Statspack Rollback per transaction % vs Log Miner rollback = 1

Question

Hi,
I'm investigating high Rollback per transaction % = 30% in our 9.2.0.8 EE databse .
First think was checking all archive logs from period equal to statspack snapshot range
but looks like there is huge discrepancy between that two tools .
What I've found from v$logmnr_contents where rollback = 1 was that
only 0,5% transactions was rollbacked .
I'm wondering what could cause such difference is that true
unique constraint violation (or other exceptions) is not recorded in redologs as rollbacked transaction ?
Any ideas ?
Major problem is still what is causing high rollback % .
Regards
G

Answer 1

I'm investigating increase in undo usage and Rollback per transaction % = 30 .
Strange issue because v$transacion is not showing demanding transacions , rather small quick (oltp system).
Here is sp report:
DB Name     DB Id  Instance   Inst Num Release   Cluster Host
XXXX     1497360911 XXXXX        1 9.2.0.8.0  NO   XXXXX
       Snap Id   Snap Time   Sessions Curs/Sess Comment
Begin Snap:   89346 23-Sep-09 08:00:02   638   13.0
End Snap:   89365 23-Sep-09 20:00:05   710   19.1
  Elapsed:       720.05 (mins)
Cache Sizes (end)
~~~~~~~~~~~~~~~~~
        Buffer Cache:   3,072M   Std Block Size:     8K
      Shared Pool Size:   2,048M     Log Buffer:   2,000K
Load Profile
~~~~~~~~~~~~              Per Second    Per Transaction
         Redo size:      344,858.21       6,796.87
       Logical reads:      131,932.52       2,600.28
       Block changes:       2,211.70         43.59
       Physical reads:       7,457.34        146.98
      Physical writes:        236.52         4.66
         User calls:       6,197.31        122.14
           Parses:       2,236.26         44.07
        Hard parses:         20.63         0.41
           Sorts:        330.72         6.52
           Logons:         0.34         0.01
          Executes:       3,097.97         61.06
        Transactions:         50.74
% Blocks changed per Read:  1.68  Recursive Call %:   35.95
Rollback per transaction %:  30.58    Rows per Sort:   31.38
Instance Efficiency Percentages (Target 100%)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      Buffer Nowait %:  99.97    Redo NoWait %:  100.00
      Buffer Hit  %:  94.37  In-memory Sort %:  100.00
      Library Hit  %:  99.63    Soft Parse %:   99.08
     Execute to Parse %:  27.82     Latch Hit %:   99.83
Parse CPU to Parse Elapsd %:  30.18   % Non-Parse CPU:   95.65
Shared Pool Statistics    Begin  End
       Memory Usage %: 100.00 100.00
  % SQL with executions>1:  38.24  35.74
% Memory for SQL w/exec>1:  76.94  86.29
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~                           % Total
Event                        Waits  Time (s) Ela Time
CPU time                           109,020  32.54
db file sequential read            40,144,341   96,883  28.91
db file scattered read             26,524,497   66,948  19.98
sbtwrite2                    4,141,351   23,994   7.16
SQL*Net message from dblink          33,497,630   17,097   5.10
     -------------------------------------------------------------