Undo for record that doesn't exist?

Question

hi,
version:11g
select * from emp_d1;
ID1     NAME1
1     1
2     2
3     3
4     4
5     5if i try to delete a record that does not exist
delete from emp_d1 where id1=-10;will there be any undo/redo generated?
i tried a code,
select  s.username, rn.name,     rs.curext
           ,rs.curblk,  t.used_ublk, t.used_urec
    from    v$transaction   t
           ,v$session       s
           ,v$rollname      rn
           ,v$rollstat      rs
    where  t.addr     = s.taddr
    and    t.xidusn   = rn.usn
    and    rn.usn     = rs.usn;
USERNAME     NAME     CUREXT     CURBLK     USED_UBLK     USED_UREC
TEST_DBA     _SYSSMU11_1265638203$     180     5105     1     1if there is a query which retrieves to delete non-existing records can eat up undo space?
is there a way to query the records which are there in undo segments?
thanks,
charles

Answer 1

You can try to use some flashback query features to query undo data: http://download.oracle.com/docs/cd/E11882_01/appdev.112/e17125/adfns_flashback.htm#insertedID0.