Chapter ?

Chapter ? :- My opinion and conclusion

This subject was amazing and i have to thank our lecture ( Miss Wan Irma) for teaching us this subject, we were gland that she will teach as anther subject next semester or teach us until we graduated, ones more i will like to thank our lecture.

My opinion about this subject, this subject teaches me a lot about computer and its programs in it.
The first two week i was absent due to my passport issues, i miss a lot of class and i have to catch the lessons. I manage to catch up the lessons and i did good in my midterm. This subject explained a lot about the function of computer, Nowadays people use computer but they don't know how the computer actually work and the way to take care of the computer.

After i finished this Blog i felt FREEDOM finally

                                     

Now i can focus on studying for the final exam which coming next week. I pray to god ( ALLAH) that i get good marks and success in my life not give your parent a burden.

Don't put burden on your parents because they want you to become a successful man.

Miss and to my friend if i did something wrong and behave in a unmature way i am very very sorry 

  Since our computer application class is over, i would take this chance to thanks to Miss Wan Irma for teaching us. Maybe i disappointed my lecture by not paying attention in class. I had a wonderful experience in this subject and had a lot of ideas and information that i don't know myself.

and this is my last blog. i am tried of doing this blog but i had a wonderful time doing this blog.

Chapter 14

Chapter 14:- Enterprise Computing

Enterprise computing is a buzzword that refers to business-oriented information technology that is critical to a company's operations. It involves the use of computers in networks such as LANs and WANs (Wide Area Network), or a series of interconnected networks that encompasses a variety od 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. For example,  Business intelligence, Business process management, and Business process automation. Resources will be managed by managers by Planning, Organising, Leading, and Controlling.
-The information system is a set of hardware, software, data, people and procedures that work together to produce information.
Functional units within an enterprise:-

• 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

1)-Marketing information system serves as a central repository for the tasks of a marketing                     department.

• Sales

1)-Sales force automation (SFA) software equips traveling salespeople with the electronic tools they need to be more productive.

• Distribution

1)-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

1)-Customer interaction management (CIM) software manages the day-to-day interactions with customers.

• Information Technology

1)-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.

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

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

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

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

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

7)-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.

8)-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.

Enterprise-wide Technologies and Methodologies:-

-Portal is a collection of links, content, and services presented on a web page that is interesting for  a  particular job function.

-Data warehouse is a huge database that stores and manages the data required to analyze  historical and current transactions.

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

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

-Web Services allows business to create products and B2B interactions over the internet.

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

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

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

-Virtualization is the practice of sharing or pooling computing resources.

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

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

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

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

Types of E-commerce:

1) E-retail- occurs when retailers use the Web to sell their products or services.

2) Finance- financial tools such as online banking and online trading services are provided.

3) Travel- travel related services like airline reservations, destinations are provided.

4) Entertainment and Media- entertainment and media such as video, audio or games are provided.

5) Health- health related services or information are provided.

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

• Heavy use
• Maximum availability
• 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.

-Storage area network (SAN) is a high-speed network  that provides storage to other servers to  which it is attached.

-Enterprise storage system is a strategy that focuses on the availability, protection, organization, and  backup of storage in a company.

-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.

-Thin client is a small terminal like computer that mostly relies on a server for data storage and  processing is usually done on a server.

-High-availability system continues running and performing tasks for at least 99 percent of the time

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

-Interoperability is the ability of an information system to share information with other information systems within an enterprise.

-Disaster recovery plan is a written plan describing the steps a company would take to restore computer operations in the event of a disaster. contains four major components:-

• Emergency plan
• Backup plan
• Recovery plan
• Test plan

Chapter 13

Chapter 13:- Computer programs and programming languages

Nowadays everyone knows how to use the computer even kids and adult people but they don't know how a computer works and how it be programmed. Basically, the computer had been a program by the programmer using a programming language.


Low-level Language:-
-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 (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. 

Other Programming language and development tools:-

-Fourth generation language is a nonprocedural language that enables users and programmers to access data in a database the popular one is 4GL is SQL.

-Classic programming language include:-

• Ada
• ALGOL
• APL
• BASIC
• Forth
• FORTRAN
• Hyper Talk
• LISP
• Logo
• Modula-2
• Pascal
• PILOT
• PL/1
• Prolog
• RPG
• Smalltalk

-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

-Multimedia authoring software allows programmers to combine text, graphics, animation, audio, and video in an interactive presentation.

For example;-

-Tool book

-Director

 

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

where it is same as the system development life cycle which contains five steps and also programs development life cycle:-

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 a set of activities used to build an information system. A system is a component that interact to achieve a common goal. Information system (IS) is a collection of hardware, software, data, people, and procedures that work together to produce quality information. system development activities are grouped into phases, collectively called the system development life cycle (SDLC) 

System Development:-

They are five processes in system development which are Planning, Analysis, Design, implementation, operation support, and security.

1) Planning

• Review project request
• Allocate resources
• From project development team
• Select a correct team

2) Analysis

• Analyse idea and concepts from planning phase and determine the best.
• study current system of the idea
• Determine user requirement

3) Design

• Acquire hardware and software
• Develop details of system
• Create prototype

4) Implementation

• Install/ build the system
• Train users
• Improve prototype if needed

5) Operation, support, and security

• Perform maintenance activities based on schedule
• Monitor system performance
• Maintain and update system security every week if needed.

-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 phase consists of two major activities that are performed:-

1) preliminary investigation is to determine and defines the exact nature of the problem or improvement as well as interview the user who submitted the request.

2) perform the detailed analysis is to study of current system works where it determines the user's wants, needs, and requirements and recommend a solution.

Tools that used for Analysis phase are:-

• Process modeling - is an analysis and design technique that describes processes that transform inputs into an output. under process modeling we get three processes which are:-

         i) Entity relationship diagrams (ERD) is a tool that graphically shows the connections among                  entities (objects in a system that have data) in a system.

        ii) Data flow diagram (DFD) is a tool that graphically shows the flow of data in the system.

       iii) Project dictionary contains all the documentation and deliverables of a project. Style of                        writing is structured English.

• The decision table is a table that lists a variety of conditions and the actions that correspond to each condition. Decision tree also shows conditions and actions, but it shows them graphically.
• The data dictionary stores the data item's name, description, and other details about each data item.
• Object modeling combines the data with the processes that act on the data into a single unit, called an object.
• UML (unified modeling language) has been adopted as a standard notation for object modeling and development where two diagrams include which is use case diagram and class diagram.

         - Use case diagram is a graphically shows how actors interact with the information system. The            diagram is considered easy to understand.

         - The class diagram is a graphically shows classes and subclasses in a system. In the class

          diagram. we have the inheritance to inherit methods and attributes of higher levels. The                       steering committee will discuss the system proposal and decides which alternative (Packaged               software, Custom software and outsourcing) to pursue.

 

-Design Phase consists of two major activities which are acquired hardware and software and develop all of the details of the new or modified information system. The step is :-

• Identify technical specifications
• Solicit vendor proposals
• Test and evaluate vendor proposals
• Make a decision 

The next step is to develop detailed design specification where sometimes called a physical design:-

• Database design
• Input and output design
• Program design

After that, a prototype will be created with the help of :

1) Computer aided software Engineering (CASE) tools are designed to support one or more activities of system development which contain: -

• Project repository
• Graphics
• Prototyping 
• Quality assurance
• Code generator
• Housekeeping

-Implementation Phase is to construct the new or modified system and then deliver it. The implementation involves :-

• Develop Programs
• Install and test the new system
• Train users
• Convert to the new system

The program development life cycle follows these steps:

1. Analyze the requirements
2. Design the solution
3. validate the design
4. Implement the design
5. Test the solution

Various test performed:-

1. The unit test verifies that each individual program or object works by itself.
2. System test verifies that all programs in an application work together properly.
3. Integration test verifies that an application works with other applications.
4. Acceptance test checks the new system to ensure that it works with actual data.

-Training involves showing users exactly how they will use the new hardware and software in the system, were it have three training which is:-

- One-on-one sessions

- Classroom-style lectures

- Web-based training

Operating, support and security phase is to provide ongoing assistance for an information system and its users after the is implemented.

There are three processes in this system:-

1) Perform maintenance activities - to maintain the lifetime of the system.

2) Monitor system performance - to see id 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 organization.

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

-A computer security risk is any event or action that could cause a loss or damage to computer hardware, software, data, or even important information.
-A cyber crime is an online or internet-based illegal act such as Hackers, crackers, script kiddies, corporate spies and more.
Explanation  for the cyber crime :-

-Hackers are person who uses computer to gain unauthorized access to data and personal information.

-Crackers also known as a black hat hacker is an individual with extensive computer knowledge whose purpose is to breach or bypass internet security or gain access to software without paying royalties. The general view is that, while hackers build things, crackers break things.

-Script Kiddies are person who uses existing computer scripts or codes to hack into computers, lacking the expertise to write their own.

-An online security service is a web site that evaluates your computer to check for internet and e-mail vulnerabilities.

Type of internet and network attacks:-

• Computer virus- Affects a computer negatively by altering the way the computer works.
• Worm- Copies itself repeatedly using up resource and completely shut down the computer and network.
• Trojan Horse- A malicious program that hides within or looks like a legitimate program.
• Rootkit- A set of software tools that enable an unauthorized user to gain control of a computer system without being detected.

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

1. Operating system runs much slower than usual.
2. Available memory is less than expected.
3. Files become corrupted.
4. system properties change.
5. Music or unusual sound plays randomly.
6. Operating system shuts down unexpectedly.
7. Programs or files do not work properly.
8. 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.
2. Employees may not interfere with others computer work.
3. Employees may not meddle in others computer files.
4. Computers may not be used to steal.
5. Computers may not be used to bear false witness.
6. Employees may not copy or use software illegally.
7. Employees may not use others computer resource without authorization.
8. Employees may not use others intellectual property as their own.
9. Employees shall consider the social impact of programs and system they design.
10. Employees always should use computers in a way that demonstrates consideration and respect for fellow humans.

Green computing - involves reducing the electricity and environmental waste while using a computer.

-Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them where huge database store data online and it is important to safeguard your information.

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.

-A cookie is a small text file that a web server stores on your computer such as:-

• Allow for personalization
• Store users password
• Assist with online shopping
• Track how often users visit a site
• Target advertisements

-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 to your inbox.

-Phishing is a scam in which a perpetrator sends an official looking e-mail message that attempts to obtain your personal and financial information.

-Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing.

-Content filtering is the process of restricting access to certain material on the web.

-Web filtering software restricts access to specified websites.

-Social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of trust and naivety.

-Employee monitoring involves the use of computers to observe, record and review an employee's use of a computer.

Chapter 10

we skip chapter 9 which is about Network and communications where it is similar to chapter 2. we jump into chapter 10 which is about Managing a database.

Chapter 10:- Managing a database

-The database is a collection of data organized in a manner that allows accessing retrieval and use of that data.
-Data  is a collection of unprocessed items such as text, number, images, video, and audio.
-Information is where it processed data such as documents. images, video, and audio.
-Database software,often called a database management system (DBMS), allows users to create a computerized database, create forms and reports from the data, sort and retrieve data and modify and delete 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 should have the following characteristics:-

• Accurate- very valuable information need to be accurate and out of error
• Verifiable- 
• Timely- information need to be on time
• Organized-
• Accessible
• Useful
• Cost-effective

The Hierarchy Of Data: -

• Character
• Field
• Records
• Files

-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 is add new records to a file when they obtain new data.

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

-Deleting records is where the users delete the old record when no longer needed.

Validation: -

Validation compares data with a set of rules or values to find out if the data is correct. Database validation is required when database get corrupted to check for corruption.

Type of validity checks: -

• Alphabetic/Numeric check
• Range check
• Consistency check
• Completeness check
• Check digit

File processing versus Database approach:- 

File processing system:

• Each department has its own set of files.
•  Have data redundancy.
•  Isolate data.

Database approach:

•  Programs and users share data.
•  Reduce data redundancy.
•  Improve data integrity.
•  Share data.
•  Allow easier access.
•  Reduce development time.
•  More vulnerable.

Database Management Systems: -

•  Data dictionary- contains data about each file in the database and each field in those lines.
•  Query language- consist of simple, English-like statements that allow users to specify the data to display, print or store.
•  Query by example (QBE)- provide a graphical user interface to assist users with retrieving data.
•  Form- window on the screen that provides areas for entering or modifying data in a database.
•  Report generator- allows users to design a report on the screen, retrieve data into the report design and then display or print the report.
•  Security- only authorized users can access data at permitted times such as access privileges and the principle of least privilege.
•  Backup and restore- to save the data in the database in another storage medium and can be returned to its original form later.
•  Data model- consists of rules and standards that define how the database organizes data.

         For example:

- Relational database- stores data in tables that consist rows and columns. The relationship is the link within the data.

- Object-oriented database (OODB)- stores data in objects. Examples of applications are a 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.

•  Data warehouse- a huge database that stores and manages data required to analyze 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:-

The database design guidelines

• Determine the purpose of the database.
• Design the table or files.
• Design the record and fields for each table or files.
• 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 holds data, instructions, and information for future use. A storage medium is the physical material on which a computer keeps data, instructions, and information.

-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.

Storage capacity:- 

-Access time is amount of time it takes a storage device to locate an item on a storage medium and time required to deliver an item from memory to the processor.

-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.

-The characteristics of a hard disk include: -

  -Capacity

  -Platters

  -Cylinders

  -Access Time

  -Sectors and Tracks

  -Read/write Heads

  -Transfer rate

  -Revolutions per minute

-How a hard disk work: -

the hard disk arms move the read/write head,which reads items and writes item in the drive but location often is referred to by its cylinder. A head crash occcurs when a read/write head touches the surface of a platter and always keep a backup of you hard disk.

-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.

-How disk cache works: -

-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: -

-Flash memory chips are a type of solid-state media and contain no moving parts

-Solid state drives (SSDs) have several advantages over magnetic hard disks

  -Faster access time

  -Faster transfer rates

  -Last longer

  -Generate less heat and consume less power

-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.