you can turn on rule debug (Tools>System>System panel>General settings and it is the last check box). Then you can see whether db rules have triggered in logserver.txt. BUT be warned this leads to VERY large log files.
There was an issue with sP11 where the check box was omitted from the screen. If this is the case for you, try adding an update data action to update a text field to say "rule fired" just for testing.
just watch out if it is a production server and you have a few hundred db rules then the performance of the server will be impacted and you should not keep it running for a very long time...basically here is a very simple example i once triggered Rule debugging and the response time for a record to open would drop from a few seconds to over 30 seconds....now how is that for impact :)
Personally i find a less stressful tactic is to simply update a field with some sort of data preferably a custom date field with the current time...or a number field increment it with one. or in some cases when i need multiple updates rules to be monitored i concatenate onto a text field...Enjoy!!
Simple way I often use is just to add a line to the rule setting some field to a test value - eg use Infromation, or set up a custom text field and add it to the form temporarily. Then in the db rule just set it to Test or current date or something like that. It's a lot easier than trying to hunt through heaps of debugging trace. Hope that helps........Ken.