my $parent_dbh = DBI->connect( ... );
   if( my $pid = fork() ) {
      # do stuff...
      # >>> $parent_dbh may be cleaned up here,
      # >>> because it *is* in the child's scope
      exit 0;
   }

##</code><code>##

   # fork first
   if( my $pid = fork() ) {
      # do stuff, including opening new DBI connection
      exit 0;
   }
   my $parent_dbh = DBI->connect(...);
   # do parent stuff

##</code><code>##

   my $parent_dbh = DBI->connect(...);
   $parent_dbh->{ InactiveDestroy } = 0;

   if(my $pid = fork()) {
      # do stuff
   }