The data is a basically
[[a,b],[c,d,e,...]]
where c, d and e etc could contain further array references usually no deeper than 3 but the spec for this data does not restrict it to 3. I can basically copy the first array ref and then take N of the c,d,e etc where hopefully the result when Dumped is not longer than 4K. However, it is unlikely I can get an N which provides just over 4K (reducing the work in Dumper) as c, d, e can contain other scalars of varying lengths. An ideal would be picking N which gave just over 4K when Dumped. However, although this could truncate the dumped string less than 4K when N was too small it is still a viable solution as we only need the data accurate up to the truncation and its only 4K because that is the column size - the more the better though.