Re: PG 12 draft release notes

On Tue, May 21, 2019 at 12:08:25AM +0100, Andrew Gierth wrote:
> >>>>> "Andres" == Andres Freund <andres(at)anarazel(dot)de> writes:
>
> Andres> Any chance for you to propose a text?
>
> This is what I posted before; I'm not 100% happy with it but it's still
> better than any of the other versions:
>
> * 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.

How is this?

<para>
Improve performance by changing the default number of trailing digits
output for <link linkend="datatype-float"><type>REAL</type></link>
and <type>DOUBLE PRECISION</type> values (Andrew Gierth)
</para>

<para>
Previously, float values were output rounded to 6 or 15 decimals
by default. Now, only the number of digits required to preserve
the exact binary value is output. The previous behavior can be
restored by setting <xref linkend="guc-extra-float-digits"> to zero.
</para>

Am I missing something?

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