One of the defining characteristics of a spatial database is the ability to create special spatial indexes to speed up geometry-based searches. These indexes are used to perform spatial operations such as identifying all the features that lie within a given bounding box, identifying all the features within a certain distance of a given point, or identifying all the features that intersect with a given polygon.
A spatial index is defined in the same way as you define an ordinary database index, except that you add the
SPATIAL keyword to identify the index as a spatial index. For example:
CREATE TABLE cities ( id INTEGER AUTO_INCREMENT PRIMARY KEY, name CHAR(255), geom POLYGON NOT NULL, INDEX (name), SPATIAL INDEX (geom))
All three ...