As well as the basics, it really helps to understand all the different options for window frames, allowing you to only look backwards or forwards a certain amou

As well as the basics, it really helps to understand all the different options for window frames, allowing you to only look backwards or forwards a certain amount, or skip the current row etc with more recent support in Postgres at least. Also if you want to get really fancy, it's always worth remembering that you can write your own aggregates in Postgres, which can of course work as window functions.