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 struct Path;                                    /* avoid including relation.h here */
 104
 105 extern void ExecReScan(PlanState *node);
 106 extern void ExecMarkPos(PlanState *node);
 107 extern void ExecRestrPos(PlanState *node);
 108 extern bool ExecSupportsMarkRestore(struct Path *pathnode);
 109 extern bool ExecSupportsBackwardScan(Plan *node);
 110 extern bool ExecMaterializesOutput(NodeTag plantype);
 111
 112 /*
 113  * prototypes from functions in execCurrent.c
 114  */
 115 extern bool execCurrentOf(CurrentOfExpr *cexpr,
 116                           ExprContext *econtext,
 117                           Oid table_oid,
 118                           ItemPointer current_tid);
 119
 120 /*
 121  * prototypes from functions in execGrouping.c
 122  */
 123 extern bool execTuplesMatch(TupleTableSlot *slot1,
 124                                 TupleTableSlot *slot2,
 125                                 int numCols,
 126                                 AttrNumber *matchColIdx,
 127                                 FmgrInfo *eqfunctions,
 128                                 MemoryContext evalContext);
 129 extern bool execTuplesUnequal(TupleTableSlot *slot1,
 130                                   TupleTableSlot *slot2,
 131                                   int numCols,
 132                                   AttrNumber *matchColIdx,
 133                                   FmgrInfo *eqfunctions,
 134                                   MemoryContext evalContext);
 135 extern FmgrInfo *execTuplesMatchPrepare(int numCols,
 136                                            Oid *eqOperators);
 137 extern void execTuplesHashPrepare(int numCols,
 138                                           Oid *eqOperators,
 139                                           FmgrInfo **eqFunctions,
 140                                           FmgrInfo **hashFunctions);
 141 extern TupleHashTable BuildTupleHashTable(int numCols, AttrNumber *keyColIdx,
 142                                         FmgrInfo *eqfunctions,
 143                                         FmgrInfo *hashfunctions,
 144                                         long nbuckets, Size entrysize,
 145                                         MemoryContext tablecxt,
 146                                         MemoryContext tempcxt);
 147 extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
 148                                          TupleTableSlot *slot,
 149                                          bool *isnew);
 150 extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
 151                                    TupleTableSlot *slot,
 152                                    FmgrInfo *eqfunctions,
 153                                    FmgrInfo *hashfunctions);
 154
 155 /*
 156  * prototypes from functions in execJunk.c
 157  */
 158 extern JunkFilter *ExecInitJunkFilter(List *targetList, bool hasoid,
 159                                    TupleTableSlot *slot);
 160 extern JunkFilter *ExecInitJunkFilterConversion(List *targetList,
 161                                                          TupleDesc cleanTupType,
 162                                                          TupleTableSlot *slot);
 163 extern AttrNumber ExecFindJunkAttribute(JunkFilter *junkfilter,
 164                                           const char *attrName);
 165 extern AttrNumber ExecFindJunkAttributeInTlist(List *targetlist,
 166                                                          const char *attrName);
 167 extern Datum ExecGetJunkAttribute(TupleTableSlot *slot, AttrNumber attno,
 168                                          bool *isNull);
 169 extern TupleTableSlot *ExecFilterJunk(JunkFilter *junkfilter,
 170                            TupleTableSlot *slot);
 171
 172
 173 /*
 174  * prototypes from functions in execMain.c
 175  */
 176 extern void ExecutorStart(QueryDesc *queryDesc, int eflags);
 177 extern void standard_ExecutorStart(QueryDesc *queryDesc, int eflags);
 178 extern void ExecutorRun(QueryDesc *queryDesc,
 179                         ScanDirection direction, long count);
 180 extern void standard_ExecutorRun(QueryDesc *queryDesc,
 181                                          ScanDirection direction, long count);
 182 extern void ExecutorFinish(QueryDesc *queryDesc);
 183 extern void standard_ExecutorFinish(QueryDesc *queryDesc);
 184 extern void ExecutorEnd(QueryDesc *queryDesc);
 185 extern void standard_ExecutorEnd(QueryDesc *queryDesc);
 186 extern void ExecutorRewind(QueryDesc *queryDesc);
 187 extern bool ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation);
 188 extern void CheckValidResultRel(Relation resultRel, CmdType operation);
 189 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 190                                   Relation resultRelationDesc,
 191                                   Index resultRelationIndex,
 192                                   int instrument_options);
 193 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 194 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);
 195 extern void ExecConstraints(ResultRelInfo *resultRelInfo,
 196                                 TupleTableSlot *slot, EState *estate);
 197 extern void ExecWithCheckOptions(ResultRelInfo *resultRelInfo,
 198                                          TupleTableSlot *slot, EState *estate);
 199 extern ExecRowMark *ExecFindRowMark(EState *estate, Index rti);
 200 extern ExecAuxRowMark *ExecBuildAuxRowMark(ExecRowMark *erm, List *targetlist);
 201 extern TupleTableSlot *EvalPlanQual(EState *estate, EPQState *epqstate,
 202                          Relation relation, Index rti, int lockmode,
 203                          ItemPointer tid, TransactionId priorXmax);
 204 extern HeapTuple EvalPlanQualFetch(EState *estate, Relation relation,
 205                                   int lockmode, LockWaitPolicy wait_policy, ItemPointer tid,
 206                                   TransactionId priorXmax);
 207 extern void EvalPlanQualInit(EPQState *epqstate, EState *estate,
 208                                  Plan *subplan, List *auxrowmarks, int epqParam);
 209 extern void EvalPlanQualSetPlan(EPQState *epqstate,
 210                                         Plan *subplan, List *auxrowmarks);
 211 extern void EvalPlanQualSetTuple(EPQState *epqstate, Index rti,
 212                                          HeapTuple tuple);
 213 extern HeapTuple EvalPlanQualGetTuple(EPQState *epqstate, Index rti);
 214
 215 #define EvalPlanQualSetSlot(epqstate, slot)  ((epqstate)->origslot = (slot))
 216 extern void EvalPlanQualFetchRowMarks(EPQState *epqstate);
 217 extern TupleTableSlot *EvalPlanQualNext(EPQState *epqstate);
 218 extern void EvalPlanQualBegin(EPQState *epqstate, EState *parentestate);
 219 extern void EvalPlanQualEnd(EPQState *epqstate);
 220
 221 /*
 222  * prototypes from functions in execProcnode.c
 223  */
 224 extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags);
 225 extern TupleTableSlot *ExecProcNode(PlanState *node);
 226 extern Node *MultiExecProcNode(PlanState *node);
 227 extern void ExecEndNode(PlanState *node);
 228
 229 /*
 230  * prototypes from functions in execQual.c
 231  */
 232 extern Datum GetAttributeByNum(HeapTupleHeader tuple, AttrNumber attrno,
 233                                   bool *isNull);
 234 extern Datum GetAttributeByName(HeapTupleHeader tuple, const char *attname,
 235                                    bool *isNull);
 236 extern Tuplestorestate *ExecMakeTableFunctionResult(ExprState *funcexpr,
 237                                                         ExprContext *econtext,
 238                                                         MemoryContext argContext,
 239                                                         TupleDesc expectedDesc,
 240                                                         bool randomAccess);
 241 extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econtext,
 242                                                   bool *isNull, ExprDoneCond *isDone);
 243 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 244 extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 245 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 246 extern int      ExecTargetListLength(List *targetlist);
 247 extern int      ExecCleanTargetListLength(List *targetlist);
 248 extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
 249                         ExprDoneCond *isDone);
 250
 251 /*
 252  * prototypes from functions in execScan.c
 253  */
 254 typedef TupleTableSlot *(*ExecScanAccessMtd) (ScanState *node);
 255 typedef bool (*ExecScanRecheckMtd) (ScanState *node, TupleTableSlot *slot);
 256
 257 extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd,
 258                  ExecScanRecheckMtd recheckMtd);
 259 extern void ExecAssignScanProjectionInfo(ScanState *node);
 260 extern void ExecScanReScan(ScanState *node);
 261
 262 /*
 263  * prototypes from functions in execTuples.c
 264  */
 265 extern void ExecInitResultTupleSlot(EState *estate, PlanState *planstate);
 266 extern void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate);
 267 extern TupleTableSlot *ExecInitExtraTupleSlot(EState *estate);
 268 extern TupleTableSlot *ExecInitNullTupleSlot(EState *estate,
 269                                           TupleDesc tupType);
 270 extern TupleDesc ExecTypeFromTL(List *targetList, bool hasoid);
 271 extern TupleDesc ExecCleanTypeFromTL(List *targetList, bool hasoid);
 272 extern TupleDesc ExecTypeFromExprList(List *exprList);
 273 extern void ExecTypeSetColNames(TupleDesc typeInfo, List *namesList);
 274 extern void UpdateChangedParamSet(PlanState *node, Bitmapset *newchg);
 275
 276 typedef struct TupOutputState
 277 {
 278         TupleTableSlot *slot;
 279         DestReceiver *dest;
 280 } TupOutputState;
 281
 282 extern TupOutputState *begin_tup_output_tupdesc(DestReceiver *dest,
 283                                                  TupleDesc tupdesc);
 284 extern void do_tup_output(TupOutputState *tstate, Datum *values, bool *isnull);
 285 extern void do_text_output_multiline(TupOutputState *tstate, char *text);
 286 extern void end_tup_output(TupOutputState *tstate);
 287
 288 /*
 289  * Write a single line of text given as a C string.
 290  *
 291  * Should only be used with a single-TEXT-attribute tupdesc.
 292  */
 293 #define do_text_output_oneline(tstate, str_to_emit) \
 294         do { \
 295                 Datum   values_[1]; \
 296                 bool    isnull_[1]; \
 297                 values_[0] = PointerGetDatum(cstring_to_text(str_to_emit)); \
 298                 isnull_[0] = false; \
 299                 do_tup_output(tstate, values_, isnull_); \
 300                 pfree(DatumGetPointer(values_[0])); \
 301         } while (0)
 302
 303
 304 /*
 305  * prototypes from functions in execUtils.c
 306  */
 307 extern EState *CreateExecutorState(void);
 308 extern void FreeExecutorState(EState *estate);
 309 extern ExprContext *CreateExprContext(EState *estate);
 310 extern ExprContext *CreateStandaloneExprContext(void);
 311 extern void FreeExprContext(ExprContext *econtext, bool isCommit);
 312 extern void ReScanExprContext(ExprContext *econtext);
 313
 314 #define ResetExprContext(econtext) \
 315         MemoryContextReset((econtext)->ecxt_per_tuple_memory)
 316
 317 extern ExprContext *MakePerTupleExprContext(EState *estate);
 318
 319 /* Get an EState's per-output-tuple exprcontext, making it if first use */
 320 #define GetPerTupleExprContext(estate) \
 321         ((estate)->es_per_tuple_exprcontext ? \
 322          (estate)->es_per_tuple_exprcontext : \
 323          MakePerTupleExprContext(estate))
 324
 325 #define GetPerTupleMemoryContext(estate) \
 326         (GetPerTupleExprContext(estate)->ecxt_per_tuple_memory)
 327
 328 /* Reset an EState's per-output-tuple exprcontext, if one's been created */
 329 #define ResetPerTupleExprContext(estate) \
 330         do { \
 331                 if ((estate)->es_per_tuple_exprcontext) \
 332                         ResetExprContext((estate)->es_per_tuple_exprcontext); \
 333         } while (0)
 334
 335 extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
 336 extern void ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc);
 337 extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 338 extern TupleDesc ExecGetResultType(PlanState *planstate);
 339 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
 340                                                 ExprContext *econtext,
 341                                                 TupleTableSlot *slot,
 342                                                 TupleDesc inputDesc);
 343 extern void ExecAssignProjectionInfo(PlanState *planstate,
 344                                                  TupleDesc inputDesc);
 345 extern void ExecFreeExprContext(PlanState *planstate);
 346 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 347 extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
 348 extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
 349
 350 extern bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid);
 351
 352 extern Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags);
 353 extern void ExecCloseScanRelation(Relation scanrel);
 354
 355 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 356 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 357 extern List *ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
 358                                           EState *estate);
 359 extern bool check_exclusion_constraint(Relation heap, Relation index,
 360                                                    IndexInfo *indexInfo,
 361                                                    ItemPointer tupleid,
 362                                                    Datum *values, bool *isnull,
 363                                                    EState *estate,
 364                                                    bool newIndex, bool errorOK);
 365
 366 extern void RegisterExprContextCallback(ExprContext *econtext,
 367                                                         ExprContextCallbackFunction function,
 368                                                         Datum arg);
 369 extern void UnregisterExprContextCallback(ExprContext *econtext,
 370                                                           ExprContextCallbackFunction function,
 371                                                           Datum arg);
 372
 373 #endif   /* EXECUTOR_H  */