How we can create a Unique Id in Perl

The better way you can use this also

use UUID::Generator::PurePerl;

sub create_search_id {
    my $this =shift;
    my $args=shift;
    my $ug = UUID::Generator::PurePerl->new();
    my $uuid1 = $ug->generate_v1();
    return $uuid1;
}

From here you can learn about UUID::Generator::PurePerl

Use Data::UUID to generate unique IDs:

use Data::UUID;

$ug    = Data::UUID->new;
$uuid1 = $ug->create();   # Or create_str()