> Also what’s fun is that the data in the tables can change the explain plan. 1. This change tends to be in your favour, not against you. 2. Data is important

> Also what’s fun is that the data in the tables can change the explain plan. 1. This change tends to be in your favour, not against you. 2. Data is important, not the code. Of course the plan would change if your data changes. That is the point of the query planner, to find the most efficient way of retrieving the data, based of course on the contents of the database. I agree that you need a good knowledge of your database in order to be effective. Just like with C++, for example. Unfortunately we're not at the point where we can achieve optimal results without understanding the fundamentals, regardless of the programming paradigm.