create table eventtracks (id integer default nextval('pk_eventtracks') primary key,
						  kb_id varchar(40) not null,
                          track_id varchar(40) not null,
                          sat_id varchar(40),
                          cause varchar(255),
                          unique(kb_id, track_id));
                            
create table eventslices (id integer default nextval('pk_eventslices') primary key,
                          track_id integer not null references eventtracks on delete cascade,
                          timestamp bigint not null,
                          status boolean,
                          certainty float,
                          severity int,
                          seaes varchar(3),
                          eems varchar(3),
                          sas varchar(3),
                          unique(track_id, timestamp));

create table measurands (id integer default nextval('pk_measurands') primary key,
						 slice_id integer not null references eventslices on delete cascade,
                         measurands varchar(15));