Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternativehosts when some errors occur

On Thu, May 18, 2017 at 5:05 PM, Tsunakawa, Takayuki
<tsunakawa.takay@jp.fujitsu.com> wrote:
> So, how about trying connection to the next host when the class code is neither 28, 3D, nor 42?
>
> Honestly, I'm not happy with this approach, for a maintenance reason that others are worried about.  Besides, when
theconnection target is not postgres and returns invalid data, no SQLSTATE is available.  I'm sorry to repeat myself,
butI believe PgJDBC's approach is practically good.  If you think the SQLSTATE is the only way to go, I will put up
withit.  It would be disappointing if nothing is done. 

FWIW, I am of the opinion to not have an implementation based on any
SQLSTATE codes, as well as not doing something similar to JDBC.
Keeping things simple is one reason, a second is that the approach
taken by libpq is correct at its root.
--
Michael