Retrieving data from Oracle

Hi,

I'm migrating a perl application in postgres to Oracle.  Here, the data is
being retrieved as below.

  while ($row = $sth->fetchrow_hashref()) {
    push (@list,$row);
  }

It looks like fetchrow_hashref() is not working with Oracle.  But I'm able
to retrieve the data through fetchrow_array.  Any idea why
fetchrow_hashref() is not working?  Is there any other alternative for
fetchrow_hashref()?  How do I accomplish the above with any other fetch
methods?

Thanks in advance.

Sangeeth