(mysql.info.gz) Optimizing spatial analysis
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(mysql.info.gz) Analysing spatial information
(mysql.info.gz) Spatial extensions in MySQL
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18.6 Optimizing Spatial Analysis
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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.
Menu
* Creating spatial indexes Creating Spatial Indexes
* Using a spatial index Using a Spatial Index
Info Catalog
(mysql.info.gz) Analysing spatial information
(mysql.info.gz) Spatial extensions in MySQL
(mysql.info.gz) MySQL GIS conformance and compatibility
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