Thank you, ptum, for suggesting a better approach.

Thanks to the rest of you for the answers to my question. I looked at Programming the Perl DBI, and they do indeed point this out and suggest the following syntax:

while ($ra = $sth->fetchrow_arrayref) {
    push (@array, [@$ra]);
}
[download]

which, if I understand correctly, creates a new reference pointing to the underlying data so that when $ra changes the underlying data is still pointed to in @array.

Cheers, Brian