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relation.h
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1 /*-------------------------------------------------------------------------
2  *
3  * relation.h
4  * Definitions for planner's internal data structures.
5  *
6  *
7  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/nodes/relation.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef RELATION_H
15 #define RELATION_H
16 
17 #include "access/sdir.h"
18 #include "lib/stringinfo.h"
19 #include "nodes/params.h"
20 #include "nodes/parsenodes.h"
21 #include "storage/block.h"
22 
23 
24 /*
25  * Relids
26  * Set of relation identifiers (indexes into the rangetable).
27  */
28 typedef Bitmapset *Relids;
29 
30 /*
31  * When looking for a "cheapest path", this enum specifies whether we want
32  * cheapest startup cost or cheapest total cost.
33  */
34 typedef enum CostSelector
35 {
37 } CostSelector;
38 
39 /*
40  * The cost estimate produced by cost_qual_eval() includes both a one-time
41  * (startup) cost, and a per-tuple cost.
42  */
43 typedef struct QualCost
44 {
45  Cost startup; /* one-time cost */
46  Cost per_tuple; /* per-evaluation cost */
47 } QualCost;
48 
49 /*
50  * Costing aggregate function execution requires these statistics about
51  * the aggregates to be executed by a given Agg node. Note that the costs
52  * include the execution costs of the aggregates' argument expressions as
53  * well as the aggregate functions themselves. Also, the fields must be
54  * defined so that initializing the struct to zeroes with memset is correct.
55  */
56 typedef struct AggClauseCosts
57 {
58  int numAggs; /* total number of aggregate functions */
59  int numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
60  bool hasNonPartial; /* does any agg not support partial mode? */
61  bool hasNonSerial; /* is any partial agg non-serializable? */
62  QualCost transCost; /* total per-input-row execution costs */
63  Cost finalCost; /* total per-aggregated-row costs */
64  Size transitionSpace; /* space for pass-by-ref transition data */
66 
67 /*
68  * This enum identifies the different types of "upper" (post-scan/join)
69  * relations that we might deal with during planning.
70  */
71 typedef enum UpperRelationKind
72 {
73  UPPERREL_SETOP, /* result of UNION/INTERSECT/EXCEPT, if any */
74  UPPERREL_GROUP_AGG, /* result of grouping/aggregation, if any */
75  UPPERREL_WINDOW, /* result of window functions, if any */
76  UPPERREL_DISTINCT, /* result of "SELECT DISTINCT", if any */
77  UPPERREL_ORDERED, /* result of ORDER BY, if any */
78  UPPERREL_FINAL /* result of any remaining top-level actions */
79  /* NB: UPPERREL_FINAL must be last enum entry; it's used to size arrays */
81 
82 
83 /*----------
84  * PlannerGlobal
85  * Global information for planning/optimization
86  *
87  * PlannerGlobal holds state for an entire planner invocation; this state
88  * is shared across all levels of sub-Queries that exist in the command being
89  * planned.
90  *----------
91  */
92 typedef struct PlannerGlobal
93 {
95 
96  ParamListInfo boundParams; /* Param values provided to planner() */
97 
98  List *subplans; /* Plans for SubPlan nodes */
99 
100  List *subroots; /* PlannerInfos for SubPlan nodes */
101 
102  Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
103 
104  List *finalrtable; /* "flat" rangetable for executor */
105 
106  List *finalrowmarks; /* "flat" list of PlanRowMarks */
107 
108  List *resultRelations; /* "flat" list of integer RT indexes */
109 
110  List *nonleafResultRelations; /* "flat" list of integer RT indexes */
111  List *rootResultRelations; /* "flat" list of integer RT indexes */
112 
113  List *relationOids; /* OIDs of relations the plan depends on */
114 
115  List *invalItems; /* other dependencies, as PlanInvalItems */
116 
117  int nParamExec; /* number of PARAM_EXEC Params used */
118 
119  Index lastPHId; /* highest PlaceHolderVar ID assigned */
120 
121  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
122 
123  int lastPlanNodeId; /* highest plan node ID assigned */
124 
125  bool transientPlan; /* redo plan when TransactionXmin changes? */
126 
127  bool dependsOnRole; /* is plan specific to current role? */
128 
129  bool parallelModeOK; /* parallel mode potentially OK? */
130 
131  bool parallelModeNeeded; /* parallel mode actually required? */
132 
133  char maxParallelHazard; /* worst PROPARALLEL hazard level */
134 } PlannerGlobal;
135 
136 /* macro for fetching the Plan associated with a SubPlan node */
137 #define planner_subplan_get_plan(root, subplan) \
138  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
139 
140 
141 /*----------
142  * PlannerInfo
143  * Per-query information for planning/optimization
144  *
145  * This struct is conventionally called "root" in all the planner routines.
146  * It holds links to all of the planner's working state, in addition to the
147  * original Query. Note that at present the planner extensively modifies
148  * the passed-in Query data structure; someday that should stop.
149  *----------
150  */
151 typedef struct PlannerInfo
152 {
154 
155  Query *parse; /* the Query being planned */
156 
157  PlannerGlobal *glob; /* global info for current planner run */
158 
159  Index query_level; /* 1 at the outermost Query */
160 
161  struct PlannerInfo *parent_root; /* NULL at outermost Query */
162 
163  /*
164  * plan_params contains the expressions that this query level needs to
165  * make available to a lower query level that is currently being planned.
166  * outer_params contains the paramIds of PARAM_EXEC Params that outer
167  * query levels will make available to this query level.
168  */
169  List *plan_params; /* list of PlannerParamItems, see below */
171 
172  /*
173  * simple_rel_array holds pointers to "base rels" and "other rels" (see
174  * comments for RelOptInfo for more info). It is indexed by rangetable
175  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
176  * does not correspond to a base relation, such as a join RTE or an
177  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
178  */
179  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
180  int simple_rel_array_size; /* allocated size of array */
181 
182  /*
183  * simple_rte_array is the same length as simple_rel_array and holds
184  * pointers to the associated rangetable entries. This lets us avoid
185  * rt_fetch(), which can be a bit slow once large inheritance sets have
186  * been expanded.
187  */
188  RangeTblEntry **simple_rte_array; /* rangetable as an array */
189 
190  /*
191  * all_baserels is a Relids set of all base relids (but not "other"
192  * relids) in the query; that is, the Relids identifier of the final join
193  * we need to form. This is computed in make_one_rel, just before we
194  * start making Paths.
195  */
197 
198  /*
199  * nullable_baserels is a Relids set of base relids that are nullable by
200  * some outer join in the jointree; these are rels that are potentially
201  * nullable below the WHERE clause, SELECT targetlist, etc. This is
202  * computed in deconstruct_jointree.
203  */
205 
206  /*
207  * join_rel_list is a list of all join-relation RelOptInfos we have
208  * considered in this planning run. For small problems we just scan the
209  * list to do lookups, but when there are many join relations we build a
210  * hash table for faster lookups. The hash table is present and valid
211  * when join_rel_hash is not NULL. Note that we still maintain the list
212  * even when using the hash table for lookups; this simplifies life for
213  * GEQO.
214  */
215  List *join_rel_list; /* list of join-relation RelOptInfos */
216  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
217 
218  /*
219  * When doing a dynamic-programming-style join search, join_rel_level[k]
220  * is a list of all join-relation RelOptInfos of level k, and
221  * join_cur_level is the current level. New join-relation RelOptInfos are
222  * automatically added to the join_rel_level[join_cur_level] list.
223  * join_rel_level is NULL if not in use.
224  */
225  List **join_rel_level; /* lists of join-relation RelOptInfos */
226  int join_cur_level; /* index of list being extended */
227 
228  List *init_plans; /* init SubPlans for query */
229 
230  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
231 
232  List *multiexpr_params; /* List of Lists of Params for MULTIEXPR
233  * subquery outputs */
234 
235  List *eq_classes; /* list of active EquivalenceClasses */
236 
237  List *canon_pathkeys; /* list of "canonical" PathKeys */
238 
239  List *left_join_clauses; /* list of RestrictInfos for mergejoinable
240  * outer join clauses w/nonnullable var on
241  * left */
242 
243  List *right_join_clauses; /* list of RestrictInfos for mergejoinable
244  * outer join clauses w/nonnullable var on
245  * right */
246 
247  List *full_join_clauses; /* list of RestrictInfos for mergejoinable
248  * full join clauses */
249 
250  List *join_info_list; /* list of SpecialJoinInfos */
251 
252  List *append_rel_list; /* list of AppendRelInfos */
253 
254  List *pcinfo_list; /* list of PartitionedChildRelInfos */
255 
256  List *rowMarks; /* list of PlanRowMarks */
257 
258  List *placeholder_list; /* list of PlaceHolderInfos */
259 
260  List *fkey_list; /* list of ForeignKeyOptInfos */
261 
262  List *query_pathkeys; /* desired pathkeys for query_planner() */
263 
264  List *group_pathkeys; /* groupClause pathkeys, if any */
265  List *window_pathkeys; /* pathkeys of bottom window, if any */
266  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
267  List *sort_pathkeys; /* sortClause pathkeys, if any */
268 
269  List *initial_rels; /* RelOptInfos we are now trying to join */
270 
271  /* Use fetch_upper_rel() to get any particular upper rel */
272  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
273 
274  /* Result tlists chosen by grouping_planner for upper-stage processing */
276 
277  /*
278  * grouping_planner passes back its final processed targetlist here, for
279  * use in relabeling the topmost tlist of the finished Plan.
280  */
282 
283  /* Fields filled during create_plan() for use in setrefs.c */
284  AttrNumber *grouping_map; /* for GroupingFunc fixup */
285  List *minmax_aggs; /* List of MinMaxAggInfos */
286 
287  MemoryContext planner_cxt; /* context holding PlannerInfo */
288 
289  double total_table_pages; /* # of pages in all tables of query */
290 
291  double tuple_fraction; /* tuple_fraction passed to query_planner */
292  double limit_tuples; /* limit_tuples passed to query_planner */
293 
294  Index qual_security_level; /* minimum security_level for quals */
295  /* Note: qual_security_level is zero if there are no securityQuals */
296 
297  bool hasInheritedTarget; /* true if parse->resultRelation is an
298  * inheritance child rel */
299  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
300  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
301  bool hasDeletedRTEs; /* true if any RTE was deleted from jointree */
302  bool hasHavingQual; /* true if havingQual was non-null */
303  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
304  * pseudoconstant = true */
305  bool hasRecursion; /* true if planning a recursive WITH item */
306 
307  /* These fields are used only when hasRecursion is true: */
308  int wt_param_id; /* PARAM_EXEC ID for the work table */
309  struct Path *non_recursive_path; /* a path for non-recursive term */
310 
311  /* These fields are workspace for createplan.c */
312  Relids curOuterRels; /* outer rels above current node */
313  List *curOuterParams; /* not-yet-assigned NestLoopParams */
314 
315  /* optional private data for join_search_hook, e.g., GEQO */
317 } PlannerInfo;
318 
319 
320 /*
321  * In places where it's known that simple_rte_array[] must have been prepared
322  * already, we just index into it to fetch RTEs. In code that might be
323  * executed before or after entering query_planner(), use this macro.
324  */
325 #define planner_rt_fetch(rti, root) \
326  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
327  rt_fetch(rti, (root)->parse->rtable))
328 
329 
330 /*----------
331  * RelOptInfo
332  * Per-relation information for planning/optimization
333  *
334  * For planning purposes, a "base rel" is either a plain relation (a table)
335  * or the output of a sub-SELECT or function that appears in the range table.
336  * In either case it is uniquely identified by an RT index. A "joinrel"
337  * is the joining of two or more base rels. A joinrel is identified by
338  * the set of RT indexes for its component baserels. We create RelOptInfo
339  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
340  * simple_rel_array and join_rel_list respectively.
341  *
342  * Note that there is only one joinrel for any given set of component
343  * baserels, no matter what order we assemble them in; so an unordered
344  * set is the right datatype to identify it with.
345  *
346  * We also have "other rels", which are like base rels in that they refer to
347  * single RT indexes; but they are not part of the join tree, and are given
348  * a different RelOptKind to identify them.
349  * Currently the only kind of otherrels are those made for member relations
350  * of an "append relation", that is an inheritance set or UNION ALL subquery.
351  * An append relation has a parent RTE that is a base rel, which represents
352  * the entire append relation. The member RTEs are otherrels. The parent
353  * is present in the query join tree but the members are not. The member
354  * RTEs and otherrels are used to plan the scans of the individual tables or
355  * subqueries of the append set; then the parent baserel is given Append
356  * and/or MergeAppend paths comprising the best paths for the individual
357  * member rels. (See comments for AppendRelInfo for more information.)
358  *
359  * At one time we also made otherrels to represent join RTEs, for use in
360  * handling join alias Vars. Currently this is not needed because all join
361  * alias Vars are expanded to non-aliased form during preprocess_expression.
362  *
363  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
364  * that describe post-scan/join processing steps, such as aggregation.
365  * Many of the fields in these RelOptInfos are meaningless, but their Path
366  * fields always hold Paths showing ways to do that processing step.
367  *
368  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
369  * that we have proven we don't need to join after all.
370  *
371  * Parts of this data structure are specific to various scan and join
372  * mechanisms. It didn't seem worth creating new node types for them.
373  *
374  * relids - Set of base-relation identifiers; it is a base relation
375  * if there is just one, a join relation if more than one
376  * rows - estimated number of tuples in the relation after restriction
377  * clauses have been applied (ie, output rows of a plan for it)
378  * consider_startup - true if there is any value in keeping plain paths for
379  * this rel on the basis of having cheap startup cost
380  * consider_param_startup - the same for parameterized paths
381  * reltarget - Default Path output tlist for this rel; normally contains
382  * Var and PlaceHolderVar nodes for the values we need to
383  * output from this relation.
384  * List is in no particular order, but all rels of an
385  * appendrel set must use corresponding orders.
386  * NOTE: in an appendrel child relation, may contain
387  * arbitrary expressions pulled up from a subquery!
388  * pathlist - List of Path nodes, one for each potentially useful
389  * method of generating the relation
390  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
391  * cheapest_startup_path - the pathlist member with lowest startup cost
392  * (regardless of ordering) among the unparameterized paths;
393  * or NULL if there is no unparameterized path
394  * cheapest_total_path - the pathlist member with lowest total cost
395  * (regardless of ordering) among the unparameterized paths;
396  * or if there is no unparameterized path, the path with lowest
397  * total cost among the paths with minimum parameterization
398  * cheapest_unique_path - for caching cheapest path to produce unique
399  * (no duplicates) output from relation; NULL if not yet requested
400  * cheapest_parameterized_paths - best paths for their parameterizations;
401  * always includes cheapest_total_path, even if that's unparameterized
402  * direct_lateral_relids - rels this rel has direct LATERAL references to
403  * lateral_relids - required outer rels for LATERAL, as a Relids set
404  * (includes both direct and indirect lateral references)
405  *
406  * If the relation is a base relation it will have these fields set:
407  *
408  * relid - RTE index (this is redundant with the relids field, but
409  * is provided for convenience of access)
410  * rtekind - copy of RTE's rtekind field
411  * min_attr, max_attr - range of valid AttrNumbers for rel
412  * attr_needed - array of bitmapsets indicating the highest joinrel
413  * in which each attribute is needed; if bit 0 is set then
414  * the attribute is needed as part of final targetlist
415  * attr_widths - cache space for per-attribute width estimates;
416  * zero means not computed yet
417  * lateral_vars - lateral cross-references of rel, if any (list of
418  * Vars and PlaceHolderVars)
419  * lateral_referencers - relids of rels that reference this one laterally
420  * (includes both direct and indirect lateral references)
421  * indexlist - list of IndexOptInfo nodes for relation's indexes
422  * (always NIL if it's not a table)
423  * pages - number of disk pages in relation (zero if not a table)
424  * tuples - number of tuples in relation (not considering restrictions)
425  * allvisfrac - fraction of disk pages that are marked all-visible
426  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
427  * subplan_params - list of PlannerParamItems to be passed to subquery
428  *
429  * Note: for a subquery, tuples and subroot are not set immediately
430  * upon creation of the RelOptInfo object; they are filled in when
431  * set_subquery_pathlist processes the object.
432  *
433  * For otherrels that are appendrel members, these fields are filled
434  * in just as for a baserel, except we don't bother with lateral_vars.
435  *
436  * If the relation is either a foreign table or a join of foreign tables that
437  * all belong to the same foreign server and are assigned to the same user to
438  * check access permissions as (cf checkAsUser), these fields will be set:
439  *
440  * serverid - OID of foreign server, if foreign table (else InvalidOid)
441  * userid - OID of user to check access as (InvalidOid means current user)
442  * useridiscurrent - we've assumed that userid equals current user
443  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
444  * fdw_private - private state for FDW, if foreign table (else NULL)
445  *
446  * Two fields are used to cache knowledge acquired during the join search
447  * about whether this rel is provably unique when being joined to given other
448  * relation(s), ie, it can have at most one row matching any given row from
449  * that join relation. Currently we only attempt such proofs, and thus only
450  * populate these fields, for base rels; but someday they might be used for
451  * join rels too:
452  *
453  * unique_for_rels - list of Relid sets, each one being a set of other
454  * rels for which this one has been proven unique
455  * non_unique_for_rels - list of Relid sets, each one being a set of
456  * other rels for which we have tried and failed to prove
457  * this one unique
458  *
459  * The presence of the remaining fields depends on the restrictions
460  * and joins that the relation participates in:
461  *
462  * baserestrictinfo - List of RestrictInfo nodes, containing info about
463  * each non-join qualification clause in which this relation
464  * participates (only used for base rels)
465  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
466  * clauses at a single tuple (only used for base rels)
467  * baserestrict_min_security - Smallest security_level found among
468  * clauses in baserestrictinfo
469  * joininfo - List of RestrictInfo nodes, containing info about each
470  * join clause in which this relation participates (but
471  * note this excludes clauses that might be derivable from
472  * EquivalenceClasses)
473  * has_eclass_joins - flag that EquivalenceClass joins are possible
474  *
475  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
476  * base rels, because for a join rel the set of clauses that are treated as
477  * restrict clauses varies depending on which sub-relations we choose to join.
478  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
479  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
480  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
481  * and should not be processed again at the level of {1 2 3}.) Therefore,
482  * the restrictinfo list in the join case appears in individual JoinPaths
483  * (field joinrestrictinfo), not in the parent relation. But it's OK for
484  * the RelOptInfo to store the joininfo list, because that is the same
485  * for a given rel no matter how we form it.
486  *
487  * We store baserestrictcost in the RelOptInfo (for base relations) because
488  * we know we will need it at least once (to price the sequential scan)
489  * and may need it multiple times to price index scans.
490  *----------
491  */
492 typedef enum RelOptKind
493 {
499 } RelOptKind;
500 
501 /*
502  * Is the given relation a simple relation i.e a base or "other" member
503  * relation?
504  */
505 #define IS_SIMPLE_REL(rel) \
506  ((rel)->reloptkind == RELOPT_BASEREL || \
507  (rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
508 
509 /* Is the given relation a join relation? */
510 #define IS_JOIN_REL(rel) ((rel)->reloptkind == RELOPT_JOINREL)
511 
512 /* Is the given relation an upper relation? */
513 #define IS_UPPER_REL(rel) ((rel)->reloptkind == RELOPT_UPPER_REL)
514 
515 /* Is the given relation an "other" relation? */
516 #define IS_OTHER_REL(rel) ((rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
517 
518 typedef struct RelOptInfo
519 {
521 
523 
524  /* all relations included in this RelOptInfo */
525  Relids relids; /* set of base relids (rangetable indexes) */
526 
527  /* size estimates generated by planner */
528  double rows; /* estimated number of result tuples */
529 
530  /* per-relation planner control flags */
531  bool consider_startup; /* keep cheap-startup-cost paths? */
532  bool consider_param_startup; /* ditto, for parameterized paths? */
533  bool consider_parallel; /* consider parallel paths? */
534 
535  /* default result targetlist for Paths scanning this relation */
536  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
537 
538  /* materialization information */
539  List *pathlist; /* Path structures */
540  List *ppilist; /* ParamPathInfos used in pathlist */
541  List *partial_pathlist; /* partial Paths */
546 
547  /* parameterization information needed for both base rels and join rels */
548  /* (see also lateral_vars and lateral_referencers) */
549  Relids direct_lateral_relids; /* rels directly laterally referenced */
550  Relids lateral_relids; /* minimum parameterization of rel */
551 
552  /* information about a base rel (not set for join rels!) */
554  Oid reltablespace; /* containing tablespace */
555  RTEKind rtekind; /* RELATION, SUBQUERY, FUNCTION, etc */
556  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
557  AttrNumber max_attr; /* largest attrno of rel */
558  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
559  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
560  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
561  Relids lateral_referencers; /* rels that reference me laterally */
562  List *indexlist; /* list of IndexOptInfo */
563  List *statlist; /* list of StatisticExtInfo */
564  BlockNumber pages; /* size estimates derived from pg_class */
565  double tuples;
566  double allvisfrac;
567  PlannerInfo *subroot; /* if subquery */
568  List *subplan_params; /* if subquery */
569  int rel_parallel_workers; /* wanted number of parallel workers */
570 
571  /* Information about foreign tables and foreign joins */
572  Oid serverid; /* identifies server for the table or join */
573  Oid userid; /* identifies user to check access as */
574  bool useridiscurrent; /* join is only valid for current user */
575  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
577  void *fdw_private;
578 
579  /* cache space for remembering if we have proven this relation unique */
580  List *unique_for_rels; /* known unique for these other relid
581  * set(s) */
582  List *non_unique_for_rels; /* known not unique for these set(s) */
583 
584  /* used by various scans and joins: */
585  List *baserestrictinfo; /* RestrictInfo structures (if base rel) */
586  QualCost baserestrictcost; /* cost of evaluating the above */
587  Index baserestrict_min_security; /* min security_level found in
588  * baserestrictinfo */
589  List *joininfo; /* RestrictInfo structures for join clauses
590  * involving this rel */
591  bool has_eclass_joins; /* T means joininfo is incomplete */
592 
593  /* used by "other" relations */
594  Relids top_parent_relids; /* Relids of topmost parents */
595 } RelOptInfo;
596 
597 /*
598  * IndexOptInfo
599  * Per-index information for planning/optimization
600  *
601  * indexkeys[], indexcollations[], opfamily[], and opcintype[]
602  * each have ncolumns entries.
603  *
604  * sortopfamily[], reverse_sort[], and nulls_first[] likewise have
605  * ncolumns entries, if the index is ordered; but if it is unordered,
606  * those pointers are NULL.
607  *
608  * Zeroes in the indexkeys[] array indicate index columns that are
609  * expressions; there is one element in indexprs for each such column.
610  *
611  * For an ordered index, reverse_sort[] and nulls_first[] describe the
612  * sort ordering of a forward indexscan; we can also consider a backward
613  * indexscan, which will generate the reverse ordering.
614  *
615  * The indexprs and indpred expressions have been run through
616  * prepqual.c and eval_const_expressions() for ease of matching to
617  * WHERE clauses. indpred is in implicit-AND form.
618  *
619  * indextlist is a TargetEntry list representing the index columns.
620  * It provides an equivalent base-relation Var for each simple column,
621  * and links to the matching indexprs element for each expression column.
622  *
623  * While most of these fields are filled when the IndexOptInfo is created
624  * (by plancat.c), indrestrictinfo and predOK are set later, in
625  * check_index_predicates().
626  */
627 typedef struct IndexOptInfo
628 {
630 
631  Oid indexoid; /* OID of the index relation */
632  Oid reltablespace; /* tablespace of index (not table) */
633  RelOptInfo *rel; /* back-link to index's table */
634 
635  /* index-size statistics (from pg_class and elsewhere) */
636  BlockNumber pages; /* number of disk pages in index */
637  double tuples; /* number of index tuples in index */
638  int tree_height; /* index tree height, or -1 if unknown */
639 
640  /* index descriptor information */
641  int ncolumns; /* number of columns in index */
642  int *indexkeys; /* column numbers of index's keys, or 0 */
643  Oid *indexcollations; /* OIDs of collations of index columns */
644  Oid *opfamily; /* OIDs of operator families for columns */
645  Oid *opcintype; /* OIDs of opclass declared input data types */
646  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
647  bool *reverse_sort; /* is sort order descending? */
648  bool *nulls_first; /* do NULLs come first in the sort order? */
649  bool *canreturn; /* which index cols can be returned in an
650  * index-only scan? */
651  Oid relam; /* OID of the access method (in pg_am) */
652 
653  List *indexprs; /* expressions for non-simple index columns */
654  List *indpred; /* predicate if a partial index, else NIL */
655 
656  List *indextlist; /* targetlist representing index columns */
657 
658  List *indrestrictinfo; /* parent relation's baserestrictinfo
659  * list, less any conditions implied by
660  * the index's predicate (unless it's a
661  * target rel, see comments in
662  * check_index_predicates()) */
663 
664  bool predOK; /* true if index predicate matches query */
665  bool unique; /* true if a unique index */
666  bool immediate; /* is uniqueness enforced immediately? */
667  bool hypothetical; /* true if index doesn't really exist */
668 
669  /* Remaining fields are copied from the index AM's API struct: */
670  bool amcanorderbyop; /* does AM support order by operator result? */
671  bool amoptionalkey; /* can query omit key for the first column? */
672  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
673  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
674  bool amhasgettuple; /* does AM have amgettuple interface? */
675  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
676  bool amcanparallel; /* does AM support parallel scan? */
677  /* Rather than include amapi.h here, we declare amcostestimate like this */
678  void (*amcostestimate) (); /* AM's cost estimator */
679 } IndexOptInfo;
680 
681 /*
682  * ForeignKeyOptInfo
683  * Per-foreign-key information for planning/optimization
684  *
685  * The per-FK-column arrays can be fixed-size because we allow at most
686  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
687  * nkeys valid entries.
688  */
689 typedef struct ForeignKeyOptInfo
690 {
692 
693  /* Basic data about the foreign key (fetched from catalogs): */
694  Index con_relid; /* RT index of the referencing table */
695  Index ref_relid; /* RT index of the referenced table */
696  int nkeys; /* number of columns in the foreign key */
697  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
698  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
699  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
700 
701  /* Derived info about whether FK's equality conditions match the query: */
702  int nmatched_ec; /* # of FK cols matched by ECs */
703  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
704  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
705  /* Pointer to eclass matching each column's condition, if there is one */
707  /* List of non-EC RestrictInfos matching each column's condition */
710 
711 /*
712  * StatisticExtInfo
713  * Information about extended statistics for planning/optimization
714  *
715  * Each pg_statistic_ext row is represented by one or more nodes of this
716  * type, or even zero if ANALYZE has not computed them.
717  */
718 typedef struct StatisticExtInfo
719 {
721 
722  Oid statOid; /* OID of the statistics row */
723  RelOptInfo *rel; /* back-link to statistic's table */
724  char kind; /* statistic kind of this entry */
725  Bitmapset *keys; /* attnums of the columns covered */
727 
728 /*
729  * EquivalenceClasses
730  *
731  * Whenever we can determine that a mergejoinable equality clause A = B is
732  * not delayed by any outer join, we create an EquivalenceClass containing
733  * the expressions A and B to record this knowledge. If we later find another
734  * equivalence B = C, we add C to the existing EquivalenceClass; this may
735  * require merging two existing EquivalenceClasses. At the end of the qual
736  * distribution process, we have sets of values that are known all transitively
737  * equal to each other, where "equal" is according to the rules of the btree
738  * operator family(s) shown in ec_opfamilies, as well as the collation shown
739  * by ec_collation. (We restrict an EC to contain only equalities whose
740  * operators belong to the same set of opfamilies. This could probably be
741  * relaxed, but for now it's not worth the trouble, since nearly all equality
742  * operators belong to only one btree opclass anyway. Similarly, we suppose
743  * that all or none of the input datatypes are collatable, so that a single
744  * collation value is sufficient.)
745  *
746  * We also use EquivalenceClasses as the base structure for PathKeys, letting
747  * us represent knowledge about different sort orderings being equivalent.
748  * Since every PathKey must reference an EquivalenceClass, we will end up
749  * with single-member EquivalenceClasses whenever a sort key expression has
750  * not been equivalenced to anything else. It is also possible that such an
751  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
752  * which is a case that can't arise otherwise since clauses containing
753  * volatile functions are never considered mergejoinable. We mark such
754  * EquivalenceClasses specially to prevent them from being merged with
755  * ordinary EquivalenceClasses. Also, for volatile expressions we have
756  * to be careful to match the EquivalenceClass to the correct targetlist
757  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
758  * So we record the SortGroupRef of the originating sort clause.
759  *
760  * We allow equality clauses appearing below the nullable side of an outer join
761  * to form EquivalenceClasses, but these have a slightly different meaning:
762  * the included values might be all NULL rather than all the same non-null
763  * values. See src/backend/optimizer/README for more on that point.
764  *
765  * NB: if ec_merged isn't NULL, this class has been merged into another, and
766  * should be ignored in favor of using the pointed-to class.
767  */
768 typedef struct EquivalenceClass
769 {
771 
772  List *ec_opfamilies; /* btree operator family OIDs */
773  Oid ec_collation; /* collation, if datatypes are collatable */
774  List *ec_members; /* list of EquivalenceMembers */
775  List *ec_sources; /* list of generating RestrictInfos */
776  List *ec_derives; /* list of derived RestrictInfos */
777  Relids ec_relids; /* all relids appearing in ec_members, except
778  * for child members (see below) */
779  bool ec_has_const; /* any pseudoconstants in ec_members? */
780  bool ec_has_volatile; /* the (sole) member is a volatile expr */
781  bool ec_below_outer_join; /* equivalence applies below an OJ */
782  bool ec_broken; /* failed to generate needed clauses? */
783  Index ec_sortref; /* originating sortclause label, or 0 */
784  Index ec_min_security; /* minimum security_level in ec_sources */
785  Index ec_max_security; /* maximum security_level in ec_sources */
786  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
788 
789 /*
790  * If an EC contains a const and isn't below-outer-join, any PathKey depending
791  * on it must be redundant, since there's only one possible value of the key.
792  */
793 #define EC_MUST_BE_REDUNDANT(eclass) \
794  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
795 
796 /*
797  * EquivalenceMember - one member expression of an EquivalenceClass
798  *
799  * em_is_child signifies that this element was built by transposing a member
800  * for an appendrel parent relation to represent the corresponding expression
801  * for an appendrel child. These members are used for determining the
802  * pathkeys of scans on the child relation and for explicitly sorting the
803  * child when necessary to build a MergeAppend path for the whole appendrel
804  * tree. An em_is_child member has no impact on the properties of the EC as a
805  * whole; in particular the EC's ec_relids field does NOT include the child
806  * relation. An em_is_child member should never be marked em_is_const nor
807  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
808  * members are not really full-fledged members of the EC, but just reflections
809  * or doppelgangers of real members. Most operations on EquivalenceClasses
810  * should ignore em_is_child members, and those that don't should test
811  * em_relids to make sure they only consider relevant members.
812  *
813  * em_datatype is usually the same as exprType(em_expr), but can be
814  * different when dealing with a binary-compatible opfamily; in particular
815  * anyarray_ops would never work without this. Use em_datatype when
816  * looking up a specific btree operator to work with this expression.
817  */
818 typedef struct EquivalenceMember
819 {
821 
822  Expr *em_expr; /* the expression represented */
823  Relids em_relids; /* all relids appearing in em_expr */
824  Relids em_nullable_relids; /* nullable by lower outer joins */
825  bool em_is_const; /* expression is pseudoconstant? */
826  bool em_is_child; /* derived version for a child relation? */
827  Oid em_datatype; /* the "nominal type" used by the opfamily */
829 
830 /*
831  * PathKeys
832  *
833  * The sort ordering of a path is represented by a list of PathKey nodes.
834  * An empty list implies no known ordering. Otherwise the first item
835  * represents the primary sort key, the second the first secondary sort key,
836  * etc. The value being sorted is represented by linking to an
837  * EquivalenceClass containing that value and including pk_opfamily among its
838  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
839  * This is a convenient method because it makes it trivial to detect
840  * equivalent and closely-related orderings. (See optimizer/README for more
841  * information.)
842  *
843  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
844  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
845  * index types will use btree-compatible strategy numbers.
846  */
847 typedef struct PathKey
848 {
850 
851  EquivalenceClass *pk_eclass; /* the value that is ordered */
852  Oid pk_opfamily; /* btree opfamily defining the ordering */
853  int pk_strategy; /* sort direction (ASC or DESC) */
854  bool pk_nulls_first; /* do NULLs come before normal values? */
855 } PathKey;
856 
857 
858 /*
859  * PathTarget
860  *
861  * This struct contains what we need to know during planning about the
862  * targetlist (output columns) that a Path will compute. Each RelOptInfo
863  * includes a default PathTarget, which its individual Paths may simply
864  * reference. However, in some cases a Path may compute outputs different
865  * from other Paths, and in that case we make a custom PathTarget for it.
866  * For example, an indexscan might return index expressions that would
867  * otherwise need to be explicitly calculated. (Note also that "upper"
868  * relations generally don't have useful default PathTargets.)
869  *
870  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
871  * though those will appear in finished Plans.
872  *
873  * sortgrouprefs[] is an array of the same length as exprs, containing the
874  * corresponding sort/group refnos, or zeroes for expressions not referenced
875  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
876  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
877  * we have not identified sort/group columns in this tlist. This allows us to
878  * deal with sort/group refnos when needed with less expense than including
879  * TargetEntry nodes in the exprs list.
880  */
881 typedef struct PathTarget
882 {
884  List *exprs; /* list of expressions to be computed */
885  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
886  QualCost cost; /* cost of evaluating the expressions */
887  int width; /* estimated avg width of result tuples */
888 } PathTarget;
889 
890 /* Convenience macro to get a sort/group refno from a PathTarget */
891 #define get_pathtarget_sortgroupref(target, colno) \
892  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
893 
894 
895 /*
896  * ParamPathInfo
897  *
898  * All parameterized paths for a given relation with given required outer rels
899  * link to a single ParamPathInfo, which stores common information such as
900  * the estimated rowcount for this parameterization. We do this partly to
901  * avoid recalculations, but mostly to ensure that the estimated rowcount
902  * is in fact the same for every such path.
903  *
904  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
905  * in join cases it's NIL because the set of relevant clauses varies depending
906  * on how the join is formed. The relevant clauses will appear in each
907  * parameterized join path's joinrestrictinfo list, instead.
908  */
909 typedef struct ParamPathInfo
910 {
912 
913  Relids ppi_req_outer; /* rels supplying parameters used by path */
914  double ppi_rows; /* estimated number of result tuples */
915  List *ppi_clauses; /* join clauses available from outer rels */
916 } ParamPathInfo;
917 
918 
919 /*
920  * Type "Path" is used as-is for sequential-scan paths, as well as some other
921  * simple plan types that we don't need any extra information in the path for.
922  * For other path types it is the first component of a larger struct.
923  *
924  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
925  * It is partially redundant with the Path's NodeTag, but allows us to use
926  * the same Path type for multiple Plan types when there is no need to
927  * distinguish the Plan type during path processing.
928  *
929  * "parent" identifies the relation this Path scans, and "pathtarget"
930  * describes the precise set of output columns the Path would compute.
931  * In simple cases all Paths for a given rel share the same targetlist,
932  * which we represent by having path->pathtarget equal to parent->reltarget.
933  *
934  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
935  * relation(s) that provide parameter values to each scan of this path.
936  * That means this path can only be joined to those rels by means of nestloop
937  * joins with this path on the inside. Also note that a parameterized path
938  * is responsible for testing all "movable" joinclauses involving this rel
939  * and the specified outer rel(s).
940  *
941  * "rows" is the same as parent->rows in simple paths, but in parameterized
942  * paths and UniquePaths it can be less than parent->rows, reflecting the
943  * fact that we've filtered by extra join conditions or removed duplicates.
944  *
945  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
946  * ordering of the path's output rows.
947  */
948 typedef struct Path
949 {
951 
952  NodeTag pathtype; /* tag identifying scan/join method */
953 
954  RelOptInfo *parent; /* the relation this path can build */
955  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
956 
957  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
958 
959  bool parallel_aware; /* engage parallel-aware logic? */
960  bool parallel_safe; /* OK to use as part of parallel plan? */
961  int parallel_workers; /* desired # of workers; 0 = not parallel */
962 
963  /* estimated size/costs for path (see costsize.c for more info) */
964  double rows; /* estimated number of result tuples */
965  Cost startup_cost; /* cost expended before fetching any tuples */
966  Cost total_cost; /* total cost (assuming all tuples fetched) */
967 
968  List *pathkeys; /* sort ordering of path's output */
969  /* pathkeys is a List of PathKey nodes; see above */
970 } Path;
971 
972 /* Macro for extracting a path's parameterization relids; beware double eval */
973 #define PATH_REQ_OUTER(path) \
974  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
975 
976 /*----------
977  * IndexPath represents an index scan over a single index.
978  *
979  * This struct is used for both regular indexscans and index-only scans;
980  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
981  *
982  * 'indexinfo' is the index to be scanned.
983  *
984  * 'indexclauses' is a list of index qualification clauses, with implicit
985  * AND semantics across the list. Each clause is a RestrictInfo node from
986  * the query's WHERE or JOIN conditions. An empty list implies a full
987  * index scan.
988  *
989  * 'indexquals' has the same structure as 'indexclauses', but it contains
990  * the actual index qual conditions that can be used with the index.
991  * In simple cases this is identical to 'indexclauses', but when special
992  * indexable operators appear in 'indexclauses', they are replaced by the
993  * derived indexscannable conditions in 'indexquals'.
994  *
995  * 'indexqualcols' is an integer list of index column numbers (zero-based)
996  * of the same length as 'indexquals', showing which index column each qual
997  * is meant to be used with. 'indexquals' is required to be ordered by
998  * index column, so 'indexqualcols' must form a nondecreasing sequence.
999  * (The order of multiple quals for the same index column is unspecified.)
1000  *
1001  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
1002  * been found to be usable as ordering operators for an amcanorderbyop index.
1003  * The list must match the path's pathkeys, ie, one expression per pathkey
1004  * in the same order. These are not RestrictInfos, just bare expressions,
1005  * since they generally won't yield booleans. Also, unlike the case for
1006  * quals, it's guaranteed that each expression has the index key on the left
1007  * side of the operator.
1008  *
1009  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
1010  * of the same length as 'indexorderbys', showing which index column each
1011  * ORDER BY expression is meant to be used with. (There is no restriction
1012  * on which index column each ORDER BY can be used with.)
1013  *
1014  * 'indexscandir' is one of:
1015  * ForwardScanDirection: forward scan of an ordered index
1016  * BackwardScanDirection: backward scan of an ordered index
1017  * NoMovementScanDirection: scan of an unordered index, or don't care
1018  * (The executor doesn't care whether it gets ForwardScanDirection or
1019  * NoMovementScanDirection for an indexscan, but the planner wants to
1020  * distinguish ordered from unordered indexes for building pathkeys.)
1021  *
1022  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
1023  * we need not recompute them when considering using the same index in a
1024  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
1025  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
1026  *----------
1027  */
1028 typedef struct IndexPath
1029 {
1040 } IndexPath;
1041 
1042 /*
1043  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
1044  * instead of directly accessing the heap, followed by AND/OR combinations
1045  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
1046  * Note that the output is always considered unordered, since it will come
1047  * out in physical heap order no matter what the underlying indexes did.
1048  *
1049  * The individual indexscans are represented by IndexPath nodes, and any
1050  * logic on top of them is represented by a tree of BitmapAndPath and
1051  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
1052  * to represent a regular (or index-only) index scan plan, and as the child
1053  * of a BitmapHeapPath that represents scanning the same index using a
1054  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
1055  * always represent the costs to use it as a regular (or index-only)
1056  * IndexScan. The costs of a BitmapIndexScan can be computed using the
1057  * IndexPath's indextotalcost and indexselectivity.
1058  */
1059 typedef struct BitmapHeapPath
1060 {
1062  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1063 } BitmapHeapPath;
1064 
1065 /*
1066  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1067  * part of the substructure of a BitmapHeapPath. The Path structure is
1068  * a bit more heavyweight than we really need for this, but for simplicity
1069  * we make it a derivative of Path anyway.
1070  */
1071 typedef struct BitmapAndPath
1072 {
1074  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1076 } BitmapAndPath;
1077 
1078 /*
1079  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1080  * part of the substructure of a BitmapHeapPath. The Path structure is
1081  * a bit more heavyweight than we really need for this, but for simplicity
1082  * we make it a derivative of Path anyway.
1083  */
1084 typedef struct BitmapOrPath
1085 {
1087  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1089 } BitmapOrPath;
1090 
1091 /*
1092  * TidPath represents a scan by TID
1093  *
1094  * tidquals is an implicitly OR'ed list of qual expressions of the form
1095  * "CTID = pseudoconstant" or "CTID = ANY(pseudoconstant_array)".
1096  * Note they are bare expressions, not RestrictInfos.
1097  */
1098 typedef struct TidPath
1099 {
1101  List *tidquals; /* qual(s) involving CTID = something */
1102 } TidPath;
1103 
1104 /*
1105  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1106  *
1107  * Note that the subpath comes from a different planning domain; for example
1108  * RTE indexes within it mean something different from those known to the
1109  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1110  * interpret the subpath.
1111  */
1112 typedef struct SubqueryScanPath
1113 {
1115  Path *subpath; /* path representing subquery execution */
1117 
1118 /*
1119  * ForeignPath represents a potential scan of a foreign table, foreign join
1120  * or foreign upper-relation.
1121  *
1122  * fdw_private stores FDW private data about the scan. While fdw_private is
1123  * not actually touched by the core code during normal operations, it's
1124  * generally a good idea to use a representation that can be dumped by
1125  * nodeToString(), so that you can examine the structure during debugging
1126  * with tools like pprint().
1127  */
1128 typedef struct ForeignPath
1129 {
1133 } ForeignPath;
1134 
1135 /*
1136  * CustomPath represents a table scan done by some out-of-core extension.
1137  *
1138  * We provide a set of hooks here - which the provider must take care to set
1139  * up correctly - to allow extensions to supply their own methods of scanning
1140  * a relation. For example, a provider might provide GPU acceleration, a
1141  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1142  *
1143  * CustomPaths can be injected into the planning process for a relation by
1144  * set_rel_pathlist_hook functions.
1145  *
1146  * Core code must avoid assuming that the CustomPath is only as large as
1147  * the structure declared here; providers are allowed to make it the first
1148  * element in a larger structure. (Since the planner never copies Paths,
1149  * this doesn't add any complication.) However, for consistency with the
1150  * FDW case, we provide a "custom_private" field in CustomPath; providers
1151  * may prefer to use that rather than define another struct type.
1152  */
1153 
1154 struct CustomPathMethods;
1155 
1156 typedef struct CustomPath
1157 {
1159  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1160  * nodes/extensible.h */
1161  List *custom_paths; /* list of child Path nodes, if any */
1164 } CustomPath;
1165 
1166 /*
1167  * AppendPath represents an Append plan, ie, successive execution of
1168  * several member plans.
1169  *
1170  * Note: it is possible for "subpaths" to contain only one, or even no,
1171  * elements. These cases are optimized during create_append_plan.
1172  * In particular, an AppendPath with no subpaths is a "dummy" path that
1173  * is created to represent the case that a relation is provably empty.
1174  */
1175 typedef struct AppendPath
1176 {
1178  /* RT indexes of non-leaf tables in a partition tree */
1180  List *subpaths; /* list of component Paths */
1181 } AppendPath;
1182 
1183 #define IS_DUMMY_PATH(p) \
1184  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1185 
1186 /* A relation that's been proven empty will have one path that is dummy */
1187 #define IS_DUMMY_REL(r) \
1188  ((r)->cheapest_total_path != NULL && \
1189  IS_DUMMY_PATH((r)->cheapest_total_path))
1190 
1191 /*
1192  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1193  * results from several member plans to produce similarly-sorted output.
1194  */
1195 typedef struct MergeAppendPath
1196 {
1198  /* RT indexes of non-leaf tables in a partition tree */
1200  List *subpaths; /* list of component Paths */
1201  double limit_tuples; /* hard limit on output tuples, or -1 */
1202 } MergeAppendPath;
1203 
1204 /*
1205  * ResultPath represents use of a Result plan node to compute a variable-free
1206  * targetlist with no underlying tables (a "SELECT expressions" query).
1207  * The query could have a WHERE clause, too, represented by "quals".
1208  *
1209  * Note that quals is a list of bare clauses, not RestrictInfos.
1210  */
1211 typedef struct ResultPath
1212 {
1215 } ResultPath;
1216 
1217 /*
1218  * MaterialPath represents use of a Material plan node, i.e., caching of
1219  * the output of its subpath. This is used when the subpath is expensive
1220  * and needs to be scanned repeatedly, or when we need mark/restore ability
1221  * and the subpath doesn't have it.
1222  */
1223 typedef struct MaterialPath
1224 {
1227 } MaterialPath;
1228 
1229 /*
1230  * UniquePath represents elimination of distinct rows from the output of
1231  * its subpath.
1232  *
1233  * This can represent significantly different plans: either hash-based or
1234  * sort-based implementation, or a no-op if the input path can be proven
1235  * distinct already. The decision is sufficiently localized that it's not
1236  * worth having separate Path node types. (Note: in the no-op case, we could
1237  * eliminate the UniquePath node entirely and just return the subpath; but
1238  * it's convenient to have a UniquePath in the path tree to signal upper-level
1239  * routines that the input is known distinct.)
1240  */
1241 typedef enum
1242 {
1243  UNIQUE_PATH_NOOP, /* input is known unique already */
1244  UNIQUE_PATH_HASH, /* use hashing */
1245  UNIQUE_PATH_SORT /* use sorting */
1247 
1248 typedef struct UniquePath
1249 {
1253  List *in_operators; /* equality operators of the IN clause */
1254  List *uniq_exprs; /* expressions to be made unique */
1255 } UniquePath;
1256 
1257 /*
1258  * GatherPath runs several copies of a plan in parallel and collects the
1259  * results. The parallel leader may also execute the plan, unless the
1260  * single_copy flag is set.
1261  */
1262 typedef struct GatherPath
1263 {
1265  Path *subpath; /* path for each worker */
1266  bool single_copy; /* don't execute path more than once */
1267  int num_workers; /* number of workers sought to help */
1268 } GatherPath;
1269 
1270 /*
1271  * GatherMergePath runs several copies of a plan in parallel and
1272  * collects the results. For gather merge parallel leader always execute the
1273  * plan.
1274  */
1275 typedef struct GatherMergePath
1276 {
1278  Path *subpath; /* path for each worker */
1279  int num_workers; /* number of workers sought to help */
1280 } GatherMergePath;
1281 
1282 
1283 /*
1284  * All join-type paths share these fields.
1285  */
1286 
1287 typedef struct JoinPath
1288 {
1290 
1292 
1293  bool inner_unique; /* each outer tuple provably matches no more
1294  * than one inner tuple */
1295 
1296  Path *outerjoinpath; /* path for the outer side of the join */
1297  Path *innerjoinpath; /* path for the inner side of the join */
1298 
1299  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1300 
1301  /*
1302  * See the notes for RelOptInfo and ParamPathInfo to understand why
1303  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1304  * parent RelOptInfo.
1305  */
1306 } JoinPath;
1307 
1308 /*
1309  * A nested-loop path needs no special fields.
1310  */
1311 
1313 
1314 /*
1315  * A mergejoin path has these fields.
1316  *
1317  * Unlike other path types, a MergePath node doesn't represent just a single
1318  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1319  * node itself, there can be a Sort node for the outer input, a Sort node
1320  * for the inner input, and/or a Material node for the inner input. We could
1321  * represent these nodes by separate path nodes, but considering how many
1322  * different merge paths are investigated during a complex join problem,
1323  * it seems better to avoid unnecessary palloc overhead.
1324  *
1325  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1326  * that will be used in the merge.
1327  *
1328  * Note that the mergeclauses are a subset of the parent relation's
1329  * restriction-clause list. Any join clauses that are not mergejoinable
1330  * appear only in the parent's restrict list, and must be checked by a
1331  * qpqual at execution time.
1332  *
1333  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1334  * (resp. inner path) is already ordered appropriately for the
1335  * mergejoin. If it is not NIL then it is a PathKeys list describing
1336  * the ordering that must be created by an explicit Sort node.
1337  *
1338  * skip_mark_restore is TRUE if the executor need not do mark/restore calls.
1339  * Mark/restore overhead is usually required, but can be skipped if we know
1340  * that the executor need find only one match per outer tuple, and that the
1341  * mergeclauses are sufficient to identify a match. In such cases the
1342  * executor can immediately advance the outer relation after processing a
1343  * match, and therefoere it need never back up the inner relation.
1344  *
1345  * materialize_inner is TRUE if a Material node should be placed atop the
1346  * inner input. This may appear with or without an inner Sort step.
1347  */
1348 
1349 typedef struct MergePath
1350 {
1352  List *path_mergeclauses; /* join clauses to be used for merge */
1353  List *outersortkeys; /* keys for explicit sort, if any */
1354  List *innersortkeys; /* keys for explicit sort, if any */
1355  bool skip_mark_restore; /* can executor skip mark/restore? */
1356  bool materialize_inner; /* add Materialize to inner? */
1357 } MergePath;
1358 
1359 /*
1360  * A hashjoin path has these fields.
1361  *
1362  * The remarks above for mergeclauses apply for hashclauses as well.
1363  *
1364  * Hashjoin does not care what order its inputs appear in, so we have
1365  * no need for sortkeys.
1366  */
1367 
1368 typedef struct HashPath
1369 {
1371  List *path_hashclauses; /* join clauses used for hashing */
1372  int num_batches; /* number of batches expected */
1373 } HashPath;
1374 
1375 /*
1376  * ProjectionPath represents a projection (that is, targetlist computation)
1377  *
1378  * Nominally, this path node represents using a Result plan node to do a
1379  * projection step. However, if the input plan node supports projection,
1380  * we can just modify its output targetlist to do the required calculations
1381  * directly, and not need a Result. In some places in the planner we can just
1382  * jam the desired PathTarget into the input path node (and adjust its cost
1383  * accordingly), so we don't need a ProjectionPath. But in other places
1384  * it's necessary to not modify the input path node, so we need a separate
1385  * ProjectionPath node, which is marked dummy to indicate that we intend to
1386  * assign the work to the input plan node. The estimated cost for the
1387  * ProjectionPath node will account for whether a Result will be used or not.
1388  */
1389 typedef struct ProjectionPath
1390 {
1392  Path *subpath; /* path representing input source */
1393  bool dummypp; /* true if no separate Result is needed */
1394 } ProjectionPath;
1395 
1396 /*
1397  * ProjectSetPath represents evaluation of a targetlist that includes
1398  * set-returning function(s), which will need to be implemented by a
1399  * ProjectSet plan node.
1400  */
1401 typedef struct ProjectSetPath
1402 {
1404  Path *subpath; /* path representing input source */
1405 } ProjectSetPath;
1406 
1407 /*
1408  * SortPath represents an explicit sort step
1409  *
1410  * The sort keys are, by definition, the same as path.pathkeys.
1411  *
1412  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1413  * same as the input's pathtarget.
1414  */
1415 typedef struct SortPath
1416 {
1418  Path *subpath; /* path representing input source */
1419 } SortPath;
1420 
1421 /*
1422  * GroupPath represents grouping (of presorted input)
1423  *
1424  * groupClause represents the columns to be grouped on; the input path
1425  * must be at least that well sorted.
1426  *
1427  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1428  */
1429 typedef struct GroupPath
1430 {
1432  Path *subpath; /* path representing input source */
1433  List *groupClause; /* a list of SortGroupClause's */
1434  List *qual; /* quals (HAVING quals), if any */
1435 } GroupPath;
1436 
1437 /*
1438  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1439  *
1440  * The columns to be compared are the first numkeys columns of the path's
1441  * pathkeys. The input is presumed already sorted that way.
1442  */
1443 typedef struct UpperUniquePath
1444 {
1446  Path *subpath; /* path representing input source */
1447  int numkeys; /* number of pathkey columns to compare */
1448 } UpperUniquePath;
1449 
1450 /*
1451  * AggPath represents generic computation of aggregate functions
1452  *
1453  * This may involve plain grouping (but not grouping sets), using either
1454  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1455  * appropriately presorted.
1456  */
1457 typedef struct AggPath
1458 {
1460  Path *subpath; /* path representing input source */
1461  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1462  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1463  double numGroups; /* estimated number of groups in input */
1464  List *groupClause; /* a list of SortGroupClause's */
1465  List *qual; /* quals (HAVING quals), if any */
1466 } AggPath;
1467 
1468 /*
1469  * Various annotations used for grouping sets in the planner.
1470  */
1471 
1472 typedef struct GroupingSetData
1473 {
1475  List *set; /* grouping set as list of sortgrouprefs */
1476  double numGroups; /* est. number of result groups */
1477 } GroupingSetData;
1478 
1479 typedef struct RollupData
1480 {
1482  List *groupClause; /* applicable subset of parse->groupClause */
1483  List *gsets; /* lists of integer indexes into groupClause */
1484  List *gsets_data; /* list of GroupingSetData */
1485  double numGroups; /* est. number of result groups */
1486  bool hashable; /* can be hashed */
1487  bool is_hashed; /* to be implemented as a hashagg */
1488 } RollupData;
1489 
1490 /*
1491  * GroupingSetsPath represents a GROUPING SETS aggregation
1492  */
1493 
1494 typedef struct GroupingSetsPath
1495 {
1497  Path *subpath; /* path representing input source */
1498  AggStrategy aggstrategy; /* basic strategy */
1499  List *rollups; /* list of RollupData */
1500  List *qual; /* quals (HAVING quals), if any */
1502 
1503 /*
1504  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1505  */
1506 typedef struct MinMaxAggPath
1507 {
1509  List *mmaggregates; /* list of MinMaxAggInfo */
1510  List *quals; /* HAVING quals, if any */
1511 } MinMaxAggPath;
1512 
1513 /*
1514  * WindowAggPath represents generic computation of window functions
1515  *
1516  * Note: winpathkeys is separate from path.pathkeys because the actual sort
1517  * order might be an extension of winpathkeys; but createplan.c needs to
1518  * know exactly how many pathkeys match the window clause.
1519  */
1520 typedef struct WindowAggPath
1521 {
1523  Path *subpath; /* path representing input source */
1524  WindowClause *winclause; /* WindowClause we'll be using */
1525  List *winpathkeys; /* PathKeys for PARTITION keys + ORDER keys */
1526 } WindowAggPath;
1527 
1528 /*
1529  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1530  */
1531 typedef struct SetOpPath
1532 {
1534  Path *subpath; /* path representing input source */
1535  SetOpCmd cmd; /* what to do, see nodes.h */
1536  SetOpStrategy strategy; /* how to do it, see nodes.h */
1537  List *distinctList; /* SortGroupClauses identifying target cols */
1538  AttrNumber flagColIdx; /* where is the flag column, if any */
1539  int firstFlag; /* flag value for first input relation */
1540  double numGroups; /* estimated number of groups in input */
1541 } SetOpPath;
1542 
1543 /*
1544  * RecursiveUnionPath represents a recursive UNION node
1545  */
1546 typedef struct RecursiveUnionPath
1547 {
1549  Path *leftpath; /* paths representing input sources */
1551  List *distinctList; /* SortGroupClauses identifying target cols */
1552  int wtParam; /* ID of Param representing work table */
1553  double numGroups; /* estimated number of groups in input */
1555 
1556 /*
1557  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1558  */
1559 typedef struct LockRowsPath
1560 {
1562  Path *subpath; /* path representing input source */
1563  List *rowMarks; /* a list of PlanRowMark's */
1564  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1565 } LockRowsPath;
1566 
1567 /*
1568  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1569  *
1570  * We represent most things that will be in the ModifyTable plan node
1571  * literally, except we have child Path(s) not Plan(s). But analysis of the
1572  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1573  */
1574 typedef struct ModifyTablePath
1575 {
1577  CmdType operation; /* INSERT, UPDATE, or DELETE */
1578  bool canSetTag; /* do we set the command tag/es_processed? */
1579  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1580  /* RT indexes of non-leaf tables in a partition tree */
1582  List *resultRelations; /* integer list of RT indexes */
1583  List *subpaths; /* Path(s) producing source data */
1584  List *subroots; /* per-target-table PlannerInfos */
1585  List *withCheckOptionLists; /* per-target-table WCO lists */
1586  List *returningLists; /* per-target-table RETURNING tlists */
1587  List *rowMarks; /* PlanRowMarks (non-locking only) */
1588  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1589  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1590 } ModifyTablePath;
1591 
1592 /*
1593  * LimitPath represents applying LIMIT/OFFSET restrictions
1594  */
1595 typedef struct LimitPath
1596 {
1598  Path *subpath; /* path representing input source */
1599  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1600  Node *limitCount; /* COUNT parameter, or NULL if none */
1601 } LimitPath;
1602 
1603 
1604 /*
1605  * Restriction clause info.
1606  *
1607  * We create one of these for each AND sub-clause of a restriction condition
1608  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1609  * ANDed, we can use any one of them or any subset of them to filter out
1610  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1611  * stores data used by the optimizer while choosing the best query plan.
1612  *
1613  * If a restriction clause references a single base relation, it will appear
1614  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1615  *
1616  * If a restriction clause references more than one base rel, it will
1617  * appear in the joininfo list of every RelOptInfo that describes a strict
1618  * subset of the base rels mentioned in the clause. The joininfo lists are
1619  * used to drive join tree building by selecting plausible join candidates.
1620  * The clause cannot actually be applied until we have built a join rel
1621  * containing all the base rels it references, however.
1622  *
1623  * When we construct a join rel that includes all the base rels referenced
1624  * in a multi-relation restriction clause, we place that clause into the
1625  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1626  * right sub-path includes all base rels referenced in the clause. The clause
1627  * will be applied at that join level, and will not propagate any further up
1628  * the join tree. (Note: the "predicate migration" code was once intended to
1629  * push restriction clauses up and down the plan tree based on evaluation
1630  * costs, but it's dead code and is unlikely to be resurrected in the
1631  * foreseeable future.)
1632  *
1633  * Note that in the presence of more than two rels, a multi-rel restriction
1634  * might reach different heights in the join tree depending on the join
1635  * sequence we use. So, these clauses cannot be associated directly with
1636  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1637  *
1638  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1639  * equalities that are not outerjoin-delayed) are handled a bit differently.
1640  * Initially we attach them to the EquivalenceClasses that are derived from
1641  * them. When we construct a scan or join path, we look through all the
1642  * EquivalenceClasses and generate derived RestrictInfos representing the
1643  * minimal set of conditions that need to be checked for this particular scan
1644  * or join to enforce that all members of each EquivalenceClass are in fact
1645  * equal in all rows emitted by the scan or join.
1646  *
1647  * When dealing with outer joins we have to be very careful about pushing qual
1648  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1649  * be evaluated exactly at that join node, unless they are "degenerate"
1650  * conditions that reference only Vars from the nullable side of the join.
1651  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1652  * down below the outer join, if they reference any nullable Vars.
1653  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1654  * pushed down to a lower level than its original syntactic placement in the
1655  * join tree would suggest. If an outer join prevents us from pushing a qual
1656  * down to its "natural" semantic level (the level associated with just the
1657  * base rels used in the qual) then we mark the qual with a "required_relids"
1658  * value including more than just the base rels it actually uses. By
1659  * pretending that the qual references all the rels required to form the outer
1660  * join, we prevent it from being evaluated below the outer join's joinrel.
1661  * When we do form the outer join's joinrel, we still need to distinguish
1662  * those quals that are actually in that join's JOIN/ON condition from those
1663  * that appeared elsewhere in the tree and were pushed down to the join rel
1664  * because they used no other rels. That's what the is_pushed_down flag is
1665  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1666  * rels listed in required_relids. A clause that originally came from WHERE
1667  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1668  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1669  * if we decide that it can be pushed down into the nullable side of the join.
1670  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1671  * (In short, is_pushed_down is only false for non-degenerate outer join
1672  * conditions. Possibly we should rename it to reflect that meaning?)
1673  *
1674  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1675  * if the clause's applicability must be delayed due to any outer joins
1676  * appearing below it (ie, it has to be postponed to some join level higher
1677  * than the set of relations it actually references).
1678  *
1679  * There is also an outer_relids field, which is NULL except for outer join
1680  * clauses; for those, it is the set of relids on the outer side of the
1681  * clause's outer join. (These are rels that the clause cannot be applied to
1682  * in parameterized scans, since pushing it into the join's outer side would
1683  * lead to wrong answers.)
1684  *
1685  * There is also a nullable_relids field, which is the set of rels the clause
1686  * references that can be forced null by some outer join below the clause.
1687  *
1688  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1689  * a clause might reference some nullable rels and yet not be
1690  * outerjoin_delayed because it also references all the other rels of the
1691  * outer join(s). A clause that is not outerjoin_delayed can be enforced
1692  * anywhere it is computable.
1693  *
1694  * To handle security-barrier conditions efficiently, we mark RestrictInfo
1695  * nodes with a security_level field, in which higher values identify clauses
1696  * coming from less-trusted sources. The exact semantics are that a clause
1697  * cannot be evaluated before another clause with a lower security_level value
1698  * unless the first clause is leakproof. As with outer-join clauses, this
1699  * creates a reason for clauses to sometimes need to be evaluated higher in
1700  * the join tree than their contents would suggest; and even at a single plan
1701  * node, this rule constrains the order of application of clauses.
1702  *
1703  * In general, the referenced clause might be arbitrarily complex. The
1704  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
1705  * or hashjoin clauses are limited (e.g., no volatile functions). The code
1706  * for each kind of path is responsible for identifying the restrict clauses
1707  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
1708  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
1709  * of the finished Plan node, where they will be enforced by general-purpose
1710  * qual-expression-evaluation code. (But we are still entitled to count
1711  * their selectivity when estimating the result tuple count, if we
1712  * can guess what it is...)
1713  *
1714  * When the referenced clause is an OR clause, we generate a modified copy
1715  * in which additional RestrictInfo nodes are inserted below the top-level
1716  * OR/AND structure. This is a convenience for OR indexscan processing:
1717  * indexquals taken from either the top level or an OR subclause will have
1718  * associated RestrictInfo nodes.
1719  *
1720  * The can_join flag is set true if the clause looks potentially useful as
1721  * a merge or hash join clause, that is if it is a binary opclause with
1722  * nonoverlapping sets of relids referenced in the left and right sides.
1723  * (Whether the operator is actually merge or hash joinable isn't checked,
1724  * however.)
1725  *
1726  * The pseudoconstant flag is set true if the clause contains no Vars of
1727  * the current query level and no volatile functions. Such a clause can be
1728  * pulled out and used as a one-time qual in a gating Result node. We keep
1729  * pseudoconstant clauses in the same lists as other RestrictInfos so that
1730  * the regular clause-pushing machinery can assign them to the correct join
1731  * level, but they need to be treated specially for cost and selectivity
1732  * estimates. Note that a pseudoconstant clause can never be an indexqual
1733  * or merge or hash join clause, so it's of no interest to large parts of
1734  * the planner.
1735  *
1736  * When join clauses are generated from EquivalenceClasses, there may be
1737  * several equally valid ways to enforce join equivalence, of which we need
1738  * apply only one. We mark clauses of this kind by setting parent_ec to
1739  * point to the generating EquivalenceClass. Multiple clauses with the same
1740  * parent_ec in the same join are redundant.
1741  */
1742 
1743 typedef struct RestrictInfo
1744 {
1746 
1747  Expr *clause; /* the represented clause of WHERE or JOIN */
1748 
1749  bool is_pushed_down; /* TRUE if clause was pushed down in level */
1750 
1751  bool outerjoin_delayed; /* TRUE if delayed by lower outer join */
1752 
1753  bool can_join; /* see comment above */
1754 
1755  bool pseudoconstant; /* see comment above */
1756 
1757  bool leakproof; /* TRUE if known to contain no leaked Vars */
1758 
1759  Index security_level; /* see comment above */
1760 
1761  /* The set of relids (varnos) actually referenced in the clause: */
1763 
1764  /* The set of relids required to evaluate the clause: */
1766 
1767  /* If an outer-join clause, the outer-side relations, else NULL: */
1769 
1770  /* The relids used in the clause that are nullable by lower outer joins: */
1772 
1773  /* These fields are set for any binary opclause: */
1774  Relids left_relids; /* relids in left side of clause */
1775  Relids right_relids; /* relids in right side of clause */
1776 
1777  /* This field is NULL unless clause is an OR clause: */
1778  Expr *orclause; /* modified clause with RestrictInfos */
1779 
1780  /* This field is NULL unless clause is potentially redundant: */
1781  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
1782 
1783  /* cache space for cost and selectivity */
1784  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
1785  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
1786  * semantics; -1 if not yet set; >1 means a
1787  * redundant clause */
1788  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
1789  * not yet set */
1790 
1791  /* valid if clause is mergejoinable, else NIL */
1792  List *mergeopfamilies; /* opfamilies containing clause operator */
1793 
1794  /* cache space for mergeclause processing; NULL if not yet set */
1795  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
1796  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
1797  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
1798  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
1799  List *scansel_cache; /* list of MergeScanSelCache structs */
1800 
1801  /* transient workspace for use while considering a specific join path */
1802  bool outer_is_left; /* T = outer var on left, F = on right */
1803 
1804  /* valid if clause is hashjoinable, else InvalidOid: */
1805  Oid hashjoinoperator; /* copy of clause operator */
1806 
1807  /* cache space for hashclause processing; -1 if not yet set */
1808  Selectivity left_bucketsize; /* avg bucketsize of left side */
1809  Selectivity right_bucketsize; /* avg bucketsize of right side */
1810  Selectivity left_mcvfreq; /* left side's most common val's freq */
1811  Selectivity right_mcvfreq; /* right side's most common val's freq */
1812 } RestrictInfo;
1813 
1814 /*
1815  * Since mergejoinscansel() is a relatively expensive function, and would
1816  * otherwise be invoked many times while planning a large join tree,
1817  * we go out of our way to cache its results. Each mergejoinable
1818  * RestrictInfo carries a list of the specific sort orderings that have
1819  * been considered for use with it, and the resulting selectivities.
1820  */
1821 typedef struct MergeScanSelCache
1822 {
1823  /* Ordering details (cache lookup key) */
1824  Oid opfamily; /* btree opfamily defining the ordering */
1825  Oid collation; /* collation for the ordering */
1826  int strategy; /* sort direction (ASC or DESC) */
1827  bool nulls_first; /* do NULLs come before normal values? */
1828  /* Results */
1829  Selectivity leftstartsel; /* first-join fraction for clause left side */
1830  Selectivity leftendsel; /* last-join fraction for clause left side */
1831  Selectivity rightstartsel; /* first-join fraction for clause right side */
1832  Selectivity rightendsel; /* last-join fraction for clause right side */
1834 
1835 /*
1836  * Placeholder node for an expression to be evaluated below the top level
1837  * of a plan tree. This is used during planning to represent the contained
1838  * expression. At the end of the planning process it is replaced by either
1839  * the contained expression or a Var referring to a lower-level evaluation of
1840  * the contained expression. Typically the evaluation occurs below an outer
1841  * join, and Var references above the outer join might thereby yield NULL
1842  * instead of the expression value.
1843  *
1844  * Although the planner treats this as an expression node type, it is not
1845  * recognized by the parser or executor, so we declare it here rather than
1846  * in primnodes.h.
1847  */
1848 
1849 typedef struct PlaceHolderVar
1850 {
1852  Expr *phexpr; /* the represented expression */
1853  Relids phrels; /* base relids syntactically within expr src */
1854  Index phid; /* ID for PHV (unique within planner run) */
1855  Index phlevelsup; /* > 0 if PHV belongs to outer query */
1856 } PlaceHolderVar;
1857 
1858 /*
1859  * "Special join" info.
1860  *
1861  * One-sided outer joins constrain the order of joining partially but not
1862  * completely. We flatten such joins into the planner's top-level list of
1863  * relations to join, but record information about each outer join in a
1864  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
1865  * join_info_list.
1866  *
1867  * Similarly, semijoins and antijoins created by flattening IN (subselect)
1868  * and EXISTS(subselect) clauses create partial constraints on join order.
1869  * These are likewise recorded in SpecialJoinInfo structs.
1870  *
1871  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
1872  * of planning for them, because this simplifies make_join_rel()'s API.
1873  *
1874  * min_lefthand and min_righthand are the sets of base relids that must be
1875  * available on each side when performing the special join. lhs_strict is
1876  * true if the special join's condition cannot succeed when the LHS variables
1877  * are all NULL (this means that an outer join can commute with upper-level
1878  * outer joins even if it appears in their RHS). We don't bother to set
1879  * lhs_strict for FULL JOINs, however.
1880  *
1881  * It is not valid for either min_lefthand or min_righthand to be empty sets;
1882  * if they were, this would break the logic that enforces join order.
1883  *
1884  * syn_lefthand and syn_righthand are the sets of base relids that are
1885  * syntactically below this special join. (These are needed to help compute
1886  * min_lefthand and min_righthand for higher joins.)
1887  *
1888  * delay_upper_joins is set TRUE if we detect a pushed-down clause that has
1889  * to be evaluated after this join is formed (because it references the RHS).
1890  * Any outer joins that have such a clause and this join in their RHS cannot
1891  * commute with this join, because that would leave noplace to check the
1892  * pushed-down clause. (We don't track this for FULL JOINs, either.)
1893  *
1894  * For a semijoin, we also extract the join operators and their RHS arguments
1895  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
1896  * This is done in support of possibly unique-ifying the RHS, so we don't
1897  * bother unless at least one of semi_can_btree and semi_can_hash can be set
1898  * true. (You might expect that this information would be computed during
1899  * join planning; but it's helpful to have it available during planning of
1900  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
1901  *
1902  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
1903  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
1904  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
1905  *
1906  * For purposes of join selectivity estimation, we create transient
1907  * SpecialJoinInfo structures for regular inner joins; so it is possible
1908  * to have jointype == JOIN_INNER in such a structure, even though this is
1909  * not allowed within join_info_list. We also create transient
1910  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
1911  * cost estimation purposes it is sometimes useful to know the join size under
1912  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
1913  * of course the semi_xxx fields are not set meaningfully within such structs.
1914  */
1915 
1916 typedef struct SpecialJoinInfo
1917 {
1919  Relids min_lefthand; /* base relids in minimum LHS for join */
1920  Relids min_righthand; /* base relids in minimum RHS for join */
1921  Relids syn_lefthand; /* base relids syntactically within LHS */
1922  Relids syn_righthand; /* base relids syntactically within RHS */
1923  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
1924  bool lhs_strict; /* joinclause is strict for some LHS rel */
1925  bool delay_upper_joins; /* can't commute with upper RHS */
1926  /* Remaining fields are set only for JOIN_SEMI jointype: */
1927  bool semi_can_btree; /* true if semi_operators are all btree */
1928  bool semi_can_hash; /* true if semi_operators are all hash */
1929  List *semi_operators; /* OIDs of equality join operators */
1930  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
1931 } SpecialJoinInfo;
1932 
1933 /*
1934  * Append-relation info.
1935  *
1936  * When we expand an inheritable table or a UNION-ALL subselect into an
1937  * "append relation" (essentially, a list of child RTEs), we build an
1938  * AppendRelInfo for each non-partitioned child RTE. The list of
1939  * AppendRelInfos indicates which child RTEs must be included when expanding
1940  * the parent, and each node carries information needed to translate Vars
1941  * referencing the parent into Vars referencing that child.
1942  *
1943  * These structs are kept in the PlannerInfo node's append_rel_list.
1944  * Note that we just throw all the structs into one list, and scan the
1945  * whole list when desiring to expand any one parent. We could have used
1946  * a more complex data structure (eg, one list per parent), but this would
1947  * be harder to update during operations such as pulling up subqueries,
1948  * and not really any easier to scan. Considering that typical queries
1949  * will not have many different append parents, it doesn't seem worthwhile
1950  * to complicate things.
1951  *
1952  * Note: after completion of the planner prep phase, any given RTE is an
1953  * append parent having entries in append_rel_list if and only if its
1954  * "inh" flag is set. We clear "inh" for plain tables that turn out not
1955  * to have inheritance children, and (in an abuse of the original meaning
1956  * of the flag) we set "inh" for subquery RTEs that turn out to be
1957  * flattenable UNION ALL queries. This lets us avoid useless searches
1958  * of append_rel_list.
1959  *
1960  * Note: the data structure assumes that append-rel members are single
1961  * baserels. This is OK for inheritance, but it prevents us from pulling
1962  * up a UNION ALL member subquery if it contains a join. While that could
1963  * be fixed with a more complex data structure, at present there's not much
1964  * point because no improvement in the plan could result.
1965  */
1966 
1967 typedef struct AppendRelInfo
1968 {
1970 
1971  /*
1972  * These fields uniquely identify this append relationship. There can be
1973  * (in fact, always should be) multiple AppendRelInfos for the same
1974  * parent_relid, but never more than one per child_relid, since a given
1975  * RTE cannot be a child of more than one append parent.
1976  */
1977  Index parent_relid; /* RT index of append parent rel */
1978  Index child_relid; /* RT index of append child rel */
1979 
1980  /*
1981  * For an inheritance appendrel, the parent and child are both regular
1982  * relations, and we store their rowtype OIDs here for use in translating
1983  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
1984  * both subqueries with no named rowtype, and we store InvalidOid here.
1985  */
1986  Oid parent_reltype; /* OID of parent's composite type */
1987  Oid child_reltype; /* OID of child's composite type */
1988 
1989  /*
1990  * The N'th element of this list is a Var or expression representing the
1991  * child column corresponding to the N'th column of the parent. This is
1992  * used to translate Vars referencing the parent rel into references to
1993  * the child. A list element is NULL if it corresponds to a dropped
1994  * column of the parent (this is only possible for inheritance cases, not
1995  * UNION ALL). The list elements are always simple Vars for inheritance
1996  * cases, but can be arbitrary expressions in UNION ALL cases.
1997  *
1998  * Notice we only store entries for user columns (attno > 0). Whole-row
1999  * Vars are special-cased, and system columns (attno < 0) need no special
2000  * translation since their attnos are the same for all tables.
2001  *
2002  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
2003  * when copying into a subquery.
2004  */
2005  List *translated_vars; /* Expressions in the child's Vars */
2006 
2007  /*
2008  * We store the parent table's OID here for inheritance, or InvalidOid for
2009  * UNION ALL. This is only needed to help in generating error messages if
2010  * an attempt is made to reference a dropped parent column.
2011  */
2012  Oid parent_reloid; /* OID of parent relation */
2013 } AppendRelInfo;
2014 
2015 /*
2016  * For a partitioned table, this maps its RT index to the list of RT indexes
2017  * of the partitioned child tables in the partition tree. We need to
2018  * separately store this information, because we do not create AppendRelInfos
2019  * for the partitioned child tables of a parent table, since AppendRelInfos
2020  * contain information that is unnecessary for the partitioned child tables.
2021  * The child_rels list must contain at least one element, because the parent
2022  * partitioned table is itself counted as a child.
2023  *
2024  * These structs are kept in the PlannerInfo node's pcinfo_list.
2025  */
2027 {
2029 
2033 
2034 /*
2035  * For each distinct placeholder expression generated during planning, we
2036  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
2037  * This stores info that is needed centrally rather than in each copy of the
2038  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
2039  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
2040  * not just within a query level --- this is so that we need not reassign ID's
2041  * when pulling a subquery into its parent.
2042  *
2043  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
2044  * then allow it to bubble up like a Var until the ph_needed join level.
2045  * ph_needed has the same definition as attr_needed for a regular Var.
2046  *
2047  * The PlaceHolderVar's expression might contain LATERAL references to vars
2048  * coming from outside its syntactic scope. If so, those rels are *not*
2049  * included in ph_eval_at, but they are recorded in ph_lateral.
2050  *
2051  * Notice that when ph_eval_at is a join rather than a single baserel, the
2052  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
2053  * has to be formed below any outer joins that should null the PlaceHolderVar.
2054  *
2055  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
2056  * is actually referenced in the plan tree, so that unreferenced placeholders
2057  * don't result in unnecessary constraints on join order.
2058  */
2059 
2060 typedef struct PlaceHolderInfo
2061 {
2063 
2064  Index phid; /* ID for PH (unique within planner run) */
2065  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
2066  Relids ph_eval_at; /* lowest level we can evaluate value at */
2067  Relids ph_lateral; /* relids of contained lateral refs, if any */
2068  Relids ph_needed; /* highest level the value is needed at */
2069  int32 ph_width; /* estimated attribute width */
2070 } PlaceHolderInfo;
2071 
2072 /*
2073  * This struct describes one potentially index-optimizable MIN/MAX aggregate
2074  * function. MinMaxAggPath contains a list of these, and if we accept that
2075  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
2076  */
2077 typedef struct MinMaxAggInfo
2078 {
2080 
2081  Oid aggfnoid; /* pg_proc Oid of the aggregate */
2082  Oid aggsortop; /* Oid of its sort operator */
2083  Expr *target; /* expression we are aggregating on */
2084  PlannerInfo *subroot; /* modified "root" for planning the subquery */
2085  Path *path; /* access path for subquery */
2086  Cost pathcost; /* estimated cost to fetch first row */
2087  Param *param; /* param for subplan's output */
2088 } MinMaxAggInfo;
2089 
2090 /*
2091  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
2092  * node to another. They can be used to pass values down into subqueries (for
2093  * outer references in subqueries), or up out of subqueries (for the results
2094  * of a subplan), or from a NestLoop plan node into its inner relation (when
2095  * the inner scan is parameterized with values from the outer relation).
2096  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
2097  * the PARAM_EXEC Params it generates.
2098  *
2099  * Outer references are managed via root->plan_params, which is a list of
2100  * PlannerParamItems. While planning a subquery, each parent query level's
2101  * plan_params contains the values required from it by the current subquery.
2102  * During create_plan(), we use plan_params to track values that must be
2103  * passed from outer to inner sides of NestLoop plan nodes.
2104  *
2105  * The item a PlannerParamItem represents can be one of three kinds:
2106  *
2107  * A Var: the slot represents a variable of this level that must be passed
2108  * down because subqueries have outer references to it, or must be passed
2109  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
2110  * will always be zero.
2111  *
2112  * A PlaceHolderVar: this works much like the Var case, except that the
2113  * entry is a PlaceHolderVar node with a contained expression. The PHV
2114  * will have phlevelsup = 0, and the contained expression is adjusted
2115  * to match in level.
2116  *
2117  * An Aggref (with an expression tree representing its argument): the slot
2118  * represents an aggregate expression that is an outer reference for some
2119  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
2120  * is adjusted to match in level.
2121  *
2122  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
2123  * them into one slot, but we do not bother to do that for Aggrefs.
2124  * The scope of duplicate-elimination only extends across the set of
2125  * parameters passed from one query level into a single subquery, or for
2126  * nestloop parameters across the set of nestloop parameters used in a single
2127  * query level. So there is no possibility of a PARAM_EXEC slot being used
2128  * for conflicting purposes.
2129  *
2130  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2131  * from subplans (values that are setParam items for those subplans). These
2132  * IDs need not be tracked via PlannerParamItems, since we do not need any
2133  * duplicate-elimination nor later processing of the represented expressions.
2134  * Instead, we just record the assignment of the slot number by incrementing
2135  * root->glob->nParamExec.
2136  */
2137 typedef struct PlannerParamItem
2138 {
2140 
2141  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2142  int paramId; /* its assigned PARAM_EXEC slot number */
2144 
2145 /*
2146  * When making cost estimates for a SEMI/ANTI/inner_unique join, there are
2147  * some correction factors that are needed in both nestloop and hash joins
2148  * to account for the fact that the executor can stop scanning inner rows
2149  * as soon as it finds a match to the current outer row. These numbers
2150  * depend only on the selected outer and inner join relations, not on the
2151  * particular paths used for them, so it's worthwhile to calculate them
2152  * just once per relation pair not once per considered path. This struct
2153  * is filled by compute_semi_anti_join_factors and must be passed along
2154  * to the join cost estimation functions.
2155  *
2156  * outer_match_frac is the fraction of the outer tuples that are
2157  * expected to have at least one match.
2158  * match_count is the average number of matches expected for
2159  * outer tuples that have at least one match.
2160  */
2161 typedef struct SemiAntiJoinFactors
2162 {
2166 
2167 /*
2168  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2169  *
2170  * restrictlist contains all of the RestrictInfo nodes for restriction
2171  * clauses that apply to this join
2172  * mergeclause_list is a list of RestrictInfo nodes for available
2173  * mergejoin clauses in this join
2174  * inner_unique is true if each outer tuple provably matches no more
2175  * than one inner tuple
2176  * sjinfo is extra info about special joins for selectivity estimation
2177  * semifactors is as shown above (only valid for SEMI/ANTI/inner_unique joins)
2178  * param_source_rels are OK targets for parameterization of result paths
2179  */
2180 typedef struct JoinPathExtraData
2181 {
2189 
2190 /*
2191  * For speed reasons, cost estimation for join paths is performed in two
2192  * phases: the first phase tries to quickly derive a lower bound for the
2193  * join cost, and then we check if that's sufficient to reject the path.
2194  * If not, we come back for a more refined cost estimate. The first phase
2195  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2196  * and possibly additional intermediate values. The second phase takes
2197  * these values as inputs to avoid repeating work.
2198  *
2199  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2200  * so seems best to put it here.)
2201  */
2202 typedef struct JoinCostWorkspace
2203 {
2204  /* Preliminary cost estimates --- must not be larger than final ones! */
2205  Cost startup_cost; /* cost expended before fetching any tuples */
2206  Cost total_cost; /* total cost (assuming all tuples fetched) */
2207 
2208  /* Fields below here should be treated as private to costsize.c */
2209  Cost run_cost; /* non-startup cost components */
2210 
2211  /* private for cost_nestloop code */
2212  Cost inner_run_cost; /* also used by cost_mergejoin code */
2214 
2215  /* private for cost_mergejoin code */
2216  double outer_rows;
2217  double inner_rows;
2220 
2221  /* private for cost_hashjoin code */
2225 
2226 #endif /* RELATION_H */
QualCost eval_cost
Definition: relation.h:1784
bool has_eclass_joins
Definition: relation.h:591
struct ModifyTablePath ModifyTablePath
struct Path * cheapest_unique_path
Definition: relation.h:544
NodeTag type
Definition: relation.h:1481
List * indexorderbycols
Definition: relation.h:1036
char maxParallelHazard
Definition: relation.h:133
List * group_pathkeys
Definition: relation.h:264
struct MinMaxAggPath MinMaxAggPath
List * rowMarks
Definition: relation.h:256
struct ForeignKeyOptInfo ForeignKeyOptInfo
Relids ph_needed
Definition: relation.h:2068
List * qual
Definition: relation.h:1434
bool semi_can_btree
Definition: relation.h:1927
Selectivity leftendsel
Definition: relation.h:1830
List * path_mergeclauses
Definition: relation.h:1352
int join_cur_level
Definition: relation.h:226
List * outersortkeys
Definition: relation.h:1353
List * distinctList
Definition: relation.h:1537
List * unique_for_rels
Definition: relation.h:580
JoinPath jpath
Definition: relation.h:1370
struct GroupingSetData GroupingSetData
PathTarget * pathtarget
Definition: relation.h:955
Query * parse
Definition: relation.h:155
List * statlist
Definition: relation.h:563
List * returningLists
Definition: relation.h:1586
struct PathTarget PathTarget
Index security_level
Definition: relation.h:1759
OnConflictExpr * onconflict
Definition: relation.h:1588
List * groupClause
Definition: relation.h:1482
bool predOK
Definition: relation.h:664
Node * limitOffset
Definition: relation.h:1599
Path * subpath
Definition: relation.h:1446
struct PlaceHolderInfo PlaceHolderInfo
Path path
Definition: relation.h:1030
NodeTag type
Definition: relation.h:1969
Path * subpath
Definition: relation.h:1418
Relids ph_eval_at
Definition: relation.h:2066
List * plan_params
Definition: relation.h:169
PlaceHolderVar * ph_var
Definition: relation.h:2065
IndexOptInfo * indexinfo
Definition: relation.h:1031
SemiAntiJoinFactors semifactors
Definition: relation.h:2186
Index nominalRelation
Definition: relation.h:1579
Oid * indexcollations
Definition: relation.h:643
bool hasJoinRTEs
Definition: relation.h:299
Path * fdw_outerpath
Definition: relation.h:1131
RelOptKind reloptkind
Definition: relation.h:522
Relids * attr_needed
Definition: relation.h:558
List * custom_paths
Definition: relation.h:1161
List * query_pathkeys
Definition: relation.h:262
int num_batches
Definition: relation.h:1372
List * join_info_list
Definition: relation.h:250
Relids required_relids
Definition: relation.h:1765
SetOpStrategy strategy
Definition: relation.h:1536
Relids min_righthand
Definition: relation.h:1920
AggStrategy aggstrategy
Definition: relation.h:1461
bool materialize_inner
Definition: relation.h:1356
void * join_search_private
Definition: relation.h:316
Selectivity right_mcvfreq
Definition: relation.h:1811
Relids curOuterRels
Definition: relation.h:312
NodeTag type
Definition: relation.h:720
List * qual
Definition: relation.h:1465
bool leakproof
Definition: relation.h:1757
Index ec_min_security
Definition: relation.h:784
Expr * orclause
Definition: relation.h:1778
Selectivity outer_match_frac
Definition: relation.h:2163
Path * innerjoinpath
Definition: relation.h:1297
struct BitmapOrPath BitmapOrPath
List * indextlist
Definition: relation.h:656
struct AppendPath AppendPath
struct Path * cheapest_startup_path
Definition: relation.h:542
struct LockRowsPath LockRowsPath
Oid userid
Definition: relation.h:573
struct IndexPath IndexPath
struct CustomPath CustomPath
Relids em_nullable_relids
Definition: relation.h:824
int lastPlanNodeId
Definition: relation.h:123
double tuples
Definition: relation.h:565
Oid reltablespace
Definition: relation.h:554
Path * subpath
Definition: relation.h:1534
List * baserestrictinfo
Definition: relation.h:585
NodeTag type
Definition: relation.h:950
List * ec_derives
Definition: relation.h:776
struct UniquePath UniquePath
List * rowMarks
Definition: relation.h:1587
NodeTag type
Definition: relation.h:1918
struct SpecialJoinInfo SpecialJoinInfo
Relids clause_relids
Definition: relation.h:1762
Param * param
Definition: relation.h:2087
struct JoinPathExtraData JoinPathExtraData
int parallel_workers
Definition: relation.h:961
bool pseudoconstant
Definition: relation.h:1755
RelOptKind
Definition: relation.h:492
bool consider_param_startup
Definition: relation.h:532
struct PlannerInfo PlannerInfo
List * resultRelations
Definition: relation.h:108
struct RollupData RollupData
bool is_hashed
Definition: relation.h:1487
ParamPathInfo * param_info
Definition: relation.h:957
struct EquivalenceMember EquivalenceMember
Index ec_sortref
Definition: relation.h:783
Definition: nodes.h:509
Oid * sortopfamily
Definition: relation.h:646
struct SubqueryScanPath SubqueryScanPath
List * partial_pathlist
Definition: relation.h:541
Oid reltablespace
Definition: relation.h:632
Relids left_relids
Definition: relation.h:1774
List * join_rel_list
Definition: relation.h:215
bool ec_below_outer_join
Definition: relation.h:781
uint32 flags
Definition: relation.h:1159
bool hasNonSerial
Definition: relation.h:61
uint32 BlockNumber
Definition: block.h:31
EquivalenceClass * right_ec
Definition: relation.h:1796
List * cheapest_parameterized_paths
Definition: relation.h:545
List * minmax_aggs
Definition: relation.h:285
bool single_copy
Definition: relation.h:1266
bool hypothetical
Definition: relation.h:667
Index baserestrict_min_security
Definition: relation.h:587
UniquePathMethod umethod
Definition: relation.h:1252
struct WindowAggPath WindowAggPath
Path * subpath
Definition: relation.h:1226
List * indexclauses
Definition: relation.h:1032
NodeTag type
Definition: relation.h:520
double Selectivity
Definition: nodes.h:639
NodeTag type
Definition: relation.h:2062
Index ec_max_security
Definition: relation.h:785
bool hasNonPartial
Definition: relation.h:60
bool useridiscurrent
Definition: relation.h:574
AggSplit aggsplit
Definition: relation.h:1462
bool immediate
Definition: relation.h:666
QualCost transCost
Definition: relation.h:62
List * partitioned_rels
Definition: relation.h:1199
struct ProjectSetPath ProjectSetPath
Selectivity bitmapselectivity
Definition: relation.h:1075
double tuples
Definition: relation.h:637
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: relation.h:1510
UpperRelationKind
Definition: relation.h:71
struct ResultPath ResultPath
AttrNumber * grouping_map
Definition: relation.h:284
List * fkey_list
Definition: relation.h:260
int tree_height
Definition: relation.h:638
struct GatherMergePath GatherMergePath
bool hasRecursion
Definition: relation.h:305
double numGroups
Definition: relation.h:1463
double numGroups
Definition: relation.h:1540
List * mergeopfamilies
Definition: relation.h:1792
List * translated_vars
Definition: relation.h:2005
SetOpStrategy
Definition: nodes.h:787
Cost inner_rescan_run_cost
Definition: relation.h:2213
Oid parent_reltype
Definition: relation.h:1986
Relids syn_lefthand
Definition: relation.h:1921
List * rowMarks
Definition: relation.h:1563
int pk_strategy
Definition: relation.h:853
List * winpathkeys
Definition: relation.h:1525
struct PlaceHolderVar PlaceHolderVar
double numGroups
Definition: relation.h:1485
Cost startup
Definition: relation.h:45
double allvisfrac
Definition: relation.h:566
Relids outer_relids
Definition: relation.h:1768
signed int int32
Definition: c.h:256
List * bitmapquals
Definition: relation.h:1074
Selectivity norm_selec
Definition: relation.h:1785
Path path
Definition: relation.h:1177
List * custom_private
Definition: relation.h:1162
JoinType
Definition: nodes.h:673
struct PlannerGlobal PlannerGlobal
WindowClause * winclause
Definition: relation.h:1524
struct RelOptInfo ** simple_rel_array
Definition: relation.h:179
List * bitmapquals
Definition: relation.h:1087
int num_workers
Definition: relation.h:1267
List * rootResultRelations
Definition: relation.h:111
List * multiexpr_params
Definition: relation.h:232
bool unique
Definition: relation.h:665
BlockNumber pages
Definition: relation.h:636
NodeTag pathtype
Definition: relation.h:952
Relids syn_righthand
Definition: relation.h:1922
List * subpaths
Definition: relation.h:1180
PlannerInfo * subroot
Definition: relation.h:567
NodeTag type
Definition: relation.h:849
SetOpCmd cmd
Definition: relation.h:1535
bool dependsOnRole
Definition: relation.h:127
struct AggPath AggPath
NodeTag type
Definition: relation.h:1474
bool consider_startup
Definition: relation.h:531
Definition: dynahash.c:208
struct MaterialPath MaterialPath
Relids lateral_relids
Definition: relation.h:550
Cost per_tuple
Definition: relation.h:46
const struct CustomPathMethods * methods
Definition: relation.h:1163
List * indexquals
Definition: relation.h:1033
int wt_param_id
Definition: relation.h:308
double tuple_fraction
Definition: relation.h:291
Path * subpath
Definition: relation.h:1523
bool skip_mark_restore
Definition: relation.h:1355
RelOptInfo * rel
Definition: relation.h:633
bool amoptionalkey
Definition: relation.h:671
SpecialJoinInfo * sjinfo
Definition: relation.h:2185
bool parallelModeNeeded
Definition: relation.h:131
Path path
Definition: relation.h:1213
struct AppendRelInfo AppendRelInfo
Relids phrels
Definition: relation.h:1853
Relids all_baserels
Definition: relation.h:196
bool pk_nulls_first
Definition: relation.h:854
Path * path
Definition: relation.h:2085
bool hasDeletedRTEs
Definition: relation.h:301
Expr * phexpr
Definition: relation.h:1852
Relids param_source_rels
Definition: relation.h:2187
NodeTag type
Definition: relation.h:911
double limit_tuples
Definition: relation.h:292
EquivalenceMember * left_em
Definition: relation.h:1797
Cost indextotalcost
Definition: relation.h:1038
Cost startup_cost
Definition: relation.h:965
List * semi_rhs_exprs
Definition: relation.h:1930
NodeTag type
Definition: relation.h:883
Oid conpfeqop[INDEX_MAX_KEYS]
Definition: relation.h:699
bool semi_can_hash
Definition: relation.h:1928
bool hasLateralRTEs
Definition: relation.h:300
Path * subpath
Definition: relation.h:1598
struct PlannerParamItem PlannerParamItem
List * joinrestrictinfo
Definition: relation.h:1299
bool parallelModeOK
Definition: relation.h:129
EquivalenceClass * parent_ec
Definition: relation.h:1781
bool can_join
Definition: relation.h:1753
RTEKind
Definition: parsenodes.h:928
List * subroots
Definition: relation.h:1584
Bitmapset * rewindPlanIDs
Definition: relation.h:102
RelOptInfo * parent
Definition: relation.h:954
List * uniq_exprs
Definition: relation.h:1254
Path * bitmapqual
Definition: relation.h:1062
bool outerjoin_delayed
Definition: relation.h:1751
Path path
Definition: relation.h:1431
List * ec_sources
Definition: relation.h:775
struct Path * cheapest_total_path
Definition: relation.h:543
Selectivity rightstartsel
Definition: relation.h:1831
List * curOuterParams
Definition: relation.h:313
struct SetOpPath SetOpPath
struct IndexOptInfo IndexOptInfo
Selectivity indexselectivity
Definition: relation.h:1039
List * subplans
Definition: relation.h:98
bool amcanorderbyop
Definition: relation.h:670
List * joininfo
Definition: relation.h:589
struct GroupPath GroupPath
Relids ec_relids
Definition: relation.h:777
PlannerGlobal * glob
Definition: relation.h:157
bool outer_is_left
Definition: relation.h:1802
struct FdwRoutine * fdwroutine
Definition: relation.h:576
List * left_join_clauses
Definition: relation.h:239
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: relation.h:247
struct GroupingSetsPath GroupingSetsPath
List * subpaths
Definition: relation.h:1583
List * groupClause
Definition: relation.h:1464
Index * sortgrouprefs
Definition: relation.h:885
List * mergeclause_list
Definition: relation.h:2183
unsigned int uint32
Definition: c.h:268
AttrNumber flagColIdx
Definition: relation.h:1538
Relids relids
Definition: relation.h:525
AggStrategy aggstrategy
Definition: relation.h:1498
Selectivity outer_selec
Definition: relation.h:1788
Path * subpath
Definition: relation.h:1265
struct TidPath TidPath
double total_table_pages
Definition: relation.h:289
struct LimitPath LimitPath
Selectivity bitmapselectivity
Definition: relation.h:1088
struct RecursiveUnionPath RecursiveUnionPath
RelOptInfo * rel
Definition: relation.h:723
int simple_rel_array_size
Definition: relation.h:180
int ncolumns
Definition: relation.h:641
bool amhasgetbitmap
Definition: relation.h:675
List * canon_pathkeys
Definition: relation.h:237
List * non_unique_for_rels
Definition: relation.h:582
List * ppilist
Definition: relation.h:540
Path path
Definition: relation.h:1158
Index relid
Definition: relation.h:553
Bitmapset * Relids
Definition: relation.h:28
List * sort_pathkeys
Definition: relation.h:267
RangeTblEntry ** simple_rte_array
Definition: relation.h:188
struct PlannerInfo * parent_root
Definition: relation.h:161
EquivalenceMember * right_em
Definition: relation.h:1798
Relids lateral_referencers
Definition: relation.h:561
Expr * clause
Definition: relation.h:1747
int numOrderedAggs
Definition: relation.h:59
Path * subpath
Definition: relation.h:1562
struct EquivalenceClass * eclass[INDEX_MAX_KEYS]
Definition: relation.h:706
Oid serverid
Definition: relation.h:572
List * ec_opfamilies
Definition: relation.h:772
List * exprs
Definition: relation.h:884
struct ParamPathInfo ParamPathInfo
struct Path Path
List * window_pathkeys
Definition: relation.h:265
List * indrestrictinfo
Definition: relation.h:658
Relids direct_lateral_relids
Definition: relation.h:549
Path * outerjoinpath
Definition: relation.h:1296
List * invalItems
Definition: relation.h:115
NodeTag type
Definition: relation.h:153
struct MinMaxAggInfo MinMaxAggInfo
Relids nullable_relids
Definition: relation.h:1771
bool delay_upper_joins
Definition: relation.h:1925
struct QualCost QualCost
List * indexorderbys
Definition: relation.h:1035
AttrNumber conkey[INDEX_MAX_KEYS]
Definition: relation.h:697
int rel_parallel_workers
Definition: relation.h:569
List * groupClause
Definition: relation.h:1433
List * append_rel_list
Definition: relation.h:252
Index lastPHId
Definition: relation.h:119
List * cte_plan_ids
Definition: relation.h:230
List * mmaggregates
Definition: relation.h:1509
Relids ph_lateral
Definition: relation.h:2067
List * partitioned_rels
Definition: relation.h:1581
Relids em_relids
Definition: relation.h:823
List * tidquals
Definition: relation.h:1101
List * restrictlist
Definition: relation.h:2182
Path * subpath
Definition: relation.h:1432
unsigned int Index
Definition: c.h:365
struct ForeignPath ForeignPath
RTEKind rtekind
Definition: relation.h:555
List * indexlist
Definition: relation.h:562
List * init_plans
Definition: relation.h:228
List * in_operators
Definition: relation.h:1253
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct MergeScanSelCache MergeScanSelCache
struct RestrictInfo RestrictInfo
double rows
Definition: relation.h:528
bool hasPseudoConstantQuals
Definition: relation.h:303
bool amhasgettuple
Definition: relation.h:674
Cost finalCost
Definition: relation.h:63
List * distinct_pathkeys
Definition: relation.h:266
bool is_pushed_down
Definition: relation.h:1749
void * fdw_private
Definition: relation.h:577
Cost total_cost
Definition: relation.h:966
NodeTag type
Definition: relation.h:629
Selectivity left_bucketsize
Definition: relation.h:1808
int firstFlag
Definition: relation.h:1539
double outer_skip_rows
Definition: relation.h:2218
List * pathkeys
Definition: relation.h:968
struct GatherPath GatherPath
List * nonleafResultRelations
Definition: relation.h:110
Relids right_relids
Definition: relation.h:1775
BlockNumber pages
Definition: relation.h:564
Path path
Definition: relation.h:1289
ParamListInfo boundParams
Definition: relation.h:96
struct AggClauseCosts AggClauseCosts
Expr * target
Definition: relation.h:2083
List * pcinfo_list
Definition: relation.h:254
List * eq_classes
Definition: relation.h:235
List ** join_rel_level
Definition: relation.h:225
NodeTag type
Definition: relation.h:94
JoinPath NestPath
Definition: relation.h:1312
Path * subpath
Definition: relation.h:1404
double rows
Definition: relation.h:964
bool parallel_safe
Definition: relation.h:960
List * lateral_vars
Definition: relation.h:560
bool hasInheritedTarget
Definition: relation.h:297
List * quals
Definition: relation.h:1214
JoinType jointype
Definition: relation.h:1923
EquivalenceClass * pk_eclass
Definition: relation.h:851
Bitmapset * outer_params
Definition: relation.h:170
Selectivity left_mcvfreq
Definition: relation.h:1810
List * ppi_clauses
Definition: relation.h:915
struct Path * non_recursive_path
Definition: relation.h:309
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:356
Oid hashjoinoperator
Definition: relation.h:1805
NodeTag type
Definition: relation.h:1745
QualCost cost
Definition: relation.h:886
AggSplit
Definition: nodes.h:757
bool ec_has_volatile
Definition: relation.h:780
List * relationOids
Definition: relation.h:113
struct HashPath HashPath
List * subroots
Definition: relation.h:100
bool amsearcharray
Definition: relation.h:672
struct HTAB * join_rel_hash
Definition: relation.h:216
CostSelector
Definition: relation.h:34
struct JoinPath JoinPath
bool inner_unique
Definition: relation.h:1293
Index qual_security_level
Definition: relation.h:294
bool consider_parallel
Definition: relation.h:533
List * innersortkeys
Definition: relation.h:1354
Path * subpath
Definition: relation.h:1460
Oid * opcintype
Definition: relation.h:645
struct EquivalenceClass EquivalenceClass
List * partitioned_rels
Definition: relation.h:1179
Index query_level
Definition: relation.h:159
Oid pk_opfamily
Definition: relation.h:852
struct JoinCostWorkspace JoinCostWorkspace
Path * subpath
Definition: relation.h:1278
struct SortPath SortPath
double ppi_rows
Definition: relation.h:914
Path path
Definition: relation.h:1597
Path path
Definition: relation.h:1100
struct PartitionedChildRelInfo PartitionedChildRelInfo
Oid child_reltype
Definition: relation.h:1987
Oid * opfamily
Definition: relation.h:644
List * withCheckOptionLists
Definition: relation.h:1585
List * indexqualcols
Definition: relation.h:1034
List * finalrtable
Definition: relation.h:104
int width
Definition: relation.h:887
AggStrategy
Definition: nodes.h:735
Bitmapset * keys
Definition: relation.h:725
Index phlevelsup
Definition: relation.h:1855
Index lastRowMarkId
Definition: relation.h:121
AttrNumber max_attr
Definition: relation.h:557
Selectivity match_count
Definition: relation.h:2164
Selectivity right_bucketsize
Definition: relation.h:1809
EquivalenceClass * left_ec
Definition: relation.h:1795
Relids nullable_baserels
Definition: relation.h:204
struct MergeAppendPath MergeAppendPath
List * fdw_private
Definition: relation.h:1132
SetOpCmd
Definition: nodes.h:779
JoinType jointype
Definition: relation.h:1291
List * semi_operators
Definition: relation.h:1929
ScanDirection indexscandir
Definition: relation.h:1037
CmdType operation
Definition: relation.h:1577
List * placeholder_list
Definition: relation.h:258
List * resultRelations
Definition: relation.h:1582
int nParamExec
Definition: relation.h:117
struct StatisticExtInfo StatisticExtInfo
Size transitionSpace
Definition: relation.h:64
double numGroups
Definition: relation.h:1476
bool hashable
Definition: relation.h:1486
struct BitmapHeapPath BitmapHeapPath
bool hasHavingQual
Definition: relation.h:302
struct PathKey PathKey
JoinPath jpath
Definition: relation.h:1351
NodeTag type
Definition: relation.h:770
bool parallel_aware
Definition: relation.h:959
int * indexkeys
Definition: relation.h:642
List * path_hashclauses
Definition: relation.h:1371
struct ProjectionPath ProjectionPath
UniquePathMethod
Definition: relation.h:1241
struct UpperUniquePath UpperUniquePath
List * initial_rels
Definition: relation.h:269
List * pathlist
Definition: relation.h:539
List * subpaths
Definition: relation.h:1200
Relids ppi_req_outer
Definition: relation.h:913
MemoryContext planner_cxt
Definition: relation.h:287
struct MergePath MergePath
List * right_join_clauses
Definition: relation.h:243
Oid indexoid
Definition: relation.h:631
Index child_relid
Definition: relation.h:1978
bool * canreturn
Definition: relation.h:649
bool amsearchnulls
Definition: relation.h:673
Oid parent_reloid
Definition: relation.h:2012
void(* amcostestimate)()
Definition: relation.h:678
bool * nulls_first
Definition: relation.h:648
Path * subpath
Definition: relation.h:1392
Path path
Definition: relation.h:1264
Index parent_relid
Definition: relation.h:1977
bool * reverse_sort
Definition: relation.h:647
double inner_skip_rows
Definition: relation.h:2219
List * processed_tlist
Definition: relation.h:281
List * indpred
Definition: relation.h:654
int32 * attr_widths
Definition: relation.h:559
Node * limitCount
Definition: relation.h:1600
List * finalrowmarks
Definition: relation.h:106
Definition: pg_list.h:45
AttrNumber confkey[INDEX_MAX_KEYS]
Definition: relation.h:698
Path path
Definition: relation.h:1417
struct PathTarget * reltarget
Definition: relation.h:536
Relids min_lefthand
Definition: relation.h:1919
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: relation.h:586
List * rinfos[INDEX_MAX_KEYS]
Definition: relation.h:708
List * subplan_params
Definition: relation.h:568
Path path
Definition: relation.h:1533
NodeTag type
Definition: relation.h:2079
Path path
Definition: relation.h:1250
CmdType
Definition: nodes.h:649
List * gsets_data
Definition: relation.h:1484
Path path
Definition: relation.h:1459
struct RelOptInfo RelOptInfo
Definition: relation.h:948
double limit_tuples
Definition: relation.h:1201
struct EquivalenceClass * ec_merged
Definition: relation.h:786
Selectivity rightendsel
Definition: relation.h:1832
bool amcanparallel
Definition: relation.h:676
double Cost
Definition: nodes.h:640
List * scansel_cache
Definition: relation.h:1799
Selectivity leftstartsel
Definition: relation.h:1829
List * ec_members
Definition: relation.h:774
List * indexprs
Definition: relation.h:653
Relids top_parent_relids
Definition: relation.h:594
bool transientPlan
Definition: relation.h:125
List * gsets
Definition: relation.h:1483
struct PathTarget * upper_targets[UPPERREL_FINAL+1]
Definition: relation.h:275
Path * subpath
Definition: relation.h:1251
PlannerInfo * subroot
Definition: relation.h:2084
struct BitmapAndPath BitmapAndPath
List * upper_rels[UPPERREL_FINAL+1]
Definition: relation.h:272
AttrNumber min_attr
Definition: relation.h:556