Information Systems and data Bases

Information systems and databases Information systems

Characteristics of information systems

The creation of information from data is called information processing, data processing or electronic data processing. Data are raw facts and information is data organised in a way that gives the data meaning.

The characteristics of information systems are that they:

• Organise data to give information
• Analyse information to give knowledge.

Types of purposes of information system

Information systems can be described as:

• Transaction processing systems – to record organisations activities.
• Management information systems – to produce reports about the organisation.
• Decision support systems – to plan for the future of the organisation
• Office automation systems – to manage the information used in an organisation.

Examples of database information systems

School Database information system

Environment

The Environment of a school database information system would include:

• The school community
• The educational services
• The hardware and software

Purpose

The purpose of a school database administration system is to maintain the efficient operation of the school, its personnel, finances, resources and administrative tasks.

Data/Information

Data could include:

• Equipment register
• Finance and purchase orders
• GST records
• Student marks and grades
• Student personal and academic information

Participants

Participants are those people who directly use the information system. Everyone involved in a school is likely to be a system participant at some stage.

IT

Most data entry and access in a school information system is through the keyboard and monitor. Typical hard copy outputs include class lists, daily absentee lists, order forms and financial statements.

Basic data organisation methods

Manual organising methods

Manual information systems have been in use for millennia.

Manual information systems often need duplicate sets of all the data.

Computer-based organising methods

Computerised information systems provide greater flexibility.

Flat file database management systems

Flat file database management systems are the easiest to learn and use.

Relational database management systems

DBMS is the standard abbreviation for a database management system.

Hypermedia systems

Hypermedia is any display object that will link you to new information. Hypertext is a ‘text only’ form of hypermedia.

Organisation of data in databases

The logical organisation of a flat file database

The structure of a flat file database is:

• Database
• File
• Record
• Field, key field
• Character

An entity is a specific thing about which an information system collects and processes data. In a database of students, each student is an entity.

The key field contains data that is unique to each record. It is like a ‘fingerprint’ that identifies each record in a database.

The logical organisation of a relational database

A relationship is a table or file created by joining together data from different databases.

An attribute is a field copied from a parent database. Attributes are the columns in a relationship table shown in list view.

A calculated field is a field that is created by a calculation using data taken from other fields.

Records in a relationship are sometimes called ‘tuples’.

Relationships can be saved as new database files.