From: Tom Lane <tgl@sss.pgh.pa.us>
To: Michael Paquier <michael@paquier.xyz>
cc: Alvaro Herrera <alvherre@2ndquadrant.com>,
        Andres Freund <andres@anarazel.de>,
        Dilip Kumar <dilipbalaut@gmail.com>, jungleboogie0@gmail.com,
        pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #15964: vacuumdb.c:187:10: error: use of undeclared
 identifier 'FD_SETSIZE'
In-reply-to: <20190819042832.GA1702@paquier.xyz>
References: <20190818001858.ho3ev4z57fqhs7a5@alap3.anarazel.de>
 <20190819025953.GA15110@alvherre.pgsql> <20190819042832.GA1702@paquier.xyz>
Comments: In-reply-to Michael Paquier <michael@paquier.xyz>
	message dated "Mon, 19 Aug 2019 13:28:32 +0900"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <23513.1566189171.1@sss.pgh.pa.us>
Date: Mon, 19 Aug 2019 00:32:51 -0400
Message-ID: <23514.1566189171@sss.pgh.pa.us>
Precedence: bulk

Michael Paquier <michael@paquier.xyz> writes:
> On Sun, Aug 18, 2019 at 10:59:54PM -0400, Alvaro Herrera wrote:
>> So I agree that we need a fix.

> How would you detect how many fds can be opened by a user in this
> case?

I think Andres' suggestion is probably fine: don't try to detect
it in advance.  Just open the files, and error out if we need to
put an fd index >= FD_SETSIZE into an fd_set.  It'll be a shade
less user-friendly, in that the program might run for a bit before
failing; but I doubt that such cases arise often enough to be worth
working harder.

			regards, tom lane