(mysql.info) optimizing-spatial-analysis

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(mysql.info) analysing-spatial-information

(mysql.info) spatial-extensions

(mysql.info) mysql-gis-conformance-and-compatibility

 
 16.6 Optimizing Spatial Analysis
 ================================
 

Menu

 
* creating-spatial-indexes     Creating Spatial Indexes
* using-a-spatial-index        Using a Spatial Index
 
 Search operations in non-spatial databases can be optimized using
 indexes. This is true for spatial databases as well. With the help of a
 great variety of multi-dimensional indexing methods that have
 previously been designed, it is possible to optimize 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 uses *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.
 
 It is also possible to create normal indexes on spatial columns.
 Beginning with MySQL 5.0.16, you must declare a prefix for any
 (non-spatial) index on a spatial column excepting `POINT' columns.
 

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(mysql.info) analysing-spatial-information

(mysql.info) spatial-extensions

(mysql.info) mysql-gis-conformance-and-compatibility