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path: root/src/backend/executor/nodeModifyTable.c
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* For inplace update durability, make heap_update() callers wait.Noah Misch2024-09-24
| | | | | | | | | | | | | | | | | | | The previous commit fixed some ways of losing an inplace update. It remained possible to lose one when a backend working toward a heap_update() copied a tuple into memory just before inplace update of that tuple. In catalogs eligible for inplace update, use LOCKTAG_TUPLE to govern admission to the steps of copying an old tuple, modifying it, and issuing heap_update(). This includes MERGE commands. To avoid changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when holding a relation lock sufficient to exclude inplace updaters. Back-patch to v12 (all supported versions). In v13 and v12, "UPDATE pg_class" or "UPDATE pg_database" can still lose an inplace update. The v14+ UPDATE fix needs commit 86dc90056dfdbd9d1b891718d2e5614e3e432f35, and it wasn't worth reimplementing that fix without such infrastructure. Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas. Discussion: https://postgr.es/m/20231027214946.79.nmisch@google.com
* 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 problems when a plain-inheritance parent table is excluded.Tom Lane2023-10-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an UPDATE/DELETE/MERGE's target table is an old-style inheritance tree, it's possible for the parent to get excluded from the plan while some children are not. (I believe this is only possible if we can prove that a CHECK ... NO INHERIT constraint on the parent contradicts the query WHERE clause, so it's a very unusual case.) In such a case, ExecInitModifyTable mistakenly concluded that the first surviving child is the target table, leading to at least two bugs: 1. The wrong table's statement-level triggers would get fired. 2. In v16 and up, it was possible to fail with "invalid perminfoindex 0 in RTE with relid nnnn" due to the child RTE not having permissions data included in the query plan. This was hard to reproduce reliably because it did not occur unless the update triggered some non-HOT index updates. In v14 and up, this is easy to fix by defining ModifyTable.rootRelation to be the parent RTE in plain inheritance as well as partitioned cases. While the wrong-triggers bug also appears in older branches, the relevant code in both the planner and executor is quite a bit different, so it would take a good deal of effort to develop and test a suitable patch. Given the lack of field complaints about the trigger issue, I'll desist for now. (Patching v11 for this seems unwise anyway, given that it will have no more releases after next month.) Per bug #18147 from Hans Buschmann. Amit Langote and Tom Lane Discussion: https://postgr.es/m/18147-6fc796538913ee88@postgresql.org
* Fix misbehavior of EvalPlanQual checks with multiple result relations.Tom Lane2023-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea of EvalPlanQual is that we replace the query's scan of the result relation with a single injected tuple, and see if we get a tuple out, thereby implying that the injected tuple still passes the query quals. (In join cases, other relations in the query are still scanned normally.) This logic was not updated when commit 86dc90056 made it possible for a single DML query plan to have multiple result relations, when the query target relation has inheritance or partition children. We replaced the output for the current result relation successfully, but other result relations were still scanned normally; thus, if any other result relation contained a tuple satisfying the quals, we'd think the EPQ check passed, even if it did not pass for the injected tuple itself. This would lead to update or delete actions getting performed when they should have been skipped due to a conflicting concurrent update in READ COMMITTED isolation mode. Fix by blocking all sibling result relations from emitting tuples during an EvalPlanQual recheck. In the back branches, the fix is complicated a bit by the need to not change the size of struct EPQState (else we'd have ABI-breaking changes in offsets in struct ModifyTableState). Like the back-patches of 3f7836ff6 and 4b3e37993, add a separately palloc'd struct to avoid that. The logic is the same as in HEAD otherwise. This is only a live bug back to v14 where 86dc90056 came in. However, I chose to back-patch the test cases further, on the grounds that this whole area is none too well tested. I skipped doing so in v11 though because none of the test applied cleanly, and it didn't quite seem worth extra work for a branch with only six months to live. Per report from Ante Krešić (via Aleksander Alekseev) Discussion: https://postgr.es/m/CAJ7c6TMBTN3rcz4=AjYhLPD_w3FFT0Wq_C15jxCDn8U4tZnH1g@mail.gmail.com
* Fix buffer refcount leak with FDW bulk insertsMichael Paquier2023-04-25
| | | | | | | | | | | | | | | | | | | | | The leak would show up when using batch inserts with foreign tables included in a partition tree, as the slots used in the batch were not reset once processed. In order to fix this problem, some ExecClearTuple() are added to clean up the slots used once a batch is filled and processed, mapping with the number of slots currently in use as tracked by the counter ri_NumSlots. This buffer refcount leak has been introduced in b676ac4 with the addition of the executor facility to improve bulk inserts for FDWs, so backpatch down to 14. Alexander has provided the patch (slightly modified by me). The test for postgres_fdw comes from me, based on the test case that the author has sent in the report. Author: Alexander Pyhalov Discussion: https://postgr.es/m/b035780a740efd38dc30790c76927255@postgrespro.ru Backpatch-through: 14
* 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
* Make new GENERATED-expressions code more bulletproof.Tom Lane2023-01-15
| | | | | | | | | | | | | | | | | In commit 8bf6ec3ba I assumed that no code path could reach ExecGetExtraUpdatedCols without having gone through ExecInitStoredGenerated. That turns out not to be the case in logical replication: if there's an ON UPDATE trigger on the target table, trigger.c will call this code before anybody has set up its generated columns. Having seen that, I don't have a lot of faith in there not being other such paths. ExecGetExtraUpdatedCols can call ExecInitStoredGenerated for itself, as long as we are willing to assume that it is only called in CMD_UPDATE operations, which on the whole seems like a safer leap of faith. Per report from Vitaly Davydov. Discussion: https://postgr.es/m/d259d69652b8c2ff50e14cda3c236c7f@postgrespro.ru
* Fix calculation of which GENERATED columns need to be updated.Tom Lane2023-01-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We were identifying the updatable generated columns of inheritance children by transposing the calculation made for their parent. However, there's nothing that says a traditional-inheritance child can't have generated columns that aren't there in its parent, or that have different dependencies than are in the parent's expression. (At present it seems that we don't enforce that for partitioning either, which is likely wrong to some degree or other; but the case clearly needs to be handled with traditional inheritance.) Hence, drop the very-klugy-anyway "extraUpdatedCols" RTE field in favor of identifying which generated columns depend on updated columns during executor startup. In HEAD we can remove extraUpdatedCols altogether; in back branches, it's still there but always empty. Another difference between the HEAD and back-branch versions of this patch is that in HEAD we can add the new bitmap field to ResultRelInfo, but that would cause an ABI break in back branches. Like 4b3e37993, add a List field at the end of struct EState instead. Back-patch to v13. The bogus calculation is also being made in v12, but it doesn't have the same visible effect because we don't use it to decide which generated columns to recalculate; as a consequence of which the patch doesn't apply easily. I think that there might still be a demonstrable bug associated with trigger firing conditions, but that's such a weird corner-case usage that I'm content to leave it unfixed in v12. Amit Langote and Tom Lane Discussion: https://postgr.es/m/CA+HiwqFshLKNvQUd1DgwJ-7tsTp=dwv7KZqXC4j2wYBV1aCDUA@mail.gmail.com Discussion: https://postgr.es/m/2793383.1672944799@sss.pgh.pa.us
* Remove new structure member from ResultRelInfo.Etsuro Fujita2022-12-08
| | | | | | | | | | | | | | | In commit ffbb7e65a, I added a ModifyTableState member to ResultRelInfo to save the owning ModifyTableState for use by nodeModifyTable.c when performing batch inserts, but as pointed out by Tom Lane, that changed the array stride of es_result_relations, and that would break any previously-compiled extension code that accesses that array. Fix by removing that member from ResultRelInfo and instead adding a List member at the end of EState to save such ModifyTableStates. Per report from Tom Lane. Back-patch to v14, like the previous commit; I chose to apply the patch to HEAD as well, to make back-patching easy. Discussion: http://postgr.es/m/4065383.1669395453%40sss.pgh.pa.us
* Fix handling of pending inserts in nodeModifyTable.c.Etsuro Fujita2022-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b663a4136, which allowed FDWs to INSERT rows in bulk, added to nodeModifyTable.c code to flush pending inserts to the foreign-table result relation(s) before completing processing of the ModifyTable node, but the code failed to take into account the case where the INSERT query has modifying CTEs, leading to incorrect results. Also, that commit failed to flush pending inserts before firing BEFORE ROW triggers so that rows are visible to such triggers. In that commit we scanned through EState's es_tuple_routing_result_relations or es_opened_result_relations list to find the foreign-table result relations to which pending inserts are flushed, but that would be inefficient in some cases. So to fix, 1) add a List member to EState to record the insert-pending result relations, and 2) modify nodeModifyTable.c so that it adds the foreign-table result relation to the list in ExecInsert() if appropriate, and flushes pending inserts properly using the list where needed. While here, fix a copy-and-pasteo in a comment in ExecBatchInsert(), which was added by that commit. Back-patch to v14 where that commit appeared. Discussion: https://postgr.es/m/CAPmGK16qutyCmyJJzgQOhfBq%3DNoGDqTB6O0QBZTihrbqre%2BoxA%40mail.gmail.com
* Fix copy-and-pasteo in comment.Etsuro Fujita2022-11-02
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* Update comment in ExecInsert() regarding batch insertion.Etsuro Fujita2022-09-29
| | | | | | | | | | | | Remove the stale text that is a leftover from an earlier version of the patch to add support for batch insertion, and adjust the wording in the remaining text. Back-patch to v14 where batch insertion came in. Review and wording adjustment by Tom Lane. Discussion: https://postgr.es/m/CAPmGK14goatHPHQv2Aeu_UTKqZ%2BBO%2BP%2Bzd3HKv5D%2BdyyfWKDSw%40mail.gmail.com
* 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
* Use appropriate tuple descriptor in FDW batchingTomas Vondra2021-08-12
| | | | | | | | | | | | | | | The FDW batching code was using the same tuple descriptor both for all slots (regular and plan slots), but that's incorrect - the subplan may use a different descriptor. Currently this is benign, because batching is used only for INSERTs, and in that case the descriptors always match. But that would change if we allow batching UPDATEs. Fix by copying the appropriate tuple descriptor. Backpatch to 14, where the FDW batching was implemented. Author: Amit Langote Backpatch-through: 14, where FDW batching was added Discussion: https://postgr.es/m/CA%2BHiwqEWd5B0-e-RvixGGUrNvGkjH2s4m95%3DJcwUnyV%3Df0rAKQ%40mail.gmail.com
* Pre branch pgindent / pgperltidy runAndrew Dunstan2021-06-28
| | | | | Along the way make a slight adjustment to src/include/utils/queryjumble.h to avoid an unused typedef.
* Fix copying data into slots with FDW batchingTomas Vondra2021-06-16
| | | | | | | | | | | | | | | | Commit b676ac443b optimized handling of tuple slots with bulk inserts into foreign tables, so that the slots are initialized only once and reused for all batches. The data was however copied into the slots only after the initialization, inserting duplicate values when the slot gets reused. Fixed by moving the ExecCopySlot outside the init branch. The existing postgres_fdw tests failed to catch this due to inserting data into foreign tables without unique indexes, and then checking only the number of inserted rows. This adds a new test with both a unique index and a check of inserted values. Reported-by: Alexander Pyhalov Discussion: https://postgr.es/m/7a8cf8d56b3d18e5c0bccd6cd42d04ac%40postgrespro.ru
* Optimize creation of slots for FDW bulk insertsTomas Vondra2021-06-11
| | | | | | | | | | | | | | | | | | | | | | Commit b663a41363 introduced bulk inserts for FDW, but the handling of tuple slots turned out to be problematic for two reasons. Firstly, the slots were re-created for each individual batch. Secondly, all slots referenced the same tuple descriptor - with reasonably small batches this is not an issue, but with large batches this triggers O(N^2) behavior in the resource owner code. These two issues work against each other - to reduce the number of times a slot has to be created/dropped, larger batches are needed. However, the larger the batch, the more expensive the resource owner gets. For practical batch sizes (100 - 1000) this would not be a big problem, as the benefits (latency savings) greatly exceed the resource owner costs. But for extremely large batches it might be much worse, possibly even losing with non-batching mode. Fixed by initializing tuple slots only once (and reusing them across batches) and by using a new tuple descriptor copy for each slot. Discussion: https://postgr.es/m/ebbbcc7d-4286-8c28-0272-61b4753af761%40enterprisedb.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
* Initial pgindent and pgperltidy run for v14.Tom Lane2021-05-12
| | | | | | | | 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.
* 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
* Comment cleanup for a1115fa07.Tom Lane2021-04-07
| | | | | | Amit Langote Discussion: https://postgr.es/m/CA+HiwqEcawatEaUh1uTbZMEZTJeLzbroRTz9_X9Z5CFjTWJkhw@mail.gmail.com
* Postpone some more stuff out of ExecInitModifyTable.Tom Lane2021-04-06
| | | | | | | | | | | | | | | | | | Delay creation of the projections for INSERT and UPDATE tuples until they're needed. This saves a pretty fair amount of work when only some of the partitions are actually touched. The logic associated with identifying junk columns in UPDATE/DELETE is moved to another loop, allowing removal of one loop over the target relations; but it didn't actually change at all. Extracted from a larger patch, which seemed to me to be too messy to push in one commit. Amit Langote, reviewed at different times by Heikki Linnakangas and myself Discussion: https://postgr.es/m/CA+HiwqG7ZruBmmih3wPsBZ4s0H2EhywrnXEduckY5Hr3fWzPWA@mail.gmail.com
* Postpone some stuff out of ExecInitModifyTable.Tom Lane2021-04-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arrange to do some things on-demand, rather than immediately during executor startup, because there's a fair chance of never having to do them at all: * Don't open result relations' indexes until needed. * Don't initialize partition tuple routing, nor the child-to-root tuple conversion map, until needed. This wins in UPDATEs on partitioned tables when only some of the partitions will actually receive updates; with larger partition counts the savings is quite noticeable. Also, we can remove some sketchy heuristics in ExecInitModifyTable about whether to set up tuple routing. Also, remove execPartition.c's private hash table tracking which partitions were already opened by the ModifyTable node. Instead use the hash added to ModifyTable itself by commit 86dc90056. To allow lazy computation of the conversion maps, we now set ri_RootResultRelInfo in all child ResultRelInfos. We formerly set it only in some, not terribly well-defined, cases. This has user-visible side effects in that now more error messages refer to the root relation instead of some partition (and provide error data in the root's column order, too). It looks to me like this is a strict improvement in consistency, so I don't have a problem with the output changes visible in this commit. Extracted from a larger patch, which seemed to me to be too messy to push in one commit. Amit Langote, reviewed at different times by Heikki Linnakangas and myself Discussion: https://postgr.es/m/CA+HiwqG7ZruBmmih3wPsBZ4s0H2EhywrnXEduckY5Hr3fWzPWA@mail.gmail.com
* Rework planning and execution of UPDATE and DELETE.Tom Lane2021-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes two closely related sets of changes: 1. For UPDATE, the subplan of the ModifyTable node now only delivers the new values of the changed columns (i.e., the expressions computed in the query's SET clause) plus row identity information such as CTID. ModifyTable must re-fetch the original tuple to merge in the old values of any unchanged columns. The core advantage of this is that the changed columns are uniform across all tables of an inherited or partitioned target relation, whereas the other columns might not be. A secondary advantage, when the UPDATE involves joins, is that less data needs to pass through the plan tree. The disadvantage of course is an extra fetch of each tuple to be updated. However, that seems to be very nearly free in context; even worst-case tests don't show it to add more than a couple percent to the total query cost. At some point it might be interesting to combine the re-fetch with the tuple access that ModifyTable must do anyway to mark the old tuple dead; but that would require a good deal of refactoring and it seems it wouldn't buy all that much, so this patch doesn't attempt it. 2. For inherited UPDATE/DELETE, instead of generating a separate subplan for each target relation, we now generate a single subplan that is just exactly like a SELECT's plan, then stick ModifyTable on top of that. To let ModifyTable know which target relation a given incoming row refers to, a tableoid junk column is added to the row identity information. This gets rid of the horrid hack that was inheritance_planner(), eliminating O(N^2) planning cost and memory consumption in cases where there were many unprunable target relations. Point 2 of course requires point 1, so that there is a uniform definition of the non-junk columns to be returned by the subplan. We can't insist on uniform definition of the row identity junk columns however, if we want to keep the ability to have both plain and foreign tables in a partitioning hierarchy. Since it wouldn't scale very far to have every child table have its own row identity column, this patch includes provisions to merge similar row identity columns into one column of the subplan result. In particular, we can merge the whole-row Vars typically used as row identity by FDWs into one column by pretending they are type RECORD. (It's still okay for the actual composite Datums to be labeled with the table's rowtype OID, though.) There is more that can be done to file down residual inefficiencies in this patch, but it seems to be committable now. FDW authors should note several API changes: * The argument list for AddForeignUpdateTargets() has changed, and so has the method it must use for adding junk columns to the query. Call add_row_identity_var() instead of manipulating the parse tree directly. You might want to reconsider exactly what you're adding, too. * PlanDirectModify() must now work a little harder to find the ForeignScan plan node; if the foreign table is part of a partitioning hierarchy then the ForeignScan might not be the direct child of ModifyTable. See postgres_fdw for sample code. * To check whether a relation is a target relation, it's no longer sufficient to compare its relid to root->parse->resultRelation. Instead, check it against all_result_relids or leaf_result_relids, as appropriate. Amit Langote and Tom Lane Discussion: https://postgr.es/m/CA+HiwqHpHdqdDn48yCEhynnniahH78rwcrv1rEX65-fsZGBOLQ@mail.gmail.com
* 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 initialization of FDW batching in ExecInitModifyTableTomas Vondra2021-01-21
| | | | | | | | | | ExecInitModifyTable has to initialize batching for all result relations, not just the first one. Furthermore, when junk filters were necessary, the pointer pointed past the mtstate->resultRelInfo array. Per reports from multiple non-x86 animals (florican, locust, ...). Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* Implement support for bulk inserts in postgres_fdwTomas Vondra2021-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Extends the FDW API to allow batching inserts into foreign tables. That is usually much more efficient than inserting individual rows, due to high latency for each round-trip to the foreign server. It was possible to implement something similar in the regular FDW API, but it was inconvenient and there were issues with reporting the number of actually inserted rows etc. This extends the FDW API with two new functions: * GetForeignModifyBatchSize - allows the FDW picking optimal batch size * ExecForeignBatchInsert - inserts a batch of rows at once Currently, only INSERT queries support batching. Support for DELETE and UPDATE may be added in the future. This also implements batching for postgres_fdw. The batch size may be specified using "batch_size" option both at the server and table level. The initial patch version was written by me, but it was rewritten and improved in many ways by Takayuki Tsunakawa. Author: Takayuki Tsunakawa Reviewed-by: Tomas Vondra, Amit Langote Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* Pass down "logically unchanged index" hint.Peter Geoghegan2021-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an executor aminsert() hint mechanism that informs index AMs that the incoming index tuple (the tuple that accompanies the hint) is not being inserted by execution of an SQL statement that logically modifies any of the index's key columns. The hint is received by indexes when an UPDATE takes place that does not apply an optimization like heapam's HOT (though only for indexes where all key columns are logically unchanged). Any index tuple that receives the hint on insert is expected to be a duplicate of at least one existing older version that is needed for the same logical row. Related versions will typically be stored on the same index page, at least within index AMs that apply the hint. Recognizing the difference between MVCC version churn duplicates and true logical row duplicates at the index AM level can help with cleanup of garbage index tuples. Cleanup can intelligently target tuples that are likely to be garbage, without wasting too many cycles on less promising tuples/pages (index pages with little or no version churn). This is infrastructure for an upcoming commit that will teach nbtree to perform bottom-up index deletion. No index AM actually applies the hint just yet. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Victor Yegorov <vyegorov@gmail.com> Discussion: https://postgr.es/m/CAH2-Wz=CEKFa74EScx_hFVshCOn6AA5T-ajFASTdzipdkLTNQQ@mail.gmail.com
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Remove useless variable storesAlvaro Herrera2020-12-15
| | | | | Mistakenly introduced in 4cbe3ac3e867; bug repaired in 148e632c0541 but the stores were accidentally.
* Remove catalog function currtid()Michael Paquier2020-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | currtid() and currtid2() are an undocumented set of functions whose sole known user is the Postgres ODBC driver, able to retrieve the latest TID version for a tuple given by the caller of those functions. As used by Postgres ODBC, currtid() is a shortcut able to retrieve the last TID loaded into a backend by passing an OID of 0 (magic value) after a tuple insertion. This is removed in this commit, as it became obsolete after the driver began using "RETURNING ctid" with inserts, a clause supported since Postgres 8.2 (using RETURNING is better for performance anyway as it reduces the number of round-trips to the backend). currtid2() is still used by the driver, so this remains around for now. Note that this function is kept in its original shape for backward compatibility reasons. Per discussion with many people, including Andres Freund, Peter Eisentraut, Álvaro Herrera, Hiroshi Inoue, Tom Lane and myself. Bump catalog version. Discussion: https://postgr.es/m/20200603021448.GB89559@paquier.xyz
* In INSERT/UPDATE, use the table's real tuple descriptor as target.Tom Lane2020-10-26
| | | | | | | | | | | | | | | | | | | | | | | Previously, ExecInitModifyTable relied on ExecInitJunkFilter, and thence ExecCleanTypeFromTL, to build the target descriptor from the query tlist. While we just checked (in ExecCheckPlanOutput) that the tlist produces compatible output, this is not a great substitute for the relation's actual tuple descriptor that's available from the relcache. For one thing, dropped columns will not be correctly marked attisdropped; it's a bit surprising that we've gotten away with that this long. But the real reason for being concerned with this is that using the table's descriptor means that the slot will have correct attrmissing data, allowing us to revert the klugy fix of commit ba9f18abd. (This commit undoes that one's changes in trigger.c, but keeps the new test case.) Thus we can solve the bogus-trigger-tuple problem with fewer cycles rather than more. No back-patch, since this doesn't fix any additional bug, and it seems somewhat more likely to have unforeseen side effects than ba9f18abd's narrow fix. Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
* Remove PartitionRoutingInfo struct.Heikki Linnakangas2020-10-19
| | | | | | | | | | The extra indirection neeeded to access its members via its enclosing ResultRelInfo seems pointless. Move all the fields from PartitionRoutingInfo to ResultRelInfo. Author: Amit Langote Reviewed-by: Alvaro Herrera Discussion: https://www.postgresql.org/message-id/CA%2BHiwqFViT47Zbr_ASBejiK7iDG8%3DQ1swQ-tjM6caRPQ67pT%3Dw%40mail.gmail.com
* Revise child-to-root tuple conversion map management.Heikki Linnakangas2020-10-19
| | | | | | | | | | | | | | | | | | | | | | | Store the tuple conversion map to convert a tuple from a child table's format to the root format in a new ri_ChildToRootMap field in ResultRelInfo. It is initialized if transition tuple capture for FOR STATEMENT triggers or INSERT tuple routing on a partitioned table is needed. Previously, ModifyTable kept the maps in the per-subplan ModifyTableState->mt_per_subplan_tupconv_maps array, or when tuple routing was used, in ResultRelInfo->ri_Partitioninfo->pi_PartitionToRootMap. The new field replaces both of those. Now that the child-to-root tuple conversion map is always available in ResultRelInfo (when needed), remove the TransitionCaptureState.tcs_map field. The callers of Exec*Trigger() functions no longer need to set or save it, which is much less confusing and bug-prone. Also, as a future optimization, this will allow us to delay creating the map for a given result relation until the relation is actually processed during execution. Author: Amit Langote Discussion: https://www.postgresql.org/message-id/CA%2BHiwqHtCWLdK-LO%3DNEsvOdHx%2B7yv4mE_zYK0i3BH7dXb-wxog%40mail.gmail.com
* Clean up code to resolve the "root target relation" in nodeModifyTable.cHeikki Linnakangas2020-10-19
| | | | | | | | | | | | | | | | | When executing DDL on a partitioned table or on a table with inheritance children, statement-level triggers must be fired against the table given in the original statement. The code to look that up was a bit messy and duplicative. Commit 501ed02cf6 added a helper function, getASTriggerResultRelInfo() (later renamed to getTargetResultRelInfo()) for it, but for some reason it was only used when firing AFTER STATEMENT triggers and the code to fire BEFORE STATEMENT triggers duplicated the logic. Determine the target relation in ExecInitModifyTable(), and set it always in ModifyTableState. Code that used to call getTargetResultRelInfo() can now use ModifyTableState->rootResultRelInfo directly. Discussion: https://www.postgresql.org/message-id/CA%2BHiwqFViT47Zbr_ASBejiK7iDG8%3DQ1swQ-tjM6caRPQ67pT%3Dw%40mail.gmail.com
* Refactor code for cross-partition updates to a separate function.Heikki Linnakangas2020-10-15
| | | | | | | | | ExecUpdate() is very long, so extract the part of it that deals with cross-partition updates to a separate function to make it more readable. Per Andres Freund's suggestion. Author: Amit Langote Discussion: https://www.postgresql.org/message-id/CA%2BHiwqEUgb5RdUgxR7Sqco4S09jzJstHiaT2vnCRPGR4JCAPqA%40mail.gmail.com
* Remove es_result_relation_info from EState.Heikki Linnakangas2020-10-14
| | | | | | | | | | | | | | Maintaining 'es_result_relation_info' correctly at all times has become cumbersome, especially with partitioning where each partition gets its own result relation info. Having to set and reset it across arbitrary operations has caused bugs in the past. This changes all the places that used 'es_result_relation_info', to receive the currently active ResultRelInfo via function parameters instead. Author: Amit Langote Discussion: https://www.postgresql.org/message-id/CA%2BHiwqGEmiib8FLiHMhKB%2BCH5dRgHSLc5N5wnvc4kym%2BZYpQEQ%40mail.gmail.com
* Create ResultRelInfos later in InitPlan, index them by RT index.Heikki Linnakangas2020-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of allocating all the ResultRelInfos upfront in one big array, allocate them in ExecInitModifyTable(). es_result_relations is now an array of ResultRelInfo pointers, rather than an array of structs, and it is indexed by the RT index. This simplifies things: we get rid of the separate concept of a "result rel index", and don't need to set it in setrefs.c anymore. This also allows follow-up optimizations (not included in this commit yet) to skip initializing ResultRelInfos for target relations that were not needed at runtime, and removal of the es_result_relation_info pointer. The EState arrays of regular result rels and root result rels are merged into one array. Similarly, the resultRelations and rootResultRelations lists in PlannedStmt are merged into one. It's not actually clear to me why they were kept separate in the first place, but now that the es_result_relations array is indexed by RT index, it certainly seems pointless. The PlannedStmt->resultRelations list is now only needed for ExecRelationIsTargetRelation(). One visible effect of this change is that ExecRelationIsTargetRelation() will now return 'true' also for the partition root, if a partitioned table is updated. That seems like a good thing, although the function isn't used in core code, and I don't see any reason for an FDW to call it on a partition root. Author: Amit Langote Discussion: https://www.postgresql.org/message-id/CA%2BHiwqGEmiib8FLiHMhKB%2BCH5dRgHSLc5N5wnvc4kym%2BZYpQEQ%40mail.gmail.com
* Don't fetch partition check expression during InitResultRelInfo.Tom Lane2020-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since there is only one place that actually needs the partition check expression, namely ExecPartitionCheck, it's better to fetch it from the relcache there. In this way we will never fetch it at all if the query never has use for it, and we still fetch it just once when we do need it. The reason for taking an interest in this is that if the relcache doesn't already have the check expression cached, fetching it requires obtaining AccessShareLock on the partition root. That means that operations that look like they should only touch the partition itself will also take a lock on the root. In particular we observed that TRUNCATE on a partition may take a lock on the partition's root, contributing to a deadlock situation in parallel pg_restore. As written, this patch does have a small cost, which is that we are microscopically reducing efficiency for the case where a partition has an empty check expression. ExecPartitionCheck will be called, and will go through the motions of setting up and checking an empty qual, where before it would not have been called at all. We could avoid that by adding a separate boolean flag to track whether there is a partition expression to test. However, this case only arises for a default partition with no siblings, which surely is not an interesting case in practice. Hence adding complexity for it does not seem like a good trade-off. Amit Langote, per a suggestion by me Discussion: https://postgr.es/m/VI1PR03MB31670CA1BD9625C3A8C5DD05EB230@VI1PR03MB3167.eurprd03.prod.outlook.com
* Fix possible crash with GENERATED ALWAYS columnsDavid Rowley2020-04-18
| | | | | | | | | | | | | | | | | | In some corner cases, this could also lead to corrupted values being included in the tuple. Users who are concerned that they are affected by this should first upgrade and then perform a base backup of their database and restore onto an off-line server. They should then query each table with generated columns to ensure there are no rows where the generated expression does not match a newly calculated version of the GENERATED ALWAYS expression. If no crashes occur and no rows are returned then you're not affected. Fixes bug #16369. Reported-by: Cameron Ezell Discussion: https://postgr.es/m/16369-5845a6f1bef59884@postgresql.org Backpatch-through: 12 (where GENERATED ALWAYS columns were added.)
* Optimize update of tables with generated columnsPeter Eisentraut2020-02-17
| | | | | | | | | | | When updating a table row with generated columns, only recompute those generated columns whose base columns have changed in this update and keep the rest unchanged. This can result in a significant performance benefit. The required information was already kept in RangeTblEntry.extraUpdatedCols; we just have to make use of it. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/b05e781a-fa16-6b52-6738-761181204567@2ndquadrant.com
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Further adjust EXPLAIN's choices of table alias names.Tom Lane2019-12-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch causes EXPLAIN to always assign a separate table alias to the parent RTE of an append relation (inheritance set); before, such RTEs were ignored if not actually scanned by the plan. Since the child RTEs now always have that same alias to start with (cf. commit 55a1954da), the net effect is that the parent RTE usually gets the alias used or implied by the query text, and the children all get that alias with "_N" appended. (The exception to "usually" is if there are duplicate aliases in different subtrees of the original query; then some of those original RTEs will also have "_N" appended.) This results in more uniform output for partitioned-table plans than we had before: the partitioned table itself gets the original alias, and all child tables have aliases with "_N", rather than the previous behavior where one of the children would get an alias without "_N". The reason for giving the parent RTE an alias, even if it isn't scanned by the plan, is that we now use the parent's alias to qualify Vars that refer to an appendrel output column and appear above the Append or MergeAppend that computes the appendrel. But below the append, Vars refer to some one of the child relations, and are displayed that way. This seems clearer than the old behavior where a Var that could carry values from any child relation was displayed as if it referred to only one of them. While at it, change ruleutils.c so that the code paths used by EXPLAIN deal in Plan trees not PlanState trees. This effectively reverts a decision made in commit 1cc29fe7c, which seemed like a good idea at the time to make ruleutils.c consistent with explain.c. However, it's problematic because we'd really like to allow executor startup pruning to remove all the children of an append node when possible, leaving no child PlanState to resolve Vars against. (That's not done here, but will be in the next patch.) This requires different handling of subplans and initplans than before, but is otherwise a pretty straightforward change. Discussion: https://postgr.es/m/001001d4f44b$2a2cca50$7e865ef0$@lab.ntt.co.jp
* Fix whitespace.Etsuro Fujita2019-12-04
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* Reorder EPQ work, to fix rowmark related bugs and improve efficiency.Andres Freund2019-09-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In ad0bda5d24ea I changed the EvalPlanQual machinery to store substitution tuples in slot, instead of using plain HeapTuples. The main motivation for that was that using HeapTuples will be inefficient for future tableams. But it turns out that that conversion was buggy for non-locking rowmarks - the wrong tuple descriptor was used to create the slot. As a secondary issue 5db6df0c0 changed ExecLockRows() to begin EPQ earlier, to allow to fetch the locked rows directly into the EPQ slots, instead of having to copy tuples around. Unfortunately, as Tom complained, that forces some expensive initialization to happen earlier. As a third issue, the test coverage for EPQ was clearly insufficient. Fixing the first issue is unfortunately not trivial: Non-locked row marks were fetched at the start of EPQ, and we don't have the type information for the rowmarks available at that point. While we could change that, it's not easy. It might be worthwhile to change that at some point, but to fix this bug, it seems better to delay fetching non-locking rowmarks when they're actually needed, rather than eagerly. They're referenced at most once, and in cases where EPQ fails, might never be referenced. Fetching them when needed also increases locality a bit. To be able to fetch rowmarks during execution, rather than initialization, we need to be able to access the active EPQState, as that contains necessary data. To do so move EPQ related data from EState to EPQState, and, only for EStates creates as part of EPQ, reference the associated EPQState from EState. To fix the second issue, change EPQ initialization to allow use of EvalPlanQualSlot() to be used before EvalPlanQualBegin() (but obviously still requiring EvalPlanQualInit() to have been done). As these changes made struct EState harder to understand, e.g. by adding multiple EStates, significantly reorder the members, and add a lot more comments. Also add a few more EPQ tests, including one that fails for the first issue above. More is needed. Reported-By: yi huang Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/CAHU7rYZo_C4ULsAx_LAj8az9zqgrD8WDd4hTegDTMM1LMqrBsg@mail.gmail.com https://postgr.es/m/24530.1562686693@sss.pgh.pa.us Backpatch: 12-, where the EPQ changes were introduced
* Remove 'msg' parameter from convert_tuples_by_nameAlvaro Herrera2019-09-03
| | | | | | | | | | The message was included as a parameter when this function was added in dcb2bda9b704, but I don't think it has ever served any useful purpose. Let's stop spreading it pointlessly. Reviewed by Amit Langote and Peter Eisentraut. Discussion: https://postgr.es/m/20190806224728.GA17233@alvherre.pgsql
* Fix system column accesses in ON CONFLICT ... RETURNING.Andres Freund2019-07-24
| | | | | | | | | | | | | | | | | After 277cb789836 ON CONFLICT ... SET ... RETURNING failed with ERROR: virtual tuple table slot does not have system attributes when taking the update path, as the slot used to insert into the table (and then process RETURNING) was defined to be a virtual slot in that commit. Virtual slots don't support system columns except for tableoid and ctid, as the other system columns are AM dependent. Fix that by using a slot of the table's type. Add tests for system column accesses in ON CONFLICT ... RETURNING. Reported-By: Roby, bisected to the relevant commit by Jeff Janes Author: Andres Freund Discussion: https://postgr.es/m/73436355-6432-49B1-92ED-1FE4F7E7E100@finefun.com.au Backpatch: 12-, where the bug was introduced in 277cb789836
* pgindent run prior to branching v12.Tom Lane2019-07-01
| | | | | pgperltidy and reformat-dat-files too, though the latter didn't find anything to change.
* Fix assorted inconsistencies.Amit Kapila2019-06-08
| | | | | | | | | | There were a number of issues in the recent commits which include typos, code and comments mismatch, leftover function declarations. Fix them. Reported-by: Alexander Lakhin Author: Alexander Lakhin, Amit Kapila and Amit Langote Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/ef0c0232-0c1d-3a35-63d4-0ebd06e31387@gmail.com
* tableam: Rename wrapper functions to match callback names.Andres Freund2019-05-23
| | | | | | | | | | | | | | | | Some of the wrapper functions didn't match the callback names. Many of them due to staying "consistent" with historic naming of the wrapped functionality. We decided that for most cases it's more important to be for tableam to be consistent going forward, than with the past. The one exception is beginscan/endscan/... because it'd have looked odd to have systable_beginscan/endscan/... with a different naming scheme, and changing the systable_* APIs would have caused way too much churn (including breaking a lot of external users). Author: Ashwin Agrawal, with some small additions by Andres Freund Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CALfoeiugyrXZfX7n0ORCa4L-m834dzmaE8eFdbNR6PMpetU4Ww@mail.gmail.com