> Is possible modify the table RDB$USER_PRIVILEGES directy.
>
> I like agregate the privileges from roles to user, example, is possible
> this (is a dirty e imcomplete sentence of example):
>
> Variables:
> user: User to grant the privileges
> role: Role from suply the privileges
>
> insert into RDB$USER_PRIVILEGES (RDB$USER, RDB$GRANTOR, RDB$PRIVILEGE,
> RDB$GRANT_OPTION, RDB$RELATION_NAME, RDB$FIELD_NAME, RDB$USER_TYPE,
> RDB$OBJECT_TYPE)
> select :user, RDB$GRANTOR, RDB$PRIVILEGE, NULL, RDB$RELATION_NAME,
> RDB$FIELD_NAME, 8, 0
> from RDB$USER_PRIVILEGES
> where (RDB$USER_PRIVILEGES = :role)
>

looks interesting - why don't you try it on a copy of the database?
Alan