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) 1996-2012, 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_Join,
  66         T_NestLoop,
  67         T_MergeJoin,
  68         T_HashJoin,
  69         T_Material,
  70         T_Sort,
  71         T_Group,
  72         T_Agg,
  73         T_WindowAgg,
  74         T_Unique,
  75         T_Hash,
  76         T_SetOp,
  77         T_LockRows,
  78         T_Limit,
  79         /* these aren't subclasses of Plan: */
  80         T_NestLoopParam,
  81         T_PlanRowMark,
  82         T_PlanInvalItem,
  83
  84         /*
  85          * TAGS FOR PLAN STATE NODES (execnodes.h)
  86          *
  87          * These should correspond one-to-one with Plan node types.
  88          */
  89         T_PlanState = 200,
  90         T_ResultState,
  91         T_ModifyTableState,
  92         T_AppendState,
  93         T_MergeAppendState,
  94         T_RecursiveUnionState,
  95         T_BitmapAndState,
  96         T_BitmapOrState,
  97         T_ScanState,
  98         T_SeqScanState,
  99         T_IndexScanState,
 100         T_IndexOnlyScanState,
 101         T_BitmapIndexScanState,
 102         T_BitmapHeapScanState,
 103         T_TidScanState,
 104         T_SubqueryScanState,
 105         T_FunctionScanState,
 106         T_ValuesScanState,
 107         T_CteScanState,
 108         T_WorkTableScanState,
 109         T_ForeignScanState,
 110         T_JoinState,
 111         T_NestLoopState,
 112         T_MergeJoinState,
 113         T_HashJoinState,
 114         T_MaterialState,
 115         T_SortState,
 116         T_GroupState,
 117         T_AggState,
 118         T_WindowAggState,
 119         T_UniqueState,
 120         T_HashState,
 121         T_SetOpState,
 122         T_LockRowsState,
 123         T_LimitState,
 124
 125         /*
 126          * TAGS FOR PRIMITIVE NODES (primnodes.h)
 127          */
 128         T_Alias = 300,
 129         T_RangeVar,
 130         T_Expr,
 131         T_Var,
 132         T_Const,
 133         T_Param,
 134         T_Aggref,
 135         T_WindowFunc,
 136         T_ArrayRef,
 137         T_FuncExpr,
 138         T_NamedArgExpr,
 139         T_OpExpr,
 140         T_DistinctExpr,
 141         T_NullIfExpr,
 142         T_ScalarArrayOpExpr,
 143         T_BoolExpr,
 144         T_SubLink,
 145         T_SubPlan,
 146         T_AlternativeSubPlan,
 147         T_FieldSelect,
 148         T_FieldStore,
 149         T_RelabelType,
 150         T_CoerceViaIO,
 151         T_ArrayCoerceExpr,
 152         T_ConvertRowtypeExpr,
 153         T_CollateExpr,
 154         T_CaseExpr,
 155         T_CaseWhen,
 156         T_CaseTestExpr,
 157         T_ArrayExpr,
 158         T_RowExpr,
 159         T_RowCompareExpr,
 160         T_CoalesceExpr,
 161         T_MinMaxExpr,
 162         T_XmlExpr,
 163         T_NullTest,
 164         T_BooleanTest,
 165         T_CoerceToDomain,
 166         T_CoerceToDomainValue,
 167         T_SetToDefault,
 168         T_CurrentOfExpr,
 169         T_TargetEntry,
 170         T_RangeTblRef,
 171         T_JoinExpr,
 172         T_FromExpr,
 173         T_IntoClause,
 174
 175         /*
 176          * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 177          *
 178          * These correspond (not always one-for-one) to primitive nodes derived
 179          * from Expr.
 180          */
 181         T_ExprState = 400,
 182         T_GenericExprState,
 183         T_WholeRowVarExprState,
 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_ParamPathInfo,
 217         T_Path,
 218         T_IndexPath,
 219         T_BitmapHeapPath,
 220         T_BitmapAndPath,
 221         T_BitmapOrPath,
 222         T_NestPath,
 223         T_MergePath,
 224         T_HashPath,
 225         T_TidPath,
 226         T_ForeignPath,
 227         T_AppendPath,
 228         T_MergeAppendPath,
 229         T_ResultPath,
 230         T_MaterialPath,
 231         T_UniquePath,
 232         T_EquivalenceClass,
 233         T_EquivalenceMember,
 234         T_PathKey,
 235         T_RestrictInfo,
 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_CreateTableAsStmt,
 309         T_CreateSeqStmt,
 310         T_AlterSeqStmt,
 311         T_VariableSetStmt,
 312         T_VariableShowStmt,
 313         T_DiscardStmt,
 314         T_CreateTrigStmt,
 315         T_CreatePLangStmt,
 316         T_CreateRoleStmt,
 317         T_AlterRoleStmt,
 318         T_DropRoleStmt,
 319         T_LockStmt,
 320         T_ConstraintsSetStmt,
 321         T_ReindexStmt,
 322         T_CheckPointStmt,
 323         T_CreateSchemaStmt,
 324         T_AlterDatabaseStmt,
 325         T_AlterDatabaseSetStmt,
 326         T_AlterRoleSetStmt,
 327         T_CreateConversionStmt,
 328         T_CreateCastStmt,
 329         T_CreateOpClassStmt,
 330         T_CreateOpFamilyStmt,
 331         T_AlterOpFamilyStmt,
 332         T_PrepareStmt,
 333         T_ExecuteStmt,
 334         T_DeallocateStmt,
 335         T_DeclareCursorStmt,
 336         T_CreateTableSpaceStmt,
 337         T_DropTableSpaceStmt,
 338         T_AlterObjectSchemaStmt,
 339         T_AlterOwnerStmt,
 340         T_DropOwnedStmt,
 341         T_ReassignOwnedStmt,
 342         T_CompositeTypeStmt,
 343         T_CreateEnumStmt,
 344         T_CreateRangeStmt,
 345         T_AlterEnumStmt,
 346         T_AlterTSDictionaryStmt,
 347         T_AlterTSConfigurationStmt,
 348         T_CreateFdwStmt,
 349         T_AlterFdwStmt,
 350         T_CreateForeignServerStmt,
 351         T_AlterForeignServerStmt,
 352         T_CreateUserMappingStmt,
 353         T_AlterUserMappingStmt,
 354         T_DropUserMappingStmt,
 355         T_AlterTableSpaceOptionsStmt,
 356         T_SecLabelStmt,
 357         T_CreateForeignTableStmt,
 358         T_CreateExtensionStmt,
 359         T_AlterExtensionStmt,
 360         T_AlterExtensionContentsStmt,
 361         T_CreateEventTrigStmt,
 362         T_AlterEventTrigStmt,
 363
 364         /*
 365          * TAGS FOR PARSE TREE NODES (parsenodes.h)
 366          */
 367         T_A_Expr = 900,
 368         T_ColumnRef,
 369         T_ParamRef,
 370         T_A_Const,
 371         T_FuncCall,
 372         T_A_Star,
 373         T_A_Indices,
 374         T_A_Indirection,
 375         T_A_ArrayExpr,
 376         T_ResTarget,
 377         T_TypeCast,
 378         T_CollateClause,
 379         T_SortBy,
 380         T_WindowDef,
 381         T_RangeSubselect,
 382         T_RangeFunction,
 383         T_TypeName,
 384         T_ColumnDef,
 385         T_IndexElem,
 386         T_Constraint,
 387         T_DefElem,
 388         T_RangeTblEntry,
 389         T_SortGroupClause,
 390         T_WindowClause,
 391         T_PrivGrantee,
 392         T_FuncWithArgs,
 393         T_AccessPriv,
 394         T_CreateOpClassItem,
 395         T_TableLikeClause,
 396         T_FunctionParameter,
 397         T_LockingClause,
 398         T_RowMarkClause,
 399         T_XmlSerialize,
 400         T_WithClause,
 401         T_CommonTableExpr,
 402
 403         /*
 404          * TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
 405          */
 406         T_IdentifySystemCmd,
 407         T_BaseBackupCmd,
 408         T_StartReplicationCmd,
 409
 410         /*
 411          * TAGS FOR RANDOM OTHER STUFF
 412          *
 413          * These are objects that aren't part of parse/plan/execute node tree
 414          * structures, but we give them NodeTags anyway for identification
 415          * purposes (usually because they are involved in APIs where we want to
 416          * pass multiple object types through the same pointer).
 417          */
 418         T_TriggerData = 950,            /* in commands/trigger.h */
 419         T_EventTriggerData,                     /* in commands/event_trigger.h */
 420         T_ReturnSetInfo,                        /* in nodes/execnodes.h */
 421         T_WindowObjectData,                     /* private in nodeWindowAgg.c */
 422         T_TIDBitmap,                            /* in nodes/tidbitmap.h */
 423         T_InlineCodeBlock,                      /* in nodes/parsenodes.h */
 424         T_FdwRoutine                            /* in foreign/fdwapi.h */
 425 } NodeTag;
 426
 427 /*
 428  * The first field of a node of any type is guaranteed to be the NodeTag.
 429  * Hence the type of any node can be gotten by casting it to Node. Declaring
 430  * a variable to be of Node * (instead of void *) can also facilitate
 431  * debugging.
 432  */
 433 typedef struct Node
 434 {
 435         NodeTag         type;
 436 } Node;
 437
 438 #define nodeTag(nodeptr)                (((const Node*)(nodeptr))->type)
 439
 440 /*
 441  * newNode -
 442  *        create a new node of the specified size and tag the node with the
 443  *        specified tag.
 444  *
 445  * !WARNING!: Avoid using newNode directly. You should be using the
 446  *        macro makeNode.  eg. to create a Query node, use makeNode(Query)
 447  *
 448  * Note: the size argument should always be a compile-time constant, so the
 449  * apparent risk of multiple evaluation doesn't matter in practice.
 450  */
 451 #ifdef __GNUC__
 452
 453 /* With GCC, we can use a compound statement within an expression */
 454 #define newNode(size, tag) \
 455 ({      Node   *_result; \
 456         AssertMacro((size) >= sizeof(Node));            /* need the tag, at least */ \
 457         _result = (Node *) palloc0fast(size); \
 458         _result->type = (tag); \
 459         _result; \
 460 })
 461 #else
 462
 463 /*
 464  *      There is no way to dereference the palloc'ed pointer to assign the
 465  *      tag, and also return the pointer itself, so we need a holder variable.
 466  *      Fortunately, this macro isn't recursive so we just define
 467  *      a global variable for this purpose.
 468  */
 469 extern PGDLLIMPORT Node *newNodeMacroHolder;
 470
 471 #define newNode(size, tag) \
 472 ( \
 473         AssertMacro((size) >= sizeof(Node)),            /* need the tag, at least */ \
 474         newNodeMacroHolder = (Node *) palloc0fast(size), \
 475         newNodeMacroHolder->type = (tag), \
 476         newNodeMacroHolder \
 477 )
 478 #endif   /* __GNUC__ */
 479
 480
 481 #define makeNode(_type_)                ((_type_ *) newNode(sizeof(_type_),T_##_type_))
 482 #define NodeSetTag(nodeptr,t)   (((Node*)(nodeptr))->type = (t))
 483
 484 #define IsA(nodeptr,_type_)             (nodeTag(nodeptr) == T_##_type_)
 485
 486 /* ----------------------------------------------------------------
 487  *                                        extern declarations follow
 488  * ----------------------------------------------------------------
 489  */
 490
 491 /*
 492  * nodes/{outfuncs.c,print.c}
 493  */
 494 extern char *nodeToString(const void *obj);
 495
 496 /*
 497  * nodes/{readfuncs.c,read.c}
 498  */
 499 extern void *stringToNode(char *str);
 500
 501 /*
 502  * nodes/copyfuncs.c
 503  */
 504 extern void *copyObject(const void *obj);
 505
 506 /*
 507  * nodes/equalfuncs.c
 508  */
 509 extern bool equal(const void *a, const void *b);
 510
 511
 512 /*
 513  * Typedefs for identifying qualifier selectivities and plan costs as such.
 514  * These are just plain "double"s, but declaring a variable as Selectivity
 515  * or Cost makes the intent more obvious.
 516  *
 517  * These could have gone into plannodes.h or some such, but many files
 518  * depend on them...
 519  */
 520 typedef double Selectivity;             /* fraction of tuples a qualifier will pass */
 521 typedef double Cost;                    /* execution cost (in page-access units) */
 522
 523
 524 /*
 525  * CmdType -
 526  *        enums for type of operation represented by a Query or PlannedStmt
 527  *
 528  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 529  */
 530 typedef enum CmdType
 531 {
 532         CMD_UNKNOWN,
 533         CMD_SELECT,                                     /* select stmt */
 534         CMD_UPDATE,                                     /* update stmt */
 535         CMD_INSERT,                                     /* insert stmt */
 536         CMD_DELETE,
 537         CMD_UTILITY,                            /* cmds like create, destroy, copy, vacuum,
 538                                                                  * etc. */
 539         CMD_NOTHING                                     /* dummy command for instead nothing rules
 540                                                                  * with qual */
 541 } CmdType;
 542
 543
 544 /*
 545  * JoinType -
 546  *        enums for types of relation joins
 547  *
 548  * JoinType determines the exact semantics of joining two relations using
 549  * a matching qualification.  For example, it tells what to do with a tuple
 550  * that has no match in the other relation.
 551  *
 552  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 553  */
 554 typedef enum JoinType
 555 {
 556         /*
 557          * The canonical kinds of joins according to the SQL JOIN syntax. Only
 558          * these codes can appear in parser output (e.g., JoinExpr nodes).
 559          */
 560         JOIN_INNER,                                     /* matching tuple pairs only */
 561         JOIN_LEFT,                                      /* pairs + unmatched LHS tuples */
 562         JOIN_FULL,                                      /* pairs + unmatched LHS + unmatched RHS */
 563         JOIN_RIGHT,                                     /* pairs + unmatched RHS tuples */
 564
 565         /*
 566          * Semijoins and anti-semijoins (as defined in relational theory) do not
 567          * appear in the SQL JOIN syntax, but there are standard idioms for
 568          * representing them (e.g., using EXISTS).      The planner recognizes these
 569          * cases and converts them to joins.  So the planner and executor must
 570          * support these codes.  NOTE: in JOIN_SEMI output, it is unspecified
 571          * which matching RHS row is joined to.  In JOIN_ANTI output, the row is
 572          * guaranteed to be null-extended.
 573          */
 574         JOIN_SEMI,                                      /* 1 copy of each LHS row that has match(es) */
 575         JOIN_ANTI,                                      /* 1 copy of each LHS row that has no match */
 576
 577         /*
 578          * These codes are used internally in the planner, but are not supported
 579          * by the executor (nor, indeed, by most of the planner).
 580          */
 581         JOIN_UNIQUE_OUTER,                      /* LHS path must be made unique */
 582         JOIN_UNIQUE_INNER                       /* RHS path must be made unique */
 583
 584         /*
 585          * We might need additional join types someday.
 586          */
 587 } JoinType;
 588
 589 /*
 590  * OUTER joins are those for which pushed-down quals must behave differently
 591  * from the join's own quals.  This is in fact everything except INNER and
 592  * SEMI joins.  However, this macro must also exclude the JOIN_UNIQUE symbols
 593  * since those are temporary proxies for what will eventually be an INNER
 594  * join.
 595  *
 596  * Note: semijoins are a hybrid case, but we choose to treat them as not
 597  * being outer joins.  This is okay principally because the SQL syntax makes
 598  * it impossible to have a pushed-down qual that refers to the inner relation
 599  * of a semijoin; so there is no strong need to distinguish join quals from
 600  * pushed-down quals.  This is convenient because for almost all purposes,
 601  * quals attached to a semijoin can be treated the same as innerjoin quals.
 602  */
 603 #define IS_OUTER_JOIN(jointype) \
 604         (((1 << (jointype)) & \
 605           ((1 << JOIN_LEFT) | \
 606            (1 << JOIN_FULL) | \
 607            (1 << JOIN_RIGHT) | \
 608            (1 << JOIN_ANTI))) != 0)
 609
 610 #endif   /* NODES_H */