Re: Hot Standby and handling max_standby_delay

Tom Lane wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>> Simon Riggs wrote:
>>> Do we need a new record type for that, is there a handy record type to
>>> bounce from?
>
>> After starting streaming, slices of WAL are sent as CopyData messages.
>> The CopyData payload begins with an XLogRecPtr, followed by the WAL
>> data. That payload format needs to be extended with a 'message type'
>> field and a new message type for the timestamps need to be added.
>
> Whether or not anyone bothers with the timestamp message, I think adding
> a message type header is a Must Fix item. A protocol with no provision
> for extension is certainly going to bite us in the rear before long.

Agreed a message type header is a good idea, although we don't expect
streaming replication and the protocol to work across different major
versions anyway.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com