Here, we will learn about the architecture of Database Management Systems. The DBMS architecture allows DBMS to perform the functions effectively and efficiently. The whole design and maintenance of the DBMS depend upon its architecture. Due to its architecture, DBMS can be easily designed as centralized or decentralized or hierarchical.
The architecture of the database management system can be seen as either single or multi-tier. But, logically it can be of the following three types:
- 1-tier Architecture
- 2-tier Architecture
- 3-tier Architecture
This type of DBMS architecture is simple and rarely used in production. In 1-tier architecture, DBMS users directly interact with the database for storing and managing the data in the databases. This type of architecture does not provide any handy tools for users who want to use the database management system.
It is basically used for developing the local applications, where programmers directly interact with the database for quick responses.
This type of architecture depends on client-server architecture. In 2-tier architecture, the client-side application directly interacts with the database systems at the server-side. In this architecture, applications are present at the client machine, and the database system is present at the server machine.
Both the machines (Client and Server) interact with each other by using an Application Programming Interface like ODBC and JDBC. 2-tier Architecture provides extra security to the database management system and also provides authentication checks for the applications.
3-tier Architecture is the most popular architecture and helps to design a database effectively. In 3-tier architecture, the client does not directly interact with the server. There is another layer present between the client layer and the server layer which is called the application layer.
In this type of architecture, the client-side application interacts with the application layer which further interacts with the database system at the server-side.
Following are the various features of this architecture, which make it the most widely used DBMS architecture:
1. Data Security,
2. Data Backup,
3. Data Recovery,
4. Concurrency control, and
5. Low Data Redundancy.
Following are the three layers which are used in 3-tier Architecture:
1. Client or User Layer
This layer of the 3-tier architecture is also known as the presentation layer. This layer basically consists of a user interface. It is the topmost layer in this architecture where the users send a request to the server-side by the application layer. This layer provides the GUI to the end-users who want to use the database.
2. Application Layer
This layer of the 3-tier architecture is also known as the business logic layer. This layer acts as an intermediate layer between the client (User) and server (Database) layer. For each end-user, this type of layer shows the abstracted view of the database. This layer processes function logic, rules, and constraints before passing the data to the user and the database.
3. Database Layer
It is that layer of the 3-tier architecture where the data and information are actually stored. The data in this layer is managed and accessed with the help of various programs such as MS-SQL, MySQL, Oracle, and MongoDB.