♣题目 部分
在Oracle中，如何使用STA来生成SQL Profile？
♣答案部分
利用STA对语句进行优化后，STA会对语句进行分析，采用最优的优化策略，并给出优化后的查询计划。可以按照STA给出的建议重写语句。但是，有些情况下，你可能无法重写语句（比如在生产环境中，SQL语句又在一个包中）。这个时候就可以利用Sql Profile，将优化策略存储在Profile中，Oracle在构建这条语句的查询计划时，就不会使用已有相关统计数据，而使用Profile的策略，生成新的查询计划。
第一步：给用户赋权限
1[ZHLHRSPMDB2:oracle]:/oracle>sqlplus / as sysdba 2 3SQL*Plus: Release 11.2.0.4.0 Production on Wed May 25 16:47:29 2016 4 5Copyright (c) 1982, 2013, Oracle. All rights reserved. 6 7 8Connected to: 9Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production 10With the Partitioning, Real Application Clusters, OLAP, Data Mining 11and Real Application Testing options 12 13SYS@dlhr> 14SYS@dlhr> 15SYS@dlhr> 16SYS@dlhr> GRANT CREATE ANY SQL PROFILE TO LHR; 17 18Grant succeeded. 19 20SYS@dlhr> GRANT DROP ANY SQL PROFILE TO LHR; 21 22Grant succeeded. 23 24SYS@dlhr> GRANT ALTER ANY SQL PROFILE TO LHR; 25 26Grant succeeded. 27 28SYS@dlhr> conn lhr/lhr 29Connected. 30LHR@dlhr> 31LHR@dlhr> select * from v$version; 32 33BANNER 34-------------------------------------------------------------------------------- 35Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production 36PL/SQL Release 11.2.0.4.0 - Production 37CORE 11.2.0.4.0 Production 38TNS for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production 39NLSRTL Version 11.2.0.4.0 - Production 40 41LHR@dlhr> create table lhr.TB_LHR_20160525_01 as select * from dba_objects; 42 43Table created. 44 45LHR@dlhr> create index lhr.TB_LHR_20160525_01_idx on TB_LHR_20160525_01(object_id); 46 47Index created. 48 49LHR@dlhr> exec dbms_stats.gather_table_stats('lhr','TB_LHR_20160525_01',cascade=>true,degree=>4); 50 51PL/SQL procedure successfully completed. 52 53LHR@dlhr> set autot on 54LHR@dlhr> select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100 ; 55 56 COUNT(*) 57---------- 58 1 59 60 61Execution Plan 62---------------------------------------------------------- 63Plan hash value: 3612989399 64 65----------------------------------------------------------------------------------------- 66| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | 67----------------------------------------------------------------------------------------- 68| 0 | SELECT STATEMENT | | 1 | 5 | 351 (2)| 00:00:05 | 69| 1 | SORT AGGREGATE | | 1 | 5 | | | 70|* 2 | TABLE ACCESS FULL| TB_LHR_20160525_01 | 1 | 5 | 351 (2)| 00:00:05 | 71----------------------------------------------------------------------------------------- 72 73Predicate Information (identified by operation id): 74--------------------------------------------------- 75 76 2 - filter("OBJECT_ID"=100) 77 78 79Statistics 80---------------------------------------------------------- 81 1 recursive calls 82 0 db block gets 83 1249 consistent gets 84 0 physical reads 85 0 redo size 86 526 bytes sent via SQL*Net to client 87 520 bytes received via SQL*Net from client 88 2 SQL*Net roundtrips to/from client 89 0 sorts (memory) 90 0 sorts (disk) 91 1 rows processed 92LHR@dlhr> set autot off 93LHR@dlhr> SELECT v.SQL_ID, v.SQL_TEXT FROM v$sql v WHERE v.SQL_TEXT like '%no_index(TB_LHR_20160525_01%' and v.SQL_TEXT not like '%v$sql%' ; 94 95SQL_ID 96------------- 97SQL_TEXT 98------------------------------------------------------------------------------------------------------------------------------------ 997jt1btjkcczb8100select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 1001011027suktf0w95cry103EXPLAIN PLAN SET STATEMENT_ID='PLUS150249' FOR select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_L104HR_20160525_01 where object_id = 100
2
3SQL*Plus: Release 11.2.0.4.0 Production on Wed May 25 16:47:29 2016
4
5Copyright (c) 1982, 2013, Oracle. All rights reserved.
6
7
8Connected to:
9Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
10With the Partitioning, Real Application Clusters, OLAP, Data Mining
11and Real Application Testing options
12
13SYS@dlhr>
14SYS@dlhr>
15SYS@dlhr>
16SYS@dlhr> GRANT CREATE ANY SQL PROFILE TO LHR;
17
18Grant succeeded.
19
20SYS@dlhr> GRANT DROP ANY SQL PROFILE TO LHR;
21
22Grant succeeded.
23
24SYS@dlhr> GRANT ALTER ANY SQL PROFILE TO LHR;
25
26Grant succeeded.
27
28SYS@dlhr> conn lhr/lhr
29Connected.
30LHR@dlhr>
31LHR@dlhr> select * from v$version;
32
33BANNER
34--------------------------------------------------------------------------------
35Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
36PL/SQL Release 11.2.0.4.0 - Production
37CORE 11.2.0.4.0 Production
38TNS for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production
39NLSRTL Version 11.2.0.4.0 - Production
40
41LHR@dlhr> create table lhr.TB_LHR_20160525_01 as select * from dba_objects;
42
43Table created.
44
45LHR@dlhr> create index lhr.TB_LHR_20160525_01_idx on TB_LHR_20160525_01(object_id);
46
47Index created.
48
49LHR@dlhr> exec dbms_stats.gather_table_stats('lhr','TB_LHR_20160525_01',cascade=>true,degree=>4);
50
51PL/SQL procedure successfully completed.
52
53LHR@dlhr> set autot on
54LHR@dlhr> select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100 ;
55
56 COUNT(*)
57----------
58 1
59
60
61Execution Plan
62----------------------------------------------------------
63Plan hash value: 3612989399
64
65-----------------------------------------------------------------------------------------
66| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
67-----------------------------------------------------------------------------------------
68| 0 | SELECT STATEMENT | | 1 | 5 | 351 (2)| 00:00:05 |
69| 1 | SORT AGGREGATE | | 1 | 5 | | |
70|* 2 | TABLE ACCESS FULL| TB_LHR_20160525_01 | 1 | 5 | 351 (2)| 00:00:05 |
71-----------------------------------------------------------------------------------------
72
73Predicate Information (identified by operation id):
74---------------------------------------------------
75
76 2 - filter("OBJECT_ID"=100)
77
78
79Statistics
80----------------------------------------------------------
81 1 recursive calls
82 0 db block gets
83 1249 consistent gets
84 0 physical reads
85 0 redo size
86 526 bytes sent via SQL*Net to client
87 520 bytes received via SQL*Net from client
88 2 SQL*Net roundtrips to/from client
89 0 sorts (memory)
90 0 sorts (disk)
91 1 rows processed
92LHR@dlhr> set autot off
93LHR@dlhr> SELECT v.SQL_ID, v.SQL_TEXT FROM v$sql v WHERE v.SQL_TEXT like '%no_index(TB_LHR_20160525_01%' and v.SQL_TEXT not like '%v$sql%' ;
94
95SQL_ID
96-------------
97SQL_TEXT
98------------------------------------------------------------------------------------------------------------------------------------
997jt1btjkcczb8
100select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100
101
1027suktf0w95cry
103EXPLAIN PLAN SET STATEMENT_ID='PLUS150249' FOR select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_L
104HR_20160525_01 where object_id = 100
第二步：创建、执行优化任务
1LHR@dlhr> DECLARE 2 2 my_task_name VARCHAR2(30); 3 3 my_sqltext CLOB; 4 4 BEGIN 5 5 my_sqltext := 'select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100'; 6 6 my_task_name := DBMS_SQLTUNE.CREATE_TUNING_TASK( 7 7 sql_text => my_sqltext, 8 8 user_name => 'LHR', 9 9 scope => 'COMPREHENSIVE',10 10 time_limit => 60,11 11 task_name => 'sql_profile_test',12 12 description => 'Task to tune a query on a specified table');13 13 DBMS_SQLTUNE.EXECUTE_TUNING_TASK( task_name => 'sql_profile_test');14 14 END;15 15 /1617PL/SQL procedure successfully completed.DECLARE
2 2 my_task_name VARCHAR2(30);
3 3 my_sqltext CLOB;
4 4 BEGIN
5 5 my_sqltext := 'select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100';
6 6 my_task_name := DBMS_SQLTUNE.CREATE_TUNING_TASK(
7 7 sql_text => my_sqltext,
8 8 user_name => 'LHR',
9 9 scope => 'COMPREHENSIVE',
10 10 time_limit => 60,
11 11 task_name => 'sql_profile_test',
12 12 description => 'Task to tune a query on a specified table');
13 13 DBMS_SQLTUNE.EXECUTE_TUNING_TASK( task_name => 'sql_profile_test');
14 14 END;
15 15 /
16
17PL/SQL procedure successfully completed.
或者也可以使用sqlid来生成优化任务，如下：
1LHR@dlhr> DECLARE 2 2 a_tuning_task VARCHAR2(30); 3 3 BEGIN 4 4 a_tuning_task := dbms_sqltune.create_tuning_task(sql_id => '7jt1btjkcczb8', 5 5 task_name => 'sql_profile_test_SQLID'); 6 6 dbms_sqltune.execute_tuning_task(a_tuning_task); 7 7 END; 8 8 / 910PL/SQL procedure successfully completed.DECLARE
2 2 a_tuning_task VARCHAR2(30);
3 3 BEGIN
4 4 a_tuning_task := dbms_sqltune.create_tuning_task(sql_id => '7jt1btjkcczb8',
5 5 task_name => 'sql_profile_test_SQLID');
6 6 dbms_sqltune.execute_tuning_task(a_tuning_task);
7 7 END;
8 8 /
9
10PL/SQL procedure successfully completed.
第三步：查看优化建议
1LHR@dlhr> set autot off 2LHR@dlhr> set long 10000 3LHR@dlhr> set longchunksize 1000 4LHR@dlhr> set linesize 100 5LHR@dlhr> SELECT DBMS_SQLTUNE.REPORT_TUNING_TASK( 'sql_profile_test') from DUAL; 6 7DBMS_SQLTUNE.REPORT_TUNING_TASK('SQL_PROFILE_TEST') 8---------------------------------------------------------------------------------------------------- 9GENERAL INFORMATION SECTION 10------------------------------------------------------------------------------- 11Tuning Task Name : sql_profile_test 12Tuning Task Owner : LHR 13Workload Type : Single SQL Statement 14Scope : COMPREHENSIVE 15Time Limit(seconds): 60 16Completion Status : COMPLETED 17Started at : 05/25/2016 16:58:31 18Completed at : 05/25/2016 16:58:32 19 20------------------------------------------------------------------------------- 21Schema Name: LHR 22SQL ID : 9kzm8scz6t92z 23SQL Text : select /*+no_index(TB_LHR_20160525_01 24 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 25 where object_id = 100 26 27------------------------------------------------------------------------------- 28FINDINGS SECTION (1 finding) 29------------------------------------------------------------------------------- 30 311- SQL Profile Finding (see explain plans section below) 32-------------------------------------------------------- 33 A potentially better execution plan was found for this statement. 34 35 Recommendation (estimated benefit: 99.83%) 36 ------------------------------------------ 37 - Consider accepting the recommended SQL profile. 38 execute dbms_sqltune.accept_sql_profile(task_name => 'sql_profile_test', 39 task_owner => 'LHR', replace => TRUE); 40 41 Validation results 42 ------------------ 43 The SQL profile was tested by executing both its plan and the original plan 44 and measuring their respective execution statistics. A plan may have been 45 only partially executed if the other could be run to completion in less time. 46 47 Original Plan With SQL Profile % Improved 48 ------------- ---------------- ---------- 49 Completion Status: COMPLETE COMPLETE 50 Elapsed Time (s): .006278 .00004 99.36 % 51 CPU Time (s): .003397 .000021 99.38 % 52 User I/O Time (s): 0 0 53 Buffer Gets: 1249 2 99.83 % 54 Physical Read Requests: 0 0 55 Physical Write Requests: 0 0 56 57DBMS_SQLTUNE.REPORT_TUNING_TASK('SQL_PROFILE_TEST') 58---------------------------------------------------------------------------------------------------- 59 Physical Read Bytes: 0 0 60 Physical Write Bytes: 0 0 61 Rows Processed: 1 1 62 Fetches: 1 1 63 Executions: 1 1 64 65 Notes 66 ----- 67 1. Statistics for the original plan were averaged over 10 executions. 68 2. Statistics for the SQL profile plan were averaged over 10 executions. 69 70------------------------------------------------------------------------------- 71EXPLAIN PLANS SECTION 72------------------------------------------------------------------------------- 73 741- Original With Adjusted Cost 75------------------------------ 76Plan hash value: 3612989399 77 78----------------------------------------------------------------------------------------- 79| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | 80----------------------------------------------------------------------------------------- 81| 0 | SELECT STATEMENT | | 1 | 5 | 351 (2)| 00:00:05 | 82| 1 | SORT AGGREGATE | | 1 | 5 | | | 83|* 2 | TABLE ACCESS FULL| TB_LHR_20160525_01 | 1 | 5 | 351 (2)| 00:00:05 | 84----------------------------------------------------------------------------------------- 85 86Predicate Information (identified by operation id): 87--------------------------------------------------- 88 89 2 - filter("OBJECT_ID"=100) 90 912- Using SQL Profile 92-------------------- 93Plan hash value: 661515879 94 95-------------------------------------------------------------------------------------------- 96| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | 97-------------------------------------------------------------------------------------------- 98| 0 | SELECT STATEMENT | | 1 | 5 | 1 (0)| 00:00:01 | 99| 1 | SORT AGGREGATE | | 1 | 5 | | |100|* 2 | INDEX RANGE SCAN| TB_LHR_20160525_01_IDX | 1 | 5 | 1 (0)| 00:00:01 |101--------------------------------------------------------------------------------------------102103Predicate Information (identified by operation id):104---------------------------------------------------105106107DBMS_SQLTUNE.REPORT_TUNING_TASK('SQL_PROFILE_TEST')108----------------------------------------------------------------------------------------------------109 2 - access("OBJECT_ID"=100)110111-------------------------------------------------------------------------------set autot off
2LHR@dlhr> set long 10000
3LHR@dlhr> set longchunksize 1000
4LHR@dlhr> set linesize 100
5LHR@dlhr> SELECT DBMS_SQLTUNE.REPORT_TUNING_TASK( 'sql_profile_test') from DUAL;
6
7DBMS_SQLTUNE.REPORT_TUNING_TASK('SQL_PROFILE_TEST')
8----------------------------------------------------------------------------------------------------
9GENERAL INFORMATION SECTION
10-------------------------------------------------------------------------------
11Tuning Task Name : sql_profile_test
12Tuning Task Owner : LHR
13Workload Type : Single SQL Statement
14Scope : COMPREHENSIVE
15Time Limit(seconds): 60
16Completion Status : COMPLETED
17Started at : 05/25/2016 16:58:31
18Completed at : 05/25/2016 16:58:32
19
20-------------------------------------------------------------------------------
21Schema Name: LHR
22SQL ID : 9kzm8scz6t92z
23SQL Text : select /*+no_index(TB_LHR_20160525_01
24 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01
25 where object_id = 100
26
27-------------------------------------------------------------------------------
28FINDINGS SECTION (1 finding)
29-------------------------------------------------------------------------------
30
311- SQL Profile Finding (see explain plans section below)
32--------------------------------------------------------
33 A potentially better execution plan was found for this statement.
34
35 Recommendation (estimated benefit: 99.83%)
36 ------------------------------------------
37 - Consider accepting the recommended SQL profile.
38 execute dbms_sqltune.accept_sql_profile(task_name => 'sql_profile_test',
39 task_owner => 'LHR', replace => TRUE);
40
41 Validation results
42 ------------------
43 The SQL profile was tested by executing both its plan and the original plan
44 and measuring their respective execution statistics. A plan may have been
45 only partially executed if the other could be run to completion in less time.
46
47 Original Plan With SQL Profile % Improved
48 ------------- ---------------- ----------
49 Completion Status: COMPLETE COMPLETE
50 Elapsed Time (s): .006278 .00004 99.36 %
51 CPU Time (s): .003397 .000021 99.38 %
52 User I/O Time (s): 0 0
53 Buffer Gets: 1249 2 99.83 %
54 Physical Read Requests: 0 0
55 Physical Write Requests: 0 0
56
57DBMS_SQLTUNE.REPORT_TUNING_TASK('SQL_PROFILE_TEST')
58----------------------------------------------------------------------------------------------------
59 Physical Read Bytes: 0 0
60 Physical Write Bytes: 0 0
61 Rows Processed: 1 1
62 Fetches: 1 1
63 Executions: 1 1
64
65 Notes
66 -----
67 1. Statistics for the original plan were averaged over 10 executions.
68 2. Statistics for the SQL profile plan were averaged over 10 executions.
69
70-------------------------------------------------------------------------------
71EXPLAIN PLANS SECTION
72-------------------------------------------------------------------------------
73
741- Original With Adjusted Cost
75------------------------------
76Plan hash value: 3612989399
77
78-----------------------------------------------------------------------------------------
79| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
80-----------------------------------------------------------------------------------------
81| 0 | SELECT STATEMENT | | 1 | 5 | 351 (2)| 00:00:05 |
82| 1 | SORT AGGREGATE | | 1 | 5 | | |
83|* 2 | TABLE ACCESS FULL| TB_LHR_20160525_01 | 1 | 5 | 351 (2)| 00:00:05 |
84-----------------------------------------------------------------------------------------
85
86Predicate Information (identified by operation id):
87---------------------------------------------------
88
89 2 - filter("OBJECT_ID"=100)
90
912- Using SQL Profile
92--------------------
93Plan hash value: 661515879
94
95--------------------------------------------------------------------------------------------
96| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
97--------------------------------------------------------------------------------------------
98| 0 | SELECT STATEMENT | | 1 | 5 | 1 (0)| 00:00:01 |
99| 1 | SORT AGGREGATE | | 1 | 5 | | |
100|* 2 | INDEX RANGE SCAN| TB_LHR_20160525_01_IDX | 1 | 5 | 1 (0)| 00:00:01 |
101--------------------------------------------------------------------------------------------
102
103Predicate Information (identified by operation id):
104---------------------------------------------------
105
106
107DBMS_SQLTUNE.REPORT_TUNING_TASK('SQL_PROFILE_TEST')
108----------------------------------------------------------------------------------------------------
109 2 - access("OBJECT_ID"=100)
110
111-------------------------------------------------------------------------------
这里可以看到，在优化建议中给出了新的查询计划。现在，我们决定接受这个建议，并且不重写语句。
第四步：接受profile
1LHR@dlhr> set autot on 2LHR@dlhr> select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100 ; 3 4 COUNT(*) 5---------- 6 1 7 8 9Execution Plan10----------------------------------------------------------1112Plan hash value: 36129893991314-----------------------------------------------------------------------------------------15| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |16-----------------------------------------------------------------------------------------17| 0 | SELECT STATEMENT | | 1 | 5 | 351 (2)| 00:00:05 |18| 1 | SORT AGGREGATE | | 1 | 5 | | |19|* 2 | TABLE ACCESS FULL| TB_LHR_20160525_01 | 1 | 5 | 351 (2)| 00:00:05 |20-----------------------------------------------------------------------------------------2122Predicate Information (identified by operation id):23---------------------------------------------------2425 2 - filter("OBJECT_ID"=100)262728Statistics29----------------------------------------------------------30 0 recursive calls31 0 db block gets32 1249 consistent gets33 0 physical reads34 0 redo size35 526 bytes sent via SQL*Net to client36 520 bytes received via SQL*Net from client37 2 SQL*Net roundtrips to/from client38 0 sorts (memory)39 0 sorts (disk)40 1 rows processed41LHR@dlhr> execute dbms_sqltune.accept_sql_profile(task_name =>'sql_profile_test_SQLID', task_owner => 'LHR', replace => TRUE);4243PL/SQL procedure successfully completed.4445LHR@dlhr> set autot off46LHR@dlhr> SELECT e.task_name, b.name, d.sql_text, extractvalue(value(h), '.') as hints47 2 FROM dba_sql_profiles d,48 3 dba_advisor_tasks e,49 4 SYS.SQLOBJ$DATA A,50 5 SYS.SQLOBJ$ B,51 6 TABLE(XMLSEQUENCE(EXTRACT(XMLTYPE(A.COMP_DATA),52 7 '/outline_data/hint'))) h53 8 where a.signature = b.signature54 9 and a.category = b.category55 10 and a.obj_type = b.obj_type56 11 and a.plan_id = b.plan_id57 12 and a.signature = d.signature 58 13 and d.task_id=e.task_id59 14 and d.name = 'SYS_SQLPROF_0154e728ad3f0000'60 15 ;6162TASK_NAME NAME63------------------------------ ------------------------------64SQL_TEXT65----------------------------------------------------------------------------------------------------66HINTS67----------------------------------------------------------------------------------------------------68sql_profile_test SYS_SQLPROF_0154e728ad3f000069select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_0170where object_id = 10071OPTIMIZER_FEATURES_ENABLE(default)7273sql_profile_test SYS_SQLPROF_0154e728ad3f000074select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_0175where object_id = 10076IGNORE_OPTIM_EMBEDDED_HINTSset autot on
2LHR@dlhr> select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100 ;
3
4 COUNT(*)
5----------
6 1
7
8
9Execution Plan
10----------------------------------------------------------
11
12Plan hash value: 3612989399
13
14-----------------------------------------------------------------------------------------
15| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
16-----------------------------------------------------------------------------------------
17| 0 | SELECT STATEMENT | | 1 | 5 | 351 (2)| 00:00:05 |
18| 1 | SORT AGGREGATE | | 1 | 5 | | |
19|* 2 | TABLE ACCESS FULL| TB_LHR_20160525_01 | 1 | 5 | 351 (2)| 00:00:05 |
20-----------------------------------------------------------------------------------------
21
22Predicate Information (identified by operation id):
23---------------------------------------------------
24
25 2 - filter("OBJECT_ID"=100)
26
27
28Statistics
29----------------------------------------------------------
30 0 recursive calls
31 0 db block gets
32 1249 consistent gets
33 0 physical reads
34 0 redo size
35 526 bytes sent via SQL*Net to client
36 520 bytes received via SQL*Net from client
37 2 SQL*Net roundtrips to/from client
38 0 sorts (memory)
39 0 sorts (disk)
40 1 rows processed
41LHR@dlhr> execute dbms_sqltune.accept_sql_profile(task_name =>'sql_profile_test_SQLID', task_owner => 'LHR', replace => TRUE);
42
43PL/SQL procedure successfully completed.
44
45LHR@dlhr> set autot off
46LHR@dlhr> SELECT e.task_name, b.name, d.sql_text, extractvalue(value(h), '.') as hints
47 2 FROM dba_sql_profiles d,
48 3 dba_advisor_tasks e,
49 4 SYS.SQLOBJ$DATA A,
50 5 SYS.SQLOBJ$ B,
51 6 TABLE(XMLSEQUENCE(EXTRACT(XMLTYPE(A.COMP_DATA),
52 7 '/outline_data/hint'))) h
53 8 where a.signature = b.signature
54 9 and a.category = b.category
55 10 and a.obj_type = b.obj_type
56 11 and a.plan_id = b.plan_id
57 12 and a.signature = d.signature
58 13 and d.task_id=e.task_id
59 14 and d.name = 'SYS_SQLPROF_0154e728ad3f0000'
60 15 ;
61
62TASK_NAME NAME
63------------------------------ ------------------------------
64SQL_TEXT
65----------------------------------------------------------------------------------------------------
66HINTS
67----------------------------------------------------------------------------------------------------
68sql_profile_test SYS_SQLPROF_0154e728ad3f0000
69select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01
70where object_id = 100
71OPTIMIZER_FEATURES_ENABLE(default)
72
73sql_profile_test SYS_SQLPROF_0154e728ad3f0000
74select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01
75where object_id = 100
76IGNORE_OPTIM_EMBEDDED_HINTS
在这里用了包DBMS_SQLTUNE的另一个函数：ACCEPT_SQL_PROFILE。其中，参数task_name即我们创建的优化建议任务的名称，name是profile的名字，可以是任意合法名称。此外这个函数还有其他一些函数，下面是这个函数的原型：
1DBMS_SQLTUNE.ACCEPT_SQL_PROFILE ( 2 task_name IN VARCHAR2, 3 object_id IN NUMBER := NULL, 4 name IN VARCHAR2 := NULL, 5 description IN VARCHAR2 := NULL, 6 category IN VARCHAR2 := NULL; 7 task_owner IN VARCHAR2 := NULL, 8 replace IN BOOLEAN := FALSE, 9 force_match IN BOOLEAN := FALSE)10 RETURN VARCHAR2;
2 task_name IN VARCHAR2,
3 object_id IN NUMBER := NULL,
4 name IN VARCHAR2 := NULL,
5 description IN VARCHAR2 := NULL,
6 category IN VARCHAR2 := NULL;
7 task_owner IN VARCHAR2 := NULL,
8 replace IN BOOLEAN := FALSE,
9 force_match IN BOOLEAN := FALSE)
10 RETURN VARCHAR2;
Description是profile的描述信息；task_owner是优化建议任务的所有者；replace为TRUE时，如果这个profile已经存在，就代替它；force_match为TURE时，表示与语句强制匹配，即强制使用绑定变量，和系统参数cursor_sharing设置为FORCE时类似，为FALSE时，与cursor_sharing设置为EXACT时类似，即完全匹配。
这里要特别提到的是category这个参数，你可以通过设置这个参数，制定特定会话使用这个profile。在10g中，每个会话都有一个新参数SQLTUNE_CATEGORY，他的默认值是DEFAULT。而我们在调用这个函数时，如果没有指定这个参数，那它的值也是DEFAULT，而如果我们给这个profile指定了一个其它的CATEGORY值，如FOR_TUNING，那么只有会话参SQLTUNE_CATEGORY也为FOR_TUNING时，才会使用这个porfile。为什么说这个参数很有用呢？试想一个这样的环境：你在一个生产系统上利用STA调优一条语句，STA已经给出了优化建议，但是你又不敢贸然实施它给出的建议（毕竟它只是机器嘛，不能完全信任），你就可以创建一个有特殊CATEGORY的profile，然后在你自己的会话中制定SQLTUNE_CATEGORY为这个特殊的CATEGORY，那就既可以看优化建议的实际效果又不影响生产环境。
此外可以通过视图DBA_SQL_PROFILES来查看已经创建的profile。
第五步：查看profile的效果
1LHR@dlhr> set autot on 2LHR@dlhr> select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100 ; 3 4 COUNT(*) 5---------- 6 1 7 8 9Execution Plan10----------------------------------------------------------11Plan hash value: 6615158791213--------------------------------------------------------------------------------------------14| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |15--------------------------------------------------------------------------------------------16| 0 | SELECT STATEMENT | | 1 | 5 | 1 (0)| 00:00:01 |17| 1 | SORT AGGREGATE | | 1 | 5 | | |18|* 2 | INDEX RANGE SCAN| TB_LHR_20160525_01_IDX | 1 | 5 | 1 (0)| 00:00:01 |19--------------------------------------------------------------------------------------------2021Predicate Information (identified by operation id):22---------------------------------------------------2324 2 - access("OBJECT_ID"=100)2526Note27-----28 - SQL profile "SYS_SQLPROF_0154e728ad3f0000" used for this statement293031Statistics32----------------------------------------------------------33 1 recursive calls34 0 db block gets35 2 consistent gets36 0 physical reads37 0 redo size38 526 bytes sent via SQL*Net to client39 520 bytes received via SQL*Net from client40 2 SQL*Net roundtrips to/from client41 0 sorts (memory)42 0 sorts (disk)43 1 rows processedset autot on
2LHR@dlhr> select /*+no_index(TB_LHR_20160525_01 TB_LHR_20160525_01_idx)*/count(*) from lhr.TB_LHR_20160525_01 where object_id = 100 ;
3
4 COUNT(*)
5----------
6 1
7
8
9Execution Plan
10----------------------------------------------------------
11Plan hash value: 661515879
12
13--------------------------------------------------------------------------------------------
14| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
15--------------------------------------------------------------------------------------------
16| 0 | SELECT STATEMENT | | 1 | 5 | 1 (0)| 00:00:01 |
17| 1 | SORT AGGREGATE | | 1 | 5 | | |
18|* 2 | INDEX RANGE SCAN| TB_LHR_20160525_01_IDX | 1 | 5 | 1 (0)| 00:00:01 |
19--------------------------------------------------------------------------------------------
20
21Predicate Information (identified by operation id):
22---------------------------------------------------
23
24 2 - access("OBJECT_ID"=100)
25
26Note
27-----
28 - SQL profile "SYS_SQLPROF_0154e728ad3f0000" used for this statement
29
30
31Statistics
32----------------------------------------------------------
33 1 recursive calls
34 0 db block gets
35 2 consistent gets
36 0 physical reads
37 0 redo size
38 526 bytes sent via SQL*Net to client
39 520 bytes received via SQL*Net from client
40 2 SQL*Net roundtrips to/from client
41 0 sorts (memory)
42 0 sorts (disk)
43 1 rows processed
从NOTE部分可以看到，语句采用了profile中的数据，创建了新的查询计划。并且在查询计划中还有一些附加信息，表明这个语句是采用了“SYS_SQLPROF_0154e728ad3f0000”这个Profile，而不是根据对象上面的统计数据来生成的查询计划。
但上述方法主要是依赖sql tuning advisor,如果它无法生成你想要的执行计划.你还可以通过手动的方式,通过sql profile把hint加进去.复杂的SQL的hint可以采用脚本coe_xfr_sql_profile.sql来产生原语句的outline data和加hint语句的outline data，然后替换对应的SYS.SQLPROF_ATTR，最后执行生成的sql就可以了。
使用PLSQL DEVELOPER 11查看执行计划，如下图，新版本的好处：
本文选自《Oracle程序员面试笔试宝典》，作者：李华荣。
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