src/include/nodes/execnodes.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * execnodes.h
   4  *        definitions for executor state nodes
   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 EXECNODES_H
  15 #define EXECNODES_H
  16
  17 #include "access/genam.h"
  18 #include "access/heapam.h"
  19 #include "access/skey.h"
  20 #include "nodes/params.h"
  21 #include "nodes/plannodes.h"
  22 #include "nodes/tidbitmap.h"
  23 #include "utils/hsearch.h"
  24 #include "utils/rel.h"
  25 #include "utils/snapshot.h"
  26 #include "utils/tuplestore.h"
  27
  28
  29 /* ----------------
  30  *        IndexInfo information
  31  *
  32  *              this struct holds the information needed to construct new index
  33  *              entries for a particular index.  Used for both index_build and
  34  *              retail creation of index entries.
  35  *
  36  *              NumIndexAttrs           number of columns in this index
  37  *              KeyAttrNumbers          underlying-rel attribute numbers used as keys
  38  *                                                      (zeroes indicate expressions)
  39  *              Expressions                     expr trees for expression entries, or NIL if none
  40  *              ExpressionsState        exec state for expressions, or NIL if none
  41  *              Predicate                       partial-index predicate, or NIL if none
  42  *              PredicateState          exec state for predicate, or NIL if none
  43  *              Unique                          is it a unique index?
  44  *              ReadyForInserts         is it valid for inserts?
  45  *              Concurrent                      are we doing a concurrent index build?
  46  *              BrokenHotChain          did we detect any broken HOT chains?
  47  *
  48  * ii_Concurrent and ii_BrokenHotChain are used only during index build;
  49  * they're conventionally set to false otherwise.
  50  * ----------------
  51  */
  52 typedef struct IndexInfo
  53 {
  54         NodeTag         type;
  55         int                     ii_NumIndexAttrs;
  56         AttrNumber      ii_KeyAttrNumbers[INDEX_MAX_KEYS];
  57         List       *ii_Expressions; /* list of Expr */
  58         List       *ii_ExpressionsState;        /* list of ExprState */
  59         List       *ii_Predicate;       /* list of Expr */
  60         List       *ii_PredicateState;          /* list of ExprState */
  61         bool            ii_Unique;
  62         bool            ii_ReadyForInserts;
  63         bool            ii_Concurrent;
  64         bool            ii_BrokenHotChain;
  65 } IndexInfo;
  66
  67 /* ----------------
  68  *        ExprContext_CB
  69  *
  70  *              List of callbacks to be called at ExprContext shutdown.
  71  * ----------------
  72  */
  73 typedef void (*ExprContextCallbackFunction) (Datum arg);
  74
  75 typedef struct ExprContext_CB
  76 {
  77         struct ExprContext_CB *next;
  78         ExprContextCallbackFunction function;
  79         Datum           arg;
  80 } ExprContext_CB;
  81
  82 /* ----------------
  83  *        ExprContext
  84  *
  85  *              This class holds the "current context" information
  86  *              needed to evaluate expressions for doing tuple qualifications
  87  *              and tuple projections.  For example, if an expression refers
  88  *              to an attribute in the current inner tuple then we need to know
  89  *              what the current inner tuple is and so we look at the expression
  90  *              context.
  91  *
  92  *      There are two memory contexts associated with an ExprContext:
  93  *      * ecxt_per_query_memory is a query-lifespan context, typically the same
  94  *        context the ExprContext node itself is allocated in.  This context
  95  *        can be used for purposes such as storing function call cache info.
  96  *      * ecxt_per_tuple_memory is a short-term context for expression results.
  97  *        As the name suggests, it will typically be reset once per tuple,
  98  *        before we begin to evaluate expressions for that tuple.  Each
  99  *        ExprContext normally has its very own per-tuple memory context.
 100  *
 101  *      CurrentMemoryContext should be set to ecxt_per_tuple_memory before
 102  *      calling ExecEvalExpr() --- see ExecEvalExprSwitchContext().
 103  * ----------------
 104  */
 105 typedef struct ExprContext
 106 {
 107         NodeTag         type;
 108
 109         /* Tuples that Var nodes in expression may refer to */
 110         TupleTableSlot *ecxt_scantuple;
 111         TupleTableSlot *ecxt_innertuple;
 112         TupleTableSlot *ecxt_outertuple;
 113
 114         /* Memory contexts for expression evaluation --- see notes above */
 115         MemoryContext ecxt_per_query_memory;
 116         MemoryContext ecxt_per_tuple_memory;
 117
 118         /* Values to substitute for Param nodes in expression */
 119         ParamExecData *ecxt_param_exec_vals;            /* for PARAM_EXEC params */
 120         ParamListInfo ecxt_param_list_info; /* for other param types */
 121
 122         /*
 123          * Values to substitute for Aggref nodes in the expressions of an Agg
 124          * node, or for WindowFunc nodes within a WindowAgg node.
 125          */
 126         Datum      *ecxt_aggvalues; /* precomputed values for aggs/windowfuncs */
 127         bool       *ecxt_aggnulls;      /* null flags for aggs/windowfuncs */
 128
 129         /* Value to substitute for CaseTestExpr nodes in expression */
 130         Datum           caseValue_datum;
 131         bool            caseValue_isNull;
 132
 133         /* Value to substitute for CoerceToDomainValue nodes in expression */
 134         Datum           domainValue_datum;
 135         bool            domainValue_isNull;
 136
 137         /* Link to containing EState (NULL if a standalone ExprContext) */
 138         struct EState *ecxt_estate;
 139
 140         /* Functions to call back when ExprContext is shut down */
 141         ExprContext_CB *ecxt_callbacks;
 142 } ExprContext;
 143
 144 /*
 145  * Set-result status returned by ExecEvalExpr()
 146  */
 147 typedef enum
 148 {
 149         ExprSingleResult,                       /* expression does not return a set */
 150         ExprMultipleResult,                     /* this result is an element of a set */
 151         ExprEndResult                           /* there are no more elements in the set */
 152 } ExprDoneCond;
 153
 154 /*
 155  * Return modes for functions returning sets.  Note values must be chosen
 156  * as separate bits so that a bitmask can be formed to indicate supported
 157  * modes.  SFRM_Materialize_Random and SFRM_Materialize_Preferred are
 158  * auxiliary flags about SFRM_Materialize mode, rather than separate modes.
 159  */
 160 typedef enum
 161 {
 162         SFRM_ValuePerCall = 0x01,       /* one value returned per call */
 163         SFRM_Materialize = 0x02,        /* result set instantiated in Tuplestore */
 164         SFRM_Materialize_Random = 0x04,         /* Tuplestore needs randomAccess */
 165         SFRM_Materialize_Preferred = 0x08       /* caller prefers Tuplestore */
 166 } SetFunctionReturnMode;
 167
 168 /*
 169  * When calling a function that might return a set (multiple rows),
 170  * a node of this type is passed as fcinfo->resultinfo to allow
 171  * return status to be passed back.  A function returning set should
 172  * raise an error if no such resultinfo is provided.
 173  */
 174 typedef struct ReturnSetInfo
 175 {
 176         NodeTag         type;
 177         /* values set by caller: */
 178         ExprContext *econtext;          /* context function is being called in */
 179         TupleDesc       expectedDesc;   /* tuple descriptor expected by caller */
 180         int                     allowedModes;   /* bitmask: return modes caller can handle */
 181         /* result status from function (but pre-initialized by caller): */
 182         SetFunctionReturnMode returnMode;       /* actual return mode */
 183         ExprDoneCond isDone;            /* status for ValuePerCall mode */
 184         /* fields filled by function in Materialize return mode: */
 185         Tuplestorestate *setResult; /* holds the complete returned tuple set */
 186         TupleDesc       setDesc;                /* actual descriptor for returned tuples */
 187 } ReturnSetInfo;
 188
 189 /* ----------------
 190  *              ProjectionInfo node information
 191  *
 192  *              This is all the information needed to perform projections ---
 193  *              that is, form new tuples by evaluation of targetlist expressions.
 194  *              Nodes which need to do projections create one of these.
 195  *
 196  *              ExecProject() evaluates the tlist, forms a tuple, and stores it
 197  *              in the given slot.      Note that the result will be a "virtual" tuple
 198  *              unless ExecMaterializeSlot() is then called to force it to be
 199  *              converted to a physical tuple.  The slot must have a tupledesc
 200  *              that matches the output of the tlist!
 201  *
 202  *              The planner very often produces tlists that consist entirely of
 203  *              simple Var references (lower levels of a plan tree almost always
 204  *              look like that).  And top-level tlists are often mostly Vars too.
 205  *              We therefore optimize execution of simple-Var tlist entries.
 206  *              The pi_targetlist list actually contains only the tlist entries that
 207  *              aren't simple Vars, while those that are Vars are processed using the
 208  *              varSlotOffsets/varNumbers/varOutputCols arrays.
 209  *
 210  *              The lastXXXVar fields are used to optimize fetching of fields from
 211  *              input tuples: they let us do a slot_getsomeattrs() call to ensure
 212  *              that all needed attributes are extracted in one pass.
 213  *
 214  *              targetlist              target list for projection (non-Var expressions only)
 215  *              exprContext             expression context in which to evaluate targetlist
 216  *              slot                    slot to place projection result in
 217  *              itemIsDone              workspace array for ExecProject
 218  *              directMap               true if varOutputCols[] is an identity map
 219  *              numSimpleVars   number of simple Vars found in original tlist
 220  *              varSlotOffsets  array indicating which slot each simple Var is from
 221  *              varNumbers              array containing input attr numbers of simple Vars
 222  *              varOutputCols   array containing output attr numbers of simple Vars
 223  *              lastInnerVar    highest attnum from inner tuple slot (0 if none)
 224  *              lastOuterVar    highest attnum from outer tuple slot (0 if none)
 225  *              lastScanVar             highest attnum from scan tuple slot (0 if none)
 226  * ----------------
 227  */
 228 typedef struct ProjectionInfo
 229 {
 230         NodeTag         type;
 231         List       *pi_targetlist;
 232         ExprContext *pi_exprContext;
 233         TupleTableSlot *pi_slot;
 234         ExprDoneCond *pi_itemIsDone;
 235         bool            pi_directMap;
 236         int                     pi_numSimpleVars;
 237         int                *pi_varSlotOffsets;
 238         int                *pi_varNumbers;
 239         int                *pi_varOutputCols;
 240         int                     pi_lastInnerVar;
 241         int                     pi_lastOuterVar;
 242         int                     pi_lastScanVar;
 243 } ProjectionInfo;
 244
 245 /* ----------------
 246  *        JunkFilter
 247  *
 248  *        This class is used to store information regarding junk attributes.
 249  *        A junk attribute is an attribute in a tuple that is needed only for
 250  *        storing intermediate information in the executor, and does not belong
 251  *        in emitted tuples.  For example, when we do an UPDATE query,
 252  *        the planner adds a "junk" entry to the targetlist so that the tuples
 253  *        returned to ExecutePlan() contain an extra attribute: the ctid of
 254  *        the tuple to be updated.      This is needed to do the update, but we
 255  *        don't want the ctid to be part of the stored new tuple!  So, we
 256  *        apply a "junk filter" to remove the junk attributes and form the
 257  *        real output tuple.  The junkfilter code also provides routines to
 258  *        extract the values of the junk attribute(s) from the input tuple.
 259  *
 260  *        targetList:           the original target list (including junk attributes).
 261  *        cleanTupType:         the tuple descriptor for the "clean" tuple (with
 262  *                                              junk attributes removed).
 263  *        cleanMap:                     A map with the correspondence between the non-junk
 264  *                                              attribute numbers of the "original" tuple and the
 265  *                                              attribute numbers of the "clean" tuple.
 266  *        resultSlot:           tuple slot used to hold cleaned tuple.
 267  *        junkAttNo:            not used by junkfilter code.  Can be used by caller
 268  *                                              to remember the attno of a specific junk attribute
 269  *                                              (execMain.c stores the "ctid" attno here).
 270  * ----------------
 271  */
 272 typedef struct JunkFilter
 273 {
 274         NodeTag         type;
 275         List       *jf_targetList;
 276         TupleDesc       jf_cleanTupType;
 277         AttrNumber *jf_cleanMap;
 278         TupleTableSlot *jf_resultSlot;
 279         AttrNumber      jf_junkAttNo;
 280 } JunkFilter;
 281
 282 /* ----------------
 283  *        ResultRelInfo information
 284  *
 285  *              Whenever we update an existing relation, we have to
 286  *              update indices on the relation, and perhaps also fire triggers.
 287  *              The ResultRelInfo class is used to hold all the information needed
 288  *              about a result relation, including indices.. -cim 10/15/89
 289  *
 290  *              RangeTableIndex                 result relation's range table index
 291  *              RelationDesc                    relation descriptor for result relation
 292  *              NumIndices                              # of indices existing on result relation
 293  *              IndexRelationDescs              array of relation descriptors for indices
 294  *              IndexRelationInfo               array of key/attr info for indices
 295  *              TrigDesc                                triggers to be fired, if any
 296  *              TrigFunctions                   cached lookup info for trigger functions
 297  *              TrigInstrument                  optional runtime measurements for triggers
 298  *              ConstraintExprs                 array of constraint-checking expr states
 299  *              junkFilter                              for removing junk attributes from tuples
 300  *              projectReturning                for computing a RETURNING list
 301  * ----------------
 302  */
 303 typedef struct ResultRelInfo
 304 {
 305         NodeTag         type;
 306         Index           ri_RangeTableIndex;
 307         Relation        ri_RelationDesc;
 308         int                     ri_NumIndices;
 309         RelationPtr ri_IndexRelationDescs;
 310         IndexInfo **ri_IndexRelationInfo;
 311         TriggerDesc *ri_TrigDesc;
 312         FmgrInfo   *ri_TrigFunctions;
 313         struct Instrumentation *ri_TrigInstrument;
 314         List      **ri_ConstraintExprs;
 315         JunkFilter *ri_junkFilter;
 316         ProjectionInfo *ri_projectReturning;
 317 } ResultRelInfo;
 318
 319 /* ----------------
 320  *        EState information
 321  *
 322  * Master working state for an Executor invocation
 323  * ----------------
 324  */
 325 typedef struct EState
 326 {
 327         NodeTag         type;
 328
 329         /* Basic state for all query types: */
 330         ScanDirection es_direction; /* current scan direction */
 331         Snapshot        es_snapshot;    /* time qual to use */
 332         Snapshot        es_crosscheck_snapshot; /* crosscheck time qual for RI */
 333         List       *es_range_table; /* List of RangeTblEntry */
 334
 335         /* If query can insert/delete tuples, the command ID to mark them with */
 336         CommandId       es_output_cid;
 337
 338         /* Info about target table for insert/update/delete queries: */
 339         ResultRelInfo *es_result_relations; /* array of ResultRelInfos */
 340         int                     es_num_result_relations;                /* length of array */
 341         ResultRelInfo *es_result_relation_info;         /* currently active array elt */
 342         JunkFilter *es_junkFilter;      /* currently active junk filter */
 343
 344         /* Stuff used for firing triggers: */
 345         List       *es_trig_target_relations;           /* trigger-only ResultRelInfos */
 346         TupleTableSlot *es_trig_tuple_slot; /* for trigger output tuples */
 347
 348         /* Parameter info: */
 349         ParamListInfo es_param_list_info;       /* values of external params */
 350         ParamExecData *es_param_exec_vals;      /* values of internal params */
 351
 352         /* Other working state: */
 353         MemoryContext es_query_cxt; /* per-query context in which EState lives */
 354
 355         TupleTable      es_tupleTable;  /* Array of TupleTableSlots */
 356
 357         uint32          es_processed;   /* # of tuples processed */
 358         Oid                     es_lastoid;             /* last oid processed (by INSERT) */
 359         List       *es_rowMarks;        /* not good place, but there is no other */
 360
 361         bool            es_instrument;  /* true requests runtime instrumentation */
 362         bool            es_select_into; /* true if doing SELECT INTO */
 363         bool            es_into_oids;   /* true to generate OIDs in SELECT INTO */
 364
 365         List       *es_exprcontexts;    /* List of ExprContexts within EState */
 366
 367         List       *es_subplanstates;           /* List of PlanState for SubPlans */
 368
 369         /*
 370          * this ExprContext is for per-output-tuple operations, such as constraint
 371          * checks and index-value computations.  It will be reset for each output
 372          * tuple.  Note that it will be created only if needed.
 373          */
 374         ExprContext *es_per_tuple_exprcontext;
 375
 376         /* Below is to re-evaluate plan qual in READ COMMITTED mode */
 377         PlannedStmt *es_plannedstmt;    /* link to top of plan tree */
 378         struct evalPlanQual *es_evalPlanQual;           /* chain of PlanQual states */
 379         bool       *es_evTupleNull; /* local array of EPQ status */
 380         HeapTuple  *es_evTuple;         /* shared array of EPQ substitute tuples */
 381         bool            es_useEvalPlan; /* evaluating EPQ tuples? */
 382 } EState;
 383
 384
 385 /*
 386  * es_rowMarks is a list of these structs.      See RowMarkClause for details
 387  * about rti and prti.  toidAttno is not used in a "plain" rowmark.
 388  */
 389 typedef struct ExecRowMark
 390 {
 391         Relation        relation;               /* opened and RowShareLock'd relation */
 392         Index           rti;                    /* its range table index */
 393         Index           prti;                   /* parent range table index, if child */
 394         bool            forUpdate;              /* true = FOR UPDATE, false = FOR SHARE */
 395         bool            noWait;                 /* NOWAIT option */
 396         AttrNumber      ctidAttNo;              /* resno of its ctid junk attribute */
 397         AttrNumber      toidAttNo;              /* resno of tableoid junk attribute, if any */
 398         ItemPointerData curCtid;        /* ctid of currently locked tuple, if any */
 399 } ExecRowMark;
 400
 401
 402 /* ----------------------------------------------------------------
 403  *                               Tuple Hash Tables
 404  *
 405  * All-in-memory tuple hash tables are used for a number of purposes.
 406  *
 407  * Note: tab_hash_funcs are for the key datatype(s) stored in the table,
 408  * and tab_eq_funcs are non-cross-type equality operators for those types.
 409  * Normally these are the only functions used, but FindTupleHashEntry()
 410  * supports searching a hashtable using cross-data-type hashing.  For that,
 411  * the caller must supply hash functions for the LHS datatype as well as
 412  * the cross-type equality operators to use.  in_hash_funcs and cur_eq_funcs
 413  * are set to point to the caller's function arrays while doing such a search.
 414  * During LookupTupleHashEntry(), they point to tab_hash_funcs and
 415  * tab_eq_funcs respectively.
 416  * ----------------------------------------------------------------
 417  */
 418 typedef struct TupleHashEntryData *TupleHashEntry;
 419 typedef struct TupleHashTableData *TupleHashTable;
 420
 421 typedef struct TupleHashEntryData
 422 {
 423         /* firstTuple must be the first field in this struct! */
 424         MinimalTuple firstTuple;        /* copy of first tuple in this group */
 425         /* there may be additional data beyond the end of this struct */
 426 } TupleHashEntryData;                   /* VARIABLE LENGTH STRUCT */
 427
 428 typedef struct TupleHashTableData
 429 {
 430         HTAB       *hashtab;            /* underlying dynahash table */
 431         int                     numCols;                /* number of columns in lookup key */
 432         AttrNumber *keyColIdx;          /* attr numbers of key columns */
 433         FmgrInfo   *tab_hash_funcs; /* hash functions for table datatype(s) */
 434         FmgrInfo   *tab_eq_funcs;       /* equality functions for table datatype(s) */
 435         MemoryContext tablecxt;         /* memory context containing table */
 436         MemoryContext tempcxt;          /* context for function evaluations */
 437         Size            entrysize;              /* actual size to make each hash entry */
 438         TupleTableSlot *tableslot;      /* slot for referencing table entries */
 439         /* The following fields are set transiently for each table search: */
 440         TupleTableSlot *inputslot;      /* current input tuple's slot */
 441         FmgrInfo   *in_hash_funcs;      /* hash functions for input datatype(s) */
 442         FmgrInfo   *cur_eq_funcs;       /* equality functions for input vs. table */
 443 } TupleHashTableData;
 444
 445 typedef HASH_SEQ_STATUS TupleHashIterator;
 446
 447 /*
 448  * Use InitTupleHashIterator/TermTupleHashIterator for a read/write scan.
 449  * Use ResetTupleHashIterator if the table can be frozen (in this case no
 450  * explicit scan termination is needed).
 451  */
 452 #define InitTupleHashIterator(htable, iter) \
 453         hash_seq_init(iter, (htable)->hashtab)
 454 #define TermTupleHashIterator(iter) \
 455         hash_seq_term(iter)
 456 #define ResetTupleHashIterator(htable, iter) \
 457         do { \
 458                 hash_freeze((htable)->hashtab); \
 459                 hash_seq_init(iter, (htable)->hashtab); \
 460         } while (0)
 461 #define ScanTupleHashTable(iter) \
 462         ((TupleHashEntry) hash_seq_search(iter))
 463
 464
 465 /* ----------------------------------------------------------------
 466  *                               Expression State Trees
 467  *
 468  * Each executable expression tree has a parallel ExprState tree.
 469  *
 470  * Unlike PlanState, there is not an exact one-for-one correspondence between
 471  * ExprState node types and Expr node types.  Many Expr node types have no
 472  * need for node-type-specific run-time state, and so they can use plain
 473  * ExprState or GenericExprState as their associated ExprState node type.
 474  * ----------------------------------------------------------------
 475  */
 476
 477 /* ----------------
 478  *              ExprState node
 479  *
 480  * ExprState is the common superclass for all ExprState-type nodes.
 481  *
 482  * It can also be instantiated directly for leaf Expr nodes that need no
 483  * local run-time state (such as Var, Const, or Param).
 484  *
 485  * To save on dispatch overhead, each ExprState node contains a function
 486  * pointer to the routine to execute to evaluate the node.
 487  * ----------------
 488  */
 489
 490 typedef struct ExprState ExprState;
 491
 492 typedef Datum (*ExprStateEvalFunc) (ExprState *expression,
 493                                                                                                 ExprContext *econtext,
 494                                                                                                 bool *isNull,
 495                                                                                                 ExprDoneCond *isDone);
 496
 497 struct ExprState
 498 {
 499         NodeTag         type;
 500         Expr       *expr;                       /* associated Expr node */
 501         ExprStateEvalFunc evalfunc; /* routine to run to execute node */
 502 };
 503
 504 /* ----------------
 505  *              GenericExprState node
 506  *
 507  * This is used for Expr node types that need no local run-time state,
 508  * but have one child Expr node.
 509  * ----------------
 510  */
 511 typedef struct GenericExprState
 512 {
 513         ExprState       xprstate;
 514         ExprState  *arg;                        /* state of my child node */
 515 } GenericExprState;
 516
 517 /* ----------------
 518  *              AggrefExprState node
 519  * ----------------
 520  */
 521 typedef struct AggrefExprState
 522 {
 523         ExprState       xprstate;
 524         List       *args;                       /* states of argument expressions */
 525         int                     aggno;                  /* ID number for agg within its plan node */
 526 } AggrefExprState;
 527
 528 /* ----------------
 529  *              WindowFuncExprState node
 530  * ----------------
 531  */
 532 typedef struct WindowFuncExprState
 533 {
 534         ExprState       xprstate;
 535         List       *args;                       /* states of argument expressions */
 536         int                     wfuncno;                /* ID number for wfunc within its plan node */
 537 } WindowFuncExprState;
 538
 539 /* ----------------
 540  *              ArrayRefExprState node
 541  *
 542  * Note: array types can be fixed-length (typlen > 0), but only when the
 543  * element type is itself fixed-length.  Otherwise they are varlena structures
 544  * and have typlen = -1.  In any case, an array type is never pass-by-value.
 545  * ----------------
 546  */
 547 typedef struct ArrayRefExprState
 548 {
 549         ExprState       xprstate;
 550         List       *refupperindexpr;    /* states for child nodes */
 551         List       *reflowerindexpr;
 552         ExprState  *refexpr;
 553         ExprState  *refassgnexpr;
 554         int16           refattrlength;  /* typlen of array type */
 555         int16           refelemlength;  /* typlen of the array element type */
 556         bool            refelembyval;   /* is the element type pass-by-value? */
 557         char            refelemalign;   /* typalign of the element type */
 558 } ArrayRefExprState;
 559
 560 /* ----------------
 561  *              FuncExprState node
 562  *
 563  * Although named for FuncExpr, this is also used for OpExpr, DistinctExpr,
 564  * and NullIf nodes; be careful to check what xprstate.expr is actually
 565  * pointing at!
 566  * ----------------
 567  */
 568 typedef struct FuncExprState
 569 {
 570         ExprState       xprstate;
 571         List       *args;                       /* states of argument expressions */
 572
 573         /*
 574          * Function manager's lookup info for the target function.  If func.fn_oid
 575          * is InvalidOid, we haven't initialized it yet (nor any of the following
 576          * fields).
 577          */
 578         FmgrInfo        func;
 579
 580         /*
 581          * For a set-returning function (SRF) that returns a tuplestore, we keep
 582          * the tuplestore here and dole out the result rows one at a time. The
 583          * slot holds the row currently being returned.
 584          */
 585         Tuplestorestate *funcResultStore;
 586         TupleTableSlot *funcResultSlot;
 587
 588         /*
 589          * In some cases we need to compute a tuple descriptor for the function's
 590          * output.      If so, it's stored here.
 591          */
 592         TupleDesc       funcResultDesc;
 593         bool            funcReturnsTuple;               /* valid when funcResultDesc isn't
 594                                                                                  * NULL */
 595
 596         /*
 597          * We need to store argument values across calls when evaluating a SRF
 598          * that uses value-per-call mode.
 599          *
 600          * setArgsValid is true when we are evaluating a set-valued function and
 601          * we are in the middle of a call series; we want to pass the same
 602          * argument values to the function again (and again, until it returns
 603          * ExprEndResult).
 604          */
 605         bool            setArgsValid;
 606
 607         /*
 608          * Flag to remember whether we found a set-valued argument to the
 609          * function. This causes the function result to be a set as well. Valid
 610          * only when setArgsValid is true or funcResultStore isn't NULL.
 611          */
 612         bool            setHasSetArg;   /* some argument returns a set */
 613
 614         /*
 615          * Flag to remember whether we have registered a shutdown callback for
 616          * this FuncExprState.  We do so only if funcResultStore or setArgsValid
 617          * has been set at least once (since all the callback is for is to release
 618          * the tuplestore or clear setArgsValid).
 619          */
 620         bool            shutdown_reg;   /* a shutdown callback is registered */
 621
 622         /*
 623          * Current argument data for a set-valued function; contains valid data
 624          * only if setArgsValid is true.
 625          */
 626         FunctionCallInfoData setArgs;
 627 } FuncExprState;
 628
 629 /* ----------------
 630  *              ScalarArrayOpExprState node
 631  *
 632  * This is a FuncExprState plus some additional data.
 633  * ----------------
 634  */
 635 typedef struct ScalarArrayOpExprState
 636 {
 637         FuncExprState fxprstate;
 638         /* Cached info about array element type */
 639         Oid                     element_type;
 640         int16           typlen;
 641         bool            typbyval;
 642         char            typalign;
 643 } ScalarArrayOpExprState;
 644
 645 /* ----------------
 646  *              BoolExprState node
 647  * ----------------
 648  */
 649 typedef struct BoolExprState
 650 {
 651         ExprState       xprstate;
 652         List       *args;                       /* states of argument expression(s) */
 653 } BoolExprState;
 654
 655 /* ----------------
 656  *              SubPlanState node
 657  * ----------------
 658  */
 659 typedef struct SubPlanState
 660 {
 661         ExprState       xprstate;
 662         struct PlanState *planstate;    /* subselect plan's state tree */
 663         ExprState  *testexpr;           /* state of combining expression */
 664         List       *args;                       /* states of argument expression(s) */
 665         HeapTuple       curTuple;               /* copy of most recent tuple from subplan */
 666         /* these are used when hashing the subselect's output: */
 667         ProjectionInfo *projLeft;       /* for projecting lefthand exprs */
 668         ProjectionInfo *projRight;      /* for projecting subselect output */
 669         TupleHashTable hashtable;       /* hash table for no-nulls subselect rows */
 670         TupleHashTable hashnulls;       /* hash table for rows with null(s) */
 671         bool            havehashrows;   /* TRUE if hashtable is not empty */
 672         bool            havenullrows;   /* TRUE if hashnulls is not empty */
 673         MemoryContext tablecxt;         /* memory context containing tables */
 674         ExprContext *innerecontext; /* working context for comparisons */
 675         AttrNumber *keyColIdx;          /* control data for hash tables */
 676         FmgrInfo   *tab_hash_funcs; /* hash functions for table datatype(s) */
 677         FmgrInfo   *tab_eq_funcs;       /* equality functions for table datatype(s) */
 678         FmgrInfo   *lhs_hash_funcs; /* hash functions for lefthand datatype(s) */
 679         FmgrInfo   *cur_eq_funcs;       /* equality functions for LHS vs. table */
 680 } SubPlanState;
 681
 682 /* ----------------
 683  *              AlternativeSubPlanState node
 684  * ----------------
 685  */
 686 typedef struct AlternativeSubPlanState
 687 {
 688         ExprState       xprstate;
 689         List       *subplans;           /* states of alternative subplans */
 690         int                     active;                 /* list index of the one we're using */
 691 } AlternativeSubPlanState;
 692
 693 /* ----------------
 694  *              FieldSelectState node
 695  * ----------------
 696  */
 697 typedef struct FieldSelectState
 698 {
 699         ExprState       xprstate;
 700         ExprState  *arg;                        /* input expression */
 701         TupleDesc       argdesc;                /* tupdesc for most recent input */
 702 } FieldSelectState;
 703
 704 /* ----------------
 705  *              FieldStoreState node
 706  * ----------------
 707  */
 708 typedef struct FieldStoreState
 709 {
 710         ExprState       xprstate;
 711         ExprState  *arg;                        /* input tuple value */
 712         List       *newvals;            /* new value(s) for field(s) */
 713         TupleDesc       argdesc;                /* tupdesc for most recent input */
 714 } FieldStoreState;
 715
 716 /* ----------------
 717  *              CoerceViaIOState node
 718  * ----------------
 719  */
 720 typedef struct CoerceViaIOState
 721 {
 722         ExprState       xprstate;
 723         ExprState  *arg;                        /* input expression */
 724         FmgrInfo        outfunc;                /* lookup info for source output function */
 725         FmgrInfo        infunc;                 /* lookup info for result input function */
 726         Oid                     intypioparam;   /* argument needed for input function */
 727 } CoerceViaIOState;
 728
 729 /* ----------------
 730  *              ArrayCoerceExprState node
 731  * ----------------
 732  */
 733 typedef struct ArrayCoerceExprState
 734 {
 735         ExprState       xprstate;
 736         ExprState  *arg;                        /* input array value */
 737         Oid                     resultelemtype; /* element type of result array */
 738         FmgrInfo        elemfunc;               /* lookup info for element coercion function */
 739         /* use struct pointer to avoid including array.h here */
 740         struct ArrayMapState *amstate;          /* workspace for array_map */
 741 } ArrayCoerceExprState;
 742
 743 /* ----------------
 744  *              ConvertRowtypeExprState node
 745  * ----------------
 746  */
 747 typedef struct ConvertRowtypeExprState
 748 {
 749         ExprState       xprstate;
 750         ExprState  *arg;                        /* input tuple value */
 751         TupleDesc       indesc;                 /* tupdesc for source rowtype */
 752         TupleDesc       outdesc;                /* tupdesc for result rowtype */
 753         AttrNumber *attrMap;            /* indexes of input fields, or 0 for null */
 754         Datum      *invalues;           /* workspace for deconstructing source */
 755         bool       *inisnull;
 756         Datum      *outvalues;          /* workspace for constructing result */
 757         bool       *outisnull;
 758 } ConvertRowtypeExprState;
 759
 760 /* ----------------
 761  *              CaseExprState node
 762  * ----------------
 763  */
 764 typedef struct CaseExprState
 765 {
 766         ExprState       xprstate;
 767         ExprState  *arg;                        /* implicit equality comparison argument */
 768         List       *args;                       /* the arguments (list of WHEN clauses) */
 769         ExprState  *defresult;          /* the default result (ELSE clause) */
 770 } CaseExprState;
 771
 772 /* ----------------
 773  *              CaseWhenState node
 774  * ----------------
 775  */
 776 typedef struct CaseWhenState
 777 {
 778         ExprState       xprstate;
 779         ExprState  *expr;                       /* condition expression */
 780         ExprState  *result;                     /* substitution result */
 781 } CaseWhenState;
 782
 783 /* ----------------
 784  *              ArrayExprState node
 785  *
 786  * Note: ARRAY[] expressions always produce varlena arrays, never fixed-length
 787  * arrays.
 788  * ----------------
 789  */
 790 typedef struct ArrayExprState
 791 {
 792         ExprState       xprstate;
 793         List       *elements;           /* states for child nodes */
 794         int16           elemlength;             /* typlen of the array element type */
 795         bool            elembyval;              /* is the element type pass-by-value? */
 796         char            elemalign;              /* typalign of the element type */
 797 } ArrayExprState;
 798
 799 /* ----------------
 800  *              RowExprState node
 801  * ----------------
 802  */
 803 typedef struct RowExprState
 804 {
 805         ExprState       xprstate;
 806         List       *args;                       /* the arguments */
 807         TupleDesc       tupdesc;                /* descriptor for result tuples */
 808 } RowExprState;
 809
 810 /* ----------------
 811  *              RowCompareExprState node
 812  * ----------------
 813  */
 814 typedef struct RowCompareExprState
 815 {
 816         ExprState       xprstate;
 817         List       *largs;                      /* the left-hand input arguments */
 818         List       *rargs;                      /* the right-hand input arguments */
 819         FmgrInfo   *funcs;                      /* array of comparison function info */
 820 } RowCompareExprState;
 821
 822 /* ----------------
 823  *              CoalesceExprState node
 824  * ----------------
 825  */
 826 typedef struct CoalesceExprState
 827 {
 828         ExprState       xprstate;
 829         List       *args;                       /* the arguments */
 830 } CoalesceExprState;
 831
 832 /* ----------------
 833  *              MinMaxExprState node
 834  * ----------------
 835  */
 836 typedef struct MinMaxExprState
 837 {
 838         ExprState       xprstate;
 839         List       *args;                       /* the arguments */
 840         FmgrInfo        cfunc;                  /* lookup info for comparison func */
 841 } MinMaxExprState;
 842
 843 /* ----------------
 844  *              XmlExprState node
 845  * ----------------
 846  */
 847 typedef struct XmlExprState
 848 {
 849         ExprState       xprstate;
 850         List       *named_args;         /* ExprStates for named arguments */
 851         List       *args;                       /* ExprStates for other arguments */
 852 } XmlExprState;
 853
 854 /* ----------------
 855  *              NullTestState node
 856  * ----------------
 857  */
 858 typedef struct NullTestState
 859 {
 860         ExprState       xprstate;
 861         ExprState  *arg;                        /* input expression */
 862         bool            argisrow;               /* T if input is of a composite type */
 863         /* used only if argisrow: */
 864         TupleDesc       argdesc;                /* tupdesc for most recent input */
 865 } NullTestState;
 866
 867 /* ----------------
 868  *              CoerceToDomainState node
 869  * ----------------
 870  */
 871 typedef struct CoerceToDomainState
 872 {
 873         ExprState       xprstate;
 874         ExprState  *arg;                        /* input expression */
 875         /* Cached list of constraints that need to be checked */
 876         List       *constraints;        /* list of DomainConstraintState nodes */
 877 } CoerceToDomainState;
 878
 879 /*
 880  * DomainConstraintState - one item to check during CoerceToDomain
 881  *
 882  * Note: this is just a Node, and not an ExprState, because it has no
 883  * corresponding Expr to link to.  Nonetheless it is part of an ExprState
 884  * tree, so we give it a name following the xxxState convention.
 885  */
 886 typedef enum DomainConstraintType
 887 {
 888         DOM_CONSTRAINT_NOTNULL,
 889         DOM_CONSTRAINT_CHECK
 890 } DomainConstraintType;
 891
 892 typedef struct DomainConstraintState
 893 {
 894         NodeTag         type;
 895         DomainConstraintType constrainttype;            /* constraint type */
 896         char       *name;                       /* name of constraint (for error msgs) */
 897         ExprState  *check_expr;         /* for CHECK, a boolean expression */
 898 } DomainConstraintState;
 899
 900
 901 /* ----------------------------------------------------------------
 902  *                               Executor State Trees
 903  *
 904  * An executing query has a PlanState tree paralleling the Plan tree
 905  * that describes the plan.
 906  * ----------------------------------------------------------------
 907  */
 908
 909 /* ----------------
 910  *              PlanState node
 911  *
 912  * We never actually instantiate any PlanState nodes; this is just the common
 913  * abstract superclass for all PlanState-type nodes.
 914  * ----------------
 915  */
 916 typedef struct PlanState
 917 {
 918         NodeTag         type;
 919
 920         Plan       *plan;                       /* associated Plan node */
 921
 922         EState     *state;                      /* at execution time, states of individual
 923                                                                  * nodes point to one EState for the whole
 924                                                                  * top-level plan */
 925
 926         struct Instrumentation *instrument; /* Optional runtime stats for this
 927                                                                                  * plan node */
 928
 929         /*
 930          * Common structural data for all Plan types.  These links to subsidiary
 931          * state trees parallel links in the associated plan tree (except for the
 932          * subPlan list, which does not exist in the plan tree).
 933          */
 934         List       *targetlist;         /* target list to be computed at this node */
 935         List       *qual;                       /* implicitly-ANDed qual conditions */
 936         struct PlanState *lefttree; /* input plan tree(s) */
 937         struct PlanState *righttree;
 938         List       *initPlan;           /* Init SubPlanState nodes (un-correlated expr
 939                                                                  * subselects) */
 940         List       *subPlan;            /* SubPlanState nodes in my expressions */
 941
 942         /*
 943          * State for management of parameter-change-driven rescanning
 944          */
 945         Bitmapset  *chgParam;           /* set of IDs of changed Params */
 946
 947         /*
 948          * Other run-time state needed by most if not all node types.
 949          */
 950         TupleTableSlot *ps_ResultTupleSlot; /* slot for my result tuples */
 951         ExprContext *ps_ExprContext;    /* node's expression-evaluation context */
 952         ProjectionInfo *ps_ProjInfo;    /* info for doing tuple projection */
 953         bool            ps_TupFromTlist;/* state flag for processing set-valued
 954                                                                  * functions in targetlist */
 955 } PlanState;
 956
 957 /* ----------------
 958  *      these are are defined to avoid confusion problems with "left"
 959  *      and "right" and "inner" and "outer".  The convention is that
 960  *      the "left" plan is the "outer" plan and the "right" plan is
 961  *      the inner plan, but these make the code more readable.
 962  * ----------------
 963  */
 964 #define innerPlanState(node)            (((PlanState *)(node))->righttree)
 965 #define outerPlanState(node)            (((PlanState *)(node))->lefttree)
 966
 967
 968 /* ----------------
 969  *       ResultState information
 970  * ----------------
 971  */
 972 typedef struct ResultState
 973 {
 974         PlanState       ps;                             /* its first field is NodeTag */
 975         ExprState  *resconstantqual;
 976         bool            rs_done;                /* are we done? */
 977         bool            rs_checkqual;   /* do we need to check the qual? */
 978 } ResultState;
 979
 980 /* ----------------
 981  *       AppendState information
 982  *
 983  *              nplans                  how many plans are in the list
 984  *              whichplan               which plan is being executed (0 .. n-1)
 985  *              firstplan               first plan to execute (usually 0)
 986  *              lastplan                last plan to execute (usually n-1)
 987  * ----------------
 988  */
 989 typedef struct AppendState
 990 {
 991         PlanState       ps;                             /* its first field is NodeTag */
 992         PlanState **appendplans;        /* array of PlanStates for my inputs */
 993         int                     as_nplans;
 994         int                     as_whichplan;
 995         int                     as_firstplan;
 996         int                     as_lastplan;
 997 } AppendState;
 998
 999 /* ----------------
1000  *       RecursiveUnionState information
1001  *
1002  *              RecursiveUnionState is used for performing a recursive union.
1003  *
1004  *              recursing                       T when we're done scanning the non-recursive term
1005  *              intermediate_empty      T if intermediate_table is currently empty
1006  *              working_table           working table (to be scanned by recursive term)
1007  *              intermediate_table      current recursive output (next generation of WT)
1008  * ----------------
1009  */
1010 typedef struct RecursiveUnionState
1011 {
1012         PlanState       ps;                             /* its first field is NodeTag */
1013         bool            recursing;
1014         bool            intermediate_empty;
1015         Tuplestorestate *working_table;
1016         Tuplestorestate *intermediate_table;
1017         /* Remaining fields are unused in UNION ALL case */
1018         FmgrInfo   *eqfunctions;        /* per-grouping-field equality fns */
1019         FmgrInfo   *hashfunctions;      /* per-grouping-field hash fns */
1020         MemoryContext tempContext;      /* short-term context for comparisons */
1021         TupleHashTable hashtable;       /* hash table for tuples already seen */
1022         MemoryContext tableContext; /* memory context containing hash table */
1023 } RecursiveUnionState;
1024
1025 /* ----------------
1026  *       BitmapAndState information
1027  * ----------------
1028  */
1029 typedef struct BitmapAndState
1030 {
1031         PlanState       ps;                             /* its first field is NodeTag */
1032         PlanState **bitmapplans;        /* array of PlanStates for my inputs */
1033         int                     nplans;                 /* number of input plans */
1034 } BitmapAndState;
1035
1036 /* ----------------
1037  *       BitmapOrState information
1038  * ----------------
1039  */
1040 typedef struct BitmapOrState
1041 {
1042         PlanState       ps;                             /* its first field is NodeTag */
1043         PlanState **bitmapplans;        /* array of PlanStates for my inputs */
1044         int                     nplans;                 /* number of input plans */
1045 } BitmapOrState;
1046
1047 /* ----------------------------------------------------------------
1048  *                               Scan State Information
1049  * ----------------------------------------------------------------
1050  */
1051
1052 /* ----------------
1053  *       ScanState information
1054  *
1055  *              ScanState extends PlanState for node types that represent
1056  *              scans of an underlying relation.  It can also be used for nodes
1057  *              that scan the output of an underlying plan node --- in that case,
1058  *              only ScanTupleSlot is actually useful, and it refers to the tuple
1059  *              retrieved from the subplan.
1060  *
1061  *              currentRelation    relation being scanned (NULL if none)
1062  *              currentScanDesc    current scan descriptor for scan (NULL if none)
1063  *              ScanTupleSlot      pointer to slot in tuple table holding scan tuple
1064  * ----------------
1065  */
1066 typedef struct ScanState
1067 {
1068         PlanState       ps;                             /* its first field is NodeTag */
1069         Relation        ss_currentRelation;
1070         HeapScanDesc ss_currentScanDesc;
1071         TupleTableSlot *ss_ScanTupleSlot;
1072 } ScanState;
1073
1074 /*
1075  * SeqScan uses a bare ScanState as its state node, since it needs
1076  * no additional fields.
1077  */
1078 typedef ScanState SeqScanState;
1079
1080 /*
1081  * These structs store information about index quals that don't have simple
1082  * constant right-hand sides.  See comments for ExecIndexBuildScanKeys()
1083  * for discussion.
1084  */
1085 typedef struct
1086 {
1087         ScanKey         scan_key;               /* scankey to put value into */
1088         ExprState  *key_expr;           /* expr to evaluate to get value */
1089 } IndexRuntimeKeyInfo;
1090
1091 typedef struct
1092 {
1093         ScanKey         scan_key;               /* scankey to put value into */
1094         ExprState  *array_expr;         /* expr to evaluate to get array value */
1095         int                     next_elem;              /* next array element to use */
1096         int                     num_elems;              /* number of elems in current array value */
1097         Datum      *elem_values;        /* array of num_elems Datums */
1098         bool       *elem_nulls;         /* array of num_elems is-null flags */
1099 } IndexArrayKeyInfo;
1100
1101 /* ----------------
1102  *       IndexScanState information
1103  *
1104  *              indexqualorig      execution state for indexqualorig expressions
1105  *              ScanKeys                   Skey structures to scan index rel
1106  *              NumScanKeys                number of Skey structs
1107  *              RuntimeKeys                info about Skeys that must be evaluated at runtime
1108  *              NumRuntimeKeys     number of RuntimeKeys structs
1109  *              RuntimeKeysReady   true if runtime Skeys have been computed
1110  *              RuntimeContext     expr context for evaling runtime Skeys
1111  *              RelationDesc       index relation descriptor
1112  *              ScanDesc                   index scan descriptor
1113  * ----------------
1114  */
1115 typedef struct IndexScanState
1116 {
1117         ScanState       ss;                             /* its first field is NodeTag */
1118         List       *indexqualorig;
1119         ScanKey         iss_ScanKeys;
1120         int                     iss_NumScanKeys;
1121         IndexRuntimeKeyInfo *iss_RuntimeKeys;
1122         int                     iss_NumRuntimeKeys;
1123         bool            iss_RuntimeKeysReady;
1124         ExprContext *iss_RuntimeContext;
1125         Relation        iss_RelationDesc;
1126         IndexScanDesc iss_ScanDesc;
1127 } IndexScanState;
1128
1129 /* ----------------
1130  *       BitmapIndexScanState information
1131  *
1132  *              result                     bitmap to return output into, or NULL
1133  *              ScanKeys                   Skey structures to scan index rel
1134  *              NumScanKeys                number of Skey structs
1135  *              RuntimeKeys                info about Skeys that must be evaluated at runtime
1136  *              NumRuntimeKeys     number of RuntimeKeys structs
1137  *              ArrayKeys                  info about Skeys that come from ScalarArrayOpExprs
1138  *              NumArrayKeys       number of ArrayKeys structs
1139  *              RuntimeKeysReady   true if runtime Skeys have been computed
1140  *              RuntimeContext     expr context for evaling runtime Skeys
1141  *              RelationDesc       index relation descriptor
1142  *              ScanDesc                   index scan descriptor
1143  * ----------------
1144  */
1145 typedef struct BitmapIndexScanState
1146 {
1147         ScanState       ss;                             /* its first field is NodeTag */
1148         TIDBitmap  *biss_result;
1149         ScanKey         biss_ScanKeys;
1150         int                     biss_NumScanKeys;
1151         IndexRuntimeKeyInfo *biss_RuntimeKeys;
1152         int                     biss_NumRuntimeKeys;
1153         IndexArrayKeyInfo *biss_ArrayKeys;
1154         int                     biss_NumArrayKeys;
1155         bool            biss_RuntimeKeysReady;
1156         ExprContext *biss_RuntimeContext;
1157         Relation        biss_RelationDesc;
1158         IndexScanDesc biss_ScanDesc;
1159 } BitmapIndexScanState;
1160
1161 /* ----------------
1162  *       BitmapHeapScanState information
1163  *
1164  *              bitmapqualorig     execution state for bitmapqualorig expressions
1165  *              tbm                                bitmap obtained from child index scan(s)
1166  *              tbmiterator                iterator for scanning current pages
1167  *              tbmres                     current-page data
1168  *              prefetch_iterator  iterator for prefetching ahead of current page
1169  *              prefetch_pages     # pages prefetch iterator is ahead of current
1170  *              prefetch_target    target prefetch distance
1171  * ----------------
1172  */
1173 typedef struct BitmapHeapScanState
1174 {
1175         ScanState       ss;                             /* its first field is NodeTag */
1176         List       *bitmapqualorig;
1177         TIDBitmap  *tbm;
1178         TBMIterator *tbmiterator;
1179         TBMIterateResult *tbmres;
1180         TBMIterator *prefetch_iterator;
1181         int                     prefetch_pages;
1182         int                     prefetch_target;
1183 } BitmapHeapScanState;
1184
1185 /* ----------------
1186  *       TidScanState information
1187  *
1188  *              isCurrentOf    scan has a CurrentOfExpr qual
1189  *              NumTids            number of tids in this scan
1190  *              TidPtr             index of currently fetched tid
1191  *              TidList            evaluated item pointers (array of size NumTids)
1192  * ----------------
1193  */
1194 typedef struct TidScanState
1195 {
1196         ScanState       ss;                             /* its first field is NodeTag */
1197         List       *tss_tidquals;       /* list of ExprState nodes */
1198         bool            tss_isCurrentOf;
1199         int                     tss_NumTids;
1200         int                     tss_TidPtr;
1201         int                     tss_MarkTidPtr;
1202         ItemPointerData *tss_TidList;
1203         HeapTupleData tss_htup;
1204 } TidScanState;
1205
1206 /* ----------------
1207  *       SubqueryScanState information
1208  *
1209  *              SubqueryScanState is used for scanning a sub-query in the range table.
1210  *              ScanTupleSlot references the current output tuple of the sub-query.
1211  * ----------------
1212  */
1213 typedef struct SubqueryScanState
1214 {
1215         ScanState       ss;                             /* its first field is NodeTag */
1216         PlanState  *subplan;
1217 } SubqueryScanState;
1218
1219 /* ----------------
1220  *       FunctionScanState information
1221  *
1222  *              Function nodes are used to scan the results of a
1223  *              function appearing in FROM (typically a function returning set).
1224  *
1225  *              eflags                          node's capability flags
1226  *              tupdesc                         expected return tuple description
1227  *              tuplestorestate         private state of tuplestore.c
1228  *              funcexpr                        state for function expression being evaluated
1229  * ----------------
1230  */
1231 typedef struct FunctionScanState
1232 {
1233         ScanState       ss;                             /* its first field is NodeTag */
1234         int                     eflags;
1235         TupleDesc       tupdesc;
1236         Tuplestorestate *tuplestorestate;
1237         ExprState  *funcexpr;
1238 } FunctionScanState;
1239
1240 /* ----------------
1241  *       ValuesScanState information
1242  *
1243  *              ValuesScan nodes are used to scan the results of a VALUES list
1244  *
1245  *              rowcontext                      per-expression-list context
1246  *              exprlists                       array of expression lists being evaluated
1247  *              array_len                       size of array
1248  *              curr_idx                        current array index (0-based)
1249  *              marked_idx                      marked position (for mark/restore)
1250  *
1251  *      Note: ss.ps.ps_ExprContext is used to evaluate any qual or projection
1252  *      expressions attached to the node.  We create a second ExprContext,
1253  *      rowcontext, in which to build the executor expression state for each
1254  *      Values sublist.  Resetting this context lets us get rid of expression
1255  *      state for each row, avoiding major memory leakage over a long values list.
1256  * ----------------
1257  */
1258 typedef struct ValuesScanState
1259 {
1260         ScanState       ss;                             /* its first field is NodeTag */
1261         ExprContext *rowcontext;
1262         List      **exprlists;
1263         int                     array_len;
1264         int                     curr_idx;
1265         int                     marked_idx;
1266 } ValuesScanState;
1267
1268 /* ----------------
1269  *       CteScanState information
1270  *
1271  *              CteScan nodes are used to scan a CommonTableExpr query.
1272  *
1273  * Multiple CteScan nodes can read out from the same CTE query.  We use
1274  * a tuplestore to hold rows that have been read from the CTE query but
1275  * not yet consumed by all readers.
1276  * ----------------
1277  */
1278 typedef struct CteScanState
1279 {
1280         ScanState       ss;                             /* its first field is NodeTag */
1281         int                     eflags;                 /* capability flags to pass to tuplestore */
1282         int                     readptr;                /* index of my tuplestore read pointer */
1283         PlanState  *cteplanstate;       /* PlanState for the CTE query itself */
1284         /* Link to the "leader" CteScanState (possibly this same node) */
1285         struct CteScanState *leader;
1286         /* The remaining fields are only valid in the "leader" CteScanState */
1287         Tuplestorestate *cte_table; /* rows already read from the CTE query */
1288         bool            eof_cte;                /* reached end of CTE query? */
1289 } CteScanState;
1290
1291 /* ----------------
1292  *       WorkTableScanState information
1293  *
1294  *              WorkTableScan nodes are used to scan the work table created by
1295  *              a RecursiveUnion node.  We locate the RecursiveUnion node
1296  *              during executor startup.
1297  * ----------------
1298  */
1299 typedef struct WorkTableScanState
1300 {
1301         ScanState       ss;                             /* its first field is NodeTag */
1302         RecursiveUnionState *rustate;
1303 } WorkTableScanState;
1304
1305 /* ----------------------------------------------------------------
1306  *                               Join State Information
1307  * ----------------------------------------------------------------
1308  */
1309
1310 /* ----------------
1311  *       JoinState information
1312  *
1313  *              Superclass for state nodes of join plans.
1314  * ----------------
1315  */
1316 typedef struct JoinState
1317 {
1318         PlanState       ps;
1319         JoinType        jointype;
1320         List       *joinqual;           /* JOIN quals (in addition to ps.qual) */
1321 } JoinState;
1322
1323 /* ----------------
1324  *       NestLoopState information
1325  *
1326  *              NeedNewOuter       true if need new outer tuple on next call
1327  *              MatchedOuter       true if found a join match for current outer tuple
1328  *              NullInnerTupleSlot prepared null tuple for left outer joins
1329  * ----------------
1330  */
1331 typedef struct NestLoopState
1332 {
1333         JoinState       js;                             /* its first field is NodeTag */
1334         bool            nl_NeedNewOuter;
1335         bool            nl_MatchedOuter;
1336         TupleTableSlot *nl_NullInnerTupleSlot;
1337 } NestLoopState;
1338
1339 /* ----------------
1340  *       MergeJoinState information
1341  *
1342  *              NumClauses                 number of mergejoinable join clauses
1343  *              Clauses                    info for each mergejoinable clause
1344  *              JoinState                  current "state" of join.  see execdefs.h
1345  *              ExtraMarks                 true to issue extra Mark operations on inner scan
1346  *              FillOuter                  true if should emit unjoined outer tuples anyway
1347  *              FillInner                  true if should emit unjoined inner tuples anyway
1348  *              MatchedOuter       true if found a join match for current outer tuple
1349  *              MatchedInner       true if found a join match for current inner tuple
1350  *              OuterTupleSlot     slot in tuple table for cur outer tuple
1351  *              InnerTupleSlot     slot in tuple table for cur inner tuple
1352  *              MarkedTupleSlot    slot in tuple table for marked tuple
1353  *              NullOuterTupleSlot prepared null tuple for right outer joins
1354  *              NullInnerTupleSlot prepared null tuple for left outer joins
1355  *              OuterEContext      workspace for computing outer tuple's join values
1356  *              InnerEContext      workspace for computing inner tuple's join values
1357  * ----------------
1358  */
1359 /* private in nodeMergejoin.c: */
1360 typedef struct MergeJoinClauseData *MergeJoinClause;
1361
1362 typedef struct MergeJoinState
1363 {
1364         JoinState       js;                             /* its first field is NodeTag */
1365         int                     mj_NumClauses;
1366         MergeJoinClause mj_Clauses; /* array of length mj_NumClauses */
1367         int                     mj_JoinState;
1368         bool            mj_ExtraMarks;
1369         bool            mj_FillOuter;
1370         bool            mj_FillInner;
1371         bool            mj_MatchedOuter;
1372         bool            mj_MatchedInner;
1373         TupleTableSlot *mj_OuterTupleSlot;
1374         TupleTableSlot *mj_InnerTupleSlot;
1375         TupleTableSlot *mj_MarkedTupleSlot;
1376         TupleTableSlot *mj_NullOuterTupleSlot;
1377         TupleTableSlot *mj_NullInnerTupleSlot;
1378         ExprContext *mj_OuterEContext;
1379         ExprContext *mj_InnerEContext;
1380 } MergeJoinState;
1381
1382 /* ----------------
1383  *       HashJoinState information
1384  *
1385  *              hj_HashTable                    hash table for the hashjoin
1386  *                                                              (NULL if table not built yet)
1387  *              hj_CurHashValue                 hash value for current outer tuple
1388  *              hj_CurBucketNo                  regular bucket# for current outer tuple
1389  *              hj_CurSkewBucketNo              skew bucket# for current outer tuple
1390  *              hj_CurTuple                             last inner tuple matched to current outer
1391  *                                                              tuple, or NULL if starting search
1392  *                                                              (hj_CurXXX variables are undefined if
1393  *                                                              OuterTupleSlot is empty!)
1394  *              hj_OuterHashKeys                the outer hash keys in the hashjoin condition
1395  *              hj_InnerHashKeys                the inner hash keys in the hashjoin condition
1396  *              hj_HashOperators                the join operators in the hashjoin condition
1397  *              hj_OuterTupleSlot               tuple slot for outer tuples
1398  *              hj_HashTupleSlot                tuple slot for hashed tuples
1399  *              hj_NullInnerTupleSlot   prepared null tuple for left outer joins
1400  *              hj_FirstOuterTupleSlot  first tuple retrieved from outer plan
1401  *              hj_NeedNewOuter                 true if need new outer tuple on next call
1402  *              hj_MatchedOuter                 true if found a join match for current outer
1403  *              hj_OuterNotEmpty                true if outer relation known not empty
1404  * ----------------
1405  */
1406
1407 /* these structs are defined in executor/hashjoin.h: */
1408 typedef struct HashJoinTupleData *HashJoinTuple;
1409 typedef struct HashJoinTableData *HashJoinTable;
1410
1411 typedef struct HashJoinState
1412 {
1413         JoinState       js;                             /* its first field is NodeTag */
1414         List       *hashclauses;        /* list of ExprState nodes */
1415         HashJoinTable hj_HashTable;
1416         uint32          hj_CurHashValue;
1417         int                     hj_CurBucketNo;
1418         int                     hj_CurSkewBucketNo;
1419         HashJoinTuple hj_CurTuple;
1420         List       *hj_OuterHashKeys;           /* list of ExprState nodes */
1421         List       *hj_InnerHashKeys;           /* list of ExprState nodes */
1422         List       *hj_HashOperators;           /* list of operator OIDs */
1423         TupleTableSlot *hj_OuterTupleSlot;
1424         TupleTableSlot *hj_HashTupleSlot;
1425         TupleTableSlot *hj_NullInnerTupleSlot;
1426         TupleTableSlot *hj_FirstOuterTupleSlot;
1427         bool            hj_NeedNewOuter;
1428         bool            hj_MatchedOuter;
1429         bool            hj_OuterNotEmpty;
1430 } HashJoinState;
1431
1432
1433 /* ----------------------------------------------------------------
1434  *                               Materialization State Information
1435  * ----------------------------------------------------------------
1436  */
1437
1438 /* ----------------
1439  *       MaterialState information
1440  *
1441  *              materialize nodes are used to materialize the results
1442  *              of a subplan into a temporary file.
1443  *
1444  *              ss.ss_ScanTupleSlot refers to output of underlying plan.
1445  * ----------------
1446  */
1447 typedef struct MaterialState
1448 {
1449         ScanState       ss;                             /* its first field is NodeTag */
1450         int                     eflags;                 /* capability flags to pass to tuplestore */
1451         bool            eof_underlying; /* reached end of underlying plan? */
1452         Tuplestorestate *tuplestorestate;
1453 } MaterialState;
1454
1455 /* ----------------
1456  *       SortState information
1457  * ----------------
1458  */
1459 typedef struct SortState
1460 {
1461         ScanState       ss;                             /* its first field is NodeTag */
1462         bool            randomAccess;   /* need random access to sort output? */
1463         bool            bounded;                /* is the result set bounded? */
1464         int64           bound;                  /* if bounded, how many tuples are needed */
1465         bool            sort_Done;              /* sort completed yet? */
1466         bool            bounded_Done;   /* value of bounded we did the sort with */
1467         int64           bound_Done;             /* value of bound we did the sort with */
1468         void       *tuplesortstate; /* private state of tuplesort.c */
1469 } SortState;
1470
1471 /* ---------------------
1472  *      GroupState information
1473  * -------------------------
1474  */
1475 typedef struct GroupState
1476 {
1477         ScanState       ss;                             /* its first field is NodeTag */
1478         FmgrInfo   *eqfunctions;        /* per-field lookup data for equality fns */
1479         bool            grp_done;               /* indicates completion of Group scan */
1480 } GroupState;
1481
1482 /* ---------------------
1483  *      AggState information
1484  *
1485  *      ss.ss_ScanTupleSlot refers to output of underlying plan.
1486  *
1487  *      Note: ss.ps.ps_ExprContext contains ecxt_aggvalues and
1488  *      ecxt_aggnulls arrays, which hold the computed agg values for the current
1489  *      input group during evaluation of an Agg node's output tuple(s).  We
1490  *      create a second ExprContext, tmpcontext, in which to evaluate input
1491  *      expressions and run the aggregate transition functions.
1492  * -------------------------
1493  */
1494 /* these structs are private in nodeAgg.c: */
1495 typedef struct AggStatePerAggData *AggStatePerAgg;
1496 typedef struct AggStatePerGroupData *AggStatePerGroup;
1497
1498 typedef struct AggState
1499 {
1500         ScanState       ss;                             /* its first field is NodeTag */
1501         List       *aggs;                       /* all Aggref nodes in targetlist & quals */
1502         int                     numaggs;                /* length of list (could be zero!) */
1503         FmgrInfo   *eqfunctions;        /* per-grouping-field equality fns */
1504         FmgrInfo   *hashfunctions;      /* per-grouping-field hash fns */
1505         AggStatePerAgg peragg;          /* per-Aggref information */
1506         MemoryContext aggcontext;       /* memory context for long-lived data */
1507         ExprContext *tmpcontext;        /* econtext for input expressions */
1508         bool            agg_done;               /* indicates completion of Agg scan */
1509         /* these fields are used in AGG_PLAIN and AGG_SORTED modes: */
1510         AggStatePerGroup pergroup;      /* per-Aggref-per-group working state */
1511         HeapTuple       grp_firstTuple; /* copy of first tuple of current group */
1512         /* these fields are used in AGG_HASHED mode: */
1513         TupleHashTable hashtable;       /* hash table with one entry per group */
1514         TupleTableSlot *hashslot;       /* slot for loading hash table */
1515         List       *hash_needed;        /* list of columns needed in hash table */
1516         bool            table_filled;   /* hash table filled yet? */
1517         TupleHashIterator hashiter; /* for iterating through hash table */
1518 } AggState;
1519
1520 /* ----------------
1521  *      WindowAggState information
1522  * ----------------
1523  */
1524 /* these structs are private in nodeWindowAgg.c: */
1525 typedef struct WindowStatePerFuncData *WindowStatePerFunc;
1526 typedef struct WindowStatePerAggData *WindowStatePerAgg;
1527
1528 typedef struct WindowAggState
1529 {
1530         ScanState       ss;                             /* its first field is NodeTag */
1531
1532         /* these fields are filled in by ExecInitExpr: */
1533         List       *funcs;                      /* all WindowFunc nodes in targetlist */
1534         int                     numfuncs;               /* total number of window functions */
1535         int                     numaggs;                /* number that are plain aggregates */
1536
1537         WindowStatePerFunc perfunc; /* per-window-function information */
1538         WindowStatePerAgg peragg;       /* per-plain-aggregate information */
1539         FmgrInfo   *partEqfunctions;    /* equality funcs for partition columns */
1540         FmgrInfo   *ordEqfunctions; /* equality funcs for ordering columns */
1541         Tuplestorestate *buffer;        /* stores rows of current partition */
1542         int                     current_ptr;    /* read pointer # for current */
1543         int                     agg_ptr;                /* read pointer # for aggregates */
1544         int64           spooled_rows;   /* total # of rows in buffer */
1545         int64           currentpos;             /* position of current row in partition */
1546         int64           frametailpos;   /* current frame tail position */
1547         int64           aggregatedupto; /* rows before this one are aggregated */
1548
1549         MemoryContext wincontext;       /* context for partition-lifespan data */
1550         ExprContext *tmpcontext;        /* short-term evaluation context */
1551
1552         bool            all_done;               /* true if the scan is finished */
1553         bool            partition_spooled;              /* true if all tuples in current
1554                                                                                  * partition have been spooled into
1555                                                                                  * tuplestore */
1556         bool            more_partitions;/* true if there's more partitions after this
1557                                                                  * one */
1558         bool            frametail_valid;/* true if frametailpos is known up to date
1559                                                                  * for current row */
1560
1561         TupleTableSlot *first_part_slot;        /* first tuple of current or next
1562                                                                                  * partition */
1563
1564         /* temporary slots for tuples fetched back from tuplestore */
1565         TupleTableSlot *agg_row_slot;
1566         TupleTableSlot *temp_slot_1;
1567         TupleTableSlot *temp_slot_2;
1568 } WindowAggState;
1569
1570 /* ----------------
1571  *       UniqueState information
1572  *
1573  *              Unique nodes are used "on top of" sort nodes to discard
1574  *              duplicate tuples returned from the sort phase.  Basically
1575  *              all it does is compare the current tuple from the subplan
1576  *              with the previously fetched tuple (stored in its result slot).
1577  *              If the two are identical in all interesting fields, then
1578  *              we just fetch another tuple from the sort and try again.
1579  * ----------------
1580  */
1581 typedef struct UniqueState
1582 {
1583         PlanState       ps;                             /* its first field is NodeTag */
1584         FmgrInfo   *eqfunctions;        /* per-field lookup data for equality fns */
1585         MemoryContext tempContext;      /* short-term context for comparisons */
1586 } UniqueState;
1587
1588 /* ----------------
1589  *       HashState information
1590  * ----------------
1591  */
1592 typedef struct HashState
1593 {
1594         PlanState       ps;                             /* its first field is NodeTag */
1595         HashJoinTable hashtable;        /* hash table for the hashjoin */
1596         List       *hashkeys;           /* list of ExprState nodes */
1597         /* hashkeys is same as parent's hj_InnerHashKeys */
1598 } HashState;
1599
1600 /* ----------------
1601  *       SetOpState information
1602  *
1603  *              Even in "sorted" mode, SetOp nodes are more complex than a simple
1604  *              Unique, since we have to count how many duplicates to return.  But
1605  *              we also support hashing, so this is really more like a cut-down
1606  *              form of Agg.
1607  * ----------------
1608  */
1609 /* this struct is private in nodeSetOp.c: */
1610 typedef struct SetOpStatePerGroupData *SetOpStatePerGroup;
1611
1612 typedef struct SetOpState
1613 {
1614         PlanState       ps;                             /* its first field is NodeTag */
1615         FmgrInfo   *eqfunctions;        /* per-grouping-field equality fns */
1616         FmgrInfo   *hashfunctions;      /* per-grouping-field hash fns */
1617         bool            setop_done;             /* indicates completion of output scan */
1618         long            numOutput;              /* number of dups left to output */
1619         MemoryContext tempContext;      /* short-term context for comparisons */
1620         /* these fields are used in SETOP_SORTED mode: */
1621         SetOpStatePerGroup pergroup;    /* per-group working state */
1622         HeapTuple       grp_firstTuple; /* copy of first tuple of current group */
1623         /* these fields are used in SETOP_HASHED mode: */
1624         TupleHashTable hashtable;       /* hash table with one entry per group */
1625         MemoryContext tableContext; /* memory context containing hash table */
1626         bool            table_filled;   /* hash table filled yet? */
1627         TupleHashIterator hashiter; /* for iterating through hash table */
1628 } SetOpState;
1629
1630 /* ----------------
1631  *       LimitState information
1632  *
1633  *              Limit nodes are used to enforce LIMIT/OFFSET clauses.
1634  *              They just select the desired subrange of their subplan's output.
1635  *
1636  * offset is the number of initial tuples to skip (0 does nothing).
1637  * count is the number of tuples to return after skipping the offset tuples.
1638  * If no limit count was specified, count is undefined and noCount is true.
1639  * When lstate == LIMIT_INITIAL, offset/count/noCount haven't been set yet.
1640  * ----------------
1641  */
1642 typedef enum
1643 {
1644         LIMIT_INITIAL,                          /* initial state for LIMIT node */
1645         LIMIT_RESCAN,                           /* rescan after recomputing parameters */
1646         LIMIT_EMPTY,                            /* there are no returnable rows */
1647         LIMIT_INWINDOW,                         /* have returned a row in the window */
1648         LIMIT_SUBPLANEOF,                       /* at EOF of subplan (within window) */
1649         LIMIT_WINDOWEND,                        /* stepped off end of window */
1650         LIMIT_WINDOWSTART                       /* stepped off beginning of window */
1651 } LimitStateCond;
1652
1653 typedef struct LimitState
1654 {
1655         PlanState       ps;                             /* its first field is NodeTag */
1656         ExprState  *limitOffset;        /* OFFSET parameter, or NULL if none */
1657         ExprState  *limitCount;         /* COUNT parameter, or NULL if none */
1658         int64           offset;                 /* current OFFSET value */
1659         int64           count;                  /* current COUNT, if any */
1660         bool            noCount;                /* if true, ignore count */
1661         LimitStateCond lstate;          /* state machine status, as above */
1662         int64           position;               /* 1-based index of last tuple returned */
1663         TupleTableSlot *subSlot;        /* tuple last obtained from subplan */
1664 } LimitState;
1665
1666 #endif   /* EXECNODES_H */