, phone number and etc. 
Therefore, a database would be a collection of records (or students).

Key services provided by the DBMS are:

1. storage of data
2. retrieval of data
3. sort of data (into useful information)
4. management reports
5. answer management questions (queries)

Advantages of Database Management Systems (DBMS)

1. Easy to sort
2. Easy to ask repetitive questions (called a query)
3. Provides formatted input screens to prevent errors (called forms)
4. Can produce formatted output (called reports)
5. Reduces data redundancy (less duplication of data)
6. Increases data integrity (data is valid more then in a spreadsheet)

Relational databases = represent data as two-dimensional tables. 

Tables may be referred to as files. Each table contains data on an entity and its attributes. MySQL is a popular open source DBMS, and Oracle Database Lite is a DBMS for mobile computing devices.  

The Three Basic Operations Of A Relational DBMS

Capabilities of Database Management System 

Data definition = to specify the structure of the content of the database

Data dictionary = an automated or manual file that stores definitions of data elements and their characteristics