MS Sql Server: Introduction To Database Concepts

1
SQL SERVER: AN INTRODUCTION TO DATABASE CONCEPTS

What is Data?
Data is any fact or statistic which can be operated on to
derive meaningful information. It is a raw fact.
Simply put:
Data is any raw fact
Eg: Size = 12 is data
Name = ‘Dennis’ is another data
We cannot derive conclusions directly from the data without processing them
Example of a Data

Why is Data important?
Data is important because every decision that happens in the world is based on some data
For example, if Jenny wants to buy a laptop, she needs the right data to make appropriate decision on the model. Like its cost, market value, etc.
Hence, every decision depends on the data
corresponding to it
WHICH SHALL I BUY?
Cost = $360
Cost = $450

Data in real-world
In the real world, data has become ubiquitous, i.e, data is every-where
All aspects of the modern business and domestic life-styles feed of huge amounts of data
The Amount of data is increasing exponentially and we needed a flexible, reliable and secure way to organize this data.
That is where Databases came to our rescue! 

What is a Database
A Database is a collection of interrelated data
For example:
A Database on students may contain the names, rollnumbers and GPAs of students in a university
A Zoo database may contain the names, RFID tag numbers, weights and ages of animals in a zoo
The List goes on
What is so special about a database?
Why can’t we just use files? (like text files and word documents). The Next slide answers this Qn.

Problems with files
Inconsistency
In a system, a user may use different applications and these may use different formats of data. Hence, interoperability between their data is difficult
For Example: Willy, Tim and Rose have been asked to write an essay on MJ, and they use different platforms, they’d have difficulty combining the Data into a single-final document: Incompatibilty
X
Willy
Uses MicrosoftWord
Tim
Uses WordStar
Rose
Uses Mellel, a Word processor for Macintosh systems

Problems with files
Data Redundancy
When handling large amount of data, there might be recurrences of data in case of files. This wastes memory space.
Integrity
The data is susceptible to corruption due to system failures
Concurrent Access anomalies
When many people try to write a piece of data concurrently – we’ll have problems in case of files
Security problem
Ill minded people may get access to our files if they are not secured properly.

Applications of DBMS in real life
The DBMS stands for: Database Management System
DBMS is a collection of related data (a database) and programs which allow users to work on that data (the management system)
DBMS eliminates the various problems that are associated with file storages
In real-life, DBMS have a wide spectrum of applications:
In Movie theatres for holding ticket reservation details
In Prisons for managing info about the prisoners
In Banks, to manage customer and account info

Database Features
A Database consists mainly of Tables
A Table is a set of values that is organized using a model of vertical columns (which are identified by their name) and horizontal rows.
A Table has a specified number of columns, but can have any number of rows.
Each row is identified by the values appearing in a particular column subset which has been identified as a candidate key.
Let’s take an example

Database Features
Example
Consider a database for the dreams that ‘George’ had this week. It has a table called ‘History’ where he stores the date and time at which he dreamt. This table will look as follows:
An ‘ATTRIBUTE’ which can uniquely identify a record in a table is called a ‘KEY’.
Eg: Dream Number
The ‘TYPE’ of data is called as ‘ATTRIBUTE’ or ‘FIELD’. Eg: Date, Time,etc
The ‘VALUES’ of a set of attributes, which define a unique object is a ‘RECORD’

Summary
Database Concepts
Data is a fact
Data is important
Database is a collection of related data
DBMS is used to manage database
Usage: Anyplace where data are concerned
A Database consists mainly of Tables
A Table consists of:
Records (Rows in a table)
Attributes (Columns in a table)
Keys (Used to uniquely identify a record in a table)
End

Visit more self help tutorials
Pick a tutorial of your choice and browse through it at your own pace.
The tutorials section is free, self-guiding and will not involve any additional support.
Visit us at www.dataminingtools.net

http://www.slideshare.net	19
http://translate.googleusercontent.com	1
http://www.dataminingtools.net	1

MS Sql Server: Introduction To Database Concepts

by DataminingTools Inc on Dec 13, 2009

Accessibility

Categories

Tags

Upload Details

Usage Rights

3 Embeds 21

Statistics

MS Sql Server: Introduction To Database Concepts — Presentation Transcript