Why did compiler did compiling?

How was the first compiler ever compiled???

What is a compiler (interpreter)?

A program that translates source code into object code. The compiler derives its name from the way it works, looking at the entire piece of source code and collecting and reorganizing the instructions. Thus, a compiler differs from an interpreter, which analyzes and executes each line of source code in succession, without looking at the entire program. The advantage of interpreters is that they can execute a program immediately. Compilers require some time before an executable program emerges. However, programs produced by compilers run much faster than the same programs executed by an interpreter.

Every high-level programming language (except strictly interpretive languages) comes with a compiler. In effect, the compiler is the language, because it defines which instructions are acceptable.

Evolution of Compiler

First was machine code: First programs written directly in the hardware's machine code

Then was assembler: A program written in machine code to interpret asm into machine code.

Then was a compiler: a set of programs (lexical analyser, parser linker etc) which could convert source code to assembler/machine code.

The first compiler was the A-0, created by Real Admiral Dr. Grace Murphy Hopper in 1949. It was made from assembly.

The A-O series of compilers translated symbolic mathematical code into machine code, and allowed the specification of call numbers assigned to the collected programming routines stored on magnetic tape. One could then simply specify the call numbers of the desired routines and the computer would "find them on the tape, bring them over and do the additions

http://forums.devshed.com/dev-shed-lounge-26/the-first-compiler-370155.html

http://www.linuxquestions.org/questions/programming-9/compiler-conundrum-which-came-first-a-compiler-or-its-source-code-132911/

http://www.webopedia.com/TERM/C/compiler.html

Part B of Assignment 3(SQL)

Steps to publish the report in Part A-

• Create 2 tables in the excel sheet with 2 different entities
  
• Go to www.db.zoho.com
• Choose import.xls or any of the remaining 3 options available
  
• Name the database
  
• Select data from each tables created in the excel sheet
• Press the create button(run it for each table)
• Now select new query table and type in the first query and save the same(do it for the remaining querries as well)
• Click on the view mode
  
• Run the publish tab and embed the same on the website for each querry
• A url will be generated
• Copied and posted at my blogg
• Publish the report

The queries that i have used are

• Table 1
  

SELECT "Last Name", "First Name" FROM "Student" where "Mess ID" like 'zaw'

• Table 2

SELECT "Last Name","First Name" From "Student" where "Fees/mth">=1500

• Table 3

SELECT "ID","Join Date","Fees/mth","Mess ID" from "Student", "Mess" where "Student"."Mess ID" = "Mess"."Mess ID"

SQL Assignment 3 table 3

SQL Assignment 3 table 2

SQL Assignment 3 table 1

SE Assignment 2 Part 1

Student		Book
Roll Number	P K	Book ISBN	P K
Name		Library Catalogue No.	F K
Email Address		Book Title
Phone Number		Book Author
Late fine o/s		Book Price
Library
Library Catalogue No.	P K
Roll Number	F K
Date issued
Date returned
Quality Of copy

My home

This is the link to my home on wikimapia.


http://www.wikimapia.org/#lat=26.185437&lon=91.76205&z=18&l=0&m=a&v=2&show=/6922220/Rajat_Kejriwal_s_Residence

System Architecture

A dialogue on System Architecture

Anjela, an MBA student in the first year and a friend, comes to me and asks whether I can give her an idea about system architecture. Following is a dialogue that took place between the two of us.

Me: System architecture provides a conceptual understanding of the parts of an operating system and the relationships among them. Sound system architecture is an important aspect of ensuring that the operating system is secure.

Anjela: So what does System Engineering stands for?

Me: System engineering refers to the design and implementation of production systems that require the integration of diverse and complex tasks, e.g. automobile assembly lines. It has two parts-

• · Database system
• · Application system

Anjela: Can you please explain to me the different tiers of system architecture?

Me: Sure why not. Let me go step by step-

• Programs/applications must not have data embedded into it no matter whether they are on the same hardware or not. This is the single tier architecture. For example say x=2, y=3, z= x+y. For every change in the values of x and y I have to update my program repeatedly. Now this becomes clumsy here as every time I have to go back and forward to complete the process. Instead, reading x, y from a certain range of values and then performing z will be a much simplified process.

• In the two tier architecture, data is stored in the central server and the applications on individual machines. It is also called the client-server architecture.

• The three tier architecture explains that with the introduction of a new product an organisations user interface remains the same whereas the fundamental change is in the business application area

• The multi tier architecture replaces application specific client with the web browser. It does not need dedicated client but only a web browser.

Anjela: So can we consolidate business application and the web server. What will be the outcome of this?

Me: The business application and web server can reside in the same machine removing some of the complexities which are-

• Managing multiple machines which is a challenge
• Management issue as to which one is easier to handle
• Reduction in the energy costs

Anjela: So don’t you think managing multiple tiers is a difficult task?

Me: Multiple applications can be complex to manage. But there are solutions-

• Invest in one big machine and standard software. The disadvantage here is that integration can be risky if the central database crashes.

• Club all the applications into one mega application which makes it easier to manage.

• Standard application ensures smooth functioning of the organisation. For example an ERP application

• Handling of specialist requirement is convenient

• Use WAN (Wide area network) instead of internet which brings in the threat of hackers. For a globalised company WAN will not work, we will need web browser.

Me: So have I been able to make you understand system architecture to some extent

Anjela: Yes! Certainly you have. Thank You.