upsertWhere in Database.Persist.Postgresql has too strict a type signature

[Vlix]

The constraints for upsertWhere are as follows:

( backend ~ PersistEntityBackend record
, PersistEntity record
, PersistEntityBackend record ~ SqlBackend
, MonadIO m
, PersistStore backend
, BackendCompatible SqlBackend backend
, OnlyOneUniqueKey record
) =>

But as you might notice, it's saying BackendCompatible SqlBackend backend AND backend ~ SqlBackend (via a small detour using PersistEntityBackend record).
So it's basically just saying the backend HAS to be SqlBackend. I believe this should be able to be loosened (so we can use our own backend)

At first glance, I think the backend ~ PersistEntityBackend record is the only unnecessary constraint. 🤔

[Vlix]

This of course also applies to upsertManyWhere