it complete.
SQL>
SQL>
begin
2
for i
in 1..100000 loop
3
update dhtest1
set object_name='DDDDDDDDDDDD'
where rownum<99;
4
commit;
5
end loop;
6
end;
7 /
PL/
SQL
procedure successfully completed. （9）dump 原先的回滚段头和undo块，发现信息已经被覆盖
SQL>
alter
system dump undo header '_SYSSMU22$';
System altered.
SQL>
alter
system dump datafile 6 block 180;
System altered. undo header trace 文件：
TRN CTL:: seq: 0x07a9 chd: 0x0020 ctl: 0x001f inc: 0x00000000 nfb: 0x0001 --seq表示该回滚段上的事务表被重用了1961次。因此事务表已经被覆盖多次
mgc: 0xb000 xts: 0x0068 flg: 0x0001 opt: 2147483646 (0x7ffffffe)
uba: 0x018000bc.07a9.23
scn: 0x0000.00150d58 ------这个SCN是事务表中最近被重用的事务表记录之前的事务的提交SCN，可以理解为已经被覆盖的事务记录中拥有最大的SCN值（事务表记录重用是按照提交SCN从小到大的顺序重用的）
Version: 0x01
FREE BLOCK POOL::
uba: 0x018000be.07a9.04 ext: 0x1 spc: 0xf12
uba: 0x00000000.07a3.05 ext: 0x1 spc: 0xa84
uba: 0x00000000.0000.24 ext: 0x0 spc: 0x124e
uba: 0x00000000.0000.00 ext: 0x0 spc: 0x0
uba: 0x00000000.0000.00 ext: 0x0 spc: 0x0
TRN TBL::
index
state cflags wrap# uel scn dba parent-xid nub stmt_num cmt
------------------------------------------------------------------------------------------------
0x00 9 0x00 0x014b 0x0002 0x0000.00150e05 0x018000bf 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x01 9 0x00 0x014b 0x000b 0x0000.00150ecf 0x018000be 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x02 9 0x00 0x014b 0x0003 0x0000.00150e19 0x018000b1 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x03 9 0x00 0x014b 0x0005 0x0000.00150e2c 0x018000b3 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x04 9 0x00 0x014b 0x0006 0x0000.00150e54 0x018000b6 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x05 9 0x00 0x014b 0x0004 0x0000.00150e3e 0x018000b4 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x06 9 0x00 0x014b 0x0007 0x0000.00150e69 0x018000b7 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x07 9 0x00 0x014b 0x0008 0x0000.00150e81 0x018000b9 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x08 9 0x00 0x014b 0x0009 0x0000.00150e94 0x018000bb 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x09 9 0x00 0x014b 0x000a 0x0000.00150eb8 0x018000bb 0x0000.000.00000000 0x00000001 0x00000000 1399886134
0x0a 9 0x00 0x014b 0x0001 0x0000.00150ec4 0x018000bd 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x0b 9 0x00 0x014b 0x000c 0x0000.00150ee2 0x018000b1 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x0c 9 0x00 0x014b 0x000d 0x0000.00150eea 0x018000b3 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x0d 9 0x00 0x014b 0x000e 0x0000.00150ef1 0x018000b3 0x0000.000.00000000 0x00000001 0x00000000 1399886134
0x0e 9 0x00 0x014b 0x000f 0x0000.00150ef8 0x018000b4 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x0f 9 0x00 0x014b 0x0010 0x0000.00150f09 0x018000b6 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x10 9 0x00 0x014b 0x0011 0x0000.00150f32 0x018000b7 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x11 9 0x00 0x014b 0x0012 0x0000.00150f45 0x018000b9 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x12 9 0x00 0x014b 0x0013 0x0000.00150f64 0x018000ba 0x0000.000.00000000 0x00000002 0x00000000 1399886134
0x13 9 0x00 0x014b 0x0014 0x0000.00150f78 0x018000bc 0x0000.000.00000000 0x00000003 0x00000000 1399886134
0x14 9 0x00 0x014b 0x0015 0x0000.00150f90 0x018000bd 0x0000.00 |