In ODB 2.2.29, to remove any field from a vertex, it’s possible to use this SQL:
UPDATE table REMOVE field
But this does not work for an edge reference field (the field that appears after the vertex has been linked to an edge). Even after deleting the edge and dropping the edge class, the edge reference field remains in the vertexes. Is there any way to remove it (other than dropping and recreating the vertex class)?