Ask HN: What would you consider to be essential reading for database design?

Aside from a foundational understanding of database operations I really lack the proper knowledge to make proper design descisions for my databases and aplications that interact with those databases. There arent many people at my company that are particularly wise when it comes to this topic and it feels like we are really missing out on some really simple improvements just because we are oblivious to them.

Are there any recommedations for essential reading or proper practice guides for improving database skills? I'm reading 'Database Internals' by Alex Petrov and its really interesting so far but not so practically applicable for me at the moment. It would be great to hear any resources that made a real impact on how you went about working with databases.

I'm mainly interested in SQL databases but resources on no-SQL would be welcome too.