OGC Definition

[OGC99-049] defines contains as:

A.Contains(B) iff B.Within(A). See Within .

Oracle Spatial Definition

[OSUGR] defines Contains as follows. "The interior and boundary of one object is completely contained in the interior of the other object." This is not the same as the OGC definition, and so the FDO Oracle Provider maps the OGC definition of contains to an OR'd combination of the Oracle contains and covers operators.

[OSUGR] defines covers as follows. "The interior of one object is completely contained in the interior or boundary of the other object and their boundaries intersect."

contains = contains+covers as used in the third argument to the sdo_relate spatial operator, for example,
sdo_relate(a.geometry, mdsys.sdo_geometry(2001, NULL, mdsys.sdo_point_type(1,1,NULL), NULL, NULL), 'mask=contains+covers').