In the Data Warehouse practice of ETL, an early fact or early-arriving fact denotes the detection of a dimensional natural key during fact table source loading, prior to the assignment of a corresponding primary key or surrogate key in the dimension table. Hence, the fact which cites the dimension arrives early, relative to the definition of the dimension value.
Procedurally, an early fact can be treated as:
References
Early-arriving fact Wikipedia(Text) CC BY-SA