Re: Replication vs. float timestamps is a disaster

On Mon, Feb 20, 2017 at 11:58:12AM +0100, Petr Jelinek wrote:
> On 20/02/17 08:03, Andres Freund wrote:
> > On 2017-02-19 10:49:29 -0500, Tom Lane wrote:
> >> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> >>> On Sun, Feb 19, 2017 at 3:31 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >>>> Thoughts? Should we double down on trying to make this work according
> >>>> to the "all integer timestamps" protocol specs, or cut our losses and
> >>>> change the specs?
> >>
> >>> I vote for doubling down. It's bad enough that we have so many
> >>> internal details that depend on this setting; letting that cascade
> >>> into the wire protocol seems like it's just letting the chaos spread
> >>> farther and wider.
> >>
> >> How do you figure that it's not embedded in the wire protocol already?
> >> Not only the replicated data for a timestamp column, but also the
> >> client-visible binary I/O format, depend on this. I think having some
> >> parts of the protocol use a different timestamp format than other parts
> >> is simply weird, and as this exercise has shown, it's bug-prone as all
> >> get out.
> >
> > I don't think it's that closely tied together atm. Things like
> > pg_basebackup, pg_receivexlog etc should work, without having to match
> > timestamp storage. Logical replication, unless your output plugin dumps
> > data in binary / "raw" output, also works just fine across the timestamp
> > divide.
> >
> > It doesn't sound that hard to add a SystemToIntTimestamp() function,
> > given it only needs to do something if float timestamps are enabled?
> >
>
> It's definitely not hard, we already have
> IntegerTimestampToTimestampTz() which does the opposite conversion anyway.
>
> That being said, I did wonder myself if we should just deprecate float
> timestamps as well.

+1 for deprecating them. If we need a timestamp(tz) with a wider
range, we are getting options we didn't have before for implementing
it.

Best,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
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