mp of buffer cache at level 4 for tsn=0, rdba=4284777
Itl Xid Uba Flag Lck Scn/Fsc
0x01 0x0003.015.0000065c 0x00c009af.01e8.1c C--- 0 scn 0x0000.0035e07c --标记被清除了
0x02 0x0004.00b.00000595 0x00c02694.0109.1d ---- 1 fsc 0x0000.00000000 --锁住了修改的行
bdba: 0x00416169
data_block_dump,data header at 0x1ce9705c
undo块转储结果
?
?
*** 2015-01-04 22:53:40.834
===================
Undo Segment Header
===================
Start dump data blocks tsn: 2 file#:3 minblk 176 maxblk 176
Block dump from cache:
Dump of buffer cache at level 4 for tsn=2, rdba=12583088
.....
TRN TBL::
index state cflags wrap# uel scn dba parent-xid nub stmt_num cmt
------------------------------------------------------------------------------------------------
0x00 9 0x00 0x0593 0x000c 0x0000.0035df6c 0x00c02693 0x0000.000.00000000 0x00000002 0x00000000 1420382305
0x01 9 0x00 0x056d 0x001e 0x0000.0035dcd1 0x00c02692 0x0000.000.00000000 0x00000001 0x00000000 1420381360
0x02 9 0x00 0x0591 0x0005 0x0000.0035de9e 0x00c02692 0x0000.000.00000000 0x00000001 0x00000000 1420381960
0x03 9 0x00 0x0594 0x0018 0x0000.0035e16f 0x00c02694 0x0000.000.00000000 0x00000001 0x00000000 1420382905
0x04 9 0x00 0x0594 0x001f 0x0000.0035e189 0x00c02694 0x0000.000.00000000 0x00000001 0x00000000 1420382905
0x05 9 0x00 0x0594 0x0009 0x0000.0035deed 0x00c02692 0x0000.000.00000000 0x00000001 0x00000000 1420382080
0x06 9 0x00 0x0594 0x0019 0x0000.0035e080 0x00c02694 0x0000.000.00000000 0x00000001 0x00000000 1420382629
0x07 9 0x00 0x0593 0x0002 0x0000.0035de5e 0x00c02692 0x0000.000.00000000 0x00000001 0x00000000 1420381815
0x08 9 0x00 0x0594 0x000a 0x0000.0035e089 0x00c02693 0x0000.000.00000000 0x00000001 0x00000000 1420382629
0x09 9 0x00 0x0592 0x001d 0x0000.0035df03 0x00c02692 0x0000.000.00000000 0x00000001 0x00000000 1420382080
0x0a 9 0x00 0x0593 0x0011 0x0000.0035e0b8 0x00c02694 0x0000.000.00000000 0x00000001 0x00000000 1420382639
0x0b 10 0x80 0x0595 0x0003 0x0000.00000000 0x00c02694 0x0000.000.00000000 0x00000001 0x00000000 0 --跟数据块的事务槽对上了
0x0c 9 0x00 0x0594 0x001c 0x0000.0035dfad 0x00c02693 0x0000.000.00000000 0x00000001 0x00000000 1420382440
0x0d 9 0x00 0x0592 0x0014 0x0000.0035ddac 0x00c02692 0x0000.000.00000000 0x00000001 0x00000000 1420381705
.....
*-----------------------------
* Rec #0x1d ?slt: 0x0b ?objn: 77560(0x00012ef8) ?objd: 77560 ?tblspc: 0(0x00000000)
* ? ? ? Layer: ?11 (Row) ? opc: 1 ? rci 0x00 ??
Undo type: ?Regular undo ? ?Begin trans ? ?Last buffer split: ?No?
Temp Object: ?No?
Tablespace Undo: ?No?
rdba: 0x00000000Ext idx: 0
flg2: 0
*-----------------------------
uba: 0x00c02694.0109.1c ctl max scn: 0x0000.0035dc32 prv tx scn: 0x0000.0035dc72
txn start scn: scn: 0x0000.0035e1d6 logon user: 0
?prev brb: 12592785 prev bcl: 0
KDO undo record:
KTB Redo?
op: 0x03 ?ver: 0x01 ?
compat bit: 4 (post-11) padding: 0
op: Z
KDO Op code: URP row dependencies Disabled
? xtype: XA flags: 0x00000000 ?bdba: 0x00416169 ?hdba: 0x00416168
itli: 2 ?ispac: 0 ?maxfr: 4863
tabn: 0 slot: 0(0x0) flag: 0x2c lock: 0 ckix: 0
ncol: 2 nnew: 1 size: -1
col ?1: [ 2] ?c1 02-- 这是数据块事务槽uba的地址指向的undo记录，c1 02 代表着1，说明修改前是1.
?
序号3执行完后
数据块转储结果
*** 2015-01-04 23:06:25.105
Block dump from cache:
Dump of buffer cache at level 4 for tsn=0, rdba=4284777
.....
Itl Xid Uba Flag Lck Scn/Fsc
0x01 0x0003.015.0000065c 0x00c0