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 1.208 2008/08/14 18:48:00 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_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
  71         /*
  72          * TAGS FOR PLAN STATE NODES (execnodes.h)
  73          *
  74          * These should correspond one-to-one with Plan node types.
  75          */
  76         T_PlanState = 200,
  77         T_ResultState,
  78         T_AppendState,
  79         T_BitmapAndState,
  80         T_BitmapOrState,
  81         T_ScanState,
  82         T_SeqScanState,
  83         T_IndexScanState,
  84         T_BitmapIndexScanState,
  85         T_BitmapHeapScanState,
  86         T_TidScanState,
  87         T_SubqueryScanState,
  88         T_FunctionScanState,
  89         T_ValuesScanState,
  90         T_JoinState,
  91         T_NestLoopState,
  92         T_MergeJoinState,
  93         T_HashJoinState,
  94         T_MaterialState,
  95         T_SortState,
  96         T_GroupState,
  97         T_AggState,
  98         T_UniqueState,
  99         T_HashState,
 100         T_SetOpState,
 101         T_LimitState,
 102
 103         /*
 104          * TAGS FOR PRIMITIVE NODES (primnodes.h)
 105          */
 106         T_Alias = 300,
 107         T_RangeVar,
 108         T_Expr,
 109         T_Var,
 110         T_Const,
 111         T_Param,
 112         T_Aggref,
 113         T_ArrayRef,
 114         T_FuncExpr,
 115         T_OpExpr,
 116         T_DistinctExpr,
 117         T_ScalarArrayOpExpr,
 118         T_BoolExpr,
 119         T_SubLink,
 120         T_SubPlan,
 121         T_FieldSelect,
 122         T_FieldStore,
 123         T_RelabelType,
 124         T_CoerceViaIO,
 125         T_ArrayCoerceExpr,
 126         T_ConvertRowtypeExpr,
 127         T_CaseExpr,
 128         T_CaseWhen,
 129         T_CaseTestExpr,
 130         T_ArrayExpr,
 131         T_RowExpr,
 132         T_RowCompareExpr,
 133         T_CoalesceExpr,
 134         T_MinMaxExpr,
 135         T_XmlExpr,
 136         T_NullIfExpr,
 137         T_NullTest,
 138         T_BooleanTest,
 139         T_CoerceToDomain,
 140         T_CoerceToDomainValue,
 141         T_SetToDefault,
 142         T_CurrentOfExpr,
 143         T_TargetEntry,
 144         T_RangeTblRef,
 145         T_JoinExpr,
 146         T_FromExpr,
 147         T_IntoClause,
 148
 149         /*
 150          * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 151          *
 152          * These correspond (not always one-for-one) to primitive nodes derived
 153          * from Expr.
 154          */
 155         T_ExprState = 400,
 156         T_GenericExprState,
 157         T_AggrefExprState,
 158         T_ArrayRefExprState,
 159         T_FuncExprState,
 160         T_ScalarArrayOpExprState,
 161         T_BoolExprState,
 162         T_SubPlanState,
 163         T_FieldSelectState,
 164         T_FieldStoreState,
 165         T_CoerceViaIOState,
 166         T_ArrayCoerceExprState,
 167         T_ConvertRowtypeExprState,
 168         T_CaseExprState,
 169         T_CaseWhenState,
 170         T_ArrayExprState,
 171         T_RowExprState,
 172         T_RowCompareExprState,
 173         T_CoalesceExprState,
 174         T_MinMaxExprState,
 175         T_XmlExprState,
 176         T_NullTestState,
 177         T_CoerceToDomainState,
 178         T_DomainConstraintState,
 179
 180         /*
 181          * TAGS FOR PLANNER NODES (relation.h)
 182          */
 183         T_PlannerInfo = 500,
 184         T_PlannerGlobal,
 185         T_RelOptInfo,
 186         T_IndexOptInfo,
 187         T_Path,
 188         T_IndexPath,
 189         T_BitmapHeapPath,
 190         T_BitmapAndPath,
 191         T_BitmapOrPath,
 192         T_NestPath,
 193         T_MergePath,
 194         T_HashPath,
 195         T_TidPath,
 196         T_AppendPath,
 197         T_ResultPath,
 198         T_MaterialPath,
 199         T_UniquePath,
 200         T_EquivalenceClass,
 201         T_EquivalenceMember,
 202         T_PathKey,
 203         T_RestrictInfo,
 204         T_InnerIndexscanInfo,
 205         T_FlattenedSubLink,
 206         T_SpecialJoinInfo,
 207         T_AppendRelInfo,
 208         T_PlannerParamItem,
 209
 210         /*
 211          * TAGS FOR MEMORY NODES (memnodes.h)
 212          */
 213         T_MemoryContext = 600,
 214         T_AllocSetContext,
 215
 216         /*
 217          * TAGS FOR VALUE NODES (value.h)
 218          */
 219         T_Value = 650,
 220         T_Integer,
 221         T_Float,
 222         T_String,
 223         T_BitString,
 224         T_Null,
 225
 226         /*
 227          * TAGS FOR LIST NODES (pg_list.h)
 228          */
 229         T_List,
 230         T_IntList,
 231         T_OidList,
 232
 233         /*
 234          * TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
 235          */
 236         T_Query = 700,
 237         T_PlannedStmt,
 238         T_InsertStmt,
 239         T_DeleteStmt,
 240         T_UpdateStmt,
 241         T_SelectStmt,
 242         T_AlterTableStmt,
 243         T_AlterTableCmd,
 244         T_AlterDomainStmt,
 245         T_SetOperationStmt,
 246         T_GrantStmt,
 247         T_GrantRoleStmt,
 248         T_ClosePortalStmt,
 249         T_ClusterStmt,
 250         T_CopyStmt,
 251         T_CreateStmt,
 252         T_DefineStmt,
 253         T_DropStmt,
 254         T_TruncateStmt,
 255         T_CommentStmt,
 256         T_FetchStmt,
 257         T_IndexStmt,
 258         T_CreateFunctionStmt,
 259         T_AlterFunctionStmt,
 260         T_RemoveFuncStmt,
 261         T_RenameStmt,
 262         T_RuleStmt,
 263         T_NotifyStmt,
 264         T_ListenStmt,
 265         T_UnlistenStmt,
 266         T_TransactionStmt,
 267         T_ViewStmt,
 268         T_LoadStmt,
 269         T_CreateDomainStmt,
 270         T_CreatedbStmt,
 271         T_DropdbStmt,
 272         T_VacuumStmt,
 273         T_ExplainStmt,
 274         T_CreateSeqStmt,
 275         T_AlterSeqStmt,
 276         T_VariableSetStmt,
 277         T_VariableShowStmt,
 278         T_DiscardStmt,
 279         T_CreateTrigStmt,
 280         T_DropPropertyStmt,
 281         T_CreatePLangStmt,
 282         T_DropPLangStmt,
 283         T_CreateRoleStmt,
 284         T_AlterRoleStmt,
 285         T_DropRoleStmt,
 286         T_LockStmt,
 287         T_ConstraintsSetStmt,
 288         T_ReindexStmt,
 289         T_CheckPointStmt,
 290         T_CreateSchemaStmt,
 291         T_AlterDatabaseStmt,
 292         T_AlterDatabaseSetStmt,
 293         T_AlterRoleSetStmt,
 294         T_CreateConversionStmt,
 295         T_CreateCastStmt,
 296         T_DropCastStmt,
 297         T_CreateOpClassStmt,
 298         T_CreateOpFamilyStmt,
 299         T_AlterOpFamilyStmt,
 300         T_RemoveOpClassStmt,
 301         T_RemoveOpFamilyStmt,
 302         T_PrepareStmt,
 303         T_ExecuteStmt,
 304         T_DeallocateStmt,
 305         T_DeclareCursorStmt,
 306         T_CreateTableSpaceStmt,
 307         T_DropTableSpaceStmt,
 308         T_AlterObjectSchemaStmt,
 309         T_AlterOwnerStmt,
 310         T_DropOwnedStmt,
 311         T_ReassignOwnedStmt,
 312         T_CompositeTypeStmt,
 313         T_CreateEnumStmt,
 314         T_AlterTSDictionaryStmt,
 315         T_AlterTSConfigurationStmt,
 316
 317         /*
 318          * TAGS FOR PARSE TREE NODES (parsenodes.h)
 319          */
 320         T_A_Expr = 900,
 321         T_ColumnRef,
 322         T_ParamRef,
 323         T_A_Const,
 324         T_FuncCall,
 325         T_A_Indices,
 326         T_A_Indirection,
 327         T_A_ArrayExpr,
 328         T_ResTarget,
 329         T_TypeCast,
 330         T_SortBy,
 331         T_RangeSubselect,
 332         T_RangeFunction,
 333         T_TypeName,
 334         T_ColumnDef,
 335         T_IndexElem,
 336         T_Constraint,
 337         T_DefElem,
 338         T_RangeTblEntry,
 339         T_SortGroupClause,
 340         T_FkConstraint,
 341         T_PrivGrantee,
 342         T_FuncWithArgs,
 343         T_PrivTarget,
 344         T_CreateOpClassItem,
 345         T_InhRelation,
 346         T_FunctionParameter,
 347         T_LockingClause,
 348         T_RowMarkClause,
 349         T_XmlSerialize,
 350
 351         /*
 352          * TAGS FOR RANDOM OTHER STUFF
 353          *
 354          * These are objects that aren't part of parse/plan/execute node tree
 355          * structures, but we give them NodeTags anyway for identification
 356          * purposes (usually because they are involved in APIs where we want to
 357          * pass multiple object types through the same pointer).
 358          */
 359         T_TriggerData = 950,            /* in commands/trigger.h */
 360         T_ReturnSetInfo,                        /* in nodes/execnodes.h */
 361         T_TIDBitmap                                     /* in nodes/tidbitmap.h */
 362 } NodeTag;
 363
 364 /*
 365  * The first field of a node of any type is guaranteed to be the NodeTag.
 366  * Hence the type of any node can be gotten by casting it to Node. Declaring
 367  * a variable to be of Node * (instead of void *) can also facilitate
 368  * debugging.
 369  */
 370 typedef struct Node
 371 {
 372         NodeTag         type;
 373 } Node;
 374
 375 #define nodeTag(nodeptr)                (((Node*)(nodeptr))->type)
 376
 377 /*
 378  * newNode -
 379  *        create a new node of the specified size and tag the node with the
 380  *        specified tag.
 381  *
 382  * !WARNING!: Avoid using newNode directly. You should be using the
 383  *        macro makeNode.  eg. to create a Query node, use makeNode(Query)
 384  *
 385  *      There is no way to dereference the palloc'ed pointer to assign the
 386  *      tag, and also return the pointer itself, so we need a holder variable.
 387  *      Fortunately, this macro isn't recursive so we just define
 388  *      a global variable for this purpose.
 389  */
 390 extern PGDLLIMPORT Node *newNodeMacroHolder;
 391
 392 #define newNode(size, tag) \
 393 ( \
 394         AssertMacro((size) >= sizeof(Node)),            /* need the tag, at least */ \
 395         newNodeMacroHolder = (Node *) palloc0fast(size), \
 396         newNodeMacroHolder->type = (tag), \
 397         newNodeMacroHolder \
 398 )
 399
 400
 401 #define makeNode(_type_)                ((_type_ *) newNode(sizeof(_type_),T_##_type_))
 402 #define NodeSetTag(nodeptr,t)   (((Node*)(nodeptr))->type = (t))
 403
 404 #define IsA(nodeptr,_type_)             (nodeTag(nodeptr) == T_##_type_)
 405
 406 /* ----------------------------------------------------------------
 407  *                                        extern declarations follow
 408  * ----------------------------------------------------------------
 409  */
 410
 411 /*
 412  * nodes/{outfuncs.c,print.c}
 413  */
 414 extern char *nodeToString(void *obj);
 415
 416 /*
 417  * nodes/{readfuncs.c,read.c}
 418  */
 419 extern void *stringToNode(char *str);
 420
 421 /*
 422  * nodes/copyfuncs.c
 423  */
 424 extern void *copyObject(void *obj);
 425
 426 /*
 427  * nodes/equalfuncs.c
 428  */
 429 extern bool equal(void *a, void *b);
 430
 431
 432 /*
 433  * Typedefs for identifying qualifier selectivities and plan costs as such.
 434  * These are just plain "double"s, but declaring a variable as Selectivity
 435  * or Cost makes the intent more obvious.
 436  *
 437  * These could have gone into plannodes.h or some such, but many files
 438  * depend on them...
 439  */
 440 typedef double Selectivity;             /* fraction of tuples a qualifier will pass */
 441 typedef double Cost;                    /* execution cost (in page-access units) */
 442
 443
 444 /*
 445  * CmdType -
 446  *        enums for type of operation represented by a Query or PlannedStmt
 447  *
 448  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 449  */
 450 typedef enum CmdType
 451 {
 452         CMD_UNKNOWN,
 453         CMD_SELECT,                                     /* select stmt */
 454         CMD_UPDATE,                                     /* update stmt */
 455         CMD_INSERT,                                     /* insert stmt */
 456         CMD_DELETE,
 457         CMD_UTILITY,                            /* cmds like create, destroy, copy, vacuum,
 458                                                                  * etc. */
 459         CMD_NOTHING                                     /* dummy command for instead nothing rules
 460                                                                  * with qual */
 461 } CmdType;
 462
 463
 464 /*
 465  * JoinType -
 466  *        enums for types of relation joins
 467  *
 468  * JoinType determines the exact semantics of joining two relations using
 469  * a matching qualification.  For example, it tells what to do with a tuple
 470  * that has no match in the other relation.
 471  *
 472  * This is needed in both parsenodes.h and plannodes.h, so put it here...
 473  */
 474 typedef enum JoinType
 475 {
 476         /*
 477          * The canonical kinds of joins according to the SQL JOIN syntax.
 478          * Only these codes can appear in parser output (e.g., JoinExpr nodes).
 479          */
 480         JOIN_INNER,                                     /* matching tuple pairs only */
 481         JOIN_LEFT,                                      /* pairs + unmatched LHS tuples */
 482         JOIN_FULL,                                      /* pairs + unmatched LHS + unmatched RHS */
 483         JOIN_RIGHT,                                     /* pairs + unmatched RHS tuples */
 484
 485         /*
 486          * Semijoins and anti-semijoins (as defined in relational theory) do
 487          * not appear in the SQL JOIN syntax, but there are standard idioms for
 488          * representing them (e.g., using EXISTS).  The planner recognizes these
 489          * cases and converts them to joins.  So the planner and executor must
 490          * support these codes.  NOTE: in JOIN_SEMI output, it is unspecified
 491          * which matching RHS row is joined to.  In JOIN_ANTI output, the row
 492          * is guaranteed to be null-extended.
 493          */
 494         JOIN_SEMI,                                      /* 1 copy of each LHS row that has match(es) */
 495         JOIN_ANTI,                                      /* 1 copy of each LHS row that has no match */
 496
 497         /*
 498          * These codes are used internally in the planner, but are not supported
 499          * by the executor (nor, indeed, by most of the planner).
 500          */
 501         JOIN_UNIQUE_OUTER,                      /* LHS path must be made unique */
 502         JOIN_UNIQUE_INNER                       /* RHS path must be made unique */
 503
 504         /*
 505          * We might need additional join types someday.
 506          */
 507 } JoinType;
 508
 509 /*
 510  * OUTER joins are those for which pushed-down quals must behave differently
 511  * from the join's own quals.  This is in fact everything except INNER joins.
 512  * However, this macro must also exclude the JOIN_UNIQUE symbols since those
 513  * are temporary proxies for what will eventually be an INNER join.
 514  *
 515  * Note: in some places it is preferable to treat JOIN_SEMI as not being
 516  * an outer join, since it doesn't produce null-extended rows.  Be aware
 517  * of that distinction when deciding whether to use this macro.
 518  */
 519 #define IS_OUTER_JOIN(jointype) \
 520         ((jointype) > JOIN_INNER && (jointype) < JOIN_UNIQUE_OUTER)
 521
 522 #endif   /* NODES_H */