Suppose a fact row has an unknown dim keys, do you load that row or not? Can you explain the advantage/disadvantages?
We need to load that row so that the total of the measure/fact is correct. To enable us to load the row, we need to either set the unknown dim key to 0 or the dim key of the newly created dim rows.
We can also not load that row (so the total of the measure will be different from the source system) if the business requirement prefer it. In this case we load the fact row to a quarantine area complete with error processing, DQ indicator and audit log. On the next day, after we receive the dim row, we load the fact row. This is commonly known as Late Arriving Dimension Rows and there are many sources for further information; .