Re: How widespread is the use of triggers these days and how concerned about performance?....

Nari Kannan wrote:

> Fifteen years ago when databases were primarily used in the context of
> transaction-intensive applications, triggers were a nice feature of a
> DBMS system that did not get used because of performance concerns.

Back then we tended to use triggers when some cross-table transactional consistency was mandatory and the cost of doing the operation during the overnight maintenance cycle happened to be so significant that it was actually less expensive to do the data consistency operation in a trigger.

> Fast forward 15 years, it seems to me that 95% of database usage is for
> non-transaction intensive information (I could be wrong in this).
> Given this I see increasing usage of triggers for doing various
> necessary things that regular reporting does not do.

Now triggers, just like constraints, are seen as just one of many tools available to implement "business rules".

> Am I just dreaming or that triggers are being increasingly used?
>
> Are performance concerns not important in the above context as long as
> you
> are mindful of stuff like cascading triggers and keeping the trigger
> code short?

No, performance is no longer an issue. Much more important are:

• the user is protected from idiotic input and
• business rules are enforceable,
• updates are traceable and auditable

and these are enforced in triggers. Because, in the long run, the database is the only place where you can guarantee these rules can not be bypassed. (I grimace when customers say - "the app's screens were too slow so we used Excel/ODBC/SQLPlus to update the database directly ....<deep breath> ... can you help fix the data, the reports aren't 'balancing')

If performance becomes a concern, cracking the whip on the DBAs is always a good management tool. If firing a few DBAs and hiring consultants doesn't work, some organizations will then look to the next Y2K or SEC-xyz rule to help create a business case to get bigger, better, faster computers. Or finding the next best thing (internet, grids .....) Received on Fri Aug 01 2003 - 22:03:58 CDT