TIL, 2017-07-04, SQL Queries Day

association_cache–good to test if an association has been loaded or not.
PN cer files
If you need something that is just one table away, then you might want to do the Author.joins.select('books.title as book_title').joins(:books) thing, usable especially for has_one or belongs_to associations.
Each AR query usually only runs against one table. You have to figure out when to join and when to do includes.
Running db-query-matchers to check SQL queries–this is an awesome gem.
Rendering something and then
Serializer with a serializer inside: you have to explicitly pass scopes or AR results if it turns out that the needed database objects are already existing in memory. You can do the optional arguments if you need to.
vimrc location: :version in Vim.
Good to know that I know some programming tools that I expect will still be here in the future: Vim, Unix, man pages. I think at some point I will need to learn C, probably Python.
LLVM is pretty important to learn.
Set time zone in Ruby: TZ=UTC Reference