PostgreSQL Source Code  git master
pathnodes.h
Go to the documentation of this file.
1 /*-------------------------------------------------------------------------
2  *
3  * pathnodes.h
4  * Definitions for planner's internal data structures, especially Paths.
5  *
6  *
7  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/nodes/pathnodes.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef PATHNODES_H
15 #define PATHNODES_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  QualCost 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_PARTIAL_GROUP_AGG, /* result of partial grouping/aggregation, if
75  * any */
76  UPPERREL_GROUP_AGG, /* result of grouping/aggregation, if any */
77  UPPERREL_WINDOW, /* result of window functions, if any */
78  UPPERREL_DISTINCT, /* result of "SELECT DISTINCT", if any */
79  UPPERREL_ORDERED, /* result of ORDER BY, if any */
80  UPPERREL_FINAL /* result of any remaining top-level actions */
81  /* NB: UPPERREL_FINAL must be last enum entry; it's used to size arrays */
83 
84 /*
85  * This enum identifies which type of relation is being planned through the
86  * inheritance planner. INHKIND_NONE indicates the inheritance planner
87  * was not used.
88  */
89 typedef enum InheritanceKind
90 {
95 
96 /*----------
97  * PlannerGlobal
98  * Global information for planning/optimization
99  *
100  * PlannerGlobal holds state for an entire planner invocation; this state
101  * is shared across all levels of sub-Queries that exist in the command being
102  * planned.
103  *----------
104  */
105 typedef struct PlannerGlobal
106 {
108 
109  ParamListInfo boundParams; /* Param values provided to planner() */
110 
111  List *subplans; /* Plans for SubPlan nodes */
112 
113  List *subroots; /* PlannerInfos for SubPlan nodes */
114 
115  Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
116 
117  List *finalrtable; /* "flat" rangetable for executor */
118 
119  List *finalrowmarks; /* "flat" list of PlanRowMarks */
120 
121  List *resultRelations; /* "flat" list of integer RT indexes */
122 
123  List *rootResultRelations; /* "flat" list of integer RT indexes */
124 
125  List *relationOids; /* OIDs of relations the plan depends on */
126 
127  List *invalItems; /* other dependencies, as PlanInvalItems */
128 
129  List *paramExecTypes; /* type OIDs for PARAM_EXEC Params */
130 
131  Index lastPHId; /* highest PlaceHolderVar ID assigned */
132 
133  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
134 
135  int lastPlanNodeId; /* highest plan node ID assigned */
136 
137  bool transientPlan; /* redo plan when TransactionXmin changes? */
138 
139  bool dependsOnRole; /* is plan specific to current role? */
140 
141  bool parallelModeOK; /* parallel mode potentially OK? */
142 
143  bool parallelModeNeeded; /* parallel mode actually required? */
144 
145  char maxParallelHazard; /* worst PROPARALLEL hazard level */
146 
147  PartitionDirectory partition_directory; /* partition descriptors */
148 } PlannerGlobal;
149 
150 /* macro for fetching the Plan associated with a SubPlan node */
151 #define planner_subplan_get_plan(root, subplan) \
152  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
153 
154 
155 /*----------
156  * PlannerInfo
157  * Per-query information for planning/optimization
158  *
159  * This struct is conventionally called "root" in all the planner routines.
160  * It holds links to all of the planner's working state, in addition to the
161  * original Query. Note that at present the planner extensively modifies
162  * the passed-in Query data structure; someday that should stop.
163  *
164  * For reasons explained in optimizer/optimizer.h, we define the typedef
165  * either here or in that header, whichever is read first.
166  *----------
167  */
168 #ifndef HAVE_PLANNERINFO_TYPEDEF
169 typedef struct PlannerInfo PlannerInfo;
170 #define HAVE_PLANNERINFO_TYPEDEF 1
171 #endif
172 
174 {
176 
177  Query *parse; /* the Query being planned */
178 
179  PlannerGlobal *glob; /* global info for current planner run */
180 
181  Index query_level; /* 1 at the outermost Query */
182 
183  PlannerInfo *parent_root; /* NULL at outermost Query */
184 
185  /*
186  * plan_params contains the expressions that this query level needs to
187  * make available to a lower query level that is currently being planned.
188  * outer_params contains the paramIds of PARAM_EXEC Params that outer
189  * query levels will make available to this query level.
190  */
191  List *plan_params; /* list of PlannerParamItems, see below */
193 
194  /*
195  * simple_rel_array holds pointers to "base rels" and "other rels" (see
196  * comments for RelOptInfo for more info). It is indexed by rangetable
197  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
198  * does not correspond to a base relation, such as a join RTE or an
199  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
200  */
201  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
202  int simple_rel_array_size; /* allocated size of array */
203 
204  /*
205  * simple_rte_array is the same length as simple_rel_array and holds
206  * pointers to the associated rangetable entries. Using this is a shade
207  * faster than using rt_fetch(), mostly due to fewer indirections.
208  */
209  RangeTblEntry **simple_rte_array; /* rangetable as an array */
210 
211  /*
212  * append_rel_array is the same length as the above arrays, and holds
213  * pointers to the corresponding AppendRelInfo entry indexed by
214  * child_relid, or NULL if the rel is not an appendrel child. The array
215  * itself is not allocated if append_rel_list is empty.
216  */
218 
219  /*
220  * all_baserels is a Relids set of all base relids (but not "other"
221  * relids) in the query; that is, the Relids identifier of the final join
222  * we need to form. This is computed in make_one_rel, just before we
223  * start making Paths.
224  */
226 
227  /*
228  * nullable_baserels is a Relids set of base relids that are nullable by
229  * some outer join in the jointree; these are rels that are potentially
230  * nullable below the WHERE clause, SELECT targetlist, etc. This is
231  * computed in deconstruct_jointree.
232  */
234 
235  /*
236  * join_rel_list is a list of all join-relation RelOptInfos we have
237  * considered in this planning run. For small problems we just scan the
238  * list to do lookups, but when there are many join relations we build a
239  * hash table for faster lookups. The hash table is present and valid
240  * when join_rel_hash is not NULL. Note that we still maintain the list
241  * even when using the hash table for lookups; this simplifies life for
242  * GEQO.
243  */
244  List *join_rel_list; /* list of join-relation RelOptInfos */
245  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
246 
247  /*
248  * When doing a dynamic-programming-style join search, join_rel_level[k]
249  * is a list of all join-relation RelOptInfos of level k, and
250  * join_cur_level is the current level. New join-relation RelOptInfos are
251  * automatically added to the join_rel_level[join_cur_level] list.
252  * join_rel_level is NULL if not in use.
253  */
254  List **join_rel_level; /* lists of join-relation RelOptInfos */
255  int join_cur_level; /* index of list being extended */
256 
257  List *init_plans; /* init SubPlans for query */
258 
259  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
260 
261  List *multiexpr_params; /* List of Lists of Params for MULTIEXPR
262  * subquery outputs */
263 
264  List *eq_classes; /* list of active EquivalenceClasses */
265 
266  bool ec_merging_done; /* set true once ECs are canonical */
267 
268  List *canon_pathkeys; /* list of "canonical" PathKeys */
269 
270  List *left_join_clauses; /* list of RestrictInfos for mergejoinable
271  * outer join clauses w/nonnullable var on
272  * left */
273 
274  List *right_join_clauses; /* list of RestrictInfos for mergejoinable
275  * outer join clauses w/nonnullable var on
276  * right */
277 
278  List *full_join_clauses; /* list of RestrictInfos for mergejoinable
279  * full join clauses */
280 
281  List *join_info_list; /* list of SpecialJoinInfos */
282 
283  /*
284  * Note: for AppendRelInfos describing partitions of a partitioned table,
285  * we guarantee that partitions that come earlier in the partitioned
286  * table's PartitionDesc will appear earlier in append_rel_list.
287  */
288  List *append_rel_list; /* list of AppendRelInfos */
289 
290  List *rowMarks; /* list of PlanRowMarks */
291 
292  List *placeholder_list; /* list of PlaceHolderInfos */
293 
294  List *fkey_list; /* list of ForeignKeyOptInfos */
295 
296  List *query_pathkeys; /* desired pathkeys for query_planner() */
297 
298  List *group_pathkeys; /* groupClause pathkeys, if any */
299  List *window_pathkeys; /* pathkeys of bottom window, if any */
300  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
301  List *sort_pathkeys; /* sortClause pathkeys, if any */
302 
303  List *part_schemes; /* Canonicalised partition schemes used in the
304  * query. */
305 
306  List *initial_rels; /* RelOptInfos we are now trying to join */
307 
308  /* Use fetch_upper_rel() to get any particular upper rel */
309  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
310 
311  /* Result tlists chosen by grouping_planner for upper-stage processing */
312  struct PathTarget *upper_targets[UPPERREL_FINAL + 1];
313 
314  /*
315  * The fully-processed targetlist is kept here. It differs from
316  * parse->targetList in that (for INSERT and UPDATE) it's been reordered
317  * to match the target table, and defaults have been filled in. Also,
318  * additional resjunk targets may be present. preprocess_targetlist()
319  * does most of this work, but note that more resjunk targets can get
320  * added during appendrel expansion. (Hence, upper_targets mustn't get
321  * set up till after that.)
322  */
324 
325  /* Fields filled during create_plan() for use in setrefs.c */
326  AttrNumber *grouping_map; /* for GroupingFunc fixup */
327  List *minmax_aggs; /* List of MinMaxAggInfos */
328 
329  MemoryContext planner_cxt; /* context holding PlannerInfo */
330 
331  double total_table_pages; /* # of pages in all non-dummy tables of
332  * query */
333 
334  double tuple_fraction; /* tuple_fraction passed to query_planner */
335  double limit_tuples; /* limit_tuples passed to query_planner */
336 
337  Index qual_security_level; /* minimum security_level for quals */
338  /* Note: qual_security_level is zero if there are no securityQuals */
339 
340  InheritanceKind inhTargetKind; /* indicates if the target relation is an
341  * inheritance child or partition or a
342  * partitioned table */
343  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
344  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
345  bool hasHavingQual; /* true if havingQual was non-null */
346  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
347  * pseudoconstant = true */
348  bool hasRecursion; /* true if planning a recursive WITH item */
349 
350  /* These fields are used only when hasRecursion is true: */
351  int wt_param_id; /* PARAM_EXEC ID for the work table */
352  struct Path *non_recursive_path; /* a path for non-recursive term */
353 
354  /* These fields are workspace for createplan.c */
355  Relids curOuterRels; /* outer rels above current node */
356  List *curOuterParams; /* not-yet-assigned NestLoopParams */
357 
358  /* optional private data for join_search_hook, e.g., GEQO */
360 
361  /* Does this query modify any partition key columns? */
363 };
364 
365 
366 /*
367  * In places where it's known that simple_rte_array[] must have been prepared
368  * already, we just index into it to fetch RTEs. In code that might be
369  * executed before or after entering query_planner(), use this macro.
370  */
371 #define planner_rt_fetch(rti, root) \
372  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
373  rt_fetch(rti, (root)->parse->rtable))
374 
375 /*
376  * If multiple relations are partitioned the same way, all such partitions
377  * will have a pointer to the same PartitionScheme. A list of PartitionScheme
378  * objects is attached to the PlannerInfo. By design, the partition scheme
379  * incorporates only the general properties of the partition method (LIST vs.
380  * RANGE, number of partitioning columns and the type information for each)
381  * and not the specific bounds.
382  *
383  * We store the opclass-declared input data types instead of the partition key
384  * datatypes since the former rather than the latter are used to compare
385  * partition bounds. Since partition key data types and the opclass declared
386  * input data types are expected to be binary compatible (per ResolveOpClass),
387  * both of those should have same byval and length properties.
388  */
389 typedef struct PartitionSchemeData
390 {
391  char strategy; /* partition strategy */
392  int16 partnatts; /* number of partition attributes */
393  Oid *partopfamily; /* OIDs of operator families */
394  Oid *partopcintype; /* OIDs of opclass declared input data types */
395  Oid *partcollation; /* OIDs of partitioning collations */
396 
397  /* Cached information about partition key data types. */
400 
401  /* Cached information about partition comparison functions. */
404 
406 
407 /*----------
408  * RelOptInfo
409  * Per-relation information for planning/optimization
410  *
411  * For planning purposes, a "base rel" is either a plain relation (a table)
412  * or the output of a sub-SELECT or function that appears in the range table.
413  * In either case it is uniquely identified by an RT index. A "joinrel"
414  * is the joining of two or more base rels. A joinrel is identified by
415  * the set of RT indexes for its component baserels. We create RelOptInfo
416  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
417  * simple_rel_array and join_rel_list respectively.
418  *
419  * Note that there is only one joinrel for any given set of component
420  * baserels, no matter what order we assemble them in; so an unordered
421  * set is the right datatype to identify it with.
422  *
423  * We also have "other rels", which are like base rels in that they refer to
424  * single RT indexes; but they are not part of the join tree, and are given
425  * a different RelOptKind to identify them.
426  * Currently the only kind of otherrels are those made for member relations
427  * of an "append relation", that is an inheritance set or UNION ALL subquery.
428  * An append relation has a parent RTE that is a base rel, which represents
429  * the entire append relation. The member RTEs are otherrels. The parent
430  * is present in the query join tree but the members are not. The member
431  * RTEs and otherrels are used to plan the scans of the individual tables or
432  * subqueries of the append set; then the parent baserel is given Append
433  * and/or MergeAppend paths comprising the best paths for the individual
434  * member rels. (See comments for AppendRelInfo for more information.)
435  *
436  * At one time we also made otherrels to represent join RTEs, for use in
437  * handling join alias Vars. Currently this is not needed because all join
438  * alias Vars are expanded to non-aliased form during preprocess_expression.
439  *
440  * We also have relations representing joins between child relations of
441  * different partitioned tables. These relations are not added to
442  * join_rel_level lists as they are not joined directly by the dynamic
443  * programming algorithm.
444  *
445  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
446  * that describe post-scan/join processing steps, such as aggregation.
447  * Many of the fields in these RelOptInfos are meaningless, but their Path
448  * fields always hold Paths showing ways to do that processing step.
449  *
450  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
451  * that we have proven we don't need to join after all.
452  *
453  * Parts of this data structure are specific to various scan and join
454  * mechanisms. It didn't seem worth creating new node types for them.
455  *
456  * relids - Set of base-relation identifiers; it is a base relation
457  * if there is just one, a join relation if more than one
458  * rows - estimated number of tuples in the relation after restriction
459  * clauses have been applied (ie, output rows of a plan for it)
460  * consider_startup - true if there is any value in keeping plain paths for
461  * this rel on the basis of having cheap startup cost
462  * consider_param_startup - the same for parameterized paths
463  * reltarget - Default Path output tlist for this rel; normally contains
464  * Var and PlaceHolderVar nodes for the values we need to
465  * output from this relation.
466  * List is in no particular order, but all rels of an
467  * appendrel set must use corresponding orders.
468  * NOTE: in an appendrel child relation, may contain
469  * arbitrary expressions pulled up from a subquery!
470  * pathlist - List of Path nodes, one for each potentially useful
471  * method of generating the relation
472  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
473  * cheapest_startup_path - the pathlist member with lowest startup cost
474  * (regardless of ordering) among the unparameterized paths;
475  * or NULL if there is no unparameterized path
476  * cheapest_total_path - the pathlist member with lowest total cost
477  * (regardless of ordering) among the unparameterized paths;
478  * or if there is no unparameterized path, the path with lowest
479  * total cost among the paths with minimum parameterization
480  * cheapest_unique_path - for caching cheapest path to produce unique
481  * (no duplicates) output from relation; NULL if not yet requested
482  * cheapest_parameterized_paths - best paths for their parameterizations;
483  * always includes cheapest_total_path, even if that's unparameterized
484  * direct_lateral_relids - rels this rel has direct LATERAL references to
485  * lateral_relids - required outer rels for LATERAL, as a Relids set
486  * (includes both direct and indirect lateral references)
487  *
488  * If the relation is a base relation it will have these fields set:
489  *
490  * relid - RTE index (this is redundant with the relids field, but
491  * is provided for convenience of access)
492  * rtekind - copy of RTE's rtekind field
493  * min_attr, max_attr - range of valid AttrNumbers for rel
494  * attr_needed - array of bitmapsets indicating the highest joinrel
495  * in which each attribute is needed; if bit 0 is set then
496  * the attribute is needed as part of final targetlist
497  * attr_widths - cache space for per-attribute width estimates;
498  * zero means not computed yet
499  * lateral_vars - lateral cross-references of rel, if any (list of
500  * Vars and PlaceHolderVars)
501  * lateral_referencers - relids of rels that reference this one laterally
502  * (includes both direct and indirect lateral references)
503  * indexlist - list of IndexOptInfo nodes for relation's indexes
504  * (always NIL if it's not a table)
505  * pages - number of disk pages in relation (zero if not a table)
506  * tuples - number of tuples in relation (not considering restrictions)
507  * allvisfrac - fraction of disk pages that are marked all-visible
508  * eclass_indexes - EquivalenceClasses that mention this rel (filled
509  * only after EC merging is complete)
510  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
511  * subplan_params - list of PlannerParamItems to be passed to subquery
512  *
513  * Note: for a subquery, tuples and subroot are not set immediately
514  * upon creation of the RelOptInfo object; they are filled in when
515  * set_subquery_pathlist processes the object.
516  *
517  * For otherrels that are appendrel members, these fields are filled
518  * in just as for a baserel, except we don't bother with lateral_vars.
519  *
520  * If the relation is either a foreign table or a join of foreign tables that
521  * all belong to the same foreign server and are assigned to the same user to
522  * check access permissions as (cf checkAsUser), these fields will be set:
523  *
524  * serverid - OID of foreign server, if foreign table (else InvalidOid)
525  * userid - OID of user to check access as (InvalidOid means current user)
526  * useridiscurrent - we've assumed that userid equals current user
527  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
528  * fdw_private - private state for FDW, if foreign table (else NULL)
529  *
530  * Two fields are used to cache knowledge acquired during the join search
531  * about whether this rel is provably unique when being joined to given other
532  * relation(s), ie, it can have at most one row matching any given row from
533  * that join relation. Currently we only attempt such proofs, and thus only
534  * populate these fields, for base rels; but someday they might be used for
535  * join rels too:
536  *
537  * unique_for_rels - list of Relid sets, each one being a set of other
538  * rels for which this one has been proven unique
539  * non_unique_for_rels - list of Relid sets, each one being a set of
540  * other rels for which we have tried and failed to prove
541  * this one unique
542  *
543  * The presence of the following fields depends on the restrictions
544  * and joins that the relation participates in:
545  *
546  * baserestrictinfo - List of RestrictInfo nodes, containing info about
547  * each non-join qualification clause in which this relation
548  * participates (only used for base rels)
549  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
550  * clauses at a single tuple (only used for base rels)
551  * baserestrict_min_security - Smallest security_level found among
552  * clauses in baserestrictinfo
553  * joininfo - List of RestrictInfo nodes, containing info about each
554  * join clause in which this relation participates (but
555  * note this excludes clauses that might be derivable from
556  * EquivalenceClasses)
557  * has_eclass_joins - flag that EquivalenceClass joins are possible
558  *
559  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
560  * base rels, because for a join rel the set of clauses that are treated as
561  * restrict clauses varies depending on which sub-relations we choose to join.
562  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
563  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
564  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
565  * and should not be processed again at the level of {1 2 3}.) Therefore,
566  * the restrictinfo list in the join case appears in individual JoinPaths
567  * (field joinrestrictinfo), not in the parent relation. But it's OK for
568  * the RelOptInfo to store the joininfo list, because that is the same
569  * for a given rel no matter how we form it.
570  *
571  * We store baserestrictcost in the RelOptInfo (for base relations) because
572  * we know we will need it at least once (to price the sequential scan)
573  * and may need it multiple times to price index scans.
574  *
575  * If the relation is partitioned, these fields will be set:
576  *
577  * part_scheme - Partitioning scheme of the relation
578  * nparts - Number of partitions
579  * boundinfo - Partition bounds
580  * partition_qual - Partition constraint if not the root
581  * part_rels - RelOptInfos for each partition
582  * partexprs, nullable_partexprs - Partition key expressions
583  * partitioned_child_rels - RT indexes of unpruned partitions of
584  * this relation that are partitioned tables
585  * themselves, in hierarchical order
586  *
587  * Note: A base relation always has only one set of partition keys, but a join
588  * relation may have as many sets of partition keys as the number of relations
589  * being joined. partexprs and nullable_partexprs are arrays containing
590  * part_scheme->partnatts elements each. Each of these elements is a list of
591  * partition key expressions. For a base relation each list in partexprs
592  * contains only one expression and nullable_partexprs is not populated. For a
593  * join relation, partexprs and nullable_partexprs contain partition key
594  * expressions from non-nullable and nullable relations resp. Lists at any
595  * given position in those arrays together contain as many elements as the
596  * number of joining relations.
597  *----------
598  */
599 typedef enum RelOptKind
600 {
608 } RelOptKind;
609 
610 /*
611  * Is the given relation a simple relation i.e a base or "other" member
612  * relation?
613  */
614 #define IS_SIMPLE_REL(rel) \
615  ((rel)->reloptkind == RELOPT_BASEREL || \
616  (rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
617 
618 /* Is the given relation a join relation? */
619 #define IS_JOIN_REL(rel) \
620  ((rel)->reloptkind == RELOPT_JOINREL || \
621  (rel)->reloptkind == RELOPT_OTHER_JOINREL)
622 
623 /* Is the given relation an upper relation? */
624 #define IS_UPPER_REL(rel) \
625  ((rel)->reloptkind == RELOPT_UPPER_REL || \
626  (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
627 
628 /* Is the given relation an "other" relation? */
629 #define IS_OTHER_REL(rel) \
630  ((rel)->reloptkind == RELOPT_OTHER_MEMBER_REL || \
631  (rel)->reloptkind == RELOPT_OTHER_JOINREL || \
632  (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
633 
634 typedef struct RelOptInfo
635 {
637 
639 
640  /* all relations included in this RelOptInfo */
641  Relids relids; /* set of base relids (rangetable indexes) */
642 
643  /* size estimates generated by planner */
644  double rows; /* estimated number of result tuples */
645 
646  /* per-relation planner control flags */
647  bool consider_startup; /* keep cheap-startup-cost paths? */
648  bool consider_param_startup; /* ditto, for parameterized paths? */
649  bool consider_parallel; /* consider parallel paths? */
650 
651  /* default result targetlist for Paths scanning this relation */
652  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
653 
654  /* materialization information */
655  List *pathlist; /* Path structures */
656  List *ppilist; /* ParamPathInfos used in pathlist */
657  List *partial_pathlist; /* partial Paths */
662 
663  /* parameterization information needed for both base rels and join rels */
664  /* (see also lateral_vars and lateral_referencers) */
665  Relids direct_lateral_relids; /* rels directly laterally referenced */
666  Relids lateral_relids; /* minimum parameterization of rel */
667 
668  /* information about a base rel (not set for join rels!) */
670  Oid reltablespace; /* containing tablespace */
671  RTEKind rtekind; /* RELATION, SUBQUERY, FUNCTION, etc */
672  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
673  AttrNumber max_attr; /* largest attrno of rel */
674  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
675  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
676  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
677  Relids lateral_referencers; /* rels that reference me laterally */
678  List *indexlist; /* list of IndexOptInfo */
679  List *statlist; /* list of StatisticExtInfo */
680  BlockNumber pages; /* size estimates derived from pg_class */
681  double tuples;
682  double allvisfrac;
683  Bitmapset *eclass_indexes; /* Indexes in PlannerInfo's eq_classes list of
684  * ECs that mention this rel */
685  PlannerInfo *subroot; /* if subquery */
686  List *subplan_params; /* if subquery */
687  int rel_parallel_workers; /* wanted number of parallel workers */
688 
689  /* Information about foreign tables and foreign joins */
690  Oid serverid; /* identifies server for the table or join */
691  Oid userid; /* identifies user to check access as */
692  bool useridiscurrent; /* join is only valid for current user */
693  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
695  void *fdw_private;
696 
697  /* cache space for remembering if we have proven this relation unique */
698  List *unique_for_rels; /* known unique for these other relid
699  * set(s) */
700  List *non_unique_for_rels; /* known not unique for these set(s) */
701 
702  /* used by various scans and joins: */
703  List *baserestrictinfo; /* RestrictInfo structures (if base rel) */
704  QualCost baserestrictcost; /* cost of evaluating the above */
705  Index baserestrict_min_security; /* min security_level found in
706  * baserestrictinfo */
707  List *joininfo; /* RestrictInfo structures for join clauses
708  * involving this rel */
709  bool has_eclass_joins; /* T means joininfo is incomplete */
710 
711  /* used by partitionwise joins: */
712  bool consider_partitionwise_join; /* consider partitionwise join
713  * paths? (if partitioned rel) */
714  Relids top_parent_relids; /* Relids of topmost parents (if "other"
715  * rel) */
716 
717  /* used for partitioned relations */
718  PartitionScheme part_scheme; /* Partitioning scheme. */
719  int nparts; /* number of partitions */
720  struct PartitionBoundInfoData *boundinfo; /* Partition bounds */
721  List *partition_qual; /* partition constraint */
722  struct RelOptInfo **part_rels; /* Array of RelOptInfos of partitions,
723  * stored in the same order of bounds */
724  List **partexprs; /* Non-nullable partition key expressions. */
725  List **nullable_partexprs; /* Nullable partition key expressions. */
726  List *partitioned_child_rels; /* List of RT indexes. */
727 } RelOptInfo;
728 
729 /*
730  * Is given relation partitioned?
731  *
732  * It's not enough to test whether rel->part_scheme is set, because it might
733  * be that the basic partitioning properties of the input relations matched
734  * but the partition bounds did not. Also, if we are able to prove a rel
735  * dummy (empty), we should henceforth treat it as unpartitioned.
736  */
737 #define IS_PARTITIONED_REL(rel) \
738  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
739  (rel)->part_rels && !IS_DUMMY_REL(rel))
740 
741 /*
742  * Convenience macro to make sure that a partitioned relation has all the
743  * required members set.
744  */
745 #define REL_HAS_ALL_PART_PROPS(rel) \
746  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
747  (rel)->part_rels && (rel)->partexprs && (rel)->nullable_partexprs)
748 
749 /*
750  * IndexOptInfo
751  * Per-index information for planning/optimization
752  *
753  * indexkeys[], indexcollations[] each have ncolumns entries.
754  * opfamily[], and opcintype[] each have nkeycolumns entries. They do
755  * not contain any information about included attributes.
756  *
757  * sortopfamily[], reverse_sort[], and nulls_first[] have
758  * nkeycolumns entries, if the index is ordered; but if it is unordered,
759  * those pointers are NULL.
760  *
761  * Zeroes in the indexkeys[] array indicate index columns that are
762  * expressions; there is one element in indexprs for each such column.
763  *
764  * For an ordered index, reverse_sort[] and nulls_first[] describe the
765  * sort ordering of a forward indexscan; we can also consider a backward
766  * indexscan, which will generate the reverse ordering.
767  *
768  * The indexprs and indpred expressions have been run through
769  * prepqual.c and eval_const_expressions() for ease of matching to
770  * WHERE clauses. indpred is in implicit-AND form.
771  *
772  * indextlist is a TargetEntry list representing the index columns.
773  * It provides an equivalent base-relation Var for each simple column,
774  * and links to the matching indexprs element for each expression column.
775  *
776  * While most of these fields are filled when the IndexOptInfo is created
777  * (by plancat.c), indrestrictinfo and predOK are set later, in
778  * check_index_predicates().
779  */
780 #ifndef HAVE_INDEXOPTINFO_TYPEDEF
781 typedef struct IndexOptInfo IndexOptInfo;
782 #define HAVE_INDEXOPTINFO_TYPEDEF 1
783 #endif
784 
786 {
788 
789  Oid indexoid; /* OID of the index relation */
790  Oid reltablespace; /* tablespace of index (not table) */
791  RelOptInfo *rel; /* back-link to index's table */
792 
793  /* index-size statistics (from pg_class and elsewhere) */
794  BlockNumber pages; /* number of disk pages in index */
795  double tuples; /* number of index tuples in index */
796  int tree_height; /* index tree height, or -1 if unknown */
797 
798  /* index descriptor information */
799  int ncolumns; /* number of columns in index */
800  int nkeycolumns; /* number of key columns in index */
801  int *indexkeys; /* column numbers of index's attributes both
802  * key and included columns, or 0 */
803  Oid *indexcollations; /* OIDs of collations of index columns */
804  Oid *opfamily; /* OIDs of operator families for columns */
805  Oid *opcintype; /* OIDs of opclass declared input data types */
806  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
807  bool *reverse_sort; /* is sort order descending? */
808  bool *nulls_first; /* do NULLs come first in the sort order? */
809  bool *canreturn; /* which index cols can be returned in an
810  * index-only scan? */
811  Oid relam; /* OID of the access method (in pg_am) */
812 
813  List *indexprs; /* expressions for non-simple index columns */
814  List *indpred; /* predicate if a partial index, else NIL */
815 
816  List *indextlist; /* targetlist representing index columns */
817 
818  List *indrestrictinfo; /* parent relation's baserestrictinfo
819  * list, less any conditions implied by
820  * the index's predicate (unless it's a
821  * target rel, see comments in
822  * check_index_predicates()) */
823 
824  bool predOK; /* true if index predicate matches query */
825  bool unique; /* true if a unique index */
826  bool immediate; /* is uniqueness enforced immediately? */
827  bool hypothetical; /* true if index doesn't really exist */
828 
829  /* Remaining fields are copied from the index AM's API struct: */
830  bool amcanorderbyop; /* does AM support order by operator result? */
831  bool amoptionalkey; /* can query omit key for the first column? */
832  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
833  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
834  bool amhasgettuple; /* does AM have amgettuple interface? */
835  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
836  bool amcanparallel; /* does AM support parallel scan? */
837  /* Rather than include amapi.h here, we declare amcostestimate like this */
838  void (*amcostestimate) (); /* AM's cost estimator */
839 };
840 
841 /*
842  * ForeignKeyOptInfo
843  * Per-foreign-key information for planning/optimization
844  *
845  * The per-FK-column arrays can be fixed-size because we allow at most
846  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
847  * nkeys valid entries.
848  */
849 typedef struct ForeignKeyOptInfo
850 {
852 
853  /* Basic data about the foreign key (fetched from catalogs): */
854  Index con_relid; /* RT index of the referencing table */
855  Index ref_relid; /* RT index of the referenced table */
856  int nkeys; /* number of columns in the foreign key */
857  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
858  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
859  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
860 
861  /* Derived info about whether FK's equality conditions match the query: */
862  int nmatched_ec; /* # of FK cols matched by ECs */
863  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
864  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
865  /* Pointer to eclass matching each column's condition, if there is one */
867  /* List of non-EC RestrictInfos matching each column's condition */
870 
871 /*
872  * StatisticExtInfo
873  * Information about extended statistics for planning/optimization
874  *
875  * Each pg_statistic_ext row is represented by one or more nodes of this
876  * type, or even zero if ANALYZE has not computed them.
877  */
878 typedef struct StatisticExtInfo
879 {
881 
882  Oid statOid; /* OID of the statistics row */
883  RelOptInfo *rel; /* back-link to statistic's table */
884  char kind; /* statistic kind of this entry */
885  Bitmapset *keys; /* attnums of the columns covered */
887 
888 /*
889  * EquivalenceClasses
890  *
891  * Whenever we can determine that a mergejoinable equality clause A = B is
892  * not delayed by any outer join, we create an EquivalenceClass containing
893  * the expressions A and B to record this knowledge. If we later find another
894  * equivalence B = C, we add C to the existing EquivalenceClass; this may
895  * require merging two existing EquivalenceClasses. At the end of the qual
896  * distribution process, we have sets of values that are known all transitively
897  * equal to each other, where "equal" is according to the rules of the btree
898  * operator family(s) shown in ec_opfamilies, as well as the collation shown
899  * by ec_collation. (We restrict an EC to contain only equalities whose
900  * operators belong to the same set of opfamilies. This could probably be
901  * relaxed, but for now it's not worth the trouble, since nearly all equality
902  * operators belong to only one btree opclass anyway. Similarly, we suppose
903  * that all or none of the input datatypes are collatable, so that a single
904  * collation value is sufficient.)
905  *
906  * We also use EquivalenceClasses as the base structure for PathKeys, letting
907  * us represent knowledge about different sort orderings being equivalent.
908  * Since every PathKey must reference an EquivalenceClass, we will end up
909  * with single-member EquivalenceClasses whenever a sort key expression has
910  * not been equivalenced to anything else. It is also possible that such an
911  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
912  * which is a case that can't arise otherwise since clauses containing
913  * volatile functions are never considered mergejoinable. We mark such
914  * EquivalenceClasses specially to prevent them from being merged with
915  * ordinary EquivalenceClasses. Also, for volatile expressions we have
916  * to be careful to match the EquivalenceClass to the correct targetlist
917  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
918  * So we record the SortGroupRef of the originating sort clause.
919  *
920  * We allow equality clauses appearing below the nullable side of an outer join
921  * to form EquivalenceClasses, but these have a slightly different meaning:
922  * the included values might be all NULL rather than all the same non-null
923  * values. See src/backend/optimizer/README for more on that point.
924  *
925  * NB: if ec_merged isn't NULL, this class has been merged into another, and
926  * should be ignored in favor of using the pointed-to class.
927  */
928 typedef struct EquivalenceClass
929 {
931 
932  List *ec_opfamilies; /* btree operator family OIDs */
933  Oid ec_collation; /* collation, if datatypes are collatable */
934  List *ec_members; /* list of EquivalenceMembers */
935  List *ec_sources; /* list of generating RestrictInfos */
936  List *ec_derives; /* list of derived RestrictInfos */
937  Relids ec_relids; /* all relids appearing in ec_members, except
938  * for child members (see below) */
939  bool ec_has_const; /* any pseudoconstants in ec_members? */
940  bool ec_has_volatile; /* the (sole) member is a volatile expr */
941  bool ec_below_outer_join; /* equivalence applies below an OJ */
942  bool ec_broken; /* failed to generate needed clauses? */
943  Index ec_sortref; /* originating sortclause label, or 0 */
944  Index ec_min_security; /* minimum security_level in ec_sources */
945  Index ec_max_security; /* maximum security_level in ec_sources */
946  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
948 
949 /*
950  * If an EC contains a const and isn't below-outer-join, any PathKey depending
951  * on it must be redundant, since there's only one possible value of the key.
952  */
953 #define EC_MUST_BE_REDUNDANT(eclass) \
954  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
955 
956 /*
957  * EquivalenceMember - one member expression of an EquivalenceClass
958  *
959  * em_is_child signifies that this element was built by transposing a member
960  * for an appendrel parent relation to represent the corresponding expression
961  * for an appendrel child. These members are used for determining the
962  * pathkeys of scans on the child relation and for explicitly sorting the
963  * child when necessary to build a MergeAppend path for the whole appendrel
964  * tree. An em_is_child member has no impact on the properties of the EC as a
965  * whole; in particular the EC's ec_relids field does NOT include the child
966  * relation. An em_is_child member should never be marked em_is_const nor
967  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
968  * members are not really full-fledged members of the EC, but just reflections
969  * or doppelgangers of real members. Most operations on EquivalenceClasses
970  * should ignore em_is_child members, and those that don't should test
971  * em_relids to make sure they only consider relevant members.
972  *
973  * em_datatype is usually the same as exprType(em_expr), but can be
974  * different when dealing with a binary-compatible opfamily; in particular
975  * anyarray_ops would never work without this. Use em_datatype when
976  * looking up a specific btree operator to work with this expression.
977  */
978 typedef struct EquivalenceMember
979 {
981 
982  Expr *em_expr; /* the expression represented */
983  Relids em_relids; /* all relids appearing in em_expr */
984  Relids em_nullable_relids; /* nullable by lower outer joins */
985  bool em_is_const; /* expression is pseudoconstant? */
986  bool em_is_child; /* derived version for a child relation? */
987  Oid em_datatype; /* the "nominal type" used by the opfamily */
989 
990 /*
991  * PathKeys
992  *
993  * The sort ordering of a path is represented by a list of PathKey nodes.
994  * An empty list implies no known ordering. Otherwise the first item
995  * represents the primary sort key, the second the first secondary sort key,
996  * etc. The value being sorted is represented by linking to an
997  * EquivalenceClass containing that value and including pk_opfamily among its
998  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
999  * This is a convenient method because it makes it trivial to detect
1000  * equivalent and closely-related orderings. (See optimizer/README for more
1001  * information.)
1002  *
1003  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
1004  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
1005  * index types will use btree-compatible strategy numbers.
1006  */
1007 typedef struct PathKey
1008 {
1010 
1011  EquivalenceClass *pk_eclass; /* the value that is ordered */
1012  Oid pk_opfamily; /* btree opfamily defining the ordering */
1013  int pk_strategy; /* sort direction (ASC or DESC) */
1014  bool pk_nulls_first; /* do NULLs come before normal values? */
1015 } PathKey;
1016 
1017 
1018 /*
1019  * PathTarget
1020  *
1021  * This struct contains what we need to know during planning about the
1022  * targetlist (output columns) that a Path will compute. Each RelOptInfo
1023  * includes a default PathTarget, which its individual Paths may simply
1024  * reference. However, in some cases a Path may compute outputs different
1025  * from other Paths, and in that case we make a custom PathTarget for it.
1026  * For example, an indexscan might return index expressions that would
1027  * otherwise need to be explicitly calculated. (Note also that "upper"
1028  * relations generally don't have useful default PathTargets.)
1029  *
1030  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
1031  * though those will appear in finished Plans.
1032  *
1033  * sortgrouprefs[] is an array of the same length as exprs, containing the
1034  * corresponding sort/group refnos, or zeroes for expressions not referenced
1035  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
1036  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
1037  * we have not identified sort/group columns in this tlist. This allows us to
1038  * deal with sort/group refnos when needed with less expense than including
1039  * TargetEntry nodes in the exprs list.
1040  */
1041 typedef struct PathTarget
1042 {
1044  List *exprs; /* list of expressions to be computed */
1045  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
1046  QualCost cost; /* cost of evaluating the expressions */
1047  int width; /* estimated avg width of result tuples */
1048 } PathTarget;
1049 
1050 /* Convenience macro to get a sort/group refno from a PathTarget */
1051 #define get_pathtarget_sortgroupref(target, colno) \
1052  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
1053 
1054 
1055 /*
1056  * ParamPathInfo
1057  *
1058  * All parameterized paths for a given relation with given required outer rels
1059  * link to a single ParamPathInfo, which stores common information such as
1060  * the estimated rowcount for this parameterization. We do this partly to
1061  * avoid recalculations, but mostly to ensure that the estimated rowcount
1062  * is in fact the same for every such path.
1063  *
1064  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
1065  * in join cases it's NIL because the set of relevant clauses varies depending
1066  * on how the join is formed. The relevant clauses will appear in each
1067  * parameterized join path's joinrestrictinfo list, instead.
1068  */
1069 typedef struct ParamPathInfo
1070 {
1072 
1073  Relids ppi_req_outer; /* rels supplying parameters used by path */
1074  double ppi_rows; /* estimated number of result tuples */
1075  List *ppi_clauses; /* join clauses available from outer rels */
1076 } ParamPathInfo;
1077 
1078 
1079 /*
1080  * Type "Path" is used as-is for sequential-scan paths, as well as some other
1081  * simple plan types that we don't need any extra information in the path for.
1082  * For other path types it is the first component of a larger struct.
1083  *
1084  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
1085  * It is partially redundant with the Path's NodeTag, but allows us to use
1086  * the same Path type for multiple Plan types when there is no need to
1087  * distinguish the Plan type during path processing.
1088  *
1089  * "parent" identifies the relation this Path scans, and "pathtarget"
1090  * describes the precise set of output columns the Path would compute.
1091  * In simple cases all Paths for a given rel share the same targetlist,
1092  * which we represent by having path->pathtarget equal to parent->reltarget.
1093  *
1094  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
1095  * relation(s) that provide parameter values to each scan of this path.
1096  * That means this path can only be joined to those rels by means of nestloop
1097  * joins with this path on the inside. Also note that a parameterized path
1098  * is responsible for testing all "movable" joinclauses involving this rel
1099  * and the specified outer rel(s).
1100  *
1101  * "rows" is the same as parent->rows in simple paths, but in parameterized
1102  * paths and UniquePaths it can be less than parent->rows, reflecting the
1103  * fact that we've filtered by extra join conditions or removed duplicates.
1104  *
1105  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
1106  * ordering of the path's output rows.
1107  */
1108 typedef struct Path
1109 {
1111 
1112  NodeTag pathtype; /* tag identifying scan/join method */
1113 
1114  RelOptInfo *parent; /* the relation this path can build */
1115  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
1116 
1117  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
1118 
1119  bool parallel_aware; /* engage parallel-aware logic? */
1120  bool parallel_safe; /* OK to use as part of parallel plan? */
1121  int parallel_workers; /* desired # of workers; 0 = not parallel */
1122 
1123  /* estimated size/costs for path (see costsize.c for more info) */
1124  double rows; /* estimated number of result tuples */
1125  Cost startup_cost; /* cost expended before fetching any tuples */
1126  Cost total_cost; /* total cost (assuming all tuples fetched) */
1127 
1128  List *pathkeys; /* sort ordering of path's output */
1129  /* pathkeys is a List of PathKey nodes; see above */
1130 } Path;
1131 
1132 /* Macro for extracting a path's parameterization relids; beware double eval */
1133 #define PATH_REQ_OUTER(path) \
1134  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
1135 
1136 /*----------
1137  * IndexPath represents an index scan over a single index.
1138  *
1139  * This struct is used for both regular indexscans and index-only scans;
1140  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
1141  *
1142  * 'indexinfo' is the index to be scanned.
1143  *
1144  * 'indexclauses' is a list of IndexClause nodes, each representing one
1145  * index-checkable restriction, with implicit AND semantics across the list.
1146  * An empty list implies a full index scan.
1147  *
1148  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
1149  * been found to be usable as ordering operators for an amcanorderbyop index.
1150  * The list must match the path's pathkeys, ie, one expression per pathkey
1151  * in the same order. These are not RestrictInfos, just bare expressions,
1152  * since they generally won't yield booleans. It's guaranteed that each
1153  * expression has the index key on the left side of the operator.
1154  *
1155  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
1156  * of the same length as 'indexorderbys', showing which index column each
1157  * ORDER BY expression is meant to be used with. (There is no restriction
1158  * on which index column each ORDER BY can be used with.)
1159  *
1160  * 'indexscandir' is one of:
1161  * ForwardScanDirection: forward scan of an ordered index
1162  * BackwardScanDirection: backward scan of an ordered index
1163  * NoMovementScanDirection: scan of an unordered index, or don't care
1164  * (The executor doesn't care whether it gets ForwardScanDirection or
1165  * NoMovementScanDirection for an indexscan, but the planner wants to
1166  * distinguish ordered from unordered indexes for building pathkeys.)
1167  *
1168  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
1169  * we need not recompute them when considering using the same index in a
1170  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
1171  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
1172  *----------
1173  */
1174 typedef struct IndexPath
1175 {
1184 } IndexPath;
1185 
1186 /*
1187  * Each IndexClause references a RestrictInfo node from the query's WHERE
1188  * or JOIN conditions, and shows how that restriction can be applied to
1189  * the particular index. We support both indexclauses that are directly
1190  * usable by the index machinery, which are typically of the form
1191  * "indexcol OP pseudoconstant", and those from which an indexable qual
1192  * can be derived. The simplest such transformation is that a clause
1193  * of the form "pseudoconstant OP indexcol" can be commuted to produce an
1194  * indexable qual (the index machinery expects the indexcol to be on the
1195  * left always). Another example is that we might be able to extract an
1196  * indexable range condition from a LIKE condition, as in "x LIKE 'foo%bar'"
1197  * giving rise to "x >= 'foo' AND x < 'fop'". Derivation of such lossy
1198  * conditions is done by a planner support function attached to the
1199  * indexclause's top-level function or operator.
1200  *
1201  * indexquals is a list of RestrictInfos for the directly-usable index
1202  * conditions associated with this IndexClause. In the simplest case
1203  * it's a one-element list whose member is iclause->rinfo. Otherwise,
1204  * it contains one or more directly-usable indexqual conditions extracted
1205  * from the given clause. The 'lossy' flag indicates whether the
1206  * indexquals are semantically equivalent to the original clause, or
1207  * represent a weaker condition.
1208  *
1209  * Normally, indexcol is the index of the single index column the clause
1210  * works on, and indexcols is NIL. But if the clause is a RowCompareExpr,
1211  * indexcol is the index of the leading column, and indexcols is a list of
1212  * all the affected columns. (Note that indexcols matches up with the
1213  * columns of the actual indexable RowCompareExpr in indexquals, which
1214  * might be different from the original in rinfo.)
1215  *
1216  * An IndexPath's IndexClause list is required to be ordered by index
1217  * column, i.e. the indexcol values must form a nondecreasing sequence.
1218  * (The order of multiple clauses for the same index column is unspecified.)
1219  */
1220 typedef struct IndexClause
1221 {
1223  struct RestrictInfo *rinfo; /* original restriction or join clause */
1224  List *indexquals; /* indexqual(s) derived from it */
1225  bool lossy; /* are indexquals a lossy version of clause? */
1226  AttrNumber indexcol; /* index column the clause uses (zero-based) */
1227  List *indexcols; /* multiple index columns, if RowCompare */
1228 } IndexClause;
1229 
1230 /*
1231  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
1232  * instead of directly accessing the heap, followed by AND/OR combinations
1233  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
1234  * Note that the output is always considered unordered, since it will come
1235  * out in physical heap order no matter what the underlying indexes did.
1236  *
1237  * The individual indexscans are represented by IndexPath nodes, and any
1238  * logic on top of them is represented by a tree of BitmapAndPath and
1239  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
1240  * to represent a regular (or index-only) index scan plan, and as the child
1241  * of a BitmapHeapPath that represents scanning the same index using a
1242  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
1243  * always represent the costs to use it as a regular (or index-only)
1244  * IndexScan. The costs of a BitmapIndexScan can be computed using the
1245  * IndexPath's indextotalcost and indexselectivity.
1246  */
1247 typedef struct BitmapHeapPath
1248 {
1250  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1251 } BitmapHeapPath;
1252 
1253 /*
1254  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1255  * part of the substructure of a BitmapHeapPath. The Path structure is
1256  * a bit more heavyweight than we really need for this, but for simplicity
1257  * we make it a derivative of Path anyway.
1258  */
1259 typedef struct BitmapAndPath
1260 {
1262  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1264 } BitmapAndPath;
1265 
1266 /*
1267  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1268  * part of the substructure of a BitmapHeapPath. The Path structure is
1269  * a bit more heavyweight than we really need for this, but for simplicity
1270  * we make it a derivative of Path anyway.
1271  */
1272 typedef struct BitmapOrPath
1273 {
1275  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1277 } BitmapOrPath;
1278 
1279 /*
1280  * TidPath represents a scan by TID
1281  *
1282  * tidquals is an implicitly OR'ed list of qual expressions of the form
1283  * "CTID = pseudoconstant", or "CTID = ANY(pseudoconstant_array)",
1284  * or a CurrentOfExpr for the relation.
1285  */
1286 typedef struct TidPath
1287 {
1289  List *tidquals; /* qual(s) involving CTID = something */
1290 } TidPath;
1291 
1292 /*
1293  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1294  *
1295  * Note that the subpath comes from a different planning domain; for example
1296  * RTE indexes within it mean something different from those known to the
1297  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1298  * interpret the subpath.
1299  */
1300 typedef struct SubqueryScanPath
1301 {
1303  Path *subpath; /* path representing subquery execution */
1305 
1306 /*
1307  * ForeignPath represents a potential scan of a foreign table, foreign join
1308  * or foreign upper-relation.
1309  *
1310  * fdw_private stores FDW private data about the scan. While fdw_private is
1311  * not actually touched by the core code during normal operations, it's
1312  * generally a good idea to use a representation that can be dumped by
1313  * nodeToString(), so that you can examine the structure during debugging
1314  * with tools like pprint().
1315  */
1316 typedef struct ForeignPath
1317 {
1321 } ForeignPath;
1322 
1323 /*
1324  * CustomPath represents a table scan done by some out-of-core extension.
1325  *
1326  * We provide a set of hooks here - which the provider must take care to set
1327  * up correctly - to allow extensions to supply their own methods of scanning
1328  * a relation. For example, a provider might provide GPU acceleration, a
1329  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1330  *
1331  * CustomPaths can be injected into the planning process for a relation by
1332  * set_rel_pathlist_hook functions.
1333  *
1334  * Core code must avoid assuming that the CustomPath is only as large as
1335  * the structure declared here; providers are allowed to make it the first
1336  * element in a larger structure. (Since the planner never copies Paths,
1337  * this doesn't add any complication.) However, for consistency with the
1338  * FDW case, we provide a "custom_private" field in CustomPath; providers
1339  * may prefer to use that rather than define another struct type.
1340  */
1341 
1342 struct CustomPathMethods;
1343 
1344 typedef struct CustomPath
1345 {
1347  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1348  * nodes/extensible.h */
1349  List *custom_paths; /* list of child Path nodes, if any */
1352 } CustomPath;
1353 
1354 /*
1355  * AppendPath represents an Append plan, ie, successive execution of
1356  * several member plans.
1357  *
1358  * For partial Append, 'subpaths' contains non-partial subpaths followed by
1359  * partial subpaths.
1360  *
1361  * Note: it is possible for "subpaths" to contain only one, or even no,
1362  * elements. These cases are optimized during create_append_plan.
1363  * In particular, an AppendPath with no subpaths is a "dummy" path that
1364  * is created to represent the case that a relation is provably empty.
1365  * (This is a convenient representation because it means that when we build
1366  * an appendrel and find that all its children have been excluded, no extra
1367  * action is needed to recognize the relation as dummy.)
1368  */
1369 typedef struct AppendPath
1370 {
1372  /* RT indexes of non-leaf tables in a partition tree */
1374  List *subpaths; /* list of component Paths */
1375  /* Index of first partial path in subpaths; list_length(subpaths) if none */
1377  double limit_tuples; /* hard limit on output tuples, or -1 */
1378 } AppendPath;
1379 
1380 #define IS_DUMMY_APPEND(p) \
1381  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1382 
1383 /*
1384  * A relation that's been proven empty will have one path that is dummy
1385  * (but might have projection paths on top). For historical reasons,
1386  * this is provided as a macro that wraps is_dummy_rel().
1387  */
1388 #define IS_DUMMY_REL(r) is_dummy_rel(r)
1389 extern bool is_dummy_rel(RelOptInfo *rel);
1390 
1391 /*
1392  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1393  * results from several member plans to produce similarly-sorted output.
1394  */
1395 typedef struct MergeAppendPath
1396 {
1398  /* RT indexes of non-leaf tables in a partition tree */
1400  List *subpaths; /* list of component Paths */
1401  double limit_tuples; /* hard limit on output tuples, or -1 */
1402 } MergeAppendPath;
1403 
1404 /*
1405  * GroupResultPath represents use of a Result plan node to compute the
1406  * output of a degenerate GROUP BY case, wherein we know we should produce
1407  * exactly one row, which might then be filtered by a HAVING qual.
1408  *
1409  * Note that quals is a list of bare clauses, not RestrictInfos.
1410  */
1411 typedef struct GroupResultPath
1412 {
1415 } GroupResultPath;
1416 
1417 /*
1418  * MaterialPath represents use of a Material plan node, i.e., caching of
1419  * the output of its subpath. This is used when the subpath is expensive
1420  * and needs to be scanned repeatedly, or when we need mark/restore ability
1421  * and the subpath doesn't have it.
1422  */
1423 typedef struct MaterialPath
1424 {
1427 } MaterialPath;
1428 
1429 /*
1430  * UniquePath represents elimination of distinct rows from the output of
1431  * its subpath.
1432  *
1433  * This can represent significantly different plans: either hash-based or
1434  * sort-based implementation, or a no-op if the input path can be proven
1435  * distinct already. The decision is sufficiently localized that it's not
1436  * worth having separate Path node types. (Note: in the no-op case, we could
1437  * eliminate the UniquePath node entirely and just return the subpath; but
1438  * it's convenient to have a UniquePath in the path tree to signal upper-level
1439  * routines that the input is known distinct.)
1440  */
1441 typedef enum
1442 {
1443  UNIQUE_PATH_NOOP, /* input is known unique already */
1444  UNIQUE_PATH_HASH, /* use hashing */
1445  UNIQUE_PATH_SORT /* use sorting */
1447 
1448 typedef struct UniquePath
1449 {
1453  List *in_operators; /* equality operators of the IN clause */
1454  List *uniq_exprs; /* expressions to be made unique */
1455 } UniquePath;
1456 
1457 /*
1458  * GatherPath runs several copies of a plan in parallel and collects the
1459  * results. The parallel leader may also execute the plan, unless the
1460  * single_copy flag is set.
1461  */
1462 typedef struct GatherPath
1463 {
1465  Path *subpath; /* path for each worker */
1466  bool single_copy; /* don't execute path more than once */
1467  int num_workers; /* number of workers sought to help */
1468 } GatherPath;
1469 
1470 /*
1471  * GatherMergePath runs several copies of a plan in parallel and collects
1472  * the results, preserving their common sort order.
1473  */
1474 typedef struct GatherMergePath
1475 {
1477  Path *subpath; /* path for each worker */
1478  int num_workers; /* number of workers sought to help */
1479 } GatherMergePath;
1480 
1481 
1482 /*
1483  * All join-type paths share these fields.
1484  */
1485 
1486 typedef struct JoinPath
1487 {
1489 
1491 
1492  bool inner_unique; /* each outer tuple provably matches no more
1493  * than one inner tuple */
1494 
1495  Path *outerjoinpath; /* path for the outer side of the join */
1496  Path *innerjoinpath; /* path for the inner side of the join */
1497 
1498  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1499 
1500  /*
1501  * See the notes for RelOptInfo and ParamPathInfo to understand why
1502  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1503  * parent RelOptInfo.
1504  */
1505 } JoinPath;
1506 
1507 /*
1508  * A nested-loop path needs no special fields.
1509  */
1510 
1512 
1513 /*
1514  * A mergejoin path has these fields.
1515  *
1516  * Unlike other path types, a MergePath node doesn't represent just a single
1517  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1518  * node itself, there can be a Sort node for the outer input, a Sort node
1519  * for the inner input, and/or a Material node for the inner input. We could
1520  * represent these nodes by separate path nodes, but considering how many
1521  * different merge paths are investigated during a complex join problem,
1522  * it seems better to avoid unnecessary palloc overhead.
1523  *
1524  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1525  * that will be used in the merge.
1526  *
1527  * Note that the mergeclauses are a subset of the parent relation's
1528  * restriction-clause list. Any join clauses that are not mergejoinable
1529  * appear only in the parent's restrict list, and must be checked by a
1530  * qpqual at execution time.
1531  *
1532  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1533  * (resp. inner path) is already ordered appropriately for the
1534  * mergejoin. If it is not NIL then it is a PathKeys list describing
1535  * the ordering that must be created by an explicit Sort node.
1536  *
1537  * skip_mark_restore is true if the executor need not do mark/restore calls.
1538  * Mark/restore overhead is usually required, but can be skipped if we know
1539  * that the executor need find only one match per outer tuple, and that the
1540  * mergeclauses are sufficient to identify a match. In such cases the
1541  * executor can immediately advance the outer relation after processing a
1542  * match, and therefore it need never back up the inner relation.
1543  *
1544  * materialize_inner is true if a Material node should be placed atop the
1545  * inner input. This may appear with or without an inner Sort step.
1546  */
1547 
1548 typedef struct MergePath
1549 {
1551  List *path_mergeclauses; /* join clauses to be used for merge */
1552  List *outersortkeys; /* keys for explicit sort, if any */
1553  List *innersortkeys; /* keys for explicit sort, if any */
1554  bool skip_mark_restore; /* can executor skip mark/restore? */
1555  bool materialize_inner; /* add Materialize to inner? */
1556 } MergePath;
1557 
1558 /*
1559  * A hashjoin path has these fields.
1560  *
1561  * The remarks above for mergeclauses apply for hashclauses as well.
1562  *
1563  * Hashjoin does not care what order its inputs appear in, so we have
1564  * no need for sortkeys.
1565  */
1566 
1567 typedef struct HashPath
1568 {
1570  List *path_hashclauses; /* join clauses used for hashing */
1571  int num_batches; /* number of batches expected */
1572  double inner_rows_total; /* total inner rows expected */
1573 } HashPath;
1574 
1575 /*
1576  * ProjectionPath represents a projection (that is, targetlist computation)
1577  *
1578  * Nominally, this path node represents using a Result plan node to do a
1579  * projection step. However, if the input plan node supports projection,
1580  * we can just modify its output targetlist to do the required calculations
1581  * directly, and not need a Result. In some places in the planner we can just
1582  * jam the desired PathTarget into the input path node (and adjust its cost
1583  * accordingly), so we don't need a ProjectionPath. But in other places
1584  * it's necessary to not modify the input path node, so we need a separate
1585  * ProjectionPath node, which is marked dummy to indicate that we intend to
1586  * assign the work to the input plan node. The estimated cost for the
1587  * ProjectionPath node will account for whether a Result will be used or not.
1588  */
1589 typedef struct ProjectionPath
1590 {
1592  Path *subpath; /* path representing input source */
1593  bool dummypp; /* true if no separate Result is needed */
1594 } ProjectionPath;
1595 
1596 /*
1597  * ProjectSetPath represents evaluation of a targetlist that includes
1598  * set-returning function(s), which will need to be implemented by a
1599  * ProjectSet plan node.
1600  */
1601 typedef struct ProjectSetPath
1602 {
1604  Path *subpath; /* path representing input source */
1605 } ProjectSetPath;
1606 
1607 /*
1608  * SortPath represents an explicit sort step
1609  *
1610  * The sort keys are, by definition, the same as path.pathkeys.
1611  *
1612  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1613  * same as the input's pathtarget.
1614  */
1615 typedef struct SortPath
1616 {
1618  Path *subpath; /* path representing input source */
1619 } SortPath;
1620 
1621 /*
1622  * GroupPath represents grouping (of presorted input)
1623  *
1624  * groupClause represents the columns to be grouped on; the input path
1625  * must be at least that well sorted.
1626  *
1627  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1628  */
1629 typedef struct GroupPath
1630 {
1632  Path *subpath; /* path representing input source */
1633  List *groupClause; /* a list of SortGroupClause's */
1634  List *qual; /* quals (HAVING quals), if any */
1635 } GroupPath;
1636 
1637 /*
1638  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1639  *
1640  * The columns to be compared are the first numkeys columns of the path's
1641  * pathkeys. The input is presumed already sorted that way.
1642  */
1643 typedef struct UpperUniquePath
1644 {
1646  Path *subpath; /* path representing input source */
1647  int numkeys; /* number of pathkey columns to compare */
1648 } UpperUniquePath;
1649 
1650 /*
1651  * AggPath represents generic computation of aggregate functions
1652  *
1653  * This may involve plain grouping (but not grouping sets), using either
1654  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1655  * appropriately presorted.
1656  */
1657 typedef struct AggPath
1658 {
1660  Path *subpath; /* path representing input source */
1661  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1662  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1663  double numGroups; /* estimated number of groups in input */
1664  List *groupClause; /* a list of SortGroupClause's */
1665  List *qual; /* quals (HAVING quals), if any */
1666 } AggPath;
1667 
1668 /*
1669  * Various annotations used for grouping sets in the planner.
1670  */
1671 
1672 typedef struct GroupingSetData
1673 {
1675  List *set; /* grouping set as list of sortgrouprefs */
1676  double numGroups; /* est. number of result groups */
1677 } GroupingSetData;
1678 
1679 typedef struct RollupData
1680 {
1682  List *groupClause; /* applicable subset of parse->groupClause */
1683  List *gsets; /* lists of integer indexes into groupClause */
1684  List *gsets_data; /* list of GroupingSetData */
1685  double numGroups; /* est. number of result groups */
1686  bool hashable; /* can be hashed */
1687  bool is_hashed; /* to be implemented as a hashagg */
1688 } RollupData;
1689 
1690 /*
1691  * GroupingSetsPath represents a GROUPING SETS aggregation
1692  */
1693 
1694 typedef struct GroupingSetsPath
1695 {
1697  Path *subpath; /* path representing input source */
1698  AggStrategy aggstrategy; /* basic strategy */
1699  List *rollups; /* list of RollupData */
1700  List *qual; /* quals (HAVING quals), if any */
1702 
1703 /*
1704  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1705  */
1706 typedef struct MinMaxAggPath
1707 {
1709  List *mmaggregates; /* list of MinMaxAggInfo */
1710  List *quals; /* HAVING quals, if any */
1711 } MinMaxAggPath;
1712 
1713 /*
1714  * WindowAggPath represents generic computation of window functions
1715  */
1716 typedef struct WindowAggPath
1717 {
1719  Path *subpath; /* path representing input source */
1720  WindowClause *winclause; /* WindowClause we'll be using */
1721 } WindowAggPath;
1722 
1723 /*
1724  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1725  */
1726 typedef struct SetOpPath
1727 {
1729  Path *subpath; /* path representing input source */
1730  SetOpCmd cmd; /* what to do, see nodes.h */
1731  SetOpStrategy strategy; /* how to do it, see nodes.h */
1732  List *distinctList; /* SortGroupClauses identifying target cols */
1733  AttrNumber flagColIdx; /* where is the flag column, if any */
1734  int firstFlag; /* flag value for first input relation */
1735  double numGroups; /* estimated number of groups in input */
1736 } SetOpPath;
1737 
1738 /*
1739  * RecursiveUnionPath represents a recursive UNION node
1740  */
1741 typedef struct RecursiveUnionPath
1742 {
1744  Path *leftpath; /* paths representing input sources */
1746  List *distinctList; /* SortGroupClauses identifying target cols */
1747  int wtParam; /* ID of Param representing work table */
1748  double numGroups; /* estimated number of groups in input */
1750 
1751 /*
1752  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1753  */
1754 typedef struct LockRowsPath
1755 {
1757  Path *subpath; /* path representing input source */
1758  List *rowMarks; /* a list of PlanRowMark's */
1759  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1760 } LockRowsPath;
1761 
1762 /*
1763  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1764  *
1765  * We represent most things that will be in the ModifyTable plan node
1766  * literally, except we have child Path(s) not Plan(s). But analysis of the
1767  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1768  */
1769 typedef struct ModifyTablePath
1770 {
1772  CmdType operation; /* INSERT, UPDATE, or DELETE */
1773  bool canSetTag; /* do we set the command tag/es_processed? */
1774  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1775  Index rootRelation; /* Root RT index, if target is partitioned */
1776  bool partColsUpdated; /* some part key in hierarchy updated */
1777  List *resultRelations; /* integer list of RT indexes */
1778  List *subpaths; /* Path(s) producing source data */
1779  List *subroots; /* per-target-table PlannerInfos */
1780  List *withCheckOptionLists; /* per-target-table WCO lists */
1781  List *returningLists; /* per-target-table RETURNING tlists */
1782  List *rowMarks; /* PlanRowMarks (non-locking only) */
1783  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1784  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1785 } ModifyTablePath;
1786 
1787 /*
1788  * LimitPath represents applying LIMIT/OFFSET restrictions
1789  */
1790 typedef struct LimitPath
1791 {
1793  Path *subpath; /* path representing input source */
1794  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1795  Node *limitCount; /* COUNT parameter, or NULL if none */
1796 } LimitPath;
1797 
1798 
1799 /*
1800  * Restriction clause info.
1801  *
1802  * We create one of these for each AND sub-clause of a restriction condition
1803  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1804  * ANDed, we can use any one of them or any subset of them to filter out
1805  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1806  * stores data used by the optimizer while choosing the best query plan.
1807  *
1808  * If a restriction clause references a single base relation, it will appear
1809  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1810  *
1811  * If a restriction clause references more than one base rel, it will
1812  * appear in the joininfo list of every RelOptInfo that describes a strict
1813  * subset of the base rels mentioned in the clause. The joininfo lists are
1814  * used to drive join tree building by selecting plausible join candidates.
1815  * The clause cannot actually be applied until we have built a join rel
1816  * containing all the base rels it references, however.
1817  *
1818  * When we construct a join rel that includes all the base rels referenced
1819  * in a multi-relation restriction clause, we place that clause into the
1820  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1821  * right sub-path includes all base rels referenced in the clause. The clause
1822  * will be applied at that join level, and will not propagate any further up
1823  * the join tree. (Note: the "predicate migration" code was once intended to
1824  * push restriction clauses up and down the plan tree based on evaluation
1825  * costs, but it's dead code and is unlikely to be resurrected in the
1826  * foreseeable future.)
1827  *
1828  * Note that in the presence of more than two rels, a multi-rel restriction
1829  * might reach different heights in the join tree depending on the join
1830  * sequence we use. So, these clauses cannot be associated directly with
1831  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1832  *
1833  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1834  * equalities that are not outerjoin-delayed) are handled a bit differently.
1835  * Initially we attach them to the EquivalenceClasses that are derived from
1836  * them. When we construct a scan or join path, we look through all the
1837  * EquivalenceClasses and generate derived RestrictInfos representing the
1838  * minimal set of conditions that need to be checked for this particular scan
1839  * or join to enforce that all members of each EquivalenceClass are in fact
1840  * equal in all rows emitted by the scan or join.
1841  *
1842  * When dealing with outer joins we have to be very careful about pushing qual
1843  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1844  * be evaluated exactly at that join node, unless they are "degenerate"
1845  * conditions that reference only Vars from the nullable side of the join.
1846  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1847  * down below the outer join, if they reference any nullable Vars.
1848  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1849  * pushed down to a lower level than its original syntactic placement in the
1850  * join tree would suggest. If an outer join prevents us from pushing a qual
1851  * down to its "natural" semantic level (the level associated with just the
1852  * base rels used in the qual) then we mark the qual with a "required_relids"
1853  * value including more than just the base rels it actually uses. By
1854  * pretending that the qual references all the rels required to form the outer
1855  * join, we prevent it from being evaluated below the outer join's joinrel.
1856  * When we do form the outer join's joinrel, we still need to distinguish
1857  * those quals that are actually in that join's JOIN/ON condition from those
1858  * that appeared elsewhere in the tree and were pushed down to the join rel
1859  * because they used no other rels. That's what the is_pushed_down flag is
1860  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1861  * rels listed in required_relids. A clause that originally came from WHERE
1862  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1863  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1864  * if we decide that it can be pushed down into the nullable side of the join.
1865  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1866  * (In short, is_pushed_down is only false for non-degenerate outer join
1867  * conditions. Possibly we should rename it to reflect that meaning? But
1868  * see also the comments for RINFO_IS_PUSHED_DOWN, below.)
1869  *
1870  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1871  * if the clause's applicability must be delayed due to any outer joins
1872  * appearing below it (ie, it has to be postponed to some join level higher
1873  * than the set of relations it actually references).
1874  *
1875  * There is also an outer_relids field, which is NULL except for outer join
1876  * clauses; for those, it is the set of relids on the outer side of the
1877  * clause's outer join. (These are rels that the clause cannot be applied to
1878  * in parameterized scans, since pushing it into the join's outer side would
1879  * lead to wrong answers.)
1880  *
1881  * There is also a nullable_relids field, which is the set of rels the clause
1882  * references that can be forced null by some outer join below the clause.
1883  *
1884  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1885  * a clause might reference some nullable rels and yet not be
1886  * outerjoin_delayed because it also references all the other rels of the
1887  * outer join(s). A clause that is not outerjoin_delayed can be enforced
1888  * anywhere it is computable.
1889  *
1890  * To handle security-barrier conditions efficiently, we mark RestrictInfo
1891  * nodes with a security_level field, in which higher values identify clauses
1892  * coming from less-trusted sources. The exact semantics are that a clause
1893  * cannot be evaluated before another clause with a lower security_level value
1894  * unless the first clause is leakproof. As with outer-join clauses, this
1895  * creates a reason for clauses to sometimes need to be evaluated higher in
1896  * the join tree than their contents would suggest; and even at a single plan
1897  * node, this rule constrains the order of application of clauses.
1898  *
1899  * In general, the referenced clause might be arbitrarily complex. The
1900  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
1901  * or hashjoin clauses are limited (e.g., no volatile functions). The code
1902  * for each kind of path is responsible for identifying the restrict clauses
1903  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
1904  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
1905  * of the finished Plan node, where they will be enforced by general-purpose
1906  * qual-expression-evaluation code. (But we are still entitled to count
1907  * their selectivity when estimating the result tuple count, if we
1908  * can guess what it is...)
1909  *
1910  * When the referenced clause is an OR clause, we generate a modified copy
1911  * in which additional RestrictInfo nodes are inserted below the top-level
1912  * OR/AND structure. This is a convenience for OR indexscan processing:
1913  * indexquals taken from either the top level or an OR subclause will have
1914  * associated RestrictInfo nodes.
1915  *
1916  * The can_join flag is set true if the clause looks potentially useful as
1917  * a merge or hash join clause, that is if it is a binary opclause with
1918  * nonoverlapping sets of relids referenced in the left and right sides.
1919  * (Whether the operator is actually merge or hash joinable isn't checked,
1920  * however.)
1921  *
1922  * The pseudoconstant flag is set true if the clause contains no Vars of
1923  * the current query level and no volatile functions. Such a clause can be
1924  * pulled out and used as a one-time qual in a gating Result node. We keep
1925  * pseudoconstant clauses in the same lists as other RestrictInfos so that
1926  * the regular clause-pushing machinery can assign them to the correct join
1927  * level, but they need to be treated specially for cost and selectivity
1928  * estimates. Note that a pseudoconstant clause can never be an indexqual
1929  * or merge or hash join clause, so it's of no interest to large parts of
1930  * the planner.
1931  *
1932  * When join clauses are generated from EquivalenceClasses, there may be
1933  * several equally valid ways to enforce join equivalence, of which we need
1934  * apply only one. We mark clauses of this kind by setting parent_ec to
1935  * point to the generating EquivalenceClass. Multiple clauses with the same
1936  * parent_ec in the same join are redundant.
1937  */
1938 
1939 typedef struct RestrictInfo
1940 {
1942 
1943  Expr *clause; /* the represented clause of WHERE or JOIN */
1944 
1945  bool is_pushed_down; /* true if clause was pushed down in level */
1946 
1947  bool outerjoin_delayed; /* true if delayed by lower outer join */
1948 
1949  bool can_join; /* see comment above */
1950 
1951  bool pseudoconstant; /* see comment above */
1952 
1953  bool leakproof; /* true if known to contain no leaked Vars */
1954 
1955  Index security_level; /* see comment above */
1956 
1957  /* The set of relids (varnos) actually referenced in the clause: */
1959 
1960  /* The set of relids required to evaluate the clause: */
1962 
1963  /* If an outer-join clause, the outer-side relations, else NULL: */
1965 
1966  /* The relids used in the clause that are nullable by lower outer joins: */
1968 
1969  /* These fields are set for any binary opclause: */
1970  Relids left_relids; /* relids in left side of clause */
1971  Relids right_relids; /* relids in right side of clause */
1972 
1973  /* This field is NULL unless clause is an OR clause: */
1974  Expr *orclause; /* modified clause with RestrictInfos */
1975 
1976  /* This field is NULL unless clause is potentially redundant: */
1977  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
1978 
1979  /* cache space for cost and selectivity */
1980  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
1981  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
1982  * semantics; -1 if not yet set; >1 means a
1983  * redundant clause */
1984  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
1985  * not yet set */
1986 
1987  /* valid if clause is mergejoinable, else NIL */
1988  List *mergeopfamilies; /* opfamilies containing clause operator */
1989 
1990  /* cache space for mergeclause processing; NULL if not yet set */
1991  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
1992  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
1993  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
1994  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
1995  List *scansel_cache; /* list of MergeScanSelCache structs */
1996 
1997  /* transient workspace for use while considering a specific join path */
1998  bool outer_is_left; /* T = outer var on left, F = on right */
1999 
2000  /* valid if clause is hashjoinable, else InvalidOid: */
2001  Oid hashjoinoperator; /* copy of clause operator */
2002 
2003  /* cache space for hashclause processing; -1 if not yet set */
2004  Selectivity left_bucketsize; /* avg bucketsize of left side */
2005  Selectivity right_bucketsize; /* avg bucketsize of right side */
2006  Selectivity left_mcvfreq; /* left side's most common val's freq */
2007  Selectivity right_mcvfreq; /* right side's most common val's freq */
2008 } RestrictInfo;
2009 
2010 /*
2011  * This macro embodies the correct way to test whether a RestrictInfo is
2012  * "pushed down" to a given outer join, that is, should be treated as a filter
2013  * clause rather than a join clause at that outer join. This is certainly so
2014  * if is_pushed_down is true; but examining that is not sufficient anymore,
2015  * because outer-join clauses will get pushed down to lower outer joins when
2016  * we generate a path for the lower outer join that is parameterized by the
2017  * LHS of the upper one. We can detect such a clause by noting that its
2018  * required_relids exceed the scope of the join.
2019  */
2020 #define RINFO_IS_PUSHED_DOWN(rinfo, joinrelids) \
2021  ((rinfo)->is_pushed_down || \
2022  !bms_is_subset((rinfo)->required_relids, joinrelids))
2023 
2024 /*
2025  * Since mergejoinscansel() is a relatively expensive function, and would
2026  * otherwise be invoked many times while planning a large join tree,
2027  * we go out of our way to cache its results. Each mergejoinable
2028  * RestrictInfo carries a list of the specific sort orderings that have
2029  * been considered for use with it, and the resulting selectivities.
2030  */
2031 typedef struct MergeScanSelCache
2032 {
2033  /* Ordering details (cache lookup key) */
2034  Oid opfamily; /* btree opfamily defining the ordering */
2035  Oid collation; /* collation for the ordering */
2036  int strategy; /* sort direction (ASC or DESC) */
2037  bool nulls_first; /* do NULLs come before normal values? */
2038  /* Results */
2039  Selectivity leftstartsel; /* first-join fraction for clause left side */
2040  Selectivity leftendsel; /* last-join fraction for clause left side */
2041  Selectivity rightstartsel; /* first-join fraction for clause right side */
2042  Selectivity rightendsel; /* last-join fraction for clause right side */
2044 
2045 /*
2046  * Placeholder node for an expression to be evaluated below the top level
2047  * of a plan tree. This is used during planning to represent the contained
2048  * expression. At the end of the planning process it is replaced by either
2049  * the contained expression or a Var referring to a lower-level evaluation of
2050  * the contained expression. Typically the evaluation occurs below an outer
2051  * join, and Var references above the outer join might thereby yield NULL
2052  * instead of the expression value.
2053  *
2054  * Although the planner treats this as an expression node type, it is not
2055  * recognized by the parser or executor, so we declare it here rather than
2056  * in primnodes.h.
2057  */
2058 
2059 typedef struct PlaceHolderVar
2060 {
2062  Expr *phexpr; /* the represented expression */
2063  Relids phrels; /* base relids syntactically within expr src */
2064  Index phid; /* ID for PHV (unique within planner run) */
2065  Index phlevelsup; /* > 0 if PHV belongs to outer query */
2066 } PlaceHolderVar;
2067 
2068 /*
2069  * "Special join" info.
2070  *
2071  * One-sided outer joins constrain the order of joining partially but not
2072  * completely. We flatten such joins into the planner's top-level list of
2073  * relations to join, but record information about each outer join in a
2074  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
2075  * join_info_list.
2076  *
2077  * Similarly, semijoins and antijoins created by flattening IN (subselect)
2078  * and EXISTS(subselect) clauses create partial constraints on join order.
2079  * These are likewise recorded in SpecialJoinInfo structs.
2080  *
2081  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
2082  * of planning for them, because this simplifies make_join_rel()'s API.
2083  *
2084  * min_lefthand and min_righthand are the sets of base relids that must be
2085  * available on each side when performing the special join. lhs_strict is
2086  * true if the special join's condition cannot succeed when the LHS variables
2087  * are all NULL (this means that an outer join can commute with upper-level
2088  * outer joins even if it appears in their RHS). We don't bother to set
2089  * lhs_strict for FULL JOINs, however.
2090  *
2091  * It is not valid for either min_lefthand or min_righthand to be empty sets;
2092  * if they were, this would break the logic that enforces join order.
2093  *
2094  * syn_lefthand and syn_righthand are the sets of base relids that are
2095  * syntactically below this special join. (These are needed to help compute
2096  * min_lefthand and min_righthand for higher joins.)
2097  *
2098  * delay_upper_joins is set true if we detect a pushed-down clause that has
2099  * to be evaluated after this join is formed (because it references the RHS).
2100  * Any outer joins that have such a clause and this join in their RHS cannot
2101  * commute with this join, because that would leave noplace to check the
2102  * pushed-down clause. (We don't track this for FULL JOINs, either.)
2103  *
2104  * For a semijoin, we also extract the join operators and their RHS arguments
2105  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
2106  * This is done in support of possibly unique-ifying the RHS, so we don't
2107  * bother unless at least one of semi_can_btree and semi_can_hash can be set
2108  * true. (You might expect that this information would be computed during
2109  * join planning; but it's helpful to have it available during planning of
2110  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
2111  *
2112  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
2113  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
2114  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
2115  *
2116  * For purposes of join selectivity estimation, we create transient
2117  * SpecialJoinInfo structures for regular inner joins; so it is possible
2118  * to have jointype == JOIN_INNER in such a structure, even though this is
2119  * not allowed within join_info_list. We also create transient
2120  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
2121  * cost estimation purposes it is sometimes useful to know the join size under
2122  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
2123  * of course the semi_xxx fields are not set meaningfully within such structs.
2124  */
2125 #ifndef HAVE_SPECIALJOININFO_TYPEDEF
2127 #define HAVE_SPECIALJOININFO_TYPEDEF 1
2128 #endif
2129 
2131 {
2133  Relids min_lefthand; /* base relids in minimum LHS for join */
2134  Relids min_righthand; /* base relids in minimum RHS for join */
2135  Relids syn_lefthand; /* base relids syntactically within LHS */
2136  Relids syn_righthand; /* base relids syntactically within RHS */
2137  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
2138  bool lhs_strict; /* joinclause is strict for some LHS rel */
2139  bool delay_upper_joins; /* can't commute with upper RHS */
2140  /* Remaining fields are set only for JOIN_SEMI jointype: */
2141  bool semi_can_btree; /* true if semi_operators are all btree */
2142  bool semi_can_hash; /* true if semi_operators are all hash */
2143  List *semi_operators; /* OIDs of equality join operators */
2144  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
2145 };
2146 
2147 /*
2148  * Append-relation info.
2149  *
2150  * When we expand an inheritable table or a UNION-ALL subselect into an
2151  * "append relation" (essentially, a list of child RTEs), we build an
2152  * AppendRelInfo for each child RTE. The list of AppendRelInfos indicates
2153  * which child RTEs must be included when expanding the parent, and each node
2154  * carries information needed to translate Vars referencing the parent into
2155  * Vars referencing that child.
2156  *
2157  * These structs are kept in the PlannerInfo node's append_rel_list.
2158  * Note that we just throw all the structs into one list, and scan the
2159  * whole list when desiring to expand any one parent. We could have used
2160  * a more complex data structure (eg, one list per parent), but this would
2161  * be harder to update during operations such as pulling up subqueries,
2162  * and not really any easier to scan. Considering that typical queries
2163  * will not have many different append parents, it doesn't seem worthwhile
2164  * to complicate things.
2165  *
2166  * Note: after completion of the planner prep phase, any given RTE is an
2167  * append parent having entries in append_rel_list if and only if its
2168  * "inh" flag is set. We clear "inh" for plain tables that turn out not
2169  * to have inheritance children, and (in an abuse of the original meaning
2170  * of the flag) we set "inh" for subquery RTEs that turn out to be
2171  * flattenable UNION ALL queries. This lets us avoid useless searches
2172  * of append_rel_list.
2173  *
2174  * Note: the data structure assumes that append-rel members are single
2175  * baserels. This is OK for inheritance, but it prevents us from pulling
2176  * up a UNION ALL member subquery if it contains a join. While that could
2177  * be fixed with a more complex data structure, at present there's not much
2178  * point because no improvement in the plan could result.
2179  */
2180 
2181 typedef struct AppendRelInfo
2182 {
2184 
2185  /*
2186  * These fields uniquely identify this append relationship. There can be
2187  * (in fact, always should be) multiple AppendRelInfos for the same
2188  * parent_relid, but never more than one per child_relid, since a given
2189  * RTE cannot be a child of more than one append parent.
2190  */
2191  Index parent_relid; /* RT index of append parent rel */
2192  Index child_relid; /* RT index of append child rel */
2193 
2194  /*
2195  * For an inheritance appendrel, the parent and child are both regular
2196  * relations, and we store their rowtype OIDs here for use in translating
2197  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
2198  * both subqueries with no named rowtype, and we store InvalidOid here.
2199  */
2200  Oid parent_reltype; /* OID of parent's composite type */
2201  Oid child_reltype; /* OID of child's composite type */
2202 
2203  /*
2204  * The N'th element of this list is a Var or expression representing the
2205  * child column corresponding to the N'th column of the parent. This is
2206  * used to translate Vars referencing the parent rel into references to
2207  * the child. A list element is NULL if it corresponds to a dropped
2208  * column of the parent (this is only possible for inheritance cases, not
2209  * UNION ALL). The list elements are always simple Vars for inheritance
2210  * cases, but can be arbitrary expressions in UNION ALL cases.
2211  *
2212  * Notice we only store entries for user columns (attno > 0). Whole-row
2213  * Vars are special-cased, and system columns (attno < 0) need no special
2214  * translation since their attnos are the same for all tables.
2215  *
2216  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
2217  * when copying into a subquery.
2218  */
2219  List *translated_vars; /* Expressions in the child's Vars */
2220 
2221  /*
2222  * We store the parent table's OID here for inheritance, or InvalidOid for
2223  * UNION ALL. This is only needed to help in generating error messages if
2224  * an attempt is made to reference a dropped parent column.
2225  */
2226  Oid parent_reloid; /* OID of parent relation */
2227 } AppendRelInfo;
2228 
2229 /*
2230  * For each distinct placeholder expression generated during planning, we
2231  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
2232  * This stores info that is needed centrally rather than in each copy of the
2233  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
2234  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
2235  * not just within a query level --- this is so that we need not reassign ID's
2236  * when pulling a subquery into its parent.
2237  *
2238  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
2239  * then allow it to bubble up like a Var until the ph_needed join level.
2240  * ph_needed has the same definition as attr_needed for a regular Var.
2241  *
2242  * The PlaceHolderVar's expression might contain LATERAL references to vars
2243  * coming from outside its syntactic scope. If so, those rels are *not*
2244  * included in ph_eval_at, but they are recorded in ph_lateral.
2245  *
2246  * Notice that when ph_eval_at is a join rather than a single baserel, the
2247  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
2248  * has to be formed below any outer joins that should null the PlaceHolderVar.
2249  *
2250  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
2251  * is actually referenced in the plan tree, so that unreferenced placeholders
2252  * don't result in unnecessary constraints on join order.
2253  */
2254 
2255 typedef struct PlaceHolderInfo
2256 {
2258 
2259  Index phid; /* ID for PH (unique within planner run) */
2260  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
2261  Relids ph_eval_at; /* lowest level we can evaluate value at */
2262  Relids ph_lateral; /* relids of contained lateral refs, if any */
2263  Relids ph_needed; /* highest level the value is needed at */
2264  int32 ph_width; /* estimated attribute width */
2265 } PlaceHolderInfo;
2266 
2267 /*
2268  * This struct describes one potentially index-optimizable MIN/MAX aggregate
2269  * function. MinMaxAggPath contains a list of these, and if we accept that
2270  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
2271  */
2272 typedef struct MinMaxAggInfo
2273 {
2275 
2276  Oid aggfnoid; /* pg_proc Oid of the aggregate */
2277  Oid aggsortop; /* Oid of its sort operator */
2278  Expr *target; /* expression we are aggregating on */
2279  PlannerInfo *subroot; /* modified "root" for planning the subquery */
2280  Path *path; /* access path for subquery */
2281  Cost pathcost; /* estimated cost to fetch first row */
2282  Param *param; /* param for subplan's output */
2283 } MinMaxAggInfo;
2284 
2285 /*
2286  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
2287  * node to another. They can be used to pass values down into subqueries (for
2288  * outer references in subqueries), or up out of subqueries (for the results
2289  * of a subplan), or from a NestLoop plan node into its inner relation (when
2290  * the inner scan is parameterized with values from the outer relation).
2291  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
2292  * the PARAM_EXEC Params it generates.
2293  *
2294  * Outer references are managed via root->plan_params, which is a list of
2295  * PlannerParamItems. While planning a subquery, each parent query level's
2296  * plan_params contains the values required from it by the current subquery.
2297  * During create_plan(), we use plan_params to track values that must be
2298  * passed from outer to inner sides of NestLoop plan nodes.
2299  *
2300  * The item a PlannerParamItem represents can be one of three kinds:
2301  *
2302  * A Var: the slot represents a variable of this level that must be passed
2303  * down because subqueries have outer references to it, or must be passed
2304  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
2305  * will always be zero.
2306  *
2307  * A PlaceHolderVar: this works much like the Var case, except that the
2308  * entry is a PlaceHolderVar node with a contained expression. The PHV
2309  * will have phlevelsup = 0, and the contained expression is adjusted
2310  * to match in level.
2311  *
2312  * An Aggref (with an expression tree representing its argument): the slot
2313  * represents an aggregate expression that is an outer reference for some
2314  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
2315  * is adjusted to match in level.
2316  *
2317  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
2318  * them into one slot, but we do not bother to do that for Aggrefs.
2319  * The scope of duplicate-elimination only extends across the set of
2320  * parameters passed from one query level into a single subquery, or for
2321  * nestloop parameters across the set of nestloop parameters used in a single
2322  * query level. So there is no possibility of a PARAM_EXEC slot being used
2323  * for conflicting purposes.
2324  *
2325  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2326  * from subplans (values that are setParam items for those subplans). These
2327  * IDs need not be tracked via PlannerParamItems, since we do not need any
2328  * duplicate-elimination nor later processing of the represented expressions.
2329  * Instead, we just record the assignment of the slot number by appending to
2330  * root->glob->paramExecTypes.
2331  */
2332 typedef struct PlannerParamItem
2333 {
2335 
2336  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2337  int paramId; /* its assigned PARAM_EXEC slot number */
2339 
2340 /*
2341  * When making cost estimates for a SEMI/ANTI/inner_unique join, there are
2342  * some correction factors that are needed in both nestloop and hash joins
2343  * to account for the fact that the executor can stop scanning inner rows
2344  * as soon as it finds a match to the current outer row. These numbers
2345  * depend only on the selected outer and inner join relations, not on the
2346  * particular paths used for them, so it's worthwhile to calculate them
2347  * just once per relation pair not once per considered path. This struct
2348  * is filled by compute_semi_anti_join_factors and must be passed along
2349  * to the join cost estimation functions.
2350  *
2351  * outer_match_frac is the fraction of the outer tuples that are
2352  * expected to have at least one match.
2353  * match_count is the average number of matches expected for
2354  * outer tuples that have at least one match.
2355  */
2356 typedef struct SemiAntiJoinFactors
2357 {
2361 
2362 /*
2363  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2364  *
2365  * restrictlist contains all of the RestrictInfo nodes for restriction
2366  * clauses that apply to this join
2367  * mergeclause_list is a list of RestrictInfo nodes for available
2368  * mergejoin clauses in this join
2369  * inner_unique is true if each outer tuple provably matches no more
2370  * than one inner tuple
2371  * sjinfo is extra info about special joins for selectivity estimation
2372  * semifactors is as shown above (only valid for SEMI/ANTI/inner_unique joins)
2373  * param_source_rels are OK targets for parameterization of result paths
2374  */
2375 typedef struct JoinPathExtraData
2376 {
2384 
2385 /*
2386  * Various flags indicating what kinds of grouping are possible.
2387  *
2388  * GROUPING_CAN_USE_SORT should be set if it's possible to perform
2389  * sort-based implementations of grouping. When grouping sets are in use,
2390  * this will be true if sorting is potentially usable for any of the grouping
2391  * sets, even if it's not usable for all of them.
2392  *
2393  * GROUPING_CAN_USE_HASH should be set if it's possible to perform
2394  * hash-based implementations of grouping.
2395  *
2396  * GROUPING_CAN_PARTIAL_AGG should be set if the aggregation is of a type
2397  * for which we support partial aggregation (not, for example, grouping sets).
2398  * It says nothing about parallel-safety or the availability of suitable paths.
2399  */
2400 #define GROUPING_CAN_USE_SORT 0x0001
2401 #define GROUPING_CAN_USE_HASH 0x0002
2402 #define GROUPING_CAN_PARTIAL_AGG 0x0004
2403 
2404 /*
2405  * What kind of partitionwise aggregation is in use?
2406  *
2407  * PARTITIONWISE_AGGREGATE_NONE: Not used.
2408  *
2409  * PARTITIONWISE_AGGREGATE_FULL: Aggregate each partition separately, and
2410  * append the results.
2411  *
2412  * PARTITIONWISE_AGGREGATE_PARTIAL: Partially aggregate each partition
2413  * separately, append the results, and then finalize aggregation.
2414  */
2415 typedef enum
2416 {
2421 
2422 /*
2423  * Struct for extra information passed to subroutines of create_grouping_paths
2424  *
2425  * flags indicating what kinds of grouping are possible.
2426  * partial_costs_set is true if the agg_partial_costs and agg_final_costs
2427  * have been initialized.
2428  * agg_partial_costs gives partial aggregation costs.
2429  * agg_final_costs gives finalization costs.
2430  * target_parallel_safe is true if target is parallel safe.
2431  * havingQual gives list of quals to be applied after aggregation.
2432  * targetList gives list of columns to be projected.
2433  * patype is the type of partitionwise aggregation that is being performed.
2434  */
2435 typedef struct
2436 {
2437  /* Data which remains constant once set. */
2438  int flags;
2442 
2443  /* Data which may differ across partitions. */
2449 
2450 /*
2451  * Struct for extra information passed to subroutines of grouping_planner
2452  *
2453  * limit_needed is true if we actually need a Limit plan node.
2454  * limit_tuples is an estimated bound on the number of output tuples,
2455  * or -1 if no LIMIT or couldn't estimate.
2456  * count_est and offset_est are the estimated values of the LIMIT and OFFSET
2457  * expressions computed by preprocess_limit() (see comments for
2458  * preprocess_limit() for more information).
2459  */
2460 typedef struct
2461 {
2464  int64 count_est;
2465  int64 offset_est;
2467 
2468 /*
2469  * For speed reasons, cost estimation for join paths is performed in two
2470  * phases: the first phase tries to quickly derive a lower bound for the
2471  * join cost, and then we check if that's sufficient to reject the path.
2472  * If not, we come back for a more refined cost estimate. The first phase
2473  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2474  * and possibly additional intermediate values. The second phase takes
2475  * these values as inputs to avoid repeating work.
2476  *
2477  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2478  * so seems best to put it here.)
2479  */
2480 typedef struct JoinCostWorkspace
2481 {
2482  /* Preliminary cost estimates --- must not be larger than final ones! */
2483  Cost startup_cost; /* cost expended before fetching any tuples */
2484  Cost total_cost; /* total cost (assuming all tuples fetched) */
2485 
2486  /* Fields below here should be treated as private to costsize.c */
2487  Cost run_cost; /* non-startup cost components */
2488 
2489  /* private for cost_nestloop code */
2490  Cost inner_run_cost; /* also used by cost_mergejoin code */
2492 
2493  /* private for cost_mergejoin code */
2494  double outer_rows;
2495  double inner_rows;
2498 
2499  /* private for cost_hashjoin code */
2504 
2505 #endif /* PATHNODES_H */
QualCost eval_cost
Definition: pathnodes.h:1980
bool has_eclass_joins
Definition: pathnodes.h:709
struct TidPath TidPath
struct Path * cheapest_unique_path
Definition: pathnodes.h:660
NodeTag type
Definition: pathnodes.h:1681
List * indexorderbycols
Definition: pathnodes.h:1180
signed short int16
Definition: c.h:345
char maxParallelHazard
Definition: pathnodes.h:145
List * group_pathkeys
Definition: pathnodes.h:298
struct ProjectionPath ProjectionPath
struct UpperUniquePath UpperUniquePath
List * rowMarks
Definition: pathnodes.h:290
struct QualCost QualCost
Relids ph_needed
Definition: pathnodes.h:2263
List * qual
Definition: pathnodes.h:1634
Definition: fmgr.h:56
Selectivity leftendsel
Definition: pathnodes.h:2040
List * path_mergeclauses
Definition: pathnodes.h:1551
UpperRelationKind
Definition: pathnodes.h:71
int join_cur_level
Definition: pathnodes.h:255
List * outersortkeys
Definition: pathnodes.h:1552
List * distinctList
Definition: pathnodes.h:1732
List * unique_for_rels
Definition: pathnodes.h:698
struct HashPath HashPath
JoinPath jpath
Definition: pathnodes.h:1569
PathTarget * pathtarget
Definition: pathnodes.h:1115
Query * parse
Definition: pathnodes.h:177
List * statlist
Definition: pathnodes.h:679
List * returningLists
Definition: pathnodes.h:1781
struct EquivalenceMember EquivalenceMember
Index security_level
Definition: pathnodes.h:1955
OnConflictExpr * onconflict
Definition: pathnodes.h:1783
struct StatisticExtInfo StatisticExtInfo
List * groupClause
Definition: pathnodes.h:1682
Node * limitOffset
Definition: pathnodes.h:1794
Path path
Definition: pathnodes.h:1176
NodeTag type
Definition: pathnodes.h:2183
Path * subpath
Definition: pathnodes.h:1618
Relids ph_eval_at
Definition: pathnodes.h:2261
List * plan_params
Definition: pathnodes.h:191
PlaceHolderVar * ph_var
Definition: pathnodes.h:2260
IndexOptInfo * indexinfo
Definition: pathnodes.h:1177
SemiAntiJoinFactors semifactors
Definition: pathnodes.h:2381
Index nominalRelation
Definition: pathnodes.h:1774
Oid * indexcollations
Definition: pathnodes.h:803
bool hasJoinRTEs
Definition: pathnodes.h:343
Path * fdw_outerpath
Definition: pathnodes.h:1319
RelOptKind reloptkind
Definition: pathnodes.h:638
Relids * attr_needed
Definition: pathnodes.h:674
bool ec_merging_done
Definition: pathnodes.h:266
PartitionwiseAggregateType
Definition: pathnodes.h:2415
List * custom_paths
Definition: pathnodes.h:1349
List * query_pathkeys
Definition: pathnodes.h:296
int num_batches
Definition: pathnodes.h:1571
List * join_info_list
Definition: pathnodes.h:281
Relids required_relids
Definition: pathnodes.h:1961
SetOpStrategy strategy
Definition: pathnodes.h:1731
Relids min_righthand
Definition: pathnodes.h:2134
AggStrategy aggstrategy
Definition: pathnodes.h:1661
bool materialize_inner
Definition: pathnodes.h:1555
void * join_search_private
Definition: pathnodes.h:359
Selectivity right_mcvfreq
Definition: pathnodes.h:2007
Relids curOuterRels
Definition: pathnodes.h:355
List * qual
Definition: pathnodes.h:1665
PlannerInfo * parent_root
Definition: pathnodes.h:183
bool leakproof
Definition: pathnodes.h:1953
double limit_tuples
Definition: pathnodes.h:1377
Index ec_min_security
Definition: pathnodes.h:944
Expr * orclause
Definition: pathnodes.h:1974
Selectivity outer_match_frac
Definition: pathnodes.h:2358
Path * innerjoinpath
Definition: pathnodes.h:1496
List * indextlist
Definition: pathnodes.h:816
struct Path * cheapest_startup_path
Definition: pathnodes.h:658
Oid userid
Definition: pathnodes.h:691
QualCost finalCost
Definition: pathnodes.h:63
struct PartitionSchemeData PartitionSchemeData
Relids em_nullable_relids
Definition: pathnodes.h:984
int lastPlanNodeId
Definition: pathnodes.h:135
double tuples
Definition: pathnodes.h:681
Oid reltablespace
Definition: pathnodes.h:670
Path * subpath
Definition: pathnodes.h:1729
struct RollupData RollupData
List * baserestrictinfo
Definition: pathnodes.h:703
NodeTag type
Definition: pathnodes.h:1110
List * ec_derives
Definition: pathnodes.h:936
struct BitmapOrPath BitmapOrPath
AggClauseCosts agg_partial_costs
Definition: pathnodes.h:2440
Relids clause_relids
Definition: pathnodes.h:1958
struct UniquePath UniquePath
Param * param
Definition: pathnodes.h:2282
struct AppendPath AppendPath
int parallel_workers
Definition: pathnodes.h:1121
bool pseudoconstant
Definition: pathnodes.h:1951
bool consider_param_startup
Definition: pathnodes.h:648
RelOptKind
Definition: pathnodes.h:599
List * resultRelations
Definition: pathnodes.h:121
bool is_hashed
Definition: pathnodes.h:1687
ParamPathInfo * param_info
Definition: pathnodes.h:1117
Definition: nodes.h:525
List * part_schemes
Definition: pathnodes.h:303
PartitionwiseAggregateType patype
Definition: pathnodes.h:2447
Oid * sortopfamily
Definition: pathnodes.h:806
struct MergeAppendPath MergeAppendPath
struct BitmapAndPath BitmapAndPath
List * partial_pathlist
Definition: pathnodes.h:657
Oid reltablespace
Definition: pathnodes.h:790
Relids left_relids
Definition: pathnodes.h:1970
List * join_rel_list
Definition: pathnodes.h:244
struct CustomPath CustomPath
struct AggClauseCosts AggClauseCosts
bool ec_below_outer_join
Definition: pathnodes.h:941
uint32 flags
Definition: pathnodes.h:1347
bool hasNonSerial
Definition: pathnodes.h:61
uint32 BlockNumber
Definition: block.h:31
struct JoinPathExtraData JoinPathExtraData
EquivalenceClass * right_ec
Definition: pathnodes.h:1992
List * cheapest_parameterized_paths
Definition: pathnodes.h:661
List * minmax_aggs
Definition: pathnodes.h:327
bool single_copy
Definition: pathnodes.h:1466
bool hypothetical
Definition: pathnodes.h:827
Index baserestrict_min_security
Definition: pathnodes.h:705
UniquePathMethod umethod
Definition: pathnodes.h:1452
struct GatherPath GatherPath
Path * subpath
Definition: pathnodes.h:1426
List * indexclauses
Definition: pathnodes.h:1178
NodeTag type
Definition: pathnodes.h:636
double Selectivity
Definition: nodes.h:658
Index ec_max_security
Definition: pathnodes.h:945
bool hasNonPartial
Definition: pathnodes.h:60
bool useridiscurrent
Definition: pathnodes.h:692
AggSplit aggsplit
Definition: pathnodes.h:1662
bool immediate
Definition: pathnodes.h:826
QualCost transCost
Definition: pathnodes.h:62
List * partitioned_rels
Definition: pathnodes.h:1399
Selectivity bitmapselectivity
Definition: pathnodes.h:1263
double tuples
Definition: pathnodes.h:795
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: pathnodes.h:1710
List ** nullable_partexprs
Definition: pathnodes.h:725
struct ForeignKeyOptInfo ForeignKeyOptInfo
AttrNumber * grouping_map
Definition: pathnodes.h:326
List * fkey_list
Definition: pathnodes.h:294
int tree_height
Definition: pathnodes.h:796
double inner_rows_total
Definition: pathnodes.h:1572
bool hasRecursion
Definition: pathnodes.h:348
struct PlaceHolderInfo PlaceHolderInfo
double numGroups
Definition: pathnodes.h:1663
double numGroups
Definition: pathnodes.h:1735
List * mergeopfamilies
Definition: pathnodes.h:1988
List * translated_vars
Definition: pathnodes.h:2219
struct AppendRelInfo AppendRelInfo
SetOpStrategy
Definition: nodes.h:806
Cost inner_rescan_run_cost
Definition: pathnodes.h:2491
struct EquivalenceClass EquivalenceClass
Oid parent_reltype
Definition: pathnodes.h:2200
Relids syn_lefthand
Definition: pathnodes.h:2135
List * rowMarks
Definition: pathnodes.h:1758
int pk_strategy
Definition: pathnodes.h:1013
double numGroups
Definition: pathnodes.h:1685
InheritanceKind
Definition: pathnodes.h:89
Cost startup
Definition: pathnodes.h:45
double allvisfrac
Definition: pathnodes.h:682
Relids outer_relids
Definition: pathnodes.h:1964
signed int int32
Definition: c.h:346
static struct cvec * eclass(struct vars *v, chr c, int cases)
Definition: regc_locale.c:508
List * bitmapquals
Definition: pathnodes.h:1262
Selectivity norm_selec
Definition: pathnodes.h:1981
List * custom_private
Definition: pathnodes.h:1350
JoinType
Definition: nodes.h:692
int first_partial_path
Definition: pathnodes.h:1376
WindowClause * winclause
Definition: pathnodes.h:1720
struct MaterialPath MaterialPath
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:201
List * bitmapquals
Definition: pathnodes.h:1275
int num_workers
Definition: pathnodes.h:1467
List * rootResultRelations
Definition: pathnodes.h:123
List * multiexpr_params
Definition: pathnodes.h:261
BlockNumber pages
Definition: pathnodes.h:794
NodeTag pathtype
Definition: pathnodes.h:1112
Relids syn_righthand
Definition: pathnodes.h:2136
List * subpaths
Definition: pathnodes.h:1374
PlannerInfo * subroot
Definition: pathnodes.h:685
NodeTag type
Definition: pathnodes.h:1009
SetOpCmd cmd
Definition: pathnodes.h:1730
struct LockRowsPath LockRowsPath
bool dependsOnRole
Definition: pathnodes.h:139
bool consider_startup
Definition: pathnodes.h:647
Definition: dynahash.c:208
struct ParamPathInfo ParamPathInfo
Relids lateral_relids
Definition: pathnodes.h:666
Cost per_tuple
Definition: pathnodes.h:46
const struct CustomPathMethods * methods
Definition: pathnodes.h:1351
int wt_param_id
Definition: pathnodes.h:351
double tuple_fraction
Definition: pathnodes.h:334
Path * subpath
Definition: pathnodes.h:1719
bool skip_mark_restore
Definition: pathnodes.h:1554
RelOptInfo * rel
Definition: pathnodes.h:791
bool amoptionalkey
Definition: pathnodes.h:831
SpecialJoinInfo * sjinfo
Definition: pathnodes.h:2380
struct GroupingSetData GroupingSetData
List ** partexprs
Definition: pathnodes.h:724
bool parallelModeNeeded
Definition: pathnodes.h:143
Relids all_baserels
Definition: pathnodes.h:225
bool pk_nulls_first
Definition: pathnodes.h:1014
List * paramExecTypes
Definition: pathnodes.h:129
Relids param_source_rels
Definition: pathnodes.h:2382
NodeTag type
Definition: pathnodes.h:1071
double limit_tuples
Definition: pathnodes.h:335
struct PathKey PathKey
EquivalenceMember * left_em
Definition: pathnodes.h:1993
struct AggPath AggPath
Cost indextotalcost
Definition: pathnodes.h:1182
Cost startup_cost
Definition: pathnodes.h:1125
List * semi_rhs_exprs
Definition: pathnodes.h:2144
NodeTag type
Definition: pathnodes.h:1043
bool hasLateralRTEs
Definition: pathnodes.h:344
List * indexcols
Definition: pathnodes.h:1227
Path * subpath
Definition: pathnodes.h:1793
struct ModifyTablePath ModifyTablePath
List * joinrestrictinfo
Definition: pathnodes.h:1498
bool parallelModeOK
Definition: pathnodes.h:141
EquivalenceClass * parent_ec
Definition: pathnodes.h:1977
bool partColsUpdated
Definition: pathnodes.h:1776
struct GatherMergePath GatherMergePath
RTEKind
Definition: parsenodes.h:955
Bitmapset * rewindPlanIDs
Definition: pathnodes.h:115
RelOptInfo * parent
Definition: pathnodes.h:1114
AttrNumber indexcol
Definition: pathnodes.h:1226
List * uniq_exprs
Definition: pathnodes.h:1454
Path * bitmapqual
Definition: pathnodes.h:1250
struct ForeignPath ForeignPath
bool outerjoin_delayed
Definition: pathnodes.h:1947
Path path
Definition: pathnodes.h:1631
List * ec_sources
Definition: pathnodes.h:935
struct Path * cheapest_total_path
Definition: pathnodes.h:659
Selectivity rightstartsel
Definition: pathnodes.h:2041
List * curOuterParams
Definition: pathnodes.h:356
struct RelOptInfo RelOptInfo
struct JoinPath JoinPath
Selectivity indexselectivity
Definition: pathnodes.h:1183
List * subplans
Definition: pathnodes.h:111
bool amcanorderbyop
Definition: pathnodes.h:830
struct RestrictInfo * rinfo
Definition: pathnodes.h:1223
List * joininfo
Definition: pathnodes.h:707
Relids ec_relids
Definition: pathnodes.h:937
PlannerGlobal * glob
Definition: pathnodes.h:179
bool outer_is_left
Definition: pathnodes.h:1998
bool partColsUpdated
Definition: pathnodes.h:362
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:694
List * left_join_clauses
Definition: pathnodes.h:270
int nparts
Definition: pathnodes.h:719
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: pathnodes.h:278
List * groupClause
Definition: pathnodes.h:1664
Index * sortgrouprefs
Definition: pathnodes.h:1045
List * mergeclause_list
Definition: pathnodes.h:2378
struct Path Path
unsigned int uint32
Definition: c.h:358
AttrNumber flagColIdx
Definition: pathnodes.h:1733
Relids relids
Definition: pathnodes.h:641
AggStrategy aggstrategy
Definition: pathnodes.h:1698
Selectivity outer_selec
Definition: pathnodes.h:1984
Path * subpath
Definition: pathnodes.h:1465
struct GroupingSetsPath GroupingSetsPath
double total_table_pages
Definition: pathnodes.h:331
Selectivity bitmapselectivity
Definition: pathnodes.h:1276
RelOptInfo * rel
Definition: pathnodes.h:883
struct MinMaxAggPath MinMaxAggPath
int simple_rel_array_size
Definition: pathnodes.h:202
bool amhasgetbitmap
Definition: pathnodes.h:835
List * canon_pathkeys
Definition: pathnodes.h:268
struct PartitionSchemeData * PartitionScheme
Definition: pathnodes.h:405
List * non_unique_for_rels
Definition: pathnodes.h:700
List * indexquals
Definition: pathnodes.h:1224
List * ppilist
Definition: pathnodes.h:656
Index relid
Definition: pathnodes.h:669
List * sort_pathkeys
Definition: pathnodes.h:301
struct PlaceHolderVar PlaceHolderVar
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:209
EquivalenceMember * right_em
Definition: pathnodes.h:1994
Relids lateral_referencers
Definition: pathnodes.h:677
Expr * clause
Definition: pathnodes.h:1943
int numOrderedAggs
Definition: pathnodes.h:59
Path * subpath
Definition: pathnodes.h:1757
struct PlannerGlobal PlannerGlobal
Oid serverid
Definition: pathnodes.h:690
List * ec_opfamilies
Definition: pathnodes.h:932
List * exprs
Definition: pathnodes.h:1044
List * window_pathkeys
Definition: pathnodes.h:299
List * indrestrictinfo
Definition: pathnodes.h:818
Relids direct_lateral_relids
Definition: pathnodes.h:665
Path * outerjoinpath
Definition: pathnodes.h:1495
struct MergeScanSelCache MergeScanSelCache
List * invalItems
Definition: pathnodes.h:127
struct MergePath MergePath
struct GroupResultPath GroupResultPath
bool consider_partitionwise_join
Definition: pathnodes.h:712
NodeTag type
Definition: pathnodes.h:175
JoinPath NestPath
Definition: pathnodes.h:1511
Relids nullable_relids
Definition: pathnodes.h:1967
double inner_rows_total
Definition: pathnodes.h:2502
bool delay_upper_joins
Definition: pathnodes.h:2139
List * indexorderbys
Definition: pathnodes.h:1179
struct RestrictInfo RestrictInfo
struct ProjectSetPath ProjectSetPath
struct IndexClause IndexClause
int rel_parallel_workers
Definition: pathnodes.h:687
List * groupClause
Definition: pathnodes.h:1633
List * append_rel_list
Definition: pathnodes.h:288
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct LimitPath LimitPath
struct AppendRelInfo ** append_rel_array
Definition: pathnodes.h:217
Index lastPHId
Definition: pathnodes.h:131
List * cte_plan_ids
Definition: pathnodes.h:259
List * mmaggregates
Definition: pathnodes.h:1709
Relids ph_lateral
Definition: pathnodes.h:2262
struct PartitionBoundInfoData * boundinfo
Definition: pathnodes.h:720
List * tidquals
Definition: pathnodes.h:1289
Path * subpath
Definition: pathnodes.h:1632
unsigned int Index
Definition: c.h:475
struct GroupPath GroupPath
RTEKind rtekind
Definition: pathnodes.h:671
List * indexlist
Definition: pathnodes.h:678
List * init_plans
Definition: pathnodes.h:257
List * in_operators
Definition: pathnodes.h:1453
double rows
Definition: pathnodes.h:644
bool hasPseudoConstantQuals
Definition: pathnodes.h:346
bool amhasgettuple
Definition: pathnodes.h:834
List * distinct_pathkeys
Definition: pathnodes.h:300
bool is_pushed_down
Definition: pathnodes.h:1945
void * fdw_private
Definition: pathnodes.h:695
Cost total_cost
Definition: pathnodes.h:1126
NodeTag type
Definition: pathnodes.h:787
CostSelector
Definition: pathnodes.h:34
Selectivity left_bucketsize
Definition: pathnodes.h:2004
int firstFlag
Definition: pathnodes.h:1734
double outer_skip_rows
Definition: pathnodes.h:2496
List * pathkeys
Definition: pathnodes.h:1128
Relids right_relids
Definition: pathnodes.h:1971
BlockNumber pages
Definition: pathnodes.h:680
Path path
Definition: pathnodes.h:1488
struct BitmapHeapPath BitmapHeapPath
ParamListInfo boundParams
Definition: pathnodes.h:109
Expr * target
Definition: pathnodes.h:2278
List * eq_classes
Definition: pathnodes.h:264
List ** join_rel_level
Definition: pathnodes.h:254
UniquePathMethod
Definition: pathnodes.h:1441
NodeTag type
Definition: pathnodes.h:107
Path * subpath
Definition: pathnodes.h:1604
double rows
Definition: pathnodes.h:1124
bool parallel_safe
Definition: pathnodes.h:1120
List * lateral_vars
Definition: pathnodes.h:676
struct WindowAggPath WindowAggPath
InheritanceKind inhTargetKind
Definition: pathnodes.h:340
struct PlannerParamItem PlannerParamItem
struct FmgrInfo * partsupfunc
Definition: pathnodes.h:402
Index rootRelation
Definition: pathnodes.h:1775
JoinType jointype
Definition: pathnodes.h:2137
EquivalenceClass * pk_eclass
Definition: pathnodes.h:1011
Bitmapset * outer_params
Definition: pathnodes.h:192
Selectivity left_mcvfreq
Definition: pathnodes.h:2006
List * ppi_clauses
Definition: pathnodes.h:1075
struct RelOptInfo ** part_rels
Definition: pathnodes.h:722
struct Path * non_recursive_path
Definition: pathnodes.h:352
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:466
Oid hashjoinoperator
Definition: pathnodes.h:2001
NodeTag type
Definition: pathnodes.h:1941
QualCost cost
Definition: pathnodes.h:1046
AggSplit
Definition: nodes.h:776
bool ec_has_volatile
Definition: pathnodes.h:940
List * relationOids
Definition: pathnodes.h:125
List * subroots
Definition: pathnodes.h:113
bool amsearcharray
Definition: pathnodes.h:832
struct HTAB * join_rel_hash
Definition: pathnodes.h:245
bool inner_unique
Definition: pathnodes.h:1492
Index qual_security_level
Definition: pathnodes.h:337
bool consider_parallel
Definition: pathnodes.h:649
int nkeycolumns
Definition: pathnodes.h:800
List * innersortkeys
Definition: pathnodes.h:1553
Path * subpath
Definition: pathnodes.h:1660
Oid * opcintype
Definition: pathnodes.h:805
List * partitioned_rels
Definition: pathnodes.h:1373
Bitmapset * Relids
Definition: pathnodes.h:28
Index query_level
Definition: pathnodes.h:181
Oid pk_opfamily
Definition: pathnodes.h:1012
double ppi_rows
Definition: pathnodes.h:1074
Path path
Definition: pathnodes.h:1792
Path path
Definition: pathnodes.h:1288
Oid * opfamily
Definition: pathnodes.h:804
List * withCheckOptionLists
Definition: pathnodes.h:1780
List * finalrtable
Definition: pathnodes.h:117
List * partitioned_child_rels
Definition: pathnodes.h:726
AggStrategy
Definition: nodes.h:754
Bitmapset * keys
Definition: pathnodes.h:885
Index phlevelsup
Definition: pathnodes.h:2065
Index lastRowMarkId
Definition: pathnodes.h:133
AttrNumber max_attr
Definition: pathnodes.h:673
Selectivity match_count
Definition: pathnodes.h:2359
Selectivity right_bucketsize
Definition: pathnodes.h:2005
EquivalenceClass * left_ec
Definition: pathnodes.h:1991
struct JoinCostWorkspace JoinCostWorkspace
Relids nullable_baserels
Definition: pathnodes.h:233
struct RecursiveUnionPath RecursiveUnionPath
List * fdw_private
Definition: pathnodes.h:1320
SetOpCmd
Definition: nodes.h:798
JoinType jointype
Definition: pathnodes.h:1490
List * semi_operators
Definition: pathnodes.h:2143
ScanDirection indexscandir
Definition: pathnodes.h:1181
CmdType operation
Definition: pathnodes.h:1772
struct MinMaxAggInfo MinMaxAggInfo
struct SubqueryScanPath SubqueryScanPath
List * placeholder_list
Definition: pathnodes.h:292
List * resultRelations
Definition: pathnodes.h:1777
Size transitionSpace
Definition: pathnodes.h:64
double numGroups
Definition: pathnodes.h:1676
bool hashable
Definition: pathnodes.h:1686
bool hasHavingQual
Definition: pathnodes.h:345
JoinPath jpath
Definition: pathnodes.h:1550
PartitionScheme part_scheme
Definition: pathnodes.h:718
bool parallel_aware
Definition: pathnodes.h:1119
int * indexkeys
Definition: pathnodes.h:801
List * path_hashclauses
Definition: pathnodes.h:1570
struct PathTarget PathTarget
List * initial_rels
Definition: pathnodes.h:306
List * pathlist
Definition: pathnodes.h:655
Relids ppi_req_outer
Definition: pathnodes.h:1073
MemoryContext planner_cxt
Definition: pathnodes.h:329
List * right_join_clauses
Definition: pathnodes.h:274
Index child_relid
Definition: pathnodes.h:2192
bool * canreturn
Definition: pathnodes.h:809
struct IndexPath IndexPath
bool amsearchnulls
Definition: pathnodes.h:833
List * partition_qual
Definition: pathnodes.h:721
bool * nulls_first
Definition: pathnodes.h:808
struct SetOpPath SetOpPath
Path * subpath
Definition: pathnodes.h:1592
NodeTag type
Definition: pathnodes.h:1222
Index parent_relid
Definition: pathnodes.h:2191
bool * reverse_sort
Definition: pathnodes.h:807
PartitionDirectory partition_directory
Definition: pathnodes.h:147
double inner_skip_rows
Definition: pathnodes.h:2497
List * processed_tlist
Definition: pathnodes.h:323
List * indpred
Definition: pathnodes.h:814
int32 * attr_widths
Definition: pathnodes.h:675
AggClauseCosts agg_final_costs
Definition: pathnodes.h:2441
Node * limitCount
Definition: pathnodes.h:1795
List * finalrowmarks
Definition: pathnodes.h:119
struct SortPath SortPath
Definition: pg_list.h:50
Path path
Definition: pathnodes.h:1617
struct PathTarget * reltarget
Definition: pathnodes.h:652
Relids min_lefthand
Definition: pathnodes.h:2133
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: pathnodes.h:704
List * subplan_params
Definition: pathnodes.h:686
Path path
Definition: pathnodes.h:1728
NodeTag type
Definition: pathnodes.h:2274
CmdType
Definition: nodes.h:668
List * gsets_data
Definition: pathnodes.h:1684
Bitmapset * eclass_indexes
Definition: pathnodes.h:683
Path path
Definition: pathnodes.h:1659
double limit_tuples
Definition: pathnodes.h:1401
struct EquivalenceClass * ec_merged
Definition: pathnodes.h:946
Selectivity rightendsel
Definition: pathnodes.h:2042
bool amcanparallel
Definition: pathnodes.h:836
double Cost
Definition: nodes.h:659
List * scansel_cache
Definition: pathnodes.h:1995
Selectivity leftstartsel
Definition: pathnodes.h:2039
List * ec_members
Definition: pathnodes.h:934
List * indexprs
Definition: pathnodes.h:813
Relids top_parent_relids
Definition: pathnodes.h:714
bool transientPlan
Definition: pathnodes.h:137
List * gsets
Definition: pathnodes.h:1683
bool is_dummy_rel(RelOptInfo *rel)
Definition: joinrels.c:1208
Path * subpath
Definition: pathnodes.h:1451
PlannerInfo * subroot
Definition: pathnodes.h:2279
AttrNumber min_attr
Definition: pathnodes.h:672