Last(?) round of changes for 10.0.

Buildfarm members skink and sungazer have both recently failed this
test, with symptoms indicating that the default 3-second timeout
isn't quite enough for those very slow systems.  There's no reason
to be miserly with this timeout, so boost it to 60 seconds.

Back-patch to all versions containing this test.  That may be overkill,
because the failure has only been observed in the v10 branch, but
I don't feel like having to revisit this later.

This contains all individuals mentioned in the commit messages during
PostgreSQL 10 development.

current through babf18579455e85269ad75e1ddb03f34138f77b6

Discussion: https://www.postgresql.org/message-id/flat/54ad0e42-770e-dfe1-123e-bce9361ad452%402ndquadrant.com

If --rate was used to throttle pgbench, it failed to sleep when it had
nothing to do, leading to a busy-wait with 100% CPU usage. This bug was
introduced in the refactoring in v10. Before that, sleep() was called with
a timeout, even when there were no file descriptors to wait for.

Reported by Jeff Janes, patch by Fabien COELHO. Backpatch to v10.

Discussion: https://www.postgresql.org/message-id/CAMkU%3D1x5hoX0pLLKPRnXCy0T8uHoDvXdq%2B7kAM9eoC9_z72ucw%40mail.gmail.com

During a binary upgrade, all type OIDs are supposed to be assigned by
pg_dump based on their values in the old cluster.  But now that domains
have arrays, there's nothing to base the arrays' type OIDs on, if we're
upgrading from a pre-v11 cluster.  Make pg_dump search for an unused type
OID to use for this purpose.  Per buildfarm.

Discussion: https://postgr.es/m/E1dyLlE-0002gT-H5@gemulon.postgresql.org

Allowing arrays with a domain type as their element type was left un-done
in the original domain patch, but not for any very good reason.  This
omission leads to such surprising results as array_agg() not working on
a domain column, because the parser can't identify a suitable output type
for the polymorphic aggregate.

In order to fix this, first clean up the APIs of coerce_to_domain() and
some internal functions in parse_coerce.c so that we consistently pass
around a CoercionContext along with CoercionForm.  Previously, we sometimes
passed an "isExplicit" boolean flag instead, which is strictly less
information; and coerce_to_domain() didn't even get that, but instead had
to reverse-engineer isExplicit from CoercionForm.  That's contrary to the
documentation in primnodes.h that says that CoercionForm only affects
display and not semantics.  I don't think this change fixes any live bugs,
but it makes things more consistent.  The main reason for doing it though
is that now build_coercion_expression() receives ccontext, which it needs
in order to be able to recursively invoke coerce_to_target_type().

Next, reimplement ArrayCoerceExpr so that the node does not directly know
any details of what has to be done to the individual array elements while
performing the array coercion.  Instead, the per-element processing is
represented by a sub-expression whose input is a source array element and
whose output is a target array element.  This simplifies life in
parse_coerce.c, because it can build that sub-expression by a recursive
invocation of coerce_to_target_type().  The executor now handles the
per-element processing as a compiled expression instead of hard-wired code.
The main advantage of this is that we can use a single ArrayCoerceExpr to
handle as many as three successive steps per element: base type conversion,
typmod coercion, and domain constraint checking.  The old code used two
stacked ArrayCoerceExprs to handle type + typmod coercion, which was pretty
inefficient, and adding yet another array deconstruction to do domain
constraint checking seemed very unappetizing.

In the case where we just need a single, very simple coercion function,
doing this straightforwardly leads to a noticeable increase in the
per-array-element runtime cost.  Hence, add an additional shortcut evalfunc
in execExprInterp.c that skips unnecessary overhead for that specific form
of expression.  The runtime speed of simple cases is within 1% or so of
where it was before, while cases that previously required two levels of
array processing are significantly faster.

Finally, create an implicit array type for every domain type, as we do for
base types, enums, etc.  Everything except the array-coercion case seems
to just work without further effort.

Tom Lane, reviewed by Andrew Dunstan

Discussion: https://postgr.es/m/9852.1499791473@sss.pgh.pa.us

Reported-By: Peter Geoghegan

Reported-By: Thomas Munro and Jesper Pedersen

Upcoming patches are going to address performance issues that involve
slow system provided ntohs/htons etc. To address that expand
pg_bswap.h to provide pg_ntoh{16,32,64}, pg_hton{16,32,64} and
optimize their respective implementations by using compiler intrinsics
for gcc compatible compilers and msvc. Fall back to manual
implementations using shifts etc otherwise.

Additionally remove multiple evaluation hazards from the existing
BSWAP32/64 macros, by replacing them with inline functions when
necessary. In the course of that the naming scheme is changed to
pg_bswap16/32/64.

Author: Andres Freund
Discussion: https://postgr.es/m/20170927172019.gheidqy6xvlxb325@alap3.anarazel.de

This is more idiomatic style and available as of Python 2.4, which is
our minimum.

get_rel_oids used to not take any relation locks at all, but that stopped
being a good idea with commit 3c3bb993, which inserted a syscache lookup
into the function.  A concurrent DROP TABLE could now produce "cache lookup
failed", which we don't want to have happen in normal operation.  The best
solution seems to be to transiently take a lock on the relation named by
the RangeVar (which also makes the result of RangeVarGetRelid a lot less
spongy).  But we shouldn't hold the lock beyond this function, because we
don't want VACUUM to lock more than one table at a time.  (That would not
be a big problem right now, but it will become one after the pending
feature patch to allow multiple tables to be named in VACUUM.)

In passing, adjust vacuum_rel and analyze_rel to document that we don't
trust the passed RangeVar to be accurate, and allow the RangeVar to
possibly be NULL --- which it is anyway for a whole-database VACUUM,
though we accidentally didn't crash for that case.

The passed RangeVar is in fact inaccurate when dealing with a child
partition, as of v10, and it has been wrong for a whole long time in the
case of vacuum_rel() recursing to a TOAST table.  None of these things
present visible bugs up to now, because the passed RangeVar is in fact
only consulted for autovacuum logging, and in that particular context it's
always accurate because autovacuum doesn't let vacuum.c expand partitions
nor recurse to toast tables.  Still, this seems like trouble waiting to
happen, so let's nail the door at least partly shut.  (Further cleanup
is planned, in HEAD only, as part of the pending feature patch.)

Fix some sadly inaccurate/obsolete comments too.  Back-patch to v10.

Michael Paquier and Tom Lane

Discussion: https://postgr.es/m/25023.1506107590@sss.pgh.pa.us

If \d rather than \d+ is used, then verbose is false and we don't ask
the server for the partition constraint; so we shouldn't print it in
that case either.

Maksim Milyutin, per a report from Jesper Pedersen.  Reviewed by
Jesper Pedersen and Amit Langote.

Discussion: http://postgr.es/m/2af5fc4d-7bcc-daa8-4fe6-86274bea363c@redhat.com

This beats the old behavior of busy-waiting hands down.

Oversight in commit 12788ae4.

Report by Pavan Deolasee. Patch by Fabien Coelho.  Reviewed by
Pavan Deolasee.

Discussion: http://postgr.es/m/CABOikdPhfXTypckMC1Ux6Ko+hKBWwUBA=EXsvamXYSg8M9J94w@mail.gmail.com

For \d sequencename, the psql code just did SELECT * FROM sequencename
to get the information to display, but this does not contain much
interesting information anymore in PostgreSQL 10, because the metadata
has been moved to a separate system catalog.

This patch creates a newly designed sequence display that is not merely
an extension of the general relation/table display as it was previously.

Example:

PostgreSQL 9.6:

=> \d foobar
           Sequence "public.foobar"
    Column     |  Type   |        Value
---------------+---------+---------------------
 sequence_name | name    | foobar
 last_value    | bigint  | 1
 start_value   | bigint  | 1
 increment_by  | bigint  | 1
 max_value     | bigint  | 9223372036854775807
 min_value     | bigint  | 1
 cache_value   | bigint  | 1
 log_cnt       | bigint  | 0
 is_cycled     | boolean | f
 is_called     | boolean | f

PostgreSQL 10 before this change:

=> \d foobar
   Sequence "public.foobar"
   Column   |  Type   | Value
------------+---------+-------
 last_value | bigint  | 1
 log_cnt    | bigint  | 0
 is_called  | boolean | f

New:

=> \d foobar
                           Sequence "public.foobar"
  Type  | Start | Minimum |       Maximum       | Increment | Cycles? | Cache
--------+-------+---------+---------------------+-----------+---------+-------
 bigint |     1 |       1 | 9223372036854775807 |         1 | no      |     1
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>

Avoid the coding pattern "*op->resvalue = f();", as some compilers think
that requires them to evaluate "op->resvalue" before the function call.
Unless there are lots of free registers, this can lead to a useless
register spill and reload across the call.

I changed all the cases like this in ExecInterpExpr(), but didn't bother
in the out-of-line opcode eval subroutines, since those are presumably
not as performance-critical.

Discussion: https://postgr.es/m/2508.1506630094@sss.pgh.pa.us

Add bgw_type field to background worker structure.  It is intended to be
set to the same value for all workers of the same type, so they can be
grouped in pg_stat_activity, for example.

The backend_type column in pg_stat_activity now shows bgw_type for a
background worker.  The ps listing also no longer calls out that a
process is a background worker but just show the bgw_type.  That way,
being a background worker is more of an implementation detail now that
is not shown to the user.  However, most log messages still refer to
'background worker "%s"'; otherwise constructing sensible and
translatable log messages would become tricky.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>

At the time replacement_sort_tuples was introduced, there were still
cases where replacement selection sort noticeably outperformed using
quicksort even for the first run.  However, those cases seem to have
evaporated as a result of further improvements made since that time
(and perhaps also advances in CPU technology).  So remove replacement
selection and the controlling GUC entirely.  This makes tuplesort.c
noticeably simpler and probably paves the way for further
optimizations someone might want to do later.

Peter Geoghegan, with review and testing by Tomas Vondra and me.

Discussion: https://postgr.es/m/CAH2-WzmmNjG_K0R9nqYwMq3zjyJJK+hCbiZYNGhAy-Zyjs64GQ@mail.gmail.com

Also make overriding the title easier.  That helps telling where the
report came from and labeling different variants of a report.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

By just running lcov on the produced .gcda data files, we don't account
for source files that are not touched by tests at all.  To fix that, run
lcov --initial to create a base line info file with all zero counters,
and merge that with the actual counters when creating the final report.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

For XML compatibility, replace marked sections <![IGNORE[ ]]> with
comments <!-- -->.  In some cases it seemed better to remove the ignored
text altogether, and in one case the text should not have been ignored.

Vacuum calls page-level HOT prune to remove dead HOT tuples before doing
liveness checks (HeapTupleSatisfiesVacuum) on the remaining tuples.  But
concurrent transaction commit/abort may turn DEAD some of the HOT tuples
that survived the prune, before HeapTupleSatisfiesVacuum tests them.
This happens to activate the code that decides to freeze the tuple ...
which resuscitates it, duplicating data.

(This is especially bad if there's any unique constraints, because those
are now internally violated due to the duplicate entries, though you
won't know until you try to REINDEX or dump/restore the table.)

One possible fix would be to simply skip doing anything to the tuple,
and hope that the next HOT prune would remove it.  But there is a
problem: if the tuple is older than freeze horizon, this would leave an
unfrozen XID behind, and if no HOT prune happens to clean it up before
the containing pg_clog segment is truncated away, it'd later cause an
error when the XID is looked up.

Fix the problem by having the tuple freezing routines cope with the
situation: don't freeze the tuple (and keep it dead).  In the cases that
the XID is older than the freeze age, set the HEAP_XMAX_COMMITTED flag
so that there is no need to look up the XID in pg_clog later on.

An isolation test is included, authored by Michael Paquier, loosely
based on Daniel Wood's original reproducer.  It only tests one
particular scenario, though, not all the possible ways for this problem
to surface; it be good to have a more reliable way to test this more
fully, but it'd require more work.
In message https://postgr.es/m/20170911140103.5akxptyrwgpc25bw@alvherre.pgsql
I outlined another test case (more closely matching Dan Wood's) that
exposed a few more ways for the problem to occur.

Backpatch all the way back to 9.3, where this problem was introduced by
multixact juggling.  In branches 9.3 and 9.4, this includes a backpatch
of commit e5ff9fefcd50 (of 9.5 era), since the original is not
correctable without matching the coding pattern in 9.5 up.

Reported-by: Daniel Wood
Diagnosed-by: Daniel Wood
Reviewed-by: Yi Wen Wong, Michaël Paquier
Discussion: https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.com

Call lcov with --no-external option to exclude external files (for
example, system headers with inline functions) from output.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

This is the way lcov was intended to be used.  It is much faster and
more robust and makes the makefiles simpler than running it in each
subdirectory.

The previous coding ran gcov before lcov, but that is useless because
lcov/geninfo call gcov internally and use that information.  Moreover,
this led to complications and failures during parallel make.  This
separates the two targets:  You either use "make coverage" to get
textual output from gcov or "make coverage-html" to get an HTML report
via lcov.  (Using both is still problematic because they write the same
output files.)
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

float8_numeric() and float4_numeric() failed to consider the possibility
that the input is an IEEE infinity.  The results depended on the
platform-specific behavior of sprintf(): on most platforms you'd get
something like

ERROR:  invalid input syntax for type numeric: "inf"

but at least on Windows it's possible for the conversion to succeed and
deliver a finite value (typically 1), due to a nonstandard output format
from sprintf and lack of syntax error checking in these functions.

Since our numeric type lacks the concept of infinity, a suitable conversion
is impossible; the best thing to do is throw an explicit error before
letting sprintf do its thing.

While at it, let's use snprintf not sprintf.  Overrunning the buffer
should be impossible if sprintf does what it's supposed to, but this
is cheap insurance against a stack smash if it doesn't.

Problem reported by Taiki Kondo.  Patch by me based on fix suggestion
from KaiGai Kohei.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/12A9442FBAE80D4E8953883E0B84E088C8C7A2@BPXM01GP.gisp.nec.co.jp

This reverts commit 15bc038f, along with the followon commits 1635e80d
and 984c9207 that tried to clean up the problems exposed by bug #14825.
The result was incomplete because it failed to address parallel-query
requirements.  With 10.0 release so close upon us, now does not seem like
the time to be adding more code to fix that.  I hope we can un-revert this
code and add the missing parallel query support during the v11 cycle.

Back-patch to v10.

Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org

The changes in 639928c9 turned out to
require Perl 5.9.3, which is newer than our minimum required version.
So revert back to the old code for the normal case and only use the new
variant when both coverage and vpath are used.  As the minimum Perl
version moves forward, we can drop the old code sometime.

Provide a correct description of how multiple policies are combined,
clarify when SELECT permissions are required, mention SELECT FOR
UPDATE/SHARE, and do some other more minor tidying up.

Reviewed by Stephen Frost

Discussion: https://postgr.es/m/CAEZATCVrxyYbOFU8XbGHicz%2BmXPYzw%3DhfNL2XTphDt-53TomQQ%40mail.gmail.com

Back-patch to 9.5.

Run xsubpp with the -output option instead of redirecting stdout.  That
ensures that the #line directives in the output file point to the right
place in a vpath build.  This in turn fixes an error in coverage builds
that it can't find the source files.

Refactor the makefile rules while we're here.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

Previously, we created a variant of the installation instructions for
producing the plain-text INSTALL file by marking up certain parts of
installation.sgml using SGML parameterized marked sections.  Marked
sections will not work anymore in XML, so before we can convert the
documentation to XML, we need a new approach.

DocBook provides a "profiling" feature that allows selecting content
based on attributes, which would work here.  But it imposes a noticeable
overhead when building the full documentation and causes complications
when building some output formats, and given that we recently spent a
fair amount of effort optimizing the documentation build time, it seems
sad to have to accept that.

So as an alternative, (1) we create our own mini-profiling layer that
adjusts just the text we want, and (2) assemble the pieces of content
that we want in the INSTALL file using XInclude.  That way, there is no
overhead when building the full documentation and most of the "ugly"
stuff in installation.sgml can be removed and dealt with out of line.

When requesting a particular replication slot, the new pg_basebackup
option -C/--create-slot creates it before starting to replicate from it.

Further refactor the slot creation logic to include the temporary slot
creation logic into the same function.  Add new arguments is_temporary
and preserve_wal to CreateReplicationSlot().  Print in --verbose mode
that a slot has been created.

Author: Michael Banck <michael.banck@credativ.de>

It drops objects outside information_schema that depend on objects
inside information_schema.  For example, it will drop a user-defined
view if the view query refers to information_schema.

Discussion: https://postgr.es/m/20170831025345.GE3963697@rfd.leadboat.com

Add some more tests for the --create-slot and --drop-slot options,
verifying that the right kind of slot was created and that the slot was
dropped.  While working on an unrelated patch for pg_basebackup, some of
this was temporarily broken without any tests noticing.

This is useful for example for the pg_basebackup and related tests.

Per suggestions from Peter Eisentraut and David Johnston.
Back-patch, like the previous commit.

Discussion: https://postgr.es/m/E1dv9jI-0006oT-Fn@gemulon.postgresql.org

posix_fallocate() is not quite a drop-in replacement for fallocate(),
because it is defined to return the error code as its function result,
not in "errno".  I (tgl) missed this because RHEL6's version seems
to set errno as well.  That is not the case on more modern Linuxen,
though, as per buildfarm results.

Aside from fixing the return-convention confusion, remove the test
for ENOSYS; we expect that glibc will mask that for posix_fallocate,
though it does not for fallocate.  Keep the test for EINTR, because
POSIX specifies that as a possible result, and buildfarm results
suggest that it can happen in practice.

Back-patch to 9.4, like the previous commit.

Thomas Munro

Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com

The blacklist mechanism added by the preceding commit directly fixes
most of the practical cases that the same-transaction test was meant
to cover.  What remains is use-cases like

	begin;
	create type e as enum('x');
	alter type e add value 'y';
	-- use 'y' somehow
	commit;

However, because the same-transaction test is heuristic, it fails on
small variants of that, such as renaming the type or changing its
owner.  Rather than try to explain the behavior to users, let's
remove it and just have a rule that the newly added value can't be
used before being committed, full stop.  Perhaps later it will be
worth the implementation effort and overhead to have a more accurate
test for type-was-created-in-this-transaction.  We'll wait for some
field experience with v10 before deciding to do that.

Back-patch to v10.

Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org

Commit 15bc038f allowed ALTER TYPE ADD VALUE to be executed inside
transaction blocks, by disallowing the use of the added value later
in the same transaction, except under limited circumstances.  However,
the test for "limited circumstances" was heuristic and could reject
references to enum values that were created during CREATE TYPE AS ENUM,
not just later.  This breaks the use-case of restoring pg_dump scripts
in a single transaction, as reported in bug #14825 from Balazs Szilfai.

We can improve this by keeping a "blacklist" table of enum value OIDs
created by ALTER TYPE ADD VALUE during the current transaction.  Any
visible-but-uncommitted value whose OID is not in the blacklist must
have been created by CREATE TYPE AS ENUM, and can be used safely
because it could not have a lifespan shorter than its parent enum type.

This change also removes the restriction that a renamed enum value
can't be used before being committed (unless it was on the blacklist).

Andrew Dunstan, with cosmetic improvements by me.
Back-patch to v10.

Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org

The --slot option somehow ended up under options controlling the output,
and some other options were in a nonsensical place or were not moved
after recent renamings, so tidy all that up a bit.

A FOR ALL TABLES publication naturally considers all base tables to be a
candidate for replication.  This includes transient heaps that are
created during a table rewrite during DDL.  This causes failures on the
subscriber side because it will not have a table like pg_temp_16386 to
receive data (and if it did, it would be the wrong table).

The prevent this problem, we filter out any tables that match this
naming pattern and match an actual table from FOR ALL TABLES
publications.  This is only a heuristic, meaning that user tables that
match that naming could accidentally be omitted.  A more robust solution
might require an explicit marking of such tables in pg_class somehow.
Reported-by: yxq <yxq@o2.pl>
Bug: #14785
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>

This was intended as infrastructure for weakening VACUUM's locking
requirements, similar to what was done for btree indexes in commit
2ed5b87f.  However, for hash indexes,
it seems that the improvements which are possible are actually
extremely marginal.  Furthermore, performing the LSN cross-check will
end up skipping cleanup far more often than is necessary; we only care
about page modifications due to a VACUUM, but the LSN check will fail
if ANY modification has occurred.  So, rather than pressing forward
with that "optimization", just rip the LSN field out.

Patch by me, reviewed by Ashutosh Sharma and Amit Kapila

Discussion: http://postgr.es/m/CAA4eK1JxqqcuC5Un7YLQVhOYSZBS+t=3xqZuEkt5RyquyuxpwQ@mail.gmail.com