From the article: > Have a good mental model of what the optimizer can and cannot do. Most DB query planner designers and implementers have little imagination

From the article: > Have a good mental model of what the optimizer can and cannot do. Most DB query planner designers and implementers have little imagination, and their mental model of what optimizers can and cannot do is, well, extremely narrow-minded. There is huge unexplored space of what query planning can be (at least for analytic queries, and we think in columnar terms) - if we just stop insisting on thinking of DBMS operations as black boxes.