A team wants to update or delete target rows that have no matching source row, but only for a recent time window so the whole table is not rewritten. Which MERGE feature should they use?

Question

Accepted Answer

A. WHEN NOT MATCHED BY SOURCE with a condition. WHEN NOT MATCHED BY SOURCE supports conditional UPDATE or DELETE logic for target rows with no matching source row, and Databricks recommends using a condition to avoid fully rewriting the table. Option b is wrong because UPDATE SET * applies only to matched rows, not unmatched target rows.

A team wants to update or delete target rows that have no matching source row, but only for a recent time window so the whole table is not rewritten. Which MERGE feature should they use?

Related Questions

Discussion