/*------------------------------------------------------------------------- * * execProcnode.c * contains dispatch functions which call the appropriate "initialize", * "get a tuple", and "cleanup" routines for the given node type. * If the node has children, then it will presumably call ExecInitNode, * ExecProcNode, or ExecEndNode on its subnodes and do the appropriate * processing. * * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * $PostgreSQL: pgsql/src/backend/executor/execProcnode.c,v 1.70 2010/01/02 16:57:41 momjian Exp $ * *------------------------------------------------------------------------- */ /* * INTERFACE ROUTINES * ExecInitNode - initialize a plan node and its subplans * ExecProcNode - get a tuple by executing the plan node * ExecEndNode - shut down a plan node and its subplans * * NOTES * This used to be three files. It is now all combined into * one file so that it is easier to keep ExecInitNode, ExecProcNode, * and ExecEndNode in sync when new nodes are added. * * EXAMPLE * Suppose we want the age of the manager of the shoe department and * the number of employees in that department. So we have the query: * * select DEPT.no_emps, EMP.age * where EMP.name = DEPT.mgr and * DEPT.name = "shoe" * * Suppose the planner gives us the following plan: * * Nest Loop (DEPT.mgr = EMP.name) * / \ * / \ * Seq Scan Seq Scan * DEPT EMP * (name = "shoe") * * ExecutorStart() is called first. * It calls InitPlan() which calls ExecInitNode() on * the root of the plan -- the nest loop node. * * * ExecInitNode() notices that it is looking at a nest loop and * as the code below demonstrates, it calls ExecInitNestLoop(). * Eventually this calls ExecInitNode() on the right and left subplans * and so forth until the entire plan is initialized. The result * of ExecInitNode() is a plan state tree built with the same structure * as the underlying plan tree. * * * Then when ExecRun() is called, it calls ExecutePlan() which calls * ExecProcNode() repeatedly on the top node of the plan state tree. * Each time this happens, ExecProcNode() will end up calling * ExecNestLoop(), which calls ExecProcNode() on its subplans. * Each of these subplans is a sequential scan so ExecSeqScan() is * called. The slots returned by ExecSeqScan() may contain * tuples which contain the attributes ExecNestLoop() uses to * form the tuples it returns. * * * Eventually ExecSeqScan() stops returning tuples and the nest * loop join ends. Lastly, ExecEnd() calls ExecEndNode() which * calls ExecEndNestLoop() which in turn calls ExecEndNode() on * its subplans which result in ExecEndSeqScan(). * * This should show how the executor works by having * ExecInitNode(), ExecProcNode() and ExecEndNode() dispatch * their work to the appopriate node support routines which may * in turn call these routines themselves on their subplans. */ #include "postgres.h" #include "executor/executor.h" #include "executor/instrument.h" #include "executor/nodeAgg.h" #include "executor/nodeAppend.h" #include "executor/nodeBitmapAnd.h" #include "executor/nodeBitmapHeapscan.h" #include "executor/nodeBitmapIndexscan.h" #include "executor/nodeBitmapOr.h" #include "executor/nodeCtescan.h" #include "executor/nodeFunctionscan.h" #include "executor/nodeGroup.h" #include "executor/nodeHash.h" #include "executor/nodeHashjoin.h" #include "executor/nodeIndexscan.h" #include "executor/nodeLimit.h" #include "executor/nodeLockRows.h" #include "executor/nodeMaterial.h" #include "executor/nodeMergejoin.h" #include "executor/nodeModifyTable.h" #include "executor/nodeNestloop.h" #include "executor/nodeRecursiveunion.h" #include "executor/nodeResult.h" #include "executor/nodeSeqscan.h" #include "executor/nodeSetOp.h" #include "executor/nodeSort.h" #include "executor/nodeSubplan.h" #include "executor/nodeSubqueryscan.h" #include "executor/nodeTidscan.h" #include "executor/nodeUnique.h" #include "executor/nodeValuesscan.h" #include "executor/nodeWindowAgg.h" #include "executor/nodeWorktablescan.h" #include "miscadmin.h" /* ------------------------------------------------------------------------ * ExecInitNode * * Recursively initializes all the nodes in the plan tree rooted * at 'node'. * * Inputs: * 'node' is the current node of the plan produced by the query planner * 'estate' is the shared execution state for the plan tree * 'eflags' is a bitwise OR of flag bits described in executor.h * * Returns a PlanState node corresponding to the given Plan node. * ------------------------------------------------------------------------ */ PlanState * ExecInitNode(Plan *node, EState *estate, int eflags) { PlanState *result; List *subps; ListCell *l; /* * do nothing when we get to the end of a leaf on tree. */ if (node == NULL) return NULL; switch (nodeTag(node)) { /* * control nodes */ case T_Result: result = (PlanState *) ExecInitResult((Result *) node, estate, eflags); break; case T_ModifyTable: result = (PlanState *) ExecInitModifyTable((ModifyTable *) node, estate, eflags); break; case T_Append: result = (PlanState *) ExecInitAppend((Append *) node, estate, eflags); break; case T_RecursiveUnion: result = (PlanState *) ExecInitRecursiveUnion((RecursiveUnion *) node, estate, eflags); break; case T_BitmapAnd: result = (PlanState *) ExecInitBitmapAnd((BitmapAnd *) node, estate, eflags); break; case T_BitmapOr: result = (PlanState *) ExecInitBitmapOr((BitmapOr *) node, estate, eflags); break; /* * scan nodes */ case T_SeqScan: result = (PlanState *) ExecInitSeqScan((SeqScan *) node, estate, eflags); break; case T_IndexScan: result = (PlanState *) ExecInitIndexScan((IndexScan *) node, estate, eflags); break; case T_BitmapIndexScan: result = (PlanState *) ExecInitBitmapIndexScan((BitmapIndexScan *) node, estate, eflags); break; case T_BitmapHeapScan: result = (PlanState *) ExecInitBitmapHeapScan((BitmapHeapScan *) node, estate, eflags); break; case T_TidScan: result = (PlanState *) ExecInitTidScan((TidScan *) node, estate, eflags); break; case T_SubqueryScan: result = (PlanState *) ExecInitSubqueryScan((SubqueryScan *) node, estate, eflags); break; case T_FunctionScan: result = (PlanState *) ExecInitFunctionScan((FunctionScan *) node, estate, eflags); break; case T_ValuesScan: result = (PlanState *) ExecInitValuesScan((ValuesScan *) node, estate, eflags); break; case T_CteScan: result = (PlanState *) ExecInitCteScan((CteScan *) node, estate, eflags); break; case T_WorkTableScan: result = (PlanState *) ExecInitWorkTableScan((WorkTableScan *) node, estate, eflags); break; /* * join nodes */ case T_NestLoop: result = (PlanState *) ExecInitNestLoop((NestLoop *) node, estate, eflags); break; case T_MergeJoin: result = (PlanState *) ExecInitMergeJoin((MergeJoin *) node, estate, eflags); break; case T_HashJoin: result = (PlanState *) ExecInitHashJoin((HashJoin *) node, estate, eflags); break; /* * materialization nodes */ case T_Material: result = (PlanState *) ExecInitMaterial((Material *) node, estate, eflags); break; case T_Sort: result = (PlanState *) ExecInitSort((Sort *) node, estate, eflags); break; case T_Group: result = (PlanState *) ExecInitGroup((Group *) node, estate, eflags); break; case T_Agg: result = (PlanState *) ExecInitAgg((Agg *) node, estate, eflags); break; case T_WindowAgg: result = (PlanState *) ExecInitWindowAgg((WindowAgg *) node, estate, eflags); break; case T_Unique: result = (PlanState *) ExecInitUnique((Unique *) node, estate, eflags); break; case T_Hash: result = (PlanState *) ExecInitHash((Hash *) node, estate, eflags); break; case T_SetOp: result = (PlanState *) ExecInitSetOp((SetOp *) node, estate, eflags); break; case T_LockRows: result = (PlanState *) ExecInitLockRows((LockRows *) node, estate, eflags); break; case T_Limit: result = (PlanState *) ExecInitLimit((Limit *) node, estate, eflags); break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node)); result = NULL; /* keep compiler quiet */ break; } /* * Initialize any initPlans present in this node. The planner put them in * a separate list for us. */ subps = NIL; foreach(l, node->initPlan) { SubPlan *subplan = (SubPlan *) lfirst(l); SubPlanState *sstate; Assert(IsA(subplan, SubPlan)); sstate = ExecInitSubPlan(subplan, result); subps = lappend(subps, sstate); } result->initPlan = subps; /* Set up instrumentation for this node if requested */ if (estate->es_instrument) result->instrument = InstrAlloc(1, estate->es_instrument); return result; } /* ---------------------------------------------------------------- * ExecProcNode * * Execute the given node to return a(nother) tuple. * ---------------------------------------------------------------- */ TupleTableSlot * ExecProcNode(PlanState *node) { TupleTableSlot *result; CHECK_FOR_INTERRUPTS(); if (node->chgParam != NULL) /* something changed */ ExecReScan(node, NULL); /* let ReScan handle this */ if (node->instrument) InstrStartNode(node->instrument); switch (nodeTag(node)) { /* * control nodes */ case T_ResultState: result = ExecResult((ResultState *) node); break; case T_ModifyTableState: result = ExecModifyTable((ModifyTableState *) node); break; case T_AppendState: result = ExecAppend((AppendState *) node); break; case T_RecursiveUnionState: result = ExecRecursiveUnion((RecursiveUnionState *) node); break; /* BitmapAndState does not yield tuples */ /* BitmapOrState does not yield tuples */ /* * scan nodes */ case T_SeqScanState: result = ExecSeqScan((SeqScanState *) node); break; case T_IndexScanState: result = ExecIndexScan((IndexScanState *) node); break; /* BitmapIndexScanState does not yield tuples */ case T_BitmapHeapScanState: result = ExecBitmapHeapScan((BitmapHeapScanState *) node); break; case T_TidScanState: result = ExecTidScan((TidScanState *) node); break; case T_SubqueryScanState: result = ExecSubqueryScan((SubqueryScanState *) node); break; case T_FunctionScanState: result = ExecFunctionScan((FunctionScanState *) node); break; case T_ValuesScanState: result = ExecValuesScan((ValuesScanState *) node); break; case T_CteScanState: result = ExecCteScan((CteScanState *) node); break; case T_WorkTableScanState: result = ExecWorkTableScan((WorkTableScanState *) node); break; /* * join nodes */ case T_NestLoopState: result = ExecNestLoop((NestLoopState *) node); break; case T_MergeJoinState: result = ExecMergeJoin((MergeJoinState *) node); break; case T_HashJoinState: result = ExecHashJoin((HashJoinState *) node); break; /* * materialization nodes */ case T_MaterialState: result = ExecMaterial((MaterialState *) node); break; case T_SortState: result = ExecSort((SortState *) node); break; case T_GroupState: result = ExecGroup((GroupState *) node); break; case T_AggState: result = ExecAgg((AggState *) node); break; case T_WindowAggState: result = ExecWindowAgg((WindowAggState *) node); break; case T_UniqueState: result = ExecUnique((UniqueState *) node); break; case T_HashState: result = ExecHash((HashState *) node); break; case T_SetOpState: result = ExecSetOp((SetOpState *) node); break; case T_LockRowsState: result = ExecLockRows((LockRowsState *) node); break; case T_LimitState: result = ExecLimit((LimitState *) node); break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node)); result = NULL; break; } if (node->instrument) InstrStopNode(node->instrument, TupIsNull(result) ? 0.0 : 1.0); return result; } /* ---------------------------------------------------------------- * MultiExecProcNode * * Execute a node that doesn't return individual tuples * (it might return a hashtable, bitmap, etc). Caller should * check it got back the expected kind of Node. * * This has essentially the same responsibilities as ExecProcNode, * but it does not do InstrStartNode/InstrStopNode (mainly because * it can't tell how many returned tuples to count). Each per-node * function must provide its own instrumentation support. * ---------------------------------------------------------------- */ Node * MultiExecProcNode(PlanState *node) { Node *result; CHECK_FOR_INTERRUPTS(); if (node->chgParam != NULL) /* something changed */ ExecReScan(node, NULL); /* let ReScan handle this */ switch (nodeTag(node)) { /* * Only node types that actually support multiexec will be listed */ case T_HashState: result = MultiExecHash((HashState *) node); break; case T_BitmapIndexScanState: result = MultiExecBitmapIndexScan((BitmapIndexScanState *) node); break; case T_BitmapAndState: result = MultiExecBitmapAnd((BitmapAndState *) node); break; case T_BitmapOrState: result = MultiExecBitmapOr((BitmapOrState *) node); break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node)); result = NULL; break; } return result; } /* ---------------------------------------------------------------- * ExecEndNode * * Recursively cleans up all the nodes in the plan rooted * at 'node'. * * After this operation, the query plan will not be able to be * processed any further. This should be called only after * the query plan has been fully executed. * ---------------------------------------------------------------- */ void ExecEndNode(PlanState *node) { /* * do nothing when we get to the end of a leaf on tree. */ if (node == NULL) return; if (node->chgParam != NULL) { bms_free(node->chgParam); node->chgParam = NULL; } switch (nodeTag(node)) { /* * control nodes */ case T_ResultState: ExecEndResult((ResultState *) node); break; case T_ModifyTableState: ExecEndModifyTable((ModifyTableState *) node); break; case T_AppendState: ExecEndAppend((AppendState *) node); break; case T_RecursiveUnionState: ExecEndRecursiveUnion((RecursiveUnionState *) node); break; case T_BitmapAndState: ExecEndBitmapAnd((BitmapAndState *) node); break; case T_BitmapOrState: ExecEndBitmapOr((BitmapOrState *) node); break; /* * scan nodes */ case T_SeqScanState: ExecEndSeqScan((SeqScanState *) node); break; case T_IndexScanState: ExecEndIndexScan((IndexScanState *) node); break; case T_BitmapIndexScanState: ExecEndBitmapIndexScan((BitmapIndexScanState *) node); break; case T_BitmapHeapScanState: ExecEndBitmapHeapScan((BitmapHeapScanState *) node); break; case T_TidScanState: ExecEndTidScan((TidScanState *) node); break; case T_SubqueryScanState: ExecEndSubqueryScan((SubqueryScanState *) node); break; case T_FunctionScanState: ExecEndFunctionScan((FunctionScanState *) node); break; case T_ValuesScanState: ExecEndValuesScan((ValuesScanState *) node); break; case T_CteScanState: ExecEndCteScan((CteScanState *) node); break; case T_WorkTableScanState: ExecEndWorkTableScan((WorkTableScanState *) node); break; /* * join nodes */ case T_NestLoopState: ExecEndNestLoop((NestLoopState *) node); break; case T_MergeJoinState: ExecEndMergeJoin((MergeJoinState *) node); break; case T_HashJoinState: ExecEndHashJoin((HashJoinState *) node); break; /* * materialization nodes */ case T_MaterialState: ExecEndMaterial((MaterialState *) node); break; case T_SortState: ExecEndSort((SortState *) node); break; case T_GroupState: ExecEndGroup((GroupState *) node); break; case T_AggState: ExecEndAgg((AggState *) node); break; case T_WindowAggState: ExecEndWindowAgg((WindowAggState *) node); break; case T_UniqueState: ExecEndUnique((UniqueState *) node); break; case T_HashState: ExecEndHash((HashState *) node); break; case T_SetOpState: ExecEndSetOp((SetOpState *) node); break; case T_LockRowsState: ExecEndLockRows((LockRowsState *) node); break; case T_LimitState: ExecEndLimit((LimitState *) node); break; default: elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node)); break; } }