Phone interview. I have a theoretical mathematics degree and was recommended by another employee, but had no SQL experience (when my friend got the job, they taught her SQL when she trained, as she had my identical academic background as we went to school together; she was hired in 2016), although I'm familiar with other programming languages. They seemed to like everything about me except my lack of SQL knowledge, and told me that's why they had chosen to look elsewhere. If you apply and get an interview, make sure you know at least SQL fundamentals because they will ask you to define and explain the difference between basic concepts like various loops, all common variables and when each are used, et cetera. Make sure you have questions for them! Good luck to all those that apply.
RIDDLE PRACTICE
Oh, and if you want more riddle practice, you should read "Are You Smart Enough to Work At Google?" It has most of the riddle questions they ask as well as other companies, and various others that are fun and good practice. If you're looking for other puzzle books for practice or general entertainment, check out Moscow Puzzles, Mensa Puzzle Books, and anything by Raymond Smullyan (these are great formal logic based puzzles, which are a nice way to refresh formal logic if you've taken a break).