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
  79 /*
  80  * prototypes from functions in execCurrent.c
  81  */
  82 extern bool execCurrentOf(CurrentOfExpr *cexpr,
  83                           ExprContext *econtext,
  84                           Oid table_oid,
  85                           ItemPointer current_tid);
  86
  87 /*
  88  * prototypes from functions in execGrouping.c
  89  */
  90 extern bool execTuplesMatch(TupleTableSlot *slot1,
  91                                 TupleTableSlot *slot2,
  92                                 int numCols,
  93                                 AttrNumber *matchColIdx,
  94                                 FmgrInfo *eqfunctions,
  95                                 MemoryContext evalContext);
  96 extern bool execTuplesUnequal(TupleTableSlot *slot1,
  97                                   TupleTableSlot *slot2,
  98                                   int numCols,
  99                                   AttrNumber *matchColIdx,
 100                                   FmgrInfo *eqfunctions,
 101                                   MemoryContext evalContext);
 102 extern FmgrInfo *execTuplesMatchPrepare(int numCols,
 103                                            Oid *eqOperators);
 104 extern void execTuplesHashPrepare(int numCols,
 105                                           Oid *eqOperators,
 106                                           FmgrInfo **eqFunctions,
 107                                           FmgrInfo **hashFunctions);
 108 extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
 109                                         FmgrInfo *eqfunctions,
 110                                         FmgrInfo *hashfunctions,
 111                                         int nbuckets, Size entrysize,
 112                                         MemoryContext tablecxt,
 113                                         MemoryContext tempcxt);
 114 extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
 115                                          TupleTableSlot *slot,
 116                                          bool *isnew);
 117 extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
 118                                    TupleTableSlot *slot,
 119                                    FmgrInfo *eqfunctions,
 120                                    FmgrInfo *hashfunctions);
 121
 122 /*
 123  * prototypes from functions in execJunk.c
 124  */
 125 extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
 126                                    TupleTableSlot *slot);
 127 extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
 128                                                          TupleDesc cleanTupType,
 129                                                          TupleTableSlot *slot);
 130 extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
 131                                           const char *attrName);
 132 extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
 133                                          bool *isNull);
 134 extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
 135                            TupleTableSlot *slot);
 136 extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot);
 137
 138
 139 /*
 140  * prototypes from functions in execMain.c
 141  */
 142 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 143 extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc,
 144                         ScanDirection direction, long count);
 145 extern TupleTableSlot *standard_ExecutorRun(QueryDesc *queryDesc,
 146                         ScanDirection direction, long count);
 147 extern void ExecutorEnd(QueryDesc *queryDesc);
 148 extern void ExecutorRewind(QueryDesc *queryDesc);
 149 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 150                                   Relation resultRelationDesc,
 151                                   Index resultRelationIndex,
 152                                   CmdType operation,
 153                                   bool doInstrument);
 154 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 155 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 156 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
 157                                 TupleTableSlot *slot, EState *estate);
 158 extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti,
 159                          ItemPointer tid, TransactionId priorXmax);
 160 extern PlanState *ExecGetActivePlanTree(QueryDesc *queryDesc);
 161 extern DestReceiver *CreateIntoRelDestReceiver(void);
 162
 163 /*
 164  * prototypes from functions in execProcnode.c
 165  */
 166 extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
 167 extern TupleTableSlot *ExecProcNode(PlanState *node);
 168 extern Node *MultiExecProcNode(PlanState *node);
 169 extern int      ExecCountSlotsNode(Plan *node);
 170 extern void ExecEndNode(PlanState *node);
 171
 172 /*
 173  * prototypes from functions in execQual.c
 174  */
 175 extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
 176                                   bool *isNull);
 177 extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
 178                                    bool *isNull);
 179 extern void init_fcache(Oid foid, FuncExprState *fcache,
 180                         MemoryContext fcacheCxt);
 181 extern Datum ExecMakeFunctionResult(FuncExprState *fcache,
 182                                            ExprContext *econtext,
 183                                            bool *isNull,
 184                                            ExprDoneCond *isDone);
 185 extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
 186                                                         ExprContext *econtext,
 187                                                         TupleDesc expectedDesc,
 188                                                         TupleDesc *returnDesc);
 189 extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
 190                                                   bool *isNull, ExprDoneCond *isDone);
 191 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 192 extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 193 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 194 extern int      ExecTargetListLength(List *targetlist);
 195 extern int      ExecCleanTargetListLength(List *targetlist);
 196 extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
 197                         ExprDoneCond *isDone);
 198
 199 /*
 200  * prototypes from functions in execScan.c
 201  */
 202 typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
 203
 204 extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd);
 205 extern void ExecAssignScanProjectionInfo(ScanState *node);
 206
 207 /*
 208  * prototypes from functions in execTuples.c
 209  */
 210 extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
 211 extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
 212 extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
 213 extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
 214                                           TupleDesc tupType);
 215 extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
 216 extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
 217 extern TupleDesc ExecTypeFromExprList(List *exprList);
 218 extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
 219
 220 typedef struct TupOutputState
 221 {
 222         /* use "struct" here to allow forward reference */
 223         struct AttInMetadata *metadata;
 224         TupleTableSlot *slot;
 225         DestReceiver *dest;
 226 } TupOutputState;
 227
 228 extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
 229                                                  TupleDesc tupdesc);
 230 extern void do_tup_output(TupOutputState *tstate, char **values);
 231 extern void do_text_output_multiline(TupOutputState *tstate, char *text);
 232 extern void end_tup_output(TupOutputState *tstate);
 233
 234 /*
 235  * Write a single line of text given as a C string.
 236  *
 237  * Should only be used with a single-TEXT-attribute tupdesc.
 238  */
 239 #define do_text_output_oneline(tstate, text_to_emit) \
 240         do { \
 241                 char *values_[1]; \
 242                 values_[0] = (text_to_emit); \
 243                 do_tup_output(tstate, values_); \
 244         } while (0)
 245
 246
 247 /*
 248  * prototypes from functions in execUtils.c
 249  */
 250 extern EState *CreateExecutorState(void);
 251 extern void FreeExecutorState(EState *estate);
 252 extern ExprContext *CreateExprContext(EState *estate);
 253 extern ExprContext *CreateStandaloneExprContext(void);
 254 extern void FreeExprContext(ExprContext *econtext);
 255 extern void ReScanExprContext(ExprContext *econtext);
 256
 257 #define ResetExprContext(econtext) \
 258         MemoryContextReset((econtext)->ecxt_per_tuple_memory)
 259
 260 extern ExprContext *MakePerTupleExprContext(EState *estate);
 261
 262 /* Get an EState's per-output-tuple exprcontext, making it if first use */
 263 #define GetPerTupleExprContext(estate) \
 264         ((estate)->es_per_tuple_exprcontext ? \
 265          (estate)->es_per_tuple_exprcontext : \
 266          MakePerTupleExprContext(estate))
 267
 268 #define GetPerTupleMemoryContext(estate) \
 269         (GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
 270
 271 /* Reset an EState's per-output-tuple exprcontext, if one's been created */
 272 #define ResetPerTupleExprContext(estate) \
 273         do { \
 274                 if ((estate)->es_per_tuple_exprcontext) \
 275                         ResetExprContext((estate)->es_per_tuple_exprcontext); \
 276         } while (0)
 277
 278 extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
 279 extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
 280 extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 281 extern TupleDesc ExecGetResultType(PlanState *planstate);
 282 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
 283                                                 ExprContext *econtext,
 284                                                 TupleTableSlot *slot,
 285                                                 TupleDesc inputDesc);
 286 extern void ExecAssignProjectionInfo(PlanState *planstate,
 287                                                  TupleDesc inputDesc);
 288 extern void ExecFreeExprContext(PlanState *planstate);
 289 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 290 extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
 291 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 292
 293 extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
 294
 295 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid);
 296 extern void ExecCloseScanRelation(Relation scanrel);
 297
 298 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 299 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 300 extern void ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
 301                                           EState *estate, bool is_vacuum);
 302
 303 extern void RegisterExprContextCallback(ExprContext *econtext,
 304                                                         ExprContextCallbackFunction function,
 305                                                         Datum arg);
 306 extern void UnregisterExprContextCallback(ExprContext *econtext,
 307                                                           ExprContextCallbackFunction function,
 308                                                           Datum arg);
 309
 310 #endif   /* EXECUTOR_H  */