Up to now, index amhandlers were expected to produce a new, palloc'd
struct on each call. That requires palloc/pfree overhead, and creates
a risk of memory leaks if the caller fails to pfree, and the time
taken to fill such a large structure isn't nil. Moreover, we were
storing these things in the relcache, eating several hundred bytes for
each cached index. There is not anything in these structs that needs
to vary at runtime, so let's change the definition so that an
amhandler can return a pointer to a "static const" struct of which
there's only one copy per index AM. Mark all the core code's
IndexAmRoutine pointers const so that we catch anyplace that might
still try to change or pfree one.
(This is similar to the way we were already handling TableAmRoutine
structs. This commit does fix one comment that was infelicitously
copied-and-pasted into tableamapi.c.)
This commit needs to be called out in the v19 release notes as an API
change for extension index AMs. An un-updated AM will still work
(as of now, anyway) but it risks memory leaks and will be slower than
necessary.
Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAEoWx2=vApYk2LRu8R0DdahsPNEhWUxGBZ=rbZo1EXE=uA+opQ@mail.gmail.com
This commit adds the total memory allocated during vacuum, the number
of times the dead items storage was reset, and the configured memory
limit. This helps users understand how much memory VACUUM required,
and such information can be used to avoid multiple index scans.
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAHza6qcPitBCkyiKJosDTt3bmxMvzZOTONoebwCkBZrr3rk65Q%40mail.gmail.com
Previously, ReplicationSlotsComputeRequiredXmin() computed the oldest
xmin across all slots without holding ProcArrayLock (when
already_locked is false), acquiring the lock just before updating the
replication slot xmin.
This could lead to a race condition: if a backend created a new slot
and updates the global replication slot xmin, another backend
concurrently running ReplicationSlotsComputeRequiredXmin() could
overwrite that update with an invalid or stale value. This happens
because the concurrent backend might have computed the aggregate xmin
before the new slot was accounted for, but applied the update after
the new slot had already updated the global value.
In the reported failure, a walsender for an apply worker computed
InvalidTransactionId as the oldest xmin and overwrote a valid
replication slot xmin value computed by a walsender for a tablesync
worker. Consequently, the tablesync worker computed a transaction ID
via GetOldestSafeDecodingTransactionId() effectively without
considering the replication slot xmin. This led to the error "cannot
build an initial slot snapshot as oldest safe xid %u follows
snapshot's xmin %u", which was an assertion failure prior to commit
240e0dbacd.
To fix this, we acquire ReplicationSlotControlLock in exclusive mode
during slot creation to perform the initial update of the slot
xmin. In ReplicationSlotsComputeRequiredXmin(), we hold
ReplicationSlotControlLock in shared mode until the global slot xmin
is updated in ProcArraySetReplicationSlotXmin(). This prevents
concurrent computations and updates of the global xmin by other
backends during the initial slot xmin update process, while still
permitting concurrent calls to ReplicationSlotsComputeRequiredXmin().
Backpatch to all supported versions.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Pradeep Kumar <spradeepkumar29@gmail.com>
Reviewed-by: Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1L8wYcyTPxNzPGkhuO52WBGoOZbT0A73Le=ZUWYAYmdfw@mail.gmail.com
Backpatch-through: 14
We currently require LLVM 14, so these probes for LLVM 9 functions
always succeeded. Even when the features aren't enabled in an LLVM
build, dummy functions are defined (a problem for a later commit).
The whole PGAC_CHECK_LLVM_FUNCTIONS macro and Meson equivalent are
removed, because we switched to testing LLVM_VERSION_MAJOR at compile
time in subsequent work and these were the last holdouts. That suits
the nature of LLVM API evolution better, and also allows for strictly
mechanical pruning in future commits like 820b5af7 and 972c2cd2. They
advanced the minimum LLVM version but failed to spot these.
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKGJgB6gvrdDohgwLfCwzVQm%3DVMtb9m0vzQn%3DCwWn-kwG9w%40mail.gmail.com
This new function exposes at SQL level some information related to
multixacts, not available until now. This data is useful for monitoring
purposes, especially for workloads that make a heavy use of multixacts:
- num_mxids, number of MultiXact IDs in use.
- num_members, number of member entries in use.
- members_size, bytes used by num_members in pg_multixact/members/.
- oldest_multixact: oldest MultiXact still needed.
This patch has been originally proposed when MultiXactOffset was still
32 bits, to monitor wraparound. This part is not relevant anymore since
bd8d9c9bdf that has widen MultiXactOffset to 64 bits. The monitoring
of disk space usage for the members is still relevant.
Some tests are added to check this function, in the shape of one
isolation test with concurrent transactions that take a ROW SHARE lock,
and some SQL tests for pg_read_all_stats. Some documentation is added
to explain some patterns that can come from the information provided by
the function.
Bump catalog version.
Author: Naga Appani <nagnrik@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Discussion: https://postgr.es/m/CA+QeY+AAsYK6WvBW4qYzHz4bahHycDAY_q5ECmHkEV_eB9ckzg@mail.gmail.com
This function calculates in bytes the storage taken between two
multixact offsets. This will be used in an upcoming patch, introduced
separately here as this piece can be useful on its own.
Author: Naga Appani <nagnrik@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aUyTvZMq2CLgNEB4@paquier.xyz
This routine returned a number of members as a MultiXactOffset,
calculated based on the difference between the next-to-be-assigned
offset and the oldest offset. However, this number is not actually an
offset but a number.
This type confusion comes from the original implementation of
MultiXactMemberFreezeThreshold(), in 53bb309d2d. The number of
members is now defined as a uint64, large enough for MultiXactOffset.
This change will be used in a follow-up patch.
Reviewed-by: Naga Appani <nagnrik@gmail.com>
Discussion: https://postgr.es/m/aUyTvZMq2CLgNEB4@paquier.xyz
REL_18_STABLE and master have commit ee485912, so they always use the
newer LLVM opaque pointer functions. Drop -Wno-deprecated-declarations
(commit a56e7b660) for code under jit/llvm in those branches, to catch
any new deprecation warnings that arrive in future version of LLVM.
Older branches continued to use functions marked deprecated in LLVM 14
and 15 (ie switched to the newer functions only for LLVM 16+), as a
precaution against unforeseen compatibility problems with bitcode
already shipped. In those branches, the comment about warning
suppression is updated to explain that situation better. In theory we
could suppress warnings only for LLVM 14 and 15 specifically, but that
isn't done here.
Backpatch-through: 14
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1407185.1766682319%40sss.pgh.pa.us
estimate_hash_bucket_stats is defined to return zero to *mcv_freq if
it cannot obtain a value for the frequency of the most common value.
Its sole caller final_cost_hashjoin ignored this provision and would
blindly believe the zero value, resulting in computing zero for the
largest bucket size. In consequence, the safety check that intended
to prevent the largest bucket from exceeding get_hash_memory_limit()
was ineffective, allowing very silly plans to be chosen if statistics
were missing.
After fixing final_cost_hashjoin to disregard zero results for
mcv_freq, a second problem appeared: some cases that should use hash
joins failed to. This is because estimate_hash_bucket_stats was
unaware of the fact that ANALYZE won't store MCV statistics if it
doesn't find any multiply-occurring values. Thus the lack of an MCV
stats entry doesn't necessarily mean that we know nothing; we may
well know that the column is unique. The former coding returned zero
for *mcv_freq in this case, which was pretty close to correct, but now
final_cost_hashjoin doesn't believe it and disables the hash join.
So check to see if there is a HISTOGRAM stats entry; if so, ANALYZE
has in fact run for this column and must have found it to be unique.
In that case report the MCV frequency as 1 / rows, instead of claiming
ignorance.
Reporting a more accurate *mcv_freq in this case can also affect the
bucket-size skew adjustment further down in estimate_hash_bucket_stats,
causing hash-join cost estimates to change slightly. This affects
some plan choices in the core regression tests. The first diff in
join.out corresponds to a case where we have no stats and should not
risk a hash join, but the remaining changes are caused by producing
a better bucket-size estimate for unique join columns. Those are all
harmless changes so far as I can tell.
The existing behavior was introduced in commit 4867d7f62 in v11.
It appears from the commit log that disabling the bucket-size safety
check in the absence of statistics was intentional; but we've now seen
a case where the ensuing behavior is bad enough to make that seem like
a poor decision. In any case the lack of other problems with that
safety check after several years helps to justify enforcing it more
strictly. However, we won't risk back-patching this, in case any
applications are depending on the existing behavior.
Bug: #19363
Reported-by: Jinhui Lai <jinhui.lai@qq.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/2380165.1766871097@sss.pgh.pa.us
Discussion: https://postgr.es/m/19363-8dd32fc7600a1153@postgresql.org
This patch causes one postgres_fdw test case to revert to the plan
it used before aa86129e1, i.e., using a remote sort in preference to
local sort. That decision is actually a coin-flip because cost_sort()
will give the same answer on both sides, so that the plan choice comes
down to little more than roundoff error. In consequence, the test
output can change as a result of even minor changes in nearby costs,
as we saw in aa86129e1 (compare also b690e5fac and 4b14e1871).
b690e5fac's solution to stabilizing the adjacent test case was to
disable sorting locally, and here we extend that to the currently-
problematic case. Without this, the following patch would cause this
plan choice to change back in this same way, for even less apparent
reason.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/2551253.1766952956@sss.pgh.pa.us
Mkvcbuild.pm scrapes Makefile contents, but couldn't understand the
change made by commit bec2a0aa. Revealed by BF animal hamerkop in
branch REL_16_STABLE.
1. It used += instead of =, which didn't match the pattern that
Mkvcbuild.pm looks for. Drop the +.
2. Mkvcbuild.pm doesn't link PROGRAM executables with libpgport. Apply
a local workaround to REL_16_STABLE only (later branches dropped
Mkvcbuild.pm).
Backpatch-through: 16
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/175163.1766357334%40sss.pgh.pa.us
When looking up statistical data about an expression, we failed to
look through PlaceHolderVar nodes, treating them as opaque. This
could prevent us from matching an expression to base columns, index
expressions, or extended statistics, as examine_variable() relies on
strict structural matching.
As a result, queries involving PlaceHolderVar nodes often fell back to
default selectivity estimates, potentially leading to poor plan
choices.
This patch updates examine_variable() to strip PlaceHolderVars before
analysis. This is safe during estimation because PlaceHolderVars are
transparent for the purpose of statistics lookup: they do not alter
the value distribution of the underlying expression.
To minimize performance overhead on this hot path, a lightweight
walker first checks for the presence of PlaceHolderVars. The more
expensive mutator is invoked only when necessary.
There is one ensuing plan change in the regression tests, which is
expected and demonstrates the fix: the rowcount estimate becomes much
more accurate with this patch.
Back-patch to v18. Although this issue exists before that, changes in
this version made it common enough to notice. Given the lack of field
reports for older versions, I am not back-patching further.
Reported-by: Haowu Ge <gehaowu@bitmoe.com>
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/62af586c-c270-44f3-9c5e-02c81d537e3d.gehaowu@bitmoe.com
Backpatch-through: 18
When pulling up a subquery, we may need to wrap its targetlist items
in PlaceHolderVars to enforce separate identity or as a result of
outer joins. However, this causes any upper-level WHERE clauses
referencing these outputs to contain PlaceHolderVars, which prevents
indxpath.c from recognizing that they could be matched to index
columns or index expressions, potentially affecting the planner's
ability to use indexes.
To fix, explicitly strip PlaceHolderVars from index operands. A
PlaceHolderVar appearing in a relation-scan-level expression is
effectively a no-op. Nevertheless, to play it safe, we strip only
PlaceHolderVars that are not marked nullable.
The stripping is performed recursively to handle cases where
PlaceHolderVars are nested or interleaved with other node types. To
minimize performance impact, we first use a lightweight walker to
check for the presence of strippable PlaceHolderVars. The expensive
mutator is invoked only if a candidate is found, avoiding unnecessary
memory allocation and tree copying in the common case where no
PlaceHolderVars are present.
Back-patch to v18. Although this issue exists before that, changes in
this version made it common enough to notice. Given the lack of field
reports for older versions, I am not back-patching further.
Reported-by: Haowu Ge <gehaowu@bitmoe.com>
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/62af586c-c270-44f3-9c5e-02c81d537e3d.gehaowu@bitmoe.com
Backpatch-through: 18
This change makes more readable code diffs when adding new items or
removing old items, while ensuring that lines do not get excessively
long. Some SUBDIRS, PROGRAMS and REGRESS lists are split.
Note that there are a few more REGRESS lists that could be split,
particularly in contrib/.
Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Co-Authored-By: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Man Zeng <zengman@halodbtech.com>
Discussion: https://postgr.es/m/DF6HDGB559U5.3MPRFCWPONEAE@jeltef.nl
The correct spelling is Beijing, fix in regression test
and docs.
Author: JiaoShuntian <jiaoshuntian@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/ebfa3ec2-dc3c-4adb-be2a-4a882c2e85a7@gmail.com
Presumably, the C type MsgType was meant to hold the protocol message
type in the pre-version-3 era, but this was never fully developed even
then, and the name is pretty confusing nowadays. It has only one
vestigial use for cancel requests that we can get rid of. Since a
cancel request is indicated by a special protocol version number, we
can use the ProtocolVersion type, which MsgType was based on.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/505e76cb-0ca2-4e22-ba0f-772b5dc3f230%40eisentraut.org
The variable_is_guc_list_quote function need to know about all
GUC_QUOTE variables, this adds oauth_validator_libraries which
was missing. Backpatch to v18 where OAuth was introduced.
Author: ChangAo Chen <cca5507@qq.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/tencent_03D4D2A5C0C8DCE0CD1DB4D945858E15420A@qq.com
Backpatch-through: 18
pg_stat_get_backend_activity() calls pgstat_clip_activity() to ensure
that the reported query string is correctly truncated when it finishes
with an incomplete multi-byte sequence. However, the result returned by
the function was not what pgstat_clip_activity() generated, but the
non-truncated, original, contents from PgBackendStatus.st_activity_raw.
Oversight in 54b6cd589a, so backpatch all the way down.
Author: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2mDzwc48q2EK9tSXS6iJMJ35wvxNQnHX+rXjy5VgLvJQw@mail.gmail.com
Backpatch-through: 14
This change has the advantage of removing some weird type casts, caused
by offset calculations based on pgoff_t but saved as int (on older
branches we use off_t, which could be 4 or 8 bytes depending on the
environment). These are safe currently because capped by
MAX_PHYSICAL_FILESIZE, but we would run into problems when to make
MAX_PHYSICAL_FILESIZE larger or allow callers of these routines to use a
larger physical max size on demand.
While on it, this improves BufFileDumpBuffer() so as we do not use an
offset for "availbytes". It is not a file offset per-set, but a number
of available bytes.
This change should lead to no functional changes.
Author: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aUStrqoOCDRFAq1M@paquier.xyz
Many of the operations done for attribute stats in attribute_stats.c
share the same logic as extended stats, as done by a patch under
discussion to add support for extended stats import and export. All the
pieces necessary for extended statistics are moved to stats_utils.c,
which is the file where common facilities are shared for stats files.
The following renames are done:
* get_attr_stat_type() -> statatt_get_type()
* init_empty_stats_tuple() -> statatt_init_empty_tuple()
* set_stats_slot() -> statatt_set_slot()
* get_elem_stat_type() -> statatt_get_elem_type()
While on it, this commit adds more documentation for all these
functions, describing more their internals and the dependencies that
have been implied for attribute statistics. The same concepts apply to
extended statistics, at some degree.
Author: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Yu Wang <wangyu_runtime@163.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CADkLM=dpz3KFnqP-dgJ-zvRvtjsa8UZv8wDAQdqho=qN3kX0Zg@mail.gmail.com
If there are any SRFs in a PathTarget, we must separate it into
SRF-computing and SRF-free targets. This is because the executor can
only handle SRFs that appear at the top level of the targetlist of a
ProjectSet plan node.
If we find a subexpression that matches an expression already computed
in the previous plan level, we should treat it like a Var and should
not split it again. setrefs.c will later replace the expression with
a Var referencing the subplan output.
However, when processing the grouping target for grouping sets, the
planner can fail to recognize that an expression is already computed
in the scan/join phase. The root cause is a mismatch in the
nullingrels bits. Expressions in the grouping target carry the
grouping nulling bit in their nullingrels to indicate that they can be
nulled by the grouping step. However, the corresponding expressions
in the scan/join target do not have these bits.
As a result, the exact match check in list_member() fails, leading the
planner to incorrectly believe that the expression needs to be
re-evaluated from its arguments, which are often not available in the
subplan. This can lead to planner errors such as "variable not found
in subplan target list".
To fix, ignore the grouping nulling bit when checking whether an
expression from the grouping target is available in the pre-grouping
input target. This aligns with the matching logic in setrefs.c.
Backpatch to v18, where this issue was introduced.
Bug: #19353
Reported-by: Marian MULLER REBEYROL <marian.muller@serli.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/19353-aaa179bba986a19b@postgresql.org
Backpatch-through: 18
Commit 8a3e4011 introduced tab completion for the ONLY option of
VACUUM and ANALYZE, along with some code simplification using
MatchAnyN. However, it caused a regression in tab completion for
VACUUM option values. For example, neither ON nor OFF was suggested
after "VACUUM (VERBOSE". In addition, the ONLY keyword was not
suggested immediately after a completed option list.
Backpatch to v18.
Author: Yugo Nagata <nagata@sraoss.co.jp>
Discussion: https://postgr.es/m/20251223021509.19bba68ecbbc70c9f983c2b4@sraoss.co.jp
Backpatch-through: 18
Commit 67c209 removed the WARNING for insufficient wal_level from the
expected output, but the WARNING may still appear on buildfarm members
that run with wal_level=minimal.
To avoid unstable test output depending on wal_level, this commit the
test to use ALTER PUBLICATION for verifying the same behavior,
ensuring the output remains consistent regardless of the wal_level
setting.
Per buildfarm member thorntail.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Discussion: https://postgr.es/m/TY4PR01MB16907680E27BAB146C8EB1A4294B2A@TY4PR01MB16907.jpnprd01.prod.outlook.com
The pg_overexplain documentation previously used the <literal> tag for
some file names, struct names, and commands. Update the markup to
use the more appropriate tags: <filename>, <structname>, and <command>.
Backpatch to v18, where pg_overexplain was introduced.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Shixin Wang <wang-shi-xin@outlook.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwEyYUzz0LjBV_fMcdwU3wgmu0NCoT+JJiozPa8DG6eeog@mail.gmail.com
Backpatch-through: 18
CREATE SUBSCRIPTION with copy_data=true and origin='none' previously
failed when the publisher was running a version earlier than PostgreSQL 19,
even though this combination should be supported.
The failure occurred because the command issued a query calling
pg_get_publication_sequences function on the publisher. That function
does not exist before PG19 and the query is only needed for logical
replication sequence synchronization, which is supported starting in PG19.
This commit fixes this issue by skipping that query when the
publisher runs a version earlier than PG19.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwEx4twHtJdiPWTyAXJhcBPLaH467SH2ajGSe-41m65giA@mail.gmail.com
The retain_dead_tuples subscription option is supported only when
the publisher runs PostgreSQL 19 or later. However, it could previously
be enabled even when the publisher was running an earlier version.
This was caused by check_pub_dead_tuple_retention() comparing
the publisher server version against 19000 instead of 190000.
Fix this typo so that the version check correctly enforces the PG19+
requirement.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwEx4twHtJdiPWTyAXJhcBPLaH467SH2ajGSe-41m65giA@mail.gmail.com
Update the logical replication documentation to explicitly outline the
privilege requirements for each publication syntax. This will ensure users
understand the necessary permissions when creating or managing
publications.
Author: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CANhcyEXODen4U0XLk0aAwFTwGxjAfE9eRaynREenLp-JBSaFHw@mail.gmail.com
Currently, the function expr_is_nonnullable() checks only Const and
Var expressions to determine if an expression is non-nullable. This
patch extends the detection logic to handle more expression types.
This can enable several downstream optimizations, such as reducing
NullTest quals to constant truth values (e.g., "COALESCE(var, 1) IS
NULL" becomes FALSE) and converting "COUNT(expr)" to the more
efficient "COUNT(*)" when the expression is proven non-nullable.
This breaks a test case in test_predtest.sql, since we now simplify
"ARRAY[] IS NULL" to constant FALSE, preventing it from weakly
refuting a strict ScalarArrayOpExpr ("x = any(ARRAY[])"). To ensure
the refutation logic is still exercised as intended, wrap the array
argument in opaque_array().
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49UhPBjm+NRpxerjaeuFKyUZJ_AjM3NBcSYK2JgZ6VTEQ@mail.gmail.com
We break ROW(...) IS [NOT] NULL into separate tests on its component
fields. During this breakdown, we can improve efficiency by utilizing
expr_is_nonnullable() to detect fields that are provably non-nullable.
If a component field is proven non-nullable, it affects the outcome
based on the test type. For an IS NULL test, a single non-nullable
field refutes the whole NullTest, reducing it to constant FALSE. For
an IS NOT NULL test, the check for that specific field is guaranteed
to succeed, so we can discard it from the list of component tests.
This extends the existing optimization logic, which previously only
handled Const fields, to support any expression that can be proven
non-nullable.
In passing, update the existing constant folding of NullTests to use
expr_is_nonnullable() instead of var_is_nonnullable(), enabling it to
benefit from future improvements to that function.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49UhPBjm+NRpxerjaeuFKyUZJ_AjM3NBcSYK2JgZ6VTEQ@mail.gmail.com
The COALESCE function returns the first of its arguments that is not
null. When an argument is proven non-null, if it is the first
non-null-constant argument, the entire COALESCE expression can be
replaced by that argument. If it is a subsequent argument, all
following arguments can be dropped, since they will never be reached.
Currently, we perform this simplification only for Const arguments.
This patch extends the simplification to support any expression that
can be proven non-nullable.
This can help avoid the overhead of evaluating unreachable arguments.
It can also lead to better plans when the first argument is proven
non-nullable and replaces the expression, as the planner no longer has
to treat the expression as non-strict, and can also leverage index
scans on the resulting expression.
There is an ensuing plan change in generated_virtual.out, and we have
to modify the test to ensure that it continues to test what it is
intended to.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49UhPBjm+NRpxerjaeuFKyUZJ_AjM3NBcSYK2JgZ6VTEQ@mail.gmail.com
The logical replication parallel apply worker could incorrectly advance
the origin progress during an error or failed apply. This behavior risks
transaction loss because such transactions will not be resent by the
server.
Commit 3f28b2fcac addressed a similar issue for both the apply worker and
the table sync worker by registering a before_shmem_exit callback to reset
origin information. This prevents the worker from advancing the origin
during transaction abortion on shutdown. This patch applies the same fix
to the parallel apply worker, ensuring consistent behavior across all
worker types.
As with 3f28b2fcac, we are backpatching through version 16, since parallel
apply mode was introduced there and the issue only occurs when changes are
applied before the transaction end record (COMMIT or ABORT) is received.
Author: Hou Zhijie <houzj.fnst@fujitsu.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 16
Discussion: https://postgr.es/m/TY4PR01MB169078771FB31B395AB496A6B94B4A@TY4PR01MB16907.jpnprd01.prod.outlook.com
Discussion: https://postgr.es/m/TYAPR01MB5692FAC23BE40C69DA8ED4AFF5B92@TYAPR01MB5692.jpnprd01.prod.outlook.com
This one was missed in 8f1791c61, because the machines that
detected those issues don't compile this function.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1324889.1764886170@sss.pgh.pa.us
This commit updates pg_visibility_map_summary() to use the
visibilitymap_count() API, replacing its own counting mechanism. This
simplifies the function and improves performance by leveraging the
vectorized implementation introduced in commit 41c51f0c68.
Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: wenhui qiu <qiuwenhuifx@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAEze2WgPu-EYYuYQimy=AHQHGa7w8EvLVve5DM5eGMR6zh-7sw@mail.gmail.com
Previously logical decoding required wal_level to be set to 'logical'
at server start. This meant that users had to incur the overhead of
logical-level WAL logging even when no logical replication slots were
in use.
This commit adds functionality to automatically control logical
decoding availability based on logical replication slot presence. The
newly introduced module logicalctl.c allows logical decoding to be
dynamically activated when needed when wal_level is set to
'replica'.
When the first logical replication slot is created, the system
automatically increases the effective WAL level to maintain
logical-level WAL records. Conversely, after the last logical slot is
dropped or invalidated, it decreases back to 'replica' WAL level.
While activation occurs synchronously right after creating the first
logical slot, deactivation happens asynchronously through the
checkpointer process. This design avoids a race condition at the end
of recovery; a concurrent deactivation could happen while the startup
process enables logical decoding at the end of recovery, but WAL
writes are still not permitted until recovery fully completes. The
checkpointer will handle it after recovery is done. Asynchronous
deactivation also avoids excessive toggling of the logical decoding
status in workloads that repeatedly create and drop a single logical
slot. On the other hand, this lazy approach can delay changes to
effective_wal_level and the disabling logical decoding, especially
when the checkpointer is busy with other tasks. We chose this lazy
approach in all deactivation paths to keep the implementation simple,
even though laziness is strictly required only for end-of-recovery
cases. Future work might address this limitation either by using a
dedicated worker instead of the checkpointer, or by implementing
synchronous waiting during slot drops if workloads are significantly
affected by the lazy deactivation of logical decoding.
The effective WAL level, determined internally by XLogLogicalInfo, is
allowed to change within a transaction until an XID is assigned. Once
an XID is assigned, the value becomes fixed for the remainder of the
transaction. This behavior ensures that the logging mode remains
consistent within a writing transaction, similar to the behavior of
GUC parameters.
A new read-only GUC parameter effective_wal_level is introduced to
monitor the actual WAL level in effect. This parameter reflects the
current operational WAL level, which may differ from the configured
wal_level setting.
Bump PG_CONTROL_VERSION as it adds a new field to CheckPoint struct.
Reviewed-by: Shveta Malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/CAD21AoCVLeLYq09pQPaWs+Jwdni5FuJ8v2jgq-u9_uFbcp6UbA@mail.gmail.com
After waiting for a concurrent updater to finish, heap_lock_tuple()
followed the update chain to lock all tuple versions. However, when
stepping from the initial tuple to the next one, it failed to check
that the next tuple's XMIN matches the initial tuple's XMAX. That's an
important check whenever following an update chain, and the recursive
part that follows the chain did it, but the initial step missed it.
Without the check, if the updating transaction aborts, the updated
tuple is vacuumed away and replaced by an unrelated tuple, the
unrelated tuple might get incorrectly locked.
Author: Jasper Smit <jasper.smit@servicenow.com>
Discussion: https://www.postgresql.org/message-id/CAOG+RQ74x0q=kgBBQ=mezuvOeZBfSxM1qu_o0V28bwDz3dHxLw@mail.gmail.com
Backpatch-through: 14
Since ce0fdbfe97, a replication slot and an origin are created by each
tablesync worker, whose information is stored in both a catalog and
shared memory (once the origin is set up in the latter case). The
transaction where the origin is created is the same as the one that runs
the initial COPY, with the catalog state of the origin becoming visible
for other sessions only once the COPY transaction has committed. The
catalog state is coupled with a state in shared memory, initialized at
the same time as the origin created in the catalogs. Note that the
transaction doing the initial data sync can take a long time, time that
depends on the amount of data to transfer from a publication node to its
subscriber node.
Now, when a DROP SUBSCRIPTION is executed, all its workers are stopped
with the origins removed. The removal of each origin relies on a
catalog lookup. A worker still running the initial COPY would fail its
transaction, with the catalog state of the origin rolled back while the
shared memory state remains around. The session running the DROP
SUBSCRIPTION should be in charge of cleaning up the catalog and the
shared memory state, but as there is no data in the catalogs the shared
memory state is not removed. This issue would leave orphaned origin
data in shared memory, leading to a confusing state as it would still
show up in pg_replication_origin_status. Note that this shared memory
data is sticky, being flushed on disk in replorigin_checkpoint at
checkpoint. This prevents other origins from reusing a slot position
in the shared memory data.
To address this problem, the commit moves the creation of the origin at
the end of the transaction that precedes the one executing the initial
COPY, making the origin immediately visible in the catalogs for other
sessions, giving DROP SUBSCRIPTION a way to know about it. A different
solution would have been to clean up the shared memory state using an
abort callback within the tablesync worker. The solution of this commit
is more consistent with the apply worker that creates an origin in a
short transaction.
A test is added in the subscription test 004_sync.pl, which was able to
display the problem. The test fails when this commit is reverted.
Reported-by: Tenglong Gu <brucegu@amazon.com>
Reported-by: Daisuke Higuchi <higudai@amazon.com>
Analyzed-by: Michael Paquier <michael@paquier.xyz>
Author: Hou Zhijie <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/aUTekQTg4OYnw-Co@paquier.xyz
Backpatch-through: 14
off_t was previously used for offsets, which is 4 bytes on Windows,
hence limiting the backend code to a hard limit for files longer than
2GB. This leads to some simplification in these files, removing some
casts based on long, also 4 bytes on Windows.
This commit removes one comment introduced in db3c4c3a2d, not relevant
anymore as pgoff_t is a safe 8-byte alternative on Windows.
This change is surprisingly not invasive, as the callers of
BufFileTell(), BufFileSeek() and BufFileTruncateFileSet() (worker.c,
tuplestore.c, etc.) track offsets in local structures that just to
switch from off_t to pgoff_t for the most part.
The file is still relying on a maximum file size of
MAX_PHYSICAL_FILESIZE (1GB). This change allows the code to make this
maximum potentially larger in the future, or larger on a per-demand
basis.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aUStrqoOCDRFAq1M@paquier.xyz
Previously, only the first option in a parenthesized option list was
suggested by tab completion. This commit enhances tab completion for
both COPY TO and COPY FROM commands to suggest options after each
comma.
Also add completion for HEADER and FREEZE option value candidates.
Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/20250605100835.b396f9d656df1018f65a4556@sraoss.co.jp
Correct the referenced location of the RangeTblEntry definition
in the pg_overexplain documentation.
Backpatched to v18, where pg_overexplain was introduced.
Author: Julien Tachoires <julien@tachoires.me>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20251218092319.tht64ffmcvzqdz7u@poseidon.home.virt
Backpatch-through: 18
Tom Lane