IPT Notes Backup {2010}

GLOSSARY

Word	Definition
TPS	An information system that collects, stores, modifies and retrieves the daily transactions of an organisation
Controlled Process	A controlled process is a process that must support an organisations operations
Rapid response	The turn around time from the input of the transaction to the production of the output.
Batch processing	A Transaction Processing method that collect transaction data as a group, or batch and process it later
Real-time processing	A TP method that processes data immediately
Concurrency	A property of a transaction processing system that ensures two users cannot change the same data at the same time
Atomicity	A property of a TPS that ensure that all of the steps involved in a transaction are completed successfully as a group
TPM	Software that allows transaction processing application programs to run efficiently
Data validation	The checking of the accuracy of the data before it is processed into information
Manual transaction (MTS)	Business systems that operate without the use of machines
Users	Pinky is an idiot. Users are people who use the system directly
Participants	People who use the system indirectly
Reservation systems	They are used to set aside certain items for a product of a customer to use at a future time
POS terminal	They send inventory data to a central computer when the sale is made
EFTPOS	Electronic Funds Transfer At Point Of Sale. A way of paying for things electronically
Library loan system	Used to keep track of items borrowed from the library
Database	An organised collection of data
Hierarchical Database	Data organised in a series of levels
Network D/B	Organises data as a series of nodes linked by branches
Good data placement	A database that is designed to access patterns of data and to place frequently accessed data together
Short transaction	Self explanatory
Real-time backup	Processing that is characterised by continuous operations with downtime kept to a minimum.
High normalisation	Redundant information that is kept to a minimum whenever possible to increase the speed of updates
Historical data	Data that is rarely referenced into a separate database
Master file	Contains information about an organisations business situation.
Transaction file	A collection of transaction records.
Work file	A temporary file in the system used during the processing
Program file	Contains instructions for the processing of data.
Consolidated	Data that is organised using consistent naming conventions, measurements, attributes and semantics
Subject oriented data	A large amount of data stored across an organisation.
Read only data	Data that has been moved to the data warehouse and cannot be changed unless the data was correctly
Backup	Another copy of the data that could be used to rebuild the system
Journal	A journal maintains an audit trail of transactions and database changes.
Checkpoint	A suspension of all processing to synchronise its files and journals. All transactions in progress are completed, and the journal entries are updated. The DBMS then writes a special record to the transaction file. This record is called the ‘checkpoint record’
Recovery manager	A program that restores the database to a correct condition and restarts the transaction processing
Backward recovery	Used to back out or undo unwanted changes to the database.
Forward recovery	Starts with a backup copy of the database.
Magnetic tape	Magnetic tape is often used as a backup medium. It is a very long, thin strip of plastic coated with a thin layer of magnetic material
Sequential access	This is a form of access that starts at the beginning of the tape and reads from one reel to another
Grandfather-father-son backup	This is a backup procedure that refers to at least three generations of backup master files. The most recent backup is the son, the second last is the father, and the oldest is the grandfather
Partial backup	Partial backups occur when only parts of the master file backup.
Direct access	Direct access occurs when data is accessed without accessing previous data items.
MICR	Magnetic Ink Character Recognition systems are used to read account numbers on cheques.
ATM	Automatic Teller Machines are used for common banking transactions
Barcode reader	Used in retail industries at point of sale to collect product information.
On screen forms	On-screen forms are created for computerised data entry purposes to populate fields in a database.
Web forms	Used by users that wish to purchase items over the internet
DSS	Used to assist people in making decisions and providing information, models and analysis tubes.
Data mining	Used to find relationships and patters in the data stored in a database
Automation of jobs	The use of information technology to perform tasks once performed by people.
Bias	Data that is unfairly skewed or gives too much weight to a particular result
Data security	The use of a series of safeguards to protect the data
Data accuracy	The extent to which data is free from errors
Data integrity	The reliability of data. Involves the accuracy, currency, and relevance of data
Downtime	The total period that a service or component is not operational within an agreed service time

INFORMATION SYSTEMS AND DATABASES

Information systems:
Information systems perform a set of information processes requiring participants,
data/information and IT.
Created to provide access to information for an organisation or individual.
Data is head in a database and access is achieved using a DBMS.
Characteristics of information systems:
− Organisation of data into information.
− Analysing the information to give knowledge.

Purpose of information systems:
Transaction
processing
systems [TPSs]
Collect, store, modify and retrieve the daily transactions of an organisation.
− Batch processing collects the transaction data and processes it later.
− Real-time processing is processed immediately.
Examples: POS terminal, processing credit card payments, tracking receipts of
materials from suppliers.
Decision support
systems [DSSs]
Assist people to make decisions by providing information, models and analysis
tools.
Examples: system that analyses the stock market and helps the user to make
decisions about buying and selling shares.
Expert systems Provide information and solve problems that would otherwise require a person
experienced in that field. It asks a number of questions and compares their
answers to a knowledge base
Examples: system that help doctors diagnose infectious blood diseases and
prescribe antibiotics. Patient’s medical details are compared to its knowledge
base.
Solutions are not always correct, up to the user to accept or reject solution.
Management
information
systems [MISs]
Provide information for the organisation’s managers. Presents basic facts about
the performance of the organisation.
Examples: Execute Information Systems (EIS) provides information on
strategic issues.
Office
automation
systems
Provide people with effective ways to complete administrative tasks in an
organisation. Uses a range of software and communication technology.

Examples of database information systems
Information systems that uses a database. Databases are accessed by a database management
system [DBMS]. INFORMATION SYSTEMS AND DATABASES
• School database: information about teachers, students, classrooms and subjects.

Environment

− The school community (students, staff, parents)
− The educational services offered by the school/
− The flow of information between the school and authorities.
− The hardware and software.
− Any organisation, business or individual that receives information generated by the
school database administration systems or supplies data for the system.
Purpose
− To maintain the efficient operation of the school, its personnel, fiancés, resources and
administrative tasks.
− To provide information on student enrolments, subject selections and assessments for
both school staff and educational authorities.
Data / information
Information on people, resources and processes eg…
− Equipment registers; Finance and purchase orders; GST records; Library resources and
loans; Staff information; Student marks and grades; Student personal and academic
information; Timetables and room allocations.
− Most data stored on an administration computer network in the school office and library
and some on individual staffroom computers.
Participants
− School office and library staff who use the system.
− Teachers who add class information into the system.
− Students who search the library catalogue.
− Everyone in the school is likely to be a system participant at some stage.
Information Processes
C O A S P T D
− Collecting: through enrolment forms, marking of class rolls, payment of fess, recording
results in class mark books, library loans and returns and administrative tasks.
− Organising and storing: a number of different databases that deal with student and
staff information, resources of various types and finances.
− Analysing and processing: creating class lists, student reports, financial reports,
purchase orders, receipts and over due book lists.
− Transmitting and receiving: some data are transmitted to and received from
educational authorities e.g. BOS.
− Displaying: input and output data are displayed on VDUs and printouts.
Information
Technology
− Computers (data entry, access and in staffrooms)
− Barcodes readers (library loans and returns).
− A student inquiry and loan/circulation network.
− Software: OASIS office network administration system, motorised mark book,
spreadsheet application.
INFORMATION SYSTEMS AND DATABASES
• RTA: information on automobiles.

Environment

− All drivers, driving instructors, driver examiners.
− Vehicle owners, vehicle inspectors.
− RTA services eg registration and licensing.
− Flow of information between the RTA and the NSW Department of Transport.
− Police and courts
− Hardware and software.
Purpose
− To manage the registration all the drivers and motor vehicles in NSW.
− To send out vehicle registration payments requests.
− To provide statistical information on drivers and vehicles to the government and
registration information to other authorities.
Data / information
− Driver personal details, payment details.
− Driver licence number, license type and classification, driving history.
− Vehicle identification number, make and model.
− Vehicle owner details, registration number, payment details.
− Vehicle inspection record, insurance details; GST records.
All available to authorise RTA employees at any motor registry and vehicle inspection
station anywhere in the state.
Participants
− Data entry operators, inspectors, counter staff and administration officers at RTA
offices.
− Motor registries and motor vehicle inspection stations.
− Police Department Traffic Branch.
Information Processes
C O A S P T D
− Collecting: through registration application forms, licence applications, renewals,
vehicle inspection and driving test results.
− Organising and storing: a number of different databases that deal with drivers,
vehicle information and finances.
− Analysing: producing statistics on registered vehicles and licensed drivers.
− Processing: vehicle registration and licence renewal forms are sent out.
− Transmitting and receiving: data on vehicles and drivers are transmitted to the Police
and other authorities when requires.
− Displaying: input and output data are displayed on VDUs and printouts.
Information
Technology
− Computers – keyboards and monitors (data entry and display terminals)
− EFTPOS machines (credit / debit card payments)
− Barcode scanners (registration notice payments).
− Networking between the computers (in office / building and links to a state WAN) INFORMATION SYSTEMS AND DATABASES
• Video stores: information on borrowers and videos

Environment

− Customers and staff
− Suppliers
− Entertainment and other services supplied by the store.
− The flow of information between the store and its head office.
− Hardware and software.
Purp
ose
− To keep accurate records of the stock (rental and sales).
− To collect data for further analysis by store management.
Data / information
− Customer details (current loans and overdue items).
− Video rental title records (items in stock and on loan)
− Saleable items records (videos, snack foods).
− Rental and/or sale figures for each item.
− GST records.
Most available to store staff, some may be available to customers through inquiry
terminals.
Participants
− Staff who check out videos and other products
− Staff who process returns.
− Staff who authorise orders for new stock.
− Head managers who use the data provided by the system for inclusion management
and planning reports.
Information Processes
C O A S P T D
− Collecting: through membership applications, sale items and rental videos passed
over the scanner, and new products that arrive at the store.
− Organising and storing: in product and customer databases.
− Analysing: producing statistics on video rentals, sales, delinquency rates (non-return
of videos) and store income.
− Processing: products are sold, rented, returned or arrive as new products. Video
rental or return, customer’s record is updated.
− Transmitting and receiving: all data is transmitted to the head office.
− Displaying: input and output data are displayed on VDUs and printouts.
Information
Technology
− Computers – keyboards and monitors (enter details of a new rental customer)
− Barcode scanners (database input devices).
− WAN link from the head office (to update database when there’s new video rental
titles).
− Customer inquiry terminals – touch screen and web like interfaces.
− Database management and sakes software.
− Network communication software. INFORMATION SYSTEMS AND DATABASES
Organisation methods
Process of arranging, representing and formatting data.
Database: an organised collection of data.
Non-Computer Methods:
− Telephone book
− Dictionary
− Recipe book
Computer-based Methods:
− Flat-file systems
− Database management systems
− Hypermedia
May be sorted: Alphabetically; numerically; chronologically; By Category, etc.
Non-computer and computer-based methods:
Computer based methods Non-computer based methods
− Easily edited.
− Large storage.
− Fast retrieval.
− Display options.
− Easily searched through.
− Many people can access it at once.
− Backup storage can be easily kept.
− Access to data can be restricted
− Sorting of data is flexible over a range of
fields
− Convenient to obtain information.
− Easily, inexpensively organise data.
− Do not need a computer or computer skills.
− Easier to keep secure therefore, remain more
private.
− Data is more difficult to use for other
purposes.

Databases
Database: a large storage of information. As an information system, a database allows the
effective manipulation of information it contains through a Data Management System (DBMS).
File: A block of data. A file in a database is divided into a set of related records.
Record: Collection of facts about one specific entry in a database. A record is divided into one or
more related fields.
Field: Specific category of data in a database. Data items in a field are made up of characters.
Character: Smallest unit of data people can use e.g. letters, numbers and special symbols.
Key: Fields that are used to sort and retrieve information. Usually, each key holds a unique item
that applies to only one record. Key is used when records are sorted, not all data has to be read
or retrieved.
− Primary key: a single or compound key that must have a value cannot be empty.
− Secondary key: a field that contains useful items of data often used in searches, not always
unique.
Types of keys
− Foreign key: an attribute of a table that is a primary key of another table. INFORMATION SYSTEMS AND DATABASES
Flat-file databases:
- Organises data into a single table.
- Simple to create and organize
- Inexpensive
- Data for the whole database is contained in
a single file
- Managed by programs called file managers
- Consists of fields, records and files
- High level of data redundancy
- Access is often sequential, slower access




Relational databases:
- Organises data using a series of related
tables.
- Provide a method of storing data based on
multiple databases linked together by
common keys. The keys provide the facility
to build up huge databases without necessary
duplicating information (data redundancy) –
the data is shared.
- Draws information from one or more
additional files as well as the current file
- Needs a Primary Key / Link (Unique key
field)
- Organisation of data involves a schema.

Relationships are built between the tables of the relational database to provide a flexible way of
manipulating and combing data.

Schema
- A data definition for a database.
- An organised plan of the entire database, showing how and where the data is found, description
of the data, data’s logical relationships.

Relational database: defines the entities, attributes and relationships.
Entity: A specific thing about which information is collected and stored.
Attribute: Defined property of an entity (fields).
Relationship: The way the entities related to each other. There are three ways:

Types of relationships
One-to one: when each record in the first entity is related to exactly one record in the sconed
entity.
One-to-many: when one record in the first entity is related to many records in the second entity,
but any record in the second entity only relates to one record in the first entity.
Many-to-many: when each record in the first entity is related to many records in the second
entity, and each entity in the second entity is related to many records in the first entity.

INFORMATION SYSTEMS AND DATABASES
Views of data for different purposes:
• Tables: an organisation of data into columns (attributes) and rows (tuples).
• Forms: used to view, enter and change data in a table.

Data modelling
Process of identifying entities, the relationships between those entities and the attributes of those
entities. Used to develop a schema for the database.

Data dictionaries: a comprehensive description of each field (attribute) in the database. It
contains information about the characteristics of each item entered in the database eg field name,
field size, data type and field description.

Field name Name of the field, e.g. surname
Data type kind of data that can be stored in the field
Alphanumeric data: alphabet, numbers and symbols.
Numeric data: numbers and numerically related symbols.
Boolean or logical data: composed of true / false or yes / no.
Data date: displayed as dd / mm / yy or mm / dd / yy.
Time date: in the form hh / mm.
Field size Number of characters allowed in each field, e.g. 50
Description Specifies the contents of the field, e.g. surname of student

A data dictionary consists of metadata – data about data. Provides a common ground for people
working on a project at the same time. This reduces data redundancy – the undesirable
duplication of data within a database.

Schematic Diagrams:
Graphical tools that help define the database. A common schematic diagram is an entity-
relationship diagram [ERD]; it’s a graphical method of identifying the entities and showing the
relationships between them, helps to determine the data to be included and excluded from the
database.

Normalisation:
Process of studying the conceptual schema for a database and organising it into a group of tables
in the most efficient way, that is, the production of a relational schema which minimizes data
redundancy.
The degree of normalisation has been defined in terms of forms such as: INFORMATION SYSTEMS AND DATABASES

- First Norm First [1NF]: (basic level of normalisation) moving data items into separate tables
where the data in each table is a similar type.
- Domain/key normal form [DKNF]: (final level of normalisation) a key uniquely identifies each
row in a table. A domain is set of permissible values for each attribute.

Hypermedia and Hypertext:
Hypermedia is the storage of information using a set of documents that may contain text,
numbers images, audio and video. Each document is independent and information is retrieved
using hypertext.
Hypertext: a system where documents can be cross-linked in such a way that you can navigate
from one document to the next by clicking on a link. A link / hyperlink allows the electronic
connection.
Node: a computer that has the destination of the link.

Links
Links between nodes in a hyper document have no structure. They are associated with anchors
and bookmarks – smaller parts of the nodes.

Uniform resource locator [URL]
Address of a file or resource on the Web.
http://www.smh.com.au/crossword.html


Parts of the URL:
- Protocol: transfer method used to access a particular resource on the Web ‘http://’ [hypertext
transfer protocol].
- Domain name: address of the specific computer where resource is located (can be replaced by
IP number).
- File path: the full path to the file to be retrieved.

HTML [hypertext mark-up language]:
A set of special instructions that indicate how parts of document will be displayed and navigated.
Viewed in a web browser. HTML editor specialises in writing HTML code. HTML tags are metadata
(information about data).

Protocol Domain name File Path INFORMATION SYSTEMS AND DATABASES
Tools for organising hypermedia:
Storyboard: a series of frames, each representing a different action or screen image. Used to
organise hypermedia. Consists of navigation paths, information and graphics. Popular because
simple to construct, easy to read and can be modified at every stage.
Layouts:
− Linear: sequential path.
− Hierarchical: sequential path in top-down design.
− Non-linear: no structure.
− Combination: a blending of the layouts above.

Web page creation software: allows the creating of web pages without having to use HTML.
The required HTML tags are inserted automatically by the software. Web pages can be viewed in
HTML form or seen on the web browser.

Storage and retrieval
Database management system: application software that allows the entry, manipulation and
storage of data in a database format. Used for secure and efficient storage and retrieval of
information of a database.
- Reduces data redundancy
- Backup and recovery capabilities

Methods of accessing data
Sequential access - Data is accessed in a sequence. Accesses data in the order it was stored.
Does not require the exact location of the data item, and it’s much slower than direct access.
Example: accessing data stored on magnetic tape.
Direct access - Data is access without accessing previous data items. Data is stored in a
particular storage location based on algorithm. Algorithm is used to calculate the approximate
location of the data – if data not found at this location, computer searches through successive
locations until data is accessed.
Indexed access: when direct access involves the use of an index (a table that has information
about the location of the data). Data is accessed by referring to the index and obtaining its exact
location. Requires more processing time to search the index and to maintain the index.
Example: storing data on a disk and the logical location of data within a database.



INFORMATION SYSTEMS AND DATABASES
Storage mediums:
- Magnetic tape: store large amount of data inexpensively, used for backup. Uses sequential
access – all bits of data are organised in a strict sequence. Erasable, reusable and durable way of
storing data
- Removable cartridge: a HDD encased in a cartridge. Fast, not as fast as HDD, use direct
access. E.g. Zip disks 100-250Mb, Jaz disks 2 GB.
- Hard disk: uses direct access.
- Optical disc: data is read and written using laser technology, uses direct access. Eg CDs
650mb, DVD 4.7 GB – 17Gb. Writable CDs have an extra, non-reflective layer that the laser can
modify.

Encryption and decryption:
− Process of encoding data, involving manipulations of bit patterns.
− Decryption: process of decoding.
− Most effective way to achieve data security during data transmission.
− Data encoded
transmitted
data decoded.
− Problem: to find a method that is difficult to decode but also practical to use.

Asymmetric encryption: requires a public key for encryption (before transmission) and a
private key for decryption (received message).
Types of
encryption
Symmetric encryption: requires the same key for encryption and decryption e.g. Data
Encryption Standard [DES].

• Selecting data from a relational database using SQL commands:
Query: search of a database for records that meet a certain condition.
Constructed form: .
Method for constructing a query is query by example [QBE]: requires user to enter the criteria
against a field.
Relational query: search of a database involves two or more entities.
Operators
Relational operators: (= , <> , < , > , <= , >=) indicates relationship between two
expressions.
Wildcard characters: (* number of characters, ? one character) represent unknown characters.
Logical operators: used to combine queries so that a search is carried out on one or more fields.
- AND: requires both first and second query to be true.
- OR: requires either the first or the second query to be true.
- NOT: exact opposite. INFORMATION SYSTEMS AND DATABASES
Structure Query Language [SQL]
Query language: specialised language designed to search a database.
SQL: a query language used to access and manipulate data in a relational database. Variations to
SQL are developed by specific DBMSs eg ANSI SQL, standard SQL.
SQL statements contain keywords that are used to perform a particular task.
Must use correct syntax: keywords – uppercase, fields separated by commas, entity and attribute
are separated by full stop, search criteria or data item enclosed in double quotes.

Keyword Values Description
SELECT Field(s) Data to be displayed.
FROM Table(s) Source of data.
WHERE Criteria Query.
ORDER BY Field(s) Order in which fields to be displayed.

Tools for hypermedia search and retrieval:
Retrieving data in hypermedia involves using search engines.
Search engines: database of indexed websites that can be searched using keywords.
Works by sending out a search robot, crawler or spider to fetch as many documents as possible.
Another program, called an indexer, then reads these documents and creates an index based on
the words contained in each document.
Directories: lists of Web sites organised into categories.
Search robot: program that access Web sties and gathers information for search engine indexes.

Other information processes
A report is the formatted and organized presentation of data.
A form is used to enter, view and edit data.

Reporting on relevant information in a database:
Report: formatted and organised presentation of data eg mailing labels, invoices, sales
summaries and telephone lists.

Issues related to information systems and databases
Privacy & Security:
Database systems usually have security measures in place to prevent both unauthorised access to
the system and corruption of the data stored. This introduces the concern about security.
− Data may get into the wrong hands. May become damaged or deleted accidentally or
intentionally. INFORMATION SYSTEMS AND DATABASES
− Incorrect data may be entered.
− Validation of data:
- Format of data
- Accuracy of data and reliability of sources. Data is protected by copyright regardless of
where it is obtained. Data should be acknowledged or permission sought from the owner
before the information can be used in publication.
− Ownership and control of data is an ethical issue
− Restrictions on the level of access – password protection: personal objects, biometric devices.
Data encryption and firewall (used on the Internet or network to verify and authenticate all
incoming data).
− Closed circuits. Monitoring by camera and logs.
− Data encryption.
− Dial back modems to registered phone numbers.
− Backup of data.
− Firewalls and Virus Protection.

Accuracy of data and the reliability of data sources:
Data integrity can be maintained by ensuring that the database is able to resist:
− User mistakes.
− System malfunctions.
− Deliberate or accidental alteration.
Data validation checks the accuracy and appropriateness at the data entry stage.
Data bias occurs in the way the data is collected, captured and manipulated.
Data captures in a machine readable form will less likely be biased
Data transcribed by the operator from a non-machine readable form will like be biased.
Rejection and editing of some collected data can cause data to be biased and unreliable.
Access to data, ownership and control of data:
Freedom of Information Act 1982:
The rights of individuals to privacy and control of information concerning personal details need to
be considered. However the existence of a store of information concerning individuals can, in
some cases, be beneficial to society in general.
− Unwanted names on mailing list
− The sale of mailing lists
− Loss of control of information
− Information on individuals needs to be accurate
− Surveillance information held on computers controlled by government agencies
− Tracing missing persons INFORMATION SYSTEMS AND DATABASES
− Assistance in the apprehension of tax evaders
− Assistance on the apprehension of social security benefit cheats
− Ability to determine bad creditors
− Availability of research data
− Emergency access to medical records
− Monitoring of visits to doctors.

Data warehousing and data mining:
Data warehousing: collection of data designed to support management decision-making.
Development of data warehouse includes development of systems to extract data from operating
systems plus installation of a warehouse database system that provides managers flexible access
to the data.
Data mining: use of software that looks for hidden patterns in warehoused data.