LogMiner介紹
LogMiner是用于Oracle日志挖掘的利器。
百科解釋：
LogMiner 是Oracle公司從產品8i以后提供的一個實際非常有用的分析工具，使用該工具可以輕松獲得Oracle 重做日志文件（歸檔日志文件）中的具體內容，LogMiner分析工具實際上是由一組PL/SQL包和一些動態視圖組成，它作為Oracle數據庫的一部分來發布，是oracle/9439.html">oracle/256325.html">oracle公司提供的一個完全免費的工具。
本文主要演示LogMiner的使用，直觀展示LogMiner的作用。
環境：Oracle 11.2.0.4 RAC
1.查詢當前日志組
使用sys用戶查詢Oracle數據庫的當前日志組:
--1.current logSQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------ 1 1 29 52428800 512 2 YES INACTIVE 1547838 25-JUN-17 1547840 25-JUN-17 2 1 30 52428800 512 2 NO CURRENT 1567897 27-JUN-17 2.8147E+14 27-JUN-17 3 2 25 52428800 512 2 NO CURRENT 1567902 27-JUN-17 2.8147E+14 4 2 24 52428800 512 2 YES INACTIVE 1567900 27-JUN-17 1567902 27-JUN-17
這里當前日志（current）是：
thread 1 sequence 30
thread 2 sequence 25
2.業務用戶插入操作
模擬業務用戶jingyu插入T2表數據：
--2.業務用戶插入操作sqlplus jingyu/jingyu@jyzhaoSQL> select count(1) from t2; COUNT(1)---------- 0SQL> insert into t2 select rownum, rownum, rownum, dbms_random.string('b',50) from dual connect by level <= 100000 order by dbms_random.random;commit;100000 rows created.SQL> Commit complete.SQL> select count(1) from t2; COUNT(1)---------- 1000003.歸檔日志切換
為了區分每個日志的不同操作，這里對數據庫進行手工歸檔切換，模擬現實中實際的歸檔切換。
--3.模擬歸檔日志切換SQL> alter system archive log current;System altered.SQL> select * from v$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.業務用戶插入操作
模擬業務用戶jingyu刪除T2表部分數據：
--4.業務用戶刪除操作SQL> delete from t2 where id < 10000;9999 rows deleted.SQL> commit;Commit complete.SQL> select count(1) from t2; COUNT(1)---------- 90001
5.歸檔日志切換
為了區分每個日志的不同操作，這里對數據庫進行手工歸檔切換，模擬現實中實際的歸檔切換。
--5.模擬歸檔日志切換SQL> alter system archive log current;System altered.SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------ ------------ ------------ 1 1 31 52428800 512 2 YES ACTIVE 1572517 27-JUN-17 1574293 27-JUN-17 2 1 32 52428800 512 2 NO CURRENT 1574293 27-JUN-17 2.8147E+14 3 2 27 52428800 512 2 NO CURRENT 1574296 27-JUN-17 2.8147E+14 4 2 26 52428800 512 2 YES ACTIVE 1572521 27-JUN-17 1574296 27-JUN-17
6.業務用戶更新操作
模擬業務用戶jingyu更新T2表部分數據：
--6.業務用戶更新操作SQL> update T2 SET contents = 'xxx' where id > 99998; 2 rows updated.SQL> commit;Commit complete.
7.歸檔日志切換
為了區分每個日志的不同操作，這里對數據庫進行手工歸檔切換，模擬現實中實際的歸檔切換。
--7.模擬歸檔日志切換SQL> alter system archive log current;System altered.SQL> select * from v$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.確認需要分析的日志
確認之后需要使用LogMiner分析的日志：
--8.確認需要分析的日志thread# 1 sequence# 30thread# 2 sequence# 25這部分日志肯定是有記錄插入操作thread# 1 sequence# 31thread# 2 sequence# 26這部分日志肯定是有記錄刪除操作thread# 1 sequence# 32thread# 2 sequence# 27這部分日志肯定是有記錄更新操作
9.備份歸檔日志
將相關的歸檔都copy備份出來：
--9. 將相關的歸檔都copy備份出來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;}備份出來的歸檔日志文件如下：
[oracle@jyrac1 backup]$ ls -lrthtotal 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分析歸檔日志：
--使用LogMiner分析歸檔日志--應該有插入操作的日志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;/--應該有刪除操作的日志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;/--應該有更新操作的日志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;/查詢v$logmnr_contents
set lines 180 pages 500col username format a8col sql_redo format a50 select username,scn,timestamp,sql_redo from v$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$logmnr_contents where sql_redo like 'update%JINGYU%';
實驗發現，以username為條件無法查詢到相關記錄，最終確認username都是unknown而不是真正執行語句的業務用戶jingyu。
而挖掘出的日志sql_redo這個字段是完整的SQL，可以采用like的方式查詢，比如我分析更新操作的日志，就可以得到下面這樣的結果：
SQL> --應該有更新操作的日志SQL> begin 2 dbms_logmnr.add_logfile('/tmp/backup/arc_1_32_947800250'); 3 dbms_logmnr.add_logfile('/tmp/backup/arc_2_27_947800254'); 4 dbms_logmnr.start_logmnr(Options=>dbms_logmnr.dict_from_online_catalog); 5 end; 6 /PL/SQL procedure successfully completed.SQL> select count(1) from v$logmnr_contents; COUNT(1)---------- 388SQL> select username,scn,timestamp,sql_redo from v$logmnr_contents where username='JINGYU';no rows selectedSQL> select username,scn,timestamp,sql_redo from v$logmnr_contents where sql_redo like '%JINGYU%';USERNAME SCN TIMESTAMP------------------------------ ---------- ------------SQL_REDO--------------------------------------------------------------------------------UNKNOWN 1575420 27-JUN-17update "JINGYU"."T2" set "CONTENTS" = 'xxx' where "CONTENTS" = 'YSWGNNLCLMYWPSLQETVLGQJRKQIEAMOEYUFNRUQULVFRVPEDRV' and ROWID = 'AAAVWVAAGAAAAHnABj';UNKNOWN 1575420 27-JUN-17update "JINGYU"."T2" set "CONTENTS" = 'xxx' where "CONTENTS" = 'WHCWFOZVLJWHFWLJDNVSMQTORGJFFXYADIOJZWJCDDOYXAOQJG' and ROWID = 'AAAVWVAAGAAAAOYAAE';SQL> 至此，LogMiner基本的操作實驗已完成。
附：與LogMiner有關的一些操作命令參考：
conn / as sysdba--安裝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logmnrexec dbms_logmnr.end_logmnr --查詢附加日志開啟情況：select supplemental_log_data_min, supplemental_log_data_pk, supplemental_log_data_ui from v$database; --開啟附加日志alter database add supplemental log data;--取消補充日志alter database drop supplemental log data (primary key) columns;alter database drop supplemental log data (unique) columns;alter database drop supplemental log data;--最后一個即為新的歸檔select name,dest_id,thread#,sequence# from v$archived_log;
最后確認如果開啟了附加日志，username就可以捕獲到正確的值：
SQL> set lines 180SQL> / 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+141,362,30SQL> 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-17set transaction read write;JINGYU 1593448 27-JUN-17update "JINGYU"."T2" set "CONTENTS" = 'aaa' where "CONTENTS" = 'WZTSQZWYOCNDFKSMNJQLOLFUBRDOHCBMKXBHAPJSHCMWBYZJVH' and ROWID = 'AAAVWVAAGAAAACLAAL';JINGYU 1593450 27-JUN-17commit;可以看到，開啟了附加日志，就可以正常顯示username的信息了。
總結
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