Release date: 2016-10-27
This release contains a variety of fixes from 9.2.18. For information about new features in the 9.2 major release, see Section E.97.
A dump/restore is not required for those running 9.2.X.
However, if you are upgrading from a version earlier than 9.2.11, see Section E.86.
Fix EvalPlanQual rechecks involving CTE scans (Tom Lane)
The recheck would always see the CTE as returning no rows, typically leading to failure to update rows that were recently updated.
Fix improper repetition of previous results from hashed aggregation in a subquery (Andrew Gierth)
The test to see if we can reuse a previously-computed hash table of the aggregate state values neglected the possibility of an outer query reference appearing in an aggregate argument expression. A change in the value of such a reference should lead to recalculating the hash table, but did not.
      Fix EXPLAIN to emit valid XML when
      track_io_timing is on (Markus Winand)
     
      Previously the XML output-format option produced syntactically invalid
      tags such as <I/O-Read-Time>.  That is now
      rendered as <I-O-Read-Time>.
     
      Suppress printing of zeroes for unmeasured times
      in EXPLAIN (Maksim Milyutin)
     
      Certain option combinations resulted in printing zero values for times
      that actually aren't ever measured in that combination.  Our general
      policy in EXPLAIN is not to print such fields at all, so
      do that consistently in all cases.
     
      Fix timeout length when VACUUM is waiting for exclusive
      table lock so that it can truncate the table (Simon Riggs)
     
      The timeout was meant to be 50 milliseconds, but it was actually only
      50 microseconds, causing VACUUM to give up on truncation
      much more easily than intended.  Set it to the intended value.
     
      Fix bugs in merging inherited CHECK constraints while
      creating or altering a table (Tom Lane, Amit Langote)
     
      Allow identical CHECK constraints to be added to a parent
      and child table in either order.  Prevent merging of a valid
      constraint from the parent table with a NOT VALID
      constraint on the child.  Likewise, prevent merging of a NO
      INHERIT child constraint with an inherited constraint.
     
      Remove artificial restrictions on the values accepted
      by numeric_in() and numeric_recv()
      (Tom Lane)
     
      We allow numeric values up to the limit of the storage format (more
      than 1e100000), so it seems fairly pointless
      that numeric_in() rejected scientific-notation exponents
      above 1000.  Likewise, it was silly for numeric_recv() to
      reject more than 1000 digits in an input value.
     
Avoid very-low-probability data corruption due to testing tuple visibility without holding buffer lock (Thomas Munro, Peter Geoghegan, Tom Lane)
Fix file descriptor leakage when truncating a temporary relation of more than 1GB (Andres Freund)
      Disallow starting a standalone backend with standby_mode
      turned on (Michael Paquier)
     
This can't do anything useful, since there will be no WAL receiver process to fetch more WAL data; and it could result in misbehavior in code that wasn't designed with this situation in mind.
Don't try to share SSL contexts across multiple connections in libpq (Heikki Linnakangas)
This led to assorted corner-case bugs, particularly when trying to use different SSL parameters for different connections.
Avoid corner-case memory leak in libpq (Tom Lane)
      The reported problem involved leaking an error report
      during PQreset(), but there might be related cases.
     
      Make ecpg's --help and --version
      options work consistently with our other executables (Haribabu Kommi)
     
In pg_dump, never dump range constructor functions (Tom Lane)
This oversight led to pg_upgrade failures with extensions containing range types, due to duplicate creation of the constructor functions.
      Fix contrib/intarray/bench/bench.pl to print the results
      of the EXPLAIN it does when given the -e option
      (Daniel Gustafsson)
     
Update Windows time zone mapping to recognize some time zone names added in recent Windows versions (Michael Paquier)
Prevent failure of obsolete dynamic time zone abbreviations (Tom Lane)
      If a dynamic time zone abbreviation does not match any entry in the
      referenced time zone, treat it as equivalent to the time zone name.
      This avoids unexpected failures when IANA removes abbreviations from
      their time zone database, as they did in tzdata
      release 2016f and seem likely to do again in the future.  The
      consequences were not limited to not recognizing the individual
      abbreviation; any mismatch caused
      the pg_timezone_abbrevs view to fail altogether.
     
Update time zone data files to tzdata release 2016h for DST law changes in Palestine and Turkey, plus historical corrections for Turkey and some regions of Russia. Switch to numeric abbreviations for some time zones in Antarctica, the former Soviet Union, and Sri Lanka.
      The IANA time zone database previously provided textual abbreviations
      for all time zones, sometimes making up abbreviations that have little
      or no currency among the local population.  They are in process of
      reversing that policy in favor of using numeric UTC offsets in zones
      where there is no evidence of real-world use of an English
      abbreviation.  At least for the time being, PostgreSQL
      will continue to accept such removed abbreviations for timestamp input.
      But they will not be shown in the pg_timezone_names
      view nor used for output.
     
      In this update, AMT is no longer shown as being in use to
      mean Armenia Time.  Therefore, we have changed the Default
      abbreviation set to interpret it as Amazon Time, thus UTC-4 not UTC+4.