In the SAP Cloud Integration Data Store "Write" operation, the "Overwrite Existing Message" parameter is specifically designed to manage how the system handles messages with an identical Entry ID. When this parameter is selected, if a message is written to the data store with an Entry ID that already exists, the new message will replace the old one. This action effectively prevents the creation of duplicate entries for the same key, ensuring data integrity and uniqueness within the data store based on the Entry ID.

B. Retention Threshold for Alerting: This parameter is used for monitoring purposes to trigger an alert if a message remains in the data store beyond a specified time, not for preventing duplicates.

C. Include Message Headers: This option determines whether to store the message headers along with the payload. It affects the content of the stored entry, not the duplicate handling logic.

D. Encrypted stored Message: This is a security feature that encrypts the message content at rest in the data store. It has no impact on how duplicate entries are managed.

1. SAP Help Portal

SAP Integration Suite: Defining a Data Store Operation. In the section describing the "Write" operation parameters

the documentation states: "Overwrite Existing Message: If you select this option

an existing entry in the data store is overwritten by a new entry with the same ID. If you don't select this option

the integration flow fails if an entry with the same ID already exists." This directly confirms that selecting this option is the method to avoid duplicates by overwriting. (Accessed under Cloud Integration -> Designing Integration Content -> Define Data Store Operations).