### 12.14.9 Functions That Test Spatial Relations Between Geometry Objects

The functions described in this section take two geometries as
arguments and return a qualitative or quantitative relation
between them.

The OpenGIS specification defines the a set of functions that
test the relationship between two geometry values. MySQL
originally implemented these functions such that they used
object minimum bounding rectangles (MBRs) and returned the
same result as the corresponding MBR-based functions. For
example, `Contains()`

and
`MBRContains()`

return the same result.
(Exception: `Crosses()`

exists
but `MBRCrosses()`

does not.)

A MySQL-specific set of MBR-based functions is available to
test the relationship between two geometry values.