看到有同事用execute immediate 执行SQL插入操作，不知为什么不直接用insert？

看到有同事用execute immediate 执行SQL插入操作，不知为什么不直接用insert？以下为同事的SQL:

execute immediate 'insert into freegame_down_statis ' ||'select freegame_rno.nextval, s_date, os_name, game_tyoe, user_cnt, downs ' || ' from (select '''||v_date||''' s_date,' || ' os_name,' || ' count(distinct game_id) game_tyoe,' || ' count(distinct user_id) user_cnt, ' || ' count(game_id) downs '
|| ' from gamedown_list partition('||v_p||') t1 ' || ' left join tb_d_service t2 '
|| ' on (t1.game_id = t2.servicecode and t2.servicepaytype = 0 ) ' || ' where t1.os_name in (''Android'',''BREW'',''JAVA'')' || ' group by '''||v_date||''', os_name)'; commit;