Which action ensures the destination table matches the external data schema when copying data with a changing schema?

• A. Overwrite
• B. Append
• C. Merge
• D. Update

Answer: (A)

When copying data where the schema can change, you want the destination to reflect the current structure of the external data. Overwriting does this by recreating the destination table from the source, so its schema matches the external data exactly and the data aligns with that schema. Appending would keep the existing schema and just add rows, which can leave the destination out of sync if new or removed columns exist. Merging tries to combine with the existing table and often depends on field alignment, which may not fully harmonize the schemas. Updating changes only the data values without altering the schema, so it won’t synchronize structural changes. Note that overwriting will remove existing data and structure, so this approach is best when you’re comfortable replacing the destination with the current external schema.