12c 中的标量子查询被transform成外连接-哎呀我的天呐-ITPUB博客

  • 博客访问: 1713161
  • 博文数量: 221
  • 用 户 组: 普通用户
  • 注册时间: 2014-10-30 10:32
  • 认证徽章:
文章分类

全部博文(221)

文章存档

2018年(7)

2017年(19)

2016年(24)

2015年(125)

2014年(46)

分类: Oracle

2015-08-22 10:04:31

select (select max(object_id) from test2 b where b.object_id =a.object_id) from test1 a

变成如下:

点击(此处)折叠或打开

  1. SELECT VW_SSQ_1.MAX_OBJECT_ID
  2.   FROM (SELECT MAX(B.OBJECT_ID) "MAX_OBJECT_ID", B.OBJECT_ID "ITEM_1"
  3.           FROM TEST2 B
  4.          GROUP BY B.OBJECT_ID) "VW_SSQ_1",
  5.        TEST1 A
  6.  WHERE VW_SSQ_1.ITEM_1(+) = A.OBJECT_ID


10053中:

点击(此处)折叠或打开

  1. JE: Considering Join Elimination on query block SEL$C772B8D1 (#1)
  2. *************************
  3. Join Elimination (JE)
  4. *************************
  5. SQL:******* UNPARSED QUERY IS *******
  6. SELECT "VW_SSQ_1"."MAX(OBJECT_ID)" "(SELECTMAX(OBJECT_ID)FROMTEST2" FROM (SELECT MAX("B"."OBJECT_ID") "MAX(OBJECT_ID)","B"."OBJECT_ID" "ITEM_1" FROM "SYS"."TEST2" "B" GROUP BY "B"."OBJECT_ID") "VW_SSQ_1","SYS"."TEST1" "A" WHERE "VW_SSQ_1"."ITEM_1"(+)="A"."OBJECT_ID"
  7. SQL:******* UNPARSED QUERY IS *******
  8. SELECT "VW_SSQ_1"."MAX(OBJECT_ID)" "(SELECTMAX(OBJECT_ID)FROMTEST2" FROM (SELECT MAX("B"."OBJECT_ID") "MAX(OBJECT_ID)","B"."OBJECT_ID" "ITEM_1" FROM "SYS"."TEST2" "B" GROUP BY "B"."OBJECT_ID") "VW_SSQ_1","SYS"."TEST1" "A" WHERE "VW_SSQ_1"."ITEM_1"(+)="A"."OBJECT_ID"
  9. Query block SEL$C772B8D1 (#1) unchanged









阅读(3786) | 评论(0) | 转发(0) |
0

上一篇:redis 事务及锁应用【九】

下一篇:sql 练习

给主人留下些什么吧!~~
评论热议
请登录后评论。

登录 注册

/123/833T.html /gpw/740l.html /bbs/423T.html /0088/673k.html /bbsy/214T.html /xyw/202z.html /8888/116g.html /0088/042T.html /123/570b.html /ymw/627d.html /ks/636e.html /3088/847q.html /88410/427j.html /boss/841D.html /boss/716c.html /gpw/061u.html /55901/153P.html /wb/116b.html /daxue/205C.html /ks/741N.html /88410/728w.html /ks/860K.html /88410/053q.html /xyw/456m.html /0088/124w.html /bbsy/183p.html /ggs/600x.html /bg88/885b.html /boss/251d.html /gpw/140H.html /123/158K.html /88410/076W.html /pmw/146w.html /55901/614R.html /123/066R.html /pmw/101g.html /8888/440j.html /88410/538v.html /88410/665O.html /123/805H.html /55901/081L.html /gupiao/770u.html /boss/888I.html