Horton

Re: Postgres 11 release notes

Michael Paquier <michael@paquier.xyz>

View thread View on postgr.es
From: Michael Paquier <michael@paquier.xyz>
To: Bruce Momjian <bruce@momjian.us>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-05-13T06:43:08Z
Lists: pgsql-hackers 
On Fri, May 11, 2018 at 11:08:52AM -0400, Bruce Momjian wrote:
> I have committed the first draft of the Postgres 11 release notes.  I
> will add more markup soon.  You can view the most current version
> here:

Thanks for gathering all the commits in one piece, Bruce.

> I expect a torrent of feedback.  ;-)

I looked at the entries where my name shows up.  Here is some feedback
with HEAD at 8c6227a2 (latest as of writing this message).

<para>
 Add information_schema columns related to table constraints and
 triggers (Michael Paquier)
</para>
The author of this entry is Peter Eisentraut, not me.

<para>
 Channel binding requires the server end
 of the <acronym>TLS</acronym> connection to
 prove that it knows the password.  The options are <link
 linkend="libpq-scram-channel-binding"><option>scram_channel_binding=tls-unique</option></link>
 and <option>scram_channel_binding=tls-server-end-point</option>.
</para>
This is not actually correct.  Channel binding is an MITM prevention
mechanism which makes sure that after the SSL handshake the backend and
the frontend are still connected to the same things.  "tls-unique" makes
sure that a connection is uniquely used using a hash of the TLS finish
 message, and end-point makes sure that the endpoints are the same using
 a hash of the server certificate.

<para>
 WHAT DOES THIS DOC TEXT MEAN?  "An empty value specifies that
 the client will not use channel binding.  The default value
 is tls-unique."
</para>
This means that the client can choose to not use channel binding (which
sends a 'n' flag if you refer to the communication protocol of SCRAM),
even if the server has advertised to the client channel binding.  So
this provides a way to disable the feature at will, an on/off switch if
you want.  If a v10 libpq tries to connect to a v11 server, then it
won't use channel binding automatically.  That may be worth adding to
the documentation as well.

<para>
 Allow access to file system functions to be controlled by
 <command>GRANT</command>/<command>REVOKE</command> permissions,
 rather than super-user checks (Michael Paquier)
</para>
Author is Stephen Frost here.

<para>
 Use <command>GRANT</command>/<command>REVOKE</command>
 to control access to <link
 linkend="lo-import"><function>lo_import()</function></link>
 and <function>lo_export()</function> (Michael Paquier)
</para>
Tom Lane is a co-author here I think.

<para>
 Add libpq parameter to allow physical and logical replication
 connections (Michael Paquier)
</para>
This commit has just added documentation which was missing and
incomplete.  I would suggest to remove it from the release notes as no
new feature has been added.

<para>
 Add <link
 linkend="app-pgreceivewal"><application>pg_receivewal</application></link>
 option <option>--no-sync</option> to prevent synchronous
 <acronym>WAL</acronym> writes (Michael Paquier)
</para>
Perhaps this should be rewritten?  --no-sync just disables any fsync
calls for WAL segments, which is useful for tests, not recommended for
production environments.

<para>
 Prevent <application>pg_rewind</application> from running as
 <literal>root</literal> (Magnus Hagander)
</para>
This one's authorship is actually mine, after a bug I found :)
--
Michael

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.