in reply to Efficient giant hashes

Thanks all for your comments, they have been very helpful. My colleague is sure that the slowness of the script is due to using (big) hashes of hashes of hashes, and that it would be much faster to reimplement the system in C. I'm not so sure that would be worth the effort, and would like to do some profiling first to find out what's going on. Your comments are good ammunition for that :-)