Historised twin
Time travel
The state as it really was — reconstructed from the historian, not interpolated. An AAS server only answers “what is it like now”. After a fault, though, the question is what it was like back then, and the standard alone has no answer to that. Here every change is its own row in a TimescaleDB hypertable; nothing is ever overwritten.
No values exist for this point in time.
The query behind it is a DISTINCT ON (id_short_path) with observed_at <= cutoff, sorted descending — for each path the
most recent row up to that moment. That it works rests on a single design decision: in
this table nothing is overwritten, every measurement is a new row.