1. A non-transitory computer storage medium storing computer-executable instructions that when executed by a computer cause the computer to perform corresponding functions, where the instructions are configured to cause the computer to: detect a modification to a spatial database record that includes a geometry, where records in the spatial database are configured to be viewed as one or more map tiles, further where each map tile comprises a two-dimensional rendering of geometries located within boundaries of the map tile; record, in a log table, the geometry in the record that was modified; periodically access the log table to identify map tiles that include at least one geometry of records that have been modified; periodically generate the identified map tiles; and store the generated map tiles in a cache.