On Sun, Sep 15, 2013 at 8:05 PM, Jeff Janes <jeff.janes@gmail.com> wrote:
> But note that the current behavior is worse in this regard. If you specify
> a scale of 4 at the column level, than it is not possible to distinguish
> between 5.000 and 5.0000 on a per-value basis within that column. If the
> scale at the column level was taken as the maximum scale, not the only
> allowed one, then that distinction could be recorded. That behavior seems
> more sensible to me (metrologically speaking, regardless of alter table
> performance aspects), but I don't see how to get there from here with
> acceptable compatibility breakage.
I think I'd probably agree with that in a green field, but as you say,
I can't see accepting the backward compatibility break at this point.
After all, you can get variable-precision in a single column by
declaring it as unqualified numeric.
--
Robert Haas
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