sysctl is more portable than Linux's /proc/sys file tree, and
often easier to use too. That's why most of our docs refer to
sysctl when talking about how to adjust kernel parameters.
Bring the few stragglers into line.
Discussion: https://postgr.es/m/361175.1661187463@sss.pgh.pa.us
This commit adds or fixes used markups in a couple of places in the docs
(for <command>, <systemitem> and <literal>). While on it, clarify 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
The table column that stores this is of type oid, but is actually limited
to uint16 and has a different path for creating new values. Some of
the documentation already referred to it as an ID, so let's standardize
on that.
While at it, most format strings already use %u, so for consintency
change the remaining stragglers using %d.
Per suggestions from Tom Lane and Justin Pryzby
Discussion: https://www.postgresql.org/message-id/3437166.1659620465%40sss.pgh.pa.us
Backpatch to v15
This event can happen when using SET ACCESS METHOD, as the data files of
the materialized need a full refresh but this command tag was not
updated to reflect that. The documentation is updated to track this
behavior.
Author: Onder Kalaci
Discussion: https://postgr.es/m/CACawEhXwHN3X34FiwoYG8vXR-oyUdrp7qcfRWSzS+NPahS5gSw@mail.gmail.com
Backpatch-through: 15
The messages were using 'two-phase transaction' at some places and
'prepared transaction' at other places. Make them consistently use
'prepared transaction'.
Reported-by: Ekaterina Kiryanova
Author: Peter Smith
Reviewed by: Amit Kapila
Backpatch-through: 15
Discussion: https://postgr.es/m/745414e7-efb2-a6ae-5b83-fcbdf35aabc8@postgrespro.ru
Previously, if an extension script did CREATE OR REPLACE and there was
an existing object not belonging to the extension, it would overwrite
the object and adopt it into the extension. This is problematic, first
because the overwrite is probably unintentional, and second because we
didn't change the object's ownership. Thus a hostile user could create
an object in advance of an expected CREATE EXTENSION command, and would
then have ownership rights on an extension object, which could be
modified for trojan-horse-type attacks.
Hence, forbid CREATE OR REPLACE of an existing object unless it already
belongs to the extension. (Note that we've always forbidden replacing
an object that belongs to some other extension; only the behavior for
previously-free-standing objects changes here.)
For the same reason, also fail CREATE IF NOT EXISTS when there is
an existing object that doesn't belong to the extension.
Our thanks to Sven Klemm for reporting this problem.
Security: CVE-2022-2625
Previously, a byte with the high bit set was just transmitted
as-is by charin() and charout(). This is problematic if the
database encoding is multibyte, because the result of charout()
won't be validly encoded, which breaks various stuff that
expects all text strings to be validly encoded. We've
previously decided to enforce encoding validity rather than try
to individually harden each place that might have a problem with
such strings, so it's time to do something about "char".
To fix, represent high-bit-set characters as \ooo (backslash
and three octal digits), following the ancient "escape" format
for bytea. charin() will continue to accept the old way as well,
though that is only reachable in single-byte encodings.
Add some test cases just so there is coverage for this code.
We'll otherwise leave this question undocumented as it was before,
because we don't really want to encourage end-user use of "char".
For the moment, back-patch into v15 so that this change appears
in 15beta3. If there's not great pushback we should consider
absorbing this change into the older branches.
Discussion: https://postgr.es/m/2318797.1638558730@sss.pgh.pa.us
... when it applies to partitioned relations. This is almost the
opposite of 0c06534bd6, which removed references to "partition" in
favour of "child".
Author: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/20220525013248.GO19626@telsasoft.com
We have a few commands that "can't run in a transaction block",
meaning that if they complete their processing but then we fail
to COMMIT, we'll be left with inconsistent on-disk state.
However, the existing defenses for this are only watertight for
simple query protocol. In extended protocol, we didn't commit
until receiving a Sync message. Since the client is allowed to
issue another command instead of Sync, we're in trouble if that
command fails or is an explicit ROLLBACK. In any case, sitting
in an inconsistent state while waiting for a client message
that might not come seems pretty risky.
This case wasn't reachable via libpq before we introduced pipeline
mode, but it's always been an intended aspect of extended query
protocol, and likely there are other clients that could reach it
before.
To fix, set a flag in PreventInTransactionBlock that tells
exec_execute_message to force an immediate commit. This seems
to be the approach that does least damage to existing working
cases while still preventing the undesirable outcomes.
While here, add some documentation to protocol.sgml that explicitly
says how to use pipelining. That's latent in the existing docs if
you know what to look for, but it's better to spell it out; and it
provides a place to document this new behavior.
Per bug #17434 from Yugo Nagata. It's been wrong for ages,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/17434-d9f7a064ce2a88a3@postgresql.org
We didn't explicitly say that random() uses a randomly-chosen seed
if you haven't called setseed(). Do so.
Also, remove ref/set.sgml's no-longer-accurate (and never very
relevant) statement that the seed value is multiplied by 2^31-1.
Back-patch to v12 where set.sgml's claim stopped being true.
The claim that we use a source of random bits as seed was debatable
before 4203842a1, too, so v12 seems like a good place to stop.
Per question from Carl Sopchak.
Discussion: https://postgr.es/m/f37bb937-9d99-08f0-4de7-80c91a3cfc2e@sopchak.me
We've long held the minimum at 3.80, but that's required more than
one workaround. Commit 0f39b70a6 broke it again, because it turns
out that exporting a target-specific variable didn't work in 3.80.
Considering that 3.81 is now old enough to get a driver's license,
and that the only remaining buildfarm member testing 3.80 (prairiedog)
is likely to be retired soon, let's just stop supporting 3.80.
Adjust docs and Makefile.global's minimum-version check to match.
There are a couple of comments in the Makefiles suggesting that
random things could be done differently after we desupport 3.80,
but I couldn't get excited about changing any of them right now.
Back-patch to v15, as 0f39b70a6 was.
Discussion: https://postgr.es/m/20220720172321.GL12702@telsasoft.com
Tom Lane
Michael Paquier
John Naylor
Daniel Gustafsson
Tatsuo Ishii
Bruce Momjian
Alvaro Herrera
Amit Kapila
Robert Haas