Since a051e71e28, pg_stat_io is able to track statistics for the WAL
activity, providing an equivalent of pg_stat_wal with more granularity
for the fsyncs/writes counts and timings, as the data is split across
backend types.
This commit now recommends pg_stat_io rather than pg_stat_wal in the
section "WAL configuration", some of the latter's attributes being
candidate for removal in a follow-up commit.
Extracted from a larger patch by the same author.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/Z7RkQ0EfYaqqjgz/@ip-10-97-1-34.eu-west-3.compute.internal
If the requested recovery timeline is not reachable, the logged
checkpoint and timeline should to be the values read from the
backup_label when it is defined. The message generated used the values
from the control file in this case, which is fine when recovering from
the control file without a backup_label, but not if there is a
backup_label.
Issue introduced in ee994272ca. v15 has introduced xlogrecovery.c and
more simplifications in this area (4a92a1c3d1, a27048cbcb), making
this change a bit simpler to think about, so backpatch only down to this
version.
Author: David Steele <david@pgbackrest.org>
Reviewed-by: Andrey M. Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Benoit Lobréau <benoit.lobreau@dalibo.com>
Discussion: https://postgr.es/m/c3d617d4-1696-4aa7-8a4d-5a7d19cc5618@pgbackrest.org
Backpatch-through: 15
pgbench already had code to check if the soft rlimit is too low for the
specified number of connections. If too low, it errored out, telling the user
to increase the limit.
However, we can do better: If the hard limit allows, increase the soft limit
to be sufficiently for the number of connections.
It is common for the soft limit to be considerably lower than the hard limit,
due to the danger of soft limits > 1024 breaking programs that use the
select(2), as explained in [1].
[1]: https://0pointer.net/blog/file-descriptor-limits.html
Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAGECzQQh6VSy3KG4pN1d%3Dh9J%3DD1rStFCMR%2Bt7yh_Kwj-g87aLQ%40mail.gmail.com
Since commit 29cf61ade3, table_block_relation_estimate_size() considers
fillfactor when estimating number of rows in a relation before the first
ANALYZE. The formula however did not consider tuples may be larger than
available space determined by fillfactor, ending with density 0. This
ultimately means the relation was estimated to contain a single row.
The executor however places at least one tuple per page, even with very
low fillfactor values, so the density should be at least 1. Fixed by
clamping the density estimate using clamp_row_est().
Reported by Heikki Linnakangas. Fix by me, with regression test inspired
by example provided by Heikki.
Backpatch to 17, where the issue was introduced.
Reported-by: Heikki Linnakangas
Backpatch-through: 17
Discussion: https://postgr.es/m/2bf9d973-7789-4937-a7ca-0af9fb49c71e@iki.fi
These functions should be called at most once per ResultRelInfo;
it's wasteful to do otherwise, and certainly the pattern of
opening twice and then closing twice is a bad idea. Moreover,
aminsertcleanup functions might not be prepared to be called twice,
as the just-hardened code in BRIN demonstrates.
This amounts to an API change, since such coding patterns were
safe even if wasteful before v17. Hence, apply to HEAD only.
(Extension code violating this new rule faces some risk in v17,
but we just fixed brininsertcleanup and there are probably few
other aminsertcleanup functions as yet. So the odds of breaking
usable code seem higher than the odds of doing something useful
with a back-patch.)
Bug: #18815
Reported-by: Sergey Belyashov <sergey.belyashov@gmail.com>
Discussion: https://postgr.es/m/18815-2a0407cc7f40b327@postgresql.org
Logical replication crashes if the subscriber's partitioned table
has a BRIN index. There are two independently blamable causes,
and this patch fixes both:
1. brininsertcleanup fails if called twice for the same IndexInfo,
because it half-destroys its BrinInsertState but leaves it still
linked from ii_AmCache. brininsert would also fail in that state,
so it's pretty hard to see any advantage to this coding. Fully
remove the BrinInsertState, instead, so that a new brininsert
call would create a new cache.
2. A logical replication subscriber sometimes does ExecOpenIndices
twice on the same ResultRelInfo, followed by doing ExecCloseIndices
twice; the second call reaches the brininsertcleanup bug. Quite
aside from tickling unexpected cases in aminsertcleanup methods,
this seems very wasteful, because the IndexInfos built in the
first ExecOpenIndices call are just lost during the second call,
and have to be rebuilt at possibly-nontrivial cost. We should
establish a coding rule that you don't do that.
The problematic coding is that when the target table is partitioned,
apply_handle_tuple_routing calls ExecFindPartition which does
ExecOpenIndices (and expects that ExecCleanupTupleRouting will
close the indexes again). Using the ResultRelInfo made by
ExecFindPartition, it calls apply_handle_delete_internal or
apply_handle_insert_internal, both of which think they need to do
ExecOpenIndices/ExecCloseIndices for themselves. They do in the main
non-partitioned code paths, but not here. The simplest fix is to pull
their ExecOpenIndices/ExecCloseIndices calls out and put them in the
call sites for the non-partitioned cases. (We could have refactored
apply_handle_update_internal similarly, but I did not do so today
because there's no bug there: the partitioned code path doesn't
call it.)
Also, remove the always-duplicative open/close calls within
apply_handle_tuple_routing itself.
Since brininsertcleanup and indeed the whole aminsertcleanup mechanism
are new in v17, there's no observable bug in older branches. A case
could be made for trying to avoid these duplicative open/close calls
in the older branches, but for now it seems not worth the trouble and
risk of new bugs.
Bug: #18815
Reported-by: Sergey Belyashov <sergey.belyashov@gmail.com>
Discussion: https://postgr.es/m/18815-2a0407cc7f40b327@postgresql.org
Backpatch-through: 17
Until now ExecChooseHashTableSize() considered only the size of the
in-memory hash table, and ignored the memory needed for the batch files.
Which can be a significant amount, because each batch needs two BufFiles
(each with a BLCKSZ buffer). The same issue applies to increasing the
number of batches during execution.
It's also possible to trigger a "batch explosion", e.g. due to duplicate
values or skew. We've seen reports of joins with hundreds of thousands
(or even millions) of batches, consuming gigabytes of memory, triggering
OOM errors. These cases may be fairly rare, but it's clearly possible to
hit them.
These issues can't be prevented during planning. Even if we improve
that, it does not help with execution-time batch explosion. We can
however reduce the impact and use as little memory as possible.
This patch improves the behavior by adjusting how the memory is divided
between the hash table and batch files. It may be better to use fewer
batch files, even if it means the hash table will exceed the limit.
The capacity of the hash node may be increased either by doubling he
number of batches, or doubling the size of the in-memory hash table. The
outcome is the same, but the memory usage may be very different. For low
nbatch values it's better to add batches, for high nbatch values it's
better to allow a larger hash table.
The patch considers both options, both during the initial sizing and
then during execution, to minimize how much the limit gets exceeded.
It might seem this patch is relaxing the memory limit - allowing it to
be exceeded. But that's not really the case. It has always been like
that, except the memory used by batches was ignored.
Allowing the hash table to grow may also prevent the batch explosion.
If there's a large batch that can't be split (due to hash collisions or
duplicate values), at some point the memory limit will increase enough
for the batch to fit into the hash table.
This patch was in the works for a long time. The early versions were
posted in 2019, and revived every year or two when we happened to get
the next report of OOM due to a hashjoin batch explosion. Each of those
patch versions were reviewed by a couple people. I'm mentioning only
Melanie Plageman and Robert Haas, because they reviewed the last
version, and the older patches are very different.
Reviewed-by: Melanie Plageman, Robert Haas
Discussion: https://postgr.es/m/7bed6c08-72a0-4ab9-a79c-e01fcdd0940f@vondra.me
Discussion: https://postgr.es/m/20190504003414.bulcbnge3rhwhcsh%40development
Discussion: https://postgr.es/m/20190428141901.5dsbge2ka3rxmpk6%40development
This addresses various corner cases in BackgroundPsql:
- On windows stdout and stderr may arrive out of order, leading to errors not
being reported, or attributed to the wrong statement.
To fix, emit the "query-separation banner" on both stdout and stderr and
wait for both.
- Very occasionally the "query-separation banner" would not get removed, because
we waited until the banner arrived, but then replaced the banner plus
newline.
To fix, wait for banner and newline.
- For interactive psql replacing $banner\n is not sufficient, interactive psql
outputs \r\n.
- For interactive psql, where commands are echoed to stdout, the \echo
command, rather than its output, would be matched.
This would sometimes lead to output from the prior query, or wait_connect(),
being returned in the next command.
This also affected wait_connect(), leading to sometimes sending queries to
psql before the connection actually was established.
While debugging these issues I also found that it's hard to know whether a
query separation banner was attributed to the right query. Make that easier by
counting the queries each BackgroundPsql instance has emitted and include the
number in the banner.
Also emit psql stdout/stderr in query() and wait_connect() as Test::More
notes, without that it's rather hard to debug some issues in CI and buildfarm.
As this can cause issues not just to-be-added tests, but also existing ones,
backpatch the fix to all supported versions.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/wmovm6xcbwh7twdtymxuboaoarbvwj2haasd3sikzlb3dkgz76@n45rzycluzft
Backpatch-through: 13
Replace the use of Constraint with a new ATAlterConstraint struct, which
allows us to pass additional information. No functionality is added by
this commit. This is necessary for future work that allows altering
constraints in other ways.
I (Álvaro) took the liberty of restructuring the code for ALTER
CONSTRAINT beyond what Amul did. The original coding before Amul's
patch was unnecessarily baroque, and this change makes things simpler
by removing one level of subroutine. Also, partly remove the assumption
that only partitioned tables are relevant (by passing sensible 'recurse'
arguments) and no longer ignore whether ONLY was specified. I say
'partly' because the current coding only walks down via the 'conparentid'
relationship, which is only used for partitioned tables; but future
patches could handle ONLY or not for other types of constraint changes
for legacy inheritance trees too.
Author: Amul Sul <sulamul@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CAAJ_b94bfgPV-8Mw_HwSBeheVwaK9=5s+7+KbBj_NpwXQFgDGg@mail.gmail.com
This commit follows the idea of the 4767bc8ff2. If sub-query has only one
GROUP BY column, we can consider its output variable as being unique. We can
employ this fact in the statistics to make more precise estimations in the
upper query block.
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
This test uses an injection point to bypass the time overhead caused by
the idle_replication_slot_timeout GUC, which has a minimum value of one
minute.
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Author: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CALj2ACW4aUe-_uFQOjdWCEN-xXoLGhmvRFnL8SNw_TZ5nJe+aw@mail.gmail.com
LIKE enables the creation of foreign tables based on the column
definitions, constraints and objects of the defined source relation(s).
This feature mirrors the behavior of CREATE TABLE LIKE, but ignores
the INCLUDING sub-options that do not make sense for foreign tables:
INDEXES, COMPRESSION, IDENTITY and STORAGE. The supported sub-options
are COMMENTS, CONSTRAINTS, DEFAULTS, GENERATED and STATISTICS, mapping
with the clauses already supported by the command.
Note that the restriction with LIKE in CREATE FOREIGN TABLE was added in
a0c6dfeecf.
Author: Zhang Mingli
Reviewed-by: Álvaro Herrera, Sami Imseih, Michael Paquier
Discussion: https://postgr.es/m/42d3f855-2275-4361-a42a-826172ca2dc4@Spark
This commit introduces idle_replication_slot_timeout GUC that allows
inactive slots to be invalidated at the time of checkpoint. Because
checkpoints happen checkpoint_timeout intervals, there can be some lag
between when the idle_replication_slot_timeout was exceeded and when the
slot invalidation is triggered at the next checkpoint. To avoid such lags,
users can force a checkpoint to promptly invalidate inactive slots.
Note that the idle timeout invalidation mechanism is not applicable for
slots that do not reserve WAL or for slots on the standby server that are
synced from the primary server (i.e., standby slots having 'synced' field
'true'). Synced slots are always considered to be inactive because they
don't perform logical decoding to produce changes.
The slots can become inactive for a long period if a subscriber is down
due to a system error or inaccessible because of network issues. If such a
situation persists, it might be more practical to recreate the subscriber
rather than attempt to recover the node and wait for it to catch up which
could be time-consuming.
Then, external tools could create replication slots (e.g., for migrations
or upgrades) that may fail to remove them if an error occurs, leaving
behind unused slots that take up space and resources. Manually cleaning
them up can be tedious and error-prone, and without intervention, these
lingering slots can cause unnecessary WAL retention and system bloat.
As the duration of idle_replication_slot_timeout is in minutes, any test
using that would be time-consuming. We are planning to commit a follow up
patch for tests by using the injection point framework.
Author: Nisha Moond <nisha.moond412@gmail.com>
Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Hou Zhijie <houzj.fnst@fujitsu.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/CALj2ACW4aUe-_uFQOjdWCEN-xXoLGhmvRFnL8SNw_TZ5nJe+aw@mail.gmail.com
Discussion: https://postgr.es/m/OS0PR01MB5716C131A7D80DAE8CB9E88794FC2@OS0PR01MB5716.jpnprd01.prod.outlook.com
It's been some time since we did this, partly because the upstream
snowball project hasn't formally tagged a new release since 2021.
The main motivation for doing it now is to absorb a bug fix
(their commit e322673a841d9abd69994ae8cd20e191090b6ef4), which
prevents a null pointer dereference crash if SN_create_env() gets
a malloc failure at just the wrong point. We'll patch the back
branches with only that change, but we might as well do the full
sync dance on HEAD.
Aside from a bunch of mostly-minor tweaks to existing stemmers, this
update adds a new stemmer for Estonian. It also removes the existing
stemmer for Romanian using ISO-8859-2 encoding. Upstream apparently
concluded that ISO-8859-2 doesn't provide an adequate representation
of some Romanian characters, and the UTF-8 implementation should be
used instead.
While at it, update the README's instructions for doing a sync,
which have not been adjusted during the addition of meson tooling.
Thanks to Maksim Korotkov for discovering the null-pointer
bug and submitting the fix to upstream snowball.
Reported-by: Maksim Korotkov <m.korotkov@postgrespro.ru>
Discussion: https://postgr.es/m/1d1a46-67ab1000-21-80c451@83151435
When considering a local buffer, the GetBufferDescriptor() call in
BufferGetLSNAtomic() would be retrieving a shared buffer with a bad
buffer ID. Since the code checks whether the buffer is shared before
using the retrieved BufferDesc, this issue did not lead to any
malfunction. Nonetheless this seems like trouble waiting to happen,
so fix it by ensuring that GetBufferDescriptor() is only called when
we know the buffer is shared.
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAHewXNku-o46-9cmUgyv6LkSZ25doDrWq32p=oz9kfD8ovVJMg@mail.gmail.com
Backpatch-through: 13
In try_partitionwise_join, we try to break down the join between two
partitioned relations into joins between matching partitions. To
achieve this, we iterate through each pair of partitions from the two
joining relations and create child join relations for them. To reduce
memory accumulation during each iteration, one step we take is freeing
the SpecialJoinInfos created for the child joins.
A child join's SpecialJoinInfo is a copy of the parent join's
SpecialJoinInfo, with some members being translated copies of their
counterparts in the parent. However, when freeing the bitmapset
members in a child join's SpecialJoinInfo, we failed to check whether
they were translated copies. As a result, we inadvertently freed the
members that were still in use by the parent SpecialJoinInfo, leading
to crashes when those freed members were accessed.
To fix, check if each member of the child join's SpecialJoinInfo is a
translated copy and free it only if that's the case. This requires
passing the parent join's SpecialJoinInfo as a parameter to
free_child_join_sjinfo.
Back-patch to v17 where this bug crept in.
Bug: #18806
Reported-by: 孟令彬 <m_lingbin@126.com>
Diagnosed-by: Tender Wang <tndrwang@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/18806-d70b0c9fdf63dcbf@postgresql.org
Backpatch-through: 17
This commit improves the description of a couple of GUCs, to be more
consistent with the style of their surroundings:
* array_nulls
* enable_self_join_elimination
* optimize_bounded_sort
* row_security
* synchronize_seqscans
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20250218.103240.1422205966404509831.horikyota.ntt@gmail.com
Move lazy_scan_heap()'s per_buffer_data variable into a tighter scope.
In lazy_scan_heap()'s phase I heap vacuuming, the read stream API
returns a pointer to the next block number to vacuum. As long as
read_stream_next_buffer() returns a valid buffer, per_buffer_data should
always be valid.
Move per_buffer_data into a tighter scope and make sure it is reset to
NULL on each iteration so that we get a core dump instead of bogus data
from a previous block if something goes wrong in the read stream API.
Suggested-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/626104.1739729538%40sss.pgh.pa.us
bd10ec529 added code to allow redundant functionally dependent GROUP BY
columns to be removed using unique indexes and NOT NULL constraints as
proofs of functional dependency. In that commit, I (David) added a test
to ensure that when there are multiple indexes available to remove columns
that we pick the index that allows us to remove the most columns. This
test was faulty as it assumed the t3 table's primary key index was valid
to use as functional dependency proof, but that's not the case since
that's defined as deferrable.
Here we adjust the tests added by that commit to use the t2 table instead.
That's defined with a non-deferrable primary key.
Author: songjinzhou <tsinghualucky912@foxmail.com>
Author: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Discussion: https://postgr.es/m/tencent_CD414C79D39668455DF80D35143B87634C08@qq.com
During the pg_createsubscriber execution, it is possible that the required
WAL is removed from the primary/publisher node due to
'max_slot_wal_keep_size'.
This patch raises a WARNING during the '--dry-run' mode if the
'max_slot_wal_keep_size' is set to a non-default value on the
primary/publisher node.
Author: Shubham Khanna <khannashubham1197@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Vignesh C <vignesh21@gmail.com>
Discussion: https://postgr.es/m/CAHv8Rj+deqsQXOMa7Tck8CBQUbsua=+4AuMVQ2=MPM0f-ZHbjA@mail.gmail.com
There is at least one report in the field of storing millions of
integers in arrays, so it seems like a good time to specialize
intarray's qsort function. In doing so, streamline the comparators:
Previously there were three, two for each direction for sorting
and one passed to qunique_arg. To preserve the early exit in the
case of descending input, pass the direction as an argument to
the comparator. This requires giving up duplicate detection, which
previously allowed skipping the qunique_arg() call. Testing showed
no regressions this way.
In passing, get rid of nearby checks that the input has at least
two elements, since preserving them would make some macros less
readable. These are not necessary for correctness, and seem like
premature optimizations.
Author: Andrey M. Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/098A3E67-E4A6-4086-9C66-B1EAEB1DFE1C@yandex-team.ru
Builds configured with Valgrind but without assertions would fail due to
a typo in the recent change. This should be included when back-patching
2a8a0067 into v17.
The translator comments detailing what a %s inclusion refers to were
accidentally including too many address types. In practice this is
not a problem since it's not a translated string, but to minimize any
risk of confusion let's fix them anwyays. Even though this exists in
backbranches there is little use for backpatch as the translation work
has already happened there, so let's avoid the churn.
Author: Japin Li <japinli@hotmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/ME0P300MB04458DE627480614ABE639D2B6FB2@ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
Currently tab completion for ALTER USER RESET shows a list of all
configuration parameters that may be set on a role, irrespectively of
which parameters are actually set. This patch improves tab completion to
offer only parameters that are set.
Author: Robins Tharakan
Reviewed-By: Tomas Vondra
Discussion: https://postgr.es/m/CAEP4nAzqiT6VbVC5r3nq5byLTnPzjniVGzEMpYcnAHQyNzEuaw%40mail.gmail.com
Currently tab completion for ALTER DATABASE RESET shows a list of all
configuration parameters that may be set on a database, irrespectively
of which parameters are actually set. This patch improves tab completion
to offer only parameters that are set.
Author: Robins Tharakan
Reviewed-By: Tomas Vondra
Discussion: https://postgr.es/m/CAEP4nAzqiT6VbVC5r3nq5byLTnPzjniVGzEMpYcnAHQyNzEuaw%40mail.gmail.com
The Self-Join Elimination (SJE) feature removes an inner join of a plain
table to itself in the query tree if it is proven that the join can be
replaced with a scan without impacting the query result. Self-join and
inner relation get replaced with the outer in query, equivalence classes,
and planner info structures. Also, the inner restrictlist moves to the
outer one with the removal of duplicated clauses. Thus, this optimization
reduces the length of the range table list (this especially makes sense for
partitioned relations), reduces the number of restriction clauses and,
in turn, selectivity estimations, and potentially improves total planner
prediction for the query.
This feature is dedicated to avoiding redundancy, which can appear after
pull-up transformations or the creation of an EquivalenceClass-derived clause
like the below.
SELECT * FROM t1 WHERE x IN (SELECT t3.x FROM t1 t3);
SELECT * FROM t1 WHERE EXISTS (SELECT t3.x FROM t1 t3 WHERE t3.x = t1.x);
SELECT * FROM t1,t2, t1 t3 WHERE t1.x = t2.x AND t2.x = t3.x;
In the future, we could also reduce redundancy caused by subquery pull-up
after unnecessary outer join removal in cases like the one below.
SELECT * FROM t1 WHERE x IN
(SELECT t3.x FROM t1 t3 LEFT JOIN t2 ON t2.x = t1.x);
Also, it can drastically help to join partitioned tables, removing entries
even before their expansion.
The SJE proof is based on innerrel_is_unique() machinery.
We can remove a self-join when for each outer row:
1. At most, one inner row matches the join clause;
2. Each matched inner row must be (physically) the same as the outer one;
3. Inner and outer rows have the same row mark.
In this patch, we use the next approach to identify a self-join:
1. Collect all merge-joinable join quals which look like a.x = b.x;
2. Add to the list above the baseretrictinfo of the inner table;
3. Check innerrel_is_unique() for the qual list. If it returns false, skip
this pair of joining tables;
4. Check uniqueness, proved by the baserestrictinfo clauses. To prove the
possibility of self-join elimination, the inner and outer clauses must
match exactly.
The relation replacement procedure is not trivial and is partly combined
with the one used to remove useless left joins. Tests covering this feature
were added to join.sql. Some of the existing regression tests changed due
to self-join removal logic.
Discussion: https://postgr.es/m/flat/64486b0b-0404-e39e-322d-0801154901f3%40postgrespro.ru
Author: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
Author: Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Co-authored-by: Alena Rybakina <lena.ribackina@yandex.ru>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Simon Riggs <simon@2ndquadrant.com>
Reviewed-by: Jonathan S. Katz <jkatz@postgresql.org>
Reviewed-by: David Rowley <david.rowley@2ndquadrant.com>
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Konstantin Knizhnik <k.knizhnik@postgrespro.ru>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Hywel Carver <hywel@skillerwhale.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Ronan Dunklau <ronan.dunklau@aiven.io>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Greg Stark <stark@mit.edu>
Reviewed-by: Jaime Casanova <jcasanov@systemguards.com.ec>
Reviewed-by: Michał Kłeczek <michal@kleczek.org>
Reviewed-by: Alena Rybakina <lena.ribackina@yandex.ru>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
ExecInitModifyTable() forgot to trim MERGE-related lists to exclude
entries for result relations pruned during initial pruning, so fix
that.
While at it, make the function's use of the pruned resultRelations
list, rather than ModifyTable.resultRelations, more consistent.
Reported-by: Alexander Lakhin <exclusion@gmail.com> (via sqlsmith)
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/e72c94d9-e5f9-4753-9bc1-69d72bd54b8a@gmail.com
This commit adds the information about the number of times WAL buffers
have been full to the logs generated by VACUUM/ANALYZE (VERBOSE) and in
the logs generated by autovacuum, complementing the existing information
stored by WalUsage.
This is the last part of the backend code where the value of
wal_buffers_full can be reported, similarly to all the other fields of
WalUsage. 320545bfcf and ce5bcc4a9f have done the same for EXPLAIN
and pgss.
Author: Bertrand Drouvot
Reviewed-by: Ilia Evdokimov
Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal
wal_buffers_full tracks the number of times WAL buffers become full,
giving hints to be able to tune the GUC wal_buffers.
Up to now, this information was only available in pg_stat_wal. With
this field available in WalUsage since eaf502747b, exposing it in
pg_stat_statements is straight-forward, and it offers more granularity
at query level.
pg_stat_statements does not need a version bump as one has been done in
commit cf54a2c002 for this development cycle.
Author: Bertrand Drouvot
Reviewed-by: Ilia Evdokimov
Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal
wal_buffers_full has been introduced in pg_stat_wal in 8d9a935965, as
some information providing metrics for the tuning of the GUC
wal_buffers. WalUsage has been introduced before that in df3b181499.
Moving this field is proving to be beneficial for several reasons:
- This information can now be made available in more layers, providing
more granularity than just pg_stat_wal, on a per-query basis: EXPLAIN,
pgss and VACUUM/ANALYZE logs.
- A patch is under discussion to provide statistics for WAL at backend
level, and this move simplifies a bit the handling of pending
statistics. The remaining data in PgStat_PendingWalStats now relates to
write/sync counters and times, with equivalents present in pg_stat_io,
that backend statistics are able to already track. So this should cut
all the dependencies between PgStat_PendingWalStats and WAL stats at
backend level.
As of this change, wal_buffers_full only shows in pg_stat_wal.
Author: Bertrand Drouvot
Reviewed-by: Ilia Evdokimov
Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal
Allow multiple backends to initialize WAL buffers concurrently. This way
`MemSet((char *) NewPage, 0, XLOG_BLCKSZ);` can run in parallel without
taking a single LWLock in exclusive mode.
The new algorithm works as follows:
* reserve a page for initialization using XLogCtl->InitializeReserved,
* ensure the page is written out,
* once the page is initialized, try to advance XLogCtl->InitializedUpTo and
signal to waiters using XLogCtl->InitializedUpToCondVar condition
variable,
* repeat previous steps until we reserve initialization up to the target
WAL position,
* wait until concurrent initialization finishes using a
XLogCtl->InitializedUpToCondVar.
Now, multiple backends can, in parallel, concurrently reserve pages,
initialize them, and advance XLogCtl->InitializedUpTo to point to the latest
initialized page.
Author: Yura Sokolov <y.sokolov@postgrespro.ru>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
In set_append_rel_size(), we currently set rel->tuples to rel->rows
for an appendrel. Generally, rel->tuples is the raw number of tuples
in the relation and rel->rows is the estimated number of tuples after
the relation's restriction clauses have been applied. Although an
appendrel itself doesn't directly enforce any quals today, its child
relations may. Therefore, setting rel->tuples equal to rel->rows for
an appendrel isn't always appropriate.
Doing so can lead to issues in cost estimates in some cases. For
instance, when estimating the number of distinct values from an
appendrel, we would not be able to adjust the estimate based on the
restriction selectivity.
This patch addresses this by setting an appendrel's tuples to the
total number of tuples accumulated from each live child, which better
aligns with reality.
This is arguably a bug, but nobody has complained about that until
now, so no back-patch.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Alena Rybakina <a.rybakina@postgrespro.ru>
Discussion: https://postgr.es/m/CAMbWs4_TG_+kVn6fjG-5GYzzukrNK57=g9eUo4gsrUG26OFawg@mail.gmail.com
Coverity complained that we weren't doing that, and it's right.
This fix just makes fmtIdEnc() honor the general convention that OOM
causes a PQExpBuffer to become marked "broken", without any immediate
error. In the pretty-unlikely case that we actually did hit OOM here,
the end result would be to return an empty string to the caller,
probably resulting in invalid SQL syntax in an issued command (if
nothing else went wrong, which is even more unlikely). It's tempting
to throw an "out of memory" error if the buffer becomes broken, but
there's not a lot of point in doing that only here and not in hundreds
of other PQExpBuffer-using places in pg_dump and similar callers.
The whole issue could do with some non-time-crunched redesign, perhaps.
This is a followup to the fixes for CVE-2025-1094, and should be
included if cherry-picking those fixes.
Instead of dropping the trailing byte(s) of an invalid or incomplete
multibyte character, replace only the first byte with a known-invalid
sequence, and process the rest normally. This seems less likely to
confuse incautious callers than the behavior adopted in 5dc1e42b4.
While we're at it, adjust PQescapeStringInternal to produce at most
one bleat about invalid multibyte characters per string. This
matches the behavior of PQescapeInternal, and avoids the risk of
producing tons of repetitive junk if a long string is simply given
in the wrong encoding.
This is a followup to the fixes for CVE-2025-1094, and should be
included if cherry-picking those fixes.
Author: Andres Freund <andres@anarazel.de>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://postgr.es/m/20250215012712.45@rfd.leadboat.com
Backpatch-through: 13
By calling wipe_mem() on per-buffer data memory that has been released,
we are also telling Valgrind that the memory is "noaccess". We need to
set it to "undefined" before giving it to the registered callback to
fill in, when a slot is reused.
As discovered by build farm animal skink when the VACUUM streamification
patches landed (the first users of per-buffer data).
Pushing to master only for now, to clear the error on skink. It's also
possible that external code might discover the per-buffer data feature
in v17, and reasonable to expect Valgrind not to produce spurious
memcheck reports, but the back-patch is deferred until after the
imminent minor release is out of the way.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Tested-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKG%2Bg6aXpi2FEHqeLOzE%2BxYw%3DOV%2B-N5jhOEnnV%2BF0USM9xA%40mail.gmail.com
In 5dc1e42b4f I fixed bugs in various escape functions, unfortunately as part
of that I introduced a new bug in PQescapeLiteral()/PQescapeIdentifier(). The
bug is that I made PQescapeInternal() just use strlen(), rather than taking
the specified input length into account.
That's bad, because it can lead to including input that wasn't intended to be
included (in case len is shorter than null termination of the string) and
because it can lead to reading invalid memory if the input string is not null
terminated.
Expand test_escape to this kind of bug:
a) for escape functions with length support, append data that should not be
escaped and check that it is not
b) add valgrind requests to detect access of bytes that should not be touched
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Andres Freund <andres@anarazel.de
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/Z64jD3u46gObCo1p@pryzbyj2023
Backpatch: 13
Commit bb8dff9995 added this information to the
pg_stat_progress_vacuum and pg_stat_progress_analyze system views.
This commit adds the same information to the output of VACUUM and
ANALYZE with the VERBOSE option and to the autovacuum logs.
Suggested-by: Masahiro Ikeda <ikedamsh@oss.nttdata.com>
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/ZmaXmWDL829fzAVX%40ip-10-97-1-34.eu-west-3.compute.internal
Cipher Feedback Mode, CFB, is a self-synchronizing stream cipher which
is very similar to CBC performed in reverse. Since OpenSSL supports it,
we can easily plug it into the existing cipher selection code without
any need for infrastructure changes.
This patch was simultaneously submitted by Umar Hayat and Vladyslav
Nebozhyn, the latter whom suggested the feauture. The committed patch
is Umar's version.
Author: Umar Hayat <postgresql.wizard@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CAPBGcbxo9ASzq14VTpQp3mnUJ5omdgTWUJOvWV0L6nNigWE5jw@mail.gmail.com
Make vacuum's third phase (its second pass over the heap), which reaps
dead items collected in the first phase and marks them as reusable, use
the read stream API. This commit adds a new read stream callback,
vacuum_reap_lp_read_stream_next(), that looks ahead in the TidStore and
returns the next block number to read for vacuum.
Author: Melanie Plageman <melanieplageman@gmail.com>
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKGKN3oy0bN_3yv8hd78a4%2BM1tJC9z7mD8%2Bf%2ByA%2BGeoFUwQ%40mail.gmail.com
Make vacuum's first phase, which prunes and freezes tuples and records
dead TIDs, use the read stream API by by converting
heap_vac_scan_next_block() to a read stream callback.
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CAAKRu_aLwANZpxHc0tC-6OT0OQT4TftDGkKAO5yigMUOv_Tcsw%40mail.gmail.com
Michael Paquier