Commit Graph

11894 Commits

Author SHA1 Message Date
Peter Eisentraut 5d93ce2d0c doc: Check DocBook XML validity during the build
Building the documentation with XSLT does not check the DTD, like a
DSSSL build would.  One can often get away with having invalid XML, but
the stylesheets might then create incorrect output, as they are not
designed to handle that.  Therefore, check the validity of the XML
against the DTD, using xmllint, during the build.

Add xmllint detection to configure, and add some documentation.

xmllint comes with libxml2, which is already in use, but it might be in
a separate package, such as libxml2-utils on Debian.

Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
2014-10-21 14:46:38 -04:00
Peter Eisentraut f43afbca70 doc: Update Red Hat documentation tools information
The old text was written in ancient times when RPM packages could be
shared more or less freely across a plethora of RPM-based Linux
distributions.  This isn't really the case anymore, so just make this
information more concrete for the Red Hat family.
2014-10-21 10:43:09 -04:00
Peter Eisentraut f048e50037 doc: Update FreeBSD documentation tools information
based on patch from Dag-Erling Smørgrav <des@des.no>
2014-10-21 10:35:58 -04:00
Peter Eisentraut 7feaccc217 Allow setting effective_io_concurrency even on unsupported systems
This matches the behavior of other parameters that are unsupported on
some systems (e.g., ssl).

Also document the default value.
2014-10-18 21:35:46 -04:00
Bruce Momjian b87671f1b6 Shorten warning about hash creation
Also document that PITR is also affected.
2014-10-18 10:36:09 -04:00
Bruce Momjian 97d554871c doc: restrictions on alter database moving default tablespace
Mention tablespace must be empty and no one connected to the database.

Report by Josh Berkus
2014-10-18 10:23:42 -04:00
Peter Eisentraut 52c1ae22d6 doc: Clean up pg_recvlogical reference page
This needed a general cleanup of wording, typos, outdated terminology,
formatting, and hard-to-understand and borderline incorrect information.

Also tweak the pg_receivexlog page a bit to make the two more
consistent.
2014-10-18 09:26:36 -04:00
Tom Lane b2cbced9ee Support timezone abbreviations that sometimes change.
Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time.  But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation.  Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.

To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone.  For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time.  However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.

The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970.  The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.

While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.

This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib.  Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.

This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time.  We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.

In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
2014-10-16 15:22:10 -04:00
Tom Lane 90063a7612 Print planning time only in EXPLAIN ANALYZE, not plain EXPLAIN.
We've gotten enough push-back on that change to make it clear that it
wasn't an especially good idea to do it like that.  Revert plain EXPLAIN
to its previous behavior, but keep the extra output in EXPLAIN ANALYZE.
Per discussion.

Internally, I set this up as a separate flag ExplainState.summary that
controls printing of planning time and execution time.  For now it's
just copied from the ANALYZE option, but we could consider exposing it
to users.
2014-10-15 18:50:13 -04:00
Heikki Linnakangas 0ff5047d52 Fix typo in docs.
Shigeru Hanada
2014-10-14 09:45:33 +03:00
Peter Eisentraut db75e52485 doc: Improve ALTER VIEW / SET documentation
The way the ALTER VIEW / SET options were listed in the synopsis was
very confusing.  Move the list to the main description, similar to how
the ALTER TABLE reference page does it.
2014-10-13 22:22:20 -04:00
Peter Eisentraut 5dc4b50b02 doc: Fix copy-and-paste mistakes 2014-10-13 22:22:20 -04:00
Bruce Momjian 8660b40d0c doc: mention TM is ignored for to_date/to_timestamp()
Report by Goulven Guillard
2014-10-13 17:36:50 -04:00
Bruce Momjian ebd33f27ab doc: mention more changes needed to use huge pages
Report by Laurence Parry
2014-10-13 17:23:36 -04:00
Bruce Momjian 7ab96d18f9 docs: error for adding _validated_ domains for existing uses
Report by David G Johnston
2014-10-13 16:44:20 -04:00
Bruce Momjian 032f3b7e16 doc: improve USING and NATURAL JOIN descriptions
Patch by David G Johnston
2014-10-13 15:39:52 -04:00
Heikki Linnakangas 98aed6c721 Add --latency-limit option to pgbench.
This allows transactions that take longer than specified limit to be counted
separately. With --rate, transactions that are already late by the time we
get to execute them are skipped altogether. Using --latency-limit with
--rate allows you to "catch up" more quickly, if there's a hickup in the
server causing a lot of transactions to stall momentarily.

Fabien COELHO, reviewed by Rukh Meski and heavily refactored by me.
2014-10-13 20:50:24 +03:00
Bruce Momjian 80e6af1272 docs: remove mention that attnotnull should be changed
Report by Andres Freund
2014-10-11 17:23:57 -04:00
Tom Lane 25ad5a5284 Improve documentation about JSONB array containment behavior.
Per gripe from Josh Berkus.
2014-10-11 14:29:51 -04:00
Fujii Masao f19f0ee716 Fix broken example in PL/pgSQL document.
Back-patch to all supported branches.

Marti Raudsepp, per a report from Marko Tiikkaja
2014-10-10 03:18:01 +09:00
Alvaro Herrera df630b0dd5 Implement SKIP LOCKED for row-level locks
This clause changes the behavior of SELECT locking clauses in the
presence of locked rows: instead of causing a process to block waiting
for the locks held by other processes (or raise an error, with NOWAIT),
SKIP LOCKED makes the new reader skip over such rows.  While this is not
appropriate behavior for general purposes, there are some cases in which
it is useful, such as queue-like tables.

Catalog version bumped because this patch changes the representation of
stored rules.

Reviewed by Craig Ringer (based on a previous attempt at an
implementation by Simon Riggs, who also provided input on the syntax
used in the current patch), David Rowley, and Álvaro Herrera.

Author: Thomas Munro
2014-10-07 17:23:34 -03:00
Andres Freund d9f38c7a55 Add support for managing physical replication slots to pg_receivexlog.
pg_receivexlog already has the capability to use a replication slot to
reserve WAL on the upstream node. But the used slot currently has to
be created via SQL.

To allow using slots directly, without involving SQL, add
--create-slot and --drop-slot actions, analogous to the logical slot
manipulation support in pg_recvlogical.

Author: Michael Paquier
Discussion: CABUevEx+zrOHZOQg+dPapNPFRJdsk59b=TSVf30Z71GnFXhQaw@mail.gmail.com
2014-10-06 12:51:37 +02:00
Andres Freund c8b6cba84a Rename pg_recvlogical's --create/--drop to --create-slot/--drop-slot.
A future patch (9.5 only) adds slot management to pg_receivexlog. The
verbs create/drop don't seem descriptive enough there. It seems better
to rename pg_recvlogical's commands now, in beta, than live with the
inconsistency forever.

The old form (e.g. --drop) will still be accepted by virtue of most
getopt_long() options accepting abbreviations for long commands.

Backpatch to 9.4 where pg_recvlogical was introduced.

Author: Michael Paquier and Andres Freund
Discussion: CAB7nPqQtt79U6FmhwvgqJmNyWcVCbbV-nS72j_jyPEopERg9rg@mail.gmail.com
2014-10-06 12:11:52 +02:00
Tom Lane f706f2c1a0 Update 9.4 release notes for commits through today.
Add entries for recent changes, including noting the JSONB format change
and the recent timezone data changes.  We should remove those two items
before 9.4 final: the JSONB change will be of no interest in the long
run, and it's not normally our habit to mention timezone updates in
major-release notes.  But it seems important to document them temporarily
for beta testers.

I failed to resist the temptation to wordsmith a couple of existing
entries, too.
2014-10-05 14:14:04 -04:00
Stephen Frost 78d72563ef Fix CreatePolicy, pg_dump -v; psql and doc updates
Peter G pointed out that valgrind was, rightfully, complaining about
CreatePolicy() ending up copying beyond the end of the parsed policy
name.  Name is a fixed-size type and we need to use namein (through
DirectFunctionCall1()) to flush out the entire array before we pass
it down to heap_form_tuple.

Michael Paquier pointed out that pg_dump --verbose was missing a
newline and Fabrízio de Royes Mello further pointed out that the
schema was also missing from the messages, so fix those also.

Also, based on an off-list comment from Kevin, rework the psql \d
output to facilitate copy/pasting into a new CREATE or ALTER POLICY
command.

Lastly, improve the pg_policies view and update the documentation for
it, along with a few other minor doc corrections based on an off-list
discussion with Adam Brightwell.
2014-10-03 16:31:53 -04:00
Alvaro Herrera 1021bd6a89 Don't balance vacuum cost delay when per-table settings are in effect
When there are cost-delay-related storage options set for a table,
trying to make that table participate in the autovacuum cost-limit
balancing algorithm produces undesirable results: instead of using the
configured values, the global values are always used,
as illustrated by Mark Kirkwood in
http://www.postgresql.org/message-id/52FACF15.8020507@catalyst.net.nz

Since the mechanism is already complicated, just disable it for those
cases rather than trying to make it cope.  There are undesirable
side-effects from this too, namely that the total I/O impact on the
system will be higher whenever such tables are vacuumed.  However, this
is seen as less harmful than slowing down vacuum, because that would
cause bloat to accumulate.  Anyway, in the new system it is possible to
tweak options to get the precise behavior one wants, whereas with the
previous system one was simply hosed.

This has been broken forever, so backpatch to all supported branches.
This might affect systems where cost_limit and cost_delay have been set
for individual tables.
2014-10-03 13:01:27 -03:00
Heikki Linnakangas 7a08e21f35 Fix documentation for CREATE SEQUENCE IF NOT EXISTS.
The [ IF NOT EXISTS ] was put in wrong place in the syntax.

Pointed out by Marti Raudsepp.
2014-10-03 10:25:48 +03:00
Heikki Linnakangas 32984d8fc3 Add functions for dealing with PGP armor header lines to pgcrypto.
This add a new pgp_armor_headers function to extract armor headers from an
ASCII-armored blob, and a new overloaded variant of the armor function, for
constructing an ASCII-armor with extra headers.

Marko Tiikkaja and me.
2014-10-01 16:03:39 +03:00
Andres Freund 0ef3c29a4b Improve documentation about binary/textual output mode for output plugins.
Also improve related error message as it contributed to the confusion.

Discussion: CAB7nPqQrqFzjqCjxu4GZzTrD9kpj6HMn9G5aOOMwt1WZ8NfqeA@mail.gmail.com,
    CAB7nPqQXc_+g95zWnqaa=mVQ4d3BVRs6T41frcEYi2ocUrR3+A@mail.gmail.com

Per discussion between Michael Paquier, Robert Haas and Andres Freund

Backpatch to 9.4 where logical decoding was introduced.
2014-10-01 13:22:17 +02:00
Stephen Frost 8492d86342 Correct stdin/stdout usage in COPY .. PROGRAM
The COPY documentation incorrectly stated, for the PROGRAM case,
that we read from stdin and wrote to stdout.  Fix that, and improve
consistency by referring to the 'PostgreSQL' user instead of the
'postgres' user, as is done in the rest of the COPY documentation.

Pointed out by Peter van Dijk.

Back-patch to 9.3 where COPY .. PROGRAM was introduced.
2014-09-30 15:55:28 -04:00
Andres Freund 445d262852 doc fix for pg_recvlogical: --create doesn't immediately exit.
Author: Michael Paquier
2014-09-30 01:49:25 +02:00
Stephen Frost c8a026e4f1 Revert 95d737ff to add 'ignore_nulls'
Per discussion, revert the commit which added 'ignore_nulls' to
row_to_json.  This capability would be better added as an independent
function rather than being bolted on to row_to_json.  Additionally,
the implementation didn't address complex JSON objects, and so was
incomplete anyway.

Pointed out by Tom and discussed with Andrew and Robert.
2014-09-29 13:32:22 -04:00
Stephen Frost ff27fcfa0a Fix relcache for policies, and doc updates
Andres pointed out that there was an extra ';' in equalPolicies, which
made me realize that my prior testing with CLOBBER_CACHE_ALWAYS was
insufficient (it didn't always catch the issue, just most of the time).
Thanks to that, a different issue was discovered, specifically in
equalRSDescs.  This change corrects eqaulRSDescs to return 'true' once
all policies have been confirmed logically identical.  After stepping
through both functions to ensure correct behavior, I ran this for
about 12 hours of CLOBBER_CACHE_ALWAYS runs of the regression tests
with no failures.

In addition, correct a few typos in the documentation which were pointed
out by Thom Brown (thanks!) and improve the policy documentation further
by adding a flushed out usage example based on a unix passwd file.

Lastly, clean up a few comments in the regression tests and pg_dump.h.
2014-09-26 12:46:26 -04:00
Heikki Linnakangas b0d81adea6 Add -D option to specify data directory to pg_controldata and pg_resetxlog.
It was confusing that to other commands, like initdb and postgres, you would
pass the data directory with "-D datadir", but pg_controldata and
pg_resetxlog would take just plain path, without the "-D". With this patch,
pg_controldata and pg_resetxlog also accept "-D datadir".

Abhijit Menon-Sen, with minor kibitzing by me
2014-09-25 13:37:19 +03:00
Stephen Frost afd1d95f5b Copy-editing of row security
Address a few typos in the row security update, pointed out
off-list by Adam Brightwell.  Also include 'ALL' in the list
of commands supported, for completeness.
2014-09-24 17:45:11 -04:00
Stephen Frost 6550b901fe Code review for row security.
Buildfarm member tick identified an issue where the policies in the
relcache for a relation were were being replaced underneath a running
query, leading to segfaults while processing the policies to be added
to a query.  Similar to how TupleDesc RuleLocks are handled, add in a
equalRSDesc() function to check if the policies have actually changed
and, if not, swap back the rsdesc field (using the original instead of
the temporairly built one; the whole structure is swapped and then
specific fields swapped back).  This now passes a CLOBBER_CACHE_ALWAYS
for me and should resolve the buildfarm error.

In addition to addressing this, add a new chapter in Data Definition
under Privileges which explains row security and provides examples of
its usage, change \d to always list policies (even if row security is
disabled- but note that it is disabled, or enabled with no policies),
rework check_role_for_policy (it really didn't need the entire policy,
but it did need to be using has_privs_of_role()), and change the field
in pg_class to relrowsecurity from relhasrowsecurity, based on
Heikki's suggestion.  Also from Heikki, only issue SET ROW_SECURITY in
pg_restore when talking to a 9.5+ server, list Bypass RLS in \du, and
document --enable-row-security options for pg_dump and pg_restore.

Lastly, fix a number of minor whitespace and typo issues from Heikki,
Dimitri, add a missing #include, per Peter E, fix a few minor
variable-assigned-but-not-used and resource leak issues from Coverity
and add tab completion for role attribute bypassrls as well.
2014-09-24 16:32:22 -04:00
Tom Lane 898f8a96ef Fix failure of contrib/auto_explain to print per-node timing information.
This has been broken since commit af7914c662,
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.
2014-09-19 13:19:27 -04:00
Robert Haas a92b5f969b doc: Use <literal> and all-caps for READ COMMITTED isolation level.
The documentation overall is not entirely consistent about how we do
this, but this is consistent with other usages within lock.sgml.

Etsuro Fujita
2014-09-19 13:12:52 -04:00
Stephen Frost 491c029dbc Row-Level Security Policies (RLS)
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.
2014-09-19 11:18:35 -04:00
Andres Freund bdd5726c34 Add the capability to display summary statistics to pg_xlogdump.
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
2014-09-19 16:33:16 +02:00
Heikki Linnakangas 77e65bf369 Fix the return type of GIN triConsistent support functions to "char".
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.
2014-09-16 09:22:33 +03:00
Tom Lane fe550b2ac2 Invent PGC_SU_BACKEND and mark log_connections/log_disconnections that way.
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
2014-09-13 21:01:57 -04:00
Peter Eisentraut c2a01439c0 Run missing documentation tools through "missing"
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.
2014-09-13 20:22:21 -04:00
Fujii Masao 4ad2a54805 Add GUC to enable logging of replication commands.
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.
2014-09-13 02:55:45 +09:00
Stephen Frost a2dabf0e1d Add unicode_{column|header|border}_style to psql
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.
2014-09-12 12:04:37 -04:00
Stephen Frost 95d737ff45 Add 'ignore_nulls' option to row_to_json
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
2014-09-11 21:23:51 -04:00
Heikki Linnakangas 02e3bcc661 Change the way latency is calculated with pgbench --rate option.
The reported latency values now include the "schedule lag" time, that is,
the time between the transaction's scheduled start time and the time it
actually started. This relates better to a model where requests arrive at a
certain rate, and we are interested in the response time to the end user or
application, rather than the response time of the database itself.

Also, when --rate is used, include the schedule lag time in the log output.

The --rate option is new in 9.4, so backpatch to 9.4. It seems better to
make this change in 9.4, while we're still in the beta period, than ship a
9.4 version that calculates the values differently than 9.5.
2014-09-11 12:57:32 +03:00
Bruce Momjian 4c4654afeb doc: improve configuration management section
Patch by David Johnston

Backpatch through 9.4
2014-09-10 20:50:15 -04:00
Bruce Momjian 36ad1a87a3 Implement mxid_age() to compute multi-xid age
Report by Josh Berkus
2014-09-10 17:13:04 -04:00
Andres Freund 07c8651dd9 Add new psql help topics, accessible to both --help and \?.
Add --help=<topic> for the commandline, and \? <topic> as a backslash
command, to show more help than the invocations without parameters
do. "commands", "variables" and "options" currently exist as help
topics describing, respectively, backslash commands, psql variables,
and commandline switches. Without parameters the help commands show
their previous topic.

Some further wordsmithing or extending of the added help content might
be needed; but there seems little benefit delaying the overall feature
further.

Author: Pavel Stehule, editorialized by many

Reviewed-By: Andres Freund, Petr Jelinek, Fujii Masao, MauMau, Abhijit
    Menon-Sen and Erik Rijkers.

Discussion: CAFj8pRDVGuC-nXBfe2CK8vpyzd2Dsr9GVpbrATAnZO=2YQ0s2Q@mail.gmail.com,
    CAFj8pRA54AbTv2RXDTRxiAd8hy8wxmoVLqhJDRCwEnhdd7OUkw@mail.gmail.com
2014-09-10 00:08:56 +02:00