Compiler

A compiler is a specialized computer program that converts source code written in one programming language into another language, usually machine language (also called machine code) so that it can be understood by processors (i.e., logic chips).

Source code is the version of software (usually an application program or an operating system) as it is originally written (i.e., typed into a computer) by a human in plain text (i.e., human readable alphanumeric characters). Source code can be written in any of numerous programming languages, some of the most popular of which are C, C++, Java, Perl, PHP, Python and Tcl/Tk. The output of a compiler is referred to as object code.

Brief History

The first compiler was developed in 1952 by Grace Hopper, a pioneering computer scientist. She said that she invented it because she was lazy and wished that “the programmer may return to being a mathematician.” The first compiler was written using A-0 programming language.

A-0 programming language.

The A-0 system, written by Grace Hopper in 1951 and 1952 for the UNIVAC I, was the first compiler ever developed for an electronic computer.^[1] The A-0 functioned more as a loader or linker than the modern notion of a compiler. A program was specified as a sequence of subroutines and arguments. The subroutines were identified by a numeric code and the arguments to the subroutines were written directly after each subroutine code. The A-0 system converted the specification into machine code that could be fed into the computer a second time to execute the program.

The A-0 system was followed by the A-1, A-2, A-3 (released as ARITH-MATIC), AT-3 (released as MATH-MATIC) and B-0 (released as FLOW-MATIC).

Running a Query

Hello Friends this is as simple as playing a game like ‘Moto GP’. Just read the below given Points and you will be fluent in running queries.

·         Go to http://db.Zoho.com.

·         Now enter your ID and create your database .You can either copy paste the data or yourself create it in the template.

·         Now, in my case I have created 2 data base with names like ‘Employee’ and ‘Department’, you can give any of the random names.

·           Now I want to run a Query to join these 2 databases, in order to do that i have to run a simple query like select name, employee……. from employee database and from department database and put a equal sign in between only if there’s something common in the two databases or one is attribute is a primary key 1 database and foreign key to the another.

·         My second Query was to do the avg. of the salaries of the persons working in a company ’xyz’ , here I selected  Avg. function from the SQL function  given in the insert column and ran the query it gave me the avg. of the salaries of all the 19 persons working in the company.

·         My third Query was to select people who were either have a employee designation as ‘Clerk or were having their age greater then 30, here I selected the attributes required for the final table and gave an or option in the query got the final table.

So, now you can see what a miracle this SQL language is, easy to understand and fast to work with……

Work on it and enjoy……..

ALSO VISIT:

• http://db.zoho.com/ZDBDataSheetView.cc?DBID=19235000000003491&OBJID=19235000000003668

To view my tables

Entities: Book, Subject, Student and Account information

Attributes: Book ISBN No., Book Title, Book Publisher Name, Book Publishing Date and Year, Book Pages, Subject Category ID, Subject Name, Student ID, Student Name, Student Address, Student E-mail ID, Student Telephone No., Account ID, Borrowing, Returning, Fine Collection.

UnNormalized Entity

Normalized Entity

SUBJECT

STUDENT

Account Information

BOOK

It was a summer evening when my Servant’s son (chotu) who is studying in class 12 came up to me and enquired about the information system engineering and its various types. Here goes the discussion:

Chotu: What is information system engineering? Is it a difficult thing to understand?

I: come on chotu it’s as easy as understanding how to wash clothes in a washing machine. System is a set of interacting or interdependent entity, real or abstract, forming an integrated whole and engineering means to engineer something i.e. to make something happen. So system engineering is nothing but make your system work efficiently and effectively by engineering it.

Chotu: Is there any relationship between Computer science and information system engineering?

I: Well that’s a good question, see in Computer science we use Programs which is nothing but a joint venture between Algorithm and Data structure which describes what is to be processed and how is it processed, same is with Information system engineering the only difference being instead of algorithm and data structure we look for database and applications.

Chotu: Is there any important thing to look out for while designing an Information system?

I: The only important thing to look out for while designing an information system is that the data and application should not be merged i.e. data should not be embedded in the application.

Chotu: How many type of system architecture are there and which one is the best in terms of advantages it provides to the users?

I: There are four types of system architecture, to name them:

1.) Single tier architecture

2.) Two tier architecture

3.) Three tier architecture

4.) Multiple tier architecture

There is no such thing called best in the information system architecture, it all depends on the business need. for example if you find that your data is very small and applications need not be changed very frequently also data is required only to your office people you require single tier architecture, if applications need to be changed frequently you require three tier architecture where business application and user interface are separated from each other.

Chotu: Why is business and user interface separated from each other in three tier architecture and is there any advantage attached to this type of arrangement??

I: yes, kindly understand one thing an application consist of two parts:

• Business application
• User interface

Business application deals with hard business logic and this need change frequently whereas user interface is just used for making things look good, for e.g. Smiley. and this application changes once in a decade so business application and user interface are separated from each other so that changes can only be done at one location without disturbing others.

Chotu: If I want to make my data Web enabled what are the changes I have to make in my architecture?

I: For making your data web enabled you just have to connect your users to the internet and yes important thing is you need to protect your data from intruders. Firewall is the most common type of protection used against intruders.

Chotu: How do we manage complexity in corporate database and where is this so called ERP system employed and why has it become so popular in the whole architecture?

I: There are many types of management systems in use today but the most common and widely used is relational database management system (RDBMS).

About ERP yes it’s the hot topic today and is employed in the database sides its main advantage is it provides you the flexibility to use any of the module you requires and for some special application you require to write your own codes.

Chotu: That’s good

I: I think you might have understood the thing and now there might no such problem regarding system architecture.

Chotu: yes I understood it and tomorrow I will be explaining it in my class as this is our home assignment.

I: good, I think you are turning shrewd now- a -days.