(Parent) establish database connection in $dbh.
(Parent) Fork.
(Child) $dbh_child = $dbh->connect(inherited connection parameters);
(Child) $dbh->{InactiveDestroy} = 1;
(Child) undef $dbh;
(Child) # proceed to use $dbh_child
(Parent) # proceed to use $dbh
(Child) exit;
(Parent) # continue using $dbh