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