how to trigger a statistics update I have a certain table in my OLTP database, which is bulk-updated by several users.
There is no way to know when they will update the table (somewhere between 5 times a day and once in a week).  

The problem is, that the update does not cause the statistics to be automatically updated,
but it is a big enough update to cause SQL Server to use a poor query plan.
(the table has ~500k rows and the operation inserts/updates between 5k and 20k rows)

My question is how should i trigger a statistics update?
My thoughts:


A job which will run every 30 minutes and check for changes using rowmodctr. The job will then update statistics if necessary
A DML trigger which will check for changes and start a job when necessary. The job will update statistics  


Of course the solution has to be server side, application changes are not welcome :)

One more thing is that I might need the same or similiar for more than just this one table so the solution has to be generic (use a modified-sp_updatestats with parameters for... everything?).
If you are running SQL Server 2008 R2 SP1 or newer you can turn on the trace flag which changes when auto update stats runs.  The traceflag is 2371 and it changes the stats update trigger from 20% + 500 rows to a sliding scale.

I talk about the finer points of the traceflag here.