Green Computing

Requirements:

• A user friendly online application
• The application to be linked with the company’s database
• The sales person has to select his id and enter data such as product and quantity
• If the stock is available the transaction should proceed and using the unit-price and quantity, the order value should be calculated else the sales person should receive an appropriate message about the insufficient stock
• As the orders get placed, the inventory should get decreased from the main database

Inventory

Inventory View

Order

Order View

A compiler is a computer program (or set of programs) that translates text written in a computer language (the source language) into another computer language (the target language). The original sequence is usually called the source code and the output called object code. Commonly the output has a form suitable for processing by other programs (e.g., a linker), but it may be a human-readable text file.

The most common reason for wanting to translate source code is to create an executable program. The name “compiler” is primarily used for programs that translate source code from a high-level programming language to a lower level language (e.g., assembly language or machine language). A program that translates from a low level language to a higher level one is a decompiler. A program that translates between high-level languages is usually called a language translator, source to source translator, or language converter. A language rewriter is usually a program that translates the form of expressions without a change of language.

Software for early computers was exclusively written in assembly language for many years. Higher level programming languages were not invented until the benefits of being able to reuse software on different kinds of CPUs started to become significantly greater than the cost of writing a compiler. The very limited memory capacity of early computers also created many technical problems when implementing a compiler.

Towards the end of the 1950s, machine-independent programming languages were first proposed. Subsequently, several experimental compilers were developed. The first compiler was written by Grace Hopper, in 1952, for the A-0 programming language. The FORTRAN team led by John Backus at IBM is generally credited as having introduced the first complete compiler, in 1957. COBOL was an early language to be compiled on multiple architectures, in 1960.

In many application domains the idea of using a higher level language quickly caught on. Because of the expanding functionality supported by newer programming languages and the increasing complexity of computer architectures, compilers have become more and more complex.

Early compilers were written in assembly language. The first self-hosting compiler — capable of compiling its own source code in a high-level language — was created for Lisp by Hart and Levin at MIT in 1962. Since the 1970s it has become common practice to implement a compiler in the language it compiles, although both Pascal and C have been popular choices for implementation language. Building a self-hosting compiler is a bootstrapping problem — the first such compiler for a language must be compiled either by a compiler written in a different language, or (as in Hart and Levin’s Lisp compiler) compiled by running the compiler in an interpreter.

source: wikipedia      

 Having worked on RDBMS like Oracle and MySQL, Zoho was amazingly easy to use. Finally there is something that is far more easy to use and maintain. Now you can get rid of the cumbersome task of installing and maintaining an RDBMS since Zoho is completely web-enabled. It beautifully personifies a Multi-tier Systems Architecture. Creating tables was never so easier, as one can directly import tables from any spread sheet or use an already available template. The same holds true for firing queries, where you have an entire list of tables and columns on one side which would make the process of selection easier and faster.

The most fasinating part is the reports. One can generate reports on the data and publish them on the web. These reports can be given access control which would be very critical for organizations since different business units at various levels would require different reports and also in different formats. Yes, since it is a new vendor it will take people time to get used to fully web-enabled application with bandwidth constraints and the forever present security issues of the web. But once it gets recognition, it has the capability to threaten the big players of this industry.

query_reports

          It was evening time and I was about to do what I do the best i.e. sleep when someone banged my door. It was Enayath with my other class mates- Abhishek, Silky and Raj. They had missed the 1^st S.E. class and hence wanted me to explain what Dr. Mukerjee had taught.

Abhishek: Kartik, you very well know how good we are in IT so I want you to explain us Systems Architecture slide by slide.

Me: Okay I will try

Everyone opens Dr. Mukerjee’s presentation and I not so confidently start to explain.

Me: Just like a computer program has two parts- data structures and algorithms, an Information System has two parts- database and applications. And among the various architectures that we are about to learn, the basic or the primary architecture is one in which we separate the data from the applications.

Enayath: But Kartik, how do you separate these two?

Me: Take the example of a CLASS in a programming language which was taught by Dr. Mitra from HP. If you remember he taught us the concept of modular programming in which you have various classes and each class comprises attributes and operations as separate entities.

Enayath: Yes, now I got it.

Me: Now let us understand the various other architectures- two tier, three tier and multitier. A two tier also known as the client-server architecture is one in which the data resides in the server side and the applications are on the client side. For example our CMIE server which is the database lies on the server side and we have its frontend in our laptops. In three tier architecture you separate your business critical applications at the server side.

Silky: Kartik, I did not get the concept of this three tier architecture. Can you please elaborate on this?

Me: Okay, take an example of a banking application. A clerk would only require a simple frontend that has the accounting details. He does not have and is not supposed to a have a complex and a critical application like credit verification. So this application resides in the server which can only be accessed by the authorised person.

Silky: Okay now it is clear.

Me: Now if a company web-enables the entire process, the clients would only require a web-browser via which he would get his application. And for this the company would require a web server. This architecture is known as a multitier architecture.

Raj: But Kartik don’t you think that there will be security issues if opt for using internet?

Me: Yes Raj, you are right. Internet is a public network and is prone to hacker attacks and to counter this you would require firewalls, antivirus software etc. But we have already learned the huge benefits of web services to make up for these security issues. Moreover Dr. Mukerjee explained us the advantages of using an integrated database and ERP package.

Abhishek: Thank you Kartik, I think we already know the concepts of RDBMS and ERP which you taught us for ITM-2 end term exam. So let us not waste your precious time which I am sure you will spend for sleeping. So you can sleep happily now.

Me: Thank you Abhishek. You very well understand that I am a hardcore Garfield fan so I should sleep now.