Basics of Database Management System
Data is a raw and isolated facts about an entity. Most importantly, it is able to recorded.
For example: Text, Audio, Video, Image etc.
In short Information is a processed, meaning full and usable data.
Database is a collection of similar or related data.
For example: YouTube for video, Instagram for image, Music player for audio etc.
Database Management System:
Database Management System is a software or tools. In addition, it allow to create, manipulate and delete database.
For example: MySQL, Oracle etc.
Why Database is important:
Database overcomes disadvantages of file system.
Disadvantages of file system:
1. Data redundancy: Data redundancy means same data or information present in different file.
2. Data inconsistency: Data redundancy means same data or information present in different file and each information or data having different values.
For example: i=50 in a file and i=5 in another file.
3. Concurrent-access anomalies: It means issue in multiple operations at a time.
4. Difficulty in accessing data.
5. Security problem.
6. Integrity problem.
7. Atomicity problem.
OLAP vs OLTP:
Large database divided into two different parts (OLAP and OLTP) for fast memory access.
Online Analytical Processing (OLAP):
- Online Analytical Processing having historical data.
- It is large in size (in TB or PB).
- In Online Analytical Processing (OLAP) only read operations are performed.
- In it data mining or decision-making operations are performed.
- OLAP is deal by CEO, MD, CM, etc.
Online Transaction Processing (OLTP):
- Online Transaction Processing having current data.
- It is small in size (in MB or GB).
- In Online Transaction Processing (OLTP) both read and write operations are performed.
- In it day to day operations are performed.
- Online Transaction Processing are deal by clerk, manager etc.
Applications of database:
E-commerce: Database is used in e-commerce web sites to manage user profile data, order details, sellers details, product details etc.
Banking system: Database is used in banking system to manage customers details (withdraw, deposit, loan etc).
And also used in university, railway, airlines etc.
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