三、日志文件组、日志切换和日志归档

-------------Member

默认情况下，Oracle数据库实例创建完成以后就已创建了3组日志组。每组有两个日志文件(每个日志文件称为Member)，每个组内所有Member记录同样的信息，每组有两个或两个以上的Member，这样保证此日志文件的高可用性，即当其中一个文件损坏时，其他文件可用。同时为了保证HA(高可用性)建议将Redo Log File 组的每个Member实例恢复所需要的日志文件称为Active Redo Log File(活动重做日志文件)，对应的Inactive Redo Log File(非活动重做日志文件)。

在数据库实例startup时，Online Redo Log File自动前滚。

1.查看redo log，archived log

在PL/SQL SQL windows

select * from v$log;

#-----------------系统有三个redo log

select * from v$logfile;

#------------------系统有三个redo log 文件

select * from v$archived_log;

#--------------查询无archived log

2.添加archived log

在PL/SQL command windows

[oracle@h1 oracle]$ sqlplus "/as SYSDBA"

SQL*Plus: Release 11.2.0.1.0 Production on Tue Nov 13 08:37:24 2012

Copyright (c) 1982， 2009， Oracle. All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning， OLAP， Data Mining and Real Application Testing options

SQL> show parameter log_archive_dest_1;

NAME TYPE VALUE

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

log_archive_dest_1 string

log_archive_dest_10 string

log_archive_dest_11 string

log_archive_dest_12 string

log_archive_dest_13 string

log_archive_dest_14 string

log_archive_dest_15 string

log_archive_dest_16 string

log_archive_dest_17 string

log_archive_dest_18 string

log_archive_dest_19 string

四、LOGMNR

[oracle@h1 admin]$ sqlplus "/as SYSDBA"

SQL*Plus: Release 11.2.0.1.0 Production on Mon Nov 12 10:37:40 2012

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

------------------1.安装LOGMNR包

SQL> host pwd

/app/oracle/product/11.2.0/dbhome_2/rdbms/admin

SQL> @dbmslm.sql

Package created.

Grant succeeded.

Synonym created.

SQL> @dbmslmd.sql

Package created.

Synonym created.

SQL> @dbmslms.sql

Package created.

No errors.

Grant succeeded.

SQL> show parameter utl_file_dir;

NAME                                TYPE        VALUE

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

utl_file_dir                        string

------------------2.创建数据字典

SQL> alter system set utl_file_dir='/app/log' scope=spfile;

System altered.

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup

ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance

ORACLE instance started.

Total System Global Area  501059584 bytes

Fixed Size                  2214736 bytes

Variable Size            373294256 bytes

Database Buffers          121634816 bytes

Redo Buffers                3915776 bytes

Database mounted.

Database opened.

SQL> show parameter utl_file_dir;

NAME                                TYPE        VALUE

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

utl_file_dir                        string      /app/log

SQL> EXECUTE dbms_logmnr_d.build('dictionary.ora','/app/log');

PL/SQL procedure successfully completed.

------------------3.添加日志文件

SQL> host pwd

/app/oracle/oradata/orcl

SQL> EXECUTE dbms_logmnr.add_logfile(LogFileName=>'/app/oracle/oradata/orcl/redo01.log',Options=>dbms_logmnr.new);

PL/SQL procedure successfully completed.

SQL> EXECUTE dbms_logmnr.add_logfile(LogFileName=>'/app/oracle/oradata/orcl/redo02.log',Options=>dbms_logmnr.new);

PL/SQL procedure successfully completed.

SQL> EXECUTE dbms_logmnr.add_logfile(LogFileName=>'/app/oracle/oradata/orcl/redo03.log',Options=>dbms_logmnr.new);

PL/SQL procedure successfully completed.

------------------4.使用字典分析日志文件

SQL> execute dbms_logmnr.start_logmnr(dictfilename=>'/app/log/dictionary.ora');

PL/SQL procedure successfully completed.

------------------5.查询结果

SQL> select scn,sql_redo,sql_undo from v$logmnr_contents;

------------------6.退出logmnr

SQL> execute dbms_logmnr.end_logmnr;

---------------在SQL windows上用begin ...end;调用存储过程

begin

dbms_logmnr.end_logmnr;

end;