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) 1996-2008, 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 1.216 2008/12/19 16:25:19 petere 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_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_Unique,
  70         T_Hash,
  71         T_SetOp,
  72         T_Limit,
  73         /* this one isn't a subclass of Plan: */
  74         T_PlanInvalItem,
  75
  76         /*
  77          * TAGS FOR PLAN STATE NODES (execnodes.h)
  78          *
  79          * These should correspond one-to-one with Plan node types.
  80          */
  81         T_PlanState = 200,
  82         T_ResultState,
  83         T_AppendState,
  84         T_RecursiveUnionState,
  85         T_BitmapAndState,
  86         T_BitmapOrState,
  87         T_ScanState,
  88         T_SeqScanState,
  89         T_IndexScanState,
  90         T_BitmapIndexScanState,
  91         T_BitmapHeapScanState,
  92         T_TidScanState,
  93         T_SubqueryScanState,
  94         T_FunctionScanState,
  95         T_ValuesScanState,
  96         T_CteScanState,
  97         T_WorkTableScanState,
  98         T_JoinState,
  99         T_NestLoopState,
 100         T_MergeJoinState,
 101         T_HashJoinState,
 102         T_MaterialState,
 103         T_SortState,
 104         T_GroupState,
 105         T_AggState,
 106         T_UniqueState,
 107         T_HashState,
 108         T_SetOpState,
 109         T_LimitState,
 110
 111         /*
 112          * TAGS FOR PRIMITIVE NODES (primnodes.h)
 113          */
 114         T_Alias = 300,
 115         T_RangeVar,
 116         T_Expr,
 117         T_Var,
 118         T_Const,
 119         T_Param,
 120         T_Aggref,
 121         T_ArrayRef,
 122         T_FuncExpr,
 123         T_OpExpr,
 124         T_DistinctExpr,
 125         T_ScalarArrayOpExpr,
 126         T_BoolExpr,
 127         T_SubLink,
 128         T_SubPlan,
 129         T_AlternativeSubPlan,
 130         T_FieldSelect,
 131         T_FieldStore,
 132         T_RelabelType,
 133         T_CoerceViaIO,
 134         T_ArrayCoerceExpr,
 135         T_ConvertRowtypeExpr,
 136         T_CaseExpr,
 137         T_CaseWhen,
 138         T_CaseTestExpr,
 139         T_ArrayExpr,
 140         T_RowExpr,
 141         T_RowCompareExpr,
 142         T_CoalesceExpr,
 143         T_MinMaxExpr,
 144         T_XmlExpr,
 145         T_NullIfExpr,
 146         T_NullTest,
 147         T_BooleanTest,
 148         T_CoerceToDomain,
 149         T_CoerceToDomainValue,
 150         T_SetToDefault,
 151         T_CurrentOfExpr,
 152         T_TargetEntry,
 153         T_RangeTblRef,
 154         T_JoinExpr,
 155         T_FromExpr,
 156         T_IntoClause,
 157
 158         /*
 159          * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 160          *
 161          * These correspond (not always one-for-one) to primitive nodes derived
 162          * from Expr.
 163          */
 164         T_ExprState = 400,
 165         T_GenericExprState,
 166         T_AggrefExprState,
 167         T_ArrayRefExprState,
 168         T_FuncExprState,
 169         T_ScalarArrayOpExprState,
 170         T_BoolExprState,
 171         T_SubPlanState,
 172         T_AlternativeSubPlanState,
 173         T_FieldSelectState,
 174         T_FieldStoreState,
 175         T_CoerceViaIOState,
 176         T_ArrayCoerceExprState,
 177         T_ConvertRowtypeExprState,
 178         T_CaseExprState,
 179         T_CaseWhenState,
 180         T_ArrayExprState,
 181         T_RowExprState,
 182         T_RowCompareExprState,
 183         T_CoalesceExprState,
 184         T_MinMaxExprState,
 185         T_XmlExprState,
 186         T_NullTestState,
 187         T_CoerceToDomainState,
 188         T_DomainConstraintState,
 189
 190         /*
 191          * TAGS FOR PLANNER NODES (relation.h)
 192          */
 193         T_PlannerInfo = 500,
 194         T_PlannerGlobal,
 195         T_RelOptInfo,
 196         T_IndexOptInfo,
 197         T_Path,
 198         T_IndexPath,
 199         T_BitmapHeapPath,
 200         T_BitmapAndPath,
 201         T_BitmapOrPath,
 202         T_NestPath,
 203         T_MergePath,
 204         T_HashPath,
 205         T_TidPath,
 206         T_AppendPath,
 207         T_ResultPath,
 208         T_MaterialPath,
 209         T_UniquePath,
 210         T_EquivalenceClass,
 211         T_EquivalenceMember,
 212         T_PathKey,
 213         T_RestrictInfo,
 214         T_InnerIndexscanInfo,
 215         T_FlattenedSubLink,
 216         T_PlaceHolderVar,
 217         T_SpecialJoinInfo,
 218         T_AppendRelInfo,
 219         T_PlaceHolderInfo,
 220         T_PlannerParamItem,
 221
 222         /*
 223          * TAGS FOR MEMORY NODES (memnodes.h)
 224          */
 225         T_MemoryContext = 600,
 226         T_AllocSetContext,
 227
 228         /*
 229          * TAGS FOR VALUE NODES (value.h)
 230          */
 231         T_Value = 650,
 232         T_Integer,
 233         T_Float,
 234         T_String,
 235         T_BitString,
 236         T_Null,
 237
 238         /*
 239          * TAGS FOR LIST NODES (pg_list.h)
 240          */
 241         T_List,
 242         T_IntList,
 243         T_OidList,
 244
 245         /*
 246          * TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
 247          */
 248         T_Query = 700,
 249         T_PlannedStmt,
 250         T_InsertStmt,
 251         T_DeleteStmt,
 252         T_UpdateStmt,
 253         T_SelectStmt,
 254         T_AlterTableStmt,
 255         T_AlterTableCmd,
 256         T_AlterDomainStmt,
 257         T_SetOperationStmt,
 258         T_GrantStmt,
 259         T_GrantRoleStmt,
 260         T_ClosePortalStmt,
 261         T_ClusterStmt,
 262         T_CopyStmt,
 263         T_CreateStmt,
 264         T_DefineStmt,
 265         T_DropStmt,
 266         T_TruncateStmt,
 267         T_CommentStmt,
 268         T_FetchStmt,
 269         T_IndexStmt,
 270         T_CreateFunctionStmt,
 271         T_AlterFunctionStmt,
 272         T_RemoveFuncStmt,
 273         T_RenameStmt,
 274         T_RuleStmt,
 275         T_NotifyStmt,
 276         T_ListenStmt,
 277         T_UnlistenStmt,
 278         T_TransactionStmt,
 279         T_ViewStmt,
 280         T_LoadStmt,
 281         T_CreateDomainStmt,
 282         T_CreatedbStmt,
 283         T_DropdbStmt,
 284         T_VacuumStmt,
 285         T_ExplainStmt,
 286         T_CreateSeqStmt,
 287         T_AlterSeqStmt,
 288         T_VariableSetStmt,
 289         T_VariableShowStmt,
 290         T_DiscardStmt,
 291         T_CreateTrigStmt,
 292         T_DropPropertyStmt,
 293         T_CreatePLangStmt,
 294         T_DropPLangStmt,
 295         T_CreateRoleStmt,
 296         T_AlterRoleStmt,
 297         T_DropRoleStmt,
 298         T_LockStmt,
 299         T_ConstraintsSetStmt,
 300         T_ReindexStmt,
 301         T_CheckPointStmt,
 302         T_CreateSchemaStmt,
 303         T_AlterDatabaseStmt,
 304         T_AlterDatabaseSetStmt,
 305         T_AlterRoleSetStmt,
 306         T_CreateConversionStmt,
 307         T_CreateCastStmt,
 308         T_DropCastStmt,
 309         T_CreateOpClassStmt,
 310         T_CreateOpFamilyStmt,
 311         T_AlterOpFamilyStmt,
 312         T_RemoveOpClassStmt,
 313         T_RemoveOpFamilyStmt,
 314         T_PrepareStmt,
 315         T_ExecuteStmt,
 316         T_DeallocateStmt,
 317         T_DeclareCursorStmt,
 318         T_CreateTableSpaceStmt,
 319         T_DropTableSpaceStmt,
 320         T_AlterObjectSchemaStmt,
 321         T_AlterOwnerStmt,
 322         T_DropOwnedStmt,
 323         T_ReassignOwnedStmt,
 324         T_CompositeTypeStmt,
 325         T_CreateEnumStmt,
 326         T_AlterTSDictionaryStmt,
 327         T_AlterTSConfigurationStmt,
 328         T_CreateFdwStmt,
 329         T_AlterFdwStmt,
 330         T_DropFdwStmt,
 331         T_CreateForeignServerStmt,
 332         T_AlterForeignServerStmt,
 333         T_DropForeignServerStmt,
 334         T_CreateUserMappingStmt,
 335         T_AlterUserMappingStmt,
 336         T_DropUserMappingStmt,
 337
 338         /*
 339          * TAGS FOR PARSE TREE NODES (parsenodes.h)
 340          */
 341         T_A_Expr = 900,
 342         T_ColumnRef,
 343         T_ParamRef,
 344         T_A_Const,
 345         T_FuncCall,
 346         T_A_Star,
 347         T_A_Indices,
 348         T_A_Indirection,
 349         T_A_ArrayExpr,
 350         T_ResTarget,
 351         T_TypeCast,
 352         T_SortBy,
 353         T_RangeSubselect,
 354         T_RangeFunction,
 355         T_TypeName,
 356         T_ColumnDef,
 357         T_IndexElem,
 358         T_Constraint,
 359         T_DefElem,
 360         T_OptionDefElem,
 361         T_RangeTblEntry,
 362         T_SortGroupClause,
 363         T_FkConstraint,
 364         T_PrivGrantee,
 365         T_FuncWithArgs,
 366         T_PrivTarget,
 367         T_CreateOpClassItem,
 368         T_InhRelation,
 369         T_FunctionParameter,
 370         T_LockingClause,
 371         T_RowMarkClause,
 372         T_XmlSerialize,
 373         T_WithClause,
 374         T_CommonTableExpr,
 375
 376         /*
 377          * TAGS FOR RANDOM OTHER STUFF
 378          *
 379          * These are objects that aren't part of parse/plan/execute node tree
 380          * structures, but we give them NodeTags anyway for identification
 381          * purposes (usually because they are involved in APIs where we want to
 382          * pass multiple object types through the same pointer).
 383          */
 384         T_TriggerData = 950,            /* in commands/trigger.h */
 385         T_ReturnSetInfo,                        /* in nodes/execnodes.h */
 386         T_TIDBitmap                                     /* in nodes/tidbitmap.h */
 387 } NodeTag;
 388
 389 /*
 390  * The first field of a node of any type is guaranteed to be the NodeTag.
 391  * Hence the type of any node can be gotten by casting it to Node. Declaring
 392  * a variable to be of Node * (instead of void *) can also facilitate
 393  * debugging.
 394  */
 395 typedef struct Node
 396 {
 397         NodeTag         type;
 398 } Node;
 399
 400 #define nodeTag(nodeptr)                (((Node*)(nodeptr))->type)
 401
 402 /*
 403  * newNode -
 404  *        create a new node of the specified size and tag the node with the
 405  *        specified tag.
 406  *
 407  * !WARNING!: Avoid using newNode directly. You should be using the
 408  *        macro makeNode.  eg. to create a Query node, use makeNode(Query)
 409  *
 410  * Note: the size argument should always be a compile-time constant, so the
 411  * apparent risk of multiple evaluation doesn't matter in practice.
 412  */
 413 #ifdef __GNUC__
 414
 415 /* With GCC, we can use a compound statement within an expression */
 416 #define newNode(size, tag) \
 417 ({      Node   *_result; \
 418         AssertMacro((size) >= sizeof(Node));            /* need the tag, at least */ \
 419         _result = (Node *) palloc0fast(size); \
 420         _result->type = (tag); \
 421         _result; \
 422 })
 423
 424 #else
 425
 426 /*
 427  *      There is no way to dereference the palloc'ed pointer to assign the
 428  *      tag, and also return the pointer itself, so we need a holder variable.
 429  *      Fortunately, this macro isn't recursive so we just define
 430  *      a global variable for this purpose.
 431  */
 432 extern PGDLLIMPORT Node *newNodeMacroHolder;
 433
 434 #define newNode(size, tag) \
 435 ( \
 436         AssertMacro((size) >= sizeof(Node)),            /* need the tag, at least */ \
 437         newNodeMacroHolder = (Node *) palloc0fast(size), \
 438         newNodeMacroHolder->type = (tag), \
 439         newNodeMacroHolder \
 440 )
 441
 442 #endif   /* __GNUC__ */
 443
 444
 445 #define makeNode(_type_)                ((_type_ *) newNode(sizeof(_type_),T_##_type_))
 446 #define NodeSetTag(nodeptr,t)   (((Node*)(nodeptr))->type = (t))
 447
 448 #define IsA(nodeptr,_type_)             (nodeTag(nodeptr) == T_##_type_)
 449
 450 /* ----------------------------------------------------------------
 451  *                                        extern declarations follow
 452  * ----------------------------------------------------------------
 453  */
 454
 455 /*
 456  * nodes/{outfuncs.c,print.c}
 457  */
 458 extern char *nodeToString(void *obj);
 459
 460 /*
 461  * nodes/{readfuncs.c,read.c}
 462  */
 463 extern void *stringToNode(char *str);
 464
 465 /*
 466  * nodes/copyfuncs.c
 467  */
 468 extern void *copyObject(void *obj);
 469
 470 /*
 471  * nodes/equalfuncs.c
 472  */
 473 extern bool equal(void *a, void *b);
 474
 475
 476 /*
 477  * Typedefs for identifying qualifier selectivities and plan costs as such.
 478  * These are just plain "double"s, but declaring a variable as Selectivity
 479  * or Cost makes the intent more obvious.
 480  *
 481  * These could have gone into plannodes.h or some such, but many files
 482  * depend on them...
 483  */
 484 typedef double Selectivity;             /* fraction of tuples a qualifier will pass */
 485 typedef double Cost;                    /* execution cost (in page-access units) */
 486
 487
 488 /*
 489  * CmdType -
 490  *        enums for type of operation represented by a Query or PlannedStmt
 491  *
 492  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 493  */
 494 typedef enum CmdType
 495 {
 496         CMD_UNKNOWN,
 497         CMD_SELECT,                                     /* select stmt */
 498         CMD_UPDATE,                                     /* update stmt */
 499         CMD_INSERT,                                     /* insert stmt */
 500         CMD_DELETE,
 501         CMD_UTILITY,                            /* cmds like create, destroy, copy, vacuum,
 502                                                                  * etc. */
 503         CMD_NOTHING                                     /* dummy command for instead nothing rules
 504                                                                  * with qual */
 505 } CmdType;
 506
 507
 508 /*
 509  * JoinType -
 510  *        enums for types of relation joins
 511  *
 512  * JoinType determines the exact semantics of joining two relations using
 513  * a matching qualification.  For example, it tells what to do with a tuple
 514  * that has no match in the other relation.
 515  *
 516  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 517  */
 518 typedef enum JoinType
 519 {
 520         /*
 521          * The canonical kinds of joins according to the SQL JOIN syntax.
 522          * Only these codes can appear in parser output (e.g., JoinExpr nodes).
 523          */
 524         JOIN_INNER,                                     /* matching tuple pairs only */
 525         JOIN_LEFT,                                      /* pairs + unmatched LHS tuples */
 526         JOIN_FULL,                                      /* pairs + unmatched LHS + unmatched RHS */
 527         JOIN_RIGHT,                                     /* pairs + unmatched RHS tuples */
 528
 529         /*
 530          * Semijoins and anti-semijoins (as defined in relational theory) do
 531          * not appear in the SQL JOIN syntax, but there are standard idioms for
 532          * representing them (e.g., using EXISTS).  The planner recognizes these
 533          * cases and converts them to joins.  So the planner and executor must
 534          * support these codes.  NOTE: in JOIN_SEMI output, it is unspecified
 535          * which matching RHS row is joined to.  In JOIN_ANTI output, the row
 536          * is guaranteed to be null-extended.
 537          */
 538         JOIN_SEMI,                                      /* 1 copy of each LHS row that has match(es) */
 539         JOIN_ANTI,                                      /* 1 copy of each LHS row that has no match */
 540
 541         /*
 542          * These codes are used internally in the planner, but are not supported
 543          * by the executor (nor, indeed, by most of the planner).
 544          */
 545         JOIN_UNIQUE_OUTER,                      /* LHS path must be made unique */
 546         JOIN_UNIQUE_INNER                       /* RHS path must be made unique */
 547
 548         /*
 549          * We might need additional join types someday.
 550          */
 551 } JoinType;
 552
 553 /*
 554  * OUTER joins are those for which pushed-down quals must behave differently
 555  * from the join's own quals.  This is in fact everything except INNER and
 556  * SEMI joins.  However, this macro must also exclude the JOIN_UNIQUE symbols
 557  * since those are temporary proxies for what will eventually be an INNER
 558  * join.
 559  *
 560  * Note: semijoins are a hybrid case, but we choose to treat them as not
 561  * being outer joins.  This is okay principally because the SQL syntax makes
 562  * it impossible to have a pushed-down qual that refers to the inner relation
 563  * of a semijoin; so there is no strong need to distinguish join quals from
 564  * pushed-down quals.  This is convenient because for almost all purposes,
 565  * quals attached to a semijoin can be treated the same as innerjoin quals.
 566  */
 567 #define IS_OUTER_JOIN(jointype) \
 568         (((1 << (jointype)) & \
 569           ((1 << JOIN_LEFT) | \
 570            (1 << JOIN_FULL) | \
 571            (1 << JOIN_RIGHT) | \
 572            (1 << JOIN_ANTI))) != 0)
 573
 574 #endif   /* NODES_H */