But, I have yet to see a computer program able to completely allocate IP space with out leaving huge holes in blocks. ARIN obviously has the largest chunk of space to manage. Oh, and a side note for the database flag bearers. Databases, don't help much, as they tend to hide the view. Allocation of IP space is akin to creation of jigsaw puzzles, that you received completed intact and must cut to pieces and reassemble to look like the original with a little loss as possible.
Databases are great methods to make allocation information available to others for digestion.
But do little to aid in the allocation process, like helping determine what size block is available for specific customer.