You have a special type of point, an oriented point as defined in https://docs.oracle.com/cd/E11882_01/appdev.112/e11830/sdo_objrelschema.htm#SPATL533
2.7.6 Oriented Point
An oriented point is a special type of point geometry that includes
coordinates representing the locations of the point and a virtual end
point, to indicate an orientation vector that can be used for rotating
a symbol at the point or extending a label from the point. The main
use for an oriented point is in map visualization and display
applications that include symbols, such as a shield symbol to indicate
To specify an oriented point:
Use an SDO_GTYPE value (explained in Section 2.2.1) for a point or multipoint geometry.
Specify a null value for the SDO_POINT attribute.
In the SDO_ELEM_INFO array (explained in Section 2.2.4), specify an additional triplet, with the second and third values (SDO_ETYPE and
SDO_INTERPRETATION) as 1 and 0. For example, a triplet of 3,1,0
indicates that the point is an oriented point, with the third number
in the SDO_ORDINATES array being the first coordinate, or x-axis
value, of the end point reflecting the orientation vector for any
symbol or label.
In the SDO_ORDINATES array (explained in Section 2.2.5), specify the coordinates of the end point for the orientation vector from the
point, with values between -1 and 1. The orientation start point is
assumed to be (0,0), and it is translated to the location of the
physical point to which it corresponds.
Your geometry really has two vertices. The first one is the "real" vertex and the second one is the virtual end point.
There are two places where you can recognize this with bare eyes:
Normal 2D points (code 2001) have
Also oriented point has four numbers in MDSYS.SDO_ORDINATE_ARRAY while a normal 2D point has only two.