my %search_cache;
sub search_for {
   my $table = shift;
   my $value = shift;

   return $search_cache{$value} if exists $search_cache{$value};

   foreach my $row (@{$table}) {
      if ($row->{column} eq $value) {
         return $search_cache{$value} = $row;
      }
   }

   return $search_cache{$value} = undef;  # cache failure
}