Rollback writes >highwater mark size

Database Enterprise Edition 8.1.7.0.0
OS 8.1.7 Hp Unix 11.0

It is kind of interesting that the rollback stats below almost consistently show the HWMSIZE is lower than the writes. I also expected some of the rollback segments to have optimal size as a result of shrinking.

Configuration of initial and next..Initial extent 4194304 next_extent 4194304
Just in case your documentation is far away below are the definitions from the docs for a reminder.
WRITES
 The number of bytes of entries written to the rollback segment.    

OPTSIZE
 The value of the optimal parameter for the rollback segment.  

HWMSIZE
 The highest value (high water mark), in bytes, of the rollback segment size reached during usage.  

SHRINKS
 The number of shrinks that the rollback segment has had to perform in order to stay at the optimal size.  

WRAPS
 The number of times a rollback segment entry has wrapped from one extent to another.  

EXTENDS
 The number of times that the rollback segment had to acquire a new extent.    

SQL> select writes,optsize,hwmsize,shrinks,wraps from v$rollstat;

    WRITES OPTSIZE HWMSIZE SHRINKS WRAPS ---------- ---------- ---------- ---------- ----------

      2580               5251072          0          0
 121459630   16777216  109682688          3         33
  52427030   16777216   16867328          0         15
  39317908   16777216   16867328          0         11
 140816400   16777216  113901568          3         39
 167348988   33554432  117547008          1         23

Appreciater your input as usual

Michael Tubuo Ngong Received on Wed Jul 02 2003 - 14:09:40 CDT