path: root/src/include/executor/executor.h

/*-------------------------------------------------------------------------
 *
 * executor.h
 *	  support for the POSTGRES executor module
 *
 *
 * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.143 2007/11/15 21:14:43 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#ifndef EXECUTOR_H
#define EXECUTOR_H

#include "executor/execdesc.h"
#include "nodes/parsenodes.h"


/*
 * The "eflags" argument to ExecutorStart and the various ExecInitNode
 * routines is a bitwise OR of the following flag bits, which tell the
 * called plan node what to expect.  Note that the flags will get modified
 * as they are passed down the plan tree, since an upper node may require
 * functionality in its subnode not demanded of the plan as a whole
 * (example: MergeJoin requires mark/restore capability in its inner input),
 * or an upper node may shield its input from some functionality requirement
 * (example: Materialize shields its input from needing to do backward scan).
 *
 * EXPLAIN_ONLY indicates that the plan tree is being initialized just so
 * EXPLAIN can print it out; it will not be run.  Hence, no side-effects
 * of startup should occur (such as creating a SELECT INTO target table).
 * However, error checks (such as permission checks) should be performed.
 *
 * REWIND indicates that the plan node should try to efficiently support
 * rescans without parameter changes.  (Nodes must support ExecReScan calls
 * in any case, but if this flag was not given, they are at liberty to do it
 * through complete recalculation.	Note that a parameter change forces a
 * full recalculation in any case.)
 *
 * BACKWARD indicates that the plan node must respect the es_direction flag.
 * When this is not passed, the plan node will only be run forwards.
 *
 * MARK indicates that the plan node must support Mark/Restore calls.
 * When this is not passed, no Mark/Restore will occur.
 */
#define EXEC_FLAG_EXPLAIN_ONLY	0x0001	/* EXPLAIN, no ANALYZE */
#define EXEC_FLAG_REWIND		0x0002	/* need efficient rescan */
#define EXEC_FLAG_BACKWARD		0x0004	/* need backward scan */
#define EXEC_FLAG_MARK			0x0008	/* need mark/restore */


/*
 * ExecEvalExpr was formerly a function containing a switch statement;
 * now it's just a macro invoking the function pointed to by an ExprState
 * node.  Beware of double evaluation of the ExprState argument!
 */
#define ExecEvalExpr(expr, econtext, isNull, isDone) \
	((*(expr)->evalfunc) (expr, econtext, isNull, isDone))


/*
 * prototypes from functions in execAmi.c
 */
extern void ExecReScan(PlanState *node, ExprContext *exprCtxt);
extern void ExecMarkPos(PlanState *node);
extern void ExecRestrPos(PlanState *node);
extern bool ExecSupportsMarkRestore(NodeTag plantype);
extern bool ExecSupportsBackwardScan(Plan *node);
extern bool ExecMayReturnRawTuples(PlanState *node);

/*
 * prototypes from functions in execCurrent.c
 */
extern bool execCurrentOf(CurrentOfExpr * cexpr,
			  ExprContext *econtext,
			  Oid table_oid,
			  ItemPointer current_tid);

/*
 * prototypes from functions in execGrouping.c
 */
extern bool execTuplesMatch(TupleTableSlot *slot1,
				TupleTableSlot *slot2,
				int numCols,
				AttrNumber *matchColIdx,
				FmgrInfo *eqfunctions,
				MemoryContext evalContext);
extern bool execTuplesUnequal(TupleTableSlot *slot1,
				  TupleTableSlot *slot2,
				  int numCols,
				  AttrNumber *matchColIdx,
				  FmgrInfo *eqfunctions,
				  MemoryContext evalContext);
extern FmgrInfo *execTuplesMatchPrepare(int numCols,
					   Oid *eqOperators);
extern void execTuplesHashPrepare(int numCols,
					  Oid *eqOperators,
					  FmgrInfo **eqFunctions,
					  FmgrInfo **hashFunctions);
extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
					FmgrInfo *eqfunctions,
					FmgrInfo *hashfunctions,
					int nbuckets, Size entrysize,
					MemoryContext tablecxt,
					MemoryContext tempcxt);
extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
					 TupleTableSlot *slot,
					 bool *isnew);
extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
				   TupleTableSlot *slot,
				   FmgrInfo *eqfunctions,
				   FmgrInfo *hashfunctions);

/*
 * prototypes from functions in execJunk.c
 */
extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
				   TupleTableSlot *slot);
extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
							 TupleDesc cleanTupType,
							 TupleTableSlot *slot);
extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
					  const char *attrName);
extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
					 bool *isNull);
extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
			   TupleTableSlot *slot);
extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot);


/*
 * prototypes from functions in execMain.c
 */
extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc,
			ScanDirection direction, long count);
extern void ExecutorEnd(QueryDesc *queryDesc);
extern void ExecutorRewind(QueryDesc *queryDesc);
extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
extern void ExecConstraints(ResultRelInfo *resultRelInfo,
				TupleTableSlot *slot, EState *estate);
extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti,
			 ItemPointer tid, TransactionId priorXmax, CommandId curCid);
extern PlanState *ExecGetActivePlanTree(QueryDesc *queryDesc);
extern DestReceiver *CreateIntoRelDestReceiver(void);

/*
 * prototypes from functions in execProcnode.c
 */
extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
extern TupleTableSlot *ExecProcNode(PlanState *node);
extern Node *MultiExecProcNode(PlanState *node);
extern int	ExecCountSlotsNode(Plan *node);
extern void ExecEndNode(PlanState *node);

/*
 * prototypes from functions in execQual.c
 */
extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
				  bool *isNull);
extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
				   bool *isNull);
extern void init_fcache(Oid foid, FuncExprState *fcache,
			MemoryContext fcacheCxt);
extern Datum ExecMakeFunctionResult(FuncExprState *fcache,
					   ExprContext *econtext,
					   bool *isNull,
					   ExprDoneCond *isDone);
extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
							ExprContext *econtext,
							TupleDesc expectedDesc,
							TupleDesc *returnDesc);
extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
						  bool *isNull, ExprDoneCond *isDone);
extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
extern int	ExecTargetListLength(List *targetlist);
extern int	ExecCleanTargetListLength(List *targetlist);
extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
			ExprDoneCond *isDone);

/*
 * prototypes from functions in execScan.c
 */
typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);

extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd);
extern void ExecAssignScanProjectionInfo(ScanState *node);

/*
 * prototypes from functions in execTuples.c
 */
extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
					  TupleDesc tupType);
extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
extern TupleDesc ExecTypeFromExprList(List *exprList);
extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);

typedef struct TupOutputState
{
	/* use "struct" here to allow forward reference */
	struct AttInMetadata *metadata;
	TupleTableSlot *slot;
	DestReceiver *dest;
} TupOutputState;

extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
						 TupleDesc tupdesc);
extern void do_tup_output(TupOutputState *tstate, char **values);
extern void do_text_output_multiline(TupOutputState *tstate, char *text);
extern void end_tup_output(TupOutputState *tstate);

/*
 * Write a single line of text given as a C string.
 *
 * Should only be used with a single-TEXT-attribute tupdesc.
 */
#define do_text_output_oneline(tstate, text_to_emit) \
	do { \
		char *values_[1]; \
		values_[0] = (text_to_emit); \
		do_tup_output(tstate, values_); \
	} while (0)


/*
 * prototypes from functions in execUtils.c
 */
extern EState *CreateExecutorState(void);
extern void FreeExecutorState(EState *estate);
extern ExprContext *CreateExprContext(EState *estate);
extern ExprContext *CreateStandaloneExprContext(void);
extern void FreeExprContext(ExprContext *econtext);
extern void ReScanExprContext(ExprContext *econtext);

#define ResetExprContext(econtext) \
	MemoryContextReset((econtext)->ecxt_per_tuple_memory)

extern ExprContext *MakePerTupleExprContext(EState *estate);

/* Get an EState's per-output-tuple exprcontext, making it if first use */
#define GetPerTupleExprContext(estate) \
	((estate)->es_per_tuple_exprcontext ? \
	 (estate)->es_per_tuple_exprcontext : \
	 MakePerTupleExprContext(estate))

#define GetPerTupleMemoryContext(estate) \
	(GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)

/* Reset an EState's per-output-tuple exprcontext, if one's been created */
#define ResetPerTupleExprContext(estate) \
	do { \
		if ((estate)->es_per_tuple_exprcontext) \
			ResetExprContext((estate)->es_per_tuple_exprcontext); \
	} while (0)

extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
extern void ExecAssignResultTypeFromTL(PlanState *planstate);
extern TupleDesc ExecGetResultType(PlanState *planstate);
extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
						ExprContext *econtext,
						TupleTableSlot *slot,
						TupleDesc inputDesc);
extern void ExecAssignProjectionInfo(PlanState *planstate,
						 TupleDesc inputDesc);
extern void ExecFreeExprContext(PlanState *planstate);
extern TupleDesc ExecGetScanType(ScanState *scanstate);
extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);

extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);

extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid);
extern void ExecCloseScanRelation(Relation scanrel);

extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
extern void ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
					  EState *estate, bool is_vacuum);

extern void RegisterExprContextCallback(ExprContext *econtext,
							ExprContextCallbackFunction function,
							Datum arg);
extern void UnregisterExprContextCallback(ExprContext *econtext,
							  ExprContextCallbackFunction function,
							  Datum arg);

#endif   /* EXECUTOR_H  */