https://www.postgresql.org/docs/current/runtime-config-query.html
https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-JOIN-COLLAPSE-LIMIT

2023
floy: Introduction to Postgres Query Planning 0:00 of 57:02
    https://www.youtube.com/watch?v=k9AAkbII3Pg
    https://leftshift.github.io/query-planner-talk/