Looking at http://www.postgresql.org/docs/devel/static/protocol-replication.html under START_REPLICATION it goes
""" The payload of each CopyData message from server to the client contains a message of one of the following formats: If a slot's name is provided via slotname, it will be updated as replication progresses so that the server knows which WAL segments - and if hot_standby_feedback is on which transactions - are still needed by the standby. XLogData (B) ... Primary keepalive message (B) ... """ That second paragraph was inserted recently and doesn't make sense there. It should be moved somewhere else. More generally, it is weird that the message formats are described there, even though the rest of the protocol documentation only mentions the messages by name and then describes the formats later (http://www.postgresql.org/docs/devel/static/protocol-message-types.html and http://www.postgresql.org/docs/devel/static/protocol-message-formats.html). For example, the meaning of the "(B)" code isn't described until two sections later. I think the description of the details of the these messages should also be moved there. The CopyBothResponse, which is also used for replication only, is also listed among the "normal" message formats. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers