I am a JavaScript developer and I use Postgres in my projects. My knowledge of SQL (and Postgres) is fairly light and although I do get by, I would like to build a stronger foundation.Specifically I'd like to get better at;  - SQL fundamentals
  - designing DB schemas
  - concepts like normalisation, referential integrity
  - ongoing DB maintenance tips (e.g. for data migrations)
  - any recommended general best practices

All resources or courses are welcome. Thank you!