1. 引子
Oracle系統(tǒng)為了合理分配和使用系統(tǒng)的資源提出了概要文件的概念。所謂概要文件，就是一份描述如何使用系統(tǒng)的資源(主要是CPU資源)的配置文件。將概要文件賦予某個數(shù)據(jù)庫用戶，在用戶連接并訪問數(shù)據(jù)庫服務器時，系統(tǒng)就按照概要文件給他分配資源。
包括:
1、管理數(shù)據(jù)庫系統(tǒng)資源。
利用Profile來分配資源限額，必須把初始化參數(shù)resource_limit設置為true默認是TRUE的。
2、管理數(shù)據(jù)庫口令及驗證方式。
默認給用戶分配的是DEFAULT概要文件，將該文件賦予了每個創(chuàng)建的用戶。但該文件對資源沒有任何限制，因此管理員常常需要根據(jù)自己數(shù)據(jù)庫系統(tǒng)的環(huán)境自行建立概要文件。
2. 概要文件限制
概要文件主要可以對數(shù)據(jù)庫系統(tǒng)如下指標進行限制。
1）用戶的最大并發(fā)會話數(shù)（SESSION_PER_USER)
2）每個會話的CPU時鐘限制（CPU_PER_SESSION）
3）每次調用的CPU時鐘限制，調用包含解析、執(zhí)行命令和獲取數(shù)據(jù)等等。（CPU_PER_CALL）
4）最長連接時間。一個會話的連接時間超過指定時間之后，Oracle會自動的斷開連接（CONNECT_TIME）
5）最長空閑時間。如果一個會話處于空閑狀態(tài)超過指定時間，Oracle會自動斷開連接（IDLE_TIME）
6）每個會話可以讀取的最大數(shù)據(jù)塊數(shù)量（LOGICAL_READS_PER_SESSION）
7）每次調用可以讀取的最大數(shù)據(jù)塊數(shù)量（LOGICAL_READS_PER_CALL）
8）SGA私有區(qū)域的最大容量（PRIVATE_SGA）
概要文件對口令的定義和限制如下：
1）登錄失敗的最大嘗試次數(shù)（FAILED_LOGIN_ATTEMPTS）
2）口令的最長有效期(PASSWORD_LIFE_TIME)
3）口令在可以重用之前必須修改的次數(shù)(PASSWORD_REUSE_MAX)
4）口令在可以重用之前必須經(jīng)過的天數(shù)(PASSWORD_REUSE_TIME)
5）超過登錄失敗的最大允許嘗試次數(shù)后，賬戶被鎖定的天數(shù)
6）指定用于判斷口令復雜度的函數(shù)名
在指定概要文件之后，DBA可以手工的將概要文件賦予每個用戶。但是概要文件不是立即生效，而是要將初始化參數(shù)文件中的參數(shù)RESOURCE_LIMIT設置為TRUE之后，概要文件才會生效。
3. SQL PROFILE
SQL PROFILE在ORACLE10g中引入，主要目的側重于SQL優(yōu)化，彌補了存儲概要的缺點.
DBA可以使用SQL調整顧問(STA)或SQL訪問顧問(SAA)來識別可以得到更好性能的SQL語句，
這些語句可以保存在SQL調整集、一個AWR快照或保存在當前的庫緩存中，一旦識別出調整候選者， 這些顧問程序就開始分析捕獲到的語句以期獲得更好的性能，然后生成專用的語句擴展(就叫做SQL配置文件)并重寫SQL語句以在執(zhí)行期間獲取更佳的性能。
與存儲概要類似，一個SQL配置文件提供了使用更好的執(zhí)行計劃的能力(如果這個執(zhí)行計
劃是可用的)，SQL配置文件也可以象存儲概要一樣分階段執(zhí)行，或限制到對特定會話才能執(zhí)行該SQL配置文件，但是大多數(shù)重要的改進超過了存儲概要.
SQLProfile對于一下類型語句有效：
SELECT語句；
UPDATE語句；
INSERT語句（僅當使用SELECT子句時有效）；
DELETE語句；
CREATE語句（僅當使用SELECT子句時有效）；
MERGE語句（僅當作UPDATE和INSERT操作時有效）。
另外，使用SQL Profile還必須有CREATE ANY SQL PROFILE、DROP ANY SQL PROFILE和ALTER ANY SQL PROFILE等系統(tǒng)權限。
4. 測試一
創(chuàng)建表
tpcc@TOADDB> create table t1 as selectobject_id,object_name from dba_objects where rownum=50000;
Table created.
tpcc@TOADDB> create table t2 as select * fromdba_objects;
Table created.
創(chuàng)建索引：
tpcc@TOADDB> create index t2_idx on t2(object_id);
Index created.
收集統(tǒng)計信息：
tpcc@TOADDB> execdbms_stats.gather_table_stats(user,'t1',cascade=>true,method_opt=>'forall columns size 1');
PL/SQL procedure successfully completed.
tpcc@TOADDB> execdbms_stats.gather_table_stats(user,'t1',cascade=>true,method_opt=>'forall columns size 1');
PL/SQL procedure successfully completed.
執(zhí)行無HINT的SQL
tpcc@TOADDB> set autotrace on
tpcc@TOADDB> select t1.*,t2.owner from t1,t2 wheret1.object_name like '%T1%' and t1.object_id=t2.object_id;
42 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 1838229974
---------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
---------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 2500 | 97K| 498 (1)| 00:00:01 |
|* 1| HASH JOIN | | 2500 | 97K| 498 (1)| 00:00:01 |
|* 2| TABLE ACCESS FULL| T1 | 2500 | 72500 | 68 (0)| 00:00:01 |
| 3| TABLE ACCESS FULL| T2 | 92021 | 988K| 430 (1)| 00:00:01 |
---------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
1-access("T1"."OBJECT_ID"="T2"."OBJECT_ID")
2- filter("T1"."OBJECT_NAME" LIKE '%T1%' AND"T1"."OBJECT_NAME" IS
NOT NULL)
Statistics
----------------------------------------------------------
1 recursive calls
0 dbblock gets
1789 consistent gets
0 physical reads
0 redosize
2350 bytes sent via SQL*Net toclient
573 bytes received via SQL*Net from client
4 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
42 rowsprocessed
執(zhí)行帶Hint的SQL
SQL>select /*+ use_nl(t1 t2) index(t2)*/ t1.*,t2.owner from t1,t2 where t1.object_name like '%T1%' and t1.object_id=t2.object_id;
42 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 1022743391
---------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
---------------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 2500 | 97K| 5069 (1)|00:00:01 |
| 1| NESTED LOOPS | | 2500| 97K| 5069 (1)| 00:00:01 |
| 2| NESTED LOOPS | | 2500 | 97K| 5069 (1)| 00:00:01 |
|* 3| TABLE ACCESS FULL | T1 | 2500 | 72500 | 68 (0)|00:00:01 |
|* 4| INDEX RANGE SCAN |T2_IDX | 1 | | 1 (0)| 00:00:01 |
| 5| TABLE ACCESS BY INDEX ROWID| T2 | 1 | 11 | 2 (0)|00:00:01 |
---------------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
3- filter("T1"."OBJECT_NAME" LIKE '%T1%' AND"T1"."OBJECT_NAME" IS NOT
NULL)
4-access("T1"."OBJECT_ID"="T2"."OBJECT_ID")
Statistics
----------------------------------------------------------
1 recursive calls
0 dbblock gets
304 consistent gets
24 physical reads
0 redosize
2350 bytes sent via SQL*Net toclient
573 bytes received via SQL*Net from client
4 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
42 rowsprocessed
使用SQL PROFILE
查找執(zhí)行SQL的SQL_ID
tpcc@TOADDB> select sql_id,sql_text from v$sqlwhere sql_text like '%t1.object_name%';
SQL_ID
-------------
SQL_TEXT
----------------------------------------------------------------------------------------------------
4zbqykx89yc8v
select t1.*,t2.owner from t1,t2 wheret1.object_name like '%T1%' and t1.object_id=t2.object_id
18bphz37dajq9
select /*+ use_nl(t1 t2) index(t2) */t1.*,t2.owner from t1,t2 where t1.object_name like '%T1%' and
t1.object_id=t2.object_id
運行存儲過程如下：
var tuning_task varchar2(100);
DECLARE
l_sql_id v$session.prev_sql_id%TYPE;
l_tuning_task VARCHAR2(30);
BEGIN
l_sql_id:='4zbqykx89yc8v';
l_tuning_task := dbms_sqltune.create_tuning_task(sql_id =>l_sql_id);
:tuning_task:=l_tuning_task;
dbms_sqltune.execute_tuning_task(l_tuning_task);
dbms_output.put_line(l_tuning_task);
END;
/
TASK_114
PL/SQL procedure successfully completed.
查看task的名字
tpcc@TOADDB> print tuning_task;
TUNING_TASK
----------------------------------------------------------------------------------------------------
TASK_114
查看執(zhí)行報告
set long 99999
col comments format a200
SELECT dbms_sqltune.report_tuning_task(:tuning_task)COMMENTS FROM dual;
COMMENTS
----------------------------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name : TASK_114
Tuning Task Owner : TPCC
Workload Type : Single SQL Statement
Scope : COMPREHENSIVE
Time Limit(seconds): 1800
Completion Status : COMPLETED
Started at : 03/06/2016 05:27:21
Completed at : 03/06/2016 05:27:24
-------------------------------------------------------------------------------
Schema Name: TPCC
SQL ID : 4zbqykx89yc8v
SQL Text : select t1.*,t2.owner from t1,t2 where t1.object_name like '%T1%'
and t1.object_id=t2.object_id
-------------------------------------------------------------------------------
FINDINGS SECTION (1 finding)
-------------------------------------------------------------------------------
1- SQL Profile Finding (see explain planssection below)
--------------------------------------------------------
Apotentially better execution plan was found for this statement.
Recommendation (estimated benefit: 83.08%)
------------------------------------------
-Consider accepting the recommended SQL profile.
executedbms_sqltune.accept_sql_profile(task_name => 'TASK_114',
task_owner =>'TPCC', replace => TRUE);
Validation results
------------------
TheSQL profile was tested by executing both its plan and the original plan
andmeasuring their respective execution statistics. A plan may have been
only partially executed if the other could be run to completion in lesstime.
Original Plan With SQL Profile % Improved
------------- ---------------- ----------
Completion Status: COMPLETE COMPLETE
Elapsed Time (s): .012865 .004556 64.58 %
CPUTime (s): .0124 .0045 63.7%
User I/O Time (s): 0 0
Buffer Gets: 1787 302 83.1%
Physical Read Requests: 0 0
Physical Write Requests: 0 0
Physical Read Bytes: 0 0
Physical Write Bytes: 0 0
Rows Processed: 42 42
Fetches: 42 42
Executions: 1 1
Notes
-----
1.Statistics for the original plan were averaged over 10 executions.
2.Statistics for the SQL profile plan were averaged over 10 executions.
-------------------------------------------------------------------------------
EXPLAIN PLANS SECTION
-------------------------------------------------------------------------------
1- Original With Adjusted Cost
------------------------------
Plan hash value: 1838229974
---------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
---------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 42 | 1680 | 498 (1)| 00:00:01 |
|* 1| HASH JOIN | | 42 | 1680 | 498 (1)| 00:00:01 |
|* 2| TABLE ACCESS FULL| T1 | 42 | 1218 | 68 (0)| 00:00:01 |
| 3| TABLE ACCESS FULL| T2 | 92021 | 988K| 430 (1)| 00:00:01 |
---------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
1-access("T1"."OBJECT_ID"="T2"."OBJECT_ID")
2- filter("T1"."OBJECT_NAME" LIKE '%T1%' AND"T1"."OBJECT_NAME" IS
NOT NULL)
2- Using SQL Profile
--------------------
Plan hash value: 1022743391
---------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
---------------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 42 | 1680 | 152 (0)|00:00:01 |
| 1| NESTED LOOPS | | 42 | 1680 | 152 (0)| 00:00:01 |
| 2| NESTED LOOPS | | 42 | 1680 | 152 (0)| 00:00:01 |
|* 3| TABLE ACCESS FULL | T1 | 42 | 1218 | 68 (0)| 00:00:01 |
|* 4| INDEX RANGE SCAN |T2_IDX | 1 | | 1 (0)| 00:00:01 |
| 5| TABLE ACCESS BY INDEX ROWID| T2 | 1 | 11 | 2 (0)|00:00:01 |
---------------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
3- filter("T1"."OBJECT_NAME" LIKE '%T1%' AND"T1"."OBJECT_NAME" IS NOT
NULL)
4-access("T1"."OBJECT_ID"="T2"."OBJECT_ID")
-------------------------------------------------------------------------------
接受分析建議
報告中給出了執(zhí)行方法，如上紅色部分
接受報告的建議，驗證一下如下：
tpcc@TOADDB> execute dbms_sqltune.accept_sql_profile(task_name=> 'TASK_114',task_owner => 'TPCC', replace => TRUE);
PL/SQL procedure successfully completed.
執(zhí)行測試
再執(zhí)行原先命令如下：
tpcc@TOADDB> select t1.*,t2.owner from t1,t2 wheret1.object_name like '%T1%' and t1.object_id=t2.object_id;
42 rows selected.
Execution Plan
----------------------------------------------------------
Plan hash value: 1022743391
---------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|Time |
---------------------------------------------------------------------------------------
| 0| SELECT STATEMENT | | 42 | 1680 | 152 (0)|00:00:01 |
| 1| NESTED LOOPS | | 42| 1680 | 152 (0)|00:00:01 |
| 2| NESTED LOOPS | | 42 | 1680 | 152 (0)| 00:00:01 |
|* 3| TABLE ACCESS FULL | T1 | 42 | 1218 | 68 (0)| 00:00:01 |
|* 4| INDEX RANGE SCAN |T2_IDX | 1 | | 1 (0)| 00:00:01 |
| 5| TABLE ACCESS BY INDEX ROWID| T2 | 1 | 11 | 2 (0)|00:00:01 |
---------------------------------------------------------------------------------------
Predicate Information (identified byoperation id):
---------------------------------------------------
3- filter("T1"."OBJECT_NAME" LIKE '%T1%' AND"T1"."OBJECT_NAME" IS NOT
NULL)
4-access("T1"."OBJECT_ID"="T2"."OBJECT_ID")
Note
-----
- SQL profile"SYS_SQLPROF_01534b8309b90000" used for this statement
- this is an adaptive plan
Statistics
----------------------------------------------------------
35 recursive calls
0 dbblock gets
317 consistent gets
1 physical reads
0 redosize
2350 bytes sent via SQL*Net toclient
573 bytes received via SQL*Net from client
4 SQL*Net roundtrips to/from client
1 sorts (memory)
0 sorts (disk)
42 rowsprocessed
啟用了PROFILE，PS：如果執(zhí)行中多加幾個空格，并不會影響PROFILE的生效的。
5. 維護操作
禁用命令
如下：
begin
dbms_sqltune.alter_sql_profile(
name => 'SYS_SQLPROF_01534b8309b90000',
attribute_name => 'status',
value => 'disabled');
end;
/
啟用命令
如下：
begin
dbms_sqltune.alter_sql_profile(
name => 'SYS_SQLPROF_01534b8309b90000',
attribute_name => 'status',
value => 'enabled');
end;
/
查看使用的PROFILE
如下：
SQL>SELECT task_name,status FROMUSER_ADVISOR_TASKS ;
刪除PROFILE
BEGIN
DBMS_SQLTUNE.DROP_SQL_PROFILE(name => 'SYS_SQLPROF_01534b8309b90000');
END;
總結
以上所述是小編給大家介紹的Oracle固定執(zhí)行計劃之SQL PROFILE概要文件 ，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對腳本之家網(wǎng)站的支持！
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