/*------------------------------------------------------------------------- * * execMain.c-- * top level executor interface routines * * INTERFACE ROUTINES * ExecutorStart() * ExecutorRun() * ExecutorEnd() * * The old ExecutorMain() has been replaced by ExecutorStart(), * ExecutorRun() and ExecutorEnd() * * These three procedures are the external interfaces to the executor. * In each case, the query descriptor and the execution state is required * as arguments * * ExecutorStart() must be called at the beginning of any execution of any * query plan and ExecutorEnd() should always be called at the end of * execution of a plan. * * ExecutorRun accepts 'feature' and 'count' arguments that specify whether * the plan is to be executed forwards, backwards, and for how many tuples. * * Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * $Header: /usr/local/cvsroot/pgsql/src/backend/executor/execMain.c,v 1.26 1997/09/18 20:20:29 momjian Exp $ * *------------------------------------------------------------------------- */ #include #include "postgres.h" #include "miscadmin.h" #include "executor/executor.h" #include "executor/execdefs.h" #include "executor/execdebug.h" #include "executor/nodeIndexscan.h" #include "utils/builtins.h" #include "utils/palloc.h" #include "utils/acl.h" #include "utils/syscache.h" #include "parser/parsetree.h" /* rt_fetch() */ #include "storage/bufmgr.h" #include "storage/lmgr.h" #include "storage/smgr.h" #include "commands/async.h" /* #include "access/localam.h" */ #include "optimizer/var.h" #include "access/heapam.h" #include "catalog/heap.h" #include "commands/trigger.h" /* decls for local routines only used within this module */ static void ExecCheckPerms(CmdType operation, int resultRelation, List *rangeTable, Query *parseTree); static TupleDesc InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate); static void EndPlan(Plan *plan, EState *estate); static TupleTableSlot * ExecutePlan(EState *estate, Plan *plan, Query *parseTree, CmdType operation, int numberTuples, ScanDirection direction, void (*printfunc) ()); static void ExecRetrieve(TupleTableSlot *slot, void (*printfunc) (), EState *estate); static void ExecAppend(TupleTableSlot *slot, ItemPointer tupleid, EState *estate); static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid, EState *estate); static void ExecReplace(TupleTableSlot *slot, ItemPointer tupleid, EState *estate, Query *parseTree); /* end of local decls */ #ifdef QUERY_LIMIT static int queryLimit = ALL_TUPLES; #undef ALL_TUPLES #define ALL_TUPLES queryLimit #ifdef NOT_USED int ExecutorLimit(int limit) { return queryLimit = limit; } #endif #endif /* ---------------------------------------------------------------- * ExecutorStart * * This routine must be called at the beginning of any execution of any * query plan * * returns (AttrInfo*) which describes the attributes of the tuples to * be returned by the query. * * ---------------------------------------------------------------- */ TupleDesc ExecutorStart(QueryDesc *queryDesc, EState *estate) { TupleDesc result; /* sanity checks */ Assert(queryDesc != NULL); result = InitPlan(queryDesc->operation, queryDesc->parsetree, queryDesc->plantree, estate); /* * reset buffer refcount. the current refcounts are saved and will be * restored when ExecutorEnd is called * * this makes sure that when ExecutorRun's are called recursively as for * postquel functions, the buffers pinned by one ExecutorRun will not * be unpinned by another ExecutorRun. */ BufferRefCountReset(estate->es_refcount); return result; } /* ---------------------------------------------------------------- * ExecutorRun * * This is the main routine of the executor module. It accepts * the query descriptor from the traffic cop and executes the * query plan. * * ExecutorStart must have been called already. * * the different features supported are: * EXEC_RUN: retrieve all tuples in the forward direction * EXEC_FOR: retrieve 'count' number of tuples in the forward dir * EXEC_BACK: retrieve 'count' number of tuples in the backward dir * EXEC_RETONE: return one tuple but don't 'retrieve' it * used in postquel function processing * * * ---------------------------------------------------------------- */ TupleTableSlot * ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count) { CmdType operation; Query *parseTree; Plan *plan; TupleTableSlot *result; CommandDest dest; void (*destination) (); /* ---------------- * sanity checks * ---------------- */ Assert(queryDesc != NULL); /* ---------------- * extract information from the query descriptor * and the query feature. * ---------------- */ operation = queryDesc->operation; parseTree = queryDesc->parsetree; plan = queryDesc->plantree; dest = queryDesc->dest; destination = (void (*) ()) DestToFunction(dest); estate->es_processed = 0; estate->es_lastoid = InvalidOid; #if 0 /* * It doesn't work in common case (i.g. if function has a aggregate). * Now we store parameter values before ExecutorStart. - vadim * 01/22/97 */ #ifdef INDEXSCAN_PATCH /* * If the plan is an index scan and some of the scan key are function * arguments rescan the indices after the parameter values have been * stored in the execution state. DZ - 27-8-1996 */ if ((nodeTag(plan) == T_IndexScan) && (((IndexScan *) plan)->indxstate->iss_RuntimeKeyInfo != NULL)) { ExprContext *econtext; econtext = ((IndexScan *) plan)->scan.scanstate->cstate.cs_ExprContext; ExecIndexReScan((IndexScan *) plan, econtext, plan); } #endif #endif switch (feature) { case EXEC_RUN: result = ExecutePlan(estate, plan, parseTree, operation, ALL_TUPLES, ForwardScanDirection, destination); break; case EXEC_FOR: result = ExecutePlan(estate, plan, parseTree, operation, count, ForwardScanDirection, destination); break; /* ---------------- * retrieve next n "backward" tuples * ---------------- */ case EXEC_BACK: result = ExecutePlan(estate, plan, parseTree, operation, count, BackwardScanDirection, destination); break; /* ---------------- * return one tuple but don't "retrieve" it. * (this is used by the rule manager..) -cim 9/14/89 * ---------------- */ case EXEC_RETONE: result = ExecutePlan(estate, plan, parseTree, operation, ONE_TUPLE, ForwardScanDirection, destination); break; default: result = NULL; elog(DEBUG, "ExecutorRun: Unknown feature %d", feature); break; } return result; } /* ---------------------------------------------------------------- * ExecutorEnd * * This routine must be called at the end of any execution of any * query plan * * returns (AttrInfo*) which describes the attributes of the tuples to * be returned by the query. * * ---------------------------------------------------------------- */ void ExecutorEnd(QueryDesc *queryDesc, EState *estate) { /* sanity checks */ Assert(queryDesc != NULL); EndPlan(queryDesc->plantree, estate); /* restore saved refcounts. */ BufferRefCountRestore(estate->es_refcount); } /* =============================================================== * =============================================================== static routines follow * =============================================================== * =============================================================== */ static void ExecCheckPerms(CmdType operation, int resultRelation, List *rangeTable, Query *parseTree) { int i = 1; Oid relid; HeapTuple htp; List *lp; List *qvars, *tvars; int32 ok = 1, aclcheck_result = -1; char *opstr; NameData rname; char *userName; #define CHECK(MODE) pg_aclcheck(rname.data, userName, MODE) userName = GetPgUserName(); foreach(lp, rangeTable) { RangeTblEntry *rte = lfirst(lp); relid = rte->relid; htp = SearchSysCacheTuple(RELOID, ObjectIdGetDatum(relid), 0, 0, 0); if (!HeapTupleIsValid(htp)) elog(WARN, "ExecCheckPerms: bogus RT relid: %d", relid); strNcpy(rname.data, ((Form_pg_class) GETSTRUCT(htp))->relname.data, NAMEDATALEN - 1); if (i == resultRelation) { /* this is the result relation */ qvars = pull_varnos(parseTree->qual); tvars = pull_varnos((Node *) parseTree->targetList); if (intMember(resultRelation, qvars) || intMember(resultRelation, tvars)) { /* result relation is scanned */ ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK); opstr = "read"; if (!ok) break; } switch (operation) { case CMD_INSERT: ok = ((aclcheck_result = CHECK(ACL_AP)) == ACLCHECK_OK) || ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK); opstr = "append"; break; case CMD_NOTIFY: /* what does this mean?? -- jw, * 1/6/94 */ case CMD_DELETE: case CMD_UPDATE: ok = ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK); opstr = "write"; break; default: elog(WARN, "ExecCheckPerms: bogus operation %d", operation); } } else { /* XXX NOTIFY?? */ ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK); opstr = "read"; } if (!ok) break; ++i; } if (!ok) { elog(WARN, "%s: %s", rname.data, aclcheck_error_strings[aclcheck_result]); } } /* ---------------------------------------------------------------- * InitPlan * * Initializes the query plan: open files, allocate storage * and start up the rule manager * ---------------------------------------------------------------- */ static TupleDesc InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate) { List *rangeTable; int resultRelation; Relation intoRelationDesc; TupleDesc tupType; List *targetList; int len; /* ---------------- * get information from query descriptor * ---------------- */ rangeTable = parseTree->rtable; resultRelation = parseTree->resultRelation; /* ---------------- * initialize the node's execution state * ---------------- */ estate->es_range_table = rangeTable; /* ---------------- * initialize the BaseId counter so node base_id's * are assigned correctly. Someday baseid's will have to * be stored someplace other than estate because they * should be unique per query planned. * ---------------- */ estate->es_BaseId = 1; /* ---------------- * initialize result relation stuff * ---------------- */ if (resultRelation != 0 && operation != CMD_SELECT) { /* ---------------- * if we have a result relation, open it and * initialize the result relation info stuff. * ---------------- */ RelationInfo *resultRelationInfo; Index resultRelationIndex; RangeTblEntry *rtentry; Oid resultRelationOid; Relation resultRelationDesc; resultRelationIndex = resultRelation; rtentry = rt_fetch(resultRelationIndex, rangeTable); resultRelationOid = rtentry->relid; resultRelationDesc = heap_open(resultRelationOid); if (resultRelationDesc->rd_rel->relkind == RELKIND_SEQUENCE) elog(WARN, "You can't change sequence relation %s", resultRelationDesc->rd_rel->relname.data); /* * Write-lock the result relation right away: if the relation is * used in a subsequent scan, we won't have to elevate the * read-lock set by heap_beginscan to a write-lock (needed by * heap_insert, heap_delete and heap_replace). This will hopefully * prevent some deadlocks. - 01/24/94 */ RelationSetLockForWrite(resultRelationDesc); resultRelationInfo = makeNode(RelationInfo); resultRelationInfo->ri_RangeTableIndex = resultRelationIndex; resultRelationInfo->ri_RelationDesc = resultRelationDesc; resultRelationInfo->ri_NumIndices = 0; resultRelationInfo->ri_IndexRelationDescs = NULL; resultRelationInfo->ri_IndexRelationInfo = NULL; /* ---------------- * open indices on result relation and save descriptors * in the result relation information.. * ---------------- */ ExecOpenIndices(resultRelationOid, resultRelationInfo); estate->es_result_relation_info = resultRelationInfo; } else { /* ---------------- * if no result relation, then set state appropriately * ---------------- */ estate->es_result_relation_info = NULL; } #ifndef NO_SECURITY ExecCheckPerms(operation, resultRelation, rangeTable, parseTree); #endif /* ---------------- * initialize the executor "tuple" table. * ---------------- */ { int nSlots = ExecCountSlotsNode(plan); TupleTable tupleTable = ExecCreateTupleTable(nSlots + 10); /* why add ten? - jolly */ estate->es_tupleTable = tupleTable; } /* ---------------- * initialize the private state information for * all the nodes in the query tree. This opens * files, allocates storage and leaves us ready * to start processing tuples.. * ---------------- */ ExecInitNode(plan, estate, NULL); /* ---------------- * get the tuple descriptor describing the type * of tuples to return.. (this is especially important * if we are creating a relation with "retrieve into") * ---------------- */ tupType = ExecGetTupType(plan); /* tuple descriptor */ targetList = plan->targetlist; len = ExecTargetListLength(targetList); /* number of attributes */ /* ---------------- * now that we have the target list, initialize the junk filter * if this is a REPLACE or a DELETE query. * We also init the junk filter if this is an append query * (there might be some rule lock info there...) * NOTE: in the future we might want to initialize the junk * filter for all queries. * ---------------- */ if (operation == CMD_UPDATE || operation == CMD_DELETE || operation == CMD_INSERT) { JunkFilter *j = (JunkFilter *) ExecInitJunkFilter(targetList); estate->es_junkFilter = j; } else estate->es_junkFilter = NULL; /* ---------------- * initialize the "into" relation * ---------------- */ intoRelationDesc = (Relation) NULL; if (operation == CMD_SELECT) { char *intoName; char archiveMode; Oid intoRelationId; TupleDesc tupdesc; if (!parseTree->isPortal) { /* * a select into table */ if (parseTree->into != NULL) { /* ---------------- * create the "into" relation * * note: there is currently no way for the user to * specify the desired archive mode of the * "into" relation... * ---------------- */ intoName = parseTree->into; archiveMode = 'n'; /* * have to copy tupType to get rid of constraints */ tupdesc = CreateTupleDescCopy(tupType); /* fixup to prevent zero-length columns in create */ setVarAttrLenForCreateTable(tupdesc, targetList, rangeTable); intoRelationId = heap_create(intoName, intoName, /* not used */ archiveMode, DEFAULT_SMGR, tupdesc); #ifdef NOT_USED /* it's copy ... */ resetVarAttrLenForCreateTable(tupdesc); #endif FreeTupleDesc(tupdesc); /* ---------------- * XXX rather than having to call setheapoverride(true) * and then back to false, we should change the * arguments to heap_open() instead.. * ---------------- */ setheapoverride(true); intoRelationDesc = heap_open(intoRelationId); setheapoverride(false); } } } estate->es_into_relation_descriptor = intoRelationDesc; /* ---------------- * return the type information.. * ---------------- */ /* attinfo = (AttrInfo *)palloc(sizeof(AttrInfo)); attinfo->numAttr = len; attinfo->attrs = tupType->attrs; */ return tupType; } /* ---------------------------------------------------------------- * EndPlan * * Cleans up the query plan -- closes files and free up storages * ---------------------------------------------------------------- */ static void EndPlan(Plan *plan, EState *estate) { RelationInfo *resultRelationInfo; Relation intoRelationDesc; /* ---------------- * get information from state * ---------------- */ resultRelationInfo = estate->es_result_relation_info; intoRelationDesc = estate->es_into_relation_descriptor; /* ---------------- * shut down the query * ---------------- */ ExecEndNode(plan, plan); /* ---------------- * destroy the executor "tuple" table. * ---------------- */ { TupleTable tupleTable = (TupleTable) estate->es_tupleTable; ExecDestroyTupleTable(tupleTable, true); /* was missing last arg */ estate->es_tupleTable = NULL; } /* ---------------- * close the result relations if necessary * ---------------- */ if (resultRelationInfo != NULL) { Relation resultRelationDesc; resultRelationDesc = resultRelationInfo->ri_RelationDesc; heap_close(resultRelationDesc); /* ---------------- * close indices on the result relation * ---------------- */ ExecCloseIndices(resultRelationInfo); } /* ---------------- * close the "into" relation if necessary * ---------------- */ if (intoRelationDesc != NULL) { heap_close(intoRelationDesc); } } /* ---------------------------------------------------------------- * ExecutePlan * * processes the query plan to retrieve 'tupleCount' tuples in the * direction specified. * Retrieves all tuples if tupleCount is 0 * * result is either a slot containing a tuple in the case * of a RETRIEVE or NULL otherwise. * * ---------------------------------------------------------------- */ /* the ctid attribute is a 'junk' attribute that is removed before the user can see it*/ static TupleTableSlot * ExecutePlan(EState *estate, Plan *plan, Query *parseTree, CmdType operation, int numberTuples, ScanDirection direction, void (*printfunc) ()) { JunkFilter *junkfilter; TupleTableSlot *slot; ItemPointer tupleid = NULL; ItemPointerData tuple_ctid; int current_tuple_count; TupleTableSlot *result; /* ---------------- * initialize local variables * ---------------- */ slot = NULL; current_tuple_count = 0; result = NULL; /* ---------------- * Set the direction. * ---------------- */ estate->es_direction = direction; /* ---------------- * Loop until we've processed the proper number * of tuples from the plan.. * ---------------- */ for (;;) { if (operation != CMD_NOTIFY) { /* ---------------- * Execute the plan and obtain a tuple * ---------------- */ /* at the top level, the parent of a plan (2nd arg) is itself */ slot = ExecProcNode(plan, plan); /* ---------------- * if the tuple is null, then we assume * there is nothing more to process so * we just return null... * ---------------- */ if (TupIsNull(slot)) { result = NULL; break; } } /* ---------------- * if we have a junk filter, then project a new * tuple with the junk removed. * * Store this new "clean" tuple in the place of the * original tuple. * * Also, extract all the junk ifnormation we need. * ---------------- */ if ((junkfilter = estate->es_junkFilter) != (JunkFilter *) NULL) { Datum datum; /* NameData attrName; */ HeapTuple newTuple; bool isNull; /* --------------- * extract the 'ctid' junk attribute. * --------------- */ if (operation == CMD_UPDATE || operation == CMD_DELETE) { if (!ExecGetJunkAttribute(junkfilter, slot, "ctid", &datum, &isNull)) elog(WARN, "ExecutePlan: NO (junk) `ctid' was found!"); if (isNull) elog(WARN, "ExecutePlan: (junk) `ctid' is NULL!"); tupleid = (ItemPointer) DatumGetPointer(datum); tuple_ctid = *tupleid; /* make sure we don't free the * ctid!! */ tupleid = &tuple_ctid; } /* --------------- * Finally create a new "clean" tuple with all junk attributes * removed * --------------- */ newTuple = ExecRemoveJunk(junkfilter, slot); slot = ExecStoreTuple(newTuple, /* tuple to store */ slot, /* destination slot */ InvalidBuffer, /* this tuple has no * buffer */ true); /* tuple should be pfreed */ } /* if (junkfilter... */ /* ---------------- * now that we have a tuple, do the appropriate thing * with it.. either return it to the user, add * it to a relation someplace, delete it from a * relation, or modify some of it's attributes. * ---------------- */ switch (operation) { case CMD_SELECT: ExecRetrieve(slot, /* slot containing tuple */ printfunc, /* print function */ estate); /* */ result = slot; break; case CMD_INSERT: ExecAppend(slot, tupleid, estate); result = NULL; break; case CMD_DELETE: ExecDelete(slot, tupleid, estate); result = NULL; break; case CMD_UPDATE: ExecReplace(slot, tupleid, estate, parseTree); result = NULL; break; /* * Total hack. I'm ignoring any accessor functions for * Relation, RelationTupleForm, NameData. Assuming that * NameData.data has offset 0. */ case CMD_NOTIFY: { RelationInfo *rInfo = estate->es_result_relation_info; Relation rDesc = rInfo->ri_RelationDesc; Async_Notify(rDesc->rd_rel->relname.data); result = NULL; current_tuple_count = 0; numberTuples = 1; elog(DEBUG, "ExecNotify %s", &rDesc->rd_rel->relname); } break; default: elog(DEBUG, "ExecutePlan: unknown operation in queryDesc"); result = NULL; break; } /* ---------------- * check our tuple count.. if we've returned the * proper number then return, else loop again and * process more tuples.. * ---------------- */ current_tuple_count += 1; if (numberTuples == current_tuple_count) break; } /* ---------------- * here, result is either a slot containing a tuple in the case * of a RETRIEVE or NULL otherwise. * ---------------- */ return result; } /* ---------------------------------------------------------------- * ExecRetrieve * * RETRIEVEs are easy.. we just pass the tuple to the appropriate * print function. The only complexity is when we do a * "retrieve into", in which case we insert the tuple into * the appropriate relation (note: this is a newly created relation * so we don't need to worry about indices or locks.) * ---------------------------------------------------------------- */ static void ExecRetrieve(TupleTableSlot *slot, void (*printfunc) (), EState *estate) { HeapTuple tuple; TupleDesc attrtype; /* ---------------- * get the heap tuple out of the tuple table slot * ---------------- */ tuple = slot->val; attrtype = slot->ttc_tupleDescriptor; /* ---------------- * insert the tuple into the "into relation" * ---------------- */ if (estate->es_into_relation_descriptor != NULL) { heap_insert(estate->es_into_relation_descriptor, tuple); IncrAppended(); } /* ---------------- * send the tuple to the front end (or the screen) * ---------------- */ (*printfunc) (tuple, attrtype); IncrRetrieved(); (estate->es_processed)++; } /* ---------------------------------------------------------------- * ExecAppend * * APPENDs are trickier.. we have to insert the tuple into * the base relation and insert appropriate tuples into the * index relations. * ---------------------------------------------------------------- */ static void ExecAppend(TupleTableSlot *slot, ItemPointer tupleid, EState *estate) { HeapTuple tuple; RelationInfo *resultRelationInfo; Relation resultRelationDesc; int numIndices; Oid newId; /* ---------------- * get the heap tuple out of the tuple table slot * ---------------- */ tuple = slot->val; /* ---------------- * get information on the result relation * ---------------- */ resultRelationInfo = estate->es_result_relation_info; resultRelationDesc = resultRelationInfo->ri_RelationDesc; /* ---------------- * have to add code to preform unique checking here. * cim -12/1/89 * ---------------- */ /* BEFORE ROW INSERT Triggers */ if (resultRelationDesc->trigdesc && resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_INSERT] > 0) { HeapTuple newtuple; newtuple = ExecBRInsertTriggers(resultRelationDesc, tuple); if (newtuple == NULL) /* "do nothing" */ return; if (newtuple != tuple) /* modified by Trigger(s) */ { Assert(slot->ttc_shouldFree); pfree(tuple); slot->val = tuple = newtuple; } } /* ---------------- * Check the constraints of a tuple * ---------------- */ if (resultRelationDesc->rd_att->constr) { HeapTuple newtuple; newtuple = ExecConstraints("ExecAppend", resultRelationDesc, tuple); if (newtuple != tuple) /* modified by DEFAULT */ { Assert(slot->ttc_shouldFree); pfree(tuple); slot->val = tuple = newtuple; } } /* ---------------- * insert the tuple * ---------------- */ newId = heap_insert(resultRelationDesc, /* relation desc */ tuple); /* heap tuple */ IncrAppended(); /* ---------------- * process indices * * Note: heap_insert adds a new tuple to a relation. As a side * effect, the tupleid of the new tuple is placed in the new * tuple's t_ctid field. * ---------------- */ numIndices = resultRelationInfo->ri_NumIndices; if (numIndices > 0) { ExecInsertIndexTuples(slot, &(tuple->t_ctid), estate, false); } (estate->es_processed)++; estate->es_lastoid = newId; /* AFTER ROW INSERT Triggers */ if (resultRelationDesc->trigdesc && resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0) ExecARInsertTriggers(resultRelationDesc, tuple); } /* ---------------------------------------------------------------- * ExecDelete * * DELETE is like append, we delete the tuple and its * index tuples. * ---------------------------------------------------------------- */ static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid, EState *estate) { RelationInfo *resultRelationInfo; Relation resultRelationDesc; /* ---------------- * get the result relation information * ---------------- */ resultRelationInfo = estate->es_result_relation_info; resultRelationDesc = resultRelationInfo->ri_RelationDesc; /* BEFORE ROW DELETE Triggers */ if (resultRelationDesc->trigdesc && resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_DELETE] > 0) { bool dodelete; dodelete = ExecBRDeleteTriggers(resultRelationDesc, tupleid); if (!dodelete) /* "do nothing" */ return; } /* ---------------- * delete the tuple * ---------------- */ if (heap_delete(resultRelationDesc, /* relation desc */ tupleid)) /* item pointer to tuple */ return; IncrDeleted(); (estate->es_processed)++; /* ---------------- * 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 the vacuum daemon automatically * opens an index scan and deletes index tuples * when it finds deleted heap tuples. -cim 9/27/89 * ---------------- */ /* AFTER ROW DELETE Triggers */ if (resultRelationDesc->trigdesc && resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_DELETE] > 0) ExecARDeleteTriggers(resultRelationDesc, tupleid); } /* ---------------------------------------------------------------- * ExecReplace * * note: we can't run replace queries with transactions * off because replaces are actually appends and our * scan will mistakenly loop forever, replacing the tuple * it just appended.. This should be fixed but until it * is, we don't want to get stuck in an infinite loop * which corrupts your database.. * ---------------------------------------------------------------- */ static void ExecReplace(TupleTableSlot *slot, ItemPointer tupleid, EState *estate, Query *parseTree) { HeapTuple tuple; RelationInfo *resultRelationInfo; Relation resultRelationDesc; int numIndices; /* ---------------- * abort the operation if not running transactions * ---------------- */ if (IsBootstrapProcessingMode()) { elog(DEBUG, "ExecReplace: replace can't run without transactions"); return; } /* ---------------- * get the heap tuple out of the tuple table slot * ---------------- */ tuple = slot->val; /* ---------------- * get the result relation information * ---------------- */ resultRelationInfo = estate->es_result_relation_info; resultRelationDesc = resultRelationInfo->ri_RelationDesc; /* ---------------- * have to add code to preform unique checking here. * in the event of unique tuples, this becomes a deletion * of the original tuple affected by the replace. * cim -12/1/89 * ---------------- */ /* BEFORE ROW UPDATE Triggers */ if (resultRelationDesc->trigdesc && resultRelationDesc->trigdesc->n_before_row[TRIGGER_EVENT_UPDATE] > 0) { HeapTuple newtuple; newtuple = ExecBRUpdateTriggers(resultRelationDesc, tupleid, tuple); if (newtuple == NULL) /* "do nothing" */ return; if (newtuple != tuple) /* modified by Trigger(s) */ { Assert(slot->ttc_shouldFree); pfree(tuple); slot->val = tuple = newtuple; } } /* ---------------- * Check the constraints of a tuple * ---------------- */ if (resultRelationDesc->rd_att->constr) { HeapTuple newtuple; newtuple = ExecConstraints("ExecReplace", resultRelationDesc, tuple); if (newtuple != tuple) /* modified by DEFAULT */ { Assert(slot->ttc_shouldFree); pfree(tuple); slot->val = tuple = newtuple; } } /* ---------------- * replace the heap tuple * * Don't want to continue if our heap_replace didn't actually * do a replace. This would be the case if heap_replace * detected a non-functional update. -kw 12/30/93 * ---------------- */ if (heap_replace(resultRelationDesc, /* relation desc */ tupleid, /* item ptr of tuple to replace */ tuple)) { /* replacement heap tuple */ return; } IncrReplaced(); (estate->es_processed)++; /* ---------------- * 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 * replaces are actually deletes and inserts and * index tuple deletion is done automagically by * the vaccuum deamon.. All we do is insert new * index tuples. -cim 9/27/89 * ---------------- */ /* ---------------- * process indices * * heap_replace updates a tuple in the base relation by invalidating * it and then appending a new tuple to the relation. As a side * effect, the tupleid of the new tuple is placed in the new * tuple's t_ctid field. So we now insert index tuples using * the new tupleid stored there. * ---------------- */ numIndices = resultRelationInfo->ri_NumIndices; if (numIndices > 0) { ExecInsertIndexTuples(slot, &(tuple->t_ctid), estate, true); } /* AFTER ROW UPDATE Triggers */ if (resultRelationDesc->trigdesc && resultRelationDesc->trigdesc->n_after_row[TRIGGER_EVENT_UPDATE] > 0) ExecARUpdateTriggers(resultRelationDesc, tupleid, tuple); } static HeapTuple ExecAttrDefault(Relation rel, HeapTuple tuple) { int ndef = rel->rd_att->constr->num_defval; AttrDefault *attrdef = rel->rd_att->constr->defval; ExprContext *econtext = makeNode(ExprContext); HeapTuple newtuple; Node *expr; bool isnull; bool isdone; Datum val; Datum *replValue = NULL; char *replNull = NULL; char *repl = NULL; int i; econtext->ecxt_scantuple = NULL; /* scan tuple slot */ econtext->ecxt_innertuple = NULL; /* inner tuple slot */ econtext->ecxt_outertuple = NULL; /* outer tuple slot */ econtext->ecxt_relation = NULL; /* relation */ econtext->ecxt_relid = 0; /* relid */ econtext->ecxt_param_list_info = NULL; /* param list info */ econtext->ecxt_range_table = NULL; /* range table */ for (i = 0; i < ndef; i++) { if (!heap_attisnull(tuple, attrdef[i].adnum)) continue; expr = (Node *) stringToNode(attrdef[i].adbin); val = ExecEvalExpr(expr, econtext, &isnull, &isdone); pfree(expr); if (isnull) continue; if (repl == NULL) { repl = (char *) palloc(rel->rd_att->natts * sizeof(char)); replNull = (char *) palloc(rel->rd_att->natts * sizeof(char)); replValue = (Datum *) palloc(rel->rd_att->natts * sizeof(Datum)); MemSet(repl, ' ', rel->rd_att->natts * sizeof(char)); } repl[attrdef[i].adnum - 1] = 'r'; replNull[attrdef[i].adnum - 1] = ' '; replValue[attrdef[i].adnum - 1] = val; } pfree(econtext); if (repl == NULL) return (tuple); newtuple = heap_modifytuple(tuple, InvalidBuffer, rel, replValue, replNull, repl); pfree(repl); pfree(replNull); pfree(replValue); return (newtuple); } static char * ExecRelCheck(Relation rel, HeapTuple tuple) { int ncheck = rel->rd_att->constr->num_check; ConstrCheck *check = rel->rd_att->constr->check; ExprContext *econtext = makeNode(ExprContext); TupleTableSlot *slot = makeNode(TupleTableSlot); RangeTblEntry *rte = makeNode(RangeTblEntry); List *rtlist; List *qual; bool res; int i; slot->val = tuple; slot->ttc_shouldFree = false; slot->ttc_descIsNew = true; slot->ttc_tupleDescriptor = rel->rd_att; slot->ttc_buffer = InvalidBuffer; slot->ttc_whichplan = -1; rte->relname = nameout(&(rel->rd_rel->relname)); rte->timeRange = NULL; rte->refname = rte->relname; rte->relid = rel->rd_id; rte->inh = false; rte->archive = false; rte->inFromCl = true; rte->timeQual = NULL; rtlist = lcons(rte, NIL); econtext->ecxt_scantuple = slot; /* scan tuple slot */ econtext->ecxt_innertuple = NULL; /* inner tuple slot */ econtext->ecxt_outertuple = NULL; /* outer tuple slot */ econtext->ecxt_relation = rel; /* relation */ econtext->ecxt_relid = 0; /* relid */ econtext->ecxt_param_list_info = NULL; /* param list info */ econtext->ecxt_range_table = rtlist; /* range table */ for (i = 0; i < ncheck; i++) { qual = (List *) stringToNode(check[i].ccbin); res = ExecQual(qual, econtext); pfree(qual); if (!res) return (check[i].ccname); } pfree(slot); pfree(rte->relname); pfree(rte); pfree(rtlist); pfree(econtext); return ((char *) NULL); } HeapTuple ExecConstraints(char *caller, Relation rel, HeapTuple tuple) { HeapTuple newtuple = tuple; Assert(rel->rd_att->constr); if (rel->rd_att->constr->num_defval > 0) newtuple = tuple = ExecAttrDefault(rel, tuple); if (rel->rd_att->constr->has_not_null) { int attrChk; for (attrChk = 1; attrChk <= rel->rd_att->natts; attrChk++) { if (rel->rd_att->attrs[attrChk - 1]->attnotnull && heap_attisnull(tuple, attrChk)) elog(WARN, "%s: Fail to add null value in not null attribute %s", caller, rel->rd_att->attrs[attrChk - 1]->attname.data); } } if (rel->rd_att->constr->num_check > 0) { char *failed; if ((failed = ExecRelCheck(rel, tuple)) != NULL) elog(WARN, "%s: rejected due to CHECK constraint %s", caller, failed); } return (newtuple); }