<!-- doc/src/sgml/release-10.sgml -->
<!-- See header comment in release.sgml about typical markup -->

 <sect1 id="release-10">
  <title>Release 10</title>

  <note>
   <title>Release Date</title>
   <simpara>2017-09-XX</simpara>
   <simpara>CURRENT AS OF 2017-04-22</simpara>
  </note>

  <sect2>
   <title>Overview</title>

   <para>
    Major enhancements in <productname>PostgreSQL</> 10 include:
   </para>

   <!-- Items in this list summarize one or more items below -->

   <itemizedlist>

   <listitem><para> </para></listitem>
   </itemizedlist>

   <para>
    The above items are explained in more detail in the sections below.
   </para>

  </sect2>

  <sect2>

  <title>Migration to Version 10</title>

   <para>
    A dump/restore using <xref linkend="app-pg-dumpall">, or use of <xref
    linkend="pgupgrade">, is required for those wishing to migrate data
    from any previous release.
   </para>

   <para>
    Version 10 contains a number of changes that may affect compatibility
    with previous releases.  Observe the following incompatibilities:
   </para>

   <itemizedlist>

    <listitem>
     <!--
     Copied here from this commit:
     Author: Robert Haas <rhaas@postgresql.org>
     2017-04-03 [ea69a0dea] Expand hash indexes more gradually.
     -->
     <para>
      <application>pg_upgrade</>-ed hash indexes from previous major
      Postgres versions must be rebuilt.
     </para>

     <para>
      Major hash storage improvements necessitated this requirement.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Peter Eisentraut <peter_e@gmx.net>
     2017-03-27 [3371e4d9b] Change default of log_directory to 'log'
     -->
     <para>
      Change the default <link linkend="guc-log-destination">log
      directory</> from <filename>pg_log</> to <filename>log</> (Andreas
      Karlsson)
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Robert Haas <rhaas@postgresql.org>
     2016-10-20 [f82ec32ac] Rename "pg_xlog" directory to "pg_wal"
     -->
     <para>
      Rename <filename>pg_xlog</> to <link
      linkend="wal"><filename>pg_wal</></> (Michael Paquier)
     </para>

     <para>
      This prevents the write-ahead log directory from being confused as
      containing server activity logs, and erroneously truncated.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Robert Haas <rhaas@postgresql.org>
     2017-02-09 [806091c96] Remove all references to "xlog" from SQL-callable functi
     Author: Robert Haas <rhaas@postgresql.org>
     2017-02-09 [85c11324c] Rename user-facing tools with "xlog" in the name to say 
     Author: Robert Haas <rhaas@postgresql.org>
     2017-02-09 [62e8b3875] Rename command line options for ongoing xlog -> wal conv
     Author: Fujii Masao <fujii@postgresql.org>
     2017-02-15 [0dfa89ba2] Replace reference to "xlog-method" with "wal-method" in 
     -->
     <para>
      Rename <acronym>SQL</> functions, tools, and options that reference
      <quote>xlog</> to <quote>wal</> (Robert Haas)
     </para>

     <para>
      For example, <function>pg_switch_xlog()</> becomes
      <function>pg_switch_wal()</>, <application>pg_receivexlog</>
      becomes <application>pg_receivewal</>, and <option>--xlogdir</>
      becomes <option>--waldir</>.  This might require adjustments for
      prior-version scripts.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Robert Haas <rhaas@postgresql.org>
     2017-03-17 [88e66d193] Rename "pg_clog" directory to "pg_xact".
     -->
     <para>
      Rename transaction status directory <filename>pg_clog</> directory
      to <filename>pg_xact</> (Michael Paquier)
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Andres Freund <andres@anarazel.de>
     2017-01-18 [69f4b9c85] Move targetlist SRF handling from expression evaluation 
     Author: Tom Lane <tgl@sss.pgh.pa.us>
     2017-01-18 [f13a1277a] Doc: improve documentation of new SRF-in-tlist behavior.
     -->
     <para>
      Allow <literal>COALESCE</> and <literal>CASE</> to return multiple
      rows when evaluating set-returning functions (Andres Freund).
     </para>

     <para>
      This also prevents conditionals like <literal>CASE</> from
      controlling the execution of set-returning functions because
      set-returning functions are now executed earlier.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Magnus Hagander <magnus@hagander.net>
     2017-01-04 [9a4d51077] Make wal streaming the default mode for pg_basebackup
     -->
     <para>
      Have <application><xref linkend="app-pgbasebackup"></> stream the
      <acronym>WAL</> needed to restore the backup by default (Magnus
      Hagander)
     </para>

     <para>
      This changes the <application>pg_basebackup</>
      <option>-X</>/<option>--xlog-method</> default to <literal>stream</>.
      An option value <literal>none</> has been added to recreate the old
      behavior.  The <application>pg_basebackup</> option <option>-x</>
      has been removed (use <option>-X</> fetch).
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Peter Eisentraut <peter_e@gmx.net>
     2017-01-14 [05cd12ed5] pg_ctl: Change default to wait for all actions
     -->
    <para>
     Make all <application><xref linkend="app-pg-ctl"></> actions wait
     by default for completion (Peter Eisentraut)
    </para>

    <para>
     Previously some <application>pg_ctl</> actions didn't wait for
     completion, and required the use of <option>-w</> to do so.
    </para>
    </listitem>

    <listitem>
     <!--
     Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
     2016-10-26 [94aceed31] Support multi-dimensional arrays in PL/python.
     Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
     2016-10-26 [cfd9c87a5] Only treat Python Lists as array dimensions.
     -->
    <para>
     Allow multi-dimensional arrays to be passed into PL/Python functions,
     and returned as nested Python lists (Alexey Grishchenko, Dave Cramer,
     Heikki Linnakangas)
    </para>

    <para>
     This makes a backwards-incompatible change to the handling of
     composite types in arrays. Previously, you could return an array of
     composite types as "[[col1, col2], [col1, col2]]", but now that is
     interpreted as a two- dimensional array. Composite types in arrays
     must now be returned as Python tuples, not lists, to resolve the
     ambiguity. I.e. "[(col1, col2), (col1, col2)]".  See the documentation
     for more details. CLARIFY
    </para>
    </listitem>

    <listitem>
     <!--
     Author: Tom Lane <tgl@sss.pgh.pa.us>
     2017-02-27 [817f2a586] Remove PL/Tcl's "module" facility.
     -->
    <para>
     Remove PL/Tcl's "module" auto-loading facility (Tom Lane)
    </para>

    <para>
     Replaced by new PL/Tcl startup <acronym>GUC</>s.
    </para>
    </listitem>

    <listitem>
     <!--
     Author: Robert Haas <rhaas@postgresql.org>
     2016-12-23 [e13486eba] Remove sql_inheritance <acronym>GUC</>.
     -->
    <para>
     Remove <varname>sql_inheritance</> <acronym>GUC</> (Robert Haas)
    </para>

    <para>
     Changing this from the default value caused queries referencing
     parent tables to not include children tables.  The <acronym>SQL</>
     standard requires such behavior and this has been the default since
     Postgres 7.1.
    </para>
    </listitem>

    <listitem>
     <!--
     Author: Robert Haas <rhaas@postgresql.org>
     2017-02-15 [51ee6f316] Replace min_parallel_relation_size with two new <acronym>GUC</>s.
     -->
    <para>
     Add <acronym>GUC</>s <xref linkend="guc-min-parallel-table-scan-size">
     and <xref linkend="guc-min-parallel-index-scan-size"> to control
     parallel operation (Amit Kapila, Robert Haas)
    </para>

    <para>
     This replaces <varname>min_parallel_relation_size</>, which was
     too generic.
    </para>
    </listitem>

    <listitem>
     <!--
     Author: Tom Lane <tgl@sss.pgh.pa.us>
     2016-10-12 [64f3524e2] Remove pg_dump/pg_dumpall support for dumping from pre-8
     -->
    <para>
     Remove <application>pg_dump</>/<application>pg_dumpall</> support
     for dumping from pre-8.0 servers (Tom Lane)
    </para>

     <para>
      Users needing dump support for pre-8.0 servers need to use dump
      binaries from Postgres 9.6.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Tom Lane <tgl@sss.pgh.pa.us>
     2017-02-23 [b6aa17e0a] De-support floating-point timestamps.
     -->
     <para>
      Remove support for floating-point datetimes/timestamps (Tom Lane)
     </para>

     <para>
      This removes configure's <option>--disable-integer-datetimes</>
      option.  Floating-point datetimes/timestamps have not been the
      default since Postgres 8.3 and have few advantages.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Tom Lane <tgl@sss.pgh.pa.us>
     2016-10-11 [2f1eaf87e] Drop server support for <acronym>FE/BE</> protocol version 1.0.
     -->
     <para>
      Remove support for client/server protocol version 1.0 (Tom Lane)
     </para>

     <para>
      This protocol hasn't had client support since Postgres 6.3.
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Robert Haas <rhaas@postgresql.org>
     2017-02-13 [7ada2d31f] Remove contrib/tsearch2.
     -->
     <para>
      Remove contrib/tsearch2 (Robert Haas)
     </para>

     <para>
      This removes compatibility with the contrib version of full text
      search that shipped in pre-8.3 Postgres versions.
    </para>
    </listitem>

    <listitem>
     <!--
     Author: Peter Eisentraut <peter_e@gmx.net>
     2017-03-23 [50c956add] Remove createlang and droplang
     -->
     <para>
      Remove createlang and droplang command-line applications (Peter
      Eisentraut)
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Andres Freund <andres@anarazel.de>
     2017-03-30 [5ded4bd21] Remove support for version-0 calling conventions.
     -->
     <para>
      Remove support for version-0 function calling conventions (Andres
      Freund)
     </para>
    </listitem>

    <listitem>
     <!--
     Author: Tom Lane <tgl@sss.pgh.pa.us>
     2016-10-11 [2b860f52e] Remove "sco" and "unixware" ports.
     -->
     <para>
      Remove <systemitem class="osname">SCO</> and <systemitem
      class="osname">Unixware</> ports (Tom Lane)
     </para>
    </listitem>

   </itemizedlist>

  </sect2>

  <sect2>
   <title>Changes</title>

   <para>
    Below you will find a detailed account of the changes between
   <productname>PostgreSQL</productname> 10 and the previous major
    release.
   </para>

   <sect3>
    <title>Server</title>

    <sect4>
     <title>Parallel Queries</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-02-15 [569174f1b] btree: Support parallel index scans.
       Author: Robert Haas <rhaas@postgresql.org>
       2017-02-15 [5262f7a4f] Add optimizer and executor support for parallel index sc
       Author: Robert Haas <rhaas@postgresql.org>
       2017-02-19 [0414b26ba] Add optimizer and executor support for parallel index-on
       -->
       <para>
        Support parallel btree index scans (Rahila Syed, Amit Kapila,
        Robert Haas, Rafia Sabih)
       </para>

       <para>
        Allows btree index pages to be checked by separate parallel
        workers.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-03-08 [98e6e8904] tidbitmap: Support shared iteration.
       Author: Robert Haas <rhaas@postgresql.org>
       2017-03-08 [f35742ccb] Support parallel bitmap heap scans.
       -->
       <para>
        Support parallel bitmap heap scans (Dilip Kumar)
       </para>

       <para>
        This allows a single index scan to dispatch parallel workers to
        process different areas of the heap.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-03-07 [3bc7dafa9] Consider parallel merge joins.
       -->
       <para>
        Allow merge joins to be performed in parallel (Dilip Kumar)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-02-14 [5e6d8d2bb] Allow parallel workers to execute subplans.
       -->
       <para>
        Allow non-correlated subqueries to be run in parallel (Amit Kapila)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-03-09 [355d3993c] Add a Gather Merge executor node.
       -->
       <para>
        Improve ability of parallel workers to return pre-sorted data
        (Rushabh Lathia)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-03-24 [61c2e1a95] Improve access to parallel query from procedural languag
       -->
       <para>
        Increase parallel query usage in procedural language functions
        (Robert Haas, Rafia Sabih)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2016-12-02 [b460f5d66] Add max_parallel_workers GUC.
       Author: Robert Haas <rhaas@postgresql.org>
       2016-12-05 [2b959d495] Reduce the default for max_worker_processes back to 8.
       -->
       <para>
        Add <acronym>GUC</> <xref linkend="guc-max-parallel-workers">
        to limit the number of worker processes that can be used for
        query parallelism (Julien Rouhaud)
       </para>

       <para>
        This can be set lower than <xref
        linkend="guc-max-worker-processes"> to reserve worker processes
        for purposes other than parallel queries.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Indexes</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2016-08-23 [77e290682] Create an SP-GiST opclass for inet/cidr.
       -->
       <para>
        Add <acronym>SP-GiST</> index support for <type>INET</> and
        <type>CIDR</> data types (Emre Hasegeli)
       </para>

       <para>
        These data types already had GiST support.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Teodor Sigaev <teodor@sigaev.ru>
       2017-03-23 [218f51584] Reduce page locking in <acronym>GIN</> vacuum
       -->
       <para>
        Reduce page locking during vacuuming of <acronym>GIN</> indexes
        (Andrey Borodin)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
       2017-04-01 [7526e1022] BRIN auto-summarization
       -->
       <para>
        Add option to allow <acronym>BRIN</> index summarization to happen
        more aggressively (&Aacute;lvaro Herrera)
       </para>

       <para>
        Specifically, a new <link linkend="SQL-ALTERINDEX"><command>CREATE
        INDEX</></> option allows auto-summarizion of the
        previous <acronym>BRIN</> page range when a new page
        range is created.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
       2017-04-01 [c655899ba] BRIN de-summarization
       -->
       <para>
        Add functions to remove and re-add <acronym>BRIN</>
        summarization for <acronym>BRIN</> index ranges (&Aacute;lvaro
        Herrera)
       </para>

       <para>
        New <acronym>SQL</> function <link
        linkend="functions-admin-index-table"><function>brin_summarize_range()</></>
        updates <acronym>BRIN</> index summarization for a specified
        range and <function>brin_desummarize_range()</> removes it.
        This is helpful to update summarization of a range that is now
        smaller due to <command>UPDATE</>s and <command>DELETE</>s.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
       2017-04-06 [7e534adcd] Fix BRIN cost estimation
       -->
       <para>
        Improve accuracy in determining if a <acronym>BRIN</> index scan
        is beneficial (David Rowley, Emre Hasegeli)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2016-09-09 [b1328d78f] Invent PageIndexTupleOverwrite, and teach BRIN and GiST
       -->
       <para>
        Allow faster <acronym>GiST</> inserts and updates by reusing
        index space more efficiently (Andrey Borodin)
       </para>
      </listitem>

     </itemizedlist>
        
     <sect5>
      <title><link linkend="indexes-types">Hash Indexes</link></title>

      <itemizedlist>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-02-27 [30df93f69] hash: Refactor overflow page allocation.
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-14 [c11453ce0] hash: Add write-ahead logging support.
        Author: Robert Haas <rhaas@postgresql.org>
        2017-02-27 [b0f18cb77] hash: Refactor bucket squeeze code.
        -->
        <para>
         Add write-ahead logging support to hash indexes (Amit Kapila)
        </para>

        <para>
         This makes hash indexes crash-safe and replicated, and removes
         the warning message about their use.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2016-11-30 [6d46f4783] Improve hash index bucket split behavior.
        Author: Robert Haas <rhaas@postgresql.org>
        2017-02-07 [293e24e50] Cache hash index's metapage in rel->rd_amcache.
        Author: Robert Haas <rhaas@postgresql.org>
        -->
        <para>
         Improve hash bucket split performance by reducing locking
         requirements (Amit Kapila, Mithun Cy)
        </para>

        <para>
         Also cache hash index meta-information for faster lookups.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-04-03 [ea69a0dea] Expand hash indexes more gradually.
        -->
        <para>
         Improve efficiency of hash index growth (Amit Kapila, Mithun Cy)
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-15 [6977b8b7f] Port single-page btree vacuum logic to hash indexes.
        -->
        <para>
         Allow single-page hash pruning (Ashutosh Sharma)
        </para>
       </listitem>

      </itemizedlist>

     </sect5>

    </sect4>

    <sect4>

     <title>Locking</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-03-31 [64d4da511] For foreign keys, check <literal>REFERENCES</> privilege only on the
       -->
       <para>
        Only check for <literal>REFERENCES</> permission on referenced
        tables (Tom Lane)
       </para>

       <para>
        Previously <literal>REFERENCES</> permission on the referencing
        table was also required.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2016-09-05 [15bc038f9] Relax transactional restrictions on ALTER TYPE ... ADD V
       -->
       <para>
        Reduce locking required for adding values to enum types (Andrew
        Dunstan, Tom Lane)
       </para>

       <para>
        Previously it was impossible to run <command>ALTER TYPE ... ADD
        VALUE</> in a transaction block unless the enum type was created
        in the same block.  Now, only references to uncommitted enum
        values from other transactions is prohibited.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Kevin Grittner <kgrittn@postgresql.org>
       2017-04-07 [c63172d60] Add GUCs for predicate lock promotion thresholds.
       -->
       <para>
        Allow tuning of predicate lock promotion thresholds (Dagfinn
        Ilmari Manns&aring;ker)
       </para>

       <para>
        The new settings are <xref
        linkend="guc-max-pred-locks-per-relation"> and
        <xref linkend="guc-max-pred-locks-per-page">.
       </para>
      </listitem>

    </itemizedlist>

    </sect4>

    <sect4>
     <title>Optimizer</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
       2017-03-24 [7b504eb28] Implement multivariate n-distinct coefficients
       Author: Simon Riggs <simon@2ndQuadrant.com>
       2017-04-05 [2686ee1b7] Collect and use multi-column dependency stats
       -->
      <para>
       Add multi-column optimizer statistics to compute the correlation
       ratio and number of distinct values (Tomas Vondra, David Rowley,
       &Aacute;lvaro Herrera)
      </para>

      <para>
       New commands are <command><link
       linkend="SQL-CREATESTATISTICS">CREATE</></>,
      <command><link linkend="SQL-ALTERSTATISTICS">ALTER</></>, and
      <command><link linkend="SQL-DROPSTATISTICS">DROP STATISTICS</></>.
      This is helpful in
       estimating query memory usage and when combining the statistics
       from individual columns.
      </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-15 [0777f7a2e] Fix matching of boolean index columns to sort ordering.
       -->
      <para>
       Improve planner matching of boolean indexes (Tom Lane)
      </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-18 [215b43cdc] Improve RLS planning by marking individual quals with se
       -->
      <para>
       Improve performance of queries referencing row-level security
       restrictions (Tom Lane)
      </para>

      <para>
       The optimizer now has more flexibility in reordering executor
       behavior.
      </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>General Performance</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2016-09-02 [9cca11c91] Speed up SUM calculation in numeric aggregates.
       -->
       <para>
        Speed up <function>SUM()</> calculations (Heikki Linnakangas)
       </para>

       <para>
        This uses an optimized numeric accumulator.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2017-03-13 [aeed17d00] Use radix tree for character encoding conversions.
       -->
       <para>
        Improve the performance of character encoding conversions by
        using radix trees (Kyotaro Horiguchi, Heikki Linnakangas)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Andres Freund <andres@anarazel.de>
       2017-03-25 [b8d7f053c] Faster expression evaluation and targetlist projection.
       -->
       <para>
        Reduce the function call overhead during query execution (Andres
        Freund)
       </para>

       <para>
        This is particularly helpful for queries that process many rows.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Andrew Gierth <rhodiumtoad@postgresql.org>
       2017-03-27 [b5635948a] Support hashed aggregation with grouping sets.
       -->
       <para>
        Improve the performance of grouping sets (Andrew Gierth)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-04-07 [9c7f5229a] Optimize joins when the inner relation can be proven uni
       -->
       <para>
        Use uniqueness guarantees to optimize certain join types (David
        Rowley)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Teodor Sigaev <teodor@sigaev.ru>
       2017-03-29 [f90d23d0c] Implement SortSupport for macaddr data type
       -->
       <para>
        Improve sort performance of the macaddr data type (Brandur Leach)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Teodor Sigaev <teodor@sigaev.ru>
       2017-03-27 [090010f2e] Improve performance of find_tabstat_entry()/get_tabstat_
       -->
       <para>
        Reduce statistics tracking overhead in sessions that reference
        many thousands of relations (Aleksander Alekseev)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Monitoring</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-12-20 [1753b1b02] Add pg_sequence system catalog
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-11-18 [67dc4ccbb] Add pg_sequences view
       -->
       <para>
        Create a <link
        linkend="catalog-pg-sequence"><structname>pg_sequence</></>
        system catalog to store sequence metadata (Peter Eisentraut)
       </para>

       <para>
        Sequence metadata includes start, increment, etc,
        which is now transactional.  Sequence counters are
        still stored in separate heap relations.  Also add <link
        linkend="view-pg-sequences"><structname>pg_sequences</></> view
        to show all sequences.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Stephen Frost <sfrost@snowman.net>
       2017-03-08 [f9b1a0dd4] Expose explain's SUMMARY option
       -->
       <para>
        Allow explicit control over <command><link
        linkend="SQL-EXPLAIN">EXPLAIN</></>'s display of planning and
        execution time (Ashutosh Bapat)
       </para>

       <para>
        By default planning and execution time are displayed by
        <command>EXPLAIN ANALYZE</> and are not displayed in other cases.
        The new <command>EXPLAIN</> option <literal>SUMMARY</> allows
        explicit control of this.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-03-18 [17f8ffa1e] Fix <command>REFRESH MATERIALIZED VIEW</> to report activity to the 
       -->
       <para>
        Properly update the statistics collector during <link
        linkend="SQL-REFRESHMATERIALIZEDVIEW"><command>REFRESH MATERIALIZED
        VIEW</></> (Jim Mlodgenski)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Simon Riggs <simon@2ndQuadrant.com>
       2017-03-30 [25fff4079] Default monitoring roles
       -->
       <para>
        Add default monitoring roles (Dave Page)
       </para>

       <para>
        New roles <literal>pg_monitor</>, <literal>pg_read_all_settings</>,
        <literal>pg_read_all_stats</>, and <literal>pg_stat_scan_tables</>
        allow simplified permission configuration.
       </para>
      </listitem>

     </itemizedlist>
         
     <sect5>
      <title>Logging</title>

      <itemizedlist>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2016-10-17 [7d3235ba4] By default, set log_line_prefix = '%m [%p] '.
        -->
        <para>
         Change <xref linkend="guc-log-line-prefix"> default to include
         current timestamp with milliseconds and the process id (Christoph
         Berg)
        </para>

        <para>
         The previous default was not to output a prefix.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-16 [befd73c50] Add pg_ls_logdir() and pg_ls_waldir() functions.
        -->
        <para>
         Add functions to return the log and <acronym>WAL</> directory
         names (Dave Page)
        </para>

        <para>
         The new functions are <link
         linkend="functions-admin-genfile-table"><function>pg_ls_logdir()</></>
         and
        <link
        linkend="functions-admin-genfile-table"><function>pg_ls_waldir()</></>
        and can be
         executed by non-super users with the proper permissions.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-03 [19dc233c3] Add pg_current_logfile() function.
        -->
        <para>
         Add function <link
         linkend="functions-info-session-table"><function>pg_current_logfile()</></>
         to read syslog's current stderr and csvlog output file names
         (Gilles Darold)
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Tom Lane <tgl@sss.pgh.pa.us>
        2017-03-10 [f9dfa5c97] Improve postmaster's logging of listen socket creation.
        Author: Tom Lane <tgl@sss.pgh.pa.us>
        2017-03-14 [2b32ac2a5] Include port number when logging successful binding to a
        -->
        <para>
         Report the address and port number of successful startup socket
         binding in the server logs (Tom Lane)
        </para>

        <para>
         Also, report bind socket failure details in the server logs.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Tom Lane <tgl@sss.pgh.pa.us>
        2017-03-10 [6ec4c8584] Reduce log verbosity of startup/shutdown for launcher su
        -->
        <para>
         Reduce log chatter about the starting and stopping of launcher
         subprocesses (Tom Lane)
        </para>

        <para>
         These are now <literal>DEBUG1</>-level messages.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2016-11-17 [a43f1939d] Remove or reduce verbosity of some debug messages.
        -->
        <para>
         Reduce message verbosity of lower-numbered debug levels
         controlled by
        <xref linkend="guc-log-min-messages"> (Robert Haas)
        </para>

        <para>
         This also changes the verbosity of <xref
         linkend="guc-client-min-messages"> debug levels.
        </para>
       </listitem>

      </itemizedlist>

     </sect5>
          
     <sect5>
      <title><link linkend="pg-stat-activity-view"><structname>pg_stat_activity</></link></title>

      <itemizedlist>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2016-10-04 [6f3bd98eb] Extend framework from commit 53be0b1ad to report latch w
        -->
        <para>
         Add <structname>pg_stat_activity</> reporting of latch wait states
         (Michael Paquier, Robert Haas)
        </para>

        <para>
         This includes the remaining wait events, like client reads,
         client writes, and synchronous replication.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-18 [249cf070e] Create and use wait events for read, write, and fsync op
        -->
        <para>
         Add <structname>pg_stat_activity</> reporting of waits on reads,
         writes, and fsyncs (Rushabh Lathia)
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-26 [fc70a4b0d] Show more processes in pg_stat_activity.
        -->
        <para>
         Show auxiliary processes and background workers in
         <structname>pg_stat_activity</> (Kuntal Ghosh)
        </para>

        <para>
         New column <structfield>backend_type</> identifies the process
         type.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Simon Riggs <simon@2ndQuadrant.com>
        2016-09-12 [fc3d4a44e] Identify walsenders in pg_stat_activity
        -->
        <para>
         Display walsender processes in <structname>pg_stat_activity</>
         (Michael Paquier)
        </para>

        <para>
         This simplifies monitoring.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-02-22 [4c728f382] Pass the source text for a parallel query to the workers
        -->
        <para>
         Allow <structname>pg_stat_activity</> to show the source query
         being executed by parallel workers (Rafia Sabih)
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2016-12-16 [3761fe3c2] Simplify LWLock tranche machinery by removing array_base
        -->
        <para>
         Rename
         <structname>pg_stat_activity</>.<structfield>wait_event_type</>
         values <literal>LWLockTranche</> and
        <literal>LWLockNamed</> to <literal>LWLock</> (Robert Haas)
        </para>

        <para>
         This makes the output more consistent.
        </para>
       </listitem>

      </itemizedlist>

     </sect5>
       
    </sect4>

    <sect4>
     <title><acronym>Authentication</></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2017-03-07 [818fd4a67] Support SCRAM-SHA-256 authentication (RFC 5802 and 7677)
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2017-03-24 [7ac955b34] Allow SCRAM authentication, when pg_hba.conf says 'md5'.
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2017-04-07 [60f11b87a] Use SASLprep to normalize passwords for SCRAM authentica
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2017-04-18 [c727f120f] Rename "scram" to "scram-sha-256" in pg_hba.conf and pas
       -->
       <para>
        Add <link linkend="auth-pg-hba-conf"><literal>SCRAM-SHA-256</></>
        support for password negotiation and storage (Michael Paquier,
        Heikki Linnakangas)
      </para>

       <para>
        This provides better security than the existing <literal>md5</>
        negotiation and storage method.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
       2016-09-28 [babe05bc2] Turn password_encryption <acronym>GUC</> into an enum.
       -->
       <para>
        Change <acronym>GUC</> <xref linkend="guc-password-encryption">
        from <type>boolean</> to <type>enum</> (Michael Paquier)
       </para>

       <para>
        This was necessary to support additional password hashing options.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-30 [de16ab723] Invent pg_hba_file_rules view to show the content of pg_
       -->
       <para>
        Add view <link
        linkend="view-pg-hba-file-rules"><structname>pg_hba_file_rules</></>
        to display the contents of <filename>pg_hba.conf</> (Haribabu
        Kommi)
       </para>

       <para>
        This shows the file contents, not the currently active settings.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Magnus Hagander <magnus@hagander.net>
       2017-03-22 [6b76f1bb5] Support multiple RADIUS servers
       -->
       <para>
        Support multiple <acronym>RADIUS</> servers (Magnus Hagander)
       </para>

       <para>
        All the <acronym>RADIUS</> related parameters are now plural and
        support a comma-separated list of servers.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Server Configuration</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-02 [de41869b6] Allow SSL configuration to be updated at SIGHUP.
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-03 [1e942c747] Disable prompting for passphrase while (re)loading SSL c
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-04 [6667d9a6d] Re-allow SSL passphrase prompt at server start, but not 
       -->
       <para>
        Allow <acronym>SSL</> configuration to be updated during
        configuration reload (Andreas Karlsson, Tom Lane)
       </para>

       <para>
        This allows <acronym>SSL</> to be reconfigured without a server
        restart by using <command>pg_ctl reload</>, <command>SELECT
        pg_reload_conf()</>, or sending a <literal>SIGHUP</> signal.
        Reload <acronym>SSL</> configuration updates do not work if the
        <acronym>SSL</> key requires a passphrase.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-11-30 [81c52728f] doc: Remove claim about large shared_buffers on Windows
       -->
       <para>
        Remove documented restriction about using large shared buffers on
       <systemitem class="osname">Windows</> (Takayuki Tsunakawa)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Simon Riggs <simon@2ndQuadrant.com>
       2017-03-06 [21d4e2e20] Reduce lock levels for table storage params related to p
       Author: Simon Riggs <simon@2ndQuadrant.com>
       2017-04-05 [68ea2b7f9] Reduce lock level for CREATE STATISTICS
       -->
       <para>
        Reduce locking required to change table params (Simon Riggs,
        Fabr&iacute;zio Mello)
       </para>

       <para>
        For example, changing a table's <xref
        linkend="guc-effective-io-concurrency"> setting can now be done
        with a more lightweight lock.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2017-02-02 [14ca9abfb] Increase upper bound for bgwriter_lru_maxpages.
       -->
       <para>
        Make the maximum value of <xref
        linkend="guc-bgwriter-lru-maxpages"> effectively unlimited
        (Jim Nasby)
       </para>
      </listitem>

    </itemizedlist>

    </sect4>

    <sect4>
     <title>Reliability</title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Teodor Sigaev <teodor@sigaev.ru>
       2017-03-27 [1b02be21f] Fsync directory after creating or unlinking file.
       -->
       <para>
        Perform an fsync on the directory after creating or unlinking files
        (Michael Paquier)
       </para>

       <para>
        This reduces the risk of data loss after a power failure.
       </para>
      </listitem>

     </itemizedlist>

     <sect5>
      <title><link linkend="wal">Write-Ahead Log</> (<acronym>WAL</>)</title>

      <itemizedlist>

       <listitem>
        <!--
        Author: Andres Freund <andres@anarazel.de>
        2016-12-22 [6ef2eba3f] Skip checkpoints, archiving on idle systems.
        -->
        <para>
         Prevent checkpoints and <acronym>WAL</> archiving on
         otherwise-idle systems (Michael Paquier)
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Robert Haas <rhaas@postgresql.org>
        2017-02-08 [a507b8690] Add WAL consistency checking facility.
        Author: Robert Haas <rhaas@postgresql.org>
        2017-03-14 [bb4a39637] hash: Support WAL consistency checking.
        -->
        <para>
         Add <acronym>GUC</> <xref linkend="guc-wal-consistency-checking">
         to add details to <acronym>WAL</> that can be sanity-checked on
         the standby (Kuntal Ghosh, Robert Haas)
        </para>

        <para>
         Any sanity-check failure generates a fatal error on the standby.
        </para>
       </listitem>

       <listitem>
        <!--
        Author: Simon Riggs <simon@2ndQuadrant.com>
        2017-04-05 [00b6b6feb] Allow \-\-with-wal-segsize=n up to n=1024MB
        -->
        <para>
         Increase the maximum configurable <acronym>WAL</> segment size
         to one gigabyte (Beena Emerson)
        </para>

        <para>
         Larger <acronym>WAL</> segment sizes allows for fewer
         <xref linkend="guc-archive-command"> invocations and fewer
         <acronym>WAL</> files to manage.
        </para>
       </listitem>

      </itemizedlist>
          
     </sect5>

    </sect4>

   </sect3>

   <sect3>
    <title>Replication and Recovery</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-01-20 [665d1fad9] Logical replication
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-23 [7c4f52409] Logical replication support for initial data copy
      Author: Fujii Masao <fujii@postgresql.org>
      2017-04-12 [ff7bce174] Add max_sync_workers_per_subscription to postgresql.conf
      -->
      <para>
       Add the ability to <link linkend="logical-replication">logically
       replicate</> tables to standby servers (Petr Jelinek)
      </para>

      <para>
       This allows more fine-grained replication options, including
       replication between different major versions of Postgres and
       selective-table replication.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Fujii Masao <fujii@postgresql.org>
      2016-12-19 [3901fd70c] Support quorum-based synchronous replication.
      -->
      <para>
       Allow waiting for commit acknowledgement from standby
       servers irrespective of the order they appear in <xref
       linkend="guc-synchronous-standby-names"> (Masahiko Sawada)
      </para>

      <para>
       Previously the server always waited for the active standbys that
       appeared first in <varname>synchronous_standby_names</>.  The new
       <varname>synchronous_standby_names</> keyword <literal>ANY</> allows
       waiting for any number of standbys irrespective of their ordering.
       This is known as quorum commit.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Magnus Hagander <magnus@hagander.net>
      2017-01-14 [f6d6d2920] Change default values for backup and replication paramet
      -->
      <para>
       Reduce configuration necessary to perform streaming backup and
       replication (Magnus Hagander)
      </para>

      <para>
       Specifically, defaults were changed for <xref
       linkend="guc-wal-level">, <xref linkend="guc-max-wal-senders">,
       and <xref linkend="guc-max-replication-slots">.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-09 [be37c2120] Enable replication connections by default in <filename>pg_hba.conf</>
      -->
      <para>
       Enable replication from localhost connections by default in
       <link linkend="auth-pg-hba-conf"><filename>pg_hba.conf</></>
       (Michael Paquier)
      </para>

      <para>
       Previously <filename>pg_hba.conf</>'s replication connection
       lines were commented out.  This is particularly useful for
       <application><xref linkend="app-pgbasebackup"></>.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Simon Riggs <simon@2ndQuadrant.com>
      2017-03-23 [6912acc04] Replication lag tracking for walsenders
      -->
      <para>
       Add columns to <link
       linkend="monitoring-stats-views-table"><structname>pg_stat_replication</></>
       to report replication delay times (Thomas Munro)
      </para>

      <para>
       The new columns are <structfield>write_lag</>,
       <structfield>flush_lag</>, and <structfield>replay_lag</>.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Simon Riggs <simon@2ndQuadrant.com>
      2016-09-03 [35250b6ad] New recovery target recovery_target_lsn
      -->
      <para>
       Add specification of a Log Sequence Number (<acronym>LSN</>)
       stopping point in
      <link linkend="recovery-config"><filename>recovery.conf</></>
      (Michael Paquier)
      </para>

      <para>
       Previously only specification of the stop name, time, timeline,
       xid, and immediate were supported.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Stephen Frost <sfrost@snowman.net>
      2017-03-22 [017e4f258] Expose waitforarchive option through pg_stop_backup()
      -->
      <para>
       Allow users to disable <link
       linkend="functions-admin"><function>pg_stop_backup()</></>'s
       waiting for all <acronym>WAL</> to be archived (David Steele)
      </para>

      <para>
       An optional second argument to <function>pg_stop_backup()</>
       controls that behavior.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2016-12-12 [a924c327e] Add support for temporary replication slots
      -->
      <para>
       Allow creation of <link
       linkend="functions-replication-table">temporary replication slots</>
       (Petr Jelinek)
      </para>

      <para>
       Temporary slots are automatically removed on session exit or error.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Simon Riggs <simon@2ndQuadrant.com>
      2017-03-22 [9b013dc23] Improve performance of replay of AccessExclusiveLocks
      -->
      <para>
       Improve performance of hot standby replay with better tracking of
       Access Exclusive locks (Simon Riggs, David Rowley)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Simon Riggs <simon@2ndQuadrant.com>
      2017-04-04 [728bd991c] Speedup 2PC recovery by skipping two phase state files i
      -->
      <para>
       Speed up two-phase commit recovery performance (Stas Kelvich,
       Nikhil Sontakke, Michael Paquier)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Queries</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
      2017-03-08 [fcec6caaf] Support XMLTABLE query expression
      -->
      <para>
       Add <link
       linkend="functions-xml-processing-xmltable"><function>XMLTABLE</></>
       function that converts <type>XML</>-formatted data into a row set
       (Pavel Stehule, &Aacute;lvaro Herrera)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-11-22 [906bfcad7] Improve handling of "UPDATE ... SET (column_list) = row_
      -->
      <para>
       Allow <literal>ROW</> to supply values to <command>UPDATE ... SET
       (column_list)</> (Tom Lane)
      </para>

      <para>
       Also allow row values to be supplied by table.*.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-09-05 [c54159d44] Make locale-dependent regex character classes work for l
      -->
      <para>
       Fix regular expression locale class handling for bytes greater
       than <literal>U+7FF</> (Tom Lane)
      </para>

      <para>
       Previously such classes were not recognized.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Utility Commands</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-12-07 [f0e44751d] Implement table partitioning.
      -->
      <para>
       Add table <link linkend="SQL-CREATETABLE-PARTITION">partitioning
       syntax</> that automatically creates partition constraints and
       <command>INSERT</> routing (Amit Langote)
      </para>

      <para>
       The syntax supports range and list partitioning.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Kevin Grittner <kgrittn@postgresql.org>
      2016-11-04 [8c48375e5] Implement syntax for transition tables in AFTER triggers
      Author: Kevin Grittner <kgrittn@postgresql.org>
      2017-04-04 [5ebeb579b] Follow-on cleanup for the transition table patch.
      Author: Kevin Grittner <kgrittn@postgresql.org>
      2017-03-31 [597027163] Add transition table support to plpgsql.
      -->
      <para>
       Add <link linkend="SQL-CREATETRIGGER"><literal>AFTER</> trigger</>
       transition table to record changed rows (Kevin Grittner)
      </para>

      <para>
       Transition table contents are accessible from server-side languages.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Stephen Frost <sfrost@snowman.net>
      2016-12-05 [093129c9d] Add support for restrictive RLS policies
      -->
      <para>
       Allow <link linkend="SQL-CREATEPOLICY">restrictive row-level
       security policies</> (Stephen Frost)
      </para>

      <para>
       Previously all security policies were permissive, meaning that any
       matching policy allowed access.  Optional restrictive policies must
       match for access to be granted.  These policy types can be combined.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Teodor Sigaev <teodor@sigaev.ru>
      2017-03-28 [ab89e465c] Altering default privileges on schemas
      -->
      <para>
       Allow <link linkend="SQL-ALTERDEFAULTPRIVILEGES">default
       permissions</> on schemas (Matheus Oliveira)
      </para>

      <para>
       This is done using the <literal>ALTER DEFAULT PRIVILEGES</> command.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-02-10 [2ea5b06c7] Add CREATE SEQUENCE AS <data type> clause
      -->
      <para>
       Add <link linkend="SQL-CREATESEQUENCE"><command>CREATE SEQUENCE
       AS</></> command to create a sequence matching an integer data type
       (Peter Eisentraut)
      </para>

      <para>
       This simplifies the creation of sequences matching the range of
       base columns.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-11-10 [279c439c7] Support "COPY view FROM" for views with INSTEAD OF INSER
      -->
      <para>
       Allow <command>COPY view FROM</> on views with <literal>INSTEAD
       INSERT</> triggers (Haribabu Kommi)
      </para>

      <para>
       The triggers are fed the rows from <command>COPY</>.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-14 [aefeb6874] Allow referring to functions without arguments when uniq
      -->
      <para>
       Allow the specification of a function name without arguments in
       <acronym>DDL</> commands, when unique (Peter Eisentraut)
      </para>

      <para>
       For example, allow <link linkend="SQL-DROPFUNCTION"><command>DROP
       FUNCTION</></> on a function name without arguments if there
       is only one function with that name.  This is required by the
       <acronym>SQL</> standard.
      </para>
     </listitem>

     <listitem>
      <!--<listitem>
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-06 [583f6c414] Allow dropping multiple functions at once
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-14 [aefeb6874] Allow referring to functions without arguments when uniq-->
      <para>
       Allow multiple functions, operators, and aggregates to be dropped
       with a single <command>DROP</> command (Peter Eisentraut)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andrew Dunstan <andrew@dunslane.net>
      2017-03-20 [b6fb534f1] Add IF NOT EXISTS for CREATE SERVER and CREATE USER MAPP
      -->
      <para>
       Add <literal>IF NOT EXISTS</> for <link
       linkend="SQL-CREATESERVER"><command>CREATE SERVER</></> and
      <link linkend="SQL-CREATEUSERMAPPING"><command>CREATE USER
      MAPPING</></> (Anastasia
       Lubennikova)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-02-15 [6d16ecc64] Add CREATE COLLATION IF NOT EXISTS clause
      -->
      <para>
       Add <literal>IF NOT EXISTS</> clause to <link
       linkend="SQL-CREATECOLLATION"><command>CREATE COLLATION</></>
       (Peter Eisentraut)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Fujii Masao <fujii@postgresql.org>
      2017-03-25 [70adf2fbe] Make VACUUM VERBOSE report the number of skipped frozen 
      Author: Simon Riggs <simon@2ndQuadrant.com>
      2017-03-03 [9eb344faf] Allow vacuums to report oldestxmin
      -->
      <para>
       Have <link linkend="SQL-VACUUM"><command>VACUUM VERBOSE</></> report
       the number of skipped frozen pages and oldest xmin (Masahiko
       Sawada, Simon Riggs)
      </para>

      <para>
       This information is also included in <xref
       linkend="guc-log-autovacuum-min-duration"> output.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
      2017-01-23 [7e26e02ee] Prefetch blocks during lazy vacuum's truncation scan
      -->
      <para>
       Improve speed of <command>VACUUM</>'s removal of trailing empty
       heap pages (Claudio Freire, &Aacute;lvaro Herrera)
      </para>

      <para>
       This information is also included in <xref
       linkend="guc-log-autovacuum-min-duration"> output.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2017-01-16 [d43a619c6] Fix check_srf_call_placement() to handle VALUES cases co
      -->
      <para>
       Fix <function>check_srf_call_placement()</> to handle
       <command>VALUES</> cases correctly (Tom Lane)
      </para>

      <para>
      NEED TEXT.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Data Types</title>

    <itemizedlist>

      <listitem>
       <!--
       Author: Andrew Dunstan <andrew@dunslane.net>
       2017-03-31 [e306df7f9] Full Text Search support for <type>JSON</> and <type>JSONB</>
       -->
       <para>
        Add full text search support for <type>JSON</> and <type>JSONB</>
        (Dmitry Dolgov)
       </para>

       <para>
        This is accessed via <function>ts_headline()</> and
        <function>to_tsvector</>.
       </para>
      </listitem>

     <listitem>
      <!--
      Author: Stephen Frost <sfrost@snowman.net>
      2017-03-15 [c7a9fa399] Add support for EUI-64 MAC addresses as macaddr8
      -->
      <para>
       Add support for <acronym>EUI-64</> <acronym>MAC</> addresses as
       <link linkend="datatype-macaddr8"><type>MACADDR8</></> (Haribabu
       Kommi)
      </para>

      <para>
       This complements support for <acronym>EUI-48</> <acronym>MAC</>
       addresses as <type>macaddr</>.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-04-06 [321732705] Identity columns
      -->
      <para>
       Add <link linkend="SQL-CREATETABLE">identity columns</> for
       assigning a numeric value to columns on insert (Peter Eisentraut)
      </para>

      <para>
       These are similar to <type>SERIAL</> columns, but are
       <acronym>SQL</> standard compliant.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-09-07 [0ab9c56d0] Support renaming an existing value of an enum type.
      -->
      <para>
       Allow <link linkend="datatype-enum"><type>ENUM</></> values to be
       renamed (Dagfinn Ilmari Manns&aring;ker)
      </para>

      <para>
       This uses the syntax <link linkend="SQL-ALTERTYPE"><command>ALTER
       TYPE ... RENAME VALUE</></>.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andrew Dunstan <andrew@dunslane.net>
      2017-02-22 [502a3832c] Correctly handle array pseudotypes in to_json and to_jso
      -->
      <para>
       Properly treat array pseudotypes
       (<type>anyarray</>) as arrays in <link
       linkend="functions-json-creation-table"><function>to_json()</></>
       and <function>to_jsonb()</> (Andrew Dunstan)
      </para>

      <para>
       Previously "anyarray" values were converted to <type>JSON</>
       strings.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-01-17 [323b96aa3] Register missing money operators in system catalogs
      -->
      <para>
       Add <link linkend="datatype-money"><type>MONEY</></> operators
       for multiplication and division with <type>INT8</> values (Peter
       Eisentraut)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2016-09-14 [656df624c] Add overflow checks to money type input function
      -->
      <para>
       More strictly check the <type>MONEY</> type for overflow operations
       (Peter Eisentraut)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Functions</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-08-17 [cf9b0fea5] Implement regexp_match(), a simplified alternative to re
      -->
      <para>
       Add simplified <link
       linkend="functions-posix-regexp"><function>regexp_match()</></>
       function (Emre Hasegeli)
      </para>

      <para>
       Similar to <function>regexp_matches()</>, but only returns results
       from the first match so it is easier use for simple cases.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Magnus Hagander <magnus@hagander.net>
      2017-01-18 [d00ca333c] Implement array version of jsonb_delete and operator
      -->
      <para>
       Add version of jsonb's <link
       linkend="functions-jsonb-op-table">delete operator</> that takes
       an array of keys to delete (Magnus Hagander)
      </para>

      <para>
       The <type>JSONB</> delete operator also now supports arrays.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andrew Dunstan <andrew@dunslane.net>
      2017-04-06 [cf35346e8] Make json_populate_record and friends operate recursivel
      -->
      <para>
       Improve <link
       linkend="functions-json-processing-table"><function>json_populate_record</></>
       and friends operate recursively (Nikita Glukhov)
      </para>

      <para>
       CLARIFY
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-08-23 [86f31695f] Add txid_current_ifassigned().
      -->
      <para>
       Add function <link
       linkend="functions-txid-snapshot"><function>txid_current_ifassigned()</></>
       to return <literal>NULL</> if no transaction id has been assigned
       (Craig Ringer)
      </para>

      <para>
       This is different from <link
       linkend="functions-txid-snapshot"><function>txid_current()</></>,
       which always returns a transaction id by assigning one if necessary.
       This can be also run on standby servers.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2017-03-24 [857ee8e39] Add a txid_status function.
      -->
      <para>
       Add function <link
       linkend="functions-txid-snapshot"><function>txid_status()</></>
       to check if a transaction was committed (Craig Ringer)
      </para>

      <para>
       This is useful for checking after an abrupt disconnection if
       your previous transaction committed and you just didn't receive
       the acknowledgement.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Alvaro Herrera <alvherre@alvh.no-ip.org>
      2017-01-19 [30bcebbdc] Allow negative years in make_date to represent BC years
      -->
      <para>
       Allow <link
       linkend="functions-formatting-table"><function>make_date()</></>
       to interpret negative years as <acronym>BC</> years (&Aacute;lvaro
       Herrera)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-09-28 [d3cd36a13] Make to_timestamp() and to_date() range-check fields of 
      -->
      <para>
       Have <function>to_timestamp()</> and <function>to_date()</> check
       input values for validity (Artur Zakirov)
      </para>

      <para>
       Previously <function>to_date('2009-06-40','YYYY-MM-DD')</> was
       accepted and returned '2009-07-10'.  It will now generate an error.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Server-Side Languages</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-27 [70ec3f1f8] PL/Python: Add cursor and execute methods to plan object
      -->
      <para>
       Allow the  PL/Python plan object to call cursor and execute methods
       (Peter Eisentraut)
      </para>

      <para>
       This is a more object oriented style.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-12-13 [55caaaeba] Improve handling of array elements as getdiag_targets an
      -->
      <para>
       Allow PL/pgSQL's <command>GET DIAGNOSTICS</> to retrieve values
       into array elements (Tom Lane)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-11-08 [1833f1a1c]     Simplify code by getting rid of SPI_push, SPI_pop, SPI_r
      -->
      <para>
       Remove <acronym>SPI</> functions <function>SPI_push()</>,
       <function>SPI_pop()</>, <function>SPI_restore_connection()</>
       as unnecessary (Tom Lane)
      </para>

      <para>
       Their functionality now happens automatically.  Also,
       <function>SPI_palloc()</> now requires an active connection.
      </para>
     </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="pltcl">PL/Tcl</></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2016-11-06 [26abb50c4] Support PL/Tcl functions that return composite types and
       -->
       <para>
        Allow PL/Tcl functions to return composite types and sets
        (Jim Nasby)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-03-11 [b58fd4a9c] Add a "subtransaction" command to PL/Tcl.
       -->
       <para>
        Add a subtransaction command to PL/Tcl (Victor Wagner)
       </para>

       <para>
        This allows PL/Tcl queries to fail without aborting the entire
        function.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-03-07 [0d2b1f305] Invent start_proc parameters for PL/Tcl.
       -->
       <para>
        Add <acronym>GUC</>s to allow initialization routines to be called
        on PL/Tcl startup (Tom Lane)
       </para>

       <para>
        The <acronym>GUC</>s are <varname>pltcl.start_proc</> and
        <varname>pltclu.start_proc</>.
       </para>
      </listitem>

     </itemizedlist>
      
    </sect4>
     
   </sect3>

   <sect3>
    <title>Client Interfaces</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-11-03 [274bb2b38] libpq: Allow connection strings and <acronym>URI</>s to specify mult
      -->
      <para>
       Allow libpq to connect to <link
       linkend="libpq-connect-host">multiple specified</> host names
       (Robert Haas)
      </para>

      <para>
       libpq will connect with the first responsive host name.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-11-29 [721f7bd3c] libpq: Add target_session_attrs parameter.
      -->
      <para>
       Allow the libpq connection string to request a <link
       linkend="libpq-connect-target-session-attrs">read/write host</>
       (Victor Wagner, Mithun Cy)
      </para>

      <para>
       This is useful when multiple libpq host names are
       specified, and is controlled by libpq connection parameter
       <option>target_session_attrs</>.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2017-01-24 [ba005f193] Allow password file name to be specified as a libpq conn
      -->
      <para>
       Allow <link linkend="libpq-connect-passfile">password file name</>
       to be specified as a libpq connection parameter (Julian Markwort)
      </para>

      <para>
       Previously this could only be specified via an environment variable.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-08-16 [a7b5573d6] Remove separate version numbering for ecpg preprocessor.
      -->
      <para>
       ecpg preprocessor version changed from 4.12 to 10 (Tom Lane)
      </para>

      <para>
       The ecpg version now matches the Postgres distribution version
       number.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>
   
   <sect3>
    <title>Client Applications</title>

    <sect4>
     <title><xref linkend="APP-PSQL"></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-03-30 [e984ef586] Support \if ... \elif ... \else ... \endif in psql scrip
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-04-02 [5dbc5da11] Fix behavior of psql's \p to agree with \g, \w, etc.
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-04-02 [68dba97a4] Document psql's behavior of recalling the previously exe
       -->
       <para>
        Add conditional branch support to <application>psql</> (Corey
        Huinker)
       </para>

       <para>
        The new syntax uses \if, \elif, \else, and \endif.  This is
        particularly helpful for scripting.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Stephen Frost <sfrost@snowman.net>
       2017-03-07 [b2678efd4] psql: Add \gx command
       -->
       <para>
        Add <application>psql</> \gx command to perform \g(execute)
        in expanded mode (\x) (Christoph Berg)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-11-03 [a0f357e57] psql: Split up "Modifiers" column in \d and \dD
       -->
       <para>
        Improve <application>psql</>'s \d (relation) and \dD (domain)
        commands to specify collation, nullable, and default in separate
        columns (Peter Eisentraut)
       </para>

       <para>
        Previous they were in a single "Modifiers" column.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-04-01 [f833c847b] Allow psql variable substitution to occur in backtick co
       -->
       <para>
        Expand <application>psql</> colon variables when used in
        backtick-executed contexts (Tom Lane)
       </para>

       <para>
        This is particularly useful for the new <application>psql</>
        conditional branch support commands.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-30 [511ae628f] Make psql reject attempts to set special variables to in
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-02-01 [86322dc7e] Improve psql's behavior for \set and \unset of its contr
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-02-02 [fd6cd6980] Clean up psql's behavior for a few more control variable
       -->
       <para>
        Prevent <application>psql</> special variables from being set to
        invalid values (Daniel V&eacute;rit&eacute;, Tom Lane)
       </para>

       <para>
        Previously setting <application>psql</> special variables
        to invalid values produced the default behavior.  \set and
        \unset of special variables now sets them to "on" and its
        default value, rather than a zero-length string and undefined.
        Also have \set always display values for <literal>FETCH_COUNT</>,
        <literal>HISTSIZE</>, and <literal>IGNOREEOF</>.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2016-08-18 [49917dbd7] Improve psql's tab completion for ALTER EXTENSION foo UP
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2016-08-18 [8019b5a89] Improve psql's tab completion for \l.
       Author: Kevin Grittner <kgrittn@postgresql.org>
       2016-09-01 [76f9dd4fa] Improve tab completion for BEGIN &amp; START|SET TRANSACTION
       Author: Kevin Grittner <kgrittn@postgresql.org>
       2016-09-11 [52803098a] psql tab completion for CREATE DATABASE ... TEMPLATE ...
       Author: Kevin Grittner <kgrittn@postgresql.org>
       2016-09-12 [63c1a8719] Fix recent commit for tab-completion of database templat
       Author: Robert Haas <rhaas@postgresql.org>
       2016-11-03 [1d15d0db5] psql: Tab-complete LOCK [TABLE] ... IN {ACCESS|ROW|SHARE
       Author: Kevin Grittner <kgrittn@postgresql.org>
       2016-11-04 [927d7bb6b] Improve tab completion for CREATE TRIGGER.
       Author: Robert Haas <rhaas@postgresql.org>
       2016-11-08 [577f0bdd2] psql: Tab completion for renaming enum values.
       Author: Peter Eisentraut <peter_e@gmx.net>
       2017-03-01 [b5a388392] psql: Add tab completion for DEALLOCATE
       Author: Peter Eisentraut <peter_e@gmx.net>
       2017-03-16 [d7d77f382] psql: Add completion for \help DROP|ALTER
       -->
       <para>
        Improve <application>psql</>'s tab completion (Jeff Janes,
        Ian Barwick, Andreas Karlsson, Sehrope Sarkuni, Thomas Munro,
        Kevin Grittner, Dagfinn Ilmari Manns&aring;ker)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><xref linkend="pgbench"></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Robert Haas <rhaas@postgresql.org>
       2016-11-09 [41124a91e] pgbench: Allow the transaction log file prefix to be cha
       -->
       <para>
        Add pgbench option <option>--log-prefix</> to control the log
        file prefix (Masahiko Sawada)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Tom Lane <tgl@sss.pgh.pa.us>
       2017-01-20 [cdc2a7047] Allow backslash line continuations in pgbench's meta com
       -->
       <para>
        Allow pgbench's meta commands to span multiple lines via a
        line-terminating backslash (Fabien Coelho)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Server Applications</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Magnus Hagander <magnus@hagander.net>
      2017-01-17 [cada1af31] Add compression support to pg_receivexlog
      -->
      <para>
       Add <link
       linkend="app-pgreceivewal"><application>pg_receivewal</></>
       option <option>-Z</>/<option>--compress</> to support compression
       (Michael Paquier)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Simon Riggs <simon@2ndQuadrant.com>
      2017-01-04 [7c030783a] Add pg_recvlogical \-\-endpos=LSN
      -->
      <para>
       Add <link
       linkend="app-pgrecvlogical"><application>pg_recvlogical</></> option
       (<option>--endpos</>) to specify the ending position (Craig Ringer)
      </para>

      <para>
       This complements the existing <option>--startpos</> option.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2016-10-19 [5d58c07a4] initdb pg_basebackup: Rename \-\-noxxx options to \-\-no-xxx
      -->
      <para>
       Rename <link linkend="APP-INITDB"><application>initdb</></>
       options <option>--noclean</> and <option>--nosync</> to be spelled
       <option>--no-clean</> and <option>--no-sync</> (Vik Fearing,
       Peter Eisentraut)
      </para>

      <para>
       The old spellings are still supported.
      </para>
     </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="APP-PGDUMP"><application>pg_dump</></>, <link linkend="APP-PG-DUMPALL"><application>pg_dumpall</></>.
     <link linkend="APP-PGRESTORE"><application>pg_restore</></></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-09-20 [46b55e7f8] pg_restore: Add -N option to exclude schemas
       -->
       <para>
        Allow <application>pg_restore</> to exclude schemas (Michael Banck)
       </para>

       <para>
        This added a new <option>-N</>/<option>--exclude-schema</> option.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Stephen Frost <sfrost@snowman.net>
       2016-11-29 [4fafa579b] Add \-\-no-blobs option to pg_dump
       -->
       <para>
        Add <option>--no-blobs</> option to
       <application>pg_dump</> (Guillaume Lelarge)
       </para>

       <para>
        This suppresses the dumping of large objects.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Simon Riggs <simon@2ndQuadrant.com>
       2017-03-07 [9a83d56b3] Allow pg_dumpall to dump roles w/o user passwords
       -->
       <para>
        Add <application>pg_dumpall</> option
        <option>--no-role-passwords</> to dump roles without user passwords
        (Robins Tharakan, Simon Riggs)
       </para>

       <para>
        This allows easier dumping for less-privileged users.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Andrew Dunstan <andrew@dunslane.net>
       2017-03-22 [96a7128b7] Sync pg_dump and pg_dumpall output
       -->
       <para>
        Issue fsync on the output files generated by
        <application>pg_dump</> and
       <application>pg_dumpall</> (Michael Paquier)
       </para>

       <para>
        This can be disabled with the <option>--no-sync</> option.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>
  
    <sect4>

    <title><xref linkend="app-pgbasebackup"></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Magnus Hagander <magnus@hagander.net>
       2016-10-23 [56c7d8d45] Allow pg_basebackup to stream transaction log in tar mod
       Author: Fujii Masao <fujii@postgresql.org>
       2016-12-21 [ecbdc4c55] Forbid invalid combination of options in pg_basebackup.
       -->
       <para>
        Allow <application>pg_basebackup</> to stream write-ahead log in
        tar mode (Magnus Hagander)
       </para>

       <para>
        The <acronym>WAL</> will be stored in a separate tar file from
        the base backup.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Magnus Hagander <magnus@hagander.net>
       2017-01-16 [e7b020f78] Make pg_basebackup use temporary replication slots
       -->
       <para>
        Make <application>pg_basebackup</> use temporary replication slots
        (Magnus Hagander)
       </para>

       <para>
        Temporary replication slots will be used by default when
        <application>pg_basebackup</> uses wal streaming with default
        options.
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-09-29 [bc34223bc] pg_basebackup pg_receivexlog: Issue fsync more carefully
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-09-29 [6ed2d8584] pg_basebackup: Add - option-->
       <para>
        Improve fsync handling of <application>pg_basebackup</> and
        <application>pg_receivewal</> (Michael Paquier)
       </para>

       <para>
        Also add <option>--nosync</> option to disable fsync.
       </para>
      </listitem>   

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-09-28 [6ad8ac602] Exclude additional directories in pg_basebackup
       -->
       <para>
        Improve <application>pg_basebackup</>'s handling of which
        directories to skip (David Steele)
       </para>

       <para>
        Also improve the documentation of skipped directories.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>
      
    <sect4>
     <title><application><xref linkend="app-pg-ctl"></></title>

     <itemizedlist>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-09-21 [e7010ce47] pg_ctl: Add wait option to promote action
       -->
       <para>
        Add wait option for <application><xref linkend="app-pg-ctl"></>'s
        promote operation (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-10-19 [0be22457d] pg_ctl: Add long options for -w and -W
       -->
       <para>
        Add long options for <application>pg_ctl</> wait (<option>--wait</>)
        and no-wait (<option>--no-wait</>) (Vik Fearing)
       </para>
      </listitem>

      <listitem>
       <!--
       Author: Peter Eisentraut <peter_e@gmx.net>
       2016-10-19 [caf936b09] pg_ctl: Add long option for -o
       -->
       <para>
        Add long options flag for <application>pg_ctl</>
        <literal>options</> (Peter Eisentraut)
       </para>

       <para>
        It is called <option>--options</>.
       </para>
      </listitem>

     </itemizedlist>
   
    </sect4>
  
   </sect3>

   <sect3>
    <title>Source Code</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-08-15 [ca9112a42] Stamp HEAD as 10devel.
      -->
      <para>
       New major version numbering (Peter Eisentraut, Tom Lane)
      </para>

      <para>
       Major versions will now increase just the first number, and minor
       releases will increase just the second number.  A third number
       will no longer be used in Postgres version numbers.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-23 [eccfef81e] ICU support
      -->
      <para>
       Allow the <link linkend="configure"><acronym>ICU</></> library to
       optionally be used for collation support (Peter Eisentraut)
      </para>

      <para>
       The <acronym>ICU</> library has versioning that allows detection
       of collation changes between versions.  It is enabled via configure
       option <option>--with-icu</>.  The default still uses the operating
       system's native collation library.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-11-04 [c8ead2a39] Provide DLLEXPORT markers for C functions via PG_FUNCTIO
      -->
      <para>
       Automatically mark all <link
       linkend="xfunc-c"><function>PG_FUNCTION_INFO_V1</></> functions
       as <literal>DLLEXPORT</>-ed on
      <systemitem class="osname">Windows</> (Laurenz Albe)
      </para>

      <para>
       If third-party code is using <literal>extern</> function
       declarations, they should also add <literal>DLLEXPORT</> markers
       to those declarations.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-12-02 [13e14a78e] Management of free memory pages.
      Author: Robert Haas <rhaas@postgresql.org>
      2016-12-02 [13df76a53] Introduce dynamic shared memory areas.
      Author: Robert Haas <rhaas@postgresql.org>
      2016-12-19 [e13029a5c] Provide a DSA area for all parallel queries.
      -->
      <para>
       Allow shared memory to be dynamically allocated (Thomas Munro,
       Robert Haas)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andres Freund <andres@anarazel.de>
      2017-02-27 [58b25e981] Add "Slab" MemoryContext implementation for efficient eq
      -->
      <para>
       Add slab-like memory allocator for efficient fixed-size allocations
       (Tomas Vondra)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-10-09 [ecb0d20a9] Use unnamed POSIX semaphores, if available, on Linux and
      -->
      <para>
       Use <acronym>POSIX</> semaphores rather than SysV semaphores
       on <systemitem class="osname">Linux</> and <systemitem
       class="osname">FreeBSD</> (Tom Lane)
      </para>

      <para>
       This avoids some limits on SysV semaphore usage.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andres Freund <andres@anarazel.de>
      2017-04-07 [e8fdbd58f] Improve 64bit atomics support.
      -->
      <para>
       Improve support for 64-bit atomics (Andres Freund)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andres Freund <andres@anarazel.de>
      2017-03-10 [f8f1430ae] Enable 64 bit atomics on ARM64.
      -->
      <para>
       Enable 64-bit atomic operations on <acronym>ARM64</> (Roman
       Shaposhnik)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2017-01-02 [1d63f7d2d] Use clock_gettime(), if available, in instr_time measure
      -->
      <para>
       Switch to using <function>clock_gettime()</>, if available, for
       duration measurements (Tom Lane)
      </para>

      <para>
      <function>gettimeofday()</> is used if <function>clock_gettime()</>
      is not available.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
      2016-12-05 [fe0a0b599] Replace PostmasterRandom() with a stronger source, secon
      -->
      <para>
       Add more robust random number generators to be used for
       cryptographic secure uses (Magnus Hagander, Michael Paquier,
       Heikki Linnakangas)
      </para>

      <para>
       If no strong random number generator can be found, configure
       will fail unless the <link linkend="configure">configure</>
       <option>--disable-strong-random</> is used.  However, with this
       option, pgcrypto functions requiring a strong random number
       generator will be disabled.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2016-08-18 [e8306745e] doc: Speed up XSLT builds
      Author: Peter Eisentraut <peter_e@gmx.net>
      2016-08-24 [0e4cc1fc5] doc: Fix XSLT speedup with older upstream stylesheet ver
      -->
      <para>
       Overhaul documentation <link linkend="docguide-toolsets">build
       process</> (Alexander Lakhin, Alexander Law)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-04-06 [510074f9f] Remove use of Jade and DSSSL
      -->
      <para>
       Use <acronym>XSLT</> to build the Postgres documentation (Peter
       Eisentraut)
      </para>

      <para>
       Previously <application>Jade</>, <acronym>DSSSL,</> and
       <application>JadeTex</> were used.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2016-11-15 [e36ddab11] Build HTML documentation using XSLT stylesheets by defau
      -->
      <para>
       Build <acronym>HTML</> documentation using <acronym>XSLT</>
       stylesheets by default (Peter Eisentraut)
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

   <sect3>
    <title>Additional Modules</title>

    <itemizedlist>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-09-29 [8e91e12bc] Allow contrib/file_fdw to read from a program, like COPY
      -->
      <para>
       Allow <link linkend="file-fdw"><application>file_fdw</></> to read
       from program output as well as files (Corey Huinker, Adam Gomaa)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-10-21 [7012b132d] postgres_fdw: Push down aggregates to remote servers.
      -->
      <para>
       Push aggregates to foreign data wrapper servers, where possible
       (Jeevan Chalke, Ashutosh Bapat)
      </para>

      <para>
       This reduces the amount of data that must be passed
       from the foreign data wrapper server, and offloads
       aggregate computation from the requesting server.  The <link
       linkend="postgres-fdw"><application>postgres_fdw</></> is able to
       perform this optimization.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2017-03-16 [b30fb56b0] postgres_fdw: Push down <literal>FULL JOIN</>s with restriction clau
      -->
      <para>
       Allow push down of <literal>FULL JOIN</> queries containing
       subqueries in the
      <literal>FROM</> clause to foreign servers (Etsuro Fujita)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
      2016-08-26 [ae025a159] Support OID system column in postgres_fdw.
      -->
      <para>
       Properly support <type>OID</> columns in
       <application>postgres_fdw</> tables (Etsuro Fujita)
      </para>

      <para>
       Previously <type>OID</> columns always returned zeros.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andrew Dunstan <andrew@dunslane.net>
      2017-03-21 [f7946a92b] Add btree_gist support for enum types.
      -->
      <para>
       Allow <link linkend="btree-gist"><application>btree_gist</></>
       and <link linkend="btree-gin"><application>btree_gin</></> to
       index enum types (Andrew Dunstan)
      </para>

      <para>
       This allows enums to be used in exclusion constraints.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-11-29 [11da83a0e] Add uuid to the set of types supported by contrib/btree_
      -->
      <para>
       Add indexing support to <application>btree_gist</> for the
       <type>UUID</> data type (Paul Jungwirth)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Andres Freund <andres@anarazel.de>
      2017-03-09 [3717dc149] Add amcheck extension to contrib.
      -->
      <para>
       Add <link linkend="amcheck"><application>amcheck</></> which can
       check the validity of btree indexes (Peter Geoghegan)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2017-03-27 [a6f22e835] Show ignored constants as "$N" rather than "?" in pg_sta
      -->
      <para>
       Show ignored constants as <literal>$N</> rather than <literal>?</>
       in
      <link
      linkend="pgstatstatements"><application>pg_stat_statements</></>
      (Lukas Fittl)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Tom Lane <tgl@sss.pgh.pa.us>
      2016-09-27 [f31a931fa] Improve contrib/cube's handling of zero-D cubes, infinit
      -->
      <para>
       Improve <link linkend="cube"><application>cube</></>'s handling
       of zero-dimensional cubes (Tom Lane)
      </para>

      <para>
       This also improves handling of <literal>infinite</> and
       <literal>NaN</> values.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Heikki Linnakangas <heikki.linnakangas@iki.fi>
      2016-09-29 [6e654546f] Don't bother to lock bufmgr partitions in pg_buffercache
      -->
      <para>
       Allow <link
       linkend="pgbuffercache"><application>pg_buffercache</></> to run
       with fewer locks (Ivan Kartyshov)
      </para>

      <para>
       This allows it be less disruptive when run on production systems.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2017-02-03 [e759854a0] pgstattuple: Add pgstathashindex.
      -->
      <para>
       Add <function>pgstathashindex()</> function to <link
       linkend="pgstattuple"><application>pgstattuple</></> to view hash
       index statistics (Ashutosh Sharma)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Stephen Frost <sfrost@snowman.net>
      2016-09-29 [fd321a1df] Remove superuser checks in pgstattuple
      -->
      <para>
       Allow <link linkend="pgstattuple"><application>pgstattuple</></>
       to use <command>GRANT</> permissions (Stephen Frost)
      </para>

      <para>
       This allows non-superusers to run these functions if permissions
       allow.
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2016-10-28 [d4b5d4cad] pgstattuple: Don't take heavyweight locks when examining
      -->
      <para>
       Reduce locking when <link
       linkend="pgstattuple"><application>pgstattuple</></> examines hash
       indexes (Amit Kapila)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-03-17 [fef2bcdcb] pageinspect: Add page_checksum function
      -->
      <para>
       Add <function>page_checksum()</> function to <link
       linkend="pageinspect"><application>pageinspect</></> (Tomas Vondra)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Robert Haas <rhaas@postgresql.org>
      2017-02-02 [08bf6e529] pageinspect: Support hash indexes.
      -->
      <para>
       Add hash index support to <link
       linkend="pageinspect"><application>pageinspect</></> (Jesper
       Pedersen, Ashutosh Sharma)
      </para>
     </listitem>

     <listitem>
      <!--
      Author: Peter Eisentraut <peter_e@gmx.net>
      2017-04-04 [193f5f9e9] pageinspect: Add bt_page_items function with bytea argum
      -->
      <para>
       Add <link linkend="pageinspect"><application>pageinspect</></>
       function <function>bt_page_items()</> to print page items from a
       page image (Tomas Vondra)
      </para>

      <para>
       Previously only block numbers were supported.
      </para>
     </listitem>

    </itemizedlist>

   </sect3>

  </sect2>

 </sect1>
