It is a bit ambiguous which list I should post this to, but this is
the closest I have seen. My apologies if it should be directed
elsewhere.

I would like to have the ability to set or remove the "NOT NULL"
requirement on a field using the alter table statement. Currently the
only way to do it is to create a temporary field, copy the data into
the temporary field, drop the old field, Recreate the old field using
the new "NOT NULL" setting, copy the temporary field into the new
field, drop the temporary field.

Not only is that a long sequence of events that works the DB server
quite hard, it also means all the Stored Procedures that use that
field need to be dropped and recreated, and this in turn forces all
the triggers using those stored procedures to be dropped.

My 2c

Adam