• Completed Section 7. Subquery on https://www.postgresqltutorial.com/. Slightly confusing that they are similar to joins in many ways. Need to delve into this deeper some day and understand intricies of both. For now a regular join will probably suffice for most operations.
• Bad idea to starting learning Common Table Expressions and Recursive queries using CTEs whilst tired. Need to review these concepts again completely baffled by it.
• Read a few more pages of Deep Work. Interesting stories about “winners” and how they succeeeded by deep focus.