For scenario 2 (overwrite the existing value in the latest row), which Slowly Changing Dimension type is appropriate?

For scenario 2 (overwrite the existing value in the latest row), which Slowly Changing Dimension type is appropriate?

• A. Type 3
• B. Type 1
• C. Type 0
• D. Type 2

Answer: (B)

When you want to update a dimension row by replacing its current value and not keep historical versions, you use Type 1. This approach updates the value in place and does not preserve prior values, so the row always reflects the latest state. It’s the right choice when historical changes aren’t needed for analysis or auditing, and only the current data matters. If you later need to track how values changed over time, you’d move to a design that preserves history, like Type 2 (which creates a new versioned row) or Type 3 (which stores a previous value in another column for limited history). Type 0 would not allow changes at all, so it wouldn’t meet the scenario’s need to overwrite.

When you want to update a dimension row by replacing its current value and not keep historical versions, you use Type 1. This approach updates the value in place and does not preserve prior values, so the row always reflects the latest state. It’s the right choice when historical changes aren’t needed for analysis or auditing, and only the current data matters. If you later need to track how values changed over time, you’d move to a design that preserves history, like Type 2 (which creates a new versioned row) or Type 3 (which stores a previous value in another column for limited history). Type 0 would not allow changes at all, so it wouldn’t meet the scenario’s need to overwrite.