4 tier architecture and BI

hello everybody,

i am trying to understand architectures in general and somewhat baffled; your help withthe following will be highly appreciated..

in a 4 tier architecture Database -> Application -> Presentation -> Client Tier .. where does the BI layer fit in? i just want to add BI piece to something like below but I am not sure how to proceed.

Between the users and the database.  The architecture you show seems to imply somebody is coding Java.  That is not the usual case with DW implementations.  The BI layer typically covers presentation and some business logic. Business logic may also be handled during load (ETL) as well as in database.

thank you sir,

yes this is an OLTP architecture where we have an application from where users enter transactions etc. does it make sens to put the DW database after the database tier and then a BI presentation layer?

Your n-tier architecture applies on a system-by-system basis, so your OLTP architecture is different from your OLAP/BI architecture. You don't need to mix the two as they are separate systems

Regards,

Yeah, what Nick said.

As far as the Data Warehouse goes, the operational systems are a black box. All the DW is concerned with is the data feeds, which are handled by the ETL layer. ETL loads data into the DW database layer. The DW is then queried by the BI layer.