Re: Correct documentation for protocol version

On 2025/04/10 18:52, Dave Cramer wrote:
> Greetings,
>
> The current docs say that if a client asks for a protocol that the backend doesn't support, it will return the newest minor version. https://www.postgresql.org/docs/current/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION <https://www.postgresql.org/docs/current/protocol-message-formats.html#PROTOCOL-MESSAGE-FORMATS-NEGOTIATEPROTOCOLVERSION>
>
> However that isn't what it returns. It actually returns the entire newest protocol that it supports. Attached is a patch to fix the docs.

As far as I read the code, the server returns the protocol version requested by
the client if it's less than or equal to the latest version the server supports.
Otherwise, it returns the latest supported version. So the proposed description
doesn't seem accurate either, does it?

+ Major is in the upper 16 bits and the lower in the low 16 bits.

To match the style of similar descriptions, how about rephrasing it as:
"The most significant 16 bits are the major version number, and the least
significant 16 bits are the minor version number”?

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION