备份与恢复系列 六 续 日志挖掘Log Miner找回update语句

在上一篇的试验中使用logminer可以很容易的找到误删除的表，下面来看一个关于update的例子。 1.创建一个数据字典 EXECUTE dbms_logmnr_d.build( -         dictionary_filename => 'dictionary.ora',-         dictionary_location => '/home/oracle'); 2.产生update语句 conn scott/tiger update emp set sal=10,comm=20 where empno=7844; commit; 3，为分析制定日志文件 conn / as sysdba select member from v$logfile where group#=(select group# from v$log where status='CURRENT'); EXECUTE dbms_logmnr.add_logfile( -         logfilename => '/oradata/PRACTICE/redo03.log',-         options => dbms_logmnr.NEW); 查看将要分析的日志 select DB_NAME,THREAD_SQN,FILENAME from v$logmnr_logs; DB_NAME                  THREAD_SQN FILENAME ------------------------ ---------- ----------------------------------------- PRACTICE                         24 /oradata/PRACTICE/redo03.log 4，启动log miner conn / as sysdba EXECUTE dbms_logmnr.start_logmnr( -         dictfilename => '/home/oracle/dictionary.ora'); 查看统计信息，没有挖掘出任何数据 SELECT sql_redo,sql_undo from v$logmnr_contents where seg_name='EMP' and seg_owner='SCott' and seg_type_name='TABLE'; no rows selected 接下来有请今天的主角supplemental log 1，增加supplemental log conn / as sysdba alter database add supplemental log data; SELECT supplemental_log_data_min FROM v$database; SUPPLEMENTAL_LOG_DATA_MI ------------------------ YES 2，产生update语句 conn scott/tiger SCott@PRACTICE >update emp set sal=10,comm=20 where empno=7844; commit; 3,为分析制定日志文件 select member from v$logfile where group#=(select group# from v$log where status='CURRENT'); MEMBER -------------------------------------------------------------------------------- /oradata/PRACTICE/redo03.log SYS@PRACTICE >EXECUTE dbms_logmnr.add_logfile( - >         logfilename => '/oradata/PRACTICE/redo03.log',- >         options => dbms_logmnr.NEW); SYS@PRACTICE >select DB_NAME,FILENAME from v$logmnr_logs; DB_NAME                  THREAD_SQN ------------------------ ---------- FILENAME -------------------------------------------------------------------------------- PRACTICE                         24 /oradata/PRACTICE/redo03.log 4,启动log miner SYS@PRACTICE >EXECUTE dbms_logmnr.start_logmnr( - >         dictfilename => '/home/oracle/dictionary.ora'); PL/sql procedure successfully completed. SYS@PRACTICE >SELECT sql_redo,sql_undo   2  from v$logmnr_contents   3  where seg_name='EMP'   4  and seg_owner='SCott'   5  and seg_type_name='TABLE'; sql_REDO -------------------------------------------------------------------------------- sql_UNDO -------------------------------------------------------------------------------- update "SCott"."EMP" set "SAL" = '10',"COMM" = '20' where "SAL" = '100' and "CO MM" = '200' and ROWID = 'AAASZHAAEAAAACXAAJ'; update "SCott"."EMP" set "SAL" = '100',"COMM" = '200' where "SAL" = '10' and "C OMM" = '20' and ROWID = 'AAASZHAAEAAAACXAAJ'; 实验成功，挖掘到了update语句。 关闭日志挖掘 execute dbms_logmnr.end_logmnr; 删除supplemental log alter database drop supplemental log data;