Today was my first day in class. I woke up bit late as usual. The class was at sharp 7:00 AM. But I reached at 7:10 AM. Sir was taking introduction from all students. As I entered Sir asked me to introduce my self to class. Then Sir gave introduction about himself and Oracle. He started from scratch and first thing he taught was "what is data?" Initially I was bit nervous, but as the time passed I calmed down. Sir involves you so much that you never come to how time has passed. At the end it was a nice day.
Now lets come to the topic of Oracle. I will share with you what I learned today.
As I told you first thing that Sir taught us was, What is Data?
He explained it beautifully. The final conclusion was that Data is defined as Value of Property of Entity.
Then Sir taught what is Database?
In short I can just tell you that it is organisation of data.
There exited a data base called Network or hierarchical Data base. Y2K problem was because of this database only.
Explanation: Suppose you store some data. Now because you have stored the data it is quite obvious that you will need this data some time or the other. This means that method to access the data must be convinient. Suppose you want to store information about a person showing his Name, Age, Sex, Quallification, Job, Income etc... And you store it in following fashion. Suppose that you define that charachers from 1 to 20 are for Name, charachters 21 to 25 are for age, charachters 25 to 30 are for sex, charachers 30 to 50 are for Qualification so on and so forth. It just means that you have assigned particular space for particular entity and you will store that entity there only. Problem comes when you come accross such a entity that it needs more space than the space assigned by you. Take for example it can be name of any person or may be his qualification. Or it may so happen that particular person changes his name or adds more feathers to his cap there by my making his qualification more healthy. In that case if you will change one entity then other entities will also change leading to lot of chaos. Hence this database failed.
What is Database Management?
Set of protocols ( rules ) that your database follows is called database managment.
This is what I learned today.
Hey I just came to know today that All students who have attendence less than 75% won't be allowed to sit for NU exam and also will have to pay the fine. Its all bullshit. God is really testing me from all angles. But I am prepared for it.