This note was published today. It may explain the questions I have been getting.
“The Standard Cost General table (W_STANDARD_COST_G) and the Exchange Rate General table (W_EXCH_RATE_G) are general reference tables.
Both tables have surrogate keys (ROW_WID). But unlike dimension surrogate keys, these surrogate keys are not referenced as foreign keys by any fact tables. Therefore the general tables do not participate in the star schema. They are not designed for use in reports and queries.
The general tables are intended for use as lookups during Extract-Transform-Load (ETL). For example, the Standard Cost General table provides cost information for a particular product in a particular inventory. The cost information will then be stored in the fact table directly. Similarly, the Exchange Rate General table provides the exchange rate between a pair of currencies for a specific day, given the exchange rate type.
The following are some WIDs in the general tables. They are not necessarily populated and they are not intended for use. These columns are:
If you need to have a cost dimension, you need to design a different table. It is not recommended that you alter the Standard Cost General table for this purpose. “