Hi,
As far as I understand, pages in an XML dump are in the order of their original creation. This does not correspond to the page ID, because if a page gets a new id after deletion and restore or renaming to that title or anything, the order still remains the original. But this sortkey itself is not stored. In other words, a dump is not sorted by any key one could finf in the dump, and behaves as an unosorted structure.
Is this true? Can I use any non-linear (e.g. binary) search in a dump?