Re: [HACKERS] Insert result does not match record count

From: Bruce Momjian <bruce(at)momjian(dot)us>
To: Andres Freund <andres(at)2ndquadrant(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Vik Fearing <vik(dot)fearing(at)dalibo(dot)com>, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, Natalie Wenz <nataliewenz(at)ebureau(dot)com>, "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org>, PG Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [HACKERS] Insert result does not match record count
Date: 2014-01-31 17:19:18
Message-ID: 20140131171918.GG19957@momjian.us
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On Wed, Jul 24, 2013 at 08:08:32PM +0200, Andres Freund wrote:
> On 2013-07-24 13:48:23 -0400, Tom Lane wrote:
> > Vik Fearing <vik(dot)fearing(at)dalibo(dot)com> writes:
> > > Also worth mentioning is bug #7766.
> > > http://www.postgresql.org/message-id/E1Tlli5-0007tR-HO@wrigleys.postgresql.org
> >
> > Yeah, did you read that whole thread? The real issue here is going to
> > be whether client-side code falls over on wider-than-32-bit counts.
> > We can fix the backend and be pretty sure that we've found all the
> > relevant places inside it, but we'll just be exporting the issue.
>
> > I did look at libpq and noted that it doesn't seem to have any internal
> > problem, because it returns the count to callers as a string (!).
> > But what do you think are the odds that callers are using code that
> > won't overflow? I'd bet on finding atoi() or suchlike in a lot of
> > callers. Even if they thought to use strtoul(), unsigned long is
> > not necessarily 64 bits wide.
>
> Application code that relies on the values already has problems though
> since the returned values are pretty bogus now. Including the fact that
> it can return 0 as the number of modified rows which is checked for more
> frequently than the actual number IME...
> So I think client code that uses simplistic stuff like atoi isn't worse
> off afterwards since the values will be about as bogus. I am more
> worried about code that does range checks like java's string conversion
> routines...
>
> I think fixing this for 9.4 is fine, but due to the compat issues I
> think it's to late for 9.3.

Where are we on this? There was a posted patch, attached, but Vik
Fearing said it was insufficent and he was working on a new one:

http://www.postgresql.org/message-id/51EFF67A.7020509@dalibo.com

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ Everyone has their own god. +

Attachment Content-Type Size
completion_tag_64.patch text/x-diff 3.0 KB

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