Hi,

> I've done some research already, but there seem to be
> no way to remove the `not null' constraint from a column, is there?

Not via standard DDL, no.

> I'd like to be sure about this since there are quite a few dependencies
> on this column... I'd have to temporarily clear many
> procedures and drop foreign keys constraints, if I would
> drop this column.

You can do this via some system table updates and a
DROP CONSTRAINT <system defined constraint name>

Alternatively, download yourself a trial version of
Database Workbench ( www.upscene.com ),
fire up the Table Editor and simply uncheck the
"Not Null" checkbox.

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server.
Upscene Productions
http://www.upscene.com