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eab6b8b27eba54b8fd0ad3f64989d12200979c96
postgres/src/include/executor/executor.h
T
Tom Lane eab6b8b27e Turn the rangetable used by the executor into a flat list, and avoid storing 
useless substructure for its RangeTblEntry nodes.  (I chose to keep using the
same struct node type and just zero out the link fields for unneeded info,
rather than making a separate ExecRangeTblEntry type --- it seemed too
fragile to have two different rangetable representations.)

Along the way, put subplans into a list in the toplevel PlannedStmt node,
and have SubPlan nodes refer to them by list index instead of direct pointers.
Vadim wanted to do that years ago, but I never understood what he was on about
until now.  It makes things a *whole* lot more robust, because we can stop
worrying about duplicate processing of subplans during expression tree
traversals.  That's been a constant source of bugs, and it's finally gone.

There are some consequent simplifications yet to be made, like not using
a separate EState for subplans in the executor, but I'll tackle that later.
2007-02-22 22:00:26 +00:00

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/*-------------------------------------------------------------------------
*
* 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 1.138 2007/02/22 22:00:25 tgl 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 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 void ExecEndPlan(PlanState *planstate, EState *estate);
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 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 SubPlanState *ExecInitExprInitPlan(SubPlan *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 EState *CreateSubExecutorState(EState *parent_estate);
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 */
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