The image shows a DBMS_PIPE Persistent Messaging Pipe basic workflow. There are three boxes. One the left: SEND_MESSAGE in Autonomous Database 1, with an arrow to the center box Cloud Pipe that contains Messages in Object Storage, and an arrow from the center to the right RECEIVE_MESSAGE area, on Autonomous Database 2.

On the left, Send Message includes the Session buffer, and the PACK_MESSAGE procedure (on Autonomous Database 1)

On the right, RECEIVE_MESSAGE includes Session_Buffer with UNPACK_MESSAGE (On Autonomous Database 2).