ObjRelationship artistExhibitToArtistRel = (ObjRelationship) artistExhibitEntity.getRelationship("toArtist");
artistExhibitEntity.removeRelationship("toArtist");
ObjRelationship exhibitToArtistExhibitRel = (ObjRelationship) exhibitEntity
.getRelationship("artistExhibitArray");
exhibitEntity.removeRelationship("artistExhibitArray");
Expression e = ExpressionFactory.matchExp("artistName", "artist1");
SelectQuery q = new SelectQuery("Artist", e);
q.addPrefetch("paintingArray");
q.addPrefetch("paintingArray.toGallery");