The point-in-time join associates a fact with the version of the dimension that was valid at the time of the event, by comparing the fact's date with the validity interval of an SCD type 2. It ensures that historical analyses reflect the reality of the time and not the current state.
Example
JOIN dim_client c ON f.id_client = c.id_client AND f.date_vente >= c.valide_du AND f.date_vente < c.valide_au