[eygle]Oracle Internal Events Introduction

Oracle Internal Events Introduction

链接： http://www.eygle.com/digest/2008/04/oracle_internal_events_introdu.html

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Introduction:(简介)

有四种类型的Events:

                Immediate dumps

               Conditional dumps

               Trace dumps

               Events that change database behaviour

每一个事件都有一个号跟Oracle的错误信息是一样的.如10046和ORA-10046

每一个事件都有一个Level,可以是以下:

              范围1到10

              位标 0x01 0x02 0x04 0x08 0x10

              标识 0=off,1=on

              ID号 对象ID(object id),内存地址(memory address)

要注意的是,Events在每一个版本之间都有所改变.有一些存在的事件可能存在争议性或者已经不可用了,往往这些事件号会由新的事件所替代掉.也要注意在当前的版本中message file不一定可以反映出Events.

很多Events都会影响数据库的行为,一些测试Events极有可能导致数据库DOWN掉.所以,在没有Oracle Support的前提下,最好不要在PRO系统上做Events操作.DEV系统上如果要做Events最好先做个数据库的全备份.

 

Enabling Events(Enable事件)

Events可以在Instance一级Enabled,主要是在INIT.ORA文件中做操作:

        event='event trace name context forever, level level';

(红色部分:event指事件号.level指定事件的级别)

  一次可以Enable多个事件,可以用以下两种方式:

1.  用一个冒号隔开

     event = "10248 trace name context forever, level 10:10249 trace name context forever, level 10"

2.  两个Events分开写

    event="10248 trace name context forever, level 10"

    event="10249 trace name context forever, level 10"#一些版本的Oracle，event要一样的大小写

Events也可以在Instance一级用ALTER SYSTEM命令来Enable:

      ALTER SYSTEM SET EVENTS 'event trace name context forever, level level';

　在Instance一级用以下Disable

      ALTER SYSTEM SET EVENTS 'event trace name context off';

  Events也可以在Session一级用ALTER SESSION命令来Enable:

      ALTER SESSION SET EVENTS 'event trace name context forever, level level';

  在Session一级用以下命令Disable:

ALTER SESSION SET EVENTS 'event trace name context off';

 Events在其他的Session用ORADEBUG来Enable:

 在一个Process中实现Enable:

      ORADEBUG EVENT event TRACE NAME CONTEXT FOREVER, LEVEL level

 在某个进程中Enable:

      ORADEBUG SETORAPID 8(PID进程号)

      ORADEBUG EVENT event TRACE NAME CONTEXT FOREVER, LEVEL level

 以下命令Disable:

  ORADEBUG EVENT event TRACE NAME CONTEXT OFF

在Session中实现Enable:

  ORADEBUG SESSION_EVENT event TRACE NAME CONTEXT FOREVER, LEVEL level

在Session中实现Disable:

  ORADEBUG SESSION_EVENT event TRACE NAME CONTEXT OFF

Events也可以用DBMS_SYSTEM.SETEV包来实现Enable和Disable

    (在做之前要先从V$session视图中获得SID和Serial#)

用以下方式:EXECUTE DBMS_SYSTEM.SET_EV(SID,Serial#,event,level, '')

如EXECUTE dbms_system.set_ev (9,29,10046,8,'');

  要Disable则将level改为0,如: EXECUTE dbms_system.set_ev (9,29,10046,0,'');

Listing All Events:(列出所有可用的Events)

大部分的Events number的范围都在10000到10999.可以用以下命令Dump出所有的信息

SET SERVEROUTPUT ON

DECLARE

   err_msg VARCHAR2(120);

BEGIN

   dbms_output.enable (1000000);

   FOR err_num IN 10000..10999

   LOOP

    err_msg := SQLERRM (-err_num);

    IF err_msg NOT LIKE '%Message '||err_num||' not found%' THEN

      dbms_output.put_line (err_msg);

    END IF;

  END LOOP;

END;

/

在UNIX系统下message文件在底下目录$ORACLE_HOME/rdbms/mesg/oraus.msg

在NT系统下message文件在底下目录$ORACLE_HOME/rdbms/mesg/oraus.msg

Listing Enabled Events(列出Enabled Events)

  用以下命令列出在当前Session已经Enabled Events:

           SET SERVEROUTPUT ON

           DECLARE

               l_level NUMBER;

           BEGIN

               FOR l_event IN 10000..10999

               LOOP

                         dbms_system.read_ev (l_event,l_level);

                         IF l_level > 0 THEN

                          dbms_output.put_line ('Event '||TO_CHAR (l_event)||

                               ' is set at level '||TO_CHAR (l_level));

                         END IF;

                END LOOP;

              END;

             /

常用Events的参考:(红色的为最常用的而且对DBA比较有用的Events)

Event 10013 - Monitor Transaction Recovery------在Startup时跟踪事务恢复

           ALTER SESSION SET EVENTS '10013 trace name context forever, level 1';

Event 10015 - Dump Undo Segment Headers----在事务恢复后做Dump回退段头信息

           ALTER SESSION SET EVENTS '10015 trace name context forever, level 1';

Event 10032 - Dump Sort Statistics----Dump排序的统计信息,level 10是最详细的

            ALTER SESSION SET EVENTS '10032 trace name context forever, level 10';

Event 10033 - Dump Sort Intermediate Run Statistics--level 10

              ALTER SESSION SET EVENTS '10033 trace name context forever, level 10';

Event 10045 - Trace Free List Management Operations--跟踪Freelist

             ALTER SESSION SET EVENTS '10045 trace name context forever, level 1';

Event 10046 - Enable SQL Statement Trace---跟踪SQL,有执行计划,邦定变量和等待的统计信息,level 12最详细

           ALTER SESSION SET EVENTS '10046 trace name context forever, level 12';

级别level参考如下图:

Level Action 1 Print SQL statements, execution plans and execution statistics 4 As level 1 plus bind variables 8 As level 1 plus wait statistics 12 As level 1 plus bind variables and wait statistics

Event 10053 - Dump Optimizer Decisions---在分析SQL语句时,Dump出优化器所做的选择,级别level 1最详细

            ALTER SESSION SET EVENTS '10053 trace name context forever, level 1';

参考level:

Level	Action
1	Print statistics and computations
2	Print computations only

Event 10060 - Dump Predicates---(参考http://www.juliandyke.com/)

Event 10065 - Restrict Library Cache Dump Output for State Object Dumps-(参考http://www.juliandyke.com/)

Event 10079 - Dump SQL*Net Statistics---Dump SQL*NeT的统计信息

            ALTER SESSION SET EVENTS '10079 trace name context forever, level 2';

Event 10081 - Trace High Water Mark Changes--跟踪HWM的改变

            ALTER SESSION SET EVENTS '10081 trace name context forever, level 1';

Event 10104 - Dump Hash Join Statistics--Dump HASH JOIN的统计信息,用level 10

             ALTER SESSION SET EVENTS '10104 trace name context forever, level 10';

Event 10128 - Dump Partition Pruning Information--Dump分区表信息

               ALTER SESSION SET EVENTS '10128 trace name context forever, level level';

  Level参考

Level	Action
0x0001	Dump pruning descriptor for each partitioned object
0x0002	Dump partition iterators
0x0004	Dump optimizer decisions about partition-wise joins
0x0008	Dump ROWID range scan pruning information

在9.0.1或者后面的版本,在level 2后还需要建立如下的表:

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