Stage 5 can give you a huge boost in writing complex queries!

You say that like it's a good thing. I like my queries simple.

Also - the stuff you have under "stage 6" should all be learned before "stage 2" in my opinion. Knowing how to write efficient queries is far more important than group by / join / etc.

I feel like the word "partitions" used in this article should be "window functions"

I imagine it depends on use case. Anything more advanced that subqueries/CTEs is largely the domain of ETL developers (not exclusively, obviously) but most others using SQL don't need anything that advanced.

CTEs enhance readability, documentation, and testing imo. I'm very pro CTE whenever a subquery isn't the obvious choice.

It's always bothered me when I write subqueries that have to be run on each row. Good to know that there's a better way.

Very useful. I'll definitely going to use the ranking stuff.

CTEs are amazing. I discovered them semi recently and it's such a great tool to have in your belt.

Partitioning is definitely something I need to work on.

I have to create a fucking account just to fucking read your article?! Kthxbye!