Enable compareType by default

[CaselIT]

Change the compareType default from False to True

[sqla-tester]

Federico Caselli has proposed a fix for this issue in the main branch:

Enable compare type by default https://gerrit.sqlalchemy.org/c/sqlalchemy/alembic/+/4822

[zzzeek]

what's the background on this? I know the general idea is that at some point we redid type comparison to be a lot better. but are people looking for this? Why open ourselves up to a bunch of new issues that might be very difficult to solve?

[CaselIT]

iirc we talked a bit about this on an dev meeting.

shall we introduce a "warn" flag that's the new default, that's basically like true but only log that there are type changes, without then writing them to the migration?

[zzzeek]

nah, let's make the change. we already broke the type comparison hook silently. let's just document all this pretty prominently

[CaselIT]

ok, I'll expand the documentation a bit.