Oracle利用coe_load_sql_profile脚本绑定执行计划

coe_load_sql_profile_v2.sql脚本利用的是profile原理,只是做了半自动的形式来使用,下面是测试过程。

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Oracle利用coe_load_sql_profile脚本绑定执行计划 coe_load_sql_profile_v2.txt

创建环境,构建测试表:

SQL> create table t1 as select * from dba_objects where object_id is not null;


Table created.


SQL> alter table t1 modify object_id not null;


Table altered.


SQL> create index idx_t1_obj_id on t1(object_id);


Index created.


索引不存储null值


SQL> analyze table t1 compute statistics;


Table analyzed.


SQL> select count(*) from t1;


  COUNT(*)

----------

     87070


SQL> select * from table(dbms_xplan.display_cursor(null,0));


PLAN_TABLE_OUTPUT

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

SQL_ID 12c0v4my7dvr3, child number 0

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

select count(*) from t1


Plan hash value: 1657298618


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

| Id  | Operation             | Name | Rows  | Cost (%CPU)| Time    |

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

|   0 | SELECT STATEMENT  |      |      |      54 (100)|      |

|   1 |  SORT AGGREGAT    |      |     1 |       |      |


PLAN_TABLE_OUTPUT

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

|   2 |   INDEX FAST FULL SCAN| IDX_T1_OBJ_ID | 87070 |    54 (0)| 00:00:01 |

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



14 rows selected.

会发现是进行的索引快速扫描。


使用hint提示,强行走全表扫描,然后生成执行计划。

SQL> select /*+ full(t1) */ count(*)from t1;


  COUNT(*)

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

     87070


SQL> select * from table(dbms_xplan.display_cursor(null,0));


PLAN_TABLE_OUTPUT

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

SQL_ID 20pat9zfypprh, child number 0

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

select /*+ full(t1) */ count(*)from t1


Plan hash value: 3724264953


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

| Id  | Operation              | Name | Rows | Cost (%CPU)| Time   |

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

|   0 | SELECT STATEMENT   |  |  |    347 (100)|    |

|   1 |  SORT AGGREGATE    |  | 1|          |    |


PLAN_TABLE_OUTPUT

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

|   2 |   TABLE ACCESS FULL| T1   | 87070 |   347   (1)| 00:00:05 |

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



14 rows selected.


SQL> @coe_load_sql_profile_v2.sql


Parameter 1:

SQL_ID (required)


Enter value for 1: 12c0v4my7dvr3



PLAN_HASH_VALUE AVG_ET_SECS

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

     1657298618        .141


Parameter 2:

PLAN_HASH_VALUE (required)


Enter value for 2: 3724264953


Values passed to coe_xfr_sql_profile:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SQL_ID       : "12c0v4my7dvr3"

PLAN_HASH_VALUE: "3724264953"


SQL>BEGIN

  2   IF :sql_text IS NULL THEN

  3    RAISE_APPLICATION_ERROR(-20100, 'SQL_TEXT for SQL_ID &&sql_id. was not found in memory (gv$sqltext_with_newlines) or AWR (dba_hist_sqltext).');

  4   END IF;

  5  END;

  6  /

SQL>SET TERM OFF;

SQL>BEGIN

  2   IF :other_xml IS NULL THEN

  3    RAISE_APPLICATION_ERROR(-20101, 'PLAN for SQL_ID &&sql_id. and PHV &&plan_hash_value. was not found in memory (gv$sql_plan) or AWR (dba_hist_sql_plan).');

  4   END IF;

  5  END;

  6  /

SQL>SET TERM OFF;


Execute coe_xfr_sql_profile_12c0v4my7dvr3_3724264953.sql

on TARGET system in order to create a custom SQL Profile

with plan 3724264953 linked to adjusted sql_text.

.........省略


COE_XFR_SQL_PROFILE_12c0v4my7dvr3_3724264953 completed


COE_XFR_SQL_PROFILE completed.

SQL>explain plan for select count(*) from t1;


Explained.


SQL>select * from table(dbms_xplan.display());


PLAN_TABLE_OUTPUT

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

Plan hash value: 3724264953


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

| Id  | Operation   | Name | Rows  | Cost (%CPU)| Time  |

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

|   0 | SELECT STATEMENT   |  | 1 |   347   (1)| 00:00:05 |

|   1 |  SORT AGGREGATE    |  | 1 |       |  |

|   2 |   TABLE ACCESS FULL| T1   | 87070 |   347   (1)| 00:00:05 |

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


Note


PLAN_TABLE_OUTPUT

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

-----

   - SQL profile "coe_12c0v4my7dvr3_3724264953" used for this statement


13 rows selected.


SQL> select name,category,status,sql_text from dba_sql_profiles;


NAME           CATEGORY   STATUS    SQL_TEXT

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

coe_12c0v4my7dvr3_3724264953   DEFAULT  ENABLED  select count(*) from t1


可以看到脚本coe_load_sql_profile_v2.sql将执行计划固定了。



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