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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) 1996-2018, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/nodes/relation.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef RELATION_H
15 #define RELATION_H
16 
17 #include "access/sdir.h"
18 #include "lib/stringinfo.h"
19 #include "nodes/params.h"
20 #include "nodes/parsenodes.h"
21 #include "storage/block.h"
22 
23 
24 /*
25  * Relids
26  * Set of relation identifiers (indexes into the rangetable).
27  */
28 typedef Bitmapset *Relids;
29 
30 /*
31  * When looking for a "cheapest path", this enum specifies whether we want
32  * cheapest startup cost or cheapest total cost.
33  */
34 typedef enum CostSelector
35 {
37 } CostSelector;
38 
39 /*
40  * The cost estimate produced by cost_qual_eval() includes both a one-time
41  * (startup) cost, and a per-tuple cost.
42  */
43 typedef struct QualCost
44 {
45  Cost startup; /* one-time cost */
46  Cost per_tuple; /* per-evaluation cost */
47 } QualCost;
48 
49 /*
50  * Costing aggregate function execution requires these statistics about
51  * the aggregates to be executed by a given Agg node. Note that the costs
52  * include the execution costs of the aggregates' argument expressions as
53  * well as the aggregate functions themselves. Also, the fields must be
54  * defined so that initializing the struct to zeroes with memset is correct.
55  */
56 typedef struct AggClauseCosts
57 {
58  int numAggs; /* total number of aggregate functions */
59  int numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
60  bool hasNonPartial; /* does any agg not support partial mode? */
61  bool hasNonSerial; /* is any partial agg non-serializable? */
62  QualCost transCost; /* total per-input-row execution costs */
63  Cost finalCost; /* total per-aggregated-row costs */
64  Size transitionSpace; /* space for pass-by-ref transition data */
66 
67 /*
68  * This enum identifies the different types of "upper" (post-scan/join)
69  * relations that we might deal with during planning.
70  */
71 typedef enum UpperRelationKind
72 {
73  UPPERREL_SETOP, /* result of UNION/INTERSECT/EXCEPT, if any */
74  UPPERREL_GROUP_AGG, /* result of grouping/aggregation, if any */
75  UPPERREL_WINDOW, /* result of window functions, if any */
76  UPPERREL_DISTINCT, /* result of "SELECT DISTINCT", if any */
77  UPPERREL_ORDERED, /* result of ORDER BY, if any */
78  UPPERREL_FINAL /* result of any remaining top-level actions */
79  /* NB: UPPERREL_FINAL must be last enum entry; it's used to size arrays */
81 
82 
83 /*----------
84  * PlannerGlobal
85  * Global information for planning/optimization
86  *
87  * PlannerGlobal holds state for an entire planner invocation; this state
88  * is shared across all levels of sub-Queries that exist in the command being
89  * planned.
90  *----------
91  */
92 typedef struct PlannerGlobal
93 {
95 
96  ParamListInfo boundParams; /* Param values provided to planner() */
97 
98  List *subplans; /* Plans for SubPlan nodes */
99 
100  List *subroots; /* PlannerInfos for SubPlan nodes */
101 
102  Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
103 
104  List *finalrtable; /* "flat" rangetable for executor */
105 
106  List *finalrowmarks; /* "flat" list of PlanRowMarks */
107 
108  List *resultRelations; /* "flat" list of integer RT indexes */
109 
110  List *nonleafResultRelations; /* "flat" list of integer RT indexes */
111  List *rootResultRelations; /* "flat" list of integer RT indexes */
112 
113  List *relationOids; /* OIDs of relations the plan depends on */
114 
115  List *invalItems; /* other dependencies, as PlanInvalItems */
116 
117  List *paramExecTypes; /* type OIDs for PARAM_EXEC Params */
118 
119  Index lastPHId; /* highest PlaceHolderVar ID assigned */
120 
121  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
122 
123  int lastPlanNodeId; /* highest plan node ID assigned */
124 
125  bool transientPlan; /* redo plan when TransactionXmin changes? */
126 
127  bool dependsOnRole; /* is plan specific to current role? */
128 
129  bool parallelModeOK; /* parallel mode potentially OK? */
130 
131  bool parallelModeNeeded; /* parallel mode actually required? */
132 
133  char maxParallelHazard; /* worst PROPARALLEL hazard level */
134 } PlannerGlobal;
135 
136 /* macro for fetching the Plan associated with a SubPlan node */
137 #define planner_subplan_get_plan(root, subplan) \
138  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
139 
140 
141 /*----------
142  * PlannerInfo
143  * Per-query information for planning/optimization
144  *
145  * This struct is conventionally called "root" in all the planner routines.
146  * It holds links to all of the planner's working state, in addition to the
147  * original Query. Note that at present the planner extensively modifies
148  * the passed-in Query data structure; someday that should stop.
149  *----------
150  */
151 typedef struct PlannerInfo
152 {
154 
155  Query *parse; /* the Query being planned */
156 
157  PlannerGlobal *glob; /* global info for current planner run */
158 
159  Index query_level; /* 1 at the outermost Query */
160 
161  struct PlannerInfo *parent_root; /* NULL at outermost Query */
162 
163  /*
164  * plan_params contains the expressions that this query level needs to
165  * make available to a lower query level that is currently being planned.
166  * outer_params contains the paramIds of PARAM_EXEC Params that outer
167  * query levels will make available to this query level.
168  */
169  List *plan_params; /* list of PlannerParamItems, see below */
171 
172  /*
173  * simple_rel_array holds pointers to "base rels" and "other rels" (see
174  * comments for RelOptInfo for more info). It is indexed by rangetable
175  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
176  * does not correspond to a base relation, such as a join RTE or an
177  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
178  */
179  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
180  int simple_rel_array_size; /* allocated size of array */
181 
182  /*
183  * simple_rte_array is the same length as simple_rel_array and holds
184  * pointers to the associated rangetable entries. This lets us avoid
185  * rt_fetch(), which can be a bit slow once large inheritance sets have
186  * been expanded.
187  */
188  RangeTblEntry **simple_rte_array; /* rangetable as an array */
189 
190  /*
191  * all_baserels is a Relids set of all base relids (but not "other"
192  * relids) in the query; that is, the Relids identifier of the final join
193  * we need to form. This is computed in make_one_rel, just before we
194  * start making Paths.
195  */
197 
198  /*
199  * nullable_baserels is a Relids set of base relids that are nullable by
200  * some outer join in the jointree; these are rels that are potentially
201  * nullable below the WHERE clause, SELECT targetlist, etc. This is
202  * computed in deconstruct_jointree.
203  */
205 
206  /*
207  * join_rel_list is a list of all join-relation RelOptInfos we have
208  * considered in this planning run. For small problems we just scan the
209  * list to do lookups, but when there are many join relations we build a
210  * hash table for faster lookups. The hash table is present and valid
211  * when join_rel_hash is not NULL. Note that we still maintain the list
212  * even when using the hash table for lookups; this simplifies life for
213  * GEQO.
214  */
215  List *join_rel_list; /* list of join-relation RelOptInfos */
216  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
217 
218  /*
219  * When doing a dynamic-programming-style join search, join_rel_level[k]
220  * is a list of all join-relation RelOptInfos of level k, and
221  * join_cur_level is the current level. New join-relation RelOptInfos are
222  * automatically added to the join_rel_level[join_cur_level] list.
223  * join_rel_level is NULL if not in use.
224  */
225  List **join_rel_level; /* lists of join-relation RelOptInfos */
226  int join_cur_level; /* index of list being extended */
227 
228  List *init_plans; /* init SubPlans for query */
229 
230  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
231 
232  List *multiexpr_params; /* List of Lists of Params for MULTIEXPR
233  * subquery outputs */
234 
235  List *eq_classes; /* list of active EquivalenceClasses */
236 
237  List *canon_pathkeys; /* list of "canonical" PathKeys */
238 
239  List *left_join_clauses; /* list of RestrictInfos for mergejoinable
240  * outer join clauses w/nonnullable var on
241  * left */
242 
243  List *right_join_clauses; /* list of RestrictInfos for mergejoinable
244  * outer join clauses w/nonnullable var on
245  * right */
246 
247  List *full_join_clauses; /* list of RestrictInfos for mergejoinable
248  * full join clauses */
249 
250  List *join_info_list; /* list of SpecialJoinInfos */
251 
252  List *append_rel_list; /* list of AppendRelInfos */
253 
254  List *pcinfo_list; /* list of PartitionedChildRelInfos */
255 
256  List *rowMarks; /* list of PlanRowMarks */
257 
258  List *placeholder_list; /* list of PlaceHolderInfos */
259 
260  List *fkey_list; /* list of ForeignKeyOptInfos */
261 
262  List *query_pathkeys; /* desired pathkeys for query_planner() */
263 
264  List *group_pathkeys; /* groupClause pathkeys, if any */
265  List *window_pathkeys; /* pathkeys of bottom window, if any */
266  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
267  List *sort_pathkeys; /* sortClause pathkeys, if any */
268 
269  List *part_schemes; /* Canonicalised partition schemes used in the
270  * query. */
271 
272  List *initial_rels; /* RelOptInfos we are now trying to join */
273 
274  /* Use fetch_upper_rel() to get any particular upper rel */
275  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
276 
277  /* Result tlists chosen by grouping_planner for upper-stage processing */
278  struct PathTarget *upper_targets[UPPERREL_FINAL + 1];
279 
280  /*
281  * grouping_planner passes back its final processed targetlist here, for
282  * use in relabeling the topmost tlist of the finished Plan.
283  */
285 
286  /* Fields filled during create_plan() for use in setrefs.c */
287  AttrNumber *grouping_map; /* for GroupingFunc fixup */
288  List *minmax_aggs; /* List of MinMaxAggInfos */
289 
290  MemoryContext planner_cxt; /* context holding PlannerInfo */
291 
292  double total_table_pages; /* # of pages in all tables of query */
293 
294  double tuple_fraction; /* tuple_fraction passed to query_planner */
295  double limit_tuples; /* limit_tuples passed to query_planner */
296 
297  Index qual_security_level; /* minimum security_level for quals */
298  /* Note: qual_security_level is zero if there are no securityQuals */
299 
300  bool hasInheritedTarget; /* true if parse->resultRelation is an
301  * inheritance child rel */
302  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
303  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
304  bool hasDeletedRTEs; /* true if any RTE was deleted from jointree */
305  bool hasHavingQual; /* true if havingQual was non-null */
306  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
307  * pseudoconstant = true */
308  bool hasRecursion; /* true if planning a recursive WITH item */
309 
310  /* These fields are used only when hasRecursion is true: */
311  int wt_param_id; /* PARAM_EXEC ID for the work table */
312  struct Path *non_recursive_path; /* a path for non-recursive term */
313 
314  /* These fields are workspace for createplan.c */
315  Relids curOuterRels; /* outer rels above current node */
316  List *curOuterParams; /* not-yet-assigned NestLoopParams */
317 
318  /* optional private data for join_search_hook, e.g., GEQO */
320 } PlannerInfo;
321 
322 
323 /*
324  * In places where it's known that simple_rte_array[] must have been prepared
325  * already, we just index into it to fetch RTEs. In code that might be
326  * executed before or after entering query_planner(), use this macro.
327  */
328 #define planner_rt_fetch(rti, root) \
329  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
330  rt_fetch(rti, (root)->parse->rtable))
331 
332 /*
333  * If multiple relations are partitioned the same way, all such partitions
334  * will have a pointer to the same PartitionScheme. A list of PartitionScheme
335  * objects is attached to the PlannerInfo. By design, the partition scheme
336  * incorporates only the general properties of the partition method (LIST vs.
337  * RANGE, number of partitioning columns and the type information for each)
338  * and not the specific bounds.
339  *
340  * We store the opclass-declared input data types instead of the partition key
341  * datatypes since the former rather than the latter are used to compare
342  * partition bounds. Since partition key data types and the opclass declared
343  * input data types are expected to be binary compatible (per ResolveOpClass),
344  * both of those should have same byval and length properties.
345  */
346 typedef struct PartitionSchemeData
347 {
348  char strategy; /* partition strategy */
349  int16 partnatts; /* number of partition attributes */
350  Oid *partopfamily; /* OIDs of operator families */
351  Oid *partopcintype; /* OIDs of opclass declared input data types */
352  Oid *parttypcoll; /* OIDs of collations of partition keys. */
353 
354  /* Cached information about partition key data types. */
358 
360 
361 /*----------
362  * RelOptInfo
363  * Per-relation information for planning/optimization
364  *
365  * For planning purposes, a "base rel" is either a plain relation (a table)
366  * or the output of a sub-SELECT or function that appears in the range table.
367  * In either case it is uniquely identified by an RT index. A "joinrel"
368  * is the joining of two or more base rels. A joinrel is identified by
369  * the set of RT indexes for its component baserels. We create RelOptInfo
370  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
371  * simple_rel_array and join_rel_list respectively.
372  *
373  * Note that there is only one joinrel for any given set of component
374  * baserels, no matter what order we assemble them in; so an unordered
375  * set is the right datatype to identify it with.
376  *
377  * We also have "other rels", which are like base rels in that they refer to
378  * single RT indexes; but they are not part of the join tree, and are given
379  * a different RelOptKind to identify them.
380  * Currently the only kind of otherrels are those made for member relations
381  * of an "append relation", that is an inheritance set or UNION ALL subquery.
382  * An append relation has a parent RTE that is a base rel, which represents
383  * the entire append relation. The member RTEs are otherrels. The parent
384  * is present in the query join tree but the members are not. The member
385  * RTEs and otherrels are used to plan the scans of the individual tables or
386  * subqueries of the append set; then the parent baserel is given Append
387  * and/or MergeAppend paths comprising the best paths for the individual
388  * member rels. (See comments for AppendRelInfo for more information.)
389  *
390  * At one time we also made otherrels to represent join RTEs, for use in
391  * handling join alias Vars. Currently this is not needed because all join
392  * alias Vars are expanded to non-aliased form during preprocess_expression.
393  *
394  * We also have relations representing joins between child relations of
395  * different partitioned tables. These relations are not added to
396  * join_rel_level lists as they are not joined directly by the dynamic
397  * programming algorithm.
398  *
399  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
400  * that describe post-scan/join processing steps, such as aggregation.
401  * Many of the fields in these RelOptInfos are meaningless, but their Path
402  * fields always hold Paths showing ways to do that processing step.
403  *
404  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
405  * that we have proven we don't need to join after all.
406  *
407  * Parts of this data structure are specific to various scan and join
408  * mechanisms. It didn't seem worth creating new node types for them.
409  *
410  * relids - Set of base-relation identifiers; it is a base relation
411  * if there is just one, a join relation if more than one
412  * rows - estimated number of tuples in the relation after restriction
413  * clauses have been applied (ie, output rows of a plan for it)
414  * consider_startup - true if there is any value in keeping plain paths for
415  * this rel on the basis of having cheap startup cost
416  * consider_param_startup - the same for parameterized paths
417  * reltarget - Default Path output tlist for this rel; normally contains
418  * Var and PlaceHolderVar nodes for the values we need to
419  * output from this relation.
420  * List is in no particular order, but all rels of an
421  * appendrel set must use corresponding orders.
422  * NOTE: in an appendrel child relation, may contain
423  * arbitrary expressions pulled up from a subquery!
424  * pathlist - List of Path nodes, one for each potentially useful
425  * method of generating the relation
426  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
427  * cheapest_startup_path - the pathlist member with lowest startup cost
428  * (regardless of ordering) among the unparameterized paths;
429  * or NULL if there is no unparameterized path
430  * cheapest_total_path - the pathlist member with lowest total cost
431  * (regardless of ordering) among the unparameterized paths;
432  * or if there is no unparameterized path, the path with lowest
433  * total cost among the paths with minimum parameterization
434  * cheapest_unique_path - for caching cheapest path to produce unique
435  * (no duplicates) output from relation; NULL if not yet requested
436  * cheapest_parameterized_paths - best paths for their parameterizations;
437  * always includes cheapest_total_path, even if that's unparameterized
438  * direct_lateral_relids - rels this rel has direct LATERAL references to
439  * lateral_relids - required outer rels for LATERAL, as a Relids set
440  * (includes both direct and indirect lateral references)
441  *
442  * If the relation is a base relation it will have these fields set:
443  *
444  * relid - RTE index (this is redundant with the relids field, but
445  * is provided for convenience of access)
446  * rtekind - copy of RTE's rtekind field
447  * min_attr, max_attr - range of valid AttrNumbers for rel
448  * attr_needed - array of bitmapsets indicating the highest joinrel
449  * in which each attribute is needed; if bit 0 is set then
450  * the attribute is needed as part of final targetlist
451  * attr_widths - cache space for per-attribute width estimates;
452  * zero means not computed yet
453  * lateral_vars - lateral cross-references of rel, if any (list of
454  * Vars and PlaceHolderVars)
455  * lateral_referencers - relids of rels that reference this one laterally
456  * (includes both direct and indirect lateral references)
457  * indexlist - list of IndexOptInfo nodes for relation's indexes
458  * (always NIL if it's not a table)
459  * pages - number of disk pages in relation (zero if not a table)
460  * tuples - number of tuples in relation (not considering restrictions)
461  * allvisfrac - fraction of disk pages that are marked all-visible
462  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
463  * subplan_params - list of PlannerParamItems to be passed to subquery
464  *
465  * Note: for a subquery, tuples and subroot are not set immediately
466  * upon creation of the RelOptInfo object; they are filled in when
467  * set_subquery_pathlist processes the object.
468  *
469  * For otherrels that are appendrel members, these fields are filled
470  * in just as for a baserel, except we don't bother with lateral_vars.
471  *
472  * If the relation is either a foreign table or a join of foreign tables that
473  * all belong to the same foreign server and are assigned to the same user to
474  * check access permissions as (cf checkAsUser), these fields will be set:
475  *
476  * serverid - OID of foreign server, if foreign table (else InvalidOid)
477  * userid - OID of user to check access as (InvalidOid means current user)
478  * useridiscurrent - we've assumed that userid equals current user
479  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
480  * fdw_private - private state for FDW, if foreign table (else NULL)
481  *
482  * Two fields are used to cache knowledge acquired during the join search
483  * about whether this rel is provably unique when being joined to given other
484  * relation(s), ie, it can have at most one row matching any given row from
485  * that join relation. Currently we only attempt such proofs, and thus only
486  * populate these fields, for base rels; but someday they might be used for
487  * join rels too:
488  *
489  * unique_for_rels - list of Relid sets, each one being a set of other
490  * rels for which this one has been proven unique
491  * non_unique_for_rels - list of Relid sets, each one being a set of
492  * other rels for which we have tried and failed to prove
493  * this one unique
494  *
495  * The presence of the following fields depends on the restrictions
496  * and joins that the relation participates in:
497  *
498  * baserestrictinfo - List of RestrictInfo nodes, containing info about
499  * each non-join qualification clause in which this relation
500  * participates (only used for base rels)
501  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
502  * clauses at a single tuple (only used for base rels)
503  * baserestrict_min_security - Smallest security_level found among
504  * clauses in baserestrictinfo
505  * joininfo - List of RestrictInfo nodes, containing info about each
506  * join clause in which this relation participates (but
507  * note this excludes clauses that might be derivable from
508  * EquivalenceClasses)
509  * has_eclass_joins - flag that EquivalenceClass joins are possible
510  *
511  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
512  * base rels, because for a join rel the set of clauses that are treated as
513  * restrict clauses varies depending on which sub-relations we choose to join.
514  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
515  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
516  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
517  * and should not be processed again at the level of {1 2 3}.) Therefore,
518  * the restrictinfo list in the join case appears in individual JoinPaths
519  * (field joinrestrictinfo), not in the parent relation. But it's OK for
520  * the RelOptInfo to store the joininfo list, because that is the same
521  * for a given rel no matter how we form it.
522  *
523  * We store baserestrictcost in the RelOptInfo (for base relations) because
524  * we know we will need it at least once (to price the sequential scan)
525  * and may need it multiple times to price index scans.
526  *
527  * If the relation is partitioned, these fields will be set:
528  *
529  * part_scheme - Partitioning scheme of the relation
530  * boundinfo - Partition bounds
531  * nparts - Number of partitions
532  * part_rels - RelOptInfos for each partition
533  * partexprs, nullable_partexprs - Partition key expressions
534  *
535  * Note: A base relation always has only one set of partition keys, but a join
536  * relation may have as many sets of partition keys as the number of relations
537  * being joined. partexprs and nullable_partexprs are arrays containing
538  * part_scheme->partnatts elements each. Each of these elements is a list of
539  * partition key expressions. For a base relation each list in partexprs
540  * contains only one expression and nullable_partexprs is not populated. For a
541  * join relation, partexprs and nullable_partexprs contain partition key
542  * expressions from non-nullable and nullable relations resp. Lists at any
543  * given position in those arrays together contain as many elements as the
544  * number of joining relations.
545  *----------
546  */
547 typedef enum RelOptKind
548 {
555 } RelOptKind;
556 
557 /*
558  * Is the given relation a simple relation i.e a base or "other" member
559  * relation?
560  */
561 #define IS_SIMPLE_REL(rel) \
562  ((rel)->reloptkind == RELOPT_BASEREL || \
563  (rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
564 
565 /* Is the given relation a join relation? */
566 #define IS_JOIN_REL(rel) \
567  ((rel)->reloptkind == RELOPT_JOINREL || \
568  (rel)->reloptkind == RELOPT_OTHER_JOINREL)
569 
570 /* Is the given relation an upper relation? */
571 #define IS_UPPER_REL(rel) ((rel)->reloptkind == RELOPT_UPPER_REL)
572 
573 /* Is the given relation an "other" relation? */
574 #define IS_OTHER_REL(rel) \
575  ((rel)->reloptkind == RELOPT_OTHER_MEMBER_REL || \
576  (rel)->reloptkind == RELOPT_OTHER_JOINREL)
577 
578 typedef struct RelOptInfo
579 {
581 
583 
584  /* all relations included in this RelOptInfo */
585  Relids relids; /* set of base relids (rangetable indexes) */
586 
587  /* size estimates generated by planner */
588  double rows; /* estimated number of result tuples */
589 
590  /* per-relation planner control flags */
591  bool consider_startup; /* keep cheap-startup-cost paths? */
592  bool consider_param_startup; /* ditto, for parameterized paths? */
593  bool consider_parallel; /* consider parallel paths? */
594 
595  /* default result targetlist for Paths scanning this relation */
596  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
597 
598  /* materialization information */
599  List *pathlist; /* Path structures */
600  List *ppilist; /* ParamPathInfos used in pathlist */
601  List *partial_pathlist; /* partial Paths */
606 
607  /* parameterization information needed for both base rels and join rels */
608  /* (see also lateral_vars and lateral_referencers) */
609  Relids direct_lateral_relids; /* rels directly laterally referenced */
610  Relids lateral_relids; /* minimum parameterization of rel */
611 
612  /* information about a base rel (not set for join rels!) */
614  Oid reltablespace; /* containing tablespace */
615  RTEKind rtekind; /* RELATION, SUBQUERY, FUNCTION, etc */
616  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
617  AttrNumber max_attr; /* largest attrno of rel */
618  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
619  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
620  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
621  Relids lateral_referencers; /* rels that reference me laterally */
622  List *indexlist; /* list of IndexOptInfo */
623  List *statlist; /* list of StatisticExtInfo */
624  BlockNumber pages; /* size estimates derived from pg_class */
625  double tuples;
626  double allvisfrac;
627  PlannerInfo *subroot; /* if subquery */
628  List *subplan_params; /* if subquery */
629  int rel_parallel_workers; /* wanted number of parallel workers */
630 
631  /* Information about foreign tables and foreign joins */
632  Oid serverid; /* identifies server for the table or join */
633  Oid userid; /* identifies user to check access as */
634  bool useridiscurrent; /* join is only valid for current user */
635  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
637  void *fdw_private;
638 
639  /* cache space for remembering if we have proven this relation unique */
640  List *unique_for_rels; /* known unique for these other relid
641  * set(s) */
642  List *non_unique_for_rels; /* known not unique for these set(s) */
643 
644  /* used by various scans and joins: */
645  List *baserestrictinfo; /* RestrictInfo structures (if base rel) */
646  QualCost baserestrictcost; /* cost of evaluating the above */
647  Index baserestrict_min_security; /* min security_level found in
648  * baserestrictinfo */
649  List *joininfo; /* RestrictInfo structures for join clauses
650  * involving this rel */
651  bool has_eclass_joins; /* T means joininfo is incomplete */
652 
653  /* used by "other" relations */
654  Relids top_parent_relids; /* Relids of topmost parents */
655 
656  /* used for partitioned relations */
657  PartitionScheme part_scheme; /* Partitioning scheme. */
658  int nparts; /* number of partitions */
659  struct PartitionBoundInfoData *boundinfo; /* Partition bounds */
660  struct RelOptInfo **part_rels; /* Array of RelOptInfos of partitions,
661  * stored in the same order of bounds */
662  List **partexprs; /* Non-nullable partition key expressions. */
663  List **nullable_partexprs; /* Nullable partition key expressions. */
664 } RelOptInfo;
665 
666 /*
667  * Is given relation partitioned?
668  *
669  * It's not enough to test whether rel->part_scheme is set, because it might
670  * be that the basic partitioning properties of the input relations matched
671  * but the partition bounds did not.
672  *
673  * We treat dummy relations as unpartitioned. We could alternatively
674  * treat them as partitioned, but it's not clear whether that's a useful thing
675  * to do.
676  */
677 #define IS_PARTITIONED_REL(rel) \
678  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
679  (rel)->part_rels && !(IS_DUMMY_REL(rel)))
680 
681 /*
682  * Convenience macro to make sure that a partitioned relation has all the
683  * required members set.
684  */
685 #define REL_HAS_ALL_PART_PROPS(rel) \
686  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
687  (rel)->part_rels && (rel)->partexprs && (rel)->nullable_partexprs)
688 
689 /*
690  * IndexOptInfo
691  * Per-index information for planning/optimization
692  *
693  * indexkeys[], indexcollations[], opfamily[], and opcintype[]
694  * each have ncolumns entries.
695  *
696  * sortopfamily[], reverse_sort[], and nulls_first[] likewise have
697  * ncolumns entries, if the index is ordered; but if it is unordered,
698  * those pointers are NULL.
699  *
700  * Zeroes in the indexkeys[] array indicate index columns that are
701  * expressions; there is one element in indexprs for each such column.
702  *
703  * For an ordered index, reverse_sort[] and nulls_first[] describe the
704  * sort ordering of a forward indexscan; we can also consider a backward
705  * indexscan, which will generate the reverse ordering.
706  *
707  * The indexprs and indpred expressions have been run through
708  * prepqual.c and eval_const_expressions() for ease of matching to
709  * WHERE clauses. indpred is in implicit-AND form.
710  *
711  * indextlist is a TargetEntry list representing the index columns.
712  * It provides an equivalent base-relation Var for each simple column,
713  * and links to the matching indexprs element for each expression column.
714  *
715  * While most of these fields are filled when the IndexOptInfo is created
716  * (by plancat.c), indrestrictinfo and predOK are set later, in
717  * check_index_predicates().
718  */
719 typedef struct IndexOptInfo
720 {
722 
723  Oid indexoid; /* OID of the index relation */
724  Oid reltablespace; /* tablespace of index (not table) */
725  RelOptInfo *rel; /* back-link to index's table */
726 
727  /* index-size statistics (from pg_class and elsewhere) */
728  BlockNumber pages; /* number of disk pages in index */
729  double tuples; /* number of index tuples in index */
730  int tree_height; /* index tree height, or -1 if unknown */
731 
732  /* index descriptor information */
733  int ncolumns; /* number of columns in index */
734  int *indexkeys; /* column numbers of index's keys, or 0 */
735  Oid *indexcollations; /* OIDs of collations of index columns */
736  Oid *opfamily; /* OIDs of operator families for columns */
737  Oid *opcintype; /* OIDs of opclass declared input data types */
738  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
739  bool *reverse_sort; /* is sort order descending? */
740  bool *nulls_first; /* do NULLs come first in the sort order? */
741  bool *canreturn; /* which index cols can be returned in an
742  * index-only scan? */
743  Oid relam; /* OID of the access method (in pg_am) */
744 
745  List *indexprs; /* expressions for non-simple index columns */
746  List *indpred; /* predicate if a partial index, else NIL */
747 
748  List *indextlist; /* targetlist representing index columns */
749 
750  List *indrestrictinfo; /* parent relation's baserestrictinfo
751  * list, less any conditions implied by
752  * the index's predicate (unless it's a
753  * target rel, see comments in
754  * check_index_predicates()) */
755 
756  bool predOK; /* true if index predicate matches query */
757  bool unique; /* true if a unique index */
758  bool immediate; /* is uniqueness enforced immediately? */
759  bool hypothetical; /* true if index doesn't really exist */
760 
761  /* Remaining fields are copied from the index AM's API struct: */
762  bool amcanorderbyop; /* does AM support order by operator result? */
763  bool amoptionalkey; /* can query omit key for the first column? */
764  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
765  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
766  bool amhasgettuple; /* does AM have amgettuple interface? */
767  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
768  bool amcanparallel; /* does AM support parallel scan? */
769  /* Rather than include amapi.h here, we declare amcostestimate like this */
770  void (*amcostestimate) (); /* AM's cost estimator */
771 } IndexOptInfo;
772 
773 /*
774  * ForeignKeyOptInfo
775  * Per-foreign-key information for planning/optimization
776  *
777  * The per-FK-column arrays can be fixed-size because we allow at most
778  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
779  * nkeys valid entries.
780  */
781 typedef struct ForeignKeyOptInfo
782 {
784 
785  /* Basic data about the foreign key (fetched from catalogs): */
786  Index con_relid; /* RT index of the referencing table */
787  Index ref_relid; /* RT index of the referenced table */
788  int nkeys; /* number of columns in the foreign key */
789  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
790  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
791  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
792 
793  /* Derived info about whether FK's equality conditions match the query: */
794  int nmatched_ec; /* # of FK cols matched by ECs */
795  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
796  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
797  /* Pointer to eclass matching each column's condition, if there is one */
799  /* List of non-EC RestrictInfos matching each column's condition */
802 
803 /*
804  * StatisticExtInfo
805  * Information about extended statistics for planning/optimization
806  *
807  * Each pg_statistic_ext row is represented by one or more nodes of this
808  * type, or even zero if ANALYZE has not computed them.
809  */
810 typedef struct StatisticExtInfo
811 {
813 
814  Oid statOid; /* OID of the statistics row */
815  RelOptInfo *rel; /* back-link to statistic's table */
816  char kind; /* statistic kind of this entry */
817  Bitmapset *keys; /* attnums of the columns covered */
819 
820 /*
821  * EquivalenceClasses
822  *
823  * Whenever we can determine that a mergejoinable equality clause A = B is
824  * not delayed by any outer join, we create an EquivalenceClass containing
825  * the expressions A and B to record this knowledge. If we later find another
826  * equivalence B = C, we add C to the existing EquivalenceClass; this may
827  * require merging two existing EquivalenceClasses. At the end of the qual
828  * distribution process, we have sets of values that are known all transitively
829  * equal to each other, where "equal" is according to the rules of the btree
830  * operator family(s) shown in ec_opfamilies, as well as the collation shown
831  * by ec_collation. (We restrict an EC to contain only equalities whose
832  * operators belong to the same set of opfamilies. This could probably be
833  * relaxed, but for now it's not worth the trouble, since nearly all equality
834  * operators belong to only one btree opclass anyway. Similarly, we suppose
835  * that all or none of the input datatypes are collatable, so that a single
836  * collation value is sufficient.)
837  *
838  * We also use EquivalenceClasses as the base structure for PathKeys, letting
839  * us represent knowledge about different sort orderings being equivalent.
840  * Since every PathKey must reference an EquivalenceClass, we will end up
841  * with single-member EquivalenceClasses whenever a sort key expression has
842  * not been equivalenced to anything else. It is also possible that such an
843  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
844  * which is a case that can't arise otherwise since clauses containing
845  * volatile functions are never considered mergejoinable. We mark such
846  * EquivalenceClasses specially to prevent them from being merged with
847  * ordinary EquivalenceClasses. Also, for volatile expressions we have
848  * to be careful to match the EquivalenceClass to the correct targetlist
849  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
850  * So we record the SortGroupRef of the originating sort clause.
851  *
852  * We allow equality clauses appearing below the nullable side of an outer join
853  * to form EquivalenceClasses, but these have a slightly different meaning:
854  * the included values might be all NULL rather than all the same non-null
855  * values. See src/backend/optimizer/README for more on that point.
856  *
857  * NB: if ec_merged isn't NULL, this class has been merged into another, and
858  * should be ignored in favor of using the pointed-to class.
859  */
860 typedef struct EquivalenceClass
861 {
863 
864  List *ec_opfamilies; /* btree operator family OIDs */
865  Oid ec_collation; /* collation, if datatypes are collatable */
866  List *ec_members; /* list of EquivalenceMembers */
867  List *ec_sources; /* list of generating RestrictInfos */
868  List *ec_derives; /* list of derived RestrictInfos */
869  Relids ec_relids; /* all relids appearing in ec_members, except
870  * for child members (see below) */
871  bool ec_has_const; /* any pseudoconstants in ec_members? */
872  bool ec_has_volatile; /* the (sole) member is a volatile expr */
873  bool ec_below_outer_join; /* equivalence applies below an OJ */
874  bool ec_broken; /* failed to generate needed clauses? */
875  Index ec_sortref; /* originating sortclause label, or 0 */
876  Index ec_min_security; /* minimum security_level in ec_sources */
877  Index ec_max_security; /* maximum security_level in ec_sources */
878  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
880 
881 /*
882  * If an EC contains a const and isn't below-outer-join, any PathKey depending
883  * on it must be redundant, since there's only one possible value of the key.
884  */
885 #define EC_MUST_BE_REDUNDANT(eclass) \
886  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
887 
888 /*
889  * EquivalenceMember - one member expression of an EquivalenceClass
890  *
891  * em_is_child signifies that this element was built by transposing a member
892  * for an appendrel parent relation to represent the corresponding expression
893  * for an appendrel child. These members are used for determining the
894  * pathkeys of scans on the child relation and for explicitly sorting the
895  * child when necessary to build a MergeAppend path for the whole appendrel
896  * tree. An em_is_child member has no impact on the properties of the EC as a
897  * whole; in particular the EC's ec_relids field does NOT include the child
898  * relation. An em_is_child member should never be marked em_is_const nor
899  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
900  * members are not really full-fledged members of the EC, but just reflections
901  * or doppelgangers of real members. Most operations on EquivalenceClasses
902  * should ignore em_is_child members, and those that don't should test
903  * em_relids to make sure they only consider relevant members.
904  *
905  * em_datatype is usually the same as exprType(em_expr), but can be
906  * different when dealing with a binary-compatible opfamily; in particular
907  * anyarray_ops would never work without this. Use em_datatype when
908  * looking up a specific btree operator to work with this expression.
909  */
910 typedef struct EquivalenceMember
911 {
913 
914  Expr *em_expr; /* the expression represented */
915  Relids em_relids; /* all relids appearing in em_expr */
916  Relids em_nullable_relids; /* nullable by lower outer joins */
917  bool em_is_const; /* expression is pseudoconstant? */
918  bool em_is_child; /* derived version for a child relation? */
919  Oid em_datatype; /* the "nominal type" used by the opfamily */
921 
922 /*
923  * PathKeys
924  *
925  * The sort ordering of a path is represented by a list of PathKey nodes.
926  * An empty list implies no known ordering. Otherwise the first item
927  * represents the primary sort key, the second the first secondary sort key,
928  * etc. The value being sorted is represented by linking to an
929  * EquivalenceClass containing that value and including pk_opfamily among its
930  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
931  * This is a convenient method because it makes it trivial to detect
932  * equivalent and closely-related orderings. (See optimizer/README for more
933  * information.)
934  *
935  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
936  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
937  * index types will use btree-compatible strategy numbers.
938  */
939 typedef struct PathKey
940 {
942 
943  EquivalenceClass *pk_eclass; /* the value that is ordered */
944  Oid pk_opfamily; /* btree opfamily defining the ordering */
945  int pk_strategy; /* sort direction (ASC or DESC) */
946  bool pk_nulls_first; /* do NULLs come before normal values? */
947 } PathKey;
948 
949 
950 /*
951  * PathTarget
952  *
953  * This struct contains what we need to know during planning about the
954  * targetlist (output columns) that a Path will compute. Each RelOptInfo
955  * includes a default PathTarget, which its individual Paths may simply
956  * reference. However, in some cases a Path may compute outputs different
957  * from other Paths, and in that case we make a custom PathTarget for it.
958  * For example, an indexscan might return index expressions that would
959  * otherwise need to be explicitly calculated. (Note also that "upper"
960  * relations generally don't have useful default PathTargets.)
961  *
962  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
963  * though those will appear in finished Plans.
964  *
965  * sortgrouprefs[] is an array of the same length as exprs, containing the
966  * corresponding sort/group refnos, or zeroes for expressions not referenced
967  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
968  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
969  * we have not identified sort/group columns in this tlist. This allows us to
970  * deal with sort/group refnos when needed with less expense than including
971  * TargetEntry nodes in the exprs list.
972  */
973 typedef struct PathTarget
974 {
976  List *exprs; /* list of expressions to be computed */
977  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
978  QualCost cost; /* cost of evaluating the expressions */
979  int width; /* estimated avg width of result tuples */
980 } PathTarget;
981 
982 /* Convenience macro to get a sort/group refno from a PathTarget */
983 #define get_pathtarget_sortgroupref(target, colno) \
984  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
985 
986 
987 /*
988  * ParamPathInfo
989  *
990  * All parameterized paths for a given relation with given required outer rels
991  * link to a single ParamPathInfo, which stores common information such as
992  * the estimated rowcount for this parameterization. We do this partly to
993  * avoid recalculations, but mostly to ensure that the estimated rowcount
994  * is in fact the same for every such path.
995  *
996  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
997  * in join cases it's NIL because the set of relevant clauses varies depending
998  * on how the join is formed. The relevant clauses will appear in each
999  * parameterized join path's joinrestrictinfo list, instead.
1000  */
1001 typedef struct ParamPathInfo
1002 {
1004 
1005  Relids ppi_req_outer; /* rels supplying parameters used by path */
1006  double ppi_rows; /* estimated number of result tuples */
1007  List *ppi_clauses; /* join clauses available from outer rels */
1008 } ParamPathInfo;
1009 
1010 
1011 /*
1012  * Type "Path" is used as-is for sequential-scan paths, as well as some other
1013  * simple plan types that we don't need any extra information in the path for.
1014  * For other path types it is the first component of a larger struct.
1015  *
1016  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
1017  * It is partially redundant with the Path's NodeTag, but allows us to use
1018  * the same Path type for multiple Plan types when there is no need to
1019  * distinguish the Plan type during path processing.
1020  *
1021  * "parent" identifies the relation this Path scans, and "pathtarget"
1022  * describes the precise set of output columns the Path would compute.
1023  * In simple cases all Paths for a given rel share the same targetlist,
1024  * which we represent by having path->pathtarget equal to parent->reltarget.
1025  *
1026  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
1027  * relation(s) that provide parameter values to each scan of this path.
1028  * That means this path can only be joined to those rels by means of nestloop
1029  * joins with this path on the inside. Also note that a parameterized path
1030  * is responsible for testing all "movable" joinclauses involving this rel
1031  * and the specified outer rel(s).
1032  *
1033  * "rows" is the same as parent->rows in simple paths, but in parameterized
1034  * paths and UniquePaths it can be less than parent->rows, reflecting the
1035  * fact that we've filtered by extra join conditions or removed duplicates.
1036  *
1037  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
1038  * ordering of the path's output rows.
1039  */
1040 typedef struct Path
1041 {
1043 
1044  NodeTag pathtype; /* tag identifying scan/join method */
1045 
1046  RelOptInfo *parent; /* the relation this path can build */
1047  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
1048 
1049  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
1050 
1051  bool parallel_aware; /* engage parallel-aware logic? */
1052  bool parallel_safe; /* OK to use as part of parallel plan? */
1053  int parallel_workers; /* desired # of workers; 0 = not parallel */
1054 
1055  /* estimated size/costs for path (see costsize.c for more info) */
1056  double rows; /* estimated number of result tuples */
1057  Cost startup_cost; /* cost expended before fetching any tuples */
1058  Cost total_cost; /* total cost (assuming all tuples fetched) */
1059 
1060  List *pathkeys; /* sort ordering of path's output */
1061  /* pathkeys is a List of PathKey nodes; see above */
1062 } Path;
1063 
1064 /* Macro for extracting a path's parameterization relids; beware double eval */
1065 #define PATH_REQ_OUTER(path) \
1066  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
1067 
1068 /*----------
1069  * IndexPath represents an index scan over a single index.
1070  *
1071  * This struct is used for both regular indexscans and index-only scans;
1072  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
1073  *
1074  * 'indexinfo' is the index to be scanned.
1075  *
1076  * 'indexclauses' is a list of index qualification clauses, with implicit
1077  * AND semantics across the list. Each clause is a RestrictInfo node from
1078  * the query's WHERE or JOIN conditions. An empty list implies a full
1079  * index scan.
1080  *
1081  * 'indexquals' has the same structure as 'indexclauses', but it contains
1082  * the actual index qual conditions that can be used with the index.
1083  * In simple cases this is identical to 'indexclauses', but when special
1084  * indexable operators appear in 'indexclauses', they are replaced by the
1085  * derived indexscannable conditions in 'indexquals'.
1086  *
1087  * 'indexqualcols' is an integer list of index column numbers (zero-based)
1088  * of the same length as 'indexquals', showing which index column each qual
1089  * is meant to be used with. 'indexquals' is required to be ordered by
1090  * index column, so 'indexqualcols' must form a nondecreasing sequence.
1091  * (The order of multiple quals for the same index column is unspecified.)
1092  *
1093  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
1094  * been found to be usable as ordering operators for an amcanorderbyop index.
1095  * The list must match the path's pathkeys, ie, one expression per pathkey
1096  * in the same order. These are not RestrictInfos, just bare expressions,
1097  * since they generally won't yield booleans. Also, unlike the case for
1098  * quals, it's guaranteed that each expression has the index key on the left
1099  * side of the operator.
1100  *
1101  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
1102  * of the same length as 'indexorderbys', showing which index column each
1103  * ORDER BY expression is meant to be used with. (There is no restriction
1104  * on which index column each ORDER BY can be used with.)
1105  *
1106  * 'indexscandir' is one of:
1107  * ForwardScanDirection: forward scan of an ordered index
1108  * BackwardScanDirection: backward scan of an ordered index
1109  * NoMovementScanDirection: scan of an unordered index, or don't care
1110  * (The executor doesn't care whether it gets ForwardScanDirection or
1111  * NoMovementScanDirection for an indexscan, but the planner wants to
1112  * distinguish ordered from unordered indexes for building pathkeys.)
1113  *
1114  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
1115  * we need not recompute them when considering using the same index in a
1116  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
1117  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
1118  *----------
1119  */
1120 typedef struct IndexPath
1121 {
1132 } IndexPath;
1133 
1134 /*
1135  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
1136  * instead of directly accessing the heap, followed by AND/OR combinations
1137  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
1138  * Note that the output is always considered unordered, since it will come
1139  * out in physical heap order no matter what the underlying indexes did.
1140  *
1141  * The individual indexscans are represented by IndexPath nodes, and any
1142  * logic on top of them is represented by a tree of BitmapAndPath and
1143  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
1144  * to represent a regular (or index-only) index scan plan, and as the child
1145  * of a BitmapHeapPath that represents scanning the same index using a
1146  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
1147  * always represent the costs to use it as a regular (or index-only)
1148  * IndexScan. The costs of a BitmapIndexScan can be computed using the
1149  * IndexPath's indextotalcost and indexselectivity.
1150  */
1151 typedef struct BitmapHeapPath
1152 {
1154  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1155 } BitmapHeapPath;
1156 
1157 /*
1158  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1159  * part of the substructure of a BitmapHeapPath. The Path structure is
1160  * a bit more heavyweight than we really need for this, but for simplicity
1161  * we make it a derivative of Path anyway.
1162  */
1163 typedef struct BitmapAndPath
1164 {
1166  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1168 } BitmapAndPath;
1169 
1170 /*
1171  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1172  * part of the substructure of a BitmapHeapPath. The Path structure is
1173  * a bit more heavyweight than we really need for this, but for simplicity
1174  * we make it a derivative of Path anyway.
1175  */
1176 typedef struct BitmapOrPath
1177 {
1179  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1181 } BitmapOrPath;
1182 
1183 /*
1184  * TidPath represents a scan by TID
1185  *
1186  * tidquals is an implicitly OR'ed list of qual expressions of the form
1187  * "CTID = pseudoconstant" or "CTID = ANY(pseudoconstant_array)".
1188  * Note they are bare expressions, not RestrictInfos.
1189  */
1190 typedef struct TidPath
1191 {
1193  List *tidquals; /* qual(s) involving CTID = something */
1194 } TidPath;
1195 
1196 /*
1197  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1198  *
1199  * Note that the subpath comes from a different planning domain; for example
1200  * RTE indexes within it mean something different from those known to the
1201  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1202  * interpret the subpath.
1203  */
1204 typedef struct SubqueryScanPath
1205 {
1207  Path *subpath; /* path representing subquery execution */
1209 
1210 /*
1211  * ForeignPath represents a potential scan of a foreign table, foreign join
1212  * or foreign upper-relation.
1213  *
1214  * fdw_private stores FDW private data about the scan. While fdw_private is
1215  * not actually touched by the core code during normal operations, it's
1216  * generally a good idea to use a representation that can be dumped by
1217  * nodeToString(), so that you can examine the structure during debugging
1218  * with tools like pprint().
1219  */
1220 typedef struct ForeignPath
1221 {
1225 } ForeignPath;
1226 
1227 /*
1228  * CustomPath represents a table scan done by some out-of-core extension.
1229  *
1230  * We provide a set of hooks here - which the provider must take care to set
1231  * up correctly - to allow extensions to supply their own methods of scanning
1232  * a relation. For example, a provider might provide GPU acceleration, a
1233  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1234  *
1235  * CustomPaths can be injected into the planning process for a relation by
1236  * set_rel_pathlist_hook functions.
1237  *
1238  * Core code must avoid assuming that the CustomPath is only as large as
1239  * the structure declared here; providers are allowed to make it the first
1240  * element in a larger structure. (Since the planner never copies Paths,
1241  * this doesn't add any complication.) However, for consistency with the
1242  * FDW case, we provide a "custom_private" field in CustomPath; providers
1243  * may prefer to use that rather than define another struct type.
1244  */
1245 
1246 struct CustomPathMethods;
1247 
1248 typedef struct CustomPath
1249 {
1251  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1252  * nodes/extensible.h */
1253  List *custom_paths; /* list of child Path nodes, if any */
1256 } CustomPath;
1257 
1258 /*
1259  * AppendPath represents an Append plan, ie, successive execution of
1260  * several member plans.
1261  *
1262  * For partial Append, 'subpaths' contains non-partial subpaths followed by
1263  * partial subpaths.
1264  *
1265  * Note: it is possible for "subpaths" to contain only one, or even no,
1266  * elements. These cases are optimized during create_append_plan.
1267  * In particular, an AppendPath with no subpaths is a "dummy" path that
1268  * is created to represent the case that a relation is provably empty.
1269  */
1270 typedef struct AppendPath
1271 {
1273  /* RT indexes of non-leaf tables in a partition tree */
1275  List *subpaths; /* list of component Paths */
1276 
1277  /* Index of first partial path in subpaths */
1279 } AppendPath;
1280 
1281 #define IS_DUMMY_PATH(p) \
1282  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1283 
1284 /* A relation that's been proven empty will have one path that is dummy */
1285 #define IS_DUMMY_REL(r) \
1286  ((r)->cheapest_total_path != NULL && \
1287  IS_DUMMY_PATH((r)->cheapest_total_path))
1288 
1289 /*
1290  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1291  * results from several member plans to produce similarly-sorted output.
1292  */
1293 typedef struct MergeAppendPath
1294 {
1296  /* RT indexes of non-leaf tables in a partition tree */
1298  List *subpaths; /* list of component Paths */
1299  double limit_tuples; /* hard limit on output tuples, or -1 */
1300 } MergeAppendPath;
1301 
1302 /*
1303  * ResultPath represents use of a Result plan node to compute a variable-free
1304  * targetlist with no underlying tables (a "SELECT expressions" query).
1305  * The query could have a WHERE clause, too, represented by "quals".
1306  *
1307  * Note that quals is a list of bare clauses, not RestrictInfos.
1308  */
1309 typedef struct ResultPath
1310 {
1313 } ResultPath;
1314 
1315 /*
1316  * MaterialPath represents use of a Material plan node, i.e., caching of
1317  * the output of its subpath. This is used when the subpath is expensive
1318  * and needs to be scanned repeatedly, or when we need mark/restore ability
1319  * and the subpath doesn't have it.
1320  */
1321 typedef struct MaterialPath
1322 {
1325 } MaterialPath;
1326 
1327 /*
1328  * UniquePath represents elimination of distinct rows from the output of
1329  * its subpath.
1330  *
1331  * This can represent significantly different plans: either hash-based or
1332  * sort-based implementation, or a no-op if the input path can be proven
1333  * distinct already. The decision is sufficiently localized that it's not
1334  * worth having separate Path node types. (Note: in the no-op case, we could
1335  * eliminate the UniquePath node entirely and just return the subpath; but
1336  * it's convenient to have a UniquePath in the path tree to signal upper-level
1337  * routines that the input is known distinct.)
1338  */
1339 typedef enum
1340 {
1341  UNIQUE_PATH_NOOP, /* input is known unique already */
1342  UNIQUE_PATH_HASH, /* use hashing */
1343  UNIQUE_PATH_SORT /* use sorting */
1345 
1346 typedef struct UniquePath
1347 {
1351  List *in_operators; /* equality operators of the IN clause */
1352  List *uniq_exprs; /* expressions to be made unique */
1353 } UniquePath;
1354 
1355 /*
1356  * GatherPath runs several copies of a plan in parallel and collects the
1357  * results. The parallel leader may also execute the plan, unless the
1358  * single_copy flag is set.
1359  */
1360 typedef struct GatherPath
1361 {
1363  Path *subpath; /* path for each worker */
1364  bool single_copy; /* don't execute path more than once */
1365  int num_workers; /* number of workers sought to help */
1366 } GatherPath;
1367 
1368 /*
1369  * GatherMergePath runs several copies of a plan in parallel and collects
1370  * the results, preserving their common sort order. For gather merge, the
1371  * parallel leader always executes the plan too, so we don't need single_copy.
1372  */
1373 typedef struct GatherMergePath
1374 {
1376  Path *subpath; /* path for each worker */
1377  int num_workers; /* number of workers sought to help */
1378 } GatherMergePath;
1379 
1380 
1381 /*
1382  * All join-type paths share these fields.
1383  */
1384 
1385 typedef struct JoinPath
1386 {
1388 
1390 
1391  bool inner_unique; /* each outer tuple provably matches no more
1392  * than one inner tuple */
1393 
1394  Path *outerjoinpath; /* path for the outer side of the join */
1395  Path *innerjoinpath; /* path for the inner side of the join */
1396 
1397  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1398 
1399  /*
1400  * See the notes for RelOptInfo and ParamPathInfo to understand why
1401  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1402  * parent RelOptInfo.
1403  */
1404 } JoinPath;
1405 
1406 /*
1407  * A nested-loop path needs no special fields.
1408  */
1409 
1411 
1412 /*
1413  * A mergejoin path has these fields.
1414  *
1415  * Unlike other path types, a MergePath node doesn't represent just a single
1416  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1417  * node itself, there can be a Sort node for the outer input, a Sort node
1418  * for the inner input, and/or a Material node for the inner input. We could
1419  * represent these nodes by separate path nodes, but considering how many
1420  * different merge paths are investigated during a complex join problem,
1421  * it seems better to avoid unnecessary palloc overhead.
1422  *
1423  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1424  * that will be used in the merge.
1425  *
1426  * Note that the mergeclauses are a subset of the parent relation's
1427  * restriction-clause list. Any join clauses that are not mergejoinable
1428  * appear only in the parent's restrict list, and must be checked by a
1429  * qpqual at execution time.
1430  *
1431  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1432  * (resp. inner path) is already ordered appropriately for the
1433  * mergejoin. If it is not NIL then it is a PathKeys list describing
1434  * the ordering that must be created by an explicit Sort node.
1435  *
1436  * skip_mark_restore is true if the executor need not do mark/restore calls.
1437  * Mark/restore overhead is usually required, but can be skipped if we know
1438  * that the executor need find only one match per outer tuple, and that the
1439  * mergeclauses are sufficient to identify a match. In such cases the
1440  * executor can immediately advance the outer relation after processing a
1441  * match, and therefoere it need never back up the inner relation.
1442  *
1443  * materialize_inner is true if a Material node should be placed atop the
1444  * inner input. This may appear with or without an inner Sort step.
1445  */
1446 
1447 typedef struct MergePath
1448 {
1450  List *path_mergeclauses; /* join clauses to be used for merge */
1451  List *outersortkeys; /* keys for explicit sort, if any */
1452  List *innersortkeys; /* keys for explicit sort, if any */
1453  bool skip_mark_restore; /* can executor skip mark/restore? */
1454  bool materialize_inner; /* add Materialize to inner? */
1455 } MergePath;
1456 
1457 /*
1458  * A hashjoin path has these fields.
1459  *
1460  * The remarks above for mergeclauses apply for hashclauses as well.
1461  *
1462  * Hashjoin does not care what order its inputs appear in, so we have
1463  * no need for sortkeys.
1464  */
1465 
1466 typedef struct HashPath
1467 {
1469  List *path_hashclauses; /* join clauses used for hashing */
1470  int num_batches; /* number of batches expected */
1471  double inner_rows_total; /* total inner rows expected */
1472 } HashPath;
1473 
1474 /*
1475  * ProjectionPath represents a projection (that is, targetlist computation)
1476  *
1477  * Nominally, this path node represents using a Result plan node to do a
1478  * projection step. However, if the input plan node supports projection,
1479  * we can just modify its output targetlist to do the required calculations
1480  * directly, and not need a Result. In some places in the planner we can just
1481  * jam the desired PathTarget into the input path node (and adjust its cost
1482  * accordingly), so we don't need a ProjectionPath. But in other places
1483  * it's necessary to not modify the input path node, so we need a separate
1484  * ProjectionPath node, which is marked dummy to indicate that we intend to
1485  * assign the work to the input plan node. The estimated cost for the
1486  * ProjectionPath node will account for whether a Result will be used or not.
1487  */
1488 typedef struct ProjectionPath
1489 {
1491  Path *subpath; /* path representing input source */
1492  bool dummypp; /* true if no separate Result is needed */
1493 } ProjectionPath;
1494 
1495 /*
1496  * ProjectSetPath represents evaluation of a targetlist that includes
1497  * set-returning function(s), which will need to be implemented by a
1498  * ProjectSet plan node.
1499  */
1500 typedef struct ProjectSetPath
1501 {
1503  Path *subpath; /* path representing input source */
1504 } ProjectSetPath;
1505 
1506 /*
1507  * SortPath represents an explicit sort step
1508  *
1509  * The sort keys are, by definition, the same as path.pathkeys.
1510  *
1511  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1512  * same as the input's pathtarget.
1513  */
1514 typedef struct SortPath
1515 {
1517  Path *subpath; /* path representing input source */
1518 } SortPath;
1519 
1520 /*
1521  * GroupPath represents grouping (of presorted input)
1522  *
1523  * groupClause represents the columns to be grouped on; the input path
1524  * must be at least that well sorted.
1525  *
1526  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1527  */
1528 typedef struct GroupPath
1529 {
1531  Path *subpath; /* path representing input source */
1532  List *groupClause; /* a list of SortGroupClause's */
1533  List *qual; /* quals (HAVING quals), if any */
1534 } GroupPath;
1535 
1536 /*
1537  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1538  *
1539  * The columns to be compared are the first numkeys columns of the path's
1540  * pathkeys. The input is presumed already sorted that way.
1541  */
1542 typedef struct UpperUniquePath
1543 {
1545  Path *subpath; /* path representing input source */
1546  int numkeys; /* number of pathkey columns to compare */
1547 } UpperUniquePath;
1548 
1549 /*
1550  * AggPath represents generic computation of aggregate functions
1551  *
1552  * This may involve plain grouping (but not grouping sets), using either
1553  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1554  * appropriately presorted.
1555  */
1556 typedef struct AggPath
1557 {
1559  Path *subpath; /* path representing input source */
1560  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1561  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1562  double numGroups; /* estimated number of groups in input */
1563  List *groupClause; /* a list of SortGroupClause's */
1564  List *qual; /* quals (HAVING quals), if any */
1565 } AggPath;
1566 
1567 /*
1568  * Various annotations used for grouping sets in the planner.
1569  */
1570 
1571 typedef struct GroupingSetData
1572 {
1574  List *set; /* grouping set as list of sortgrouprefs */
1575  double numGroups; /* est. number of result groups */
1576 } GroupingSetData;
1577 
1578 typedef struct RollupData
1579 {
1581  List *groupClause; /* applicable subset of parse->groupClause */
1582  List *gsets; /* lists of integer indexes into groupClause */
1583  List *gsets_data; /* list of GroupingSetData */
1584  double numGroups; /* est. number of result groups */
1585  bool hashable; /* can be hashed */
1586  bool is_hashed; /* to be implemented as a hashagg */
1587 } RollupData;
1588 
1589 /*
1590  * GroupingSetsPath represents a GROUPING SETS aggregation
1591  */
1592 
1593 typedef struct GroupingSetsPath
1594 {
1596  Path *subpath; /* path representing input source */
1597  AggStrategy aggstrategy; /* basic strategy */
1598  List *rollups; /* list of RollupData */
1599  List *qual; /* quals (HAVING quals), if any */
1601 
1602 /*
1603  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1604  */
1605 typedef struct MinMaxAggPath
1606 {
1608  List *mmaggregates; /* list of MinMaxAggInfo */
1609  List *quals; /* HAVING quals, if any */
1610 } MinMaxAggPath;
1611 
1612 /*
1613  * WindowAggPath represents generic computation of window functions
1614  *
1615  * Note: winpathkeys is separate from path.pathkeys because the actual sort
1616  * order might be an extension of winpathkeys; but createplan.c needs to
1617  * know exactly how many pathkeys match the window clause.
1618  */
1619 typedef struct WindowAggPath
1620 {
1622  Path *subpath; /* path representing input source */
1623  WindowClause *winclause; /* WindowClause we'll be using */
1624  List *winpathkeys; /* PathKeys for PARTITION keys + ORDER keys */
1625 } WindowAggPath;
1626 
1627 /*
1628  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1629  */
1630 typedef struct SetOpPath
1631 {
1633  Path *subpath; /* path representing input source */
1634  SetOpCmd cmd; /* what to do, see nodes.h */
1635  SetOpStrategy strategy; /* how to do it, see nodes.h */
1636  List *distinctList; /* SortGroupClauses identifying target cols */
1637  AttrNumber flagColIdx; /* where is the flag column, if any */
1638  int firstFlag; /* flag value for first input relation */
1639  double numGroups; /* estimated number of groups in input */
1640 } SetOpPath;
1641 
1642 /*
1643  * RecursiveUnionPath represents a recursive UNION node
1644  */
1645 typedef struct RecursiveUnionPath
1646 {
1648  Path *leftpath; /* paths representing input sources */
1650  List *distinctList; /* SortGroupClauses identifying target cols */
1651  int wtParam; /* ID of Param representing work table */
1652  double numGroups; /* estimated number of groups in input */
1654 
1655 /*
1656  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1657  */
1658 typedef struct LockRowsPath
1659 {
1661  Path *subpath; /* path representing input source */
1662  List *rowMarks; /* a list of PlanRowMark's */
1663  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1664 } LockRowsPath;
1665 
1666 /*
1667  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1668  *
1669  * We represent most things that will be in the ModifyTable plan node
1670  * literally, except we have child Path(s) not Plan(s). But analysis of the
1671  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1672  */
1673 typedef struct ModifyTablePath
1674 {
1676  CmdType operation; /* INSERT, UPDATE, or DELETE */
1677  bool canSetTag; /* do we set the command tag/es_processed? */
1678  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1679  /* RT indexes of non-leaf tables in a partition tree */
1681  bool partColsUpdated; /* some part key in hierarchy updated */
1682  List *resultRelations; /* integer list of RT indexes */
1683  List *subpaths; /* Path(s) producing source data */
1684  List *subroots; /* per-target-table PlannerInfos */
1685  List *withCheckOptionLists; /* per-target-table WCO lists */
1686  List *returningLists; /* per-target-table RETURNING tlists */
1687  List *rowMarks; /* PlanRowMarks (non-locking only) */
1688  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1689  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1690 } ModifyTablePath;
1691 
1692 /*
1693  * LimitPath represents applying LIMIT/OFFSET restrictions
1694  */
1695 typedef struct LimitPath
1696 {
1698  Path *subpath; /* path representing input source */
1699  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1700  Node *limitCount; /* COUNT parameter, or NULL if none */
1701 } LimitPath;
1702 
1703 
1704 /*
1705  * Restriction clause info.
1706  *
1707  * We create one of these for each AND sub-clause of a restriction condition
1708  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1709  * ANDed, we can use any one of them or any subset of them to filter out
1710  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1711  * stores data used by the optimizer while choosing the best query plan.
1712  *
1713  * If a restriction clause references a single base relation, it will appear
1714  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1715  *
1716  * If a restriction clause references more than one base rel, it will
1717  * appear in the joininfo list of every RelOptInfo that describes a strict
1718  * subset of the base rels mentioned in the clause. The joininfo lists are
1719  * used to drive join tree building by selecting plausible join candidates.
1720  * The clause cannot actually be applied until we have built a join rel
1721  * containing all the base rels it references, however.
1722  *
1723  * When we construct a join rel that includes all the base rels referenced
1724  * in a multi-relation restriction clause, we place that clause into the
1725  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1726  * right sub-path includes all base rels referenced in the clause. The clause
1727  * will be applied at that join level, and will not propagate any further up
1728  * the join tree. (Note: the "predicate migration" code was once intended to
1729  * push restriction clauses up and down the plan tree based on evaluation
1730  * costs, but it's dead code and is unlikely to be resurrected in the
1731  * foreseeable future.)
1732  *
1733  * Note that in the presence of more than two rels, a multi-rel restriction
1734  * might reach different heights in the join tree depending on the join
1735  * sequence we use. So, these clauses cannot be associated directly with
1736  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1737  *
1738  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1739  * equalities that are not outerjoin-delayed) are handled a bit differently.
1740  * Initially we attach them to the EquivalenceClasses that are derived from
1741  * them. When we construct a scan or join path, we look through all the
1742  * EquivalenceClasses and generate derived RestrictInfos representing the
1743  * minimal set of conditions that need to be checked for this particular scan
1744  * or join to enforce that all members of each EquivalenceClass are in fact
1745  * equal in all rows emitted by the scan or join.
1746  *
1747  * When dealing with outer joins we have to be very careful about pushing qual
1748  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1749  * be evaluated exactly at that join node, unless they are "degenerate"
1750  * conditions that reference only Vars from the nullable side of the join.
1751  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1752  * down below the outer join, if they reference any nullable Vars.
1753  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1754  * pushed down to a lower level than its original syntactic placement in the
1755  * join tree would suggest. If an outer join prevents us from pushing a qual
1756  * down to its "natural" semantic level (the level associated with just the
1757  * base rels used in the qual) then we mark the qual with a "required_relids"
1758  * value including more than just the base rels it actually uses. By
1759  * pretending that the qual references all the rels required to form the outer
1760  * join, we prevent it from being evaluated below the outer join's joinrel.
1761  * When we do form the outer join's joinrel, we still need to distinguish
1762  * those quals that are actually in that join's JOIN/ON condition from those
1763  * that appeared elsewhere in the tree and were pushed down to the join rel
1764  * because they used no other rels. That's what the is_pushed_down flag is
1765  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1766  * rels listed in required_relids. A clause that originally came from WHERE
1767  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1768  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1769  * if we decide that it can be pushed down into the nullable side of the join.
1770  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1771  * (In short, is_pushed_down is only false for non-degenerate outer join
1772  * conditions. Possibly we should rename it to reflect that meaning?)
1773  *
1774  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1775  * if the clause's applicability must be delayed due to any outer joins
1776  * appearing below it (ie, it has to be postponed to some join level higher
1777  * than the set of relations it actually references).
1778  *
1779  * There is also an outer_relids field, which is NULL except for outer join
1780  * clauses; for those, it is the set of relids on the outer side of the
1781  * clause's outer join. (These are rels that the clause cannot be applied to
1782  * in parameterized scans, since pushing it into the join's outer side would
1783  * lead to wrong answers.)
1784  *
1785  * There is also a nullable_relids field, which is the set of rels the clause
1786  * references that can be forced null by some outer join below the clause.
1787  *
1788  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1789  * a clause might reference some nullable rels and yet not be
1790  * outerjoin_delayed because it also references all the other rels of the
1791  * outer join(s). A clause that is not outerjoin_delayed can be enforced
1792  * anywhere it is computable.
1793  *
1794  * To handle security-barrier conditions efficiently, we mark RestrictInfo
1795  * nodes with a security_level field, in which higher values identify clauses
1796  * coming from less-trusted sources. The exact semantics are that a clause
1797  * cannot be evaluated before another clause with a lower security_level value
1798  * unless the first clause is leakproof. As with outer-join clauses, this
1799  * creates a reason for clauses to sometimes need to be evaluated higher in
1800  * the join tree than their contents would suggest; and even at a single plan
1801  * node, this rule constrains the order of application of clauses.
1802  *
1803  * In general, the referenced clause might be arbitrarily complex. The
1804  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
1805  * or hashjoin clauses are limited (e.g., no volatile functions). The code
1806  * for each kind of path is responsible for identifying the restrict clauses
1807  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
1808  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
1809  * of the finished Plan node, where they will be enforced by general-purpose
1810  * qual-expression-evaluation code. (But we are still entitled to count
1811  * their selectivity when estimating the result tuple count, if we
1812  * can guess what it is...)
1813  *
1814  * When the referenced clause is an OR clause, we generate a modified copy
1815  * in which additional RestrictInfo nodes are inserted below the top-level
1816  * OR/AND structure. This is a convenience for OR indexscan processing:
1817  * indexquals taken from either the top level or an OR subclause will have
1818  * associated RestrictInfo nodes.
1819  *
1820  * The can_join flag is set true if the clause looks potentially useful as
1821  * a merge or hash join clause, that is if it is a binary opclause with
1822  * nonoverlapping sets of relids referenced in the left and right sides.
1823  * (Whether the operator is actually merge or hash joinable isn't checked,
1824  * however.)
1825  *
1826  * The pseudoconstant flag is set true if the clause contains no Vars of
1827  * the current query level and no volatile functions. Such a clause can be
1828  * pulled out and used as a one-time qual in a gating Result node. We keep
1829  * pseudoconstant clauses in the same lists as other RestrictInfos so that
1830  * the regular clause-pushing machinery can assign them to the correct join
1831  * level, but they need to be treated specially for cost and selectivity
1832  * estimates. Note that a pseudoconstant clause can never be an indexqual
1833  * or merge or hash join clause, so it's of no interest to large parts of
1834  * the planner.
1835  *
1836  * When join clauses are generated from EquivalenceClasses, there may be
1837  * several equally valid ways to enforce join equivalence, of which we need
1838  * apply only one. We mark clauses of this kind by setting parent_ec to
1839  * point to the generating EquivalenceClass. Multiple clauses with the same
1840  * parent_ec in the same join are redundant.
1841  */
1842 
1843 typedef struct RestrictInfo
1844 {
1846 
1847  Expr *clause; /* the represented clause of WHERE or JOIN */
1848 
1849  bool is_pushed_down; /* true if clause was pushed down in level */
1850 
1851  bool outerjoin_delayed; /* true if delayed by lower outer join */
1852 
1853  bool can_join; /* see comment above */
1854 
1855  bool pseudoconstant; /* see comment above */
1856 
1857  bool leakproof; /* true if known to contain no leaked Vars */
1858 
1859  Index security_level; /* see comment above */
1860 
1861  /* The set of relids (varnos) actually referenced in the clause: */
1863 
1864  /* The set of relids required to evaluate the clause: */
1866 
1867  /* If an outer-join clause, the outer-side relations, else NULL: */
1869 
1870  /* The relids used in the clause that are nullable by lower outer joins: */
1872 
1873  /* These fields are set for any binary opclause: */
1874  Relids left_relids; /* relids in left side of clause */
1875  Relids right_relids; /* relids in right side of clause */
1876 
1877  /* This field is NULL unless clause is an OR clause: */
1878  Expr *orclause; /* modified clause with RestrictInfos */
1879 
1880  /* This field is NULL unless clause is potentially redundant: */
1881  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
1882 
1883  /* cache space for cost and selectivity */
1884  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
1885  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
1886  * semantics; -1 if not yet set; >1 means a
1887  * redundant clause */
1888  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
1889  * not yet set */
1890 
1891  /* valid if clause is mergejoinable, else NIL */
1892  List *mergeopfamilies; /* opfamilies containing clause operator */
1893 
1894  /* cache space for mergeclause processing; NULL if not yet set */
1895  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
1896  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
1897  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
1898  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
1899  List *scansel_cache; /* list of MergeScanSelCache structs */
1900 
1901  /* transient workspace for use while considering a specific join path */
1902  bool outer_is_left; /* T = outer var on left, F = on right */
1903 
1904  /* valid if clause is hashjoinable, else InvalidOid: */
1905  Oid hashjoinoperator; /* copy of clause operator */
1906 
1907  /* cache space for hashclause processing; -1 if not yet set */
1908  Selectivity left_bucketsize; /* avg bucketsize of left side */
1909  Selectivity right_bucketsize; /* avg bucketsize of right side */
1910  Selectivity left_mcvfreq; /* left side's most common val's freq */
1911  Selectivity right_mcvfreq; /* right side's most common val's freq */
1912 } RestrictInfo;
1913 
1914 /*
1915  * Since mergejoinscansel() is a relatively expensive function, and would
1916  * otherwise be invoked many times while planning a large join tree,
1917  * we go out of our way to cache its results. Each mergejoinable
1918  * RestrictInfo carries a list of the specific sort orderings that have
1919  * been considered for use with it, and the resulting selectivities.
1920  */
1921 typedef struct MergeScanSelCache
1922 {
1923  /* Ordering details (cache lookup key) */
1924  Oid opfamily; /* btree opfamily defining the ordering */
1925  Oid collation; /* collation for the ordering */
1926  int strategy; /* sort direction (ASC or DESC) */
1927  bool nulls_first; /* do NULLs come before normal values? */
1928  /* Results */
1929  Selectivity leftstartsel; /* first-join fraction for clause left side */
1930  Selectivity leftendsel; /* last-join fraction for clause left side */
1931  Selectivity rightstartsel; /* first-join fraction for clause right side */
1932  Selectivity rightendsel; /* last-join fraction for clause right side */
1934 
1935 /*
1936  * Placeholder node for an expression to be evaluated below the top level
1937  * of a plan tree. This is used during planning to represent the contained
1938  * expression. At the end of the planning process it is replaced by either
1939  * the contained expression or a Var referring to a lower-level evaluation of
1940  * the contained expression. Typically the evaluation occurs below an outer
1941  * join, and Var references above the outer join might thereby yield NULL
1942  * instead of the expression value.
1943  *
1944  * Although the planner treats this as an expression node type, it is not
1945  * recognized by the parser or executor, so we declare it here rather than
1946  * in primnodes.h.
1947  */
1948 
1949 typedef struct PlaceHolderVar
1950 {
1952  Expr *phexpr; /* the represented expression */
1953  Relids phrels; /* base relids syntactically within expr src */
1954  Index phid; /* ID for PHV (unique within planner run) */
1955  Index phlevelsup; /* > 0 if PHV belongs to outer query */
1956 } PlaceHolderVar;
1957 
1958 /*
1959  * "Special join" info.
1960  *
1961  * One-sided outer joins constrain the order of joining partially but not
1962  * completely. We flatten such joins into the planner's top-level list of
1963  * relations to join, but record information about each outer join in a
1964  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
1965  * join_info_list.
1966  *
1967  * Similarly, semijoins and antijoins created by flattening IN (subselect)
1968  * and EXISTS(subselect) clauses create partial constraints on join order.
1969  * These are likewise recorded in SpecialJoinInfo structs.
1970  *
1971  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
1972  * of planning for them, because this simplifies make_join_rel()'s API.
1973  *
1974  * min_lefthand and min_righthand are the sets of base relids that must be
1975  * available on each side when performing the special join. lhs_strict is
1976  * true if the special join's condition cannot succeed when the LHS variables
1977  * are all NULL (this means that an outer join can commute with upper-level
1978  * outer joins even if it appears in their RHS). We don't bother to set
1979  * lhs_strict for FULL JOINs, however.
1980  *
1981  * It is not valid for either min_lefthand or min_righthand to be empty sets;
1982  * if they were, this would break the logic that enforces join order.
1983  *
1984  * syn_lefthand and syn_righthand are the sets of base relids that are
1985  * syntactically below this special join. (These are needed to help compute
1986  * min_lefthand and min_righthand for higher joins.)
1987  *
1988  * delay_upper_joins is set true if we detect a pushed-down clause that has
1989  * to be evaluated after this join is formed (because it references the RHS).
1990  * Any outer joins that have such a clause and this join in their RHS cannot
1991  * commute with this join, because that would leave noplace to check the
1992  * pushed-down clause. (We don't track this for FULL JOINs, either.)
1993  *
1994  * For a semijoin, we also extract the join operators and their RHS arguments
1995  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
1996  * This is done in support of possibly unique-ifying the RHS, so we don't
1997  * bother unless at least one of semi_can_btree and semi_can_hash can be set
1998  * true. (You might expect that this information would be computed during
1999  * join planning; but it's helpful to have it available during planning of
2000  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
2001  *
2002  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
2003  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
2004  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
2005  *
2006  * For purposes of join selectivity estimation, we create transient
2007  * SpecialJoinInfo structures for regular inner joins; so it is possible
2008  * to have jointype == JOIN_INNER in such a structure, even though this is
2009  * not allowed within join_info_list. We also create transient
2010  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
2011  * cost estimation purposes it is sometimes useful to know the join size under
2012  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
2013  * of course the semi_xxx fields are not set meaningfully within such structs.
2014  */
2015 
2016 typedef struct SpecialJoinInfo
2017 {
2019  Relids min_lefthand; /* base relids in minimum LHS for join */
2020  Relids min_righthand; /* base relids in minimum RHS for join */
2021  Relids syn_lefthand; /* base relids syntactically within LHS */
2022  Relids syn_righthand; /* base relids syntactically within RHS */
2023  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
2024  bool lhs_strict; /* joinclause is strict for some LHS rel */
2025  bool delay_upper_joins; /* can't commute with upper RHS */
2026  /* Remaining fields are set only for JOIN_SEMI jointype: */
2027  bool semi_can_btree; /* true if semi_operators are all btree */
2028  bool semi_can_hash; /* true if semi_operators are all hash */
2029  List *semi_operators; /* OIDs of equality join operators */
2030  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
2031 } SpecialJoinInfo;
2032 
2033 /*
2034  * Append-relation info.
2035  *
2036  * When we expand an inheritable table or a UNION-ALL subselect into an
2037  * "append relation" (essentially, a list of child RTEs), we build an
2038  * AppendRelInfo for each child RTE. The list of AppendRelInfos indicates
2039  * which child RTEs must be included when expanding the parent, and each node
2040  * carries information needed to translate Vars referencing the parent into
2041  * Vars referencing that child.
2042  *
2043  * These structs are kept in the PlannerInfo node's append_rel_list.
2044  * Note that we just throw all the structs into one list, and scan the
2045  * whole list when desiring to expand any one parent. We could have used
2046  * a more complex data structure (eg, one list per parent), but this would
2047  * be harder to update during operations such as pulling up subqueries,
2048  * and not really any easier to scan. Considering that typical queries
2049  * will not have many different append parents, it doesn't seem worthwhile
2050  * to complicate things.
2051  *
2052  * Note: after completion of the planner prep phase, any given RTE is an
2053  * append parent having entries in append_rel_list if and only if its
2054  * "inh" flag is set. We clear "inh" for plain tables that turn out not
2055  * to have inheritance children, and (in an abuse of the original meaning
2056  * of the flag) we set "inh" for subquery RTEs that turn out to be
2057  * flattenable UNION ALL queries. This lets us avoid useless searches
2058  * of append_rel_list.
2059  *
2060  * Note: the data structure assumes that append-rel members are single
2061  * baserels. This is OK for inheritance, but it prevents us from pulling
2062  * up a UNION ALL member subquery if it contains a join. While that could
2063  * be fixed with a more complex data structure, at present there's not much
2064  * point because no improvement in the plan could result.
2065  */
2066 
2067 typedef struct AppendRelInfo
2068 {
2070 
2071  /*
2072  * These fields uniquely identify this append relationship. There can be
2073  * (in fact, always should be) multiple AppendRelInfos for the same
2074  * parent_relid, but never more than one per child_relid, since a given
2075  * RTE cannot be a child of more than one append parent.
2076  */
2077  Index parent_relid; /* RT index of append parent rel */
2078  Index child_relid; /* RT index of append child rel */
2079 
2080  /*
2081  * For an inheritance appendrel, the parent and child are both regular
2082  * relations, and we store their rowtype OIDs here for use in translating
2083  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
2084  * both subqueries with no named rowtype, and we store InvalidOid here.
2085  */
2086  Oid parent_reltype; /* OID of parent's composite type */
2087  Oid child_reltype; /* OID of child's composite type */
2088 
2089  /*
2090  * The N'th element of this list is a Var or expression representing the
2091  * child column corresponding to the N'th column of the parent. This is
2092  * used to translate Vars referencing the parent rel into references to
2093  * the child. A list element is NULL if it corresponds to a dropped
2094  * column of the parent (this is only possible for inheritance cases, not
2095  * UNION ALL). The list elements are always simple Vars for inheritance
2096  * cases, but can be arbitrary expressions in UNION ALL cases.
2097  *
2098  * Notice we only store entries for user columns (attno > 0). Whole-row
2099  * Vars are special-cased, and system columns (attno < 0) need no special
2100  * translation since their attnos are the same for all tables.
2101  *
2102  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
2103  * when copying into a subquery.
2104  */
2105  List *translated_vars; /* Expressions in the child's Vars */
2106 
2107  /*
2108  * We store the parent table's OID here for inheritance, or InvalidOid for
2109  * UNION ALL. This is only needed to help in generating error messages if
2110  * an attempt is made to reference a dropped parent column.
2111  */
2112  Oid parent_reloid; /* OID of parent relation */
2113 } AppendRelInfo;
2114 
2115 /*
2116  * For a partitioned table, this maps its RT index to the list of RT indexes
2117  * of the partitioned child tables in the partition tree. We need to
2118  * separately store this information, because we do not create AppendRelInfos
2119  * for the partitioned child tables of a parent table, since AppendRelInfos
2120  * contain information that is unnecessary for the partitioned child tables.
2121  * The child_rels list must contain at least one element, because the parent
2122  * partitioned table is itself counted as a child.
2123  *
2124  * These structs are kept in the PlannerInfo node's pcinfo_list.
2125  */
2127 {
2129 
2132  bool part_cols_updated; /* is the partition key of any of
2133  * the partitioned tables updated? */
2135 
2136 /*
2137  * For each distinct placeholder expression generated during planning, we
2138  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
2139  * This stores info that is needed centrally rather than in each copy of the
2140  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
2141  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
2142  * not just within a query level --- this is so that we need not reassign ID's
2143  * when pulling a subquery into its parent.
2144  *
2145  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
2146  * then allow it to bubble up like a Var until the ph_needed join level.
2147  * ph_needed has the same definition as attr_needed for a regular Var.
2148  *
2149  * The PlaceHolderVar's expression might contain LATERAL references to vars
2150  * coming from outside its syntactic scope. If so, those rels are *not*
2151  * included in ph_eval_at, but they are recorded in ph_lateral.
2152  *
2153  * Notice that when ph_eval_at is a join rather than a single baserel, the
2154  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
2155  * has to be formed below any outer joins that should null the PlaceHolderVar.
2156  *
2157  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
2158  * is actually referenced in the plan tree, so that unreferenced placeholders
2159  * don't result in unnecessary constraints on join order.
2160  */
2161 
2162 typedef struct PlaceHolderInfo
2163 {
2165 
2166  Index phid; /* ID for PH (unique within planner run) */
2167  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
2168  Relids ph_eval_at; /* lowest level we can evaluate value at */
2169  Relids ph_lateral; /* relids of contained lateral refs, if any */
2170  Relids ph_needed; /* highest level the value is needed at */
2171  int32 ph_width; /* estimated attribute width */
2172 } PlaceHolderInfo;
2173 
2174 /*
2175  * This struct describes one potentially index-optimizable MIN/MAX aggregate
2176  * function. MinMaxAggPath contains a list of these, and if we accept that
2177  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
2178  */
2179 typedef struct MinMaxAggInfo
2180 {
2182 
2183  Oid aggfnoid; /* pg_proc Oid of the aggregate */
2184  Oid aggsortop; /* Oid of its sort operator */
2185  Expr *target; /* expression we are aggregating on */
2186  PlannerInfo *subroot; /* modified "root" for planning the subquery */
2187  Path *path; /* access path for subquery */
2188  Cost pathcost; /* estimated cost to fetch first row */
2189  Param *param; /* param for subplan's output */
2190 } MinMaxAggInfo;
2191 
2192 /*
2193  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
2194  * node to another. They can be used to pass values down into subqueries (for
2195  * outer references in subqueries), or up out of subqueries (for the results
2196  * of a subplan), or from a NestLoop plan node into its inner relation (when
2197  * the inner scan is parameterized with values from the outer relation).
2198  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
2199  * the PARAM_EXEC Params it generates.
2200  *
2201  * Outer references are managed via root->plan_params, which is a list of
2202  * PlannerParamItems. While planning a subquery, each parent query level's
2203  * plan_params contains the values required from it by the current subquery.
2204  * During create_plan(), we use plan_params to track values that must be
2205  * passed from outer to inner sides of NestLoop plan nodes.
2206  *
2207  * The item a PlannerParamItem represents can be one of three kinds:
2208  *
2209  * A Var: the slot represents a variable of this level that must be passed
2210  * down because subqueries have outer references to it, or must be passed
2211  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
2212  * will always be zero.
2213  *
2214  * A PlaceHolderVar: this works much like the Var case, except that the
2215  * entry is a PlaceHolderVar node with a contained expression. The PHV
2216  * will have phlevelsup = 0, and the contained expression is adjusted
2217  * to match in level.
2218  *
2219  * An Aggref (with an expression tree representing its argument): the slot
2220  * represents an aggregate expression that is an outer reference for some
2221  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
2222  * is adjusted to match in level.
2223  *
2224  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
2225  * them into one slot, but we do not bother to do that for Aggrefs.
2226  * The scope of duplicate-elimination only extends across the set of
2227  * parameters passed from one query level into a single subquery, or for
2228  * nestloop parameters across the set of nestloop parameters used in a single
2229  * query level. So there is no possibility of a PARAM_EXEC slot being used
2230  * for conflicting purposes.
2231  *
2232  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2233  * from subplans (values that are setParam items for those subplans). These
2234  * IDs need not be tracked via PlannerParamItems, since we do not need any
2235  * duplicate-elimination nor later processing of the represented expressions.
2236  * Instead, we just record the assignment of the slot number by appending to
2237  * root->glob->paramExecTypes.
2238  */
2239 typedef struct PlannerParamItem
2240 {
2242 
2243  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2244  int paramId; /* its assigned PARAM_EXEC slot number */
2246 
2247 /*
2248  * When making cost estimates for a SEMI/ANTI/inner_unique join, there are
2249  * some correction factors that are needed in both nestloop and hash joins
2250  * to account for the fact that the executor can stop scanning inner rows
2251  * as soon as it finds a match to the current outer row. These numbers
2252  * depend only on the selected outer and inner join relations, not on the
2253  * particular paths used for them, so it's worthwhile to calculate them
2254  * just once per relation pair not once per considered path. This struct
2255  * is filled by compute_semi_anti_join_factors and must be passed along
2256  * to the join cost estimation functions.
2257  *
2258  * outer_match_frac is the fraction of the outer tuples that are
2259  * expected to have at least one match.
2260  * match_count is the average number of matches expected for
2261  * outer tuples that have at least one match.
2262  */
2263 typedef struct SemiAntiJoinFactors
2264 {
2268 
2269 /*
2270  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2271  *
2272  * restrictlist contains all of the RestrictInfo nodes for restriction
2273  * clauses that apply to this join
2274  * mergeclause_list is a list of RestrictInfo nodes for available
2275  * mergejoin clauses in this join
2276  * inner_unique is true if each outer tuple provably matches no more
2277  * than one inner tuple
2278  * sjinfo is extra info about special joins for selectivity estimation
2279  * semifactors is as shown above (only valid for SEMI/ANTI/inner_unique joins)
2280  * param_source_rels are OK targets for parameterization of result paths
2281  */
2282 typedef struct JoinPathExtraData
2283 {
2291 
2292 /*
2293  * For speed reasons, cost estimation for join paths is performed in two
2294  * phases: the first phase tries to quickly derive a lower bound for the
2295  * join cost, and then we check if that's sufficient to reject the path.
2296  * If not, we come back for a more refined cost estimate. The first phase
2297  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2298  * and possibly additional intermediate values. The second phase takes
2299  * these values as inputs to avoid repeating work.
2300  *
2301  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2302  * so seems best to put it here.)
2303  */
2304 typedef struct JoinCostWorkspace
2305 {
2306  /* Preliminary cost estimates --- must not be larger than final ones! */
2307  Cost startup_cost; /* cost expended before fetching any tuples */
2308  Cost total_cost; /* total cost (assuming all tuples fetched) */
2309 
2310  /* Fields below here should be treated as private to costsize.c */
2311  Cost run_cost; /* non-startup cost components */
2312 
2313  /* private for cost_nestloop code */
2314  Cost inner_run_cost; /* also used by cost_mergejoin code */
2316 
2317  /* private for cost_mergejoin code */
2318  double outer_rows;
2319  double inner_rows;
2322 
2323  /* private for cost_hashjoin code */
2328 
2329 #endif /* RELATION_H */
QualCost eval_cost
Definition: relation.h:1884
bool has_eclass_joins
Definition: relation.h:651
struct ModifyTablePath ModifyTablePath
struct Path * cheapest_unique_path
Definition: relation.h:604
NodeTag type
Definition: relation.h:1580
List * indexorderbycols
Definition: relation.h:1128
signed short int16
Definition: c.h:301
char maxParallelHazard
Definition: relation.h:133
List * group_pathkeys
Definition: relation.h:264
struct MinMaxAggPath MinMaxAggPath
List * rowMarks
Definition: relation.h:256
struct ForeignKeyOptInfo ForeignKeyOptInfo
Relids ph_needed
Definition: relation.h:2170
List * qual
Definition: relation.h:1533
bool semi_can_btree
Definition: relation.h:2027
Selectivity leftendsel
Definition: relation.h:1930
List * path_mergeclauses
Definition: relation.h:1450
int join_cur_level
Definition: relation.h:226
List * outersortkeys
Definition: relation.h:1451
List * distinctList
Definition: relation.h:1636
List * unique_for_rels
Definition: relation.h:640
JoinPath jpath
Definition: relation.h:1468
struct GroupingSetData GroupingSetData
PathTarget * pathtarget
Definition: relation.h:1047
Query * parse
Definition: relation.h:155
List * statlist
Definition: relation.h:623
List * returningLists
Definition: relation.h:1686
struct PathTarget PathTarget
Index security_level
Definition: relation.h:1859
OnConflictExpr * onconflict
Definition: relation.h:1688
List * groupClause
Definition: relation.h:1581
bool predOK
Definition: relation.h:756
Node * limitOffset
Definition: relation.h:1699
Path * subpath
Definition: relation.h:1545
struct PlaceHolderInfo PlaceHolderInfo
Path path
Definition: relation.h:1122
NodeTag type
Definition: relation.h:2069
Path * subpath
Definition: relation.h:1517
Relids ph_eval_at
Definition: relation.h:2168
List * plan_params
Definition: relation.h:169
PlaceHolderVar * ph_var
Definition: relation.h:2167
IndexOptInfo * indexinfo
Definition: relation.h:1123
SemiAntiJoinFactors semifactors
Definition: relation.h:2288
Index nominalRelation
Definition: relation.h:1678
Oid * indexcollations
Definition: relation.h:735
bool hasJoinRTEs
Definition: relation.h:302
Path * fdw_outerpath
Definition: relation.h:1223
RelOptKind reloptkind
Definition: relation.h:582
Relids * attr_needed
Definition: relation.h:618
List * custom_paths
Definition: relation.h:1253
List * query_pathkeys
Definition: relation.h:262
int num_batches
Definition: relation.h:1470
List * join_info_list
Definition: relation.h:250
Relids required_relids
Definition: relation.h:1865
SetOpStrategy strategy
Definition: relation.h:1635
Relids min_righthand
Definition: relation.h:2020
AggStrategy aggstrategy
Definition: relation.h:1560
bool materialize_inner
Definition: relation.h:1454
void * join_search_private
Definition: relation.h:319
Selectivity right_mcvfreq
Definition: relation.h:1911
Relids curOuterRels
Definition: relation.h:315
NodeTag type
Definition: relation.h:812
List * qual
Definition: relation.h:1564
bool leakproof
Definition: relation.h:1857
Index ec_min_security
Definition: relation.h:876
Expr * orclause
Definition: relation.h:1878
Selectivity outer_match_frac
Definition: relation.h:2265
Path * innerjoinpath
Definition: relation.h:1395
struct BitmapOrPath BitmapOrPath
List * indextlist
Definition: relation.h:748
struct AppendPath AppendPath
struct Path * cheapest_startup_path
Definition: relation.h:602
struct LockRowsPath LockRowsPath
Oid userid
Definition: relation.h:633
struct IndexPath IndexPath
struct CustomPath CustomPath
Relids em_nullable_relids
Definition: relation.h:916
int lastPlanNodeId
Definition: relation.h:123
double tuples
Definition: relation.h:625
Oid reltablespace
Definition: relation.h:614
Path * subpath
Definition: relation.h:1633
List * baserestrictinfo
Definition: relation.h:645
NodeTag type
Definition: relation.h:1042
List * ec_derives
Definition: relation.h:868
struct UniquePath UniquePath
List * rowMarks
Definition: relation.h:1687
NodeTag type
Definition: relation.h:2018
struct SpecialJoinInfo SpecialJoinInfo
Relids clause_relids
Definition: relation.h:1862
Param * param
Definition: relation.h:2189
struct JoinPathExtraData JoinPathExtraData
int parallel_workers
Definition: relation.h:1053
bool pseudoconstant
Definition: relation.h:1855
RelOptKind
Definition: relation.h:547
bool consider_param_startup
Definition: relation.h:592
struct PlannerInfo PlannerInfo
List * resultRelations
Definition: relation.h:108
struct RollupData RollupData
bool is_hashed
Definition: relation.h:1586
ParamPathInfo * param_info
Definition: relation.h:1049
struct EquivalenceMember EquivalenceMember
Index ec_sortref
Definition: relation.h:875
Definition: nodes.h:513
List * part_schemes
Definition: relation.h:269
Oid * sortopfamily
Definition: relation.h:738
struct SubqueryScanPath SubqueryScanPath
List * partial_pathlist
Definition: relation.h:601
Oid reltablespace
Definition: relation.h:724
Relids left_relids
Definition: relation.h:1874
List * join_rel_list
Definition: relation.h:215
bool ec_below_outer_join
Definition: relation.h:873
uint32 flags
Definition: relation.h:1251
bool hasNonSerial
Definition: relation.h:61
uint32 BlockNumber
Definition: block.h:31
EquivalenceClass * right_ec
Definition: relation.h:1896
List * cheapest_parameterized_paths
Definition: relation.h:605
List * minmax_aggs
Definition: relation.h:288
bool single_copy
Definition: relation.h:1364
bool hypothetical
Definition: relation.h:759
Index baserestrict_min_security
Definition: relation.h:647
UniquePathMethod umethod
Definition: relation.h:1350
struct WindowAggPath WindowAggPath
Path * subpath
Definition: relation.h:1324
List * indexclauses
Definition: relation.h:1124
NodeTag type
Definition: relation.h:580
double Selectivity
Definition: nodes.h:643
NodeTag type
Definition: relation.h:2164
Index ec_max_security
Definition: relation.h:877
bool hasNonPartial
Definition: relation.h:60
bool useridiscurrent
Definition: relation.h:634
AggSplit aggsplit
Definition: relation.h:1561
bool immediate
Definition: relation.h:758
QualCost transCost
Definition: relation.h:62
List * partitioned_rels
Definition: relation.h:1297
struct ProjectSetPath ProjectSetPath
Selectivity bitmapselectivity
Definition: relation.h:1167
double tuples
Definition: relation.h:729
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: relation.h:1609
UpperRelationKind
Definition: relation.h:71
List ** nullable_partexprs
Definition: relation.h:663
struct ResultPath ResultPath
AttrNumber * grouping_map
Definition: relation.h:287
List * fkey_list
Definition: relation.h:260
int tree_height
Definition: relation.h:730
double inner_rows_total
Definition: relation.h:1471
struct GatherMergePath GatherMergePath
bool hasRecursion
Definition: relation.h:308
double numGroups
Definition: relation.h:1562
double numGroups
Definition: relation.h:1639
List * mergeopfamilies
Definition: relation.h:1892
List * translated_vars
Definition: relation.h:2105
SetOpStrategy
Definition: nodes.h:791
Cost inner_rescan_run_cost
Definition: relation.h:2315
Oid parent_reltype
Definition: relation.h:2086
Relids syn_lefthand
Definition: relation.h:2021
List * rowMarks
Definition: relation.h:1662
int pk_strategy
Definition: relation.h:945
List * winpathkeys
Definition: relation.h:1624
struct PlaceHolderVar PlaceHolderVar
double numGroups
Definition: relation.h:1584
Cost startup
Definition: relation.h:45
double allvisfrac
Definition: relation.h:626
Relids outer_relids
Definition: relation.h:1868
signed int int32
Definition: c.h:302
static struct cvec * eclass(struct vars *v, chr c, int cases)
Definition: regc_locale.c:508
List * bitmapquals
Definition: relation.h:1166
Selectivity norm_selec
Definition: relation.h:1885
Path path
Definition: relation.h:1272
List * custom_private
Definition: relation.h:1254
JoinType
Definition: nodes.h:677
struct PlannerGlobal PlannerGlobal
int first_partial_path
Definition: relation.h:1278
WindowClause * winclause
Definition: relation.h:1623
struct RelOptInfo ** simple_rel_array
Definition: relation.h:179
List * bitmapquals
Definition: relation.h:1179
int num_workers
Definition: relation.h:1365
List * rootResultRelations
Definition: relation.h:111
List * multiexpr_params
Definition: relation.h:232
bool unique
Definition: relation.h:757
BlockNumber pages
Definition: relation.h:728
NodeTag pathtype
Definition: relation.h:1044
Relids syn_righthand
Definition: relation.h:2022
List * subpaths
Definition: relation.h:1275
PlannerInfo * subroot
Definition: relation.h:627
NodeTag type
Definition: relation.h:941
SetOpCmd cmd
Definition: relation.h:1634
bool dependsOnRole
Definition: relation.h:127
struct AggPath AggPath
NodeTag type
Definition: relation.h:1573
bool consider_startup
Definition: relation.h:591
Definition: dynahash.c:208
struct MaterialPath MaterialPath
Relids lateral_relids
Definition: relation.h:610
Cost per_tuple
Definition: relation.h:46
const struct CustomPathMethods * methods
Definition: relation.h:1255
List * indexquals
Definition: relation.h:1125
int wt_param_id
Definition: relation.h:311
double tuple_fraction
Definition: relation.h:294
Path * subpath
Definition: relation.h:1622
bool skip_mark_restore
Definition: relation.h:1453
RelOptInfo * rel
Definition: relation.h:725
bool amoptionalkey
Definition: relation.h:763
SpecialJoinInfo * sjinfo
Definition: relation.h:2287
List ** partexprs
Definition: relation.h:662
bool parallelModeNeeded
Definition: relation.h:131
Path path
Definition: relation.h:1311
struct AppendRelInfo AppendRelInfo
Relids phrels
Definition: relation.h:1953
Relids all_baserels
Definition: relation.h:196
bool pk_nulls_first
Definition: relation.h:946
Path * path
Definition: relation.h:2187
List * paramExecTypes
Definition: relation.h:117
bool hasDeletedRTEs
Definition: relation.h:304
Expr * phexpr
Definition: relation.h:1952
Relids param_source_rels
Definition: relation.h:2289
NodeTag type
Definition: relation.h:1003
struct PartitionSchemeData * PartitionScheme
Definition: relation.h:359
double limit_tuples
Definition: relation.h:295
EquivalenceMember * left_em
Definition: relation.h:1897
Cost indextotalcost
Definition: relation.h:1130
Cost startup_cost
Definition: relation.h:1057
List * semi_rhs_exprs
Definition: relation.h:2030
NodeTag type
Definition: relation.h:975
bool semi_can_hash
Definition: relation.h:2028
bool hasLateralRTEs
Definition: relation.h:303
Path * subpath
Definition: relation.h:1698
struct PlannerParamItem PlannerParamItem
List * joinrestrictinfo
Definition: relation.h:1397
bool parallelModeOK
Definition: relation.h:129
EquivalenceClass * parent_ec
Definition: relation.h:1881
bool partColsUpdated
Definition: relation.h:1681
bool can_join
Definition: relation.h:1853
RTEKind
Definition: parsenodes.h:943
int16 * parttyplen
Definition: relation.h:355
List * subroots
Definition: relation.h:1684
Bitmapset * rewindPlanIDs
Definition: relation.h:102
RelOptInfo * parent
Definition: relation.h:1046
List * uniq_exprs
Definition: relation.h:1352
Path * bitmapqual
Definition: relation.h:1154
bool outerjoin_delayed
Definition: relation.h:1851
Path path
Definition: relation.h:1530
List * ec_sources
Definition: relation.h:867
struct Path * cheapest_total_path
Definition: relation.h:603
Selectivity rightstartsel
Definition: relation.h:1931
List * curOuterParams
Definition: relation.h:316
struct SetOpPath SetOpPath
struct IndexOptInfo IndexOptInfo
Selectivity indexselectivity
Definition: relation.h:1131
List * subplans
Definition: relation.h:98
bool amcanorderbyop
Definition: relation.h:762
List * joininfo
Definition: relation.h:649
struct GroupPath GroupPath
Relids ec_relids
Definition: relation.h:869
PlannerGlobal * glob
Definition: relation.h:157
bool outer_is_left
Definition: relation.h:1902
struct FdwRoutine * fdwroutine
Definition: relation.h:636
List * left_join_clauses
Definition: relation.h:239
int nparts
Definition: relation.h:658
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: relation.h:247
struct GroupingSetsPath GroupingSetsPath
List * subpaths
Definition: relation.h:1683
List * groupClause
Definition: relation.h:1563
Index * sortgrouprefs
Definition: relation.h:977
List * mergeclause_list
Definition: relation.h:2285
unsigned int uint32
Definition: c.h:314
AttrNumber flagColIdx
Definition: relation.h:1637
Relids relids
Definition: relation.h:585
AggStrategy aggstrategy
Definition: relation.h:1597
Selectivity outer_selec
Definition: relation.h:1888
Path * subpath
Definition: relation.h:1363
struct TidPath TidPath
double total_table_pages
Definition: relation.h:292
struct LimitPath LimitPath
Selectivity bitmapselectivity
Definition: relation.h:1180
struct RecursiveUnionPath RecursiveUnionPath
RelOptInfo * rel
Definition: relation.h:815
int simple_rel_array_size
Definition: relation.h:180
int ncolumns
Definition: relation.h:733
bool amhasgetbitmap
Definition: relation.h:767
List * canon_pathkeys
Definition: relation.h:237
List * non_unique_for_rels
Definition: relation.h:642
List * ppilist
Definition: relation.h:600
Path path
Definition: relation.h:1250
Index relid
Definition: relation.h:613
Bitmapset * Relids
Definition: relation.h:28
List * sort_pathkeys
Definition: relation.h:267
RangeTblEntry ** simple_rte_array
Definition: relation.h:188
struct PlannerInfo * parent_root
Definition: relation.h:161
EquivalenceMember * right_em
Definition: relation.h:1898
Relids lateral_referencers
Definition: relation.h:621
Expr * clause
Definition: relation.h:1847
int numOrderedAggs
Definition: relation.h:59
Path * subpath
Definition: relation.h:1661
Oid serverid
Definition: relation.h:632
List * ec_opfamilies
Definition: relation.h:864
List * exprs
Definition: relation.h:976
struct ParamPathInfo ParamPathInfo
struct Path Path
List * window_pathkeys
Definition: relation.h:265
List * indrestrictinfo
Definition: relation.h:750
Relids direct_lateral_relids
Definition: relation.h:609
Path * outerjoinpath
Definition: relation.h:1394
List * invalItems
Definition: relation.h:115
NodeTag type
Definition: relation.h:153
struct MinMaxAggInfo MinMaxAggInfo
Relids nullable_relids
Definition: relation.h:1871
double inner_rows_total
Definition: relation.h:2326
bool delay_upper_joins
Definition: relation.h:2025
struct QualCost QualCost
List * indexorderbys
Definition: relation.h:1127
int rel_parallel_workers
Definition: relation.h:629
List * groupClause
Definition: relation.h:1532
List * append_rel_list
Definition: relation.h:252
Index lastPHId
Definition: relation.h:119
List * cte_plan_ids
Definition: relation.h:230
List * mmaggregates
Definition: relation.h:1608
Relids ph_lateral
Definition: relation.h:2169
List * partitioned_rels
Definition: relation.h:1680
Relids em_relids
Definition: relation.h:915
struct PartitionBoundInfoData * boundinfo
Definition: relation.h:659
List * tidquals
Definition: relation.h:1193
List * restrictlist
Definition: relation.h:2284
Path * subpath
Definition: relation.h:1531
unsigned int Index
Definition: c.h:431
struct ForeignPath ForeignPath
RTEKind rtekind
Definition: relation.h:615
List * indexlist
Definition: relation.h:622
List * init_plans
Definition: relation.h:228
List * in_operators
Definition: relation.h:1351
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct MergeScanSelCache MergeScanSelCache
struct RestrictInfo RestrictInfo
double rows
Definition: relation.h:588
bool hasPseudoConstantQuals
Definition: relation.h:306
bool amhasgettuple
Definition: relation.h:766
Cost finalCost
Definition: relation.h:63
List * distinct_pathkeys
Definition: relation.h:266
bool is_pushed_down
Definition: relation.h:1849
void * fdw_private
Definition: relation.h:637
Cost total_cost
Definition: relation.h:1058
NodeTag type
Definition: relation.h:721
Selectivity left_bucketsize
Definition: relation.h:1908
int firstFlag
Definition: relation.h:1638
double outer_skip_rows
Definition: relation.h:2320
List * pathkeys
Definition: relation.h:1060
struct GatherPath GatherPath
List * nonleafResultRelations
Definition: relation.h:110
Relids right_relids
Definition: relation.h:1875
BlockNumber pages
Definition: relation.h:624
Path path
Definition: relation.h:1387
ParamListInfo boundParams
Definition: relation.h:96
struct AggClauseCosts AggClauseCosts
Expr * target
Definition: relation.h:2185
List * pcinfo_list
Definition: relation.h:254
List * eq_classes
Definition: relation.h:235
List ** join_rel_level
Definition: relation.h:225
NodeTag type
Definition: relation.h:94
JoinPath NestPath
Definition: relation.h:1410
Path * subpath
Definition: relation.h:1503
double rows
Definition: relation.h:1056
bool parallel_safe
Definition: relation.h:1052
List * lateral_vars
Definition: relation.h:620
bool hasInheritedTarget
Definition: relation.h:300
List * quals
Definition: relation.h:1312
JoinType jointype
Definition: relation.h:2023
EquivalenceClass * pk_eclass
Definition: relation.h:943
Bitmapset * outer_params
Definition: relation.h:170
Selectivity left_mcvfreq
Definition: relation.h:1910
List * ppi_clauses
Definition: relation.h:1007
struct RelOptInfo ** part_rels
Definition: relation.h:660
struct Path * non_recursive_path
Definition: relation.h:312
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:422
Oid hashjoinoperator
Definition: relation.h:1905
NodeTag type
Definition: relation.h:1845
QualCost cost
Definition: relation.h:978
AggSplit
Definition: nodes.h:761
bool ec_has_volatile
Definition: relation.h:872
List * relationOids
Definition: relation.h:113
struct HashPath HashPath
List * subroots
Definition: relation.h:100
bool amsearcharray
Definition: relation.h:764
struct HTAB * join_rel_hash
Definition: relation.h:216
CostSelector
Definition: relation.h:34
struct JoinPath JoinPath
bool inner_unique
Definition: relation.h:1391
Index qual_security_level
Definition: relation.h:297
bool consider_parallel
Definition: relation.h:593
List * innersortkeys
Definition: relation.h:1452
Path * subpath
Definition: relation.h:1559
Oid * opcintype
Definition: relation.h:737
struct EquivalenceClass EquivalenceClass
List * partitioned_rels
Definition: relation.h:1274
struct PartitionSchemeData PartitionSchemeData
Index query_level
Definition: relation.h:159
Oid pk_opfamily
Definition: relation.h:944
struct JoinCostWorkspace JoinCostWorkspace
Path * subpath
Definition: relation.h:1376
struct SortPath SortPath
double ppi_rows
Definition: relation.h:1006
Path path
Definition: relation.h:1697
Path path
Definition: relation.h:1192
struct PartitionedChildRelInfo PartitionedChildRelInfo
Oid child_reltype
Definition: relation.h:2087
Oid * opfamily
Definition: relation.h:736
List * withCheckOptionLists
Definition: relation.h:1685
List * indexqualcols
Definition: relation.h:1126
List * finalrtable
Definition: relation.h:104
int width
Definition: relation.h:979
AggStrategy
Definition: nodes.h:739
Bitmapset * keys
Definition: relation.h:817
Index phlevelsup
Definition: relation.h:1955
Index lastRowMarkId
Definition: relation.h:121
AttrNumber max_attr
Definition: relation.h:617
Selectivity match_count
Definition: relation.h:2266
Selectivity right_bucketsize
Definition: relation.h:1909
EquivalenceClass * left_ec
Definition: relation.h:1895
Relids nullable_baserels
Definition: relation.h:204
struct MergeAppendPath MergeAppendPath
List * fdw_private
Definition: relation.h:1224
SetOpCmd
Definition: nodes.h:783
JoinType jointype
Definition: relation.h:1389
List * semi_operators
Definition: relation.h:2029
ScanDirection indexscandir
Definition: relation.h:1129
CmdType operation
Definition: relation.h:1676
List * placeholder_list
Definition: relation.h:258
List * resultRelations
Definition: relation.h:1682
struct StatisticExtInfo StatisticExtInfo
Size transitionSpace
Definition: relation.h:64
double numGroups
Definition: relation.h:1575
bool hashable
Definition: relation.h:1585
struct BitmapHeapPath BitmapHeapPath
bool hasHavingQual
Definition: relation.h:305
struct PathKey PathKey
JoinPath jpath
Definition: relation.h:1449
PartitionScheme part_scheme
Definition: relation.h:657
NodeTag type
Definition: relation.h:862
bool parallel_aware
Definition: relation.h:1051
int * indexkeys
Definition: relation.h:734
List * path_hashclauses
Definition: relation.h:1469
struct ProjectionPath ProjectionPath
UniquePathMethod
Definition: relation.h:1339
struct UpperUniquePath UpperUniquePath
List * initial_rels
Definition: relation.h:272
List * pathlist
Definition: relation.h:599
List * subpaths
Definition: relation.h:1298
Relids ppi_req_outer
Definition: relation.h:1005
MemoryContext planner_cxt
Definition: relation.h:290
struct MergePath MergePath
List * right_join_clauses
Definition: relation.h:243
Oid indexoid
Definition: relation.h:723
Index child_relid
Definition: relation.h:2078
bool * canreturn
Definition: relation.h:741
bool amsearchnulls
Definition: relation.h:765
Oid parent_reloid
Definition: relation.h:2112
bool * nulls_first
Definition: relation.h:740
Path * subpath
Definition: relation.h:1491
Path path
Definition: relation.h:1362
Index parent_relid
Definition: relation.h:2077
bool * reverse_sort
Definition: relation.h:739
double inner_skip_rows
Definition: relation.h:2321
List * processed_tlist
Definition: relation.h:284
List * indpred
Definition: relation.h:746
int32 * attr_widths
Definition: relation.h:619
Node * limitCount
Definition: relation.h:1700
List * finalrowmarks
Definition: relation.h:106
Definition: pg_list.h:45
Path path
Definition: relation.h:1516
struct PathTarget * reltarget
Definition: relation.h:596
Relids min_lefthand
Definition: relation.h:2019
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: relation.h:646
List * subplan_params
Definition: relation.h:628
Path path
Definition: relation.h:1632
NodeTag type
Definition: relation.h:2181
Path path
Definition: relation.h:1348
CmdType
Definition: nodes.h:653
List * gsets_data
Definition: relation.h:1583
Path path
Definition: relation.h:1558
struct RelOptInfo RelOptInfo
double limit_tuples
Definition: relation.h:1299
struct EquivalenceClass * ec_merged
Definition: relation.h:878
Selectivity rightendsel
Definition: relation.h:1932
bool amcanparallel
Definition: relation.h:768
double Cost
Definition: nodes.h:644
List * scansel_cache
Definition: relation.h:1899
Selectivity leftstartsel
Definition: relation.h:1929
List * ec_members
Definition: relation.h:866
List * indexprs
Definition: relation.h:745
Relids top_parent_relids
Definition: relation.h:654
bool transientPlan
Definition: relation.h:125
List * gsets
Definition: relation.h:1582
Path * subpath
Definition: relation.h:1349
PlannerInfo * subroot
Definition: relation.h:2186
struct BitmapAndPath BitmapAndPath
AttrNumber min_attr
Definition: relation.h:616