Re: [HACKERS] regressin failure on latest CVS

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: ohp(at)pyrenet(dot)fr
Cc: Rocco Altier <RoccoA(at)Routescape(dot)com>, Michael Glaesemann <grzm(at)myrealbox(dot)com>, pgsql-patches(at)postgresql(dot)org, pgsql-hackers(at)postgresql(dot)org
Subject: Re: [HACKERS] regressin failure on latest CVS
Date: 2005-07-23 15:36:43
Message-ID: 200507231536.j6NFahU00681@candle.pha.pa.us
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ohp(at)pyrenet(dot)fr wrote:
> I just checked latest CVS (5 mn ago) the problem is still the same,
> BTW, this is on Unixware 714 and no --enable-integer-datetime

Do you have the latest patch included int that version of CVS?
Anonymous CVS has a delay, and what was the problem you were seeing, the
rounding or the day - 1 result?

---------------------------------------------------------------------------

>
> Regards
> On Sat, 23 Jul 2005, Rocco Altier wrote:
>
> > Date: Sat, 23 Jul 2005 11:15:44 -0400
> > From: Rocco Altier <RoccoA(at)Routescape(dot)com>
> > To: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
> > Cc: Michael Glaesemann <grzm(at)myrealbox(dot)com>, pgsql-patches(at)postgresql(dot)org,
> > pgsql-hackers(at)postgresql(dot)org, ohp(at)pyrenet(dot)fr
> > Subject: RE: [HACKERS] regressin failure on latest CVS
> >
> > This still does not fix the problem.
> >
> > I had done my patch to try to mimic the way 8.0 had handled the math
> > with the remainders, but to carry it over another bucket (day).
> >
> > The problem that I see is that we are taking day_remainder and
> > multiplying by USECS_PER_DAY. Which is a double * int64, thus there is
> > the precision loss there.
> >
> > I think initial division by the factor can't be helped, but repeatedly
> > doing more floating point math on with it is causing the rounding error.
> >
> > Thanks,
> > -rocco
> >
> > > -----Original Message-----
> > > From: Bruce Momjian [mailto:pgman(at)candle(dot)pha(dot)pa(dot)us]
> > > Sent: Saturday, July 23, 2005 10:54 AM
> > > To: Rocco Altier
> > > Cc: Michael Glaesemann; pgsql-patches(at)postgresql(dot)org;
> > > pgsql-hackers(at)postgresql(dot)org; ohp(at)pyrenet(dot)fr
> > > Subject: Re: [HACKERS] regressin failure on latest CVS
> > >
> > >
> > > Rocco Altier wrote:
> > > > This patch fixes the interval regression on my AIX box
> > > (kookaburra) by
> > > > only doing integer math on the interval, instead of
> > > float/double math.
> > > >
> > > > I think this is the correct way to handle this, since it's
> > > an integer
> > > > data type.
> > > >
> > > > I don't know if it will fix Olivier's problem, since I
> > > wasn't able to
> > > > reproduce it.
> > > >
> > >
> > > I have changed the way I compute the remainder values --- instead of
> > > using multiplication, I use division and then subtraction.
> > > This should
> > > fix your rounding problem. Looking at your fix, I don't see
> > > how adding
> > > USECS changes things because the factor is already a float,
> > > but I think
> > > the problem was more the way I was computing the remainders.
> > >
> > > Patch attached --- let me know if it does not fix your problem.
> > >
> > > --------------------------------------------------------------
> >
> >
> >
>
> --
> Olivier PRENANT Tel: +33-5-61-50-97-00 (Work)
> 15, Chemin des Monges +33-5-61-50-97-01 (Fax)
> 31190 AUTERIVE +33-6-07-63-80-64 (GSM)
> FRANCE Email: ohp(at)pyrenet(dot)fr
> ------------------------------------------------------------------------------
> Make your life a dream, make your dream a reality. (St Exupery)
>
> ---------------------------(end of broadcast)---------------------------
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>

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
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