本帖最后由 yujian0902 于 2014-5-27 16:33 编辑

有次帮同事优化SQL，发现写的SQL使用in这种过滤方式，查询出来花了将近6分钟；而后我改成连接方式(join)，不到一秒钟。为什么反差如此之大？！

原SQL:

SELECT *

FROM (SELECT ROWNUM RN, A.*

FROM (SELECT LV2.DSTC_ID AreaId,

(select b.name from area_info_center@srcdb b where b.regoinid = lv2.dstc_id and rownum = 1) AreaName,

LV2.TIME_ID Time,

LV2.SAMPLE_ALL,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.RSCP_ALL / LV2.SAMPLE_ALL),2) RSCP_AVG,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.GOODCOVER1 / LV2.SAMPLE_ALL),4) KEY1,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.GOODCOVER2 / LV2.SAMPLE_ALL),4) KEY2,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.GOODCOVER3 / LV2.SAMPLE_ALL),4) KEY3,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.GOODCOVER4 / LV2.SAMPLE_ALL),4) KEY4,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.GOODCOVER5 / LV2.SAMPLE_ALL),4) KEY5,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY1 / LV2.SAMPLE_ALL),4) KEY6,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY2 / LV2.SAMPLE_ALL),4) KEY7,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY3 / LV2.SAMPLE_ALL),4) KEY8,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY4 / LV2.SAMPLE_ALL),4) KEY9,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY5 / LV2.SAMPLE_ALL),4) KEY10,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY6 / LV2.SAMPLE_ALL),4) KEY11,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY7 / LV2.SAMPLE_ALL),4) KEY12,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY8 / LV2.SAMPLE_ALL),4) KEY13,

ROUND(DECODE(LV2.SAMPLE_ALL,0,0,LV2.LV1KEY9 / LV2.SAMPLE_ALL),4) KEY14

FROM (SELECT T.DSTC_ID,

T.TIME_ID,

SUM(CASE WHEN (T.ZONE_ID = 0 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) SAMPLE_ALL,

SUM(CASE WHEN (T.ZONE_ID = 0 AND T.IDT_ID = 10000039) THEN T.IDT_VAL ELSE 0 END) RSCP_ALL,

SUM(CASE WHEN (T.ZONE_ID = 1 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER1,

SUM(CASE WHEN (T.ZONE_ID = 2 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER2,

SUM(CASE WHEN (T.ZONE_ID = 3 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER3,

SUM(CASE WHEN (T.ZONE_ID = 4 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER4,

SUM(CASE WHEN (T.ZONE_ID = 5 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER5,

SUM(CASE WHEN (T.ZONE_ID = 1 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY1,

SUM(CASE WHEN (T.ZONE_ID = 2 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY2,

SUM(CASE WHEN (T.ZONE_ID = 3 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY3,

SUM(CASE WHEN (T.ZONE_ID = 4 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY4,

SUM(CASE WHEN (T.ZONE_ID = 5 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY5,

SUM(CASE WHEN (T.ZONE_ID = 6 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY6,

SUM(CASE WHEN (T.ZONE_ID = 7 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY7,

SUM(CASE WHEN (T.ZONE_ID = 8 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY8,

SUM(CASE WHEN (T.ZONE_ID = 9 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY9

FROM CTUNI_SYS.G_HOUR_DSTC_NET_VSN_ZONE T

WHERE 1 = 1

and t.time_type = 3

and t.time_id >= '2014-04'

and t.time_id <= '2014-05'

and t.hour_id = '0'

and (t.DSTC_ID = 1919 or

t.DSTC_ID in

(select b.regoinid

from area_info_center@srcdb b

where b.parentregoinid = 1919))

and t.vsn = '0'

and t.net_type = 5

GROUP BY T.DSTC_ID, T.TIME_ID) LV2

order by lv2.dstc_id asc, lv2.time_id desc) A

WHERE ROWNUM <= 10)

WHERE RN >= 1

WO8.jpg (39.88 KB, 下载次数: 11)

原SQL执行计划

2014-5-27 16:24 上传

优化SQL:

SELECT *

FROM (SELECT ROWNUM RN,A.*

FROM (SELECT  LV2.DSTC_ID AreaId,

(select b.name from area_info_center@srcdb b where b.regoinid=lv2.dstc_id and rownum=1) AreaName,LV2.TIME_ID Time,

LV2.SAMPLE_ALL,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.RSCP_ALL / LV2.SAMPLE_ALL), 2) RSCP_AVG,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.GOODCOVER1 / LV2.SAMPLE_ALL), 4) KEY1,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.GOODCOVER2 / LV2.SAMPLE_ALL), 4) KEY2,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.GOODCOVER3 / LV2.SAMPLE_ALL), 4) KEY3,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.GOODCOVER4 / LV2.SAMPLE_ALL), 4) KEY4,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.GOODCOVER5 / LV2.SAMPLE_ALL), 4) KEY5,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY1 / LV2.SAMPLE_ALL), 4) KEY6,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY2 / LV2.SAMPLE_ALL), 4) KEY7,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY3 / LV2.SAMPLE_ALL), 4) KEY8,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY4 / LV2.SAMPLE_ALL), 4) KEY9,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY5 / LV2.SAMPLE_ALL), 4) KEY10,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY6 / LV2.SAMPLE_ALL), 4) KEY11,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY7 / LV2.SAMPLE_ALL), 4) KEY12,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY8 / LV2.SAMPLE_ALL), 4) KEY13,

ROUND(DECODE(LV2.SAMPLE_ALL, 0, 0, LV2.LV1KEY9 / LV2.SAMPLE_ALL), 4) KEY14

FROM (SELECT T.DSTC_ID,T.TIME_ID,

SUM(CASE WHEN (T.ZONE_ID = 0 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) SAMPLE_ALL,

SUM(CASE WHEN (T.ZONE_ID = 0 AND T.IDT_ID = 10000039) THEN T.IDT_VAL ELSE 0 END) RSCP_ALL,

SUM(CASE WHEN (T.ZONE_ID = 1 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER1,

SUM(CASE WHEN (T.ZONE_ID = 2 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER2,

SUM(CASE WHEN (T.ZONE_ID = 3 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER3,

SUM(CASE WHEN (T.ZONE_ID = 4 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER4,

SUM(CASE WHEN (T.ZONE_ID = 5 AND T.IDT_ID = 10000040) THEN T.IDT_VAL ELSE 0 END) GOODCOVER5,

SUM(CASE WHEN (T.ZONE_ID = 1 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY1,

SUM(CASE WHEN (T.ZONE_ID = 2 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY2,

SUM(CASE WHEN (T.ZONE_ID = 3 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY3,

SUM(CASE WHEN (T.ZONE_ID = 4 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY4,

SUM(CASE WHEN (T.ZONE_ID = 5 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY5,

SUM(CASE WHEN (T.ZONE_ID = 6 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY6,

SUM(CASE WHEN (T.ZONE_ID = 7 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY7,

SUM(CASE WHEN (T.ZONE_ID = 8 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY8,

SUM(CASE WHEN (T.ZONE_ID = 9 AND T.IDT_ID = 10000047) THEN T.IDT_VAL ELSE 0 END) LV1KEY9

FROM CTUNI_SYS.G_HOUR_DSTC_NET_VSN_ZONE T,

(select 1918 regoinid from dual

union

select b.regoinid from area_info_center@srcdb b where  b.parentregoinid=1918) S

WHERE 1 = 1

and t.time_type=3 and t.time_id>='2014-04' and t.time_id<='2014-05' and t.hour_id = '0'

and t.DSTC_ID = s.regoinid

and t.vsn='0' and t.net_type=5

GROUP BY T.DSTC_ID,T.TIME_ID) LV2

order by lv2.dstc_id asc,lv2.time_id desc) A

WHERE ROWNUM<=10) WHERE RN>=1

AL7.jpg (49.07 KB, 下载次数: 8)

2014-5-27 16:29 上传

oracle where in优化,【求助】为什么在where过滤条件中使用in这样子查询后速度变的非常慢？！...相关推荐

  1. oracle中where条件后用in这样子查询后变慢

    今日开发一个需求,其中由于需求变态,写了一个挺复杂的sql,在本地测试环境看不出问题,但到了生产就变得非常慢(由于表数据量比较大),把sql粘贴出来执行了一下大概要42秒. 我写的sql大概是这个样子 ...

  2. c语言中被调用函数只需在主调函数中声明,其他函数中不用声明,求助，函数在其他函数中使用时要先声明后调用，这个没声明就用了...

    该楼层疑似违规已被系统折叠 隐藏此楼查看此楼 如题,程序如下: #include #include //malloc,calloc,free,realloc头文件 #define LEN sizeof ...

  3. c语言定义函数后引用,求助，函数在其他函数中使用时要先声明后调用，这个没声明就用了...

    该楼层疑似违规已被系统折叠 隐藏此楼查看此楼 如题,程序如下: #include #include //malloc,calloc,free,realloc头文件 #define LEN sizeof ...

  4. ORACLE+SQL性能优化

      1. 访问Table的方式 ORACLE 采用两种访问表中记录的方式: a. 全表扫描 全表扫描就是顺序地访问表中每条记录. ORACLE采用一次读入多个数据块(database block)的方 ...

  5. oracle中or会使索引,为何查询条件中多了　OR 选项，索引就走全扫描？

    ORACLE 11204, SOLARIS 如下:原始写法,where 条件中,有 OR 条件,这时,索引 IDX_BD_LOTMASTER_NO 走全索引扫描,导致效率非常低, -bash-3.2$ ...

  6. java criteria限制条数_java架构—Oracle SQL性能优化

    (1) 选择最有效率的表名顺序(只在基于规则的优化器中有效): ORACLE的解析器按照从右到左的顺序处理FROM子句中的表名,FROM子句中写在最后的表(基础表 driving table)将被最先 ...

  7. Oracle数据库管理----性能优化

    https://blog.csdn.net/yzllz001/article/details/54848513 数据库访问优化法则 要正确的优化SQL,我们需要快速定位能性的瓶颈点,也就是说快速找到我 ...

  8. oracle SQL性能优化

    我们要做到不但会写SQL,还要做到写出性能优良的SQL,以下为笔者学习.摘录.并汇总部分资料与大家分享! (1)      选择最有效率的表名顺序(只在基于规则的优化器中有效): ORACLE的解析器 ...

  9. 高级SQL优化(二) ——《12年资深DBA教你Oracle开发与优化——性能优化部分》

    目录: Oracle数据完整性和锁机制  索引及优化之表分析  表分析.约束及表间关系  Oracle体系结构1 Oracle体系结构2  海量数据库及分区1  海量数据库及分区2  海量数据库及分区 ...

最新文章

  1. 【spring boot】【spring cloud】异常：找不到方法HikariDataSource.getMetricsTrackerFactory()
  2. mysql存储过程——procedure[prəˈsiːdʒər]
  3. 0003-Longest Substring Without Repeating Characters(无重复字符的最长子串)
  4. html overflow 样式,css样式之overflow-x属性样式
  5. python神经网络实例_Python编程实现的简单神经网络算法示例
  6. 实用常识 | 一篇文章记录如何轻松清理C盘，C盘又满了，继续盘它
  7. WenLan-10亿参数！别只玩GPT，来看看人大中科院联手打造第一个大规模多模态中文预训练模型BriVL...
  8. 数据结构基础--线性表
  9. git如何将远程仓库代码，覆盖本地代码
  10. Handler机制原理图、源码、使用！！！！！
  11. 最简单的非线性动力系统
  12. Github上关于iOS的各种开源项目集合
  13. 苹果手机如何分享wifi密码_WiFi密码破解器 v5.1.3手机版
  14. 学弟学妹们，如果你想吃透 Java字节码的话，看这篇就好了！（超级硬核，建议收藏）
  15. beyong compare激活
  16. Android中如何实现多个框,android几种不同对话框的实现方式
  17. 【脑洞大开】神经网络vs非公理化推理系统(NARS)
  18. Debian搭建Samba服务
  19. 运行项目遇到：该网页无法正常运作,localhost将您重定向的次数过多时的解决方案
  20. QT实现ping功能

热门文章

  1. c++ linux下读取指定目录的所有文件名字
  2. 大剑无锋之Hbase的优化【面试推荐】
  3. Spark _13_topN
  4. Spark _13_二次排序问题
  5. 无法打开虚拟机，获取该虚拟机的所有权失败。 主机上的某个应用程序正在使用该虚拟机。
  6. javaSE各阶段练习题--流程控制
  7. JAVA程序设计----集合基础之Map
  8. 牛客网_PAT乙级1014_科学计数法 (20)
  9. java中wait和sleep的区别
  10. Spring Boot Starters介绍