Oracle事务原理探究2--读书笔记五 - 数据库编程

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

Oracle事务原理探究2--读书笔记五(七)