DBMS Architecture

 

Ø  A Database Architecture is a representation of DBMS design.

Ø  It helps to design, develop, implement, and maintain the database management system.

Ø  A DBMS architecture allows dividing the database system into individual components that can be independently modified, changed, replaced, and altered.

Ø  It also helps to understand the components of a database.

Ø  A Database stores critical information and helps access data quickly and securely. Therefore, selecting the correct Architecture of DBMS helps in easy and efficient data management.

Ø  We choose database architecture depending on several factors like the size of the database, number of users, and relationships between the users.

Ø  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 via networks.

Ø  DBMS architecture depends upon how users are connected to the database to get their request done.

Ø  There are three types of DBMS architecture:

o   1-Tier architecture

o   2-Tier architecture

o   3-Tier architecture

Fig: Types of DBMS Architecture

A] 1-Tier Architecture:

Ø  In this type of architecture, the database is readily available on the client machine, any request made by client doesn’t require a network connection to perform the action on the database.

Ø  This type of system is generally referred as local database system.

Ø  It is the simplest architecture of Database in which the client, server, and Database all reside on the same machine.

Ø  In this architecture, the database is directly available to the user. It means the user can directly sit on the DBMS and uses it.

Ø  For example, let’s say you want to fetch the records of employee from the database and the database is available on your computer system, so the request to fetch employee details will be done by your computer and the records will be fetched from the database by your computer as well.

Ø  Any changes done here will directly be done on the database itself. It doesn't provide a handy tool for end users.

Ø  It is used for development of the local application, where programmers can directly communicate with the database for the quick response.

B] 2-Tier Architecture:

Ø  The 2-Tier architecture is same as basic client-server architecture.

Ø  Whenever client machine makes a request to access the database present at server using a query language like SQL, the server perform the request on the database and returns the result back to the client.

Ø  The APIs such as JDBC, ODBC are used for the interaction between server and client.

Ø  The user interfaces and application programs are run on the client-side.

Ø  The server side is responsible to provide the functionalities like: query processing and transaction management.

Ø  To communicate with the DBMS, client-side application establishes a connection with the server side.

Ø  Client machine and Server machine are connected with each other through a reliable network 

C] 3-Tier Architecture:

Ø  The 3-Tier architecture contains another layer between the client and server.

Ø  In this architecture, client can't directly communicate with the server.

Ø  3-Tier database Architecture design is an extension of the 2-tier client-server architecture.

Ø  A 3-tier architecture has the following layers:

o   Presentation layer (your PC, Tablet, Mobile, etc.)

o   Application layer (server)

o   Database Server

Ø  The application on the client-end interacts with an application server which further communicates with the database system.

Ø  This intermediate layer acts as a medium for the exchange of partially processed data between the server and the client. This type of architecture is used in the case of large web applications.

Ø  End user has no idea about the existence of the database beyond the application server. The database also has no idea about any other user beyond the application.

Ø  A 3 Tier Architecture in DBMS is the most popular client server architecture in DBMS in which the development and maintenance of functional processes, logic, data access, data storage, and user interface is done independently as separate modules. 

3-Tier Architecture