The computer industry suppliers can be classified into three groups , namely Hardware Suppliers, Software Suppliers and Service Suppliers. Suppliers of hardware include Mainframe manufacturers , peripheral vendors, computer leasing firms and used –system dealers. IBM is one of the major suppliers of mainframe computers. Peripheral vendors supply tape drivers, disk and diskette drives, printers [...]
Continue reading → There are three things one can do to prevent virus infection in a computer system. These are: 1. Limit sharing 2. Limit transitivity 3. Limit functionality Limit sharing One can limit sharing by limiting information flow so as to form a post office kind of communicating information domains in a network system. In such a [...]
Continue reading → An audit trail is designed to permit tracing of operation, whether it is related to insertion, deletion or updation of records or processing performed on the computer system. In audit trail, all the operations that a user performs during a log-in session are noted. When a user logs in, the system records the user’s account [...]
Continue reading → A benchmark is a sample program used for evaluating the performance of computer-based systems. It helps in the following manner: 1. Determination of the minimum hardware configuration needed t operate the system. 2. Testing the system in an ideal environment to determine comparative timings and then testing the system in a normal environment. 3. Determination [...]
Continue reading → The pictorial representation of information and instructions using GUI’s are more user-friendly and easy-to-understand than textual commands and lifeless screens. Nowadays, GUI (Graphical user Interface) is incorporated within most of the computer operating systems, pioneer among them being the Microsoft’s Windows 9X,2000 and XP. Note : GUI is a software design that allows you to [...]
Continue reading → There are two types of interviews. These are: 1. Unstructured 2. Structured Unstructured Interview Unstructured interview is an approach in which the questions and the corresponding responses are open-ended. The interviewer can ask questions which may not be directly related to the system under consideration. Unstructured interviews are conducted with only a general goal or [...]
Continue reading → In the system design process, the primary objective is to identify user requirements and to build a system that satisfies these requirements. Design of system is largely the logical design. The logical design can be sketched on a paper or on a computer terminal. The design, also including the physical design elements, describes the data [...]
Continue reading → Systems are designed to perform certain required functions – there could be new functions, or modifications of older functions. A system which is being designed will often require changes and re-orientation in the way an organization works. There could be changes in format of input, or reports, additional information to be gathered, new procedures to [...]
Continue reading → Equijoins are also commonly known as simple joins, or inner joins. Given two or more tables, an equijoin will return the results of these tables where a common column between any given pair of tables has the same value (an equal value). Equijoins are typically joins between foreign keys in one table to a primary [...]
Continue reading → So far, we have been dealing with only one table at a time in our SQL query examples. But typically the information needed to satisfy a user query requires more than one table. In new SQL 1999, you can not only join two or more tables in a number of different ways, but can also [...]
Continue reading → Of late, it has been observed that Automobiles running on the roads in Metro Cities sometimes catch fire. Many times the occupants escape unhurt but many times there are no so lucky. Daily one or the other car of different make catch fire in the city. By the time the fire brigade arrives on the [...]
Continue reading → The three are abbreviations of three small Automatic Telephone Exchanges which have been in use in the corporate sectors and small offices. PBX – stands for “Private Branch Exchange “ PABX – stands for “Private Automatic Branch Exchange “ EPBAX –stands for “Electronic Private Automatic Branch Exchange “ All are small automatic telephone exchanges having [...]
Continue reading → System Analyst has the following duties to perform : Estimate personnel requirements, cost and time for system’s implementation. Review and approve proposed system’s solutions Perform resource planning and scheduling for system’s personnel. Develop, implement and enforce procedural standards for performing tasks of system analysis and design. Evaluate performance of system’s personnel and report on personnel [...]
Continue reading → Automatic Telephone Exchange Strouger System During the decades 1950’s 1960’s & 1970’s all the Telephone Exchange in Delhi were automatic and were using Strouger System which was imported from Belgium. This system was of minimum Ten Thousand lines which means Ten Thousand people could talk to each other at a time. There were nine such [...]
Continue reading → A Linux shell is the program which interprets what you type on the command line and decides what to do with that. A shell can be invoked in a non-interactive way, for example to execute a pre-typed list of commands contained in a text file (a “shell script”). Think of a shell as the equivalent [...]
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