Input functions for the inserted tuples may require a snapshot, when
they are replayed by native logical replication.  An example is a domain
with a constraint using a SQL-language function, which prior to this
commit failed to apply on the subscriber side.
Reported-by: Mai Peng <maily.peng@webedia-group.com>
Co-authored-by: Minh-Quan TRAN <qtran@itscaro.me>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/4EB4BD78-BFC3-4D04-B8DA-D53DF7160354@webedia-group.com
Discussion: https://postgr.es/m/153211336163.1404.11721804383024050689@wrigleys.postgresql.org

Move out of the concurrency control chapter, where mostly only user
table locks are discussed, and move to CREATE COLLATION reference page.

Author: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>

pg_dump knew about printing ALTER TABLE ... REPLICA IDENTITY USING INDEX
for indexes declared as indexes, but it failed to print that for indexes
declared as unique or primary-key constraints.  Per report from Achilleas
Mantzios.

This has been broken since the feature was introduced, AFAICS.
Back-patch to 9.4.

Discussion: https://postgr.es/m/1e6cc5ad-b84a-7c07-8c08-a4d0c3cdc938@matrix.gatewaynet.com

As written, this policy constrained only the post-image not the pre-image
of rows, meaning that users could delete other users' rows or take
ownership of such rows, contrary to what the docs claimed would happen.
We need two separate policies to achieve the documented effect.

While at it, try to explain what's happening a bit more fully.

Per report from Олег Самойлов.  Back-patch to 9.5 where this was added.
Thanks to Stephen Frost for off-list discussion.

Discussion: https://postgr.es/m/3298321532002010@sas1-2b3c3045b736.qloud-c.yandex.net

This allows querying the SSL implementation used on the server side.
It's analogous to using PQsslAttribute(conn, "library") in libpq.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>

Perpendicular lines always intersect, so the line_interpt_line() return
value in line_closept_point() was used only in an assertion, triggering
compiler warnings in non-assert builds.

Commit a7dc63d9 inadvertedly removed this bit originally introduced
by 43fe90f6, causing regression test failures on some platforms,
due to producing {1,-1,-0} instead of {1,-1,0}.

Affected test queries have been testing the wrong thing since their
introduction in commit 4c1383ef.
Back-patch to 9.3 (all supported versions).

There is a copy-paste error from bt_page_items() which got into
bt_page_items_bytea().  A second message in get_raw_page_internal() was
inconsistent with all the other sub-modules.

Author: Ashutosh Sharma
Discussion: https://postgr.es/m/CAE9k0PnZuZ3PVXSyQY91-53E8JKFcaSyknFqqU43r9MabKSYZA@mail.gmail.com

The recheck option became a no-op as ClusterOption failed to set proper
values for each element.  There was a second code path where local
options got overwritten.

Both issues have been spotted by Coverity.

Commit 5770172c documented secure schema
usage, and that advice suffices for using unqualified names securely.
Document, in typeconv-func primarily, the additional issues that arise
with qualified names.  Back-patch to 9.3 (all supported versions).

Reviewed by Jonathan S. Katz.

Discussion: https://postgr.es/m/20180721012446.GA1840594@rfd.leadboat.com

Some data types under adt/ have separate header files, but most simple
ones do not, and their public functions are defined in builtins.h.  As
the patches improving geometric types will require making additional
functions public, this seems like a good opportunity to create a header
for floats types.

Commit 1acf7572 made _cmp functions public to solve NaN issues locally
for GiST indexes.  This patch reworks it in favour of a more widely
applicable API.  The API uses inline functions, as they are easier to
use compared to macros, and avoid double-evaluation hazards.

Author: Emre Hasegeli
Reviewed-by: Kyotaro Horiguchi

Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com

The primary goal of this patch is to eliminate duplicate code and share
code between different geometric data types more often, to prepare the
ground for additional patches.  Until now the code reuse was limited,
probably because the simpler types (line and point) were implemented
after the more complex ones.

The changes are quite extensive and can be summarised as:

* Eliminate SQL-level function calls.
* Re-use more functions to implement others.
* Unify internal function names and signatures.
* Remove private functions from geo_decls.h.
* Replace should-not-happen checks with assertions.
* Add comments describe for various functions.
* Remove some unreachable code.
* Define delimiter symbols of line datatype like the other ones.
* Remove the GEODEBUG macro and printf() calls.
* Unify code style of a few oddly formatted lines.

While the goal was to cause minimal user-visible changes, it was not
possible to keep the original behavior in all cases - for example when
handling NaN values, or when reusing code makes the functions return
consistent results.

Author: Emre Hasegeli
Reviewed-by: Kyotaro Horiguchi, me

Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com

This is useful to know when the data copy has been finished.  The
current situation can be confusing for users as the last message is
"waiting for background process to finish streaming", so it looks like
this is taking time but the final sync is instead.

Author: Jeff Janes
Discussion: https://postgr.es/m/CAMkU=1ypeoMJ=tFBG8vP13sxEtXd4Pm_x1SqsJdW_RvzpcvN=A@mail.gmail.com

This allows for cleaner error reporting.

Backpatch-through: 9.5

Previously pg_upgrade checked for the pid file and started/stopped the
server to force a clean shutdown.  However, "pg_ctl -m immediate"
removes the pid file but doesn't do a clean shutdown, so check
pg_controldata for a clean shutdown too.

Diagnosed-by: Vimalraj A

Discussion: https://postgr.es/m/CAFKBAK5e4Q-oTUuPPJ56EU_d2Rzodq6GWKS3ncAk3xo7hAsOZg@mail.gmail.com

Backpatch-through: 9.3

Previously only the missing library name was reported, forcing users to
look in all databases to find the library entries.

Discussion: https://postgr.es/m/20180713162815.GA3835@momjian.us

Author: Daniel Gustafsson, me

Since PG 9.5, 'make check' records the build output in install.log, so
look in there for warnings too.

Backpatch-through: 9.5

In our B-tree implementation appropriate leaf page for new tuple
insertion is acquired using _bt_search() function.  This function always
returns leaf page locked in shared mode.  In order to obtain exclusive
lock, caller have to relock the page.

This commit makes _bt_search() function lock leaf page immediately in
exclusive mode when needed.  That removes unnecessary relock and, in
turn reduces lock contention for B-tree leaf pages.  Our experiments
on multi-core systems showed acceleration up to 4.5 times in corner
case.

Discussion: https://postgr.es/m/CAPpHfduAMDFMNYTCN7VMBsFg_hsf0GqiqXnt%2BbSeaJworwFoig%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Yoshikazu Imai, Simon Riggs, Peter Geoghegan

Author: Brad DeJong
Discussion: https://postgr.es/m/CAJnrtnxrA4FqZi0Z6kGPQKMiZkWv2xxgSDQ+hv1jDrf8WCKjjw@mail.gmail.com

Instead of repeatedly fishing the data out of the relcache entry,
let's use the version that we cached in the PartitionDispatch.  We
could alternatively rip out the PartitionDispatch fields altogether,
but it doesn't make much sense to have them and not use them; before
this patch, partdesc was set but altogether unused.  Amit Langote and
I both thought using them was a litle better than removing them, so
this patch takes that approach.

Discussion: http://postgr.es/m/CA+TgmobFnxcaW-Co-XO8=yhJ5pJXoNkCj6Z7jm9Mwj9FGv-D7w@mail.gmail.com

During parallel index scans, if the current page to be read is deleted, we
skip it and try to get the next page for a scan without releasing the buffer
lock on the current page.  To get the next page, sometimes it needs to wait
for another process to complete its scan and advance it to the next page.
Now, it is quite possible that the master backend has errored out before
advancing the scan and issued a termination signal for all workers.  The
workers failed to notice the termination request during wait because the
interrupts are held due to buffer lock on the previous page.  This lead to
all workers being stuck.

The fix is to release the buffer lock on current page before trying to get
the next page.  We are already doing same in backward scans, but missed
it for forward scans.

Reported-by: Victor Yegorov
Bug: 15290
Diagnosed-by: Thomas Munro and Amit Kapila
Author: Amit Kapila
Reviewed-by: Thomas Munro
Tested-By: Thomas Munro and Victor Yegorov
Backpatch-through: 10 where parallel index scans were introduced
Discussion: https://postgr.es/m/153228422922.1395.1746424054206154747@wrigleys.postgresql.org

Depending on the platform used, this can cause a crash in the worst
case, or an unhelpful error message, so fail gracefully.

Author: Fabien Coelho
Discussion: https://postgr.es/m/alpine.DEB.2.21.1807262302550.29874@lancre
Backpatch: 11-, where hash() has been added in pgbench.

We suppressed one of these test cases in commit feb1cc55 because
it was failing to produce the expected results on CLOBBER_CACHE_ALWAYS
buildfarm members.  But now we need another test with similar behavior,
so let's set up a test file that is expected to vary between regular and
CLOBBER_CACHE_ALWAYS cases, and provide variant expected files.

Someday we should fix plpgsql's failure for change-of-field-type, and
then the discrepancy will go away and we can fold these tests back
into plpgsql_record.sql.  But today is not that day.

Discussion: https://postgr.es/m/87wotkfju1.fsf@news-spur.riddles.org.uk

Since commit 6719b238 it's been possible for the values of plpgsql
record field variables to be exposed to the planner as Params.
(Before that, plpgsql never supplied values for such variables during
planning, so that the problematic code wasn't reached.)  Other places
that touch potentially-type-mutable Params either cope gracefully or
do runtime-test-and-ereport checks that the type is what they expect.
But eval_const_expressions() just had an Assert, meaning that it either
failed the assertion or risked crashes due to using an incompatible
value.

In this case, rather than throwing an ereport immediately, we can just
not perform a const-substitution in case of a mismatch.  This seems
important for the same reason that the Param fetch was speculative:
we might not actually reach this part of the expression at runtime.

Test case will follow in a separate commit.

Patch by me, pursuant to bug report from Andrew Gierth.
Back-patch to v11 where the previous commit appeared.

Discussion: https://postgr.es/m/87wotkfju1.fsf@news-spur.riddles.org.uk

Due to inlining it previously was possible that an ExprContext's
shutdown callback pointed to a JITed function. As the JIT context
previously was shut down before the shutdown callbacks were called,
that could lead to segfaults.  Fix the ordering.

Reported-By: Dmitry Dolgov
Author: Andres Freund
Discussion: https://postgr.es/m/CA+q6zcWO7CeAJtHBxgcHn_hj+PenM=tvG0RJ93X1uEJ86+76Ug@mail.gmail.com
Backpatch: 11-, where JIT compilation was added

Previously the attribute was only checked for external functions
inlined, not "static" functions that had to be inlined as
dependencies.

This isn't really a bug, but makes debugging a bit harder. The new
behaviour also makes more sense. Therefore backpatch.

Author: Andres Freund
Backpatch: 11-, where JIT compilation was added

Until now shadowed_variables was the only plpgsql check supported by
plpgsql.extra_warnings and plpgsql.extra_errors.  This patch introduces
two new checks - strict_multi_assignment and too_many_rows.  Unlike
shadowed_variables, these new checks are enforced at run-time.

strict_multi_assignment checks that commands allowing multi-assignment
(for example SELECT INTO) have the same number of sources and targets.
too_many_rows checks that queries with an INTO clause return one row
exactly.

These checks are aimed at cases that are technically valid and allowed,
but are often a sign of a bug.  Therefore those checks are expected to
be enabled primarily in development and testing environments.

Author: Pavel Stehule
Reviewed-by: Stephen Frost, Tomas Vondra
Discussion: https://www.postgresql.org/message-id/flat/CAFj8pRA2kKRDKpUNwLY0GeG1OqOp+tLS2yQA1V41gzuSz-hCng@mail.gmail.com

In a USE_UNNAMED_SEMAPHORES build, the default on Linux and FreeBSD
since commit ecb0d20a, we have an array of sem_t objects.  This
turned out to reduce performance compared to the previous default
USE_SYSV_SEMAPHORES on an 8 socket system.  Testing showed that the
lost performance could be regained by padding the array elements so
that they have their own cache lines.  This matches what we do for
similar hot arrays (see LWLockPadded, WALInsertLockPadded).

Back-patch to 10, where unnamed semaphores were adopted as the default
semaphore interface on those operating systems.

Author: Thomas Munro
Reviewed-by: Andres Freund
Reported-by: Mithun Cy
Tested-by: Mithun Cy, Tom Lane, Thomas Munro
Discussion: https://postgr.es/m/CAD__OugYDM3O%2BdyZnnZSbJprSfsGFJcQ1R%3De59T3hcLmDug4_w%40mail.gmail.com

Author: Jonathan Katz
Discussion: https://postgr.es/m/DD02DD86-5989-4BFD-8712-468541F68383@postgresql.org
Backpatch: 9.4-, where logical decoding was added

Author: David Rowley
Discussion: https://postgr.es/m/CAKJS1f-AbCFeFU92GZZYqNOVRnPtUwczSYmR2NHCyf9uHUnNiw@mail.gmail.com

This extends cluster_rel() in such a way that more options can be added
in the future, which will reduce the amount of chunk code for an
upcoming SKIP_LOCKED aimed for VACUUM.  As VACUUM FULL is a different
flavor of CLUSTER, we want to make that extensible to ease integration.

This only reworks the API and its callers, without providing anything
user-facing.  Two options are present now: verbose mode and relation
recheck when doing the cluster command work across multiple
transactions.  This could be used as well as a base to extend the
grammar of CLUSTER later on.

Author: Michael Paquier
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/20180723031058.GE2854@paquier.xyz

Commit 4b0d28de has removed the prior checkpoint and related
facilities but has left WAL recycling based on the LSN of the prior
checkpoint, which causes incorrect calculations for WAL removal and
recycling for max_wal_size and min_wal_size.  This commit changes things
so as the base calculation point is the last checkpoint generated.

Reported-by: Kyotaro Horiguchi
Author: Kyotaro Horiguchi
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/20180723.135748.42558387.horiguchi.kyotaro@lab.ntt.co.jp
Backpatch: 11-, where the prior checkpoint has been removed.

FreeBSD has introduced a faster variant of setproctitle().  Use it,
where available.

Author: Thomas Munro
Discussion: https://postgr.es/m/CAEepm=1wKMTi81uodJ=1KbJAz5WedOg=cr8ewEXrUFeaxWEgww@mail.gmail.com

Fabien Coelho

Discussion: http://postgr.es/m/alpine.DEB.2.21.1807221822320.19939@lancre

During the work of upstreaming my previous patches for gdb and perf
support the API changed. Adapt.  Normally this wouldn't necessarily be
something to backpatch, but the previous API wasn't upstream, and at
least the gdb support is quite useful for debugging.

Author: Andres Freund
Backpatch: 11, where LLVM based JIT support was added.

The location of LLVMAddPromoteMemoryToRegisterPass moved.

Author: Andres Freund
Backpatch: 11, where LLVM based JIT support was added.

While no negative consequences are currently known, it's clearly wrong
to not reset the context in one of the branches.

Reported-By: Dmitry Dolgov
Author: Dmitry Dolgov
Discussion: https://postgr.es/m/CAGPqQf165-=+Drw3Voim7M5EjHT1zwPF9BQRjLFQzCzYnNZEiQ@mail.gmail.com
Backpatch: 11-, where JIT compilation support was added