David Johnston

Consider limiting line lengths to around 80 characters

1

I'm running 1920x1080 and have to scroll to see the end of commands and comment in GitHub. Especially for tutorial intended work that is undesirable.

Introduce SQL language "functions" first

1

I'd probably introduce SQL language "functions" first and describe them (and SQL generally) as being an imperative language. Then when introducing pl/pgsql I'd highlight that it is a procedural language...

https://www.postgresql.org/docs/9.2/static/rangetypes.html