基于advisor优化工具的一次sql优化

问题背景：

客户反馈升级补丁包后DB服务器CPU压力增致99%

 

解决思路：

1> 查看问题系统发现有大量的latch: cache buffers chains 等待；

latch:cache buffers chains出现的原因   

1、不够优化的SQL。   

大量逻辑读的SQL语句就有可能产生非常严重的latch:cache buffers chains等待，因为每次要访问一个block，

就需要获得该latch，由于有大量的逻辑读，那么就增加了latch:cache buffers chains争用的机率。   

对于正在运行的SQL语句，产生非常严重的latch:cache buffers chains争用，可以利用下面SQL查看执行计划，并设法优化SQL语句。

1 select * from table(dbms_xplan.display_cursor('sql_id',sql_child_number));

如果SQL已经运行完毕，我们就看AWR报表里面的SQL Statistics->SQL ordered by Gets->Gets per Exec，试图优化这些SQL。

2、热点块争用  

查找数据库是否存在latch的争用

1 select sid,event,p1text,p1raw from v$session_wait where event='latch: cache buffers chains'

配合awr报告查看

可以确认确实有大量的latch：cache buffers chains 等待

 

2> 根据客户反馈昨天刚刚升级完毕补丁包并且补丁包里有

新上线的sql，怀疑是新的sql不够优化导致

首先把DB服务器的cpu降下来，kill latch: cache buffers chains 会话

复制代码
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 1 select 'alter system kill session ''' || a.sid || ',' || serial# || ''' immediate;'
 2   from v$session a
 3  where a.username='ECOLOGY' 
 4  AND a.STATUS='ACTIVE'    
 5  and event in('latch: cache buffers chains','latch free')
 6 
 7 alter system kill session '56,18142' ;
 8 alter system kill session '319,1510' ;
 9 alter system kill session '1462,17432' ;
10 alter system kill session '3456,2847' ;
11 alter system kill session '3457,1717' ;
12 alter system kill session '3458,16756' ;
13 alter system kill session '3739,7185' ;
14 alter system kill session '4000,2064' ;
复制代码
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3> 根据sql_id 查看问题sql的执行计划

SQL_ID  gj9y6g28qx8hw, child number 3

-------------------------------------

Plan hash value: 563984120

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

 

   1 - SEL$6D6869C2

   7 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$3

  10 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$4

  12 - SEL$6D6869C2 / T1@SEL$2

  13 - SEL$6D6869C2 / T2@SEL$2

  14 - SEL$6D6869C2 / T2@SEL$2

  15 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  16 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

 

Outline Data

-------------

 

  /*+

      BEGIN_OUTLINE_DATA

      IGNORE_OPTIM_EMBEDDED_HINTS

      OPTIMIZER_FEATURES_ENABLE('11.2.0.1')

      DB_VERSION('11.2.0.1')

      ALL_ROWS

      OUTLINE_LEAF(@"SEL$6D6869C2")

      UNNEST(@"SEL$3")

      UNNEST(@"SEL$4")

      UNNEST(@"SEL$5")

      OUTLINE(@"SEL$F5BB74E1")

      MERGE(@"SEL$2")

      OUTLINE(@"SEL$3")

      OUTLINE(@"SEL$4")

      OUTLINE(@"SEL$5")

      OUTLINE(@"SEL$1")

      OUTLINE(@"SEL$2")

      INDEX(@"SEL$6D6869C2" "WORKFLOWCENTERSETTINGDETAIL"@"SEL$3" ("WORKFLOWCENTERSETTINGDETAIL"."EID" 

              "WORKFLOWCENTERSETTINGDETAIL"."TABID" "WORKFLOWCENTERSETTINGDETAIL"."TYPE" 

              "WORKFLOWCENTERSETTINGDETAIL"."CONTENT"))

      INDEX(@"SEL$6D6869C2" "WORKFLOWCENTERSETTINGDETAIL"@"SEL$4" ("WORKFLOWCENTERSETTINGDETAIL"."EID" 

              "WORKFLOWCENTERSETTINGDETAIL"."TABID" "WORKFLOWCENTERSETTINGDETAIL"."TYPE" 

              "WORKFLOWCENTERSETTINGDETAIL"."CONTENT"))

      FULL(@"SEL$6D6869C2" "T1"@"SEL$2")

      INDEX_RS_ASC(@"SEL$6D6869C2" "T2"@"SEL$2" ("WORKFLOW_CURRENTOPERATOR"."REQUESTID" 

              "WORKFLOW_CURRENTOPERATOR"."USERID" "WORKFLOW_CURRENTOPERATOR"."WORKFLOWID"))

      INDEX_RS_ASC(@"SEL$6D6869C2" "WORKFLOW_BASE"@"SEL$5" ("WORKFLOW_BASE"."ID"))

      LEADING(@"SEL$6D6869C2" "WORKFLOWCENTERSETTINGDETAIL"@"SEL$3" "WORKFLOWCENTERSETTINGDETAIL"@"SEL$4" 

              "T1"@"SEL$2" "T2"@"SEL$2" "WORKFLOW_BASE"@"SEL$5")

      USE_MERGE(@"SEL$6D6869C2" "WORKFLOWCENTERSETTINGDETAIL"@"SEL$4")

      USE_MERGE_CARTESIAN(@"SEL$6D6869C2" "T1"@"SEL$2")

      USE_NL(@"SEL$6D6869C2" "T2"@"SEL$2")

      USE_NL(@"SEL$6D6869C2" "WORKFLOW_BASE"@"SEL$5")

      END_OUTLINE_DATA

  */

 

Predicate Information (identified by operation id):

---------------------------------------------------

 

   7 - access("EID"=962 AND "TABID"=5 AND "TYPE"='typeid')

  10 - access("EID"=962 AND "TABID"=5 AND "TYPE"='flowid')

  12 - filter((("T1"."DELETED"=0 OR "T1"."DELETED" IS NULL) AND ("T1"."CURRENTSTATUS" IS NULL OR 

              "T1"."CURRENTSTATUS"<>1)))

  13 - filter(("T2"."VIEWTYPE"=0 AND "T2"."ISLASTTIMES"=1 AND INTERNAL_FUNCTION("T2"."ISREMARK") AND 

 

可以看出执行计划非常糟糕，这次不手工调优，尝试使用advisor工具

调优建议如下：

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复制代码
  1 GENERAL INFORMATION SECTION
  2 
  3 -------------------------------------------------------------------------------
  4 
  5 Tuning Task Name   : staName58179
  6 
  7 Tuning Task Owner  : username
  8 
  9 Tuning Task ID     : 20591
 10 
 11 Workload Type      : Single SQL Statement
 12 
 13 Execution Count    : 1
 14 
 15 Current Execution  : EXEC_18371
 16 
 17 Execution Type     : TUNE SQL
 18 
 19 Scope              : COMPREHENSIVE
 20 
 21 Time Limit(seconds): 1800
 22 
 23 Completion Status  : COMPLETED
 24 
 25 Started at         : 10/17/2019 16:42:31
 26 
 27 Completed at       : 10/17/2019 16:42:35
 28 
 29  
 30 
 31 -------------------------------------------------------------------------------
 32 
 33 Schema Name: username
 34 
 35 SQL ID     : 48k1mg3r7vqms
 36 
 37 SQL Text   : 
 38 
 39 -------------------------------------------------------------------------------
 40 
 41 FINDINGS SECTION (2 findings)
 42 
 43 -------------------------------------------------------------------------------
 44 
 45  
 46 
 47 1- Statistics Finding     
 48 
 49 --------------------- 
 50 
 51   表 "username"."table_name" 的优化程序统计信息已失效。
 52 
 53  
 54 
 55   Recommendation
 56 
 57   --------------
 58 
 59   - 考虑收集此表及其索引的优化程序统计信息。
 60 
 61     execute dbms_stats.gather_table_stats(ownname => 'username', tabname =>
 62 
 63             'table_name', estimate_percent =>
 64 
 65             DBMS_STATS.AUTO_SAMPLE_SIZE, method_opt => 'FOR ALL COLUMNS SIZE
 66 
 67             AUTO', cascade => TRUE);
 68 
 69  
 70 
 71   Rationale
 72 
 73   ---------
 74 
 75     为了选择好的执行计划, 优化程序需要此表及其索引的最新统计信息。
 76 
 77  
 78 
 79 2- SQL Profile Finding (see explain plans section below)
 80 
 81 --------------------------------------------------------
 82 
 83   为此语句找到了性能更好的执行计划。
 84 
 85  
 86 
 87   Recommendation (estimated benefit: 99.95%)
 88 
 89   ------------------------------------------
 90 
 91   - 考虑接受推荐的 SQL 概要文件。
 92 
 93     execute dbms_sqltune.accept_sql_profile(task_name => 'staName58179',
 94 
 95             task_owner => 'username', replace => TRUE);
 96 
 97  
 98 
 99   Validation results
100 
101   ------------------
102 
103   已对 SQL profile 进行测试, 方法为执行其计划和原始计划并测量与计划相对应的执行统计信息。如果其中一个计划运行在很短的时间内就完成,
104 
105   则另一计划可能只执行了一部分。
106 
107  
108 
109                            Original Plan  With SQL Profile  % Improved
110 
111                            -------------  ----------------  ----------
112 
113   Completion Status:            COMPLETE          COMPLETE
114 
115   Elapsed Time(us):               76070               265      99.65 %
116 
117   CPU Time(us):                   61690               299      99.51 %
118 
119   User I/O Time(us):                  0                 0 
120 
121   Buffer Gets:                    36545                17      99.95 %
122 
123   Physical Read Requests:             0                 0 
124 
125   Physical Write Requests:            0                 0 
126 
127   Physical Read Bytes:                0                 0 
128 
129   Physical Write Bytes:               0                 0 
130 
131   Rows Processed:                     1                 1 
132 
133   Fetches:                            1                 1 
134 
135   Executions:                         1                 1 
136 
137  
138 
139   Notes
140 
141   -----
142 
143   1. original plan 已首先执行以预热缓冲区高速缓存。
144 
145   2. original plan 的统计信息是后面的 9 执行的平均值。
146 
147   3. SQL profile plan 已首先执行以预热缓冲区高速缓存。
148 
149   4. the SQL profile plan 的统计信息是后面的 9 执行的平均值。
复制代码
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-------------------------------------------------------------------------------

EXPLAIN PLANS SECTION

-------------------------------------------------------------------------------

1- Original

-----------

Plan hash value: 2478385950

 

 

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

 

   1 - SEL$6D6869C2

   8 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$3

  11 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$4

  13 - SEL$6D6869C2 / T2@SEL$2

  14 - SEL$6D6869C2 / T2@SEL$2

  15 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  16 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  17 - SEL$6D6869C2 / T1@SEL$2

  18 - SEL$6D6869C2 / T1@SEL$2

 

Predicate Information (identified by operation id):

---------------------------------------------------

 

   8 - access("EID"=962 AND "TABID"=5 AND "TYPE"='typeid')

  11 - access("EID"=962 AND "TABID"=5 AND "TYPE"='flowid')

  13 - filter("T2"."VIEWTYPE"=0 AND "T2"."ISLASTTIMES"=1 AND "T2"."WORKFLOWTYPE"=TO_NUMBER("CONTENT") AND 

              "T2"."WORKFLOWID"=TO_NUMBER("CONTENT"))

  14 - access(("T2"."ISREMARK"='7' OR "T2"."ISREMARK"='8' OR "T2"."ISREMARK"='9') AND "T2"."USERID"=695 

              AND "T2"."USERTYPE"=0)

  15 - filter("ISVALID"='1' OR "ISVALID"='3')

  16 - access("T2"."WORKFLOWID"="ID")

  17 - access("T1"."REQUESTID"="T2"."REQUESTID")

  18 - filter(("T1"."DELETED"=0 OR "T1"."DELETED" IS NULL) AND ("T1"."CURRENTSTATUS" IS NULL OR 

              "T1"."CURRENTSTATUS"<>1))

 

Column Projection Information (identified by operation id):

-----------------------------------------------------------

 

   1 - (#keys=0) COUNT(*)[22]

   2 - (#keys=0) 

   3 - (#keys=0) "T1".ROWID[ROWID,10]

   4 - (#keys=0) "T2"."REQUESTID"[NUMBER,22]

   5 - (#keys=0) "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

   6 - (#keys=0) TO_NUMBER("CONTENT")[22], TO_NUMBER("CONTENT")[22]

   7 - (#keys=1) TO_NUMBER("CONTENT")[22]

   8 - "CONTENT"[VARCHAR2,100]

   9 - (#keys=0) TO_NUMBER("CONTENT")[22]

  10 - (#keys=1) TO_NUMBER("CONTENT")[22]

  11 - "CONTENT"[VARCHAR2,100]

  12 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

  13 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

  14 - "T2".ROWID[ROWID,10]

  16 - "WORKFLOW_BASE".ROWID[ROWID,10]

  17 - "T1".ROWID[ROWID,10]

 

2- Original With Adjusted Cost

------------------------------

Plan hash value: 2478385950

 

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

 

   1 - SEL$6D6869C2

   8 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$3

  11 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$4

  13 - SEL$6D6869C2 / T2@SEL$2

  14 - SEL$6D6869C2 / T2@SEL$2

  15 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  16 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  17 - SEL$6D6869C2 / T1@SEL$2

  18 - SEL$6D6869C2 / T1@SEL$2

 

Predicate Information (identified by operation id):

---------------------------------------------------

 

   8 - access("EID"=962 AND "TABID"=5 AND "TYPE"='typeid')

  11 - access("EID"=962 AND "TABID"=5 AND "TYPE"='flowid')

  13 - filter("T2"."VIEWTYPE"=0 AND "T2"."ISLASTTIMES"=1 AND "T2"."WORKFLOWTYPE"=TO_NUMBER("CONTENT") AND 

              "T2"."WORKFLOWID"=TO_NUMBER("CONTENT"))

  14 - access(("T2"."ISREMARK"='7' OR "T2"."ISREMARK"='8' OR "T2"."ISREMARK"='9') AND "T2"."USERID"=695 

              AND "T2"."USERTYPE"=0)

  15 - filter("ISVALID"='1' OR "ISVALID"='3')

  16 - access("T2"."WORKFLOWID"="ID")

  17 - access("T1"."REQUESTID"="T2"."REQUESTID")

  18 - filter(("T1"."DELETED"=0 OR "T1"."DELETED" IS NULL) AND ("T1"."CURRENTSTATUS" IS NULL OR 

              "T1"."CURRENTSTATUS"<>1))

 

Column Projection Information (identified by operation id):

-----------------------------------------------------------

 

   1 - (#keys=0) COUNT(*)[22]

   2 - (#keys=0) 

   3 - (#keys=0) "T1".ROWID[ROWID,10]

   4 - (#keys=0) "T2"."REQUESTID"[NUMBER,22]

   5 - (#keys=0) "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

   6 - (#keys=0) TO_NUMBER("CONTENT")[22], TO_NUMBER("CONTENT")[22]

   7 - (#keys=1) TO_NUMBER("CONTENT")[22]

   8 - "CONTENT"[VARCHAR2,100]

   9 - (#keys=0) TO_NUMBER("CONTENT")[22]

  10 - (#keys=1) TO_NUMBER("CONTENT")[22]

  11 - "CONTENT"[VARCHAR2,100]

  12 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

  13 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

  14 - "T2".ROWID[ROWID,10]

  16 - "WORKFLOW_BASE".ROWID[ROWID,10]

  17 - "T1".ROWID[ROWID,10]

 

3- Using SQL Profile

--------------------

Plan hash value: 1474559118

 

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

 

   1 - SEL$6D6869C2

   7 - SEL$6D6869C2 / T2@SEL$2

   8 - SEL$6D6869C2 / T2@SEL$2

   9 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$3

  10 - SEL$6D6869C2 / T1@SEL$2

  11 - SEL$6D6869C2 / T1@SEL$2

  12 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  13 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  14 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$4

 

Predicate Information (identified by operation id):

---------------------------------------------------

 

   5 - access("T2"."WORKFLOWTYPE"=TO_NUMBER("CONTENT"))

   7 - filter("T2"."VIEWTYPE"=0 AND "T2"."ISLASTTIMES"=1)

   8 - access(("T2"."ISREMARK"='7' OR "T2"."ISREMARK"='8' OR "T2"."ISREMARK"='9') AND "T2"."USERID"=695 

              AND "T2"."USERTYPE"=0)

   9 - access("EID"=962 AND "TABID"=5 AND "TYPE"='typeid')

  10 - filter(("T1"."DELETED"=0 OR "T1"."DELETED" IS NULL) AND ("T1"."CURRENTSTATUS" IS NULL OR 

              "T1"."CURRENTSTATUS"<>1))

  11 - access("T1"."REQUESTID"="T2"."REQUESTID")

  12 - filter("ISVALID"='1' OR "ISVALID"='3')

  13 - access("T2"."WORKFLOWID"="ID")

  14 - access("EID"=962 AND "TABID"=5 AND "TYPE"='flowid')

       filter("T2"."WORKFLOWID"=TO_NUMBER("CONTENT"))

 

Column Projection Information (identified by operation id):

-----------------------------------------------------------

 

   1 - (#keys=0) COUNT(*)[22]

   2 - (#keys=0) 

   3 - (#keys=0) "T2"."WORKFLOWID"[NUMBER,22]

   4 - (#keys=0) "T2"."WORKFLOWID"[NUMBER,22]

   5 - (#keys=1) "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

   6 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22], "T2"."WORKFLOWTYPE"[NUMBER,22]

   7 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22], "T2"."WORKFLOWTYPE"[NUMBER,22]

   8 - "T2".ROWID[ROWID,10]

   9 - "CONTENT"[VARCHAR2,100]

  11 - "T1".ROWID[ROWID,10]

  13 - "WORKFLOW_BASE".ROWID[ROWID,10]

 

-------------------------------------------------------------------------------

 

advisor建议收集统计信息

execute dbms_stats.gather_table_stats(ownname => 'username', tabname => 'table_name', estimate_percent => DBMS_STATS.AUTO_SAMPLE_SIZE, method_opt => 'FOR ALL COLUMNS SIZE AUTO', cascade => TRUE);

建议绑定良好的执行计划

execute dbms_sqltune.accept_sql_profile(task_name => 'staName58179',task_owner => 'usrename', replace => TRUE);

 

4> 根据advisor给出的建议实际查看相关表是否统计信息失效，确实发现相关表的统计信息失效，收集完毕统计信息再次执行advisor测试

 

GENERAL INFORMATION SECTION

-------------------------------------------------------------------------------

Tuning Task Name   : staName86486

Tuning Task Owner  : username

Tuning Task ID     : 20592

Workload Type      : Single SQL Statement

Execution Count    : 1

Current Execution  : EXEC_18372

Execution Type     : TUNE SQL

Scope              : COMPREHENSIVE

Time Limit(seconds): 1800

Completion Status  : COMPLETED

Started at         : 10/17/2019 16:48:25

Completed at       : 10/17/2019 16:48:26

 

-------------------------------------------------------------------------------

Schema Name: username

SQL ID     : 48k1mg3r7vqms

SQL Text   : 

-------------------------------------------------------------------------------

ADDITIONAL INFORMATION SECTION

-------------------------------------------------------------------------------

- 此语句的 SQL 概要文件 "SYS_SQLPROF_016dd8e4cbcb0000" 已存在, 但在优化时被忽略。

-------------------------------------------------------------------------------

EXPLAIN PLANS SECTION

-------------------------------------------------------------------------------

 

1- Original

-----------

Plan hash value: 1474559118

 

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

 

   1 - SEL$6D6869C2

   7 - SEL$6D6869C2 / T2@SEL$2

   8 - SEL$6D6869C2 / T2@SEL$2

   9 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$3

  10 - SEL$6D6869C2 / T1@SEL$2

  11 - SEL$6D6869C2 / T1@SEL$2

  12 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  13 - SEL$6D6869C2 / WORKFLOW_BASE@SEL$5

  14 - SEL$6D6869C2 / WORKFLOWCENTERSETTINGDETAIL@SEL$4

 

Predicate Information (identified by operation id):

---------------------------------------------------

 

   5 - access("T2"."WORKFLOWTYPE"=TO_NUMBER("CONTENT"))

   7 - filter("T2"."VIEWTYPE"=0 AND "T2"."ISLASTTIMES"=1)

   8 - access(("T2"."ISREMARK"='7' OR "T2"."ISREMARK"='8' OR "T2"."ISREMARK"='9') AND "T2"."USERID"=695 

              AND "T2"."USERTYPE"=0)

   9 - access("EID"=962 AND "TABID"=5 AND "TYPE"='typeid')

  10 - filter(("T1"."DELETED"=0 OR "T1"."DELETED" IS NULL) AND ("T1"."CURRENTSTATUS" IS NULL OR 

              "T1"."CURRENTSTATUS"<>1))

  11 - access("T1"."REQUESTID"="T2"."REQUESTID")

  12 - filter("ISVALID"='1' OR "ISVALID"='3')

  13 - access("T2"."WORKFLOWID"="ID")

  14 - access("EID"=962 AND "TABID"=5 AND "TYPE"='flowid')

       filter("T2"."WORKFLOWID"=TO_NUMBER("CONTENT"))

 

Column Projection Information (identified by operation id):

-----------------------------------------------------------

 

   1 - (#keys=0) COUNT(*)[22]

   2 - (#keys=0) 

   3 - (#keys=0) "T2"."WORKFLOWID"[NUMBER,22]

   4 - (#keys=0) "T2"."WORKFLOWID"[NUMBER,22]

   5 - (#keys=1) "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22]

   6 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22], "T2"."WORKFLOWTYPE"[NUMBER,22]

   7 - "T2"."REQUESTID"[NUMBER,22], "T2"."WORKFLOWID"[NUMBER,22], "T2"."WORKFLOWTYPE"[NUMBER,22]

   8 - "T2".ROWID[ROWID,10]

   9 - "CONTENT"[VARCHAR2,100]

  11 - "T1".ROWID[ROWID,10]

  13 - "WORKFLOW_BASE".ROWID[ROWID,10]

 

Note

-----

   - SQL profile "SYS_SQLPROF_016dd8e4cbcb0000" used for this statement

 

-------------------------------------------------------------------------------

advisor工具没有给出合理的调整，说明advisor工具判断目前的sql执行计划良好，再次执行相关sql结果秒出

查看DB服务器负载已经正常，调优成功

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