The text in the paragraph after the CQL 6 listing should be amended to: "The primary key is based on the product_id and the order_date. Let’s take a look at our query to get sample product sales for product 1 within the month of September 2021.
Again, in the CQL 3 listing, there is no boldface but the paragraph immediately following it mentions the boldface lines. It should be amended to refer to lines 3 and 4
I do see a small problem in the CQL-1 listing and in the 2nd paragraph that follows it. The listing doesn't support boldface type, but my text refers to the line in bold. Might need to change that to refer specifically to line 6 instead.
Mostly I'm concerned with the clarity of the code for the reader. Performance is a whole 'nother discipline. I'm not advocating for slow code, but most code runs fast enough as is. When you are writing code to show a reader how to do something, then code clarity is king! You may not be a pro, but your code is clear and well organized.
Nice work. If you've written the followup article, you should to add a link to it at the bottom of this one.
