MySQL Manual
11 Spatial Extensions in MySQL
11.6 Optimising Spatial Analysis
It is known that search operations in non-spatial databases can be optimised using indexes. This is true for spatial databases as well. With the help of a great variety of multi-dimensional indexing methods that have already been designed, it's possible to optimise spatial searches. The most typical of these are:
- Point queries that search for all objects that contain a given point
- Region queries that search for all objects that overlap a given region
MySQL utilises R-Trees with quadratic splitting to index spatial columns. A spatial index is built using the MBR of a geometry. For most geometries, the MBR is a minimum rectangle that surrounds the geometries. For a horizontal or a vertical linestring, the MBR is a rectangle degenerated into the linestring. For a point, the MBR is a rectangle degenerated into the point.
