Incidentally I was just thinking that if you really need to do your own sorting and you have issues with available memory you might consider checking out a Radix sort. The variation that saves you memory is when you write each slot (or perhaps a group of slots) out to an external file. If the partition is unsorted then just sort *that* and combine your partitions in order. Does anyone have a good reference on how a real person might implement Radix? I'd just refer back to Knuth's TAoCP vol2 but that's not for everyone.