There are quite a number of people blocked from upgrading to 2.3
because of #2189, whereby (it is thought due to
count queries are broken on mysql. This is a regression that happened
post the original 2.3 RC.
We really need to try and get this fixed for the next patch release,
but there's a bunch of different solutions being proposed and slow
progress being made on the discussion on the ticket, so I thought I'd
open it up here.
Basically, the options are:
1. Revert the patch that introduced the regression - it wasn't
properly +1d in the first place
2. Use a regex to replace the count term originating from the
association's :select, turning it back into COUNT(*)
3. Use a regex to replace the count term originating from the
association's :select, turning it into COUNT(tablename.primary_key)
I personally favor the last because I think that's what we'll want to
be using everywhere long term, but there are reasonable arguments for
the other two also.