DBMS architecture (2- tier & 3-tier architecture)

DBMS Architecture

The design of a Database Management System highly depends on its architecture. It can be centralized or decentralized or hierarchical. DBMS architecture can be seen as single tier or multi tier. n-tier architecture divides the whole system into related but independent n modules, which can be independently modified, altered, changed or replaced.

In 1-tier architecture, DBMS is the only entity where user directly sits on DBMS and uses it. Any changes done here will directly be done on DBMS itself. It does not provide handy tools for end users and preferably database designer and programmers use single tier architecture.

If the architecture of DBMS is 2-tier then must have some application, which uses the DBMS. Programmers use 2-tier architecture where they access DBMS by means of application. Here application tier is entirely independent of database in term of operation, design and programming.

Most widely used architecture is 3-tier architecture. 3-tier architecture separates it tier from each other on basis of users.

In 3 tier architecture the client machine act as a front end & does not contain any direct database call. Instead the client communicate with an application server usually through interface. The application server in turn communicate with database system to fetch data.