if I've done something unwise or left something amiss

You're not checking the return values of both of your file opens. This is generally a bad thing, because reading from or writing to an un-opened filehandle yields undefined behaviour. Note that if your first open fails, you'll still attempt to do the database copy. Is that desireable?

It also seems to me that you could make your file-copy section much more efficient if you considered the File::Copy module. For example:

### Back up the file, if it exists
use File::Copy;
if(-e $file{1})  # if the file exists
{
     unless(copy($file{1}, $file{2}))
     {
          print "Failed to copy file: $!";
          exit;  # unless you want to do the copy anyway
     }
}

### Copy the database
[download]

Alternately if you like hand-rolled solutions, consider the following:

if(-e $file{1}) # if the file exists
{
   open FILE1, "< $file{1} or die "Failed to open $file{1}".        
                   " for reading: $!";
   local $/ = "";    # prepare to read the whole 
                     # file in at once
   my $filecontents = <FILE1>;
   close FILE1;
   open FILE2, "> $file{2} or die "Failed to open $file{2}".
                    " for writing: $!";
   print FILE2 $filecontents;
   close FILE2;
}
[download]

Hope that helps. :) (Oh, and note that $file1_data, or $filecontents in my example, need not be global at all.)

jarich