Re: Business-logic in 3-tier architecture
Date: Sat, 12 Oct 2002 20:22:03 GMT
Message-ID: <3da88466.510794_at_news.wanadoo.es>
On Wed, 09 Oct 2002 23:40:24 GMT, "Arthur Yeo" <ayeo_at_acm.org> wrote:
>Theoretically, everyone knows that business logic is supposed to be in the
>middle-tier according to the 3-tier architecture. This seems to be
>counter-intuitive to Active Database concepts such as putting business logic
>in triggers with help from store procedures in the DBMS (which are all in
>the 3rd-tier of the 3-tier architecture.)
The 3 tiers are at implementation level not at logical level.
Logically there are still 2 tiers: client applications and the DBMS,
but the logical DBMS has 2 physical tiers: the middleware and the
SQL-DBMS.
With a relational DBMS triggers are not needed because you can enforce
all business logic declaratively in a much better way.
Sadly, in a lot of cases the logical DBMS is not a relational DBMS.
In the worst cases the logical DBMS is a specific purpose object
(network) DBMS that uses an SQL-DBMS behind the scenes as a physical
storage system.
Alfredo Received on Sat Oct 12 2002 - 22:22:03 CEST