============= Program =====================
@vol = ( "vol1", "vol2" );
$contextID = 9;
$datastream = "this is just a data stream test";

( $a, $b, $c, $d, $e, $f, $g ) = split /[\s]+/, $datastream;

push @{test-$contextID-$vol[0]}, $a;
push @{test-$contextID-$vol[0]}, $b;

print "output0: @{test-$contextID-$vol[0]}\n";

push @{test-$contextID-$vol[1]}, $a;
print "output1: @{test-$contextID-$vol[1]}\n";

========= Output =====================
$ perl 1.pl
output0: this is
output1: this is this