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1.  引子

Oracle系统为了合理分配和使用系统的资源提出了概要文件的概念。所谓概要文件,就是一份描述如何使用系统的资源(主要是CPU资源)的配置文件。将概要文件赋予某个数据库用户,在用户连接并访问数据库服务器时,系统就按照概要文件给他分配资源。

包括:

1、管理数据库系统资源。

利用Profile来分配资源限额,必须把初始化参数resource_limit设置为true默认是TRUE的。

2、管理数据库口令及验证方式。

默认给用户分配的是DEFAULT概要文件,将该文件赋予了每个创建的用户。但该文件对资源没有任何限制,因此管理员常常需要根据自己数据库系统的环境自行建立概要文件。

2.  概要文件限制

概要文件主要可以对数据库系统如下指标进行限制。

1)用户的最大并发会话数(SESSION_PER_USER)

2)每个会话的CPU时钟限制(CPU_PER_SESSION)

3)每次调用的CPU时钟限制,调用包含解析、执行命令和获取数据等等。(CPU_PER_CALL)

4)最长连接时间。一个会话的连接时间超过指定时间之后,Oracle会自动的断开连接(CONNECT_TIME)

5)最长空闲时间。如果一个会话处于空闲状态超过指定时间,Oracle会自动断开连接(IDLE_TIME)

6)每个会话可以读取的最大数据块数量(LOGICAL_READS_PER_SESSION)

7)每次调用可以读取的最大数据块数量(LOGICAL_READS_PER_CALL)

8)SGA私有区域的最大容量(PRIVATE_SGA)

概要文件对口令的定义和限制如下:

1)登录失败的最大尝试次数(FAILED_LOGIN_ATTEMPTS)

2)口令的最长有效期(PASSWORD_LIFE_TIME)

3)口令在可以重用之前必须修改的次数(PASSWORD_REUSE_MAX)

4)口令在可以重用之前必须经过的天数(PASSWORD_REUSE_TIME)

5)超过登录失败的最大允许尝试次数后,账户被锁定的天数

6)指定用于判断口令复杂度的函数名

在指定概要文件之后,DBA可以手工的将概要文件赋予每个用户。但是概要文件不是立即生效,而是要将初始化参数文件中的参数RESOURCE_LIMIT设置为TRUE之后,概要文件才会生效。

3.  SQL PROFILE

SQL PROFILE在ORACLE10g中引入,主要目的侧重于SQL优化,弥补了存储概要的缺点.

DBA可以使用SQL调整顾问(STA)或SQL访问顾问(SAA)来识别可以得到更好性能的SQL语句, 

这些语句可以保存在SQL调整集、一个AWR快照或保存在当前的库缓存中,一旦识别出调整候选者, 这些顾问程序就开始分析捕获到的语句以期获得更好的性能,然后生成专用的语句扩展(就叫做SQL配置文件)并重写SQL语句以在执行期间获取更佳的性能。

  与存储概要类似,一个SQL配置文件提供了使用更好的执行计划的能力(如果这个执行计

划是可用的),SQL配置文件也可以象存储概要一样分阶段执行,或限制到对特定会话才能执行该SQL配置文件,但是大多数重要的改进超过了存储概要.

 SQLProfile对于一下类型语句有效:

    SELECT语句;

    UPDATE语句;

    INSERT语句(仅当使用SELECT子句时有效);

    DELETE语句;

    CREATE语句(仅当使用SELECT子句时有效);

    MERGE语句(仅当作UPDATE和INSERT操作时有效)。

另外,使用SQL Profile还必须有CREATE ANY SQL PROFILE、DROP ANY SQL PROFILE和ALTER ANY SQL PROFILE等系统权限。

4.  测试一

创建表

? 1 2 3 4 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.

创建索引:

? 1 2 tpcc@TOADDB> create index t2_idx on t2(object_id); Index created.

收集统计信息:

? 1 2 3 4 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.

执行无HINT的SQL

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 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

执行带Hint的SQL

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 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

查找执行SQL的SQL_ID

? 1 2 3 4 5 6 7 8 9 10 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

运行存储过程如下:

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 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

? 1 2 3 4 tpcc@TOADDB> print tuning_task; TUNING_TASK ---------------------------------------------------------------------------------------------------- TASK_114

查看执行报告

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 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") -------------------------------------------------------------------------------

接受分析建议

报告中给出了执行方法,如上红色部分

接受报告的建议,验证一下如下:

? 1 2 tpcc@TOADDB> execute dbms_sqltune.accept_sql_profile(task_name=> 'TASK_114',task_owner => 'TPCC', replace => TRUE); PL/SQL procedure successfully completed.

执行测试

再执行原先命令如下:

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 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

启用了PROFILE,PS:如果执行中多加几个空格,并不会影响PROFILE的生效的。

5.  维护操作

禁用命令 如下:

? 1 2 3 4 5 6 7 begin dbms_sqltune.alter_sql_profile( name   => 'SYS_SQLPROF_01534b8309b90000', attribute_name => 'status', value   => 'disabled'); end; /

启用命令 如下:

? 1 2 3 4 5 6 7 begin dbms_sqltune.alter_sql_profile( name   => 'SYS_SQLPROF_01534b8309b90000', attribute_name => 'status', value   => 'enabled'); end; /

查看使用的PROFILE

如下:

? 1 SQL>SELECT task_name,status FROMUSER_ADVISOR_TASKS ;

删除PROFILE

? 1 2 3 BEGIN  DBMS_SQLTUNE.DROP_SQL_PROFILE(name => 'SYS_SQLPROF_01534b8309b90000'); END;

总结

以上所述是小编给大家介绍的Oracle固定执行计划之SQL PROFILE概要文件 ,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对网站的支持!

原文链接:https://www.cnblogs.com/DataArt/archive/2018/10/31/9881852.html