What's annoying are fire-and-forget monster queries, where the user disconnects their laptop and goes home for the day, leaving the orphan process running overnight with no one on the other...

The cloud is just somebody else's data center. The tools are essentially the same as what you've always been using on-premises.

If the Marks column is intended to be numerically additive, for example summed or averaged for a cumulative score, then you don't want special codes representing absent or other otherwise....

From what you've already described, this sounds like a direct SQL select. 

However, if this were a stored procedure call, then you would have more options for mitigating this...

Debates over primary keys and clustered indexes never get old.

Code compilation isn't much of an issue in my realm. However, if a user runs a query that joins two or more billion row tables using a non-indexed expression and...

... This is attributed to the user clicking the operation, waiting a bit for a response, and when one was not presented, clicking the button again. I know what...