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
POSIX shm_open() can sleep for a long time and fail spuriously because
of contention on an internal lock file on Solaris (and presumably
illumos). Commit 389869af fixed the main problem with this, namely that
we could crash, but it's now clear that "posix" is not a good default.
Therefore, choose "sysv" at initdb time on Solaris and illumos. Other
choices are still available by editing the postgresql.conf file.
Back-patch only to 15, because contention is much less likely further
back, and it doesn't seem like a good idea to change this in released
branches. This should clear up the failures on build farm animal
margay.
Discussion: https://postgr.es/m/CA%2BhUKGKqKrCV5xKWfh9rnm%3Do%3DDwZLTLtnsj_XpUi9g5%3DV%2B9oyg%40mail.gmail.com
We have had a working and tunable autovacuum
for at least a decade now, so remove the recommendation to
manually vacuum tables at least every night.
Autovacuum is now also triggered by INSERTs, so we can also
remove the recommendation to run VACUUM (ANALYZE) after lots
of INSERTs or DELETEs.
Instead, suggest using autovacuum by moving the respective
paragraph up to where the importance of VACUUM is emphasized.
Author: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-By: Magnus Hagander, Peter Geoghegan
Discussion: https://postgr.es/m/6f5e3da98fec14640f389d7b84c3b413833697f4.camel@cybertec.at
This patch documents that the initial data synchronization (tablesync) for
logical replication does not take into account the publication 'publish'
parameter when copying the existing table data.
Author: Peter Smith
Reviewed-by: Shi yu, Euler Taveira, Robert Haas, Amit Kapila
Discussion: https://postgr.es/m/CAHut+PtbfALjFpS2MkrvQ+wWQKByP7CNh9RtFta-r=BHEU3S3w@mail.gmail.com
072132f0 used the attnum offset to access the raw_fields array when
checking that the attribute names of the header and of the relation
match, leading to incorrect results or even crashes if the attribute
numbers of a relation are changed, like on a dropped attribute. This
fixes the logic to use the correct attribute names for the header
matching requirements.
Also, this commit disallows HEADER MATCH in COPY TO as there is no
validation that can be done in this case.
The tests are expanded for HEADER MATCH with COPY FROM and dropped
columns, with cases where a relation has a dropped and re-added column,
as well as a reduced set of columns.
Author: Julien Rouhaud
Reviewed-by: Peter Eisentraut, Michael Paquier
Discussion: https://postgr.es/m/20220607154744.vvmitnqhyxrne5ms@jrouhaud
Three parameters have been using "int" rather than "integer" to describe
their type:
auth_delay.milliseconds
max_logical_replication_workers
pg_prewarm.autoprewarm_interval
This is inconsistent with any other integer GUCs listed in the docs
(148, as far as I can see).
Author: Peter Smith
Discussion: https://postgr.es/m/CAHut+Pv6X5T-veN2abUDUvBxZm+SSm-9otfi3LZPGyOc6u6hiA@mail.gmail.com
This reverts commits 5753d4ee32 and fe60b67250 that modified HOT to
ignore BRIN indexes. The commit message for 5753d4ee32 claims that:
When determining whether an index update may be skipped by using
HOT, we can ignore attributes indexed only by BRIN indexes. There
are no index pointers to individual tuples in BRIN, and the page
range summary will be updated anyway as it relies on visibility
info.
This is partially incorrect - it's true BRIN indexes don't point to
individual tuples, so HOT chains are not an issue, but the visibitlity
info is not sufficient to keep the index up to date. This can easily
result in corrupted indexes, as demonstrated in the hackers thread.
This does not mean relaxing the HOT restrictions for BRIN is a lost
cause, but it needs to handle the two aspects (allowing HOT chains and
updating the page range summaries) as separate. But that requires a
major changes, and it's too late for that in the current dev cycle.
Reported-by: Tomas Vondra
Discussion: https://postgr.es/m/05ebcb44-f383-86e3-4f31-0a97a55634cf@enterprisedb.com
In addition, this moves the new paragraph in the MVCC page upwards, for
a more consistent flow; some minor markup mistakes, style issues and
typos are fixed too.
Per comments from Justin Pryzby.
Discussion: https://postgr.es/m/20220511163350.GL19626@telsasoft.com
This commit, in completion of 157f873, forces a ROLLBACK for
--single-transaction only when ON_ERROR_STOP is used when one of the
steps defined by -f/-c fails. Hence, COMMIT is always used when
ON_ERROR_STOP is not set, ignoring the status code of the last action
taken in the set of switches specified by -c/-f (previously ROLLBACK
would have been issued even without ON_ERROR_STOP if the last step
failed, while COMMIT was issued if a step in-between failed as long as
the last step succeeded, leading to more inconsistency).
While on it, this adds much more test coverage in this area when not
using ON_ERROR_STOP with multiple switch patterns involving -c and -f
for query files, single queries and slash commands.
The behavior of ON_ERROR_STOP is arguably a bug, but there was no much
support for a backpatch to force a ROLLBACK on a step failure, so this
change is done only on HEAD for now.
Per discussion with Tom Lane and Kyotaro Horiguchi.
Discussion: https://postgr.es/m/Yqbc8bAdwnP02na4@paquier.xyz
The previous wording was "the underlying data type's default collation
is used", which is wrong or at least misleading. The domain inherits
the base type's collation behavior, which if "default" actually can
mean that we use some non-default collation obtained from elsewhere.
Per complaint from Jian He.
Discussion: https://postgr.es/m/CACJufxHMR8_4WooDPjjvEdaxB2hQ5a49qthci8fpKP0MKemVRQ@mail.gmail.com
Tom Lane
Michael Paquier
Alvaro Herrera
Bruce Momjian
John Naylor
Robert Haas
Thomas Munro
Fujii Masao
Magnus Hagander
Amit Kapila
Peter Eisentraut
Tomas Vondra