When a feature enumerates relations and runs functions associated with
all found relations, the feature's user shall not need to trust every
user having permission to create objects. BRIN-specific functionality
in autovacuum neglected to account for this, as did pg_amcheck and
CLUSTER. An attacker having permission to create non-temp objects in at
least one schema could execute arbitrary SQL functions under the
identity of the bootstrap superuser. CREATE INDEX (not a
relation-enumerating operation) and REINDEX protected themselves too
late. This change extends to the non-enumerating amcheck interface.
Back-patch to v10 (all supported versions).
Sergey Shinderuk, reviewed (in earlier versions) by Alexander Lakhin.
Reported by Alexander Lakhin.
Security: CVE-2022-1552
An ALTER FUNCTION command that tried to update both the function's
proparallel property and its proconfig list failed to do the former,
because it stored the new proparallel value into a tuple that was
no longer the interesting one. Carelessness in 7aea8e4f2.
(I did not bother with a regression test, because the only likely
future breakage would be for someone to ignore the comment I added
and add some other field update after the heap_modify_tuple step.
A test using existing function properties could not catch that.)
Per report from Bryn Llewellyn. Back-patch to all supported branches.
Discussion: https://postgr.es/m/8AC9A37F-99BD-446F-A2F7-B89AD0022774@yugabyte.com
Crash recovery on standby may encounter missing directories when
replaying create database WAL records. Prior to this patch, the standby
would fail to recover in such a case. However, the directories could be
legitimately missing. Consider a sequence of WAL records as follows:
CREATE DATABASE
DROP DATABASE
DROP TABLESPACE
If, after replaying the last WAL record and removing the tablespace
directory, the standby crashes and has to replay the create database
record again, the crash recovery must be able to move on.
This patch adds a mechanism similar to invalid-page tracking, to keep a
tally of missing directories during crash recovery. If all the missing
directory references are matched with corresponding drop records at the
end of crash recovery, the standby can safely continue following the
primary.
Backpatch to 13, at least for now. The bug is older, but fixing it in
older branches requires more careful study of the interactions with
commit e6d8069522, which appeared in 13.
A new TAP test file is added to verify the condition. However, because
it depends on commit d6d317dbf6, it can only be added to branch
master. I (Álvaro) manually verified that the code behaves as expected
in branch 14. It's a bit nervous-making to leave the code uncovered by
tests in older branches, but leaving the bug unfixed is even worse.
Also, the main reason this fix took so long is precisely that we
couldn't agree on a good strategy to approach testing for the bug, so
perhaps this is the best we can do.
Diagnosed-by: Paul Guo <paulguo@gmail.com>
Author: Paul Guo <paulguo@gmail.com>
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Asim R Praveen <apraveen@pivotal.io>
Discussion: https://postgr.es/m/CAEET0ZGx9AvioViLf7nbR_8tH9-=27DN5xWJ2P9-ROH16e4JUA@mail.gmail.com
DROP INDEX needs to lock the index's table before the index itself,
else it will deadlock against ordinary queries that acquire the
relation locks in that order. This is correctly mechanized for
plain indexes by RangeVarCallbackForDropRelation; but in the case of
a partitioned index, we neglected to lock the child tables in advance
of locking the child indexes. We can fix that by traversing the
inheritance tree and acquiring the needed locks in RemoveRelations,
after we have acquired our locks on the parent partitioned table and
index.
While at it, do some refactoring to eliminate confusion between
the actual and expected relkind in RangeVarCallbackForDropRelation.
We can save a couple of syscache lookups too, by having that function
pass back info that RemoveRelations will need.
Back-patch to v11 where partitioned indexes were added.
Jimmy Yih, Gaurab Dey, Tom Lane
Discussion: https://postgr.es/m/BYAPR05MB645402330042E17D91A70C12BD5F9@BYAPR05MB6454.namprd05.prod.outlook.com
The syscache lookup may return NULL even for valid OID, for example due
to a concurrent DROP STATISTICS, so a HeapTupleIsValid is necessary.
Without it, it may fail with a segfault.
Reported by Alexander Lakhin, patch by me. Backpatch to 13, where ALTER
STATISTICS ... SET STATISTICS was introduced.
Backpatch-through: 13
Discussion: https://postgr.es/m/17372-bf3b6e947e35ae77%40postgresql.org
Commit 859b3003de disabled building of extended stats for inheritance
trees, to prevent updating the same catalog row twice. While that
resolved the issue, it also means there are no extended stats for
declaratively partitioned tables, because there are no data in the
non-leaf relations.
That also means declaratively partitioned tables were not affected by
the issue 859b3003de addressed, which means this is a regression
affecting queries that calculate estimates for the whole inheritance
tree as a whole (which includes e.g. GROUP BY queries).
But because partitioned tables are empty, we can invert the condition
and build statistics only for the case with inheritance, without losing
anything. And we can consider them when calculating estimates.
It may be necessary to run ANALYZE on partitioned tables, to collect
proper statistics. For declarative partitioning there should no prior
statistics, and it might take time before autoanalyze is triggered. For
tables partitioned by inheritance the statistics may include data from
child relations (if built 859b3003de), contradicting the current code.
Report and patch by Justin Pryzby, minor fixes and cleanup by me.
Backpatch all the way back to PostgreSQL 10, where extended statistics
were introduced (same as 859b3003de).
Author: Justin Pryzby
Reported-by: Justin Pryzby
Backpatch-through: 10
Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
We disallow altering a column datatype within a regular table,
if the table's rowtype is used as a column type elsewhere,
because we lack code to go around and rewrite the other tables.
This restriction should apply to partitioned tables as well, but it
was not checked because ATRewriteTables and ATPrepAlterColumnType
were not on the same page about who should do it for which relkinds.
Per bug #17351 from Alexander Lakhin. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/17351-6db1870f3f4f612a@postgresql.org
Commit 4ace45677 failed to fix the problem fully, because the
same issue of attempting to fetch a non-returnable index column
can occur when rechecking the indexqual after using a lossy index
operator. Moreover, it broke EXPLAIN for such indexquals (which
indicates a gap in our test cases :-().
Revert the code changes of 4ace45677 in favor of adding a new field
to struct IndexOnlyScan, containing a version of the indexqual that
can be executed against the index-returned tuple without using any
non-returnable columns. (The restrictions imposed by check_index_only
guarantee this is possible, although we may have to recompute indexed
expressions.) Support construction of that during setrefs.c
processing by marking IndexOnlyScan.indextlist entries as resjunk
if they can't be returned, rather than removing them entirely.
(We could alternatively require setrefs.c to look up the IndexOptInfo
again, but abusing resjunk this way seems like a reasonably safe way
to avoid needing to do that.)
This solution isn't great from an API-stability standpoint: if there
are any extensions out there that build IndexOnlyScan structs directly,
they'll be broken in the next minor releases. However, only a very
invasive extension would be likely to do such a thing. There's no
change in the Path representation, so typical planner extensions
shouldn't have a problem.
As before, back-patch to all supported branches.
Discussion: https://postgr.es/m/3179992.1641150853@sss.pgh.pa.us
Discussion: https://postgr.es/m/17350-b5bdcf476e5badbb@postgresql.org
Replica identities that depend directly on an index rely on a set of
properties, one of them being that all the columns defined in this index
have to be marked as NOT NULL. There was a hole in the logic with ALTER
TABLE DROP NOT NULL, where it was possible to remove the NOT NULL
property of a column part of an index used as replica identity, so block
it to avoid problems with logical decoding down the road.
The same check was already done columns part of a primary key, so the
fix is straight-forward.
Author: Haiying Tang, Hou Zhijie
Reviewed-by: Dilip Kumar, Michael Paquier
Discussion: https://postgr.es/m/OS0PR01MB6113338C102BEE8B2FFC5BD9FB619@OS0PR01MB6113.jpnprd01.prod.outlook.com
Backpatch-through: 10
When changing REPLICA IDENTITY INDEX to another one, the target table's
relcache was not being invalidated. This leads to skipping update/delete
operations during apply on the subscriber side as the columns required to
search corresponding rows won't get logged.
Author: Tang Haiying, Hou Zhijie
Reviewed-by: Euler Taveira, Amit Kapila
Backpatch-through: 10
Discussion: https://postgr.es/m/OS0PR01MB61133CA11630DAE45BC6AD95FB939@OS0PR01MB6113.jpnprd01.prod.outlook.com
Commit 1b5d797cd4 intended to relax the lock level used to rename
indexes, but inadvertently allowed *any* relation to be renamed with a
lowered lock level, as long as the command is spelled ALTER INDEX.
That's undesirable for other relation types, so retry the operation with
the higher lock if the relation turns out not to be an index.
After this fix, ALTER INDEX <sometable> RENAME will require access
exclusive lock, which it didn't before.
Author: Nathan Bossart <bossartn@amazon.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Onder Kalaci <onderk@microsoft.com>
Discussion: https://postgr.es/m/PH0PR21MB1328189E2821CDEC646F8178D8AE9@PH0PR21MB1328.namprd21.prod.outlook.com
The grammar of this command run on indexes with column names has always
been authorized by the parser, and it has never been documented.
Since 911e702, it is possible to define opclass parameters as of CREATE
INDEX, which actually broke the old case of ALTER INDEX/TABLE where
relation-level parameters n_distinct and n_distinct_inherited could be
defined for an index (see 76a47c0 and its thread where this point has
been touched, still remained unused). Attempting to do that in v13~
would cause the index to become unusable, as there is a new dedicated
code path to load opclass parameters instead of the relation-level ones
previously available. Note that it is possible to fix things with a
manual catalog update to bring the relation back online.
This commit disables this command for now as the use of column names for
indexes does not make sense anyway, particularly when it comes to index
expressions where names are automatically computed. One way to properly
support this case properly in the future would be to use column numbers
when it comes to indexes, in the same way as ALTER INDEX .. ALTER COLUMN
.. SET STATISTICS.
Partitioned indexes were already blocked, but not indexes. Some tests
are added for both cases.
There was some code in ANALYZE to enforce n_distinct to be used for an
index expression if the parameter was defined, but just remove it for
now until/if there is support for this (note that index-level parameters
never had support in pg_dump either, previously), so this was just dead
code.
Reported-by: Matthijs van der Vleuten
Author: Nathan Bossart, Michael Paquier
Reviewed-by: Vik Fearing, Dilip Kumar
Discussion: https://postgr.es/m/17220-15d684c6c2171a83@postgresql.org
Backpatch-through: 13
Failing to do that, any direct inserts/updates of those partitions
would fail to enforce the correct constraint, that is, one that
considers the new partition constraint of their parent table.
Backpatch to 10.
Reported by: Hou Zhijie <houzj.fnst@fujitsu.com>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Nitin Jadhav <nitinjadhavpostgres@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Discussion: https://postgr.es/m/OS3PR01MB5718DA1C4609A25186D1FBF194089%40OS3PR01MB5718.jpnprd01.prod.outlook.com
An extension may want to call GetSecurityLabel() on a shared object
before the shared relcaches are fully initialized. For instance, a
ClientAuthentication_hook might want to retrieve the security label on
a role.
Discussion: https://postgr.es/m/ecb7af0b26e3be1d96d291c8453a86f1f82d9061.camel@j-davis.com
Backpatch-through: 9.6
Updates/Deletes on a partition were allowed even without replica identity
after the parent table was added to a publication. This would later lead
to an error on subscribers. The reason was that we were not invalidating
the partition's relcache and the publication information for partitions
was not getting rebuilt. Similarly, we were not invalidating the
partitions' relcache after dropping a partitioned table from a publication
which will prohibit Updates/Deletes on its partition without replica
identity even without any publication.
Reported-by: Haiying Tang
Author: Hou Zhijie and Vignesh C
Reviewed-by: Vignesh C and Amit Kapila
Backpatch-through: 13
Discussion: https://postgr.es/m/OS0PR01MB6113D77F583C922F1CEAA1C3FBD29@OS0PR01MB6113.jpnprd01.prod.outlook.com
Before commit 84f5c2908, a STABLE function in a plpgsql CALL
statement's argument list would see an up-to-date snapshot,
because exec_stmt_call would push a new snapshot. I got rid of
that because the possibility of the snapshot disappearing within
COMMIT made it too hard to manage a snapshot across the CALL
statement. That's fine so far as the procedure itself goes,
but I forgot to think about the possibility of STABLE functions
within the CALL argument list. As things now stand, those'll
be executed with the Portal's snapshot as ActiveSnapshot,
keeping them from seeing updates more recent than Portal startup.
(VOLATILE functions don't have a problem because they take their
own snapshots; which indeed is also why the procedure itself
doesn't have a problem. There are no STABLE procedures.)
We can fix this by pushing a new snapshot transiently within
ExecuteCallStmt itself. Popping the snapshot before we get
into the procedure proper eliminates the management problem.
The possibly-useless extra snapshot-grab is slightly annoying,
but it's no worse than what happened before 84f5c2908.
Per bug #17199 from Alexander Nawratil. Back-patch to v11,
like the previous patch.
Discussion: https://postgr.es/m/17199-1ab2561f0d94af92@postgresql.org
Formerly, we sent signals for outgoing NOTIFY messages within
ProcessCompletedNotifies, which was also responsible for sending
relevant ones of those messages to our connected client. It therefore
had to run during the main-loop processing that occurs just before
going idle. This arrangement had two big disadvantages:
* Now that procedures allow intra-command COMMITs, it would be
useful to send NOTIFYs to other sessions immediately at COMMIT
(though, for reasons of wire-protocol stability, we still shouldn't
forward them to our client until end of command).
* Background processes such as replication workers would not send
NOTIFYs at all, since they never execute the client communication
loop. We've had requests to allow triggers running in replication
workers to send NOTIFYs, so that's a problem.
To fix these things, move transmission of outgoing NOTIFY signals
into AtCommit_Notify, where it will happen during CommitTransaction.
Also move the possible call of asyncQueueAdvanceTail there, to
ensure we don't bloat the async SLRU if a background worker sends
many NOTIFYs with no one listening.
We can also drop the call of asyncQueueReadAllNotifications,
allowing ProcessCompletedNotifies to go away entirely. That's
because commit 790026972 added a call of ProcessNotifyInterrupt
adjacent to PostgresMain's call of ProcessCompletedNotifies,
and that does its own call of asyncQueueReadAllNotifications,
meaning that we were uselessly doing two such calls (inside two
separate transactions) whenever inbound notify signals coincided
with an outbound notify. We need only set notifyInterruptPending
to ensure that ProcessNotifyInterrupt runs, and we're done.
The existing documentation suggests that custom background workers
should call ProcessCompletedNotifies if they want to send NOTIFY
messages. To avoid an ABI break in the back branches, reduce it
to an empty routine rather than removing it entirely. Removal
will occur in v15.
Although the problems mentioned above have existed for awhile,
I don't feel comfortable back-patching this any further than v13.
There was quite a bit of churn in adjacent code between 12 and 13.
At minimum we'd have to also backpatch 51004c717, and a good deal
of other adjustment would also be needed, so the benefit-to-risk
ratio doesn't look attractive.
Per bug #15293 from Michael Powers (and similar gripes from others).
Artur Zakirov and Tom Lane
Discussion: https://postgr.es/m/153243441449.1404.2274116228506175596@wrigleys.postgresql.org
We have long forbidden fetching backwards from a NO SCROLL cursor,
but the prohibition didn't extend to cases in which we rewind the
query altogether and then re-fetch forwards. I think the reason is
that this logic was mainly meant to protect plan nodes that can't
be run in the reverse direction. However, re-reading the query output
is problematic if the query is volatile (which includes SELECT FOR
UPDATE, not just queries with volatile functions): the re-read can
produce different results, which confuses the cursor navigation logic
completely. Another reason for disliking this approach is that some
code paths will either fetch backwards or rewind-and-fetch-forwards
depending on the distance to the target row; so that seemingly
identical use-cases may or may not draw the "cursor can only scan
forward" error. Hence, let's clean things up by disallowing rewind
as well as fetch-backwards in a NO SCROLL cursor.
Ordinarily we'd only make such a definitional change in HEAD, but
there is a third reason to consider this change now. Commit ba2c6d6ce
created some new user-visible anomalies for non-scrollable cursors
WITH HOLD, in that navigation in the cursor result got confused if the
cursor had been partially read before committing. The only good way
to resolve those anomalies is to forbid rewinding such a cursor, which
allows removal of the incorrect cursor state manipulations that
ba2c6d6ce added to PersistHoldablePortal.
To minimize the behavioral change in the back branches (including
v14), refuse to rewind a NO SCROLL cursor only when it has a holdStore,
ie has been held over from a previous transaction due to WITH HOLD.
This should avoid breaking most applications that have been sloppy
about whether to declare cursors as scrollable. We'll enforce the
prohibition across-the-board beginning in v15.
Back-patch to v11, as ba2c6d6ce was.
Discussion: https://postgr.es/m/3712911.1631207435@sss.pgh.pa.us
Some plan node types don't react well to being called again after
they've already returned NULL. PortalRunSelect() has long dealt
with this by calling the executor with NoMovementScanDirection
if it sees that we've already run the portal to the end. However,
commit ba2c6d6ce overlooked this point, so that persisting an
already-fully-fetched cursor would fail if it had such a plan.
Per report from Tomas Barton. Back-patch to v11, as the faulty
commit was. (I've omitted a test case because the type of plan
that causes a problem isn't all that stable.)
Discussion: https://postgr.es/m/CAPV2KRjd=ErgVGbvO2Ty20tKTEZZr6cYsYLxgN_W3eAo9pf5sw@mail.gmail.com
Updates/Deletes on a relation were allowed even without replica identity
after we define the publication for all tables. This would later lead to
an error on subscribers. The reason was that for such publications we were
not invalidating the relcache and the publication information for
relations was not getting rebuilt. Similarly, we were not invalidating the
relcache after dropping of such publications which will prohibit
Updates/Deletes without replica identity even without any publication.
Author: Vignesh C and Hou Zhijie
Reviewed-by: Hou Zhijie, Kyotaro Horiguchi, Amit Kapila
Backpatch-through: 10, where it was introduced
Discussion: https://postgr.es/m/CALDaNm0pF6zeWqCA8TCe2sDuwFAy8fCqba=nHampCKag-qLixg@mail.gmail.com
Previously this was allowed, but the collation effectively vanished
into the ether because of the way lookup_collation() works: you could
not use the collation, nor even drop it. Seems better to give an
error up front than to leave the user wondering why it doesn't work.
(Because this test is in DefineCollation not CreateCollation, it does
not prevent pg_import_system_collations from creating ICU collations,
regardless of the initially-chosen encoding.)
Per bug #17170 from Andrew Bille. Back-patch to v10 where ICU support
was added.
Discussion: https://postgr.es/m/17170-95845cf3f0a9c36d@postgresql.org
If the system crashed between CREATE TABLESPACE and the next checkpoint,
the result could be some files in the tablespace unexpectedly containing
no rows. Affected files would be those for which the system did not
write WAL; see the wal_skip_threshold documentation. Before v13, a
different set of conditions governed the writing of WAL; see v12's
<sect2 id="populate-pitr">. (The v12 conditions were broader in some
ways and narrower in others.) Users may want to audit non-default
tablespaces for unexpected short files. The bug could have truncated an
index without affecting the associated table, and reindexing the index
would fix that particular problem.
This fixes the bug by making create_tablespace_directories() more like
TablespaceCreateDbspace(). create_tablespace_directories() was
recursively removing tablespace contents, reasoning that WAL redo would
recreate everything removed that way. That assumption holds for other
wal_level values. Under wal_level=minimal, the old approach could
delete files for which no other copy existed. Back-patch to 9.6 (all
supported versions).
Reviewed by Robert Haas and Prabhat Sahu. Reported by Robert Haas.
Discussion: https://postgr.es/m/CA+TgmoaLO9ncuwvr2nN-J4VEP5XyAcy=zKiHxQzBbFRxxGxm0w@mail.gmail.com
Commit 325f2ec555 introduced pg_class.relwrite to skip operations on
tables created as part of a heap rewrite during DDL. It links such
transient heaps to the original relation OID via this new field in
pg_class but forgot to do anything about toast tables. So, logical
decoding was not able to skip operations on internally created toast
tables. This leads to an error when we tried to decode the WAL for the
next operation for which it appeared that there is a toast data where
actually it didn't have any toast data.
To fix this, we set pg_class.relwrite for internally created toast tables
as well which allowed skipping operations on them during logical decoding.
Author: Bertrand Drouvot
Reviewed-by: David Zhang, Amit Kapila
Backpatch-through: 11, where it was introduced
Discussion: https://postgr.es/m/b5146fb1-ad9e-7d6e-f980-98ed68744a7c@amazon.com
If recordDependencyOnCurrentExtension is invoked on a pre-existing,
free-standing object during an extension update script, that object
will become owned by the extension. In our current code this is
possible in three cases:
* Replacing a "shell" type or operator.
* CREATE OR REPLACE overwriting an existing object.
* ALTER TYPE SET, ALTER DOMAIN SET, and ALTER OPERATOR SET.
The first of these cases is intentional behavior, as noted by the
existing comments for GenerateTypeDependencies. It seems like
appropriate behavior for CREATE OR REPLACE too; at least, the obvious
alternatives are not better. However, the fact that it happens during
ALTER is an artifact of trying to share code (GenerateTypeDependencies
and makeOperatorDependencies) between the CREATE and ALTER cases.
Since an extension script would be unlikely to ALTER an object that
didn't already belong to the extension, this behavior is not very
troubling for the direct target object ... but ALTER TYPE SET will
recurse to dependent domains, and it is very uncool for those to
become owned by the extension if they were not already.
Let's fix this by redefining the ALTER cases to never change extension
membership, full stop. We could minimize the behavioral change by
only changing the behavior when ALTER TYPE SET is recursing to a
domain, but that would complicate the code and it does not seem like
a better definition.
Per bug #17144 from Alex Kozhemyakin. Back-patch to v13 where ALTER
TYPE SET was added. (The other cases are older, but since they only
affect the directly-named object, there's not enough of a problem to
justify changing the behavior further back.)
Discussion: https://postgr.es/m/17144-e67d7a8f049de9af@postgresql.org
Rather than trying to pick table aliases that won't conflict with
any possible user-defined matview column name, adjust the queries'
syntax so that the aliases are only used in places where they can't be
mistaken for column names. Mostly this consists of writing "alias.*"
not just "alias", which adds clarity for humans as well as machines.
We do have the issue that "SELECT alias.*" acts differently from
"SELECT alias", but we can use the same hack ruleutils.c uses for
whole-row variables in SELECT lists: write "alias.*::compositetype".
We might as well revert to the original aliases after doing this;
they're a bit easier to read.
Like 75d66d10e, back-patch to all supported branches.
Discussion: https://postgr.es/m/2488325.1628261320@sss.pgh.pa.us
We don't allow to create replication slot_name as an empty string ('') via
SQL API pg_create_logical_replication_slot() but it is allowed to be set
via Alter Subscription command. This will lead to apply worker repeatedly
keep trying to stream data via slot_name '' and the user is not allowed to
create the slot with that name.
Author: Japin Li
Reviewed-By: Ranier Vilela, Amit Kapila
Backpatch-through: 10, where it was introduced
Discussion: https://postgr.es/m/MEYP282MB1669CBD98E721C77CA696499B61A9@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
When triggers are cloned from partitioned tables to their partitions,
the 'tgenabled' flag (origin/replica/always/disable) was not propagated.
Make it so that the flag on the trigger on partition is initially set to
the same value as on the partitioned table.
Add a test case to verify the behavior.
Backpatch to 11, where this appeared in commit 86f575948c.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20200930223450.GA14848@telsasoft.com
Some commands of ALTER TABLE could fail with the following error:
ERROR: "tab" is of the wrong type
This error is unexpected, as all the code paths leading to
ATWrongRelkindError() should use a supported set of relkinds to generate
correct error messages. This commit closes the gap with such mistakes,
by adding all the missing relkind combinations. Tests are added to
check all the problems found. Note that some combinations are not used,
but these are left around as it could have an impact on applications
relying on this code.
2ed532e has done a much larger refactoring on HEAD to make such error
messages easier to manage in the long-term, so nothing is needed there.
Author: Kyotaro Horiguchi
Reviewed-by: Peter Eisentraut, Ahsan Hadi, Michael Paquier
Discussion: https://postgr.es/m/20210216.181415.368926598204753659.horikyota.ntt@gmail.com
Backpatch-through: 11
Although we were careful to lock the object being added or dropped,
we failed to get any sort of lock on the extension itself. This
allowed the ALTER to proceed in parallel with a DROP EXTENSION,
which is problematic for a couple of reasons. If both commands
succeeded we'd be left with a dangling link in pg_depend, which
would cause problems later. Also, if the ALTER failed for some
reason, it might try to print the extension's name, and that could
result in a crash or (in older branches) a silly error message
complaining about extension "(null)".
Per bug #17098 from Alexander Lakhin. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/17098-b960f3616c861f83@postgresql.org
It's not really necessary for this function to open or lock the
relation associated with the pg_policy entry it's modifying. The
error checks it's making on the rel are if anything counterproductive
(e.g., if we don't want to allow installation of policies on system
catalogs, here is not the place to prevent that). In particular, it
seems just wrong to insist on an ownership check. That has the net
effect of forcing people to use superuser for DROP OWNED BY, which
surely is not an effect we want. Also there is no point in rebuilding
the dependencies of the policy expressions, which aren't being
changed. Lastly, locking the table also seems counterproductive; it's
not helping to prevent race conditions, since we failed to re-read the
pg_policy row after acquiring the lock. That means that concurrent
DDL would likely result in "tuple concurrently updated/deleted"
errors; which is the same behavior this code will produce, with less
overhead.
Per discussion of bug #17062. Back-patch to all supported versions,
as the failure cases this eliminates seem just as undesirable in 9.6
as in HEAD.
Discussion: https://postgr.es/m/1573181.1624220108@sss.pgh.pa.us
Ordinarily, a pg_policy.polroles array wouldn't list the same role
more than once; but CREATE POLICY does not prevent that. If we
perform DROP OWNED BY on a role that is listed more than once,
RemoveRoleFromObjectPolicy either suffered an assertion failure
or encountered a tuple-updated-by-self error. Rewrite it to cope
correctly with duplicate entries, and add a CommandCounterIncrement
call to prevent the other problem.
Per discussion, there's other cleanup that ought to happen here,
but this seems like the minimum essential fix.
Per bug #17062 from Alexander Lakhin. It's been broken all along,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/17062-11f471ae3199ca23@postgresql.org
This works fine in the "simple Query" code path; but if the
statement is in the plan cache then it's corrupted for future
re-execution. Apply copyObject() to protect the original
tree from modification, as we've done elsewhere.
This narrow fix is applied only to the back branches. In HEAD,
the problem was fixed more generally by commit 7c337b6b5; but
that changed ProcessUtility's API, so it's infeasible to
back-patch.
Per bug #17053 from Charles Samborski.
Discussion: https://postgr.es/m/931771.1623893989@sss.pgh.pa.us
Discussion: https://postgr.es/m/17053-3ca3f501bbc212b4@postgresql.org
The fast default code added in Release 11 omitted to check that the
table a fast default was being added to was a plain table. Thus one
could be added to a foreign table, which predicably blows up. Here we
perform that check.
In addition, on the back branches, since some of these might have
escaped into the wild, if we encounter a missing value for
an attribute of something other than a plain table we ignore it.
Fixes bug #17056
Backpatch to release 11,
Reviewed by: Andres Freund, Álvaro Herrera and Tom Lane
When stuffing a plan from the plancache into a Portal, one is
not supposed to risk throwing an error between GetCachedPlan and
PortalDefineQuery; if that happens, the plan refcount incremented
by GetCachedPlan will be leaked. I managed to break this rule
while refactoring code in 9dbf2b7d7. There is no visible
consequence other than some memory leakage, and since nobody is
very likely to trigger the relevant error conditions many times
in a row, it's not surprising we haven't noticed. Nonetheless,
it's a bug, so rearrange the order of operations to remove the
hazard.
Noted on the way to looking for a better fix for bug #17053.
This mistake is pretty old, so back-patch to all supported
branches.
PersistHoldablePortal has long assumed that it should store the
entire output of the query-to-be-persisted, which requires rewinding
and re-reading the output. This is problematic if the query is not
stable: we might get different row contents, or even a different
number of rows, which'd confuse the cursor state mightily.
In the case where the cursor is NO SCROLL, this is very easy to
solve: just store the remaining query output, without any rewinding,
and tweak the portal's cursor state to match. Aside from removing
the semantic problem, this could be significantly more efficient
than storing the whole output.
If the cursor is scrollable, there's not much we can do, but it
was already the case that scrolling a volatile query's result was
pretty unsafe. We can just document more clearly that getting
correct results from that is not guaranteed.
There are already prohibitions in place on using SCROLL with
FOR UPDATE/SHARE, which is one way for a SELECT query to have
non-stable results. We could imagine prohibiting SCROLL when
the query contains volatile functions, but that would be
expensive to enforce. Moreover, it could break applications
that work just fine, if they have functions that are in fact
stable but the user neglected to mark them so. So settle for
documenting the hazard.
While this problem has existed in some guise for a long time,
it got a lot worse in v11, which introduced the possibility
of persisting plpgsql cursors (perhaps implicit ones) even
when they violate the rules for what can be marked WITH HOLD.
Hence, I've chosen to back-patch to v11 but not further.
Per bug #17050 from Алексей Булгаков.
Discussion: https://postgr.es/m/17050-f77aa827dc85247c@postgresql.org
The internal SQL queries used by REFRESH MATERIALIZED VIEW CONCURRENTLY
include some aliases for its diff and temporary relations with
rather-generic names: diff, newdata, newdata2 and mv. Depending on the
queries used for the materialized view, using CONCURRENTLY could lead to
some internal failures if the query and those internal aliases conflict.
Those names have been chosen in 841c29c8. This commit switches instead
to a naming pattern which is less likely going to cause conflicts, based
on an idea from Thomas Munro, by appending _$ to those aliases. This is
not perfect as those new names could still conflict, but at least it has
the advantage to keep the code readable and simple while reducing the
likelihood of conflicts to be close to zero.
Reported-by: Mathis Rudolf
Author: Bharath Rupireddy
Reviewed-by: Bernd Helmle, Thomas Munro, Michael Paquier
Discussion: https://postgr.es/m/109c267a-10d2-3c53-b60e-720fcf44d9e8@credativ.de
Backpatch-through: 9.6
The error messages, docs, and one of the options were using
'parallel degree' to indicate parallelism used by vacuum command. We
normally use 'parallel workers' at other places so change it for parallel
vacuum accordingly.
Author: Bharath Rupireddy
Reviewed-by: Dilip Kumar, Amit Kapila
Backpatch-through: 13
Discussion: https://postgr.es/m/CALj2ACWz=PYrrFXVsEKb9J1aiX4raA+UBe02hdRp_zqDkrWUiw@mail.gmail.com
If we redirected a replicated tuple operation into a partition child
table, and then tried to fire AFTER triggers for that event, the
relation cache entry for the child table was already closed. This has
no visible ill effects as long as the entry is still there and still
valid, but an unluckily-timed cache flush could result in a crash or
other misbehavior.
To fix, postpone the ExecCleanupTupleRouting call (which is what
closes the child table) until after we've fired triggers. This
requires a bit of refactoring so that the cleanup function can
have access to the necessary state.
In HEAD, I took the opportunity to simplify some of worker.c's
function APIs based on use of the new ApplyExecutionData struct.
However, it doesn't seem safe/practical to back-patch that aspect,
at least not without a lot of analysis of possible interactions
with a04daa97a.
In passing, add an Assert to afterTriggerInvokeEvents to catch
such cases. This seems worthwhile because we've grown a number
of fairly unstructured ways of calling AfterTriggerEndQuery.
Back-patch to v13, where worker.c grew the ability to deal with
partitioned target tables.
Discussion: https://postgr.es/m/3382681.1621381328@sss.pgh.pa.us
We consider this supported (though I've got my doubts that it's a
good idea, because tableoid is not immutable). However, several
code paths failed to fill the field in soon enough, causing such
a GENERATED expression to see zero or the wrong value. This
occurred when ALTER TABLE adds a new GENERATED column to a table
with existing rows, and during regular INSERT or UPDATE on a
foreign table with GENERATED columns.
Noted during investigation of a report from Vitaly Ustinov.
Back-patch to v12 where GENERATED came in.
Discussion: https://postgr.es/m/CAM_DEiWR2DPT6U4xb-Ehigozzd3n3G37ZB1+867zbsEVtYoJww@mail.gmail.com
COMMIT/ROLLBACK necessarily destroys all snapshots within the session.
The original implementation of intra-procedure transactions just
cavalierly did that, ignoring the fact that this left us executing in
a rather different environment than normal. In particular, it turns
out that handling of toasted datums depends rather critically on there
being an outer ActiveSnapshot: otherwise, when SPI or the core
executor pop whatever snapshot they used and return, it's unsafe to
dereference any toasted datums that may appear in the query result.
It's possible to demonstrate "no known snapshots" and "missing chunk
number N for toast value" errors as a result of this oversight.
Historically this outer snapshot has been held by the Portal code,
and that seems like a good plan to preserve. So add infrastructure
to pquery.c to allow re-establishing the Portal-owned snapshot if it's
not there anymore, and add enough bookkeeping support that we can tell
whether it is or not.
We can't, however, just re-establish the Portal snapshot as part of
COMMIT/ROLLBACK. As in normal transaction start, acquiring the first
snapshot should wait until after SET and LOCK commands. Hence, teach
spi.c about doing this at the right time. (Note that this patch
doesn't fix the problem for any PLs that try to run intra-procedure
transactions without using SPI to execute SQL commands.)
This makes SPI's no_snapshots parameter rather a misnomer, so in HEAD,
rename that to allow_nonatomic.
replication/logical/worker.c also needs some fixes, because it wasn't
careful to hold a snapshot open around AFTER trigger execution.
That code doesn't use a Portal, which I suspect someday we're gonna
have to fix. But for now, just rearrange the order of operations.
This includes back-patching the recent addition of finish_estate()
to centralize the cleanup logic there.
This also back-patches commit 2ecfeda3e into v13, to improve the
test coverage for worker.c (it was that test that exposed that
worker.c's snapshot management is wrong).
Per bug #15990 from Andreas Wicht. Back-patch to v11 where
intra-procedure COMMIT was added.
Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
This patch replaces use of the global "wrconn" variable in
AlterSubscription_refresh with a local variable of the same name, making
it consistent with other functions in subscriptioncmds.c (e.g.
DropSubscription).
The global wrconn is only meant to be used for logical apply/tablesync worker.
Abusing it this way is known to cause trouble if an apply worker
manages to do a subscription refresh, such as reported by Jeremy Finzel
and diagnosed by Andres Freund back in November 2020, at
https://www.postgresql.org/message-id/20201111215820.qihhrz7fayu6myfi@alap3.anarazel.de
Backpatch to 10. In branch master, also move the connection establishment
to occur outside the PG_TRY block; this way we can remove a test for NULL in
PG_FINALLY, and it also makes the code more consistent with similar code in
the same file.
Author: Peter Smith <peter.b.smith@fujitsu.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Discussion: https://postgr.es/m/CAHut+Pu7Jv9L2BOEx_Z0UtJxfDevQSAUW2mJqWU+CtmDrEZVAg@mail.gmail.com
When ALTER TABLE .. ALTER CONSTRAINT changes deferrability properties
changed in a partitioned table, we failed to propagate those changes
correctly to partitions and to triggers. Repair by adding a recursion
mechanism to affect all derived constraints and all derived triggers.
(In particular, recurse to partitions even if their respective parents
are already in the desired state: it is possible for the partitions to
have been altered individually.) Because foreign keys involve tables in
two sides, we cannot use the standard ALTER TABLE recursion mechanism,
so we invent our own by following pg_constraint.conparentid down.
When ALTER TABLE .. ALTER CONSTRAINT is invoked on the derived
pg_constraint object that's automaticaly created in a partition as a
result of a constraint added to its parent, raise an error instead of
pretending to work and then failing to modify all the affected triggers.
Before this commit such a command would be allowed but failed to affect
all triggers, so it would silently misbehave. (Restoring dumps of
existing databases is not affected, because pg_dump does not produce
anything for such a derived constraint anyway.)
Add some tests for the case.
Backpatch to 11, where foreign key support was added to partitioned
tables by commit 3de241dba8. (A related change is commit f56f8f8da6
in pg12 which added support for FKs *referencing* partitioned tables;
this is what forces us to use an ad-hoc recursion mechanism for this.)
Diagnosed by Tom Lane from bug report from Ron L Johnson. As of this
writing, no reviews were offered.
Discussion: https://postgr.es/m/75fe0761-a291-86a9-c8d8-4906da077469@gmail.com
Discussion: https://postgr.es/m/3144850.1607369633@sss.pgh.pa.us
The OID of the constraint is used instead of the OID of the trigger --
an easy mistake to make. Apparently the object-alter hooks are not very
well tested :-(
Backpatch to 12, where this typo was introduced by 578b229718
Discussion: https://postgr.es/m/20210503231633.GA6994@alvherre.pgsql
When running ALTER TABLE t2 INHERIT t1, we must check that columns in
t2 that correspond to a generated column in t1 are also generated and
have the same generation expression. Otherwise, this would allow
creating setups that a normal CREATE TABLE sequence would not allow.
Discussion: https://www.postgresql.org/message-id/22de27f6-7096-8d96-4619-7b882932ca25@2ndquadrant.com
Most GUC check hooks that inspect database state have special checks
that prevent them from throwing hard errors for state-dependent issues
when source == PGC_S_TEST. This allows, for example,
"ALTER DATABASE d SET default_text_search_config = foo" when the "foo"
configuration hasn't been created yet. Without this, we have problems
during dump/reload or pg_upgrade, because pg_dump has no idea about
possible dependencies of GUC values and can't ensure a safe restore
ordering.
However, check_role() and check_session_authorization() hadn't gotten
the memo about that, and would throw hard errors anyway. It's not
entirely clear what is the use-case for "ALTER ROLE x SET role = y",
but we've now heard two independent complaints about that bollixing
an upgrade, so apparently some people are doing it.
Hence, fix these two functions to act more like other check hooks
with similar needs. (But I did not change their insistence on
being inside a transaction, as it's still not apparent that setting
either GUC from the configuration file would be wise.)
Also fix check_temp_buffers, which had a different form of the disease
of making state-dependent checks without any exception for PGC_S_TEST.
A cursory survey of other GUC check hooks did not find any more issues
of this ilk. (There are a lot of interdependencies among
PGC_POSTMASTER and PGC_SIGHUP GUCs, which may be a bad idea, but
they're not relevant to the immediate concern because they can't be
set via ALTER ROLE/DATABASE.)
Per reports from Charlie Hornsby and Nathan Bossart. Back-patch
to all supported branches.
Discussion: https://postgr.es/m/HE1P189MB0523B31598B0C772C908088DB7709@HE1P189MB0523.EURP189.PROD.OUTLOOK.COM
Discussion: https://postgr.es/m/20160711223641.1426.86096@wrigleys.postgresql.org
I introduced this duplicate code in commit 8b08f7d482 for no good
reason. Remove it, and backpatch to 11 where it was introduced.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
vacuumlazy.c sometimes fails to update pg_class entries for each index
(to ensure that pg_class.reltuples is current), even though analyze.c
assumed that that must have happened during VACUUM ANALYZE. There are
at least a couple of reasons for this. For example, vacuumlazy.c could
fail to update pg_class when the index AM indicated that its statistics
are merely an estimate, per the contract for amvacuumcleanup() routines
established by commit e57345975c back in 2006.
Stop assuming that pg_class must have been updated with accurate
statistics within VACUUM ANALYZE -- update pg_class for indexes at the
same time as the table relation in all cases. That way VACUUM ANALYZE
will never fail to keep pg_class.reltuples reasonably accurate.
The only downside of this approach (compared to the old approach) is
that it might inaccurately set pg_class.reltuples for indexes whose heap
relation ends up with the same inaccurate value anyway. This doesn't
seem too bad. We already consistently called vac_update_relstats() (to
update pg_class) for the heap/table relation twice during any VACUUM
ANALYZE -- once in vacuumlazy.c, and once in analyze.c. We now make
sure that we call vac_update_relstats() at least once (though often
twice) for each index.
This is follow up work to commit 9f3665fb, which dealt with issues in
btvacuumcleanup(). Technically this fixes an unrelated issue, though.
btvacuumcleanup() no longer provides an accurate num_index_tuples value
following commit 9f3665fb (when there was no btbulkdelete() call during
the VACUUM operation in question), but hashvacuumcleanup() has worked in
the same way for many years now.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAH2-WzknxdComjhqo4SUxVFk_Q1171GJO2ZgHZ1Y6pion6u8rA@mail.gmail.com
Backpatch: 13-, just like commit 9f3665fb.
"SELECT pg_import_system_collations(0)" caused an assertion failure.
With a random nonzero argument --- or indeed with zero, in non-assert
builds --- it would happily make pg_collation entries with garbage
values of collnamespace. These are harmless as far as I can tell
(unless maybe the OID happens to become used for a schema, later on?).
In any case this isn't a security issue, since the function is
superuser-only. But it seems like a gotcha for unwary DBAs, so let's
add a check that the given OID belongs to some schema.
Back-patch to v10 where this function was introduced.
AfterTriggerSaveEvent() wrongly allocates the slot in execution-span
memory context, whereas the correct thing is to allocate it in
a transaction-span context, because that's where the enclosing
AfterTriggersTableData instance belongs into.
Backpatch to 12 (the test back to 11, where it works well with no code
changes, and it's good to have to confirm that the case was previously
well supported); this bug seems introduced by commit ff11e7f4b9.
Reported-by: Bertrand Drouvot <bdrouvot@amazon.com>
Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/39a71864-b120-5a5c-8cc5-c632b6f16761@amazon.com
If a cross-partition UPDATE violates a constraint on the target partition,
and the columns in the new partition are in different physical order than
in the parent, the error message can reveal columns that the user does not
have SELECT permission on. A similar bug was fixed earlier in commit
804b6b6db4.
The cause of the bug is that the callers of the
ExecBuildSlotValueDescription() function got confused when constructing
the list of modified columns. If the tuple was routed from a parent, we
converted the tuple to the parent's format, but the list of modified
columns was grabbed directly from the child's RTE entry.
ExecUpdateLockMode() had a similar issue. That lead to confusion on which
columns are key columns, leading to wrong tuple lock being taken on tables
referenced by foreign keys, when a row is updated with INSERT ON CONFLICT
UPDATE. A new isolation test is added for that corner case.
With this patch, the ri_RangeTableIndex field is no longer set for
partitions that don't have an entry in the range table. Previously, it was
set to the RTE entry of the parent relation, but that was confusing.
NOTE: This modifies the ResultRelInfo struct, replacing the
ri_PartitionRoot field with ri_RootResultRelInfo. That's a bit risky to
backpatch, because it breaks any extensions accessing the field. The
change that ri_RangeTableIndex is not set for partitions could potentially
break extensions, too. The ResultRelInfos are visible to FDWs at least,
and this patch required small changes to postgres_fdw. Nevertheless, this
seem like the least bad option. I don't think these fields widely used in
extensions; I don't think there are FDWs out there that uses the FDW
"direct update" API, other than postgres_fdw. If there is, you will get a
compilation error, so hopefully it is caught quickly.
Backpatch to 11, where support for both cross-partition UPDATEs, and unique
indexes on partitioned tables, were added.
Reviewed-by: Amit Langote
Security: CVE-2021-3393
If a multi-byte character is escaped with a backslash in TEXT mode input,
and the encoding is one of the client-only encodings where the bytes after
the first one can have an ASCII byte "embedded" in the char, we didn't
skip the character correctly. After a backslash, we only skipped the first
byte of the next character, so if it was a multi-byte character, we would
try to process its second byte as if it was a separate character. If it
was one of the characters with special meaning, like '\n', '\r', or
another '\\', that would cause trouble.
One such exmple is the byte sequence '\x5ca45c2e666f6f' in Big5 encoding.
That's supposed to be [backslash][two-byte character][.][f][o][o], but
because the second byte of the two-byte character is 0x5c, we incorrectly
treat it as another backslash. And because the next character is a dot, we
parse it as end-of-copy marker, and throw an "end-of-copy marker corrupt"
error.
Backpatch to all supported versions.
Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
In trying to protect the user from inconsistent behavior, commit
487e9861d0 "Enable BEFORE row-level triggers for partitioned tables"
tried to prevent BEFORE UPDATE FOR EACH ROW triggers from moving the row
from one partition to another. However, it turns out that the
restriction is wrong in two ways: first, it fails spuriously, preventing
valid situations from working, as in bug #16794; and second, they don't
protect from any misbehavior, because tuple routing would cope anyway.
Fix by removing that restriction.
We keep the same restriction on BEFORE INSERT FOR EACH ROW triggers,
though. It is valid and useful there. In the future we could remove it
by having tuple reroute work for inserts as it does for updates.
Backpatch to 13.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Phillip Menke <pg@pmenke.de>
Discussion: https://postgr.es/m/16794-350a655580fbb9ae@postgresql.org
Every core SLRU wraps around. With the exception of pg_notify, the wrap
point can fall in the middle of a page. Account for this in the
PagePrecedes callback specification and in SimpleLruTruncate()'s use of
said callback. Update each callback implementation to fit the new
specification. This changes SerialPagePrecedesLogically() from the
style of asyncQueuePagePrecedes() to the style of CLOGPagePrecedes().
(Whereas pg_clog and pg_serial share a key space, pg_serial is nothing
like pg_notify.) The bug fixed here has the same symptoms and user
followup steps as 592a589a04. Back-patch
to 9.5 (all supported versions).
Reviewed by Andrey Borodin and (in earlier versions) by Tom Lane.
Discussion: https://postgr.es/m/20190202083822.GC32531@gust.leadboat.com
Add a check that CREATE STATISTICS does not add extended statistics on
system catalogs, similarly to indexes etc. It can be overriden using
the allow_system_table_mods GUC.
This bug exists since 7b504eb282, adding the extended statistics, so
backpatch all the way back to PostgreSQL 10.
Author: Tomas Vondra
Reported-by: Dean Rasheed
Backpatch-through: 10
Discussion: https://postgr.es/m/CAEZATCXAPrrOKwEsyZKQ4uzzJQWBCt6QAvOcgqRGdWwT1zb%2BrQ%40mail.gmail.com
When a tablespace is used in a partitioned relation (per commits
ca4103025d in pg12 for tables and 33e6c34c32 in pg11 for indexes),
it is possible to drop the tablespace, potentially causing various
problems. One such was reported in bug #16577, where a rewriting ALTER
TABLE causes a server crash.
Protect against this by using pg_shdepend to keep track of tablespaces
when used for relations that don't keep physical files; we now abort a
tablespace if we see that the tablespace is referenced from any
partitioned relations.
Backpatch this to 11, where this problem has been latent all along. We
don't try to create pg_shdepend entries for existing partitioned
indexes/tables, but any ones that are modified going forward will be
protected.
Note slight behavior change: when trying to drop a tablespace that
contains both regular tables as well as partitioned ones, you'd
previously get ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE and now you'll
get ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST. Arguably, the latter is more
correct.
It is possible to add protecting pg_shdepend entries for existing
tables/indexes, by doing
ALTER TABLE ONLY some_partitioned_table SET TABLESPACE pg_default;
ALTER TABLE ONLY some_partitioned_table SET TABLESPACE original_tablespace;
for each partitioned table/index that is not in the database default
tablespace. Because these partitioned objects do not have storage, no
file needs to be actually moved, so it shouldn't take more time than
what's required to acquire locks.
This query can be used to search for such relations:
SELECT ... FROM pg_class WHERE relkind IN ('p', 'I') AND reltablespace <> 0
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/16577-881633a9f9894fd5@postgresql.org
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Commit 566372b3d fixed some race conditions involving concurrent
SimpleLruTruncate calls, but it introduced new ones in async.c.
A newly-listening backend could attempt to read Notify SLRU pages that
were in process of being truncated, possibly causing an error. Also,
the QUEUE_TAIL pointer could become set to a value that's not equal to
the queue position of any backend. While that's fairly harmless in
v13 and up (thanks to commit 51004c717), in older branches it resulted
in near-permanent disabling of the queue truncation logic, so that
continued use of NOTIFY led to queue-fill warnings and eventual
inability to send any more notifies. (A server restart is enough to
make that go away, but it's still pretty unpleasant.)
The core of the problem is confusion about whether QUEUE_TAIL
represents the "logical" tail of the queue (i.e., the oldest
still-interesting data) or the "physical" tail (the oldest data we've
not yet truncated away). To fix, split that into two variables.
QUEUE_TAIL regains its definition as the logical tail, and we
introduce a new variable to track the oldest un-truncated page.
Per report from Mikael Gustavsson. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/1b8561412e8a4f038d7a491c8b922788@smhi.se
This was evidently missed in commit 6337865f3, which generally did
s/TRUE/true/ everywhere. It escaped notice up to now because ICU
versions before ICU 68 provided definitions of "TRUE" and "FALSE"
regardless. With ICU 68, it fails to compile.
Per report from Condor. Back-patch to v11 where 6337865f3 came in.
(I've not tested v10, where this call originated, but I imagine
it's fine since we defined TRUE in c.h back then.)
Discussion: https://postgr.es/m/7a6f3336165bfe3ca66abcda7966f9d0@stz-bg.com
These flags should be independent: in particular an index AM should
be able to say that it supports include columns without necessarily
supporting multiple key columns. The included-columns patch got
this wrong, possibly aided by the fact that it didn't bother to
update the documentation.
While here, clarify some text about amcanreturn, which was a little
vague about what should happen when amcanreturn reports that only
some of the index columns are returnable.
Noted while reviewing the SP-GiST included-columns patch, which
quite incorrectly (and unsafely) changed SP-GiST to claim
amcanmulticol = true as a workaround for this bug.
Backpatch to v11 where included columns were introduced.
Specifically, this blocks DECLARE ... WITH HOLD and firing of deferred
triggers within index expressions and materialized view queries. An
attacker having permission to create non-temp objects in at least one
schema could execute arbitrary SQL functions under the identity of the
bootstrap superuser. One can work around the vulnerability by disabling
autovacuum and not manually running ANALYZE, CLUSTER, REINDEX, CREATE
INDEX, VACUUM FULL, or REFRESH MATERIALIZED VIEW. (Don't restore from
pg_dump, since it runs some of those commands.) Plain VACUUM (without
FULL) is safe, and all commands are fine when a trusted user owns the
target object. Performance may degrade quickly under this workaround,
however. Back-patch to 9.5 (all supported versions).
Reviewed by Robert Haas. Reported by Etienne Stalmans.
Security: CVE-2020-25695
This back-patches commit 20d3fe900 into the v12 and v13 branches.
At the time I thought that commit was not fixing any observable
bug, but Bertrand Drouvot showed otherwise: adding a dropped column
to the previously-considered scenario crashes v12 and v13, unless the
dropped column happens to be an integer. That is, of course, because
the tupdesc we derive from the plan output tlist fails to describe
the dropped column accurately, so that we'll do the wrong thing with
a tuple in which that column isn't NULL.
There is no bug in pre-v12 branches because they already did use
the table's real tuple descriptor for any trigger-returned tuple.
It seems that this set of bugs can be blamed on the changes that
removed es_trig_tuple_slot, though I've not attempted to pin that
down precisely.
Although there's no code change needed in HEAD, update the test case
to include a dropped column there too.
Discussion: https://postgr.es/m/db5d97c8-f48a-51e2-7b08-b73d5434d425@amazon.com
Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
* Avoid pointlessly highlighting that an index vacuum was executed by a
parallel worker; user doesn't care.
* Don't give the impression that a non-concurrent reindex of an invalid
index on a TOAST table would work, because it wouldn't.
* Add a "translator:" comment for a mysterious message.
Discussion: https://postgr.es/m/20201107034943.GA16596@alvherre.pgsql
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Revert 59ab4ac32, as well as the followup fix 33862cb9c, in all
branches. We need to think a bit harder about what the behavior
of LOCK TABLE on views should be, and there's no time for that
before next week's releases. We'll take another crack at this
later.
Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
LOCK TABLE has complained about "infinite recursion" when applied
to a self-referential view, ever since we made it recurse into views
in v11. However, that breaks pg_dump's new assumption that it's
okay to lock every relation. There doesn't seem to be any good
reason to throw an error: if we just abandon the recursion, we've
still satisfied the requirement of locking every referenced relation.
Per bug #16703 from Andrew Bille (via Alexander Lakhin).
Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
The intention in commit 491c029db was to require superuserness to
change the BYPASSRLS property, but the actual effect of the coding
in AlterRole() was to require superuserness to change anything at all
about a BYPASSRLS role. Other properties of a BYPASSRLS role should
be changeable under the same rules as for a normal role, though.
Fix that, and also take care of some documentation omissions related
to BYPASSRLS and REPLICATION role properties.
Tom Lane and Stephen Frost, per bug report from Wolfgang Walther.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/a5548a9f-89ee-3167-129d-162b5985fcf8@technowledgy.de
The current implementation cannot handle this correctly, so just
forbid it for now.
GENERATED clauses must be attached to the column definition and cannot
be added later like DEFAULT, so if a child table has a generation
expression that the parent does not have, the child column will
necessarily be an attlocal column. So to implement ALTER TABLE ONLY /
DROP EXPRESSION, we'd need extra code to update attislocal of the
direct child tables, somewhat similar to how DROP COLUMN does it, so
that the resulting state can be properly dumped and restored.
Discussion: https://www.postgresql.org/message-id/flat/15830.1575468847%40sss.pgh.pa.us
The restriction that only tables and views can be locked by LOCK TABLE
is quite arbitrary, since the underlying mechanism can lock any relation
type. Drop the restriction so that programs such as pg_dump can lock
all relations they're interested in, preventing schema changes that
could cause a dump to fail after expending much effort.
Backpatch to 9.5.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Wells Oliver <wells.oliver@gmail.com>
Discussion: https://postgr.es/m/20201021200659.GA32358@alvherre.pgsql
If the old row has any "missing" attributes that are supposed to
be retrieved from an associated tuple descriptor, the wrong things
happened because the trigger result is shoved directly into an
executor slot that lacks the missing-attribute data. Notably,
CHECK-constraint verification would incorrectly see those columns
as NULL, and so would RETURNING-list evaluation.
Band-aid around this by forcibly expanding the tuple before passing
it to the trigger function. (IMO it was a fundamental misdesign to
put the missing-attribute data into tuple constraints, which so
much of the system considers to be optional. But we're probably
stuck with that now, and will have to continue to apply band-aids
as we find other places with similar issues.)
Back-patch to v12. v11 would also have the issue, except that
commit 920311ab1 already applied a similar band-aid. That forced
expansion in more cases than seem really necessary, though, so
this isn't a directly equivalent fix.
Amit Langote, with some cosmetic changes by me
Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
The ExplainCloseGroup arguments for incremental sort usage data
didn't match the corresponding ExplainOpenGroup. This only matters
for XML-format output, which is probably why we'd not noticed.
Daniel Gustafsson, per bug #16683 from Frits Jalvingh
Discussion: https://postgr.es/m/16683-8005033324ad34e9@postgresql.org
More precisely, correctly handle the ONLY flag indicating not to
recurse. This was implemented in 86f575948c by recursing in
trigger.c, but that's the wrong place; use ATSimpleRecursion instead,
which behaves properly. However, because legacy inheritance has never
recursed in that situation, make sure to do that only for new-style
partitioning.
I noticed this problem while testing a fix for another bug in the
vicinity.
This has been wrong all along, so backpatch to 11.
Discussion: https://postgr.es/m/20201016235925.GA29829@alvherre.pgsql
The error message about columns in the primary key not including all of
the partition key was unclear; reword it.
Backpatch all the way to pg11, where it appeared.
Reported-by: Nagaraj Raj <nagaraj.sf@yahoo.com>
Discussion: https://postgr.es/m/64062533.78364.1601415362244@mail.yahoo.com
This addresses a couple of issues with the so-said subject:
- Report the correct parent relation with the index actually being
rebuilt or validated. Previously, the command status remained set to
the last index created for the progress of the index build and
validation, which would be incorrect when working on a table that has
more than one index.
- Use the correct phase when waiting before the drop of the old
indexes. Previously, this was reported with the same status as when
waiting before the old indexes are marked as dead.
Author: Matthias van de Meent, Michael Paquier
Discussion: https://postgr.es/m/CAEze2WhqFgcwe1_tv=sFYhLWV2AdpfukumotJ6JNcAOQs3jufg@mail.gmail.com
Backpatch-through: 12
We have a dozen or so places that need to iterate over all but the
first cell of a List. Prior to v13 this was typically written as
for_each_cell(lc, lnext(list_head(list)))
Commit 1cff1b95a changed these to
for_each_cell(lc, list, list_second_cell(list))
This patch introduces a new macro for_each_from() which expresses
the start point as a list index, allowing these to be written as
for_each_from(lc, list, 1)
This is marginally more efficient, since ForEachState.i can be
initialized directly instead of backing into it from a ListCell
address. It also seems clearer and less typo-prone.
Some of the remaining uses of for_each_cell() look like they could
profitably be changed to for_each_from(), but here I confined myself
to changing uses of list_second_cell().
Also, fix for_each_cell_setup() and for_both_cell_setup() to
const-ify their arguments; that's a simple oversight in 1cff1b95a.
Back-patch into v13, on the grounds that (1) the const-ification
is a minor bug fix, and (2) it's better for back-patching purposes
if we only have two ways to write these loops rather than three.
In HEAD, also remove list_third_cell() and list_fourth_cell(),
which were also introduced in 1cff1b95a, and are unused as of
cc99baa43. It seems unlikely that any third-party code would
have started to use them already; anyone who has can be directed
to list_nth_cell instead.
Discussion: https://postgr.es/m/CAApHDvpo1zj9KhEpU2cCRZfSM3Q6XGdhzuAS2v79PH7WJBkYVA@mail.gmail.com
This function leaked some memory while loading qual clauses for
an RLS policy. While ordinarily negligible, that could build up
in some repeated-reload cases, as reported by Konstantin Knizhnik.
We can improve matters by borrowing the coding long used in
RelationBuildRuleLock: build stringToNode's result directly in
the target context, and remember to explicitly pfree the
input string.
This patch by no means completely guarantees zero leaks within
this function, since we have no real guarantee that the catalog-
reading subroutines it calls don't leak anything. However,
practical tests suggest that this is enough to resolve the issue.
In any case, any remaining leaks are similar to those risked by
RelationBuildRuleLock and other relcache-loading subroutines.
If we need to fix them, we should adopt a more global approach
such as that used by the RECOVER_RELATION_BUILD_MEMORY hack.
While here, let's remove the need for an expensive PG_TRY block by
using MemoryContextSetParent to reparent an initially-short-lived
context for the RLS data.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/21356c12-8917-8249-b35f-1c447231922b@postgrespro.ru
If a partitioned table's column is already marked NOT NULL, there is
no need to examine its partitions, because we can rely on previous
DDL to have enforced that the child columns are NOT NULL as well.
(Unfortunately, the same cannot be said for traditional inheritance,
so for now we have to restrict the optimization to partitioned tables.)
Hence, we may skip recursing to child tables in this situation.
The reason this case is worth worrying about is that when pg_dump dumps
a partitioned table having a primary key, it will include the requisite
NOT NULL markings in the CREATE TABLE commands, and then add the
primary key as a separate step. The primary key addition generates a
SET NOT NULL as a subcommand, just to be sure. So the situation where
a SET NOT NULL is redundant does arise in the real world.
Skipping the recursion does more than just save a few cycles: it means
that a command such as "ALTER TABLE ONLY partition_parent ADD PRIMARY
KEY" will take locks only on the partition parent table, not on the
partitions. It turns out that parallel pg_restore is effectively
assuming that that's true, and has little choice but to do so because
the dependencies listed for such a TOC entry don't include the
partitions. pg_restore could thus issue this ALTER while data restores
on the partitions are still in progress. Taking unnecessary locks on
the partitions not only hurts concurrency, but can lead to actual
deadlock failures, as reported by Domagoj Smoljanovic.
(A contributing factor in the deadlock is that TRUNCATE on a child
partition wants a non-exclusive lock on the parent. This seems
likewise unnecessary, but the fix for it is more invasive so we
won't consider back-patching it. Fortunately, getting rid of one
of these two poor behaviors is enough to remove the deadlock.)
Although support for partitioned primary keys came in with v11,
this patch is dependent on the SET NOT NULL refactoring done by
commit f4a3fdfbd, so we can only patch back to v12.
Patch by me; thanks to Alvaro Herrera and Amit Langote for review.
Discussion: https://postgr.es/m/VI1PR03MB31670CA1BD9625C3A8C5DD05EB230@VI1PR03MB3167.eurprd03.prod.outlook.com
ALTER TABLE commands in an extension script are added to an event
trigger command list; but starting with commit b5810de3f4 they do so in
a memory context that's too short-lived, so when execution ends and time
comes to use the entries, they've already been freed.
(This would also be a problem with ALTER TABLE commands in a
multi-command query string, but these serendipitously end in
PortalContext -- which probably explains why it took so long for this to
be reported.)
Fix by using the memory context specifically set for that, instead.
Backpatch to 13, where the aforementioned commit appeared.
Reported-by: Philippe Beaudoin
Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Discussion: https://postgr.es/m/20200902193715.6e0269d4@firost
We were already raising an error for DROP INDEX CONCURRENTLY on a
partitioned table, albeit a different and confusing one:
ERROR: DROP INDEX CONCURRENTLY must be first action in transaction
Change that to throw a more comprehensible error:
ERROR: cannot drop partitioned index \"%s\" concurrently
Michael Paquier authored the test case for indexes on temporary
partitioned tables.
Backpatch to 11, where indexes on partitioned tables were added.
Reported-by: Jan Mussler <jan.mussler@zalando.de>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/16594-d2956ca909585067@postgresql.org
Commit 1281a5c90 rearranged the logic in this area rather drastically,
and it broke the case of adding a foreign key constraint in the same
ALTER that adds the pkey or unique constraint it depends on. While
self-referential fkeys are surely a pretty niche case, this used to
work so we shouldn't break it.
To fix, reorganize the scheduling rules in ATParseTransformCmd so
that a transformed AT_AddConstraint subcommand will be delayed into
a later pass in all cases, not only when it's been spit out as a
side-effect of parsing some other command type.
Also tweak the logic so that we won't run ATParseTransformCmd twice
while doing this. It seems to work even without that, but it's
surely wasting cycles to do so.
Per bug #16589 from Jeremy Evans. Back-patch to v13 where the new
code was introduced.
Discussion: https://postgr.es/m/16589-31c8d981ca503896@postgresql.org
If a CREATE TABLE command uses both LIKE and traditional inheritance,
Vars in CHECK constraints and expression indexes that are absorbed
from a LIKE parent table tended to get mis-numbered, resulting in
wrong answers and/or bizarre error messages (though probably not any
actual crashes, thanks to validation occurring in the executor).
In v12 and up, the same could happen to Vars in GENERATED expressions,
even in cases with no LIKE clause but multiple traditional-inheritance
parents.
The cause of the problem for LIKE is that parse_utilcmd.c supposed
it could renumber such Vars correctly during transformCreateStmt(),
which it cannot since we have not yet accounted for columns added via
inheritance. Fix that by postponing processing of LIKE INCLUDING
CONSTRAINTS, DEFAULTS, GENERATED, INDEXES till after we've performed
DefineRelation().
The error with GENERATED and multiple inheritance is a simple oversight
in MergeAttributes(); it knows it has to renumber Vars in inherited
CHECK constraints, but forgot to apply the same processing to inherited
GENERATED expressions (a/k/a defaults).
Per bug #16272 from Tom Gottfried. The non-GENERATED variants of the
issue are ancient, presumably dating right back to the addition of
CREATE TABLE LIKE; hence back-patch to all supported branches.
Discussion: https://postgr.es/m/16272-6e32da020e9a9381@postgresql.org
Commit ce77abe63c allowed EXPLAIN (BUFFERS) to report the information
on buffer usage during planning phase. However three issues were
reported regarding this feature.
(1) Previously, EXPLAIN option BUFFERS required ANALYZE. So the query
had to be actually executed by specifying ANALYZE even when we
want to see only the planner's buffer usage. This was inconvenient
especially when the query was write one like DELETE.
(2) EXPLAIN included the planner's buffer usage in summary
information. So SUMMARY option had to be enabled to report that.
Also this format was confusing.
(3) The output structure for planning information was not consistent
between TEXT format and the others. For example, "Planning" tag
was output in JSON format, but not in TEXT format.
For (1), this commit allows us to perform EXPLAIN (BUFFERS) without
ANALYZE to report the planner's buffer usage.
For (2), this commit changed EXPLAIN output so that the planner's
buffer usage is reported before summary information.
For (3), this commit made the output structure for planning
information more consistent between the formats.
Back-patch to v13 where the planner's buffer usage was allowed to
be reported in EXPLAIN.
Reported-by: Pierre Giraud, David Rowley
Author: Fujii Masao
Reviewed-by: David Rowley, Julien Rouhaud, Pierre Giraud
Discussion: https://postgr.es/m/07b226e6-fa49-687f-b110-b7c37572f69e@dalibo.com
The SimpleLruTruncate() header comment states the new coding rule. To
achieve this, add locktype "frozenid" and two LWLocks. This closes a
rare opportunity for data loss, which manifested as "apparent
wraparound" or "could not access status of transaction" errors. Data
loss is more likely in pg_multixact, due to released branches' thin
margin between multiStopLimit and multiWrapLimit. If a user's physical
replication primary logged ": apparent wraparound" messages, the user
should rebuild standbys of that primary regardless of symptoms. At less
risk is a cluster having emitted "not accepting commands" errors or
"must be vacuumed" warnings at some point. One can test a cluster for
this data loss by running VACUUM FREEZE in every database. Back-patch
to 9.5 (all supported versions).
Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
Hostile objects located within the installation-time search_path could
capture references in an extension's installation or upgrade script.
If the extension is being installed with superuser privileges, this
opens the door to privilege escalation. While such hazards have existed
all along, their urgency increases with the v13 "trusted extensions"
feature, because that lets a non-superuser control the installation path
for a superuser-privileged script. Therefore, make a number of changes
to make such situations more secure:
* Tweak the construction of the installation-time search_path to ensure
that references to objects in pg_catalog can't be subverted; and
explicitly add pg_temp to the end of the path to prevent attacks using
temporary objects.
* Disable check_function_bodies within installation/upgrade scripts,
so that any security gaps in SQL-language or PL-language function bodies
cannot create a risk of unwanted installation-time code execution.
* Adjust lookup of type input/receive functions and join estimator
functions to complain if there are multiple candidate functions. This
prevents capture of references to functions whose signature is not the
first one checked; and it's arguably more user-friendly anyway.
* Modify various contrib upgrade scripts to ensure that catalog
modification queries are executed with secure search paths. (These
are in-place modifications with no extension version changes, since
it is the update process itself that is at issue, not the end result.)
Extensions that depend on other extensions cannot be made fully secure
by these methods alone; therefore, revert the "trusted" marking that
commit eb67623c9 applied to earthdistance and hstore_plperl, pending
some better solution to that set of issues.
Also add documentation around these issues, to help extension authors
write secure installation scripts.
Patch by me, following an observation by Andres Freund; thanks
to Noah Misch for review.
Security: CVE-2020-14350
9bdb300de modified the EXPLAIN output for Hash Aggregate to show details
from parallel workers. However, it neglected to consider that a given
parallel worker may not have assisted with the given Hash Aggregate. This
can occur when workers fail to start or during Parallel Append with
enable_partitionwise_join enabled when only a single worker is working on
a non-parallel aware sub-plan. It could also happen if a worker simply
wasn't fast enough to get any work done before other processes went and
finished all the work.
The bogus output came from the fact that ExplainOpenWorker() skipped
showing any details for non-initialized workers but show_hashagg_info()
did show details from the worker. This meant that the worker properties
that were shown were not properly attributed to the worker that they
belong to.
In passing, we also now don't show Hash Aggregate properties for the
leader process when it did not contribute any work to the Hash Aggregate.
This can occur either during Parallel Append when only a parallel worker
worked on a given sub plan or with parallel_leader_participation set to
off. This aims to make the behavior of Hash Aggregate's EXPLAIN output
more similar to Sort's.
Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20200805012105.GZ28072%40telsasoft.com
Backpatch-through: 13, where the original breakage was introduced
If a base type supports typmods, its array type does too, with the
same interpretation. Hence changes in pg_type.typmodin/typmodout
must be propagated to the array type.
While here, improve AlterTypeRecurse to not recurse to domains if
there is nothing we'd need to change.
Oversight in fe30e7ebf. Back-patch to v13 where that came in.
There were various unnecessary differences between Hash Agg's EXPLAIN
ANALYZE output and Hash Join's. Here we modify the Hash Agg output so
that it's better aligned to Hash Join's.
The following changes have been made:
1. Start batches counter at 1 instead of 0.
2. Always display the "Batches" property, even when we didn't spill to
disk.
3. Use the text "Batches" instead of "HashAgg Batches" for text format.
4. Use the text "Memory Usage" instead of "Peak Memory Usage" for text
format.
5. Include "Batches" before "Memory Usage" in both text and non-text
formats.
In passing also modify the "Planned Partitions" property so that we show
it regardless of if the value is 0 or not for non-text EXPLAIN formats.
This was pointed out by Justin Pryzby and probably should have been part
of 40efbf870.
Reviewed-by: Justin Pryzby, Jeff Davis
Discussion: https://postgr.es/m/CAApHDvrshRnA6C0VFnu7Fb9TVvgGo80PUMm5+2DiaS1gEkPvtw@mail.gmail.com
Backpatch-through: 13, where HashAgg batching was introduced
An ALTER TABLE to validate a foreign key in which another subcommand
already caused a pending table rewrite could fail due to ALTER TABLE
attempting to validate the foreign key before the actual table rewrite
takes place. This situation could result in an error such as:
ERROR: could not read block 0 in file "base/nnnnn/nnnnn": read only 0 of 8192 bytes
The failure here was due to the SPI call which validates the foreign key
trying to access an index which is yet to be rebuilt.
Similarly, we also incorrectly tried to validate CHECK constraints before
the heap had been rewritten.
The fix for both is to delay constraint validation until phase 3, after
the table has been rewritten. For CHECK constraints this means a slight
behavioral change. Previously ALTER TABLE VALIDATE CONSTRAINT on
inheritance tables would be validated from the bottom up. This was
different from the order of evaluation when a new CHECK constraint was
added. The changes made here aligns the VALIDATE CONSTRAINT evaluation
order for inheritance tables to be the same as ADD CONSTRAINT, which is
generally top-down.
Reported-by: Nazli Ugur Koyluoglu, using SQLancer
Discussion: https://postgr.es/m/CAApHDvp%3DZXv8wiRyk_0rWr00skhGkt8vXDrHJYXRMft3TjkxCA%40mail.gmail.com
Backpatch-through: 9.5 (all supported versions)
The Sort node does not put a space between the number of kilobytes and
the "kB" of memory or disk space used, but HashAgg does. Here we align
HashAgg to do the same as Sort. Sort has been displaying this
information for longer than HashAgg, so it makes sense to align HashAgg
to Sort rather than the other way around.
Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20200708163021.GW4107@telsasoft.com
Backpatch-through: 13, where the hashagg started showing these details
Commit ecd9e9f0b fixed the problem in the wrong place, causing unwanted
side-effects on the behavior of GetNextTempTableSpace(). Instead,
let's make SharedFileSetInit() responsible for subbing in the value
of MyDatabaseTableSpace when the default tablespace is called for.
The convention about what is in the tempTableSpaces[] array is
evidently insufficiently documented, so try to improve that.
It also looks like SharedFileSetInit() is doing the wrong thing in the
case where temp_tablespaces is empty. It was hard-wiring use of the
pg_default tablespace, but it seems like using MyDatabaseTableSpace
is more consistent with what happens for other temp files.
Back-patch the reversion of PrepareTempTablespaces()'s behavior to
9.5, as ecd9e9f0b was. The changes in SharedFileSetInit() go back
to v11 where that was introduced. (Note there is net zero code change
before v11 from these two patch sets, so nothing to release-note.)
Magnus Hagander and Tom Lane
Discussion: https://postgr.es/m/CABUevExg5YEsOvqMxrjoNvb3ApVyH+9jggWGKwTDFyFCVWczGQ@mail.gmail.com
A likely copy/paste error in 98e8b48053 from back in 2004 would
cause temp tablespace to be reset to InvalidOid if temp_tablespaces
was set to the same value as the primary tablespace in the database.
This would cause shared filesets (such as for parallel hash joins)
to ignore them, putting the temporary files in the default tablespace
instead of the configured one. The bug is in the old code, but it
appears to have been exposed only once we had shared filesets.
Reviewed-By: Daniel Gustafsson
Discussion: https://postgr.es/m/CABUevExg5YEsOvqMxrjoNvb3ApVyH+9jggWGKwTDFyFCVWczGQ@mail.gmail.com
Backpatch-through: 9.5
The "Disk Usage" and "HashAgg Batches" properties in the EXPLAIN ANALYZE
output for HashAgg were previously only shown if the number of batches
was greater than 0. Here we change this so that these properties are
always shown for EXPLAIN ANALYZE formats other than "text". The idea here
is that since the HashAgg could have spilled to disk if there had been
more data or groups to aggregate, then it's relevant that we're clear in
the EXPLAIN ANALYZE output when no spilling occurred in this particular
execution of the given plan.
For the "text" EXPLAIN format, we still hide these properties when no
spilling occurs. This EXPLAIN format is designed to be easy for humans
to read. To maintain the readability we have a higher threshold for which
properties we display for this format.
Discussion: https://postgr.es/m/CAApHDvo_dmNozQQTmN-2jGp1vT%3Ddxx7Q0vd%2BMvD1cGpv2HU%3DSg%40mail.gmail.com
Backpatch-through: 13, where the hashagg spilling code was added.
explain_get_index_name() applied quote_identifier() to the index name.
This is fine for text output, but the non-text output formats all have
their own quoting conventions and would much rather start from the
actual index name. For example in JSON you'd get something like
"Index Name": "\"My Index\"",
which is surely not desirable, especially when the same does not
happen for table names. Hence, move the responsibility for applying
quoting out to the callers, where it can go into already-existing
special code paths for text format.
This changes the API spec for users of explain_get_index_name_hook:
before, they were supposed to apply quote_identifier() if necessary,
now they should not. Research suggests that the only publicly
available user of the hook is hypopg, and it actually forgot to
apply quoting anyway, so it's fine. (In any case, there's no
behavioral change for the output of a hook as seen in non-text
EXPLAIN formats, so this won't break any case that programs should
be relying on.)
Digging in the commit logs, it appears that quoting was included in
explain_get_index_name's duties when commit 604ffd280 invented it;
and that was fine at the time because we only had text output format.
This should have been rethought when non-text formats were invented,
but it wasn't.
This is a fairly clear bug for users of non-text EXPLAIN formats,
so back-patch to all supported branches.
Per bug #16502 from Maciek Sakrejda. Patch by me (based on
investigation by Euler Taveira); thanks to Julien Rouhaud for review.
Discussion: https://postgr.es/m/16502-57bd1c9f913ed1d1@postgresql.org
Since 1f39bce02, HashAgg nodes have had the ability to spill to disk when
memory consumption exceeds work_mem. That commit added new properties to
EXPLAIN ANALYZE to show the maximum memory usage and disk usage, however,
it didn't quite go as far as showing that information for parallel
workers. Since workers may have experienced something very different from
the main process, we should show this information per worker, as is done
in Sort.
Reviewed-by: Justin Pryzby
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/CAApHDvpEKbfZa18mM1TD7qV6PG+w97pwCWq5tVD0dX7e11gRJw@mail.gmail.com
Backpatch-through: 13, where the hashagg spilling code was added.
Noah Misch
Tom Lane
Etsuro Fujita
Alvaro Herrera
Tomas Vondra
Michael Paquier
Amit Kapila
Jeff Davis
Andrew Dunstan
Peter Eisentraut
Peter Geoghegan
Heikki Linnakangas
Fujii Masao
David Rowley
Magnus Hagander