== PostgreSQL Weekly News - December 10 2017 ==

== PostgreSQL Weekly News - December 10 2017 ==

The CFP for PGCon 2018 in Ottawa is open until January 19, 2018.
https://www.pgcon.org/2018/papers.php

== PostgreSQL Product News ==

OmniDB 2.4, a browser-based database management tool, released.
https://www.2ndquadrant.com/en/resources/omnidb/

check_pgactivity 2.3, a Nagios remote agent for monitoring PostgreSQL, released.
https://github.com/OPMDG/check_pgactivity/releases

PostgreSQL PHP Generator Lite released.
http://www.sqlmaestro.com/products/postgresql/phpgenerator/

pitrery 2.0, a set of Bash scripts to manage PITR backups for PostgreSQL, released.
https://github.com/dalibo/pitrery

== PostgreSQL Jobs for December ==

http://archives.postgresql.org/pgsql-jobs/2017-12/

== PostgreSQL Local ==

FOSDEM PGDay 2018, a one day conference held before the main FOSDEM event will
be held in Brussels, Belgium, on Feb 2nd, 2018.
https://2018.fosdempgday.org/

Prague PostgreSQL Developer Day 2018 (P2D2 2018) is a two-day
conference that will be held on February 14-15 2018 in Prague, Czech Republic.
The CfP is open until January 5, 2018 at https://p2d2.cz/callforpapers
http://www.p2d2.cz/

PGConf India 2018 will be on February 22-23, 2018 in Bengaluru, Karnataka.
http://pgconf.in/

PostgreSQL(at)SCaLE is a two day, two track event which takes place on
March 8-9, 2018, at Pasadena Convention Center, as part of SCaLE 16X.
http://www.socallinuxexpo.org/scale/16x/cfp

Nordic PGDay 2018 will be held in Oslo, Norway, at the Radisson Blu Hotel
Nydalen, on March 13, 2018. The CfP is open through December 31, 2017 at
https://2018.nordicpgday.org/cfp/

pgDay Paris 2018 will be held in Paris, France at the Espace Saint-Martin, on
March 15 2018. The CfP is open until December 31, 2017.
http://2018.pgday.paris/callforpapers/

PGConf APAC 2018 will be held in Singapore March 22-24, 2018.
http://2018.pgconfapac.org/

The German-speaking PostgreSQL Conference 2018 will take place on April 13th,
2018 in Berlin. The CfP is open until January 09, 2018 at
http://2018.pgconf.de/de/callforpapers.html and the conference site is at
http://2018.pgconf.de/

PGCon 2018 will take place in Ottawa on May 29 - June 1, 2018. The CFP is open
until January 19, 2018 at https://www.pgcon.org/2018/papers.php
https://www.pgcon.org/2018/

PGConf.Brazil 2018 will take place in São Paulo, Brazil on August 3-4 2018. The
CfP will open soon.
http://pgconf.com.br

== 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 EST5EDT. 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 ==

Robert Haas pushed:

- Remove memory leak protection from Gather and Gather Merge nodes. Before
commit 6b65a7fe62e129d5c2b85cd74d6a91d8f7564608, tqueue.c could perform tuple
remapping and thus leak memory, which is why commit
af33039317ddc4a0e38a02e2255c2bf453115fd2 made TupleQueueReaderNext run in a
short-lived context. Now, however, tqueue.c has been reduced to a shadow of
its former self, and there shouldn't be any chance of leaks any more.
Accordingly, remove some tuple copying and memory context manipulation to
speed up processing. Patch by me, reviewed by Amit Kapila. Some testing by
Rafia Sabih. Discussion:
http://postgr.es/m/CAA4eK1LSDydwrNjmYSNkfJ3ZivGSWH9SVswh6QpNzsMdj_oOQA@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/9f4992e2a9939a4c3d560c2ac58067861ee0029a

- Mark assorted variables PGDLLIMPORT. This makes life easier for extension
authors who wish to support Windows. Brian Cloutier, slightly amended by me.
Discussion:
http://postgr.es/m/CAJCy68fscdNhmzFPS4kyO00CADkvXvEa-28H-OtENk-pa2OTWw@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/c572599c65bfe0387563233faabecd2845073538

- postgres_fdw: Fix failing regression test. Commit
ab3f008a2dc364cf7fb75de0a691fb0c61586c8e broke this. Report by Stephen Frost.
Discussion: http://postgr.es/m/20171205180342.GO4628@tamriel.snowman.net
https://git.postgresql.org/pg/commitdiff/82c5c533d1f55dfbf3eacc61aff64fedc8915d78

- postgres_fdw: Judge password use by run-as user, not session user. This is a
backward incompatibility which should be noted in the release notes for
PostgreSQL 11. For security reasons, we require that a postgres_fdw foreign
table use password authentication when accessing a remote server, so that an
unprivileged user cannot usurp the server's credentials. Superusers are
exempt from this requirement, because we assume they are entitled to usurp the
server's credentials or, at least, can find some other way to do it. But what
should happen when the foreign table is accessed by a view owned by a user
different from the session user? Is it the view owner that must be a
superuser in order to avoid the requirement of using a password, or the
session user? Historically it was the latter, but this requirement makes it
the former instead. This allows superusers to delegate to other users the
right to select from a foreign table that doesn't use password authentication
by creating a view over the foreign table and handing out rights to the view.
It is also more consistent with the idea that access to a view should use the
view owner's privileges rather than the session user's privileges. The upshot
of this change is that a superuser selecting from a view created by a
non-superuser may now get an error complaining that no password was used,
while a non-superuser selecting from a view created by a superuser will no
longer receive such an error. No documentation changes are present in this
patch because the wording of the documentation already suggests that it works
this way. We should perhaps adjust the documentation in the back-branches,
but that's a task for another patch. Originally proposed by Jeff Janes, but
with different semantics; adjusted to work like this by me per discussion.
Discussion:
http://postgr.es/m/CA+TgmoaY4HsVZJv5SqEjCKLDwtCTSwXzKpRftgj50wmMMBwciA@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/ab3f008a2dc364cf7fb75de0a691fb0c61586c8e

- Fix accumulation of parallel worker instrumentation. When a Gather or Gather
Merge node is started and stopped multiple times, the old code wouldn't reset
the shared state between executions, potentially resulting in dramatically
inflated instrumentation data for nodes beneath it. (The per-worker
instrumentation ended up OK, I think, but the overall totals were inflated.)
Report by hubert depesz lubaczewski. Analysis and fix by Amit Kapila,
reviewed and tweaked a bit by me. Discussion:
http://postgr.es/m/20171127175631.GA405@depesz.com
https://git.postgresql.org/pg/commitdiff/2c09a5c12a66087218c7f8cba269cd3de51b9b82

- Fix Parallel Append crash. Reported by Tom Lane and the buildfarm. Amul Sul
and Amit Khandekar Discussion:
http://postgr.es/m/17868.1512519318@sss.pgh.pa.us Discussion:
http://postgr.es/m/CAJ3gD9cJQ4d-XhmZ6BqM9rMM2KDBfpkdgOAb4+psz56uBuMQ_A@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/9c64ddd414855fb10e0355e887745270a4464c50

- Report failure to start a background worker. When a worker is flagged as
BGW_NEVER_RESTART and we fail to start it, or if it is not marked
BGW_NEVER_RESTART but is terminated before startup succeeds, what
BgwHandleStatus should be reported? The previous code really hadn't
considered this possibility (as indicated by the comments which ignore it
completely) and would typically return BGWH_NOT_YET_STARTED, but that's not a
good answer, because then there's no way for code using
GetBackgroundWorkerPid() to tell the difference between a worker that has not
started but will start later and a worker that has not started and will never
be started. So, when this case happens, return BGWH_STOPPED instead. Update
the comments to reflect this. The preceding fix by itself is insufficient to
fix the problem, because the old code also didn't send a notification to the
process identified in bgw_notify_pid when startup failed. That might've been
technically correct under the theory that the status of the worker was
BGWH_NOT_YET_STARTED, because the status would indeed not change when the
worker failed to start, but now that we're more usefully reporting
BGWH_STOPPED, a notification is needed. Without these fixes, code which
starts background workers and then uses the recommended APIs to wait for those
background workers to start would hang indefinitely if the postmaster failed
to fork a worker. Amit Kapila and Robert Haas Discussion:
http://postgr.es/m/CAA4eK1KDfKkvrjxsKJi3WPyceVi3dH1VCkbTJji2fuwKuB=3uw@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/28724fd90d2f85a0573a8107b48abad062a86d83

- When VACUUM or ANALYZE skips a concurrently dropped table, log it. Hopefully,
the additional logging will help avoid confusion that could otherwise result.
Nathan Bossart, reviewed by Michael Paquier, Fabrízio Mello, and me
https://git.postgresql.org/pg/commitdiff/ab6eaee88420db58a948849d5a735997728d73a9

- Support Parallel Append plan nodes. When we create an Append node, we can
spread out the workers over the subplans instead of piling on to each subplan
one at a time, which should typically be a bit more efficient, both because
the startup cost of any plan executed entirely by one worker is paid only once
and also because of reduced contention. We can also construct Append plans
using a mix of partial and non-partial subplans, which may allow for
parallelism in places that otherwise couldn't support it. Unfortunately, this
patch doesn't handle the important case of parallelizing UNION ALL by running
each branch in a separate worker; the executor infrastructure is added here,
but more planner work is needed. Amit Khandekar, Robert Haas, Amul Sul,
reviewed and tested by Ashutosh Bapat, Amit Langote, Rafia Sabih, Amit Kapila,
and Rajkumar Raghuwanshi. Discussion:
http://postgr.es/m/CAJ3gD9dy0K_E8r727heqXoBmWZ83HwLFwdcaSSmBQ1+S+vRuUQ@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/ab72716778128fb63d54ac256adf7fe6820a1185

- Speed up isolation test for concurrent VACUUM/ANALYZE behavior. Per Tom Lane,
the old test sometimes times out with CLOBBER_CACHE_ALWAYS. Nathan Bossart
Discussion: http://postgr.es/m/28614.1512583046@sss.pgh.pa.us
https://git.postgresql.org/pg/commitdiff/0a3edbb3302173f8ac465570b6273392aa6e20b1

Tom Lane pushed:

- Support boolean columns in functional-dependency statistics. There's no good
reason that the multicolumn stats stuff shouldn't work on booleans. But it
looked only for "Var = pseudoconstant" clauses, and it will seldom find those
for boolean Vars, since earlier phases of planning will fold "boolvar = true"
or "boolvar = false" to just "boolvar" or "NOT boolvar" respectively. Improve
dependencies_clauselist_selectivity() to recognize such clauses as equivalent
to equality restrictions. This fixes a failure of the extended stats
mechanism to apply in a case reported by Vitaliy Garnashevich. It's not a
complete solution to his problem because the bitmap-scan costing code isn't
consulting extended stats where it should, but that's surely an independent
issue. In passing, improve some comments, get rid of a NumRelids() test
that's redundant with the preceding bms_membership() test, and fix
dependencies_clauselist_selectivity() so that estimatedclauses actually is a
pure output argument as stated by its API contract. Back-patch to v10 where
this code was introduced. Discussion:
https://postgr.es/m/73a4936d-2814-dc08-ed0c-978f76f435b0@gmail.com
https://git.postgresql.org/pg/commitdiff/ecc27d55f4c37a8485a7d0e1dae0eb5ef2bc886e

- Clean up assorted messiness around AllocateDir() usage. This patch fixes a
couple of low-probability bugs that could lead to reporting an irrelevant
errno value (and hence possibly a wrong SQLSTATE) concerning directory-open or
file-open failures. It also fixes places where we took shortcuts in reporting
such errors, either by using elog instead of ereport or by using ereport but
forgetting to specify an errcode. And it eliminates a lot of just plain
redundant error-handling code. In service of all this, export fd.c's
formerly-static function ReadDirExtended, so that external callers can make
use of the coding pattern dir = AllocateDir(path); while ((de =
ReadDirExtended(dir, path, LOG)) != NULL) if they'd like to treat
directory-open failures as mere LOG conditions rather than errors. Also fix
FreeDir to be a no-op if we reach it with dir == NULL, as such a coding
pattern would cause. Then, remove code at many call sites that was throwing
an error or log message for AllocateDir failure, as ReadDir or ReadDirExtended
can handle that job just fine. Aside from being a net code savings, this gets
rid of a lot of not-quite-up-to-snuff reports, as mentioned above. (In some
places these changes result in replacing a custom error message such as "could
not open tablespace directory" with more generic wording "could not open
directory", but it was agreed that the custom wording buys little as long as
we report the directory name.) In some other call sites where we can't just
remove code, change the error reports to be fully project-style-compliant.
Also reorder code in restoreTwoPhaseData that was acquiring a lock between
AllocateDir and ReadDir; in the unlikely but surely not impossible case that
LWLockAcquire changes errno, AllocateDir failures would be misreported. There
is no great value in opening the directory before acquiring TwoPhaseStateLock,
so just do it in the other order. Also fix CheckXLogRemoved to guarantee that
it preserves errno, as quite a number of call sites are implicitly assuming.
(Again, it's unlikely but I think not impossible that errno could change
during a SpinLockAcquire. If so, this function was broken for its own
purposes as well as breaking callers.) And change a few places that were using
not-per-project-style messages, such as "could not read directory" when "could
not open directory" is more correct. Back-patch the exporting of
ReadDirExtended, in case we have occasion to back-patch some fix that makes
use of it; it's not needed right now but surely making it global is pretty
harmless. Also back-patch the restoreTwoPhaseData and CheckXLogRemoved fixes.
The rest of this is essentially cosmetic and need not get back-patched.
Michael Paquier, with a bit of additional work by me Discussion:
https://postgr.es/m/CAB7nPqRpOCxjiirHmebEFhXVTK7V5Jvw4bz82p7Oimtsm3TyZA@mail.gmail.com
https://git.postgresql.org/pg/commitdiff/2069e6faa0f72eba968714b2260cd65436d0ef3a

- Improve error handling in RemovePgTempFiles(). Modify this function and its
subsidiaries so that syscall failures are reported via ereport(LOG), rather
than silently ignored as before. We don't want to throw a hard ERROR, as that
would prevent database startup, and getting rid of leftover temporary files is
not important enough for that. On the other hand, not reporting trouble at
all seems like an odd choice not in line with current project norms,
especially since any failure here is quite unexpected. On the same reasoning,
adjust these functions' AllocateDir/ReadDir calls so that failure to scan a
directory results in LOG not ERROR. I also removed the previous practice of
silently ignoring ENOENT failures during directory opens --- there are some
corner cases where that could happen given a previous database crash, but that
seems like a bad excuse for ignoring a condition that isn't expected in most
cases. A LOG message during postmaster start seems OK in such situations, and
better than no output at all. In passing, make RemovePgTempRelationFiles'
test for "is the file name all digits" look more like the way it's done
elsewhere. Discussion: https://postgr.es/m/19907.1512402254@sss.pgh.pa.us
https://git.postgresql.org/pg/commitdiff/561885db05d3296082ce8750805b8ec322cf9aa1

- Simplify do_pg_start_backup's API by opening pg_tblspc internally.
do_pg_start_backup() expects its callers to pass in an open DIR pointer for
the pg_tblspc directory, but there's no apparent advantage in that. It
complicates the callers without adding any flexibility, and there's no
robustness advantage, since we surely have to be prepared for errors during
the scan of pg_tblspc anyway. In fact, by holding an extra kernel resource
during operations like the preliminary checkpoint, we might be making things a
fraction more failure-prone not less. Hence, remove that argument and open
the directory just for the duration of the actual scan. Discussion:
https://postgr.es/m/28752.1512413887@sss.pgh.pa.us
https://git.postgresql.org/pg/commitdiff/066bc21c0e085e2642ff25cc665c4efad3669d6f

- Treat directory open failures as hard errors in ResetUnloggedRelations().
Previously, this code just reported such problems at LOG level and kept going.
The problem with this approach is that transient failures (e.g., ENFILE) could
prevent us from resetting unlogged relations to empty, yet allow recovery to
appear to complete successfully. That seems like a data corruption hazard
large enough to treat such problems as reasons to fail startup. For the same
reason, treat unlink failures for unlogged files as hard errors not just LOG
messages. It's a little odd that we did it like that when file-level errors
in other steps (copy_file, fsync_fname) are ERRORs. The sole case that I left
alone is that ENOENT failure on a tablespace (not database) directory is not
an error, though it will now be logged rather than just silently ignored.
This is to cover the scenario where a previous DROP TABLESPACE removed the
tablespace directory but failed before removing the pg_tblspc symlink. I'm
not sure that that's very likely in practice, but that seems like the only
real excuse for the old behavior here, so let's allow for it. (As coded, this
will also allow ENOENT on $PGDATA/base/. But since we'll fail soon enough if
that's gone, I don't think we need to complicate this code by distinguishing
that from a true tablespace case.) Discussion:
https://postgr.es/m/21040.1512418508@sss.pgh.pa.us
https://git.postgresql.org/pg/commitdiff/8dc3c971a9d6db5ddc9f0a3c11a70308412d66c3

- Fix broken markup.
https://git.postgresql.org/pg/commitdiff/7404704a0c5abf0510a9cd889bd867ce46bdfc4c

- Adjust regression test cases added by commit ab7271677. I suppose it is a
copy-and-paste error that this test doesn't actually test the "Parallel Append
with both partial and non-partial subplans" case (EXPLAIN alone surely doesn't
qualify as a test of executor behavior). Fix that. Also, add cosmetic
aliases to make it possible to tell apart these otherwise-identical test cases
in log_statement output.
https://git.postgresql.org/pg/commitdiff/979a36c3894db0a4b0d6b4b20fc861a0bbe3271c

- In plpgsql, unify duplicate variables for record and row cases. plpgsql's
function exec_move_row() handles assignment of a composite source value to
either a PLpgSQL_rec or PLpgSQL_row target variable. Oddly, rather than
taking a single target argument which it could do run-time type detection on,
it was coded to take two separate arguments (only one of which is allowed to
be non-NULL). This choice had then back-propagated into storing two separate
target variables in various plpgsql statement nodes, with lots of duplicative
coding and awkward interface logic to support that. Simplify matters by
folding those pairs down to single variables, distinguishing the two cases
only where we must ... which turns out to be only in exec_move_row itself.
This is purely refactoring and should not change any behavior. In passing,
remove unused field PLpgSQL_stmt_open.returntype. Discussion:
https://postgr.es/m/11787.1512713374@sss.pgh.pa.us
https://git.postgresql.org/pg/commitdiff/dd759b96ea8fa41b48541dd321c07d9a947f8de9

- Fix plpgsql to reinitialize record variables at block re-entry. If one exits
and re-enters a DECLARE ... BEGIN ... END block within a single execution of a
plpgsql function, perhaps due to a surrounding loop, the declared variables
are supposed to get re-initialized to null (or whatever their initializer is).
But this failed to happen for variables of type "record", because while
exec_stmt_block() expected such variables to be included in the block's
initvarnos list, plpgsql_add_initdatums() only adds DTYPE_VAR variables to
that list. This bug appears to have been there since the aboriginal addition
of plpgsql to our tree. Fix by teaching plpgsql_add_initdatums() to include
DTYPE_REC variables as well. (We don't need to consider other DTYPEs because
they don't represent separately-stored values.) I failed to resist the
temptation to make some nearby cosmetic adjustments, too. No back-patch,
because there have not been field complaints, and it seems possible that
somewhere out there someone has code depending on the incorrect behavior. In
any case this change would have no impact on correctly-written code.
Discussion: https://postgr.es/m/22994.1512800671@sss.pgh.pa.us
https://git.postgresql.org/pg/commitdiff/390d58135b22bc25229b524a60f69682182201d8

Peter Eisentraut pushed:

- Fix warnings from cpluspluscheck. Fix warnings about "comparison between
signed and unsigned integer expressions" in inline functions in header files
by adding some casts.
https://git.postgresql.org/pg/commitdiff/e7cfb26fbc11ea94e93e443e2260e106b6daabdd

- doc: Turn on generate.consistent.ids parameter. This ensures that
automatically generated HTML anchors don't change in every build.
https://git.postgresql.org/pg/commitdiff/28f8896af0765a05447f605c55fa9f1ab3b41150

- doc: Update memory requirements for FOP. Reported-by: Dave Page
<dpage(at)pgadmin(dot)org>
https://git.postgresql.org/pg/commitdiff/8097d189ccc2cd55a8bf189bd21cb196e3cfc385

- doc: Flex is not a GNU package. Remove the designation that Flex is a GNU
package. Even though Bison is a GNU package, leave out the designation to not
make the sentence unnecessarily complicated. Author: Pavan Maddamsetti
<pavan(dot)maddamsetti(at)gmail(dot)com>
https://git.postgresql.org/pg/commitdiff/51cff91c905e3b32c1f9b56d82d5c802b257b157

- Apply identity sequence values on COPY. A COPY into a table should apply
identity sequence values just like it does for ordinary defaults. This was
previously forgotten, leading to null values being inserted, which in turn
would fail because identity columns have not-null constraints. Author:
Michael Paquier <michael(dot)paquier(at)gmail(dot)com> Reported-by: Steven Winfield
<steven(dot)winfield(at)cantabcapital(dot)com> Bug: #14952
https://git.postgresql.org/pg/commitdiff/2d2d06b7e27e3177d5bef0061801c75946871db3

- Fix mistake in comment. Reported-by: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
https://git.postgresql.org/pg/commitdiff/af9f8b7ca343eefa33b693d7919d8f945aeee3e7

- Prohibit identity columns on typed tables and partitions. Those cases
currently crash and supporting them is more work then originally thought, so
we'll just prohibit these scenarios for now. Author: Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> Reviewed-by: Amit Langote
<Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> Reported-by: Мансур Галиев <gomer94(at)yandex(dot)ru>
Bug: #14866
https://git.postgresql.org/pg/commitdiff/005ac298b1bdc3e9bd19e5ee2bcf7e320ebe4130

Andres Freund pushed:

- Fix EXPLAIN ANALYZE of hash join when the leader doesn't participate. If a
hash join appears in a parallel query, there may be no hash table available
for explain.c to inspect even though a hash table may have been built in other
processes. This could happen either because parallel_leader_participation was
set to off or because the leader happened to hit the end of the outer relation
immediately (even though the complete relation is not empty) and decided not
to build the hash table. Commit bf11e7ee introduced a way for workers to
exchange instrumentation via the DSM segment for Sort nodes even though they
are not parallel-aware. This commit does the same for Hash nodes, so that
explain.c has a way to find instrumentation data from an arbitrary participant
that actually built the hash table. Author: Thomas Munro Reviewed-By: Andres
Freund Discussion:
https://postgr.es/m/CAEepm%3D3DUQC2-z252N55eOcZBer6DPdM%3DFzrxH9dZc5vYLsjaA%40mail.gmail.com
https://git.postgresql.org/pg/commitdiff/5bcf389ecfd40daf92238e1abbff4fc4d3f18b33

Noah Misch pushed:

- MSVC: Test whether 32-bit Perl needs -D_USE_32BIT_TIME_T. Commits
5a5c2feca3fd858e70ea348822595547e6fa6c15 and
b5178c5d08ca59e30f9d9428fa6fdb2741794e65 introduced support for modern
MSVC-built, 32-bit Perl, but they broke use of MinGW-built, 32-bit Perl
distributions like Strawberry Perl and modern ActivePerl. Perl has no robust
means to report whether it expects a -D_USE_32BIT_TIME_T ABI, so test this.
Back-patch to 9.3 (all supported versions). The chief alternative was a
heuristic of adding -D_USE_32BIT_TIME_T when $Config{gccversion} is nonempty.
That banks on every gcc-built Perl using the same ABI. gcc could change its
default ABI the way MSVC once did, and one could build Perl with gcc and the
non-default ABI. The GNU make build system could benefit from a similar test,
without which it does not support MSVC-built Perl. For now, just add a
comment. Most users taking the special step of building Perl with MSVC
probably build PostgreSQL with MSVC. Discussion:
https://postgr.es/m/20171130041441.GA3161526@rfd.leadboat.com
https://git.postgresql.org/pg/commitdiff/65a00f30352a3c0ab5615fac008735b103cfa5bb

- MSVC 2012+: Permit linking to 32-bit, MinGW-built libraries. Notably, this
permits linking to the 32-bit Perl binaries advertised on perl.org, namely
Strawberry Perl and ActivePerl. This has a side effect of permitting linking
to binaries built with obsolete MSVC versions. By default, MSVC 2012 and
later require a "safe exception handler table" in each binary. MinGW-built,
32-bit DLLs lack the relevant exception handler metadata, so linking to them
failed with error LNK2026. Restore the semantics of MSVC 2010, which omits
the table from a given binary if some linker input lacks metadata. This has
no effect on 64-bit builds or on MSVC 2010 and earlier. Back-patch to 9.3
(all supported versions). Reported by Victor Wagner. Discussion:
https://postgr.es/m/20160326154321.7754ab8f@wagner.wagner.home
https://git.postgresql.org/pg/commitdiff/7e0c574ee26ce0308b76166312788e909b555c23

Magnus Hagander pushed:

- Fix typo. Reported by Robins Tharakan
https://git.postgresql.org/pg/commitdiff/d8f632caec3fcc5eece9d53d7510322f11489fe4

- Fix regression test output. Missed this in the last commit.
https://git.postgresql.org/pg/commitdiff/ce1468d02bdbbe3aa710463fa9faaf8cf865ad72

== Pending Patches ==

Yura Sokolov sent in another revision of a patch to improve compactify_tuples.

Dmitry Dolgov sent in another revision of a patch to implement generic type
subscripting.

Jing Wang sent in another revision of a patch to implement COMMENT ON DATABASE
CURRENT_DATABASE.

John Naylor sent in a patch to make bootstrap data simpler and faster.

Sergei Kornilov sent in another revision of a patch to implement ALTER TABLE ...
SET ... NOT NULL by constraints only.

Oliver Ford sent in a patch to add the GROUPS option to window functions.

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

Konstantin Knizhnik sent in another revision of a patch to add a projection
function to CREATE INDEX.

Konstantin Knizhnik sent in another revision of a patch to implement
auto-prepare.

Alexander Kuzmenkov sent in another revision of a patch to implement full merge
join on comparison clauses.

Konstantin Knizhnik sent in two more revisions of a patch to optimize secondary
indexes.

Robert Haas sent in another revision of a patch to improve processing at GATHER
nodes.

Raúl Marín Rodríguez sent in another revision of a patch to add pow() support
for pgbench.

Nikhil Sontakke and Peter Eisentraut traded patches to implement logical
decoding of two-phase transactions.

Alexander Kuzmenkov sent in another revision of a patch to implement CSN-based
snapshots.

Dang Minh Huong and Masahiko Sawada traded patches to fix an issue with
user-defined types in logical replication.

Craig Ringer sent in a patch to fix an issue where standby disconnect could
corrupt serialized reorder buffers.

Rajkumar Raghuwanshi sent in two revisions of a patch to implement
partition-wise join with default partitions.

Thomas Munro sent in another revision of a patch to support kqueue.

Nathan Bossart sent in a patch to fix some crash bugs in VACUUM.

Thomas Munro sent in another revision of a patch to fix es_query_dsa.

Nikita Glukhov and Alexander Korotkov traded patches to add compress methods for
SP-GiST.

Ashutosh Bapat sent in two revisions of a patch to mention ordered datums in
PartitionBoundInfoData comment.

Amit Kapila and Thomas Munro traded patches to fix the EXPLAIN ANALYZE output
for the parallel worker case.

Andres Freund sent in a patch to allow tupleslots to have a fixed tupledesc and
use same in executor nodes.

Andrew Dunstan sent in another revision of a patch to make ALTER TABLE ADD
COLUMN fast with DEFAULT.

Petr Jelínek sent in another revision of a patch to fix walsender timeouts when
decoding a large transaction.

Nikita Glukhov sent in two more revisions of a patch to implement compress
method for SP-GiST.

Álvaro Herrera sent in two more revisions of a patch to fix freezing of a dead
HOT-updated tuple.

Peter Eisentraut sent in another revision of a patch to implement transaction
control for procedures in the built-in PLs.

Anthony Bykov sent in another revision of a patch to implement a JSONB transform
for PL/PythonU.

David Rowley sent in another revision of a patch to remove Merge]Append nodes
which contain a single subpath.

Anthony Bykov sent in another revision of a patch to implement a JSONB transform
for PL/Perl.

Peter Geoghegan sent in another revision of a patch to add a Bloom filter data
structure implementation and use same to add amcheck verification of indexes
against heap.

Peter Eisentraut sent in a patch to start a separate test suite for PL/pgsql.

Alexander Korotkov sent in a patch to fix some pg_trgm word_similarity
inconsistencies.

Beena Emerson sent in another revision of a patch to implement runtime partition
pruning.

David Rowley sent in a patch to fix an out of date comment in cached_plan_cost.

Ian Barwick sent in a patch to add %r as part of the psql prompt format to show
recovery status.

Alexander Korotkov sent in another revision of a patch to fix contrib/cube's
KNN.

Rushabh Lathia sent in two more revisions of a patch to implement parallel
tuplesort for parallel B-tree index creation.

Thomas Munro sent in a patch to add defenses against pre-crash files to
BufFileOpenShared().

Thomas Munro sent in another revision of a patch to make SERIALIZABLE isolation
work with parallel query.

Etsuro Fujita sent in a patch to fix incorrect debug info printed in
generate_partition_wise_join_paths.

Alexander Korotkov sent in another revision of a patch to implement incremental
sort.

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

Masahiko Sawada sent in another revision of a patch to fix an assertion failure
when the non-exclusive pg_stop_backup aborted.

Amit Langote sent in a patch to teach operator_predicate_proof() to strip
RelabelType.

Andres Freund sent in a patch to provide overflow safe integer math inline
functions and hand code string to int32 conversion for performance.

Thomas Munro sent in a patch to add an extra barrier function to enable changing
the party size of a static barrier.

Peter Geoghegan sent in a patch to remove a leftover reference to replacement
selection 1 run case.

Tom Lane sent in a patch to refactor memory context creation.

Emre Hasegeli sent in a patch to fix a potential endless loop in polygon @>
polygon.