Custom avatar question / mysql question

[islandcommuter]

I'm importing about 40,000 users from another board where they had avatars into 3.7.1. I've got the files in the right folder, but I can't figure out where the name and existence of the avatars are stored in mysql.

I've got a few avatars from new registrations, yet the avatar table is empty... and the avatarid field in the user table is empty.

What am I missing?

Thanks for your help.