Advance Database Systems

Overview of RDBMS

Contents

• Database Definitions and Advantages of RDBMS

• Hierarchical Structure of DBMS

Why you Should take this Course

Jonathan Abrams Friendster fails

due to not optimized and efficient Database System

Mark Zuckerberg Facebook did not fail

due to optimized and efficient Database System

Database Definitions and Advantages of RDBMS

• An organized collection of information in computerized format.

• A collection of information organized and presented to serve a specific purpose.

• Thetermdatabaseisoftenincorrectlyreferredtoasasynonymfora“databasemanagementsystem(DBMS)”.

Data and Information• Data is the collection of raw facts collected from any specific

environment for a specific purpose.

• Data in itself doesnot show anything about its environment, so to get desired types of results from the data we transform it into information by applying certain processing on it.

• Once we have processed data using different methods; than data is converted into meaningful form and that form of the Data is called information.

• If we consider the data in the previous figure without the titles or the labels associated with the data (EmpName, age, salary) then; it is not much useful.

• However, after attaching these labels it brings some meanings to us, this meaningfulness is further increased when we associate some other labels, like the company name and the department name etc.

• So this is a very simple example of processing that we can do on the data to make it information.

Database Systems

• ThetermdatabasesystemisacombinationofdatabaseandtheDatabaseManagementSystem(DBMS).

• So, database is collection of meaningful data/information, DBMS is a tool to manage this data, and both jointly are called database system.

Why Use Models?

• Models can be useful when we want to examine or manage part of the real world.

• The costs of using a model are often considerably lower than the costs of using or experimenting with the real world itself.

• Examples:

• Network Model Simulation for an Organization in Packet Tracer

• World Map

• ERD for Relational Database Systems.

Hierarchical Structure of DBMS

Flat File Vs Relational Database System

• A flat file database is a database designed around a single table.

• The flat file design puts all database information in one table or list with field store present all parameters.

• A flat file may contain many fields, often with duplicate data that are prone to data corruption.

• If you decide to merge data between two flat files, you need to copy and paste relevant information from one file to the other.

• There is no automation between flat files.

• If you have two or more flat files that contain client addresses, for example, and a client moved, you would have to manually modify the address parameters in each file that contains that client’s information.

Relational Database System

• A relational database, on the other hand, incorporates multiple tables with methods for the tables to work together.

• The relationships between table data can be ordered, merged and displayed in database forms.

• These tables are to be normalized up to 3rd Normal Form (3-NF).