use DBI;

use threads;
use threads::shared;

my $driver   = 'SQLite';
my $database = '';
my $dsn      = '';
my $userid   = '';
my $password = '';

my $dbh;
my $dsn;
my $stmt;
my $sth;
my $rv;
my @row;

my %hash;

my %hsh :shared;
my $int :shared;

my $String;
my $Sdatabase;

$Sdatabase = $ARGV[0];
print 'Database fully qualified path of existing SQLite DB -> ' . $Sdatabase . "\n";

$dsn = "DBI:$driver:dbname=$Sdatabase";
print 'Database data source name for connect -> ' . $dsn . "\n";

   $dbh = DBI->connect($dsn, $userid, $password, { PrintError => 1, RaiseError => 1, AutoCommit => 0, ReadOnly => 1 });
print 'Simple database handle in $dbh from connect -> ' . $dbh . " and DB is now open\n";

   $hash{"$Sdatabase"} = $dbh;
print 'Simple database handle in non-shared Hash, $Sdatabase -> ' . $Sdatabase . '  and $hash{"$Sdatabase"} -> ' . $hash{"$Sdatabase"} . "\n";

   $stmt = qq(select count ( * ) from asnipv4 );
   $sth = $hash{"$Sdatabase"}->prepare( $stmt );

   $rv = $sth->execute();

   while( @row = $sth->fetchrow_array()) {
      $Iknt++;
      $String = join ',', @row;
      print "$Iknt -> $String \n";
   }

   $hash{$Sdatabase}->disconnect();
   delete $hash{$Sdatabase};

#   $int = $dbh;
#print 'Try to get simple database handle in shared scalar $int as  -> ' . $int . "\n";

   $int = shared_clone(\$dbh);
print 'Try to get simple database handle in shared scalar $int via shared_clone(\$dbh) -> ' . $int . " <- the original handle is gone and now we have a reference\n";

   $hash{"$Sdatabase"} = $int;
print 'Try to get shared scalar $int database handle into a non-shared Hash $Sdatabase -> ' . $Sdatabase . '  and $hash{"$Sdatabase"} -> ' . $hash{"$Sdatabase"} . " <- works but we have a reference and not the handle\n";

   $hsh{"$Sdatabase"} = $int;
print 'Try to get shared scalar $int database handle into a shared Hash $Sdatabase -> ' . $Sdatabase . ' has $hsh{"$Sdatabase"} -> ' . $hsh{"$Sdatabase"} . " <- BUT the simple = results in some other reference\n";

   $stmt = qq(select count ( * ) from asnipv4 );
   $sth = $hsh{"$Sdatabase"}->prepare( $stmt );

   $rv = $sth->execute();

   while( @row = $sth->fetchrow_array()) {
      $Iknt++;
      $String = join ',', @row;
      print "$Iknt -> $String \n";
   }

   $hsh{$Sdatabase}->disconnect();
   delete $hsh{$Sdatabase};

exit;

##</code><code>##

[root@itx2 ~]# perl x7.pl /opt/asd/sql/dbi-indexed-GeoLite2.db-sqlite-old
Database fully qualified path of existing SQLite DB -> /opt/asd/sql/dbi-indexed-GeoLite2.db-sqlite-old
Database data source name for connect -> DBI:SQLite:dbname=/opt/asd/sql/dbi-indexed-GeoLite2.db-sqlite-old
Simple database handle in $dbh from connect -> DBI::db=HASH(0x561e4b5e5480) and DB is now open
Simple database handle in non-shared Hash, $Sdatabase -> /opt/asd/sql/dbi-indexed-GeoLite2.db-sqlite-old  and $hash{"$Sdatabase"} -> DBI::db=HASH(0x561e4b5e5480)
1 -> 511665
Try to get simple database handle in shared scalar $int via shared_clone(\$dbh) -> REF(0x561e4b2b9570) <- the original handle is gone and now we have a reference
Try to get shared scalar $int database handle into a non-shared Hash $Sdatabase -> /opt/asd/sql/dbi-indexed-GeoLite2.db-sqlite-old  and $hash{"$Sdatabase"} -> REF(0x561e4b2b9570) <- works but we have a reference and not the handle
Try to get shared scalar $int database handle into a shared Hash $Sdatabase -> /opt/asd/sql/dbi-indexed-GeoLite2.db-sqlite-old has $hsh{"$Sdatabase"} -> REF(0x561e4b5e5630) <- BUT the simple = results in some other reference
Can't call method "prepare" on unblessed reference at x7.pl line 66.
[root@itx2 ~]#