I'm new to OSQuery and am wondering if there's any documentation on how the tables relate to each other. In other words, which column in table A make sense to use with which other column in table B to create a join condition? For example, there are a lot of "uid" and "uuid" columns but I'm not sure they necessarily make sense to use together in joins. Some are even different data types (text vs. integer).

This would help you! https://osquery.io/schema/3.2.6

I'm familiar with that. I've even made a spreadsheet based on it in an attempt to clarify which ID columns can be matched with which others in joins, but am still uncertain in some cases.