[rt-users] 4.0.0: Upgrade database independently of installed code base?

[Alex Peters]

I am attempting to upgrade my RT instance from 3.8.7 to 4.0.0.

My elected approach is to set up the 4.0.0 instance alongside
the original 3.8.7 instance (i.e. two separate databases), and
verify that the 4.0.0 instance works properly before retiring
the 3.8.7 one.

I have successfully set up the 4.0.0 code base as a "new
installation" via "make install," set up a separate MySQL
database for 4.0.0 and copied the 3.8.7 schema into it.

I understand that I need to apply a series of sequential
upgrades to the copied database in order to make it a 4.0.0
schema and complete the 4.0.0 setup, but I can't see how this
is done.

The README document states in step 6b that "make upgrade" will
provide the command necessary to upgrade the database.  This
implies a need to overwrite an existing code base--which, in my
case, is not happening.

Given my use case--one which I hadn't imagined would be all
that uncommon--what is the correct approach to getting the
database updated to the correct schema?

(I apologise if this is explicitly covered somewhere in the
docs.  Things get harder to absorb as you read them over and
over again...)