src/include/executor/executor.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * executor.h
   4  *        support for the POSTGRES executor module
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL$
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef EXECUTOR_H
  15 #define EXECUTOR_H
  16
  17 #include "executor/execdesc.h"
  18 #include "nodes/parsenodes.h"
  19
  20
  21 /*
  22  * The "eflags" argument to ExecutorStart and the various ExecInitNode
  23  * routines is a bitwise OR of the following flag bits, which tell the
  24  * called plan node what to expect.  Note that the flags will get modified
  25  * as they are passed down the plan tree, since an upper node may require
  26  * functionality in its subnode not demanded of the plan as a whole
  27  * (example: MergeJoin requires mark/restore capability in its inner input),
  28  * or an upper node may shield its input from some functionality requirement
  29  * (example: Materialize shields its input from needing to do backward scan).
  30  *
  31  * EXPLAIN_ONLY indicates that the plan tree is being initialized just so
  32  * EXPLAIN can print it out; it will not be run.  Hence, no side-effects
  33  * of startup should occur (such as creating a SELECT INTO target table).
  34  * However, error checks (such as permission checks) should be performed.
  35  *
  36  * REWIND indicates that the plan node should try to efficiently support
  37  * rescans without parameter changes.  (Nodes must support ExecReScan calls
  38  * in any case, but if this flag was not given, they are at liberty to do it
  39  * through complete recalculation.      Note that a parameter change forces a
  40  * full recalculation in any case.)
  41  *
  42  * BACKWARD indicates that the plan node must respect the es_direction flag.
  43  * When this is not passed, the plan node will only be run forwards.
  44  *
  45  * MARK indicates that the plan node must support Mark/Restore calls.
  46  * When this is not passed, no Mark/Restore will occur.
  47  */
  48 #define EXEC_FLAG_EXPLAIN_ONLY  0x0001  /* EXPLAIN, no ANALYZE */
  49 #define EXEC_FLAG_REWIND                0x0002  /* need efficient rescan */
  50 #define EXEC_FLAG_BACKWARD              0x0004  /* need backward scan */
  51 #define EXEC_FLAG_MARK                  0x0008  /* need mark/restore */
  52
  53
  54 /*
  55  * ExecEvalExpr was formerly a function containing a switch statement;
  56  * now it's just a macro invoking the function pointed to by an ExprState
  57  * node.  Beware of double evaluation of the ExprState argument!
  58  */
  59 #define ExecEvalExpr(expr, econtext, isNull, isDone) \
  60         ((*(expr)->evalfunc) (expr, econtext, isNull, isDone))
  61
  62
  63 /* Hook for plugins to get control in ExecutorRun() */
  64 typedef TupleTableSlot *(*ExecutorRun_hook_type) (QueryDesc *queryDesc,
  65                                                                                                   ScanDirection direction,
  66                                                                                                   long count);
  67 extern PGDLLIMPORT ExecutorRun_hook_type ExecutorRun_hook;
  68
  69
  70 /*
  71  * prototypes from functions in execAmi.c
  72  */
  73 extern void ExecReScan(PlanState *node, ExprContext *exprCtxt);
  74 extern void ExecMarkPos(PlanState *node);
  75 extern void ExecRestrPos(PlanState *node);
  76 extern bool ExecSupportsMarkRestore(NodeTag plantype);
  77 extern bool ExecSupportsBackwardScan(Plan *node);
  78 extern bool ExecMayReturnRawTuples(PlanState *node);
  79
  80 /*
  81  * prototypes from functions in execCurrent.c
  82  */
  83 extern bool execCurrentOf(CurrentOfExpr *cexpr,
  84                           ExprContext *econtext,
  85                           Oid table_oid,
  86                           ItemPointer current_tid);
  87
  88 /*
  89  * prototypes from functions in execGrouping.c
  90  */
  91 extern bool execTuplesMatch(TupleTableSlot *slot1,
  92                                 TupleTableSlot *slot2,
  93                                 int numCols,
  94                                 AttrNumber *matchColIdx,
  95                                 FmgrInfo *eqfunctions,
  96                                 MemoryContext evalContext);
  97 extern bool execTuplesUnequal(TupleTableSlot *slot1,
  98                                   TupleTableSlot *slot2,
  99                                   int numCols,
 100                                   AttrNumber *matchColIdx,
 101                                   FmgrInfo *eqfunctions,
 102                                   MemoryContext evalContext);
 103 extern FmgrInfo *execTuplesMatchPrepare(int numCols,
 104                                            Oid *eqOperators);
 105 extern void execTuplesHashPrepare(int numCols,
 106                                           Oid *eqOperators,
 107                                           FmgrInfo **eqFunctions,
 108                                           FmgrInfo **hashFunctions);
 109 extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
 110                                         FmgrInfo *eqfunctions,
 111                                         FmgrInfo *hashfunctions,
 112                                         int nbuckets, Size entrysize,
 113                                         MemoryContext tablecxt,
 114                                         MemoryContext tempcxt);
 115 extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
 116                                          TupleTableSlot *slot,
 117                                          bool *isnew);
 118 extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
 119                                    TupleTableSlot *slot,
 120                                    FmgrInfo *eqfunctions,
 121                                    FmgrInfo *hashfunctions);
 122
 123 /*
 124  * prototypes from functions in execJunk.c
 125  */
 126 extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
 127                                    TupleTableSlot *slot);
 128 extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
 129                                                          TupleDesc cleanTupType,
 130                                                          TupleTableSlot *slot);
 131 extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
 132                                           const char *attrName);
 133 extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
 134                                          bool *isNull);
 135 extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
 136                            TupleTableSlot *slot);
 137 extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot);
 138
 139
 140 /*
 141  * prototypes from functions in execMain.c
 142  */
 143 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 144 extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc,
 145                         ScanDirection direction, long count);
 146 extern TupleTableSlot *standard_ExecutorRun(QueryDesc *queryDesc,
 147                         ScanDirection direction, long count);
 148 extern void ExecutorEnd(QueryDesc *queryDesc);
 149 extern void ExecutorRewind(QueryDesc *queryDesc);
 150 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 151                                   Relation resultRelationDesc,
 152                                   Index resultRelationIndex,
 153                                   CmdType operation,
 154                                   bool doInstrument);
 155 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 156 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 157 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
 158                                 TupleTableSlot *slot, EState *estate);
 159 extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti,
 160                          ItemPointer tid, TransactionId priorXmax);
 161 extern PlanState *ExecGetActivePlanTree(QueryDesc *queryDesc);
 162 extern DestReceiver *CreateIntoRelDestReceiver(void);
 163
 164 /*
 165  * prototypes from functions in execProcnode.c
 166  */
 167 extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
 168 extern TupleTableSlot *ExecProcNode(PlanState *node);
 169 extern Node *MultiExecProcNode(PlanState *node);
 170 extern int      ExecCountSlotsNode(Plan *node);
 171 extern void ExecEndNode(PlanState *node);
 172
 173 /*
 174  * prototypes from functions in execQual.c
 175  */
 176 extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
 177                                   bool *isNull);
 178 extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
 179                                    bool *isNull);
 180 extern void init_fcache(Oid foid, FuncExprState *fcache,
 181                         MemoryContext fcacheCxt);
 182 extern Datum ExecMakeFunctionResult(FuncExprState *fcache,
 183                                            ExprContext *econtext,
 184                                            bool *isNull,
 185                                            ExprDoneCond *isDone);
 186 extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
 187                                                         ExprContext *econtext,
 188                                                         TupleDesc expectedDesc,
 189                                                         TupleDesc *returnDesc);
 190 extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
 191                                                   bool *isNull, ExprDoneCond *isDone);
 192 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 193 extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 194 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 195 extern int      ExecTargetListLength(List *targetlist);
 196 extern int      ExecCleanTargetListLength(List *targetlist);
 197 extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
 198                         ExprDoneCond *isDone);
 199
 200 /*
 201  * prototypes from functions in execScan.c
 202  */
 203 typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
 204
 205 extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd);
 206 extern void ExecAssignScanProjectionInfo(ScanState *node);
 207
 208 /*
 209  * prototypes from functions in execTuples.c
 210  */
 211 extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
 212 extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
 213 extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
 214 extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
 215                                           TupleDesc tupType);
 216 extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
 217 extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
 218 extern TupleDesc ExecTypeFromExprList(List *exprList);
 219 extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
 220
 221 typedef struct TupOutputState
 222 {
 223         /* use "struct" here to allow forward reference */
 224         struct AttInMetadata *metadata;
 225         TupleTableSlot *slot;
 226         DestReceiver *dest;
 227 } TupOutputState;
 228
 229 extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
 230                                                  TupleDesc tupdesc);
 231 extern void do_tup_output(TupOutputState *tstate, char **values);
 232 extern void do_text_output_multiline(TupOutputState *tstate, char *text);
 233 extern void end_tup_output(TupOutputState *tstate);
 234
 235 /*
 236  * Write a single line of text given as a C string.
 237  *
 238  * Should only be used with a single-TEXT-attribute tupdesc.
 239  */
 240 #define do_text_output_oneline(tstate, text_to_emit) \
 241         do { \
 242                 char *values_[1]; \
 243                 values_[0] = (text_to_emit); \
 244                 do_tup_output(tstate, values_); \
 245         } while (0)
 246
 247
 248 /*
 249  * prototypes from functions in execUtils.c
 250  */
 251 extern EState *CreateExecutorState(void);
 252 extern void FreeExecutorState(EState *estate);
 253 extern ExprContext *CreateExprContext(EState *estate);
 254 extern ExprContext *CreateStandaloneExprContext(void);
 255 extern void FreeExprContext(ExprContext *econtext);
 256 extern void ReScanExprContext(ExprContext *econtext);
 257
 258 #define ResetExprContext(econtext) \
 259         MemoryContextReset((econtext)->ecxt_per_tuple_memory)
 260
 261 extern ExprContext *MakePerTupleExprContext(EState *estate);
 262
 263 /* Get an EState's per-output-tuple exprcontext, making it if first use */
 264 #define GetPerTupleExprContext(estate) \
 265         ((estate)->es_per_tuple_exprcontext ? \
 266          (estate)->es_per_tuple_exprcontext : \
 267          MakePerTupleExprContext(estate))
 268
 269 #define GetPerTupleMemoryContext(estate) \
 270         (GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
 271
 272 /* Reset an EState's per-output-tuple exprcontext, if one's been created */
 273 #define ResetPerTupleExprContext(estate) \
 274         do { \
 275                 if ((estate)->es_per_tuple_exprcontext) \
 276                         ResetExprContext((estate)->es_per_tuple_exprcontext); \
 277         } while (0)
 278
 279 extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
 280 extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
 281 extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 282 extern TupleDesc ExecGetResultType(PlanState *planstate);
 283 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
 284                                                 ExprContext *econtext,
 285                                                 TupleTableSlot *slot,
 286                                                 TupleDesc inputDesc);
 287 extern void ExecAssignProjectionInfo(PlanState *planstate,
 288                                                  TupleDesc inputDesc);
 289 extern void ExecFreeExprContext(PlanState *planstate);
 290 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 291 extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
 292 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 293
 294 extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
 295
 296 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid);
 297 extern void ExecCloseScanRelation(Relation scanrel);
 298
 299 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 300 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 301 extern void ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
 302                                           EState *estate, bool is_vacuum);
 303
 304 extern void RegisterExprContextCallback(ExprContext *econtext,
 305                                                         ExprContextCallbackFunction function,
 306                                                         Datum arg);
 307 extern void UnregisterExprContextCallback(ExprContext *econtext,
 308                                                           ExprContextCallbackFunction function,
 309                                                           Datum arg);
 310
 311 #endif   /* EXECUTOR_H  */