Re: let's make the list of reportable GUCs configurable (was Re: Add %r substitution for psql prompts to show recovery status)

"Joshua D. Drake" <jd@commandprompt.com> writes:
> On 01/10/2018 09:22 AM, Tom Lane wrote:
>> ... but I don't think it fixes that, because you couldn't send this new
>> request without making an assumption about the server version being
>> new enough to support it.  My entire beef with making server_version_num
>> be GUC_REPORT is that it would encourage people to write client code that
>> fails outright against older servers.  I'm afraid what you are suggesting
>> will be an equally attractive nuisance.

> It seems to me that is not our problem. Why do we care if some developer 
> says, "I only work with 9.6"? If I am understanding your complaint.

I don't care at all if J. Random Developer's homegrown code only works
with the PG version he's using.  The concern I have is that unwanted
server version dependencies will sneak into widely used code, like
psql, or libpq, or jdbc.  Or another way of putting it: Robert's proposal
is a protocol version break, just like most stuff at this level.  Trying
to pretend it isn't doesn't make it not one.

            regards, tom lane