Delete 语句带有子查询的sql优化

背景：
接到开发通知，应用页面打不开，让我协助。。。

（开发跟我说，表GV_BOOKS一直有锁，锁了有1个多小时了，问我能不能把锁释放掉，我回答他们说，这肯定是sql性能问题，表上有锁是正常现象，不是锁导致的sql执行不出来）。

利用工具，追踪到以下sql。

--sql代码
DELETE GV_BOOKS 
 WHERE ACCOUNTID IN 
                     (SELECT ACCOUNTID
                       FROM GV_BOOKS
                     MINUS
                     SELECT A.ACCOUNTID
                       FROM GV_ACCOUNTS A, VW_BP_ACCOUNT_SYN B
                      WHERE A.DBLINK = B.DB_LINK
                        AND A.ACCOUNTNO = B.ACNTNO
                     MINUS
                     SELECT A.ACCOUNTID
                       FROM GV_ACCOUNTS A, VW_CNTACNT_GVIEW B
                      WHERE A.DBLINK = B.DB_LINK
                        AND A.ACCOUNTNO = B.NO);

--执行计划
Plan hash value: 1376647110

-------------------------------------------------------------------------------------------------------
| Id  | Operation                           | Name            | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------------------------------------
|   0 | DELETE STATEMENT                    |                 |   110M|  2734M|  1129  (19)| 00:00:14 |
|   1 |  DELETE                             | GV_BOOKS        |       |       |            |          |
|*  2 |   FILTER                            |                 |       |       |            |          |
|   3 |    TABLE ACCESS FULL                | GV_BOOKS        | 86600 |  2198K|   104   (2)| 00:00:02 |
|   4 |    MINUS                            |                 |       |       |            |          |
|   5 |     MINUS                           |                 |       |       |            |          |
|   6 |      SORT UNIQUE NOSORT             |                 |  1274 |  5096 |     7  (15)| 00:00:01 |
|*  7 |       INDEX RANGE SCAN              | IX_GV_BOOKS     |  1274 |  5096 |     6   (0)| 00:00:01 |
|   8 |      SORT UNIQUE NOSORT             |                 |     1 |    39 |     5  (20)| 00:00:01 |
|   9 |       NESTED LOOPS                  |                 |     1 |    39 |     4   (0)| 00:00:01 |
|* 10 |        TABLE ACCESS BY INDEX ROWID  | GV_ACCOUNTS     |     1 |    23 |     1   (0)| 00:00:01 |
|* 11 |         INDEX UNIQUE SCAN           | PK_GV_ACCOUNTS  |     1 |       |     0   (0)| 00:00:01 |
|* 12 |        TABLE ACCESS FULL            | BP_ACCOUNT      |     1 |    16 |     3   (0)| 00:00:01 |
|  13 |     NESTED LOOPS OUTER              |                 |     1 |    96 |     2   (0)| 00:00:01 |
|  14 |      NESTED LOOPS OUTER             |                 |     1 |    83 |     2   (0)| 00:00:01 |
|  15 |       NESTED LOOPS OUTER            |                 |     1 |    70 |     2   (0)| 00:00:01 |
|  16 |        NESTED LOOPS OUTER           |                 |     1 |    57 |     2   (0)| 00:00:01 |
|  17 |         NESTED LOOPS                |                 |     1 |    44 |     2   (0)| 00:00:01 |
|* 18 |          TABLE ACCESS BY INDEX ROWID| GV_ACCOUNTS     |     1 |    23 |     1   (0)| 00:00:01 |
|* 19 |           INDEX UNIQUE SCAN         | PK_GV_ACCOUNTS  |     1 |       |     0   (0)| 00:00:01 |
|  20 |          TABLE ACCESS BY INDEX ROWID| CB_ACCOUNT      |    81 |  1701 |     1   (0)| 00:00:01 |
|* 21 |           INDEX UNIQUE SCAN         | IX_CB_ACC_NO    |     1 |       |     0   (0)| 00:00:01 |
|* 22 |         INDEX UNIQUE SCAN           | ACCOUNT_EXT_KEY |    81 |  1053 |     0   (0)| 00:00:01 |
|* 23 |        INDEX UNIQUE SCAN            | ACCOUNT_EXT_KEY |    81 |  1053 |     0   (0)| 00:00:01 |
|* 24 |       INDEX UNIQUE SCAN             | ACCOUNT_EXT_KEY |    81 |  1053 |     0   (0)| 00:00:01 |
|* 25 |      INDEX UNIQUE SCAN              | ACCOUNT_EXT_KEY |    81 |  1053 |     0   (0)| 00:00:01 |
-------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter( EXISTS ( (SELECT "ACCOUNTID" FROM "GV_BOOKS" "GV_BOOKS" WHERE 
              "ACCOUNTID"=:B1)MINUS (SELECT "A"."ACCOUNTID" FROM NSTCSA."BP_ACCOUNT" 
              "BP_ACCOUNT","GV_ACCOUNTS" "A" WHERE "A"."ACCOUNTID"=:B2 AND "A"."DBLINK"='90' AND 
              "A"."ACCOUNTNO"="ACNTNO")MINUS (SELECT "A"."ACCOUNTID" FROM NSTCSA."CB_ACCOUNT_EXT" 
              "E",NSTCSA."CB_ACCOUNT_EXT" "D",NSTCSA."CB_ACCOUNT_EXT" "C",NSTCSA."CB_ACCOUNT_EXT" 
              "B",NSTCSA."CB_ACCOUNT" "A","GV_ACCOUNTS" "A" WHERE "A"."ACCOUNTID"=:B3 AND "A"."DBLINK"='90' 
              AND "A"."ACCOUNTNO"="A"."ACCOUNT_NO" AND "B"."EXT_KEY"(+)='CALCINTR' AND 
              "A"."ACCOUNT_ID"="B"."ACCOUNT_ID"(+) AND "C"."EXT_KEY"(+)='DAYMODE' AND 
              "A"."ACCOUNT_ID"="C"."ACCOUNT_ID"(+) AND "D"."EXT_KEY"(+)='FEEMODE1' AND 
              "A"."ACCOUNT_ID"="D"."ACCOUNT_ID"(+) AND "E"."EXT_KEY"(+)='FEEMODE2' AND 
              "A"."ACCOUNT_ID"="E"."ACCOUNT_ID"(+))))
   7 - access("ACCOUNTID"=:B1)
  10 - filter("A"."DBLINK"='90')
  11 - access("A"."ACCOUNTID"=:B1)
  12 - filter("A"."ACCOUNTNO"="ACNTNO")
  18 - filter("A"."DBLINK"='90')
  19 - access("A"."ACCOUNTID"=:B1)
  21 - access("A"."ACCOUNTNO"="A"."ACCOUNT_NO")
  22 - access("A"."ACCOUNT_ID"="E"."ACCOUNT_ID"(+) AND "E"."EXT_KEY"(+)='FEEMODE2')
  23 - access("A"."ACCOUNT_ID"="D"."ACCOUNT_ID"(+) AND "D"."EXT_KEY"(+)='FEEMODE1')
  24 - access("A"."ACCOUNT_ID"="C"."ACCOUNT_ID"(+) AND "C"."EXT_KEY"(+)='DAYMODE')
  25 - access("A"."ACCOUNT_ID"="B"."ACCOUNT_ID"(+) AND "B"."EXT_KEY"(+)='CALCINTR')

分析

表信息：

GV_BOOKS ：86668行数据
子查询 ：1行数据

由以上信息可以想到，让子查询方向驱动主表GV_BOOKS

改写后代码：

执行时间 ：1s内

DELETE /*+ use_nl(tp@a,GV_BOOKS) */ GV_BOOKS 
 WHERE ACCOUNTID IN (select /*+ qb_name(a)*/ ACCOUNTID from 
                     (SELECT ACCOUNTID
                       FROM GV_BOOKS
                     MINUS
                     SELECT A.ACCOUNTID
                       FROM GV_ACCOUNTS A, VW_BP_ACCOUNT_SYN B
                      WHERE A.DBLINK = B.DB_LINK
                        AND A.ACCOUNTNO = B.ACNTNO
                     MINUS
                     SELECT A.ACCOUNTID
                       FROM GV_ACCOUNTS A, VW_CNTACNT_GVIEW B
                      WHERE A.DBLINK = B.DB_LINK
                        AND A.ACCOUNTNO = B.NO) tp);

Plan hash value: 9035204

----------------------------------------------------------------------------------------------------------
| Id  | Operation                              | Name            | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------------------------------------
|   0 | DELETE STATEMENT                       |                 |     1 |   104 |    13  (31)| 00:00:01 |
|   1 |  DELETE                                | GV_BOOKS        |       |       |            |          |
|   2 |   NESTED LOOPS                         |                 |       |       |            |          |
|   3 |    NESTED LOOPS                        |                 |     1 |   104 |    13  (31)| 00:00:01 |
|   4 |     VIEW                               |                 |     1 |    13 |    13  (31)| 00:00:01 |
|   5 |      MINUS                             |                 |       |       |            |          |
|   6 |       MINUS                            |                 |       |       |            |          |
|   7 |        SORT UNIQUE                     |                 |     1 |    13 |            |          |
|   8 |         TABLE ACCESS FULL              | GV_BOOKS        |     1 |    13 |     2   (0)| 00:00:01 |
|   9 |        SORT UNIQUE                     |                 |     1 |    66 |            |          |
|* 10 |         HASH JOIN                      |                 |     1 |    66 |     6  (17)| 00:00:01 |
|* 11 |          TABLE ACCESS FULL             | GV_ACCOUNTS     |     1 |    49 |     2   (0)| 00:00:01 |
|  12 |          TABLE ACCESS FULL             | BP_ACCOUNT      |    33 |   561 |     3   (0)| 00:00:01 |
|  13 |       SORT UNIQUE                      |                 |     1 |   117 |            |          |
|  14 |        NESTED LOOPS OUTER              |                 |     1 |   117 |     2   (0)| 00:00:01 |
|  15 |         NESTED LOOPS OUTER             |                 |     1 |   105 |     2   (0)| 00:00:01 |
|  16 |          NESTED LOOPS OUTER            |                 |     1 |    93 |     2   (0)| 00:00:01 |
|  17 |           NESTED LOOPS OUTER           |                 |     1 |    81 |     2   (0)| 00:00:01 |
|  18 |            NESTED LOOPS                |                 |     1 |    69 |     2   (0)| 00:00:01 |
|* 19 |             TABLE ACCESS FULL          | GV_ACCOUNTS     |     1 |    49 |     2   (0)| 00:00:01 |
|  20 |             TABLE ACCESS BY INDEX ROWID| CB_ACCOUNT      |     1 |    20 |     0   (0)| 00:00:01 |
|* 21 |              INDEX UNIQUE SCAN         | IX_CB_ACC_NO    |     1 |       |     0   (0)| 00:00:01 |
|* 22 |            INDEX UNIQUE SCAN           | ACCOUNT_EXT_KEY |     1 |    12 |     0   (0)| 00:00:01 |
|* 23 |           INDEX UNIQUE SCAN            | ACCOUNT_EXT_KEY |     1 |    12 |     0   (0)| 00:00:01 |
|* 24 |          INDEX UNIQUE SCAN             | ACCOUNT_EXT_KEY |     1 |    12 |     0   (0)| 00:00:01 |
|* 25 |         INDEX UNIQUE SCAN              | ACCOUNT_EXT_KEY |     1 |    12 |     0   (0)| 00:00:01 |
|* 26 |     INDEX RANGE SCAN                   | IX_GV_BOOKS     |     1 |       |     0   (0)| 00:00:01 |
|  27 |    TABLE ACCESS BY INDEX ROWID         | GV_BOOKS        |     1 |    91 |     0   (0)| 00:00:01 |
----------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

  10 - access("A"."ACCOUNTNO"="ACNTNO")
  11 - filter("A"."DBLINK"='90')
  19 - filter("A"."DBLINK"='90')
  21 - access("A"."ACCOUNTNO"="A"."ACCOUNT_NO")
  22 - access("A"."ACCOUNT_ID"="D"."ACCOUNT_ID"(+) AND "D"."EXT_KEY"(+)='FEEMODE1')
  23 - access("A"."ACCOUNT_ID"="C"."ACCOUNT_ID"(+) AND "C"."EXT_KEY"(+)='DAYMODE')
  24 - access("A"."ACCOUNT_ID"="B"."ACCOUNT_ID"(+) AND "B"."EXT_KEY"(+)='CALCINTR')
  25 - access("A"."ACCOUNT_ID"="E"."ACCOUNT_ID"(+) AND "E"."EXT_KEY"(+)='FEEMODE2')
  26 - access("ACCOUNTID"="ACCOUNTID")

优化方法二：

根据原sql执行计划，看出sql是走的filter，也就是子查询并未展开。
所以添加hint（unnest）让优化器对子查询展开。

执行时间：1s内

--执行计划
Plan hash value: 4288598425

-------------------------------------------------------------------------------------------------------------
| Id  | Operation                        | Name             | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
-------------------------------------------------------------------------------------------------------------
|   0 | DELETE STATEMENT                 |                  |   110M|  4101M|       |  1513  (53)| 00:00:19 |
|   1 |  DELETE                          | GV_BOOKS         |       |       |       |            |          |
|*  2 |   HASH JOIN                      |                  |   110M|  4101M|  2120K|  1513  (53)| 00:00:19 |
|   3 |    VIEW                          | VW_NSO_1         | 86600 |  1099K|       |   372   (3)| 00:00:05 |
|   4 |     MINUS                        |                  |       |       |       |            |          |
|   5 |      MINUS                       |                  |       |       |       |            |          |
|   6 |       SORT UNIQUE                |                  | 86600 |   338K|  1032K|            |          |
|   7 |        TABLE ACCESS FULL         | GV_BOOKS         | 86600 |   338K|       |   103   (1)| 00:00:02 |
|   8 |       SORT UNIQUE                |                  |    87 |  3393 |       |            |          |
|*  9 |        HASH JOIN                 |                  |    87 |  3393 |       |     7  (15)| 00:00:01 |
|* 10 |         TABLE ACCESS FULL        | GV_ACCOUNTS      |    87 |  2001 |       |     3   (0)| 00:00:01 |
|  11 |         TABLE ACCESS FULL        | BP_ACCOUNT       |    87 |  1392 |       |     3   (0)| 00:00:01 |
|  12 |      SORT UNIQUE                 |                  |    81 |  7776 |       |            |          |
|* 13 |       HASH JOIN                  |                  |    81 |  7776 |       |     6  (17)| 00:00:01 |
|  14 |        NESTED LOOPS OUTER        |                  |    81 |  5913 |       |     3  (34)| 00:00:01 |
|  15 |         NESTED LOOPS OUTER       |                  |    81 |  4860 |       |     3  (34)| 00:00:01 |
|  16 |          NESTED LOOPS OUTER      |                  |    81 |  3807 |       |     3  (34)| 00:00:01 |
|  17 |           NESTED LOOPS OUTER     |                  |    81 |  2754 |       |     3  (34)| 00:00:01 |
|  18 |            VIEW                  | index$_join$_009 |    81 |  1701 |       |     3  (34)| 00:00:01 |
|* 19 |             HASH JOIN            |                  |       |       |       |            |          |
|  20 |              INDEX FAST FULL SCAN| IX_CB_ACC_NO     |    81 |  1701 |       |     1   (0)| 00:00:01 |
|  21 |              INDEX FAST FULL SCAN| PK_CB_ACCOUNT    |    81 |  1701 |       |     1   (0)| 00:00:01 |
|* 22 |            INDEX UNIQUE SCAN     | ACCOUNT_EXT_KEY  |     1 |    13 |       |     0   (0)| 00:00:01 |
|* 23 |           INDEX UNIQUE SCAN      | ACCOUNT_EXT_KEY  |     1 |    13 |       |     0   (0)| 00:00:01 |
|* 24 |          INDEX UNIQUE SCAN       | ACCOUNT_EXT_KEY  |     1 |    13 |       |     0   (0)| 00:00:01 |
|* 25 |         INDEX UNIQUE SCAN        | ACCOUNT_EXT_KEY  |     1 |    13 |       |     0   (0)| 00:00:01 |
|* 26 |        TABLE ACCESS FULL         | GV_ACCOUNTS      |    87 |  2001 |       |     3   (0)| 00:00:01 |
|  27 |    TABLE ACCESS FULL             | GV_BOOKS         | 86600 |  2198K|       |   104   (2)| 00:00:02 |
-------------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - access("ACCOUNTID"="ACCOUNTID")
   9 - access("A"."ACCOUNTNO"="ACNTNO")
  10 - filter("A"."DBLINK"='90')
  13 - access("A"."ACCOUNTNO"="A"."ACCOUNT_NO")
  19 - access(ROWID=ROWID)
  22 - access("A"."ACCOUNT_ID"="E"."ACCOUNT_ID"(+) AND "E"."EXT_KEY"(+)='FEEMODE2')
  23 - access("A"."ACCOUNT_ID"="B"."ACCOUNT_ID"(+) AND "B"."EXT_KEY"(+)='CALCINTR')
  24 - access("A"."ACCOUNT_ID"="C"."ACCOUNT_ID"(+) AND "C"."EXT_KEY"(+)='DAYMODE')
  25 - access("A"."ACCOUNT_ID"="D"."ACCOUNT_ID"(+) AND "D"."EXT_KEY"(+)='FEEMODE1')
  26 - filter("A"."DBLINK"='90')