To add to this, even in non-discussion classes, what helps a lot is structuring things like: - what is our problem (queries are slow) - why do we have this pro

To add to this, even in non-discussion classes, what helps a lot is structuring things like: - what is our problem (queries are slow) - why do we have this problem (scanning the whole table takes a lot of I/O which is expensive) - how can we solve this problem (indexes help know where content is so you can do less I/O) - demo of it - when does this not work (when your indexes aren't selective, sometimes they can be slower than just a scan, or when it's hurting insertion speed) etc etc. Even if you mentioned what we were trying to do once in the beginning of the class (or worse, beginning of the semester), it helps a lot to go back and keep referring to it every time you introduce some new thing just so we know how this new little tidbit helps with the original issue.