Rollback segment problem

["Mani, Bharati" <Bharati_Mani@WRIGHTEXPRESS.COM>]

Hi
   We are running on HP Unix, Sqr ver 3, Oracle ver 7.3

One of our sqr programs selects records from a table in a begin select block
within the block it does some processing and then it updates the record that
it is currently
reading. We are doing a commit after every 2000 records but we are running
into a rollback segment problem
ORACLE OEXEC error -1562 in cursor 14:
   ORA-01562: failed to extend rollback segment number 1
ORA-01628: max # extents (100) reached for rollback segment RBIG

When we remove the commit and let sqr commit at the end it works fine???.

We are processing roughly 12000 transactions per run.

My confusion is that I was under the impression that when we do a commit the
rollback segment is flushed out and so by commiting after every
2000 records we should not have any rollback segment problems . This is
contradicting what is currently happening.
any thoughts on this is greatly appreciated
Thanks
Bharathi