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2023-09-15Track nesting depth correctly when drilling down into RECORD Vars.Tom Lane
expandRecordVariable() failed to adjust the parse nesting structure correctly when recursing to inspect an outer-level Var. This could result in assertion failures or core dumps in corner cases. Likewise, get_name_for_var_field() failed to adjust the deparse namespace stack correctly when recursing to inspect an outer-level Var. In this case the likely result was a "bogus varno" error while deparsing a view. Per bug #18077 from Jingzhou Fu. Back-patch to all supported branches. Richard Guo, with some adjustments by me Discussion: https://postgr.es/m/18077-b9db97c6e0ab45d8@postgresql.org
2023-08-24Avoid unnecessary plancache revalidation of utility statements.Tom Lane
Revalidation of a plancache entry (after a cache invalidation event) requires acquiring a snapshot. Normally that is harmless, but not if the cached statement is one that needs to run without acquiring a snapshot. We were already aware of that for TransactionStmts, but for some reason hadn't extrapolated to the other statements that PlannedStmtRequiresSnapshot() knows mustn't set a snapshot. This can lead to unexpected failures of commands such as SET TRANSACTION ISOLATION LEVEL. We can fix it in the same way, by excluding those command types from revalidation. However, we can do even better than that: there is no need to revalidate for any statement type for which parse analysis, rewrite, and plan steps do nothing interesting, which is nearly all utility commands. To mechanize this, invent a parser function stmt_requires_parse_analysis() that tells whether parse analysis does anything beyond wrapping a CMD_UTILITY Query around the raw parse tree. If that's what it does, then rewrite and plan will just skip the Query, so that it is not possible for the same raw parse tree to produce a different plan tree after cache invalidation. stmt_requires_parse_analysis() is basically equivalent to the existing function analyze_requires_snapshot(), except that for obscure reasons that function omits ReturnStmt and CallStmt. It is unclear whether those were oversights or intentional. I have not been able to demonstrate a bug from not acquiring a snapshot while analyzing these commands, but at best it seems mighty fragile. It seems safer to acquire a snapshot for parse analysis of these commands too, which allows making stmt_requires_parse_analysis and analyze_requires_snapshot equivalent. In passing this fixes a second bug, which is that ResetPlanCache would exclude ReturnStmts and CallStmts from revalidation. That's surely *not* safe, since they contain parsable expressions. Per bug #18059 from Pavel Kulakov. Back-patch to all supported branches. Discussion: https://postgr.es/m/18059-79c692f036b25346@postgresql.org
2023-04-28Fix crashes with CREATE SCHEMA AUTHORIZATION and schema elementsMichael Paquier
CREATE SCHEMA AUTHORIZATION with appended schema elements can lead to crashes when comparing the schema name of the query with the schemas used in the qualification of some clauses in the elements' queries. The origin of the problem is that the transformation routine for the elements listed in a CREATE SCHEMA query uses as new, expected, schema name the one listed in CreateSchemaStmt itself. However, depending on the query, CreateSchemaStmt.schemaname may be NULL, being computed instead from the role specification of the query given by the AUTHORIZATION clause, that could be either: - A user name string, with the new schema name being set to the same value as the role given. - Guessed from CURRENT_ROLE, SESSION_ROLE or CURRENT_ROLE, with a new schema name computed from the security context where CREATE SCHEMA is running. Regression tests are added for CREATE SCHEMA with some appended elements (some of them with schema qualifications), covering also some role specification patterns. While on it, this simplifies the context structure used during the transformation of the elements listed in a CREATE SCHEMA query by removing the fields for the role specification and the role type. They were not used, and for the role specification this could be confusing as the schema name may by extracted from that at the beginning of CreateSchemaCommand(). This issue exists for a long time, so backpatch down to all the versions supported. Reported-by: Song Hongyu Author: Michael Paquier Reviewed-by: Richard Guo Discussion: https://postgr.es/m/17909-f65c12dfc5f0451d@postgresql.org Backpatch-through: 11
2023-03-31Fix List memory issue in transformColumnDefinitionDavid Rowley
When calling generateSerialExtraStmts(), we would pass in the constraint->options. In some cases, generateSerialExtraStmts() would modify the referenced List to remove elements from it, but doing so is invalid without assigning the list back to all variables that point to it. In the particular reported problem case, the List became empty, in which cases it became NIL, but the passed in constraint->options didn't get to find out about that and was left pointing to free'd memory. To fix this, just perform a list_copy() inside generateSerialExtraStmts(). We could just do a list_copy() just before we perform the delete from the list, however, that seems less robust. Let's make sure the generated CreateSeqStmt gets a completely different copy of the list to be safe. Bug: #17879 Reported-by: Fei Changhong Diagnosed-by: Fei Changhong Discussion: https://postgr.es/m/17879-b7dfb5debee58ff5@postgresql.org Backpatch-through: 11, all supported versions
2023-03-13Fix failure to detect some cases of improperly-nested aggregates.Tom Lane
check_agg_arguments_walker() supposed that it needn't descend into the arguments of a lower-level aggregate function, but this is just wrong in the presence of multiple levels of sub-select. The oversight would lead to executor failures on queries that should be rejected. (Prior to v11, they actually were rejected, thanks to a "redundant" execution-time check.) Per bug #17835 from Anban Company. Back-patch to all supported branches. Discussion: https://postgr.es/m/17835-4f29f3098b2d0ba4@postgresql.org
2023-03-07Fix more bugs caused by adding columns to the end of a view.Tom Lane
If a view is defined atop another view, and then CREATE OR REPLACE VIEW is used to add columns to the lower view, then when the upper view's referencing RTE is expanded by ApplyRetrieveRule we will have a subquery RTE with fewer eref->colnames than output columns. This confuses various code that assumes those lists are always in sync, as they are in plain parser output. We have seen such problems before (cf commit d5b760ecb), and now I think the time has come to do what was speculated about in that commit: let's make ApplyRetrieveRule synthesize some column names to preserve the invariant that holds in parser output. Otherwise we'll be chasing this class of bugs indefinitely. Moreover, it appears from testing that this actually gives us better results in the test case d5b760ecb added, and likely in other corner cases that we lack coverage for. In HEAD, I replaced d5b760ecb's hack to make expandRTE exit early with an elog(ERROR) call, since the case is now presumably unreachable. But it seems like changing that in back branches would bring more risk than benefit, so there I just updated the comment. Per bug #17811 from Alexander Lakhin. Back-patch to all supported branches. Discussion: https://postgr.es/m/17811-d31686b78f0dffc9@postgresql.org
2022-12-16Fix inability to reference CYCLE column from inside its CTE.Tom Lane
Such references failed with "cache lookup failed for type 0" because we didn't resolve the type of the CYCLE column until after analyzing the CTE's query. We can just move that processing to before the recursive parse_sub_analyze call, though. While here, invent a couple of local variables to make this code less egregiously wider-than-80-columns. Per bug #17723 from Vik Fearing. Back-patch to v14 where the CYCLE feature was added. Discussion: https://postgr.es/m/17723-2c4985ff111e7bba@postgresql.org
2022-10-16Rename parser token REF to REF_P to avoid a symbol conflict.Tom Lane
In the latest version of Apple's macOS SDK, <sys/socket.h> fails to compile if "REF" is #define'd as something. Apple may or may not agree that this is a bug, and even if they do accept the bug report I filed, they probably won't fix it very quickly. In the meantime, our back branches will all fail to compile gram.y. v15 and HEAD currently escape the problem thanks to the refactoring done in 98e93a1fc, but that's purely accidental. Moreover, since that patch removed a widely-visible inclusion of <netdb.h>, back-patching it seems too likely to break third-party code. Instead, change the token's code name to REF_P, following our usual convention for naming parser tokens that are likely to have symbol conflicts. The effects of that should be localized to the grammar and immediately surrounding files, so it seems like a safer answer. Per project policy that we want to keep recently-out-of-support branches buildable on modern systems, back-patch all the way to 9.2. Discussion: https://postgr.es/m/1803927.1665938411@sss.pgh.pa.us
2022-09-20Suppress variable-set-but-not-used warnings from clang 15.Tom Lane
clang 15+ will issue a set-but-not-used warning when the only use of a variable is in autoincrements (e.g., "foo++;"). That's perfectly sensible, but it detects a few more cases that we'd not noticed before. Silence the warnings with our usual methods, such as PG_USED_FOR_ASSERTS_ONLY, or in one case by actually removing a useless variable. One thing that we can't nicely get rid of is that with %pure-parser, Bison emits "yynerrs" as a local variable that falls foul of this warning. To silence those, I inserted "(void) yynerrs;" in the top-level productions of affected grammars. Per recently-established project policy, this is a candidate for back-patching into out-of-support branches: it suppresses annoying compiler warnings but changes no behavior. Hence, back-patch to 9.5, which is as far as these patches go without issues. (A preliminary check shows that the prior branches need some other set-but-not-used cleanups too, so I'll leave them for another day.) Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us
2022-08-13Catch stack overflow when recursing in transformFromClauseItem().Tom Lane
Most parts of the parser can expect that the stack overflow check in transformExprRecurse() will trigger before things get desperate. However, transformFromClauseItem() can recurse directly to self without having analyzed any expressions, so it's possible to drive it to a stack-overrun crash. Add a check to prevent that. Per bug #17583 from Egor Chindyaskin. Back-patch to all supported branches. Richard Guo Discussion: https://postgr.es/m/17583-33be55b9f981f75c@postgresql.org
2022-08-08In extensions, don't replace objects not belonging to the extension.Tom Lane
Previously, if an extension script did CREATE OR REPLACE and there was an existing object not belonging to the extension, it would overwrite the object and adopt it into the extension. This is problematic, first because the overwrite is probably unintentional, and second because we didn't change the object's ownership. Thus a hostile user could create an object in advance of an expected CREATE EXTENSION command, and would then have ownership rights on an extension object, which could be modified for trojan-horse-type attacks. Hence, forbid CREATE OR REPLACE of an existing object unless it already belongs to the extension. (Note that we've always forbidden replacing an object that belongs to some other extension; only the behavior for previously-free-standing objects changes here.) For the same reason, also fail CREATE IF NOT EXISTS when there is an existing object that doesn't belong to the extension. Our thanks to Sven Klemm for reporting this problem. Security: CVE-2022-2625
2022-08-01Check maximum number of columns in function RTEs, too.Tom Lane
I thought commit fd96d14d9 had plugged all the holes of this sort, but no, function RTEs could produce oversize tuples too, either via long coldeflists or just from multiple functions in one RTE. (I'm pretty sure the other variants of base RTEs aren't a problem, because they ultimately refer to either a table or a sub-SELECT, whose widths are enforced elsewhere. But we explicitly allow join RTEs to be overwidth, as long as you don't try to form their tuple result.) Per further discussion of bug #17561. As before, patch all branches. Discussion: https://postgr.es/m/17561-80350151b9ad2ad4@postgresql.org
2022-07-29In transformRowExpr(), check for too many columns in the row.Tom Lane
A RowExpr with more than MaxTupleAttributeNumber columns would fail at execution anyway, since we cannot form a tuple datum with more than that many columns. While heap_form_tuple() has a check for too many columns, it emerges that there are some intermediate bits of code that don't check and can be driven to failure with sufficiently many columns. Checking this at parse time seems like the most appropriate place to install a defense, since we already check SELECT list length there. While at it, make the SELECT-list-length error use the same errcode (TOO_MANY_COLUMNS) as heap_form_tuple does, rather than the generic PROGRAM_LIMIT_EXCEEDED. Per bug #17561 from Egor Chindyaskin. The given test case crashes in all supported branches (and probably a lot further back), so patch all. Discussion: https://postgr.es/m/17561-80350151b9ad2ad4@postgresql.org
2022-07-21Fix ruleutils issues with dropped cols in functions-returning-composite.Tom Lane
Due to lack of concern for the case in the dependency code, it's possible to drop a column of a composite type even though stored queries have references to the dropped column via functions-in-FROM that return the composite type. There are "soft" references, namely FROM-clause aliases for such columns, and "hard" references, that is actual Vars referring to them. The right fix for hard references is to add dependencies preventing the drop; something we've known for many years and not done (and this commit still doesn't address it). A "soft" reference shouldn't prevent a drop though. We've been around on this before (cf. 9b35ddce9, 2c4debbd0), but nobody had noticed that the current behavior can result in dump/reload failures, because ruleutils.c can print more column aliases than the underlying composite type now has. So we need to rejigger the column-alias-handling code to treat such columns as dropped and not print aliases for them. Rather than writing new code for this, I used expandRTE() which already knows how to figure out which function result columns are dropped. I'd initially thought maybe we could use expandRTE() in all cases, but that fails for EXPLAIN's purposes, because the planner strips a lot of RTE infrastructure that expandRTE() needs. So this patch just uses it for unplanned function RTEs and otherwise does things the old way. If there is a hard reference (Var), then removing the column alias causes us to fail to print the Var, since there's no longer a name to print. Failing seems less desirable than printing a made-up name, so I made it print "?dropped?column?" instead. Per report from Timo Stolz. Back-patch to all supported branches. Discussion: https://postgr.es/m/5c91267e-3b6d-5795-189c-d15a55d61dbb@nullachtvierzehn.de
2022-07-07Fix alias matching in transformLockingClause().Dean Rasheed
When locking a specific named relation for a FOR [KEY] UPDATE/SHARE clause, transformLockingClause() finds the relation to lock by scanning the rangetable for an RTE with a matching eref->aliasname. However, it failed to account for the visibility rules of a join RTE. If a join RTE doesn't have a user-supplied alias, it will have a generated eref->aliasname of "unnamed_join" that is not visible as a relation name in the parse namespace. Such an RTE needs to be skipped, otherwise it might be found in preference to a regular base relation with a user-supplied alias of "unnamed_join", preventing it from being locked. In addition, if a join RTE doesn't have a user-supplied alias, but does have a join_using_alias, then the RTE needs to be matched using that alias rather than the generated eref->aliasname, otherwise a misleading "relation not found" error will be reported rather than a "join cannot be locked" error. Backpatch all the way, except for the second part which only goes back to 14, where JOIN USING aliases were added. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCUY_KOBnqxbTSPf=7fz9HWPnZ5Xgb9SwYzZ8rFXe7nb=w@mail.gmail.com
2022-05-18Check column list length in XMLTABLE/JSON_TABLE aliasAlvaro Herrera
We weren't checking the length of the column list in the alias clause of an XMLTABLE or JSON_TABLE function (a "tablefunc" RTE), and it was possible to make the server crash by passing an overly long one. Fix it by throwing an error in that case, like the other places that deal with alias lists. In passing, modify the equivalent test used for join RTEs to look like the other ones, which was different for no apparent reason. This bug came in when XMLTABLE was born in version 10; backpatch to all stable versions. Reported-by: Wang Ke <krking@zju.edu.cn> Discussion: https://postgr.es/m/17480-1c9d73565bb28e90@postgresql.org
2022-05-09Fix core dump in transformValuesClause when there are no columns.Tom Lane
The parser code that transformed VALUES from row-oriented to column-oriented lists failed if there were zero columns. You can't write that straightforwardly (though probably you should be able to), but the case can be reached by expanding a "tab.*" reference to a zero-column table. Per bug #17477 from Wang Ke. Back-patch to all supported branches. Discussion: https://postgr.es/m/17477-0af3c6ac6b0a6ae0@postgresql.org
2022-04-18Avoid invalid array reference in transformAlterTableStmt().Tom Lane
Don't try to look at the attidentity field of system attributes, because they're not there in the TupleDescAttr array. Sometimes this is harmless because we accidentally pick up a zero, but otherwise we'll report "no owned sequence found" from an attempt to alter a system attribute. (It seems possible that a SIGSEGV could occur, too, though I've not seen it in testing.) It's not in this function's charter to complain that you can't alter a system column, so instead just hard-wire an assumption that system attributes aren't identities. I didn't bother with a regression test because the appearance of the bug is very erratic. Per bug #17465 from Roman Zharkov. Back-patch to all supported branches. (There's not actually a live bug before v12, because before that get_attidentity() did the right thing anyway. But for consistency I changed the test in the older branches too.) Discussion: https://postgr.es/m/17465-f2a554a6cb5740d3@postgresql.org
2022-01-29Fix failure to validate the result of select_common_type().Tom Lane
Although select_common_type() has a failure-return convention, an apparent successful return just provides a type OID that *might* work as a common supertype; we've not validated that the required casts actually exist. In the mainstream use-cases that doesn't matter, because we'll proceed to invoke coerce_to_common_type() on each input, which will fail appropriately if the proposed common type doesn't actually work. However, a few callers didn't read the (nonexistent) fine print, and thought that if they got back a nonzero OID then the coercions were sure to work. This affects in particular the recently-added "anycompatible" polymorphic types; we might think that a function/operator using such types matches cases it really doesn't. A likely end result of that is unexpected "ambiguous operator" errors, as for example in bug #17387 from James Inform. Another, much older, case is that the parser might try to transform an "x IN (list)" construct to a ScalarArrayOpExpr even when the list elements don't actually have a common supertype. It doesn't seem desirable to add more checking to select_common_type itself, as that'd just slow down the mainstream use-cases. Instead, write a separate function verify_common_type that performs the missing checks, and add a call to that where necessary. Likewise add verify_common_type_from_oids to go with select_common_type_from_oids. Back-patch to v13 where the "anycompatible" types came in. (The symptom complained of in bug #17387 doesn't appear till v14, but that's just because we didn't get around to converting || to use anycompatible till then.) In principle the "x IN (list)" fix could go back all the way, but I'm not currently convinced that it makes much difference in real-world cases, so I won't bother for now. Discussion: https://postgr.es/m/17387-5dfe54b988444963@postgresql.org
2021-12-30Revert b2a459edf "Fix GRANTED BY support in REVOKE ROLE statements"Daniel Gustafsson
The reverted commit attempted to fix SQL specification compliance for the cases which 6aaaa76bb left. This however broke existing behavior which takes precedence over spec compliance so revert. The introduced tests are left after the revert since the codepath isn't well covered. Per bug report 17346. Backpatch down to 14 where it was introduced. Reported-by: Andrew Bille <andrewbille@gmail.com> Discussion: https://postgr.es/m/17346-f72b28bd1a341060@postgresql.org
2021-12-16Ensure casting to typmod -1 generates a RelabelType.Tom Lane
Fix the code changed by commit 5c056b0c2 so that we always generate RelabelType, not something else, for a cast to unspecified typmod. Otherwise planner optimizations might not happen. It appears we missed this point because the previous experiments were done on type numeric: the parser undesirably generates a call on the numeric() length-coercion function, but then numeric_support() optimizes that down to a RelabelType, so that everything seems fine. It misbehaves for types that have a non-optimized length coercion function, such as bpchar. Per report from John Naylor. Back-patch to all supported branches, as the previous patch eventually was. Unfortunately, that no longer includes 9.6 ... we really shouldn't put this type of change into a nearly-EOL branch. Discussion: https://postgr.es/m/CAFBsxsEfbFHEkouc+FSj+3K1sHipLPbEC67L0SAe-9-da8QtYg@mail.gmail.com
2021-11-26Fix GRANTED BY support in REVOKE ROLE statementsDaniel Gustafsson
Commit 6aaaa76bb added support for the GRANTED BY clause in GRANT and REVOKE statements, but missed adding support for checking the role in the REVOKE ROLE case. Fix by checking that the parsed role matches the CURRENT_ROLE/CURRENT_USER requirement, and also add some tests for it. Backpatch to v14 where GRANTED BY support was introduced. Discussion: https://postgr.es/m/B7F6699A-A984-4943-B9BF-CEB84C003527@yesql.se Backpatch-through: 14
2021-11-02Avoid O(N^2) behavior in SyncPostCheckpoint().Tom Lane
As in commits 6301c3ada and e9d9ba2a4, avoid doing repetitive list_delete_first() operations, since that would be expensive when there are many files waiting to be unlinked. This is a slightly larger change than in those cases. We have to keep the list state valid for calls to AbsorbSyncRequests(), so it's necessary to invent a "canceled" field instead of immediately deleting PendingUnlinkEntry entries. Also, because we might not be able to process all the entries, we need a new list primitive list_delete_first_n(). list_delete_first_n() is almost list_copy_tail(), but it modifies the input List instead of making a new copy. I found a couple of existing uses of the latter that could profitably use the new function. (There might be more, but the other callers look like they probably shouldn't overwrite the input List.) As before, back-patch to v13. Discussion: https://postgr.es/m/CD2F0E7F-9822-45EC-A411-AE56F14DEA9F@amazon.com
2021-10-19Remove bogus assertion in transformExpressionList().Tom Lane
I think when I added this assertion (in commit 8f889b108), I was only thinking of the use of transformExpressionList at top level of INSERT and VALUES. But it's also called by transformRowExpr(), which can certainly occur in an UPDATE targetlist, so it's inappropriate to suppose that p_multiassign_exprs must be empty. Besides, since the input is not expected to contain ResTargets, there's no reason it should contain MultiAssignRefs either. Hence this code need not be concerned about the state of p_multiassign_exprs, and we should just drop the assertion. Per bug #17236 from ocean_li_996. It's been wrong for years, so back-patch to all supported branches. Discussion: https://postgr.es/m/17236-3210de9bcba1d7ca@postgresql.org
2021-10-01Error out if SKIP LOCKED and WITH TIES are both specifiedAlvaro Herrera
Both bugs #16676[1] and #17141[2] illustrate that the combination of SKIP LOCKED and FETCH FIRST WITH TIES break expectations when it comes to rows returned to other sessions accessing the same row. Since this situation is detectable from the syntax and hard to fix otherwise, forbid for now, with the potential to fix in the future. [1] https://postgr.es/m/16676-fd62c3c835880da6@postgresql.org [2] https://postgr.es/m/17141-913d78b9675aac8e@postgresql.org Backpatch-through: 13, where WITH TIES was introduced Author: David Christensen <david.christensen@crunchydata.com> Discussion: https://postgr.es/m/CAOxo6XLPccCKru3xPMaYDpa+AXyPeWFs+SskrrL+HKwDjJnLhg@mail.gmail.com
2021-09-29Clarify use of "statistics objects" in the codeMichael Paquier
The code inconsistently used "statistic object" or "statistics" where the correct term, as discussed, is actually "statistics object". This improves the state of the code to be more consistent. While on it, fix an incorrect error message introduced in a4d75c8. This error should never happen, as the code states, but it would be misleading. Author: Justin Pryzby Reviewed-by: Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/20210924215827.GS831@telsasoft.com Backpatch-through: 14
2021-09-08Disable anonymous record hash support except in special casesPeter Eisentraut
Commit 01e658fa74 added hash support for row types. This also added support for hashing anonymous record types, using the same approach that the type cache uses for comparison support for record types: It just reports that it works, but it might fail at run time if a component type doesn't actually support the operation. We get away with that for comparison because most types support that. But some types don't support hashing, so the current state can result in failures at run time where the planner chooses hashing over sorting, whereas that previously worked if only sorting was an option. We do, however, want the record hashing support for path tracking in recursive unions, and the SEARCH and CYCLE clauses built on that. In that case, hashing is the only plan option. So enable that, this commit implements the following approach: The type cache does not report that hashing is available for the record type. This undoes that part of 01e658fa74. Instead, callers that require hashing no matter what can override that result themselves. This patch only touches the callers to make the aforementioned recursive query cases work, namely the parse analysis of unions, as well as the hash_array() function. Reported-by: Sait Talha Nisanci <sait.nisanci@microsoft.com> Bug: #17158 Discussion: https://www.postgresql.org/message-id/flat/17158-8a2ba823982537a4%40postgresql.org
2021-08-25Avoid using ambiguous word "positive" in error message.Fujii Masao
There are two identical error messages about valid value of modulus for hash partition, in PostgreSQL source code. Commit 0e1275fb07 improved only one of them so that ambiguous word "positive" was avoided there, and forgot to improve the other. This commit improves the other. Which would reduce translator burden. Back-pach to v11 where the error message exists. Author: Kyotaro Horiguchi Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/20210819.170315.1413060634876301811.horikyota.ntt@gmail.com
2021-08-19Avoid trying to lock OLD/NEW in a rule with FOR UPDATE.Tom Lane
transformLockingClause neglected to exclude the pseudo-RTEs for OLD/NEW when processing a rule's query. This led to odd errors or even crashes later on. This bug is very ancient, but it's not terribly surprising that nobody noticed, since the use-case for SELECT FOR UPDATE in a non-view rule is somewhere between thin and non-existent. Still, crashing is not OK. Per bug #17151 from Zhiyong Wu. Thanks to Masahiko Sawada for analysis of the problem. Discussion: https://postgr.es/m/17151-c03a3e6e4ec9aadb@postgresql.org
2021-08-18Fix check_agg_arguments' examination of aggregate FILTER clauses.Tom Lane
Recursion into the FILTER clause was mis-implemented, such that a relevant Var or Aggref at the very top of the FILTER clause would be ignored. (Of course, that'd have to be a plain boolean Var or boolean-returning aggregate.) The consequence would be mis-identification of the correct semantic level of the aggregate, which could lead to not-per-spec query behavior. If the FILTER expression is an aggregate, this could also lead to failure to issue an expected "aggregate function calls cannot be nested" error, which would likely result in a core dump later on, since the planner and executor aren't expecting such cases to appear. The root cause is that commit b560ec1b0 blindly copied some code that assumed it's recursing into a List, and thus didn't examine the top-level node. To forestall questions about why this call doesn't look like the others, as well as possible future copy-and-paste mistakes, let's change all three check_agg_arguments_walker calls in check_agg_arguments, even though only the one for the filter clause is really broken. Per bug #17152 from Zhiyong Wu. This has been wrong since we implemented FILTER, so back-patch to all supported versions. (Testing suggests that pre-v11 branches manage to avoid crashing in the bad-Aggref case, thanks to "redundant" checks in ExecInitAgg. But I'm not sure how thorough that protection is, and anyway the wrong-behavior issue remains, so fix 9.6 and 10 too.) Discussion: https://postgr.es/m/17152-c7f906cc1a88e61b@postgresql.org
2021-08-06Don't elide casting to typmod -1.Tom Lane
Casting a value that's already of a type with a specific typmod to an unspecified typmod doesn't do anything so far as run-time behavior is concerned. However, it really ought to change the exposed type of the expression to match. Up to now, coerce_type_typmod hasn't bothered with that, which creates gotchas in contexts such as recursive unions. If for example one side of the union is numeric(18,3), but it needs to be plain numeric to match the other side, there's no direct way to express that. This is easy enough to fix, by inserting a RelabelType to update the exposed type of the expression. However, it's a bit nervous-making to change this behavior, because it's stood for a really long time. (I strongly suspect that it's like this in part because the logic pre-dates the introduction of RelabelType in 7.0. The commit log message for 57b30e8e2 is interesting reading here.) As a compromise, we'll sneak the change into 14beta3, and consider back-patching to stable branches if no complaints emerge in the next three months. Discussion: https://postgr.es/m/CABNQVagu3bZGqiTjb31a8D5Od3fUMs7Oh3gmZMQZVHZ=uWWWfQ@mail.gmail.com
2021-07-27Fix bugs in polymorphic-argument resolution for multiranges.Tom Lane
We failed to deal with an UNKNOWN-type input for anycompatiblemultirange; that should throw an error indicating that we don't know how to resolve the multirange type. We also failed to infer the type of an anycompatiblerange output from an anycompatiblemultirange input or vice versa. Per bug #17066 from Alexander Lakhin. Back-patch to v14 where multiranges were added. Discussion: https://postgr.es/m/17066-16a37f6223a8470b@postgresql.org
2021-06-21Fix assert failure in expand_grouping_setsDavid Rowley
linitial_node() fails in assert enabled builds if the given pointer is not of the specified type. Here the type is IntList. The code thought it should be expecting List, but it was wrong. In the existing tests which run this code the initial list element is always NIL. Since linitial_node() allows NULL, we didn't trigger any assert failures in the existing regression tests. There is still some discussion as to whether we need a few more tests in this area, but for now, since beta2 is looming, fix the bug first. Bug: #17067 Discussion: https://postgr.es/m/17067-665d50fa321f79e0@postgresql.org Reported-by: Yaoguang Chen
2021-06-18Centralize the logic for protective copying of utility statements.Tom Lane
In the "simple Query" code path, it's fine for parse analysis or execution of a utility statement to scribble on the statement's node tree, since that'll just be thrown away afterwards. However it's not fine if the node tree is in the plan cache, as then it'd be corrupted for subsequent executions. Up to now we've dealt with that by having individual utility-statement functions apply copyObject() if they were going to modify the tree. But that's prone to errors of omission. Bug #17053 from Charles Samborski shows that CREATE/ALTER DOMAIN didn't get this memo, and can crash if executed repeatedly from plan cache. In the back branches, we'll just apply a narrow band-aid for that, but in HEAD it seems prudent to have a more principled fix that will close off the possibility of other similar bugs in future. Hence, let's hoist the responsibility for doing copyObject up into ProcessUtility from its children, thus ensuring that it happens for all utility statement types. Also, modify ProcessUtility's API so that its callers can tell it whether a copy step is necessary. It turns out that in all cases, the immediate caller knows whether the node tree is transient, so this doesn't involve a huge amount of code thrashing. In this way, while we lose a little bit in the execute-from-cache code path due to sometimes copying node trees that wouldn't be mutated anyway, we gain something in the simple-Query code path by not copying throwaway node trees. Statements that are complex enough to be expensive to copy are almost certainly ones that would have to be copied anyway, so the loss in the cache code path shouldn't be much. (Note that this whole problem applies only to utility statements. Optimizable statements don't have the issue because we long ago made the executor treat Plan trees as read-only. Perhaps someday we will make utility statement execution act likewise, but I'm not holding my breath.) Discussion: https://postgr.es/m/931771.1623893989@sss.pgh.pa.us Discussion: https://postgr.es/m/17053-3ca3f501bbc212b4@postgresql.org
2021-06-10Change position of field "transformed" in struct CreateStatsStmt.Noah Misch
Resolve the disagreement with nodes/*funcs.c field order in favor of the latter, which is better-aligned with the IndexStmt field order. This field is new in v14. Discussion: https://postgr.es/m/20210611045546.GA573364@rfd.leadboat.com
2021-06-10Reconsider the handling of procedure OUT parameters.Tom Lane
Commit 2453ea142 redefined pg_proc.proargtypes to include the types of OUT parameters, for procedures only. While that had some advantages for implementing the SQL-spec behavior of DROP PROCEDURE, it was pretty disastrous from a number of other perspectives. Notably, since the primary key of pg_proc is name + proargtypes, this made it possible to have multiple procedures with identical names + input arguments and differing output argument types. That would make it impossible to call any one of the procedures by writing just NULL (or "?", or any other data-type-free notation) for the output argument(s). The change also seems likely to cause grave confusion for client applications that examine pg_proc and expect the traditional definition of proargtypes. Hence, revert the definition of proargtypes to what it was, and undo a number of complications that had been added to support that. To support the SQL-spec behavior of DROP PROCEDURE, when there are no argmode markers in the command's parameter list, we perform the lookup both ways (that is, matching against both proargtypes and proallargtypes), succeeding if we get just one unique match. In principle this could result in ambiguous-function failures that would not happen when using only one of the two rules. However, overloading of procedure names is thought to be a pretty rare usage, so this shouldn't cause many problems in practice. Postgres-specific code such as pg_dump can defend against any possibility of such failures by being careful to specify argmodes for all procedure arguments. This also fixes a few other bugs in the area of CALL statements with named parameters, and improves the documentation a little. catversion bump forced because the representation of procedures with OUT arguments changes. Discussion: https://postgr.es/m/3742981.1621533210@sss.pgh.pa.us
2021-06-08Don't crash on empty statements in SQL-standard function bodies.Tom Lane
gram.y should discard NULL pointers (empty statements) when assembling a routine_body_stmt_list, as it does for other sorts of statement lists. Julien Rouhaud and Tom Lane, per report from Noah Misch. Discussion: https://postgr.es/m/20210606044418.GA297923@rfd.leadboat.com
2021-06-06Fix inconsistent equalfuncs.c behavior for FuncCall.funcformat.Tom Lane
Other equalfuncs.c checks on CoercionForm fields use COMPARE_COERCIONFORM_FIELD (which makes them no-ops), but commit 40c24bfef neglected to make _equalFuncCall do likewise. Fix that. This is only strictly correct if FuncCall.funcformat has no semantic effect, instead just determining ruleutils.c display formatting. 40c24bfef added a couple of checks in parse analysis that could break that rule; but on closer inspection, they're redundant, so just take them out again. Per report from Noah Misch. Discussion: https://postgr.es/m/20210606063331.GC297923@rfd.leadboat.com
2021-06-01Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.Tom Lane
This case should be disallowed, just as FOR UPDATE with a plain GROUP BY is disallowed; FOR UPDATE only makes sense when each row of the query result can be identified with a single table row. However, we missed teaching CheckSelectLocking() to check groupingSets as well as groupClause, so that it would allow degenerate grouping sets. That resulted in a bad plan and a null-pointer dereference in the executor. Looking around for other instances of the same bug, the only one I found was in examine_simple_variable(). That'd just lead to silly estimates, but it should be fixed too. Per private report from Yaoguang Chen. Back-patch to all supported branches.
2021-05-27Rethink definition of pg_attribute.attcompression.Tom Lane
Redefine '\0' (InvalidCompressionMethod) as meaning "if we need to compress, use the current setting of default_toast_compression". This allows '\0' to be a suitable default choice regardless of datatype, greatly simplifying code paths that initialize tupledescs and the like. It seems like a more user-friendly approach as well, because now the default compression choice doesn't migrate into table definitions, meaning that changing default_toast_compression is usually sufficient to flip an installation's behavior; one needn't tediously issue per-column ALTER SET COMPRESSION commands. Along the way, fix a few minor bugs and documentation issues with the per-column-compression feature. Adopt more robust APIs for SetIndexStorageProperties and GetAttributeCompression. Bump catversion because typical contents of attcompression will now be different. We could get away without doing that, but it seems better to ensure v14 installations all agree on this. (We already forced initdb for beta2, anyway.) Discussion: https://postgr.es/m/626613.1621787110@sss.pgh.pa.us
2021-05-15Allow compute_query_id to be set to 'auto' and make it defaultAlvaro Herrera
Allowing only on/off meant that all either all existing configuration guides would become obsolete if we disabled it by default, or that we would have to accept a performance loss in the default config if we enabled it by default. By allowing 'auto' as a middle ground, the performance cost is only paid by those who enable pg_stat_statements and similar modules. I only edited the release notes to comment-out a paragraph that is now factually wrong; further edits are probably needed to describe the related change in more detail. Author: Julien Rouhaud <rjuju123@gmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20210513002623.eugftm4nk2lvvks3@nol
2021-05-12Initial pgindent and pgperltidy run for v14.Tom Lane
Also "make reformat-dat-files". The only change worthy of note is that pgindent messed up the formatting of launcher.c's struct LogicalRepWorkerId, which led me to notice that that struct wasn't used at all anymore, so I just took it out.
2021-05-12Refactor some error messages for easier translationPeter Eisentraut
2021-05-11Fix typoPeter Eisentraut
2021-05-07Fix typos in comments about extended statisticsTomas Vondra
Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20210505210947.GA27406%40telsasoft.com
2021-05-07Revert per-index collation version tracking feature.Thomas Munro
Design problems were discovered in the handling of composite types and record types that would cause some relevant versions not to be recorded. Misgivings were also expressed about the use of the pg_depend catalog for this purpose. We're out of time for this release so we'll revert and try again. Commits reverted: 1bf946bd: Doc: Document known problem with Windows collation versions. cf002008: Remove no-longer-relevant test case. ef387bed: Fix bogus collation-version-recording logic. 0fb0a050: Hide internal error for pg_collation_actual_version(<bad OID>). ff942057: Suppress "warning: variable 'collcollate' set but not used". d50e3b1f: Fix assertion in collation version lookup. f24b1569: Rethink extraction of collation dependencies. 257836a7: Track collation versions for indexes. cd6f479e: Add pg_depend.refobjversion. 7d1297df: Remove pg_collation.collversion. Discussion: https://postgr.es/m/CA%2BhUKGLhj5t1fcjqAu8iD9B3ixJtsTNqyCCD4V0aTO9kAKAjjA%40mail.gmail.com
2021-05-06Remove redundant variableAlvaro Herrera
Author: Amul Sul <sulamul@gmail.com> Reviewed-by: Jeevan Ladhe <jeevan.ladhe@enterprisedb.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/CAAJ_b94HaNcrPVREUuB9-qUn2uB+gfcoX3FG_Vx0S6aFse+yhw@mail.gmail.com
2021-04-23Reorder COMPRESSION option in gram.y and parsenodes.h into alphabetical order.Fujii Masao
Commit bbe0a81db6 introduced "INCLUDING COMPRESSION" option in CREATE TABLE command, but previously TableLikeOption in gram.y and parsenodes.h didn't classify this new option in alphabetical order with the rest. Author: Fujii Masao Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/YHerAixOhfR1ryXa@paquier.xyz
2021-04-20adjust query id feature to use pg_stat_activity.query_idBruce Momjian
Previously, it was pg_stat_activity.queryid to match the pg_stat_statements queryid column. This is an adjustment to patch 4f0b0966c8. This also adjusts some of the internal function calls to match. Catversion bumped. Reported-by: Álvaro Herrera, Julien Rouhaud Discussion: https://postgr.es/m/20210408032704.GA7498@alvherre.pgsql
2021-04-13Allow table-qualified variable names in ON CONFLICT ... WHERE.Tom Lane
Previously you could only use unqualified variable names here. While that's not a functional deficiency, since only the target table can be referenced, it's a surprising inconsistency with the rules for partial-index predicates, on which this syntax is supposedly modeled. The fix for that is no harder than passing addToRelNameSpace = true to addNSItemToQuery. However, it's really pretty bogus for transformOnConflictArbiter and transformOnConflictClause to be messing with the namespace item for the target table at all. It's not theirs to manage, it results in duplicative creations of namespace items, and transformOnConflictClause wasn't even doing it quite correctly (that coding resulted in two nsitems for the target table, since it hadn't cleaned out the existing one). Hence, make transformInsertStmt responsible for setting up the target nsitem once for both these clauses and RETURNING. Also, arrange for ON CONFLICT ... UPDATE's "excluded" pseudo-relation to be added to the rangetable before we run transformOnConflictArbiter. This produces a more helpful HINT if someone writes "excluded.col" in the arbiter expression. Per bug #16958 from Lukas Eder. Although I agree this is a bug, the consequences are hardly severe, so no back-patch. Discussion: https://postgr.es/m/16958-963f638020de271c@postgresql.org