Where is 'author_id' hiding in the actual database?

I need to query the db for counts of entries (and other types of counts) based on who authored them. I can’t use channel:entries for this because of the diversity of information I’m pulling.

I need to know where the ‘author_id’ field is hiding. I’ve looked in exp_channel_data and surprisingly, there is no reference to the author of the entry. It has to be hiding somewhere, right?

I’ve got a join which equates my custom field in the channel to the member id - I just need to now restrict my results to entries that were AUTHORED by that member id…

I’m sure I’ve passed by it in the tables 100 times, but it still eludes me. Any light would be useful. Thanks!