> What? You have to understand a language to write performant code in it. That’s not a hack, that’s basic competence. The poster is not referring to understand

> What? You have to understand a language to write performant code in it. That’s not a hack, that’s basic competence. The poster is not referring to understanding the language, he/she is referring to having to guess at how to structure the query in a way that increases the chances that a good plan is within the constrained search space of plans (due to it being a combinatorial problem and the optimizer has limited time and information).