/*------------------------------------------------------------------------- * * nodeModifyTable.c * routines to handle ModifyTable nodes. * * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/executor/nodeModifyTable.c * *------------------------------------------------------------------------- */ /* INTERFACE ROUTINES * ExecInitModifyTable - initialize the ModifyTable node * ExecModifyTable - retrieve the next tuple from the node * ExecEndModifyTable - shut down the ModifyTable node * ExecReScanModifyTable - rescan the ModifyTable node * * NOTES * Each ModifyTable node contains a list of one or more subplans, * much like an Append node. There is one subplan per result relation. * The key reason for this is that in an inherited UPDATE command, each * result relation could have a different schema (more or different * columns) requiring a different plan tree to produce it. In an * inherited DELETE, all the subplans should produce the same output * rowtype, but we might still find that different plans are appropriate * for different child relations. * * If the query specifies RETURNING, then the ModifyTable returns a * RETURNING tuple after completing each row insert, update, or delete. * It must be called again to continue the operation. Without RETURNING, * we just loop within the node until all the work is done, then * return NULL. This avoids useless call/return overhead. */ #include "postgres.h" #include "access/heapam.h" #include "access/htup_details.h" #include "access/xact.h" #include "catalog/catalog.h" #include "commands/trigger.h" #include "executor/execPartition.h" #include "executor/executor.h" #include "executor/nodeModifyTable.h" #include "foreign/fdwapi.h" #include "miscadmin.h" #include "nodes/nodeFuncs.h" #include "storage/bufmgr.h" #include "storage/lmgr.h" #include "utils/builtins.h" #include "utils/memutils.h" #include "utils/rel.h" static bool ExecOnConflictUpdate(ModifyTableState *mtstate, ResultRelInfo *resultRelInfo, ItemPointer conflictTid, TupleTableSlot *planSlot, TupleTableSlot *excludedSlot, EState *estate, bool canSetTag, TupleTableSlot **returning); static TupleTableSlot *ExecPrepareTupleRouting(ModifyTableState *mtstate, EState *estate, PartitionTupleRouting *proute, ResultRelInfo *targetRelInfo, TupleTableSlot *slot); static ResultRelInfo *getTargetResultRelInfo(ModifyTableState *node); static void ExecSetupChildParentMapForSubplan(ModifyTableState *mtstate); static TupleConversionMap *tupconv_map_for_subplan(ModifyTableState *node, int whichplan); /* * Verify that the tuples to be produced by INSERT or UPDATE match the * target relation's rowtype * * We do this to guard against stale plans. If plan invalidation is * functioning properly then we should never get a failure here, but better * safe than sorry. Note that this is called after we have obtained lock * on the target rel, so the rowtype can't change underneath us. * * The plan output is represented by its targetlist, because that makes * handling the dropped-column case easier. */ static void ExecCheckPlanOutput(Relation resultRel, List *targetList) { TupleDesc resultDesc = RelationGetDescr(resultRel); int attno = 0; ListCell *lc; foreach(lc, targetList) { TargetEntry *tle = (TargetEntry *) lfirst(lc); Form_pg_attribute attr; if (tle->resjunk) continue; /* ignore junk tlist items */ if (attno >= resultDesc->natts) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table row type and query-specified row type do not match"), errdetail("Query has too many columns."))); attr = TupleDescAttr(resultDesc, attno); attno++; if (!attr->attisdropped) { /* Normal case: demand type match */ if (exprType((Node *) tle->expr) != attr->atttypid) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table row type and query-specified row type do not match"), errdetail("Table has type %s at ordinal position %d, but query expects %s.", format_type_be(attr->atttypid), attno, format_type_be(exprType((Node *) tle->expr))))); } else { /* * For a dropped column, we can't check atttypid (it's likely 0). * In any case the planner has most likely inserted an INT4 null. * What we insist on is just *some* NULL constant. */ if (!IsA(tle->expr, Const) || !((Const *) tle->expr)->constisnull) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table row type and query-specified row type do not match"), errdetail("Query provides a value for a dropped column at ordinal position %d.", attno))); } } if (attno != resultDesc->natts) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table row type and query-specified row type do not match"), errdetail("Query has too few columns."))); } /* * ExecProcessReturning --- evaluate a RETURNING list * * resultRelInfo: current result rel * tupleSlot: slot holding tuple actually inserted/updated/deleted * planSlot: slot holding tuple returned by top subplan node * * Note: If tupleSlot is NULL, the FDW should have already provided econtext's * scan tuple. * * Returns a slot holding the result tuple */ static TupleTableSlot * ExecProcessReturning(ResultRelInfo *resultRelInfo, TupleTableSlot *tupleSlot, TupleTableSlot *planSlot) { ProjectionInfo *projectReturning = resultRelInfo->ri_projectReturning; ExprContext *econtext = projectReturning->pi_exprContext; /* Make tuple and any needed join variables available to ExecProject */ if (tupleSlot) econtext->ecxt_scantuple = tupleSlot; econtext->ecxt_outertuple = planSlot; /* * RETURNING expressions might reference the tableoid column, so * reinitialize tts_tableOid before evaluating them. */ econtext->ecxt_scantuple->tts_tableOid = RelationGetRelid(resultRelInfo->ri_RelationDesc); /* Compute the RETURNING expressions */ return ExecProject(projectReturning); } /* * ExecCheckHeapTupleVisible -- verify heap tuple is visible * * It would not be consistent with guarantees of the higher isolation levels to * proceed with avoiding insertion (taking speculative insertion's alternative * path) on the basis of another tuple that is not visible to MVCC snapshot. * Check for the need to raise a serialization failure, and do so as necessary. */ static void ExecCheckHeapTupleVisible(EState *estate, HeapTuple tuple, Buffer buffer) { if (!IsolationUsesXactSnapshot()) return; /* * We need buffer pin and lock to call HeapTupleSatisfiesVisibility. * Caller should be holding pin, but not lock. */ LockBuffer(buffer, BUFFER_LOCK_SHARE); if (!HeapTupleSatisfiesVisibility(tuple, estate->es_snapshot, buffer)) { /* * We should not raise a serialization failure if the conflict is * against a tuple inserted by our own transaction, even if it's not * visible to our snapshot. (This would happen, for example, if * conflicting keys are proposed for insertion in a single command.) */ if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple->t_data))) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("could not serialize access due to concurrent update"))); } LockBuffer(buffer, BUFFER_LOCK_UNLOCK); } /* * ExecCheckTIDVisible -- convenience variant of ExecCheckHeapTupleVisible() */ static void ExecCheckTIDVisible(EState *estate, ResultRelInfo *relinfo, ItemPointer tid) { Relation rel = relinfo->ri_RelationDesc; Buffer buffer; HeapTupleData tuple; /* Redundantly check isolation level */ if (!IsolationUsesXactSnapshot()) return; tuple.t_self = *tid; if (!heap_fetch(rel, SnapshotAny, &tuple, &buffer, false, NULL)) elog(ERROR, "failed to fetch conflicting tuple for ON CONFLICT"); ExecCheckHeapTupleVisible(estate, &tuple, buffer); ReleaseBuffer(buffer); } /* ---------------------------------------------------------------- * ExecInsert * * For INSERT, we have to insert the tuple into the target relation * and insert appropriate tuples into the index relations. * * Returns RETURNING result if any, otherwise NULL. * ---------------------------------------------------------------- */ static TupleTableSlot * ExecInsert(ModifyTableState *mtstate, TupleTableSlot *slot, TupleTableSlot *planSlot, EState *estate, bool canSetTag) { ResultRelInfo *resultRelInfo; Relation resultRelationDesc; List *recheckIndexes = NIL; TupleTableSlot *result = NULL; TransitionCaptureState *ar_insert_trig_tcs; ModifyTable *node = (ModifyTable *) mtstate->ps.plan; OnConflictAction onconflict = node->onConflictAction; ExecMaterializeSlot(slot); /* * get information on the (current) result relation */ resultRelInfo = estate->es_result_relation_info; resultRelationDesc = resultRelInfo->ri_RelationDesc; /* * BEFORE ROW INSERT Triggers. * * Note: We fire BEFORE ROW TRIGGERS for every attempted insertion in an * INSERT ... ON CONFLICT statement. We cannot check for constraint * violations before firing these triggers, because they can change the * values to insert. Also, they can run arbitrary user-defined code with * side-effects that we can't cancel by just not inserting the tuple. */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_insert_before_row) { if (!ExecBRInsertTriggers(estate, resultRelInfo, slot)) return NULL; /* "do nothing" */ } /* INSTEAD OF ROW INSERT Triggers */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_insert_instead_row) { if (!ExecIRInsertTriggers(estate, resultRelInfo, slot)) return NULL; /* "do nothing" */ } else if (resultRelInfo->ri_FdwRoutine) { /* * insert into foreign table: let the FDW do it */ slot = resultRelInfo->ri_FdwRoutine->ExecForeignInsert(estate, resultRelInfo, slot, planSlot); if (slot == NULL) /* "do nothing" */ return NULL; /* * AFTER ROW Triggers or RETURNING expressions might reference the * tableoid column, so (re-)initialize tts_tableOid before evaluating * them. */ slot->tts_tableOid = RelationGetRelid(resultRelInfo->ri_RelationDesc); } else { WCOKind wco_kind; HeapTuple inserttuple; /* * Constraints might reference the tableoid column, so (re-)initialize * tts_tableOid before evaluating them. */ slot->tts_tableOid = RelationGetRelid(resultRelationDesc); /* * Check any RLS WITH CHECK policies. * * Normally we should check INSERT policies. But if the insert is the * result of a partition key update that moved the tuple to a new * partition, we should instead check UPDATE policies, because we are * executing policies defined on the target table, and not those * defined on the child partitions. */ wco_kind = (mtstate->operation == CMD_UPDATE) ? WCO_RLS_UPDATE_CHECK : WCO_RLS_INSERT_CHECK; /* * ExecWithCheckOptions() will skip any WCOs which are not of the kind * we are looking for at this point. */ if (resultRelInfo->ri_WithCheckOptions != NIL) ExecWithCheckOptions(wco_kind, resultRelInfo, slot, estate); /* * Check the constraints of the tuple. */ if (resultRelationDesc->rd_att->constr) ExecConstraints(resultRelInfo, slot, estate); /* * Also check the tuple against the partition constraint, if there is * one; except that if we got here via tuple-routing, we don't need to * if there's no BR trigger defined on the partition. */ if (resultRelInfo->ri_PartitionCheck && (resultRelInfo->ri_PartitionRoot == NULL || (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_insert_before_row))) ExecPartitionCheck(resultRelInfo, slot, estate, true); if (onconflict != ONCONFLICT_NONE && resultRelInfo->ri_NumIndices > 0) { /* Perform a speculative insertion. */ uint32 specToken; ItemPointerData conflictTid; bool specConflict; List *arbiterIndexes; arbiterIndexes = resultRelInfo->ri_onConflictArbiterIndexes; /* * Do a non-conclusive check for conflicts first. * * We're not holding any locks yet, so this doesn't guarantee that * the later insert won't conflict. But it avoids leaving behind * a lot of canceled speculative insertions, if you run a lot of * INSERT ON CONFLICT statements that do conflict. * * We loop back here if we find a conflict below, either during * the pre-check, or when we re-check after inserting the tuple * speculatively. */ vlock: specConflict = false; if (!ExecCheckIndexConstraints(slot, estate, &conflictTid, arbiterIndexes)) { /* committed conflict tuple found */ if (onconflict == ONCONFLICT_UPDATE) { /* * In case of ON CONFLICT DO UPDATE, execute the UPDATE * part. Be prepared to retry if the UPDATE fails because * of another concurrent UPDATE/DELETE to the conflict * tuple. */ TupleTableSlot *returning = NULL; if (ExecOnConflictUpdate(mtstate, resultRelInfo, &conflictTid, planSlot, slot, estate, canSetTag, &returning)) { InstrCountTuples2(&mtstate->ps, 1); return returning; } else goto vlock; } else { /* * In case of ON CONFLICT DO NOTHING, do nothing. However, * verify that the tuple is visible to the executor's MVCC * snapshot at higher isolation levels. */ Assert(onconflict == ONCONFLICT_NOTHING); ExecCheckTIDVisible(estate, resultRelInfo, &conflictTid); InstrCountTuples2(&mtstate->ps, 1); return NULL; } } inserttuple = ExecFetchSlotHeapTuple(slot, true, NULL); /* * Before we start insertion proper, acquire our "speculative * insertion lock". Others can use that to wait for us to decide * if we're going to go ahead with the insertion, instead of * waiting for the whole transaction to complete. */ specToken = SpeculativeInsertionLockAcquire(GetCurrentTransactionId()); HeapTupleHeaderSetSpeculativeToken(inserttuple->t_data, specToken); /* insert the tuple, with the speculative token */ heap_insert(resultRelationDesc, inserttuple, estate->es_output_cid, HEAP_INSERT_SPECULATIVE, NULL); slot->tts_tableOid = RelationGetRelid(resultRelationDesc); ItemPointerCopy(&inserttuple->t_self, &slot->tts_tid); /* insert index entries for tuple */ recheckIndexes = ExecInsertIndexTuples(slot, &(inserttuple->t_self), estate, true, &specConflict, arbiterIndexes); /* adjust the tuple's state accordingly */ if (!specConflict) heap_finish_speculative(resultRelationDesc, inserttuple); else heap_abort_speculative(resultRelationDesc, inserttuple); /* * Wake up anyone waiting for our decision. They will re-check * the tuple, see that it's no longer speculative, and wait on our * XID as if this was a regularly inserted tuple all along. Or if * we killed the tuple, they will see it's dead, and proceed as if * the tuple never existed. */ SpeculativeInsertionLockRelease(GetCurrentTransactionId()); /* * If there was a conflict, start from the beginning. We'll do * the pre-check again, which will now find the conflicting tuple * (unless it aborts before we get there). */ if (specConflict) { list_free(recheckIndexes); goto vlock; } /* Since there was no insertion conflict, we're done */ } else { /* * insert the tuple normally. * * Note: heap_insert returns the tid (location) of the new tuple * in the t_self field. */ inserttuple = ExecFetchSlotHeapTuple(slot, true, NULL); heap_insert(resultRelationDesc, inserttuple, estate->es_output_cid, 0, NULL); slot->tts_tableOid = RelationGetRelid(resultRelationDesc); ItemPointerCopy(&inserttuple->t_self, &slot->tts_tid); /* insert index entries for tuple */ if (resultRelInfo->ri_NumIndices > 0) recheckIndexes = ExecInsertIndexTuples(slot, &(inserttuple->t_self), estate, false, NULL, NIL); } } if (canSetTag) { (estate->es_processed)++; setLastTid(&slot->tts_tid); } /* * If this insert is the result of a partition key update that moved the * tuple to a new partition, put this row into the transition NEW TABLE, * if there is one. We need to do this separately for DELETE and INSERT * because they happen on different tables. */ ar_insert_trig_tcs = mtstate->mt_transition_capture; if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_capture && mtstate->mt_transition_capture->tcs_update_new_table) { ExecARUpdateTriggers(estate, resultRelInfo, NULL, NULL, slot, NULL, mtstate->mt_transition_capture); /* * We've already captured the NEW TABLE row, so make sure any AR * INSERT trigger fired below doesn't capture it again. */ ar_insert_trig_tcs = NULL; } /* AFTER ROW INSERT Triggers */ ExecARInsertTriggers(estate, resultRelInfo, slot, recheckIndexes, ar_insert_trig_tcs); list_free(recheckIndexes); /* * Check any WITH CHECK OPTION constraints from parent views. We are * required to do this after testing all constraints and uniqueness * violations per the SQL spec, so we do it after actually inserting the * record into the heap and all indexes. * * ExecWithCheckOptions will elog(ERROR) if a violation is found, so the * tuple will never be seen, if it violates the WITH CHECK OPTION. * * ExecWithCheckOptions() will skip any WCOs which are not of the kind we * are looking for at this point. */ if (resultRelInfo->ri_WithCheckOptions != NIL) ExecWithCheckOptions(WCO_VIEW_CHECK, resultRelInfo, slot, estate); /* Process RETURNING if present */ if (resultRelInfo->ri_projectReturning) result = ExecProcessReturning(resultRelInfo, slot, planSlot); return result; } /* ---------------------------------------------------------------- * ExecDelete * * DELETE is like UPDATE, except that we delete the tuple and no * index modifications are needed. * * When deleting from a table, tupleid identifies the tuple to * delete and oldtuple is NULL. When deleting from a view, * oldtuple is passed to the INSTEAD OF triggers and identifies * what to delete, and tupleid is invalid. When deleting from a * foreign table, tupleid is invalid; the FDW has to figure out * which row to delete using data from the planSlot. oldtuple is * passed to foreign table triggers; it is NULL when the foreign * table has no relevant triggers. We use tupleDeleted to indicate * whether the tuple is actually deleted, callers can use it to * decide whether to continue the operation. When this DELETE is a * part of an UPDATE of partition-key, then the slot returned by * EvalPlanQual() is passed back using output parameter epqslot. * * Returns RETURNING result if any, otherwise NULL. * ---------------------------------------------------------------- */ static TupleTableSlot * ExecDelete(ModifyTableState *mtstate, ItemPointer tupleid, HeapTuple oldtuple, TupleTableSlot *planSlot, EPQState *epqstate, EState *estate, bool processReturning, bool canSetTag, bool changingPart, bool *tupleDeleted, TupleTableSlot **epqreturnslot) { ResultRelInfo *resultRelInfo; Relation resultRelationDesc; HTSU_Result result; HeapUpdateFailureData hufd; TupleTableSlot *slot = NULL; TransitionCaptureState *ar_delete_trig_tcs; if (tupleDeleted) *tupleDeleted = false; /* * get information on the (current) result relation */ resultRelInfo = estate->es_result_relation_info; resultRelationDesc = resultRelInfo->ri_RelationDesc; /* BEFORE ROW DELETE Triggers */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_delete_before_row) { bool dodelete; dodelete = ExecBRDeleteTriggers(estate, epqstate, resultRelInfo, tupleid, oldtuple, epqreturnslot); if (!dodelete) /* "do nothing" */ return NULL; } /* INSTEAD OF ROW DELETE Triggers */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_delete_instead_row) { bool dodelete; Assert(oldtuple != NULL); dodelete = ExecIRDeleteTriggers(estate, resultRelInfo, oldtuple); if (!dodelete) /* "do nothing" */ return NULL; } else if (resultRelInfo->ri_FdwRoutine) { /* * delete from foreign table: let the FDW do it * * We offer the returning slot as a place to store RETURNING data, * although the FDW can return some other slot if it wants. */ slot = ExecGetReturningSlot(estate, resultRelInfo); slot = resultRelInfo->ri_FdwRoutine->ExecForeignDelete(estate, resultRelInfo, slot, planSlot); if (slot == NULL) /* "do nothing" */ return NULL; /* * RETURNING expressions might reference the tableoid column, so * (re)initialize tts_tableOid before evaluating them. */ if (TTS_EMPTY(slot)) ExecStoreAllNullTuple(slot); slot->tts_tableOid = RelationGetRelid(resultRelationDesc); } else { /* * delete the tuple * * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check * that the row to be deleted is visible to that snapshot, and throw a * can't-serialize error if not. This is a special-case behavior * needed for referential integrity updates in transaction-snapshot * mode transactions. */ ldelete:; result = heap_delete(resultRelationDesc, tupleid, estate->es_output_cid, estate->es_crosscheck_snapshot, true /* wait for commit */ , &hufd, changingPart); switch (result) { case HeapTupleSelfUpdated: /* * The target tuple was already updated or deleted by the * current command, or by a later command in the current * transaction. The former case is possible in a join DELETE * where multiple tuples join to the same target tuple. This * is somewhat questionable, but Postgres has always allowed * it: we just ignore additional deletion attempts. * * The latter case arises if the tuple is modified by a * command in a BEFORE trigger, or perhaps by a command in a * volatile function used in the query. In such situations we * should not ignore the deletion, but it is equally unsafe to * proceed. We don't want to discard the original DELETE * while keeping the triggered actions based on its deletion; * and it would be no better to allow the original DELETE * while discarding updates that it triggered. The row update * carries some information that might be important according * to business rules; so throwing an error is the only safe * course. * * If a trigger actually intends this type of interaction, it * can re-execute the DELETE and then return NULL to cancel * the outer delete. */ if (hufd.cmax != estate->es_output_cid) ereport(ERROR, (errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION), errmsg("tuple to be updated was already modified by an operation triggered by the current command"), errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows."))); /* Else, already deleted by self; nothing to do */ return NULL; case HeapTupleMayBeUpdated: break; case HeapTupleUpdated: if (IsolationUsesXactSnapshot()) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("could not serialize access due to concurrent update"))); if (ItemPointerIndicatesMovedPartitions(&hufd.ctid)) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("tuple to be deleted was already moved to another partition due to concurrent update"))); if (!ItemPointerEquals(tupleid, &hufd.ctid)) { TupleTableSlot *my_epqslot; my_epqslot = EvalPlanQual(estate, epqstate, resultRelationDesc, resultRelInfo->ri_RangeTableIndex, LockTupleExclusive, &hufd.ctid, hufd.xmax); if (!TupIsNull(my_epqslot)) { *tupleid = hufd.ctid; /* * If requested, skip delete and pass back the updated * row. */ if (epqreturnslot) { *epqreturnslot = my_epqslot; return NULL; } else goto ldelete; } } /* tuple already deleted; nothing to do */ return NULL; default: elog(ERROR, "unrecognized heap_delete status: %u", result); return NULL; } /* * Note: Normally one would think that we have to delete index tuples * associated with the heap tuple now... * * ... but in POSTGRES, we have no need to do this because VACUUM will * take care of it later. We can't delete index tuples immediately * anyway, since the tuple is still visible to other transactions. */ } if (canSetTag) (estate->es_processed)++; /* Tell caller that the delete actually happened. */ if (tupleDeleted) *tupleDeleted = true; /* * If this delete is the result of a partition key update that moved the * tuple to a new partition, put this row into the transition OLD TABLE, * if there is one. We need to do this separately for DELETE and INSERT * because they happen on different tables. */ ar_delete_trig_tcs = mtstate->mt_transition_capture; if (mtstate->operation == CMD_UPDATE && mtstate->mt_transition_capture && mtstate->mt_transition_capture->tcs_update_old_table) { ExecARUpdateTriggers(estate, resultRelInfo, tupleid, oldtuple, NULL, NULL, mtstate->mt_transition_capture); /* * We've already captured the NEW TABLE row, so make sure any AR * DELETE trigger fired below doesn't capture it again. */ ar_delete_trig_tcs = NULL; } /* AFTER ROW DELETE Triggers */ ExecARDeleteTriggers(estate, resultRelInfo, tupleid, oldtuple, ar_delete_trig_tcs); /* Process RETURNING if present and if requested */ if (processReturning && resultRelInfo->ri_projectReturning) { /* * We have to put the target tuple into a slot, which means first we * gotta fetch it. We can use the trigger tuple slot. */ TupleTableSlot *rslot; if (resultRelInfo->ri_FdwRoutine) { /* FDW must have provided a slot containing the deleted row */ Assert(!TupIsNull(slot)); } else { slot = ExecGetReturningSlot(estate, resultRelInfo); if (oldtuple != NULL) { ExecForceStoreHeapTuple(oldtuple, slot); } else { BufferHeapTupleTableSlot *bslot; HeapTuple deltuple; Buffer buffer; Assert(TTS_IS_BUFFERTUPLE(slot)); ExecClearTuple(slot); bslot = (BufferHeapTupleTableSlot *) slot; deltuple = &bslot->base.tupdata; deltuple->t_self = *tupleid; if (!heap_fetch(resultRelationDesc, SnapshotAny, deltuple, &buffer, false, NULL)) elog(ERROR, "failed to fetch deleted tuple for DELETE RETURNING"); ExecStorePinnedBufferHeapTuple(deltuple, slot, buffer); } } rslot = ExecProcessReturning(resultRelInfo, slot, planSlot); /* * Before releasing the target tuple again, make sure rslot has a * local copy of any pass-by-reference values. */ ExecMaterializeSlot(rslot); ExecClearTuple(slot); return rslot; } return NULL; } /* ---------------------------------------------------------------- * ExecUpdate * * note: we can't run UPDATE queries with transactions * off because UPDATEs are actually INSERTs and our * scan will mistakenly loop forever, updating the tuple * it just inserted.. This should be fixed but until it * is, we don't want to get stuck in an infinite loop * which corrupts your database.. * * When updating a table, tupleid identifies the tuple to * update and oldtuple is NULL. When updating a view, oldtuple * is passed to the INSTEAD OF triggers and identifies what to * update, and tupleid is invalid. When updating a foreign table, * tupleid is invalid; the FDW has to figure out which row to * update using data from the planSlot. oldtuple is passed to * foreign table triggers; it is NULL when the foreign table has * no relevant triggers. * * Returns RETURNING result if any, otherwise NULL. * ---------------------------------------------------------------- */ static TupleTableSlot * ExecUpdate(ModifyTableState *mtstate, ItemPointer tupleid, HeapTuple oldtuple, TupleTableSlot *slot, TupleTableSlot *planSlot, EPQState *epqstate, EState *estate, bool canSetTag) { HeapTuple updatetuple; ResultRelInfo *resultRelInfo; Relation resultRelationDesc; HTSU_Result result; HeapUpdateFailureData hufd; List *recheckIndexes = NIL; TupleConversionMap *saved_tcs_map = NULL; /* * abort the operation if not running transactions */ if (IsBootstrapProcessingMode()) elog(ERROR, "cannot UPDATE during bootstrap"); ExecMaterializeSlot(slot); /* * get information on the (current) result relation */ resultRelInfo = estate->es_result_relation_info; resultRelationDesc = resultRelInfo->ri_RelationDesc; /* BEFORE ROW UPDATE Triggers */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_update_before_row) { if (!ExecBRUpdateTriggers(estate, epqstate, resultRelInfo, tupleid, oldtuple, slot)) return NULL; /* "do nothing" */ } /* INSTEAD OF ROW UPDATE Triggers */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_update_instead_row) { if (!ExecIRUpdateTriggers(estate, resultRelInfo, oldtuple, slot)) return NULL; /* "do nothing" */ } else if (resultRelInfo->ri_FdwRoutine) { /* * update in foreign table: let the FDW do it */ slot = resultRelInfo->ri_FdwRoutine->ExecForeignUpdate(estate, resultRelInfo, slot, planSlot); if (slot == NULL) /* "do nothing" */ return NULL; /* * AFTER ROW Triggers or RETURNING expressions might reference the * tableoid column, so (re-)initialize tts_tableOid before evaluating * them. */ slot->tts_tableOid = RelationGetRelid(resultRelationDesc); } else { LockTupleMode lockmode; bool partition_constraint_failed; /* * Constraints might reference the tableoid column, so (re-)initialize * tts_tableOid before evaluating them. */ slot->tts_tableOid = RelationGetRelid(resultRelationDesc); /* * Check any RLS UPDATE WITH CHECK policies * * If we generate a new candidate tuple after EvalPlanQual testing, we * must loop back here and recheck any RLS policies and constraints. * (We don't need to redo triggers, however. If there are any BEFORE * triggers then trigger.c will have done heap_lock_tuple to lock the * correct tuple, so there's no need to do them again.) */ lreplace:; /* * If partition constraint fails, this row might get moved to another * partition, in which case we should check the RLS CHECK policy just * before inserting into the new partition, rather than doing it here. * This is because a trigger on that partition might again change the * row. So skip the WCO checks if the partition constraint fails. */ partition_constraint_failed = resultRelInfo->ri_PartitionCheck && !ExecPartitionCheck(resultRelInfo, slot, estate, false); if (!partition_constraint_failed && resultRelInfo->ri_WithCheckOptions != NIL) { /* * ExecWithCheckOptions() will skip any WCOs which are not of the * kind we are looking for at this point. */ ExecWithCheckOptions(WCO_RLS_UPDATE_CHECK, resultRelInfo, slot, estate); } /* * If a partition check failed, try to move the row into the right * partition. */ if (partition_constraint_failed) { bool tuple_deleted; TupleTableSlot *ret_slot; TupleTableSlot *epqslot = NULL; PartitionTupleRouting *proute = mtstate->mt_partition_tuple_routing; int map_index; TupleConversionMap *tupconv_map; /* * Disallow an INSERT ON CONFLICT DO UPDATE that causes the * original row to migrate to a different partition. Maybe this * can be implemented some day, but it seems a fringe feature with * little redeeming value. */ if (((ModifyTable *) mtstate->ps.plan)->onConflictAction == ONCONFLICT_UPDATE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("invalid ON UPDATE specification"), errdetail("The result tuple would appear in a different partition than the original tuple."))); /* * When an UPDATE is run on a leaf partition, we will not have * partition tuple routing set up. In that case, fail with * partition constraint violation error. */ if (proute == NULL) ExecPartitionCheckEmitError(resultRelInfo, slot, estate); /* * Row movement, part 1. Delete the tuple, but skip RETURNING * processing. We want to return rows from INSERT. */ ExecDelete(mtstate, tupleid, oldtuple, planSlot, epqstate, estate, false, false /* canSetTag */ , true /* changingPart */ , &tuple_deleted, &epqslot); /* * For some reason if DELETE didn't happen (e.g. trigger prevented * it, or it was already deleted by self, or it was concurrently * deleted by another transaction), then we should skip the insert * as well; otherwise, an UPDATE could cause an increase in the * total number of rows across all partitions, which is clearly * wrong. * * For a normal UPDATE, the case where the tuple has been the * subject of a concurrent UPDATE or DELETE would be handled by * the EvalPlanQual machinery, but for an UPDATE that we've * translated into a DELETE from this partition and an INSERT into * some other partition, that's not available, because CTID chains * can't span relation boundaries. We mimic the semantics to a * limited extent by skipping the INSERT if the DELETE fails to * find a tuple. This ensures that two concurrent attempts to * UPDATE the same tuple at the same time can't turn one tuple * into two, and that an UPDATE of a just-deleted tuple can't * resurrect it. */ if (!tuple_deleted) { /* * epqslot will be typically NULL. But when ExecDelete() * finds that another transaction has concurrently updated the * same row, it re-fetches the row, skips the delete, and * epqslot is set to the re-fetched tuple slot. In that case, * we need to do all the checks again. */ if (TupIsNull(epqslot)) return NULL; else { slot = ExecFilterJunk(resultRelInfo->ri_junkFilter, epqslot); goto lreplace; } } /* * Updates set the transition capture map only when a new subplan * is chosen. But for inserts, it is set for each row. So after * INSERT, we need to revert back to the map created for UPDATE; * otherwise the next UPDATE will incorrectly use the one created * for INSERT. So first save the one created for UPDATE. */ if (mtstate->mt_transition_capture) saved_tcs_map = mtstate->mt_transition_capture->tcs_map; /* * resultRelInfo is one of the per-subplan resultRelInfos. So we * should convert the tuple into root's tuple descriptor, since * ExecInsert() starts the search from root. The tuple conversion * map list is in the order of mtstate->resultRelInfo[], so to * retrieve the one for this resultRel, we need to know the * position of the resultRel in mtstate->resultRelInfo[]. */ map_index = resultRelInfo - mtstate->resultRelInfo; Assert(map_index >= 0 && map_index < mtstate->mt_nplans); tupconv_map = tupconv_map_for_subplan(mtstate, map_index); if (tupconv_map != NULL) slot = execute_attr_map_slot(tupconv_map->attrMap, slot, mtstate->mt_root_tuple_slot); /* * Prepare for tuple routing, making it look like we're inserting * into the root. */ Assert(mtstate->rootResultRelInfo != NULL); slot = ExecPrepareTupleRouting(mtstate, estate, proute, mtstate->rootResultRelInfo, slot); ret_slot = ExecInsert(mtstate, slot, planSlot, estate, canSetTag); /* Revert ExecPrepareTupleRouting's node change. */ estate->es_result_relation_info = resultRelInfo; if (mtstate->mt_transition_capture) { mtstate->mt_transition_capture->tcs_original_insert_tuple = NULL; mtstate->mt_transition_capture->tcs_map = saved_tcs_map; } return ret_slot; } /* * Check the constraints of the tuple. We've already checked the * partition constraint above; however, we must still ensure the tuple * passes all other constraints, so we will call ExecConstraints() and * have it validate all remaining checks. */ if (resultRelationDesc->rd_att->constr) ExecConstraints(resultRelInfo, slot, estate); /* * replace the heap tuple * * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check * that the row to be updated is visible to that snapshot, and throw a * can't-serialize error if not. This is a special-case behavior * needed for referential integrity updates in transaction-snapshot * mode transactions. */ updatetuple = ExecFetchSlotHeapTuple(slot, true, NULL); result = heap_update(resultRelationDesc, tupleid, updatetuple, estate->es_output_cid, estate->es_crosscheck_snapshot, true /* wait for commit */ , &hufd, &lockmode); ItemPointerCopy(&updatetuple->t_self, &slot->tts_tid); switch (result) { case HeapTupleSelfUpdated: /* * The target tuple was already updated or deleted by the * current command, or by a later command in the current * transaction. The former case is possible in a join UPDATE * where multiple tuples join to the same target tuple. This * is pretty questionable, but Postgres has always allowed it: * we just execute the first update action and ignore * additional update attempts. * * The latter case arises if the tuple is modified by a * command in a BEFORE trigger, or perhaps by a command in a * volatile function used in the query. In such situations we * should not ignore the update, but it is equally unsafe to * proceed. We don't want to discard the original UPDATE * while keeping the triggered actions based on it; and we * have no principled way to merge this update with the * previous ones. So throwing an error is the only safe * course. * * If a trigger actually intends this type of interaction, it * can re-execute the UPDATE (assuming it can figure out how) * and then return NULL to cancel the outer update. */ if (hufd.cmax != estate->es_output_cid) ereport(ERROR, (errcode(ERRCODE_TRIGGERED_DATA_CHANGE_VIOLATION), errmsg("tuple to be updated was already modified by an operation triggered by the current command"), errhint("Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows."))); /* Else, already updated by self; nothing to do */ return NULL; case HeapTupleMayBeUpdated: break; case HeapTupleUpdated: if (IsolationUsesXactSnapshot()) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("could not serialize access due to concurrent update"))); if (ItemPointerIndicatesMovedPartitions(&hufd.ctid)) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("tuple to be updated was already moved to another partition due to concurrent update"))); if (!ItemPointerEquals(tupleid, &hufd.ctid)) { TupleTableSlot *epqslot; epqslot = EvalPlanQual(estate, epqstate, resultRelationDesc, resultRelInfo->ri_RangeTableIndex, lockmode, &hufd.ctid, hufd.xmax); if (!TupIsNull(epqslot)) { *tupleid = hufd.ctid; slot = ExecFilterJunk(resultRelInfo->ri_junkFilter, epqslot); goto lreplace; } } /* tuple already deleted; nothing to do */ return NULL; default: elog(ERROR, "unrecognized heap_update status: %u", result); return NULL; } /* * Note: instead of having to update the old index tuples associated * with the heap tuple, all we do is form and insert new index tuples. * This is because UPDATEs are actually DELETEs and INSERTs, and index * tuple deletion is done later by VACUUM (see notes in ExecDelete). * All we do here is insert new index tuples. -cim 9/27/89 */ /* * insert index entries for tuple * * Note: heap_update returns the tid (location) of the new tuple in * the t_self field. * * If it's a HOT update, we mustn't insert new index entries. */ if (resultRelInfo->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(updatetuple)) recheckIndexes = ExecInsertIndexTuples(slot, &(updatetuple->t_self), estate, false, NULL, NIL); } if (canSetTag) (estate->es_processed)++; /* AFTER ROW UPDATE Triggers */ ExecARUpdateTriggers(estate, resultRelInfo, tupleid, oldtuple, slot, recheckIndexes, mtstate->operation == CMD_INSERT ? mtstate->mt_oc_transition_capture : mtstate->mt_transition_capture); list_free(recheckIndexes); /* * Check any WITH CHECK OPTION constraints from parent views. We are * required to do this after testing all constraints and uniqueness * violations per the SQL spec, so we do it after actually updating the * record in the heap and all indexes. * * ExecWithCheckOptions() will skip any WCOs which are not of the kind we * are looking for at this point. */ if (resultRelInfo->ri_WithCheckOptions != NIL) ExecWithCheckOptions(WCO_VIEW_CHECK, resultRelInfo, slot, estate); /* Process RETURNING if present */ if (resultRelInfo->ri_projectReturning) return ExecProcessReturning(resultRelInfo, slot, planSlot); return NULL; } /* * ExecOnConflictUpdate --- execute UPDATE of INSERT ON CONFLICT DO UPDATE * * Try to lock tuple for update as part of speculative insertion. If * a qual originating from ON CONFLICT DO UPDATE is satisfied, update * (but still lock row, even though it may not satisfy estate's * snapshot). * * Returns true if we're done (with or without an update), or false if * the caller must retry the INSERT from scratch. */ static bool ExecOnConflictUpdate(ModifyTableState *mtstate, ResultRelInfo *resultRelInfo, ItemPointer conflictTid, TupleTableSlot *planSlot, TupleTableSlot *excludedSlot, EState *estate, bool canSetTag, TupleTableSlot **returning) { ExprContext *econtext = mtstate->ps.ps_ExprContext; Relation relation = resultRelInfo->ri_RelationDesc; ExprState *onConflictSetWhere = resultRelInfo->ri_onConflict->oc_WhereClause; HeapTupleData tuple; HeapUpdateFailureData hufd; LockTupleMode lockmode; HTSU_Result test; Buffer buffer; /* Determine lock mode to use */ lockmode = ExecUpdateLockMode(estate, resultRelInfo); /* * Lock tuple for update. Don't follow updates when tuple cannot be * locked without doing so. A row locking conflict here means our * previous conclusion that the tuple is conclusively committed is not * true anymore. */ tuple.t_self = *conflictTid; test = heap_lock_tuple(relation, &tuple, estate->es_output_cid, lockmode, LockWaitBlock, false, &buffer, &hufd); switch (test) { case HeapTupleMayBeUpdated: /* success! */ break; case HeapTupleInvisible: /* * This can occur when a just inserted tuple is updated again in * the same command. E.g. because multiple rows with the same * conflicting key values are inserted. * * This is somewhat similar to the ExecUpdate() * HeapTupleSelfUpdated case. We do not want to proceed because * it would lead to the same row being updated a second time in * some unspecified order, and in contrast to plain UPDATEs * there's no historical behavior to break. * * It is the user's responsibility to prevent this situation from * occurring. These problems are why SQL-2003 similarly specifies * that for SQL MERGE, an exception must be raised in the event of * an attempt to update the same row twice. */ if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple.t_data))) ereport(ERROR, (errcode(ERRCODE_CARDINALITY_VIOLATION), errmsg("ON CONFLICT DO UPDATE command cannot affect row a second time"), errhint("Ensure that no rows proposed for insertion within the same command have duplicate constrained values."))); /* This shouldn't happen */ elog(ERROR, "attempted to lock invisible tuple"); break; case HeapTupleSelfUpdated: /* * This state should never be reached. As a dirty snapshot is used * to find conflicting tuples, speculative insertion wouldn't have * seen this row to conflict with. */ elog(ERROR, "unexpected self-updated tuple"); break; case HeapTupleUpdated: if (IsolationUsesXactSnapshot()) ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("could not serialize access due to concurrent update"))); /* * As long as we don't support an UPDATE of INSERT ON CONFLICT for * a partitioned table we shouldn't reach to a case where tuple to * be lock is moved to another partition due to concurrent update * of the partition key. */ Assert(!ItemPointerIndicatesMovedPartitions(&hufd.ctid)); /* * Tell caller to try again from the very start. * * It does not make sense to use the usual EvalPlanQual() style * loop here, as the new version of the row might not conflict * anymore, or the conflicting tuple has actually been deleted. */ ReleaseBuffer(buffer); return false; default: elog(ERROR, "unrecognized heap_lock_tuple status: %u", test); } /* Success, the tuple is locked. */ /* * Verify that the tuple is visible to our MVCC snapshot if the current * isolation level mandates that. * * It's not sufficient to rely on the check within ExecUpdate() as e.g. * CONFLICT ... WHERE clause may prevent us from reaching that. * * This means we only ever continue when a new command in the current * transaction could see the row, even though in READ COMMITTED mode the * tuple will not be visible according to the current statement's * snapshot. This is in line with the way UPDATE deals with newer tuple * versions. */ ExecCheckHeapTupleVisible(estate, &tuple, buffer); /* Store target's existing tuple in the state's dedicated slot */ ExecStoreBufferHeapTuple(&tuple, mtstate->mt_existing, buffer); /* * Make tuple and any needed join variables available to ExecQual and * ExecProject. The EXCLUDED tuple is installed in ecxt_innertuple, while * the target's existing tuple is installed in the scantuple. EXCLUDED * has been made to reference INNER_VAR in setrefs.c, but there is no * other redirection. */ econtext->ecxt_scantuple = mtstate->mt_existing; econtext->ecxt_innertuple = excludedSlot; econtext->ecxt_outertuple = NULL; if (!ExecQual(onConflictSetWhere, econtext)) { ReleaseBuffer(buffer); InstrCountFiltered1(&mtstate->ps, 1); return true; /* done with the tuple */ } if (resultRelInfo->ri_WithCheckOptions != NIL) { /* * Check target's existing tuple against UPDATE-applicable USING * security barrier quals (if any), enforced here as RLS checks/WCOs. * * The rewriter creates UPDATE RLS checks/WCOs for UPDATE security * quals, and stores them as WCOs of "kind" WCO_RLS_CONFLICT_CHECK, * but that's almost the extent of its special handling for ON * CONFLICT DO UPDATE. * * The rewriter will also have associated UPDATE applicable straight * RLS checks/WCOs for the benefit of the ExecUpdate() call that * follows. INSERTs and UPDATEs naturally have mutually exclusive WCO * kinds, so there is no danger of spurious over-enforcement in the * INSERT or UPDATE path. */ ExecWithCheckOptions(WCO_RLS_CONFLICT_CHECK, resultRelInfo, mtstate->mt_existing, mtstate->ps.state); } /* Project the new tuple version */ ExecProject(resultRelInfo->ri_onConflict->oc_ProjInfo); /* * Note that it is possible that the target tuple has been modified in * this session, after the above heap_lock_tuple. We choose to not error * out in that case, in line with ExecUpdate's treatment of similar cases. * This can happen if an UPDATE is triggered from within ExecQual(), * ExecWithCheckOptions() or ExecProject() above, e.g. by selecting from a * wCTE in the ON CONFLICT's SET. */ /* Execute UPDATE with projection */ *returning = ExecUpdate(mtstate, &tuple.t_self, NULL, mtstate->mt_conflproj, planSlot, &mtstate->mt_epqstate, mtstate->ps.state, canSetTag); ReleaseBuffer(buffer); return true; } /* * Process BEFORE EACH STATEMENT triggers */ static void fireBSTriggers(ModifyTableState *node) { ModifyTable *plan = (ModifyTable *) node->ps.plan; ResultRelInfo *resultRelInfo = node->resultRelInfo; /* * If the node modifies a partitioned table, we must fire its triggers. * Note that in that case, node->resultRelInfo points to the first leaf * partition, not the root table. */ if (node->rootResultRelInfo != NULL) resultRelInfo = node->rootResultRelInfo; switch (node->operation) { case CMD_INSERT: ExecBSInsertTriggers(node->ps.state, resultRelInfo); if (plan->onConflictAction == ONCONFLICT_UPDATE) ExecBSUpdateTriggers(node->ps.state, resultRelInfo); break; case CMD_UPDATE: ExecBSUpdateTriggers(node->ps.state, resultRelInfo); break; case CMD_DELETE: ExecBSDeleteTriggers(node->ps.state, resultRelInfo); break; default: elog(ERROR, "unknown operation"); break; } } /* * Return the target rel ResultRelInfo. * * This relation is the same as : * - the relation for which we will fire AFTER STATEMENT triggers. * - the relation into whose tuple format all captured transition tuples must * be converted. * - the root partitioned table. */ static ResultRelInfo * getTargetResultRelInfo(ModifyTableState *node) { /* * Note that if the node modifies a partitioned table, node->resultRelInfo * points to the first leaf partition, not the root table. */ if (node->rootResultRelInfo != NULL) return node->rootResultRelInfo; else return node->resultRelInfo; } /* * Process AFTER EACH STATEMENT triggers */ static void fireASTriggers(ModifyTableState *node) { ModifyTable *plan = (ModifyTable *) node->ps.plan; ResultRelInfo *resultRelInfo = getTargetResultRelInfo(node); switch (node->operation) { case CMD_INSERT: if (plan->onConflictAction == ONCONFLICT_UPDATE) ExecASUpdateTriggers(node->ps.state, resultRelInfo, node->mt_oc_transition_capture); ExecASInsertTriggers(node->ps.state, resultRelInfo, node->mt_transition_capture); break; case CMD_UPDATE: ExecASUpdateTriggers(node->ps.state, resultRelInfo, node->mt_transition_capture); break; case CMD_DELETE: ExecASDeleteTriggers(node->ps.state, resultRelInfo, node->mt_transition_capture); break; default: elog(ERROR, "unknown operation"); break; } } /* * Set up the state needed for collecting transition tuples for AFTER * triggers. */ static void ExecSetupTransitionCaptureState(ModifyTableState *mtstate, EState *estate) { ModifyTable *plan = (ModifyTable *) mtstate->ps.plan; ResultRelInfo *targetRelInfo = getTargetResultRelInfo(mtstate); /* Check for transition tables on the directly targeted relation. */ mtstate->mt_transition_capture = MakeTransitionCaptureState(targetRelInfo->ri_TrigDesc, RelationGetRelid(targetRelInfo->ri_RelationDesc), mtstate->operation); if (plan->operation == CMD_INSERT && plan->onConflictAction == ONCONFLICT_UPDATE) mtstate->mt_oc_transition_capture = MakeTransitionCaptureState(targetRelInfo->ri_TrigDesc, RelationGetRelid(targetRelInfo->ri_RelationDesc), CMD_UPDATE); /* * If we found that we need to collect transition tuples then we may also * need tuple conversion maps for any children that have TupleDescs that * aren't compatible with the tuplestores. (We can share these maps * between the regular and ON CONFLICT cases.) */ if (mtstate->mt_transition_capture != NULL || mtstate->mt_oc_transition_capture != NULL) { ExecSetupChildParentMapForSubplan(mtstate); /* * Install the conversion map for the first plan for UPDATE and DELETE * operations. It will be advanced each time we switch to the next * plan. (INSERT operations set it every time, so we need not update * mtstate->mt_oc_transition_capture here.) */ if (mtstate->mt_transition_capture && mtstate->operation != CMD_INSERT) mtstate->mt_transition_capture->tcs_map = tupconv_map_for_subplan(mtstate, 0); } } /* * ExecPrepareTupleRouting --- prepare for routing one tuple * * Determine the partition in which the tuple in slot is to be inserted, * and modify mtstate and estate to prepare for it. * * Caller must revert the estate changes after executing the insertion! * In mtstate, transition capture changes may also need to be reverted. * * Returns a slot holding the tuple of the partition rowtype. */ static TupleTableSlot * ExecPrepareTupleRouting(ModifyTableState *mtstate, EState *estate, PartitionTupleRouting *proute, ResultRelInfo *targetRelInfo, TupleTableSlot *slot) { ModifyTable *node; ResultRelInfo *partrel; PartitionRoutingInfo *partrouteinfo; TupleConversionMap *map; /* * Lookup the target partition's ResultRelInfo. If ExecFindPartition does * not find a valid partition for the tuple in 'slot' then an error is * raised. An error may also be raised if the found partition is not a * valid target for INSERTs. This is required since a partitioned table * UPDATE to another partition becomes a DELETE+INSERT. */ partrel = ExecFindPartition(mtstate, targetRelInfo, proute, slot, estate); partrouteinfo = partrel->ri_PartitionInfo; Assert(partrouteinfo != NULL); /* * Make it look like we are inserting into the partition. */ estate->es_result_relation_info = partrel; /* * If we're capturing transition tuples, we might need to convert from the * partition rowtype to root partitioned table's rowtype. */ if (mtstate->mt_transition_capture != NULL) { if (partrel->ri_TrigDesc && partrel->ri_TrigDesc->trig_insert_before_row) { /* * If there are any BEFORE triggers on the partition, we'll have * to be ready to convert their result back to tuplestore format. */ mtstate->mt_transition_capture->tcs_original_insert_tuple = NULL; mtstate->mt_transition_capture->tcs_map = partrouteinfo->pi_PartitionToRootMap; } else { /* * Otherwise, just remember the original unconverted tuple, to * avoid a needless round trip conversion. */ mtstate->mt_transition_capture->tcs_original_insert_tuple = slot; mtstate->mt_transition_capture->tcs_map = NULL; } } if (mtstate->mt_oc_transition_capture != NULL) { mtstate->mt_oc_transition_capture->tcs_map = partrouteinfo->pi_PartitionToRootMap; } /* * Convert the tuple, if necessary. */ map = partrouteinfo->pi_RootToPartitionMap; if (map != NULL) { TupleTableSlot *new_slot = partrouteinfo->pi_PartitionTupleSlot; slot = execute_attr_map_slot(map->attrMap, slot, new_slot); } /* Initialize information needed to handle ON CONFLICT DO UPDATE. */ Assert(mtstate != NULL); node = (ModifyTable *) mtstate->ps.plan; if (node->onConflictAction == ONCONFLICT_UPDATE) { Assert(mtstate->mt_existing != NULL); ExecSetSlotDescriptor(mtstate->mt_existing, RelationGetDescr(partrel->ri_RelationDesc)); Assert(mtstate->mt_conflproj != NULL); ExecSetSlotDescriptor(mtstate->mt_conflproj, partrel->ri_onConflict->oc_ProjTupdesc); } return slot; } /* * Initialize the child-to-root tuple conversion map array for UPDATE subplans. * * This map array is required to convert the tuple from the subplan result rel * to the target table descriptor. This requirement arises for two independent * scenarios: * 1. For update-tuple-routing. * 2. For capturing tuples in transition tables. */ static void ExecSetupChildParentMapForSubplan(ModifyTableState *mtstate) { ResultRelInfo *targetRelInfo = getTargetResultRelInfo(mtstate); ResultRelInfo *resultRelInfos = mtstate->resultRelInfo; TupleDesc outdesc; int numResultRelInfos = mtstate->mt_nplans; int i; /* * Build array of conversion maps from each child's TupleDesc to the one * used in the target relation. The map pointers may be NULL when no * conversion is necessary, which is hopefully a common case. */ /* Get tuple descriptor of the target rel. */ outdesc = RelationGetDescr(targetRelInfo->ri_RelationDesc); mtstate->mt_per_subplan_tupconv_maps = (TupleConversionMap **) palloc(sizeof(TupleConversionMap *) * numResultRelInfos); for (i = 0; i < numResultRelInfos; ++i) { mtstate->mt_per_subplan_tupconv_maps[i] = convert_tuples_by_name(RelationGetDescr(resultRelInfos[i].ri_RelationDesc), outdesc, gettext_noop("could not convert row type")); } } /* * For a given subplan index, get the tuple conversion map. */ static TupleConversionMap * tupconv_map_for_subplan(ModifyTableState *mtstate, int whichplan) { /* If nobody else set the per-subplan array of maps, do so ourselves. */ if (mtstate->mt_per_subplan_tupconv_maps == NULL) ExecSetupChildParentMapForSubplan(mtstate); Assert(whichplan >= 0 && whichplan < mtstate->mt_nplans); return mtstate->mt_per_subplan_tupconv_maps[whichplan]; } /* ---------------------------------------------------------------- * ExecModifyTable * * Perform table modifications as required, and return RETURNING results * if needed. * ---------------------------------------------------------------- */ static TupleTableSlot * ExecModifyTable(PlanState *pstate) { ModifyTableState *node = castNode(ModifyTableState, pstate); PartitionTupleRouting *proute = node->mt_partition_tuple_routing; EState *estate = node->ps.state; CmdType operation = node->operation; ResultRelInfo *saved_resultRelInfo; ResultRelInfo *resultRelInfo; PlanState *subplanstate; JunkFilter *junkfilter; TupleTableSlot *slot; TupleTableSlot *planSlot; ItemPointer tupleid; ItemPointerData tuple_ctid; HeapTupleData oldtupdata; HeapTuple oldtuple; CHECK_FOR_INTERRUPTS(); /* * This should NOT get called during EvalPlanQual; we should have passed a * subplan tree to EvalPlanQual, instead. Use a runtime test not just * Assert because this condition is easy to miss in testing. (Note: * although ModifyTable should not get executed within an EvalPlanQual * operation, we do have to allow it to be initialized and shut down in * case it is within a CTE subplan. Hence this test must be here, not in * ExecInitModifyTable.) */ if (estate->es_epqTupleSlot != NULL) elog(ERROR, "ModifyTable should not be called during EvalPlanQual"); /* * If we've already completed processing, don't try to do more. We need * this test because ExecPostprocessPlan might call us an extra time, and * our subplan's nodes aren't necessarily robust against being called * extra times. */ if (node->mt_done) return NULL; /* * On first call, fire BEFORE STATEMENT triggers before proceeding. */ if (node->fireBSTriggers) { fireBSTriggers(node); node->fireBSTriggers = false; } /* Preload local variables */ resultRelInfo = node->resultRelInfo + node->mt_whichplan; subplanstate = node->mt_plans[node->mt_whichplan]; junkfilter = resultRelInfo->ri_junkFilter; /* * es_result_relation_info must point to the currently active result * relation while we are within this ModifyTable node. Even though * ModifyTable nodes can't be nested statically, they can be nested * dynamically (since our subplan could include a reference to a modifying * CTE). So we have to save and restore the caller's value. */ saved_resultRelInfo = estate->es_result_relation_info; estate->es_result_relation_info = resultRelInfo; /* * Fetch rows from subplan(s), and execute the required table modification * for each row. */ for (;;) { /* * Reset the per-output-tuple exprcontext. This is needed because * triggers expect to use that context as workspace. It's a bit ugly * to do this below the top level of the plan, however. We might need * to rethink this later. */ ResetPerTupleExprContext(estate); /* * Reset per-tuple memory context used for processing on conflict and * returning clauses, to free any expression evaluation storage * allocated in the previous cycle. */ if (pstate->ps_ExprContext) ResetExprContext(pstate->ps_ExprContext); planSlot = ExecProcNode(subplanstate); if (TupIsNull(planSlot)) { /* advance to next subplan if any */ node->mt_whichplan++; if (node->mt_whichplan < node->mt_nplans) { resultRelInfo++; subplanstate = node->mt_plans[node->mt_whichplan]; junkfilter = resultRelInfo->ri_junkFilter; estate->es_result_relation_info = resultRelInfo; EvalPlanQualSetPlan(&node->mt_epqstate, subplanstate->plan, node->mt_arowmarks[node->mt_whichplan]); /* Prepare to convert transition tuples from this child. */ if (node->mt_transition_capture != NULL) { node->mt_transition_capture->tcs_map = tupconv_map_for_subplan(node, node->mt_whichplan); } if (node->mt_oc_transition_capture != NULL) { node->mt_oc_transition_capture->tcs_map = tupconv_map_for_subplan(node, node->mt_whichplan); } continue; } else break; } /* * Ensure input tuple is the right format for the target relation. */ if (node->mt_scans[node->mt_whichplan]->tts_ops != planSlot->tts_ops) { ExecCopySlot(node->mt_scans[node->mt_whichplan], planSlot); planSlot = node->mt_scans[node->mt_whichplan]; } /* * If resultRelInfo->ri_usesFdwDirectModify is true, all we need to do * here is compute the RETURNING expressions. */ if (resultRelInfo->ri_usesFdwDirectModify) { Assert(resultRelInfo->ri_projectReturning); /* * A scan slot containing the data that was actually inserted, * updated or deleted has already been made available to * ExecProcessReturning by IterateDirectModify, so no need to * provide it here. */ slot = ExecProcessReturning(resultRelInfo, NULL, planSlot); estate->es_result_relation_info = saved_resultRelInfo; return slot; } EvalPlanQualSetSlot(&node->mt_epqstate, planSlot); slot = planSlot; tupleid = NULL; oldtuple = NULL; if (junkfilter != NULL) { /* * extract the 'ctid' or 'wholerow' junk attribute. */ if (operation == CMD_UPDATE || operation == CMD_DELETE) { char relkind; Datum datum; bool isNull; relkind = resultRelInfo->ri_RelationDesc->rd_rel->relkind; if (relkind == RELKIND_RELATION || relkind == RELKIND_MATVIEW) { datum = ExecGetJunkAttribute(slot, junkfilter->jf_junkAttNo, &isNull); /* shouldn't ever get a null result... */ if (isNull) elog(ERROR, "ctid is NULL"); tupleid = (ItemPointer) DatumGetPointer(datum); tuple_ctid = *tupleid; /* be sure we don't free ctid!! */ tupleid = &tuple_ctid; } /* * Use the wholerow attribute, when available, to reconstruct * the old relation tuple. * * Foreign table updates have a wholerow attribute when the * relation has a row-level trigger. Note that the wholerow * attribute does not carry system columns. Foreign table * triggers miss seeing those, except that we know enough here * to set t_tableOid. Quite separately from this, the FDW may * fetch its own junk attrs to identify the row. * * Other relevant relkinds, currently limited to views, always * have a wholerow attribute. */ else if (AttributeNumberIsValid(junkfilter->jf_junkAttNo)) { datum = ExecGetJunkAttribute(slot, junkfilter->jf_junkAttNo, &isNull); /* shouldn't ever get a null result... */ if (isNull) elog(ERROR, "wholerow is NULL"); oldtupdata.t_data = DatumGetHeapTupleHeader(datum); oldtupdata.t_len = HeapTupleHeaderGetDatumLength(oldtupdata.t_data); ItemPointerSetInvalid(&(oldtupdata.t_self)); /* Historically, view triggers see invalid t_tableOid. */ oldtupdata.t_tableOid = (relkind == RELKIND_VIEW) ? InvalidOid : RelationGetRelid(resultRelInfo->ri_RelationDesc); oldtuple = &oldtupdata; } else Assert(relkind == RELKIND_FOREIGN_TABLE); } /* * apply the junkfilter if needed. */ if (operation != CMD_DELETE) slot = ExecFilterJunk(junkfilter, slot); } switch (operation) { case CMD_INSERT: /* Prepare for tuple routing if needed. */ if (proute) slot = ExecPrepareTupleRouting(node, estate, proute, resultRelInfo, slot); slot = ExecInsert(node, slot, planSlot, estate, node->canSetTag); /* Revert ExecPrepareTupleRouting's state change. */ if (proute) estate->es_result_relation_info = resultRelInfo; break; case CMD_UPDATE: slot = ExecUpdate(node, tupleid, oldtuple, slot, planSlot, &node->mt_epqstate, estate, node->canSetTag); break; case CMD_DELETE: slot = ExecDelete(node, tupleid, oldtuple, planSlot, &node->mt_epqstate, estate, true, node->canSetTag, false /* changingPart */ , NULL, NULL); break; default: elog(ERROR, "unknown operation"); break; } /* * If we got a RETURNING result, return it to caller. We'll continue * the work on next call. */ if (slot) { estate->es_result_relation_info = saved_resultRelInfo; return slot; } } /* Restore es_result_relation_info before exiting */ estate->es_result_relation_info = saved_resultRelInfo; /* * We're done, but fire AFTER STATEMENT triggers before exiting. */ fireASTriggers(node); node->mt_done = true; return NULL; } /* ---------------------------------------------------------------- * ExecInitModifyTable * ---------------------------------------------------------------- */ ModifyTableState * ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags) { ModifyTableState *mtstate; CmdType operation = node->operation; int nplans = list_length(node->plans); ResultRelInfo *saved_resultRelInfo; ResultRelInfo *resultRelInfo; Plan *subplan; ListCell *l; int i; Relation rel; bool update_tuple_routing_needed = node->partColsUpdated; /* check for unsupported flags */ Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK))); /* * create state structure */ mtstate = makeNode(ModifyTableState); mtstate->ps.plan = (Plan *) node; mtstate->ps.state = estate; mtstate->ps.ExecProcNode = ExecModifyTable; mtstate->operation = operation; mtstate->canSetTag = node->canSetTag; mtstate->mt_done = false; mtstate->mt_plans = (PlanState **) palloc0(sizeof(PlanState *) * nplans); mtstate->resultRelInfo = estate->es_result_relations + node->resultRelIndex; mtstate->mt_scans = (TupleTableSlot **) palloc0(sizeof(TupleTableSlot *) * nplans); /* If modifying a partitioned table, initialize the root table info */ if (node->rootResultRelIndex >= 0) mtstate->rootResultRelInfo = estate->es_root_result_relations + node->rootResultRelIndex; mtstate->mt_arowmarks = (List **) palloc0(sizeof(List *) * nplans); mtstate->mt_nplans = nplans; /* set up epqstate with dummy subplan data for the moment */ EvalPlanQualInit(&mtstate->mt_epqstate, estate, NULL, NIL, node->epqParam); mtstate->fireBSTriggers = true; /* * call ExecInitNode on each of the plans to be executed and save the * results into the array "mt_plans". This is also a convenient place to * verify that the proposed target relations are valid and open their * indexes for insertion of new index entries. Note we *must* set * estate->es_result_relation_info correctly while we initialize each * sub-plan; ExecContextForcesOids depends on that! */ saved_resultRelInfo = estate->es_result_relation_info; resultRelInfo = mtstate->resultRelInfo; i = 0; foreach(l, node->plans) { subplan = (Plan *) lfirst(l); /* Initialize the usesFdwDirectModify flag */ resultRelInfo->ri_usesFdwDirectModify = bms_is_member(i, node->fdwDirectModifyPlans); /* * Verify result relation is a valid target for the current operation */ CheckValidResultRel(resultRelInfo, operation); /* * If there are indices on the result relation, open them and save * descriptors in the result relation info, so that we can add new * index entries for the tuples we add/update. We need not do this * for a DELETE, however, since deletion doesn't affect indexes. Also, * inside an EvalPlanQual operation, the indexes might be open * already, since we share the resultrel state with the original * query. */ if (resultRelInfo->ri_RelationDesc->rd_rel->relhasindex && operation != CMD_DELETE && resultRelInfo->ri_IndexRelationDescs == NULL) ExecOpenIndices(resultRelInfo, node->onConflictAction != ONCONFLICT_NONE); /* * If this is an UPDATE and a BEFORE UPDATE trigger is present, the * trigger itself might modify the partition-key values. So arrange * for tuple routing. */ if (resultRelInfo->ri_TrigDesc && resultRelInfo->ri_TrigDesc->trig_update_before_row && operation == CMD_UPDATE) update_tuple_routing_needed = true; /* Now init the plan for this result rel */ estate->es_result_relation_info = resultRelInfo; mtstate->mt_plans[i] = ExecInitNode(subplan, estate, eflags); mtstate->mt_scans[i] = ExecInitExtraTupleSlot(mtstate->ps.state, ExecGetResultType(mtstate->mt_plans[i]), &TTSOpsHeapTuple); /* Also let FDWs init themselves for foreign-table result rels */ if (!resultRelInfo->ri_usesFdwDirectModify && resultRelInfo->ri_FdwRoutine != NULL && resultRelInfo->ri_FdwRoutine->BeginForeignModify != NULL) { List *fdw_private = (List *) list_nth(node->fdwPrivLists, i); resultRelInfo->ri_FdwRoutine->BeginForeignModify(mtstate, resultRelInfo, fdw_private, i, eflags); } resultRelInfo++; i++; } estate->es_result_relation_info = saved_resultRelInfo; /* Get the target relation */ rel = (getTargetResultRelInfo(mtstate))->ri_RelationDesc; /* * If it's not a partitioned table after all, UPDATE tuple routing should * not be attempted. */ if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) update_tuple_routing_needed = false; /* * Build state for tuple routing if it's an INSERT or if it's an UPDATE of * partition key. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && (operation == CMD_INSERT || update_tuple_routing_needed)) mtstate->mt_partition_tuple_routing = ExecSetupPartitionTupleRouting(mtstate, rel); /* * Build state for collecting transition tuples. This requires having a * valid trigger query context, so skip it in explain-only mode. */ if (!(eflags & EXEC_FLAG_EXPLAIN_ONLY)) ExecSetupTransitionCaptureState(mtstate, estate); /* * Construct mapping from each of the per-subplan partition attnos to the * root attno. This is required when during update row movement the tuple * descriptor of a source partition does not match the root partitioned * table descriptor. In such a case we need to convert tuples to the root * tuple descriptor, because the search for destination partition starts * from the root. We'll also need a slot to store these converted tuples. * We can skip this setup if it's not a partition key update. */ if (update_tuple_routing_needed) { ExecSetupChildParentMapForSubplan(mtstate); mtstate->mt_root_tuple_slot = MakeTupleTableSlot(RelationGetDescr(rel), &TTSOpsHeapTuple); } /* * Initialize any WITH CHECK OPTION constraints if needed. */ resultRelInfo = mtstate->resultRelInfo; i = 0; foreach(l, node->withCheckOptionLists) { List *wcoList = (List *) lfirst(l); List *wcoExprs = NIL; ListCell *ll; foreach(ll, wcoList) { WithCheckOption *wco = (WithCheckOption *) lfirst(ll); ExprState *wcoExpr = ExecInitQual((List *) wco->qual, &mtstate->ps); wcoExprs = lappend(wcoExprs, wcoExpr); } resultRelInfo->ri_WithCheckOptions = wcoList; resultRelInfo->ri_WithCheckOptionExprs = wcoExprs; resultRelInfo++; i++; } /* * Initialize RETURNING projections if needed. */ if (node->returningLists) { TupleTableSlot *slot; ExprContext *econtext; /* * Initialize result tuple slot and assign its rowtype using the first * RETURNING list. We assume the rest will look the same. */ mtstate->ps.plan->targetlist = (List *) linitial(node->returningLists); /* Set up a slot for the output of the RETURNING projection(s) */ ExecInitResultTupleSlotTL(&mtstate->ps, &TTSOpsVirtual); slot = mtstate->ps.ps_ResultTupleSlot; /* Need an econtext too */ if (mtstate->ps.ps_ExprContext == NULL) ExecAssignExprContext(estate, &mtstate->ps); econtext = mtstate->ps.ps_ExprContext; /* * Build a projection for each result rel. */ resultRelInfo = mtstate->resultRelInfo; foreach(l, node->returningLists) { List *rlist = (List *) lfirst(l); resultRelInfo->ri_returningList = rlist; resultRelInfo->ri_projectReturning = ExecBuildProjectionInfo(rlist, econtext, slot, &mtstate->ps, resultRelInfo->ri_RelationDesc->rd_att); resultRelInfo++; } } else { /* * We still must construct a dummy result tuple type, because InitPlan * expects one (maybe should change that?). */ mtstate->ps.plan->targetlist = NIL; ExecInitResultTypeTL(&mtstate->ps); mtstate->ps.ps_ExprContext = NULL; } /* Set the list of arbiter indexes if needed for ON CONFLICT */ resultRelInfo = mtstate->resultRelInfo; if (node->onConflictAction != ONCONFLICT_NONE) resultRelInfo->ri_onConflictArbiterIndexes = node->arbiterIndexes; /* * If needed, Initialize target list, projection and qual for ON CONFLICT * DO UPDATE. */ if (node->onConflictAction == ONCONFLICT_UPDATE) { ExprContext *econtext; TupleDesc relationDesc; TupleDesc tupDesc; /* insert may only have one plan, inheritance is not expanded */ Assert(nplans == 1); /* already exists if created by RETURNING processing above */ if (mtstate->ps.ps_ExprContext == NULL) ExecAssignExprContext(estate, &mtstate->ps); econtext = mtstate->ps.ps_ExprContext; relationDesc = resultRelInfo->ri_RelationDesc->rd_att; /* * Initialize slot for the existing tuple. If we'll be performing * tuple routing, the tuple descriptor to use for this will be * determined based on which relation the update is actually applied * to, so we don't set its tuple descriptor here. */ mtstate->mt_existing = ExecInitExtraTupleSlot(mtstate->ps.state, mtstate->mt_partition_tuple_routing ? NULL : relationDesc, &TTSOpsBufferHeapTuple); /* carried forward solely for the benefit of explain */ mtstate->mt_excludedtlist = node->exclRelTlist; /* create state for DO UPDATE SET operation */ resultRelInfo->ri_onConflict = makeNode(OnConflictSetState); /* * Create the tuple slot for the UPDATE SET projection. * * Just like mt_existing above, we leave it without a tuple descriptor * in the case of partitioning tuple routing, so that it can be * changed by ExecPrepareTupleRouting. In that case, we still save * the tupdesc in the parent's state: it can be reused by partitions * with an identical descriptor to the parent. */ tupDesc = ExecTypeFromTL((List *) node->onConflictSet); mtstate->mt_conflproj = ExecInitExtraTupleSlot(mtstate->ps.state, mtstate->mt_partition_tuple_routing ? NULL : tupDesc, &TTSOpsHeapTuple); resultRelInfo->ri_onConflict->oc_ProjTupdesc = tupDesc; /* build UPDATE SET projection state */ resultRelInfo->ri_onConflict->oc_ProjInfo = ExecBuildProjectionInfo(node->onConflictSet, econtext, mtstate->mt_conflproj, &mtstate->ps, relationDesc); /* initialize state to evaluate the WHERE clause, if any */ if (node->onConflictWhere) { ExprState *qualexpr; qualexpr = ExecInitQual((List *) node->onConflictWhere, &mtstate->ps); resultRelInfo->ri_onConflict->oc_WhereClause = qualexpr; } } /* * If we have any secondary relations in an UPDATE or DELETE, they need to * be treated like non-locked relations in SELECT FOR UPDATE, ie, the * EvalPlanQual mechanism needs to be told about them. Locate the * relevant ExecRowMarks. */ foreach(l, node->rowMarks) { PlanRowMark *rc = lfirst_node(PlanRowMark, l); ExecRowMark *erm; /* ignore "parent" rowmarks; they are irrelevant at runtime */ if (rc->isParent) continue; /* find ExecRowMark (same for all subplans) */ erm = ExecFindRowMark(estate, rc->rti, false); /* build ExecAuxRowMark for each subplan */ for (i = 0; i < nplans; i++) { ExecAuxRowMark *aerm; subplan = mtstate->mt_plans[i]->plan; aerm = ExecBuildAuxRowMark(erm, subplan->targetlist); mtstate->mt_arowmarks[i] = lappend(mtstate->mt_arowmarks[i], aerm); } } /* select first subplan */ mtstate->mt_whichplan = 0; subplan = (Plan *) linitial(node->plans); EvalPlanQualSetPlan(&mtstate->mt_epqstate, subplan, mtstate->mt_arowmarks[0]); /* * Initialize the junk filter(s) if needed. INSERT queries need a filter * if there are any junk attrs in the tlist. UPDATE and DELETE always * need a filter, since there's always at least one junk attribute present * --- no need to look first. Typically, this will be a 'ctid' or * 'wholerow' attribute, but in the case of a foreign data wrapper it * might be a set of junk attributes sufficient to identify the remote * row. * * If there are multiple result relations, each one needs its own junk * filter. Note multiple rels are only possible for UPDATE/DELETE, so we * can't be fooled by some needing a filter and some not. * * This section of code is also a convenient place to verify that the * output of an INSERT or UPDATE matches the target table(s). */ { bool junk_filter_needed = false; switch (operation) { case CMD_INSERT: foreach(l, subplan->targetlist) { TargetEntry *tle = (TargetEntry *) lfirst(l); if (tle->resjunk) { junk_filter_needed = true; break; } } break; case CMD_UPDATE: case CMD_DELETE: junk_filter_needed = true; break; default: elog(ERROR, "unknown operation"); break; } if (junk_filter_needed) { resultRelInfo = mtstate->resultRelInfo; for (i = 0; i < nplans; i++) { JunkFilter *j; subplan = mtstate->mt_plans[i]->plan; if (operation == CMD_INSERT || operation == CMD_UPDATE) ExecCheckPlanOutput(resultRelInfo->ri_RelationDesc, subplan->targetlist); j = ExecInitJunkFilter(subplan->targetlist, ExecInitExtraTupleSlot(estate, NULL, &TTSOpsHeapTuple)); if (operation == CMD_UPDATE || operation == CMD_DELETE) { /* For UPDATE/DELETE, find the appropriate junk attr now */ char relkind; relkind = resultRelInfo->ri_RelationDesc->rd_rel->relkind; if (relkind == RELKIND_RELATION || relkind == RELKIND_MATVIEW || relkind == RELKIND_PARTITIONED_TABLE) { j->jf_junkAttNo = ExecFindJunkAttribute(j, "ctid"); if (!AttributeNumberIsValid(j->jf_junkAttNo)) elog(ERROR, "could not find junk ctid column"); } else if (relkind == RELKIND_FOREIGN_TABLE) { /* * When there is a row-level trigger, there should be * a wholerow attribute. */ j->jf_junkAttNo = ExecFindJunkAttribute(j, "wholerow"); } else { j->jf_junkAttNo = ExecFindJunkAttribute(j, "wholerow"); if (!AttributeNumberIsValid(j->jf_junkAttNo)) elog(ERROR, "could not find junk wholerow column"); } } resultRelInfo->ri_junkFilter = j; resultRelInfo++; } } else { if (operation == CMD_INSERT) ExecCheckPlanOutput(mtstate->resultRelInfo->ri_RelationDesc, subplan->targetlist); } } /* * Lastly, if this is not the primary (canSetTag) ModifyTable node, add it * to estate->es_auxmodifytables so that it will be run to completion by * ExecPostprocessPlan. (It'd actually work fine to add the primary * ModifyTable node too, but there's no need.) Note the use of lcons not * lappend: we need later-initialized ModifyTable nodes to be shut down * before earlier ones. This ensures that we don't throw away RETURNING * rows that need to be seen by a later CTE subplan. */ if (!mtstate->canSetTag) estate->es_auxmodifytables = lcons(mtstate, estate->es_auxmodifytables); return mtstate; } /* ---------------------------------------------------------------- * ExecEndModifyTable * * Shuts down the plan. * * Returns nothing of interest. * ---------------------------------------------------------------- */ void ExecEndModifyTable(ModifyTableState *node) { int i; /* * Allow any FDWs to shut down */ for (i = 0; i < node->mt_nplans; i++) { ResultRelInfo *resultRelInfo = node->resultRelInfo + i; if (!resultRelInfo->ri_usesFdwDirectModify && resultRelInfo->ri_FdwRoutine != NULL && resultRelInfo->ri_FdwRoutine->EndForeignModify != NULL) resultRelInfo->ri_FdwRoutine->EndForeignModify(node->ps.state, resultRelInfo); } /* * Close all the partitioned tables, leaf partitions, and their indices * and release the slot used for tuple routing, if set. */ if (node->mt_partition_tuple_routing) { ExecCleanupTupleRouting(node, node->mt_partition_tuple_routing); if (node->mt_root_tuple_slot) ExecDropSingleTupleTableSlot(node->mt_root_tuple_slot); } /* * Free the exprcontext */ ExecFreeExprContext(&node->ps); /* * clean out the tuple table */ if (node->ps.ps_ResultTupleSlot) ExecClearTuple(node->ps.ps_ResultTupleSlot); /* * Terminate EPQ execution if active */ EvalPlanQualEnd(&node->mt_epqstate); /* * shut down subplans */ for (i = 0; i < node->mt_nplans; i++) ExecEndNode(node->mt_plans[i]); } void ExecReScanModifyTable(ModifyTableState *node) { /* * Currently, we don't need to support rescan on ModifyTable nodes. The * semantics of that would be a bit debatable anyway. */ elog(ERROR, "ExecReScanModifyTable is not implemented"); }