Database architecture essentially describes the location of all the pieces of information that make up the database application. There are three different types of database architectures. They are
Two Tire Architecture
The two-tier architecture is a client–server architecture in which the client contains the presentation code and the SQL statements for data access. The database server processes the SQL statements and sends query results back to the client.
The client, or first tier, is primarily responsible for the presentation of data to the user. The different tasks and services offered by this tire are
a) Presentation services: These services provides data to the user in understanding form and it also tells how the user will interact with data.
b) Business Services / Objectives: These are types of application services which include an organization business process and requirements. These rules are prepared from day to day business in an organization.
c) Application Services: Application services provides other functions necessary for the application.
d) Data Services: Data services provide access to data independently of their location.
Three Tire Architecture
A “Multitier,” often referred to as “three-tier” or “N-tier,” architecture provides greater application scalability, lower maintenance, and increased reuse of components.
Three-tier architecture offers a technology neutral method of building client/server applications with vendors who employ standard interfaces which provide services for each logical “tier.”
From this figure, it is clear that in order to improve the performance a second-tier is included between the client and the server.
Through standard tiered interfaces, services are made available to the application. A single application many different services which may reside dissimilar platforms with different tools.
The three-tire architecture development environment is more difficult to use than the visually oriented development of two-tire system.
Multi-Tire Architecture
A multi-tier, three-tier, or N-tier implementation employs a three-tier logical architecture superimposed on a distributed physical model. Application Servers can access other application servers in order to supply services to the client application as well as supply services for other application servers.
For example, in the diagram below the client application looks to Application Server #1 to supply data from a mainframe based application. Application Server #1 has no direct access to the mainframe application but, it does know, through the development of application services, that Application Server #2 provides a service to access the data from the mainframe application which satisfies the client request. Application Server #1 then invokes the appropriate service on Application Server #2 and receives the requested data which is then passed on to the client.
Application servers can take many forms. An application server may be anything from custom application services, Transaction Processing Monitors, Database Middleware, Message Queue to a CORBA/COM based solution.
Source: springer-fundamentals-of-relational-database-management-systems-apr-2007
- Two Tire Architecture
- Three Tire Architecture
- Multi Tire Architecture
Two Tire Architecture
The two-tier architecture is a client–server architecture in which the client contains the presentation code and the SQL statements for data access. The database server processes the SQL statements and sends query results back to the client.
 |
| Two Tire Architecture |
The client, or first tier, is primarily responsible for the presentation of data to the user. The different tasks and services offered by this tire are
a) Presentation services: These services provides data to the user in understanding form and it also tells how the user will interact with data.
b) Business Services / Objectives: These are types of application services which include an organization business process and requirements. These rules are prepared from day to day business in an organization.
c) Application Services: Application services provides other functions necessary for the application.
d) Data Services: Data services provide access to data independently of their location.
Three Tire Architecture
A “Multitier,” often referred to as “three-tier” or “N-tier,” architecture provides greater application scalability, lower maintenance, and increased reuse of components.
Three-tier architecture offers a technology neutral method of building client/server applications with vendors who employ standard interfaces which provide services for each logical “tier.”
 |
| Three Tire Architecture |
Through standard tiered interfaces, services are made available to the application. A single application many different services which may reside dissimilar platforms with different tools.
The three-tire architecture development environment is more difficult to use than the visually oriented development of two-tire system.
Multi-Tire Architecture
A multi-tier, three-tier, or N-tier implementation employs a three-tier logical architecture superimposed on a distributed physical model. Application Servers can access other application servers in order to supply services to the client application as well as supply services for other application servers.
For example, in the diagram below the client application looks to Application Server #1 to supply data from a mainframe based application. Application Server #1 has no direct access to the mainframe application but, it does know, through the development of application services, that Application Server #2 provides a service to access the data from the mainframe application which satisfies the client request. Application Server #1 then invokes the appropriate service on Application Server #2 and receives the requested data which is then passed on to the client.
Application servers can take many forms. An application server may be anything from custom application services, Transaction Processing Monitors, Database Middleware, Message Queue to a CORBA/COM based solution.
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