03 architecture

Database Architecture:

1. representation of DBMS design.
2. It helps to design, develop, implement, and maintain DBMS
3. A DBMS architecture allows us to divide the database system into individual , modifiable components
4. A Database stores critical information
5. helps access data quickly and securely
6. Therefore, selecting the correct Architecture of DBMS helps in easy and efficient data management.
7. The DBMS design depends upon its architecture
8. The client/server architecture consists of many PCs and a workstation connected in a network.
9. The basic client/server architecture is used to deal with a large number of PCs, web servers, database servers and other components that are connected with networks.
10. DBMS architecture depends upon how users are connected to the database.

Types of DBMS Architecture

• 1-Tier/single tier Architecture

1. Simplest DB architecture where database is directly available to the user
2. the client, server, and the Database are all present on the same machine.
3. For Example- To learn SQL we set up an SQL server and the database on the local system.
4. Can directly interact with the relational database and execute operations.
5. Used for development of the local application, where programmers can directly communicate with the database for the quick response.
6. The industry won’t use this architecture they logically go for 2-Tier and 3-Tier Architecture.

2-Tier Architecture

1. similar to a basic client-server model.
2. The application at the client’s end directly communicates with the database at the server side by establishing a connection
3. APIs like ODBC and JDBC are used for this interaction
4. presentation layer runs on a client (PC, Mobile), and data is stored on a server called the second tier
5. maintenance and understanding are easier, compatible with existing systems
6. However, this model gives poor performance when there are a large number of users.
7. In the above 2 Tier client-server architecture, we can see that one server is connected with clients 1, 2, and 3.

3-Tier Architecture

1. most popular client server architecture in DBMS
2. the development and maintenance of functional processes, logic, data access, data storage, and user interface is done independently as separate modules
3. Three Tier architecture contains a presentation layer (your PC, Tablet, Mobile, etc.), an application layer (server), and a database server.
4. application layer :
   1. communicating the user’s request to the DBMS system and send the response from the DBMS to the user.
   2. another layer between the client and the server
   3. processes functional logic, constraint, and rules before passing data to the user
5. its design is an extension of the 2-tier client server architecture
6. used in the case of large web applications.
7. • Enhanced scalability: due to distributed deployment of application servers. Now, individual connections need not be made between client and server.
8. • Data Integrity: is maintained. Since there is a middle layer between the client and the server, data corruption can be avoided/removed.
9. Security is improved. This type of model prevents direct interaction of the client with the server thereby reducing access to unauthorized data.