Check at compile time that RETURN in a procedure does not specify a
parameter, rather than at run time.

If convert_to_scalar is passed a pair of datatypes it can't cope with,
its former behavior was just to elog(ERROR).  While this is OK so far as
the core code is concerned, there's extension code that would like to use
scalarltsel/scalargtsel/etc as selectivity estimators for operators that
work on non-core datatypes, and this behavior is a show-stopper for that
use-case.  If we simply allow convert_to_scalar to return FALSE instead of
outright failing, then the main logic of scalarltsel/scalargtsel will work
fine for any operator that behaves like a scalar inequality comparison.
The lack of conversion capability will mean that we can't estimate to
better than histogram-bin-width precision, since the code will effectively
assume that the comparison constant falls at the middle of its bin.  But
that's still a lot better than nothing.  (Someday we should provide a way
for extension code to supply a custom version of convert_to_scalar, but
today is not that day.)

While poking at this issue, we noted that the existing code for handling
type bytea in convert_to_scalar is several bricks shy of a load.
It assumes without checking that if the comparison value is type bytea,
the bounds values are too; in the worst case this could lead to a crash.
It also fails to detoast the input values, so that the comparison result is
complete garbage if any input is toasted out-of-line, compressed, or even
just short-header.  I'm not sure how often such cases actually occur ---
the bounds values, at least, are probably safe since they are elements of
an array and hence can't be toasted.  But that doesn't make this code OK.

Back-patch to all supported branches, partly because author requested that,
but mostly because of the bytea bugs.  The change in API for the exposed
routine convert_network_to_scalar() is theoretically a back-patch hazard,
but it seems pretty unlikely that any third-party code is calling that
function directly.

Tomas Vondra, with some adjustments by me

Discussion: https://postgr.es/m/b68441b6-d18f-13ab-b43b-9a72188a4e02@2ndquadrant.com

Replace "checkpoint segment" with "WAL segment".
Reported-by: Maksim Milyutin <milyutinma@gmail.com>

In PostgreSQL 9.5, the documentation for pg_stat_replication was moved,
so some of the links pointed to an appropriate location.

Author: Maksim Milyutin <milyutinma@gmail.com>

Follow-up to 4b95cc1d

Author: Nikolay Shaplov <dhyan@nataraj.su>

Separate out the pg_attribute logic of genbki.pl into its own function.
Drop unnecessary "defined $catalog->{data}" check.  This both narrows
and shortens the data writing loop of the script.  There is no functional
change (the emitted files are the same as before).

John Naylor

Discussion: https://postgr.es/m/CAJVSVGXnLH=BSo0x-aA818f=MyQqGS5nM-GDCWAMdnvQJTRC1A@mail.gmail.com

Rationalize a couple of macro names:
* In catalog/pg_init_privs.h, rename Anum_pg_init_privs_privs to
  Anum_pg_init_privs_initprivs to match the column's actual name.
* In ecpg, rename ZPBITOID to BITOID to match catalog/pg_type.h.
This reduces reader confusion, and will allow us to generate these
macros automatically in future.

In catalog/pg_tablespace.h, fix the ordering of related DATA and
#define lines to agree with how it's done elsewhere.  This has no
impact today, but simplifies life for the bootstrap data conversion
scripts.

John Naylor

Discussion: https://postgr.es/m/CAJVSVGXnLH=BSo0x-aA818f=MyQqGS5nM-GDCWAMdnvQJTRC1A@mail.gmail.com

This prevents silently using a wrong configuration, similar to
b4e2ada3.

Add checks in each test file that the build supports the feature,
otherwise skip all the tests.  Before, if someone were to (accidentally)
invoke these tests without build support, they would fail in confusing
ways.

based on patch from Michael Paquier <michael@paquier.xyz>

The SSL and LDAP test suites are not run by default, as they are not
secure for multi-user environments.  This commit adds an extra make
variable to optionally enable them, for example:

make check-world PG_TEST_EXTRA='ldap ssl'

Author: Michael Paquier <michael@paquier.xyz>

Sloppy coding in this function could lead to leaking a VM buffer pin,
or to attempting to free the same pin twice.  Repair.  While at it,
reduce the code's tendency to free and reacquire the same page pin.

Back-patch to 9.6; before that, this routine did not concern itself
with VM pages.

Amit Kapila and Tom Lane

Discussion: https://postgr.es/m/CAA4eK1KJKwhc=isgTQHjM76CAdVswzNeAuZkh_cx-6QgGkSEgA@mail.gmail.com

Previously, it'd try to create log files under the source directory
not the build directory.  This fell over if the source isn't writable
by the building user.

Fabien Coelho

Discussion: https://postgr.es/m/alpine.DEB.2.20.1801101038340.2283@lancre

The new column distinguishes normal functions, procedures, aggregates,
and window functions.  This replaces the existing columns proisagg and
proiswindow, and replaces the convention that procedures are indicated
by prorettype == 0.  Also change prorettype to be VOIDOID for procedures.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Michael Paquier <michael@paquier.xyz>

Commit 1bc0100d added this test, and
commits 882ea509,
958e20e4,
4fa39646 tried to stabilize it.  It's
still not stable, so keep trying.

The latest comment from Tom Lane is that disabling autovacuum seems
like a good strategy, but we might need to do it on more tables, hence
this patch.

Etsuro Fujita

Discussion: http://postgr.es/m/5A9928F1.2010206@lab.ntt.co.jp

Instead of marking data from the ringer buffer consumed and setting the
sender's latch for every message, do it only when the amount of data we
can consume is at least 1/4 of the size of the ring buffer, or when no
data remains in the ring buffer.  This is dramatically faster in my
testing; apparently, the savings from sending signals less frequently
outweighs the benefit of letting the sender know about available buffer
space sooner.

Patch by me, reviewed by Andres Freund and tested by Rafia Sabih.

Discussion: http://postgr.es/m/CA+TgmoYK7RFj6r7KLEfSGtYZCi3zqTRhAz8mcsDbUAjEmLOZ3Q@mail.gmail.com

Previously, mq_bytes_read and mq_bytes_written were protected by the
spinlock, but that turns out to cause pretty serious spinlock
contention on queries which send many tuples through a Gather or
Gather Merge node.  This patches changes things so that we instead
read and write those values using 8-byte atomics.  Since mq_bytes_read
can only be changed by the receiver and mq_bytes_written can only be
changed by the sender, the only purpose of the spinlock is to prevent
reads and writes of these values from being torn on platforms where
8-byte memory access is not atomic, making the conversion fairly
straightforward.

Testing shows that this produces some slowdown if we're using emulated
64-bit atomics, but since they should be available on any platform
where performance is a primary concern, that seems OK.  It's faster,
sometimes a lot faster, on platforms where such atomics are available.

Patch by me, reviewed by Andres Freund, who also suggested the
design.  Also tested by Rafia Sabih.

Discussion: http://postgr.es/m/CA+TgmoYuK0XXxmUNTFT9TSNiBtWnRwasBcHHRCOK9iYmDLQVPg@mail.gmail.com

Author: Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoDSGfB0G4egOy2UvBT=uihojuh-syxgSipj+XNkpWdVzQ@mail.gmail.com

Previously, it just returned the heap tuple count, which might be only an
estimate, and would be completely the wrong thing if the index is partial.
Since this function scans every index page anyway to find free pages,
it's practically free to count the surviving index tuples.  Let's do that
and return an accurate count.

This is easily visible as a wrong reltuples value for a partial GiST
index following VACUUM, so back-patch to all supported branches.

Andrey Borodin, reviewed by Michail Nikolaev

Discussion: https://postgr.es/m/151956654251.6915.675951950408204404.pgcf@coridan.postgresql.org

From this version ActivePerl ships both a .lib and a .a file for the
perl library, which our code would detect as there being no library
available. Instead, we should pick the .lib version and use that.

Report and suggested fix in bug #15065

Author: Heath Lord

For consistency with other code that deals in numbers of buckets, the
macro BUCKETS_PER_PARTITION should produce a value of type size_t.
Also, fix a mention of an obsolete proposed name for dshash.c that
appeared in a comment.

Author: Thomas Munro, based on an observation from Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1%2BBOp5aaW3aHEkg5Bptf8Ga_BkBnmA-%3DXcAXShs0yCiYQ%40mail.gmail.com

Since commit 0709b7ee, spinlock primitives include a compiler barrier
so it is no longer necessary to access either spinlocks or the memory
they protect through pointer-to-volatile.  Like earlier commits
e93b6298, d53e3d5f, 430008b5, 8f6bb851, df4077cd.

Author: Thomas Munro
Discussion: https://postgr.es/m/CAEepm=204T37SxcHo4=xw5btho9jQ-=ZYYrVdcKyz82XYzMoqg@mail.gmail.com

These errors have been seen in the field in corrupted-data situations.
It seems worthwhile to report them with ERRCODE_DATA_CORRUPTED, rather
than the generic ERRCODE_INTERNAL_ERROR, for the benefit of log monitoring
and tools like amcheck.  However, use errmsg_internal so that the text
strings still aren't translated; it seems unlikely to be worth
translators' time to do so.

Back-patch to 9.3, like the predecessor commit d70cf811 that introduced
these elog calls originally (replacing Asserts).

Peter Geoghegan

Discussion: https://postgr.es/m/CAH2-Wzmn4-Pg-UGFwyuyK-wiTih9j32pwg_7T9iwqXpAUZr=Mg@mail.gmail.com

Commit 4800f16a7ad0 added some sanity checks to ensure we don't
accidentally corrupt data, but in one of them we failed to consider the
effects of a database upgraded from 9.2 or earlier, where a tuple
exclusively locked prior to the upgrade has a slightly different bit
pattern.  Fix that by using the macro that we fixed in commit
74ebba84 for similar situations.

Reported-by: Alexandre Garcia
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/CAPYLKR6yxV4=pfW0Gwij7aPNiiPx+3ib4USVYnbuQdUtmkMaEA@mail.gmail.com

Andres suspects that this bug may have wider ranging consequences, but I
couldn't find anything.

Since 9.5, it's possible that some but not all columns of an index
support returning the indexed value for index-only scans.  If the
same indexed column appears in index columns that behave both ways,
check_index_only() supposed that it'd be OK to do an index-only scan
testing that column; but that fails if we have to recheck the indexed
condition on one of the columns that doesn't support this.

In principle we could make this work by remapping the recheck expressions
to pull the value from a column that does support returning the indexed
value.  But such cases are so weird and rare that, at least for now,
it doesn't seem worth the trouble.  Instead, just teach check_index_only
that a value is returnable only if all the index columns containing it
are returnable, rather than any of them.

Per report from David Pereiro Lagares.  Back-patch to 9.5 where the
possibility of this situation appeared.

Kyotaro Horiguchi

Discussion: https://postgr.es/m/1516210494.1798.16.camel@nlpgo.com

formrdesc's comment listed the specific catalogs it is called for,
but the list was out of date.  Rather than jumping back onto that
maintenance treadmill, let's just remove the list.  It tells the
reader nothing that can't be learned quickly and more reliably by
searching relcache.c for callers of formrdesc().

Oversight noted by Kyotaro Horiguchi.

Discussion: https://postgr.es/m/20180214.105314.138966434.horiguchi.kyotaro@lab.ntt.co.jp

Commit a26116c6 accidentally changed the behavior of the SQL format_type()
function while refactoring.  For the reasons explained in that function's
comment, a NULL typemod argument should behave differently from a -1
argument.  Since we've managed to break this, add a regression test
memorializing the intended behavior.

In passing, be consistent about the type of the "flags" parameter.

Noted by Rushabh Lathia, though I revised the patch some more.

Discussion: https://postgr.es/m/CAGPqQf3RB2q-d2Awp_-x-Ur6aOxTUwnApt-vm-iTtceZxYnePg@mail.gmail.com

A few isolationtester tests with reasonable names are too wide to
nicely align. Increase space.

Author: Thomas Munro
Discussion: https://postgr.es/m/CAEepm=2v7+EHs6zsJzFn+zJOT4F4Kb69Z1xJ7Zf5kgwLr1n=VA@mail.gmail.com

Author: Michael Paquier
Discussion: https://postgr.es/m/20180217140305.GB31338@paquier.xyz

Commit 924bcf4f added WaitForBackgroundWorkerShutdown, but didn't
add it to the documentation. Fix that and two small spelling errors in
the WaitForBackgroundWorkerStartup paragraph.

Author: Daniel Gustafsson
Discussion: https://postgr.es/m/C8738949-0350-4999-A1DA-26E209FF248D@yesql.se

Author: Ildar Musin
Reviewed-By: Fabian Coelho
Discussion: https://postgr.es/m/6376ed81-3ce8-14f4-4758-099872f4ce7d@postgrespro.ru

Author: Doug Rady
Discussion: https://postgr.es/m/6323D83C-9FDA-4EE1-B0ED-6971E585066A@amazon.com

Use IndexTupleSize everywhere, instead.  Also, remove IndexTupleSize's
internal typecast, as that's not really needed and might mask coding
errors.  Change some pointer variable datatypes in the call sites
to compensate for that and make it clearer what we're assuming.

Ildar Musin, Robert Haas, Stephen Frost

Discussion: https://postgr.es/m/0274288e-9e88-13b6-c61c-7b36928bf221@postgrespro.ru

Commit ff963b39 added two identical copies of this row.

Dagfinn Ilmari Mannsåker

Discussion: https://postgr.es/m/d8j8tdevb7x.fsf@dalvik.ping.uio.no

Solaris 11.4 has built-in functions named b64_encode and b64_decode.
Rename ours to something else to avoid the conflict (fortunately,
ours are static so the impact is limited).

One could wish for less duplication of code in this area, but that
would be a larger patch and not very suitable for back-patching.
Since this is a portability fix, we want to put it into all supported
branches.

Report and initial patch by Rainer Orth, reviewed and adjusted a bit
by Michael Paquier

Discussion: https://postgr.es/m/ydd372wk28h.fsf@CeBiTec.Uni-Bielefeld.DE

specscanner.l had a fixed limit of 1024 bytes on the length of
individual SQL stanzas in an isolation test script.  People are
starting to run into that, so fix it by making the buffer resizable.

Once we allow this in HEAD, it seems inevitable that somebody will
try to back-patch a test that exceeds the old limit, so back-patch
this change as a preventive measure.

Daniel Gustafsson

Discussion: https://postgr.es/m/8D628BE4-6606-4FF6-A3FF-8B2B0E9B43D0@yesql.se

The previous code considered two tables to have the partition scheme
if the underlying columns had the same collation, but what we
actually need to compare is not the collations associated with the
column but the collation used for partitioning.  Fix that.

Robert Haas and Amit Langote

Discussion: http://postgr.es/m/0f95f924-0efa-4cf5-eb5f-9a3d1bc3c33d@lab.ntt.co.jp

Thomas Munro

Discussion: http://postgr.es/m/CAEepm=3g1hhbFzYkR_QT9RmBvsGX4UaeCtX-4Js8OOEMmFeaSQ@mail.gmail.com

Parallel-aware plan nodes must be prepared to run without parallelism
if it's not possible at execution time for whatever reason.  Commit
ab727167, which introduced Parallel
Append, overlooked this.

Rajkumar Raghuwanshi reported this problem, and I included his test
case in this patch.  The code changes are by me.

Discussion: http://postgr.es/m/CAKcux6=WqkUudLg1GLZZ7fc5ScWC1+Y9qD=pAHeqy32WoeJQvw@mail.gmail.com

Commit 1bc0100d added this test,
and commit 882ea509 tried to
stabilize it.  There were still failures, so commit
958e20e4 tried again to stabilize
it.  That approach is still failing on jaguarundi, though, so
back it out and try something else.  Specifically, instead of
disabling remote estimates for the table in question, let's tell
autovacuum to leave it alone.

Etsuro Fujita

Discussion: http://postgr.es/m/5A82DCCE.3060107@lab.ntt.co.jp