LogMiner介绍
LogMiner是用于Oracle日志挖掘的利器。
百科解释：
LogMiner 是Oracle公司从产品8i以后提供的一个实际非常有用的分析工具，使用该工具可以轻松获得Oracle 重做日志文件（归档日志文件）中的具体内容，LogMiner分析工具实际上是由一组PL/SQL包和一些动态视图组成，它作为Oracle数据库的一部分来发布，是oracle公司提供的一个完全免费的工具。
本文主要演示LogMiner的使用，直观展示LogMiner的作用。
环境：Oracle 11.2.0.4 RAC
1.查询当前日志组
使用sys用户查询Oracle数据库的当前日志组:
--1.current log
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------
1 1 29 52428800 512 2 YES INACTIVE 1547838 25-JUN-17 1547840 25-JUN-17
2 1 30 52428800 512 2 NO CURRENT 1567897 27-JUN-17 2.8147E+14 27-JUN-17
3 2 25 52428800 512 2 NO CURRENT 1567902 27-JUN-17 2.8147E+14
4 2 24 52428800 512 2 YES INACTIVE 1567900 27-JUN-17 1567902 27-JUN-17
这里当前日志（current）是：
thread 1 sequence 30
thread 2 sequence 25
2.业务用户插入操作
模拟业务用户jingyu插入T2表数据：
--2.业务用户插入操作
sqlplus jingyu/jingyu@jyzhao
SQL> select count(1) from t2;
COUNT(1)
----------
0
SQL> insert into t2 select rownum, rownum, rownum, dbms_random.string('b',50) from dual connect by level = 100000 order by dbms_random.random;
commit;
100000 rows created.
SQL>
Commit complete.
SQL> select count(1) from t2;
COUNT(1)
----------
100000
3.归档日志切换
为了区分每个日志的不同操作，这里对数据库进行手工归档切换，模拟现实中实际的归档切换。
--3.模拟归档日志切换
SQL> alter system archive log current;
System altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------
1 1 31 52428800 512 2 NO CURRENT 1572517 27-JUN-17 2.8147E+14
2 1 30 52428800 512 2 YES ACTIVE 1567897 27-JUN-17 1572517 27-JUN-17
3 2 25 52428800 512 2 YES ACTIVE 1567902 27-JUN-17 1572521 27-JUN-17
4 2 26 52428800 512 2 NO CURRENT 1572521 27-JUN-17 2.8147E+14
4.业务用户插入操作
模拟业务用户jingyu删除T2表部分数据：
--4.业务用户删除操作
SQL> delete from t2 where id 10000;
9999 rows deleted.
SQL> commit;
Commit complete.
SQL> select count(1) from t2;
COUNT(1)
----------
90001
5.归档日志切换
为了区分每个日志的不同操作，这里对数据库进行手工归档切换，模拟现实中实际的归档切换。
--5.模拟归档日志切换
SQL> alter system archive log current;
System altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------
1 1 31 52428800 512 2 YES ACTIVE 1572517 27-JUN-17 1574293 27-JUN-17
2 1 32 52428800 512 2 NO CURRENT 1574293 27-JUN-17 2.8147E+14
3 2 27 52428800 512 2 NO CURRENT 1574296 27-JUN-17 2.8147E+14
4 2 26 52428800 512 2 YES ACTIVE 1572521 27-JUN-17 1574296 27-JUN-17
6.业务用户更新操作
模拟业务用户jingyu更新T2表部分数据：
--6.业务用户更新操作
SQL> update T2 SET contents = 'xxx' where id > 99998;
2 rows updated.
SQL> commit;
Commit complete.
7.归档日志切换
为了区分每个日志的不同操作，这里对数据库进行手工归档切换，模拟现实中实际的归档切换。
--7.模拟归档日志切换
SQL> alter system archive log current;
System altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------
1 1 33 52428800 512 2 NO CURRENT 1575480 27-JUN-17 2.8147E+14
2 1 32 52428800 512 2 YES ACTIVE 1574293 27-JUN-17 1575480 27-JUN-17
3 2 27 52428800 512 2 YES ACTIVE 1574296 27-JUN-17 1575458 27-JUN-17
4 2 28 52428800 512 2 NO CURRENT 1575458 27-JUN-17 2.8147E+14
8.确认需要分析的日志
确认之后需要使用LogMiner分析的日志：
--8.确认需要分析的日志
thread# 1 sequence# 30
thread# 2 sequence# 25
这部分日志肯定是有记录插入操作
thread# 1 sequence# 31
thread# 2 sequence# 26
这部分日志肯定是有记录删除操作
thread# 1 sequence# 32
thread# 2 sequence# 27
这部分日志肯定是有记录更新操作
9.备份归档日志
将相关的归档都copy备份出来：
--9. 将相关的归档都copy备份出来
RUN {
allocate channel dev1 device type disk format '/tmp/backup/arc_%h_%e_%t';
backup as copy archivelog sequence 30 thread 1;
backup as copy archivelog sequence 31 thread 1;
backup as copy archivelog sequence 32 thread 1;
backup as copy archivelog sequence 25 thread 2;
backup as copy archivelog sequence 26 thread 2;
backup as copy archivelog sequence 27 thread 2;
release channel dev1;
}
备份出来的归档日志文件如下：
[oracle@jyrac1 backup]$ ls -lrth
total 17M
-rw-r----- 1 oracle asmadmin 2.3M Jun 27 21:50 arc_1_30_947800247
-rw-r----- 1 oracle asmadmin 591K Jun 27 21:50 arc_1_31_947800249
-rw-r----- 1 oracle asmadmin 143K Jun 27 21:50 arc_1_32_947800250
-rw-r----- 1 oracle asmadmin 9.5M Jun 27 21:50 arc_2_25_947800251
-rw-r----- 1 oracle asmadmin 3.6M Jun 27 21:50 arc_2_26_947800253
-rw-r----- 1 oracle asmadmin 77K Jun 27 21:50 arc_2_27_947800254
10.使用LogMiner分析
使用LogMiner分析归档日志：
--使用LogMiner分析归档日志
--应该有插入操作的日志
begin
dbms_logmnr.add_logfile('/tmp/backup/arc_1_30_947800247');
dbms_logmnr.add_logfile('/tmp/backup/arc_2_25_947800251');
dbms_logmnr.start_logmnr(Options=>dbms_logmnr.dict_from_online_catalog);
end;
/
--应该有删除操作的日志
begin
dbms_logmnr.add_logfile('/tmp/backup/arc_1_31_947800249');
dbms_logmnr.add_logfile('/tmp/backup/arc_2_26_947800253');
dbms_logmnr.start_logmnr(Options=>dbms_logmnr.dict_from_online_catalog);
end;
/
--应该有更新操作的日志
begin
dbms_logmnr.add_logfile('/tmp/backup/arc_1_32_947800250');
dbms_logmnr.add_logfile('/tmp/backup/arc_2_27_947800254');
dbms_logmnr.start_logmnr(Options=>dbms_logmnr.dict_from_online_catalog);
end;
/
查询v$logmnr_contents
set lines 180 pages 500
col username format a8
col sql_redo format a50
select username,scn,timestamp,sql_redo from v$logmnr_contents where table_name='T2';
select username,scn,timestamp,sql_redo from v$logmnr_contents where username='JINGYU';
select username,scn,timestamp,sql_redo from v$logmnr_contents where sql_redo like '%JINGYU%';
select username,scn,timestamp,sql_redo from v$logmnr_contents where sql_redo like 'insert%JINGYU%';
select username,scn,timestamp,sql_redo from v$logmnr_contents where sql_redo like 'delete%JINGYU%';
select username,scn,timestamp,sql_redo from v$logmnr_contents where sql_redo like 'update%JINGYU%';
实验发现，以username为条件无法查询到相关记录，最终确认username都是unknown而不是真正执行语句的业务用户jingyu。
而挖掘出的日志sql_redo这个字段是完整的SQL，可以采用like的方式查询，比如我分析更新操作的日志，就可以得到下面这样的结果：
SQL> --应该有更新操作的日志
SQL> begin
2 dbms_logmnr.add_logfile('/tmp/backup/arc_1_32_947800250');
3 dbms_logmnr.add_logfile('/tmp/backup/arc_2_27_947800254');
4 dbms_logmnr.start_logmnr(Options=>dbms_logmnr.dict_from_online_catalog);
5 end;
6 /
PL/SQL procedure successfully completed.
SQL> select count(1) from v$logmnr_contents;
COUNT(1)
----------
388
SQL> select username,scn,timestamp,sql_redo from v$logmnr_contents where username='JINGYU';
no rows selected
SQL> select username,scn,timestamp,sql_redo from v$logmnr_contents where sql_redo like '%JINGYU%';
USERNAME SCN TIMESTAMP
------------------------------ ---------- ------------
SQL_REDO
--------------------------------------------------------------------------------
UNKNOWN 1575420 27-JUN-17
update "JINGYU"."T2" set "CONTENTS" = 'xxx' where "CONTENTS" = 'YSWGNNLCLMYWPSLQ
ETVLGQJRKQIEAMOEYUFNRUQULVFRVPEDRV' and ROWID = 'AAAVWVAAGAAAAHnABj';
UNKNOWN 1575420 27-JUN-17
update "JINGYU"."T2" set "CONTENTS" = 'xxx' where "CONTENTS" = 'WHCWFOZVLJWHFWLJ
DNVSMQTORGJFFXYADIOJZWJCDDOYXAOQJG' and ROWID = 'AAAVWVAAGAAAAOYAAE';
SQL>
至此，LogMiner基本的操作实验已完成。
附：与LogMiner有关的一些操作命令参考：
conn / as sysdba
--安装LOGMINER
@$ORACLE_HOME/rdbms/admin/dbmslmd.sql;
@$ORACLE_HOME/rdbms/admin/dbmslm.sql;
@$ORACLE_HOME/rdbms/admin/dbmslms.sql;
@$ORACLE_HOME/rdbms/admin/prvtlm.plb;
--停止logmnr
exec dbms_logmnr.end_logmnr
--查询附加日志开启情况：
select supplemental_log_data_min, supplemental_log_data_pk, supplemental_log_data_ui from v$database;
--开启附加日志
alter database add supplemental log data;
--取消补充日志
alter database drop supplemental log data (primary key) columns;
alter database drop supplemental log data (unique) columns;
alter database drop supplemental log data;
--最后一个即为新的归档
select name,dest_id,thread#,sequence# from v$archived_log;
最后确认如果开启了附加日志，username就可以捕获到正确的值：
SQL> set lines 180
SQL> /
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------
1 1 35 52428800 512 2 YES INACTIVE 1590589 27-JUN-17 1591935 27-JUN-17
2 1 36 52428800 512 2 NO CURRENT 1591935 27-JUN-17 2.8147E+14
3 2 29 52428800 512 2 YES INACTIVE 1590594 27-JUN-17 1591938 27-JUN-17
4 2 30 52428800 512 2 NO CURRENT 1591938 27-JUN-17 2.8147E+14
1,36
2,30
SQL> update t2 set contents =
2 'aaa' where id = 44449;
1 row updated.
SQL> commit;
Commit complete.
RUN {
allocate channel dev1 device type disk format '/tmp/backup/arc_%h_%e_%t';
backup as copy archivelog sequence 36 thread 1;
backup as copy archivelog sequence 30 thread 2;
release channel dev1;
}
begin
dbms_logmnr.add_logfile('/tmp/backup/arc_1_36_947808116');
dbms_logmnr.add_logfile('/tmp/backup/arc_2_30_947808118');
dbms_logmnr.start_logmnr(Options=>dbms_logmnr.dict_from_online_catalog);
end;
/
SQL> select username,scn,timestamp,sql_redo from v$logmnr_contents where username='JINGYU';
USERNAME SCN TIMESTAMP
------------------------------ ---------- ------------
SQL_REDO
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
JINGYU 1593448 27-JUN-17
set transaction read write;
JINGYU 1593448 27-JUN-17
update "JINGYU"."T2" set "CONTENTS" = 'aaa' where "CONTENTS" = 'WZTSQZWYOCNDFKSMNJQLOLFUBRDOHCBMKXBHAPJSHCMWBYZJVH' and ROWID = 'AAAVWVAAGAAAACLAAL';
JINGYU 1593450 27-JUN-17
commit;
可以看到，开启了附加日志，就可以正常显示username的信息了。
总结
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