Tamilnadu Samacheer Kalvi 12th Computer Science Notes Chapter 11 Database Concepts Notes
Data and Information.
- Data are raw facts stored in a computer
- Information is formatted data
- Database is a repository collection of related data organized in a way that data can be easily accessed, managed and updated.
- Database can be a software or hardware based, with one sole purpose of storing data.
DBMS is a software that allows us to create, define and manipulate database, allowing users to store, process and analyze data easily.
Example: D base, Foxbase, Foxpro
Data Consistency means that data values are the same at all instances of a database
Components of DBMS:
The Database Management System can be divided into five major components namely
- Procedures / Methods
- Database Access Languages
The computer, hard disk, I/O channels for data, and any other physical component involved in storage of data
- This main component is a program that controls everything.
- The DBMS software is capable of understanding the Database Access Languages and interprets into database commands for execution.
It is that resource for which DBMS is designed. DBMS creation is to store and utilize data.
They are general instructions to use a database management system such as installation of DBMS, manage databases to take backups, report generation, etc
5. DataBase Access Languages:
They are the languages used to write commands to access, insert, update and delete data stored in any database. Examples of popular DBMS : Dbase, FoxPro
Normalization is a technique of organizing the data in the database.
Types of DBMS Users:
1. Database Administrators:
- Database Administrator or DBA is the one who manages the complete database management system.
- DBA takes care of the security of the DBMS, managing the license keys, managing user accounts and access etc.
2. Application Programmers or Software Developers:
This user group is involved in developing and designing the parts of DBMS.
3. End User:
- All modern applications, web or mobile, store user data.
- Applications are programmed in such a way that they collect user data and store the data on DBMS systems running on their server.
- End users are the one who store, retrieve, update and delete data.
4. Database Designers:
Database Designers are responsible for identifying the data to be stored in the database for choosing appropriate structures to represent and store the data.
Different types of a Data Models:
- Hierarchical Model
- Relational Model
- Network Database Model
- Entity Relationship Model
- Object Model.