SQL Week 1 Questions

Oracle Data Types 1 of 4

Nice! I officially had a Problem Exists Between Keyboard and Chair (PEBCAC) moment.  I erased the first question section :).
 

In an effort to interact with my blog readers and encourage a healthy learning atmosphere, I will post a few SQL questions every two weeks. At the end of each period, I will answer the questions posted.

 

The first four quiz entries will attempt to cover Oracle data types.  Understanding them is vital if you want to design and develop good databases and code.

 

Questions:

 

1. Describe the number data type. What are its arguments? How and when should it be used?
2. Describe the varchar2 data type with its arguments.
3. Describe the date and timestamp data types.  Give examples of how they should be used.

SQL Entry - E.F. Codd

It would be inappropriate to begin a dialogue on SQL without discussing doctor Edgar Frank Codd a.k.a. E.F. Codd. During the 1960's and 1970's doctor Codd worked at IBM and produced a white paper called, "A Relational Model of Data for Large Shared Data Banks." IBM made no efforts to implement Codd's theories even though its competitors began to.

In an effort to defend his views, Codd showed his theories to IBM customers who began to demand of IBM, that his theories be implemented. It was then that IBM began its "Future Systems" project which was intended to appease its customers more than Codd. It put in charge of the project, developers who were not thoroughly familiar with Codd's theories and isolated Codd from them. As a result, the team did not fully take advantage of Codd's relational language; however, their SEQUEL language was far superior to its predecessory query methods. Mr. Larry Ellison was so impressed with the new language that he adopted it. He then rapidly integrated it into his Oracle Relational Database Management System (RDBMS) and renamed it to SQL because SEQUEL had already been trademarked by IBM.

In the end, Oracle released its fully functional RDMBS prior to IBM's release of IMS/DB. Larry's continued effort to improve and expand his database and business systems has created one of the largest technology companies in the world. His database system continues to be "best of breed", offering many SQL functions and packages that greatly simplify the Database Administrator's day-to-day tasks.

Codd's Topics of Interest:

Codd: 12 RDBMS Rules

Codd: Theories on Database Normalization

Codd: Theories on OLAP Cubes

I’ve witnessed a lot of changes in the Information Technology (IT) industry, having been a computer nerd since the Commodore Personal Electronic Transactor (PET) days. They were screamers! with 4K of ram, tape drive, and a 9” green-screen.

It’s kind of funny, games “back-in-the-day” consisted of a “K” - knight poking around on an empty green screen, looking for a “D” - dragon. The weapon of choice was the “->” symbol. And, the fighting action was a display of ratios from random dice rolls and a counter representing how much life the “K” and “D” had left.

My buddies and I thought we had reached enlightenment when game programers started using box symbols to draw halls and rooms. The “K” still chased monsters around a green screen, but we now had “D” - dragons, “G” - goblins, “M” - mummies, and “Z” - zombies to deal with.

Our librarian had a strict policy of not allowing games on computers. So, we would sneak the games in on our Walkman tape players. Then, while one of us played lookout, the others would enjoy a lunch-hour of bliss as we moved our “K”’s around the green screen, rescuing those memory bits from peril.

Few things remain constant as new programming/hardware methods are introduced and grandfathered within 6 months of their entrance. One of the things that seems constant is the database industry. Mind you, changes happen, but the methods used and best practices introduced endure. That is one of the major reasons I chose the database industry as my IT carer focus.