Horton

Re: PG 12 draft release notes

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Andrew Gierth <andrew@tao11.riddles.org.uk>
Cc: Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-05-21T20:28:02Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. doc: PG 12 relnotes: update wording on truncate/vacuum item

  2. docs: PG 12 relnotes, update btree items

  3. doc: PG 12 relnotes, list added snowball/FTS languages

  4. doc: PG 12 relnotes, merge new SQL partition function items

  5. docs: PG 12 release notes, support functions

  6. docs: PG 12 relnote adjustments based on feedback from Tom Lane

  7. docs: adjust RECORD PG 12 relnote item

  8. doc: adjust PG 12 relnotes item on float digit adjustment

  9. doc: adjustments for PG 12 release notes

  10. docs: fix duplicate wording in PG 12 release notes

  11. doc: properly attibute PG 12 pgbench release note item

  12. doc: PG 12 release notes: normalize attribution names

  13. Refactor the fsync queue for wider use.

  14. Add "split after new tuple" nbtree optimization.

  15. Add nbtree high key "continuescan" optimization.

  16. Allow amcheck to re-find tuples using new search.

  17. Consider secondary factors during nbtree splits.

  18. Partial implementation of SQL/JSON path language

  19. Allow extensions to generate lossy index conditions.

  20. Make TupleTableSlots extensible, finish split of existing slot type.

  21. Reduce path length for locking leaf B-tree pages during insertion

On Tue, May 21, 2019 at 12:08:25AM +0100, Andrew Gierth wrote:
> >>>>> "Andres" == Andres Freund <andres@anarazel.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?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
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