Commit Graph

16202 Commits

Author SHA1 Message Date
Dean Rasheed a6864751cd Doc: Miscellaneous doc updates for MERGE.
Update a few places in the documentation that should mention MERGE
among the list of applicable commands. In a couple of places, a
slightly more detailed description of what happens for MERGE seems
appropriate.

Reviewed by Alvaro Herrera.

Discussion: http://postgr.es/m/CAEZATCWqHLcxab89ATMQZNGFG_mxDPM%2BjzkSbXKD3JYPfRGvtw%40mail.gmail.com
2023-02-26 09:04:04 +00:00
Dean Rasheed 576b25bfd0 Add missing support for the latest SPI status codes.
SPI_result_code_string() was missing support for SPI_OK_TD_REGISTER,
and in v15 and later, it was missing support for SPI_OK_MERGE, as was
pltcl_process_SPI_result().

The last of those would trigger an error if a MERGE was executed from
PL/Tcl. The others seem fairly innocuous, but worth fixing.

Back-patch to all supported branches. Before v15, this is just adding
SPI_OK_TD_REGISTER to SPI_result_code_string(), which is unlikely to
be seen by anyone, but seems worth doing for completeness.

Reviewed by Tom Lane.

Discussion:
  https://postgr.es/m/CAEZATCUg8V%2BK%2BGcafOPqymxk84Y_prXgfe64PDoopjLFH6Z0Aw%40mail.gmail.com
  https://postgr.es/m/CAEZATCUMe%2B_KedPMM9AxKqm%3DSZogSxjUcrMe%2BsakusZh3BFcQw%40mail.gmail.com
2023-02-22 13:24:51 +00:00
Tom Lane 2ee703c9d1 Stop recommending auto-download of DTD files, and indeed disable it.
It appears no longer possible to build the SGML docs without a local
installation of the DocBook DTD, because sourceforge.net now only
permits HTTPS access, and no common version of xsltproc supports that.
Hence, remove the bits of our documentation suggesting that that's
possible or useful.

In fact, we might as well add the --nonet option to the build recipes
automatically, for a bit of extra security.

Also fix our documentation-tool-installation recipes for macOS to
ensure that xmllint and xsltproc are pulled in from MacPorts or
Homebrew.  The previous recipes assumed you could use the
Apple-supplied versions of these tools; which still works, except that
you'd need to set an environment variable to ensure that they would
find DTD files provided by those package managers.  Simpler and easier
to just recommend pulling in the additional packages.

In HEAD, also document how to build docs using Meson, and adjust
"ninja docs" to just build the HTML docs, for consistency with the
default behavior of doc/src/sgml/Makefile.

In a fit of neatnik-ism, I also made the ordering of the package
lists match the order in which the tools are described at the head
of the appendix.

Aleksander Alekseev, Peter Eisentraut, Tom Lane

Discussion: https://postgr.es/m/CAJ7c6TO8Aro2nxg=EQsVGiSDe-TstP4EsSvDHd7DSRsP40PgGA@mail.gmail.com
2023-02-08 17:15:23 -05:00
Tom Lane 6788a55898 Last-minute updates for release notes.
Security: CVE-2022-41862
2023-02-06 11:43:10 -05:00
Tom Lane 80d43843e7 Release notes for 15.2, 14.7, 13.10, 12.14, 11.19. 2023-02-05 16:22:32 -05:00
Tom Lane f282b02678 First-draft release notes for 15.2.
As usual, the release notes for other branches will be made by cutting
these down, but put them up for community review first.
2023-02-03 14:30:49 -05:00
Peter Eisentraut e7c2e02a66 doc: Fix XML formatting that psql cannot handle
Breaking <phrase> over two lines is not handled by psql's
create_help.pl.  (It creates faulty \help output.)

Undo the formatting change introduced by
9bdad1b515 to fix this for now.
2023-02-03 09:07:53 +01:00
Thomas Munro d54e1fcaa5 Doc: Abstract AF_UNIX sockets don't work on Windows.
An early release of AF_UNIX in Windows apparently supported Linux-style
"abstract" Unix sockets, but they do not seem to work in current Windows
versions and there is no mention of any of this in the Winsock
documentation.  Remove the mention of Windows from the documentation.

Back-patch to 14, where commit c9f0624b landed.

Discussion: https://postgr.es/m/CA%2BhUKGKrYbSZhrk4NGfoQGT_3LQS5pC5KNE1g0tvE_pPBZ7uew%40mail.gmail.com
2023-02-02 18:26:36 +13:00
Tom Lane e4035a9ca4 Doc: clarify use of NULL to drop comments and security labels.
This was only mentioned in the description of the text/label, which
are marked as being in quotes in the synopsis, which can cause
confusion (as witnessed on IRC).

Also separate the literal and NULL cases in the parameter list, per
suggestion from Tom Lane.

Also add an example of dropping a security label.

Dagfinn Ilmari Mannsåker, with some tweaks by me

Discussion: https://postgr.es/m/87sffqk4zp.fsf@wibble.ilmari.org
2023-01-31 14:32:51 -05:00
Michael Paquier 88c27b8fe2 doc: Fix network_ops -> inet_ops in SpGiST operator class list
network_ops is an opclass family of SpGiST, and the opclass able to
work on the inet type is named inet_ops.

Oversight in 7a1cd52, that reworked the design of the table listing all
the operators available.

Reported-by: Laurence Parry
Reviewed-by: Tom Lane, David G. Johnston
Discussion: https://postgr.es/m/167458110639.2667300.14741268666497110766@wrigleys.postgresql.org
Backpatch-through: 14
2023-01-25 20:00:42 +09:00
Tatsuo Ishii 40015cf8ec Doc: fix typo in backup.sgml.
<varname>archive_command</varname> was unnecessarily repeated.

Author: Tatsuo Ishii
Reviewed-by: Amit Kapila
Backpatch-through: 15
Discussion: https://postgr.es/m/flat/20230114.110234.666053507266410467.t-ishii%40sranhm.sra.co.jp
2023-01-14 18:12:19 +09:00
Michael Paquier 93595ffd59 doc: Simplify description of functions for pg_walinspect
As introduced in 2258e76, the docs were hard to parse:
- The examples used listed a lot of long records, bloating the output.
These are switched to show less records with the expanded format,
similarly to pageinspect.
- The function descriptions listed all the OUT parameters, producing
long lines.  This is updated so as only the input parameters are
documented, clarifying the whole.
- Remove one example on pg_get_wal_stats() when per_record is set to
true, which is not really necessary once we know the output produced,
and the behavior of the parameter is documented.

While on it, fix a few grammar mistakes and simplify a couple of
sentences.

Author: Bharath Rupireddy
Discussion: https://postgr.es/m/CALj2ACVGcUpziGgQrcT-1G3dHWQQfWjYBu1YQ2ypv9y86dgogg@mail.gmail.com
Backpatch-through: 15
2023-01-13 09:30:12 +09:00
Robert Haas aa26980ca0 Improve documentation of the CREATEROLE attibute.
In user-manag.sgml, document precisely what privileges are conveyed
by CREATEROLE. Make particular note of the fact that it allows
changing passwords and granting access to high-privilege roles.
Also remove the suggestion of using a user with CREATEROLE and
CREATEDB instead of a superuser, as there is no real security
advantage to this approach.

Elsewhere in the documentation, adjust text that suggests that
<literal>CREATEROLE</literal> only allows for role creation, and
refer to the documentation in user-manag.sgml as appropriate.

Patch by me, reviewed by Álvaro Herrera

Discussion: http://postgr.es/m/CA+TgmoZBsPL8nPhvYecx7iGo5qpDRqa9k_AcaW1SbOjugAY1Ag@mail.gmail.com
2023-01-03 14:53:38 -05:00
Michael Paquier c772dfe07a Fix typos in comments, code and documentation
While on it, newlines are removed from the end of two elog() strings.
The others are simple grammar mistakes.  One comment in pg_upgrade
referred incorrectly to sequences since a7e5457.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20221230231257.GI1153@telsasoft.com
Backpatch-through: 11
2023-01-03 16:26:27 +09:00
Bruce Momjian 1fbcb1360b Update copyright for 2023
Backpatch-through: 11
2023-01-02 15:00:37 -05:00
Alvaro Herrera d8209d0917
Rework <warning> box about column list combining in logical replication
After some copy-edit I made in commit 3a06a79cd1, we have a <sect2>
that only contains a warning box.  This doesn't look good.  Rework by
moving the sect2 title to be the warning's title, and put the 'id' to it
as well, so that the external reference continues to work.

Backpatch to 15.

In branch master, I also take the opportunity to add titles to a couple
of other warning boxes elsewhere in the documentation.

Discussion: https://postgr.es/m/20221219164713.ccnlvtkyj6lmshqq@alvherre.pgsql
2022-12-23 17:49:51 +01:00
Alvaro Herrera 2655ecde2c
Fix event trigger example
Commit 2f9661311b changed command tags from strings to numbers, but
forgot to adjust the code in the event trigger example, which
consequently failed to compile.

While fixing that, improve the indentation to adhere to pgindent style.

Backpatch to v13, where the change was introduced.

Author: Laurenz Albe
Discussion: https://postgr.es/m/81e36ac17dc80489e74dc5b6914afa6ccdb1a99d.camel@cybertec.at
2022-12-23 13:21:41 +01:00
Tom Lane 18431ee6f5 Rethink handling of [Prevent|Is]InTransactionBlock in pipeline mode.
Commits f92944137 et al. made IsInTransactionBlock() set the
XACT_FLAGS_NEEDIMMEDIATECOMMIT flag before returning "false",
on the grounds that that kept its API promises equivalent to those of
PreventInTransactionBlock().  This turns out to be a bad idea though,
because it allows an ANALYZE in a pipelined series of commands to
cause an immediate commit, which is unexpected.

Furthermore, if we return "false" then we have another issue,
which is that ANALYZE will decide it's allowed to do internal
commit-and-start-transaction sequences, thus possibly unexpectedly
committing the effects of previous commands in the pipeline.

To fix the latter situation, invent another transaction state flag
XACT_FLAGS_PIPELINING, which explicitly records the fact that we
have executed some extended-protocol command and not yet seen a
commit for it.  Then, require that flag to not be set before allowing
InTransactionBlock() to return "false".

Having done that, we can remove its setting of NEEDIMMEDIATECOMMIT
without fear of causing problems.  This means that the API guarantees
of IsInTransactionBlock now diverge from PreventInTransactionBlock,
which is mildly annoying, but it seems OK given the very limited usage
of IsInTransactionBlock.  (In any case, a caller preferring the old
behavior could always set NEEDIMMEDIATECOMMIT for itself.)

For consistency also require XACT_FLAGS_PIPELINING to not be set
in PreventInTransactionBlock.  This too is meant to prevent commands
such as CREATE DATABASE from silently committing previous commands
in a pipeline.

Per report from Peter Eisentraut.  As before, back-patch to all
supported branches (which sadly no longer includes v10).

Discussion: https://postgr.es/m/65a899dd-aebc-f667-1d0a-abb89ff3abf8@enterprisedb.com
2022-12-13 14:23:59 -05:00
Dean Rasheed ee1c6728d8 Update MERGE docs to mention that ONLY is supported.
Commit 7103ebb7aa added support for MERGE, which included support for
inheritance hierarchies, but didn't document the fact that ONLY could
be specified before the source and/or target tables to exclude tables
inheriting from the tables specified.

Update merge.sgml to mention this, and while at it, add some
regression tests to cover it.

Dean Rasheed, reviewed by Nathan Bossart.

Backpatch to 15, where MERGE was added.

Discussion: https://postgr.es/m/CAEZATCU0XM-bJCvpJuVRU3UYNRqEBS6g4-zH%3Dj9Ye0caX8F6uQ%40mail.gmail.com
2022-12-09 10:03:04 +00:00
Michael Paquier 74a600a150 doc: Add missing <varlistentry> markups for developer GUCs
Missing such markups makes it impossible to create links back to these
GUCs, and all the other parameters have one already.

Author: Ian Lawrence Barwick
Discussion: https://postgr.es/m/CAB8KJ=jx=6dFB_EN3j0UkuvG3cPu5OmQiM-ZKRAz+fKvS+u8Ng@mail.gmail.com
Backpatch-through: 11
2022-12-05 11:23:27 +09:00
Tom Lane e10799aa25 Doc: add example of round(v, s) with negative s.
This has always worked, but you'd be unlikely to guess it
from the documentation.  Add an example showing it.

Lack of docs noted by David Johnston.  Back-patch to v13;
the documentation layout we used before that was not very
amenable to squeezing in multiple examples.

Discussion: https://postgr.es/m/CAKFQuwZ4Vy1Xty0G5Ok+ot=NDrU3C6hzF1JwUk-FEkwe3V9_RA@mail.gmail.com
2022-12-01 12:26:12 -05:00
Tom Lane afa4a4f764 Doc: word-smith the discussion of secure schema usage patterns.
Rearrange the discussion of user-private schemas so that details
applying only to upgraded-from-pre-v15 databases are in a follow-on
paragraph, not in the main description of how to set up this pattern.
This seems a little clearer even today, and it'll get more so as
pre-v15 systems fade into the sunset.

Wording contributions from Robert Haas, Tom Lane, Noah Misch.

Discussion: https://postgr.es/m/CA+TgmoYUHsfp90inEMAP0yNr7Y_L6EphPH1YOon1JKtBztXHyQ@mail.gmail.com
2022-12-01 12:10:25 -05:00
Bruce Momjian f79cca5bfd revert: add transaction processing chapter with internals info
This doc patch (master hash 66bc9d2d3e) was decided to be too
significant for backpatching, so reverted in all but master.  Also fix
SGML file header comment in master.

Reported-by:  	Peter Eisentraut

Discussion: https://postgr.es/m/c6304b19-6ff7-f3af-0148-cf7aa7e2fbfd@enterprisedb.com

Backpatch-through: 11
2022-12-01 10:45:08 -05:00
Bruce Momjian 8592b56faf doc: add transaction processing chapter with internals info
This also adds references to this new chapter at relevant sections of
our documentation.  Previously much of these internal details were
exposed to users, but not explained.  This also updates RELEASE
SAVEPOINT.

Discussion: https://postgr.es/m/CANbhV-E_iy9fmrErxrCh8TZTyenpfo72Hf_XD2HLDppva4dUNA@mail.gmail.com

Author: Simon Riggs, Laurenz Albe

Reviewed-by: Bruce Momjian

Backpatch-through: 11
2022-11-29 20:49:52 -05:00
Daniel Gustafsson 4f997ad062 Replace link to Hunspell with the current homepage
The Hunspell project moved from Sourceforge to Github sometime
in 2016, so update our links to match the new URL.  Backpatch
the doc changes to all supported versions.

Discussion: https://postgr.es/m/DC9A662A-360D-4125-A453-5A6CB9C6C4B4@yesql.se
Backpatch-through: v11
2022-11-21 23:25:48 +01:00
Tom Lane f754e7600a Doc: remove pg_prepared_statements.result_types from v15 docs.
This column is new in v16, but it was listed in the v15 docs too
via a back-patching fumble.

Per report from Peter Gigowski; diagnosis by Julien Rouhaud.

Discussion: https://postgr.es/m/CAM7cJ6XY_PAmx0kGn6U307EKZ+qXDFEBH27WP87-_ygetnBuxQ@mail.gmail.com
2022-11-13 10:42:03 -05:00
Tom Lane 362ba3e932 Doc: improve tutorial section about grouped aggregates.
Commit fede15417 introduced FILTER by jamming it into the existing
example introducing HAVING, which seems pedagogically poor to me;
and it added no information about what the keyword actually does.
Not to mention that the claimed output didn't match the sample
data being used in this running example.

Revert that and instead make an independent example using FILTER.
To help drive home the point that it's a per-aggregate filter,
we need to use two aggregates not just one; for consistency
expand all the examples in this segment to do that.

Also adjust the example using WHERE ... LIKE so that it'd produce
nonempty output with this sample data, and show that output.

Back-patch, as the previous patch was.  (Sadly, v10 is now out
of scope.)

Discussion: https://postgr.es/m/166794307526.652.9073408178177444190@wrigleys.postgresql.org
2022-11-08 18:25:03 -05:00
Tom Lane b7f9c762a8 Last-minute updates for release notes. 2022-11-07 13:02:24 -05:00
Tom Lane ca3f0d44ac Release notes for 15.1, 14.6, 13.9, 12.13, 11.18, 10.23. 2022-11-06 11:07:28 -05:00
Tom Lane bc62182f0a First-draft release notes for 15.1.
As usual, the release notes for other branches will be made by cutting
these down, but put them up for community review first.

Also as usual for a .1 release, there are some entries here that
are not really relevant for v15 because they already appeared in 15.0.
Those'll be removed later.
2022-11-04 12:46:02 -04:00
Tom Lane 387e059f8e docs: Improve pg_settings_get_flags docs.
In the docs, the GUC flags that pg_settings_get_flags() reported were
listed using <simplelist>. But the list was treated as separate lines
in the existing function table and didn't look good. For better view,
this commit separates the list from the table entry for
pg_settings_get_flags() and adds the table for it at the bottom of
the existing function table.

Author: Fujii Masao
Reviewed-by: Alvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/f093edf9-6e5a-b119-ee50-6a2c97c79ee8@oss.nttdata.com

Back-patch of f2d0c7f18 into v15.
Discussion: https://postgr.es/m/20221103123320.GQ16921@telsasoft.com
2022-11-03 19:53:35 -04:00
Michael Paquier 468a9f37fb doc: Fix some descriptions related to pg_ident_file_mappings
pg_ident_file_mappings.line_number was described as a line number in
pg_ident.conf for a "rule" number, but this should refer to a "map".
The same inconsistent term was used in the main paragraph describing the
view.

Extracted from a patch by the same author.  Issue introduced by
a2c8499 where this view has been added.

Author: Julien Rouhaud
Discussion: https://postgr.es/m/20221026031948.cbrnzgy5e7glsq2d@jrouhaud
Backpatch-through: 15
2022-11-02 11:56:28 +09:00
Peter Eisentraut d2354b6eec Remove incorrect name from release notes
This name was incorrect in the underlying commit message.  (The
correct name is already listed.)

Reported-by: Mark Wong
2022-11-01 14:17:36 +01:00
Michael Paquier f975df7203 doc: Fix type of cursor_position in jsonlog table
This entry was listed as a "string", but it is a "number.  The other
fields are correctly described, on a second look.

Reported-by: Nuko Yokohama
Author: Tatsuo Ishii
Discussion: https://postgr.es/m/CAF3Gu1awoVoDP5d0_eN=cR=QkGVwH+OtFvwJkkc5cB_ZMWjyeA@mail.gmail.com
Backpatch-through: 15
2022-10-25 09:29:54 +09:00
David Rowley 536a3b8703 Doc: fix outdated wording about parallel seq scans
56788d215 adjusted the parallel seq scan code so that instead of handing
out a single block at a time to parallel workers, it now hands out ranges
of blocks.

Here we update the documentation which still claimed that workers received
just 1 block at a time.

Reported-by: Zhang Mingli
Discussion: https://postgr.es/m/17c99615-2c3b-4e4e-9d0b-424a66a7bccd@Spark
Backpatch-through: 14, where 56788d215 was added.
2022-10-21 09:29:56 +13:00
Michael Paquier 5d2a47a292 Rework shutdown callback of archiver modules
As currently designed, with a callback registered in a ERROR_CLEANUP
block, the shutdown callback would get called twice when updating
archive_library on SIGHUP, which is something that we want to avoid to
ease the life of extension writers.

Anyway, an ERROR in the archiver process is treated as a FATAL, stopping
it immediately, hence there is no need for a ERROR_CLEANUP block.
Instead of that, the shutdown callback is not called upon
before_shmem_exit(), giving to the modules the opportunity to do any
cleanup actions before the server shuts down its subsystems.

While on it, this commit adds some testing coverage for the shutdown
callback.  Neither shell_archive nor basic_archive have been using it,
and one is added to shell_archive, whose trigger is checked in a TAP
test through a shutdown sequence.

Author: Nathan Bossart, Bharath Rupireddy
Reviewed-by: Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20221015221328.GB1821022@nathanxps13
Backpatch-through: 15
2022-10-19 14:07:01 +09:00
Bruce Momjian ef325ee04d doc: move the mention of aggregate JSON functions up in section
It was previously easily overlooked at the end of several tables.

Reported-by: Alex Denman

Discussion: https://postgr.es/m/166335888474.659.16897487975376230364@wrigleys.postgresql.org

Backpatch-through: 10
2022-10-17 15:21:29 -04:00
Bruce Momjian 189db21e2a doc: warn pg_stat_reset() can cause vacuum/analyze problems
The fix is to run ANALYZE.

Discussion: https://postgr.es/m/YzRr+ys98UzVQJvK@momjian.us,
   https://postgr.es/m/flat/CAKJS1f8DTbCHf9gedU0He6ARsd58E6qOhEHM1caomqj_r9MOiQ%40mail.gmail.com,
   https://postgr.es/m/CAKJS1f80o98hcfSk8j%3DfdN09S7Sjz%2BvuzhEwbyQqvHJb_sZw0g%40mail.gmail.com

Backpatch-through: 10
2022-10-17 15:07:03 -04:00
Alvaro Herrera f7eec7fe38
Fix typo in CREATE PUBLICATION reference page
While at it, simplify wording a bit.

Author: Takamichi Osumi <osumi.takamichi@fujitsu.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Discussion: https://postgr.es/m/TYCPR01MB8373F93F5D094A2BE648990DED259@TYCPR01MB8373.jpnprd01.prod.outlook.com
2022-10-13 13:36:14 +02:00
Michael Paquier 91416f45f8 doc: Fix description of replication command CREATE_REPLICATION_SLOT
The output plugin name is a mandatory option when creating a logical
slot, but the grammar documented was not described as such.  While on
it, fix two comments in repl_gram.y to show that TEMPORARY is an
optional grammar choice.

Author: Ayaki Tachikake
Discussion: https://postgr.es/m/OSAPR01MB2852607B2329FFA27834105AF1229@OSAPR01MB2852.jpnprd01.prod.outlook.com
Backpatch-through: 15
2022-10-13 08:53:44 +09:00
Tom Lane 42d203ccfa Doc: improve recommended systemd unit file.
Add
    After=network-online.target
    Wants=network-online.target
to the suggested unit file for starting a Postgres server.
This delays startup until the network interfaces have been
configured; without that, any attempt to bind to a specific
IP address will fail.

If listen_addresses is set to "localhost" or "*", it might be
possible to get away with the less restrictive "network.target",
but I don't think we need to get into such detail here.

Per suggestion from Pablo Federico.

Discussion: https://postgr.es/m/166552157407.591805.10036014441784710940@wrigleys.postgresql.org
2022-10-12 10:51:25 -04:00
Tom Lane 2a7ce2e2ce Doc: update release date for v15.
Drat, forgot this ...
2022-10-10 16:57:37 -04:00
Peter Eisentraut 48c81b57e9 Update list of acknowledgments in release notes
current through c3b5992b91
2022-10-10 08:15:29 +02:00
Bruce Momjian be5cf46081 relnotes: fix author names
Reported-by: Elena Indrupskaya

Discussion: https://postgr.es/m/0af43b49-1646-93d0-ccf1-bb3c635c8c6f@postgrespro.ru

Author: Elena Indrupskaya

Backpatch-through: 15 only
2022-10-05 16:17:30 -04:00
Bruce Momjian d2d67949f5 doc: clarify description for log_startup_progress_interval
Reported-by: Elena Indrupskaya

Discussion: https://postgr.es/m/0af43b49-1646-93d0-ccf1-bb3c635c8c6f@postgrespro.ru

Author: Elena Indrupskaya

Backpatch-through: 15
2022-10-05 15:53:40 -04:00
Tom Lane b1c73e1cf1 Doc: update v15 release notes. 2022-10-03 11:06:33 -04:00
Tom Lane 443df6e2db Revert "Optimize order of GROUP BY keys".
This reverts commit db0d67db24 and
several follow-on fixes.  The idea of making a cost-based choice
of the order of the sorting columns is not fundamentally unsound,
but it requires cost information and data statistics that we don't
really have.  For example, relying on procost to distinguish the
relative costs of different sort comparators is pretty pointless
so long as most such comparator functions are labeled with cost 1.0.
Moreover, estimating the number of comparisons done by Quicksort
requires more than just an estimate of the number of distinct values
in the input: you also need some idea of the sizes of the larger
groups, if you want an estimate that's good to better than a factor of
three or so.  That's data that's often unknown or not very reliable.
Worse, to arrive at estimates of the number of calls made to the
lower-order-column comparison functions, the code needs to make
estimates of the numbers of distinct values of multiple columns,
which are necessarily even less trustworthy than per-column stats.
Even if all the inputs are perfectly reliable, the cost algorithm
as-implemented cannot offer useful information about how to order
sorting columns beyond the point at which the average group size
is estimated to drop to 1.

Close inspection of the code added by db0d67db2 shows that there
are also multiple small bugs.  These could have been fixed, but
there's not much point if we don't trust the estimates to be
accurate in-principle.

Finally, the changes in cost_sort's behavior made for very large
changes (often a factor of 2 or so) in the cost estimates for all
sorting operations, not only those for multi-column GROUP BY.
That naturally changes plan choices in many situations, and there's
precious little evidence to show that the changes are for the better.
Given the above doubts about whether the new estimates are really
trustworthy, it's hard to summon much confidence that these changes
are better on the average.

Since we're hard up against the release deadline for v15, let's
revert these changes for now.  We can always try again later.

Note: in v15, I left T_PathKeyInfo in place in nodes.h even though
it's unreferenced.  Removing it would be an ABI break, and it seems
a bit late in the release cycle for that.

Discussion: https://postgr.es/m/TYAPR01MB586665EB5FB2C3807E893941F5579@TYAPR01MB5866.jpnprd01.prod.outlook.com
2022-10-03 10:56:16 -04:00
Michael Paquier 64b431d15c doc: Fix some grammar and typos
This fixes some areas related to logical replication and custom RMGRs.

Author: Ekaterina Kiryanova
Discussion: https://postgr.es/m/fa4773f1-1396-384a-bcd7-85b5e013f399@postgrespro.ru
Backpatch-through: 15
2022-10-01 15:28:11 +09:00
Daniel Gustafsson a613474411 doc: Fix PQsslAttribute docs for compression
The compression parameter to PQsslAttribute has never returned the
compression method used, it has always returned "on" or "off since
it was added in commit 91fa7b4719. Backpatch through v10.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/B9EC60EC-F665-47E8-A221-398C76E382C9@yesql.se
Backpatch-through: v10
2022-09-30 12:03:48 +02:00
Tom Lane cae4688ce8 Fix bogus behavior of PQsslAttribute(conn, "library").
Commit ebc8b7d44 intended to change the behavior of
PQsslAttribute(NULL, "library"), but accidentally also changed
what happens with a non-NULL conn pointer.  Undo that so that
only the intended behavior change happens.  Clarify some
associated documentation.

Per bug #17625 from Heath Lord.  Back-patch to v15.

Discussion: https://postgr.es/m/17625-fc47c78b7d71b534@postgresql.org
2022-09-29 17:28:09 -04:00