Kendra Little has a list of three things a junior DBA should know:
Confession: I was a Junior DBA for a long time before I had a clue about this. It’s not unusual– many DBAs pick up existing databases and it’s natural to accept that the settings are correct.
Except, usually they aren’t. Usually, the last person who set them up just kinda guessed.
Guess what? You’re responsible for whatever they guessed.
Kendra’s three items are definitely junior-level, but we all start somewhere.