use strict;
use warnings;
use DBI;
use DBU;

print "$$ started\n";

my $dbh = DBI->connect('DBI:Oracle:dev', 'xxx', 'yyy', {PrintError => 1});

my $depts_sql = <<EOT;
select d.id deptid
from codes c, dept d
where c.id = ? and nvl(d.cdt,sysdate+1) > sysdate and c.cd = d.id
EOT
my $depts_csr = $dbh->prepare($depts_sql);

deptid($depts_csr);

my $pid = fork;
print "$$ pid = $pid\n";
if (!defined $pid) {
   print "$$ fork error\n";
}
elsif ($pid == 0) {
   print "$$ child\n";
   $dbh->{InactiveDestroy} = 1;
   # do something here in the child process
   exit;
}

deptid($depts_csr); # this call will succeed because the child has not been reaped yet

waitpid $pid, 0;

deptid($depts_csr); # this call will fail

$dbh->disconnect;

sub deptid {
   my ($csr) = @_;
   $csr->execute('WVPLPRT');
   print "depts=";
   while (my ($deptid) = $csr->fetchrow_array) {
      print "$deptid,";
   }
   print "\n";
}

##</code><code>##

# perl problem
21754 started
depts=1,10,11,13,14,15,17,18,19,2,20,21,23,27,3,30,5,9,
21754 pid = 21757
21757 pid = 0
21757 child
depts=1,10,11,13,14,15,17,18,19,2,20,21,23,27,3,30,5,9,
DBD::Oracle::st execute failed: ORA-01001: invalid cursor (DBD: oexfet error) at problem line 42.
DBD::Oracle::st fetchrow_array failed: no statement executing (perhaps you need to call execute first) at problem line 44.
depts=