SORT ORDER BY STOPKEY
2024-09-01 09:42:46
select * from
(
select * from
(
select a.*,rownum rn
from page a
where object_id >1000 and owner='SYS'
order by object_id desc
) where rownum<=20
) where rn>=20; 现在加个HINT SQL> select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST')); PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------
SQL_ID 9w6p4hu1q1z4n, child number 0
-------------------------------------
select * from ( select * from ( select /*+ index(a) */ a.*,rownum rn from page a where object_id >1000 and owner='SYS'
order by object_id desc ) where rownum<=20 ) where rn>=0 Plan hash value: 3486388599 ------------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | OMem | 1Mem | Used-Mem |
------------------------------------------------------------------------------------------------------------------------------------
|* 1 | VIEW | | 1 | 20 | 20 |00:00:01.28 | 739 | | | |
|* 2 | COUNT STOPKEY | | 1 | | 20 |00:00:01.28 | 739 | | | |
| 3 | VIEW | | 1 | 22595 | 20 |00:00:01.28 | 739 | | | |
|* 4 | SORT ORDER BY STOPKEY | | 1 | 22595 | 20 |00:00:01.28 | 739 | 1234K| 574K| 1096K (0)|
| 5 | COUNT | | 1 | | 22130 |00:00:01.22 | 739 | | | |
| 6 | TABLE ACCESS BY INDEX ROWID| PAGE | 1 | 22595 | 22130 |00:00:01.22 | 739 | | | |
|* 7 | INDEX RANGE SCAN | IDX_PAGE_3 | 1 | 22595 | 22130 |00:00:01.20 | 150 | | | |
------------------------------------------------------------------------------------------------------------------------------------ Predicate Information (identified by operation id):
--------------------------------------------------- 1 - filter("RN">=0)
2 - filter(ROWNUM<=20)
4 - filter(ROWNUM<=20)
7 - access("OBJECT_ID">1000 AND "OWNER"='SYS' AND "OBJECT_ID" IS NOT NULL)
filter("OWNER"='SYS') |* 4 | SORT ORDER BY STOPKEY | | 1 | 22595 | 20 | SORT ORDER BY STOPKEY 是指: 排序过后取数据 走索引后返回 100w条 是不是要对100w排序
最新文章
- SQLServer如何添加try catch
- linux 下链接无线网络
- 学习ASP.NET MVC(二)——我的第一个ASP.NET MVC 控制器
- DataView
- Eclipse安装easyShell插件
- iOS-OC内存管理
- [转载] google mock cookbook
- spring源码深度解析-1核心实现
- checkbox 点击全选
- 山东省第一届ACM省赛
- 理解public,protected 以及 private
- 【oracle】初学jobs
- OC - 25.CAKeyframeAnimation
- hdu 2795 线段树
- Codeforces Round #312 (Div. 2)
- cocos2d-x-3.1在eclipse中的环境搭建
- ●BZOJ 3894 文理分科
- ubuntu日志文件管理
- TP框架下载功能
- python入门(十七)python连接mysql数据库