drop table b;
/
drop table a;
/
create table a(pk int primary key, f1 int)
/
create table b(pk int primary key, a_f1 int, b_f1 varchar2( 1000 ))
/
ALTER TABLE b ADD CONSTRAINT fk FOREIGN KEY (a_f1) REFERENCES a(pk)
/
create index ind_b on b(a_f1)
/

declare x int; 
begin
    x := dbms_utility.get_time;
    for i in  1  ..  10  loop
     insert into a(pk, f1) values(i, i);
     for j in  1  ..  10000  loop
       insert into b(pk, a_f1, b_f1) values(i* 100000  + j, i, 'xxxxxxxxxxxxxxxx');         
     end loop;     
    end loop;    
    dbms_output.put_line('Вставляли : ' || (dbms_utility.get_time - x));
    commit;
    
    x := dbms_utility.get_time;
    for i in  1  ..  10  loop
     
     for j in  1  ..  10000  loop
      delete from b where pk = i* 100000  + j;
     end loop;       
     
     delete from a where pk = i;
    end loop;
    dbms_output.put_line(Построчно : ' || (dbms_utility.get_time - x));    
    commit;
    
    for i in 1 .. 10 loop
     insert into a(pk, f1) values(i, i);
     for j in 1 .. 10000 loop
          insert into b(pk, a_f1, b_f1) values(i*100000 + j, i, 'xxxxxxxxxxxxxxxx');         
     end loop;     
    end loop;    
    commit;
    
    x := dbms_utility.get_time;    
    for i in 1 .. 10 loop
     delete from b where a_f1 = i;  
     delete from a where pk = i;
    end loop;
    dbms_output.put_line(Зараз : ' || (dbms_utility.get_time - x));    
end;