1. A system for searching a map database, the system comprising: a map database comprising a plurality of sub-regions and a plurality of map objects, wherein the sub-regions comprise a central portion and a predetermined overlap portion, wherein the overlap portion is shared between multiple adjacent sub-regions, wherein each of the sub-regions is identified with one of a plurality of keys, and wherein the spatial map objects comprise spatial coordinates and are associated with one or more of said keys; and a processor configured to: receive a query for map objects within a region of spatial coordinates; identify at least one key associated with the region; and select at least one map object associated with said at least one key.