_reconnectToDB() failed to consider the possibility that it could
be called without any restrict_key set. This is reachable while
generating the "restore.sql" file in tar dump mode, which nobody
noticed because that file is mostly unused (and nothing really
bad happens anyway unless you specified --inserts mode). But
I wonder if there are other code paths that reach the issue.
Bug: #19718
Reported-by: Pavel Kopylov <pkopylov@cloudlinux.com>
Author: Pavel Kopylov <pkopylov@cloudlinux.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19718-7e945d0ff9b5a589@postgresql.org
Backpatch-through: 14
pg_restore_attribute_stats() rejected range_length_histogram,
range_empty_frac and range_bounds_histogram for a column whose type is a
domain over a range or a multirange type. The same issue existed for
most_common_elems and elem_count_histogram for a domain over tsvector.
pg_restore_extended_stats() had the same set of problems for expressions
whose type is a domain over a range, a multirange type, or tsvector.
ANALYZE is able to generate such stats, incorporating the knowledge to
handle domains in the in-core typanalyze callbacks.
This problem is resolved by being more aggressive with the fetch of the
base type of a domain in the early phases of restore for attribute and
extended stats (special tip to Jian He for pointing out the unnecessary
typcache lookups), reflecting on the surrounding helper routines shared
by both code paths. The fix for v18 is local to attribute_stats.c, as
only attribute stats need to be touched.
Tests are included in a fashion consistent with the surroundings. The
consequence of this issue was the rejection of stats that ANALYZE was
able to build, which was not critical but annoying as it would lead to a
gap in the stats restored.
Reported-by: Qifan Liu <imchifan@163.com>
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://postgr.es/m/19715-b8be35083016f289@postgresql.org
Backpatch-through: 18
gcc 12.5.0 complains about this instance in LookupFuncWithArgs().
This is the same type of problem fixed in commit f04781df5, and
it's just as obscure why this compiler version picks on this case
when others don't. Still, silence it in the same way as f04781df5.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1812498.1790279465@sss.pgh.pa.us
Backpatch-through: 14
Remove assertion that was too strict, and tripped if you queried the
pg_shmem_allocations_numa or the pg_buffercache_os_pages view in
single-user mode.
The point of the assertion was that the function should only be called
after "the server has started", but it would be OK to call it from the
postmaster, too, as long as it's after startup, specifically after
huge_pages_status has been set. We already have a direct assertion
for that.
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAJTYsWV-=w5_oFgCnfAixWGc=gMa2pkDinLyGLsb4sKcDaf2FA@mail.gmail.com
Backpatch-through: 18
SnapBuildInitialSnapshot() converts the snapshot builder's list of
committed transactions into a regular MVCC snapshot, which is then used
with HeapTupleSatisfiesMVCC(). However, a snapshot produced that way
and used as an MVCC snapshot can potentially cause data corruption, if
it captures a transaction after it writes its commit WAL record but
before it has updated its CLOG entry: it will be incorrectly used to set
hint bits as if that transaction had aborted.
Fix by having SnapBuildInitialSnapshot() wait until such transactions
have removed themselves from procarray, which guarantees correct
visibility.
Other uses of SnapBuildBuildSnapshot only use the snapshot as
historical, so they don't need the waits, but add commentary in that
function to alert possible future callers.
While at this, backpatch commit 504fe10d1d, "Fix misplaced comment in
snapbuild.c." The comment it moved was nearby the place we modify.
This bug was diagnosed by stress-testing of REPACK (CONCURRENTLY) in
branch 19, so add a test case that tickles it using that feature in that
branch and master. However, the bug exists in all branches, and in
branch 18 we can add a test with regular logical decoding using
injection points that tickles it. Unfortunately that test cannot be
backpatched to earlier branches for lack of facilities.
Reported-by: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
Author: Antonin Houska <ah@cybertec.at>
Author: Rui Zhao <zhaorui126@gmail.com>
Backpatch-through: 14
Discussion: https://postgr.es/m/85833.1768840165@localhost
Discussion: https://postgr.es/m/CADzfLwU78as45To9a%3D-Qkr5jEg3tMxc5rUtdKy2MTv4r_SDGng%40mail.gmail.com
heapgettup_advance_block() (or heapgettup() and heapgettup_pagemode() in
versions before v16) would incorrectly decrement rs_numblocks when
advancing to the next block. Ordinarily this was fine, but if the TID
Range scan plan was used by a scrollable cursor and the cursor was fetched
backwards enough to result in another block being required, then
rs_numblocks may have reached 0 prematurely resulting in the scan ending
prematurely.
Reported-by: Jeff Davis <pgsql@j-davis.com>
Author: Ewan Young <kdbase.hack@gmail.com>
Author: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/6b50233fcc0f7d6f4845f083777fa9702d9612e4.camel@j-davis.com
Backpatch-through: 14
When executing a WHEN NOT MATCHED BY SOURCE action in MERGE, if the
tuple from the target table was concurrently deleted, the retry code
would incorrectly execute a WHEN NOT MATCHED BY TARGET action for the
row instead, giving incorrect results.
Fix in ExecMergeMatched() -- when handling a TM_Deleted failure
status, it should only set *matched to false (telling the caller to
execute any WHEN NOT MATCHED BY TARGET actions) if the failed action
was a WHEN MATCHED action. For a failed WHEN NOT MATCHED BY SOURCE
action, the source tuple did not exist, and the target tuple has just
been deleted, so it should do nothing.
Back-patch to v17, where support for WHEN NOT MATCHED BY SOURCE
actions was introduced.
Reported-by: Jeff Davis <pgsql@j-davis.com>
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/ccdab5ba02c65af195b5a6d2d744a01d9de47cd3.camel@j-davis.com
Backpatch-through: 17
6dbb490261 combined pruning and freezing in a single WAL record but
unconditionally requested a cleanup lock during replay. Prior to version
17, freeze-only records were replayed under an ordinary exclusive lock.
1252a4ee28 subsequently folded visibility map updates into the same
records, extending the unnecessary cleanup-lock requirement to VM-only
updates starting in version 19.
Request a cleanup lock in redo only when the record actually prunes.
Freezing and visibility updates do not move or remove tuple storage, so
they need not wait for other buffer pins to be released. This avoids
unnecessary replay delays and cancellation of standby queries holding
buffer pins.
The fix is the same for all versions, though it addresses two oversights
in master/19 and one in 18/17.
Reported-by: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Reported-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/85b6968b-49f2-4243-86a6-9b4116e6439b@iki.fi
Discussion: https://postgr.es/m/CAHg+QDf3NcB3vOAqQ5EFcV5DYYUZ9snCSJAU-x1JDbtcjK3eBQ@mail.gmail.com
Discussion: https://postgr.es/m/F9BF304E-1298-481C-829A-B4E10AED025A@yandex-team.ru
Backpatch-through: 17
Similar to commit "Remove unused global variables", silence
-Wunused-but-set-global warnings from clang 23 (included in -Wall).
These are variables that are used in assert-enabled builds only, so
annotate them with PG_USED_FOR_ASSERTS_ONLY.
When a join has an alias, the parser marks every Var referenced
through that alias with the join's RT index as its syntactic referent
(varnosyn), even though varno points at the underlying base relation.
Since commit 2ebf25e7d, join removal strips the removed relids from
the query tree using ChangeVarNodes() with INVALID_VAR, which asserts
that the relid doesn't appear in any field identifying a single
relation. A varnosyn that names the removed join violates that, so a
query like
SELECT j.x FROM (t1 s(x) LEFT JOIN t2 ON s.x = t2.a) j;
with t2.a unique fails an assertion. In non-assert builds, varnosyn
is silently set to INVALID_VAR.
Such syntactic references are still valid after the removal: the join
is only taken out of the jointree, and its RTE remains in the
rangetable through to the finished plan. So, when deleting a relid,
leave varnosyn unchanged, as join removal did before 2ebf25e7d.
Back-patch to v16, as with commit 2ebf25e7d.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAMbWs484SQSdzWTgZYKvwtuC6J4m7acw0LfBjp3aWPvav7gC_w@mail.gmail.com
Backpatch-through: 16
Commit e28cf96e9 preprocessed the copies of a query level's
PlaceHolderVars that were pushed down into its subqueries in a single
walk at the start of subquery_planner. That was wrong in two ways.
First, such copies can also be inserted later, when a join alias Var
of the outer level is expanded within a LATERAL subquery or a
SubLink's subselect and the alias expression contains a PHV. Those
copies were never preprocessed, so a SubLink within them survived into
the subquery's lateral references or into a SubPlan's argument list,
tripping an assertion in identify_current_nestloop_params or failing
in cost_qual_eval.
Second, when a pushed-down copy directly contains another PHV of the
same level, the walk preprocessed the inner one first and then the
outer one, so the outer one's preprocessing ran into the SubPlans just
created in the inner one and tripped an assertion in
flatten_join_alias_vars.
To fix, preprocess the copies right after join alias expansion
instead: within preprocess_expression, just before SubLinks are turned
into SubPlans, and for LATERAL subquery RTEs, right after their
aliases are flattened. Preprocessing a copy handles everything within
it, including any further copies nested inside its SubLinks, so the
walker no longer looks inside a copy.
Back-patch to v16, as with commit e28cf96e9.
Reported-by: Fujii Masao <masao.fujii@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwH-acRnAk1=Ki4EiAJEt67+Rz=_jyg7pbP_c6BK4oHZ4Q@mail.gmail.com
Backpatch-through: 16
The PASSING arguments of JSON_EXISTS(), JSON_QUERY(), JSON_VALUE() and
JSON_TABLE() are evaluated by plain expression steps and given to the
jsonpath executor as-is.
When dealing with a varlena, JsonItemFromDatum() was building a
jbvString directly the contents of a varlena. For a varatt_external
(varatt_external[oid/oid8] on HEAD), this ignored that the contents of
the varlena need to be detoasted, leading to incorrect contents
returned.
Let's detoast the value, like the jsonb and json cases. b0feda79fd
has fixed the same issue for subscript values in jsonb.
Note that the results of DatumGetTextPP() are allocated in the memory
context used for the evaluation of the expression, which is reset once
per row.
Oversight in 6185c9737c.
Author: Chaitanya Choudhary <chaitanyyachoudhary@gmail.com>
Author: Shihao Zhong <zhong950419@gmail.com>
Discussion: https://postgr.es/m/19693-2ecd2b52c838b3e5@postgresql.org
Backpatch-through: 17
pgoutput records the toplevel XID in the relation's streamed_txns
list, allocated in CacheMemoryContext, when it sends a relation's
schema during a streamed transaction. We clean up that list at stream
commit and stream abort, but missed stream prepare, so the XIDs stay
around until a relcache invalidation for the relation or until the
walsender exits.
Fix by cleaning up the cache after writing the stream prepare message,
marking the schema as sent as we do at stream commit. The subscriber
applies the spooled relation messages at PREPARE time and its relation
map isn't rolled back by ROLLBACK PREPARED, so we don't need to send
the schema again even if the prepared transaction eventually aborts.
Oversight in commit 63cf61cdeb.
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAJTYsWWt5aaKHCnV=jNOwABzspd-WbnhWLndDqtESDQRQ-BkKQ@mail.gmail.com
Backpatch-through: 15
We unintentionally copied the original query's limitOption field while
building the modified subquery. If it was LIMIT_OPTION_WITH_TIES,
that behavior would propagate through to execution, potentially
causing a "more than one row returned by a subquery used as an
expression" error. Fix by resetting to the default LIMIT_OPTION_COUNT.
This bug dates back to the introduction of WITH TIES.
Bug: #19694
Reported-by: Chaitanya Choudhary <chaitanyyachoudhary@gmail.com>
Author: Chaitanya Choudhary <chaitanyyachoudhary@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19694-4e61bd0475398eef@postgresql.org
Backpatch-through: 14
Some code added in 489247b0e tried to prune the DEFAULT partition when
the next partition had a MINVALUE clause and likewise when the final
partition to scan had a MAXVALUE clause for the final partition key in
the pruning step. This code was incorrect as it could prune the default
partition incorrectly in cases such as:
p: PARTITION BY RANGE (a, b)
p1: FOR VALUES FROM (13, 0) TO (19, MAXVALUE)
pd: DEFAULT
SELECT * FROM t WHERE a = 32 AND b >= -7;
Here the pruning step for a = 32 and b >= -7 would see that only the
default partition needs to be scan, but it would then see that the
partition prior to the default had a MAXVALUE bound then prune away the
default thinking that it needn't be scanned. This could result in
incorrect results.
Fix this by moving the code that looks for the MAXVALUE bound into the
code handling BTEqualStrategyNumber so that when we're pruning with a
prefix of the partition keys, we check if the bound for the offset we've
calculated lands on a partition where the next partition key is bounded
with MAXVALUE. If so we don't include the default partition.
This leaves only the case of the first partition key. We handle that by
modifying the existing code that was checking the last key covered by
the given values.
Author: Ewan Young <kdbase.hack@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAON2xHO=sqdqp=z8zWkybnWp0AuvefnAi2ez2vOYWrhXB6hHWQ@mail.gmail.com
Backpatch-through: 14
Building the partition pruning steps for excessively complex queries
can take some time. Add CHECK_FOR_INTERRUPTS() to
get_steps_using_prefix_recurse() to allow more timely processing of
interruptions.
Bug: #19692
Reported-by: Qifan Liu <imchifan@163.com>
Discussion: https://postgr.es/m/19692-dacfc57cda5035fc@postgresql.org
Backpatch-through: 14
The check_oauth_validator check for an empty validator list didn't test
for a string with only whitespace, which would cause the postmaster to
crash. Instead of testing for the empty string cases, pass the config
value to SplitDirectoriesString unconditionally. If an empty list is
returned then the input string was empty. Since pstrdup cannot handle
NULL, assert that the string ie set. While users cannot set the string
to NULL, it is initialized to NULL so guard against programmer error.
Check the parsed list instead. Assert that the GUC string is non-NULL
before pstrdup(); users cannot set it to NULL, but the C variable is
initialized that way.
This also adds a TAP test that reloads a whitespace-only setting after
pg_hba_file_rules and waits until the existing backend sees the restored
GUC.
Author: Grigorev Jurij <ju.grigorev@ftdata.ru>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/04fa84f6ebbe400f940e179ebe1070e9@localhost.localdomain
Backpatch-through: 18
pgstat_get_entry_ref_cached() inserts a local entry_ref with
shmem-related fields set to NULL, expecting pgstat_get_entry_ref() (its
sole caller) to fill them up before returning. If an ERROR happens
while pgstat_get_entry_ref() runs, it could be possible to finish with a
local pgstats entry partially filled.
This could lead to a crash of pgstat_gc_entry_refs(), which tolerates a
NULL shared_stats in an assertion but unconditionally dereferenced its
"dropped" and "generation" fields.
This extends 4069df21be, being a cheap insurance against NULL pointer
dereference, if some code paths of pgstat_get_entry_ref() are not able
to perform any cleanup actions (for example after a dsm_create()
throwing an ERROR).
Reviewed-by: Grigorev Jurij <ju.grigorev@ftdata.ru>
Discussion: https://postgr.es/m/aqtiKTvl519bu8-V@paquier.xyz
Backpatch-through: 15
Previously, aborting an internal subtransaction during COMMIT or
PREPARE TRANSACTION could cause the following assertion failure.
This could happen, for example, when a deferred constraint trigger fired
at COMMIT and its PL/pgSQL exception block caught an error raised
while executing the trigger function.
TRAP: failed Assert("s->blockState == TBLOCK_SUBINPROGRESS || s->blockState
== TBLOCK_INPROGRESS || s->blockState == TBLOCK_IMPLICIT_INPROGRESS ||
s->blockState == TBLOCK_PARALLEL_INPROGRESS || s->blockState ==
TBLOCK_STARTED"), File: "xact.c", Line: 4851, PID: 73455
An internal subtransaction should be able to be aborted while the parent
transaction is in the COMMIT or PREPARE TRANSACTION phase. However,
RollbackAndReleaseCurrentSubTransaction()'s assertion check previously
did not allow TBLOCK_END and TBLOCK_PREPARE as parent transaction
states, causing the assertion failure.
This commit fixes the assertion check by allowing those two parent
transaction states.
Backpatch to all supported versions.
Reported-by: Fabrízio de Royes Mello <fabrizio@planetscale.com>
Author: Patrick Reynolds <piki@planetscale.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Fabrízio de Royes Mello <fabrizio@planetscale.com>
Discussion: https://postgr.es/m/CABo-N97AeMbWuYTWg-3%3D2DkTR3EkvS%2BFt%3DyEaWB181STsR1mBg%40mail.gmail.com
Backpatch-through: 14
A semijoin whose RHS is unique-ified groups the RHS on the expressions in
SpecialJoinInfo.semi_rhs_exprs. Those were recorded with whatever collation
the RHS expression itself exposes, which need not be the collation the join
compares with. Neither SortGroupClause nor the pathkey machinery carries a
collation of its own, so both Unique-over-Sort and HashAggregate then grouped
by the wrong equality: values the join considers equal survived, and the
following inner join emitted the outer row once per survivor.
With a non-deterministic collation on one side, "SELECT count(*) FROM t WHERE
c IN (SELECT c0 FROM t2)" therefore counted more rows than the same predicate
reports for the rows of t.
Label each RHS expression with the operator's input collation, the same
treatment process_equivalence() gives to equivalence class members. Every
consumer of semi_rhs_exprs reads the collation off the expression, so this
fixes the sort-based and hash-based paths together; in the branches where
create_unique_path() also passes these expressions to
relation_has_unique_index_for(), it likewise stops a unique index built with a
different collation from being taken as proof that unique-ification can be
skipped. The same goes for a subquery's DISTINCT computed under a different
collation, since translate_sub_tlist() punts on the relabeled expressions.
Reported-by: Suyang Zhong <syzhong16@gmail.com>
Author: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Discussion: https://postgr.es/m/19633-647cd4c73a84b085%40postgresql.org
Backpatch-through: 14
INSERT ... ON CONFLICT decides what to do based on the conflicting row
found by the arbiter index probe, but SSI never saw that read: the
probe runs with a dirty snapshot, which predicate locking ignores, and
the later fetch of the row uses SnapshotAny. When the statement then
writes nothing, as with DO NOTHING, DO UPDATE with a WHERE clause
rejecting the row, or DO SELECT, nothing records the read at all. A
concurrent writer of that row went unnoticed and write skew could
commit at SERIALIZABLE, even though the same schedule with a plain
SELECT of the row fails with a serialization error.
To fix, read the conflicting tuple again with the query snapshot,
right where the probe finds it. The table AM takes the SIREAD lock
and checks for a concurrent writer of the tuple as part of that read,
both under the buffer lock, so a writer either sees the lock or is
seen. A predicate lock by itself acquired separately after the probe
could not offer that: a writer passing its conflict check in between
would be missed. Doing this in the probe covers every conflict
action, including rows that the WHERE clause of DO UPDATE or DO SELECT
then rejects.
The DO NOTHING and DO UPDATE cases have been broken since ON CONFLICT
was added in 9.5; DO SELECT is new in v19. Backpatch to all supported
branches.
Author: Zsolt Parragi <zsolt.parragi@percona.com>
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Reported-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reported-by: Zsolt Parragi <zsolt.parragi@percona.com>
Discussion: https://postgr.es/m/787936C5-4155-4CF9-939D-39DC0EC1C892@yandex-team.ru
Discussion: https://postgr.es/m/CAN4CZFM1GkHJkpMeo4G5rxtacVsfeKCJYiik9E9AKX1E9VYQ1w@mail.gmail.com
Backpatch-through: 14
During a parallel GIN build, each key is serialized into a GinTuple, a
transient representation used only while sorting. _gin_build_tuple()
lays out the whole tuple (the palloc size, the key memcpy, and the
offset of the posting list) from a local variable holding the real key
length, but then stored that length in GinTuple.keylen, which was
uint16. For a key longer than 65535 bytes, the stored length was thus
silently truncated.
On read-back, GinTupleGetFirst() and _gin_parse_tuple_items()
recompute the posting-list offset from the truncated keylen and land
inside the key data, so ginPostingListDecodeAllSegments() decodes
garbage: an assertion failure with assertions enabled, and a read past
the end of the allocation without, which could in turn lead to a crash
or garbage being written into the index. Only parallel builds are
affected, because only they materialize a GinTuple; a serial build of
the same data succeeds, as index_form_tuple() compresses large keys
before the GinMaxItemSize check.
To fix, widen GinTuple.keylen to Size, which is what VARSIZE_ANY()
returns and what GinBuffer.keylen already uses, and use Size for the
local in _gin_build_tuple() too, which was an int that truncated
VARSIZE_ANY() the same way.
Widening keylen moves GinTuple.data. The key value is accessed in
place in data, so data must be MAXALIGN'ed; before, that was only true
by accident of the field layout. This branch predates the use of C11
alignas, so force the alignment the way PGAlignedBlock did: put keylen
in a union with double and int64 members, which puts data at a
MAXALIGN'ed offset on all platforms, including 32-bit ones where Size
is 4 bytes and MAXIMUM_ALIGNOF is 8. A static assertion verifies the
resulting offset.
Bug: #19545
Author: Ewan Young <kdbase.hack@gmail.com>
Reported-by: Yuelin Wang <1217816127@qq.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://www.postgresql.org/message-id/flat/19545-0f25b7e47351e8fc%40postgresql.org
A JSON constructor with a RETURNING clause uses a CaseTestExpr as the
placeholder for its result in the coercion expression. When such a
constructor appears in a WHEN clause of a simple CASE whose test
expression is a constant, eval_const_expressions substituted that
constant for the placeholder, so the coercion produced the CASE's test
value instead of the constructor's result. For instance,
CASE 'x' WHEN JSON_OBJECT('a': 'b' RETURNING text) THEN 1 ELSE 0 END
evaluated to 1.
To fix, keep case_val out of scope while simplifying the coercion, as
is already done for the elemexpr of an ArrayCoerceExpr.
Back-patch to v16, where the SQL/JSON constructor functions were
introduced.
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAMbWs48A=VCFbteTkuCoknO1_0-Cu0aMBT0M07dm7vj1QyixDg@mail.gmail.com
Backpatch-through: 16
When a subquery references an output of another subquery that gets
pulled up, and that output must be wrapped in a PlaceHolderVar because
of an intermediate outer join, the PHV expression is pushed down into
the subquery. That copy is not preprocessed along with the outer
query's expressions, so the two copies can diverge. This used to be
harmless, but since commit 2ebf25e7d join removal edits the whole
query tree, walking into subqueries, and can trip an assert in
ChangeVarNodes if it removes a rel whose Var survives only in such a
copy.
To fix, preprocess these copies at their owning query level, early in
subquery_planner, before anything can consume them (in particular
before SubLinks are turned into SubPlans). This covers copies pushed
into both LATERAL subquery RTEs and SubLink subselects, and handles
nested copies innermost-first. extract_lateral_references no longer
preprocesses the copies it pulls out.
Correspondingly, the subquery's own processing must leave the contents
of an upper-level PHV alone, since the owning level has already
preprocessed them: eval_const_expressions returns such a PHV
unchanged, and flatten_join_alias_vars no longer recurses into it.
Back-patch to v16, as with commit 2ebf25e7d.
Reported-by: Tender Wang <tndrwang@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAHewXN=kWGAXV537mKtSyBYobGdHhYJVDJJMXXZEmmPWE_zaPw@mail.gmail.com
Backpatch-through: 16
The in-tree getopt_long() moves each non-option to the end of argv,
which might put it right where an option's argument lookup expects
to find the argument. For example, "vacuumdb postgres --jobs"
takes "postgres" as the number of jobs instead of complaining that
--jobs is missing its argument. To fix, stop the argument lookups
at the start of the moved non-options, which we already track to
know when to stop scanning.
Oversight in commit 411b720343.
Author: Sehrope Sarkuni <sehrope@jackdb.com>
Reviewed-by: solai v <solai.cdac@gmail.com>
Discussion: https://postgr.es/m/CAH7T-arxDuVCSkorO%3Dk7%2BM-_JV0JFzMpN_EtKMyD2K0RDqZ2OA%40mail.gmail.com
Backpatch-through: 17
Several global variables are only used in Windows build. This causes
-Wunused-but-set-global warnings that the new clang 23 enables via
-Wall.
This commit marks these with an unused attribute to silence the
warnings.
(In the master branch, this is addressed differently, but for
backpatching, this just silences the warnings without any behavior
change.)
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/eb013f9d-2247-444e-8815-9d17b4ce78e7%40eisentraut.org
The new clang 23 has a new warning about set-but-unused
static (internal-linkage) global variables: -Wunused-but-set-global,
which is activated in PostgreSQL builds via -Wall. This triggers a
few warnings in PostgreSQL code. This commit removes several such
variables that were either never used or whose last use was removed
some time ago.
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/eb013f9d-2247-444e-8815-9d17b4ce78e7%40eisentraut.org
The tab-completion query used for ALTER DATABASE ... RESET referenced
pg_db_role_setting and pg_database without schema qualification, so a
same-named relation earlier in search_path could be used instead of the
system catalogs. This could make psql offer misleading RESET candidates.
Commit dbf5a83d46 schema-qualified the unnest() call in this same query,
but the catalog references were still left unqualified. Fix that by
referring to pg_catalog.pg_db_role_setting and pg_catalog.pg_database
explicitly.
Backpatch to 18, where the tab-completion for ALTER DATABASE ... RESET
was introduced.
Bug: #19523
Reported-by: Zhou Digoal <digoal@126.com>
Author: Vismay Tiwari <vismay.t@gmail.com>
Reviewed-by: Paul Kim <mok03127@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/19523-424457118202f570@postgresql.org
Discussion: https://postgr.es/m/CALHMmB84qkCgv3QAR78YawgfqQZCxSPkRhppxzU=e6fg8RA+AA@mail.gmail.com
Backpatch-through: 18
DROP TABLESPACE checked pg_shdepend for dependent objects without
first locking the tablespace. A concurrent command that recorded a
shared dependency on the tablespace right after that check could still
commit, leaving an object whose pg_shdepend entry (or, for a relation,
pg_class.reltablespace) pointed to a tablespace that no longer existed.
Close the race by having DropTableSpace() take an AccessExclusiveLock
on the tablespace before calling checkSharedDependencies(). That
conflicts with the AccessShareLock shdepLockAndCheckObject() takes when
recording a new dependency, so the loser of the race blocks and
rechecks once the winner commits.
That AccessExclusiveLock creates a new deadlock: ALTER TABLESPACE
RENAME/SET and the internal ACL/owner updates in DROP OWNED and
REASSIGN OWNED touched the catalog tuple without locking the
tablespace, risking a lock-order cycle with DROP. Fix by taking an
AccessShareLock first in all four paths, rechecking pg_shdepend after
any wait in the DROP OWNED and REASSIGN OWNED cases. GRANT, REVOKE,
and ALTER TABLESPACE ... OWNER TO already lock the object.
Add isolation tests covering both orderings of the original race
(dependency-first and drop-first) and all four previously-unlocked
update paths.
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/CAJTYsWXjAQFnGKzXsht3XK8KHhyhontwFJw4JAHsUSfs_ptR4g@mail.gmail.com
Backpatch-through: 14
This reverts commit c06d1a4ba6.
The commit assumed that if the FSM code tolerates torn pages, everything else
does so. Readers that do not tolerate that include RelationCopyStorage(),
used by ALTER TABLE ... SET TABLESPACE for every fork, the read stream in
RelationCopyStorageUsingBuffer() used by CREATE DATABASE ... STRATEGY =
wal_log, and, most awkwardly, the checksum verification in base backups and
pg_checksums.
Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20260901211837.f6.noahmisch%40microsoft.com
Backpatch-through: 14
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
On slow machines, this test can take long enough to generate WAL that a
time-based checkpoint occurs before the primary is stopped. If the
checkpoint record is written to the tail WAL segment that the test later
removes, a standby initialized from the resulting backup tries to read
the missing checkpoint record and fails with a PANIC during startup.
This caused the test to fail on buildfarm member skink.
Fix this by setting checkpoint_timeout high enough to prevent unrelated
checkpoints during the test. This follows the approach used by other
recovery tests, such as 043_no_contrecord_switch.pl, that depend on a
specific WAL layout.
Backpatch to all supported versions.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwFajfjKhvNSTkTcE-wFn30p_A0_i1cvk-Q=FJhDr_5cXA@mail.gmail.com
Discussion: https://postgr.es/m/9ffdb19a-7a89-424e-925a-dd981c37f0ba@gmail.com
Backpatch-through: 14
When creating a nestloop plan for a partitionwise child join, the
outer rel's relids are child relids, but PlaceHolderInfo.ph_eval_at is
always expressed in terms of the topmost parent rels. As a result,
replace_nestloop_params() and identify_current_nestloop_params()
failed to recognize that a PlaceHolderVar evaluated at the outer child
rel can be supplied as a nestloop param. Instead, the Vars within the
PHV's expression were replaced with params, but the outer child rel
emits only the PHV, not those bare Vars, leading to "variable not
found in subplan target list" errors from setrefs.c.
To fix, also include the outer rel's top parent relids in the relid
set used for these checks, so that ph_eval_at comparisons are done in
terms of parent rels while Var checks continue to work in terms of
child rels.
On v18 and later, the required-outer set passed to
identify_current_nestloop_params() has the same problem: it is in
terms of child rels once a parameterized child join path has been
reparameterized by an upper child join. With the above fix in place,
a PlaceHolderVar that depends on both the outer rel and the parameter
source becomes a single NestLoopParam, and that param was never
claimed by any nestloop node, leading to "failed to assign all
NestLoopParams to plan nodes" errors. To fix, also include the top
parents of any child rels in that set. Older branches lack this code
path, so they receive only the first change.
Back-patch to all supported branches.
Bug: #19653
Reported-by: Annie <10215501441@stu.ecnu.edu.cn>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19653-9352cc6ba17b662f@postgresql.org
Backpatch-through: 14
When neither BKPIMAGE_HAS_HOLE nor BKPIMAGE_COMPRESSED is set,
DecodeXLogRecord() checks that bimg_len needs to be equal to BLCKSZ.
However, the associated error message reported the data length
associated to a block (DecodedBkpBlock.data_len), and not the length of
the block (DecodedBkpBlock.bimg_len).
Oversight in 57aa5b2bb1, probably due to some copy-paste from the
surroundings.
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/CAJTYsWVz9ymE7aMt2ZiQvs1bxNvhjfTf+XaJEsdFw7MT5dvtYQ@mail.gmail.com
Backpatch-through: 14
If a LATERAL subquery references a PlaceHolderVar that must be
evaluated at an outer join, the subquery's lateral_relids include that
outer join's relid, since the lateral parameter is the outer join's
output. join_is_legal() verified that the rels named by a proposed
join's minimum parameterization could still be joined to from outside,
but it did not consider such outer-join relids. As a result, when
identity 3 permitted a commuted join order, we could approve a join
that includes part of that outer join's required input, even though
the outer join could then be completed only above the proposed join,
leaving the lateral parameter forever unsatisfiable.
In assert-enabled builds this tripped the backstop Assert in
try_nestloop_path(). In production builds the bogus join generated
only paths whose parameterization can never be satisfied, so they
could never appear in a complete plan. This not only wasted planning
effort, but also could mislead the clauseless-join heuristics into
thinking that legality of this join means that some other join rel
need not be formed, and that could lead to failure to find any plan at
all.
Such joins used to be rejected by the have_dangerous_phv() check in
join_is_legal(), which refused any join where a PlaceHolderVar's eval
set overlapped the other side of the join without being contained in
it. Commit a16ef313f removed that restriction, exposing this
oversight.
To fix, teach join_is_legal() to reject a proposed join if its minimum
parameterization includes an outer-join relid whose outer join cannot
be formed strictly outside the join, that is, when any rel needed to
form that outer join must become part of the proposed join's own join
tree.
Back-patch to v18, where commit a16ef313f removed the
have_dangerous_phv() restriction.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49ZveAYx9T5b0=gxn0pnvqq=MbN-Z4KLbLAE+kH06mWVA@mail.gmail.com
Backpatch-through: 18
Previously, a session that had created temporary objects could hang during
exit if its default transaction mode was SERIALIZABLE READ ONLY DEFERRABLE
and a concurrent serializable transaction was prepared. During backend
exit, temporary-relation cleanup pushed a regular transaction snapshot,
which honored the session's default settings and could wait for a safe
serializable snapshot. So, if the conflicting transaction was prepared,
this wait could last indefinitely.
The wait occurred while the backend was already exiting and interrupts
were held off, so even pg_terminate_backend() could not cancel it. The
backend therefore remained until the prepared transaction was resolved.
Temporary-relation cleanup only needs an active MVCC snapshot for fetching
TOAST data from catalog tuples while dropping temporary objects. It does
not need a transaction snapshot affected by the user's default isolation
settings. So, use a catalog snapshot instead, which provides the needed
protection without entering the deferrable safe-snapshot wait.
Backpatch to all supported versions.
Bug: #19441
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/19441-ec29f3b1363b4a68@postgresql.org
Backpatch-through: 14
The buildfarm member akepa reported a failure in the
031_recovery_conflict.pl test.
The test checked pg_stat_database_conflicts immediately after detecting
a recovery conflict in the standby log. However, the conflict counter is
flushed by the canceled backend during backend exit, so WAL replay
completion and the log message did not guarantee that the updated
statistics are visible yet. So, previously, the test could see a conflict
counter of 0 even though the conflict had already occurred, triggering
the test failure.
Fix this by polling for the expected conflict counter instead of reading
it only once, handling the asynchronous pgstats update.
Per buildfarm member akepa.
Backpatch to v17, where this test is enabled and has the same race.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwHmiLNRfvJDAR=PmxQgf7DbzPSO1M-1RoqO8oy=t2G5KA@mail.gmail.com
Backpatch-through: 17
Not many buildfarm members run this test, since it's gated behind
PG_TEST_EXTRA=xid_wraparound, but of those that do, the slower ones
not infrequently fail. The reason seems to be that the test expects
an INSERT command to either succeed or fail, but there's a window
where it can succeed while issuing a warning about impending
wraparound. poll_query_until treats nonempty stderr as a failure,
so it loops an extra time until the INSERT succeeds with no warning.
There seems no reason to treat this behavior as wrong, so adjust
the test to accept it.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Diagnosed-by: Alexander Lakhin <exclusion@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/7a68bee2-91bd-481d-be44-160e6beebc83@gmail.com
Backpatch-through: 17
Commit 44fb59fc6 taught the grouping-conflict walker to treat the arg
of a simple CASE as a direct operand of each WHEN comparison, but it
only checked the collation, on the assumption that the WHEN operator
is always the type-default "=" and thus matches the grouping eqop.
That assumption fails once the arg is relabeled to another type: the
WHEN then compares under that type's "=", which need not agree with
the grouping equality. For instance, with a DISTINCT over a citext
column, a qual such as "CASE t::text WHEN 'A' THEN ..." was pushed
below the Unique, although the equivalent "t::text = 'A'" is correctly
kept above it.
Instead of special-casing the arg, have the walker bind a Var arg
while walking the WHEN conditions and resolve each CaseTestExpr to it,
so that the arg is checked exactly as each WHEN uses it: with the
opfamily and collation checks of a direct operand when the WHEN is a
comparison, and as a non-operand reference otherwise. A non-Var arg
is walked once as a non-operand, as before. The CaseTestExpr in an
ArrayCoerceExpr's elemexpr and a JsonConstructorExpr's coercion stand
for something else and are left alone.
Reported-by: Tender Wang <tndrwang@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/CAHewXNkvGTOgijRLjmudpg=wz0d-J8ChY2o7ksh3Be+Q_Bxwog@mail.gmail.com
Backpatch-through: 18
When recovery starts from a backup without a signal file, pg_subtrans
is not started at the beginning of recovery and remains unstarted
throughout recovery. However, previously, a restartpoint run by
the checkpointer during recovery nevertheless tried to truncate
pg_subtrans, triggering the assertion failure:
TRAP: failed Assert("TransactionIdIsValid(initial)")
This commit fixes this by tracking whether pg_subtrans has been
started during recovery, and have the checkpointer check this flag
before truncating pg_subtrans at restartpoints.
Backpatch to all supported versions.
Reported-by: Imran Zaheer <imran.zhir@gmail.com>
Author: Imran Zaheer <imran.zhir@gmail.com>
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA+UBfamzfEReT0VOGRUW_=_AecCYQ-CNKLR_T4Q+YEmJAH3fdg@mail.gmail.com
Backpatch-through: 14
Several queries in the foreign_key test sort pg_constraint rows with
"ORDER BY oid::regclass::text". These OIDs are constraint OIDs, not
relation OIDs, so the regclass cast renders them as numeric strings,
and text comparison of numeric strings depends on digit count. If the
OID counter crosses a power of ten while the test runs, the output
order flips, causing spurious test failures. This cannot happen in a
fresh cluster, but installcheck against a long-lived cluster can hit
it.
To fix, sort by constraint name, which is unique within each of these
queries, and use COLLATE "C" so that the order does not depend on the
database's default collation either.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49KaJFGs4rfBWk+YmHPTXZ+pJTMJ12iaz7ruZdSK+sC5w@mail.gmail.com
Backpatch-through: 18
When reduce_outer_joins reduces an outer join to an antijoin, any IS
NULL qual on a Var from the antijoin's nullable side is necessarily
true. Previously, such quals were discarded later in
distribute_qual_to_rels, mainly to avoid bogus selectivity estimates.
But that discard was incomplete: the qual remained in the jointree,
while its Vars were not counted in attr_needed. Since commit
2ebf25e7d, join removal edits the jointree and expects it to contain
no other references to a removed rel, so it could remove a rel that
such a discarded qual still references, and then trip an assertion on
the qual's stale Var.
To fix, move this processing to an earlier phase: such quals are now
removed from the jointree by reduce_outer_joins itself. This way
later phases see a consistent query tree, and
check_redundant_nullability_qual is no longer needed, so remove it.
Back-patch to v16, as with commit 2ebf25e7d.
Reported-by: Tender Wang <tndrwang@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAHewXNk8b0TsSy4dL=CO7FXL2W3WBm0BcdP-zwNJePa-Qj4HzA@mail.gmail.com
Backpatch-through: 16
Several invocations decoded and printed the full WAL range even though
the test only needs to confirm that a command form works or that
decoding reaches a specific error. Limit those checks to one record,
and start the fall-off-the-end checks near the end of the generated WAL.
This change reduces the IPC overhead overall, particularly on Windows,
without reducing coverage.
I am usually hesitant to backpatch such changes as this is only an
improvement, but the gains are too good in terms of IO and runtime, for
both the CI and the buildfarm. Based on the numbers provided, the CI
takes 30% less time to run the test with this change on Windows (worst
case shown on the lists). These tests have been introduced in
96063e2836.
Author: Sehrope Sarkuni <sehrope@jackdb.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/CAH7T-araSEdsNpxiKaMOW8kr_ZHhekCLHx5yzm2ksq4FdgULbA@mail.gmail.com
Backpatch-through: 17
A negative n means "return all but the first |n| characters", so
text_right() negates n before clipping. Negating PG_INT32_MIN
overflows; with -fwrapv the result is PG_INT32_MIN again, still
negative, and pg_mbcharcliplen() then returns an offset of zero,
so the whole string is returned where the correct answer is an
empty string:
SELECT right('abcdef', (-2147483648)::int4); -- 'abcdef', want ''
SELECT right('abcdef', -2147483647); -- '', correct
Clamp to PG_INT32_MAX instead. Any n whose absolute value is at
least the string's length skips all of it, and a text value cannot
be longer than PG_INT32_MAX, so this gives the same answer for every
other input. Erroring out, as text_format_string_conversion() does
for a width of INT_MIN, would not be correct here: unlike a format
width, an out-of-range skip count has a well-defined result.
Using pg_neg_s32_overflow() would be a slightly more optimal fix but
as it's only available in PostgreSQL 18 and later the decision was
taken to apply the same fix to all backbranches.
Backpatch to all supported versions.
Author: Ewan Young <kdbase.hack@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAON2xHNnBz-AcPJgDmd5_39+8qR5AUKEZk4X3ZM-0zdsATn8kQ@mail.gmail.com
Backpatch-through: 14
When to_char() formatted an integer value with a V pattern, it could
return an incorrect result instead of reporting an overflow. V shifts
the decimal point by multiplying the input value by a power of ten before
formatting it, so, for example,
to_char(3, '9V999999999')
requires computing 3 * 10^9. This result does not fit in int4, but
the integer variant of to_char() performed the multiplication using a
plain int32 expression. The intermediate result could therefore
overflow, causing the function to output incorrect digits instead of
raising "integer out of range".
Use dtoi4() and int4mul() for this calculation so that both an
out-of-range multiplier and an out-of-range product are detected, as
with ordinary integer arithmetic. This also matches the existing int8
implementation, which uses dtoi8() and int8mul() for the same
operation.
After this change, to_char() with V format either returns the
correctly formatted result when the scaled value fits in int4, or
raises "integer out of range" when it does not.
Backpatch to all supported versions.
Reported-by: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Author: Andrey Rachitskiy <pl0h0yp1@gmail.com>
Reviewed-by: Miłosz Bieniek <bieniek.milosz@proton.me>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAB8bMivEfqZxOVdzc3kZDN++XshmkEz2t7dfGBU8+oUm864EZg@mail.gmail.com
Backpatch-through: 14
The compound flags collected from COMPOUNDFLAG and friends are stored in
either the string or the integer member of a union, according to the
flag mode that the affix file's FLAG line declares. NIImportOOAffixes()
converted each flag as soon as it read it, using the mode in effect at
that point, and recorded that mode in the entry. Since FLAG may appear
anywhere in the file, including after the compound flags, entries written
before and after it could disagree about which member of the union holds
the flag.
In assert-enabled builds, this would result in an assertion failure.
Otherwise, cmpcmdflag() takes the mode from its first argument and
applies it to both, so it can read an integer as a char pointer and pass
that to strcmp(). Depending on which way the mismatch goes, the result
is a segfault while sorting the array, a segfault in the bsearch() that
later looks flags up (the lookup key is built with the final mode, so
this happens even when the array itself is consistent), or, when both
members happen to be readable, no crash at all and a compound flag that
is never found, which silently disables compound word splitting. This
isn't a security bug because we consider dictionary files to be trusted
data, but it's still worth fixing. (In practice, dictionary files
usually put the FLAG line first, which is why this went unreported for
so long.)
Fix by keeping the flags as strings while the file is read and converting
them once it has been read in full, when the mode is final. This also
makes the position of the FLAG line irrelevant, which is how the flags on
AF, SFX and PFX lines are already treated: those are parsed in a second
pass and so always use the final mode. That precedent is reason for
behaving this way rather than throwing an error.
The old ispell file format reaches addCompoundAffixFlagValue() too,
from NIImportAffixes(), and returns without entering NIImportOOAffixes(),
so it needs the conversion step as well.
While we're here, also fix some integer width mismatches: store the
result of strtol() into a "long", and cast to int only after we've done
range checks. Typically a value too wide for int would fail the range
checks anyway, but in some cases it would be silently accepted after
truncation to int.
Author: Ewan Young <kdbase.hack@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAON2xHN3QmsaySM6DGWa1gttcbJoFh0wjAE-_ZpSPo=LKN1hYw@mail.gmail.com
Backpatch-through: 14
analyzejoins.c decided which joins could be dropped by consulting the
planner's derived data structures, but then implemented the removal
by updating those structures in-place. That is a lot of fiddly work,
and nothing keeps it in step with the rest of the planner:
remove_leftjoinrel_from_query only bothered to update "parts of the
planner's data structures that will actually be consulted later", with
no good way to know what those are. Bug #19560 is one consequence.
In that report, removing a join leaves an EquivalenceClass that now
gives rise to a base restriction clause, but base restriction clauses
have already been generated and nothing reconsiders them, so the WHERE
condition disappears from the plan and we return wrong answers.
The self-join elimination code has the same design and the same type
of hazard. We have seen many related bugs over the years too, so it's
time to do something drastic.
To fix, do the removals by editing root->parse->jointree (which is a
far simpler and more stable representation than the derived data),
and then have query_planner() discard everything it computed from the
jointree and derive it over again. This requires quite a bit less
code, and doesn't require touching analyzejoins.c every time we change
the data derived by query_planner(). For typical cases it can actually
save a bit of planning time, though in cases where we have to iterate
the derivation loop many times it does add some time.
reduce_unique_semijoins() gets the same treatment: rather than deleting
the semijoin's SpecialJoinInfo and relying on the jointree not being
consulted again, it now changes the JoinExpr's jointype to JOIN_INNER
and recalculates everything.
Some plans change in the join regression test. Qual evaluation order
shifts in a few cases, because the conditions now reach later planning
in jointree order rather than in whatever order the removal code
re-distributed them. A few plans improve, since the rebuilt relation
targetlists no longer carry columns that only a removed join needed.
We also detect a constant-false filter condition whose test used to
carry a FIXME label. One plan gets marginally worse, because the old
code recomputed attr_needed from equivalence classes after a join
removal; that is more accurate than what deconstruct_jointree()
derives from the original clauses, but we no longer do that. Making
that recomputation happen anyway could be worth doing, but it should
be considered independently and perhaps implemented differently.
Back-patch to v16, on the grounds that the introduction of
varnullingrels in v16 made the old approach significantly more complex
and bug-prone; notably, bug #19560 does not manifest before v16.
In released branches, do not remove externally-visible fixup
functions such as remove_join_clause_from_rels, in case any
extensions are relying on them; but they're no longer used by core
code. But we must nonetheless break API/ABI for remove_useless_joins,
reduce_unique_semijoins, and remove_useless_self_joins, as those now
have different outputs and very different behavior than before.
It seems unlikely that any extensions are calling those; but just in
case, make the breakage more obvious by renaming remove_useless_joins
to remove_useless_outer_joins, which is a more sensible name for it
anyway since the addition of remove_useless_self_joins.
Full disclosure: initial drafts of this patch were made with
Claude Opus 4.8.
Bug: #19560
Reported-by: Orestis Markou <orestis@orestis.gr>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Thom Brown <thom@linux.com>
Reviewed-by: Jacob Brazeal <jacob.brazeal@gmail.com>
Discussion: https://postgr.es/m/1186816.1784573544@sss.pgh.pa.us
Backpatch-through: 16
