Abstract: Methods, including computer programs encoded on a computer storage medium, for determining whether a spatial record is located within a polygon. In one aspect, a method includes: receiving data identifying a polygon positions on a coordinate system, identifying a plurality of lines to represent the polygon, accessing information that identifies a spatial record position at a location on the coordinate system using a spatial index that includes spatial data and non-spatial data, generating a ray that emanates from the spatial record and that is projected in a particular direction, determining whether the spatial record is located within the polygon based on a number of times that the ray intersects the plurality of lines, and outputting information that identifies whether the spatial record is located within the polygon.