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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 *relationOids; /* OIDs of relations the plan depends on */
111 
112  List *invalItems; /* other dependencies, as PlanInvalItems */
113 
114  int nParamExec; /* number of PARAM_EXEC Params used */
115 
116  Index lastPHId; /* highest PlaceHolderVar ID assigned */
117 
118  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
119 
120  int lastPlanNodeId; /* highest plan node ID assigned */
121 
122  bool transientPlan; /* redo plan when TransactionXmin changes? */
123 
124  bool dependsOnRole; /* is plan specific to current role? */
125 
126  bool parallelModeOK; /* parallel mode potentially OK? */
127 
128  bool parallelModeNeeded; /* parallel mode actually required? */
129 
130  char maxParallelHazard; /* worst PROPARALLEL hazard level */
131 } PlannerGlobal;
132 
133 /* macro for fetching the Plan associated with a SubPlan node */
134 #define planner_subplan_get_plan(root, subplan) \
135  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
136 
137 
138 /*----------
139  * PlannerInfo
140  * Per-query information for planning/optimization
141  *
142  * This struct is conventionally called "root" in all the planner routines.
143  * It holds links to all of the planner's working state, in addition to the
144  * original Query. Note that at present the planner extensively modifies
145  * the passed-in Query data structure; someday that should stop.
146  *----------
147  */
148 typedef struct PlannerInfo
149 {
151 
152  Query *parse; /* the Query being planned */
153 
154  PlannerGlobal *glob; /* global info for current planner run */
155 
156  Index query_level; /* 1 at the outermost Query */
157 
158  struct PlannerInfo *parent_root; /* NULL at outermost Query */
159 
160  /*
161  * plan_params contains the expressions that this query level needs to
162  * make available to a lower query level that is currently being planned.
163  * outer_params contains the paramIds of PARAM_EXEC Params that outer
164  * query levels will make available to this query level.
165  */
166  List *plan_params; /* list of PlannerParamItems, see below */
168 
169  /*
170  * simple_rel_array holds pointers to "base rels" and "other rels" (see
171  * comments for RelOptInfo for more info). It is indexed by rangetable
172  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
173  * does not correspond to a base relation, such as a join RTE or an
174  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
175  */
176  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
177  int simple_rel_array_size; /* allocated size of array */
178 
179  /*
180  * simple_rte_array is the same length as simple_rel_array and holds
181  * pointers to the associated rangetable entries. This lets us avoid
182  * rt_fetch(), which can be a bit slow once large inheritance sets have
183  * been expanded.
184  */
185  RangeTblEntry **simple_rte_array; /* rangetable as an array */
186 
187  /*
188  * all_baserels is a Relids set of all base relids (but not "other"
189  * relids) in the query; that is, the Relids identifier of the final join
190  * we need to form. This is computed in make_one_rel, just before we
191  * start making Paths.
192  */
194 
195  /*
196  * nullable_baserels is a Relids set of base relids that are nullable by
197  * some outer join in the jointree; these are rels that are potentially
198  * nullable below the WHERE clause, SELECT targetlist, etc. This is
199  * computed in deconstruct_jointree.
200  */
202 
203  /*
204  * join_rel_list is a list of all join-relation RelOptInfos we have
205  * considered in this planning run. For small problems we just scan the
206  * list to do lookups, but when there are many join relations we build a
207  * hash table for faster lookups. The hash table is present and valid
208  * when join_rel_hash is not NULL. Note that we still maintain the list
209  * even when using the hash table for lookups; this simplifies life for
210  * GEQO.
211  */
212  List *join_rel_list; /* list of join-relation RelOptInfos */
213  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
214 
215  /*
216  * When doing a dynamic-programming-style join search, join_rel_level[k]
217  * is a list of all join-relation RelOptInfos of level k, and
218  * join_cur_level is the current level. New join-relation RelOptInfos are
219  * automatically added to the join_rel_level[join_cur_level] list.
220  * join_rel_level is NULL if not in use.
221  */
222  List **join_rel_level; /* lists of join-relation RelOptInfos */
223  int join_cur_level; /* index of list being extended */
224 
225  List *init_plans; /* init SubPlans for query */
226 
227  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
228 
229  List *multiexpr_params; /* List of Lists of Params for
230  * MULTIEXPR subquery outputs */
231 
232  List *eq_classes; /* list of active EquivalenceClasses */
233 
234  List *canon_pathkeys; /* list of "canonical" PathKeys */
235 
236  List *left_join_clauses; /* list of RestrictInfos for
237  * mergejoinable outer join clauses
238  * w/nonnullable var on left */
239 
240  List *right_join_clauses; /* list of RestrictInfos for
241  * mergejoinable outer join clauses
242  * w/nonnullable var on right */
243 
244  List *full_join_clauses; /* list of RestrictInfos for
245  * mergejoinable full join clauses */
246 
247  List *join_info_list; /* list of SpecialJoinInfos */
248 
249  List *append_rel_list; /* list of AppendRelInfos */
250 
251  List *rowMarks; /* list of PlanRowMarks */
252 
253  List *placeholder_list; /* list of PlaceHolderInfos */
254 
255  List *fkey_list; /* list of ForeignKeyOptInfos */
256 
257  List *query_pathkeys; /* desired pathkeys for query_planner() */
258 
259  List *group_pathkeys; /* groupClause pathkeys, if any */
260  List *window_pathkeys; /* pathkeys of bottom window, if any */
261  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
262  List *sort_pathkeys; /* sortClause pathkeys, if any */
263 
264  List *initial_rels; /* RelOptInfos we are now trying to join */
265 
266  /* Use fetch_upper_rel() to get any particular upper rel */
267  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
268 
269  /* Result tlists chosen by grouping_planner for upper-stage processing */
271 
272  /*
273  * grouping_planner passes back its final processed targetlist here, for
274  * use in relabeling the topmost tlist of the finished Plan.
275  */
277 
278  /* Fields filled during create_plan() for use in setrefs.c */
279  AttrNumber *grouping_map; /* for GroupingFunc fixup */
280  List *minmax_aggs; /* List of MinMaxAggInfos */
281 
282  MemoryContext planner_cxt; /* context holding PlannerInfo */
283 
284  double total_table_pages; /* # of pages in all tables of query */
285 
286  double tuple_fraction; /* tuple_fraction passed to query_planner */
287  double limit_tuples; /* limit_tuples passed to query_planner */
288 
289  Index qual_security_level; /* minimum security_level for quals */
290  /* Note: qual_security_level is zero if there are no securityQuals */
291 
292  bool hasInheritedTarget; /* true if parse->resultRelation is an
293  * inheritance child rel */
294  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
295  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
296  bool hasDeletedRTEs; /* true if any RTE was deleted from jointree */
297  bool hasHavingQual; /* true if havingQual was non-null */
298  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
299  * pseudoconstant = true */
300  bool hasRecursion; /* true if planning a recursive WITH item */
301 
302  /* These fields are used only when hasRecursion is true: */
303  int wt_param_id; /* PARAM_EXEC ID for the work table */
304  struct Path *non_recursive_path; /* a path for non-recursive term */
305 
306  /* These fields are workspace for createplan.c */
307  Relids curOuterRels; /* outer rels above current node */
308  List *curOuterParams; /* not-yet-assigned NestLoopParams */
309 
310  /* optional private data for join_search_hook, e.g., GEQO */
312 } PlannerInfo;
313 
314 
315 /*
316  * In places where it's known that simple_rte_array[] must have been prepared
317  * already, we just index into it to fetch RTEs. In code that might be
318  * executed before or after entering query_planner(), use this macro.
319  */
320 #define planner_rt_fetch(rti, root) \
321  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
322  rt_fetch(rti, (root)->parse->rtable))
323 
324 
325 /*----------
326  * RelOptInfo
327  * Per-relation information for planning/optimization
328  *
329  * For planning purposes, a "base rel" is either a plain relation (a table)
330  * or the output of a sub-SELECT or function that appears in the range table.
331  * In either case it is uniquely identified by an RT index. A "joinrel"
332  * is the joining of two or more base rels. A joinrel is identified by
333  * the set of RT indexes for its component baserels. We create RelOptInfo
334  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
335  * simple_rel_array and join_rel_list respectively.
336  *
337  * Note that there is only one joinrel for any given set of component
338  * baserels, no matter what order we assemble them in; so an unordered
339  * set is the right datatype to identify it with.
340  *
341  * We also have "other rels", which are like base rels in that they refer to
342  * single RT indexes; but they are not part of the join tree, and are given
343  * a different RelOptKind to identify them.
344  * Currently the only kind of otherrels are those made for member relations
345  * of an "append relation", that is an inheritance set or UNION ALL subquery.
346  * An append relation has a parent RTE that is a base rel, which represents
347  * the entire append relation. The member RTEs are otherrels. The parent
348  * is present in the query join tree but the members are not. The member
349  * RTEs and otherrels are used to plan the scans of the individual tables or
350  * subqueries of the append set; then the parent baserel is given Append
351  * and/or MergeAppend paths comprising the best paths for the individual
352  * member rels. (See comments for AppendRelInfo for more information.)
353  *
354  * At one time we also made otherrels to represent join RTEs, for use in
355  * handling join alias Vars. Currently this is not needed because all join
356  * alias Vars are expanded to non-aliased form during preprocess_expression.
357  *
358  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
359  * that describe post-scan/join processing steps, such as aggregation.
360  * Many of the fields in these RelOptInfos are meaningless, but their Path
361  * fields always hold Paths showing ways to do that processing step.
362  *
363  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
364  * that we have proven we don't need to join after all.
365  *
366  * Parts of this data structure are specific to various scan and join
367  * mechanisms. It didn't seem worth creating new node types for them.
368  *
369  * relids - Set of base-relation identifiers; it is a base relation
370  * if there is just one, a join relation if more than one
371  * rows - estimated number of tuples in the relation after restriction
372  * clauses have been applied (ie, output rows of a plan for it)
373  * consider_startup - true if there is any value in keeping plain paths for
374  * this rel on the basis of having cheap startup cost
375  * consider_param_startup - the same for parameterized paths
376  * reltarget - Default Path output tlist for this rel; normally contains
377  * Var and PlaceHolderVar nodes for the values we need to
378  * output from this relation.
379  * List is in no particular order, but all rels of an
380  * appendrel set must use corresponding orders.
381  * NOTE: in an appendrel child relation, may contain
382  * arbitrary expressions pulled up from a subquery!
383  * pathlist - List of Path nodes, one for each potentially useful
384  * method of generating the relation
385  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
386  * cheapest_startup_path - the pathlist member with lowest startup cost
387  * (regardless of ordering) among the unparameterized paths;
388  * or NULL if there is no unparameterized path
389  * cheapest_total_path - the pathlist member with lowest total cost
390  * (regardless of ordering) among the unparameterized paths;
391  * or if there is no unparameterized path, the path with lowest
392  * total cost among the paths with minimum parameterization
393  * cheapest_unique_path - for caching cheapest path to produce unique
394  * (no duplicates) output from relation; NULL if not yet requested
395  * cheapest_parameterized_paths - best paths for their parameterizations;
396  * always includes cheapest_total_path, even if that's unparameterized
397  * direct_lateral_relids - rels this rel has direct LATERAL references to
398  * lateral_relids - required outer rels for LATERAL, as a Relids set
399  * (includes both direct and indirect lateral references)
400  *
401  * If the relation is a base relation it will have these fields set:
402  *
403  * relid - RTE index (this is redundant with the relids field, but
404  * is provided for convenience of access)
405  * rtekind - distinguishes plain relation, subquery, or function RTE
406  * min_attr, max_attr - range of valid AttrNumbers for rel
407  * attr_needed - array of bitmapsets indicating the highest joinrel
408  * in which each attribute is needed; if bit 0 is set then
409  * the attribute is needed as part of final targetlist
410  * attr_widths - cache space for per-attribute width estimates;
411  * zero means not computed yet
412  * lateral_vars - lateral cross-references of rel, if any (list of
413  * Vars and PlaceHolderVars)
414  * lateral_referencers - relids of rels that reference this one laterally
415  * (includes both direct and indirect lateral references)
416  * indexlist - list of IndexOptInfo nodes for relation's indexes
417  * (always NIL if it's not a table)
418  * pages - number of disk pages in relation (zero if not a table)
419  * tuples - number of tuples in relation (not considering restrictions)
420  * allvisfrac - fraction of disk pages that are marked all-visible
421  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
422  * subplan_params - list of PlannerParamItems to be passed to subquery
423  *
424  * Note: for a subquery, tuples and subroot are not set immediately
425  * upon creation of the RelOptInfo object; they are filled in when
426  * set_subquery_pathlist processes the object.
427  *
428  * For otherrels that are appendrel members, these fields are filled
429  * in just as for a baserel, except we don't bother with lateral_vars.
430  *
431  * If the relation is either a foreign table or a join of foreign tables that
432  * all belong to the same foreign server and are assigned to the same user to
433  * check access permissions as (cf checkAsUser), these fields will be set:
434  *
435  * serverid - OID of foreign server, if foreign table (else InvalidOid)
436  * userid - OID of user to check access as (InvalidOid means current user)
437  * useridiscurrent - we've assumed that userid equals current user
438  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
439  * fdw_private - private state for FDW, if foreign table (else NULL)
440  *
441  * The presence of the remaining fields depends on the restrictions
442  * and joins that the relation participates in:
443  *
444  * baserestrictinfo - List of RestrictInfo nodes, containing info about
445  * each non-join qualification clause in which this relation
446  * participates (only used for base rels)
447  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
448  * clauses at a single tuple (only used for base rels)
449  * baserestrict_min_security - Smallest security_level found among
450  * clauses in baserestrictinfo
451  * joininfo - List of RestrictInfo nodes, containing info about each
452  * join clause in which this relation participates (but
453  * note this excludes clauses that might be derivable from
454  * EquivalenceClasses)
455  * has_eclass_joins - flag that EquivalenceClass joins are possible
456  *
457  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
458  * base rels, because for a join rel the set of clauses that are treated as
459  * restrict clauses varies depending on which sub-relations we choose to join.
460  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
461  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
462  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
463  * and should not be processed again at the level of {1 2 3}.) Therefore,
464  * the restrictinfo list in the join case appears in individual JoinPaths
465  * (field joinrestrictinfo), not in the parent relation. But it's OK for
466  * the RelOptInfo to store the joininfo list, because that is the same
467  * for a given rel no matter how we form it.
468  *
469  * We store baserestrictcost in the RelOptInfo (for base relations) because
470  * we know we will need it at least once (to price the sequential scan)
471  * and may need it multiple times to price index scans.
472  *----------
473  */
474 typedef enum RelOptKind
475 {
481 } RelOptKind;
482 
483 typedef struct RelOptInfo
484 {
486 
488 
489  /* all relations included in this RelOptInfo */
490  Relids relids; /* set of base relids (rangetable indexes) */
491 
492  /* size estimates generated by planner */
493  double rows; /* estimated number of result tuples */
494 
495  /* per-relation planner control flags */
496  bool consider_startup; /* keep cheap-startup-cost paths? */
497  bool consider_param_startup; /* ditto, for parameterized paths? */
498  bool consider_parallel; /* consider parallel paths? */
499 
500  /* default result targetlist for Paths scanning this relation */
501  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
502 
503  /* materialization information */
504  List *pathlist; /* Path structures */
505  List *ppilist; /* ParamPathInfos used in pathlist */
506  List *partial_pathlist; /* partial Paths */
511 
512  /* parameterization information needed for both base rels and join rels */
513  /* (see also lateral_vars and lateral_referencers) */
514  Relids direct_lateral_relids; /* rels directly laterally referenced */
515  Relids lateral_relids; /* minimum parameterization of rel */
516 
517  /* information about a base rel (not set for join rels!) */
519  Oid reltablespace; /* containing tablespace */
520  RTEKind rtekind; /* RELATION, SUBQUERY, or FUNCTION */
521  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
522  AttrNumber max_attr; /* largest attrno of rel */
523  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
524  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
525  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
526  Relids lateral_referencers; /* rels that reference me laterally */
527  List *indexlist; /* list of IndexOptInfo */
528  BlockNumber pages; /* size estimates derived from pg_class */
529  double tuples;
530  double allvisfrac;
531  PlannerInfo *subroot; /* if subquery */
532  List *subplan_params; /* if subquery */
533  int rel_parallel_workers; /* wanted number of parallel workers */
534 
535  /* Information about foreign tables and foreign joins */
536  Oid serverid; /* identifies server for the table or join */
537  Oid userid; /* identifies user to check access as */
538  bool useridiscurrent; /* join is only valid for current user */
539  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
541  void *fdw_private;
542 
543  /* used by various scans and joins: */
544  List *baserestrictinfo; /* RestrictInfo structures (if base
545  * rel) */
546  QualCost baserestrictcost; /* cost of evaluating the above */
547  Index baserestrict_min_security; /* min security_level found in
548  * baserestrictinfo */
549  List *joininfo; /* RestrictInfo structures for join clauses
550  * involving this rel */
551  bool has_eclass_joins; /* T means joininfo is incomplete */
552 } RelOptInfo;
553 
554 /*
555  * IndexOptInfo
556  * Per-index information for planning/optimization
557  *
558  * indexkeys[], indexcollations[], opfamily[], and opcintype[]
559  * each have ncolumns entries.
560  *
561  * sortopfamily[], reverse_sort[], and nulls_first[] likewise have
562  * ncolumns entries, if the index is ordered; but if it is unordered,
563  * those pointers are NULL.
564  *
565  * Zeroes in the indexkeys[] array indicate index columns that are
566  * expressions; there is one element in indexprs for each such column.
567  *
568  * For an ordered index, reverse_sort[] and nulls_first[] describe the
569  * sort ordering of a forward indexscan; we can also consider a backward
570  * indexscan, which will generate the reverse ordering.
571  *
572  * The indexprs and indpred expressions have been run through
573  * prepqual.c and eval_const_expressions() for ease of matching to
574  * WHERE clauses. indpred is in implicit-AND form.
575  *
576  * indextlist is a TargetEntry list representing the index columns.
577  * It provides an equivalent base-relation Var for each simple column,
578  * and links to the matching indexprs element for each expression column.
579  *
580  * While most of these fields are filled when the IndexOptInfo is created
581  * (by plancat.c), indrestrictinfo and predOK are set later, in
582  * check_index_predicates().
583  */
584 typedef struct IndexOptInfo
585 {
587 
588  Oid indexoid; /* OID of the index relation */
589  Oid reltablespace; /* tablespace of index (not table) */
590  RelOptInfo *rel; /* back-link to index's table */
591 
592  /* index-size statistics (from pg_class and elsewhere) */
593  BlockNumber pages; /* number of disk pages in index */
594  double tuples; /* number of index tuples in index */
595  int tree_height; /* index tree height, or -1 if unknown */
596 
597  /* index descriptor information */
598  int ncolumns; /* number of columns in index */
599  int *indexkeys; /* column numbers of index's keys, or 0 */
600  Oid *indexcollations; /* OIDs of collations of index columns */
601  Oid *opfamily; /* OIDs of operator families for columns */
602  Oid *opcintype; /* OIDs of opclass declared input data types */
603  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
604  bool *reverse_sort; /* is sort order descending? */
605  bool *nulls_first; /* do NULLs come first in the sort order? */
606  bool *canreturn; /* which index cols can be returned in an
607  * index-only scan? */
608  Oid relam; /* OID of the access method (in pg_am) */
609 
610  List *indexprs; /* expressions for non-simple index columns */
611  List *indpred; /* predicate if a partial index, else NIL */
612 
613  List *indextlist; /* targetlist representing index columns */
614 
615  List *indrestrictinfo;/* parent relation's baserestrictinfo list,
616  * less any conditions implied by the index's
617  * predicate (unless it's a target rel, see
618  * comments in check_index_predicates()) */
619 
620  bool predOK; /* true if index predicate matches query */
621  bool unique; /* true if a unique index */
622  bool immediate; /* is uniqueness enforced immediately? */
623  bool hypothetical; /* true if index doesn't really exist */
624 
625  /* Remaining fields are copied from the index AM's API struct: */
626  bool amcanorderbyop; /* does AM support order by operator result? */
627  bool amoptionalkey; /* can query omit key for the first column? */
628  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
629  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
630  bool amhasgettuple; /* does AM have amgettuple interface? */
631  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
632  bool amcanparallel; /* does AM support parallel scan? */
633  /* Rather than include amapi.h here, we declare amcostestimate like this */
634  void (*amcostestimate) (); /* AM's cost estimator */
635 } IndexOptInfo;
636 
637 /*
638  * ForeignKeyOptInfo
639  * Per-foreign-key information for planning/optimization
640  *
641  * The per-FK-column arrays can be fixed-size because we allow at most
642  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
643  * nkeys valid entries.
644  */
645 typedef struct ForeignKeyOptInfo
646 {
648 
649  /* Basic data about the foreign key (fetched from catalogs): */
650  Index con_relid; /* RT index of the referencing table */
651  Index ref_relid; /* RT index of the referenced table */
652  int nkeys; /* number of columns in the foreign key */
653  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
654  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
655  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
656 
657  /* Derived info about whether FK's equality conditions match the query: */
658  int nmatched_ec; /* # of FK cols matched by ECs */
659  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
660  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
661  /* Pointer to eclass matching each column's condition, if there is one */
663  /* List of non-EC RestrictInfos matching each column's condition */
666 
667 
668 /*
669  * EquivalenceClasses
670  *
671  * Whenever we can determine that a mergejoinable equality clause A = B is
672  * not delayed by any outer join, we create an EquivalenceClass containing
673  * the expressions A and B to record this knowledge. If we later find another
674  * equivalence B = C, we add C to the existing EquivalenceClass; this may
675  * require merging two existing EquivalenceClasses. At the end of the qual
676  * distribution process, we have sets of values that are known all transitively
677  * equal to each other, where "equal" is according to the rules of the btree
678  * operator family(s) shown in ec_opfamilies, as well as the collation shown
679  * by ec_collation. (We restrict an EC to contain only equalities whose
680  * operators belong to the same set of opfamilies. This could probably be
681  * relaxed, but for now it's not worth the trouble, since nearly all equality
682  * operators belong to only one btree opclass anyway. Similarly, we suppose
683  * that all or none of the input datatypes are collatable, so that a single
684  * collation value is sufficient.)
685  *
686  * We also use EquivalenceClasses as the base structure for PathKeys, letting
687  * us represent knowledge about different sort orderings being equivalent.
688  * Since every PathKey must reference an EquivalenceClass, we will end up
689  * with single-member EquivalenceClasses whenever a sort key expression has
690  * not been equivalenced to anything else. It is also possible that such an
691  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
692  * which is a case that can't arise otherwise since clauses containing
693  * volatile functions are never considered mergejoinable. We mark such
694  * EquivalenceClasses specially to prevent them from being merged with
695  * ordinary EquivalenceClasses. Also, for volatile expressions we have
696  * to be careful to match the EquivalenceClass to the correct targetlist
697  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
698  * So we record the SortGroupRef of the originating sort clause.
699  *
700  * We allow equality clauses appearing below the nullable side of an outer join
701  * to form EquivalenceClasses, but these have a slightly different meaning:
702  * the included values might be all NULL rather than all the same non-null
703  * values. See src/backend/optimizer/README for more on that point.
704  *
705  * NB: if ec_merged isn't NULL, this class has been merged into another, and
706  * should be ignored in favor of using the pointed-to class.
707  */
708 typedef struct EquivalenceClass
709 {
711 
712  List *ec_opfamilies; /* btree operator family OIDs */
713  Oid ec_collation; /* collation, if datatypes are collatable */
714  List *ec_members; /* list of EquivalenceMembers */
715  List *ec_sources; /* list of generating RestrictInfos */
716  List *ec_derives; /* list of derived RestrictInfos */
717  Relids ec_relids; /* all relids appearing in ec_members, except
718  * for child members (see below) */
719  bool ec_has_const; /* any pseudoconstants in ec_members? */
720  bool ec_has_volatile; /* the (sole) member is a volatile expr */
721  bool ec_below_outer_join; /* equivalence applies below an OJ */
722  bool ec_broken; /* failed to generate needed clauses? */
723  Index ec_sortref; /* originating sortclause label, or 0 */
724  Index ec_min_security; /* minimum security_level in ec_sources */
725  Index ec_max_security; /* maximum security_level in ec_sources */
726  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
728 
729 /*
730  * If an EC contains a const and isn't below-outer-join, any PathKey depending
731  * on it must be redundant, since there's only one possible value of the key.
732  */
733 #define EC_MUST_BE_REDUNDANT(eclass) \
734  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
735 
736 /*
737  * EquivalenceMember - one member expression of an EquivalenceClass
738  *
739  * em_is_child signifies that this element was built by transposing a member
740  * for an appendrel parent relation to represent the corresponding expression
741  * for an appendrel child. These members are used for determining the
742  * pathkeys of scans on the child relation and for explicitly sorting the
743  * child when necessary to build a MergeAppend path for the whole appendrel
744  * tree. An em_is_child member has no impact on the properties of the EC as a
745  * whole; in particular the EC's ec_relids field does NOT include the child
746  * relation. An em_is_child member should never be marked em_is_const nor
747  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
748  * members are not really full-fledged members of the EC, but just reflections
749  * or doppelgangers of real members. Most operations on EquivalenceClasses
750  * should ignore em_is_child members, and those that don't should test
751  * em_relids to make sure they only consider relevant members.
752  *
753  * em_datatype is usually the same as exprType(em_expr), but can be
754  * different when dealing with a binary-compatible opfamily; in particular
755  * anyarray_ops would never work without this. Use em_datatype when
756  * looking up a specific btree operator to work with this expression.
757  */
758 typedef struct EquivalenceMember
759 {
761 
762  Expr *em_expr; /* the expression represented */
763  Relids em_relids; /* all relids appearing in em_expr */
764  Relids em_nullable_relids; /* nullable by lower outer joins */
765  bool em_is_const; /* expression is pseudoconstant? */
766  bool em_is_child; /* derived version for a child relation? */
767  Oid em_datatype; /* the "nominal type" used by the opfamily */
769 
770 /*
771  * PathKeys
772  *
773  * The sort ordering of a path is represented by a list of PathKey nodes.
774  * An empty list implies no known ordering. Otherwise the first item
775  * represents the primary sort key, the second the first secondary sort key,
776  * etc. The value being sorted is represented by linking to an
777  * EquivalenceClass containing that value and including pk_opfamily among its
778  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
779  * This is a convenient method because it makes it trivial to detect
780  * equivalent and closely-related orderings. (See optimizer/README for more
781  * information.)
782  *
783  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
784  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
785  * index types will use btree-compatible strategy numbers.
786  */
787 typedef struct PathKey
788 {
790 
791  EquivalenceClass *pk_eclass; /* the value that is ordered */
792  Oid pk_opfamily; /* btree opfamily defining the ordering */
793  int pk_strategy; /* sort direction (ASC or DESC) */
794  bool pk_nulls_first; /* do NULLs come before normal values? */
795 } PathKey;
796 
797 
798 /*
799  * PathTarget
800  *
801  * This struct contains what we need to know during planning about the
802  * targetlist (output columns) that a Path will compute. Each RelOptInfo
803  * includes a default PathTarget, which its individual Paths may simply
804  * reference. However, in some cases a Path may compute outputs different
805  * from other Paths, and in that case we make a custom PathTarget for it.
806  * For example, an indexscan might return index expressions that would
807  * otherwise need to be explicitly calculated. (Note also that "upper"
808  * relations generally don't have useful default PathTargets.)
809  *
810  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
811  * though those will appear in finished Plans.
812  *
813  * sortgrouprefs[] is an array of the same length as exprs, containing the
814  * corresponding sort/group refnos, or zeroes for expressions not referenced
815  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
816  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
817  * we have not identified sort/group columns in this tlist. This allows us to
818  * deal with sort/group refnos when needed with less expense than including
819  * TargetEntry nodes in the exprs list.
820  */
821 typedef struct PathTarget
822 {
824  List *exprs; /* list of expressions to be computed */
825  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
826  QualCost cost; /* cost of evaluating the expressions */
827  int width; /* estimated avg width of result tuples */
828 } PathTarget;
829 
830 /* Convenience macro to get a sort/group refno from a PathTarget */
831 #define get_pathtarget_sortgroupref(target, colno) \
832  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
833 
834 
835 /*
836  * ParamPathInfo
837  *
838  * All parameterized paths for a given relation with given required outer rels
839  * link to a single ParamPathInfo, which stores common information such as
840  * the estimated rowcount for this parameterization. We do this partly to
841  * avoid recalculations, but mostly to ensure that the estimated rowcount
842  * is in fact the same for every such path.
843  *
844  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
845  * in join cases it's NIL because the set of relevant clauses varies depending
846  * on how the join is formed. The relevant clauses will appear in each
847  * parameterized join path's joinrestrictinfo list, instead.
848  */
849 typedef struct ParamPathInfo
850 {
852 
853  Relids ppi_req_outer; /* rels supplying parameters used by path */
854  double ppi_rows; /* estimated number of result tuples */
855  List *ppi_clauses; /* join clauses available from outer rels */
856 } ParamPathInfo;
857 
858 
859 /*
860  * Type "Path" is used as-is for sequential-scan paths, as well as some other
861  * simple plan types that we don't need any extra information in the path for.
862  * For other path types it is the first component of a larger struct.
863  *
864  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
865  * It is partially redundant with the Path's NodeTag, but allows us to use
866  * the same Path type for multiple Plan types when there is no need to
867  * distinguish the Plan type during path processing.
868  *
869  * "parent" identifies the relation this Path scans, and "pathtarget"
870  * describes the precise set of output columns the Path would compute.
871  * In simple cases all Paths for a given rel share the same targetlist,
872  * which we represent by having path->pathtarget equal to parent->reltarget.
873  *
874  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
875  * relation(s) that provide parameter values to each scan of this path.
876  * That means this path can only be joined to those rels by means of nestloop
877  * joins with this path on the inside. Also note that a parameterized path
878  * is responsible for testing all "movable" joinclauses involving this rel
879  * and the specified outer rel(s).
880  *
881  * "rows" is the same as parent->rows in simple paths, but in parameterized
882  * paths and UniquePaths it can be less than parent->rows, reflecting the
883  * fact that we've filtered by extra join conditions or removed duplicates.
884  *
885  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
886  * ordering of the path's output rows.
887  */
888 typedef struct Path
889 {
891 
892  NodeTag pathtype; /* tag identifying scan/join method */
893 
894  RelOptInfo *parent; /* the relation this path can build */
895  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
896 
897  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
898 
899  bool parallel_aware; /* engage parallel-aware logic? */
900  bool parallel_safe; /* OK to use as part of parallel plan? */
901  int parallel_workers; /* desired # of workers; 0 = not
902  * parallel */
903 
904  /* estimated size/costs for path (see costsize.c for more info) */
905  double rows; /* estimated number of result tuples */
906  Cost startup_cost; /* cost expended before fetching any tuples */
907  Cost total_cost; /* total cost (assuming all tuples fetched) */
908 
909  List *pathkeys; /* sort ordering of path's output */
910  /* pathkeys is a List of PathKey nodes; see above */
911 } Path;
912 
913 /* Macro for extracting a path's parameterization relids; beware double eval */
914 #define PATH_REQ_OUTER(path) \
915  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
916 
917 /*----------
918  * IndexPath represents an index scan over a single index.
919  *
920  * This struct is used for both regular indexscans and index-only scans;
921  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
922  *
923  * 'indexinfo' is the index to be scanned.
924  *
925  * 'indexclauses' is a list of index qualification clauses, with implicit
926  * AND semantics across the list. Each clause is a RestrictInfo node from
927  * the query's WHERE or JOIN conditions. An empty list implies a full
928  * index scan.
929  *
930  * 'indexquals' has the same structure as 'indexclauses', but it contains
931  * the actual index qual conditions that can be used with the index.
932  * In simple cases this is identical to 'indexclauses', but when special
933  * indexable operators appear in 'indexclauses', they are replaced by the
934  * derived indexscannable conditions in 'indexquals'.
935  *
936  * 'indexqualcols' is an integer list of index column numbers (zero-based)
937  * of the same length as 'indexquals', showing which index column each qual
938  * is meant to be used with. 'indexquals' is required to be ordered by
939  * index column, so 'indexqualcols' must form a nondecreasing sequence.
940  * (The order of multiple quals for the same index column is unspecified.)
941  *
942  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
943  * been found to be usable as ordering operators for an amcanorderbyop index.
944  * The list must match the path's pathkeys, ie, one expression per pathkey
945  * in the same order. These are not RestrictInfos, just bare expressions,
946  * since they generally won't yield booleans. Also, unlike the case for
947  * quals, it's guaranteed that each expression has the index key on the left
948  * side of the operator.
949  *
950  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
951  * of the same length as 'indexorderbys', showing which index column each
952  * ORDER BY expression is meant to be used with. (There is no restriction
953  * on which index column each ORDER BY can be used with.)
954  *
955  * 'indexscandir' is one of:
956  * ForwardScanDirection: forward scan of an ordered index
957  * BackwardScanDirection: backward scan of an ordered index
958  * NoMovementScanDirection: scan of an unordered index, or don't care
959  * (The executor doesn't care whether it gets ForwardScanDirection or
960  * NoMovementScanDirection for an indexscan, but the planner wants to
961  * distinguish ordered from unordered indexes for building pathkeys.)
962  *
963  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
964  * we need not recompute them when considering using the same index in a
965  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
966  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
967  *----------
968  */
969 typedef struct IndexPath
970 {
981 } IndexPath;
982 
983 /*
984  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
985  * instead of directly accessing the heap, followed by AND/OR combinations
986  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
987  * Note that the output is always considered unordered, since it will come
988  * out in physical heap order no matter what the underlying indexes did.
989  *
990  * The individual indexscans are represented by IndexPath nodes, and any
991  * logic on top of them is represented by a tree of BitmapAndPath and
992  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
993  * to represent a regular (or index-only) index scan plan, and as the child
994  * of a BitmapHeapPath that represents scanning the same index using a
995  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
996  * always represent the costs to use it as a regular (or index-only)
997  * IndexScan. The costs of a BitmapIndexScan can be computed using the
998  * IndexPath's indextotalcost and indexselectivity.
999  */
1000 typedef struct BitmapHeapPath
1001 {
1003  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1004 } BitmapHeapPath;
1005 
1006 /*
1007  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1008  * part of the substructure of a BitmapHeapPath. The Path structure is
1009  * a bit more heavyweight than we really need for this, but for simplicity
1010  * we make it a derivative of Path anyway.
1011  */
1012 typedef struct BitmapAndPath
1013 {
1015  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1017 } BitmapAndPath;
1018 
1019 /*
1020  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1021  * part of the substructure of a BitmapHeapPath. The Path structure is
1022  * a bit more heavyweight than we really need for this, but for simplicity
1023  * we make it a derivative of Path anyway.
1024  */
1025 typedef struct BitmapOrPath
1026 {
1028  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1030 } BitmapOrPath;
1031 
1032 /*
1033  * TidPath represents a scan by TID
1034  *
1035  * tidquals is an implicitly OR'ed list of qual expressions of the form
1036  * "CTID = pseudoconstant" or "CTID = ANY(pseudoconstant_array)".
1037  * Note they are bare expressions, not RestrictInfos.
1038  */
1039 typedef struct TidPath
1040 {
1042  List *tidquals; /* qual(s) involving CTID = something */
1043 } TidPath;
1044 
1045 /*
1046  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1047  *
1048  * Note that the subpath comes from a different planning domain; for example
1049  * RTE indexes within it mean something different from those known to the
1050  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1051  * interpret the subpath.
1052  */
1053 typedef struct SubqueryScanPath
1054 {
1056  Path *subpath; /* path representing subquery execution */
1058 
1059 /*
1060  * ForeignPath represents a potential scan of a foreign table, foreign join
1061  * or foreign upper-relation.
1062  *
1063  * fdw_private stores FDW private data about the scan. While fdw_private is
1064  * not actually touched by the core code during normal operations, it's
1065  * generally a good idea to use a representation that can be dumped by
1066  * nodeToString(), so that you can examine the structure during debugging
1067  * with tools like pprint().
1068  */
1069 typedef struct ForeignPath
1070 {
1074 } ForeignPath;
1075 
1076 /*
1077  * CustomPath represents a table scan done by some out-of-core extension.
1078  *
1079  * We provide a set of hooks here - which the provider must take care to set
1080  * up correctly - to allow extensions to supply their own methods of scanning
1081  * a relation. For example, a provider might provide GPU acceleration, a
1082  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1083  *
1084  * CustomPaths can be injected into the planning process for a relation by
1085  * set_rel_pathlist_hook functions.
1086  *
1087  * Core code must avoid assuming that the CustomPath is only as large as
1088  * the structure declared here; providers are allowed to make it the first
1089  * element in a larger structure. (Since the planner never copies Paths,
1090  * this doesn't add any complication.) However, for consistency with the
1091  * FDW case, we provide a "custom_private" field in CustomPath; providers
1092  * may prefer to use that rather than define another struct type.
1093  */
1094 
1095 struct CustomPathMethods;
1096 
1097 typedef struct CustomPath
1098 {
1100  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1101  * nodes/extensible.h */
1102  List *custom_paths; /* list of child Path nodes, if any */
1105 } CustomPath;
1106 
1107 /*
1108  * AppendPath represents an Append plan, ie, successive execution of
1109  * several member plans.
1110  *
1111  * Note: it is possible for "subpaths" to contain only one, or even no,
1112  * elements. These cases are optimized during create_append_plan.
1113  * In particular, an AppendPath with no subpaths is a "dummy" path that
1114  * is created to represent the case that a relation is provably empty.
1115  */
1116 typedef struct AppendPath
1117 {
1119  List *subpaths; /* list of component Paths */
1120 } AppendPath;
1121 
1122 #define IS_DUMMY_PATH(p) \
1123  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1124 
1125 /* A relation that's been proven empty will have one path that is dummy */
1126 #define IS_DUMMY_REL(r) \
1127  ((r)->cheapest_total_path != NULL && \
1128  IS_DUMMY_PATH((r)->cheapest_total_path))
1129 
1130 /*
1131  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1132  * results from several member plans to produce similarly-sorted output.
1133  */
1134 typedef struct MergeAppendPath
1135 {
1137  List *subpaths; /* list of component Paths */
1138  double limit_tuples; /* hard limit on output tuples, or -1 */
1139 } MergeAppendPath;
1140 
1141 /*
1142  * ResultPath represents use of a Result plan node to compute a variable-free
1143  * targetlist with no underlying tables (a "SELECT expressions" query).
1144  * The query could have a WHERE clause, too, represented by "quals".
1145  *
1146  * Note that quals is a list of bare clauses, not RestrictInfos.
1147  */
1148 typedef struct ResultPath
1149 {
1152 } ResultPath;
1153 
1154 /*
1155  * MaterialPath represents use of a Material plan node, i.e., caching of
1156  * the output of its subpath. This is used when the subpath is expensive
1157  * and needs to be scanned repeatedly, or when we need mark/restore ability
1158  * and the subpath doesn't have it.
1159  */
1160 typedef struct MaterialPath
1161 {
1164 } MaterialPath;
1165 
1166 /*
1167  * UniquePath represents elimination of distinct rows from the output of
1168  * its subpath.
1169  *
1170  * This can represent significantly different plans: either hash-based or
1171  * sort-based implementation, or a no-op if the input path can be proven
1172  * distinct already. The decision is sufficiently localized that it's not
1173  * worth having separate Path node types. (Note: in the no-op case, we could
1174  * eliminate the UniquePath node entirely and just return the subpath; but
1175  * it's convenient to have a UniquePath in the path tree to signal upper-level
1176  * routines that the input is known distinct.)
1177  */
1178 typedef enum
1179 {
1180  UNIQUE_PATH_NOOP, /* input is known unique already */
1181  UNIQUE_PATH_HASH, /* use hashing */
1182  UNIQUE_PATH_SORT /* use sorting */
1184 
1185 typedef struct UniquePath
1186 {
1190  List *in_operators; /* equality operators of the IN clause */
1191  List *uniq_exprs; /* expressions to be made unique */
1192 } UniquePath;
1193 
1194 /*
1195  * GatherPath runs several copies of a plan in parallel and collects the
1196  * results. The parallel leader may also execute the plan, unless the
1197  * single_copy flag is set.
1198  */
1199 typedef struct GatherPath
1200 {
1202  Path *subpath; /* path for each worker */
1203  bool single_copy; /* don't execute path more than once */
1204 } GatherPath;
1205 
1206 /*
1207  * All join-type paths share these fields.
1208  */
1209 
1210 typedef struct JoinPath
1211 {
1213 
1215 
1216  Path *outerjoinpath; /* path for the outer side of the join */
1217  Path *innerjoinpath; /* path for the inner side of the join */
1218 
1219  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1220 
1221  /*
1222  * See the notes for RelOptInfo and ParamPathInfo to understand why
1223  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1224  * parent RelOptInfo.
1225  */
1226 } JoinPath;
1227 
1228 /*
1229  * A nested-loop path needs no special fields.
1230  */
1231 
1233 
1234 /*
1235  * A mergejoin path has these fields.
1236  *
1237  * Unlike other path types, a MergePath node doesn't represent just a single
1238  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1239  * node itself, there can be a Sort node for the outer input, a Sort node
1240  * for the inner input, and/or a Material node for the inner input. We could
1241  * represent these nodes by separate path nodes, but considering how many
1242  * different merge paths are investigated during a complex join problem,
1243  * it seems better to avoid unnecessary palloc overhead.
1244  *
1245  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1246  * that will be used in the merge.
1247  *
1248  * Note that the mergeclauses are a subset of the parent relation's
1249  * restriction-clause list. Any join clauses that are not mergejoinable
1250  * appear only in the parent's restrict list, and must be checked by a
1251  * qpqual at execution time.
1252  *
1253  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1254  * (resp. inner path) is already ordered appropriately for the
1255  * mergejoin. If it is not NIL then it is a PathKeys list describing
1256  * the ordering that must be created by an explicit Sort node.
1257  *
1258  * materialize_inner is TRUE if a Material node should be placed atop the
1259  * inner input. This may appear with or without an inner Sort step.
1260  */
1261 
1262 typedef struct MergePath
1263 {
1265  List *path_mergeclauses; /* join clauses to be used for merge */
1266  List *outersortkeys; /* keys for explicit sort, if any */
1267  List *innersortkeys; /* keys for explicit sort, if any */
1268  bool materialize_inner; /* add Materialize to inner? */
1269 } MergePath;
1270 
1271 /*
1272  * A hashjoin path has these fields.
1273  *
1274  * The remarks above for mergeclauses apply for hashclauses as well.
1275  *
1276  * Hashjoin does not care what order its inputs appear in, so we have
1277  * no need for sortkeys.
1278  */
1279 
1280 typedef struct HashPath
1281 {
1283  List *path_hashclauses; /* join clauses used for hashing */
1284  int num_batches; /* number of batches expected */
1285 } HashPath;
1286 
1287 /*
1288  * ProjectionPath represents a projection (that is, targetlist computation)
1289  *
1290  * Nominally, this path node represents using a Result plan node to do a
1291  * projection step. However, if the input plan node supports projection,
1292  * we can just modify its output targetlist to do the required calculations
1293  * directly, and not need a Result. In some places in the planner we can just
1294  * jam the desired PathTarget into the input path node (and adjust its cost
1295  * accordingly), so we don't need a ProjectionPath. But in other places
1296  * it's necessary to not modify the input path node, so we need a separate
1297  * ProjectionPath node, which is marked dummy to indicate that we intend to
1298  * assign the work to the input plan node. The estimated cost for the
1299  * ProjectionPath node will account for whether a Result will be used or not.
1300  */
1301 typedef struct ProjectionPath
1302 {
1304  Path *subpath; /* path representing input source */
1305  bool dummypp; /* true if no separate Result is needed */
1306 } ProjectionPath;
1307 
1308 /*
1309  * ProjectSetPath represents evaluation of a targetlist that includes
1310  * set-returning function(s), which will need to be implemented by a
1311  * ProjectSet plan node.
1312  */
1313 typedef struct ProjectSetPath
1314 {
1316  Path *subpath; /* path representing input source */
1317 } ProjectSetPath;
1318 
1319 /*
1320  * SortPath represents an explicit sort step
1321  *
1322  * The sort keys are, by definition, the same as path.pathkeys.
1323  *
1324  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1325  * same as the input's pathtarget.
1326  */
1327 typedef struct SortPath
1328 {
1330  Path *subpath; /* path representing input source */
1331 } SortPath;
1332 
1333 /*
1334  * GroupPath represents grouping (of presorted input)
1335  *
1336  * groupClause represents the columns to be grouped on; the input path
1337  * must be at least that well sorted.
1338  *
1339  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1340  */
1341 typedef struct GroupPath
1342 {
1344  Path *subpath; /* path representing input source */
1345  List *groupClause; /* a list of SortGroupClause's */
1346  List *qual; /* quals (HAVING quals), if any */
1347 } GroupPath;
1348 
1349 /*
1350  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1351  *
1352  * The columns to be compared are the first numkeys columns of the path's
1353  * pathkeys. The input is presumed already sorted that way.
1354  */
1355 typedef struct UpperUniquePath
1356 {
1358  Path *subpath; /* path representing input source */
1359  int numkeys; /* number of pathkey columns to compare */
1360 } UpperUniquePath;
1361 
1362 /*
1363  * AggPath represents generic computation of aggregate functions
1364  *
1365  * This may involve plain grouping (but not grouping sets), using either
1366  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1367  * appropriately presorted.
1368  */
1369 typedef struct AggPath
1370 {
1372  Path *subpath; /* path representing input source */
1373  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1374  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1375  double numGroups; /* estimated number of groups in input */
1376  List *groupClause; /* a list of SortGroupClause's */
1377  List *qual; /* quals (HAVING quals), if any */
1378 } AggPath;
1379 
1380 /*
1381  * GroupingSetsPath represents a GROUPING SETS aggregation
1382  *
1383  * Currently we only support this in sorted not hashed form, so the input
1384  * must always be appropriately presorted.
1385  */
1386 typedef struct GroupingSetsPath
1387 {
1389  Path *subpath; /* path representing input source */
1390  List *rollup_groupclauses; /* list of lists of SortGroupClause's */
1391  List *rollup_lists; /* parallel list of lists of grouping sets */
1392  List *qual; /* quals (HAVING quals), if any */
1394 
1395 /*
1396  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1397  */
1398 typedef struct MinMaxAggPath
1399 {
1401  List *mmaggregates; /* list of MinMaxAggInfo */
1402  List *quals; /* HAVING quals, if any */
1403 } MinMaxAggPath;
1404 
1405 /*
1406  * WindowAggPath represents generic computation of window functions
1407  *
1408  * Note: winpathkeys is separate from path.pathkeys because the actual sort
1409  * order might be an extension of winpathkeys; but createplan.c needs to
1410  * know exactly how many pathkeys match the window clause.
1411  */
1412 typedef struct WindowAggPath
1413 {
1415  Path *subpath; /* path representing input source */
1416  WindowClause *winclause; /* WindowClause we'll be using */
1417  List *winpathkeys; /* PathKeys for PARTITION keys + ORDER keys */
1418 } WindowAggPath;
1419 
1420 /*
1421  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1422  */
1423 typedef struct SetOpPath
1424 {
1426  Path *subpath; /* path representing input source */
1427  SetOpCmd cmd; /* what to do, see nodes.h */
1428  SetOpStrategy strategy; /* how to do it, see nodes.h */
1429  List *distinctList; /* SortGroupClauses identifying target cols */
1430  AttrNumber flagColIdx; /* where is the flag column, if any */
1431  int firstFlag; /* flag value for first input relation */
1432  double numGroups; /* estimated number of groups in input */
1433 } SetOpPath;
1434 
1435 /*
1436  * RecursiveUnionPath represents a recursive UNION node
1437  */
1438 typedef struct RecursiveUnionPath
1439 {
1441  Path *leftpath; /* paths representing input sources */
1443  List *distinctList; /* SortGroupClauses identifying target cols */
1444  int wtParam; /* ID of Param representing work table */
1445  double numGroups; /* estimated number of groups in input */
1447 
1448 /*
1449  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1450  */
1451 typedef struct LockRowsPath
1452 {
1454  Path *subpath; /* path representing input source */
1455  List *rowMarks; /* a list of PlanRowMark's */
1456  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1457 } LockRowsPath;
1458 
1459 /*
1460  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1461  *
1462  * We represent most things that will be in the ModifyTable plan node
1463  * literally, except we have child Path(s) not Plan(s). But analysis of the
1464  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1465  */
1466 typedef struct ModifyTablePath
1467 {
1469  CmdType operation; /* INSERT, UPDATE, or DELETE */
1470  bool canSetTag; /* do we set the command tag/es_processed? */
1471  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1472  List *resultRelations; /* integer list of RT indexes */
1473  List *subpaths; /* Path(s) producing source data */
1474  List *subroots; /* per-target-table PlannerInfos */
1475  List *withCheckOptionLists; /* per-target-table WCO lists */
1476  List *returningLists; /* per-target-table RETURNING tlists */
1477  List *rowMarks; /* PlanRowMarks (non-locking only) */
1478  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1479  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1480 } ModifyTablePath;
1481 
1482 /*
1483  * LimitPath represents applying LIMIT/OFFSET restrictions
1484  */
1485 typedef struct LimitPath
1486 {
1488  Path *subpath; /* path representing input source */
1489  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1490  Node *limitCount; /* COUNT parameter, or NULL if none */
1491 } LimitPath;
1492 
1493 
1494 /*
1495  * Restriction clause info.
1496  *
1497  * We create one of these for each AND sub-clause of a restriction condition
1498  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1499  * ANDed, we can use any one of them or any subset of them to filter out
1500  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1501  * stores data used by the optimizer while choosing the best query plan.
1502  *
1503  * If a restriction clause references a single base relation, it will appear
1504  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1505  *
1506  * If a restriction clause references more than one base rel, it will
1507  * appear in the joininfo list of every RelOptInfo that describes a strict
1508  * subset of the base rels mentioned in the clause. The joininfo lists are
1509  * used to drive join tree building by selecting plausible join candidates.
1510  * The clause cannot actually be applied until we have built a join rel
1511  * containing all the base rels it references, however.
1512  *
1513  * When we construct a join rel that includes all the base rels referenced
1514  * in a multi-relation restriction clause, we place that clause into the
1515  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1516  * right sub-path includes all base rels referenced in the clause. The clause
1517  * will be applied at that join level, and will not propagate any further up
1518  * the join tree. (Note: the "predicate migration" code was once intended to
1519  * push restriction clauses up and down the plan tree based on evaluation
1520  * costs, but it's dead code and is unlikely to be resurrected in the
1521  * foreseeable future.)
1522  *
1523  * Note that in the presence of more than two rels, a multi-rel restriction
1524  * might reach different heights in the join tree depending on the join
1525  * sequence we use. So, these clauses cannot be associated directly with
1526  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1527  *
1528  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1529  * equalities that are not outerjoin-delayed) are handled a bit differently.
1530  * Initially we attach them to the EquivalenceClasses that are derived from
1531  * them. When we construct a scan or join path, we look through all the
1532  * EquivalenceClasses and generate derived RestrictInfos representing the
1533  * minimal set of conditions that need to be checked for this particular scan
1534  * or join to enforce that all members of each EquivalenceClass are in fact
1535  * equal in all rows emitted by the scan or join.
1536  *
1537  * When dealing with outer joins we have to be very careful about pushing qual
1538  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1539  * be evaluated exactly at that join node, unless they are "degenerate"
1540  * conditions that reference only Vars from the nullable side of the join.
1541  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1542  * down below the outer join, if they reference any nullable Vars.
1543  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1544  * pushed down to a lower level than its original syntactic placement in the
1545  * join tree would suggest. If an outer join prevents us from pushing a qual
1546  * down to its "natural" semantic level (the level associated with just the
1547  * base rels used in the qual) then we mark the qual with a "required_relids"
1548  * value including more than just the base rels it actually uses. By
1549  * pretending that the qual references all the rels required to form the outer
1550  * join, we prevent it from being evaluated below the outer join's joinrel.
1551  * When we do form the outer join's joinrel, we still need to distinguish
1552  * those quals that are actually in that join's JOIN/ON condition from those
1553  * that appeared elsewhere in the tree and were pushed down to the join rel
1554  * because they used no other rels. That's what the is_pushed_down flag is
1555  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1556  * rels listed in required_relids. A clause that originally came from WHERE
1557  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1558  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1559  * if we decide that it can be pushed down into the nullable side of the join.
1560  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1561  * (In short, is_pushed_down is only false for non-degenerate outer join
1562  * conditions. Possibly we should rename it to reflect that meaning?)
1563  *
1564  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1565  * if the clause's applicability must be delayed due to any outer joins
1566  * appearing below it (ie, it has to be postponed to some join level higher
1567  * than the set of relations it actually references).
1568  *
1569  * There is also an outer_relids field, which is NULL except for outer join
1570  * clauses; for those, it is the set of relids on the outer side of the
1571  * clause's outer join. (These are rels that the clause cannot be applied to
1572  * in parameterized scans, since pushing it into the join's outer side would
1573  * lead to wrong answers.)
1574  *
1575  * There is also a nullable_relids field, which is the set of rels the clause
1576  * references that can be forced null by some outer join below the clause.
1577  *
1578  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1579  * a clause might reference some nullable rels and yet not be
1580  * outerjoin_delayed because it also references all the other rels of the
1581  * outer join(s). A clause that is not outerjoin_delayed can be enforced
1582  * anywhere it is computable.
1583  *
1584  * To handle security-barrier conditions efficiently, we mark RestrictInfo
1585  * nodes with a security_level field, in which higher values identify clauses
1586  * coming from less-trusted sources. The exact semantics are that a clause
1587  * cannot be evaluated before another clause with a lower security_level value
1588  * unless the first clause is leakproof. As with outer-join clauses, this
1589  * creates a reason for clauses to sometimes need to be evaluated higher in
1590  * the join tree than their contents would suggest; and even at a single plan
1591  * node, this rule constrains the order of application of clauses.
1592  *
1593  * In general, the referenced clause might be arbitrarily complex. The
1594  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
1595  * or hashjoin clauses are limited (e.g., no volatile functions). The code
1596  * for each kind of path is responsible for identifying the restrict clauses
1597  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
1598  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
1599  * of the finished Plan node, where they will be enforced by general-purpose
1600  * qual-expression-evaluation code. (But we are still entitled to count
1601  * their selectivity when estimating the result tuple count, if we
1602  * can guess what it is...)
1603  *
1604  * When the referenced clause is an OR clause, we generate a modified copy
1605  * in which additional RestrictInfo nodes are inserted below the top-level
1606  * OR/AND structure. This is a convenience for OR indexscan processing:
1607  * indexquals taken from either the top level or an OR subclause will have
1608  * associated RestrictInfo nodes.
1609  *
1610  * The can_join flag is set true if the clause looks potentially useful as
1611  * a merge or hash join clause, that is if it is a binary opclause with
1612  * nonoverlapping sets of relids referenced in the left and right sides.
1613  * (Whether the operator is actually merge or hash joinable isn't checked,
1614  * however.)
1615  *
1616  * The pseudoconstant flag is set true if the clause contains no Vars of
1617  * the current query level and no volatile functions. Such a clause can be
1618  * pulled out and used as a one-time qual in a gating Result node. We keep
1619  * pseudoconstant clauses in the same lists as other RestrictInfos so that
1620  * the regular clause-pushing machinery can assign them to the correct join
1621  * level, but they need to be treated specially for cost and selectivity
1622  * estimates. Note that a pseudoconstant clause can never be an indexqual
1623  * or merge or hash join clause, so it's of no interest to large parts of
1624  * the planner.
1625  *
1626  * When join clauses are generated from EquivalenceClasses, there may be
1627  * several equally valid ways to enforce join equivalence, of which we need
1628  * apply only one. We mark clauses of this kind by setting parent_ec to
1629  * point to the generating EquivalenceClass. Multiple clauses with the same
1630  * parent_ec in the same join are redundant.
1631  */
1632 
1633 typedef struct RestrictInfo
1634 {
1636 
1637  Expr *clause; /* the represented clause of WHERE or JOIN */
1638 
1639  bool is_pushed_down; /* TRUE if clause was pushed down in level */
1640 
1641  bool outerjoin_delayed; /* TRUE if delayed by lower outer join */
1642 
1643  bool can_join; /* see comment above */
1644 
1645  bool pseudoconstant; /* see comment above */
1646 
1647  bool leakproof; /* TRUE if known to contain no leaked Vars */
1648 
1649  Index security_level; /* see comment above */
1650 
1651  /* The set of relids (varnos) actually referenced in the clause: */
1653 
1654  /* The set of relids required to evaluate the clause: */
1656 
1657  /* If an outer-join clause, the outer-side relations, else NULL: */
1659 
1660  /* The relids used in the clause that are nullable by lower outer joins: */
1662 
1663  /* These fields are set for any binary opclause: */
1664  Relids left_relids; /* relids in left side of clause */
1665  Relids right_relids; /* relids in right side of clause */
1666 
1667  /* This field is NULL unless clause is an OR clause: */
1668  Expr *orclause; /* modified clause with RestrictInfos */
1669 
1670  /* This field is NULL unless clause is potentially redundant: */
1671  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
1672 
1673  /* cache space for cost and selectivity */
1674  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
1675  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
1676  * semantics; -1 if not yet set; >1 means a
1677  * redundant clause */
1678  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
1679  * not yet set */
1680 
1681  /* valid if clause is mergejoinable, else NIL */
1682  List *mergeopfamilies; /* opfamilies containing clause operator */
1683 
1684  /* cache space for mergeclause processing; NULL if not yet set */
1685  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
1686  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
1687  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
1688  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
1689  List *scansel_cache; /* list of MergeScanSelCache structs */
1690 
1691  /* transient workspace for use while considering a specific join path */
1692  bool outer_is_left; /* T = outer var on left, F = on right */
1693 
1694  /* valid if clause is hashjoinable, else InvalidOid: */
1695  Oid hashjoinoperator; /* copy of clause operator */
1696 
1697  /* cache space for hashclause processing; -1 if not yet set */
1698  Selectivity left_bucketsize; /* avg bucketsize of left side */
1699  Selectivity right_bucketsize; /* avg bucketsize of right side */
1700 } RestrictInfo;
1701 
1702 /*
1703  * Since mergejoinscansel() is a relatively expensive function, and would
1704  * otherwise be invoked many times while planning a large join tree,
1705  * we go out of our way to cache its results. Each mergejoinable
1706  * RestrictInfo carries a list of the specific sort orderings that have
1707  * been considered for use with it, and the resulting selectivities.
1708  */
1709 typedef struct MergeScanSelCache
1710 {
1711  /* Ordering details (cache lookup key) */
1712  Oid opfamily; /* btree opfamily defining the ordering */
1713  Oid collation; /* collation for the ordering */
1714  int strategy; /* sort direction (ASC or DESC) */
1715  bool nulls_first; /* do NULLs come before normal values? */
1716  /* Results */
1717  Selectivity leftstartsel; /* first-join fraction for clause left side */
1718  Selectivity leftendsel; /* last-join fraction for clause left side */
1719  Selectivity rightstartsel; /* first-join fraction for clause right side */
1720  Selectivity rightendsel; /* last-join fraction for clause right side */
1722 
1723 /*
1724  * Placeholder node for an expression to be evaluated below the top level
1725  * of a plan tree. This is used during planning to represent the contained
1726  * expression. At the end of the planning process it is replaced by either
1727  * the contained expression or a Var referring to a lower-level evaluation of
1728  * the contained expression. Typically the evaluation occurs below an outer
1729  * join, and Var references above the outer join might thereby yield NULL
1730  * instead of the expression value.
1731  *
1732  * Although the planner treats this as an expression node type, it is not
1733  * recognized by the parser or executor, so we declare it here rather than
1734  * in primnodes.h.
1735  */
1736 
1737 typedef struct PlaceHolderVar
1738 {
1740  Expr *phexpr; /* the represented expression */
1741  Relids phrels; /* base relids syntactically within expr src */
1742  Index phid; /* ID for PHV (unique within planner run) */
1743  Index phlevelsup; /* > 0 if PHV belongs to outer query */
1744 } PlaceHolderVar;
1745 
1746 /*
1747  * "Special join" info.
1748  *
1749  * One-sided outer joins constrain the order of joining partially but not
1750  * completely. We flatten such joins into the planner's top-level list of
1751  * relations to join, but record information about each outer join in a
1752  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
1753  * join_info_list.
1754  *
1755  * Similarly, semijoins and antijoins created by flattening IN (subselect)
1756  * and EXISTS(subselect) clauses create partial constraints on join order.
1757  * These are likewise recorded in SpecialJoinInfo structs.
1758  *
1759  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
1760  * of planning for them, because this simplifies make_join_rel()'s API.
1761  *
1762  * min_lefthand and min_righthand are the sets of base relids that must be
1763  * available on each side when performing the special join. lhs_strict is
1764  * true if the special join's condition cannot succeed when the LHS variables
1765  * are all NULL (this means that an outer join can commute with upper-level
1766  * outer joins even if it appears in their RHS). We don't bother to set
1767  * lhs_strict for FULL JOINs, however.
1768  *
1769  * It is not valid for either min_lefthand or min_righthand to be empty sets;
1770  * if they were, this would break the logic that enforces join order.
1771  *
1772  * syn_lefthand and syn_righthand are the sets of base relids that are
1773  * syntactically below this special join. (These are needed to help compute
1774  * min_lefthand and min_righthand for higher joins.)
1775  *
1776  * delay_upper_joins is set TRUE if we detect a pushed-down clause that has
1777  * to be evaluated after this join is formed (because it references the RHS).
1778  * Any outer joins that have such a clause and this join in their RHS cannot
1779  * commute with this join, because that would leave noplace to check the
1780  * pushed-down clause. (We don't track this for FULL JOINs, either.)
1781  *
1782  * For a semijoin, we also extract the join operators and their RHS arguments
1783  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
1784  * This is done in support of possibly unique-ifying the RHS, so we don't
1785  * bother unless at least one of semi_can_btree and semi_can_hash can be set
1786  * true. (You might expect that this information would be computed during
1787  * join planning; but it's helpful to have it available during planning of
1788  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
1789  *
1790  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
1791  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
1792  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
1793  *
1794  * For purposes of join selectivity estimation, we create transient
1795  * SpecialJoinInfo structures for regular inner joins; so it is possible
1796  * to have jointype == JOIN_INNER in such a structure, even though this is
1797  * not allowed within join_info_list. We also create transient
1798  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
1799  * cost estimation purposes it is sometimes useful to know the join size under
1800  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
1801  * of course the semi_xxx fields are not set meaningfully within such structs.
1802  */
1803 
1804 typedef struct SpecialJoinInfo
1805 {
1807  Relids min_lefthand; /* base relids in minimum LHS for join */
1808  Relids min_righthand; /* base relids in minimum RHS for join */
1809  Relids syn_lefthand; /* base relids syntactically within LHS */
1810  Relids syn_righthand; /* base relids syntactically within RHS */
1811  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
1812  bool lhs_strict; /* joinclause is strict for some LHS rel */
1813  bool delay_upper_joins; /* can't commute with upper RHS */
1814  /* Remaining fields are set only for JOIN_SEMI jointype: */
1815  bool semi_can_btree; /* true if semi_operators are all btree */
1816  bool semi_can_hash; /* true if semi_operators are all hash */
1817  List *semi_operators; /* OIDs of equality join operators */
1818  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
1819 } SpecialJoinInfo;
1820 
1821 /*
1822  * Append-relation info.
1823  *
1824  * When we expand an inheritable table or a UNION-ALL subselect into an
1825  * "append relation" (essentially, a list of child RTEs), we build an
1826  * AppendRelInfo for each child RTE. The list of AppendRelInfos indicates
1827  * which child RTEs must be included when expanding the parent, and each
1828  * node carries information needed to translate Vars referencing the parent
1829  * into Vars referencing that child.
1830  *
1831  * These structs are kept in the PlannerInfo node's append_rel_list.
1832  * Note that we just throw all the structs into one list, and scan the
1833  * whole list when desiring to expand any one parent. We could have used
1834  * a more complex data structure (eg, one list per parent), but this would
1835  * be harder to update during operations such as pulling up subqueries,
1836  * and not really any easier to scan. Considering that typical queries
1837  * will not have many different append parents, it doesn't seem worthwhile
1838  * to complicate things.
1839  *
1840  * Note: after completion of the planner prep phase, any given RTE is an
1841  * append parent having entries in append_rel_list if and only if its
1842  * "inh" flag is set. We clear "inh" for plain tables that turn out not
1843  * to have inheritance children, and (in an abuse of the original meaning
1844  * of the flag) we set "inh" for subquery RTEs that turn out to be
1845  * flattenable UNION ALL queries. This lets us avoid useless searches
1846  * of append_rel_list.
1847  *
1848  * Note: the data structure assumes that append-rel members are single
1849  * baserels. This is OK for inheritance, but it prevents us from pulling
1850  * up a UNION ALL member subquery if it contains a join. While that could
1851  * be fixed with a more complex data structure, at present there's not much
1852  * point because no improvement in the plan could result.
1853  */
1854 
1855 typedef struct AppendRelInfo
1856 {
1858 
1859  /*
1860  * These fields uniquely identify this append relationship. There can be
1861  * (in fact, always should be) multiple AppendRelInfos for the same
1862  * parent_relid, but never more than one per child_relid, since a given
1863  * RTE cannot be a child of more than one append parent.
1864  */
1865  Index parent_relid; /* RT index of append parent rel */
1866  Index child_relid; /* RT index of append child rel */
1867 
1868  /*
1869  * For an inheritance appendrel, the parent and child are both regular
1870  * relations, and we store their rowtype OIDs here for use in translating
1871  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
1872  * both subqueries with no named rowtype, and we store InvalidOid here.
1873  */
1874  Oid parent_reltype; /* OID of parent's composite type */
1875  Oid child_reltype; /* OID of child's composite type */
1876 
1877  /*
1878  * The N'th element of this list is a Var or expression representing the
1879  * child column corresponding to the N'th column of the parent. This is
1880  * used to translate Vars referencing the parent rel into references to
1881  * the child. A list element is NULL if it corresponds to a dropped
1882  * column of the parent (this is only possible for inheritance cases, not
1883  * UNION ALL). The list elements are always simple Vars for inheritance
1884  * cases, but can be arbitrary expressions in UNION ALL cases.
1885  *
1886  * Notice we only store entries for user columns (attno > 0). Whole-row
1887  * Vars are special-cased, and system columns (attno < 0) need no special
1888  * translation since their attnos are the same for all tables.
1889  *
1890  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
1891  * when copying into a subquery.
1892  */
1893  List *translated_vars; /* Expressions in the child's Vars */
1894 
1895  /*
1896  * We store the parent table's OID here for inheritance, or InvalidOid for
1897  * UNION ALL. This is only needed to help in generating error messages if
1898  * an attempt is made to reference a dropped parent column.
1899  */
1900  Oid parent_reloid; /* OID of parent relation */
1901 } AppendRelInfo;
1902 
1903 /*
1904  * For each distinct placeholder expression generated during planning, we
1905  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
1906  * This stores info that is needed centrally rather than in each copy of the
1907  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
1908  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
1909  * not just within a query level --- this is so that we need not reassign ID's
1910  * when pulling a subquery into its parent.
1911  *
1912  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
1913  * then allow it to bubble up like a Var until the ph_needed join level.
1914  * ph_needed has the same definition as attr_needed for a regular Var.
1915  *
1916  * The PlaceHolderVar's expression might contain LATERAL references to vars
1917  * coming from outside its syntactic scope. If so, those rels are *not*
1918  * included in ph_eval_at, but they are recorded in ph_lateral.
1919  *
1920  * Notice that when ph_eval_at is a join rather than a single baserel, the
1921  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
1922  * has to be formed below any outer joins that should null the PlaceHolderVar.
1923  *
1924  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
1925  * is actually referenced in the plan tree, so that unreferenced placeholders
1926  * don't result in unnecessary constraints on join order.
1927  */
1928 
1929 typedef struct PlaceHolderInfo
1930 {
1932 
1933  Index phid; /* ID for PH (unique within planner run) */
1934  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
1935  Relids ph_eval_at; /* lowest level we can evaluate value at */
1936  Relids ph_lateral; /* relids of contained lateral refs, if any */
1937  Relids ph_needed; /* highest level the value is needed at */
1938  int32 ph_width; /* estimated attribute width */
1939 } PlaceHolderInfo;
1940 
1941 /*
1942  * This struct describes one potentially index-optimizable MIN/MAX aggregate
1943  * function. MinMaxAggPath contains a list of these, and if we accept that
1944  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
1945  */
1946 typedef struct MinMaxAggInfo
1947 {
1949 
1950  Oid aggfnoid; /* pg_proc Oid of the aggregate */
1951  Oid aggsortop; /* Oid of its sort operator */
1952  Expr *target; /* expression we are aggregating on */
1953  PlannerInfo *subroot; /* modified "root" for planning the subquery */
1954  Path *path; /* access path for subquery */
1955  Cost pathcost; /* estimated cost to fetch first row */
1956  Param *param; /* param for subplan's output */
1957 } MinMaxAggInfo;
1958 
1959 /*
1960  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
1961  * node to another. They can be used to pass values down into subqueries (for
1962  * outer references in subqueries), or up out of subqueries (for the results
1963  * of a subplan), or from a NestLoop plan node into its inner relation (when
1964  * the inner scan is parameterized with values from the outer relation).
1965  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
1966  * the PARAM_EXEC Params it generates.
1967  *
1968  * Outer references are managed via root->plan_params, which is a list of
1969  * PlannerParamItems. While planning a subquery, each parent query level's
1970  * plan_params contains the values required from it by the current subquery.
1971  * During create_plan(), we use plan_params to track values that must be
1972  * passed from outer to inner sides of NestLoop plan nodes.
1973  *
1974  * The item a PlannerParamItem represents can be one of three kinds:
1975  *
1976  * A Var: the slot represents a variable of this level that must be passed
1977  * down because subqueries have outer references to it, or must be passed
1978  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
1979  * will always be zero.
1980  *
1981  * A PlaceHolderVar: this works much like the Var case, except that the
1982  * entry is a PlaceHolderVar node with a contained expression. The PHV
1983  * will have phlevelsup = 0, and the contained expression is adjusted
1984  * to match in level.
1985  *
1986  * An Aggref (with an expression tree representing its argument): the slot
1987  * represents an aggregate expression that is an outer reference for some
1988  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
1989  * is adjusted to match in level.
1990  *
1991  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
1992  * them into one slot, but we do not bother to do that for Aggrefs.
1993  * The scope of duplicate-elimination only extends across the set of
1994  * parameters passed from one query level into a single subquery, or for
1995  * nestloop parameters across the set of nestloop parameters used in a single
1996  * query level. So there is no possibility of a PARAM_EXEC slot being used
1997  * for conflicting purposes.
1998  *
1999  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2000  * from subplans (values that are setParam items for those subplans). These
2001  * IDs need not be tracked via PlannerParamItems, since we do not need any
2002  * duplicate-elimination nor later processing of the represented expressions.
2003  * Instead, we just record the assignment of the slot number by incrementing
2004  * root->glob->nParamExec.
2005  */
2006 typedef struct PlannerParamItem
2007 {
2009 
2010  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2011  int paramId; /* its assigned PARAM_EXEC slot number */
2013 
2014 /*
2015  * When making cost estimates for a SEMI or ANTI join, there are some
2016  * correction factors that are needed in both nestloop and hash joins
2017  * to account for the fact that the executor can stop scanning inner rows
2018  * as soon as it finds a match to the current outer row. These numbers
2019  * depend only on the selected outer and inner join relations, not on the
2020  * particular paths used for them, so it's worthwhile to calculate them
2021  * just once per relation pair not once per considered path. This struct
2022  * is filled by compute_semi_anti_join_factors and must be passed along
2023  * to the join cost estimation functions.
2024  *
2025  * outer_match_frac is the fraction of the outer tuples that are
2026  * expected to have at least one match.
2027  * match_count is the average number of matches expected for
2028  * outer tuples that have at least one match.
2029  */
2030 typedef struct SemiAntiJoinFactors
2031 {
2035 
2036 /*
2037  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2038  *
2039  * restrictlist contains all of the RestrictInfo nodes for restriction
2040  * clauses that apply to this join
2041  * mergeclause_list is a list of RestrictInfo nodes for available
2042  * mergejoin clauses in this join
2043  * sjinfo is extra info about special joins for selectivity estimation
2044  * semifactors is as shown above (only valid for SEMI or ANTI joins)
2045  * param_source_rels are OK targets for parameterization of result paths
2046  */
2047 typedef struct JoinPathExtraData
2048 {
2055 
2056 /*
2057  * For speed reasons, cost estimation for join paths is performed in two
2058  * phases: the first phase tries to quickly derive a lower bound for the
2059  * join cost, and then we check if that's sufficient to reject the path.
2060  * If not, we come back for a more refined cost estimate. The first phase
2061  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2062  * and possibly additional intermediate values. The second phase takes
2063  * these values as inputs to avoid repeating work.
2064  *
2065  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2066  * so seems best to put it here.)
2067  */
2068 typedef struct JoinCostWorkspace
2069 {
2070  /* Preliminary cost estimates --- must not be larger than final ones! */
2071  Cost startup_cost; /* cost expended before fetching any tuples */
2072  Cost total_cost; /* total cost (assuming all tuples fetched) */
2073 
2074  /* Fields below here should be treated as private to costsize.c */
2075  Cost run_cost; /* non-startup cost components */
2076 
2077  /* private for cost_nestloop code */
2078  Cost inner_run_cost; /* also used by cost_mergejoin code */
2080 
2081  /* private for cost_mergejoin code */
2082  double outer_rows;
2083  double inner_rows;
2086 
2087  /* private for cost_hashjoin code */
2091 
2092 #endif /* RELATION_H */
QualCost eval_cost
Definition: relation.h:1674
bool has_eclass_joins
Definition: relation.h:551
struct ModifyTablePath ModifyTablePath
struct Path * cheapest_unique_path
Definition: relation.h:509
List * indexorderbycols
Definition: relation.h:977
char maxParallelHazard
Definition: relation.h:130
List * group_pathkeys
Definition: relation.h:259
struct MinMaxAggPath MinMaxAggPath
List * rowMarks
Definition: relation.h:251
struct ForeignKeyOptInfo ForeignKeyOptInfo
Relids ph_needed
Definition: relation.h:1937
List * qual
Definition: relation.h:1346
bool semi_can_btree
Definition: relation.h:1815
Selectivity leftendsel
Definition: relation.h:1718
List * path_mergeclauses
Definition: relation.h:1265
int join_cur_level
Definition: relation.h:223
List * outersortkeys
Definition: relation.h:1266
List * distinctList
Definition: relation.h:1429
JoinPath jpath
Definition: relation.h:1282
PathTarget * pathtarget
Definition: relation.h:895
Query * parse
Definition: relation.h:152
List * returningLists
Definition: relation.h:1476
struct PathTarget PathTarget
Index security_level
Definition: relation.h:1649
OnConflictExpr * onconflict
Definition: relation.h:1478
bool predOK
Definition: relation.h:620
Node * limitOffset
Definition: relation.h:1489
Path * subpath
Definition: relation.h:1358
struct PlaceHolderInfo PlaceHolderInfo
Path path
Definition: relation.h:971
NodeTag type
Definition: relation.h:1857
Path * subpath
Definition: relation.h:1330
Relids ph_eval_at
Definition: relation.h:1935
List * plan_params
Definition: relation.h:166
PlaceHolderVar * ph_var
Definition: relation.h:1934
IndexOptInfo * indexinfo
Definition: relation.h:972
SemiAntiJoinFactors semifactors
Definition: relation.h:2052
Index nominalRelation
Definition: relation.h:1471
Oid * indexcollations
Definition: relation.h:600
bool hasJoinRTEs
Definition: relation.h:294
Path * fdw_outerpath
Definition: relation.h:1072
RelOptKind reloptkind
Definition: relation.h:487
Relids * attr_needed
Definition: relation.h:523
List * custom_paths
Definition: relation.h:1102
List * query_pathkeys
Definition: relation.h:257
int num_batches
Definition: relation.h:1284
List * join_info_list
Definition: relation.h:247
Relids required_relids
Definition: relation.h:1655
SetOpStrategy strategy
Definition: relation.h:1428
Relids min_righthand
Definition: relation.h:1808
AggStrategy aggstrategy
Definition: relation.h:1373
bool materialize_inner
Definition: relation.h:1268
void * join_search_private
Definition: relation.h:311
Relids curOuterRels
Definition: relation.h:307
List * qual
Definition: relation.h:1377
bool leakproof
Definition: relation.h:1647
Index ec_min_security
Definition: relation.h:724
Expr * orclause
Definition: relation.h:1668
Selectivity outer_match_frac
Definition: relation.h:2032
Path * innerjoinpath
Definition: relation.h:1217
struct BitmapOrPath BitmapOrPath
List * indextlist
Definition: relation.h:613
struct AppendPath AppendPath
struct Path * cheapest_startup_path
Definition: relation.h:507
struct LockRowsPath LockRowsPath
Oid userid
Definition: relation.h:537
struct IndexPath IndexPath
struct CustomPath CustomPath
Relids em_nullable_relids
Definition: relation.h:764
int lastPlanNodeId
Definition: relation.h:120
double tuples
Definition: relation.h:529
Oid reltablespace
Definition: relation.h:519
Path * subpath
Definition: relation.h:1426
List * baserestrictinfo
Definition: relation.h:544
NodeTag type
Definition: relation.h:890
List * ec_derives
Definition: relation.h:716
struct UniquePath UniquePath
List * rowMarks
Definition: relation.h:1477
NodeTag type
Definition: relation.h:1806
struct SpecialJoinInfo SpecialJoinInfo
Relids clause_relids
Definition: relation.h:1652
Param * param
Definition: relation.h:1956
struct JoinPathExtraData JoinPathExtraData
int parallel_workers
Definition: relation.h:901
bool pseudoconstant
Definition: relation.h:1645
RelOptKind
Definition: relation.h:474
bool consider_param_startup
Definition: relation.h:497
struct PlannerInfo PlannerInfo
List * resultRelations
Definition: relation.h:108
ParamPathInfo * param_info
Definition: relation.h:897
struct EquivalenceMember EquivalenceMember
Index ec_sortref
Definition: relation.h:723
Definition: nodes.h:508
Oid * sortopfamily
Definition: relation.h:603
struct SubqueryScanPath SubqueryScanPath
List * partial_pathlist
Definition: relation.h:506
Oid reltablespace
Definition: relation.h:589
Relids left_relids
Definition: relation.h:1664
List * join_rel_list
Definition: relation.h:212
bool ec_below_outer_join
Definition: relation.h:721
uint32 flags
Definition: relation.h:1100
bool hasNonSerial
Definition: relation.h:61
uint32 BlockNumber
Definition: block.h:31
EquivalenceClass * right_ec
Definition: relation.h:1686
List * cheapest_parameterized_paths
Definition: relation.h:510
List * minmax_aggs
Definition: relation.h:280
bool single_copy
Definition: relation.h:1203
bool hypothetical
Definition: relation.h:623
Index baserestrict_min_security
Definition: relation.h:547
UniquePathMethod umethod
Definition: relation.h:1189
struct WindowAggPath WindowAggPath
Path * subpath
Definition: relation.h:1163
List * indexclauses
Definition: relation.h:973
NodeTag type
Definition: relation.h:485
double Selectivity
Definition: nodes.h:631
NodeTag type
Definition: relation.h:1931
Index ec_max_security
Definition: relation.h:725
bool hasNonPartial
Definition: relation.h:60
bool useridiscurrent
Definition: relation.h:538
AggSplit aggsplit
Definition: relation.h:1374
bool immediate
Definition: relation.h:622
QualCost transCost
Definition: relation.h:62
struct ProjectSetPath ProjectSetPath
Selectivity bitmapselectivity
Definition: relation.h:1016
double tuples
Definition: relation.h:594
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: relation.h:1402
UpperRelationKind
Definition: relation.h:71
struct ResultPath ResultPath
AttrNumber * grouping_map
Definition: relation.h:279
List * fkey_list
Definition: relation.h:255
int tree_height
Definition: relation.h:595
bool hasRecursion
Definition: relation.h:300
double numGroups
Definition: relation.h:1375
double numGroups
Definition: relation.h:1432
List * mergeopfamilies
Definition: relation.h:1682
List * translated_vars
Definition: relation.h:1893
SetOpStrategy
Definition: nodes.h:778
Cost inner_rescan_run_cost
Definition: relation.h:2079
Oid parent_reltype
Definition: relation.h:1874
Relids syn_lefthand
Definition: relation.h:1809
List * rowMarks
Definition: relation.h:1455
int pk_strategy
Definition: relation.h:793
List * winpathkeys
Definition: relation.h:1417
struct PlaceHolderVar PlaceHolderVar
Cost startup
Definition: relation.h:45
double allvisfrac
Definition: relation.h:530
Relids outer_relids
Definition: relation.h:1658
signed int int32
Definition: c.h:253
List * bitmapquals
Definition: relation.h:1015
Selectivity norm_selec
Definition: relation.h:1675
Path path
Definition: relation.h:1118
List * custom_private
Definition: relation.h:1103
JoinType
Definition: nodes.h:665
struct PlannerGlobal PlannerGlobal
WindowClause * winclause
Definition: relation.h:1416
struct RelOptInfo ** simple_rel_array
Definition: relation.h:176
List * bitmapquals
Definition: relation.h:1028
List * multiexpr_params
Definition: relation.h:229
bool unique
Definition: relation.h:621
BlockNumber pages
Definition: relation.h:593
NodeTag pathtype
Definition: relation.h:892
Relids syn_righthand
Definition: relation.h:1810
List * subpaths
Definition: relation.h:1119
PlannerInfo * subroot
Definition: relation.h:531
NodeTag type
Definition: relation.h:789
SetOpCmd cmd
Definition: relation.h:1427
bool dependsOnRole
Definition: relation.h:124
struct AggPath AggPath
bool consider_startup
Definition: relation.h:496
Definition: dynahash.c:193
struct MaterialPath MaterialPath
Relids lateral_relids
Definition: relation.h:515
Cost per_tuple
Definition: relation.h:46
const struct CustomPathMethods * methods
Definition: relation.h:1104
List * indexquals
Definition: relation.h:974
int wt_param_id
Definition: relation.h:303
double tuple_fraction
Definition: relation.h:286
Path * subpath
Definition: relation.h:1415
RelOptInfo * rel
Definition: relation.h:590
bool amoptionalkey
Definition: relation.h:627
SpecialJoinInfo * sjinfo
Definition: relation.h:2051
bool parallelModeNeeded
Definition: relation.h:128
Path path
Definition: relation.h:1150
struct AppendRelInfo AppendRelInfo
Relids phrels
Definition: relation.h:1741
Relids all_baserels
Definition: relation.h:193
bool pk_nulls_first
Definition: relation.h:794
Path * path
Definition: relation.h:1954
bool hasDeletedRTEs
Definition: relation.h:296
Expr * phexpr
Definition: relation.h:1740
Relids param_source_rels
Definition: relation.h:2053
NodeTag type
Definition: relation.h:851
double limit_tuples
Definition: relation.h:287
EquivalenceMember * left_em
Definition: relation.h:1687
Cost indextotalcost
Definition: relation.h:979
Cost startup_cost
Definition: relation.h:906
List * semi_rhs_exprs
Definition: relation.h:1818
NodeTag type
Definition: relation.h:823
Oid conpfeqop[INDEX_MAX_KEYS]
Definition: relation.h:655
bool semi_can_hash
Definition: relation.h:1816
bool hasLateralRTEs
Definition: relation.h:295
Path * subpath
Definition: relation.h:1488
struct PlannerParamItem PlannerParamItem
List * joinrestrictinfo
Definition: relation.h:1219
bool parallelModeOK
Definition: relation.h:126
EquivalenceClass * parent_ec
Definition: relation.h:1671
bool can_join
Definition: relation.h:1643
RTEKind
Definition: parsenodes.h:868
List * subroots
Definition: relation.h:1474
Bitmapset * rewindPlanIDs
Definition: relation.h:102
RelOptInfo * parent
Definition: relation.h:894
List * uniq_exprs
Definition: relation.h:1191
Path * bitmapqual
Definition: relation.h:1003
bool outerjoin_delayed
Definition: relation.h:1641
Path path
Definition: relation.h:1343
List * rollup_lists
Definition: relation.h:1391
List * ec_sources
Definition: relation.h:715
struct Path * cheapest_total_path
Definition: relation.h:508
Selectivity rightstartsel
Definition: relation.h:1719
List * curOuterParams
Definition: relation.h:308
struct SetOpPath SetOpPath
struct IndexOptInfo IndexOptInfo
Selectivity indexselectivity
Definition: relation.h:980
List * subplans
Definition: relation.h:98
bool amcanorderbyop
Definition: relation.h:626
List * joininfo
Definition: relation.h:549
struct GroupPath GroupPath
Relids ec_relids
Definition: relation.h:717
PlannerGlobal * glob
Definition: relation.h:154
bool outer_is_left
Definition: relation.h:1692
struct FdwRoutine * fdwroutine
Definition: relation.h:540
List * left_join_clauses
Definition: relation.h:236
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: relation.h:244
struct GroupingSetsPath GroupingSetsPath
List * subpaths
Definition: relation.h:1473
List * groupClause
Definition: relation.h:1376
Index * sortgrouprefs
Definition: relation.h:825
List * mergeclause_list
Definition: relation.h:2050
unsigned int uint32
Definition: c.h:265
AttrNumber flagColIdx
Definition: relation.h:1430
Relids relids
Definition: relation.h:490
Selectivity outer_selec
Definition: relation.h:1678
Path * subpath
Definition: relation.h:1202
struct TidPath TidPath
double total_table_pages
Definition: relation.h:284
struct LimitPath LimitPath
Selectivity bitmapselectivity
Definition: relation.h:1029
struct RecursiveUnionPath RecursiveUnionPath
int simple_rel_array_size
Definition: relation.h:177
int ncolumns
Definition: relation.h:598
bool amhasgetbitmap
Definition: relation.h:631
List * canon_pathkeys
Definition: relation.h:234
List * ppilist
Definition: relation.h:505
Path path
Definition: relation.h:1099
Index relid
Definition: relation.h:518
Bitmapset * Relids
Definition: relation.h:28
List * sort_pathkeys
Definition: relation.h:262
RangeTblEntry ** simple_rte_array
Definition: relation.h:185
struct PlannerInfo * parent_root
Definition: relation.h:158
EquivalenceMember * right_em
Definition: relation.h:1688
Relids lateral_referencers
Definition: relation.h:526
Expr * clause
Definition: relation.h:1637
int numOrderedAggs
Definition: relation.h:59
Path * subpath
Definition: relation.h:1454
struct EquivalenceClass * eclass[INDEX_MAX_KEYS]
Definition: relation.h:662
Oid serverid
Definition: relation.h:536
List * ec_opfamilies
Definition: relation.h:712
List * exprs
Definition: relation.h:824
struct ParamPathInfo ParamPathInfo
struct Path Path
List * window_pathkeys
Definition: relation.h:260
List * indrestrictinfo
Definition: relation.h:615
Relids direct_lateral_relids
Definition: relation.h:514
Path * outerjoinpath
Definition: relation.h:1216
List * invalItems
Definition: relation.h:112
NodeTag type
Definition: relation.h:150
struct MinMaxAggInfo MinMaxAggInfo
Relids nullable_relids
Definition: relation.h:1661
bool delay_upper_joins
Definition: relation.h:1813
struct QualCost QualCost
List * rollup_groupclauses
Definition: relation.h:1390
List * indexorderbys
Definition: relation.h:976
AttrNumber conkey[INDEX_MAX_KEYS]
Definition: relation.h:653
int rel_parallel_workers
Definition: relation.h:533
List * groupClause
Definition: relation.h:1345
List * append_rel_list
Definition: relation.h:249
Index lastPHId
Definition: relation.h:116
List * cte_plan_ids
Definition: relation.h:227
List * mmaggregates
Definition: relation.h:1401
Relids ph_lateral
Definition: relation.h:1936
Relids em_relids
Definition: relation.h:763
List * tidquals
Definition: relation.h:1042
List * restrictlist
Definition: relation.h:2049
Path * subpath
Definition: relation.h:1344
unsigned int Index
Definition: c.h:362
struct ForeignPath ForeignPath
RTEKind rtekind
Definition: relation.h:520
List * indexlist
Definition: relation.h:527
List * init_plans
Definition: relation.h:225
List * in_operators
Definition: relation.h:1190
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct MergeScanSelCache MergeScanSelCache
struct RestrictInfo RestrictInfo
double rows
Definition: relation.h:493
bool hasPseudoConstantQuals
Definition: relation.h:298
bool amhasgettuple
Definition: relation.h:630
Cost finalCost
Definition: relation.h:63
List * distinct_pathkeys
Definition: relation.h:261
bool is_pushed_down
Definition: relation.h:1639
void * fdw_private
Definition: relation.h:541
Cost total_cost
Definition: relation.h:907
NodeTag type
Definition: relation.h:586
Selectivity left_bucketsize
Definition: relation.h:1698
int firstFlag
Definition: relation.h:1431
double outer_skip_rows
Definition: relation.h:2084
List * pathkeys
Definition: relation.h:909
struct GatherPath GatherPath
Relids right_relids
Definition: relation.h:1665
BlockNumber pages
Definition: relation.h:528
Path path
Definition: relation.h:1212
ParamListInfo boundParams
Definition: relation.h:96
struct AggClauseCosts AggClauseCosts
Expr * target
Definition: relation.h:1952
List * eq_classes
Definition: relation.h:232
List ** join_rel_level
Definition: relation.h:222
NodeTag type
Definition: relation.h:94
JoinPath NestPath
Definition: relation.h:1232
Path * subpath
Definition: relation.h:1316
double rows
Definition: relation.h:905
bool parallel_safe
Definition: relation.h:900
List * lateral_vars
Definition: relation.h:525
bool hasInheritedTarget
Definition: relation.h:292
List * quals
Definition: relation.h:1151
JoinType jointype
Definition: relation.h:1811
EquivalenceClass * pk_eclass
Definition: relation.h:791
Bitmapset * outer_params
Definition: relation.h:167
List * ppi_clauses
Definition: relation.h:855
struct Path * non_recursive_path
Definition: relation.h:304
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:353
Oid hashjoinoperator
Definition: relation.h:1695
NodeTag type
Definition: relation.h:1635
QualCost cost
Definition: relation.h:826
AggSplit
Definition: nodes.h:748
bool ec_has_volatile
Definition: relation.h:720
List * relationOids
Definition: relation.h:110
struct HashPath HashPath
List * subroots
Definition: relation.h:100
bool amsearcharray
Definition: relation.h:628
struct HTAB * join_rel_hash
Definition: relation.h:213
CostSelector
Definition: relation.h:34
struct JoinPath JoinPath
Index qual_security_level
Definition: relation.h:289
bool consider_parallel
Definition: relation.h:498
List * innersortkeys
Definition: relation.h:1267
Path * subpath
Definition: relation.h:1372
Oid * opcintype
Definition: relation.h:602
struct EquivalenceClass EquivalenceClass
Index query_level
Definition: relation.h:156
Oid pk_opfamily
Definition: relation.h:792
struct JoinCostWorkspace JoinCostWorkspace
struct SortPath SortPath
double ppi_rows
Definition: relation.h:854
Path path
Definition: relation.h:1487
Path path
Definition: relation.h:1041
Oid child_reltype
Definition: relation.h:1875
Oid * opfamily
Definition: relation.h:601
List * withCheckOptionLists
Definition: relation.h:1475
List * indexqualcols
Definition: relation.h:975
List * finalrtable
Definition: relation.h:104
int width
Definition: relation.h:827
AggStrategy
Definition: nodes.h:727
Index phlevelsup
Definition: relation.h:1743
Index lastRowMarkId
Definition: relation.h:118
AttrNumber max_attr
Definition: relation.h:522
Selectivity match_count
Definition: relation.h:2033
Selectivity right_bucketsize
Definition: relation.h:1699
EquivalenceClass * left_ec
Definition: relation.h:1685
Relids nullable_baserels
Definition: relation.h:201
struct MergeAppendPath MergeAppendPath
List * fdw_private
Definition: relation.h:1073
SetOpCmd
Definition: nodes.h:770
JoinType jointype
Definition: relation.h:1214
List * semi_operators
Definition: relation.h:1817
ScanDirection indexscandir
Definition: relation.h:978
CmdType operation
Definition: relation.h:1469
List * placeholder_list
Definition: relation.h:253
List * resultRelations
Definition: relation.h:1472
int nParamExec
Definition: relation.h:114
Size transitionSpace
Definition: relation.h:64
struct BitmapHeapPath BitmapHeapPath
bool hasHavingQual
Definition: relation.h:297
struct PathKey PathKey
JoinPath jpath
Definition: relation.h:1264
NodeTag type
Definition: relation.h:710
bool parallel_aware
Definition: relation.h:899
int * indexkeys
Definition: relation.h:599
List * path_hashclauses
Definition: relation.h:1283
struct ProjectionPath ProjectionPath
UniquePathMethod
Definition: relation.h:1178
struct UpperUniquePath UpperUniquePath
List * initial_rels
Definition: relation.h:264
List * pathlist
Definition: relation.h:504
List * subpaths
Definition: relation.h:1137
Relids ppi_req_outer
Definition: relation.h:853
MemoryContext planner_cxt
Definition: relation.h:282
struct MergePath MergePath
List * right_join_clauses
Definition: relation.h:240
Oid indexoid
Definition: relation.h:588
Index child_relid
Definition: relation.h:1866
bool * canreturn
Definition: relation.h:606
bool amsearchnulls
Definition: relation.h:629
Oid parent_reloid
Definition: relation.h:1900
void(* amcostestimate)()
Definition: relation.h:634
bool * nulls_first
Definition: relation.h:605
Path * subpath
Definition: relation.h:1304
Path path
Definition: relation.h:1201
Index parent_relid
Definition: relation.h:1865
bool * reverse_sort
Definition: relation.h:604
double inner_skip_rows
Definition: relation.h:2085
List * processed_tlist
Definition: relation.h:276
List * indpred
Definition: relation.h:611
int32 * attr_widths
Definition: relation.h:524
Node * limitCount
Definition: relation.h:1490
List * finalrowmarks
Definition: relation.h:106
Definition: pg_list.h:45
AttrNumber confkey[INDEX_MAX_KEYS]
Definition: relation.h:654
Path path
Definition: relation.h:1329
struct PathTarget * reltarget
Definition: relation.h:501
Relids min_lefthand
Definition: relation.h:1807
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: relation.h:546
List * rinfos[INDEX_MAX_KEYS]
Definition: relation.h:664
List * subplan_params
Definition: relation.h:532
Path path
Definition: relation.h:1425
NodeTag type
Definition: relation.h:1948
Path path
Definition: relation.h:1187
CmdType
Definition: nodes.h:641
Path path
Definition: relation.h:1371
struct RelOptInfo RelOptInfo
Definition: relation.h:888
double limit_tuples
Definition: relation.h:1138
struct EquivalenceClass * ec_merged
Definition: relation.h:726
Selectivity rightendsel
Definition: relation.h:1720
bool amcanparallel
Definition: relation.h:632
double Cost
Definition: nodes.h:632
List * scansel_cache
Definition: relation.h:1689
Selectivity leftstartsel
Definition: relation.h:1717
List * ec_members
Definition: relation.h:714
List * indexprs
Definition: relation.h:610
bool transientPlan
Definition: relation.h:122
struct PathTarget * upper_targets[UPPERREL_FINAL+1]
Definition: relation.h:270
Path * subpath
Definition: relation.h:1188
PlannerInfo * subroot
Definition: relation.h:1953
struct BitmapAndPath BitmapAndPath
List * upper_rels[UPPERREL_FINAL+1]
Definition: relation.h:267
AttrNumber min_attr
Definition: relation.h:521