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* Expand comments and add an assertion in nodeModifyTable.c.Noah Misch2024-06-27
| | | | | | | | | | | Most comments concern RELKIND_VIEW. One addresses the ExecUpdate() "tupleid" parameter. A later commit will rely on these facts, but they hold already. Back-patch to v12 (all supported versions), the plan for that commit. Reviewed (in an earlier version) by Robert Haas. Discussion: https://postgr.es/m/20240512232923.aa.nmisch@google.com
* Fix behavior of stable functions called from a CALL's argument list.Tom Lane2024-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | If the CALL is within an atomic context (e.g. there's an outer transaction block), _SPI_execute_plan should acquire a fresh snapshot to execute any such functions with. We failed to do that and instead passed them the Portal snapshot, which had been acquired at the start of the current SQL command. This'd lead to seeing stale values of rows modified since the start of the command. This is arguably a bug in 84f5c2908: I failed to see that "are we in non-atomic mode" needs to be defined the same way as it is further down in _SPI_execute_plan, i.e. check !_SPI_current->atomic not just options->allow_nonatomic. Alternatively the blame could be laid on plpgsql, which is unconditionally passing allow_nonatomic = true for CALL/DO even when it knows it's in an atomic context. However, fixing it in spi.c seems like a better idea since that will also fix the problem for any extensions that may have copied plpgsql's coding pattern. While here, update an obsolete comment about _SPI_execute_plan's snapshot management. Per report from Victor Yegorov. Back-patch to all supported versions. Discussion: https://postgr.es/m/CAGnEboiRe+fG2QxuBO2390F7P8e2MQ6UyBjZSL_w1Cej+E4=Vw@mail.gmail.com
* Fix failure with SQL-procedure polymorphic output arguments in v12.Tom Lane2024-06-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Before the v13-era commit 913bbd88d, check_sql_fn_retval fails to resolve polymorphic output types and then just throws up its hands and assumes the check will be made at runtime. I think that's true for ordinary functions returning RECORD, but it doesn't happen in CALL, potentially resulting in crashes if the actual output of the SQL procedure's SELECT doesn't match the type inferred from polymorphism. With a little bit of rearrangement, we can use get_call_result_type instead of get_func_result_type and thereby infer the correct types. I'm still unwilling to back-patch all of 913bbd88d, so if the types don't match you'll get an error rather than perhaps silently inserting a cast as v13 and later can. That's consistent with prior behavior though, so it seems fine. Prior to 70ffb27b2, you'd typically get other errors due to other shortcomings of CALL's management of polymorphism. Nonetheless, this is an independent bug. Although there is no bug in v13 and up, it seems prudent to add the test case for this to the newer branches too. It's clearly an under-tested area. Per report from Andrew Bille. Discussion: https://postgr.es/m/CAJnzarw9EeWHAQRm76dXd=7j+rgw6ERqC=nCay8jeFqTwKwhqQ@mail.gmail.com
* Ensure we allocate NAMEDATALEN bytes for names in Index Only ScansDavid Rowley2024-05-01
| | | | | | | | | | | | | | | As an optimization, we store "name" columns as cstrings in btree indexes. Here we modify it so that Index Only Scans convert these cstrings back to names with NAMEDATALEN bytes rather than storing the cstring in the tuple slot, as was happening previously. Bug: #17855 Reported-by: Alexander Lakhin Reviewed-by: Alexander Lakhin, Tom Lane Discussion: https://postgr.es/m/17855-5f523e0f9769a566@postgresql.org Backpatch-through: 12, all supported versions
* Fix unnecessary use of moving-aggregate mode with non-moving frame.Tom Lane2024-03-27
| | | | | | | | | | | | | | | | | | | | When a plain aggregate is used as a window function, and the window frame start is specified as UNBOUNDED PRECEDING, the frame's head cannot move so we do not need to use moving-aggregate mode. The check for that was put into initialize_peragg(), failing to notice that ExecInitWindowAgg() calls that function before it's filled in winstate->frameOptions. Since makeNode() would have zeroed the field, this didn't provoke uninitialized-value complaints, nor would the erroneous decision have resulted in more than a little inefficiency. Still, it's wrong, so move the initialization of winstate->frameOptions earlier to make it work properly. While here, also fix a thinko in a comment. Both errors crept in in commit a9d9acbf2 which introduced the moving-aggregate mode. Spotted by Vallimaharajan G. Back-patch to all supported branches. Discussion: https://postgr.es/m/18e7f2a5167.fe36253866818.977923893562469143@zohocorp.com
* Fix EXPLAIN Bitmap heap scan to count pages with no visible tuplesHeikki Linnakangas2024-03-18
| | | | | | | | | | | | | | | | | Previously, bitmap heap scans only counted lossy and exact pages for explain when there was at least one visible tuple on the page. heapam_scan_bitmap_next_block() returned true only if there was a "valid" page with tuples to be processed. However, the lossy and exact page counters in EXPLAIN should count the number of pages represented in a lossy or non-lossy way in the constructed bitmap, regardless of whether or not the pages ultimately contained visible tuples. Backpatch to all supported versions. Author: Melanie Plageman Discussion: https://www.postgresql.org/message-id/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA@mail.gmail.com Discussion: https://www.postgresql.org/message-id/CAAKRu_bxrXeZ2rCnY8LyeC2Ls88KpjWrQ%2BopUrXDRXdcfwFZGA@mail.gmail.com
* Fix confusion about the return rowtype of SQL-language procedures.Tom Lane2024-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a very ancient hack in check_sql_fn_retval that allows a single SELECT targetlist entry of composite type to be taken as supplying all the output columns of a function returning composite. (This is grotty and fundamentally ambiguous, but it's really hard to do nested composite-returning functions without it.) As far as I know, that doesn't cause any problems in ordinary functions. It's disastrous for procedures however. All procedures that have any output parameters are labeled with prorettype RECORD, and the CALL code expects it will get back a record with one column per output parameter, regardless of whether any of those parameters is composite. Doing something else leads to an assertion failure or core dump. This is simple enough to fix: we just need to not apply that rule when considering procedures. However, that requires adding another argument to check_sql_fn_retval, which at least in principle might be getting called by external callers. Therefore, in the back branches convert check_sql_fn_retval into an ABI-preserving wrapper around a new function check_sql_fn_retval_ext. Per report from Yahor Yuzefovich. This has been broken since we implemented procedures, so back-patch to all supported branches. Discussion: https://postgr.es/m/CABz5gWHSjj2df6uG0NRiDhZ_Uz=Y8t0FJP-_SVSsRsnrQT76Gg@mail.gmail.com
* Fix type-checking of RECORD-returning functions in FROM.Tom Lane2024-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the corner case where a function returning RECORD has been simplified to a RECORD constant or an inlined ROW() expression, ExecInitFunctionScan failed to cross-check the function's result rowtype against the coldeflist provided by the calling query. That happened because get_expr_result_type is able to extract a tupdesc from such expressions, which led ExecInitFunctionScan to ignore the coldeflist. (Instead, it used the extracted tupdesc to check the function's output, which of course always succeeds.) I have not been able to demonstrate any really serious consequences from this, because if some column of the result is of the wrong type and is directly referenced by a Var of the calling query, CheckVarSlotCompatibility will catch it. However, we definitely do fail to report the case where the function returns more columns than the coldeflist expects, and in the converse case where it returns fewer columns, we get an assert failure (but, seemingly, no worse results in non-assert builds). To fix, always build the expected tupdesc from the coldeflist if there is one, and consult get_expr_result_type only when there isn't one. Also remove the failing Assert, even though it is no longer reached after this fix. It doesn't seem to be adding anything useful, since later checking will deal with cases with the wrong number of columns. The only other place I could find that is doing something similar is inline_set_returning_function. There's no live bug there because we cannot be looking at a Const or RowExpr, but for consistency change that code to agree with ExecInitFunctionScan. Per report from PetSerAl. After some debate I've concluded that this should be back-patched. There is a small risk that somebody has been relying on such a case not throwing an error, but I judge this outweighed by the risk that I've missed some way in which the failure to cross-check has worse consequences than sketched above. Discussion: https://postgr.es/m/CAKygsHSerA1eXsJHR9wft3Gn3wfHQ5RfP8XHBzF70_qcrrRvEg@mail.gmail.com
* Fix indentation in ExecParallelHashIncreaseNumBatches()Alexander Korotkov2024-01-08
| | | | Backpatch-through: 12
* Fix oversized memory allocation in Parallel Hash JoinAlexander Korotkov2024-01-07
| | | | | | | | | | | | During the calculations of the maximum for the number of buckets, take into account that later we round that to the next power of 2. Reported-by: Karen Talarico Bug: #16925 Discussion: https://postgr.es/m/16925-ec96d83529d0d629%40postgresql.org Author: Thomas Munro, Andrei Lepikhov, Alexander Korotkov Reviewed-by: Alena Rybakina Backpatch-through: 12
* Fix intra-query memory leak when a SRF returns zero rows.Tom Lane2023-10-28
| | | | | | | | | | | | | | | | | | When looping around after finding that the set-returning function returned zero rows for the current input tuple, ExecProjectSet neglected to reset either of the two memory contexts it's responsible for cleaning out. Typically this wouldn't cause much problem, because once the SRF does return at least one row, the contexts would get reset on the next call. However, if the SRF returns no rows for many input tuples in succession, quite a lot of memory could be transiently consumed. To fix, make sure we reset both contexts while looping around. Per bug #18172 from Sergei Kornilov. Back-patch to all supported branches. Discussion: https://postgr.es/m/18172-9b8c5fc1d676ded3@postgresql.org
* Fix runtime partition pruning for HASH partitioned tablesDavid Rowley2023-10-13
| | | | | | | | | | | | | | | | | | | | | | | This could only affect HASH partitioned tables with at least 2 partition key columns. If partition pruning was delayed until execution and the query contained an IS NULL qual on one of the partitioned keys, and some subsequent partitioned key was being compared to a non-Const, then this could result in a crash due to the incorrect keyno being used to calculate the stateidx for the expression evaluation code. Here we fix this by properly skipping partitioned keys which have a nullkey set. Effectively, this must be the same as what's going on inside perform_pruning_base_step(). Sergei Glukhov also provided a patch, but that's not what's being used here. Reported-by: Sergei Glukhov Reviewed-by: tender wang, Sergei Glukhov Discussion: https://postgr.es/m/d05b26fa-af54-27e1-f693-6c31590802fa@postgrespro.ru Backpatch-through: 11, where runtime partition pruning was added.
* Fix order of operations in ExecEvalFieldStoreDeForm().Tom Lane2023-06-29
| | | | | | | | | | | | | | | | | | | | | | | | | If the given composite datum is toasted out-of-line, DatumGetHeapTupleHeader will perform database accesses to detoast it. That can invalidate the result of get_cached_rowtype, as documented (perhaps not plainly enough) in that function's API spec; which leads to strange errors or crashes when we try to use the TupleDesc to read the tuple. In short then, trying to update a field of a composite column could fail intermittently if the overall column value is wide enough to require toasting. We can fix the bug at no cost by just changing the order of operations, since we don't need the TupleDesc until after detoasting. (Other callers of get_cached_rowtype appear to get this right already, so there's only one bug.) Note that the added regression test case reveals this bug reliably only with debug_discard_caches/CLOBBER_CACHE_ALWAYS. Per bug #17994 from Alexander Lakhin. Sadly, this patch does not fix the missing-values issue revealed in the bug discussion; we'll need some more work to cover that. Discussion: https://postgr.es/m/17994-5c7100b51b4790e9@postgresql.org
* Use per-tuple context in ExecGetAllUpdatedColsTomas Vondra2023-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit fc22b6623b (generated columns) replaced ExecGetUpdatedCols() with ExecGetAllUpdatedCols() in a couple places handling UPDATE (triggers and lock mode). However, ExecGetUpdatedCols() did exec_rt_fetch() while ExecGetAllUpdatedCols() also allocates memory through bms_union() without paying attention to the memory context and happened to use the long-lived ExecutorState, leaking the memory until the end of the query. The amount of leaked memory is proportional to the number of (updated) attributes, types of UPDATE triggers, and the number of processed rows (which for UPDATE ... FROM ... may be much higher than updated rows). Fixed by switching to the per-tuple context in GetAllUpdatedColumns(). This is fine for all in-core callers, but external callers may need to copy the result. But we're not aware of any such callers. Note the issue was introduced by fc22b6623b, but the macros were later renamed by f50e888990. Backpatch to 12, where the issue was introduced. Reported-by: Tomas Vondra Reviewed-by: Andres Freund, Tom Lane, Jakub Wartak Backpatch-through: 12 Discussion: https://postgr.es/m/222a3442-7f7d-246c-ed9b-a76209d19239@enterprisedb.com
* Fix assignment to array of domain over composite, redux.Tom Lane2023-04-15
| | | | | | | | | | | | | | | | Commit 3e310d837 taught isAssignmentIndirectionExpr() to look through CoerceToDomain nodes. That's not sufficient, because since commit 04fe805a1 it's been possible for the planner to simplify CoerceToDomain to RelabelType when the domain has no constraints to enforce. So we need to look through RelabelType too. Per bug #17897 from Alexander Lakhin. Although 3e310d837 was back-patched to v11, it seems sufficient to apply this change to v12 and later, since 04fe805a1 came in in v12. Dmitry Dolgov Discussion: https://postgr.es/m/17897-4216c546c3874044@postgresql.org
* Fix oversights in array manipulation.Tom Lane2023-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The nested-arrays code path in ExecEvalArrayExpr() used palloc to allocate the result array, whereas every other array-creating function has used palloc0 since 18c0b4ecc. This mostly works, but unused bits past the end of the nulls bitmap may end up undefined. That causes valgrind complaints with -DWRITE_READ_PARSE_PLAN_TREES, and could cause planner misbehavior as cited in 18c0b4ecc. There seems no very good reason why we should strive to avoid palloc0 in just this one case, so fix it the easy way with s/palloc/palloc0/. While looking at that I noted that we also failed to check for overflow of "nbytes" and "nitems" while summing the sizes of the sub-arrays, potentially allowing a crash due to undersized output allocation. For "nbytes", follow the policy used by other array-munging code of checking for overflow after each addition. (As elsewhere, the last addition of the array's overhead space doesn't need an extra check, since palloc itself will catch a value between 1Gb and 2Gb.) For "nitems", there's no very good reason to sum the inputs at all, since we can perfectly well use ArrayGetNItems' result instead of ignoring it. Per discussion of this bug, also remove redundant zeroing of the nulls bitmap in array_set_element and array_set_slice. Patch by Alexander Lakhin and myself, per bug #17858 from Alexander Lakhin; thanks also to Richard Guo. These bugs are a dozen years old, so back-patch to all supported branches. Discussion: https://postgr.es/m/17858-8fd287fd3663d051@postgresql.org
* Ignore generated columns during apply of update/delete.Amit Kapila2023-03-23
| | | | | | | | | | | | We fail to apply updates and deletes when the REPLICA IDENTITY FULL is used for the table having generated columns. We didn't use to ignore generated columns while doing tuple comparison among the tuples from the publisher and subscriber during apply of updates and deletes. Author: Onder Kalaci Reviewed-by: Shi yu, Amit Kapila Backpatch-through: 12 Discussion: https://postgr.es/m/CACawEhVQC9WoofunvXg12aXtbqKnEgWxoRx3+v8q32AWYsdpGg@mail.gmail.com
* Ignore dropped columns during apply of update/delete.Amit Kapila2023-03-21
| | | | | | | | | | | We fail to apply updates and deletes when the REPLICA IDENTITY FULL is used for the table having dropped columns. We didn't use to ignore dropped columns while doing tuple comparison among the tuples from the publisher and subscriber during apply of updates and deletes. Author: Onder Kalaci, Shi yu Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/CACawEhVQC9WoofunvXg12aXtbqKnEgWxoRx3+v8q32AWYsdpGg@mail.gmail.com
* Fix race in parallel hash join batch cleanup, take II.Thomas Munro2023-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With unlucky timing and parallel_leader_participation=off (not the default), PHJ could attempt to access per-batch shared state just as it was being freed. There was code intended to prevent that by checking for a cleared pointer, but it was racy. Fix, by introducing an extra barrier phase. The new phase PHJ_BUILD_RUNNING means that it's safe to access the per-batch state to find a batch to help with, and PHJ_BUILD_DONE means that it is too late. The last to detach will free the array of per-batch state as before, but now it will also atomically advance the phase, so that late attachers can avoid the hazard. This mirrors the way per-batch hash tables are freed (see phases PHJ_BATCH_PROBING and PHJ_BATCH_DONE). An earlier attempt to fix this (commit 3b8981b6, later reverted) missed one special case. When the inner side is empty (the "empty inner optimization), the build barrier would only make it to PHJ_BUILD_HASHING_INNER phase before workers attempted to detach from the hashtable. In that case, fast-forward the build barrier to PHJ_BUILD_RUNNING before proceeding, so that our later assertions hold and we can still negotiate who is cleaning up. Revealed by build farm failures, where BarrierAttach() failed a sanity check assertion, because the memory had been clobbered by dsa_free(). In non-assert builds, the result could be a segmentation fault. Back-patch to all supported releases. Author: Thomas Munro <thomas.munro@gmail.com> Author: Melanie Plageman <melanieplageman@gmail.com> Reported-by: Michael Paquier <michael@paquier.xyz> Reported-by: David Geier <geidav.pg@gmail.com> Tested-by: David Geier <geidav.pg@gmail.com> Discussion: https://postgr.es/m/20200929061142.GA29096%40paquier.xyz
* Fix some more cases of missed GENERATED-column updates.Tom Lane2023-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If UPDATE is forced to retry after an EvalPlanQual check, it neglected to repeat GENERATED-column computations, even though those might well have changed since we're dealing with a different tuple than before. Fixing this is mostly a matter of looping back a bit further when we retry. In v15 and HEAD that's most easily done by altering the API of ExecUpdateAct so that it includes computing GENERATED expressions. Also, if an UPDATE in a partitioned table turns into a cross-partition INSERT operation, we failed to recompute GENERATED columns. That's a bug since 8bf6ec3ba allowed partitions to have different generation expressions; although it seems to have no ill effects before that. Fixing this is messier because we can now have situations where the same query needs both the UPDATE-aligned set of GENERATED columns and the INSERT-aligned set, and it's unclear which set will be generated first (else we could hack things by forcing the INSERT-aligned set to be generated, which is indeed how fe9e658f4 made it work for MERGE). The best fix seems to be to build and store separate sets of expressions for the INSERT and UPDATE cases. That would create ABI issues in the back branches, but so far it seems we can leave this alone in the back branches. Per bug #17823 from Hisahiro Kauchi. The first part of this affects all branches back to v12 where GENERATED columns were added. Discussion: https://postgr.es/m/17823-b64909cf7d63de84@postgresql.org
* Fix MULTIEXPR_SUBLINK with partitioned target tables, yet again.Tom Lane2023-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We already tried to fix this in commits 3f7323cbb et al (and follow-on fixes), but now it emerges that there are still unfixed cases; moreover, these cases affect all branches not only pre-v14. I thought we had eliminated all cases of making multiple clones of an UPDATE's target list when we nuked inheritance_planner. But it turns out we still do that in some partitioned-UPDATE cases, notably including INSERT ... ON CONFLICT UPDATE, because ExecInitPartitionInfo thinks it's okay to clone and modify the parent's targetlist. This fix is based on a suggestion from Andres Freund: let's stop abusing the ParamExecData.execPlan mechanism, which was only ever meant to handle initplans, and instead solve the execution timing problem by having the expression compiler move MULTIEXPR_SUBLINK steps to the front of their expression step lists. This is feasible because (a) all branches still in support compile the entire targetlist of an UPDATE into a single ExprState, and (b) we know that all MULTIEXPR_SUBLINKs do need to be evaluated --- none could be buried inside a CASE, for example. There is a minor semantics change concerning the order of execution of the MULTIEXPR's subquery versus other parts of the parent targetlist, but that seems like something we can get away with. By doing that, we no longer need to worry about whether different clones of a MULTIEXPR_SUBLINK share output Params; their usage of that data structure won't overlap. Per bug #17800 from Alexander Lakhin. Back-patch to all supported branches. In v13 and earlier, we can revert 3f7323cbb and follow-on fixes; however, I chose to keep the SubPlan.subLinkId field added in ccbb54c72. We don't need that anymore in the core code, but it's cheap enough to fill, and removing a plan node field in a minor release seems like it'd be asking for trouble. Andres Freund and Tom Lane Discussion: https://postgr.es/m/17800-ff90866b3906c964@postgresql.org
* Add missing support for the latest SPI status codes.Dean Rasheed2023-02-22
| | | | | | | | | | | | | | | | | | | SPI_result_code_string() was missing support for SPI_OK_TD_REGISTER, and in v15 and later, it was missing support for SPI_OK_MERGE, as was pltcl_process_SPI_result(). The last of those would trigger an error if a MERGE was executed from PL/Tcl. The others seem fairly innocuous, but worth fixing. Back-patch to all supported branches. Before v15, this is just adding SPI_OK_TD_REGISTER to SPI_result_code_string(), which is unlikely to be seen by anyone, but seems worth doing for completeness. Reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCUg8V%2BK%2BGcafOPqymxk84Y_prXgfe64PDoopjLFH6Z0Aw%40mail.gmail.com https://postgr.es/m/CAEZATCUMe%2B_KedPMM9AxKqm%3DSZogSxjUcrMe%2BsakusZh3BFcQw%40mail.gmail.com
* Disable WindowAgg inverse transitions when subplans are presentDavid Rowley2023-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | When an aggregate function is used as a WindowFunc and a tuple transitions out of the window frame, we ordinarily try to make use of the aggregate function's inverse transition function to "unaggregate" the exiting tuple. This optimization is disabled for various cases, including when the aggregate contains a volatile function. In such a case we'd be unable to ensure that the transition value was calculated to the same value during transitions and inverse transitions. Unfortunately, we did this check by calling contain_volatile_functions() which does not recursively search SubPlans for volatile functions. If the aggregate function's arguments or its FILTER clause contained a subplan with volatile functions then we'd fail to notice this. Here we fix this by just disabling the optimization when the WindowFunc contains any subplans. Volatile functions are not the only reason that a subplan may have nonrepeatable results. Bug: #17777 Reported-by: Anban Company Discussion: https://postgr.es/m/17777-860b739b6efde977%40postgresql.org Reviewed-by: Tom Lane Backpatch-through: 11
* Avoid reference to nonexistent array element in ExecInitAgg().Tom Lane2023-01-02
| | | | | | | | | | | | | | | | When considering an empty grouping set, we fetched phasedata->eqfunctions[-1]. Because the eqfunctions array is palloc'd, that would always be an aset pointer in released versions, and thus the code accidentally failed to malfunction (since it would do nothing unless it found a null pointer). Nonetheless this seems like trouble waiting to happen, so add a check for length == 0. It's depressing that our valgrind testing did not catch this. Maybe we should reconsider the choice to not mark that word NOACCESS? Richard Guo Discussion: https://postgr.es/m/CAMbWs4-vZuuPOZsKOYnSAaPYGKhmacxhki+vpOKk0O7rymccXQ@mail.gmail.com
* Fix copy-and-pasteo in comment.Etsuro Fujita2022-11-02
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* Future-proof the recursion inside ExecShutdownNode().Tom Lane2022-09-19
| | | | | | | | | | | | | | | | | | | | | | | The API contract for planstate_tree_walker() callbacks is that they take a PlanState pointer and a context pointer. Somebody figured they could save a couple lines of code by ignoring that, and passing ExecShutdownNode itself as the walker even though it has but one argument. Somewhat remarkably, we've gotten away with that so far. However, it seems clear that the upcoming C2x standard means to forbid such cases, and compilers that actively break such code likely won't be far behind. So spend the extra few lines of code to do it honestly with a separate walker function. In HEAD, we might as well go further and remove ExecShutdownNode's useless return value. I left that as-is in back branches though, to forestall complaints about ABI breakage. Back-patch, with the thought that this might become of practical importance before our stable branches are all out of service. It doesn't seem to be fixing any live bug on any currently known platform, however. Discussion: https://postgr.es/m/208054.1663534665@sss.pgh.pa.us
* Repair rare failure of MULTIEXPR_SUBLINK subplans in inherited updates.Tom Lane2022-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to v14, if we have a MULTIEXPR SubPlan (that is, use of the syntax UPDATE ... SET (c1, ...) = (SELECT ...)) in an UPDATE with an inherited or partitioned target table, inheritance_planner() will clone the targetlist and therefore also the MULTIEXPR SubPlan and the Param nodes referencing it for each child target table. Up to now, we've allowed all the clones to share the underlying subplan as well as the output parameter IDs -- that is, the runtime ParamExecData slots. That technique is borrowed from the far older code that supports initplans, and it works okay in that case because the cloned SubPlan nodes are essentially identical. So it doesn't matter which one of the clones the shared ParamExecData.execPlan field might point to. However, this fails to hold for MULTIEXPR SubPlans, because they can have nonempty "args" lists (values to be passed into the subplan), and those lists could get mutated to different states in the various clones. In the submitted reproducer, as well as the test case added here, one clone contains Vars with varno OUTER_VAR where another has INNER_VAR, because the child tables are respectively on the outer or inner side of the join. Sharing the execPlan pointer can result in trying to evaluate an args list that doesn't match the local execution state, with mayhem ensuing. The result often is to trigger consistency checks in the executor, but I believe this could end in a crash or incorrect updates. To fix, assign new Param IDs to each of the cloned SubPlans, so that they don't share ParamExecData slots at runtime. It still seems fine for the clones to share the underlying subplan, and extra ParamExecData slots are cheap enough that this fix shouldn't cost much. This has been busted since we invented MULTIEXPR SubPlans in 9.5. Probably the lack of previous reports is because query plans in which the different clones of a MULTIEXPR mutate to effectively-different states are pretty rare. There's no issue in v14 and later, because without inheritance_planner() there's never a reason to clone MULTIEXPR SubPlans. Per bug #17596 from Andre Lin. Patch v10-v13 only. Discussion: https://postgr.es/m/17596-c5357f61427a81dc@postgresql.org
* Fix handling of R/W expanded datums that are passed to SQL functions.Tom Lane2022-08-10
| | | | | | | | | | | | | | | | | | | fmgr_sql must make expanded-datum arguments read-only, because it's possible that the function body will pass the argument to more than one callee function. If one of those functions takes the datum's R/W property as license to scribble on it, then later callees will see an unexpected value, leading to wrong answers. From a performance standpoint, it'd be nice to skip this in the common case that the argument value is passed to only one callee. However, detecting that seems fairly hard, and certainly not something that I care to attempt in a back-patched bug fix. Per report from Adam Mackler. This has been broken since we invented expanded datums, so back-patch to all supported branches. Discussion: https://postgr.es/m/WScDU5qfoZ7PB2gXwNqwGGgDPmWzz08VdydcPFLhOwUKZcdWbblbo-0Lku-qhuEiZoXJ82jpiQU4hOjOcrevYEDeoAvz6nR0IU4IHhXnaCA=@mackler.email Discussion: https://postgr.es/m/187436.1660143060@sss.pgh.pa.us
* Add CHECK_FOR_INTERRUPTS in ExecInsert's speculative insertion loop.Tom Lane2022-08-04
| | | | | | | | | | | | | Ordinarily the functions called in this loop ought to have plenty of CFIs themselves; but we've now seen a case where no such CFI is reached, making the loop uninterruptible. Even though that's from a recently-introduced bug, it seems prudent to install a CFI at the loop level in all branches. Per discussion of bug #17558 from Andrew Kesper (an actual fix for that bug will follow). Discussion: https://postgr.es/m/17558-3f6599ffcf52fd4a@postgresql.org
* Re-add SPICleanup for ABI compatibility in stable branchPeter Eisentraut2022-07-18
| | | | | | | | This fixes an ABI break introduced by 293f5c5f496cd8ce87c65b393613da675fc0bb8d. Author: Markus Wanner <markus.wanner@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/defd749a-8410-841d-1126-21398686d63d@enterprisedb.com
* Fix SPI's handling of errors during transaction commit.Tom Lane2022-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SPI_commit previously left it up to the caller to recover from any error occurring during commit. Since that's complicated and requires use of low-level xact.c facilities, it's not too surprising that no caller got it right. Let's move the responsibility for cleanup into spi.c. Doing that requires redefining SPI_commit as starting a new transaction, so that it becomes equivalent to SPI_commit_and_chain except that you get default transaction characteristics instead of preserving the prior transaction's characteristics. We can make this pretty transparent API-wise by redefining SPI_start_transaction() as a no-op. Callers that expect to do something in between might be surprised, but available evidence is that no callers do so. Having made that API redefinition, we can fix this mess by having SPI_commit[_and_chain] trap errors and start a new, clean transaction before re-throwing the error. Likewise for SPI_rollback[_and_chain]. Some cleanup is also needed in AtEOXact_SPI, which was nowhere near smart enough to deal with SPI contexts nested inside a committing context. While plperl and pltcl need no changes beyond removing their now-useless SPI_start_transaction() calls, plpython needs some more work because it hadn't gotten the memo about catching commit/rollback errors in the first place. Such an error resulted in longjmp'ing out of the Python interpreter, which leaks Python stack entries at present and is reported to crash Python 3.11 altogether. Add the missing logic to catch such errors and convert them into Python exceptions. This is a back-patch of commit 2e517818f. That's now aged long enough to reduce the concerns about whether it will break something, and we do need to ensure that supported branches will work with Python 3.11. Peter Eisentraut and Tom Lane Discussion: https://postgr.es/m/3375ffd8-d71c-2565-e348-a597d6e739e3@enterprisedb.com Discussion: https://postgr.es/m/17416-ed8fe5d7213d6c25@postgresql.org
* Un-break whole-row Vars referencing domain-over-composite types.Tom Lane2022-06-10
| | | | | | | | | | | | | | | | | In commit ec62cb0aa, I foolishly replaced ExecEvalWholeRowVar's lookup_rowtype_tupdesc_domain call with just lookup_rowtype_tupdesc, because I didn't see how a domain could be involved there, and there were no regression test cases to jog my memory. But the existing code was correct, so revert that change and add a test case showing why it's necessary. (Note: per comment in struct DatumTupleFields, it is correct to produce an output tuple that's labeled with the base composite type, not the domain; hence just blindly looking through the domain is correct here.) Per bug #17515 from Dan Kubb. Back-patch to v11 where domains over composites became a thing. Discussion: https://postgr.es/m/17515-a24737438363aca0@postgresql.org
* Revert applying column aliases to the output of whole-row Vars.Tom Lane2022-03-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit bf7ca1587, I had the bright idea that we could make the result of a whole-row Var (that is, foo.*) track any column aliases that had been applied to the FROM entry the Var refers to. However, that's not terribly logically consistent, because now the output of the Var is no longer of the named composite type that the Var claims to emit. bf7ca1587 tried to handle that by changing the output tuple values to be labeled with a blessed RECORD type, but that's really pretty disastrous: we can wind up storing such tuples onto disk, whereupon they're not readable by other sessions. The only practical fix I can see is to give up on what bf7ca1587 tried to do, and say that the column names of tuples produced by a whole-row Var are always those of the underlying named composite type, query aliases or no. While this introduces some inconsistencies, it removes others, so it's not that awful in the abstract. What *is* kind of awful is to make such a behavioral change in a back-patched bug fix. But corrupt data is worse, so back-patched it will be. (A workaround available to anyone who's unhappy about this is to introduce an extra level of sub-SELECT, so that the whole-row Var is referring to the sub-SELECT's output and not to a named table type. Then the Var is of type RECORD to begin with and there's no issue.) Per report from Miles Delahunty. The faulty commit dates to 9.5, so back-patch to all supported branches. Discussion: https://postgr.es/m/2950001.1638729947@sss.pgh.pa.us
* Fix memory leak in IndexScan node with reorderingAlexander Korotkov2022-02-14
| | | | | | | | | | Fix ExecReScanIndexScan() to free the referenced tuples while emptying the priority queue. Backpatch to all supported versions. Discussion: https://postgr.es/m/CAHqSB9gECMENBQmpbv5rvmT3HTaORmMK3Ukg73DsX5H7EJV7jw%40mail.gmail.com Author: Aliaksandr Kalenik Reviewed-by: Tom Lane, Alexander Korotkov Backpatch-through: 10
* Test, don't just Assert, that mergejoin's inputs are in order.Tom Lane2022-02-05
| | | | | | | | | | | | | | | | | There are two Asserts in nodeMergejoin.c that are reachable if the input data is not in the expected order. This seems way too fragile. Alexander Lakhin reported a case where the assertions could be triggered with misconfigured foreign-table partitions, and bitter experience with unstable operating system collation definitions suggests another easy route to hitting them. Neither Assert is in a place where we can't afford one more test-and-branch, so replace 'em with plain test-and-elog logic. Per bug #17395. While the reported symptom is relatively recent, collation changes could happen anytime, so back-patch to all supported branches. Discussion: https://postgr.es/m/17395-8c326292078d1a57@postgresql.org
* Fix index-only scan plans, take 2.Tom Lane2022-01-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4ace45677 failed to fix the problem fully, because the same issue of attempting to fetch a non-returnable index column can occur when rechecking the indexqual after using a lossy index operator. Moreover, it broke EXPLAIN for such indexquals (which indicates a gap in our test cases :-(). Revert the code changes of 4ace45677 in favor of adding a new field to struct IndexOnlyScan, containing a version of the indexqual that can be executed against the index-returned tuple without using any non-returnable columns. (The restrictions imposed by check_index_only guarantee this is possible, although we may have to recompute indexed expressions.) Support construction of that during setrefs.c processing by marking IndexOnlyScan.indextlist entries as resjunk if they can't be returned, rather than removing them entirely. (We could alternatively require setrefs.c to look up the IndexOptInfo again, but abusing resjunk this way seems like a reasonably safe way to avoid needing to do that.) This solution isn't great from an API-stability standpoint: if there are any extensions out there that build IndexOnlyScan structs directly, they'll be broken in the next minor releases. However, only a very invasive extension would be likely to do such a thing. There's no change in the Path representation, so typical planner extensions shouldn't have a problem. As before, back-patch to all supported branches. Discussion: https://postgr.es/m/3179992.1641150853@sss.pgh.pa.us Discussion: https://postgr.es/m/17350-b5bdcf476e5badbb@postgresql.org
* Fix assignment to array of domain over composite.Tom Lane2021-10-19
| | | | | | | | | | | | | | | An update such as "UPDATE ... SET fld[n].subfld = whatever" failed if the array elements were domains rather than plain composites. That's because isAssignmentIndirectionExpr() failed to cope with the CoerceToDomain node that would appear in the expression tree in this case. The result would typically be a crash, and even if we accidentally didn't crash, we'd not correctly preserve other fields of the same array element. Per report from Onder Kalaci. Back-patch to v11 where arrays of domains came in. Discussion: https://postgr.es/m/PH0PR21MB132823A46AA36F0685B7A29AD8BD9@PH0PR21MB1328.namprd21.prod.outlook.com
* Fix usage of "tableoid" in GENERATED expressions.Tom Lane2021-05-21
| | | | | | | | | | | | | | | We consider this supported (though I've got my doubts that it's a good idea, because tableoid is not immutable). However, several code paths failed to fill the field in soon enough, causing such a GENERATED expression to see zero or the wrong value. This occurred when ALTER TABLE adds a new GENERATED column to a table with existing rows, and during regular INSERT or UPDATE on a foreign table with GENERATED columns. Noted during investigation of a report from Vitaly Ustinov. Back-patch to v12 where GENERATED came in. Discussion: https://postgr.es/m/CAM_DEiWR2DPT6U4xb-Ehigozzd3n3G37ZB1+867zbsEVtYoJww@mail.gmail.com
* Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.Tom Lane2021-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | COMMIT/ROLLBACK necessarily destroys all snapshots within the session. The original implementation of intra-procedure transactions just cavalierly did that, ignoring the fact that this left us executing in a rather different environment than normal. In particular, it turns out that handling of toasted datums depends rather critically on there being an outer ActiveSnapshot: otherwise, when SPI or the core executor pop whatever snapshot they used and return, it's unsafe to dereference any toasted datums that may appear in the query result. It's possible to demonstrate "no known snapshots" and "missing chunk number N for toast value" errors as a result of this oversight. Historically this outer snapshot has been held by the Portal code, and that seems like a good plan to preserve. So add infrastructure to pquery.c to allow re-establishing the Portal-owned snapshot if it's not there anymore, and add enough bookkeeping support that we can tell whether it is or not. We can't, however, just re-establish the Portal snapshot as part of COMMIT/ROLLBACK. As in normal transaction start, acquiring the first snapshot should wait until after SET and LOCK commands. Hence, teach spi.c about doing this at the right time. (Note that this patch doesn't fix the problem for any PLs that try to run intra-procedure transactions without using SPI to execute SQL commands.) This makes SPI's no_snapshots parameter rather a misnomer, so in HEAD, rename that to allow_nonatomic. replication/logical/worker.c also needs some fixes, because it wasn't careful to hold a snapshot open around AFTER trigger execution. That code doesn't use a Portal, which I suspect someday we're gonna have to fix. But for now, just rearrange the order of operations. This includes back-patching the recent addition of finish_estate() to centralize the cleanup logic there. This also back-patches commit 2ecfeda3e into v13, to improve the test coverage for worker.c (it was that test that exposed that worker.c's snapshot management is wrong). Per bug #15990 from Andreas Wicht. Back-patch to v11 where intra-procedure COMMIT was added. Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
* Fix mishandling of resjunk columns in ON CONFLICT ... UPDATE tlists.Tom Lane2021-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's unusual to have any resjunk columns in an ON CONFLICT ... UPDATE list, but it can happen when MULTIEXPR_SUBLINK SubPlans are present. If it happens, the ON CONFLICT UPDATE code path would end up storing tuples that include the values of the extra resjunk columns. That's fairly harmless in the short run, but if new columns are added to the table then the values would become accessible, possibly leading to malfunctions if they don't match the datatypes of the new columns. This had escaped notice through a confluence of missing sanity checks, including * There's no cross-check that a tuple presented to heap_insert or heap_update matches the table rowtype. While it's difficult to check that fully at reasonable cost, we can easily add assertions that there aren't too many columns. * The output-column-assignment cases in execExprInterp.c lacked any sanity checks on the output column numbers, which seems like an oversight considering there are plenty of assertion checks on input column numbers. Add assertions there too. * We failed to apply nodeModifyTable's ExecCheckPlanOutput() to the ON CONFLICT UPDATE tlist. That wouldn't have caught this specific error, since that function is chartered to ignore resjunk columns; but it sure seems like a bad omission now that we've seen this bug. In HEAD, the right way to fix this is to make the processing of ON CONFLICT UPDATE tlists work the same as regular UPDATE tlists now do, that is don't add "SET x = x" entries, and use ExecBuildUpdateProjection to evaluate the tlist and combine it with old values of the not-set columns. This adds a little complication to ExecBuildUpdateProjection, but allows removal of a comparable amount of now-dead code from the planner. In the back branches, the most expedient solution seems to be to (a) use an output slot for the ON CONFLICT UPDATE projection that actually matches the target table, and then (b) invent a variant of ExecBuildProjectionInfo that can be told to not store values resulting from resjunk columns, so it doesn't try to store into nonexistent columns of the output slot. (We can't simply ignore the resjunk columns altogether; they have to be evaluated for MULTIEXPR_SUBLINK to work.) This works back to v10. In 9.6, projections work much differently and we can't cheaply give them such an option. The 9.6 version of this patch works by inserting a JunkFilter when it's necessary to get rid of resjunk columns. In addition, v11 and up have the reverse problem when trying to perform ON CONFLICT UPDATE on a partitioned table. Through a further oversight, adjust_partition_tlist() discarded resjunk columns when re-ordering the ON CONFLICT UPDATE tlist to match a partition. This accidentally prevented the storing-bogus-tuples problem, but at the cost that MULTIEXPR_SUBLINK cases didn't work, typically crashing if more than one row has to be updated. Fix by preserving resjunk columns in that routine. (I failed to resist the temptation to add more assertions there too, and to do some minor code beautification.) Per report from Andres Freund. Back-patch to all supported branches. Security: CVE-2021-32028
* Prevent integer overflows in array subscripting calculations.Tom Lane2021-05-10
| | | | | | | | | | | | | | | | | | | | | | | | While we were (mostly) careful about ensuring that the dimensions of arrays aren't large enough to cause integer overflow, the lower bound values were generally not checked. This allows situations where lower_bound + dimension overflows an integer. It seems that that's harmless so far as array reading is concerned, except that array elements with subscripts notionally exceeding INT_MAX are inaccessible. However, it confuses various array-assignment logic, resulting in a potential for memory stomps. Fix by adding checks that array lower bounds aren't large enough to cause lower_bound + dimension to overflow. (Note: this results in disallowing cases where the last subscript position would be exactly INT_MAX. In principle we could probably allow that, but there's a lot of code that computes lower_bound + dimension and would need adjustment. It seems doubtful that it's worth the trouble/risk to allow it.) Somewhat independently of that, array_set_element() was careless about possible overflow when checking the subscript of a fixed-length array, creating a different route to memory stomps. Fix that too. Security: CVE-2021-32027
* Don't crash on reference to an un-available system column.Tom Lane2021-04-22
| | | | | | | | | | | | | | | | Adopt a more consistent policy about what slot-type-specific getsysattr functions should do when system attributes are not available. To wit, they should all throw the same user-oriented error, rather than variously crashing or emitting developer-oriented messages. This closes a identifiable problem in commits a71cfc56b and 3fb93103a (in v13 and v12), so back-patch into those branches, along with a test case to try to ensure we don't break it again. It is not known that any of the former crash cases are reachable in HEAD, but this seems like a good safety improvement in any case. Discussion: https://postgr.es/m/141051591267657@mail.yandex.ru
* Fix bugs in RETURNING in cross-partition UPDATE cases.Tom Lane2021-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the source and destination partitions don't have identical rowtypes (for example, one has dropped columns the other lacks), then the planSlot contents will be different because of that. If the query has a RETURNING list that tries to return resjunk columns out of the planSlot, that is columns from tables that were joined to the target table, we'd get errors or wrong answers. That's because we used the RETURNING list generated for the destination partition, which expects a planSlot matching that partition's subplan. The most practical fix seems to be to convert the updated destination tuple back to the source partition's rowtype, and then apply the RETURNING list generated for the source partition. This avoids making fragile assumptions about whether the per-subpartition subplans generated all the resjunk columns in the same order. This has been broken since v11 introduced cross-partition UPDATE. The lack of field complaints shows that non-identical partitions aren't a common case; therefore, don't stress too hard about making the conversion efficient. There's no such bug in HEAD, because commit 86dc90056 got rid of per-target-relation variance in the contents of the planSlot. Hence, patch v11-v13 only. Amit Langote and Etsuro Fujita, small changes by me Discussion: https://postgr.es/m/CA+HiwqE_UK1jTSNrjb8mpTdivzd3dum6mK--xqKq0Y9VmfwWQA@mail.gmail.com
* Redesign the caching done by get_cached_rowtype().Tom Lane2021-04-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, get_cached_rowtype() cached a pointer to a reference-counted tuple descriptor from the typcache, relying on the ExprContextCallback mechanism to release the tupdesc refcount when the expression tree using the tupdesc was destroyed. This worked fine when it was designed, but the introduction of within-DO-block COMMITs broke it. The refcount is logged in a transaction-lifespan resource owner, but plpgsql won't destroy simple expressions made within the DO block (before its first commit) until the DO block is exited. That results in a warning about a leaked tupdesc refcount when the COMMIT destroys the original resource owner, and then an error about the active resource owner not holding a matching refcount when the expression is destroyed. To fix, get rid of the need to have a shutdown callback at all, by instead caching a pointer to the relevant typcache entry. Those survive for the life of the backend, so we needn't worry about the pointer becoming stale. (For registered RECORD types, we can still cache a pointer to the tupdesc, knowing that it won't change for the life of the backend.) This mechanism has been in use in plpgsql and expandedrecord.c since commit 4b93f5799, and seems to work well. This change requires modifying the ExprEvalStep structs used by the relevant expression step types, which is slightly worrisome for back-patching. However, there seems no good reason for extensions to be familiar with the details of these particular sub-structs. Per report from Rohit Bhogate. Back-patch to v11 where within-DO-block COMMITs became a thing. Discussion: https://postgr.es/m/CAAV6ZkQRCVBh8qAY+SZiHnz+U+FqAGBBDaDTjF2yiKa2nJSLKg@mail.gmail.com
* Revert "Fix race in Parallel Hash Join batch cleanup."Thomas Munro2021-03-18
| | | | | | This reverts commit 8fa2478b407ef867d501fafcdea45fd827f70799. Discussion: https://postgr.es/m/CA%2BhUKGJmcqAE3MZeDCLLXa62cWM0AJbKmp2JrJYaJ86bz36LFA%40mail.gmail.com
* Fix race in Parallel Hash Join batch cleanup.Thomas Munro2021-03-17
| | | | | | | | | | | | | | | | | | | | | | | | | With very unlucky timing and parallel_leader_participation off, PHJ could attempt to access per-batch state just as it was being freed. There was code intended to prevent that by checking for a cleared pointer, but it was buggy. Fix, by introducing an extra barrier phase. The new phase PHJ_BUILD_RUNNING means that it's safe to access the per-batch state to find a batch to help with, and PHJ_BUILD_DONE means that it is too late. The last to detach will free the array of per-batch state as before, but now it will also atomically advance the phase at the same time, so that late attachers can avoid the hazard, without the data race. This mirrors the way per-batch hash tables are freed (see phases PHJ_BATCH_PROBING and PHJ_BATCH_DONE). Revealed by a one-off build farm failure, where BarrierAttach() failed a sanity check assertion, because the memory had been clobbered by dsa_free(). Back-patch to 11, where the code arrived. Reported-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/20200929061142.GA29096%40paquier.xyz
* Make ExecGetInsertedCols() and friends more robust and improve comments.Heikki Linnakangas2021-02-15
| | | | | | | | | | | | | | | | | | If ExecGetInsertedCols(), ExecGetUpdatedCols() or ExecGetExtraUpdatedCols() were called with a ResultRelInfo that's not in the range table and isn't a partition routing target, the functions would dereference a NULL pointer, relinfo->ri_RootResultRelInfo. Such ResultRelInfos are created when firing RI triggers in tables that are not modified directly. None of the current callers of these functions pass such relations, so this isn't a live bug, but let's make them more robust. Also update comment in ResultRelInfo; after commit 6214e2b228, ri_RangeTableIndex is zero for ResultRelInfos created for partition tuple routing. Noted by Coverity. Backpatch down to v11, like commit 6214e2b228. Reviewed-by: Tom Lane, Amit Langote
* Fix permission checks on constraint violation errors on partitions.Heikki Linnakangas2021-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a cross-partition UPDATE violates a constraint on the target partition, and the columns in the new partition are in different physical order than in the parent, the error message can reveal columns that the user does not have SELECT permission on. A similar bug was fixed earlier in commit 804b6b6db4. The cause of the bug is that the callers of the ExecBuildSlotValueDescription() function got confused when constructing the list of modified columns. If the tuple was routed from a parent, we converted the tuple to the parent's format, but the list of modified columns was grabbed directly from the child's RTE entry. ExecUpdateLockMode() had a similar issue. That lead to confusion on which columns are key columns, leading to wrong tuple lock being taken on tables referenced by foreign keys, when a row is updated with INSERT ON CONFLICT UPDATE. A new isolation test is added for that corner case. With this patch, the ri_RangeTableIndex field is no longer set for partitions that don't have an entry in the range table. Previously, it was set to the RTE entry of the parent relation, but that was confusing. NOTE: This modifies the ResultRelInfo struct, replacing the ri_PartitionRoot field with ri_RootResultRelInfo. That's a bit risky to backpatch, because it breaks any extensions accessing the field. The change that ri_RangeTableIndex is not set for partitions could potentially break extensions, too. The ResultRelInfos are visible to FDWs at least, and this patch required small changes to postgres_fdw. Nevertheless, this seem like the least bad option. I don't think these fields widely used in extensions; I don't think there are FDWs out there that uses the FDW "direct update" API, other than postgres_fdw. If there is, you will get a compilation error, so hopefully it is caught quickly. Backpatch to 11, where support for both cross-partition UPDATEs, and unique indexes on partitioned tables, were added. Reviewed-by: Amit Langote Security: CVE-2021-3393
* Fix hash partition pruning with asymmetric partition sets.Tom Lane2021-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perform_pruning_combine_step() was not taught about the number of partition indexes used in hash partitioning; more embarrassingly, get_matching_hash_bounds() also had it wrong. These errors are masked in the common case where all the partitions have the same modulus and no partition is missing. However, with missing or unequal-size partitions, we could erroneously prune some partitions that need to be scanned, leading to silently wrong query answers. While a minimal-footprint fix for this could be to export get_partition_bound_num_indexes and make the incorrect functions use it, I'm of the opinion that that function should never have existed in the first place. It's not reasonable data structure design that PartitionBoundInfoData lacks any explicit record of the length of its indexes[] array. Perhaps that was all right when it could always be assumed equal to ndatums, but something should have been done about it as soon as that stopped being true. Putting in an explicit "nindexes" field makes both partition_bounds_equal() and partition_bounds_copy() simpler, safer, and faster than before, and removes explicit knowledge of the number-of-partition-indexes rules from some other places too. This change also makes get_hash_partition_greatest_modulus obsolete. I left that in place in case any external code uses it, but no core code does anymore. Per bug #16840 from MichaƂ Albrycht. Back-patch to v11 where the hash partitioning code came in. (In the back branches, add the new field at the end of PartitionBoundInfoData to minimize ABI risks.) Discussion: https://postgr.es/m/16840-571a22976f829ad4@postgresql.org
* Don't add bailout adjustment for non-strict deserialize calls.Andrew Gierth2021-01-28
| | | | | | | | | | | | | | | | | | | | When building aggregate expression steps, strict checks need a bailout jump for when a null value is encountered, so there is a list of steps that require later adjustment. Adding entries to that list for steps that aren't actually strict would be harmless, except that there is an Assert which catches them. This leads to spurious errors on asserts builds, for data sets that trigger parallel aggregation of an aggregate with a non-strict deserialization function (no such aggregates exist in the core system). Repair by not adding the adjustment entry when it's not needed. Backpatch back to 11 where the code was introduced. Per a report from Darafei (Komzpa) of the PostGIS project; analysis and patch by me. Discussion: https://postgr.es/m/87mty7peb3.fsf@news-spur.riddles.org.uk