Clang 21 shows some new compiler warnings, for example:
warning: variable 'dstsize' is uninitialized when passed as a const pointer argument here [-Wuninitialized-const-pointer]
The fix is to initialize the variables when they are defined. This is
similar to, for example, the existing situation in gistKeyIsEQ().
Discussion: https://www.postgresql.org/message-id/flat/6604ad6e-5934-43ac-8590-15113d6ae4b1%40eisentraut.org
pg_event_trigger_dropped_objects() would report a column default
object with is_temporary = false, even if it belongs to a
temporary table. This seems clearly wrong, so adjust it to
report the table's temp-ness.
While here, refactor EventTriggerSQLDropAddObject to make its
handling of namespace objects less messy and avoid duplication
of the schema-lookup code. And add some explicit test coverage
of dropped-object reports for dependencies of temp tables.
Back-patch to v15. The bug exists further back, but the
GetAttrDefaultColumnAddress function this patch depends on does not,
and it doesn't seem worth adjusting it to cope with the older code.
Author: Antoine Violin <violin.antuan@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFjUV9x3-hv0gihf+CtUc-1it0hh7Skp9iYFhMS7FJjtAeAptA@mail.gmail.com
Backpatch-through: 15
hash_xlog.h included descriptions for the blocks used in WAL records
that were was not completely consistent with how the records are
generated, with one block missing for SQUEEZE_PAGE, and inconsistent
descriptions used for block 0 in VACUUM_ONE_PAGE and MOVE_PAGE_CONTENTS.
This information was incorrect since c11453ce0a, cross-checking the
logic for the record generation.
Author: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/CALdSSPj1j=a1d1hVA3oabRFz0hSU3KKrYtZPijw4UPUM7LY9zw@mail.gmail.com
Backpatch-through: 13
If the hash functions used for hashing tuples leaked any memory,
we failed to clean that up, resulting in query-lifespan memory
leakage in queries using hashed subplans. One way that could
happen is if the values being hashed require de-toasting, since
most of our hash functions don't trouble to clean up de-toasted
inputs.
Prior to commit bf6c614a2, this leakage was largely masked
because TupleHashTableMatch would reset hashtable->tempcxt
(via execTuplesMatch). But it doesn't do that anymore, and
that's not really the right place for this anyway: doing it
there could reset the tempcxt many times per hash lookup,
or not at all. Instead put reset calls into ExecHashSubPlan
and buildSubPlanHash. Along the way to that, rearrange
ExecHashSubPlan so that there's just one place to call
MemoryContextReset instead of several.
This amounts to accepting the de-facto API spec that the caller
of the TupleHashTable routines is responsible for resetting the
tempcxt adequately often. Although the other callers seem to
get this right, it was not documented anywhere, so add a comment
about it.
Bug: #19040
Reported-by: Haiyang Li <mohen.lhy@alibaba-inc.com>
Author: Haiyang Li <mohen.lhy@alibaba-inc.com>
Reviewed-by: Fei Changhong <feichanghong@qq.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19040-c9b6073ef814f48c@postgresql.org
Backpatch-through: 13
The startup process does not process shared invalidation messages, only
sending them, and never calls AtEOXact_SMgr() which clean up any
unpinned SMgrRelations. Hence, it is never able to free SMgrRelations
on a periodic basis, bloating its hashtable over time.
Like the checkpointer and the bgwriter, this commit takes a conservative
approach by freeing periodically SMgrRelations when replaying a
checkpoint record, either online or shutdown, so as the startup process
has a way to perform a periodic cleanup.
Issue caused by 21d9c3ee4e, so backpatch down to v17.
Author: Jingtang Zhang <mrdrivingduck@gmail.com>
Reviewed-by: Yuhang Qiu <iamqyh@gmail.com>
Discussion: https://postgr.es/m/28C687D4-F335-417E-B06C-6612A0BD5A10@gmail.com
Backpatch-through: 17
A new pgstats entry is created as a two-step process:
- The entry is looked at in the shared hashtable of pgstats, and is
inserted if not found.
- When not found and inserted, its fields are then initialized. This
part include a DSA chunk allocation for the stats data of the new entry.
As currently coded, if the DSA chunk allocation fails due to an
out-of-memory failure, an ERROR is generated, leaving in the pgstats
shared hashtable an inconsistent entry due to the first step, as the
entry has already been inserted in the hashtable. These broken entries
can then be found by other backends, crashing them.
There are only two callers of pgstat_init_entry(), when loading the
pgstats file at startup and when creating a new pgstats entry. This
commit changes pgstat_init_entry() so as we use dsa_allocate_extended()
with DSA_ALLOC_NO_OOM, making it return NULL on allocation failure
instead of failing. This way, a backend failing an entry creation can
take appropriate cleanup actions in the shared hashtable before throwing
an error. Currently, this means removing the entry from the shared
hashtable before throwing the error for the allocation failure.
Out-of-memory errors unlikely happen in the wild, and we do not bother
with back-patches when these are fixed, usually. However, the problem
dealt with here is a degree worse as it breaks the shared memory state
of pgstats, impacting other processes that may look at an inconsistent
entry that a different process has failed to create.
Author: Mikhail Kot <mikhail.kot@databricks.com>
Discussion: https://postgr.es/m/CAAi9E7jELo5_-sBENftnc2E8XhW2PKZJWfTC3i2y-GMQd2bcqQ@mail.gmail.com
Backpatch-through: 15
When executing a MERGE UPDATE action, if there is more than one
concurrent update of the target row, the lock-and-retry code would
sometimes incorrectly identify the latest version of the target tuple,
leading to incorrect results.
This was caused by using the ctid field from the TM_FailureData
returned by table_tuple_lock() in a case where the result was TM_Ok,
which is unsafe because the TM_FailureData struct is not guaranteed to
be fully populated in that case. Instead, it should use the tupleid
passed to (and updated by) table_tuple_lock().
To reduce the chances of similar errors in the future, improve the
commentary for table_tuple_lock() and TM_FailureData to make it
clearer that table_tuple_lock() updates the tid passed to it, and most
fields of TM_FailureData should not be relied on in non-failure cases.
An exception to this is the "traversed" field, which is set in both
success and failure cases.
Reported-by: Dmitry <dsy.075@yandex.ru>
Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/1570d30e-2b95-4239-b9c3-f7bf2f2f8556@yandex.ru
Backpatch-through: 15
If an INSERT has an ON CONFLICT DO UPDATE clause, the executor must
check that the target relation supports UPDATE as well as INSERT. In
particular, it must check that the target relation has a REPLICA
IDENTITY if it publishes updates. Formerly, it was not doing this
check, which could lead to silently breaking replication.
Fix by adding such a check to CheckValidResultRel(), which requires
adding a new onConflictAction argument. In back-branches, preserve ABI
compatibility by introducing a wrapper function with the original
signature.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Tested-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/OS3PR01MB57180C87E43A679A730482DF94B62@OS3PR01MB5718.jpnprd01.prod.outlook.com
Backpatch-through: 13
The counters saved from pgWalUsage, used for the difference calculations
when flushing the backend WAL stats, are updated when calling
pgstat_flush_backend() under PGSTAT_BACKEND_FLUSH_WAL, and not
pgstat_report_wal(). The comment updated in this commit referenced the
latter, but it is perfectly OK to flush the backend stats independently
of the WAL stats.
Noticed while looking at this area of the code, introduced by
76def4cdd7 as a copy-pasto.
Backpatch-through: 18
SubPlan nodes are typically built very early, before any RelOptInfos
have been constructed for the parent query level. As a result, the
simple_rel_array in the parent root has not yet been initialized.
Currently, during cost estimation of a SubPlan's testexpr, we may call
examine_variable() to look up statistical data about the expressions.
This can lead to "no relation entry for relid" errors.
To fix, pass root as NULL to cost_qual_eval() in cost_subplan(), since
the root does not yet contain enough information to safely consult
statistics.
One exception is SubPlan nodes built for the initplans of MIN/MAX
aggregates from indexes. In this case, having a NULL root is safe
because testexpr will be NULL. Additionally, an initplan will by
definition not consult anything from the parent plan.
Backpatch to all supported branches. Although the reported call path
that triggers this error is not reachable prior to v17, there's no
guarantee that other code paths -- especially in extensions -- could
not encounter the same issue when cost_qual_eval() is called with a
root that lacks a valid simple_rel_array. The test case is not
included in pre-v17 branches though.
Bug: #19037
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19037-3d1c7bb553c7ce84@postgresql.org
Backpatch-through: 13
PQtrace() was generating its output for non-printable characters without
casting the characters printed with unsigned char, leading to some extra
"\xffffff" generated in the output due to the fact that char may be
signed.
Oversights introduced by commit 198b3716db, so backpatch down to v14.
Author: Ran Benita <ran@unusedvar.com>
Discussion: https://postgr.es/m/a3383211-4539-459b-9d51-95c736ef08e0@app.fastmail.com
Backpatch-through: 14
SLRU bank locks are referred as "bank locks" or "SLRU bank locks" in the
code comments. The comments updated in this commit use the latter term.
Oversight in 53c2a97a92, that has replaced the single ControlLock by
the bank control locks.
Author: Julien Rouhaud <julien.rouhaud@free.fr>
Discussion: https://postgr.es/m/aLUT2UO8RjJOzZNq@jrouhaud
Backpatch-through: 17
Compression in pg_dump is abstracted using an API with multiple
implementations which can be selected at runtime by the user.
The API and its implementations have evolved over time, notable
commits include bf9aa490db, e9960732a9, 84adc8e20, and 0da243fed.
The errorhandling defined by the API was however problematic and
the implementations had a few bugs and/or were not following the
API specification. This commit modifies the API to ensure that
callers can perform errorhandling efficiently and fixes all the
implementations such that they all implement the API in the same
way. A full list of the changes can be seen below.
* write_func:
- Make write_func throw an error on all error conditions. All
callers of write_func were already checking for success and
calling pg_fatal on all errors, so we might as well make the
API support that case directly with simpler errorhandling as
a result.
* open_func:
- zstd: move stream initialization from the open function to
the read and write functions as they can have fatal errors.
Also ensure to dup the file descriptor like none and gzip.
- lz4: Ensure to dup the file descriptor like none and gzip.
* close_func:
- zstd: Ensure to close the file descriptor even if closing
down the compressor fails, and clean up state allocation on
fclose failures. Make sure to capture errors set by fclose.
- lz4: Ensure to close the file descriptor even if closing
down the compressor fails, and instead of calling pg_fatal
log the failures using pg_log_error. Make sure to capture
errors set by fclose.
- none: Make sure to catch errors set by fclose.
* read_func / gets_func:
- Make read_func unconditionally return the number of read
bytes instead of making it optional per implementation.
- lz4: Make sure to call throw an error and not return -1
- gzip: gzread returning zero cannot be assumed to indicate
EOF as it is documented to return zero for some types of
errors.
- lz4, zstd: Convert the _read_internal helper functions to
not call pg_fatal on errors to be able to handle gets_func
returning NULL on error.
* getc_func:
- zstd: Use an unsigned char rather than an int to read char
into.
* LZ4Stream_init:
- Make sure to not switch to inited state until we know that
initialization succeeded and reset errno just in case.
On top of these changes there are minor comment cleanups and
improvements as well as an attempt to consistently reset errno
in codepaths where it is inspected.
This work was initiated by a report of API misuse, which turned
into a larger body of work. As this is an internal API these
changes can be backpatched into all affected branches.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Daniel Gustafsson <daniel@yesql.se>
Reported-by: Evgeniy Gorbanev <gorbanyoves@basealt.ru>
Discussion: https://postgr.es/m/517794.1750082166@sss.pgh.pa.us
Backpatch-through: 16
It's possible that if the only live partition is concurrently dropped
and try_table_open() fails, that the bms_del_member() will pfree the
live_parts Bitmapset. Since the bms_del_member() call does not assign
the result back to the live_parts local variable, the while loop could
segfault as that variable would still reference the pfree'd Bitmapset.
Backpatch to 15. 52f3de874 was backpatched to 14, but there's no
bms_del_member() there due to live_parts not yet existing in RelOptInfo in
that version. Technically there's no bug in version 15 as
bms_del_member() didn't pfree when the set became empty prior to
00b41463c (from v16). Applied to v15 anyway to keep the code similar and
to avoid the bad coding pattern.
Author: Bernd Reiß <bd_reiss@gmx.at>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/6b88f27a-c45c-4826-8e37-d61a04d90182@gmx.at
Backpatch-through: 15
For a child relation, we should not assume that its parent's
unique-ified relation (or unique-ified path in v18) always exists. In
cases where all RHS columns that need to be unique-ified are equated
to constants, the unique-ified relation/path for the parent table is
not built, as there are no columns left to unique-ify. Failing to
account for this can result in a SIGSEGV crash during planning.
This patch checks whether the parent's unique-ified relation or path
exists and skips unique-ification of the child relation if it does
not.
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49MOdLW2c+qbLHHBt8VBu=4ONpM91D19=AWeW93eFUF6A@mail.gmail.com
Backpatch-through: 18
One mechanism we have for implementing semi-joins is to de-duplicate
the output of the RHS and then treat the join as a plain inner join.
Initial construction of the join's SpecialJoinInfo identifies the
RHS columns that need to be de-duplicated, but later we may find that
some of those don't need to be handled explicitly, either because
they're known to be constant or because they are redundant with some
previous column.
Up to now, while sort-based de-duplication handled such cases well,
hash-based de-duplication didn't: we'd still hash on all of the
originally-identified columns. This is probably not a very big
deal performance-wise, but in the wake of commit a3179ab69 it can
cause planner errors. That happens when join elimination causes
recalculation of variables' attr_needed bitmapsets, and we decide
that a variable mentioned in a semijoin clause doesn't need to be
propagated up to the join level anymore.
There are a number of ways we could slice the blame for this, but the
only fix that doesn't result in pessimizing plans for loosely-related
cases is to be more careful about not hashing columns we don't
actually need to de-duplicate. We can install that consideration
into create_unique_paths in master, or the predecessor code in
create_unique_path in v18, without much refactoring.
(As follow-up work, it might be a good idea to look at more-invasive
refactoring, in hopes of preventing other bugs in this area. But
with v18 release so close, there's not time for that now, nor would
we be likely to want to put such refactoring into v18 anyway.)
Reported-by: Sergey Soloviev <sergey.soloviev@tantorlabs.ru>
Diagnosed-by: Richard Guo <guofenglinux@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/1fd1a421-4609-4d46-a1af-ab74d5de504a@tantorlabs.ru
Backpatch-through: 18
During an investigation into rather odd aio related errors on macos, observed
by Alexander and Konstantin, we started to wonder if bitfield access is
related to the error. At the moment it looks like it is related, we cannot
reproduce the failures when replacing the bitfields. In addition, the problem
can only be reproduced with some compiler [versions] and not everyone has been
able to reproduce the issue.
The observed problem is that, very rarely, PgAioHandle->{state,target} are in
an inconsistent state, after having been checked to be in a valid state not
long before, triggering an assertion failure. Unfortunately, this could be
caused by wrong compiler code generation or somehow of missing memory barriers
- we don't really know. In theory there should not be any concurrent write
access to the handle in the state the bug is triggered, as the handle was idle
and is just being initialized.
Separately from the bug, we observed that at least gcc and clang generate
rather terrible code for the bitfield access. Even if it's not clear if the
observed assertion failure is actually caused by the bitfield somehow, the bad
code generation alone is sufficient reason to stop using bitfields.
Therefore, replace the enum bitfields with uint8s and instead cast in each
switch statement.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reported-by: Konstantin Knizhnik <knizhnik@garret.ru>
Discussion: https://postgr.es/m/1500090.1745443021@sss.pgh.pa.us
Backpatch-through: 18
This patch fixes a bug in how 'load_external_function' handles
'$libdir/ prefixes in module paths.
Previously, 'load_external_function' would unconditionally strip
'$libdir/' from the beginning of the 'filename' string. This caused
an issue when the path was nested, such as "$libdir/nested/my_lib".
Stripping the prefix resulted in a path of "nested/my_lib", which
would fail to be found by the expand_dynamic_library_name function
because the original '$libdir' macro was removed.
To fix this, the code now checks for the presence of an additional
directory separator ('/' or '\') after the '$libdir/' prefix. The
prefix is only stripped if the remaining string does not contain a
separator. This ensures that simple filenames like '"$libdir/my_lib"'
are correctly handled, while nested paths are left intact for
'expand_dynamic_library_name' to process correctly.
Reported-by: Dilip Kumar <dilipbalaut@gmail.com>
Co-authored-by: Matheus Alcantara <matheusssilv97@gmail.com>
Co-authored-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAFiTN-uKNzAro4tVwtJhF1UqcygfJ%2BR%2BRL%3Db-_ZMYE3LdHoGhA%40mail.gmail.com
When checking for expression indexes that may be affected by a Unicode
update during upgrade, check for a few more functions. Specifically,
check for documented regexp functions, as well as the new CASEFOLD()
function.
Also, fully-qualify references to pg_catalog.text and
pg_catalog.regtype.
Discussion: https://postgr.es/m/399b656a3abb0c9283538a040f72199c0601525c.camel@j-davis.com
Backpatch-through: 18
When vacuumdb's --missing-stats-only option is used, the catalog
query for retrieving the list of relations to process must read
pg_statistic and pg_statistic_ext_data. However, those catalogs
can only be read by superusers by default, so --missing-stats-only
is effectively superuser-only. This is unfortunate, but since the
option is primarily intended for use by administrators after
running pg_upgrade, let's just live with it for v18. This commit
adds a note about the aforementioned privilege requirements to the
documentation for --missing-stats-only.
We first tried to improve matters by modifying the query to read
the pg_stats and pg_stats_ext system views instead. While that is
indeed more lenient from a privilege standpoint, it is also
borderline incomprehensible. pg_stats shows rows for which the
user has the SELECT privilege on the corresponding column, and
pg_stats_ext shows rows for tables the user owns. Meanwhile,
ANALYZE requires either MAINTAIN on the table or, for non-shared
relations, ownership of the database. But even if the privilege
discrepancies were tolerable, the performance impact was not.
Ultimately, the modified query was substantially more expensive, so
we abandoned the idea.
For v19, perhaps we could introduce a simple, inexpensive way to
discover which relations are missing statistics, such as a system
function or view with similar privilege requirements to ANALYZE.
Unfortunately, it is far too late for anything like that in v18.
Reviewed-by: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwHh43suEfss1wvBsk7vqiou%3DUY0zcy8HGyE5hBp%2BHZ7SQ%40mail.gmail.com
Backpatch-through: 18
Commit 4b754d6c1 introduced the concept of an excludeOnly scan key,
which cannot select matching index entries but can reject
non-matching tuples, for example a tsquery such as '!term'. There are
poorly-documented assumptions that such scan keys do not appear as the
first scan key. ginNewScanKey did nothing to ensure that, however,
with the result that certain GIN index searches could go into an
infinite loop while apparently-equivalent queries with the clauses in
a different order were fine.
Fix by teaching ginNewScanKey to place all excludeOnly scan keys
after all not-excludeOnly ones. So far as we know at present,
it might be sufficient to avoid the case where the very first
scan key is excludeOnly; but I'm not very convinced that there
aren't other dependencies on the ordering.
Bug: #19031
Reported-by: Tim Wood <washwithcare@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19031-0638148643d25548@postgresql.org
Backpatch-through: 13
The CHECK_FOR_INTERRUPTS call in gingetbitmap turns out to be
inadequate to prevent a long uninterruptible loop, because
we now know a case where looping occurs within scanGetItem.
While the next patch will fix the bug that caused that, it
seems foolish to assume that no similar patterns are possible.
Let's do the CFI within scanGetItem's retry loop, instead.
This demonstrably allows canceling out of the loop exhibited
in bug #19031.
Bug: #19031
Reported-by: Tim Wood <washwithcare@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19031-0638148643d25548@postgresql.org
Backpatch-through: 13
The Self-Join Elimination SJE feature messes up keeping and removing RowMark's
in remove_self_joins_one_group(). That didn't lead to user-level error,
because the planned RowMark is only used to reference a rtable entry in later
execution stages. An RTE entry for keeping and removing relations is
identical and refers to the same relation OID.
To reduce confusion and prevent future issues, this commit cleans up the code
and fixes the incorrect behaviour. Furthermore, it includes sanity checks in
setrefs.c on existing non-null RTE and RelOptInfo entries for each RowMark.
Discussion: https://postgr.es/m/18c6bd6c-6d2a-419a-b0da-dfedef34b585%40gmail.com
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Greg Sabino Mullane <htamfids@gmail.com>
Backpatch-through: 18
libpq-oauth uses floor() but did not link against libm. Since libpq
itself uses -lm, nothing in the buildfarm has had problems with
libpq-oauth yet, and it seems difficult to hit a failure in practice.
But commit 1443b6c0e attempted to add an executable based on
libpq-oauth, which ran into link-time failures with Clang due to this
omission. It seems prudent to fix this for both the module and the
executable simultaneously so that no one trips over it in the future.
This is a Makefile-only change. The Meson side already pulls in libm,
through the os_deps dependency.
Discussion: https://postgr.es/m/CAOYmi%2Bn6ORcmV10k%2BdAs%2Bp0b9QJ4bfpk0WuHQaF5ODXxM8Y36A%40mail.gmail.com
Backpatch-through: 18
