To Create a Feature of Type Polygon

Create the table with one geometry column and one ID.
CREATE TABLE PPOLYGON

(Id NUMBER PRIMARY KEY,

GEOMETRY MDSYS.SDO_GEOMETRY);
Insert the table metadata in the Oracle Spatial metadata.
INSERT INTO USER_SDO_GEOM_METADATA (TABLE_NAME, COLUMN_NAME, DIMINFO, SRID)

VALUES (‘POLYGON', 'GEOMETRY',

MDSYS.SDO_DIM_ARRAY

(MDSYS.SDO_DIM_ELEMENT('X', 714099.913898663, 715312.343907550, 0.000000050),

MDSYS.SDO_DIM_ELEMENT('Y', 4908438.586694972, 4910715.465519385, 0.000000050)),

82247);

COMMIT;
Create the spatial index of type multipolygon to use model multi-geometry objects.
CREATE INDEX Polygon_idx ON Polygon(Geometry)

INDEXTYPE IS MDSYS.SPATIAL_INDEX PARAMETERS ('layer_gtype=multipolygon');