《undo异常事务回滚规则分析》的评论 https://www.xifenfei.com/2013/03/undo%e5%bc%82%e5%b8%b8%e4%ba%8b%e5%8a%a1%e5%9b%9e%e6%bb%9a%e8%a7%84%e5%88%99%e5%88%86%e6%9e%90.html 提供7*24专业数据库(Oracle,SQL Server,MySQL,PostgreSQL等)恢复和技术支持@Tel:17813235971 Thu, 11 Dec 2025 02:46:14 +0000 hourly 1 作者：惜分飞 https://www.xifenfei.com/2013/03/undo%e5%bc%82%e5%b8%b8%e4%ba%8b%e5%8a%a1%e5%9b%9e%e6%bb%9a%e8%a7%84%e5%88%99%e5%88%86%e6%9e%90.html/comment-page-1#comment-1300 Sun, 10 Mar 2013 14:23:03 +0000 https://www.xifenfei.com/?p=4183#comment-1300 补充在单个undo block中回滚记录顺序判断规则

********************************************************************************
UNDO BLK:
xid: 0x0001.004.000001c5 seq: 0x18 cnt: 0xe irb: 0xe icl: 0x0 flg: 0x0000     <==== (1)

 Rec Offset      Rec Offset      Rec Offset      Rec Offset      Rec Offset
---------------------------------------------------------------------------
0x01 0x0734     0x02 0x0698     0x03 0x0624     0x04 0x05b0     0x05 0x053c
0x06 0x04c8     0x07 0x0454     0x08 0x03e0     0x09 0x036c     0x0a 0x02f8
0x0b 0x0284     0x0c 0x01e8     0x0d 0x0174     0x0e 0x0100

... /* Dumps of undo records 0x01 - 0x0b left out here for clarity. */

*-----------------------------
* Rec #0xc  slt: 0x04  objn: 10480(0x000028f0)  objd: 10480  tblspc: 0(0x00000000)     <===== (5)
*       Layer:  11 (Row)   opc: 1   rci 0x00
Undo type:  Regular undo    Begin trans    Last buffer split: No 
Temp Object:  No 
Tablespace Undo:  No 
rdba: 0x00000000
*-----------------------------
uba: 0x0080f1e4.0018.02 ctl max scn: 0x0000.00039cb4 prv tx scn: 0x0000.00039d36
txn start scn: scn: 0x0000.00000000 logon user: 0
 prev brb: 8450530 prev bcl: 0
KDO undo record:
KTB Redo 
op: 0x03 ver: 0x01 
op: Z
KDO Op code: URP row dependencies Disabled
  xtype: XA flags: 0x00000000  bdba: 0x00416b22  hdba: 0x00416b21
itli: 2  ispac: 0  maxfr: 1177
tabn: 0 slot: 0(0x0) flag: 0x2c lock: 0 ckix: 8
ncol: 1 nnew: 1 size: -29
col  0: [29]
 54 68 69 73 20 69 73 20 72 6f 77 20 31 20 77 69 74 68 20 73 6f 6d 65 20 74
 65 78 74 2e

*-----------------------------
* Rec #0xd  slt: 0x04  objn: 10480(0x000028f0)  objd: 10480  tblspc: 0(0x00000000)     <===== (4)
*       Layer:  11 (Row)   opc: 1   rci 0x0c 
Undo type:  Regular undo   Last buffer split:  No 
Temp Object:  No 
Tablespace Undo:  No 
rdba: 0x00000000
*-----------------------------
KDO undo record:
KTB Redo 
op: 0x02  ver: 0x01 
op: C  uba: 0x0080f1e4.0018.0c
KDO Op code: URP row dependencies Disabled
  xtype: XA flags: 0x00000000  bdba: 0x00416b22  hdba: 0x00416b21
itli: 2  ispac: 0  maxfr: 1177
tabn: 0 slot: 1(0x1) flag: 0x2c lock: 0 ckix: 8
ncol: 1 nnew: 1 size: -29
col  0: [29]
 54 68 69 73 20 69 73 20 72 6f 77 20 32 20 77 69 74 68 20 73 6f 6d 65 20 74
 65 78 74 2e

*-----------------------------
* Rec #0xe  slt: 0x04 objn: 10480(0x000028f0) objd: 10480 tblspc: 0(0x00000000)     <===== (2)
*       Layer:  11 (Row)   opc: 1   rci 0x0d 
Undo type:  Regular undo   Last buffer split:  No 
Temp Object:  No 
Tablespace Undo:  No 
rdba: 0x00000000
*-----------------------------
KDO undo record:
KTB Redo 
op: 0x02  ver: 0x01 
op: C  uba: 0x0080f1e4.0018.0d
KDO Op code: URP row dependencies Disabled
  xtype: XA flags: 0x00000000  bdba: 0x00416b22  hdba: 0x00416b21     <===== (3)
itli: 2  ispac: 0  maxfr: 1177
tabn: 0 slot: 2(0x2) flag: 0x2c lock: 0 ckix: 8
ncol: 1 nnew: 1 size: -29
col  0: [29]
 54 68 69 73 20 69 73 20 72 6f 77 20 33 20 77 69 74 68 20 73 6f 6d 65 20 74
 65 78 74 2e
]]>