connet by用法一则

可根据表的多少,来写exp语句
select max(sys_connect_by_path(table_name, ',')) tablelist
  from (select table_name,
               ceil(sum(num_rows) over(order by table_name asc) / 20000000) s1,
               rank() over(order by table_name asc) rk
          from user_tables)
connect by rk = prior rk - 1
       and s1 = prior s1
group by s1