A few thoughts:

• Your dbh setup looks overly complicated. Could you explain why you couldn't do something like:

  my $dbh = DBI->connect(
      $connect_string,
      $user,
      $pass,
  );
  
  die "Couldn't connect to DBI\n" unless $dbh;
  $dbh->{RaiseError} = 1;
  [download]

• Whenever I see a bunch of variables defined at the top, I cringe. Having one or two globals ... I can see. These would be things along the lines of $dbh and the like. 12 is a little much.
• Why does everyone need to know about $even? It's used in exactly two places. In fact, you calculate it in one place, then use the result in another. Why not just calculate it in the place you use it? At least, calculate it in the function you use it ...
• You don't check the return result of $dbh->prepare(), even though you're passing it a dynamically-generated SQL statement. You also don't call $sth->finish(). This isn't a problem, until you use prepare_cached(). It's just a good habit to get into.
• You can do the following type of replacement in a lot of places:

  for ( my $i = 0; $i < scalar(@mini) ; $i++ )
  {
      delete $mini[$i]{'MajorDescription'};
      delete $mini[$i]{'MajorKey'};
      delete $mini[$i]{'hits'};
  }
  
  ----
  
  foreach my $i (0 .. $#mini)
  {
      delete $mini[$i]{$_}
          for qw(MajorDescription MajorKey hits);
  }
  [download]

------
We are the carpenters and bricklayers of the Information Age.

The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.