end_heap_rewrite was not careful to ensure that the target relation
is open at the smgr level before performing its final smgrimmedsync.
In ordinary cases this is no problem, because it would have been
opened earlier during the rewrite. However a crash can be reproduced
by re-clustering an empty table with CLOBBER_CACHE_ALWAYS enabled.
Although that exact scenario does not crash in v13, I think that's
a chance result of unrelated planner changes, and the problem is
likely still reachable with other test cases. The true proximate
cause of this failure is commit c6b92041d, which replaced a call to
heap_sync (which was careful about opening smgr) with a direct call
to smgrimmedsync. Hence, back-patch to v13.
Amul Sul, per report from Neha Sharma; cosmetic changes
and test case by me.
Discussion: https://postgr.es/m/CANiYTQsU7yMFpQYnv=BrcRVqK_3U3mtAzAsJCaqtzsDHfsUbdQ@mail.gmail.com
The test added by 595b9cb forgot that on Windows it is necessary to set
up pg_hba.conf (see PostgresNode::set_replication_conf) with a specific
entry or base backups fail. Any node that requires to support
replication just needs to pass down allows_streaming at initialization.
This updates the test to do so. Simplify things a bit while on it.
Per buildfarm member fairywren. Any Windows hosts running this test
would have failed, and I have reproduced the problem as well.
Backpatch-through: 10
Any transactions found as still prepared by a checkpoint have their
state data read from the WAL records generated by PREPARE TRANSACTION
before being moved into their new location within pg_twophase/. While
reading such records, the WAL reader uses the callback
read_local_xlog_page() to read a page, that is shared across various
parts of the system. This callback, since 1148e22a, has introduced an
update of ThisTimeLineID when reading a record while in recovery, which
is potentially helpful in the context of cascading WAL senders.
This update of ThisTimeLineID interacts badly with the checkpointer if a
promotion happens while some 2PC data is read from its record, as, by
changing ThisTimeLineID, any follow-up WAL records would be written to
an timeline older than the promoted one. This results in consistency
issues. For instance, a subsequent server restart would cause a failure
in finding a valid checkpoint record, resulting in a PANIC, for
instance.
This commit changes the code reading the 2PC data to reset the timeline
once the 2PC record has been read, to prevent messing up with the static
state of the checkpointer. It would be tempting to do the same thing
directly in read_local_xlog_page(). However, based on the discussion
that has led to 1148e22a, users may rely on the updates of
ThisTimeLineID when a WAL record page is read in recovery, so changing
this callback could break some cases that are working currently.
A TAP test reproducing the issue is added, relying on a PITR to
precisely trigger a promotion with a prepared transaction still
tracked.
Per discussion with Heikki Linnakangas, Kyotaro Horiguchi, Fujii Masao
and myself.
Author: Soumyadeep Chakraborty, Jimmy Yih, Kevin Yeap
Discussion: https://postgr.es/m/CAE-ML+_EjH_fzfq1F3RJ1=XaaNG=-Jz-i3JqkNhXiLAsM3z-Ew@mail.gmail.com
Backpatch-through: 10
GENERATED ALWAYS AS IDENTITY implies NOT NULL, but the code failed
to complain if you overrode that with "GENERATED ALWAYS AS IDENTITY
NULL". One might think the old behavior was a feature, but it was
inconsistent because the outcome varied depending on the order of
the clauses, so it seems to have been just an oversight.
Per bug #16913 from Pavel Boev. Back-patch to v10 where identity
columns were introduced.
Vik Fearing (minor tweaks by me)
Discussion: https://postgr.es/m/16913-3b5198410f67d8c6@postgresql.org
Remove the entire idea of "stale stats" within nbtree VACUUM (stop
caring about stats involving the number of inserted tuples). Also
remove the vacuum_cleanup_index_scale_factor GUC/param on the master
branch (though just disable them on postgres 13).
The vacuum_cleanup_index_scale_factor/stats interface made the nbtree AM
partially responsible for deciding when pg_class.reltuples stats needed
to be updated. This seems contrary to the spirit of the index AM API,
though -- it is not actually necessary for an index AM's bulk delete and
cleanup callbacks to provide accurate stats when it happens to be
inconvenient. The core code owns that. (Index AMs have the authority
to perform or not perform certain kinds of deferred cleanup based on
their own considerations, such as page deletion and recycling, but that
has little to do with pg_class.reltuples/num_index_tuples.)
This issue was fairly harmless until the introduction of the
autovacuum_vacuum_insert_threshold feature by commit b07642db, which had
an undesirable interaction with the vacuum_cleanup_index_scale_factor
mechanism: it made insert-driven autovacuums perform full index scans,
even though there is no real benefit to doing so. This has been tied to
a regression with an append-only insert benchmark [1].
Also have remaining cases that perform a full scan of an index during a
cleanup-only nbtree VACUUM indicate that the final tuple count is only
an estimate. This prevents vacuumlazy.c from setting the index's
pg_class.reltuples in those cases (it will now only update pg_class when
vacuumlazy.c had TIDs for nbtree to bulk delete). This arguably fixes
an oversight in deduplication-related bugfix commit 48e12913.
[1] https://smalldatum.blogspot.com/2021/01/insert-benchmark-postgres-is-still.html
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAD21AoA4WHthN5uU6+WScZ7+J_RcEjmcuH94qcoUPuB42ShXzg@mail.gmail.com
Backpatch: 13-, where autovacuum_vacuum_insert_threshold was added.
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
makeDependencyGraphWalker and checkWellFormedRecursionWalker
thought they could hold onto a pointer to a list's first
cons cell while the list was modified by recursive calls.
That was okay when the cons cell was actually separately
palloc'd ... but since commit 1cff1b95a, it's quite unsafe,
leading to core dumps or incorrect complaints of faulty
WITH nesting.
In the field this'd require at least a seven-deep WITH nest
to cause an issue, but enabling DEBUG_LIST_MEMORY_USAGE
allows the bug to be seen with lesser nesting depths.
Per bug #16801 from Alexander Lakhin. Back-patch to v13.
Michael Paquier and Tom Lane
Discussion: https://postgr.es/m/16801-393c7922143eaa4d@postgresql.org
This commit fixes COMMIT AND CHAIN command so that it starts new transaction
immediately even if savepoints are defined within the transaction to commit.
Previously COMMIT AND CHAIN command did not in that case because
commit 280a408b48 forgot to make CommitTransactionCommand() handle
a transaction chaining when the transaction state was TBLOCK_SUBCOMMIT.
Also this commit adds the regression test for COMMIT AND CHAIN command
when savepoints are defined.
Back-patch to v12 where transaction chaining was added.
Reported-by: Arthur Nascimento
Author: Fujii Masao
Reviewed-by: Arthur Nascimento, Vik Fearing
Discussion: https://postgr.es/m/16867-3475744069228158@postgresql.org
Commit 2c8dd05d6c added the atomic variable writtenUpto into
walreceiver's shared memory information. It's initialized only
when walreceiver started up but could be read via pg_stat_wal_receiver
view anytime, i.e., even before it's initialized. In the server built
with --disable-atomics and --disable-spinlocks, this uninitialized
atomic variable read could cause "invalid spinlock number: 0" error.
This commit changed writtenUpto so that it's initialized at
the postmaster startup, to avoid the uninitialized variable read
via pg_stat_wal_receiver and fix the error.
Also this commit moved the read of writtenUpto after the release
of spinlock protecting walreceiver's shared variables. This is
necessary to prevent new spinlock from being taken by atomic
variable read while holding another spinlock, and to shorten
the spinlock duration. This change leads writtenUpto not to be
consistent with the other walreceiver's shared variables protected
by a spinlock. But this is OK because writtenUpto should not be
used for data integrity checks.
Back-patch to v13 where commit 2c8dd05d6c introduced the bug.
Author: Fujii Masao
Reviewed-by: Michael Paquier, Thomas Munro, Andres Freund
Discussion: https://postgr.es/m/7ef8708c-5b6b-edd3-2cf2-7783f1c7c175@oss.nttdata.com
The inner loop in switchToPresortedPrefixMode() can be implemented
as a conventional integer-counter for() loop, removing a couple of
redundant boolean state variables. The old logic here was a remnant
of earlier development, but as things now stand there's no reason
for extra complexity.
Also, annotate the test case added by 82e0e2930 to explain why it
manages to hit the corner case fixed in that commit, and add an
EXPLAIN to verify that it's creating an incremental-sort plan.
Back-patch to v13, like the previous patch.
James Coleman and Tom Lane
Discussion: https://postgr.es/m/16846-ae49f51ac379a4cb@postgresql.org
For an index, attstattarget can be updated using ALTER INDEX SET
STATISTICS. This data was lost on the new index after REINDEX
CONCURRENTLY.
The update of this field is done when the old and new indexes are
swapped to make the fix back-patchable. Another approach we could look
after in the long-term is to change index_create() to pass the wanted
values of attstattarget when creating the new relation, but, as this
would cause an ABI breakage this can be done only on HEAD.
Reported-by: Ronan Dunklau
Author: Michael Paquier
Reviewed-by: Ronan Dunklau, Tomas Vondra
Discussion: https://postgr.es/m/16628084.uLZWGnKmhe@laptop-ronand
Backpatch-through: 12
scanNSItemForColumn, expandNSItemAttrs, and ExpandSingleTable would
pass the wrong RTE to markVarForSelectPriv when dealing with a join
ParseNamespaceItem: they'd pass the join RTE, when what we need to
mark is the base table that the join column came from. The end
result was to not fill the base table's selectedCols bitmap correctly,
resulting in an understatement of the set of columns that are read
by the query. The executor would still insist on there being at
least one selectable column; but with a correctly crafted query,
a user having SELECT privilege on just one column of a table would
nonetheless be allowed to read all its columns.
To fix, make markRTEForSelectPriv fetch the correct RTE for itself,
ignoring the possibly-mismatched RTE passed by the caller. Later,
we'll get rid of some now-unused RTE arguments, but that risks
API breaks so we won't do it in released branches.
This problem was introduced by commit 9ce77d75c, so back-patch
to v13 where that came in. Thanks to Sven Klemm for reporting
the problem.
Security: CVE-2021-20229
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
rewriteRuleAction() neglected this step, although it was careful to
propagate other similar flags such as hasSubLinks or hasRowSecurity.
Omitting to transfer hasRecursive is just cosmetic at the moment,
but omitting hasModifyingCTE is a live bug, since the executor
certainly looks at that.
The proposed test case only fails back to v10, but since the executor
examines hasModifyingCTE in 9.x as well, I suspect that a test case
could be devised that fails in older branches. Given the nearness
of the release deadline, though, I'm not going to spend time looking
for a better test.
Report and patch by Greg Nancarrow, cosmetic changes by me
Discussion: https://postgr.es/m/CAJcOf-fAdj=nDKMsRhQzndm-O13NY4dL6xGcEvdX5Xvbbi0V7g@mail.gmail.com
Generally, members of inheritance trees must be plain tables (or,
in more recent versions, foreign tables). ALTER TABLE INHERIT
rejects creating an inheritance relationship that has a view at
either end. When DefineQueryRewrite attempts to convert a relation
to a view, it already had checks prohibiting doing so for partitioning
parents or children as well as traditional-inheritance parents ...
but it neglected to check that a traditional-inheritance child wasn't
being converted. Since the planner assumes that any inheritance
child is a table, this led to making plans that tried to do a physical
scan on a view, causing failures (or even crashes, in recent versions).
One could imagine trying to support such a case by expanding the view
normally, but since the rewriter runs before the planner does
inheritance expansion, it would take some very fundamental refactoring
to make that possible. There are probably a lot of other parts of the
system that don't cope well with such a situation, too. For now,
just forbid it.
Per bug #16856 from Yang Lin. Back-patch to all supported branches.
(In versions before v10, this includes back-patching the portion of
commit 501ed02cf that added has_superclass(). Perhaps the lack of
that infrastructure partially explains the missing check.)
Discussion: https://postgr.es/m/16856-0363e05c6e1612fd@postgresql.org
switchToPresortedPrefixMode() did the wrong thing if it detected
a batch boundary just at the last tuple of a fullsort group.
The initially-reported symptom was a "retrieved too many tuples in a
bounded sort" error, but the test case added here just silently gives
the wrong answer without this patch.
I (tgl) am not really happy about committing this patch without review
from the incremental-sort authors, but they seem AWOL and we are hard
against a release deadline. This does demonstrably make some cases
better, anyway.
Per bug #16846 from Yoran Heling. Back-patch to v13 where incremental
sort was introduced.
Neil Chen
Discussion: https://postgr.es/m/16846-ae49f51ac379a4cb@postgresql.org
CREATE PUBLICATION has failed spuriously when applied to a permanent
relation created or rewritten in the current transaction. Make the same
change to another site having the same semantic intent; the second
instance has no user-visible consequences. Back-patch to v13, where
commit c6b92041d3 broke this.
Kyotaro Horiguchi
Discussion: https://postgr.es/m/20210113.160705.2225256954956139776.horikyota.ntt@gmail.com
In a cluster having used CREATE INDEX CONCURRENTLY while having enabled
prepared transactions, queries that use the resulting index can silently
fail to find rows. Fix this for future CREATE INDEX CONCURRENTLY by
making it wait for prepared transactions like it waits for ordinary
transactions. This expands the VirtualTransactionId structure domain to
admit prepared transactions. It may be necessary to reindex to recover
from past occurrences. Back-patch to 9.5 (all supported versions).
Andrey Borodin, reviewed (in earlier versions) by Tom Lane and Michael
Paquier.
Discussion: https://postgr.es/m/2E712143-97F7-4890-B470-4A35142ABC82@yandex-team.ru
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
perform_pruning_combine_step() was not taught about the number of
partition indexes used in hash partitioning; more embarrassingly,
get_matching_hash_bounds() also had it wrong. These errors are masked
in the common case where all the partitions have the same modulus
and no partition is missing. However, with missing or unequal-size
partitions, we could erroneously prune some partitions that need
to be scanned, leading to silently wrong query answers.
While a minimal-footprint fix for this could be to export
get_partition_bound_num_indexes and make the incorrect functions use it,
I'm of the opinion that that function should never have existed in the
first place. It's not reasonable data structure design that
PartitionBoundInfoData lacks any explicit record of the length of
its indexes[] array. Perhaps that was all right when it could always
be assumed equal to ndatums, but something should have been done about
it as soon as that stopped being true. Putting in an explicit
"nindexes" field makes both partition_bounds_equal() and
partition_bounds_copy() simpler, safer, and faster than before,
and removes explicit knowledge of the number-of-partition-indexes
rules from some other places too.
This change also makes get_hash_partition_greatest_modulus obsolete.
I left that in place in case any external code uses it, but no core
code does anymore.
Per bug #16840 from Michał Albrycht. Back-patch to v11 where the
hash partitioning code came in. (In the back branches, add the new
field at the end of PartitionBoundInfoData to minimize ABI risks.)
Discussion: https://postgr.es/m/16840-571a22976f829ad4@postgresql.org
Previously, pull_varnos() took the relids of a PlaceHolderVar as being
equal to the relids in its contents, but that fails to account for the
possibility that we have to postpone evaluation of the PHV due to outer
joins. This could result in a malformed plan. The known cases end up
triggering the "failed to assign all NestLoopParams to plan nodes"
sanity check in createplan.c, but other symptoms may be possible.
The right value to use is the join level we actually intend to evaluate
the PHV at. We can get that from the ph_eval_at field of the associated
PlaceHolderInfo. However, there are some places that call pull_varnos()
before the PlaceHolderInfos have been created; in that case, fall back
to the conservative assumption that the PHV will be evaluated at its
syntactic level. (In principle this might result in missing some legal
optimization, but I'm not aware of any cases where it's an issue in
practice.) Things are also a bit ticklish for calls occurring during
deconstruct_jointree(), but AFAICS the ph_eval_at fields should have
reached their final values by the time we need them.
The main problem in making this work is that pull_varnos() has no
way to get at the PlaceHolderInfos. We can fix that easily, if a
bit tediously, in HEAD by passing it the planner "root" pointer.
In the back branches that'd cause an unacceptable API/ABI break for
extensions, so leave the existing entry points alone and add new ones
with the additional parameter. (If an old entry point is called and
encounters a PHV, it'll fall back to using the syntactic level,
again possibly missing some valid optimization.)
Back-patch to v12. The computation is surely also wrong before that,
but it appears that we cannot reach a bad plan thanks to join order
restrictions imposed on the subquery that the PlaceHolderVar came from.
The error only became reachable when commit 4be058fe9 allowed trivial
subqueries to be collapsed out completely, eliminating their join order
restrictions.
Per report from Stephan Springl.
Discussion: https://postgr.es/m/171041.1610849523@sss.pgh.pa.us
Specifying duplicated objects in this command would lead to unique
constraint violations in pg_default_acl or "tuple already updated by
self" errors. Similarly to GRANT/REVOKE, increment the command ID after
each subcommand processing to allow this case to work transparently.
A regression test is added by tweaking one of the existing queries of
privileges.sql to stress this case.
Reported-by: Andrus
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/ae2a7dc1-9d71-8cba-3bb9-e4cb7eb1f44e@hot.ee
Backpatch-through: 9.5
The context is an object that no longer bears some aclitem that it bore
initially. (A user issued REVOKE or GRANT statements upon the object.)
pg_dump is forming SQL to reproduce the object ACL. Since initdb
creates no ACL bearing GRANT OPTION, reaching this bug requires an
extension where the creation script establishes such an ACL. No PGXN
extension does that. If an installation did reach the bug, pg_dump
would have omitted a semicolon, causing a REVOKE and the next SQL
statement to fail. Separately, since the affected code exists to
eliminate an entire aclitem, it wants plain REVOKE, not REVOKE GRANT
OPTION FOR. Back-patch to 9.6, where commit
23f34fa4ba first appeared.
Discussion: https://postgr.es/m/20210109102423.GA160022@rfd.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 fef5b47f6b added the regression test to check whether a standby is
able to follow a primary on a newer timeline when WAL archiving is enabled.
But the buildfarm member florican reported that this test failed because
the requested WAL segment was removed and replication failed. This is a
timing issue. Since neither replication slot is used nor wal_keep_size is set
in the test, checkpoint could remove the WAL segment that's still necessary
for replication.
This commit stabilizes the test by setting wal_keep_size.
Back-patch to v13 where the regression test that this commit stabilizes
was added.
Author: Fujii Masao
Discussion: https://postgr.es/m/X//PsenxcC50jDzX@paquier.xyz
Commit 709d003fbd refactored WAL-reading code, but accidentally caused
WalSndSegmentOpen() to fail to follow a timeline switch while reading from
a historic timeline. This issue caused a standby to fail to follow a primary
on a newer timeline when WAL archiving is enabled.
If there is a timeline switch within the segment, WalSndSegmentOpen() should
read from the WAL segment belonging to the new timeline. But previously
since it failed to follow a timeline switch, it tried to read the WAL segment
with old timeline. When WAL archiving is enabled, that WAL segment with
old timeline doesn't exist because it's renamed to .partial. This leads
a primary to have tried to read non-existent WAL segment, and which caused
replication to faill with the error "ERROR: requested WAL segment ... has
already been removed".
This commit fixes WalSndSegmentOpen() so that it's able to follow a timeline
switch, to ensure that a standby is able to follow a primary on a newer
timeline even when WAL archiving is enabled.
This commit also adds the regression test to check whether a standby is
able to follow a primary on a newer timeline when WAL archiving is enabled.
Back-patch to v13 where the bug was introduced.
Reported-by: Kyotaro Horiguchi
Author: Kyotaro Horiguchi, tweaked by Fujii Masao
Reviewed-by: Alvaro Herrera, Fujii Masao
Discussion: https://postgr.es/m/20201209.174314.282492377848029776.horikyota.ntt@gmail.com
In power_var_int(), the computation of the number of significant
digits to use in the computation used log(Abs(exp)), which isn't safe
because Abs(exp) returns INT_MIN when exp is INT_MIN. Use fabs()
instead of Abs(), so that the exponent is cast to a double before the
absolute value is taken.
Back-patch to 9.6, where this was introduced (by 7d9a4737c2).
Discussion: https://postgr.es/m/CAEZATCVd6pMkz=BrZEgBKyqqJrt2xghr=fNc8+Z=5xC6cgWrWA@mail.gmail.com
If the substring start index and length overflow when added together,
substring() misbehaved, either throwing a bogus "negative substring
length" error on a case that should succeed, or failing to complain that
a negative length is negative (and instead returning the whole string,
in most cases). Unsurprisingly, the text, bytea, and bit variants of
the function all had this issue. Rearrange the logic to ensure that
negative lengths are always rejected, and add an overflow check to
handle the other case.
Also install similar guards into detoast_attr_slice() (nee
heap_tuple_untoast_attr_slice()), since it's far from clear that
no other code paths leading to that function could pass it values
that would overflow.
Patch by myself and Pavel Stehule, per bug #16804 from Rafi Shamim.
Back-patch to v11. While these bugs are old, the common/int.h
infrastructure for overflow-detecting arithmetic didn't exist before
commit 4d6ad3125, and it doesn't seem like these misbehaviors are bad
enough to justify developing a standalone fix for the older branches.
Discussion: https://postgr.es/m/16804-f4eeeb6c11ba71d4@postgresql.org
Removing the EXPLAIN test to stabilize the buildfarm. The execution
test should still be effective to catch the bug even if the plan is
slightly different on different platforms.
Before processing tuples, agg_refill_hash_table() was setting all
pergroup pointers to NULL to signal to advance_aggregates() that it
should not attempt to advance groups that had spilled.
The problem was that it also set the pergroups for sorted grouping
sets to NULL, which caused rescanning to fail.
Instead, change agg_refill_hash_table() to only set the pergroups for
hashed grouping sets to NULL; and when compiling the expression, pass
doSort=false.
Reported-by: Alexander Lakhin
Discussion: https://postgr.es/m/16784-7ff169bf2c3d1588%40postgresql.org
Backpatch-through: 13
This makes existing sessions reflect "ALTER ROLE ... [NO]INHERIT" as
quickly as they have been reflecting "GRANT role_name". Back-patch to
9.5 (all supported versions).
Reviewed by Nathan Bossart.
Discussion: https://postgr.es/m/20201221095028.GB3777719@rfd.leadboat.com
The parsing of this parameter has been using strtoul(), which is not
portable across platforms. On most Unix platforms, unsigned long has a
size of 64 bits, while on Windows it is 32 bits. It is common in
recovery scenarios to rely on the output of txid_current() or even the
newer pg_current_xact_id() to get a transaction ID for setting up
recovery_target_xid. The value returned by those functions includes the
epoch in the computed result, which would cause strtoul() to fail where
unsigned long has a size of 32 bits once the epoch is incremented.
WAL records and 2PC data include only information about 32-bit XIDs and
it is not possible to have XIDs across more than one epoch, so
discarding the high bits from the transaction ID set has no impact on
recovery. On the contrary, the use of strtoul() prevents a consistent
behavior across platforms depending on the size of unsigned long.
This commit changes the parsing of recovery_target_xid to use
pg_strtouint64() instead, available down to 9.6. There is one TAP test
stressing recovery with recovery_target_xid, where a tweak based on
pg_reset{xlog,wal} is added to bump the XID epoch so as this change gets
tested, as per an idea from Alexander Lakhin.
Reported-by: Alexander Lakhin
Discussion: https://postgr.es/m/16780-107fd0c0385b1035@postgresql.org
Backpatch-through: 9.6
While we do allow SRFs in ORDER BY, scan/join processing should not
consider such cases - such sorts should only happen via final Sort atop
a ProjectSet. So make sure we don't try adding such sorts below Gather
Merge, just like we do for expressions that are volatile and/or not
parallel safe.
Backpatch to PostgreSQL 13, where this code was introduced as part of
the Incremental Sort patch.
Author: James Coleman
Reviewed-by: Tomas Vondra
Backpatch-through: 13
Discussion: https://postgr.es/m/CAAaqYe8cK3g5CfLC4w7bs=hC0mSksZC=H5M8LSchj5e5OxpTAg@mail.gmail.com
Discussion: https://postgr.es/m/295524.1606246314%40sss.pgh.pa.us
The jsonb || jsonb operator arbitrarily rejected certain combinations
of scalar and non-scalar inputs, while being willing to concatenate
other combinations. This was of course quite undocumented. Rather
than trying to document it, let's just remove the restriction,
creating a uniform rule that unless we are handling an object-to-object
concatenation, non-array inputs are converted to one-element arrays,
resulting in an array-to-array concatenation. (This does not change
the behavior for any case that didn't throw an error before.)
Per complaint from Joel Jacobson. Back-patch to all supported branches.
Discussion: https://postgr.es/m/163099.1608312033@sss.pgh.pa.us
Commit ebb7ae839d ensured we ignore pathkeys with volatile expressions
when considering adding a sort below a Gather Merge. Turns out we need
to care about parallel safety of the pathkeys too, otherwise we might
try sorting e.g. on results of a correlated subquery (as demonstrated
by a report from Luis Roberto).
Initial investigation by Tom Lane, patch by James Coleman. Backpatch
to 13, where the code was instroduced (as part of Incremental Sort).
Reported-by: Luis Roberto
Author: James Coleman
Reviewed-by: Tomas Vondra
Backpatch-through: 13
Discussion: https://postgr.es/m/622580997.37108180.1604080457319.JavaMail.zimbra%40siscobra.com.br
Discussion: https://postgr.es/m/CAAaqYe8cK3g5CfLC4w7bs=hC0mSksZC=H5M8LSchj5e5OxpTAg@mail.gmail.com
generate_useful_gather_paths used to skip unsorted paths (without any
pathkeys), but that is unnecessary - the later code actually can handle
such paths just fine by adding a Sort node. This is clearly a thinko,
preventing construction of useful plans.
Backpatch to 13, where Incremental Sort was introduced.
Author: James Coleman
Reviewed-by: Tomas Vondra
Backpatch-through: 13
Discussion: https://postgr.es/m/CAAaqYe8cK3g5CfLC4w7bs=hC0mSksZC=H5M8LSchj5e5OxpTAg@mail.gmail.com
Commit 4be058fe9 forgot that the append_rel_list would already be
populated at the time we remove useless result RTEs, and it might contain
PlaceHolderVars that need to be adjusted like the ones in the main parse
tree. This could lead to "no relation entry for relid N" failures later
on, when the planner tries to do something with an unadjusted PHV.
Per report from Tom Ellis. Back-patch to v12 where the bug came in.
Discussion: https://postgr.es/m/20201205173056.GF30712@cloudinit-builder
As it stood, expandTableLikeClause() re-did the same relation_openrv
call that transformTableLikeClause() had done. However there are
scenarios where this would not find the same table as expected.
We hold lock on the LIKE source table, so it can't be renamed or
dropped, but another table could appear before it in the search path.
This explains the odd behavior reported in bug #16758 when cloning a
table as a temp table of the same name. This case worked as expected
before commit 502898192 introduced the need to open the source table
twice, so we should fix it.
To make really sure we get the same table, let's re-open it by OID not
name. That requires adding an OID field to struct TableLikeClause,
which is a little nervous-making from an ABI standpoint, but as long
as it's at the end I don't think there's any serious risk.
Per bug #16758 from Marc Boeren. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/16758-840e84a6cfab276d@postgresql.org
If a PlaceHolderVar is to be evaluated at a join relation, but
its value is only needed there and not at higher levels, we neglected
to update the joinrel's direct_lateral_relids to include the PHV's
source rel. This causes problems because join_is_legal() then won't
allow joining the joinrel to the PHV's source rel at all, leading
to "failed to build any N-way joins" planner failures.
Per report from Andreas Seltenreich. Back-patch to 9.5
where the problem originated.
Discussion: https://postgr.es/m/87blfgqa4t.fsf@aurora.ydns.eu
Commit 502898192 was too careless about the order of execution of the
additional ALTER TABLE operations generated by expandTableLikeClause.
It just stuck them all at the end, which seems okay for most purposes.
But it falls down in the case where LIKE is importing a primary key
or unique index and the outer CREATE TABLE includes a FOREIGN KEY
constraint that needs to depend on that index. Weird as that is,
it used to work, so we ought to keep it working.
To fix, make parse_utilcmd.c insert LIKE clauses between index-creation
and FK-creation commands in the transformed list of commands, and change
utility.c so that the commands generated by expandTableLikeClause are
executed immediately not at the end. One could imagine scenarios where
this wouldn't work either; but currently expandTableLikeClause only
makes column default expressions, CHECK constraints, and indexes, and
this ordering seems fine for those.
Per bug #16730 from Sofoklis Papasofokli. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/16730-b902f7e6e0276b30@postgresql.org
Since this function is used as a CHECK constraint condition,
returning NULL is tantamount to returning TRUE, which would have the
effect of letting in a row that doesn't satisfy the hash condition.
Admittedly, the cases for which this is done should be unreachable
in practice, but that doesn't make it any less a bad idea. It also
seems like a dartboard was used to decide which error cases should
throw errors as opposed to returning NULL.
For the checks for NULL input values, I just switched it to returning
false. There's some argument that an error would be better; but the
case really should be can't-happen in a generated hash constraint,
so it's likely not worth more code for.
For the parent-relation-open-failure case, it seems like we might
as well let relation_open throw an error, instead of having an
impossible-to-diagnose constraint failure.
Back-patch to v11 where this code came in.
Discussion: https://postgr.es/m/24067.1605134819@sss.pgh.pa.us
Summarily changing the STYPE of regression-test aggregates that
depend on array_append or array_cat is an issue for the buildfarm's
cross-version-upgrade tests, because those aggregates (as defined
in the back branches) now won't load into HEAD. Although this seems
like only a minimal risk for genuine user-defined aggregates, we
need to do something for the buildfarm. Hence, adjust the aggregate
definitions, in both HEAD and the back branches.
Discussion: https://postgr.es/m/1401824.1604537031@sss.pgh.pa.us
Discussion: https://postgr.es/m/E1kaQ2c-0005lx-Eg@gemulon.postgresql.org
If an interactive psql session used \gset when querying a compromised
server, the attacker could execute arbitrary code as the operating
system account running psql. Using a prefix not found among specially
treated variables, e.g. every lowercase string, precluded the attack.
Fix by issuing a warning and setting no variable for the column in
question. Users wanting the old behavior can use a prefix and then a
meta-command like "\set HISTSIZE :prefix_HISTSIZE". Back-patch to 9.5
(all supported versions).
Reviewed by Robert Haas. Reported by Nick Cleaton.
Security: CVE-2020-25696
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
