The architecture of a Database Management System (DBMS) is crucial for its design, development, implementation, and maintenance. Choosing the right DBMS architecture ensures quick and secure access to critical business information. The architecture depends on the computer system and how users connect to the database.
Client-server architecture is common in environments with many PCs, web servers, and database servers connected via networks. In this setup:
⇒ Clients request services from the server.
⇒ The server provides the requested services to the clients.
Single-tier Architecture
Two-tier Architecture
Three-tier Architecture
⇒ The database is directly available to the user.
⇒ The client, server, and database are on the same machine.
⇒ Users can directly interact with the DBMS.
⇒ Changes are directly applied to the database.
⇒ No network connection is needed.
⇒ Useful for local applications where data doesn’t change frequently and no multiple users access the system.
⇒ Rarely used in production.
⇒ Similar to client-server architecture.
⇒ Applications on the client communicate directly with the database server.
⇒ Uses Application Programming Interfaces (APIs) like ODBC and JDBC.
⇒ Uses Application Programming Interfaces (APIs) like ODBC and JDBC.
⇒ The server handles query processing and transaction management.
⇒ Common in organizations where multiple clients access the database server directly (e.g., railway reservation counters).
Advantages:
⇒ Direct and faster communication.
⇒ Easier maintenance and understanding.
⇒ Compatible with existing systems.
Disadvantages:
⇒ Poor performance with a large number of users.
⇒ Less secure as clients can directly access the server.
⇒ Adds an Application Server layer between the client and the server.
⇒ Clients do not communicate directly with the server.
⇒ The client interacts with the application server, which then communicates with the database server.
⇒ This architecture is used in large web applications.
⇒ The application is divided into three separate logical layers.
Advantages:
⇒ Enhanced scalability due to distributed deployment of application servers.
⇒ Improved data integrity by avoiding direct client-server interaction.
⇒ Increased security by preventing unauthorized data access.
Disadvantages:
⇒ Increased complexity in implementation and communication due to the middle layer.
