DBMS Fundamentals
Learn about Database Management Systems, their components, and architecture.
Database Systems
Types & Components
Explore different types of DBMS and their essential components.
Architecture
Understanding the three-level architecture and data independence.
Users & Tools
Different types of database users and available management tools.
Introduction
A Database Management System (DBMS) is a software package designed to store, manage, and facilitate access to databases. When data in an information system is stored in a single structure, it’s called a database.
Components of a Database System
- Machines where databases are stored
- Include mass storage units for this purpose
- The database management system
- Application that enables database handling
- Includes stored data
- Metadata (data describing what’s stored)
- End users: Use applications that work with database data
- Developers: Create programs that provide database views
- Administrators (DBAs): Manage maintenance, security, and performance of the database
DBMS Objectives
The main objectives of a DBMS include:
- Providing tools for data creation and specification
- Managing physical structure in storage units
- Offering data manipulation tools
- Ensuring disaster recovery capabilities
- Enabling backup creation
- Managing database communications
- Supporting external data schema applications
- Facilitating database installation
- Enabling data import/export
Advantages of DBMS
Architecture Levels
The ANSI/SPARC architecture defines three levels:
-
External Level
- User views of the database
- Partial or transformed data views
-
Conceptual Level
- Global database vision
- Defines records, associations, and constraints
-
Internal Level
- Corresponds to files, indexes
- Data defined at operating system level
Types of DBMS
Commercial
Paid and Private
Examples:
- PostgreSQL
- MySQL
- MariaDB
- SQLite
- Apache Derby
Free
Free and Open-Source
Examples:
- Oracle
- Microsoft SQL Server
- IBM DB2
- Sybase ASE
- Microsoft Access
