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) 1996-2012, 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
  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  * SKIP_TRIGGERS tells ExecutorStart/ExecutorFinish to skip calling
  49  * AfterTriggerBeginQuery/AfterTriggerEndQuery.  This does not necessarily
  50  * mean that the plan can't queue any AFTER triggers; just that the caller
  51  * is responsible for there being a trigger context for them to be queued in.
  52  */
  53 #define EXEC_FLAG_EXPLAIN_ONLY  0x0001  /* EXPLAIN, no ANALYZE */
  54 #define EXEC_FLAG_REWIND                0x0002  /* need efficient rescan */
  55 #define EXEC_FLAG_BACKWARD              0x0004  /* need backward scan */
  56 #define EXEC_FLAG_MARK                  0x0008  /* need mark/restore */
  57 #define EXEC_FLAG_SKIP_TRIGGERS 0x0010  /* skip AfterTrigger calls */
  58
  59
  60 /*
  61  * ExecEvalExpr was formerly a function containing a switch statement;
  62  * now it's just a macro invoking the function pointed to by an ExprState
  63  * node.  Beware of double evaluation of the ExprState argument!
  64  */
  65 #define ExecEvalExpr(expr, econtext, isNull, isDone) \
  66         ((*(expr)->evalfunc) (expr, econtext, isNull, isDone))
  67
  68
  69 /* Hook for plugins to get control in ExecutorStart() */
  70 typedef void (*ExecutorStart_hook_type) (QueryDesc *queryDesc, int eflags);
  71 extern PGDLLIMPORT ExecutorStart_hook_type ExecutorStart_hook;
  72
  73 /* Hook for plugins to get control in ExecutorRun() */
  74 typedef void (*ExecutorRun_hook_type) (QueryDesc *queryDesc,
  75                                                                                                    ScanDirection direction,
  76                                                                                                    long count);
  77 extern PGDLLIMPORT ExecutorRun_hook_type ExecutorRun_hook;
  78
  79 /* Hook for plugins to get control in ExecutorFinish() */
  80 typedef void (*ExecutorFinish_hook_type) (QueryDesc *queryDesc);
  81 extern PGDLLIMPORT ExecutorFinish_hook_type ExecutorFinish_hook;
  82
  83 /* Hook for plugins to get control in ExecutorEnd() */
  84 typedef void (*ExecutorEnd_hook_type) (QueryDesc *queryDesc);
  85 extern PGDLLIMPORT ExecutorEnd_hook_type ExecutorEnd_hook;
  86
  87 /* Hook for plugins to get control in ExecCheckRTPerms() */
  88 typedef bool (*ExecutorCheckPerms_hook_type) (List *, bool);
  89 extern PGDLLIMPORT ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook;
  90
  91
  92 /*
  93  * prototypes from functions in execAmi.c
  94  */
  95 extern void ExecReScan(PlanState *node);
  96 extern void ExecMarkPos(PlanState *node);
  97 extern void ExecRestrPos(PlanState *node);
  98 extern bool ExecSupportsMarkRestore(NodeTag plantype);
  99 extern bool ExecSupportsBackwardScan(Plan *node);
 100 extern bool ExecMaterializesOutput(NodeTag plantype);
 101
 102 /*
 103  * prototypes from functions in execCurrent.c
 104  */
 105 extern bool execCurrentOf(CurrentOfExpr *cexpr,
 106                           ExprContext *econtext,
 107                           Oid table_oid,
 108                           ItemPointer current_tid);
 109
 110 /*
 111  * prototypes from functions in execGrouping.c
 112  */
 113 extern bool execTuplesMatch(TupleTableSlot *slot1,
 114                                 TupleTableSlot *slot2,
 115                                 int numCols,
 116                                 AttrNumber *matchColIdx,
 117                                 FmgrInfo *eqfunctions,
 118                                 MemoryContext evalContext);
 119 extern bool execTuplesUnequal(TupleTableSlot *slot1,
 120                                   TupleTableSlot *slot2,
 121                                   int numCols,
 122                                   AttrNumber *matchColIdx,
 123                                   FmgrInfo *eqfunctions,
 124                                   MemoryContext evalContext);
 125 extern FmgrInfo *execTuplesMatchPrepare(int numCols,
 126                                            Oid *eqOperators);
 127 extern void execTuplesHashPrepare(int numCols,
 128                                           Oid *eqOperators,
 129                                           FmgrInfo **eqFunctions,
 130                                           FmgrInfo **hashFunctions);
 131 extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
 132                                         FmgrInfo *eqfunctions,
 133                                         FmgrInfo *hashfunctions,
 134                                         long nbuckets, Size entrysize,
 135                                         MemoryContext tablecxt,
 136                                         MemoryContext tempcxt);
 137 extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
 138                                          TupleTableSlot *slot,
 139                                          bool *isnew);
 140 extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
 141                                    TupleTableSlot *slot,
 142                                    FmgrInfo *eqfunctions,
 143                                    FmgrInfo *hashfunctions);
 144
 145 /*
 146  * prototypes from functions in execJunk.c
 147  */
 148 extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
 149                                    TupleTableSlot *slot);
 150 extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
 151                                                          TupleDesc cleanTupType,
 152                                                          TupleTableSlot *slot);
 153 extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
 154                                           const char *attrName);
 155 extern AttrNumber ExecFindJunkAttributeInTlist(List *targetlist,
 156                                                          const char *attrName);
 157 extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
 158                                          bool *isNull);
 159 extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
 160                            TupleTableSlot *slot);
 161
 162
 163 /*
 164  * prototypes from functions in execMain.c
 165  */
 166 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 167 extern void standard_ExecutorStart(QueryDesc *queryDesc, int eflags);
 168 extern void ExecutorRun(QueryDesc *queryDesc,
 169                         ScanDirection direction, long count);
 170 extern void standard_ExecutorRun(QueryDesc *queryDesc,
 171                                          ScanDirection direction, long count);
 172 extern void ExecutorFinish(QueryDesc *queryDesc);
 173 extern void standard_ExecutorFinish(QueryDesc *queryDesc);
 174 extern void ExecutorEnd(QueryDesc *queryDesc);
 175 extern void standard_ExecutorEnd(QueryDesc *queryDesc);
 176 extern void ExecutorRewind(QueryDesc *queryDesc);
 177 extern bool ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation);
 178 extern void CheckValidResultRel(Relation resultRel, CmdType operation);
 179 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 180                                   Relation resultRelationDesc,
 181                                   Index resultRelationIndex,
 182                                   int instrument_options);
 183 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 184 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 185 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
 186                                 TupleTableSlot *slot, EState *estate);
 187 extern ExecRowMark *ExecFindRowMark(EState *estate, Index rti);
 188 extern ExecAuxRowMark *ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist);
 189 extern TupleTableSlot *EvalPlanQual(EState *estate, EPQState *epqstate,
 190                          Relation relation, Index rti,
 191                          ItemPointer tid, TransactionId priorXmax);
 192 extern HeapTuple EvalPlanQualFetch(EState *estate, Relation relation,
 193                                   int lockmode, ItemPointer tid, TransactionId priorXmax);
 194 extern void EvalPlanQualInit(EPQState *epqstate, EState *estate,
 195                                  Plan *subplan, List *auxrowmarks, int epqParam);
 196 extern void EvalPlanQualSetPlan(EPQState *epqstate,
 197                                         Plan *subplan, List *auxrowmarks);
 198 extern void EvalPlanQualSetTuple(EPQState *epqstate, Index rti,
 199                                          HeapTuple tuple);
 200 extern HeapTuple EvalPlanQualGetTuple(EPQState *epqstate, Index rti);
 201
 202 #define EvalPlanQualSetSlot(epqstate, slot)  ((epqstate)->origslot = (slot))
 203 extern void EvalPlanQualFetchRowMarks(EPQState *epqstate);
 204 extern TupleTableSlot *EvalPlanQualNext(EPQState *epqstate);
 205 extern void EvalPlanQualBegin(EPQState *epqstate, EState *parentestate);
 206 extern void EvalPlanQualEnd(EPQState *epqstate);
 207 extern DestReceiver *CreateIntoRelDestReceiver(void);
 208
 209 /*
 210  * prototypes from functions in execProcnode.c
 211  */
 212 extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
 213 extern TupleTableSlot *ExecProcNode(PlanState *node);
 214 extern Node *MultiExecProcNode(PlanState *node);
 215 extern void ExecEndNode(PlanState *node);
 216
 217 /*
 218  * prototypes from functions in execQual.c
 219  */
 220 extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
 221                                   bool *isNull);
 222 extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
 223                                    bool *isNull);
 224 extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
 225                                                         ExprContext *econtext,
 226                                                         TupleDesc expectedDesc,
 227                                                         bool randomAccess);
 228 extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
 229                                                   bool *isNull, ExprDoneCond *isDone);
 230 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 231 extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 232 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 233 extern int      ExecTargetListLength(List *targetlist);
 234 extern int      ExecCleanTargetListLength(List *targetlist);
 235 extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
 236                         ExprDoneCond *isDone);
 237
 238 /*
 239  * prototypes from functions in execScan.c
 240  */
 241 typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
 242 typedef bool (*ExecScanRecheckMtd) (ScanState *node, TupleTableSlot *slot);
 243
 244 extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd,
 245                  ExecScanRecheckMtd recheckMtd);
 246 extern void ExecAssignScanProjectionInfo(ScanState *node);
 247 extern void ExecScanReScan(ScanState *node);
 248
 249 /*
 250  * prototypes from functions in execTuples.c
 251  */
 252 extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
 253 extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
 254 extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
 255 extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
 256                                           TupleDesc tupType);
 257 extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
 258 extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
 259 extern TupleDesc ExecTypeFromExprList(List *exprList);
 260 extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
 261
 262 typedef struct TupOutputState
 263 {
 264         TupleTableSlot *slot;
 265         DestReceiver *dest;
 266 } TupOutputState;
 267
 268 extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
 269                                                  TupleDesc tupdesc);
 270 extern void do_tup_output(TupOutputState *tstate, Datum *values, bool *isnull);
 271 extern void do_text_output_multiline(TupOutputState *tstate, char *text);
 272 extern void end_tup_output(TupOutputState *tstate);
 273
 274 /*
 275  * Write a single line of text given as a C string.
 276  *
 277  * Should only be used with a single-TEXT-attribute tupdesc.
 278  */
 279 #define do_text_output_oneline(tstate, str_to_emit) \
 280         do { \
 281                 Datum   values_[1]; \
 282                 bool    isnull_[1]; \
 283                 values_[0] = PointerGetDatum(cstring_to_text(str_to_emit)); \
 284                 isnull_[0] = false; \
 285                 do_tup_output(tstate, values_, isnull_); \
 286                 pfree(DatumGetPointer(values_[0])); \
 287         } while (0)
 288
 289
 290 /*
 291  * prototypes from functions in execUtils.c
 292  */
 293 extern EState *CreateExecutorState(void);
 294 extern void FreeExecutorState(EState *estate);
 295 extern ExprContext *CreateExprContext(EState *estate);
 296 extern ExprContext *CreateStandaloneExprContext(void);
 297 extern void FreeExprContext(ExprContext *econtext, bool isCommit);
 298 extern void ReScanExprContext(ExprContext *econtext);
 299
 300 #define ResetExprContext(econtext) \
 301         MemoryContextReset((econtext)->ecxt_per_tuple_memory)
 302
 303 extern ExprContext *MakePerTupleExprContext(EState *estate);
 304
 305 /* Get an EState's per-output-tuple exprcontext, making it if first use */
 306 #define GetPerTupleExprContext(estate) \
 307         ((estate)->es_per_tuple_exprcontext ? \
 308          (estate)->es_per_tuple_exprcontext : \
 309          MakePerTupleExprContext(estate))
 310
 311 #define GetPerTupleMemoryContext(estate) \
 312         (GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
 313
 314 /* Reset an EState's per-output-tuple exprcontext, if one's been created */
 315 #define ResetPerTupleExprContext(estate) \
 316         do { \
 317                 if ((estate)->es_per_tuple_exprcontext) \
 318                         ResetExprContext((estate)->es_per_tuple_exprcontext); \
 319         } while (0)
 320
 321 extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
 322 extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
 323 extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 324 extern TupleDesc ExecGetResultType(PlanState *planstate);
 325 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
 326                                                 ExprContext *econtext,
 327                                                 TupleTableSlot *slot,
 328                                                 TupleDesc inputDesc);
 329 extern void ExecAssignProjectionInfo(PlanState *planstate,
 330                                                  TupleDesc inputDesc);
 331 extern void ExecFreeExprContext(PlanState *planstate);
 332 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 333 extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
 334 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 335
 336 extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
 337
 338 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid);
 339 extern void ExecCloseScanRelation(Relation scanrel);
 340
 341 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 342 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 343 extern List *ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
 344                                           EState *estate);
 345 extern bool check_exclusion_constraint(Relation heap, Relation index,
 346                                                    IndexInfo *indexInfo,
 347                                                    ItemPointer tupleid,
 348                                                    Datum *values, bool *isnull,
 349                                                    EState *estate,
 350                                                    bool newIndex, bool errorOK);
 351
 352 extern void RegisterExprContextCallback(ExprContext *econtext,
 353                                                         ExprContextCallbackFunction function,
 354                                                         Datum arg);
 355 extern void UnregisterExprContextCallback(ExprContext *econtext,
 356                                                           ExprContextCallbackFunction function,
 357                                                           Datum arg);
 358
 359 #endif   /* EXECUTOR_H  */