Trying to alter a constraint so that it becomes NOT VALID results in an
error that assumes the constraint is a foreign key. This is potentially
wrong, so give a more generic error message.
While at it, give CREATE CONSTRAINT TRIGGER a better error message as
well.
Co-authored-by: jian he <jian.universality@gmail.com>
Co-authored-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Co-authored-by: Álvaro Herrera <alvherre@kurilemu.de>
Co-authored-by: Amul Sul <sulamul@gmail.com>
Discussion: https://postgr.es/m/CACJufxHSp2puxP=q8ZtUGL1F+heapnzqFBZy5ZNGUjUgwjBqTQ@mail.gmail.com
Recent nbtree bugfix commit 5f4d98d4 added a special case to the code
that sets up a page-level prefix of keys that are definitely satisfied
by every tuple on the page: whenever _bt_set_startikey reached a row
compare key, we'd refuse to apply the pstate.forcenonrequired behavior
in scans where that usually happens (scans with a higher-order array
key). That hack made the scan avoid essentially the same infinite
cycling behavior that also affected nbtree scans with redundant keys
(keys that preprocessing could not eliminate) prior to commit f09816a0.
There are now serious doubts about this row compare workaround.
Testing has shown that a scan with a row compare key and an array key
could still read the same leaf page twice (without the scan's direction
changing), which isn't supposed to be possible following the SAOP
enhancements added by Postgres 17 commit 5bf748b8. Also, we still
allowed a required row compare key to be used with forcenonrequired mode
when its header key happened to be beyond the pstate.ikey set by
_bt_set_startikey, which was complicated and brittle.
The underlying problem was that row compares had inconsistent rules
around how scans start (which keys can be used for initial positioning
purposes) and how scans end (which keys can set continuescan=false).
Quals with redundant keys that could not be eliminated by preprocessing
also had that same quality to them prior to today's bugfix f09816a0. It
now seems prudent to bring row compare keys in line with the new charter
for required keys, by making the start and end rules symmetric.
This commit fixes two points of disagreement between _bt_first and
_bt_check_rowcompare. Firstly, _bt_check_rowcompare was capable of
ending the scan at the point where it needed to compare an ISNULL-marked
row compare member that came immediately after a required row compare
member. _bt_first now has symmetric handling for NULL row compares.
Secondly, _bt_first had its own ideas about which keys were safe to use
for initial positioning purposes. It could use fewer or more keys than
_bt_check_rowcompare. _bt_first now uses the same requiredness markings
as _bt_check_rowcompare for this.
Now that _bt_first and _bt_check_rowcompare agree on how to start and
end scans, we can get rid of the forcenonrequired special case, without
any risk of infinite cycling. This approach also makes row compare keys
behave more like regular scalar keys, particularly within _bt_first.
Fixing these inconsistencies necessitates dealing with a related issue
with the way that row compares were marked required by preprocessing: we
didn't mark any lower-order row members required following 2016 bugfix
commit a298a1e0. That approach was over broad. The bug in question was
actually an oversight in how _bt_check_rowcompare dealt with tuple NULL
values that failed to satisfy a scan key marked required in the opposite
scan direction (it was a bug in 2011 commits 6980f817 and 882368e8, not
a bug in 2006 commit 3a0a16cb). Go back to marking row compare members
as required using the original 2006 rules, and fix the 2016 bug in a
more principled way: by limiting use of the "set continuescan=false with
a key required in the opposite scan direction upon encountering a NULL
tuple value" optimization to the first/most significant row member key.
While it isn't safe to use an implied IS NOT NULL qualifier to end the
scan when it comes from a required lower-order row compare member key,
it _is_ generally safe for such a required member key to end the scan --
provided the key is marked required in the _current_ scan direction.
This fixes what was arguably an oversight in either commit 5f4d98d4 or
commit 8a510275. It is a direct follow-up to today's commit f09816a0.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Discussion: https://postgr.es/m/CAH2-Wz=pcijHL_mA0_TJ5LiTB28QpQ0cGtT-ccFV=KzuunNDDQ@mail.gmail.com
Backpatch-through: 18
nbtree preprocessing's handling of redundant (and contradictory) keys
created problems for scans with = arrays. It was just about possible
for a scan with an = array key and one or more redundant keys (keys that
preprocessing could not eliminate due an incomplete opfamily and a
cross-type key) to get stuck. Testing has shown that infinite cycling
where the scan never manages to make forward progress was possible.
This could happen when the scan's arrays were reset in _bt_readpage's
forcenonrequired=true path (added by bugfix commit 5f4d98d4) when the
arrays weren't at least advanced up to the same point that they were in
at the start of the _bt_readpage call. Earlier redundant keys prevented
the finaltup call to _bt_advance_array_keys from reaching lower-order
keys that needed to be used to sufficiently advance the scan's arrays.
To fix, make preprocessing leave the scan's keys in a state that is as
close as possible to how it'll usually leave them (in the common case
where there's no redundant keys that preprocessing failed to eliminate).
Now nbtree preprocessing _reliably_ leaves behind at most one required
>/>= key per index column, and at most one required </<= key per index
column. Columns that have one or more = keys that are eligible to be
marked required (based on the traditional rules) prioritize the = keys
over redundant inequality keys; they'll _reliably_ be left with only one
of the = keys as the index column's only required key.
Keys that are not marked required (whether due to the new preprocessing
step running or for some other reason) are relocated to the end of the
so->keyData[] array as needed. That way they'll always be evaluated
after the scan's required keys, and so cannot prevent code in places
like _bt_advance_array_keys and _bt_first from reaching a required key.
Also teach _bt_first to decide which initial positioning keys to use
based on the same requiredness markings that have long been used by
_bt_checkkeys/_bt_advance_array_keys. This is a necessary condition for
reliably avoiding infinite cycling. _bt_advance_array_keys expects to
be able to reason about what'll happen in the next _bt_first call should
it start another primitive index scan, by evaluating inequality keys
that were marked required in the opposite-to-scan scan direction only.
Now everybody (_bt_first, _bt_checkkeys, and _bt_advance_array_keys)
will always agree on which exact key will be used on each index column
to start and/or end the scan (except when row compare keys are involved,
which have similar problems not addressed by this commit).
An upcoming commit will finish off the work started by this commit by
harmonizing how _bt_first, _bt_checkkeys, and _bt_advance_array_keys
apply row compare keys to start and end scans.
This fixes what was arguably an oversight in either commit 5f4d98d4 or
commit 8a510275.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Discussion: https://postgr.es/m/CAH2-Wz=ds4M+3NXMgwxYxqU8MULaLf696_v5g=9WNmWL2=Uo2A@mail.gmail.com
Backpatch-through: 18
Commit c120550edb optimized the vacuuming of relations without
indexes (a.k.a. one-pass strategy) by directly marking dead item IDs
as LP_UNUSED. However, the periodic FSM vacuum was still checking if
dead item IDs had been marked as LP_DEAD when attempting to vacuum the
FSM every VACUUM_FSM_EVERY_PAGES blocks. This condition was never met
due to the optimization, resulting in missed FSM vacuum
opportunities.
This commit modifies the periodic FSM vacuum condition to use the
number of tuples deleted during HOT pruning. This count includes items
marked as either LP_UNUSED or LP_REDIRECT, both of which are expected
to result in new free space to report.
Back-patch to v17 where the vacuum optimization for tables with no
indexes was introduced.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CAD21AoBL8m6B9GSzQfYxVaEgvD7-Kr3AJaS-hJPHC+avm-29zw@mail.gmail.com
Backpatch-through: 17
When decompressing some input data, the calculation for the initial
starting point and the initial size were incorrect, potentially leading
to failures when decompressing contents with LZ4. These initialization
points are fixed in this commit, bringing the logic closer to what
exists for gzip and zstd.
The contents of the compressed data is clear (for example backups taken
with LZ4 can still be decompressed with a "lz4" command), only the
decompression part reading the input data was impacted by this issue.
This code path impacts pg_basebackup and pg_verifybackup, which can use
the LZ4 decompression routines with an archive streamer, or any tools
that try to use the archive streamers in src/fe_utils/.
The issue is easier to reproduce with files that have a low-compression
rate, like ones filled with random data, for a size of at least 512kB,
but this could happen with anything as long as it is stored in a data
folder. Some tests are added based on this idea, with a file filled
with random bytes grabbed from the backend, written at the root of the
data folder. This is proving good enough to reproduce the original
problem.
Author: Mikhail Gribkov <youzhick@gmail.com>
Discussion: https://postgr.es/m/CAMEv5_uQS1Hg6KCaEP2JkrTBbZ-nXQhxomWrhYQvbdzR-zy-wA@mail.gmail.com
Backpatch-through: 15
We stopped defining IOV_MAX on non-Windows systems in 75357ab94, on
the assumption that every non-Windows system defines it in <limits.h>
as required by X/Open. GNU Hurd, however, doesn't follow that
standard either. Put back the old logic to assume 16 if it's
not defined.
Author: Michael Banck <mbanck@gmx.net>
Co-authored-by: Christoph Berg <myon@debian.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/6862e8d1.050a0220.194b8d.76fa@mx.google.com
Discussion: https://postgr.es/m/6846e0c3.df0a0220.39ef9b.c60e@mx.google.com
Backpatch-through: 16
The existing code assumed that O_RDONLY is defined as 0, but this is
not required by POSIX and is not true on GNU Hurd. We can avoid
the assumption by relying on O_ACCMODE to mask the fcntl() result.
(Hopefully, all supported platforms define that.)
Author: Michael Banck <mbanck@gmx.net>
Co-authored-by: Samuel Thibault
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/6862e8d1.050a0220.194b8d.76fa@mx.google.com
Discussion: https://postgr.es/m/68480868.5d0a0220.1e214d.68a6@mx.google.com
Backpatch-through: 13
Querying the NUMA status can be quite time consuming, especially with
large shared buffers. 8cc139bec3 called numa_move_pages() once, for
all buffers, and we had to wait for the syscall to complete.
But with the chunking, introduced by 7fe2f67c7c to work around a kernel
bug, we can do CHECK_FOR_INTERRUPTS() after each chunk, allowing users
to abort the execution.
Reviewed-by: Christoph Berg <myon@debian.org>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aEtDozLmtZddARdB@msg.df7cb.de
Backpatch-through: 18
When querying NUMA status of pages in shared memory, we need to touch
the memory first to get valid results. This may trigger valgrind
reports, because some of the memory (e.g. unpinned buffers) may be
marked as noaccess.
Solved by adding a valgrind suppresion. An alternative would be to
adjust the access/noaccess status before touching the memory, but that
seems far too invasive. It would require all those places to have
detailed knowledge of what the shared memory stores.
The pg_numa_touch_mem_if_required() macro is replaced with a function.
Macros are invisible to suppressions, so it'd have to suppress reports
for the caller - e.g. pg_get_shmem_allocations_numa(). So we'd suppress
reports for the whole function, and that seems to heavy-handed. It might
easily hide other valid issues.
Reviewed-by: Christoph Berg <myon@debian.org>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aEtDozLmtZddARdB@msg.df7cb.de
Backpatch-through: 18
There's a kernel bug in do_pages_stat(), affecting systems combining
64-bit kernel and 32-bit user space. The function splits the request
into chunks of 16 pointers, but forgets the pointers are 32-bit when
advancing to the next chunk. Some of the pointers get skipped, and
memory after the array is interpreted as pointers. The result is that
the produced status of memory pages is mostly bogus.
Systems combining 64-bit and 32-bit environments like this might seem
rare, but that's not the case - all 32-bit Debian packages are built in
a 32-bit chroot on a system with a 64-bit kernel.
This is a long-standing kernel bug (since 2010), affecting pretty much
all kernels, so it'll take time until all systems get a fixed kernel.
Luckily, we can work around the issue by chunking the requests the same
way do_pages_stat() does, at least on affected systems. We don't know
what kernel a 32-bit build will run on, so all 32-bit builds use chunks
of 16 elements (the largest chunk before hitting the issue).
64-bit builds are not affected by this issue, and so could work without
the chunking. But chunking has other advantages, so we apply chunking
even for 64-bit builds, with chunks of 1024 elements.
Reported-by: Christoph Berg <myon@debian.org>
Author: Christoph Berg <myon@debian.org>
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aEtDozLmtZddARdB@msg.df7cb.de
Context: https://marc.info/?l=linux-mm&m=175077821909222&w=2
Backpatch-through: 18
Per the checklist in RELEASE_CHANGES for the creation of a new stable
branch, this commit does the following things:
- Arm gen_node_support.pl's nodetag ABI stability, based on the contents
of nodetags.h.
- Update URLs of top-level README and Makefile to point to the new
stable version.
Run renumber_oids.pl to move high-numbered OIDs down, as per pre-beta
tasks specified by RELEASE_CHANGES. For reference, the command was
./renumber_oids.pl --first-mapped-oid 8000 --target-oid 6300
This should have been done prior to beta1, but it was forgotten. This
will ensure we get the correct numbering for beta2 onward.
This is required before the creation of a new branch. pgindent is
clean, as well as is reformat-dat-files.
perltidy version is v20230309, as documented in pgindent's README.
In the wake of commit a16ef313f, we need to deal with more cases
involving PlaceHolderVars in NestLoopParams than we did before.
For one thing, a16ef313f was incorrect to suppose that we could
rely on the required-outer relids of the lefthand path to decide
placement of nestloop-parameter PHVs. As Richard Guo argued at
the time, we must look at the required-outer relids of the join
path itself.
For another, we have to apply replace_nestloop_params() to such
a PHV's expression, in case it contains references to values that
will be supplied from NestLoopParams of higher-level nestloops.
For another, we need to be more careful about the phnullingrels
of the PHV than we were being. identify_current_nestloop_params
only bothered to ensure that the phnullingrels didn't contain
"too many" relids, but now it has to be exact, because setrefs.c
will apply both NRM_SUBSET and NRM_SUPERSET checks in different
places. We can compute the correct relids by determining the
set of outer joins that should be able to null the PHV and then
subtracting whatever's been applied at or below this join.
Do the same for plain Vars, too. (This should make it possible
to use NRM_EQUAL to process nestloop params in setrefs.c, but
I won't risk making such a change in v18 now.)
Lastly, if a nestloop parameter PHV was pulled up out of a subquery
and it contains a subquery that was originally pushed down from this
query level, then that will still be represented as a SubLink, because
SS_process_sublinks won't recurse into outer PHVs, so it didn't get
transformed during expression preprocessing in the subquery. We can
substitute the version of the PHV's expression appearing in its
PlaceHolderInfo to ensure that that preprocessing has happened.
(Seems like this processing sequence could stand to be redesigned,
but again, late in v18 development is not the time for that.)
It's not very clear to me why the old have_dangerous_phv join-order
restriction prevented us from seeing the last three of these problems.
But given the lack of field complaints, it must have done so.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18953-1c9883a9d4afeb30@postgresql.org
Sometimes a table's constraint may depend on a column of another
table, so that we have to update the constraint when changing the
referenced column's type. We need to have lock on the constraint's
table to do that. ATPostAlterTypeCleanup believed that this case
was only possible for FOREIGN KEY constraints, but it's wrong at
least for CHECK and EXCLUDE constraints; and in general, we'd
probably need exclusive lock to alter any sort of constraint.
So just remove the contype check and acquire lock for any other
table. This prevents a "you don't have lock" assertion failure,
though no ill effect is observed in production builds.
We'll error out later anyway because we don't presently support
physically altering column types within stored composite columns.
But the catalog-munging is basically all there, so we may as well
make that part work.
Bug: #18970
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Diagnosed-by: jian he <jian.universality@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18970-a7d1cfe1f8d5d8d9@postgresql.org
Backpatch-through: 13
This commit renames the pg_recvlogical options --two-phase and
--failover to --enable-two-phase and --enable-failover, respectively.
The new names distinguish these enabling options from action options
like --start and --create-slot, while clearly indicating their purpose
to enable specific logical slot features.
The option --failover is new in PostgreSQL 18 (commit cf2655a902), so
no compatibility break there. The option --two-phase has existed
since PostgreSQL 15 (commit cda03cfed6), so for compatibility we keep
the old option name --two-phase around as deprecated.
Also note that pg_createsubscriber has acquired an --enable-two-phase
option, so this increases consistency across tools.
Co-authored-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/a28f66df-1354-4709-8d63-932ded4cac35@eisentraut.org
ca307d5cec made CheckPointReplicationSlots() unconditionally call
ReplicationSlotsComputeRequiredLSN(). It causes an assertion trap when
max_replication_slots equals 0. This commit makes
CheckPointReplicationSlots() call ReplicationSlotsComputeRequiredLSN() only
when at least one slot gets its last_saved_restart_lsn updated. That avoids
an assert trap and also saves some cycles when no one slot has
last_saved_restart_lsn updated.
Based on ideas from Dilip Kumar <dilipbalaut@gmail.com> and
Hayato Kuroda <kuroda.hayato@fujitsu.com>.
Reported-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Discussion: https://postgr.es/m/OS0PR01MB5716BB506AF934376FF3A8BB947BA%40OS0PR01MB5716.jpnprd01.prod.outlook.com
Commit 7d6d2c4bbd dropped opcintype from the index AM strategy
translation API. But some error messages about failed lookups still
mentioned it, even though it was not used for the lookup. Fix by
removing ipcintype from the error messages as well.
8e03eb92e9 reverted the commit 39b66a91bd which allowed freezing
in the heap_insert() code path but forgot to remove the corresponding
check in heap_xlog_insert(). This code is extraneous but not harmful.
However, cleaning it up makes it very clear that, as of now, we do not
support any freezing of pages in the heap_insert() path.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/flat/CAAKRu_Zp4Pi-t51OFWm1YZ-cctDfBhHCMZ%3DEx6PKxv0o8y2GvA%40mail.gmail.com
Backpatch-through: 14
We can simplify the VM counters added in dc6acfd910 to
lazy_vacuum_heap_page() and lazy_scan_new_or_empty().
We won't invoke lazy_vacuum_heap_page() unless there are dead line
pointers, so we know the page can't be all-visible.
In lazy_scan_new_or_empty(), we only update the VM if the page-level
hint PD_ALL_VISIBLE is clear, and the VM bit cannot be set if the page
level bit is clear because a subsequent page update would fail to clear
the visibility map bit.
Simplify the logic for determining which log counters to increment based
on this knowledge. Doing so is worthwhile because the old logic was
confusing and misguided.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_a9w_n2mwY%3DG4LjfWTvRTJtjbfvnYAKi4WjO8QXHHrA0g%40mail.gmail.com
We were missing collecting comments for not-null constraints that are
dumped inline with the table definition (i.e., valid ones), because they
aren't represented by a separately dumpable object. Fix by creating
separate TocEntries for the comments.
Co-Authored-By: Jian He <jian.universality@gmail.com>
Co-Authored-By: Álvaro Herrera <alvherre@kurilemu.de>
Reported-By: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-By: Fujii Masao <masao.fujii@oss.nttdata.com>
Discussion: https://postgr.es/m/d50ff977-c728-4e9e-8488-fc2688e08754@oss.nttdata.com
Commit 14e87ffa5c introduced support for adding comments to NOT NULL
constraints. However, CREATE TABLE LIKE INCLUDING COMMENTS did not copy
these comments to the new table. This was an oversight in that commit.
This commit corrects the behavior by ensuring CREATE TABLE LIKE to also copy
the comments on NOT NULL constraints when INCLUDING COMMENTS is specified.
Author: Jian He <jian.universality@gmail.com>
Co-authored-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/127debef-e558-4784-9e24-0d5eaf91e2d1@oss.nttdata.com
For the subcommand ALTER COLUMN TYPE of the ALTER TABLE command, the
USING expression may reference virtual generated columns. These
columns must be expanded before the expression is fed through
expression_planner and the expression-execution machinery. Failing to
do so can result in incorrect rewrite decisions, and can also lead to
"ERROR: unexpected virtual generated column reference".
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/b5f96b24-ccac-47fd-9e20-14681b894f36@gmail.com
Just like selecting from a view is exploitable (CVE-2024-7348),
selecting from a table with virtual generated columns is exploitable.
Users who are concerned about this can avoid selecting from views, but
telling them to avoid selecting from tables is less practical.
To address this, this changes it so that generation expressions for
virtual generated columns are restricted to using built-in functions
and types, and the columns are restricted to having a built-in type.
We assume that built-in functions and types cannot be exploited for
this purpose.
In the future, this could be expanded by some new mechanism to declare
other functions and types as safe or trusted for this purpose, but
that is to be designed.
(An alternative approach might have been to expand the
restrict_nonsystem_relation_kind GUC to handle this, like the fix for
CVE-2024-7348. But that is kind of an ugly approach. That fix had to
fit in the constraints of fixing an ancient vulnerability in all
branches. Since virtual generated columns are new, we're free from
the constraints of the past, and we can and should use cleaner
options.)
Reported-by: Feike Steenbergen <feikesteenbergen@gmail.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAK_s-G2Q7de8Q0qOYUR%3D_CTB5FzzVBm5iZjOp%2BmeVWpMpmfO0w%40mail.gmail.com
This fixes two issues with the handling of VacuumParams in vacuum_rel().
This code path has the idea to change the passed-in pointer of
VacuumParams for the "truncate" and "index_cleanup" options for the
relation worked on, impacting the two following scenarios where
incorrect options may be used because a VacuumParams pointer is shared
across multiple relations:
- Multiple relations in a single VACUUM command.
- TOAST relations vacuumed with their main relation.
The problem is avoided by providing to the two callers of vacuum_rel()
copies of VacuumParams, before the pointer is updated for the "truncate"
and "index_cleanup" options.
The refactoring of the VACUUM option and parameters done in 0d83138974
did not introduce an issue, but it has encouraged the problem we are
dealing with in this commit, with b84dbc8eb8 for "truncate" and
a96c41feec for "index_cleanup" that have been added a couple of years
after the initial refactoring. HEAD will be improved with a different
patch that hardens the uses of VacuumParams across the tree. This
cannot be backpatched as it introduces an ABI breakage.
The backend portion of the patch has been authored by Nathan, while I
have implemented the tests. The tests rely on injection points to check
the option values, making them faster, more reliable than the tests
originally proposed by Shihao, and they also provide more coverage.
This part can only be backpatched down to v17.
Reported-by: Shihao Zhong <zhong950419@gmail.com>
Author: Nathan Bossart <nathandbossart@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAGRkXqTo+aK=GTy5pSc-9cy8H2F2TJvcrZ-zXEiNJj93np1UUw@mail.gmail.com
Backpatch-through: 13
The logical replication launcher process would sometimes sleep
for as much as 3 minutes before noticing that it is supposed
to launch a new worker. This could happen if
(1) WaitForReplicationWorkerAttach absorbed a process latch wakeup
that was meant to cause ApplyLauncherMain to do work, or
(2) logicalrep_worker_launch reported failure, either because of
resource limits or because the new worker terminated immediately.
In case (2), the expected behavior is that we retry the launch after
wal_retrieve_retry_interval, but that didn't reliably happen.
It's not clear how often such conditions would occur in the field,
but in our subscription test suite they are somewhat common,
especially in tests that exercise cases that cause quick worker
failure. That causes the tests to take substantially longer than
they ought to do on typical setups.
To fix (1), make WaitForReplicationWorkerAttach re-set the latch
before returning if it cleared it while looping. To fix (2), ensure
that we reduce wait_time to no more than wal_retrieve_retry_interval
when logicalrep_worker_launch reports failure. In passing, fix a
couple of perhaps-hypothetical race conditions, e.g. examining
worker->in_use without a lock.
Backpatch to v16. Problem (2) didn't exist before commit 5a3a95385
because the previous code always set wait_time to
wal_retrieve_retry_interval when launching a worker, regardless of
success or failure of the launch. That behavior also greatly
mitigated problem (1), so I'm not excited about adapting the remainder
of the patch to the substantially-different code in older branches.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/817604.1750723007@sss.pgh.pa.us
Backpatch-through: 16
Commit 62d712ecfd made query jumbling squash lists of Consts as a
single element, but there's no reason not to treat PARAM_EXTERN
parameters the same. For these purposes, these values are indeed
constants for any particular execution of a query.
In particular, this should make list squashing more useful for
applications using extended query protocol, which would use parameters
extensively.
A complication arises: if a query has both external parameters and
squashable lists, then the parameter number used as placeholder for the
squashed list might be inconsistent with regards to the parameter
numbers used by the query literal. To reduce the surprise factor, all
parameters are renumbered starting from 1 in that case.
Author: Sami Imseih <samimseih@gmail.com>
Author: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAA5RZ0tRXoPG2y6bMgBCWNDt0Tn=unRerbzYM=oW0syi1=C1OA@mail.gmail.com
There's no principled reason for query jumbling to only remove the first
layer of RelabelType and CoerceViaIO. Change it to see through as many
layers as there are.
If vacuum fails to prune a tuple killed before OldestXmin, it will
decide to freeze its xmax and later error out in pre-freeze checks.
Add a test reproducing this scenario to the recovery suite which creates
a table on a primary, updates the table to generate dead tuples for
vacuum, and then, during the vacuum, uses a replica to force
GlobalVisState->maybe_needed on the primary to move backwards and
precede the value of OldestXmin set at the beginning of vacuuming the
table.
This test is coverage for a case fixed in 83c39a1f7f. The test was
originally committed to master in aa607980ae but later reverted in
efcbb76efe due to test instability.
The test requires multiple index passes. In Postgres 17+, vacuum uses a
TID store for the dead TIDs that is very space efficient. With the old
minimum maintenance_work_mem of 1 MB, it required a large number of dead
rows to generate enough dead TIDs to force multiple index
vacuuming passes. Once the source code changes were made to allow a
minimum maintenance_work_mem value of 64kB, the test could be made much
faster and more stable.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAAKRu_ZJBkidusDut6i%3DbDCiXzJEp93GC1%2BNFaZt4eqanYF3Kw%40mail.gmail.com
Backpatch-through: 17
\close has been introduced in d55322b0da to be able to close a
prepared statement using the extended protocol in psql. Per discussion,
the name "close" is ambiguous. At the SQL level, CLOSE is used to close
a cursor. At protocol level, the close message can be used to either
close a statement or a portal.
This patch renames \close to \close_prepared to avoid any ambiguity and
make it clear that this is used to close a prepared statement. This new
name has been chosen based on the feedback from the author and the
reviewers.
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Discussion: https://postgr.es/m/3e694442-0df5-4f92-a08f-c5d4c4346b85@eisentraut.org
This new test was intended to check the handling of the replication slot's
restart lsn fixed in ca307d5cec. However, it also reveals another issue
related to logical decoding. This commit temporarily removes this test to
keep the buildfarm and CFbot green and avoid distorting others' work. This
test will be restored once we investigate and fix the issue.
Discussion: https://postgr.es/m/CAAKRu_ZCOzQpEumLFgG_%2Biw3FTa%2BhJ4SRpxzaQBYxxM_ZAzWcA%40mail.gmail.com
ca307d5cec introduced keeping WAL segments by slot's last saved restart LSN.
It also added an assertion that the slot's restart LSN never goes backward.
However, situations when the restart LSN goes backward have been spotted by
buildfarm animals and investigated in the thread.
When pg_receivewal starts the replication, it sets the last replayed LSN to
the beginning of the segment, which is older than what
ReplicationSlotReserveWal() set for the slot. A similar situation can happen
to pg_basebackup. When standby reconnects to the primary, it sends the last
replayed LSN, which might be older than the last confirmed flush LSN. In
both these situations, a concurrent checkpoint may trigger an assert trap.
Based on ideas from Vitaly Davydov <v.davydov@postgrespro.ru>,
Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>,
Vignesh C <vignesh21@gmail.com>,
Amit Kapila <amit.kapila16@gmail.com>.
Reported-by: Vignesh C <vignesh21@gmail.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CALDaNm3s-jpQTe1MshsvQ8GO%3DTLj233JCdkQ7uZ6pwqRVpxAdw%40mail.gmail.com
Reviewed-by: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
The problem that led to the workaround in f83f14881c was not in fact
a compiler bug, but a failure to zero the upper bits of the vector
register containing the initial scalar CRC value. Fix that and revert
the workaround.
Diagnosed-by: Nathan Bossart <nathandbossart@gmail.com>
Diagnosed-by: Raghuveer Devulapalli <raghuveer.devulapalli@intel.com>
Tested-by: Andy Fan <zhihuifan1213@163.com>
Tested-by: Soumyadeep Chakraborty <soumyadeep2007@gmail.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Raghuveer Devulapalli <raghuveer.devulapalli@intel.com>
Discussion: https://postgr.es/m/PH8PR11MB82866B07AA6758D12F699C00FB70A@PH8PR11MB8286.namprd11.prod.outlook.com
Specify whether the bucket bounds are inclusive or exclusive,
and improve some other vague language. Explain the behavior that
occurs when the "low" bound is greater than the "high" bound.
Make width_bucket_numeric's comment more like that for
width_bucket_float8, in particular noting that infinite
bounds are rejected (since they became possible in v14).
Reported-by: Ben Peachey Higdon <bpeacheyhigdon@gmail.com>
Author: Robert Treat <rob@xzilla.net>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/2BD74F86-5B89-4AC1-8F13-23CED3546AC1@gmail.com
Backpatch-through: 13
Commit 85e5e222b, which added (a forerunner of) this logic,
argued that
Adding the necessary complexity to make this work doesn't seem like
it would be repaid in significantly better plans, because in cases
where such a PHV exists, there is probably a corresponding join order
constraint that would allow a good plan to be found without using the
star-schema exception.
The flaw in this claim is that there may be other join-order
restrictions that prevent us from finding a join order that doesn't
involve a "dangerous" PHV. In particular we now recognize that
small join_collapse_limit or from_collapse_limit could prevent it.
Therefore, let's bite the bullet and make the case work.
We don't have to extend the executor's support for nestloop parameters
as I thought at the time, because we can instead push the evaluation
of the placeholder's expression into the left-hand input of the
NestLoop node. So there's not really a lot of downside to this
solution, and giving the planner more join-order flexibility should
have value beyond just avoiding failure.
Having said that, there surely is a nonzero risk of introducing
new bugs. Since this failure mode escaped detection for ten years,
such cases don't seem common enough to justify a lot of risk.
Therefore, let's put this fix into master but leave the back branches
alone (for now anyway).
Bug: #18953
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Diagnosed-by: Richard Guo <guofenglinux@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18953-1c9883a9d4afeb30@postgresql.org
While choosing an autogenerated name for an index, look for
pre-existing relations using a SnapshotDirty snapshot, instead of the
previous behavior that considered only committed-good pg_class rows.
This allows us to detect and avoid conflicts against indexes that are
still being built.
It's still possible to fail due to a race condition, but the window
is now just the amount of time that it takes DefineIndex to validate
all its parameters, call smgrcreate(), and enter the index's pg_class
row. Formerly the race window covered the entire time needed to
create and fill an index, which could be very long if the table is
large. Worse, if the conflicting index creation is part of a larger
transaction, it wouldn't be visible till COMMIT.
So this isn't a complete solution, but it should greatly ameliorate
the problem, and the patch is simple enough to be back-patchable.
It might at some point be useful to do the same for pg_constraint
entries (cf. ChooseConstraintName, ConstraintNameExists, and related
functions). However, in the absence of field complaints, I'll leave
that alone for now. The relation-name test should be good enough for
index-based constraints, while foreign-key constraints seem to be okay
since they require exclusive locks to create.
Bug: #18959
Reported-by: Maximilian Chrzan <maximilian.chrzan@here.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Discussion: https://postgr.es/m/18959-f63b53b864bb1417@postgresql.org
Backpatch-through: 13
