granicus.if.org Git - postgresql/blob - src/include/nodes/nodes.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * nodes.h
   4  *        Definitions for tagged nodes.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * src/include/nodes/nodes.h
  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_ModifyTable,
  47         T_Append,
  48         T_MergeAppend,
  49         T_RecursiveUnion,
  50         T_BitmapAnd,
  51         T_BitmapOr,
  52         T_Scan,
  53         T_SeqScan,
  54         T_IndexScan,
  55         T_IndexOnlyScan,
  56         T_BitmapIndexScan,
  57         T_BitmapHeapScan,
  58         T_TidScan,
  59         T_SubqueryScan,
  60         T_FunctionScan,
  61         T_ValuesScan,
  62         T_CteScan,
  63         T_WorkTableScan,
  64         T_ForeignScan,
  65         T_FdwPlan,
  66         T_Join,
  67         T_NestLoop,
  68         T_MergeJoin,
  69         T_HashJoin,
  70         T_Material,
  71         T_Sort,
  72         T_Group,
  73         T_Agg,
  74         T_WindowAgg,
  75         T_Unique,
  76         T_Hash,
  77         T_SetOp,
  78         T_LockRows,
  79         T_Limit,
  80         /* these aren't subclasses of Plan: */
  81         T_NestLoopParam,
  82         T_PlanRowMark,
  83         T_PlanInvalItem,
  84
  85         /*
  86          * TAGS FOR PLAN STATE NODES (execnodes.h)
  87          *
  88          * These should correspond one-to-one with Plan node types.
  89          */
  90         T_PlanState = 200,
  91         T_ResultState,
  92         T_ModifyTableState,
  93         T_AppendState,
  94         T_MergeAppendState,
  95         T_RecursiveUnionState,
  96         T_BitmapAndState,
  97         T_BitmapOrState,
  98         T_ScanState,
  99         T_SeqScanState,
 100         T_IndexScanState,
 101         T_IndexOnlyScanState,
 102         T_BitmapIndexScanState,
 103         T_BitmapHeapScanState,
 104         T_TidScanState,
 105         T_SubqueryScanState,
 106         T_FunctionScanState,
 107         T_ValuesScanState,
 108         T_CteScanState,
 109         T_WorkTableScanState,
 110         T_ForeignScanState,
 111         T_JoinState,
 112         T_NestLoopState,
 113         T_MergeJoinState,
 114         T_HashJoinState,
 115         T_MaterialState,
 116         T_SortState,
 117         T_GroupState,
 118         T_AggState,
 119         T_WindowAggState,
 120         T_UniqueState,
 121         T_HashState,
 122         T_SetOpState,
 123         T_LockRowsState,
 124         T_LimitState,
 125
 126         /*
 127          * TAGS FOR PRIMITIVE NODES (primnodes.h)
 128          */
 129         T_Alias = 300,
 130         T_RangeVar,
 131         T_Expr,
 132         T_Var,
 133         T_Const,
 134         T_Param,
 135         T_Aggref,
 136         T_WindowFunc,
 137         T_ArrayRef,
 138         T_FuncExpr,
 139         T_NamedArgExpr,
 140         T_OpExpr,
 141         T_DistinctExpr,
 142         T_NullIfExpr,
 143         T_ScalarArrayOpExpr,
 144         T_BoolExpr,
 145         T_SubLink,
 146         T_SubPlan,
 147         T_AlternativeSubPlan,
 148         T_FieldSelect,
 149         T_FieldStore,
 150         T_RelabelType,
 151         T_CoerceViaIO,
 152         T_ArrayCoerceExpr,
 153         T_ConvertRowtypeExpr,
 154         T_CollateExpr,
 155         T_CaseExpr,
 156         T_CaseWhen,
 157         T_CaseTestExpr,
 158         T_ArrayExpr,
 159         T_RowExpr,
 160         T_RowCompareExpr,
 161         T_CoalesceExpr,
 162         T_MinMaxExpr,
 163         T_XmlExpr,
 164         T_NullTest,
 165         T_BooleanTest,
 166         T_CoerceToDomain,
 167         T_CoerceToDomainValue,
 168         T_SetToDefault,
 169         T_CurrentOfExpr,
 170         T_TargetEntry,
 171         T_RangeTblRef,
 172         T_JoinExpr,
 173         T_FromExpr,
 174         T_IntoClause,
 175
 176         /*
 177          * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 178          *
 179          * These correspond (not always one-for-one) to primitive nodes derived
 180          * from Expr.
 181          */
 182         T_ExprState = 400,
 183         T_GenericExprState,
 184         T_AggrefExprState,
 185         T_WindowFuncExprState,
 186         T_ArrayRefExprState,
 187         T_FuncExprState,
 188         T_ScalarArrayOpExprState,
 189         T_BoolExprState,
 190         T_SubPlanState,
 191         T_AlternativeSubPlanState,
 192         T_FieldSelectState,
 193         T_FieldStoreState,
 194         T_CoerceViaIOState,
 195         T_ArrayCoerceExprState,
 196         T_ConvertRowtypeExprState,
 197         T_CaseExprState,
 198         T_CaseWhenState,
 199         T_ArrayExprState,
 200         T_RowExprState,
 201         T_RowCompareExprState,
 202         T_CoalesceExprState,
 203         T_MinMaxExprState,
 204         T_XmlExprState,
 205         T_NullTestState,
 206         T_CoerceToDomainState,
 207         T_DomainConstraintState,
 208
 209         /*
 210          * TAGS FOR PLANNER NODES (relation.h)
 211          */
 212         T_PlannerInfo = 500,
 213         T_PlannerGlobal,
 214         T_RelOptInfo,
 215         T_IndexOptInfo,
 216         T_Path,
 217         T_IndexPath,
 218         T_BitmapHeapPath,
 219         T_BitmapAndPath,
 220         T_BitmapOrPath,
 221         T_NestPath,
 222         T_MergePath,
 223         T_HashPath,
 224         T_TidPath,
 225         T_ForeignPath,
 226         T_AppendPath,
 227         T_MergeAppendPath,
 228         T_ResultPath,
 229         T_MaterialPath,
 230         T_UniquePath,
 231         T_EquivalenceClass,
 232         T_EquivalenceMember,
 233         T_PathKey,
 234         T_RestrictInfo,
 235         T_InnerIndexscanInfo,
 236         T_PlaceHolderVar,
 237         T_SpecialJoinInfo,
 238         T_AppendRelInfo,
 239         T_PlaceHolderInfo,
 240         T_MinMaxAggInfo,
 241         T_PlannerParamItem,
 242
 243         /*
 244          * TAGS FOR MEMORY NODES (memnodes.h)
 245          */
 246         T_MemoryContext = 600,
 247         T_AllocSetContext,
 248
 249         /*
 250          * TAGS FOR VALUE NODES (value.h)
 251          */
 252         T_Value = 650,
 253         T_Integer,
 254         T_Float,
 255         T_String,
 256         T_BitString,
 257         T_Null,
 258
 259         /*
 260          * TAGS FOR LIST NODES (pg_list.h)
 261          */
 262         T_List,
 263         T_IntList,
 264         T_OidList,
 265
 266         /*
 267          * TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
 268          */
 269         T_Query = 700,
 270         T_PlannedStmt,
 271         T_InsertStmt,
 272         T_DeleteStmt,
 273         T_UpdateStmt,
 274         T_SelectStmt,
 275         T_AlterTableStmt,
 276         T_AlterTableCmd,
 277         T_AlterDomainStmt,
 278         T_SetOperationStmt,
 279         T_GrantStmt,
 280         T_GrantRoleStmt,
 281         T_AlterDefaultPrivilegesStmt,
 282         T_ClosePortalStmt,
 283         T_ClusterStmt,
 284         T_CopyStmt,
 285         T_CreateStmt,
 286         T_DefineStmt,
 287         T_DropStmt,
 288         T_TruncateStmt,
 289         T_CommentStmt,
 290         T_FetchStmt,
 291         T_IndexStmt,
 292         T_CreateFunctionStmt,
 293         T_AlterFunctionStmt,
 294         T_DoStmt,
 295         T_RenameStmt,
 296         T_RuleStmt,
 297         T_NotifyStmt,
 298         T_ListenStmt,
 299         T_UnlistenStmt,
 300         T_TransactionStmt,
 301         T_ViewStmt,
 302         T_LoadStmt,
 303         T_CreateDomainStmt,
 304         T_CreatedbStmt,
 305         T_DropdbStmt,
 306         T_VacuumStmt,
 307         T_ExplainStmt,
 308         T_CreateSeqStmt,
 309         T_AlterSeqStmt,
 310         T_VariableSetStmt,
 311         T_VariableShowStmt,
 312         T_DiscardStmt,
 313         T_CreateTrigStmt,
 314         T_CreatePLangStmt,
 315         T_CreateRoleStmt,
 316         T_AlterRoleStmt,
 317         T_DropRoleStmt,
 318         T_LockStmt,
 319         T_ConstraintsSetStmt,
 320         T_ReindexStmt,
 321         T_CheckPointStmt,
 322         T_CreateSchemaStmt,
 323         T_AlterDatabaseStmt,
 324         T_AlterDatabaseSetStmt,
 325         T_AlterRoleSetStmt,
 326         T_CreateConversionStmt,
 327         T_CreateCastStmt,
 328         T_CreateOpClassStmt,
 329         T_CreateOpFamilyStmt,
 330         T_AlterOpFamilyStmt,
 331         T_PrepareStmt,
 332         T_ExecuteStmt,
 333         T_DeallocateStmt,
 334         T_DeclareCursorStmt,
 335         T_CreateTableSpaceStmt,
 336         T_DropTableSpaceStmt,
 337         T_AlterObjectSchemaStmt,
 338         T_AlterOwnerStmt,
 339         T_DropOwnedStmt,
 340         T_ReassignOwnedStmt,
 341         T_CompositeTypeStmt,
 342         T_CreateEnumStmt,
 343         T_CreateRangeStmt,
 344         T_AlterEnumStmt,
 345         T_AlterTSDictionaryStmt,
 346         T_AlterTSConfigurationStmt,
 347         T_CreateFdwStmt,
 348         T_AlterFdwStmt,
 349         T_CreateForeignServerStmt,
 350         T_AlterForeignServerStmt,
 351         T_CreateUserMappingStmt,
 352         T_AlterUserMappingStmt,
 353         T_DropUserMappingStmt,
 354         T_AlterTableSpaceOptionsStmt,
 355         T_SecLabelStmt,
 356         T_CreateForeignTableStmt,
 357         T_CreateExtensionStmt,
 358         T_AlterExtensionStmt,
 359         T_AlterExtensionContentsStmt,
 360
 361         /*
 362          * TAGS FOR PARSE TREE NODES (parsenodes.h)
 363          */
 364         T_A_Expr = 900,
 365         T_ColumnRef,
 366         T_ParamRef,
 367         T_A_Const,
 368         T_FuncCall,
 369         T_A_Star,
 370         T_A_Indices,
 371         T_A_Indirection,
 372         T_A_ArrayExpr,
 373         T_ResTarget,
 374         T_TypeCast,
 375         T_CollateClause,
 376         T_SortBy,
 377         T_WindowDef,
 378         T_RangeSubselect,
 379         T_RangeFunction,
 380         T_TypeName,
 381         T_ColumnDef,
 382         T_IndexElem,
 383         T_Constraint,
 384         T_DefElem,
 385         T_RangeTblEntry,
 386         T_SortGroupClause,
 387         T_WindowClause,
 388         T_PrivGrantee,
 389         T_FuncWithArgs,
 390         T_AccessPriv,
 391         T_CreateOpClassItem,
 392         T_InhRelation,
 393         T_FunctionParameter,
 394         T_LockingClause,
 395         T_RowMarkClause,
 396         T_XmlSerialize,
 397         T_WithClause,
 398         T_CommonTableExpr,
 399
 400         /*
 401          * TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
 402          */
 403         T_IdentifySystemCmd,
 404         T_BaseBackupCmd,
 405         T_StartReplicationCmd,
 406
 407         /*
 408          * TAGS FOR RANDOM OTHER STUFF
 409          *
 410          * These are objects that aren't part of parse/plan/execute node tree
 411          * structures, but we give them NodeTags anyway for identification
 412          * purposes (usually because they are involved in APIs where we want to
 413          * pass multiple object types through the same pointer).
 414          */
 415         T_TriggerData = 950,            /* in commands/trigger.h */
 416         T_ReturnSetInfo,                        /* in nodes/execnodes.h */
 417         T_WindowObjectData,                     /* private in nodeWindowAgg.c */
 418         T_TIDBitmap,                            /* in nodes/tidbitmap.h */
 419         T_InlineCodeBlock,                      /* in nodes/parsenodes.h */
 420         T_FdwRoutine                            /* in foreign/fdwapi.h */
 421 } NodeTag;
 422
 423 /*
 424  * The first field of a node of any type is guaranteed to be the NodeTag.
 425  * Hence the type of any node can be gotten by casting it to Node. Declaring
 426  * a variable to be of Node * (instead of void *) can also facilitate
 427  * debugging.
 428  */
 429 typedef struct Node
 430 {
 431         NodeTag         type;
 432 } Node;
 433
 434 #define nodeTag(nodeptr)                (((Node*)(nodeptr))->type)
 435
 436 /*
 437  * newNode -
 438  *        create a new node of the specified size and tag the node with the
 439  *        specified tag.
 440  *
 441  * !WARNING!: Avoid using newNode directly. You should be using the
 442  *        macro makeNode.  eg. to create a Query node, use makeNode(Query)
 443  *
 444  * Note: the size argument should always be a compile-time constant, so the
 445  * apparent risk of multiple evaluation doesn't matter in practice.
 446  */
 447 #ifdef __GNUC__
 448
 449 /* With GCC, we can use a compound statement within an expression */
 450 #define newNode(size, tag) \
 451 ({      Node   *_result; \
 452         AssertMacro((size) >= sizeof(Node));            /* need the tag, at least */ \
 453         _result = (Node *) palloc0fast(size); \
 454         _result->type = (tag); \
 455         _result; \
 456 })
 457 #else
 458
 459 /*
 460  *      There is no way to dereference the palloc'ed pointer to assign the
 461  *      tag, and also return the pointer itself, so we need a holder variable.
 462  *      Fortunately, this macro isn't recursive so we just define
 463  *      a global variable for this purpose.
 464  */
 465 extern PGDLLIMPORT Node *newNodeMacroHolder;
 466
 467 #define newNode(size, tag) \
 468 ( \
 469         AssertMacro((size) >= sizeof(Node)),            /* need the tag, at least */ \
 470         newNodeMacroHolder = (Node *) palloc0fast(size), \
 471         newNodeMacroHolder->type = (tag), \
 472         newNodeMacroHolder \
 473 )
 474 #endif   /* __GNUC__ */
 475
 476
 477 #define makeNode(_type_)                ((_type_ *) newNode(sizeof(_type_),T_##_type_))
 478 #define NodeSetTag(nodeptr,t)   (((Node*)(nodeptr))->type = (t))
 479
 480 #define IsA(nodeptr,_type_)             (nodeTag(nodeptr) == T_##_type_)
 481
 482 /* ----------------------------------------------------------------
 483  *                                        extern declarations follow
 484  * ----------------------------------------------------------------
 485  */
 486
 487 /*
 488  * nodes/{outfuncs.c,print.c}
 489  */
 490 extern char *nodeToString(void *obj);
 491
 492 /*
 493  * nodes/{readfuncs.c,read.c}
 494  */
 495 extern void *stringToNode(char *str);
 496
 497 /*
 498  * nodes/copyfuncs.c
 499  */
 500 extern void *copyObject(void *obj);
 501
 502 /*
 503  * nodes/equalfuncs.c
 504  */
 505 extern bool equal(void *a, void *b);
 506
 507
 508 /*
 509  * Typedefs for identifying qualifier selectivities and plan costs as such.
 510  * These are just plain "double"s, but declaring a variable as Selectivity
 511  * or Cost makes the intent more obvious.
 512  *
 513  * These could have gone into plannodes.h or some such, but many files
 514  * depend on them...
 515  */
 516 typedef double Selectivity;             /* fraction of tuples a qualifier will pass */
 517 typedef double Cost;                    /* execution cost (in page-access units) */
 518
 519
 520 /*
 521  * CmdType -
 522  *        enums for type of operation represented by a Query or PlannedStmt
 523  *
 524  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 525  */
 526 typedef enum CmdType
 527 {
 528         CMD_UNKNOWN,
 529         CMD_SELECT,                                     /* select stmt */
 530         CMD_UPDATE,                                     /* update stmt */
 531         CMD_INSERT,                                     /* insert stmt */
 532         CMD_DELETE,
 533         CMD_UTILITY,                            /* cmds like create, destroy, copy, vacuum,
 534                                                                  * etc. */
 535         CMD_NOTHING                                     /* dummy command for instead nothing rules
 536                                                                  * with qual */
 537 } CmdType;
 538
 539
 540 /*
 541  * JoinType -
 542  *        enums for types of relation joins
 543  *
 544  * JoinType determines the exact semantics of joining two relations using
 545  * a matching qualification.  For example, it tells what to do with a tuple
 546  * that has no match in the other relation.
 547  *
 548  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 549  */
 550 typedef enum JoinType
 551 {
 552         /*
 553          * The canonical kinds of joins according to the SQL JOIN syntax. Only
 554          * these codes can appear in parser output (e.g., JoinExpr nodes).
 555          */
 556         JOIN_INNER,                                     /* matching tuple pairs only */
 557         JOIN_LEFT,                                      /* pairs + unmatched LHS tuples */
 558         JOIN_FULL,                                      /* pairs + unmatched LHS + unmatched RHS */
 559         JOIN_RIGHT,                                     /* pairs + unmatched RHS tuples */
 560
 561         /*
 562          * Semijoins and anti-semijoins (as defined in relational theory) do not
 563          * appear in the SQL JOIN syntax, but there are standard idioms for
 564          * representing them (e.g., using EXISTS).      The planner recognizes these
 565          * cases and converts them to joins.  So the planner and executor must
 566          * support these codes.  NOTE: in JOIN_SEMI output, it is unspecified
 567          * which matching RHS row is joined to.  In JOIN_ANTI output, the row is
 568          * guaranteed to be null-extended.
 569          */
 570         JOIN_SEMI,                                      /* 1 copy of each LHS row that has match(es) */
 571         JOIN_ANTI,                                      /* 1 copy of each LHS row that has no match */
 572
 573         /*
 574          * These codes are used internally in the planner, but are not supported
 575          * by the executor (nor, indeed, by most of the planner).
 576          */
 577         JOIN_UNIQUE_OUTER,                      /* LHS path must be made unique */
 578         JOIN_UNIQUE_INNER                       /* RHS path must be made unique */
 579
 580         /*
 581          * We might need additional join types someday.
 582          */
 583 } JoinType;
 584
 585 /*
 586  * OUTER joins are those for which pushed-down quals must behave differently
 587  * from the join's own quals.  This is in fact everything except INNER and
 588  * SEMI joins.  However, this macro must also exclude the JOIN_UNIQUE symbols
 589  * since those are temporary proxies for what will eventually be an INNER
 590  * join.
 591  *
 592  * Note: semijoins are a hybrid case, but we choose to treat them as not
 593  * being outer joins.  This is okay principally because the SQL syntax makes
 594  * it impossible to have a pushed-down qual that refers to the inner relation
 595  * of a semijoin; so there is no strong need to distinguish join quals from
 596  * pushed-down quals.  This is convenient because for almost all purposes,
 597  * quals attached to a semijoin can be treated the same as innerjoin quals.
 598  */
 599 #define IS_OUTER_JOIN(jointype) \
 600         (((1 << (jointype)) & \
 601           ((1 << JOIN_LEFT) | \
 602            (1 << JOIN_FULL) | \
 603            (1 << JOIN_RIGHT) | \
 604            (1 << JOIN_ANTI))) != 0)
 605
 606 #endif   /* NODES_H */