On Jul 2, 2008, at 4:43 PM, Alan Keown wrote: > I was struck at the time that managing this data would be a difficult, > almost incomprehensible, task. In pondering this problem I had the > idea that > location (2D, 3D or 4D as required) provides a unique key for any > model > element in a database. (No two things can occupy the same location > if your > coordinate precision is fine enough.)
The problem is creating a data structure and algorithm that will preserve and expose all the underlying spatial relationships that unique key represents. Otherwise, you essentially end up with a hash table which is of limited value for most purposes (or we'd already be doing that). This turns out to be a hard problem, with thousands of pages of published literature spanning decades and no generally usable solutions. You don't want a hash table per se, you want direct content-addressability of arbitrary hyper-rectangles in that coordinate space, which is (much) trickier under real-world design constraints. > Now that the "Google method" has become spatially enabled maybe they > will be > able to "move from traditional maps to a massive database of spatial > information like the world has moved from print publications to the > digital > information available on the web" (to quote Landon). I think you might be misinterpreting this, as Google only supports a pseudo-spatial database that is very limited in nature. See above about this being a "hard problem"; solving that problem is theoretically equivalent to solving a lot of other important problems that would obviate a lot of their existing software infrastructure, including the Big Table database architecture. However, you are correct about the impact, indeed underestimate it, if someone built a Google-like infrastructure that generalized to arbitrary types and spaces. The kinds of analytics that could be efficiently done are mind-boggling, and it would make the Google of today look like how the Google of today makes the old search engines of the 1990s look. But it will take new computer science first, and the most interesting work being done in that space is by startup ventures rather than an established player. The circle of life in high technology. :-) Cheers, J. Andrew Rogers _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
