Oracle常用分页语句性能比较

1nzfzk5vxn

分页一：

select b.* from
(
select a.*,rownum num from
(
select * from xg.sys_operators t
order by to_number(t.op_id)
) a
where rownum <= 5000
) b
where num > 4990


分页二：

select * from
(
select rid,num from
(
select rid,rownum num from
(
select rowid rid from xg.sys_operators t
order by to_number(t.op_id)
) a
where rownum <= 5000
) b
where num > 4990
) c,xg.sys_operators s
where c.rid = s.rowid
order by c.num


性能比较：分页一在表中数据量不是很大的时候检索效率比较高一些，分页二在表中数据量比较大的时候效率会高些。