Oracle ---- 固定执行计划之SqlProfile
Posted Scott
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Oracle ---- 固定执行计划之SqlProfile相关的知识,希望对你有一定的参考价值。
今天给大家讲一下另外一种固定执行计划的方法:SqlProfile。
1.取得不加Hint的执行计划。
SQL> conn test/test
接続されました。
SQL> explain plan for select * from tab2 where c2=2;
解析されました。
SQL> select * from table (dbms_xplan.display(format=>\'advanced\'));
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------
Plan hash value: 2156729920
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 50 | 450 | 5 (0)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| TAB2 | 50 | 450 | 5 (0)| 00:00:01 |
--------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1 / TAB2@SEL$1
Outline Data
-------------
/*+
BEGIN_OUTLINE_DATA
FULL(@"SEL$1" "TAB2"@"SEL$1")
OUTLINE_LEAF(@"SEL$1")
ALL_ROWS
DB_VERSION(\'11.2.0.4\')
OPTIMIZER_FEATURES_ENABLE(\'11.2.0.4\')
IGNORE_OPTIM_EMBEDDED_HINTS
END_OUTLINE_DATA
*/
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("C2"=2)
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - "TAB2"."C1"[NUMBER,22], "C2"[NUMBER,22], "TAB2"."C3"[VARCHAR2,10]
37行が選択されました。
2.取得加Hint的执行计划。
SQL> explain plan for select /*+ index(tab2 ind2_2) */ * from tab2 where c2=2;
解析されました。
SQL> select * from table (dbms_xplan.display(format=>\'advanced\'));
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------
Plan hash value: 3201770281
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 50 | 450 | 11 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| TAB2 | 50 | 450 | 11 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IND2_2 | 50 | | 1 (0)| 00:00:01 |
--------------------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1 / TAB2@SEL$1
2 - SEL$1 / TAB2@SEL$1
Outline Data
-------------
/*+
BEGIN_OUTLINE_DATA
INDEX_RS_ASC(@"SEL$1" "TAB2"@"SEL$1" ("TAB2"."C2"))
OUTLINE_LEAF(@"SEL$1")
ALL_ROWS
DB_VERSION(\'11.2.0.4\')
OPTIMIZER_FEATURES_ENABLE(\'11.2.0.4\')
IGNORE_OPTIM_EMBEDDED_HINTS
END_OUTLINE_DATA
*/
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("C2"=2)
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - "TAB2"."C1"[NUMBER,22], "C2"[NUMBER,22], "TAB2"."C3"[VARCHAR2,10]
2 - "TAB2".ROWID[ROWID,10], "C2"[NUMBER,22]
40行が選択されました。
3.把加Hint的执行计划做成SqlProfile,固定给不加Hint的SQL文。
SQL> conn / as sysdba
接続されました。
SQL> DECLARE
2 sql_stmt clob;
3 BEGIN
4 sql_stmt:=q\'^select * from tab2 where c2=2^\';
5 dbms_sqltune.import_sql_profile(
6 sql_text => sql_stmt,
7 name=>\'test profile\',
8 profile => sqlprof_attr(q\'^INDEX_RS_ASC(@"SEL$1" "TAB2"@"SEL$1" ("TAB2"."C2"))^\',
9 q\'^OUTLINE_LEAF(@"SEL$1")^\',
10 q\'^ALL_ROWS^\',
11 q\'^DB_VERSION(\'11.2.0.4\')^\',
12 q\'^OPTIMIZER_FEATURES_ENABLE(\'11.2.0.4\')^\',
13 q\'^IGNORE_OPTIM_EMBEDDED_HINTS^\'),
14 force_match=>true);
15 end;
16/
PL/SQLプロシージャが正常に完了しました。
4.看看结果。
SQL> conn test/test
接続されました。
SQL> set autot traceonly exp
SQL> set lin 120 pages 999
SQL> select * from tab2 where c2=2;
実行計画
----------------------------------------------------------
Plan hash value: 3201770281
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 50 | 450 | 11 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| TAB2 | 50 | 450 | 11 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IND2_2 | 50 | | 1 (0)| 00:00:01 |
--------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("C2"=2)
Note
-----
- SQL profile "test profile" used for this statement
以上是关于Oracle ---- 固定执行计划之SqlProfile的主要内容,如果未能解决你的问题,请参考以下文章