my $ob1 = tie my %h1, 'TokyoCabinet::ADB', '*';  # in-memory hash
my $ob2 = tie my %h2, 'TokyoCabinet::ADB', '+';  # in-memory tree

my $ob3 = tie my %h3, 'KyotoCabinet::DB',  '*';  # in-memory hash
my $ob4 = tie my %h4, 'KyotoCabinet::DB',  '%';  # in-memory tree