从Undo Segment: _SYSSMU6_3214712007$ (6)可以知道回滚段号是6,找到 state为10的记录
index state cflags wrap# uel scn dba parent-xid nub stmt_num cmt
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0x1b 10 0x80 0x247b 0x0002 0x0000.014ce8fc 0x00000000 0x0000.000.00000000 0x00000000 0x00000000 0
其中0x1b=27
SQL> select to_number('1b','xxx') from dual;
TO_NUMBER('1B','XXX')
---------------------
27