Notably you can have your cake and eat it too if you want by naming the database column via the is_ pattern and the Ecto schema via ? by using the source option.

In that case I still don’t like any of the poll options, lol. No, it’s not an idiom and no, it’s not an anti-pattern. There is certainly no harm in it beyond personal preference. I personally really like the extra clarity and avoiding is_, has_ etc. And I don’t have an example off the top off my head but there are times where it’s awkward to come up with the correct English prefix or the correct one reads strangely. If I think of one I’ll post back.

Absolutely not, DB booleans will always be is_this_or_that on my watch. I have zero desire fighting with edge cases. Sticking to good old alpha-numeric strings for these things.

I do also name my database columns with a trailing ?, it does mean needing to quote the field when writing SQL by hand (like in psql).

Trailing ? is certainly not just a pattern for functions. E.g. ecto uses changeset.valid?.