Horton

Re: Postgres 11 release notes

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Tatsuo Ishii <ishii@sraoss.co.jp>
Cc: pgsql-hackers@postgresql.org
Date: 2018-05-15T19:37:10Z
Lists: pgsql-hackers 
On Tue, May 15, 2018 at 09:51:47AM +0900, Tatsuo Ishii wrote:
> >> I could not find this:
> >> 
> >> $ git log -1 f8e5f15
> >> commit f8e5f156b30efee5d0038b03e38735773abcb7ed
> >> Author: Andres Freund <andres@anarazel.de>
> >> Date:   Mon Sep 18 19:36:44 2017 -0700
> >> 
> >>     Rearm statement_timeout after each executed query.
> >>     
> >>     Previously statement_timeout, in the extended protocol, affected all
> >>     messages till a Sync message.  For clients that pipeline/batch query
> >>     execution that's problematic.
> >>     
> >>     Instead disable timeout after each Execute message, and enable, if
> >>     necessary, the timer in start_xact_command(). As that's done only for
> >>     Execute and not Parse / Bind, pipelining the latter two could still
> >>     cause undesirable timeouts. But a survey of protocol implementations
> >>     shows that all drivers issue Sync messages when preparing, and adding
> >>     timeout rearming to both is fairly expensive for the common parse /
> >>     bind / execute sequence.
> >>     
> >>     Author: Tatsuo Ishii, editorialized by Andres Freund
> >>     Reviewed-By: Takayuki Tsunakawa, Andres Freund
> >>     Discussion: https://postgr.es/m/20170222.115044.1665674502985097185.t-ishii@sraoss.co.jp
> > 
> > That seemed too detailed for the release notes.  Is that wrong?
> 
> This commit gives user-visible changes to the statment timeout
> behavior. So I think this should be added to the release notes.

OK, makes sense. Here is what I added:

	2017-09-18 [f8e5f156b] Rearm statement_timeout after each executed query.

        In the <link linkend="protocol-query-concepts">Extended Query
        Protocol</link>, have <varname>statement_timeout</varname> apply
        to each <literal>Execute</literal> message, not to all commands
        before <literal>Sync</literal> (Tatsuo Ishii)

-- 
  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. +
+                      Ancient Roman grave inscription +

Commits

  1. doc: update PG 11 release notes

  2. Fix misspelled pg_trgm contrib name in PostgreSQL 11 release notes

  3. Doc: clarify release note text about v11's new window function features.

  4. Improve wording of release notes item

  5. Fix typos in release notes

  6. Doc: preliminary list of PG11 major features.

  7. Make numeric power() handle NaNs according to the modern POSIX spec.

  8. Various improvements of skipping index scan during vacuum technics

  9. Revert back-branch changes in power()'s behavior for NaN inputs.

  10. Avoid wrong results for power() with NaN input on more platforms.

  11. Avoid wrong results for power() with NaN input on some platforms.

  12. Skip full index scan during cleanup of B-tree indexes when possible

  13. Rewrite the code that applies scan/join targets to paths.

  14. Postpone generate_gather_paths for topmost scan/join rel.

  15. Add casts from jsonb

  16. Make plpgsql use its DTYPE_REC code paths for composite-type variables.

  17. Don't allow VACUUM VERBOSE ANALYZE VERBOSE.

  18. Pass InitPlan values to workers via Gather (Merge).

  19. Account for the effect of lossy pages when costing bitmap scans.

  20. Allow no-op GiST support functions to be omitted.

  21. Rearm statement_timeout after each executed query.

  22. Push limit through subqueries to underlying sort, where possible.