SQL> select * from v$version;BANNER
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Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for 64-bit Windows: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
--创建测试表
SQL> create table test_sql_tuning(id_ number);Table created.SQL> declare2  begin3    for i in 1..100000 loop4      insert into test_sql_tuning values(i)5    end loop;6    commit;7  end;8  /PL/SQL procedure successfully completed.SQL> set autotrace on exp
SQL> select * from test_sql_tuning t where t.id_=333;ID_
----------333Execution Plan
----------------------------------------------------------
Plan hash value: 3855182387-------------------------------------------------------------------------------------
| Id  | Operation         | Name            | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |                 |     3 |    39 |    69   (2)| 00:00:01 |
|*  1 |  TABLE ACCESS FULL| TEST_SQL_TUNING |     3 |    39 |    69   (2)| 00:00:01 |
-------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------1 - filter("T"."ID_"=333)Note
------ dynamic sampling used for this statement (level=2)SQL> declare2  my_task_name varchar2(50);3  begin4    my_task_name := dbms_sqltune.create_tuning_task(5    SQL_ID => 'g72kdvcacxvtf',6    scope => 'COMPREHENSIVE',7    task_name => 'ZEN_TEST_SQLTUNE');8    DBMS_SQLTUNE.execute_tuning_task(my_task_name);9  end;10  /PL/SQL procedure successfully completed.SQL> select dbms_sqltune.report_tuning_task('ZEN_TEST_SQLTUNE') from dual;DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
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GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name   : ZEN_TEST_SQLTUNE
Tuning Task Owner  : HR
Workload Type      : Single SQL Statement
Scope              : COMPREHENSIVE
Time Limit(seconds): 1800
Completion Status  : COMPLETED
Started at         : 07/02/2017 16:31:20
Completed at       : 07/02/2017 16:31:20DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Schema Name: HR
SQL ID     : cnvs1fb15pqb4
SQL Text   : select * from test_sql_tuning t where t.id_=333-------------------------------------------------------------------------------
FINDINGS SECTION (2 findings)
-------------------------------------------------------------------------------1- Statistics Finding
---------------------

DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
--------------------------------------------------------------------------------Table "HR"."TEST_SQL_TUNING" was not analyzed.Recommendation--------------- Consider collecting optimizer statistics for this table.execute dbms_stats.gather_table_stats(ownname => 'HR', tabname =>'TEST_SQL_TUNING', estimate_percent =>DBMS_STATS.AUTO_SAMPLE_SIZE, method_opt => 'FOR ALL COLUMNS SIZEAUTO');RationaleDBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
-----------------------------------------------------------------------------------------The optimizer requires up-to-date statistics for the table in order toselect a good execution plan.2- Index Finding (see explain plans section below)
--------------------------------------------------The execution plan of this statement can be improved by creating one or moreindices.Recommendation (estimated benefit: 98.55%)------------------------------------------

DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
--------------------------------------------------------------------------------- Consider running the Access Advisor to improve the physical schema designor creating the recommended index.create index HR.IDX$$_06650001 on HR.TEST_SQL_TUNING("ID_");Rationale---------Creating the recommended indices significantly improves the execution planof this statement. However, it might be preferable to run "Access Advisor"using a representative SQL workload as opposed to a single statement. Thiswill allow to get comprehensive index recommendations which takes intoaccount index maintenance overhead and additional space consumption.DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
---------------------------------------------------------------------------------------------------------------------------------------------------------------
EXPLAIN PLANS SECTION
-------------------------------------------------------------------------------1- Original
-----------
Plan hash value: 3855182387-------------------------------------------------------------------------------------
| Id  | Operation         | Name            | Rows  | Bytes | Cost (%CPU)| Time     |DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
--------------------------------------------------------------------------------
-------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |                 |     3 |    39 |    69   (2)| 00:00:01 ||*  1 |  TABLE ACCESS FULL| TEST_SQL_TUNING |     3 |    39 |    69   (2)| 00:00:01 |
-------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------1 - filter("T"."ID_"=333)DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
--------------------------------------------------------------------------------
2- Using New Indices
--------------------
Plan hash value: 1603088386-----------------------------------------------------------------------------------
| Id  | Operation        | Name           | Rows  | Bytes | Cost (%CPU)| Time     |
-----------------------------------------------------------------------------------
|   0 | SELECT STATEMENT |                |     1 |    13 |     1   (0)| 00:00:01 |
|*  1 |  INDEX RANGE SCAN| IDX$$_06650001 |     1 |    13 |     1   (0)| 00:00:01
|
-----------------------------------------------------------------------------------

DBMS_SQLTUNE.REPORT_TUNING_TASK('ZEN_TEST_SQLTUNE')
--------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------1 - access("T"."ID_"=333)-------------------------------------------------------------------------------1 row selected.Execution Plan
----------------------------------------------------------
Plan hash value: 1388734953-----------------------------------------------------------------
| Id  | Operation        | Name | Rows  | Cost (%CPU)| Time     |
-----------------------------------------------------------------
|   0 | SELECT STATEMENT |      |     1 |     2   (0)| 00:00:01 |
|   1 |  FAST DUAL       |      |     1 |     2   (0)| 00:00:01 |
-----------------------------------------------------------------

SQL>