How to do it...

KNN is an approach of searching for an arbitrary number of points closest to a given point. Without the right tools, this can be a very slow process that requires testing the distance between the point of interest and all the possible neighbors. The problem with this approach is that the search becomes exponentially slower with a greater number of points. Let's start with this naive approach and then improve on it.

Suppose we were interested in finding the 10 records closest to the geographic location -81.738624, 41.396679. The naive approach would be to transform this value into our local coordinate system and compare the distance to each point in the database from the search point, order those values by distance, and limit ...

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