Break the synopsis into named parts to make it less confusing.
Make more than zero effort at applying SGML markup. Do a bit
of copy-editing of nearby text.
The synopsis revision is by Alvaro Herrera and Paul Förster,
the rest is my fault. Back-patch to v10 where multi-host
connection strings appeared.
Discussion: https://postgr.es/m/6E752D6B-487C-463E-B6E2-C32E7FB007EA@gmail.com
FreeBSD 13 gained O_DSYNC, which would normally cause wal_sync_method to
choose open_datasync as its default value. That may not be a good
choice for all systems, and performs worse than fdatasync in some
scenarios. Let's preserve the existing default behavior for now.
Like commit 576477e73c, which did the same for Linux, back-patch to all
supported releases.
Discussion: https://postgr.es/m/CA%2BhUKGLsAMXBQrCxCXoW-JsUYmdOL8ALYvaX%3DCrHqWxm-nWbGA%40mail.gmail.com
In light of recent discussions, we should instruct people to
install Apple's command line tools; installing Xcode is secondary.
Also, fix sample command for finding out the default sysroot,
as we now know that the command originally recommended can give
a result that doesn't match your OS version.
Also document the workaround to use if you really don't want
configure to select a sysroot at all.
Discussion: https://postgr.es/m/20210119111625.20435-1-james.hilliard1@gmail.com
This text claimed that the reconnection would occur "to the same
server", but there is no such guarantee in the code, nor would
insisting on that be an improvement.
Back-patch to v10 where multi-host connection strings were added.
Discussion: https://postgr.es/m/1095901.1611268376@sss.pgh.pa.us
When a tablespace is used in a partitioned relation (per commits
ca4103025d in pg12 for tables and 33e6c34c32 in pg11 for indexes),
it is possible to drop the tablespace, potentially causing various
problems. One such was reported in bug #16577, where a rewriting ALTER
TABLE causes a server crash.
Protect against this by using pg_shdepend to keep track of tablespaces
when used for relations that don't keep physical files; we now abort a
tablespace if we see that the tablespace is referenced from any
partitioned relations.
Backpatch this to 11, where this problem has been latent all along. We
don't try to create pg_shdepend entries for existing partitioned
indexes/tables, but any ones that are modified going forward will be
protected.
Note slight behavior change: when trying to drop a tablespace that
contains both regular tables as well as partitioned ones, you'd
previously get ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE and now you'll
get ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST. Arguably, the latter is more
correct.
It is possible to add protecting pg_shdepend entries for existing
tables/indexes, by doing
ALTER TABLE ONLY some_partitioned_table SET TABLESPACE pg_default;
ALTER TABLE ONLY some_partitioned_table SET TABLESPACE original_tablespace;
for each partitioned table/index that is not in the database default
tablespace. Because these partitioned objects do not have storage, no
file needs to be actually moved, so it shouldn't take more time than
what's required to acquire locks.
This query can be used to search for such relations:
SELECT ... FROM pg_class WHERE relkind IN ('p', 'I') AND reltablespace <> 0
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/16577-881633a9f9894fd5@postgresql.org
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
The point of this restriction is to avoid trying to substitute variables
into timestamp literal values, which may contain strings like '12:34'.
There is a good deal more that should be done to reduce pgbench's
tendency to substitute where it shouldn't. But this is sufficient to
solve the case complained of by Jaime Soler, and it's simple enough
to back-patch.
Back-patch to v11; before commit 9d36a3866, pgbench had a slightly
different definition of what a variable name is, and anyway it seems
unwise to change long-stable branches for this.
Fabien Coelho
Discussion: https://postgr.es/m/alpine.DEB.2.22.394.2006291740420.805678@pseudo
The documentation of pg_rewind mentioned the use of restore_command and
primary_conninfo as options available at startup to fetch missing WAL
segments that could be used to find the point of divergence for the
rewind. This is confusing because when finding the point of divergence
the target cluster is offline, so this option is not available.
Issue introduced by 878bd9a, so backpatch down to 9.6. The
documentation of 13 and HEAD was already right as this sentence has been
changed by a7e8ece when introducing -c/--restore-target-wal.
Reported-by: Amine Tengilimoglu
Discussion: https://postgr.es/m/CADTdw-w_0MP=iQrfizeU4QU5fcZb+w8P_oPeLL+WznWf0kbn3w@mail.gmail.com
Backpatch-through: 9.6
The behavior of cross-type comparisons among date/time data types was
not really explained anywhere. You could probably infer it if you
recognized the applicability of comments elsewhere about datatype
conversions, but it seems worthy of explicit documentation.
Per bug #16797 from Dana Burd.
Discussion: https://postgr.es/m/16797-f264b0b980b53b8b@postgresql.org
90fbf7c has taken care of that for HEAD. This includes the portion of
the fixes that applies to the documentation, where needed depending on
the branch.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20201227202604.GC26311@telsasoft.com
Backpatch-through: 9.5
The jsonb || jsonb operator arbitrarily rejected certain combinations
of scalar and non-scalar inputs, while being willing to concatenate
other combinations. This was of course quite undocumented. Rather
than trying to document it, let's just remove the restriction,
creating a uniform rule that unless we are handling an object-to-object
concatenation, non-array inputs are converted to one-element arrays,
resulting in an array-to-array concatenation. (This does not change
the behavior for any case that didn't throw an error before.)
Per complaint from Joel Jacobson. Back-patch to all supported branches.
Discussion: https://postgr.es/m/163099.1608312033@sss.pgh.pa.us
The separate "cd" command before invoking psql made sense (or at least
I thought so) when it was added in commit ed1939332. But 4e3a61635
removed the supporting text that explained when to use it, making it
just confusing. So drop it.
Also switch from four-dot to three-dot filler for the unsupplied
part of the path, since at least one person has read the four-dot
filler as a typo for "../..". And fix these/those inconsistency.
Discussion: https://postgr.es/m/160837647714.673.5195186835607800484@wrigleys.postgresql.org
It was not clear how COPY TO behaved with partitioning/inheritance
because the paragraphs were so far apart. Also reword to simplify.
Discussion: https://postgr.es/m/20201203211723.GR24052@telsasoft.com
Author: Justin Pryzby
Backpatch-through: 10
The SQL standard says that redundant unique constraints are disallowed,
but we long ago decided that throwing an error would be too
user-unfriendly, so we just drop redundant ones. The docs weren't very
clear about that though, as this behavior was only explained for PRIMARY
KEY vs UNIQUE, not UNIQUE vs UNIQUE.
While here, I couldn't resist doing some copy-editing and markup-fixing
on the adjacent text about INCLUDE options.
Per bug #16767 from Matthias vd Meent.
Discussion: https://postgr.es/m/16767-1714a2056ca516d0@postgresql.org
In a few places, the long-version options were listed before the
single-letter ones in the command summary of a few commands. This
didn't match other commands, and didn't match the option ordering later
in the same reference page.
Backpatch-through: 9.5
Because regular CREATE INDEX commands are independent, and there's no
logical data dependency, it's not immediately obvious that transactions
held by concurrent index builds on one table will block the second phase
of concurrent index creation on an unrelated table, so document this
caveat.
Backpatch this all the way back. In branch master, mention that only
some indexes are involved.
Author: James Coleman <jtc331@gmail.com>
Reviewed-by: David Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CAAaqYe994=PUrn8CJZ4UEo_S-FfRr_3ogERyhtdgHAb2WG_Ufg@mail.gmail.com
Checking for DocBook being installed was valuable when we were on the
OpenSP docs toolchain, because that was rather hard to get installed
fully. Nowadays, as long as you have xmllint and xsltproc installed,
you're good, because those programs will fetch the DocBook files off
the net at need. Moreover, testing this at configure time means that
a network access may well occur whether or not you have any interest
in building the docs later. That can be slow (typically 2 or 3
seconds, though much higher delays have been reported), and it seems
not very nice to be doing an off-machine access without warning, too.
Hence, drop the PGAC_CHECK_DOCBOOK probe, and adjust related
documentation. Without that macro, there's not much left of
config/docbook.m4 at all, so I just removed it.
Back-patch to v11, where we started to use xmllint in the
PGAC_CHECK_DOCBOOK probe.
Discussion: https://postgr.es/m/E2EE6B76-2D96-408A-B961-CAE47D1A86F0@yesql.se
Discussion: https://postgr.es/m/A55A7FC9-FA60-47FE-98B5-139CDC57CE6E@gmail.com
Through my misreading of what the existing code actually did,
commits 85c54287a et al. broke psql's behavior for the case where
"\c connstring" provides a password in the connstring. We should
use that password in such a case, but as of 85c54287a we ignored it
(and instead, prompted for a password).
Commit 94929f1cf fixed that in HEAD, but since I thought it was
cleaning up a longstanding misbehavior and not one I'd just created,
I didn't back-patch it.
Hence, back-patch the portions of 94929f1cf having to do with
password management. In addition to fixing the introduced bug,
this means that "\c -reuse-previous=on connstring" will allow
re-use of an existing connection's password if the connstring
doesn't change user/host/port. That didn't happen before, but
it seems like a bug fix, and anyway I'm loath to have significant
differences in this code across versions.
Also fix an error with the same root cause about whether or not to
override a connstring's setting of client_encoding. As of 85c54287a
we always did so; restore the previous behavior of overriding only
when stdin/stdout are a terminal and there's no environment setting
of PGCLIENTENCODING. (I find that definition a bit surprising, but
right now doesn't seem like the time to revisit it.)
Per bug #16746 from Krzysztof Gradek. As with the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/16746-44b30e2edf4335d4@postgresql.org
The documentation omitted the critical tidbit that a keyword-array entry
is simply ignored if its corresponding value-array entry is NULL or an
empty string; it will *not* override any previously-obtained value for
the parameter. (See conninfo_array_parse().) I'd supposed that would
force the setting back to default, which is what led me into bug #16746;
but it doesn't.
While here, I couldn't resist the temptation to do some copy-editing,
both in the description of PQconnectdbParams() and in the section
about connection URI syntax.
Discussion: https://postgr.es/m/931505.1606618746@sss.pgh.pa.us
These flags should be independent: in particular an index AM should
be able to say that it supports include columns without necessarily
supporting multiple key columns. The included-columns patch got
this wrong, possibly aided by the fact that it didn't bother to
update the documentation.
While here, clarify some text about amcanreturn, which was a little
vague about what should happen when amcanreturn reports that only
some of the index columns are returnable.
Noted while reviewing the SP-GiST included-columns patch, which
quite incorrectly (and unsafely) changed SP-GiST to claim
amcanmulticol = true as a workaround for this bug.
Backpatch to v11 where included columns were introduced.
This started with the intent to explain that range upper bounds
are exclusive, which previously you could only find out by reading
the CREATE TABLE man page. But I soon found that section 5.11
really could stand a fair amount of editorial attention. It's
apparently been revised several times without much concern for
overall flow, nor careful copy-editing.
Back-patch to v11, which is as far as the patch goes easily.
Per gripe from Edson Richter. Thanks to David Johnston for review.
Discussion: https://postgr.es/m/DM6PR13MB3988736CF8F5DC5720440231CFE60@DM6PR13MB3988.namprd13.prod.outlook.com
Document that though the history file content is marked as bytea, it is
the same a text, and neither is btyea-escaped or encoding converted.
Reported-by: Brar Piening
Discussion: https://postgr.es/m/6a1b9cd9-17e3-df67-be55-86102af6bdf5@gmx.de
Backpatch-through: 13 - 9.5 (not master)
Revert 59ab4ac32, as well as the followup fix 33862cb9c, in all
branches. We need to think a bit harder about what the behavior
of LOCK TABLE on views should be, and there's no time for that
before next week's releases. We'll take another crack at this
later.
Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
The intention in commit 491c029db was to require superuserness to
change the BYPASSRLS property, but the actual effect of the coding
in AlterRole() was to require superuserness to change anything at all
about a BYPASSRLS role. Other properties of a BYPASSRLS role should
be changeable under the same rules as for a normal role, though.
Fix that, and also take care of some documentation omissions related
to BYPASSRLS and REPLICATION role properties.
Tom Lane and Stephen Frost, per bug report from Wolfgang Walther.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/a5548a9f-89ee-3167-129d-162b5985fcf8@technowledgy.de
The restriction that only tables and views can be locked by LOCK TABLE
is quite arbitrary, since the underlying mechanism can lock any relation
type. Drop the restriction so that programs such as pg_dump can lock
all relations they're interested in, preventing schema changes that
could cause a dump to fail after expending much effort.
Backpatch to 9.5.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Wells Oliver <wells.oliver@gmail.com>
Discussion: https://postgr.es/m/20201021200659.GA32358@alvherre.pgsql
psql's \connect claims to be able to re-use previous connection
parameters, but in fact it only re-uses the database name, user name,
host name (and possibly hostaddr, depending on version), and port.
This is problematic for assorted use cases. Notably, pg_dump[all]
emits "\connect databasename" commands which we would like to have
re-use all other parameters. If such a script is loaded in a psql run
that initially had "-d connstring" with some non-default parameters,
those other parameters would be lost, potentially causing connection
failure. (Thus, this is the same kind of bug addressed in commits
a45bc8a4f and 8e5793ab6, although the details are much different.)
To fix, redesign do_connect() so that it pulls out all properties
of the old PGconn using PQconninfo(), and then replaces individual
properties in that array. In the case where we don't wish to re-use
anything, get libpq's default settings using PQconndefaults() and
replace entries in that, so that we don't need different code paths
for the two cases.
This does result in an additional behavioral change for cases where
the original connection parameters allowed multiple hosts, say
"psql -h host1,host2", and the \connect request allows re-use of the
host setting. Because the previous coding relied on PQhost(), it
would only permit reconnection to the same host originally selected.
Although one can think of scenarios where that's a good thing, there
are others where it is not. Moreover, that behavior doesn't seem to
meet the principle of least surprise, nor was it documented; nor is
it even clear it was intended, since that coding long pre-dates the
addition of multi-host support to libpq. Hence, this patch is content
to drop it and re-use the host list as given.
Per Peter Eisentraut's comments on bug #16604. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/16604-933f4b8791227b15@postgresql.org
When told to process all databases, clusterdb, reindexdb, and vacuumdb
would reconnect by replacing their --maintenance-db parameter with the
name of the target database. If that parameter is a connstring (which
has been allowed for a long time, though we failed to document that
before this patch), we'd lose any other options it might specify, for
example SSL or GSS parameters, possibly resulting in failure to connect.
Thus, this is the same bug as commit a45bc8a4f fixed in pg_dump and
pg_restore. We can fix it in the same way, by using libpq's rules for
handling multiple "dbname" parameters to add the target database name
separately. I chose to apply the same refactoring approach as in that
patch, with a struct to handle the command line parameters that need to
be passed through to connectDatabase. (Maybe someday we can unify the
very similar functions here and in pg_dump/pg_restore.)
Per Peter Eisentraut's comments on bug #16604. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/16604-933f4b8791227b15@postgresql.org
- Misc grammar and punctuation fixes.
- Stylistic cleanup: use spaces between function arguments and JSON fields
in examples. For example "foo(a,b)" -> "foo(a, b)". Add semicolon after
last END in a few PL/pgSQL examples that were missing them.
- Make sentence that talked about "..." and ".." operators more clear,
by avoiding to end the sentence with "..". That makes it look the same
as "..."
- Fix syntax description for HAVING: HAVING conditions cannot be repeated
Patch by Justin Pryzby, per Yaroslav Schekin's report. Backpatch to all
supported versions, to the extent that the patch applies easily.
Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com
The Windows documentation insists that every WSAStartup call should
have a matching WSACleanup call. However, if that ever had actual
relevance, it wasn't in this century. Every remotely-modern Windows
kernel is capable of cleaning up when a process exits without doing
that, and must be so to avoid resource leaks in case of a process
crash. Moreover, Postgres backends have done WSAStartup without
WSACleanup since commit 4cdf51e64 in 2004, and we've never seen any
indication of a problem with that.
libpq's habit of doing WSAStartup during connection start and
WSACleanup during shutdown is also rather inefficient, since a
series of non-overlapping connection requests leads to repeated,
quite expensive DLL unload/reload cycles. We document a workaround
for that (having the application call WSAStartup for itself), but
that's just a kluge. It's also worth noting that it's far from
uncommon for applications to exit without doing PQfinish, and
we've not heard reports of trouble from that either.
However, the real reason for acting on this is that recent
experiments by Alexander Lakhin show that calling WSACleanup
during PQfinish is triggering the symptom we occasionally see
that a process using libpq fails to emit expected stdio output.
Therefore, let's change libpq so that it calls WSAStartup only
once per process, during the first connection attempt, and never
calls WSACleanup at all.
While at it, get rid of the only other WSACleanup call in our code
tree, in pg_dump/parallel.c; that presumably is equally useless.
Back-patch of HEAD commit 7d00a6b2d.
Discussion: https://postgr.es/m/ac976d8c-03df-d6b8-025c-15a2de8d9af1@postgrespro.ru
Section 8.5.1.4, which defines these literals, made only a vague
reference to the fact that they might be evaluated too soon to be
safe in non-interactive contexts. Provide a more explicit caution
against misuse. Also, generalize the wording in the related tip in
section 9.9.4: while it clearly described this problem, it implied
(or really, stated outright) that the problem only applies to table
DEFAULT clauses.
Per gripe from Tijs van Dam. Back-patch to all supported branches.
Discussion: https://postgr.es/m/c2LuRv9BiRT3bqIo5mMQiVraEXey_25B4vUn0kDqVqilwOEu_iVF1tbtvLnyQK7yDG3PFaz_GxLLPil2SDkj1MCObNRVaac-7j1dVdFERk8=@thalex.com
Commit a97e85f2b caused "exceed the available area" warnings in PDF
builds. Fine-tune colwidth values to avoid that.
Back-patch to 9.6, like the prior patch. (This is of dubious value
before v13, since we were far from free of such warnings in older
branches. But we might as well keep the SGML looking the same in all
branches.)
Per buildfarm.
Previously it was documented that toast_tuple_target affected column
marked as only External or Extended. But this description is not correct
and toast_tuple_target affects also column marked as Main.
Back-patch to v11 where toast_tuple_target reloption was introduced.
Author: Shinya Okano
Reviewed-by: Tatsuhito Kasahara, Fujii Masao
Discussion: https://postgr.es/m/93f46e311a67422e89e770d236059817@oss.nttdata.com
Previously, a conversion such as
to_date('-44-02-01','YYYY-MM-DD')
would result in '0045-02-01 BC', as the code attempted to interpret
the negative year as BC, but failed to apply the correction needed
for our internal handling of BC years. Fix the off-by-one problem.
Also, arrange for the combination of a negative year and an
explicit "BC" marker to cancel out and produce AD. This is how
the negative-century case works, so it seems sane to do likewise.
Continue to read "year 0000" as 1 BC. Oracle would throw an error,
but we've accepted that case for a long time so I'm hesitant to
change it in a back-patch.
Per bug #16419 from Saeed Hubaishan. Back-patch to all supported
branches.
Dar Alathar-Yemen and Tom Lane
Discussion: https://postgr.es/m/16419-d8d9db0a7553f01b@postgresql.org
Explicitly mention that primary key constraints are also included in the
limitation that the constraint columns must be a superset of the partition key
columns.
Wording suggestion from Tom Lane.
Discussion: https://postgr.es/m/64062533.78364.1601415362244@mail.yahoo.com
Backpatch-through: 11, where unique constraints on partitioned tables were added
Previously the standby server didn't archive timeline history files
streamed from the primary even when archive_mode is set to "always",
while it archives the streamed WAL files. This could cause the PITR to
fail because there was no required timeline history file in the archive.
The cause of this issue was that walreceiver didn't mark those files as
ready for archiving.
This commit makes walreceiver mark those streamed timeline history
files as ready for archiving if archive_mode=always. Then the archiver
process archives the marked timeline history files.
Back-patch to all supported versions.
Reported-by: Grigory Smolkin
Author: Grigory Smolkin, Fujii Masao
Reviewed-by: David Zhang, Anastasia Lubennikova
Discussion: https://postgr.es/m/54b059d4-2b48-13a4-6f43-95a087c92367@postgrespro.ru
We have had multiple reports that point to the
'@colReorder=latn-digit' collation customization being buggy. We have
reported this to ICU and are waiting for a fix. In the meantime,
remove references to this from the documentation and replace it by
another reordering example. Apparently, many users have been picking
up this example specifically from the documentation.
Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Discussion: https://www.postgresql.org/message-id/flat/153201618542.1404.3611626898935613264%40wrigleys.postgresql.org
We were already raising an error for DROP INDEX CONCURRENTLY on a
partitioned table, albeit a different and confusing one:
ERROR: DROP INDEX CONCURRENTLY must be first action in transaction
Change that to throw a more comprehensible error:
ERROR: cannot drop partitioned index \"%s\" concurrently
Michael Paquier authored the test case for indexes on temporary
partitioned tables.
Backpatch to 11, where indexes on partitioned tables were added.
Reported-by: Jan Mussler <jan.mussler@zalando.de>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/16594-d2956ca909585067@postgresql.org
Back-patch key parts of 4c5cf5431 and 6ca547cf7 into stable branches.
I didn't touch pg_description entries here, so it's purely a docs
change; and I didn't fool with any examples either. The main point
is so that anyone who's wondering if factorial() exists in the stable
branches will be reassured.
Mark Dilger and John Naylor, with some adjustments by me
Discussion: https://postgr.es/m/BE2DF53D-251A-4E26-972F-930E523580E9@enterprisedb.com
The SimpleLruTruncate() header comment states the new coding rule. To
achieve this, add locktype "frozenid" and two LWLocks. This closes a
rare opportunity for data loss, which manifested as "apparent
wraparound" or "could not access status of transaction" errors. Data
loss is more likely in pg_multixact, due to released branches' thin
margin between multiStopLimit and multiWrapLimit. If a user's physical
replication primary logged ": apparent wraparound" messages, the user
should rebuild standbys of that primary regardless of symptoms. At less
risk is a cluster having emitted "not accepting commands" errors or
"must be vacuumed" warnings at some point. One can test a cluster for
this data loss by running VACUUM FREEZE in every database. Back-patch
to 9.5 (all supported versions).
Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
Up to now, upon receipt of a SIGTERM ("smart shutdown" command), the
postmaster has immediately killed all "optional" background processes,
and subsequently refused to launch new ones while it's waiting for
foreground client processes to exit. No doubt this seemed like an OK
policy at some point; but it's a pretty bad one now, because it makes
for a seriously degraded environment for the remaining clients:
* Parallel queries are killed, and new ones fail to launch. (And our
parallel-query infrastructure utterly fails to deal with the case
in a reasonable way --- it just hangs waiting for workers that are
not going to arrive. There is more work needed in that area IMO.)
* Autovacuum ceases to function. We can tolerate that for awhile,
but if bulk-update queries continue to run in the surviving client
sessions, there's eventually going to be a mess. In the worst case
the system could reach a forced shutdown to prevent XID wraparound.
* The bgwriter and walwriter are also stopped immediately, likely
resulting in performance degradation.
Hence, let's rearrange things so that the only immediate change in
behavior is refusing to let in new normal connections. Once the last
normal connection is gone, shut everything down as though we'd received
a "fast" shutdown. To implement this, remove the PM_WAIT_BACKUP and
PM_WAIT_READONLY states, instead staying in PM_RUN or PM_HOT_STANDBY
while normal connections remain. A subsidiary state variable tracks
whether or not we're letting in new connections in those states.
This also allows having just one copy of the logic for killing child
processes in smart and fast shutdown modes. I moved that logic into
PostmasterStateMachine() by inventing a new state PM_STOP_BACKENDS.
Back-patch to 9.6 where parallel query was added. In principle
this'd be a good idea in 9.5 as well, but the risk/reward ratio
is not as good there, since lack of autovacuum is not a problem
during typical uses of smart shutdown.
Per report from Bharath Rupireddy.
Patch by me, reviewed by Thomas Munro
Discussion: https://postgr.es/m/CALj2ACXAZ5vKxT9P7P89D87i3MDO9bfS+_bjMHgnWJs8uwUOOw@mail.gmail.com
Hostile objects located within the installation-time search_path could
capture references in an extension's installation or upgrade script.
If the extension is being installed with superuser privileges, this
opens the door to privilege escalation. While such hazards have existed
all along, their urgency increases with the v13 "trusted extensions"
feature, because that lets a non-superuser control the installation path
for a superuser-privileged script. Therefore, make a number of changes
to make such situations more secure:
* Tweak the construction of the installation-time search_path to ensure
that references to objects in pg_catalog can't be subverted; and
explicitly add pg_temp to the end of the path to prevent attacks using
temporary objects.
* Disable check_function_bodies within installation/upgrade scripts,
so that any security gaps in SQL-language or PL-language function bodies
cannot create a risk of unwanted installation-time code execution.
* Adjust lookup of type input/receive functions and join estimator
functions to complain if there are multiple candidate functions. This
prevents capture of references to functions whose signature is not the
first one checked; and it's arguably more user-friendly anyway.
* Modify various contrib upgrade scripts to ensure that catalog
modification queries are executed with secure search paths. (These
are in-place modifications with no extension version changes, since
it is the update process itself that is at issue, not the end result.)
Extensions that depend on other extensions cannot be made fully secure
by these methods alone; therefore, revert the "trusted" marking that
commit eb67623c9 applied to earthdistance and hstore_plperl, pending
some better solution to that set of issues.
Also add documentation around these issues, to help extension authors
write secure installation scripts.
Patch by me, following an observation by Andres Freund; thanks
to Noah Misch for review.
Security: CVE-2020-14350
In "High Availability, Load Balancing, and Replication" chapter,
certain descriptions of Pgpool-II were not correct at this point. It
does not need conflict resolution. Also "Multiple-Server Parallel
Query Execution" is not supported anymore.
Discussion: https://postgr.es/m/20200726.230128.53842489850344110.t-ishii%40sraoss.co.jp
Author: Tatsuo Ishii
Reviewed-by: Bruce Momjian
Backpatch-through: 9.5
Partitioned indexes are also registered in pg_inherits, but the
description of this catalog did not reflect that.
Author: Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/87k0ynj35y.fsf@wibble.ilmari.org
Backpatch-through: 11
TLS 1.3 uses a different way of specifying ciphers and a different
OpenSSL API. PostgreSQL currently does not support setting those
ciphers. For now, just document this. In the future, support for
this might be added somehow.
Reviewed-by: Jonathan S. Katz <jkatz@postgresql.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
The executor checks for this error, and so does the bootstrap catalog
loader, but we never checked for it in retail catalog manipulations.
The folly of that has now been exposed, so let's add assertions
checking it. Checking in CatalogTupleInsert[WithInfo] and
CatalogTupleUpdate[WithInfo] should be enough to cover this.
Back-patch to v10; the aforesaid functions didn't exist before that,
and it didn't seem worth adapting the patch to the oldest branches.
But given the risk of JIT crashes, I think we certainly need this
as far back as v11.
Pre-v13, we have to explicitly exclude pg_subscription.subslotname
and pg_subscription_rel.srsublsn from the checks, since they are
mismarked. (Even if we change our mind about applying BKI_FORCE_NULL
in the branch tips, it doesn't seem wise to have assertions that
would fire in existing databases.)
Discussion: https://postgr.es/m/298837.1595196283@sss.pgh.pa.us
This coding technique is unsafe, since we'd be accessing off the end
of the tuple if the field is null. SIGSEGV is pretty improbable, but
perhaps not impossible. Also, returning garbage for the LSN doesn't
seem like a great idea, even if callers aren't looking at it today.
Also update docs to point out explicitly that
pg_subscription.subslotname and pg_subscription_rel.srsublsn
can be null.
Perhaps we should mark these two fields BKI_FORCE_NULL, so that
they'd be correctly labeled in databases that are initdb'd in the
future. But we can't force that for existing databases, and on
balance it's not too clear that having a mix of different catalog
contents in the field would be wise.
Apply to v10 (where this code came in) through v12. Already
fixed in v13 and HEAD.
Discussion: https://postgr.es/m/732838.1595278439@sss.pgh.pa.us
Re-point comp.ai.genetic FAQ link to a more stable address.
Remove stale links to AIX documentation; we don't really need to
tell AIX users how to use their systems.
Remove stale links to HP documentation about SSL. We've had to
update those twice before, making it increasingly obvious that
HP does not intend them to be stable landing points. They're
not particularly authoritative, either. (This change effectively
reverts bbd3bdba3.)
Daniel Gustafsson and Álvaro Herrera, per a gripe from
Kyotaro Horiguchi. Back-patch, since these links are
just as dead in the back branches.
Discussion: https://postgr.es/m/20200709.161226.204639179120026914.horikyota.ntt@gmail.com
pg_stat_activity.query text is truncated at 1024 bytes. But previously
the document described that it's truncated at 1024 characters.
This was not accurate when considering multibyte characters.
Back-patch to v10 where this inaccurate description was added.
Author: Atsushi Torikoshi
Reviewed-by: Daniel Gustafsson, Fujii Masao
Discussion: https://postgr.es/m/cd5b49a5a14e887542f5f569c1c6bde2@oss.nttdata.com
After running GetForeignRelSize for a foreign table, adjust rel->tuples
to be at least as large as rel->rows. This prevents bizarre behavior
in estimate_num_groups() and perhaps other places, especially in the
scenario where rel->tuples is zero because pg_class.reltuples is
(suggesting that ANALYZE has never been run for the table). As things
stood, we'd end up estimating one group out of any GROUP BY on such a
table, whereas the default group-count estimate is more likely to result
in a sane plan.
Also, clarify in the documentation that GetForeignRelSize has the option
to override the rel->tuples value if it has a better idea of what to use
than what is in pg_class.reltuples.
Per report from Jeff Janes. Back-patch to all supported branches.
Patch by me; thanks to Etsuro Fujita for review
Discussion: https://postgr.es/m/CAMkU=1xNo9cnan+Npxgz0eK7394xmjmKg-QEm8wYG9P5-CcaqQ@mail.gmail.com
Warnings start 10M transactions before xidStopLimit, which is 11M
transactions before wraparound. The sample WARNING output showed a
value greater than 11M, and its HINT message predated commit
25ec228ef7. Hence, the sample was
impossible. Back-patch to 9.5 (all supported versions).
The IANA time zone folk have deprecated use of a "posixrules" file in
the tz database. While for now it's our choice whether to keep
supplying one in our own builds, installations built with
--with-system-tzdata will soon be needing to cope with that file not
being present, at least on some platforms.
This causes a problem for the horology test, which expected the
nonstandard POSIX zone spec "CST7CDT" to apply pre-2007 US daylight
savings rules. That does happen if the posixrules file supplies such
information, but otherwise the test produces undesired results.
To fix, add an explicit transition date rule that matches 2005 practice.
(We could alternatively have switched the test to use some real time
zone, but it seems useful to have coverage of this type of zone spec.)
While at it, update a documentation example that also relied on
"CST7CDT"; use a real-world zone name instead. Also, document why
the zone names EST5EDT, CST6CDT, MST7MDT, PST8PDT aren't subject to
similar failures when "posixrules" is missing.
Back-patch to all supported branches, since the hazard is the same
for all.
Discussion: https://postgr.es/m/1665379.1592581287@sss.pgh.pa.us
We'd glossed over most of this complexity for years, but it's hard
to avoid writing it all down now, so that we can explain what happens
when there's no "posixrules" file in the IANA time zone database.
That was at best a tiny minority situation till now, but it's likely
to become quite common in the future, so we'd better explain it.
Nonetheless, we don't really encourage people to use POSIX zone specs;
picking a named zone is almost always what you really want, unless
perhaps you're stuck with an out-of-date zone database. Therefore,
let's shove all this detail into an appendix.
Patch by me; thanks to Robert Haas for help with some awkward wording.
Discussion: https://postgr.es/m/1390.1562258309@sss.pgh.pa.us
Our documentation failed to point out that REPEATABLE READ is really
snapshot isolation, which might be important to some users. Point to
the standard reference paper for this complicated topic.
Likewise, add a reference to the VLDB paper about PostgreSQL SSI, for
technical information about our SSI implementation and how it compares
to S2PL.
While here, add a note about catalog access using a lower isolation
level, per recent user complaint.
Back-patch to all releases.
Reported-by: Kyle Kingsbury <aphyr@jepsen.io>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Tatsuo Ishii <ishii@sraoss.co.jp>
Discussion: https://postgr.es/m/db7b729d-0226-d162-a126-8a8ab2dc4443%40jepsen.io
Discussion: https://postgr.es/m/16454-9408996bb1750faf%40postgresql.org
In PostgreSQL 10, we stopped using System V semaphores on Linux
systems. Update the example we give of an error message from a
misconfigured system to show what people are most likely to see these
days.
Back-patch to 10, where PREFERRED_SEMAPHORES=UNNAMED_POSIX arrived.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGLmJUSwybaPQv39rB8ABpqJq84im2UjZvyUY4feYhpWMw%40mail.gmail.com
The description missed a comma and lacked an explanation of what happens
with REPLICA IDENTITY USING INDEX when the dependent index is dropped.
Author: Marina Polyakova
Reviewed-by: Daniel Gustafsson, Michael Paquier
Discussion: https://postgr.es/m/ad1a0badc32658b1bbb07aa312346a1d@postgrespro.ru
Backpatch-through: 9.5
Add a couple of lines to make it explicit that indexes, constraints,
triggers are added, removed, or left alone.
Backpatch to pg11.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20200421162038.GA18628@alvherre.pgsql
When a partition is detached, any triggers that had been cloned from its
parent were not properly disentangled from its parent triggers.
This resulted in triggers that could not be dropped because they
depended on the trigger in the trigger in the no-longer-parent table:
ALTER TABLE t DETACH PARTITION t1;
DROP TRIGGER trig ON t1;
ERROR: cannot drop trigger trig on table t1 because trigger trig on table t requires it
HINT: You can drop trigger trig on table t instead.
Moreover the table can no longer be re-attached to its parent, because
the trigger name is already taken:
ALTER TABLE t ATTACH PARTITION t1 FOR VALUES FROM (1)TO(2);
ERROR: trigger "trig" for relation "t1" already exists
The former is a bug introduced in commit 86f575948c. (The latter is
not necessarily a bug, but it makes the bug more uncomfortable.)
To avoid the complexity that would be needed to tell whether the trigger
has a local definition that has to be merged with the one coming from
the parent table, establish the behavior that the trigger is removed
when the table is detached.
Backpatch to pg11.
Author: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/20200408152412.GZ2228@telsasoft.com
The docs explained that a SHARE ROW EXCLUSIVE lock is needed on the
referenced table, but failed to say the same about the table being
altered. Since the page says that ACCESS EXCLUSIVE lock is taken
unless otherwise stated, this left readers with the wrong conclusion.
Discussion: https://postgr.es/m/834603375.3470346.1586482852542@mail.yahoo.com
CREATE GROUP is an exact alias for CREATE ROLE, and CREATE USER is
almost an exact alias, as can easily be confirmed by checking the
code. So the man page syntax descriptions ought to match up. The
last few additions of role options seem to have forgotten to update
create_group.sgml, though. Fix that, and add a naggy reminder to
create_role.sgml in hopes of not forgetting again.
Discussion: https://postgr.es/m/158647836143.655.9853963229391401576@wrigleys.postgresql.org
