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relation.h
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1 /*-------------------------------------------------------------------------
2  *
3  * relation.h
4  * Definitions for planner's internal data structures.
5  *
6  *
7  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/nodes/relation.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef RELATION_H
15 #define RELATION_H
16 
17 #include "access/sdir.h"
18 #include "lib/stringinfo.h"
19 #include "nodes/params.h"
20 #include "nodes/parsenodes.h"
21 #include "storage/block.h"
22 
23 
24 /*
25  * Relids
26  * Set of relation identifiers (indexes into the rangetable).
27  */
28 typedef Bitmapset *Relids;
29 
30 /*
31  * When looking for a "cheapest path", this enum specifies whether we want
32  * cheapest startup cost or cheapest total cost.
33  */
34 typedef enum CostSelector
35 {
37 } CostSelector;
38 
39 /*
40  * The cost estimate produced by cost_qual_eval() includes both a one-time
41  * (startup) cost, and a per-tuple cost.
42  */
43 typedef struct QualCost
44 {
45  Cost startup; /* one-time cost */
46  Cost per_tuple; /* per-evaluation cost */
47 } QualCost;
48 
49 /*
50  * Costing aggregate function execution requires these statistics about
51  * the aggregates to be executed by a given Agg node. Note that the costs
52  * include the execution costs of the aggregates' argument expressions as
53  * well as the aggregate functions themselves. Also, the fields must be
54  * defined so that initializing the struct to zeroes with memset is correct.
55  */
56 typedef struct AggClauseCosts
57 {
58  int numAggs; /* total number of aggregate functions */
59  int numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
60  bool hasNonPartial; /* does any agg not support partial mode? */
61  bool hasNonSerial; /* is any partial agg non-serializable? */
62  QualCost transCost; /* total per-input-row execution costs */
63  Cost finalCost; /* total per-aggregated-row costs */
64  Size transitionSpace; /* space for pass-by-ref transition data */
66 
67 /*
68  * This enum identifies the different types of "upper" (post-scan/join)
69  * relations that we might deal with during planning.
70  */
71 typedef enum UpperRelationKind
72 {
73  UPPERREL_SETOP, /* result of UNION/INTERSECT/EXCEPT, if any */
74  UPPERREL_GROUP_AGG, /* result of grouping/aggregation, if any */
75  UPPERREL_WINDOW, /* result of window functions, if any */
76  UPPERREL_DISTINCT, /* result of "SELECT DISTINCT", if any */
77  UPPERREL_ORDERED, /* result of ORDER BY, if any */
78  UPPERREL_FINAL /* result of any remaining top-level actions */
79  /* NB: UPPERREL_FINAL must be last enum entry; it's used to size arrays */
81 
82 
83 /*----------
84  * PlannerGlobal
85  * Global information for planning/optimization
86  *
87  * PlannerGlobal holds state for an entire planner invocation; this state
88  * is shared across all levels of sub-Queries that exist in the command being
89  * planned.
90  *----------
91  */
92 typedef struct PlannerGlobal
93 {
95 
96  ParamListInfo boundParams; /* Param values provided to planner() */
97 
98  List *subplans; /* Plans for SubPlan nodes */
99 
100  List *subroots; /* PlannerInfos for SubPlan nodes */
101 
102  Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
103 
104  List *finalrtable; /* "flat" rangetable for executor */
105 
106  List *finalrowmarks; /* "flat" list of PlanRowMarks */
107 
108  List *resultRelations; /* "flat" list of integer RT indexes */
109 
110  List *nonleafResultRelations; /* "flat" list of integer RT indexes */
111 
112  List *relationOids; /* OIDs of relations the plan depends on */
113 
114  List *invalItems; /* other dependencies, as PlanInvalItems */
115 
116  int nParamExec; /* number of PARAM_EXEC Params used */
117 
118  Index lastPHId; /* highest PlaceHolderVar ID assigned */
119 
120  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
121 
122  int lastPlanNodeId; /* highest plan node ID assigned */
123 
124  bool transientPlan; /* redo plan when TransactionXmin changes? */
125 
126  bool dependsOnRole; /* is plan specific to current role? */
127 
128  bool parallelModeOK; /* parallel mode potentially OK? */
129 
130  bool parallelModeNeeded; /* parallel mode actually required? */
131 
132  char maxParallelHazard; /* worst PROPARALLEL hazard level */
133 } PlannerGlobal;
134 
135 /* macro for fetching the Plan associated with a SubPlan node */
136 #define planner_subplan_get_plan(root, subplan) \
137  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
138 
139 
140 /*----------
141  * PlannerInfo
142  * Per-query information for planning/optimization
143  *
144  * This struct is conventionally called "root" in all the planner routines.
145  * It holds links to all of the planner's working state, in addition to the
146  * original Query. Note that at present the planner extensively modifies
147  * the passed-in Query data structure; someday that should stop.
148  *----------
149  */
150 typedef struct PlannerInfo
151 {
153 
154  Query *parse; /* the Query being planned */
155 
156  PlannerGlobal *glob; /* global info for current planner run */
157 
158  Index query_level; /* 1 at the outermost Query */
159 
160  struct PlannerInfo *parent_root; /* NULL at outermost Query */
161 
162  /*
163  * plan_params contains the expressions that this query level needs to
164  * make available to a lower query level that is currently being planned.
165  * outer_params contains the paramIds of PARAM_EXEC Params that outer
166  * query levels will make available to this query level.
167  */
168  List *plan_params; /* list of PlannerParamItems, see below */
170 
171  /*
172  * simple_rel_array holds pointers to "base rels" and "other rels" (see
173  * comments for RelOptInfo for more info). It is indexed by rangetable
174  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
175  * does not correspond to a base relation, such as a join RTE or an
176  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
177  */
178  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
179  int simple_rel_array_size; /* allocated size of array */
180 
181  /*
182  * simple_rte_array is the same length as simple_rel_array and holds
183  * pointers to the associated rangetable entries. This lets us avoid
184  * rt_fetch(), which can be a bit slow once large inheritance sets have
185  * been expanded.
186  */
187  RangeTblEntry **simple_rte_array; /* rangetable as an array */
188 
189  /*
190  * all_baserels is a Relids set of all base relids (but not "other"
191  * relids) in the query; that is, the Relids identifier of the final join
192  * we need to form. This is computed in make_one_rel, just before we
193  * start making Paths.
194  */
196 
197  /*
198  * nullable_baserels is a Relids set of base relids that are nullable by
199  * some outer join in the jointree; these are rels that are potentially
200  * nullable below the WHERE clause, SELECT targetlist, etc. This is
201  * computed in deconstruct_jointree.
202  */
204 
205  /*
206  * join_rel_list is a list of all join-relation RelOptInfos we have
207  * considered in this planning run. For small problems we just scan the
208  * list to do lookups, but when there are many join relations we build a
209  * hash table for faster lookups. The hash table is present and valid
210  * when join_rel_hash is not NULL. Note that we still maintain the list
211  * even when using the hash table for lookups; this simplifies life for
212  * GEQO.
213  */
214  List *join_rel_list; /* list of join-relation RelOptInfos */
215  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
216 
217  /*
218  * When doing a dynamic-programming-style join search, join_rel_level[k]
219  * is a list of all join-relation RelOptInfos of level k, and
220  * join_cur_level is the current level. New join-relation RelOptInfos are
221  * automatically added to the join_rel_level[join_cur_level] list.
222  * join_rel_level is NULL if not in use.
223  */
224  List **join_rel_level; /* lists of join-relation RelOptInfos */
225  int join_cur_level; /* index of list being extended */
226 
227  List *init_plans; /* init SubPlans for query */
228 
229  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
230 
231  List *multiexpr_params; /* List of Lists of Params for
232  * MULTIEXPR subquery outputs */
233 
234  List *eq_classes; /* list of active EquivalenceClasses */
235 
236  List *canon_pathkeys; /* list of "canonical" PathKeys */
237 
238  List *left_join_clauses; /* list of RestrictInfos for
239  * mergejoinable outer join clauses
240  * w/nonnullable var on left */
241 
242  List *right_join_clauses; /* list of RestrictInfos for
243  * mergejoinable outer join clauses
244  * w/nonnullable var on right */
245 
246  List *full_join_clauses; /* list of RestrictInfos for
247  * mergejoinable full join clauses */
248 
249  List *join_info_list; /* list of SpecialJoinInfos */
250 
251  List *append_rel_list; /* list of AppendRelInfos */
252 
253  List *pcinfo_list; /* list of PartitionedChildRelInfos */
254 
255  List *rowMarks; /* list of PlanRowMarks */
256 
257  List *placeholder_list; /* list of PlaceHolderInfos */
258 
259  List *fkey_list; /* list of ForeignKeyOptInfos */
260 
261  List *query_pathkeys; /* desired pathkeys for query_planner() */
262 
263  List *group_pathkeys; /* groupClause pathkeys, if any */
264  List *window_pathkeys; /* pathkeys of bottom window, if any */
265  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
266  List *sort_pathkeys; /* sortClause pathkeys, if any */
267 
268  List *initial_rels; /* RelOptInfos we are now trying to join */
269 
270  /* Use fetch_upper_rel() to get any particular upper rel */
271  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
272 
273  /* Result tlists chosen by grouping_planner for upper-stage processing */
275 
276  /*
277  * grouping_planner passes back its final processed targetlist here, for
278  * use in relabeling the topmost tlist of the finished Plan.
279  */
281 
282  /* Fields filled during create_plan() for use in setrefs.c */
283  AttrNumber *grouping_map; /* for GroupingFunc fixup */
284  List *minmax_aggs; /* List of MinMaxAggInfos */
285 
286  MemoryContext planner_cxt; /* context holding PlannerInfo */
287 
288  double total_table_pages; /* # of pages in all tables of query */
289 
290  double tuple_fraction; /* tuple_fraction passed to query_planner */
291  double limit_tuples; /* limit_tuples passed to query_planner */
292 
293  Index qual_security_level; /* minimum security_level for quals */
294  /* Note: qual_security_level is zero if there are no securityQuals */
295 
296  bool hasInheritedTarget; /* true if parse->resultRelation is an
297  * inheritance child rel */
298  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
299  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
300  bool hasDeletedRTEs; /* true if any RTE was deleted from jointree */
301  bool hasHavingQual; /* true if havingQual was non-null */
302  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
303  * pseudoconstant = true */
304  bool hasRecursion; /* true if planning a recursive WITH item */
305 
306  /* These fields are used only when hasRecursion is true: */
307  int wt_param_id; /* PARAM_EXEC ID for the work table */
308  struct Path *non_recursive_path; /* a path for non-recursive term */
309 
310  /* These fields are workspace for createplan.c */
311  Relids curOuterRels; /* outer rels above current node */
312  List *curOuterParams; /* not-yet-assigned NestLoopParams */
313 
314  /* optional private data for join_search_hook, e.g., GEQO */
316 } PlannerInfo;
317 
318 
319 /*
320  * In places where it's known that simple_rte_array[] must have been prepared
321  * already, we just index into it to fetch RTEs. In code that might be
322  * executed before or after entering query_planner(), use this macro.
323  */
324 #define planner_rt_fetch(rti, root) \
325  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
326  rt_fetch(rti, (root)->parse->rtable))
327 
328 
329 /*----------
330  * RelOptInfo
331  * Per-relation information for planning/optimization
332  *
333  * For planning purposes, a "base rel" is either a plain relation (a table)
334  * or the output of a sub-SELECT or function that appears in the range table.
335  * In either case it is uniquely identified by an RT index. A "joinrel"
336  * is the joining of two or more base rels. A joinrel is identified by
337  * the set of RT indexes for its component baserels. We create RelOptInfo
338  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
339  * simple_rel_array and join_rel_list respectively.
340  *
341  * Note that there is only one joinrel for any given set of component
342  * baserels, no matter what order we assemble them in; so an unordered
343  * set is the right datatype to identify it with.
344  *
345  * We also have "other rels", which are like base rels in that they refer to
346  * single RT indexes; but they are not part of the join tree, and are given
347  * a different RelOptKind to identify them.
348  * Currently the only kind of otherrels are those made for member relations
349  * of an "append relation", that is an inheritance set or UNION ALL subquery.
350  * An append relation has a parent RTE that is a base rel, which represents
351  * the entire append relation. The member RTEs are otherrels. The parent
352  * is present in the query join tree but the members are not. The member
353  * RTEs and otherrels are used to plan the scans of the individual tables or
354  * subqueries of the append set; then the parent baserel is given Append
355  * and/or MergeAppend paths comprising the best paths for the individual
356  * member rels. (See comments for AppendRelInfo for more information.)
357  *
358  * At one time we also made otherrels to represent join RTEs, for use in
359  * handling join alias Vars. Currently this is not needed because all join
360  * alias Vars are expanded to non-aliased form during preprocess_expression.
361  *
362  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
363  * that describe post-scan/join processing steps, such as aggregation.
364  * Many of the fields in these RelOptInfos are meaningless, but their Path
365  * fields always hold Paths showing ways to do that processing step.
366  *
367  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
368  * that we have proven we don't need to join after all.
369  *
370  * Parts of this data structure are specific to various scan and join
371  * mechanisms. It didn't seem worth creating new node types for them.
372  *
373  * relids - Set of base-relation identifiers; it is a base relation
374  * if there is just one, a join relation if more than one
375  * rows - estimated number of tuples in the relation after restriction
376  * clauses have been applied (ie, output rows of a plan for it)
377  * consider_startup - true if there is any value in keeping plain paths for
378  * this rel on the basis of having cheap startup cost
379  * consider_param_startup - the same for parameterized paths
380  * reltarget - Default Path output tlist for this rel; normally contains
381  * Var and PlaceHolderVar nodes for the values we need to
382  * output from this relation.
383  * List is in no particular order, but all rels of an
384  * appendrel set must use corresponding orders.
385  * NOTE: in an appendrel child relation, may contain
386  * arbitrary expressions pulled up from a subquery!
387  * pathlist - List of Path nodes, one for each potentially useful
388  * method of generating the relation
389  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
390  * cheapest_startup_path - the pathlist member with lowest startup cost
391  * (regardless of ordering) among the unparameterized paths;
392  * or NULL if there is no unparameterized path
393  * cheapest_total_path - the pathlist member with lowest total cost
394  * (regardless of ordering) among the unparameterized paths;
395  * or if there is no unparameterized path, the path with lowest
396  * total cost among the paths with minimum parameterization
397  * cheapest_unique_path - for caching cheapest path to produce unique
398  * (no duplicates) output from relation; NULL if not yet requested
399  * cheapest_parameterized_paths - best paths for their parameterizations;
400  * always includes cheapest_total_path, even if that's unparameterized
401  * direct_lateral_relids - rels this rel has direct LATERAL references to
402  * lateral_relids - required outer rels for LATERAL, as a Relids set
403  * (includes both direct and indirect lateral references)
404  *
405  * If the relation is a base relation it will have these fields set:
406  *
407  * relid - RTE index (this is redundant with the relids field, but
408  * is provided for convenience of access)
409  * rtekind - distinguishes plain relation, subquery, or function RTE
410  * min_attr, max_attr - range of valid AttrNumbers for rel
411  * attr_needed - array of bitmapsets indicating the highest joinrel
412  * in which each attribute is needed; if bit 0 is set then
413  * the attribute is needed as part of final targetlist
414  * attr_widths - cache space for per-attribute width estimates;
415  * zero means not computed yet
416  * lateral_vars - lateral cross-references of rel, if any (list of
417  * Vars and PlaceHolderVars)
418  * lateral_referencers - relids of rels that reference this one laterally
419  * (includes both direct and indirect lateral references)
420  * indexlist - list of IndexOptInfo nodes for relation's indexes
421  * (always NIL if it's not a table)
422  * pages - number of disk pages in relation (zero if not a table)
423  * tuples - number of tuples in relation (not considering restrictions)
424  * allvisfrac - fraction of disk pages that are marked all-visible
425  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
426  * subplan_params - list of PlannerParamItems to be passed to subquery
427  *
428  * Note: for a subquery, tuples and subroot are not set immediately
429  * upon creation of the RelOptInfo object; they are filled in when
430  * set_subquery_pathlist processes the object.
431  *
432  * For otherrels that are appendrel members, these fields are filled
433  * in just as for a baserel, except we don't bother with lateral_vars.
434  *
435  * If the relation is either a foreign table or a join of foreign tables that
436  * all belong to the same foreign server and are assigned to the same user to
437  * check access permissions as (cf checkAsUser), these fields will be set:
438  *
439  * serverid - OID of foreign server, if foreign table (else InvalidOid)
440  * userid - OID of user to check access as (InvalidOid means current user)
441  * useridiscurrent - we've assumed that userid equals current user
442  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
443  * fdw_private - private state for FDW, if foreign table (else NULL)
444  *
445  * Two fields are used to cache knowledge acquired during the join search
446  * about whether this rel is provably unique when being joined to given other
447  * relation(s), ie, it can have at most one row matching any given row from
448  * that join relation. Currently we only attempt such proofs, and thus only
449  * populate these fields, for base rels; but someday they might be used for
450  * join rels too:
451  *
452  * unique_for_rels - list of Relid sets, each one being a set of other
453  * rels for which this one has been proven unique
454  * non_unique_for_rels - list of Relid sets, each one being a set of
455  * other rels for which we have tried and failed to prove
456  * this one unique
457  *
458  * The presence of the remaining fields depends on the restrictions
459  * and joins that the relation participates in:
460  *
461  * baserestrictinfo - List of RestrictInfo nodes, containing info about
462  * each non-join qualification clause in which this relation
463  * participates (only used for base rels)
464  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
465  * clauses at a single tuple (only used for base rels)
466  * baserestrict_min_security - Smallest security_level found among
467  * clauses in baserestrictinfo
468  * joininfo - List of RestrictInfo nodes, containing info about each
469  * join clause in which this relation participates (but
470  * note this excludes clauses that might be derivable from
471  * EquivalenceClasses)
472  * has_eclass_joins - flag that EquivalenceClass joins are possible
473  *
474  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
475  * base rels, because for a join rel the set of clauses that are treated as
476  * restrict clauses varies depending on which sub-relations we choose to join.
477  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
478  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
479  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
480  * and should not be processed again at the level of {1 2 3}.) Therefore,
481  * the restrictinfo list in the join case appears in individual JoinPaths
482  * (field joinrestrictinfo), not in the parent relation. But it's OK for
483  * the RelOptInfo to store the joininfo list, because that is the same
484  * for a given rel no matter how we form it.
485  *
486  * We store baserestrictcost in the RelOptInfo (for base relations) because
487  * we know we will need it at least once (to price the sequential scan)
488  * and may need it multiple times to price index scans.
489  *----------
490  */
491 typedef enum RelOptKind
492 {
498 } RelOptKind;
499 
500 /*
501  * Is the given relation a simple relation i.e a base or "other" member
502  * relation?
503  */
504 #define IS_SIMPLE_REL(rel) \
505  ((rel)->reloptkind == RELOPT_BASEREL || \
506  (rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
507 
508 /* Is the given relation a join relation? */
509 #define IS_JOIN_REL(rel) ((rel)->reloptkind == RELOPT_JOINREL)
510 
511 /* Is the given relation an upper relation? */
512 #define IS_UPPER_REL(rel) ((rel)->reloptkind == RELOPT_UPPER_REL)
513 
514 /* Is the given relation an "other" relation? */
515 #define IS_OTHER_REL(rel) ((rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
516 
517 typedef struct RelOptInfo
518 {
520 
522 
523  /* all relations included in this RelOptInfo */
524  Relids relids; /* set of base relids (rangetable indexes) */
525 
526  /* size estimates generated by planner */
527  double rows; /* estimated number of result tuples */
528 
529  /* per-relation planner control flags */
530  bool consider_startup; /* keep cheap-startup-cost paths? */
531  bool consider_param_startup; /* ditto, for parameterized paths? */
532  bool consider_parallel; /* consider parallel paths? */
533 
534  /* default result targetlist for Paths scanning this relation */
535  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
536 
537  /* materialization information */
538  List *pathlist; /* Path structures */
539  List *ppilist; /* ParamPathInfos used in pathlist */
540  List *partial_pathlist; /* partial Paths */
545 
546  /* parameterization information needed for both base rels and join rels */
547  /* (see also lateral_vars and lateral_referencers) */
548  Relids direct_lateral_relids; /* rels directly laterally referenced */
549  Relids lateral_relids; /* minimum parameterization of rel */
550 
551  /* information about a base rel (not set for join rels!) */
553  Oid reltablespace; /* containing tablespace */
554  RTEKind rtekind; /* RELATION, SUBQUERY, or FUNCTION */
555  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
556  AttrNumber max_attr; /* largest attrno of rel */
557  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
558  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
559  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
560  Relids lateral_referencers; /* rels that reference me laterally */
561  List *indexlist; /* list of IndexOptInfo */
562  List *statlist; /* list of StatisticExtInfo */
563  BlockNumber pages; /* size estimates derived from pg_class */
564  double tuples;
565  double allvisfrac;
566  PlannerInfo *subroot; /* if subquery */
567  List *subplan_params; /* if subquery */
568  int rel_parallel_workers; /* wanted number of parallel workers */
569 
570  /* Information about foreign tables and foreign joins */
571  Oid serverid; /* identifies server for the table or join */
572  Oid userid; /* identifies user to check access as */
573  bool useridiscurrent; /* join is only valid for current user */
574  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
576  void *fdw_private;
577 
578  /* cache space for remembering if we have proven this relation unique */
579  List *unique_for_rels; /* known unique for these other relid set(s) */
580  List *non_unique_for_rels; /* known not unique for these set(s) */
581 
582  /* used by various scans and joins: */
583  List *baserestrictinfo; /* RestrictInfo structures (if base
584  * rel) */
585  QualCost baserestrictcost; /* cost of evaluating the above */
586  Index baserestrict_min_security; /* min security_level found in
587  * baserestrictinfo */
588  List *joininfo; /* RestrictInfo structures for join clauses
589  * involving this rel */
590  bool has_eclass_joins; /* T means joininfo is incomplete */
591 
592  /* used by "other" relations */
593  Relids top_parent_relids; /* Relids of topmost parents */
594 } RelOptInfo;
595 
596 /*
597  * IndexOptInfo
598  * Per-index information for planning/optimization
599  *
600  * indexkeys[], indexcollations[], opfamily[], and opcintype[]
601  * each have ncolumns entries.
602  *
603  * sortopfamily[], reverse_sort[], and nulls_first[] likewise have
604  * ncolumns entries, if the index is ordered; but if it is unordered,
605  * those pointers are NULL.
606  *
607  * Zeroes in the indexkeys[] array indicate index columns that are
608  * expressions; there is one element in indexprs for each such column.
609  *
610  * For an ordered index, reverse_sort[] and nulls_first[] describe the
611  * sort ordering of a forward indexscan; we can also consider a backward
612  * indexscan, which will generate the reverse ordering.
613  *
614  * The indexprs and indpred expressions have been run through
615  * prepqual.c and eval_const_expressions() for ease of matching to
616  * WHERE clauses. indpred is in implicit-AND form.
617  *
618  * indextlist is a TargetEntry list representing the index columns.
619  * It provides an equivalent base-relation Var for each simple column,
620  * and links to the matching indexprs element for each expression column.
621  *
622  * While most of these fields are filled when the IndexOptInfo is created
623  * (by plancat.c), indrestrictinfo and predOK are set later, in
624  * check_index_predicates().
625  */
626 typedef struct IndexOptInfo
627 {
629 
630  Oid indexoid; /* OID of the index relation */
631  Oid reltablespace; /* tablespace of index (not table) */
632  RelOptInfo *rel; /* back-link to index's table */
633 
634  /* index-size statistics (from pg_class and elsewhere) */
635  BlockNumber pages; /* number of disk pages in index */
636  double tuples; /* number of index tuples in index */
637  int tree_height; /* index tree height, or -1 if unknown */
638 
639  /* index descriptor information */
640  int ncolumns; /* number of columns in index */
641  int *indexkeys; /* column numbers of index's keys, or 0 */
642  Oid *indexcollations; /* OIDs of collations of index columns */
643  Oid *opfamily; /* OIDs of operator families for columns */
644  Oid *opcintype; /* OIDs of opclass declared input data types */
645  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
646  bool *reverse_sort; /* is sort order descending? */
647  bool *nulls_first; /* do NULLs come first in the sort order? */
648  bool *canreturn; /* which index cols can be returned in an
649  * index-only scan? */
650  Oid relam; /* OID of the access method (in pg_am) */
651 
652  List *indexprs; /* expressions for non-simple index columns */
653  List *indpred; /* predicate if a partial index, else NIL */
654 
655  List *indextlist; /* targetlist representing index columns */
656 
657  List *indrestrictinfo;/* parent relation's baserestrictinfo list,
658  * less any conditions implied by the index's
659  * predicate (unless it's a target rel, see
660  * comments in check_index_predicates()) */
661 
662  bool predOK; /* true if index predicate matches query */
663  bool unique; /* true if a unique index */
664  bool immediate; /* is uniqueness enforced immediately? */
665  bool hypothetical; /* true if index doesn't really exist */
666 
667  /* Remaining fields are copied from the index AM's API struct: */
668  bool amcanorderbyop; /* does AM support order by operator result? */
669  bool amoptionalkey; /* can query omit key for the first column? */
670  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
671  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
672  bool amhasgettuple; /* does AM have amgettuple interface? */
673  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
674  bool amcanparallel; /* does AM support parallel scan? */
675  /* Rather than include amapi.h here, we declare amcostestimate like this */
676  void (*amcostestimate) (); /* AM's cost estimator */
677 } IndexOptInfo;
678 
679 /*
680  * ForeignKeyOptInfo
681  * Per-foreign-key information for planning/optimization
682  *
683  * The per-FK-column arrays can be fixed-size because we allow at most
684  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
685  * nkeys valid entries.
686  */
687 typedef struct ForeignKeyOptInfo
688 {
690 
691  /* Basic data about the foreign key (fetched from catalogs): */
692  Index con_relid; /* RT index of the referencing table */
693  Index ref_relid; /* RT index of the referenced table */
694  int nkeys; /* number of columns in the foreign key */
695  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
696  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
697  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
698 
699  /* Derived info about whether FK's equality conditions match the query: */
700  int nmatched_ec; /* # of FK cols matched by ECs */
701  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
702  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
703  /* Pointer to eclass matching each column's condition, if there is one */
705  /* List of non-EC RestrictInfos matching each column's condition */
708 
709 /*
710  * StatisticExtInfo
711  * Information about extended statistics for planning/optimization
712  *
713  * Each pg_statistic_ext row is represented by one or more nodes of this
714  * type, or even zero if ANALYZE has not computed them.
715  */
716 typedef struct StatisticExtInfo
717 {
719 
720  Oid statOid; /* OID of the statistics row */
721  RelOptInfo *rel; /* back-link to statistic's table */
722  char kind; /* statistic kind of this entry */
723  Bitmapset *keys; /* attnums of the columns covered */
725 
726 /*
727  * EquivalenceClasses
728  *
729  * Whenever we can determine that a mergejoinable equality clause A = B is
730  * not delayed by any outer join, we create an EquivalenceClass containing
731  * the expressions A and B to record this knowledge. If we later find another
732  * equivalence B = C, we add C to the existing EquivalenceClass; this may
733  * require merging two existing EquivalenceClasses. At the end of the qual
734  * distribution process, we have sets of values that are known all transitively
735  * equal to each other, where "equal" is according to the rules of the btree
736  * operator family(s) shown in ec_opfamilies, as well as the collation shown
737  * by ec_collation. (We restrict an EC to contain only equalities whose
738  * operators belong to the same set of opfamilies. This could probably be
739  * relaxed, but for now it's not worth the trouble, since nearly all equality
740  * operators belong to only one btree opclass anyway. Similarly, we suppose
741  * that all or none of the input datatypes are collatable, so that a single
742  * collation value is sufficient.)
743  *
744  * We also use EquivalenceClasses as the base structure for PathKeys, letting
745  * us represent knowledge about different sort orderings being equivalent.
746  * Since every PathKey must reference an EquivalenceClass, we will end up
747  * with single-member EquivalenceClasses whenever a sort key expression has
748  * not been equivalenced to anything else. It is also possible that such an
749  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
750  * which is a case that can't arise otherwise since clauses containing
751  * volatile functions are never considered mergejoinable. We mark such
752  * EquivalenceClasses specially to prevent them from being merged with
753  * ordinary EquivalenceClasses. Also, for volatile expressions we have
754  * to be careful to match the EquivalenceClass to the correct targetlist
755  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
756  * So we record the SortGroupRef of the originating sort clause.
757  *
758  * We allow equality clauses appearing below the nullable side of an outer join
759  * to form EquivalenceClasses, but these have a slightly different meaning:
760  * the included values might be all NULL rather than all the same non-null
761  * values. See src/backend/optimizer/README for more on that point.
762  *
763  * NB: if ec_merged isn't NULL, this class has been merged into another, and
764  * should be ignored in favor of using the pointed-to class.
765  */
766 typedef struct EquivalenceClass
767 {
769 
770  List *ec_opfamilies; /* btree operator family OIDs */
771  Oid ec_collation; /* collation, if datatypes are collatable */
772  List *ec_members; /* list of EquivalenceMembers */
773  List *ec_sources; /* list of generating RestrictInfos */
774  List *ec_derives; /* list of derived RestrictInfos */
775  Relids ec_relids; /* all relids appearing in ec_members, except
776  * for child members (see below) */
777  bool ec_has_const; /* any pseudoconstants in ec_members? */
778  bool ec_has_volatile; /* the (sole) member is a volatile expr */
779  bool ec_below_outer_join; /* equivalence applies below an OJ */
780  bool ec_broken; /* failed to generate needed clauses? */
781  Index ec_sortref; /* originating sortclause label, or 0 */
782  Index ec_min_security; /* minimum security_level in ec_sources */
783  Index ec_max_security; /* maximum security_level in ec_sources */
784  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
786 
787 /*
788  * If an EC contains a const and isn't below-outer-join, any PathKey depending
789  * on it must be redundant, since there's only one possible value of the key.
790  */
791 #define EC_MUST_BE_REDUNDANT(eclass) \
792  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
793 
794 /*
795  * EquivalenceMember - one member expression of an EquivalenceClass
796  *
797  * em_is_child signifies that this element was built by transposing a member
798  * for an appendrel parent relation to represent the corresponding expression
799  * for an appendrel child. These members are used for determining the
800  * pathkeys of scans on the child relation and for explicitly sorting the
801  * child when necessary to build a MergeAppend path for the whole appendrel
802  * tree. An em_is_child member has no impact on the properties of the EC as a
803  * whole; in particular the EC's ec_relids field does NOT include the child
804  * relation. An em_is_child member should never be marked em_is_const nor
805  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
806  * members are not really full-fledged members of the EC, but just reflections
807  * or doppelgangers of real members. Most operations on EquivalenceClasses
808  * should ignore em_is_child members, and those that don't should test
809  * em_relids to make sure they only consider relevant members.
810  *
811  * em_datatype is usually the same as exprType(em_expr), but can be
812  * different when dealing with a binary-compatible opfamily; in particular
813  * anyarray_ops would never work without this. Use em_datatype when
814  * looking up a specific btree operator to work with this expression.
815  */
816 typedef struct EquivalenceMember
817 {
819 
820  Expr *em_expr; /* the expression represented */
821  Relids em_relids; /* all relids appearing in em_expr */
822  Relids em_nullable_relids; /* nullable by lower outer joins */
823  bool em_is_const; /* expression is pseudoconstant? */
824  bool em_is_child; /* derived version for a child relation? */
825  Oid em_datatype; /* the "nominal type" used by the opfamily */
827 
828 /*
829  * PathKeys
830  *
831  * The sort ordering of a path is represented by a list of PathKey nodes.
832  * An empty list implies no known ordering. Otherwise the first item
833  * represents the primary sort key, the second the first secondary sort key,
834  * etc. The value being sorted is represented by linking to an
835  * EquivalenceClass containing that value and including pk_opfamily among its
836  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
837  * This is a convenient method because it makes it trivial to detect
838  * equivalent and closely-related orderings. (See optimizer/README for more
839  * information.)
840  *
841  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
842  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
843  * index types will use btree-compatible strategy numbers.
844  */
845 typedef struct PathKey
846 {
848 
849  EquivalenceClass *pk_eclass; /* the value that is ordered */
850  Oid pk_opfamily; /* btree opfamily defining the ordering */
851  int pk_strategy; /* sort direction (ASC or DESC) */
852  bool pk_nulls_first; /* do NULLs come before normal values? */
853 } PathKey;
854 
855 
856 /*
857  * PathTarget
858  *
859  * This struct contains what we need to know during planning about the
860  * targetlist (output columns) that a Path will compute. Each RelOptInfo
861  * includes a default PathTarget, which its individual Paths may simply
862  * reference. However, in some cases a Path may compute outputs different
863  * from other Paths, and in that case we make a custom PathTarget for it.
864  * For example, an indexscan might return index expressions that would
865  * otherwise need to be explicitly calculated. (Note also that "upper"
866  * relations generally don't have useful default PathTargets.)
867  *
868  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
869  * though those will appear in finished Plans.
870  *
871  * sortgrouprefs[] is an array of the same length as exprs, containing the
872  * corresponding sort/group refnos, or zeroes for expressions not referenced
873  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
874  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
875  * we have not identified sort/group columns in this tlist. This allows us to
876  * deal with sort/group refnos when needed with less expense than including
877  * TargetEntry nodes in the exprs list.
878  */
879 typedef struct PathTarget
880 {
882  List *exprs; /* list of expressions to be computed */
883  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
884  QualCost cost; /* cost of evaluating the expressions */
885  int width; /* estimated avg width of result tuples */
886 } PathTarget;
887 
888 /* Convenience macro to get a sort/group refno from a PathTarget */
889 #define get_pathtarget_sortgroupref(target, colno) \
890  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
891 
892 
893 /*
894  * ParamPathInfo
895  *
896  * All parameterized paths for a given relation with given required outer rels
897  * link to a single ParamPathInfo, which stores common information such as
898  * the estimated rowcount for this parameterization. We do this partly to
899  * avoid recalculations, but mostly to ensure that the estimated rowcount
900  * is in fact the same for every such path.
901  *
902  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
903  * in join cases it's NIL because the set of relevant clauses varies depending
904  * on how the join is formed. The relevant clauses will appear in each
905  * parameterized join path's joinrestrictinfo list, instead.
906  */
907 typedef struct ParamPathInfo
908 {
910 
911  Relids ppi_req_outer; /* rels supplying parameters used by path */
912  double ppi_rows; /* estimated number of result tuples */
913  List *ppi_clauses; /* join clauses available from outer rels */
914 } ParamPathInfo;
915 
916 
917 /*
918  * Type "Path" is used as-is for sequential-scan paths, as well as some other
919  * simple plan types that we don't need any extra information in the path for.
920  * For other path types it is the first component of a larger struct.
921  *
922  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
923  * It is partially redundant with the Path's NodeTag, but allows us to use
924  * the same Path type for multiple Plan types when there is no need to
925  * distinguish the Plan type during path processing.
926  *
927  * "parent" identifies the relation this Path scans, and "pathtarget"
928  * describes the precise set of output columns the Path would compute.
929  * In simple cases all Paths for a given rel share the same targetlist,
930  * which we represent by having path->pathtarget equal to parent->reltarget.
931  *
932  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
933  * relation(s) that provide parameter values to each scan of this path.
934  * That means this path can only be joined to those rels by means of nestloop
935  * joins with this path on the inside. Also note that a parameterized path
936  * is responsible for testing all "movable" joinclauses involving this rel
937  * and the specified outer rel(s).
938  *
939  * "rows" is the same as parent->rows in simple paths, but in parameterized
940  * paths and UniquePaths it can be less than parent->rows, reflecting the
941  * fact that we've filtered by extra join conditions or removed duplicates.
942  *
943  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
944  * ordering of the path's output rows.
945  */
946 typedef struct Path
947 {
949 
950  NodeTag pathtype; /* tag identifying scan/join method */
951 
952  RelOptInfo *parent; /* the relation this path can build */
953  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
954 
955  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
956 
957  bool parallel_aware; /* engage parallel-aware logic? */
958  bool parallel_safe; /* OK to use as part of parallel plan? */
959  int parallel_workers; /* desired # of workers; 0 = not
960  * parallel */
961 
962  /* estimated size/costs for path (see costsize.c for more info) */
963  double rows; /* estimated number of result tuples */
964  Cost startup_cost; /* cost expended before fetching any tuples */
965  Cost total_cost; /* total cost (assuming all tuples fetched) */
966 
967  List *pathkeys; /* sort ordering of path's output */
968  /* pathkeys is a List of PathKey nodes; see above */
969 } Path;
970 
971 /* Macro for extracting a path's parameterization relids; beware double eval */
972 #define PATH_REQ_OUTER(path) \
973  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
974 
975 /*----------
976  * IndexPath represents an index scan over a single index.
977  *
978  * This struct is used for both regular indexscans and index-only scans;
979  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
980  *
981  * 'indexinfo' is the index to be scanned.
982  *
983  * 'indexclauses' is a list of index qualification clauses, with implicit
984  * AND semantics across the list. Each clause is a RestrictInfo node from
985  * the query's WHERE or JOIN conditions. An empty list implies a full
986  * index scan.
987  *
988  * 'indexquals' has the same structure as 'indexclauses', but it contains
989  * the actual index qual conditions that can be used with the index.
990  * In simple cases this is identical to 'indexclauses', but when special
991  * indexable operators appear in 'indexclauses', they are replaced by the
992  * derived indexscannable conditions in 'indexquals'.
993  *
994  * 'indexqualcols' is an integer list of index column numbers (zero-based)
995  * of the same length as 'indexquals', showing which index column each qual
996  * is meant to be used with. 'indexquals' is required to be ordered by
997  * index column, so 'indexqualcols' must form a nondecreasing sequence.
998  * (The order of multiple quals for the same index column is unspecified.)
999  *
1000  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
1001  * been found to be usable as ordering operators for an amcanorderbyop index.
1002  * The list must match the path's pathkeys, ie, one expression per pathkey
1003  * in the same order. These are not RestrictInfos, just bare expressions,
1004  * since they generally won't yield booleans. Also, unlike the case for
1005  * quals, it's guaranteed that each expression has the index key on the left
1006  * side of the operator.
1007  *
1008  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
1009  * of the same length as 'indexorderbys', showing which index column each
1010  * ORDER BY expression is meant to be used with. (There is no restriction
1011  * on which index column each ORDER BY can be used with.)
1012  *
1013  * 'indexscandir' is one of:
1014  * ForwardScanDirection: forward scan of an ordered index
1015  * BackwardScanDirection: backward scan of an ordered index
1016  * NoMovementScanDirection: scan of an unordered index, or don't care
1017  * (The executor doesn't care whether it gets ForwardScanDirection or
1018  * NoMovementScanDirection for an indexscan, but the planner wants to
1019  * distinguish ordered from unordered indexes for building pathkeys.)
1020  *
1021  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
1022  * we need not recompute them when considering using the same index in a
1023  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
1024  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
1025  *----------
1026  */
1027 typedef struct IndexPath
1028 {
1039 } IndexPath;
1040 
1041 /*
1042  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
1043  * instead of directly accessing the heap, followed by AND/OR combinations
1044  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
1045  * Note that the output is always considered unordered, since it will come
1046  * out in physical heap order no matter what the underlying indexes did.
1047  *
1048  * The individual indexscans are represented by IndexPath nodes, and any
1049  * logic on top of them is represented by a tree of BitmapAndPath and
1050  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
1051  * to represent a regular (or index-only) index scan plan, and as the child
1052  * of a BitmapHeapPath that represents scanning the same index using a
1053  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
1054  * always represent the costs to use it as a regular (or index-only)
1055  * IndexScan. The costs of a BitmapIndexScan can be computed using the
1056  * IndexPath's indextotalcost and indexselectivity.
1057  */
1058 typedef struct BitmapHeapPath
1059 {
1061  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1062 } BitmapHeapPath;
1063 
1064 /*
1065  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1066  * part of the substructure of a BitmapHeapPath. The Path structure is
1067  * a bit more heavyweight than we really need for this, but for simplicity
1068  * we make it a derivative of Path anyway.
1069  */
1070 typedef struct BitmapAndPath
1071 {
1073  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1075 } BitmapAndPath;
1076 
1077 /*
1078  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1079  * part of the substructure of a BitmapHeapPath. The Path structure is
1080  * a bit more heavyweight than we really need for this, but for simplicity
1081  * we make it a derivative of Path anyway.
1082  */
1083 typedef struct BitmapOrPath
1084 {
1086  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1088 } BitmapOrPath;
1089 
1090 /*
1091  * TidPath represents a scan by TID
1092  *
1093  * tidquals is an implicitly OR'ed list of qual expressions of the form
1094  * "CTID = pseudoconstant" or "CTID = ANY(pseudoconstant_array)".
1095  * Note they are bare expressions, not RestrictInfos.
1096  */
1097 typedef struct TidPath
1098 {
1100  List *tidquals; /* qual(s) involving CTID = something */
1101 } TidPath;
1102 
1103 /*
1104  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1105  *
1106  * Note that the subpath comes from a different planning domain; for example
1107  * RTE indexes within it mean something different from those known to the
1108  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1109  * interpret the subpath.
1110  */
1111 typedef struct SubqueryScanPath
1112 {
1114  Path *subpath; /* path representing subquery execution */
1116 
1117 /*
1118  * ForeignPath represents a potential scan of a foreign table, foreign join
1119  * or foreign upper-relation.
1120  *
1121  * fdw_private stores FDW private data about the scan. While fdw_private is
1122  * not actually touched by the core code during normal operations, it's
1123  * generally a good idea to use a representation that can be dumped by
1124  * nodeToString(), so that you can examine the structure during debugging
1125  * with tools like pprint().
1126  */
1127 typedef struct ForeignPath
1128 {
1132 } ForeignPath;
1133 
1134 /*
1135  * CustomPath represents a table scan done by some out-of-core extension.
1136  *
1137  * We provide a set of hooks here - which the provider must take care to set
1138  * up correctly - to allow extensions to supply their own methods of scanning
1139  * a relation. For example, a provider might provide GPU acceleration, a
1140  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1141  *
1142  * CustomPaths can be injected into the planning process for a relation by
1143  * set_rel_pathlist_hook functions.
1144  *
1145  * Core code must avoid assuming that the CustomPath is only as large as
1146  * the structure declared here; providers are allowed to make it the first
1147  * element in a larger structure. (Since the planner never copies Paths,
1148  * this doesn't add any complication.) However, for consistency with the
1149  * FDW case, we provide a "custom_private" field in CustomPath; providers
1150  * may prefer to use that rather than define another struct type.
1151  */
1152 
1153 struct CustomPathMethods;
1154 
1155 typedef struct CustomPath
1156 {
1158  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1159  * nodes/extensible.h */
1160  List *custom_paths; /* list of child Path nodes, if any */
1163 } CustomPath;
1164 
1165 /*
1166  * AppendPath represents an Append plan, ie, successive execution of
1167  * several member plans.
1168  *
1169  * Note: it is possible for "subpaths" to contain only one, or even no,
1170  * elements. These cases are optimized during create_append_plan.
1171  * In particular, an AppendPath with no subpaths is a "dummy" path that
1172  * is created to represent the case that a relation is provably empty.
1173  */
1174 typedef struct AppendPath
1175 {
1177  /* RT indexes of non-leaf tables in a partition tree */
1179  List *subpaths; /* list of component Paths */
1180 } AppendPath;
1181 
1182 #define IS_DUMMY_PATH(p) \
1183  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1184 
1185 /* A relation that's been proven empty will have one path that is dummy */
1186 #define IS_DUMMY_REL(r) \
1187  ((r)->cheapest_total_path != NULL && \
1188  IS_DUMMY_PATH((r)->cheapest_total_path))
1189 
1190 /*
1191  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1192  * results from several member plans to produce similarly-sorted output.
1193  */
1194 typedef struct MergeAppendPath
1195 {
1197  /* RT indexes of non-leaf tables in a partition tree */
1199  List *subpaths; /* list of component Paths */
1200  double limit_tuples; /* hard limit on output tuples, or -1 */
1201 } MergeAppendPath;
1202 
1203 /*
1204  * ResultPath represents use of a Result plan node to compute a variable-free
1205  * targetlist with no underlying tables (a "SELECT expressions" query).
1206  * The query could have a WHERE clause, too, represented by "quals".
1207  *
1208  * Note that quals is a list of bare clauses, not RestrictInfos.
1209  */
1210 typedef struct ResultPath
1211 {
1214 } ResultPath;
1215 
1216 /*
1217  * MaterialPath represents use of a Material plan node, i.e., caching of
1218  * the output of its subpath. This is used when the subpath is expensive
1219  * and needs to be scanned repeatedly, or when we need mark/restore ability
1220  * and the subpath doesn't have it.
1221  */
1222 typedef struct MaterialPath
1223 {
1226 } MaterialPath;
1227 
1228 /*
1229  * UniquePath represents elimination of distinct rows from the output of
1230  * its subpath.
1231  *
1232  * This can represent significantly different plans: either hash-based or
1233  * sort-based implementation, or a no-op if the input path can be proven
1234  * distinct already. The decision is sufficiently localized that it's not
1235  * worth having separate Path node types. (Note: in the no-op case, we could
1236  * eliminate the UniquePath node entirely and just return the subpath; but
1237  * it's convenient to have a UniquePath in the path tree to signal upper-level
1238  * routines that the input is known distinct.)
1239  */
1240 typedef enum
1241 {
1242  UNIQUE_PATH_NOOP, /* input is known unique already */
1243  UNIQUE_PATH_HASH, /* use hashing */
1244  UNIQUE_PATH_SORT /* use sorting */
1246 
1247 typedef struct UniquePath
1248 {
1252  List *in_operators; /* equality operators of the IN clause */
1253  List *uniq_exprs; /* expressions to be made unique */
1254 } UniquePath;
1255 
1256 /*
1257  * GatherPath runs several copies of a plan in parallel and collects the
1258  * results. The parallel leader may also execute the plan, unless the
1259  * single_copy flag is set.
1260  */
1261 typedef struct GatherPath
1262 {
1264  Path *subpath; /* path for each worker */
1265  bool single_copy; /* don't execute path more than once */
1266  int num_workers; /* number of workers sought to help */
1267 } GatherPath;
1268 
1269 /*
1270  * GatherMergePath runs several copies of a plan in parallel and
1271  * collects the results. For gather merge parallel leader always execute the
1272  * plan.
1273  */
1274 typedef struct GatherMergePath
1275 {
1277  Path *subpath; /* path for each worker */
1278  int num_workers; /* number of workers sought to help */
1279 } GatherMergePath;
1280 
1281 
1282 /*
1283  * All join-type paths share these fields.
1284  */
1285 
1286 typedef struct JoinPath
1287 {
1289 
1291 
1292  bool inner_unique; /* each outer tuple provably matches no more
1293  * than one inner tuple */
1294 
1295  Path *outerjoinpath; /* path for the outer side of the join */
1296  Path *innerjoinpath; /* path for the inner side of the join */
1297 
1298  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1299 
1300  /*
1301  * See the notes for RelOptInfo and ParamPathInfo to understand why
1302  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1303  * parent RelOptInfo.
1304  */
1305 } JoinPath;
1306 
1307 /*
1308  * A nested-loop path needs no special fields.
1309  */
1310 
1312 
1313 /*
1314  * A mergejoin path has these fields.
1315  *
1316  * Unlike other path types, a MergePath node doesn't represent just a single
1317  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1318  * node itself, there can be a Sort node for the outer input, a Sort node
1319  * for the inner input, and/or a Material node for the inner input. We could
1320  * represent these nodes by separate path nodes, but considering how many
1321  * different merge paths are investigated during a complex join problem,
1322  * it seems better to avoid unnecessary palloc overhead.
1323  *
1324  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1325  * that will be used in the merge.
1326  *
1327  * Note that the mergeclauses are a subset of the parent relation's
1328  * restriction-clause list. Any join clauses that are not mergejoinable
1329  * appear only in the parent's restrict list, and must be checked by a
1330  * qpqual at execution time.
1331  *
1332  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1333  * (resp. inner path) is already ordered appropriately for the
1334  * mergejoin. If it is not NIL then it is a PathKeys list describing
1335  * the ordering that must be created by an explicit Sort node.
1336  *
1337  * skip_mark_restore is TRUE if the executor need not do mark/restore calls.
1338  * Mark/restore overhead is usually required, but can be skipped if we know
1339  * that the executor need find only one match per outer tuple, and that the
1340  * mergeclauses are sufficient to identify a match. In such cases the
1341  * executor can immediately advance the outer relation after processing a
1342  * match, and therefoere it need never back up the inner relation.
1343  *
1344  * materialize_inner is TRUE if a Material node should be placed atop the
1345  * inner input. This may appear with or without an inner Sort step.
1346  */
1347 
1348 typedef struct MergePath
1349 {
1351  List *path_mergeclauses; /* join clauses to be used for merge */
1352  List *outersortkeys; /* keys for explicit sort, if any */
1353  List *innersortkeys; /* keys for explicit sort, if any */
1354  bool skip_mark_restore; /* can executor skip mark/restore? */
1355  bool materialize_inner; /* add Materialize to inner? */
1356 } MergePath;
1357 
1358 /*
1359  * A hashjoin path has these fields.
1360  *
1361  * The remarks above for mergeclauses apply for hashclauses as well.
1362  *
1363  * Hashjoin does not care what order its inputs appear in, so we have
1364  * no need for sortkeys.
1365  */
1366 
1367 typedef struct HashPath
1368 {
1370  List *path_hashclauses; /* join clauses used for hashing */
1371  int num_batches; /* number of batches expected */
1372 } HashPath;
1373 
1374 /*
1375  * ProjectionPath represents a projection (that is, targetlist computation)
1376  *
1377  * Nominally, this path node represents using a Result plan node to do a
1378  * projection step. However, if the input plan node supports projection,
1379  * we can just modify its output targetlist to do the required calculations
1380  * directly, and not need a Result. In some places in the planner we can just
1381  * jam the desired PathTarget into the input path node (and adjust its cost
1382  * accordingly), so we don't need a ProjectionPath. But in other places
1383  * it's necessary to not modify the input path node, so we need a separate
1384  * ProjectionPath node, which is marked dummy to indicate that we intend to
1385  * assign the work to the input plan node. The estimated cost for the
1386  * ProjectionPath node will account for whether a Result will be used or not.
1387  */
1388 typedef struct ProjectionPath
1389 {
1391  Path *subpath; /* path representing input source */
1392  bool dummypp; /* true if no separate Result is needed */
1393 } ProjectionPath;
1394 
1395 /*
1396  * ProjectSetPath represents evaluation of a targetlist that includes
1397  * set-returning function(s), which will need to be implemented by a
1398  * ProjectSet plan node.
1399  */
1400 typedef struct ProjectSetPath
1401 {
1403  Path *subpath; /* path representing input source */
1404 } ProjectSetPath;
1405 
1406 /*
1407  * SortPath represents an explicit sort step
1408  *
1409  * The sort keys are, by definition, the same as path.pathkeys.
1410  *
1411  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1412  * same as the input's pathtarget.
1413  */
1414 typedef struct SortPath
1415 {
1417  Path *subpath; /* path representing input source */
1418 } SortPath;
1419 
1420 /*
1421  * GroupPath represents grouping (of presorted input)
1422  *
1423  * groupClause represents the columns to be grouped on; the input path
1424  * must be at least that well sorted.
1425  *
1426  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1427  */
1428 typedef struct GroupPath
1429 {
1431  Path *subpath; /* path representing input source */
1432  List *groupClause; /* a list of SortGroupClause's */
1433  List *qual; /* quals (HAVING quals), if any */
1434 } GroupPath;
1435 
1436 /*
1437  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1438  *
1439  * The columns to be compared are the first numkeys columns of the path's
1440  * pathkeys. The input is presumed already sorted that way.
1441  */
1442 typedef struct UpperUniquePath
1443 {
1445  Path *subpath; /* path representing input source */
1446  int numkeys; /* number of pathkey columns to compare */
1447 } UpperUniquePath;
1448 
1449 /*
1450  * AggPath represents generic computation of aggregate functions
1451  *
1452  * This may involve plain grouping (but not grouping sets), using either
1453  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1454  * appropriately presorted.
1455  */
1456 typedef struct AggPath
1457 {
1459  Path *subpath; /* path representing input source */
1460  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1461  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1462  double numGroups; /* estimated number of groups in input */
1463  List *groupClause; /* a list of SortGroupClause's */
1464  List *qual; /* quals (HAVING quals), if any */
1465 } AggPath;
1466 
1467 /*
1468  * Various annotations used for grouping sets in the planner.
1469  */
1470 
1471 typedef struct GroupingSetData
1472 {
1474  List *set; /* grouping set as list of sortgrouprefs */
1475  double numGroups; /* est. number of result groups */
1476 } GroupingSetData;
1477 
1478 typedef struct RollupData
1479 {
1481  List *groupClause; /* applicable subset of parse->groupClause */
1482  List *gsets; /* lists of integer indexes into groupClause */
1483  List *gsets_data; /* list of GroupingSetData */
1484  double numGroups; /* est. number of result groups */
1485  bool hashable; /* can be hashed */
1486  bool is_hashed; /* to be implemented as a hashagg */
1487 } RollupData;
1488 
1489 /*
1490  * GroupingSetsPath represents a GROUPING SETS aggregation
1491  */
1492 
1493 typedef struct GroupingSetsPath
1494 {
1496  Path *subpath; /* path representing input source */
1497  AggStrategy aggstrategy; /* basic strategy */
1498  List *rollups; /* list of RollupData */
1499  List *qual; /* quals (HAVING quals), if any */
1501 
1502 /*
1503  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1504  */
1505 typedef struct MinMaxAggPath
1506 {
1508  List *mmaggregates; /* list of MinMaxAggInfo */
1509  List *quals; /* HAVING quals, if any */
1510 } MinMaxAggPath;
1511 
1512 /*
1513  * WindowAggPath represents generic computation of window functions
1514  *
1515  * Note: winpathkeys is separate from path.pathkeys because the actual sort
1516  * order might be an extension of winpathkeys; but createplan.c needs to
1517  * know exactly how many pathkeys match the window clause.
1518  */
1519 typedef struct WindowAggPath
1520 {
1522  Path *subpath; /* path representing input source */
1523  WindowClause *winclause; /* WindowClause we'll be using */
1524  List *winpathkeys; /* PathKeys for PARTITION keys + ORDER keys */
1525 } WindowAggPath;
1526 
1527 /*
1528  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1529  */
1530 typedef struct SetOpPath
1531 {
1533  Path *subpath; /* path representing input source */
1534  SetOpCmd cmd; /* what to do, see nodes.h */
1535  SetOpStrategy strategy; /* how to do it, see nodes.h */
1536  List *distinctList; /* SortGroupClauses identifying target cols */
1537  AttrNumber flagColIdx; /* where is the flag column, if any */
1538  int firstFlag; /* flag value for first input relation */
1539  double numGroups; /* estimated number of groups in input */
1540 } SetOpPath;
1541 
1542 /*
1543  * RecursiveUnionPath represents a recursive UNION node
1544  */
1545 typedef struct RecursiveUnionPath
1546 {
1548  Path *leftpath; /* paths representing input sources */
1550  List *distinctList; /* SortGroupClauses identifying target cols */
1551  int wtParam; /* ID of Param representing work table */
1552  double numGroups; /* estimated number of groups in input */
1554 
1555 /*
1556  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1557  */
1558 typedef struct LockRowsPath
1559 {
1561  Path *subpath; /* path representing input source */
1562  List *rowMarks; /* a list of PlanRowMark's */
1563  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1564 } LockRowsPath;
1565 
1566 /*
1567  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1568  *
1569  * We represent most things that will be in the ModifyTable plan node
1570  * literally, except we have child Path(s) not Plan(s). But analysis of the
1571  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1572  */
1573 typedef struct ModifyTablePath
1574 {
1576  CmdType operation; /* INSERT, UPDATE, or DELETE */
1577  bool canSetTag; /* do we set the command tag/es_processed? */
1578  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1579  /* RT indexes of non-leaf tables in a partition tree */
1581  List *resultRelations; /* integer list of RT indexes */
1582  List *subpaths; /* Path(s) producing source data */
1583  List *subroots; /* per-target-table PlannerInfos */
1584  List *withCheckOptionLists; /* per-target-table WCO lists */
1585  List *returningLists; /* per-target-table RETURNING tlists */
1586  List *rowMarks; /* PlanRowMarks (non-locking only) */
1587  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1588  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1589 } ModifyTablePath;
1590 
1591 /*
1592  * LimitPath represents applying LIMIT/OFFSET restrictions
1593  */
1594 typedef struct LimitPath
1595 {
1597  Path *subpath; /* path representing input source */
1598  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1599  Node *limitCount; /* COUNT parameter, or NULL if none */
1600 } LimitPath;
1601 
1602 
1603 /*
1604  * Restriction clause info.
1605  *
1606  * We create one of these for each AND sub-clause of a restriction condition
1607  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1608  * ANDed, we can use any one of them or any subset of them to filter out
1609  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1610  * stores data used by the optimizer while choosing the best query plan.
1611  *
1612  * If a restriction clause references a single base relation, it will appear
1613  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1614  *
1615  * If a restriction clause references more than one base rel, it will
1616  * appear in the joininfo list of every RelOptInfo that describes a strict
1617  * subset of the base rels mentioned in the clause. The joininfo lists are
1618  * used to drive join tree building by selecting plausible join candidates.
1619  * The clause cannot actually be applied until we have built a join rel
1620  * containing all the base rels it references, however.
1621  *
1622  * When we construct a join rel that includes all the base rels referenced
1623  * in a multi-relation restriction clause, we place that clause into the
1624  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1625  * right sub-path includes all base rels referenced in the clause. The clause
1626  * will be applied at that join level, and will not propagate any further up
1627  * the join tree. (Note: the "predicate migration" code was once intended to
1628  * push restriction clauses up and down the plan tree based on evaluation
1629  * costs, but it's dead code and is unlikely to be resurrected in the
1630  * foreseeable future.)
1631  *
1632  * Note that in the presence of more than two rels, a multi-rel restriction
1633  * might reach different heights in the join tree depending on the join
1634  * sequence we use. So, these clauses cannot be associated directly with
1635  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1636  *
1637  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1638  * equalities that are not outerjoin-delayed) are handled a bit differently.
1639  * Initially we attach them to the EquivalenceClasses that are derived from
1640  * them. When we construct a scan or join path, we look through all the
1641  * EquivalenceClasses and generate derived RestrictInfos representing the
1642  * minimal set of conditions that need to be checked for this particular scan
1643  * or join to enforce that all members of each EquivalenceClass are in fact
1644  * equal in all rows emitted by the scan or join.
1645  *
1646  * When dealing with outer joins we have to be very careful about pushing qual
1647  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1648  * be evaluated exactly at that join node, unless they are "degenerate"
1649  * conditions that reference only Vars from the nullable side of the join.
1650  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1651  * down below the outer join, if they reference any nullable Vars.
1652  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1653  * pushed down to a lower level than its original syntactic placement in the
1654  * join tree would suggest. If an outer join prevents us from pushing a qual
1655  * down to its "natural" semantic level (the level associated with just the
1656  * base rels used in the qual) then we mark the qual with a "required_relids"
1657  * value including more than just the base rels it actually uses. By
1658  * pretending that the qual references all the rels required to form the outer
1659  * join, we prevent it from being evaluated below the outer join's joinrel.
1660  * When we do form the outer join's joinrel, we still need to distinguish
1661  * those quals that are actually in that join's JOIN/ON condition from those
1662  * that appeared elsewhere in the tree and were pushed down to the join rel
1663  * because they used no other rels. That's what the is_pushed_down flag is
1664  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1665  * rels listed in required_relids. A clause that originally came from WHERE
1666  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1667  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1668  * if we decide that it can be pushed down into the nullable side of the join.
1669  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1670  * (In short, is_pushed_down is only false for non-degenerate outer join
1671  * conditions. Possibly we should rename it to reflect that meaning?)
1672  *
1673  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1674  * if the clause's applicability must be delayed due to any outer joins
1675  * appearing below it (ie, it has to be postponed to some join level higher
1676  * than the set of relations it actually references).
1677  *
1678  * There is also an outer_relids field, which is NULL except for outer join
1679  * clauses; for those, it is the set of relids on the outer side of the
1680  * clause's outer join. (These are rels that the clause cannot be applied to
1681  * in parameterized scans, since pushing it into the join's outer side would
1682  * lead to wrong answers.)
1683  *
1684  * There is also a nullable_relids field, which is the set of rels the clause
1685  * references that can be forced null by some outer join below the clause.
1686  *
1687  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1688  * a clause might reference some nullable rels and yet not be
1689  * outerjoin_delayed because it also references all the other rels of the
1690  * outer join(s). A clause that is not outerjoin_delayed can be enforced
1691  * anywhere it is computable.
1692  *
1693  * To handle security-barrier conditions efficiently, we mark RestrictInfo
1694  * nodes with a security_level field, in which higher values identify clauses
1695  * coming from less-trusted sources. The exact semantics are that a clause
1696  * cannot be evaluated before another clause with a lower security_level value
1697  * unless the first clause is leakproof. As with outer-join clauses, this
1698  * creates a reason for clauses to sometimes need to be evaluated higher in
1699  * the join tree than their contents would suggest; and even at a single plan
1700  * node, this rule constrains the order of application of clauses.
1701  *
1702  * In general, the referenced clause might be arbitrarily complex. The
1703  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
1704  * or hashjoin clauses are limited (e.g., no volatile functions). The code
1705  * for each kind of path is responsible for identifying the restrict clauses
1706  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
1707  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
1708  * of the finished Plan node, where they will be enforced by general-purpose
1709  * qual-expression-evaluation code. (But we are still entitled to count
1710  * their selectivity when estimating the result tuple count, if we
1711  * can guess what it is...)
1712  *
1713  * When the referenced clause is an OR clause, we generate a modified copy
1714  * in which additional RestrictInfo nodes are inserted below the top-level
1715  * OR/AND structure. This is a convenience for OR indexscan processing:
1716  * indexquals taken from either the top level or an OR subclause will have
1717  * associated RestrictInfo nodes.
1718  *
1719  * The can_join flag is set true if the clause looks potentially useful as
1720  * a merge or hash join clause, that is if it is a binary opclause with
1721  * nonoverlapping sets of relids referenced in the left and right sides.
1722  * (Whether the operator is actually merge or hash joinable isn't checked,
1723  * however.)
1724  *
1725  * The pseudoconstant flag is set true if the clause contains no Vars of
1726  * the current query level and no volatile functions. Such a clause can be
1727  * pulled out and used as a one-time qual in a gating Result node. We keep
1728  * pseudoconstant clauses in the same lists as other RestrictInfos so that
1729  * the regular clause-pushing machinery can assign them to the correct join
1730  * level, but they need to be treated specially for cost and selectivity
1731  * estimates. Note that a pseudoconstant clause can never be an indexqual
1732  * or merge or hash join clause, so it's of no interest to large parts of
1733  * the planner.
1734  *
1735  * When join clauses are generated from EquivalenceClasses, there may be
1736  * several equally valid ways to enforce join equivalence, of which we need
1737  * apply only one. We mark clauses of this kind by setting parent_ec to
1738  * point to the generating EquivalenceClass. Multiple clauses with the same
1739  * parent_ec in the same join are redundant.
1740  */
1741 
1742 typedef struct RestrictInfo
1743 {
1745 
1746  Expr *clause; /* the represented clause of WHERE or JOIN */
1747 
1748  bool is_pushed_down; /* TRUE if clause was pushed down in level */
1749 
1750  bool outerjoin_delayed; /* TRUE if delayed by lower outer join */
1751 
1752  bool can_join; /* see comment above */
1753 
1754  bool pseudoconstant; /* see comment above */
1755 
1756  bool leakproof; /* TRUE if known to contain no leaked Vars */
1757 
1758  Index security_level; /* see comment above */
1759 
1760  /* The set of relids (varnos) actually referenced in the clause: */
1762 
1763  /* The set of relids required to evaluate the clause: */
1765 
1766  /* If an outer-join clause, the outer-side relations, else NULL: */
1768 
1769  /* The relids used in the clause that are nullable by lower outer joins: */
1771 
1772  /* These fields are set for any binary opclause: */
1773  Relids left_relids; /* relids in left side of clause */
1774  Relids right_relids; /* relids in right side of clause */
1775 
1776  /* This field is NULL unless clause is an OR clause: */
1777  Expr *orclause; /* modified clause with RestrictInfos */
1778 
1779  /* This field is NULL unless clause is potentially redundant: */
1780  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
1781 
1782  /* cache space for cost and selectivity */
1783  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
1784  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
1785  * semantics; -1 if not yet set; >1 means a
1786  * redundant clause */
1787  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
1788  * not yet set */
1789 
1790  /* valid if clause is mergejoinable, else NIL */
1791  List *mergeopfamilies; /* opfamilies containing clause operator */
1792 
1793  /* cache space for mergeclause processing; NULL if not yet set */
1794  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
1795  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
1796  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
1797  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
1798  List *scansel_cache; /* list of MergeScanSelCache structs */
1799 
1800  /* transient workspace for use while considering a specific join path */
1801  bool outer_is_left; /* T = outer var on left, F = on right */
1802 
1803  /* valid if clause is hashjoinable, else InvalidOid: */
1804  Oid hashjoinoperator; /* copy of clause operator */
1805 
1806  /* cache space for hashclause processing; -1 if not yet set */
1807  Selectivity left_bucketsize; /* avg bucketsize of left side */
1808  Selectivity right_bucketsize; /* avg bucketsize of right side */
1809 } RestrictInfo;
1810 
1811 /*
1812  * Since mergejoinscansel() is a relatively expensive function, and would
1813  * otherwise be invoked many times while planning a large join tree,
1814  * we go out of our way to cache its results. Each mergejoinable
1815  * RestrictInfo carries a list of the specific sort orderings that have
1816  * been considered for use with it, and the resulting selectivities.
1817  */
1818 typedef struct MergeScanSelCache
1819 {
1820  /* Ordering details (cache lookup key) */
1821  Oid opfamily; /* btree opfamily defining the ordering */
1822  Oid collation; /* collation for the ordering */
1823  int strategy; /* sort direction (ASC or DESC) */
1824  bool nulls_first; /* do NULLs come before normal values? */
1825  /* Results */
1826  Selectivity leftstartsel; /* first-join fraction for clause left side */
1827  Selectivity leftendsel; /* last-join fraction for clause left side */
1828  Selectivity rightstartsel; /* first-join fraction for clause right side */
1829  Selectivity rightendsel; /* last-join fraction for clause right side */
1831 
1832 /*
1833  * Placeholder node for an expression to be evaluated below the top level
1834  * of a plan tree. This is used during planning to represent the contained
1835  * expression. At the end of the planning process it is replaced by either
1836  * the contained expression or a Var referring to a lower-level evaluation of
1837  * the contained expression. Typically the evaluation occurs below an outer
1838  * join, and Var references above the outer join might thereby yield NULL
1839  * instead of the expression value.
1840  *
1841  * Although the planner treats this as an expression node type, it is not
1842  * recognized by the parser or executor, so we declare it here rather than
1843  * in primnodes.h.
1844  */
1845 
1846 typedef struct PlaceHolderVar
1847 {
1849  Expr *phexpr; /* the represented expression */
1850  Relids phrels; /* base relids syntactically within expr src */
1851  Index phid; /* ID for PHV (unique within planner run) */
1852  Index phlevelsup; /* > 0 if PHV belongs to outer query */
1853 } PlaceHolderVar;
1854 
1855 /*
1856  * "Special join" info.
1857  *
1858  * One-sided outer joins constrain the order of joining partially but not
1859  * completely. We flatten such joins into the planner's top-level list of
1860  * relations to join, but record information about each outer join in a
1861  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
1862  * join_info_list.
1863  *
1864  * Similarly, semijoins and antijoins created by flattening IN (subselect)
1865  * and EXISTS(subselect) clauses create partial constraints on join order.
1866  * These are likewise recorded in SpecialJoinInfo structs.
1867  *
1868  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
1869  * of planning for them, because this simplifies make_join_rel()'s API.
1870  *
1871  * min_lefthand and min_righthand are the sets of base relids that must be
1872  * available on each side when performing the special join. lhs_strict is
1873  * true if the special join's condition cannot succeed when the LHS variables
1874  * are all NULL (this means that an outer join can commute with upper-level
1875  * outer joins even if it appears in their RHS). We don't bother to set
1876  * lhs_strict for FULL JOINs, however.
1877  *
1878  * It is not valid for either min_lefthand or min_righthand to be empty sets;
1879  * if they were, this would break the logic that enforces join order.
1880  *
1881  * syn_lefthand and syn_righthand are the sets of base relids that are
1882  * syntactically below this special join. (These are needed to help compute
1883  * min_lefthand and min_righthand for higher joins.)
1884  *
1885  * delay_upper_joins is set TRUE if we detect a pushed-down clause that has
1886  * to be evaluated after this join is formed (because it references the RHS).
1887  * Any outer joins that have such a clause and this join in their RHS cannot
1888  * commute with this join, because that would leave noplace to check the
1889  * pushed-down clause. (We don't track this for FULL JOINs, either.)
1890  *
1891  * For a semijoin, we also extract the join operators and their RHS arguments
1892  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
1893  * This is done in support of possibly unique-ifying the RHS, so we don't
1894  * bother unless at least one of semi_can_btree and semi_can_hash can be set
1895  * true. (You might expect that this information would be computed during
1896  * join planning; but it's helpful to have it available during planning of
1897  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
1898  *
1899  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
1900  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
1901  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
1902  *
1903  * For purposes of join selectivity estimation, we create transient
1904  * SpecialJoinInfo structures for regular inner joins; so it is possible
1905  * to have jointype == JOIN_INNER in such a structure, even though this is
1906  * not allowed within join_info_list. We also create transient
1907  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
1908  * cost estimation purposes it is sometimes useful to know the join size under
1909  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
1910  * of course the semi_xxx fields are not set meaningfully within such structs.
1911  */
1912 
1913 typedef struct SpecialJoinInfo
1914 {
1916  Relids min_lefthand; /* base relids in minimum LHS for join */
1917  Relids min_righthand; /* base relids in minimum RHS for join */
1918  Relids syn_lefthand; /* base relids syntactically within LHS */
1919  Relids syn_righthand; /* base relids syntactically within RHS */
1920  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
1921  bool lhs_strict; /* joinclause is strict for some LHS rel */
1922  bool delay_upper_joins; /* can't commute with upper RHS */
1923  /* Remaining fields are set only for JOIN_SEMI jointype: */
1924  bool semi_can_btree; /* true if semi_operators are all btree */
1925  bool semi_can_hash; /* true if semi_operators are all hash */
1926  List *semi_operators; /* OIDs of equality join operators */
1927  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
1928 } SpecialJoinInfo;
1929 
1930 /*
1931  * Append-relation info.
1932  *
1933  * When we expand an inheritable table or a UNION-ALL subselect into an
1934  * "append relation" (essentially, a list of child RTEs), we build an
1935  * AppendRelInfo for each non-partitioned child RTE. The list of
1936  * AppendRelInfos indicates which child RTEs must be included when expanding
1937  * the parent, and each node carries information needed to translate Vars
1938  * referencing the parent into Vars referencing that child.
1939  *
1940  * These structs are kept in the PlannerInfo node's append_rel_list.
1941  * Note that we just throw all the structs into one list, and scan the
1942  * whole list when desiring to expand any one parent. We could have used
1943  * a more complex data structure (eg, one list per parent), but this would
1944  * be harder to update during operations such as pulling up subqueries,
1945  * and not really any easier to scan. Considering that typical queries
1946  * will not have many different append parents, it doesn't seem worthwhile
1947  * to complicate things.
1948  *
1949  * Note: after completion of the planner prep phase, any given RTE is an
1950  * append parent having entries in append_rel_list if and only if its
1951  * "inh" flag is set. We clear "inh" for plain tables that turn out not
1952  * to have inheritance children, and (in an abuse of the original meaning
1953  * of the flag) we set "inh" for subquery RTEs that turn out to be
1954  * flattenable UNION ALL queries. This lets us avoid useless searches
1955  * of append_rel_list.
1956  *
1957  * Note: the data structure assumes that append-rel members are single
1958  * baserels. This is OK for inheritance, but it prevents us from pulling
1959  * up a UNION ALL member subquery if it contains a join. While that could
1960  * be fixed with a more complex data structure, at present there's not much
1961  * point because no improvement in the plan could result.
1962  */
1963 
1964 typedef struct AppendRelInfo
1965 {
1967 
1968  /*
1969  * These fields uniquely identify this append relationship. There can be
1970  * (in fact, always should be) multiple AppendRelInfos for the same
1971  * parent_relid, but never more than one per child_relid, since a given
1972  * RTE cannot be a child of more than one append parent.
1973  */
1974  Index parent_relid; /* RT index of append parent rel */
1975  Index child_relid; /* RT index of append child rel */
1976 
1977  /*
1978  * For an inheritance appendrel, the parent and child are both regular
1979  * relations, and we store their rowtype OIDs here for use in translating
1980  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
1981  * both subqueries with no named rowtype, and we store InvalidOid here.
1982  */
1983  Oid parent_reltype; /* OID of parent's composite type */
1984  Oid child_reltype; /* OID of child's composite type */
1985 
1986  /*
1987  * The N'th element of this list is a Var or expression representing the
1988  * child column corresponding to the N'th column of the parent. This is
1989  * used to translate Vars referencing the parent rel into references to
1990  * the child. A list element is NULL if it corresponds to a dropped
1991  * column of the parent (this is only possible for inheritance cases, not
1992  * UNION ALL). The list elements are always simple Vars for inheritance
1993  * cases, but can be arbitrary expressions in UNION ALL cases.
1994  *
1995  * Notice we only store entries for user columns (attno > 0). Whole-row
1996  * Vars are special-cased, and system columns (attno < 0) need no special
1997  * translation since their attnos are the same for all tables.
1998  *
1999  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
2000  * when copying into a subquery.
2001  */
2002  List *translated_vars; /* Expressions in the child's Vars */
2003 
2004  /*
2005  * We store the parent table's OID here for inheritance, or InvalidOid for
2006  * UNION ALL. This is only needed to help in generating error messages if
2007  * an attempt is made to reference a dropped parent column.
2008  */
2009  Oid parent_reloid; /* OID of parent relation */
2010 } AppendRelInfo;
2011 
2012 /*
2013  * For a partitioned table, this maps its RT index to the list of RT indexes
2014  * of the partitioned child tables in the partition tree. We need to
2015  * separately store this information, because we do not create AppendRelInfos
2016  * for the partitioned child tables of a parent table, since AppendRelInfos
2017  * contain information that is unnecessary for the partitioned child tables.
2018  * The child_rels list must contain at least one element, because the parent
2019  * partitioned table is itself counted as a child.
2020  *
2021  * These structs are kept in the PlannerInfo node's pcinfo_list.
2022  */
2024 {
2026 
2030 
2031 /*
2032  * For each distinct placeholder expression generated during planning, we
2033  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
2034  * This stores info that is needed centrally rather than in each copy of the
2035  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
2036  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
2037  * not just within a query level --- this is so that we need not reassign ID's
2038  * when pulling a subquery into its parent.
2039  *
2040  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
2041  * then allow it to bubble up like a Var until the ph_needed join level.
2042  * ph_needed has the same definition as attr_needed for a regular Var.
2043  *
2044  * The PlaceHolderVar's expression might contain LATERAL references to vars
2045  * coming from outside its syntactic scope. If so, those rels are *not*
2046  * included in ph_eval_at, but they are recorded in ph_lateral.
2047  *
2048  * Notice that when ph_eval_at is a join rather than a single baserel, the
2049  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
2050  * has to be formed below any outer joins that should null the PlaceHolderVar.
2051  *
2052  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
2053  * is actually referenced in the plan tree, so that unreferenced placeholders
2054  * don't result in unnecessary constraints on join order.
2055  */
2056 
2057 typedef struct PlaceHolderInfo
2058 {
2060 
2061  Index phid; /* ID for PH (unique within planner run) */
2062  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
2063  Relids ph_eval_at; /* lowest level we can evaluate value at */
2064  Relids ph_lateral; /* relids of contained lateral refs, if any */
2065  Relids ph_needed; /* highest level the value is needed at */
2066  int32 ph_width; /* estimated attribute width */
2067 } PlaceHolderInfo;
2068 
2069 /*
2070  * This struct describes one potentially index-optimizable MIN/MAX aggregate
2071  * function. MinMaxAggPath contains a list of these, and if we accept that
2072  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
2073  */
2074 typedef struct MinMaxAggInfo
2075 {
2077 
2078  Oid aggfnoid; /* pg_proc Oid of the aggregate */
2079  Oid aggsortop; /* Oid of its sort operator */
2080  Expr *target; /* expression we are aggregating on */
2081  PlannerInfo *subroot; /* modified "root" for planning the subquery */
2082  Path *path; /* access path for subquery */
2083  Cost pathcost; /* estimated cost to fetch first row */
2084  Param *param; /* param for subplan's output */
2085 } MinMaxAggInfo;
2086 
2087 /*
2088  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
2089  * node to another. They can be used to pass values down into subqueries (for
2090  * outer references in subqueries), or up out of subqueries (for the results
2091  * of a subplan), or from a NestLoop plan node into its inner relation (when
2092  * the inner scan is parameterized with values from the outer relation).
2093  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
2094  * the PARAM_EXEC Params it generates.
2095  *
2096  * Outer references are managed via root->plan_params, which is a list of
2097  * PlannerParamItems. While planning a subquery, each parent query level's
2098  * plan_params contains the values required from it by the current subquery.
2099  * During create_plan(), we use plan_params to track values that must be
2100  * passed from outer to inner sides of NestLoop plan nodes.
2101  *
2102  * The item a PlannerParamItem represents can be one of three kinds:
2103  *
2104  * A Var: the slot represents a variable of this level that must be passed
2105  * down because subqueries have outer references to it, or must be passed
2106  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
2107  * will always be zero.
2108  *
2109  * A PlaceHolderVar: this works much like the Var case, except that the
2110  * entry is a PlaceHolderVar node with a contained expression. The PHV
2111  * will have phlevelsup = 0, and the contained expression is adjusted
2112  * to match in level.
2113  *
2114  * An Aggref (with an expression tree representing its argument): the slot
2115  * represents an aggregate expression that is an outer reference for some
2116  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
2117  * is adjusted to match in level.
2118  *
2119  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
2120  * them into one slot, but we do not bother to do that for Aggrefs.
2121  * The scope of duplicate-elimination only extends across the set of
2122  * parameters passed from one query level into a single subquery, or for
2123  * nestloop parameters across the set of nestloop parameters used in a single
2124  * query level. So there is no possibility of a PARAM_EXEC slot being used
2125  * for conflicting purposes.
2126  *
2127  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2128  * from subplans (values that are setParam items for those subplans). These
2129  * IDs need not be tracked via PlannerParamItems, since we do not need any
2130  * duplicate-elimination nor later processing of the represented expressions.
2131  * Instead, we just record the assignment of the slot number by incrementing
2132  * root->glob->nParamExec.
2133  */
2134 typedef struct PlannerParamItem
2135 {
2137 
2138  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2139  int paramId; /* its assigned PARAM_EXEC slot number */
2141 
2142 /*
2143  * When making cost estimates for a SEMI/ANTI/inner_unique join, there are
2144  * some correction factors that are needed in both nestloop and hash joins
2145  * to account for the fact that the executor can stop scanning inner rows
2146  * as soon as it finds a match to the current outer row. These numbers
2147  * depend only on the selected outer and inner join relations, not on the
2148  * particular paths used for them, so it's worthwhile to calculate them
2149  * just once per relation pair not once per considered path. This struct
2150  * is filled by compute_semi_anti_join_factors and must be passed along
2151  * to the join cost estimation functions.
2152  *
2153  * outer_match_frac is the fraction of the outer tuples that are
2154  * expected to have at least one match.
2155  * match_count is the average number of matches expected for
2156  * outer tuples that have at least one match.
2157  */
2158 typedef struct SemiAntiJoinFactors
2159 {
2163 
2164 /*
2165  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2166  *
2167  * restrictlist contains all of the RestrictInfo nodes for restriction
2168  * clauses that apply to this join
2169  * mergeclause_list is a list of RestrictInfo nodes for available
2170  * mergejoin clauses in this join
2171  * inner_unique is true if each outer tuple provably matches no more
2172  * than one inner tuple
2173  * sjinfo is extra info about special joins for selectivity estimation
2174  * semifactors is as shown above (only valid for SEMI/ANTI/inner_unique joins)
2175  * param_source_rels are OK targets for parameterization of result paths
2176  */
2177 typedef struct JoinPathExtraData
2178 {
2186 
2187 /*
2188  * For speed reasons, cost estimation for join paths is performed in two
2189  * phases: the first phase tries to quickly derive a lower bound for the
2190  * join cost, and then we check if that's sufficient to reject the path.
2191  * If not, we come back for a more refined cost estimate. The first phase
2192  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2193  * and possibly additional intermediate values. The second phase takes
2194  * these values as inputs to avoid repeating work.
2195  *
2196  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2197  * so seems best to put it here.)
2198  */
2199 typedef struct JoinCostWorkspace
2200 {
2201  /* Preliminary cost estimates --- must not be larger than final ones! */
2202  Cost startup_cost; /* cost expended before fetching any tuples */
2203  Cost total_cost; /* total cost (assuming all tuples fetched) */
2204 
2205  /* Fields below here should be treated as private to costsize.c */
2206  Cost run_cost; /* non-startup cost components */
2207 
2208  /* private for cost_nestloop code */
2209  Cost inner_run_cost; /* also used by cost_mergejoin code */
2211 
2212  /* private for cost_mergejoin code */
2213  double outer_rows;
2214  double inner_rows;
2217 
2218  /* private for cost_hashjoin code */
2222 
2223 #endif /* RELATION_H */
QualCost eval_cost
Definition: relation.h:1783
bool has_eclass_joins
Definition: relation.h:590
struct ModifyTablePath ModifyTablePath
struct Path * cheapest_unique_path
Definition: relation.h:543
NodeTag type
Definition: relation.h:1480
List * indexorderbycols
Definition: relation.h:1035
char maxParallelHazard
Definition: relation.h:132
List * group_pathkeys
Definition: relation.h:263
struct MinMaxAggPath MinMaxAggPath
List * rowMarks
Definition: relation.h:255
struct ForeignKeyOptInfo ForeignKeyOptInfo
Relids ph_needed
Definition: relation.h:2065
List * qual
Definition: relation.h:1433
bool semi_can_btree
Definition: relation.h:1924
Selectivity leftendsel
Definition: relation.h:1827
List * path_mergeclauses
Definition: relation.h:1351
int join_cur_level
Definition: relation.h:225
List * outersortkeys
Definition: relation.h:1352
List * distinctList
Definition: relation.h:1536
List * unique_for_rels
Definition: relation.h:579
JoinPath jpath
Definition: relation.h:1369
struct GroupingSetData GroupingSetData
PathTarget * pathtarget
Definition: relation.h:953
Query * parse
Definition: relation.h:154
List * statlist
Definition: relation.h:562
List * returningLists
Definition: relation.h:1585
struct PathTarget PathTarget
Index security_level
Definition: relation.h:1758
OnConflictExpr * onconflict
Definition: relation.h:1587
List * groupClause
Definition: relation.h:1481
bool predOK
Definition: relation.h:662
Node * limitOffset
Definition: relation.h:1598
Path * subpath
Definition: relation.h:1445
struct PlaceHolderInfo PlaceHolderInfo
Path path
Definition: relation.h:1029
NodeTag type
Definition: relation.h:1966
Path * subpath
Definition: relation.h:1417
Relids ph_eval_at
Definition: relation.h:2063
List * plan_params
Definition: relation.h:168
PlaceHolderVar * ph_var
Definition: relation.h:2062
IndexOptInfo * indexinfo
Definition: relation.h:1030
SemiAntiJoinFactors semifactors
Definition: relation.h:2183
Index nominalRelation
Definition: relation.h:1578
Oid * indexcollations
Definition: relation.h:642
bool hasJoinRTEs
Definition: relation.h:298
Path * fdw_outerpath
Definition: relation.h:1130
RelOptKind reloptkind
Definition: relation.h:521
Relids * attr_needed
Definition: relation.h:557
List * custom_paths
Definition: relation.h:1160
List * query_pathkeys
Definition: relation.h:261
int num_batches
Definition: relation.h:1371
List * join_info_list
Definition: relation.h:249
Relids required_relids
Definition: relation.h:1764
SetOpStrategy strategy
Definition: relation.h:1535
Relids min_righthand
Definition: relation.h:1917
AggStrategy aggstrategy
Definition: relation.h:1460
bool materialize_inner
Definition: relation.h:1355
void * join_search_private
Definition: relation.h:315
Relids curOuterRels
Definition: relation.h:311
NodeTag type
Definition: relation.h:718
List * qual
Definition: relation.h:1464
bool leakproof
Definition: relation.h:1756
Index ec_min_security
Definition: relation.h:782
Expr * orclause
Definition: relation.h:1777
Selectivity outer_match_frac
Definition: relation.h:2160
Path * innerjoinpath
Definition: relation.h:1296
struct BitmapOrPath BitmapOrPath
List * indextlist
Definition: relation.h:655
struct AppendPath AppendPath
struct Path * cheapest_startup_path
Definition: relation.h:541
struct LockRowsPath LockRowsPath
Oid userid
Definition: relation.h:572
struct IndexPath IndexPath
struct CustomPath CustomPath
Relids em_nullable_relids
Definition: relation.h:822
int lastPlanNodeId
Definition: relation.h:122
double tuples
Definition: relation.h:564
Oid reltablespace
Definition: relation.h:553
Path * subpath
Definition: relation.h:1533
List * baserestrictinfo
Definition: relation.h:583
NodeTag type
Definition: relation.h:948
List * ec_derives
Definition: relation.h:774
struct UniquePath UniquePath
List * rowMarks
Definition: relation.h:1586
NodeTag type
Definition: relation.h:1915
struct SpecialJoinInfo SpecialJoinInfo
Relids clause_relids
Definition: relation.h:1761
Param * param
Definition: relation.h:2084
struct JoinPathExtraData JoinPathExtraData
int parallel_workers
Definition: relation.h:959
bool pseudoconstant
Definition: relation.h:1754
RelOptKind
Definition: relation.h:491
bool consider_param_startup
Definition: relation.h:531
struct PlannerInfo PlannerInfo
List * resultRelations
Definition: relation.h:108
struct RollupData RollupData
bool is_hashed
Definition: relation.h:1486
ParamPathInfo * param_info
Definition: relation.h:955
struct EquivalenceMember EquivalenceMember
Index ec_sortref
Definition: relation.h:781
Definition: nodes.h:509
Oid * sortopfamily
Definition: relation.h:645
struct SubqueryScanPath SubqueryScanPath
List * partial_pathlist
Definition: relation.h:540
Oid reltablespace
Definition: relation.h:631
Relids left_relids
Definition: relation.h:1773
List * join_rel_list
Definition: relation.h:214
bool ec_below_outer_join
Definition: relation.h:779
uint32 flags
Definition: relation.h:1158
bool hasNonSerial
Definition: relation.h:61
uint32 BlockNumber
Definition: block.h:31
EquivalenceClass * right_ec
Definition: relation.h:1795
List * cheapest_parameterized_paths
Definition: relation.h:544
List * minmax_aggs
Definition: relation.h:284
bool single_copy
Definition: relation.h:1265
bool hypothetical
Definition: relation.h:665
Index baserestrict_min_security
Definition: relation.h:586
UniquePathMethod umethod
Definition: relation.h:1251
struct WindowAggPath WindowAggPath
Path * subpath
Definition: relation.h:1225
List * indexclauses
Definition: relation.h:1031
NodeTag type
Definition: relation.h:519
double Selectivity
Definition: nodes.h:638
NodeTag type
Definition: relation.h:2059
Index ec_max_security
Definition: relation.h:783
bool hasNonPartial
Definition: relation.h:60
bool useridiscurrent
Definition: relation.h:573
AggSplit aggsplit
Definition: relation.h:1461
bool immediate
Definition: relation.h:664
QualCost transCost
Definition: relation.h:62
List * partitioned_rels
Definition: relation.h:1198
struct ProjectSetPath ProjectSetPath
Selectivity bitmapselectivity
Definition: relation.h:1074
double tuples
Definition: relation.h:636
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: relation.h:1509
UpperRelationKind
Definition: relation.h:71
struct ResultPath ResultPath
AttrNumber * grouping_map
Definition: relation.h:283
List * fkey_list
Definition: relation.h:259
int tree_height
Definition: relation.h:637
struct GatherMergePath GatherMergePath
bool hasRecursion
Definition: relation.h:304
double numGroups
Definition: relation.h:1462
double numGroups
Definition: relation.h:1539
List * mergeopfamilies
Definition: relation.h:1791
List * translated_vars
Definition: relation.h:2002
SetOpStrategy
Definition: nodes.h:786
Cost inner_rescan_run_cost
Definition: relation.h:2210
Oid parent_reltype
Definition: relation.h:1983
Relids syn_lefthand
Definition: relation.h:1918
List * rowMarks
Definition: relation.h:1562
int pk_strategy
Definition: relation.h:851
List * winpathkeys
Definition: relation.h:1524
struct PlaceHolderVar PlaceHolderVar
double numGroups
Definition: relation.h:1484
Cost startup
Definition: relation.h:45
double allvisfrac
Definition: relation.h:565
Relids outer_relids
Definition: relation.h:1767
signed int int32
Definition: c.h:256
List * bitmapquals
Definition: relation.h:1073
Selectivity norm_selec
Definition: relation.h:1784
Path path
Definition: relation.h:1176
List * custom_private
Definition: relation.h:1161
JoinType
Definition: nodes.h:672
struct PlannerGlobal PlannerGlobal
WindowClause * winclause
Definition: relation.h:1523
struct RelOptInfo ** simple_rel_array
Definition: relation.h:178
List * bitmapquals
Definition: relation.h:1086
int num_workers
Definition: relation.h:1266
List * multiexpr_params
Definition: relation.h:231
bool unique
Definition: relation.h:663
BlockNumber pages
Definition: relation.h:635
NodeTag pathtype
Definition: relation.h:950
Relids syn_righthand
Definition: relation.h:1919
List * subpaths
Definition: relation.h:1179
PlannerInfo * subroot
Definition: relation.h:566
NodeTag type
Definition: relation.h:847
SetOpCmd cmd
Definition: relation.h:1534
bool dependsOnRole
Definition: relation.h:126
struct AggPath AggPath
NodeTag type
Definition: relation.h:1473
bool consider_startup
Definition: relation.h:530
Definition: dynahash.c:193
struct MaterialPath MaterialPath
Relids lateral_relids
Definition: relation.h:549
Cost per_tuple
Definition: relation.h:46
const struct CustomPathMethods * methods
Definition: relation.h:1162
List * indexquals
Definition: relation.h:1032
int wt_param_id
Definition: relation.h:307
double tuple_fraction
Definition: relation.h:290
Path * subpath
Definition: relation.h:1522
bool skip_mark_restore
Definition: relation.h:1354
RelOptInfo * rel
Definition: relation.h:632
bool amoptionalkey
Definition: relation.h:669
SpecialJoinInfo * sjinfo
Definition: relation.h:2182
bool parallelModeNeeded
Definition: relation.h:130
Path path
Definition: relation.h:1212
struct AppendRelInfo AppendRelInfo
Relids phrels
Definition: relation.h:1850
Relids all_baserels
Definition: relation.h:195
bool pk_nulls_first
Definition: relation.h:852
Path * path
Definition: relation.h:2082
bool hasDeletedRTEs
Definition: relation.h:300
Expr * phexpr
Definition: relation.h:1849
Relids param_source_rels
Definition: relation.h:2184
NodeTag type
Definition: relation.h:909
double limit_tuples
Definition: relation.h:291
EquivalenceMember * left_em
Definition: relation.h:1796
Cost indextotalcost
Definition: relation.h:1037
Cost startup_cost
Definition: relation.h:964
List * semi_rhs_exprs
Definition: relation.h:1927
NodeTag type
Definition: relation.h:881
Oid conpfeqop[INDEX_MAX_KEYS]
Definition: relation.h:697
bool semi_can_hash
Definition: relation.h:1925
bool hasLateralRTEs
Definition: relation.h:299
Path * subpath
Definition: relation.h:1597
struct PlannerParamItem PlannerParamItem
List * joinrestrictinfo
Definition: relation.h:1298
bool parallelModeOK
Definition: relation.h:128
EquivalenceClass * parent_ec
Definition: relation.h:1780
bool can_join
Definition: relation.h:1752
RTEKind
Definition: parsenodes.h:913
List * subroots
Definition: relation.h:1583
Bitmapset * rewindPlanIDs
Definition: relation.h:102
RelOptInfo * parent
Definition: relation.h:952
List * uniq_exprs
Definition: relation.h:1253
Path * bitmapqual
Definition: relation.h:1061
bool outerjoin_delayed
Definition: relation.h:1750
Path path
Definition: relation.h:1430
List * ec_sources
Definition: relation.h:773
struct Path * cheapest_total_path
Definition: relation.h:542
Selectivity rightstartsel
Definition: relation.h:1828
List * curOuterParams
Definition: relation.h:312
struct SetOpPath SetOpPath
struct IndexOptInfo IndexOptInfo
Selectivity indexselectivity
Definition: relation.h:1038
List * subplans
Definition: relation.h:98
bool amcanorderbyop
Definition: relation.h:668
List * joininfo
Definition: relation.h:588
struct GroupPath GroupPath
Relids ec_relids
Definition: relation.h:775
PlannerGlobal * glob
Definition: relation.h:156
bool outer_is_left
Definition: relation.h:1801
struct FdwRoutine * fdwroutine
Definition: relation.h:575
List * left_join_clauses
Definition: relation.h:238
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: relation.h:246
struct GroupingSetsPath GroupingSetsPath
List * subpaths
Definition: relation.h:1582
List * groupClause
Definition: relation.h:1463
Index * sortgrouprefs
Definition: relation.h:883
List * mergeclause_list
Definition: relation.h:2180
unsigned int uint32
Definition: c.h:268
AttrNumber flagColIdx
Definition: relation.h:1537
Relids relids
Definition: relation.h:524
AggStrategy aggstrategy
Definition: relation.h:1497
Selectivity outer_selec
Definition: relation.h:1787
Path * subpath
Definition: relation.h:1264
struct TidPath TidPath
double total_table_pages
Definition: relation.h:288
struct LimitPath LimitPath
Selectivity bitmapselectivity
Definition: relation.h:1087
struct RecursiveUnionPath RecursiveUnionPath
RelOptInfo * rel
Definition: relation.h:721
int simple_rel_array_size
Definition: relation.h:179
int ncolumns
Definition: relation.h:640
bool amhasgetbitmap
Definition: relation.h:673
List * canon_pathkeys
Definition: relation.h:236
List * non_unique_for_rels
Definition: relation.h:580
List * ppilist
Definition: relation.h:539
Path path
Definition: relation.h:1157
Index relid
Definition: relation.h:552
Bitmapset * Relids
Definition: relation.h:28
List * sort_pathkeys
Definition: relation.h:266
RangeTblEntry ** simple_rte_array
Definition: relation.h:187
struct PlannerInfo * parent_root
Definition: relation.h:160
EquivalenceMember * right_em
Definition: relation.h:1797
Relids lateral_referencers
Definition: relation.h:560
Expr * clause
Definition: relation.h:1746
int numOrderedAggs
Definition: relation.h:59
Path * subpath
Definition: relation.h:1561
struct EquivalenceClass * eclass[INDEX_MAX_KEYS]
Definition: relation.h:704
Oid serverid
Definition: relation.h:571
List * ec_opfamilies
Definition: relation.h:770
List * exprs
Definition: relation.h:882
struct ParamPathInfo ParamPathInfo
struct Path Path
List * window_pathkeys
Definition: relation.h:264
List * indrestrictinfo
Definition: relation.h:657
Relids direct_lateral_relids
Definition: relation.h:548
Path * outerjoinpath
Definition: relation.h:1295
List * invalItems
Definition: relation.h:114
NodeTag type
Definition: relation.h:152
struct MinMaxAggInfo MinMaxAggInfo
Relids nullable_relids
Definition: relation.h:1770
bool delay_upper_joins
Definition: relation.h:1922
struct QualCost QualCost
List * indexorderbys
Definition: relation.h:1034
AttrNumber conkey[INDEX_MAX_KEYS]
Definition: relation.h:695
int rel_parallel_workers
Definition: relation.h:568
List * groupClause
Definition: relation.h:1432
List * append_rel_list
Definition: relation.h:251
Index lastPHId
Definition: relation.h:118
List * cte_plan_ids
Definition: relation.h:229
List * mmaggregates
Definition: relation.h:1508
Relids ph_lateral
Definition: relation.h:2064
List * partitioned_rels
Definition: relation.h:1580
Relids em_relids
Definition: relation.h:821
List * tidquals
Definition: relation.h:1100
List * restrictlist
Definition: relation.h:2179
Path * subpath
Definition: relation.h:1431
unsigned int Index
Definition: c.h:365
struct ForeignPath ForeignPath
RTEKind rtekind
Definition: relation.h:554
List * indexlist
Definition: relation.h:561
List * init_plans
Definition: relation.h:227
List * in_operators
Definition: relation.h:1252
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct MergeScanSelCache MergeScanSelCache
struct RestrictInfo RestrictInfo
double rows
Definition: relation.h:527
bool hasPseudoConstantQuals
Definition: relation.h:302
bool amhasgettuple
Definition: relation.h:672
Cost finalCost
Definition: relation.h:63
List * distinct_pathkeys
Definition: relation.h:265
bool is_pushed_down
Definition: relation.h:1748
void * fdw_private
Definition: relation.h:576
Cost total_cost
Definition: relation.h:965
NodeTag type
Definition: relation.h:628
Selectivity left_bucketsize
Definition: relation.h:1807
int firstFlag
Definition: relation.h:1538
double outer_skip_rows
Definition: relation.h:2215
List * pathkeys
Definition: relation.h:967
struct GatherPath GatherPath
List * nonleafResultRelations
Definition: relation.h:110
Relids right_relids
Definition: relation.h:1774
BlockNumber pages
Definition: relation.h:563
Path path
Definition: relation.h:1288
ParamListInfo boundParams
Definition: relation.h:96
struct AggClauseCosts AggClauseCosts
Expr * target
Definition: relation.h:2080
List * pcinfo_list
Definition: relation.h:253
List * eq_classes
Definition: relation.h:234
List ** join_rel_level
Definition: relation.h:224
NodeTag type
Definition: relation.h:94
JoinPath NestPath
Definition: relation.h:1311
Path * subpath
Definition: relation.h:1403
double rows
Definition: relation.h:963
bool parallel_safe
Definition: relation.h:958
List * lateral_vars
Definition: relation.h:559
bool hasInheritedTarget
Definition: relation.h:296
List * quals
Definition: relation.h:1213
JoinType jointype
Definition: relation.h:1920
EquivalenceClass * pk_eclass
Definition: relation.h:849
Bitmapset * outer_params
Definition: relation.h:169
List * ppi_clauses
Definition: relation.h:913
struct Path * non_recursive_path
Definition: relation.h:308
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:356
Oid hashjoinoperator
Definition: relation.h:1804
NodeTag type
Definition: relation.h:1744
QualCost cost
Definition: relation.h:884
AggSplit
Definition: nodes.h:756
bool ec_has_volatile
Definition: relation.h:778
List * relationOids
Definition: relation.h:112
struct HashPath HashPath
List * subroots
Definition: relation.h:100
bool amsearcharray
Definition: relation.h:670
struct HTAB * join_rel_hash
Definition: relation.h:215
CostSelector
Definition: relation.h:34
struct JoinPath JoinPath
bool inner_unique
Definition: relation.h:1292
Index qual_security_level
Definition: relation.h:293
bool consider_parallel
Definition: relation.h:532
List * innersortkeys
Definition: relation.h:1353
Path * subpath
Definition: relation.h:1459
Oid * opcintype
Definition: relation.h:644
struct EquivalenceClass EquivalenceClass
List * partitioned_rels
Definition: relation.h:1178
Index query_level
Definition: relation.h:158
Oid pk_opfamily
Definition: relation.h:850
struct JoinCostWorkspace JoinCostWorkspace
Path * subpath
Definition: relation.h:1277
struct SortPath SortPath
double ppi_rows
Definition: relation.h:912
Path path
Definition: relation.h:1596
Path path
Definition: relation.h:1099
struct PartitionedChildRelInfo PartitionedChildRelInfo
Oid child_reltype
Definition: relation.h:1984
Oid * opfamily
Definition: relation.h:643
List * withCheckOptionLists
Definition: relation.h:1584
List * indexqualcols
Definition: relation.h:1033
List * finalrtable
Definition: relation.h:104
int width
Definition: relation.h:885
AggStrategy
Definition: nodes.h:734
Bitmapset * keys
Definition: relation.h:723
Index phlevelsup
Definition: relation.h:1852
Index lastRowMarkId
Definition: relation.h:120
AttrNumber max_attr
Definition: relation.h:556
Selectivity match_count
Definition: relation.h:2161
Selectivity right_bucketsize
Definition: relation.h:1808
EquivalenceClass * left_ec
Definition: relation.h:1794
Relids nullable_baserels
Definition: relation.h:203
struct MergeAppendPath MergeAppendPath
List * fdw_private
Definition: relation.h:1131
SetOpCmd
Definition: nodes.h:778
JoinType jointype
Definition: relation.h:1290
List * semi_operators
Definition: relation.h:1926
ScanDirection indexscandir
Definition: relation.h:1036
CmdType operation
Definition: relation.h:1576
List * placeholder_list
Definition: relation.h:257
List * resultRelations
Definition: relation.h:1581
int nParamExec
Definition: relation.h:116
struct StatisticExtInfo StatisticExtInfo
Size transitionSpace
Definition: relation.h:64
double numGroups
Definition: relation.h:1475
bool hashable
Definition: relation.h:1485
struct BitmapHeapPath BitmapHeapPath
bool hasHavingQual
Definition: relation.h:301
struct PathKey PathKey
JoinPath jpath
Definition: relation.h:1350
NodeTag type
Definition: relation.h:768
bool parallel_aware
Definition: relation.h:957
int * indexkeys
Definition: relation.h:641
List * path_hashclauses
Definition: relation.h:1370
struct ProjectionPath ProjectionPath
UniquePathMethod
Definition: relation.h:1240
struct UpperUniquePath UpperUniquePath
List * initial_rels
Definition: relation.h:268
List * pathlist
Definition: relation.h:538
List * subpaths
Definition: relation.h:1199
Relids ppi_req_outer
Definition: relation.h:911
MemoryContext planner_cxt
Definition: relation.h:286
struct MergePath MergePath
List * right_join_clauses
Definition: relation.h:242
Oid indexoid
Definition: relation.h:630
Index child_relid
Definition: relation.h:1975
bool * canreturn
Definition: relation.h:648
bool amsearchnulls
Definition: relation.h:671
Oid parent_reloid
Definition: relation.h:2009
void(* amcostestimate)()
Definition: relation.h:676
bool * nulls_first
Definition: relation.h:647
Path * subpath
Definition: relation.h:1391
Path path
Definition: relation.h:1263
Index parent_relid
Definition: relation.h:1974
bool * reverse_sort
Definition: relation.h:646
double inner_skip_rows
Definition: relation.h:2216
List * processed_tlist
Definition: relation.h:280
List * indpred
Definition: relation.h:653
int32 * attr_widths
Definition: relation.h:558
Node * limitCount
Definition: relation.h:1599
List * finalrowmarks
Definition: relation.h:106
Definition: pg_list.h:45
AttrNumber confkey[INDEX_MAX_KEYS]
Definition: relation.h:696
Path path
Definition: relation.h:1416
struct PathTarget * reltarget
Definition: relation.h:535
Relids min_lefthand
Definition: relation.h:1916
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: relation.h:585
List * rinfos[INDEX_MAX_KEYS]
Definition: relation.h:706
List * subplan_params
Definition: relation.h:567
Path path
Definition: relation.h:1532
NodeTag type
Definition: relation.h:2076
Path path
Definition: relation.h:1249
CmdType
Definition: nodes.h:648
List * gsets_data
Definition: relation.h:1483
Path path
Definition: relation.h:1458
struct RelOptInfo RelOptInfo
Definition: relation.h:946
double limit_tuples
Definition: relation.h:1200
struct EquivalenceClass * ec_merged
Definition: relation.h:784
Selectivity rightendsel
Definition: relation.h:1829
bool amcanparallel
Definition: relation.h:674
double Cost
Definition: nodes.h:639
List * scansel_cache
Definition: relation.h:1798
Selectivity leftstartsel
Definition: relation.h:1826
List * ec_members
Definition: relation.h:772
List * indexprs
Definition: relation.h:652
Relids top_parent_relids
Definition: relation.h:593
bool transientPlan
Definition: relation.h:124
List * gsets
Definition: relation.h:1482
struct PathTarget * upper_targets[UPPERREL_FINAL+1]
Definition: relation.h:274
Path * subpath
Definition: relation.h:1250
PlannerInfo * subroot
Definition: relation.h:2081
struct BitmapAndPath BitmapAndPath
List * upper_rels[UPPERREL_FINAL+1]
Definition: relation.h:271
AttrNumber min_attr
Definition: relation.h:555