The following code snippet should help you

use strict;
use warnings;
use Tie::IxHash;

tie my %hash_var, 'Tie::IxHash';

%hash_var = (
           "grp1" => "normal,random,sequential",
           "grp2" => "willneed,dontneed,free",
           "grp3" => "access_lwp,access_many,access_default"
 );


#Print the hash
foreach my $grp (keys %hash_var) {
        my $advise_value = $hash_var{$grp};
        print "$grp ===> $advise_value\n";

}
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Hope this helps

!!@!!
May the force be with you