Another thing is that, for performance reason, even there is only one parameter, it is still a good idea to pass array ref, instead of array.

Well, that's not strictly true. Perl passes by reference by default. Consider:

perl -le 'sub scare { $_[0] = "boo!" } my $me; scare($me); print $me'
[download]

sub foo {
    my @args = @_;
    # ... do stuff ...  
}
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As for passing a single large array, though, there isn't much reason to pass a reference other than to be able to name it something nice in the sub rather than work directly with @_.

-sauoq
"My two cents aren't worth a dime.";