row_number() over 优化

select *  from (select temp.*, row_number() over() as page_control_row_number
          from (SELECT * from table1


                   where .....      

               ) temp) temp1
where page_control_row_number >= 1  fetch first 20 rows only optimize for 20 rows


如果有order by col1,  col1必须建索引.