In an XMLTABLE expression, columns can be marked NOT NULL, and the
parser internally fabricates an option named "is_not_null" to
represent this. However, the parser also allows users to specify
arbitrary option names. This creates a conflict: a user can
explicitly use "is_not_null" as an option name and assign it a
non-Boolean value, which violates internal assumptions and triggers an
assertion failure.
To fix, this patch checks whether a user-supplied name collides with
the internally reserved option name and raises an error if so.
Additionally, the internal name is renamed to "__pg__is_not_null" to
further reduce the risk of collision with user-defined names.
Reported-by: Евгений Горбанев <gorbanyoves@basealt.ru>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/6bac9886-65bf-4cec-96bd-e304159f28db@basealt.ru
Backpatch-through: 15
When creating a new PlannerGlobal node in standard_planner(), most
fields are explicitly initialized, but a few are not. This doesn't
cause any functional issues, as makeNode() zeroes all fields by
default. However, the inconsistency is undesirable from a clarity and
maintenance perspective.
This patch explicitly initializes the remaining fields to improve
consistency and readability.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAMbWs4-TgQHNOiouqGcuHoBqbJjWyx4UxGKxUY3FrF4trGbcPA@mail.gmail.com
As complained about by Valgrind, in commit a379061a22 I failed to
realize that I was causing rd_att->constr->check to become allocated
when no CHECK constraints exist; previously it'd remain NULL. (This was
my bug, not the mentioned commit author's). Fix by making the
allocation conditional, and set ->check to NULL if unallocated.
Reported-by: Yasir <yasir.hussain.shah@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/202505082025.57ijx3qrbx7u@alvherre.pgsql
This must be "return MemoryContextAllocationFailure(context, size, flags)"
instead. The effect of this oversight is that if we got a malloc
failure right here, the code would act as though MCXT_ALLOC_NO_OOM
had been specified, whether it was or not. That would likely lead
to a null-pointer-dereference crash at the unsuspecting call site.
Noted while messing with a patch to improve our Valgrind leak
detection support. Back-patch to v17 where this code came in.
Commit f4ece891fc added the assertion in
an attempt to catch some defects even after VACUUM FULL or REINDEX.
However, IsCatalogTextUniqueIndexOid(tag.relNumber) always returns false
after a relfilenode change, provoking unintended assertion failures.
Reported-by: Adam Guo <adamguo@amazon.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Bug: #18912
Discussion: https://postgr.es/m/18912-a41c9bd0e0ad19b1@postgresql.org
This cleans up the code related to the testing infrastructure of AIO
that used injection points, switching the test code to use the new
facility for injection points added by 371f2db8b0 rather than tweaks
to pass and reset arguments to the callbacks run.
This removes all the dependencies to USE_INJECTION_POINTS in the AIO
code. pgaio_io_call_inj(), pgaio_inj_io_get() and pgaio_inj_cur_handle
are now gone.
Reviewed-by: Greg Burd <greg@burd.me>
Discussion: https://postgr.es/m/Z_y9TtnXubvYAApS@paquier.xyz
The macros INJECTION_POINT() and INJECTION_POINT_CACHED() are extended
with an optional argument that can be passed down to the callback
attached when an injection point is run, giving to callbacks the
possibility to manipulate a stack state given by the caller. The
existing callbacks in modules injection_points and test_aio have their
declarations adjusted based on that.
da7226993f (core AIO infrastructure) and 93bc3d75d8 (test_aio) and
been relying on a set of workarounds where a static variable called
pgaio_inj_cur_handle is used as runtime argument in the injection point
callbacks used by the AIO tests, in combination with a TRY/CATCH block
to reset the argument value. The infrastructure introduced in this
commit will be reused for the AIO tests, simplifying them.
Reviewed-by: Greg Burd <greg@burd.me>
Discussion: https://postgr.es/m/Z_y9TtnXubvYAApS@paquier.xyz
A 'void *' argument suggests that the caller might pass an arbitrary
struct, which is appropriate for functions like libc's read/write, or
pq_sendbytes(). 'uint8 *' is more appropriate for byte arrays that
have no structure, like the cancellation keys or SCRAM tokens. Some
places used 'char *', but 'uint8 *' is better because 'char *' is
commonly used for null-terminated strings. Change code around SCRAM,
MD5 authentication, and cancellation key handling to follow these
conventions.
Discussion: https://www.postgresql.org/message-id/61be9e31-7b7d-49d5-bc11-721800d89d64@eisentraut.org
When creating an explicit Sort node for the outer path of a mergejoin,
we need to determine the number of presorted keys of the outer path to
decide whether explicit incremental sort can be applied. Currently,
this is done by repeatedly calling pathkeys_count_contained_in.
This patch caches the number of presorted outer pathkeys in MergePath,
allowing us to save several calls to pathkeys_count_contained_in. It
can be considered a complement to the changes in commit 828e94c9d.
Reported-by: David Rowley <dgrowleyml@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/CAApHDvqvBireB_w6x8BN5txdvBEHxVgZBt=rUnpf5ww5P_E_ww@mail.gmail.com
When building a ForeignPath for a joinrel, if there's a possibility
that EvalPlanQual will be executed, we must identify a suitable path
for EPQ checks. If the outer or inner path of the chosen path is a
ForeignPath representing a pushed-down join, we replace it with its
fdw_outerpath to ensure that the EPQ check path consists entirely of
local joins.
If the chosen path is a MergePath, and its outer or inner path is a
ForeignPath that is not already well enough ordered, the MergePath
will have non-NIL outersortkeys or innersortkeys indicating the
desired ordering to be created by an explicit Sort node. If we then
replace the outer or inner path with its corresponding fdw_outerpath,
and that path is already sufficiently ordered, we end up in an
inconsistent state: the MergePath has non-NIL outersortkeys or
innersortkeys, and its input path is already properly ordered. This
inconsistency can result in an Assert failure or the addition of a
redundant Sort node.
To fix, check if the new outer or inner path of a MergePath is already
properly sorted, and set its outersortkeys or innersortkeys to NIL if
so.
Bug: #18902
Reported-by: Nikita Kalinin <n.kalinin@postgrespro.ru>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/18902-71c1bed2b9f7c46f@postgresql.org
A few places that access this catalog don't set up an active
snapshot before potentially accessing its TOAST table. However,
roname (the replication origin name) is the only varlena column, so
this is only a problem if the name requires out-of-line storage.
This commit removes its TOAST table to avoid needing to set up a
snapshot. It also places a limit on replication origin names so
that attempts to set long names will fail with a more user-friendly
error. Those chosen limit of 512 bytes should be sufficient to
avoid "row is too big" errors independent of BLCKSZ, but it should
also be lenient enough for all reasonable use-cases.
Bumps catversion.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/ZvMSUPOqUU-VNADN%40nathan
nbtree array index scans could fail to return matching tuples in rare
cases where the missed tuples cover key space that the scan's arrays
incorrectly indicate has already been read. These cases involved nearby
tuples with NULL values that were evaluated using a skip array key while
in pstate.forcenonrequired mode.
To fix, prevent forcenonrequired mode from prematurely advancing the
scan's array keys beyond key space that the scan has yet to read tuples
from: reset the scan's array keys (to the first elements in the current
scan direction) before the _bt_checkkeys call for pstate.finaltup. That
way _bt_checkkeys starts from a clean slate, which ensures that it will
call _bt_advance_array_keys (while passing it sktrig_required=true).
This reliably restores the invariant that the scan's arrays always
accurately track its progress through the index's key space (at least
when the scan is "between pages").
Oversight in commit 8a510275, which optimized nbtree search scan key
comparisons.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://postgr.es/m/CAH2-WzmodSE+gpTd1CRGU9ez8ytyyDS+Kns2r9NzgUp1s56kpw@mail.gmail.com
Be more conservative when performing a scheduled recheck of an nbtree
scan's array keys once on the next page, having set so->scanBehind: back
out of reading the page (perform another primitive scan instead) when
the next page's high key/finaltup has an untruncated prefix of matching
values and truncated suffix attributes associated with lower-order keys.
In other words, stop assuming that the lower-order keys have been
satisfied by the truncated suffix attributes in this context (only do so
when considering scheduling a recheck within _bt_advance_array_keys).
The new behavior is more logical: if the next page read after setting
so->scanBehind can only contain tuples that are themselves "behind the
scan", that's reason enough to cut our losses. In general, when we set
so->scanBehind, we only expect to perform one recheck on the next page
to make a final decision about whether or not to continue the current
primitive index scan. It seems unprincipled for the recheck to allow a
_bt_readpage to continue unless the scan's arrays will advance/unless
the page might actually contain relevant tuples.
In practice it is highly unlikely that things will line up like this
(the untruncated prefix of attribute values from the next page's high
key is seldom an exact match for their corresponding array's current
element following array advancement on the original/previous page).
That gives us all the more reason to keep things simple and consistent.
This was arguably an oversight in commit 9a2e2a285a, which improved
nbtree array primitive scan scheduling.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WzkXzJajgyW-pCQ7vaDPhaT3huU+Zw_j448rpCBEsu2YOQ@mail.gmail.com
fc069a3a63 implemented Self-Join Elimination (SJE) and put related logic
to ChangeVarNodes_walker(). This commit provides refactoring to remove the
SJE-related logic from ChangeVarNodes_walker() but adds a custom callback to
ChangeVarNodesExtended(), which has a chance to process a node before
ChangeVarNodes_walker(). Passing this callback to ChangeVarNodesExtended()
allows SJE-related node handling to be kept within the analyzejoins.c.
Reported-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com
Author: Andrei Lepikhov <lepihov@gmail.com>
Author: Alexander Korotkov <aekorotkov@gmail.com>
IO workers are treated as auxiliary processes. The comments fixed in
this commit stated that there could be only one auxiliary process of
each BackendType at the same time. This is not true for IO workers, as
up to MAX_IO_WORKERS of them can co-exist at the same time.
Author: Cédric Villemain <Cedric.Villemain@data-bene.io>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/e4a3ac45-abce-4b58-a043-b4a31cd11113@Data-Bene.io
With GB18030 as source encoding, applications could crash the server via
SQL functions convert() or convert_from(). Applications themselves
could crash after passing unterminated GB18030 input to libpq functions
PQescapeLiteral(), PQescapeIdentifier(), PQescapeStringConn(), or
PQescapeString(). Extension code could crash by passing unterminated
GB18030 input to jsonapi.h functions. All those functions have been
intended to handle untrusted, unterminated input safely.
A crash required allocating the input such that the last byte of the
allocation was the last byte of a virtual memory page. Some malloc()
implementations take measures against that, making the SIGSEGV hard to
reach. Back-patch to v13 (all supported versions).
Author: Noah Misch <noah@leadboat.com>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Backpatch-through: 13
Security: CVE-2025-4207
fc069a3a63 implemented Self-Join Elimination (SJE) and put related logic
to ChangeVarNodes_walker(). This commit provides refactoring to remove the
SJE-related logic from ChangeVarNodes_walker() but adds a custom callback to
ChangeVarNodesExtended(), which has a chance to process a node before
ChangeVarNodes_walker(). Passing this callback to ChangeVarNodesExtended()
allows SJE-related node handling to be kept within the analyzejoins.c.
Reported-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com
Author: Andrei Lepikhov <lepihov@gmail.com>
Author: Alexander Korotkov <aekorotkov@gmail.com>
The previous code was allocating more memory and copying more data than
necessary because it specified the wrong PgStat_KindInfo member as the
size argument for MemoryContextAlloc and memcpy, respectively.
Although these issues exist since 5891c7a8e, there have been no reports
from the field. So for now, it seems sufficient to fix them in master.
Author: Etsuro Fujita <etsuro.fujita@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Gurjeet Singh <gurjeet@singh.im>
Discussion: https://postgr.es/m/CAPmGK15eTRCZTnfgQ4EuBNo%3DQLYGFEbXS_7m2dXqtkcT7L8qrQ%40mail.gmail.com
Also adjust the phrasing in the comments.
Author: Etsuro Fujita <etsuro.fujita@gmail.com>
Author: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Gurjeet Singh <gurjeet@singh.im>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAPmGK17%3DPHSDZ%2B0G6jcj12buyyE1bQQc3sbp1Wxri7tODT-SDw%40mail.gmail.com
Backpatch-through: 15
Consistently prevent nbtree array advancement from treating a scankey as
required when operating in pstate.forcenonrequired mode. Otherwise, we
risk a NULL pointer dereference. This was possible in the path where
_bt_check_compare is called to recheck a tuple that advanced all of the
scan's arrays to matching values: its continuescan=false handling
expects _bt_advance_array_keys to have been called with a valid pstate,
but it'll always be NULL during sktrig_required=false calls (which is
how _bt_advance_array_keys must be called when pstate.forcenonrequired).
Oversight in commit 8a510275, which optimized nbtree search scan key
comparisons.
Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://postgr.es/m/CAHgHdKsn2W=gPBmj7p6MjQFvxB+zZDBkwTSg0o3f5Hh8rkRrsA@mail.gmail.com
Discussion: https://postgr.es/m/CAH2-WzmodSE+gpTd1CRGU9ez8ytyyDS+Kns2r9NzgUp1s56kpw@mail.gmail.com
To insert the merged GIN entries in _gin_parallel_merge, the leader
calls ginEntryInsert(). This may allocate memory, e.g. for a new leaf
tuple. This was allocated in the PortalContext, and kept until the end
of the index build. For most GIN indexes the amount of leaked memory is
negligible, but for custom opclasses with large keys it may cause OOMs.
Fixed by calling ginEntryInsert() in a temporary memory context, reset
after each insert. Other ginEntryInsert() callers do this too, except
that the context is reset after batches of inserts. More frequent resets
don't seem to hurt performance, it may even help it a bit.
Report and fix by Vinod Sridharan.
Author: Vinod Sridharan <vsridh90@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAFMdLD4p0VBd8JG=Nbi=BKv6rzFAiGJ_sXSFrw-2tNmNZFO5Kg@mail.gmail.com
We only need a tuplestore if we're actually going to accumulate
multiple result tuples. Obviously then we don't need one for non-set-
returning functions; but even a SRF doesn't need one if we decide to
use "lazyEval" (one row at a time) mode. In these cases, it's
sufficient to use the junkfilter's result slot to hold the single row
that's due to be returned. We just need to "materialize" that slot
to ensure it holds onto the data past shutdown of the sub-executor.
The original intent of this patch was partially to save a few cycles
(by not putting tuples into a tuplestore only to pull them back out
immediately), but mostly to ensure that we don't use a tuplestore
in non-set-returning functions. That's because I had concerns
about whether a tuplestore is safe to keep across queries,
which was possible for functions invoked via long-lived FmgrInfos
such as those kept in the typcache. There are no cases where SRFs
are called that way, so getting rid of the tuplestore in non-SRFs
should make things safer.
However, it emerges that running fmgr_sql in a short-lived context
(as 595d1efed made it do) makes the existing coding unsafe anyway:
we can end up with a long-lived TupleTableSlot holding a freeable
reference to a short-lived tuple, resulting in a double-free crash.
Not trying to pull tuples out of the tuplestore using that slot
dodges the problem, so I'm going to commit this now rather than
invent a band-aid solution for v18.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/2443532.1744919968@sss.pgh.pa.us
Discussion: https://postgr.es/m/9f975803-1a1c-4f21-b987-f572e110e860@gmail.com
For self-referencing foreign keys in partitioned tables, we weren't
handling creation of pg_constraint rows during CREATE TABLE PARTITION AS
as well as ALTER TABLE ATTACH PARTITION. This is an old bug -- mostly,
we broke this in 614a406b4f while trying to fix it (so 12.13, 13.9,
14.6 and 15.0 and up all behave incorrectly). This commit reverts part
of that with additional fixes for full correctness, and installs more
tests to verify the parts we broke, not just the catalog contents but
also the user-visible behavior.
Backpatch to all live branches. In branches 13 and 14, commit
46a8c27a72 changed the behavior during DETACH to drop a FK
constraint rather than trying to repair it, because the complete fix of
repairing catalog constraints was problematic due to lack of previous
fixes. For this reason, the test behavior in those branches is a bit
different. However, as best as I can tell, the fix works correctly
there.
In release notes we have to recommend that all self-referencing foreign
keys on partitioned tables be recreated if partitions have been created
or attached after the FK was created, keeping in mind that violating
rows might already be present on the referencing side.
Reported-by: Guillaume Lelarge <guillaume@lelarge.info>
Reported-by: Matthew Gabeler-Lee <fastcat@gmail.com>
Reported-by: Luca Vallisa <luca.vallisa@gmail.com>
Discussion: https://postgr.es/m/CAECtzeWHCA+6tTcm2Oh2+g7fURUJpLZb-=pRXgeWJ-Pi+VU=_w@mail.gmail.com
Discussion: https://postgr.es/m/18156-a44bc7096f0683e6@postgresql.org
Discussion: https://postgr.es/m/CAAT=myvsiF-Attja5DcWoUWh21R12R-sfXECY2-3ynt8kaOqjw@mail.gmail.com
The extension_control_path setting (commit 4f7f7b0375) did not
support extensions that set a custom "directory" setting in their
control file. Very few extensions use that and during the discussion
on the previous commit it was suggested to maybe remove that
functionality. But a fix was easier than initially thought, so this
just adds that support. The fix is to use the control->control_dir as
a share dir to return the path of the extension script files.
To make this work more sensibly overall, the directory suffix
"extension" is no longer to be included in the extension_control_path
value. To quote the patch, it would be
-extension_control_path = '/usr/local/share/postgresql/extension:/home/my_project/share/extension:$system'
+extension_control_path = '/usr/local/share/postgresql:/home/my_project/share:$system'
During the initial patch, there was some discussion on which of these
two approaches would be better, and the committed patch was a 50/50
decision. But the support for the "directory" setting pushed it the
other way, and also it seems like many people didn't like the previous
behavior much.
Author: Matheus Alcantara <mths.dev@pm.me>
Reviewed-by: Christoph Berg <myon@debian.org>
Reviewed-by: David E. Wheeler <david@justatheory.com>
Discussion: https://www.postgresql.org/message-id/flat/aAi1VACxhjMhjFnb%40msg.df7cb.de#0cdf7b7d727cc593b029650daa3c4fbc
Make an nbtree array preprocessing assertion account for scans that add
fewer skip arrays than initially expected due to preprocessing finding
an unsatisfiable array qual.
Oversight in commit 92fe23d9.
Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://postgr.es/m/CAHgHdKtQMhHy5qcB3KqCcGiW-Rp8P7KzUFRa9ZMKUiv6zen7LQ@mail.gmail.com
We try to avoid using strncpy() due to the ease of which it can
be misused. Convert this callsite to use strlcpy() instead to
match similar codepaths in this file.
Suggested-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/2a796830-de2d-4030-b480-d673f6cc5d94@eisentraut.org
When copying the string strncpy won't add nul termination since
the string length is equal to the length specified. Explicitly
set a nul terminator after copying to properly terminate. Found
via post-commit review.
Author: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CAH2L28vt16C9xTuK+K7QZvtA3kCNWXOEiT=gEekUw3Xxp9LVQw@mail.gmail.com
This reverts commit 38da053463, which
attempted to preserve our ability to start with only 60 semaphores.
Subsequent changes (particularly 55b454d0e) have put that idea pretty
much permanently out of reach: people wishing to use Postgres v18 on
OpenBSD or NetBSD will have no choice but to increase those platforms'
default values of SEMMNI and SEMMNS.
Hence, revert 38da05346's changes in SEMAS_PER_SET and the minimum
tested value of max_connections. Adjust a comment from the subsequent
patch 6d0154196, and tweak the wording in runtime.sgml to make it
clear that changing SEMMNI/SEMMNS is no longer even a little bit
optional on these platforms.
Although 38da05346 was later back-patched into v17, leave that branch
alone: it's still capable of starting with 60 semaphores, and there's
no reason to break that.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/E1tuZNv-0037Gs-34@gemulon.postgresql.org
Discussion: https://postgr.es/m/1052019.1745947915@sss.pgh.pa.us
This commit fixes two bug in ChangeVarNodes_walker() function.
* When considering RestrictInfo, walk down to its clauses based on the
presense of relid to be deleted not just in clause_relids but also in
required_relids.
* Incrementally adjust num_base_rels based on the change of clause_relids
instead of recalculating it using clause_relids, which could contain
outer-join relids.
Reported-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
The slot synchronization skips updating the confirmed_flush LSN of the
local slot if the local slot has a newer catalog_xmin or restart_lsn, but
still allows updating the two_phase and two_phase_at fields of the slot.
This opens up a window for the prepared transactions between old
confirmed_flush LSN and two_phase_at to unexpectedly get decoded and sent
to the downstream after promotion. Then, while decoding the commit
prepared the assert will fail, which expects that the prepare hasn't been
sent to the downstream.
The fix is to skip updating the other slot fields when we are skipping to
update the confirmed_flush LSN of the slot.
We didn't backpatch this commit as two_phase_at was not synced in back
branches, which means prepared transactions won't be unexpectedly sent to
downstream.
We discovered this problem while analyzing BF failure reported in the
discussion link.
Reliably reproducing this issue without a debugger is difficult. Given
its rarity, adding specific injection point to test it doesn't seem
worthwhile, so we won't be adding a dedicated test case.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716B44052000EB91EFAE60E94BC2@OS0PR01MB5716.jpnprd01.prod.outlook.com
Index vacuuming and [auto]prewarm AIO concurrency should be governed by
maintenance_io_concurrency. As such, pass those read stream users the
READ_STREAM_MAINTENANCE flag which will calculate their read stream
distance with maintenance_io_concurrency instead of
effective_io_concurrency. This was an oversight in the original commits
making those operations use the read stream API.
Discussion: https://postgr.es/m/flat/CAAKRu_aopDxTo4b41Mt_7Zc-z0_ngocrY8SFCCY6Aph1HgwuNw%40mail.gmail.com
Checking if another primitive scan is required after all once the next
leaf page was moved from _bt_checkkeys to its _bt_readpage caller by
commit 9a2e2a28. Update a comment that incorrectly described the
recheck mechanism as something that takes place in _bt_checkkeys.
Also fix an older typo in related code comments.
_bt_check_compare neglected to handle a case that can arise when the
scan's keys are temporarily treated as nonrequired, as an optimization:
whenever a NULL tuple value was encountered that had a skip array whose
current element wasn't already NULL, _bt_check_compare failed to advance
the array to the NULL element. This allowed _bt_check_compare to fail
to return matching tuples containing a NULL value (though only with an
array column that came before a skip array column with NULLs, and only
during _bt_readpage calls that set pstate.forcenonrequired=true on a
page where the higher-order column also had to advance).
To fix, teach _bt_check_compare to handle this case just like any other
case where a skip array key is unsatisfied and must be advanced directly
(due to the key being considered a nonrequired key).
Oversight in commit 8a510275, which optimized nbtree search scan key
comparisons with skip arrays.
Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://postgr.es/m/CAHgHdKtLFWZcjr87hMH0hYDHgcifu4Tj7iHz-xh8qsJREt5cqA@mail.gmail.com
During logical decoding, we advance catalog_xmin of logical too early in
fast_forward mode, resulting in required catalog data being removed by
vacuum. This mode is normally used to advance the slot without processing
the changes, but we still can't let the slot's xmin to advance to an
incorrect value.
Commit f49a80c481 fixed a similar issue where the logical slot's
catalog_xmin was getting advanced prematurely during non-fast-forward
mode. During xl_running_xacts processing, instead of directly advancing
the slot's xmin to the oldest running xid in the record, it allowed the
xmin to be held back for snapshots that can be used for
not-yet-replayed transactions, as those might consider older txns as
running too. However, it missed the fact that the same problem can happen
during fast_forward mode decoding, as we won't build a base snapshot in
that mode, and the future call to get_changes from the same slot can miss
seeing the required catalog changes leading to incorrect reslts.
This commit allows building the base snapshot even in fast_forward mode to
prevent the early advancement of xmin.
Reported-by: Amit Kapila <amit.kapila16@gmail.com>
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 13
Discussion: https://postgr.es/m/CAA4eK1LqWncUOqKijiafe+Ypt1gQAQRjctKLMY953J79xDBgAg@mail.gmail.com
Discussion: https://postgr.es/m/OS0PR01MB57163087F86621D44D9A72BF94BB2@OS0PR01MB5716.jpnprd01.prod.outlook.com
wait_event_types.h is generated by the code, and included wait_event.h.
wait_event.h did the opposite move, including wait_event_types.h,
causing a circular dependency between both.
wait_event_types.h only needs to now about the wait event classes, so
this information is moved into its own file, and wait_event_types.h uses
this new header so as it does not depend anymore on wait_event.h.
Note that such errors can be found with clang-tidy, with commands like
this one:
clang-tidy source_file.c --checks=misc-header-include-cycle -- \
-I/install/path/include/ -I/install/path/include/server/
Issue introduced by fa88928470.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/350192.1745768770@sss.pgh.pa.us
fc069a3a63 implements Self-Join Elimination (SJE), which can remove base
relations when appropriate. However, regressions tests for SJE only cover
the case when placeholder variables (PHVs) are evaluated and needed only
in a single base rel. If this baserel is removed due to SJE, its clauses,
including PHVs, will be transferred to the keeping relation. Removing these
PHVs may trigger an error on plan creation -- thanks to the b3ff6c742f for
detecting that.
This commit skips removal of PHVs during SJE. This might also happen that
we skip the removal of some PHVs that could be removed. However, the overhead
of extra PHVs is small compared to the complexity of analysis needed to remove
them.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Alena Rybakina <a.rybakina@postgrespro.ru>
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
This cleans up some loose ends left by commit e8ca9ed1d. I hadn't
looked closely enough at these places before, but now I have.
The use of double-quoted #includes for Perl headers in plperl_system.h
seems to be simply a mistake introduced in 6c944bf3c and faithfully
copied forward since then. (I had thought possibly it was required
by some weird Windows build setup, but there's no evidence of that in
our history.)
The occurrences in SectionMemoryManager.h and SectionMemoryManager.cpp
evidently stem from those files' origin as LLVM code. It's
understandable that LLVM would treat their own files as needing
double-quoted #includes; but they're still system headers to us.
I also applied the same check to *.c files, and found a few other
random incorrect usages in both directions.
Our ECPG headers and test files routinely use angle brackets to refer
to ECPG headers. I left those usages alone, since it seems reasonable
for an ECPG user to regard those headers as system headers.
c4d5cb71d2 adjusted the fast-path locking code to allow some
configuration of the number of fast-path locking slots via the
max_locks_per_transaction GUC. In that commit the FAST_PATH_REL_GROUP()
macro used integer division to determine the fast-path locking group slot
to use for the lock.
The divisor in this case is always a power-of-two value. Here we swap
out the divide by a bitwise-AND, which is a significantly faster
operation to perform.
In passing, adjust the code that's setting FastPathLockGroupsPerBackend
so that it's more clear that the value being set is a power-of-two.
Also, adjust some comments in the area which contained some magic
numbers. It seems better to justify the 1024 upper limit in the
location where the #define is made instead of where it is used.
Author: David Rowley <drowleyml@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAApHDvodr3bcnpxcs7+k-3cFwYR0tP-BYhyd2PpDhe-bCx9i=g@mail.gmail.com
10f6646847 intended to limit the value of io_combine_limit to the minimum of
io_combine_limit and io_max_combine_limit. To avoid issues with interdependent
GUCs, it introduced io_combine_limit_guc and set io_combine_limit in assign
hooks. That plan was thwarted by guc_tables.c accidentally still referencing
io_combine_limit, instead of io_combine_limit_guc. That lead to the GUC
machinery overriding the work done in the assign hooks, potentially leaving
io_combine_limit with a too high value.
The consequence of this bug was that when running with io_combine_limit >
io_combine_limit_guc the AIO machinery would not have reserved large enough
iovec and IO data arrays, with one IO's arrays overlapping with another IO's,
leading to total confusion.
To make such a problem easier to detect in the future, add assertions to
pgaio_io_set_handle_data_* checking the length is smaller than
io_max_combine_limit (not just PG_IOV_MAX).
It'd be nice to have a few tests for this, but it's not entirely obvious how
to do so portably.
As remarked upon by Tom, the GUC assignment hooks really shouldn't set the
underlying variable, that's the job of the GUC machinery. Change that as well.
Discussion: https://postgr.es/m/c5jyqnuwrpigd35qe7xdypxsisdjrdba5iw63mhcse4mzjogxo@qdjpv22z763f
pgaio_io_reclaim() reset the fields in PgAioHandle before updating the state
to IDLE or incrementing the generation. For most things that's OK, but for
pg_get_aios() it is not - if it copied the PgAioHandle while fields were being
reset, we wouldn't detect that and could call
pgaio_io_get_target_description() with ioh->target == PGAIO_TID_INVALID,
leading to a crash.
Fix this issue by incrementing the generation and state earlier, before
resetting.
Also add an assertion to pgaio_io_get_target_description() for the target to
be valid - that'd have made this case a bit easier to debug. While at it,
add/update a few related assertions.
Author: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/062daca9-dfad-4750-9da8-b13388301ad9@gmail.com
Not having this check would produce a core dump at startup when running
pgstat_read_statsfile(), in the case where the information of a stats
kind for an entry in the dshash could not be found. The same check
already happens for fixed-numbered stats and entries that are stored
with their names. This issue can be seen with custom stats kinds.
Note that this problem can be reproduced what what is in the core code:
- Tweak the test module injection_points to not load the fixed-numbered
stats part, leaving only the variable-numbered stats.
- Create an instance with injection_points defined in
shared_preload_libraries.
- Create a pgstats entry by attaching and running a point.
- Restart the server without shared_preload_libraries. The startup
process detects that something is wrong and reports a WARNING.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aAieZAvM+K1d89R2@ip-10-97-1-34.eu-west-3.compute.internal
One place in hash_create() used DynaHashAlloc() as a convenient
shorthand for MemoryContextAlloc(). That was fine when it was
written, but it stopped being fine when 9c911ec06 changed
DynaHashAlloc() to use MCXT_ALLOC_NO_OOM (mea culpa). Change
the code to call plain MemoryContextAlloc() as intended.
I think that this bug may be unreachable in practice, since we now
always create AllocSets with some space already allocated, so that
an OOM failure here for a non-shared hash table should be impossible
(with a hash table name of reasonable length anyway). And there
aren't enough shared hash tables to make a crash for one of those
probable. Nonetheless it's clearly not operating as designed, so
back-patch to v16 where 9c911ec06 came in.
Reported-by: Maksim Korotkov <m.korotkov@postgrespro.ru>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/219bdccd460510efaccf90b57e5e5ef2@postgrespro.ru
Backpatch-through: 16
b85a9d046e introduced a new RelIdToTypeIdCacheHash, whose entries should
exist for typecache entries with TCFLAGS_HAVE_PG_TYPE_DATA flag set or any
of TCFLAGS_OPERATOR_FLAGS set or tupDesc set. However, TypeCacheOpcCallback(),
which resets TCFLAGS_OPERATOR_FLAGS, was forgotten to update
RelIdToTypeIdCacheHash.
This commit adds a delete_rel_type_cache_if_needed() call to the
TypeCacheOpcCallback() function to maintain RelIdToTypeIdCacheHash after
resetting TCFLAGS_OPERATOR_FLAGS.
Also, this commit fixes the name of the delete_rel_type_cache_if_needed()
function in its mentions in the comments.
Reported-by: Noah Misch
Discussion: https://postgr.es/m/20250411203241.e9.nmisch%40google.com
To estimate with extended statistics, we need to clear the varnullingrels
field in the expression, and duplicates are not allowed in the GroupVarInfo
list. We might re-use add_unique_group_var(), but we don't do so for two
reasons.
1) We must keep the origin_rinfos list ordered exactly the same way as
varinfos.
2) add_unique_group_var() is designed for estimate_num_groups(), where a
larger number of groups is worse. While estimating the number of hash
buckets, we have the opposite: a lesser number of groups is worse.
Therefore, we don't have to remove "known equal" vars: the removed var
may valuably contribute to the multivariate statistics to grow the number
of groups.
This commit adds custom code to estimate_multivariate_bucketsize() to
initialize varinfos properly.
Reported-by: Robins Tharakan <tharakan@gmail.com>
Discussion: https://postgr.es/m/18885-da51324078588253%40postgresql.org
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
When a foreign key constraint is placed on a partitioned table, we
actually make two pg_constraint entries associated with that table.
(I have my doubts about the wisdom of that, but it's been like that
since v12 and post-feature-freeze is no time to be messing with such
entrenched decisions.) The second "child" entry always had a name
generated according to the default rule, "table_column(s)_fkey[nnn]",
even if the primary entry had an unrelated user-specified name. The
trouble with doing that is that the default name could collide with
the user-specified name of some other constraint on the same table.
While we were willing to adjust the generated name to avoid
collisions, that only helps if it's made second; if it's made first
then creation of the other constraint would fail, potentially causing
dump/reload or pg_upgrade failures.
The core of the problem here is that we're infringing on user
namespace, so I doubt that there's any 100% solution other than to
find a way to not need the "child" entry. In the meantime, it seems
like it'd be an improvement to make the child's name be the name of
the parent constraint with an underscore and digit(s) appended as
necessary to make it unique. This rule can in theory fail in the same
way, but it seems much less probable; for one thing, this rule is
guaranteed not to match primary entries having auto-generated names.
(While an auto-generated primary name isn't user-specified to begin
with, it acts like that during dump/reload, so collisions against such
names are definitely possible.)
An additional bonus, visible in some of the regression test cases
that change here, arises from the fact that some error messages
cite the child constraint's name not the parent's. In the
previous approach the two names could be completely unrelated,
leading to user confusion --- the more so since psql's \d command
hides child constraints. With this approach it's hopefully much
clearer which constraint-the-user-knows-about is failing.
However, that does mean that there's user-visible behavior change
occurring here, making it seem like not something to back-patch.
I feel it's not too late for v18, though.
Reported-by: Kirill Reshke <reshkekirill@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Alvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/CALdSSPhGitjpTfzEMJN-Y2x+Q-5QChSxAsmSJ1-E8mQJLkHOqQ@mail.gmail.com
Commit 3f28b2fcac tried to ensure that the replication origin shouldn't be
advanced in case of an ERROR in the apply worker, so that it can request
the same data again after restart. However, it is possible that an ERROR
was caught and handled by a (say PL/pgSQL) function, and the apply worker
continues to apply further changes, in which case, we shouldn't reset the
replication origin.
Ensure to reset the origin only when the apply worker exits after an
ERROR.
Commit 3f28b2fcac added new function geterrlevel, which we removed in HEAD
as part of this commit, but kept it in backbranches to avoid breaking any
applications. A separate case can be made to have such a function even for
HEAD.
Reported-by: Shawn McCoy <shawn.the.mccoy@gmail.com>
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 16, where it was introduced
Discussion: https://postgr.es/m/CALsgZNCGARa2mcYNVTSj9uoPcJo-tPuWUGECReKpNgTpo31_Pw@mail.gmail.com
This assertion, based on pending_since (timestamp used to prevent stats
reports to be too frequent or should a partial flush happen), is reached
when it is found that no data can be flushed but a previous call of
pgstat_report_stat() determined that some stats data has been found as
in need of a flush. So pending_since is set when some stats data is
pending (in non-force mode) or if report attempts are too frequent, and
reset to 0 once all stats have been flushed.
Since 5cbbe70a9c, WAL senders have begun to report their stats on a
periodic basis for IO stats in v16~ and backend stats on HEAD, creating
some friction with the concurrent pgstat_report_stat() calls that can
happen in the context of a WAL sender (shutdown callback doing a final
report or backend-related code paths). This problem is the cause of
spurious failures in the TAP tests.
In theory, this assertion can be also reached in v15, even if that's
very unlikely. For example, a process, say a background worker, could
do periodic and direct stats flushes with concurrent calls of
pgstat_report_stat() that could cause conflicting values of
pending_since. This can be done with WAL or SLRU stats flushes using
pgstat_flush_wal() or pgstat_slru_flush(). HEAD makes this situation
easier to happen with custom cumulative stats.
This commit removes the assertion altogether, per discussion, as it is
more useful to keep the state of things as they are for the WAL sender.
The assertion could use a special state based on for example
am_walsender, but I doubt that this would be meaningful in the long run
based on the other arguments raised while discussing this issue.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/1489124.1744685908@sss.pgh.pa.us
Discussion: https://postgr.es/m/dwrkeszz6czvtkxzr5mqlciy652zau5qqnm3cp5f3p2po74ppk@omg4g3cc6dgq
Backpatch-through: 15
This error message was 'runaway "struct_name"', which isn't all
that clear; I think 'could not find closing brace for "struct_name"'
is better. Also, provide the location of the struct start using the
script's usual '$file:$lineno' style.
Bug: #18901
Reported-by: Clemens Ruck <clemens.ruck@t-online.de>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18901-424272abe01357e6@postgresql.org
This injection point was named "AtEOXact_Inval-with-transInvalInfo", not
respecting the implied naming convention that injection points should
use lower-case characters, with terms separated by dashes. All the
other points defined in the tree follow this style, so let's be more
consistent.
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Aleksander Alekseev <aleksander@timescale.com>
Discussion: https://postgr.es/m/OSCPR01MB14966E14C1378DEE51FB7B7C5F5B32@OSCPR01MB14966.jpnprd01.prod.outlook.com
Backpatch-through: 17
Word boundaries are based on whether a character is alphanumeric or
not. For the PG_UNICODE_FAST collation, alphanumeric includes
non-ASCII digits; whereas for the PG_C_UTF8 collation, it only
includes digits 0-9. Pass down the right information from the
pg_locale_t into initcap_wbnext to differentiate the behavior.
Reported-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250417135841.33.nmisch@google.com
exec_replication_command created a cmd_context to work in and
then deleted it on exit. This is pretty dangerous because
some replication commands start/finish transactions. In the
wake of commit 1afe31f03, that could lead to re-selecting a
CurrentMemoryContext that's already been deleted, leading to
hilarity such as a memory context that is its own parent.
To fix, let's make the cmd_context persist across
exec_replication_command calls; instead of deleting it, we'll just
reset it each time. In this way it retains the same identity and
there's no problem if transaction abort restores it as the working
context. It probably even saves a few microseconds to do this.
This fix also ensures that exec_replication_command returns to the
caller (PostgresMain) with the same context active that had been
when it was called (probably MessageContext). The previous
coding could get that wrong too.
Reported-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAO6_XqoJA7-_G6t7Uqe5nWF3nj+QBGn4F6Ptp=rUGDr0zo+KvA@mail.gmail.com
The case of "node == parent" might seem impossible, since we just
allocated the new node. But it's possible if parent is a dangling
reference to a recently-deleted context. In fact, given aset.c's
habit of recycling contexts, it's actually rather likely if that's so.
If we'd had this assertion before, it would have simplified debugging
a recently-identified walsender issue.
Reported-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAO6_XqoJA7-_G6t7Uqe5nWF3nj+QBGn4F6Ptp=rUGDr0zo+KvA@mail.gmail.com
Blocking checkpoint phase 2 requires MarkBufferDirty() and
BUFFER_LOCK_EXCLUSIVE; neither suffices by itself. transam/README documents
this, citing SyncOneBuffer(). Update the DELAY_CHKPT_START documentation to
say this. Expand the heap_inplace_update_and_unlock() comment that cites
XLogSaveBufferForHint() as precedent, since heap_inplace_update_and_unlock()
could have opted not to use DELAY_CHKPT_START.
Commit 8e7e672cda added DELAY_CHKPT_START to
heap_inplace_update_and_unlock(). Since commit
bc6bad8857 reverted it in non-master branches,
no back-patch.
Discussion: https://postgr.es/m/20250406180054.26.nmisch@google.com
Commit 7102070329 fixed a similar bug, but
it missed the case of database-wide ANALYZE ("use_own_xacts" mode).
Commit a07e03fd8f changed consequences
from silent discard of a pg_class stats (relpages et al.) update to
ERROR "tuple to be updated was already modified". Losing a relpages
update of an ON COMMIT DELETE ROWS table was negligible, but a
COMMIT-time error isn't negligible. Back-patch to v13 (all supported
versions).
Reported-by: Richard Guo <guofenglinux@gmail.com
Reported-by: Robins Tharakan <tharakan@gmail.com>
Discussion: https://postgr.es/m/CAMbWs4-XwMKMKJ_GT=p3_-_=j9rQSEs1FbDFUnW9zHuKPsPNEQ@mail.gmail.com
Backpatch-through: 13
1349d2790 added support so that aggregate functions with an ORDER BY or
DISTINCT clause could make use of presorted inputs to avoid an implicit
sort within nodeAgg.c. That commit failed to consider that a FILTER
clause may exist that filters rows before the aggregate function
arguments are evaluated. That can be problematic if an aggregate
argument contains an expression which could error out during evaluation.
It's perfectly valid to want to have a FILTER clause which eliminates
such values, and with the pre-sorted path added in 1349d2790, it was
possible that the planner would produce a plan with a Sort node above
the Aggregate to perform the sort on the aggregate's arguments long before
the Aggregate node would filter out the non-matching values.
Here we fix this by inspecting ORDER BY / DISTINCT aggregate functions
which have a FILTER clause to see if the aggregate's arguments are
anything more complex than a Var or a Const. Evaluating these isn't
going to cause an error. If we find any non-Var, non-Const parameters
then the planner will now opt to perform the sort in the Aggregate node
for these aggregates, i.e. disable the presorted aggregate optimization.
An alternative fix would have been to completely disallow the presorted
optimization for Aggrefs with any FILTER clause, but that wasn't done as
that could cause large performance regressions for queries that see
significant gains from 1349d2790 due to presorted results coming in from
an Index Scan.
Backpatch to 16, where 1349d2790 was introduced
Author: David Rowley <dgrowleyml@gmail.com>
Reported-by: Kaimeh <kkaimeh@gmail.com>
Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAK-%2BJz9J%3DQ06-M7cDJoPNeYbz5EZDqkjQbJnmRyQyzkbRGsYkA%40mail.gmail.com
Backpatch-through: 16
The format of the injection point names used by the AIO code does not
match the existing naming convention used everywhere else in the code,
so let's be consistent. These points are used in test_aio.
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Discussion: https://postgr.es/m/Z_yTB80bdu1sYDqJ@paquier.xyz
Both pg_get_process_memory_contexts() and pg_backend_memory_contexts
have 1-based levels, whereas pg_log_backend_memory_contexts() was using
0-based levels. Align these.
This results in slightly saner behavior from MemoryContextStatsDetail()
in regards to the max_level. Previously it would stop at 1 level before
the maximum requested level rather than at that level.
Reported-by: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Author: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Author: David Rowley <drowleyml@gmail.com
Reviewed-by: Melih Mutlu <m.melihmutlu@gmail.com>
Reviewed-by: Rahila Syed <rahilasyed90@gmail.com>
Discussion: https://postgr.es/m/395ea5d4fe190480efa95bf533485c70@oss.nttdata.com
The "children" list won't be used until "got_children" has been set
true, but older compilers don't get that; about half a dozen
buildfarm animals are warning about this. Issue added by 11ff192b5.
While here, improve slightly-shaky grammar in comment.
Discussion: https://postgr.es/m/2057835.1744833309@sss.pgh.pa.us
This gets rid of repetitive get_typlen calls in postquel_sub_params,
which show up as costing a few percent of the runtime in simple test
cases (more with more parameters).
In combination with the preceding patches, this gets us most of the
way back down to the amount of per-call overhead that functions.c
had before commit 0dca5d68d. There are some more things that could
be done, but this seems like an okay place to stop for v18.
At this point, the only data structures we allocate directly in
fcontext are the SQLFunctionCache struct itself, the ParamListInfo
struct, and the execution_state array, all of which are small and
perfectly capable of being re-used across executions of the same
FmgrInfo. Hence, let's give them the same lifespan as the FmgrInfo.
This step gets rid of the separate SQLFunctionLink struct and makes
fn_extra point to SQLFunctionCache again. We also get rid of the
separate fcontext memory context and allocate these items directly
in fn_mcxt.
For notational simplicity, SQLFunctionCache still has an fcontext
field, but it's just a copy of fn_mcxt.
The motivation for this is to allow these structures to live as
long as the FmgrInfo and be re-used across calls, restoring the
original design without its propensity for memory leaks. This
gets rid of some per-call overhead that we added in 0dca5d68d.
We also make an effort to re-use the JunkFilter and result slot.
Those might need to change if the function definition changes,
so we compromise by rebuilding them if the cached plan changes.
This also moves the tuplestore into fn_mcxt so that it can be
re-used across calls, again undoing a change made in 0dca5d68d.
Put the JunkFilter and its result slot (and thence also
some subsidiary data such as the result tupledesc) into a
separate subcontext "jfcontext". This doesn't accomplish
a lot at this point, because we make a new JunkFilter each
time through the SQL function. However, the plan is to make
the fcontext long-lived, and that raises the possibility
that we'll need a new JunkFilter because the plan for the
result-generating query changes. A separate context makes
it easy to free the obsoleted data when that happens.
Also, instead of always running the sub-executor in fcontext,
make a separate context for it if we're doing lazy eval of
a SRF, and otherwise just run it inside CurrentMemoryContext.
Previously, much of this code ran with CurrentMemoryContext set
to be the function's fcontext, so that we tended to leak a lot of
stuff there. Commit 0dca5d68d dealt with that by releasing the
fcontext at the completion of each SQL function call, but we'd
like to go back to the previous approach of allowing the fcontext
to be query-lifespan. To control the leakage problem, rearrange
the code so that we mostly run in the memory context that fmgr_sql
is called in (which we expect to be short-lived). Notably, this
means that parsing/planning is all done in the short-lived context
and doesn't leak cruft into fcontext.
This patch also fixes the allocation of execution_state records
so that we don't leak them across executions. I set that up
with a re-usable array that contains at least as many
execution_state structs as we need for the current querytree.
The chain structure is still there, but it's not really doing
much for us, and maybe somebody will be motivated to get rid
of it. I'm not though.
This incidentally also moves the call of BlessTupleDesc to be
with the code that creates the JunkFilter. That doesn't make
much difference now, but a later patch will reduce the number
of times the JunkFilter gets made, and we needn't bless the
results any more often than that.
We still leak a fair amount in fcontext, particularly when
executing utility statements, but that's material for a
separate patch step; the point here is only to get rid of
unintentional allocations in fcontext.
Late in the development of commit 0dca5d68d, I added a step to copy
the result tlist we extract from the cached final query, because
I was afraid that that might not last as long as the JunkFilter that
we're passing it off to. However, that turns out to cost a noticeable
number of cycles, and it's really quite unnecessary because the
JunkFilter will not examine that tlist after it's been created.
(ExecFindJunkAttribute would use it, but we don't use that function
on this JunkFilter.) Hence, remove the copy step. For safety,
reset the might-become-dangling jf_targetList pointer to NIL.
In passing, remove DR_sqlfunction.cxt, which we don't use anymore;
it's confusing because it's not entirely clear which context it
ought to point at.
Commit 0bada39c83 fixed a bug of this kind,
which existed in all branches for six days before detection. While the
probability of reaching the trouble was low, the disruption was extreme. No
new backends could start, and service restoration needed an immediate
shutdown. Hence, add this to catch the next bug like it.
The new check in RelationIdGetRelation() suffices to make autovacuum detect
the bug in commit 243e9b40f1 that led to commit
0bada39. This also checks in a number of similar places. It replaces each
Assert(IsTransactionState()) that pertained to a conditional catalog read.
No back-patch for now, but a back-patch of commit 243e9b4 should back-patch
this, too. A back-patch could omit the src/test/regress changes, since back
branches won't gain new index columns.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/20250410191830.0e.nmisch@google.com
Discussion: https://postgr.es/m/10ec0bc3-5933-1189-6bb8-5dec4114558e@gmail.com
estimate_multivariate_ndistinct() is coded to assume the caller handles
passing it a list of GroupVarInfos with unique 'var' fields over the
entire list. 6bb6a62f3 added code which didn't ensure this and that
could result in estimate_multivariate_ndistinct() erroring out with:
ERROR: corrupt MVNDistinct entry
This occurred because estimate_multivariate_ndistinct() first searches
for a set of stats that match to at least two of the given GroupVarInfos
and then later assumes that the MVNDistinctItem.items array of the
best matching stats will have an entry for those two columns. If the
GroupVarInfos List contained a duplicate entry then the same column could
be matched to twice and that could trick the code into thinking we have
>= 2 columns matched in cases where only a single distinct column has been
matched. This could result in a failure to find the correct
MVNDistinctItem in the stats as the array containing those never
contains an item for single columns.
Here we make it more clear that the function needs a distinct set of
GroupVarInfos and also tidy up a few other comments to make things a bit
easier to follow.
Author: David Rowley <drowleyml@gmail.com>
Discussion: https://postgr.es/m/CAApHDvocZCUhM9W9mJ39d6oQz7ePKoqFnao_347mvC-A7QatcQ@mail.gmail.com
Buildfarm member drongo complained because the definitions of these
functions used "const Oid foo" where the forward declarations just
had "Oid foo". (I'm a bit surprised that drongo seems to be the only
complainant.) I chose to fix this by removing the "consts" because
(a) I'm generally not a fan of using const that way, and (b) it was
a minority usage even within these two functions, let alone compared
to the rest of our code base.
Oversight in commit eec0040c4, so no need for back-patch.
We were unnecessarily acquiring AccessExclusiveLock on all child tables
when "ALTER TABLE ONLY sometab ADD PRIMARY KEY" was run on their parent
table, an oversight in commit 14e87ffa5c. This caused deadlocks
during pg_restore of partitioned tables.
The reason to acquire the AEL was that we need to verify that child
tables have the involved columns already marked as not-null; but if the
parent table has an inheritable not-null constraint, then all children
must necessarily be in the correct state already, so we can skip the
check, which avoids acquiring the lock. Reorder the code so that it
works that way. This doesn't change things in the case where the
constraint doesn't exist, but that case is of lesser importance because
it doesn't occur during parallel pg_restore.
While at it, reword some errmsg() and add errhint() to similar cases in
related but not adjacent code.
Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/67469c1c-38bc-7d94-918a-67033f5dd731@gmx.net
Discussion: https://postgr.es/m/2045026.1743801143@sss.pgh.pa.us
Discussion: https://postgr.es/m/1280408.1744650810@sss.pgh.pa.us
Memoize typically marks cache entries as complete after fully scanning
the inner side of a join. However, in the case of unique joins, we
skip to the next outer tuple as soon as the first matching inner tuple
is found, leaving no opportunity to scan the inner side to completion.
To work around that, we mark cache entries as complete after fetching
the first matching inner tuple in unique joins.
This approach is only safe when all of the join's restriction clauses
are parameterized; otherwise, there is no guarantee that reading just
one tuple from the inner side is sufficient.
Currently, we check for this by verifying that the number of clauses
in ppi_clauses is no less than the number of the join's restriction
clauses. However, this check isn't entirely reliable, as ppi_clauses
includes join clauses available from all outer rels, not just the
current outer rel. This means the check could pass even if a
restriction clause isn't parameterized, as long as another join
clause, which doesn't belong to the current join, is included in
ppi_clauses.
To fix this, we explicitly check whether each restriction clause of
the current join is present in ppi_clauses.
While we're here, remove the XXX comment from the modified code, as
it's not justified; in certain cases, it's not possible to move a join
clause to the inner side.
This is arguably a bugfix, but no backpatch given the lack of field
reports.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: wenhui qiu <qiuwenhuifx@gmail.com>
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Discussion: https://postgr.es/m/CAMbWs4-8JPouj=wBDj4DhK-WO4+Xdx=A2jbjvvyyTBQneJ1=BQ@mail.gmail.com
If a GENERATED column is declared to have a domain data type where
the domain's constraints disallow null values, INSERT commands failed
because we built a targetlist that included coercing a null constant
to the domain's type. The failure occurred even when the generated
value would have been perfectly OK. This is adjacent to the issues
fixed in 0da39aa76, but we didn't notice for lack of testing a domain
with such a constraint.
We aren't going to use the result of the targetlist entry for the
generated column --- ExecComputeStoredGenerated will overwrite it.
So it's not really necessary that it have the exact datatype of
the generated column. This patch fixes the problem by changing
the targetlist entry to be a null Const of the domain's base type,
which should be sufficiently legal. (We do have to tweak
ExecCheckPlanOutput to accept the situation, though.)
This has been broken since we implemented generated columns.
However, this patch only applies easily as far back as v14, partly
because I (tgl) only carried 0da39aa76 back that far, but mostly
because v14 significantly refactored the handling of INSERT/UPDATE
targetlists. Given the lack of field complaints and the short
remaining support lifetime of v13, I judge the cost-benefit ratio
not good for devising a version that would work in v13.
Reported-by: jian he <jian.universality@gmail.com>
Author: jian he <jian.universality@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CACJufxG59tip2+9h=rEv-ykOFjt0cbsPVchhi0RTij8bABBA0Q@mail.gmail.com
Backpatch-through: 14
Commit 0f21db36d made an assumption that GIN triConsistentFns
would not modify their input entryRes[] arrays. But in fact,
the "shim" triConsistentFn that we use for opclasses that don't
supply their own did exactly that, potentially leading to wrong
answers from a GIN index search. Through bad luck, none of the
test cases that we have for such opclasses exposed the bug.
One response to this could be that the assumption of consistency check
functions not modifying entryRes[] arrays is a bad one, but it still
seems reasonable to me. Notably, shimTriConsistentFn is itself
assuming that with respect to the underlying boolean consistentFn,
so it's sure being self-centered in supposing that it gets to do so.
Fortunately, it's quite simple to fix shimTriConsistentFn to restore
the entry-time state of entryRes[], so let's do that instead.
This issue doesn't affect any core GIN opclasses, since they all
supply their own triConsistentFns. It does affect contrib modules
btree_gin, hstore, and intarray.
Along the way, I (tgl) noticed that shimTriConsistentFn failed to
pick up on a "recheck" flag returned by its first call to the boolean
consistentFn. This may be only a latent problem, since it would be
unlikely for a consistentFn to set recheck for the all-false case
and not any other cases. (Indeed, none of our contrib modules do
that.) Nonetheless, it's formally wrong.
Reported-by: Vinod Sridharan <vsridh90@gmail.com>
Author: Vinod Sridharan <vsridh90@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFMdLD7XzsXfi1+DpTqTgrD8XU0i2C99KuF=5VHLWjx4C1pkcg@mail.gmail.com
Backpatch-through: 13
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in a few places. These
inconsistencies were all introduced during Postgres 18 development.
This commit was written with help from clang-tidy, by mechanically
applying the same rules as similar clean-up commits (the earliest such
commit was commit 035ce1fe).
synchronous_standby_names cannot be reloaded safely by backends, and the
checkpointer is in charge of updating a state in shared memory if the
GUC is enabled in WalSndCtl, to let the backends know if they should
wait or not for a given LSN. This provides a strict control on the
timing of the waiting queues if the GUC is enabled or disabled, then
reloaded. The checkpointer is also in charge of waking up the backends
that could be waiting for a LSN when the GUC is disabled.
This logic had a race condition at startup, where it would be possible
for backends to not wait for a LSN even if synchronous_standby_names is
enabled. This would cause visibility issues with transactions that we
should be waiting for but they were not. The problem lasts until the
checkpointer does its initial update of the shared memory state when it
loads synchronous_standby_names.
In order to take care of this problem, the shared memory state in
WalSndCtl is extended to detect if it has been initialized by the
checkpointer, and not only check if synchronous_standby_names is
defined. In WalSndCtlData, sync_standbys_defined is renamed to
sync_standbys_status, a bits8 able to know about two states:
- If the shared memory state has been initialized. This flag is set by
the checkpointer at startup once, and never removed.
- If synchronous_standby_names is known as defined in the shared memory
state. This is the same as the previous sync_standbys_defined in
WalSndCtl.
This method gives a way for backends to decide what they should do until
the shared memory area is initialized, and they now ultimately fall back
to a check on the GUC value in this case, which is the best thing that
can be done.
Fortunately, SyncRepUpdateSyncStandbysDefined() is called immediately by
the checkpointer when this process starts, so the window is very narrow.
It is possible to enlarge the problematic window by making the
checkpointer wait at the beginning of SyncRepUpdateSyncStandbysDefined()
with a hardcoded sleep for example, and doing so has showed that a 2PC
visibility test is indeed failing. On machines slow enough, this bug
would cause spurious failures.
In 17~, we have looked at the possibility of adding an injection point
to have a reproducible test, but as the problematic window happens at
early startup, we would need to invent a way to make an injection point
optionally persistent across restarts when attached, something that
would be fine for this case as it would involve the checkpointer. This
issue is quite old, and can be reproduced on all the stable branches.
Author: Melnikov Maksim <m.melnikov@postgrespro.ru>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/163fcbec-900b-4b07-beaa-d2ead8634bec@postgrespro.ru
Backpatch-through: 13
Sami complained that there's a discrepancy between n_mod_since_analyze
and n_ins_since_vacuum, as the former only accounts for committed changes
and the latter tracks committed and aborted inserts. Nobody seemed
overly concerned that this would cause any concerning issues. The
repercussions, from what I can tell, are limited to causing an
autovacuum to trigger for inserts sooner than it otherwise might. For
typical ratios of commits to aborts, it's unlikely to ever be noticed.
Fixing things to make it so n_ins_since_vacuum only displays committed
inserts would require an additional field in PgStat_TableCounts, which
does not quite seem worthwhile at this stage. This commit just adds a
comment with some details to mention that we know about it, which will
hopefully prevent repeat discussions.
Reported-by: Sami Imseih <samimseih@gmail.com>
Author: David Rowley <drowleyml@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/CAApHDvpgV3a-R2EGmPOh0L-x3pHbZpM3y4dySWfy+UqUazwDQA@mail.gmail.com
By inspection, ip_addrsize() can't return a negative result.
(If it could, we'd have way bigger problems elsewhere.)
So delete useless check in network_send(). Most C compilers
are probably perfectly capable of removing this code by
themselves, but it's confusing/misleading.
Bug: #18889
Reported-by: Daniel Elishakov <dan-eli@mail.ru>
Discussion: https://postgr.es/m/18889-73d4f19e953a629e@postgresql.org
Data loss can happen when the DDLs like ALTER PUBLICATION ... ADD TABLE ...
or ALTER TYPE ... that don't take a strong lock on table happens
concurrently to DMLs on the tables involved in the DDL. This happens
because logical decoding doesn't distribute invalidations to concurrent
transactions and those transactions use stale cache data to decode the
changes. The problem becomes bigger because we keep using the stale cache
even after those in-progress transactions are finished and skip the
changes required to be sent to the client.
This commit fixes the issue by distributing invalidation messages from
catalog-modifying transactions to all concurrent in-progress transactions.
This allows the necessary rebuild of the catalog cache when decoding new
changes after concurrent DDL.
We observed performance regression primarily during frequent execution of
*publication DDL* statements that modify the published tables. The
regression is minor or nearly nonexistent for DDLs that do not affect the
published tables or occur infrequently, making this a worthwhile cost to
resolve a longstanding data loss issue.
An alternative approach considered was to take a strong lock on each
affected table during publication modification. However, this would only
address issues related to publication DDLs (but not the ALTER TYPE ...)
and require locking every relation in the database for publications
created as FOR ALL TABLES, which is impractical.
The bug exists in all supported branches, but we are backpatching till 14.
The fix for 13 requires somewhat bigger changes than this fix, so the fix
for that branch is still under discussion.
Reported-by: hubert depesz lubaczewski <depesz@depesz.com>
Reported-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Author: Shlok Kyal <shlok.kyal.oss@gmail.com>
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Tested-by: Benoit Lobréau <benoit.lobreau@dalibo.com>
Backpatch-through: 14
Discussion: https://postgr.es/m/de52b282-1166-1180-45a2-8d8917ca74c6@enterprisedb.com
Discussion: https://postgr.es/m/CAD21AoAenVqiMjpN-PvGHL1N9DWnHSq673bfgr6phmBUzx=kLQ@mail.gmail.com
d69d45a5a changed how em_is_child members are stored in
EquivalenceClasses. Children are no longer stored in the ec_members
list. optimizer/README mentioned that most operations "should ignore
child members", but that felt a little untrue now since child members
are now stored in a separate place, they simply won't be found by the
normal means of looking (a foreach loop over ec_members), and if you don't
find them, there's technically no need to "ignore" them.
Here we tweak the wording slightly to reflect the new storage location
for child members.
Reported-by: Amit Langote <amitlangote09@gmail.com>
Author: Amit Langote <amitlangote09@gmail.com>
Author: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CA+HiwqE8v=EuAP_3F_A2xn8zWx+nG_etW_Fe_DvKO-Fkx=+DdQ@mail.gmail.com
This moves/renames some of the functions defined in pg_numa.c:
* pg_numa_get_pagesize() is renamed to pg_get_shmem_pagesize(), and
moved to src/backend/storage/ipc/shmem.c. The new name better reflects
that the page size is not related to NUMA, and it's specifically about
the page size used for the main shared memory segment.
* move pg_numa_available() to src/backend/storage/ipc/shmem.c, i.e. into
the backend (which more appropriate for functions callable from SQL).
While at it, improve the comment to explain what page size it returns.
* remove unnecessary includes from src/port/pg_numa.c, adding
unnecessary dependencies (src/port should be suitable for frontent).
These were either leftovers or unnecessary thanks to the other changes
in this commit.
This eliminates unnecessary dependencies on backend symbols, which we
don't want in src/port.
Reported-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
https://postgr.es/m/CALdSSPi5fj0a7UG7Fmw2cUD1uWuckU_e8dJ+6x-bJEokcSXzqA@mail.gmail.com
Change MyCancelKeyLength's type from uint8 to int. While it always
fits in a uint8, plain int is less surprising, as there's no
particular reason for it to be uint8.
Fix one ProcSignalInit caller that passed 'false' instead of NULL for
the pointer argument.
Author: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/61be9e31-7b7d-49d5-bc11-721800d89d64@eisentraut.org
These examples fail to account for join clauses generated by
EquivalenceClasses, but since we haven't mentioned EquivalenceClasses
yet it seems like it'd just add confusion to make them fully accurate.
Instead, parenthetically note that they're oversimplified.
Reported-by: Zeyuan Hu <ferrishu3886@gmail.com>
Co-authored-by: David Rowley <dgrowleyml@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CACvHWmYFo+60yMqKJajDDvKN5EM41YHrCT3oxukwXmGAqpWvyw@mail.gmail.com
The issue happens when building conflict information during apply of
INSERT or UPDATE operations that violate unique constraints on leaf
partitions.
The problem was introduced in commit 9ff68679b5, which removed the
redundant calls to ExecOpenIndices/ExecCloseIndices. The previous code was
relying on the redundant ExecOpenIndices call in
apply_handle_tuple_routing() to build the index information required for
unique key conflict detection.
The fix is to delay building the index information until a conflict is
detected instead of relying on ExecOpenIndices to do the same. The
additional benefit of this approach is that it avoids building index
information when there is no conflict.
Author: Hou Zhijie <houzj.fnst@fujitsu.com>
Reviewed-by:Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/TYAPR01MB57244ADA33DDA57119B9D26494A62@TYAPR01MB5724.jpnprd01.prod.outlook.com
It can be set to either COPY (the default) or CLONE if the system
supports it. CLONE causes callers of copydir(), currently CREATE
DATABASE ... STRATEGY=FILE_COPY and ALTER DATABASE ... SET TABLESPACE =
..., to use copy_file_range (Linux, FreeBSD) or copyfile (macOS) to copy
files instead of a read-write loop over the contents.
CLONE gives the kernel the opportunity to share block ranges on
copy-on-write file systems and push copying down to storage on others,
depending on configuration. On some systems CLONE can be used to clone
large databases quickly with CREATE DATABASE ... TEMPLATE=source
STRATEGY=FILE_COPY.
Other operating systems could be supported; patches welcome.
Co-authored-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Ranier Vilela <ranier.vf@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKGLM%2Bt%2BSwBU-cHeMUXJCOgBxSHLGZutV5zCwY4qrCcE02w%40mail.gmail.com
This adds a function for retrieving memory context statistics
and information from backends as well as auxiliary processes.
The intended usecase is cluster debugging when under memory
pressure or unanticipated memory usage characteristics.
When calling the function it sends a signal to the specified
process to submit statistics regarding its memory contexts
into dynamic shared memory. Each memory context is returned
in detail, followed by a cumulative total in case the number
of contexts exceed the max allocated amount of shared memory.
Each process is limited to use at most 1Mb memory for this.
A summary can also be explicitly requested by the user, this
will return the TopMemoryContext and a cumulative total of
all lower contexts.
In order to not block on busy processes the caller specifies
the number of seconds during which to retry before timing out.
In the case where no statistics are published within the set
timeout, the last known statistics are returned, or NULL if
no previously published statistics exist. This allows dash-
board type queries to continually publish even if the target
process is temporarily congested. Context records contain a
timestamp to indicate when they were submitted.
Author: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Reviewed-by: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Discussion: https://postgr.es/m/CAH2L28v8mc9HDt8QoSJ8TRmKau_8FM_HKS41NeO9-6ZAkuZKXw@mail.gmail.com
Before, BAS_BULKREAD was always of size 256kB. With the default
io_combine_limit of 16, that only allowed 1-2 IOs to be in flight -
insufficient even on very low latency storage.
We don't just want to increase the size to a much larger hardcoded value, as
very large rings (10s of MBs of of buffers), appear to have negative
performance effects when reading in data that the OS has cached (but not when
actually needing to do IO).
To address this, increase the size of BAS_BULKREAD to allow for
io_combine_limit * effective_io_concurrency buffers getting read in. To
prevent the ring being much larger than useful, limit the increased size with
GetPinLimit().
The formula outlined above keeps the ring size to sizes for which we have not
observed performance regressions, unless very large effective_io_concurrency
values are used together with large shared_buffers setting.
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/lqwghabtu2ak4wknzycufqjm5ijnxhb4k73vzphlt2a3wsemcd@gtftg44kdim6
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah@brqs62irg4dt
In addition to the added functions, the pg_buffercache_evict() function now
shows whether the buffer was flushed.
pg_buffercache_evict_relation(): Evicts all shared buffers in a
relation at once.
pg_buffercache_evict_all(): Evicts all shared buffers at once.
Both functions provide mechanism to evict multiple shared buffers at
once. They are designed to address the inefficiency of repeatedly calling
pg_buffercache_evict() for each individual buffer, which can be time-consuming
when dealing with large shared buffer pools. (e.g., ~477ms vs. ~2576ms for
16GB of fully populated shared buffers).
These functions are intended for developer testing and debugging
purposes and are available to superusers only.
Minimal tests for the new functions are included. Also, there was no test for
pg_buffercache_evict(), test for this added too.
No new extension version is needed, as it was already increased this release
by ba2a3c2302.
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Aidar Imamov <a.imamov@postgrespro.ru>
Reviewed-by: Joseph Koshakow <koshy44@gmail.com>
Discussion: https://postgr.es/m/CAN55FZ0h_YoSqqutxV6DES1RW8ig6wcA8CR9rJk358YRMxZFmw%40mail.gmail.com
When planning queries to partitioned tables, we clone all
EquivalenceMembers belonging to the partitioned table into em_is_child
EquivalenceMembers for each non-pruned partition. For partitioned tables
with large numbers of partitions, this meant the ec_members list could
become large and code searching that list would become slow. Effectively,
the more partitions which were present, the more searches needed to be
performed for operations such as find_ec_member_matching_expr() during
create_plan() and the more partitions present, the longer these searches
would take, i.e., a quadratic slowdown.
To fix this, here we adjust how we store EquivalenceMembers for
em_is_child members. Instead of storing these directly in ec_members,
these are now stored in a new array of Lists in the EquivalenceClass,
which is indexed by the relid. When we want to find EquivalenceMembers
belonging to a certain child relation, we can narrow the search to the
array element for that relation.
To make EquivalenceMember lookup easier and to reduce the amount of code
change, this commit provides a pair of functions to allow iteration over
the EquivalenceMembers of an EC which also handles finding the child
members, if required. Callers that never need to look at child members
can remain using the foreach loop over ec_members, which will now often
be faster due to only parent-level members being stored there.
The actual performance increases here are highly dependent on the number
of partitions and the query being planned. Performance increases can be
visible with as few as 8 partitions, but the speedup is marginal for
such low numbers of partitions. The speedups become much more visible
with a few dozen to hundreds of partitions. With some tested queries
using 56 partitions, the planner was around 3x faster than before. For
use cases with thousands of partitions, these are likely to become
significantly faster. Some testing has shown planner speedups of 60x or
more with 8192 partitions.
Author: Yuya Watari <watari.yuya@gmail.com>
Co-authored-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
Reviewed-by: Alena Rybakina <lena.ribackina@yandex.ru>
Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Tested-by: Thom Brown <thom@linux.com>
Tested-by: newtglobal postgresql_contributors <postgresql_contributors@newtglobalcorp.com>
Discussion: https://postgr.es/m/CAJ2pMkZNCgoUKSE%2B_5LthD%2BKbXKvq6h2hQN8Esxpxd%2Bcxmgomg%40mail.gmail.com
Some tests try to invalidate logical slots on the standby server by
running VACUUM on the primary. The problem is that xl_running_xacts was
getting generated and replayed before the VACUUM command, leading to the
advancement of the active slot's catalog_xmin. Due to this, active slots
were not getting invalidated, leading to test failures.
We fix it by skipping the generation of xl_running_xacts for the required
tests with the help of injection points. As the required interface for
injection points was not present in back branches, we fixed the failing
tests in them by disallowing the slot to become active for the required
cases (where rows_removed conflict could be generated).
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 16, where it was introduced
Discussion: https://postgr.es/m/Z6oQXc8LmiTLfwLA@ip-10-97-1-34.eu-west-3.compute.internal
A PG 17 optimization allowed columns with NOT NULL constraints to skip
table scans for IS NULL queries, and to skip IS NOT NULL checks for IS
NOT NULL queries. This didn't work for domain types, since domain types
don't follow the IS NULL/IS NOT NULL constraint logic. To fix, disable
this optimization for domains for PG 17+.
Reported-by: Jan Behrens
Diagnosed-by: Tom Lane
Discussion: https://postgr.es/m/Z37p0paENWWUarj-@momjian.us
Backpatch-through: 17
WAL senders do not flush their statistics until they exit, limiting the
monitoring possible for live processes. This is penalizing when WAL
senders are running for a long time, like in streaming or logical
replication setups, because it is not possible to know the amount of IO
they generate while running.
This commit makes WAL senders more aggressive with their statistics
flush, using an internal of 1 second, with the flush timing calculated
based on the existing GetCurrentTimestamp() done before the sleeps done
to wait for some activity. Note that the sleep done for logical and
physical WAL senders happens in two different code paths, so the stats
flushes need to happen in these two places.
One test is added for the physical WAL sender case, and one for the
logical WAL sender case. This can be done in a stable fashion by
relying on the WAL generated by the TAP tests in combination with a
stats reset while a server is running, but only on HEAD as WAL data has
been added to pg_stat_io in a051e71e28.
This issue exists since a9c70b46db and the introduction of pg_stat_io,
so backpatch down to v16.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/Z73IsKBceoVd4t55@ip-10-97-1-34.eu-west-3.compute.internal
Backpatch-through: 16
Introduce new pg_shmem_alloctions_numa view with information about how
shared memory is distributed across NUMA nodes. For each shared memory
segment, the view returns one row for each NUMA node backing it, with
the total amount of memory allocated from that node.
The view may be relatively expensive, especially when executed for the
first time in a backend, as it has to touch all memory pages to get
reliable information about the NUMA node. This may also force allocation
of the shared memory.
Unlike pg_shmem_allocations, the view does not show anonymous shared
memory allocations. It also does not show memory allocated using the
dynamic shared memory infrastructure.
Author: Jakub Wartak <jakub.wartak@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com
Add basic NUMA awareness routines, using a minimal src/port/pg_numa.c
portability wrapper and an optional build dependency, enabled by
--with-libnuma configure option. For now this is Linux-only, other
platforms may be supported later.
A built-in SQL function pg_numa_available() allows checking NUMA
support, i.e. that the server was built/linked with the NUMA library.
The main function introduced is pg_numa_query_pages(), which allows
determining the NUMA node for individual memory pages. Internally the
function uses move_pages(2) syscall, as it allows batching, and is more
efficient than get_mempolicy(2).
Author: Jakub Wartak <jakub.wartak@enterprisedb.com>
Co-authored-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com
In some edge cases valgrind flags issues with the memory referenced by
IOs. All of the cases addressed in this change are false positives.
Most of the false positives are caused by UnpinBuffer[NoOwner] marking buffer
data as inaccessible. This happens even though the AIO subsystem still holds a
pin. That's good, there shouldn't be accesses to the buffer outside of AIO
related code until it is pinned by "user" code again. But it requires some
explicit work - if the buffer is not pinned by the current backend, we need to
explicitly mark the buffer data accessible/inaccessible while executing
completion callbacks.
That however causes a cascading issue in IO workers: After the completion
callbacks for a buffer is executed, the page is marked as inaccessible. If
subsequently the same worker is executing IO targeting the same buffer, we
would get an error, as the memory is still marked inaccessible. To avoid that,
we need to explicitly mark the memory as accessible in IO workers.
Another issue is that IO executed in workers or via io_uring will not mark
memory as DEFINED. In the case of workers that is because valgrind does not
track memory definedness across processes. For io_uring that is because
valgrind does not understand io_uring, and therefore its IOs never mark memory
as defined, whether the completions are processed in the defining process or
in another context. It's not entirely clear how to best solve that. The
current user of AIO is not affected, as it explicitly marks buffers as DEFINED
& NOACCESS anyway. Defer solving this issue until we have a user with
different needs.
Per buildfarm animal skink.
Reviewed-by: Noah Misch <noah@leadboat.com>
Co-authored-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/3pd4322mogfmdd5nln3zphdwhtmq3rzdldqjwb2sfqzcgs22lf@ok2gletdaoe6
This mirrors 1e0dfd166b (+ 46ef520b95), for temporary table buffers. This
is mainly interesting right now because the AIO work currently triggers
spurious valgrind errors, and the fix for that is cleaner if temp buffers
behave the same as shared buffers.
This requires one change beyond the annotations themselves, namely to pin
local buffers while writing them out in FlushRelationBuffers().
Reviewed-by: Noah Misch <noah@leadboat.com>
Co-authored-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/3pd4322mogfmdd5nln3zphdwhtmq3rzdldqjwb2sfqzcgs22lf@ok2gletdaoe6
The list of transform objects that a function should use is specified
in CREATE FUNCTION's TRANSFORM clause, and then represented indirectly
in pg_proc.protrftypes. However, ProcedureCreate completely ignored
that for purposes of constructing pg_depend entries, and instead made
the function depend on any transforms that exist for its parameter or
return data types. This is bad in both directions: the function could
be made dependent on a transform it does not actually use, or it
could try to use a transform that's since been dropped. (The latter
scenario would require use of a transform that's not for any of the
parameter or return types, but that seems legit for cases where the
function performs SQL operations internally.)
To fix, pass in the list of transform objects that CreateFunction
identified, and build pg_depend entries from that not from the
parameter/return types. This results in changes in the expected
test outputs in contrib/bool_plperl, which I guess are due to
different ordering of pg_depend entries -- that test case is
surely not exercising either of the problem scenarios.
This fix is not back-patchable as-is: changing the signature of
ProcedureCreate seems too risky in stable branches. We could
do something like making ProcedureCreate a wrapper around
ProcedureCreateExt or so. However, I'm more inclined to do
nothing in the back branches. We had no field complaints up to
now, so the hazards don't seem to be a big issue in practice.
And we couldn't do anything about existing pg_depend entries,
so a back-patched fix would result in a mishmash of dependencies
created according to different rules. That cure could be worse
than the disease, perhaps.
I bumped catversion just to lay down a marker that the expected
contents of pg_depend are a bit different than before.
Reported-by: Chapman Flack <jcflack@acm.org>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/3112950.1743984111@sss.pgh.pa.us
This allows them to be added without scanning the table, and validating
them afterwards without holding access exclusive lock on the table after
any violating rows have been deleted or fixed.
Doing ALTER TABLE ... SET NOT NULL for a column that has an invalid
not-null constraint validates that constraint. ALTER TABLE .. VALIDATE
CONSTRAINT is also supported. There are various checks on whether an
invalid constraint is allowed in a child table when the parent table has
a valid constraint; this should match what we do for enforced/not
enforced constraints.
pg_attribute.attnotnull is now only an indicator for whether a not-null
constraint exists for the column; whether it's valid or invalid must be
queried in pg_constraint. Applications can continue to query
pg_attribute.attnotnull as before, but now it's possible that NULL rows
are present in the column even when that's set to true.
For backend internal purposes, we cache the nullability status in
CompactAttribute->attnullability that each tuple descriptor carries
(replacing CompactAttribute.attnotnull, which was a mirror of
Form_pg_attribute.attnotnull). During the initial tuple descriptor
creation, based on the pg_attribute scan, we set this to UNRESTRICTED if
pg_attribute.attnotnull is false, or to UNKNOWN if it's true; then we
update the latter to VALID or INVALID depending on the pg_constraint
scan. This flag is also copied when tupledescs are copied.
Comparing tuple descs for equality must also compare the
CompactAttribute.attnullability flag and return false in case of a
mismatch.
pg_dump deals with these constraints by storing the OIDs of invalid
not-null constraints in a separate array, and running a query to obtain
their properties. The regular table creation SQL omits them entirely.
They are then dealt with in the same way as "separate" CHECK
constraints, and dumped after the data has been loaded. Because no
additional pg_dump infrastructure was required, we don't bump its
version number.
I decided not to bump catversion either, because the old catalog state
works perfectly in the new world. (Trying to run with new catalog state
and the old server version would likely run into issues, however.)
System catalogs do not support invalid not-null constraints (because
commit 14e87ffa5c didn't allow them to have pg_constraint rows
anyway.)
Author: Rushabh Lathia <rushabh.lathia@gmail.com>
Author: Jian He <jian.universality@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Tested-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/CAGPqQf0KitkNack4F5CFkFi-9Dqvp29Ro=EpcWt=4_hs-Rt+bQ@mail.gmail.com
This escape shows the numeric server IP address that the client
has connected to. Unix-socket connections will show "[local]".
Non-client processes (e.g. background processes) will show "[none]".
We expect that this option will be of interest to only a fairly
small number of users. Therefore the implementation is optimized
for the case where it's not used (that is, we don't do the string
conversion until we have to), and we've not added the field to
csvlog or jsonlog formats.
Author: Greg Sabino Mullane <htamfids@gmail.com>
Reviewed-by: Cary Huang <cary.huang@highgo.ca>
Reviewed-by: David Steele <david@pgmasters.net>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAKAnmmK-U+UicE-qbNU23K--Q5XTLdM6bj+gbkZBZkjyjrd3Ow@mail.gmail.com
If the limit returned by GetAdditionalPinLimit() is large, the buffer_limit
variable in read_stream_start_pending_read() can overflow. While the code is
careful to limit buffer_limit PG_INT16_MAX, we subsequently add the number of
forwarded buffers.
The overflow can lead to assertion failures, crashes or wrong query results
when using large shared buffers.
It seems easier to avoid this if we make the buffer_limit variable an int,
instead of an int16. Do so, and clamp buffer_limit after adding the number of
forwarded buffers.
It's possible we might want to address this and related issues more widely by
changing to int instead of int16 more widely, but since the consequences of
this bug can be confusing, it seems better to fix it now.
This bug was introduced in ed0b87caac.
Discussion: https://postgr.es/m/ewvz3cbtlhrwqk7h6ca6cctiqh7r64ol3pzb3iyjycn2r5nxk5@tnhw3a5zatlr
fc069a3a63 implements Self-Join Elimination (SJE) and provides a new GUC
variable: enable_self_join_elimination. This new GUC variable was marked
as GUC_NOT_IN_SAMPLE. However, enable_self_join_elimination is documented
and is not different from any other enable_* GUCs. Thus, remove
GUC_NOT_IN_SAMPLE from it and add it to the postgresql.conf.sample.
Discussion: https://postgr.es/m/CAPpHfdsqMTEsmxk3aQwt6xPz%2BKpUELO%3D6fzmER9ZRGrbs4uMfA%40mail.gmail.com
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
palloc() is invoked with a specific formula for its allocation size in
quote_literal_cstr(). This wastes some memory, but the size is large
enough to cover even the worst-case scenarios.
No explanations were given about the reasons behind these numbers. This
commit adds more documentation about all that.
Author: Steve Chavez <steve@supabase.io>
Discussion: https://postgr.es/m/CAGRrpzZ9bToRWS+fAnjxDJrxwZN1QcJ-y1Pn2yg=Hst6rydLtw@mail.gmail.com
stats_fetch_consistency set to "snapshot" causes the backend entry
"beentry" retrieved by pgstat_get_beentry_by_proc_number() to be reset
at the beginning of pgstat_fetch_stat_backend() when fetching the
backend pgstats entry. As coded, "beentry" was being accessed after
being freed. This commit moves all the accesses to "beentry" to happen
before calling pgstat_fetch_stat_backend(), fixing the problem.
This problem could be reached by calling the SQL functions
pg_stat_get_backend_io() or pg_stat_get_backend_wal().
Issue caught by valgrind.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/f1788cc0-253a-4a3a-aee0-1b8ab9538736@gmail.com
The XLOG_CONTROL_FILE macro (defined in access/xlog_internal.h)
represents the control file name. While some parts of the codebase already
use this macro, others previously hardcoded the file name as a string.
This commit replaces those hardcoded strings with the macro,
ensuring consistent usage throughout the code. This makes future
maintenance easier and improves searchability, for example when
grepping for control file usage.
Author: Anton A. Melnikov <a.melnikov@postgrespro.ru>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Masao Fujii <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/0841ec77-47e5-452a-adb4-c6fa55d605fc@postgrespro.ru
PgAioResult.result is never accessed in the relevant path, but coverity
complains about an uninitialized access anyway. So just zero-initialize the
whole thing. While at it, reduce the scope of the variable.
Reported-by: Ranier Vilela <ranier.vf@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/CAEudQApsKqd-s+fsUQ0OmxJAMHmBSXxrAz3dCs+uvqb3iRtjSw@mail.gmail.com
This should silence Coverity's complaints about the result being
sometimes ignored.
I'm inclined to think that these routines are simply misdesigned,
because sometimes it's okay to ignore the result and sometimes it
isn't, and we have no way to enforce the latter. But for now
I just added a comment.
There were several places in ordering-related planning where a
requirement for btree was hardcoded but an amcanorder index could
suffice. This fixes that. We just need to do the necessary mapping
between strategy numbers and compare types and adjust some related
APIs so that this works independent of btree strategy numbers. For
instance, non-btree amcanorder indexes can now be used to support
sorting and merge joins. Also, predtest.c works independent of btree
strategy numbers now.
To avoid performance regressions, some details on btree and other
built-in index types are still hardcoded as shortcuts, but other index
types now have access to the same features by providing the required
flags and callbacks.
Author: Mark Dilger <mark.dilger@enterprisedb.com>
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
makeDependencyGraphWalker thought that only SelectStmt nodes could
contain a WithClause. Which was true in our original implementation
of WITH, but astonishingly we missed updating this code when we added
the ability to attach WITH to INSERT/UPDATE/DELETE (and later MERGE).
Moreover, since it was coded to deliberately block recursion to a
WithClause, even updating raw_expression_tree_walker didn't save it.
The upshot of this was that we didn't see references to outer CTE
names appearing within an inner WITH, and would neither complain about
disallowed recursion nor account for such references when sorting CTEs
into a usable order. The lack of complaints about this is perhaps not
so surprising, because typical usage of WITH wouldn't hit either case.
Still, it's pretty broken; failing to detect recursion here leads to
assert failures or worse later on.
Fix by factoring out the processing of sub-WITHs into a new function
WalkInnerWith, and invoking that for all the statement types that
can have WITH.
Bug: #18878
Reported-by: Yu Liang <luy70@psu.edu>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18878-a26fa5ab6be2f2cf@postgresql.org
Backpatch-through: 13
transformJsonArrayQueryConstructor() applied transformStmt() to
the same subquery tree twice. While this causes no issue in many
cases, there are some where it causes a coredump, thanks to the
parser's habit of scribbling on its input.
Fix by making a copy before the first transformation (compare
0f43083d1). This is quite brute-force, but then so is the
whole business of transforming the input twice. Per discussion
in the bug thread, this implementation of json_array() parsing
should be replaced completely. But that will take some work
and will surely not be back-patchable, so for the moment let's
take the easy way out.
Oversight in 7081ac46a. Back-patch to v16 where that came in.
Bug: #18877
Reported-by: Yu Liang <luy70@psu.edu>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18877-c3c3ad75845833bb@postgresql.org
Backpatch-through: 16
Since v15 we've had an option to apply a foreign key constraint's
ON DELETE SET DEFAULT or SET NULL action to just some of the
referencing columns. There was not a check for duplicate entries in
the list of columns-to-set, though. That caused a potential memory
stomp in CreateConstraintEntry(), which incautiously assumed that
the list of columns-to-set couldn't be longer than the number of key
columns. Even after fixing that, the case doesn't work because you
get an error like "multiple assignments to same column" from the SQL
command that is generated to do the update.
We could either raise an error for duplicate columns or silently
suppress the dups, and after a bit of thought I chose to do the
latter. This is motivated by the fact that duplicates in the FK
column list are legal, so it's not real clear why duplicates
in the columns-to-set list shouldn't be. Of course there's no
need to actually set the column more than once.
I left in the fix in CreateConstraintEntry() too, just because
it didn't seem like such low-level code ought to be making
assumptions about what it's handed.
Bug: #18879
Reported-by: Yu Liang <luy70@psu.edu>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18879-259fc59d072bd4d7@postgresql.org
Backpatch-through: 15
This is yet another bit of fallout from the fact that backend/parser
(like other code) feels free to scribble on the parse tree it's
handed. In this case that resulted in modifying the
relatively-short-lived copy in the cached function's source_list.
That would be fine since we only need each source_list tree once
... except that if the parser fails after making some changes,
the function cache entry remains as-is and will still be there
if the user tries to execute the function again. Then we have
problems because we're feeding a non-pristine tree to the parser.
The most expedient fix is a quick copyObject(). I considered
other answers like somehow marking the cache entry invalid
temporarily, but that would add complexity and I'm not sure
it's worth it. In typical scenarios we'd only do this once
per function query per session.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/6d442183-102c-498a-81d1-eeeb086cdc5a@gmail.com
Transform low_compare and high_compare nbtree skip array inequalities
(with opclasses that offer skip support) in such a way as to allow
_bt_first to consistently apply later keys when it descends the tree.
This can lower the number of index searches for multi-column scans that
use a ">" key on one of the index's prefix columns (or use a "<" key,
when scanning backwards) when it precedes some later lower-order key.
For example, an index qual "WHERE a > 5 AND b = 2" will now be converted
to "WHERE a >= 6 AND b = 2" by a new preprocessing step that takes place
after low_compare and high_compare have been finalized. That way, the
initial call to _bt_first can use "WHERE a >= 6 AND b = 2" to find an
initial position, rather than just using "WHERE a > 5" -- "b = 2" can be
applied during every _bt_first call. There's a decent chance that this
will allow such a scan to avoid the extra search that might otherwise be
needed to determine the lowest "a" value still satisfying "WHERE a > 5".
The transformation process can only lower the total number of index
pages read when the use of a more restrictive set of initial positioning
keys in _bt_first actually allows the scan to land on some later leaf
page directly, relative to the unoptimized case (or on an earlier leaf
page directly, when scanning backwards). But the savings can really add
up in cases where an affected skip array comes after some other array.
For example, a scan indexqual "WHERE x IN (1, 2, 3) AND y > 5 AND z = 2"
can save as many as 3 _bt_first calls by applying the new transformation
to its "y" array (up to 1 extra search can be avoided per "x" element).
Follow-up to commit 92fe23d9, which added nbtree skip scan.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/CAH2-Wz=FJ78K3WsF3iWNxWnUCY9f=Jdg3QPxaXE=uYUbmuRz5Q@mail.gmail.com
Don't allow nbtree scans with skip arrays to end any primitive scan on
its first leaf page without giving some consideration to how many times
the scan's arrays advanced while changing at least one skip array
(though continue not caring about the number of array advancements that
only affected SAOP arrays, even during skip scans with SAOP arrays).
Now when a scan performs more than 3 such array advancements in the
course of reading a single leaf page, it is taken as a signal that the
next page is unlikely to be skippable. We'll therefore continue the
ongoing primitive index scan, at least until we can perform a recheck
against the next page's finaltup.
Testing has shown that this new heuristic occasionally makes all the
difference with skip scans that were expected to rely on the "passed
first page" heuristic added by commit 9a2e2a28. Without it, there is a
remaining risk that certain kinds of skip scans will never quite manage
to clear the initial hurdle of performing a primitive scan that lasts
beyond its first leaf page (or that such a skip scan will only clear
that initial hurdle when it has already wasted noticeably-many cycles
due to inefficient primitive scan scheduling).
Follow-up to commits 92fe23d9 and 9a2e2a28.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/CAH2-Wz=RVdG3zWytFWBsyW7fWH7zveFvTHed5JKEsuTT0RCO_A@mail.gmail.com
Postgres 17 commit e0b1ee17 added two complementary optimizations to
nbtree: the "prechecked" and "firstmatch" optimizations. _bt_readpage
was made to avoid needlessly evaluating keys that are guaranteed to be
satisfied by applying page-level context. "prechecked" did this for
keys required in the current scan direction, while "firstmatch" did it
for keys required in the opposite-to-scan direction only.
The "prechecked" design had a number of notable issues. It didn't
account for the fact that an = array scan key's sk_argument field might
need to advance at the point of the page precheck (it didn't check the
precheck tuple against the key's array, only the key's sk_argument,
which needlessly made it ineffective in cases involving stepping to a
page having advanced the scan's arrays using a truncated high key).
"prechecked" was also completely ineffective when only one scan key
wasn't guaranteed to be satisfied by every tuple (it didn't recognize
that it was still safe to avoid evaluating other, earlier keys).
The "firstmatch" optimization had similar limitations. It could only be
applied after _bt_readpage found its first matching tuple, regardless of
why any earlier tuples failed to satisfy the scan's index quals. This
allowed unsatisfied non-required scan keys to impede the optimization.
Replace both optimizations with a new optimization, without any of these
limitations: the "startikey" optimization. Affected _bt_readpage calls
generate a page-level key offset ("startikey"), that their _bt_checkkeys
calls can then start at. This is an offset to the first key that isn't
known to be satisfied by every tuple on the page.
Although this is independently useful work, its main goal is to avoid
performance regressions with index scans that use skip arrays, but still
never manage to skip over irrelevant leaf pages. We must avoid wasting
CPU cycles on overly granular skip array maintenance in these cases.
The new "startikey" optimization helps with this by selectively
disabling array maintenance for the duration of a _bt_readpage call.
This has no lasting consequences for the scan's array keys (they'll
still reliably track the scan's progress through the index's key space
whenever the scan is "between pages").
Skip scan adds skip arrays during preprocessing using simple, static
rules, and decides how best to navigate/apply the scan's skip arrays
dynamically, at runtime. The "startikey" optimization enables this
approach. As a result of all this, the planner doesn't need to generate
distinct, competing index paths (one path for skip scan, another for an
equivalent traditional full index scan). The overall effect is to make
scan runtime close to optimal, even when the planner works off an
incorrect cardinality estimate. Scans will also perform well given a
skipped column with data skew: individual groups of pages with many
distinct values (in respect of a skipped column) can be read about as
efficiently as before -- without the scan being forced to give up on
skipping over other groups of pages that are provably irrelevant.
Many scans that cannot possibly skip will still benefit from the use of
skip arrays, since they'll allow the "startikey" optimization to be as
effective as possible (by allowing preprocessing to mark all the scan's
keys as required). A scan that uses a skip array on "a" for a qual
"WHERE a BETWEEN 0 AND 1_000_000 AND b = 42" is often much faster now,
even when every tuple read by the scan has its own distinct "a" value.
However, there are still some remaining regressions, affecting certain
trickier cases.
Scans whose index quals have several range skip arrays, each on some
high cardinality column, can still be slower than they were before the
introduction of skip scan -- even with the new "startikey" optimization.
There are also known regressions affecting very selective index scans
that use a skip array. The underlying issue with such selective scans
is that they never get as far as reading a second leaf page, and so will
never get a chance to consider applying the "startikey" optimization.
In principle, all regressions could be avoided by teaching preprocessing
to not add skip arrays whenever they aren't expected to help, but it
seems best to err on the side of robust performance.
Follow-up to commit 92fe23d9, which added nbtree skip scan.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Reviewed-By: Masahiro Ikeda <ikedamsh@oss.nttdata.com>
Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/CAH2-Wz=Y93jf5WjoOsN=xvqpMjRy-bxCE037bVFi-EasrpeUJA@mail.gmail.com
Discussion: https://postgr.es/m/CAH2-WznWDK45JfNPNvDxh6RQy-TaCwULaM5u5ALMXbjLBMcugQ@mail.gmail.com
Teach nbtree multi-column index scans to opportunistically skip over
irrelevant sections of the index given a query with no "=" conditions on
one or more prefix index columns. When nbtree is passed input scan keys
derived from a predicate "WHERE b = 5", new nbtree preprocessing steps
output "WHERE a = ANY(<every possible 'a' value>) AND b = 5" scan keys.
That is, preprocessing generates a "skip array" (and an output scan key)
for the omitted prefix column "a", which makes it safe to mark the scan
key on "b" as required to continue the scan. The scan is therefore able
to repeatedly reposition itself by applying both the "a" and "b" keys.
A skip array has "elements" that are generated procedurally and on
demand, but otherwise works just like a regular ScalarArrayOp array.
Preprocessing can freely add a skip array before or after any input
ScalarArrayOp arrays. Index scans with a skip array decide when and
where to reposition the scan using the same approach as any other scan
with array keys. This design builds on the design for array advancement
and primitive scan scheduling added to Postgres 17 by commit 5bf748b8.
Testing has shown that skip scans of an index with a low cardinality
skipped prefix column can be multiple orders of magnitude faster than an
equivalent full index scan (or sequential scan). In general, the
cardinality of the scan's skipped column(s) limits the number of leaf
pages that can be skipped over.
The core B-Tree operator classes on most discrete types generate their
array elements with the help of their own custom skip support routine.
This infrastructure gives nbtree a way to generate the next required
array element by incrementing (or decrementing) the current array value.
It can reduce the number of index descents in cases where the next
possible indexable value frequently turns out to be the next value
stored in the index. Opclasses that lack a skip support routine fall
back on having nbtree "increment" (or "decrement") a skip array's
current element by setting the NEXT (or PRIOR) scan key flag, without
directly changing the scan key's sk_argument. These sentinel values
behave just like any other value from an array -- though they can never
locate equal index tuples (they can only locate the next group of index
tuples containing the next set of non-sentinel values that the scan's
arrays need to advance to).
A skip array's range is constrained by "contradictory" inequality keys.
For example, a skip array on "x" will only generate the values 1 and 2
given a qual such as "WHERE x BETWEEN 1 AND 2 AND y = 66". Such a skip
array qual usually has near-identical performance characteristics to a
comparable SAOP qual "WHERE x = ANY('{1, 2}') AND y = 66". However,
improved performance isn't guaranteed. Much depends on physical index
characteristics.
B-Tree preprocessing is optimistic about skipping working out: it
applies static, generic rules when determining where to generate skip
arrays, which assumes that the runtime overhead of maintaining skip
arrays will pay for itself -- or lead to only a modest performance loss.
As things stand, these assumptions are much too optimistic: skip array
maintenance will lead to unacceptable regressions with unsympathetic
queries (queries whose scan can't skip over many irrelevant leaf pages).
An upcoming commit will address the problems in this area by enhancing
_bt_readpage's approach to saving cycles on scan key evaluation, making
it work in a way that directly considers the needs of = array keys
(particularly = skip array keys).
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Masahiro Ikeda <masahiro.ikeda@nttdata.com>
Reviewed-By: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-By: Tomas Vondra <tomas@vondra.me>
Reviewed-By: Aleksander Alekseev <aleksander@timescale.com>
Reviewed-By: Alena Rybakina <a.rybakina@postgrespro.ru>
Discussion: https://postgr.es/m/CAH2-Wzmn1YsLzOGgjAQZdn1STSG_y8qP__vggTaPAYXJP+G4bw@mail.gmail.com
This commit implements the automatic conversion of 'x IN (VALUES ...)' into
ScalarArrayOpExpr. That simplifies the query tree, eliminating the appearance
of an unnecessary join.
Since VALUES describes a relational table, and the value of such a list is
a table row, the optimizer will likely face an underestimation problem due to
the inability to estimate cardinality through MCV statistics. The cardinality
evaluation mechanism can work with the array inclusion check operation.
If the array is small enough (< 100 elements), it will perform a statistical
evaluation element by element.
We perform the transformation in the convert_ANY_sublink_to_join() if VALUES
RTE is proper and the transformation is convertible. The conversion is only
possible for operations on scalar values, not rows. Also, we currently
support the transformation only when it ends up with a constant array.
Otherwise, the evaluation of non-hashed SAOP might be slower than the
corresponding Hash Join with VALUES.
Discussion: https://postgr.es/m/0184212d-1248-4f1f-a42d-f5cb1c1976d2%40tantorlabs.com
Author: Alena Rybakina <a.rybakina@postgrespro.ru>
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Ivan Kush <ivan.kush@tantorlabs.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
This commit extracts the code to generate ScalarArrayOpExpr on top of the list
of expressions from match_orclause_to_indexcol() into a separate function
make_SAOP_expr(). This function was extracted to be used in optimization for
conversion of 'x IN (VALUES ...)' to 'x = ANY ...'. make_SAOP_expr() is
placed in clauses.c file as only two additional headers were needed there
compared with other places.
Discussion: https://postgr.es/m/0184212d-1248-4f1f-a42d-f5cb1c1976d2%40tantorlabs.com
Author: Alena Rybakina <a.rybakina@postgrespro.ru>
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Ivan Kush <ivan.kush@tantorlabs.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Fix for commit 9ef1851685: We have to skip indexes where sortopfamily
is NULL. This takes the place of the previous btree check. Detected
by valgrind on the buildfarm.
Commit 28d3c2ddcf introduced an assertion that if the memorized
downlink location in the insertion stack isn't valid, the parent's
LSN should've changed too. Turns out that was too strict. In
gistFindCorrectParent(), if we walk right, we update the parent's
block number and clear its memorized 'downlinkoffnum'. That triggered
the assertion on next call to gistFindCorrectParent(), if the parent
needed to be split too. Relax the assertion, so that it's OK if
downlinkOffnum is InvalidOffsetNumber.
Backpatch to v13-, all supported versions. The assertion was added in
commit 28d3c2ddcf in v12.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://www.postgresql.org/message-id/18396-03cac9beb2f7aac3@postgresql.org
Previously, "COPY table TO" command worked only with plain tables and
did not support materialized views, even when they were populated and
had physical storage. To copy rows from materialized views,
"COPY (query) TO" command had to be used, instead.
This commit extends "COPY table TO" to support populated materialized
views directly, improving usability and performance, as "COPY table TO"
is generally faster than "COPY (query) TO". Note that copying from
unpopulated materialized views will still result in an error.
Author: jian he <jian.universality@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Reviewed-by: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CACJufxHVxnyRYy67hiPePNCPwVBMzhTQ6FaL9_Te5On9udG=yg@mail.gmail.com
This was previously not supported because the btree strategy numbers
were hardcoded. Now we can support this for any index that has the
required strategy mapping support and the required operators.
If an index scan used for get_actual_variable_range() requires
recheck, we now just ignore it instead of erroring out. With btree we
knew this couldn't happen, but now it might.
Author: Mark Dilger <mark.dilger@enterprisedb.com>
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
Previously, ALTER DEFAULT PRIVILEGES did not support large objects.
This meant that to grant privileges to users other than the owner,
permissions had to be manually assigned each time a large object
was created, which was inconvenient.
This commit extends ALTER DEFAULT PRIVILEGES to allow defining default
access privileges for large objects. With this change, specified privileges
will automatically apply to newly created large objects, making privilege
management more efficient.
As a side effect, this commit introduces the new keyword OBJECTS
since it's used in the syntax of ALTER DEFAULT PRIVILEGES.
Original patch by Haruka Takatsuka, with some fixes and tests by Yugo Nagata,
and rebased by Laurenz Albe.
Author: Takatsuka Haruka <harukat@sraoss.co.jp>
Co-authored-by: Yugo Nagata <nagata@sraoss.co.jp>
Co-authored-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Masao Fujii <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20240424115242.236b499b2bed5b7a27f7a418@sraoss.co.jp
This gets rid of the bespoken ProcessWalRcvInterrupts() function,
which lets walreceiver terminate at any CHECK_FOR_INTERRUPTS() call.
And it's less code anyway.
We can now use the standard libpqsrv_connect_params() libpq wrapper
from libpq-be-fe-helpers.h, removing more code. We attempted to do
that earlier already in commit 728f86fec6, but that was reverted
because it didn't call ProcessWalRcvInterrupts() and therefore didn't
react to shutdown requests. Now that ProcessWalRcvInterrupts() is
gone, it works. As stated in that commit, this also leads to
libpqwalreceiver reserving file descriptors for libpq conncetions,
which is nice.
Author: Andres Freund <andres@anarazel.de> (the earlier commit)
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Yura Sokolov <y.sokolov@postgrespro.ru>
Change the PathKey struct to use CompareType to record the sort
direction instead of hardcoding btree strategy numbers. The
CompareType is then converted to the index-type-specific strategy when
the plan is created.
This reduces the number of places btree strategy numbers are
hardcoded, and it's a self-contained subset of a larger effort to
allow non-btree indexes to behave like btrees.
Author: Mark Dilger <mark.dilger@enterprisedb.com>
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
Derived clauses are stored in ec_derives, a List of RestrictInfos.
These clauses are later looked up by matching the left and right
EquivalenceMembers along with the clause's parent EC.
This linear search becomes expensive in queries with many joins or
partitions, where ec_derives may contain thousands of entries. In
particular, create_join_clause() can spend significant time scanning
this list.
To improve performance, introduce a hash table (ec_derives_hash) that
is built when the list reaches 32 entries -- the same threshold used
for join_rel_hash. The original list is retained alongside the hash
table to support EC merging and serialization
(_outEquivalenceClass()).
Each clause is stored in the hash table using a canonicalized key: the
EquivalenceMember with the lower memory address is placed in the key
before the one with the higher memory address. This avoids storing or
searching for both permutations of the same clause. For clauses
involving a constant EM, the key places NULL in the first slot and the
non-constant EM in the second.
The hash table is initialized using list_length(ec_derives_list) as
the size hint. simplehash internally adjusts this to the next power of
two after dividing by the fillfactor, so this typically results in at
least 64 buckets near the threshold -- avoiding immediate resizing
while adapting to the actual number of entries.
The lookup logic for derived clauses is now centralized in
ec_search_derived_clause_for_ems(), which consults the hash table when
available and falls back to the list otherwise.
The new ec_clear_derived_clauses() always frees ec_derives_list, even
though some of the original code paths that cleared the old
ec_derives field did not. This ensures consistent cleanup and avoids
leaking memory when large lists are discarded.
An assertion originally placed in find_derived_clause_for_ec_member()
is moved into ec_search_derived_clause_for_ems() so that it is
enforced consistently, regardless of whether the hash table or list is
used for lookup.
This design incorporates suggestions by David Rowley, who proposed
both the key canonicalization and the initial sizing approach to
balance memory usage and CPU efficiency.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Tested-by: Dmitry Dolgov <9erthalion6@gmail.com>
Tested-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Tested-by: Amit Langote <amitlangote09@gmail.com>
Tested-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAExHW5vZiQtWU6moszLP5iZ8gLX_ZAUbgEX0DxGLx9PGWCtqUg@mail.gmail.com
find_derived_clause_for_ec_member() searches for a previously-derived
clause that equates a non-constant EquivalenceMember to a constant.
It is only called for EquivalenceClasses with ec_has_const set, and
with a non-constant member the EquivalenceMember to search for.
The matched clause is expected to have the non-constant member on the
left-hand side and the constant EquivalenceMember on the right.
Assert that the RHS is indeed a constant, to catch violations of this
structure and enforce assumptions made by
generate_base_implied_equalities_const().
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CAExHW5scMxyFRqOFE6ODmBiW2rnVBEmeEcA-p4W_CyuEikURdA@mail.gmail.com
Previously bitmap heap scan was not AIO batchmode safe because of the
visibility map reads potentially done for the "skip fetch" optimization
(which skipped fetching tuples from the heap if the pages were all
visible and none of the columns were used in the query).
The skip fetch optimization implementation was found to have bugs and
was removed in 459e7bf8e2, so we can safely enable batchmode for
bitmap heap scans.
Several read stream users asserted that the read stream was exhausted
after looping on that very condition. It was pointed out in an a
review of an as-of-yet uncommitted read stream user [1] that this was
confusing and could lead the reader to think there was a possibility of
some kind of race condition. Remove these asserts.
[1] https://postgr.es/m/F9ACE8D0-B807-4A17-B6BD-87EF0717983D%40yesql.se
As coded, fmgr_sql() would get an assertion failure for a SQL function
that has an empty body and is declared to return some type other than
VOID. Typically you'd never get that far because fmgr_sql_validator()
would reject such a definition (I suspect that's how come I managed to
miss the bug). But if check_function_bodies is off or the function is
polymorphic, the validation check wouldn't get made.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/0fde377a-3870-4d18-946a-ce008ee5bb88@gmail.com
Previously, invalidated logical and physical replication slots could
be copied using the pg_copy_logical_replication_slot and
pg_copy_physical_replication_slot functions. Replication slots that
were invalidated for reasons other than WAL removal retained their
restart_lsn. This meant that a new slot copied from an invalidated
slot could have a restart_lsn pointing to a WAL segment that might
have already been removed.
This commit restricts the copying of invalidated replication slots.
Backpatch to v16, where slots could retain their restart_lsn when
invalidated for reasons other than WAL removal.
For v15 and earlier, this check is not required since slots can only
be invalidated due to WAL removal, and existing checks already handle
this issue.
Author: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CANhcyEU65aH0VYnLiu%3DOhNNxhnhNhwcXBeT-jvRe1OiJTo_Ayg%40mail.gmail.com
Backpatch-through: 16
The check for non-inheritable constraints is performed later, and the
same comment is included at that point.
While we're here, remove one extraneous blank line.
Author: jian he <jian.universality@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CACJufxETi6x86S8EkH8mRfOcm2AenoE9t1pyCFVMpU34gVhF3w@mail.gmail.com
The issue is that the transactions prepared before two-phase decoding is
enabled can fail to replicate to the subscriber after being committed on a
promoted standby following a failover. This is because the two_phase_at
field of a slot, which tracks the LSN from which two-phase decoding
starts, is not synchronized to standby servers. Without two_phase_at, the
logical decoding might incorrectly identify prepared transaction as
already replicated to the subscriber after promotion of standby server,
causing them to be skipped.
To address the issue on HEAD, the two_phase_at field of the slot is
exposed by the pg_replication_slots view and allows the slot
synchronization to copy this value to the corresponding synced slot on the
standby server.
This bug is likely to occur if the user toggles the two_phase option to
true after initial slot creation. Given that altering the two_phase option
of a replication slot is not allowed in PostgreSQL 17, this bug is less
likely to occur. We can't change the view/function definition in
backbranch so we can't push the same fix but we are brainstorming an
appropriate solution for PG17.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/TYAPR01MB5724CC7C288535BBCEEE65DA94A72@TYAPR01MB5724.jpnprd01.prod.outlook.com
compareentry() is declared to work on WordEntryIN structs, but
tsvectorrecv() is using it in two places to work on WordEntry
structs. This is almost okay, since WordEntry is the first
field of WordEntryIN. But on machines with 8-byte pointers,
WordEntryIN will have a larger alignment spec than WordEntry,
and it's at least theoretically possible that the compiler
could generate code that depends on the larger alignment.
Given the lack of field reports, this may be just a hypothetical bug
that upsets nothing except sanitizer tools. Or it may be real on
certain hardware but nobody's tried to use tsvectorrecv() on such
hardware. In any case we should fix it, and the fix is trivial:
just change compareentry() so that it works on WordEntry without any
mention of WordEntryIN. We can also get rid of the quite-useless
intermediate function WordEntryCMP.
Bug: #18875
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18875-07a29c49c825a608@postgresql.org
Backpatch-through: 13
The optimization does not take the removal of TIDs by a concurrent vacuum into
account. The concurrent vacuum can remove dead TIDs and make pages ALL_VISIBLE
while those dead TIDs are referenced in the bitmap. This can lead to a
skip_fetch scan returning too many tuples.
It likely would be possible to implement this optimization safely, but we
don't have the necessary infrastructure in place. Nor is it clear that it's
worth building that infrastructure, given how limited the skip_fetch
optimization is.
In the backbranches we just disable the optimization by always passing
need_tuples=true to table_beginscan_bm(). We can't perform API/ABI changes in
the backbranches and we want to make the change as minimal as possible.
Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reported-By: Konstantin Knizhnik <knizhnik@garret.ru>
Discussion: https://postgr.es/m/CAEze2Wg3gXXZTr6_rwC+s4-o2ZVFB5F985uUSgJTsECx6AmGcQ@mail.gmail.com
Backpatch-through: 13
In the historical implementation of SQL functions (if they don't get
inlined), we built plans for all the contained queries at first call
within an outer query, and then re-used those plans for the duration
of the outer query, and then forgot everything. This was not ideal,
not least because the plans could not be customized to specific values
of the function's parameters. Our plancache infrastructure seems
mature enough to be used here. That will solve both the problem with
not being able to build custom plans and the problem with not being
able to share work across successive outer queries.
Aside from those performance concerns, this change fixes a
longstanding bugaboo with SQL functions: you could not write DDL that
would affect later statements in the same function. That's mostly
still true with new-style SQL functions, since the results of parse
analysis are baked into the stored query trees (and protected by
dependency records). But for old-style SQL functions, it will now
work much as it does with PL/pgSQL functions, because we delay parse
analysis and planning of each query until we're ready to run it.
Some edge cases that require replanning are now handled better too;
see for example the new rowsecurity test, where we now detect an RLS
context change that was previously missed.
One other edge-case change that might be worthy of a release note
is that we now insist that a SQL function's result be generated
by the physically-last query within it. Previously, if the last
original query was deleted by a DO INSTEAD NOTHING rule, we'd be
willing to take the result from the preceding query instead.
This behavior was undocumented except in source-code comments,
and it seems hard to believe that anyone's relying on it.
Along the way to this feature, we needed a few infrastructure changes:
* The plancache can now take either a raw parse tree or an
analyzed-but-not-rewritten Query as the starting point for a
CachedPlanSource. If given a Query, it is caller's responsibility
that nothing will happen to invalidate that form of the query.
We use this for new-style SQL functions, where what's in pg_proc is
serialized Query(s) and we trust the dependency mechanism to disallow
DDL that would break those.
* The plancache now offers a way to invoke a post-rewrite callback
to examine/modify the rewritten parse tree when it is rebuilding
the parse trees after a cache invalidation. We need this because
SQL functions sometimes adjust the parse tree to make its output
exactly match the declared result type; if the plan gets rebuilt,
that has to be re-done.
* There is a new backend module utils/cache/funccache.c that
abstracts the idea of caching data about a specific function
usage (a particular function and set of input data types).
The code in it is moved almost verbatim from PL/pgSQL, which
has done that for a long time. We use that logic now for
SQL-language functions too, and maybe other PLs will have use
for it in the future.
Author: Alexander Pyhalov <a.pyhalov@postgrespro.ru>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://postgr.es/m/8216639.NyiUUSuA9g@aivenlaptop
For GiST, having a sortsupport function allows building the index
using the "sorted build" method, which is much faster.
For b-tree, the sortsupport routine doesn't give any new
functionality, but speeds up sorting a tiny bit. The difference is not
very significant, about 2% in cursory testing on my laptop, because
the range type comparison function has quite a lot of overhead from
detoasting. In any case, since we have the function for GiST anyway,
we might as well register it for the btree opfamily too.
Author: Bernd Helmle <mailings@oopsware.de>
Discussion: https://www.postgresql.org/message-id/64d324ce2a6d535d3f0f3baeeea7b25beff82ce4.camel@oopsware.de
Various places allocated shared memory by first allocating a small chunk
using ShmemInitStruct(), followed by ShmemAlloc() calls to allocate more
memory. Unfortunately, ShmemAlloc() does not update ShmemIndex, so this
affected pg_shmem_allocations - it only shown the initial chunk.
This commit modifies the following allocations, to allocate everything
as a single chunk, and then split it internally.
- PredXactList
- RWConflictPool
- PGPROC structures
- Fast-Path Lock Array
The fast-path lock array is allocated separately, not as a part of the
PGPROC structures allocation.
Author: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAH2L28vHzRankszhqz7deXURxKncxfirnuW68zD7+hVAqaS5GQ@mail.gmail.com
pg_shmem_allocations tracks the memory allocated by ShmemInitStruct(),
but for shared hash tables that covered only the header and hash
directory. The remaining parts (segments and buckets) were allocated
later using ShmemAlloc(), which does not update the shmem accounting.
Thus, these allocations were not shown in pg_shmem_allocations.
This commit improves the situation by allocating all the hash table
parts at once, using a single ShmemInitStruct() call. This way the
ShmemIndex entries (and thus pg_shmem_allocations) better reflect the
proper size of the hash table.
This affects allocations for private (non-shared) hash tables too, as
the hash_create() code is shared. For non-shared tables this however
makes no practical difference.
This changes the alignment a bit. ShmemAlloc() aligns the chunks using
CACHELINEALIGN(), which means some parts (header, directory, segments)
were aligned this way. Allocating all parts as a single chunk removes
this (implicit) alignment. We've considered adding explicit alignment,
but we've decided not to - it seems to be merely a coincidence due to
using the ShmemAlloc() API, not due to necessity.
Author: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAH2L28vHzRankszhqz7deXURxKncxfirnuW68zD7+hVAqaS5GQ@mail.gmail.com
Without this, an additional change to the same pg_attribute row
within the same command will fail. This is possible at least with
ALTER TABLE ADD COLUMN on a multiple-inheritance-pathway structure.
(Another potential hazard is that immediately-following operations
might not see the missingval.)
Introduced by 95f650674, which split the former coding that
used a single pg_attribute update to change both atthasdef and
atthasmissing/attmissingval into two updates, but missed that
this should entail two CommandCounterIncrements as well. Like
that fix, back-patch through v13.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/025a3ffa-5eff-4a88-97fb-8f583b015965@gmail.com
Backpatch-through: 13
Currently, the cancel request key is a 32-bit token, which isn't very
much entropy. If you want to cancel another session's query, you can
brute-force it. In most environments, an unauthorized cancellation of
a query isn't very serious, but it nevertheless would be nice to have
more protection from it. Hence make the key longer, to make it harder
to guess.
The longer cancellation keys are generated when using the new protocol
version 3.2. For connections using version 3.0, short 4-bytes keys are
still used.
The new longer key length is not hardcoded in the protocol anymore,
the client is expected to deal with variable length keys, up to 256
bytes. This flexibility allows e.g. a connection pooler to add more
information to the cancel key, which might be useful for finding the
connection.
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions)
Discussion: https://www.postgresql.org/message-id/508d0505-8b7a-4864-a681-e7e5edfe32aa@iki.fi
This expands the NOT ENFORCED constraint flag, previously only
supported for CHECK constraints (commit ca87c415e2), to foreign key
constraints.
Normally, when a foreign key constraint is created on a table, action
and check triggers are added to maintain data integrity. With this
patch, if a constraint is marked as NOT ENFORCED, integrity checks are
no longer required, making these triggers unnecessary. Consequently,
when creating a NOT ENFORCED foreign key constraint, triggers will not
be created, and the constraint will be marked as NOT VALID.
Similarly, if an existing foreign key constraint is changed to NOT
ENFORCED, the associated triggers will be dropped, and the constraint
will also be marked as NOT VALID. Conversely, if a NOT ENFORCED
foreign key constraint is changed to ENFORCED, the necessary triggers
will be created, and the will be changed to VALID by performing
necessary validation.
Since not-enforced foreign key constraints have no triggers, the
shortcut used for example in psql and pg_dump to skip looking for
foreign keys if the relation is known not to have triggers no longer
applies. (It already didn't work for partitioned tables.)
Author: Amul Sul <sulamul@gmail.com>
Reviewed-by: Joel Jacobson <joel@compiler.org>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: jian he <jian.universality@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Isaac Morland <isaac.morland@gmail.com>
Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com>
Tested-by: Triveni N <triveni.n@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b962c5AcYW9KUt_R_ER5qs3fUGbe4az-SP-vuwPS-w-AGA@mail.gmail.com
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>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Tested-by: Michael Paquier <michael@paquier.xyz>
Even after reaching the minimum recovery point, if there are long-lived
write transactions with 64 subtransactions on the primary, the recovery
snapshot may not yet be ready for hot standby, delaying read-only
connections on the standby. Previously, when read-only connections were
not accepted due to this condition, the following error message was logged:
FATAL: the database system is not yet accepting connections
DETAIL: Consistent recovery state has not been yet reached.
This DETAIL message was misleading because the following message was
already logged in this case:
LOG: consistent recovery state reached
This contradiction, i.e., indicating that the recovery state was consistent
while also stating it wasn’t, caused confusion.
This commit improves the error message to better reflect the actual state:
FATAL: the database system is not yet accepting connections
DETAIL: Recovery snapshot is not yet ready for hot standby.
HINT: To enable hot standby, close write transactions with more than 64 subtransactions on the primary server.
To implement this, the commit introduces a new postmaster signal,
PMSIGNAL_RECOVERY_CONSISTENT. When the startup process reaches
a consistent recovery state, it sends this signal to the postmaster,
allowing it to correctly recognize that state.
Since this is not a clear bug, the change is applied only to the master
branch and is not back-patched.
Author: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Yugo Nagata <nagata@sraoss.co.jp>
Discussion: https://postgr.es/m/02db8cd8e1f527a8b999b94a4bee3165@oss.nttdata.com
Push an ErrorContextCallback adding additional detail about the process
performing the I/O and the owner of the I/O when those are not the same.
For io_method worker, this adds context specifying which process owns
the I/O that the I/O worker is processing.
For io_method io_uring, this adds context only when a backend is
*completing* I/O for another backend. It specifies the pid of the owning
process.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/rdml3fpukrqnas7qc5uimtl2fyytrnu6ymc2vjf2zuflbsjuul%40hyizyjsexwmm
50e17ad28 (v14) and 29f45e299 (v15) made it so the planner could identify
IN and NOT IN clauses which have Const lists as right-hand arguments and
when an appropriate hash function is available for the data types, mark
the ScalarArrayOpExpr as hashable so the executor could execute it more
optimally by building and probing a hash table during expression
evaluation.
These commits both worked correctly when there was only a single
ScalarArrayOpExpr in the given expression being processed by the
planner, but when there were multiple, only the first was checked and any
subsequent ones were not identified, which resulted in less optimal
expression evaluation during query execution for all but the first found
ScalarArrayOpExpr.
Backpatch to 14, where 50e17ad28 was introduced.
Author: David Geier <geidav.pg@gmail.com>
Discussion: https://postgr.es/m/29a76f51-97b0-4c07-87b7-ec8e3b5345c9@gmail.com
Backpatch-through: 14
Create a function that will sort the elements of an array
according to the element type's sort order. If the array
has more than one dimension, the sub-arrays of the first
dimension are sorted per normal array-comparison rules,
leaving their contents alone.
In support of this, add pg_type.typarray to the set of fields
cached by the typcache.
Author: Junwang Zhao <zhjwpku@gmail.com>
Co-authored-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Aleksander Alekseev <aleksander@timescale.com>
Discussion: https://postgr.es/m/CAEG8a3J41a4dpw_-F94fF-JPRXYxw-GfsgoGotKcjs9LVfEEvw@mail.gmail.com
mdreadv() has a codepath to zero out buffers when a read returns zero bytes,
guarded by a check for zero_damaged_pages || InRecovery.
The InRecovery codepath to zero out buffers in mdreadv() appears to be
unreachable. The only known paths to reach mdreadv()/mdstartreadv() in
recovery are XLogReadBufferExtended(), vm_readbuf(), and fsm_readbuf(), each
of which takes care to extend the relation if necessary. This looks to either
have been the case for a long time, or the code was never reachable.
The zero_damaged_pages path is incomplete, as missing segments are not
created.
Putting blocks into the buffer-pool that do not exist on disk is rather
problematic, as such blocks will, at least initially, not be found by scans
that rely on smgrnblocks(), as they are beyond EOF. It also can cause weird
problems with relation extension, as relation extension does not expect blocks
beyond EOF to exist.
Therefore we would like to remove that path.
mdstartreadv(), which I added in e5fe570b51c, does not implement this zeroing
logic. I had started a discussion about that a while ago (linked below), but
forgot to act on the conclusion of the discussion, namely to disable the
in-memory-zeroing behavior.
We could certainly implement equivalent zeroing logic in mdstartreadv(), but
it would have to be more complicated due to potential differences in the
zero_damaged_pages setting between the definer and completor of IO. Given that
we want to remove the logic, that does not seem worth implementing the
necessary logic.
For now, put an Assert(false) and comments documenting this choice into
mdreadv() and comments documenting the deprecation of the path in mdreadv()
and the non-implementation of it in mdstartreadv(). If we, during testing,
discover that we do need the path, we can implement it at that time.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/postgr.es/m/20250330024513.ac.nmisch@google.com
Discussion: https://postgr.es/m/postgr.es/m/3qxxsnciyffyf3wyguiz4besdp5t5uxvv3utg75cbcszojlz7p@uibfzmnukkbd
To make the tests possible, a few functions from bufmgr.c/localbuf.c had to be
exported, via buf_internals.h.
Reviewed-by: Noah Misch <noah@leadboat.com>
Co-authored-by: Andres Freund <andres@anarazel.de>
Co-authored-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Due to splitting the block id into two 16 bit integers, BlockIdSet()
is more expensive than one might think. Doing it once per returned
tuple shows up as a small but reliably reproducible cost. It's simple
enough to set the block number just once per block in pagemode, so do
so.
Author: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/lxzj26ga6ippdeunz6kuncectr5gfuugmm2ry22qu6hcx6oid6@lzx3sjsqhmt6
Previously effective_io_concurrency and maintenance_io_concurrency could not
be set above 0 on machines without fadvise support. AIO enables IO concurrency
without such support, via io_method=worker.
Currently only subsystems using the read stream API will take advantage of
this. Other users of maintenance_io_concurrency (like recovery prefetching)
which leverage OS advice directly will not benefit from this change. In those
cases, maintenance_io_concurrency will have no effect on I/O behavior.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/CAAKRu_atGgZePo=_g6T3cNtfMf0QxpvoUh5OUqa_cnPdhLd=gw@mail.gmail.com
Submitting IO in larger batches can be more efficient than doing so
one-by-one, particularly for many small reads. It does, however, require
the ReadStreamBlockNumberCB callback to abide by the restrictions of AIO
batching (c.f. pgaio_enter_batchmode()). Basically, the callback may not:
a) block without first calling pgaio_submit_staged(), unless a
to-be-waited-on lock cannot be part of a deadlock, e.g. because it is
never held while waiting for IO.
b) directly or indirectly start another batch pgaio_enter_batchmode()
As this requires care and is nontrivial in some cases, batching is only
used with explicit opt-in.
This patch adds an explicit flag (READ_STREAM_USE_BATCHING) to read_stream and
uses it where appropriate.
There are two cases where batching would likely be beneficial, but where we
aren't using it yet:
1) bitmap heap scans, because the callback reads the VM
This should soon be solved, because we are planning to remove the use of
the VM, due to that not being sound.
2) The first phase of heap vacuum
This could be made to support batchmode, but would require some care.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Adapt the read stream logic for real AIO:
- If AIO is enabled, we shouldn't issue advice, but if it isn't, we should
continue issuing advice
- AIO benefits from reading ahead with direct IO
- If effective_io_concurrency=0, pass READ_BUFFERS_SYNCHRONOUSLY to
StartReadBuffers() to ensure synchronous IO execution
There are further improvements we should consider:
- While in read_stream_look_ahead(), we can use AIO batch submission mode for
increased efficiency. That however requires care to avoid deadlocks and thus
done separately.
- It can be beneficial to defer starting new IOs until we can issue multiple
IOs at once. That however requires non-trivial heuristics to decide when to
do so.
Reviewed-by: Noah Misch <noah@leadboat.com>
Co-authored-by: Andres Freund <andres@anarazel.de>
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
This finally introduces the first actual use of AIO. StartReadBuffers() now
uses the AIO routines to issue IO.
As the implementation of StartReadBuffers() is also used by the functions for
reading individual blocks (StartReadBuffer() and through that
ReadBufferExtended()) this means all buffered read IO passes through the AIO
paths. However, as those are synchronous reads, actually performing the IO
asynchronously would be rarely beneficial. Instead such IOs are flagged to
always be executed synchronously. This way we don't have to duplicate a fair
bit of code.
When io_method=sync is used, the IO patterns generated after this change are
the same as before, i.e. actual reads are only issued in WaitReadBuffers() and
StartReadBuffers() may issue prefetch requests. This allows to bypass most of
the actual asynchronicity, which is important to make a change as big as this
less risky.
One thing worth calling out is that, if IO is actually executed
asynchronously, the precise meaning of what track_io_timing is measuring has
changed. Previously it tracked the time for each IO, but that does not make
sense when multiple IOs are executed concurrently. Now it only measures the
time actually spent waiting for IO. A subsequent commit will adjust the docs
for this.
While AIO is now actually used, the logic in read_stream.c will often prevent
using sufficiently many concurrent IOs. That will be addressed in the next
commit.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Co-authored-by: Andres Freund <andres@anarazel.de>
Co-authored-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Discussion: https://postgr.es/m/20210223100344.llw5an2aklengrmn@alap3.anarazel.de
Discussion: https://postgr.es/m/stj36ea6yyhoxtqkhpieia2z4krnam7qyetc57rfezgk4zgapf@gcnactj4z56m
This commit implements the infrastructure to perform asynchronous reads into
the buffer pool.
To do so, it:
- Adds readv AIO callbacks for shared and local buffers
It may be worth calling out that shared buffer completions may be run in a
different backend than where the IO started.
- Adds an AIO wait reference to BufferDesc, to allow backends to wait for
in-progress asynchronous IOs
- Adapts StartBufferIO(), WaitIO(), TerminateBufferIO(), and their localbuf.c
equivalents, to be able to deal with AIO
- Moves the code to handle BM_PIN_COUNT_WAITER into a helper function, as it
now also needs to be called on IO completion
As of this commit, nothing issues AIO on shared/local buffers. A future commit
will update StartReadBuffers() to do so.
Buffer reads executed through this infrastructure will report invalid page /
checksum errors / warnings differently than before:
In the error case the error message will cover all the blocks that were
included in the read, rather than just the reporting the first invalid
block. If more than one block is invalid, the error will include information
about the range of the read, the first invalid block and the number of invalid
pages, with a HINT towards the server log for per-block details.
For the warning case (i.e. zero_damaged_buffers) we would previously emit one
warning message for each buffer in a multi-block read. Now there is only a
single warning message for the entire read, again referring to the server log
for more details in case of multiple checksum failures within a single larger
read.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Discussion: https://postgr.es/m/20210223100344.llw5an2aklengrmn@alap3.anarazel.de
Discussion: https://postgr.es/m/stj36ea6yyhoxtqkhpieia2z4krnam7qyetc57rfezgk4zgapf@gcnactj4z56m
If an IO succeeds, but issues a warning, e.g. due to a page verification
failure with zero_damaged_pages, we want to issue that warning in the context
of the issuer of the IO, not the process that executes the completion (always
the case for worker).
It's already possible for a completion callback to report a custom error
message, we just didn't have a result status that allowed a user of AIO to
know that a warning should be emitted even though the IO request succeeded.
All that's needed for that is a dedicated PGAIO_RS_ value.
Previously there were not enough bits in PgAioResult.id for the new
value. Increase. While at that, add defines for the amount of bits and static
asserts to check that the widths are appropriate.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250329212929.a6.nmisch@google.com
For AIO the completion of a read into shared buffers (i.e. verifying the page
including the checksum, updating the BufferDesc to reflect the IO) can happen
in a different backend than the backend that started the IO. As
ignore_checksum_failure can differ between backends, we need to allow the
caller of PageIsVerified() control whether to ignore checksum failures.
The commit leaves a gap in the PIV_* values, as an upcoming commit, which
depends on this commit, will add PIV_LOG_LOG, which better fits just after
PIV_LOG_WARNING.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250329212929.a6.nmisch@google.com
For AIO we execute completion callbacks in critical sections (to ensure that
AIO can in the future be used for WAL, which in turn requires that we can call
completion callbacks in critical sections, to get the resources for WAL
io). To report checksum errors a backend now has to call
pgstat_prepare_report_checksum_failure(), before entering a critical section,
which guarantees the relevant pgstats entry is in shared memory, the relevant
DSM segment is mapped into the backend's memory and the address is known via a
PgStat_EntryRef.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/wkjj4p2rmkevutkwc6tewoovdqznj6c6nvjmvii4oo5wmbh5sr@retq7d6uqs4j
We have errmsg_internal(), errdetail_internal(), but not errhint_internal().
Sometimes it is useful to output a hint with already translated format
string (e.g. because there different messages depending on the condition). For
message/detail we do that with the _internal() variants, but we can't do that
with hint today. It's possible to work around that that by using something
like
str = psprintf(translated_format, args);
ereport(...
errhint("%s", str);
but that's not exactly pretty and makes it harder to avoid memory leaks.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/ym3dqpa4xcvoeknewcw63x77vnqdosbqcetjinb2zfoh65k55m@m4ozmwhr6lk6
For AIO on temporary table buffers the AIO subsystem needs to be able to
ensure a pin on a buffer while AIO is going on, even if the IO issuing query
errors out. Tracking the buffer in LocalRefCount does not work, as it would
cause CheckForLocalBufferLeaks() to assert out.
Instead, also track the refcount in BufferDesc.state, not just
LocalRefCount. This also makes local buffers behave a bit more akin to shared
buffers.
Note that we still don't need locking, AIO completion callbacks for local
buffers are executed in the issuing session (i.e. nobody else has access to
the BufferDesc).
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Some of these comments have been wrong for a while (12f3867f55), some I
recently introduced (da7226993f, 55b454d0e1). This includes an update to a
comment in FlushBuffer(), which will be copied in a future commit.
These changes seem big enough to be worth doing in separate commits.
Suggested-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250319212530.80.nmisch@google.com
Checksum failure stats could be attributed to the wrong database in two cases:
- when a read of a shared relation encountered a checksum error , it would be
attributed to the current database, instead of the "database" representing
shared relations
- when using CREATE DATABASE ... STRATEGY WAL_LOG checksum errors in the
source database would be attributed to the current database
The checksum stats reporting via PageIsVerifiedExtended(PIV_REPORT_STAT) does
not have access to the information about what database a page belongs to.
This fixes the issue by removing PIV_REPORT_STAT and delegating the
responsibility to report stats to the caller, which now can learn about the
number of stats via a new optional argument.
As this changes the signature of PageIsVerifiedExtended() and all callers
should adapt to the new signature, use the occasion to rename the function to
PageIsVerified() and remove the compatibility macro.
We could instead have fixed this by adding information about the database to
the args of PageIsVerified(), but there are soon-to-be-applied patches that
need to separate the stats reporting from the PageIsVerified() call
anyway. Those patches also include testing for the failure paths, something we
inexplicably have not had.
As there is no caller of pgstat_report_checksum_failure() left, remove it.
It'd be possible, but awkward to fix this in the back branches. We considered
doing the work not quite worth it, as mis-attributed stats should still elicit
concern. The emitted error messages do allow to attribute the errors
correctly.
Discussion: https://postgr.es/m/5tyic6epvdlmd6eddgelv47syg2b5cpwffjam54axp25xyq2ga@ptwkinxqo3az
Discussion: https://postgr.es/m/mglpvvbhighzuwudjxzu4br65qqcxsnyvio3nl4fbog3qknwhg@e4gt7npsohuz
ExecInitPartitionInfo() duplicates much of the logic in
ExecInitMerge(), except that it failed to handle DO NOTHING
actions. This would cause an "unknown action in MERGE WHEN clause"
error if a MERGE with any DO NOTHING actions attempted to insert into
a partition not already initialised by ExecInitModifyTable().
Bug: #18871
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Gurjeet Singh <gurjeet@singh.im>
Discussion: https://postgr.es/m/18871-b44e3c96de3bd2e8%40postgresql.org
Backpatch-through: 15
Currently, group_similar_or_args() permutes original positions of clauses
independently on whether it manages to find any groups of similar clauses.
While we are not providing any strict warranties on saving the original order
of OR-clauses, it is preferred that the original order be modified as little
as possible.
This commit changes the reordering algorithm of group_similar_or_args() in
the following way. We reorder each group of similar clauses so that the
first item of the group stays in place, but all the other items are moved
after it. So, if there are no similar clauses, the order of clauses stays
the same. When there are some groups, only required reordering happens while
the rest of the clauses remain in their places.
Reported-by: Andrei Lepikhov <lepihov@gmail.com>
Discussion: https://postgr.es/m/3ac7c436-81e1-4191-9caf-b0dd70b51511%40gmail.com
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Alena Rybakina <a.rybakina@postgrespro.ru>
The uuidv7_interval() function previously converted a shifted
microsecond-precision timestamp (64-bit integer) to another 64-bit
integer representing a timestamp with nanosecond precision. This
conversion caused overflow for dates beyond the year 2262. The
millisecond and sub-millisecond parts were then extracted from this
nanosecond-precision timestamp and stored in UUIDv7 values.
With this commit, the millisecond and sub-millisecond parts are stored
directly into the UUIDv7 value without being converted back to a
nanosecond precision timestamp. Following RFC 9562, the timestamp is
stored as an unsigned integer, enabling support for dates up to the
year 10889.
Reported and fixed by Andrey Borodin, with cosmetic changes and
regression tests by me.
Reported-by: Andrey Borodin <x4mmm@yandex-team.ru>
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/96DEC2D9-659A-40E8-B7BA-AF5D162A9E21@yandex-team.ru
This was left out of the original patch for virtual generated columns
(commit 83ea6c5402).
This just involves a bit of extra work in the executor to expand the
generation expressions and run a "IS NOT NULL" test against them.
There is also a bit of work to make sure that not-null constraints are
checked during a table rewrite.
Author: jian he <jian.universality@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Navneet Kumar <thanit3111@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CACJufxHArQysbDkWFmvK+D1TPHQWWTxWN15cMuUaTYX3xhQXgg@mail.gmail.com
Modernize code in ExecRelCheck() and ExecConstraints() a bit,
preparing the way for some new code.
Co-authored-by: jian he <jian.universality@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Navneet Kumar <thanit3111@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CACJufxHArQysbDkWFmvK+D1TPHQWWTxWN15cMuUaTYX3xhQXgg@mail.gmail.com
This removes some setlocale() calls and a lot of commentary about how
dangerous that is. strftime_l() is from POSIX 2008, and on Windows we
use _wcsftime_l().
While here, adjust error message for strftime_l() failure: it does not
in practice set errno (even though POSIX says it could), so no %m.
Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/CA%2BhUKGJqVe0%2BPv9dvC9dSums_PXxGo9SWcxYAMBguWJUGbWz-A%40mail.gmail.com
check_createrole_self_grant and check_synchronized_standby_slots
were allocating memory on a LOG elevel without checking if the
allocation succeeded or not, which would have led to a segfault
on allocation failure.
On top of that, a number of callsites were using the ERROR level,
relying on erroring out rather than returning false to allow the
GUC machinery handle it gracefully. Other callsites used WARNING
instead of LOG. While neither being not wrong, this changes all
check_ functions do it consistently with LOG.
init_custom_variable gets a promoted elevel to FATAL to keep
the guc_malloc error handling in line with the rest of the
error handling in that function which already call FATAL. If
we encounter an OOM in this callsite there is no graceful
handling to be had, better to error out hard.
Backpatch the fix to check_createrole_self_grant down to v16
and the fix to check_synchronized_standby_slots down to v17
where they were introduced.
Author: Daniel Gustafsson <daniel@yesql.se>
Reported-by: Nikita <pm91.arapov@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Bug: #18845
Discussion: https://postgr.es/m/18845-582c6e10247377ec@postgresql.org
Backpatch-through: 16
Commit 62d712ecfd introduced the capability to calculate the same
queryId for queries with different lengths of constants in a list for an
IN clause. This behavior was originally enabled with a GUC
query_id_squash_values. After a discussion about the value of such a
GUC, it was decided to back out of the use of a GUC and make the
squashing behavior the only available option.
Author: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/Z-LZyygkkNyA8-kR@msg.df7cb.de
Discussion: https://postgr.es/m/CA+q6zcVTK-3C-8NWV1oY2NZrvtnMCDqnyYYyk1T7WMUG65MeOQ@mail.gmail.com
This involves four different implementation strategies:
1. For Windows, we now require _configthreadlocale() to be available
and work (commit f1da075d9a), and the documentation says that the
object returned by localeconv() is in thread-local memory.
2. For glibc, we translate to nl_langinfo_l() calls, because it
offers the same information that way as an extension, and that API is
thread-safe.
3. For macOS/*BSD, use localeconv_l(), which is thread-safe.
4. For everything else, use uselocale() to set the locale for the
thread, and use a big ugly lock to defend against the returned object
being concurrently clobbered. In practice this currently means only
Solaris.
The new call is used in pg_locale.c, replacing calls to setlocale() and
localeconv().
Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/CA%2BhUKGJqVe0%2BPv9dvC9dSums_PXxGo9SWcxYAMBguWJUGbWz-A%40mail.gmail.com
Commit d45597f72f introduced the ability to change a not-null
constraint from NO INHERIT to INHERIT and vice versa, but we included
the SET noise word in the syntax for it. The SET turns out not to be
necessary and goes against what the SQL standard says for other ALTER
TABLE subcommands, so remove it.
This changes the way this command is processed for constraint types
other than not-null, so there are some error message changes.
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Suraj Kharage <suraj.kharage@enterprisedb.com>
Discussion: https://postgr.es/m/202503251602.vsxaehsyaoac@alvherre.pgsql
f31aad9b0 adjusted query jumbling so it no longer ignores NULL nodes
during the jumble. This added some overhead. Here we tune a few
things to make jumbling faster again. This makes jumbling perform
similar or even slightly faster than prior to that change.
Author: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAApHDvreP04nhTKuYsPw0F-YN+4nr4f=L72SPeFb81jfv+2c7w@mail.gmail.com
Previously NULL nodes were ignored. This could cause issues where the
computed query ID could match for queries where fields that are next to
each other in their Node struct where one field was NULL and the other
non-NULL. For example, the Query struct had distinctClause and sortClause
next to each other. If someone wrote;
SELECT DISTINCT c1 FROM t;
and then;
SELECT c1 FROM t ORDER BY c1;
these would produce the same query ID since, in the first query, we
ignored the NULL sortClause and appended the jumble bytes for the
distictClause. In the latter query, since we did nothing for the NULL
distinctClause then jumble the non-NULL sortClause, and since the node
representation stored is the same in both cases, the query IDs were
identical.
Here we fix this by always accounting for NULL nodes by recording that
we saw a NULL in the jumble buffer. This fixes the issue as the order that
the NULL is recorded isn't the same in the above two queries.
Author: Bykov Ivan <i.bykov@modernsys.ru>
Author: Michael Paquier <michael@paquier.xyz>
Author: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/aafce7966e234372b2ba876c0193f1e9%40localhost.localdomain
The implementation of FSM for indexes is simpler than heap, where 0 is
used to track if a page is in-use and (BLCKSZ - 1) if a page is free.
One comment in indexfsm.c and one description in the documentation of
pg_freespacemap were incorrect about that.
Author: Alex Friedman <alexf01@gmail.com>
Discussion: https://postgr.es/m/71eef655-c192-453f-ac45-2772fec2cb04@gmail.com
Backpatch-through: 13
Performing AIO using io_uring can be considerably faster than
io_method=worker, particularly when lots of small IOs are issued, as
a) the context-switch overhead for worker based AIO becomes more significant
b) the number of IO workers can become limiting
io_uring, however, is linux specific and requires an additional compile-time
dependency (liburing).
This implementation is fairly simple and there are substantial optimization
opportunities.
The description of the existing AIO_IO_COMPLETION wait event is updated to
make the difference between it and the new AIO_IO_URING_EXECUTION clearer.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Jakub Wartak <jakub.wartak@enterprisedb.com>
Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt
Discussion: https://postgr.es/m/20210223100344.llw5an2aklengrmn@alap3.anarazel.de
Discussion: https://postgr.es/m/stj36ea6yyhoxtqkhpieia2z4krnam7qyetc57rfezgk4zgapf@gcnactj4z56m
The old naming pattern (mirroring liburing's naming) was inconsistent with
the (not yet introduced) callers. It seems better to get rid of the
inconsistency now than to grow more users of the odd naming.
Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250326001915.bc.nmisch@google.com
Otherwise the results of e.g. temp table buffer verification errors will not
reach bufmgr.c. Obviously that's not right. Found while expanding the tests
for invalid buffer contents.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250326001915.bc.nmisch@google.com
As reported by Noah, it's possible, although practically very unlikely, that
interrupts could be processed in between pgaio_io_reopen() and
pgaio_io_perform_synchronously(). Prevent that by explicitly holding
interrupts.
It also seems good to add an assertion to pgaio_io_before_prep() to ensure
that interrupts are held, as otherwise FDs referenced by the IO could be
closed during interrupt processing. All code in the aio series currently runs
the code with interrupts held, but it seems better to be paranoid.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250324002939.5c.nmisch@google.com
The brin_bloom_union() function combines two BRIN summaries, by merging
one filter into the other. With bloom, we have to decompress the filters
first, but the function failed to update the summary to store the merged
filter. As a consequence, the index may be missing some of the data, and
return false negatives.
This issue exists since BRIN bloom indexes were introduced in Postgres
14, but at that point the union function was called only when two
sessions happened to summarize a range concurrently, which is rare. It
got much easier to hit in 17, as parallel builds use the union function
to merge summaries built by workers.
Fixed by storing a pointer to the decompressed filter, and freeing the
original one. Free the second filter too, if it was decompressed. The
freeing is not strictly necessary, because the union is called in
short-lived contexts, but it's tidy.
Backpatch to 14, where BRIN bloom indexes were introduced.
Reported by Arseniy Mukhin, investigation and fix by me.
Reported-by: Arseniy Mukhin
Discussion: https://postgr.es/m/18855-1cf1c8bcc22150e6%40postgresql.org
Backpatch-through: 14
It seems potentially useful to label our shared libraries with version
information, now that a facility exists for retrieving that. This
patch labels them with the PG_VERSION string. There was some
discussion about using semantic versioning conventions, but that
doesn't seem terribly helpful for modules with no SQL-level presence;
and for those that do have SQL objects, we typically expect them
to support multiple revisions of the SQL definitions, so it'd still
not be very helpful.
I did not label any of src/test/modules/. It seems unnecessary since
we don't install those, and besides there ought to be someplace that
still provides test coverage for the original PG_MODULE_MAGIC macro.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/dd4d1b59-d0fe-49d5-b28f-1e463b68fa32@gmail.com
This macro allows dynamically loaded shared libraries (modules) to
provide a wired-in module name and version, and possibly other
compile-time-constant fields in future. This information can be
retrieved with the new pg_get_loaded_modules() function.
This feature is expected to be particularly useful for modules
that do not have any exposed SQL functionality and thus are
not associated with a SQL-level extension object. But even for
modules that do belong to extensions, being able to verify the
actual code version can be useful.
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Yurii Rashkovskii <yrashk@omnigres.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/dd4d1b59-d0fe-49d5-b28f-1e463b68fa32@gmail.com
These are useful general-purpose math functions which are included in
POSIX and C99, and are commonly included in other math libraries, so
expose them as SQL-callable functions.
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Stepan Neretin <sncfmgg@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Dmitry Koval <d.koval@postgrespro.ru>
Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com>
Discussion: https://postgr.es/m/CAEZATCXpGyfjXCirFk9au+FvM0y2Ah+2-0WSJx7MO368ysNUPA@mail.gmail.com
custom_query_jumble (introduced in 5ac462e2b7 as a node field
attribute) is now assigned to the expanded reference name "eref" of
RangeTblEntry, adding in the query jumble computation the non-qualified
aliased relation name, without the list of column names. The relation
OID is removed from the query jumbling.
The effects of this change can be seen in the tests added by
3430215fe3, where pg_stat_statements (PGSS) entries are now grouped
using the relation name, ignoring the relation search_path may point at.
For example, these two relations are different, but are now grouped in a
single PGSS entry as they are assigned the same query ID:
CREATE TABLE foo1.tab (a int);
CREATE TABLE foo2.tab (b int);
SET search_path = 'foo1';
SELECT count(*) FROM tab;
SET search_path = 'foo2';
SELECT count(*) FROM tab;
SELECT count(*) FROM foo1.tab;
SELECT count(*) FROM foo2.tab;
SELECT query, calls FROM pg_stat_statements WHERE query ~ 'FROM tab';
query | calls
--------------------------+-------
SELECT count(*) FROM tab | 4
(1 row)
It is still possible to use an alias in the FROM clause to split these.
This behavior is useful for relations re-created with the same name,
where queries based on such relations would be grouped in the same
PGSS entry. For permanent schemas, it should not really matter in
practice. The main benefit is for workloads that use a lot of temporary
relations, which are usually re-created with the same name continuously.
These can be a heavy source of bloat in PGSS depending on the workload.
Such entries can now be grouped together, improving the user experience.
The original idea from Christoph Berg used catalog lookups to find
temporary relations, something that the query jumble has never done, and
it could cause some performance regressions. The idea to use
RangeTblEntry.eref and the relation name, applying the same rules for
all relations, temporary and not temporary, has been proposed by Tom
Lane. The documentation additions have been suggested by Sami Imseih.
Author: Michael Paquier <michael@paquier.xyz>
Co-authored-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Christoph Berg <myon@debian.org>
Reviewed-by: Lukas Fittl <lukas@fittl.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/Z9iWXKGwkm8RAC93@msg.df7cb.de
A node field marked with custom_query_jumble and query_jumble_ignore
would generate some code of a custom routine. The script is changed so
as custom_query_jumble behaves like the other options in this case,
query_jumble_ignore taking priority, with no code generated.
A comment related to the code generated for node types was misplaced.
Thinkos introduced in 5ac462e2b7.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1324036.1742945060@sss.pgh.pa.us
For import and export, use schemaname/relname rather than
regclass.
This is more natural during export, fits with the other arguments
better, and it gives better control over error handling in case we
need to downgrade more errors to warnings.
Also, use text for the argument types for schemaname, relname, and
attname so that casts to "name" are not required.
Author: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://postgr.es/m/CADkLM=ceOSsx_=oe73QQ-BxUFR2Cwqum7-UP_fPe22DBY0NerA@mail.gmail.com
Currently, createForeignKeyCheckTriggers() takes a Relation type as
its first argument, but it doesn't use that argument directly.
Instead, it fetches the relation OID by calling RelationGetRelid().
Therefore, it would be more consistent with other functions (e.g.,
createForeignKeyCheckTriggers()) to pass the relation OID directly
instead of the whole Relation.
Author: Amul Sul <amul.sul@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b962c5AcYW9KUt_R_ER5qs3fUGbe4az-SP-vuwPS-w-AGA@mail.gmail.com
Split ATExecAlterConstraintInternal() into two functions:
ATExecAlterConstrDeferrability() and
ATExecAlterConstrInheritability(). This simplifies the code and
avoids unnecessary confusion caused by recursive code, which isn't
needed for ATExecAlterConstrInheritability().
(This also takes over the changes in commit 64224a834c, as the new
AlterConstrDeferrabilityRecurse() is essentially the old
ATExecAlterChildConstr().)
Author: Amul Sul <amul.sul@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b962c5AcYW9KUt_R_ER5qs3fUGbe4az-SP-vuwPS-w-AGA@mail.gmail.com
Small fixes for commit f4e53e10b6: Add missing calls to
InvokeObjectPostAlterHook() and also CacheInvalidateRelcache(). The
former change could have a user-visible effect. The latter omission
might have caused other bugs, but it is not clear whether one actually
existed. With these changes, the code is now more consistent with
similar ALTER CONSTRAINT variants, especially the ones that set the
deferrability.
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CAF1DzPVfOW6Kk=7SSh7LbneQDJWh=PbJrEC_Wkzc24tHOyQWGg@mail.gmail.com
The network (inet) support functions currently only supported a
hardcoded btree operator family. With the generalized compare type
facility, we can generalize this to support any operator family from
any index type that supports the required operators.
Author: Mark Dilger <mark.dilger@enterprisedb.com>
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
This option gives the possibility for query jumble to define a custom
routine for the field of a Node, extending support for
custom_query_jumble as a node field attribute. When dealing with
complex node structures, this can be simpler than having to enforce a
custom function across a full node.
Custom functions need to be defined in queryjumblefuncs.c, named as
_jumble${node}_${field}(), and use in input the JumbleState, the node
and its field. The field is not really required if we have the Node,
but it makes custom implementations somewhat easier to think about. The
code generated by gen_node_support.pl uses a macro called
JUMBLE_CUSTOM(), hiding the internals of the logic inside
queryjumblefuncs.c.
This will be used by an upcoming patch manipulating adding a custom
routine into a field of RangeTblEntry, but this facility can become
useful in more cases.
Reviewed-by: Christoph Berg <myon@debian.org>
Discussion: https://postgr.es/m/Z9y43-dRvb4EtxQ0@paquier.xyz
Reduces memory required for hash aggregation by avoiding an allocation
and a pointer in the TupleHashEntryData structure. That structure is
used for all buckets, whether occupied or not, so the savings is
substantial.
Discussion: https://postgr.es/m/AApHDvpN4v3t_sdz4dvrv1Fx_ZPw=twSnxuTEytRYP7LFz5K9A@mail.gmail.com
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Allows an "extra" argument that allocates extra memory at the end of
the MinimalTuple. This is important for callers that need to store
additional data, but do not want to perform an additional allocation.
Suggested-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAApHDvppeqw2pNM-+ahBOJwq2QmC0hOAGsmCpC89QVmEoOvsdg@mail.gmail.com
The entries aren't freed until the entire hash table is destroyed, so
use the Bump allocator to improve allocation speed, avoid wasting
space on the chunk header, and avoid wasting space due to the
power-of-two allocations.
Discussion: https://postgr.es/m/CAApHDvqv1aNB4cM36FzRwivXrEvBO_LsG_eQ3nqDXTjECaatOQ@mail.gmail.com
Reviewed-by: David Rowley
Until now max_files_per_process=N limited each backend to open N files in
total (minus a safety factor), even if there were already more files opened in
postmaster and inherited by backends. Change max_files_per_process to control
how many additional files each process is allowed to open.
The main motivation for this is the patch to add io_method=io_uring, which
needs to open one file for each backend. Without this patch, even if
RLIMIT_NOFILE is high enough, postmaster will fail in set_max_safe_fds() if
started with a high max_connections. The cause of the failure is that, until
now, set_max_safe_fds() subtracted the already open files from
max_files_per_process.
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/w6uiicyou7hzq47mbyejubtcyb2rngkkf45fk4q7inue5kfbeo@bbfad3qyubvs
Discussion: https://postgr.es/m/CAGECzQQh6VSy3KG4pN1d=h9J=D1rStFCMR+t7yh_Kwj-g87aLQ@mail.gmail.com
The bitmap heap scan skip fetch optimization skips fetching the heap
block when a page is set all-visible in the visibility map and no
columns from the table are needed to satisfy the query.
2b73a8cd33 and c3953226a0 changed the control flow of bitmap heap scan
to use the read stream API. The read stream API returns buffers
containing blocks to the user. To make this work with the skip fetch
optimization, we keep a count of the empty tuples we need to emit for
all the blocks skipped and only emit the empty tuples after processing
the next block fetched from the heap or at the end of the scan.
It's incorrect to recheck NULL tuples, so we must set `recheck` to false
before yielding control back to BitmapHeapNext(). This was done before
emitting any remaining empty tuples at the end of the scan but not for
empty tuples emitted during the scan. This meant that if a page fetched
from the heap did require recheck and set `recheck` to true and then we
emitted empty tuples for subsequent blocks, we would get wrong results.
Fix this by always setting `recheck` to false before emitting empty
tuples.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Tested-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/496f7acd-881c-4df3-9bd3-8f8534dfec26%40gmail.com
Introduce a new conflict type, multiple_unique_conflicts, to handle cases
where an incoming row during logical replication violates multiple UNIQUE
constraints.
Previously, the apply worker detected and reported only the first
encountered key conflict (insert_exists/update_exists), causing repeated
failures as each constraint violation needs to be handled one by one
making the process slow and error-prone.
With this patch, the apply worker checks all unique constraints upfront
once the first key conflict is detected and reports
multiple_unique_conflicts if multiple violations exist. This allows users
to resolve all conflicts at once by deleting all conflicting tuples rather
than dealing with them individually or skipping the transaction.
In the future, this will also allow us to specify different resolution
handlers for such a conflict type.
Add the stats for this conflict type in pg_stat_subscription_stats.
Author: Nisha Moond <nisha.moond412@gmail.com>
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Discussion: https://postgr.es/m/CABdArM7FW-_dnthGkg2s0fy1HhUB8C3ELA0gZX1kkbs1ZZoV3Q@mail.gmail.com
This field can be optionally set in a PlannedStmt through the planner
hook, giving extensions the possibility to assign an identifier related
to a computed plan. The backend is changed to report it in the backend
entry of a process running (including the extended query protocol), with
semantics and APIs to set or get it similar to what is used for the
existing query ID (introduced in the backend via 4f0b0966c8). The plan
ID is reset at the same timing as the query ID. Currently, this
information is not added to the system view pg_stat_activity; extensions
can access it through PgBackendStatus.
Some patches have been proposed to provide some features in the planning
area, where a plan identifier is used as a key to know the plan involved
(for statistics, plan storage and manipulations, etc.), and the point of
this commit is to provide an anchor in the backend that extensions can
rely on for future work. The reset of the plan identifier is
controlled by core and follows the same pattern as the query identifier
added in 4f0b0966c8.
The contents of this commit are extracted from a larger set proposed
originally by Lukas Fittl, that Sami Imseih has proposed as an
independent change, with a few tweaks sprinkled by me.
Author: Lukas Fittl <lukas@fittl.com>
Author: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAP53Pkyow59ajFMHGpmb1BK9WHDypaWtUsS_5DoYUEfsa_Hktg@mail.gmail.com
Discussion: https://postgr.es/m/CAA5RZ0vyWd4r35uUBUmhngv8XqeiJUkJDDKkLf5LCoWxv-t_pw@mail.gmail.com
During hot standby, ExpireAllKnownAssignedTransactionIds() and
ExpireOldKnownAssignedTransactionIds() functions mark old transactions
as no-longer running, but they failed to update xactCompletionCount
and latestCompletedXid. AFAICS it would not lead to incorrect query
results, because those functions effectively turn in-progress
transactions into aborted transactions and an MVCC snapshot considers
both as "not visible". But it could surprise GetSnapshotDataReuse()
and trigger the "TransactionIdPrecedesOrEquals(TransactionXmin,
RecentXmin))" assertion in it, if the apparent xmin in a backend would
move backwards. We saw this happen when GetCatalogSnapshot() would
reuse an older catalog snapshot, when GetTransactionSnapshot() had
already advanced TransactionXmin.
The bug goes back all the way to commit 623a9ba79b in v14 that
introduced the snapshot reuse mechanism, but it started to happen more
frequently with commit 952365cded which removed a
GetTransactionSnapshot() call from backend startup. That made it more
likely for ExpireOldKnownAssignedTransactionIds() to be called between
GetCatalogSnapshot() and the first GetTransactionSnapshot() in a
backend.
Andres Freund first spotted this assertion failure on buildfarm member
'skink'. Reproduction and analysis by Tomas Vondra.
Backpatch-through: 14
Discussion: https://www.postgresql.org/message-id/oey246mcw43cy4qw2hqjmurbd62lfdpcuxyqiu7botx3typpax%40h7o7mfg5zmdj
Add a new scheduling heuristic: don't end the ongoing primitive index
scan immediately (at the point where _bt_advance_array_keys notices that
the next set of matching tuples must be on a later page) if the primscan
already managed to step right/left from its first leaf page. Schedule a
recheck against the next sibling leaf page's finaltup instead.
The new heuristic tends to avoid scenarios where the top-level scan
repeatedly starts and ends primitive index scans that each read only one
leaf page from a group of neighboring leaf pages. Affected top-level
scans will now tend to step forward (or backward) through the index
instead, without wasting cycles on descending the index anew.
The recheck mechanism isn't exactly new. But up until now it has only
been used to deal with edge cases involving high key finaltups with one
or more truncated -inf attributes that _bt_advance_array_keys deemed
"provisionally satisfied" (satisfied for the purposes of allowing the
scan to step onto the next page, subject to recheck once on that page).
The mechanism was added by commit 5bf748b8, which invented the general
concept of primitive scan scheduling. It was later enhanced by commit
79fa7b3b, which taught it about cases involving -inf attributes that
satisfy inequality scan keys required in the opposite-to-scan direction
only (arguably, they should have been covered by the earliest version).
Now the recheck mechanism can be applied based on scan-level heuristics,
which have nothing to do with truncated high keys. Now rechecks might
be performed by _bt_readpage when scanning in _either_ scan direction.
The theory behind the new heuristic is that any primitive scan that
makes it past its first leaf page is one that is already likely to have
arrays whose key values match index tuples that are closely clustered
together in the index. The rules that determine whether we ever get
past the first page are still conservative (that'll still only happen
when pstate.finaltup strongly suggests that it's the right thing to do).
Surviving past the first leaf page is a strong signal in itself.
Preparation for an upcoming patch that will add skip scan optimizations
to nbtree. That'll work by adding skip arrays, which behave similarly
to SAOP arrays, but generate their elements procedurally and on-demand.
Note that this commit isn't specifically concerned with skip arrays; the
scheduling logic doesn't (and won't) condition anything on whether the
scan uses skip arrays, SAOP arrays, or some combination of the two
(which seems like a good general principle for _bt_advance_array_keys).
While the problems that this commit ameliorates are more likely with
skip arrays (at least in practice), SAOP arrays (or those with very
dense, contiguous array elements) are also affected.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com>
Discussion: https://postgr.es/m/CAH2-Wzkz0wPe6+02kr+hC+JJNKfGtjGTzpG3CFVTQmKwWNrXNw@mail.gmail.com
Like 69273b818b did for GiST vacuuming, make SP-GiST vacuum use the
read stream API for vacuuming physically contiguous index pages.
Concurrent insertions may cause SP-GiST index tuples to be redirected.
While vacuuming, these are added to a pending list which is later
processed to ensure no dead tuples are left behind. Pages containing
such tuples are still read by directly calling ReadBuffer() and do not
use the read stream API.
Author: Andrey M. Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/37432403-8657-403B-9CDF-5A642BECDD81%40yandex-team.ru
This code must have missed a memo about the backend type description
being supplied automatically these days, and was duplicating that
information.
Before: "io worker io worker: N"
After: "io worker N"
This commit introduces a new GUC option max_active_replication_origins
to control the maximum number of active replication
origins. Previously, this was controlled by
'max_replication_slots'. Having a separate GUC option provides better
flexibility for setting up subscribers, as they may not require
replication slots (for cascading replication) but always require
replication origins.
Author: Euler Taveira <euler@eulerto.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Discussion: https://postgr.es/m/b81db436-8262-4575-b7c4-bc0c1551000b@app.fastmail.com
Make genbki.pl emit some boilerplate comments identifying the
sections of the pg_*_d.h files that it generates. This is in
hopes of making them slightly more readable, in case people
look at those files and not the pg_*.h/pg_*.dat originals.
Discussion: https://postgr.es/m/1134562.1742507765@sss.pgh.pa.us
Like c5c239e26e did for btree vacuuming, make GiST vacuum use the
read stream API for sequentially processed pages.
Because it is possible for concurrent insertions to relocate unprocessed
index entries to already vacuumed pages, GiST vacuum must backtrack and
reprocess those pages. These pages are still read with explicit
ReadBuffer() calls.
Author: Andrey M. Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/EFEBED92-18D1-4C0F-A4EB-CD47072EF071%40yandex-team.ru
c5c239e26e made btree vacuum use the read stream API. Though it used
functions declared in read_stream.h, it relied on transitively including
it. Explicitly include that file. Also remove an extraneous newline and
decrease the scope of one of the local variables in btvacuumscan().
Btree vacuum processes all index pages in physical order. Now it uses
the read stream API to get the next buffer instead of explicitly
invoking ReadBuffer().
It is possible for concurrent insertions to cause page splits during
index vacuuming. This can lead to index entries that have yet to be
vacuumed being moved to pages that have already been vacuumed. Btree
vacuum code handles this by backtracking to reprocess those pages. So,
while sequentially encountered pages are now read through the
read stream API, backtracked pages are still read with explicit
ReadBuffer() calls.
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_bW1UOyup%3DjdFw%2BkOF9bCaAm%3D9UpiyZtbPMn8n_vnP%2Big%40mail.gmail.com#3b3a84132fc683b3ee5b40bc4c2ea2a5
All TupleDescAttr() calls in tablecmds.c that aren't in loops across all
attributes use AttrNumber-style indexes (1-based); there was only one
place in ATRewriteTable that was stashing 0-based indexes in a list for
later processing. Switch that to use attnums for consistency.
Author: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxEoYA5ScUr2=CmA1xcpaS_1ixneDbEkVU77X1ctGxY2mA@mail.gmail.com
StartReadBuffers() reports a short read when it finds a cached block
that ends a range needing I/O by updating the caller's *nblocks. It
doesn't want to have to unpin the trailing hit that it knows the caller
wants, so the v17 version used sleight of hand in the name of
simplicity: it included it in *nblocks as if it were part of the I/O,
but internally tracked the shorter real I/O size in io_buffers_len (now
removed).
This API change "forwards" the delimiting buffer to the next call. It's
still pinned, and still stored in the caller's array, but *nblocks no
longer includes stray buffers that are not really part of the operation.
The expectation is that the caller still wants the rest of the blocks
and will call again starting from that point, and now it can pass the
already pinned buffer back in (or choose not to and release it).
The change is needed for the coming asynchronous I/O version's larger
version of the problem: by definition it must move BM_IO_IN_PROGRESS
negotiation from WaitReadBuffers() to StartReadBuffers(), but it might
already have many buffers pinned before it discovers a need to split an
I/O. (The current synchronous I/O version hides that detail from
callers by looping over smaller reads if required to make all covered
buffers valid in WaitReadBuffers(), so it looks like one operation but
it might occasionally be several under the covers.)
Aside from avoiding unnecessary pin traffic, this will also be important
for later work on out-of-order streams: you can't prioritize data that
is already available right now if that fact is hidden from you.
The new API is natural for read_stream.c (see ed0b87ca). After a short
read it leaves forwarded buffers where they fell in its circular queue
for the continuing call to pick up.
Single-block StartReadBuffer() and traditional ReadBuffer() share code
but are not affected by the change. They don't do multi-block I/O.
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier versions)
Discussion: https://postgr.es/m/CA%2BhUKGK_%3D4CVmMHvsHjOVrK6t4F%3DLBpFzsrr3R%2BaJYN8kcTfWg%40mail.gmail.com
In preparation for a follow-up change to the buffer manager, teach
read_stream.c to manage buffers "forwarded" from one StartReadBuffers()
call to the next after a short read. This involves a small amount of
extra book-keeping, and opens the way for lower levels to split I/O
operations without having to drop pins, as required for efficient
handling of various edge cases.
Concretely, the "buffers" argument will change from an out parameter to
an in/out parameter. Buffer queue elements must be initialized on first
use and cleared after they're consumed, but forwarded buffers are left
where they fall ahead of the current pending read in the queue, ready
for use by the operation that continues where a short read left off.
The stream also needs to count them for pin limit management and release
them on reset/early end.
Tested-by: Andres Freund <andres@anarazel.de> (earlier versions)
Discussion: https://postgr.es/m/CA%2BhUKGK_%3D4CVmMHvsHjOVrK6t4F%3DLBpFzsrr3R%2BaJYN8kcTfWg%40mail.gmail.com
This removes a needless special case for Memoize's FORMAT TEXT EXPLAIN
output.
ExplainPropertyText() outputs the same thing in text mode as the
special-case code was doing, so removing the special-case code results in
the same EXPLAIN output, just with less code.
It seems like a good idea to fix this to help prevent future changes in
this area from copying the same pattern.
Author: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
Reported-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/88a71bcd-0b5c-4d0b-8107-757e96f402d5@tantorlabs.com
Previously we would have the following inaccuracies when a backend tried to
read in a buffer, but that buffer was read in concurrently by another backend:
- the read IO was double-counted in the global buffer access stats (pgBufferUsage)
- the buffer hit was not accounted for in:
- global buffer access statistics
- pg_stat_io
- relation level IO stats
- vacuum cost balancing
While trying to read in a buffer that is concurrently read in by another
backend is not a common occurrence, it's also not that rare, e.g. due to
concurrent sequential scans on the same relation. This scenario has become
more likely in PG 17, due to the introducing of read streams, which can pin
multiple buffers before calling StartBufferIO() for all the buffers.
This behaviour has historically grown, but there doesn't seem to be any reason
to continue with the wrong accounting.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CAAKRu_Zk-B08AzPsO-6680LUHLOCGaNJYofaxTFseLa=OepV1g@mail.gmail.com
We need to hold interrupts across most of the smgr.c/md.c functions, as
otherwise interrupt processing, e.g. due to a < ERROR elog/ereport, can
trigger procsignal processing, which in turn can trigger smgrreleaseall(). As
the relevant code is not reentrant, we quickly end up in a bad situation.
The only reason we haven't noticed this before is that there is only one
non-error ereport called in affected routines, in register_dirty_segments(),
and that one is extremely rarely reached. If one enables fd.c's FDDEBUG it's
easy to reproduce crashes.
It seems better to put the HOLD_INTERRUPTS()/RESUME_INTERRUPTS() in smgr.c,
instead of trying to push them down to md.c where possible: For one, every
smgr implementation would be vulnerable, for another, a good bit of smgr.c
code itself is affected too.
Eventually we might want a more targeted solution, allowing e.g. a networked
smgr implementation to be interrupted, but many other, more complicated,
problems would need to be fixed for that to be viable (e.g. smgr.c is often
called with interrupts already held).
One could argue this should be backpatched, but the existing < ERROR
elog/ereports that can be reached with unmodified sources are unlikely to be
reached. On balance the risk of backpatching seems higher than the gain - at
least for now.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/3vae7l5ozvqtxmd7rr7zaeq3qkuipz365u3rtim5t5wdkr6f4g@vkgf2fogjirl
Commit c65bc2e1d1 made it possible for
loadable modules to add EXPLAIN options. Normally, any necessary
validation can be performed by the hook function passed to
RegisterExtensionExplainOption, but if a loadable module wants to sanity
check options against each other, that needs to be done after the entire
options list has been processed. So, add an additional hook for that
purpose.
Author: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: http://postgr.es/m/CAA5RZ0vOcJF91O2e5AQN+V6guMNLMhJx83dxALf-iUZ-hLGO_Q@mail.gmail.com
This new parameter works just like the storage parameter of the
same name: if set to true (which is the default), autovacuum and
VACUUM attempt to truncate any empty pages at the end of the table.
It is primarily intended to help users avoid locking issues on hot
standbys. The setting can be overridden with the storage parameter
or VACUUM's TRUNCATE option.
Since there's presently no way to determine whether a Boolean
storage parameter is explicitly set or has just picked up the
default value, this commit also introduces an isset_offset member
to relopt_parse_elt.
Suggested-by: Will Storey <will@summercat.com>
Author: Nathan Bossart <nathandbossart@gmail.com>
Co-authored-by: Gurjeet Singh <gurjeet@singh.im>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Discussion: https://postgr.es/m/Z2DE4lDX4tHqNGZt%40dev.null
The comment explained that ALTER TABLE ADD CONSTRAINT USING INDEX is
only supported with a btree index. (This is not being changed.) The
reason is to keep upgrades robust, as explained there. The other part
of the comment, that btree is the only unique index kind anyway, is
somewhat less true as we're trying to enable unique indexes other than
btree, and it's irrelevant to this check. There is a check for
indisunique earlier already. So just remove this part of the comment.
Author: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
