Author: Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1KNv1Mg2krf4E9ssWFnE=8A9mZ1VbVywXBZTFSzb+wP2g@mail.gmail.com

... as well as its implementation from backend/access/hash/hashfunc.c to
backend/utils/hash/hashfn.c.

access/hash is the place for the hash index AM, not really appropriate
for generic facilities, which is what hash_any is; having things the old
way meant that anything using hash_any had to include the AM's include
file, pointlessly polluting its namespace with unrelated, unnecessary
cruft.

Also move the HTEqual strategy number to access/stratnum.h from
access/hash.h.

To avoid breaking third-party extension code, add an #include
"utils/hashutils.h" to access/hash.h.  (An easily removed line by
committers who enjoy their asbestos suits to protect them from angry
extension authors.)

Discussion: https://postgr.es/m/201901251935.ser5e4h6djt2@alvherre.pgsql

Instead, just proceed with the infinity or zero result that it should
return for overflow/underflow.  This avoids a platform dependency,
in that various versions of strtod are inconsistent about whether they
signal ERANGE for a value that's specified as infinity.

It's possible this won't be enough to remove the buildfarm failures
we're seeing from ac75959c, in which case I'll take out the infinity
test case that commit added.  But first let's see if we can fix it.

Discussion: https://postgr.es/m/E1h33xk-0001Og-Gs@gemulon.postgresql.org

shorter than 2 characters.

Patch by: "Wu, Fei" <wufei.fnst@cn.fujitsu.com>

opened in a prepared statement.

Patch by: "Kuroda, Hayato" <kuroda.hayato@jp.fujitsu.com>

Use was removed in 25ca5a9a.

Add a link to the specific command's reference web page to the bottom
of its \help output.

Discussion: https://www.postgresql.org/message-id/flat/40179bd0-fa7d-4108-1991-a20ae9ad5667%402ndquadrant.com

93473c6a has removed openLogOff, changing on the way the error message
which is used to report partial writes to WAL segments.  The
newly-introduced error message used the offset up to which the write has
happened, keeping always the same total length to write.  This changes
the error message so as the number of bytes left to write are reported.

Reported-by: Michael Paquier
Author: Robert Haas
Discussion: https://postgr.es/m/20190306235251.GA17293@paquier.xyz

1. The PARTITION OF clause of CREATE FOREIGN TABLE was not explained in
   the CREATE FOREIGN TABLE reference page.  Add it.
   (Postgres 10 onwards)

2. The limitation that tuple routing cannot target partitions that are
   foreign tables was not documented clearly enough.  Improve wording.
   (Postgres 10 onwards)

3. The UPDATE tuple re-routing concurrency behavior was explained in
   the DDL chapter, which doesn't seem the right place.  Move it to the
   UPDATE reference page instead.  (Postgres 11 onwards).

Authors: Amit Langote, David Rowley.
Reviewed-by: Etsuro Fujita.
Reported-by: Derek Hans
Discussion: https://postgr.es/m/CAGrP7a3Xc1Qy_B2WJcgAD8uQTS_NDcJn06O5mtS_Ne1nYhBsyw@mail.gmail.com

This is a better way to implement the desired change of increasing
autovacuum's default resource consumption.

Discussion: https://postgr.es/m/28720.1552101086@sss.pgh.pa.us

This reverts commit bd09503e.

Per discussion, it seems like what we should do instead is to
reduce the default value of autovacuum_vacuum_cost_delay by the
same factor.  That's functionally equivalent as long as the
platform can accurately service the smaller delay request, which
should be true on anything released in the last 10 years or more.
And smaller, more-closely-spaced delays are better in terms of
providing a steady I/O load.

Discussion: https://postgr.es/m/28720.1552101086@sss.pgh.pa.us

This change makes it possible to specify sub-millisecond delays,
which work well on most modern platforms, though that was not true
when the cost-delay feature was designed.

To support this without breaking existing configuration entries,
improve guc.c to allow floating-point GUCs to have units.  Also,
allow "us" (microseconds) as an input/output unit for time-unit GUCs.
(It's not allowed as a base unit, at least not yet.)

Likewise change the autovacuum_vacuum_cost_delay reloption to be
floating-point; this forces a catversion bump because the layout of
StdRdOptions changes.

This patch doesn't in itself change the default values or allowed
ranges for these parameters, and it should not affect the behavior
for any already-allowed setting for them.

Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us

This should reduce confusion in cases where we've applied a units
conversion, so that the number being reported (and the quoted range
limits) are in some other units than what the user gave in the
setting we're rejecting.

Some of the changes here assume that float GUCs can have units,
which isn't true just yet, but will be shortly.

Discussion: https://postgr.es/m/3811.1552169665@sss.pgh.pa.us

None of the code that uses GUC values is really prepared for them to
hold NaN, but parse_real() didn't have any defense against accepting
such a value.  Treat it the same as a syntax error.

I haven't attempted to analyze the exact consequences of setting any
of the float GUCs to NaN, but since they're quite unlikely to be good,
this seems like a back-patchable bug fix.

Note: we don't need an explicit test for +-Infinity because those will
be rejected by existing range checks.  I added a regression test for
that in HEAD, but not older branches because the spelling of the value
in the error message will be platform-dependent in branches where we
don't always use port/snprintf.c.

Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us

Since partitioned tables in pg12 do not have toast tables, trying to set
the toast OID confuses pg_upgrade.  Have pg_dump omit those values to
avoid the problem.

Per Andres Freund and buildfarm members crake and snapper
Discussion: https://postgr.es/m/20190306204104.yle5jfbnqkcwykni@alap3.anarazel.de

Similarly to B-tree, GiST index access method gets support of INCLUDE
attributes.  These attributes aren't used for tree navigation and aren't
present in non-leaf pages.  But they are present in leaf pages and can be
fetched during index-only scan.

The point of having INCLUDE attributes in GiST indexes is slightly different
from the point of having them in B-tree.  The main point of INCLUDE attributes
in B-tree is to define UNIQUE constraint over part of attributes enabled for
index-only scan.  In GiST the main point of INCLUDE attributes is to use
index-only scan for attributes, whose data types don't have GiST opclasses.

Discussion: https://postgr.es/m/73A1A452-AD5F-40D4-BD61-978622FF75C1%40yandex-team.ru
Author: Andrey Borodin, with small changes by me
Reviewed-by: Andreas Karlsson

Now that https://www.postgresql.org/docs/release/ is populated,
replace the stopgap text we had under "Prior Releases" with
a pointer to that archive.

Discussion: https://postgr.es/m/e0f09c9a-bd2b-862a-d379-601dfabc8969@postgresql.org

This allows a login to require both that the cn of the certificate
matches (like authentication type cert) *and* that another
authentication method (such as password or kerberos) succeeds as well.

The old value of clientcert=1 maps to the new clientcert=verify-ca,
clientcert=0 maps to the new clientcert=no-verify, and the new option
erify-full will add the validation of the CN.

Author: Julian Markwort, Marius Timmer
Reviewed by: Magnus Hagander, Thomas Munro

This adds a column that counts how many checksum failures have occurred
on files belonging to a specific database. Both checksum failures
during normal backend processing and those created when a base backup
detects a checksum failure are counted.

Author: Magnus Hagander
Reviewed by: Julien Rouhaud

When the timezone is UTC, timestamptz and timestamp are binary coercible
in both directions.  See b8a18ad4 and
c22ecc65 for the previous attempt in
this problem space.  Skip the table rewrite; for now, continue to
needlessly rewrite any index on an affected column.

Reviewed by Simon Riggs and Tom Lane.

Discussion: https://postgr.es/m/20190226061450.GA1665944@rfd.leadboat.com

This fixes two sets of issues related to the use of transient files in
the backend:
1) OpenTransientFile() has been used in some code paths with read-write
flags while read-only is sufficient, so switch those calls to be
read-only where necessary.  These have been reported by Joe Conway.
2) When opening transient files, it is up to the caller to close the
file descriptors opened.  In error code paths, CloseTransientFile() gets
called to clean up things before issuing an error.  However in normal
exit paths, a lot of callers of CloseTransientFile() never actually
reported errors, which could leave a file descriptor open without
knowing about it.  This is an issue I complained about a couple of
times, but never had the courage to write and submit a patch, so here we
go.

Note that one frontend code path is impacted by this commit so as an
error is issued when fetching control file data, making backend and
frontend to be treated consistently.

Reported-by: Joe Conway, Michael Paquier
Author: Michael Paquier
Reviewed-by: Álvaro Herrera, Georgios Kokolatos, Joe Conway
Discussion: https://postgr.es/m/20190301023338.GD1348@paquier.xyz
Discussion: https://postgr.es/m/c49b69ec-e2f7-ff33-4f17-0eaa4f2cef27@joeconway.com

Certain libxml2 versions (such as the 2.7.6 commonly seen in older
distributions, but apparently only on x86_64) contain a bug that causes
xmlCopyNode, when called on a XML_DOCUMENT_NODE, to return a node that
xmlFreeNode crashes on.  Arrange to call xmlFreeDoc instead of
xmlFreeNode for those nodes.

Per buildfarm members lapwing and grison.

Author: Pavel Stehule, light editing by Álvaro.
Discussion: https://postgr.es/m/20190308024436.GA2374@alvherre.pgsql

Test run for my previous commit; cleans up formatting issues in some
other recent commits.

Use Getopt::Long in preference to hand-rolled option parsing code.

Also, remove "-I .../backend/catalog" switch from the Makefile
invocations.  That's been unnecessary for some time, and leaving it
there gives the false impression it's needed in manual invocations.

John Naylor (extracted from a larger but more controversial patch)

Discussion: https://postgr.es/m/CACPNZCsHdcQN2jQ1=ptbi1Co2Nj3aHgRCUMk62=ThgWNabPY+Q@mail.gmail.com

tuple_data_split() lacked the type of the first argument, and
heap_page_item_attrs() has reversed the first and second argument,
with the bytea argument using an incorrect name.

Author: Laurenz Albe
Discussion: https://postgr.es/m/8f9ab7b16daf623e87eeef5203a4ffc0dece8dfd.camel@cybertec.at
Backpatch-through: 9.6

When 2dedf4d9 has integrated recovery.conf into postgresql.conf, it also
changed pg_basebackup -R in the way recovery configuration is
generated.  However this implementation forgot the fact that
pg_basebackup needs to keep compatibility with older server versions as
well.

Reported-by: Devrim Gündüz
Author: Sergei Kornilov, Michael Paquier
Discussion: https://postgr.es/m/3458f7cd12d74acd90180a671c8d5a081d60e162.camel@gunduz.org

Correctly process nodes of more types than previously.  In some cases,
nodes were being ignored (nothing was output); in other cases, trying to
return them resulted in errors about unrecognized nodes.  In yet other
cases, necessary escaping (of XML special characters) was not being
done.  Fix all those (as far as the authors could find) and add
regression tests cases verifying the new behavior.

I (Álvaro) was of two minds about backpatching these changes.  They do
seem bugfixes that would benefit most users of the affected functions;
but on the other hand it would change established behavior in minor
releases, so it seems prudent not to.

Authors: Pavel Stehule, Markus Winand, Chapman Flack
Discussion:
   https://postgr.es/m/CAFj8pRA6J25CtAZ2TuRvxK3gat7-bBUYh0rfE2yM7Hj9GD14Dg@mail.gmail.com
   https://postgr.es/m/8BDB0627-2105-4564-AA76-7849F028B96E@winand.at

The elephant in the room as pointed out by Chapman Flack, not fixed in
this commit, is that we still have XMLTABLE operating on XPath 1.0
instead of the standard-mandated XQuery (or even its subset XPath 2.0).
Fixing that is a major undertaking, however.

When we introduced separate ProjectSetPath nodes for application of
set-returning functions in v10, we inadvertently broke some cases where
we're supposed to recognize that the result of a subquery is known to be
empty (contain zero rows).  That's because IS_DUMMY_REL was just looking
for a childless AppendPath without allowing for a ProjectSetPath being
possibly stuck on top.  In itself, this didn't do anything much worse
than produce slightly worse plans for some corner cases.

Then in v11, commit 11cf92f6 rearranged things to allow the scan/join
targetlist to be applied directly to partial paths before they get
gathered.  But it inserted a short-circuit path for dummy relations
that was a little too short: it failed to insert a ProjectSetPath node
at all for a targetlist containing set-returning functions, resulting in
bogus "set-valued function called in context that cannot accept a set"
errors, as reported in bug #15669 from Madelaine Thibaut.

The best way to fix this mess seems to be to reimplement IS_DUMMY_REL
so that it drills down through any ProjectSetPath nodes that might be
there (and it seems like we'd better allow for ProjectionPath as well).

While we're at it, make it look at rel->pathlist not cheapest_total_path,
so that it gives the right answer independently of whether set_cheapest
has been done lately.  That dependency looks pretty shaky in the context
of code like apply_scanjoin_target_to_paths, and even if it's not broken
today it'd certainly bite us at some point.  (Nastily, unsafe use of the
old coding would almost always work; the hazard comes down to possibly
looking through a dangling pointer, and only once in a blue moon would
you find something there that resulted in the wrong answer.)

It now looks like it was a mistake for IS_DUMMY_REL to be a macro: if
there are any extensions using it, they'll continue to use the old
inadequate logic until they're recompiled, after which they'll fail
to load into server versions predating this fix.  Hopefully there are
few such extensions.

Having fixed IS_DUMMY_REL, the special path for dummy rels in
apply_scanjoin_target_to_paths is unnecessary as well as being wrong,
so we can just drop it.

Also change a few places that were testing for partitioned-ness of a
planner relation but not using IS_PARTITIONED_REL for the purpose; that
seems unsafe as well as inconsistent, plus it required an ugly hack in
apply_scanjoin_target_to_paths.

In passing, save a few cycles in apply_scanjoin_target_to_paths by
skipping processing of pre-existing paths for partitioned rels,
and do some cosmetic cleanup and comment adjustment in that function.

I renamed IS_DUMMY_PATH to IS_DUMMY_APPEND with the intention of breaking
any code that might be using it, since in almost every case that would
be wrong; IS_DUMMY_REL is what to be using instead.

In HEAD, also make set_dummy_rel_pathlist static (since it's no longer
used from outside allpaths.c), and delete is_dummy_plan, since it's no
longer used anywhere.

Back-patch as appropriate into v11 and v10.

Tom Lane and Julien Rouhaud

Discussion: https://postgr.es/m/15669-02fb3296cca26203@postgresql.org

We still require AccessExclusiveLock on the partition itself, because
otherwise an insert that violates the newly-imposed partition
constraint could be in progress at the same time that we're changing
that constraint; only the lock level on the parent relation is
weakened.

To make this safe, we have to cope with (at least) three separate
problems. First, relevant DDL might commit while we're in the process
of building a PartitionDesc.  If so, find_inheritance_children() might
see a new partition while the RELOID system cache still has the old
partition bound cached, and even before invalidation messages have
been queued.  To fix that, if we see that the pg_class tuple seems to
be missing or to have a null relpartbound, refetch the value directly
from the table. We can't get the wrong value, because DETACH PARTITION
still requires AccessExclusiveLock throughout; if we ever want to
change that, this will need more thought. In testing, I found it quite
difficult to hit even the null-relpartbound case; the race condition
is extremely tight, but the theoretical risk is there.

Second, successive calls to RelationGetPartitionDesc might not return
the same answer.  The query planner will get confused if lookup up the
PartitionDesc for a particular relation does not return a consistent
answer for the entire duration of query planning.  Likewise, query
execution will get confused if the same relation seems to have a
different PartitionDesc at different times.  Invent a new
PartitionDirectory concept and use it to ensure consistency.  This
ensures that a single invocation of either the planner or the executor
sees the same view of the PartitionDesc from beginning to end, but it
does not guarantee that the planner and the executor see the same
view.  Since this allows pointers to old PartitionDesc entries to
survive even after a relcache rebuild, also postpone removing the old
PartitionDesc entry until we're certain no one is using it.

For the most part, it seems to be OK for the planner and executor to
have different views of the PartitionDesc, because the executor will
just ignore any concurrently added partitions which were unknown at
plan time; those partitions won't be part of the inheritance
expansion, but invalidation messages will trigger replanning at some
point.  Normally, this happens by the time the very next command is
executed, but if the next command acquires no locks and executes a
prepared query, it can manage not to notice until a new transaction is
started.  We might want to tighten that up, but it's material for a
separate patch.  There would still be a small window where a query
that started just after an ATTACH PARTITION command committed might
fail to notice its results -- but only if the command starts before
the commit has been acknowledged to the user. All in all, the warts
here around serializability seem small enough to be worth accepting
for the considerable advantage of being able to add partitions without
a full table lock.

Although in general the consequences of new partitions showing up
between planning and execution are limited to the query not noticing
the new partitions, run-time partition pruning will get confused in
that case, so that's the third problem that this patch fixes.
Run-time partition pruning assumes that indexes into the PartitionDesc
are stable between planning and execution.  So, add code so that if
new partitions are added between plan time and execution time, the
indexes stored in the subplan_map[] and subpart_map[] arrays within
the plan's PartitionedRelPruneInfo get adjusted accordingly.  There
does not seem to be a simple way to generalize this scheme to cope
with partitions that are removed, mostly because they could then get
added back again with different bounds, but it works OK for added
partitions.

This code does not try to ensure that every backend participating in
a parallel query sees the same view of the PartitionDesc.  That
currently doesn't matter, because we never pass PartitionDesc
indexes between backends.  Each backend will ignore the concurrently
added partitions which it notices, and it doesn't matter if different
backends are ignoring different sets of concurrently added partitions.
If in the future that matters, for example because we allow writes in
parallel query and want all participants to do tuple routing to the same
set of partitions, the PartitionDirectory concept could be improved to
share PartitionDescs across backends.  There is a draft patch to
serialize and restore PartitionDescs on the thread where this patch
was discussed, which may be a useful place to start.

Patch by me.  Thanks to Alvaro Herrera, David Rowley, Simon Riggs,
Amit Langote, and Michael Paquier for discussion, and to Alvaro
Herrera for some review.

Discussion: http://postgr.es/m/CA+Tgmobt2upbSocvvDej3yzokd7AkiT+PvgFH+a9-5VV1oJNSQ@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmoZE0r9-cyA-aY6f8WFEROaDLLL7Vf81kZ8MtFCkxpeQSw@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmoY13KQZF-=HNTrt9UYWYx3_oYOQpu9ioNT49jGgiDpUEA@mail.gmail.com

This clause is used to indicate the passing mode of a XML document, but
we were doing it wrong: we accepted BY REF and ignored it, and rejected
BY VALUE as a syntax error.  The reality, however, is that documents are
always passed BY VALUE, so rejecting that clause was silly.  Change
things so that we accept BY VALUE.

BY REF continues to be accepted, and continues to be ignored.

Author: Chapman Flack
Reviewed-by: Pavel Stehule
Discussion: https://postgr.es/m/5C297BB7.9070509@anastigmatix.net

Per buildfarm

This is useful to speed up loading data in a different database engine.

Authors: Surafel Temesgen and David Rowley.  Lightly edited by Álvaro.
Reviewed-by: Fabien Coelho
Discussion: https://postgr.es/m/CALAY4q9kumSdnRBzvRJvSRf2+BH20YmSvzqOkvwpEmodD-xv6g@mail.gmail.com

Before commit 3fa2bb31 this type appeared in the catalogs to
select which of several block storage mechanisms each relation
used.

New features under development propose to revive the concept of
different block storage managers for new kinds of data accessed
via bufmgr.c, but don't need to put references to them in the
catalogs.  So, avoid useless maintenance work on this type by
dropping it.  Update some regression tests that were referencing
it where any type would do.

Discussion: https://postgr.es/m/CA%2BhUKG%2BDE0mmiBZMtZyvwWtgv1sZCniSVhXYsXkvJ_Wo%2B83vvw%40mail.gmail.com

Until now the the slot to store the conflicting tuple, and the result
of the ON CONFLICT SET, where reused between partitions. That
necessitated changing slots descriptor when switching partitions.

Besides the overhead of switching descriptors on a slot (which
requires memory allocations and prevents JITing), that's importantly
also problematic for tableam. There individual partitions might belong
to different tableams, needing different kinds of slots.

In passing also fix ExecOnConflictUpdate to clear the existing slot at
exit. Otherwise that slot could continue to hold a pin till the query
ends, which could be far too long if the input data set is large, and
there's no further conflicts. While previously also problematic, it's
now more important as there will be more such slots when partitioned.

Author: Andres Freund
Reviewed-By: Robert Haas, David Rowley
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de

In a complete brown paper bag moment, I forgot to include equalfuncs
in my previous fix of copy/out/readfuncs.  Thanks Tom for noticing.

Discussion: https://postgr.es/m/1659.1551903210@sss.pgh.pa.us

This will stop logging cases where, for example, a monitor opens a
connection and immediately closes it. If the packet contains any data an
incomplete packet will still be logged.

Author: Tom Lane

Discussion: https://postgr.es/m/a1379a72-2958-1ed0-ef51-09a21219b155@2ndQuadrant.com

This includes a catversion bump, as IntoClause is theoretically
speaking part of storable rules. In practice I don't think that can
happen, but there's no reason to be stingy here.

Per buildfarm member calliphoridae.

Per buildfarm.  This time I hopefully actually made sure to get all
the cases...