tie my @file1_arr, 'Tie::File', $file1, mode => O_RDONLY;

foreach my $record ( @file1_arr) {
    # ...
}
untie @file1_arr; # finished with file 1

##</code><code>##

open my $fh, "<", $file1 or die "Couldn't open '$file1': $!";

while (my $record = <$fh>) {
    # ...
}
close $fh;