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