DBMS

The 3-Tier architecture contains another layer between the client and server. In this architecture, client can't directly communicate with the server. The application on the client-end interacts with an application server which further communicates with the database system. 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. The 3-Tier architecture is used in case of large web application. Fig: 3-tier Architecture

The 2-Tier architecture is same as basic client-server. In the two-tier architecture, applications on the client end can directly communicate with the database at the server side. For this interaction, API's like:  ODBC ,  JDBC  are used. The user interfaces and application programs are run on the client-side. The server side is responsible to provide the functionalities like: query processing and transaction management. To communicate with the DBMS, client-side application establishes a connection with the server side. Fig: 2-tier Architecture

In this architecture, the database is directly available to the user. It means the user can directly sit on the DBMS and uses it. Any changes done here will directly be done on the database itself. It doesn't provide a handy tool for end users. The 1-Tier architecture is used for development of the local application, where programmers can directly communicate with the database for the quick response.

Types of DBMS Architecture   Database architecture can be seen as a single tier or multi-tier. But logically, database architecture is of two types like:  2-tier architecture  and  3-tier architecture .

The DBMS design depends upon its architecture. 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. The client/server architecture consists of many PCs and a workstation which are connected via the network. DBMS architecture depends upon how users are connected to the database to get their request done.

There are following differences between DBMS and File system: DBMS File System DBMS is a collection of data. In DBMS, the user is not required to write the procedures. File system is a collection of data. In this system, the user has to write the procedures for managing the database. DBMS gives an abstract view of data that hides the details. File system provides the detail of the data representation and storage of data. DBMS provides a crash recovery mechanism, i.e., DBMS protects the user from the system failure. File system doesn't have a crash mechanism, i.e., if the system crashes while entering some data, then the content of the file will lost. DBMS provides a good protection mechanism. It is very difficult to protect a file under the file system. DBMS contains a wide variety of sophisticated techniques to store and retrieve the data. File system can't efficiently store and retrieve the data. DBMS takes care of Concurrent access of data using some form of lockin