The previous text claimed that once the slot is disassociated with
ALTER SUBSCRIPTION ... SET (slot_name = NONE), DROP SUBSCRIPTION "will no
longer attempt any actions on a remote host". That is inaccurate:
DROP SUBSCRIPTION may still connect to the publisher to drop
internally-created table synchronization slots when some table
synchronization is left unfinished. Reword to describe this, and note
that if the publisher is unreachable those slots (and the main slot, if
it still exists) must be dropped manually to avoid indefinitely reserving
WAL.
Reported-by: Jeff Davis <pgsql@j-davis.com>
Author: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 14
Discussion: https://postgr.es/m/CAA4eK1+tyYSpPxMBy1974kjivuGeR7YY=yopwRGrK3+vCTysdg@mail.gmail.com
Discussion: https://postgr.es/m/D908370F-2695-4231-851D-17179A6A6F2A@gmail.com
Commit c7aeb775 rewrote the HOT-chain offset sanity checks in three
places, but in heap_get_root_tuples it accidentally tested offnum -- the
outer loop variable, which is already bounded by the loop condition --
instead of nextoffnum, the offset actually passed to PageGetItemId. The
pre-c7aeb775 check tested nextoffnum.
With the check ineffective, a stale t_ctid could make PageGetItemId read
past the end of the line pointer array (which is data corruption that we
expect to be able to catch here).
Author: Peter Geoghegan <pg@bowt.ie>
Reported-by: Konstantin Knizhnik <knizhnik@garret.ru>
Discussion: https://postgr.es/m/87c7d8a4-3a82-4334-bee6-e8c2ad3f3293@garret.ru
Backpatch-through: 15
Previously, libpqrcv_create_slot() checked only that
CREATE_REPLICATION_SLOT returned PGRES_TUPLES_OK before reading
values from the first row. If the server unexpectedly returned an
invalid result, such as zero rows, PQgetvalue() could return NULL,
leading to a crash while parsing the LSN.
Other replication commands, such as IDENTIFY_SYSTEM, already validate
the response shape before accessing result values, but
CREATE_REPLICATION_SLOT did not.
Fix this by verifying that CREATE_REPLICATION_SLOT response contains
exactly one row with four fields, and report a protocol violation otherwise.
Backpatch to all supported versions.
Bug: #19547
Reported-by: Yuelin Wang <1217816127@qq.com>
Author: Kenny Chen <kennychen851228@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/19547-f7986f668f71e788@postgresql.org
Discussion: https://postgr.es/m/CAPXstDtW2iqe+DJAOTQTX+rRziJp2UhZSo1+HRj1COAtbu+nKw@mail.gmail.com
Backpatch-through: 14
The documentation for log_parameter_max_length said it affects messages
generated by log_duration. However, log_duration alone does not log bind
parameter values, so this is misleading.
This commit updates the documentation to reference log_min_duration_statement,
which can log bind parameters, to better reflect actual behavior.
Backpatch to all supported versions.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Surya Poondla <suryapoondla4@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwGnCVMVz8-LU9F8Sh57bkQX3jMZzx7age7M0LFEz5=Fog@mail.gmail.com
Backpatch-through: 14
Heap WAL records that clear bits on the visibility map (like inserts and
deletes) did not register the visibility map blocks they modified.
Because the WAL summarizer only records registered blocks, an
incremental backup taken over such operations would omit the changed VM
pages. On restore, the VM would retain stale all-visible/all-frozen
bits, which can cause wrong results from index-only scans and incorrect
relfrozenxid advancement due to vacuum page skipping.
Not registering the VM buffer also meant we never emitted FPIs of VM
pages when clearing bits. A torn VM page won't raise an error because
the VM is read with ZERO_ON_ERROR; with checksums on, it would be
detected and zeroed, but with checksums off, it is accepted as-is and
can lead to data corruption.
Fix this by registering the VM buffer in the WAL record when clearing VM
bits. The VM buffer must now be locked throughout the critical section
that modifies the VM and heap pages and emits the WAL record. This can
slow down operations that clear the VM, since the VM lock is held longer
and VM FPIs may be emitted, but it is required for correctness.
Note that this fix does not repair existing incremental backups.
Author: Melanie Plageman <melanieplageman@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/flat/CAAKRu_bn%2Be7F4yPFBgFbnP%2BsyJRKyNK092bjD2LKvZW7O4Svag>
Backpatch-through: 17
When registering a buffer with the WAL machinery, the caller assigns it a
block reference ID, and replay must read each block back by that same ID.
Today these IDs are bare integers assigned by convention (0, 1, 2, ...),
which is easy to follow when a record registers a single block, or when the
blocks are handled during replay in their registration order.
An upcoming bug fix registers up to two visibility map blocks in addition
to the heap block(s) when clearing the VM, and these are not handled during
replay in a straightforward 1:1, in-registration-order fashion. Relying on
bare integers for the block IDs in that case is error-prone.
Introduce macros naming the block reference IDs for the heap record types
that the upcoming commit extends to register visibility map blocks, so the
registration and replay sites refer to the same block by a meaningful name.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/66mqpfyti3qhfttcsv6r2lbvqqd32rrmpn6i47ovrsnvguts46%40gou54xc>
Backpatch through: 17
When bulk-extending a relation, we add the newly-added blocks that we
won't immediately use to the free space map and then call
FreeSpaceMapVacuumRange() to propagate that free space up the FSM tree,
so other backends can find and reuse it.
However, the end block argument to FreeSpaceMapVacuumRange() is
exclusive, and we passed the number of the last added block (since
00d1e02be2). If that block was the first one covered by a new FSM page,
its free space wasn't propagated up the tree and was therefore invisible
to FSM searches until the next FSM vacuum.
Fix by passing the block number one past the last added block, so the
full range is vacuumed.
Author: Jingtang Zhang <mrdrivingduck@gmail.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/flat/CAPsk3_Bx_vdybN%3D-DZu8HLStf%2BXnuFUBkLwxouONSMkWuO9oug%40mail.gmail.com
Backpatch-through: 16
Code elsewhere in the system assumes that fork numbers and chunk sizes
are within bounds, so the code that reads those quantities from disk
should validate that they are. Without these additional checks, a
corrupted file can cause us to index off the end of fork number or chunk
entry arrays, potentially resulting in a crash.
Reported-by: oxsignal <awo@kakao.com> (chunk sizes)
Reported-by: Robert Haas <rhaas@postgresql.org> (fork numbers)
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: http://postgr.es/m/CA+TgmoYP8RKoBGosS7C6Fdr-GNCfyz_W1zmK=Tx1Fe0ZvzGh0g@mail.gmail.com
Backpatch-through: 17
It was possible to trigger read_stream_begin_relation's
assertion that it calculated nonzero max_pinned_buffers,
in scenarios with unreasonably small numbers of buffers.
There seems to be no visible problem in non-Assert builds.
The bug occurs only in v17 (the first branch containing
this logic), because commit 92fc6856c replaced that Assert
with a runtime clamp. I won't risk back-patching that entire
commit, but let's copy just this minimal fix.
Bug: #19551
Reported-by: Roman Zharkov <r.zharkov@postgrespro.ru>
Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19551-d4a55b8fe81db4f2@postgresql.org
Backpatch-through: 17 only
equalPolicy() is used in the relation cache to check if two policy
definitions are equivalent, but missed to check for polpermissive.
ALTER POLICY cannot switch a policy to be PERMISSIVE or RESTRICTIVE, so
this would need a dropped and then re-created policy, which would
trigger a relcache invalidation. Anyway, there is no harm in being
consistent in the check, and if one decides to add an ALTER POLICY to
switch PERMISSIVE or RESTRICTIVE, we would be silently in trouble.
Author: Andreas Lind <andreaslindpetersen@gmail.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://postgr.es/m/CAMxA3rv1CS6R7JR5ojz-3CmCEnZEFrqu+XXTnGbLRWrjJRH7sA@mail.gmail.com
Backpatch-through: 14
The pg_attribute_always_inline macro name is so long it forces pgindent
to format the code in strange ways. Which may incentivize patch authors
to either structure the code in strange ways (e.g. reorder prototypes),
use shorter names, etc. Neither is very desirable for code readability.
This shortens the name by removing the _attribute_ part. It also makes
it more consistent with pg_noinline, which does not have the _attribute_
part either.
Backpatched to all supported branches, to prevent conflicts when
backpatching other fixes. The backbranches however keep both the old and
new macro name, so that existing code keeps working.
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/bqqdehahpoa36igpictuqyn2s2mexk3t3ehidh2ffd2slb35e5@rzgksuiszgbg
Backpatch-through: 14
Check explicitly for pqsecure_read() returning an error. It shouldn't
fail, and we would've caught it in the check for a short read, but
better to be explicit so that the error message is more informative.
We also shouldn't update 'inEnd' when the read fails, although that
too is just pro forma as we will bail out and close the connection on
error.
Reported-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/34844e8c-267c-4daf-b1e0-f26059a4a7d3@eisentraut.org
Backpatch-through: 14
Commit aa606b9316 disallowed generated columns in COPY FROM WHERE
expressions, and commit 21c69dc73f disallowed system columns.
However, the COPY reference page still mentions only the restriction
on subqueries.
Update the documentation to also list generated columns and system
columns as unsupported in COPY FROM WHERE expressions.
Backpatch the generated-column documentation change to all supported
versions. Backpatch the system-column documentation change to v19,
where that restriction was introduced.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwEgxErc54yVOAVWCsr1O=8pgw4oKRPuEQ9mfhkoYGR_XA@mail.gmail.com
Backpatch-through: 14
Commit dcb0049523 accidentally changed the final expanded query's
condition to > 2 while rewriting the example into SQL operator notation.
The original query and the preceding rewritten forms all use >= 2,
and view expansion should preserve that qualification. This commit
changes the final condition from > 2 to >= 2.
Backpatch to all supported versions.
Reported-by: Yaroslav Saburov <y.saburov@gmail.com>
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/178248467618.108999.9966122434342474006@wrigleys.postgresql.org
Backpatch-through: 14
If an expression containing an aggregate is evaluated above the plan
node that computes the aggregate, as happens with window functions or
with expressions postponed to above the final sort, setrefs.c replaces
the Aggref or WindowFunc with a Var referencing the lower node's
output. For SQL/JSON aggregates such as JSON_ARRAYAGG and
JSON_OBJECTAGG, deparsing the containing JsonConstructorExpr then
failed with "invalid JsonConstructorExpr underlying node type", since
get_json_agg_constructor() did not expect a Var there.
Fix by resolving the Var back to the underlying Aggref or WindowFunc
and deparsing the constructor as if the aggregate were computed at the
current node. The JsonConstructorExpr retains the RETURNING clause
and the ABSENT/NULL ON NULL and WITH UNIQUE options, and the arguments
come from the resolved aggregate, so the original JSON aggregate
syntax is reproduced in full. This mirrors how get_agg_expr() already
looks through such a Var when deparsing a combining aggregate.
Reported-by: Thom Brown <thom@linux.com>
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAA-aLv5QYTaMOk=Qhv6cgwceeHETZV8YJvWZ_rH+yVZCuchATA@mail.gmail.com
Backpatch-through: 16
The previous commit strengthened a workaround for a hang when large
messages are split across TLS records/GSS tokens. Because that
workaround is implemented in libpq internals, it can only help us when
libpq itself is polling on the socket. In nonblocking situations,
where the client above libpq is expected to poll, the same bugs can
show up.
As a contrived example, consider a large protocol-2.0 error coming
back from a server during PQconnectPoll(), split in an odd way across
two records:
-- TLS record (8192-byte payload) --
EEEE[...repeated a total of 8192 times]
-- TLS record (8193-byte payload) --
EEEE[...repeated a total of 8192 times]\0
The first record will fill the first half of the libpq receive buffer,
which is 16k long by default. The second record completely fills the
last half with its first 8192 bytes, leaving the terminating NULL in
the OpenSSL buffer. Since we still haven't seen the terminator at our
level, PQconnectPoll() will return PGRES_POLLING_READING, expecting to
come back when the server has sent "the rest" of the data. But there
is nothing left to read from the socket; OpenSSL had to pull all of
the data in the 8193-byte record off of the wire to decrypt it.
A real server would probably not split up the records this way, nor
keep the connection open after sending a fatal connection error. But
servers that regularly use larger TLS records can get the libpq
receive buffer into the same state if DataRows are big enough, as
reported on the list. While the PostgreSQL server doesn't use larger
TLS records like that, other non-PostgreSQL servers that implement the
wire protocol are known to do that, as well as proxies that sit
between the server and the client
This is a layering violation. libpq makes decisions based on data in
the application buffer, above the transport buffer (whether SSL or
GSS), but clients are polling the socket below the transport buffer.
One way to fix this in a backportable way, without changing APIs too
much, is to ensure data never stays in the transport buffer. Then
pqReadData's postconditions will look similar for both raw sockets and
SSL/GSS: any available data is either in the application buffer, or
still on the socket.
Building on the prior commit, make pqReadData() to drain all pending
data from the transport layer into conn->inBuffer, expanding the
buffer as necessary. This is not particularly efficient from an
architectural perspective (the pqsecure_read() implementations take
care to fit their packets into the current buffer, and that effort is
now completely discarded), but it's hopefully easier to reason about
than a full rewrite would be for the back branches.
Author: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Mark Dilger <mark.dilger@enterprisedb.com>
Reviewed-by: solai v <solai.cdac@gmail.com>
Reported-by: Lars Kanis <lars@greiz-reinsdorf.de>
Discussion: https://postgr.es/m/2039ac58-d3e0-434b-ac1a-2a987f3b4cb1%40greiz-reinsdorf.de
Backpatch-through: 14
An extra check for pending bytes in the SSL layer has been part of
pqReadReady() for a very long time (79ff2e96d). But when GSS transport
encryption was added, it didn't receive the same treatment. (As
79ff2e96d notes, "The bug that I fixed in this patch is exceptionally
hard to reproduce reliably.")
Without that check, it's possible to hit a hang in gssencmode, if the
server splits a large libpq message such that the final message in a
streamed response is part of the same wrapped token as the split
message:
DataRowDataRowDataRowDataRowDataRowData
-- token boundary --
RowDataRowCommandCompleteReadyForQuery
If the split message takes up enough memory to nearly fill libpq's
receive buffer, libpq may return from pqReadData() before the later
messages are pulled out of the PqGSSRecvBuffer. Without additional
socket activity from the server, pqReadReady() (via pqSocketCheck())
will never again return true, hanging the connection.
Pull the pending-bytes check into the pqsecure API layer, where both
SSL and GSS now implement it.
Note that this does not fix the root problem! Third party clients of
libpq have no way to call pqsecure_read_is_pending() in their own
polling. This just brings the GSS implementation up to par with the
existing SSL workaround; a broader fix is left to a subsequent commit.
In preparation for the broader fix, this patch already changes the
*_read_pending() functions to return the number of bytes in the buffer
rather than just a boolean. The current callers don't need that, but
the subsequent fix will.
Author: Jacob Champion <jacob.champion@enterprisedb.com>
Discussion: https://postgr.es/m/CAOYmi%2BmpymrgZ76Jre2dx_PwRniS9YZojwH0rZnTuiGHCsj0rA%40mail.gmail.com
Backpatch-through: 14
ParallelBackupStart() stored _beginthreadex()'s return value as the
worker's thread handle without checking it. On failure that value is 0,
which would later reach WaitForMultipleObjects() as a null handle, caught
only by an Assert. The fork() path already calls pg_fatal() when it
fails; do the same for _beginthreadex(), as pgbench does.
Author: Bryan Green <dbryan.green@gmail.com>
Discussion: https://www.postgresql.org/message-id/8c712d76-ecf7-4749-a6d8-dddc01f298ec@gmail.com
Backpatch-through: 14
9d9c02ccd added code to allow the executor to stop early when processing
WindowAgg nodes where a monotonic window function starts producing
values that result in a pushed-down qual no longer matching, and will
never match again due to the window function's monotonic properties.
That commit requires a SupportRequestWFuncMonotonic to exist on the
window function and for it to detect when the function is monotonic. For
COUNT(ANY) and COUNT(*), the support function failed to consider some
cases where the WindowClause used EXCLUDE to exclude certain rows from
being aggregated. Some WindowClause definitions mean we aggregate rows
that come after the current row, and when processing those rows later,
if we EXCLUDE certain rows, the monotonic property can be broken.
Wrongly treating the COUNT(*) or COUNT(ANY) aggregate as monotonic could
lead to rows being filtered that should not be filtered from the result
set.
Another issue was that the support function for the COUNT aggregate
mistakenly thought that a WindowClause without an ORDER BY meant that
the results would be both monotonically increasing and decreasing, but
that's only true when in RANGE mode, where all rows are peers.
It is possible to support various cases that do have an EXCLUDE clause,
but getting the logic correct for the exact set of cases that are valid
is quite complex and would likely better be left for a future project.
Here, we mostly disable run condition pushdown when there is an EXCLUDE
clause unless the clause is for EXCLUDE CURRENT ROW, uses COUNT(*)
(rather than COUNT(ANY)), and the window aggregate has no FILTER clause.
Bug: #19533
Reported-by: Qifan Liu <imchifan@163.com>
Author: Chengpeng Yan <chengpeng_yan@outlook.com>
Author: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Discussion: https://postgr.es/m/19533-413a1014e5d0e766@postgresql.org
Backpatch-through: 15
transformJsonBehavior() coerced an ON EMPTY / ON ERROR DEFAULT
expression only when its type differed from the RETURNING type's OID.
When the base type matched but the RETURNING type carried a type
modifier (e.g. numeric(4,1) or varchar(3)), the coercion that enforces
the typmod was skipped, so the DEFAULT value could violate the
declared type:
SELECT JSON_VALUE(jsonb '{}', '$.a'
RETURNING numeric(4,1) DEFAULT 99999.999 ON EMPTY);
returned 99999.999, which 99999.999::numeric(4,1) would reject; the
value could even be stored into a numeric(4,1) column, as later
coercions trust its already-correct type label.
Fix by also coercing when the RETURNING type has a typmod, except for
a NULL constant. coerce_to_target_type() is a no-op when the typmod
already matches. The matching-OID short-circuit dates to 74c96699be.
Reported-by: Ewan Young <kdbase.hack@gmail.com>
Author: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/CAON2xHPO9f4cAmyGn1mQ=VqoS7wN5rz4yOiqudxX78zninZpCw@mail.gmail.com
Backpatch-through: 17
Commit e7564ee8cd, which fixed base backup progress reporting on
backup failure, removed the external function basebackup_progress_done()
because it was no longer used in core. When that change was backpatched
to v15, it introduced an ABI break, which was reported by buildfarm
member crake.
This commit restores basebackup_progress_done() to preserve ABI
compatibility, even though it is no longer used in core, rather than
updating the .abi-compliance-history file. Because external backup
tools may still call this function.
Per buildfarm member crake.
Reported-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/CAD5tBcJ+ktrEp=PT8Gq-f=8mA2cDtZMB-hDMV4mMJ+9V46qBeQ@mail.gmail.com
Backpatch-through: 15-18
ON SELECT rules must be named "_RETURN", while other kinds of rules
must not be; this ancient restriction is depended on by various client
code. We successfully enforced this convention in most places, but
ALTER RULE allowed renaming a non-SELECT rule to "_RETURN". Notably,
that would break dump/restore, since the eventual CREATE RULE command
would reject the name.
While at it, remove DefineQueryRewrite's hack to substitute "_RETURN"
for the convention that was used before 7.3. We dropped other
server-side code that supported restoring pre-7.3 dumps some time ago
(notably in e58a59975 and nearby commits), but this bit was missed.
Bug: #19543
Reported-by: Adam Pickering <adamkpickering@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19543-461228e77f3b32fc@postgresql.org
Backpatch-through: 14
gbt_var_consistent() handled the <> (BtreeGistNotEqual) strategy without
distinguishing leaf from internal pages, unlike every other strategy.
In particular, it tried to apply the datatype-specific f_eq method,
which is completely wrong since internal keys might not have the same
representation as leaf keys. This led to OOB reads and potentially
crashes, and most likely to wrong query results as well.
On leaf pages we can apply the inverse of what the Equal strategy does.
On internal pages, use a correct implementation of what the previous
code intended: we can descend if the query value equals both bounds,
*so long as the bounds aren't truncated*. With truncated bounds we
don't quite know the range of what's below, so we must always descend.
Adjust the code in gbt_num_consistent() to look similar, too. This
fixes a performance buglet in that there's no need to do two comparisons
on a leaf entry, but the main point is just to keep code consistency.
Reported-by: 王跃林 <violin0613@tju.edu.cn>
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/AH*AvQCYKhQGVvPWi1GiU4oY.8.1781609375063.Hmail.3020001251@tju.edu.cn
Backpatch-through: 14
Commit ce146621 ensures that ERROR is raised if a session tries to read
pages of another session's temp table. But there is a corner case where
the other session's temp table is empty -- in this case the INSERT
command bypasses our checks and executes without any errors.
Such behavior is inconsistent and erroneous: it leaves an invalid buffer
in the temp buffers pool. Since the buffer was created for another
session's temp table, we get an error "no such file or directory" when
trying to flush it.
This commit fixes it by adding a RELATION_IS_OTHER_TEMP check in the
relation-extension path.
Backpatch to 16, because it is the first release after 31966b151e, which
introduced a separate local relation extension function
ExtendBufferedRelLocal(), which lacks of RELATION_IS_OTHER_TEMP() check.
As this fix introduces more checks to 013_temp_obj_multisession.pl, backpatch
the whole test script to 16.
Discussion: https://postgr.es/m/CAJDiXgiX2XZBHDNo%2BzBbvku%2BtchrUurvPRaN1_40mEQ1_sG90g%40mail.gmail.com
Author: Daniil Davydov <3danissimo@gmail.com>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Reviewed-by: Imran Zaheer <imran.zhir@gmail.com>
Reviewed-by: ZizhuanLiu X-MAN <44973863@qq.com>
Backpatch-through: 16
Previously, MultiXactId wraparound hints suggested dropping stale
replication slots. While that advice is appropriate for transaction ID
wraparound, where replication slots can hold back XID horizons,
it was misleading for MultiXactId wraparound. Following it could lead
users to drop replication slots unnecessarily without helping resolve
the MultiXactId wraparound condition.
MultiXact cleanup is not directly delayed by replication slots.
Instead, it depends on whether old MultiXactIds can still be seen
as live by running transactions.
This commit removes the replication slot advice from MultiXactId
wraparound hints, and documents that stale replication slots are
normally not relevant to resolving MultiXactId wraparound problems.
Backpatch to all supported branches.
BUG #18876
Reported-by: Haruka Takatsuka <harukat@sraoss.co.jp>
Author: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/18876-0d0b53bad5a1f4c1@postgresql.org
Backpatch-through: 14
The jsonpath .decimal(precision[, scale]) method built its numeric
typmod by calling numerictypmodin() through DirectFunctionCall1(), which
can throw a hard error for an incorrect set of precision and/or scale
vaulues. This breaks the silent mode supported by this function, that
should not fail.
Most of the jsonpath code uses the soft error reporting to bypass
errors, which is what this fix does by avoiding a direct use of
numerictypmodin(). Its code is refactored to use a new routine called
make_numeric_typmod_safe(), able to take an error context in input.
numerictypmodin() sets no context, mapping to its previous behavior.
The jsonpath code sets or not a context depending on the use of the
silent mode. This result leads to some nice simplifications:
numerictypmodin() feeds on an array, we can now pass directly values for
the scale and precision.
Oversight in 66ea94e8e6.
Author: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/CAON2xHMaigKABiyPBBq3Sjd3gp7uWMJXnnMHt=s85V1ij3KP1w@mail.gmail.com
Backpatch-through: 17
The float4 and float8 btree_gist opclasses compared keys with raw C
operators (==, <, >). IEEE 754 makes every comparison involving NaN
false, so GiST disagreed with the regular float comparison operators
and with the btree opclass, which uses float[4|8]_cmp_internal()
(so that all NaNs are equal and NaN sorts after every non-NaN value).
In addition, the penalty and distance functions were not careful
about NaNs, and the penalty functions could also misbehave for IEEE
infinities. Wrong answers from the penalty functions would probably
do no more than make the index non-optimal, but the distance mistakes
were visible from SQL.
To fix, make the comparison functions rely on the same NaN-aware
comparison functions the core code uses, and rewrite the penalty
and distance functions to follow the rules that NaNs are equal
but maximally far away from non-NaNs. The penalty_num() code was
formerly shared between integral and float cases, but I chose to make
two copies so that the integral cases are not saddled with the extra
logic for NaNs and infinities/overflows. I also rewrote it as static
inline functions instead of an unreadable and uncommented macro.
The float penalty functions were previously unreached by the
regression tests, so add new test cases to exercise them.
There's no on-disk format change, but users who have NaN entries
in a btree_gist index would be well advised to reindex it.
Bug: #19501
Bug: #19524
Reported-by: Man Zeng <zengman@halodbtech.com>
Reported-by: Yuelin Wang <3020001251@tju.edu.cn>
Author: Bill Kim <billkimjh@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19501-3bff3bbc97f1e7c9@postgresql.org
Discussion: https://postgr.es/m/19524-9559d302c8455664@postgresql.org
Discussion: https://postgr.es/m/CAMQXxcgbtD2LXfX0tpgvOizxP-XxrCHV2ZDy4By_TZnJMsxXWQ@mail.gmail.com
Backpatch-through: 14
Previously, if a base backup failed after it had started streaming
files, pg_stat_progress_basebackup could continue to show a stale
progress entry even though the backup was no longer running. This could
be observed when the client kept the replication connection open after
the error. It is normally not observable when using pg_basebackup,
because the client disconnects after the error.
The problem was that progress reporting was cleared only after
successful completion.
This commit moves the progress reporting cleanup into the progress
sink's cleanup callback so that it is cleared after both successful
and failed backups.
Backpatch to v15. v14 has the same issue, but the fix does not apply
cleanly because it lacks the base backup sink infrastructure. Since
the bug does not affect the backup itself and is normally not
observable when using pg_basebackup, skip the v14 backpatch.
Author: Chao Li <lic@highgo.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/EA1A6CD2-EFA6-462B-9A02-03003555AB4A@gmail.com
Backpatch-through: 15
off_t is most likely a 64-bit integer, so casting it to a 32-bit type
for output could lose data. There are more issues like this in the
tree, but this is an instance where this could actually happen in
practice, since base backups are routinely larger than 4 GB. So this
is separated out as a bug fix.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/20ce62fa-47fc-457b-b504-12f3c1651726%40eisentraut.org
Commit 4035cd5d4 added LZ4 compression for full-page writes in WAL, and
retained "on" as a backward-compatible way to specify the builtin PGLZ
method. Document this meaning of "on" and update postgresql.conf.sample
to make the equivalence clear.
Author: Christoph Berg <myon@debian.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/akJDHRtXwGLTppsQ@msg.df7cb.de
Backpatch-through: 15
Previously, if an unlogged sequence was created on the primary and
replicated to a standby, reading the sequence after promoting the
standby (for example, with nextval()) could trigger the following
assertion failure:
TRAP: failed Assert("((const PageHeaderData *) page)->pd_special >= SizeOfPageHeaderData")
In non-assert builds, the same operation could instead fail with an
error such as:
ERROR: bad magic number in sequence
The problem was that seq_redo() updated the init fork page in shared
buffers but did not flush it to disk. During promotion,
ResetUnloggedRelations() recreates the main fork of unlogged
relations by copying the init fork from disk, bypassing shared
buffers. As a result, the main fork could be recreated from a stale
init fork instead of the WAL-replayed page.
Fix this by introducing a helper to flush init fork buffers
immediately, and make seq_redo() use it. As a result, the main fork
of an unlogged sequence is recreated from the up-to-date init fork on
disk, allowing the unlogged sequence to be read successfully after
standby promotion.
Backpatch to v15, where unlogged sequences were introduced.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwH1Ssze3XM6wjoTjSLVOR041c6xP+vsdLP951=w8oG8bA@mail.gmail.com
Backpatch-through: 15
PL/Python and its hstore and jsonb transforms build SQL values from
Python containers by calling Python C API functions that can return
NULL, and in several places the result was used without first checking
it.
On the sequence side, PySequence_GetItem() is used when converting a
returned sequence into a SQL array or composite value, when reading
the argument list passed to plpy.execute() or plpy.cursor(), and when
reading the list of type names given to plpy.prepare(). On the
mapping side, the hstore and jsonb transforms call PyMapping_Size()
and PyMapping_Items() and then index the result with PyList_GetItem()
and PyTuple_GetItem().
All of these return NULL (or -1), with a Python exception set, for a
broken object: for example one whose __getitem__() or items() raises,
or which reports a length that disagrees with what it actually yields.
The unchecked result was then dereferenced, crashing the backend.
Fix this by checking the result of each call and reporting a regular
error if it failed, so that the underlying Python exception is
surfaced instead of taking down the session.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49BKM9wP6m8bCXEpHwQKp7usvOGV6Jf=J7FYr_BCpxLqg@mail.gmail.com
Backpatch-through: 14
In get_perl_array_ref(), for a PostgreSQL::InServer::ARRAY object, we
look up its "array" key with hv_fetch_string() and then inspect the
returned SV. However, hv_fetch_string() returns a NULL pointer when
the key is absent, and the code dereferenced that result without first
checking whether the pointer itself was NULL. As a result, a plperl
function returning a forged PostgreSQL::InServer::ARRAY object that
lacks the "array" key would crash the backend with a segmentation
fault.
Fix this by checking the pointer returned by hv_fetch_string() before
dereferencing it, matching how other callers in this file already
guard the result. With the check in place, such an object falls
through to the existing error report instead of crashing.
Author: Xing Guo <higuoxing@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CACpMh+DYgcnqZwQLXXuxQcehJTd7T8UmKWSLsK4mFBEp9G2ajA@mail.gmail.com
Backpatch-through: 14
This routine acts as a wrapper of a new pgstat_drop_entry_ext(), used in
the core code with a missing_ok argument.
This includes an update of .abi-compliance-history, removing the latest
entry that has documented the change of pgstat_drop_entry(). This
change is applied across v15~v18. HEAD keeps pgstat_drop_entry() as
single entry point, with the new missing_ok.
Per discussion with Álvaro Herrera and Lukas Fittl. This is a follow-up
of 850b9218c8.
Discussion: https://postgr.es/m/ajZz_sVJVX7pmPHo@alvherre.pgsql
Backpatch-through: 15-18
This function called the resource-kind-specific ReleaseResource()
method for each item before deleting that item from the resowner.
That's backwards from the ordering in ResourceOwnerReleaseAllOfKind,
and it's not very safe. If ReleaseResource throws an error then the
subsequent abort cleanup will come back here and try to release that
item again, possibly leading to a double-free or similar crash,
and in any case risking an infinite error cleanup loop. This mistake
explains why the pgcrypto bug just fixed in 80bb0ebcc led to a crash
rather than something more benign.
Remove the item from the resowner, then call ReleaseResource,
matching the way things were done before b8bff07da. If there
is a problem of this sort, we'd prefer to leak the item than
suffer the other likely consequences.
Per further analysis of bug #19527.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/646741.1782157515@sss.pgh.pa.us
Backpatch-through: 17
Raising an error within a function using an OSSLCipher object led
to a complaint from ResourceOwnerForget and then a double-free crash,
because ResOwnerReleaseOSSLCipher forgot to unhook the OSSLCipher
object from its owner. (The sibling logic for OSSLDigest objects got
this right, as did every other ReleaseResource function AFAICS.)
Oversight in cd694f60d.
Bug: #19527
Reported-by: Yuelin Wang <3020001251@tju.edu.cn>
Author: Yuelin Wang <3020001251@tju.edu.cn>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19527-6e7686960c6dce78@postgresql.org
Backpatch-through: 17
pg_mkdir_p creates each missing path component with a stat() followed
by mkdir(). If the stat() reports the component as absent but another
process creates it in the window before this process's mkdir(), mkdir()
fails with EEXIST and pg_mkdir_p treated that as a hard error -- unlike
"mkdir -p", which is meant to be idempotent and race-tolerant.
This shows up when several processes concurrently create paths that
share an ancestor directory: for example, parallel initdb runs whose
data directories live under a common temporary directory. One process
wins the race to create the shared ancestor and the others fail with
could not create directory "...": File exists
Fix this race condition by first trying mkdir() and only attempting
stat() if it fails with EEXIST.
On Windows, there's an additional problem: stat() opens a file handle
and participates in share-mode locking, which means it can transiently
fail on a directory another process is concurrently creating. Use
GetFileAttributes() instead: it requests only FILE_READ_ATTRIBUTES
and is exempt from share-mode denial, so it reliably sees a
concurrently-created directory.
I (tgl) also chose to back-patch 039f7ee0f's effects on this function,
so that pgmkdirp.c remains identical in all live branches.
Author: Andrew Dunstan <andrew@dunslane.net>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/3ca004de-e49b-4471-b8aa-fd656e70f68c@dunslane.net
Backpatch-through: 14
Add CHECK_FOR_INTERRUPTS() to the while loop in plperl_to_hstore()
that dereferences chains of Perl references, so that a circular
reference (e.g. $x = \$x) can be cancelled by the user instead of
spinning indefinitely. (We looked at detecting such circular
references, but it seems more trouble than it's worth.)
This is a follow-up to da82fbb8f, which fixed the same issue in
SV_to_JsonbValue() in jsonb_plperl.
Author: Aleksander Alekseev <aleksander@tigerdata.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAJ7c6TPbjkzUk4qJ5dHvDNEz0hBuFue3A-XWz_=897z+BC+z8A@mail.gmail.com
Backpatch-through: 14
Commit 6678b58d78 fixed a wrong "Prev" link by changing the link
generation code to use [position()=last()] instead of [last()] in
the predicate on the union of reverse axes. Unfortunately, that
caused documentation builds to take much longer. To fix, combine
the "preceding" and "ancestor" steps into one "preceding" step and
one "ancestor" step, and revert the predicate back to [last()].
The smaller union evades the libxml2 bug while avoiding the build
time regression.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Tested-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1132496.1781718007%40sss.pgh.pa.us
Backpatch-through: 14
