I think this is a pretty important area to work on. Not in the direction of query hints, but rather have &quot;approved&quot; query plans, and an interface to see new query plans, and how much their costs differ.<p>That&#x27;d not only make production scenarios more reliable, but it&#x27;d also make it much easier to test tweaks to the cost model in practice.<p>The problem is that that&#x27;s a rather significant project, and it&#x27;s hard to get funding for that kind of work. The postgres companies aren&#x27;t that big, and it&#x27;s not an all that sexy feature marketing wise.