Re: Snapshot too old logging

On Tue, Nov 15, 2016 at 8:22 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Tue, Nov 15, 2016 at 2:21 PM, Kevin Grittner <kgrittn(at)gmail(dot)com> wrote:
> > On Tue, Nov 15, 2016 at 12:43 PM, Robert Haas <robertmhaas(at)gmail(dot)com>
> wrote:
> >
> >> I think it would be better not to include either the snapshot or the
> >> block number, and just find some way to reword the error message so
> >> that it mentions which relation was involved without implying that all
> >> access to the relation would necessarily fail. For example:
> >>
> >> ERROR: snapshot too old
> >> DETAIL: One or more rows required by this query have already been
> >> removed from "%s".
> >
> > That particular language would be misleading. All we know about
> > the page is that it was modified since the referencing (old)
> > snapshot was taken. We don't don't know in what way it was
> > modified, so we must assume that it *might* have been pruned of
> > rows that the snapshot should still be able to see.
>
> Oh, yeah. So maybe "may have already been removed".
>

Just to be clear, you're suggesting 'One or more rows may have already been
removed from "%s"?

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Magnus Hagander
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