Hi,

Few definitions regarding Single-Tier and Multi-Tier Concept in MYSQL

MYSQL Single-Tier

The Single-Tier ODBC Drivers for MYSQL are a single component installed on a data-consuming machine - depending on the architecture in which the driver is deployed, a client such as a desktop, a workstation or an application-server machine. No components need be installed on the database server.
The Open Link Single-Tier Drivers for MYSQL are a Type B class of driver developed using the MYSQL network (wire) protocol interface eliminating the need for the installation of any MYSQL-specific client networking software.

MYSQL Multi Tier

The Open Link Multi-Tier ODBC Driver for MYSQL comprises two parts. On the server you install a request broker which handles incoming connections, and a database agent which makes the connection to the database itself.
On data-consuming machines (clients or application-servers), you install a generic client. This approach presents an extra layer of abstraction, such that by installing one component on each client, you can connect to several servers, or several different databases via the same broker.
Multi-tier is ideally suited to larger installations where the network administrator wishes to handle security rules and performance configurations centrally.

The Open Link Multi-Tier Drivers for MYSQL are a Type-B class driver developed using the MYSQL network (wire) protocol interface.


For your reference i have attached the Images for Single-Tier and Multi-Tier.

Attached Images

	MYSQL Single-Tier Architecture Diagram.JPG (33.6 KB, 2 views)
	MYSQL Multi-Tier Architecture Diagram.JPG (39.7 KB, 1 views)

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-Murali..