AFM241 Study Guide - Final Guide: Database Theory, Relational Database Management System, Decision Support System
30 May 2018
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o In case of any raw material, it is often worth very little until it is processed into
something of value
• Data processing can yield information in many forms – such as summary tables, bar
graphs, and pie charts, plot points etc.
o Graphical representations of data are in fact the basis for idea formation in
many situations
5.2 Relationship Databases
• Databases are designed to perform specific functions – there are different kinds of
databases
• Two most common databases are production and decision support system
databases
o Production database is used mainly to track data about frequent and complex
transactions
o Each transaction involves one or multiple actions related to reading from or
writing to a database
E.g. when BlueBikes purchases a bike from one of its suppliers on credit,
accounts payable will have to be updated to reflect the amount
outstanding and inventory account will be updated as well
• A decision support system (DSS) is more complicated
o Compared to production database, it offers more extensive information
generation and processing as well as management capabilities
o DSS database focuses on information requirements instead of transaction
requirements characteristic of production capabilities
o Most popular DSS databases are called datawarehouses – storage facilities
dedicated to processing existing data taken from production databases into
useful information
Tend to be updated rather infrequently compared to production
databases – lower volume of transactions to record
When data updates do occur, they are usually very significant
• When data is stored in a database, it is organized in certain ways that makes accessing
and sifting through it easier
o Data about the data is also stored in the database – this is metadata which is
kept in a data dictionary
o A data dictionary is a compilation of all the components of the data, their
names, their characteristics and also facts about the nature of relationships
between the different sets of data
• A program that manages all this data and metadata is called Database Management
System (DBMS)
• DBMS performs the following functions:
o Manages metadata in a data dictionary
o Produces complex data storage functions, including enforcing data input
requirements
o Creates and enforces a secure environment for the storage of data
o Manages the complex needs of a multi-user environment
o Enforces data integrity at all levels of the database
• Four different database models/applications:
1. Hierarchical
2. Network
3. Relational
4. Object-oriented
• The most prevalent is the relational database, implemented in the form of a
Relational Database Management System (RDBMS)
o Most common example of RDBMS is Microsoft Access (single users), Oracle,
DB2 (IBM), Microsoft SQL, MySQL
