Coursework help:

Question

I am writing a comparitive essay on two-tier and three architecture in terms of database applications. I would just like to confirm a few things.

2 tier is Client - Server 2 tier is Application on client - database on server. 2 tier implements Direct communication. Bad security based on direct communication? However Good for small intranet based enviroments with users less than 50.

Does two tier generally use a java application (i.e. swing) in terms of a user interface and three tier a web browser?

3 tier is more scalable. 3 tier is more secure with the use of a middle tier. 3 tier is client - web server - database server

I hope you guys can contradict most of what I have written and expose a few areas I need to research further.

Thanks

Si

Answer 1

The tiers are not necessarily physical - they can be logical only and all installed on the same machine.

Take a WPF Windows application for example,

2-tier Windows WPF application

Application tier (Executible) - Includes presentation logic and domain logic in the same executible (EXE)

Database tier (SQL Server running on local machine, or another server)

3-tier Windows WPF application

Application tier (UI code only) - Installed as EXE

Domain logic tier (business rules and code to load/save data, etc) - installed with application code in separate DLL

Database tier (SQL Server running on local machine, or another server)