##在生成的dump文件中，寻找到8/25 Rec#0x19对应的uba地址：02000010.187e.19仍然包含在8/17 Rec#0x1中，且8/25 Rec#0x19里仍存有修改前的数据拷贝，这样既确保事务表正常回滚，也确保修改前的拷贝能被正常读取
--8/17 Rec #0x1包含有到uba: 0x02000010.187e.19的指向
*-----------------------------
* Rec #0x1 slt: 0x13 objn: 270(0x0000010e) objd: 268 tblspc: 1(0x00000001)
* 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: 0x02000010.187e.19 ctl max scn: 0x0000.00ae909b prv tx scn: 0x0000.00ae909d
txn start scn: scn: 0x0000.00ae9294 logon user: 0
prev brb: 33554461 prev bcl: 0
KDO undo record:
KTB Redo
op: 0x04 ver: 0x01
compat bit: 4 (post-11) padding: 1
op: L itl: xid: 0x0002.006.000011d2 uba: 0x0200001f.1877.01
flg: C--- lkc: 0 scn: 0x0000.00ae90b2
KDO Op code: DRP row dependencies Disabled
xtype: XA flags: 0x00000000 bdba: 0x00810de8 hdba: 0x00800192
itli: 2 ispac: 0 maxfr: 4858
tabn: 1 slot: 5(0x5)
--8/25 Rec#0x19包含有数据修改前的拷贝
*-----------------------------
* Rec #0x19 slt: 0x1e objn: 90344(0x000160e8) objd: 90344 tblspc: 8(0x00000008)
* 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: 0x02000010.187e.18 ctl max scn: 0x0000.00ae9095 prv tx scn: 0x0000.00ae909b
txn start scn: scn: 0x0000.00ae90b2 logon user: 0
prev brb: 33554460 prev bcl: 0
KDO undo record:
KTB Redo
op: 0x04 ver: 0x01
compat bit: 4 (post-11) padding: 1
op: L itl: xid: 0x0002.004.0000111f uba: 0x0200001a.177b.09
flg: C--- lkc: 0 scn: 0x0000.00ad9579
KDO Op code: URP row dependencies Disabled
xtype: XA flags: 0x00000000 bdba: 0x010006f3 hdba: 0x010006f2
itli: 2 ispac: 0 maxfr: 4858
tabn: 0 slot: 0(0x0) flag: 0x2c lock: 0 ckix: 0
ncol: 3 nnew: 1 size: 2
col 0: [ 9] 58 53 24 4e 55 4c 4c 4c 4c
select utl_raw.cast_to_varchar2(replace('58 53 24 4e 55 4c 4c 4c 4c',' ')) from dual;
UTL_RAW.CAST_TO_VARCHAR2(REPLACE('5853244E554C4C4C4C',''))
--------------------------------------------------------------------------------
XS$NULLLL
/////////////
//session 4:
/////////////
##下面再次调用proc1.sql，循环340次，这才形成了致命一击，proc1.sql输出如下：
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :1 2,21,4581,8,31,2,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :2 2,32,4582,8,31,3,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :3 2,12,4578,8,31,4,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :4 2,27,4583,8,31,5,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :5 2,5,4580,8,31,6,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :6 2,14,4581,8,31,7,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :7 2,30,4579,8,31,8,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :8 2,9,4582,8,31,9,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :9 2,10,4583,8,31,10,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :10 2,18,4580,8,31,11,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :11 2,31,4580,8,31,12,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :12 2,2,4582,8,31,13,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :13 2,22,4581,8,31,14,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :14 2,15,4580,8,31,15,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :15 2,3,4584,8,31,16,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :16 2,7,4583,8,31,17,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :17 2,13,4582,8,31,18,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :18 2,0,4582,8,31,19,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :19 2,19,4578,8,31,20,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :20 2,28,4581,8,31,21,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :21 2,29,4582,8,31,22,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :22 2,4,4578,8,31,23,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :23 2,6,4583,8,31,24,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :24 2,25,4583,8,31,25,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :25 2,16,4584,8,31,26,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :26 2,11,4581,8,31,27,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :27 2,23,4582,8,31,28,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :28 2,33,4581,8,31,29,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :29 2,1,4580,8,31,30,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :30 2,26,4582,8,31,31,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :31 2,24,4581,8,31,32,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :32 2,17,4585,8,31,33,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :33 2,8,4584,8,31,34,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :34 2,20,4582,8,31,35,6272
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :35 2,21,4582,8,16,1,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :36 2,32,4583,8,16,2,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :37 2,12,4579,8,16,3,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :38 2,27,4584,8,16,4,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :39 2,5,4581,8,16,5,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :40 2,14,4582,8,16,6,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :41 2,30,4580,8,16,7,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :42 2,9,4583,8,16,8,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :43 2,10,4584,8,16,9,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :44 2,18,4581,8,16,10,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :45 2,31,4581,8,16,11,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :46 2,2,4583,8,16,12,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :47 2,22,4582,8,16,13,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :48 2,15,4581,8,16,14,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :49 2,3,4585,8,16,15,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :50 2,7,4584,8,16,16,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :51 2,13,4583,8,16,17,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :52 2,0,4583,8,16,18,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :53 2,19,4579,8,16,19,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :54 2,28,4582,8,16,20,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :55 2,29,4583,8,16,21,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :56 2,4,4579,8,16,22,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :57 2,6,4584,8,16,23,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :58 2,25,4584,8,16,24,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :59 2,16,4585,8,16,25,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :60 2,11,4582,8,16,26,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :61 2,23,4583,8,16,27,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :62 2,33,4582,8,16,28,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :63 2,1,4581,8,16,29,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :64 2,26,4583,8,16,30,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :65 2,24,4582,8,16,31,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :66 2,17,4586,8,16,32,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :67 2,8,4585,8,16,33,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :68 2,20,4583,8,16,34,6273
XIDUSN,XIDSLOT,XIDSQN,UBAFIL,UBABLK,UBAREC,UBASQN :69 2,21,4583,8,17,1,6273
。。。。。。省略了后面的271行