Question 40
Domain 10: Data ModellingA customer dimension must preserve the full history of status changes with effective dates and a current flag. Which modeling pattern fits best?
Correct answer: A
Explanation
A Type 2 slowly changing dimension preserves history by creating a new row for each status change, so prior values remain available. It also supports effective dates and a current flag, which identify when each version is valid and which row is active now.
Why each option is right or wrong
A. Type 2 slowly changing dimension
A Type 2 slowly changing dimension is the standard dimensional-modeling pattern used when every status change must be retained as a separate versioned row. Each change inserts a new record with its own effective start and end dates, and a current-row indicator is typically maintained as a 1/0 flag so the active version can be identified without losing prior history.
B. Type 1 overwrite
Type 1 replaces old values, so prior status history and effective dating are lost.
C. A temporary view with no persisted history
A temporary view can present data but does not persist dimension history for analysis.
D. A streaming backlog alert
A streaming backlog alert is an operational monitoring concept, not a dimensional modeling pattern.