drop table if exists load; create table load ( time timestamp without time zone not null, note text ); insert into load (time, note) values ('2016-11-02 01:00:01', 'first'), ('2016-11-02 02:00:02', 'first'), ('2016-11-02 03:00:03', 'first'), ('2016-11-02 04:00:04', 'first'), ('2016-11-02 04:00:05.111001', 'first'), ('2016-11-02 04:00:05.222002', 'first'), ('2016-11-02 04:00:05.333003', 'first');