--- /dev/null
+<!-- doc/src/sgml/release-9.6.sgml -->
+<!-- See header comment in release.sgml about typical markup -->
+
+ <sect1 id="release-9-6">
+ <title>Release 9.6</title>
+
+ <note>
+ <title>Release Date</title>
+ <simpara>2016-??-??</simpara>
+ <simpara>Current as of 2016-05-02 (commit 21c2b1c61)</simpara>
+ </note>
+
+ <sect2>
+ <title>Overview</title>
+
+ <para>
+ Major enhancements in <productname>PostgreSQL</> 9.6 include:
+ </para>
+
+ <!-- This list duplicates items below, but without authors or details-->
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ To be filled in, but see below for the long version
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <para>
+ The above items are explained in more detail in the sections below.
+ </para>
+
+ </sect2>
+
+ <sect2>
+
+ <title>Migration to Version 9.6</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 9.6 contains a number of changes that may affect compatibility
+ with previous releases. Observe the following incompatibilities:
+ </para>
+
+ <itemizedlist>
+
+ <listitem>
+ <para>
+ To be filled in, but issues are called out in relevant sections below
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect2>
+
+ <sect2>
+ <title>Changes</title>
+
+ <para>
+ Below you will find a detailed account of the changes between
+ <productname>PostgreSQL</productname> 9.6 and the previous major
+ release.
+ </para>
+
+ <sect3>
+ <title>Server</title>
+
+ <sect4>
+ <title>Parallel Queries</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-09-18 [4a4e6893a] Glue layer to connect the executor to the shm_mq mechani
+2015-09-23 [a0d9f6e43] Add readfuncs.c support for plan nodes.
+2015-09-28 [d1b7c1ffe] Parallel executor support.
+2015-09-30 [3bd909b22] Add a Gather executor node.
+2015-10-16 [ee7ca559f] Add a C API for parallel heap scans.
+2015-10-16 [bfc78d719] Rewrite interaction of parallel mode with parallel execu
+2015-10-16 [a53c06a13] Prohibit parallel query when the isolation level is seri
+2015-11-02 [1efc7e538] Fix problems with ParamListInfo serialization mechanism.
+2015-11-06 [6e71dd7ce] Modify tqueue infrastructure to support transient record
+2015-11-11 [f0661c4e8] Make sequential scans parallel-aware.
+2015-11-11 [80558c1f5] Generate parallel sequential scan plans in simple cases.
+2015-12-09 [b287df70e] Allow EXPLAIN (ANALYZE, VERBOSE) to display per-worker s
+2016-01-20 [45be99f8c] Support parallel joins, and make related improvements.
+2016-02-03 [69d34408e] Allow parallel custom and foreign scans.
+2016-02-07 [a1c1af2a1] Introduce group locking to prevent parallel processes fr
+2016-02-07 [7c944bd90] Introduce a new GUC force_parallel_mode for testing purp
+2016-02-25 [57a6a72b6] Enable parallelism for prepared statements and extended
+2016-02-26 [7bea19d0a] On second thought, disable parallelism for prepared stat
+2016-03-21 [e06a38965] Support parallel aggregation.
+2016-04-05 [11c8669c0] Add parallel query support functions for assorted aggreg
+2016-04-08 [25fe8b5f1] Add a 'parallel_degree' reloption.
+2016-04-27 [59eb55127] Fix EXPLAIN VERBOSE output for parallel aggregate.
+-->
+ <para>
+ Parallel queries (Robert Haas, Amit Kapila, many others)
+ </para>
+
+ <para>
+ With 9.6, <productname>PostgreSQL</> introduces initial support
+ for parallel execution of large queries. Scans over large tables can
+ be parallelized, as can hash joins and computation of aggregate
+ functions. Much remains to be done, but this is already a useful set
+ of features.
+ </para>
+
+ <para>
+ Use of parallel query execution can be controlled through the new
+ configuration parameters
+ <xref linkend="guc-max-parallel-degree">,
+ <xref linkend="guc-force-parallel-mode">,
+ <xref linkend="guc-parallel-setup-cost">, and
+ <xref linkend="guc-parallel-tuple-cost">.
+ </para>
+
+ <para>
+ This section needs to get fleshed out, but by how much?
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-16 [7aea8e4f2] Determine whether it's safe to attempt a parallel plan f
+-->
+ <para>
+ Provide infrastructure for marking functions as parallel-safe or not
+ (Robert Haas, Amit Kapila)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title>Indexes</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-09-02 [30bb26b5e] Allow usage of huge maintenance_work_mem for GIN build.
+-->
+ <para>
+ Allow GIN index builds to make effective use
+ of <varname>maintenance_work_mem</> settings larger than 1GB
+ (Robert Abraham, Teodor Sigaev)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-07 [e95680832] Add pages deleted from pending list to FSM
+2015-09-23 [dc943ad95] Allow autoanalyze to add pages deleted from pending list
+-->
+ <para>
+ Add pages deleted from a GIN index's pending list to the free space
+ map immediately, to reduce bloat if the table isn't vacuumed often
+ (Jeff Janes, Teodor Sigaev)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-28 [7f46eaf03] Add gin_clean_pending_list function to clean up GIN pend
+-->
+ <para>
+ Add <function>gin_clean_pending_list()</> function to allow manual
+ invocation of pending-list cleanup for a GIN index, separately from
+ vacuuming or analyzing the parent table (Jeff Janes)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-09 [013ebc0a7] Microvacuum for GIST
+2015-09-17 [22f519c92] Fix bug introduced by microvacuum for GiST
+-->
+ <para>
+ Improve handling of dead index tuples in GiST indexes
+ (Anastasia Lubennikova)
+ </para>
+
+ <para>
+ Dead index tuples are now marked as such when an index scan notices
+ that the corresponding heap tuple is dead; and when inserting tuples,
+ marked-dead tuples will be removed if needed to make space on the page.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-30 [acdf2a8b3] Introduce SP-GiST operator class over box.
+-->
+ <para>
+ Add an SP-GiST operator class for type <type>box</>
+ (Alexander Lebedev)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title>General Performance</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-03-01 [a892234f8] Change the format of the VM fork to add a second bit per
+2016-03-08 [77a1d1e79] Department of second thoughts: remove PD_ALL_FROZEN.
+2016-03-10 [fd31cd265] Don't vacuum all-frozen pages.
+2016-03-11 [7087166a8] pg_upgrade: Convert old visibility map format to new for
+-->
+ <para>
+ Avoid re-vacuuming pages containing only frozen tuples
+ (Masahiko Sawada, Robert Haas)
+ </para>
+
+ <para>
+ Formerly, an anti-wraparound vacuum had to visit every page of a
+ table whether or not there was anything to do there. Now, pages
+ containing only already-frozen tuples are identified in the table's
+ visibility map, and can be skipped by vacuum even when it's doing
+ transaction wraparound prevention. This should greatly reduce the
+ cost of maintaining large tables containing mostly-unchanging data.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-30 [e84290823] Avoid useless truncation attempts during VACUUM.
+-->
+ <para>
+ Avoid useless heap-truncation attempts during <command>VACUUM</>
+ (Jeff Janes, Tom Lane)
+ </para>
+
+ <para>
+ This change avoids taking an exclusive table lock in some cases where
+ no truncation is really possible. The main benefit comes from
+ avoiding unnecessary query cancellations on standby servers.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-09 [687f2cd7a] Avoid pin scan for replay of XLOG_BTREE_VACUUM
+2016-04-03 [3e4b7d879] Avoid pin scan for replay of XLOG_BTREE_VACUUM in all ca
+-->
+ <para>
+ Reduce interlocking on standby servers during replay of btree index
+ vacuuming operations (Simon Riggs)
+ </para>
+
+ <para>
+ This change avoids substantial replication delays that sometimes
+ occurred while replaying such operations.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-11 [d4c3a156c] Remove GROUP BY columns that are functionally dependent
+-->
+ <para>
+ Drop entries from <literal>GROUP BY</> if they are functionally
+ dependent on other entries (David Rowley)
+ </para>
+
+ <para>
+ If a <literal>GROUP BY</> clause includes all columns of a
+ non-deferred primary key, as well as other columns of the same
+ relation, those other columns are redundant and can be dropped from
+ the grouping. This saves computation in many common cases.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-11 [9118d03a8] When appropriate, postpone SELECT output expressions til
+2016-03-25 [d543170f2] Don't split up SRFs when choosing to postpone SELECT out
+-->
+ <para>
+ When appropriate, postpone evaluation of <command>SELECT</> output
+ expressions till after <literal>ORDER BY</> sorting
+ (Konstantin Knizhnik)
+ </para>
+
+ <para>
+ This change ensures that volatile or expensive functions in the
+ output list are executed in the order suggested by <literal>ORDER
+ BY</>, and that they are not evaluated more times than required when
+ there's a <literal>LIMIT</>. Previously, these properties held if
+ the ordering was performed by an indexscan or pre-mergejoin sort,
+ but not if it was performed by a top-level sort step.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-10 [428b1d6b2] Allow to trigger kernel writeback after a configurable n
+2016-04-13 [fa11a09fe] Fix assorted portability issues with using msync() for d
+2016-04-24 [8f91d87d4] Fix documentation & config inconsistencies around 428b1d
+2016-04-26 [72a98a639] Don't open formally non-existent segments in _mdfd_getse
+-->
+ <para>
+ Where feasible, trigger kernel writeback after a configurable number
+ of writes, to prevent accumulation of dirty data in kernel disk
+ buffers (Fabien Coelho, Andres Freund)
+ </para>
+
+ <para>
+ <productname>PostgreSQL</> writes data to the kernel's disk cache,
+ from where it should be flushed to physical storage in due time.
+ Many operating systems are not very smart about managing this, and
+ will allow large amounts of dirty data to accumulate then decide to
+ flush it all at once, leading to long delays for new I/O requests.
+ This change attempts to alleviate this problem by explicitly
+ requesting data flushes after a configurable interval.
+ </para>
+
+ <para>
+ On Linux, <function>sync_file_range()</> is used for this purpose,
+ and the feature is on by default because that function has few
+ downsides. The feature is also available on other platforms that
+ have <function>msync()</> or <function>posix_fadvise()</>, but those
+ interfaces have some undesirable side-effects so the feature is not
+ enabled by default on other platforms.
+ </para>
+
+ <para>
+ The new configuration parameters
+ <xref linkend="guc-backend-flush-after">,
+ <xref linkend="guc-bgwriter-flush-after">,
+ <xref linkend="guc-checkpoint-flush-after">, and
+ <xref linkend="guc-wal-writer-flush-after"> control this behavior.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-10 [9cd00c457] Checkpoint sorting and balancing.
+-->
+ <para>
+ Perform checkpoint writes in sorted order
+ (Fabien Coelho, Andres Freund)
+ </para>
+
+ <para>
+ Previously, checkpoints wrote out dirty pages in whatever order they
+ happen to appear in within shared buffers, which usually is nearly
+ random. That performs poorly, especially on rotating media. This
+ change causes checkpoint-driven writes to be done in order by file
+ and block number, and to be balanced across tablespaces.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [848ef42bb] Add the "snapshot too old" feature
+-->
+ <para>
+ Allow old MVCC snapshots to be invalidated after a configurable
+ timeout (Kevin Grittner)
+ </para>
+
+ <para>
+ Normally, deleted tuples cannot be physically removed by vacuuming
+ until the last transaction that could <quote>see</> them is gone.
+ A transaction that stays open for a long time can thus cause
+ considerable table bloat because space cannot be recycled. This
+ feature allows setting a time-based limit, via the new configuration
+ parameter <xref linkend="guc-old-snapshot-threshold">, on how long an
+ MVCC snapshot is guaranteed valid. After that, dead tuples are
+ candidates for removal. A transaction using an outdated snapshot
+ will get an error, but only if it attempts to read a page that's been
+ modified recently enough that it might have contained such data.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-31 [f9aefcb91] Support using index-only scans with partial indexes in m
+-->
+ <para>
+ Allow using an index-only scan with a partial index when the index's
+ predicate involves column(s) not stored in the index
+ (Tomas Vondra, Kyotaro Horiguchi)
+ </para>
+
+ <para>
+ An index-only scan is now allowed if the query mentions such columns
+ only in <literal>WHERE</> clauses that match the index predicate (and
+ hence need not be rechecked at runtime).
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [137805f89] Use Foreign Key relationships to infer multi-column join
+-->
+ <para>
+ Use foreign key relationships to infer selectivity for multi-column
+ join predicates (Tomas Vondra, David Rowley)
+ </para>
+
+ <para>
+ If a table <literal>t</> has a multi-column foreign key restriction,
+ say <literal>(a,b) REFERENCES r (x,y)</>, then a <literal>WHERE</>
+ condition such as <literal>t.a = r.x AND t.b = r.y</> cannot select
+ more than one <literal>r</> row per <literal>t</> row. The planner
+ formerly considered the AND'ed conditions to be independent and would
+ often drastically misestimate the selectivity as a result. Now it
+ compares the <literal>WHERE</> conditions to applicable foreign key
+ constraints and arrives at a better estimate.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-04 [804163bc2] Share transition state between different aggregates when
+-->
+ <para>
+ Improve aggregate-function performance by sharing calculations across
+ multiple aggregates if they have the same arguments and transition
+ functions (David Rowley)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-26 [8a7d07018] Speed up HeapTupleSatisfiesMVCC() by replacing the XID-i
+-->
+ <para>
+ Speed up visibility tests for recently-created tuples by checking
+ our transaction snapshot, not <structname>pg_clog</>, to decide if the
+ source transaction should be considered committed (Jeff Janes, Tom
+ Lane)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-15 [db76b1efb] Allow SetHintBits() to succeed if the buffer's LSN is ne
+-->
+ <para>
+ Allow tuple hint bits to be set sooner than before (Andres Freund)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-20 [978b2f65a] Speedup 2PC by skipping two phase state files in normal
+2016-03-10 [e0694cf9c] Reduce size of two phase file header
+-->
+ <para>
+ Improve performance of short-lived prepared transactions
+ (Stas Kelvich, Simon Riggs, Pavan Deolasee)
+ </para>
+
+ <para>
+ Two-phase commit information is now written only to WAL
+ during <command>PREPARE TRANSACTION</>, and read back from there
+ during <command>COMMIT PREPARED</>. A separate state file is created
+ only if the pending transaction does not get committed or aborted by
+ the time of the next checkpoint.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-08 [25c539233] Improve performance in freeing memory contexts
+-->
+ <para>
+ Improve performance of memory context destruction (Jan Wieck)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-26 [cc988fbb0] Improve ResourceOwners' behavior for large numbers of ow
+-->
+ <para>
+ Improve performance of ResourceOwners with many tracked objects
+ (Aleksander Alekseev)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-06 [aa2387e2f] Improve speed of timestamp/time/date output functions.
+-->
+ <para>
+ Improve speed of the output functions for timestamps, times, and dates
+ (David Rowley, Andres Freund)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-10 [37c54863c] Rework wait for AccessExclusiveLocks on Hot Standby
+-->
+ <para>
+ Avoid some spurious waits for AccessExclusiveLocks in hot-standby
+ queries (Jeff Janes)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-01 [be4b4dc75] Omit null rows when applying the Haas-Stokes estimator f
+2016-04-01 [3d3bf62f3] Omit null rows when setting the threshold for what's a m
+2016-04-04 [391159e03] Partially revert commit 3d3bf62f30200500637b24fdb7b992a9
+-->
+ <para>
+ Improve <command>ANALYZE</>'s estimates for columns with many nulls
+ (Tomas Vondra, Alex Shulgin)
+ </para>
+
+ <para>
+ Previously the code tended to underestimate the number of non-null
+ distinct values in a column with many nulls, and it also might make
+ poor decisions about what is a most-common value.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-04 [84f9a35e3] Improve estimate of distinct values in estimate_num_grou
+-->
+ <para>
+ Improve planner's estimate of the number of distinct values in a
+ query result (Tomas Vondra)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-16 [7975c5e0a] Allow the WAL writer to flush WAL at a reduced rate.
+-->
+ <para>
+ Reduce the WAL writer's flush rate to reduce storage bottlenecks
+ (Andres Freund)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [719c84c1b] Extend relations multiple blocks at a time to improve sc
+-->
+ <para>
+ Extend relations multiple blocks at a time (Dilip Kumar)
+ </para>
+
+ <para>
+ This reduces kernel traffic, and improves scalability when multiple
+ processes are inserting into the same relation.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [071180377] Use quicksort, not replacement selection, for external s
+-->
+ <para>
+ Improve sorting performance by using quicksort, not replacement
+ selection, within steps of an external sort (Peter Geoghegan)
+ </para>
+
+ <para>
+ This behavior can be adjusted via the new configuration
+ parameter <xref linkend="guc-replacement-sort-tuples">.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-17 [0011c0091] Improve memory management for external sorts.
+-->
+ <para>
+ Improve memory management for external sorts (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-09 [0e57b4d8b] Speed up text sorts where the same strings occur multipl
+2015-10-20 [5be94a9eb] Be a bit more rigorous about how we cache strcoll and st
+-->
+ <para>
+ Speed up text sorts where the same strings occur multiple times
+ (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-06 [a76ef15d9] Add sort support routine for the UUID data type.
+-->
+ <para>
+ Speed up sorting of <type>uuid</>-type columns (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-16 [b648b7034] Speed up CREATE INDEX CONCURRENTLY's TID sort.
+-->
+ <para>
+ Speed up <command>CREATE INDEX CONCURRENTLY</> by treating TIDs
+ as 64-bit integers during the sort phase (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-17 [f1f5ec1ef] Reuse abbreviated keys in ordered [set] aggregates.
+-->
+ <para>
+ Improve performance of ordered-set aggregates by reusing
+ abbreviated-key information (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [5364b357f] Increase maximum number of clog buffers.
+-->
+ <para>
+ Increase the number of clog buffers for better scalability
+ (Amit Kapila, Andres Freund)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-06 [0e141c0fb] Reduce ProcArrayLock contention by removing backends in
+2015-09-03 [4aec49899] Assorted code review for recent ProcArrayLock patch.
+-->
+ <para>
+ Reduce contention for the ProcArrayLock (Amit Kapila, Robert Haas)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-15 [6150a1b08] Move buffer I/O and content LWLocks out of the main tran
+-->
+ <para>
+ Improve performance by moving buffer content locks into the buffer
+ descriptors (Andres Freund, Simon Riggs)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-10 [48354581a] Allow Pin/UnpinBuffer to operate in a lockfree manner.
+-->
+ <para>
+ Replace shared-buffer header spinlocks with atomic operations
+ to improve scalability (Alexander Korotkov, Andres Freund)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-10 [008608b9d] Avoid the use of a separate spinlock to protect a LWLock
+-->
+ <para>
+ Use atomic operations, rather than a spinlock, to protect an LWLock's
+ wait queue (Andres Freund)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-23 [44ca4022f] Partition the freelist for shared dynahash tables.
+-->
+ <para>
+ Partition the freelist for shared hash tables, to reduce contention
+ on many-CPU servers (Aleksander Alekseev)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-05 [6c82d8d1f] Further reduce overhead for passing plpgsql variables to
+-->
+ <para>
+ Speed up expression evaluation in <application>PL/pgSQL</> by keeping
+ ParamListInfo entries for simple variables valid at all times
+ (Tom Lane)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-06 [4f33621f3] Don't set SO_SNDBUF on recent Windows versions that have
+-->
+ <para>
+ Avoid reducing the <literal>SO_SNDBUF</> setting below its default on
+ recent Windows versions (Chen Huajun)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title>Monitoring</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-03-10 [53be0b1ad] Provide much better wait information in pg_stat_activity
+-->
+ <para>
+ Improve the <link
+ linkend="pg-stat-activity-view"><structname>pg_stat_activity</></link>
+ view's information about what a process is waiting for (Amit Kapila,
+ Ildus Kurbangaliev)
+ </para>
+
+ <para>
+ Historically a process has only been shown as waiting if it was
+ waiting for a heavyweight lock. Now waits for lightweight locks
+ and buffer pins are also shown in <structname>pg_stat_activity</>.
+ Also, the type of lock being waited for is now visible.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-15 [c16dc1aca] Add simple VACUUM progress reporting.
+-->
+ <para>
+ Add <link linkend="pg-stat-progress-vacuum-view"><structname>pg_stat_progress_vacuum</></link>
+ system view to provide progress reporting for <command>VACUUM</>
+ operations (Amit Langote, Robert Haas, Vinayak Pokale, Rahila Syed)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-17 [a5c43b886] Add new system view, pg_config
+-->
+ <para>
+ Add <link linkend="view-pg-config"><structname>pg_config</></link>
+ system view to expose the same information available from
+ the <application>pg_config</> utility (Joe Conway)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-10 [3f811c2d6] Add confirmed_flush column to pg_replication_slots.
+-->
+ <para>
+ Add a <structfield>confirmed_flush_lsn</> column to
+ the <link linkend="view-pg-replication-slots"><structname>pg_replication_slots</></link>
+ system view (Marko Tiikkaja)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-07 [b1a9bad9e] pgstat: add WAL receiver status view & SRF
+-->
+ <para>
+ Add <link linkend="pg-stat-wal-receiver-view"><structname>pg_stat_wal_receiver</></link>
+ system view to provide information about the state of a hot-standby
+ server's WAL receiver process (Michael Paquier)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-22 [52f5d578d] Create a function to reliably identify which sessions bl
+-->
+ <para>
+ Add <function>pg_blocking_pids()</> function to reliably identify
+ which sessions block which others (Tom Lane)
+ </para>
+
+ <para>
+ This function returns an array of the process IDs of any sessions that
+ are blocking the session with the given process ID. Historically
+ users have obtained such information using a self-join on
+ the <structname>pg_locks</> view; but it's unreasonably tedious to do
+ it that way with any modicum of correctness, and the addition of
+ parallel queries has made the approach entirely impractical, since
+ locks might be held or awaited by child worker processes rather than
+ the session's main process.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-05 [dc7d70ea0] Expose control file data via SQL accessible functions.
+-->
+ <para>
+ Add <function>pg_control_system()</>,
+ <function>pg_control_checkpoint()</>,
+ <function>pg_control_recovery()</>,
+ and <function>pg_control_init()</> functions to expose fields
+ of <filename>pg_control</> to SQL (Joe Conway, Michael Paquier)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-12 [e63bb4549] Add new user fn pg_current_xlog_flush_location()
+-->
+ <para>
+ Add function <function>pg_current_xlog_flush_location()</> to expose
+ the current transaction log flush location (Tomas Vondra)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-17 [a04bb65f7] Add new function pg_notification_queue_usage.
+-->
+ <para>
+ Add function <function>pg_notification_queue_usage()</> to report
+ how full the <command>NOTIFY</> queue is (Brendan Jurd)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-25 [7b5ef8f2d] Limit the verbosity of memory context statistics dumps.
+-->
+ <para>
+ Limit the verbosity of memory context statistics dumps (Tom Lane)
+ </para>
+
+ <para>
+ The memory usage dump printed to the postmaster log during an
+ out-of-memory failure now summarizes statistics when there are a large
+ number of memory contexts, rather than possibly printing a very large
+ report. There's also a <quote>grand total</> summary line now.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-12 [59a884e98] Change delimiter used for display of NextXID
+-->
+ <para>
+ Change display format for NextXID in <application>pg_controldata</>
+ and related places (Joe Conway, Bruce Momjian)
+ </para>
+
+ <para>
+ Display epoch-and-transaction-ID values in the
+ format <replaceable>number</><literal>:</><replaceable>number</>.
+ The previous
+ format <replaceable>number</><literal>/</><replaceable>number</> was
+ confusingly similar to that used for LSNs.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title><acronym>Authentication</></title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-04-08 [34c33a1f0] Add BSD authentication method.
+-->
+ <para>
+ Create a <literal>bsd</> authentication method to allow use of
+ the BSD Authentication service for <productname>PostgreSQL</>
+ client authentication (Marisa Emerson)
+ </para>
+
+ <para>
+ BSD Authentication is currently only available on OpenBSD.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [2f1d2b7a7] Set PAM_RHOST item for PAM authentication
+-->
+ <para>
+ When using PAM authentication, provide the client IP address or host
+ name to PAM modules via the <literal>PAM_RHOST</> item (Grzegorz
+ Sampolski)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-07 [5e0b5dcab] Provide more detail in postmaster log for password authe
+-->
+ <para>
+ Provide detail in the postmaster log for more password authentication
+ failures (Tom Lane)
+ </para>
+
+ <para>
+ All ordinarily-reachable password authentication failure cases should
+ now provide specific <literal>DETAIL</> fields in the log.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-06 [643beffe8] Support RADIUS passwords up to 128 characters
+-->
+ <para>
+ Support RADIUS passwords up to 128 characters long (Marko Tiikkaja)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [35e2e357c] Add authentication parameters compat_realm and upn_usena
+-->
+ <para>
+ Add new SSPI authentication parameters <varname>compat_realm</>
+ and <varname>upn_usename</>, to make it possible to make SSPI
+ work more like GSSAPI (Christian Ullrich)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title>Server Configuration</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-02-02 [7d17e683f] Add support for systemd service notifications
+-->
+ <para>
+ Add <option>--with-systemd</> configure switch to enable calling
+ <function>sd_notify()</> at server start and stop
+ (Peter Eisentraut)
+ </para>
+
+ <para>
+ This allows the use of <application>systemd</> service units of
+ type <literal>notify</>, which greatly simplifies management
+ of <productname>PostgreSQL</> under <application>systemd</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-08 [1aba62ec6] Allow per-tablespace effective_io_concurrency
+-->
+ <para>
+ Allow <varname>effective_io_concurrency</> to be set as a
+ tablespace parameter, to support cases where different tablespaces
+ have different I/O characteristics (Julien Rouhaud)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-16 [c6dda1f48] Add idle_in_transaction_session_timeout.
+-->
+ <para>
+ Allow sessions to be terminated automatically if they sit too long in
+ an idle-in-transaction state (Vik Fearing)
+ </para>
+
+ <para>
+ This behavior is enabled and controlled by the new configuration
+ parameter <xref linkend="guc-idle-in-transaction-session-timeout">.
+ It can be useful to prevent forgotten transactions from holding onto
+ locks or preventing vacuum cleanup for very long periods.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-07 [f828654e1] Add log_line_prefix option 'n' for Unix epoch.
+2015-09-07 [b1e1862a1] Coordinate log_line_prefix options 'm' and 'n' to share
+-->
+ <para>
+ Add <varname>log_line_prefix</> option <literal>%n</> to print the
+ time as a Unix epoch, with milliseconds (Tomas Vondra, Jeff Davis)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-16 [f4c454e9b] Add syslog_sequence_numbers parameter
+2016-03-16 [fc201dfd9] Add syslog_split_messages parameter
+-->
+ <para>
+ Add <xref linkend="guc-syslog-sequence-numbers">
+ and <xref linkend="guc-syslog-split-messages">
+ configuration parameters to provide more control over message format
+ when logging to <systemitem>syslog</> (Peter Eisentraut)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-18 [b555ed810] Merge wal_level "archive" and "hot_standby" into new nam
+-->
+ <para>
+ Merge the <literal>archive</> and <literal>hot_standby</> values of
+ the <xref linkend="guc-wal-level"> configuration parameter into a
+ single value <literal>replica</> (Peter Eisentraut)
+ </para>
+
+ <para>
+ Making a distinction between these settings no longer appears to be a
+ good idea, and it's in the way of planned future simplification of
+ replication setup. The old names are still accepted but are
+ converted internally.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-19 [9a83564c5] Allow SSL server key file to have group read access if o
+-->
+ <para>
+ Allow the server's SSL key file to have group read access if owned by
+ root (Christoph Berg)
+ </para>
+
+ <para>
+ Formerly we insisted on the key file being owned by the user running
+ the <productname>PostgreSQL</> server, but that is inconvenient for
+ some systems (such as Debian) that wish to manage certificates
+ centrally. So also allow the case where the key file is owned by
+ root and has group read access. It's up to the root admin to ensure
+ that such a group doesn't include any untrusted users.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title>Reliability</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-11-12 [ac1d7945f] Make idle backends exit if the postmaster dies.
+-->
+ <para>
+ Force backends to exit if the postmaster dies
+ (Rajeev Rastogi and Robert Haas)
+ </para>
+
+ <para>
+ Under normal circumstances the postmaster should always outlive its
+ child processes. If for some reason it dies, cause backend sessions
+ to exit with an error. Formerly, existing backends would continue to
+ run until their client disconnects; but that is unsafe and
+ inefficient, and furthermore it prevents a new postmaster from being
+ started until the last old backend is gone. Backends will detect
+ postmaster death when waiting for client I/O, so the exit will not be
+ instantaneous, but in most circumstances it should happen no later
+ than the end of the current query.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-07 [fcff8a575] Detect SSI conflicts before reporting constraint violati
+-->
+ <para>
+ Check for serializability conflicts before reporting
+ constraint-violation failures (Thomas Munro)
+ </para>
+
+ <para>
+ When using serializable transaction isolation, it is desirable that
+ any error due to a concurrent transaction should manifest as a
+ serialization failure, thereby cueing the application that a retry
+ might succeed. Unfortunately, this doesn't reliably happen for
+ duplicate-key failures caused by concurrent insertions. This change
+ ensures that such an error will be reported as a serialization error,
+ if the application explicitly checked for the presence of a
+ conflicting key (and didn't find it) earlier in the transaction.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+XXX this is pending backpatch, may need to remove
+2016-04-26 [c6ff84b06] Emit invalidations to standby for transactions without x
+-->
+ <para>
+ Ensure that invalidation messages are recorded in WAL even when
+ issued by a transaction that has no XID assigned (Andres Freund)
+ </para>
+
+ <para>
+ This fixes some corner cases in which transactions on standby
+ servers failed to notice changes such as new indexes.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+XXX this is pending backpatch, may need to remove
+2016-04-28 [e2c79e14d] Prevent multiple cleanup process for pending list in GIN
+-->
+ <para>
+ Prevent multiple processes from trying to clean a GIN index's pending
+ list concurrently (Teodor Sigaev, Jeff Janes)
+ </para>
+
+ <para>
+ This had been intentionally allowed, but it causes race conditions
+ that can result in vacuum missing index entries it needs to delete.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+XXX this is pending backpatch, may need to remove
+2016-04-08 [7c7d4fdda] Distrust external OpenSSL clients; clear err queue
+-->
+ <para>
+ Clear the OpenSSL error queue before OpenSSL calls, rather than
+ assuming it's clear already; and make sure we leave it clear
+ (Peter Geoghegan, Dave Vitek, Peter Eisentraut)
+ </para>
+
+ <para>
+ This avoids problems when there are multiple connections using
+ OpenSSL within a single process and not all the code involved
+ follows the same rules for when to clear the error queue.
+ While the problem is worse for <application>libpq</>, it's
+ possible for it to arise within the server as well.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ </sect3>
+
+ <sect3>
+ <title>Replication and Recovery</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-08-11 [6fcd88511] Allow pg_create_physical_replication_slot() to reserve W
+2015-09-06 [c314ead5b] Add ability to reserve WAL upon slot creation via replic
+-->
+ <para>
+ Add a feature to the replication protocol, and a corresponding option
+ to the <function>pg_create_physical_replication_slot()</> function,
+ to allow reserving WAL immediately when creating a replication slot
+ (Gurjeet Singh, Michael Paquier)
+ </para>
+
+ <para>
+ This allows creation of a replication slot to guarantee that all the
+ WAL for a base backup will be available afterwards.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-28 [0dc848b03] pg_basebackup: Add -slot option
+-->
+ <para>
+ Add a <option>--slot</option> option to <application>pg_basebackup</>
+ (Peter Eisentraut)
+ </para>
+
+ <para>
+ This lets <application>pg_basebackup</> use a replication slot defined
+ for WAL streaming. After the base backup completes, selecting the
+ same slot for regular streaming replication allows seamless startup of
+ the new standby server.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-05 [711768546] Implement backup API functions for non-exclusive backups
+-->
+ <para>
+ Extend <function>pg_start_backup()</> and <function>pg_stop_backup()</>
+ to support non-exclusive backups (Magnus Hagander)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-06 [989be0810] Support multiple synchronous standby servers.
+2016-04-27 [4c804fbdf] Clean up parsing of synchronous_standby_names GUC variab
+2016-04-30 [17d5db352] Remove warning about num_sync being too large in synchro
+-->
+ <para>
+ Support synchronous replication with multiple synchronous standby
+ servers, not just one (Sawada Masahiko, Beena Emerson, Michael
+ Paquier, Fujii Masao, Kyotaro Horiguchi)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-29 [314cbfc5d] Add new replication mode synchronous_commit = 'remote_ap
+-->
+ <para>
+ Add new setting <literal>remote_apply</> for configuration parameter
+ <xref linkend="guc-synchronous-commit"> (Thomas Munro)
+ </para>
+
+ <para>
+ In this mode, the master waits for the transaction to be applied on
+ the standby server, not just written to disk. That means that you
+ can count on a transaction started on the standby to see all commits
+ previously acknowledged by the master.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Queries</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-03-12 [23a27b039] Widen query numbers-of-tuples-processed counters to uint
+2016-03-14 [74a379b98] Use repalloc_huge() to enlarge a SPITupleTable's tuple p
+-->
+ <para>
+ Widen tuples-processed counters to 64 bits (Andreas Scherbaum)
+ </para>
+
+ <para>
+ This change allows command tags for <command>SELECT</> etc. to
+ correctly report tuple counts larger than 4 billion. So will
+ PL/pgSQL's <command>GET DIAGNOSTICS ... ROW_COUNT</> command.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-28 [8d32717b6] Avoid doing encoding conversions by double-conversion vi
+-->
+ <para>
+ Avoid doing encoding conversions by double-conversion
+ through <literal>MULE_INTERNAL</> encoding (Tom Lane)
+ </para>
+
+ <para>
+ Previously, many conversions for Cyrillic and Central European
+ single-byte encodings were done by converting to a
+ related <literal>MULE_INTERNAL</> coding scheme and then to the
+ destination encoding. Aside from being inefficient, this meant that
+ when the conversion encountered an untranslatable character, the error
+ message would confusingly complain about failure to convert to or
+ from <literal>MULE_INTERNAL</>, rather than the user-visible
+ encodings.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-28 [fbe5a3fb7] Only try to push down foreign joins if the user mapping
+-->
+ <para>
+ Push down joins of foreign tables to the foreign data wrapper only
+ when the user mappings match (Shigeru Hanada, Ashutosh Bapat)
+ </para>
+
+ <para>
+ Previously, the foreign join pushdown infrastructure left the question
+ of security entirely up to individual foreign data wrappers, but it
+ would be easy for an FDW to inadvertently open up subtle security
+ holes that way. So, make it the core code's job to determine which
+ user mapping OID is relevant, and don't attempt join pushdown unless
+ it's the same for all relevant relations.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Utility Commands</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-11-27 [92e38182d] COPY (INSERT/UPDATE/DELETE .. RETURNING ..)
+-->
+ <para>
+ Allow <command>COPY</> to copy the output of
+ an <literal>INSERT</>/<literal>UPDATE</>/<literal>DELETE</>
+ ... <literal>RETURNING</> query (Marko Tiikkaja)
+ </para>
+
+ <para>
+ Previously, an intermediate CTE had to be written to get this result.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-05 [f2fcad27d] Support ALTER THING .. DEPENDS ON EXTENSION
+-->
+ <para>
+ Introduce <command>ALTER <replaceable>object</> DEPENDS ON
+ EXTENSION</command> (Abhijit Menon-Sen)
+ </para>
+
+ <para>
+ This command allows a database object to be marked as depending on an
+ extension, so that it will automatically go away if the extension is
+ dropped (without needing <literal>CASCADE</>). But the object is not
+ part of the extension, and thus for example will be dumped separately
+ by <application>pg_dump</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-19 [bc4996e61] Make ALTER .. SET SCHEMA do nothing, instead of throwing
+-->
+ <para>
+ Make <command>ALTER <replaceable>object</> SET SCHEMA</> do nothing
+ when the object is already in the requested schema, rather than
+ throwing an error as it historically has for most object types (Marti
+ Raudsepp)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-14 [321eed5f0] Add ALTER OPERATOR command, for changing selectivity est
+2015-12-31 [0dab5ef39] Fix ALTER OPERATOR to update dependencies properly.
+-->
+ <para>
+ Add options to <command>ALTER OPERATOR</command> to change the
+ selectivity functions associated with an existing operator
+ (Uriy Zhuravlev)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-29 [2cd40adb8] Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMN
+-->
+ <para>
+ Add an <option>IF NOT EXISTS</> option to <command>ALTER TABLE ADD
+ COLUMN</> (Fabrízio de Royes Mello)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-14 [47167b790] Reduce lock levels for ALTER TABLE SET autovacuum storag
+2016-03-10 [fcb4bfddb] Reduce lock level for altering fillfactor
+-->
+ <para>
+ Reduce the lock strength needed by <command>ALTER TABLE</> when
+ setting fillfactor and autovacuum-related relation options
+ (Fabrízio de Royes Mello, Simon Riggs)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-23 [473b93287] Support CREATE ACCESS METHOD
+-->
+ <para>
+ Introduce <command>CREATE ACCESS METHOD</> to allow extensions to
+ create index access methods (Alexander Korotkov, Petr Jelínek)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-03 [b67aaf21e] Add CASCADE support for CREATE EXTENSION.
+-->
+ <para>
+ Add a <literal>CASCADE</> option to <command>CREATE
+ EXTENSION</command>, to automatically create extensions it depends on
+ (Petr Jelínek)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-22 [d371bebd3] Remove redundant CREATEUSER/NOCREATEUSER options in CREA
+-->
+ <para>
+ Remove the
+ long-deprecated <literal>CREATEUSER</>/<literal>NOCREATEUSER</>
+ options from <command>CREATE ROLE</> and allied commands (Tom Lane)
+ </para>
+
+ <para>
+ <literal>CREATEUSER</> actually meant <literal>SUPERUSER</>, for
+ ancient backwards-compatibility reasons. That's been a constant
+ source of confusion for people who (reasonably) expect it to
+ mean <literal>CREATEROLE</>. It's been deprecated for ten years
+ now, so fix the problem by removing it.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-05 [b943f502b] Have CREATE TABLE LIKE add OID column if any LIKEd table
+-->
+ <para>
+ Make <command>CREATE TABLE ... LIKE</> include an OID column if any
+ source table has one (Bruce Momjian)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-16 [f27a6b15e] Mark CHECK constraints declared NOT VALID valid if creat
+-->
+ <para>
+ If a <literal>CHECK</> constraint is declared <literal>NOT VALID</> in
+ a table creation command, automatically mark it valid (Amit Langote,
+ Amul Sul)
+ </para>
+
+ <para>
+ This matches the longstanding behavior of <literal>FOREIGN KEY</>
+ constraints.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-25 [c94959d41] Fix DROP OPERATOR to reset oprcom/oprnegate links to the
+-->
+ <para>
+ Fix <command>DROP OPERATOR</> to
+ clear <structname>pg_operator</>.<structfield>oprcom</>
+ and <structname>pg_operator</>.<structfield>oprnegate</> links to the
+ dropped operator (Roma Sokolov)
+ </para>
+
+ <para>
+ Formerly such links were left as-is, which could pose a problem in
+ the somewhat unlikely event that the dropped operator's OID was
+ reused for another operator.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-16 [c34df8a00] Disallow creation of indexes on system columns (except f
+-->
+ <para>
+ Disallow creation of indexes on system columns, except for OID
+ (David Rowley)
+ </para>
+
+ <para>
+ Such indexes were never considered supported, and would very possibly
+ misbehave since the system might change the system-column fields of a
+ tuple without updating indexes. But there was no error check to
+ prevent them from being created.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Permissions Management</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-04-06 [1574783b4] Use GRANT system to manage access to sensitive functions
+-->
+ <para>
+ Use the privilege system to manage access to sensitive functions
+ (Stephen Frost)
+ </para>
+
+ <para>
+ Formerly, many security-sensitive functions contained hard-wired
+ checks that would throw an error if they were called by a
+ non-superuser role. This forced use of superuser roles for some
+ relatively pedestrian tasks. The hard-wired error checks are now gone
+ in favor of making <application>initdb</> revoke the default
+ public <literal>EXECUTE</> privilege on these functions. This allows
+ installations to choose to grant usage of such functions to trusted
+ roles that need not have full superuser privilege.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [293007898] Reserve the "pg_" namespace for roles
+-->
+ <para>
+ Treat role names beginning with <literal>pg_</> as reserved
+ (Stephen Frost)
+ </para>
+
+ <para>
+ User creation of such role names is now disallowed. This prevents
+ conflicts with built-in roles created by <application>initdb</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [7a542700d] Create default roles
+-->
+ <para>
+ Create some <link linkend="default-roles">built-in roles</link> that
+ can be used to grant access to what were previously superuser-only
+ functions (Stephen Frost)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Data Types</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-12-22 [6efbded6e] Allow omitting one or both boundaries in an array slice
+-->
+ <para>
+ Allow omitting one or both boundaries in an array slice specifier,
+ for example <literal>array_col[3:]</>
+ (YUriy Zhuravlev)
+ </para>
+
+ <para>
+ Omitted boundaries are taken as the upper or lower limit of the
+ corresponding array subscript. This allows simpler specification of
+ many common use-cases.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-16 [a70e13a39] Be more careful about out-of-range dates and timestamps.
+-->
+ <para>
+ Be more careful about out-of-range dates and timestamps
+ (Vitaly Burovoy)
+ </para>
+
+ <para>
+ This change prevents unexpected out-of-range errors
+ for <type>timestamp with time zone</> values very close to the
+ implementation limits. Previously, the <quote>same</> value might be
+ accepted or not depending on the <varname>timezone</> setting,
+ meaning that a dump and reload could fail on a value that had been
+ accepted when presented. Now the limits are enforced according to
+ the equivalent UTC time, not local time, so as to be independent
+ of <varname>timezone</>.
+ </para>
+
+ <para>
+ Also, <productname>PostgreSQL</> is now more careful to detect
+ overflow in operations that compute new date or timestamp values,
+ such as <type>date</> <literal>+</> <type>integer</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-30 [50861cd68] Improve portability of I/O behavior for the geometric ty
+-->
+ <para>
+ In the geometric data types, make sure that infinity and NaN
+ component values are treated consistently during input and output
+ (Tom Lane)
+ </para>
+
+ <para>
+ Such values will now always print the same way as they would in a
+ simple <type>float8</> column, and be accepted the same way on input
+ as well. Previously the behavior was somewhat platform-dependent.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-07 [bb140506d] Phrase full text search.
+-->
+ <para>
+ Improve full text search to support searching for phrases, that is,
+ lexemes appearing adjacent to each other in a specific order, or with
+ at most a specified distance between them
+ (Teodor Sigaev, Oleg Bartunov, Dmitry Ivanov)
+ </para>
+
+ <para>
+ A phrase-search query can be specified in <type>tsquery</> input
+ using the new operators <literal><-></> and
+ <literal><<replaceable>N</>></literal>. The former means that
+ the lexemes before and after it must appear adjacent to each other in
+ that order. The latter means they can be separated by up
+ to <replaceable>N</> other lexemes.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-29 [61d66c44f] Fix support of digits in email/hostnames.
+-->
+ <para>
+ Fix text search parser to allow leading digits in <literal>email</>
+ and <literal>host</> tokens (Artur Zakirov)
+ </para>
+
+ <para>
+ In most cases this will result in few changes in the parsing of text.
+ But if you have data where such addresses occur frequently, it may be
+ worth rebuilding dependent <type>tsvector</> columns and indexes, so
+ that addresses of this form will be found properly by text searches.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-04 [d78a7d9c7] Improve support of Hunspell in ispell dictionary.
+2016-03-11 [8829af47e] Fix merge affixes for numeric ones
+2016-03-17 [f4ceed6ce] Improve support of Hunspell
+-->
+ <para>
+ Upgrade the <literal>ispell</> dictionary to handle modern Hunspell
+ files and support more languages (Artur Zakirov)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-30 [12c9a0400] Implement lookbehind constraints in our regular-expressi
+-->
+ <para>
+ Implement lookbehind constraints in regular expressions
+ (Tom Lane)
+ </para>
+
+ <para>
+ A lookbehind constraint is like a lookahead constraint in that it
+ consumes no text; but it checks for existence (or nonexistence) of a
+ match ending at the current point in the string, rather than one
+ starting at the current point. Similar features exist in many other
+ regular-expression engines.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-16 [b44d92b67] Sync regex code with Tcl 8.6.4.
+-->
+ <para>
+ In regular expressions, if an apparent three-digit octal
+ escape <literal>\</><replaceable>nnn</> would exceed 377 (255
+ decimal), assume it is a two-digit octal escape instead (Tom Lane)
+ </para>
+
+ <para>
+ This makes the behavior match current Tcl releases.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-07 [c5e86ea93] Add "xid <> xid" and "xid <> int4" operators.
+-->
+ <para>
+ Add <type>xid</> <literal><></> <type>xid</>
+ and <type>xid</> <literal><></> <type>int4</> operators,
+ for consistency with the corresponding <literal>=</> operators
+ (Michael Paquier)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Functions</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-04-06 [0b62fd036] Add jsonb_insert
+-->
+ <para>
+ Add <function>jsonb_insert()</> function to insert a new element into
+ a <type>jsonb</> array, or a not-previously-existing key into
+ a <type>jsonb</> object (Dmitry Dolgov)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-14 [7d9a4737c] Improve type numeric's calculations for ln(), log(), exp
+-->
+ <para>
+ Improve the accuracy of the <function>ln()</>, <function>log()</>,
+ <function>exp()</>, and <function>pow()</> functions for type
+ <type>numeric</> (Dean Rasheed)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-05 [abb173392] Add scale(numeric)
+-->
+ <para>
+ Add a <function>scale(numeric)</> function to extract the display
+ scale of a <type>numeric</> value (Marko Tiikkaja)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-22 [e1bd684a3] Add trigonometric functions that work in degrees.
+-->
+ <para>
+ Add trigonometric functions that work in degrees (Dean Rasheed)
+ </para>
+
+ <para>
+ For example, <function>sind()</> measures its argument in
+ degrees, whereas <function>sin()</> measures in radians.
+ These functions go to some lengths to deliver exact results for values
+ where an exact result can be expected, such
+ as <literal>sind(30) = 0.5</literal> exactly.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-22 [fd5200c3d] Improve cross-platform consistency of Inf/NaN handling i
+-->
+ <para>
+ Ensure that trigonometric functions handle infinity and NaN inputs per
+ spec (Dean Rasheed)
+ </para>
+
+ <para>
+ The POSIX standard says that these functions should return NaN for NaN
+ input, and should throw an error for out-of-range inputs including
+ infinity; but previously, our actual behavior varied across platforms.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-21 [647d87c56] Make extract() do something more reasonable with infinit
+-->
+ <para>
+ Make <function>extract()</> behave more reasonably with infinite
+ inputs (Vitaly Burovoy)
+ </para>
+
+ <para>
+ Historically the <function>extract()</> function just returned zero
+ given an infinite timestamp, regardless of the given unit name. Make
+ it return <literal>infinity</literal> or <literal>-infinity</literal>
+ as appropriate when the requested field is one that is monotonically
+ increasing (e.g, year, epoch), or NULL when it is not (e.g., day,
+ hour). Also, throw the expected error for bad unit names.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-29 [e511d878f] Allow to_timestamp(float8) to convert float infinity to
+-->
+ <para>
+ Make <function>to_timestamp(float8)</> convert float infinity to
+ timestamp infinity (Vitaly Burovoy)
+ </para>
+
+ <para>
+ Formerly it just failed on an infinite input.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-11 [6943a946c] Tsvector editing functions
+-->
+ <para>
+ Add new functions for <type>tsvector</> data (Stas Kelvich)
+ </para>
+
+ <para>
+ These are <function>delete()</>, <function>filter()</>,
+ <function>unnest()</>, <function>tsvector_to_array()</>,
+ <function>array_to_tsvector()</>, and a variant
+ of <function>setweight()</> that sets the weight only for specified
+ lexeme(s).
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-17 [9acb9007d] Fix oversight in tsearch type check
+-->
+ <para>
+ Allow <function>ts_stat_sql()</>
+ and <function>tsvector_update_trigger()</> to operate on values that
+ are of types binary-compatible with the expected argument type, not
+ just that argument type; for example allow <type>citext</>
+ where <type>text</> is expected (Teodor Sigaev)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-04 [6819514fc] Add num_nulls() and num_nonnulls() to count NULL argumen
+-->
+ <para>
+ Add variadic functions <function>num_nulls()</>
+ and <function>num_nonnulls()</> that count the number of their
+ arguments that are null or nonnull (Marko Tiikkaja)
+ </para>
+
+ <para>
+ An example usage is <literal>CHECK(num_nonnulls(a,b,c) = 1)</> which
+ asserts that exactly one of a,b,c isn't NULL. These functions can
+ also be pressed into service to count the number of null or nonnull
+ elements in an array.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-18 [3187d6de0] Introduce parse_ident()
+-->
+ <para>
+ Add function <function>parse_ident()</> to split a qualified,
+ possibly quoted SQL identifier into its parts (Pavel Stehule)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-05 [2d87eedc1] to_char(): Do not count negative sign as a digit for tim
+-->
+ <para>
+ In <function>to_char()</>, do not count a minus sign (when needed) as
+ part of the field width for time-related fields (Bruce Momjian)
+ </para>
+
+ <para>
+ For example, <literal>to_char('-4 years'::interval, 'YY')</> now
+ returns <literal>-04</>, rather than <literal>-4</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-05 [28b3a3d41] to_number(): allow 'V' to divide by 10^(the number of d
+-->
+ <para>
+ In <function>to_number()</>, interpret <literal>V</> as dividing by
+ 10 to the power of the number of digits following <literal>V</>
+ (Bruce Momjian)
+ </para>
+
+ <para>
+ This makes it operate in an inverse fashion to <function>to_char()</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-05 [ea0d494da] Make the to_reg*() functions accept text not cstring.
+-->
+ <para>
+ Make the <function>to_reg*()</> functions accept type <type>text</>
+ not <type>cstring</> (Petr Korobeinikov)
+ </para>
+
+ <para>
+ This avoids the need to write an explicit cast in most cases where
+ the argument isn't a simple literal constant.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-20 [53874c522] Add pg_size_bytes() to parse human-readable size strings
+-->
+ <para>
+ Add <function>pg_size_bytes()</> function to convert human-readable
+ size strings to numbers (Pavel Stehule, Vitaly Burovoy)
+ </para>
+
+ <para>
+ This function converts strings like those produced
+ by <function>pg_size_pretty()</> into sizes in bytes. An example
+ usage is <literal>WHERE pg_total_relation_size(oid) >
+ pg_size_bytes('10 GB')</>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-06 [8a1fab36a] pg_size_pretty: Format negative values similar to positi
+-->
+ <para>
+ In <function>pg_size_pretty()</>, format negative numbers similarly to
+ positive ones (Adrian Vondendriesch)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-02 [10fb48d66] Add an optional missing_ok argument to SQL function curr
+-->
+ <para>
+ Add an optional <replaceable>missing_ok</> argument to
+ the <function>current_setting()</> function (David Christensen)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Server-Side Languages</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-08-21 [fcdfce682] Detect mismatched CONTINUE and EXIT statements at plpgsq
+-->
+ <para>
+ In <link linkend="plpgsql">PL/pgSQL</link>,
+ detect mismatched <command>CONTINUE</> and <command>EXIT</> statements
+ while compiling PL/pgSQL functions, rather than at execution
+ (Jim Nasby)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-05 [0426f349e] Rearrange the handling of error context reports.
+This commit is also listed under libpq and psql
+-->
+ <para>
+ Remove PL/pgSQL's <quote>feature</> that suppressed the innermost line
+ of <literal>CONTEXT</> for messages emitted by <command>RAISE</>
+ commands (Pavel Stehule)
+ </para>
+
+ <para>
+ This ancient backwards-compatibility hack was agreed to have outlived
+ its usefulness.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [5c3c3cd0a] Enhanced custom error in PLPythonu
+-->
+ <para>
+ Extend PL/Python's error-reporting and message-reporting functions to
+ allow specifying additional message fields besides the primary error
+ message (Pavel Stehule)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-05 [1d2fe56e4] Fix PL/Python for recursion and interleaved set-returnin
+-->
+ <para>
+ Allow PL/Python functions to call themselves recursively via SPI,
+ and fix the behavior when multiple set-returning PL/Python functions
+ are called within one query (Alexey Grishchenko, Tom Lane)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-05 [8c75ad436] Fix memory leaks in PL/Python.
+-->
+ <para>
+ Fix session-lifespan memory leaks in PL/Python
+ (Heikki Linnakangas, Haribabu Kommi, Tom Lane)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-02 [287822068] Convert PL/Tcl to use Tcl's "object" interfaces.
+2016-03-02 [e2609323e] Make PL/Tcl require Tcl 8.4 or later.
+-->
+ <para>
+ Modernize <application>PL/Tcl</> to use Tcl's <quote>object</> APIs
+ instead of simple strings (Jim Nasby, Karl Lehenbauer)
+ </para>
+
+ <para>
+ This can improve performance substantially in some cases.
+ Note that <application>PL/Tcl</> now requires Tcl 8.4 or later.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-25 [fb8d2a7f5] In PL/Tcl, make database errors return additional info i
+2016-03-25 [cd37bb785] Improve PL/Tcl errorCode facility by providing decoded n
+-->
+ <para>
+ In <application>PL/Tcl</>, make database-reported errors return
+ additional information in Tcl's <varname>errorCode</> global variable
+ (Jim Nasby, Tom Lane)
+ </para>
+
+ <para>
+ This feature follows the Tcl convention for returning auxiliary data
+ about an error.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-02 [c8c7c93de] Fix PL/Tcl's encoding conversion logic.
+-->
+ <para>
+ Fix <application>PL/Tcl</> to perform encoding conversion between
+ the database encoding and UTF-8, which is what Tcl expects (Tom Lane)
+ </para>
+
+ <para>
+ Previously, strings were passed through without conversion, leading
+ to misbehavior with non-ASCII characters when the database encoding
+ isn't UTF-8.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Client Interfaces</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-09-05 [0426f349e] Rearrange the handling of error context reports.
+This commit is also listed under psql and PL/pgSQL
+-->
+ <para>
+ Introduce a feature in <application>libpq</> whereby
+ the <literal>CONTEXT</> field of messages can be suppressed, either
+ always or only for non-error messages (Pavel Stehule)
+ </para>
+
+ <para>
+ The default behavior of <function>PQerrorMessage()</> is now to
+ print <literal>CONTEXT</> only for errors. The new
+ function <function>PQsetErrorContextVisibility()</> can be used to
+ adjust this.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-03 [e3161b231] Add libpq support for recreating an error message with d
+-->
+ <para>
+ Add support in <application>libpq</> for regenerating an error
+ message with a different verbosity level (Alex Shulgin)
+ </para>
+
+ <para>
+ This supports <application>psql</>'s new <literal>\errverbose</>
+ feature, and may be useful for other clients as well.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-27 [40cb21f70] Improve PQhost() to return useful data for default Unix-
+-->
+ <para>
+ Improve <application>libpq</>'s <function>PQhost()</> function to
+ return useful data for default Unix-socket connections (Tom Lane)
+ </para>
+
+ <para>
+ Previously it would return NULL if no explicit host specification had
+ been given; now it returns the default socket directory path.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-16 [fc1ae7d2e] Change ecpg lexer to accept comments with line breaks in
+-->
+ <para>
+ Fix <application>ecpg</>'s lexer to handle line breaks within comments
+ starting on preprocessor directive lines (Michael Meskes)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Client Applications</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-09-14 [d02426029] Check existency of table/schema for -t/-n option (pg_dum
+-->
+ <para>
+ Add <option>--strict-names</> option to <application>pg_dump</>
+ and <application>pg_restore</> (Pavel Stehule)
+ </para>
+
+ <para>
+ This option causes the program to complain if there is no match for
+ a <option>-t</option> or <option>-n</option> option, rather than
+ silently doing nothing.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-06 [a9f0e8e5a] In pg_dump, use a bitmap to represent what to include
+2016-04-06 [d217b2c36] In pg_dump, split "dump" into "dump" and "dump_contains"
+2016-04-06 [23f34fa4b] In pg_dump, include pg_catalog and extension ACLs, if ch
+-->
+ <para>
+ In <application>pg_dump</>,
+ dump locally-made changes in privilege assignments for system objects
+ (Stephen Frost)
+ </para>
+
+ <para>
+ While it's always been possible for a superuser to change the
+ privilege assignments for built-in or extension-created objects,
+ such changes were formerly lost in a dump and reload. Now,
+ <application>pg_dump</> recognizes and dumps such changes.
+ (This works only when dumping from a 9.6 or later server, however.)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-06 [3b3fcc4ee] pg_dump: Add table qualifications to some tags
+-->
+ <para>
+ In <application>pg_dump</>, include the table name in object tags
+ for object types that are only uniquely named per-table (for
+ example, triggers) (Peter Eisentraut)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-02 [5671aaca8] Improve pg_restore's -t switch to match all types of rel
+-->
+ <para>
+ Improve <application>pg_restore</>'s <option>-t</option> switch to
+ match all types of relations, not only plain tables (Craig Ringer)
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <sect4>
+ <title><xref linkend="APP-PSQL"></title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-12-08 [d5563d7df] psql: Support multiple -c and -f options, and allow mixi
+-->
+ <para>
+ Support multiple <option>-c</option> and <option>-f</option>
+ command-line options (Pavel Stehule, Catalin Iacob)
+ </para>
+
+ <para>
+ To allow this with sane behavior, one backwards incompatibility had to
+ be introduced: <option>-c</option> no longer
+ implies <option>--no-psqlrc</option>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-08 [c09b18f21] Support \crosstabview in psql
+-->
+ <para>
+ Add a <command>\crosstabview</> command that prints the
+ results of a query in a cross-tabulated display
+ (Daniel Verité)
+ </para>
+
+ <para>
+ In the crosstab display, data values from one query result column are
+ placed in a grid whose column and row headers come from other query
+ result columns.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-03 [3cc38ca7d] Add psql \errverbose command to see last server error at
+-->
+ <para>
+ Add an <literal>\errverbose</> command that shows the last server
+ error at full verbosity (Alex Shulgin)
+ </para>
+
+ <para>
+ This is very handy after getting an unexpected error — you no
+ longer need to adjust the <varname>VERBOSITY</> variable and recreate
+ the failure in order to see error fields that aren't shown by
+ default.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-03 [8eb6407aa] Add psql \ev and \sv commands for editing and showing vi
+-->
+ <para>
+ Add <literal>\ev</> and <literal>\sv</> commands
+ for editing and showing view definitions (Petr Korobeinikov)
+ </para>
+
+ <para>
+ These are parallel to the existing <literal>\ef</> and <literal>\sf</>
+ commands for functions.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-04 [2bbe9112a] Add a \gexec command to psql for evaluation of computed
+-->
+ <para>
+ Add a <command>\gexec</> command that executes a query and re-submits
+ the result(s) as new queries (Corey Huinker)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-10-05 [2145a7660] psql: allow \pset C in setting the title, matches \C
+-->
+ <para>
+ Allow <literal>\pset C <replaceable>string</></literal> to set the
+ table title, for consistency
+ with <literal>\C <replaceable>string</></literal> (Bruce Momjian)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-11 [69ab7b9d6] psql: Don't automatically use expanded format when there
+-->
+ <para>
+ In <literal>\pset expanded auto</> mode, do not use expanded format
+ for query results with only one column (Andreas Karlsson, Robert Haas)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-21 [dea2b5960] Improve header output from psql's \watch command.
+-->
+ <para>
+ Improve the headers output by the <command>\watch</> command
+ (Michael Paquier, Tom Lane)
+ </para>
+
+ <para>
+ Include the <command>\pset title</> string if one has been set, and
+ shorten the prefabricated part of the header to be
+ <literal><replaceable>timestamp</> (every <replaceable>N</>s)</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-20 [d854118c8] Teach psql's tab completion to consider the entire input
+-->
+ <para>
+ Improve tab-completion logic to consider the
+ entire input query, not only the current line (Tom Lane)
+ </para>
+
+ <para>
+ Previously, breaking a command into multiple lines defeated any tab
+ completion rules that would have needed to see words on earlier lines.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-04 [158e3bc8e] Tab completion for CREATE SEQUENCE.
+2015-09-08 [3ae16798f] psql: Generic tab completion support for enum and bool G
+2015-09-09 [2f8880704] Improve tab-completion for GRANT and REVOKE.
+2015-10-01 [bf4817e4f] Fix incorrect tab-completion for GRANT and REVOKE
+2015-10-20 [7c0b49cd0] Tab complete CREATE EXTENSION .. VERSION.
+2015-12-25 [8014c44e8] Improve SECURITY LABEL tab completion
+2016-01-12 [bc56d5898] psql: Fix CREATE INDEX tab completion
+2016-01-12 [b1bfb28b5] psql: Improve CREATE INDEX CONCURRENTLY tab completion
+2016-01-16 [4189e3d65] psql: Add completion support for DROP INDEX CONCURRENTLY
+2016-01-20 [d0f2f53cd] psql: Add tab completion for COPY with query
+2016-01-23 [6ae4c8de0] psql: Improve completion of FDW DDL commands
+2016-01-26 [879d71393] Various fixes to REFRESH MATERIALIZED VIEW tab completio
+2016-02-01 [89611c4df] Various fixes to "ALTER ... SET/RESET" tab completions
+-->
+ <para>
+ Numerous minor improvements in tab-completion behavior (Peter
+ Eisentraut, Vik Fearing, Kevin Grittner, Kyotaro Horiguchi, Jeff
+ Janes, Andreas Karlsson, Fujii Masao, Thomas Munro, Masahiko Sawada,
+ Pavel Stehule)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-07 [275f05c99] Add psql PROMPT variable showing the pid of the connecte
+-->
+ <para>
+ Add a <literal>PROMPT</> option <literal>%p</> to
+ insert the process ID of the connected backend (Julien Rouhaud)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-05 [0426f349e] Rearrange the handling of error context reports.
+This commit is also listed under libpq and PL/pgSQL
+-->
+ <para>
+ Introduce a feature whereby the <literal>CONTEXT</> field of messages
+ can be suppressed, either always or only for non-error messages
+ (Pavel Stehule)
+ </para>
+
+ <para>
+ Printing <literal>CONTEXT</> only for errors is now the default
+ behavior. This can be changed by setting the special variable
+ <varname>SHOW_CONTEXT</varname>.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ <sect4>
+ <title><xref linkend="pgbench"></title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-03-20 [68ab8e8ba] SQL commands in pgbench scripts are now ended by semicol
+-->
+ <para>
+ SQL commands in <application>pgbench</> scripts are now ended by
+ semicolons, not newlines (Kyotaro Horiguchi, Tom Lane)
+ </para>
+
+ <para>
+ This change allows SQL commands in scripts to span multiple lines.
+ Existing custom scripts will need to be modified to add a semicolon
+ at the end of each line that does not have one already. (Doing so
+ does not break the script for use with older versions
+ of <application>pgbench</>.)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-01 [7e137f846] Extend pgbench's expression syntax to support a few buil
+2016-03-28 [86c43f4e2] pgbench: Support double constants and functions.
+-->
+ <para>
+ Support some <link linkend="pgbench-builtin-functions">built-in
+ functions</> in expressions in backslash commands (Fabien Coelho)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-29 [ad9566470] pgbench: Remove \setrandom.
+-->
+ <para>
+ Replace <command>\setrandom</> with built-in functions (Fabien Coelho)
+ </para>
+
+ <para>
+ The new built-in functions include <function>random()</>,
+ <function>random_exponential()</>, and <function>random_gaussian()</>,
+ which perform the same work as <command>\setrandom</>, but are easier
+ to use since they can be embedded in larger expressions. Since these
+ additions have made <command>\setrandom</> obsolete, remove it.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-27 [8bea3d221] pgbench: improve multi-script support
+2016-03-03 [d561f1cae] pgbench: accept unambiguous builtin prefixes for -b
+-->
+ <para>
+ Allow invocation of multiple copies of the built-in scripts, not only
+ custom scripts (Fabien Coelho)
+ </para>
+
+ <para>
+ This is done with the new <option>-b</> switch, which works similarly
+ to <option>-f</> for custom scripts.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-19 [7bafffea6] pgbench: Allow changing weights for scripts
+-->
+ <para>
+ Allow changing the selection probabilities (weights) for scripts
+ (Fabien Coelho)
+ </para>
+
+ <para>
+ When multiple scripts are specified, each <application>pgbench</>
+ transaction randomly chooses one to execute. Formerly this was
+ always done with uniform probability, but now different selection
+ probabilities can be specified for different scripts.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-01 [1d0c3b3f8] pgbench: allow per-script statistics
+-->
+ <para>
+ Collect statistics for each script in a multi-script run
+ (Fabien Coelho)
+ </para>
+
+ <para>
+ This feature adds an intermediate level of detail to existing global
+ and per-command statistics printouts.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-16 [1def9063c] pgbench progress with timestamp
+-->
+ <para>
+ Add a <option>--progress-timestamp</> option to report progress with
+ Unix epoch timestamps, instead of time since the run started
+ (Fabien Coelho)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-03 [ba3deeefb] Lift the limitation that # of clients must be a multiple
+-->
+ <para>
+ Allow the number of client connections (<option>-c</>) to not be an
+ exact multiple of the number of threads (<option>-t</>)
+ (Fabien Coelho)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-09 [accf7616f] pgbench: When -T is used, don't wait for transactions be
+-->
+ <para>
+ When the <option>-T</> option is used, stop promptly at the end of
+ the specified time (Fabien Coelho)
+ </para>
+
+ <para>
+ Previously, specifying a low transaction rate could
+ cause <application>pgbench</> to wait significantly longer than that.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ </sect3>
+
+ <sect3>
+ <title>Server Applications</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-12-17 [66d947b9d] Adjust behavior of single-user -j mode for better initdb
+-->
+ <para>
+ Improve error reporting during <application>initdb</>'s post-bootstrap
+ phase, by not reporting the entire input file as the <quote>failing
+ query</> (Tom Lane)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-17 [c4a8812cf] Use just one standalone-backend session for initdb's pos
+-->
+ <para>
+ Speed up <application>initdb</> by using just one standalone-backend
+ session for all the post-bootstrap steps (Tom Lane)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-01 [e50cda784] Use pg_rewind when target timeline was switched
+-->
+ <para>
+ Improve <application>pg_rewind</> so that it can work when the
+ target timeline changes (Alexander Korotkov)
+ </para>
+
+ <para>
+ This allows, for example, rewinding a promoted standby back to
+ some state of the old master's timeline.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Source Code</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-07-02 [726117243] Remove obsolete heap_formtuple/modifytuple/deformtuple f
+-->
+ <para>
+ Remove obsolete <function>heap_formtuple</>/<function>heap_modifytuple</>/<function>heap_deformtuple</>
+ functions (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-05 [de6fd1c89] Rely on inline functions even if that causes warnings in
+-->
+ <para>
+ Unconditionally use <literal>static inline</> functions in header
+ files (Andres Freund)
+ </para>
+
+ <para>
+ This may result in warnings and/or wasted code space with very old
+ compilers, but the notational improvement seems worth it.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-29 [13d856e17] Make TAP tests work on Windows.
+2015-12-02 [1caef31d9] Refactor Perl test code
+2015-12-07 [9821492ee] Cleanup some problems in new Perl test code
+2016-03-03 [2c83f435a] Rework PostgresNode's psql method
+2016-02-26 [49148645f] Add a test framework for recovery
+2016-02-26 [74d58425c] Apply last revision of recovery patch
+-->
+ <para>
+ Improve TAP testing infrastructure
+ (Michael Paquier, Craig Ringer, Álvaro Herrera)
+ </para>
+
+ <para>
+ Notably, it is now possible to test recovery scenarios using this
+ infrastructure.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-11 [aa65de042] When trace_lwlocks is used, identify individual lwlocks
+-->
+ <para>
+ Make <varname>trace_lwlocks</> identify individual locks by name
+ (Robert Haas)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-19 [d37b816dc] Adopt a more compact, less error-prone notation for tab
+2016-01-04 [9b181b036] In psql's tab completion, change most TailMatches patter
+2016-01-05 [4f18010af] Convert psql's tab completion for backslash commands to
+-->
+ <para>
+ Improve <application>psql</>'s tab-completion code infrastructure
+ (Thomas Munro, Michael Paquier)
+ </para>
+
+ <para>
+ Tab-completion rules are now considerably easier to write, and more
+ compact.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-05 [efa318bcf] Make pg_shseclabel available in early backend startup
+-->
+ <para>
+ Nail the <structname>pg_shseclabel</> system catalog into cache,
+ so that it is available for access during connection authentication
+ (Adam Brightwell)
+ </para>
+
+ <para>
+ The core code doesn't use this catalog for authentication, but
+ extensions might wish to consult it.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-17 [65c5fcd35] Restructure index access method API to hide most of it a
+2016-01-21 [be44ed27b] Improve index AMs' opclass validation procedures.
+-->
+ <para>
+ Restructure index access method API to hide most of it at the C level
+ (Alexander Korotkov)
+ </para>
+
+ <para>
+ This change modernizes the index AM API to look more like the designs
+ we've adopted for foreign data wrappers and tablesample handlers.
+ This simplifies the C code and should make it more feasible to define
+ index access methods in installable extensions. A consequence is
+ that most of the columns of the <structname>pg_am</> system catalog
+ have disappeared.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-06 [6c268df12] Add new catalog called pg_init_privs
+-->
+ <para>
+ Add <structname>pg_init_privs</> system catalog to hold original
+ privileges of <application>initdb</>-created and extension-created
+ objects (Stephen Frost)
+ </para>
+
+ <para>
+ This infrastructure allows <application>pg_dump</> to dump changes
+ that an installation may have made in privileges attached to system
+ objects. Formerly, such changes would be lost in a dump and reload,
+ but now they can be preserved.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-03 [b47b4dbf6] Extend sortsupport for text to more opclasses.
+-->
+ <para>
+ Generalize the SortSupport for <type>text</> so that it can be
+ used by other types such as <type>bpchar</> (Peter Geoghegan)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-04 [c1772ad92] Change the way that LWLocks for extensions are allocated
+-->
+ <para>
+ Change the way that extensions allocate custom LWLocks
+ (Amit Kapila, Robert Haas)
+ </para>
+
+ <para>
+ The <function>RequestAddinLWLocks()</> function is removed, and
+ replaced by <function>RequestNamedLWLockTranche()</>. This allows
+ better identification of custom LWLocks, and is less error-prone.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-11 [38f8bdcac] Modify the isolation tester so that multiple sessions ca
+-->
+ <para>
+ Improve the isolation tester to allow multiple sessions to wait
+ concurrently, allowing testing of deadlock scenarios (Robert Haas)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-12 [bcac23de7] Introduce extensible node types.
+-->
+ <para>
+ Introduce extensible node types (KaiGai Kohei)
+ </para>
+
+ <para>
+ This change allows FDWs or custom scan providers to store data in a
+ plan tree in a more convenient format than was previously possible.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-08-11 [68fa28f77] Postpone extParam/allParam calculations until the very e
+2016-01-07 [c44d01383] Delay creation of subplan tlist until after create_plan(
+2016-02-18 [19a541143] Add an explicit representation of the output targetlist
+2016-03-07 [3fc6e2d7f] Make the upper part of the planner work by generating an
+-->
+ <para>
+ Make the planner deal with post-scan/join query steps by generating
+ and comparing Paths, replacing a lot of very ad-hoc logic (Tom Lane)
+ </para>
+
+ <para>
+ This change provides only marginal user-visible improvements today,
+ but it enables future work on a lot of upper-planner improvements
+ that were impractical to tackle in the old code structure.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-20 [a7de3dc5c] Support multi-stage aggregation.
+-->
+ <para>
+ Support partial aggregation (David Rowley, Simon Riggs)
+ </para>
+
+ <para>
+ This change allows the computation of an aggregate function to be
+ split into separate parts, for example so that parallel worker
+ processes can cooperate on computing an aggregate. In future it
+ might allow aggregation across local and remote data to occur
+ partially on the remote end.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-09 [b6fb6471f] Add a generic command progress reporting facility.
+-->
+ <para>
+ Add a generic command progress reporting facility (Vinayak Pokale,
+ Rahila Syed, Amit Langote, Robert Haas)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-18 [27199058d] Convert psql's flex lexer to be re-entrant, and make it
+2016-03-19 [0ea9efbe9] Split psql's lexer into two separate .l files for SQL an
+2016-03-20 [b6afae71a] Use %option bison-bridge in psql/pgbench lexers.
+2016-03-24 [588d963b0] Create src/fe_utils/, and move stuff into there from pg_
+2016-03-24 [d65bea26a] Move psql's print.c and mbprint.c into src/fe_utils.
+2016-03-24 [c1156411a] Move psql's psqlscan.l into src/fe_utils.
+-->
+ <para>
+ Separate out <application>psql</>'s flex lexer to make it usable by
+ other client programs too (Tom Lane, Kyotaro Horiguchi)
+ </para>
+
+ <para>
+ This eliminates code duplication for programs that need to be able
+ to parse SQL commands well enough to identify command boundaries.
+ Doing that in full generality is more painful than one could wish,
+ and up to now only <application>psql</> has really gotten it right
+ among our supported client programs.
+ </para>
+
+ <para>
+ A new source-code subdirectory <filename>src/fe_utils/</> has been
+ created to hold this and other code that's shared across our client
+ programs. Formerly such sharing was accomplished by symlinking or
+ copying source files at build time, which was ugly and required
+ duplicate compilation work.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-21 [98a64d0bd] Introduce WaitEventSet API.
+-->
+ <para>
+ Introduce WaitEventSet API to allow efficient waiting for event
+ sets that usually don't change from one wait to the next
+ (Andres Freund, Amit Kapila)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-01 [65578341a] Add Generic WAL interface
+-->
+ <para>
+ Add a generic interface for writing WAL records
+ (Alexander Korotkov, Petr Jelínek, Markus Nullmeier)
+ </para>
+
+ <para>
+ This change allows extensions to write WAL records for changes to
+ pages with standard layout. The problem of needing to replay WAL
+ without access to the extension is solved by having generic replay
+ code. This allows extensions to implement, for example, index access
+ methods and have WAL support for them.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-06 [3fe3511d0] Generic Messages for Logical Decoding
+-->
+ <para>
+ Support generic WAL messages for logical decoding
+ (Petr Jelínek, Andres Freund)
+ </para>
+
+ <para>
+ This feature allows extensions to insert data into the WAL stream
+ that can be read by logical-decoding plugins, but is not connected to
+ physical data restoration.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-30 [ccd6eb49a] Introduce traversalValue for SP-GiST scan
+2016-03-30 [87545f541] Use traversalValue in SP-GiST range opclass.
+-->
+ <para>
+ Allow SP-GiST operator classes to store an arbitrary <quote>traversal
+ value</> while descending the index (Alexander Lebedev, Teodor Sigaev)
+ </para>
+
+ <para>
+ This is somewhat like the <quote>reconstructed value</>, but it could
+ be any arbitrary chunk of data, it need not be of the same data type
+ as the indexed column.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-04 [66229ac00] Introduce a LOG_SERVER_ONLY ereport level, which is neve
+-->
+ <para>
+ Introduce a <literal>LOG_SERVER_ONLY</> message level
+ for <function>ereport()</> (David Steele)
+ </para>
+
+ <para>
+ This level acts like <literal>LOG</> except that the message is never
+ sent to the client. It's meant for use in auditing and similar
+ applications.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Additional Modules</title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2016-03-11 [92f03fe76] Allow setting sample ratio for auto_explain
+2016-03-13 [7a8d87483] Rename auto_explain.sample_ratio to sample_rate
+-->
+ <para>
+ Add configuration parameter <literal>auto_explain.sample_rate</>
+ to allow <filename>contrib/auto_explain</> to capture just a
+ configurable fraction of all queries (Craig Ringer, Julien Rouhaud)
+ </para>
+
+ <para>
+ This allows reduction of overhead for heavy query traffic, while
+ still getting useful information on average.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-01 [9ee014fc8] Bloom index contrib module
+-->
+ <para>
+ Add <filename>contrib/bloom</> module that implements an index access
+ method based on Bloom filtering (Teodor Sigaev, Alexander Korotkov)
+ </para>
+
+ <para>
+ This is primarily a proof-of-concept for non-core index access
+ methods, but it could be useful in its own right for queries that
+ involve searches on many columns.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-18 [33bd250f6] Cube extension kNN support
+2015-12-28 [81ee726d8] Code and docs review for cube kNN support.
+-->
+ <para>
+ In <filename>contrib/cube</>, introduce distance operators for cubes,
+ and support kNN-style searches in GiST indexes on cube columns
+ (Stas Kelvich)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-03 [41d2c081c] Make hstore_to_jsonb_loose match hstore_to_json_loose on
+-->
+ <para>
+ Make <filename>contrib/hstore</>'s <function>hstore_to_jsonb_loose()</>
+ and <function>hstore_to_json_loose()</> functions agree on what's a
+ number (Tom Lane)
+ </para>
+
+ <para>
+ Previously, <function>hstore_to_jsonb_loose()</> would convert
+ numeric-looking strings to JSON numbers, rather than strings, even if
+ they did not exactly match the JSON syntax specification for numbers.
+ This was inconsistent with <function>hstore_to_json_loose()</>, so
+ tighten the test to match the JSON syntax.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-21 [c6fbe6d6f] Add selectivity estimation functions for intarray operat
+-->
+ <para>
+ Add selectivity estimation functions for <filename>contrib/intarray</>
+ operators, to improve plans for queries using those operators (Uriy
+ Zhuravlev, Alexander Korotkov)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-25 [d6061f83a] Improve pageinspect module
+-->
+ <para>
+ Make <filename>contrib/pageinspect</>'s <function>heap_page_items()</>
+ function show the raw data in each tuple, and add new
+ functions <function>tuple_data_split()</>
+ and <function>heap_page_item_attrs()</> for inspection of individual
+ tuple fields (Nikolay Shaplov)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-09 [188f359d3] pgcrypto: support changing S2K iteration count
+-->
+ <para>
+ Add an optional S2K iteration count parameter
+ to <filename>contrib/pgcrypto</>'s <function>pgp_sym_encrypt()</>
+ function (Jeff Janes)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-16 [f576b17cd] Add word_similarity to pg_trgm contrib module.
+-->
+ <para>
+ Add support for <quote>word similarity</>
+ to <filename>contrib/pg_trgm</>
+ (Alexander Korotkov, Artur Zakirov)
+ </para>
+
+ <para>
+ These functions and operators measure the similarity between one
+ string and the most similar single word of another string.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-16 [5871b8848] GUC variable pg_trgm.similarity_threshold insead of set_
+-->
+ <para>
+ Add configuration parameter <varname>pg_trgm.similarity_threshold</>
+ for <filename>contrib/pg_trgm</>'s similarity threshold
+ (Artur Zakirov)
+ </para>
+
+ <para>
+ This threshold has always been configurable, but formerly it was
+ controlled by special-purpose functions <function>set_limit()</>
+ and <function>show_limit()</>. Those are now deprecated.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-07-20 [97f301464] This supports the triconsistent function for pg_trgm GIN
+-->
+ <para>
+ Improve <filename>contrib/pg_trgm</>'s GIN operator class to speed up
+ index searches in which both common and rare keys appear (Jeff Janes)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-12-25 [25bfa7efd] Improve the gin index scan performance in pg_trgm.
+-->
+ <para>
+ Improve performance of similarity searches in
+ <filename>contrib/pg_trgm</> GIN indexes (Christophe Fornaroli)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-08 [ba0a198fb] Add pg_visibility contrib module.
+-->
+ <para>
+ Add <filename>contrib/pg_visibility</> module to allow examining
+ table visibility maps (Robert Haas)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-07 [49124613f] contrib/sslinfo: add ssl_extension_info SRF
+-->
+ <para>
+ Add <function>ssl_extension_info()</> function
+ to <filename>contrib/sslinfo</>, to print information about SSL
+ extensions present in the X509 certificate used for the current
+ connection (Dmitry Voronin)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-09-04 [1bbd52cb9] Make unaccent handle all diacritics known to Unicode, an
+2016-03-16 [9a206d063] Improve script generating unaccent rules
+-->
+ <para>
+ Extend <filename>contrib/unaccent</>'s
+ standard <filename>unaccent.rules</> file to handle all diacritics
+ known to Unicode, and expand ligatures correctly
+ (Thomas Munro, Leonard Benedetti)
+ </para>
+
+ <para>
+ The previous version omitted some less-common letters with diacritic
+ marks. It now also expands ligatures into separate letters.
+ Installations that use this rules file may wish to
+ rebuild <type>tsvector</> columns and indexes that depend on the
+ result.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ <sect4>
+ <title><filename>postgres_fdw</></title>
+
+ <itemizedlist>
+
+ <listitem>
+<!--
+2015-11-03 [d89494166] Allow postgres_fdw to ship extension funcs/operators for
+-->
+ <para>
+ Allow extension-provided operators and functions to be sent for
+ remote execution, if the extension is whitelisted in the foreign
+ server's options (Paul Ramsey)
+ </para>
+
+ <para>
+ Users can enable this feature when the extension is known to exist in
+ a compatible version in the remote database. It allows more efficient
+ execution of queries involving extension operators.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-01-28 [96198d94c] Avoid multiple foreign server connections when all use s
+-->
+ <para>
+ Use a single foreign-server connection for local user IDs that all
+ map to the same remote user (Ashutosh Bapat)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-03 [dc203dc3a] postgres_fdw: Allow fetch_size to be set per-table or pe
+-->
+ <para>
+ Allow the fetch size to be set as a server or table option
+ (Corey Huinker)
+ </para>
+
+ <para>
+ Formerly, <filename>postgres_fdw</> always fetched 100 rows at a time
+ from remote queries; now that behavior is adjustable.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2015-11-03 [f18c944b6] postgres_fdw: Add ORDER BY to some remote SQL queries.
+2015-12-22 [ccd8f9792] postgres_fdw: Consider requesting sorted data so we can
+-->
+ <para>
+ Consider performing sorts on the remote server (Ashutosh Bapat)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-02-09 [e4106b252] postgres_fdw: Push down joins to remote servers.
+2016-03-09 [aa09cd242] postgres_fdw: Consider foreign joining and foreign sorti
+-->
+ <para>
+ Push down joins to the remote server when possible (Shigeru Hanada,
+ Ashutosh Bapat)
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-03-18 [0bf3ae88a] Directly modify foreign tables.
+-->
+ <para>
+ When feasible, perform <command>UPDATE</> or <command>DELETE</>
+ entirely on the remote server (Etsuro Fujita)
+ </para>
+
+ <para>
+ Formerly, this involved sending a <command>SELECT FOR UPDATE</>
+ command and then updating or deleting the selected rows one-by-one.
+ While that's still necessary if the operation requires any local
+ processing, it can now be done remotely if all elements of the query
+ are safe to send to the remote server.
+ </para>
+ </listitem>
+
+ <listitem>
+<!--
+2016-04-21 [f039eaac7] Allow queries submitted by postgres_fdw to be canceled.
+-->
+ <para>
+ Transmit query cancellation requests to the remote server
+ (Michael Paquier)
+ </para>
+
+ <para>
+ Previously, a local query cancellation request did nothing to cause
+ an already-sent remote query to terminate early.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect4>
+
+ </sect3>
+
+ </sect2>
+
+ </sect1>
projects / postgresql / commitdiff