Re: pg12 release notes

On Sat, May 11, 2019 at 03:06:40AM +0100, Andrew Gierth wrote:
> >>>>> "Bruce" == Bruce Momjian <bruce(at)momjian(dot)us> writes:
> Bruce> Do I need more?
>
> That isn't quite how I'd have worded it, but I'm not sure what the best
> wording is. Something like:
>
> * Output REAL and DOUBLE PRECISION values in shortest-exact format by
> default, and change the behavior of extra_float_digits
>
> Previously, float values were output rounded to 6 or 15 decimals by
> default, with the number of decimals adjusted by extra_float_digits.
> The previous rounding behavior is no longer the default, and is now
> done only if extra_float_digits is set to zero or less; if the value
> is greater than zero (which it is by default), a shortest-precise
> representation is output (for a substantial performance improvement).
> This representation preserves the exact binary value when correctly
> read back in, even though the trailing digits will usually differ
> from the output generated by previous versions when
> extra_float_digits=3.
>
> But I'm not 100% happy with this wording and am entirely open to
> suggestions for improvement.

I went with this paragraph:

This dramatically speeds up processing of floating-point values but
causes additional trailing digits to potentially be displayed. Users
wishing to have output that is rounded to match the previous behavior
can set <literal>extra_float_digits=0</literal>, which is no longer the
default.

Improvements?

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

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