oracle spm使用1
阿新 • • 發佈：2017-05-15
ads info autotrac state sort table cli plan oracle11
oracle11g new feature SPM
有助於保持sql的語句特性，僅僅同意運行性能提高的運行計劃。
它不同於stored outlines， spm在於穩定sql性能，而store outlines在於凍結sql運行計劃
事列
1.啟用optimizer_cature_sql_plan_baselines 捕獲sql語句
SQL> alter session set optimizer_capture_sql_plan_baselines = true;
Session altered.
SQL> select * from objs where object_id = 2;
no rows selected
SQL> select * from objs where object_id = 2;
no rows selected
SQL> alter session set optimizer_capture_sql_plan_baselines = false;
Session altered.
2.查詢dba_sql_plan_baselines，確定sql的spm狀態
SQL> select plan_name, sql_handle, enabled, accepted, fixed,
2 module, sql_text
3 from dba_sql_plan_baselines;
PLAN_NAME SQL_HANDLE ENABLED ACCEPTED FIXED MODULE SQL_TEXT
------------------------------ -------------------- --------- --------- --------- -------------------- --------------------------------------------------
SQL_PLAN_4pzq3z6xcqkpwd0984253 SQL_4afec3f9bacb4abc YES YES NO SQL*Plus select * from objs where object_id = 2
3.添加索引改變環境再執行sql
SQL> alter session set optimizer_capture_sql_plan_baselines = true;
Session altered.
SQL> select * from objs where object_id = 2;
no rows selected
SQL> select * from objs where object_id = 2;
no rows selected
SQL> alter session set optimizer_capture_sql_plan_baselines = false;
Session altered.
4.查詢dba_sql_plan_baselines
SQL> select plan_name, sql_handle, enabled, accepted, fixed, module, sql_text from dba_sql_plan_baselines;
PLAN_NAME SQL_HANDLE ENABLED ACCEPTED FIXED MODULE SQL_TEXT
------------------------------ -------------------- --------- --------- --------- -------------------- --------------------------------------------------
SQL_PLAN_4pzq3z6xcqkpwbe4c314c SQL_4afec3f9bacb4abc YES NO NO SQL*Plus select * from objs where object_id = 2
SQL_PLAN_4pzq3z6xcqkpwd0984253 SQL_4afec3f9bacb4abc YES YES NO SQL*Plus select * from objs where object_id = 2
SQL>
5.測試
SQL>
SQL> set autotrace on
SQL> select * from objs where object_id = 2;
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 954894094
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 98 | 247 (1)| 00:00:03 |
|* 1 | TABLE ACCESS FULL| OBJS | 1 | 98 | 247 (1)| 00:00:03 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("OBJECT_ID"=2)
Note
-----
- SQL plan baseline "SQL_PLAN_4pzq3z6xcqkpwd0984253" used for this statement
Statistics
----------------------------------------------------------
255 recursive calls
0 db block gets
1044 consistent gets
879 physical reads
0 redo size
1343 bytes sent via SQL*Net to client
513 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
28 sorts (memory)
0 sorts (disk)
0 rows processed
SQL> alter session set optimizer_use_sql_plan_baselines = false;
Session altered.
SQL> select * from objs where object_id = 2;
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 613004408
-----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 98 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| OBJS | 1 | 98 | 2 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IDX_OBJSID_OBJS | 1 | | 1 (0)| 00:00:01 |
-----------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("OBJECT_ID"=2)
Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
2 consistent gets
4 physical reads
0 redo size
1343 bytes sent via SQL*Net to client
513 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rows processed
有助於保持sql的語句特性，僅僅同意運行性能提高的運行計劃。
它不同於stored outlines， spm在於穩定sql性能，而store outlines在於凍結sql運行計劃
事列
1.啟用optimizer_cature_sql_plan_baselines 捕獲sql語句
SQL> alter session set optimizer_capture_sql_plan_baselines = true;
Session altered.
SQL> select * from objs where object_id = 2;
no rows selected
SQL> select * from objs where object_id = 2;
no rows selected
SQL> alter session set optimizer_capture_sql_plan_baselines = false;
Session altered.
2.查詢dba_sql_plan_baselines，確定sql的spm狀態
SQL> select plan_name, sql_handle, enabled, accepted, fixed,
2 module, sql_text
3 from dba_sql_plan_baselines;
PLAN_NAME SQL_HANDLE ENABLED ACCEPTED FIXED MODULE SQL_TEXT
------------------------------ -------------------- --------- --------- --------- -------------------- --------------------------------------------------
SQL_PLAN_4pzq3z6xcqkpwd0984253 SQL_4afec3f9bacb4abc YES YES NO SQL*Plus select * from objs where object_id = 2
3.添加索引改變環境再執行sql
SQL> alter session set optimizer_capture_sql_plan_baselines = true;
Session altered.
SQL> select * from objs where object_id = 2;
no rows selected
SQL> select * from objs where object_id = 2;
no rows selected
SQL> alter session set optimizer_capture_sql_plan_baselines = false;
Session altered.
4.查詢dba_sql_plan_baselines
SQL> select plan_name, sql_handle, enabled, accepted, fixed, module, sql_text from dba_sql_plan_baselines;
PLAN_NAME SQL_HANDLE ENABLED ACCEPTED FIXED MODULE SQL_TEXT
------------------------------ -------------------- --------- --------- --------- -------------------- --------------------------------------------------
SQL_PLAN_4pzq3z6xcqkpwbe4c314c SQL_4afec3f9bacb4abc YES NO NO SQL*Plus select * from objs where object_id = 2
SQL_PLAN_4pzq3z6xcqkpwd0984253 SQL_4afec3f9bacb4abc YES YES NO SQL*Plus select * from objs where object_id = 2
SQL>
5.測試
SQL>
SQL> set autotrace on
SQL> select * from objs where object_id = 2;
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 954894094
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 98 | 247 (1)| 00:00:03 |
|* 1 | TABLE ACCESS FULL| OBJS | 1 | 98 | 247 (1)| 00:00:03 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("OBJECT_ID"=2)
Note
-----
- SQL plan baseline "SQL_PLAN_4pzq3z6xcqkpwd0984253" used for this statement
Statistics
----------------------------------------------------------
255 recursive calls
0 db block gets
1044 consistent gets
879 physical reads
0 redo size
1343 bytes sent via SQL*Net to client
513 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
28 sorts (memory)
0 sorts (disk)
0 rows processed
SQL> alter session set optimizer_use_sql_plan_baselines = false;
Session altered.
SQL> select * from objs where object_id = 2;
no rows selected
Execution Plan
----------------------------------------------------------
Plan hash value: 613004408
-----------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-----------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 98 | 2 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| OBJS | 1 | 98 | 2 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IDX_OBJSID_OBJS | 1 | | 1 (0)| 00:00:01 |
-----------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("OBJECT_ID"=2)
Statistics
----------------------------------------------------------
1 recursive calls
0 db block gets
2 consistent gets
4 physical reads
0 redo size
1343 bytes sent via SQL*Net to client
513 bytes received via SQL*Net from client
1 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
0 rows processed
能夠看到當啟動optimizer_user_sql_plan_baselines時走索引應該是最優的卻沒有使用
plan_name accecpt 為 no 影響了走索引計劃
oracle spm使用1