my $dbh = Read_Huge_File_Into_DB( $huge_file_path );
my @customers = Process_Customer_Information_File( $dbh, $file_path );
Print_Report(\@customers);

sub Process_Customer_Information_File {
   my $dbh = shift;
   my $file = shift;

   open( $info, '<', $file ) or die "Uh oh $!";

   my @customers_found;
   while ( my $line = <$info> ) {
       my $customer_data = ParseCustomerData($line);
       my $name = $customer_data->[NAME];

       if ( Customer_Found( $dbh, $name ) ) {
           push @customers_found, $customer_data;
       }
   }

   return @customers_found;
}