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 → 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 [...]
Continue reading → In Linux, if a program crashes, it often dumps a “core ” into your home directory. This is accompanied by an appropriate message. A core is a memory image and is a debugging tool. If you are a user who does not intend to debug the program, you may simply delete the core : Rm [...]
Continue reading → Sometimes, a simple GROUP BY clause just isn’t enough in a query. Once you generate a report of, let’s say, average salary by department or the standard deviation of sick days by job title, you often must run a second query that calculates the average salary or standard deviation across the entire set of employees. [...]
Continue reading → Data mining has many and varied fields of application some of which are listed below. Retail/Marketing 1. Identify buying patterns from customers 2. Find associations among customer demographic characteristics 3. Predict response to mailing campaigns 4. Markets analysis Banking 1. Detect patterns of fraudulent credit card use 2. Identify ‘loyal’ customers 3. Predict customers likely [...]
Continue reading → 1.Growing Data Volume The main reason for necessity of automated computer systems for intelligent data analysis is the enormous volume of existing and newly appearing data that require processing. The amount of data accumulated each day by various business, scientific,and governmental organizations around the world is daunting. 2. Limitations of Human Analysis Two other problems [...]
Continue reading →