If not all backups have the same checksum status, but the final backup
has checksums enabled, then the output directory may include pages
with invalid checksums. Document this limitation and explain how to
work around it.
In a future release, we may want to teach pg_combinebackup to
recompute page checksums when required, but as feature freeze has come
and gone, it seems a bit too late to do that for this release.
Patch by me, reviewed by Daniel Gustafsson
Discussion: http://postgr.es/m/CA+TgmoZugzOSmgkx97u3pc0M7U8LycWvugqoyWBv6j15a4hE5g@mail.gmail.com
To take an incremental backup, you use the new replication command
UPLOAD_MANIFEST to upload the manifest for the prior backup. This
prior backup could either be a full backup or another incremental
backup. You then use BASE_BACKUP with the INCREMENTAL option to take
the backup. pg_basebackup now has an --incremental=PATH_TO_MANIFEST
option to trigger this behavior.
An incremental backup is like a regular full backup except that
some relation files are replaced with files with names like
INCREMENTAL.${ORIGINAL_NAME}, and the backup_label file contains
additional lines identifying it as an incremental backup. The new
pg_combinebackup tool can be used to reconstruct a data directory
from a full backup and a series of incremental backups.
Patch by me. Reviewed by Matthias van de Meent, Dilip Kumar, Jakub
Wartak, Peter Eisentraut, and Álvaro Herrera. Thanks especially to
Jakub for incredibly helpful and extensive testing.
Discussion: http://postgr.es/m/CA+TgmoYOYZfMCyOXFyC-P+-mdrZqm5pP2N7S-r0z3_402h9rsA@mail.gmail.com
Commit 5ef1eefd76, which added
archive_library, purged most mentions of archive_command from the
documentation. This is inappropriate, since archive_command is still
a feature in use and users will want to see information about it.
This restores all the removed mentions and rephrases things so that
archive_command and archive_library are presented as alternatives of
each other.
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/9366d634-a917-85a9-4991-b2a4859edaf9@enterprisedb.com
Referring to the WAL as just "log" invites confusion with the
postmaster log, so avoid doing that in docs and error messages.
Also shorten "WAL segment file" to just "WAL file" in various
places.
Bharath Rupireddy, reviewed by Nathan Bossart and Kyotaro Horiguchi
Discussion: https://postgr.es/m/CALj2ACUeXa8tDPaiTLexBDMZ7hgvaN+RTb957-cn5qwv9zf-MQ@mail.gmail.com
This commit adds or fixes markups used in a couple of places in the docs
(for <command>, <systemitem> and <literal>). While on it, this
clarifies some of the documentation added recently for archiving modules
with archive_command, that would still be used as default choice if no
external module is defined (though an archive module could as well use
an archive_command).
Author: Maxim Yablokov
Discussion: https://postgr.es/m/b47ec4e8-6f6a-2aba-038e-d5db150b245e@postgrespro.ru
Backpatch-through: 15
Historically we've been lax about this, but seeing that we're not
lax in C files, there doesn't seem to be a good reason to be so
in the documentation. Remove the existing occurrences (mostly
though not entirely in copied-n-pasted psql output), and modify
.gitattributes so that "git diff --check" will warn about future
cases.
While at it, add *.pm to the set of extensions .gitattributes
knows about, and remove some obsolete entries for files that
we don't have in the tree anymore.
Per followup discussion of commit 5a892c9b1.
Discussion: https://postgr.es/m/E1nfcV1-000kOR-E5@gemulon.postgresql.org
This includes removing documentation for stats_temp_directory, adding
documentation for stats_fetch_consistency, rephrasing references to the stats
collector and documenting that starting a cleanly shut down standby will not
remove stats anymore. The latter point might require further wordsmithing, it
wasn't easy to adjust some of the existing content.
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Thomas Munro <thomas.munro@gmail.com>
Reviewed-By: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-By: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-By: Lukas Fittl <lukas@fittl.com>
Discussion: https://postgr.es/m/20220303021600.hs34ghqcw6zcokdh@alap3.anarazel.de
Exclusive-mode backups have been deprecated since 9.6 (when
non-exclusive backups were introduced) due to the issues
they can cause should the system crash while one is running and
generally because non-exclusive provides a much better interface.
Further, exclusive backup mode wasn't really being tested (nor was most
of the related code- like being able to log in just to stop an exclusive
backup and the bits of the state machine related to that) and having to
possibly deal with an exclusive backup and the backup_label file
existing during pg_basebackup, pg_rewind, etc, added other complexities
that we are better off without.
This patch removes the exclusive backup mode, the various special cases
for dealing with it, and greatly simplifies the online backup code and
documentation.
Authors: David Steele, Nathan Bossart
Reviewed-by: Chapman Flack
Discussion: https://postgr.es/m/ac7339ca-3718-3c93-929f-99e725d1172c@pgmasters.nethttps://postgr.es/m/CAHg+QDfiM+WU61tF6=nPZocMZvHDzCK47Kneyb0ZRULYzV5sKQ@mail.gmail.com
Running a shell command for each file to be archived has a lot of
overhead and may not offer as much error checking as you want, or the
exact semantics that you want. So, offer the option to call a loadable
module for each file to be archived, rather than running a shell command.
Also, add a 'basic_archive' contrib module as an example implementation
that archives to a local directory.
Nathan Bossart, with a little bit of kibitzing by me.
Discussion: http://postgr.es/m/20220202224433.GA1036711@nathanxps13
The current instructions describing how to write the backup_label and
tablespace_map files are confusing. For example, opening a file in text
mode on Windows and copy-pasting the file's contents would result in a
failure at recovery because of the extra CRLF characters generated. The
documentation was not stating that clearly, and per discussion this is
not considered as a supported scenario.
This commit extends a bit the documentation to mention that it may be
required to open the file in binary mode before writing its data.
Reported-by: Wang Shenhao
Author: David Steele
Reviewed-by: Andrew Dunstan, Magnus Hagander
Discussion: https://postgr.es/m/8373f61426074f2cb6be92e02f838389@G08CNEXMBPEKD06.g08.fujitsu.local
Backpatch-through: 9.6
The default value of recovery_target_timeline was changed in v12,
but the description about the default behavior of that was not updated.
Back-patch to v12 where the default behavior of recovery_target_timeline
was changed.
Author: Benoit Lobréau
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CAPE8EZ7c3aruEmM24GYkj8y8WmHKD1m9TtPtgCF0nQ3zw4LCkQ@mail.gmail.com
SQL commands are generally marked up as <command>, except when a link
to a reference page is used using <xref>. But the latter doesn't
create monospace markup, so this looks strange especially when a
paragraph contains a mix of links and non-links.
We considered putting <command> in the <refentrytitle> on the target
side, but that creates some formatting side effects elsewhere.
Generally, it seems safer to solve this on the link source side.
We can't put the <xref> inside the <command>; the DTD doesn't allow
this. DocBook 5 would allow the <command> to have the linkend
attribute itself, but we are not there yet.
So to solve this for now, convert the <xref>s to <link> plus
<command>. This gives the correct look and also gives some more
flexibility what we can put into the link text (e.g., subcommands or
other clauses). In the future, these could then be converted to
DocBook 5 style.
I haven't converted absolutely all xrefs to SQL command reference
pages, only those where we care about the appearance of the link text
or where it was otherwise appropriate to make the appearance match a
bit better. Also in some cases, the links where repetitive, so in
those cases the links where just removed and replaced by a plain
<command>. In cases where we just want the link and don't
specifically care about the generated link text (typically phrased
"for further information see <xref ...>") the xref is kept.
Reported-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/87o8pco34z.fsf@wibble.ilmari.org
Especially, warn about the hazards of mishandling the backup_label
file. Adjust a couple of server messages to be more clear about
the hazards associated with removing backup_label files, too.
David Steele and Robert Haas, reviewed by Laurenz Albe, Martín
Marqués, Peter Eisentraut, and Magnus Hagander.
Discussion: http://postgr.es/m/7d85c387-000e-16f0-e00b-50bf83c22127@pgmasters.net
recovery.conf settings are now set in postgresql.conf (or other GUC
sources). Currently, all the affected settings are PGC_POSTMASTER;
this could be refined in the future case by case.
Recovery is now initiated by a file recovery.signal. Standby mode is
initiated by a file standby.signal. The standby_mode setting is
gone. If a recovery.conf file is found, an error is issued.
The trigger_file setting has been renamed to promote_trigger_file as
part of the move.
The documentation chapter "Recovery Configuration" has been integrated
into "Server Configuration".
pg_basebackup -R now appends settings to postgresql.auto.conf and
creates a standby.signal file.
Author: Fujii Masao <masao.fujii@gmail.com>
Author: Simon Riggs <simon@2ndquadrant.com>
Author: Abhijit Menon-Sen <ams@2ndquadrant.com>
Author: Sergei Kornilov <sk@zsrv.org>
Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
The backup history file has been no longer necessary for recovery
since the version 9.0. It's now basically just for informational purpose.
But previously the documentations still described that a recovery
requests the backup history file to proceed. The commit fixes this
documentation bug.
Back-patch to all supported versions.
Author: Yugo Nagata
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20180626174752.0ce505e3.nagata@sraoss.co.jp
Since some preparation work had already been done, the only source
changes left were changing empty-element tags like <xref linkend="foo">
to <xref linkend="foo"/>, and changing the DOCTYPE.
The source files are still named *.sgml, but they are actually XML files
now. Renaming could be considered later.
In the build system, the intermediate step to convert from SGML to XML
is removed. Everything is build straight from the source files again.
The OpenSP (or the old SP) package is no longer needed.
The documentation toolchain instructions are updated and are much
simpler now.
Peter Eisentraut, Alexander Lakhin, Jürgen Purtz
Previously server reserved WAL for last two checkpoints,
which used too much disk space for small servers.
Bumps PG_CONTROL_VERSION
Author: Simon Riggs <simon@2ndQuadrant.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Add docs to explain this for other backup mechanisms
Author: David Steele <david@pgmasters.net>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndQuadrant.com> et al
For DocBook XML compatibility, don't use SGML empty tags (</>) anymore,
replace by the full tag name. Add a warning option to catch future
occurrences.
Alexander Lakhin, Jürgen Purtz
For performance reasons a larger segment size than the default 16MB
can be useful. A larger segment size has two main benefits: Firstly,
in setups using archiving, it makes it easier to write scripts that
can keep up with higher amounts of WAL, secondly, the WAL has to be
written and synced to disk less frequently.
But at the same time large segment size are disadvantageous for
smaller databases. So far the segment size had to be configured at
compile time, often making it unrealistic to choose one fitting to a
particularly load. Therefore change it to a initdb time setting.
This includes a breaking changes to the xlogreader.h API, which now
requires the current segment size to be configured. For that and
similar reasons a number of binaries had to be taught how to recognize
the current segment size.
Author: Beena Emerson, editorialized by Andres Freund
Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael
Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja
Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
Our documentation hasn't really caught up with the fact that
non-exclusive backups can now be taken using pg_start_backup and
pg_stop_backup even on standbys. Update, also correcting some
errors introduced by 52f8a59dd9.
Updates to the 9.6 documentation are needed as well, but that
will need a separate patch as some things are different on that
version.
David Steele, reviewed by Robert Haas and Michael Paquier
Discussion: http://postgr.es/m/d4d951b9-89c0-6bc1-b6ff-d0b2dd5a8966@pgmasters.net
Previously, it had no effect. Now, if archive_mode=always, it will
work, and if not, you'll get a warning.
Masahiko Sawada, Michael Paquier, and Robert Haas. The patch as
submitted also changed the behavior so that we would write and remove
history files on standbys, but that seems like material for a separate
patch to me.
Discussion: http://postgr.es/m/CAD21AoC2Xw6M=ZJyejq_9d_iDkReC_=rpvQRw5QsyzKQdfYpkw@mail.gmail.com
Internally, we have supported the option to either wait for all of the
WAL associated with a backup to be archived, or to return immediately.
This option is useful to users of pg_stop_backup() as well, when they
are reading the stop backup record position and checking that the WAL
they need has been archived independently.
This patch adds an additional, optional, argument to pg_stop_backup()
which allows the user to indicate if they wish to wait for the WAL to be
archived or not. The default matches current behavior, which is to
wait.
Author: David Steele, with some minor changes, doc updates by me.
Reviewed by: Takayuki Tsunakawa, Fujii Masao
Discussion: https://postgr.es/m/758e3fd1-45b4-5e28-75cd-e9e7f93a4c02@pgmasters.net
The warning about hash indexes not being write-ahead logged and their
use being discouraged has been removed. "snapshot too old" is now
supported for tables with hash indexes. Most importantly, barring
bugs, hash indexes will now be crash-safe and usable on standbys.
This commit doesn't yet add WAL consistency checking for hash
indexes, as we now have for other index types; a separate patch has
been submitted to cure that lack.
Amit Kapila, reviewed and slightly modified by me. The larger patch
series of which this is a part has been reviewed and tested by Álvaro
Herrera, Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper
Pedersen.
Discussion: http://postgr.es/m/CAA4eK1JOBX=YU33631Qh-XivYXtPSALh514+jR8XeD7v+K3r_Q@mail.gmail.com
Output a message about checkpoint starting in verbose mode of
pg_basebackup, and make the documentation state more clearly that this
happens.
Author: Michael Banck
Commit f82ec32ac3 renamed the pg_xlog
directory to pg_wal. To make things consistent, and because "xlog" is
terrible terminology for either "transaction log" or "write-ahead log"
rename all SQL-callable functions that contain "xlog" in the name to
instead contain "wal". (Note that this may pose an upgrade hazard for
some users.)
Similarly, rename the xlog_position argument of the functions that
create slots to be called wal_position.
Discussion: https://www.postgresql.org/message-id/CA+Tgmob=YmA=H3DbW1YuOXnFVgBheRmyDkWcD9M8f=5bGWYEoQ@mail.gmail.com
This changes the default values of the following parameters:
wal_level = replica
max_wal_senders = 10
max_replication_slots = 10
in order to make it possible to make a backup and set up simple
replication on the default settings, without requiring a system restart.
Discussion: https://postgr.es/m/CABUevEy4PR_EAvZEzsbF5s+V0eEvw7shJ2t-AUwbHOjT+yRb3A@mail.gmail.com
Reviewed by Peter Eisentraut. Benchmark help from Tomas Vondra.
"xlog" is not a particularly clear abbreviation for "write-ahead log",
and it sometimes confuses users into believe that the contents of the
"pg_xlog" directory are not critical data, leading to unpleasant
consequences. So, rename the directory to "pg_wal".
This patch modifies pg_upgrade and pg_basebackup to understand both
the old and new directory layouts; the former is necessary given the
purpose of the tool, while the latter merely avoids an unnecessary
backward-compatibility break.
We may wish to consider renaming other programs, switches, and
functions which still use the old "xlog" naming to also refer to
"wal". However, that's still under discussion, so let's do just this
much for now.
Discussion: CAB7nPqTeC-8+zux8_-4ZD46V7YPwooeFxgndfsq5Rg8ibLVm1A@mail.gmail.com
Michael Paquier
The list of files and directories that pg_basebackup excludes from the
backup was somewhat incomplete and unorganized. Change that with having
the exclusion driven from tables. Clean up some code around it. Also
document the exclusions in more detail so that users of pg_start_backup
can make use of it as well.
The contents of these directories are now excluded from the backup:
pg_dynshmem, pg_notify, pg_serial, pg_snapshots, pg_subtrans
Also fix a bug that a pg_repl_slot or pg_stat_tmp being a symlink would
cause a corrupt tar header to be created. Now such symlinks are
included in the backup as empty directories. Bug found by Ashutosh
Sharma <ashu.coek88@gmail.com>.
From: David Steele <david@pgmasters.net>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
This includes the rest of the documentation that was not included
in 7117685. A larger restructure would still be wanted, but with
this commit the documentation of the new features is complete.
Now that pg_dump will properly dump out any ACL changes made to
functions which exist in pg_catalog, switch to using the GRANT system
to manage access to those functions.
This means removing 'if (!superuser()) ereport()' checks from the
functions themselves and then REVOKEing EXECUTE right from 'public' for
these functions in system_views.sql.
Reviews by Alexander Korotkov, Jose Luis Tallon
Robert Haas
Peter Eisentraut
Tatsuo Ishii
Tom Lane
Michael Paquier
Noah Misch
Fujii Masao
Daniel Gustafsson
Andres Freund
Stephen Frost
Bruce Momjian
Alvaro Herrera
Peter Eisentraut
Simon Riggs
Magnus Hagander