An aside: When storing large quantities of things like this my personal preference is to split the id from the end.
I was once i charge of a large number of images of book jackets named by the books' isbn. At least in that population (which of course is an extreme example considering how an isbn is created) the distribution is much more even (that is, the directory sizes are relatively equal) when using the end than the beginning, but I would not be surprised if that is a normal outcome.
I was once i charge of a large number of images of book jackets named by the books' isbn. At least in that population (which of course is an extreme example considering how an isbn is created) the distribution is much more even (that is, the directory sizes are relatively equal) when using the end than the beginning, but I would not be surprised if that is a normal outcome.
Maybe it's an application of Benford's law [1].
[1] http://en.wikipedia.org/wiki/Benford%27s_law