Abstract: This invention generally relates to methods, systems, data structures and computer program code for managing spatial data, in particular very large volumes of data such as map data for a region or country. Thus we describe a method of partitioning a database of spatial data, the database including a plurality of spatial feature objections, the method comprising: reading data from said database grid cell-by-grid cell, a said grid cell comprising a cell of a grid spatially subdividing a region of spatial coverage of said database, each said grid cell including spatial feature objects; and determining a set of spatial partitions for said database, each grid cell being allocated to a said partition, responsive to a number of said spatial feature objects in each said grid cell.