By the way, I used a simple query on purpose to keep things simple for readers (and for me, the author!). By using such a simple SQL statement I was able to avoid complex optimizations and algorithms I would haven't been able to follow - and that wouldn't have helped readers much anyway. I wanted to get the basic idea across to people who have no prior knowledge of DB internals.
Plus I wasn't interested in comparing one DB vs. another, as much as I was interested in understanding how any DB works.
Plus I wasn't interested in comparing one DB vs. another, as much as I was interested in understanding how any DB works.