GIS Features

Basic information about the existing spatial features can be found in theGeographic Features section of the Knowlegebase. The Spatial Extensions page of the MySQL manual also applies to MariaDB.

The MariaDB 5.3.3 release , contains code improving the spatial functionality in MariaDB.

MySQL operates on spatial data based on the OpenGIS standards, particularly theOpenGIS SFS (Simple feature access, SQL option).

Initial support was based on version 05-134 of the standard. MariaDB implements a subset of the 'SQL with Geometry Types' environment proposed by the OGC. And the SQL environment was extended with a set of geometry types.

MariaDB supports spatial extensions to operate on spatial features. These features are available for Aria, MyISAM, InnoDB, NDB, and ARCHIVE tables.

For spatial columns, Aria and MyISAM supports both SPATIAL and non-SPATIAL indexes. Other storage engines support non-SPATIAL indexes.

The most recent changes in the code are aimed at meeting the OpenGIS requirements. One thing missed in previous versions is that the functions which check spatial relations didn't consider the actual shape of an object, instead they operate only on their bounding rectangles. These legacy functions have been left as they are and new, properly-working functions are named with an 'ST_' prefix, in accordance with the latest OpenGIS requirements. Also, operations over geometry features were added.

The list of new functions:

Spatial operators. They produce new geometries.

Name	Description
Name	Description
ST_UNION(A, B)	union of A and B
ST_INTERSECTION(A, B)	intersection of A and B
ST_SYMDIFFERENCE(A, B)	symdifference, notintersecting parts of A and B
ST_BUFFER(A, radius)	returns the shape of the area that lies in 'radius' distance from the shape A.

Predicates, return boolean result of the relationship

Name	Description
Name	Description
ST_INTERSECTS(A, B)	if A and B have an intersection
ST_CROSSES(A, B)	if A and B cross
ST_EQUALS(A, B)	if A and B are equal
ST_WITHIN(A, B)	if A lies within B
ST_CONTAINS(A,B)	if B lies within A
ST_DISJOINT(A,B)	if A and B have no intersection
ST_TOUCHES(A,B)	if A touches B

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