PostgreSQL Source Code  git master
allpaths.c
Go to the documentation of this file.
1 /*-------------------------------------------------------------------------
2  *
3  * allpaths.c
4  * Routines to find possible search paths for processing a query
5  *
6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/optimizer/path/allpaths.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 
16 #include "postgres.h"
17 
18 #include <limits.h>
19 #include <math.h>
20 
21 #include "access/sysattr.h"
22 #include "access/tsmapi.h"
23 #include "catalog/pg_class.h"
24 #include "catalog/pg_operator.h"
25 #include "catalog/pg_proc.h"
26 #include "foreign/fdwapi.h"
27 #include "miscadmin.h"
28 #include "nodes/makefuncs.h"
29 #include "nodes/nodeFuncs.h"
30 #include "nodes/supportnodes.h"
31 #ifdef OPTIMIZER_DEBUG
32 #include "nodes/print.h"
33 #endif
34 #include "optimizer/appendinfo.h"
35 #include "optimizer/clauses.h"
36 #include "optimizer/cost.h"
37 #include "optimizer/geqo.h"
38 #include "optimizer/optimizer.h"
39 #include "optimizer/pathnode.h"
40 #include "optimizer/paths.h"
41 #include "optimizer/plancat.h"
42 #include "optimizer/planner.h"
43 #include "optimizer/tlist.h"
44 #include "parser/parse_clause.h"
45 #include "parser/parsetree.h"
46 #include "partitioning/partbounds.h"
47 #include "port/pg_bitutils.h"
48 #include "rewrite/rewriteManip.h"
49 #include "utils/lsyscache.h"
50 
51 
52 /* Bitmask flags for pushdown_safety_info.unsafeFlags */
53 #define UNSAFE_HAS_VOLATILE_FUNC (1 << 0)
54 #define UNSAFE_HAS_SET_FUNC (1 << 1)
55 #define UNSAFE_NOTIN_DISTINCTON_CLAUSE (1 << 2)
56 #define UNSAFE_NOTIN_PARTITIONBY_CLAUSE (1 << 3)
57 #define UNSAFE_TYPE_MISMATCH (1 << 4)
58 
59 /* results of subquery_is_pushdown_safe */
60 typedef struct pushdown_safety_info
61 {
62  unsigned char *unsafeFlags; /* bitmask of reasons why this target list
63  * column is unsafe for qual pushdown, or 0 if
64  * no reason. */
65  bool unsafeVolatile; /* don't push down volatile quals */
66  bool unsafeLeaky; /* don't push down leaky quals */
67 } pushdown_safety_info;
68 
69 /* Return type for qual_is_pushdown_safe */
70 typedef enum pushdown_safe_type
71 {
72  PUSHDOWN_UNSAFE, /* unsafe to push qual into subquery */
73  PUSHDOWN_SAFE, /* safe to push qual into subquery */
74  PUSHDOWN_WINDOWCLAUSE_RUNCOND, /* unsafe, but may work as WindowClause
75  * run condition */
76 } pushdown_safe_type;
77 
78 /* These parameters are set by GUC */
79 bool enable_geqo = false; /* just in case GUC doesn't set it */
80 int geqo_threshold;
81 int min_parallel_table_scan_size;
82 int min_parallel_index_scan_size;
83 
84 /* Hook for plugins to get control in set_rel_pathlist() */
85 set_rel_pathlist_hook_type set_rel_pathlist_hook = NULL;
86 
87 /* Hook for plugins to replace standard_join_search() */
88 join_search_hook_type join_search_hook = NULL;
89 
90 
91 static void set_base_rel_consider_startup(PlannerInfo *root);
92 static void set_base_rel_sizes(PlannerInfo *root);
93 static void set_base_rel_pathlists(PlannerInfo *root);
94 static void set_rel_size(PlannerInfo *root, RelOptInfo *rel,
95  Index rti, RangeTblEntry *rte);
96 static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
97  Index rti, RangeTblEntry *rte);
98 static void set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel,
99  RangeTblEntry *rte);
100 static void create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel);
101 static void set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
102  RangeTblEntry *rte);
103 static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
104  RangeTblEntry *rte);
105 static void set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel,
106  RangeTblEntry *rte);
107 static void set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
108  RangeTblEntry *rte);
109 static void set_foreign_size(PlannerInfo *root, RelOptInfo *rel,
110  RangeTblEntry *rte);
111 static void set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel,
112  RangeTblEntry *rte);
113 static void set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
114  Index rti, RangeTblEntry *rte);
115 static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
116  Index rti, RangeTblEntry *rte);
117 static void generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel,
118  List *live_childrels,
119  List *all_child_pathkeys);
120 static Path *get_cheapest_parameterized_child_path(PlannerInfo *root,
121  RelOptInfo *rel,
122  Relids required_outer);
123 static void accumulate_append_subpath(Path *path,
124  List **subpaths,
125  List **special_subpaths);
126 static Path *get_singleton_append_subpath(Path *path);
127 static void set_dummy_rel_pathlist(RelOptInfo *rel);
128 static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel,
129  Index rti, RangeTblEntry *rte);
130 static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel,
131  RangeTblEntry *rte);
132 static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel,
133  RangeTblEntry *rte);
134 static void set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel,
135  RangeTblEntry *rte);
136 static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel,
137  RangeTblEntry *rte);
138 static void set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel,
139  RangeTblEntry *rte);
140 static void set_result_pathlist(PlannerInfo *root, RelOptInfo *rel,
141  RangeTblEntry *rte);
142 static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel,
143  RangeTblEntry *rte);
144 static RelOptInfo *make_rel_from_joinlist(PlannerInfo *root, List *joinlist);
145 static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery,
146  pushdown_safety_info *safetyInfo);
147 static bool recurse_pushdown_safe(Node *setOp, Query *topquery,
148  pushdown_safety_info *safetyInfo);
149 static void check_output_expressions(Query *subquery,
150  pushdown_safety_info *safetyInfo);
151 static void compare_tlist_datatypes(List *tlist, List *colTypes,
152  pushdown_safety_info *safetyInfo);
153 static bool targetIsInAllPartitionLists(TargetEntry *tle, Query *query);
154 static pushdown_safe_type qual_is_pushdown_safe(Query *subquery, Index rti,
155  RestrictInfo *rinfo,
156  pushdown_safety_info *safetyInfo);
157 static void subquery_push_qual(Query *subquery,
158  RangeTblEntry *rte, Index rti, Node *qual);
159 static void recurse_push_qual(Node *setOp, Query *topquery,
160  RangeTblEntry *rte, Index rti, Node *qual);
161 static void remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel,
162  Bitmapset *extra_used_attrs);
163 
164 
165 /*
166  * make_one_rel
167  * Finds all possible access paths for executing a query, returning a
168  * single rel that represents the join of all base rels in the query.
169  */
170 RelOptInfo *
171 make_one_rel(PlannerInfo *root, List *joinlist)
172 {
173  RelOptInfo *rel;
174  Index rti;
175  double total_pages;
176 
177  /* Mark base rels as to whether we care about fast-start plans */
178  set_base_rel_consider_startup(root);
179 
180  /*
181  * Compute size estimates and consider_parallel flags for each base rel.
182  */
183  set_base_rel_sizes(root);
184 
185  /*
186  * We should now have size estimates for every actual table involved in
187  * the query, and we also know which if any have been deleted from the
188  * query by join removal, pruned by partition pruning, or eliminated by
189  * constraint exclusion. So we can now compute total_table_pages.
190  *
191  * Note that appendrels are not double-counted here, even though we don't
192  * bother to distinguish RelOptInfos for appendrel parents, because the
193  * parents will have pages = 0.
194  *
195  * XXX if a table is self-joined, we will count it once per appearance,
196  * which perhaps is the wrong thing ... but that's not completely clear,
197  * and detecting self-joins here is difficult, so ignore it for now.
198  */
199  total_pages = 0;
200  for (rti = 1; rti < root->simple_rel_array_size; rti++)
201  {
202  RelOptInfo *brel = root->simple_rel_array[rti];
203 
204  /* there may be empty slots corresponding to non-baserel RTEs */
205  if (brel == NULL)
206  continue;
207 
208  Assert(brel->relid == rti); /* sanity check on array */
209 
210  if (IS_DUMMY_REL(brel))
211  continue;
212 
213  if (IS_SIMPLE_REL(brel))
214  total_pages += (double) brel->pages;
215  }
216  root->total_table_pages = total_pages;
217 
218  /*
219  * Generate access paths for each base rel.
220  */
221  set_base_rel_pathlists(root);
222 
223  /*
224  * Generate access paths for the entire join tree.
225  */
226  rel = make_rel_from_joinlist(root, joinlist);
227 
228  /*
229  * The result should join all and only the query's base + outer-join rels.
230  */
231  Assert(bms_equal(rel->relids, root->all_query_rels));
232 
233  return rel;
234 }
235 
236 /*
237  * set_base_rel_consider_startup
238  * Set the consider_[param_]startup flags for each base-relation entry.
239  *
240  * For the moment, we only deal with consider_param_startup here; because the
241  * logic for consider_startup is pretty trivial and is the same for every base
242  * relation, we just let build_simple_rel() initialize that flag correctly to
243  * start with. If that logic ever gets more complicated it would probably
244  * be better to move it here.
245  */
246 static void
247 set_base_rel_consider_startup(PlannerInfo *root)
248 {
249  /*
250  * Since parameterized paths can only be used on the inside of a nestloop
251  * join plan, there is usually little value in considering fast-start
252  * plans for them. However, for relations that are on the RHS of a SEMI
253  * or ANTI join, a fast-start plan can be useful because we're only going
254  * to care about fetching one tuple anyway.
255  *
256  * To minimize growth of planning time, we currently restrict this to
257  * cases where the RHS is a single base relation, not a join; there is no
258  * provision for consider_param_startup to get set at all on joinrels.
259  * Also we don't worry about appendrels. costsize.c's costing rules for
260  * nestloop semi/antijoins don't consider such cases either.
261  */
262  ListCell *lc;
263 
264  foreach(lc, root->join_info_list)
265  {
266  SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
267  int varno;
268 
269  if ((sjinfo->jointype == JOIN_SEMI || sjinfo->jointype == JOIN_ANTI) &&
270  bms_get_singleton_member(sjinfo->syn_righthand, &varno))
271  {
272  RelOptInfo *rel = find_base_rel(root, varno);
273 
274  rel->consider_param_startup = true;
275  }
276  }
277 }
278 
279 /*
280  * set_base_rel_sizes
281  * Set the size estimates (rows and widths) for each base-relation entry.
282  * Also determine whether to consider parallel paths for base relations.
283  *
284  * We do this in a separate pass over the base rels so that rowcount
285  * estimates are available for parameterized path generation, and also so
286  * that each rel's consider_parallel flag is set correctly before we begin to
287  * generate paths.
288  */
289 static void
290 set_base_rel_sizes(PlannerInfo *root)
291 {
292  Index rti;
293 
294  for (rti = 1; rti < root->simple_rel_array_size; rti++)
295  {
296  RelOptInfo *rel = root->simple_rel_array[rti];
297  RangeTblEntry *rte;
298 
299  /* there may be empty slots corresponding to non-baserel RTEs */
300  if (rel == NULL)
301  continue;
302 
303  Assert(rel->relid == rti); /* sanity check on array */
304 
305  /* ignore RTEs that are "other rels" */
306  if (rel->reloptkind != RELOPT_BASEREL)
307  continue;
308 
309  rte = root->simple_rte_array[rti];
310 
311  /*
312  * If parallelism is allowable for this query in general, see whether
313  * it's allowable for this rel in particular. We have to do this
314  * before set_rel_size(), because (a) if this rel is an inheritance
315  * parent, set_append_rel_size() will use and perhaps change the rel's
316  * consider_parallel flag, and (b) for some RTE types, set_rel_size()
317  * goes ahead and makes paths immediately.
318  */
319  if (root->glob->parallelModeOK)
320  set_rel_consider_parallel(root, rel, rte);
321 
322  set_rel_size(root, rel, rti, rte);
323  }
324 }
325 
326 /*
327  * set_base_rel_pathlists
328  * Finds all paths available for scanning each base-relation entry.
329  * Sequential scan and any available indices are considered.
330  * Each useful path is attached to its relation's 'pathlist' field.
331  */
332 static void
333 set_base_rel_pathlists(PlannerInfo *root)
334 {
335  Index rti;
336 
337  for (rti = 1; rti < root->simple_rel_array_size; rti++)
338  {
339  RelOptInfo *rel = root->simple_rel_array[rti];
340 
341  /* there may be empty slots corresponding to non-baserel RTEs */
342  if (rel == NULL)
343  continue;
344 
345  Assert(rel->relid == rti); /* sanity check on array */
346 
347  /* ignore RTEs that are "other rels" */
348  if (rel->reloptkind != RELOPT_BASEREL)
349  continue;
350 
351  set_rel_pathlist(root, rel, rti, root->simple_rte_array[rti]);
352  }
353 }
354 
355 /*
356  * set_rel_size
357  * Set size estimates for a base relation
358  */
359 static void
360 set_rel_size(PlannerInfo *root, RelOptInfo *rel,
361  Index rti, RangeTblEntry *rte)
362 {
363  if (rel->reloptkind == RELOPT_BASEREL &&
364  relation_excluded_by_constraints(root, rel, rte))
365  {
366  /*
367  * We proved we don't need to scan the rel via constraint exclusion,
368  * so set up a single dummy path for it. Here we only check this for
369  * regular baserels; if it's an otherrel, CE was already checked in
370  * set_append_rel_size().
371  *
372  * In this case, we go ahead and set up the relation's path right away
373  * instead of leaving it for set_rel_pathlist to do. This is because
374  * we don't have a convention for marking a rel as dummy except by
375  * assigning a dummy path to it.
376  */
377  set_dummy_rel_pathlist(rel);
378  }
379  else if (rte->inh)
380  {
381  /* It's an "append relation", process accordingly */
382  set_append_rel_size(root, rel, rti, rte);
383  }
384  else
385  {
386  switch (rel->rtekind)
387  {
388  case RTE_RELATION:
389  if (rte->relkind == RELKIND_FOREIGN_TABLE)
390  {
391  /* Foreign table */
392  set_foreign_size(root, rel, rte);
393  }
394  else if (rte->relkind == RELKIND_PARTITIONED_TABLE)
395  {
396  /*
397  * We could get here if asked to scan a partitioned table
398  * with ONLY. In that case we shouldn't scan any of the
399  * partitions, so mark it as a dummy rel.
400  */
401  set_dummy_rel_pathlist(rel);
402  }
403  else if (rte->tablesample != NULL)
404  {
405  /* Sampled relation */
406  set_tablesample_rel_size(root, rel, rte);
407  }
408  else
409  {
410  /* Plain relation */
411  set_plain_rel_size(root, rel, rte);
412  }
413  break;
414  case RTE_SUBQUERY:
415 
416  /*
417  * Subqueries don't support making a choice between
418  * parameterized and unparameterized paths, so just go ahead
419  * and build their paths immediately.
420  */
421  set_subquery_pathlist(root, rel, rti, rte);
422  break;
423  case RTE_FUNCTION:
424  set_function_size_estimates(root, rel);
425  break;
426  case RTE_TABLEFUNC:
427  set_tablefunc_size_estimates(root, rel);
428  break;
429  case RTE_VALUES:
430  set_values_size_estimates(root, rel);
431  break;
432  case RTE_CTE:
433 
434  /*
435  * CTEs don't support making a choice between parameterized
436  * and unparameterized paths, so just go ahead and build their
437  * paths immediately.
438  */
439  if (rte->self_reference)
440  set_worktable_pathlist(root, rel, rte);
441  else
442  set_cte_pathlist(root, rel, rte);
443  break;
444  case RTE_NAMEDTUPLESTORE:
445  /* Might as well just build the path immediately */
446  set_namedtuplestore_pathlist(root, rel, rte);
447  break;
448  case RTE_RESULT:
449  /* Might as well just build the path immediately */
450  set_result_pathlist(root, rel, rte);
451  break;
452  default:
453  elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
454  break;
455  }
456  }
457 
458  /*
459  * We insist that all non-dummy rels have a nonzero rowcount estimate.
460  */
461  Assert(rel->rows > 0 || IS_DUMMY_REL(rel));
462 }
463 
464 /*
465  * set_rel_pathlist
466  * Build access paths for a base relation
467  */
468 static void
469 set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
470  Index rti, RangeTblEntry *rte)
471 {
472  if (IS_DUMMY_REL(rel))
473  {
474  /* We already proved the relation empty, so nothing more to do */
475  }
476  else if (rte->inh)
477  {
478  /* It's an "append relation", process accordingly */
479  set_append_rel_pathlist(root, rel, rti, rte);
480  }
481  else
482  {
483  switch (rel->rtekind)
484  {
485  case RTE_RELATION:
486  if (rte->relkind == RELKIND_FOREIGN_TABLE)
487  {
488  /* Foreign table */
489  set_foreign_pathlist(root, rel, rte);
490  }
491  else if (rte->tablesample != NULL)
492  {
493  /* Sampled relation */
494  set_tablesample_rel_pathlist(root, rel, rte);
495  }
496  else
497  {
498  /* Plain relation */
499  set_plain_rel_pathlist(root, rel, rte);
500  }
501  break;
502  case RTE_SUBQUERY:
503  /* Subquery --- fully handled during set_rel_size */
504  break;
505  case RTE_FUNCTION:
506  /* RangeFunction */
507  set_function_pathlist(root, rel, rte);
508  break;
509  case RTE_TABLEFUNC:
510  /* Table Function */
511  set_tablefunc_pathlist(root, rel, rte);
512  break;
513  case RTE_VALUES:
514  /* Values list */
515  set_values_pathlist(root, rel, rte);
516  break;
517  case RTE_CTE:
518  /* CTE reference --- fully handled during set_rel_size */
519  break;
520  case RTE_NAMEDTUPLESTORE:
521  /* tuplestore reference --- fully handled during set_rel_size */
522  break;
523  case RTE_RESULT:
524  /* simple Result --- fully handled during set_rel_size */
525  break;
526  default:
527  elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
528  break;
529  }
530  }
531 
532  /*
533  * Allow a plugin to editorialize on the set of Paths for this base
534  * relation. It could add new paths (such as CustomPaths) by calling
535  * add_path(), or add_partial_path() if parallel aware. It could also
536  * delete or modify paths added by the core code.
537  */
538  if (set_rel_pathlist_hook)
539  (*set_rel_pathlist_hook) (root, rel, rti, rte);
540 
541  /*
542  * If this is a baserel, we should normally consider gathering any partial
543  * paths we may have created for it. We have to do this after calling the
544  * set_rel_pathlist_hook, else it cannot add partial paths to be included
545  * here.
546  *
547  * However, if this is an inheritance child, skip it. Otherwise, we could
548  * end up with a very large number of gather nodes, each trying to grab
549  * its own pool of workers. Instead, we'll consider gathering partial
550  * paths for the parent appendrel.
551  *
552  * Also, if this is the topmost scan/join rel, we postpone gathering until
553  * the final scan/join targetlist is available (see grouping_planner).
554  */
555  if (rel->reloptkind == RELOPT_BASEREL &&
556  !bms_equal(rel->relids, root->all_query_rels))
557  generate_useful_gather_paths(root, rel, false);
558 
559  /* Now find the cheapest of the paths for this rel */
560  set_cheapest(rel);
561 
562 #ifdef OPTIMIZER_DEBUG
563  pprint(rel);
564 #endif
565 }
566 
567 /*
568  * set_plain_rel_size
569  * Set size estimates for a plain relation (no subquery, no inheritance)
570  */
571 static void
572 set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
573 {
574  /*
575  * Test any partial indexes of rel for applicability. We must do this
576  * first since partial unique indexes can affect size estimates.
577  */
578  check_index_predicates(root, rel);
579 
580  /* Mark rel with estimated output rows, width, etc */
581  set_baserel_size_estimates(root, rel);
582 }
583 
584 /*
585  * If this relation could possibly be scanned from within a worker, then set
586  * its consider_parallel flag.
587  */
588 static void
589 set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
590  RangeTblEntry *rte)
591 {
592  /*
593  * The flag has previously been initialized to false, so we can just
594  * return if it becomes clear that we can't safely set it.
595  */
596  Assert(!rel->consider_parallel);
597 
598  /* Don't call this if parallelism is disallowed for the entire query. */
599  Assert(root->glob->parallelModeOK);
600 
601  /* This should only be called for baserels and appendrel children. */
602  Assert(IS_SIMPLE_REL(rel));
603 
604  /* Assorted checks based on rtekind. */
605  switch (rte->rtekind)
606  {
607  case RTE_RELATION:
608 
609  /*
610  * Currently, parallel workers can't access the leader's temporary
611  * tables. We could possibly relax this if we wrote all of its
612  * local buffers at the start of the query and made no changes
613  * thereafter (maybe we could allow hint bit changes), and if we
614  * taught the workers to read them. Writing a large number of
615  * temporary buffers could be expensive, though, and we don't have
616  * the rest of the necessary infrastructure right now anyway. So
617  * for now, bail out if we see a temporary table.
618  */
619  if (get_rel_persistence(rte->relid) == RELPERSISTENCE_TEMP)
620  return;
621 
622  /*
623  * Table sampling can be pushed down to workers if the sample
624  * function and its arguments are safe.
625  */
626  if (rte->tablesample != NULL)
627  {
628  char proparallel = func_parallel(rte->tablesample->tsmhandler);
629 
630  if (proparallel != PROPARALLEL_SAFE)
631  return;
632  if (!is_parallel_safe(root, (Node *) rte->tablesample->args))
633  return;
634  }
635 
636  /*
637  * Ask FDWs whether they can support performing a ForeignScan
638  * within a worker. Most often, the answer will be no. For
639  * example, if the nature of the FDW is such that it opens a TCP
640  * connection with a remote server, each parallel worker would end
641  * up with a separate connection, and these connections might not
642  * be appropriately coordinated between workers and the leader.
643  */
644  if (rte->relkind == RELKIND_FOREIGN_TABLE)
645  {
646  Assert(rel->fdwroutine);
647  if (!rel->fdwroutine->IsForeignScanParallelSafe)
648  return;
649  if (!rel->fdwroutine->IsForeignScanParallelSafe(root, rel, rte))
650  return;
651  }
652 
653  /*
654  * There are additional considerations for appendrels, which we'll
655  * deal with in set_append_rel_size and set_append_rel_pathlist.
656  * For now, just set consider_parallel based on the rel's own
657  * quals and targetlist.
658  */
659  break;
660 
661  case RTE_SUBQUERY:
662 
663  /*
664  * There's no intrinsic problem with scanning a subquery-in-FROM
665  * (as distinct from a SubPlan or InitPlan) in a parallel worker.
666  * If the subquery doesn't happen to have any parallel-safe paths,
667  * then flagging it as consider_parallel won't change anything,
668  * but that's true for plain tables, too. We must set
669  * consider_parallel based on the rel's own quals and targetlist,
670  * so that if a subquery path is parallel-safe but the quals and
671  * projection we're sticking onto it are not, we correctly mark
672  * the SubqueryScanPath as not parallel-safe. (Note that
673  * set_subquery_pathlist() might push some of these quals down
674  * into the subquery itself, but that doesn't change anything.)
675  *
676  * We can't push sub-select containing LIMIT/OFFSET to workers as
677  * there is no guarantee that the row order will be fully
678  * deterministic, and applying LIMIT/OFFSET will lead to
679  * inconsistent results at the top-level. (In some cases, where
680  * the result is ordered, we could relax this restriction. But it
681  * doesn't currently seem worth expending extra effort to do so.)
682  */
683  {
684  Query *subquery = castNode(Query, rte->subquery);
685 
686  if (limit_needed(subquery))
687  return;
688  }
689  break;
690 
691  case RTE_JOIN:
692  /* Shouldn't happen; we're only considering baserels here. */
693  Assert(false);
694  return;
695 
696  case RTE_FUNCTION:
697  /* Check for parallel-restricted functions. */
698  if (!is_parallel_safe(root, (Node *) rte->functions))
699  return;
700  break;
701 
702  case RTE_TABLEFUNC:
703  /* not parallel safe */
704  return;
705 
706  case RTE_VALUES:
707  /* Check for parallel-restricted functions. */
708  if (!is_parallel_safe(root, (Node *) rte->values_lists))
709  return;
710  break;
711 
712  case RTE_CTE:
713 
714  /*
715  * CTE tuplestores aren't shared among parallel workers, so we
716  * force all CTE scans to happen in the leader. Also, populating
717  * the CTE would require executing a subplan that's not available
718  * in the worker, might be parallel-restricted, and must get
719  * executed only once.
720  */
721  return;
722 
723  case RTE_NAMEDTUPLESTORE:
724 
725  /*
726  * tuplestore cannot be shared, at least without more
727  * infrastructure to support that.
728  */
729  return;
730 
731  case RTE_RESULT:
732  /* RESULT RTEs, in themselves, are no problem. */
733  break;
734  case RTE_GROUP:
735  /* Shouldn't happen; we're only considering baserels here. */
736  Assert(false);
737  return;
738  }
739 
740  /*
741  * If there's anything in baserestrictinfo that's parallel-restricted, we
742  * give up on parallelizing access to this relation. We could consider
743  * instead postponing application of the restricted quals until we're
744  * above all the parallelism in the plan tree, but it's not clear that
745  * that would be a win in very many cases, and it might be tricky to make
746  * outer join clauses work correctly. It would likely break equivalence
747  * classes, too.
748  */
749  if (!is_parallel_safe(root, (Node *) rel->baserestrictinfo))
750  return;
751 
752  /*
753  * Likewise, if the relation's outputs are not parallel-safe, give up.
754  * (Usually, they're just Vars, but sometimes they're not.)
755  */
756  if (!is_parallel_safe(root, (Node *) rel->reltarget->exprs))
757  return;
758 
759  /* We have a winner. */
760  rel->consider_parallel = true;
761 }
762 
763 /*
764  * set_plain_rel_pathlist
765  * Build access paths for a plain relation (no subquery, no inheritance)
766  */
767 static void
768 set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
769 {
770  Relids required_outer;
771 
772  /*
773  * We don't support pushing join clauses into the quals of a seqscan, but
774  * it could still have required parameterization due to LATERAL refs in
775  * its tlist.
776  */
777  required_outer = rel->lateral_relids;
778 
779  /*
780  * Consider TID scans.
781  *
782  * If create_tidscan_paths returns true, then a TID scan path is forced.
783  * This happens when rel->baserestrictinfo contains CurrentOfExpr, because
784  * the executor can't handle any other type of path for such queries.
785  * Hence, we return without adding any other paths.
786  */
787  if (create_tidscan_paths(root, rel))
788  return;
789 
790  /* Consider sequential scan */
791  add_path(rel, create_seqscan_path(root, rel, required_outer, 0));
792 
793  /* If appropriate, consider parallel sequential scan */
794  if (rel->consider_parallel && required_outer == NULL)
795  create_plain_partial_paths(root, rel);
796 
797  /* Consider index scans */
798  create_index_paths(root, rel);
799 }
800 
801 /*
802  * create_plain_partial_paths
803  * Build partial access paths for parallel scan of a plain relation
804  */
805 static void
806 create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel)
807 {
808  int parallel_workers;
809 
810  parallel_workers = compute_parallel_worker(rel, rel->pages, -1,
811  max_parallel_workers_per_gather);
812 
813  /* If any limit was set to zero, the user doesn't want a parallel scan. */
814  if (parallel_workers <= 0)
815  return;
816 
817  /* Add an unordered partial path based on a parallel sequential scan. */
818  add_partial_path(rel, create_seqscan_path(root, rel, NULL, parallel_workers));
819 }
820 
821 /*
822  * set_tablesample_rel_size
823  * Set size estimates for a sampled relation
824  */
825 static void
826 set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
827 {
828  TableSampleClause *tsc = rte->tablesample;
829  TsmRoutine *tsm;
830  BlockNumber pages;
831  double tuples;
832 
833  /*
834  * Test any partial indexes of rel for applicability. We must do this
835  * first since partial unique indexes can affect size estimates.
836  */
837  check_index_predicates(root, rel);
838 
839  /*
840  * Call the sampling method's estimation function to estimate the number
841  * of pages it will read and the number of tuples it will return. (Note:
842  * we assume the function returns sane values.)
843  */
844  tsm = GetTsmRoutine(tsc->tsmhandler);
845  tsm->SampleScanGetSampleSize(root, rel, tsc->args,
846  &pages, &tuples);
847 
848  /*
849  * For the moment, because we will only consider a SampleScan path for the
850  * rel, it's okay to just overwrite the pages and tuples estimates for the
851  * whole relation. If we ever consider multiple path types for sampled
852  * rels, we'll need more complication.
853  */
854  rel->pages = pages;
855  rel->tuples = tuples;
856 
857  /* Mark rel with estimated output rows, width, etc */
858  set_baserel_size_estimates(root, rel);
859 }
860 
861 /*
862  * set_tablesample_rel_pathlist
863  * Build access paths for a sampled relation
864  */
865 static void
866 set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
867 {
868  Relids required_outer;
869  Path *path;
870 
871  /*
872  * We don't support pushing join clauses into the quals of a samplescan,
873  * but it could still have required parameterization due to LATERAL refs
874  * in its tlist or TABLESAMPLE arguments.
875  */
876  required_outer = rel->lateral_relids;
877 
878  /* Consider sampled scan */
879  path = create_samplescan_path(root, rel, required_outer);
880 
881  /*
882  * If the sampling method does not support repeatable scans, we must avoid
883  * plans that would scan the rel multiple times. Ideally, we'd simply
884  * avoid putting the rel on the inside of a nestloop join; but adding such
885  * a consideration to the planner seems like a great deal of complication
886  * to support an uncommon usage of second-rate sampling methods. Instead,
887  * if there is a risk that the query might perform an unsafe join, just
888  * wrap the SampleScan in a Materialize node. We can check for joins by
889  * counting the membership of all_query_rels (note that this correctly
890  * counts inheritance trees as single rels). If we're inside a subquery,
891  * we can't easily check whether a join might occur in the outer query, so
892  * just assume one is possible.
893  *
894  * GetTsmRoutine is relatively expensive compared to the other tests here,
895  * so check repeatable_across_scans last, even though that's a bit odd.
896  */
897  if ((root->query_level > 1 ||
898  bms_membership(root->all_query_rels) != BMS_SINGLETON) &&
899  !(GetTsmRoutine(rte->tablesample->tsmhandler)->repeatable_across_scans))
900  {
901  path = (Path *) create_material_path(rel, path);
902  }
903 
904  add_path(rel, path);
905 
906  /* For the moment, at least, there are no other paths to consider */
907 }
908 
909 /*
910  * set_foreign_size
911  * Set size estimates for a foreign table RTE
912  */
913 static void
914 set_foreign_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
915 {
916  /* Mark rel with estimated output rows, width, etc */
917  set_foreign_size_estimates(root, rel);
918 
919  /* Let FDW adjust the size estimates, if it can */
920  rel->fdwroutine->GetForeignRelSize(root, rel, rte->relid);
921 
922  /* ... but do not let it set the rows estimate to zero */
923  rel->rows = clamp_row_est(rel->rows);
924 
925  /*
926  * Also, make sure rel->tuples is not insane relative to rel->rows.
927  * Notably, this ensures sanity if pg_class.reltuples contains -1 and the
928  * FDW doesn't do anything to replace that.
929  */
930  rel->tuples = Max(rel->tuples, rel->rows);
931 }
932 
933 /*
934  * set_foreign_pathlist
935  * Build access paths for a foreign table RTE
936  */
937 static void
938 set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
939 {
940  /* Call the FDW's GetForeignPaths function to generate path(s) */
941  rel->fdwroutine->GetForeignPaths(root, rel, rte->relid);
942 }
943 
944 /*
945  * set_append_rel_size
946  * Set size estimates for a simple "append relation"
947  *
948  * The passed-in rel and RTE represent the entire append relation. The
949  * relation's contents are computed by appending together the output of the
950  * individual member relations. Note that in the non-partitioned inheritance
951  * case, the first member relation is actually the same table as is mentioned
952  * in the parent RTE ... but it has a different RTE and RelOptInfo. This is
953  * a good thing because their outputs are not the same size.
954  */
955 static void
956 set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
957  Index rti, RangeTblEntry *rte)
958 {
959  int parentRTindex = rti;
960  bool has_live_children;
961  double parent_rows;
962  double parent_size;
963  double *parent_attrsizes;
964  int nattrs;
965  ListCell *l;
966 
967  /* Guard against stack overflow due to overly deep inheritance tree. */
968  check_stack_depth();
969 
970  Assert(IS_SIMPLE_REL(rel));
971 
972  /*
973  * If this is a partitioned baserel, set the consider_partitionwise_join
974  * flag; currently, we only consider partitionwise joins with the baserel
975  * if its targetlist doesn't contain a whole-row Var.
976  */
977  if (enable_partitionwise_join &&
978  rel->reloptkind == RELOPT_BASEREL &&
979  rte->relkind == RELKIND_PARTITIONED_TABLE &&
980  bms_is_empty(rel->attr_needed[InvalidAttrNumber - rel->min_attr]))
981  rel->consider_partitionwise_join = true;
982 
983  /*
984  * Initialize to compute size estimates for whole append relation.
985  *
986  * We handle width estimates by weighting the widths of different child
987  * rels proportionally to their number of rows. This is sensible because
988  * the use of width estimates is mainly to compute the total relation
989  * "footprint" if we have to sort or hash it. To do this, we sum the
990  * total equivalent size (in "double" arithmetic) and then divide by the
991  * total rowcount estimate. This is done separately for the total rel
992  * width and each attribute.
993  *
994  * Note: if you consider changing this logic, beware that child rels could
995  * have zero rows and/or width, if they were excluded by constraints.
996  */
997  has_live_children = false;
998  parent_rows = 0;
999  parent_size = 0;
1000  nattrs = rel->max_attr - rel->min_attr + 1;
1001  parent_attrsizes = (double *) palloc0(nattrs * sizeof(double));
1002 
1003  foreach(l, root->append_rel_list)
1004  {
1005  AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
1006  int childRTindex;
1007  RangeTblEntry *childRTE;
1008  RelOptInfo *childrel;
1009  List *childrinfos;
1010  ListCell *parentvars;
1011  ListCell *childvars;
1012  ListCell *lc;
1013 
1014  /* append_rel_list contains all append rels; ignore others */
1015  if (appinfo->parent_relid != parentRTindex)
1016  continue;
1017 
1018  childRTindex = appinfo->child_relid;
1019  childRTE = root->simple_rte_array[childRTindex];
1020 
1021  /*
1022  * The child rel's RelOptInfo was already created during
1023  * add_other_rels_to_query.
1024  */
1025  childrel = find_base_rel(root, childRTindex);
1026  Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
1027 
1028  /* We may have already proven the child to be dummy. */
1029  if (IS_DUMMY_REL(childrel))
1030  continue;
1031 
1032  /*
1033  * We have to copy the parent's targetlist and quals to the child,
1034  * with appropriate substitution of variables. However, the
1035  * baserestrictinfo quals were already copied/substituted when the
1036  * child RelOptInfo was built. So we don't need any additional setup
1037  * before applying constraint exclusion.
1038  */
1039  if (relation_excluded_by_constraints(root, childrel, childRTE))
1040  {
1041  /*
1042  * This child need not be scanned, so we can omit it from the
1043  * appendrel.
1044  */
1045  set_dummy_rel_pathlist(childrel);
1046  continue;
1047  }
1048 
1049  /*
1050  * Constraint exclusion failed, so copy the parent's join quals and
1051  * targetlist to the child, with appropriate variable substitutions.
1052  *
1053  * We skip join quals that came from above outer joins that can null
1054  * this rel, since they would be of no value while generating paths
1055  * for the child. This saves some effort while processing the child
1056  * rel, and it also avoids an implementation restriction in
1057  * adjust_appendrel_attrs (it can't apply nullingrels to a non-Var).
1058  */
1059  childrinfos = NIL;
1060  foreach(lc, rel->joininfo)
1061  {
1062  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
1063 
1064  if (!bms_overlap(rinfo->clause_relids, rel->nulling_relids))
1065  childrinfos = lappend(childrinfos,
1066  adjust_appendrel_attrs(root,
1067  (Node *) rinfo,
1068  1, &appinfo));
1069  }
1070  childrel->joininfo = childrinfos;
1071 
1072  /*
1073  * Now for the child's targetlist.
1074  *
1075  * NB: the resulting childrel->reltarget->exprs may contain arbitrary
1076  * expressions, which otherwise would not occur in a rel's targetlist.
1077  * Code that might be looking at an appendrel child must cope with
1078  * such. (Normally, a rel's targetlist would only include Vars and
1079  * PlaceHolderVars.) XXX we do not bother to update the cost or width
1080  * fields of childrel->reltarget; not clear if that would be useful.
1081  */
1082  childrel->reltarget->exprs = (List *)
1083  adjust_appendrel_attrs(root,
1084  (Node *) rel->reltarget->exprs,
1085  1, &appinfo);
1086 
1087  /*
1088  * We have to make child entries in the EquivalenceClass data
1089  * structures as well. This is needed either if the parent
1090  * participates in some eclass joins (because we will want to consider
1091  * inner-indexscan joins on the individual children) or if the parent
1092  * has useful pathkeys (because we should try to build MergeAppend
1093  * paths that produce those sort orderings).
1094  */
1095  if (rel->has_eclass_joins || has_useful_pathkeys(root, rel))
1096  add_child_rel_equivalences(root, appinfo, rel, childrel);
1097  childrel->has_eclass_joins = rel->has_eclass_joins;
1098 
1099  /*
1100  * Note: we could compute appropriate attr_needed data for the child's
1101  * variables, by transforming the parent's attr_needed through the
1102  * translated_vars mapping. However, currently there's no need
1103  * because attr_needed is only examined for base relations not
1104  * otherrels. So we just leave the child's attr_needed empty.
1105  */
1106 
1107  /*
1108  * If we consider partitionwise joins with the parent rel, do the same
1109  * for partitioned child rels.
1110  *
1111  * Note: here we abuse the consider_partitionwise_join flag by setting
1112  * it for child rels that are not themselves partitioned. We do so to
1113  * tell try_partitionwise_join() that the child rel is sufficiently
1114  * valid to be used as a per-partition input, even if it later gets
1115  * proven to be dummy. (It's not usable until we've set up the
1116  * reltarget and EC entries, which we just did.)
1117  */
1118  if (rel->consider_partitionwise_join)
1119  childrel->consider_partitionwise_join = true;
1120 
1121  /*
1122  * If parallelism is allowable for this query in general, see whether
1123  * it's allowable for this childrel in particular. But if we've
1124  * already decided the appendrel is not parallel-safe as a whole,
1125  * there's no point in considering parallelism for this child. For
1126  * consistency, do this before calling set_rel_size() for the child.
1127  */
1128  if (root->glob->parallelModeOK && rel->consider_parallel)
1129  set_rel_consider_parallel(root, childrel, childRTE);
1130 
1131  /*
1132  * Compute the child's size.
1133  */
1134  set_rel_size(root, childrel, childRTindex, childRTE);
1135 
1136  /*
1137  * It is possible that constraint exclusion detected a contradiction
1138  * within a child subquery, even though we didn't prove one above. If
1139  * so, we can skip this child.
1140  */
1141  if (IS_DUMMY_REL(childrel))
1142  continue;
1143 
1144  /* We have at least one live child. */
1145  has_live_children = true;
1146 
1147  /*
1148  * If any live child is not parallel-safe, treat the whole appendrel
1149  * as not parallel-safe. In future we might be able to generate plans
1150  * in which some children are farmed out to workers while others are
1151  * not; but we don't have that today, so it's a waste to consider
1152  * partial paths anywhere in the appendrel unless it's all safe.
1153  * (Child rels visited before this one will be unmarked in
1154  * set_append_rel_pathlist().)
1155  */
1156  if (!childrel->consider_parallel)
1157  rel->consider_parallel = false;
1158 
1159  /*
1160  * Accumulate size information from each live child.
1161  */
1162  Assert(childrel->rows > 0);
1163 
1164  parent_rows += childrel->rows;
1165  parent_size += childrel->reltarget->width * childrel->rows;
1166 
1167  /*
1168  * Accumulate per-column estimates too. We need not do anything for
1169  * PlaceHolderVars in the parent list. If child expression isn't a
1170  * Var, or we didn't record a width estimate for it, we have to fall
1171  * back on a datatype-based estimate.
1172  *
1173  * By construction, child's targetlist is 1-to-1 with parent's.
1174  */
1175  forboth(parentvars, rel->reltarget->exprs,
1176  childvars, childrel->reltarget->exprs)
1177  {
1178  Var *parentvar = (Var *) lfirst(parentvars);
1179  Node *childvar = (Node *) lfirst(childvars);
1180 
1181  if (IsA(parentvar, Var) && parentvar->varno == parentRTindex)
1182  {
1183  int pndx = parentvar->varattno - rel->min_attr;
1184  int32 child_width = 0;
1185 
1186  if (IsA(childvar, Var) &&
1187  ((Var *) childvar)->varno == childrel->relid)
1188  {
1189  int cndx = ((Var *) childvar)->varattno - childrel->min_attr;
1190 
1191  child_width = childrel->attr_widths[cndx];
1192  }
1193  if (child_width <= 0)
1194  child_width = get_typavgwidth(exprType(childvar),
1195  exprTypmod(childvar));
1196  Assert(child_width > 0);
1197  parent_attrsizes[pndx] += child_width * childrel->rows;
1198  }
1199  }
1200  }
1201 
1202  if (has_live_children)
1203  {
1204  /*
1205  * Save the finished size estimates.
1206  */
1207  int i;
1208 
1209  Assert(parent_rows > 0);
1210  rel->rows = parent_rows;
1211  rel->reltarget->width = rint(parent_size / parent_rows);
1212  for (i = 0; i < nattrs; i++)
1213  rel->attr_widths[i] = rint(parent_attrsizes[i] / parent_rows);
1214 
1215  /*
1216  * Set "raw tuples" count equal to "rows" for the appendrel; needed
1217  * because some places assume rel->tuples is valid for any baserel.
1218  */
1219  rel->tuples = parent_rows;
1220 
1221  /*
1222  * Note that we leave rel->pages as zero; this is important to avoid
1223  * double-counting the appendrel tree in total_table_pages.
1224  */
1225  }
1226  else
1227  {
1228  /*
1229  * All children were excluded by constraints, so mark the whole
1230  * appendrel dummy. We must do this in this phase so that the rel's
1231  * dummy-ness is visible when we generate paths for other rels.
1232  */
1233  set_dummy_rel_pathlist(rel);
1234  }
1235 
1236  pfree(parent_attrsizes);
1237 }
1238 
1239 /*
1240  * set_append_rel_pathlist
1241  * Build access paths for an "append relation"
1242  */
1243 static void
1244 set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
1245  Index rti, RangeTblEntry *rte)
1246 {
1247  int parentRTindex = rti;
1248  List *live_childrels = NIL;
1249  ListCell *l;
1250 
1251  /*
1252  * Generate access paths for each member relation, and remember the
1253  * non-dummy children.
1254  */
1255  foreach(l, root->append_rel_list)
1256  {
1257  AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
1258  int childRTindex;
1259  RangeTblEntry *childRTE;
1260  RelOptInfo *childrel;
1261 
1262  /* append_rel_list contains all append rels; ignore others */
1263  if (appinfo->parent_relid != parentRTindex)
1264  continue;
1265 
1266  /* Re-locate the child RTE and RelOptInfo */
1267  childRTindex = appinfo->child_relid;
1268  childRTE = root->simple_rte_array[childRTindex];
1269  childrel = root->simple_rel_array[childRTindex];
1270 
1271  /*
1272  * If set_append_rel_size() decided the parent appendrel was
1273  * parallel-unsafe at some point after visiting this child rel, we
1274  * need to propagate the unsafety marking down to the child, so that
1275  * we don't generate useless partial paths for it.
1276  */
1277  if (!rel->consider_parallel)
1278  childrel->consider_parallel = false;
1279 
1280  /*
1281  * Compute the child's access paths.
1282  */
1283  set_rel_pathlist(root, childrel, childRTindex, childRTE);
1284 
1285  /*
1286  * If child is dummy, ignore it.
1287  */
1288  if (IS_DUMMY_REL(childrel))
1289  continue;
1290 
1291  /*
1292  * Child is live, so add it to the live_childrels list for use below.
1293  */
1294  live_childrels = lappend(live_childrels, childrel);
1295  }
1296 
1297  /* Add paths to the append relation. */
1298  add_paths_to_append_rel(root, rel, live_childrels);
1299 }
1300 
1301 
1302 /*
1303  * add_paths_to_append_rel
1304  * Generate paths for the given append relation given the set of non-dummy
1305  * child rels.
1306  *
1307  * The function collects all parameterizations and orderings supported by the
1308  * non-dummy children. For every such parameterization or ordering, it creates
1309  * an append path collecting one path from each non-dummy child with given
1310  * parameterization or ordering. Similarly it collects partial paths from
1311  * non-dummy children to create partial append paths.
1312  */
1313 void
1314 add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
1315  List *live_childrels)
1316 {
1317  List *subpaths = NIL;
1318  bool subpaths_valid = true;
1319  List *startup_subpaths = NIL;
1320  bool startup_subpaths_valid = true;
1321  List *partial_subpaths = NIL;
1322  List *pa_partial_subpaths = NIL;
1323  List *pa_nonpartial_subpaths = NIL;
1324  bool partial_subpaths_valid = true;
1325  bool pa_subpaths_valid;
1326  List *all_child_pathkeys = NIL;
1327  List *all_child_outers = NIL;
1328  ListCell *l;
1329  double partial_rows = -1;
1330 
1331  /* If appropriate, consider parallel append */
1332  pa_subpaths_valid = enable_parallel_append && rel->consider_parallel;
1333 
1334  /*
1335  * For every non-dummy child, remember the cheapest path. Also, identify
1336  * all pathkeys (orderings) and parameterizations (required_outer sets)
1337  * available for the non-dummy member relations.
1338  */
1339  foreach(l, live_childrels)
1340  {
1341  RelOptInfo *childrel = lfirst(l);
1342  ListCell *lcp;
1343  Path *cheapest_partial_path = NULL;
1344 
1345  /*
1346  * If child has an unparameterized cheapest-total path, add that to
1347  * the unparameterized Append path we are constructing for the parent.
1348  * If not, there's no workable unparameterized path.
1349  *
1350  * With partitionwise aggregates, the child rel's pathlist may be
1351  * empty, so don't assume that a path exists here.
1352  */
1353  if (childrel->pathlist != NIL &&
1354  childrel->cheapest_total_path->param_info == NULL)
1355  accumulate_append_subpath(childrel->cheapest_total_path,
1356  &subpaths, NULL);
1357  else
1358  subpaths_valid = false;
1359 
1360  /*
1361  * When the planner is considering cheap startup plans, we'll also
1362  * collect all the cheapest_startup_paths (if set) and build an
1363  * AppendPath containing those as subpaths.
1364  */
1365  if (rel->consider_startup && childrel->cheapest_startup_path != NULL)
1366  {
1367  /* cheapest_startup_path must not be a parameterized path. */
1368  Assert(childrel->cheapest_startup_path->param_info == NULL);
1369  accumulate_append_subpath(childrel->cheapest_startup_path,
1370  &startup_subpaths,
1371  NULL);
1372  }
1373  else
1374  startup_subpaths_valid = false;
1375 
1376 
1377  /* Same idea, but for a partial plan. */
1378  if (childrel->partial_pathlist != NIL)
1379  {
1380  cheapest_partial_path = linitial(childrel->partial_pathlist);
1381  accumulate_append_subpath(cheapest_partial_path,
1382  &partial_subpaths, NULL);
1383  }
1384  else
1385  partial_subpaths_valid = false;
1386 
1387  /*
1388  * Same idea, but for a parallel append mixing partial and non-partial
1389  * paths.
1390  */
1391  if (pa_subpaths_valid)
1392  {
1393  Path *nppath = NULL;
1394 
1395  nppath =
1396  get_cheapest_parallel_safe_total_inner(childrel->pathlist);
1397 
1398  if (cheapest_partial_path == NULL && nppath == NULL)
1399  {
1400  /* Neither a partial nor a parallel-safe path? Forget it. */
1401  pa_subpaths_valid = false;
1402  }
1403  else if (nppath == NULL ||
1404  (cheapest_partial_path != NULL &&
1405  cheapest_partial_path->total_cost < nppath->total_cost))
1406  {
1407  /* Partial path is cheaper or the only option. */
1408  Assert(cheapest_partial_path != NULL);
1409  accumulate_append_subpath(cheapest_partial_path,
1410  &pa_partial_subpaths,
1411  &pa_nonpartial_subpaths);
1412  }
1413  else
1414  {
1415  /*
1416  * Either we've got only a non-partial path, or we think that
1417  * a single backend can execute the best non-partial path
1418  * faster than all the parallel backends working together can
1419  * execute the best partial path.
1420  *
1421  * It might make sense to be more aggressive here. Even if
1422  * the best non-partial path is more expensive than the best
1423  * partial path, it could still be better to choose the
1424  * non-partial path if there are several such paths that can
1425  * be given to different workers. For now, we don't try to
1426  * figure that out.
1427  */
1428  accumulate_append_subpath(nppath,
1429  &pa_nonpartial_subpaths,
1430  NULL);
1431  }
1432  }
1433 
1434  /*
1435  * Collect lists of all the available path orderings and
1436  * parameterizations for all the children. We use these as a
1437  * heuristic to indicate which sort orderings and parameterizations we
1438  * should build Append and MergeAppend paths for.
1439  */
1440  foreach(lcp, childrel->pathlist)
1441  {
1442  Path *childpath = (Path *) lfirst(lcp);
1443  List *childkeys = childpath->pathkeys;
1444  Relids childouter = PATH_REQ_OUTER(childpath);
1445 
1446  /* Unsorted paths don't contribute to pathkey list */
1447  if (childkeys != NIL)
1448  {
1449  ListCell *lpk;
1450  bool found = false;
1451 
1452  /* Have we already seen this ordering? */
1453  foreach(lpk, all_child_pathkeys)
1454  {
1455  List *existing_pathkeys = (List *) lfirst(lpk);
1456 
1457  if (compare_pathkeys(existing_pathkeys,
1458  childkeys) == PATHKEYS_EQUAL)
1459  {
1460  found = true;
1461  break;
1462  }
1463  }
1464  if (!found)
1465  {
1466  /* No, so add it to all_child_pathkeys */
1467  all_child_pathkeys = lappend(all_child_pathkeys,
1468  childkeys);
1469  }
1470  }
1471 
1472  /* Unparameterized paths don't contribute to param-set list */
1473  if (childouter)
1474  {
1475  ListCell *lco;
1476  bool found = false;
1477 
1478  /* Have we already seen this param set? */
1479  foreach(lco, all_child_outers)
1480  {
1481  Relids existing_outers = (Relids) lfirst(lco);
1482 
1483  if (bms_equal(existing_outers, childouter))
1484  {
1485  found = true;
1486  break;
1487  }
1488  }
1489  if (!found)
1490  {
1491  /* No, so add it to all_child_outers */
1492  all_child_outers = lappend(all_child_outers,
1493  childouter);
1494  }
1495  }
1496  }
1497  }
1498 
1499  /*
1500  * If we found unparameterized paths for all children, build an unordered,
1501  * unparameterized Append path for the rel. (Note: this is correct even
1502  * if we have zero or one live subpath due to constraint exclusion.)
1503  */
1504  if (subpaths_valid)
1505  add_path(rel, (Path *) create_append_path(root, rel, subpaths, NIL,
1506  NIL, NULL, 0, false,
1507  -1));
1508 
1509  /* build an AppendPath for the cheap startup paths, if valid */
1510  if (startup_subpaths_valid)
1511  add_path(rel, (Path *) create_append_path(root, rel, startup_subpaths,
1512  NIL, NIL, NULL, 0, false, -1));
1513 
1514  /*
1515  * Consider an append of unordered, unparameterized partial paths. Make
1516  * it parallel-aware if possible.
1517  */
1518  if (partial_subpaths_valid && partial_subpaths != NIL)
1519  {
1520  AppendPath *appendpath;
1521  ListCell *lc;
1522  int parallel_workers = 0;
1523 
1524  /* Find the highest number of workers requested for any subpath. */
1525  foreach(lc, partial_subpaths)
1526  {
1527  Path *path = lfirst(lc);
1528 
1529  parallel_workers = Max(parallel_workers, path->parallel_workers);
1530  }
1531  Assert(parallel_workers > 0);
1532 
1533  /*
1534  * If the use of parallel append is permitted, always request at least
1535  * log2(# of children) workers. We assume it can be useful to have
1536  * extra workers in this case because they will be spread out across
1537  * the children. The precise formula is just a guess, but we don't
1538  * want to end up with a radically different answer for a table with N
1539  * partitions vs. an unpartitioned table with the same data, so the
1540  * use of some kind of log-scaling here seems to make some sense.
1541  */
1542  if (enable_parallel_append)
1543  {
1544  parallel_workers = Max(parallel_workers,
1545  pg_leftmost_one_pos32(list_length(live_childrels)) + 1);
1546  parallel_workers = Min(parallel_workers,
1547  max_parallel_workers_per_gather);
1548  }
1549  Assert(parallel_workers > 0);
1550 
1551  /* Generate a partial append path. */
1552  appendpath = create_append_path(root, rel, NIL, partial_subpaths,
1553  NIL, NULL, parallel_workers,
1554  enable_parallel_append,
1555  -1);
1556 
1557  /*
1558  * Make sure any subsequent partial paths use the same row count
1559  * estimate.
1560  */
1561  partial_rows = appendpath->path.rows;
1562 
1563  /* Add the path. */
1564  add_partial_path(rel, (Path *) appendpath);
1565  }
1566 
1567  /*
1568  * Consider a parallel-aware append using a mix of partial and non-partial
1569  * paths. (This only makes sense if there's at least one child which has
1570  * a non-partial path that is substantially cheaper than any partial path;
1571  * otherwise, we should use the append path added in the previous step.)
1572  */
1573  if (pa_subpaths_valid && pa_nonpartial_subpaths != NIL)
1574  {
1575  AppendPath *appendpath;
1576  ListCell *lc;
1577  int parallel_workers = 0;
1578 
1579  /*
1580  * Find the highest number of workers requested for any partial
1581  * subpath.
1582  */
1583  foreach(lc, pa_partial_subpaths)
1584  {
1585  Path *path = lfirst(lc);
1586 
1587  parallel_workers = Max(parallel_workers, path->parallel_workers);
1588  }
1589 
1590  /*
1591  * Same formula here as above. It's even more important in this
1592  * instance because the non-partial paths won't contribute anything to
1593  * the planned number of parallel workers.
1594  */
1595  parallel_workers = Max(parallel_workers,
1596  pg_leftmost_one_pos32(list_length(live_childrels)) + 1);
1597  parallel_workers = Min(parallel_workers,
1598  max_parallel_workers_per_gather);
1599  Assert(parallel_workers > 0);
1600 
1601  appendpath = create_append_path(root, rel, pa_nonpartial_subpaths,
1602  pa_partial_subpaths,
1603  NIL, NULL, parallel_workers, true,
1604  partial_rows);
1605  add_partial_path(rel, (Path *) appendpath);
1606  }
1607 
1608  /*
1609  * Also build unparameterized ordered append paths based on the collected
1610  * list of child pathkeys.
1611  */
1612  if (subpaths_valid)
1613  generate_orderedappend_paths(root, rel, live_childrels,
1614  all_child_pathkeys);
1615 
1616  /*
1617  * Build Append paths for each parameterization seen among the child rels.
1618  * (This may look pretty expensive, but in most cases of practical
1619  * interest, the child rels will expose mostly the same parameterizations,
1620  * so that not that many cases actually get considered here.)
1621  *
1622  * The Append node itself cannot enforce quals, so all qual checking must
1623  * be done in the child paths. This means that to have a parameterized
1624  * Append path, we must have the exact same parameterization for each
1625  * child path; otherwise some children might be failing to check the
1626  * moved-down quals. To make them match up, we can try to increase the
1627  * parameterization of lesser-parameterized paths.
1628  */
1629  foreach(l, all_child_outers)
1630  {
1631  Relids required_outer = (Relids) lfirst(l);
1632  ListCell *lcr;
1633 
1634  /* Select the child paths for an Append with this parameterization */
1635  subpaths = NIL;
1636  subpaths_valid = true;
1637  foreach(lcr, live_childrels)
1638  {
1639  RelOptInfo *childrel = (RelOptInfo *) lfirst(lcr);
1640  Path *subpath;
1641 
1642  if (childrel->pathlist == NIL)
1643  {
1644  /* failed to make a suitable path for this child */
1645  subpaths_valid = false;
1646  break;
1647  }
1648 
1649  subpath = get_cheapest_parameterized_child_path(root,
1650  childrel,
1651  required_outer);
1652  if (subpath == NULL)
1653  {
1654  /* failed to make a suitable path for this child */
1655  subpaths_valid = false;
1656  break;
1657  }
1658  accumulate_append_subpath(subpath, &subpaths, NULL);
1659  }
1660 
1661  if (subpaths_valid)
1662  add_path(rel, (Path *)
1663  create_append_path(root, rel, subpaths, NIL,
1664  NIL, required_outer, 0, false,
1665  -1));
1666  }
1667 
1668  /*
1669  * When there is only a single child relation, the Append path can inherit
1670  * any ordering available for the child rel's path, so that it's useful to
1671  * consider ordered partial paths. Above we only considered the cheapest
1672  * partial path for each child, but let's also make paths using any
1673  * partial paths that have pathkeys.
1674  */
1675  if (list_length(live_childrels) == 1)
1676  {
1677  RelOptInfo *childrel = (RelOptInfo *) linitial(live_childrels);
1678 
1679  /* skip the cheapest partial path, since we already used that above */
1680  for_each_from(l, childrel->partial_pathlist, 1)
1681  {
1682  Path *path = (Path *) lfirst(l);
1683  AppendPath *appendpath;
1684 
1685  /* skip paths with no pathkeys. */
1686  if (path->pathkeys == NIL)
1687  continue;
1688 
1689  appendpath = create_append_path(root, rel, NIL, list_make1(path),
1690  NIL, NULL,
1691  path->parallel_workers, true,
1692  partial_rows);
1693  add_partial_path(rel, (Path *) appendpath);
1694  }
1695  }
1696 }
1697 
1698 /*
1699  * generate_orderedappend_paths
1700  * Generate ordered append paths for an append relation
1701  *
1702  * Usually we generate MergeAppend paths here, but there are some special
1703  * cases where we can generate simple Append paths, because the subpaths
1704  * can provide tuples in the required order already.
1705  *
1706  * We generate a path for each ordering (pathkey list) appearing in
1707  * all_child_pathkeys.
1708  *
1709  * We consider both cheapest-startup and cheapest-total cases, ie, for each
1710  * interesting ordering, collect all the cheapest startup subpaths and all the
1711  * cheapest total paths, and build a suitable path for each case.
1712  *
1713  * We don't currently generate any parameterized ordered paths here. While
1714  * it would not take much more code here to do so, it's very unclear that it
1715  * is worth the planning cycles to investigate such paths: there's little
1716  * use for an ordered path on the inside of a nestloop. In fact, it's likely
1717  * that the current coding of add_path would reject such paths out of hand,
1718  * because add_path gives no credit for sort ordering of parameterized paths,
1719  * and a parameterized MergeAppend is going to be more expensive than the
1720  * corresponding parameterized Append path. If we ever try harder to support
1721  * parameterized mergejoin plans, it might be worth adding support for
1722  * parameterized paths here to feed such joins. (See notes in
1723  * optimizer/README for why that might not ever happen, though.)
1724  */
1725 static void
1726 generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel,
1727  List *live_childrels,
1728  List *all_child_pathkeys)
1729 {
1730  ListCell *lcp;
1731  List *partition_pathkeys = NIL;
1732  List *partition_pathkeys_desc = NIL;
1733  bool partition_pathkeys_partial = true;
1734  bool partition_pathkeys_desc_partial = true;
1735 
1736  /*
1737  * Some partitioned table setups may allow us to use an Append node
1738  * instead of a MergeAppend. This is possible in cases such as RANGE
1739  * partitioned tables where it's guaranteed that an earlier partition must
1740  * contain rows which come earlier in the sort order. To detect whether
1741  * this is relevant, build pathkey descriptions of the partition ordering,
1742  * for both forward and reverse scans.
1743  */
1744  if (rel->part_scheme != NULL && IS_SIMPLE_REL(rel) &&
1745  partitions_are_ordered(rel->boundinfo, rel->live_parts))
1746  {
1747  partition_pathkeys = build_partition_pathkeys(root, rel,
1748  ForwardScanDirection,
1749  &partition_pathkeys_partial);
1750 
1751  partition_pathkeys_desc = build_partition_pathkeys(root, rel,
1752  BackwardScanDirection,
1753  &partition_pathkeys_desc_partial);
1754 
1755  /*
1756  * You might think we should truncate_useless_pathkeys here, but
1757  * allowing partition keys which are a subset of the query's pathkeys
1758  * can often be useful. For example, consider a table partitioned by
1759  * RANGE (a, b), and a query with ORDER BY a, b, c. If we have child
1760  * paths that can produce the a, b, c ordering (perhaps via indexes on
1761  * (a, b, c)) then it works to consider the appendrel output as
1762  * ordered by a, b, c.
1763  */
1764  }
1765 
1766  /* Now consider each interesting sort ordering */
1767  foreach(lcp, all_child_pathkeys)
1768  {
1769  List *pathkeys = (List *) lfirst(lcp);
1770  List *startup_subpaths = NIL;
1771  List *total_subpaths = NIL;
1772  List *fractional_subpaths = NIL;
1773  bool startup_neq_total = false;
1774  bool match_partition_order;
1775  bool match_partition_order_desc;
1776  int end_index;
1777  int first_index;
1778  int direction;
1779 
1780  /*
1781  * Determine if this sort ordering matches any partition pathkeys we
1782  * have, for both ascending and descending partition order. If the
1783  * partition pathkeys happen to be contained in pathkeys then it still
1784  * works, as described above, providing that the partition pathkeys
1785  * are complete and not just a prefix of the partition keys. (In such
1786  * cases we'll be relying on the child paths to have sorted the
1787  * lower-order columns of the required pathkeys.)
1788  */
1789  match_partition_order =
1790  pathkeys_contained_in(pathkeys, partition_pathkeys) ||
1791  (!partition_pathkeys_partial &&
1792  pathkeys_contained_in(partition_pathkeys, pathkeys));
1793 
1794  match_partition_order_desc = !match_partition_order &&
1795  (pathkeys_contained_in(pathkeys, partition_pathkeys_desc) ||
1796  (!partition_pathkeys_desc_partial &&
1797  pathkeys_contained_in(partition_pathkeys_desc, pathkeys)));
1798 
1799  /*
1800  * When the required pathkeys match the reverse of the partition
1801  * order, we must build the list of paths in reverse starting with the
1802  * last matching partition first. We can get away without making any
1803  * special cases for this in the loop below by just looping backward
1804  * over the child relations in this case.
1805  */
1806  if (match_partition_order_desc)
1807  {
1808  /* loop backward */
1809  first_index = list_length(live_childrels) - 1;
1810  end_index = -1;
1811  direction = -1;
1812 
1813  /*
1814  * Set this to true to save us having to check for
1815  * match_partition_order_desc in the loop below.
1816  */
1817  match_partition_order = true;
1818  }
1819  else
1820  {
1821  /* for all other case, loop forward */
1822  first_index = 0;
1823  end_index = list_length(live_childrels);
1824  direction = 1;
1825  }
1826 
1827  /* Select the child paths for this ordering... */
1828  for (int i = first_index; i != end_index; i += direction)
1829  {
1830  RelOptInfo *childrel = list_nth_node(RelOptInfo, live_childrels, i);
1831  Path *cheapest_startup,
1832  *cheapest_total,
1833  *cheapest_fractional = NULL;
1834 
1835  /* Locate the right paths, if they are available. */
1836  cheapest_startup =
1837  get_cheapest_path_for_pathkeys(childrel->pathlist,
1838  pathkeys,
1839  NULL,
1840  STARTUP_COST,
1841  false);
1842  cheapest_total =
1843  get_cheapest_path_for_pathkeys(childrel->pathlist,
1844  pathkeys,
1845  NULL,
1846  TOTAL_COST,
1847  false);
1848 
1849  /*
1850  * If we can't find any paths with the right order just use the
1851  * cheapest-total path; we'll have to sort it later.
1852  */
1853  if (cheapest_startup == NULL || cheapest_total == NULL)
1854  {
1855  cheapest_startup = cheapest_total =
1856  childrel->cheapest_total_path;
1857  /* Assert we do have an unparameterized path for this child */
1858  Assert(cheapest_total->param_info == NULL);
1859  }
1860 
1861  /*
1862  * When building a fractional path, determine a cheapest
1863  * fractional path for each child relation too. Looking at startup
1864  * and total costs is not enough, because the cheapest fractional
1865  * path may be dominated by two separate paths (one for startup,
1866  * one for total).
1867  *
1868  * When needed (building fractional path), determine the cheapest
1869  * fractional path too.
1870  */
1871  if (root->tuple_fraction > 0)
1872  {
1873  double path_fraction = (1.0 / root->tuple_fraction);
1874 
1875  cheapest_fractional =
1876  get_cheapest_fractional_path_for_pathkeys(childrel->pathlist,
1877  pathkeys,
1878  NULL,
1879  path_fraction);
1880 
1881  /*
1882  * If we found no path with matching pathkeys, use the
1883  * cheapest total path instead.
1884  *
1885  * XXX We might consider partially sorted paths too (with an
1886  * incremental sort on top). But we'd have to build all the
1887  * incremental paths, do the costing etc.
1888  */
1889  if (!cheapest_fractional)
1890  cheapest_fractional = cheapest_total;
1891  }
1892 
1893  /*
1894  * Notice whether we actually have different paths for the
1895  * "cheapest" and "total" cases; frequently there will be no point
1896  * in two create_merge_append_path() calls.
1897  */
1898  if (cheapest_startup != cheapest_total)
1899  startup_neq_total = true;
1900 
1901  /*
1902  * Collect the appropriate child paths. The required logic varies
1903  * for the Append and MergeAppend cases.
1904  */
1905  if (match_partition_order)
1906  {
1907  /*
1908  * We're going to make a plain Append path. We don't need
1909  * most of what accumulate_append_subpath would do, but we do
1910  * want to cut out child Appends or MergeAppends if they have
1911  * just a single subpath (and hence aren't doing anything
1912  * useful).
1913  */
1914  cheapest_startup = get_singleton_append_subpath(cheapest_startup);
1915  cheapest_total = get_singleton_append_subpath(cheapest_total);
1916 
1917  startup_subpaths = lappend(startup_subpaths, cheapest_startup);
1918  total_subpaths = lappend(total_subpaths, cheapest_total);
1919 
1920  if (cheapest_fractional)
1921  {
1922  cheapest_fractional = get_singleton_append_subpath(cheapest_fractional);
1923  fractional_subpaths = lappend(fractional_subpaths, cheapest_fractional);
1924  }
1925  }
1926  else
1927  {
1928  /*
1929  * Otherwise, rely on accumulate_append_subpath to collect the
1930  * child paths for the MergeAppend.
1931  */
1932  accumulate_append_subpath(cheapest_startup,
1933  &startup_subpaths, NULL);
1934  accumulate_append_subpath(cheapest_total,
1935  &total_subpaths, NULL);
1936 
1937  if (cheapest_fractional)
1938  accumulate_append_subpath(cheapest_fractional,
1939  &fractional_subpaths, NULL);
1940  }
1941  }
1942 
1943  /* ... and build the Append or MergeAppend paths */
1944  if (match_partition_order)
1945  {
1946  /* We only need Append */
1947  add_path(rel, (Path *) create_append_path(root,
1948  rel,
1949  startup_subpaths,
1950  NIL,
1951  pathkeys,
1952  NULL,
1953  0,
1954  false,
1955  -1));
1956  if (startup_neq_total)
1957  add_path(rel, (Path *) create_append_path(root,
1958  rel,
1959  total_subpaths,
1960  NIL,
1961  pathkeys,
1962  NULL,
1963  0,
1964  false,
1965  -1));
1966 
1967  if (fractional_subpaths)
1968  add_path(rel, (Path *) create_append_path(root,
1969  rel,
1970  fractional_subpaths,
1971  NIL,
1972  pathkeys,
1973  NULL,
1974  0,
1975  false,
1976  -1));
1977  }
1978  else
1979  {
1980  /* We need MergeAppend */
1981  add_path(rel, (Path *) create_merge_append_path(root,
1982  rel,
1983  startup_subpaths,
1984  pathkeys,
1985  NULL));
1986  if (startup_neq_total)
1987  add_path(rel, (Path *) create_merge_append_path(root,
1988  rel,
1989  total_subpaths,
1990  pathkeys,
1991  NULL));
1992 
1993  if (fractional_subpaths)
1994  add_path(rel, (Path *) create_merge_append_path(root,
1995  rel,
1996  fractional_subpaths,
1997  pathkeys,
1998  NULL));
1999  }
2000  }
2001 }
2002 
2003 /*
2004  * get_cheapest_parameterized_child_path
2005  * Get cheapest path for this relation that has exactly the requested
2006  * parameterization.
2007  *
2008  * Returns NULL if unable to create such a path.
2009  */
2010 static Path *
2011 get_cheapest_parameterized_child_path(PlannerInfo *root, RelOptInfo *rel,
2012  Relids required_outer)
2013 {
2014  Path *cheapest;
2015  ListCell *lc;
2016 
2017  /*
2018  * Look up the cheapest existing path with no more than the needed
2019  * parameterization. If it has exactly the needed parameterization, we're
2020  * done.
2021  */
2022  cheapest = get_cheapest_path_for_pathkeys(rel->pathlist,
2023  NIL,
2024  required_outer,
2025  TOTAL_COST,
2026  false);
2027  Assert(cheapest != NULL);
2028  if (bms_equal(PATH_REQ_OUTER(cheapest), required_outer))
2029  return cheapest;
2030 
2031  /*
2032  * Otherwise, we can "reparameterize" an existing path to match the given
2033  * parameterization, which effectively means pushing down additional
2034  * joinquals to be checked within the path's scan. However, some existing
2035  * paths might check the available joinquals already while others don't;
2036  * therefore, it's not clear which existing path will be cheapest after
2037  * reparameterization. We have to go through them all and find out.
2038  */
2039  cheapest = NULL;
2040  foreach(lc, rel->pathlist)
2041  {
2042  Path *path = (Path *) lfirst(lc);
2043 
2044  /* Can't use it if it needs more than requested parameterization */
2045  if (!bms_is_subset(PATH_REQ_OUTER(path), required_outer))
2046  continue;
2047 
2048  /*
2049  * Reparameterization can only increase the path's cost, so if it's
2050  * already more expensive than the current cheapest, forget it.
2051  */
2052  if (cheapest != NULL &&
2053  compare_path_costs(cheapest, path, TOTAL_COST) <= 0)
2054  continue;
2055 
2056  /* Reparameterize if needed, then recheck cost */
2057  if (!bms_equal(PATH_REQ_OUTER(path), required_outer))
2058  {
2059  path = reparameterize_path(root, path, required_outer, 1.0);
2060  if (path == NULL)
2061  continue; /* failed to reparameterize this one */
2062  Assert(bms_equal(PATH_REQ_OUTER(path), required_outer));
2063 
2064  if (cheapest != NULL &&
2065  compare_path_costs(cheapest, path, TOTAL_COST) <= 0)
2066  continue;
2067  }
2068 
2069  /* We have a new best path */
2070  cheapest = path;
2071  }
2072 
2073  /* Return the best path, or NULL if we found no suitable candidate */
2074  return cheapest;
2075 }
2076 
2077 /*
2078  * accumulate_append_subpath
2079  * Add a subpath to the list being built for an Append or MergeAppend.
2080  *
2081  * It's possible that the child is itself an Append or MergeAppend path, in
2082  * which case we can "cut out the middleman" and just add its child paths to
2083  * our own list. (We don't try to do this earlier because we need to apply
2084  * both levels of transformation to the quals.)
2085  *
2086  * Note that if we omit a child MergeAppend in this way, we are effectively
2087  * omitting a sort step, which seems fine: if the parent is to be an Append,
2088  * its result would be unsorted anyway, while if the parent is to be a
2089  * MergeAppend, there's no point in a separate sort on a child.
2090  *
2091  * Normally, either path is a partial path and subpaths is a list of partial
2092  * paths, or else path is a non-partial plan and subpaths is a list of those.
2093  * However, if path is a parallel-aware Append, then we add its partial path
2094  * children to subpaths and the rest to special_subpaths. If the latter is
2095  * NULL, we don't flatten the path at all (unless it contains only partial
2096  * paths).
2097  */
2098 static void
2099 accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths)
2100 {
2101  if (IsA(path, AppendPath))
2102  {
2103  AppendPath *apath = (AppendPath *) path;
2104 
2105  if (!apath->path.parallel_aware || apath->first_partial_path == 0)
2106  {
2107  *subpaths = list_concat(*subpaths, apath->subpaths);
2108  return;
2109  }
2110  else if (special_subpaths != NULL)
2111  {
2112  List *new_special_subpaths;
2113 
2114  /* Split Parallel Append into partial and non-partial subpaths */
2115  *subpaths = list_concat(*subpaths,
2116  list_copy_tail(apath->subpaths,
2117  apath->first_partial_path));
2118  new_special_subpaths = list_copy_head(apath->subpaths,
2119  apath->first_partial_path);
2120  *special_subpaths = list_concat(*special_subpaths,
2121  new_special_subpaths);
2122  return;
2123  }
2124  }
2125  else if (IsA(path, MergeAppendPath))
2126  {
2127  MergeAppendPath *mpath = (MergeAppendPath *) path;
2128 
2129  *subpaths = list_concat(*subpaths, mpath->subpaths);
2130  return;
2131  }
2132 
2133  *subpaths = lappend(*subpaths, path);
2134 }
2135 
2136 /*
2137  * get_singleton_append_subpath
2138  * Returns the single subpath of an Append/MergeAppend, or just
2139  * return 'path' if it's not a single sub-path Append/MergeAppend.
2140  *
2141  * Note: 'path' must not be a parallel-aware path.
2142  */
2143 static Path *
2144 get_singleton_append_subpath(Path *path)
2145 {
2146  Assert(!path->parallel_aware);
2147 
2148  if (IsA(path, AppendPath))
2149  {
2150  AppendPath *apath = (AppendPath *) path;
2151 
2152  if (list_length(apath->subpaths) == 1)
2153  return (Path *) linitial(apath->subpaths);
2154  }
2155  else if (IsA(path, MergeAppendPath))
2156  {
2157  MergeAppendPath *mpath = (MergeAppendPath *) path;
2158 
2159  if (list_length(mpath->subpaths) == 1)
2160  return (Path *) linitial(mpath->subpaths);
2161  }
2162 
2163  return path;
2164 }
2165 
2166 /*
2167  * set_dummy_rel_pathlist
2168  * Build a dummy path for a relation that's been excluded by constraints
2169  *
2170  * Rather than inventing a special "dummy" path type, we represent this as an
2171  * AppendPath with no members (see also IS_DUMMY_APPEND/IS_DUMMY_REL macros).
2172  *
2173  * (See also mark_dummy_rel, which does basically the same thing, but is
2174  * typically used to change a rel into dummy state after we already made
2175  * paths for it.)
2176  */
2177 static void
2178 set_dummy_rel_pathlist(RelOptInfo *rel)
2179 {
2180  /* Set dummy size estimates --- we leave attr_widths[] as zeroes */
2181  rel->rows = 0;
2182  rel->reltarget->width = 0;
2183 
2184  /* Discard any pre-existing paths; no further need for them */
2185  rel->pathlist = NIL;
2186  rel->partial_pathlist = NIL;
2187 
2188  /* Set up the dummy path */
2189  add_path(rel, (Path *) create_append_path(NULL, rel, NIL, NIL,
2190  NIL, rel->lateral_relids,
2191  0, false, -1));
2192 
2193  /*
2194  * We set the cheapest-path fields immediately, just in case they were
2195  * pointing at some discarded path. This is redundant in current usage
2196  * because set_rel_pathlist will do it later, but it's cheap so we keep it
2197  * for safety and consistency with mark_dummy_rel.
2198  */
2199  set_cheapest(rel);
2200 }
2201 
2202 /*
2203  * find_window_run_conditions
2204  * Determine if 'wfunc' is really a WindowFunc and call its prosupport
2205  * function to determine the function's monotonic properties. We then
2206  * see if 'opexpr' can be used to short-circuit execution.
2207  *
2208  * For example row_number() over (order by ...) always produces a value one
2209  * higher than the previous. If someone has a window function in a subquery
2210  * and has a WHERE clause in the outer query to filter rows <= 10, then we may
2211  * as well stop processing the windowagg once the row number reaches 11. Here
2212  * we check if 'opexpr' might help us to stop doing needless extra processing
2213  * in WindowAgg nodes.
2214  *
2215  * '*keep_original' is set to true if the caller should also use 'opexpr' for
2216  * its original purpose. This is set to false if the caller can assume that
2217  * the run condition will handle all of the required filtering.
2218  *
2219  * Returns true if 'opexpr' was found to be useful and was added to the
2220  * WindowFunc's runCondition. We also set *keep_original accordingly and add
2221  * 'attno' to *run_cond_attrs offset by FirstLowInvalidHeapAttributeNumber.
2222  * If the 'opexpr' cannot be used then we set *keep_original to true and
2223  * return false.
2224  */
2225 static bool
2226 find_window_run_conditions(Query *subquery, RangeTblEntry *rte, Index rti,
2227  AttrNumber attno, WindowFunc *wfunc, OpExpr *opexpr,
2228  bool wfunc_left, bool *keep_original,
2229  Bitmapset **run_cond_attrs)
2230 {
2231  Oid prosupport;
2232  Expr *otherexpr;
2233  SupportRequestWFuncMonotonic req;
2234  SupportRequestWFuncMonotonic *res;
2235  WindowClause *wclause;
2236  List *opinfos;
2237  OpExpr *runopexpr;
2238  Oid runoperator;
2239  ListCell *lc;
2240 
2241  *keep_original = true;
2242 
2243  while (IsA(wfunc, RelabelType))
2244  wfunc = (WindowFunc *) ((RelabelType *) wfunc)->arg;
2245 
2246  /* we can only work with window functions */
2247  if (!IsA(wfunc, WindowFunc))
2248  return false;
2249 
2250  /* can't use it if there are subplans in the WindowFunc */
2251  if (contain_subplans((Node *) wfunc))
2252  return false;
2253 
2254  prosupport = get_func_support(wfunc->winfnoid);
2255 
2256  /* Check if there's a support function for 'wfunc' */
2257  if (!OidIsValid(prosupport))
2258  return false;
2259 
2260  /* get the Expr from the other side of the OpExpr */
2261  if (wfunc_left)
2262  otherexpr = lsecond(opexpr->args);
2263  else
2264  otherexpr = linitial(opexpr->args);
2265 
2266  /*
2267  * The value being compared must not change during the evaluation of the
2268  * window partition.
2269  */
2270  if (!is_pseudo_constant_clause((Node *) otherexpr))
2271  return false;
2272 
2273  /* find the window clause belonging to the window function */
2274  wclause = (WindowClause *) list_nth(subquery->windowClause,
2275  wfunc->winref - 1);
2276 
2277  req.type = T_SupportRequestWFuncMonotonic;
2278  req.window_func = wfunc;
2279  req.window_clause = wclause;
2280 
2281  /* call the support function */
2282  res = (SupportRequestWFuncMonotonic *)
2283  DatumGetPointer(OidFunctionCall1(prosupport,
2284  PointerGetDatum(&req)));
2285 
2286  /*
2287  * Nothing to do if the function is neither monotonically increasing nor
2288  * monotonically decreasing.
2289  */
2290  if (res == NULL || res->monotonic == MONOTONICFUNC_NONE)
2291  return false;
2292 
2293  runopexpr = NULL;
2294  runoperator = InvalidOid;
2295  opinfos = get_op_btree_interpretation(opexpr->opno);
2296 
2297  foreach(lc, opinfos)
2298  {
2299  OpBtreeInterpretation *opinfo = (OpBtreeInterpretation *) lfirst(lc);
2300  int strategy = opinfo->strategy;
2301 
2302  /* handle < / <= */
2303  if (strategy == BTLessStrategyNumber ||
2304  strategy == BTLessEqualStrategyNumber)
2305  {
2306  /*
2307  * < / <= is supported for monotonically increasing functions in
2308  * the form <wfunc> op <pseudoconst> and <pseudoconst> op <wfunc>
2309  * for monotonically decreasing functions.
2310  */
2311  if ((wfunc_left && (res->monotonic & MONOTONICFUNC_INCREASING)) ||
2312  (!wfunc_left && (res->monotonic & MONOTONICFUNC_DECREASING)))
2313  {
2314  *keep_original = false;
2315  runopexpr = opexpr;
2316  runoperator = opexpr->opno;
2317  }
2318  break;
2319  }
2320  /* handle > / >= */
2321  else if (strategy == BTGreaterStrategyNumber ||
2322  strategy == BTGreaterEqualStrategyNumber)
2323  {
2324  /*
2325  * > / >= is supported for monotonically decreasing functions in
2326  * the form <wfunc> op <pseudoconst> and <pseudoconst> op <wfunc>
2327  * for monotonically increasing functions.
2328  */
2329  if ((wfunc_left && (res->monotonic & MONOTONICFUNC_DECREASING)) ||
2330  (!wfunc_left && (res->monotonic & MONOTONICFUNC_INCREASING)))
2331  {
2332  *keep_original = false;
2333  runopexpr = opexpr;
2334  runoperator = opexpr->opno;
2335  }
2336  break;
2337  }
2338  /* handle = */
2339  else if (strategy == BTEqualStrategyNumber)
2340  {
2341  int16 newstrategy;
2342 
2343  /*
2344  * When both monotonically increasing and decreasing then the
2345  * return value of the window function will be the same each time.
2346  * We can simply use 'opexpr' as the run condition without
2347  * modifying it.
2348  */
2349  if ((res->monotonic & MONOTONICFUNC_BOTH) == MONOTONICFUNC_BOTH)
2350  {
2351  *keep_original = false;
2352  runopexpr = opexpr;
2353  runoperator = opexpr->opno;
2354  break;
2355  }
2356 
2357  /*
2358  * When monotonically increasing we make a qual with <wfunc> <=
2359  * <value> or <value> >= <wfunc> in order to filter out values
2360  * which are above the value in the equality condition. For
2361  * monotonically decreasing functions we want to filter values
2362  * below the value in the equality condition.
2363  */
2364  if (res->monotonic & MONOTONICFUNC_INCREASING)
2365  newstrategy = wfunc_left ? BTLessEqualStrategyNumber : BTGreaterEqualStrategyNumber;
2366  else
2367  newstrategy = wfunc_left ? BTGreaterEqualStrategyNumber : BTLessEqualStrategyNumber;
2368 
2369  /* We must keep the original equality qual */
2370  *keep_original = true;
2371  runopexpr = opexpr;
2372 
2373  /* determine the operator to use for the WindowFuncRunCondition */
2374  runoperator = get_opfamily_member(opinfo->opfamily_id,
2375  opinfo->oplefttype,
2376  opinfo->oprighttype,
2377  newstrategy);
2378  break;
2379  }
2380  }
2381 
2382  if (runopexpr != NULL)
2383  {
2384  WindowFuncRunCondition *wfuncrc;
2385 
2386  wfuncrc = makeNode(WindowFuncRunCondition);
2387  wfuncrc->opno = runoperator;
2388  wfuncrc->inputcollid = runopexpr->inputcollid;
2389  wfuncrc->wfunc_left = wfunc_left;
2390  wfuncrc->arg = copyObject(otherexpr);
2391 
2392  wfunc->runCondition = lappend(wfunc->runCondition, wfuncrc);
2393 
2394  /* record that this attno was used in a run condition */
2395  *run_cond_attrs = bms_add_member(*run_cond_attrs,
2396  attno - FirstLowInvalidHeapAttributeNumber);
2397  return true;
2398  }
2399 
2400  /* unsupported OpExpr */
2401  return false;
2402 }
2403 
2404 /*
2405  * check_and_push_window_quals
2406  * Check if 'clause' is a qual that can be pushed into a WindowFunc
2407  * as a 'runCondition' qual. These, when present, allow some unnecessary
2408  * work to be skipped during execution.
2409  *
2410  * 'run_cond_attrs' will be populated with all targetlist resnos of subquery
2411  * targets (offset by FirstLowInvalidHeapAttributeNumber) that we pushed
2412  * window quals for.
2413  *
2414  * Returns true if the caller still must keep the original qual or false if
2415  * the caller can safely ignore the original qual because the WindowAgg node
2416  * will use the runCondition to stop returning tuples.
2417  */
2418 static bool
2419 check_and_push_window_quals(Query *subquery, RangeTblEntry *rte, Index rti,
2420  Node *clause, Bitmapset **run_cond_attrs)
2421 {
2422  OpExpr *opexpr = (OpExpr *) clause;
2423  bool keep_original = true;
2424  Var *var1;
2425  Var *var2;
2426 
2427  /* We're only able to use OpExprs with 2 operands */
2428  if (!IsA(opexpr, OpExpr))
2429  return true;
2430 
2431  if (list_length(opexpr->args) != 2)
2432  return true;
2433 
2434  /*
2435  * Currently, we restrict this optimization to strict OpExprs. The reason
2436  * for this is that during execution, once the runcondition becomes false,
2437  * we stop evaluating WindowFuncs. To avoid leaving around stale window
2438  * function result values, we set them to NULL. Having only strict
2439  * OpExprs here ensures that we properly filter out the tuples with NULLs
2440  * in the top-level WindowAgg.
2441  */
2442  set_opfuncid(opexpr);
2443  if (!func_strict(opexpr->opfuncid))
2444  return true;
2445 
2446  /*
2447  * Check for plain Vars that reference window functions in the subquery.
2448  * If we find any, we'll ask find_window_run_conditions() if 'opexpr' can
2449  * be used as part of the run condition.
2450  */
2451 
2452  /* Check the left side of the OpExpr */
2453  var1 = linitial(opexpr->args);
2454  if (IsA(var1, Var) && var1->varattno > 0)
2455  {
2456  TargetEntry *tle = list_nth(subquery->targetList, var1->varattno - 1);
2457  WindowFunc *wfunc = (WindowFunc *) tle->expr;
2458 
2459  if (find_window_run_conditions(subquery, rte, rti, tle->resno, wfunc,
2460  opexpr, true, &keep_original,
2461  run_cond_attrs))
2462  return keep_original;
2463  }
2464 
2465  /* and check the right side */
2466  var2 = lsecond(opexpr->args);
2467  if (IsA(var2, Var) && var2->varattno > 0)
2468  {
2469  TargetEntry *tle = list_nth(subquery->targetList, var2->varattno - 1);
2470  WindowFunc *wfunc = (WindowFunc *) tle->expr;
2471 
2472  if (find_window_run_conditions(subquery, rte, rti, tle->resno, wfunc,
2473  opexpr, false, &keep_original,
2474  run_cond_attrs))
2475  return keep_original;
2476  }
2477 
2478  return true;
2479 }
2480 
2481 /*
2482  * set_subquery_pathlist
2483  * Generate SubqueryScan access paths for a subquery RTE
2484  *
2485  * We don't currently support generating parameterized paths for subqueries
2486  * by pushing join clauses down into them; it seems too expensive to re-plan
2487  * the subquery multiple times to consider different alternatives.
2488  * (XXX that could stand to be reconsidered, now that we use Paths.)
2489  * So the paths made here will be parameterized if the subquery contains
2490  * LATERAL references, otherwise not. As long as that's true, there's no need
2491  * for a separate set_subquery_size phase: just make the paths right away.
2492  */
2493 static void
2494 set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel,
2495  Index rti, RangeTblEntry *rte)
2496 {
2497  Query *parse = root->parse;
2498  Query *subquery = rte->subquery;
2499  bool trivial_pathtarget;
2500  Relids required_outer;
2501  pushdown_safety_info safetyInfo;
2502  double tuple_fraction;
2503  RelOptInfo *sub_final_rel;
2504  Bitmapset *run_cond_attrs = NULL;
2505  ListCell *lc;
2506 
2507  /*
2508  * Must copy the Query so that planning doesn't mess up the RTE contents
2509  * (really really need to fix the planner to not scribble on its input,
2510  * someday ... but see remove_unused_subquery_outputs to start with).
2511  */
2512  subquery = copyObject(subquery);
2513 
2514  /*
2515  * If it's a LATERAL subquery, it might contain some Vars of the current
2516  * query level, requiring it to be treated as parameterized, even though
2517  * we don't support pushing down join quals into subqueries.
2518  */
2519  required_outer = rel->lateral_relids;
2520 
2521  /*
2522  * Zero out result area for subquery_is_pushdown_safe, so that it can set
2523  * flags as needed while recursing. In particular, we need a workspace
2524  * for keeping track of the reasons why columns are unsafe to reference.
2525  * These reasons are stored in the bits inside unsafeFlags[i] when we
2526  * discover reasons that column i of the subquery is unsafe to be used in
2527  * a pushed-down qual.
2528  */
2529  memset(&safetyInfo, 0, sizeof(safetyInfo));
2530  safetyInfo.unsafeFlags = (unsigned char *)
2531  palloc0((list_length(subquery->targetList) + 1) * sizeof(unsigned char));
2532 
2533  /*
2534  * If the subquery has the "security_barrier" flag, it means the subquery
2535  * originated from a view that must enforce row-level security. Then we
2536  * must not push down quals that contain leaky functions. (Ideally this
2537  * would be checked inside subquery_is_pushdown_safe, but since we don't
2538  * currently pass the RTE to that function, we must do it here.)
2539  */
2540  safetyInfo.unsafeLeaky = rte->security_barrier;
2541 
2542  /*
2543  * If there are any restriction clauses that have been attached to the
2544  * subquery relation, consider pushing them down to become WHERE or HAVING
2545  * quals of the subquery itself. This transformation is useful because it
2546  * may allow us to generate a better plan for the subquery than evaluating
2547  * all the subquery output rows and then filtering them.
2548  *
2549  * There are several cases where we cannot push down clauses. Restrictions
2550  * involving the subquery are checked by subquery_is_pushdown_safe().
2551  * Restrictions on individual clauses are checked by
2552  * qual_is_pushdown_safe(). Also, we don't want to push down
2553  * pseudoconstant clauses; better to have the gating node above the
2554  * subquery.
2555  *
2556  * Non-pushed-down clauses will get evaluated as qpquals of the
2557  * SubqueryScan node.
2558  *
2559  * XXX Are there any cases where we want to make a policy decision not to
2560  * push down a pushable qual, because it'd result in a worse plan?
2561  */
2562  if (rel->baserestrictinfo != NIL &&
2563  subquery_is_pushdown_safe(subquery, subquery, &safetyInfo))
2564  {
2565  /* OK to consider pushing down individual quals */
2566  List *upperrestrictlist = NIL;
2567  ListCell *l;
2568 
2569  foreach(l, rel->baserestrictinfo)
2570  {
2571  RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
2572  Node *clause = (Node *) rinfo->clause;
2573 
2574  if (rinfo->pseudoconstant)
2575  {
2576  upperrestrictlist = lappend(upperrestrictlist, rinfo);
2577  continue;
2578  }
2579 
2580  switch (qual_is_pushdown_safe(subquery, rti, rinfo, &safetyInfo))
2581  {
2582  case PUSHDOWN_SAFE:
2583  /* Push it down */
2584  subquery_push_qual(subquery, rte, rti, clause);
2585  break;
2586 
2587  case PUSHDOWN_WINDOWCLAUSE_RUNCOND:
2588 
2589  /*
2590  * Since we can't push the qual down into the subquery,
2591  * check if it happens to reference a window function. If
2592  * so then it might be useful to use for the WindowAgg's
2593  * runCondition.
2594  */
2595  if (!subquery->hasWindowFuncs ||
2596  check_and_push_window_quals(subquery, rte, rti, clause,
2597  &run_cond_attrs))
2598  {
2599  /*
2600  * subquery has no window funcs or the clause is not a
2601  * suitable window run condition qual or it is, but
2602  * the original must also be kept in the upper query.
2603  */
2604  upperrestrictlist = lappend(upperrestrictlist, rinfo);
2605  }
2606  break;
2607 
2608  case PUSHDOWN_UNSAFE:
2609  upperrestrictlist = lappend(upperrestrictlist, rinfo);
2610  break;
2611  }
2612  }
2613  rel->baserestrictinfo = upperrestrictlist;
2614  /* We don't bother recomputing baserestrict_min_security */
2615  }
2616 
2617  pfree(safetyInfo.unsafeFlags);
2618 
2619  /*
2620  * The upper query might not use all the subquery's output columns; if
2621  * not, we can simplify. Pass the attributes that were pushed down into
2622  * WindowAgg run conditions to ensure we don't accidentally think those
2623  * are unused.
2624  */
2625  remove_unused_subquery_outputs(subquery, rel, run_cond_attrs);
2626 
2627  /*
2628  * We can safely pass the outer tuple_fraction down to the subquery if the
2629  * outer level has no joining, aggregation, or sorting to do. Otherwise
2630  * we'd better tell the subquery to plan for full retrieval. (XXX This
2631  * could probably be made more intelligent ...)
2632  */
2633  if (parse->hasAggs ||
2634  parse->groupClause ||
2635  parse->groupingSets ||
2636  root->hasHavingQual ||
2637  parse->distinctClause ||
2638  parse->sortClause ||
2639  bms_membership(root->all_baserels) == BMS_MULTIPLE)
2640  tuple_fraction = 0.0; /* default case */
2641  else
2642  tuple_fraction = root->tuple_fraction;
2643 
2644  /* plan_params should not be in use in current query level */
2645  Assert(root->plan_params == NIL);
2646 
2647  /* Generate a subroot and Paths for the subquery */
2648  rel->subroot = subquery_planner(root->glob, subquery, root, false,
2649  tuple_fraction, NULL);
2650 
2651  /* Isolate the params needed by this specific subplan */
2652  rel->subplan_params = root->plan_params;
2653  root->plan_params = NIL;
2654 
2655  /*
2656  * It's possible that constraint exclusion proved the subquery empty. If
2657  * so, it's desirable to produce an unadorned dummy path so that we will
2658  * recognize appropriate optimizations at this query level.
2659  */
2660  sub_final_rel = fetch_upper_rel(rel->subroot, UPPERREL_FINAL, NULL);
2661 
2662  if (IS_DUMMY_REL(sub_final_rel))
2663  {
2664  set_dummy_rel_pathlist(rel);
2665  return;
2666  }
2667 
2668  /*
2669  * Mark rel with estimated output rows, width, etc. Note that we have to
2670  * do this before generating outer-query paths, else cost_subqueryscan is
2671  * not happy.
2672  */
2673  set_subquery_size_estimates(root, rel);
2674 
2675  /*
2676  * Also detect whether the reltarget is trivial, so that we can pass that
2677  * info to cost_subqueryscan (rather than re-deriving it multiple times).
2678  * It's trivial if it fetches all the subplan output columns in order.
2679  */
2680  if (list_length(rel->reltarget->exprs) != list_length(subquery->targetList))
2681  trivial_pathtarget = false;
2682  else
2683  {
2684  trivial_pathtarget = true;
2685  foreach(lc, rel->reltarget->exprs)
2686  {
2687  Node *node = (Node *) lfirst(lc);
2688  Var *var;
2689 
2690  if (!IsA(node, Var))
2691  {
2692  trivial_pathtarget = false;
2693  break;
2694  }
2695  var = (Var *) node;
2696  if (var->varno != rti ||
2697  var->varattno != foreach_current_index(lc) + 1)
2698  {
2699  trivial_pathtarget = false;
2700  break;
2701  }
2702  }
2703  }
2704 
2705  /*
2706  * For each Path that subquery_planner produced, make a SubqueryScanPath
2707  * in the outer query.
2708  */
2709  foreach(lc, sub_final_rel->pathlist)
2710  {
2711  Path *subpath = (Path *) lfirst(lc);
2712  List *pathkeys;
2713 
2714  /* Convert subpath's pathkeys to outer representation */
2715  pathkeys = convert_subquery_pathkeys(root,
2716  rel,
2717  subpath->pathkeys,
2718  make_tlist_from_pathtarget(subpath->pathtarget));
2719 
2720  /* Generate outer path using this subpath */
2721  add_path(rel, (Path *)
2722  create_subqueryscan_path(root, rel, subpath,
2723  trivial_pathtarget,
2724  pathkeys, required_outer));
2725  }
2726 
2727  /* If outer rel allows parallelism, do same for partial paths. */
2728  if (rel->consider_parallel && bms_is_empty(required_outer))
2729  {
2730  /* If consider_parallel is false, there should be no partial paths. */
2731  Assert(sub_final_rel->consider_parallel ||
2732  sub_final_rel->partial_pathlist == NIL);
2733 
2734  /* Same for partial paths. */
2735  foreach(lc, sub_final_rel->partial_pathlist)
2736  {
2737  Path *subpath = (Path *) lfirst(lc);
2738  List *pathkeys;
2739 
2740  /* Convert subpath's pathkeys to outer representation */
2741  pathkeys = convert_subquery_pathkeys(root,
2742  rel,
2743  subpath->pathkeys,
2744  make_tlist_from_pathtarget(subpath->pathtarget));
2745 
2746  /* Generate outer path using this subpath */
2747  add_partial_path(rel, (Path *)
2748  create_subqueryscan_path(root, rel, subpath,
2749  trivial_pathtarget,
2750  pathkeys,
2751  required_outer));
2752  }
2753  }
2754 }
2755 
2756 /*
2757  * set_function_pathlist
2758  * Build the (single) access path for a function RTE
2759  */
2760 static void
2761 set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2762 {
2763  Relids required_outer;
2764  List *pathkeys = NIL;
2765 
2766  /*
2767  * We don't support pushing join clauses into the quals of a function
2768  * scan, but it could still have required parameterization due to LATERAL
2769  * refs in the function expression.
2770  */
2771  required_outer = rel->lateral_relids;
2772 
2773  /*
2774  * The result is considered unordered unless ORDINALITY was used, in which
2775  * case it is ordered by the ordinal column (the last one). See if we
2776  * care, by checking for uses of that Var in equivalence classes.
2777  */
2778  if (rte->funcordinality)
2779  {
2780  AttrNumber ordattno = rel->max_attr;
2781  Var *var = NULL;
2782  ListCell *lc;
2783 
2784  /*
2785  * Is there a Var for it in rel's targetlist? If not, the query did
2786  * not reference the ordinality column, or at least not in any way
2787  * that would be interesting for sorting.
2788  */
2789  foreach(lc, rel->reltarget->exprs)
2790  {
2791  Var *node = (Var *) lfirst(lc);
2792 
2793  /* checking varno/varlevelsup is just paranoia */
2794  if (IsA(node, Var) &&
2795  node->varattno == ordattno &&
2796  node->varno == rel->relid &&
2797  node->varlevelsup == 0)
2798  {
2799  var = node;
2800  break;
2801  }
2802  }
2803 
2804  /*
2805  * Try to build pathkeys for this Var with int8 sorting. We tell
2806  * build_expression_pathkey not to build any new equivalence class; if
2807  * the Var isn't already mentioned in some EC, it means that nothing
2808  * cares about the ordering.
2809  */
2810  if (var)
2811  pathkeys = build_expression_pathkey(root,
2812  (Expr *) var,
2813  Int8LessOperator,
2814  rel->relids,
2815  false);
2816  }
2817 
2818  /* Generate appropriate path */
2819  add_path(rel, create_functionscan_path(root, rel,
2820  pathkeys, required_outer));
2821 }
2822 
2823 /*
2824  * set_values_pathlist
2825  * Build the (single) access path for a VALUES RTE
2826  */
2827 static void
2828 set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2829 {
2830  Relids required_outer;
2831 
2832  /*
2833  * We don't support pushing join clauses into the quals of a values scan,
2834  * but it could still have required parameterization due to LATERAL refs
2835  * in the values expressions.
2836  */
2837  required_outer = rel->lateral_relids;
2838 
2839  /* Generate appropriate path */
2840  add_path(rel, create_valuesscan_path(root, rel, required_outer));
2841 }
2842 
2843 /*
2844  * set_tablefunc_pathlist
2845  * Build the (single) access path for a table func RTE
2846  */
2847 static void
2848 set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2849 {
2850  Relids required_outer;
2851 
2852  /*
2853  * We don't support pushing join clauses into the quals of a tablefunc
2854  * scan, but it could still have required parameterization due to LATERAL
2855  * refs in the function expression.
2856  */
2857  required_outer = rel->lateral_relids;
2858 
2859  /* Generate appropriate path */
2860  add_path(rel, create_tablefuncscan_path(root, rel,
2861  required_outer));
2862 }
2863 
2864 /*
2865  * set_cte_pathlist
2866  * Build the (single) access path for a non-self-reference CTE RTE
2867  *
2868  * There's no need for a separate set_cte_size phase, since we don't
2869  * support join-qual-parameterized paths for CTEs.
2870  */
2871 static void
2872 set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2873 {
2874  Path *ctepath;
2875  Plan *cteplan;
2876  PlannerInfo *cteroot;
2877  Index levelsup;
2878  List *pathkeys;
2879  int ndx;
2880  ListCell *lc;
2881  int plan_id;
2882  Relids required_outer;
2883 
2884  /*
2885  * Find the referenced CTE, and locate the path and plan previously made
2886  * for it.
2887  */
2888  levelsup = rte->ctelevelsup;
2889  cteroot = root;
2890  while (levelsup-- > 0)
2891  {
2892  cteroot = cteroot->parent_root;
2893  if (!cteroot) /* shouldn't happen */
2894  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
2895  }
2896 
2897  /*
2898  * Note: cte_plan_ids can be shorter than cteList, if we are still working
2899  * on planning the CTEs (ie, this is a side-reference from another CTE).
2900  * So we mustn't use forboth here.
2901  */
2902  ndx = 0;
2903  foreach(lc, cteroot->parse->cteList)
2904  {
2905  CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
2906 
2907  if (strcmp(cte->ctename, rte->ctename) == 0)
2908  break;
2909  ndx++;
2910  }
2911  if (lc == NULL) /* shouldn't happen */
2912  elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
2913  if (ndx >= list_length(cteroot->cte_plan_ids))
2914  elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
2915  plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
2916  if (plan_id <= 0)
2917  elog(ERROR, "no plan was made for CTE \"%s\"", rte->ctename);
2918 
2919  Assert(list_length(root->glob->subpaths) == list_length(root->glob->subplans));
2920  ctepath = (Path *) list_nth(root->glob->subpaths, plan_id - 1);
2921  cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1);
2922 
2923  /* Mark rel with estimated output rows, width, etc */
2924  set_cte_size_estimates(root, rel, cteplan->plan_rows);
2925 
2926  /* Convert the ctepath's pathkeys to outer query's representation */
2927  pathkeys = convert_subquery_pathkeys(root,
2928  rel,
2929  ctepath->pathkeys,
2930  cteplan->targetlist);
2931 
2932  /*
2933  * We don't support pushing join clauses into the quals of a CTE scan, but
2934  * it could still have required parameterization due to LATERAL refs in
2935  * its tlist.
2936  */
2937  required_outer = rel->lateral_relids;
2938 
2939  /* Generate appropriate path */
2940  add_path(rel, create_ctescan_path(root, rel, pathkeys, required_outer));
2941 }
2942 
2943 /*
2944  * set_namedtuplestore_pathlist
2945  * Build the (single) access path for a named tuplestore RTE
2946  *
2947  * There's no need for a separate set_namedtuplestore_size phase, since we
2948  * don't support join-qual-parameterized paths for tuplestores.
2949  */
2950 static void
2951 set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel,
2952  RangeTblEntry *rte)
2953 {
2954  Relids required_outer;
2955 
2956  /* Mark rel with estimated output rows, width, etc */
2957  set_namedtuplestore_size_estimates(root, rel);
2958 
2959  /*
2960  * We don't support pushing join clauses into the quals of a tuplestore
2961  * scan, but it could still have required parameterization due to LATERAL
2962  * refs in its tlist.
2963  */
2964  required_outer = rel->lateral_relids;
2965 
2966  /* Generate appropriate path */
2967  add_path(rel, create_namedtuplestorescan_path(root, rel, required_outer));
2968 }
2969 
2970 /*
2971  * set_result_pathlist
2972  * Build the (single) access path for an RTE_RESULT RTE
2973  *
2974  * There's no need for a separate set_result_size phase, since we
2975  * don't support join-qual-parameterized paths for these RTEs.
2976  */
2977 static void
2978 set_result_pathlist(PlannerInfo *root, RelOptInfo *rel,
2979  RangeTblEntry *rte)
2980 {
2981  Relids required_outer;
2982 
2983  /* Mark rel with estimated output rows, width, etc */
2984  set_result_size_estimates(root, rel);
2985 
2986  /*
2987  * We don't support pushing join clauses into the quals of a Result scan,
2988  * but it could still have required parameterization due to LATERAL refs
2989  * in its tlist.
2990  */
2991  required_outer = rel->lateral_relids;
2992 
2993  /* Generate appropriate path */
2994  add_path(rel, create_resultscan_path(root, rel, required_outer));
2995 }
2996 
2997 /*
2998  * set_worktable_pathlist
2999  * Build the (single) access path for a self-reference CTE RTE
3000  *
3001  * There's no need for a separate set_worktable_size phase, since we don't
3002  * support join-qual-parameterized paths for CTEs.
3003  */
3004 static void
3005 set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
3006 {
3007  Path *ctepath;
3008  PlannerInfo *cteroot;
3009  Index levelsup;
3010  Relids required_outer;
3011 
3012  /*
3013  * We need to find the non-recursive term's path, which is in the plan
3014  * level that's processing the recursive UNION, which is one level *below*
3015  * where the CTE comes from.
3016  */
3017  levelsup = rte->ctelevelsup;
3018  if (levelsup == 0) /* shouldn't happen */
3019  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
3020  levelsup--;
3021  cteroot = root;
3022  while (levelsup-- > 0)
3023  {
3024  cteroot = cteroot->parent_root;
3025  if (!cteroot) /* shouldn't happen */
3026  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
3027  }
3028  ctepath = cteroot->non_recursive_path;
3029  if (!ctepath) /* shouldn't happen */
3030  elog(ERROR, "could not find path for CTE \"%s\"", rte->ctename);
3031 
3032  /* Mark rel with estimated output rows, width, etc */
3033  set_cte_size_estimates(root, rel, ctepath->rows);
3034 
3035  /*
3036  * We don't support pushing join clauses into the quals of a worktable
3037  * scan, but it could still have required parameterization due to LATERAL
3038  * refs in its tlist. (I'm not sure this is actually possible given the
3039  * restrictions on recursive references, but it's easy enough to support.)
3040  */
3041  required_outer = rel->lateral_relids;
3042 
3043  /* Generate appropriate path */
3044  add_path(rel, create_worktablescan_path(root, rel, required_outer));
3045 }
3046 
3047 /*
3048  * generate_gather_paths
3049  * Generate parallel access paths for a relation by pushing a Gather or
3050  * Gather Merge on top of a partial path.
3051  *
3052  * This must not be called until after we're done creating all partial paths
3053  * for the specified relation. (Otherwise, add_partial_path might delete a
3054  * path that some GatherPath or GatherMergePath has a reference to.)
3055  *
3056  * If we're generating paths for a scan or join relation, override_rows will
3057  * be false, and we'll just use the relation's size estimate. When we're
3058  * being called for a partially-grouped or partially-distinct path, though, we
3059  * need to override the rowcount estimate. (It's not clear that the
3060  * particular value we're using here is actually best, but the underlying rel
3061  * has no estimate so we must do something.)
3062  */
3063 void
3064 generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
3065 {
3066  Path *cheapest_partial_path;
3067  Path *simple_gather_path;
3068  ListCell *lc;
3069  double rows;
3070  double *rowsp = NULL;
3071 
3072  /* If there are no partial paths, there's nothing to do here. */
3073  if (rel->partial_pathlist == NIL)
3074  return;
3075 
3076  /* Should we override the rel's rowcount estimate? */
3077  if (override_rows)
3078  rowsp = &rows;
3079 
3080  /*
3081  * The output of Gather is always unsorted, so there's only one partial
3082  * path of interest: the cheapest one. That will be the one at the front
3083  * of partial_pathlist because of the way add_partial_path works.
3084  */
3085  cheapest_partial_path = linitial(rel->partial_pathlist);
3086  rows = compute_gather_rows(cheapest_partial_path);
3087  simple_gather_path = (Path *)
3088  create_gather_path(root, rel, cheapest_partial_path, rel->reltarget,
3089  NULL, rowsp);
3090  add_path(rel, simple_gather_path);
3091 
3092  /*
3093  * For each useful ordering, we can consider an order-preserving Gather
3094  * Merge.
3095  */
3096  foreach(lc, rel->partial_pathlist)
3097  {
3098  Path *subpath = (Path *) lfirst(lc);
3099  GatherMergePath *path;
3100 
3101  if (subpath->pathkeys == NIL)
3102  continue;
3103 
3104  rows = compute_gather_rows(subpath);
3105  path = create_gather_merge_path(root, rel, subpath, rel->reltarget,
3106  subpath->pathkeys, NULL, rowsp);
3107  add_path(rel, &path->path);
3108  }
3109 }
3110 
3111 /*
3112  * get_useful_pathkeys_for_relation
3113  * Determine which orderings of a relation might be useful.
3114  *
3115  * Getting data in sorted order can be useful either because the requested
3116  * order matches the final output ordering for the overall query we're
3117  * planning, or because it enables an efficient merge join. Here, we try
3118  * to figure out which pathkeys to consider.
3119  *
3120  * This allows us to do incremental sort on top of an index scan under a gather
3121  * merge node, i.e. parallelized.
3122  *
3123  * If the require_parallel_safe is true, we also require the expressions to
3124  * be parallel safe (which allows pushing the sort below Gather Merge).
3125  *
3126  * XXX At the moment this can only ever return a list with a single element,
3127  * because it looks at query_pathkeys only. So we might return the pathkeys
3128  * directly, but it seems plausible we'll want to consider other orderings
3129  * in the future. For example, we might want to consider pathkeys useful for
3130  * merge joins.
3131  */
3132 static List *
3133 get_useful_pathkeys_for_relation(PlannerInfo *root, RelOptInfo *rel,
3134  bool require_parallel_safe)
3135 {
3136  List *useful_pathkeys_list = NIL;
3137 
3138  /*
3139  * Considering query_pathkeys is always worth it, because it might allow
3140  * us to avoid a total sort when we have a partially presorted path
3141  * available or to push the total sort into the parallel portion of the
3142  * query.
3143  */
3144  if (root->query_pathkeys)
3145  {
3146  ListCell *lc;
3147  int npathkeys = 0; /* useful pathkeys */
3148 
3149  foreach(lc, root->query_pathkeys)
3150  {
3151  PathKey *pathkey = (PathKey *) lfirst(lc);
3152  EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
3153 
3154  /*
3155  * We can only build a sort for pathkeys that contain a
3156  * safe-to-compute-early EC member computable from the current
3157  * relation's reltarget, so ignore the remainder of the list as
3158  * soon as we find a pathkey without such a member.
3159  *
3160  * It's still worthwhile to return any prefix of the pathkeys list
3161  * that meets this requirement, as we may be able to do an
3162  * incremental sort.
3163  *
3164  * If requested, ensure the sort expression is parallel-safe too.
3165  */
3166  if (!relation_can_be_sorted_early(root, rel, pathkey_ec,
3167  require_parallel_safe))
3168  break;
3169 
3170  npathkeys++;
3171  }
3172 
3173  /*
3174  * The whole query_pathkeys list matches, so append it directly, to
3175  * allow comparing pathkeys easily by comparing list pointer. If we
3176  * have to truncate the pathkeys, we gotta do a copy though.
3177  */
3178  if (npathkeys == list_length(root->query_pathkeys))
3179  useful_pathkeys_list = lappend(useful_pathkeys_list,
3180  root->query_pathkeys);
3181  else if (npathkeys > 0)
3182  useful_pathkeys_list = lappend(useful_pathkeys_list,
3183  list_copy_head(root->query_pathkeys,
3184  npathkeys));
3185  }
3186 
3187  return useful_pathkeys_list;
3188 }
3189 
3190 /*
3191  * generate_useful_gather_paths
3192  * Generate parallel access paths for a relation by pushing a Gather or
3193  * Gather Merge on top of a partial path.
3194  *
3195  * Unlike plain generate_gather_paths, this looks both at pathkeys of input
3196  * paths (aiming to preserve the ordering), but also considers ordering that
3197  * might be useful for nodes above the gather merge node, and tries to add
3198  * a sort (regular or incremental) to provide that.
3199  */
3200 void
3201 generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
3202 {
3203  ListCell *lc;
3204  double rows;
3205  double *rowsp = NULL;
3206  List *useful_pathkeys_list = NIL;
3207  Path *cheapest_partial_path = NULL;
3208 
3209  /* If there are no partial paths, there's nothing to do here. */
3210  if (rel->partial_pathlist == NIL)
3211  return;
3212 
3213  /* Should we override the rel's rowcount estimate? */
3214  if (override_rows)
3215  rowsp = &rows;
3216 
3217  /* generate the regular gather (merge) paths */
3218  generate_gather_paths(root, rel, override_rows);
3219 
3220  /* consider incremental sort for interesting orderings */
3221  useful_pathkeys_list = get_useful_pathkeys_for_relation(root, rel, true);
3222 
3223  /* used for explicit (full) sort paths */
3224  cheapest_partial_path = linitial(rel->partial_pathlist);
3225 
3226  /*
3227  * Consider sorted paths for each interesting ordering. We generate both
3228  * incremental and full sort.
3229  */
3230  foreach(lc, useful_pathkeys_list)
3231  {
3232  List *useful_pathkeys = lfirst(lc);
3233  ListCell *lc2;
3234  bool is_sorted;
3235  int presorted_keys;
3236 
3237  foreach(lc2, rel->partial_pathlist)
3238  {
3239  Path *subpath = (Path *) lfirst(lc2);
3240  GatherMergePath *path;
3241 
3242  is_sorted = pathkeys_count_contained_in(useful_pathkeys,
3243  subpath->pathkeys,
3244  &presorted_keys);
3245 
3246  /*
3247  * We don't need to consider the case where a subpath is already
3248  * fully sorted because generate_gather_paths already creates a
3249  * gather merge path for every subpath that has pathkeys present.
3250  *
3251  * But since the subpath is already sorted, we know we don't need
3252  * to consider adding a sort (full or incremental) on top of it,
3253  * so we can continue here.
3254  */
3255  if (is_sorted)
3256  continue;
3257 
3258  /*
3259  * Try at least sorting the cheapest path and also try
3260  * incrementally sorting any path which is partially sorted
3261  * already (no need to deal with paths which have presorted keys
3262  * when incremental sort is disabled unless it's the cheapest
3263  * input path).
3264  */
3265  if (subpath != cheapest_partial_path &&
3266  (presorted_keys == 0 || !enable_incremental_sort))
3267  continue;
3268 
3269  /*
3270  * Consider regular sort for any path that's not presorted or if
3271  * incremental sort is disabled. We've no need to consider both
3272  * sort and incremental sort on the same path. We assume that
3273  * incremental sort is always faster when there are presorted
3274  * keys.
3275  *
3276  * This is not redundant with the gather paths created in
3277  * generate_gather_paths, because that doesn't generate ordered
3278  * output. Here we add an explicit sort to match the useful
3279  * ordering.
3280  */
3281  if (presorted_keys == 0 || !enable_incremental_sort)
3282  {
3283  subpath = (Path *) create_sort_path(root,
3284  rel,
3285  subpath,
3286  useful_pathkeys,
3287  -1.0);
3288  }
3289  else
3290  subpath = (Path *) create_incremental_sort_path(root,
3291  rel,
3292  subpath,
3293  useful_pathkeys,
3294  presorted_keys,
3295  -1);
3296  rows = compute_gather_rows(subpath);
3297  path = create_gather_merge_path(root, rel,
3298  subpath,
3299  rel->reltarget,
3300  subpath->pathkeys,
3301  NULL,
3302  rowsp);
3303 
3304  add_path(rel, &path->path);
3305  }
3306  }
3307 }
3308 
3309 /*
3310  * make_rel_from_joinlist
3311  * Build access paths using a "joinlist" to guide the join path search.
3312  *
3313  * See comments for deconstruct_jointree() for definition of the joinlist
3314  * data structure.
3315  */
3316 static RelOptInfo *
3317 make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
3318 {
3319  int levels_needed;
3320  List *initial_rels;
3321  ListCell *jl;
3322 
3323  /*
3324  * Count the number of child joinlist nodes. This is the depth of the
3325  * dynamic-programming algorithm we must employ to consider all ways of
3326  * joining the child nodes.
3327  */
3328  levels_needed = list_length(joinlist);
3329 
3330  if (levels_needed <= 0)
3331  return NULL; /* nothing to do? */
3332 
3333  /*
3334  * Construct a list of rels corresponding to the child joinlist nodes.
3335  * This may contain both base rels and rels constructed according to
3336  * sub-joinlists.
3337  */
3338  initial_rels = NIL;
3339  foreach(jl, joinlist)
3340  {
3341  Node *jlnode = (Node *) lfirst(jl);
3342  RelOptInfo *thisrel;
3343 
3344  if (IsA(jlnode, RangeTblRef))
3345  {
3346  int varno = ((RangeTblRef *) jlnode)->rtindex;
3347 
3348  thisrel = find_base_rel(root, varno);
3349  }
3350  else if (IsA(jlnode, List))
3351  {
3352  /* Recurse to handle subproblem */
3353  thisrel = make_rel_from_joinlist(root, (List *) jlnode);
3354  }
3355  else
3356  {
3357  elog(ERROR, "unrecognized joinlist node type: %d",
3358  (int) nodeTag(jlnode));
3359  thisrel = NULL; /* keep compiler quiet */
3360  }
3361 
3362  initial_rels = lappend(initial_rels, thisrel);
3363  }
3364 
3365  if (levels_needed == 1)
3366  {
3367  /*
3368  * Single joinlist node, so we're done.
3369  */
3370  return (RelOptInfo *) linitial(initial_rels);
3371  }
3372  else
3373  {
3374  /*
3375  * Consider the different orders in which we could join the rels,
3376  * using a plugin, GEQO, or the regular join search code.
3377  *
3378  * We put the initial_rels list into a PlannerInfo field because
3379  * has_legal_joinclause() needs to look at it (ugly :-().
3380  */
3381  root->initial_rels = initial_rels;
3382 
3383  if (join_search_hook)
3384  return (*join_search_hook) (root, levels_needed, initial_rels);
3385  else if (enable_geqo && levels_needed >= geqo_threshold)
3386  return geqo(root, levels_needed, initial_rels);
3387  else
3388  return standard_join_search(root, levels_needed, initial_rels);
3389  }
3390 }
3391 
3392 /*
3393  * standard_join_search
3394  * Find possible joinpaths for a query by successively finding ways
3395  * to join component relations into join relations.
3396  *
3397  * 'levels_needed' is the number of iterations needed, ie, the number of
3398  * independent jointree items in the query. This is > 1.
3399  *
3400  * 'initial_rels' is a list of RelOptInfo nodes for each independent
3401  * jointree item. These are the components to be joined together.
3402  * Note that levels_needed == list_length(initial_rels).
3403  *
3404  * Returns the final level of join relations, i.e., the relation that is
3405  * the result of joining all the original relations together.
3406  * At least one implementation path must be provided for this relation and
3407  * all required sub-relations.
3408  *
3409  * To support loadable plugins that modify planner behavior by changing the
3410  * join searching algorithm, we provide a hook variable that lets a plugin
3411  * replace or supplement this function. Any such hook must return the same
3412  * final join relation as the standard code would, but it might have a
3413  * different set of implementation paths attached, and only the sub-joinrels
3414  * needed for these paths need have been instantiated.
3415  *
3416  * Note to plugin authors: the functions invoked during standard_join_search()
3417  * modify root->join_rel_list and root->join_rel_hash. If you want to do more
3418  * than one join-order search, you'll probably need to save and restore the
3419  * original states of those data structures. See geqo_eval() for an example.
3420  */
3421 RelOptInfo *
3422 standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
3423 {
3424  int lev;
3425  RelOptInfo *rel;
3426 
3427  /*
3428  * This function cannot be invoked recursively within any one planning
3429  * problem, so join_rel_level[] can't be in use already.
3430  */
3431  Assert(root->join_rel_level == NULL);
3432 
3433  /*
3434  * We employ a simple "dynamic programming" algorithm: we first find all
3435  * ways to build joins of two jointree items, then all ways to build joins
3436  * of three items (from two-item joins and single items), then four-item
3437  * joins, and so on until we have considered all ways to join all the
3438  * items into one rel.
3439  *
3440  * root->join_rel_level[j] is a list of all the j-item rels. Initially we
3441  * set root->join_rel_level[1] to represent all the single-jointree-item
3442  * relations.
3443  */
3444  root->join_rel_level = (List **) palloc0((levels_needed + 1) * sizeof(List *));
3445 
3446  root->join_rel_level[1] = initial_rels;
3447 
3448  for (lev = 2; lev <= levels_needed; lev++)
3449  {
3450  ListCell *lc;
3451 
3452  /*
3453  * Determine all possible pairs of relations to be joined at this
3454  * level, and build paths for making each one from every available
3455  * pair of lower-level relations.
3456  */
3457  join_search_one_level(root, lev);
3458 
3459  /*
3460  * Run generate_partitionwise_join_paths() and
3461  * generate_useful_gather_paths() for each just-processed joinrel. We
3462  * could not do this earlier because both regular and partial paths
3463  * can get added to a particular joinrel at multiple times within
3464  * join_search_one_level.
3465  *
3466  * After that, we're done creating paths for the joinrel, so run
3467  * set_cheapest().
3468  */
3469  foreach(lc, root->join_rel_level[lev])
3470  {
3471  rel = (RelOptInfo *) lfirst(lc);
3472 
3473  /* Create paths for partitionwise joins. */
3474  generate_partitionwise_join_paths(root, rel);
3475 
3476  /*
3477  * Except for the topmost scan/join rel, consider gathering
3478  * partial paths. We'll do the same for the topmost scan/join rel
3479  * once we know the final targetlist (see grouping_planner's and
3480  * its call to apply_scanjoin_target_to_paths).
3481  */
3482  if (!bms_equal(rel->relids, root->all_query_rels))
3483  generate_useful_gather_paths(root, rel, false);
3484 
3485  /* Find and save the cheapest paths for this rel */
3486  set_cheapest(rel);
3487 
3488 #ifdef OPTIMIZER_DEBUG
3489  pprint(rel);
3490 #endif
3491  }
3492  }
3493 
3494  /*
3495  * We should have a single rel at the final level.
3496  */
3497  if (root->join_rel_level[levels_needed] == NIL)
3498  elog(ERROR, "failed to build any %d-way joins", levels_needed);
3499  Assert(list_length(root->join_rel_level[levels_needed]) == 1);
3500 
3501  rel = (RelOptInfo *) linitial(root->join_rel_level[levels_needed]);
3502 
3503  root->join_rel_level = NULL;
3504 
3505  return rel;
3506 }
3507 
3508 /*****************************************************************************
3509  * PUSHING QUALS DOWN INTO SUBQUERIES
3510  *****************************************************************************/
3511 
3512 /*
3513  * subquery_is_pushdown_safe - is a subquery safe for pushing down quals?
3514  *
3515  * subquery is the particular component query being checked. topquery
3516  * is the top component of a set-operations tree (the same Query if no
3517  * set-op is involved).
3518  *
3519  * Conditions checked here:
3520  *
3521  * 1. If the subquery has a LIMIT clause, we must not push down any quals,
3522  * since that could change the set of rows returned.
3523  *
3524  * 2. If the subquery contains EXCEPT or EXCEPT ALL set ops we cannot push
3525  * quals into it, because that could change the results.
3526  *
3527  * 3. If the subquery uses DISTINCT, we cannot push volatile quals into it.
3528  * This is because upper-level quals should semantically be evaluated only
3529  * once per distinct row, not once per original row, and if the qual is
3530  * volatile then extra evaluations could change the results. (This issue
3531  * does not apply to other forms of aggregation such as GROUP BY, because
3532  * when those are present we push into HAVING not WHERE, so that the quals
3533  * are still applied after aggregation.)
3534  *
3535  * 4. If the subquery contains window functions, we cannot push volatile quals
3536  * into it. The issue here is a bit different from DISTINCT: a volatile qual
3537  * might succeed for some rows of a window partition and fail for others,
3538  * thereby changing the partition contents and thus the window functions'
3539  * results for rows that remain.
3540  *
3541  * 5. If the subquery contains any set-returning functions in its targetlist,
3542  * we cannot push volatile quals into it. That would push them below the SRFs
3543  * and thereby change the number of times they are evaluated. Also, a
3544  * volatile qual could succeed for some SRF output rows and fail for others,
3545  * a behavior that cannot occur if it's evaluated before SRF expansion.
3546  *
3547  * 6. If the subquery has nonempty grouping sets, we cannot push down any
3548  * quals. The concern here is that a qual referencing a "constant" grouping
3549  * column could get constant-folded, which would be improper because the value
3550  * is potentially nullable by grouping-set expansion. This restriction could
3551  * be removed if we had a parsetree representation that shows that such
3552  * grouping columns are not really constant. (There are other ideas that
3553  * could be used to relax this restriction, but that's the approach most
3554  * likely to get taken in the future. Note that there's not much to be gained
3555  * so long as subquery_planner can't move HAVING clauses to WHERE within such
3556  * a subquery.)
3557  *
3558  * In addition, we make several checks on the subquery's output columns to see
3559  * if it is safe to reference them in pushed-down quals. If output column k
3560  * is found to be unsafe to reference, we set the reason for that inside
3561  * safetyInfo->unsafeFlags[k], but we don't reject the subquery overall since
3562  * column k might not be referenced by some/all quals. The unsafeFlags[]
3563  * array will be consulted later by qual_is_pushdown_safe(). It's better to
3564  * do it this way than to make the checks directly in qual_is_pushdown_safe(),
3565  * because when the subquery involves set operations we have to check the
3566  * output expressions in each arm of the set op.
3567  *
3568  * Note: pushing quals into a DISTINCT subquery is theoretically dubious:
3569  * we're effectively assuming that the quals cannot distinguish values that
3570  * the DISTINCT's equality operator sees as equal, yet there are many
3571  * counterexamples to that assumption. However use of such a qual with a
3572  * DISTINCT subquery would be unsafe anyway, since there's no guarantee which
3573  * "equal" value will be chosen as the output value by the DISTINCT operation.
3574  * So we don't worry too much about that. Another objection is that if the
3575  * qual is expensive to evaluate, running it for each original row might cost
3576  * more than we save by eliminating rows before the DISTINCT step. But it
3577  * would be very hard to estimate that at this stage, and in practice pushdown
3578  * seldom seems to make things worse, so we ignore that problem too.
3579  *
3580  * Note: likewise, pushing quals into a subquery with window functions is a
3581  * bit dubious: the quals might remove some rows of a window partition while
3582  * leaving others, causing changes in the window functions' results for the
3583  * surviving rows. We insist that such a qual reference only partitioning
3584  * columns, but again that only protects us if the qual does not distinguish
3585  * values that the partitioning equality operator sees as equal. The risks
3586  * here are perhaps larger than for DISTINCT, since no de-duplication of rows
3587  * occurs and thus there is no theoretical problem with such a qual. But
3588  * we'll do this anyway because the potential performance benefits are very
3589  * large, and we've seen no field complaints about the longstanding comparable
3590  * behavior with DISTINCT.
3591  */
3592 static bool
3593 subquery_is_pushdown_safe(Query *subquery, Query *topquery,
3594  pushdown_safety_info *safetyInfo)
3595 {
3596  SetOperationStmt *topop;
3597 
3598  /* Check point 1 */
3599  if (subquery->limitOffset != NULL || subquery->limitCount != NULL)
3600  return false;
3601 
3602  /* Check point 6 */
3603  if (subquery->groupClause && subquery->groupingSets)
3604  return false;
3605 
3606  /* Check points 3, 4, and 5 */
3607  if (subquery->distinctClause ||
3608  subquery->hasWindowFuncs ||
3609  subquery->hasTargetSRFs)
3610  safetyInfo->unsafeVolatile = true;
3611 
3612  /*
3613  * If we're at a leaf query, check for unsafe expressions in its target
3614  * list, and mark any reasons why they're unsafe in unsafeFlags[].
3615  * (Non-leaf nodes in setop trees have only simple Vars in their tlists,
3616  * so no need to check them.)
3617  */
3618  if (subquery->setOperations == NULL)
3619  check_output_expressions(subquery, safetyInfo);
3620 
3621  /* Are we at top level, or looking at a setop component? */
3622  if (subquery == topquery)
3623  {
3624  /* Top level, so check any component queries */
3625  if (subquery->setOperations != NULL)
3626  if (!recurse_pushdown_safe(subquery->setOperations, topquery,
3627  safetyInfo))
3628  return false;
3629  }
3630  else
3631  {
3632  /* Setop component must not have more components (too weird) */
3633  if (subquery->setOperations != NULL)
3634  return false;
3635  /* Check whether setop component output types match top level */
3636  topop = castNode(SetOperationStmt, topquery->setOperations);
3637  Assert(topop);
3638  compare_tlist_datatypes(subquery->targetList,
3639  topop->colTypes,
3640  safetyInfo);
3641  }
3642  return true;
3643 }
3644 
3645 /*
3646  * Helper routine to recurse through setOperations tree
3647  */
3648 static bool
3649 recurse_pushdown_safe(Node *setOp, Query *topquery,
3650  pushdown_safety_info *safetyInfo)
3651 {
3652  if (IsA(setOp, RangeTblRef))
3653  {
3654  RangeTblRef *rtr = (RangeTblRef *) setOp;
3655  RangeTblEntry *rte = rt_fetch(rtr->rtindex, topquery->rtable);
3656  Query *subquery = rte->subquery;
3657 
3658  Assert(subquery != NULL);
3659  return subquery_is_pushdown_safe(subquery, topquery, safetyInfo);
3660  }
3661  else if (IsA(setOp, SetOperationStmt))
3662  {
3663  SetOperationStmt *op = (SetOperationStmt *) setOp;
3664 
3665  /* EXCEPT is no good (point 2 for subquery_is_pushdown_safe) */
3666  if (op->op == SETOP_EXCEPT)
3667  return false;
3668  /* Else recurse */
3669  if (!recurse_pushdown_safe(op->larg, topquery, safetyInfo))
3670  return false;
3671  if (!recurse_pushdown_safe(op->rarg, topquery, safetyInfo))
3672  return false;
3673  }
3674  else
3675  {
3676  elog(ERROR, "unrecognized node type: %d",
3677  (int) nodeTag(setOp));
3678  }
3679  return true;
3680 }
3681 
3682 /*
3683  * check_output_expressions - check subquery's output expressions for safety
3684  *
3685  * There are several cases in which it's unsafe to push down an upper-level
3686  * qual if it references a particular output column of a subquery. We check
3687  * each output column of the subquery and set flags in unsafeFlags[k] when we
3688  * see that column is unsafe for a pushed-down qual to reference. The
3689  * conditions checked here are:
3690  *
3691  * 1. We must not push down any quals that refer to subselect outputs that
3692  * return sets, else we'd introduce functions-returning-sets into the
3693  * subquery's WHERE/HAVING quals.
3694  *
3695  * 2. We must not push down any quals that refer to subselect outputs that
3696  * contain volatile functions, for fear of introducing strange results due
3697  * to multiple evaluation of a volatile function.
3698  *
3699  * 3. If the subquery uses DISTINCT ON, we must not push down any quals that
3700  * refer to non-DISTINCT output columns, because that could change the set
3701  * of rows returned. (This condition is vacuous for DISTINCT, because then
3702  * there are no non-DISTINCT output columns, so we needn't check. Note that
3703  * subquery_is_pushdown_safe already reported that we can't use volatile
3704  * quals if there's DISTINCT or DISTINCT ON.)
3705  *
3706  * 4. If the subquery has any window functions, we must not push down quals
3707  * that reference any output columns that are not listed in all the subquery's
3708  * window PARTITION BY clauses. We can push down quals that use only
3709  * partitioning columns because they should succeed or fail identically for
3710  * every row of any one window partition, and totally excluding some
3711  * partitions will not change a window function's results for remaining
3712  * partitions. (Again, this also requires nonvolatile quals, but
3713  * subquery_is_pushdown_safe handles that.). Subquery columns marked as
3714  * unsafe for this reason can still have WindowClause run conditions pushed
3715  * down.
3716  */
3717 static void
3718 check_output_expressions(Query *subquery, pushdown_safety_info *safetyInfo)
3719 {
3720  ListCell *lc;
3721 
3722  foreach(lc, subquery->targetList)
3723  {
3724  TargetEntry *tle = (TargetEntry *) lfirst(lc);
3725 
3726  if (tle->resjunk)
3727  continue; /* ignore resjunk columns */
3728 
3729  /* Functions returning sets are unsafe (point 1) */
3730  if (subquery->hasTargetSRFs &&
3731  (safetyInfo->unsafeFlags[tle->resno] &
3732  UNSAFE_HAS_SET_FUNC) == 0 &&
3733  expression_returns_set((Node *) tle->expr))
3734  {
3735  safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_HAS_SET_FUNC;
3736  continue;
3737  }
3738 
3739  /* Volatile functions are unsafe (point 2) */
3740  if ((safetyInfo->unsafeFlags[tle->resno] &
3741  UNSAFE_HAS_VOLATILE_FUNC) == 0 &&
3742  contain_volatile_functions((Node *) tle->expr))
3743  {
3744  safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_HAS_VOLATILE_FUNC;
3745  continue;
3746  }
3747 
3748  /* If subquery uses DISTINCT ON, check point 3 */
3749  if (subquery->hasDistinctOn &&
3750  (safetyInfo->unsafeFlags[tle->resno] &
3751  UNSAFE_NOTIN_DISTINCTON_CLAUSE) == 0 &&
3752  !targetIsInSortList(tle, InvalidOid, subquery->distinctClause))
3753  {
3754  /* non-DISTINCT column, so mark it unsafe */
3755  safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_NOTIN_DISTINCTON_CLAUSE;
3756  continue;
3757  }
3758 
3759  /* If subquery uses window functions, check point 4 */
3760  if (subquery->hasWindowFuncs &&
3761  (safetyInfo->unsafeFlags[tle->resno] &
3762  UNSAFE_NOTIN_DISTINCTON_CLAUSE) == 0 &&
3763  !targetIsInAllPartitionLists(tle, subquery))
3764  {
3765  /* not present in all PARTITION BY clauses, so mark it unsafe */
3766  safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_NOTIN_PARTITIONBY_CLAUSE;
3767  continue;
3768  }
3769  }
3770 }
3771 
3772 /*
3773  * For subqueries using UNION/UNION ALL/INTERSECT/INTERSECT ALL, we can
3774  * push quals into each component query, but the quals can only reference
3775  * subquery columns that suffer no type coercions in the set operation.
3776  * Otherwise there are possible semantic gotchas. So, we check the
3777  * component queries to see if any of them have output types different from
3778  * the top-level setop outputs. We set the UNSAFE_TYPE_MISMATCH bit in
3779  * unsafeFlags[k] if column k has different type in any component.
3780  *
3781  * We don't have to care about typmods here: the only allowed difference
3782  * between set-op input and output typmods is input is a specific typmod
3783  * and output is -1, and that does not require a coercion.
3784  *
3785  * tlist is a subquery tlist.
3786  * colTypes is an OID list of the top-level setop's output column types.
3787  * safetyInfo is the pushdown_safety_info to set unsafeFlags[] for.
3788  */
3789 static void
3790 compare_tlist_datatypes(List *tlist, List *colTypes,
3791  pushdown_safety_info *safetyInfo)
3792 {
3793  ListCell *l;
3794  ListCell *colType = list_head(colTypes);
3795 
3796  foreach(l, tlist)
3797  {
3798  TargetEntry *tle = (TargetEntry *) lfirst(l);
3799 
3800  if (tle->resjunk)
3801  continue; /* ignore resjunk columns */
3802  if (colType == NULL)
3803  elog(ERROR, "wrong number of tlist entries");
3804  if (exprType((Node *) tle->expr) != lfirst_oid(colType))
3805  safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_TYPE_MISMATCH;
3806  colType = lnext(colTypes, colType);
3807  }
3808  if (colType != NULL)
3809  elog(ERROR, "wrong number of tlist entries");
3810 }
3811 
3812 /*
3813  * targetIsInAllPartitionLists
3814  * True if the TargetEntry is listed in the PARTITION BY clause
3815  * of every window defined in the query.
3816  *
3817  * It would be safe to ignore windows not actually used by any window
3818  * function, but it's not easy to get that info at this stage; and it's
3819  * unlikely to be useful to spend any extra cycles getting it, since
3820  * unreferenced window definitions are probably infrequent in practice.
3821  */
3822 static bool
3823 targetIsInAllPartitionLists(TargetEntry *tle, Query *query)
3824 {
3825  ListCell *lc;
3826 
3827  foreach(lc, query->windowClause)
3828  {
3829  WindowClause *wc = (WindowClause *) lfirst(lc);
3830 
3831  if (!targetIsInSortList(tle, InvalidOid, wc->partitionClause))
3832  return false;
3833  }
3834  return true;
3835 }
3836 
3837 /*
3838  * qual_is_pushdown_safe - is a particular rinfo safe to push down?
3839  *
3840  * rinfo is a restriction clause applying to the given subquery (whose RTE
3841  * has index rti in the parent query).
3842  *
3843  * Conditions checked here:
3844  *
3845  * 1. rinfo's clause must not contain any SubPlans (mainly because it's
3846  * unclear that it will work correctly: SubLinks will already have been
3847  * transformed into SubPlans in the qual, but not in the subquery). Note that
3848  * SubLinks that transform to initplans are safe, and will be accepted here
3849  * because what we'll see in the qual is just a Param referencing the initplan
3850  * output.
3851  *
3852  * 2. If unsafeVolatile is set, rinfo's clause must not contain any volatile
3853  * functions.
3854  *
3855  * 3. If unsafeLeaky is set, rinfo's clause must not contain any leaky
3856  * functions that are passed Var nodes, and therefore might reveal values from
3857  * the subquery as side effects.
3858  *
3859  * 4. rinfo's clause must not refer to the whole-row output of the subquery
3860  * (since there is no easy way to name that within the subquery itself).
3861  *
3862  * 5. rinfo's clause must not refer to any subquery output columns that were
3863  * found to be unsafe to reference by subquery_is_pushdown_safe().
3864  */
3865 static pushdown_safe_type
3866 qual_is_pushdown_safe(Query *subquery, Index rti, RestrictInfo *rinfo,
3867  pushdown_safety_info *safetyInfo)
3868 {
3869  pushdown_safe_type safe = PUSHDOWN_SAFE;
3870  Node *qual = (Node *) rinfo->clause;
3871  List *vars;
3872  ListCell *vl;
3873 
3874  /* Refuse subselects (point 1) */
3875  if (contain_subplans(qual))
3876  return PUSHDOWN_UNSAFE;
3877 
3878  /* Refuse volatile quals if we found they'd be unsafe (point 2) */
3879  if (safetyInfo->unsafeVolatile &&
3880  contain_volatile_functions((Node *) rinfo))
3881  return PUSHDOWN_UNSAFE;
3882 
3883  /* Refuse leaky quals if told to (point 3) */
3884  if (safetyInfo->unsafeLeaky &&
3885  contain_leaked_vars(qual))
3886  return PUSHDOWN_UNSAFE;
3887 
3888  /*
3889  * Examine all Vars used in clause. Since it's a restriction clause, all
3890  * such Vars must refer to subselect output columns ... unless this is
3891  * part of a LATERAL subquery, in which case there could be lateral
3892  * references.
3893  *
3894  * By omitting the relevant flags, this also gives us a cheap sanity check
3895  * that no aggregates or window functions appear in the qual. Those would
3896  * be unsafe to push down, but at least for the moment we could never see
3897  * any in a qual anyhow.
3898  */
3899  vars = pull_var_clause(qual, PVC_INCLUDE_PLACEHOLDERS);
3900  foreach(vl, vars)
3901  {
3902  Var *var = (Var *) lfirst(vl);
3903 
3904  /*
3905  * XXX Punt if we find any PlaceHolderVars in the restriction clause.
3906  * It's not clear whether a PHV could safely be pushed down, and even
3907  * less clear whether such a situation could arise in any cases of
3908  * practical interest anyway. So for the moment, just refuse to push
3909  * down.
3910  */
3911  if (!IsA(var, Var))
3912  {
3913  safe = PUSHDOWN_UNSAFE;
3914  break;
3915  }
3916 
3917  /*
3918  * Punt if we find any lateral references. It would be safe to push
3919  * these down, but we'd have to convert them into outer references,
3920  * which subquery_push_qual lacks the infrastructure to do. The case
3921  * arises so seldom that it doesn't seem worth working hard on.
3922  */
3923  if (var->varno != rti)
3924  {
3925  safe = PUSHDOWN_UNSAFE;
3926  break;
3927  }
3928 
3929  /* Subqueries have no system columns */
3930  Assert(var->varattno >= 0);
3931 
3932  /* Check point 4 */
3933  if (var->varattno == 0)
3934  {
3935  safe = PUSHDOWN_UNSAFE;
3936  break;
3937  }
3938 
3939  /* Check point 5 */
3940  if (safetyInfo->unsafeFlags[var->varattno] != 0)
3941  {
3942  if (safetyInfo->unsafeFlags[var->varattno] &
3943  (UNSAFE_HAS_VOLATILE_FUNC | UNSAFE_HAS_SET_FUNC |
3944  UNSAFE_NOTIN_DISTINCTON_CLAUSE | UNSAFE_TYPE_MISMATCH))
3945  {
3946  safe = PUSHDOWN_UNSAFE;
3947  break;
3948  }
3949  else
3950  {
3951  /* UNSAFE_NOTIN_PARTITIONBY_CLAUSE is ok for run conditions */
3952  safe = PUSHDOWN_WINDOWCLAUSE_RUNCOND;
3953  /* don't break, we might find another Var that's unsafe */
3954  }
3955  }
3956  }
3957 
3958  list_free(vars);
3959 
3960  return safe;
3961 }
3962 
3963 /*
3964  * subquery_push_qual - push down a qual that we have determined is safe
3965  */
3966 static void
3967 subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
3968 {
3969  if (subquery->setOperations != NULL)
3970  {
3971  /* Recurse to push it separately to each component query */
3972  recurse_push_qual(subquery->setOperations, subquery,
3973  rte, rti, qual);
3974  }
3975  else
3976  {
3977  /*
3978  * We need to replace Vars in the qual (which must refer to outputs of
3979  * the subquery) with copies of the subquery's targetlist expressions.
3980  * Note that at this point, any uplevel Vars in the qual should have
3981  * been replaced with Params, so they need no work.
3982  *
3983  * This step also ensures that when we are pushing into a setop tree,
3984  * each component query gets its own copy of the qual.
3985  */
3986  qual = ReplaceVarsFromTargetList(qual, rti, 0, rte,
3987  subquery->targetList,
3988  REPLACEVARS_REPORT_ERROR, 0,
3989  &subquery->hasSubLinks);
3990 
3991  /*
3992  * Now attach the qual to the proper place: normally WHERE, but if the
3993  * subquery uses grouping or aggregation, put it in HAVING (since the
3994  * qual really refers to the group-result rows).
3995  */
3996  if (subquery->hasAggs || subquery->groupClause || subquery->groupingSets || subquery->havingQual)
3997  subquery->havingQual = make_and_qual(subquery->havingQual, qual);
3998  else
3999  subquery->jointree->quals =
4000  make_and_qual(subquery->jointree->quals, qual);
4001 
4002  /*
4003  * We need not change the subquery's hasAggs or hasSubLinks flags,
4004  * since we can't be pushing down any aggregates that weren't there
4005  * before, and we don't push down subselects at all.
4006  */
4007  }
4008 }
4009 
4010 /*
4011  * Helper routine to recurse through setOperations tree
4012  */
4013 static void
4014 recurse_push_qual(Node *setOp, Query *topquery,
4015  RangeTblEntry *rte, Index rti, Node *qual)
4016 {
4017  if (IsA(setOp, RangeTblRef))
4018  {
4019  RangeTblRef *rtr = (RangeTblRef *) setOp;
4020  RangeTblEntry *subrte = rt_fetch(rtr->rtindex, topquery->rtable);
4021  Query *subquery = subrte->subquery;
4022 
4023  Assert(subquery != NULL);
4024  subquery_push_qual(subquery, rte, rti, qual);
4025  }
4026  else if (IsA(setOp, SetOperationStmt))
4027  {
4028  SetOperationStmt *op = (SetOperationStmt *) setOp;
4029 
4030  recurse_push_qual(op->larg, topquery, rte, rti, qual);
4031  recurse_push_qual(op->rarg, topquery, rte, rti, qual);
4032  }
4033  else
4034  {
4035  elog(ERROR, "unrecognized node type: %d",
4036  (int) nodeTag(setOp));
4037  }
4038 }
4039 
4040 /*****************************************************************************
4041  * SIMPLIFYING SUBQUERY TARGETLISTS
4042  *****************************************************************************/
4043 
4044 /*
4045  * remove_unused_subquery_outputs
4046  * Remove subquery targetlist items we don't need
4047  *
4048  * It's possible, even likely, that the upper query does not read all the
4049  * output columns of the subquery. We can remove any such outputs that are
4050  * not needed by the subquery itself (e.g., as sort/group columns) and do not
4051  * affect semantics otherwise (e.g., volatile functions can't be removed).
4052  * This is useful not only because we might be able to remove expensive-to-
4053  * compute expressions, but because deletion of output columns might allow
4054  * optimizations such as join removal to occur within the subquery.
4055  *
4056  * extra_used_attrs can be passed as non-NULL to mark any columns (offset by
4057  * FirstLowInvalidHeapAttributeNumber) that we should not remove. This
4058  * parameter is modified by the function, so callers must make a copy if they
4059  * need to use the passed in Bitmapset after calling this function.
4060  *
4061  * To avoid affecting column numbering in the targetlist, we don't physically
4062  * remove unused tlist entries, but rather replace their expressions with NULL
4063  * constants. This is implemented by modifying subquery->targetList.
4064  */
4065 static void
4066 remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel,
4067  Bitmapset *extra_used_attrs)
4068 {
4069  Bitmapset *attrs_used;
4070  ListCell *lc;
4071 
4072  /*
4073  * Just point directly to extra_used_attrs. No need to bms_copy as none of
4074  * the current callers use the Bitmapset after calling this function.
4075  */
4076  attrs_used = extra_used_attrs;
4077 
4078  /*
4079  * Do nothing if subquery has UNION/INTERSECT/EXCEPT: in principle we
4080  * could update all the child SELECTs' tlists, but it seems not worth the
4081  * trouble presently.
4082  */
4083  if (subquery->setOperations)
4084  return;
4085 
4086  /*
4087  * If subquery has regular DISTINCT (not DISTINCT ON), we're wasting our
4088  * time: all its output columns must be used in the distinctClause.
4089  */
4090  if (subquery->distinctClause && !subquery->hasDistinctOn)
4091  return;
4092 
4093  /*
4094  * Collect a bitmap of all the output column numbers used by the upper
4095  * query.
4096  *
4097  * Add all the attributes needed for joins or final output. Note: we must
4098  * look at rel's targetlist, not the attr_needed data, because attr_needed
4099  * isn't computed for inheritance child rels, cf set_append_rel_size().
4100  * (XXX might be worth changing that sometime.)
4101  */
4102  pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
4103 
4104  /* Add all the attributes used by un-pushed-down restriction clauses. */
4105  foreach(lc, rel->baserestrictinfo)
4106  {
4107  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4108 
4109  pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
4110  }
4111 
4112  /*
4113  * If there's a whole-row reference to the subquery, we can't remove
4114  * anything.
4115  */
4116  if (bms_is_member(0 - FirstLowInvalidHeapAttributeNumber, attrs_used))
4117  return;
4118 
4119  /*
4120  * Run through the tlist and zap entries we don't need. It's okay to
4121  * modify the tlist items in-place because set_subquery_pathlist made a
4122  * copy of the subquery.
4123  */
4124  foreach(lc, subquery->targetList)
4125  {
4126  TargetEntry *tle = (TargetEntry *) lfirst(lc);
4127  Node *texpr = (Node *) tle->expr;
4128 
4129  /*
4130  * If it has a sortgroupref number, it's used in some sort/group
4131  * clause so we'd better not remove it. Also, don't remove any
4132  * resjunk columns, since their reason for being has nothing to do
4133  * with anybody reading the subquery's output. (It's likely that
4134  * resjunk columns in a sub-SELECT would always have ressortgroupref
4135  * set, but even if they don't, it seems imprudent to remove them.)
4136  */
4137  if (tle->ressortgroupref || tle->resjunk)
4138  continue;
4139 
4140  /*
4141  * If it's used by the upper query, we can't remove it.
4142  */
4143  if (bms_is_member(tle->resno - FirstLowInvalidHeapAttributeNumber,
4144  attrs_used))
4145  continue;
4146 
4147  /*
4148  * If it contains a set-returning function, we can't remove it since
4149  * that could change the number of rows returned by the subquery.
4150  */
4151  if (subquery->hasTargetSRFs &&
4152  expression_returns_set(texpr))
4153  continue;
4154 
4155  /*
4156  * If it contains volatile functions, we daren't remove it for fear
4157  * that the user is expecting their side-effects to happen.
4158  */
4159  if (contain_volatile_functions(texpr))
4160  continue;
4161 
4162  /*
4163  * OK, we don't need it. Replace the expression with a NULL constant.
4164  * Preserve the exposed type of the expression, in case something
4165  * looks at the rowtype of the subquery's result.
4166  */
4167  tle->expr = (Expr *) makeNullConst(exprType(texpr),
4168  exprTypmod(texpr),
4169  exprCollation(texpr));
4170  }
4171 }
4172 
4173 /*
4174  * create_partial_bitmap_paths
4175  * Build partial bitmap heap path for the relation
4176  */
4177 void
4178 create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel,
4179  Path *bitmapqual)
4180 {
4181  int parallel_workers;
4182  double pages_fetched;
4183 
4184  /* Compute heap pages for bitmap heap scan */
4185  pages_fetched = compute_bitmap_pages(root, rel, bitmapqual, 1.0,
4186  NULL, NULL);
4187 
4188  parallel_workers = compute_parallel_worker(rel, pages_fetched, -1,
4189  max_parallel_workers_per_gather);
4190 
4191  if (parallel_workers <= 0)
4192  return;
4193 
4194  add_partial_path(rel, (Path *) create_bitmap_heap_path(root, rel,
4195  bitmapqual, rel->lateral_relids, 1.0, parallel_workers));
4196 }
4197 
4198 /*
4199  * Compute the number of parallel workers that should be used to scan a
4200  * relation. We compute the parallel workers based on the size of the heap to
4201  * be scanned and the size of the index to be scanned, then choose a minimum
4202  * of those.
4203  *
4204  * "heap_pages" is the number of pages from the table that we expect to scan, or
4205  * -1 if we don't expect to scan any.
4206  *
4207  * "index_pages" is the number of pages from the index that we expect to scan, or
4208  * -1 if we don't expect to scan any.
4209  *
4210  * "max_workers" is caller's limit on the number of workers. This typically
4211  * comes from a GUC.
4212  */
4213 int
4214 compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages,
4215  int max_workers)
4216 {
4217  int parallel_workers = 0;
4218 
4219  /*
4220  * If the user has set the parallel_workers reloption, use that; otherwise
4221  * select a default number of workers.
4222  */
4223  if (rel->rel_parallel_workers != -1)
4224  parallel_workers = rel->rel_parallel_workers;
4225  else
4226  {
4227  /*
4228  * If the number of pages being scanned is insufficient to justify a
4229  * parallel scan, just return zero ... unless it's an inheritance
4230  * child. In that case, we want to generate a parallel path here
4231  * anyway. It might not be worthwhile just for this relation, but
4232  * when combined with all of its inheritance siblings it may well pay
4233  * off.
4234  */
4235  if (rel->reloptkind == RELOPT_BASEREL &&
4236  ((heap_pages >= 0 && heap_pages < min_parallel_table_scan_size) ||
4237  (index_pages >= 0 && index_pages < min_parallel_index_scan_size)))
4238  return 0;
4239 
4240  if (heap_pages >= 0)
4241  {
4242  int heap_parallel_threshold;
4243  int heap_parallel_workers = 1;
4244 
4245  /*
4246  * Select the number of workers based on the log of the size of
4247  * the relation. This probably needs to be a good deal more
4248  * sophisticated, but we need something here for now. Note that
4249  * the upper limit of the min_parallel_table_scan_size GUC is
4250  * chosen to prevent overflow here.
4251  */
4252  heap_parallel_threshold = Max(min_parallel_table_scan_size, 1);
4253  while (heap_pages >= (BlockNumber) (heap_parallel_threshold * 3))
4254  {
4255  heap_parallel_workers++;
4256  heap_parallel_threshold *= 3;
4257  if (heap_parallel_threshold > INT_MAX / 3)
4258  break; /* avoid overflow */
4259  }
4260 
4261  parallel_workers = heap_parallel_workers;
4262  }
4263 
4264  if (index_pages >= 0)
4265  {
4266  int index_parallel_workers = 1;
4267  int index_parallel_threshold;
4268 
4269  /* same calculation as for heap_pages above */
4270  index_parallel_threshold = Max(min_parallel_index_scan_size, 1);
4271  while (index_pages >= (BlockNumber) (index_parallel_threshold * 3))
4272  {
4273  index_parallel_workers++;
4274  index_parallel_threshold *= 3;
4275  if (index_parallel_threshold > INT_MAX / 3)
4276  break; /* avoid overflow */
4277  }
4278 
4279  if (parallel_workers > 0)
4280  parallel_workers = Min(parallel_workers, index_parallel_workers);
4281  else
4282  parallel_workers = index_parallel_workers;
4283  }
4284  }
4285 
4286  /* In no case use more than caller supplied maximum number of workers */
4287  parallel_workers = Min(parallel_workers, max_workers);
4288 
4289  return parallel_workers;
4290 }
4291 
4292 /*
4293  * generate_partitionwise_join_paths
4294  * Create paths representing partitionwise join for given partitioned
4295  * join relation.
4296  *
4297  * This must not be called until after we are done adding paths for all
4298  * child-joins. Otherwise, add_path might delete a path to which some path
4299  * generated here has a reference.
4300  */
4301 void
4302 generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
4303 {
4304  List *live_children = NIL;
4305  int cnt_parts;
4306  int num_parts;
4307  RelOptInfo **part_rels;
4308 
4309  /* Handle only join relations here. */
4310  if (!IS_JOIN_REL(rel))
4311  return;
4312 
4313  /* We've nothing to do if the relation is not partitioned. */
4314  if (!IS_PARTITIONED_REL(rel))
4315  return;
4316 
4317  /* The relation should have consider_partitionwise_join set. */
4318  Assert(rel->consider_partitionwise_join);
4319 
4320  /* Guard against stack overflow due to overly deep partition hierarchy. */
4321  check_stack_depth();
4322 
4323  num_parts = rel->nparts;
4324  part_rels = rel->part_rels;
4325 
4326  /* Collect non-dummy child-joins. */
4327  for (cnt_parts = 0; cnt_parts < num_parts; cnt_parts++)
4328  {
4329  RelOptInfo *child_rel = part_rels[cnt_parts];
4330 
4331  /* If it's been pruned entirely, it's certainly dummy. */
4332  if (child_rel == NULL)
4333  continue;
4334 
4335  /* Make partitionwise join paths for this partitioned child-join. */
4336  generate_partitionwise_join_paths(root, child_rel);
4337 
4338  /* If we failed to make any path for this child, we must give up. */
4339  if (child_rel->pathlist == NIL)
4340  {
4341  /*
4342  * Mark the parent joinrel as unpartitioned so that later
4343  * functions treat it correctly.
4344  */
4345  rel->nparts = 0;
4346  return;
4347  }
4348 
4349  /* Else, identify the cheapest path for it. */
4350  set_cheapest(child_rel);
4351 
4352  /* Dummy children need not be scanned, so ignore those. */
4353  if (IS_DUMMY_REL(child_rel))
4354  continue;
4355 
4356 #ifdef OPTIMIZER_DEBUG
4357  pprint(child_rel);
4358 #endif
4359 
4360  live_children = lappend(live_children, child_rel);
4361  }
4362 
4363  /* If all child-joins are dummy, parent join is also dummy. */
4364  if (!live_children)
4365  {
4366  mark_dummy_rel(rel);
4367  return;
4368  }
4369 
4370  /* Build additional paths for this rel from child-join paths. */
4371  add_paths_to_append_rel(root, rel, live_children);
4372  list_free(live_children);
4373 }
set_base_rel_sizes
static void set_base_rel_sizes(PlannerInfo *root)
Definition: allpaths.c:290
set_subquery_pathlist
static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:2494
find_window_run_conditions
static bool find_window_run_conditions(Query *subquery, RangeTblEntry *rte, Index rti, AttrNumber attno, WindowFunc *wfunc, OpExpr *opexpr, bool wfunc_left, bool *keep_original, Bitmapset **run_cond_attrs)
Definition: allpaths.c:2226
UNSAFE_TYPE_MISMATCH
#define UNSAFE_TYPE_MISMATCH
Definition: allpaths.c:57
get_cheapest_parameterized_child_path
static Path * get_cheapest_parameterized_child_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: allpaths.c:2011
set_namedtuplestore_pathlist
static void set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2951
subquery_push_qual
static void subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:3967
generate_partitionwise_join_paths
void generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:4302
standard_join_search
RelOptInfo * standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
Definition: allpaths.c:3422
set_base_rel_consider_startup
static void set_base_rel_consider_startup(PlannerInfo *root)
Definition: allpaths.c:247
UNSAFE_HAS_VOLATILE_FUNC
#define UNSAFE_HAS_VOLATILE_FUNC
Definition: allpaths.c:53
UNSAFE_NOTIN_DISTINCTON_CLAUSE
#define UNSAFE_NOTIN_DISTINCTON_CLAUSE
Definition: allpaths.c:55
set_rel_pathlist
static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:469
get_singleton_append_subpath
static Path * get_singleton_append_subpath(Path *path)
Definition: allpaths.c:2144
set_tablesample_rel_size
static void set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:826
set_tablesample_rel_pathlist
static void set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:866
set_foreign_pathlist
static void set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:938
set_base_rel_pathlists
static void set_base_rel_pathlists(PlannerInfo *root)
Definition: allpaths.c:333
geqo_threshold
int geqo_threshold
Definition: allpaths.c:80
set_append_rel_pathlist
static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:1244
qual_is_pushdown_safe
static pushdown_safe_type qual_is_pushdown_safe(Query *subquery, Index rti, RestrictInfo *rinfo, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3866
set_result_pathlist
static void set_result_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2978
compute_parallel_worker
int compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages, int max_workers)
Definition: allpaths.c:4214
generate_gather_paths
void generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:3064
set_dummy_rel_pathlist
static void set_dummy_rel_pathlist(RelOptInfo *rel)
Definition: allpaths.c:2178
compare_tlist_datatypes
static void compare_tlist_datatypes(List *tlist, List *colTypes, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3790
set_worktable_pathlist
static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:3005
targetIsInAllPartitionLists
static bool targetIsInAllPartitionLists(TargetEntry *tle, Query *query)
Definition: allpaths.c:3823
create_plain_partial_paths
static void create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:806
subquery_is_pushdown_safe
static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3593
join_search_hook
join_search_hook_type join_search_hook
Definition: allpaths.c:88
enable_geqo
bool enable_geqo
Definition: allpaths.c:79
check_and_push_window_quals
static bool check_and_push_window_quals(Query *subquery, RangeTblEntry *rte, Index rti, Node *clause, Bitmapset **run_cond_attrs)
Definition: allpaths.c:2419
generate_useful_gather_paths
void generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:3201
make_rel_from_joinlist
static RelOptInfo * make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
Definition: allpaths.c:3317
set_function_pathlist
static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2761
recurse_push_qual
static void recurse_push_qual(Node *setOp, Query *topquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:4014
set_plain_rel_pathlist
static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:768
get_useful_pathkeys_for_relation
static List * get_useful_pathkeys_for_relation(PlannerInfo *root, RelOptInfo *rel, bool require_parallel_safe)
Definition: allpaths.c:3133
remove_unused_subquery_outputs
static void remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel, Bitmapset *extra_used_attrs)
Definition: allpaths.c:4066
check_output_expressions
static void check_output_expressions(Query *subquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3718
set_tablefunc_pathlist
static void set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2848
set_foreign_size
static void set_foreign_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:914
set_rel_pathlist_hook
set_rel_pathlist_hook_type set_rel_pathlist_hook
Definition: allpaths.c:85
set_values_pathlist
static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2828
pushdown_safety_info
struct pushdown_safety_info pushdown_safety_info
UNSAFE_HAS_SET_FUNC
#define UNSAFE_HAS_SET_FUNC
Definition: allpaths.c:54
set_cte_pathlist
static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2872
set_rel_consider_parallel
static void set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:589
set_append_rel_size
static void set_append_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:956
create_partial_bitmap_paths
void create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual)
Definition: allpaths.c:4178
set_plain_rel_size
static void set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:572
add_paths_to_append_rel
void add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel, List *live_childrels)
Definition: allpaths.c:1314
set_rel_size
static void set_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:360
generate_orderedappend_paths
static void generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel, List *live_childrels, List *all_child_pathkeys)
Definition: allpaths.c:1726
UNSAFE_NOTIN_PARTITIONBY_CLAUSE
#define UNSAFE_NOTIN_PARTITIONBY_CLAUSE
Definition: allpaths.c:56
make_one_rel
RelOptInfo * make_one_rel(PlannerInfo *root, List *joinlist)
Definition: allpaths.c:171
recurse_pushdown_safe
static bool recurse_pushdown_safe(Node *setOp, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3649
pushdown_safe_type
pushdown_safe_type
Definition: allpaths.c:71
PUSHDOWN_WINDOWCLAUSE_RUNCOND
@ PUSHDOWN_WINDOWCLAUSE_RUNCOND
Definition: allpaths.c:74
PUSHDOWN_UNSAFE
@ PUSHDOWN_UNSAFE
Definition: allpaths.c:72
PUSHDOWN_SAFE
@ PUSHDOWN_SAFE
Definition: allpaths.c:73
accumulate_append_subpath
static void accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths)
Definition: allpaths.c:2099
min_parallel_index_scan_size
int min_parallel_index_scan_size
Definition: allpaths.c:82
min_parallel_table_scan_size
int min_parallel_table_scan_size
Definition: allpaths.c:81
adjust_appendrel_attrs
Node * adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos, AppendRelInfo **appinfos)
Definition: appendinfo.c:200
AttrNumber
int16 AttrNumber
Definition: attnum.h:21
InvalidAttrNumber
#define InvalidAttrNumber
Definition: attnum.h:23
pprint
void pprint(const void *obj)
Definition: print.c:54
bms_equal
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:142
bms_is_subset
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:412
bms_is_member
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
bms_add_member
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
bms_membership
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
bms_overlap
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:582
bms_get_singleton_member
bool bms_get_singleton_member(const Bitmapset *a, int *member)
Definition: bitmapset.c:715
bms_is_empty
#define bms_is_empty(a)
Definition: bitmapset.h:118
BMS_SINGLETON
@ BMS_SINGLETON
Definition: bitmapset.h:72
BMS_MULTIPLE
@ BMS_MULTIPLE
Definition: bitmapset.h:73
BlockNumber
uint32 BlockNumber
Definition: block.h:31
Min
#define Min(x, y)
Definition: c.h:958
Max
#define Max(x, y)
Definition: c.h:952
Assert
#define Assert(condition)
Definition: c.h:812
int16
int16_t int16
Definition: c.h:480
int32
int32_t int32
Definition: c.h:481
Index
unsigned int Index
Definition: c.h:568
OidIsValid
#define OidIsValid(objectId)
Definition: c.h:729
is_pseudo_constant_clause
bool is_pseudo_constant_clause(Node *clause)
Definition: clauses.c:2087
contain_leaked_vars
bool contain_leaked_vars(Node *clause)
Definition: clauses.c:1262
is_parallel_safe
bool is_parallel_safe(PlannerInfo *root, Node *node)
Definition: clauses.c:752
contain_subplans
bool contain_subplans(Node *clause)
Definition: clauses.c:329
contain_volatile_functions
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:537
set_namedtuplestore_size_estimates
void set_namedtuplestore_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6088
max_parallel_workers_per_gather
int max_parallel_workers_per_gather
Definition: costsize.c:143
set_baserel_size_estimates
void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5325
set_function_size_estimates
void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5958
set_cte_size_estimates
void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel, double cte_rows)
Definition: costsize.c:6050
compute_gather_rows
double compute_gather_rows(Path *path)
Definition: costsize.c:6600
set_result_size_estimates
void set_result_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6121
enable_partitionwise_join
bool enable_partitionwise_join
Definition: costsize.c:159
compute_bitmap_pages
double compute_bitmap_pages(PlannerInfo *root, RelOptInfo *baserel, Path *bitmapqual, double loop_count, Cost *cost_p, double *tuples_p)
Definition: costsize.c:6489
set_subquery_size_estimates
void set_subquery_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5878
enable_parallel_append
bool enable_parallel_append
Definition: costsize.c:161
set_foreign_size_estimates
void set_foreign_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6150
clamp_row_est
double clamp_row_est(double nrows)
Definition: costsize.c:213
set_tablefunc_size_estimates
void set_tablefunc_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5996
set_values_size_estimates
void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6018
enable_incremental_sort
bool enable_incremental_sort
Definition: costsize.c:151
ERROR
#define ERROR
Definition: elog.h:39
elog
#define elog(elevel,...)
Definition: elog.h:225
add_child_rel_equivalences
void add_child_rel_equivalences(PlannerInfo *root, AppendRelInfo *appinfo, RelOptInfo *parent_rel, RelOptInfo *child_rel)
Definition: equivclass.c:2690
relation_can_be_sorted_early
bool relation_can_be_sorted_early(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, bool require_parallel_safe)
Definition: equivclass.c:921
OidFunctionCall1
#define OidFunctionCall1(functionId, arg1)
Definition: fmgr.h:679
geqo
RelOptInfo * geqo(PlannerInfo *root, int number_of_rels, List *initial_rels)
Definition: geqo_main.c:72
check_index_predicates
void check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:3953
create_index_paths
void create_index_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:241
i
int i
Definition: isn.c:72
if
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:76
join_search_one_level
void join_search_one_level(PlannerInfo *root, int level)
Definition: joinrels.c:72
mark_dummy_rel
void mark_dummy_rel(RelOptInfo *rel)
Definition: joinrels.c:1384
lappend
List * lappend(List *list, void *datum)
Definition: list.c:339
list_copy_head
List * list_copy_head(const List *oldlist, int len)
Definition: list.c:1593
list_free
void list_free(List *list)
Definition: list.c:1546
list_copy_tail
List * list_copy_tail(const List *oldlist, int nskip)
Definition: list.c:1613
list_concat
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
get_rel_persistence
char get_rel_persistence(Oid relid)
Definition: lsyscache.c:2078
func_parallel
char func_parallel(Oid funcid)
Definition: lsyscache.c:1799
get_func_support
RegProcedure get_func_support(Oid funcid)
Definition: lsyscache.c:1858
get_opfamily_member
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition: lsyscache.c:166
func_strict
bool func_strict(Oid funcid)
Definition: lsyscache.c:1761
get_op_btree_interpretation
List * get_op_btree_interpretation(Oid opno)
Definition: lsyscache.c:601
get_typavgwidth
int32 get_typavgwidth(Oid typid, int32 typmod)
Definition: lsyscache.c:2578
subpath
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:308
makeNullConst
Const * makeNullConst(Oid consttype, int32 consttypmod, Oid constcollid)
Definition: makefuncs.c:339
make_and_qual
Node * make_and_qual(Node *qual1, Node *qual2)
Definition: makefuncs.c:730
pfree
void pfree(void *pointer)
Definition: mcxt.c:1521
palloc0
void * palloc0(Size size)
Definition: mcxt.c:1347
exprType
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
exprTypmod
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:298
exprCollation
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:816
expression_returns_set
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:758
set_opfuncid
void set_opfuncid(OpExpr *opexpr)
Definition: nodeFuncs.c:1861
IsA
#define IsA(nodeptr, _type_)
Definition: nodes.h:158
copyObject
#define copyObject(obj)
Definition: nodes.h:224
nodeTag
#define nodeTag(nodeptr)
Definition: nodes.h:133
makeNode
#define makeNode(_type_)
Definition: nodes.h:155
castNode
#define castNode(_type_, nodeptr)
Definition: nodes.h:176
JOIN_SEMI
@ JOIN_SEMI
Definition: nodes.h:307
JOIN_ANTI
@ JOIN_ANTI
Definition: nodes.h:308
PVC_INCLUDE_PLACEHOLDERS
#define PVC_INCLUDE_PLACEHOLDERS
Definition: optimizer.h:191
targetIsInSortList
bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList)
Definition: parse_clause.c:3633
parse_clause.h
SETOP_EXCEPT
@ SETOP_EXCEPT
Definition: parsenodes.h:2121
RTE_JOIN
@ RTE_JOIN
Definition: parsenodes.h:1019
RTE_CTE
@ RTE_CTE
Definition: parsenodes.h:1023
RTE_NAMEDTUPLESTORE
@ RTE_NAMEDTUPLESTORE
Definition: parsenodes.h:1024
RTE_VALUES
@ RTE_VALUES
Definition: parsenodes.h:1022
RTE_SUBQUERY
@ RTE_SUBQUERY
Definition: parsenodes.h:1018
RTE_RESULT
@ RTE_RESULT
Definition: parsenodes.h:1025
RTE_FUNCTION
@ RTE_FUNCTION
Definition: parsenodes.h:1020
RTE_TABLEFUNC
@ RTE_TABLEFUNC
Definition: parsenodes.h:1021
RTE_GROUP
@ RTE_GROUP
Definition: parsenodes.h:1028
RTE_RELATION
@ RTE_RELATION
Definition: parsenodes.h:1017
rt_fetch
#define rt_fetch(rangetable_index, rangetable)
Definition: parsetree.h:31
partitions_are_ordered
bool partitions_are_ordered(PartitionBoundInfo boundinfo, Bitmapset *live_parts)
Definition: partbounds.c:2852
build_expression_pathkey
List * build_expression_pathkey(PlannerInfo *root, Expr *expr, Oid opno, Relids rel, bool create_it)
Definition: pathkeys.c:1000
get_cheapest_path_for_pathkeys
Path * get_cheapest_path_for_pathkeys(List *paths, List *pathkeys, Relids required_outer, CostSelector cost_criterion, bool require_parallel_safe)
Definition: pathkeys.c:620
pathkeys_count_contained_in
bool pathkeys_count_contained_in(List *keys1, List *keys2, int *n_common)
Definition: pathkeys.c:558
has_useful_pathkeys
bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel)
Definition: pathkeys.c:2315
get_cheapest_parallel_safe_total_inner
Path * get_cheapest_parallel_safe_total_inner(List *paths)
Definition: pathkeys.c:699
convert_subquery_pathkeys
List * convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel, List *subquery_pathkeys, List *subquery_tlist)
Definition: pathkeys.c:1054
get_cheapest_fractional_path_for_pathkeys
Path * get_cheapest_fractional_path_for_pathkeys(List *paths, List *pathkeys, Relids required_outer, double fraction)
Definition: pathkeys.c:666
pathkeys_contained_in
bool pathkeys_contained_in(List *keys1, List *keys2)
Definition: pathkeys.c:343
compare_pathkeys
PathKeysComparison compare_pathkeys(List *keys1, List *keys2)
Definition: pathkeys.c:304
build_partition_pathkeys
List * build_partition_pathkeys(PlannerInfo *root, RelOptInfo *partrel, ScanDirection scandir, bool *partialkeys)
Definition: pathkeys.c:919
create_append_path
AppendPath * create_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *partial_subpaths, List *pathkeys, Relids required_outer, int parallel_workers, bool parallel_aware, double rows)
Definition: pathnode.c:1300
create_sort_path
SortPath * create_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, double limit_tuples)
Definition: pathnode.c:3082
create_gather_merge_path
GatherMergePath * create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, List *pathkeys, Relids required_outer, double *rows)
Definition: pathnode.c:1962
create_tablefuncscan_path
Path * create_tablefuncscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2144
create_namedtuplestorescan_path
Path * create_namedtuplestorescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2222
create_gather_path
GatherPath * create_gather_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, Relids required_outer, double *rows)
Definition: pathnode.c:2044
create_resultscan_path
Path * create_resultscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2248
create_samplescan_path
Path * create_samplescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1008
create_merge_append_path
MergeAppendPath * create_merge_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *pathkeys, Relids required_outer)
Definition: pathnode.c:1471
set_cheapest
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:269
reparameterize_path
Path * reparameterize_path(PlannerInfo *root, Path *path, Relids required_outer, double loop_count)
Definition: pathnode.c:4046
create_subqueryscan_path
SubqueryScanPath * create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, bool trivial_pathtarget, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2088
add_partial_path
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:795
create_material_path
MaterialPath * create_material_path(RelOptInfo *rel, Path *subpath)
Definition: pathnode.c:1634
create_functionscan_path
Path * create_functionscan_path(PlannerInfo *root, RelOptInfo *rel, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2118
create_incremental_sort_path
IncrementalSortPath * create_incremental_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, int presorted_keys, double limit_tuples)
Definition: pathnode.c:3032
create_worktablescan_path
Path * create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2274
add_path
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:461
create_valuesscan_path
Path * create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2170
compare_path_costs
int compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
Definition: pathnode.c:69
create_seqscan_path
Path * create_seqscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer, int parallel_workers)
Definition: pathnode.c:983
create_ctescan_path
Path * create_ctescan_path(PlannerInfo *root, RelOptInfo *rel, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2196
create_bitmap_heap_path
BitmapHeapPath * create_bitmap_heap_path(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual, Relids required_outer, double loop_count, int parallel_degree)
Definition: pathnode.c:1098
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:839
IS_DUMMY_REL
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1958
IS_JOIN_REL
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:844
TOTAL_COST
@ TOTAL_COST
Definition: pathnodes.h:38
STARTUP_COST
@ STARTUP_COST
Definition: pathnodes.h:38
IS_PARTITIONED_REL
#define IS_PARTITIONED_REL(rel)
Definition: pathnodes.h:1062
PATH_REQ_OUTER
#define PATH_REQ_OUTER(path)
Definition: pathnodes.h:1681
Relids
Bitmapset * Relids
Definition: pathnodes.h:30
UPPERREL_FINAL
@ UPPERREL_FINAL
Definition: pathnodes.h:79
RELOPT_BASEREL
@ RELOPT_BASEREL
Definition: pathnodes.h:827
RELOPT_OTHER_MEMBER_REL
@ RELOPT_OTHER_MEMBER_REL
Definition: pathnodes.h:829
join_search_hook_type
RelOptInfo *(* join_search_hook_type)(PlannerInfo *root, int levels_needed, List *initial_rels)
Definition: paths.h:46
set_rel_pathlist_hook_type
void(* set_rel_pathlist_hook_type)(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: paths.h:30
PATHKEYS_EQUAL
@ PATHKEYS_EQUAL
Definition: paths.h:204
arg
void * arg
Definition: pg_backup_utils.c:29
pg_bitutils.h
pg_leftmost_one_pos32
static int pg_leftmost_one_pos32(uint32 word)
Definition: pg_bitutils.h:41
pg_class.h
lfirst
#define lfirst(lc)
Definition: pg_list.h:172
list_length
static int list_length(const List *l)
Definition: pg_list.h:152
NIL
#define NIL
Definition: pg_list.h:68
forboth
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:518
foreach_current_index
#define foreach_current_index(var_or_cell)
Definition: pg_list.h:403
list_make1
#define list_make1(x1)
Definition: pg_list.h:212
list_head
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
for_each_from
#define for_each_from(cell, lst, N)
Definition: pg_list.h:414
linitial
#define linitial(l)
Definition: pg_list.h:178
lsecond
#define lsecond(l)
Definition: pg_list.h:183
list_nth
static void * list_nth(const List *list, int n)
Definition: pg_list.h:299
list_nth_node
#define list_nth_node(type, list, n)
Definition: pg_list.h:327
lnext
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
lfirst_oid
#define lfirst_oid(lc)
Definition: pg_list.h:174
list_nth_int
static int list_nth_int(const List *list, int n)
Definition: pg_list.h:310
pg_operator.h
pg_proc.h
relation_excluded_by_constraints
bool relation_excluded_by_constraints(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: plancat.c:1583
subquery_planner
PlannerInfo * subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, bool hasRecursion, double tuple_fraction, SetOperationStmt *setops)
Definition: planner.c:638
limit_needed
bool limit_needed(Query *parse)
Definition: planner.c:2685
MONOTONICFUNC_NONE
@ MONOTONICFUNC_NONE
Definition: plannodes.h:1588
MONOTONICFUNC_DECREASING
@ MONOTONICFUNC_DECREASING
Definition: plannodes.h:1590
MONOTONICFUNC_INCREASING
@ MONOTONICFUNC_INCREASING
Definition: plannodes.h:1589
MONOTONICFUNC_BOTH
@ MONOTONICFUNC_BOTH
Definition: plannodes.h:1591
check_stack_depth
void check_stack_depth(void)
Definition: postgres.c:3572
PointerGetDatum
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:322
DatumGetPointer
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:312
InvalidOid
#define InvalidOid
Definition: postgres_ext.h:36
Oid
unsigned int Oid
Definition: postgres_ext.h:31
root
tree ctl root
Definition: radixtree.h:1888
parse
static struct subre * parse(struct vars *v, int stopper, int type, struct state *init, struct state *final)
Definition: regcomp.c:717
find_base_rel
RelOptInfo * find_base_rel(PlannerInfo *root, int relid)
Definition: relnode.c:414
fetch_upper_rel
RelOptInfo * fetch_upper_rel(PlannerInfo *root, UpperRelationKind kind, Relids relids)
Definition: relnode.c:1458
ReplaceVarsFromTargetList
Node * ReplaceVarsFromTargetList(Node *node, int target_varno, int sublevels_up, RangeTblEntry *target_rte, List *targetlist, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno, bool *outer_hasSubLinks)
Definition: rewriteManip.c:1759
REPLACEVARS_REPORT_ERROR
@ REPLACEVARS_REPORT_ERROR
Definition: rewriteManip.h:38
BackwardScanDirection
@ BackwardScanDirection
Definition: sdir.h:26
ForwardScanDirection
@ ForwardScanDirection
Definition: sdir.h:28
BTGreaterStrategyNumber
#define BTGreaterStrategyNumber
Definition: stratnum.h:33
BTLessStrategyNumber
#define BTLessStrategyNumber
Definition: stratnum.h:29
BTEqualStrategyNumber
#define BTEqualStrategyNumber
Definition: stratnum.h:31
BTLessEqualStrategyNumber
#define BTLessEqualStrategyNumber
Definition: stratnum.h:30
BTGreaterEqualStrategyNumber
#define BTGreaterEqualStrategyNumber
Definition: stratnum.h:32
AppendPath::first_partial_path
int first_partial_path
Definition: pathnodes.h:1946
AppendPath::subpaths
List * subpaths
Definition: pathnodes.h:1944
AppendRelInfo::child_relid
Index child_relid
Definition: pathnodes.h:2982
AppendRelInfo::parent_relid
Index parent_relid
Definition: pathnodes.h:2981
FromExpr::quals
Node * quals
Definition: primnodes.h:2309
List
Definition: pg_list.h:54
Node
Definition: nodes.h:129
OpExpr::opno
Oid opno
Definition: primnodes.h:818
OpExpr::args
List * args
Definition: primnodes.h:836
PathTarget::exprs
List * exprs
Definition: pathnodes.h:1544
Path::pathkeys
List * pathkeys
Definition: pathnodes.h:1677
Path::rows
Cardinality rows
Definition: pathnodes.h:1671
Path::parallel_workers
int parallel_workers
Definition: pathnodes.h:1668
Path::total_cost
Cost total_cost
Definition: pathnodes.h:1674
Path::parallel_aware
bool parallel_aware
Definition: pathnodes.h:1664
Plan::plan_rows
Cardinality plan_rows
Definition: plannodes.h:135
Plan::targetlist
List * targetlist
Definition: plannodes.h:153
PlannerInfo::cte_plan_ids
List * cte_plan_ids
Definition: pathnodes.h:305
PlannerInfo::non_recursive_path
struct Path * non_recursive_path
Definition: pathnodes.h:538
PlannerInfo::parse
Query * parse
Definition: pathnodes.h:202
Query::limitCount
Node * limitCount
Definition: parsenodes.h:216
Query::jointree
FromExpr * jointree
Definition: parsenodes.h:177
Query::setOperations
Node * setOperations
Definition: parsenodes.h:221
Query::cteList
List * cteList
Definition: parsenodes.h:168
Query::groupClause
List * groupClause
Definition: parsenodes.h:202
Query::havingQual
Node * havingQual
Definition: parsenodes.h:207
Query::rtable
List * rtable
Definition: parsenodes.h:170
Query::limitOffset
Node * limitOffset
Definition: parsenodes.h:215
Query::windowClause
List * windowClause
Definition: parsenodes.h:209
Query::targetList
List * targetList
Definition: parsenodes.h:193
Query::groupingSets
List * groupingSets
Definition: parsenodes.h:205
Query::distinctClause
List * distinctClause
Definition: parsenodes.h:211
RangeTblEntry::ctename
char * ctename
Definition: parsenodes.h:1196
RangeTblEntry::ctelevelsup
Index ctelevelsup
Definition: parsenodes.h:1198
RangeTblEntry::funcordinality
bool funcordinality
Definition: parsenodes.h:1179
RangeTblEntry::tablesample
struct TableSampleClause * tablesample
Definition: parsenodes.h:1098
RangeTblEntry::subquery
Query * subquery
Definition: parsenodes.h:1104
RangeTblEntry::values_lists
List * values_lists
Definition: parsenodes.h:1190
RangeTblEntry::functions
List * functions
Definition: parsenodes.h:1177
RangeTblEntry::rtekind
RTEKind rtekind
Definition: parsenodes.h:1047
RelOptInfo::baserestrictinfo
List * baserestrictinfo
Definition: pathnodes.h:985
RelOptInfo::consider_param_startup
bool consider_param_startup
Definition: pathnodes.h:885
RelOptInfo::subplan_params
List * subplan_params
Definition: pathnodes.h:954
RelOptInfo::joininfo
List * joininfo
Definition: pathnodes.h:991
RelOptInfo::relids
Relids relids
Definition: pathnodes.h:871
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition: pathnodes.h:893
RelOptInfo::relid
Index relid
Definition: pathnodes.h:918
RelOptInfo::tuples
Cardinality tuples
Definition: pathnodes.h:949
RelOptInfo::consider_parallel
bool consider_parallel
Definition: pathnodes.h:887
RelOptInfo::pages
BlockNumber pages
Definition: pathnodes.h:948
RelOptInfo::lateral_relids
Relids lateral_relids
Definition: pathnodes.h:913
RelOptInfo::pathlist
List * pathlist
Definition: pathnodes.h:898
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition: pathnodes.h:865
RelOptInfo::cheapest_startup_path
struct Path * cheapest_startup_path
Definition: pathnodes.h:901
RelOptInfo::cheapest_total_path
struct Path * cheapest_total_path
Definition: pathnodes.h:902
RelOptInfo::has_eclass_joins
bool has_eclass_joins
Definition: pathnodes.h:993
RelOptInfo::consider_startup
bool consider_startup
Definition: pathnodes.h:883
RelOptInfo::live_parts
Bitmapset * live_parts
Definition: pathnodes.h:1039
RelOptInfo::rel_parallel_workers
int rel_parallel_workers
Definition: pathnodes.h:956
RelOptInfo::consider_partitionwise_join
bool consider_partitionwise_join
Definition: pathnodes.h:999
RelOptInfo::partial_pathlist
List * partial_pathlist
Definition: pathnodes.h:900
RelOptInfo::subroot
PlannerInfo * subroot
Definition: pathnodes.h:953
RelOptInfo::max_attr
AttrNumber max_attr
Definition: pathnodes.h:926
RelOptInfo::nulling_relids
Relids nulling_relids
Definition: pathnodes.h:938
RelOptInfo::rows
Cardinality rows
Definition: pathnodes.h:877
RelOptInfo::min_attr
AttrNumber min_attr
Definition: pathnodes.h:924
RelOptInfo::rtekind
RTEKind rtekind
Definition: pathnodes.h:922
RestrictInfo::clause
Expr * clause
Definition: pathnodes.h:2576
SetOperationStmt::op
SetOperation op
Definition: parsenodes.h:2198
SpecialJoinInfo::jointype
JoinType jointype
Definition: pathnodes.h:2910
SpecialJoinInfo::syn_righthand
Relids syn_righthand
Definition: pathnodes.h:2909
SupportRequestWFuncMonotonic::window_clause
struct WindowClause * window_clause
Definition: supportnodes.h:296
TargetEntry::expr
Expr * expr
Definition: primnodes.h:2190
TargetEntry::resno
AttrNumber resno
Definition: primnodes.h:2192
TargetEntry::ressortgroupref
Index ressortgroupref
Definition: primnodes.h:2196
TsmRoutine::repeatable_across_scans
bool repeatable_across_scans
Definition: tsmapi.h:65
TsmRoutine::SampleScanGetSampleSize
SampleScanGetSampleSize_function SampleScanGetSampleSize
Definition: tsmapi.h:68
Var
Definition: primnodes.h:248
Var::varattno
AttrNumber varattno
Definition: primnodes.h:260
Var::varno
int varno
Definition: primnodes.h:255
Var::varlevelsup
Index varlevelsup
Definition: primnodes.h:280
WindowClause::partitionClause
List * partitionClause
Definition: parsenodes.h:1543
WindowFunc::winref
Index winref
Definition: primnodes.h:581
WindowFunc::winfnoid
Oid winfnoid
Definition: primnodes.h:567
pushdown_safety_info
Definition: allpaths.c:61
pushdown_safety_info::unsafeFlags
unsigned char * unsafeFlags
Definition: allpaths.c:62
pushdown_safety_info::unsafeVolatile
bool unsafeVolatile
Definition: allpaths.c:65
pushdown_safety_info::unsafeLeaky
bool unsafeLeaky
Definition: allpaths.c:66
vars
Definition: regcomp.c:282
FirstLowInvalidHeapAttributeNumber
#define FirstLowInvalidHeapAttributeNumber
Definition: sysattr.h:27
GetTsmRoutine
TsmRoutine * GetTsmRoutine(Oid tsmhandler)
Definition: tablesample.c:27
create_tidscan_paths
bool create_tidscan_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: tidpath.c:498
make_tlist_from_pathtarget
List * make_tlist_from_pathtarget(PathTarget *target)
Definition: tlist.c:624
pull_var_clause
List * pull_var_clause(Node *node, int flags)
Definition: var.c:609
pull_varattnos
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition: var.c:295