启用 Oracle 10046 调试事件

 Oracle 10046是一个Oracle内部事件。最常用的是在Session级别设置sql_trace(alter session set sql_trace=true)即是开启了级别为1
的10046调试事件。当设置了10046事件之后，Oracle 将产生一个dump文件。通过得到的dump文件进行进一步分析，可以得到Oracle 内部执行系
统解析、调用、等待、绑定变量等详细的trace信息，对于分析系统的性能有着举足轻重的作用。

 

一、10046事件的相关参数
  该事件需要设置一些参数以控制dump文件的输出：  
  TIMED_STATISTICS
    用于控制计时信息，可以设定为true和false。当设定为true时，计时信息将会被添加到trace文件中。
  
  MAX_DUMP_FILE_SIZE
    用于控制trace文件的最大尺寸。当使用10046事件时，建议将该参数设定为unlimited。
  
  USER_DUMP_DEST
    用于设定trace文件写入到哪个文件目录
  
  STATISTICS_LEVEL
    用于控制统计信息的收集度。此参数有3个选择，baisc，typical，all。
    basic:仅收集满足trace所需的最基本的信息，象Timed statistics，Object level statistics，以及一些advisory会被忽略。
    typical:此为缺省值。此设置将在basic的基础上增加一些额外的统计信息，象操作系统耗用时间的统计信息，执行计划的统计信息都会被收集
    all:当设置为all时，所有与该session相关的信息全部会被收集。
  
  TRACEFILE_IDENTIFIER
    用于设置识别Trace文件的字符串，便于更快捷的找到生成的Trace文件。

  以上参数可以基于系统级别以及会话级别进行修改。
    ALTER SESSION/SYSTEM SET timed_statistics=true
    ALTER SESSION/SYSTEM SET max_dump_file_size=unlimited
    ALTER SESSION SET tracefile_identifier='trace_sql_example'   -->仅session级别
    
  为特定的session动态设定trace相关参数，借助DBMS_SYSTEM包
     sys.DBMS_SYSTEM.set_bool_param_in_session( &sid
                                              , &serial
                                              , 'timed_statistics'
                                              , TRUE );
     sys.DBMS_SYSTEM.set_int_param_in_session( &sid
                                             , &serial
                                             , 'max_dump_file_size'
                                             , 2147483647 );  
  
二、10046调试事件的等级
  10046调试事件可以分为多个不同的等级，不同的等级输出不同的trace信息。
  等级   作用
  0      禁止调试事件
  1      调试事件处于激活状态。针对每个被处理的数据库调用，输出SQL语句,APPNAME（应用程序名）,PARSING IN CURSOR,PARSE ERROR（SQL解析）
      ,EXEC（执行）,FETCH（获取数据）,UNMAP,SORT UNMAP（排序，临时段）,ERROR,STAT（执行计划）,XCTEND（事务）等行。
  4      包括等级1的输出，加上BIND行（绑定变量信息）
  8      包括等级1的输出，加上WAIT行（等待事件信息）。对于处理过程中的每个等待，提供如下信息：等待时间的名字，持续时间，以及一些额外
         的参数，可表明所等待的资源。
  12     输出等级4以及等级8的所有信息

 

三、激活10046调试事件

1.针对当前会话启用10046事件(常用set event)
        -- 开启当前会话级别为12的Trace，level后面的数字用于设定Trace的级别，取值为0,1,4,8,12
        ALTER SESSION SET EVENTS '10046 trace name context forever, level 12'
        -- 关闭当前会话任意级别的Trace
        ALTER SESSION SET EVENTS '10046 trace name context off'

2. 针对非当前会话启用10046事件
        sys@MMBOTST> desc dbms_system
        PROCEDURE SET_EV
         Argument Name                  Type                    In/Out Default?
         ------------------------------ ----------------------- ------ --------
         SI                             BINARY_INTEGER          IN
         SE                             BINARY_INTEGER          IN
         EV                             BINARY_INTEGER          IN
         LE                             BINARY_INTEGER          IN
         NM                             VARCHAR2                IN

        -->使用包来实现其他session的10046事件
        sys.DBMS_SYSTEM.set_ev( &input_sid
                                 , &input_serial
                                 , 10046
                                 , &input_level
                                 , NULL );
        sys.DBMS_SYSTEM.set_ev( &input_sid
                              , &input_serial
                              , 10046
                              , 0
                              , NULL );

    -->使用触发器来实现其它用户登录之后即开启10046事件
    -->为避免针对所有用户开启跟踪，建议创建一个角色，假定为sql_trace，然后将该角色授予需要进行trace的用户(create role sql_trace)
        CREATE OR REPLACE TRIGGER enable_sql_trace
           AFTER LOGON
           ON DATABASE
        BEGIN
           IF ( DBMS_SESSION.is_role_enabled( 'SQL_TRACE' ) ) THEN
              EXECUTE IMMEDIATE 'ALTER SESSION SET timed_statistics=true';

              EXECUTE IMMEDIATE 'ALTER SESSION SET max_dump_file_size=unlimited';

              EXECUTE IMMEDIATE 'ALTER SESSION SET EVENTS ''10046 trace name context forever, level 8'' ';
           END IF;
        END;
        /

3.根据client identifier来trace 多个不同的会话
    sys.DBMS_MONITOR.CLIENT_ID_TRACE_ENABLE ( client_id=>'&input_client_identifier', waits=>TRUE, binds=>FALSE );
    sys.DBMS_MONITOR.CLIENT_ID_TRACE_DISABLE ( client_id=>'&input_client_identifier' );

    使用系统自带的包来设置client identifier
    BEGIN
      dbms_session.set_identifier(client_id=>'robinson.cheng');
      dbms_application_info.set_client_info(client_info=>'Linux x86_64');
      dbms_application_info.set_module(module_name=>'test.module',
                                       action_name=>'test session');
    END;
    /

    scott@CNMMBO> SELECT client_identifier,
      2         client_info,
      3         module AS module_name,
      4         action AS action_name
      5  FROM v$session
      6  WHERE sid = sys_context('userenv','sid');

    CLIENT_IDENTIFIER         CLIENT_INFO   MODULE_NAME       ACTION_NAME
    ------------------------- ------------- ----------------- -------------------------
    robinson.cheng            Linux x86_64  test.module       test session

    -->使用下面的procedure来清除当前session的client identifier
    scott@CNMMBO> exec dbms_session.CLEAR_IDENTIFIER;

    PL/SQL procedure successfully completed.

    -->也可以使用下面的trigger来生成client identifier
    -->下面针对sql_trace角色下的用户登录之后设置client identifier
    CREATE OR REPLACE TRIGGER logon_set_identifier
       AFTER LOGON
       ON DATABASE
    DECLARE
       UID   VARCHAR2( 64 );
    BEGIN
       IF ( DBMS_SESSION.is_role_enabled( 'SQL_TRACE' ) ) THEN
          SELECT    ora_login_user
                 || ':'
                 || SYS_CONTEXT( 'USERENV', 'OS_USER' )
          INTO   UID
          FROM   dual;

          DBMS_SESSION.set_identifier( UID );
       ELSE
          NULL;
       END IF;
    END logon_set_identifier;

1.针对当前会话启用10046事件(常用set event) -- 开启当前会话级别为12的Trace，level后面的数字用于设定Trace的级别，取值为0,1,4,8,12 ALTER SESSION SET EVENTS '10046 trace name context forever, level 12' -- 关闭当前会话任意级别的Trace ALTER SESSION SET EVENTS '10046 trace name context off' 2. 针对非当前会话启用10046事件 sys@MMBOTST> desc dbms_system PROCEDURE SET_EV Argument Name Type In/Out Default? ------------------------------ ----------------------- ------ -------- SI BINARY_INTEGER IN SE BINARY_INTEGER IN EV BINARY_INTEGER IN LE BINARY_INTEGER IN NM VARCHAR2 IN -->使用包来实现其他session的10046事件 sys.DBMS_SYSTEM.set_ev( &input_sid , &input_serial , 10046 , &input_level , NULL ); sys.DBMS_SYSTEM.set_ev( &input_sid , &input_serial , 10046 , 0 , NULL ); -->使用触发器来实现其它用户登录之后即开启10046事件 -->为避免针对所有用户开启跟踪，建议创建一个角色，假定为sql_trace，然后将该角色授予需要进行trace的用户(create role sql_trace) CREATE OR REPLACE TRIGGER enable_sql_trace AFTER LOGON ON DATABASE BEGIN IF ( DBMS_SESSION.is_role_enabled( 'SQL_TRACE' ) ) THEN EXECUTE IMMEDIATE 'ALTER SESSION SET timed_statistics=true'; EXECUTE IMMEDIATE 'ALTER SESSION SET max_dump_file_size=unlimited'; EXECUTE IMMEDIATE 'ALTER SESSION SET EVENTS ''10046 trace name context forever, level 8'' '; END IF; END; / 3.根据client identifier来trace 多个不同的会话 sys.DBMS_MONITOR.CLIENT_ID_TRACE_ENABLE ( client_id=>'&input_client_identifier', waits=>TRUE, binds=>FALSE ); sys.DBMS_MONITOR.CLIENT_ID_TRACE_DISABLE ( client_id=>'&input_client_identifier' ); 使用系统自带的包来设置client identifier BEGIN dbms_session.set_identifier(client_id=>'robinson.cheng'); dbms_application_info.set_client_info(client_info=>'Linux x86_64'); dbms_application_info.set_module(module_name=>'test.module', action_name=>'test session'); END; / scott@CNMMBO> SELECT client_identifier, 2 client_info, 3 module AS module_name, 4 action AS action_name 5 FROM v$session 6 WHERE sid = sys_context('userenv','sid'); CLIENT_IDENTIFIER CLIENT_INFO MODULE_NAME ACTION_NAME ------------------------- ------------- ----------------- ------------------------- robinson.cheng Linux x86_64 test.module test session -->使用下面的procedure来清除当前session的client identifier scott@CNMMBO> exec dbms_session.CLEAR_IDENTIFIER; PL/SQL procedure successfully completed. -->也可以使用下面的trigger来生成client identifier -->下面针对sql_trace角色下的用户登录之后设置client identifier CREATE OR REPLACE TRIGGER logon_set_identifier AFTER LOGON ON DATABASE DECLARE UID VARCHAR2( 64 ); BEGIN IF ( DBMS_SESSION.is_role_enabled( 'SQL_TRACE' ) ) THEN SELECT ora_login_user || ':' || SYS_CONTEXT( 'USERENV', 'OS_USER' ) INTO UID FROM dual; DBMS_SESSION.set_identifier( UID ); ELSE NULL; END IF; END logon_set_identifier;

  4.基于组件级别与数据库级别的跟踪(略) 参考：http://docs.oracle.com/cd/E11882_01/appdev.112/e10577/d_monitor.htm

 

四、演示10046调试事件 

1.创建演示环境
    CREATE TABLE sql_trace_test
    (
       id            NUMBER
     , description   VARCHAR2( 50 )
    );

    EXEC DBMS_STATS.gather_table_stats('SCOTT', 'SQL_TRACE_TEST');

    CREATE OR REPLACE PROCEDURE populate_sql_trace_test( p_loops IN NUMBER ) AS
       l_number   NUMBER;
    BEGIN
       FOR i IN 1 .. p_loops
       LOOP
          INSERT INTO sql_trace_test( id, description )
          VALUES ( i
                 , 'Description for '
                   || i );
       END LOOP;

       SELECT COUNT( * ) INTO l_number FROM sql_trace_test;

       COMMIT;
       DBMS_OUTPUT.put_line( l_number
                            || ' rows inserted.' );
    END;
    /

    SHOW ERRORS

2.使用10046事件开启8级跟踪
    scott@CNMMBO> ALTER SESSION SET EVENTS '10046 trace name context forever, level 8';

    Session altered.

    scott@CNMMBO> EXEC populate_sql_trace_test(p_loops => 10);
    10 rows inserted.

    PL/SQL procedure successfully completed.

    scott@CNMMBO> ALTER SESSION SET EVENTS '10046 trace name context off';

    Session altered.

    scott@CNMMBO> ho ls -hltr /u02/database/CNMMBO/udump/*example*
    -rw-r----- 1 oracle oinstall 9.1K 2012-02-24 10:24 /u02/database/CNMMBO/udump/cnmmbo_ora_6667_trace_sql_example.trc

3.使用tkprof工具格式化trace file
    scott@CNMMBO> host
    oracle@SZDB:~/robinson/scripts/dba_scripts/custom/sql> cd /u02/database/CNMMBO/udump/
    oracle@SZDB:/u02/database/CNMMBO/udump> tkprof cnmmbo_ora_6667_trace_sql_example.trc sql_example.txt \
    > explain=scott/tiger sys=no sort=prsela,exeela,fchela

    TKPROF: Release 10.2.0.3.0 - Production on Fri Feb 24 10:33:16 2012

    Copyright (c) 1982, 2005, Oracle.  All rights reserved.

    oracle@SZDB:/u02/database/CNMMBO/udump> more sql_example.txt

    TKPROF: Release 10.2.0.3.0 - Production on Fri Feb 24 10:33:16 2012

    Copyright (c) 1982, 2005, Oracle.  All rights reserved.

    Trace file: cnmmbo_ora_6667_trace_sql_example.trc
    Sort options: prsela  exeela  fchela
    ********************************************************************************
    count    = number of times OCI procedure was executed
    cpu      = cpu time in seconds executing
    elapsed  = elapsed time in seconds executing
    disk     = number of physical reads of buffers from disk
    query    = number of buffers gotten for consistent read
    current  = number of buffers gotten in current mode (usually for update)
    rows     = number of rows processed by the fetch or execute call
    ********************************************************************************

    BEGIN populate_sql_trace_test(p_loops => 10); END;

    call     count       cpu    elapsed       disk      query    current        rows
    ------- ------  -------- ---------- ---------- ---------- ----------  ----------
    Parse        1      0.00       0.00          0          0          0           0
    Execute      1      0.00       0.00          0          0          0           1
    Fetch        0      0.00       0.00          0          0          0           0
    ------- ------  -------- ---------- ---------- ---------- ----------  ----------
    total        2      0.01       0.00          0          0          0           1

    Misses in library cache during parse: 1
    Optimizer mode: ALL_ROWS
    Parsing user id: 66  (SCOTT)

    Elapsed times include waiting on following events:
      Event waited on                             Times   Max. Wait  Total Waited
      ----------------------------------------   Waited  ----------  ------------
      log file sync                                   1        0.09          0.09
      SQL*Net message to client                       1        0.00          0.00
      SQL*Net message from client                     1        0.00          0.00
    ********************************************************************************

    INSERT INTO SQL_TRACE_TEST( ID, DESCRIPTION )
    VALUES
     ( :B1 , 'Description for ' || :B1 )

    call     count       cpu    elapsed       disk      query    current        rows
    ------- ------  -------- ---------- ---------- ---------- ----------  ----------
    Parse        1      0.00       0.00          0          0          0           0
    Execute     10      0.00       0.00          0          1         31          10
    Fetch        0      0.00       0.00          0          0          0           0
    ------- ------  -------- ---------- ---------- ---------- ----------  ----------
    total       11      0.00       0.00          0          1         31          10

    Misses in library cache during parse: 1
    Misses in library cache during execute: 1
    Optimizer mode: ALL_ROWS
    Parsing user id: 66  (SCOTT)   (recursive depth: 1)

  /**************************************************/
  /* Author: Robinson Cheng                         */
  /* Blog:   http://blog.csdn.net/robinson_0612     */
  /* MSN:    [email protected]              */
  /* QQ:     645746311                              */
  /**************************************************/

4.演示应用程序上的跟踪(使用client identifier)
    -->根据前面的描述创建角色并授予需要跟踪的用户以及添加client identifier的触发器，并启动应用程序
    oracle@2go-devDB01uv:/u02/database/SYBO2/udump> ls -hltr    -->移出不必要的trace文件以清除判断其产生的跟踪文件
    total 8.5K
    drwxr-xr-x 2 oracle oinstall 8.5K 2012-02-24 11:52 old

    oex_admin@SYBO2> create role sql_trace;                    -->创建角色

    Role created.

    goex_admin@SYBO2> grant sql_trace to goex_webuser;         -->将角色授予用户。注：触发器logon_set_identifier已经创建

    Grant succeeded.

    -->启动应用程序后，session的信息如下
    goex_admin@SYBO2> SELECT sid , serial#, username , client_identifier, client_info , module AS module_name
      2  FROM   v$session WHERE username is not null;

           SID    SERIAL# USERNAME             CLIENT_IDENTIFIER              CLIENT_INFO   MODULE_NAME
    ---------- ---------- -------------------- ------------------------------ ------------- -----------------
          1068       6250 GOEX_WEBUSER         GOEX_WEBUSER:Robinson.Cheng                  mBO.exe
          1073       7201 GOEX_ADMIN                                                        SQL*Plus
          1075       9115 GOEX_ADMIN                                                        SQL*Plus
          1086      60120 GOEX_ADMIN                                                        TOAD 10.5.0.41

    -->开启基于client identifier的trace
    goex_admin@SYBO2> exec DBMS_MONITOR.CLIENT_ID_TRACE_ENABLE('GOEX_WEBUSER:Robinson.Cheng',waits=>TRUE, binds=>FALSE );

    PL/SQL procedure successfully completed.

    -->调用应用程序的report 模块并生成report，此时可以看到应用程序多产生了一个session,其sid,serial分别为1078,34788
    goex_admin@SYBO2> SELECT sid , serial#, username , client_identifier, client_info , module AS module_name
      2  FROM   v$session WHERE username is not null;

           SID    SERIAL# USERNAME             CLIENT_IDENTIFIER              CLIENT_INFO   MODULE_NAME
    ---------- ---------- -------------------- ------------------------------ ------------- -----------------
          1068       6250 GOEX_WEBUSER         GOEX_WEBUSER:Robinson.Cheng                  mBO.exe
          1073       7201 GOEX_ADMIN                                                        SQL*Plus
          1075       9115 GOEX_ADMIN                                                        SQL*Plus
          1078      34788 GOEX_WEBUSER         GOEX_WEBUSER:Robinson.Cheng                  mBO.exe
          1086      60120 GOEX_ADMIN                                                        TOAD 10.5.0.41

    -->report产生后关闭基于client identifier的trace
    goex_admin@SYBO2> exec DBMS_MONITOR.CLIENT_ID_TRACE_DISABLE('GOEX_WEBUSER:Robinson.Cheng');

    PL/SQL procedure successfully completed.

    oracle@2go-devDB01uv:/u02/database/SYBO2/udump> ls -hltr     -->此时的udump目录下产生了两个trace文件
    total 409K
    drwxr-xr-x 2 oracle oinstall 8.5K 2012-02-24 11:52 old
    -rw-r----- 1 oracle oinstall 4.9K 2012-02-24 11:56 sybo2_ora_6419.trc
    -rw-r----- 1 oracle oinstall 391K 2012-02-24 11:56 sybo2_ora_6422.trc

    oracle@2go-devDB01uv:/u02/database/SYBO2/udump> cat sybo2_ora_6419.trc | grep SESSION
    *** SESSION ID:(1068.6250) 2012-02-24 11:56:19.617
    oracle@2go-devDB01uv:/u02/database/SYBO2/udump> cat sybo2_ora_6422.trc | grep SESSION
    *** SESSION ID:(1078.34788) 2012-02-24 11:56:20.650
                               IF ( DBMS_SESSION.is_role_enabled( 'SQL_TRACE' ) ) THEN
                                  DBMS_SESSION.set_identifier( UID );
    ALTER SESSION  SET NLS_CALENDAR = 'GREGORIAN'  NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS' NLS_NUMERIC_CHARACTERS = '.,'

  -->可以看到对于由应用程序衍生出来的另外一个session 也被trace，而衍生的session正是由SQL语句产生的。

1.创建演示环境 CREATE TABLE sql_trace_test ( id NUMBER , description VARCHAR2( 50 ) ); EXEC DBMS_STATS.gather_table_stats('SCOTT', 'SQL_TRACE_TEST'); CREATE OR REPLACE PROCEDURE populate_sql_trace_test( p_loops IN NUMBER ) AS l_number NUMBER; BEGIN FOR i IN 1 .. p_loops LOOP INSERT INTO sql_trace_test( id, description ) VALUES ( i , 'Description for ' || i ); END LOOP; SELECT COUNT( * ) INTO l_number FROM sql_trace_test; COMMIT; DBMS_OUTPUT.put_line( l_number || ' rows inserted.' ); END; / SHOW ERRORS 2.使用10046事件开启8级跟踪 scott@CNMMBO> ALTER SESSION SET EVENTS '10046 trace name context forever, level 8'; Session altered. scott@CNMMBO> EXEC populate_sql_trace_test(p_loops => 10); 10 rows inserted. PL/SQL procedure successfully completed. scott@CNMMBO> ALTER SESSION SET EVENTS '10046 trace name context off'; Session altered. scott@CNMMBO> ho ls -hltr /u02/database/CNMMBO/udump/*example* -rw-r----- 1 oracle oinstall 9.1K 2012-02-24 10:24 /u02/database/CNMMBO/udump/cnmmbo_ora_6667_trace_sql_example.trc 3.使用tkprof工具格式化trace file scott@CNMMBO> host oracle@SZDB:~/robinson/scripts/dba_scripts/custom/sql> cd /u02/database/CNMMBO/udump/ oracle@SZDB:/u02/database/CNMMBO/udump> tkprof cnmmbo_ora_6667_trace_sql_example.trc sql_example.txt \ > explain=scott/tiger sys=no sort=prsela,exeela,fchela TKPROF: Release 10.2.0.3.0 - Production on Fri Feb 24 10:33:16 2012 Copyright (c) 1982, 2005, Oracle. All rights reserved. oracle@SZDB:/u02/database/CNMMBO/udump> more sql_example.txt TKPROF: Release 10.2.0.3.0 - Production on Fri Feb 24 10:33:16 2012 Copyright (c) 1982, 2005, Oracle. All rights reserved. Trace file: cnmmbo_ora_6667_trace_sql_example.trc Sort options: prsela exeela fchela ******************************************************************************** count = number of times OCI procedure was executed cpu = cpu time in seconds executing elapsed = elapsed time in seconds executing disk = number of physical reads of buffers from disk query = number of buffers gotten for consistent read current = number of buffers gotten in current mode (usually for update) rows = number of rows processed by the fetch or execute call ******************************************************************************** BEGIN populate_sql_trace_test(p_loops => 10); END; call count cpu elapsed disk query current rows ------- ------ -------- ---------- ---------- ---------- ---------- ---------- Parse 1 0.00 0.00 0 0 0 0 Execute 1 0.00 0.00 0 0 0 1 Fetch 0 0.00 0.00 0 0 0 0 ------- ------ -------- ---------- ---------- ---------- ---------- ---------- total 2 0.01 0.00 0 0 0 1 Misses in library cache during parse: 1 Optimizer mode: ALL_ROWS Parsing user id: 66 (SCOTT) Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ log file sync 1 0.09 0.09 SQL*Net message to client 1 0.00 0.00 SQL*Net message from client 1 0.00 0.00 ******************************************************************************** INSERT INTO SQL_TRACE_TEST( ID, DESCRIPTION ) VALUES ( :B1 , 'Description for ' || :B1 ) call count cpu elapsed disk query current rows ------- ------ -------- ---------- ---------- ---------- ---------- ---------- Parse 1 0.00 0.00 0 0 0 0 Execute 10 0.00 0.00 0 1 31 10 Fetch 0 0.00 0.00 0 0 0 0 ------- ------ -------- ---------- ---------- ---------- ---------- ---------- total 11 0.00 0.00 0 1 31 10 Misses in library cache during parse: 1 Misses in library cache during execute: 1 Optimizer mode: ALL_ROWS Parsing user id: 66 (SCOTT) (recursive depth: 1) /**************************************************/ /* Author: Robinson Cheng */ /* Blog: http://blog.csdn.net/robinson_0612 */ /* MSN: [email protected] */ /* QQ: 645746311 */ /**************************************************/ 4.演示应用程序上的跟踪(使用client identifier) -->根据前面的描述创建角色并授予需要跟踪的用户以及添加client identifier的触发器，并启动应用程序 oracle@2go-devDB01uv:/u02/database/SYBO2/udump> ls -hltr -->移出不必要的trace文件以清除判断其产生的跟踪文件 total 8.5K drwxr-xr-x 2 oracle oinstall 8.5K 2012-02-24 11:52 old oex_admin@SYBO2> create role sql_trace; -->创建角色 Role created. goex_admin@SYBO2> grant sql_trace to goex_webuser; -->将角色授予用户。注：触发器logon_set_identifier已经创建 Grant succeeded. -->启动应用程序后，session的信息如下 goex_admin@SYBO2> SELECT sid , serial#, username , client_identifier, client_info , module AS module_name 2 FROM v$session WHERE username is not null; SID SERIAL# USERNAME CLIENT_IDENTIFIER CLIENT_INFO MODULE_NAME ---------- ---------- -------------------- ------------------------------ ------------- ----------------- 1068 6250 GOEX_WEBUSER GOEX_WEBUSER:Robinson.Cheng mBO.exe 1073 7201 GOEX_ADMIN SQL*Plus 1075 9115 GOEX_ADMIN SQL*Plus 1086 60120 GOEX_ADMIN TOAD 10.5.0.41 -->开启基于client identifier的trace goex_admin@SYBO2> exec DBMS_MONITOR.CLIENT_ID_TRACE_ENABLE('GOEX_WEBUSER:Robinson.Cheng',waits=>TRUE, binds=>FALSE ); PL/SQL procedure successfully completed. -->调用应用程序的report 模块并生成report，此时可以看到应用程序多产生了一个session,其sid,serial分别为1078,34788 goex_admin@SYBO2> SELECT sid , serial#, username , client_identifier, client_info , module AS module_name 2 FROM v$session WHERE username is not null; SID SERIAL# USERNAME CLIENT_IDENTIFIER CLIENT_INFO MODULE_NAME ---------- ---------- -------------------- ------------------------------ ------------- ----------------- 1068 6250 GOEX_WEBUSER GOEX_WEBUSER:Robinson.Cheng mBO.exe 1073 7201 GOEX_ADMIN SQL*Plus 1075 9115 GOEX_ADMIN SQL*Plus 1078 34788 GOEX_WEBUSER GOEX_WEBUSER:Robinson.Cheng mBO.exe 1086 60120 GOEX_ADMIN TOAD 10.5.0.41 -->report产生后关闭基于client identifier的trace goex_admin@SYBO2> exec DBMS_MONITOR.CLIENT_ID_TRACE_DISABLE('GOEX_WEBUSER:Robinson.Cheng'); PL/SQL procedure successfully completed. oracle@2go-devDB01uv:/u02/database/SYBO2/udump> ls -hltr -->此时的udump目录下产生了两个trace文件 total 409K drwxr-xr-x 2 oracle oinstall 8.5K 2012-02-24 11:52 old -rw-r----- 1 oracle oinstall 4.9K 2012-02-24 11:56 sybo2_ora_6419.trc -rw-r----- 1 oracle oinstall 391K 2012-02-24 11:56 sybo2_ora_6422.trc oracle@2go-devDB01uv:/u02/database/SYBO2/udump> cat sybo2_ora_6419.trc | grep SESSION *** SESSION ID:(1068.6250) 2012-02-24 11:56:19.617 oracle@2go-devDB01uv:/u02/database/SYBO2/udump> cat sybo2_ora_6422.trc | grep SESSION *** SESSION ID:(1078.34788) 2012-02-24 11:56:20.650 IF ( DBMS_SESSION.is_role_enabled( 'SQL_TRACE' ) ) THEN DBMS_SESSION.set_identifier( UID ); ALTER SESSION SET NLS_CALENDAR = 'GREGORIAN' NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS' NLS_NUMERIC_CHARACTERS = '.,' -->可以看到对于由应用程序衍生出来的另外一个session 也被trace，而衍生的session正是由SQL语句产生的。