create extension if not exists timescaledb;

create table application_t (
  id serial not null primary key,
  label text not null unique,
  attributes jsonb
);

create table sensor_type_t (
  id serial not null primary key,
  label text not null unique,
  variable text not null,
  unit text not null,
  converter text not null,
  attributes jsonb
);

create table sensor_t (
  id serial not null primary key,
  label text not null,
  application int references application_t(id),
  sensor_type int references sensor_type_t(id),
  attributes jsonb,
  unique (label, application)
);

create table measurement_t (
  time timestamp without time zone not null,
  application text not null,
  sensor_type text not null,
  sensor text not null,
  variable text not null,
  unit text not null,
  value double precision not null,
  attributes jsonb
);

select create_hypertable('measurement_t', 'time');