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 <sect1 id="release-9-3">
  <title>Release 9.3</title>

  <note>
   <title>Release Date</title>
   <simpara>2013-XX-XX, CURRENT AS OF 2013-05-03</simpara>
  </note>

  <sect2>
   <title>Overview</title>

   <para>
    Major enhancements include:
   </para>

    <!-- This list duplicates items below, but without authors or details-->

   <para>
    ADD HERE ...
   </para>

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

  </sect2>

  <sect2>

  <title>Migration to Version 9.3</title>

   <para>
    A dump/restore using <link
    linkend="APP-PG-DUMPALL"><application>pg_dumpall</></link>, or use
    of <link linkend="pgupgrade"><application>pg_upgrade</></link>, is
    required for those wishing to migrate data from any previous release.
   </para>

   <para>
    Version 9.3 contains a number of changes that may affect compatibility
    with previous releases.  Observe the following incompatibilities:
   </para>

   <sect3>
    <title>Server Settings</title>

     <itemizedlist>

      <listitem>
       <para>
        Rename <varname>replication_timeout</> to <link
        linkend="guc-wal-sender-timeout"><varname>wal_sender_timeout</></link>
        (Amit Kapila)
       </para>

       <para>
        This setting controls the <link
        linkend="wal"><acronym>WAL</></link> sender timeout.
       </para>
      </listitem>

      <listitem>
       <para>
        Require superuser privileges to set <link
        linkend="guc-commit-delay"><varname>commit_delay</></link>
        because it can now potentially delay other sessions (Simon Riggs)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow in-memory sorts to use their full memory allocation (Jeff Janes)
       </para>

       <para>
        Users who have set <link
        linkend="guc-work-mem"><varname>work_mem</></link> based on the
        previous behavior should revisit that setting.
       </para>
      </listitem>

     </itemizedlist>

   </sect3>

   <sect3>
    <title>Other</title>

     <itemizedlist>

      <listitem>
       <para>
        Throw an error if expiring tuple is again updated or deleted (Kevin Grittner)
        DETAILS?
       </para>
      </listitem>

      <listitem>
       <para>
        Change <link linkend="SQL-CREATETABLE"><literal>ON UPDATE
        SET NULL/SET DEFAULT</></link> foreign key actions to affect
        all referenced columns, not just those referenced in the
        <command>UPDATE</> (Tom Lane)
       </para>

       <para>
        Previously only columns referenced in the <command>UPDATE</> were
        set to null or <literal>DEFAULT</>.
       </para>
      </listitem>

      <listitem>
       <para>
        Internally store default foreign key matches (non-<literal>FULL</>,
        non-<literal>PARTIAL</>) as <quote>simple</> (Tom Lane)
       </para>

       <para>
        These were previously stored as "&lt;unspecified&gt;".
        This changes the value stored in system column <link
        linkend="catalog-pg-constraint"><structname>pg_constraint.confmatchtype</></link>.
       </para>
      </listitem>

      <listitem>
       <para>
        Store <link linkend="wal"><acronym>WAL</></link> in a continuous
        stream, rather than skipping the last 16MB segment every 4GB
        (Heikki Linnakangas)
       </para>

       <para>
        Previously, <acronym>WAL</> files with names ending in <literal>FF</>
        were not used.  If you have <acronym>WAL</> backup or restore scripts
        that took that skipping into account, they will need to be adjusted.
       </para>
      </listitem>

     </itemizedlist>

   </sect3>

  </sect2>

  <sect2>
   <title>Changes</title>

   <para>
    Below you will find a detailed account of the changes between
    <productname>PostgreSQL</productname> 9.3 and the previous major
    release.
   </para>

   <sect3>
    <title>Server</title>

    <sect4>
     <title>Locking</title>

     <itemizedlist>

      <listitem>
       <para>
        Prevent non-key-field row updates from locking foreign key rows
        (&Aacute;lvaro Herrera, Noah Misch, Andres Freund, Alexander
        Shulgin, Marti Raudsepp)
       </para>

       <para>
        This improves concurrency and reduces the probability of deadlocks.
        <command>UPDATE</>s on non-key columns use the new <command>SELECT
        FOR NO KEY UPDATE</> lock type, and foreign key checks use the
        new <command>SELECT FOR KEY SHARE</> lock mode.
       </para>
      </listitem>

      <listitem>
       <para>
        Add configuration variable <link
        linkend="guc-lock-timeout"><varname>lock_timeout</></link> to limit
        lock wait duration (Zolt&aacute;n B&ouml;sz&ouml;rm&eacute;nyi)
       </para>
      </listitem>

      <listitem>
       <para>
        Add cache of local locks (Jeff Janes)
       </para>

       <para>
        This speeds lock release at statement completion in
        transactions that hold many locks; it is particularly useful
        for <application>pg_dump</> and the restoration of such dumps.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Indexes</title>

     <itemizedlist>

      <listitem>
       <para>
        Add <link linkend="rangetypes-indexing"><type>SP-GiST</></link>
        support for range data types (Alexander Korotkov)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow unlogged <link linkend="SPGiST"><type>GiST</></link> indexes
        (Jeevan Chalke)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve concurrency of hash indexes (Robert Haas)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Optimizer</title>

     <itemizedlist>

      <listitem>
       <para>
        Collect and use histograms for <link linkend="rangetypes">range
        types</link> (Alexander Korotkov)
       </para>
      </listitem>

      <listitem>
       <para>
        Reduce optimizer overhead by discarding plans with unneeded cheaper
        startup costs (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve optimizer cost estimation for index access (Tom Lane)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

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

     <itemizedlist>

      <listitem>
       <para>
        Add <link linkend="SQL-COPY"><command>COPY FREEZE</></link>
        option to avoid the overhead of marking tuples as committed later
        (Simon Riggs, Jeff Davis)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve performance of <link
        linkend="datatype-numeric"><type>NUMERIC</></link> calculations
        (Kyotaro Horiguchi)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve grouping of sessions waiting for <link
        linkend="guc-commit-delay"><varname>commit_delay</></link>
        (Peter Geoghegan)
       </para>

       <para>
        This improves the usefulness and behavior of
        <varname>commit_delay</>.
       </para>
      </listitem>

      <listitem>
       <para>
        Improve performance for transactions creating, rebuilding, or
        dropping many relations (Jeff Janes, Tomas Vondra)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve performance of the <link
        linkend="SQL-CREATETABLE"><command>CREATE TEMPORARY TABLE ... ON
        COMMIT DELETE ROWS</></link> clause by only issuing delete if
        the temporary table was accessed (Heikki Linnakangas)
       </para>
      </listitem>

      <listitem>
       <para>
        Have vacuum recheck visibility after it has removed expired tuples
        (Pavan Deolasee)
       </para>

       <para>
        This increases the chance of a page being marked as all-visible.
       </para>
      </listitem>

      <listitem>
       <para>
        Split the <link
        linkend="guc-stats-temp-directory"><filename>pg_stat_tmp</></link>
        statistics file into per-database and global files (Tomas Vondra)
       </para>

       <para>
        This reduces the I/O overhead for statistics tracking.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Monitoring</title>

     <itemizedlist>

      <listitem>
       <para>
        Add optional ability to <link
        linkend="app-initdb-data-checksums">checksum</link> data pages and
        report corruption (Simon Riggs, Jeff Davis, Greg Smith, Ants Aasma)
       </para>

       <para>
        The checksum option can be set during <link
        linkend="APP-INITDB">initdb</link>.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <link
        linkend="functions-admin-signal-table"><function>pg_terminate_backend()</></link>
        to terminate other backends with the same role (Dan Farina)
       </para>

       <para>
        Previously, only superusers could terminate other sessions.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow the <link
        linkend="runtime-config-statistics-collector">statistics
        collector</link> to operate properly in cases where the system
        clock goes backwards (Tom Lane)
       </para>

       <para>
        Previously statistics collection would stop until the time again
        reached the previously-stored latest time.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Authentication</title>

     <itemizedlist>

      <listitem>
       <para>
        Improve <link linkend="auth-ldap"><acronym>LDAP</></link> error
        reporting and documentation (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Add support for <acronym>LDAP</> authentication to be specified
        in <acronym>URL</> format (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Change the <link
        linkend="guc-ssl-ciphers"><varname>ssl_ciphers</></link> parameter
        to start with <literal>DEFAULT</>, rather than <literal>ALL</>,
        then remove insecure ciphers (Magnus Hagander)
       </para>

       <para>
        It is assumed <literal>DEFAULT</> is more appropriate cipher set.
       </para>
      </listitem>

      <listitem>
       <para>
        Parse and load <link
        linkend="auth-username-maps"><filename>pg_ident.conf</></link>
        once, not during each connection (Amit Kapila)
       </para>

       <para>
        This is similar to how <link
        linkend="auth-pg-hba-conf"><filename>pg_hba.conf</></link>
        is processed.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Server Settings</title>

     <itemizedlist>

      <listitem>
       <para>
        Dramatically reduce System V <link linkend="sysvipc">shared
        memory</link> requirements (Robert Haas)
       </para>

       <para>
        Instead, on Unix-like systems, <function>mmap()</> is used for
        shared memory.  For most users, this will eliminate the need to
        adjust kernel parameters for shared memory.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow the postmaster to listen on multiple Unix-domain sockets
        (Honza Hor&aacute;k)
       </para>

       <para>
        The configuration parameter
        <varname>unix_socket_directory</> is replaced by <link
        linkend="guc-unix-socket-directories"><varname>unix_socket_directories</></link>,
        which accepts a list of directories.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow a directory of configuration files to be processed (Magnus
        Hagander, Greg Smith, Selena Deckelmann)
       </para>

       <para>
        Such a directory is specified with <link
        linkend="config-includes"><varname>include_dir</></link> in the server
        configuration file.
       </para>
      </listitem>

      <listitem>
       <para>
        Increase the maximum <link
        linkend="APP-INITDB">initdb</link>-configured value for <link
        linkend="guc-shared-buffers"><varname>shared_buffers</></link>
        to 128MB (Robert Haas)
       </para>

       <para>
        This is the maximum value that initdb will attempt to set in <link
        linkend="config-setting-configuration-file"><filename>postgresql.conf</></link>;
        the previous maximum was 32MB.
       </para>
      </listitem>

      <listitem>
       <para>
        Remove the <link linkend="guc-external-pid-file">external
        <acronym>PID</> file</link> on postmaster exit (Peter Eisentraut)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

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

     <itemizedlist>

      <listitem>
       <para>
        Allow a streaming replication standby to <link
        linkend="protocol-replication">follow a timeline switch</link>
        (Heikki Linnakangas)
       </para>

       <para>
        This allows streaming standbys to feed from newly-promoted slaves.
        Previously slaves required access to a <acronym>WAL</> archive directory to
        accomplish this.
       </para>
      </listitem>

      <listitem>
       <para>
        Add <acronym>SQL</> functions <link
        linkend="functions-admin-backup"><function>pg_is_in_backup()</></link>
        and <link
        linkend="functions-admin-backup"><function>pg_backup_start_time()</></link>
        (Gilles Darold)
       </para>

       <para>
        These functions report the status of base backups.
       </para>
      </listitem>

      <listitem>
       <para>
        Improve performance of streaming log shipping with <link
        linkend="guc-synchronous-commit"><varname>synchronous_commit</></link>
        disabled (Andres Freund)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow much faster promotion of a streaming standby to primary (Simon
        Riggs, Kyotaro Horiguchi)
       </para>
      </listitem>

      <listitem>
       <para>
        Add the last checkpoint's redo location to <link
        linkend="APP-PGCONTROLDATA"><application>pg_controldata</></link>'s
        output (Fujii Masao)
       </para>

       <para>
        This information is useful for determining the <acronym>WAL</>
        files needed for restore.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow tools like <link
        linkend="app-pgreceivexlog"><application>pg_receivexlog</></link>
        to run on computers with different architectures (Heikki
        Linnakangas)
       </para>

       <para>
        WAL files can still only be replayed on servers with the same
        architecture as the primary; but they can now be transmitted to and
        stored on machines of any architecture, since the
        streaming replication protocol is now machine-independent.
       </para>
      </listitem>

      <listitem>
       <para>
        Have <link
        linkend="app-pgbasebackup"><application>pg_basebackup</></link>
        <option>--write-recovery-conf</> output a
        minimal <filename>recovery.conf</> (Zolt&aacute;n
        B&ouml;sz&ouml;rm&eacute;nyi, Magnus Hagander)
       </para>

       <para>
        This simplifies setting up a standby server.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <link
        linkend="app-pgreceivexlog"><application>pg_receivexlog</></link>
        and <link
        linkend="app-pgbasebackup"><application>pg_basebackup</></link>
        <option>--xlog-method</> to handle streaming timeline switches
        (Heikki Linnakangas)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link
        linkend="guc-wal-receiver-timeout"><varname>wal_receiver_timeout</></link>
        parameter to control the <acronym>WAL</> receiver timeout
        (Amit Kapila)
       </para>

       <para>
        This allows more rapid detection of connection failure.
       </para>
      </listitem>

     </itemizedlist>

    <sect4>
     <title><link linkend="wal">Write-Ahead Log</link>
     (<acronym>WAL</>)</title>

     <itemizedlist>

      <listitem>
       <para>
        Change the <acronym>WAL</> record format to allow splitting the record header
        across pages (Heikki Linnakangas)
       </para>

       <para>
        The new format is slightly more compact, and is more efficient to
        write.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Queries</title>

     <itemizedlist>

      <listitem>
       <para>
        Implement <acronym>SQL</>-standard <link
        linkend="queries-lateral"><literal>LATERAL</></link> option for
        <literal>FROM</>-clause subqueries and function calls (Tom Lane)
       </para>

       <para>
        This feature allows subqueries and functions in <literal>FROM</> to
        reference columns from other tables in the <literal>FROM</>
        clause. The <literal>LATERAL</> keyword is optional for functions.
       </para>
      </listitem>

      <listitem>
       <para>
        Add support for piping <link
        linkend="SQL-COPY"><command>COPY</></link> and <link
        linkend="APP-PSQL"><application>psql</></link> <command>\copy</>
        to/from an external program (Etsuro Fujita)
       </para>
      </listitem>

     </itemizedlist>

   </sect3>

   <sect3>
    <title>Object Manipulation</title>

     <itemizedlist>

      <listitem>
       <para>
        Add support for <link linkend="event-triggers">event triggers</link>
        (Dimitri Fontaine, Robert Haas, &Aacute;lvaro Herrera)
       </para>

       <para>
        This allows server-side functions written in event-enabled
        languages, e.g. C, PL/pgSQL, to be called when DDL commands
        are run.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow a multirow <link
        linkend="SQL-VALUES"><literal>VALUES</></link> clause in a rule
        to reference <literal>OLD</>/<literal>NEW</> (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="SQL-CREATESCHEMA"><command>CREATE SCHEMA ... IF
        NOT EXISTS</></link> clause (Fabr&iacute;zio de Royes Mello)
       </para>
      </listitem>

      <listitem>
       <para>
        Have <link linkend="SQL-REASSIGN-OWNED"><command>REASSIGN
        OWNED</></link> also change ownership of shared objects
        (&Aacute;lvaro Herrera)
       </para>
      </listitem>

     </itemizedlist>

    <sect4>
     <title><link linkend="SQL-CREATETABLE"><command>CREATE TABLE</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Suppress messages about implicit index and sequence creation
        (Robert Haas)
       </para>

       <para>
        These messages now appear at <literal>DEBUG1</> verbosity, so that
        they will not be shown by default.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <link linkend="SQL-DROPTABLE"><command>DROP TABLE IF
        EXISTS</></link> to succeed when a non-existent schema is specified
        in the table name (Bruce Momjian)
       </para>

       <para>
         Previously, it threw an error if the schema did not exist.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title>Constraints</title>

     <itemizedlist>

      <listitem>
       <para>
        Provide clients with <link
        linkend="libpq-pqresulterrorfield">constraint violation details</link>
        as separate fields (Pavel Stehule)
       </para>

       <para>
        This allows clients to retrieve table, column, data type, or constraint
        name error details.  Previously such information had to be extracted from
        error strings.  Client library support is required to access these
        fields.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><command>ALTER</></title>

     <itemizedlist>

      <listitem>
       <para>
        Support <literal>IF NOT EXISTS</> option in <link
        linkend="SQL-ALTERTYPE"><command>ALTER TYPE ... ADD VALUE</></link>
        (Andrew Dunstan)
       </para>

       <para>
        This is useful for conditionally adding values to enumerated types.
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="SQL-ALTERROLE"><command>ALTER ROLE ALL
        SET</></link> to add settings to all users (Peter Eisentraut)
       </para>

       <para>
        This allows settings to apply to all users in all databases. <link
        linkend="SQL-ALTERDATABASE"><command>ALTER DATABASE SET</></link>
        already allowed addition of settings for all users in a single
        database.  <filename>postgresql.conf</> has a similar effect.
       </para>
      </listitem>

      <listitem>
       <para>
        Add support for <link linkend="SQL-ALTERRULE"><command>ALTER RULE
        ... RENAME</></link> (Ali Dar)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><link linkend="rules-views"><command>VIEWs</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Add <link linkend="SQL-CREATEMATERIALIZEDVIEW">materialized
        views</link> (Kevin Grittner)
       </para>

       <para>
        Unlike ordinary views, where the base tables are read on every access,
        materialized views create physical tables at creation or refresh time.
        Access to the materialized view then reads from its physical
        table. There is not yet any facility for incrementally refreshing
        materialized views or auto-accessing them via base table access.
       </para>
      </listitem>

      <listitem>
       <para>
        Make simple views <link
        linkend="SQL-CREATEVIEW-updatable-views">auto-updatable</link>
        (Dean Rasheed)
       </para>

       <para>
        Simple views that reference some or all columns from a
        single base table are now updatable by default. More
        complex views can be made updatable using <link
        linkend="SQL-CREATETRIGGER"><literal>INSTEAD OF</></link> triggers
        or <link linkend="SQL-CREATERULE"><literal>INSTEAD</></link> rules.
       </para>
      </listitem>

      <listitem>
       <para>
        Improve view/rule printing code to handle cases where referenced
        tables are renamed, or columns are renamed, added, or dropped
        (Tom Lane)
       </para>

       <para>
        Table and column renamings can produce cases where, if we merely
        substitute the new name into the original text of a rule or view, the
        result is ambiguous.  This patch fixes the rule-dumping code to insert
        table and column aliases if needed to preserve the original semantics.
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="SQL-CREATEVIEW"><command>CREATE RECURSIVE
        VIEW</></link> syntax (Peter Eisentraut)
       </para>

       <para>
        Internally this is translated into <command>CREATE VIEW ... WITH
        RECURSIVE ...</>.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

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

    <itemizedlist>

      <listitem>
       <para>
        Increase the maximum length of <link linkend="lo-open">large
        objects</link> from 2GB to 4TB (Nozomi Anzai, Yugo Nagata)
       </para>

       <para>
        This change includes new libpq and server-side 64-bit-capable
        large object access functions.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow text <link linkend="datatype-timezones">timezone
        designations</link>, e.g. <quote>America/Chicago</> when using
        the <acronym>ISO</> <quote>T</> <type>timestamptz</type> format (Bruce Momjian)
       </para>
      </listitem>

    </itemizedlist>

   <sect4>
    <title><link linkend="datatype-json"><type>JSON</></link></title>

    <itemizedlist>

      <listitem>
       <para>
        Add <link linkend="functions-json">operators and functions</link>
        to extract values from <type>JSON</> data strings (Andrew Dunstan)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <type>JSON</> data strings to be <link
        linkend="functions-json-table">converted into records</link>
        (Andrew Dunstan)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="functions-json-table">functions</link>
        to convert values, records, and hstore data to <type>JSON</>
        (Andrew Dunstan)
       </para>
      </listitem>

    </itemizedlist>

   </sect4>

   </sect3>


   <sect3>
    <title>Functions</title>

     <itemizedlist>

      <listitem>
       <para>
        Add <link
        linkend="array-functions-table"><function>array_remove()</></link>
        and <link
        linkend="array-functions-table"><function>array_replace()</></link>
        functions (Marco Nenciarini, Gabriele Bartolini)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <link
        linkend="functions-string-other"><function>concat()</></link>
        and <link
        linkend="functions-string-format"><function>format()</></link>
        to properly expand <literal>VARIADIC</>-labeled arguments
        (Pavel Stehule)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <link
        linkend="functions-string-format"><function>format()</></link>
        to handle field width and left/right alignment (Pavel Stehule)
       </para>
      </listitem>

      <listitem>
       <para>
        Have <link
        linkend="functions-formatting-table"><function>to_char()</></link>,
        <link
        linkend="functions-formatting-table"><function>to_date()</></link>,
        and <link
        linkend="functions-formatting-table"><function>to_timestamp()</></link>
        properly handle negative century designations (<literal>CC</>)
        (Bruce Momjian)
       </para>

       <para>
        Previously the behavior was either wrong or inconsistent
        with positive/<acronym>AD</> handling, e.g. format mask
        <quote>IYYY-IW-DY</>.
       </para>
      </listitem>

      <listitem>
       <para>
        Have <link
        linkend="functions-formatting-table"><function>to_date()</></link>
        and <link
        linkend="functions-formatting-table"><function>to_timestamp()</></link>
        return proper results when mixing <acronym>ISO</> and Gregorian
        week/day designations (Bruce Momjian)
       </para>
      </listitem>

      <listitem>
       <para>
        Cause <link
        linkend="functions-info-catalog-table"><function>pg_get_viewdef()</></link>
        to start a new line by default after each <link
        linkend="SQL-SELECT"><command>SELECT</></link> target list entry and
        <literal>FROM</> entry (Marko Tiikkaja)
       </para>

       <para>
        This reduces line length in view printing, for instance in <link
        linkend="APP-PGDUMP"><application>pg_dump</></link> output.
       </para>
      </listitem>

      <listitem>
       <para>
        Fix <function>map_sql_value_to_xml_value()</> to print values of
        domain types the same way their base type would be printed
        (Pavel Stehule)
       </para>

       <para>
        There are special formatting rules for certain built-in types such as
        <type>boolean</>; these rules now also apply to domains over these
        types.
       </para>
      </listitem>

      <listitem>
       <para>
        Force cached plans to be replanned if the <link
        linkend="guc-search-path"><varname>search_path</></link> changes
        (Tom Lane)
       </para>

       <para>
        Previously cached plans already generated in the current session
        ignored <varname>search_path</> changes.
       </para>
      </listitem>

     </itemizedlist>

   </sect3>

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

     <itemizedlist>

      <listitem>
       <para>
        Allow <link linkend="spi-spi-execute"><acronym>SPI</></link>
        functions to access the number of rows processed by
        <link linkend="SQL-COPY"><command>COPY</></link> (Pavel Stehule)
       </para>
      </listitem>

     </itemizedlist>

    <sect4>
     <title><link linkend="plpgsql">PL/pgSQL</link> Server-Side Language</title>

     <itemizedlist>

      <listitem>
       <para>
        Allow PL/pgSQL to use <literal>RETURN</> with a composite-type
        expression (Asif Rehman)
       </para>

       <para>
        Previously, in a function returning a composite type,
        <literal>RETURN</> could only reference a variable of that type.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow PL/pgSQL to access the number of rows processed by
        <link linkend="SQL-COPY"><command>COPY</></link> (Pavel Stehule)
       </para>

       <para>
        The command is <link
        linkend="plpgsql-statements-diagnostics"><command>GET DIAGNOSTICS
        x = ROW_COUNT</></link>.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow greater flexibility in where keywords can be used in PL/pgSQL (Tom Lane)
       </para>
      </listitem>

    </itemizedlist>

    </sect4>

    <sect4>
     <title><link linkend="plpython">PL/Python</link> Server-Side Language</title>

     <itemizedlist>

      <listitem>
       <para>
        Add PL/Python result object string handler (Peter Eisentraut)
       </para>

       <para>
        This allows <literal>plpy.debug(rv)</literal> to output something reasonable.
       </para>
      </listitem>

      <listitem>
       <para>
        Make PL/Python convert OID values to a proper Python numeric type
        (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Handle <link linkend="spi"><acronym>SPI</></link> errors raised
        explicitly (with PL/Python's <literal>RAISE</>) the same as
        internal <acronym>SPI</> errors (Oskari Saarenmaa and Jan Urbanski)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

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

    <itemizedlist>

      <listitem>
       <para>
        Add command-line utility <link
        linkend="app-pg-isready"><application>pg_isready</></link> to
        check if the server is ready to accept connections (Phil Sorber)
       </para>
      </listitem>

      <listitem>
       <para>
        Support multiple <option>--table</> arguments for <link
        linkend="APP-PGRESTORE"><application>pg_restore</></link>,
        <link linkend="APP-CLUSTERDB"><application>clusterdb</></link>,
        <link linkend="APP-REINDEXDB"><application>reindexdb</></link>,
        and <link linkend="APP-VACUUMDB"><application>vacuumdb</></link>
        (Josh Kupershmidt)
       </para>

       <para>
        This is similar to the <link
        linkend="APP-PGDUMP"><application>pg_dump</></link> <option>--table</>
        option.
       </para>
      </listitem>

      <listitem>
       <para>
        Add <option>--dbname</> option to <link
        linkend="APP-PG-DUMPALL"><application>pg_dumpall</></link>, <link
        linkend="app-pgbasebackup"><application>pg_basebackup</></link>, and
        <link
        linkend="app-pgreceivexlog"><application>pg_receivexlog</></link>
        to specify the connection string (Amit Kapila)
       </para>
      </listitem>

      <listitem>
       <para>
        Add libpq function <link
        linkend="libpq-pqconninfo"><function>PQconninfo()</></link>
        to return connection information (Zolt&aacute;n
        B&ouml;sz&ouml;rm&eacute;nyi, Magnus Hagander)
       </para>
      </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="APP-PSQL"><application>psql</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Adjust function cost settings so <application>psql</> tab
        completion and pattern searching is more efficient (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <application>psql</> tab completion coverage (Jeff Janes,
        Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow the <application>psql</> <option>--single-transaction</> mode to work when
        reading from standard input (Fabien Coelho, Robert Haas)
       </para>

       <para>
        Previously this option only worked when reading from a file.
       </para>
      </listitem>

      <listitem>
       <para>
        Remove <application>psql</> warning when connecting to an older
        server (Peter Eisentraut)
       </para>

       <para>
        The warning when connecting to a newer server was retained.
       </para>
      </listitem>

     </itemizedlist>

    <sect5>
     <title><link linkend="R2-APP-PSQL-4">Backslash Commands</link></title>

     <itemizedlist>

      <listitem>
       <para>
        Add <application>psql</> <command>\watch</> command to repeatedly
        execute commands (Will Leinweber)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <application>psql</> command <command>\gset</> to store query
        results in <application>psql</> variables (Pavel Stehule)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <acronym>SSL</> information to <application>psql</>'s
        <command>\conninfo</> command (Alastair Turner)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <quote>Security</> label to <application>psql</> <command>\df+</>
        output (Jon Erdman)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <application>psql</> <command>\l</> to accept a database
        name pattern (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        In <application>psql</>, do not allow <command>\connect</> to
        use defaults if there is no active connection (Bruce Momjian)
       </para>

       <para>
        This might be the case if the server had crashed.
       </para>
      </listitem>

      <listitem>
       <para>
        Properly reset state if the SQL command executed with
        <application>psql</>'s <quote>\g file</> fails (Tom Lane)
       </para>

       <para>
        Previously, the output from subsequent SQL commands would unexpectedly
        continue to go to the same file.
       </para>
      </listitem>

     </itemizedlist>

    </sect5>

    <sect5>
     <title>Output</title>

     <itemizedlist>

      <listitem>
       <para>
        Add a <literal>latex-longtable</> output format to
        <application>psql</> (Bruce Momjian)
       </para>

       <para>
        This format allows tables to span multiple pages.
       </para>
      </listitem>

      <listitem>
       <para>
        Add a <literal>border=3</> output mode to the <application>psql</>
        <literal>latex</> format (Bruce Momjian)
       </para>
      </listitem>

      <listitem>
       <para>
        In <application>psql</> tuples-only and expanded modes, no longer
        output <quote>(No rows)</> (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        In <application>psql</>, no longer print an empty line for
        unaligned, expanded output for zero rows (Peter Eisentraut)
       </para>
      </listitem>

     </itemizedlist>

    </sect5>

    </sect4>

    <sect4>
     <title><link linkend="APP-PGDUMP"><application>pg_dump</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Add <application>pg_dump</> <option>--jobs</> option to dump tables in
        parallel (Joachim Wieland)
       </para>
      </listitem>

      <listitem>
       <para>
        Have <application>pg_dump</> output functions in a more predictable
        order (Joel Jacobson)
       </para>
      </listitem>

      <listitem>
       <para>
        Fix tar files emitted by <application>pg_dump</> and <link
        linkend="app-pgbasebackup"><application>pg_basebackup</></link>
        to be <acronym>POSIX</> conformant (Brian Weaver, Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <option>--dbname</> option to <application>pg_dump</>, for
        consistency with other client commands (Heikki Linnakangas)
       </para>

       <para>
        The database name could already be supplied last without a flag.
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><link linkend="APP-INITDB"><application>initdb</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Have initdb fsync the newly created data directory (Jeff Davis)
       </para>

       <para>
        This can be disabled by using <option>--nosync</>.
       </para>
      </listitem>

      <listitem>
       <para>
        Add initdb <option>--sync-only</> option to sync the data directory to durable
        storage (Bruce Momjian)
       </para>

       <para>
        This is used by <link
        linkend="pgupgrade"><application>pg_upgrade</></link>.
       </para>
      </listitem>

      <listitem>
       <para>
        Have initdb issue a warning about placing the data directory at the
        top of a file system mount point (Bruce Momjian)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

   </sect3>

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

     <itemizedlist>

      <listitem>
       <para>
        Add an embedded list interface (Andres Freund)
       </para>
      </listitem>

      <listitem>
       <para>
        Add infrastructure to better support plug-in <link
        linkend="bgworker">background worker processes</link>
        (&Aacute;lvaro Herrera)
       </para>
      </listitem>

      <listitem>
       <para>
        Create a centralized timeout <acronym>API</> (Zolt&aacute;n
        B&ouml;sz&ouml;rm&eacute;nyi)
       </para>
      </listitem>

      <listitem>
       <para>
        Create libpgcommon and move <function>pg_malloc()</> and other
        functions there (&Aacute;lvaro Herrera, Andres Freund)
       </para>

       <para>
        This allows libpgport to be used solely for porting code.
       </para>
      </listitem>

      <listitem>
       <para>
        Standardize on naming of client-side memory allocation functions (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Add compiler designations to indicate some <function>ereport()</>
        and <function>elog()</> calls do not return (Peter Eisentraut,
        Andres Freund, Tom Lane, Heikki Linnakangas)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow options to be passed to the regression
        test output comparison utility via <link
        linkend="regress-evaluation"><envar>PG_REGRESS_DIFF_OPTS</></link>
        (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Add isolation tests for <link
        linkend="SQL-CREATEINDEX"><command>CREATE INDEX
        CONCURRENTLY</></link> (Abhijit Menon-Sen)
       </para>
      </listitem>

      <listitem>
       <para>
        Remove typedefs for <type>int2</>/<type>int4</> as they are better
        represented as <type>int16</>/<type>int32</> (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Fix <link linkend="install">install-strip</link> on Mac <productname>OS
        X</> (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Remove <link linkend="configure">configure</link> flag
        <option>--disable-shared</>, as it is no longer used (Bruce
        Momjian)
       </para>
      </listitem>

      <listitem>
       <para>
        Rewrite pgindent in <application>Perl</> (Andrew Dunstan)
       </para>
      </listitem>

      <listitem>
       <para>
        Add Emacs macro to match <productname>PostgreSQL</> perltidy
        formatting (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Run tool to check the keyword list when the backend grammar is
        changed (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Centralize <application>flex</> and <application>bison</>
        <application>make</> rules (Peter Eisentraut)
       </para>

       <para>
        This is useful for <application>pgxs</> authors.
       </para>
      </listitem>

      <listitem>
       <para>
        Support <function>Assert()</> in client-side code (Andrew Dunstan)
       </para>
      </listitem>

      <listitem>
       <para>
        Change many internal backend functions to return <type>OID</>s
        rather than void (Dimitri Fontaine)
       </para>

       <para>
        This is useful for event triggers.
       </para>
      </listitem>

      <listitem>
       <para>
        Invent pre-commit/pre-prepare/pre-subcommit events for transaction
        callbacks (Tom Lane)
       </para>

       <para>
        Loadable modules that use transaction callbacks might need modification
        to handle these new event types.
       </para>
      </listitem>

      <listitem>
       <para>
        Add function <link
        linkend="functions-info-catalog-table"><function>pg_identify_object()</></link>
        to dump an object in machine-readable format (&Aacute;lvaro
        Herrera)
       </para>
      </listitem>

      <listitem>
       <para>
        Add post-<command>ALTER</>-object server hooks (KaiGai Kohei)
       </para>
      </listitem>

      <listitem>
       <para>
        Implement a generic binary heap and use it for Merge-Append
        operations (Abhijit Menon-Sen)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve ability to detect official timezone abbreviation changes
        (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <application>pkg-config</> support <application>libpq</>
        and <application>ecpg</> libraries (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Remove <filename>src/tool/backend</>, now that the content is on
        the <productname>PostgreSQL</> wiki (Bruce Momjian)
       </para>
      </listitem>

      <listitem>
       <para>
        Split out <link linkend="wal"><acronym>WAL</></link> reading as
        an independent facility (Heikki Linnakangas, Andres Freund)
       </para>
      </listitem>

      <listitem>
       <para>
        Use a 64-bit integer to represent <link
        linkend="wal"><acronym>WAL</></link> positions
        (<structname>XLogRecPtr</>) instead of two 32-bit integers
        (Heikki Linnakangas)
       </para>

       <para>
        Generally, tools that need to read the <acronym>WAL</> format
        will need to be adjusted.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <link linkend="plpython">PL/Python</link> to support
        platform-specific include directories (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <link linkend="plpython">PL/Python</link> on <productname>OS
        X</> to build against custom versions of <application>Python</>
        (Peter Eisentraut)
       </para>
      </listitem>

     </itemizedlist>

   </sect3>

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

    <itemizedlist>

      <listitem>
       <para>
        Allow <link linkend="SQL-CREATEFOREIGNDATAWRAPPER">foreign data
        wrappers</link> to support writes (inserts/updates/deletes) on foreign
        tables (KaiGai Kohei)
       </para>
      </listitem>

      <listitem>
       <para>
        Add a <productname>Postgres</> <link linkend="postgres-fdw">foreign
        data wrapper</link> contrib module (Shigeru Hanada)
       </para>

       <para>
        This foreign data wrapper supports writes.
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="pgxlogdump"><application>pg_xlogdump</></link>
        contrib program (Andres Freund)
       </para>
      </listitem>

      <listitem>
       <para>
        Add support for indexing of regular-expression searches in
        <link linkend="pgtrgm"><productname>pg_trgm</></link>
        (Alexander Korotkov)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <link linkend="pgtrgm"><productname>pg_trgm</></link>
        handling of multibyte characters (Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="pgstattuple">pgstattuple function</link> to report the
        size of the <type>GIN</> pending index insertion list (Fujii Masao)
       </para>
      </listitem>

      <listitem>
       <para>
        Have <link linkend="oid2name"><application>oid2name</></link>,
        <link linkend="pgbench"><application>pgbench</></link>, and
        <link linkend="vacuumlo"><application>vacuumlo</></link> set
        <varname>fallback_application_name</> (Amit Kapila)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve output of <link
        linkend="pgtesttiming"><application>pg_test_timing</></link>
        (Bruce Momjian)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve output of <link
        linkend="pgtestfsync"><application>pg_test_fsync</></link>
        (Peter Geoghegan)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <link linkend="dblink">dblink</link> option validator
        (Tom Lane)
       </para>

       <para>
        Details?
       </para>
      </listitem>

    </itemizedlist>

    <sect4>
     <title><link linkend="pgupgrade"><application>pg_upgrade</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Allow <application>pg_upgrade</> <option>--jobs</> to do
        parallelism (Bruce Momjian)
       </para>

       <para>
        This allows parallel schema dump/restore of databases, as well as
        parallel copy/link of data files per tablespace.
       </para>
      </listitem>

      <listitem>
       <para>
        Have <application>pg_upgrade</> create Unix-domain sockets in
        the current directory (Bruce Momjian, Tom Lane)
       </para>

       <para>
        This reduces the possibility that someone will accidentally connect
        during the upgrade.
       </para>
      </listitem>

      <listitem>
       <para>
        Have <application>pg_upgrade</> <option>--check</> mode properly
        detect the location of non-default socket directories (Bruce
        Momjian, Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve performance of <application>pg_upgrade</> for databases
        with many tables (Bruce Momjian)
       </para>
      </listitem>

      <listitem>
       <para>
        Increase <application>pg_upgrade</> logging content by showing
        executed command (&Aacute;lvaro Herrera)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <application>pg_upgrade</>'s status display during
        copy/link (Bruce Momjian)
       </para>
      </listitem>

     </itemizedlist>

    </sect4>

    <sect4>
     <title><link linkend="pgbench"><application>pgbench</></link></title>

     <itemizedlist>

      <listitem>
       <para>
        Add <option>--foreign-keys</> option to <application>pgbench</>
        (Jeff Janes)
       </para>

       <para>
        This adds foreign key constraints to the standard tables created by
        <application>pgbench</>, for use in foreign key performance testing.
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <application>pgbench</> to aggregate performance statistics
        and produce output every <option>--aggregate-interval</>
        seconds (Tomas Vondra)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <application>pgbench</> <option>--sampling-rate</> option
        to control the percentage of transactions logged (Tomas Vondra)
       </para>
      </listitem>

      <listitem>
       <para>
        Reduce and improve the status message output of
        <application>pgbench</>'s initialization mode (Robert Haas,
        Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <application>pgbench</> <option>-q</> mode to print one output
        line every five seconds (Tomas Vondra)
       </para>
      </listitem>

      <listitem>
       <para>
        Output <application>pgbench</> elapsed and estimated remaining
        time during initialization (Tomas Vondra)
       </para>
      </listitem>

      <listitem>
       <para>
        Allow <application>pgbench</> to use a larger scale factor
        (Greg Smith)
       </para>
      </listitem>

    </itemizedlist>

    </sect4>

   </sect3>

   <sect3>
    <title>Documentation</title>

    <itemizedlist>

      <listitem>
       <para>
        Allow <productname>EPUB</>-format documentation to be created
        (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Update <productname>FreeBSD</> kernel configuration documentation
        (Brad Davis)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <link linkend="tutorial-window"><literal>WINDOW</>
        function</link> documentation (Bruce Momjian, Tom Lane)
       </para>
      </listitem>

      <listitem>
       <para>
        Add <link linkend="docguide">instructions</link> for setting
        up the documentation tool chain on Mac <productname>OS X</>
        (Peter Eisentraut)
       </para>
      </listitem>

      <listitem>
       <para>
        Improve <link
        linkend="guc-commit-delay"><varname>commit_delay</></link>
        documentation (Peter Geoghegan)
       </para>
      </listitem>

    </itemizedlist>

   </sect3>

  </sect2>
 </sect1>
