src/include/executor/executor.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * executor.h
   4  *        support for the POSTGRES executor module
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2009, 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 ExecutorStart() */
  64 typedef void (*ExecutorStart_hook_type) (QueryDesc *queryDesc, int eflags);
  65 extern PGDLLIMPORT ExecutorStart_hook_type ExecutorStart_hook;
  66
  67 /* Hook for plugins to get control in ExecutorRun() */
  68 typedef void (*ExecutorRun_hook_type) (QueryDesc *queryDesc,
  69                                                                                                    ScanDirection direction,
  70                                                                                                    long count);
  71 extern PGDLLIMPORT ExecutorRun_hook_type ExecutorRun_hook;
  72
  73 /* Hook for plugins to get control in ExecutorEnd() */
  74 typedef void (*ExecutorEnd_hook_type) (QueryDesc *queryDesc);
  75 extern PGDLLIMPORT ExecutorEnd_hook_type ExecutorEnd_hook;
  76
  77
  78 /*
  79  * prototypes from functions in execAmi.c
  80  */
  81 extern void ExecReScan(PlanState *node, ExprContext *exprCtxt);
  82 extern void ExecMarkPos(PlanState *node);
  83 extern void ExecRestrPos(PlanState *node);
  84 extern bool ExecSupportsMarkRestore(NodeTag plantype);
  85 extern bool ExecSupportsBackwardScan(Plan *node);
  86
  87 /*
  88  * prototypes from functions in execCurrent.c
  89  */
  90 extern bool execCurrentOf(CurrentOfExpr *cexpr,
  91                           ExprContext *econtext,
  92                           Oid table_oid,
  93                           ItemPointer current_tid);
  94
  95 /*
  96  * prototypes from functions in execGrouping.c
  97  */
  98 extern bool execTuplesMatch(TupleTableSlot *slot1,
  99                                 TupleTableSlot *slot2,
 100                                 int numCols,
 101                                 AttrNumber *matchColIdx,
 102                                 FmgrInfo *eqfunctions,
 103                                 MemoryContext evalContext);
 104 extern bool execTuplesUnequal(TupleTableSlot *slot1,
 105                                   TupleTableSlot *slot2,
 106                                   int numCols,
 107                                   AttrNumber *matchColIdx,
 108                                   FmgrInfo *eqfunctions,
 109                                   MemoryContext evalContext);
 110 extern FmgrInfo *execTuplesMatchPrepare(int numCols,
 111                                            Oid *eqOperators);
 112 extern void execTuplesHashPrepare(int numCols,
 113                                           Oid *eqOperators,
 114                                           FmgrInfo **eqFunctions,
 115                                           FmgrInfo **hashFunctions);
 116 extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
 117                                         FmgrInfo *eqfunctions,
 118                                         FmgrInfo *hashfunctions,
 119                                         int nbuckets, Size entrysize,
 120                                         MemoryContext tablecxt,
 121                                         MemoryContext tempcxt);
 122 extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
 123                                          TupleTableSlot *slot,
 124                                          bool *isnew);
 125 extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
 126                                    TupleTableSlot *slot,
 127                                    FmgrInfo *eqfunctions,
 128                                    FmgrInfo *hashfunctions);
 129
 130 /*
 131  * prototypes from functions in execJunk.c
 132  */
 133 extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
 134                                    TupleTableSlot *slot);
 135 extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
 136                                                          TupleDesc cleanTupType,
 137                                                          TupleTableSlot *slot);
 138 extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
 139                                           const char *attrName);
 140 extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
 141                                          bool *isNull);
 142 extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
 143                            TupleTableSlot *slot);
 144 extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot);
 145
 146
 147 /*
 148  * prototypes from functions in execMain.c
 149  */
 150 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 151 extern void standard_ExecutorStart(QueryDesc *queryDesc, int eflags);
 152 extern void ExecutorRun(QueryDesc *queryDesc,
 153                         ScanDirection direction, long count);
 154 extern void standard_ExecutorRun(QueryDesc *queryDesc,
 155                                          ScanDirection direction, long count);
 156 extern void ExecutorEnd(QueryDesc *queryDesc);
 157 extern void standard_ExecutorEnd(QueryDesc *queryDesc);
 158 extern void ExecutorRewind(QueryDesc *queryDesc);
 159 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 160                                   Relation resultRelationDesc,
 161                                   Index resultRelationIndex,
 162                                   CmdType operation,
 163                                   bool doInstrument);
 164 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 165 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 166 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
 167                                 TupleTableSlot *slot, EState *estate);
 168 extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti,
 169                          ItemPointer tid, TransactionId priorXmax);
 170 extern PlanState *ExecGetActivePlanTree(QueryDesc *queryDesc);
 171 extern DestReceiver *CreateIntoRelDestReceiver(void);
 172
 173 /*
 174  * prototypes from functions in execProcnode.c
 175  */
 176 extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
 177 extern TupleTableSlot *ExecProcNode(PlanState *node);
 178 extern Node *MultiExecProcNode(PlanState *node);
 179 extern int      ExecCountSlotsNode(Plan *node);
 180 extern void ExecEndNode(PlanState *node);
 181
 182 /*
 183  * prototypes from functions in execQual.c
 184  */
 185 extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
 186                                   bool *isNull);
 187 extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
 188                                    bool *isNull);
 189 extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
 190                                                         ExprContext *econtext,
 191                                                         TupleDesc expectedDesc,
 192                                                         bool randomAccess);
 193 extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
 194                                                   bool *isNull, ExprDoneCond *isDone);
 195 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 196 extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 197 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 198 extern int      ExecTargetListLength(List *targetlist);
 199 extern int      ExecCleanTargetListLength(List *targetlist);
 200 extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
 201                         ExprDoneCond *isDone);
 202
 203 /*
 204  * prototypes from functions in execScan.c
 205  */
 206 typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
 207
 208 extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd);
 209 extern void ExecAssignScanProjectionInfo(ScanState *node);
 210
 211 /*
 212  * prototypes from functions in execTuples.c
 213  */
 214 extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
 215 extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
 216 extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
 217 extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
 218                                           TupleDesc tupType);
 219 extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
 220 extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
 221 extern TupleDesc ExecTypeFromExprList(List *exprList);
 222 extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
 223
 224 typedef struct TupOutputState
 225 {
 226         /* use "struct" here to allow forward reference */
 227         struct AttInMetadata *metadata;
 228         TupleTableSlot *slot;
 229         DestReceiver *dest;
 230 } TupOutputState;
 231
 232 extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
 233                                                  TupleDesc tupdesc);
 234 extern void do_tup_output(TupOutputState *tstate, char **values);
 235 extern void do_text_output_multiline(TupOutputState *tstate, char *text);
 236 extern void end_tup_output(TupOutputState *tstate);
 237
 238 /*
 239  * Write a single line of text given as a C string.
 240  *
 241  * Should only be used with a single-TEXT-attribute tupdesc.
 242  */
 243 #define do_text_output_oneline(tstate, text_to_emit) \
 244         do { \
 245                 char *values_[1]; \
 246                 values_[0] = (text_to_emit); \
 247                 do_tup_output(tstate, values_); \
 248         } while (0)
 249
 250
 251 /*
 252  * prototypes from functions in execUtils.c
 253  */
 254 extern EState *CreateExecutorState(void);
 255 extern void FreeExecutorState(EState *estate);
 256 extern ExprContext *CreateExprContext(EState *estate);
 257 extern ExprContext *CreateStandaloneExprContext(void);
 258 extern void FreeExprContext(ExprContext *econtext);
 259 extern void ReScanExprContext(ExprContext *econtext);
 260
 261 #define ResetExprContext(econtext) \
 262         MemoryContextReset((econtext)->ecxt_per_tuple_memory)
 263
 264 extern ExprContext *MakePerTupleExprContext(EState *estate);
 265
 266 /* Get an EState's per-output-tuple exprcontext, making it if first use */
 267 #define GetPerTupleExprContext(estate) \
 268         ((estate)->es_per_tuple_exprcontext ? \
 269          (estate)->es_per_tuple_exprcontext : \
 270          MakePerTupleExprContext(estate))
 271
 272 #define GetPerTupleMemoryContext(estate) \
 273         (GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
 274
 275 /* Reset an EState's per-output-tuple exprcontext, if one's been created */
 276 #define ResetPerTupleExprContext(estate) \
 277         do { \
 278                 if ((estate)->es_per_tuple_exprcontext) \
 279                         ResetExprContext((estate)->es_per_tuple_exprcontext); \
 280         } while (0)
 281
 282 extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
 283 extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
 284 extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 285 extern TupleDesc ExecGetResultType(PlanState *planstate);
 286 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
 287                                                 ExprContext *econtext,
 288                                                 TupleTableSlot *slot,
 289                                                 TupleDesc inputDesc);
 290 extern void ExecAssignProjectionInfo(PlanState *planstate,
 291                                                  TupleDesc inputDesc);
 292 extern void ExecFreeExprContext(PlanState *planstate);
 293 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 294 extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
 295 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 296
 297 extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
 298
 299 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid);
 300 extern void ExecCloseScanRelation(Relation scanrel);
 301
 302 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 303 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 304 extern void ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
 305                                           EState *estate, bool is_vacuum);
 306
 307 extern void RegisterExprContextCallback(ExprContext *econtext,
 308                                                         ExprContextCallbackFunction function,
 309                                                         Datum arg);
 310 extern void UnregisterExprContextCallback(ExprContext *econtext,
 311                                                           ExprContextCallbackFunction function,
 312                                                           Datum arg);
 313
 314 #endif   /* EXECUTOR_H  */