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== PostgreSQL Weekly News - August 21 2017 ==

From: David Fetter <david(at)fetter(dot)org>
To: PostgreSQL Announce <pgsql-announce(at)postgresql(dot)org>
Subject: == PostgreSQL Weekly News - August 21 2017 ==
Date: 2017-08-21 04:01:27
Message-ID: 20170821040127.GA10590@fetter.org (view raw, whole thread or download thread mbox)
Thread:
Lists: pgsql-announce
== PostgreSQL Weekly News - August 21 2017 ==

PGDay Australia 2017 will be held on November 17 in Melbourne.  The CfP is open
through September 8, 2017 at https://goo.gl/5d9EbT
http://2017.pgday.com.au/

== PostgreSQL Jobs for August ==

http://archives.postgresql.org/pgsql-jobs/2017-08/

== PostgreSQL Local ==

PGDay Austin 2017 will be held on August 26, 2017
https://pgdayaustin2017.postgresql.us

PostgresOpen will occur September 6-8, 2017 in San Francisco.
https://2017.postgresopen.org/

PGBR2017 will take place in Porto Alegre, Rio Grande do Sul,
Brazil on September 14-16 2017.
https://pgbr.postgresql.org.br/2017/

PGDay.IT 2017 will take place in October 13th, in Milan, Italy.
http://pgday.it

PostgreSQL Conference Europe 2017 will be held on October 24-27, 2017 in the
Warsaw Marriott Hotel, in Warsaw, Poland.
https://2017.pgconf.eu/

PGConf Local: Seattle will be held November 13 - 14, 2017.
https://www.pgconf.us/#Seattle2017

PGConf Local: Austin will be held December 4 - 5, 2017. Call for Papers is
now open at https://www.pgconf.us/conferences/Austin2017

PGConf.ASIA 2017 will take place on December 4-6 2017 in Akihabara, Tokyo,
Japan.
http://www.pgconf.asia/EN/2017/

== PostgreSQL in the News ==

Planet PostgreSQL: http://planet.postgresql.org/

PostgreSQL Weekly News is brought to you this week by David Fetter

Submit news and announcements by Sunday at 3:00pm Pacific time.
Please send English language ones to david(at)fetter(dot)org, German language
to pwn(at)pgug(dot)de, Italian language to pwn(at)itpug(dot)org(dot)

== Applied Patches ==

Michael Meskes pushed:

- Changed ecpg parser to allow RETURNING clauses without attached C variables.
  https://git.postgresql.org/pg/commitdiff/ea0ca75d5d14e0c98782a2188405685af4a475a0

- Allow continuation lines in ecpg cppline parsing.
  https://git.postgresql.org/pg/commitdiff/a4619b26a6a69ab31cab4a0632460647d7f5510f

Tom Lane pushed:

- Absorb -D USE 32BIT TIME T switch from Perl, if relevant.  Commit 3c163a7fc's
  original choice to ignore all #define symbols whose names begin with
  underscore turns out to be too simplistic.  On Windows, some Perl
  installations are built with -D USE 32BIT TIME T, and we must absorb that or
  we get the wrong result for sizeof(PerlInterpreter).  This effectively
  re-reverts commit ef58b87df, which injected that symbol in a hacky way, making
  it apply to all of Postgres not just PL/Perl.  More significantly, it did so
  on *all* 32-bit Windows builds, even when the Perl build to be used did not
  select this option; so that it fails to work properly with some newer Perl
  builds.  By making this change, we would be introducing an ABI break in 32-bit
  Windows builds; but fortunately we have not used type time t in any exported
  Postgres APIs in a long time.  So it should be OK, both for PL/Perl itself and
  for third-party extensions, if an extension library is built with a different
   USE 32BIT TIME T setting than the core code.  Patch by me, based on research
  by Ashutosh Sharma and Robert Haas.  Back-patch to all supported branches, as
  commit 3c163a7fc was.  Discussion:
  https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/5a5c2feca3fd858e70ea348822595547e6fa6c15

- Handle elog(FATAL) during ROLLBACK more robustly.  Stress testing by Andreas
  Seltenreich disclosed longstanding problems that occur if a FATAL exit (e.g.
  due to receipt of SIGTERM) occurs while we are trying to execute a ROLLBACK of
  an already-failed transaction.  In such a case, xact.c is in TBLOCK ABORT
  state, so that AbortOutOfAnyTransaction would skip AbortTransaction and go
  straight to CleanupTransaction.  This led to an assert failure in an
  assert-enabled build (due to the ROLLBACK's portal still having a cleanup
  hook) or without assertions, to a FATAL exit complaining about "cannot drop
  active portal".  The latter's not disastrous, perhaps, but it's messy enough
  to want to improve it.  We don't really want to run all of AbortTransaction in
  this code path.  The minimum required to clean up the open portal safely is to
  do AtAbort Memory and AtAbort Portals.  It seems like a good idea to do
  AtAbort Memory unconditionally, to be entirely sure that we are starting with
  a safe CurrentMemoryContext.  That means that if the main loop in
  AbortOutOfAnyTransaction does nothing, we need an extra step at the bottom to
  restore CurrentMemoryContext = TopMemoryContext, which I chose to do by
  invoking AtCleanup Memory.  This'll result in calling AtCleanup Memory twice
  in many of the paths through this function, but that seems harmless and
  reasonably inexpensive.  The original motivation for the assertion in
  AtCleanup Portals was that we wanted to be sure that any user-defined code
  executed as a consequence of the cleanup hook runs during AbortTransaction not
  CleanupTransaction.  That still seems like a valid concern, and now that we've
  seen one case of the assertion firing --- which means that exactly that would
  have happened in a production build --- let's replace the Assert with a
  runtime check.  If we see the cleanup hook still set, we'll emit a WARNING and
  just drop the hook unexecuted.  This has been like this a long time, so
  back-patch to all supported branches.  Discussion:
  https://postgr.es/m/877ey7bmun.fsf@ansel.ydns.eu
  https://git.postgresql.org/pg/commitdiff/5b6289c1e07dc45f09c3169a189e60d2fcaec2b3

- Final pgindent + perltidy run for v10.
  https://git.postgresql.org/pg/commitdiff/21d304dfedb4f26d0d6587d9ac39b1b5c499bb55

- Stamp HEAD as 11devel.  Note that we no longer require any manual adjustments
  to shared-library minor version numbers, cf commit a3bce17ef.  So this should
  be everything.
  https://git.postgresql.org/pg/commitdiff/9f14dc393bd441dd9251bea2a5a3ad7f889b03c5

- Distinguish wait-for-connection from wait-for-write-ready on Windows.  The API
  for WaitLatch and friends followed the Unix convention in which waiting for a
  socket connection to complete is identical to waiting for the socket to accept
  a write.  While Windows provides a select(2) emulation that agrees with that,
  the native WaitForMultipleObjects API treats them as quite different --- and
  for some bizarre reason, it will report a not-yet-connected socket as
  write-ready.  libpq itself has so far escaped dealing with this because it
  waits with select(), but in libpqwalreceiver.c we want to wait using
  WaitLatchOrSocket.  The semantics mismatch resulted in replication connection
  failures on Windows, but only for remote connections (apparently, localhost
  connections complete immediately, or at least too fast for anyone to have
  noticed the problem in single-machine testing).  To fix, introduce an
  additional WL SOCKET CONNECTED wait flag for WaitLatchOrSocket, which is
  identical to WL SOCKET WRITEABLE on non-Windows, but results in waiting for
  FD CONNECT events on Windows.  Ideally, we would also distinguish the two
  conditions in the API for PQconnectPoll(), but changing that API at this point
  seems infeasible.  Instead, cheat by checking for PQstatus() ==
  CONNECTION STARTED to determine that we're still waiting for the connection to
  complete.  (This is a cheat mainly because CONNECTION STARTED is documented as
  an internal state rather than something callers should rely on.  Perhaps we
  ought to change the documentation ... but this patch doesn't.) Per reports
  from Jobin Augustine and Igor Neyman.  Back-patch to v10 where commit
  1e8a85009 exposed this longstanding shortcoming.  Andres Freund, minor fix and
  some code review/beautification by me Discussion:
  https://postgr.es/m/CAHBggj8g2T+ZDcACZ2FmzX9CTxkWjKBsHd6NkYB4i9Ojf6K1Fw@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/f3a4d7e7c290ba630ba0e6e6f009ac27cd3feb03

- Simplify plpgsql's check for simple expressions.  plpgsql wants to recognize
  expressions that it can execute directly via ExecEvalExpr() instead of going
  through the full SPI machinery.  Originally the test for this consisted of
  recursively groveling through the post-planning expression tree to see if it
  contained only nodes that plpgsql recognized as safe.  That was a major
  maintenance headache, since it required updating plpgsql every time we added
  any kind of expression node.  It was also kind of expensive, so over time we
  added various pre-planning checks to try to short-circuit having to do that.
  Robert Haas pointed out that as of the SRF-processing changes in v10,
  particularly the addition of Query.hasTargetSRFs, there really isn't any
  reason to make the recursive scan at all: the initial checks cover everything
  we really care about.  We do have to make sure that those checks agree with
  what inline function() considers, so that inlining of a function that formerly
  wasn't inlined can't cause an expression considered simple to become
  non-simple.  Hence, delete the recursive function exec simple check node(),
  and tweak those other tests to more exactly agree with inline function().
  Adjust some comments and function naming to match.  Discussion:
  https://postgr.es/m/CA+TgmoZGZpwdEV2FQWaVxA qZXsQE1DAS5Fu8fwxXDNvfndiUQ(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/00418c61244138bd8ac2de58076a1d0dd4f539f3

- Avoid out-of-memory in a hash join with many duplicate inner keys.  The
  executor is capable of splitting buckets during a hash join if too much memory
  is being used by a small number of buckets.  However, this only helps if a
  bucket's population is actually divisible; if all the hash keys are alike, the
  tuples still end up in the same new bucket.  This can result in an OOM failure
  if there are enough inner keys with identical hash values.  The planner's cost
  estimates will bias it against choosing a hash join in such situations, but
  not by so much that it will never do so.  To mitigate the OOM hazard,
  explicitly estimate the hash bucket space needed by just the inner side's most
  common value, and if that would exceed work mem then add disable cost to the
  hash cost estimate.  This approach doesn't account for the possibility that
  two or more common values would share the same hash value.  On the other hand,
  work mem is normally a fairly conservative bound, so that eating two or more
  times that much space is probably not going to kill us.  If we have no stats
  about the inner side, ignore this consideration.  There was some discussion of
  making a conservative assumption, but that would effectively result in
  disabling hash join whenever we lack stats, which seems like an overreaction
  given how seldom the problem manifests in the field.  Per a complaint from
  David Hinkle.  Although this could be viewed as a bug fix, the lack of similar
  complaints weighs against back- patching; indeed we waited for v11 because it
  seemed already rather late in the v10 cycle to be making plan choice changes
  like this one.  Discussion: https://postgr.es/m/32013.1487271761@sss.pgh.pa.us
  https://git.postgresql.org/pg/commitdiff/4867d7f62f7363909526d84d8fa1e9cf434cffc6

- Make simpler-simple-expressions code cope with a Gather plan.  Commit
  00418c612 expected that the plan generated for a simple-expression query would
  always be a plain Result node.  However, if force parallel mode is on, the
  planner might stick a Gather atop that.  Cope by looking through the Gather.
  For safety, assert that the Gather's tlist is trivial.  Per buildfarm.
  Discussion: https://postgr.es/m/23425.1502822098@sss.pgh.pa.us
  https://git.postgresql.org/pg/commitdiff/b73f1b5c29e0ace5a281bc13ce09dea30e1b66de

- Make the planner assume that the entries in a VALUES list are distinct.
  Previously, if we had to estimate the number of distinct values in a VALUES
  column, we fell back on the default behavior used whenever we lack statistics,
  which effectively is that there are Min(# of entries, 200) distinct values.
  This can be very badly off with a large VALUES list, as noted by Jeff Janes.
  We could consider actually running an ANALYZE-like scan on the VALUES, but
  that seems unduly expensive, and anyway it could not deliver reliable info if
  the entries are not all constants.  What seems like a better choice is to
  assume that the values are all distinct.  This will sometimes be just as wrong
  as the old code, but it seems more likely to be more nearly right in many
  common cases.  Also, it is more consistent with what happens in some related
  cases, for example WHERE x = ANY(ARRAY[1,2,3,...,n]) and WHERE x = ANY(VALUES
  (1),(2),(3),...,(n)) now are estimated similarly.  This was discussed some
  time ago, but consensus was it'd be better to slip it in at the start of a
  development cycle not near the end.  (It should've gone into v10, really, but
  I forgot about it.) Discussion:
  https://postgr.es/m/CAMkU=1xHkyPa8VQgGcCNg3RMFFvVxUdOpus1gKcFuvVi0w6Acg@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/2b74303637edc09cf692fbfab3fd93a5e47ccabf

- Extend the default rules file for contrib/unaccent with Vietnamese letters.
  Improve generate unaccent rules.py to handle composed characters whose base is
  another composed character rather than a plain letter.  The net effect of this
  is to add a bunch of multi-accented Vietnamese characters to unaccent.rules.
  Original complaint from Kha Nguyen, diagnosis of the script's shortcoming by
  Thomas Munro.  Dang Minh Huong and Michael Paquier Discussion:
  https://postgr.es/m/CALo3sF6EC8cy1F2JUz=GRf5h4LMUJTaG3qpdoiLrNbWEXL-tRg@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/ec0a69e49bf41a37b5c2d6f6be66d8abae00ee05

- Add missing "static" marker.  Per pademelon.
  https://git.postgresql.org/pg/commitdiff/963af96920fabf5fd7ee28ecc96521f371c13a4b

- Further tweaks to compiler flags for PL/Perl on Windows.  It now emerges that
  we can only rely on Perl to tell us we must use -D USE 32BIT TIME T if it's
  Perl 5.13.4 or later.  For older versions, revert to our previous practice of
  assuming we need that symbol in all 32-bit Windows builds.  This is not ideal,
  but inquiring into which compiler version Perl was built with seems far too
  fragile.  In any case, we had not previously had complaints about these old
  Perl versions, so let's assume this is Good Enough.  (It's still better than
  the situation ante commit 5a5c2feca, in that at least the effects are confined
  to PL/Perl rather than the whole PG build.) Back-patch to all supported
  versions, like 5a5c2feca and predecessors.  Discussion:
  https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/b5178c5d08ca59e30f9d9428fa6fdb2741794e65

- Fix ExecReScanGatherMerge.  Not surprisingly, since it'd never ever been
  tested, ExecReScanGatherMerge didn't work.  Fix it, and add a regression test
  case to exercise it.  Amit Kapila Discussion:
  https://postgr.es/m/CAA4eK1JkByysFJNh9M349u nNjqETuEnY y1VUc kJiU0bxtaQ(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/a2b70c89ca1a5fcf6181d3c777d82e7b83d2de1b

- Temporarily revert test case from a2b70c89ca1a5fcf6181d3c777d82e7b83d2de1b.
  That code patch was good as far as it went, but the associated test case has
  exposed fundamental brain damage in the parallel scan mechanism, which is
  going to take nontrivial work to correct.  In the interests of getting the
  buildfarm back to green so that unrelated work can proceed, let's temporarily
  remove the test case.
  https://git.postgresql.org/pg/commitdiff/a20aac890a89e6f88e841dedbbfa8d9d5f7309fc

- Fix possible core dump in parallel restore when using a TOC list.  Commit
  3eb9a5e7c unintentionally introduced an ordering dependency into
  restore toc entries prefork().  The existing coding of reduce dependencies()
  contains a check to skip moving a TOC entry to the ready list if it wasn't
  initially in the pending list.  This used to suffice to prevent
  reduce dependencies() from trying to move anything into the ready list during
  restore toc entries prefork(), because the pending list stayed empty
  throughout that phase; but it no longer does.  The problem doesn't manifest
  unless the TOC has been reordered by SortTocFromFile, which is how I missed it
  in testing.  To fix, just add a test for ready list == NULL, converting the
  call with NULL from a poor man's sanity check into an explicit command not to
  touch TOC items' list membership.  Clarify some of the comments around this;
  in particular, note the primary purpose of the check for pending list
  membership, which is to ensure that we can't try to restore the same item
  twice, in case a TOC list forces it to be restored before its dependency count
  goes to zero.  Per report from Fabrízio de Royes Mello.  Back-patch to 9.3,
  like the previous commit.  Discussion:
  https://postgr.es/m/CAFcNs+pjuv0JL x4+=71TPUPjdLHOXA4YfT32myj OrrZb4ohA(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/b1c2d76a2fcef812af0be3343082414d401909c8

Peter Eisentraut pushed:

- doc: Fix logical replication protocol doc detail.  Author: Masahiko Sawada
  <sawada(dot)mshk(at)gmail(dot)com> Reported-by: Kyle Conroy <kyle(at)kyleconroy(dot)com> Bug:
  #14775
  https://git.postgresql.org/pg/commitdiff/79e5de690efce6e7aaa9c60e10389a8bc58c1617

- Fix typo.  Author: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
  https://git.postgresql.org/pg/commitdiff/7f1bb1d7346b67a62e8ec59f79f8284cb7fb4394

- doc: Improve PDF bookmarks.  Also create PDF bookmarks/ToC entries for
  subsections of reference pages.  This was a regression from the previous
  jadetex-based build.  Reported-by: Erik Rijkers <er(at)xs4all(dot)nl>
  https://git.postgresql.org/pg/commitdiff/270fec9f0bc9082ed99f0c447d450bd8cd92be73

- Simplify some code in logical replication launcher.  Avoid unnecessary locking
  calls when a subscription is disabled.  Author: Yugo Nagata
  <nagata(at)sraoss(dot)co(dot)jp>
  https://git.postgresql.org/pg/commitdiff/e42351ae07c19bb4eaedbdce8ccd4dfb4e905069

- doc: Add missing logical replication protocol message.  Author: Masahiko
  Sawada <sawada(dot)mshk(at)gmail(dot)com>
  https://git.postgresql.org/pg/commitdiff/34a23a34269519e19b5da3ea4e29e4e0abadfee3

- Fix logical replication protocol comparison logic.  Since we currently only
  have one protocol, this doesn't make much of a difference other than the error
  message.  Author: Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp>
  https://git.postgresql.org/pg/commitdiff/70b573b2677eb5ef28515e824e5027e26ce21d77

- psql: Add tab completion for \pset pager.  Author: Pavel Stehule
  <pavel(dot)stehule(at)gmail(dot)com>
  https://git.postgresql.org/pg/commitdiff/0f0ee68e94319e3f32baf3c18dcae1d5842b0d5c

- Include foreign tables in information schema.table privileges.  This appears
  to have been an omission in the original commit 0d692a0dc9f.  All related
  information schema views already include foreign tables.  Reported-by: Nicolas
  Thauvin <nicolas(dot)thauvin(at)dalibo(dot)com>
  https://git.postgresql.org/pg/commitdiff/0659465caa042b958e544e8b1857d8d7de03a83f

- doc: Document pg receivewal exit behavior and status.
  https://git.postgresql.org/pg/commitdiff/0a2d43d988eef2aee679582ba1b72b2587cbaab2

- Initialize replication slot catalog xmin in procarray.  Although not confirmed
  and probably rare, if the newly allocated memory is not already zero, this
  could possibly have caused some problems.  Also reorder the initializations
  slightly so they match the order of the struct definition.  Author: Wong, Yi
  Wen <yiwong(at)amazon(dot)com> Reviewed-by: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
  https://git.postgresql.org/pg/commitdiff/4d4c89171598424b31175ef9b600ac87a9a61023

- Fix up some misusage of appendStringInfo() and friends.  Change to
  appendStringInfoChar() or appendStringInfoString() where those can be used.
  Author: David Rowley <david(dot)rowley(at)2ndquadrant(dot)com> Reviewed-by: Ashutosh
  Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com>
  https://git.postgresql.org/pg/commitdiff/77d05706beb115b412728bd94dce16d83795583d

- pg receivewal: Improve verbose mode.  Some informational messages showed up
  even if verbose mode was not used.  Move them to verbose mode.  Author:
  Michael Paquier <michael(dot)paquier(at)gmail(dot)com> Reviewed-by: Daniel Gustafsson
  <daniel(at)yesql(dot)se>
  https://git.postgresql.org/pg/commitdiff/514731af58765f62b23309805270a07eae86c2c0

- Correct representation of foreign tables in information schema.
  tables.table type is supposed to be 'FOREIGN' rather than 'FOREIGN TABLE'
  according to the SQL standard.
  https://git.postgresql.org/pg/commitdiff/9b5140fb503eb50634cd7e080d41f4d9af41e0a6

- doc: Add logical replication to comparison matrix.  Author: Steve Singer
  <steve(at)ssinger(dot)info>
  https://git.postgresql.org/pg/commitdiff/346d5bf1ca33bcf27eda5d23fba3999e6356b905

- doc: Update URL of DocBook XSL stylesheets.  Author: Masahiko Sawada
  <sawada(dot)mshk(at)gmail(dot)com>
  https://git.postgresql.org/pg/commitdiff/4395f7daf3b40ecbd316bd2a68c253a56013a538

- pg dump: Support using synchronized snapshots on standbys.  This became
  possible by commit 6c2003f8a1bbc7c192a2e83ec51581c018aa162f.  This just makes
  pg dump aware of it and updates the documentation.  Author: Petr Jelinek
  <petr(dot)jelinek(at)2ndquadrant(dot)com>
  https://git.postgresql.org/pg/commitdiff/cf851519d40e85c8129515c06532515386eaf41c

- doc: Fix table column count.  Author: Erik Rijkers <er(at)xs4all(dot)nl>
  https://git.postgresql.org/pg/commitdiff/bfe089e3724ad8f9c8922165738d837b8641a6e6

- doc: Update RFC URLs.  Consistently use the IETF HTML links instead of a
  random mix of different sites and formats.  Correct one RFC number and fix one
  broken link.
  https://git.postgresql.org/pg/commitdiff/d54285935072175aac1c446e15ec778b08a8fd75

- Fix creation of ICU comments for keyword variants.  It would create the
  comment referring to the keyword-less parent locale.  This was broken in
  ddb5fdc068635d003a0d1c303cb109d1cb3ebeb1.
  https://git.postgresql.org/pg/commitdiff/24620fc52bd9d4139748591b6cce7327fd299684

Andres Freund pushed:

- Expand coverage of parallel gather merge a bit.  Previously paths reaching
  heap compare slots weren't covered.  Author: Rushabh Lathia Reviewed-By:
  Andres Freund Discussion:
  https://postgr.es/m/CAGPqQf3C+3PBujb+7m=ceWeii4-vBY=XS99LjzrpkpefvzJbFg@mail.gmail.com
  https://postgr.es/m/27200.1502482851@sss.pgh.pa.us Backpatch: 10, where gather
  merge was introduced
  https://git.postgresql.org/pg/commitdiff/d2bc501573d98ff5541271dca94fb5f7a004ecbf

- Partially flatten struct tupleDesc so that it can be used in DSM.  TupleDesc's
  attributes were already stored in contiguous memory after the struct.  Go one
  step further and get rid of the array of pointers to attributes so that they
  can be stored in shared memory mapped at different addresses in each backend.
  This won't work for TupleDescs with contraints and defaults, since those point
  to other objects, but for many purposes only attributes are needed.  Author:
  Thomas Munro Reviewed-By: Andres Freund Discussion:
  https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/c6293249dc178f52dd508c3e6ff353af41c90b58

- Change tupledesc->attrs[n] to TupleDescAttr(tupledesc, n).  This is a
  mechanical change in preparation for a later commit that will change the
  layout of TupleDesc.  Introducing a macro to abstract the details of where
  attributes are stored will allow us to change that in separate step and revise
  it in future.  Author: Thomas Munro, editorialized by Andres Freund
  Reviewed-By: Andres Freund Discussion:
  https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/2cd70845240087da205695baedab6412342d1dbe

Robert Haas pushed:

- pg dump: Add a --load-via-partition-root option.  Rushabh Lathia, reviewed and
  somewhat revised by me.  Testing by Rajkumar Raghuwanshi.  Discussion:
  http://postgr.es/m/CAGPqQf0C1he087bz9xRBOGZBuESYz9X=Fp8Ca g+TfHgAff75g(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/23d7680d04b958de327be96ffdde8f024140d50e

- Add missing call to ExecReScanGatherMerge.  Amit Kapila Discussion:
  http://postgr.es/m/CAA4eK1KeQWZOoDmDmGMwuqzPW9JhRS+ditQVFdAfGjNmMZzqMQ@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/1295a777882b8ed180a854e249f91be565a99422

- Avoid unnecessary single-child Append nodes.  Before commit
  d3cc37f1d801a6b5cad9bf179274a8, an inheritance parent whose only children were
  temp tables of other sessions would end up as a simple scan of the parent; but
  with that commit, we end up with an Append node, per a report from Ashutosh
  Bapat.  Tweak the logic so that we go back to the old way, and update the
  function header comment for partitioning while we're at it.  Ashutosh Bapat,
  reviewed by Amit Langote and adjusted by me.  Discussion:
  http://postgr.es/m/CAFjFpReWJr1yTkHU=OqiMBmcYCMoSW3VPR39RBuQ ovwDFBT5Q(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/d57929afc7063431f80a0ac4c510fc39aacd22e6

- Teach adjust appendrel attrs( multilevel) to do multiple translations.
  Currently, child relations are always base relations, so when we translate
  parent relids to child relids, we only need to translate a singler relid.
  However, the proposed partition-wise join feature will create child joins,
  which will mean we need to translate a set of parent relids to the
  corresponding child relids.  This is preliminary refactoring to make that
  possible.  Ashutosh Bapat.  Review and testing of the larger patch set of
  which this is a part by Amit Langote, Rajkumar Raghuwanshi, Rafia Sabih,
  Thomas Munro, Dilip Kumar, and me.  Some adjustments, mostly cosmetic, by me.
  Discussion:
  http://postgr.es/m/CA+TgmobQK80vtXjAsPZWWXd7c8u13G86gmuLupN+uUJjA+i4nA@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/480f1f4329f1bf8bfbbcda8ed233851e1b110ad4

- Assorted preparatory refactoring for partition-wise join.  Instead of
  duplicating the logic to search for a matching ParamPathInfo in multiple
  places, factor it out into a separate function.  Pass only the relevant bits
  of the PartitionKey to partition bounds equal instead of the whole thing,
  because partition-wise join will want to call this without having a
  PartitionKey available.  Adjust allow star schema join and
  calc nestloop required outer to take relevant Relids rather than the entire
  Path, because partition-wise join will want to call it with the top-parent
  relids to determine whether a child join is allowable.  Ashutosh Bapat.
  Review and testing of the larger patch set of which this is a part by Amit
  Langote, Rajkumar Raghuwanshi, Rafia Sabih, Thomas Munro, Dilip Kumar, and me.
  Discussion:
  http://postgr.es/m/CA+TgmobQK80vtXjAsPZWWXd7c8u13G86gmuLupN+uUJjA+i4nA@mail.gmail.com
  https://git.postgresql.org/pg/commitdiff/e139f1953f29db245f60a7acb72fccb1e05d2442

- Remove bogus line from comment.  Spotted by Tom Lane Discussion:
  http://postgr.es/m/27897.1502901074@sss.pgh.pa.us
  https://git.postgresql.org/pg/commitdiff/79f457e53ac37b5d383845c410e5a41457d74950

- Attempt to clarify comments related to force parallel mode.  Per discussion
  with Tom Lane.  Discussion: http://postgr.es/m/28589.1502902172@sss.pgh.pa.us
  https://git.postgresql.org/pg/commitdiff/1e56883a528eb623c9a55ec7e43b4eee3722014b

- Refactor validation of new partitions a little bit.  Move some logic that is
  currently in ATExecAttachPartition to separate functions to facilitate future
  code reuse.  Ashutosh Bapat and Jeevan Ladhe Discussion:
  http://postgr.es/m/CA+Tgmobbnamyvii0pRdg9pp jLHSUvq7u5SiRrVV0tEFFU58Tg(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/ecfe59e50fb8316ab7fc653419cd724c8b7a7dd7

- Don't lock tables in RelationGetPartitionDispatchInfo.  Instead, lock them in
  the caller using find all inheritors so that they get locked in the standard
  order, minimizing deadlock risks.  Also in RelationGetPartitionDispatchInfo,
  avoid opening tables which are not partitioned; there's no need.  Amit
  Langote, reviewed by Ashutosh Bapat and Amit Khandekar Discussion:
  http://postgr.es/m/91b36fa1-c197-b72f-ca6e-56c593bae68c@lab.ntt.co.jp
  https://git.postgresql.org/pg/commitdiff/54cde0c4c05807321d3f4bf96a97c376e3fa91cb

- Fix interaction of triggers, partitioning, and EXPLAIN ANALYZE.  Add a new
  EState member es leaf result relations, so that the trigger code knows about
  ResultRelInfos created by tuple routing.  Also make sure ExplainPrintTriggers
  knows about partition-related ResultRelInfos.  Etsuro Fujita, reviewed by Amit
  Langote Discussion:
  http://postgr.es/m/57163e18-8e56-da83-337a-22f2c0008051@lab.ntt.co.jp
  https://git.postgresql.org/pg/commitdiff/c4b841ba6aa9252ab9dacd59d317aba8cfa9b31a

Álvaro Herrera pushed:

- Fix error handling path in autovacuum launcher.  The original code (since
  00e6a16d01) was assuming aborting the transaction in autovacuum launcher was
  sufficient to release all resources, but in reality the launcher runs quite a
  lot of code out of any transactions.  Re-introduce individual cleanup calls to
  make abort more robust.  Reported-by: Robert Haas Discussion:
  https://postgr.es/m/CA+TgmobQVbz4K +RSmiM9HeRKpy3vS5xnbkL95gSEnWijzprKQ(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/d9a622cee162775ae42aa5c1ac592760d0d777d9

- Simplify autovacuum work-item implementation.  The initial implementation of
  autovacuum work-items used a dynamic shared memory area (DSA).  However, it's
  argued that dynamic shared memory is not portable enough, so we cannot rely on
  it being supported everywhere; at the same time, autovacuum work-items are now
  a critical part of the server, so it's not acceptable that they don't work in
  the cases where dynamic shared memory is disabled.  Therefore, let's fall back
  to a simpler implementation of work-items that just uses autovacuum's main
  shared memory segment for storage.  Discussion:
  https://postgr.es/m/CA+TgmobQVbz4K +RSmiM9HeRKpy3vS5xnbkL95gSEnWijzprKQ(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/31ae1638ce35c23979f9bcbb92c6bb51744dbccb

Heikki Linnakangas pushed:

- Use atomic ops to hand out pages to scan in parallel scan.  With a lot of
  CPUs, the spinlock that protects the current scan location in a parallel scan
  can become a bottleneck. Use an atomic fetch-and-add instruction instead.
  David Rowley Discussion:
  https://www.postgresql.org/message-id/CAKJS1f9tgsPhqBcoPjv9 KUPZvTLCZ4jy%3DB%3DbhqgaKn7cYzm-w(at)mail(dot)gmail(dot)com
  https://git.postgresql.org/pg/commitdiff/3cda10f41bfed7e34b0db7013b66dd40a5f75926

- Remove dedicated B-tree root-split record types.  Since commit 40dae7ec53,
  which changed the way b-tree page splitting works, there has been no
  difference in the handling of root, and non-root split WAL records. We don't
  need to distinguish them anymore If you're worried about the loss of debugging
  information, note that usually a root split record will normally be followed
  by a WAL record to create the new root page. The root page will also have the
  BTP ROOT flag set on the page itself, and there is a pointer to it from the
  metapage.  Author: Aleksander Alekseev Discussion:
  https://www.postgresql.org/message-id/20170406122116.GA11081@e733.localdomain
  https://git.postgresql.org/pg/commitdiff/0c504a80cf2e6f66df2cdea563e879bf4abd1629

- Fix shm toc.c to always return buffer-aligned memory.  Previously, if you
  passed a non-aligned size to shm toc create(), the memory returned by
  shm toc allocate() would be similarly non-aligned.  This was exposed by commit
  3cda10f41b, which allocated structs containing a pg atomic uint64 field with
  shm toc allocate(). On systems with MAXIMUM ALIGNOF = 4, such structs still
  need to be 8-bytes aligned, but the memory returned by shm toc allocate() was
  only 4-bytes aligned.  It's quite bogus that we abuse BUFFERALIGN to align the
  structs for pg atomic uint64. It doesn't really have anything to do with
  buffers. But that's a separate issue.  This ought to fix the buildfarm
  failures on 32-bit x86 systems.  Discussion:
  https://www.postgresql.org/message-id/7e0a73a5-0df9-1859-b8ae-9acf122dc38d@iki.fi
  https://git.postgresql.org/pg/commitdiff/ac883ac453e9c479f397780918f235c440b7a02f

- Fix pg atomic u64 initialization.  As Andres pointed out, pg atomic init u64
  must be used to initialize an atomic variable, before it can be accessed with
  the actual atomic ops.  Trying to use pg atomic write u64 on an uninitialized
  variable leads to a failure with the fallback implementation that uses a
  spinlock.  Discussion:
  https://www.postgresql.org/message-id/20170816191346.d3ke5tpshhco4bnd%40alap3.anarazel.de
  https://git.postgresql.org/pg/commitdiff/dcd052c8d20c5359c55f2a101f10a8e6341233cd

== Pending Patches ==

Amit Kapila sent in another revision of a patch to parallelize queries
containing initplans.

Michaël Paquier sent in a patch to simplify ACL handling for large objects and
removal of superuser() checks.

Mark Rofail sent in two more revisions of a patch to implement foreign key
arrays.

Masahiko Sawada sent in another revision of a patch to implement block level
parallel vacuum.

Fabien COELHO sent in another revision of a patch to add more functions and
operators to pgbench.

Marko Tiikkaja sent in a patch to implement INSERT .. ON CONFLICT DO SELECT [FOR ..]

Masahiko Sawada sent in a patch to enable logging the explicit relation name in
VACUUM VERBOSE logs.

Álvaro Herrera sent in a patch to release lwlocks in autovacuum launcher error
handling path.

Peter Eisentraut sent in a patch to document TR 35 collation options for ICU.

Tom Lane and Robert Haas traded commnet patches to clarify force parallel.

Robert Haas sent in two more revisions of a patch to implement auto prewarm.

Etsuro Fujita sent in a patch to ensure that stats for triggers on partitioned
tables are shown in EXPLAIN ANALYZE.

Nathan Bossart sent in another revision of a patch to allow users to specify
multiple tables in VACUUM commands.

Tobias Bussmann sent in a patch to make \gx does work when \set FETCH COUNT n is
done.

Thomas Munro sent in two more revisions of a patch to enable sharing record
typmods among backends.

Masahiko Sawada sent in another revision of a patch to move extension locks out
of the heavyweight lock manager.

Masahiko Sawada sent in another revision of a patch to pgbench to allow skipping
creating primary keys after initialization.

Konstantin Knizhnik sent in a patch to do some secondary index access
optimizations.

Pavel Stěhule sent in another revision of a patch to check the PSQL_PAGER
environment variable in psql.

Pavel Stěhule sent in another revision of a patch to allow sorting describe (\d)
commands in psql.

Heikki Linnakangas sent in a patch to fix shm_toc alignment.

Peter Eisentraut sent in a patch to to use stdbool.h.

Ildus Kurbangaliev sent in another revision of a patch to remove the 1MB size
limit in tsvector.

Robert Haas sent in two revisions of a patch to allow hash functions to have a
second, optional support function.

Adrien NAYRAT sent in a patch to fix the docs for the multivariate histograms
and MCV lists patch.

Beena Emerson sent in two more revisions of a patch to enable default partitions
for declarative range partitions.

Oliver Ford sent in two more revisions of a patch to fix number skipping in
to_number.

Antonin Houska sent in another revision of a patch to implement aggregate
pushdown.

Peter Eisentraut sent in a patch to do some assorted cleanup including removing
some dead code from contrib/fuzzystrmatch, our own definition of NULL,
unnecessary parentheses in return statements, unnecessary casts in contrib/cube,
and the endof macro, and dropping  excessive dereferencing of function pointers.

Etsuro Fujita sent in another revision of a patch to fix a postgres_fdw bug.

Dilip Kumar sent in another revision of a patch to improve bitmap costing for
lossy pages.

Masahiko Sawada sent in another revision of a patch to improve messaging during
logical replication worker startup, split the SetSubscriptionRelState function
into two, allow syscache access to subscriptions in database-less processes, and
improve locking for subscriptions and subscribed relations.

Jeevan Ladhe sent in another revision of a patch to add support for default
partition in declarative partitioning.

Masahiko Sawada sent in a patch to add a documentation warning about FIRST.

Konstantin Knizhnik and Douglas Doole traded patches to enable passing LIMIT to
a FDW.

Daniel Gustafsson sent in another revision of a patch to allow running SSL tests
against different binaries, add support for Apple Secure Transport SSL library,
document Secure Transport, and fix SSL tests for connstrings with spaces.

David Steele sent in two revisions of a patch to update the low-level backup
documentation to match actual behavior.

Vinayak Pokale sent in a patch to add WHENEVER statement DO CONTINUE support for
ECPG.

Michael Banck sent in a patch to add an option to create a replication slot in
pg_basebackup if not yet present.

Thomas Munro sent in another revision of a patch to implement parallel hashing.

Vesa-Matti J Kari sent in a patch to add HISTIGNORE for psql.

Simon Riggs sent in a patch to exclude special values in recovery target
time.v1.patch.

Pavel Stěhule sent in four more revisions of a patch to fix some possible
encoding issues with libxml2 functions.

Fabien COELHO sent in another revision of a patch to add pgbench TAP tests.



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