Re: Let's drop V2 protocol

Marko Kreen <markokr(at)gmail(dot)com> writes:
> On Fri, Feb 24, 2012 at 4:26 PM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
>> I think it's plausible that very old client libraries could connect to
>> a modern server. But it's pretty unlikely to have a 9.2 app contact
>> an ancient server IMO.

> We can drop it from libpq but keep the server-side support,
> the codebase is different.

I believe it's still somewhat common among JDBC users to force
V2-protocol connections as a workaround for over-eager prepared
statement planning. Although I think the issue they're trying to dodge
will be fixed as of 9.2, that doesn't mean the server-side support can
go away.

As for taking it out of libpq, I would vote against doing that as long
as we have pg_dump support for pre-7.4 servers. Now, I think it would
be entirely reasonable to kill pg_dump's support for pre-7.3 servers,
because that would simplify life in numerous ways for pg_dump; but 7.4
was not a big compatibility break for pg_dump so it seems a bit
arbitrary to kill its support for 7.3 specifically.

As near as I can tell the argument here is basically that we don't want
to try to fix unfixable bugs in the V2-protocol code. Well, yeah,
they're unfixable ... why do you think we invented V3? But they are
what they are, and as long as you don't run into those limitations the
protocol does still work. There are plenty of features that require V3
already, so I see no reason not to classify the row-processor stuff as
one more.

regards, tom lane