distinguish peloton and postgres jointype
distinguish peloton and postgres jointype


Former-commit-id: 27e0cf373565d63c0cdd0ea98fd35bf9eb3d9a7b
amaliujia/CMUDB-peloton,omegaga/peloton,larryxiao/peloton-1,ranxian/peloton,omegaga/peloton,omegaga/peloton,larryxiao/peloton-1,larryxiao/peloton,larryxiao/peloton-1,amaliujia/CMUDB-peloton,omegaga/peloton,omegaga/peloton,ranxian/peloton,larryxiao/peloton-1,amaliujia/CMUDB-peloton,ranxian/peloton,larryxiao/peloton,larryxiao/peloton,amaliujia/CMUDB-peloton,larryxiao/peloton,larryxiao/peloton,larryxiao/peloton-1,ranxian/peloton,larryxiao/peloton,omegaga/peloton,ranxian/peloton,omegaga/peloton,amaliujia/CMUDB-peloton,larryxiao/peloton-1,amaliujia/CMUDB-peloton,larryxiao/peloton-1,larryxiao/peloton,amaliujia/CMUDB-peloton,ranxian/peloton