use Data::Dumper;
my @all;
my %occurance;
while (<DATA>) {
    chomp;
    push @all, [ split(/\|/,$_) ];
    $occurance{$all[-1][0]}++;
}

print Dumper(\@all);
print Dumper(\%occurance);

__DATA__
name_x|score|date
name_y|score|date
name_y|score|date
name_z|score|date
name_z|score|date