Which description matches Slowly Changing Dimensions Type 1?

• A. Preserves history by creating new rows.
• B. Overwrites old data with new values.
• C. Stores limited history in separate attributes.
• D. Deletes old values when updated.

Answer: (B)

Type 1 changes focus on updating the existing value in place, so no history is kept. When a attribute value changes, the old value is overwritten in the same row, leaving only the current state. This is exactly why the description matches: it describes replacing old data with new values rather than creating new rows to preserve history. It’s not about preserving history (that would be a Type 2 approach), nor about storing limited history in separate attributes (Type 3), and it doesn’t imply deleting values as a separate action—the old value is simply replaced.