K Nearest Neighbors(KNN) query is one of the most useful geospatial operations, which targets to solve problems like “What are the 10 nearest taxi trip pickup points of New York Time Square?”. The underlying algorithm is straightforward, including compute the distances between query location and spatial objects, sorting objects by the distances and return the top-k. One typical input format of geospatial data is CSV, thus a csv parser to extract spatial object is necessary in the design.