A geographic database is defined using hierarchical data trees and updated by changing selected portions of a data tree. A device defines a binary large object (BLOB) including map data as a first data tree and an update to the map data as a second data tree. The device computes a difference between the first data tree and the second data tree. The difference may include the data and links that are being updated. The device generates an update script including a sequence of edit operations needed to update the map data. The device may communicate the update script to a navigation device, which is configured to execute the update script to perform the update on a local version of the map data.