ABSTRACT
The genius of the fact, dimension, and summary table concepts is rendered more obvious in the presence of the Time Variant Solution Design. The performance degradation is resolved by the use of an Instance Key that uniquely identifies a single row of a dimension table. A query that begins with a fact table will join up to the dimension tables. More specifically, a query that begins with a row of data from a fact table will join up to a single row in a dimension table. Type 2 Time Variance is achieved by connecting every row of a fact table to the dimension rows that were in effect at the time of the transaction presented in that row. Type 1 Time Variance is achieved by connecting every row of a fact table to the dimension rows that are in effect right.
