From: Tom Lane <tgl@sss.pgh.pa.us>
To: Bruce Momjian <bruce@momjian.us>
cc: Oleksandr Shulgin <oleksandr.shulgin@zalando.de>,
        "David G. Johnston" <david.g.johnston@gmail.com>, exclusion@gmail.com,
        PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: BUG #16486: Prompted password is ignored when password specified
 in connection string
In-reply-to: <20200902131858.GD13613@momjian.us>
References: <16486-b9c93d71c02c4907@postgresql.org>
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Comments: In-reply-to Bruce Momjian <bruce@momjian.us>
	message dated "Wed, 02 Sep 2020 09:18:58 -0400"
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Date: Wed, 02 Sep 2020 10:46:19 -0400
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Bruce Momjian <bruce@momjian.us> writes:
> On Wed, Sep  2, 2020 at 09:54:37AM +0200, Oleksandr Shulgin wrote:
>> AFAIK, there is nothing in the protocol that forces psql to make an extra
>> connection attempt.  If libpq provided a means to pass a password-prompt
>> callback, no extra connection would be needed I think?

> That is true.  I don't think we want the backend to be kept open waiting
> for someone to type a password, which is why, I think, we don't do it
> that way.

Yeah, I think this is an ancient value judgement.  Sure, it's pretty
questionable whether spawning a backend a second time is better than
tying one up waiting for a human to type a password.  (It's going to
be spending a lot of time waiting for that human later on, anyway.)
The real point IMO is that libpq's connection API is already
unreasonably complicated, and providing a callback of this sort
would make it even messier.  A different client library might make
a different choice, perhaps.

			regards, tom lane