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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_DISTINCT, /* result of "SELECT DISTINCT", if any */
75  UPPERREL_ORDERED, /* result of ORDER BY, if any */
76  UPPERREL_FINAL /* result of any remaining top-level actions */
77  /* NB: UPPERREL_FINAL must be last enum entry; it's used to size arrays */
79 
80 /*----------
81  * PlannerGlobal
82  * Global information for planning/optimization
83  *
84  * PlannerGlobal holds state for an entire planner invocation; this state
85  * is shared across all levels of sub-Queries that exist in the command being
86  * planned.
87  *----------
88  */
89 typedef struct PlannerGlobal
90 {
92 
93  ParamListInfo boundParams; /* Param values provided to planner() */
94 
95  List *subplans; /* Plans for SubPlan nodes */
96 
97  List *subroots; /* PlannerInfos for SubPlan nodes */
98 
99  Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */
100 
101  List *finalrtable; /* "flat" rangetable for executor */
102 
103  List *finalrowmarks; /* "flat" list of PlanRowMarks */
104 
105  List *resultRelations; /* "flat" list of integer RT indexes */
106 
107  List *appendRelations; /* "flat" list of AppendRelInfos */
108 
109  List *relationOids; /* OIDs of relations the plan depends on */
110 
111  List *invalItems; /* other dependencies, as PlanInvalItems */
112 
113  List *paramExecTypes; /* type OIDs for PARAM_EXEC Params */
114 
115  Index lastPHId; /* highest PlaceHolderVar ID assigned */
116 
117  Index lastRowMarkId; /* highest PlanRowMark ID assigned */
118 
119  int lastPlanNodeId; /* highest plan node ID assigned */
120 
121  bool transientPlan; /* redo plan when TransactionXmin changes? */
122 
123  bool dependsOnRole; /* is plan specific to current role? */
124 
125  bool parallelModeOK; /* parallel mode potentially OK? */
126 
127  bool parallelModeNeeded; /* parallel mode actually required? */
128 
129  char maxParallelHazard; /* worst PROPARALLEL hazard level */
130 
131  PartitionDirectory partition_directory; /* partition descriptors */
132 } PlannerGlobal;
133 
134 /* macro for fetching the Plan associated with a SubPlan node */
135 #define planner_subplan_get_plan(root, subplan) \
136  ((Plan *) list_nth((root)->glob->subplans, (subplan)->plan_id - 1))
137 
138 
139 /*----------
140  * PlannerInfo
141  * Per-query information for planning/optimization
142  *
143  * This struct is conventionally called "root" in all the planner routines.
144  * It holds links to all of the planner's working state, in addition to the
145  * original Query. Note that at present the planner extensively modifies
146  * the passed-in Query data structure; someday that should stop.
147  *
148  * For reasons explained in optimizer/optimizer.h, we define the typedef
149  * either here or in that header, whichever is read first.
150  *----------
151  */
152 #ifndef HAVE_PLANNERINFO_TYPEDEF
153 typedef struct PlannerInfo PlannerInfo;
154 #define HAVE_PLANNERINFO_TYPEDEF 1
155 #endif
156 
158 {
160 
161  Query *parse; /* the Query being planned */
162 
163  PlannerGlobal *glob; /* global info for current planner run */
164 
165  Index query_level; /* 1 at the outermost Query */
166 
167  PlannerInfo *parent_root; /* NULL at outermost Query */
168 
169  /*
170  * plan_params contains the expressions that this query level needs to
171  * make available to a lower query level that is currently being planned.
172  * outer_params contains the paramIds of PARAM_EXEC Params that outer
173  * query levels will make available to this query level.
174  */
175  List *plan_params; /* list of PlannerParamItems, see below */
177 
178  /*
179  * simple_rel_array holds pointers to "base rels" and "other rels" (see
180  * comments for RelOptInfo for more info). It is indexed by rangetable
181  * index (so entry 0 is always wasted). Entries can be NULL when an RTE
182  * does not correspond to a base relation, such as a join RTE or an
183  * unreferenced view RTE; or if the RelOptInfo hasn't been made yet.
184  */
185  struct RelOptInfo **simple_rel_array; /* All 1-rel RelOptInfos */
186  int simple_rel_array_size; /* allocated size of array */
187 
188  /*
189  * simple_rte_array is the same length as simple_rel_array and holds
190  * pointers to the associated rangetable entries. Using this is a shade
191  * faster than using rt_fetch(), mostly due to fewer indirections.
192  */
193  RangeTblEntry **simple_rte_array; /* rangetable as an array */
194 
195  /*
196  * append_rel_array is the same length as the above arrays, and holds
197  * pointers to the corresponding AppendRelInfo entry indexed by
198  * child_relid, or NULL if the rel is not an appendrel child. The array
199  * itself is not allocated if append_rel_list is empty.
200  */
202 
203  /*
204  * all_baserels is a Relids set of all base relids (but not "other"
205  * relids) in the query; that is, the Relids identifier of the final join
206  * we need to form. This is computed in make_one_rel, just before we
207  * start making Paths.
208  */
210 
211  /*
212  * nullable_baserels is a Relids set of base relids that are nullable by
213  * some outer join in the jointree; these are rels that are potentially
214  * nullable below the WHERE clause, SELECT targetlist, etc. This is
215  * computed in deconstruct_jointree.
216  */
218 
219  /*
220  * join_rel_list is a list of all join-relation RelOptInfos we have
221  * considered in this planning run. For small problems we just scan the
222  * list to do lookups, but when there are many join relations we build a
223  * hash table for faster lookups. The hash table is present and valid
224  * when join_rel_hash is not NULL. Note that we still maintain the list
225  * even when using the hash table for lookups; this simplifies life for
226  * GEQO.
227  */
228  List *join_rel_list; /* list of join-relation RelOptInfos */
229  struct HTAB *join_rel_hash; /* optional hashtable for join relations */
230 
231  /*
232  * When doing a dynamic-programming-style join search, join_rel_level[k]
233  * is a list of all join-relation RelOptInfos of level k, and
234  * join_cur_level is the current level. New join-relation RelOptInfos are
235  * automatically added to the join_rel_level[join_cur_level] list.
236  * join_rel_level is NULL if not in use.
237  */
238  List **join_rel_level; /* lists of join-relation RelOptInfos */
239  int join_cur_level; /* index of list being extended */
240 
241  List *init_plans; /* init SubPlans for query */
242 
243  List *cte_plan_ids; /* per-CTE-item list of subplan IDs */
244 
245  List *multiexpr_params; /* List of Lists of Params for MULTIEXPR
246  * subquery outputs */
247 
248  List *eq_classes; /* list of active EquivalenceClasses */
249 
250  bool ec_merging_done; /* set true once ECs are canonical */
251 
252  List *canon_pathkeys; /* list of "canonical" PathKeys */
253 
254  List *left_join_clauses; /* list of RestrictInfos for mergejoinable
255  * outer join clauses w/nonnullable var on
256  * left */
257 
258  List *right_join_clauses; /* list of RestrictInfos for mergejoinable
259  * outer join clauses w/nonnullable var on
260  * right */
261 
262  List *full_join_clauses; /* list of RestrictInfos for mergejoinable
263  * full join clauses */
264 
265  List *join_info_list; /* list of SpecialJoinInfos */
266 
267  /*
268  * all_result_relids is empty for SELECT, otherwise it contains at least
269  * parse->resultRelation. For UPDATE/DELETE across an inheritance or
270  * partitioning tree, the result rel's child relids are added. When using
271  * multi-level partitioning, intermediate partitioned rels are included.
272  * leaf_result_relids is similar except that only actual result tables,
273  * not partitioned tables, are included in it.
274  */
275  Relids all_result_relids; /* set of all result relids */
276  Relids leaf_result_relids; /* set of all leaf relids */
277 
278  /*
279  * Note: for AppendRelInfos describing partitions of a partitioned table,
280  * we guarantee that partitions that come earlier in the partitioned
281  * table's PartitionDesc will appear earlier in append_rel_list.
282  */
283  List *append_rel_list; /* list of AppendRelInfos */
284 
285  List *row_identity_vars; /* list of RowIdentityVarInfos */
286 
287  List *rowMarks; /* list of PlanRowMarks */
288 
289  List *placeholder_list; /* list of PlaceHolderInfos */
290 
291  List *fkey_list; /* list of ForeignKeyOptInfos */
292 
293  List *query_pathkeys; /* desired pathkeys for query_planner() */
294 
295  List *group_pathkeys; /* groupClause pathkeys, if any */
296  List *window_pathkeys; /* pathkeys of bottom window, if any */
297  List *distinct_pathkeys; /* distinctClause pathkeys, if any */
298  List *sort_pathkeys; /* sortClause pathkeys, if any */
299 
300  List *part_schemes; /* Canonicalised partition schemes used in the
301  * query. */
302 
303  List *initial_rels; /* RelOptInfos we are now trying to join */
304 
305  /* Use fetch_upper_rel() to get any particular upper rel */
306  List *upper_rels[UPPERREL_FINAL + 1]; /* upper-rel RelOptInfos */
307 
308  /* Result tlists chosen by grouping_planner for upper-stage processing */
309  struct PathTarget *upper_targets[UPPERREL_FINAL + 1];
310 
311  /*
312  * The fully-processed targetlist is kept here. It differs from
313  * parse->targetList in that (for INSERT) it's been reordered to match the
314  * target table, and defaults have been filled in. Also, additional
315  * resjunk targets may be present. preprocess_targetlist() does most of
316  * that work, but note that more resjunk targets can get added during
317  * appendrel expansion. (Hence, upper_targets mustn't get set up till
318  * after that.)
319  */
321 
322  /*
323  * For UPDATE, this list contains the target table's attribute numbers to
324  * which the first N entries of processed_tlist are to be assigned. (Any
325  * additional entries in processed_tlist must be resjunk.) DO NOT use the
326  * resnos in processed_tlist to identify the UPDATE target columns.
327  */
329 
330  /* Fields filled during create_plan() for use in setrefs.c */
331  AttrNumber *grouping_map; /* for GroupingFunc fixup */
332  List *minmax_aggs; /* List of MinMaxAggInfos */
333 
334  MemoryContext planner_cxt; /* context holding PlannerInfo */
335 
336  double total_table_pages; /* # of pages in all non-dummy tables of
337  * query */
338 
339  double tuple_fraction; /* tuple_fraction passed to query_planner */
340  double limit_tuples; /* limit_tuples passed to query_planner */
341 
342  Index qual_security_level; /* minimum security_level for quals */
343  /* Note: qual_security_level is zero if there are no securityQuals */
344 
345  bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */
346  bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */
347  bool hasHavingQual; /* true if havingQual was non-null */
348  bool hasPseudoConstantQuals; /* true if any RestrictInfo has
349  * pseudoconstant = true */
350  bool hasAlternativeSubPlans; /* true if we've made any of those */
351  bool hasRecursion; /* true if planning a recursive WITH item */
352 
353  /*
354  * Information about aggregates. Filled by preprocess_aggrefs().
355  */
356  List *agginfos; /* AggInfo structs */
357  List *aggtransinfos; /* AggTransInfo structs */
358  int numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */
359  bool hasNonPartialAggs; /* does any agg not support partial mode? */
360  bool hasNonSerialAggs; /* is any partial agg non-serializable? */
361 
362  /* These fields are used only when hasRecursion is true: */
363  int wt_param_id; /* PARAM_EXEC ID for the work table */
364  struct Path *non_recursive_path; /* a path for non-recursive term */
365 
366  /* These fields are workspace for createplan.c */
367  Relids curOuterRels; /* outer rels above current node */
368  List *curOuterParams; /* not-yet-assigned NestLoopParams */
369 
370  /* optional private data for join_search_hook, e.g., GEQO */
372 
373  /* Does this query modify any partition key columns? */
375 };
376 
377 
378 /*
379  * In places where it's known that simple_rte_array[] must have been prepared
380  * already, we just index into it to fetch RTEs. In code that might be
381  * executed before or after entering query_planner(), use this macro.
382  */
383 #define planner_rt_fetch(rti, root) \
384  ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \
385  rt_fetch(rti, (root)->parse->rtable))
386 
387 /*
388  * If multiple relations are partitioned the same way, all such partitions
389  * will have a pointer to the same PartitionScheme. A list of PartitionScheme
390  * objects is attached to the PlannerInfo. By design, the partition scheme
391  * incorporates only the general properties of the partition method (LIST vs.
392  * RANGE, number of partitioning columns and the type information for each)
393  * and not the specific bounds.
394  *
395  * We store the opclass-declared input data types instead of the partition key
396  * datatypes since the former rather than the latter are used to compare
397  * partition bounds. Since partition key data types and the opclass declared
398  * input data types are expected to be binary compatible (per ResolveOpClass),
399  * both of those should have same byval and length properties.
400  */
401 typedef struct PartitionSchemeData
402 {
403  char strategy; /* partition strategy */
404  int16 partnatts; /* number of partition attributes */
405  Oid *partopfamily; /* OIDs of operator families */
406  Oid *partopcintype; /* OIDs of opclass declared input data types */
407  Oid *partcollation; /* OIDs of partitioning collations */
408 
409  /* Cached information about partition key data types. */
412 
413  /* Cached information about partition comparison functions. */
416 
418 
419 /*----------
420  * RelOptInfo
421  * Per-relation information for planning/optimization
422  *
423  * For planning purposes, a "base rel" is either a plain relation (a table)
424  * or the output of a sub-SELECT or function that appears in the range table.
425  * In either case it is uniquely identified by an RT index. A "joinrel"
426  * is the joining of two or more base rels. A joinrel is identified by
427  * the set of RT indexes for its component baserels. We create RelOptInfo
428  * nodes for each baserel and joinrel, and store them in the PlannerInfo's
429  * simple_rel_array and join_rel_list respectively.
430  *
431  * Note that there is only one joinrel for any given set of component
432  * baserels, no matter what order we assemble them in; so an unordered
433  * set is the right datatype to identify it with.
434  *
435  * We also have "other rels", which are like base rels in that they refer to
436  * single RT indexes; but they are not part of the join tree, and are given
437  * a different RelOptKind to identify them.
438  * Currently the only kind of otherrels are those made for member relations
439  * of an "append relation", that is an inheritance set or UNION ALL subquery.
440  * An append relation has a parent RTE that is a base rel, which represents
441  * the entire append relation. The member RTEs are otherrels. The parent
442  * is present in the query join tree but the members are not. The member
443  * RTEs and otherrels are used to plan the scans of the individual tables or
444  * subqueries of the append set; then the parent baserel is given Append
445  * and/or MergeAppend paths comprising the best paths for the individual
446  * member rels. (See comments for AppendRelInfo for more information.)
447  *
448  * At one time we also made otherrels to represent join RTEs, for use in
449  * handling join alias Vars. Currently this is not needed because all join
450  * alias Vars are expanded to non-aliased form during preprocess_expression.
451  *
452  * We also have relations representing joins between child relations of
453  * different partitioned tables. These relations are not added to
454  * join_rel_level lists as they are not joined directly by the dynamic
455  * programming algorithm.
456  *
457  * There is also a RelOptKind for "upper" relations, which are RelOptInfos
458  * that describe post-scan/join processing steps, such as aggregation.
459  * Many of the fields in these RelOptInfos are meaningless, but their Path
460  * fields always hold Paths showing ways to do that processing step.
461  *
462  * Lastly, there is a RelOptKind for "dead" relations, which are base rels
463  * that we have proven we don't need to join after all.
464  *
465  * Parts of this data structure are specific to various scan and join
466  * mechanisms. It didn't seem worth creating new node types for them.
467  *
468  * relids - Set of base-relation identifiers; it is a base relation
469  * if there is just one, a join relation if more than one
470  * rows - estimated number of tuples in the relation after restriction
471  * clauses have been applied (ie, output rows of a plan for it)
472  * consider_startup - true if there is any value in keeping plain paths for
473  * this rel on the basis of having cheap startup cost
474  * consider_param_startup - the same for parameterized paths
475  * reltarget - Default Path output tlist for this rel; normally contains
476  * Var and PlaceHolderVar nodes for the values we need to
477  * output from this relation.
478  * List is in no particular order, but all rels of an
479  * appendrel set must use corresponding orders.
480  * NOTE: in an appendrel child relation, may contain
481  * arbitrary expressions pulled up from a subquery!
482  * pathlist - List of Path nodes, one for each potentially useful
483  * method of generating the relation
484  * ppilist - ParamPathInfo nodes for parameterized Paths, if any
485  * cheapest_startup_path - the pathlist member with lowest startup cost
486  * (regardless of ordering) among the unparameterized paths;
487  * or NULL if there is no unparameterized path
488  * cheapest_total_path - the pathlist member with lowest total cost
489  * (regardless of ordering) among the unparameterized paths;
490  * or if there is no unparameterized path, the path with lowest
491  * total cost among the paths with minimum parameterization
492  * cheapest_unique_path - for caching cheapest path to produce unique
493  * (no duplicates) output from relation; NULL if not yet requested
494  * cheapest_parameterized_paths - best paths for their parameterizations;
495  * always includes cheapest_total_path, even if that's unparameterized
496  * direct_lateral_relids - rels this rel has direct LATERAL references to
497  * lateral_relids - required outer rels for LATERAL, as a Relids set
498  * (includes both direct and indirect lateral references)
499  *
500  * If the relation is a base relation it will have these fields set:
501  *
502  * relid - RTE index (this is redundant with the relids field, but
503  * is provided for convenience of access)
504  * rtekind - copy of RTE's rtekind field
505  * min_attr, max_attr - range of valid AttrNumbers for rel
506  * attr_needed - array of bitmapsets indicating the highest joinrel
507  * in which each attribute is needed; if bit 0 is set then
508  * the attribute is needed as part of final targetlist
509  * attr_widths - cache space for per-attribute width estimates;
510  * zero means not computed yet
511  * lateral_vars - lateral cross-references of rel, if any (list of
512  * Vars and PlaceHolderVars)
513  * lateral_referencers - relids of rels that reference this one laterally
514  * (includes both direct and indirect lateral references)
515  * indexlist - list of IndexOptInfo nodes for relation's indexes
516  * (always NIL if it's not a table)
517  * pages - number of disk pages in relation (zero if not a table)
518  * tuples - number of tuples in relation (not considering restrictions)
519  * allvisfrac - fraction of disk pages that are marked all-visible
520  * eclass_indexes - EquivalenceClasses that mention this rel (filled
521  * only after EC merging is complete)
522  * subroot - PlannerInfo for subquery (NULL if it's not a subquery)
523  * subplan_params - list of PlannerParamItems to be passed to subquery
524  *
525  * Note: for a subquery, tuples and subroot are not set immediately
526  * upon creation of the RelOptInfo object; they are filled in when
527  * set_subquery_pathlist processes the object.
528  *
529  * For otherrels that are appendrel members, these fields are filled
530  * in just as for a baserel, except we don't bother with lateral_vars.
531  *
532  * If the relation is either a foreign table or a join of foreign tables that
533  * all belong to the same foreign server and are assigned to the same user to
534  * check access permissions as (cf checkAsUser), these fields will be set:
535  *
536  * serverid - OID of foreign server, if foreign table (else InvalidOid)
537  * userid - OID of user to check access as (InvalidOid means current user)
538  * useridiscurrent - we've assumed that userid equals current user
539  * fdwroutine - function hooks for FDW, if foreign table (else NULL)
540  * fdw_private - private state for FDW, if foreign table (else NULL)
541  *
542  * Two fields are used to cache knowledge acquired during the join search
543  * about whether this rel is provably unique when being joined to given other
544  * relation(s), ie, it can have at most one row matching any given row from
545  * that join relation. Currently we only attempt such proofs, and thus only
546  * populate these fields, for base rels; but someday they might be used for
547  * join rels too:
548  *
549  * unique_for_rels - list of Relid sets, each one being a set of other
550  * rels for which this one has been proven unique
551  * non_unique_for_rels - list of Relid sets, each one being a set of
552  * other rels for which we have tried and failed to prove
553  * this one unique
554  *
555  * The presence of the following fields depends on the restrictions
556  * and joins that the relation participates in:
557  *
558  * baserestrictinfo - List of RestrictInfo nodes, containing info about
559  * each non-join qualification clause in which this relation
560  * participates (only used for base rels)
561  * baserestrictcost - Estimated cost of evaluating the baserestrictinfo
562  * clauses at a single tuple (only used for base rels)
563  * baserestrict_min_security - Smallest security_level found among
564  * clauses in baserestrictinfo
565  * joininfo - List of RestrictInfo nodes, containing info about each
566  * join clause in which this relation participates (but
567  * note this excludes clauses that might be derivable from
568  * EquivalenceClasses)
569  * has_eclass_joins - flag that EquivalenceClass joins are possible
570  *
571  * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for
572  * base rels, because for a join rel the set of clauses that are treated as
573  * restrict clauses varies depending on which sub-relations we choose to join.
574  * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be
575  * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but
576  * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2}
577  * and should not be processed again at the level of {1 2 3}.) Therefore,
578  * the restrictinfo list in the join case appears in individual JoinPaths
579  * (field joinrestrictinfo), not in the parent relation. But it's OK for
580  * the RelOptInfo to store the joininfo list, because that is the same
581  * for a given rel no matter how we form it.
582  *
583  * We store baserestrictcost in the RelOptInfo (for base relations) because
584  * we know we will need it at least once (to price the sequential scan)
585  * and may need it multiple times to price index scans.
586  *
587  * A join relation is considered to be partitioned if it is formed from a
588  * join of two relations that are partitioned, have matching partitioning
589  * schemes, and are joined on an equijoin of the partitioning columns.
590  * Under those conditions we can consider the join relation to be partitioned
591  * by either relation's partitioning keys, though some care is needed if
592  * either relation can be forced to null by outer-joining. For example, an
593  * outer join like (A LEFT JOIN B ON A.a = B.b) may produce rows with B.b
594  * NULL. These rows may not fit the partitioning conditions imposed on B.
595  * Hence, strictly speaking, the join is not partitioned by B.b and thus
596  * partition keys of an outer join should include partition key expressions
597  * from the non-nullable side only. However, if a subsequent join uses
598  * strict comparison operators (and all commonly-used equijoin operators are
599  * strict), the presence of nulls doesn't cause a problem: such rows couldn't
600  * match anything on the other side and thus they don't create a need to do
601  * any cross-partition sub-joins. Hence we can treat such values as still
602  * partitioning the join output for the purpose of additional partitionwise
603  * joining, so long as a strict join operator is used by the next join.
604  *
605  * If the relation is partitioned, these fields will be set:
606  *
607  * part_scheme - Partitioning scheme of the relation
608  * nparts - Number of partitions
609  * boundinfo - Partition bounds
610  * partbounds_merged - true if partition bounds are merged ones
611  * partition_qual - Partition constraint if not the root
612  * part_rels - RelOptInfos for each partition
613  * all_partrels - Relids set of all partition relids
614  * partexprs, nullable_partexprs - Partition key expressions
615  *
616  * The partexprs and nullable_partexprs arrays each contain
617  * part_scheme->partnatts elements. Each of the elements is a list of
618  * partition key expressions. For partitioned base relations, there is one
619  * expression in each partexprs element, and nullable_partexprs is empty.
620  * For partitioned join relations, each base relation within the join
621  * contributes one partition key expression per partitioning column;
622  * that expression goes in the partexprs[i] list if the base relation
623  * is not nullable by this join or any lower outer join, or in the
624  * nullable_partexprs[i] list if the base relation is nullable.
625  * Furthermore, FULL JOINs add extra nullable_partexprs expressions
626  * corresponding to COALESCE expressions of the left and right join columns,
627  * to simplify matching join clauses to those lists.
628  *----------
629  */
630 
631 /* Bitmask of flags supported by table AMs */
632 #define AMFLAG_HAS_TID_RANGE (1 << 0)
633 
634 typedef enum RelOptKind
635 {
643 } RelOptKind;
644 
645 /*
646  * Is the given relation a simple relation i.e a base or "other" member
647  * relation?
648  */
649 #define IS_SIMPLE_REL(rel) \
650  ((rel)->reloptkind == RELOPT_BASEREL || \
651  (rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
652 
653 /* Is the given relation a join relation? */
654 #define IS_JOIN_REL(rel) \
655  ((rel)->reloptkind == RELOPT_JOINREL || \
656  (rel)->reloptkind == RELOPT_OTHER_JOINREL)
657 
658 /* Is the given relation an upper relation? */
659 #define IS_UPPER_REL(rel) \
660  ((rel)->reloptkind == RELOPT_UPPER_REL || \
661  (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
662 
663 /* Is the given relation an "other" relation? */
664 #define IS_OTHER_REL(rel) \
665  ((rel)->reloptkind == RELOPT_OTHER_MEMBER_REL || \
666  (rel)->reloptkind == RELOPT_OTHER_JOINREL || \
667  (rel)->reloptkind == RELOPT_OTHER_UPPER_REL)
668 
669 typedef struct RelOptInfo
670 {
672 
674 
675  /* all relations included in this RelOptInfo */
676  Relids relids; /* set of base relids (rangetable indexes) */
677 
678  /* size estimates generated by planner */
679  double rows; /* estimated number of result tuples */
680 
681  /* per-relation planner control flags */
682  bool consider_startup; /* keep cheap-startup-cost paths? */
683  bool consider_param_startup; /* ditto, for parameterized paths? */
684  bool consider_parallel; /* consider parallel paths? */
685 
686  /* default result targetlist for Paths scanning this relation */
687  struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
688 
689  /* materialization information */
690  List *pathlist; /* Path structures */
691  List *ppilist; /* ParamPathInfos used in pathlist */
692  List *partial_pathlist; /* partial Paths */
697 
698  /* parameterization information needed for both base rels and join rels */
699  /* (see also lateral_vars and lateral_referencers) */
700  Relids direct_lateral_relids; /* rels directly laterally referenced */
701  Relids lateral_relids; /* minimum parameterization of rel */
702 
703  /* information about a base rel (not set for join rels!) */
705  Oid reltablespace; /* containing tablespace */
706  RTEKind rtekind; /* RELATION, SUBQUERY, FUNCTION, etc */
707  AttrNumber min_attr; /* smallest attrno of rel (often <0) */
708  AttrNumber max_attr; /* largest attrno of rel */
709  Relids *attr_needed; /* array indexed [min_attr .. max_attr] */
710  int32 *attr_widths; /* array indexed [min_attr .. max_attr] */
711  List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */
712  Relids lateral_referencers; /* rels that reference me laterally */
713  List *indexlist; /* list of IndexOptInfo */
714  List *statlist; /* list of StatisticExtInfo */
715  BlockNumber pages; /* size estimates derived from pg_class */
716  double tuples;
717  double allvisfrac;
718  Bitmapset *eclass_indexes; /* Indexes in PlannerInfo's eq_classes list of
719  * ECs that mention this rel */
720  PlannerInfo *subroot; /* if subquery */
721  List *subplan_params; /* if subquery */
722  int rel_parallel_workers; /* wanted number of parallel workers */
723  uint32 amflags; /* Bitmask of optional features supported by
724  * the table AM */
725 
726  /* Information about foreign tables and foreign joins */
727  Oid serverid; /* identifies server for the table or join */
728  Oid userid; /* identifies user to check access as */
729  bool useridiscurrent; /* join is only valid for current user */
730  /* use "struct FdwRoutine" to avoid including fdwapi.h here */
732  void *fdw_private;
733 
734  /* cache space for remembering if we have proven this relation unique */
735  List *unique_for_rels; /* known unique for these other relid
736  * set(s) */
737  List *non_unique_for_rels; /* known not unique for these set(s) */
738 
739  /* used by various scans and joins: */
740  List *baserestrictinfo; /* RestrictInfo structures (if base rel) */
741  QualCost baserestrictcost; /* cost of evaluating the above */
742  Index baserestrict_min_security; /* min security_level found in
743  * baserestrictinfo */
744  List *joininfo; /* RestrictInfo structures for join clauses
745  * involving this rel */
746  bool has_eclass_joins; /* T means joininfo is incomplete */
747 
748  /* used by partitionwise joins: */
749  bool consider_partitionwise_join; /* consider partitionwise join
750  * paths? (if partitioned rel) */
751  Relids top_parent_relids; /* Relids of topmost parents (if "other"
752  * rel) */
753 
754  /* used for partitioned relations: */
755  PartitionScheme part_scheme; /* Partitioning scheme */
756  int nparts; /* Number of partitions; -1 if not yet set; in
757  * case of a join relation 0 means it's
758  * considered unpartitioned */
759  struct PartitionBoundInfoData *boundinfo; /* Partition bounds */
760  bool partbounds_merged; /* True if partition bounds were created
761  * by partition_bounds_merge() */
762  List *partition_qual; /* Partition constraint, if not the root */
763  struct RelOptInfo **part_rels; /* Array of RelOptInfos of partitions,
764  * stored in the same order as bounds */
765  Relids all_partrels; /* Relids set of all partition relids */
766  List **partexprs; /* Non-nullable partition key expressions */
767  List **nullable_partexprs; /* Nullable partition key expressions */
768 } RelOptInfo;
769 
770 /*
771  * Is given relation partitioned?
772  *
773  * It's not enough to test whether rel->part_scheme is set, because it might
774  * be that the basic partitioning properties of the input relations matched
775  * but the partition bounds did not. Also, if we are able to prove a rel
776  * dummy (empty), we should henceforth treat it as unpartitioned.
777  */
778 #define IS_PARTITIONED_REL(rel) \
779  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
780  (rel)->part_rels && !IS_DUMMY_REL(rel))
781 
782 /*
783  * Convenience macro to make sure that a partitioned relation has all the
784  * required members set.
785  */
786 #define REL_HAS_ALL_PART_PROPS(rel) \
787  ((rel)->part_scheme && (rel)->boundinfo && (rel)->nparts > 0 && \
788  (rel)->part_rels && (rel)->partexprs && (rel)->nullable_partexprs)
789 
790 /*
791  * IndexOptInfo
792  * Per-index information for planning/optimization
793  *
794  * indexkeys[], indexcollations[] each have ncolumns entries.
795  * opfamily[], and opcintype[] each have nkeycolumns entries. They do
796  * not contain any information about included attributes.
797  *
798  * sortopfamily[], reverse_sort[], and nulls_first[] have
799  * nkeycolumns entries, if the index is ordered; but if it is unordered,
800  * those pointers are NULL.
801  *
802  * Zeroes in the indexkeys[] array indicate index columns that are
803  * expressions; there is one element in indexprs for each such column.
804  *
805  * For an ordered index, reverse_sort[] and nulls_first[] describe the
806  * sort ordering of a forward indexscan; we can also consider a backward
807  * indexscan, which will generate the reverse ordering.
808  *
809  * The indexprs and indpred expressions have been run through
810  * prepqual.c and eval_const_expressions() for ease of matching to
811  * WHERE clauses. indpred is in implicit-AND form.
812  *
813  * indextlist is a TargetEntry list representing the index columns.
814  * It provides an equivalent base-relation Var for each simple column,
815  * and links to the matching indexprs element for each expression column.
816  *
817  * While most of these fields are filled when the IndexOptInfo is created
818  * (by plancat.c), indrestrictinfo and predOK are set later, in
819  * check_index_predicates().
820  */
821 #ifndef HAVE_INDEXOPTINFO_TYPEDEF
822 typedef struct IndexOptInfo IndexOptInfo;
823 #define HAVE_INDEXOPTINFO_TYPEDEF 1
824 #endif
825 
827 {
829 
830  Oid indexoid; /* OID of the index relation */
831  Oid reltablespace; /* tablespace of index (not table) */
832  RelOptInfo *rel; /* back-link to index's table */
833 
834  /* index-size statistics (from pg_class and elsewhere) */
835  BlockNumber pages; /* number of disk pages in index */
836  double tuples; /* number of index tuples in index */
837  int tree_height; /* index tree height, or -1 if unknown */
838 
839  /* index descriptor information */
840  int ncolumns; /* number of columns in index */
841  int nkeycolumns; /* number of key columns in index */
842  int *indexkeys; /* column numbers of index's attributes both
843  * key and included columns, or 0 */
844  Oid *indexcollations; /* OIDs of collations of index columns */
845  Oid *opfamily; /* OIDs of operator families for columns */
846  Oid *opcintype; /* OIDs of opclass declared input data types */
847  Oid *sortopfamily; /* OIDs of btree opfamilies, if orderable */
848  bool *reverse_sort; /* is sort order descending? */
849  bool *nulls_first; /* do NULLs come first in the sort order? */
850  bytea **opclassoptions; /* opclass-specific options for columns */
851  bool *canreturn; /* which index cols can be returned in an
852  * index-only scan? */
853  Oid relam; /* OID of the access method (in pg_am) */
854 
855  List *indexprs; /* expressions for non-simple index columns */
856  List *indpred; /* predicate if a partial index, else NIL */
857 
858  List *indextlist; /* targetlist representing index columns */
859 
860  List *indrestrictinfo; /* parent relation's baserestrictinfo
861  * list, less any conditions implied by
862  * the index's predicate (unless it's a
863  * target rel, see comments in
864  * check_index_predicates()) */
865 
866  bool predOK; /* true if index predicate matches query */
867  bool unique; /* true if a unique index */
868  bool immediate; /* is uniqueness enforced immediately? */
869  bool hypothetical; /* true if index doesn't really exist */
870 
871  /* Remaining fields are copied from the index AM's API struct: */
872  bool amcanorderbyop; /* does AM support order by operator result? */
873  bool amoptionalkey; /* can query omit key for the first column? */
874  bool amsearcharray; /* can AM handle ScalarArrayOpExpr quals? */
875  bool amsearchnulls; /* can AM search for NULL/NOT NULL entries? */
876  bool amhasgettuple; /* does AM have amgettuple interface? */
877  bool amhasgetbitmap; /* does AM have amgetbitmap interface? */
878  bool amcanparallel; /* does AM support parallel scan? */
879  bool amcanmarkpos; /* does AM support mark/restore? */
880  /* Rather than include amapi.h here, we declare amcostestimate like this */
881  void (*amcostestimate) (); /* AM's cost estimator */
882 };
883 
884 /*
885  * ForeignKeyOptInfo
886  * Per-foreign-key information for planning/optimization
887  *
888  * The per-FK-column arrays can be fixed-size because we allow at most
889  * INDEX_MAX_KEYS columns in a foreign key constraint. Each array has
890  * nkeys valid entries.
891  */
892 typedef struct ForeignKeyOptInfo
893 {
895 
896  /* Basic data about the foreign key (fetched from catalogs): */
897  Index con_relid; /* RT index of the referencing table */
898  Index ref_relid; /* RT index of the referenced table */
899  int nkeys; /* number of columns in the foreign key */
900  AttrNumber conkey[INDEX_MAX_KEYS]; /* cols in referencing table */
901  AttrNumber confkey[INDEX_MAX_KEYS]; /* cols in referenced table */
902  Oid conpfeqop[INDEX_MAX_KEYS]; /* PK = FK operator OIDs */
903 
904  /* Derived info about whether FK's equality conditions match the query: */
905  int nmatched_ec; /* # of FK cols matched by ECs */
906  int nconst_ec; /* # of these ECs that are ec_has_const */
907  int nmatched_rcols; /* # of FK cols matched by non-EC rinfos */
908  int nmatched_ri; /* total # of non-EC rinfos matched to FK */
909  /* Pointer to eclass matching each column's condition, if there is one */
911  /* Pointer to eclass member for the referencing Var, if there is one */
912  struct EquivalenceMember *fk_eclass_member[INDEX_MAX_KEYS];
913  /* List of non-EC RestrictInfos matching each column's condition */
916 
917 /*
918  * StatisticExtInfo
919  * Information about extended statistics for planning/optimization
920  *
921  * Each pg_statistic_ext row is represented by one or more nodes of this
922  * type, or even zero if ANALYZE has not computed them.
923  */
924 typedef struct StatisticExtInfo
925 {
927 
928  Oid statOid; /* OID of the statistics row */
929  RelOptInfo *rel; /* back-link to statistic's table */
930  char kind; /* statistics kind of this entry */
931  Bitmapset *keys; /* attnums of the columns covered */
932  List *exprs; /* expressions */
934 
935 /*
936  * EquivalenceClasses
937  *
938  * Whenever we can determine that a mergejoinable equality clause A = B is
939  * not delayed by any outer join, we create an EquivalenceClass containing
940  * the expressions A and B to record this knowledge. If we later find another
941  * equivalence B = C, we add C to the existing EquivalenceClass; this may
942  * require merging two existing EquivalenceClasses. At the end of the qual
943  * distribution process, we have sets of values that are known all transitively
944  * equal to each other, where "equal" is according to the rules of the btree
945  * operator family(s) shown in ec_opfamilies, as well as the collation shown
946  * by ec_collation. (We restrict an EC to contain only equalities whose
947  * operators belong to the same set of opfamilies. This could probably be
948  * relaxed, but for now it's not worth the trouble, since nearly all equality
949  * operators belong to only one btree opclass anyway. Similarly, we suppose
950  * that all or none of the input datatypes are collatable, so that a single
951  * collation value is sufficient.)
952  *
953  * We also use EquivalenceClasses as the base structure for PathKeys, letting
954  * us represent knowledge about different sort orderings being equivalent.
955  * Since every PathKey must reference an EquivalenceClass, we will end up
956  * with single-member EquivalenceClasses whenever a sort key expression has
957  * not been equivalenced to anything else. It is also possible that such an
958  * EquivalenceClass will contain a volatile expression ("ORDER BY random()"),
959  * which is a case that can't arise otherwise since clauses containing
960  * volatile functions are never considered mergejoinable. We mark such
961  * EquivalenceClasses specially to prevent them from being merged with
962  * ordinary EquivalenceClasses. Also, for volatile expressions we have
963  * to be careful to match the EquivalenceClass to the correct targetlist
964  * entry: consider SELECT random() AS a, random() AS b ... ORDER BY b,a.
965  * So we record the SortGroupRef of the originating sort clause.
966  *
967  * We allow equality clauses appearing below the nullable side of an outer join
968  * to form EquivalenceClasses, but these have a slightly different meaning:
969  * the included values might be all NULL rather than all the same non-null
970  * values. See src/backend/optimizer/README for more on that point.
971  *
972  * NB: if ec_merged isn't NULL, this class has been merged into another, and
973  * should be ignored in favor of using the pointed-to class.
974  */
975 typedef struct EquivalenceClass
976 {
978 
979  List *ec_opfamilies; /* btree operator family OIDs */
980  Oid ec_collation; /* collation, if datatypes are collatable */
981  List *ec_members; /* list of EquivalenceMembers */
982  List *ec_sources; /* list of generating RestrictInfos */
983  List *ec_derives; /* list of derived RestrictInfos */
984  Relids ec_relids; /* all relids appearing in ec_members, except
985  * for child members (see below) */
986  bool ec_has_const; /* any pseudoconstants in ec_members? */
987  bool ec_has_volatile; /* the (sole) member is a volatile expr */
988  bool ec_below_outer_join; /* equivalence applies below an OJ */
989  bool ec_broken; /* failed to generate needed clauses? */
990  Index ec_sortref; /* originating sortclause label, or 0 */
991  Index ec_min_security; /* minimum security_level in ec_sources */
992  Index ec_max_security; /* maximum security_level in ec_sources */
993  struct EquivalenceClass *ec_merged; /* set if merged into another EC */
995 
996 /*
997  * If an EC contains a const and isn't below-outer-join, any PathKey depending
998  * on it must be redundant, since there's only one possible value of the key.
999  */
1000 #define EC_MUST_BE_REDUNDANT(eclass) \
1001  ((eclass)->ec_has_const && !(eclass)->ec_below_outer_join)
1002 
1003 /*
1004  * EquivalenceMember - one member expression of an EquivalenceClass
1005  *
1006  * em_is_child signifies that this element was built by transposing a member
1007  * for an appendrel parent relation to represent the corresponding expression
1008  * for an appendrel child. These members are used for determining the
1009  * pathkeys of scans on the child relation and for explicitly sorting the
1010  * child when necessary to build a MergeAppend path for the whole appendrel
1011  * tree. An em_is_child member has no impact on the properties of the EC as a
1012  * whole; in particular the EC's ec_relids field does NOT include the child
1013  * relation. An em_is_child member should never be marked em_is_const nor
1014  * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child
1015  * members are not really full-fledged members of the EC, but just reflections
1016  * or doppelgangers of real members. Most operations on EquivalenceClasses
1017  * should ignore em_is_child members, and those that don't should test
1018  * em_relids to make sure they only consider relevant members.
1019  *
1020  * em_datatype is usually the same as exprType(em_expr), but can be
1021  * different when dealing with a binary-compatible opfamily; in particular
1022  * anyarray_ops would never work without this. Use em_datatype when
1023  * looking up a specific btree operator to work with this expression.
1024  */
1025 typedef struct EquivalenceMember
1026 {
1028 
1029  Expr *em_expr; /* the expression represented */
1030  Relids em_relids; /* all relids appearing in em_expr */
1031  Relids em_nullable_relids; /* nullable by lower outer joins */
1032  bool em_is_const; /* expression is pseudoconstant? */
1033  bool em_is_child; /* derived version for a child relation? */
1034  Oid em_datatype; /* the "nominal type" used by the opfamily */
1036 
1037 /*
1038  * PathKeys
1039  *
1040  * The sort ordering of a path is represented by a list of PathKey nodes.
1041  * An empty list implies no known ordering. Otherwise the first item
1042  * represents the primary sort key, the second the first secondary sort key,
1043  * etc. The value being sorted is represented by linking to an
1044  * EquivalenceClass containing that value and including pk_opfamily among its
1045  * ec_opfamilies. The EquivalenceClass tells which collation to use, too.
1046  * This is a convenient method because it makes it trivial to detect
1047  * equivalent and closely-related orderings. (See optimizer/README for more
1048  * information.)
1049  *
1050  * Note: pk_strategy is either BTLessStrategyNumber (for ASC) or
1051  * BTGreaterStrategyNumber (for DESC). We assume that all ordering-capable
1052  * index types will use btree-compatible strategy numbers.
1053  */
1054 typedef struct PathKey
1055 {
1057 
1058  EquivalenceClass *pk_eclass; /* the value that is ordered */
1059  Oid pk_opfamily; /* btree opfamily defining the ordering */
1060  int pk_strategy; /* sort direction (ASC or DESC) */
1061  bool pk_nulls_first; /* do NULLs come before normal values? */
1062 } PathKey;
1063 
1064 /*
1065  * VolatileFunctionStatus -- allows nodes to cache their
1066  * contain_volatile_functions properties. VOLATILITY_UNKNOWN means not yet
1067  * determined.
1068  */
1070 {
1075 
1076 /*
1077  * PathTarget
1078  *
1079  * This struct contains what we need to know during planning about the
1080  * targetlist (output columns) that a Path will compute. Each RelOptInfo
1081  * includes a default PathTarget, which its individual Paths may simply
1082  * reference. However, in some cases a Path may compute outputs different
1083  * from other Paths, and in that case we make a custom PathTarget for it.
1084  * For example, an indexscan might return index expressions that would
1085  * otherwise need to be explicitly calculated. (Note also that "upper"
1086  * relations generally don't have useful default PathTargets.)
1087  *
1088  * exprs contains bare expressions; they do not have TargetEntry nodes on top,
1089  * though those will appear in finished Plans.
1090  *
1091  * sortgrouprefs[] is an array of the same length as exprs, containing the
1092  * corresponding sort/group refnos, or zeroes for expressions not referenced
1093  * by sort/group clauses. If sortgrouprefs is NULL (which it generally is in
1094  * RelOptInfo.reltarget targets; only upper-level Paths contain this info),
1095  * we have not identified sort/group columns in this tlist. This allows us to
1096  * deal with sort/group refnos when needed with less expense than including
1097  * TargetEntry nodes in the exprs list.
1098  */
1099 typedef struct PathTarget
1100 {
1102  List *exprs; /* list of expressions to be computed */
1103  Index *sortgrouprefs; /* corresponding sort/group refnos, or 0 */
1104  QualCost cost; /* cost of evaluating the expressions */
1105  int width; /* estimated avg width of result tuples */
1106  VolatileFunctionStatus has_volatile_expr; /* indicates if exprs contain
1107  * any volatile functions. */
1108 } PathTarget;
1109 
1110 /* Convenience macro to get a sort/group refno from a PathTarget */
1111 #define get_pathtarget_sortgroupref(target, colno) \
1112  ((target)->sortgrouprefs ? (target)->sortgrouprefs[colno] : (Index) 0)
1113 
1114 
1115 /*
1116  * ParamPathInfo
1117  *
1118  * All parameterized paths for a given relation with given required outer rels
1119  * link to a single ParamPathInfo, which stores common information such as
1120  * the estimated rowcount for this parameterization. We do this partly to
1121  * avoid recalculations, but mostly to ensure that the estimated rowcount
1122  * is in fact the same for every such path.
1123  *
1124  * Note: ppi_clauses is only used in ParamPathInfos for base relation paths;
1125  * in join cases it's NIL because the set of relevant clauses varies depending
1126  * on how the join is formed. The relevant clauses will appear in each
1127  * parameterized join path's joinrestrictinfo list, instead.
1128  */
1129 typedef struct ParamPathInfo
1130 {
1132 
1133  Relids ppi_req_outer; /* rels supplying parameters used by path */
1134  double ppi_rows; /* estimated number of result tuples */
1135  List *ppi_clauses; /* join clauses available from outer rels */
1136 } ParamPathInfo;
1137 
1138 
1139 /*
1140  * Type "Path" is used as-is for sequential-scan paths, as well as some other
1141  * simple plan types that we don't need any extra information in the path for.
1142  * For other path types it is the first component of a larger struct.
1143  *
1144  * "pathtype" is the NodeTag of the Plan node we could build from this Path.
1145  * It is partially redundant with the Path's NodeTag, but allows us to use
1146  * the same Path type for multiple Plan types when there is no need to
1147  * distinguish the Plan type during path processing.
1148  *
1149  * "parent" identifies the relation this Path scans, and "pathtarget"
1150  * describes the precise set of output columns the Path would compute.
1151  * In simple cases all Paths for a given rel share the same targetlist,
1152  * which we represent by having path->pathtarget equal to parent->reltarget.
1153  *
1154  * "param_info", if not NULL, links to a ParamPathInfo that identifies outer
1155  * relation(s) that provide parameter values to each scan of this path.
1156  * That means this path can only be joined to those rels by means of nestloop
1157  * joins with this path on the inside. Also note that a parameterized path
1158  * is responsible for testing all "movable" joinclauses involving this rel
1159  * and the specified outer rel(s).
1160  *
1161  * "rows" is the same as parent->rows in simple paths, but in parameterized
1162  * paths and UniquePaths it can be less than parent->rows, reflecting the
1163  * fact that we've filtered by extra join conditions or removed duplicates.
1164  *
1165  * "pathkeys" is a List of PathKey nodes (see above), describing the sort
1166  * ordering of the path's output rows.
1167  */
1168 typedef struct Path
1169 {
1171 
1172  NodeTag pathtype; /* tag identifying scan/join method */
1173 
1174  RelOptInfo *parent; /* the relation this path can build */
1175  PathTarget *pathtarget; /* list of Vars/Exprs, cost, width */
1176 
1177  ParamPathInfo *param_info; /* parameterization info, or NULL if none */
1178 
1179  bool parallel_aware; /* engage parallel-aware logic? */
1180  bool parallel_safe; /* OK to use as part of parallel plan? */
1181  int parallel_workers; /* desired # of workers; 0 = not parallel */
1182 
1183  /* estimated size/costs for path (see costsize.c for more info) */
1184  double rows; /* estimated number of result tuples */
1185  Cost startup_cost; /* cost expended before fetching any tuples */
1186  Cost total_cost; /* total cost (assuming all tuples fetched) */
1187 
1188  List *pathkeys; /* sort ordering of path's output */
1189  /* pathkeys is a List of PathKey nodes; see above */
1190 } Path;
1191 
1192 /* Macro for extracting a path's parameterization relids; beware double eval */
1193 #define PATH_REQ_OUTER(path) \
1194  ((path)->param_info ? (path)->param_info->ppi_req_outer : (Relids) NULL)
1195 
1196 /*----------
1197  * IndexPath represents an index scan over a single index.
1198  *
1199  * This struct is used for both regular indexscans and index-only scans;
1200  * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
1201  *
1202  * 'indexinfo' is the index to be scanned.
1203  *
1204  * 'indexclauses' is a list of IndexClause nodes, each representing one
1205  * index-checkable restriction, with implicit AND semantics across the list.
1206  * An empty list implies a full index scan.
1207  *
1208  * 'indexorderbys', if not NIL, is a list of ORDER BY expressions that have
1209  * been found to be usable as ordering operators for an amcanorderbyop index.
1210  * The list must match the path's pathkeys, ie, one expression per pathkey
1211  * in the same order. These are not RestrictInfos, just bare expressions,
1212  * since they generally won't yield booleans. It's guaranteed that each
1213  * expression has the index key on the left side of the operator.
1214  *
1215  * 'indexorderbycols' is an integer list of index column numbers (zero-based)
1216  * of the same length as 'indexorderbys', showing which index column each
1217  * ORDER BY expression is meant to be used with. (There is no restriction
1218  * on which index column each ORDER BY can be used with.)
1219  *
1220  * 'indexscandir' is one of:
1221  * ForwardScanDirection: forward scan of an ordered index
1222  * BackwardScanDirection: backward scan of an ordered index
1223  * NoMovementScanDirection: scan of an unordered index, or don't care
1224  * (The executor doesn't care whether it gets ForwardScanDirection or
1225  * NoMovementScanDirection for an indexscan, but the planner wants to
1226  * distinguish ordered from unordered indexes for building pathkeys.)
1227  *
1228  * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
1229  * we need not recompute them when considering using the same index in a
1230  * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
1231  * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
1232  *----------
1233  */
1234 typedef struct IndexPath
1235 {
1244 } IndexPath;
1245 
1246 /*
1247  * Each IndexClause references a RestrictInfo node from the query's WHERE
1248  * or JOIN conditions, and shows how that restriction can be applied to
1249  * the particular index. We support both indexclauses that are directly
1250  * usable by the index machinery, which are typically of the form
1251  * "indexcol OP pseudoconstant", and those from which an indexable qual
1252  * can be derived. The simplest such transformation is that a clause
1253  * of the form "pseudoconstant OP indexcol" can be commuted to produce an
1254  * indexable qual (the index machinery expects the indexcol to be on the
1255  * left always). Another example is that we might be able to extract an
1256  * indexable range condition from a LIKE condition, as in "x LIKE 'foo%bar'"
1257  * giving rise to "x >= 'foo' AND x < 'fop'". Derivation of such lossy
1258  * conditions is done by a planner support function attached to the
1259  * indexclause's top-level function or operator.
1260  *
1261  * indexquals is a list of RestrictInfos for the directly-usable index
1262  * conditions associated with this IndexClause. In the simplest case
1263  * it's a one-element list whose member is iclause->rinfo. Otherwise,
1264  * it contains one or more directly-usable indexqual conditions extracted
1265  * from the given clause. The 'lossy' flag indicates whether the
1266  * indexquals are semantically equivalent to the original clause, or
1267  * represent a weaker condition.
1268  *
1269  * Normally, indexcol is the index of the single index column the clause
1270  * works on, and indexcols is NIL. But if the clause is a RowCompareExpr,
1271  * indexcol is the index of the leading column, and indexcols is a list of
1272  * all the affected columns. (Note that indexcols matches up with the
1273  * columns of the actual indexable RowCompareExpr in indexquals, which
1274  * might be different from the original in rinfo.)
1275  *
1276  * An IndexPath's IndexClause list is required to be ordered by index
1277  * column, i.e. the indexcol values must form a nondecreasing sequence.
1278  * (The order of multiple clauses for the same index column is unspecified.)
1279  */
1280 typedef struct IndexClause
1281 {
1283  struct RestrictInfo *rinfo; /* original restriction or join clause */
1284  List *indexquals; /* indexqual(s) derived from it */
1285  bool lossy; /* are indexquals a lossy version of clause? */
1286  AttrNumber indexcol; /* index column the clause uses (zero-based) */
1287  List *indexcols; /* multiple index columns, if RowCompare */
1288 } IndexClause;
1289 
1290 /*
1291  * BitmapHeapPath represents one or more indexscans that generate TID bitmaps
1292  * instead of directly accessing the heap, followed by AND/OR combinations
1293  * to produce a single bitmap, followed by a heap scan that uses the bitmap.
1294  * Note that the output is always considered unordered, since it will come
1295  * out in physical heap order no matter what the underlying indexes did.
1296  *
1297  * The individual indexscans are represented by IndexPath nodes, and any
1298  * logic on top of them is represented by a tree of BitmapAndPath and
1299  * BitmapOrPath nodes. Notice that we can use the same IndexPath node both
1300  * to represent a regular (or index-only) index scan plan, and as the child
1301  * of a BitmapHeapPath that represents scanning the same index using a
1302  * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
1303  * always represent the costs to use it as a regular (or index-only)
1304  * IndexScan. The costs of a BitmapIndexScan can be computed using the
1305  * IndexPath's indextotalcost and indexselectivity.
1306  */
1307 typedef struct BitmapHeapPath
1308 {
1310  Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */
1311 } BitmapHeapPath;
1312 
1313 /*
1314  * BitmapAndPath represents a BitmapAnd plan node; it can only appear as
1315  * part of the substructure of a BitmapHeapPath. The Path structure is
1316  * a bit more heavyweight than we really need for this, but for simplicity
1317  * we make it a derivative of Path anyway.
1318  */
1319 typedef struct BitmapAndPath
1320 {
1322  List *bitmapquals; /* IndexPaths and BitmapOrPaths */
1324 } BitmapAndPath;
1325 
1326 /*
1327  * BitmapOrPath represents a BitmapOr plan node; it can only appear as
1328  * part of the substructure of a BitmapHeapPath. The Path structure is
1329  * a bit more heavyweight than we really need for this, but for simplicity
1330  * we make it a derivative of Path anyway.
1331  */
1332 typedef struct BitmapOrPath
1333 {
1335  List *bitmapquals; /* IndexPaths and BitmapAndPaths */
1337 } BitmapOrPath;
1338 
1339 /*
1340  * TidPath represents a scan by TID
1341  *
1342  * tidquals is an implicitly OR'ed list of qual expressions of the form
1343  * "CTID = pseudoconstant", or "CTID = ANY(pseudoconstant_array)",
1344  * or a CurrentOfExpr for the relation.
1345  */
1346 typedef struct TidPath
1347 {
1349  List *tidquals; /* qual(s) involving CTID = something */
1350 } TidPath;
1351 
1352 /*
1353  * TidRangePath represents a scan by a continguous range of TIDs
1354  *
1355  * tidrangequals is an implicitly AND'ed list of qual expressions of the form
1356  * "CTID relop pseudoconstant", where relop is one of >,>=,<,<=.
1357  */
1358 typedef struct TidRangePath
1359 {
1362 } TidRangePath;
1363 
1364 /*
1365  * SubqueryScanPath represents a scan of an unflattened subquery-in-FROM
1366  *
1367  * Note that the subpath comes from a different planning domain; for example
1368  * RTE indexes within it mean something different from those known to the
1369  * SubqueryScanPath. path.parent->subroot is the planning context needed to
1370  * interpret the subpath.
1371  */
1372 typedef struct SubqueryScanPath
1373 {
1375  Path *subpath; /* path representing subquery execution */
1377 
1378 /*
1379  * ForeignPath represents a potential scan of a foreign table, foreign join
1380  * or foreign upper-relation.
1381  *
1382  * fdw_private stores FDW private data about the scan. While fdw_private is
1383  * not actually touched by the core code during normal operations, it's
1384  * generally a good idea to use a representation that can be dumped by
1385  * nodeToString(), so that you can examine the structure during debugging
1386  * with tools like pprint().
1387  */
1388 typedef struct ForeignPath
1389 {
1393 } ForeignPath;
1394 
1395 /*
1396  * CustomPath represents a table scan done by some out-of-core extension.
1397  *
1398  * We provide a set of hooks here - which the provider must take care to set
1399  * up correctly - to allow extensions to supply their own methods of scanning
1400  * a relation. For example, a provider might provide GPU acceleration, a
1401  * cache-based scan, or some other kind of logic we haven't dreamed up yet.
1402  *
1403  * CustomPaths can be injected into the planning process for a relation by
1404  * set_rel_pathlist_hook functions.
1405  *
1406  * Core code must avoid assuming that the CustomPath is only as large as
1407  * the structure declared here; providers are allowed to make it the first
1408  * element in a larger structure. (Since the planner never copies Paths,
1409  * this doesn't add any complication.) However, for consistency with the
1410  * FDW case, we provide a "custom_private" field in CustomPath; providers
1411  * may prefer to use that rather than define another struct type.
1412  */
1413 
1414 struct CustomPathMethods;
1415 
1416 typedef struct CustomPath
1417 {
1419  uint32 flags; /* mask of CUSTOMPATH_* flags, see
1420  * nodes/extensible.h */
1421  List *custom_paths; /* list of child Path nodes, if any */
1424 } CustomPath;
1425 
1426 /*
1427  * AppendPath represents an Append plan, ie, successive execution of
1428  * several member plans.
1429  *
1430  * For partial Append, 'subpaths' contains non-partial subpaths followed by
1431  * partial subpaths.
1432  *
1433  * Note: it is possible for "subpaths" to contain only one, or even no,
1434  * elements. These cases are optimized during create_append_plan.
1435  * In particular, an AppendPath with no subpaths is a "dummy" path that
1436  * is created to represent the case that a relation is provably empty.
1437  * (This is a convenient representation because it means that when we build
1438  * an appendrel and find that all its children have been excluded, no extra
1439  * action is needed to recognize the relation as dummy.)
1440  */
1441 typedef struct AppendPath
1442 {
1444  List *subpaths; /* list of component Paths */
1445  /* Index of first partial path in subpaths; list_length(subpaths) if none */
1447  double limit_tuples; /* hard limit on output tuples, or -1 */
1448 } AppendPath;
1449 
1450 #define IS_DUMMY_APPEND(p) \
1451  (IsA((p), AppendPath) && ((AppendPath *) (p))->subpaths == NIL)
1452 
1453 /*
1454  * A relation that's been proven empty will have one path that is dummy
1455  * (but might have projection paths on top). For historical reasons,
1456  * this is provided as a macro that wraps is_dummy_rel().
1457  */
1458 #define IS_DUMMY_REL(r) is_dummy_rel(r)
1459 extern bool is_dummy_rel(RelOptInfo *rel);
1460 
1461 /*
1462  * MergeAppendPath represents a MergeAppend plan, ie, the merging of sorted
1463  * results from several member plans to produce similarly-sorted output.
1464  */
1465 typedef struct MergeAppendPath
1466 {
1468  List *subpaths; /* list of component Paths */
1469  double limit_tuples; /* hard limit on output tuples, or -1 */
1470 } MergeAppendPath;
1471 
1472 /*
1473  * GroupResultPath represents use of a Result plan node to compute the
1474  * output of a degenerate GROUP BY case, wherein we know we should produce
1475  * exactly one row, which might then be filtered by a HAVING qual.
1476  *
1477  * Note that quals is a list of bare clauses, not RestrictInfos.
1478  */
1479 typedef struct GroupResultPath
1480 {
1483 } GroupResultPath;
1484 
1485 /*
1486  * MaterialPath represents use of a Material plan node, i.e., caching of
1487  * the output of its subpath. This is used when the subpath is expensive
1488  * and needs to be scanned repeatedly, or when we need mark/restore ability
1489  * and the subpath doesn't have it.
1490  */
1491 typedef struct MaterialPath
1492 {
1495 } MaterialPath;
1496 
1497 /*
1498  * ResultCachePath represents a ResultCache plan node, i.e., a cache that
1499  * caches tuples from parameterized paths to save the underlying node from
1500  * having to be rescanned for parameter values which are already cached.
1501  */
1502 typedef struct ResultCachePath
1503 {
1505  Path *subpath; /* outerpath to cache tuples from */
1506  List *hash_operators; /* hash operators for each key */
1507  List *param_exprs; /* cache keys */
1508  bool singlerow; /* true if the cache entry is to be marked as
1509  * complete after caching the first record. */
1510  double calls; /* expected number of rescans */
1511  uint32 est_entries; /* The maximum number of entries that the
1512  * planner expects will fit in the cache, or 0
1513  * if unknown */
1514 } ResultCachePath;
1515 
1516 /*
1517  * UniquePath represents elimination of distinct rows from the output of
1518  * its subpath.
1519  *
1520  * This can represent significantly different plans: either hash-based or
1521  * sort-based implementation, or a no-op if the input path can be proven
1522  * distinct already. The decision is sufficiently localized that it's not
1523  * worth having separate Path node types. (Note: in the no-op case, we could
1524  * eliminate the UniquePath node entirely and just return the subpath; but
1525  * it's convenient to have a UniquePath in the path tree to signal upper-level
1526  * routines that the input is known distinct.)
1527  */
1528 typedef enum
1529 {
1530  UNIQUE_PATH_NOOP, /* input is known unique already */
1531  UNIQUE_PATH_HASH, /* use hashing */
1532  UNIQUE_PATH_SORT /* use sorting */
1534 
1535 typedef struct UniquePath
1536 {
1540  List *in_operators; /* equality operators of the IN clause */
1541  List *uniq_exprs; /* expressions to be made unique */
1542 } UniquePath;
1543 
1544 /*
1545  * GatherPath runs several copies of a plan in parallel and collects the
1546  * results. The parallel leader may also execute the plan, unless the
1547  * single_copy flag is set.
1548  */
1549 typedef struct GatherPath
1550 {
1552  Path *subpath; /* path for each worker */
1553  bool single_copy; /* don't execute path more than once */
1554  int num_workers; /* number of workers sought to help */
1555 } GatherPath;
1556 
1557 /*
1558  * GatherMergePath runs several copies of a plan in parallel and collects
1559  * the results, preserving their common sort order.
1560  */
1561 typedef struct GatherMergePath
1562 {
1564  Path *subpath; /* path for each worker */
1565  int num_workers; /* number of workers sought to help */
1566 } GatherMergePath;
1567 
1568 
1569 /*
1570  * All join-type paths share these fields.
1571  */
1572 
1573 typedef struct JoinPath
1574 {
1576 
1578 
1579  bool inner_unique; /* each outer tuple provably matches no more
1580  * than one inner tuple */
1581 
1582  Path *outerjoinpath; /* path for the outer side of the join */
1583  Path *innerjoinpath; /* path for the inner side of the join */
1584 
1585  List *joinrestrictinfo; /* RestrictInfos to apply to join */
1586 
1587  /*
1588  * See the notes for RelOptInfo and ParamPathInfo to understand why
1589  * joinrestrictinfo is needed in JoinPath, and can't be merged into the
1590  * parent RelOptInfo.
1591  */
1592 } JoinPath;
1593 
1594 /*
1595  * A nested-loop path needs no special fields.
1596  */
1597 
1599 
1600 /*
1601  * A mergejoin path has these fields.
1602  *
1603  * Unlike other path types, a MergePath node doesn't represent just a single
1604  * run-time plan node: it can represent up to four. Aside from the MergeJoin
1605  * node itself, there can be a Sort node for the outer input, a Sort node
1606  * for the inner input, and/or a Material node for the inner input. We could
1607  * represent these nodes by separate path nodes, but considering how many
1608  * different merge paths are investigated during a complex join problem,
1609  * it seems better to avoid unnecessary palloc overhead.
1610  *
1611  * path_mergeclauses lists the clauses (in the form of RestrictInfos)
1612  * that will be used in the merge.
1613  *
1614  * Note that the mergeclauses are a subset of the parent relation's
1615  * restriction-clause list. Any join clauses that are not mergejoinable
1616  * appear only in the parent's restrict list, and must be checked by a
1617  * qpqual at execution time.
1618  *
1619  * outersortkeys (resp. innersortkeys) is NIL if the outer path
1620  * (resp. inner path) is already ordered appropriately for the
1621  * mergejoin. If it is not NIL then it is a PathKeys list describing
1622  * the ordering that must be created by an explicit Sort node.
1623  *
1624  * skip_mark_restore is true if the executor need not do mark/restore calls.
1625  * Mark/restore overhead is usually required, but can be skipped if we know
1626  * that the executor need find only one match per outer tuple, and that the
1627  * mergeclauses are sufficient to identify a match. In such cases the
1628  * executor can immediately advance the outer relation after processing a
1629  * match, and therefore it need never back up the inner relation.
1630  *
1631  * materialize_inner is true if a Material node should be placed atop the
1632  * inner input. This may appear with or without an inner Sort step.
1633  */
1634 
1635 typedef struct MergePath
1636 {
1638  List *path_mergeclauses; /* join clauses to be used for merge */
1639  List *outersortkeys; /* keys for explicit sort, if any */
1640  List *innersortkeys; /* keys for explicit sort, if any */
1641  bool skip_mark_restore; /* can executor skip mark/restore? */
1642  bool materialize_inner; /* add Materialize to inner? */
1643 } MergePath;
1644 
1645 /*
1646  * A hashjoin path has these fields.
1647  *
1648  * The remarks above for mergeclauses apply for hashclauses as well.
1649  *
1650  * Hashjoin does not care what order its inputs appear in, so we have
1651  * no need for sortkeys.
1652  */
1653 
1654 typedef struct HashPath
1655 {
1657  List *path_hashclauses; /* join clauses used for hashing */
1658  int num_batches; /* number of batches expected */
1659  double inner_rows_total; /* total inner rows expected */
1660 } HashPath;
1661 
1662 /*
1663  * ProjectionPath represents a projection (that is, targetlist computation)
1664  *
1665  * Nominally, this path node represents using a Result plan node to do a
1666  * projection step. However, if the input plan node supports projection,
1667  * we can just modify its output targetlist to do the required calculations
1668  * directly, and not need a Result. In some places in the planner we can just
1669  * jam the desired PathTarget into the input path node (and adjust its cost
1670  * accordingly), so we don't need a ProjectionPath. But in other places
1671  * it's necessary to not modify the input path node, so we need a separate
1672  * ProjectionPath node, which is marked dummy to indicate that we intend to
1673  * assign the work to the input plan node. The estimated cost for the
1674  * ProjectionPath node will account for whether a Result will be used or not.
1675  */
1676 typedef struct ProjectionPath
1677 {
1679  Path *subpath; /* path representing input source */
1680  bool dummypp; /* true if no separate Result is needed */
1681 } ProjectionPath;
1682 
1683 /*
1684  * ProjectSetPath represents evaluation of a targetlist that includes
1685  * set-returning function(s), which will need to be implemented by a
1686  * ProjectSet plan node.
1687  */
1688 typedef struct ProjectSetPath
1689 {
1691  Path *subpath; /* path representing input source */
1692 } ProjectSetPath;
1693 
1694 /*
1695  * SortPath represents an explicit sort step
1696  *
1697  * The sort keys are, by definition, the same as path.pathkeys.
1698  *
1699  * Note: the Sort plan node cannot project, so path.pathtarget must be the
1700  * same as the input's pathtarget.
1701  */
1702 typedef struct SortPath
1703 {
1705  Path *subpath; /* path representing input source */
1706 } SortPath;
1707 
1708 /*
1709  * IncrementalSortPath represents an incremental sort step
1710  *
1711  * This is like a regular sort, except some leading key columns are assumed
1712  * to be ordered already.
1713  */
1714 typedef struct IncrementalSortPath
1715 {
1717  int nPresortedCols; /* number of presorted columns */
1719 
1720 /*
1721  * GroupPath represents grouping (of presorted input)
1722  *
1723  * groupClause represents the columns to be grouped on; the input path
1724  * must be at least that well sorted.
1725  *
1726  * We can also apply a qual to the grouped rows (equivalent of HAVING)
1727  */
1728 typedef struct GroupPath
1729 {
1731  Path *subpath; /* path representing input source */
1732  List *groupClause; /* a list of SortGroupClause's */
1733  List *qual; /* quals (HAVING quals), if any */
1734 } GroupPath;
1735 
1736 /*
1737  * UpperUniquePath represents adjacent-duplicate removal (in presorted input)
1738  *
1739  * The columns to be compared are the first numkeys columns of the path's
1740  * pathkeys. The input is presumed already sorted that way.
1741  */
1742 typedef struct UpperUniquePath
1743 {
1745  Path *subpath; /* path representing input source */
1746  int numkeys; /* number of pathkey columns to compare */
1747 } UpperUniquePath;
1748 
1749 /*
1750  * AggPath represents generic computation of aggregate functions
1751  *
1752  * This may involve plain grouping (but not grouping sets), using either
1753  * sorted or hashed grouping; for the AGG_SORTED case, the input must be
1754  * appropriately presorted.
1755  */
1756 typedef struct AggPath
1757 {
1759  Path *subpath; /* path representing input source */
1760  AggStrategy aggstrategy; /* basic strategy, see nodes.h */
1761  AggSplit aggsplit; /* agg-splitting mode, see nodes.h */
1762  double numGroups; /* estimated number of groups in input */
1763  uint64 transitionSpace; /* for pass-by-ref transition data */
1764  List *groupClause; /* a list of SortGroupClause's */
1765  List *qual; /* quals (HAVING quals), if any */
1766 } AggPath;
1767 
1768 /*
1769  * Various annotations used for grouping sets in the planner.
1770  */
1771 
1772 typedef struct GroupingSetData
1773 {
1775  List *set; /* grouping set as list of sortgrouprefs */
1776  double numGroups; /* est. number of result groups */
1777 } GroupingSetData;
1778 
1779 typedef struct RollupData
1780 {
1782  List *groupClause; /* applicable subset of parse->groupClause */
1783  List *gsets; /* lists of integer indexes into groupClause */
1784  List *gsets_data; /* list of GroupingSetData */
1785  double numGroups; /* est. number of result groups */
1786  bool hashable; /* can be hashed */
1787  bool is_hashed; /* to be implemented as a hashagg */
1788 } RollupData;
1789 
1790 /*
1791  * GroupingSetsPath represents a GROUPING SETS aggregation
1792  */
1793 
1794 typedef struct GroupingSetsPath
1795 {
1797  Path *subpath; /* path representing input source */
1798  AggStrategy aggstrategy; /* basic strategy */
1799  List *rollups; /* list of RollupData */
1800  List *qual; /* quals (HAVING quals), if any */
1801  uint64 transitionSpace; /* for pass-by-ref transition data */
1803 
1804 /*
1805  * MinMaxAggPath represents computation of MIN/MAX aggregates from indexes
1806  */
1807 typedef struct MinMaxAggPath
1808 {
1810  List *mmaggregates; /* list of MinMaxAggInfo */
1811  List *quals; /* HAVING quals, if any */
1812 } MinMaxAggPath;
1813 
1814 /*
1815  * WindowAggPath represents generic computation of window functions
1816  */
1817 typedef struct WindowAggPath
1818 {
1820  Path *subpath; /* path representing input source */
1821  WindowClause *winclause; /* WindowClause we'll be using */
1822 } WindowAggPath;
1823 
1824 /*
1825  * SetOpPath represents a set-operation, that is INTERSECT or EXCEPT
1826  */
1827 typedef struct SetOpPath
1828 {
1830  Path *subpath; /* path representing input source */
1831  SetOpCmd cmd; /* what to do, see nodes.h */
1832  SetOpStrategy strategy; /* how to do it, see nodes.h */
1833  List *distinctList; /* SortGroupClauses identifying target cols */
1834  AttrNumber flagColIdx; /* where is the flag column, if any */
1835  int firstFlag; /* flag value for first input relation */
1836  double numGroups; /* estimated number of groups in input */
1837 } SetOpPath;
1838 
1839 /*
1840  * RecursiveUnionPath represents a recursive UNION node
1841  */
1842 typedef struct RecursiveUnionPath
1843 {
1845  Path *leftpath; /* paths representing input sources */
1847  List *distinctList; /* SortGroupClauses identifying target cols */
1848  int wtParam; /* ID of Param representing work table */
1849  double numGroups; /* estimated number of groups in input */
1851 
1852 /*
1853  * LockRowsPath represents acquiring row locks for SELECT FOR UPDATE/SHARE
1854  */
1855 typedef struct LockRowsPath
1856 {
1858  Path *subpath; /* path representing input source */
1859  List *rowMarks; /* a list of PlanRowMark's */
1860  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1861 } LockRowsPath;
1862 
1863 /*
1864  * ModifyTablePath represents performing INSERT/UPDATE/DELETE modifications
1865  *
1866  * We represent most things that will be in the ModifyTable plan node
1867  * literally, except we have a child Path not Plan. But analysis of the
1868  * OnConflictExpr is deferred to createplan.c, as is collection of FDW data.
1869  */
1870 typedef struct ModifyTablePath
1871 {
1873  Path *subpath; /* Path producing source data */
1874  CmdType operation; /* INSERT, UPDATE, or DELETE */
1875  bool canSetTag; /* do we set the command tag/es_processed? */
1876  Index nominalRelation; /* Parent RT index for use of EXPLAIN */
1877  Index rootRelation; /* Root RT index, if target is partitioned */
1878  bool partColsUpdated; /* some part key in hierarchy updated? */
1879  List *resultRelations; /* integer list of RT indexes */
1880  List *updateColnosLists; /* per-target-table update_colnos lists */
1881  List *withCheckOptionLists; /* per-target-table WCO lists */
1882  List *returningLists; /* per-target-table RETURNING tlists */
1883  List *rowMarks; /* PlanRowMarks (non-locking only) */
1884  OnConflictExpr *onconflict; /* ON CONFLICT clause, or NULL */
1885  int epqParam; /* ID of Param for EvalPlanQual re-eval */
1886 } ModifyTablePath;
1887 
1888 /*
1889  * LimitPath represents applying LIMIT/OFFSET restrictions
1890  */
1891 typedef struct LimitPath
1892 {
1894  Path *subpath; /* path representing input source */
1895  Node *limitOffset; /* OFFSET parameter, or NULL if none */
1896  Node *limitCount; /* COUNT parameter, or NULL if none */
1897  LimitOption limitOption; /* FETCH FIRST with ties or exact number */
1898 } LimitPath;
1899 
1900 
1901 /*
1902  * Restriction clause info.
1903  *
1904  * We create one of these for each AND sub-clause of a restriction condition
1905  * (WHERE or JOIN/ON clause). Since the restriction clauses are logically
1906  * ANDed, we can use any one of them or any subset of them to filter out
1907  * tuples, without having to evaluate the rest. The RestrictInfo node itself
1908  * stores data used by the optimizer while choosing the best query plan.
1909  *
1910  * If a restriction clause references a single base relation, it will appear
1911  * in the baserestrictinfo list of the RelOptInfo for that base rel.
1912  *
1913  * If a restriction clause references more than one base rel, it will
1914  * appear in the joininfo list of every RelOptInfo that describes a strict
1915  * subset of the base rels mentioned in the clause. The joininfo lists are
1916  * used to drive join tree building by selecting plausible join candidates.
1917  * The clause cannot actually be applied until we have built a join rel
1918  * containing all the base rels it references, however.
1919  *
1920  * When we construct a join rel that includes all the base rels referenced
1921  * in a multi-relation restriction clause, we place that clause into the
1922  * joinrestrictinfo lists of paths for the join rel, if neither left nor
1923  * right sub-path includes all base rels referenced in the clause. The clause
1924  * will be applied at that join level, and will not propagate any further up
1925  * the join tree. (Note: the "predicate migration" code was once intended to
1926  * push restriction clauses up and down the plan tree based on evaluation
1927  * costs, but it's dead code and is unlikely to be resurrected in the
1928  * foreseeable future.)
1929  *
1930  * Note that in the presence of more than two rels, a multi-rel restriction
1931  * might reach different heights in the join tree depending on the join
1932  * sequence we use. So, these clauses cannot be associated directly with
1933  * the join RelOptInfo, but must be kept track of on a per-join-path basis.
1934  *
1935  * RestrictInfos that represent equivalence conditions (i.e., mergejoinable
1936  * equalities that are not outerjoin-delayed) are handled a bit differently.
1937  * Initially we attach them to the EquivalenceClasses that are derived from
1938  * them. When we construct a scan or join path, we look through all the
1939  * EquivalenceClasses and generate derived RestrictInfos representing the
1940  * minimal set of conditions that need to be checked for this particular scan
1941  * or join to enforce that all members of each EquivalenceClass are in fact
1942  * equal in all rows emitted by the scan or join.
1943  *
1944  * When dealing with outer joins we have to be very careful about pushing qual
1945  * clauses up and down the tree. An outer join's own JOIN/ON conditions must
1946  * be evaluated exactly at that join node, unless they are "degenerate"
1947  * conditions that reference only Vars from the nullable side of the join.
1948  * Quals appearing in WHERE or in a JOIN above the outer join cannot be pushed
1949  * down below the outer join, if they reference any nullable Vars.
1950  * RestrictInfo nodes contain a flag to indicate whether a qual has been
1951  * pushed down to a lower level than its original syntactic placement in the
1952  * join tree would suggest. If an outer join prevents us from pushing a qual
1953  * down to its "natural" semantic level (the level associated with just the
1954  * base rels used in the qual) then we mark the qual with a "required_relids"
1955  * value including more than just the base rels it actually uses. By
1956  * pretending that the qual references all the rels required to form the outer
1957  * join, we prevent it from being evaluated below the outer join's joinrel.
1958  * When we do form the outer join's joinrel, we still need to distinguish
1959  * those quals that are actually in that join's JOIN/ON condition from those
1960  * that appeared elsewhere in the tree and were pushed down to the join rel
1961  * because they used no other rels. That's what the is_pushed_down flag is
1962  * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
1963  * rels listed in required_relids. A clause that originally came from WHERE
1964  * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
1965  * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
1966  * if we decide that it can be pushed down into the nullable side of the join.
1967  * In that case it acts as a plain filter qual for wherever it gets evaluated.
1968  * (In short, is_pushed_down is only false for non-degenerate outer join
1969  * conditions. Possibly we should rename it to reflect that meaning? But
1970  * see also the comments for RINFO_IS_PUSHED_DOWN, below.)
1971  *
1972  * RestrictInfo nodes also contain an outerjoin_delayed flag, which is true
1973  * if the clause's applicability must be delayed due to any outer joins
1974  * appearing below it (ie, it has to be postponed to some join level higher
1975  * than the set of relations it actually references).
1976  *
1977  * There is also an outer_relids field, which is NULL except for outer join
1978  * clauses; for those, it is the set of relids on the outer side of the
1979  * clause's outer join. (These are rels that the clause cannot be applied to
1980  * in parameterized scans, since pushing it into the join's outer side would
1981  * lead to wrong answers.)
1982  *
1983  * There is also a nullable_relids field, which is the set of rels the clause
1984  * references that can be forced null by some outer join below the clause.
1985  *
1986  * outerjoin_delayed = true is subtly different from nullable_relids != NULL:
1987  * a clause might reference some nullable rels and yet not be
1988  * outerjoin_delayed because it also references all the other rels of the
1989  * outer join(s). A clause that is not outerjoin_delayed can be enforced
1990  * anywhere it is computable.
1991  *
1992  * To handle security-barrier conditions efficiently, we mark RestrictInfo
1993  * nodes with a security_level field, in which higher values identify clauses
1994  * coming from less-trusted sources. The exact semantics are that a clause
1995  * cannot be evaluated before another clause with a lower security_level value
1996  * unless the first clause is leakproof. As with outer-join clauses, this
1997  * creates a reason for clauses to sometimes need to be evaluated higher in
1998  * the join tree than their contents would suggest; and even at a single plan
1999  * node, this rule constrains the order of application of clauses.
2000  *
2001  * In general, the referenced clause might be arbitrarily complex. The
2002  * kinds of clauses we can handle as indexscan quals, mergejoin clauses,
2003  * or hashjoin clauses are limited (e.g., no volatile functions). The code
2004  * for each kind of path is responsible for identifying the restrict clauses
2005  * it can use and ignoring the rest. Clauses not implemented by an indexscan,
2006  * mergejoin, or hashjoin will be placed in the plan qual or joinqual field
2007  * of the finished Plan node, where they will be enforced by general-purpose
2008  * qual-expression-evaluation code. (But we are still entitled to count
2009  * their selectivity when estimating the result tuple count, if we
2010  * can guess what it is...)
2011  *
2012  * When the referenced clause is an OR clause, we generate a modified copy
2013  * in which additional RestrictInfo nodes are inserted below the top-level
2014  * OR/AND structure. This is a convenience for OR indexscan processing:
2015  * indexquals taken from either the top level or an OR subclause will have
2016  * associated RestrictInfo nodes.
2017  *
2018  * The can_join flag is set true if the clause looks potentially useful as
2019  * a merge or hash join clause, that is if it is a binary opclause with
2020  * nonoverlapping sets of relids referenced in the left and right sides.
2021  * (Whether the operator is actually merge or hash joinable isn't checked,
2022  * however.)
2023  *
2024  * The pseudoconstant flag is set true if the clause contains no Vars of
2025  * the current query level and no volatile functions. Such a clause can be
2026  * pulled out and used as a one-time qual in a gating Result node. We keep
2027  * pseudoconstant clauses in the same lists as other RestrictInfos so that
2028  * the regular clause-pushing machinery can assign them to the correct join
2029  * level, but they need to be treated specially for cost and selectivity
2030  * estimates. Note that a pseudoconstant clause can never be an indexqual
2031  * or merge or hash join clause, so it's of no interest to large parts of
2032  * the planner.
2033  *
2034  * When join clauses are generated from EquivalenceClasses, there may be
2035  * several equally valid ways to enforce join equivalence, of which we need
2036  * apply only one. We mark clauses of this kind by setting parent_ec to
2037  * point to the generating EquivalenceClass. Multiple clauses with the same
2038  * parent_ec in the same join are redundant.
2039  */
2040 
2041 typedef struct RestrictInfo
2042 {
2044 
2045  Expr *clause; /* the represented clause of WHERE or JOIN */
2046 
2047  bool is_pushed_down; /* true if clause was pushed down in level */
2048 
2049  bool outerjoin_delayed; /* true if delayed by lower outer join */
2050 
2051  bool can_join; /* see comment above */
2052 
2053  bool pseudoconstant; /* see comment above */
2054 
2055  bool leakproof; /* true if known to contain no leaked Vars */
2056 
2057  VolatileFunctionStatus has_volatile; /* to indicate if clause contains
2058  * any volatile functions. */
2059 
2060  Index security_level; /* see comment above */
2061 
2062  /* The set of relids (varnos) actually referenced in the clause: */
2064 
2065  /* The set of relids required to evaluate the clause: */
2067 
2068  /* If an outer-join clause, the outer-side relations, else NULL: */
2070 
2071  /* The relids used in the clause that are nullable by lower outer joins: */
2073 
2074  /* These fields are set for any binary opclause: */
2075  Relids left_relids; /* relids in left side of clause */
2076  Relids right_relids; /* relids in right side of clause */
2077 
2078  /* This field is NULL unless clause is an OR clause: */
2079  Expr *orclause; /* modified clause with RestrictInfos */
2080 
2081  /* This field is NULL unless clause is potentially redundant: */
2082  EquivalenceClass *parent_ec; /* generating EquivalenceClass */
2083 
2084  /* cache space for cost and selectivity */
2085  QualCost eval_cost; /* eval cost of clause; -1 if not yet set */
2086  Selectivity norm_selec; /* selectivity for "normal" (JOIN_INNER)
2087  * semantics; -1 if not yet set; >1 means a
2088  * redundant clause */
2089  Selectivity outer_selec; /* selectivity for outer join semantics; -1 if
2090  * not yet set */
2091 
2092  /* valid if clause is mergejoinable, else NIL */
2093  List *mergeopfamilies; /* opfamilies containing clause operator */
2094 
2095  /* cache space for mergeclause processing; NULL if not yet set */
2096  EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
2097  EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
2098  EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
2099  EquivalenceMember *right_em; /* EquivalenceMember for righthand */
2100  List *scansel_cache; /* list of MergeScanSelCache structs */
2101 
2102  /* transient workspace for use while considering a specific join path */
2103  bool outer_is_left; /* T = outer var on left, F = on right */
2104 
2105  /* valid if clause is hashjoinable, else InvalidOid: */
2106  Oid hashjoinoperator; /* copy of clause operator */
2107 
2108  /* cache space for hashclause processing; -1 if not yet set */
2109  Selectivity left_bucketsize; /* avg bucketsize of left side */
2110  Selectivity right_bucketsize; /* avg bucketsize of right side */
2111  Selectivity left_mcvfreq; /* left side's most common val's freq */
2112  Selectivity right_mcvfreq; /* right side's most common val's freq */
2113 
2114  /* hash equality operator used for result cache, else InvalidOid */
2116 } RestrictInfo;
2117 
2118 /*
2119  * This macro embodies the correct way to test whether a RestrictInfo is
2120  * "pushed down" to a given outer join, that is, should be treated as a filter
2121  * clause rather than a join clause at that outer join. This is certainly so
2122  * if is_pushed_down is true; but examining that is not sufficient anymore,
2123  * because outer-join clauses will get pushed down to lower outer joins when
2124  * we generate a path for the lower outer join that is parameterized by the
2125  * LHS of the upper one. We can detect such a clause by noting that its
2126  * required_relids exceed the scope of the join.
2127  */
2128 #define RINFO_IS_PUSHED_DOWN(rinfo, joinrelids) \
2129  ((rinfo)->is_pushed_down || \
2130  !bms_is_subset((rinfo)->required_relids, joinrelids))
2131 
2132 /*
2133  * Since mergejoinscansel() is a relatively expensive function, and would
2134  * otherwise be invoked many times while planning a large join tree,
2135  * we go out of our way to cache its results. Each mergejoinable
2136  * RestrictInfo carries a list of the specific sort orderings that have
2137  * been considered for use with it, and the resulting selectivities.
2138  */
2139 typedef struct MergeScanSelCache
2140 {
2141  /* Ordering details (cache lookup key) */
2142  Oid opfamily; /* btree opfamily defining the ordering */
2143  Oid collation; /* collation for the ordering */
2144  int strategy; /* sort direction (ASC or DESC) */
2145  bool nulls_first; /* do NULLs come before normal values? */
2146  /* Results */
2147  Selectivity leftstartsel; /* first-join fraction for clause left side */
2148  Selectivity leftendsel; /* last-join fraction for clause left side */
2149  Selectivity rightstartsel; /* first-join fraction for clause right side */
2150  Selectivity rightendsel; /* last-join fraction for clause right side */
2152 
2153 /*
2154  * Placeholder node for an expression to be evaluated below the top level
2155  * of a plan tree. This is used during planning to represent the contained
2156  * expression. At the end of the planning process it is replaced by either
2157  * the contained expression or a Var referring to a lower-level evaluation of
2158  * the contained expression. Typically the evaluation occurs below an outer
2159  * join, and Var references above the outer join might thereby yield NULL
2160  * instead of the expression value.
2161  *
2162  * Although the planner treats this as an expression node type, it is not
2163  * recognized by the parser or executor, so we declare it here rather than
2164  * in primnodes.h.
2165  */
2166 
2167 typedef struct PlaceHolderVar
2168 {
2170  Expr *phexpr; /* the represented expression */
2171  Relids phrels; /* base relids syntactically within expr src */
2172  Index phid; /* ID for PHV (unique within planner run) */
2173  Index phlevelsup; /* > 0 if PHV belongs to outer query */
2174 } PlaceHolderVar;
2175 
2176 /*
2177  * "Special join" info.
2178  *
2179  * One-sided outer joins constrain the order of joining partially but not
2180  * completely. We flatten such joins into the planner's top-level list of
2181  * relations to join, but record information about each outer join in a
2182  * SpecialJoinInfo struct. These structs are kept in the PlannerInfo node's
2183  * join_info_list.
2184  *
2185  * Similarly, semijoins and antijoins created by flattening IN (subselect)
2186  * and EXISTS(subselect) clauses create partial constraints on join order.
2187  * These are likewise recorded in SpecialJoinInfo structs.
2188  *
2189  * We make SpecialJoinInfos for FULL JOINs even though there is no flexibility
2190  * of planning for them, because this simplifies make_join_rel()'s API.
2191  *
2192  * min_lefthand and min_righthand are the sets of base relids that must be
2193  * available on each side when performing the special join. lhs_strict is
2194  * true if the special join's condition cannot succeed when the LHS variables
2195  * are all NULL (this means that an outer join can commute with upper-level
2196  * outer joins even if it appears in their RHS). We don't bother to set
2197  * lhs_strict for FULL JOINs, however.
2198  *
2199  * It is not valid for either min_lefthand or min_righthand to be empty sets;
2200  * if they were, this would break the logic that enforces join order.
2201  *
2202  * syn_lefthand and syn_righthand are the sets of base relids that are
2203  * syntactically below this special join. (These are needed to help compute
2204  * min_lefthand and min_righthand for higher joins.)
2205  *
2206  * delay_upper_joins is set true if we detect a pushed-down clause that has
2207  * to be evaluated after this join is formed (because it references the RHS).
2208  * Any outer joins that have such a clause and this join in their RHS cannot
2209  * commute with this join, because that would leave noplace to check the
2210  * pushed-down clause. (We don't track this for FULL JOINs, either.)
2211  *
2212  * For a semijoin, we also extract the join operators and their RHS arguments
2213  * and set semi_operators, semi_rhs_exprs, semi_can_btree, and semi_can_hash.
2214  * This is done in support of possibly unique-ifying the RHS, so we don't
2215  * bother unless at least one of semi_can_btree and semi_can_hash can be set
2216  * true. (You might expect that this information would be computed during
2217  * join planning; but it's helpful to have it available during planning of
2218  * parameterized table scans, so we store it in the SpecialJoinInfo structs.)
2219  *
2220  * jointype is never JOIN_RIGHT; a RIGHT JOIN is handled by switching
2221  * the inputs to make it a LEFT JOIN. So the allowed values of jointype
2222  * in a join_info_list member are only LEFT, FULL, SEMI, or ANTI.
2223  *
2224  * For purposes of join selectivity estimation, we create transient
2225  * SpecialJoinInfo structures for regular inner joins; so it is possible
2226  * to have jointype == JOIN_INNER in such a structure, even though this is
2227  * not allowed within join_info_list. We also create transient
2228  * SpecialJoinInfos with jointype == JOIN_INNER for outer joins, since for
2229  * cost estimation purposes it is sometimes useful to know the join size under
2230  * plain innerjoin semantics. Note that lhs_strict, delay_upper_joins, and
2231  * of course the semi_xxx fields are not set meaningfully within such structs.
2232  */
2233 #ifndef HAVE_SPECIALJOININFO_TYPEDEF
2235 #define HAVE_SPECIALJOININFO_TYPEDEF 1
2236 #endif
2237 
2239 {
2241  Relids min_lefthand; /* base relids in minimum LHS for join */
2242  Relids min_righthand; /* base relids in minimum RHS for join */
2243  Relids syn_lefthand; /* base relids syntactically within LHS */
2244  Relids syn_righthand; /* base relids syntactically within RHS */
2245  JoinType jointype; /* always INNER, LEFT, FULL, SEMI, or ANTI */
2246  bool lhs_strict; /* joinclause is strict for some LHS rel */
2247  bool delay_upper_joins; /* can't commute with upper RHS */
2248  /* Remaining fields are set only for JOIN_SEMI jointype: */
2249  bool semi_can_btree; /* true if semi_operators are all btree */
2250  bool semi_can_hash; /* true if semi_operators are all hash */
2251  List *semi_operators; /* OIDs of equality join operators */
2252  List *semi_rhs_exprs; /* righthand-side expressions of these ops */
2253 };
2254 
2255 /*
2256  * Append-relation info.
2257  *
2258  * When we expand an inheritable table or a UNION-ALL subselect into an
2259  * "append relation" (essentially, a list of child RTEs), we build an
2260  * AppendRelInfo for each child RTE. The list of AppendRelInfos indicates
2261  * which child RTEs must be included when expanding the parent, and each node
2262  * carries information needed to translate between columns of the parent and
2263  * columns of the child.
2264  *
2265  * These structs are kept in the PlannerInfo node's append_rel_list, with
2266  * append_rel_array[] providing a convenient lookup method for the struct
2267  * associated with a particular child relid (there can be only one, though
2268  * parent rels may have many entries in append_rel_list).
2269  *
2270  * Note: after completion of the planner prep phase, any given RTE is an
2271  * append parent having entries in append_rel_list if and only if its
2272  * "inh" flag is set. We clear "inh" for plain tables that turn out not
2273  * to have inheritance children, and (in an abuse of the original meaning
2274  * of the flag) we set "inh" for subquery RTEs that turn out to be
2275  * flattenable UNION ALL queries. This lets us avoid useless searches
2276  * of append_rel_list.
2277  *
2278  * Note: the data structure assumes that append-rel members are single
2279  * baserels. This is OK for inheritance, but it prevents us from pulling
2280  * up a UNION ALL member subquery if it contains a join. While that could
2281  * be fixed with a more complex data structure, at present there's not much
2282  * point because no improvement in the plan could result.
2283  */
2284 
2285 typedef struct AppendRelInfo
2286 {
2288 
2289  /*
2290  * These fields uniquely identify this append relationship. There can be
2291  * (in fact, always should be) multiple AppendRelInfos for the same
2292  * parent_relid, but never more than one per child_relid, since a given
2293  * RTE cannot be a child of more than one append parent.
2294  */
2295  Index parent_relid; /* RT index of append parent rel */
2296  Index child_relid; /* RT index of append child rel */
2297 
2298  /*
2299  * For an inheritance appendrel, the parent and child are both regular
2300  * relations, and we store their rowtype OIDs here for use in translating
2301  * whole-row Vars. For a UNION-ALL appendrel, the parent and child are
2302  * both subqueries with no named rowtype, and we store InvalidOid here.
2303  */
2304  Oid parent_reltype; /* OID of parent's composite type */
2305  Oid child_reltype; /* OID of child's composite type */
2306 
2307  /*
2308  * The N'th element of this list is a Var or expression representing the
2309  * child column corresponding to the N'th column of the parent. This is
2310  * used to translate Vars referencing the parent rel into references to
2311  * the child. A list element is NULL if it corresponds to a dropped
2312  * column of the parent (this is only possible for inheritance cases, not
2313  * UNION ALL). The list elements are always simple Vars for inheritance
2314  * cases, but can be arbitrary expressions in UNION ALL cases.
2315  *
2316  * Notice we only store entries for user columns (attno > 0). Whole-row
2317  * Vars are special-cased, and system columns (attno < 0) need no special
2318  * translation since their attnos are the same for all tables.
2319  *
2320  * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed
2321  * when copying into a subquery.
2322  */
2323  List *translated_vars; /* Expressions in the child's Vars */
2324 
2325  /*
2326  * This array simplifies translations in the reverse direction, from
2327  * child's column numbers to parent's. The entry at [ccolno - 1] is the
2328  * 1-based parent column number for child column ccolno, or zero if that
2329  * child column is dropped or doesn't exist in the parent.
2330  */
2331  int num_child_cols; /* length of array */
2332  AttrNumber *parent_colnos; /* array of parent attnos, or zeroes */
2333 
2334  /*
2335  * We store the parent table's OID here for inheritance, or InvalidOid for
2336  * UNION ALL. This is only needed to help in generating error messages if
2337  * an attempt is made to reference a dropped parent column.
2338  */
2339  Oid parent_reloid; /* OID of parent relation */
2340 } AppendRelInfo;
2341 
2342 /*
2343  * Information about a row-identity "resjunk" column in UPDATE/DELETE.
2344  *
2345  * In partitioned UPDATE/DELETE it's important for child partitions to share
2346  * row-identity columns whenever possible, so as not to chew up too many
2347  * targetlist columns. We use these structs to track which identity columns
2348  * have been requested. In the finished plan, each of these will give rise
2349  * to one resjunk entry in the targetlist of the ModifyTable's subplan node.
2350  *
2351  * All the Vars stored in RowIdentityVarInfos must have varno ROWID_VAR, for
2352  * convenience of detecting duplicate requests. We'll replace that, in the
2353  * final plan, with the varno of the generating rel.
2354  *
2355  * Outside this list, a Var with varno ROWID_VAR and varattno k is a reference
2356  * to the k-th element of the row_identity_vars list (k counting from 1).
2357  * We add such a reference to root->processed_tlist when creating the entry,
2358  * and it propagates into the plan tree from there.
2359  */
2360 typedef struct RowIdentityVarInfo
2361 {
2363 
2364  Var *rowidvar; /* Var to be evaluated (but varno=ROWID_VAR) */
2365  int32 rowidwidth; /* estimated average width */
2366  char *rowidname; /* name of the resjunk column */
2367  Relids rowidrels; /* RTE indexes of target rels using this */
2369 
2370 /*
2371  * For each distinct placeholder expression generated during planning, we
2372  * store a PlaceHolderInfo node in the PlannerInfo node's placeholder_list.
2373  * This stores info that is needed centrally rather than in each copy of the
2374  * PlaceHolderVar. The phid fields identify which PlaceHolderInfo goes with
2375  * each PlaceHolderVar. Note that phid is unique throughout a planner run,
2376  * not just within a query level --- this is so that we need not reassign ID's
2377  * when pulling a subquery into its parent.
2378  *
2379  * The idea is to evaluate the expression at (only) the ph_eval_at join level,
2380  * then allow it to bubble up like a Var until the ph_needed join level.
2381  * ph_needed has the same definition as attr_needed for a regular Var.
2382  *
2383  * The PlaceHolderVar's expression might contain LATERAL references to vars
2384  * coming from outside its syntactic scope. If so, those rels are *not*
2385  * included in ph_eval_at, but they are recorded in ph_lateral.
2386  *
2387  * Notice that when ph_eval_at is a join rather than a single baserel, the
2388  * PlaceHolderInfo may create constraints on join order: the ph_eval_at join
2389  * has to be formed below any outer joins that should null the PlaceHolderVar.
2390  *
2391  * We create a PlaceHolderInfo only after determining that the PlaceHolderVar
2392  * is actually referenced in the plan tree, so that unreferenced placeholders
2393  * don't result in unnecessary constraints on join order.
2394  */
2395 
2396 typedef struct PlaceHolderInfo
2397 {
2399 
2400  Index phid; /* ID for PH (unique within planner run) */
2401  PlaceHolderVar *ph_var; /* copy of PlaceHolderVar tree */
2402  Relids ph_eval_at; /* lowest level we can evaluate value at */
2403  Relids ph_lateral; /* relids of contained lateral refs, if any */
2404  Relids ph_needed; /* highest level the value is needed at */
2405  int32 ph_width; /* estimated attribute width */
2406 } PlaceHolderInfo;
2407 
2408 /*
2409  * This struct describes one potentially index-optimizable MIN/MAX aggregate
2410  * function. MinMaxAggPath contains a list of these, and if we accept that
2411  * path, the list is stored into root->minmax_aggs for use during setrefs.c.
2412  */
2413 typedef struct MinMaxAggInfo
2414 {
2416 
2417  Oid aggfnoid; /* pg_proc Oid of the aggregate */
2418  Oid aggsortop; /* Oid of its sort operator */
2419  Expr *target; /* expression we are aggregating on */
2420  PlannerInfo *subroot; /* modified "root" for planning the subquery */
2421  Path *path; /* access path for subquery */
2422  Cost pathcost; /* estimated cost to fetch first row */
2423  Param *param; /* param for subplan's output */
2424 } MinMaxAggInfo;
2425 
2426 /*
2427  * At runtime, PARAM_EXEC slots are used to pass values around from one plan
2428  * node to another. They can be used to pass values down into subqueries (for
2429  * outer references in subqueries), or up out of subqueries (for the results
2430  * of a subplan), or from a NestLoop plan node into its inner relation (when
2431  * the inner scan is parameterized with values from the outer relation).
2432  * The planner is responsible for assigning nonconflicting PARAM_EXEC IDs to
2433  * the PARAM_EXEC Params it generates.
2434  *
2435  * Outer references are managed via root->plan_params, which is a list of
2436  * PlannerParamItems. While planning a subquery, each parent query level's
2437  * plan_params contains the values required from it by the current subquery.
2438  * During create_plan(), we use plan_params to track values that must be
2439  * passed from outer to inner sides of NestLoop plan nodes.
2440  *
2441  * The item a PlannerParamItem represents can be one of three kinds:
2442  *
2443  * A Var: the slot represents a variable of this level that must be passed
2444  * down because subqueries have outer references to it, or must be passed
2445  * from a NestLoop node to its inner scan. The varlevelsup value in the Var
2446  * will always be zero.
2447  *
2448  * A PlaceHolderVar: this works much like the Var case, except that the
2449  * entry is a PlaceHolderVar node with a contained expression. The PHV
2450  * will have phlevelsup = 0, and the contained expression is adjusted
2451  * to match in level.
2452  *
2453  * An Aggref (with an expression tree representing its argument): the slot
2454  * represents an aggregate expression that is an outer reference for some
2455  * subquery. The Aggref itself has agglevelsup = 0, and its argument tree
2456  * is adjusted to match in level.
2457  *
2458  * Note: we detect duplicate Var and PlaceHolderVar parameters and coalesce
2459  * them into one slot, but we do not bother to do that for Aggrefs.
2460  * The scope of duplicate-elimination only extends across the set of
2461  * parameters passed from one query level into a single subquery, or for
2462  * nestloop parameters across the set of nestloop parameters used in a single
2463  * query level. So there is no possibility of a PARAM_EXEC slot being used
2464  * for conflicting purposes.
2465  *
2466  * In addition, PARAM_EXEC slots are assigned for Params representing outputs
2467  * from subplans (values that are setParam items for those subplans). These
2468  * IDs need not be tracked via PlannerParamItems, since we do not need any
2469  * duplicate-elimination nor later processing of the represented expressions.
2470  * Instead, we just record the assignment of the slot number by appending to
2471  * root->glob->paramExecTypes.
2472  */
2473 typedef struct PlannerParamItem
2474 {
2476 
2477  Node *item; /* the Var, PlaceHolderVar, or Aggref */
2478  int paramId; /* its assigned PARAM_EXEC slot number */
2480 
2481 /*
2482  * When making cost estimates for a SEMI/ANTI/inner_unique join, there are
2483  * some correction factors that are needed in both nestloop and hash joins
2484  * to account for the fact that the executor can stop scanning inner rows
2485  * as soon as it finds a match to the current outer row. These numbers
2486  * depend only on the selected outer and inner join relations, not on the
2487  * particular paths used for them, so it's worthwhile to calculate them
2488  * just once per relation pair not once per considered path. This struct
2489  * is filled by compute_semi_anti_join_factors and must be passed along
2490  * to the join cost estimation functions.
2491  *
2492  * outer_match_frac is the fraction of the outer tuples that are
2493  * expected to have at least one match.
2494  * match_count is the average number of matches expected for
2495  * outer tuples that have at least one match.
2496  */
2497 typedef struct SemiAntiJoinFactors
2498 {
2502 
2503 /*
2504  * Struct for extra information passed to subroutines of add_paths_to_joinrel
2505  *
2506  * restrictlist contains all of the RestrictInfo nodes for restriction
2507  * clauses that apply to this join
2508  * mergeclause_list is a list of RestrictInfo nodes for available
2509  * mergejoin clauses in this join
2510  * inner_unique is true if each outer tuple provably matches no more
2511  * than one inner tuple
2512  * sjinfo is extra info about special joins for selectivity estimation
2513  * semifactors is as shown above (only valid for SEMI/ANTI/inner_unique joins)
2514  * param_source_rels are OK targets for parameterization of result paths
2515  */
2516 typedef struct JoinPathExtraData
2517 {
2525 
2526 /*
2527  * Various flags indicating what kinds of grouping are possible.
2528  *
2529  * GROUPING_CAN_USE_SORT should be set if it's possible to perform
2530  * sort-based implementations of grouping. When grouping sets are in use,
2531  * this will be true if sorting is potentially usable for any of the grouping
2532  * sets, even if it's not usable for all of them.
2533  *
2534  * GROUPING_CAN_USE_HASH should be set if it's possible to perform
2535  * hash-based implementations of grouping.
2536  *
2537  * GROUPING_CAN_PARTIAL_AGG should be set if the aggregation is of a type
2538  * for which we support partial aggregation (not, for example, grouping sets).
2539  * It says nothing about parallel-safety or the availability of suitable paths.
2540  */
2541 #define GROUPING_CAN_USE_SORT 0x0001
2542 #define GROUPING_CAN_USE_HASH 0x0002
2543 #define GROUPING_CAN_PARTIAL_AGG 0x0004
2544 
2545 /*
2546  * What kind of partitionwise aggregation is in use?
2547  *
2548  * PARTITIONWISE_AGGREGATE_NONE: Not used.
2549  *
2550  * PARTITIONWISE_AGGREGATE_FULL: Aggregate each partition separately, and
2551  * append the results.
2552  *
2553  * PARTITIONWISE_AGGREGATE_PARTIAL: Partially aggregate each partition
2554  * separately, append the results, and then finalize aggregation.
2555  */
2556 typedef enum
2557 {
2562 
2563 /*
2564  * Struct for extra information passed to subroutines of create_grouping_paths
2565  *
2566  * flags indicating what kinds of grouping are possible.
2567  * partial_costs_set is true if the agg_partial_costs and agg_final_costs
2568  * have been initialized.
2569  * agg_partial_costs gives partial aggregation costs.
2570  * agg_final_costs gives finalization costs.
2571  * target_parallel_safe is true if target is parallel safe.
2572  * havingQual gives list of quals to be applied after aggregation.
2573  * targetList gives list of columns to be projected.
2574  * patype is the type of partitionwise aggregation that is being performed.
2575  */
2576 typedef struct
2577 {
2578  /* Data which remains constant once set. */
2579  int flags;
2583 
2584  /* Data which may differ across partitions. */
2590 
2591 /*
2592  * Struct for extra information passed to subroutines of grouping_planner
2593  *
2594  * limit_needed is true if we actually need a Limit plan node.
2595  * limit_tuples is an estimated bound on the number of output tuples,
2596  * or -1 if no LIMIT or couldn't estimate.
2597  * count_est and offset_est are the estimated values of the LIMIT and OFFSET
2598  * expressions computed by preprocess_limit() (see comments for
2599  * preprocess_limit() for more information).
2600  */
2601 typedef struct
2602 {
2605  int64 count_est;
2606  int64 offset_est;
2608 
2609 /*
2610  * For speed reasons, cost estimation for join paths is performed in two
2611  * phases: the first phase tries to quickly derive a lower bound for the
2612  * join cost, and then we check if that's sufficient to reject the path.
2613  * If not, we come back for a more refined cost estimate. The first phase
2614  * fills a JoinCostWorkspace struct with its preliminary cost estimates
2615  * and possibly additional intermediate values. The second phase takes
2616  * these values as inputs to avoid repeating work.
2617  *
2618  * (Ideally we'd declare this in cost.h, but it's also needed in pathnode.h,
2619  * so seems best to put it here.)
2620  */
2621 typedef struct JoinCostWorkspace
2622 {
2623  /* Preliminary cost estimates --- must not be larger than final ones! */
2624  Cost startup_cost; /* cost expended before fetching any tuples */
2625  Cost total_cost; /* total cost (assuming all tuples fetched) */
2626 
2627  /* Fields below here should be treated as private to costsize.c */
2628  Cost run_cost; /* non-startup cost components */
2629 
2630  /* private for cost_nestloop code */
2631  Cost inner_run_cost; /* also used by cost_mergejoin code */
2633 
2634  /* private for cost_mergejoin code */
2635  double outer_rows;
2636  double inner_rows;
2639 
2640  /* private for cost_hashjoin code */
2645 
2646 /*
2647  * AggInfo holds information about an aggregate that needs to be computed.
2648  * Multiple Aggrefs in a query can refer to the same AggInfo by having the
2649  * same 'aggno' value, so that the aggregate is computed only once.
2650  */
2651 typedef struct AggInfo
2652 {
2653  /*
2654  * Link to an Aggref expr this state value is for.
2655  *
2656  * There can be multiple identical Aggref's sharing the same per-agg. This
2657  * points to the first one of them.
2658  */
2660 
2661  int transno;
2662 
2663  /*
2664  * "shareable" is false if this agg cannot share state values with other
2665  * aggregates because the final function is read-write.
2666  */
2668 
2669  /* Oid of the final function or InvalidOid */
2671 
2672 } AggInfo;
2673 
2674 /*
2675  * AggTransInfo holds information about transition state that is used by one
2676  * or more aggregates in the query. Multiple aggregates can share the same
2677  * transition state, if they have the same inputs and the same transition
2678  * function. Aggrefs that share the same transition info have the same
2679  * 'aggtransno' value.
2680  */
2681 typedef struct AggTransInfo
2682 {
2685 
2686  /* Oid of the state transition function */
2688 
2689  /* Oid of the serialization function or InvalidOid */
2691 
2692  /* Oid of the deserialization function or InvalidOid */
2694 
2695  /* Oid of the combine function or InvalidOid */
2697 
2698  /* Oid of state value's datatype */
2704 
2705  /*
2706  * initial value from pg_aggregate entry
2707  */
2710 
2711 } AggTransInfo;
2712 
2713 #endif /* PATHNODES_H */
QualCost eval_cost
Definition: pathnodes.h:2085
bool has_eclass_joins
Definition: pathnodes.h:746
Oid serialfn_oid
Definition: pathnodes.h:2690
struct RowIdentityVarInfo RowIdentityVarInfo
struct TidPath TidPath
struct Path * cheapest_unique_path
Definition: pathnodes.h:695
NodeTag type
Definition: pathnodes.h:1781
List * indexorderbycols
Definition: pathnodes.h:1240
signed short int16
Definition: c.h:428
char maxParallelHazard
Definition: pathnodes.h:129
List * group_pathkeys
Definition: pathnodes.h:295
struct ProjectionPath ProjectionPath
struct UpperUniquePath UpperUniquePath
List * rowMarks
Definition: pathnodes.h:287
struct QualCost QualCost
Relids all_result_relids
Definition: pathnodes.h:275
Relids ph_needed
Definition: pathnodes.h:2404
List * qual
Definition: pathnodes.h:1733
Definition: fmgr.h:56
Selectivity leftendsel
Definition: pathnodes.h:2148
List * path_mergeclauses
Definition: pathnodes.h:1638
UpperRelationKind
Definition: pathnodes.h:67
int join_cur_level
Definition: pathnodes.h:239
List * outersortkeys
Definition: pathnodes.h:1639
List * distinctList
Definition: pathnodes.h:1833
List * unique_for_rels
Definition: pathnodes.h:735
struct HashPath HashPath
JoinPath jpath
Definition: pathnodes.h:1656
Oid finalfn_oid
Definition: pathnodes.h:2670
PathTarget * pathtarget
Definition: pathnodes.h:1175
Query * parse
Definition: pathnodes.h:161
List * statlist
Definition: pathnodes.h:714
LimitOption limitOption
Definition: pathnodes.h:1897
List * returningLists
Definition: pathnodes.h:1882
struct EquivalenceMember EquivalenceMember
Index security_level
Definition: pathnodes.h:2060
OnConflictExpr * onconflict
Definition: pathnodes.h:1884
struct StatisticExtInfo StatisticExtInfo
List * groupClause
Definition: pathnodes.h:1782
Node * limitOffset
Definition: pathnodes.h:1895
Path path
Definition: pathnodes.h:1236
NodeTag type
Definition: pathnodes.h:2287
Path * subpath
Definition: pathnodes.h:1705
Relids ph_eval_at
Definition: pathnodes.h:2402
List * plan_params
Definition: pathnodes.h:175
PlaceHolderVar * ph_var
Definition: pathnodes.h:2401
IndexOptInfo * indexinfo
Definition: pathnodes.h:1237
SemiAntiJoinFactors semifactors
Definition: pathnodes.h:2522
Index nominalRelation
Definition: pathnodes.h:1876
Oid * indexcollations
Definition: pathnodes.h:844
bool hasJoinRTEs
Definition: pathnodes.h:345
Path * fdw_outerpath
Definition: pathnodes.h:1391
RelOptKind reloptkind
Definition: pathnodes.h:673
VolatileFunctionStatus
Definition: pathnodes.h:1069
Relids * attr_needed
Definition: pathnodes.h:709
bool ec_merging_done
Definition: pathnodes.h:250
PartitionwiseAggregateType
Definition: pathnodes.h:2556
List * custom_paths
Definition: pathnodes.h:1421
List * query_pathkeys
Definition: pathnodes.h:293
int num_batches
Definition: pathnodes.h:1658
List * join_info_list
Definition: pathnodes.h:265
Relids required_relids
Definition: pathnodes.h:2066
SetOpStrategy strategy
Definition: pathnodes.h:1832
Relids min_righthand
Definition: pathnodes.h:2242
AggStrategy aggstrategy
Definition: pathnodes.h:1760
bool materialize_inner
Definition: pathnodes.h:1642
void * join_search_private
Definition: pathnodes.h:371
int num_child_cols
Definition: pathnodes.h:2331
Selectivity right_mcvfreq
Definition: pathnodes.h:2112
Relids curOuterRels
Definition: pathnodes.h:367
List * qual
Definition: pathnodes.h:1765
PlannerInfo * parent_root
Definition: pathnodes.h:167
bool leakproof
Definition: pathnodes.h:2055
double limit_tuples
Definition: pathnodes.h:1447
Index ec_min_security
Definition: pathnodes.h:991
Expr * orclause
Definition: pathnodes.h:2079
Selectivity outer_match_frac
Definition: pathnodes.h:2499
Path * innerjoinpath
Definition: pathnodes.h:1583
struct IncrementalSortPath IncrementalSortPath
List * indextlist
Definition: pathnodes.h:858
AttrNumber * parent_colnos
Definition: pathnodes.h:2332
struct Path * cheapest_startup_path
Definition: pathnodes.h:693
Oid userid
Definition: pathnodes.h:728
QualCost finalCost
Definition: pathnodes.h:59
struct PartitionSchemeData PartitionSchemeData
Relids em_nullable_relids
Definition: pathnodes.h:1031
int lastPlanNodeId
Definition: pathnodes.h:119
double tuples
Definition: pathnodes.h:716
Oid reltablespace
Definition: pathnodes.h:705
Path * subpath
Definition: pathnodes.h:1830
struct RollupData RollupData
List * baserestrictinfo
Definition: pathnodes.h:740
NodeTag type
Definition: pathnodes.h:1170
List * ec_derives
Definition: pathnodes.h:983
struct BitmapOrPath BitmapOrPath
AggClauseCosts agg_partial_costs
Definition: pathnodes.h:2581
Relids clause_relids
Definition: pathnodes.h:2063
struct UniquePath UniquePath
Param * param
Definition: pathnodes.h:2423
struct AppendPath AppendPath
int parallel_workers
Definition: pathnodes.h:1181
bool pseudoconstant
Definition: pathnodes.h:2053
bool consider_param_startup
Definition: pathnodes.h:683
RelOptKind
Definition: pathnodes.h:634
List * resultRelations
Definition: pathnodes.h:105
bool is_hashed
Definition: pathnodes.h:1787
ParamPathInfo * param_info
Definition: pathnodes.h:1177
Definition: nodes.h:539
List * part_schemes
Definition: pathnodes.h:300
PartitionwiseAggregateType patype
Definition: pathnodes.h:2588
List * appendRelations
Definition: pathnodes.h:107
Oid * sortopfamily
Definition: pathnodes.h:847
struct MergeAppendPath MergeAppendPath
struct BitmapAndPath BitmapAndPath
List * partial_pathlist
Definition: pathnodes.h:692
Oid reltablespace
Definition: pathnodes.h:831
Relids left_relids
Definition: pathnodes.h:2075
List * join_rel_list
Definition: pathnodes.h:228
struct CustomPath CustomPath
struct AggClauseCosts AggClauseCosts
bool ec_below_outer_join
Definition: pathnodes.h:988
uint32 flags
Definition: pathnodes.h:1419
uint32 BlockNumber
Definition: block.h:31
struct JoinPathExtraData JoinPathExtraData
EquivalenceClass * right_ec
Definition: pathnodes.h:2097
List * cheapest_parameterized_paths
Definition: pathnodes.h:696
List * minmax_aggs
Definition: pathnodes.h:332
bool single_copy
Definition: pathnodes.h:1553
bool hypothetical
Definition: pathnodes.h:869
Index baserestrict_min_security
Definition: pathnodes.h:742
UniquePathMethod umethod
Definition: pathnodes.h:1539
struct GatherPath GatherPath
Path * subpath
Definition: pathnodes.h:1494
bool transtypeByVal
Definition: pathnodes.h:2702
List * indexclauses
Definition: pathnodes.h:1238
NodeTag type
Definition: pathnodes.h:671
Relids all_partrels
Definition: pathnodes.h:765
Expr * aggfilter
Definition: pathnodes.h:2684
double Selectivity
Definition: nodes.h:672
Oid combinefn_oid
Definition: pathnodes.h:2696
List * agginfos
Definition: pathnodes.h:356
Index ec_max_security
Definition: pathnodes.h:992
bool useridiscurrent
Definition: pathnodes.h:729
AggSplit aggsplit
Definition: pathnodes.h:1761
bool immediate
Definition: pathnodes.h:868
QualCost transCost
Definition: pathnodes.h:58
Selectivity bitmapselectivity
Definition: pathnodes.h:1323
double tuples
Definition: pathnodes.h:836
unsigned int Oid
Definition: postgres_ext.h:31
NodeTag
Definition: nodes.h:26
List * quals
Definition: pathnodes.h:1811
List ** nullable_partexprs
Definition: pathnodes.h:767
struct ForeignKeyOptInfo ForeignKeyOptInfo
Definition: primnodes.h:186
AttrNumber * grouping_map
Definition: pathnodes.h:331
List * fkey_list
Definition: pathnodes.h:291
int tree_height
Definition: pathnodes.h:837
double inner_rows_total
Definition: pathnodes.h:1659
bool hasRecursion
Definition: pathnodes.h:351
struct PlaceHolderInfo PlaceHolderInfo
double numGroups
Definition: pathnodes.h:1762
double numGroups
Definition: pathnodes.h:1836
List * mergeopfamilies
Definition: pathnodes.h:2093
List * translated_vars
Definition: pathnodes.h:2323
struct AppendRelInfo AppendRelInfo
SetOpStrategy
Definition: nodes.h:820
Cost inner_rescan_run_cost
Definition: pathnodes.h:2632
struct EquivalenceClass EquivalenceClass
Oid parent_reltype
Definition: pathnodes.h:2304
Relids syn_lefthand
Definition: pathnodes.h:2243
List * rowMarks
Definition: pathnodes.h:1859
int pk_strategy
Definition: pathnodes.h:1060
double numGroups
Definition: pathnodes.h:1785
Cost startup
Definition: pathnodes.h:45
double allvisfrac
Definition: pathnodes.h:717
Relids outer_relids
Definition: pathnodes.h:2069
int transtypeLen
Definition: pathnodes.h:2701
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:1322
Selectivity norm_selec
Definition: pathnodes.h:2086
List * custom_private
Definition: pathnodes.h:1422
uint64 transitionSpace
Definition: pathnodes.h:1801
JoinType
Definition: nodes.h:706
int first_partial_path
Definition: pathnodes.h:1446
WindowClause * winclause
Definition: pathnodes.h:1821
struct MaterialPath MaterialPath
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:185
List * bitmapquals
Definition: pathnodes.h:1335
int num_workers
Definition: pathnodes.h:1554
List * multiexpr_params
Definition: pathnodes.h:245
BlockNumber pages
Definition: pathnodes.h:835
NodeTag pathtype
Definition: pathnodes.h:1172
Relids syn_righthand
Definition: pathnodes.h:2244
List * subpaths
Definition: pathnodes.h:1444
PlannerInfo * subroot
Definition: pathnodes.h:720
NodeTag type
Definition: pathnodes.h:1056
SetOpCmd cmd
Definition: pathnodes.h:1831
struct LockRowsPath LockRowsPath
List * tidrangequals
Definition: pathnodes.h:1361
bool dependsOnRole
Definition: pathnodes.h:123
bool consider_startup
Definition: pathnodes.h:682
Definition: dynahash.c:219
struct ParamPathInfo ParamPathInfo
Relids lateral_relids
Definition: pathnodes.h:701
Cost per_tuple
Definition: pathnodes.h:46
const struct CustomPathMethods * methods
Definition: pathnodes.h:1423
uint32 amflags
Definition: pathnodes.h:723
int wt_param_id
Definition: pathnodes.h:363
double tuple_fraction
Definition: pathnodes.h:339
Path * subpath
Definition: pathnodes.h:1820
bool skip_mark_restore
Definition: pathnodes.h:1641
RelOptInfo * rel
Definition: pathnodes.h:832
bool amoptionalkey
Definition: pathnodes.h:873
SpecialJoinInfo * sjinfo
Definition: pathnodes.h:2521
struct GroupingSetData GroupingSetData
List ** partexprs
Definition: pathnodes.h:766
bool parallelModeNeeded
Definition: pathnodes.h:127
Relids all_baserels
Definition: pathnodes.h:209
bool pk_nulls_first
Definition: pathnodes.h:1061
List * paramExecTypes
Definition: pathnodes.h:113
Relids param_source_rels
Definition: pathnodes.h:2523
List * row_identity_vars
Definition: pathnodes.h:285
NodeTag type
Definition: pathnodes.h:1131
double limit_tuples
Definition: pathnodes.h:340
struct PathKey PathKey
EquivalenceMember * left_em
Definition: pathnodes.h:2098
struct AggPath AggPath
Cost indextotalcost
Definition: pathnodes.h:1242
Cost startup_cost
Definition: pathnodes.h:1185
List * semi_rhs_exprs
Definition: pathnodes.h:2252
NodeTag type
Definition: pathnodes.h:1101
bool hasLateralRTEs
Definition: pathnodes.h:346
List * indexcols
Definition: pathnodes.h:1287
Path * subpath
Definition: pathnodes.h:1894
struct ModifyTablePath ModifyTablePath
List * joinrestrictinfo
Definition: pathnodes.h:1585
bool parallelModeOK
Definition: pathnodes.h:125
List * aggtransinfos
Definition: pathnodes.h:357
EquivalenceClass * parent_ec
Definition: pathnodes.h:2082
bool partColsUpdated
Definition: pathnodes.h:1878
struct GatherMergePath GatherMergePath
RTEKind
Definition: parsenodes.h:976
Bitmapset * rewindPlanIDs
Definition: pathnodes.h:99
RelOptInfo * parent
Definition: pathnodes.h:1174
AttrNumber indexcol
Definition: pathnodes.h:1286
bool hasAlternativeSubPlans
Definition: pathnodes.h:350
List * uniq_exprs
Definition: pathnodes.h:1541
Path * bitmapqual
Definition: pathnodes.h:1310
bool initValueIsNull
Definition: pathnodes.h:2709
struct ForeignPath ForeignPath
bool outerjoin_delayed
Definition: pathnodes.h:2049
Path path
Definition: pathnodes.h:1730
int numOrderedAggs
Definition: pathnodes.h:358
bool hasNonSerialAggs
Definition: pathnodes.h:360
List * ec_sources
Definition: pathnodes.h:982
struct Path * cheapest_total_path
Definition: pathnodes.h:694
Selectivity rightstartsel
Definition: pathnodes.h:2149
List * curOuterParams
Definition: pathnodes.h:368
struct RelOptInfo RelOptInfo
struct JoinPath JoinPath
int32 aggtransspace
Definition: pathnodes.h:2703
Selectivity indexselectivity
Definition: pathnodes.h:1243
List * subplans
Definition: pathnodes.h:95
bool amcanorderbyop
Definition: pathnodes.h:872
struct RestrictInfo * rinfo
Definition: pathnodes.h:1283
List * joininfo
Definition: pathnodes.h:744
Relids ec_relids
Definition: pathnodes.h:984
PlannerGlobal * glob
Definition: pathnodes.h:163
bool outer_is_left
Definition: pathnodes.h:2103
bool partColsUpdated
Definition: pathnodes.h:374
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:731
List * left_join_clauses
Definition: pathnodes.h:254
int nparts
Definition: pathnodes.h:756
struct AggTransInfo AggTransInfo
ScanDirection
Definition: sdir.h:22
List * full_join_clauses
Definition: pathnodes.h:262
List * groupClause
Definition: pathnodes.h:1764
Index * sortgrouprefs
Definition: pathnodes.h:1103
List * mergeclause_list
Definition: pathnodes.h:2519
struct Path Path
unsigned int uint32
Definition: c.h:441
AttrNumber flagColIdx
Definition: pathnodes.h:1834
Relids relids
Definition: pathnodes.h:676
AggStrategy aggstrategy
Definition: pathnodes.h:1798
Selectivity outer_selec
Definition: pathnodes.h:2089
Path * subpath
Definition: pathnodes.h:1552
struct GroupingSetsPath GroupingSetsPath
double total_table_pages
Definition: pathnodes.h:336
Selectivity bitmapselectivity
Definition: pathnodes.h:1336
struct ResultCachePath ResultCachePath
bool partbounds_merged
Definition: pathnodes.h:760
RelOptInfo * rel
Definition: pathnodes.h:929
struct MinMaxAggPath MinMaxAggPath
int simple_rel_array_size
Definition: pathnodes.h:186
bool shareable
Definition: pathnodes.h:2667
Oid aggtranstype
Definition: pathnodes.h:2699
bool amhasgetbitmap
Definition: pathnodes.h:877
List * canon_pathkeys
Definition: pathnodes.h:252
struct PartitionSchemeData * PartitionScheme
Definition: pathnodes.h:417
List * non_unique_for_rels
Definition: pathnodes.h:737
List * indexquals
Definition: pathnodes.h:1284
VolatileFunctionStatus has_volatile
Definition: pathnodes.h:2057
List * ppilist
Definition: pathnodes.h:691
Index relid
Definition: pathnodes.h:704
Oid hasheqoperator
Definition: pathnodes.h:2115
List * sort_pathkeys
Definition: pathnodes.h:298
struct PlaceHolderVar PlaceHolderVar
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:193
EquivalenceMember * right_em
Definition: pathnodes.h:2099
Relids lateral_referencers
Definition: pathnodes.h:712
Expr * clause
Definition: pathnodes.h:2045
Path * subpath
Definition: pathnodes.h:1858
struct PlannerGlobal PlannerGlobal
int32 aggtranstypmod
Definition: pathnodes.h:2700
Oid serverid
Definition: pathnodes.h:727
List * ec_opfamilies
Definition: pathnodes.h:979
List * exprs
Definition: pathnodes.h:1102
List * window_pathkeys
Definition: pathnodes.h:296
List * indrestrictinfo
Definition: pathnodes.h:860
Relids direct_lateral_relids
Definition: pathnodes.h:700
Path * outerjoinpath
Definition: pathnodes.h:1582
struct MergeScanSelCache MergeScanSelCache
List * invalItems
Definition: pathnodes.h:111
struct MergePath MergePath
struct GroupResultPath GroupResultPath
bool consider_partitionwise_join
Definition: pathnodes.h:749
NodeTag type
Definition: pathnodes.h:159
JoinPath NestPath
Definition: pathnodes.h:1598
Datum initValue
Definition: pathnodes.h:2708
Relids nullable_relids
Definition: pathnodes.h:2072
double inner_rows_total
Definition: pathnodes.h:2643
bool delay_upper_joins
Definition: pathnodes.h:2247
int transno
Definition: pathnodes.h:2661
List * indexorderbys
Definition: pathnodes.h:1239
uintptr_t Datum
Definition: postgres.h:411
struct RestrictInfo RestrictInfo
struct ProjectSetPath ProjectSetPath
struct IndexClause IndexClause
int rel_parallel_workers
Definition: pathnodes.h:722
List * groupClause
Definition: pathnodes.h:1732
List * append_rel_list
Definition: pathnodes.h:283
struct SemiAntiJoinFactors SemiAntiJoinFactors
struct LimitPath LimitPath
struct AppendRelInfo ** append_rel_array
Definition: pathnodes.h:201
Index lastPHId
Definition: pathnodes.h:115
List * cte_plan_ids
Definition: pathnodes.h:243
List * mmaggregates
Definition: pathnodes.h:1810
Relids ph_lateral
Definition: pathnodes.h:2403
struct PartitionBoundInfoData * boundinfo
Definition: pathnodes.h:759
List * tidquals
Definition: pathnodes.h:1349
Path * subpath
Definition: pathnodes.h:1731
unsigned int Index
Definition: c.h:549
struct GroupPath GroupPath
RTEKind rtekind
Definition: pathnodes.h:706
List * indexlist
Definition: pathnodes.h:713
List * init_plans
Definition: pathnodes.h:241
List * in_operators
Definition: pathnodes.h:1540
double rows
Definition: pathnodes.h:679
bool hasPseudoConstantQuals
Definition: pathnodes.h:348
bool amhasgettuple
Definition: pathnodes.h:876
List * distinct_pathkeys
Definition: pathnodes.h:297
List * hash_operators
Definition: pathnodes.h:1506
List * args
Definition: pathnodes.h:2683
bool is_pushed_down
Definition: pathnodes.h:2047
void * fdw_private
Definition: pathnodes.h:732
VolatileFunctionStatus has_volatile_expr
Definition: pathnodes.h:1106
Cost total_cost
Definition: pathnodes.h:1186
NodeTag type
Definition: pathnodes.h:828
CostSelector
Definition: pathnodes.h:34
Selectivity left_bucketsize
Definition: pathnodes.h:2109
int firstFlag
Definition: pathnodes.h:1835
double outer_skip_rows
Definition: pathnodes.h:2637
List * pathkeys
Definition: pathnodes.h:1188
Relids right_relids
Definition: pathnodes.h:2076
uint64 transitionSpace
Definition: pathnodes.h:1763
BlockNumber pages
Definition: pathnodes.h:715
Path path
Definition: pathnodes.h:1575
struct BitmapHeapPath BitmapHeapPath
ParamListInfo boundParams
Definition: pathnodes.h:93
Expr * target
Definition: pathnodes.h:2419
List * eq_classes
Definition: pathnodes.h:248
List ** join_rel_level
Definition: pathnodes.h:238
UniquePathMethod
Definition: pathnodes.h:1528
NodeTag type
Definition: pathnodes.h:91
Path * subpath
Definition: pathnodes.h:1691
double rows
Definition: pathnodes.h:1184
bool parallel_safe
Definition: pathnodes.h:1180
List * lateral_vars
Definition: pathnodes.h:711
struct WindowAggPath WindowAggPath
struct PlannerParamItem PlannerParamItem
struct FmgrInfo * partsupfunc
Definition: pathnodes.h:414
Index rootRelation
Definition: pathnodes.h:1877
JoinType jointype
Definition: pathnodes.h:2245
EquivalenceClass * pk_eclass
Definition: pathnodes.h:1058
Bitmapset * outer_params
Definition: pathnodes.h:176
Selectivity left_mcvfreq
Definition: pathnodes.h:2111
List * ppi_clauses
Definition: pathnodes.h:1135
struct RelOptInfo ** part_rels
Definition: pathnodes.h:763
struct Path * non_recursive_path
Definition: pathnodes.h:364
#define INDEX_MAX_KEYS
size_t Size
Definition: c.h:540
Oid hashjoinoperator
Definition: pathnodes.h:2106
NodeTag type
Definition: pathnodes.h:2043
QualCost cost
Definition: pathnodes.h:1104
AggSplit
Definition: nodes.h:790
bool ec_has_volatile
Definition: pathnodes.h:987
List * relationOids
Definition: pathnodes.h:109
List * subroots
Definition: pathnodes.h:97
bool amsearcharray
Definition: pathnodes.h:874
struct HTAB * join_rel_hash
Definition: pathnodes.h:229
bool inner_unique
Definition: pathnodes.h:1579
Index qual_security_level
Definition: pathnodes.h:342
Oid deserialfn_oid
Definition: pathnodes.h:2693
bool consider_parallel
Definition: pathnodes.h:684
int nkeycolumns
Definition: pathnodes.h:841
List * innersortkeys
Definition: pathnodes.h:1640
Path * subpath
Definition: pathnodes.h:1759
Oid * opcintype
Definition: pathnodes.h:846
LimitOption
Definition: nodes.h:845
Bitmapset * Relids
Definition: pathnodes.h:28
Index query_level
Definition: pathnodes.h:165
Oid pk_opfamily
Definition: pathnodes.h:1059
double ppi_rows
Definition: pathnodes.h:1134
Path path
Definition: pathnodes.h:1893
Path path
Definition: pathnodes.h:1348
bool amcanmarkpos
Definition: pathnodes.h:879
Oid * opfamily
Definition: pathnodes.h:845
List * withCheckOptionLists
Definition: pathnodes.h:1881
List * finalrtable
Definition: pathnodes.h:101
AggStrategy
Definition: nodes.h:768
Bitmapset * keys
Definition: pathnodes.h:931
Index phlevelsup
Definition: pathnodes.h:2173
Index lastRowMarkId
Definition: pathnodes.h:117
AttrNumber max_attr
Definition: pathnodes.h:708
Selectivity match_count
Definition: pathnodes.h:2500
Selectivity right_bucketsize
Definition: pathnodes.h:2110
EquivalenceClass * left_ec
Definition: pathnodes.h:2096
struct JoinCostWorkspace JoinCostWorkspace
Relids nullable_baserels
Definition: pathnodes.h:217
struct RecursiveUnionPath RecursiveUnionPath
List * fdw_private
Definition: pathnodes.h:1392
struct TidRangePath TidRangePath
SetOpCmd
Definition: nodes.h:812
JoinType jointype
Definition: pathnodes.h:1577
List * semi_operators
Definition: pathnodes.h:2251
ScanDirection indexscandir
Definition: pathnodes.h:1241
CmdType operation
Definition: pathnodes.h:1874
struct MinMaxAggInfo MinMaxAggInfo
struct SubqueryScanPath SubqueryScanPath
Relids leaf_result_relids
Definition: pathnodes.h:276
List * placeholder_list
Definition: pathnodes.h:289
List * resultRelations
Definition: pathnodes.h:1879
Size transitionSpace
Definition: pathnodes.h:60
double numGroups
Definition: pathnodes.h:1776
bool hashable
Definition: pathnodes.h:1786
List * param_exprs
Definition: pathnodes.h:1507
bool hasHavingQual
Definition: pathnodes.h:347
JoinPath jpath
Definition: pathnodes.h:1637
PartitionScheme part_scheme
Definition: pathnodes.h:755
uint32 est_entries
Definition: pathnodes.h:1511
List * updateColnosLists
Definition: pathnodes.h:1880
bool parallel_aware
Definition: pathnodes.h:1179
int * indexkeys
Definition: pathnodes.h:842
Definition: c.h:621
List * path_hashclauses
Definition: pathnodes.h:1657
struct PathTarget PathTarget
List * initial_rels
Definition: pathnodes.h:303
List * pathlist
Definition: pathnodes.h:690
Relids ppi_req_outer
Definition: pathnodes.h:1133
MemoryContext planner_cxt
Definition: pathnodes.h:334
bool hasNonPartialAggs
Definition: pathnodes.h:359
List * right_join_clauses
Definition: pathnodes.h:258
Index child_relid
Definition: pathnodes.h:2296
bool * canreturn
Definition: pathnodes.h:851
struct IndexPath IndexPath
bool amsearchnulls
Definition: pathnodes.h:875
List * partition_qual
Definition: pathnodes.h:762
bool * nulls_first
Definition: pathnodes.h:849
struct SetOpPath SetOpPath
Path * subpath
Definition: pathnodes.h:1679
NodeTag type
Definition: pathnodes.h:1282
Index parent_relid
Definition: pathnodes.h:2295
bool * reverse_sort
Definition: pathnodes.h:848
PartitionDirectory partition_directory
Definition: pathnodes.h:131
bytea ** opclassoptions
Definition: pathnodes.h:850
double inner_skip_rows
Definition: pathnodes.h:2638
List * processed_tlist
Definition: pathnodes.h:320
List * indpred
Definition: pathnodes.h:856
int32 * attr_widths
Definition: pathnodes.h:710
AggClauseCosts agg_final_costs
Definition: pathnodes.h:2582
Node * limitCount
Definition: pathnodes.h:1896
List * finalrowmarks
Definition: pathnodes.h:103
struct SortPath SortPath
Definition: pg_list.h:50
Path path
Definition: pathnodes.h:1704
struct PathTarget * reltarget
Definition: pathnodes.h:687
Relids min_lefthand
Definition: pathnodes.h:2241
int16 AttrNumber
Definition: attnum.h:21
QualCost baserestrictcost
Definition: pathnodes.h:741
List * subplan_params
Definition: pathnodes.h:721
Path path
Definition: pathnodes.h:1829
NodeTag type
Definition: pathnodes.h:2415
CmdType
Definition: nodes.h:682
List * gsets_data
Definition: pathnodes.h:1784
Bitmapset * eclass_indexes
Definition: pathnodes.h:718
Path path
Definition: pathnodes.h:1758
double limit_tuples
Definition: pathnodes.h:1469
struct EquivalenceClass * ec_merged
Definition: pathnodes.h:993
Selectivity rightendsel
Definition: pathnodes.h:2150
bool amcanparallel
Definition: pathnodes.h:878
double Cost
Definition: nodes.h:673
Aggref * representative_aggref
Definition: pathnodes.h:2659
List * scansel_cache
Definition: pathnodes.h:2100
struct AggInfo AggInfo
List * update_colnos
Definition: pathnodes.h:328
Selectivity leftstartsel
Definition: pathnodes.h:2147
List * ec_members
Definition: pathnodes.h:981
List * indexprs
Definition: pathnodes.h:855
Relids top_parent_relids
Definition: pathnodes.h:751
bool transientPlan
Definition: pathnodes.h:121
List * gsets
Definition: pathnodes.h:1783
bool is_dummy_rel(RelOptInfo *rel)
Definition: joinrels.c:1212
Path * subpath
Definition: pathnodes.h:1538
PlannerInfo * subroot
Definition: pathnodes.h:2420
AttrNumber min_attr
Definition: pathnodes.h:707