> > All the constraints prevents this modification, or just some types of
> > them (primary key, foreign keys, check, references in triggers and SP,
> > ...) ? I want to know if I must drop all the constraints, or if I can
> > choose some of them ?
>
> Primary and foreign key - it's a problem with the index created by the
> constraint, and only those two styles of constraint create indexes.

Unique constraints as well.

Martijn Tonies
Database Workbench - development tool for Firebird and more!
Upscene Productions
http://www.upscene.com
My thoughts:
http://blog.upscene.com/martijn/
Database development questions? Check the forum!
http://www.databasedevelopmentforum.com