col 1: [ 8] 64 61 74 61 62 61 73 65 ---update dept set dname='database' where deptno=11;，对应select dump('database',16) from dual; col 1: [ 8] ---第二列，8位，
####################################################
REDO RECORD - Thread:1 RBA: 0x000137.00000004.0010 LEN: 0x008c VLD: 0x05
SCN: 0x0000.00702fe2 SUBSCN: 1 01/06/2014 20:39:46
(LWN RBA: 0x000137.00000004.0010 LEN: 0001 NST: 0001 SCN: 0x0000.00702fe1)
CHANGE #1 TYP:0 CLS:17 AFN:3 DBA:0x00c00080 OBJ:4294967295 SCN:0x0000.00702fe0 SEQ:1OP:5.4 ENC:0 RBL:0
ktucm redo: slt: 0x000f sqn: 0x00000e9c srt: 0 sta: 9 flg: 0x2 ktucf redo: uba: 0x00c01cbf.0250.0f ext: 4 spc: 6328 fbi: 0
###########
OP:5.4 表明是提交操作。
CHANGE #1 TYP:0 CLS:17 AFN:3 DBA:0x00c00080 OBJ:4294967295 SCN:0x0000.00702fe0 SEQ:1 OP:5.4 ENC:0 RBL:0
AFN:3 对应的是UNDO文件，
slt: 0x000f 修改了UNDO文件的这个事务槽
SCN: 0x0000.00702fe2 SUBSCN: 1 01/06/2014 20:39:46 提交操作的时间 ：
20:39:43 BYS@ bys3>commit;
Commit complete.
20:39:46 BYS@ bys3>
########################################
实验三：delete 操作的REDO日志解读
会话5： --SYS用户切换日志：alter system switch logfile;
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
---------- ---------- --- ---------------- ------- ------------------------------
1 310 YES INACTIVE ONLINE /u01/oradata/bys3/redo01.log
2 311 YES ACTIVE ONLINE /u01/oradata/bys3/redo02.log
3 312 NO CURRENT ONLINE /u01/oradata/bys3/redo03.log
切换到普通用户做删除语句：
conn bys/bys
BYS@ bys3>select * from dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
40 OPERATIONS BOSTON
22 test sh
33 imutest hz
6 rows selected.
BYS@ bys3>set time on
20:43:18 BYS@ bys3>delete dept where deptno=33;
1 row deleted.
20:43:25 BYS@ bys3>commit;
Commit complete.
会话6，DUMP当前REDO日志：
SYS@ bys3>alter system dump logfile '/u01/oradata/bys3/redo03.log';
System altered.
SYS@ bys3>select value from v$diag_info where name like 'De%' ;
VALUE
----------------------------------------------------------------------------------------------------
/u01/diag/rdbms/bys3/bys3/trace/bys3_ora_29214.trc
##############
查看此TRACE文件： 方法是：vi /u01/diag/rdbms/bys3/bys3/trace/bys3_ora_29214.trc 然后搜索修改的对象的OBJECT_ID:22327
REDO RECORD - Thread:1 RBA: 0x000138.0000002b.0010 LEN: 0x01c8 VLD: 0x05
SCN: 0x0000.0070306c SUBSCN: 1 01/06/2014 20:43:26
(LWN RBA: 0x000138.0000002b.0010 LEN: 0002 NST: 0001 SCN: 0x0000.0070306b)
CHANGE #1 TYP:0 CLS:29 AFN:3 DBA:0x00c000e0 OBJ:4294967295 SCN:0x0000.0070303f SEQ:1 OP:5.2 ENC:0 RBL:0
ktudh redo: slt: 0x0008 sqn: 0x00000e9b flg: 0x0012 siz: 168 fbi: 0
uba: 0x00c0193e.02b8.03 pxid: 0x0000.000.00000000
CHANGE #2 TYP:0 CLS:30 AFN:3 DBA:0x00c0193e OBJ:4294967295 SCN:0x0000.0070303e SEQ:1 OP:5.1 ENC:0 RBL:0
ktudb redo: siz: 168 spc: 7794 flg: 0x0012 seq: 0x02b8 rec: 0x03
xid: 0x0007.008.00000e9b
ktubl redo: slt: 8 rci: 0 opc: 11.1 [objn: 22327 objd: 22327 tsn: 4]
Undo type: Regular undo Begin trans Last buffer split: No
Temp Object: No
Tablespace Undo: No
0x00000000 prev ctl uba: 0x00c0193e.02b8.02
prev ctl max cmt scn: 0x0000.00702b2d prev tx cmt scn: 0x0000.00702b3e
txn start scn: 0xffff.ffffffff logon user: 32 prev brb: 12589367 prev bcl: 0 B