Comment by brightball

Agreed. I used triggers frequently for things like incrementing/decrementing count fields for dashboards because it's the only way to guarantee those numbers are correct while ensuring something in the application hasn't bypassed a callback or handler to modify the data.

You only need to cover three scenarios and it's very simple to implement. Recorded added +1, Record removed -1, Record moved +1 & -1.

If you have counts that are more complicated, it doesn't work but this solution easily beats semi-frequent COUNT queries.