Amazon Relational Database Service (Amazon RDS) Database Activity Streams captures events from the database, encrypts them, and uploads the records to an Amazon Kinesis data stream within your account. The default behavior is that Database Activity Streams creates a Kinesis data stream in provisioned mode upon start. Starting today, once you enable Database Activity Streams, we will create a Kinesis data stream in on-demand mode instead of provisioned mode. This change will only apply to any new Database Activity Streams enablements. This will not affect existing Kinesis data streams. If you wish to move from on-demand mode to provisioned mode, you can do so through the Kinesis Console or APIs.
Source:: Amazon AWS