Information Systems and Databases
Information systems are computer systems that support end users, giving them access to the information. For a large number of information systems, the data is held in databases and access is via database management systems. Information systems perform a variety of tasks and these are considered in the following topics in the HSC course. While all of the information processes are represented in information systems, the emphasis in this topic is on the processes of organising, storing and retrieving with database systems and hypermedia.
Information systems: organise data into information enable the analysis of information to produce knowledge
Different types of information systems serve different purposes. Information systems may be used to: process transactions provide users with information about an organisation help decision-making manage information used within an organisation
Examples of database information systems include: school databases that hold information on: teachers subjects classrooms students the Roads and Traffic Authority which holds information on: automobiles holders of drivers licences video stores that hold information on: borrowers videos
Organisation methods
Non-computer methods of organising include: telephone books card based applications
Computer-based methods of organising, include: flat-file systems database management systems hypermedia There are advantages and disadvantages of computer based and non-computer based organisation methods. The wise student will select the most appropriate system for the particular purpose.
Flat-file databases are based on the logical organisation of: files records fields, key fields characters Relational databases are based on the logical organisation of: schemas which consist of: entities attributes relationships tables which consist of entities which have attributes records views of the data for different purposes
Databases are organised using data modelling tools. data dictionaries describe the characteristics of the data: size type purpose schematic diagrams show the relationships between entities normalising data reduces data redundancy
Hypertext and hypermedia have a logical organisation that consists of: nodes and links uniform resource locators metadata (data about data), such as HTML tags
Hypermedia is organised using the tools of: story boards to represent data organised using hyperlinks HTML software that allows text, graphics and sounds to be hyperlinked
Storage and retrieval
Database management systems (DBMS) are involved in the process of storage and