Since 573bd08b, hardcoded DH parameters have been moved to a different
file, making the comment on top of load_dh_buffer() incorrect.

Author: Daniel Gustafsson
Discussion: https://postgr.es/m/D9492CCB-9A91-4181-A847-1779630BE2A7@yesql.se

This broke the project rule to not call any complex code while a
spinlock is held.  Issue introduced by b89e1510.

Discussion: https://postgr.es/m/20200602.161518.1399689010416646074.horikyota.ntt@gmail.com
Backpatch-through: 9.5

Fix some more violations of the "only straight-line code inside a
spinlock" rule.  These are hazardous not only because they risk
holding the lock for an excessively long time, but because it's
possible for palloc to throw elog(ERROR), leaving a stuck spinlock
behind.

copy_replication_slot() had two separate places that did pallocs
while holding a spinlock.  We can make the code simpler and safer
by copying the whole ReplicationSlot struct into a local variable
while holding the spinlock, and then referencing that copy.
(While that's arguably more cycles than we really need to spend
holding the lock, the struct isn't all that big, and this way seems
far more maintainable than copying fields piecemeal.  Anyway this
is surely much cheaper than a palloc.)  That bug goes back to v12.

InvalidateObsoleteReplicationSlots() not only did a palloc while
holding a spinlock, but for extra sloppiness then leaked the memory
--- probably for the lifetime of the checkpointer process, though
I didn't try to verify that.  Fortunately that silliness is new
in HEAD.

pg_get_replication_slots() had a cosmetic violation of the rule,
in that it only assumed it's safe to call namecpy() while holding
a spinlock.  Still, that's a hazard waiting to bite somebody, and
there were some other cosmetic coding-rule violations in the same
function, so clean it up.  I back-patched this as far as v10; the
code exists before that but it looks different, and this didn't
seem important enough to adapt the patch further back.

Discussion: https://postgr.es/m/20200602.161518.1399689010416646074.horikyota.ntt@gmail.com

Use "guc-enable-groupingsets-hash-disk".

Reported-by: TAKATSUKA Haruka

Discussion: https://postgr.es/m/16468-7939d39f1786516c@postgresql.org

Backpatch-through: master

The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
but previously their documents were located in
"Replication"/"Sending Servers" section. This commit moves them to
the proper section "Write Ahead Log"/"Settings".

Back-patch to v12 where wal_init_zero and wal_recycle parameters
were introduced.

Author: Fujii Masao
Discussion: https://postgr.es/m/b5190ab4-a169-6a42-0e49-aed0807c8976@oss.nttdata.com

Previously UpdateSpillStats() called elog(DEBUG2) while holding
the spinlock even though the local variables that the elog() accesses
don't need to be protected by the lock. Since spinlocks are intended
for very short-term locks, they should not be used when calling
elog(DEBUG2). So this commit moves that elog() out of spinlock period.

Author: Kyotaro Horiguchi
Reviewed-by: Amit Kapila and Fujii Masao
Discussion: https://postgr.es/m/20200602.161518.1399689010416646074.horikyota.ntt@gmail.com

Reported-by: Sawada Masahiko
Author: Sawada Masahiko, Amit Kapila
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CA+fd4k4vNg7dRO5ECHdtQXXf1=Q4M98pfLW0dU7BKD8h79pkqA@mail.gmail.com

The recipe was previously given in comments in the module's test
script, but now we have an explicit recipe in the Makefile. The now
redundant comments in the script are removed.

This recipe shouldn't be needed in normal use, as the certificate and
key are in git and don't need to be regenerated.

Discussion: https://postgr.es/m/ae8f21fc-95cb-c98a-f241-1936133f466f@2ndQuadrant.com

This issue has been present since the introduction of this code as of
a3519a2f from 2002, and has been found by buildfarm member prion that
uses RELCACHE_FORCE_RELEASE via the tests introduced recently in
e786be5f.

Discussion: https://postgr.es/m/20200601022055.GB4121@paquier.xyz
Backpatch-through: 9.5

A relation that has no storage initializes rd_tableam to NULL, which
caused those two functions to crash because of a pointer dereference.
Note that in 11 and older versions, this has always failed with a
confusing error "could not open file".

These two functions are used by the Postgres ODBC driver, which requires
them only when connecting to a backend strictly older than 8.1.  When
connected to 8.2 or a newer version, the driver uses a RETURNING clause
instead whose support has been added in 8.2, so it should be possible to
just remove both functions in the future.  This is left as an issue to
address later.

While on it, add more regression tests for those functions as we never
really had coverage for them, and for aggregates of TIDs.

Reported-by: Jaime Casanova, via sqlsmith
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/CAJGNTeO93u-5APMga6WH41eTZ3Uee9f3s8dCpA-GSSqNs1b=Ug@mail.gmail.com
Backpatch-through: 12

Also add a top-level install-tests target.

Backpatch to all live branches.

Craig Ringer, tweaked by me.

Commit 1f39bce0 added disk-based hash aggregation, which may spill
incoming tuples to disk. It however did not request projection to make
the tuples as narrow as possible, which may mean having to spill much
more data than necessary (increasing I/O, pushing other stuff from page
cache, etc.).

This adds CP_SMALL_TLIST in places that may use hash aggregation - we do
that only for AGG_HASHED. It's unnecessary for AGG_SORTED, because that
either uses explicit Sort (which already does projection) or pre-sorted
input (which does not need spilling to disk).

Author: Tomas Vondra
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/20200519151202.u2p2gpiawoaznsv2%40development

The documentation of REINDEX includes a complete description of
CONCURRENTLY and its advantages as well as its disadvantages, but
reindexdb was not really clear about all that.

From discussion with Tom Lane, based on a report from Andrey Klychkov.

Discussion: https://postgr.es/m/1590486572.205117372@f500.i.mail.ru
Backpatch-through: 12

This commit updates the "Viewing Statistics" section more like
the existing catalogs chapter.

- Change its layout so that an introductory paragrap is put above
   the table for each statistics view. Previously the explanations
   were below the tables.

- Separate each view to different section and add index terms for them.

Author: Fujii Masao
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/6f8a482c-b3fa-4ed9-21c3-6d222a2cb87d@oss.nttdata.com

LLVM has removed this header, in the branch that will become llvm
11. But as it turns out we didn't actually need it, so just remove it.

Author: Jesse Zhang <sbjesse@gmail.com>
Discussion: https://postgr.es/m/CAGf+fX7bvtP0YXMu7pOsu_NwhxW6dArTkxb=jt7M2-UJkyJ_3g@mail.gmail.com
Backpatch: 11, where JIT support using llvm was introduced.

Two of the members of rconn were left uninitialized. When
dblink_open() is called without an outer transaction it
handles the initialization for us, but with an outer
transaction it does not. Arrange for initialization
in all cases. Backpatch to all supported versions.

Reported-by: Alexander Lakhin
Discussion: https://www.postgresql.org/message-id/flat/9bd0744f-5f04-c778-c5b3-809efe9c30c7%40joeconway.com#c545909a41664991aca60c4d70a10ce7

The repeat() function loops for potentially a long time without
ever checking for interrupts. This prevents, for example, a query
cancel from interrupting until the work is all done. Fix by
inserting a CHECK_FOR_INTERRUPTS() into the loop.

Backpatch to all supported versions.

Discussion: https://www.postgresql.org/message-id/flat/8692553c-7fe8-17d9-cbc1-7cddb758f4c6%40joeconway.com

ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE was used in an ereport with the
same message but different errdetail a few lines earlier, so use that
here as well.

Backpatch-through: 11

The same comment was copied to a few different places, with the same typo.
Backpatch down to v11, where this typo was introduced.

segment_open and segment_close were mentioned with incorrect names.

Discussion: https://postgr.es/m/20200525234944.GA1573@paquier.xyz

The default unit for max_slot_wal_keep_size is megabytes.  While on it,
also change temp_file_limit to use a more consistent wording.

Reported-by: Jeff Janes, Fujii Masao
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/CAMkU=1wWZhhjpwRFKJ9waQGxxROeC0P6UqPvb90fAaGz7dhoHA@mail.gmail.com

This is not handled uniformly throughout the code, but at least nearby
code can be consistent.

Disk-based HashAgg relies on writing to multiple tapes
concurrently. Avoid fragmentation of the tapes' blocks by
preallocating many blocks for a tape at once. No file operations are
performed during preallocation; only the block numbers are reserved.

Reviewed-by: Tomas Vondra
Discussion: https://postgr.es/m/20200519151202.u2p2gpiawoaznsv2%40development

Make the wording of new libpq messages more similar to existing
messages in the backend.

This was done for all scanners in
42116736 but not added to the new one.

Reported-by: Daniel Gustafsson

Discussion: https://postgr.es/m/54F7560D-498A-4E51-BAA4-17D4AAB2AA57@yesql.se

Backpatch-through: master

These were missed when these were added to pg_hba.conf in PG 12;
updates docs and pg_hba.conf.sample.

Reported-by: Arthur Nascimento

Bug: 16380

Discussion: https://postgr.es/m/20200421182736.GG19613@momjian.us

Backpatch-through: 12

The stmt_len changes do not affect behavior.  LimitPath has no other
support functions, so that part changes only debugging output.

The target failed, tested $PATH binaries, or tested a stale temporary
installation.  Commit c66b438d missed
this.  Back-patch to 9.5 (all supported versions).

pg_shmem_allocations was in the wrong position with pg_stats.

Author: Ian Barwick
Discussion: https://postgr.es/m/de7279d4-7ea0-037f-d7d2-1161682339db@2ndquadrant.com

The following commands have been missing calls to object access hooks
InvokeObjectPost{Create|Alter}Hook normally applied to all commands:
- ALTER RULE RENAME TO
- ALTER USER MAPPING
- CREATE ACCESS METHOD
- CREATE STATISTICS

Thanks also to Robert Haas for the discussion.

Author: Mark Dilger
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/435CD295-F409-44E0-91EC-DF32C7AFCD76@enterprisedb.com

They were introduced in 898e5e32; backpatch to 12.

Explain that the followings are tracked only when track_io_timing GUC
is enabled.

- blk_read_time and blk_write_time in pg_stat_database
- time spent reading and writing data file blocks in EXPLAIN output
   with BUFFERS option

Whther track_io_timing is enabled affects also blk_read_time and
blk_write_time in pg_stat_statements, but which was already documented.

Author: Atsushi Torikoshi
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CACZ0uYHo_NwbxpLH76OGF-O=13tkR0ZM0zeyGEhZ+JEXZVRyCA@mail.gmail.com

Probably copied from nearby calls where it is necessary.  But this one
also casts away constness, so it was doubly annoying.

The previous indentation of optimizer functions was unclear; adjust the
indentation dashes so that a deeper level of indentation indicates that
the outer optimizer function calls the inner one.

Author: Richard Guo, with additional change by me
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/CAMbWs4-U-ogzpchGsP2BBMufCss1hktm%2B%2BeTJK_dUC196pw0cQ%40mail.gmail.com

Reported-by: Erwin Brandstetter

Discussion: https://postgr.es/m/CAGHENJ4X626ZfYhondXSP4sQgC5zDtsp_LNg1QaD+U7vfgYXQQ@mail.gmail.com

Backpatch-through: head

Reported-by: Erwin Brandstetter

Discussion: https://postgr.es/m/CAGHENJ4X626ZfYhondXSP4sQgC5zDtsp_LNg1QaD+U7vfgYXQQ@mail.gmail.com

Backpatch-through: head

Reported-by: yigong hu

Discussion: https://postgr.es/m/CAOxFffcourucFqSk+tZA13ErS3XRYkDy6EeaPff4AvHGiEEuug@mail.gmail.com

Backpatch-through: 9.5

Discussion: https://postgr.es/m/2304.1586532634@sss.pgh.pa.us

Backpatch-through: 9.5