src/include/nodes/nodes.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * nodes.h
   4  *        Definitions for tagged 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 NODES_H
  15 #define NODES_H
  16
  17 /*
  18  * The first field of every node is NodeTag. Each node created (with makeNode)
  19  * will have one of the following tags as the value of its first field.
  20  *
  21  * Note that the numbers of the node tags are not contiguous. We left holes
  22  * here so that we can add more tags without changing the existing enum's.
  23  * (Since node tag numbers never exist outside backend memory, there's no
  24  * real harm in renumbering, it just costs a full rebuild ...)
  25  */
  26 typedef enum NodeTag
  27 {
  28         T_Invalid = 0,
  29
  30         /*
  31          * TAGS FOR EXECUTOR NODES (execnodes.h)
  32          */
  33         T_IndexInfo = 10,
  34         T_ExprContext,
  35         T_ProjectionInfo,
  36         T_JunkFilter,
  37         T_ResultRelInfo,
  38         T_EState,
  39         T_TupleTableSlot,
  40
  41         /*
  42          * TAGS FOR PLAN NODES (plannodes.h)
  43          */
  44         T_Plan = 100,
  45         T_Result,
  46         T_Append,
  47         T_RecursiveUnion,
  48         T_BitmapAnd,
  49         T_BitmapOr,
  50         T_Scan,
  51         T_SeqScan,
  52         T_IndexScan,
  53         T_BitmapIndexScan,
  54         T_BitmapHeapScan,
  55         T_TidScan,
  56         T_SubqueryScan,
  57         T_FunctionScan,
  58         T_ValuesScan,
  59         T_CteScan,
  60         T_WorkTableScan,
  61         T_Join,
  62         T_NestLoop,
  63         T_MergeJoin,
  64         T_HashJoin,
  65         T_Material,
  66         T_Sort,
  67         T_Group,
  68         T_Agg,
  69         T_WindowAgg,
  70         T_Unique,
  71         T_Hash,
  72         T_SetOp,
  73         T_Limit,
  74         /* this one isn't a subclass of Plan: */
  75         T_PlanInvalItem,
  76
  77         /*
  78          * TAGS FOR PLAN STATE NODES (execnodes.h)
  79          *
  80          * These should correspond one-to-one with Plan node types.
  81          */
  82         T_PlanState = 200,
  83         T_ResultState,
  84         T_AppendState,
  85         T_RecursiveUnionState,
  86         T_BitmapAndState,
  87         T_BitmapOrState,
  88         T_ScanState,
  89         T_SeqScanState,
  90         T_IndexScanState,
  91         T_BitmapIndexScanState,
  92         T_BitmapHeapScanState,
  93         T_TidScanState,
  94         T_SubqueryScanState,
  95         T_FunctionScanState,
  96         T_ValuesScanState,
  97         T_CteScanState,
  98         T_WorkTableScanState,
  99         T_JoinState,
 100         T_NestLoopState,
 101         T_MergeJoinState,
 102         T_HashJoinState,
 103         T_MaterialState,
 104         T_SortState,
 105         T_GroupState,
 106         T_AggState,
 107         T_WindowAggState,
 108         T_UniqueState,
 109         T_HashState,
 110         T_SetOpState,
 111         T_LimitState,
 112
 113         /*
 114          * TAGS FOR PRIMITIVE NODES (primnodes.h)
 115          */
 116         T_Alias = 300,
 117         T_RangeVar,
 118         T_Expr,
 119         T_Var,
 120         T_Const,
 121         T_Param,
 122         T_Aggref,
 123         T_WindowFunc,
 124         T_ArrayRef,
 125         T_FuncExpr,
 126         T_OpExpr,
 127         T_DistinctExpr,
 128         T_ScalarArrayOpExpr,
 129         T_BoolExpr,
 130         T_SubLink,
 131         T_SubPlan,
 132         T_AlternativeSubPlan,
 133         T_FieldSelect,
 134         T_FieldStore,
 135         T_RelabelType,
 136         T_CoerceViaIO,
 137         T_ArrayCoerceExpr,
 138         T_ConvertRowtypeExpr,
 139         T_CaseExpr,
 140         T_CaseWhen,
 141         T_CaseTestExpr,
 142         T_ArrayExpr,
 143         T_RowExpr,
 144         T_RowCompareExpr,
 145         T_CoalesceExpr,
 146         T_MinMaxExpr,
 147         T_XmlExpr,
 148         T_NullIfExpr,
 149         T_NullTest,
 150         T_BooleanTest,
 151         T_CoerceToDomain,
 152         T_CoerceToDomainValue,
 153         T_SetToDefault,
 154         T_CurrentOfExpr,
 155         T_TargetEntry,
 156         T_RangeTblRef,
 157         T_JoinExpr,
 158         T_FromExpr,
 159         T_IntoClause,
 160
 161         /*
 162          * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 163          *
 164          * These correspond (not always one-for-one) to primitive nodes derived
 165          * from Expr.
 166          */
 167         T_ExprState = 400,
 168         T_GenericExprState,
 169         T_AggrefExprState,
 170         T_WindowFuncExprState,
 171         T_ArrayRefExprState,
 172         T_FuncExprState,
 173         T_ScalarArrayOpExprState,
 174         T_BoolExprState,
 175         T_SubPlanState,
 176         T_AlternativeSubPlanState,
 177         T_FieldSelectState,
 178         T_FieldStoreState,
 179         T_CoerceViaIOState,
 180         T_ArrayCoerceExprState,
 181         T_ConvertRowtypeExprState,
 182         T_CaseExprState,
 183         T_CaseWhenState,
 184         T_ArrayExprState,
 185         T_RowExprState,
 186         T_RowCompareExprState,
 187         T_CoalesceExprState,
 188         T_MinMaxExprState,
 189         T_XmlExprState,
 190         T_NullTestState,
 191         T_CoerceToDomainState,
 192         T_DomainConstraintState,
 193
 194         /*
 195          * TAGS FOR PLANNER NODES (relation.h)
 196          */
 197         T_PlannerInfo = 500,
 198         T_PlannerGlobal,
 199         T_RelOptInfo,
 200         T_IndexOptInfo,
 201         T_Path,
 202         T_IndexPath,
 203         T_BitmapHeapPath,
 204         T_BitmapAndPath,
 205         T_BitmapOrPath,
 206         T_NestPath,
 207         T_MergePath,
 208         T_HashPath,
 209         T_TidPath,
 210         T_AppendPath,
 211         T_ResultPath,
 212         T_MaterialPath,
 213         T_UniquePath,
 214         T_EquivalenceClass,
 215         T_EquivalenceMember,
 216         T_PathKey,
 217         T_RestrictInfo,
 218         T_InnerIndexscanInfo,
 219         T_PlaceHolderVar,
 220         T_SpecialJoinInfo,
 221         T_AppendRelInfo,
 222         T_PlaceHolderInfo,
 223         T_PlannerParamItem,
 224
 225         /*
 226          * TAGS FOR MEMORY NODES (memnodes.h)
 227          */
 228         T_MemoryContext = 600,
 229         T_AllocSetContext,
 230
 231         /*
 232          * TAGS FOR VALUE NODES (value.h)
 233          */
 234         T_Value = 650,
 235         T_Integer,
 236         T_Float,
 237         T_String,
 238         T_BitString,
 239         T_Null,
 240
 241         /*
 242          * TAGS FOR LIST NODES (pg_list.h)
 243          */
 244         T_List,
 245         T_IntList,
 246         T_OidList,
 247
 248         /*
 249          * TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
 250          */
 251         T_Query = 700,
 252         T_PlannedStmt,
 253         T_InsertStmt,
 254         T_DeleteStmt,
 255         T_UpdateStmt,
 256         T_SelectStmt,
 257         T_AlterTableStmt,
 258         T_AlterTableCmd,
 259         T_AlterDomainStmt,
 260         T_SetOperationStmt,
 261         T_GrantStmt,
 262         T_GrantRoleStmt,
 263         T_ClosePortalStmt,
 264         T_ClusterStmt,
 265         T_CopyStmt,
 266         T_CreateStmt,
 267         T_DefineStmt,
 268         T_DropStmt,
 269         T_TruncateStmt,
 270         T_CommentStmt,
 271         T_FetchStmt,
 272         T_IndexStmt,
 273         T_CreateFunctionStmt,
 274         T_AlterFunctionStmt,
 275         T_RemoveFuncStmt,
 276         T_RenameStmt,
 277         T_RuleStmt,
 278         T_NotifyStmt,
 279         T_ListenStmt,
 280         T_UnlistenStmt,
 281         T_TransactionStmt,
 282         T_ViewStmt,
 283         T_LoadStmt,
 284         T_CreateDomainStmt,
 285         T_CreatedbStmt,
 286         T_DropdbStmt,
 287         T_VacuumStmt,
 288         T_ExplainStmt,
 289         T_CreateSeqStmt,
 290         T_AlterSeqStmt,
 291         T_VariableSetStmt,
 292         T_VariableShowStmt,
 293         T_DiscardStmt,
 294         T_CreateTrigStmt,
 295         T_DropPropertyStmt,
 296         T_CreatePLangStmt,
 297         T_DropPLangStmt,
 298         T_CreateRoleStmt,
 299         T_AlterRoleStmt,
 300         T_DropRoleStmt,
 301         T_LockStmt,
 302         T_ConstraintsSetStmt,
 303         T_ReindexStmt,
 304         T_CheckPointStmt,
 305         T_CreateSchemaStmt,
 306         T_AlterDatabaseStmt,
 307         T_AlterDatabaseSetStmt,
 308         T_AlterRoleSetStmt,
 309         T_CreateConversionStmt,
 310         T_CreateCastStmt,
 311         T_DropCastStmt,
 312         T_CreateOpClassStmt,
 313         T_CreateOpFamilyStmt,
 314         T_AlterOpFamilyStmt,
 315         T_RemoveOpClassStmt,
 316         T_RemoveOpFamilyStmt,
 317         T_PrepareStmt,
 318         T_ExecuteStmt,
 319         T_DeallocateStmt,
 320         T_DeclareCursorStmt,
 321         T_CreateTableSpaceStmt,
 322         T_DropTableSpaceStmt,
 323         T_AlterObjectSchemaStmt,
 324         T_AlterOwnerStmt,
 325         T_DropOwnedStmt,
 326         T_ReassignOwnedStmt,
 327         T_CompositeTypeStmt,
 328         T_CreateEnumStmt,
 329         T_AlterTSDictionaryStmt,
 330         T_AlterTSConfigurationStmt,
 331         T_CreateFdwStmt,
 332         T_AlterFdwStmt,
 333         T_DropFdwStmt,
 334         T_CreateForeignServerStmt,
 335         T_AlterForeignServerStmt,
 336         T_DropForeignServerStmt,
 337         T_CreateUserMappingStmt,
 338         T_AlterUserMappingStmt,
 339         T_DropUserMappingStmt,
 340
 341         /*
 342          * TAGS FOR PARSE TREE NODES (parsenodes.h)
 343          */
 344         T_A_Expr = 900,
 345         T_ColumnRef,
 346         T_ParamRef,
 347         T_A_Const,
 348         T_FuncCall,
 349         T_A_Star,
 350         T_A_Indices,
 351         T_A_Indirection,
 352         T_A_ArrayExpr,
 353         T_ResTarget,
 354         T_TypeCast,
 355         T_SortBy,
 356         T_WindowDef,
 357         T_RangeSubselect,
 358         T_RangeFunction,
 359         T_TypeName,
 360         T_ColumnDef,
 361         T_IndexElem,
 362         T_Constraint,
 363         T_DefElem,
 364         T_RangeTblEntry,
 365         T_SortGroupClause,
 366         T_WindowClause,
 367         T_FkConstraint,
 368         T_PrivGrantee,
 369         T_FuncWithArgs,
 370         T_AccessPriv,
 371         T_CreateOpClassItem,
 372         T_InhRelation,
 373         T_FunctionParameter,
 374         T_LockingClause,
 375         T_RowMarkClause,
 376         T_XmlSerialize,
 377         T_WithClause,
 378         T_CommonTableExpr,
 379
 380         /*
 381          * TAGS FOR RANDOM OTHER STUFF
 382          *
 383          * These are objects that aren't part of parse/plan/execute node tree
 384          * structures, but we give them NodeTags anyway for identification
 385          * purposes (usually because they are involved in APIs where we want to
 386          * pass multiple object types through the same pointer).
 387          */
 388         T_TriggerData = 950,            /* in commands/trigger.h */
 389         T_ReturnSetInfo,                        /* in nodes/execnodes.h */
 390         T_WindowObjectData,                     /* private in nodeWindowAgg.c */
 391         T_TIDBitmap                                     /* in nodes/tidbitmap.h */
 392 } NodeTag;
 393
 394 /*
 395  * The first field of a node of any type is guaranteed to be the NodeTag.
 396  * Hence the type of any node can be gotten by casting it to Node. Declaring
 397  * a variable to be of Node * (instead of void *) can also facilitate
 398  * debugging.
 399  */
 400 typedef struct Node
 401 {
 402         NodeTag         type;
 403 } Node;
 404
 405 #define nodeTag(nodeptr)                (((Node*)(nodeptr))->type)
 406
 407 /*
 408  * newNode -
 409  *        create a new node of the specified size and tag the node with the
 410  *        specified tag.
 411  *
 412  * !WARNING!: Avoid using newNode directly. You should be using the
 413  *        macro makeNode.  eg. to create a Query node, use makeNode(Query)
 414  *
 415  * Note: the size argument should always be a compile-time constant, so the
 416  * apparent risk of multiple evaluation doesn't matter in practice.
 417  */
 418 #ifdef __GNUC__
 419
 420 /* With GCC, we can use a compound statement within an expression */
 421 #define newNode(size, tag) \
 422 ({      Node   *_result; \
 423         AssertMacro((size) >= sizeof(Node));            /* need the tag, at least */ \
 424         _result = (Node *) palloc0fast(size); \
 425         _result->type = (tag); \
 426         _result; \
 427 })
 428 #else
 429
 430 /*
 431  *      There is no way to dereference the palloc'ed pointer to assign the
 432  *      tag, and also return the pointer itself, so we need a holder variable.
 433  *      Fortunately, this macro isn't recursive so we just define
 434  *      a global variable for this purpose.
 435  */
 436 extern PGDLLIMPORT Node *newNodeMacroHolder;
 437
 438 #define newNode(size, tag) \
 439 ( \
 440         AssertMacro((size) >= sizeof(Node)),            /* need the tag, at least */ \
 441         newNodeMacroHolder = (Node *) palloc0fast(size), \
 442         newNodeMacroHolder->type = (tag), \
 443         newNodeMacroHolder \
 444 )
 445 #endif   /* __GNUC__ */
 446
 447
 448 #define makeNode(_type_)                ((_type_ *) newNode(sizeof(_type_),T_##_type_))
 449 #define NodeSetTag(nodeptr,t)   (((Node*)(nodeptr))->type = (t))
 450
 451 #define IsA(nodeptr,_type_)             (nodeTag(nodeptr) == T_##_type_)
 452
 453 /* ----------------------------------------------------------------
 454  *                                        extern declarations follow
 455  * ----------------------------------------------------------------
 456  */
 457
 458 /*
 459  * nodes/{outfuncs.c,print.c}
 460  */
 461 extern char *nodeToString(void *obj);
 462
 463 /*
 464  * nodes/{readfuncs.c,read.c}
 465  */
 466 extern void *stringToNode(char *str);
 467
 468 /*
 469  * nodes/copyfuncs.c
 470  */
 471 extern void *copyObject(void *obj);
 472
 473 /*
 474  * nodes/equalfuncs.c
 475  */
 476 extern bool equal(void *a, void *b);
 477
 478
 479 /*
 480  * Typedefs for identifying qualifier selectivities and plan costs as such.
 481  * These are just plain "double"s, but declaring a variable as Selectivity
 482  * or Cost makes the intent more obvious.
 483  *
 484  * These could have gone into plannodes.h or some such, but many files
 485  * depend on them...
 486  */
 487 typedef double Selectivity;             /* fraction of tuples a qualifier will pass */
 488 typedef double Cost;                    /* execution cost (in page-access units) */
 489
 490
 491 /*
 492  * CmdType -
 493  *        enums for type of operation represented by a Query or PlannedStmt
 494  *
 495  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 496  */
 497 typedef enum CmdType
 498 {
 499         CMD_UNKNOWN,
 500         CMD_SELECT,                                     /* select stmt */
 501         CMD_UPDATE,                                     /* update stmt */
 502         CMD_INSERT,                                     /* insert stmt */
 503         CMD_DELETE,
 504         CMD_UTILITY,                            /* cmds like create, destroy, copy, vacuum,
 505                                                                  * etc. */
 506         CMD_NOTHING                                     /* dummy command for instead nothing rules
 507                                                                  * with qual */
 508 } CmdType;
 509
 510
 511 /*
 512  * JoinType -
 513  *        enums for types of relation joins
 514  *
 515  * JoinType determines the exact semantics of joining two relations using
 516  * a matching qualification.  For example, it tells what to do with a tuple
 517  * that has no match in the other relation.
 518  *
 519  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 520  */
 521 typedef enum JoinType
 522 {
 523         /*
 524          * The canonical kinds of joins according to the SQL JOIN syntax. Only
 525          * these codes can appear in parser output (e.g., JoinExpr nodes).
 526          */
 527         JOIN_INNER,                                     /* matching tuple pairs only */
 528         JOIN_LEFT,                                      /* pairs + unmatched LHS tuples */
 529         JOIN_FULL,                                      /* pairs + unmatched LHS + unmatched RHS */
 530         JOIN_RIGHT,                                     /* pairs + unmatched RHS tuples */
 531
 532         /*
 533          * Semijoins and anti-semijoins (as defined in relational theory) do not
 534          * appear in the SQL JOIN syntax, but there are standard idioms for
 535          * representing them (e.g., using EXISTS).      The planner recognizes these
 536          * cases and converts them to joins.  So the planner and executor must
 537          * support these codes.  NOTE: in JOIN_SEMI output, it is unspecified
 538          * which matching RHS row is joined to.  In JOIN_ANTI output, the row is
 539          * guaranteed to be null-extended.
 540          */
 541         JOIN_SEMI,                                      /* 1 copy of each LHS row that has match(es) */
 542         JOIN_ANTI,                                      /* 1 copy of each LHS row that has no match */
 543
 544         /*
 545          * These codes are used internally in the planner, but are not supported
 546          * by the executor (nor, indeed, by most of the planner).
 547          */
 548         JOIN_UNIQUE_OUTER,                      /* LHS path must be made unique */
 549         JOIN_UNIQUE_INNER                       /* RHS path must be made unique */
 550
 551         /*
 552          * We might need additional join types someday.
 553          */
 554 } JoinType;
 555
 556 /*
 557  * OUTER joins are those for which pushed-down quals must behave differently
 558  * from the join's own quals.  This is in fact everything except INNER and
 559  * SEMI joins.  However, this macro must also exclude the JOIN_UNIQUE symbols
 560  * since those are temporary proxies for what will eventually be an INNER
 561  * join.
 562  *
 563  * Note: semijoins are a hybrid case, but we choose to treat them as not
 564  * being outer joins.  This is okay principally because the SQL syntax makes
 565  * it impossible to have a pushed-down qual that refers to the inner relation
 566  * of a semijoin; so there is no strong need to distinguish join quals from
 567  * pushed-down quals.  This is convenient because for almost all purposes,
 568  * quals attached to a semijoin can be treated the same as innerjoin quals.
 569  */
 570 #define IS_OUTER_JOIN(jointype) \
 571         (((1 << (jointype)) & \
 572           ((1 << JOIN_LEFT) | \
 573            (1 << JOIN_FULL) | \
 574            (1 << JOIN_RIGHT) | \
 575            (1 << JOIN_ANTI))) != 0)
 576
 577 #endif   /* NODES_H */