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) 1996-2009, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.231 2009/10/26 02:26:41 tgl Exp $
  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_RecursiveUnion,
  49         T_BitmapAnd,
  50         T_BitmapOr,
  51         T_Scan,
  52         T_SeqScan,
  53         T_IndexScan,
  54         T_BitmapIndexScan,
  55         T_BitmapHeapScan,
  56         T_TidScan,
  57         T_SubqueryScan,
  58         T_FunctionScan,
  59         T_ValuesScan,
  60         T_CteScan,
  61         T_WorkTableScan,
  62         T_Join,
  63         T_NestLoop,
  64         T_MergeJoin,
  65         T_HashJoin,
  66         T_Material,
  67         T_Sort,
  68         T_Group,
  69         T_Agg,
  70         T_WindowAgg,
  71         T_Unique,
  72         T_Hash,
  73         T_SetOp,
  74         T_LockRows,
  75         T_Limit,
  76         /* these aren't subclasses of Plan: */
  77         T_PlanRowMark,
  78         T_PlanInvalItem,
  79
  80         /*
  81          * TAGS FOR PLAN STATE NODES (execnodes.h)
  82          *
  83          * These should correspond one-to-one with Plan node types.
  84          */
  85         T_PlanState = 200,
  86         T_ResultState,
  87         T_ModifyTableState,
  88         T_AppendState,
  89         T_RecursiveUnionState,
  90         T_BitmapAndState,
  91         T_BitmapOrState,
  92         T_ScanState,
  93         T_SeqScanState,
  94         T_IndexScanState,
  95         T_BitmapIndexScanState,
  96         T_BitmapHeapScanState,
  97         T_TidScanState,
  98         T_SubqueryScanState,
  99         T_FunctionScanState,
 100         T_ValuesScanState,
 101         T_CteScanState,
 102         T_WorkTableScanState,
 103         T_JoinState,
 104         T_NestLoopState,
 105         T_MergeJoinState,
 106         T_HashJoinState,
 107         T_MaterialState,
 108         T_SortState,
 109         T_GroupState,
 110         T_AggState,
 111         T_WindowAggState,
 112         T_UniqueState,
 113         T_HashState,
 114         T_SetOpState,
 115         T_LockRowsState,
 116         T_LimitState,
 117
 118         /*
 119          * TAGS FOR PRIMITIVE NODES (primnodes.h)
 120          */
 121         T_Alias = 300,
 122         T_RangeVar,
 123         T_Expr,
 124         T_Var,
 125         T_Const,
 126         T_Param,
 127         T_Aggref,
 128         T_WindowFunc,
 129         T_ArrayRef,
 130         T_FuncExpr,
 131         T_NamedArgExpr,
 132         T_OpExpr,
 133         T_DistinctExpr,
 134         T_ScalarArrayOpExpr,
 135         T_BoolExpr,
 136         T_SubLink,
 137         T_SubPlan,
 138         T_AlternativeSubPlan,
 139         T_FieldSelect,
 140         T_FieldStore,
 141         T_RelabelType,
 142         T_CoerceViaIO,
 143         T_ArrayCoerceExpr,
 144         T_ConvertRowtypeExpr,
 145         T_CaseExpr,
 146         T_CaseWhen,
 147         T_CaseTestExpr,
 148         T_ArrayExpr,
 149         T_RowExpr,
 150         T_RowCompareExpr,
 151         T_CoalesceExpr,
 152         T_MinMaxExpr,
 153         T_XmlExpr,
 154         T_NullIfExpr,
 155         T_NullTest,
 156         T_BooleanTest,
 157         T_CoerceToDomain,
 158         T_CoerceToDomainValue,
 159         T_SetToDefault,
 160         T_CurrentOfExpr,
 161         T_TargetEntry,
 162         T_RangeTblRef,
 163         T_JoinExpr,
 164         T_FromExpr,
 165         T_IntoClause,
 166
 167         /*
 168          * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 169          *
 170          * These correspond (not always one-for-one) to primitive nodes derived
 171          * from Expr.
 172          */
 173         T_ExprState = 400,
 174         T_GenericExprState,
 175         T_AggrefExprState,
 176         T_WindowFuncExprState,
 177         T_ArrayRefExprState,
 178         T_FuncExprState,
 179         T_ScalarArrayOpExprState,
 180         T_BoolExprState,
 181         T_SubPlanState,
 182         T_AlternativeSubPlanState,
 183         T_FieldSelectState,
 184         T_FieldStoreState,
 185         T_CoerceViaIOState,
 186         T_ArrayCoerceExprState,
 187         T_ConvertRowtypeExprState,
 188         T_CaseExprState,
 189         T_CaseWhenState,
 190         T_ArrayExprState,
 191         T_RowExprState,
 192         T_RowCompareExprState,
 193         T_CoalesceExprState,
 194         T_MinMaxExprState,
 195         T_XmlExprState,
 196         T_NullTestState,
 197         T_CoerceToDomainState,
 198         T_DomainConstraintState,
 199
 200         /*
 201          * TAGS FOR PLANNER NODES (relation.h)
 202          */
 203         T_PlannerInfo = 500,
 204         T_PlannerGlobal,
 205         T_RelOptInfo,
 206         T_IndexOptInfo,
 207         T_Path,
 208         T_IndexPath,
 209         T_BitmapHeapPath,
 210         T_BitmapAndPath,
 211         T_BitmapOrPath,
 212         T_NestPath,
 213         T_MergePath,
 214         T_HashPath,
 215         T_TidPath,
 216         T_AppendPath,
 217         T_ResultPath,
 218         T_MaterialPath,
 219         T_UniquePath,
 220         T_NoOpPath,
 221         T_EquivalenceClass,
 222         T_EquivalenceMember,
 223         T_PathKey,
 224         T_RestrictInfo,
 225         T_InnerIndexscanInfo,
 226         T_PlaceHolderVar,
 227         T_SpecialJoinInfo,
 228         T_AppendRelInfo,
 229         T_PlaceHolderInfo,
 230         T_PlannerParamItem,
 231
 232         /*
 233          * TAGS FOR MEMORY NODES (memnodes.h)
 234          */
 235         T_MemoryContext = 600,
 236         T_AllocSetContext,
 237
 238         /*
 239          * TAGS FOR VALUE NODES (value.h)
 240          */
 241         T_Value = 650,
 242         T_Integer,
 243         T_Float,
 244         T_String,
 245         T_BitString,
 246         T_Null,
 247
 248         /*
 249          * TAGS FOR LIST NODES (pg_list.h)
 250          */
 251         T_List,
 252         T_IntList,
 253         T_OidList,
 254
 255         /*
 256          * TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
 257          */
 258         T_Query = 700,
 259         T_PlannedStmt,
 260         T_InsertStmt,
 261         T_DeleteStmt,
 262         T_UpdateStmt,
 263         T_SelectStmt,
 264         T_AlterTableStmt,
 265         T_AlterTableCmd,
 266         T_AlterDomainStmt,
 267         T_SetOperationStmt,
 268         T_GrantStmt,
 269         T_GrantRoleStmt,
 270         T_AlterDefaultPrivilegesStmt,
 271         T_ClosePortalStmt,
 272         T_ClusterStmt,
 273         T_CopyStmt,
 274         T_CreateStmt,
 275         T_DefineStmt,
 276         T_DropStmt,
 277         T_TruncateStmt,
 278         T_CommentStmt,
 279         T_FetchStmt,
 280         T_IndexStmt,
 281         T_CreateFunctionStmt,
 282         T_AlterFunctionStmt,
 283         T_RemoveFuncStmt,
 284         T_DoStmt,
 285         T_RenameStmt,
 286         T_RuleStmt,
 287         T_NotifyStmt,
 288         T_ListenStmt,
 289         T_UnlistenStmt,
 290         T_TransactionStmt,
 291         T_ViewStmt,
 292         T_LoadStmt,
 293         T_CreateDomainStmt,
 294         T_CreatedbStmt,
 295         T_DropdbStmt,
 296         T_VacuumStmt,
 297         T_ExplainStmt,
 298         T_CreateSeqStmt,
 299         T_AlterSeqStmt,
 300         T_VariableSetStmt,
 301         T_VariableShowStmt,
 302         T_DiscardStmt,
 303         T_CreateTrigStmt,
 304         T_DropPropertyStmt,
 305         T_CreatePLangStmt,
 306         T_DropPLangStmt,
 307         T_CreateRoleStmt,
 308         T_AlterRoleStmt,
 309         T_DropRoleStmt,
 310         T_LockStmt,
 311         T_ConstraintsSetStmt,
 312         T_ReindexStmt,
 313         T_CheckPointStmt,
 314         T_CreateSchemaStmt,
 315         T_AlterDatabaseStmt,
 316         T_AlterDatabaseSetStmt,
 317         T_AlterRoleSetStmt,
 318         T_CreateConversionStmt,
 319         T_CreateCastStmt,
 320         T_DropCastStmt,
 321         T_CreateOpClassStmt,
 322         T_CreateOpFamilyStmt,
 323         T_AlterOpFamilyStmt,
 324         T_RemoveOpClassStmt,
 325         T_RemoveOpFamilyStmt,
 326         T_PrepareStmt,
 327         T_ExecuteStmt,
 328         T_DeallocateStmt,
 329         T_DeclareCursorStmt,
 330         T_CreateTableSpaceStmt,
 331         T_DropTableSpaceStmt,
 332         T_AlterObjectSchemaStmt,
 333         T_AlterOwnerStmt,
 334         T_DropOwnedStmt,
 335         T_ReassignOwnedStmt,
 336         T_CompositeTypeStmt,
 337         T_CreateEnumStmt,
 338         T_AlterTSDictionaryStmt,
 339         T_AlterTSConfigurationStmt,
 340         T_CreateFdwStmt,
 341         T_AlterFdwStmt,
 342         T_DropFdwStmt,
 343         T_CreateForeignServerStmt,
 344         T_AlterForeignServerStmt,
 345         T_DropForeignServerStmt,
 346         T_CreateUserMappingStmt,
 347         T_AlterUserMappingStmt,
 348         T_DropUserMappingStmt,
 349
 350         /*
 351          * TAGS FOR PARSE TREE NODES (parsenodes.h)
 352          */
 353         T_A_Expr = 900,
 354         T_ColumnRef,
 355         T_ParamRef,
 356         T_A_Const,
 357         T_FuncCall,
 358         T_A_Star,
 359         T_A_Indices,
 360         T_A_Indirection,
 361         T_A_ArrayExpr,
 362         T_ResTarget,
 363         T_TypeCast,
 364         T_SortBy,
 365         T_WindowDef,
 366         T_RangeSubselect,
 367         T_RangeFunction,
 368         T_TypeName,
 369         T_ColumnDef,
 370         T_IndexElem,
 371         T_Constraint,
 372         T_DefElem,
 373         T_RangeTblEntry,
 374         T_SortGroupClause,
 375         T_WindowClause,
 376         T_PrivGrantee,
 377         T_FuncWithArgs,
 378         T_AccessPriv,
 379         T_CreateOpClassItem,
 380         T_InhRelation,
 381         T_FunctionParameter,
 382         T_LockingClause,
 383         T_RowMarkClause,
 384         T_XmlSerialize,
 385         T_WithClause,
 386         T_CommonTableExpr,
 387
 388         /*
 389          * TAGS FOR RANDOM OTHER STUFF
 390          *
 391          * These are objects that aren't part of parse/plan/execute node tree
 392          * structures, but we give them NodeTags anyway for identification
 393          * purposes (usually because they are involved in APIs where we want to
 394          * pass multiple object types through the same pointer).
 395          */
 396         T_TriggerData = 950,            /* in commands/trigger.h */
 397         T_ReturnSetInfo,                        /* in nodes/execnodes.h */
 398         T_WindowObjectData,                     /* private in nodeWindowAgg.c */
 399         T_TIDBitmap,                            /* in nodes/tidbitmap.h */
 400         T_InlineCodeBlock                       /* in nodes/parsenodes.h */
 401 } NodeTag;
 402
 403 /*
 404  * The first field of a node of any type is guaranteed to be the NodeTag.
 405  * Hence the type of any node can be gotten by casting it to Node. Declaring
 406  * a variable to be of Node * (instead of void *) can also facilitate
 407  * debugging.
 408  */
 409 typedef struct Node
 410 {
 411         NodeTag         type;
 412 } Node;
 413
 414 #define nodeTag(nodeptr)                (((Node*)(nodeptr))->type)
 415
 416 /*
 417  * newNode -
 418  *        create a new node of the specified size and tag the node with the
 419  *        specified tag.
 420  *
 421  * !WARNING!: Avoid using newNode directly. You should be using the
 422  *        macro makeNode.  eg. to create a Query node, use makeNode(Query)
 423  *
 424  * Note: the size argument should always be a compile-time constant, so the
 425  * apparent risk of multiple evaluation doesn't matter in practice.
 426  */
 427 #ifdef __GNUC__
 428
 429 /* With GCC, we can use a compound statement within an expression */
 430 #define newNode(size, tag) \
 431 ({      Node   *_result; \
 432         AssertMacro((size) >= sizeof(Node));            /* need the tag, at least */ \
 433         _result = (Node *) palloc0fast(size); \
 434         _result->type = (tag); \
 435         _result; \
 436 })
 437 #else
 438
 439 /*
 440  *      There is no way to dereference the palloc'ed pointer to assign the
 441  *      tag, and also return the pointer itself, so we need a holder variable.
 442  *      Fortunately, this macro isn't recursive so we just define
 443  *      a global variable for this purpose.
 444  */
 445 extern PGDLLIMPORT Node *newNodeMacroHolder;
 446
 447 #define newNode(size, tag) \
 448 ( \
 449         AssertMacro((size) >= sizeof(Node)),            /* need the tag, at least */ \
 450         newNodeMacroHolder = (Node *) palloc0fast(size), \
 451         newNodeMacroHolder->type = (tag), \
 452         newNodeMacroHolder \
 453 )
 454 #endif   /* __GNUC__ */
 455
 456
 457 #define makeNode(_type_)                ((_type_ *) newNode(sizeof(_type_),T_##_type_))
 458 #define NodeSetTag(nodeptr,t)   (((Node*)(nodeptr))->type = (t))
 459
 460 #define IsA(nodeptr,_type_)             (nodeTag(nodeptr) == T_##_type_)
 461
 462 /* ----------------------------------------------------------------
 463  *                                        extern declarations follow
 464  * ----------------------------------------------------------------
 465  */
 466
 467 /*
 468  * nodes/{outfuncs.c,print.c}
 469  */
 470 extern char *nodeToString(void *obj);
 471
 472 /*
 473  * nodes/{readfuncs.c,read.c}
 474  */
 475 extern void *stringToNode(char *str);
 476
 477 /*
 478  * nodes/copyfuncs.c
 479  */
 480 extern void *copyObject(void *obj);
 481
 482 /*
 483  * nodes/equalfuncs.c
 484  */
 485 extern bool equal(void *a, void *b);
 486
 487
 488 /*
 489  * Typedefs for identifying qualifier selectivities and plan costs as such.
 490  * These are just plain "double"s, but declaring a variable as Selectivity
 491  * or Cost makes the intent more obvious.
 492  *
 493  * These could have gone into plannodes.h or some such, but many files
 494  * depend on them...
 495  */
 496 typedef double Selectivity;             /* fraction of tuples a qualifier will pass */
 497 typedef double Cost;                    /* execution cost (in page-access units) */
 498
 499
 500 /*
 501  * CmdType -
 502  *        enums for type of operation represented by a Query or PlannedStmt
 503  *
 504  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 505  */
 506 typedef enum CmdType
 507 {
 508         CMD_UNKNOWN,
 509         CMD_SELECT,                                     /* select stmt */
 510         CMD_UPDATE,                                     /* update stmt */
 511         CMD_INSERT,                                     /* insert stmt */
 512         CMD_DELETE,
 513         CMD_UTILITY,                            /* cmds like create, destroy, copy, vacuum,
 514                                                                  * etc. */
 515         CMD_NOTHING                                     /* dummy command for instead nothing rules
 516                                                                  * with qual */
 517 } CmdType;
 518
 519
 520 /*
 521  * JoinType -
 522  *        enums for types of relation joins
 523  *
 524  * JoinType determines the exact semantics of joining two relations using
 525  * a matching qualification.  For example, it tells what to do with a tuple
 526  * that has no match in the other relation.
 527  *
 528  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 529  */
 530 typedef enum JoinType
 531 {
 532         /*
 533          * The canonical kinds of joins according to the SQL JOIN syntax. Only
 534          * these codes can appear in parser output (e.g., JoinExpr nodes).
 535          */
 536         JOIN_INNER,                                     /* matching tuple pairs only */
 537         JOIN_LEFT,                                      /* pairs + unmatched LHS tuples */
 538         JOIN_FULL,                                      /* pairs + unmatched LHS + unmatched RHS */
 539         JOIN_RIGHT,                                     /* pairs + unmatched RHS tuples */
 540
 541         /*
 542          * Semijoins and anti-semijoins (as defined in relational theory) do not
 543          * appear in the SQL JOIN syntax, but there are standard idioms for
 544          * representing them (e.g., using EXISTS).      The planner recognizes these
 545          * cases and converts them to joins.  So the planner and executor must
 546          * support these codes.  NOTE: in JOIN_SEMI output, it is unspecified
 547          * which matching RHS row is joined to.  In JOIN_ANTI output, the row is
 548          * guaranteed to be null-extended.
 549          */
 550         JOIN_SEMI,                                      /* 1 copy of each LHS row that has match(es) */
 551         JOIN_ANTI,                                      /* 1 copy of each LHS row that has no match */
 552
 553         /*
 554          * These codes are used internally in the planner, but are not supported
 555          * by the executor (nor, indeed, by most of the planner).
 556          */
 557         JOIN_UNIQUE_OUTER,                      /* LHS path must be made unique */
 558         JOIN_UNIQUE_INNER                       /* RHS path must be made unique */
 559
 560         /*
 561          * We might need additional join types someday.
 562          */
 563 } JoinType;
 564
 565 /*
 566  * OUTER joins are those for which pushed-down quals must behave differently
 567  * from the join's own quals.  This is in fact everything except INNER and
 568  * SEMI joins.  However, this macro must also exclude the JOIN_UNIQUE symbols
 569  * since those are temporary proxies for what will eventually be an INNER
 570  * join.
 571  *
 572  * Note: semijoins are a hybrid case, but we choose to treat them as not
 573  * being outer joins.  This is okay principally because the SQL syntax makes
 574  * it impossible to have a pushed-down qual that refers to the inner relation
 575  * of a semijoin; so there is no strong need to distinguish join quals from
 576  * pushed-down quals.  This is convenient because for almost all purposes,
 577  * quals attached to a semijoin can be treated the same as innerjoin quals.
 578  */
 579 #define IS_OUTER_JOIN(jointype) \
 580         (((1 << (jointype)) & \
 581           ((1 << JOIN_LEFT) | \
 582            (1 << JOIN_FULL) | \
 583            (1 << JOIN_RIGHT) | \
 584            (1 << JOIN_ANTI))) != 0)
 585
 586 #endif   /* NODES_H */