if (joinType.UNION() != null) {
throw new RuntimeException("UNION JOIN is not supported");// TODO
} else {
checkNotNull(joinType.outerJoinType());
if (joinType.outerJoinType().LEFT() != null) {
rel = r1.relation().leftOuterJoin(r2.relation(), pcode, pIsEq);
} else if (joinType.outerJoinType().RIGHT() != null) {
rel = r1.relation().rightOuterJoin(r2.relation(), pcode, pIsEq);
} else {
checkNotNull(joinType.outerJoinType().FULL());
rel = r1.relation().fullOuterJoin(r2.relation(), pcode, pIsEq);