Date: Tue, 20 Aug 2019 19:07:49 -0700
From: Andres Freund <andres@anarazel.de>
To: Michael Paquier <michael@paquier.xyz>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alvaro Herrera <alvherre@2ndquadrant.com>,
	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'
Message-ID: <20190821020749.xtjw7xrtame74tao@alap3.anarazel.de>
References: <20190818001858.ho3ev4z57fqhs7a5@alap3.anarazel.de>
 <20190819025953.GA15110@alvherre.pgsql>
 <20190819042832.GA1702@paquier.xyz>
 <23514.1566189171@sss.pgh.pa.us>
 <20190819051251.GB18166@paquier.xyz>
 <20190820160553.37nd5jxs4dk2qujy@alap3.anarazel.de>
 <20190821015854.GD1684@paquier.xyz>
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Hi,

On 2019-08-21 10:58:54 +0900, Michael Paquier wrote:
> On Tue, Aug 20, 2019 at 09:05:53AM -0700, Andres Freund wrote:
> > I think the error message ought be reformulated, so users have a chance
> > to actually understand what they need to change to avoid the error. At
> > least something roughly like "too many jobs for this platform's select()".
> 
> pgbench needs an extra fix then?

Well, there the commandline option talks about clients? Whereas
vacuumdb/reindexdb talk about jobs, but the old message talked about
clients.  So no, I don't think it makes sense to adapt it the same way.


> > ISTM that we should fail in ParallelSlotsSetup(), rather than
> > ParallelSlotsGetIdle() though? That's always going to be earlier, and
> > there's no way to get into the problematic situation at a later point,
> > no?
> 
> Okay, done this way.  What do you think about the attached?
> --
> Michael

> @@ -246,6 +232,18 @@ ParallelSlotsSetup(const char *dbname, const char *host, const char *port,
>  		{
>  			conn = connectDatabase(dbname, host, port, username, prompt_password,
>  								   progname, echo, false, true);
> +
> +			/*
> +			 * Fail immediately if trying to use an index in an unsupported
> +			 * range.  Doing a hard exit here is not beautiful, but that's
> +			 * not worth complicating the logic.
> +			 */

"that's not worth" sounds odd to me in the above sentence. I don't quite
get the half-hearted rewrite of the comment from pgbench.c.


Greetings,

Andres Freund