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EVOLUTION OF MAN

CONTRIBUTED BY - Denny Philip (IInd BCA) -

JDBC-API CLIENT SEVER MODEL

Introduction:

The Java Database Connectivity Application Programming Interface (JDBC) is asset of specifications that defines how an application opens a connection, communicates with database. It defines how an application opens a connection with a database, executes SQL statements and retrieves the result.

JAVA SOFT developed JDBC-API. Many of the JDBC-API concepts are taken from other sources particularly Microsoft’s ODBC, ODNC & JDBC can ba called siblings. The major difference being ODBC is written in C. The pointers are made use extensively. But java does not have pointers. The JDBC-API is much smaller and easier to implement as compared to ODBC. JDBC was designed to be compact & focused only on the execution of SQL statements and there by retrieving the result, but ODBC has multiple mechanism for performing a single task and has additional data handling capabilities.

The figure given below depicts the functioning of JDBC-API.

JDBC-API defines the following.

Ø How the info is to be presented to the application.

Ø Tells the application what it can expect from the database.

Basic Steps to JDBC

These are the six steps using JDBC-API to access a database. Each step is important and is required to complete a database transaction. The six steps are mentioned below.

Ø Import JAVA SQL package.

Ø Load and register the driver

Ø Establishing connection to the database server

Ø Reaching a statement

Ø Executing the statement and retrieving the results

Ø Closing the statement and connection.

Two Tier Client-server model :

The architecture of nay client server environment is by default a two-tier system. The client is the first tier and the server is the second tier. In a two tier JDBC environment, the database application is the client and the DBMS is the server. The client communicates with the server directly.

Advantages of using a Two-Tier database system:

Ø It is the least complicated system to implement.

Ø This architecture maintains a constant connection between the client and database.

Ø This system is usually faster than a three tier implementation.

Disadvantages of using a Two-Tier system :

Ø Most of the drivers require the native libraries to be loaded on the client machine.

Ø Local configuration has to be maintained for native code.

Ø Applets can open up connection to the server from which they are downloaded.

Three-Tier Client Server model :

In this system a third server is employed to handle request from the client and then pass them to the database server. His server acts as a proxy for all client requests. This model has the advantage of separating the database server from the web-server. All the client requests are routed through the proxy server thereby creating a more secure environment for the database. The driver translates the request into a Network protocol and then requests via a proxy server.

CONTRIBUTED BY: Ms. M. Ajitha Purnima M.Sc.M.Phil (lecturer)

HOW DREAMS BECOME GOALS

It is wonderful to have a dream. It can also be wonderful to have a goal. True, there is a school of thought that maintains we should not need goals. My own perception of this viewpoint is that it applies to those goal-lists that time management folks advocate. They can be useful, or a burden, depending on where you are in your personal growth. Today I am looking at the difference between having a dream and having a goal.

A dream is goal without legs. It is a wonderful thing to have, can be the guiding passion of your life, but unless you clarify it and give it the legs to move toward you, getting there is going to be very much a matter of luck. To transform a dream into a reachable goal you must clarify it, provide the details, make it so clear that you can see it,feel it, know what you will feel like when you get there. This works for you in many ways.

* It clarifies what you want to the point that you will always be attuned to anything that is relevant. Opportunities will not pass you by unnoticed.

* It shows you what you need to do to get there, step by action step.

* It makes false detours and dead ends less likely to distract you.

* And perhaps the images you carry in your mind and heart will echo out to the universe for manifestation.

The clearer and more vivid the image, the more likely are all of these things to happen. As an illustration, I will use a dream someone might have regarding a career, but the principle remains the same whatever the nature of your dream. Let’s suppose that you yearn to work outdoors and close to nature. Someone asks you to tell them more, but you can’t. You don’t know. All you know is that you want to work outdoors and close to nature. This is a dream. Why is it not a goal? Because it is not specific. That description could fit many occupations, including park ranger, beach bum, safari tour guide, farmer, landscape gardener, migrant worker, beekeeper or many more.

There is saying, “Be careful what you pray for, because you eill surely get it, but not necessarily in the form, and at the time, that you expected.” This applies particularly when you thoughts are not specific. Imagine putting out a prayer and a wish to the universe that you find a job that involves being in the outdoors and close to nature, and having your prayer and answered by falling into a job as a beekeeper…. When you are truly terrified of insects! This is not bad luck, it is bad management. Bad management of your own desires and intentions. Both your own unconscious and the universe need clear direction before they can begin to manifest a path, let alone get results. If you are to harness your own energy and that of the universe so as to bring your dream into reality, you need first to create it in imagination.

Okay, let’s start again. You want a job working in the outdoors and close to nature. Buy yourself one of the many books on the subject of career choice that will help you it CLARIFY. Ask yourself those annoying questions that any career counselor would ask you. What sort of work do you want to be doing? Do you like people? Do you like animals? What kind of animals? (There’s a big difference between working with a friendly kitty-cat and working with large wild animals who would prefer that you not be sharing their space.) Do you enjoy structure or freedom? And be careful of this one, because we all think we want freedom until we find ourselves working alone and without guidelines or supervision. For some people this works fine, for others it is far more threatening that they had realized.

For every image that comes to you, follow it, ask yourself how it fits, how you will work with it, and what comes next, until your dream is as vivid and enthralling as a five star movie. Know in your heart that this is what you want to be with your life, that it is a job you will enjoy so much that you’d love to do it even it you didn’t have to earn a living. Then put THAT image out there for magnification. This time there will be no mistakes.

When I write “put it out there for manifestation”. I am not saying that you then sit back and wait. One of my mother’s saying is “pray as if it all depends on God, and then work as if it all depends on you.” It is good advice. But now, with your mental picture in place, you know what it is that you are working towards. What you DON’T need to put out to the universe is exactly how this manifestation has to happen. If you do, then you are limiting the way in which you and your god can come together. In truth there are more paths to your goal than you can imagine. It is fine to choose one that you will work on, with a couple of fall backs in case of obstacles, but be careful to remain clear that these are not the only alternatives. Whatever it is that you seek, it may be manifested in ways beyond your wildest dream.

Contributed by: Ms. Veena Prathiba (Lecturer)