We take a deeper dive with Nathan Long into IOLists in Elixir. We cover what they are, how they work, the power they have when concatenating strings, and how they are used in Phoenix and Logger. We even talk about improper lists and why they exist. And no, it isn’t a bug. We then talk about PostgreSQL features like materialized views, triggers, and using denormalized tables for solving complicated caching situations. Nathan shares some tips for when to use them and provides some cautions worth hearing.