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如何使用logminer

news 来源：原创 2025/5/2 17:27:44

日志挖掘恢复

创建字典路径，并生效

mkdir -p /oracle/logmnr

alter system set utl_file_dir='/oracle/logmnr'  scope=spfile;

shutdown immediate

startup

开启补充日志

select supplemental_log_data_pk,supplemental_log_data_ui from v$database

alter database add supplemental log data (primary key, unique index) columns;

根据大致的用户错误时间，找到所需要的所有的日志（归档日志和在线重做日志）

select name from v$archived_log where first_time >=
         (select max(first_time) from v$archived_log
            where first_time <= to_date('2022-04-24 13:00:00','yyyy-mm-dd hh24:mi:ss'))
      union all
      select member from v$logfile where group#=
           (select group# from v$log where archived='NO') order by name;

构建挖掘脚本

 set trim on
 set trims on
 set term off
 set heading off
 set feedback off
 set echo off
 set linesize 500
 set pagesize 0  
 spool /oracle/logmnr.sql

select q'[exec dbms_logmnr.add_logfile(']' || name || q'[',dbms_logmnr.addfile);]' from v$archived_log
where first_time >=
   (select max(first_time) from v$archived_log  where first_time <= to_date('2021-08-24 13:00:00','yyyy-mm-dd hh24:mi:ss'))
union all
select q'[exec dbms_logmnr.add_logfile(']' ||member ||q'[',dbms_logmnr.addfile);]' from v$logfile
where group#=
   (select group# from v$log  where archived='NO') order by 1 



spool  off

开始挖掘

@logmnr.sql

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

获取挖掘结果

 set trim on
 set trims on
 set term off
 set heading off
 set feedback off
 set echo off
 set linesize 500
 set pagesize 0
 spool /oracle/logmnr/undo_logmnr.sql
 
 
 select sql_undo from v$logmnr_contents 
 where   table_name='TEST'
 and lower(sql_redo) like 'insert%';
 因为做的是误删除操作，所以在undo里面是insert
 
 SQL> select sql_undo from v$logmnr_contents 
  2     where   table_name='TEST';
insert into "QY"."TEST"("ID") values ('2');
 
 也可以创建一张临时表，创建完成后关闭挖掘

 create table tmp as select * from v$logmnr_contents 
  
  spool off

结束挖掘