Data engineering·Modelling for analysis
the order arrived before the customer record did, so the fact points at a placeholder row labelled unknown.
Late-arriving dimension
Also calledearly-arriving fact, unknown member
A fact whose dimension row does not exist yet at load time, usually because two source systems publish at different speeds. The standard handling is an inferred member — insert a stub dimension row keyed on the business key and fill in its attributes when the real record shows up. Doing nothing instead means either dropping the fact or breaking the join, and both are worse than a temporary unknown.