PQnotifies() is defined to just process already-read data, not try to read
any more from the socket. (This is a debatable decision, perhaps, but I'm
hesitant to change longstanding library behavior.) The documentation has
long recommended calling PQconsumeInput() before PQnotifies() to ensure
that any already-arrived message would get absorbed and processed.
However, psql did not get that memo, which explains why it's not very
reliable about reporting notifications promptly.
Also, most (not quite all) callers called PQconsumeInput() just once before
a PQnotifies() loop. Taking this recommendation seriously implies that we
should do PQconsumeInput() before each call. This is more important now
that we have "payload" strings in notification messages than it was before;
that increases the probability of having more than one packet's worth
of notify messages. Hence, adjust code as well as documentation examples
to do it like that.
Back-patch to 9.5 to match related server fixes. In principle we could
probably go back further with these changes, but given lack of field
complaints I doubt it's worthwhile.
Discussion: https://postgr.es/m/CAOYf6ec-TmRYjKBXLLaGaB-jrd=mjG1Hzn1a1wufUAR39PQYhw@mail.gmail.com
Since the fixes for CVE-2018-1058, we've advised people to schema-qualify
function references in order to fix failures in code that executes under
a minimal search_path setting. However, that's insufficient to make the
single-argument form of unaccent() work, because it looks up the "unaccent"
text search dictionary using the search path.
The most expedient answer seems to be to remove the search_path dependency
by making it look in the same schema that the unaccent() function itself
is declared in. This will definitely work for the normal usage of this
function with the unaccent dictionary provided by the extension.
It's barely possible that there are people who were relying on the
search-path-dependent behavior to select other dictionaries with the same
name; but if there are any such people at all, they can still get that
behavior by writing unaccent('unaccent', ...), or possibly
unaccent('unaccent'::text::regdictionary, ...) if the lookup has to be
postponed to runtime.
Per complaint from Gunnlaugur Thor Briem. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/CAPs+M8LCex6d=DeneofdsoJVijaG59m9V0ggbb3pOH7hZO4+cQ@mail.gmail.com
pg_get_object_address and pg_identify_object_as_address are supposed
to be inverses, but they disagreed as to the names of the arguments
representing the textual form of an object address. Moreover, the
documented argument names didn't agree with reality at all, either
for these functions or pg_identify_object.
In HEAD and v11, I think we can get away with renaming the input
arguments of pg_get_object_address to match the outputs of
pg_identify_object_as_address. In theory that might break queries
using named-argument notation to call pg_get_object_address, but
it seems really unlikely that anybody is doing that, or that they'd
have much trouble adjusting if they were. In older branches, we'll
just live with the lack of consistency.
Aside from fixing the documentation of these functions to match reality,
I couldn't resist the temptation to do some copy-editing.
Per complaint from Jean-Pierre Pelletier. Back-patch to 9.5 where these
functions were introduced. (Before v11, this is a documentation change
only.)
Discussion: https://postgr.es/m/CANGqjDnWH8wsTY_GzDUxbt4i=y-85SJreZin4Hm8uOqv1vzRQA@mail.gmail.com
The previous description was unclear. Also add a third example, change
use of time zone acronyms to more verbose descriptions, and add a
mention that using 'time' with AT TIME ZONE uses the current time zone
rules.
Backpatch-through: 9.3
This table claimed that JOHAB could be used as a server encoding, which
was true originally but hasn't been true since 8.3. It also lacked
entries for EUC_JIS_2004 and SHIFT_JIS_2004.
JOHAB problem noted by Lars Kanis, the others by me.
Discussion: https://postgr.es/m/c0f514a1-b7a9-b9ea-1c02-c34aead56c06@greiz-reinsdorf.de
Mention that "Latest checkpoint location" will not match in pg_upgrade
if the standby server is still running during the upgrade, which is
possible. "Match" text first appeared in PG 9.5.
Reported-by: Paul Bonaud
Discussion: https://postgr.es/m/c7268794-edb4-1772-3bfd-04c54585c24e@trainline.com
Backpatch-through: 9.5
Historically, we looked up the target hostname in connectDBStart, so that
PQconnectPoll did not need to do DNS name resolution. The patches that
added multiple-target-host support to libpq preserved this division of
labor; but it's really nonsensical now, because it means that if any one
of the target hosts fails to resolve in DNS, the connection fails. That
negates the no-single-point-of-failure goal of the feature. Additionally,
DNS lookups aren't exactly cheap, but the code did them all even if the
first connection attempt succeeds.
Hence, rearrange so that PQconnectPoll does the lookups, and only looks
up a hostname when it's time to try that host. This does mean that
PQconnectPoll could block on a DNS lookup --- but if you wanted to avoid
that, you should be using hostaddr, as the documentation has always
specified. It seems fairly unlikely that any applications would really
care whether the lookup occurs inside PQconnectStart or PQconnectPoll.
In addition to calling out that fact explicitly, do some other minor
wordsmithing in the docs around the multiple-target-host feature.
Since this seems like a bug in the multiple-target-host feature,
backpatch to v10 where that was introduced. In the back branches,
avoid moving any existing fields of struct pg_conn, just in case
any third-party code is looking into that struct.
Tom Lane, reviewed by Fabien Coelho
Discussion: https://postgr.es/m/4913.1533827102@sss.pgh.pa.us
Commit 5f374fe7a attempted to turn the connect_timeout from an overall
maximum time limit into a per-host limit, but it didn't do a great job of
that. The timer would only get restarted if we actually detected timeout
within connectDBComplete(), not if we changed our attention to a new host
for some other reason. In that case the old timeout continued to run,
possibly causing a premature timeout failure for the new host.
Fix that, and also tweak the logic so that if we do get a timeout,
we advance to the next available IP address, not to the next host name.
There doesn't seem to be a good reason to assume that all the IP
addresses supplied for a given host name will necessarily fail the
same way as the current one. Moreover, this conforms better to the
admittedly-vague documentation statement that the timeout is "per
connection attempt". I changed that to "per host name or IP address"
to be clearer. (Note that reconnections to the same server, such as for
switching protocol version or SSL status, don't get their own separate
timeout; that was true before and remains so.)
Also clarify documentation about the interpretation of connect_timeout
values less than 2.
This seems like a bug, so back-patch to v10 where this logic came in.
Tom Lane, reviewed by Fabien Coelho
Discussion: https://postgr.es/m/5735.1533828184@sss.pgh.pa.us
5262f7a4fc have introduced parallel index scan. In order to estimate the
number of parallel workers, it adds extra argument to amcostestimate() index
access method API function. However, this extra argument was missed in the
documentation. This commit fixes that.
Discussion: https://postgr.es/m/4128fdb4-8b63-2e05-38f6-3125f8c27263%40lab.ntt.co.jp
Author: Tatsuro Yamada, Alexander Korotkov
Backpatch-through: 10
The amcheck documentation incorrectly claimed that its example query
verifies every catalog index in the database. In fact, the query only
verifies the 10 largest indexes (as determined by pg_class.relpages).
Adjust the description accordingly.
Backpatch: 10-, where contrib/amcheck was introduced.
The example output of pg_replication_slot is wrong. Correct it and make
the output stable by explicitly listing columns to output.
Author: Kyotaro Horiguchi <horiguchi.kyotaro@lab.ntt.co.jp>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20180731.190909.42582169.horiguchi.kyotaro@lab.ntt.co.jp
Previously, PQhost didn't return the connected host details when the
connection type was CHT_HOST_ADDRESS (i.e., via hostaddr). Instead, it
returned the complete host connection parameter (which could contain
multiple hosts) or the default host details, which was confusing and
arguably incorrect.
Change this to return the actually connected host or hostaddr
irrespective of the connection type. When hostaddr but no host was
specified, hostaddr is now returned. Never return the original host
connection parameter, and document that PQhost cannot be relied on
before the connection is established.
PQport is similarly changed to always return the active connection port
and never the original connection parameter.
Back-patch of commit 1944cdc982
into the v10 branch.
Author: Hari Babu <kommi.haribabu@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Before v10, we always searched ~/.pgpass using the host parameter,
and nothing else, to match to the "hostname" field of ~/.pgpass.
(However, null host or host matching DEFAULT_PGSOCKET_DIR was replaced by
"localhost".) In v10, this got broken by commit 274bb2b38, repaired by
commit bdac9836d, and broken again by commit 7b02ba62e; in the code
actually shipped, we'd search with hostaddr if both that and host were
specified --- though oddly, *not* if only hostaddr were specified.
Since this is directly contrary to the documentation, and not
backwards-compatible, it's clearly a bug.
However, the change wasn't totally without justification, even though it
wasn't done quite right, because the pre-v10 behavior has arguably been
buggy since we added hostaddr. If hostaddr is specified and host isn't,
the pre-v10 code will search ~/.pgpass for "localhost", and ship that
password off to a server that most likely isn't local at all. That's
unhelpful at best, and could be a security breach at worst.
Therefore, rather than just revert to that old behavior, let's define
the behavior as "search with host if provided, else with hostaddr if
provided, else search for localhost". (As before, a host name matching
DEFAULT_PGSOCKET_DIR is replaced by localhost.) This matches the
behavior of the actual connection code, so that we don't pick up an
inappropriate password; and it allows useful searches to happen when
only hostaddr is given.
While we're messing around here, ensure that empty elements within a
host or hostaddr list select the same behavior as a totally-empty
field would; for instance "host=a,,b" is equivalent to "host=a,/tmp,b"
if DEFAULT_PGSOCKET_DIR is /tmp. Things worked that way in some cases
already, but not consistently so, which contributed to the confusion
about what key ~/.pgpass would get searched with.
Update documentation accordingly, and also clarify some nearby text.
Back-patch to v10 where the host/hostaddr list functionality was
introduced.
Discussion: https://postgr.es/m/30805.1532749137@sss.pgh.pa.us
As written, this policy constrained only the post-image not the pre-image
of rows, meaning that users could delete other users' rows or take
ownership of such rows, contrary to what the docs claimed would happen.
We need two separate policies to achieve the documented effect.
While at it, try to explain what's happening a bit more fully.
Per report from Олег Самойлов. Back-patch to 9.5 where this was added.
Thanks to Stephen Frost for off-list discussion.
Discussion: https://postgr.es/m/3298321532002010@sas1-2b3c3045b736.qloud-c.yandex.net
Commit 5770172cb0 documented secure schema
usage, and that advice suffices for using unqualified names securely.
Document, in typeconv-func primarily, the additional issues that arise
with qualified names. Back-patch to 9.3 (all supported versions).
Reviewed by Jonathan S. Katz.
Discussion: https://postgr.es/m/20180721012446.GA1840594@rfd.leadboat.com
A collection of typos I happened to spot while reading code, as well as
grepping for common mistakes.
Backpatch to all supported versions, as applicable, to avoid conflicts
when backporting other commits in the future.
lca_inner() wasn't prepared for the possibility of getting no inputs.
Fix that, and make some cosmetic improvements to the code while at it.
Also, I thought the documentation of this function as returning the
"longest common prefix" of the paths was entirely misleading; it really
returns a path one shorter than the longest common prefix, for the typical
definition of "prefix". Don't use that term in the docs, and adjust the
examples to clarify what really happens.
This has been broken since its beginning, so back-patch to all supported
branches.
Per report from Hailong Li. Thanks to Pierre Ducroquet for diagnosing
and for the initial patch, though I whacked it around some and added
test cases.
Discussion: https://postgr.es/m/5b0d8e4f-f2a3-1305-d612-e00e35a7be66@qunar.com
Explain that you can use any integer expression for the "count" in
pl/pgsql's versions of FETCH/MOVE, unlike the SQL versions which only
allow a constant.
Remove the duplicate version of this para under MOVE. I don't see
a good reason to maintain two identical paras when we just said that
MOVE works exactly like FETCH.
Per Pavel Stehule, though I didn't use his text.
Discussion: https://postgr.es/m/CAFj8pRAcvSXcNdUGx43bOK1e3NNPbQny7neoTLN42af+8MYWEA@mail.gmail.com
When performing pg_rewind, the presence of a read-only file which is not
accessible for writes will cause a failure while processing. This can
cause the control file of the target data folder to be truncated,
causing it to not be reusable with a successive run.
Also, when pg_rewind fails mid-flight, there is likely no way to be able
to recover the target data folder anyway, in which case a new base
backup is the best option. A note is added in the documentation as
well about.
Reported-by: Christian H.
Author: Michael Paquier
Reviewed-by: Andrew Dunstan
Discussion: https://postgr.es/m/20180104200633.17004.16377%40wrigleys.postgresql.org
When these programs call pg_catalog.set_config, they need to check for
PGRES_TUPLES_OK instead of PGRES_COMMAND_OK. Fix for
5770172cb0.
Reported-by: Ideriha, Takeshi <ideriha.takeshi@jp.fujitsu.com>
search.cpan.org has been EOL'd, with metacpan.org being the official
replacement to which URLs now redirect. Update links to match the new
URL. Also update links to CPAN to use https as it will redirect from
http.
Author: Daniel Gustafsson
Discussion: https://postgr.es/m/B74C0219-6BA9-46E1-A524-5B9E8CD3BDB3@yesql.se
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
On Windows, it is sometimes important for corresponding malloc() and
free() calls to be made from the same DLL, since some build options can
result in multiple allocators being active at the same time. For that
reason we already provided PQfreemem(). This commit adds a similar
function for freeing string results allocated by the pgtypes library.
Author: Takayuki Tsunakawa
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8AD5D6%40G01JPEXMBYT05
Pavel Stehule's original patch had support for default namespace, but I
ripped it out before commit -- hence the docs were correct when written,
and I broke them by omission :-(. Remove the offending phrase.
Author: Daniel Gustafsson
Discussion: https://postgr.es/m/1550C5E5-FC70-4493-A226-AA137D831E8D@yesql.se
Since their introduction, partition trees have been a bit lossy
regarding temporary relations. Inheritance trees respect the following
patterns:
1) a child relation can be temporary if the parent is permanent.
2) a child relation can be temporary if the parent is temporary.
3) a child relation cannot be permanent if the parent is temporary.
4) The use of temporary relations also imply that when both parent and
child need to be from the same sessions.
Partitions share many similar patterns with inheritance, however the
handling of the partition bounds make the situation a bit tricky for
case 1) as the partition code bases a lot of its lookup code upon
PartitionDesc which does not really look after relpersistence. This
causes for example a temporary partition created by session A to be
visible by another session B, preventing this session B to create an
extra partition which overlaps with the temporary one created by A with
a non-intuitive error message. There could be use-cases where mixing
permanent partitioned tables with temporary partitions make sense, but
that would be a new feature. Partitions respect 2), 3) and 4) already.
It is a bit depressing to see those error checks happening in
MergeAttributes() whose purpose is different, but that's left as future
refactoring work.
Back-patch down to 10, which is where partitioning has been introduced,
except that default partitions do not apply there. Documentation also
includes limitations related to the use of temporary tables with
partition trees.
Reported-by: David Rowley
Author: Amit Langote, Michael Paquier
Reviewed-by: Ashutosh Bapat, Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/CAKJS1f94Ojk0og9GMkRHGt8wHTW=ijq5KzJKuoBoqWLwSVwGmw@mail.gmail.com
Documentation of word_similarity() and strict_word_similarity() functions
contains some vague wordings which could confuse users. This patch makes
those wordings more clear. word_similarity() was introduced in PostgreSQL 9.6,
and corresponding part of documentation needs to be backpatched.
Author: Bruce Momjian, Alexander Korotkov
Discussion: https://postgr.es/m/20180526165648.GB12510%40momjian.us
Backpatch: 9.6, where word_similarity() was introduced
kern.ipc.shm_use_phys is not a sysctl on OpenBSD, and SEMMAP is not
a kernel configuration option. These were probably copy pasteos from
when the documentation had a single paragraph for *BSD.
Author: Daniel Gustafsson <daniel@yesql.se>
OFFSET <x> ROWS FETCH FIRST <y> ROWS ONLY syntax is supposed to accept
<simple value specification>, which includes parameters as well as
literals. When this syntax was added all those years ago, it was done
inconsistently, with <x> and <y> being different subsets of the
standard syntax.
Rectify that by making <x> and <y> accept the same thing, and allowing
either a (signed) numeric literal or a c_expr there, which allows for
parameters, variables, and parenthesized arbitrary expressions.
Per bug #15200 from Lukas Eder.
Backpatch all the way, since this has been broken from the start.
Discussion: https://postgr.es/m/877enz476l.fsf@news-spur.riddles.org.uk
Discussion: http://postgr.es/m/152647780335.27204.16895288237122418685@wrigleys.postgresql.org
The "l" (ell) width spec means something in the corresponding scanf usage,
but not here. While modern POSIX says that applying "l" to "f" and other
floating format specs is a no-op, SUSv2 says it's undefined. Buildfarm
experience says that some old compilers emit warnings about it, and at
least one old stdio implementation (mingw's "ANSI" option) actually
produces wrong answers and/or crashes.
Discussion: https://postgr.es/m/21670.1526769114@sss.pgh.pa.us
Discussion: https://postgr.es/m/c085e1da-0d64-1c15-242d-c921f32e0d5c@dunslane.net
The description of the index property backward_scan was incorrect and
misleading; rectify.
Backpatch to 9.6 where the amutils functionality was introduced.
The set of functions that need parallel-safety adjustments isn't the
same in 9.6 as 10, so I shouldn't have blindly back-patched that list.
Adjust as needed. Also, provide examples of the commands to issue.
Previously, you could partition by a boolean column as long as you
spelled the bound values as string literals, for instance FOR VALUES
IN ('t'). The trouble with this is that ruleutils.c printed that as
FOR VALUES IN (TRUE), which is reasonable syntax but wasn't accepted by
the grammar. That results in dump-and-reload failures for such cases.
Apply a minimal fix that just causes TRUE and FALSE to be converted to
strings 'true' and 'false'. This is pretty grotty, but it's too late for
a more principled fix in v11 (to say nothing of v10). We should revisit
the whole issue of how partition bound values are parsed for v12.
Amit Langote
Discussion: https://postgr.es/m/e05c5162-1103-7e37-d1ab-6de3e0afaf70@lab.ntt.co.jp
In particular, the requirement to have SELECT privilege for the initial
table copy was previously not documented.
Author: Shinoda, Noriyoshi <noriyoshi.shinoda@hpe.com>
Section 10.5 didn't say explicitly that multiple UNIONs are resolved
pairwise. Since the resolution algorithm is described as taking any
number of inputs, readers might well think that a query like
"select x union select y union select z" would be resolved by
considering x, y, and z in one resolution step. But that's not what
happens (and I think that behavior is per SQL spec). Add an example
clarifying this point.
Per bug #15129 from Philippe Beaudoin.
Discussion: https://postgr.es/m/152196085023.32649.9916472370480121694@wrigleys.postgresql.org
Extension scripts begin execution with pg_catalog at the front of the
search path, so type names reliably refer to pg_catalog. Remove these
superfluous qualifications. Earlier <programlisting> of this <sect1>
already omitted them. Back-patch to 9.3 (all supported versions).
If a view lacks an INSTEAD OF trigger, DML on it can only work by rewriting
the command into a command on the underlying base table(s). Then we will
fire triggers attached to those table(s), not those for the view. This
seems appropriate from a consistency standpoint, but nowhere was the
behavior explicitly documented, so let's do that.
There was some discussion of throwing an error or warning if a statement
trigger is created on a view without creating a row INSTEAD OF trigger.
But a simple implementation of that would result in dump/restore ordering
hazards. Given that it's been like this all along, and we hadn't heard
a complaint till now, a documentation improvement seems sufficient.
Per bug #15106 from Pu Qun. Back-patch to all supported branches.
Discussion: https://postgr.es/m/152083391168.1215.16892140713507052796@wrigleys.postgresql.org
Autovacuum's 'workitem' request queue is of limited size, so requests
can fail if they arrive more quickly than autovacuum can process them.
Emit a log message when this happens, to provide better visibility of
this.
Backpatch to 10. While this represents an API change for
AutoVacuumRequestWork, that function is not yet prepared to deal with
external modules calling it, so there doesn't seem to be any risk (other
than log spam, that is.)
Author: Masahiko Sawada
Reviewed-by: Fabrízio Mello, Ildar Musin, Álvaro Herrera
Discussion: https://postgr.es/m/CAD21AoB1HrQhp6_4rTyHN5kWEJCEsG8YzsjZNt-ctoXSn5Uisw@mail.gmail.com
The changes in the CREATE POLICY man page from commit
87c2a17fee triggered a stylesheet bug that
created some warning messages and incorrect output. This installs a
workaround.
Also improve the whitespace a bit so it looks better.
The LIKE INCLUDING ALL clause to CREATE TABLE intuitively indicates
cloning of extended statistics on the source table, but it failed to do
so. Patch it up so that it does. Also include an INCLUDING STATISTICS
option to the LIKE clause, so that the behavior can be requested
individually, or excluded individually.
While at it, reorder the INCLUDING options, both in code and in docs, in
alphabetical order which makes more sense than feature-implementation
order that was previously used.
Backpatch this to Postgres 10, where extended statistics were
introduced, because this is seen as an oversight in a fresh feature
which is better to get consistent from the get-go instead of changing
only in pg11.
In pg11, comments on statistics objects are cloned too. In pg10 they
are not, because I (Álvaro) was too coward to change the parse node as
required to support it. Also, in pg10 I chose not to renumber the
parser symbols for the various INCLUDING options in LIKE, for the same
reason. Any corresponding user-visible changes (docs) are backpatched,
though.
Reported-by: Stephen Froehlich
Author: David Rowley
Reviewed-by: Álvaro Herrera, Tomas Vondra
Discussion: https://postgr.es/m/CY1PR0601MB1927315B45667A1B679D0FD5E5EF0@CY1PR0601MB1927.namprd06.prod.outlook.com
In PostgreSQL 9.5, the documentation for pg_stat_replication was moved,
so some of the links pointed to an appropriate location.
Author: Maksim Milyutin <milyutinma@gmail.com>
The ability to create like-named objects in different schemas opens up
the potential for users to change the behavior of other users' queries,
maliciously or accidentally. When you connect to a PostgreSQL server,
you should remove from your search_path any schema for which a user
other than yourself or superusers holds the CREATE privilege. If you do
not, other users holding CREATE privilege can redefine the behavior of
your commands, causing them to perform arbitrary SQL statements under
your identity. "SET search_path = ..." and "SELECT
pg_catalog.set_config(...)" are not vulnerable to such hijacking, so one
can use either as the first command of a session. As special
exceptions, the following client applications behave as documented
regardless of search_path settings and schema privileges: clusterdb
createdb createlang createuser dropdb droplang dropuser ecpg (not
programs it generates) initdb oid2name pg_archivecleanup pg_basebackup
pg_config pg_controldata pg_ctl pg_dump pg_dumpall pg_isready
pg_receivewal pg_recvlogical pg_resetwal pg_restore pg_rewind pg_standby
pg_test_fsync pg_test_timing pg_upgrade pg_waldump reindexdb vacuumdb
vacuumlo. Not included are core client programs that run user-specified
SQL commands, namely psql and pgbench. PostgreSQL encourages non-core
client applications to do likewise.
Document this in the context of libpq connections, psql connections,
dblink connections, ECPG connections, extension packaging, and schema
usage patterns. The principal defense for applications is "SELECT
pg_catalog.set_config('search_path', '', false)", and the principal
defense for databases is "REVOKE CREATE ON SCHEMA public FROM PUBLIC".
Either one is sufficient to prevent attack. After a REVOKE, consider
auditing the public schema for objects named like pg_catalog objects.
Authors of SECURITY DEFINER functions use some of the same defenses, and
the CREATE FUNCTION reference page already covered them thoroughly.
This is a good opportunity to audit SECURITY DEFINER functions for
robust security practice.
Back-patch to 9.3 (all supported versions).
Reviewed by Michael Paquier and Jonathan S. Katz. Reported by Arseniy
Sharoglazov.
Security: CVE-2018-1058
This is mostly cosmetic, but it might fix build failures, on some
platform, when copying from the documentation.
Back-patch to 9.3 (all supported versions).
Since we now support the server side handler for git over https (so
we're no longer using the "dumb protocol"), make https the primary
choice for cloning the repository, and the git protocol the secondary
choice.
In passing, also change the links to git-scm.com from http to https.
Reviewed by Stefan Kaltenbrunner and David G. Johnston
Technically, pg_upgrade's --old-datadir and --new-datadir are
configuration directories, not necessarily data directories. This is
reflected in the 'postgres' manual page, so do the same for pg_upgrade.
Reported-by: Yves Goergen
Bug: 14898
Discussion: https://postgr.es/m/20171110220912.31513.13322@wrigleys.postgresql.org
Backpatch-through: 10
pg_hba_file_rules erroneously reported this as scram-sha256. Fix that.
To avoid future errors and confusion, also adjust documentation links
and internal symbols to have a separator between "sha" and "256".
Reported-by: Christophe Courtois <christophe.courtois@dalibo.com>
Author: Michael Paquier <michael.paquier@gmail.com>
Document how to properly create root and intermediate certificates using
v3_ca extensions and where to place intermediate certificates so they
are properly transferred to the remote side with the leaf certificate to
link to the remote root certificate. This corrects docs that used to
say that intermediate certificates must be stored with the root
certificate.
Also add instructions on how to create root, intermediate, and leaf
certificates.
Discussion: https://postgr.es/m/20180116002238.GC12724@momjian.us
Reviewed-by: Michael Paquier
Backpatch-through: 9.3
~> (cube, int) operator was especially designed for knn-gist search.
However, it appears that knn-gist search can't work correctly with current
behavior of this operator when dataset contains cubes of variable
dimensionality. In this case, the same value of second operator argument
can point to different dimension depending on dimensionality of particular cube.
Such behavior is incompatible with gist indexing of cubes, and knn-gist doesn't
work correctly for it.
This patch changes behavior of ~> (cube, int) operator by introducing dimension
numbering where value of second argument unambiguously identifies number of
dimension. With new behavior, this operator can be correctly supported by
knn-gist. Relevant changes to cube operator class are also included.
Backpatch to v9.6 where operator was introduced.
Since behavior of ~> (cube, int) operator is changed, depending entities
must be refreshed after upgrade. Such as, expression indexes using this
operator must be reindexed, materialized views must be rebuilt, stored
procedures and client code must be revised to correctly use new behavior.
That should be mentioned in release notes.
Noticed by: Tomas Vondra
Author: Alexander Korotkov
Reviewed by: Tomas Vondra, Andrey Borodin
Discussion: https://www.postgresql.org/message-id/flat/a9657f6a-b497-36ff-e56-482a2c7e3292@2ndquadrant.com
These functions are stated to be Oracle-compatible, but they weren't.
Yugo Nagata noticed that while our code returns zero for a zero or
negative fourth parameter (occur_index), Oracle throws an error.
Further testing by me showed that there was also a discrepancy in the
interpretation of a negative third parameter (beg_index): Oracle thinks
that a negative beg_index indicates the last place where the target
substring can *begin*, whereas our code thinks it is the last place
where the target can *end*.
Adjust the sample code to behave like Oracle in both these respects.
Also change it to be a CDATA[] section, simplifying copying-and-pasting
out of the documentation source file. And fix minor problems in the
introductory comment, which wasn't very complete or accurate.
Back-patch to all supported branches. Although this patch only touches
documentation, we should probably call it out as a bug fix in the next
minor release notes, since users who have adopted the functions will
likely want to update their versions.
Yugo Nagata and Tom Lane
Discussion: https://postgr.es/m/20171229191705.c0b43a8c.nagata@sraoss.co.jp
rewriteTargetListUD's processing is dependent on the relkind of the query's
target table. That was fine at the time it was made to act that way, even
for queries on inheritance trees, because all tables in an inheritance tree
would necessarily be plain tables. However, the 9.5 feature addition
allowing some members of an inheritance tree to be foreign tables broke the
assumption that rewriteTargetListUD's output tlist could be applied to all
child tables with nothing more than column-number mapping. This led to
visible failures if foreign child tables had row-level triggers, and would
also break in cases where child tables belonged to FDWs that used methods
other than CTID for row identification.
To fix, delay running rewriteTargetListUD until after the planner has
expanded inheritance, so that it is applied separately to the (already
mapped) tlist for each child table. We can conveniently call it from
preprocess_targetlist. Refactor associated code slightly to avoid the
need to heap_open the target relation multiple times during
preprocess_targetlist. (The APIs remain a bit ugly, particularly around
the point of which steps scribble on parse->targetList and which don't.
But avoiding such scribbling would require a change in FDW callback APIs,
which is more pain than it's worth.)
Also fix ExecModifyTable to ensure that "tupleid" is reset to NULL when
we transition from rows providing a CTID to rows that don't. (That's
really an independent bug, but it manifests in much the same cases.)
Add a regression test checking one manifestation of this problem, which
was that row-level triggers on a foreign child table did not work right.
Back-patch to 9.5 where the problem was introduced.
Etsuro Fujita, reviewed by Ildus Kurbangaliev and Ashutosh Bapat
Discussion: https://postgr.es/m/20170514150525.0346ba72@postgrespro.ru
wal_receiver_timeout, wal_receiver_status_interval and
wal_retrieve_retry_interval configuration parameters affect the logical rep
worker, but previously only wal_receiver_status_interval was not mentioned
as such parameter in the doc.
Back-patch to v10 where logical rep was added.
Author: Masahiko Sawada
Discussion: https://www.postgresql.org/message-id/CAD21AoBUnuH_UsnKXyPCsCR7EAMamW0sSb6a7=WgiQRpnMAp5w@mail.gmail.com
Previously, any attempt to request a 3.x protocol version other than
3.0 would lead to a hard connection failure, which made the minor
protocol version really no different from the major protocol version
and precluded gentle protocol version breaks. Instead, when the
client requests a 3.x protocol version where x is greater than 0, send
the new NegotiateProtocolVersion message to convey that we support
only 3.0. This makes it possible to introduce new minor protocol
versions without requiring a connection retry when the server is
older.
In addition, if the startup packet includes name/value pairs where
the name starts with "_pq_.", assume that those are protocol options,
not GUCs. Include those we don't support (i.e. all of them, at
present) in the NegotiateProtocolVersion message so that the client
knows they were not understood. This makes it possible for the
client to request previously-unsupported features without bumping
the protocol version at all; the client can tell from the server's
response whether the option was understood.
It will take some time before servers that support these new
facilities become common in the wild; to speed things up and make
things easier for a future 3.1 protocol version, back-patch to all
supported releases.
Robert Haas and Badrul Chowdhury
Discussion: http://postgr.es/m/BN6PR21MB0772FFA0CBD298B76017744CD1730@BN6PR21MB0772.namprd21.prod.outlook.com
Discussion: http://postgr.es/m/30788.1498672033@sss.pgh.pa.us
In the v10 branch, also back-patch the effects of 1ff01b390 and c29c57890
on these files, to reduce future maintenance issues. (I'd do it further
back, except that the 9.X branches differ anyway due to xlog-to-wal
link tag renaming.)
This makes the produced HTML anchors upper case, making it backward
compatible with the previous (9.6) build system.
Reported-by: Thomas Kellerer <spam_eater@gmx.net>
The change made by commit 906bfcad7 means that if you're writing
a parenthesized column list in UPDATE ... SET, but that column list
is only one column, you now need to write ROW(expression) on the
righthand side, not just a parenthesized expression. This was an
intentional change for spec compatibility and potential future
expansion of the possibilities for the RHS, but I'd neglected to
document it as a compatibility issue, figuring that hardly anyone
would bother with parenthesized syntax for a single target column.
I was wrong, as shown by questions from Justin Pryzby, Adam Brusselback,
and others. Move the release note item into the compatibility section
and point out the behavior change for a single target column.
Discussion: https://postgr.es/m/CAMjNa7cDLzPcs0xnRpkvqmJ6Vb6G3EH8CYGp9ZBjXdpFfTz6dg@mail.gmail.com
The GRANT reference page, which lists the default privileges for new
objects, failed to mention that USAGE is granted by default for data
types and domains. As a lesser sin, it also did not specify anything
about the initial privileges for sequences, FDWs, foreign servers,
or large objects. Fix that, and add a comment to acldefault() in the
probably vain hope of getting people to maintain this list in future.
Noted by Laurenz Albe, though I editorialized on the wording a bit.
Back-patch to all supported branches, since they all have this behavior.
Discussion: https://postgr.es/m/1507620895.4152.1.camel@cybertec.at
Document better how to create custom collations and what locale strings
ICU accepts. Explain the ICU examples in more detail. Also update the
text on the CREATE COLLATION reference page a bit to take ICU more into
account.
This reverts commit 15bc038f9, along with the followon commits 1635e80d3
and 984c92074 that tried to clean up the problems exposed by bug #14825.
The result was incomplete because it failed to address parallel-query
requirements. With 10.0 release so close upon us, now does not seem like
the time to be adding more code to fix that. I hope we can un-revert this
code and add the missing parallel query support during the v11 cycle.
Back-patch to v10.
Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
It drops objects outside information_schema that depend on objects
inside information_schema. For example, it will drop a user-defined
view if the view query refers to information_schema.
Discussion: https://postgr.es/m/20170831025345.GE3963697@rfd.leadboat.com
The blacklist mechanism added by the preceding commit directly fixes
most of the practical cases that the same-transaction test was meant
to cover. What remains is use-cases like
begin;
create type e as enum('x');
alter type e add value 'y';
-- use 'y' somehow
commit;
However, because the same-transaction test is heuristic, it fails on
small variants of that, such as renaming the type or changing its
owner. Rather than try to explain the behavior to users, let's
remove it and just have a rule that the newly added value can't be
used before being committed, full stop. Perhaps later it will be
worth the implementation effort and overhead to have a more accurate
test for type-was-created-in-this-transaction. We'll wait for some
field experience with v10 before deciding to do that.
Back-patch to v10.
Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
Commit 15bc038f9 allowed ALTER TYPE ADD VALUE to be executed inside
transaction blocks, by disallowing the use of the added value later
in the same transaction, except under limited circumstances. However,
the test for "limited circumstances" was heuristic and could reject
references to enum values that were created during CREATE TYPE AS ENUM,
not just later. This breaks the use-case of restoring pg_dump scripts
in a single transaction, as reported in bug #14825 from Balazs Szilfai.
We can improve this by keeping a "blacklist" table of enum value OIDs
created by ALTER TYPE ADD VALUE during the current transaction. Any
visible-but-uncommitted value whose OID is not in the blacklist must
have been created by CREATE TYPE AS ENUM, and can be used safely
because it could not have a lifespan shorter than its parent enum type.
This change also removes the restriction that a renamed enum value
can't be used before being committed (unless it was on the blacklist).
Andrew Dunstan, with cosmetic improvements by me.
Back-patch to v10.
Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
Explain more about how the different password authentication methods and
the password_encryption settings relate to each other, give some
upgrading advice, and set a better link from the release notes.
Reviewed-by: Jeff Janes <jeff.janes@gmail.com>
GRANT, REVOKE, and some allied commands allow the noise word GROUP
before a role name (cf. grantee production in gram.y). This option
does not exist elsewhere, but it had nonetheless snuck into the
documentation for ALTER ROLE, ALTER USER, and CREATE SCHEMA.
Seems to be a copy-and-pasteo in commit 31eae6028, which did expand the
syntax choices here, but not in that way. Back-patch to 9.5 where that
came in.
Discussion: https://postgr.es/m/20170916123750.8885.66941@wrigleys.postgresql.org
Since rsync 3.0.0 (released in 2008), the default way to enumerate
changes was changed in a way that makes it less likely that the hardlink
sync mode works. Since the whole point of the documented procedure is
for the hardlinks to work, change our docs to suggest using the
backwards compatibility switch.
Add item about number of times statement-level triggers will be fired.
Rearrange the compatibility items into (what seems to me) a less
random ordering.
Commit 0f79440fb introduced mechanism to keep AFTER STATEMENT triggers
from firing more than once per statement, which was formerly possible
if more than one FK enforcement action had to be applied to a given
table. Add a similar mechanism for BEFORE STATEMENT triggers, so that
we don't have the unexpected situation of firing BEFORE STATEMENT
triggers more often than AFTER STATEMENT.
As with the previous patch, back-patch to v10.
Discussion: https://postgr.es/m/22315.1505584992@sss.pgh.pa.us
I noticed that there were exactly no complete examples of use of
a transition table in a trigger function, and no clear description
of just how you'd do it either. Improve that.
The standard says that all changes of the same kind (insert, update, or
delete) caused in one table by a single SQL statement should be reported
in a single transition table; and by that, they mean to include foreign key
enforcement actions cascading from the statement's direct effects. It's
also reasonable to conclude that if the standard had wCTEs, they would say
that effects of wCTEs applying to the same table as each other or the outer
statement should be merged into one transition table. We weren't doing it
like that.
Hence, arrange to merge tuples from multiple update actions into a single
transition table as much as we can. There is a problem, which is that if
the firing of FK enforcement triggers and after-row triggers with
transition tables is interspersed, we might need to report more tuples
after some triggers have already seen the transition table. It seems like
a bad idea for the transition table to be mutable between trigger calls.
There's no good way around this without a major redesign of the FK logic,
so for now, resolve it by opening a new transition table each time this
happens.
Also, ensure that AFTER STATEMENT triggers fire just once per statement,
or once per transition table when we're forced to make more than one.
Previous versions of Postgres have allowed each FK enforcement query
to cause an additional firing of the AFTER STATEMENT triggers for the
referencing table, but that's certainly not per spec. (We're still
doing multiple firings of BEFORE STATEMENT triggers, though; is that
something worth changing?)
Also, forbid using transition tables with column-specific UPDATE triggers.
The spec requires such transition tables to show only the tuples for which
the UPDATE trigger would have fired, which means maintaining multiple
transition tables or else somehow filtering the contents at readout.
Maybe someday we'll bother to support that option, but it looks like a
lot of trouble for a marginal feature.
The transition tables are now managed by the AfterTriggers data structures,
rather than being directly the responsibility of ModifyTable nodes. This
removes a subtransaction-lifespan memory leak introduced by my previous
band-aid patch 3c4359521.
In passing, refactor the AfterTriggers data structures to reduce the
management overhead for them, by using arrays of structs rather than
several parallel arrays for per-query-level and per-subtransaction state.
I failed to resist the temptation to do some copy-editing on the SGML
docs about triggers, above and beyond merely documenting the effects
of this patch.
Back-patch to v10, because we don't want the semantics of transition
tables to change post-release.
Patch by me, with help and review from Thomas Munro.
Discussion: https://postgr.es/m/20170909064853.25630.12825@wrigleys.postgresql.org
Document that rsync is an _optional_ way to upgrade standbys, suggest
rsync option --dry-run, and mention a way of upgrading one standby from
another using rsync. Also clarify some instructions by specifying if
they operate on the old or new clusters.
Reported-by: Stephen Frost, Magnus Hagander
Discussion: https://postgr.es/m/20170914191250.GB6595@momjian.us
Backpatch-through: 9.5
The documentation claimed that one should send
"pg_same_as_startup_message" as the user name in the SCRAM messages, but
this did not match the actual implementation, so remove it.
This makes it clear that pg_upgrade standby upgrade instructions should
only be used in link mode, adds examples, and explains how rsync works
with links.
Reported-by: Andreas Joseph Krogh
Discussion: https://postgr.es/m/VisenaEmail.6c.c0e592c5af4ef0a2.15e785dcb61@tc7-visena
Backpatch-through: 9.5
We already had a psql variable VERSION that shows the verbose form of
psql's own version. Add VERSION_NAME to show the short form (e.g.,
"11devel") and VERSION_NUM to show the numeric form (e.g., 110000).
Also add SERVER_VERSION_NAME and SERVER_VERSION_NUM to show the short and
numeric forms of the server's version. (We'd probably add SERVER_VERSION
with the verbose string if it were readily available; but adding another
network round trip to get it seems too expensive.)
The numeric forms, in particular, are expected to be useful for scripting
purposes, now that psql can do conditional tests.
Back-patch of commit 9ae9d8c154.
Fabien Coelho, reviewed by Pavel Stehule
Discussion: https://postgr.es/m/alpine.DEB.2.20.1704020917220.4632@lancre
Commit 9915de6c1c changed the default behavior of
DROP_REPLICATION_SLOT so that it would wait until any session holding
the slot active would release it, instead of raising an error. But
users are already depending on the original behavior, so revert to it by
default and add a WAIT option to invoke the new behavior.
Per complaint from Simone Gotti, in
Discussion: https://postgr.es/m/CAEvsy6Wgdf90O6pUvg2wSVXL2omH5OPC-38OD4Zzgk-FXavj3Q@mail.gmail.com
Previously, the parallel executor logic did reinitialization of shared
state within the ExecReScan code for parallel-aware scan nodes. This is
problematic, because it means that the ExecReScan call has to occur
synchronously (ie, during the parent Gather node's ReScan call). That is
swimming very much against the tide so far as the ExecReScan machinery is
concerned; the fact that it works at all today depends on a lot of fragile
assumptions, such as that no plan node between Gather and a parallel-aware
scan node is parameterized. Another objection is that because ExecReScan
might be called in workers as well as the leader, hacky extra tests are
needed in some places to prevent unwanted shared-state resets.
Hence, let's separate this code into two functions, a ReInitializeDSM
call and the ReScan call proper. ReInitializeDSM is called only in
the leader and is guaranteed to run before we start new workers.
ReScan is returned to its traditional function of resetting only local
state, which means that ExecReScan's usual habits of delaying or
eliminating child rescan calls are safe again.
As with the preceding commit 7df2c1f8d, it doesn't seem to be necessary
to make these changes in 9.6, which is a good thing because the FDW and
CustomScan APIs are impacted.
Discussion: https://postgr.es/m/CAA4eK1JkByysFJNh9M349u_nNjqETuEnY_y1VUc_kJiU0bxtaQ@mail.gmail.com
The formatting of the sidebar element didn't carry over to the new tool
chain. Instead of inventing a whole new way of dealing with it, just
convert the one use to a "note".
As long as PQntuples, PQgetvalue, etc, use "int" for row numbers, we're
pretty much stuck with this limitation. The documentation formerly stated
that the result of PQntuples "might overflow on 32-bit operating systems",
which is just nonsense: that's not where the overflow would happen, and
if you did reach an overflow it would not be on a 32-bit machine, because
you'd have OOM'd long since.
Discussion: https://postgr.es/m/CA+FnnTxyLWyjY1goewmJNxC==HQCCF4fKkoCTa9qR36oRAHDPw@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
Users can still create them themselves. Instead, document Unicode TR 35
collation options for ICU, so users can create all this themselves.
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Install language+region combinations even if they are not distinct from
the language's base locale. This gives better long-term stability of
the set of predefined locales and makes the predefined locales less
implementation-dependent and more practical for users.
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
This became possible by commit
6c2003f8a1. This just makes pg_dump aware
of it and updates the documentation.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Also create PDF bookmarks/ToC entries for subsections of reference
pages. This was a regression from the previous jadetex-based build.
Reported-by: Erik Rijkers <er@xs4all.nl>
Since PostgreSQL 9.6, rolreplication no longer determines whether a role
can run pg_start_backup() and pg_stop_backup(), so remove that.
Add that this attribute determines whether a role can create and drop
replication slots.
Reported-by: Fujii Masao <masao.fujii@gmail.com>
Many places that mentioned only Gather should also mention Gather
Merge, or should be phrased in a more neutral way. Be more clear
about the fact that max_parallel_workers_per_gather affects the number
of workers the planner may want to use. Fix a typo. Explain how
Gather Merge works. Adjust wording around parallel scans to be a bit
more clear. Adjust wording around parallel-restricted operations for
the fact that uncorrelated subplans are no longer restricted.
Patch by me, reviewed by Erik Rijkers
Discussion: http://postgr.es/m/CA+TgmoZsTjgVGn=ei5ht-1qGFKy_m1VgB3d8+Rg304hz91N5ww@mail.gmail.com
Similar to what was fixed in commit 9915de6c1c for replication slots,
but this time it's related to replication origins: DROP SUBSCRIPTION
attempts to drop the replication origin, but that fails if the
replication worker process hasn't yet marked it unused. This causes
failures in the buildfarm:
ERROR: could not drop replication origin with OID 1, in use by PID 34069
Like the aforementioned commit, fix by having the process running DROP
SUBSCRIPTION sleep until the worker marks the the replication origin
struct as free. This uses a condition variable on each replication
origin shmem state struct, so that the session trying to drop can sleep
and expect to be awakened by the process keeping the origin open.
Also fix a SGML markup in the previous commit.
Discussion: https://postgr.es/m/20170808001433.rozlseaf4m2wkw3n@alvherre.pgsql
In commit 9915de6c1c, we introduced a new wait point for replication
slots and incorrectly labelled it as wait event PG_WAIT_LOCK. That's
wrong, so invent an appropriate new wait event instead, and document it
properly.
While at it, fix numerous other problems in the vicinity:
- two different walreceiver wait events were being mixed up in a single
wait event (which wasn't documented either); split it out so that they
can be distinguished, and document the new events properly.
- ParallelBitmapPopulate was documented but didn't exist.
- ParallelBitmapScan was not documented (I think this should be called
"ParallelBitmapScanInit" instead.)
- Logical replication wait events weren't documented
- various symbols had been added in dartboard order in various places.
Put them in alphabetical order instead, as was originally intended.
Discussion: https://postgr.es/m/20170808181131.mu4fjepuh5m75cyq@alvherre.pgsql
Commit 3eefc51053 claimed to make
pg_user_mappings enforce the qualifications user_mapping_options had
been enforcing, but its removal of a longstanding restriction left them
distinct when the current user is the subject of a mapping yet has no
server privileges. user_mapping_options emits no rows for such a
mapping, but pg_user_mappings includes full umoptions. Change
pg_user_mappings to show null for umoptions. Back-patch to 9.2, like
the above commit.
Reviewed by Tom Lane. Reported by Jeff Janes.
Security: CVE-2017-7547
Some authentication methods allowed it, others did not. In the client-side,
libpq does not even try to authenticate with an empty password, which makes
using empty passwords hazardous: an administrator might think that an
account with an empty password cannot be used to log in, because psql
doesn't allow it, and not realize that a different client would in fact
allow it. To clear that confusion and to be be consistent, disallow empty
passwords in all authentication methods.
All the authentication methods that used plaintext authentication over the
wire, except for BSD authentication, already checked that the password
received from the user was not empty. To avoid forgetting it in the future
again, move the check to the recv_password_packet function. That only
forbids using an empty password with plaintext authentication, however.
MD5 and SCRAM need a different fix:
* In stable branches, check that the MD5 hash stored for the user does not
not correspond to an empty string. This adds some overhead to MD5
authentication, because the server needs to compute an extra MD5 hash, but
it is not noticeable in practice.
* In HEAD, modify CREATE and ALTER ROLE to clear the password if an empty
string, or a password hash that corresponds to an empty string, is
specified. The user-visible behavior is the same as in the stable branches,
the user cannot log in, but it seems better to stop the empty password from
entering the system in the first place. Secondly, it is fairly expensive to
check that a SCRAM hash doesn't correspond to an empty string, because
computing a SCRAM hash is much more expensive than an MD5 hash by design,
so better avoid doing that on every authentication.
We could clear the password on CREATE/ALTER ROLE also in stable branches,
but we would still need to check at authentication time, because even if we
prevent empty passwords from being stored in pg_authid, there might be
existing ones there already.
Reported by Jeroen van der Ham, Ben de Graaff and Jelte Fennema.
Security: CVE-2017-7546
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
Supporting ICU 4.2 seems useful because it ships with CentOS 6.
Versions before ICU 4.6 don't support pkg-config, so document an
installation method without using pkg-config.
In ICU 4.2, ucol_getKeywordsForLocale() sometimes returns values that
will not be accepted by uloc_toLanguageTag(). Skip loading keyword
variants in that version.
Reported-by: Victor Wagner <vitus@wagner.pp.ru>
Per a report from AP, it's not that hard to exhaust the supply of
bitmap pages if you create a table with a hash index and then insert a
few billion rows - and then you start getting errors when you try to
insert additional rows. In the particular case reported by AP,
there's another fix that we can make to improve recycling of overflow
pages, which is another way to avoid the error, but there may be other
cases where this problem happens and that fix won't help. So let's
buy ourselves as much headroom as we can without rearchitecting
anything.
The comments claim that the old limit was 64GB, but it was really
only 32GB, because we didn't use all the bits in the page for bitmap
bits - only the largest power of 2 that could fit after deducting
space for the page header and so forth. Thus, we have 4kB per page
for bitmap bits, not 8kB. The new limit is thus actually 8 times the
old *real* limit but only 4 times the old *purported* limit.
Since this breaks on-disk compatibility, bump HASH_VERSION. We've
already done this earlier in this release cycle, so this doesn't cause
any incremental inconvenience for people using pg_upgrade from
releases prior to v10. However, users who use pg_upgrade to reach
10beta3 or later from 10beta2 or earlier will need to REINDEX any hash
indexes again.
Amit Kapila and Robert Haas
Discussion: http://postgr.es/m/20170704105728.mwb72jebfmok2nm2@zip.com.au
ALTER USER ... SET did not support all the syntax variants of ALTER ROLE
... SET. Fix that, and to avoid further deviations of this kind, unify
many the grammar rules for ROLE/USER/GROUP commands.
Reported-by: Pavel Golub <pavel@microolap.com>
FlightAware is still maintaining this, and indeed is seemingly being
more active with it than the pgtclng fork is. List both, for the
time being anyway.
In the back branches, also back-port commit e20f679f6 and other
recent updates to the client-interfaces list. I think these are
probably of current interest to users of back branches. I did
not touch the list of externally maintained PLs in the back
branches, though. Those are much more likely to be server version
sensitive, and I don't know which of these PLs work all the way back.
Discussion: https://postgr.es/m/20170730162612.1449.58796@wrigleys.postgresql.org
1024 bits is considered weak these days, but OpenSSL always passes 1024 as
the key length to the tmp_dh callback. All the code to handle other key
lengths is, in fact, dead.
To remedy those issues:
* Only include hard-coded 2048-bit parameters.
* Set the parameters directly with SSL_CTX_set_tmp_dh(), without the
callback
* The name of the file containing the DH parameters is now a GUC. This
replaces the old hardcoded "dh1024.pem" filename. (The files for other
key lengths, dh512.pem, dh2048.pem, etc. were never actually used.)
This is not a new problem, but it doesn't seem worth the risk and churn to
backport. If you care enough about the strength of the DH parameters on
old versions, you can create custom DH parameters, with as many bits as you
wish, and put them in the "dh1024.pem" file.
Per report by Nicolas Guini and Damian Quiroga. Reviewed by Michael Paquier.
Discussion: https://www.postgresql.org/message-id/CAMxBoUyjOOautVozN6ofzym828aNrDjuCcOTcCquxjwS-L2hGQ@mail.gmail.com
Previously the docs just said "5.8 or later". Experimentation shows
that while you can build on Unix from a git checkout with 5.8.0,
compiling recent PL/Perl requires at least 5.8.1, and you won't be
able to run the TAP tests with less than 5.8.3 because that's when
they added "prove". (I do not have any information on just what the
MSVC build scripts require.)
Since all these versions are quite ancient, let's not split hairs
in the docs, but just say that 5.8.3 is the minimum requirement.
Discussion: https://postgr.es/m/16894.1501392088@sss.pgh.pa.us
If the user modifies a view that has CHECK OPTIONs and this gets
translated into a modification to an underlying relation which happens
to be a foreign table, the check options should be enforced. In the
normal code path, that was happening properly, but it was not working
properly for "direct" modification because the whole operation gets
pushed to the remote side in that case and we never have an option to
enforce the constraint against individual tuples. Fix by disabling
direct modification when there is a need to enforce CHECK OPTIONs.
Etsuro Fujita, reviewed by Kyotaro Horiguchi and by me.
Discussion: http://postgr.es/m/f8a48f54-6f02-9c8a-5250-9791603171ee@lab.ntt.co.jp
The descriptions of PQserverVersion and PQlibVersion hadn't been updated
for the new two-part version-numbering approach. Fix that.
In passing, remove some trailing whitespace elsewhere in the file.
Previously, UNBOUNDED meant no lower bound when used in the FROM list,
and no upper bound when used in the TO list, which was OK for
single-column range partitioning, but problematic with multiple
columns. For example, an upper bound of (10.0, UNBOUNDED) would not be
collocated with a lower bound of (10.0, UNBOUNDED), thus making it
difficult or impossible to define contiguous multi-column range
partitions in some cases.
Fix this by using MINVALUE and MAXVALUE instead of UNBOUNDED to
represent a partition column that is unbounded below or above
respectively. This syntax removes any ambiguity, and ensures that if
one partition's lower bound equals another partition's upper bound,
then the partitions are contiguous.
Also drop the constraint prohibiting finite values after an unbounded
column, and just document the fact that any values after MINVALUE or
MAXVALUE are ignored. Previously it was necessary to repeat UNBOUNDED
multiple times, which was needlessly verbose.
Note: Forces a post-PG 10 beta2 initdb.
Report by Amul Sul, original patch by Amit Langote with some
additional hacking by me.
Discussion: https://postgr.es/m/CAAJ_b947mowpLdxL3jo3YLKngRjrq9+Ej4ymduQTfYR+8=YAYQ@mail.gmail.com
Claiming that NATURAL JOIN is equivalent to CROSS JOIN when there are
no common column names is only strictly correct if it's an inner join;
you can't say e.g. CROSS LEFT JOIN. Better to explain it as meaning
JOIN ON TRUE, instead. Per a suggestion from David Johnston.
Discussion: https://postgr.es/m/CAKFQuwb+mYszQhDS9f_dqRrk1=Pe-S6D=XMkAXcDf4ykKPmgKQ@mail.gmail.com
Also fix two other issues, while we're at it:
* In error message on connection failure, if multiple network addresses
were given as the host option, as in "host=127.0.0.1,127.0.0.2", the
error message printed the address twice.
* If there were many more ports than hostnames, the error message would
always claim that there was one port too many, even if there was more than
one. For example, if you gave 2 hostnames and 5 ports, the error message
claimed that you gave 2 hostnames and 3 ports.
Discussion: https://www.postgresql.org/message-id/10badbc6-4d5a-a769-623a-f7ada43e14dd@iki.fi
Commit e9c81b601 changed this, but missed updating the documentation.
The adjacent claim that we use TAP tests only in src/bin seems pretty
obsolete as well. Minor other copy-editing.
Original wording had confusingly vague antecedent for "they", so replace
that with a more repetitive but clearer formulation. In passing, make the
link to the installation requirements section more specific. Per gripe
from Martin Mai, though this is not the fix he initially proposed.
Discussion: https://postgr.es/m/CAN_NWRu-cWuNaiXUjV3m4H-riWURuPW=j21bSaLADs6rjjzXgQ@mail.gmail.com
If an operation being waited for does not complete within the timeout,
then exit with a nonzero exit status. This was previously handled
inconsistently.
Update the documentation for \pset to mention
columns|linestyle|pager_min_lines. Add various mentions of \pset
command equivalences that were previously inconsistent.
Author: Дилян Палаузов <dpa-postgres@aegee.org>
Update the documentation a bit to include that logical replication as
well as other and third-party replication clients can participate in
synchronous replication.
Buildfarm evidence shows that TCP_KEEPALIVE_THRESHOLD doesn't exist
after all on Solaris < 11. This means we need to take positive action to
prevent the TCP_KEEPALIVE code path from being taken on that platform.
I've chosen to limit it with "&& defined(__darwin__)", since it's unclear
that anyone else would follow Apple's precedent of spelling the symbol
that way.
Also, follow a suggestion from Michael Paquier of eliminating code
duplication by defining a couple of intermediate symbols for the
socket option.
In passing, make some effort to reduce the number of translatable messages
by replacing "setsockopt(foo) failed" with "setsockopt(%s) failed", etc,
throughout the affected files. And update relevant documentation so
that it doesn't claim to provide an exhaustive list of the possible
socket option names.
Like the previous commit (f0256c774), back-patch to all supported branches.
Discussion: https://postgr.es/m/20170627163757.25161.528@wrigleys.postgresql.org
pg_import_system_collations() refused to create any ICU collations if
the current database's encoding didn't support ICU. This is wrongheaded:
initdb must initialize pg_collation in an encoding-independent way
since it might be used in other databases with different encodings.
The reason for the restriction seems to be that get_icu_locale_comment()
used icu_from_uchar() to convert the UChar-format display name, and that
unsurprisingly doesn't know what to do in unsupported encodings.
But by the same token that the initial catalog contents must be
encoding-independent, we can't allow non-ASCII characters in the comment
strings. So we don't really need icu_from_uchar() here: just check for
Unicode codes outside the ASCII range, and if there are none, the format
conversion is trivial. If there are some, we can simply not install the
comment. (In my testing, this affects only Norwegian Bokmål, which has
given us trouble before.)
For paranoia's sake, also check for non-ASCII characters in ICU locale
names, and skip such locales, as we do for libc locales. I don't
currently have a reason to believe that this will ever reject anything,
but then again the libc maintainers should have known better too.
With just the import changes, ICU collations can be found in pg_collation
in databases with unsupported encodings. This resulted in more or less
clean failures at runtime, but that's not how things act for unsupported
encodings with libc collations. Make it work the same as our traditional
behavior for libc collations by having collation lookup take into account
whether is_encoding_supported_by_icu().
Adjust documentation to match. Also, expand Table 23.1 to show which
encodings are supported by ICU.
catversion bump because of likely change in pg_collation/pg_description
initial contents in ICU-enabled builds.
Discussion: https://postgr.es/m/20c74bc3-d6ca-243d-1bbc-12f17fa4fe9a@gmail.com
The comparison with the target rows on the subscriber side was done with
datumIsEqual(), which can have false negatives. For instance, it didn't
work reliably for text columns. So use the equality operator provided
by the type cache instead.
Also add more user documentation about replica identity requirements.
Reported-by: Tatsuo Ishii <ishii@sraoss.co.jp>
Marco Atzeri reported that initdb would fail if "locale -a" reported
the same locale name more than once. All previous versions of Postgres
implicitly de-duplicated the results of "locale -a", but the rewrite
to move the collation import logic into C had lost that property.
It had also lost the property that locale names matching built-in
collation names were silently ignored.
The simplest way to fix this is to make initdb run the function in
if-not-exists mode, which means that there's no real use-case for
non if-not-exists mode; we might as well just drop the boolean argument
and simplify the function's definition to be "add any collations not
already known". This change also gets rid of some odd corner cases
caused by the fact that aliases were added in if-not-exists mode even
if the function argument said otherwise.
While at it, adjust the behavior so that pg_import_system_collations()
doesn't spew "collation foo already exists, skipping" messages during a
re-run; that's completely unhelpful, especially since there are often
hundreds of them. And make it return a count of the number of collations
it did add, which seems like it might be helpful.
Also, re-integrate the previous coding's property that it would make a
deterministic selection of which alias to use if there were conflicting
possibilities. This would only come into play if "locale -a" reports
multiple equivalent locale names, say "de_DE.utf8" and "de_DE.UTF-8",
but that hardly seems out of the question.
In passing, fix incorrect behavior in pg_import_system_collations()'s
ICU code path: it neglected CommandCounterIncrement, which would result
in failures if ICU returns duplicate names, and it would try to create
comments even if a new collation hadn't been created.
Also, reorder operations in initdb so that the 'ucs_basic' collation
is created before calling pg_import_system_collations() not after.
This prevents a failure if "locale -a" were to report a locale named
that. There's no reason to think that that ever happens in the wild,
but the old coding would have survived it, so let's be equally robust.
Discussion: https://postgr.es/m/20c74bc3-d6ca-243d-1bbc-12f17fa4fe9a@gmail.com
Startup process is displayed in pg_stat_activity, noted by Yugo Nagata.
Transactions can be resolved at end of recovery.
Author: Yugo Nagata, with addition by me
When materialized views were added, psql's \d commands were made to
treat them as a separate object category ... but not everyplace in the
documentation or comments got the memo.
Noted by David Johnston. Back-patch to 9.3 where matviews came in.
Discussion: https://postgr.es/m/CAKFQuwb27M3VXRhHErjCpkWwN9eKThbqWb1=trtoXi9_ejqPXQ@mail.gmail.com
It was unsafe to instruct users to start/stop the server after
pg_upgrade was run but before the standby servers were rsync'ed. The
new instructions avoid this.
RELEASE NOTES: This fix should be mentioned in the minor release notes.
Reported-by: Dmitriy Sarafannikov and Sergey Burladyan
Discussion: https://postgr.es/m/87wp8o506b.fsf@seb.koffice.internal
Backpatch-through: 9.5, where standby server upgrade instructions first appeared
Previously we required every exported transaction to have an xid
assigned. That was used to check that the exporting transaction is
still running, which in turn is needed to guarantee that that
necessary rows haven't been removed in between exporting and importing
the snapshot.
The exported xid caused unnecessary problems with logical decoding,
because slot creation has to wait for all concurrent xid to finish,
which in turn serializes concurrent slot creation. It also
prohibited snapshots to be exported on hot-standby replicas.
Instead export the virtual transactionid, which avoids the unnecessary
serialization and the inability to export snapshots on standbys. This
changes the file name of the exported snapshot, but since we never
documented what that one means, that seems ok.
Author: Petr Jelinek, slightly editorialized by me
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/f598b4b8-8cd7-0d54-0939-adda763d8c34@2ndquadrant.com
When we reimplemented SRFs in commit 69f4b9c85, our initial choice was
to allow the behavior to vary from historical practice in cases where a
SRF call appeared within a conditional-execution construct (currently,
only CASE or COALESCE). But that was controversial to begin with, and
subsequent discussion has resulted in a consensus that it's better to
throw an error instead of executing the query differently from before,
so long as we can provide a reasonably clear error message and a way to
rewrite the query.
Hence, add a parser mechanism to allow detection of such cases during
parse analysis. The mechanism just requires storing, in the ParseState,
a pointer to the set-returning FuncExpr or OpExpr most recently emitted
by parse analysis. Then the parsing functions for CASE and COALESCE can
detect the presence of a SRF in their arguments by noting whether this
pointer changes while analyzing their arguments. Furthermore, if it does,
it provides a suitable error cursor location for the complaint. (This
means that if there's more than one SRF in the arguments, the error will
point at the last one to be analyzed not the first. While connoisseurs of
parsing behavior might find that odd, it's unlikely the average user would
ever notice.)
While at it, we can also provide more specific error messages than before
about some pre-existing restrictions, such as no-SRFs-within-aggregates.
Also, reject at parse time cases where a NULLIF or IS DISTINCT FROM
construct would need to return a set. We've never supported that, but the
restriction is depended on in more subtle ways now, so it seems wise to
detect it at the start.
Also, provide some documentation about how to rewrite a SRF-within-CASE
query using a custom wrapper SRF.
It turns out that the information_schema.user_mapping_options view
contained an instance of exactly the behavior we're now forbidding; but
rewriting it makes it more clear and safer too.
initdb forced because of user_mapping_options change.
Patch by me, with error message suggestions from Alvaro Herrera and
Andres Freund, pursuant to a complaint from Regina Obe.
Discussion: https://postgr.es/m/000001d2d5de$d8d66170$8a832450$@pcorp.us
The exact numbers don't matter, since they are examples, but it was
looking quite dated.
For the target version, we now automatically substitute the current
major version. The updated example source version should be good for a
couple of years.
Clarify in the syntax synopsis that partition bound values must be
exactly numeric literals or string literals; previously it
said "bound_literal" which was defined nowhere.
Replace confusing --- and, I think, incorrect in detail --- definition
of how range bounds work with a reference to row-wise comparison plus
a concrete example (which I stole from Robert Haas).
Minor copy-editing in the same area.
Discussion: https://postgr.es/m/30475.1496005465@sss.pgh.pa.us
Discussion: https://postgr.es/m/28106.1496041449@sss.pgh.pa.us
Consistent with what we do for indexes, we shouldn't try to record
dependencies on collation OID 0 or the default collation OID (which
is pinned). Also, the fact that indcollation and partcollation can
contain zero OIDs when the data type is not collatable should be
documented.
Amit Langote, per a complaint from me.
Discussion: http://postgr.es/m/CA+Tgmoba5mtPgM3NKfG06vv8na5gGbVOj0h4zvivXQwLw8wXXQ@mail.gmail.com
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and
throws a PANIC if so. At that point, only walsenders are still
active, so one might think this could not happen, but walsenders can
also generate WAL, for instance in BASE_BACKUP and logical decoding
related commands (e.g. via hint bits). So they can trigger this panic
if such a command is run while the shutdown checkpoint is being
written.
To fix this, divide the walsender shutdown into two phases. First,
checkpointer, itself triggered by postmaster, sends a
PROCSIG_WALSND_INIT_STOPPING signal to all walsenders. If the backend
is idle or runs an SQL query this causes the backend to shutdown, if
logical replication is in progress all existing WAL records are
processed followed by a shutdown. Otherwise this causes the walsender
to switch to the "stopping" state. In this state, the walsender will
reject any further replication commands. The checkpointer begins the
shutdown checkpoint once all walsenders are confirmed as
stopping. When the shutdown checkpoint finishes, the postmaster sends
us SIGUSR2. This instructs walsender to send any outstanding WAL,
including the shutdown checkpoint record, wait for it to be replicated
to the standby, and then exit.
Author: Andres Freund, based on an earlier patch by Michael Paquier
Reported-By: Fujii Masao, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
Backpatch: 9.4, where logical decoding was introduced
This reverts commit 086221cf6b, which
was made to master only.
The approach implemented in the above commit has some issues. While
those could easily be fixed incrementally, doing so would make
backpatching considerably harder, so instead first revert this patch.
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
There was a grammar ambiguity between SET PUBLICATION name REFRESH and
SET PUBLICATION SKIP REFRESH, because SKIP is not a reserved word. To
resolve that, fold the refresh choice into the WITH options. Refreshing
is the default now.
Reported-by: tushar <tushar.ahuja@enterprisedb.com>
Previously the changes to the "data" part of the sequence, i.e. the
one containing the current value, were not transactional, whereas the
definition, including minimum and maximum value were. That leads to
odd behaviour if a schema change is rolled back, with the potential
that out-of-bound sequence values can be returned.
To avoid the issue create a new relfilenode fork whenever ALTER
SEQUENCE is executed, similar to how TRUNCATE ... RESTART IDENTITY
already is already handled.
This commit also makes ALTER SEQUENCE RESTART transactional, as it
seems to be too confusing to have some forms of ALTER SEQUENCE behave
transactionally, some forms not. This way setval() and nextval() are
not transactional, but DDL is, which seems to make sense.
This commit also rolls back parts of the changes made in 3d092fe540
and f8dc1985f as they're now not needed anymore.
Author: Andres Freund
Discussion: https://postgr.es/m/20170522154227.nvafbsm62sjpbxvd@alap3.anarazel.de
Backpatch: Bug is in master/v10 only
On some platforms, -fpic fails for sufficiently large shared libraries.
We've mostly not hit that boundary yet, but there are some extensions
such as Citus and pglogical where it's becoming a problem. A bit of
research suggests that the penalty for -fPIC is small, in the
single-digit-percentage range --- and there's none at all on popular
platforms such as x86_64. So let's just default to -fPIC everywhere
and provide one less thing for extension developers to worry about.
Per complaint from Christoph Berg. Back-patch to all supported branches.
(I did not bother to touch the recently-removed Makefiles for sco and
unixware in the back branches, though. We'd have no way to test that
it doesn't break anything on those platforms.)
Discussion: https://postgr.es/m/20170529155850.qojdfrwkkqnjb3ap@msg.df7cb.de
pg_resetwal (formerly pg_resetxlog) doesn't insist on finding a matching
version number in pg_control, and that seems like an important thing to
preserve since recovering from corrupt pg_control is a prime reason to
need to run it. However, that means you can try to run it against a
data directory of a different major version, which is at best useless
and at worst disastrous. So as to provide some protection against that
type of pilot error, inspect PG_VERSION at startup and refuse to do
anything if it doesn't match. PG_VERSION is read-only after initdb,
so it's unlikely to get corrupted, and even if it were corrupted it would
be easy to fix by hand.
This hazard has been there all along, so back-patch to all supported
branches.
Michael Paquier, with some kibitzing by me
Discussion: https://postgr.es/m/f4b8eb91-b934-8a0d-b3cc-68f06e2279d1@enterprisedb.com
Left-justify these comments, remove committer names, remove SGML markup
that was randomly added to some of them. Aside from being more consistent
with previous practice, this keeps the lines shorter than 80 characters,
improving readability in standard terminal windows.
The cash_div_intX functions applied rint() to the result of the division.
That's not merely useless (because the result is already an integer) but
it causes precision loss for values larger than 2^52 or so, because of
the forced conversion to float8.
On the other hand, the cash_mul_fltX functions neglected to apply rint() to
their multiplication results, thus possibly causing off-by-one outputs.
Per C standard, arithmetic between any integral value and a float value is
performed in float format. Thus, cash_mul_flt4 and cash_div_flt4 produced
answers good to only about six digits, even when the float value is exact.
We can improve matters noticeably by widening the float inputs to double.
(It's tempting to consider using "long double" arithmetic if available,
but that's probably too much of a stretch for a back-patched fix.)
Also, document that cash_div_intX operators truncate rather than round.
Per bug #14663 from Richard Pistole. Back-patch to all supported branches.
Discussion: https://postgr.es/m/22403.1495223615@sss.pgh.pa.us
This is more secure, and saves a redirect since we no longer accept
plain HTTP connections on the website.
References in code comments should probably be updated too, but
that doesn't seem to need back-patching, whereas this does.
Also, in the 9.2 branch, remove suggestion that you can get the
source code via FTP, since that service will be shut down soon.
Daniel Gustafsson, with a few additional changes by me
Discussion: https://postgr.es/m/9A2C89A7-0BB8-41A8-B288-8B7BD09D7D44@yesql.se
If one host in a multi-host connection string times out, move on to
the next specified host instead of giving up entirely.
Takayuki Tsunakawa, reviewed by Michael Paquier. I added
a minor adjustment to the documentation.
Discussion: http://postgr.es/m/0A3221C70F24FB45833433255569204D1F6F42F5@G01JPEXMBYT05
This seemed like a good idea originally because there's no way to mark
a range partition as accepting NULL, but that now seems more like a
current limitation than something we want to lock down for all time.
For example, there's a proposal to add the notion of a default
partition which accepts all rows not otherwise routed, which directly
conflicts with the idea that a range-partitioned table should never
allow nulls anywhere. So let's change this while we still can, by
putting the NOT NULL test into the partition constraint instead of
changing the column properties.
Amit Langote and Robert Haas, reviewed by Amit Kapila
Discussion: http://postgr.es/m/8e2dd63d-c6fb-bb74-3c2b-ed6d63629c9d@lab.ntt.co.jp
In 1753b1b027, the pg_sequence system
catalog was introduced. This made sequence metadata changes
transactional, while the actual sequence values are still behaving
nontransactionally. This requires some refinement in how ALTER
SEQUENCE, which operates on both, locks the sequence and the catalog.
The main problems were:
- Concurrent ALTER SEQUENCE causes "tuple concurrently updated" error,
caused by updates to pg_sequence catalog.
- Sequence WAL writes and catalog updates are not protected by same
lock, which could lead to inconsistent recovery order.
- nextval() disregarding uncommitted ALTER SEQUENCE changes.
To fix, nextval() and friends now lock the sequence using
RowExclusiveLock instead of AccessShareLock. ALTER SEQUENCE locks the
sequence using ShareRowExclusiveLock. This means that nextval() and
ALTER SEQUENCE block each other, and ALTER SEQUENCE on the same sequence
blocks itself. (This was already the case previously for the OWNER TO,
RENAME, and SET SCHEMA variants.) Also, rearrange some code so that the
entire AlterSequence is protected by the lock on the sequence.
As an exception, use reduced locking for ALTER SEQUENCE ... RESTART.
Since that is basically a setval(), it does not require the full locking
of other ALTER SEQUENCE actions. So check whether we are only running a
RESTART and run with less locking if so.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reported-by: Jason Petersen <jason@citusdata.com>
Reported-by: Andres Freund <andres@anarazel.de>
Consistently refer to such an entry as a "statistics object", not just
"statistics" or "extended statistics". Previously we had a mismash of
terms, accompanied by utter confusion as to whether the term was
singular or plural. That's not only grating (at least to the ear of
a native English speaker) but could be outright misleading, eg in error
messages that seemed to be referring to multiple objects where only one
could be meant.
This commit fixes the code and a lot of comments (though I may have
missed a few). I also renamed two new SQL functions,
pg_get_statisticsextdef -> pg_get_statisticsobjdef
pg_statistic_ext_is_visible -> pg_statistics_obj_is_visible
to conform better with this terminology.
I have not touched the SGML docs other than fixing those function
names; the docs certainly need work but it seems like a separable task.
Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
Tab-completing DROP STATISTICS would only work if you started writing
the schema name containing the statistics object, because the visibility
clause was missing. To add it, we need to add SQL-callable support for
testing visibility of a statistics object, like all other object types
already have.
Discussion: https://postgr.es/m/22676.1494557205@sss.pgh.pa.us
This has to be backpatched to all supported releases so release markup
added to HEAD and copied to back branches matches the existing markup.
Reported-by: Peter Eisentraut
Discussion: 2b8a2552-fffa-f7c8-97c5-14db47a87731@2ndquadrant.com
Author: initial patch and sample markup by Peter Eisentraut
Backpatch-through: 9.2
Previously, we had the WITH clause in the middle of the command, where
you'd specify both generic options as well as statistic types. Few
people liked this, so this commit changes it to remove the WITH keyword
from that clause and makes it accept statistic types only. (We
currently don't have any generic options, but if we invent in the
future, we will gain a new WITH clause, probably at the end of the
command).
Also, the column list is now specified without parens, which makes the
whole command look more similar to a SELECT command. This change will
let us expand the command to supporting expressions (not just columns
names) as well as multiple tables and their join conditions.
Tom added lots of code comments and fixed some parts of the CREATE
STATISTICS reference page, too; more changes in this area are
forthcoming. He also fixed a potential problem in the alter_generic
regression test, reducing verbosity on a cascaded drop to avoid
dependency on message ordering, as we do in other tests.
Tom also closed a security bug: we documented that table ownership was
required in order to create a statistics object on it, but didn't
actually implement it.
Implement tab-completion for statistics objects. This can stand some
more improvement.
Authors: Alvaro Herrera, with lots of cleanup by Tom Lane
Discussion: https://postgr.es/m/20170420212426.ltvgyhnefvhixm6i@alvherre.pgsql
For CREATE/ALTER PUBLICATION/SUBSCRIPTION, use similar option style as
other statements that use a WITH clause for options.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Per discussion, "location" is a rather vague term that could refer to
multiple concepts. "LSN" is an unambiguous term for WAL locations and
should be preferred. Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position". Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.
David Rowley, minor additional docs hacking by me
Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
