DBMS Architecture

DBMS architecture helps in design, development, implementation, and maintenance of a database. A database stores critical information for a business. Selecting the correct Database Architecture helps in quick and secure access to this data.

1 Tier Architecture

• The simplest of Database Architecture are 1 tier where the Client, Server, and Database all reside on the same machine.
• Anytime you install a DB in your system and access it to practise SQL queries it is 1 tier architecture. But such architecture is rarely used in production.

Advantages of 1 Tier Architecture

• Simplicity
• Performance
• Cost-Effective
• Ease of Maintenance
• Development Speed
• No Network Dependency 

Disadvantages

• Lack of Scalability
• Limited Reusability
• Performance Bottlenecks
• Poor Maintainability
• Single Point of Failure

2 Tier Architecture

A two-tier architecture is a database architecture where:

1. Presentation layer runs on a client (PC, Mobile, Tablet, etc.)
2. Data is stored on a Server.

• An application interface which is called ODBC (Open Database Connectivity) an API which allows the client-side program to call the DBMS.
• Today most of the DBMS offers ODBC drivers for their DBMS. 2 tier architecture provides added security to the DBMS as it is not exposed to the end user directly.

Advantages of a Two-Tier Architecture 

• Simplicity
• Performance
• Cost-Effective
• Quick Development
• Ease of Maintenance
• Better Control

Disadvantages

• Scalability Issuess
• Network Load
• Security Concerns
• Complex Deployment

3 Tier Architecture

3-tier schema is an extension of the 2-tier architecture. 3-tier architecture has following layers:

1. Presentation layer (your PC, Tablet, Mobile, etc.)
2. Application layer (server)
3. Database Server

This DBMS architecture contains an Application layer between the user and the DBMS, which is responsible for communicating the user's request to the DBMS system and send the response from the DBMS to the user.

The application layer (business logic layer) also processes functional logic, constraint, and rules before passing data to the user or down to the DBMS Three tier architecture is the most popular DBMS architecture.

Advantages of Three-Tier architecture

• Scalability
• Maintainability
• Reusability
• Flexibility
• Improved Security
• Enhanced Performance

Disdavantages

• Complexity
• Higher Cost
• Performance Overhead
• Development Time

Example of Three-tier Architecture is any large website on the internet.