Chapter 14

Chapter 14

Enterprise Computing

Enterprise computing involves the use of computers in networks, such as LANs and WANs, or a series of interconnected networks that encompass a variety of different operating systems, protocols, and network architectures

Types of enterprises:

1. Retail.
2. Manufacturing.
3. Service.
4. Wholesale.
5. Government.
6. Educational.
7. Transportation.

The common categories in an enterprise are:

1) Executive management.

2) Middle management.

3) Operational management.

4) Non-management employess.

Enterprise information is the information gathered in the ongoing operations of an enterprise-sized organization

• Business intelligence

• Business process management

• Business process automation

Managers coordinate resources by performing four activities

Planning > Organizing> Leading> Controlling> Planning

Information Systems in the Enterprise

An information system is a set of hardware, software, data, people, and procedures that work together to produce information

• Accounting and Finance

1)-Accounting software manages the everyday transaction.

2)-Billing software helps the company reconcile purchases with customer payments.

3)-The financial software helps managers budget, forecast, and analyze.

• Human Resources

1)-Human resources information system (HRIS) manages one or more human resources functions.

2)-Employee relationship management systems manage communication between employees and the  business.

• Engineering or Product Development

1)-Computer-aided design (CAD) uses a computer and special software to aid in engineering,                  drafting,  and design.

2)-Computer-aided engineering (CAE) uses computers to test product designs

• Manufacturing

1)-Computer-aided manufacturing (CAM) is the use of computers to control production equipment.

2)-Computer-integrated manufacturing (CIM) uses the computer to integrated the many different              operations of the manufacturing process.

3)-Material Requirements Planning (MRP) uses software to help monitor and control processes               related to production.

4)-Manufacturing Resource Planning II (MRP II) is an extension of MRP and also includes software       helps in scheduling

5)-Quality control system helps an organization maintain or improve the quality of its products or           services.

Marketing-Marketing information system serves as a central repository for the tasks of a marketing                     department.
Sales-Sales force automation (SFA) software equips traveling salespeople with the electronic tools they need to be more productive.
Distribution-Distribution system provide forecasting for inventory control, manage and track shipping of products and provide information and analysis on inventory in a warehouse.
Customer service-Customer interaction management (CIM) software manages the day-to-day interactions with customers.
Information Technology

• Information Technology

-Makes technology decisions for the enterprise in the case like whether to build or buy new information system and when a computer or information system has outlived its useful life.

-Web Site Management Programs- collect data designed to help organizations make informed decisions regarding their Web presence.

-Office Information System (OIS)- oriented to word processing, electronic mail, and other similar office functions.

-Transaction Processing System (TPS)- for business transactions involving the collection, modification, and retrieval of all transaction data.

-Management Information System (MIS)- focuses on management of information systems to provide efficiency and effectiveness of strategic decision making.

-Decision Support System (DSS)- a set of related computer programs and data required to assists with analysis and decision making within an organization.

-Expert System- a piece of software programmed using artificial intelligence. It uses the database of expert knowledge to offer advice or make the decision. For example, it is the help button found in our operating system.

-Integrated Information System (IIS)- an array of multiple information sets linked together in an organized way. This contains three processes:

• Customer relationship management manages information about customers, interactions with  customers, past purchases, and interests.
• Enterprise resource planning provides centralized, integrated software to help manage and  coordinate ongoing activities.
• Content management systems are information systems that combine database, software, and  procedures.

Technologies used in enterprise:

• Portals- a collection of links, content and services presented on a Web page that are interesting for a particular job function/

•  Data Warehouse- a huge database that stores and manages the data required to analyse historical and current transactions.

• Electronic Data Interchange (EDI)- a set of standards that control the transfer of business data and information among computers both within and among enterprise.

• Extranet- a portion of a company's network that allows customers or suppliers of a company to access parts of an enterprise's intranet.

• Web Services- allow businesses to create products and B2B interactions over the Internet.

• Document Management System (DMS)- allows for storage and management of a company's documents.

• Workflow- a defined process that identifies the specific set of steps involved in completing a particular project or business process.

• Virtual Private Network- allow customers or vendors to connect to company network server in a private network connection.

Virtualisation- practice of sharing or pooling computing resources.

A) Server virtualisation- physical server can be divided into many virtual servers.

B) Storage virtualisation- single logical storage device can be created from many physical storage devices.

Cloud computing- an Internet service that provides computing needs to computer users.

A) Grid computing- combines many servers and/or personal computers on a network to act as one large computer.

Enterprise Hardware

• Enterprise hardware allows large organizations to manage and store information and data using devices geared for:

1. Heavy use
2. Maximum availability
3. Maximum efficiency

• RAID duplicates data and implements duplication in different ways
• Network attached storage (NAS) is a server that provides storage to users and information systems attached to the network
• A storage area network (SAN) is a high-speed network that provides storage to other servers to which it is attached
• An enterprise storage system is a strategy that focuses on the availability, protection, organization, and backup of storage in a company
• Goal is to consolidate storage
• A blade server packs a complete computer server on a single card (called a blade) rather than a system unit
• The individual blades insert in a blade server chassis
• A thin client is a small terminal-like computer that mostly relies on a server for data storage and processing
• The processing for a thin client usually is done on a server

High availability system- continues running and performing tasks for at least 99 percent of the time. It include hot-swapping and redundant components.

Scalability- measures of how well a computer hardware, software or an information system can grow to meet increasing performance demands.

Interoperability- ability for an information system to share information with other information systems within an enterprise.

Types of backup methods:

1) Full- fastest recovery method. All files are saved. Disadvantage is longest backup time.

2) Differential- fast backup method and require minimal storage. Disadvantage is recovery is time consuming because the last full backup plus differential backup are needed.

3) Incremental- fastest backup method and require minimal storage. Only most recent changes saved. Disadvantage is recovery is most time consuming because the last full backup and all incremental backups since the last full backup are needed.

4) Selective- fast backup method which provide great flexibility. Disadvantage is difficult to mange individual file backups.

5) Continuous- the only real time backup and recovery of data is very fast. Disadvantage is very expensive and requires a great amount of storage.

Disaster recovery plan- a written plan describing the steps a company would take to restore computer operations in the event of a disaster. Contains four major components which are Emergency plan, Backup plan, Recovery plan and Test plan.

Chapter 13

Chapter 13
Computer Programs and Programming Languages

Types of programming languages and tools
-Machine language is the first generation of programming languages, this language is only recognized by the computer.
-Assembly language is the second generation of programming languages. use of symbolic instructions.
-Source program contains the code to be converted to machine language.

-Procedural language instructions that tell the computer what and how to do.
Third generation language is a compiler translates an entire program before executing it and an interpreter converts and executes one code statement at a time.

• C programming language used to write many of today's programs
• COBOL (common business oriented language) designed for business application with easy to read English like a statement.

Object-Oriented Programming Languages and Program Development Tools

An object-oriented programming (OOP) language allows programmers the ability to reuse and modify existing objects

Other advantages include:

• Object can be reused
• Programmers create applications faster
• Work well in a RAD environment
• Most program development tools are IDEs

-Java is an object-oriented programming language developed by sun microsystem. just in time (JIT) compiler converts byte code into machine dependent code.

-Microsoft is the NET framework allows almost any type of program to run on the internet or an internal business network. Features include CLR (common language runtime) and classes.

-C++ is an extension of the c programming language.

-C# is based on C++ and was developed by Microsoft.

-F# combines the benefits of an object-oriented language with those of a functional language.

-Visual Studio is Microsoft’s suite of program development tools:

-Visual Basic is based on the BASIC programming language

-Visual C++ is based on C++

-Visual C# combines the programming elements of C++ with an easier, rapid-development e-      environment]

-A visual programming language is a language that uses a visual or graphical interface for creating all source code.

-Borland’s Delphi is a powerful program development tool that is ideal for building large-scale enterprise and Web applications in a RAD environment.

-PowerBuilder is a powerful program development RAD tool.

-Best suited for Web-based,NET, and large-scale enterprise object-oriented applications. 

-Application generator is a program that creates source code or machine code from a specification of the required functionality.

-Macro is a series of statements that instructs an application how to complete a task that can be created in two ways record the macro with macro recorder and write the macro.

Web page development:

-HTML is a special formatting language that programmers use to format documents for display on the web.
-XHTML is a markup language that allows websites to be displayed more easily on mobile devices.
-XML allows web developers to create customized tags and use predefined tags to display content appropriately on various devices. Applications of XML are RSS 2.0 and ATOM.
-WML s a subset of XML and is used to design pages for microbrowsers.
-CGI (common gate interface) used to send and receive information between the computer and a web server such as scripts, applets, servlets and activeX controls.
-Dynamic HTML  (DHTML) allows Web developers to include more graphical interest and interactivity.
-Cascading style sheets (CSS) contain the formats for how a particular object should be displayed.
-Ruby on Rails (RoR) provides technologies for developing object-oriented, database-driven Web sites.
-Web 2.0 allows Web sites to provide a means for users to:

• Share personal information

• Allow users to modify Web site content

• Have application software built into the site

-Web page authoring software can create modern web pages that include images, video, audio, animation and other effects such as:

• Dreamweaver

• Expression web

• Flash

• Sharepoint designer

Program Development consists of a series of steps programmers use to build computer programs

Step 1-Analyze requirements:-
1) Reviews the requirements
2) identifies input, processing, and output A.K.A IPO chart.
Step 2-Design solution:-
1) Design a solution algorithm
2) Structured design where the programmer begins with the general design before moving towards detailed design.
3) Hierarchy chart shows program modules graphically.
4) Object oriented design is where programmer packages the data and program into a single object A.K.A encapsulation
5) Sequence control structure shows one or more actions following each other in order.
6) Selection control structure tells the program which action to take based on certain conditions.
7) Repetition control structure enables a program to perform one or more actions repeatedly as long as o certain condition is met.
8) A Flowchart graphically shows the logic in a solution algorithm. This software is easy to modify and update the flowcharts.
9) The pseudo code uses a condensed form of English to convey program logic.
10) Unified modeling language (UML) standard notation for object modeling and developmen.
Step 3-Validate Design:-
Check for logic error using test data.
steps:-
1) Development various sets of test data.
2) Determine the expected results.
3) Step through the algorithm.
4) Compare the results.
5) Repeat steps for each set of test data.
Step 4-Implement design:-
Using a program development tool that assists the programmer by:-
- Generating or providing some or all code.
-Writing the code that translates the design into a computer program.
- Creating the user interface.
Extreme programming a strategy where programmers immediately begin coding and testing as soon as requirements are defined.
Step 5-Test solution:-
The goal of program testing is to ensure the program runs correctly and is error free.
-Some errors are syntax errors and logic errors
-Debugging is the program involves removing the bugs.
-A beta is a program that has most or all of its features and functionality implemented.
Step 6-Document solution:-
In this step the programmer performs two activities which is :-
-Review the program code.
-Review all the documentation.

Chapter 12

Chapter 12

 Exploring Information System Development

System development is the development of an information system. System is a set of components that interact to achieve a common goal. System development should involve representatives from each department in which the proposed system will be used.

Information system is a collection of hardware, software, data, people and procedures that work together to produce quality information.

There are 5 phases in system development life cycle, below is the introduction of each phases:
1) Planning
- Review project requests.
- Allocate resources.
- Form project development team.
- Brainstorm idea and concept.
2) Analysis
- Analyse ideas and concepts from planning phase and determine the best.
- Study current system.
- Determine user requirement.
3) Design
- Acquire hardware and software.
- Create prototype.
- Develop details of system.
4) Implementation
- Install and test prototype.
- Train users.
- Improve prototype if needed.
5) Operation, Support and Security
- Perform maintenance activities.
- Monitor system performance.
- Maintain and update system security.

-General guidelines for system development are:-
Group activities or task into phases
Involve users
Define standards
-Project management is the process of planning, scheduling, and then controlling the activities during system development which mostly aim at Project scope, required activities, time estimates for each activity, cost estimates for each activity, order of activities, and activities that can take place at the same time.
1) Gantt chart is a popular tool used to plan and schedule the time relationships among project activities.
2) PERT (program evaluation review technique) chart is a project management tool used to schedule, organize and coordinate tasks within the project.
-Feasibility is a measure of how suitable the development of the system will be to the organization. In a term of:-
 Operational feasibility
Schedule feasibility
Technical feasibility
Economic feasibility
-Documentation is the collection and summarization of data and information.
Techniques used by the members of the project team to gather data and information during system development:-
1) Review documentation.
2) Observe.
3) Survey.
4) Interview.
5) JAD (joint application design) session.
6) Research.

-System development project is required when:-
1) A user may request a new or modified system.
2) Organisation wants to improve hardware, software or other technology.
3) Situations beyond an organization's control might require a change.
4) Management might mandate a change.
5) A user may request a new or modified information system using a request for system services or a project request.

Activities that involve during  the phases of system development life cycle: -
-Planning Phase is for a project begins when the steering committee receives a project request. Four major activities are performed is:-
1) Review and approve the project request.
2) Prioritize the project request.
3) Allocate resources.
4) From a project development team.

Analysis

 Two major activities that are performed:
1) Preliminary investigation- determines and defines the exact nature of the problem or improvement as well as interview the user who submitted the request.
2) Perform detailed analysis- study of current system, determine the users' wants, needs and requirements and recommend a solution.
Tools that are used during analysis phase:
1) Process modeling (analysis and design technique that describes the processes that transform inputs into outputs) is done during the analysis phase and it consists of:
i) Entity-relationship diagram (ERD)- a tool that graphically shows the connections among entities (objects in a system that have data) in a system.
ii) Data flow diagram (DFD)- a tool that graphically shows the flow of data in the system.
iii) Project dictionary- contains all documentations deliverables of a project. Style of writing is structured English.
2) Decision table and decision tree.
i) Decision table- a table that lists a variety of conditions and actions that correspond to each condition. In table format.
ii) Decision tree- shows the conditions and actions graphically.
3) Data dictionary- stores the data item's name, description and other details about each data item.
4) Object modeling- combines data with the processes that act on the data into a single unit called object.
5) UML (Unified Modeling Language)- standard notation for object modeling and development.
Examples of diagram included in UML:
1) Use case diagram- graphically shows how actors (users) interact with the information system.
2) Class diagram- graphically shows classes and subclasses in a system.
Steering committee will discuss the system proposal and decides which alternative (packaged software, custom software, outsourcing) to pursue.

 Design 

Activities that are performed:
1) Acquire hardware and software
Steps:
i) Identify technical specifications.
ii) Solicit vendor proposals.
iii) Test and evaluate vendor proposals.
iv) Make a decision.
2) Develop all of the details of the new or modified information system
Involve:
i) Database design.
ii) Input and output design.
iii) Program design.
After that, a prototype (working model of proposed system) will be created.
With the help of:
1) Computer-aided Software Engineering (CASE)- tools that are designed to support one or more activities of system development.
It contains:
i) Project repository.
ii) Graphics.
iii) Prototyping.
iv) Quality assurance.
v) Code generator.
vi) Housekeeping.

Implementation 

1) Develop programs
Steps:
i) Analyse the requirements
ii) Design the solution.
iii) Validate the design.
iv) Implement the design.
v) Test the solution.
vi) Document the solution.
2) Install and test the new system
Various test performed:
i) Unit test- verifies that each individual program or object works by itself.
ii) System test- verifies that all programs in an application work together properly.
iii) Integration test- verifies that an application works with other applications.
iv) Acceptance test- check the new system to ensure that it works with actual data.
3) Train users
It involves showing users how to use the new hardware and software in the system by:
i) One-on-one sessions.
ii) Classroom-style lectures.
iii) Web-based training.
4) Convert to new system
Types of conversion strategies:
i) Direct conversion- directly convert old system to new system.
ii) Parallel conversion- converting old system to new system while still using old system.
iii) Phased conversion- converting old system to new system in various phase. For example, 70% usage on old system and 30% usage on new system for first phase. And 30% usage on old system and 70% usage on new system for last phase.
iv) Pilot conversion- rolling out new system for small group of users for testing and evaluation.

 Operation, Support and Security
Activities that are performed:
1) Perform maintenance activities- to maintain the lifetime of the system.
2) Monitor system performance- to see if any improvement is needed.
3) Assess system security- manage the security and keep it updated.
Computer security plan should have:
1) Identify all information assets of an organisation.
2) Identify all security risks that may cause an information asset loss.
3) For each risk, identify the safeguards that exist to detect, prevent and recover from a loss.

Chapter 11

Chapter 11
Manage Computing Securely, Safely and Ethically


Computer security risk- any event or action that could cause a loss of or damage to computer hardware, software, data, information and processing capability.
Type of computer security risk:
Cybercrime- an online or internet-based illegal act.
For example:

1. Hackers- where a person's computer is broken into so that any personal or sensitive information could be obtained. But there are ethical hackers (provide benefit) and unethical hackers (steal information).
2. Crackers- where a computer program's license or password is bypassed.
3. Script kiddies- where a person uses existing scripts or code to hack into a computer.
4. Corporate spies- a covert gaining competitor's information.
5. Unethical employees- employee who obtain company's information and sell it.
6. Cyberextortionists- crime involving attack or threat of attack with purpose to get money out of it.
7. Cyberterrorists- act of internet terrorism in terrorists activities, including acts of deliberate, large scale disruption of computer networks by the means of tools such as computer viruses.

Internet and Network Attacks

Information transmitted over networks has a higher degree of security risk than information kept on an organization’s premises. An online security service is a Web site that evaluates your computer to check for Internet and e-mail vulnerabilities

Types of internet and network attacks:

1) Computer virus- affects a computer negatively by damaging computer system and hardware.

2) Worm- replicate itself and will take up hard disk space and internet bandwidth.

3) Trojan horse- hides itself and looks like a legitimate program that will steal information.

4) Rootkit- hides in a computer and allows someone from remote location to take full control.

-An infected computer has one or more of the following symptoms:

• Operating system runs much slower than usual.
• Available memory is less than expected.
• Files become corrupted.
• system properties change.
• Music or unusual sound plays randomly.
• Operating system shuts down unexpectedly.
• Programs or files do not work properly.
• Operating system does not start up.

-A botnet is a group of compromised computers connected to a network. A compromised computer is know as a zombie.
-A denial of service attacks (Dos attack) disrupts computer access to internet services.
-A back door is a program or set of instructions in a program that allow users to bypass security controls.
-Spoofing is a technique intruders use to make their network or internet transmission appear legitimate.
-A firewall is hardware and/or software that protects a network’s resources from intrusion

-Intrusion detect

ion software:-

• Analyzes all network traffic
• Assesses system vulnerabilities
• Identifies any unauthorized intrusions
• Notifies network administrators of suspicious behavior patterns or system breaches.

-Honeypot;-

Vulnerable computer that is set up to entice an intruder to break into it. 

Unauthorized Access and Use:-

-Unauthorized access is the use of a computer or network without permission
-Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities.
-Organizations take several measure to help prevent unauthorized access and use
Acceptable use policy
Disable file and printer sharing
Firewalls
Intrusion detection software
-Access controls define who can access a computer, when they can access it and what actions they can take

Two-phase processes called identification and authentication

• User name
• Password
• Passphrase
• CAPTCHA

-A bio-metric device authenticates a person’s identity by translating a personal characteristic into a digital code that is compared with a digital code in a computer

-Digital forensics is the discovery , collection, and analysis of evidence found on computer and network. many areas use digital forensics such as 

• Law enforcement
• Criminal prosecutors
• Military intelligence
• Insurance agencies
• Information security departments

Hardware Theft and Vandalism:

-Hardware theft is the act of stealing computer equipment

-Hardware vandalism is the act of defacing or destroying computer equipment.

To help reduce the of change of theft, companies and schools use a variety of security measures

• Physical access controls
• Alarm system
• Cables to lock equipment
• Real time location system
• Password, possessed objects, and bio-metrics

-Software theft occurs when someone; -

• Steals software media.
• Intentionally erases programs.
• illegally copies a program.
• illegally registers and/or activates a program.

Software Theft: -

-A single-user license agreement typically contains the following conditions 

permitted to

• install the software on one computer
• Make one copy of the software
• Remove the software from your computer before giving it away or selling it

Not permitted to

• install the software on a network
• Give copies to friends or colleagues while continuing to use the software 
• Export the software 
• Rent or lease the software

Copying, loaning, borrowing, renting, or distributing software can be a violation of copyright law where some software requires product activation to function fully.

-Information theft occurs when someone steals personal or confidential information .

-Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.

-A digital signature is an encrypted code that a person, website, or organization attaches to an electronic message to verify the identity of the sender.

popular security techniques include:-

• Digital certificates
• Transport layer security (TLS)
• Secure HTTP
• VPN

-A system failure is the prolonged malfunction of a computer. A variety of factors can lead to system failure including:-

• Aging hardware
• Natural disasters
• Electrical power problems such as noise, under-voltages and over-voltages
• Errors in computer programs.

Two ways to protect from system failures caused by electrical power variations include surge protectors and uninterruptable power supplies (UPS).

-A backup is a duplicate of a file, program, or disk that can be used if the original is lost, damaged. or destroyed. To back up a file means to make a copy of it. Offsite backups are stored in a location separate form the computer site such as cloud storage.

Ethics and Society:-

The bets way to prevent security risk is to have ethics and society.

-Computer ethics are the moral guidelines that govern the use of computer and information systems.

-Intellectual property rights are the rights to which creators are entitled for their work. A copyright protects any tangible form of expression.

-IT code of conduct is a written guideline that helps determine whether a specific computer action is ethical or unethical. The IT code of conduct:- 

1. Computers may not be used to harm other people.

1. Employees may not interfere with others computer work.

1. Employees may not meddle in others computer files.

1. Computers may not be used to steal.

1. Computers may not be used to bear false witness.

1. Employees may not copy or use software illegally.

1. Employees may not use others computer resource without authorization.

1. Employees may not use others intellectual property as their own.

1. Employees shall consider the social impact of programs and system they design.

1. Employees always should use computers in a way that demonstrates consideration and respect for fellow humans.

Green computing involve reducing the electricity and environmental waste while using a computer.
Green computing suggestions:
1) Use computers and devices that comply with the Energy Star program.
2) Turn off computers when not in use.
3) Use LCD monitor instead of CRT monitor.
4) Turn on power save mode.
5) Use paperless method to communicate.
6) Recycle paper.
7) Buy recycled paper.
8) Recycle toner cartridges.
9) Recycle old computers, printers and other devices.
10) Telecommute to save gas.
11) Use video conferencing and VoIP for meetings.

Information privacy- refers to the right of individuals and companies to deny or restrict the collection and use of information about them.
Examples on how to safeguard personal information:
1) Fill only necessary information on any form.
2) Avoid shopping club and buyer cards.
3) Ask before giving personal information to any merchants.
4) Install a cookie manager to filter cookies.
5) Turn off file and printer sharing on internet connection.
6) Install a personal firewall.
7) Inform merchant not to distribute your personal information.
8) Clear history file frequently on browser.
9) Do not reply to spam for any reason.
10) Surf the web anonymously.

Cookie- a small text file that a web server stores on your computer. It allows personalisation, store users' passwords, assist with online shopping, track how often users visit a site and target advertisement.

Spam is an unsolicited e-mail message or newsgroup posting.
E-mail filtering blocks e-mail messages from designated sources.
Anti-spam programs attempt to remove spam before it reaches your inbox.
Phishing is a scam where an official looking e-mail message that attempts to obtain your personal and financial information.
Pharming is a scam where spoofing is used as an attempt to obtain your personal and financial information.
Content filtering is the process of restricting access to certain material on the web.
Web filtering software restricts access to specified websites. 

Chapter 10

Chapter 10

Managing a database

Database is a collection of data organised in a manner that allows access, retrieval and use of that data. There a data (collection of unprocessed items such as text, image, numbers, audio and video). Information is where it processed data such as documents. images, video, and audio. 

there were database software, they called database management system (DBMS) that will help managing a database.

It allows users to:

1) Create a computerised database.

2) Add, modify and delete data.

3) Sort and retrieve data.

4) Create forms and reports from the data.

-Data integrity identifies the quality of the data

-Garbage in, garbage out (GIGO) points out the accuracy of a computer’s output depends on the accuracy of the input

Valuable information is what every users need and it is very important for a company in its daily operation and long term decision or strategies.

Characteristics of valuable information:

1) Accurate- valuable information needs to be accurate and free from error.

2) Timely- valuable information needs to be up to date.

3) Organised- valuable information needs to be organised for easier reading.

4) Accessible- valuable information needs to be accessible for any users at any time.

5) Useful- valuable information needs to be useful in terms of its content.

6) Cost effective- valuable information needs to be cost effective that is getting high quality information at low price.

The Hierarchy of Data

A character is one byte

-Numbers, letters, space, punctuation marks, or other symbols

A field is a combination of one or more related characters

-field name

-field size

-Data type

-File maintenance refers to the procedures that keep data current. an example of file maintenance is adding records, modifying records, and deleting records.

-Adding record = add new records to a file when they obtain new data.

-Modifying records = users modify a record to correct inaccurate data or update old data.

-Deleting records = when a record no longer is needed, a user deletes it from a file

Validation compares data with a set of rules or values to find out if the data is correct

i) Alphabetic/Numeric check (ii)Range check (iii)Consistency check (iv)Completeness check (v)Check digit (vi)Other checks

File Processing Versus Databases

Features in database management system:

1) Data dictionary- contains data about each file in the database and each field in those lines.

2) Query language- consist of simple, english-like statements that allow users to specify the data to display, print or store.

3) Query by example (QBE)- provide a graphical user interface to assist users with retrieving data.

4) Form- window on the screen that provide areas for entering or modifying data in a database.

5) Report generator- allows users to design a report on the screen, retrieve data into the report design and then display or print the report.

6) Security- only authorised users can access data at permitted times such as access privileges and principle of least privilege.

7) Backup and restore- to save the data in database in another storage medium and can be returned to its original form later.

8) Data model- consists of rules and standards that define how the database organises data.

For example:

• Relational database- stores data in tables that consist rows and columns. Relationship is the link within the data.
• Object oriented database (OODB)- stores data in objects. Examples of applications are multimedia database, groupware database, computer-aided design database and hypertext database.
• Object relational database- create relationship between object oriented data.
• Multidimensional database- can store data in more than two dimensions of data. A.k.a hypercube and it can consolidate data much faster than a relational database.

9) Data warehouse- huge database that stores and manages data required to analyse historical and current transactions.

Features of Web database: 

*Shop for products or services- Amazon, Ebay, Alibaba

*Buy or sell stocks- NASDAQ, Suretrader.com.

*Search for a job- Jobstreet, Moster.com

*Make airline reservations- Air Asia, Malaysia Airline, Royal Brunei Airline.

*Register for college classes- UCSI Information Integrated System (IIS).

*Check semester grades- UCSI IIS, LMS.

Database Administration:-

1. The database design guidelines
2. Determine the purpose of the database.
3. Design the table or files.
4. Design the record and fields for each table or files.
5. Determine the relationships among the table and files.

Database analysts and administrators are responsible for managing and coordinating all the database activities =

• Database analyst (DA)- decides on proper field placement, defines data relationships, and identifies users access privileges.
• Database Administrator (DBA)- Creates and maintains the data dictionary, manages security, monitors performance, and checks backup and recovery procedures.

Chapter 8

Chapter 8

Types of Storage

Storage~~

Storage holds data, instructions and information for future use. A storage medium is the physical material on which a computer keeps data, instructions and information.Every computer user must use a storage as it is used to store various information and data. Storage in pc also have limited space and its call capacity. Capacity is the number of bytes a storage medium can hold

A storage device is the computer hardware that records and/or retrieves items to and from storage media.

-Reading is the process of transferring items from a storage medium into memory.

-Writing is the process of transferring items from memory to a storage medium.    

Access time measures:

The amount of time it takes a storage device to locate an item on a storage medium

The time required to deliver an item from memory to the processor

Types of storage devices

A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information. Hard disks can store data using longitudinal recording or perpendicular recording. Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk. Always keep a backup of your hard disk

How disk cache work:

1) A special purpose chip on the hard disk called controller receive request for data from processor.

2) It will checks disk cache for requested item.

3) If the item is not found in disk cache, it will locate the requested item on platters.

4) Lastly, it will transfer the item to processor.

-RAID (redundant array of independent disks) is a group of two or more integrated hard disks

-An external hard disk is a separate free-standing hard disk that connects to your computer with cable or wirelessly.

-A removable hard disk is a hard disk that you insert and remove from a drive.

-A network attached storage (NAS) device is a server connected to a network with the sole purpose of providing storage.

Flash memory storage- a type of solid state media and contain no moving parts.

Solid state drive (SSD) have several advantages over magnetic hard disk such as faster access time, faster transfer rates, generate less heat and consume less power and last longer.

Most of the gaming laptop got SSD

-A memory card is a removable flash memory device that you insert and remove from aa slot in a computer.

-USB flash drives plug into a USB port on a computer or mobile device.

-Cloud storage is an internet service that provides storage to computer users.

-An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser.

-Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information where it read and writes data and information on a tape.

-A magnetic stripe card contains a magnetic stripe that stores information.

-A smart card stores data on a thin microprocessor embedded in the card.

Chapter 7

Chapter 7
Understanding Output

Output is data that has been processed into a useful form.

Types of outputs:

1. Display devices : visually conveys text, graphics, and video information

• A monitor is packaged as a separate peripheral

        -LCD monitor

        -Widescreen

• Liquid crystal display (LCD) uses a liquid compound to present information on a display device
• Resolution is the number of horizontal and vertical pixels in a display device

         -A higher resolution uses a greater number of pixel and that why we hav 2k and 4k resolution

• Graphic processing unit (GPU) controls the manipulation and display of graphics on a display device.
• Plasma monitor- display devices that use gas plasma technology.
• Television- such as digital television (DTV) and HDTV.
• CRT monitor- uses cathode-ray tube to display.

      2. Printer- device that accept text and graphics output from a computer and transfers the information to paper.

• Types of printer:
• 1) Non-impact printer- forms characters and graphics on a piece of paper without striking and leaving mark on paper.
• For example:
• i) Ink-jet printer- forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper.
• ii) Photo printer- produces colour photo-lab-quality pictures.
• iii) Laser printer- high speed printer that uses laser technology. A rotating mirror will deflect a laser beam across surface of a drum that creates charges which will attract toner to stick to the drum. The toner will transfer to the paper when drum rotate and press against paper. And a set of roller uses heat and pressure to fuse the toner permanently to the paper.
• iv) Multifunctional peripheral- a single device that scan, print, copies and fax.
• v) Thermal printer- generate images by pushing electrically heated pins against the heat sensitive paper. For example, thermal wax-transfer printer and dye-sublimation printer.
• vi) Mobile printer- small, lightweight and battery-powered printer for portability.
• vii) Label printer- small printer that prints on adhesive-type material.
• viii) Plotter- used to produce high quality drawings.
• ix) Large-format printer- create photo-realistic quality colour prints on a larger scale.
• 
  
• 2) Impact printer- form characters and graphics on a piece of paper by striking and leaving mark on paper.
• For example:
• i) Dot-matrix printer- produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon.
• ii) Line printer- prints an entire line at a time.
• 
  

       3. Speakers, Headphones and Earbuds- an audio output device that produces sound.

• For example:
• 1) Speaker- convert analog audio signals into equivalent air vibration in order to make audible sound.
• 2) Headphones- speaker that cover the ear.
• 3) Earbuds- rest inside ear canal.
• 
  

        4.  Data projector- is a device that takes text and images displaying on computer screen and projects them on a larger screen.

• For example:
• 1) LCD projector.
• 2) Digital light processing (DLP) projector.
• 
  

         5. Interactive white board- a touch sensitive device, resembling a dry-erase board that displays the image on a connected computer screen.