Noah Misch [Mon, 26 Feb 2018 15:39:44 +0000 (07:39 -0800)]
Document security implications of search_path and the public schema.
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.
Noah Misch [Mon, 26 Feb 2018 15:39:44 +0000 (07:39 -0800)]
Empty search_path in Autovacuum and non-psql/pgbench clients.
This makes the client programs behave as documented regardless of the
connect-time search_path and regardless of user-created objects. Today,
a malicious user with CREATE permission on a search_path schema can take
control of certain of these clients' queries and invoke arbitrary SQL
functions under the client identity, often a superuser. This is
exploitable in the default configuration, where all users have CREATE
privilege on schema "public".
This changes behavior of user-defined code stored in the database, like
pg_index.indexprs and pg_extension_config_dump(). If they reach code
bearing unqualified names, "does not exist" or "no schema has been
selected to create in" errors might appear. Users may fix such errors
by schema-qualifying affected names. After upgrading, consider watching
server logs for these errors.
The --table arguments of src/bin/scripts clients have been lax; for
example, "vacuumdb -Zt pg_am\;CHECKPOINT" performed a checkpoint. That
now fails, but for now, "vacuumdb -Zt 'pg_am(amname);CHECKPOINT'" still
performs a checkpoint.
Back-patch to 9.3 (all supported versions).
Reviewed by Tom Lane, though this fix strategy was not his first choice.
Reported by Arseniy Sharoglazov.
Tom Lane [Mon, 26 Feb 2018 15:18:22 +0000 (10:18 -0500)]
Avoid using unsafe search_path settings during dump and restore.
Historically, pg_dump has "set search_path = foo, pg_catalog" when
dumping an object in schema "foo", and has also caused that setting
to be used while restoring the object. This is problematic because
functions and operators in schema "foo" could capture references meant
to refer to pg_catalog entries, both in the queries issued by pg_dump
and those issued during the subsequent restore run. That could
result in dump/restore misbehavior, or in privilege escalation if a
nefarious user installs trojan-horse functions or operators.
This patch changes pg_dump so that it does not change the search_path
dynamically. The emitted restore script sets the search_path to what
was used at dump time, and then leaves it alone thereafter. Created
objects are placed in the correct schema, regardless of the active
search_path, by dint of schema-qualifying their names in the CREATE
commands, as well as in subsequent ALTER and ALTER-like commands.
Since this change requires a change in the behavior of pg_restore
when processing an archive file made according to this new convention,
bump the archive file version number; old versions of pg_restore will
therefore refuse to process files made with new versions of pg_dump.
Tom Lane [Fri, 23 Feb 2018 19:38:19 +0000 (14:38 -0500)]
Allow auto_explain.log_min_duration to go up to INT_MAX.
The previous limit of INT_MAX / 1000 seems to have been cargo-culted in
from somewhere else. Or possibly the value was converted to microseconds
at some point; but in all supported releases, it's just compared to other
values, so there's no need for the restriction. This change raises the
effective limit from ~35 minutes to ~24 days, which conceivably is useful
to somebody, and anyway it's more consistent with the range of the core
log_min_duration_statement GUC.
Per complaint from Kevin Bloch. Back-patch to all supported releases.
Tom Lane [Fri, 23 Feb 2018 18:47:33 +0000 (13:47 -0500)]
Fix planner failures with overlapping mergejoin clauses in an outer join.
Given overlapping or partially redundant join clauses, for example
t1 JOIN t2 ON t1.a = t2.x AND t1.b = t2.x
the planner's EquivalenceClass machinery will ordinarily refactor the
clauses as "t1.a = t1.b AND t1.a = t2.x", so that join processing doesn't
see multiple references to the same EquivalenceClass in a list of join
equality clauses. However, if the join is outer, it's incorrect to derive
a restriction clause on the outer side from the join conditions, so the
clause refactoring does not happen and we end up with overlapping join
conditions. The code that attempted to deal with such cases had several
subtle bugs, which could result in "left and right pathkeys do not match in
mergejoin" or "outer pathkeys do not match mergeclauses" planner errors,
if the selected join plan type was a mergejoin. (It does not appear that
any actually incorrect plan could have been emitted.)
The core of the problem really was failure to recognize that the outer and
inner relations' pathkeys have different relationships to the mergeclause
list. A join's mergeclause list is constructed by reference to the outer
pathkeys, so it will always be ordered the same as the outer pathkeys, but
this cannot be presumed true for the inner pathkeys. If the inner sides of
the mergeclauses contain multiple references to the same EquivalenceClass
({t2.x} in the above example) then a simplistic rendering of the required
inner sort order is like "ORDER BY t2.x, t2.x", but the pathkey machinery
recognizes that the second sort column is redundant and throws it away.
The mergejoin planning code failed to account for that behavior properly.
One error was to try to generate cut-down versions of the mergeclause list
from cut-down versions of the inner pathkeys in the same way as the initial
construction of the mergeclause list from the outer pathkeys was done; this
could lead to choosing a mergeclause list that fails to match the outer
pathkeys. The other problem was that the pathkey cross-checking code in
create_mergejoin_plan treated the inner and outer pathkey lists
identically, whereas actually the expectations for them must be different.
That led to false "pathkeys do not match" failures in some cases, and in
principle could have led to failure to detect bogus plans in other cases,
though there is no indication that such bogus plans could be generated.
Reported by Alexander Kuzmenkov, who also reviewed this patch. This has
been broken for years (back to around 8.3 according to my testing), so
back-patch to all supported branches.
Tom Lane [Wed, 21 Feb 2018 23:40:24 +0000 (18:40 -0500)]
Repair pg_upgrade's failure to preserve relfrozenxid for matviews.
This oversight led to data corruption in matviews, manifesting as
"could not access status of transaction" before our most recent releases,
and "found xmin from before relfrozenxid" errors since then.
The proximate cause of the problem seems to have been confusion between
the task of preserving dropped-column status and the task of preserving
frozenxid status. Those are required for distinct sets of relkinds,
and the reasoning was entirely undocumented in the source code. In hopes
of forestalling future errors of the same kind, try to improve the
commentary in this area.
In passing, also improve the remarkably unhelpful comments around
pg_upgrade's set_frozenxids(). That's not actually buggy AFAICS,
but good luck figuring out what it does from the old comments.
Per report from Claudio Freire. It appears that bug #14852 from Alexey
Ermakov is an earlier report of the same issue, and there may be other
cases that we failed to identify at the time.
Patch by me based on analysis by Andres Freund. The bug dates back
to the introduction of matviews, so back-patch to all supported branches.
Tom Lane [Mon, 19 Feb 2018 21:00:18 +0000 (16:00 -0500)]
Fix misbehavior of CTE-used-in-a-subplan during EPQ rechecks.
An updating query that reads a CTE within an InitPlan or SubPlan could get
incorrect results if it updates rows that are concurrently being modified.
This is caused by CteScanNext supposing that nothing inside its recursive
ExecProcNode call could change which read pointer is selected in the CTE's
shared tuplestore. While that's normally true because of scoping
considerations, it can break down if an EPQ plan tree gets built during the
call, because EvalPlanQualStart builds execution trees for all subplans
whether they're going to be used during the recheck or not. And it seems
like a pretty shaky assumption anyway, so let's just reselect our own read
pointer here.
Per bug #14870 from Andrei Gorita. This has been broken since CTEs were
implemented, so back-patch to all supported branches.
Tom Lane [Thu, 15 Feb 2018 18:56:38 +0000 (13:56 -0500)]
Doc: fix minor bug in CREATE TABLE example.
One example in create_table.sgml claimed to be showing table constraint
syntax, but it was really column constraint syntax due to the omission
of a comma. This is both wrong and confusing, so fix it in all
supported branches.
Tom Lane [Wed, 14 Feb 2018 19:47:18 +0000 (14:47 -0500)]
Fix broken logic for reporting PL/Python function names in errcontext.
plpython_error_callback() reported the name of the function associated
with the topmost PL/Python execution context. This was not merely
wrong if there were nested PL/Python contexts, but it risked a core
dump if the topmost one is an inline code block rather than a named
function. That will have proname = NULL, and so we were passing a NULL
pointer to snprintf("%s"). It seems that none of the PL/Python-testing
machines in the buildfarm will dump core for that, but some platforms do,
as reported by Marina Polyakova.
Investigation finds that there actually is an existing regression test
that used to prove that the behavior was wrong, though apparently no one
had noticed that it was printing the wrong function name. It stopped
showing the problem in 9.6 when we adjusted psql to not print CONTEXT
by default for NOTICE messages. The problem is masked (if your platform
avoids the core dump) in error cases, because PL/Python will throw away
the originally generated error info in favor of a new traceback produced
at the outer level.
Repair by using ErrorContextCallback.arg to pass the correct context to
the error callback. Add a regression test illustrating correct behavior.
Back-patch to all supported branches, since they're all broken this way.
Magnus Hagander [Wed, 7 Feb 2018 10:03:55 +0000 (11:03 +0100)]
Change default git repo URL to https
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
Tom Lane [Mon, 5 Feb 2018 15:58:27 +0000 (10:58 -0500)]
Ensure that all temp files made during pg_upgrade are non-world-readable.
pg_upgrade has always attempted to ensure that the transient dump files
it creates are inaccessible except to the owner. However, refactoring
in commit 76a7650c4 broke that for the file containing "pg_dumpall -g"
output; since then, that file was protected according to the process's
default umask. Since that file may contain role passwords (hopefully
encrypted, but passwords nonetheless), this is a particularly unfortunate
oversight. Prudent users of pg_upgrade on multiuser systems would
probably run it under a umask tight enough that the issue is moot, but
perhaps some users are depending only on pg_upgrade's umask changes to
protect their data.
To fix this in a future-proof way, let's just tighten the umask at
process start. There are no files pg_upgrade needs to write at a
weaker security level; and if there were, transiently relaxing the
umask around where they're created would be a safer approach.
Report and patch by Tom Lane; the idea for the fix is due to Noah Misch.
Back-patch to all supported branches.
Bruce Momjian [Wed, 31 Jan 2018 21:43:32 +0000 (16:43 -0500)]
doc: Improve pg_upgrade rsync examples to use clusterdir
Commit 9521ce4a7a1125385fb4de9689f345db594c516a from Sep 13, 2017 and
backpatched through 9.5 used rsync examples with datadir. The reporter
has pointed out, and testing has verified, that clusterdir must be used,
so update the docs accordingly.
Reported-by: Don Seiler
Discussion: https://postgr.es/m/CAHJZqBD0u9dCERpYzK6BkRv=663AmH==DFJpVC=M4Xg_rq2=CQ@mail.gmail.com
Robert Haas [Tue, 30 Jan 2018 19:27:38 +0000 (14:27 -0500)]
Fix test case for 'outer pathkeys do not match mergeclauses' fix.
Commit 4bbf6edfbd5d03743ff82dda2f00c738fb3208f5 added a test case,
but it turns out that the test case doesn't reliably test for the
bug, and in the context of the regression test suite did not because
ANALYZE had not been run.
Report and patch by Etsuro Fujita. I added a comment along lines
previously suggested by Tom Lane.
Tom Lane [Sun, 28 Jan 2018 18:39:07 +0000 (13:39 -0500)]
Add stack-overflow guards in set-operation planning.
create_plan_recurse lacked any stack depth check. This is not per
our normal coding rules, but I'd supposed it was safe because earlier
planner processing is more complex and presumably should eat more
stack. But bug #15033 from Andrew Grossman shows this isn't true,
at least not for queries having the form of a many-thousand-way
INTERSECT stack.
Further testing showed that recurse_set_operations is also capable
of being crashed in this way, since it likewise will recurse to the
bottom of a parsetree before calling any support functions that
might themselves contain any stack checks. However, its stack
consumption is only perhaps a third of create_plan_recurse's.
It's possible that this particular problem with create_plan_recurse can
only manifest in 9.6 and later, since before that we didn't build a Path
tree for set operations. But having seen this example, I now have no
faith in the proposition that create_plan_recurse doesn't need a stack
check, so back-patch to all supported branches.
Tom Lane [Sat, 27 Jan 2018 21:42:28 +0000 (16:42 -0500)]
Update time zone data files to tzdata release 2018c.
DST law changes in Brazil, Sao Tome and Principe. Historical corrections
for Bolivia, Japan, and South Sudan. The "US/Pacific-New" zone has been
removed (it was only a link to America/Los_Angeles anyway).
Tom Lane [Tue, 23 Jan 2018 21:50:35 +0000 (16:50 -0500)]
Teach reparameterize_path() to handle AppendPaths.
If we're inside a lateral subquery, there may be no unparameterized paths
for a particular child relation of an appendrel, in which case we *must*
be able to create similarly-parameterized paths for each other child
relation, else the planner will fail with "could not devise a query plan
for the given query". This means that there are situations where we'd
better be able to reparameterize at least one path for each child.
This calls into question the assumption in reparameterize_path() that
it can just punt if it feels like it. However, the only case that is
known broken right now is where the child is itself an appendrel so that
all its paths are AppendPaths. (I think possibly I disregarded that in
the original coding on the theory that nested appendrels would get folded
together --- but that only happens *after* reparameterize_path(), so it's
not excused from handling a child AppendPath.) Given that this code's been
like this since 9.3 when LATERAL was introduced, it seems likely we'd have
heard of other cases by now if there were a larger problem.
Per report from Elvis Pranskevichus. Back-patch to 9.3.
Robert Haas [Tue, 23 Jan 2018 16:13:50 +0000 (11:13 -0500)]
Report an ERROR if a parallel worker fails to start properly.
Commit 28724fd90d2f85a0573a8107b48abad062a86d83 fixed things so that
if a background worker fails to start due to fork() failure or because
it is terminated before startup succeeds, BGWH_STOPPED will be
reported. However, that only helps if the code that uses the
background worker machinery notices the change in status, and the code
in parallel.c did not.
To fix that, do two things. First, make sure that when a worker
exits, it triggers the leader to read from error queues. That way, if
a worker which has attached to an error queue exits uncleanly, the
leader is sure to throw some error, either the contents of the
ErrorResponse sent by the worker, or "lost connection to parallel
worker" if it exited without sending one. To cover the case where
the worker never starts up in the first place or exits before
attaching to the error queue, the ParallelContext now keeps track
of which workers have sent at least one message via the error
queue. A worker which sends no messages by the time the parallel
operation finishes will be checked to see whether it exited before
attaching to the error queue; if so, a new error message, "parallel
worker failed to initialize", will be reported. If not, we'll
continue to wait until it either starts up and exits cleanly, starts
up and exits uncleanly, or fails to start, and then take the
appropriate action.
Tom Lane [Mon, 22 Jan 2018 17:06:19 +0000 (12:06 -0500)]
Make pg_dump's ACL, sec label, and comment entries reliably identifiable.
_tocEntryRequired() expects that it can identify ACL, SECURITY LABEL,
and COMMENT TOC entries that are for large objects by seeing whether
the tag for them starts with "LARGE OBJECT ". While that works fine
for actual large objects, which are indeed tagged that way, it's
subject to false positives unless every such entry's tag starts with an
appropriate type ID. And in fact it does not work for ACLs, because
up to now we customarily tagged those entries with just the bare name
of the object. This means that an ACL for an object named
"LARGE OBJECT something" would be misclassified as data not schema,
with undesirable results in a schema-only or data-only dump ---
although pg_upgrade seems unaffected, due to the special case for
binary-upgrade mode further down in _tocEntryRequired().
We can fix this by changing all the dumpACL calls to use the label
strings already in use for comments and security labels, which do
follow the convention of starting with an object type indicator.
Well, mostly they follow it. dumpDatabase() got it wrong, using
just the bare database name for those purposes, so that a database
named "LARGE OBJECT something" would similarly be subject to having
its comment or security label dropped or included when not wanted.
Bring that into line too. (Note that up to now, database ACLs have
not been processed by pg_dump, so that this issue doesn't affect them.)
_tocEntryRequired() itself is not free of fault: it was overly liberal
about matching object tags to "LARGE OBJECT " in binary-upgrade mode.
This looks like it is probably harmless because there would be no data
component to strip anyway in that mode, but at best it's trouble
waiting to happen, so tighten that up too.
The possible misclassification of SECURITY LABEL entries for databases is
in principle a security problem, but the opportunities for actual exploits
seem too narrow to be interesting. The other cases seem like just bugs,
since an object owner can change its ACL or comment for himself, he needn't
try to trick someone else into doing it by choosing a strange name.
This has been broken since per-large-object TOC entries were introduced
in 9.0, so back-patch to all supported branches.
Bruce Momjian [Sun, 21 Jan 2018 02:47:02 +0000 (21:47 -0500)]
doc: update intermediate certificate instructions
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.
Alvaro Herrera [Fri, 19 Jan 2018 13:15:08 +0000 (10:15 -0300)]
Fix StoreCatalogInheritance1 to use 32bit inhseqno
For no apparent reason, this function was using a 16bit-wide inhseqno
value, rather than the correct 32 bit width which is what is stored in
the pg_inherits catalog. This becomes evident if you try to create a
table with more than 65535 parents, because this error appears:
Needless to say, having so many parents is an uncommon situations, which
explains why this error has never been reported despite being having
been introduced with the Postgres95 1.01 sources in commit d31084e9d111:
https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/commands/creatinh.c;hb=d31084e9d111#l349
Backpatch all the way back.
David Rowley noticed this while reviewing a patch of mine.
Discussion: https://postgr.es/m/CAKJS1f8Dn7swSEhOWwzZzssW7747YB=2Hi+T7uGud40dur69-g@mail.gmail.com
Tom Lane [Thu, 18 Jan 2018 16:09:44 +0000 (11:09 -0500)]
Extend configure's __int128 test to check for a known gcc bug.
On Sparc64, use of __attribute__(aligned(8)) with __int128 causes faulty
code generation in gcc versions at least through 5.5.0. We can work around
that by disabling use of __int128, so teach configure to test for the bug.
This solution doesn't fix things for the case of cross-compiling with a
buggy compiler; to support that nicely, we'd need to add a manual disable
switch. Unless more such cases turn up, it doesn't seem worth the work.
Affected users could always edit pg_config.h manually.
In passing, fix some typos in the existing configure test for __int128.
They're harmless because we only compile that code not run it, but
they're still confusing for anyone looking at it closely.
This is needed in support of commit 751804998, so back-patch to 9.5
as that was.
Robert Haas [Wed, 17 Jan 2018 21:18:39 +0000 (16:18 -0500)]
postgres_fdw: Avoid 'outer pathkeys do not match mergeclauses' error.
When pushing down a join to a foreign server, postgres_fdw constructs
an alternative plan to be used for any EvalPlanQual rechecks that
prove to be necessary. This plan is stored as the outer subplan of
the Foreign Scan implementing the pushed-down join. Previously, this
alternative plan could have a different nominal sort ordering than its
parent, which seemed OK since there will only be one tuple per base
table anyway in the case of an EvalPlanQual recheck. Actually,
though, it caused a problem if that path was used as a building block
for the EvalPlanQual recheck plan of a higher-level foreign join,
because we could end up with a merge join one of whose inputs was not
labelled with the correct sort order. Repair by injecting an extra
Sort node into the EvalPlanQual recheck plan whenever it would
otherwise fail to be sorted at least as well as its parent Foreign
Scan.
Report by Jeff Janes. Patch by me, reviewed by Tom Lane, who also
provided the test case and comment text.
Tom Lane [Fri, 12 Jan 2018 20:46:37 +0000 (15:46 -0500)]
Avoid unnecessary failure in SELECT concurrent with ALTER NO INHERIT.
If a query against an inheritance tree runs concurrently with an ALTER
TABLE that's disinheriting one of the tree members, it's possible to get
a "could not find inherited attribute" error because after obtaining lock
on the removed member, make_inh_translation_list sees that its columns
have attinhcount=0 and decides they aren't the columns it's looking for.
An ideal fix, perhaps, would avoid including such a just-removed member
table in the query at all; but there seems no way to accomplish that
without adding expensive catalog rechecks or creating a likelihood of
deadlocks. Instead, let's just drop the check on attinhcount. In this
way, a query that's included a just-disinherited child will still
succeed, which is not a completely unreasonable behavior.
This problem has existed for a long time, so back-patch to all supported
branches. Also add an isolation test verifying related behaviors.
Patch by me; the new isolation test is based on Kyotaro Horiguchi's work.
Tom Lane [Fri, 12 Jan 2018 17:24:50 +0000 (12:24 -0500)]
Fix incorrect handling of subquery pullup in the presence of grouping sets.
If we flatten a subquery whose target list contains constants or
expressions, when those output columns are used in GROUPING SET columns,
the planner was capable of doing the wrong thing by merging a pulled-up
expression into the surrounding expression during const-simplification.
Then the late processing that attempts to match subexpressions to grouping
sets would fail to match those subexpressions to grouping sets, with the
effect that they'd not go to null when expected.
To fix, wrap such subquery outputs in PlaceHolderVars, ensuring that
they preserve their separate identity throughout the planner's expression
processing. This is a bit of a band-aid, because the wrapper defeats
const-simplification even in places where it would be safe to allow.
But a nicer fix would likely be too invasive to back-patch, and the
consequences of the missed optimizations probably aren't large in most
cases.
Back-patch to 9.5 where grouping sets were introduced.
Heikki Linnakangas, with small mods and better test cases by me;
additional review by Andrew Gierth
Teodor Sigaev [Thu, 11 Jan 2018 11:43:13 +0000 (14:43 +0300)]
Fix behavior of ~> (cube, int) operator
~> (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
Tom Lane [Wed, 10 Jan 2018 22:13:29 +0000 (17:13 -0500)]
Fix sample INSTR() functions in the plpgsql documentation.
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.
Tom Lane [Wed, 10 Jan 2018 20:50:54 +0000 (15:50 -0500)]
Remove dubious micro-optimization in ckpt_buforder_comparator().
It seems incorrect to assume that the list of CkptSortItems can never
contain duplicate page numbers: concurrent activity could result in some
page getting dropped from a low-numbered buffer and later loaded into a
high-numbered buffer while BufferSync is scanning the buffer pool.
If that happened, the comparator would give self-inconsistent results,
potentially confusing qsort(). Saving one comparison step is not worth
possibly getting the sort wrong.
So far as I can tell, nothing would actually go wrong given our current
implementation of qsort(). It might get a bit slower than expected
if there were a large number of duplicates of one value, but that's
surely a probability-epsilon case. Still, the comment is wrong,
and if we ever switched to another sort implementation it might be
less forgiving.
In passing, avoid casting away const-ness of the argument pointers;
I've not seen any compiler complaints from that, but it seems likely
that some compilers would not like it.
Back-patch to 9.6 where this code came in, just in case I've underestimated
the possible consequences.
Alvaro Herrera [Tue, 9 Jan 2018 18:54:39 +0000 (15:54 -0300)]
Change some bogus PageGetLSN calls to BufferGetLSNAtomic
As src/backend/access/transam/README says, PageGetLSN may only be called
by processes holding either exclusive lock on buffer, or a shared lock
on buffer plus buffer header lock. Therefore any place that only holds
a shared buffer lock must use BufferGetLSNAtomic instead of PageGetLSN,
which internally obtains buffer header lock prior to reading the LSN.
A few callsites failed to comply with this rule. This was detected by
running all tests under a new (not committed) assertion that verifies
PageGetLSN locking contract. All but one of the callsites that failed
the assertion are fixed by this patch. Remaining callsites were
inspected manually and determined not to need any change.
The exception (unfixed callsite) is in TestForOldSnapshot, which only
has a Page argument, making it impossible to access the corresponding
Buffer from it. Fixing that seems a much larger patch that will have to
be done separately; and that's just as well, since it was only
introduced in 9.6 and other bugs are much older.
Some of these bugs are ancient; backpatch all the way back to 9.3.
Alvaro Herrera [Fri, 5 Jan 2018 15:17:10 +0000 (12:17 -0300)]
Fix failure to delete spill files of aborted transactions
Logical decoding's reorderbuffer.c may spill transaction files to disk
when transactions are large. These are supposed to be removed when they
become "too old" by xid; but file removal requires the boundary LSNs of
the transaction to be known. The final_lsn is only set when we see the
commit or abort record for the transaction, but nothing sets the value
for transactions that crash, so the removal code misbehaves -- in
assertion-enabled builds, it crashes by a failed assertion.
To fix, modify the final_lsn of transactions that don't have a value
set, to the LSN of the very latest change in the transaction. This
causes the spilled files to be removed appropriately.
Tom Lane [Thu, 4 Jan 2018 19:59:00 +0000 (14:59 -0500)]
Fix incorrect computations of length of null bitmap in pageinspect.
Instead of using our standard macro for this calculation, this code
did it itself ... and got it wrong, leading to incorrect display of
the null bitmap in some cases. Noted and fixed by Maksim Milyutin.
In passing, remove a uselessly duplicative error check.
Errors were introduced in commit d6061f83a; back-patch to 9.6
where that came in.
Robert Haas [Tue, 19 Dec 2017 17:21:56 +0000 (12:21 -0500)]
Back-port fix for accumulation of parallel worker instrumentation.
When a Gather or Gather Merge node is started and stopped multiple
times, accumulate instrumentation data only once, at the end, instead
of after each execution, to avoid recording inflated totals.
Alvaro Herrera [Wed, 3 Jan 2018 14:16:34 +0000 (11:16 -0300)]
Revert "Fix isolation test to be less timing-dependent"
This reverts commit 2268e6afd596. It turned out that inconsistency in
the report is still possible, so go back to the simpler formulation of
the test and instead add an alternate expected output.
Andres Freund [Wed, 3 Jan 2018 20:00:11 +0000 (12:00 -0800)]
Rename pg_rewind's copy_file_range() to avoid conflict with new linux syscall.
Upcoming versions of glibc will contain copy_file_range(2), a wrapper
around a new linux syscall for in-kernel copying of data ranges. This
conflicts with pg_rewinds function of the same name.
Therefore rename pg_rewinds version. As our version isn't a generic
copying facility we decided to choose a rewind specific function name.
Per buildfarm animal caiman and subsequent discussion with Tom Lane.
Author: Andres Freund
Discussion:
https://postgr.es/m/20180103033425.w7jkljth3e26sduc@alap3.anarazel.de
https://postgr.es/m/31122.1514951044@sss.pgh.pa.us
Backpatch: 9.5-, where pg_rewind was introduced
Andrew Dunstan [Wed, 3 Jan 2018 20:26:39 +0000 (15:26 -0500)]
Fix use of config-specific libraries for Windows OpenSSL
Commit 614350a3 allowed for an different builds of OpenSSL libraries on
Windows, but ignored the fact that the alternative builds don't have
config-specific libraries. This patch fixes the Solution file to ask for
the correct libraries.
per offline discussions with Leonardo Cecchi and Marco Nenciarini,
Alvaro Herrera [Wed, 3 Jan 2018 20:26:20 +0000 (17:26 -0300)]
Make XactLockTableWait work for transactions that are not yet self-locked
XactLockTableWait assumed that its xid argument has already added itself
to the lock table. That assumption led to another assumption that if
locking the xid has succeeded but the xid is reported as still in
progress, then the input xid must have been a subtransaction.
These assumptions hold true for the original uses of this code in
locking related to on-disk tuples, but they break down in logical
replication slot snapshot building -- in particular, when a standby
snapshot logged contains an xid that's already in ProcArray but not yet
in the lock table. This leads to assertion failures that can be
reproduced all the way back to 9.4, when logical decoding was
introduced.
To fix, change SubTransGetParent to SubTransGetTopmostTransaction which
has a slightly different API: it returns the argument Xid if there is no
parent, and it goes all the way to the top instead of moving up the
levels one by one. Also, to avoid busy-waiting, add a 1ms sleep to give
the other process time to register itself in the lock table.
For consistency, change ConditionalXactLockTableWait the same way.
Author: Petr Jelínek
Discussion: https://postgr.es/m/1B3E32D8-FCF4-40B4-AEF9-5C0E3AC57969@postgrespro.ru Reported-by: Konstantin Knizhnik Diagnosed-by: Stas Kelvich, Petr Jelínek Reviewed-by: Andres Freund, Robert Haas
Alvaro Herrera [Tue, 2 Jan 2018 22:16:16 +0000 (19:16 -0300)]
Fix deadlock hazard in CREATE INDEX CONCURRENTLY
Multiple sessions doing CREATE INDEX CONCURRENTLY simultaneously are
supposed to be able to work in parallel, as evidenced by fixes in commit c3d09b3bd23f specifically to support this case. In reality, one of the
sessions would be aborted by a misterious "deadlock detected" error.
Jeff Janes diagnosed that this is because of leftover snapshots used for
system catalog scans -- this was broken by 8aa3e47510b9 keeping track of
(registering) the catalog snapshot. To fix the deadlocks, it's enough
to de-register that snapshot prior to waiting.
Backpatch to 9.4, which introduced MVCC catalog scans.
Include an isolationtester spec that 8 out of 10 times reproduces the
deadlock with the unpatched code for me (Álvaro).
Author: Jeff Janes Diagnosed-by: Jeff Janes Reported-by: Jeremy Finzel
Discussion: https://postgr.es/m/CAMa1XUhHjCv8Qkx0WOr1Mpm_R4qxN26EibwCrj0Oor2YBUFUTg%40mail.gmail.com
Noah Misch [Mon, 1 Jan 2018 05:58:29 +0000 (21:58 -0800)]
In tests, await an LSN no later than the recovery target.
Otherwise, the test fails with "Timed out while waiting for standby to
catch up". This happened rarely, perhaps only when autovacuum wrote WAL
between our choosing the recovery target and choosing the LSN to await.
Commit b26f7fa6ae2b4e5d64525b3d5bc66a0ddccd9e24 fixed one case of this.
Fix two more. Back-patch to 9.6, which introduced the affected test.
Tom Lane [Fri, 22 Dec 2017 17:08:28 +0000 (12:08 -0500)]
Disallow UNION/INTERSECT/EXCEPT over no columns.
Since 9.4, we've allowed the syntax "select union select" and variants
of that. However, the planner wasn't expecting a no-column set operation
and ended up treating the set operation as if it were UNION ALL.
Pre-v10, there seem to be some executor issues that would need to be
fixed to support such cases, and it doesn't really seem worth expending
much effort on. Just disallow it, instead.
Fujii Masao [Mon, 18 Dec 2017 18:46:14 +0000 (03:46 +0900)]
Fix bug in cancellation of non-exclusive backup to avoid assertion failure.
Previously an assertion failure occurred when pg_stop_backup() for
non-exclusive backup was aborted while it's waiting for WAL files to
be archived. This assertion failure happened in do_pg_abort_backup()
which was called when a non-exclusive backup was canceled.
do_pg_abort_backup() assumes that there is at least one non-exclusive
backup running when it's called. But pg_stop_backup() can be canceled
even after it marks the end of non-exclusive backup (e.g.,
during waiting for WAL archiving). This broke the assumption that
do_pg_abort_backup() relies on, and which caused an assertion failure.
This commit changes do_pg_abort_backup() so that it does nothing
when non-exclusive backup has been already marked as completed.
That is, the asssumption is also changed, and do_pg_abort_backup()
now can handle even the case where it's called when there is
no running backup.
Backpatch to 9.6 where SQL-callable non-exclusive backup was added.
Author: Masahiko Sawada and Michael Paquier Reviewed-By: Robert Haas and Fujii Masao
Discussion: https://www.postgresql.org/message-id/CAD21AoD2L1Fu2c==gnVASMyFAAaq3y-AQ2uEVj-zTCGFFjvmDg@mail.gmail.com
Andres Freund [Tue, 14 Nov 2017 02:45:47 +0000 (18:45 -0800)]
Perform a lot more sanity checks when freezing tuples.
The previous commit has shown that the sanity checks around freezing
aren't strong enough. Strengthening them seems especially important
because the existance of the bug has caused corruption that we don't
want to make even worse during future vacuum cycles.
The errors are emitted with ereport rather than elog, despite being
"should never happen" messages, so a proper error code is emitted. To
avoid superflous translations, mark messages as internal.
Author: Andres Freund and Alvaro Herrera Reviewed-By: Alvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
Backpatch: 9.3-
Andres Freund [Fri, 3 Nov 2017 14:52:29 +0000 (07:52 -0700)]
Fix pruning of locked and updated tuples.
Previously it was possible that a tuple was not pruned during vacuum,
even though its update xmax (i.e. the updating xid in a multixact with
both key share lockers and an updater) was below the cutoff horizon.
As the freezing code assumed, rightly so, that that's not supposed to
happen, xmax would be preserved (as a member of a new multixact or
xmax directly). That causes two problems: For one the tuple is below
the xmin horizon, which can cause problems if the clog is truncated or
once there's an xid wraparound. The bigger problem is that that will
break HOT chains, which in turn can lead two to breakages: First,
failing index lookups, which in turn can e.g lead to constraints being
violated. Second, future hot prunes / vacuums can end up making
invisible tuples visible again. There's other harmful scenarios.
Fix the problem by recognizing that tuples can be DEAD instead of
RECENTLY_DEAD, even if the multixactid has alive members, if the
update_xid is below the xmin horizon. That's safe because newer
versions of the tuple will contain the locking xids.
A followup commit will harden the code somewhat against future similar
bugs and already corrupted data.
Author: Andres Freund, with changes by Alvaro Herrera Reported-By: Daniel Wood Analyzed-By: Andres Freund, Alvaro Herrera, Robert Haas, Peter
Geoghegan, Daniel Wood, Yi Wen Wong, Michael Paquier Reviewed-By: Alvaro Herrera, Robert Haas, Michael Paquier
Discussion:
https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.com
https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
Backpatch: 9.3-
Andrew Dunstan [Thu, 14 Dec 2017 16:31:13 +0000 (11:31 -0500)]
Fix walsender timeouts when decoding a large transaction
The logical slots have a fast code path for sending data so as not to
impose too high a per message overhead. The fast path skips checks for
interrupts and timeouts. However, the existing coding failed to consider
the fact that a transaction with a large number of changes may take a
very long time to be processed and sent to the client. This causes the
walsender to ignore interrupts for potentially a long time and more
importantly it will result in the walsender being killed due to
timeout at the end of such a transaction.
This commit changes the fast path to also check for interrupts and only
allows calling the fast path when the last keepalive check happened less
than half the walsender timeout ago. Otherwise the slower code path will
be taken.
Backpatched to 9.4
Petr Jelinek, reviewed by Kyotaro HORIGUCHI, Yura Sokolov, Craig
Ringer and Robert Haas.
Tom Lane [Mon, 11 Dec 2017 21:33:20 +0000 (16:33 -0500)]
Fix corner-case coredump in _SPI_error_callback().
I noticed that _SPI_execute_plan initially sets spierrcontext.arg = NULL,
and only fills it in some time later. If an error were to happen in
between, _SPI_error_callback would try to dereference the null pointer.
This is unlikely --- there's not much between those points except
push-snapshot calls --- but it's clearly not impossible. Tweak the
callback to do nothing if the pointer isn't set yet.
It's been like this for awhile, so back-patch to all supported branches.
Noah Misch [Sat, 9 Dec 2017 08:58:55 +0000 (00:58 -0800)]
MSVC 2012+: Permit linking to 32-bit, MinGW-built libraries.
Notably, this permits linking to the 32-bit Perl binaries advertised on
perl.org, namely Strawberry Perl and ActivePerl. This has a side effect
of permitting linking to binaries built with obsolete MSVC versions.
By default, MSVC 2012 and later require a "safe exception handler table"
in each binary. MinGW-built, 32-bit DLLs lack the relevant exception
handler metadata, so linking to them failed with error LNK2026. Restore
the semantics of MSVC 2010, which omits the table from a given binary if
some linker input lacks metadata. This has no effect on 64-bit builds
or on MSVC 2010 and earlier. Back-patch to 9.3 (all supported
versions).
Noah Misch [Sat, 9 Dec 2017 02:06:05 +0000 (18:06 -0800)]
MSVC: Test whether 32-bit Perl needs -D_USE_32BIT_TIME_T.
Commits 5a5c2feca3fd858e70ea348822595547e6fa6c15 and b5178c5d08ca59e30f9d9428fa6fdb2741794e65 introduced support for modern
MSVC-built, 32-bit Perl, but they broke use of MinGW-built, 32-bit Perl
distributions like Strawberry Perl and modern ActivePerl. Perl has no
robust means to report whether it expects a -D_USE_32BIT_TIME_T ABI, so
test this. Back-patch to 9.3 (all supported versions).
The chief alternative was a heuristic of adding -D_USE_32BIT_TIME_T when
$Config{gccversion} is nonempty. That banks on every gcc-built Perl
using the same ABI. gcc could change its default ABI the way MSVC once
did, and one could build Perl with gcc and the non-default ABI.
The GNU make build system could benefit from a similar test, without
which it does not support MSVC-built Perl. For now, just add a comment.
Most users taking the special step of building Perl with MSVC probably
build PostgreSQL with MSVC.
Robert Haas [Wed, 6 Dec 2017 13:49:30 +0000 (08:49 -0500)]
Report failure to start a background worker.
When a worker is flagged as BGW_NEVER_RESTART and we fail to start it,
or if it is not marked BGW_NEVER_RESTART but is terminated before
startup succeeds, what BgwHandleStatus should be reported? The
previous code really hadn't considered this possibility (as indicated
by the comments which ignore it completely) and would typically return
BGWH_NOT_YET_STARTED, but that's not a good answer, because then
there's no way for code using GetBackgroundWorkerPid() to tell the
difference between a worker that has not started but will start
later and a worker that has not started and will never be started.
So, when this case happens, return BGWH_STOPPED instead. Update the
comments to reflect this.
The preceding fix by itself is insufficient to fix the problem,
because the old code also didn't send a notification to the process
identified in bgw_notify_pid when startup failed. That might've
been technically correct under the theory that the status of the
worker was BGWH_NOT_YET_STARTED, because the status would indeed not
change when the worker failed to start, but now that we're more
usefully reporting BGWH_STOPPED, a notification is needed.
Without these fixes, code which starts background workers and then
uses the recommended APIs to wait for those background workers to
start would hang indefinitely if the postmaster failed to fork a
worker.
Tom Lane [Mon, 4 Dec 2017 22:02:52 +0000 (17:02 -0500)]
Clean up assorted messiness around AllocateDir() usage.
This patch fixes a couple of low-probability bugs that could lead to
reporting an irrelevant errno value (and hence possibly a wrong SQLSTATE)
concerning directory-open or file-open failures. It also fixes places
where we took shortcuts in reporting such errors, either by using elog
instead of ereport or by using ereport but forgetting to specify an
errcode. And it eliminates a lot of just plain redundant error-handling
code.
In service of all this, export fd.c's formerly-static function
ReadDirExtended, so that external callers can make use of the coding
pattern
dir = AllocateDir(path);
while ((de = ReadDirExtended(dir, path, LOG)) != NULL)
if they'd like to treat directory-open failures as mere LOG conditions
rather than errors. Also fix FreeDir to be a no-op if we reach it
with dir == NULL, as such a coding pattern would cause.
Then, remove code at many call sites that was throwing an error or log
message for AllocateDir failure, as ReadDir or ReadDirExtended can handle
that job just fine. Aside from being a net code savings, this gets rid of
a lot of not-quite-up-to-snuff reports, as mentioned above. (In some
places these changes result in replacing a custom error message such as
"could not open tablespace directory" with more generic wording "could not
open directory", but it was agreed that the custom wording buys little as
long as we report the directory name.) In some other call sites where we
can't just remove code, change the error reports to be fully
project-style-compliant.
Also reorder code in restoreTwoPhaseData that was acquiring a lock
between AllocateDir and ReadDir; in the unlikely but surely not
impossible case that LWLockAcquire changes errno, AllocateDir failures
would be misreported. There is no great value in opening the directory
before acquiring TwoPhaseStateLock, so just do it in the other order.
Also fix CheckXLogRemoved to guarantee that it preserves errno,
as quite a number of call sites are implicitly assuming. (Again,
it's unlikely but I think not impossible that errno could change
during a SpinLockAcquire. If so, this function was broken for its
own purposes as well as breaking callers.)
And change a few places that were using not-per-project-style messages,
such as "could not read directory" when "could not open directory" is
more correct.
Back-patch the exporting of ReadDirExtended, in case we have occasion
to back-patch some fix that makes use of it; it's not needed right now
but surely making it global is pretty harmless. Also back-patch the
restoreTwoPhaseData and CheckXLogRemoved fixes. The rest of this is
essentially cosmetic and need not get back-patched.
Michael Paquier, with a bit of additional work by me
Noah Misch [Thu, 30 Nov 2017 08:57:22 +0000 (00:57 -0800)]
Fix non-GNU makefiles for AIX make.
Invoking the Makefile without an explicit target was building every
possible target instead of just the "all" target. Back-patch to 9.3
(all supported versions).
Tom Lane [Mon, 27 Nov 2017 22:53:56 +0000 (17:53 -0500)]
Fix creation of resjunk tlist entries for inherited mixed UPDATE/DELETE.
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
Tom Lane [Sun, 26 Nov 2017 20:17:25 +0000 (15:17 -0500)]
Pad XLogReaderState's main_data buffer more aggressively.
Originally, we palloc'd this buffer just barely big enough to hold the
largest xlog record seen so far. It turns out that that can result in
valgrind complaints, because some compilers will emit code that assumes
it can safely fetch padding bytes at the end of a struct, and those
padding bytes were unallocated so far as aset.c was concerned. We can
fix that by MAXALIGN'ing the palloc request size, ensuring that it is big
enough to include any possible padding that might've been omitted from
the on-disk record.
An additional objection to the original coding is that it could result in
many repeated palloc cycles, in the worst case where we see a series of
gradually larger xlog records. We can ameliorate that cheaply by
imposing a minimum buffer size that's large enough for most xlog records.
BLCKSZ/2 was chosen after a bit of discussion.
In passing, remove an obsolete comment in struct xl_heap_new_cid that the
combocid field is free due to alignment considerations. Perhaps that was
true at some point, but it's not now.
Joe Conway [Sun, 26 Nov 2017 17:50:15 +0000 (09:50 -0800)]
Make has_sequence_privilege support WITH GRANT OPTION
The various has_*_privilege() functions all support an optional
WITH GRANT OPTION added to the supported privilege types to test
whether the privilege is held with grant option. That is, all except
has_sequence_privilege() variations. Fix that.
Tom Lane [Sat, 25 Nov 2017 20:30:11 +0000 (15:30 -0500)]
Replace raw timezone source data with IANA's new compact format.
Traditionally IANA has distributed their timezone data in pure source
form, replete with extensive historical comments. As of release 2017c,
they've added a compact single-file format that omits comments and
abbreviates command keywords. This form is way shorter than the pure
source, even before considering its allegedly better compressibility.
Hence, let's distribute the data in that form rather than pure source.
I'm pushing this now, rather than at the next timezone database update,
so that it's easy to confirm that this data file produces compiled zic
output that's identical to what we were getting before.
Tom Lane [Sat, 25 Nov 2017 19:42:10 +0000 (14:42 -0500)]
Avoid formally-undefined use of memcpy() in hstoreUniquePairs().
hstoreUniquePairs() often called memcpy with equal source and destination
pointers. Although this is almost surely harmless in practice, it's
undefined according to the letter of the C standard. Some versions of
valgrind will complain about it, and some versions of libc as well
(cf. commit ad520ec4a). Tweak the code to avoid doing that.
Noted by Tomas Vondra. Back-patch to all supported versions because
of the hazard of libc assertions.
Tom Lane [Sat, 25 Nov 2017 19:15:48 +0000 (14:15 -0500)]
Repair failure with SubPlans in multi-row VALUES lists.
When nodeValuesscan.c was written, it was impossible to have a SubPlan in
VALUES --- any sub-SELECT there would have to be uncorrelated and thereby
would produce an InitPlan instead. We therefore took a shortcut in the
logic that throws away a ValuesScan's per-row expression evaluation data
structures. This was broken by the introduction of LATERAL however; a
sub-SELECT containing a lateral reference produces a correlated SubPlan.
The cleanest fix for this would be to give up the optimization of
discarding the expression eval state. But that still seems pretty
unappetizing for long VALUES lists. It seems to work to just prevent
the subexpressions from hooking into the ValuesScan node's subPlan
list, so let's do that and see how well it works. (If this breaks,
due to additional connections between the subexpressions and the outer
query structures, we might consider compromises like throwing away data
only for VALUES rows not containing SubPlans.)
Per bug #14924 from Christian Duta. Back-patch to 9.3 where LATERAL
was introduced.
Dean Rasheed [Fri, 24 Nov 2017 12:00:00 +0000 (12:00 +0000)]
Doc: add a summary table to the CREATE POLICY docs.
This table summarizes which RLS policy expressions apply to each
command type, and whether they apply to the old or new tuples (or
both), which saves reading through a lot of text.
Rod Taylor, hacked on by me. Reviewed by Fabien Coelho.
Tom Lane [Fri, 24 Nov 2017 05:29:20 +0000 (00:29 -0500)]
Fix unstable regression test added by commits 59b71c6fe et al.
The query didn't really have a preferred index, leading to platform-
specific choices of which one to use. Adjust it to make sure tenk1_hundred
is always chosen.
Noah Misch [Fri, 24 Nov 2017 04:22:04 +0000 (20:22 -0800)]
Support linking with MinGW-built Perl.
This is necessary for ActivePerl 5.18 onwards and for Strawberry Perl.
It is not sufficient for 32-bit builds with newer Visual Studio; these
fail with error LINK2026. Back-patch to 9.3 (all supported versions).
Andres Freund [Fri, 24 Nov 2017 01:14:43 +0000 (17:14 -0800)]
Fix handling of NULLs returned by aggregate combine functions.
When strict aggregate combine functions, used in multi-stage/parallel
aggregation, returned NULL, we didn't check for that, invoking the
combine function with NULL the next round, despite it being strict.
The equivalent code invoking normal transition functions has a check
for that situation, which did not get copied in a7de3dc5c346. Fix the
bug by adding the equivalent check.
Based on a quick look I could not find any strict combine functions in
core actually returning NULL, and it doesn't seem very likely external
users have done so. So this isn't likely to have caused issues in
practice.
Reported-By: Andres Freund
Author: Andres Freund
Discussion: https://postgr.es/m/20171121033642.7xvmjqrl4jdaaat3@alap3.anarazel.de
Backpatch: 9.6, where parallel aggregation was introduced
Robert Haas [Tue, 21 Nov 2017 18:56:24 +0000 (13:56 -0500)]
Provide for forward compatibility with future minor protocol versions.
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.
Tom Lane [Mon, 20 Nov 2017 22:57:46 +0000 (17:57 -0500)]
Add support for Motorola 88K to s_lock.h.
Apparently there are still people out there who care about this old
architecture. They probably care about dusty versions of Postgres
too, so back-patch to all supported branches.
David Carlier (from a patch being carried by OpenBSD packagers)
Tom Lane [Sat, 18 Nov 2017 21:46:30 +0000 (16:46 -0500)]
Fix compiler warning in rangetypes_spgist.c.
On gcc 7.2.0, comparing pointer to (Datum) 0 produces a warning.
Treat it as a simple pointer to avoid that; this is more consistent
with comparable code elsewhere, anyway.
Tom Lane [Fri, 17 Nov 2017 17:46:52 +0000 (12:46 -0500)]
Provide modern examples of how to auto-start Postgres on macOS.
The scripts in contrib/start-scripts/osx don't work at all on macOS
10.10 (Yosemite) or later, because they depend on SystemStarter which
Apple deprecated long ago and removed in 10.10. Add a new subdirectory
contrib/start-scripts/macos with scripts that use the newer launchd
infrastructure.
Since this problem is independent of which Postgres version you're using,
back-patch to all supported branches.
Robert Haas [Thu, 16 Nov 2017 19:19:27 +0000 (14:19 -0500)]
Fix broken cleanup interlock for GIN pending list.
The pending list must (for correctness) always be cleaned up by vacuum, and
should (for the avoidance of surprising behavior) always be cleaned up
by an explicit call to gin_clean_pending_list, but cleanup is optional
when inserting. The old logic got this backward: cleanup was forced
if (stats == NULL), but that's going to be *false* when vacuuming and
*true* for inserts.
Tom Lane [Tue, 14 Nov 2017 22:49:49 +0000 (17:49 -0500)]
Prevent int128 from requiring more than MAXALIGN alignment.
Our initial work with int128 neglected alignment considerations, an
oversight that came back to bite us in bug #14897 from Vincent Lachenal.
It is unsurprising that int128 might have a 16-byte alignment requirement;
what's slightly more surprising is that even notoriously lax Intel chips
sometimes enforce that.
Raising MAXALIGN seems out of the question: the costs in wasted disk and
memory space would be significant, and there would also be an on-disk
compatibility break. Nor does it seem very practical to try to allow some
data structures to have more-than-MAXALIGN alignment requirement, as we'd
have to push knowledge of that throughout various code that copies data
structures around.
The only way out of the box is to make type int128 conform to the system's
alignment assumptions. Fortunately, gcc supports that via its
__attribute__(aligned()) pragma; and since we don't currently support
int128 on non-gcc-workalike compilers, we shouldn't be losing any platform
support this way.
Although we could have just done pg_attribute_aligned(MAXIMUM_ALIGNOF) and
called it a day, I did a little bit of extra work to make the code more
portable than that: it will also support int128 on compilers without
__attribute__(aligned()), if the native alignment of their 128-bit-int
type is no more than that of int64.
Add a regression test case that exercises the one known instance of the
problem, in parallel aggregation over a bigint column.
Back-patch of commit 751804998. The code known to be affected only exists
in 9.6 and later, but we do have some stuff using int128 in 9.5, so patch
back to 9.5.
Tom Lane [Tue, 14 Nov 2017 22:22:42 +0000 (17:22 -0500)]
Rearrange c.h to create a "compiler characteristics" section.
Generalize section 1 to handle stuff that is principally about the
compiler (not libraries), such as attributes, and collect stuff there
that had been dropped into various other parts of c.h. Also, push
all the gettext macros into section 8, so that section 0 is really
just inclusions rather than inclusions and random other stuff.
The primary goal here is to get pg_attribute_aligned() defined before
section 3, so that we can use it with int128. But this seems like good
cleanup anyway.
This patch just moves macro definitions around, and shouldn't result
in any changes in generated code.
Noah Misch [Sun, 12 Nov 2017 22:31:00 +0000 (14:31 -0800)]
Install Windows crash dump handler before all else.
Apart from calling write_stderr() on failure, the handler depends on no
PostgreSQL facilities. We have experienced crashes before reaching the
former call site. Given such an early crash, this change cannot hurt
and may produce a helpful dump. Absent an early crash, this change has
no effect. Back-patch to 9.3 (all supported versions).
Noah Misch [Sun, 12 Nov 2017 21:03:15 +0000 (13:03 -0800)]
Don't call pgwin32_message_to_UTF16() without CurrentMemoryContext.
PostgreSQL running as a Windows service crashed upon calling
write_stderr() before MemoryContextInit(). This fix completes work
started in 5735efee15540765315aa8c1a230575e756037f7. Messages this
early contain only ASCII bytes; if we removed the CurrentMemoryContext
requirement, the ensuing conversions would have no effect. Back-patch
to 9.3 (all supported versions).
Noah Misch [Sat, 11 Nov 2017 22:39:06 +0000 (14:39 -0800)]
Add post-2010 ecpg tests to checktcp.
This suite had been a proper superset of the regular ecpg test suite,
but the three newest tests didn't reach it. To make this less likely to
recur, delete the extra schedule file and pass the TCP-specific test on
the command line. Back-patch to 9.3 (all supported versions).
Noah Misch [Sat, 11 Nov 2017 22:33:02 +0000 (14:33 -0800)]
Make connect/test1 independent of localhost IPv6.
Since commit 868898739a8da9ab74c105b8349b7b5c711f265a, it has assumed
"localhost" resolves to both ::1 and 127.0.0.1. We gain nothing from
that assumption, and it does not hold in a default installation of Red
Hat Enterprise Linux 5. Back-patch to 9.3 (all supported versions).
Noah Misch [Sat, 11 Nov 2017 19:10:53 +0000 (11:10 -0800)]
Ignore XML declaration in xpath_internal(), for UTF8 databases.
When a value contained an XML declaration naming some other encoding,
this function interpreted UTF8 bytes as the named encoding, yielding
mojibake. xml_parse() already has similar logic. This would be
necessary but not sufficient for non-UTF8 databases, so preserve
behavior there until the xpath facility can support such databases
comprehensively. Back-patch to 9.3 (all supported versions).
Tom Lane [Fri, 10 Nov 2017 17:30:01 +0000 (12:30 -0500)]
Tighten test in contrib/bloom/t/001_wal.pl.
Make bloom WAL test compare psql output text, not just result codes;
this was evidently the intent all along, but it was mis-coded.
In passing, make sure we will notice any failure in setup steps.
Alexander Korotkov, reviewed by Michael Paquier and Masahiko Sawada
projects / postgresql / log