Information Technology

General description of MySQL MySQL was a free-software database engine originally developed and first released in 1995. MySQL is named after My, the daughter Michael Widenius, of one of the product’s originators. It was originally produced under the GNU General Public License, in which source code is made freely available. MySQL was originally owned by Sun Microsystems; when the company was purchased by Oracle Corp. in 2010, MySQL was part of the package. Although MySQL is technically considered a competitor of Oracle DB, Oracle DB is mainly used by large enterprises, while MySQL is used by smaller, more Web-oriented databases. In addition, MySQL differs from Oracle's product because it's in the public domain. MySQL can be used for a variety of applications, but is most commonly found on Web servers. A website that uses MySQL may include Web pages that access information from a database. These pages are often referred to as "dynamic," meaning the content of ea

Aggregate Functions These functions perform an operation on a set of fields and return a single value. Their use is relatively limited. They can be used in the following situations: The selection list of the SELECT statement A HAVING clause A COMPUTE clause Function                                                                                     Description AVG ([ALL| DISTINCT] expression) Returns the average value in the group. COUNT( [ALL|DISTINCT] expression) Counts the number of items in the group. COUNT_BIG( [ ALL|DISTINCT] expression) Counts the number of items in the group. the result is returned in the form of bigint number. GROUPING(Column_Name) Creates an additional column with a value of 1 operator or 0 if it is not the result of a CUBE or ROLLUP operator. MAX( expression) Returns the maximum value in the expression. MIN( expression) Returns the minimum value in the expression. SUM ( expression) returns the sum of the expression's value. STDE

Object oriented system development consists of Object Oriented Analysis Object Oriented Information Modeling Object Oriented Design Prototyping and Implementation Testing, Iteration and Documentation  Five major elements of Object Model: Abstraction Encapsulation Modularity Hierarchy Inheritance Image Courtesy Codeproject Abstraction Abstraction is one of the fundamental elements of object model. Three types of abstraction are- Entity Abstraction, Virtual machine abstraction, Coincidental abstraction. Encapsulation Encapsulation is the process of compartmentalization the elements of an abstraction that constitutes its structure and behavior and serves to separate the contractual interface of abstraction and its implementation. Modularity Modularization consists of dividing a program into modules which can be compiled separately , but which have connection with other modules. The connections between modules are the assumption which the modu

Among the most important information contained in a feasibility study is cost-benefit analysis- an assessment of economic justification for a computer based system project. Introduction Statement of the Problem Implementation Environment Constraints Management Summary and Recommendations  Important Findings Comments Recommendations Impact Alternatives Alternative System Configurations Criteria used in selecting the final approach System Description Abbreviated statement of scope Feasibility of allocated elements Cost Benefit Analysis Evaluation of Technical Risk Legal Ramification Other Project Specific Topics

Procurement Costs Consulting costs Actual equipment purchase or lease costs Equipment installation costs Costs for modifying the equipment site ( air conditioning , security etc) Cost of Capital Cost of Management  and staff dealing with procurement Start up Costs Cost of operating system software Cost of communication equipment installation ( telephone lines, data lines etc) Cost of start up personnel Cost of personnel searches and hiring activities Cost of disruption to the rest of organization Cost of management required to direct start up activity  Project Related Costs Cost of application software purchased Cost of software modifications to fit local systems Cost of personnel, overhead etc from in house application development Cost for training user personnel in application use Cost of data collection and installation data collection procedures Cost of preparing documentation Cost of development management On going Costs System maintenance

Types of Security Threats In general, network security threats can be classified into one of two categories: disruption,destruction and disaster and unauthorized access. disruptions are usually minor and temporary. Some disruptions may also be caused by or result in the destruction of data. Natural or man made disasters may occur that destroy host computers or large sections of the network. Unauthorized access refers to intruders (external hackers or organizational employees) gaining unauthorized access to files. The intruder may gain knowledge, change files to commit fraud or theft or destroy information to injure the organization.  Risk Assessment Developing a secure network means developing controls that reduce or eliminate threats to the network. Controls prevent, detect  and correct whatever might happen to the organization when its computer based systems are threatened. The first step in developing a secure network is to conduct a risk assessment. This is done by com

Using  regular expressions  is probably the best way. Here's an example ( live demo ): function validateEmail ( email ) { var re = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/ i ; return re . test ( email ); } But keep in mind that one should not rely only upon JavaScript validation. JavaScript can easily be disabled. This should be validated on the server side as well.

End user computing is the direct,hands on use of computers by end users to perform the information processing needed to accomplish their work activities. End user computing has grown dramatically because information services departments have not been able to keep up with the information processing requests of end users. Also dramatic improvements in micro computer  hardware and software capabilities have made personal computing attractive , affordable and effective for end users in many organizations. End user computing application areas include Office Automation,Information Management and retrieval, decision support and application development. An end user computing system consists of hardware ,software, people and data resources. Hard ware resources include: microcomputer workstations,  local area network servers,  departmental minicomputers   corporate mainframes.  Software resources consist of  application packages,  fourth generation languages  application d

Brief Background UML is a language for specifying,visualizing ,documenting and constructing the artifacts of software systems,as well as for business modeling and other non-software systems. UML has been developed by Grady  Booch, James Rumbaugh and Ivar Jacobson. Goals of UML are : To model systems using Object oriented concepts. To establish an explicit coupling to conceptual as well as executable artifacts To address the issues of scale inherent in complex , mission critical systems. To create a modeling language that can be used by humans as well as machines.  Understanding the thirteen diagrams of UML 2.x is an important part of understanding OO development. Although there is  far more to modeling than just the UML  the reality is the UML defines the standard modeling artifacts when it comes to object technology. There are three classifications of UML diagrams: Behavior diagrams . A type of diagram that depicts behavioral features of a system or business

Why use a LAN? The two basic reasons for developing a LAN are information sharing and resource sharing. Information sharing refers to business needs that require users to access the same data files ,exchange emails or search the internet for information. Resource sharing refers to one computer sharing a hardware device (for e.g a printer) or software package with other computers on the network. The main benefit of resource sharing is cost savings, while the main benefit  of information sharing is improved decision making. image courtesy Cray Networks Dedicated Server versus Peer-to-Peer Networks A dedicated server LAN has one computer that acts as the network server. It can connect with almost any other network,handle very large databases and use sophisticated LAN software. Moreover,high -end dedicated server LANs can be interconnected easily to form enterprise wide networks or in some cases replace the host mainframe central computer. Four common types of dedicated ser

The issues that confront us in relation to securing electronic transactions are : Confidentiality Integrity Availability Authenticity Non-repudiability Auditability Confidentaility Information should be protected from being read by external hackers or unauthorized internal users. It should be also safe while being transmitted on the network and make data unintelligible even if someone gets access to it. The content should be sent deciphered so that none other than the person who has the transformation algorithm can read it. Integrity Sometimes the message might be read and modified on its path. It should be possible to generate an alert on any modification -addition or deletion of the original content. Proper mechanisms are necessary to ensure end-to-end message content and copy authentication. Availability The information that is being stored or transmitted across communication networks should be available whenever required and to whatever extent as desired wi

Electronic Commerce increases Profits : Electronic commerce increases sales and decrease costs. Advertising on the web reaches all the users of that website. A firm can use the web to reach communities which are scattered geographically. The web's natural advantage is that it is low cost medium for disseminating information and processing transaction. for e.g the cost of advertising on the web is much less as compared to advertising in a newspaper. Another benefit of web based commerce is that information based industries excel here. A virtual organisation increases efficiency through the automation of processes. The cost of handling sales inquiries and determining product availability can be reduced with the help of e-commerce in the marketing process of the business. E-commerce increases the speed and accuracy with which businesses can exchange information which reduces costs on both sides of transactions. Another Advantage of e-commerce is

For creating a web site that is effective,the following objectives should be considered: To attract visitors to the Web site. To make the site interesting so that the visitor stay and explore. To persuade the visitors to follow the site's links to obtain information. To create the desired image of the organisation in the visitors mind. To reinforce positive images that the visitor may already have about the organisation. Why do Visitors arrive at a  Web site: To obtain general information about the company or organisation. Learning about the company's products or services. Buying the products and services offered by the company. Finding  out the services conditions and warranties applicable for the products they have purchased. Obtaining financial information helpful in making investment or credit granting decision. Identifying the people who manage the company or organisation.   Business should try to meet the following goals while constructing their

 HTML HTML is one of the fundamental technologies that the Web is built upon. HTML elements form the building blocks of all websites. HTML allows images and objects to be embedded and can be used to create interactive forms. It provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes and other items. It can embed scripts written in languages such as JavaScript which affect the behavior of HTML web pages. These features will help developers and businesses better engage with their customers.  JavaScript JavaScript is a part of the fabric of the Web. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles. Its an interpreted computer programming language and allows client-side scripts to interact with the user, control the browser, communicate asynchronously, and alter the document content that is displayed. It has also become common in ser

HyperText Markup Language HTML can be used to display any type of document that is available on the web. The computer that maintains the document (host computer) and the computer that displays the document may be at different geographical locations.HTML is a versatile language and can be used on any platform or desktop. Being platform independent documents written in HTML can be viewed on any platform. HTML elements are used to markup the document and inform the browser like Microsoft  Internet Explorer , about the action to be taken when a certain element is specified. Features of HTML HTML allows us to: Provide tags to make the document look attractive. Tags are used to represent the various elements of a Web page, like titles and images. Use graphics and display text in different fonts, sizes and color. You can enhance the presentation of the document using these elements. Create Hyper text links, also known as hyperlinks, to other documents or other portions of the sam

A Layered Technology Software Engineering is the establishment and use of sound engineering principles in order to obtain economically software that is reliable and works efficiently on real machines. The various layers are tools methods process a quality focus Software Engineering asks the following questions What is the problem to be solved? what are the characteristics of the entity that is used to solve the problem? How will the entity and the solution will be realized? How will the entity be constructed? What approach will be used to uncover the errors that were made in the design and construction of the entity? How will the entity be supported over the long term, when corrections,adaptations and enhancements are requested by users of the entity? The Software Process Software Engineering Institute has developed a comprehensive model that is predicated on a set of software engineering capabilities that should be present as an organization reaches dif

Project Management Concepts Software Project Management Activities Software Project Management Activities span the entire life of the software product, and hence is the primary concern of software engineering. It begins with the initial problem identification and finally ends when the software is retired. Steps involved in Project Management the objective and scope of work to be done the risks to be involved the resources to be required the effort or cost to be expended and  the schedule to be followed  The objectives identify the overall goals of the project, and the scope identifies the primary functions that the software is to accomplish and attempts to specify the bounds to each of the software functions. Risks Risk analysis is critical to Software Project Management. Risk analysis is actually a series of risk management steps that enable us to tackle risk: Risk identification Risk Assessment Risk Prioritization Risk Management strategies Risk Resolut

Definition of Client/ Server Computing Client /Server computing is the process and architecture allowing applications to be developed as efficiently as possible,exploiting the capabilities of personal workstation clients and intelligent server computers. A client typically uses a multiprocessing operating system with a graphical user interface called the frontend. The server is dedicated to one or more backend functions particularly the creation,management and manipulation of databases. What is Client/ Server? Client and Servers are seperate logical entities that work together over a network to accomplish a task. All client/server systems have the following distinguishing chatacteristics: Service Shared Resources Asymmetrical Protocols Transperancy of Location Mix and Match Message based exchanges Encapsulation of Services Scalability Integrity Thus client/ server characteristics allow intelligence to be distributes over a network. Different types of Servers  Fi

HTML5 You may well ask: “How can I start using  HTML5  if older browsers don’t support it?  HTML5  is not one big thing; it is a collection of individual features.  You may think of  HTML  as tags and angle brackets. That’s an important part of it, but it’s not the whole story. The  HTML5  specification also defines how those angle brackets interact with JavaScript, through the Document Object Model ( DOM ). HTML5  builds on that success of HTML4. HTML5  supports all the form controls from  HTML  4, but it also includes new input controls.  The doctype should already be on the first line of every  HTML  page. Previous versions of  HTML  defined a lot of doctypes, and choosing the right one could be tricky. In  HTML5 , there is only one doctype: <!DOCTYPE html>   HTML5  is here to stay Every element, every attribute, every feature of  HTML  that you’ve ever used — someone created them, decided how they should work, and wrote it all down. CSS3 Cascading