Does anyone know if there is a way to monitor sudden changes in planning behavior for a given query? For example, I'd like to monitor/alert on this kind of situ

Does anyone know if there is a way to monitor sudden changes in planning behavior for a given query? For example, I'd like to monitor/alert on this kind of situation: I'm executing the same query for many weeks/months, some table involved in the query is slowly growing over time, at some point the query planner responds to the growth by changing the plan.