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