To define an update strategy, complete the following steps:
To control how rows are flagged for insert, update, delete, or reject within a mapping, add an Update Strategy transformation to the mapping. Use an Update Strategy transformation to flag rows destined for the same target for different database operations, or to reject rows.
Define insert, update, and delete options for individual targets when you configure the mapping. On a target-by-target basis, you can allow or disallow inserts and deletes for all rows flagged for insert or delete. You can choose different ways to handle updates for all rows flagged for update.
If the mapping runs on the Spark run-time engine, you can choose Use Hive Merge in Update Strategy transformation advanced properties. When a query uses a MERGE statement instead of INSERT, UPDATE or DELETE statements, processing is usually more efficient.