Add note for Impact Check for query changes

doc/development/service_ping/review_guidelines.md

@@ -57,6 +57,7 @@ are regular backend changes.
   generating the metric's YAML definition.
 - Add the `~database` label and ask for a [database review](../database_review.md) for
   metrics that are based on Database.
+- Add `~Data Warehouse::Impact Check` for any database metric that has a query change.
 - For tracking using Redis HLL (HyperLogLog):
   - Check the Redis slot.
   - Check if a [feature flag is needed](implement.md#recommendations).