1.日志挖掘

1.1补充日志命令（日志中有了rowid）

alter databaseadd supplemental logdata;

1.2基于DML的日志挖掘

例子：SCOTT下UPDATE某记录，我想挖掘出这个操作的时间以及SCN，如

update emp set sal=9000;

步骤：

1.2.1查看当前redo日志

col member for a40

select v1.group#,v1.sequence#,v1.first_change#,v1.status,v2.member

from v$log v1,v$logfile v2

where v1.group#=v2.group#

order by 1;

结果：

GROUP# SEQUENCE# FIRST_CHANGE# STATUS MEMBER

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

1 7 1346456 CURRENT /u01/oradata/mike/redo01.log

1 7 1346456 CURRENT /u01/oradata/mike/redo01b.log

2 5 1346098 INACTIVE /u01/oradata/mike/redo02b.log

2 5 1346098 INACTIVE /u01/oradata/mike/redo02.log

3 6 1346283 INACTIVE /u01/oradata/mike/redo03b.log

3 6 1346283 INACTIVE /u01/oradata/mike/redo03.log

6 rows selected.

1.2.2使用当前日志建立分析列表

Exec sys.dbms_logmnr.add_logfile(logfilename=>'/u01/oradata/mike/redo01.log');

1.2.3使用数据字典进行日志分析

如果没有数据字典，使用dbms_logmnr.dict_from_online_catalog选项参数，意思是从指定的dbms_logmnr.add_logfile或重做日志中找到数据字典。

exec sys.dbms_logmnr.start_logmnr(options=>sys.dbms_logmnr.dict_from_online_catalog);

1.2.4查看分析结果

select scn,to_char(timestamp,'yyyy-mm-dd hh24:mi:ss'),sql_redo,sql_undo

from v$logmnr_contents

where seg_name='EMP'and seg_owner='SCOTT';

结果：

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

SQL_REDO

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

SQL_UNDO

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

1352504 2013-06-20 11:26:38

update "SCOTT"."EMP"set "SAL"= '9000'where "SAL"= '2800'and ROWID= 'AAASb2AAEAAAACXAAA';

update "SCOTT"."EMP"set "SAL"= '2800'where "SAL"= '9000'and ROWID= 'AAASb2AAEAAAACXAAA';

1352504 2013-06-20 11:26:38

update "SCOTT"."EMP"set "SAL"= '9000'where "SAL"= '2800'and ROWID= 'AAASb2AAEAAAACXAAB';

update "SCOTT"."EMP"set "SAL"= '2800'where "SAL"= '9000'and ROWID= 'AAASb2AAEAAAACX………

1.2.5结束logmnr

exec dbms_logmnr.end_logmnr;

1.3基于DDL的日志挖掘

1.3.1数据字典在归档日志中

1.3.1.1将数据字典归档到日志

execute dbms_logmnr_d.build(options=>dbms_logmnr_d.store_in_redo_logs);

1.3.1.2做DDL操作

SCOTT用户下删除表test;

drop table test;

1.3.1.3查看redo日志和archive日志

select group#,sequence#,statusfrom v$log;

结果：

GROUP# SEQUENCE# STATUS

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

1 13 INACTIVE

2 14 CURRENT

3 12 INACTIVE

select name,dictionary_begin,dictionary_endfrom v$archived_log;

结果：

NAME DIC DIC

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

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_3_8w4proqh_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_4_8w4psx1j_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_5_8w4q3sol_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_6_8w4qc0yo_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_7_8w564nnh_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_8_8w56c7gz_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_9_8w56d13f_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_10_8w56mrcn_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_11_8w5bskbb_.arc NO NO

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_12_8w5bstfx_.arc YES YES

/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_13_8w5byo0v_.arc NO NO

11 rows selected.

发现有一个归档日志中dictionary_begin和dictionary_end是YES，所以数据字典的信息在这个归档日志中，一会要加入分析队列。

1.3.1.4使用日志建立分析列表

首先把当前的redo文件加入分析列表：

execute dbms_logmnr.add_logfile(logfilename=>'/u01/oradata/mike/redo02.log',options=>dbms_logmnr.new);

然后把包含数据字典信息的归档日志也加进去：

execute dbms_logmnr.add_logfile(logfilename=>'/u01/fast_recovery_area/MIKE/archivelog/2013_06_20/o1_mf_1_12_8w5bstfx_.arc',options=>dbms_logmnr.addfile);

1.3.1.5使用数据字典进行分析

execute sys.dbms_logmnr.start_logmnr(options=>sys.dbms_logmnr.dict_from_online_catalog);

1.3.1.6查看分析结果

selectscn,to_char(timestamp,'yyyy-mm-dd hh24:mi:ss'),sql_redo from v$logmnr_contents

where seg_name='TEST' andseg_owner='SCOTT';

结果：

SCN TO_CHAR(TIMESTAMP,'

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

SQL_REDO

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

1384524 2013-06-20 15:14:59

ALTER TABLE"SCOTT"."TEST" RENAME TO"BIN$35G0QjKlCuLgRAgAJ3D0FA==$0" ;

1384527 2013-06-20 15:14:59

drop table test AS"BIN$35G0QjKlCuLgRAgAJ3D0FA==$0" ;

1.3.1.7结束logmnr

execdbms_logmnr.end_logmnr;

1.3.2数据字典在utl_file_dir中

1.3.2.1设置utl_file_dir

show parameter utl_file_dir

若为空，则设置一下值：

alter systemset utl_file_dir='/u01/logmnr'scope=spfile;

重启实例：

startup force

再次查看show parameter utl_file_dir

1.3.2.2创建数据字典到指定目录

execute dbms_logmnr_d.build(dictionary_filename=>'newdict.ora',dictionary_location=> '/u01/logmnr');

1.3.2.3查看当前redo日志和archive日志

select group#,sequence#,first_change#,statusfrom v$log;

结果：

GROUP# SEQUENCE# FIRST_CHANGE# STATUS

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

1 16 1389548 CURRENT

2 14 1384482 ACTIVE

3 15 1389541 ACTIVE