This is expected to be useful mostly when performing such scans in
parallel, because in that case it allows (in combination with commit
acf555bc) nodes below a Gather to get
control just before the DSM segment goes away.

KaiGai Kohei, except that I rewrote the documentation.  Reviewed by
Claudio Freire.

Discussion: http://postgr.es/m/CADyhKSXJK0jUJ8rWv4AmKDhsUh124_rEn39eqgfC5D8fu6xVuw@mail.gmail.com

I removed this in commit 9e3755ec, reasoning that the win32.h
port-specific header file included by c.h would have provided it.
However, that's only true on native win32 builds, not Cygwin builds.

It may be that some of the other <windows.h> inclusions also need
to be put back on the same grounds; but this is the only one that
is clearly meant to be included #ifdef __CYGWIN__, so maybe this is
the extent of the problem.  Awaiting further buildfarm results.

We had some AC_CHECK_HEADER tests that were really wastes of cycles,
because the code proceeded to #include those headers unconditionally
anyway, in all or a large majority of cases.  The lack of complaints
shows that those headers are available on every platform of interest,
so we might as well let configure run a bit faster by not probing
those headers at all.

I suspect that some of the tests I left alone are equally useless, but
since all the existing #includes of the remaining headers are properly
guarded, I didn't touch them.

c.h #includes a number of core libc header files, such as <stdio.h>.
There's no point in re-including these after having read postgres.h,
postgres_fe.h, or c.h; so remove code that did so.

While at it, also fix some places that were ignoring our standard pattern
of "include postgres[_fe].h, then system header files, then other Postgres
header files".  While there's not any great magic in doing it that way
rather than system headers last, it's silly to have just a few files
deviating from the general pattern.  (But I didn't attempt to enforce this
globally, only in files I was touching anyway.)

I'd be the first to say that this is mostly compulsive neatnik-ism,
but over time it might save enough compile cycles to be useful.

Previously the pg_upgrade standby upgrade instructions said not to
execute pgcrypto.sql, but it should have referenced the extension
command "CREATE EXTENSION pgcrypto".  This patch makes that doc change.

Reported-by: a private bug report

Backpatch-through: 9.4, where standby instructions were added

nan_test.pgc supposed that it could unconditionally #define isnan()
and isinf() on WIN32.  This was evidently copied at some point from
src/include/port/win32.h, but nowadays there's a test on _MSC_VER
there.  Make nan_test.pgc look the same.

Per buildfarm warnings.  There's no evidence this produces anything
worse than a warning, and besides it's only a test case, so I don't
feel a need to back-patch.

We have a portable way of writing uint64 constants, but whoever wrote
this macro didn't know about it.

While at it, fix unsafe under-parenthesization of arguments.  That might
be moot, because there are already good reasons not to use the macro on
anything more complicated than a simple variable, but it's still poor
practice.

Per buildfarm warnings.

This was an oversight in the original partitioning commit.

Amit Langote, reviewed by David Fetter

Discussion: http://postgr.es/m/59af6590-8ace-04c4-c36c-ea35d435c60e@lab.ntt.co.jp

If someone were to try to call one of the enum comparison functions
using DirectFunctionCallN, it would very likely seem to work, because
only in unusual cases does enum_cmp_internal() need to access the
typcache.  But once such a case occurred, code like that would crash
with a null pointer dereference.  To make an oversight of that sort
less likely to escape detection, add a non-bypassable Assert that
fcinfo->flinfo isn't NULL.

Discussion: https://postgr.es/m/25226.1487900067@sss.pgh.pa.us

Twiddle the replication-related code so that its timestamp variables
are declared TimestampTz, rather than the uninformative "int64" that
was previously used for meant-to-be-always-integer timestamps.
This resolves the int64-vs-TimestampTz declaration inconsistencies
introduced by commit 7c030783, though in the opposite direction to
what was originally suggested.

This required including datatype/timestamp.h in a couple more places
than before.  I decided it would be a good idea to slim down that
header by not having it pull in <float.h> etc, as those headers are
no longer at all relevant to its purpose.  Unsurprisingly, a small number
of .c files turn out to have been depending on those inclusions, so add
them back in the .c files as needed.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
Discussion: https://postgr.es/m/27694.1487456324@sss.pgh.pa.us

This is a basically mechanical removal of #ifdef HAVE_INT64_TIMESTAMP
tests and the negative-case controlled code.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us

We don't need it any more.

pg_controldata continues to report that date/time type storage is
"64-bit integers", but that's now a hard-wired behavior not something
it sees in the data.  This avoids breaking pg_upgrade, and perhaps other
utilities that inspect pg_control this way.  Ditto for pg_resetwal.

I chose to remove the "bigint_timestamps" output column of
pg_control_init(), though, as that function hasn't been around long
and probably doesn't have ossified users.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us

Per discussion, the time has come to do this.  The handwriting has been
on the wall at least since 9.0 that this would happen someday, whenever
it got to be too much of a burden to support the float-timestamp option.
The triggering factor now is the discovery that there are multiple bugs
in the code that attempts to implement use of integer timestamps in the
replication protocol even when the server is built for float timestamps.
The internal float timestamps leak into the protocol fields in places.
While we could fix the identified bugs, there's a very high risk of
introducing more.  Trying to build a wall that would positively prevent
mixing integer and float timestamps is more complexity than we want to
undertake to maintain a long-deprecated option.  The fact that these
bugs weren't found through testing also indicates a lack of interest
in float timestamps.

This commit disables configure's --disable-integer-datetimes switch
(it'll still accept --enable-integer-datetimes, though), removes direct
references to USE_INTEGER_DATETIMES, and removes discussion of float
timestamps from the user documentation.  A considerable amount of code is
rendered dead by this, but removing that will occur as separate mop-up.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us

reported by Shinoda, Noriyoshi <noriyoshi.shinoda@hpe.com>; partial
patch by Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>

This was only used for allowing upgrades from pre-7.3 instances, which
was a long time ago.

The logic for removing excess trigrams from the result was faulty.
It intends to avoid merging the initial and final states of the NFA,
which is necessary, but in testing whether removal of a specific trigram
would cause that, it failed to consider the combined effects of all the
state merges that that trigram's removal would cause.  This could result
in a broken final graph that would never match anything, leading to GIN
or GiST indexscans not finding anything.

To fix, add a "tentParent" field that is used only within this loop,
and set it to show state merges that we are tentatively going to do.
While examining a particular arc, we must chase up through tentParent
links as well as regular parent links (the former can only appear atop
the latter), and we must account for state init/fin flag merges that
haven't actually been done yet.

To simplify the latter, combine the separate init and fin bool fields
into a bitmap flags field.  I also chose to get rid of the "children"
state list, which seems entirely inessential.

Per bug #14563 from Alexey Isayko, which the added test cases are based on.
Back-patch to 9.3 where this code was added.

Report: https://postgr.es/m/20170222111446.1256.67547@wrigleys.postgresql.org
Discussion: https://postgr.es/m/8816.1487787594@sss.pgh.pa.us

Columns with array pseudotypes have not been identified as arrays, so
they have been rendered as strings in the json and jsonb conversion
routines. This change allows them to be rendered as json arrays, making
it possible to deal correctly with the anyarray columns in pg_stats.

With this change, you can see the query that a parallel worker is
executing in pg_stat_activity, and if the worker crashes you can
see what query it was executing when it crashed.

Rafia Sabih, reviewed by Kuntal Ghosh and Amit Kapila and slightly
revised by me.

Ashutosh Sharma, per a report from Mithun Cy.

Discussion: http://postgr.es/m/CAD__OujgqNNnCujeFTmKpjNu+W4smS8Hbi=RcWAhf1ZUs3H4WA@mail.gmail.com

It turns out that the original shutdown order here does not work well.
Multiple people attempting to develop further parallel query patches
have discovered that they need to do cleanup before the DSM goes away,
and you can't do that if the parent node gets cleaned up first.

Patch by me, reviewed by KaiGai Kohei and Dilip Kumar.

Discussion: http://postgr.es/m/CA+TgmoY6bOc1YnhcAQnMfCBDbsJzROQ3sYxSAL-SYB5tMJcTKg@mail.gmail.com
Discussion: http://postgr.es/m/9A28C8860F777E439AA12E8AEA7694F8012AEB82@BPXM15GP.gisp.nec.co.jp
Discussion: http://postgr.es/m/CA+TgmoYuPOc=+xrG1v0fCsoLbKAab9F1ddOeaaiLMzKOiBar1Q@mail.gmail.com

Yugo Nagata

Rearrange so we don't have an unused variable in disable-cassert case.

Discussion: https://postgr.es/m/CAMkU=1x63f2QyFTeas83xJqD+Hm1PBuok1LrzYzS-OngDzYOVA@mail.gmail.com

Several places in fd.c had badly-thought-through handling of error returns
from lseek() and close().  The fact that those would seldom fail on valid
FDs is probably the reason we've not noticed this up to now; but if they
did fail, we'd get quite confused.

LruDelete and LruInsert actually just Assert'd that lseek never fails,
which is pretty awful on its face.

In LruDelete, we indeed can't throw an error, because that's likely to get
called during error abort and so throwing an error would probably just lead
to an infinite loop.  But by the same token, throwing an error from the
close() right after that was ill-advised, not to mention that it would've
left the LRU state corrupted since we'd already unlinked the VFD from the
list.  I also noticed that really, most of the time, we should know the
current seek position and it shouldn't be necessary to do an lseek here at
all.  As patched, if we don't have a seek position and an lseek attempt
doesn't give us one, we'll close the file but then subsequent re-open
attempts will fail (except in the somewhat-unlikely case that a
FileSeek(SEEK_SET) call comes between and allows us to re-establish a known
target seek position).  This isn't great but it won't result in any state
corruption.

Meanwhile, having an Assert instead of an honest test in LruInsert is
really dangerous: if that lseek failed, a subsequent read or write would
read or write from the start of the file, not where the caller expected,
leading to data corruption.

In both LruDelete and FileClose, if close() fails, just LOG that and mark
the VFD closed anyway.  Possibly leaking an FD is preferable to getting
into an infinite loop or corrupting the VFD list.  Besides, as far as I can
tell from the POSIX spec, it's unspecified whether or not the file has been
closed, so treating it as still open could be the wrong thing anyhow.

I also fixed a number of other places that were being sloppy about
behaving correctly when the seekPos is unknown.

Also, I changed FileSeek to return -1 with EINVAL for the cases where it
detects a bad offset, rather than throwing a hard elog(ERROR).  It seemed
pretty inconsistent that some bad-offset cases would get a failure return
while others got elog(ERROR).  It was missing an offset validity check for
the SEEK_CUR case on a closed file, too.

Back-patch to all supported branches, since all this code is fundamentally
identical in all of them.

Discussion: https://postgr.es/m/2982.1487617365@sss.pgh.pa.us

There's some ongoing performance work on this area, so let's make sure
we don't break things.

Extracted from a larger patch originally by Stas Kelvich.

Authors: Stas Kelvich, Nikhil Sontakke, Michael Paquier
Discussion: https://postgr.es/m/CAMGcDxfsuLLOg=h5cTg3g77Jjk-UGnt=RW7zK57zBSoFsapiWA@mail.gmail.com

neha khatri

Previously the command forgot to close the connection to the publisher
when it failed to drop the replication slot.

Walsender uses the local buffers for each outgoing and incoming message.
Previously when creating replication slot, walsender forgot to initialize
one of them and which can cause the segmentation fault error. To fix this
issue, this commit changes walsender so that it always initialize them
before it executes the requested replication command.

Back-patch to 9.4 where replication slot was introduced.

Problem report and initial patch by Stas Kelvich, modified by me.
Report: https://www.postgresql.org/message-id/A1E9CB90-1FAC-4CAD-8DBA-9AA62A6E97C5@postgrespro.ru

The initial table synchronization feature has not been supported yet,
but there was the confusing header comment about it in logical/worker.c.

Creating global objects named "foo" isn't an especially wise thing,
but especially not in a test script that has already used that name
for something else, and most especially not in a script that runs
in parallel with other scripts that use that name :-(

Per buildfarm.

Commit 04aad401 added this check after the search for a Python shared
library, which seems to me to be a pretty unfriendly ordering.  The
search might fail for what are basically version-related reasons, and
in such a case it'd be better to say "your Python is too old" than
"could not find shared library for Python".

There is no specific reason for this right now, but keeping support for
old Python versions around indefinitely increases the maintenance
burden.  The oldest supported Python version is now Python 2.4, which is
still shipped in RHEL/CentOS 5 by default.

In configure, add a check for the required Python version and give a
friendly error message for an old version, instead of relying on an
obscure build error later on.

Replace incorrect word "index" with "heap"

Takayuki Tsunakawa

Be specific about which pattern is being complained of, and avoid saying
"it's not supported in to_date", which is just confusing if the error is
actually coming out of to_timestamp.  We can phrase it as "is only
supported in to_char", instead.  Also, use the term "formatting field" not
"format pattern", because other error messages in the same file prefer that
terminology.  (This isn't terribly consistent with the documentation, so
maybe we should change all these error messages?)

These are only supported in to_char, not in the other direction, but the
documentation failed to mention that.  Also, describe TZ/tz as printing the
time zone "abbreviation", not "name", because what they print is elsewhere
referred to that way.  Per bug #14558.

It failed to remove a .o file during "make clean", and it lacked
a .gitignore file entirely.

It didn't take long at all for me to become irritated that the original
choice of name for this script resulted in "warning" showing up in several
places in build logs, because I tend to grep for that.  Change the script
name to avoid that.

One case in the PL/Tcl tests is observed to fail on RHEL5 with a Turkish
time zone setting.  It's not clear if this is an old Tcl bug or something
odd about the zone data, but in any case that test is meant to see if the
Tcl [clock] command works at all, not what its corner-case behaviors are.
Therefore we have no need to test exactly which week a Sunday midnight is
considered to fall into.  Probe the following Tuesday instead.

Discussion: https://postgr.es/m/797.1487517822@sss.pgh.pa.us