If I read your question right (correct me if I'm wrong, it's a small data sample) you are asking how to sort the results by height, ascending.

If so, it makes the most sense to do it in SQL, ie SELECT Name, Age, Height FROM table ORDER BY Height ASC. Then you could step through it row by row, regardless of the size of the dataset returned.

If it must be sorted in perl, you'll need to either use one of the "fetchall*" methods or loop through all rows to store the full result set before sorting.

HTH