granicus.if.org Git - postgresql/blob - src/include/executor/executor.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * executor.h
   4  *        support for the POSTGRES executor module
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * src/include/executor/executor.h
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef EXECUTOR_H
  15 #define EXECUTOR_H
  16
  17 #include "executor/execdesc.h"
  18 #include "nodes/parsenodes.h"
  19 #include "nodes/relation.h"
  20 #include "utils/lockwaitpolicy.h"
  21
  22
  23 /*
  24  * The "eflags" argument to ExecutorStart and the various ExecInitNode
  25  * routines is a bitwise OR of the following flag bits, which tell the
  26  * called plan node what to expect.  Note that the flags will get modified
  27  * as they are passed down the plan tree, since an upper node may require
  28  * functionality in its subnode not demanded of the plan as a whole
  29  * (example: MergeJoin requires mark/restore capability in its inner input),
  30  * or an upper node may shield its input from some functionality requirement
  31  * (example: Materialize shields its input from needing to do backward scan).
  32  *
  33  * EXPLAIN_ONLY indicates that the plan tree is being initialized just so
  34  * EXPLAIN can print it out; it will not be run.  Hence, no side-effects
  35  * of startup should occur.  However, error checks (such as permission checks)
  36  * should be performed.
  37  *
  38  * REWIND indicates that the plan node should try to efficiently support
  39  * rescans without parameter changes.  (Nodes must support ExecReScan calls
  40  * in any case, but if this flag was not given, they are at liberty to do it
  41  * through complete recalculation.  Note that a parameter change forces a
  42  * full recalculation in any case.)
  43  *
  44  * BACKWARD indicates that the plan node must respect the es_direction flag.
  45  * When this is not passed, the plan node will only be run forwards.
  46  *
  47  * MARK indicates that the plan node must support Mark/Restore calls.
  48  * When this is not passed, no Mark/Restore will occur.
  49  *
  50  * SKIP_TRIGGERS tells ExecutorStart/ExecutorFinish to skip calling
  51  * AfterTriggerBeginQuery/AfterTriggerEndQuery.  This does not necessarily
  52  * mean that the plan can't queue any AFTER triggers; just that the caller
  53  * is responsible for there being a trigger context for them to be queued in.
  54  *
  55  * WITH/WITHOUT_OIDS tell the executor to emit tuples with or without space
  56  * for OIDs, respectively.  These are currently used only for CREATE TABLE AS.
  57  * If neither is set, the plan may or may not produce tuples including OIDs.
  58  */
  59 #define EXEC_FLAG_EXPLAIN_ONLY  0x0001  /* EXPLAIN, no ANALYZE */
  60 #define EXEC_FLAG_REWIND                0x0002  /* need efficient rescan */
  61 #define EXEC_FLAG_BACKWARD              0x0004  /* need backward scan */
  62 #define EXEC_FLAG_MARK                  0x0008  /* need mark/restore */
  63 #define EXEC_FLAG_SKIP_TRIGGERS 0x0010  /* skip AfterTrigger calls */
  64 #define EXEC_FLAG_WITH_OIDS             0x0020  /* force OIDs in returned tuples */
  65 #define EXEC_FLAG_WITHOUT_OIDS  0x0040  /* force no OIDs in returned tuples */
  66 #define EXEC_FLAG_WITH_NO_DATA  0x0080  /* rel scannability doesn't matter */
  67
  68
  69 /*
  70  * ExecEvalExpr was formerly a function containing a switch statement;
  71  * now it's just a macro invoking the function pointed to by an ExprState
  72  * node.  Beware of double evaluation of the ExprState argument!
  73  */
  74 #define ExecEvalExpr(expr, econtext, isNull, isDone) \
  75         ((*(expr)->evalfunc) (expr, econtext, isNull, isDone))
  76
  77
  78 /* Hook for plugins to get control in ExecutorStart() */
  79 typedef void (*ExecutorStart_hook_type) (QueryDesc *queryDesc, int eflags);
  80 extern PGDLLIMPORT ExecutorStart_hook_type ExecutorStart_hook;
  81
  82 /* Hook for plugins to get control in ExecutorRun() */
  83 typedef void (*ExecutorRun_hook_type) (QueryDesc *queryDesc,
  84                                                                                                    ScanDirection direction,
  85                                                                                                    long count);
  86 extern PGDLLIMPORT ExecutorRun_hook_type ExecutorRun_hook;
  87
  88 /* Hook for plugins to get control in ExecutorFinish() */
  89 typedef void (*ExecutorFinish_hook_type) (QueryDesc *queryDesc);
  90 extern PGDLLIMPORT ExecutorFinish_hook_type ExecutorFinish_hook;
  91
  92 /* Hook for plugins to get control in ExecutorEnd() */
  93 typedef void (*ExecutorEnd_hook_type) (QueryDesc *queryDesc);
  94 extern PGDLLIMPORT ExecutorEnd_hook_type ExecutorEnd_hook;
  95
  96 /* Hook for plugins to get control in ExecCheckRTPerms() */
  97 typedef bool (*ExecutorCheckPerms_hook_type) (List *, bool);
  98 extern PGDLLIMPORT ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook;
  99
 100
 101 /*
 102  * prototypes from functions in execAmi.c
 103  */
 104 extern void ExecReScan(PlanState *node);
 105 extern void ExecMarkPos(PlanState *node);
 106 extern void ExecRestrPos(PlanState *node);
 107 extern bool ExecSupportsMarkRestore(Path *pathnode);
 108 extern bool ExecSupportsBackwardScan(Plan *node);
 109 extern bool ExecMaterializesOutput(NodeTag plantype);
 110
 111 /*
 112  * prototypes from functions in execCurrent.c
 113  */
 114 extern bool execCurrentOf(CurrentOfExpr *cexpr,
 115                           ExprContext *econtext,
 116                           Oid table_oid,
 117                           ItemPointer current_tid);
 118
 119 /*
 120  * prototypes from functions in execGrouping.c
 121  */
 122 extern bool execTuplesMatch(TupleTableSlot *slot1,
 123                                 TupleTableSlot *slot2,
 124                                 int numCols,
 125                                 AttrNumber *matchColIdx,
 126                                 FmgrInfo *eqfunctions,
 127                                 MemoryContext evalContext);
 128 extern bool execTuplesUnequal(TupleTableSlot *slot1,
 129                                   TupleTableSlot *slot2,
 130                                   int numCols,
 131                                   AttrNumber *matchColIdx,
 132                                   FmgrInfo *eqfunctions,
 133                                   MemoryContext evalContext);
 134 extern FmgrInfo *execTuplesMatchPrepare(int numCols,
 135                                            Oid *eqOperators);
 136 extern void execTuplesHashPrepare(int numCols,
 137                                           Oid *eqOperators,
 138                                           FmgrInfo **eqFunctions,
 139                                           FmgrInfo **hashFunctions);
 140 extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
 141                                         FmgrInfo *eqfunctions,
 142                                         FmgrInfo *hashfunctions,
 143                                         long nbuckets, Size entrysize,
 144                                         MemoryContext tablecxt,
 145                                         MemoryContext tempcxt);
 146 extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
 147                                          TupleTableSlot *slot,
 148                                          bool *isnew);
 149 extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
 150                                    TupleTableSlot *slot,
 151                                    FmgrInfo *eqfunctions,
 152                                    FmgrInfo *hashfunctions);
 153
 154 /*
 155  * prototypes from functions in execJunk.c
 156  */
 157 extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
 158                                    TupleTableSlot *slot);
 159 extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
 160                                                          TupleDesc cleanTupType,
 161                                                          TupleTableSlot *slot);
 162 extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
 163                                           const char *attrName);
 164 extern AttrNumber ExecFindJunkAttributeInTlist(List *targetlist,
 165                                                          const char *attrName);
 166 extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
 167                                          bool *isNull);
 168 extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
 169                            TupleTableSlot *slot);
 170
 171
 172 /*
 173  * prototypes from functions in execMain.c
 174  */
 175 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 176 extern void standard_ExecutorStart(QueryDesc *queryDesc, int eflags);
 177 extern void ExecutorRun(QueryDesc *queryDesc,
 178                         ScanDirection direction, long count);
 179 extern void standard_ExecutorRun(QueryDesc *queryDesc,
 180                                          ScanDirection direction, long count);
 181 extern void ExecutorFinish(QueryDesc *queryDesc);
 182 extern void standard_ExecutorFinish(QueryDesc *queryDesc);
 183 extern void ExecutorEnd(QueryDesc *queryDesc);
 184 extern void standard_ExecutorEnd(QueryDesc *queryDesc);
 185 extern void ExecutorRewind(QueryDesc *queryDesc);
 186 extern bool ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation);
 187 extern void CheckValidResultRel(Relation resultRel, CmdType operation);
 188 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 189                                   Relation resultRelationDesc,
 190                                   Index resultRelationIndex,
 191                                   int instrument_options);
 192 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 193 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 194 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
 195                                 TupleTableSlot *slot, EState *estate);
 196 extern void ExecWithCheckOptions(ResultRelInfo *resultRelInfo,
 197                                          TupleTableSlot *slot, EState *estate);
 198 extern ExecRowMark *ExecFindRowMark(EState *estate, Index rti);
 199 extern ExecAuxRowMark *ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist);
 200 extern TupleTableSlot *EvalPlanQual(EState *estate, EPQState *epqstate,
 201                          Relation relation, Index rti, int lockmode,
 202                          ItemPointer tid, TransactionId priorXmax);
 203 extern HeapTuple EvalPlanQualFetch(EState *estate, Relation relation,
 204                                   int lockmode, LockWaitPolicy wait_policy, ItemPointer tid,
 205                                   TransactionId priorXmax);
 206 extern void EvalPlanQualInit(EPQState *epqstate, EState *estate,
 207                                  Plan *subplan, List *auxrowmarks, int epqParam);
 208 extern void EvalPlanQualSetPlan(EPQState *epqstate,
 209                                         Plan *subplan, List *auxrowmarks);
 210 extern void EvalPlanQualSetTuple(EPQState *epqstate, Index rti,
 211                                          HeapTuple tuple);
 212 extern HeapTuple EvalPlanQualGetTuple(EPQState *epqstate, Index rti);
 213
 214 #define EvalPlanQualSetSlot(epqstate, slot)  ((epqstate)->origslot = (slot))
 215 extern void EvalPlanQualFetchRowMarks(EPQState *epqstate);
 216 extern TupleTableSlot *EvalPlanQualNext(EPQState *epqstate);
 217 extern void EvalPlanQualBegin(EPQState *epqstate, EState *parentestate);
 218 extern void EvalPlanQualEnd(EPQState *epqstate);
 219
 220 /*
 221  * prototypes from functions in execProcnode.c
 222  */
 223 extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
 224 extern TupleTableSlot *ExecProcNode(PlanState *node);
 225 extern Node *MultiExecProcNode(PlanState *node);
 226 extern void ExecEndNode(PlanState *node);
 227
 228 /*
 229  * prototypes from functions in execQual.c
 230  */
 231 extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
 232                                   bool *isNull);
 233 extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
 234                                    bool *isNull);
 235 extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
 236                                                         ExprContext *econtext,
 237                                                         MemoryContext argContext,
 238                                                         TupleDesc expectedDesc,
 239                                                         bool randomAccess);
 240 extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
 241                                                   bool *isNull, ExprDoneCond *isDone);
 242 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 243 extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 244 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 245 extern int      ExecTargetListLength(List *targetlist);
 246 extern int      ExecCleanTargetListLength(List *targetlist);
 247 extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
 248                         ExprDoneCond *isDone);
 249
 250 /*
 251  * prototypes from functions in execScan.c
 252  */
 253 typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
 254 typedef bool (*ExecScanRecheckMtd) (ScanState *node, TupleTableSlot *slot);
 255
 256 extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd,
 257                  ExecScanRecheckMtd recheckMtd);
 258 extern void ExecAssignScanProjectionInfo(ScanState *node);
 259 extern void ExecScanReScan(ScanState *node);
 260
 261 /*
 262  * prototypes from functions in execTuples.c
 263  */
 264 extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
 265 extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
 266 extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
 267 extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
 268                                           TupleDesc tupType);
 269 extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
 270 extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
 271 extern TupleDesc ExecTypeFromExprList(List *exprList);
 272 extern void ExecTypeSetColNames(TupleDesc typeInfo, List *namesList);
 273 extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
 274
 275 typedef struct TupOutputState
 276 {
 277         TupleTableSlot *slot;
 278         DestReceiver *dest;
 279 } TupOutputState;
 280
 281 extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
 282                                                  TupleDesc tupdesc);
 283 extern void do_tup_output(TupOutputState *tstate, Datum *values, bool *isnull);
 284 extern void do_text_output_multiline(TupOutputState *tstate, char *text);
 285 extern void end_tup_output(TupOutputState *tstate);
 286
 287 /*
 288  * Write a single line of text given as a C string.
 289  *
 290  * Should only be used with a single-TEXT-attribute tupdesc.
 291  */
 292 #define do_text_output_oneline(tstate, str_to_emit) \
 293         do { \
 294                 Datum   values_[1]; \
 295                 bool    isnull_[1]; \
 296                 values_[0] = PointerGetDatum(cstring_to_text(str_to_emit)); \
 297                 isnull_[0] = false; \
 298                 do_tup_output(tstate, values_, isnull_); \
 299                 pfree(DatumGetPointer(values_[0])); \
 300         } while (0)
 301
 302
 303 /*
 304  * prototypes from functions in execUtils.c
 305  */
 306 extern EState *CreateExecutorState(void);
 307 extern void FreeExecutorState(EState *estate);
 308 extern ExprContext *CreateExprContext(EState *estate);
 309 extern ExprContext *CreateStandaloneExprContext(void);
 310 extern void FreeExprContext(ExprContext *econtext, bool isCommit);
 311 extern void ReScanExprContext(ExprContext *econtext);
 312
 313 #define ResetExprContext(econtext) \
 314         MemoryContextReset((econtext)->ecxt_per_tuple_memory)
 315
 316 extern ExprContext *MakePerTupleExprContext(EState *estate);
 317
 318 /* Get an EState's per-output-tuple exprcontext, making it if first use */
 319 #define GetPerTupleExprContext(estate) \
 320         ((estate)->es_per_tuple_exprcontext ? \
 321          (estate)->es_per_tuple_exprcontext : \
 322          MakePerTupleExprContext(estate))
 323
 324 #define GetPerTupleMemoryContext(estate) \
 325         (GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
 326
 327 /* Reset an EState's per-output-tuple exprcontext, if one's been created */
 328 #define ResetPerTupleExprContext(estate) \
 329         do { \
 330                 if ((estate)->es_per_tuple_exprcontext) \
 331                         ResetExprContext((estate)->es_per_tuple_exprcontext); \
 332         } while (0)
 333
 334 extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
 335 extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
 336 extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 337 extern TupleDesc ExecGetResultType(PlanState *planstate);
 338 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
 339                                                 ExprContext *econtext,
 340                                                 TupleTableSlot *slot,
 341                                                 TupleDesc inputDesc);
 342 extern void ExecAssignProjectionInfo(PlanState *planstate,
 343                                                  TupleDesc inputDesc);
 344 extern void ExecFreeExprContext(PlanState *planstate);
 345 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 346 extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
 347 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 348
 349 extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
 350
 351 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags);
 352 extern void ExecCloseScanRelation(Relation scanrel);
 353
 354 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 355 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 356 extern List *ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
 357                                           EState *estate);
 358 extern bool check_exclusion_constraint(Relation heap, Relation index,
 359                                                    IndexInfo *indexInfo,
 360                                                    ItemPointer tupleid,
 361                                                    Datum *values, bool *isnull,
 362                                                    EState *estate,
 363                                                    bool newIndex, bool errorOK);
 364
 365 extern void RegisterExprContextCallback(ExprContext *econtext,
 366                                                         ExprContextCallbackFunction function,
 367                                                         Datum arg);
 368 extern void UnregisterExprContextCallback(ExprContext *econtext,
 369                                                           ExprContextCallbackFunction function,
 370                                                           Datum arg);
 371
 372 #endif   /* EXECUTOR_H  */