Re: protocol-level wait-for-LSN

Hi Peter,

On 10/28/24 12:58 PM, Heikki Linnakangas wrote:
> I'd suggest adding a new message type for this, so that it works the 
> same with simple and extended query. Or if you just want to wait without 
> issuing any query.

I agree it is a good idea to have a feature like this.

However, I agree with Heikki that we should have a separate message type 
for this. There are a lot of protocol implementations outside of 
PostgreSQL/Core, and they would have to adjust based on the version 
number of Core itself if we add fields to existing message types.

Maybe there should be an "Extension ('x') (F)" message that only has a 
fixed "header", and the rest of the fields are based on the "header" 
limited by the message length field - sort of free-form. The result is 
returned as a "DataRow ('D') (B)" list.

Thanks for working on this !

Best regards,
  Jesper