We had one data file, there was no sequence problem
for retrieving the data without order by clause.It was in sequence.

When we added another datafile and index file.
Now when program retrieves the data(no order by
it does not come in sequence. e.g if order numbers are
123456, then it retrieves as 123654.Even I run a
simple select query without order by clause, it does
the same way.

Is it possible that data may be in two different
datafiles and retrieving without order by class
resulted that(no sequency)?
It retrieves data in sequency some time ,but most of
the time it does not.