Now that spinlocks (hopefully!) act as compiler barriers, as of commit
0709b7ee, this should be safe.  This
serves as a demonstration of the new coding style, and may be optimized
better on some machines as well.

It is meaningless to declare a pass-by-value return type const.

It's a string, not a scalar.

Petr Jelinek

I missed this in 3bdcf6a5.

Noticed by Merlin Moncure
Discussion: CAHyXU0yC7uPeeVzQROwtnrOP9dxTEUPYjB0og4qUnbipMEV57w@mail.gmail.com

There are four weaknesses in728f152e:

* append_init() in heapdesc.c was ugly and required that rm_identify
  return values are only valid till the next call. Instead just add a
  couple more switch() cases for the INIT_PAGE cases. Now the returned
  value will always be valid.
* a couple rm_identify() callbacks missed masking xl_info with
  ~XLR_INFO_MASK.
* pg_xlogdump didn't map a NULL rm_identify to UNKNOWN or a similar
  string.
* append_init() was called when id=NULL - which should never actually
  happen. But it's better to be careful.

This has been broken since commit af7914c6,
which added the EXPLAIN (TIMING) option.  Although that commit included
updates to auto_explain, they evidently weren't tested very carefully,
because the code failed to print node timings even when it should, due to
failure to set es.timing in the ExplainState struct.  Reported off-list by
Neelakanth Nadgir of Salesforce.

In passing, clean up the documentation for auto_explain's options a
little bit, including re-ordering them into what seems to me a more
logical order.

The documentation overall is not entirely consistent about how we do
this, but this is consistent with other usages within lock.sgml.

Etsuro Fujita

Testing reveals that that doing a memcmp() before the strcoll() costs
practically nothing, at least on the systems we tested, and it speeds
up sorts containing many equal strings significatly.

Peter Geoghegan.  Review by myself and Heikki Linnakangas.  Comments
rewritten by me.

Building on the updatable security-barrier views work, add the
ability to define policies on tables to limit the set of rows
which are returned from a query and which are allowed to be added
to a table.  Expressions defined by the policy for filtering are
added to the security barrier quals of the query, while expressions
defined to check records being added to a table are added to the
with-check options of the query.

New top-level commands are CREATE/ALTER/DROP POLICY and are
controlled by the table owner.  Row Security is able to be enabled
and disabled by the owner on a per-table basis using
ALTER TABLE .. ENABLE/DISABLE ROW SECURITY.

Per discussion, ROW SECURITY is disabled on tables by default and
must be enabled for policies on the table to be used.  If no
policies exist on a table with ROW SECURITY enabled, a default-deny
policy is used and no records will be visible.

By default, row security is applied at all times except for the
table owner and the superuser.  A new GUC, row_security, is added
which can be set to ON, OFF, or FORCE.  When set to FORCE, row
security will be applied even for the table owner and superusers.
When set to OFF, row security will be disabled when allowed and an
error will be thrown if the user does not have rights to bypass row
security.

Per discussion, pg_dump sets row_security = OFF by default to ensure
that exports and backups will have all data in the table or will
error if there are insufficient privileges to bypass row security.
A new option has been added to pg_dump, --enable-row-security, to
ask pg_dump to export with row security enabled.

A new role capability, BYPASSRLS, which can only be set by the
superuser, is added to allow other users to be able to bypass row
security using row_security = OFF.

Many thanks to the various individuals who have helped with the
design, particularly Robert Haas for his feedback.

Authors include Craig Ringer, KaiGai Kohei, Adam Brightwell, Dean
Rasheed, with additional changes and rework by me.

Reviewers have included all of the above, Greg Smith,
Jeff McCormick, and Robert Haas.

x86's memory barrier assembly was marked as clobbering "memory" but
not "cc" even though 'addl' sets various flags. As it turns out gcc on
x86 implicitly assumes "cc" on every inline assembler statement, so
it's not a bug. But as that's poorly documented and might get copied
to architectures or compilers where that's not the case, it seems
better to be precise.

Discussion: 20140919100016.GH4277@alap3.anarazel.de

To keep the code common, backpatch to 9.2 where explicit memory
barriers were introduced.

This was introduced in 51bb7956.

The new --stats/--stats=record options to pg_xlogdump display per
rmgr/per record statistics about the parsed WAL. This is useful to
understand what the WAL primarily consists of, to allow targeted
optimizations on application, configuration, and core code level.

It is likely that we will want to fine tune the statistics further,
but the feature already is quite helpful.

Author: Abhijit Menon-Sen, slightly editorialized by me
Reviewed-By: Andres Freund, Dilip Kumar and Furuya Osamu
Discussion: 20140604104716.GA3989@toroid.org

This is primarily useful for the upcoming pg_xlogdump --stats feature,
but also allows to remove some duplicated code in the rmgr_desc
routines.

Due to the separation and harmonization, the output of dipsplayed
records changes somewhat. But since this isn't enduser oriented
content that's ok.

It's potentially desirable to further change pg_xlogdump's display of
records. It previously wasn't possible to show the record type
separately from the description forcing it to be in the last
column. But that's better done in a separate commit.

Author: Abhijit Menon-Sen, slightly editorialized by me
Reviewed-By: Álvaro Herrera, Andres Freund, and Heikki Linnakangas
Discussion: 20140604104716.GA3989@toroid.org

The PGAC_FUNC_SNPRINTF_SIZE_T_SUPPORT test was broken by
ce486056. Among others it made the UINT64_FORMAT macro to be
defined in c.h, instead of directly being defined by configure.

This lead to the replacement printf being used on all platforms for a
while. Which seems to work, because this was only used due to
different profiles ;)

Fix by relying on INT64_MODIFIER instead.

Add some quotes in the makefile snippet that creates the temporary
installation, so that it can handle spaces in the directory name and
possibly some other oddities.

They were marked to return a boolean, but they actually return a
GinTernaryValue, which is more like a "char". It makes no practical
difference, as the triConsistent functions cannot be called directly from
SQL because they have "internal" arguments, but this nevertheless seems
more correct.

Also fix the GinTernaryValue name in the documentation. I renamed the enum
earlier, but neglected the docs.

Alexander Korotkov. This is new in 9.4, so backpatch there.

The RFCs say that the CN must not be checked if a subjectAltName extension
of type dNSName is present. IOW, if subjectAltName extension is present,
but there are no dNSNames, we can still check the CN.

Alexey Klyukin

Pointers are all the same size, so it makes no practical difference, but
let's be tidy.

Found by Coverity, noted off-list by Tom Lane.

This new GUC context option allows GUC parameters to have the combined
properties of PGC_BACKEND and PGC_SUSET, ie, they don't change after
session start and non-superusers can't change them.  This is a more
appropriate choice for log_connections and log_disconnections than their
previous context of PGC_BACKEND, because we don't want non-superusers
to be able to affect whether their sessions get logged.

Note: the behavior for log_connections is still a bit odd, in that when
a superuser attempts to set it from PGOPTIONS, the setting takes effect
but it's too late to enable or suppress connection startup logging.
It's debatable whether that's worth fixing, and in any case there is
a reasonable argument for PGC_SU_BACKEND to exist.

In passing, re-pgindent the files touched by this commit.

Fujii Masao, reviewed by Joe Conway and Amit Kapila

Instead of just erroring out when a tool is missing, wrap the call with
the "missing" script that we are already using for bison, flex, and
perl, so that the users get a useful error message.

This behavior was made more precise in commit
11d205e2.

Renaming will have to be more comprehensive, so I need approval.

Since this makes the bucket headers use ~10x as much memory, properly
account for that memory when we figure out whether everything fits
in work_mem.  This might result in some cases that previously used
only a single batch getting split into multiple batches, but it's
unclear as yet whether we need defenses against that case, and if so,
what the shape of those defenses should be.

It's worth noting that even in these edge cases, users should still be
no worse off than they would have been last week, because commit
45f6240a saved a big pile of memory
on exactly the same workloads.

Tomas Vondra, reviewed and somewhat revised by me.

Previously replication commands like IDENTIFY_COMMAND were not logged
even when log_statements is set to all. Some users who want to audit
all types of statements were not satisfied with this situation. To
address the problem, this commit adds new GUC log_replication_commands.
If it's enabled, all replication commands are logged in the server log.

There are many ways to allow us to enable that logging. For example,
we can extend log_statement so that replication commands are logged
when it's set to all. But per discussion in the community, we reached
the consensus to add separate GUC for that.

Reviewed by Ian Barwick, Robert Haas and Heikki Linnakangas.

With the unicode linestyle, this adds support to control if the
column, header, or border style should be single or double line
unicode characters.  The default remains 'single'.

In passing, clean up the border documentation and address some
minor formatting/spelling issues.

Pavel Stehule, with some additional changes by me.

In psql, expanded mode was not being displayed correctly when using
the normal ascii or unicode linestyles and border set to '3'.  Now,
per the documentation, border '3' is really only sensible for HTML
and LaTeX formats, however, that's no excuse for ascii/unicode to
break in that case, and provisions had been made for psql to cleanly
handle this case (and it did, in non-expanded mode).

This was broken when ascii/unicode was initially added a good five
years ago because print_aligned_vertical_line wasn't passed in the
border setting being used by print_aligned_vertical but instead was
given the whole printTableContent.  There really isn't a good reason
for vertical_line to have the entire printTableContent structure, so
just pass in the printTextFormat and border setting (similar to how
this is handled in horizontal_line).

Pointed out by Pavel Stehule, fix by me.

Back-patch to all currently-supported versions.

This patch makes libpq check the server's hostname against DNS names listed
in the X509 subjectAltName extension field in the server certificate. This
allows the same certificate to be used for multiple domain names. If there
are no SANs in the certificate, the Common Name field is used, like before
this patch. If both are given, the Common Name is ignored. That is a bit
surprising, but that's the behavior mandated by the relevant RFCs, and it's
also what the common web browsers do.

This also adds a libpq_ngettext helper macro to allow plural messages to be
translated in libpq. Apparently this happened to be the first plural message
in libpq, so it was not needed before.

Alexey Klyukin, with some kibitzing by me.

The code that tried to split a page at 75/25 ratio, when appending to the
end of an index, was buggy in two ways. First, there was a silly typo that
caused it to just fill the left page as full as possible. But the logic as
it was intended wasn't correct either, and would actually have given a ratio
closer to 60/40 than 75/25.

Gaetano Mendola spotted the typo. Backpatch to 9.4, where this code was added.

The code for raising a NUMERIC value to an integer power wasn't very
careful about large powers.  It got an outright wrong answer for an
exponent of INT_MIN, due to failure to consider overflow of the Abs(exp)
operation; which is fixable by using an unsigned rather than signed
exponent value after that point.  Also, even though the number of
iterations of the power-computation loop is pretty limited, it's easy for
the repeated squarings to result in ridiculously enormous intermediate
values, which can take unreasonable amounts of time/memory to process,
or even overflow the internal "weight" field and so produce a wrong answer.
We can forestall misbehaviors of that sort by bailing out as soon as the
weight value exceeds what will fit in int16, since then the final answer
must overflow (if exp > 0) or underflow (if exp < 0) the packed numeric
format.

Per off-list report from Pavel Stehule.  Back-patch to all supported
branches.

Commit 95d737ff neglected to update
expected/json_1.out.  Per buildfarm.

When running vacuumdb --analyze-in-stages --all, it needs to run the
first stage across all databases before the second one, instead of
running all stages in a database before processing the next one.

Also respect the --quiet option with --analyze-in-stages.

Provide an option to skip NULL values in a row when generating a JSON
object from that row with row_to_json.  This can reduce the size of the
JSON object in cases where columns are NULL without really reducing the
information in the JSON object.

This also makes row_to_json into a single function with default values,
rather than having multiple functions.  In passing, change array_to_json
to also be a single function with default values (we don't add an
'ignore_nulls' option yet- it's not clear that there is a sensible
use-case there, and it hasn't been asked for in any case).

Pavel Stehule

With the new B-tree incomplete split handling in 9.4, _bt_insert_parent is
never called in recovery.

This improves the wording of commit 84aa8ba1.

Report by Kevin Grittner

Yet another silly mistake in 0709b7ee,
again found by buildfarm member castoroides.

I renamed a variable, but missed an #ifdef WIN32 block.

David Rowley.

The previous coding first generated a uniform random value between 0.0 and
1.0, then converted that to an integer between 1 and 10000, and divided that
again by 10000. Those conversions are unnecessary; we can use the double
value that pg_erand48() returns directly. While we're at it, put the logic
into a helper function, getPoissonRand().

The largest delay generated by the old coding was about 9.2 times the
average, because of the way the uniformly distributed value used for the
calculation was truncated to 1/10000 granularity. The new coding doesn't
have such clamping. With my laptop's DBL_MIN value, the maximum delay with
the new coding is about 700x the average. That seems acceptable - any
reasonable pgbench session should last long enough to average that out.

Backpatch to 9.4.