揭密一致性读------之UNDO回滚链(六)
**********************************************************************************
Itl Xid Uba Flag Lck Scn/Fsc
0x01 0x0007.002.000039a5 0x00c14bec.0496.15 ---- 1 fsc 0x0000.00000000
0x02 0x0004.01a.000039be 0x00c2aafd.0433.04 C--- 0 scn 0x0000.00c6c938
itl: xid: 0x0002.01d.00004c55 uba: 0x00c0035d.050b.28
flg: C--- lkc: 0 scn: 0x0000.00c6c92a
********************************************************************************************
Uba：0x00c2aafd.0433.04===》3号文件，174845号块
sys@OCM> alter system dump datafile 3 block 174845;
UNDO BLK:
xid: 0x0004.01a.000039be seq: 0x433 cnt: 0x4 irb: 0x4 icl: 0x0 flg: 0x0000
Rec Offset Rec Offset Rec Offset Rec Offset Rec Offset
---------------------------------------------------------------------------
0x01 0x1f1c 0x02 0x1e44 0x03 0x1d6c 0x04 0x14e0
*-----------------------------
* Rec #0x4 slt: 0x1a objn: 78660(0x00013344) objd: 78660 tblspc: 7(0x00000007)
* 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: 0x00c2ae81.0434.37 ctl max scn: 0x0000.00c6c5f7 prv tx scn: 0x0000.00c6c5ff
txn start scn: scn: 0x0000.00c6c92a logon user: 90
prev brb: 12758656 prev bcl: 0
KDO undo record:
KTB Redo
op: 0x04 ver: 0x01
compat bit: 4 (post-11) padding: 1
op: L itl: xid: 0x0001.021.000039a0 uba: 0x00c2bd97.0267.01
flg: C--- lkc: 0 scn: 0x0000.00c6c924
Array Update of 1 rows:
tabn: 0 slot: 0(0x0) flag: 0x2c lock: 0 ckix: 0
ncol: 2 nnew: 1 size: 0
KDO Op code: 21 row dependencies Disabled
xtype: XAxtype KDO_KDOM2 flags: 0x00000080 bdba: 0x01c0195f hdba: 0x01c0195a
itli: 2 ispac: 0 maxfr: 4858
vect = 3
col 1: [2000]
43 43 43 43 43 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
*******************************************************************************************
Itl Xid Uba Flag Lck Scn/Fsc
0x01 0x0007.002.000039a5 0x00c14bec.0496.15 ---- 1 fsc 0x0000.00000000
0x02 0x0004.01a.000039be 0x00c2aafd.0433.04 C--- 0 scn 0x0000.00c6c938
itl: xid: 0x0002.01d.00004c55 uba: 0x00c0035d.050b.28
flg: C--- lkc: 0 scn: 0x0000.00c6c92a
itl: xid: 0x0001.021.000039a0 uba: 0x00c2bd97.0267.01
flg: C--- lkc: 0 scn: 0x0000.00c6c924
********************************************************************************************
uba: 0x00c0035d.050b.28 ===》3号文件，861号块
sys@OCM>
alter system dump datafile 3 block 861;
UNDO BLK:
xid: 0x0002.003.00004c57 seq: 0x50b cnt: 0x29 irb: 0x29 icl: 0x0 flg: 0x0000
Rec Offset Rec Offset Rec Offset Rec Offset Rec Offset
---------------------------------------------------------------------------
0x01 0x1f38 0x02 0x1e88 0x03 0x1dd8 0x04 0x1d5c 0x05 0x1cf0
0x06 0x1c68 0x07 0x1c0c 0x08 0x1b84 0x09 0x1b28 0x0a 0x1a78
0x0b 0x1a0c 0x0c 0x195c 0x0d 0x18d4 0x0e 0x1874 0x0f 0x17ec
0x10 0x178c 0x11 0x1704 0x12 0x16a8 0x13 0x15f8 0x14 0x158c
0x15 0x1520 0x16 0x1470 0x17 0x13f4 0x18 0x1344 0x19 0x12d8
0x1a 0x1228 0x1b 0x11a0 0x1c 0x113c 0x1d 0x10c0 0x1e 0x100c
0x1f 0x0f9c 0x20 0x0f2c 0x21 0x0e7c 0x22 0x0e10 0x23 0x0d60
0x24 0x0cd0 0x25 0x0c64 0x26 0x0c14 0x27 0x0b58 0x28 0x02cc
0x29 0x0244
*-----------------------------
* Rec #0x28 slt: 0x1d objn: 78660(0x00013344) objd: 78660 tblspc: 7(0x00000007)
* Layer: 11 (Row) opc: 1 rci 0x00
Undo type: Regular undo Begin