undo header/block

I have been monitoring v$waitstat in my production database and found that the count for undo header and block are increasing daily by about 4 and 20 respectively. What's causing this?

Here is my rollback config:

15 of them in a LMT tablespace with uniform extent size of 0.5Mb. Each rollback has minextents of 6 and each extent is 0.5Mb. Optimal is not set!
I don't see many concurrent transactions in the database. Max # of concurrent transactions so far is 10. They are, most of time, very small transactions.

I believe I have seen a post from HJR somewhere in this newsgroup where he said he normally creates rollback segments with extent size of 8Mb or bigger.
That makes me wonder whether I have got the extent size wrong.

Any advice anyone?

rgds
Daud Received on Sat Oct 26 2002 - 07:46:18 CDT