Exam Certified Data Engineer Professional topic 1 question 75 discussion

Merge, when not match insert

this question was in the Databricks DE Professional exam guide

Option C is tricky since it should be merge on on Not match condition rather than matching .. Since Option D is more suitable

To handle deduplication against previously processed records in a Delta table, the MERGE INTO command can be used to perform an upsert operation. This means that if the incoming data has a record that matches an existing record based on a unique key, the MERGE INTO operation can update the existing record (if needed) or simply ignore the duplicate. If there is no match (i.e., the record is new), then the record will be inserted

answer is C

Answer is C

merge will be more efficient

C Reference: file:///C:/Users/yuen1/Downloads/databricks-certified-data-engineer-professional-exam-guide.pdf