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pathnodes.h
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1 /*-------------------------------------------------------------------------
2  *
3  * pathnodes.h
4  * Definitions for planner's internal data structures, especially Paths.
5  *
6  *
7  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/nodes/pathnodes.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef PATHNODES_H
15 #define PATHNODES_H
16 
17 #include "access/sdir.h"
18 #include "lib/stringinfo.h"
19 #include "nodes/params.h"
20 #include "nodes/parsenodes.h"
21 #include "storage/block.h"
22 
23 
24 /*
25  * Relids
26  * Set of relation identifiers (indexes into the rangetable).
27  */
28 typedef Bitmapset *Relids;
29 
30 /*
31  * When looking for a "cheapest path", this enum specifies whether we want
32  * cheapest startup cost or cheapest total cost.
33  */
34 typedef enum CostSelector
35 {
37 } CostSelector;
38 
39 /*
40  * The cost estimate produced by cost_qual_eval() includes both a one-time
41  * (startup) cost, and a per-tuple cost.
42  */
43 typedef struct QualCost
44 {
45  Cost startup; /* one-time cost */
46  Cost per_tuple; /* per-evaluation cost */
47 } QualCost;
48 
49 /*
50  * Costing aggregate function execution requires these statistics about
51  * the aggregates to be executed by a given Agg node. Note that the costs
52  * include the execution costs of the aggregates' argument expressions as
53  * well as the aggregate functions themselves. Also, the fields must be
54  * defined so that initializing the struct to zeroes with memset is correct.
55  */
56 typedef struct AggClauseCosts
57 {
58  QualCost transCost; /* total per-input-row execution costs */
59  QualCost finalCost; /* total per-aggregated-row costs */
60  Size transitionSpace; /* space for pass-by-ref transition data */
62 
63 /*
64  * This enum identifies the different types of "upper" (post-scan/join)
65  * relations that we might deal with during planning.
66  */
67 typedef enum UpperRelationKind
68 {
69  UPPERREL_SETOP, /* result of UNION/INTERSECT/EXCEPT, if any */
70  UPPERREL_PARTIAL_GROUP_AGG, /* result of partial grouping/aggregation, if
71  * any */
72  UPPERREL_GROUP_AGG, /* result of grouping/aggregation, if any */
73  UPPERREL_WINDOW, /* result of window functions, if any */
74  UPPERREL_PARTIAL_DISTINCT, /* result of partial "SELECT DISTINCT", if any */
75  UPPERREL_DISTINCT, /* result of "SELECT DISTINCT", if any */
76  UPPERREL_ORDERED, /* result of ORDER BY, if any */
77  UPPERREL_FINAL /* result of any remaining top-level actions */
78  /* NB: UPPERREL_FINAL must be last enum entry; it's used to size arrays */
80 
81 /*----------
82  * PlannerGlobal
83  * Global information for planning/optimization
84  *
85  * PlannerGlobal holds state for an entire planner invocation; this state
86  * is shared across all levels of sub-Queries that exist in the command being
87  * planned.
88  *----------
89  */
90 typedef struct PlannerGlobal
91 {
93 
94  ParamListInfo boundParams; /* Param values provided to planner() */
95 
96  List *subplans; /* Plans for SubPlan nodes */
97 
98  List *subroots; /* PlannerInfos for SubPlan nodes */
99 
100  Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
101 
102  List *finalrtable; /* "flat" rangetable for executor */
103 
104  List *finalrowmarks; /* "flat" list of PlanRowMarks */
105 
106  List *resultRelations; /* "flat" list of integer RT indexes */
107 
108  List *appendRelations; /* "flat" list of AppendRelInfos */
109 
110  List *relationOids; /* OIDs of relations the plan depends on */
111 
112  List *invalItems; /* other dependencies, as PlanInvalItems */
113 
114  List *paramExecTypes; /* type OIDs for PARAM_EXEC Params */
115 
116  Index lastPHId; /* highest PlaceHolderVar ID assigned */
117 
118  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
119 
120  int lastPlanNodeId; /* highest plan node ID assigned */
121 
122  bool transientPlan; /* redo plan when TransactionXmin changes? */
123 
124  bool dependsOnRole; /* is plan specific to current role? */
125 
126  bool parallelModeOK; /* parallel mode potentially OK? */
127 
128  bool parallelModeNeeded; /* parallel mode actually required? */
129 
130  char maxParallelHazard; /* worst PROPARALLEL hazard level */
131 
132  PartitionDirectory partition_directory; /* partition descriptors */
133 } PlannerGlobal;
134 
135 /* macro for fetching the Plan associated with a SubPlan node */
136 #define planner_subplan_get_plan(root, subplan) \
137  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
138 
139 
140 /*----------
141  * PlannerInfo
142  * Per-query information for planning/optimization
143  *
144  * This struct is conventionally called "root" in all the planner routines.
145  * It holds links to all of the planner's working state, in addition to the
146  * original Query. Note that at present the planner extensively modifies
147  * the passed-in Query data structure; someday that should stop.
148  *
149  * For reasons explained in optimizer/optimizer.h, we define the typedef
150  * either here or in that header, whichever is read first.
151  *----------
152  */
153 #ifndef HAVE_PLANNERINFO_TYPEDEF
154 typedef struct PlannerInfo PlannerInfo;
155 #define HAVE_PLANNERINFO_TYPEDEF 1
156 #endif
157 
159 {
161 
162  Query *parse; /* the Query being planned */
163 
164  PlannerGlobal *glob; /* global info for current planner run */
165 
166  Index query_level; /* 1 at the outermost Query */
167 
168  PlannerInfo *parent_root; /* NULL at outermost Query */
169 
170  /*
171  * plan_params contains the expressions that this query level needs to
172  * make available to a lower query level that is currently being planned.
173  * outer_params contains the paramIds of PARAM_EXEC Params that outer
174  * query levels will make available to this query level.
175  */
176  List *plan_params; /* list of PlannerParamItems, see below */
178 
179  /*
180  * simple_rel_array holds pointers to "base rels" and "other rels" (see
181  * comments for RelOptInfo for more info). It is indexed by rangetable
182  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
183  * does not correspond to a base relation, such as a join RTE or an
184  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
185  */
186  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
187  int simple_rel_array_size; /* allocated size of array */
188 
189  /*
190  * simple_rte_array is the same length as simple_rel_array and holds
191  * pointers to the associated rangetable entries. Using this is a shade
192  * faster than using rt_fetch(), mostly due to fewer indirections.
193  */
194  RangeTblEntry **simple_rte_array; /* rangetable as an array */
195 
196  /*
197  * append_rel_array is the same length as the above arrays, and holds
198  * pointers to the corresponding AppendRelInfo entry indexed by
199  * child_relid, or NULL if the rel is not an appendrel child. The array
200  * itself is not allocated if append_rel_list is empty.
201  */
203 
204  /*
205  * all_baserels is a Relids set of all base relids (but not "other"
206  * relids) in the query; that is, the Relids identifier of the final join
207  * we need to form. This is computed in make_one_rel, just before we
208  * start making Paths.
209  */
211 
212  /*
213  * nullable_baserels is a Relids set of base relids that are nullable by
214  * some outer join in the jointree; these are rels that are potentially
215  * nullable below the WHERE clause, SELECT targetlist, etc. This is
216  * computed in deconstruct_jointree.
217  */
219 
220  /*
221  * join_rel_list is a list of all join-relation RelOptInfos we have
222  * considered in this planning run. For small problems we just scan the
223  * list to do lookups, but when there are many join relations we build a
224  * hash table for faster lookups. The hash table is present and valid
225  * when join_rel_hash is not NULL. Note that we still maintain the list
226  * even when using the hash table for lookups; this simplifies life for
227  * GEQO.
228  */
229  List *join_rel_list; /* list of join-relation RelOptInfos */
230  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
231 
232  /*
233  * When doing a dynamic-programming-style join search, join_rel_level[k]
234  * is a list of all join-relation RelOptInfos of level k, and
235  * join_cur_level is the current level. New join-relation RelOptInfos are
236  * automatically added to the join_rel_level[join_cur_level] list.
237  * join_rel_level is NULL if not in use.
238  */
239  List **join_rel_level; /* lists of join-relation RelOptInfos */
240  int join_cur_level; /* index of list being extended */
241 
242  List *init_plans; /* init SubPlans for query */
243 
244  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
245 
246  List *multiexpr_params; /* List of Lists of Params for MULTIEXPR
247  * subquery outputs */
248 
249  List *eq_classes; /* list of active EquivalenceClasses */
250 
251  bool ec_merging_done; /* set true once ECs are canonical */
252 
253  List *canon_pathkeys; /* list of "canonical" PathKeys */
254 
255  List *left_join_clauses; /* list of RestrictInfos for mergejoinable
256  * outer join clauses w/nonnullable var on
257  * left */
258 
259  List *right_join_clauses; /* list of RestrictInfos for mergejoinable
260  * outer join clauses w/nonnullable var on
261  * right */
262 
263  List *full_join_clauses; /* list of RestrictInfos for mergejoinable
264  * full join clauses */
265 
266  List *join_info_list; /* list of SpecialJoinInfos */
267 
268  /*
269  * all_result_relids is empty for SELECT, otherwise it contains at least
270  * parse->resultRelation. For UPDATE/DELETE across an inheritance or
271  * partitioning tree, the result rel's child relids are added. When using
272  * multi-level partitioning, intermediate partitioned rels are included.
273  * leaf_result_relids is similar except that only actual result tables,
274  * not partitioned tables, are included in it.
275  */
276  Relids all_result_relids; /* set of all result relids */
277  Relids leaf_result_relids; /* set of all leaf relids */
278 
279  /*
280  * Note: for AppendRelInfos describing partitions of a partitioned table,
281  * we guarantee that partitions that come earlier in the partitioned
282  * table's PartitionDesc will appear earlier in append_rel_list.
283  */
284  List *append_rel_list; /* list of AppendRelInfos */
285 
286  List *row_identity_vars; /* list of RowIdentityVarInfos */
287 
288  List *rowMarks; /* list of PlanRowMarks */
289 
290  List *placeholder_list; /* list of PlaceHolderInfos */
291 
292  List *fkey_list; /* list of ForeignKeyOptInfos */
293 
294  List *query_pathkeys; /* desired pathkeys for query_planner() */
295 
296  List *group_pathkeys; /* groupClause pathkeys, if any */
297  List *window_pathkeys; /* pathkeys of bottom window, if any */
298  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
299  List *sort_pathkeys; /* sortClause pathkeys, if any */
300 
301  List *part_schemes; /* Canonicalised partition schemes used in the
302  * query. */
303 
304  List *initial_rels; /* RelOptInfos we are now trying to join */
305 
306  /* Use fetch_upper_rel() to get any particular upper rel */
307  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
308 
309  /* Result tlists chosen by grouping_planner for upper-stage processing */
310  struct PathTarget *upper_targets[UPPERREL_FINAL + 1];
311 
312  /*
313  * The fully-processed targetlist is kept here. It differs from
314  * parse->targetList in that (for INSERT) it's been reordered to match the
315  * target table, and defaults have been filled in. Also, additional
316  * resjunk targets may be present. preprocess_targetlist() does most of
317  * that work, but note that more resjunk targets can get added during
318  * appendrel expansion. (Hence, upper_targets mustn't get set up till
319  * after that.)
320  */
322 
323  /*
324  * For UPDATE, this list contains the target table's attribute numbers to
325  * which the first N entries of processed_tlist are to be assigned. (Any
326  * additional entries in processed_tlist must be resjunk.) DO NOT use the
327  * resnos in processed_tlist to identify the UPDATE target columns.
328  */
330 
331  /* Fields filled during create_plan() for use in setrefs.c */
332  AttrNumber *grouping_map; /* for GroupingFunc fixup */
333  List *minmax_aggs; /* List of MinMaxAggInfos */
334 
335  MemoryContext planner_cxt; /* context holding PlannerInfo */
336 
337  Cardinality total_table_pages; /* # of pages in all non-dummy tables of
338  * query */
339 
340  Selectivity tuple_fraction; /* tuple_fraction passed to query_planner */
341  Cardinality limit_tuples; /* limit_tuples passed to query_planner */
342 
343  Index qual_security_level; /* minimum security_level for quals */
344  /* Note: qual_security_level is zero if there are no securityQuals */
345 
346  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
347  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
348  bool hasHavingQual; /* true if havingQual was non-null */
349  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
350  * pseudoconstant = true */
351  bool hasAlternativeSubPlans; /* true if we've made any of those */
352  bool hasRecursion; /* true if planning a recursive WITH item */
353 
354  /*
355  * Information about aggregates. Filled by preprocess_aggrefs().
356  */
357  List *agginfos; /* AggInfo structs */
358  List *aggtransinfos; /* AggTransInfo structs */
359  int numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
360  bool hasNonPartialAggs; /* does any agg not support partial mode? */
361  bool hasNonSerialAggs; /* is any partial agg non-serializable? */
362 
363  /* These fields are used only when hasRecursion is true: */
364  int wt_param_id; /* PARAM_EXEC ID for the work table */
365  struct Path *non_recursive_path; /* a path for non-recursive term */
366 
367  /* These fields are workspace for createplan.c */
368  Relids curOuterRels; /* outer rels above current node */
369  List *curOuterParams; /* not-yet-assigned NestLoopParams */
370 
371  /* These fields are workspace for setrefs.c */
372  bool *isAltSubplan; /* array corresponding to glob->subplans */
373  bool *isUsedSubplan; /* array corresponding to glob->subplans */
374 
375  /* optional private data for join_search_hook, e.g., GEQO */
377 
378  /* Does this query modify any partition key columns? */
380 };
381 
382 
383 /*
384  * In places where it's known that simple_rte_array[] must have been prepared
385  * already, we just index into it to fetch RTEs. In code that might be
386  * executed before or after entering query_planner(), use this macro.
387  */
388 #define planner_rt_fetch(rti, root) \
389  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
390  rt_fetch(rti, (root)->parse->rtable))
391 
392 /*
393  * If multiple relations are partitioned the same way, all such partitions
394  * will have a pointer to the same PartitionScheme. A list of PartitionScheme
395  * objects is attached to the PlannerInfo. By design, the partition scheme
396  * incorporates only the general properties of the partition method (LIST vs.
397  * RANGE, number of partitioning columns and the type information for each)
398  * and not the specific bounds.
399  *
400  * We store the opclass-declared input data types instead of the partition key
401  * datatypes since the former rather than the latter are used to compare
402  * partition bounds. Since partition key data types and the opclass declared
403  * input data types are expected to be binary compatible (per ResolveOpClass),
404  * both of those should have same byval and length properties.
405  */
406 typedef struct PartitionSchemeData
407 {
408  char strategy; /* partition strategy */
409  int16 partnatts; /* number of partition attributes */
410  Oid *partopfamily; /* OIDs of operator families */
411  Oid *partopcintype; /* OIDs of opclass declared input data types */
412  Oid *partcollation; /* OIDs of partitioning collations */
413 
414  /* Cached information about partition key data types. */
417 
418  /* Cached information about partition comparison functions. */
421 
423 
424 /*----------
425  * RelOptInfo
426  * Per-relation information for planning/optimization
427  *
428  * For planning purposes, a "base rel" is either a plain relation (a table)
429  * or the output of a sub-SELECT or function that appears in the range table.
430  * In either case it is uniquely identified by an RT index. A "joinrel"
431  * is the joining of two or more base rels. A joinrel is identified by
432  * the set of RT indexes for its component baserels. We create RelOptInfo
433  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
434  * simple_rel_array and join_rel_list respectively.
435  *
436  * Note that there is only one joinrel for any given set of component
437  * baserels, no matter what order we assemble them in; so an unordered
438  * set is the right datatype to identify it with.
439  *
440  * We also have "other rels", which are like base rels in that they refer to
441  * single RT indexes; but they are not part of the join tree, and are given
442  * a different RelOptKind to identify them.
443  * Currently the only kind of otherrels are those made for member relations
444  * of an "append relation", that is an inheritance set or UNION ALL subquery.
445  * An append relation has a parent RTE that is a base rel, which represents
446  * the entire append relation. The member RTEs are otherrels. The parent
447  * is present in the query join tree but the members are not. The member
448  * RTEs and otherrels are used to plan the scans of the individual tables or
449  * subqueries of the append set; then the parent baserel is given Append
450  * and/or MergeAppend paths comprising the best paths for the individual
451  * member rels. (See comments for AppendRelInfo for more information.)
452  *
453  * At one time we also made otherrels to represent join RTEs, for use in
454  * handling join alias Vars. Currently this is not needed because all join
455  * alias Vars are expanded to non-aliased form during preprocess_expression.
456  *
457  * We also have relations representing joins between child relations of
458  * different partitioned tables. These relations are not added to
459  * join_rel_level lists as they are not joined directly by the dynamic
460  * programming algorithm.
461  *
462  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
463  * that describe post-scan/join processing steps, such as aggregation.
464  * Many of the fields in these RelOptInfos are meaningless, but their Path
465  * fields always hold Paths showing ways to do that processing step.
466  *
467  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
468  * that we have proven we don't need to join after all.
469  *
470  * Parts of this data structure are specific to various scan and join
471  * mechanisms. It didn't seem worth creating new node types for them.
472  *
473  * relids - Set of base-relation identifiers; it is a base relation
474  * if there is just one, a join relation if more than one
475  * rows - estimated number of tuples in the relation after restriction
476  * clauses have been applied (ie, output rows of a plan for it)
477  * consider_startup - true if there is any value in keeping plain paths for
478  * this rel on the basis of having cheap startup cost
479  * consider_param_startup - the same for parameterized paths
480  * reltarget - Default Path output tlist for this rel; normally contains
481  * Var and PlaceHolderVar nodes for the values we need to
482  * output from this relation.
483  * List is in no particular order, but all rels of an
484  * appendrel set must use corresponding orders.
485  * NOTE: in an appendrel child relation, may contain
486  * arbitrary expressions pulled up from a subquery!
487  * pathlist - List of Path nodes, one for each potentially useful
488  * method of generating the relation
489  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
490  * cheapest_startup_path - the pathlist member with lowest startup cost
491  * (regardless of ordering) among the unparameterized paths;
492  * or NULL if there is no unparameterized path
493  * cheapest_total_path - the pathlist member with lowest total cost
494  * (regardless of ordering) among the unparameterized paths;
495  * or if there is no unparameterized path, the path with lowest
496  * total cost among the paths with minimum parameterization
497  * cheapest_unique_path - for caching cheapest path to produce unique
498  * (no duplicates) output from relation; NULL if not yet requested
499  * cheapest_parameterized_paths - best paths for their parameterizations;
500  * always includes cheapest_total_path, even if that's unparameterized
501  * direct_lateral_relids - rels this rel has direct LATERAL references to
502  * lateral_relids - required outer rels for LATERAL, as a Relids set
503  * (includes both direct and indirect lateral references)
504  *
505  * If the relation is a base relation it will have these fields set:
506  *
507  * relid - RTE index (this is redundant with the relids field, but
508  * is provided for convenience of access)
509  * rtekind - copy of RTE's rtekind field
510  * min_attr, max_attr - range of valid AttrNumbers for rel
511  * attr_needed - array of bitmapsets indicating the highest joinrel
512  * in which each attribute is needed; if bit 0 is set then
513  * the attribute is needed as part of final targetlist
514  * attr_widths - cache space for per-attribute width estimates;
515  * zero means not computed yet
516  * lateral_vars - lateral cross-references of rel, if any (list of
517  * Vars and PlaceHolderVars)
518  * lateral_referencers - relids of rels that reference this one laterally
519  * (includes both direct and indirect lateral references)
520  * indexlist - list of IndexOptInfo nodes for relation's indexes
521  * (always NIL if it's not a table)
522  * pages - number of disk pages in relation (zero if not a table)
523  * tuples - number of tuples in relation (not considering restrictions)
524  * allvisfrac - fraction of disk pages that are marked all-visible
525  * eclass_indexes - EquivalenceClasses that mention this rel (filled
526  * only after EC merging is complete)
527  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
528  * subplan_params - list of PlannerParamItems to be passed to subquery
529  *
530  * Note: for a subquery, tuples and subroot are not set immediately
531  * upon creation of the RelOptInfo object; they are filled in when
532  * set_subquery_pathlist processes the object.
533  *
534  * For otherrels that are appendrel members, these fields are filled
535  * in just as for a baserel, except we don't bother with lateral_vars.
536  *
537  * If the relation is either a foreign table or a join of foreign tables that
538  * all belong to the same foreign server and are assigned to the same user to
539  * check access permissions as (cf checkAsUser), these fields will be set:
540  *
541  * serverid - OID of foreign server, if foreign table (else InvalidOid)
542  * userid - OID of user to check access as (InvalidOid means current user)
543  * useridiscurrent - we've assumed that userid equals current user
544  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
545  * fdw_private - private state for FDW, if foreign table (else NULL)
546  *
547  * Two fields are used to cache knowledge acquired during the join search
548  * about whether this rel is provably unique when being joined to given other
549  * relation(s), ie, it can have at most one row matching any given row from
550  * that join relation. Currently we only attempt such proofs, and thus only
551  * populate these fields, for base rels; but someday they might be used for
552  * join rels too:
553  *
554  * unique_for_rels - list of Relid sets, each one being a set of other
555  * rels for which this one has been proven unique
556  * non_unique_for_rels - list of Relid sets, each one being a set of
557  * other rels for which we have tried and failed to prove
558  * this one unique
559  *
560  * The presence of the following fields depends on the restrictions
561  * and joins that the relation participates in:
562  *
563  * baserestrictinfo - List of RestrictInfo nodes, containing info about
564  * each non-join qualification clause in which this relation
565  * participates (only used for base rels)
566  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
567  * clauses at a single tuple (only used for base rels)
568  * baserestrict_min_security - Smallest security_level found among
569  * clauses in baserestrictinfo
570  * joininfo - List of RestrictInfo nodes, containing info about each
571  * join clause in which this relation participates (but
572  * note this excludes clauses that might be derivable from
573  * EquivalenceClasses)
574  * has_eclass_joins - flag that EquivalenceClass joins are possible
575  *
576  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
577  * base rels, because for a join rel the set of clauses that are treated as
578  * restrict clauses varies depending on which sub-relations we choose to join.
579  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
580  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
581  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
582  * and should not be processed again at the level of {1 2 3}.) Therefore,
583  * the restrictinfo list in the join case appears in individual JoinPaths
584  * (field joinrestrictinfo), not in the parent relation. But it's OK for
585  * the RelOptInfo to store the joininfo list, because that is the same
586  * for a given rel no matter how we form it.
587  *
588  * We store baserestrictcost in the RelOptInfo (for base relations) because
589  * we know we will need it at least once (to price the sequential scan)
590  * and may need it multiple times to price index scans.
591  *
592  * A join relation is considered to be partitioned if it is formed from a
593  * join of two relations that are partitioned, have matching partitioning
594  * schemes, and are joined on an equijoin of the partitioning columns.
595  * Under those conditions we can consider the join relation to be partitioned
596  * by either relation's partitioning keys, though some care is needed if
597  * either relation can be forced to null by outer-joining. For example, an
598  * outer join like (A LEFT JOIN B ON A.a = B.b) may produce rows with B.b
599  * NULL. These rows may not fit the partitioning conditions imposed on B.
600  * Hence, strictly speaking, the join is not partitioned by B.b and thus
601  * partition keys of an outer join should include partition key expressions
602  * from the non-nullable side only. However, if a subsequent join uses
603  * strict comparison operators (and all commonly-used equijoin operators are
604  * strict), the presence of nulls doesn't cause a problem: such rows couldn't
605  * match anything on the other side and thus they don't create a need to do
606  * any cross-partition sub-joins. Hence we can treat such values as still
607  * partitioning the join output for the purpose of additional partitionwise
608  * joining, so long as a strict join operator is used by the next join.
609  *
610  * If the relation is partitioned, these fields will be set:
611  *
612  * part_scheme - Partitioning scheme of the relation
613  * nparts - Number of partitions
614  * boundinfo - Partition bounds
615  * partbounds_merged - true if partition bounds are merged ones
616  * partition_qual - Partition constraint if not the root
617  * part_rels - RelOptInfos for each partition
618  * all_partrels - Relids set of all partition relids
619  * partexprs, nullable_partexprs - Partition key expressions
620  *
621  * The partexprs and nullable_partexprs arrays each contain
622  * part_scheme->partnatts elements. Each of the elements is a list of
623  * partition key expressions. For partitioned base relations, there is one
624  * expression in each partexprs element, and nullable_partexprs is empty.
625  * For partitioned join relations, each base relation within the join
626  * contributes one partition key expression per partitioning column;
627  * that expression goes in the partexprs[i] list if the base relation
628  * is not nullable by this join or any lower outer join, or in the
629  * nullable_partexprs[i] list if the base relation is nullable.
630  * Furthermore, FULL JOINs add extra nullable_partexprs expressions
631  * corresponding to COALESCE expressions of the left and right join columns,
632  * to simplify matching join clauses to those lists.
633  *----------
634  */
635 
636 /* Bitmask of flags supported by table AMs */
637 #define AMFLAG_HAS_TID_RANGE (1 << 0)
638 
639 typedef enum RelOptKind
640 {
648 } RelOptKind;
649 
650 /*
651  * Is the given relation a simple relation i.e a base or "other" member
652  * relation?
653  */
654 #define IS_SIMPLE_REL(rel) \
655  ((rel)->reloptkind == RELOPT_BASEREL || \
656  (rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
657 
658 /* Is the given relation a join relation? */
659 #define IS_JOIN_REL(rel) \
660  ((rel)->reloptkind == RELOPT_JOINREL || \
661  (rel)->reloptkind == RELOPT_OTHER_JOINREL)
662 
663 /* Is the given relation an upper relation? */
664 #define IS_UPPER_REL(rel) \
665  ((rel)->reloptkind == RELOPT_UPPER_REL || \
666  (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
667 
668 /* Is the given relation an "other" relation? */
669 #define IS_OTHER_REL(rel) \
670  ((rel)->reloptkind == RELOPT_OTHER_MEMBER_REL || \
671  (rel)->reloptkind == RELOPT_OTHER_JOINREL || \
672  (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
673 
674 typedef struct RelOptInfo
675 {
677 
679 
680  /* all relations included in this RelOptInfo */
681  Relids relids; /* set of base relids (rangetable indexes) */
682 
683  /* size estimates generated by planner */
684  Cardinality rows; /* estimated number of result tuples */
685 
686  /* per-relation planner control flags */
687  bool consider_startup; /* keep cheap-startup-cost paths? */
688  bool consider_param_startup; /* ditto, for parameterized paths? */
689  bool consider_parallel; /* consider parallel paths? */
690 
691  /* default result targetlist for Paths scanning this relation */
692  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
693 
694  /* materialization information */
695  List *pathlist; /* Path structures */
696  List *ppilist; /* ParamPathInfos used in pathlist */
697  List *partial_pathlist; /* partial Paths */
702 
703  /* parameterization information needed for both base rels and join rels */
704  /* (see also lateral_vars and lateral_referencers) */
705  Relids direct_lateral_relids; /* rels directly laterally referenced */
706  Relids lateral_relids; /* minimum parameterization of rel */
707 
708  /* information about a base rel (not set for join rels!) */
710  Oid reltablespace; /* containing tablespace */
711  RTEKind rtekind; /* RELATION, SUBQUERY, FUNCTION, etc */
712  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
713  AttrNumber max_attr; /* largest attrno of rel */
714  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
715  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
716  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
717  Relids lateral_referencers; /* rels that reference me laterally */
718  List *indexlist; /* list of IndexOptInfo */
719  List *statlist; /* list of StatisticExtInfo */
720  BlockNumber pages; /* size estimates derived from pg_class */
722  double allvisfrac;
723  Bitmapset *eclass_indexes; /* Indexes in PlannerInfo's eq_classes list of
724  * ECs that mention this rel */
725  PlannerInfo *subroot; /* if subquery */
726  List *subplan_params; /* if subquery */
727  int rel_parallel_workers; /* wanted number of parallel workers */
728  uint32 amflags; /* Bitmask of optional features supported by
729  * the table AM */
730 
731  /* Information about foreign tables and foreign joins */
732  Oid serverid; /* identifies server for the table or join */
733  Oid userid; /* identifies user to check access as */
734  bool useridiscurrent; /* join is only valid for current user */
735  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
737  void *fdw_private;
738 
739  /* cache space for remembering if we have proven this relation unique */
740  List *unique_for_rels; /* known unique for these other relid
741  * set(s) */
742  List *non_unique_for_rels; /* known not unique for these set(s) */
743 
744  /* used by various scans and joins: */
745  List *baserestrictinfo; /* RestrictInfo structures (if base rel) */
746  QualCost baserestrictcost; /* cost of evaluating the above */
747  Index baserestrict_min_security; /* min security_level found in
748  * baserestrictinfo */
749  List *joininfo; /* RestrictInfo structures for join clauses
750  * involving this rel */
751  bool has_eclass_joins; /* T means joininfo is incomplete */
752 
753  /* used by partitionwise joins: */
754  bool consider_partitionwise_join; /* consider partitionwise join
755  * paths? (if partitioned rel) */
756  Relids top_parent_relids; /* Relids of topmost parents (if "other"
757  * rel) */
758 
759  /* used for partitioned relations: */
760  PartitionScheme part_scheme; /* Partitioning scheme */
761  int nparts; /* Number of partitions; -1 if not yet set; in
762  * case of a join relation 0 means it's
763  * considered unpartitioned */
764  struct PartitionBoundInfoData *boundinfo; /* Partition bounds */
765  bool partbounds_merged; /* True if partition bounds were created
766  * by partition_bounds_merge() */
767  List *partition_qual; /* Partition constraint, if not the root */
768  struct RelOptInfo **part_rels; /* Array of RelOptInfos of partitions,
769  * stored in the same order as bounds */
770  Bitmapset *live_parts; /* Bitmap with members acting as indexes into
771  * the part_rels[] array to indicate which
772  * partitions survived partition pruning. */
773  Relids all_partrels; /* Relids set of all partition relids */
774  List **partexprs; /* Non-nullable partition key expressions */
775  List **nullable_partexprs; /* Nullable partition key expressions */
776 } RelOptInfo;
777 
778 /*
779  * Is given relation partitioned?
780  *
781  * It's not enough to test whether rel->part_scheme is set, because it might
782  * be that the basic partitioning properties of the input relations matched
783  * but the partition bounds did not. Also, if we are able to prove a rel
784  * dummy (empty), we should henceforth treat it as unpartitioned.
785  */
786 #define IS_PARTITIONED_REL(rel) \
787  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
788  (rel)->part_rels && !IS_DUMMY_REL(rel))
789 
790 /*
791  * Convenience macro to make sure that a partitioned relation has all the
792  * required members set.
793  */
794 #define REL_HAS_ALL_PART_PROPS(rel) \
795  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
796  (rel)->part_rels && (rel)->partexprs && (rel)->nullable_partexprs)
797 
798 /*
799  * IndexOptInfo
800  * Per-index information for planning/optimization
801  *
802  * indexkeys[], indexcollations[] each have ncolumns entries.
803  * opfamily[], and opcintype[] each have nkeycolumns entries. They do
804  * not contain any information about included attributes.
805  *
806  * sortopfamily[], reverse_sort[], and nulls_first[] have
807  * nkeycolumns entries, if the index is ordered; but if it is unordered,
808  * those pointers are NULL.
809  *
810  * Zeroes in the indexkeys[] array indicate index columns that are
811  * expressions; there is one element in indexprs for each such column.
812  *
813  * For an ordered index, reverse_sort[] and nulls_first[] describe the
814  * sort ordering of a forward indexscan; we can also consider a backward
815  * indexscan, which will generate the reverse ordering.
816  *
817  * The indexprs and indpred expressions have been run through
818  * prepqual.c and eval_const_expressions() for ease of matching to
819  * WHERE clauses. indpred is in implicit-AND form.
820  *
821  * indextlist is a TargetEntry list representing the index columns.
822  * It provides an equivalent base-relation Var for each simple column,
823  * and links to the matching indexprs element for each expression column.
824  *
825  * While most of these fields are filled when the IndexOptInfo is created
826  * (by plancat.c), indrestrictinfo and predOK are set later, in
827  * check_index_predicates().
828  */
829 #ifndef HAVE_INDEXOPTINFO_TYPEDEF
830 typedef struct IndexOptInfo IndexOptInfo;
831 #define HAVE_INDEXOPTINFO_TYPEDEF 1
832 #endif
833 
835 {
837 
838  Oid indexoid; /* OID of the index relation */
839  Oid reltablespace; /* tablespace of index (not table) */
840  RelOptInfo *rel; /* back-link to index's table */
841 
842  /* index-size statistics (from pg_class and elsewhere) */
843  BlockNumber pages; /* number of disk pages in index */
844  Cardinality tuples; /* number of index tuples in index */
845  int tree_height; /* index tree height, or -1 if unknown */
846 
847  /* index descriptor information */
848  int ncolumns; /* number of columns in index */
849  int nkeycolumns; /* number of key columns in index */
850  int *indexkeys; /* column numbers of index's attributes both
851  * key and included columns, or 0 */
852  Oid *indexcollations; /* OIDs of collations of index columns */
853  Oid *opfamily; /* OIDs of operator families for columns */
854  Oid *opcintype; /* OIDs of opclass declared input data types */
855  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
856  bool *reverse_sort; /* is sort order descending? */
857  bool *nulls_first; /* do NULLs come first in the sort order? */
858  bytea **opclassoptions; /* opclass-specific options for columns */
859  bool *canreturn; /* which index cols can be returned in an
860  * index-only scan? */
861  Oid relam; /* OID of the access method (in pg_am) */
862 
863  List *indexprs; /* expressions for non-simple index columns */
864  List *indpred; /* predicate if a partial index, else NIL */
865 
866  List *indextlist; /* targetlist representing index columns */
867 
868  List *indrestrictinfo; /* parent relation's baserestrictinfo
869  * list, less any conditions implied by
870  * the index's predicate (unless it's a
871  * target rel, see comments in
872  * check_index_predicates()) */
873 
874  bool predOK; /* true if index predicate matches query */
875  bool unique; /* true if a unique index */
876  bool immediate; /* is uniqueness enforced immediately? */
877  bool hypothetical; /* true if index doesn't really exist */
878 
879  /* Remaining fields are copied from the index AM's API struct: */
880  bool amcanorderbyop; /* does AM support order by operator result? */
881  bool amoptionalkey; /* can query omit key for the first column? */
882  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
883  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
884  bool amhasgettuple; /* does AM have amgettuple interface? */
885  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
886  bool amcanparallel; /* does AM support parallel scan? */
887  bool amcanmarkpos; /* does AM support mark/restore? */
888  /* Rather than include amapi.h here, we declare amcostestimate like this */
889  void (*amcostestimate) (); /* AM's cost estimator */
890 };
891 
892 /*
893  * ForeignKeyOptInfo
894  * Per-foreign-key information for planning/optimization
895  *
896  * The per-FK-column arrays can be fixed-size because we allow at most
897  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
898  * nkeys valid entries.
899  */
900 typedef struct ForeignKeyOptInfo
901 {
903 
904  /* Basic data about the foreign key (fetched from catalogs): */
905  Index con_relid; /* RT index of the referencing table */
906  Index ref_relid; /* RT index of the referenced table */
907  int nkeys; /* number of columns in the foreign key */
908  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
909  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
910  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
911 
912  /* Derived info about whether FK's equality conditions match the query: */
913  int nmatched_ec; /* # of FK cols matched by ECs */
914  int nconst_ec; /* # of these ECs that are ec_has_const */
915  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
916  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
917  /* Pointer to eclass matching each column's condition, if there is one */
919  /* Pointer to eclass member for the referencing Var, if there is one */
920  struct EquivalenceMember *fk_eclass_member[INDEX_MAX_KEYS];
921  /* List of non-EC RestrictInfos matching each column's condition */
924 
925 /*
926  * StatisticExtInfo
927  * Information about extended statistics for planning/optimization
928  *
929  * Each pg_statistic_ext row is represented by one or more nodes of this
930  * type, or even zero if ANALYZE has not computed them.
931  */
932 typedef struct StatisticExtInfo
933 {
935 
936  Oid statOid; /* OID of the statistics row */
937  RelOptInfo *rel; /* back-link to statistic's table */
938  char kind; /* statistics kind of this entry */
939  Bitmapset *keys; /* attnums of the columns covered */
940  List *exprs; /* expressions */
942 
943 /*
944  * EquivalenceClasses
945  *
946  * Whenever we can determine that a mergejoinable equality clause A = B is
947  * not delayed by any outer join, we create an EquivalenceClass containing
948  * the expressions A and B to record this knowledge. If we later find another
949  * equivalence B = C, we add C to the existing EquivalenceClass; this may
950  * require merging two existing EquivalenceClasses. At the end of the qual
951  * distribution process, we have sets of values that are known all transitively
952  * equal to each other, where "equal" is according to the rules of the btree
953  * operator family(s) shown in ec_opfamilies, as well as the collation shown
954  * by ec_collation. (We restrict an EC to contain only equalities whose
955  * operators belong to the same set of opfamilies. This could probably be
956  * relaxed, but for now it's not worth the trouble, since nearly all equality
957  * operators belong to only one btree opclass anyway. Similarly, we suppose
958  * that all or none of the input datatypes are collatable, so that a single
959  * collation value is sufficient.)
960  *
961  * We also use EquivalenceClasses as the base structure for PathKeys, letting
962  * us represent knowledge about different sort orderings being equivalent.
963  * Since every PathKey must reference an EquivalenceClass, we will end up
964  * with single-member EquivalenceClasses whenever a sort key expression has
965  * not been equivalenced to anything else. It is also possible that such an
966  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
967  * which is a case that can't arise otherwise since clauses containing
968  * volatile functions are never considered mergejoinable. We mark such
969  * EquivalenceClasses specially to prevent them from being merged with
970  * ordinary EquivalenceClasses. Also, for volatile expressions we have
971  * to be careful to match the EquivalenceClass to the correct targetlist
972  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
973  * So we record the SortGroupRef of the originating sort clause.
974  *
975  * We allow equality clauses appearing below the nullable side of an outer join
976  * to form EquivalenceClasses, but these have a slightly different meaning:
977  * the included values might be all NULL rather than all the same non-null
978  * values. See src/backend/optimizer/README for more on that point.
979  *
980  * NB: if ec_merged isn't NULL, this class has been merged into another, and
981  * should be ignored in favor of using the pointed-to class.
982  */
983 typedef struct EquivalenceClass
984 {
986 
987  List *ec_opfamilies; /* btree operator family OIDs */
988  Oid ec_collation; /* collation, if datatypes are collatable */
989  List *ec_members; /* list of EquivalenceMembers */
990  List *ec_sources; /* list of generating RestrictInfos */
991  List *ec_derives; /* list of derived RestrictInfos */
992  Relids ec_relids; /* all relids appearing in ec_members, except
993  * for child members (see below) */
994  bool ec_has_const; /* any pseudoconstants in ec_members? */
995  bool ec_has_volatile; /* the (sole) member is a volatile expr */
996  bool ec_below_outer_join; /* equivalence applies below an OJ */
997  bool ec_broken; /* failed to generate needed clauses? */
998  Index ec_sortref; /* originating sortclause label, or 0 */
999  Index ec_min_security; /* minimum security_level in ec_sources */
1000  Index ec_max_security; /* maximum security_level in ec_sources */
1001  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
1003 
1004 /*
1005  * If an EC contains a const and isn't below-outer-join, any PathKey depending
1006  * on it must be redundant, since there's only one possible value of the key.
1007  */
1008 #define EC_MUST_BE_REDUNDANT(eclass) \
1009  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
1010 
1011 /*
1012  * EquivalenceMember - one member expression of an EquivalenceClass
1013  *
1014  * em_is_child signifies that this element was built by transposing a member
1015  * for an appendrel parent relation to represent the corresponding expression
1016  * for an appendrel child. These members are used for determining the
1017  * pathkeys of scans on the child relation and for explicitly sorting the
1018  * child when necessary to build a MergeAppend path for the whole appendrel
1019  * tree. An em_is_child member has no impact on the properties of the EC as a
1020  * whole; in particular the EC's ec_relids field does NOT include the child
1021  * relation. An em_is_child member should never be marked em_is_const nor
1022  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
1023  * members are not really full-fledged members of the EC, but just reflections
1024  * or doppelgangers of real members. Most operations on EquivalenceClasses
1025  * should ignore em_is_child members, and those that don't should test
1026  * em_relids to make sure they only consider relevant members.
1027  *
1028  * em_datatype is usually the same as exprType(em_expr), but can be
1029  * different when dealing with a binary-compatible opfamily; in particular
1030  * anyarray_ops would never work without this. Use em_datatype when
1031  * looking up a specific btree operator to work with this expression.
1032  */
1033 typedef struct EquivalenceMember
1034 {
1036 
1037  Expr *em_expr; /* the expression represented */
1038  Relids em_relids; /* all relids appearing in em_expr */
1039  Relids em_nullable_relids; /* nullable by lower outer joins */
1040  bool em_is_const; /* expression is pseudoconstant? */
1041  bool em_is_child; /* derived version for a child relation? */
1042  Oid em_datatype; /* the "nominal type" used by the opfamily */
1044 
1045 /*
1046  * PathKeys
1047  *
1048  * The sort ordering of a path is represented by a list of PathKey nodes.
1049  * An empty list implies no known ordering. Otherwise the first item
1050  * represents the primary sort key, the second the first secondary sort key,
1051  * etc. The value being sorted is represented by linking to an
1052  * EquivalenceClass containing that value and including pk_opfamily among its
1053  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
1054  * This is a convenient method because it makes it trivial to detect
1055  * equivalent and closely-related orderings. (See optimizer/README for more
1056  * information.)
1057  *
1058  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
1059  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
1060  * index types will use btree-compatible strategy numbers.
1061  */
1062 typedef struct PathKey
1063 {
1065 
1066  EquivalenceClass *pk_eclass; /* the value that is ordered */
1067  Oid pk_opfamily; /* btree opfamily defining the ordering */
1068  int pk_strategy; /* sort direction (ASC or DESC) */
1069  bool pk_nulls_first; /* do NULLs come before normal values? */
1070 } PathKey;
1071 
1072 /*
1073  * VolatileFunctionStatus -- allows nodes to cache their
1074  * contain_volatile_functions properties. VOLATILITY_UNKNOWN means not yet
1075  * determined.
1076  */
1078 {
1083 
1084 /*
1085  * PathTarget
1086  *
1087  * This struct contains what we need to know during planning about the
1088  * targetlist (output columns) that a Path will compute. Each RelOptInfo
1089  * includes a default PathTarget, which its individual Paths may simply
1090  * reference. However, in some cases a Path may compute outputs different
1091  * from other Paths, and in that case we make a custom PathTarget for it.
1092  * For example, an indexscan might return index expressions that would
1093  * otherwise need to be explicitly calculated. (Note also that "upper"
1094  * relations generally don't have useful default PathTargets.)
1095  *
1096  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
1097  * though those will appear in finished Plans.
1098  *
1099  * sortgrouprefs[] is an array of the same length as exprs, containing the
1100  * corresponding sort/group refnos, or zeroes for expressions not referenced
1101  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
1102  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
1103  * we have not identified sort/group columns in this tlist. This allows us to
1104  * deal with sort/group refnos when needed with less expense than including
1105  * TargetEntry nodes in the exprs list.
1106  */
1107 typedef struct PathTarget
1108 {
1110  List *exprs; /* list of expressions to be computed */
1111  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
1112  QualCost cost; /* cost of evaluating the expressions */
1113  int width; /* estimated avg width of result tuples */
1114  VolatileFunctionStatus has_volatile_expr; /* indicates if exprs contain
1115  * any volatile functions. */
1116 } PathTarget;
1117 
1118 /* Convenience macro to get a sort/group refno from a PathTarget */
1119 #define get_pathtarget_sortgroupref(target, colno) \
1120  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
1121 
1122 
1123 /*
1124  * ParamPathInfo
1125  *
1126  * All parameterized paths for a given relation with given required outer rels
1127  * link to a single ParamPathInfo, which stores common information such as
1128  * the estimated rowcount for this parameterization. We do this partly to
1129  * avoid recalculations, but mostly to ensure that the estimated rowcount
1130  * is in fact the same for every such path.
1131  *
1132  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
1133  * in join cases it's NIL because the set of relevant clauses varies depending
1134  * on how the join is formed. The relevant clauses will appear in each
1135  * parameterized join path's joinrestrictinfo list, instead.
1136  */
1137 typedef struct ParamPathInfo
1138 {
1140 
1141  Relids ppi_req_outer; /* rels supplying parameters used by path */
1142  Cardinality ppi_rows; /* estimated number of result tuples */
1143  List *ppi_clauses; /* join clauses available from outer rels */
1144 } ParamPathInfo;
1145 
1146 
1147 /*
1148  * Type "Path" is used as-is for sequential-scan paths, as well as some other
1149  * simple plan types that we don't need any extra information in the path for.
1150  * For other path types it is the first component of a larger struct.
1151  *
1152  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
1153  * It is partially redundant with the Path's NodeTag, but allows us to use
1154  * the same Path type for multiple Plan types when there is no need to
1155  * distinguish the Plan type during path processing.
1156  *
1157  * "parent" identifies the relation this Path scans, and "pathtarget"
1158  * describes the precise set of output columns the Path would compute.
1159  * In simple cases all Paths for a given rel share the same targetlist,
1160  * which we represent by having path->pathtarget equal to parent->reltarget.
1161  *
1162  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
1163  * relation(s) that provide parameter values to each scan of this path.
1164  * That means this path can only be joined to those rels by means of nestloop
1165  * joins with this path on the inside. Also note that a parameterized path
1166  * is responsible for testing all "movable" joinclauses involving this rel
1167  * and the specified outer rel(s).
1168  *
1169  * "rows" is the same as parent->rows in simple paths, but in parameterized
1170  * paths and UniquePaths it can be less than parent->rows, reflecting the
1171  * fact that we've filtered by extra join conditions or removed duplicates.
1172  *
1173  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
1174  * ordering of the path's output rows.
1175  */
1176 typedef struct Path
1177 {
1179 
1180  NodeTag pathtype; /* tag identifying scan/join method */
1181 
1182  RelOptInfo *parent; /* the relation this path can build */
1183  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
1184 
1185  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
1186 
1187  bool parallel_aware; /* engage parallel-aware logic? */
1188  bool parallel_safe; /* OK to use as part of parallel plan? */
1189  int parallel_workers; /* desired # of workers; 0 = not parallel */
1190 
1191  /* estimated size/costs for path (see costsize.c for more info) */
1192  Cardinality rows; /* estimated number of result tuples */
1193  Cost startup_cost; /* cost expended before fetching any tuples */
1194  Cost total_cost; /* total cost (assuming all tuples fetched) */
1195 
1196  List *pathkeys; /* sort ordering of path's output */
1197  /* pathkeys is a List of PathKey nodes; see above */
1198 } Path;
1199 
1200 /* Macro for extracting a path's parameterization relids; beware double eval */
1201 #define PATH_REQ_OUTER(path) \
1202  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
1203 
1204 /*----------
1205  * IndexPath represents an index scan over a single index.
1206  *
1207  * This struct is used for both regular indexscans and index-only scans;
1208  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
1209  *
1210  * 'indexinfo' is the index to be scanned.
1211  *
1212  * 'indexclauses' is a list of IndexClause nodes, each representing one
1213  * index-checkable restriction, with implicit AND semantics across the list.
1214  * An empty list implies a full index scan.
1215  *
1216  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
1217  * been found to be usable as ordering operators for an amcanorderbyop index.
1218  * The list must match the path's pathkeys, ie, one expression per pathkey
1219  * in the same order. These are not RestrictInfos, just bare expressions,
1220  * since they generally won't yield booleans. It's guaranteed that each
1221  * expression has the index key on the left side of the operator.
1222  *
1223  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
1224  * of the same length as 'indexorderbys', showing which index column each
1225  * ORDER BY expression is meant to be used with. (There is no restriction
1226  * on which index column each ORDER BY can be used with.)
1227  *
1228  * 'indexscandir' is one of:
1229  * ForwardScanDirection: forward scan of an ordered index
1230  * BackwardScanDirection: backward scan of an ordered index
1231  * NoMovementScanDirection: scan of an unordered index, or don't care
1232  * (The executor doesn't care whether it gets ForwardScanDirection or
1233  * NoMovementScanDirection for an indexscan, but the planner wants to
1234  * distinguish ordered from unordered indexes for building pathkeys.)
1235  *
1236  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
1237  * we need not recompute them when considering using the same index in a
1238  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
1239  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
1240  *----------
1241  */
1242 typedef struct IndexPath
1243 {
1252 } IndexPath;
1253 
1254 /*
1255  * Each IndexClause references a RestrictInfo node from the query's WHERE
1256  * or JOIN conditions, and shows how that restriction can be applied to
1257  * the particular index. We support both indexclauses that are directly
1258  * usable by the index machinery, which are typically of the form
1259  * "indexcol OP pseudoconstant", and those from which an indexable qual
1260  * can be derived. The simplest such transformation is that a clause
1261  * of the form "pseudoconstant OP indexcol" can be commuted to produce an
1262  * indexable qual (the index machinery expects the indexcol to be on the
1263  * left always). Another example is that we might be able to extract an
1264  * indexable range condition from a LIKE condition, as in "x LIKE 'foo%bar'"
1265  * giving rise to "x >= 'foo' AND x < 'fop'". Derivation of such lossy
1266  * conditions is done by a planner support function attached to the
1267  * indexclause's top-level function or operator.
1268  *
1269  * indexquals is a list of RestrictInfos for the directly-usable index
1270  * conditions associated with this IndexClause. In the simplest case
1271  * it's a one-element list whose member is iclause->rinfo. Otherwise,
1272  * it contains one or more directly-usable indexqual conditions extracted
1273  * from the given clause. The 'lossy' flag indicates whether the
1274  * indexquals are semantically equivalent to the original clause, or
1275  * represent a weaker condition.
1276  *
1277  * Normally, indexcol is the index of the single index column the clause
1278  * works on, and indexcols is NIL. But if the clause is a RowCompareExpr,
1279  * indexcol is the index of the leading column, and indexcols is a list of
1280  * all the affected columns. (Note that indexcols matches up with the
1281  * columns of the actual indexable RowCompareExpr in indexquals, which
1282  * might be different from the original in rinfo.)
1283  *
1284  * An IndexPath's IndexClause list is required to be ordered by index
1285  * column, i.e. the indexcol values must form a nondecreasing sequence.
1286  * (The order of multiple clauses for the same index column is unspecified.)
1287  */
1288 typedef struct IndexClause
1289 {
1291  struct RestrictInfo *rinfo; /* original restriction or join clause */
1292  List *indexquals; /* indexqual(s) derived from it */
1293  bool lossy; /* are indexquals a lossy version of clause? */
1294  AttrNumber indexcol; /* index column the clause uses (zero-based) */
1295  List *indexcols; /* multiple index columns, if RowCompare */
1296 } IndexClause;
1297 
1298 /*
1299  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
1300  * instead of directly accessing the heap, followed by AND/OR combinations
1301  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
1302  * Note that the output is always considered unordered, since it will come
1303  * out in physical heap order no matter what the underlying indexes did.
1304  *
1305  * The individual indexscans are represented by IndexPath nodes, and any
1306  * logic on top of them is represented by a tree of BitmapAndPath and
1307  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
1308  * to represent a regular (or index-only) index scan plan, and as the child
1309  * of a BitmapHeapPath that represents scanning the same index using a
1310  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
1311  * always represent the costs to use it as a regular (or index-only)
1312  * IndexScan. The costs of a BitmapIndexScan can be computed using the
1313  * IndexPath's indextotalcost and indexselectivity.
1314  */
1315 typedef struct BitmapHeapPath
1316 {
1318  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1319 } BitmapHeapPath;
1320 
1321 /*
1322  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1323  * part of the substructure of a BitmapHeapPath. The Path structure is
1324  * a bit more heavyweight than we really need for this, but for simplicity
1325  * we make it a derivative of Path anyway.
1326  */
1327 typedef struct BitmapAndPath
1328 {
1330  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1332 } BitmapAndPath;
1333 
1334 /*
1335  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1336  * part of the substructure of a BitmapHeapPath. The Path structure is
1337  * a bit more heavyweight than we really need for this, but for simplicity
1338  * we make it a derivative of Path anyway.
1339  */
1340 typedef struct BitmapOrPath
1341 {
1343  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1345 } BitmapOrPath;
1346 
1347 /*
1348  * TidPath represents a scan by TID
1349  *
1350  * tidquals is an implicitly OR'ed list of qual expressions of the form
1351  * "CTID = pseudoconstant", or "CTID = ANY(pseudoconstant_array)",
1352  * or a CurrentOfExpr for the relation.
1353  */
1354 typedef struct TidPath
1355 {
1357  List *tidquals; /* qual(s) involving CTID = something */
1358 } TidPath;
1359 
1360 /*
1361  * TidRangePath represents a scan by a contiguous range of TIDs
1362  *
1363  * tidrangequals is an implicitly AND'ed list of qual expressions of the form
1364  * "CTID relop pseudoconstant", where relop is one of >,>=,<,<=.
1365  */
1366 typedef struct TidRangePath
1367 {
1370 } TidRangePath;
1371 
1372 /*
1373  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1374  *
1375  * Note that the subpath comes from a different planning domain; for example
1376  * RTE indexes within it mean something different from those known to the
1377  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1378  * interpret the subpath.
1379  */
1380 typedef struct SubqueryScanPath
1381 {
1383  Path *subpath; /* path representing subquery execution */
1385 
1386 /*
1387  * ForeignPath represents a potential scan of a foreign table, foreign join
1388  * or foreign upper-relation.
1389  *
1390  * fdw_private stores FDW private data about the scan. While fdw_private is
1391  * not actually touched by the core code during normal operations, it's
1392  * generally a good idea to use a representation that can be dumped by
1393  * nodeToString(), so that you can examine the structure during debugging
1394  * with tools like pprint().
1395  */
1396 typedef struct ForeignPath
1397 {
1401 } ForeignPath;
1402 
1403 /*
1404  * CustomPath represents a table scan done by some out-of-core extension.
1405  *
1406  * We provide a set of hooks here - which the provider must take care to set
1407  * up correctly - to allow extensions to supply their own methods of scanning
1408  * a relation. For example, a provider might provide GPU acceleration, a
1409  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1410  *
1411  * CustomPaths can be injected into the planning process for a relation by
1412  * set_rel_pathlist_hook functions.
1413  *
1414  * Core code must avoid assuming that the CustomPath is only as large as
1415  * the structure declared here; providers are allowed to make it the first
1416  * element in a larger structure. (Since the planner never copies Paths,
1417  * this doesn't add any complication.) However, for consistency with the
1418  * FDW case, we provide a "custom_private" field in CustomPath; providers
1419  * may prefer to use that rather than define another struct type.
1420  */
1421 
1422 struct CustomPathMethods;
1423 
1424 typedef struct CustomPath
1425 {
1427  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1428  * nodes/extensible.h */
1429  List *custom_paths; /* list of child Path nodes, if any */
1432 } CustomPath;
1433 
1434 /*
1435  * AppendPath represents an Append plan, ie, successive execution of
1436  * several member plans.
1437  *
1438  * For partial Append, 'subpaths' contains non-partial subpaths followed by
1439  * partial subpaths.
1440  *
1441  * Note: it is possible for "subpaths" to contain only one, or even no,
1442  * elements. These cases are optimized during create_append_plan.
1443  * In particular, an AppendPath with no subpaths is a "dummy" path that
1444  * is created to represent the case that a relation is provably empty.
1445  * (This is a convenient representation because it means that when we build
1446  * an appendrel and find that all its children have been excluded, no extra
1447  * action is needed to recognize the relation as dummy.)
1448  */
1449 typedef struct AppendPath
1450 {
1452  List *subpaths; /* list of component Paths */
1453  /* Index of first partial path in subpaths; list_length(subpaths) if none */
1455  Cardinality limit_tuples; /* hard limit on output tuples, or -1 */
1456 } AppendPath;
1457 
1458 #define IS_DUMMY_APPEND(p) \
1459  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1460 
1461 /*
1462  * A relation that's been proven empty will have one path that is dummy
1463  * (but might have projection paths on top). For historical reasons,
1464  * this is provided as a macro that wraps is_dummy_rel().
1465  */
1466 #define IS_DUMMY_REL(r) is_dummy_rel(r)
1467 extern bool is_dummy_rel(RelOptInfo *rel);
1468 
1469 /*
1470  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1471  * results from several member plans to produce similarly-sorted output.
1472  */
1473 typedef struct MergeAppendPath
1474 {
1476  List *subpaths; /* list of component Paths */
1477  Cardinality limit_tuples; /* hard limit on output tuples, or -1 */
1478 } MergeAppendPath;
1479 
1480 /*
1481  * GroupResultPath represents use of a Result plan node to compute the
1482  * output of a degenerate GROUP BY case, wherein we know we should produce
1483  * exactly one row, which might then be filtered by a HAVING qual.
1484  *
1485  * Note that quals is a list of bare clauses, not RestrictInfos.
1486  */
1487 typedef struct GroupResultPath
1488 {
1491 } GroupResultPath;
1492 
1493 /*
1494  * MaterialPath represents use of a Material plan node, i.e., caching of
1495  * the output of its subpath. This is used when the subpath is expensive
1496  * and needs to be scanned repeatedly, or when we need mark/restore ability
1497  * and the subpath doesn't have it.
1498  */
1499 typedef struct MaterialPath
1500 {
1503 } MaterialPath;
1504 
1505 /*
1506  * MemoizePath represents a Memoize plan node, i.e., a cache that caches
1507  * tuples from parameterized paths to save the underlying node from having to
1508  * be rescanned for parameter values which are already cached.
1509  */
1510 typedef struct MemoizePath
1511 {
1513  Path *subpath; /* outerpath to cache tuples from */
1514  List *hash_operators; /* hash operators for each key */
1515  List *param_exprs; /* cache keys */
1516  bool singlerow; /* true if the cache entry is to be marked as
1517  * complete after caching the first record. */
1518  Cardinality calls; /* expected number of rescans */
1519  uint32 est_entries; /* The maximum number of entries that the
1520  * planner expects will fit in the cache, or 0
1521  * if unknown */
1522 } MemoizePath;
1523 
1524 /*
1525  * UniquePath represents elimination of distinct rows from the output of
1526  * its subpath.
1527  *
1528  * This can represent significantly different plans: either hash-based or
1529  * sort-based implementation, or a no-op if the input path can be proven
1530  * distinct already. The decision is sufficiently localized that it's not
1531  * worth having separate Path node types. (Note: in the no-op case, we could
1532  * eliminate the UniquePath node entirely and just return the subpath; but
1533  * it's convenient to have a UniquePath in the path tree to signal upper-level
1534  * routines that the input is known distinct.)
1535  */
1536 typedef enum UniquePathMethod
1537 {
1538  UNIQUE_PATH_NOOP, /* input is known unique already */
1539  UNIQUE_PATH_HASH, /* use hashing */
1540  UNIQUE_PATH_SORT /* use sorting */
1542 
1543 typedef struct UniquePath
1544 {
1548  List *in_operators; /* equality operators of the IN clause */
1549  List *uniq_exprs; /* expressions to be made unique */
1550 } UniquePath;
1551 
1552 /*
1553  * GatherPath runs several copies of a plan in parallel and collects the
1554  * results. The parallel leader may also execute the plan, unless the
1555  * single_copy flag is set.
1556  */
1557 typedef struct GatherPath
1558 {
1560  Path *subpath; /* path for each worker */
1561  bool single_copy; /* don't execute path more than once */
1562  int num_workers; /* number of workers sought to help */
1563 } GatherPath;
1564 
1565 /*
1566  * GatherMergePath runs several copies of a plan in parallel and collects
1567  * the results, preserving their common sort order.
1568  */
1569 typedef struct GatherMergePath
1570 {
1572  Path *subpath; /* path for each worker */
1573  int num_workers; /* number of workers sought to help */
1574 } GatherMergePath;
1575 
1576 
1577 /*
1578  * All join-type paths share these fields.
1579  */
1580 
1581 typedef struct JoinPath
1582 {
1584 
1586 
1587  bool inner_unique; /* each outer tuple provably matches no more
1588  * than one inner tuple */
1589 
1590  Path *outerjoinpath; /* path for the outer side of the join */
1591  Path *innerjoinpath; /* path for the inner side of the join */
1592 
1593  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1594 
1595  /*
1596  * See the notes for RelOptInfo and ParamPathInfo to understand why
1597  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1598  * parent RelOptInfo.
1599  */
1600 } JoinPath;
1601 
1602 /*
1603  * A nested-loop path needs no special fields.
1604  */
1605 
1606 typedef struct NestPath
1607 {
1609 } NestPath;
1610 
1611 /*
1612  * A mergejoin path has these fields.
1613  *
1614  * Unlike other path types, a MergePath node doesn't represent just a single
1615  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1616  * node itself, there can be a Sort node for the outer input, a Sort node
1617  * for the inner input, and/or a Material node for the inner input. We could
1618  * represent these nodes by separate path nodes, but considering how many
1619  * different merge paths are investigated during a complex join problem,
1620  * it seems better to avoid unnecessary palloc overhead.
1621  *
1622  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1623  * that will be used in the merge.
1624  *
1625  * Note that the mergeclauses are a subset of the parent relation's
1626  * restriction-clause list. Any join clauses that are not mergejoinable
1627  * appear only in the parent's restrict list, and must be checked by a
1628  * qpqual at execution time.
1629  *
1630  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1631  * (resp. inner path) is already ordered appropriately for the
1632  * mergejoin. If it is not NIL then it is a PathKeys list describing
1633  * the ordering that must be created by an explicit Sort node.
1634  *
1635  * skip_mark_restore is true if the executor need not do mark/restore calls.
1636  * Mark/restore overhead is usually required, but can be skipped if we know
1637  * that the executor need find only one match per outer tuple, and that the
1638  * mergeclauses are sufficient to identify a match. In such cases the
1639  * executor can immediately advance the outer relation after processing a
1640  * match, and therefore it need never back up the inner relation.
1641  *
1642  * materialize_inner is true if a Material node should be placed atop the
1643  * inner input. This may appear with or without an inner Sort step.
1644  */
1645 
1646 typedef struct MergePath
1647 {
1649  List *path_mergeclauses; /* join clauses to be used for merge */
1650  List *outersortkeys; /* keys for explicit sort, if any */
1651  List *innersortkeys; /* keys for explicit sort, if any */
1652  bool skip_mark_restore; /* can executor skip mark/restore? */
1653  bool materialize_inner; /* add Materialize to inner? */
1654 } MergePath;
1655 
1656 /*
1657  * A hashjoin path has these fields.
1658  *
1659  * The remarks above for mergeclauses apply for hashclauses as well.
1660  *
1661  * Hashjoin does not care what order its inputs appear in, so we have
1662  * no need for sortkeys.
1663  */
1664 
1665 typedef struct HashPath
1666 {
1668  List *path_hashclauses; /* join clauses used for hashing */
1669  int num_batches; /* number of batches expected */
1670  Cardinality inner_rows_total; /* total inner rows expected */
1671 } HashPath;
1672 
1673 /*
1674  * ProjectionPath represents a projection (that is, targetlist computation)
1675  *
1676  * Nominally, this path node represents using a Result plan node to do a
1677  * projection step. However, if the input plan node supports projection,
1678  * we can just modify its output targetlist to do the required calculations
1679  * directly, and not need a Result. In some places in the planner we can just
1680  * jam the desired PathTarget into the input path node (and adjust its cost
1681  * accordingly), so we don't need a ProjectionPath. But in other places
1682  * it's necessary to not modify the input path node, so we need a separate
1683  * ProjectionPath node, which is marked dummy to indicate that we intend to
1684  * assign the work to the input plan node. The estimated cost for the
1685  * ProjectionPath node will account for whether a Result will be used or not.
1686  */
1687 typedef struct ProjectionPath
1688 {
1690  Path *subpath; /* path representing input source */
1691  bool dummypp; /* true if no separate Result is needed */
1692 } ProjectionPath;
1693 
1694 /*
1695  * ProjectSetPath represents evaluation of a targetlist that includes
1696  * set-returning function(s), which will need to be implemented by a
1697  * ProjectSet plan node.
1698  */
1699 typedef struct ProjectSetPath
1700 {
1702  Path *subpath; /* path representing input source */
1703 } ProjectSetPath;
1704 
1705 /*
1706  * SortPath represents an explicit sort step
1707  *
1708  * The sort keys are, by definition, the same as path.pathkeys.
1709  *
1710  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1711  * same as the input's pathtarget.
1712  */
1713 typedef struct SortPath
1714 {
1716  Path *subpath; /* path representing input source */
1717 } SortPath;
1718 
1719 /*
1720  * IncrementalSortPath represents an incremental sort step
1721  *
1722  * This is like a regular sort, except some leading key columns are assumed
1723  * to be ordered already.
1724  */
1725 typedef struct IncrementalSortPath
1726 {
1728  int nPresortedCols; /* number of presorted columns */
1730 
1731 /*
1732  * GroupPath represents grouping (of presorted input)
1733  *
1734  * groupClause represents the columns to be grouped on; the input path
1735  * must be at least that well sorted.
1736  *
1737  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1738  */
1739 typedef struct GroupPath
1740 {
1742  Path *subpath; /* path representing input source */
1743  List *groupClause; /* a list of SortGroupClause's */
1744  List *qual; /* quals (HAVING quals), if any */
1745 } GroupPath;
1746 
1747 /*
1748  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1749  *
1750  * The columns to be compared are the first numkeys columns of the path's
1751  * pathkeys. The input is presumed already sorted that way.
1752  */
1753 typedef struct UpperUniquePath
1754 {
1756  Path *subpath; /* path representing input source */
1757  int numkeys; /* number of pathkey columns to compare */
1758 } UpperUniquePath;
1759 
1760 /*
1761  * AggPath represents generic computation of aggregate functions
1762  *
1763  * This may involve plain grouping (but not grouping sets), using either
1764  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1765  * appropriately presorted.
1766  */
1767 typedef struct AggPath
1768 {
1770  Path *subpath; /* path representing input source */
1771  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1772  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1773  Cardinality numGroups; /* estimated number of groups in input */
1774  uint64 transitionSpace; /* for pass-by-ref transition data */
1775  List *groupClause; /* a list of SortGroupClause's */
1776  List *qual; /* quals (HAVING quals), if any */
1777 } AggPath;
1778 
1779 /*
1780  * Various annotations used for grouping sets in the planner.
1781  */
1782 
1783 typedef struct GroupingSetData
1784 {
1786  List *set; /* grouping set as list of sortgrouprefs */
1787  Cardinality numGroups; /* est. number of result groups */
1788 } GroupingSetData;
1789 
1790 typedef struct RollupData
1791 {
1793  List *groupClause; /* applicable subset of parse->groupClause */
1794  List *gsets; /* lists of integer indexes into groupClause */
1795  List *gsets_data; /* list of GroupingSetData */
1796  Cardinality numGroups; /* est. number of result groups */
1797  bool hashable; /* can be hashed */
1798  bool is_hashed; /* to be implemented as a hashagg */
1799 } RollupData;
1800 
1801 /*
1802  * GroupingSetsPath represents a GROUPING SETS aggregation
1803  */
1804 
1805 typedef struct GroupingSetsPath
1806 {
1808  Path *subpath; /* path representing input source */
1809  AggStrategy aggstrategy; /* basic strategy */
1810  List *rollups; /* list of RollupData */
1811  List *qual; /* quals (HAVING quals), if any */
1812  uint64 transitionSpace; /* for pass-by-ref transition data */
1814 
1815 /*
1816  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1817  */
1818 typedef struct MinMaxAggPath
1819 {
1821  List *mmaggregates; /* list of MinMaxAggInfo */
1822  List *quals; /* HAVING quals, if any */
1823 } MinMaxAggPath;
1824 
1825 /*
1826  * WindowAggPath represents generic computation of window functions
1827  */
1828 typedef struct WindowAggPath
1829 {
1831  Path *subpath; /* path representing input source */
1832  WindowClause *winclause; /* WindowClause we'll be using */
1833 } WindowAggPath;
1834 
1835 /*
1836  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1837  */
1838 typedef struct SetOpPath
1839 {
1841  Path *subpath; /* path representing input source */
1842  SetOpCmd cmd; /* what to do, see nodes.h */
1843  SetOpStrategy strategy; /* how to do it, see nodes.h */
1844  List *distinctList; /* SortGroupClauses identifying target cols */
1845  AttrNumber flagColIdx; /* where is the flag column, if any */
1846  int firstFlag; /* flag value for first input relation */
1847  Cardinality numGroups; /* estimated number of groups in input */
1848 } SetOpPath;
1849 
1850 /*
1851  * RecursiveUnionPath represents a recursive UNION node
1852  */
1853 typedef struct RecursiveUnionPath
1854 {
1856  Path *leftpath; /* paths representing input sources */
1858  List *distinctList; /* SortGroupClauses identifying target cols */
1859  int wtParam; /* ID of Param representing work table */
1860  Cardinality numGroups; /* estimated number of groups in input */
1862 
1863 /*
1864  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1865  */
1866 typedef struct LockRowsPath
1867 {
1869  Path *subpath; /* path representing input source */
1870  List *rowMarks; /* a list of PlanRowMark's */
1871  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1872 } LockRowsPath;
1873 
1874 /*
1875  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1876  *
1877  * We represent most things that will be in the ModifyTable plan node
1878  * literally, except we have a child Path not Plan. But analysis of the
1879  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1880  */
1881 typedef struct ModifyTablePath
1882 {
1884  Path *subpath; /* Path producing source data */
1885  CmdType operation; /* INSERT, UPDATE, or DELETE */
1886  bool canSetTag; /* do we set the command tag/es_processed? */
1887  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1888  Index rootRelation; /* Root RT index, if target is partitioned */
1889  bool partColsUpdated; /* some part key in hierarchy updated? */
1890  List *resultRelations; /* integer list of RT indexes */
1891  List *updateColnosLists; /* per-target-table update_colnos lists */
1892  List *withCheckOptionLists; /* per-target-table WCO lists */
1893  List *returningLists; /* per-target-table RETURNING tlists */
1894  List *rowMarks; /* PlanRowMarks (non-locking only) */
1895  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1896  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1897 } ModifyTablePath;
1898 
1899 /*
1900  * LimitPath represents applying LIMIT/OFFSET restrictions
1901  */
1902 typedef struct LimitPath
1903 {
1905  Path *subpath; /* path representing input source */
1906  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1907  Node *limitCount; /* COUNT parameter, or NULL if none */
1908  LimitOption limitOption; /* FETCH FIRST with ties or exact number */
1909 } LimitPath;
1910 
1911 
1912 /*
1913  * Restriction clause info.
1914  *
1915  * We create one of these for each AND sub-clause of a restriction condition
1916  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1917  * ANDed, we can use any one of them or any subset of them to filter out
1918  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1919  * stores data used by the optimizer while choosing the best query plan.
1920  *
1921  * If a restriction clause references a single base relation, it will appear
1922  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1923  *
1924  * If a restriction clause references more than one base rel, it will
1925  * appear in the joininfo list of every RelOptInfo that describes a strict
1926  * subset of the base rels mentioned in the clause. The joininfo lists are
1927  * used to drive join tree building by selecting plausible join candidates.
1928  * The clause cannot actually be applied until we have built a join rel
1929  * containing all the base rels it references, however.
1930  *
1931  * When we construct a join rel that includes all the base rels referenced
1932  * in a multi-relation restriction clause, we place that clause into the
1933  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1934  * right sub-path includes all base rels referenced in the clause. The clause
1935  * will be applied at that join level, and will not propagate any further up
1936  * the join tree. (Note: the "predicate migration" code was once intended to
1937  * push restriction clauses up and down the plan tree based on evaluation
1938  * costs, but it's dead code and is unlikely to be resurrected in the
1939  * foreseeable future.)
1940  *
1941  * Note that in the presence of more than two rels, a multi-rel restriction
1942  * might reach different heights in the join tree depending on the join
1943  * sequence we use. So, these clauses cannot be associated directly with
1944  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1945  *
1946  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1947  * equalities that are not outerjoin-delayed) are handled a bit differently.
1948  * Initially we attach them to the EquivalenceClasses that are derived from
1949  * them. When we construct a scan or join path, we look through all the
1950  * EquivalenceClasses and generate derived RestrictInfos representing the
1951  * minimal set of conditions that need to be checked for this particular scan
1952  * or join to enforce that all members of each EquivalenceClass are in fact
1953  * equal in all rows emitted by the scan or join.
1954  *
1955  * When dealing with outer joins we have to be very careful about pushing qual
1956  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1957  * be evaluated exactly at that join node, unless they are "degenerate"
1958  * conditions that reference only Vars from the nullable side of the join.
1959  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1960  * down below the outer join, if they reference any nullable Vars.
1961  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1962  * pushed down to a lower level than its original syntactic placement in the
1963  * join tree would suggest. If an outer join prevents us from pushing a qual
1964  * down to its "natural" semantic level (the level associated with just the
1965  * base rels used in the qual) then we mark the qual with a "required_relids"
1966  * value including more than just the base rels it actually uses. By
1967  * pretending that the qual references all the rels required to form the outer
1968  * join, we prevent it from being evaluated below the outer join's joinrel.
1969  * When we do form the outer join's joinrel, we still need to distinguish
1970  * those quals that are actually in that join's JOIN/ON condition from those
1971  * that appeared elsewhere in the tree and were pushed down to the join rel
1972  * because they used no other rels. That's what the is_pushed_down flag is
1973  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1974  * rels listed in required_relids. A clause that originally came from WHERE
1975  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1976  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1977  * if we decide that it can be pushed down into the nullable side of the join.
1978  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1979  * (In short, is_pushed_down is only false for non-degenerate outer join
1980  * conditions. Possibly we should rename it to reflect that meaning? But
1981  * see also the comments for RINFO_IS_PUSHED_DOWN, below.)
1982  *
1983  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1984  * if the clause's applicability must be delayed due to any outer joins
1985  * appearing below it (ie, it has to be postponed to some join level higher
1986  * than the set of relations it actually references).
1987  *
1988  * There is also an outer_relids field, which is NULL except for outer join
1989  * clauses; for those, it is the set of relids on the outer side of the
1990  * clause's outer join. (These are rels that the clause cannot be applied to
1991  * in parameterized scans, since pushing it into the join's outer side would
1992  * lead to wrong answers.)
1993  *
1994  * There is also a nullable_relids field, which is the set of rels the clause
1995  * references that can be forced null by some outer join below the clause.
1996  *
1997  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1998  * a clause might reference some nullable rels and yet not be
1999  * outerjoin_delayed because it also references all the other rels of the
2000  * outer join(s). A clause that is not outerjoin_delayed can be enforced
2001  * anywhere it is computable.
2002  *
2003  * To handle security-barrier conditions efficiently, we mark RestrictInfo
2004  * nodes with a security_level field, in which higher values identify clauses
2005  * coming from less-trusted sources. The exact semantics are that a clause
2006  * cannot be evaluated before another clause with a lower security_level value
2007  * unless the first clause is leakproof. As with outer-join clauses, this
2008  * creates a reason for clauses to sometimes need to be evaluated higher in
2009  * the join tree than their contents would suggest; and even at a single plan
2010  * node, this rule constrains the order of application of clauses.
2011  *
2012  * In general, the referenced clause might be arbitrarily complex. The
2013  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
2014  * or hashjoin clauses are limited (e.g., no volatile functions). The code
2015  * for each kind of path is responsible for identifying the restrict clauses
2016  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
2017  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
2018  * of the finished Plan node, where they will be enforced by general-purpose
2019  * qual-expression-evaluation code. (But we are still entitled to count
2020  * their selectivity when estimating the result tuple count, if we
2021  * can guess what it is...)
2022  *
2023  * When the referenced clause is an OR clause, we generate a modified copy
2024  * in which additional RestrictInfo nodes are inserted below the top-level
2025  * OR/AND structure. This is a convenience for OR indexscan processing:
2026  * indexquals taken from either the top level or an OR subclause will have
2027  * associated RestrictInfo nodes.
2028  *
2029  * The can_join flag is set true if the clause looks potentially useful as
2030  * a merge or hash join clause, that is if it is a binary opclause with
2031  * nonoverlapping sets of relids referenced in the left and right sides.
2032  * (Whether the operator is actually merge or hash joinable isn't checked,
2033  * however.)
2034  *
2035  * The pseudoconstant flag is set true if the clause contains no Vars of
2036  * the current query level and no volatile functions. Such a clause can be
2037  * pulled out and used as a one-time qual in a gating Result node. We keep
2038  * pseudoconstant clauses in the same lists as other RestrictInfos so that
2039  * the regular clause-pushing machinery can assign them to the correct join
2040  * level, but they need to be treated specially for cost and selectivity
2041  * estimates. Note that a pseudoconstant clause can never be an indexqual
2042  * or merge or hash join clause, so it's of no interest to large parts of
2043  * the planner.
2044  *
2045  * When join clauses are generated from EquivalenceClasses, there may be
2046  * several equally valid ways to enforce join equivalence, of which we need
2047  * apply only one. We mark clauses of this kind by setting parent_ec to
2048  * point to the generating EquivalenceClass. Multiple clauses with the same
2049  * parent_ec in the same join are redundant.
2050  */
2051 
2052 typedef struct RestrictInfo
2053 {
2055 
2056  Expr *clause; /* the represented clause of WHERE or JOIN */
2057 
2058  bool is_pushed_down; /* true if clause was pushed down in level */
2059 
2060  bool outerjoin_delayed; /* true if delayed by lower outer join */
2061 
2062  bool can_join; /* see comment above */
2063 
2064  bool pseudoconstant; /* see comment above */
2065 
2066  bool leakproof; /* true if known to contain no leaked Vars */
2067 
2068  VolatileFunctionStatus has_volatile; /* to indicate if clause contains
2069  * any volatile functions. */
2070 
2071  Index security_level; /* see comment above */
2072 
2073  /* The set of relids (varnos) actually referenced in the clause: */
2075 
2076  /* The set of relids required to evaluate the clause: */
2078 
2079  /* If an outer-join clause, the outer-side relations, else NULL: */
2081 
2082  /* The relids used in the clause that are nullable by lower outer joins: */
2084 
2085  /* These fields are set for any binary opclause: */
2086  Relids left_relids; /* relids in left side of clause */
2087  Relids right_relids; /* relids in right side of clause */
2088 
2089  /* This field is NULL unless clause is an OR clause: */
2090  Expr *orclause; /* modified clause with RestrictInfos */
2091 
2092  /* This field is NULL unless clause is potentially redundant: */
2093  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
2094 
2095  /* cache space for cost and selectivity */
2096  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
2097  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
2098  * semantics; -1 if not yet set; >1 means a
2099  * redundant clause */
2100  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
2101  * not yet set */
2102 
2103  /* valid if clause is mergejoinable, else NIL */
2104  List *mergeopfamilies; /* opfamilies containing clause operator */
2105 
2106  /* cache space for mergeclause processing; NULL if not yet set */
2107  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
2108  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
2109  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
2110  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
2111  List *scansel_cache; /* list of MergeScanSelCache structs */
2112 
2113  /* transient workspace for use while considering a specific join path */
2114  bool outer_is_left; /* T = outer var on left, F = on right */
2115 
2116  /* valid if clause is hashjoinable, else InvalidOid: */
2117  Oid hashjoinoperator; /* copy of clause operator */
2118 
2119  /* cache space for hashclause processing; -1 if not yet set */
2120  Selectivity left_bucketsize; /* avg bucketsize of left side */
2121  Selectivity right_bucketsize; /* avg bucketsize of right side */
2122  Selectivity left_mcvfreq; /* left side's most common val's freq */
2123  Selectivity right_mcvfreq; /* right side's most common val's freq */
2124 
2125  /* hash equality operator used for memoize nodes, else InvalidOid */
2127 } RestrictInfo;
2128 
2129 /*
2130  * This macro embodies the correct way to test whether a RestrictInfo is
2131  * "pushed down" to a given outer join, that is, should be treated as a filter
2132  * clause rather than a join clause at that outer join. This is certainly so
2133  * if is_pushed_down is true; but examining that is not sufficient anymore,
2134  * because outer-join clauses will get pushed down to lower outer joins when
2135  * we generate a path for the lower outer join that is parameterized by the
2136  * LHS of the upper one. We can detect such a clause by noting that its
2137  * required_relids exceed the scope of the join.
2138  */
2139 #define RINFO_IS_PUSHED_DOWN(rinfo, joinrelids) \
2140  ((rinfo)->is_pushed_down || \
2141  !bms_is_subset((rinfo)->required_relids, joinrelids))
2142 
2143 /*
2144  * Since mergejoinscansel() is a relatively expensive function, and would
2145  * otherwise be invoked many times while planning a large join tree,
2146  * we go out of our way to cache its results. Each mergejoinable
2147  * RestrictInfo carries a list of the specific sort orderings that have
2148  * been considered for use with it, and the resulting selectivities.
2149  */
2150 typedef struct MergeScanSelCache
2151 {
2152  /* Ordering details (cache lookup key) */
2153  Oid opfamily; /* btree opfamily defining the ordering */
2154  Oid collation; /* collation for the ordering */
2155  int strategy; /* sort direction (ASC or DESC) */
2156  bool nulls_first; /* do NULLs come before normal values? */
2157  /* Results */
2158  Selectivity leftstartsel; /* first-join fraction for clause left side */
2159  Selectivity leftendsel; /* last-join fraction for clause left side */
2160  Selectivity rightstartsel; /* first-join fraction for clause right side */
2161  Selectivity rightendsel; /* last-join fraction for clause right side */
2163 
2164 /*
2165  * Placeholder node for an expression to be evaluated below the top level
2166  * of a plan tree. This is used during planning to represent the contained
2167  * expression. At the end of the planning process it is replaced by either
2168  * the contained expression or a Var referring to a lower-level evaluation of
2169  * the contained expression. Typically the evaluation occurs below an outer
2170  * join, and Var references above the outer join might thereby yield NULL
2171  * instead of the expression value.
2172  *
2173  * Although the planner treats this as an expression node type, it is not
2174  * recognized by the parser or executor, so we declare it here rather than
2175  * in primnodes.h.
2176  */
2177 
2178 typedef struct PlaceHolderVar
2179 {
2181  Expr *phexpr; /* the represented expression */
2182  Relids phrels; /* base relids syntactically within expr src */
2183  Index phid; /* ID for PHV (unique within planner run) */
2184  Index phlevelsup; /* > 0 if PHV belongs to outer query */
2185 } PlaceHolderVar;
2186 
2187 /*
2188  * "Special join" info.
2189  *
2190  * One-sided outer joins constrain the order of joining partially but not
2191  * completely. We flatten such joins into the planner's top-level list of
2192  * relations to join, but record information about each outer join in a
2193  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
2194  * join_info_list.
2195  *
2196  * Similarly, semijoins and antijoins created by flattening IN (subselect)
2197  * and EXISTS(subselect) clauses create partial constraints on join order.
2198  * These are likewise recorded in SpecialJoinInfo structs.
2199  *
2200  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
2201  * of planning for them, because this simplifies make_join_rel()'s API.
2202  *
2203  * min_lefthand and min_righthand are the sets of base relids that must be
2204  * available on each side when performing the special join. lhs_strict is
2205  * true if the special join's condition cannot succeed when the LHS variables
2206  * are all NULL (this means that an outer join can commute with upper-level
2207  * outer joins even if it appears in their RHS). We don't bother to set
2208  * lhs_strict for FULL JOINs, however.
2209  *
2210  * It is not valid for either min_lefthand or min_righthand to be empty sets;
2211  * if they were, this would break the logic that enforces join order.
2212  *
2213  * syn_lefthand and syn_righthand are the sets of base relids that are
2214  * syntactically below this special join. (These are needed to help compute
2215  * min_lefthand and min_righthand for higher joins.)
2216  *
2217  * delay_upper_joins is set true if we detect a pushed-down clause that has
2218  * to be evaluated after this join is formed (because it references the RHS).
2219  * Any outer joins that have such a clause and this join in their RHS cannot
2220  * commute with this join, because that would leave noplace to check the
2221  * pushed-down clause. (We don't track this for FULL JOINs, either.)
2222  *
2223  * For a semijoin, we also extract the join operators and their RHS arguments
2224  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
2225  * This is done in support of possibly unique-ifying the RHS, so we don't
2226  * bother unless at least one of semi_can_btree and semi_can_hash can be set
2227  * true. (You might expect that this information would be computed during
2228  * join planning; but it's helpful to have it available during planning of
2229  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
2230  *
2231  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
2232  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
2233  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
2234  *
2235  * For purposes of join selectivity estimation, we create transient
2236  * SpecialJoinInfo structures for regular inner joins; so it is possible
2237  * to have jointype == JOIN_INNER in such a structure, even though this is
2238  * not allowed within join_info_list. We also create transient
2239  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
2240  * cost estimation purposes it is sometimes useful to know the join size under
2241  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
2242  * of course the semi_xxx fields are not set meaningfully within such structs.
2243  */
2244 #ifndef HAVE_SPECIALJOININFO_TYPEDEF
2246 #define HAVE_SPECIALJOININFO_TYPEDEF 1
2247 #endif
2248 
2250 {
2252  Relids min_lefthand; /* base relids in minimum LHS for join */
2253  Relids min_righthand; /* base relids in minimum RHS for join */
2254  Relids syn_lefthand; /* base relids syntactically within LHS */
2255  Relids syn_righthand; /* base relids syntactically within RHS */
2256  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
2257  bool lhs_strict; /* joinclause is strict for some LHS rel */
2258  bool delay_upper_joins; /* can't commute with upper RHS */
2259  /* Remaining fields are set only for JOIN_SEMI jointype: */
2260  bool semi_can_btree; /* true if semi_operators are all btree */
2261  bool semi_can_hash; /* true if semi_operators are all hash */
2262  List *semi_operators; /* OIDs of equality join operators */
2263  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
2264 };
2265 
2266 /*
2267  * Append-relation info.
2268  *
2269  * When we expand an inheritable table or a UNION-ALL subselect into an
2270  * "append relation" (essentially, a list of child RTEs), we build an
2271  * AppendRelInfo for each child RTE. The list of AppendRelInfos indicates
2272  * which child RTEs must be included when expanding the parent, and each node
2273  * carries information needed to translate between columns of the parent and
2274  * columns of the child.
2275  *
2276  * These structs are kept in the PlannerInfo node's append_rel_list, with
2277  * append_rel_array[] providing a convenient lookup method for the struct
2278  * associated with a particular child relid (there can be only one, though
2279  * parent rels may have many entries in append_rel_list).
2280  *
2281  * Note: after completion of the planner prep phase, any given RTE is an
2282  * append parent having entries in append_rel_list if and only if its
2283  * "inh" flag is set. We clear "inh" for plain tables that turn out not
2284  * to have inheritance children, and (in an abuse of the original meaning
2285  * of the flag) we set "inh" for subquery RTEs that turn out to be
2286  * flattenable UNION ALL queries. This lets us avoid useless searches
2287  * of append_rel_list.
2288  *
2289  * Note: the data structure assumes that append-rel members are single
2290  * baserels. This is OK for inheritance, but it prevents us from pulling
2291  * up a UNION ALL member subquery if it contains a join. While that could
2292  * be fixed with a more complex data structure, at present there's not much
2293  * point because no improvement in the plan could result.
2294  */
2295 
2296 typedef struct AppendRelInfo
2297 {
2299 
2300  /*
2301  * These fields uniquely identify this append relationship. There can be
2302  * (in fact, always should be) multiple AppendRelInfos for the same
2303  * parent_relid, but never more than one per child_relid, since a given
2304  * RTE cannot be a child of more than one append parent.
2305  */
2306  Index parent_relid; /* RT index of append parent rel */
2307  Index child_relid; /* RT index of append child rel */
2308 
2309  /*
2310  * For an inheritance appendrel, the parent and child are both regular
2311  * relations, and we store their rowtype OIDs here for use in translating
2312  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
2313  * both subqueries with no named rowtype, and we store InvalidOid here.
2314  */
2315  Oid parent_reltype; /* OID of parent's composite type */
2316  Oid child_reltype; /* OID of child's composite type */
2317 
2318  /*
2319  * The N'th element of this list is a Var or expression representing the
2320  * child column corresponding to the N'th column of the parent. This is
2321  * used to translate Vars referencing the parent rel into references to
2322  * the child. A list element is NULL if it corresponds to a dropped
2323  * column of the parent (this is only possible for inheritance cases, not
2324  * UNION ALL). The list elements are always simple Vars for inheritance
2325  * cases, but can be arbitrary expressions in UNION ALL cases.
2326  *
2327  * Notice we only store entries for user columns (attno > 0). Whole-row
2328  * Vars are special-cased, and system columns (attno < 0) need no special
2329  * translation since their attnos are the same for all tables.
2330  *
2331  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
2332  * when copying into a subquery.
2333  */
2334  List *translated_vars; /* Expressions in the child's Vars */
2335 
2336  /*
2337  * This array simplifies translations in the reverse direction, from
2338  * child's column numbers to parent's. The entry at [ccolno - 1] is the
2339  * 1-based parent column number for child column ccolno, or zero if that
2340  * child column is dropped or doesn't exist in the parent.
2341  */
2342  int num_child_cols; /* length of array */
2343  AttrNumber *parent_colnos; /* array of parent attnos, or zeroes */
2344 
2345  /*
2346  * We store the parent table's OID here for inheritance, or InvalidOid for
2347  * UNION ALL. This is only needed to help in generating error messages if
2348  * an attempt is made to reference a dropped parent column.
2349  */
2350  Oid parent_reloid; /* OID of parent relation */
2351 } AppendRelInfo;
2352 
2353 /*
2354  * Information about a row-identity "resjunk" column in UPDATE/DELETE.
2355  *
2356  * In partitioned UPDATE/DELETE it's important for child partitions to share
2357  * row-identity columns whenever possible, so as not to chew up too many
2358  * targetlist columns. We use these structs to track which identity columns
2359  * have been requested. In the finished plan, each of these will give rise
2360  * to one resjunk entry in the targetlist of the ModifyTable's subplan node.
2361  *
2362  * All the Vars stored in RowIdentityVarInfos must have varno ROWID_VAR, for
2363  * convenience of detecting duplicate requests. We'll replace that, in the
2364  * final plan, with the varno of the generating rel.
2365  *
2366  * Outside this list, a Var with varno ROWID_VAR and varattno k is a reference
2367  * to the k-th element of the row_identity_vars list (k counting from 1).
2368  * We add such a reference to root->processed_tlist when creating the entry,
2369  * and it propagates into the plan tree from there.
2370  */
2371 typedef struct RowIdentityVarInfo
2372 {
2374 
2375  Var *rowidvar; /* Var to be evaluated (but varno=ROWID_VAR) */
2376  int32 rowidwidth; /* estimated average width */
2377  char *rowidname; /* name of the resjunk column */
2378  Relids rowidrels; /* RTE indexes of target rels using this */
2380 
2381 /*
2382  * For each distinct placeholder expression generated during planning, we
2383  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
2384  * This stores info that is needed centrally rather than in each copy of the
2385  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
2386  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
2387  * not just within a query level --- this is so that we need not reassign ID's
2388  * when pulling a subquery into its parent.
2389  *
2390  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
2391  * then allow it to bubble up like a Var until the ph_needed join level.
2392  * ph_needed has the same definition as attr_needed for a regular Var.
2393  *
2394  * The PlaceHolderVar's expression might contain LATERAL references to vars
2395  * coming from outside its syntactic scope. If so, those rels are *not*
2396  * included in ph_eval_at, but they are recorded in ph_lateral.
2397  *
2398  * Notice that when ph_eval_at is a join rather than a single baserel, the
2399  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
2400  * has to be formed below any outer joins that should null the PlaceHolderVar.
2401  *
2402  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
2403  * is actually referenced in the plan tree, so that unreferenced placeholders
2404  * don't result in unnecessary constraints on join order.
2405  */
2406 
2407 typedef struct PlaceHolderInfo
2408 {
2410 
2411  Index phid; /* ID for PH (unique within planner run) */
2412  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
2413  Relids ph_eval_at; /* lowest level we can evaluate value at */
2414  Relids ph_lateral; /* relids of contained lateral refs, if any */
2415  Relids ph_needed; /* highest level the value is needed at */
2416  int32 ph_width; /* estimated attribute width */
2417 } PlaceHolderInfo;
2418 
2419 /*
2420  * This struct describes one potentially index-optimizable MIN/MAX aggregate
2421  * function. MinMaxAggPath contains a list of these, and if we accept that
2422  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
2423  */
2424 typedef struct MinMaxAggInfo
2425 {
2427 
2428  Oid aggfnoid; /* pg_proc Oid of the aggregate */
2429  Oid aggsortop; /* Oid of its sort operator */
2430  Expr *target; /* expression we are aggregating on */
2431  PlannerInfo *subroot; /* modified "root" for planning the subquery */
2432  Path *path; /* access path for subquery */
2433  Cost pathcost; /* estimated cost to fetch first row */
2434  Param *param; /* param for subplan's output */
2435 } MinMaxAggInfo;
2436 
2437 /*
2438  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
2439  * node to another. They can be used to pass values down into subqueries (for
2440  * outer references in subqueries), or up out of subqueries (for the results
2441  * of a subplan), or from a NestLoop plan node into its inner relation (when
2442  * the inner scan is parameterized with values from the outer relation).
2443  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
2444  * the PARAM_EXEC Params it generates.
2445  *
2446  * Outer references are managed via root->plan_params, which is a list of
2447  * PlannerParamItems. While planning a subquery, each parent query level's
2448  * plan_params contains the values required from it by the current subquery.
2449  * During create_plan(), we use plan_params to track values that must be
2450  * passed from outer to inner sides of NestLoop plan nodes.
2451  *
2452  * The item a PlannerParamItem represents can be one of three kinds:
2453  *
2454  * A Var: the slot represents a variable of this level that must be passed
2455  * down because subqueries have outer references to it, or must be passed
2456  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
2457  * will always be zero.
2458  *
2459  * A PlaceHolderVar: this works much like the Var case, except that the
2460  * entry is a PlaceHolderVar node with a contained expression. The PHV
2461  * will have phlevelsup = 0, and the contained expression is adjusted
2462  * to match in level.
2463  *
2464  * An Aggref (with an expression tree representing its argument): the slot
2465  * represents an aggregate expression that is an outer reference for some
2466  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
2467  * is adjusted to match in level.
2468  *
2469  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
2470  * them into one slot, but we do not bother to do that for Aggrefs.
2471  * The scope of duplicate-elimination only extends across the set of
2472  * parameters passed from one query level into a single subquery, or for
2473  * nestloop parameters across the set of nestloop parameters used in a single
2474  * query level. So there is no possibility of a PARAM_EXEC slot being used
2475  * for conflicting purposes.
2476  *
2477  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2478  * from subplans (values that are setParam items for those subplans). These
2479  * IDs need not be tracked via PlannerParamItems, since we do not need any
2480  * duplicate-elimination nor later processing of the represented expressions.
2481  * Instead, we just record the assignment of the slot number by appending to
2482  * root->glob->paramExecTypes.
2483  */
2484 typedef struct PlannerParamItem
2485 {
2487 
2488  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2489  int paramId; /* its assigned PARAM_EXEC slot number */
2491 
2492 /*
2493  * When making cost estimates for a SEMI/ANTI/inner_unique join, there are
2494  * some correction factors that are needed in both nestloop and hash joins
2495  * to account for the fact that the executor can stop scanning inner rows
2496  * as soon as it finds a match to the current outer row. These numbers
2497  * depend only on the selected outer and inner join relations, not on the
2498  * particular paths used for them, so it's worthwhile to calculate them
2499  * just once per relation pair not once per considered path. This struct
2500  * is filled by compute_semi_anti_join_factors and must be passed along
2501  * to the join cost estimation functions.
2502  *
2503  * outer_match_frac is the fraction of the outer tuples that are
2504  * expected to have at least one match.
2505  * match_count is the average number of matches expected for
2506  * outer tuples that have at least one match.
2507  */
2508 typedef struct SemiAntiJoinFactors
2509 {
2513 
2514 /*
2515  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2516  *
2517  * restrictlist contains all of the RestrictInfo nodes for restriction
2518  * clauses that apply to this join
2519  * mergeclause_list is a list of RestrictInfo nodes for available
2520  * mergejoin clauses in this join
2521  * inner_unique is true if each outer tuple provably matches no more
2522  * than one inner tuple
2523  * sjinfo is extra info about special joins for selectivity estimation
2524  * semifactors is as shown above (only valid for SEMI/ANTI/inner_unique joins)
2525  * param_source_rels are OK targets for parameterization of result paths
2526  */
2527 typedef struct JoinPathExtraData
2528 {
2536 
2537 /*
2538  * Various flags indicating what kinds of grouping are possible.
2539  *
2540  * GROUPING_CAN_USE_SORT should be set if it's possible to perform
2541  * sort-based implementations of grouping. When grouping sets are in use,
2542  * this will be true if sorting is potentially usable for any of the grouping
2543  * sets, even if it's not usable for all of them.
2544  *
2545  * GROUPING_CAN_USE_HASH should be set if it's possible to perform
2546  * hash-based implementations of grouping.
2547  *
2548  * GROUPING_CAN_PARTIAL_AGG should be set if the aggregation is of a type
2549  * for which we support partial aggregation (not, for example, grouping sets).
2550  * It says nothing about parallel-safety or the availability of suitable paths.
2551  */
2552 #define GROUPING_CAN_USE_SORT 0x0001
2553 #define GROUPING_CAN_USE_HASH 0x0002
2554 #define GROUPING_CAN_PARTIAL_AGG 0x0004
2555 
2556 /*
2557  * What kind of partitionwise aggregation is in use?
2558  *
2559  * PARTITIONWISE_AGGREGATE_NONE: Not used.
2560  *
2561  * PARTITIONWISE_AGGREGATE_FULL: Aggregate each partition separately, and
2562  * append the results.
2563  *
2564  * PARTITIONWISE_AGGREGATE_PARTIAL: Partially aggregate each partition
2565  * separately, append the results, and then finalize aggregation.
2566  */
2567 typedef enum
2568 {
2573 
2574 /*
2575  * Struct for extra information passed to subroutines of create_grouping_paths
2576  *
2577  * flags indicating what kinds of grouping are possible.
2578  * partial_costs_set is true if the agg_partial_costs and agg_final_costs
2579  * have been initialized.
2580  * agg_partial_costs gives partial aggregation costs.
2581  * agg_final_costs gives finalization costs.
2582  * target_parallel_safe is true if target is parallel safe.
2583  * havingQual gives list of quals to be applied after aggregation.
2584  * targetList gives list of columns to be projected.
2585  * patype is the type of partitionwise aggregation that is being performed.
2586  */
2587 typedef struct
2588 {
2589  /* Data which remains constant once set. */
2590  int flags;
2594 
2595  /* Data which may differ across partitions. */
2601 
2602 /*
2603  * Struct for extra information passed to subroutines of grouping_planner
2604  *
2605  * limit_needed is true if we actually need a Limit plan node.
2606  * limit_tuples is an estimated bound on the number of output tuples,
2607  * or -1 if no LIMIT or couldn't estimate.
2608  * count_est and offset_est are the estimated values of the LIMIT and OFFSET
2609  * expressions computed by preprocess_limit() (see comments for
2610  * preprocess_limit() for more information).
2611  */
2612 typedef struct
2613 {
2616  int64 count_est;
2617  int64 offset_est;
2619 
2620 /*
2621  * For speed reasons, cost estimation for join paths is performed in two
2622  * phases: the first phase tries to quickly derive a lower bound for the
2623  * join cost, and then we check if that's sufficient to reject the path.
2624  * If not, we come back for a more refined cost estimate. The first phase
2625  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2626  * and possibly additional intermediate values. The second phase takes
2627  * these values as inputs to avoid repeating work.
2628  *
2629  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2630  * so seems best to put it here.)
2631  */
2632 typedef struct JoinCostWorkspace
2633 {
2634  /* Preliminary cost estimates --- must not be larger than final ones! */
2635  Cost startup_cost; /* cost expended before fetching any tuples */
2636  Cost total_cost; /* total cost (assuming all tuples fetched) */
2637 
2638  /* Fields below here should be treated as private to costsize.c */
2639  Cost run_cost; /* non-startup cost components */
2640 
2641  /* private for cost_nestloop code */
2642  Cost inner_run_cost; /* also used by cost_mergejoin code */
2644 
2645  /* private for cost_mergejoin code */
2650 
2651  /* private for cost_hashjoin code */
2656 
2657 /*
2658  * AggInfo holds information about an aggregate that needs to be computed.
2659  * Multiple Aggrefs in a query can refer to the same AggInfo by having the
2660  * same 'aggno' value, so that the aggregate is computed only once.
2661  */
2662 typedef struct AggInfo
2663 {
2664  /*
2665  * Link to an Aggref expr this state value is for.
2666  *
2667  * There can be multiple identical Aggref's sharing the same per-agg. This
2668  * points to the first one of them.
2669  */
2671 
2672  int transno;
2673 
2674  /*
2675  * "shareable" is false if this agg cannot share state values with other
2676  * aggregates because the final function is read-write.
2677  */
2679 
2680  /* Oid of the final function or InvalidOid */
2682 
2683 } AggInfo;
2684 
2685 /*
2686  * AggTransInfo holds information about transition state that is used by one
2687  * or more aggregates in the query. Multiple aggregates can share the same
2688  * transition state, if they have the same inputs and the same transition
2689  * function. Aggrefs that share the same transition info have the same
2690  * 'aggtransno' value.
2691  */
2692 typedef struct AggTransInfo
2693 {
2696 
2697  /* Oid of the state transition function */
2699 
2700  /* Oid of the serialization function or InvalidOid */
2702 
2703  /* Oid of the deserialization function or InvalidOid */
2705 
2706  /* Oid of the combine function or InvalidOid */
2708 
2709  /* Oid of state value's datatype */
2715 
2716  /*
2717  * initial value from pg_aggregate entry
2718  */
2721 
2722 } AggTransInfo;
2723 
2724 #endif /* PATHNODES_H */
QualCost eval_cost
Definition: pathnodes.h:2096
bool has_eclass_joins
Definition: pathnodes.h:751
Oid serialfn_oid
Definition: pathnodes.h:2701
struct RowIdentityVarInfo RowIdentityVarInfo
struct TidPath TidPath
struct Path * cheapest_unique_path
Definition: pathnodes.h:700
NodeTag type
Definition: pathnodes.h:1792
List * indexorderbycols
Definition: pathnodes.h:1248
signed short int16
Definition: c.h:428
char maxParallelHazard
Definition: pathnodes.h:130
List * group_pathkeys
Definition: pathnodes.h:296
struct ProjectionPath ProjectionPath
struct UpperUniquePath UpperUniquePath
List * rowMarks
Definition: pathnodes.h:288
struct QualCost QualCost
Relids all_result_relids
Definition: pathnodes.h:276
Relids ph_needed
Definition: pathnodes.h:2415
List * qual
Definition: pathnodes.h:1744
Definition: fmgr.h:56
Selectivity leftendsel
Definition: pathnodes.h:2159
List * path_mergeclauses
Definition: pathnodes.h:1649
UpperRelationKind
Definition: pathnodes.h:67
int join_cur_level
Definition: pathnodes.h:240
List * outersortkeys
Definition: pathnodes.h:1650
List * distinctList
Definition: pathnodes.h:1844
List * unique_for_rels
Definition: pathnodes.h:740
struct HashPath HashPath
JoinPath jpath
Definition: pathnodes.h:1667
Oid finalfn_oid
Definition: pathnodes.h:2681
PathTarget * pathtarget
Definition: pathnodes.h:1183
Query * parse
Definition: pathnodes.h:162
List * statlist
Definition: pathnodes.h:719
LimitOption limitOption
Definition: pathnodes.h:1908
List * returningLists
Definition: pathnodes.h:1893
struct EquivalenceMember EquivalenceMember
Index security_level
Definition: pathnodes.h:2071
OnConflictExpr * onconflict
Definition: pathnodes.h:1895
struct StatisticExtInfo StatisticExtInfo
List * groupClause
Definition: pathnodes.h:1793
Node * limitOffset
Definition: pathnodes.h:1906
Path path
Definition: pathnodes.h:1244
NodeTag type
Definition: pathnodes.h:2298
Path * subpath
Definition: pathnodes.h:1716
Relids ph_eval_at
Definition: pathnodes.h:2413
List * plan_params
Definition: pathnodes.h:176
PlaceHolderVar * ph_var
Definition: pathnodes.h:2412
uint32 est_entries
Definition: pathnodes.h:1519
IndexOptInfo * indexinfo
Definition: pathnodes.h:1245
SemiAntiJoinFactors semifactors
Definition: pathnodes.h:2533
Index nominalRelation
Definition: pathnodes.h:1887
Oid * indexcollations
Definition: pathnodes.h:852
bool hasJoinRTEs
Definition: pathnodes.h:346
Path * fdw_outerpath
Definition: pathnodes.h:1399
RelOptKind reloptkind
Definition: pathnodes.h:678
VolatileFunctionStatus
Definition: pathnodes.h:1077
Relids * attr_needed
Definition: pathnodes.h:714
bool ec_merging_done
Definition: pathnodes.h:251
PartitionwiseAggregateType
Definition: pathnodes.h:2567
List * custom_paths
Definition: pathnodes.h:1429
bool * isUsedSubplan
Definition: pathnodes.h:373
List * query_pathkeys
Definition: pathnodes.h:294
int num_batches
Definition: pathnodes.h:1669
List * join_info_list
Definition: pathnodes.h:266
Relids required_relids
Definition: pathnodes.h:2077
SetOpStrategy strategy
Definition: pathnodes.h:1843
Relids min_righthand
Definition: pathnodes.h:2253
AggStrategy aggstrategy
Definition: pathnodes.h:1771
bool materialize_inner
Definition: pathnodes.h:1653
void * join_search_private
Definition: pathnodes.h:376
int num_child_cols
Definition: pathnodes.h:2342
Selectivity right_mcvfreq
Definition: pathnodes.h:2123
Relids curOuterRels
Definition: pathnodes.h:368
List * qual
Definition: pathnodes.h:1776
PlannerInfo * parent_root
Definition: pathnodes.h:168
bool leakproof
Definition: pathnodes.h:2066
Index ec_min_security
Definition: pathnodes.h:999
Expr * orclause
Definition: pathnodes.h:2090
Selectivity outer_match_frac
Definition: pathnodes.h:2510
Path * innerjoinpath
Definition: pathnodes.h:1591
struct IncrementalSortPath IncrementalSortPath
List * indextlist
Definition: pathnodes.h:866
AttrNumber * parent_colnos
Definition: pathnodes.h:2343
Cardinality numGroups
Definition: pathnodes.h:1796
struct Path * cheapest_startup_path
Definition: pathnodes.h:698
Oid userid
Definition: pathnodes.h:733
QualCost finalCost
Definition: pathnodes.h:59
struct PartitionSchemeData PartitionSchemeData
Relids em_nullable_relids
Definition: pathnodes.h:1039
int lastPlanNodeId
Definition: pathnodes.h:120
Oid reltablespace
Definition: pathnodes.h:710
Path * subpath
Definition: pathnodes.h:1841
struct RollupData RollupData
List * baserestrictinfo
Definition: pathnodes.h:745
NodeTag type
Definition: pathnodes.h:1178
List * ec_derives
Definition: pathnodes.h:991
struct BitmapOrPath BitmapOrPath
AggClauseCosts agg_partial_costs
Definition: pathnodes.h:2592
Relids clause_relids
Definition: pathnodes.h:2074
struct UniquePath UniquePath
Param * param
Definition: pathnodes.h:2434
struct AppendPath AppendPath
int parallel_workers
Definition: pathnodes.h:1189
bool pseudoconstant
Definition: pathnodes.h:2064
bool consider_param_startup
Definition: pathnodes.h:688
RelOptKind
Definition: pathnodes.h:639
List * resultRelations
Definition: pathnodes.h:106
bool is_hashed
Definition: pathnodes.h:1798
ParamPathInfo * param_info
Definition: pathnodes.h:1185
struct MemoizePath MemoizePath
Definition: nodes.h:536
List * part_schemes
Definition: pathnodes.h:301
PartitionwiseAggregateType patype
Definition: pathnodes.h:2599
bool singlerow
Definition: pathnodes.h:1516
List * appendRelations
Definition: pathnodes.h:108
Oid * sortopfamily
Definition: pathnodes.h:855
struct MergeAppendPath MergeAppendPath
struct BitmapAndPath BitmapAndPath
List * partial_pathlist
Definition: pathnodes.h:697
Oid reltablespace
Definition: pathnodes.h:839
Relids left_relids
Definition: pathnodes.h:2086
List * join_rel_list
Definition: pathnodes.h:229
struct CustomPath CustomPath
struct AggClauseCosts AggClauseCosts
bool ec_below_outer_join
Definition: pathnodes.h:996
uint32 flags
Definition: pathnodes.h:1427
uint32 BlockNumber
Definition: block.h:31
struct JoinPathExtraData JoinPathExtraData
EquivalenceClass * right_ec
Definition: pathnodes.h:2108
List * cheapest_parameterized_paths
Definition: pathnodes.h:701
Cardinality limit_tuples
Definition: pathnodes.h:341
List * minmax_aggs
Definition: pathnodes.h:333
bool single_copy
Definition: pathnodes.h:1561
bool hypothetical
Definition: pathnodes.h:877
Index baserestrict_min_security
Definition: pathnodes.h:747
UniquePathMethod umethod
Definition: pathnodes.h:1547
struct GatherPath GatherPath
Path * subpath
Definition: pathnodes.h:1502
Cardinality outer_skip_rows
Definition: pathnodes.h:2648
bool transtypeByVal
Definition: pathnodes.h:2713
List * indexclauses
Definition: pathnodes.h:1246
NodeTag type
Definition: pathnodes.h:676
Relids all_partrels
Definition: pathnodes.h:773
Expr * aggfilter
Definition: pathnodes.h:2695
double Selectivity
Definition: nodes.h:669
Oid combinefn_oid
Definition: pathnodes.h:2707
List * agginfos
Definition: pathnodes.h:357
Index ec_max_security
Definition: pathnodes.h:1000
bool useridiscurrent
Definition: pathnodes.h:734
AggSplit aggsplit
Definition: pathnodes.h:1772
bool immediate
Definition: pathnodes.h:876
QualCost transCost
Definition: pathnodes.h:58
Cardinality ppi_rows
Definition: pathnodes.h:1142
Selectivity bitmapselectivity
Definition: pathnodes.h:1331
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: pathnodes.h:1822
List ** nullable_partexprs
Definition: pathnodes.h:775
struct ForeignKeyOptInfo ForeignKeyOptInfo
Definition: primnodes.h:186
AttrNumber * grouping_map
Definition: pathnodes.h:332
List * fkey_list
Definition: pathnodes.h:292
int tree_height
Definition: pathnodes.h:845
Bitmapset * live_parts
Definition: pathnodes.h:770
bool hasRecursion
Definition: pathnodes.h:352
struct PlaceHolderInfo PlaceHolderInfo
List * mergeopfamilies
Definition: pathnodes.h:2104
List * translated_vars
Definition: pathnodes.h:2334
struct AppendRelInfo AppendRelInfo
SetOpStrategy
Definition: nodes.h:818
Cost inner_rescan_run_cost
Definition: pathnodes.h:2643
struct EquivalenceClass EquivalenceClass
Oid parent_reltype
Definition: pathnodes.h:2315
Relids syn_lefthand
Definition: pathnodes.h:2254
List * rowMarks
Definition: pathnodes.h:1870
int pk_strategy
Definition: pathnodes.h:1068
Cost startup
Definition: pathnodes.h:45
double allvisfrac
Definition: pathnodes.h:722
Relids outer_relids
Definition: pathnodes.h:2080
int transtypeLen
Definition: pathnodes.h:2712
signed int int32
Definition: c.h:429
static struct cvec * eclass(struct vars *v, chr c, int cases)
Definition: regc_locale.c:504
List * bitmapquals
Definition: pathnodes.h:1330
Selectivity norm_selec
Definition: pathnodes.h:2097
List * custom_private
Definition: pathnodes.h:1430
uint64 transitionSpace
Definition: pathnodes.h:1812
JoinType
Definition: nodes.h:704
Path * subpath
Definition: pathnodes.h:1513
int first_partial_path
Definition: pathnodes.h:1454
WindowClause * winclause
Definition: pathnodes.h:1832
struct MaterialPath MaterialPath
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:186
List * bitmapquals
Definition: pathnodes.h:1343
int num_workers
Definition: pathnodes.h:1562
List * multiexpr_params
Definition: pathnodes.h:246
BlockNumber pages
Definition: pathnodes.h:843
NodeTag pathtype
Definition: pathnodes.h:1180
Relids syn_righthand
Definition: pathnodes.h:2255
List * subpaths
Definition: pathnodes.h:1452
PlannerInfo * subroot
Definition: pathnodes.h:725
NodeTag type
Definition: pathnodes.h:1064
SetOpCmd cmd
Definition: pathnodes.h:1842
struct LockRowsPath LockRowsPath
List * tidrangequals
Definition: pathnodes.h:1369
bool dependsOnRole
Definition: pathnodes.h:124
bool consider_startup
Definition: pathnodes.h:687
Definition: dynahash.c:219
struct ParamPathInfo ParamPathInfo
Relids lateral_relids
Definition: pathnodes.h:706
Cost per_tuple
Definition: pathnodes.h:46
const struct CustomPathMethods * methods
Definition: pathnodes.h:1431
uint32 amflags
Definition: pathnodes.h:728
int wt_param_id
Definition: pathnodes.h:364
Path * subpath
Definition: pathnodes.h:1831
bool skip_mark_restore
Definition: pathnodes.h:1652
RelOptInfo * rel
Definition: pathnodes.h:840
bool amoptionalkey
Definition: pathnodes.h:881
Cardinality calls
Definition: pathnodes.h:1518
SpecialJoinInfo * sjinfo
Definition: pathnodes.h:2532
struct GroupingSetData GroupingSetData
List ** partexprs
Definition: pathnodes.h:774
bool parallelModeNeeded
Definition: pathnodes.h:128
Relids all_baserels
Definition: pathnodes.h:210
bool pk_nulls_first
Definition: pathnodes.h:1069
List * paramExecTypes
Definition: pathnodes.h:114
Relids param_source_rels
Definition: pathnodes.h:2534
Cardinality limit_tuples
Definition: pathnodes.h:1455
List * row_identity_vars
Definition: pathnodes.h:286
NodeTag type
Definition: pathnodes.h:1139
struct PathKey PathKey
EquivalenceMember * left_em
Definition: pathnodes.h:2109
struct AggPath AggPath
Cost indextotalcost
Definition: pathnodes.h:1250
Cost startup_cost
Definition: pathnodes.h:1193
List * semi_rhs_exprs
Definition: pathnodes.h:2263
NodeTag type
Definition: pathnodes.h:1109
bool hasLateralRTEs
Definition: pathnodes.h:347
List * indexcols
Definition: pathnodes.h:1295
Path * subpath
Definition: pathnodes.h:1905
struct ModifyTablePath ModifyTablePath
List * joinrestrictinfo
Definition: pathnodes.h:1593
bool parallelModeOK
Definition: pathnodes.h:126
List * aggtransinfos
Definition: pathnodes.h:358
EquivalenceClass * parent_ec
Definition: pathnodes.h:2093
bool partColsUpdated
Definition: pathnodes.h:1889
struct GatherMergePath GatherMergePath
RTEKind
Definition: parsenodes.h:988
Bitmapset * rewindPlanIDs
Definition: pathnodes.h:100
RelOptInfo * parent
Definition: pathnodes.h:1182
AttrNumber indexcol
Definition: pathnodes.h:1294
bool hasAlternativeSubPlans
Definition: pathnodes.h:351
List * uniq_exprs
Definition: pathnodes.h:1549
Path * bitmapqual
Definition: pathnodes.h:1318
Cardinality numGroups
Definition: pathnodes.h:1847
bool initValueIsNull
Definition: pathnodes.h:2720
struct ForeignPath ForeignPath
bool outerjoin_delayed
Definition: pathnodes.h:2060
Path path
Definition: pathnodes.h:1741
int numOrderedAggs
Definition: pathnodes.h:359
bool hasNonSerialAggs
Definition: pathnodes.h:361
List * hash_operators
Definition: pathnodes.h:1514
List * ec_sources
Definition: pathnodes.h:990
struct Path * cheapest_total_path
Definition: pathnodes.h:699
Cardinality inner_rows
Definition: pathnodes.h:2647
Selectivity rightstartsel
Definition: pathnodes.h:2160
List * curOuterParams
Definition: pathnodes.h:369
struct RelOptInfo RelOptInfo
struct JoinPath JoinPath
Cardinality numGroups
Definition: pathnodes.h:1860
int32 aggtransspace
Definition: pathnodes.h:2714
Selectivity indexselectivity
Definition: pathnodes.h:1251
List * subplans
Definition: pathnodes.h:96
bool amcanorderbyop
Definition: pathnodes.h:880
struct RestrictInfo * rinfo
Definition: pathnodes.h:1291
List * joininfo
Definition: pathnodes.h:749
Relids ec_relids
Definition: pathnodes.h:992
PlannerGlobal * glob
Definition: pathnodes.h:164
bool outer_is_left
Definition: pathnodes.h:2114
bool partColsUpdated
Definition: pathnodes.h:379
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:736
List * left_join_clauses
Definition: pathnodes.h:255
int nparts
Definition: pathnodes.h:761
struct AggTransInfo AggTransInfo
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: pathnodes.h:263
List * groupClause
Definition: pathnodes.h:1775
Index * sortgrouprefs
Definition: pathnodes.h:1111
List * mergeclause_list
Definition: pathnodes.h:2530
struct Path Path
unsigned int uint32
Definition: c.h:441
AttrNumber flagColIdx
Definition: pathnodes.h:1845
Relids relids
Definition: pathnodes.h:681
AggStrategy aggstrategy
Definition: pathnodes.h:1809
Selectivity outer_selec
Definition: pathnodes.h:2100
Path * subpath
Definition: pathnodes.h:1560
struct GroupingSetsPath GroupingSetsPath
Selectivity bitmapselectivity
Definition: pathnodes.h:1344
bool partbounds_merged
Definition: pathnodes.h:765
RelOptInfo * rel
Definition: pathnodes.h:937
struct MinMaxAggPath MinMaxAggPath
int simple_rel_array_size
Definition: pathnodes.h:187
bool shareable
Definition: pathnodes.h:2678
Oid aggtranstype
Definition: pathnodes.h:2710
bool amhasgetbitmap
Definition: pathnodes.h:885
List * canon_pathkeys
Definition: pathnodes.h:253
struct PartitionSchemeData * PartitionScheme
Definition: pathnodes.h:422
JoinPath jpath
Definition: pathnodes.h:1608
List * non_unique_for_rels
Definition: pathnodes.h:742
List * indexquals
Definition: pathnodes.h:1292
VolatileFunctionStatus has_volatile
Definition: pathnodes.h:2068
List * ppilist
Definition: pathnodes.h:696
Index relid
Definition: pathnodes.h:709
Oid hasheqoperator
Definition: pathnodes.h:2126
List * sort_pathkeys
Definition: pathnodes.h:299
struct PlaceHolderVar PlaceHolderVar
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:194
EquivalenceMember * right_em
Definition: pathnodes.h:2110
Relids lateral_referencers
Definition: pathnodes.h:717
Expr * clause
Definition: pathnodes.h:2056
Path * subpath
Definition: pathnodes.h:1869
struct PlannerGlobal PlannerGlobal
int32 aggtranstypmod
Definition: pathnodes.h:2711
Oid serverid
Definition: pathnodes.h:732
List * ec_opfamilies
Definition: pathnodes.h:987
List * exprs
Definition: pathnodes.h:1110
List * window_pathkeys
Definition: pathnodes.h:297
List * indrestrictinfo
Definition: pathnodes.h:868
Relids direct_lateral_relids
Definition: pathnodes.h:705
Path * outerjoinpath
Definition: pathnodes.h:1590
struct MergeScanSelCache MergeScanSelCache
List * invalItems
Definition: pathnodes.h:112
struct MergePath MergePath
struct GroupResultPath GroupResultPath
bool consider_partitionwise_join
Definition: pathnodes.h:754
Cardinality inner_rows_total
Definition: pathnodes.h:1670
double Cardinality
Definition: nodes.h:671
List * param_exprs
Definition: pathnodes.h:1515
NodeTag type
Definition: pathnodes.h:160
Datum initValue
Definition: pathnodes.h:2719
Relids nullable_relids
Definition: pathnodes.h:2083
bool delay_upper_joins
Definition: pathnodes.h:2258
int transno
Definition: pathnodes.h:2672
struct NestPath NestPath
List * indexorderbys
Definition: pathnodes.h:1247
uintptr_t Datum
Definition: postgres.h:411
struct RestrictInfo RestrictInfo
struct ProjectSetPath ProjectSetPath
struct IndexClause IndexClause
int rel_parallel_workers
Definition: pathnodes.h:727
List * groupClause
Definition: pathnodes.h:1743
List * append_rel_list
Definition: pathnodes.h:284
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct LimitPath LimitPath
struct AppendRelInfo ** append_rel_array
Definition: pathnodes.h:202
Index lastPHId
Definition: pathnodes.h:116
List * cte_plan_ids
Definition: pathnodes.h:244
List * mmaggregates
Definition: pathnodes.h:1821
Relids ph_lateral
Definition: pathnodes.h:2414
struct PartitionBoundInfoData * boundinfo
Definition: pathnodes.h:764
List * tidquals
Definition: pathnodes.h:1357
Path * subpath
Definition: pathnodes.h:1742
unsigned int Index
Definition: c.h:549
struct GroupPath GroupPath
RTEKind rtekind
Definition: pathnodes.h:711
List * indexlist
Definition: pathnodes.h:718
List * init_plans
Definition: pathnodes.h:242
List * in_operators
Definition: pathnodes.h:1548
bool hasPseudoConstantQuals
Definition: pathnodes.h:349
bool amhasgettuple
Definition: pathnodes.h:884
List * distinct_pathkeys
Definition: pathnodes.h:298
Cardinality numGroups
Definition: pathnodes.h:1773
List * args
Definition: pathnodes.h:2694
bool is_pushed_down
Definition: pathnodes.h:2058
void * fdw_private
Definition: pathnodes.h:737
VolatileFunctionStatus has_volatile_expr
Definition: pathnodes.h:1114
Cost total_cost
Definition: pathnodes.h:1194
NodeTag type
Definition: pathnodes.h:836
CostSelector
Definition: pathnodes.h:34
Selectivity left_bucketsize
Definition: pathnodes.h:2120
int firstFlag
Definition: pathnodes.h:1846
List * pathkeys
Definition: pathnodes.h:1196
Cardinality limit_tuples
Definition: pathnodes.h:2615
Relids right_relids
Definition: pathnodes.h:2087
uint64 transitionSpace
Definition: pathnodes.h:1774
BlockNumber pages
Definition: pathnodes.h:720
Selectivity tuple_fraction
Definition: pathnodes.h:340
Path path
Definition: pathnodes.h:1583
struct BitmapHeapPath BitmapHeapPath
ParamListInfo boundParams
Definition: pathnodes.h:94
Expr * target
Definition: pathnodes.h:2430
List * eq_classes
Definition: pathnodes.h:249
List ** join_rel_level
Definition: pathnodes.h:239
UniquePathMethod
Definition: pathnodes.h:1536
NodeTag type
Definition: pathnodes.h:92
Path * subpath
Definition: pathnodes.h:1702
bool parallel_safe
Definition: pathnodes.h:1188
List * lateral_vars
Definition: pathnodes.h:716
struct WindowAggPath WindowAggPath
Cardinality rows
Definition: pathnodes.h:684
struct PlannerParamItem PlannerParamItem
struct FmgrInfo * partsupfunc
Definition: pathnodes.h:419
Index rootRelation
Definition: pathnodes.h:1888
JoinType jointype
Definition: pathnodes.h:2256
EquivalenceClass * pk_eclass
Definition: pathnodes.h:1066
Bitmapset * outer_params
Definition: pathnodes.h:177
Selectivity left_mcvfreq
Definition: pathnodes.h:2122
List * ppi_clauses
Definition: pathnodes.h:1143
struct RelOptInfo ** part_rels
Definition: pathnodes.h:768
struct Path * non_recursive_path
Definition: pathnodes.h:365
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:540
Oid hashjoinoperator
Definition: pathnodes.h:2117
NodeTag type
Definition: pathnodes.h:2054
QualCost cost
Definition: pathnodes.h:1112
AggSplit
Definition: nodes.h:788
Cardinality limit_tuples
Definition: pathnodes.h:1477
bool ec_has_volatile
Definition: pathnodes.h:995
List * relationOids
Definition: pathnodes.h:110
List * subroots
Definition: pathnodes.h:98
bool amsearcharray
Definition: pathnodes.h:882
struct HTAB * join_rel_hash
Definition: pathnodes.h:230
bool inner_unique
Definition: pathnodes.h:1587
Index qual_security_level
Definition: pathnodes.h:343
Oid deserialfn_oid
Definition: pathnodes.h:2704
bool consider_parallel
Definition: pathnodes.h:689
int nkeycolumns
Definition: pathnodes.h:849
List * innersortkeys
Definition: pathnodes.h:1651
Cardinality inner_skip_rows
Definition: pathnodes.h:2649
Path * subpath
Definition: pathnodes.h:1770
Oid * opcintype
Definition: pathnodes.h:854
LimitOption
Definition: nodes.h:843
Bitmapset * Relids
Definition: pathnodes.h:28
Cardinality tuples
Definition: pathnodes.h:844
Index query_level
Definition: pathnodes.h:166
Oid pk_opfamily
Definition: pathnodes.h:1067
Path path
Definition: pathnodes.h:1904
Path path
Definition: pathnodes.h:1356
bool amcanmarkpos
Definition: pathnodes.h:887
Cardinality numGroups
Definition: pathnodes.h:1787
Oid * opfamily
Definition: pathnodes.h:853
List * withCheckOptionLists
Definition: pathnodes.h:1892
Cardinality total_table_pages
Definition: pathnodes.h:337
bool * isAltSubplan
Definition: pathnodes.h:372
List * finalrtable
Definition: pathnodes.h:102
AggStrategy
Definition: nodes.h:766
Bitmapset * keys
Definition: pathnodes.h:939
Index phlevelsup
Definition: pathnodes.h:2184
Index lastRowMarkId
Definition: pathnodes.h:118
AttrNumber max_attr
Definition: pathnodes.h:713
Selectivity match_count
Definition: pathnodes.h:2511
Selectivity right_bucketsize
Definition: pathnodes.h:2121
EquivalenceClass * left_ec
Definition: pathnodes.h:2107
struct JoinCostWorkspace JoinCostWorkspace
Relids nullable_baserels
Definition: pathnodes.h:218
struct RecursiveUnionPath RecursiveUnionPath
List * fdw_private
Definition: pathnodes.h:1400
struct TidRangePath TidRangePath
SetOpCmd
Definition: nodes.h:810
JoinType jointype
Definition: pathnodes.h:1585
List * semi_operators
Definition: pathnodes.h:2262
ScanDirection indexscandir
Definition: pathnodes.h:1249
CmdType operation
Definition: pathnodes.h:1885
struct MinMaxAggInfo MinMaxAggInfo
struct SubqueryScanPath SubqueryScanPath
Relids leaf_result_relids
Definition: pathnodes.h:277
List * placeholder_list
Definition: pathnodes.h:290
List * resultRelations
Definition: pathnodes.h:1890
Cardinality outer_rows
Definition: pathnodes.h:2646
Size transitionSpace
Definition: pathnodes.h:60
bool hashable
Definition: pathnodes.h:1797
bool hasHavingQual
Definition: pathnodes.h:348
JoinPath jpath
Definition: pathnodes.h:1648
PartitionScheme part_scheme
Definition: pathnodes.h:760
Cardinality inner_rows_total
Definition: pathnodes.h:2654
List * updateColnosLists
Definition: pathnodes.h:1891
bool parallel_aware
Definition: pathnodes.h:1187
int * indexkeys
Definition: pathnodes.h:850
Definition: c.h:621
List * path_hashclauses
Definition: pathnodes.h:1668
struct PathTarget PathTarget
List * initial_rels
Definition: pathnodes.h:304
List * pathlist
Definition: pathnodes.h:695
Relids ppi_req_outer
Definition: pathnodes.h:1141
MemoryContext planner_cxt
Definition: pathnodes.h:335
bool hasNonPartialAggs
Definition: pathnodes.h:360
List * right_join_clauses
Definition: pathnodes.h:259
Index child_relid
Definition: pathnodes.h:2307
bool * canreturn
Definition: pathnodes.h:859
Cardinality rows
Definition: pathnodes.h:1192
struct IndexPath IndexPath
bool amsearchnulls
Definition: pathnodes.h:883
List * partition_qual
Definition: pathnodes.h:767
bool * nulls_first
Definition: pathnodes.h:857
struct SetOpPath SetOpPath
Path * subpath
Definition: pathnodes.h:1690
NodeTag type
Definition: pathnodes.h:1290
Index parent_relid
Definition: pathnodes.h:2306
bool * reverse_sort
Definition: pathnodes.h:856
PartitionDirectory partition_directory
Definition: pathnodes.h:132
bytea ** opclassoptions
Definition: pathnodes.h:858
List * processed_tlist
Definition: pathnodes.h:321
List * indpred
Definition: pathnodes.h:864
int32 * attr_widths
Definition: pathnodes.h:715
AggClauseCosts agg_final_costs
Definition: pathnodes.h:2593
Node * limitCount
Definition: pathnodes.h:1907
List * finalrowmarks
Definition: pathnodes.h:104
struct SortPath SortPath
Definition: pg_list.h:50
Path path
Definition: pathnodes.h:1715
struct PathTarget * reltarget
Definition: pathnodes.h:692
Relids min_lefthand
Definition: pathnodes.h:2252
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: pathnodes.h:746
List * subplan_params
Definition: pathnodes.h:726
Path path
Definition: pathnodes.h:1840
NodeTag type
Definition: pathnodes.h:2426
CmdType
Definition: nodes.h:680
List * gsets_data
Definition: pathnodes.h:1795
Bitmapset * eclass_indexes
Definition: pathnodes.h:723
Path path
Definition: pathnodes.h:1769
struct EquivalenceClass * ec_merged
Definition: pathnodes.h:1001
Selectivity rightendsel
Definition: pathnodes.h:2161
bool amcanparallel
Definition: pathnodes.h:886
double Cost
Definition: nodes.h:670
Aggref * representative_aggref
Definition: pathnodes.h:2670
List * scansel_cache
Definition: pathnodes.h:2111
struct AggInfo AggInfo
List * update_colnos
Definition: pathnodes.h:329
Selectivity leftstartsel
Definition: pathnodes.h:2158
List * ec_members
Definition: pathnodes.h:989
List * indexprs
Definition: pathnodes.h:863
Relids top_parent_relids
Definition: pathnodes.h:756
bool transientPlan
Definition: pathnodes.h:122
List * gsets
Definition: pathnodes.h:1794
bool is_dummy_rel(RelOptInfo *rel)
Definition: joinrels.c:1212
Path * subpath
Definition: pathnodes.h:1546
PlannerInfo * subroot
Definition: pathnodes.h:2431
AttrNumber min_attr
Definition: pathnodes.h:712
Cardinality tuples
Definition: pathnodes.h:721