Log level to debug in production?

I wanted to check how the sql queries looked like in production mode.
Launched the app in prod mode with script/server after I set
config.log_level = :debug in connfig/environments/production.rb.

For some reason, the production.log did not include any queries, just
information about the requests. Does that mean that rails magically
caches everything in my database upon initialization (right…), or am
I missing something?