In a data warehouse, which scenario is the best example of a slowly changing dimension that does not retain history?

• A. An address from the customer table that is overwritten when changed
• B. A piece of historical customer data that is removed from the table
• C. A new table created each day with updated customer data
• D. An address from the customer table that is overwritten when changed

Answer: (A)

When a dimension attribute changes and you don’t keep the old value, you’re using a Type 1 slowly changing dimension. Overwriting the existing value in the dimension row means the previous value is lost and no history is retained. The address example fits this; when the address updates, the old address is replaced with the new one, so you don’t have a history of past addresses. This is exactly the behavior of a no-history SCD.

Other approaches would preserve history (like adding a new row for each change or keeping a separate history table) or simply purge data, but they don’t illustrate the no-history overwrite pattern.