存储过程动态执行SQL

CREATE OR REPLACE PROCEDURE "KM"."UPDATE_INST_META_PRO"
    is
     cursor cur is select * from recovery_inst_currmeta where flag = 0 and rownum < 1000;
     str varchar2(1024);
begin
        dbms_output.put_line('Begin...');
        for item in cur loop
          begin
             str:='' || item.update_sql || '';
             dbms_output.put_line('finished: ' || str);
             EXECUTE IMMEDIATE str;
             update recovery_inst_currmeta set flag = 1 where update_sql = item.update_sql;
             commit;
          end;
        end loop;
        dbms_output.put_line('End!');
  end;
/