Commit 16fa9b2b broke the ability to reliably test GiST buffered builds,
because it caused sorted builds to be done instead if sortsupport is
available, regardless of any attempt to override that.  While a would-be
test case could try to work around that by choosing an opclass that has
no sortsupport function, coverage would be silently lost the moment
someone decides it'd be a good idea to add a sortsupport function.

Hence, rearrange the logic in gistbuild() so that if "buffering = on"
is specified in CREATE INDEX, we will use that method, sortsupport or no.

Also document the interaction between sorting and the buffering
parameter, as 16fa9b2b failed to do.

(Note that in fact we still lack any test coverage of buffered builds,
but this is a prerequisite to adding a non-fragile test.)

Discussion: https://postgr.es/m/3249980.1602532990@sss.pgh.pa.us

The prohibitValueChange code paths in set_config_option(), which
are executed whenever we re-read a PGC_POSTMASTER variable from
postgresql.conf, neglected to free anything before exiting.  Thus
we'd leak the proposed new value of a PGC_STRING variable, as noted
by BoChen in bug #16666.  For all variable types, if the check hook
creates an "extra" chunk, we'd also leak that.

These are malloc not palloc chunks, so there is no mechanism for
recovering the leaks before process exit.  Fortunately, the values
are typically not very large, meaning you'd have to go through an
awful lot of SIGHUP configuration-reload cycles to make the leakage
amount to anything.  Still, for a long-lived postmaster process it
could potentially be a problem.

Oversight in commit 2594cf0e.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/16666-2c41a4eec61b03e1@postgresql.org

Use GetLastError(), rather than assuming that CreateFile() failure
must map to ENOENT.  Noted by Michael Paquier.

Discussion: https://postgr.es/m/CAC+AXB0g44SbvSpC86o_1HWh8TAU2pZrMRW6tJT-dkijotx5Qg@mail.gmail.com

80f8eb79 has introduced in unicode_norm.c some new code that uses
htonl().  On at least some FreeBSD environments, it is possible to find
that this function is undeclared, causing a compilation warning.  It is
worth noting that no buildfarm members have reported this issue.

Instead of adding a new inclusion to arpa/inet.h, switch to use
the equivalent defined in pg_bswap.h, to benefit from any built-in
function if the compiler has one.

Reported-by: Masahiko Sawada
Discussion: https://postgr.es/m/CA+fd4k7D4b12ShywWj=AbcHZzV1-OqMjNe7RZAu+tgz5rd_11A@mail.gmail.com

In the past, we always estimated that a ModifyTable node would emit the
same number of rows as its subpaths.  Without a RETURNING clause, the
correct estimate is zero.  Fix, in preparation for a proposed parallel
write patch that is sensitive to that number.

A remaining problem is that for RETURNING queries, the estimated width
is based on subpath output rather than the RETURNING tlist.
Reviewed-by: Greg Nancarrow <gregn4422@gmail.com>
Discussion: https://postgr.es/m/CAJcOf-cXnB5cnMKqWEp2E2z7Mvcd04iLVmV%3DqpFJrR3AcrTS3g%40mail.gmail.com

Adjust the existing cycle detection example and test queries to put
the cycle column before the path column.  This is mainly because the
SQL-standard CYCLE clause puts them in that order, and so if we added
that feature that would make the sequence of examples more consistent
and easier to follow.

Discussion: https://www.postgresql.org/message-id/c5603982-0088-7f14-0caa-fdcd0c837b57@2ndquadrant.com

The implementation uses smaller code when the "expected" operand is a
small constant, but the implementation needlessly defined the set of
acceptable constants more narrowly than the ABI does.  Core PostgreSQL
and PGXN don't use the constant path at all, so this is future-proofing.
Back-patch to v13, where commit 30ee5d17
introduced this code.

Reviewed by Tom Lane.  Reported by Christoph Berg.

Discussion: https://postgr.es/m/20201009092825.GD889580@msg.df7cb.de

While xlc defines __64BIT__, gcc does not.  Due to this oversight in
commit 30ee5d17, gcc builds continued
implementing 64-bit atomics by way of intrinsics.  Back-patch to v13,
where that commit first appeared.

Reviewed by Tom Lane.

Discussion: https://postgr.es/m/20201011051043.GA1724101@rfd.leadboat.com

This makes the normalization quick check about 30% faster for NFC and
50% faster for NFKC than the binary search used previously.  The hash
lookup reuses the existing array of bit fields used for the binary
search to get the quick check property and is generated as part of "make
update-unicode" in src/common/unicode/.

Author: John Naylor
Reviewed-by: Mark Dilger, Michael Paquier
Discussion: https://postgr.es/m/CACPNZCt4fbJ0_bGrN5QPt34N4whv=mszM0LMVQdoa2rC9UMRXA@mail.gmail.com

Buildfarm member lorikeet is still failing the test from commit
32a9c0bd, but now it's down to the should-have-foreseen-it problem
that the error message isn't what the expected-output file expects.
Let's see if we can get stable results by printing just the SQLSTATE.
I believe we'll reliably see ERRCODE_CONNECTION_FAILURE, since
pgfdw_report_error() will report that for any libpq-originated error.

There may be a better way to do this, but I'd like to get the
buildfarm back to green before we discuss further improvements.

Discussion: https://postgr.es/m/E1kPc9v-0005L4-2l@gemulon.postgresql.org
Discussion: https://postgr.es/m/2621622.1602184554@sss.pgh.pa.us

Commit fe27009c tried to make parallel.c's Windows implementation of
piperead() translate Windows socket errors to Unix, but that didn't
actually work because TranslateSocketError() is backend-internal code
(and not even public there).  But on closer inspection, the sole
caller of this function doesn't actually care whether the result is
zero or negative, much less inspect the errno.  So the whole exercise
is totally useless, and has been since this code was introduced.
Rip it out and just call recv() directly.

Per buildfarm.

Discussion: https://postgr.es/m/2621622.1602184554@sss.pgh.pa.us

Fix silly typo in previous commit.

Discussion: https://postgr.es/m/CAC+AXB0g44SbvSpC86o_1HWh8TAU2pZrMRW6tJT-dkijotx5Qg@mail.gmail.com

Ensure that CloseHandle() can't clobber the errno we set for
failure exits, and make a couple of tweaks for pgindent.

Juan José Santamaría Flecha

Discussion: https://postgr.es/m/CAC+AXB0g44SbvSpC86o_1HWh8TAU2pZrMRW6tJT-dkijotx5Qg@mail.gmail.com

Up to now, only ECONNRESET (and EPIPE, in most but not quite all places)
received special treatment in our error handling logic.  This patch
changes things so that related error codes such as ECONNABORTED are
also recognized as indicating that the connection's dead and unlikely
to come back.

We continue to think, however, that only ECONNRESET and EPIPE should be
reported as probable server crashes; the other cases indicate network
connectivity problems but prove little about the server's state.  Thus,
there's no change in the error message texts that are output for such
cases.  The key practical effect is that errcode_for_socket_access()
will report ERRCODE_CONNECTION_FAILURE rather than
ERRCODE_INTERNAL_ERROR for a network failure.  It's expected that this
will fix buildfarm member lorikeet's failures since commit 32a9c0bd,
as that seems to be due to not treating ECONNABORTED equivalently to
ECONNRESET.

The set of errnos treated this way now includes ECONNABORTED, EHOSTDOWN,
EHOSTUNREACH, ENETDOWN, ENETRESET, and ENETUNREACH.  Several of these
were second-class citizens in terms of their handling in places like
get_errno_symbol(), so upgrade the infrastructure where necessary.

As committed, this patch assumes that all these symbols are defined
everywhere.  POSIX specifies all of them except EHOSTDOWN, but that
seems to exist on all platforms of interest; we'll see what the
buildfarm says about that.

Probably this should be back-patched, but let's see what the buildfarm
thinks of it first.

Fujii Masao and Tom Lane

Discussion: https://postgr.es/m/2621622.1602184554@sss.pgh.pa.us

Needed now that commit bed90759 caused win32_port.h to provide
a #define for that too.  Per buildfarm.

Hack things so that our idea of "struct stat" is equivalent to Windows'
struct __stat64, allowing it to have a wide enough st_size field.

Instead of relying on native stat(), use GetFileInformationByHandle().
This avoids a number of issues with Microsoft's multiple and rather
slipshod emulations of stat().  We still need to jump through hoops
to deal with ERROR_DELETE_PENDING, though :-(

Pull the relevant support code out of dirmod.c and put it into
its own file, win32stat.c.

Still TODO: do we need to do something different with lstat(),
rather than treating it identically to stat()?

Juan José Santamaría Flecha, reviewed by Emil Iggland;
based on prior work by Michael Paquier, Sergey Zubkovsky, and others

Discussion: https://postgr.es/m/1803D792815FC24D871C00D17AE95905CF5099@g01jpexmbkw24
Discussion: https://postgr.es/m/15858-9572469fd3b73263@postgresql.org

Reviewed-by: Sawada  Masahiko
Discussion: https://postgr.es/m/CAA4eK1K6zTpuqf_d7wXCBjo_EF0_B6Fz3Ecp71Vq18t=wG-nzg@mail.gmail.com

Multiply before dividing, not the reverse, so that cases that should
produce exact results do produce exact results.  (width_bucket_float8
got this right already.)  Even when the result is inexact, this avoids
making it more inexact, since only the division step introduces any
imprecision.

While at it, fix compute_bucket() to not uselessly repeat the sign
check already done by its caller, and avoid duplicating the
multiply/divide steps by adjusting variable usage.

Per complaint from Martin Visser.  Although this seems like a bug fix,
I'm hesitant to risk changing width_bucket()'s results in stable
branches, so no back-patch.

Discussion: https://postgr.es/m/6FA5117D-6AED-4656-8FEF-B74AC18FAD85@brytlyt.com

While the calculation is not well-defined if the bounds arguments are
infinite, there is a perfectly sane outcome if the test operand is
infinite: it's just like any other value that's before the first bucket
or after the last one.  width_bucket_float8() got this right, but
I was too hasty about the case when adding infinities to numerics
(commit a57d312a), so that width_bucket_numeric() just rejected it.
Fix that, and sync the relevant error message strings.

No back-patch needed, since infinities-in-numeric haven't shipped yet.

Discussion: https://postgr.es/m/2465409.1602170063@sss.pgh.pa.us

AtEOXact_MultiXact() was referenced in two places with an incorrect
routine name.

Author: Hou Zhijie
Discussion: https://postgr.es/m/1b41e9311e8f474cb5a360292f0b3cb1@G08CNEXMBPEKD05.g08.fujitsu.local

The previous set of multipliers was not adapted for large sets of short
keys, and this new set of multipliers allows to generate perfect hash
functions for larger sets without having an impact for existing callers
of those functions, as experimentation has showed.  A future commit will
make use of that to improve the performance of unicode normalization.

All multipliers compile to shift-and-add instructions on most platforms.
This has been tested as far back as gcc 4.1 and clang 3.8.

Author: John Naylor
Reviewed-by: Mark Dilger, Michael Paquier
Discussion: https://postgr.es/m/CACPNZCt4fbJ0_bGrN5QPt34N4whv=mszM0LMVQdoa2rC9UMRXA@mail.gmail.com

This adds the statistics about transactions spilled to disk from
ReorderBuffer. Users can query the pg_stat_replication_slots view to check
these stats and call pg_stat_reset_replication_slot to reset the stats of
a particular slot. Users can pass NULL in pg_stat_reset_replication_slot
to reset stats of all the slots.

This commit extends the statistics collector to track this information
about slots.

Author: Sawada Masahiko and Amit Kapila
Reviewed-by: Amit Kapila and Dilip Kumar
Discussion: https://postgr.es/m/CA+fd4k5_pPAYRTDrO2PbtTOe0eHQpBvuqmCr8ic39uTNmR49Eg@mail.gmail.com

It appears that commit cf63c641, which intended to prevent
misoptimization of the result-building step in makeOrderedSetArgs,
didn't go far enough: buildfarm member hornet's version of xlc
is now optimizing back to the old, broken behavior in which
list_length(directargs) is fetched only after list_concat() has
changed that value.  I'm not entirely convinced whether that's
an undeniable compiler bug or whether it can be justified by a
sufficiently aggressive interpretation of C sequence points.
So let's just change the code to make it harder to misinterpret.

Back-patch to all supported versions, just in case.

Discussion: https://postgr.es/m/1830491.1601944935@sss.pgh.pa.us

The date-vs-timestamp, date-vs-timestamptz, and timestamp-vs-timestamptz
comparators all worked by promoting the first type to the second and
then doing a simple same-type comparison.  This works fine, except
when the conversion result is out of range, in which case we throw an
entirely avoidable error.  The sources of such failures are
(a) type date can represent dates much farther in the future than
the timestamp types can;
(b) timezone rotation might cause a just-in-range timestamp value to
become a just-out-of-range timestamptz value.

Up to now we just ignored these corner-case issues, but now we have
an actual user complaint (bug #16657 from Huss EL-Sheikh), so let's
do something about it.

It turns out that commit 52ad1e65 already built all the necessary
infrastructure to support error-free comparisons, but neglected to
actually use it in the main-line code paths.  Fix that, do a little
bit of code style review, and remove the now-duplicate logic in
jsonpath_exec.c.

Back-patch to v13 where 52ad1e65 came in.  We could take this back
further by back-patching said infrastructure, but given the small
number of complaints so far, I don't feel a great need to.

Discussion: https://postgr.es/m/16657-cde2f876d8cc7971@postgresql.org

Oversight in 4d29e6db.

Commit 3eb3d3e7 was a few bricks shy of a load: while it correctly
set the table's "interesting" flag when deciding to dump the data of
an extension config table, it was not correct to clear that flag
if we concluded we shouldn't dump the data.  This led to the crash
reported in bug #16655, because in fact we'll traverse dumpTableSchema
anyway for all extension tables (to see if they have user-added
seclabels or RLS policies).

The right thing to do is to force "interesting" true in makeTableDataInfo,
and otherwise leave the flag alone.  (Doing it there is more future-proof
in case additional calls are added, and it also avoids setting the flag
unnecessarily if that function decides the table is non-dumpable.)

This investigation also showed that while only the --inserts code path
had an obvious failure in the case considered by 3eb3d3e7, the COPY
code path also has a problem with not having loaded table subsidiary
data.  That causes fmtCopyColumnList to silently return an empty string
instead of the correct column list.  That accidentally mostly works,
which perhaps is why we didn't notice this before.  It would only fail
if the restore column order is different from the dump column order,
which only happens in weird inheritance cases, so it's not surprising
nobody had hit the case with an extension config table.  Nonetheless,
it's a bug, and it goes a long way back, not just to v12 where the
--inserts code path started to have a problem with this.

In hopes of catching such cases a bit sooner in future, add some
Asserts that "interesting" has been set in both dumpTableData and
dumpTableSchema.  Adjust the test case added by 3eb3d3e7 so that it
checks the COPY rather than INSERT form of that bug, allowing it to
detect the longer-standing symptom.

Per bug #16655 from Cameron Daniel.  Back-patch to all supported
branches.

Discussion: https://postgr.es/m/16655-5c92d6b3a9438137@postgresql.org
Discussion: https://postgr.es/m/18048b44-3414-b983-8c7c-9165b177900d@2ndQuadrant.com

In logical replication when a subscriber is missing some columns, it
currently emits an error message that says "some" columns are missing, but
it doesn't specify the missing column names. Change that to display
missing column names which makes an error to be more informative to the
user.

We have decided not to backpatch this commit as this is a minor usability
improvement and no user has reported this.

Reported-by: Bharath Rupireddy
Author: Bharath Rupireddy
Reviewed-by: Kyotaro Horiguchi and Amit Kapila
Discussion: https://postgr.es/m/CALj2ACVkW-EXH_4pmBK8tNeHRz5ksUC4WddGactuCjPiBch-cg@mail.gmail.com

We only support upgrading from >= 8.4 so no need for this code or tests.

Reported-by: Magnus Hagander

Discussion: https://postgr.es/m/CABUevEx-D0PNVe00tkeQRGennZQwDtBJn=493MJt-x6sppbUxA@mail.gmail.com

Backpatch-through: 9.5

This makes checking for older major versions more consistent.

Backpatch-through: 9.5

This patch prevents crashes or wrong plans when partition-wise joins
are considered during GEQO planning, as a consequence of the
EquivalenceClass data structures becoming corrupt after a GEQO
context reset.

A remaining problem is that successive GEQO cycles will make multiple
copies of the required EC members, since add_child_join_rel_equivalences
has no idea that such members might exist already.  For now we'll just
live with that.  The lack of field complaints of crashes suggests that
this is a mighty little-used situation.

Back-patch to v12 where this code was introduced.

Discussion: https://postgr.es/m/1683100.1601860653@sss.pgh.pa.us

Ian submitted an updated patch just as I was pushing the previous one,
so use this newer wording instead.

Author: Ian Barwick

The behavior is different for different types of objects, so make that
more clear.

Author: Ian Barwick

Reviewed-By: David G. Johnston, Daniel Gustafsson

Oversight in 9d0bd95.

Reported-by: Andres Freund
Discussion: https://postgr.es/m/20201006023802.qqfi6m5bw5y77zql@alap3.anarazel.de

Thanks to Andrew for proposing and testing this fix.

It's possible that we should address this on a more fundamental basis,
e.g. by configuring PerlIO to to CR/LF conversion for us, but this
approach already exists in other places. And it's nice to unbreak the
BF.
Proposed-By: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Discussion: https://postgr.es/m/2355d1f0-0244-da9c-ef0c-7542b944e1ac@2ndQuadrant.com

In postgres_fdw, once remote connections are established, they are cached
and re-used for subsequent queries and transactions. There can be some
cases where those cached connections are unavaiable, for example,
by the restart of remote server. In these cases, previously an error was
reported and the query accessing to remote server failed if new remote
transaction failed to start because the cached connection was broken.

This commit improves postgres_fdw so that new connection is remade
if broken connection is detected when starting new remote transaction.
This is useful to avoid unnecessary failure of queries when connection is
broken but can be reestablished.

Author: Bharath Rupireddy, tweaked a bit by Fujii Masao
Reviewed-by: Ashutosh Bapat, Tatsuhito Kasahara, Fujii Masao
Discussion: https://postgr.es/m/CALj2ACUAi23vf1WiHNar_LksM9EDOWXcbHCo-fD4Mbr1d=78YQ@mail.gmail.com

Previously it was unclear exactly how ROWS FROM behaved and how to cast
the data types of columns returned by FROM functions.  Also document
that only non-OUT record functions can have their columns cast to data
types.

Reported-by: guyren@gmail.com

Discussion: https://postgr.es/m/158638264419.662.2482095087061084020@wrigleys.postgresql.org

Backpatch-through: 9.5

Since PG 12, clientcert no longer supported only on/off, so remove 1/0
as possible values, and instead support only the text strings
'verify-ca' and 'verify-full'.

Remove support for 'no-verify' since that is possible by just not
specifying clientcert.

Also, throw an error if 'verify-ca' is used and 'cert' authentication is
used, since cert authentication requires verify-full.

Also improve the docs.

THIS IS A BACKWARD INCOMPATIBLE API CHANGE.

Reported-by: Kyotaro Horiguchi

Discussion: https://postgr.es/m/20200716.093012.1627751694396009053.horikyota.ntt@gmail.com

Author: Kyotaro Horiguchi

Backpatch-through: master

This should help to identify what happened when studying the postmaster
log after-the-fact.

While here, clean up some old comments in the same function.

Discussion: https://postgr.es/m/1568983.1601845687@sss.pgh.pa.us

get_eclass_for_sort_expr() computes expr_relids and nullable_relids
early on, even though they won't be needed unless we make a new
EquivalenceClass, which we often don't.  Aside from the probably-minor
inefficiency, there's a memory management problem: these bitmapsets will
be built in the caller's context, leading to dangling pointers if that
is shorter-lived than root->planner_cxt.  This would be a live bug if
get_eclass_for_sort_expr() could be called with create_it = true during
GEQO join planning.  So far as I can find, the core code never does
that, but it's hard to be sure that no extensions do, especially since
the comments make it clear that that's supposed to be a supported case.
Fix by not computing these values until we've switched into planner_cxt
to build the new EquivalenceClass.

generate_join_implied_equalities() uses inner_rel->relids to look up
relevant eclasses, but it ought to be using nominal_inner_relids.
This is presently harmless because a child RelOptInfo will always have
exactly the same eclass_indexes as its topmost parent; but that might
not be true forever, and anyway it makes the code confusing.

The first of these is old (introduced by me in f3b3b8d5), so back-patch
to all supported branches.  The second only dates to v13, but we might
as well back-patch it to keep the code looking similar across branches.

Discussion: https://postgr.es/m/1508010.1601832581@sss.pgh.pa.us