prev ctl max cmt scn: 0x0000.007029ac prev tx cmt scn: 0x0000.007029d6
txn start scn: 0xffff.ffffffff logon user: 32 prev brb: 12589763 prev bcl: 0 BuExt idx: 0 flg2: 0
KDO undo record:
KTB Redo
op: 0x03 ver: 0x01
compat bit: 4 (post-11) padding: 1
op: Z
KDO Op code: DRP row dependencies Disabled
xtype: XA flags: 0x00000000 bdba: 0x010000ff hdba: 0x010000fa
itli: 1 ispac: 0 maxfr: 4858
tabn: 0 slot: 0(0x0)
CHANGE #3 TYP:0 CLS:1 AFN:4 DBA:0x010000ff OBJ:22327 SCN:0x0000.003eec75 SEQ:1 OP:11.2 ENC:0 RBL:0 --OP:11.2 这个应该是插入的操作的了。
KTB Redo ----- AFN:4，插入的这个是在4号数据文件中--OBJ:22327--是插入的对象的OBJECT_ID
op: 0x01 ver: 0x01
compat bit: 4 (post-11) padding: 1
op: F xid: 0x0003.003.00000eaa uba: 0x00c01ac7.0250.25
KDO Op code: IRP row dependencies Disabled
xtype: XA flags: 0x00000000 bdba: 0x010000ff hdba: 0x010000fa
itli: 1 ispac: 0 maxfr: 4858
tabn: 0 slot: 0(0x0) size/delt: 17
fb: --H-FL-- lb: 0x1 cc: 3
null: ---
col 0: [ 2] c1 22 ---插入语句是：insert into dept values(33,'imutest','hz'); 对应是：select dump(33,16) from dual; --要注意数字在DUMP时不要加单引号
col 1: [ 7] 69 6d 75 74 65 73 74 --对应select dump('imutest',16) from dual; [7]--中括号里的是字节数，col 1:对应的是第二列，
col 2: [ 2] 68 7a ---对应 select dump('hz',16) from dual; --中括号里的是字节数 col 2: 对应 的是第三列
REDO RECORD - Thread:1 RBA: 0x000136.0000000d.01b0 LEN: 0x0060 VLD: 0x01
SCN: 0x0000.00702f09 SUBSCN: 1 01/06/2014 20:34:13 ---- OP:5.4，提交操作
CHANGE #1 TYP:0 CLS:21 AFN:3 DBA:0x00c000a0 OBJ:4294967295 SCN:0x0000.00702f08 SEQ:1 OP:5.4 ENC:0 RBL:0
ktucm redo: slt: 0x0003 sqn: 0x00000eaa srt: 0 sta: 9 flg: 0x2 ktucf redo:uba: 0x00c01ac7.0250.25 ext: 12 spc: 3380 fbi: 0
############################
实验二：update 操作的REDO日志解读
会话3： --SYS用户切换日志：SYS@ bys3>alter system switch logfile;
System altered.
SYS@ bys3>col MEMBER for a30
SYS@ bys3>select a.group#,a.sequence#,a.archived,a.status,b.type,b.member from v$log a,v$logfile b where a.group#=b.group#;
GROUP# SEQUENCE# ARC STATUS TYPE MEMBER
---------- ---------- --- ---------------- ------- ------------------------------
2 311 NO CURRENT ONLINE /u01/oradata/bys3/redo02.log
3 309 YES INACTIVE ONLINE /u01/oradata/bys3/redo03.log
切换到普通用户做更新语句：
SYS@ bys3>conn bys/bys
Connected.
BYS@ bys3>select * from dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
40 OPERATIONS BOSTON
11 chedan bj
22 test sh
33 imutest hz
6 rows selected.
BYS@ bys3>set time on
20:39:23 BYS@ bys3>update dept set dname='database' where deptno=11;
1 row updated.
20:39:43 BYS@ bys3>commit;
Commit complete.
20:39:46 BYS@ bys3>
会话4：DUMP当前REDO日志：
SYS@ bys3>alter system dump logfile '/u01/oradata/bys3/redo02.log';
System altered.
SYS@ bys3>select value from v$diag_info where name like 'De%' ;
VALUE
----------------------------------------------------------------------------------------------------
/u01/diag/rdbms/bys3/bys3/trace/bys3_ora_29141.trc
##############
查看此TRACE文件： 方法是：vi /u01/diag/rdbms/bys3/bys3/trace/bys3_ora_29141.trc 然后搜索修改的对象的OBJECT_ID:22327
UPDATE 一行记录产生一个REDO RECORD，提交产生一个REDO RECORD。非IMU下如果一个UPDATE更新多行，则会产生多条REDO RECORD。
######一个REDO RECORD: RECORD头+CHANGE VECTOR组成（一个CV就是一个操作）
REDO RECORD - Thread:1 RBA: 0x000137.00000003.0010 LEN: 0x01ec VLD: 0x05
SCN: 0x0000.00702fe0 SUBSCN: 1 01/06/2014 20:39:45
(LWN RB