It seems to me that it is inherently wrong to perform any operation on a
database that depends on the order in which records are retrieved,
without specifying that order in an ORDER BY clause. The "update t1 set
f1 = f1 + 1" assumes that the operation will be performed in an order
that guarantees that the highest unchanged record will be the next
record processed. I don't believe that any database system should be
required to support an action like this.
RobR