PostgreSQL Source Code  git master
nodes.h
Go to the documentation of this file.
1 /*-------------------------------------------------------------------------
2  *
3  * nodes.h
4  * Definitions for tagged nodes.
5  *
6  *
7  * Portions Copyright (c) 1996-2021, 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 inserting or deleting node types changes the numbers of other
22  * node types later in the list. This is no problem during development, since
23  * the node numbers are never stored on disk. But don't do it in a released
24  * branch, because that would represent an ABI break for extensions.
25  */
26 typedef enum NodeTag
27 {
28  T_Invalid = 0,
29 
30  /*
31  * TAGS FOR EXECUTOR NODES (execnodes.h)
32  */
41 
42  /*
43  * TAGS FOR PLAN NODES (plannodes.h)
44  */
90  /* these aren't subclasses of Plan: */
98 
99  /*
100  * TAGS FOR PLAN STATE NODES (execnodes.h)
101  *
102  * These should correspond one-to-one with Plan node types.
103  */
149 
150  /*
151  * TAGS FOR PRIMITIVE NODES (primnodes.h)
152  */
205 
206  /*
207  * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
208  *
209  * ExprState represents the evaluation state for a whole expression tree.
210  * Most Expr-based plan nodes do not have a corresponding expression state
211  * node, they're fully handled within execExpr* - but sometimes the state
212  * needs to be shared with other parts of the executor, as for example
213  * with SubPlanState, which nodeSubplan.c has to modify.
214  */
220 
221  /*
222  * TAGS FOR PLANNER NODES (pathnodes.h)
223  */
266  /* these aren't subclasses of Path: */
283 
284  /*
285  * TAGS FOR MEMORY NODES (memnodes.h)
286  */
291 
292  /*
293  * TAGS FOR VALUE NODES (value.h)
294  */
301 
302  /*
303  * TAGS FOR LIST NODES (pg_list.h)
304  */
308 
309  /*
310  * TAGS FOR EXTENSIBLE NODES (extensible.h)
311  */
313 
314  /*
315  * TAGS FOR STATEMENT NODES (mostly in parsenodes.h)
316  */
435 
436  /*
437  * TAGS FOR PARSE TREE NODES (parsenodes.h)
438  */
494 
495  /*
496  * TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
497  */
505 
506  /*
507  * TAGS FOR RANDOM OTHER STUFF
508  *
509  * These are objects that aren't part of parse/plan/execute node tree
510  * structures, but we give them NodeTags anyway for identification
511  * purposes (usually because they are involved in APIs where we want to
512  * pass multiple object types through the same pointer).
513  */
514  T_TriggerData, /* in commands/trigger.h */
515  T_EventTriggerData, /* in commands/event_trigger.h */
516  T_ReturnSetInfo, /* in nodes/execnodes.h */
517  T_WindowObjectData, /* private in nodeWindowAgg.c */
518  T_TIDBitmap, /* in nodes/tidbitmap.h */
519  T_InlineCodeBlock, /* in nodes/parsenodes.h */
520  T_FdwRoutine, /* in foreign/fdwapi.h */
521  T_IndexAmRoutine, /* in access/amapi.h */
522  T_TableAmRoutine, /* in access/tableam.h */
523  T_TsmRoutine, /* in access/tsmapi.h */
524  T_ForeignKeyCacheInfo, /* in utils/rel.h */
525  T_CallContext, /* in nodes/parsenodes.h */
526  T_SupportRequestSimplify, /* in nodes/supportnodes.h */
527  T_SupportRequestSelectivity, /* in nodes/supportnodes.h */
528  T_SupportRequestCost, /* in nodes/supportnodes.h */
529  T_SupportRequestRows, /* in nodes/supportnodes.h */
530  T_SupportRequestIndexCondition /* in nodes/supportnodes.h */
531 } NodeTag;
532 
533 /*
534  * The first field of a node of any type is guaranteed to be the NodeTag.
535  * Hence the type of any node can be gotten by casting it to Node. Declaring
536  * a variable to be of Node * (instead of void *) can also facilitate
537  * debugging.
538  */
539 typedef struct Node
540 {
542 } Node;
543 
544 #define nodeTag(nodeptr) (((const Node*)(nodeptr))->type)
545 
546 /*
547  * newNode -
548  * create a new node of the specified size and tag the node with the
549  * specified tag.
550  *
551  * !WARNING!: Avoid using newNode directly. You should be using the
552  * macro makeNode. eg. to create a Query node, use makeNode(Query)
553  *
554  * Note: the size argument should always be a compile-time constant, so the
555  * apparent risk of multiple evaluation doesn't matter in practice.
556  */
557 #ifdef __GNUC__
558 
559 /* With GCC, we can use a compound statement within an expression */
560 #define newNode(size, tag) \
561 ({ Node *_result; \
562  AssertMacro((size) >= sizeof(Node)); /* need the tag, at least */ \
563  _result = (Node *) palloc0fast(size); \
564  _result->type = (tag); \
565  _result; \
566 })
567 #else
568 
569 /*
570  * There is no way to dereference the palloc'ed pointer to assign the
571  * tag, and also return the pointer itself, so we need a holder variable.
572  * Fortunately, this macro isn't recursive so we just define
573  * a global variable for this purpose.
574  */
576 
577 #define newNode(size, tag) \
578 ( \
579  AssertMacro((size) >= sizeof(Node)), /* need the tag, at least */ \
580  newNodeMacroHolder = (Node *) palloc0fast(size), \
581  newNodeMacroHolder->type = (tag), \
582  newNodeMacroHolder \
583 )
584 #endif /* __GNUC__ */
585 
586 
587 #define makeNode(_type_) ((_type_ *) newNode(sizeof(_type_),T_##_type_))
588 #define NodeSetTag(nodeptr,t) (((Node*)(nodeptr))->type = (t))
589 
590 #define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_)
591 
592 /*
593  * castNode(type, ptr) casts ptr to "type *", and if assertions are enabled,
594  * verifies that the node has the appropriate type (using its nodeTag()).
595  *
596  * Use an inline function when assertions are enabled, to avoid multiple
597  * evaluations of the ptr argument (which could e.g. be a function call).
598  */
599 #ifdef USE_ASSERT_CHECKING
600 static inline Node *
601 castNodeImpl(NodeTag type, void *ptr)
602 {
603  Assert(ptr == NULL || nodeTag(ptr) == type);
604  return (Node *) ptr;
605 }
606 #define castNode(_type_, nodeptr) ((_type_ *) castNodeImpl(T_##_type_, nodeptr))
607 #else
608 #define castNode(_type_, nodeptr) ((_type_ *) (nodeptr))
609 #endif /* USE_ASSERT_CHECKING */
610 
611 
612 /* ----------------------------------------------------------------
613  * extern declarations follow
614  * ----------------------------------------------------------------
615  */
616 
617 /*
618  * nodes/{outfuncs.c,print.c}
619  */
620 struct Bitmapset; /* not to include bitmapset.h here */
621 struct StringInfoData; /* not to include stringinfo.h here */
622 
623 extern void outNode(struct StringInfoData *str, const void *obj);
624 extern void outToken(struct StringInfoData *str, const char *s);
625 extern void outBitmapset(struct StringInfoData *str,
626  const struct Bitmapset *bms);
627 extern void outDatum(struct StringInfoData *str, uintptr_t value,
628  int typlen, bool typbyval);
629 extern char *nodeToString(const void *obj);
630 extern char *bmsToString(const struct Bitmapset *bms);
631 
632 /*
633  * nodes/{readfuncs.c,read.c}
634  */
635 extern void *stringToNode(const char *str);
636 #ifdef WRITE_READ_PARSE_PLAN_TREES
637 extern void *stringToNodeWithLocations(const char *str);
638 #endif
639 extern struct Bitmapset *readBitmapset(void);
640 extern uintptr_t readDatum(bool typbyval);
641 extern bool *readBoolCols(int numCols);
642 extern int *readIntCols(int numCols);
643 extern Oid *readOidCols(int numCols);
644 extern int16 *readAttrNumberCols(int numCols);
645 
646 /*
647  * nodes/copyfuncs.c
648  */
649 extern void *copyObjectImpl(const void *obj);
650 
651 /* cast result back to argument type, if supported by compiler */
652 #ifdef HAVE_TYPEOF
653 #define copyObject(obj) ((typeof(obj)) copyObjectImpl(obj))
654 #else
655 #define copyObject(obj) copyObjectImpl(obj)
656 #endif
657 
658 /*
659  * nodes/equalfuncs.c
660  */
661 extern bool equal(const void *a, const void *b);
662 
663 
664 /*
665  * Typedefs for identifying qualifier selectivities and plan costs as such.
666  * These are just plain "double"s, but declaring a variable as Selectivity
667  * or Cost makes the intent more obvious.
668  *
669  * These could have gone into plannodes.h or some such, but many files
670  * depend on them...
671  */
672 typedef double Selectivity; /* fraction of tuples a qualifier will pass */
673 typedef double Cost; /* execution cost (in page-access units) */
674 
675 
676 /*
677  * CmdType -
678  * enums for type of operation represented by a Query or PlannedStmt
679  *
680  * This is needed in both parsenodes.h and plannodes.h, so put it here...
681  */
682 typedef enum CmdType
683 {
685  CMD_SELECT, /* select stmt */
686  CMD_UPDATE, /* update stmt */
687  CMD_INSERT, /* insert stmt */
689  CMD_UTILITY, /* cmds like create, destroy, copy, vacuum,
690  * etc. */
691  CMD_NOTHING /* dummy command for instead nothing rules
692  * with qual */
693 } CmdType;
694 
695 
696 /*
697  * JoinType -
698  * enums for types of relation joins
699  *
700  * JoinType determines the exact semantics of joining two relations using
701  * a matching qualification. For example, it tells what to do with a tuple
702  * that has no match in the other relation.
703  *
704  * This is needed in both parsenodes.h and plannodes.h, so put it here...
705  */
706 typedef enum JoinType
707 {
708  /*
709  * The canonical kinds of joins according to the SQL JOIN syntax. Only
710  * these codes can appear in parser output (e.g., JoinExpr nodes).
711  */
712  JOIN_INNER, /* matching tuple pairs only */
713  JOIN_LEFT, /* pairs + unmatched LHS tuples */
714  JOIN_FULL, /* pairs + unmatched LHS + unmatched RHS */
715  JOIN_RIGHT, /* pairs + unmatched RHS tuples */
716 
717  /*
718  * Semijoins and anti-semijoins (as defined in relational theory) do not
719  * appear in the SQL JOIN syntax, but there are standard idioms for
720  * representing them (e.g., using EXISTS). The planner recognizes these
721  * cases and converts them to joins. So the planner and executor must
722  * support these codes. NOTE: in JOIN_SEMI output, it is unspecified
723  * which matching RHS row is joined to. In JOIN_ANTI output, the row is
724  * guaranteed to be null-extended.
725  */
726  JOIN_SEMI, /* 1 copy of each LHS row that has match(es) */
727  JOIN_ANTI, /* 1 copy of each LHS row that has no match */
728 
729  /*
730  * These codes are used internally in the planner, but are not supported
731  * by the executor (nor, indeed, by most of the planner).
732  */
733  JOIN_UNIQUE_OUTER, /* LHS path must be made unique */
734  JOIN_UNIQUE_INNER /* RHS path must be made unique */
735 
736  /*
737  * We might need additional join types someday.
738  */
739 } JoinType;
740 
741 /*
742  * OUTER joins are those for which pushed-down quals must behave differently
743  * from the join's own quals. This is in fact everything except INNER and
744  * SEMI joins. However, this macro must also exclude the JOIN_UNIQUE symbols
745  * since those are temporary proxies for what will eventually be an INNER
746  * join.
747  *
748  * Note: semijoins are a hybrid case, but we choose to treat them as not
749  * being outer joins. This is okay principally because the SQL syntax makes
750  * it impossible to have a pushed-down qual that refers to the inner relation
751  * of a semijoin; so there is no strong need to distinguish join quals from
752  * pushed-down quals. This is convenient because for almost all purposes,
753  * quals attached to a semijoin can be treated the same as innerjoin quals.
754  */
755 #define IS_OUTER_JOIN(jointype) \
756  (((1 << (jointype)) & \
757  ((1 << JOIN_LEFT) | \
758  (1 << JOIN_FULL) | \
759  (1 << JOIN_RIGHT) | \
760  (1 << JOIN_ANTI))) != 0)
761 
762 /*
763  * AggStrategy -
764  * overall execution strategies for Agg plan nodes
765  *
766  * This is needed in both pathnodes.h and plannodes.h, so put it here...
767  */
768 typedef enum AggStrategy
769 {
770  AGG_PLAIN, /* simple agg across all input rows */
771  AGG_SORTED, /* grouped agg, input must be sorted */
772  AGG_HASHED, /* grouped agg, use internal hashtable */
773  AGG_MIXED /* grouped agg, hash and sort both used */
774 } AggStrategy;
775 
776 /*
777  * AggSplit -
778  * splitting (partial aggregation) modes for Agg plan nodes
779  *
780  * This is needed in both pathnodes.h and plannodes.h, so put it here...
781  */
782 
783 /* Primitive options supported by nodeAgg.c: */
784 #define AGGSPLITOP_COMBINE 0x01 /* substitute combinefn for transfn */
785 #define AGGSPLITOP_SKIPFINAL 0x02 /* skip finalfn, return state as-is */
786 #define AGGSPLITOP_SERIALIZE 0x04 /* apply serialfn to output */
787 #define AGGSPLITOP_DESERIALIZE 0x08 /* apply deserialfn to input */
788 
789 /* Supported operating modes (i.e., useful combinations of these options): */
790 typedef enum AggSplit
791 {
792  /* Basic, non-split aggregation: */
794  /* Initial phase of partial aggregation, with serialization: */
796  /* Final phase of partial aggregation, with deserialization: */
798 } AggSplit;
799 
800 /* Test whether an AggSplit value selects each primitive option: */
801 #define DO_AGGSPLIT_COMBINE(as) (((as) & AGGSPLITOP_COMBINE) != 0)
802 #define DO_AGGSPLIT_SKIPFINAL(as) (((as) & AGGSPLITOP_SKIPFINAL) != 0)
803 #define DO_AGGSPLIT_SERIALIZE(as) (((as) & AGGSPLITOP_SERIALIZE) != 0)
804 #define DO_AGGSPLIT_DESERIALIZE(as) (((as) & AGGSPLITOP_DESERIALIZE) != 0)
805 
806 /*
807  * SetOpCmd and SetOpStrategy -
808  * overall semantics and execution strategies for SetOp plan nodes
809  *
810  * This is needed in both pathnodes.h and plannodes.h, so put it here...
811  */
812 typedef enum SetOpCmd
813 {
818 } SetOpCmd;
819 
820 typedef enum SetOpStrategy
821 {
822  SETOP_SORTED, /* input must be sorted */
823  SETOP_HASHED /* use internal hashtable */
824 } SetOpStrategy;
825 
826 /*
827  * OnConflictAction -
828  * "ON CONFLICT" clause type of query
829  *
830  * This is needed in both parsenodes.h and plannodes.h, so put it here...
831  */
832 typedef enum OnConflictAction
833 {
834  ONCONFLICT_NONE, /* No "ON CONFLICT" clause */
835  ONCONFLICT_NOTHING, /* ON CONFLICT ... DO NOTHING */
836  ONCONFLICT_UPDATE /* ON CONFLICT ... DO UPDATE */
838 
839 /*
840  * LimitOption -
841  * LIMIT option of query
842  *
843  * This is needed in both parsenodes.h and plannodes.h, so put it here...
844  */
845 typedef enum LimitOption
846 {
847  LIMIT_OPTION_COUNT, /* FETCH FIRST... ONLY */
848  LIMIT_OPTION_WITH_TIES, /* FETCH FIRST... WITH TIES */
849  LIMIT_OPTION_DEFAULT, /* No limit present */
850 } LimitOption;
851 
852 #endif /* NODES_H */
uintptr_t readDatum(bool typbyval)
Definition: readfuncs.c:2992
signed short int16
Definition: c.h:428
Definition: nodes.h:81
void * stringToNode(const char *str)
Definition: read.c:89
Oid * readOidCols(int numCols)
Definition: readfuncs.c:3073
Definition: nodes.h:83
static struct @142 value
Definition: nodes.h:54
char * bmsToString(const struct Bitmapset *bms)
Definition: nodes.h:539
int16 * readAttrNumberCols(int numCols)
Definition: readfuncs.c:3049
Definition: nodes.h:49
Definition: nodes.h:78
double Selectivity
Definition: nodes.h:672
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
void outToken(struct StringInfoData *str, const char *s)
SetOpStrategy
Definition: nodes.h:820
#define PGDLLIMPORT
Definition: c.h:1317
JoinType
Definition: nodes.h:706
char * nodeToString(const void *obj)
Definition: outfuncs.c:4526
#define AGGSPLITOP_DESERIALIZE
Definition: nodes.h:787
Definition: nodes.h:46
Definition: nodes.h:156
#define AGGSPLITOP_COMBINE
Definition: nodes.h:784
Definition: nodes.h:80
struct Bitmapset * readBitmapset(void)
Definition: readfuncs.c:238
NodeTag type
Definition: nodes.h:541
Definition: nodes.h:153
Definition: nodes.h:305
Definition: nodes.h:158
Definition: nodes.h:157
Definition: nodes.h:318
struct Node Node
Definition: nodes.h:86
bool * readBoolCols(int numCols)
Definition: readfuncs.c:3121
#define AGGSPLITOP_SERIALIZE
Definition: nodes.h:786
#define Assert(condition)
Definition: c.h:804
void outDatum(struct StringInfoData *str, uintptr_t value, int typlen, bool typbyval)
int * readIntCols(int numCols)
Definition: readfuncs.c:3097
AggSplit
Definition: nodes.h:790
Definition: nodes.h:295
#define AGGSPLITOP_SKIPFINAL
Definition: nodes.h:785
void outBitmapset(struct StringInfoData *str, const struct Bitmapset *bms)
LimitOption
Definition: nodes.h:845
#define nodeTag(nodeptr)
Definition: nodes.h:544
Definition: nodes.h:45
Definition: nodes.h:72
PGDLLIMPORT Node * newNodeMacroHolder
Definition: nodes.c:31
Definition: nodes.h:300
Definition: nodes.h:87
void * copyObjectImpl(const void *obj)
Definition: copyfuncs.c:4948
Definition: nodes.h:297
AggStrategy
Definition: nodes.h:768
SetOpCmd
Definition: nodes.h:812
Definition: nodes.h:84
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:3105
Definition: nodes.h:230
OnConflictAction
Definition: nodes.h:832
CmdType
Definition: nodes.h:682
double Cost
Definition: nodes.h:673
Definition: nodes.h:39
void outNode(struct StringInfoData *str, const void *obj)
Definition: nodes.h:159
Definition: nodes.h:89