delete from docu_t where doc_objtype='OPERATOR';
delete from op_constr_t;
delete from op_cond_t;
delete from op_assert_t;
delete from op_params_t;
delete from op_group_t;

alter table step_t drop constraint stopid_fk;
alter table parameter_t drop constraint paropid_fk;

delete from operator_t;
\i Operators.sql

alter table step_t add 
  constraint stopid_fk
    foreign key (st_opid)
      references operator_t (op_id);

alter table parameter_t add
  constraint paropid_fk
    foreign key (par_opid)
      references operator_t (op_id);
