Managed OpenSearch Data metering
All network traffic (both inbound and outbound) for Managed Databases is unmetered. Database plans do not include a transfer quota and do not contribute to the user's public network fair transfer limit.
However, when a Cloud Server connects to a Managed Database, the server's network usage is metered and counts toward the user's public network fair transfer limit.
Data transfer via the Utility network is always free of charge.