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pathnode.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pathnode.c
4  * Routines to manipulate pathlists and create path nodes
5  *
6  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/optimizer/util/pathnode.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "postgres.h"
16 
17 #include <math.h>
18 
19 #include "foreign/fdwapi.h"
20 #include "miscadmin.h"
21 #include "nodes/extensible.h"
22 #include "nodes/nodeFuncs.h"
23 #include "optimizer/appendinfo.h"
24 #include "optimizer/clauses.h"
25 #include "optimizer/cost.h"
26 #include "optimizer/optimizer.h"
27 #include "optimizer/pathnode.h"
28 #include "optimizer/paths.h"
29 #include "optimizer/planmain.h"
30 #include "optimizer/prep.h"
31 #include "optimizer/restrictinfo.h"
32 #include "optimizer/tlist.h"
33 #include "parser/parsetree.h"
34 #include "utils/lsyscache.h"
35 #include "utils/memutils.h"
36 #include "utils/selfuncs.h"
37 
38 typedef enum
39 {
40  COSTS_EQUAL, /* path costs are fuzzily equal */
41  COSTS_BETTER1, /* first path is cheaper than second */
42  COSTS_BETTER2, /* second path is cheaper than first */
43  COSTS_DIFFERENT /* neither path dominates the other on cost */
45 
46 /*
47  * STD_FUZZ_FACTOR is the normal fuzz factor for compare_path_costs_fuzzily.
48  * XXX is it worth making this user-controllable? It provides a tradeoff
49  * between planner runtime and the accuracy of path cost comparisons.
50  */
51 #define STD_FUZZ_FACTOR 1.01
52 
53 static List *translate_sub_tlist(List *tlist, int relid);
54 static int append_total_cost_compare(const ListCell *a, const ListCell *b);
55 static int append_startup_cost_compare(const ListCell *a, const ListCell *b);
57  List *pathlist,
58  RelOptInfo *child_rel);
59 
60 
61 /*****************************************************************************
62  * MISC. PATH UTILITIES
63  *****************************************************************************/
64 
65 /*
66  * compare_path_costs
67  * Return -1, 0, or +1 according as path1 is cheaper, the same cost,
68  * or more expensive than path2 for the specified criterion.
69  */
70 int
71 compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
72 {
73  if (criterion == STARTUP_COST)
74  {
75  if (path1->startup_cost < path2->startup_cost)
76  return -1;
77  if (path1->startup_cost > path2->startup_cost)
78  return +1;
79 
80  /*
81  * If paths have the same startup cost (not at all unlikely), order
82  * them by total cost.
83  */
84  if (path1->total_cost < path2->total_cost)
85  return -1;
86  if (path1->total_cost > path2->total_cost)
87  return +1;
88  }
89  else
90  {
91  if (path1->total_cost < path2->total_cost)
92  return -1;
93  if (path1->total_cost > path2->total_cost)
94  return +1;
95 
96  /*
97  * If paths have the same total cost, order them by startup cost.
98  */
99  if (path1->startup_cost < path2->startup_cost)
100  return -1;
101  if (path1->startup_cost > path2->startup_cost)
102  return +1;
103  }
104  return 0;
105 }
106 
107 /*
108  * compare_path_fractional_costs
109  * Return -1, 0, or +1 according as path1 is cheaper, the same cost,
110  * or more expensive than path2 for fetching the specified fraction
111  * of the total tuples.
112  *
113  * If fraction is <= 0 or > 1, we interpret it as 1, ie, we select the
114  * path with the cheaper total_cost.
115  */
116 int
118  double fraction)
119 {
120  Cost cost1,
121  cost2;
122 
123  if (fraction <= 0.0 || fraction >= 1.0)
124  return compare_path_costs(path1, path2, TOTAL_COST);
125  cost1 = path1->startup_cost +
126  fraction * (path1->total_cost - path1->startup_cost);
127  cost2 = path2->startup_cost +
128  fraction * (path2->total_cost - path2->startup_cost);
129  if (cost1 < cost2)
130  return -1;
131  if (cost1 > cost2)
132  return +1;
133  return 0;
134 }
135 
136 /*
137  * compare_path_costs_fuzzily
138  * Compare the costs of two paths to see if either can be said to
139  * dominate the other.
140  *
141  * We use fuzzy comparisons so that add_path() can avoid keeping both of
142  * a pair of paths that really have insignificantly different cost.
143  *
144  * The fuzz_factor argument must be 1.0 plus delta, where delta is the
145  * fraction of the smaller cost that is considered to be a significant
146  * difference. For example, fuzz_factor = 1.01 makes the fuzziness limit
147  * be 1% of the smaller cost.
148  *
149  * The two paths are said to have "equal" costs if both startup and total
150  * costs are fuzzily the same. Path1 is said to be better than path2 if
151  * it has fuzzily better startup cost and fuzzily no worse total cost,
152  * or if it has fuzzily better total cost and fuzzily no worse startup cost.
153  * Path2 is better than path1 if the reverse holds. Finally, if one path
154  * is fuzzily better than the other on startup cost and fuzzily worse on
155  * total cost, we just say that their costs are "different", since neither
156  * dominates the other across the whole performance spectrum.
157  *
158  * This function also enforces a policy rule that paths for which the relevant
159  * one of parent->consider_startup and parent->consider_param_startup is false
160  * cannot survive comparisons solely on the grounds of good startup cost, so
161  * we never return COSTS_DIFFERENT when that is true for the total-cost loser.
162  * (But if total costs are fuzzily equal, we compare startup costs anyway,
163  * in hopes of eliminating one path or the other.)
164  */
165 static PathCostComparison
166 compare_path_costs_fuzzily(Path *path1, Path *path2, double fuzz_factor)
167 {
168 #define CONSIDER_PATH_STARTUP_COST(p) \
169  ((p)->param_info == NULL ? (p)->parent->consider_startup : (p)->parent->consider_param_startup)
170 
171  /*
172  * Check total cost first since it's more likely to be different; many
173  * paths have zero startup cost.
174  */
175  if (path1->total_cost > path2->total_cost * fuzz_factor)
176  {
177  /* path1 fuzzily worse on total cost */
178  if (CONSIDER_PATH_STARTUP_COST(path1) &&
179  path2->startup_cost > path1->startup_cost * fuzz_factor)
180  {
181  /* ... but path2 fuzzily worse on startup, so DIFFERENT */
182  return COSTS_DIFFERENT;
183  }
184  /* else path2 dominates */
185  return COSTS_BETTER2;
186  }
187  if (path2->total_cost > path1->total_cost * fuzz_factor)
188  {
189  /* path2 fuzzily worse on total cost */
190  if (CONSIDER_PATH_STARTUP_COST(path2) &&
191  path1->startup_cost > path2->startup_cost * fuzz_factor)
192  {
193  /* ... but path1 fuzzily worse on startup, so DIFFERENT */
194  return COSTS_DIFFERENT;
195  }
196  /* else path1 dominates */
197  return COSTS_BETTER1;
198  }
199  /* fuzzily the same on total cost ... */
200  if (path1->startup_cost > path2->startup_cost * fuzz_factor)
201  {
202  /* ... but path1 fuzzily worse on startup, so path2 wins */
203  return COSTS_BETTER2;
204  }
205  if (path2->startup_cost > path1->startup_cost * fuzz_factor)
206  {
207  /* ... but path2 fuzzily worse on startup, so path1 wins */
208  return COSTS_BETTER1;
209  }
210  /* fuzzily the same on both costs */
211  return COSTS_EQUAL;
212 
213 #undef CONSIDER_PATH_STARTUP_COST
214 }
215 
216 /*
217  * set_cheapest
218  * Find the minimum-cost paths from among a relation's paths,
219  * and save them in the rel's cheapest-path fields.
220  *
221  * cheapest_total_path is normally the cheapest-total-cost unparameterized
222  * path; but if there are no unparameterized paths, we assign it to be the
223  * best (cheapest least-parameterized) parameterized path. However, only
224  * unparameterized paths are considered candidates for cheapest_startup_path,
225  * so that will be NULL if there are no unparameterized paths.
226  *
227  * The cheapest_parameterized_paths list collects all parameterized paths
228  * that have survived the add_path() tournament for this relation. (Since
229  * add_path ignores pathkeys for a parameterized path, these will be paths
230  * that have best cost or best row count for their parameterization. We
231  * may also have both a parallel-safe and a non-parallel-safe path in some
232  * cases for the same parameterization in some cases, but this should be
233  * relatively rare since, most typically, all paths for the same relation
234  * will be parallel-safe or none of them will.)
235  *
236  * cheapest_parameterized_paths always includes the cheapest-total
237  * unparameterized path, too, if there is one; the users of that list find
238  * it more convenient if that's included.
239  *
240  * This is normally called only after we've finished constructing the path
241  * list for the rel node.
242  */
243 void
245 {
246  Path *cheapest_startup_path;
247  Path *cheapest_total_path;
248  Path *best_param_path;
249  List *parameterized_paths;
250  ListCell *p;
251 
252  Assert(IsA(parent_rel, RelOptInfo));
253 
254  if (parent_rel->pathlist == NIL)
255  elog(ERROR, "could not devise a query plan for the given query");
256 
257  cheapest_startup_path = cheapest_total_path = best_param_path = NULL;
258  parameterized_paths = NIL;
259 
260  foreach(p, parent_rel->pathlist)
261  {
262  Path *path = (Path *) lfirst(p);
263  int cmp;
264 
265  if (path->param_info)
266  {
267  /* Parameterized path, so add it to parameterized_paths */
268  parameterized_paths = lappend(parameterized_paths, path);
269 
270  /*
271  * If we have an unparameterized cheapest-total, we no longer care
272  * about finding the best parameterized path, so move on.
273  */
274  if (cheapest_total_path)
275  continue;
276 
277  /*
278  * Otherwise, track the best parameterized path, which is the one
279  * with least total cost among those of the minimum
280  * parameterization.
281  */
282  if (best_param_path == NULL)
283  best_param_path = path;
284  else
285  {
286  switch (bms_subset_compare(PATH_REQ_OUTER(path),
287  PATH_REQ_OUTER(best_param_path)))
288  {
289  case BMS_EQUAL:
290  /* keep the cheaper one */
291  if (compare_path_costs(path, best_param_path,
292  TOTAL_COST) < 0)
293  best_param_path = path;
294  break;
295  case BMS_SUBSET1:
296  /* new path is less-parameterized */
297  best_param_path = path;
298  break;
299  case BMS_SUBSET2:
300  /* old path is less-parameterized, keep it */
301  break;
302  case BMS_DIFFERENT:
303 
304  /*
305  * This means that neither path has the least possible
306  * parameterization for the rel. We'll sit on the old
307  * path until something better comes along.
308  */
309  break;
310  }
311  }
312  }
313  else
314  {
315  /* Unparameterized path, so consider it for cheapest slots */
316  if (cheapest_total_path == NULL)
317  {
318  cheapest_startup_path = cheapest_total_path = path;
319  continue;
320  }
321 
322  /*
323  * If we find two paths of identical costs, try to keep the
324  * better-sorted one. The paths might have unrelated sort
325  * orderings, in which case we can only guess which might be
326  * better to keep, but if one is superior then we definitely
327  * should keep that one.
328  */
329  cmp = compare_path_costs(cheapest_startup_path, path, STARTUP_COST);
330  if (cmp > 0 ||
331  (cmp == 0 &&
332  compare_pathkeys(cheapest_startup_path->pathkeys,
333  path->pathkeys) == PATHKEYS_BETTER2))
334  cheapest_startup_path = path;
335 
336  cmp = compare_path_costs(cheapest_total_path, path, TOTAL_COST);
337  if (cmp > 0 ||
338  (cmp == 0 &&
339  compare_pathkeys(cheapest_total_path->pathkeys,
340  path->pathkeys) == PATHKEYS_BETTER2))
341  cheapest_total_path = path;
342  }
343  }
344 
345  /* Add cheapest unparameterized path, if any, to parameterized_paths */
346  if (cheapest_total_path)
347  parameterized_paths = lcons(cheapest_total_path, parameterized_paths);
348 
349  /*
350  * If there is no unparameterized path, use the best parameterized path as
351  * cheapest_total_path (but not as cheapest_startup_path).
352  */
353  if (cheapest_total_path == NULL)
354  cheapest_total_path = best_param_path;
355  Assert(cheapest_total_path != NULL);
356 
357  parent_rel->cheapest_startup_path = cheapest_startup_path;
358  parent_rel->cheapest_total_path = cheapest_total_path;
359  parent_rel->cheapest_unique_path = NULL; /* computed only if needed */
360  parent_rel->cheapest_parameterized_paths = parameterized_paths;
361 }
362 
363 /*
364  * add_path
365  * Consider a potential implementation path for the specified parent rel,
366  * and add it to the rel's pathlist if it is worthy of consideration.
367  * A path is worthy if it has a better sort order (better pathkeys) or
368  * cheaper cost (on either dimension), or generates fewer rows, than any
369  * existing path that has the same or superset parameterization rels.
370  * We also consider parallel-safe paths more worthy than others.
371  *
372  * We also remove from the rel's pathlist any old paths that are dominated
373  * by new_path --- that is, new_path is cheaper, at least as well ordered,
374  * generates no more rows, requires no outer rels not required by the old
375  * path, and is no less parallel-safe.
376  *
377  * In most cases, a path with a superset parameterization will generate
378  * fewer rows (since it has more join clauses to apply), so that those two
379  * figures of merit move in opposite directions; this means that a path of
380  * one parameterization can seldom dominate a path of another. But such
381  * cases do arise, so we make the full set of checks anyway.
382  *
383  * There are two policy decisions embedded in this function, along with
384  * its sibling add_path_precheck. First, we treat all parameterized paths
385  * as having NIL pathkeys, so that they cannot win comparisons on the
386  * basis of sort order. This is to reduce the number of parameterized
387  * paths that are kept; see discussion in src/backend/optimizer/README.
388  *
389  * Second, we only consider cheap startup cost to be interesting if
390  * parent_rel->consider_startup is true for an unparameterized path, or
391  * parent_rel->consider_param_startup is true for a parameterized one.
392  * Again, this allows discarding useless paths sooner.
393  *
394  * The pathlist is kept sorted by total_cost, with cheaper paths
395  * at the front. Within this routine, that's simply a speed hack:
396  * doing it that way makes it more likely that we will reject an inferior
397  * path after a few comparisons, rather than many comparisons.
398  * However, add_path_precheck relies on this ordering to exit early
399  * when possible.
400  *
401  * NOTE: discarded Path objects are immediately pfree'd to reduce planner
402  * memory consumption. We dare not try to free the substructure of a Path,
403  * since much of it may be shared with other Paths or the query tree itself;
404  * but just recycling discarded Path nodes is a very useful savings in
405  * a large join tree. We can recycle the List nodes of pathlist, too.
406  *
407  * As noted in optimizer/README, deleting a previously-accepted Path is
408  * safe because we know that Paths of this rel cannot yet be referenced
409  * from any other rel, such as a higher-level join. However, in some cases
410  * it is possible that a Path is referenced by another Path for its own
411  * rel; we must not delete such a Path, even if it is dominated by the new
412  * Path. Currently this occurs only for IndexPath objects, which may be
413  * referenced as children of BitmapHeapPaths as well as being paths in
414  * their own right. Hence, we don't pfree IndexPaths when rejecting them.
415  *
416  * 'parent_rel' is the relation entry to which the path corresponds.
417  * 'new_path' is a potential path for parent_rel.
418  *
419  * Returns nothing, but modifies parent_rel->pathlist.
420  */
421 void
422 add_path(RelOptInfo *parent_rel, Path *new_path)
423 {
424  bool accept_new = true; /* unless we find a superior old path */
425  int insert_at = 0; /* where to insert new item */
426  List *new_path_pathkeys;
427  ListCell *p1;
428 
429  /*
430  * This is a convenient place to check for query cancel --- no part of the
431  * planner goes very long without calling add_path().
432  */
434 
435  /* Pretend parameterized paths have no pathkeys, per comment above */
436  new_path_pathkeys = new_path->param_info ? NIL : new_path->pathkeys;
437 
438  /*
439  * Loop to check proposed new path against old paths. Note it is possible
440  * for more than one old path to be tossed out because new_path dominates
441  * it.
442  */
443  foreach(p1, parent_rel->pathlist)
444  {
445  Path *old_path = (Path *) lfirst(p1);
446  bool remove_old = false; /* unless new proves superior */
447  PathCostComparison costcmp;
448  PathKeysComparison keyscmp;
449  BMS_Comparison outercmp;
450 
451  /*
452  * Do a fuzzy cost comparison with standard fuzziness limit.
453  */
454  costcmp = compare_path_costs_fuzzily(new_path, old_path,
456 
457  /*
458  * If the two paths compare differently for startup and total cost,
459  * then we want to keep both, and we can skip comparing pathkeys and
460  * required_outer rels. If they compare the same, proceed with the
461  * other comparisons. Row count is checked last. (We make the tests
462  * in this order because the cost comparison is most likely to turn
463  * out "different", and the pathkeys comparison next most likely. As
464  * explained above, row count very seldom makes a difference, so even
465  * though it's cheap to compare there's not much point in checking it
466  * earlier.)
467  */
468  if (costcmp != COSTS_DIFFERENT)
469  {
470  /* Similarly check to see if either dominates on pathkeys */
471  List *old_path_pathkeys;
472 
473  old_path_pathkeys = old_path->param_info ? NIL : old_path->pathkeys;
474  keyscmp = compare_pathkeys(new_path_pathkeys,
475  old_path_pathkeys);
476  if (keyscmp != PATHKEYS_DIFFERENT)
477  {
478  switch (costcmp)
479  {
480  case COSTS_EQUAL:
481  outercmp = bms_subset_compare(PATH_REQ_OUTER(new_path),
482  PATH_REQ_OUTER(old_path));
483  if (keyscmp == PATHKEYS_BETTER1)
484  {
485  if ((outercmp == BMS_EQUAL ||
486  outercmp == BMS_SUBSET1) &&
487  new_path->rows <= old_path->rows &&
488  new_path->parallel_safe >= old_path->parallel_safe)
489  remove_old = true; /* new dominates old */
490  }
491  else if (keyscmp == PATHKEYS_BETTER2)
492  {
493  if ((outercmp == BMS_EQUAL ||
494  outercmp == BMS_SUBSET2) &&
495  new_path->rows >= old_path->rows &&
496  new_path->parallel_safe <= old_path->parallel_safe)
497  accept_new = false; /* old dominates new */
498  }
499  else /* keyscmp == PATHKEYS_EQUAL */
500  {
501  if (outercmp == BMS_EQUAL)
502  {
503  /*
504  * Same pathkeys and outer rels, and fuzzily
505  * the same cost, so keep just one; to decide
506  * which, first check parallel-safety, then
507  * rows, then do a fuzzy cost comparison with
508  * very small fuzz limit. (We used to do an
509  * exact cost comparison, but that results in
510  * annoying platform-specific plan variations
511  * due to roundoff in the cost estimates.) If
512  * things are still tied, arbitrarily keep
513  * only the old path. Notice that we will
514  * keep only the old path even if the
515  * less-fuzzy comparison decides the startup
516  * and total costs compare differently.
517  */
518  if (new_path->parallel_safe >
519  old_path->parallel_safe)
520  remove_old = true; /* new dominates old */
521  else if (new_path->parallel_safe <
522  old_path->parallel_safe)
523  accept_new = false; /* old dominates new */
524  else if (new_path->rows < old_path->rows)
525  remove_old = true; /* new dominates old */
526  else if (new_path->rows > old_path->rows)
527  accept_new = false; /* old dominates new */
528  else if (compare_path_costs_fuzzily(new_path,
529  old_path,
530  1.0000000001) == COSTS_BETTER1)
531  remove_old = true; /* new dominates old */
532  else
533  accept_new = false; /* old equals or
534  * dominates new */
535  }
536  else if (outercmp == BMS_SUBSET1 &&
537  new_path->rows <= old_path->rows &&
538  new_path->parallel_safe >= old_path->parallel_safe)
539  remove_old = true; /* new dominates old */
540  else if (outercmp == BMS_SUBSET2 &&
541  new_path->rows >= old_path->rows &&
542  new_path->parallel_safe <= old_path->parallel_safe)
543  accept_new = false; /* old dominates new */
544  /* else different parameterizations, keep both */
545  }
546  break;
547  case COSTS_BETTER1:
548  if (keyscmp != PATHKEYS_BETTER2)
549  {
550  outercmp = bms_subset_compare(PATH_REQ_OUTER(new_path),
551  PATH_REQ_OUTER(old_path));
552  if ((outercmp == BMS_EQUAL ||
553  outercmp == BMS_SUBSET1) &&
554  new_path->rows <= old_path->rows &&
555  new_path->parallel_safe >= old_path->parallel_safe)
556  remove_old = true; /* new dominates old */
557  }
558  break;
559  case COSTS_BETTER2:
560  if (keyscmp != PATHKEYS_BETTER1)
561  {
562  outercmp = bms_subset_compare(PATH_REQ_OUTER(new_path),
563  PATH_REQ_OUTER(old_path));
564  if ((outercmp == BMS_EQUAL ||
565  outercmp == BMS_SUBSET2) &&
566  new_path->rows >= old_path->rows &&
567  new_path->parallel_safe <= old_path->parallel_safe)
568  accept_new = false; /* old dominates new */
569  }
570  break;
571  case COSTS_DIFFERENT:
572 
573  /*
574  * can't get here, but keep this case to keep compiler
575  * quiet
576  */
577  break;
578  }
579  }
580  }
581 
582  /*
583  * Remove current element from pathlist if dominated by new.
584  */
585  if (remove_old)
586  {
587  parent_rel->pathlist = foreach_delete_current(parent_rel->pathlist,
588  p1);
589 
590  /*
591  * Delete the data pointed-to by the deleted cell, if possible
592  */
593  if (!IsA(old_path, IndexPath))
594  pfree(old_path);
595  }
596  else
597  {
598  /* new belongs after this old path if it has cost >= old's */
599  if (new_path->total_cost >= old_path->total_cost)
600  insert_at = foreach_current_index(p1) + 1;
601  }
602 
603  /*
604  * If we found an old path that dominates new_path, we can quit
605  * scanning the pathlist; we will not add new_path, and we assume
606  * new_path cannot dominate any other elements of the pathlist.
607  */
608  if (!accept_new)
609  break;
610  }
611 
612  if (accept_new)
613  {
614  /* Accept the new path: insert it at proper place in pathlist */
615  parent_rel->pathlist =
616  list_insert_nth(parent_rel->pathlist, insert_at, new_path);
617  }
618  else
619  {
620  /* Reject and recycle the new path */
621  if (!IsA(new_path, IndexPath))
622  pfree(new_path);
623  }
624 }
625 
626 /*
627  * add_path_precheck
628  * Check whether a proposed new path could possibly get accepted.
629  * We assume we know the path's pathkeys and parameterization accurately,
630  * and have lower bounds for its costs.
631  *
632  * Note that we do not know the path's rowcount, since getting an estimate for
633  * that is too expensive to do before prechecking. We assume here that paths
634  * of a superset parameterization will generate fewer rows; if that holds,
635  * then paths with different parameterizations cannot dominate each other
636  * and so we can simply ignore existing paths of another parameterization.
637  * (In the infrequent cases where that rule of thumb fails, add_path will
638  * get rid of the inferior path.)
639  *
640  * At the time this is called, we haven't actually built a Path structure,
641  * so the required information has to be passed piecemeal.
642  */
643 bool
645  Cost startup_cost, Cost total_cost,
646  List *pathkeys, Relids required_outer)
647 {
648  List *new_path_pathkeys;
649  bool consider_startup;
650  ListCell *p1;
651 
652  /* Pretend parameterized paths have no pathkeys, per add_path policy */
653  new_path_pathkeys = required_outer ? NIL : pathkeys;
654 
655  /* Decide whether new path's startup cost is interesting */
656  consider_startup = required_outer ? parent_rel->consider_param_startup : parent_rel->consider_startup;
657 
658  foreach(p1, parent_rel->pathlist)
659  {
660  Path *old_path = (Path *) lfirst(p1);
661  PathKeysComparison keyscmp;
662 
663  /*
664  * We are looking for an old_path with the same parameterization (and
665  * by assumption the same rowcount) that dominates the new path on
666  * pathkeys as well as both cost metrics. If we find one, we can
667  * reject the new path.
668  *
669  * Cost comparisons here should match compare_path_costs_fuzzily.
670  */
671  if (total_cost > old_path->total_cost * STD_FUZZ_FACTOR)
672  {
673  /* new path can win on startup cost only if consider_startup */
674  if (startup_cost > old_path->startup_cost * STD_FUZZ_FACTOR ||
675  !consider_startup)
676  {
677  /* new path loses on cost, so check pathkeys... */
678  List *old_path_pathkeys;
679 
680  old_path_pathkeys = old_path->param_info ? NIL : old_path->pathkeys;
681  keyscmp = compare_pathkeys(new_path_pathkeys,
682  old_path_pathkeys);
683  if (keyscmp == PATHKEYS_EQUAL ||
684  keyscmp == PATHKEYS_BETTER2)
685  {
686  /* new path does not win on pathkeys... */
687  if (bms_equal(required_outer, PATH_REQ_OUTER(old_path)))
688  {
689  /* Found an old path that dominates the new one */
690  return false;
691  }
692  }
693  }
694  }
695  else
696  {
697  /*
698  * Since the pathlist is sorted by total_cost, we can stop looking
699  * once we reach a path with a total_cost larger than the new
700  * path's.
701  */
702  break;
703  }
704  }
705 
706  return true;
707 }
708 
709 /*
710  * add_partial_path
711  * Like add_path, our goal here is to consider whether a path is worthy
712  * of being kept around, but the considerations here are a bit different.
713  * A partial path is one which can be executed in any number of workers in
714  * parallel such that each worker will generate a subset of the path's
715  * overall result.
716  *
717  * As in add_path, the partial_pathlist is kept sorted with the cheapest
718  * total path in front. This is depended on by multiple places, which
719  * just take the front entry as the cheapest path without searching.
720  *
721  * We don't generate parameterized partial paths for several reasons. Most
722  * importantly, they're not safe to execute, because there's nothing to
723  * make sure that a parallel scan within the parameterized portion of the
724  * plan is running with the same value in every worker at the same time.
725  * Fortunately, it seems unlikely to be worthwhile anyway, because having
726  * each worker scan the entire outer relation and a subset of the inner
727  * relation will generally be a terrible plan. The inner (parameterized)
728  * side of the plan will be small anyway. There could be rare cases where
729  * this wins big - e.g. if join order constraints put a 1-row relation on
730  * the outer side of the topmost join with a parameterized plan on the inner
731  * side - but we'll have to be content not to handle such cases until
732  * somebody builds an executor infrastructure that can cope with them.
733  *
734  * Because we don't consider parameterized paths here, we also don't
735  * need to consider the row counts as a measure of quality: every path will
736  * produce the same number of rows. Neither do we need to consider startup
737  * costs: parallelism is only used for plans that will be run to completion.
738  * Therefore, this routine is much simpler than add_path: it needs to
739  * consider only pathkeys and total cost.
740  *
741  * As with add_path, we pfree paths that are found to be dominated by
742  * another partial path; this requires that there be no other references to
743  * such paths yet. Hence, GatherPaths must not be created for a rel until
744  * we're done creating all partial paths for it. Unlike add_path, we don't
745  * take an exception for IndexPaths as partial index paths won't be
746  * referenced by partial BitmapHeapPaths.
747  */
748 void
749 add_partial_path(RelOptInfo *parent_rel, Path *new_path)
750 {
751  bool accept_new = true; /* unless we find a superior old path */
752  int insert_at = 0; /* where to insert new item */
753  ListCell *p1;
754 
755  /* Check for query cancel. */
757 
758  /* Path to be added must be parallel safe. */
759  Assert(new_path->parallel_safe);
760 
761  /* Relation should be OK for parallelism, too. */
762  Assert(parent_rel->consider_parallel);
763 
764  /*
765  * As in add_path, throw out any paths which are dominated by the new
766  * path, but throw out the new path if some existing path dominates it.
767  */
768  foreach(p1, parent_rel->partial_pathlist)
769  {
770  Path *old_path = (Path *) lfirst(p1);
771  bool remove_old = false; /* unless new proves superior */
772  PathKeysComparison keyscmp;
773 
774  /* Compare pathkeys. */
775  keyscmp = compare_pathkeys(new_path->pathkeys, old_path->pathkeys);
776 
777  /* Unless pathkeys are incompatible, keep just one of the two paths. */
778  if (keyscmp != PATHKEYS_DIFFERENT)
779  {
780  if (new_path->total_cost > old_path->total_cost * STD_FUZZ_FACTOR)
781  {
782  /* New path costs more; keep it only if pathkeys are better. */
783  if (keyscmp != PATHKEYS_BETTER1)
784  accept_new = false;
785  }
786  else if (old_path->total_cost > new_path->total_cost
787  * STD_FUZZ_FACTOR)
788  {
789  /* Old path costs more; keep it only if pathkeys are better. */
790  if (keyscmp != PATHKEYS_BETTER2)
791  remove_old = true;
792  }
793  else if (keyscmp == PATHKEYS_BETTER1)
794  {
795  /* Costs are about the same, new path has better pathkeys. */
796  remove_old = true;
797  }
798  else if (keyscmp == PATHKEYS_BETTER2)
799  {
800  /* Costs are about the same, old path has better pathkeys. */
801  accept_new = false;
802  }
803  else if (old_path->total_cost > new_path->total_cost * 1.0000000001)
804  {
805  /* Pathkeys are the same, and the old path costs more. */
806  remove_old = true;
807  }
808  else
809  {
810  /*
811  * Pathkeys are the same, and new path isn't materially
812  * cheaper.
813  */
814  accept_new = false;
815  }
816  }
817 
818  /*
819  * Remove current element from partial_pathlist if dominated by new.
820  */
821  if (remove_old)
822  {
823  parent_rel->partial_pathlist =
824  foreach_delete_current(parent_rel->partial_pathlist, p1);
825  pfree(old_path);
826  }
827  else
828  {
829  /* new belongs after this old path if it has cost >= old's */
830  if (new_path->total_cost >= old_path->total_cost)
831  insert_at = foreach_current_index(p1) + 1;
832  }
833 
834  /*
835  * If we found an old path that dominates new_path, we can quit
836  * scanning the partial_pathlist; we will not add new_path, and we
837  * assume new_path cannot dominate any later path.
838  */
839  if (!accept_new)
840  break;
841  }
842 
843  if (accept_new)
844  {
845  /* Accept the new path: insert it at proper place */
846  parent_rel->partial_pathlist =
847  list_insert_nth(parent_rel->partial_pathlist, insert_at, new_path);
848  }
849  else
850  {
851  /* Reject and recycle the new path */
852  pfree(new_path);
853  }
854 }
855 
856 /*
857  * add_partial_path_precheck
858  * Check whether a proposed new partial path could possibly get accepted.
859  *
860  * Unlike add_path_precheck, we can ignore startup cost and parameterization,
861  * since they don't matter for partial paths (see add_partial_path). But
862  * we do want to make sure we don't add a partial path if there's already
863  * a complete path that dominates it, since in that case the proposed path
864  * is surely a loser.
865  */
866 bool
867 add_partial_path_precheck(RelOptInfo *parent_rel, Cost total_cost,
868  List *pathkeys)
869 {
870  ListCell *p1;
871 
872  /*
873  * Our goal here is twofold. First, we want to find out whether this path
874  * is clearly inferior to some existing partial path. If so, we want to
875  * reject it immediately. Second, we want to find out whether this path
876  * is clearly superior to some existing partial path -- at least, modulo
877  * final cost computations. If so, we definitely want to consider it.
878  *
879  * Unlike add_path(), we always compare pathkeys here. This is because we
880  * expect partial_pathlist to be very short, and getting a definitive
881  * answer at this stage avoids the need to call add_path_precheck.
882  */
883  foreach(p1, parent_rel->partial_pathlist)
884  {
885  Path *old_path = (Path *) lfirst(p1);
886  PathKeysComparison keyscmp;
887 
888  keyscmp = compare_pathkeys(pathkeys, old_path->pathkeys);
889  if (keyscmp != PATHKEYS_DIFFERENT)
890  {
891  if (total_cost > old_path->total_cost * STD_FUZZ_FACTOR &&
892  keyscmp != PATHKEYS_BETTER1)
893  return false;
894  if (old_path->total_cost > total_cost * STD_FUZZ_FACTOR &&
895  keyscmp != PATHKEYS_BETTER2)
896  return true;
897  }
898  }
899 
900  /*
901  * This path is neither clearly inferior to an existing partial path nor
902  * clearly good enough that it might replace one. Compare it to
903  * non-parallel plans. If it loses even before accounting for the cost of
904  * the Gather node, we should definitely reject it.
905  *
906  * Note that we pass the total_cost to add_path_precheck twice. This is
907  * because it's never advantageous to consider the startup cost of a
908  * partial path; the resulting plans, if run in parallel, will be run to
909  * completion.
910  */
911  if (!add_path_precheck(parent_rel, total_cost, total_cost, pathkeys,
912  NULL))
913  return false;
914 
915  return true;
916 }
917 
918 
919 /*****************************************************************************
920  * PATH NODE CREATION ROUTINES
921  *****************************************************************************/
922 
923 /*
924  * create_seqscan_path
925  * Creates a path corresponding to a sequential scan, returning the
926  * pathnode.
927  */
928 Path *
930  Relids required_outer, int parallel_workers)
931 {
932  Path *pathnode = makeNode(Path);
933 
934  pathnode->pathtype = T_SeqScan;
935  pathnode->parent = rel;
936  pathnode->pathtarget = rel->reltarget;
937  pathnode->param_info = get_baserel_parampathinfo(root, rel,
938  required_outer);
939  pathnode->parallel_aware = parallel_workers > 0 ? true : false;
940  pathnode->parallel_safe = rel->consider_parallel;
941  pathnode->parallel_workers = parallel_workers;
942  pathnode->pathkeys = NIL; /* seqscan has unordered result */
943 
944  cost_seqscan(pathnode, root, rel, pathnode->param_info);
945 
946  return pathnode;
947 }
948 
949 /*
950  * create_samplescan_path
951  * Creates a path node for a sampled table scan.
952  */
953 Path *
955 {
956  Path *pathnode = makeNode(Path);
957 
958  pathnode->pathtype = T_SampleScan;
959  pathnode->parent = rel;
960  pathnode->pathtarget = rel->reltarget;
961  pathnode->param_info = get_baserel_parampathinfo(root, rel,
962  required_outer);
963  pathnode->parallel_aware = false;
964  pathnode->parallel_safe = rel->consider_parallel;
965  pathnode->parallel_workers = 0;
966  pathnode->pathkeys = NIL; /* samplescan has unordered result */
967 
968  cost_samplescan(pathnode, root, rel, pathnode->param_info);
969 
970  return pathnode;
971 }
972 
973 /*
974  * create_index_path
975  * Creates a path node for an index scan.
976  *
977  * 'index' is a usable index.
978  * 'indexclauses' is a list of IndexClause nodes representing clauses
979  * to be enforced as qual conditions in the scan.
980  * 'indexorderbys' is a list of bare expressions (no RestrictInfos)
981  * to be used as index ordering operators in the scan.
982  * 'indexorderbycols' is an integer list of index column numbers (zero based)
983  * the ordering operators can be used with.
984  * 'pathkeys' describes the ordering of the path.
985  * 'indexscandir' is ForwardScanDirection or BackwardScanDirection
986  * for an ordered index, or NoMovementScanDirection for
987  * an unordered index.
988  * 'indexonly' is true if an index-only scan is wanted.
989  * 'required_outer' is the set of outer relids for a parameterized path.
990  * 'loop_count' is the number of repetitions of the indexscan to factor into
991  * estimates of caching behavior.
992  * 'partial_path' is true if constructing a parallel index scan path.
993  *
994  * Returns the new path node.
995  */
996 IndexPath *
999  List *indexclauses,
1000  List *indexorderbys,
1001  List *indexorderbycols,
1002  List *pathkeys,
1003  ScanDirection indexscandir,
1004  bool indexonly,
1005  Relids required_outer,
1006  double loop_count,
1007  bool partial_path)
1008 {
1009  IndexPath *pathnode = makeNode(IndexPath);
1010  RelOptInfo *rel = index->rel;
1011 
1012  pathnode->path.pathtype = indexonly ? T_IndexOnlyScan : T_IndexScan;
1013  pathnode->path.parent = rel;
1014  pathnode->path.pathtarget = rel->reltarget;
1015  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1016  required_outer);
1017  pathnode->path.parallel_aware = false;
1018  pathnode->path.parallel_safe = rel->consider_parallel;
1019  pathnode->path.parallel_workers = 0;
1020  pathnode->path.pathkeys = pathkeys;
1021 
1022  pathnode->indexinfo = index;
1023  pathnode->indexclauses = indexclauses;
1024  pathnode->indexorderbys = indexorderbys;
1025  pathnode->indexorderbycols = indexorderbycols;
1026  pathnode->indexscandir = indexscandir;
1027 
1028  cost_index(pathnode, root, loop_count, partial_path);
1029 
1030  return pathnode;
1031 }
1032 
1033 /*
1034  * create_bitmap_heap_path
1035  * Creates a path node for a bitmap scan.
1036  *
1037  * 'bitmapqual' is a tree of IndexPath, BitmapAndPath, and BitmapOrPath nodes.
1038  * 'required_outer' is the set of outer relids for a parameterized path.
1039  * 'loop_count' is the number of repetitions of the indexscan to factor into
1040  * estimates of caching behavior.
1041  *
1042  * loop_count should match the value used when creating the component
1043  * IndexPaths.
1044  */
1047  RelOptInfo *rel,
1048  Path *bitmapqual,
1049  Relids required_outer,
1050  double loop_count,
1051  int parallel_degree)
1052 {
1053  BitmapHeapPath *pathnode = makeNode(BitmapHeapPath);
1054 
1055  pathnode->path.pathtype = T_BitmapHeapScan;
1056  pathnode->path.parent = rel;
1057  pathnode->path.pathtarget = rel->reltarget;
1058  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1059  required_outer);
1060  pathnode->path.parallel_aware = parallel_degree > 0 ? true : false;
1061  pathnode->path.parallel_safe = rel->consider_parallel;
1062  pathnode->path.parallel_workers = parallel_degree;
1063  pathnode->path.pathkeys = NIL; /* always unordered */
1064 
1065  pathnode->bitmapqual = bitmapqual;
1066 
1067  cost_bitmap_heap_scan(&pathnode->path, root, rel,
1068  pathnode->path.param_info,
1069  bitmapqual, loop_count);
1070 
1071  return pathnode;
1072 }
1073 
1074 /*
1075  * create_bitmap_and_path
1076  * Creates a path node representing a BitmapAnd.
1077  */
1078 BitmapAndPath *
1080  RelOptInfo *rel,
1081  List *bitmapquals)
1082 {
1083  BitmapAndPath *pathnode = makeNode(BitmapAndPath);
1084 
1085  pathnode->path.pathtype = T_BitmapAnd;
1086  pathnode->path.parent = rel;
1087  pathnode->path.pathtarget = rel->reltarget;
1088  pathnode->path.param_info = NULL; /* not used in bitmap trees */
1089 
1090  /*
1091  * Currently, a BitmapHeapPath, BitmapAndPath, or BitmapOrPath will be
1092  * parallel-safe if and only if rel->consider_parallel is set. So, we can
1093  * set the flag for this path based only on the relation-level flag,
1094  * without actually iterating over the list of children.
1095  */
1096  pathnode->path.parallel_aware = false;
1097  pathnode->path.parallel_safe = rel->consider_parallel;
1098  pathnode->path.parallel_workers = 0;
1099 
1100  pathnode->path.pathkeys = NIL; /* always unordered */
1101 
1102  pathnode->bitmapquals = bitmapquals;
1103 
1104  /* this sets bitmapselectivity as well as the regular cost fields: */
1105  cost_bitmap_and_node(pathnode, root);
1106 
1107  return pathnode;
1108 }
1109 
1110 /*
1111  * create_bitmap_or_path
1112  * Creates a path node representing a BitmapOr.
1113  */
1114 BitmapOrPath *
1116  RelOptInfo *rel,
1117  List *bitmapquals)
1118 {
1119  BitmapOrPath *pathnode = makeNode(BitmapOrPath);
1120 
1121  pathnode->path.pathtype = T_BitmapOr;
1122  pathnode->path.parent = rel;
1123  pathnode->path.pathtarget = rel->reltarget;
1124  pathnode->path.param_info = NULL; /* not used in bitmap trees */
1125 
1126  /*
1127  * Currently, a BitmapHeapPath, BitmapAndPath, or BitmapOrPath will be
1128  * parallel-safe if and only if rel->consider_parallel is set. So, we can
1129  * set the flag for this path based only on the relation-level flag,
1130  * without actually iterating over the list of children.
1131  */
1132  pathnode->path.parallel_aware = false;
1133  pathnode->path.parallel_safe = rel->consider_parallel;
1134  pathnode->path.parallel_workers = 0;
1135 
1136  pathnode->path.pathkeys = NIL; /* always unordered */
1137 
1138  pathnode->bitmapquals = bitmapquals;
1139 
1140  /* this sets bitmapselectivity as well as the regular cost fields: */
1141  cost_bitmap_or_node(pathnode, root);
1142 
1143  return pathnode;
1144 }
1145 
1146 /*
1147  * create_tidscan_path
1148  * Creates a path corresponding to a scan by TID, returning the pathnode.
1149  */
1150 TidPath *
1152  Relids required_outer)
1153 {
1154  TidPath *pathnode = makeNode(TidPath);
1155 
1156  pathnode->path.pathtype = T_TidScan;
1157  pathnode->path.parent = rel;
1158  pathnode->path.pathtarget = rel->reltarget;
1159  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1160  required_outer);
1161  pathnode->path.parallel_aware = false;
1162  pathnode->path.parallel_safe = rel->consider_parallel;
1163  pathnode->path.parallel_workers = 0;
1164  pathnode->path.pathkeys = NIL; /* always unordered */
1165 
1166  pathnode->tidquals = tidquals;
1167 
1168  cost_tidscan(&pathnode->path, root, rel, tidquals,
1169  pathnode->path.param_info);
1170 
1171  return pathnode;
1172 }
1173 
1174 /*
1175  * create_append_path
1176  * Creates a path corresponding to an Append plan, returning the
1177  * pathnode.
1178  *
1179  * Note that we must handle subpaths = NIL, representing a dummy access path.
1180  * Also, there are callers that pass root = NULL.
1181  */
1182 AppendPath *
1184  RelOptInfo *rel,
1185  List *subpaths, List *partial_subpaths,
1186  List *pathkeys, Relids required_outer,
1187  int parallel_workers, bool parallel_aware,
1188  List *partitioned_rels, double rows)
1189 {
1190  AppendPath *pathnode = makeNode(AppendPath);
1191  ListCell *l;
1192 
1193  Assert(!parallel_aware || parallel_workers > 0);
1194 
1195  pathnode->path.pathtype = T_Append;
1196  pathnode->path.parent = rel;
1197  pathnode->path.pathtarget = rel->reltarget;
1198 
1199  /*
1200  * When generating an Append path for a partitioned table, there may be
1201  * parameters that are useful so we can eliminate certain partitions
1202  * during execution. Here we'll go all the way and fully populate the
1203  * parameter info data as we do for normal base relations. However, we
1204  * need only bother doing this for RELOPT_BASEREL rels, as
1205  * RELOPT_OTHER_MEMBER_REL's Append paths are merged into the base rel's
1206  * Append subpaths. It would do no harm to do this, we just avoid it to
1207  * save wasting effort.
1208  */
1209  if (partitioned_rels != NIL && root && rel->reloptkind == RELOPT_BASEREL)
1210  pathnode->path.param_info = get_baserel_parampathinfo(root,
1211  rel,
1212  required_outer);
1213  else
1215  required_outer);
1216 
1217  pathnode->path.parallel_aware = parallel_aware;
1218  pathnode->path.parallel_safe = rel->consider_parallel;
1219  pathnode->path.parallel_workers = parallel_workers;
1220  pathnode->path.pathkeys = pathkeys;
1221  pathnode->partitioned_rels = list_copy(partitioned_rels);
1222 
1223  /*
1224  * For parallel append, non-partial paths are sorted by descending total
1225  * costs. That way, the total time to finish all non-partial paths is
1226  * minimized. Also, the partial paths are sorted by descending startup
1227  * costs. There may be some paths that require to do startup work by a
1228  * single worker. In such case, it's better for workers to choose the
1229  * expensive ones first, whereas the leader should choose the cheapest
1230  * startup plan.
1231  */
1232  if (pathnode->path.parallel_aware)
1233  {
1234  /*
1235  * We mustn't fiddle with the order of subpaths when the Append has
1236  * pathkeys. The order they're listed in is critical to keeping the
1237  * pathkeys valid.
1238  */
1239  Assert(pathkeys == NIL);
1240 
1242  list_sort(partial_subpaths, append_startup_cost_compare);
1243  }
1244  pathnode->first_partial_path = list_length(subpaths);
1245  pathnode->subpaths = list_concat(subpaths, partial_subpaths);
1246 
1247  /*
1248  * Apply query-wide LIMIT if known and path is for sole base relation.
1249  * (Handling this at this low level is a bit klugy.)
1250  */
1251  if (root != NULL && bms_equal(rel->relids, root->all_baserels))
1252  pathnode->limit_tuples = root->limit_tuples;
1253  else
1254  pathnode->limit_tuples = -1.0;
1255 
1256  foreach(l, pathnode->subpaths)
1257  {
1258  Path *subpath = (Path *) lfirst(l);
1259 
1260  pathnode->path.parallel_safe = pathnode->path.parallel_safe &&
1261  subpath->parallel_safe;
1262 
1263  /* All child paths must have same parameterization */
1264  Assert(bms_equal(PATH_REQ_OUTER(subpath), required_outer));
1265  }
1266 
1267  Assert(!parallel_aware || pathnode->path.parallel_safe);
1268 
1269  /*
1270  * If there's exactly one child path, the Append is a no-op and will be
1271  * discarded later (in setrefs.c); therefore, we can inherit the child's
1272  * size and cost, as well as its pathkeys if any (overriding whatever the
1273  * caller might've said). Otherwise, we must do the normal costsize
1274  * calculation.
1275  */
1276  if (list_length(pathnode->subpaths) == 1)
1277  {
1278  Path *child = (Path *) linitial(pathnode->subpaths);
1279 
1280  pathnode->path.rows = child->rows;
1281  pathnode->path.startup_cost = child->startup_cost;
1282  pathnode->path.total_cost = child->total_cost;
1283  pathnode->path.pathkeys = child->pathkeys;
1284  }
1285  else
1286  cost_append(pathnode);
1287 
1288  /* If the caller provided a row estimate, override the computed value. */
1289  if (rows >= 0)
1290  pathnode->path.rows = rows;
1291 
1292  return pathnode;
1293 }
1294 
1295 /*
1296  * append_total_cost_compare
1297  * list_sort comparator for sorting append child paths
1298  * by total_cost descending
1299  *
1300  * For equal total costs, we fall back to comparing startup costs; if those
1301  * are equal too, break ties using bms_compare on the paths' relids.
1302  * (This is to avoid getting unpredictable results from list_sort.)
1303  */
1304 static int
1306 {
1307  Path *path1 = (Path *) lfirst(a);
1308  Path *path2 = (Path *) lfirst(b);
1309  int cmp;
1310 
1311  cmp = compare_path_costs(path1, path2, TOTAL_COST);
1312  if (cmp != 0)
1313  return -cmp;
1314  return bms_compare(path1->parent->relids, path2->parent->relids);
1315 }
1316 
1317 /*
1318  * append_startup_cost_compare
1319  * list_sort comparator for sorting append child paths
1320  * by startup_cost descending
1321  *
1322  * For equal startup costs, we fall back to comparing total costs; if those
1323  * are equal too, break ties using bms_compare on the paths' relids.
1324  * (This is to avoid getting unpredictable results from list_sort.)
1325  */
1326 static int
1328 {
1329  Path *path1 = (Path *) lfirst(a);
1330  Path *path2 = (Path *) lfirst(b);
1331  int cmp;
1332 
1333  cmp = compare_path_costs(path1, path2, STARTUP_COST);
1334  if (cmp != 0)
1335  return -cmp;
1336  return bms_compare(path1->parent->relids, path2->parent->relids);
1337 }
1338 
1339 /*
1340  * create_merge_append_path
1341  * Creates a path corresponding to a MergeAppend plan, returning the
1342  * pathnode.
1343  */
1346  RelOptInfo *rel,
1347  List *subpaths,
1348  List *pathkeys,
1349  Relids required_outer,
1350  List *partitioned_rels)
1351 {
1353  Cost input_startup_cost;
1354  Cost input_total_cost;
1355  ListCell *l;
1356 
1357  pathnode->path.pathtype = T_MergeAppend;
1358  pathnode->path.parent = rel;
1359  pathnode->path.pathtarget = rel->reltarget;
1361  required_outer);
1362  pathnode->path.parallel_aware = false;
1363  pathnode->path.parallel_safe = rel->consider_parallel;
1364  pathnode->path.parallel_workers = 0;
1365  pathnode->path.pathkeys = pathkeys;
1366  pathnode->partitioned_rels = list_copy(partitioned_rels);
1367  pathnode->subpaths = subpaths;
1368 
1369  /*
1370  * Apply query-wide LIMIT if known and path is for sole base relation.
1371  * (Handling this at this low level is a bit klugy.)
1372  */
1373  if (bms_equal(rel->relids, root->all_baserels))
1374  pathnode->limit_tuples = root->limit_tuples;
1375  else
1376  pathnode->limit_tuples = -1.0;
1377 
1378  /*
1379  * Add up the sizes and costs of the input paths.
1380  */
1381  pathnode->path.rows = 0;
1382  input_startup_cost = 0;
1383  input_total_cost = 0;
1384  foreach(l, subpaths)
1385  {
1386  Path *subpath = (Path *) lfirst(l);
1387 
1388  pathnode->path.rows += subpath->rows;
1389  pathnode->path.parallel_safe = pathnode->path.parallel_safe &&
1390  subpath->parallel_safe;
1391 
1392  if (pathkeys_contained_in(pathkeys, subpath->pathkeys))
1393  {
1394  /* Subpath is adequately ordered, we won't need to sort it */
1395  input_startup_cost += subpath->startup_cost;
1396  input_total_cost += subpath->total_cost;
1397  }
1398  else
1399  {
1400  /* We'll need to insert a Sort node, so include cost for that */
1401  Path sort_path; /* dummy for result of cost_sort */
1402 
1403  cost_sort(&sort_path,
1404  root,
1405  pathkeys,
1406  subpath->total_cost,
1407  subpath->parent->tuples,
1408  subpath->pathtarget->width,
1409  0.0,
1410  work_mem,
1411  pathnode->limit_tuples);
1412  input_startup_cost += sort_path.startup_cost;
1413  input_total_cost += sort_path.total_cost;
1414  }
1415 
1416  /* All child paths must have same parameterization */
1417  Assert(bms_equal(PATH_REQ_OUTER(subpath), required_outer));
1418  }
1419 
1420  /*
1421  * Now we can compute total costs of the MergeAppend. If there's exactly
1422  * one child path, the MergeAppend is a no-op and will be discarded later
1423  * (in setrefs.c); otherwise we do the normal cost calculation.
1424  */
1425  if (list_length(subpaths) == 1)
1426  {
1427  pathnode->path.startup_cost = input_startup_cost;
1428  pathnode->path.total_cost = input_total_cost;
1429  }
1430  else
1431  cost_merge_append(&pathnode->path, root,
1432  pathkeys, list_length(subpaths),
1433  input_startup_cost, input_total_cost,
1434  pathnode->path.rows);
1435 
1436  return pathnode;
1437 }
1438 
1439 /*
1440  * create_group_result_path
1441  * Creates a path representing a Result-and-nothing-else plan.
1442  *
1443  * This is only used for degenerate grouping cases, in which we know we
1444  * need to produce one result row, possibly filtered by a HAVING qual.
1445  */
1448  PathTarget *target, List *havingqual)
1449 {
1451 
1452  pathnode->path.pathtype = T_Result;
1453  pathnode->path.parent = rel;
1454  pathnode->path.pathtarget = target;
1455  pathnode->path.param_info = NULL; /* there are no other rels... */
1456  pathnode->path.parallel_aware = false;
1457  pathnode->path.parallel_safe = rel->consider_parallel;
1458  pathnode->path.parallel_workers = 0;
1459  pathnode->path.pathkeys = NIL;
1460  pathnode->quals = havingqual;
1461 
1462  /*
1463  * We can't quite use cost_resultscan() because the quals we want to
1464  * account for are not baserestrict quals of the rel. Might as well just
1465  * hack it here.
1466  */
1467  pathnode->path.rows = 1;
1468  pathnode->path.startup_cost = target->cost.startup;
1469  pathnode->path.total_cost = target->cost.startup +
1470  cpu_tuple_cost + target->cost.per_tuple;
1471 
1472  /*
1473  * Add cost of qual, if any --- but we ignore its selectivity, since our
1474  * rowcount estimate should be 1 no matter what the qual is.
1475  */
1476  if (havingqual)
1477  {
1478  QualCost qual_cost;
1479 
1480  cost_qual_eval(&qual_cost, havingqual, root);
1481  /* havingqual is evaluated once at startup */
1482  pathnode->path.startup_cost += qual_cost.startup + qual_cost.per_tuple;
1483  pathnode->path.total_cost += qual_cost.startup + qual_cost.per_tuple;
1484  }
1485 
1486  return pathnode;
1487 }
1488 
1489 /*
1490  * create_material_path
1491  * Creates a path corresponding to a Material plan, returning the
1492  * pathnode.
1493  */
1494 MaterialPath *
1496 {
1497  MaterialPath *pathnode = makeNode(MaterialPath);
1498 
1499  Assert(subpath->parent == rel);
1500 
1501  pathnode->path.pathtype = T_Material;
1502  pathnode->path.parent = rel;
1503  pathnode->path.pathtarget = rel->reltarget;
1504  pathnode->path.param_info = subpath->param_info;
1505  pathnode->path.parallel_aware = false;
1506  pathnode->path.parallel_safe = rel->consider_parallel &&
1507  subpath->parallel_safe;
1508  pathnode->path.parallel_workers = subpath->parallel_workers;
1509  pathnode->path.pathkeys = subpath->pathkeys;
1510 
1511  pathnode->subpath = subpath;
1512 
1513  cost_material(&pathnode->path,
1514  subpath->startup_cost,
1515  subpath->total_cost,
1516  subpath->rows,
1517  subpath->pathtarget->width);
1518 
1519  return pathnode;
1520 }
1521 
1522 /*
1523  * create_unique_path
1524  * Creates a path representing elimination of distinct rows from the
1525  * input data. Distinct-ness is defined according to the needs of the
1526  * semijoin represented by sjinfo. If it is not possible to identify
1527  * how to make the data unique, NULL is returned.
1528  *
1529  * If used at all, this is likely to be called repeatedly on the same rel;
1530  * and the input subpath should always be the same (the cheapest_total path
1531  * for the rel). So we cache the result.
1532  */
1533 UniquePath *
1535  SpecialJoinInfo *sjinfo)
1536 {
1537  UniquePath *pathnode;
1538  Path sort_path; /* dummy for result of cost_sort */
1539  Path agg_path; /* dummy for result of cost_agg */
1540  MemoryContext oldcontext;
1541  int numCols;
1542 
1543  /* Caller made a mistake if subpath isn't cheapest_total ... */
1544  Assert(subpath == rel->cheapest_total_path);
1545  Assert(subpath->parent == rel);
1546  /* ... or if SpecialJoinInfo is the wrong one */
1547  Assert(sjinfo->jointype == JOIN_SEMI);
1548  Assert(bms_equal(rel->relids, sjinfo->syn_righthand));
1549 
1550  /* If result already cached, return it */
1551  if (rel->cheapest_unique_path)
1552  return (UniquePath *) rel->cheapest_unique_path;
1553 
1554  /* If it's not possible to unique-ify, return NULL */
1555  if (!(sjinfo->semi_can_btree || sjinfo->semi_can_hash))
1556  return NULL;
1557 
1558  /*
1559  * When called during GEQO join planning, we are in a short-lived memory
1560  * context. We must make sure that the path and any subsidiary data
1561  * structures created for a baserel survive the GEQO cycle, else the
1562  * baserel is trashed for future GEQO cycles. On the other hand, when we
1563  * are creating those for a joinrel during GEQO, we don't want them to
1564  * clutter the main planning context. Upshot is that the best solution is
1565  * to explicitly allocate memory in the same context the given RelOptInfo
1566  * is in.
1567  */
1568  oldcontext = MemoryContextSwitchTo(GetMemoryChunkContext(rel));
1569 
1570  pathnode = makeNode(UniquePath);
1571 
1572  pathnode->path.pathtype = T_Unique;
1573  pathnode->path.parent = rel;
1574  pathnode->path.pathtarget = rel->reltarget;
1575  pathnode->path.param_info = subpath->param_info;
1576  pathnode->path.parallel_aware = false;
1577  pathnode->path.parallel_safe = rel->consider_parallel &&
1578  subpath->parallel_safe;
1579  pathnode->path.parallel_workers = subpath->parallel_workers;
1580 
1581  /*
1582  * Assume the output is unsorted, since we don't necessarily have pathkeys
1583  * to represent it. (This might get overridden below.)
1584  */
1585  pathnode->path.pathkeys = NIL;
1586 
1587  pathnode->subpath = subpath;
1588  pathnode->in_operators = sjinfo->semi_operators;
1589  pathnode->uniq_exprs = sjinfo->semi_rhs_exprs;
1590 
1591  /*
1592  * If the input is a relation and it has a unique index that proves the
1593  * semi_rhs_exprs are unique, then we don't need to do anything. Note
1594  * that relation_has_unique_index_for automatically considers restriction
1595  * clauses for the rel, as well.
1596  */
1597  if (rel->rtekind == RTE_RELATION && sjinfo->semi_can_btree &&
1599  sjinfo->semi_rhs_exprs,
1600  sjinfo->semi_operators))
1601  {
1602  pathnode->umethod = UNIQUE_PATH_NOOP;
1603  pathnode->path.rows = rel->rows;
1604  pathnode->path.startup_cost = subpath->startup_cost;
1605  pathnode->path.total_cost = subpath->total_cost;
1606  pathnode->path.pathkeys = subpath->pathkeys;
1607 
1608  rel->cheapest_unique_path = (Path *) pathnode;
1609 
1610  MemoryContextSwitchTo(oldcontext);
1611 
1612  return pathnode;
1613  }
1614 
1615  /*
1616  * If the input is a subquery whose output must be unique already, then we
1617  * don't need to do anything. The test for uniqueness has to consider
1618  * exactly which columns we are extracting; for example "SELECT DISTINCT
1619  * x,y" doesn't guarantee that x alone is distinct. So we cannot check for
1620  * this optimization unless semi_rhs_exprs consists only of simple Vars
1621  * referencing subquery outputs. (Possibly we could do something with
1622  * expressions in the subquery outputs, too, but for now keep it simple.)
1623  */
1624  if (rel->rtekind == RTE_SUBQUERY)
1625  {
1626  RangeTblEntry *rte = planner_rt_fetch(rel->relid, root);
1627 
1629  {
1630  List *sub_tlist_colnos;
1631 
1632  sub_tlist_colnos = translate_sub_tlist(sjinfo->semi_rhs_exprs,
1633  rel->relid);
1634 
1635  if (sub_tlist_colnos &&
1637  sub_tlist_colnos,
1638  sjinfo->semi_operators))
1639  {
1640  pathnode->umethod = UNIQUE_PATH_NOOP;
1641  pathnode->path.rows = rel->rows;
1642  pathnode->path.startup_cost = subpath->startup_cost;
1643  pathnode->path.total_cost = subpath->total_cost;
1644  pathnode->path.pathkeys = subpath->pathkeys;
1645 
1646  rel->cheapest_unique_path = (Path *) pathnode;
1647 
1648  MemoryContextSwitchTo(oldcontext);
1649 
1650  return pathnode;
1651  }
1652  }
1653  }
1654 
1655  /* Estimate number of output rows */
1656  pathnode->path.rows = estimate_num_groups(root,
1657  sjinfo->semi_rhs_exprs,
1658  rel->rows,
1659  NULL);
1660  numCols = list_length(sjinfo->semi_rhs_exprs);
1661 
1662  if (sjinfo->semi_can_btree)
1663  {
1664  /*
1665  * Estimate cost for sort+unique implementation
1666  */
1667  cost_sort(&sort_path, root, NIL,
1668  subpath->total_cost,
1669  rel->rows,
1670  subpath->pathtarget->width,
1671  0.0,
1672  work_mem,
1673  -1.0);
1674 
1675  /*
1676  * Charge one cpu_operator_cost per comparison per input tuple. We
1677  * assume all columns get compared at most of the tuples. (XXX
1678  * probably this is an overestimate.) This should agree with
1679  * create_upper_unique_path.
1680  */
1681  sort_path.total_cost += cpu_operator_cost * rel->rows * numCols;
1682  }
1683 
1684  if (sjinfo->semi_can_hash)
1685  {
1686  /*
1687  * Estimate the overhead per hashtable entry at 64 bytes (same as in
1688  * planner.c).
1689  */
1690  int hashentrysize = subpath->pathtarget->width + 64;
1691 
1692  if (hashentrysize * pathnode->path.rows > work_mem * 1024L)
1693  {
1694  /*
1695  * We should not try to hash. Hack the SpecialJoinInfo to
1696  * remember this, in case we come through here again.
1697  */
1698  sjinfo->semi_can_hash = false;
1699  }
1700  else
1701  cost_agg(&agg_path, root,
1702  AGG_HASHED, NULL,
1703  numCols, pathnode->path.rows,
1704  NIL,
1705  subpath->startup_cost,
1706  subpath->total_cost,
1707  rel->rows,
1708  subpath->pathtarget->width);
1709  }
1710 
1711  if (sjinfo->semi_can_btree && sjinfo->semi_can_hash)
1712  {
1713  if (agg_path.total_cost < sort_path.total_cost)
1714  pathnode->umethod = UNIQUE_PATH_HASH;
1715  else
1716  pathnode->umethod = UNIQUE_PATH_SORT;
1717  }
1718  else if (sjinfo->semi_can_btree)
1719  pathnode->umethod = UNIQUE_PATH_SORT;
1720  else if (sjinfo->semi_can_hash)
1721  pathnode->umethod = UNIQUE_PATH_HASH;
1722  else
1723  {
1724  /* we can get here only if we abandoned hashing above */
1725  MemoryContextSwitchTo(oldcontext);
1726  return NULL;
1727  }
1728 
1729  if (pathnode->umethod == UNIQUE_PATH_HASH)
1730  {
1731  pathnode->path.startup_cost = agg_path.startup_cost;
1732  pathnode->path.total_cost = agg_path.total_cost;
1733  }
1734  else
1735  {
1736  pathnode->path.startup_cost = sort_path.startup_cost;
1737  pathnode->path.total_cost = sort_path.total_cost;
1738  }
1739 
1740  rel->cheapest_unique_path = (Path *) pathnode;
1741 
1742  MemoryContextSwitchTo(oldcontext);
1743 
1744  return pathnode;
1745 }
1746 
1747 /*
1748  * create_gather_merge_path
1749  *
1750  * Creates a path corresponding to a gather merge scan, returning
1751  * the pathnode.
1752  */
1755  PathTarget *target, List *pathkeys,
1756  Relids required_outer, double *rows)
1757 {
1759  Cost input_startup_cost = 0;
1760  Cost input_total_cost = 0;
1761 
1762  Assert(subpath->parallel_safe);
1763  Assert(pathkeys);
1764 
1765  pathnode->path.pathtype = T_GatherMerge;
1766  pathnode->path.parent = rel;
1767  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1768  required_outer);
1769  pathnode->path.parallel_aware = false;
1770 
1771  pathnode->subpath = subpath;
1772  pathnode->num_workers = subpath->parallel_workers;
1773  pathnode->path.pathkeys = pathkeys;
1774  pathnode->path.pathtarget = target ? target : rel->reltarget;
1775  pathnode->path.rows += subpath->rows;
1776 
1777  if (pathkeys_contained_in(pathkeys, subpath->pathkeys))
1778  {
1779  /* Subpath is adequately ordered, we won't need to sort it */
1780  input_startup_cost += subpath->startup_cost;
1781  input_total_cost += subpath->total_cost;
1782  }
1783  else
1784  {
1785  /* We'll need to insert a Sort node, so include cost for that */
1786  Path sort_path; /* dummy for result of cost_sort */
1787 
1788  cost_sort(&sort_path,
1789  root,
1790  pathkeys,
1791  subpath->total_cost,
1792  subpath->rows,
1793  subpath->pathtarget->width,
1794  0.0,
1795  work_mem,
1796  -1);
1797  input_startup_cost += sort_path.startup_cost;
1798  input_total_cost += sort_path.total_cost;
1799  }
1800 
1801  cost_gather_merge(pathnode, root, rel, pathnode->path.param_info,
1802  input_startup_cost, input_total_cost, rows);
1803 
1804  return pathnode;
1805 }
1806 
1807 /*
1808  * translate_sub_tlist - get subquery column numbers represented by tlist
1809  *
1810  * The given targetlist usually contains only Vars referencing the given relid.
1811  * Extract their varattnos (ie, the column numbers of the subquery) and return
1812  * as an integer List.
1813  *
1814  * If any of the tlist items is not a simple Var, we cannot determine whether
1815  * the subquery's uniqueness condition (if any) matches ours, so punt and
1816  * return NIL.
1817  */
1818 static List *
1819 translate_sub_tlist(List *tlist, int relid)
1820 {
1821  List *result = NIL;
1822  ListCell *l;
1823 
1824  foreach(l, tlist)
1825  {
1826  Var *var = (Var *) lfirst(l);
1827 
1828  if (!var || !IsA(var, Var) ||
1829  var->varno != relid)
1830  return NIL; /* punt */
1831 
1832  result = lappend_int(result, var->varattno);
1833  }
1834  return result;
1835 }
1836 
1837 /*
1838  * create_gather_path
1839  * Creates a path corresponding to a gather scan, returning the
1840  * pathnode.
1841  *
1842  * 'rows' may optionally be set to override row estimates from other sources.
1843  */
1844 GatherPath *
1846  PathTarget *target, Relids required_outer, double *rows)
1847 {
1848  GatherPath *pathnode = makeNode(GatherPath);
1849 
1850  Assert(subpath->parallel_safe);
1851 
1852  pathnode->path.pathtype = T_Gather;
1853  pathnode->path.parent = rel;
1854  pathnode->path.pathtarget = target;
1855  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1856  required_outer);
1857  pathnode->path.parallel_aware = false;
1858  pathnode->path.parallel_safe = false;
1859  pathnode->path.parallel_workers = 0;
1860  pathnode->path.pathkeys = NIL; /* Gather has unordered result */
1861 
1862  pathnode->subpath = subpath;
1863  pathnode->num_workers = subpath->parallel_workers;
1864  pathnode->single_copy = false;
1865 
1866  if (pathnode->num_workers == 0)
1867  {
1868  pathnode->path.pathkeys = subpath->pathkeys;
1869  pathnode->num_workers = 1;
1870  pathnode->single_copy = true;
1871  }
1872 
1873  cost_gather(pathnode, root, rel, pathnode->path.param_info, rows);
1874 
1875  return pathnode;
1876 }
1877 
1878 /*
1879  * create_subqueryscan_path
1880  * Creates a path corresponding to a scan of a subquery,
1881  * returning the pathnode.
1882  */
1885  List *pathkeys, Relids required_outer)
1886 {
1888 
1889  pathnode->path.pathtype = T_SubqueryScan;
1890  pathnode->path.parent = rel;
1891  pathnode->path.pathtarget = rel->reltarget;
1892  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1893  required_outer);
1894  pathnode->path.parallel_aware = false;
1895  pathnode->path.parallel_safe = rel->consider_parallel &&
1896  subpath->parallel_safe;
1897  pathnode->path.parallel_workers = subpath->parallel_workers;
1898  pathnode->path.pathkeys = pathkeys;
1899  pathnode->subpath = subpath;
1900 
1901  cost_subqueryscan(pathnode, root, rel, pathnode->path.param_info);
1902 
1903  return pathnode;
1904 }
1905 
1906 /*
1907  * create_functionscan_path
1908  * Creates a path corresponding to a sequential scan of a function,
1909  * returning the pathnode.
1910  */
1911 Path *
1913  List *pathkeys, Relids required_outer)
1914 {
1915  Path *pathnode = makeNode(Path);
1916 
1917  pathnode->pathtype = T_FunctionScan;
1918  pathnode->parent = rel;
1919  pathnode->pathtarget = rel->reltarget;
1920  pathnode->param_info = get_baserel_parampathinfo(root, rel,
1921  required_outer);
1922  pathnode->parallel_aware = false;
1923  pathnode->parallel_safe = rel->consider_parallel;
1924  pathnode->parallel_workers = 0;
1925  pathnode->pathkeys = pathkeys;
1926 
1927  cost_functionscan(pathnode, root, rel, pathnode->param_info);
1928 
1929  return pathnode;
1930 }
1931 
1932 /*
1933  * create_tablefuncscan_path
1934  * Creates a path corresponding to a sequential scan of a table function,
1935  * returning the pathnode.
1936  */
1937 Path *
1939  Relids required_outer)
1940 {
1941  Path *pathnode = makeNode(Path);
1942 
1943  pathnode->pathtype = T_TableFuncScan;
1944  pathnode->parent = rel;
1945  pathnode->pathtarget = rel->reltarget;
1946  pathnode->param_info = get_baserel_parampathinfo(root, rel,
1947  required_outer);
1948  pathnode->parallel_aware = false;
1949  pathnode->parallel_safe = rel->consider_parallel;
1950  pathnode->parallel_workers = 0;
1951  pathnode->pathkeys = NIL; /* result is always unordered */
1952 
1953  cost_tablefuncscan(pathnode, root, rel, pathnode->param_info);
1954 
1955  return pathnode;
1956 }
1957 
1958 /*
1959  * create_valuesscan_path
1960  * Creates a path corresponding to a scan of a VALUES list,
1961  * returning the pathnode.
1962  */
1963 Path *
1965  Relids required_outer)
1966 {
1967  Path *pathnode = makeNode(Path);
1968 
1969  pathnode->pathtype = T_ValuesScan;
1970  pathnode->parent = rel;
1971  pathnode->pathtarget = rel->reltarget;
1972  pathnode->param_info = get_baserel_parampathinfo(root, rel,
1973  required_outer);
1974  pathnode->parallel_aware = false;
1975  pathnode->parallel_safe = rel->consider_parallel;
1976  pathnode->parallel_workers = 0;
1977  pathnode->pathkeys = NIL; /* result is always unordered */
1978 
1979  cost_valuesscan(pathnode, root, rel, pathnode->param_info);
1980 
1981  return pathnode;
1982 }
1983 
1984 /*
1985  * create_ctescan_path
1986  * Creates a path corresponding to a scan of a non-self-reference CTE,
1987  * returning the pathnode.
1988  */
1989 Path *
1990 create_ctescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
1991 {
1992  Path *pathnode = makeNode(Path);
1993 
1994  pathnode->pathtype = T_CteScan;
1995  pathnode->parent = rel;
1996  pathnode->pathtarget = rel->reltarget;
1997  pathnode->param_info = get_baserel_parampathinfo(root, rel,
1998  required_outer);
1999  pathnode->parallel_aware = false;
2000  pathnode->parallel_safe = rel->consider_parallel;
2001  pathnode->parallel_workers = 0;
2002  pathnode->pathkeys = NIL; /* XXX for now, result is always unordered */
2003 
2004  cost_ctescan(pathnode, root, rel, pathnode->param_info);
2005 
2006  return pathnode;
2007 }
2008 
2009 /*
2010  * create_namedtuplestorescan_path
2011  * Creates a path corresponding to a scan of a named tuplestore, returning
2012  * the pathnode.
2013  */
2014 Path *
2016  Relids required_outer)
2017 {
2018  Path *pathnode = makeNode(Path);
2019 
2020  pathnode->pathtype = T_NamedTuplestoreScan;
2021  pathnode->parent = rel;
2022  pathnode->pathtarget = rel->reltarget;
2023  pathnode->param_info = get_baserel_parampathinfo(root, rel,
2024  required_outer);
2025  pathnode->parallel_aware = false;
2026  pathnode->parallel_safe = rel->consider_parallel;
2027  pathnode->parallel_workers = 0;
2028  pathnode->pathkeys = NIL; /* result is always unordered */
2029 
2030  cost_namedtuplestorescan(pathnode, root, rel, pathnode->param_info);
2031 
2032  return pathnode;
2033 }
2034 
2035 /*
2036  * create_resultscan_path
2037  * Creates a path corresponding to a scan of an RTE_RESULT relation,
2038  * returning the pathnode.
2039  */
2040 Path *
2042  Relids required_outer)
2043 {
2044  Path *pathnode = makeNode(Path);
2045 
2046  pathnode->pathtype = T_Result;
2047  pathnode->parent = rel;
2048  pathnode->pathtarget = rel->reltarget;
2049  pathnode->param_info = get_baserel_parampathinfo(root, rel,
2050  required_outer);
2051  pathnode->parallel_aware = false;
2052  pathnode->parallel_safe = rel->consider_parallel;
2053  pathnode->parallel_workers = 0;
2054  pathnode->pathkeys = NIL; /* result is always unordered */
2055 
2056  cost_resultscan(pathnode, root, rel, pathnode->param_info);
2057 
2058  return pathnode;
2059 }
2060 
2061 /*
2062  * create_worktablescan_path
2063  * Creates a path corresponding to a scan of a self-reference CTE,
2064  * returning the pathnode.
2065  */
2066 Path *
2068  Relids required_outer)
2069 {
2070  Path *pathnode = makeNode(Path);
2071 
2072  pathnode->pathtype = T_WorkTableScan;
2073  pathnode->parent = rel;
2074  pathnode->pathtarget = rel->reltarget;
2075  pathnode->param_info = get_baserel_parampathinfo(root, rel,
2076  required_outer);
2077  pathnode->parallel_aware = false;
2078  pathnode->parallel_safe = rel->consider_parallel;
2079  pathnode->parallel_workers = 0;
2080  pathnode->pathkeys = NIL; /* result is always unordered */
2081 
2082  /* Cost is the same as for a regular CTE scan */
2083  cost_ctescan(pathnode, root, rel, pathnode->param_info);
2084 
2085  return pathnode;
2086 }
2087 
2088 /*
2089  * create_foreignscan_path
2090  * Creates a path corresponding to a scan of a foreign base table,
2091  * returning the pathnode.
2092  *
2093  * This function is never called from core Postgres; rather, it's expected
2094  * to be called by the GetForeignPaths function of a foreign data wrapper.
2095  * We make the FDW supply all fields of the path, since we do not have any way
2096  * to calculate them in core. However, there is a usually-sane default for
2097  * the pathtarget (rel->reltarget), so we let a NULL for "target" select that.
2098  */
2099 ForeignPath *
2101  PathTarget *target,
2102  double rows, Cost startup_cost, Cost total_cost,
2103  List *pathkeys,
2104  Relids required_outer,
2105  Path *fdw_outerpath,
2106  List *fdw_private)
2107 {
2108  ForeignPath *pathnode = makeNode(ForeignPath);
2109 
2110  /* Historically some FDWs were confused about when to use this */
2111  Assert(IS_SIMPLE_REL(rel));
2112 
2113  pathnode->path.pathtype = T_ForeignScan;
2114  pathnode->path.parent = rel;
2115  pathnode->path.pathtarget = target ? target : rel->reltarget;
2116  pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
2117  required_outer);
2118  pathnode->path.parallel_aware = false;
2119  pathnode->path.parallel_safe = rel->consider_parallel;
2120  pathnode->path.parallel_workers = 0;
2121  pathnode->path.rows = rows;
2122  pathnode->path.startup_cost = startup_cost;
2123  pathnode->path.total_cost = total_cost;
2124  pathnode->path.pathkeys = pathkeys;
2125 
2126  pathnode->fdw_outerpath = fdw_outerpath;
2127  pathnode->fdw_private = fdw_private;
2128 
2129  return pathnode;
2130 }
2131 
2132 /*
2133  * create_foreign_join_path
2134  * Creates a path corresponding to a scan of a foreign join,
2135  * returning the pathnode.
2136  *
2137  * This function is never called from core Postgres; rather, it's expected
2138  * to be called by the GetForeignJoinPaths function of a foreign data wrapper.
2139  * We make the FDW supply all fields of the path, since we do not have any way
2140  * to calculate them in core. However, there is a usually-sane default for
2141  * the pathtarget (rel->reltarget), so we let a NULL for "target" select that.
2142  */
2143 ForeignPath *
2145  PathTarget *target,
2146  double rows, Cost startup_cost, Cost total_cost,
2147  List *pathkeys,
2148  Relids required_outer,
2149  Path *fdw_outerpath,
2150  List *fdw_private)
2151 {
2152  ForeignPath *pathnode = makeNode(ForeignPath);
2153 
2154  /*
2155  * We should use get_joinrel_parampathinfo to handle parameterized paths,
2156  * but the API of this function doesn't support it, and existing
2157  * extensions aren't yet trying to build such paths anyway. For the
2158  * moment just throw an error if someone tries it; eventually we should
2159  * revisit this.
2160  */
2161  if (!bms_is_empty(required_outer) || !bms_is_empty(rel->lateral_relids))
2162  elog(ERROR, "parameterized foreign joins are not supported yet");
2163 
2164  pathnode->path.pathtype = T_ForeignScan;
2165  pathnode->path.parent = rel;
2166  pathnode->path.pathtarget = target ? target : rel->reltarget;
2167  pathnode->path.param_info = NULL; /* XXX see above */
2168  pathnode->path.parallel_aware = false;
2169  pathnode->path.parallel_safe = rel->consider_parallel;
2170  pathnode->path.parallel_workers = 0;
2171  pathnode->path.rows = rows;
2172  pathnode->path.startup_cost = startup_cost;
2173  pathnode->path.total_cost = total_cost;
2174  pathnode->path.pathkeys = pathkeys;
2175 
2176  pathnode->fdw_outerpath = fdw_outerpath;
2177  pathnode->fdw_private = fdw_private;
2178 
2179  return pathnode;
2180 }
2181 
2182 /*
2183  * create_foreign_upper_path
2184  * Creates a path corresponding to an upper relation that's computed
2185  * directly by an FDW, returning the pathnode.
2186  *
2187  * This function is never called from core Postgres; rather, it's expected to
2188  * be called by the GetForeignUpperPaths function of a foreign data wrapper.
2189  * We make the FDW supply all fields of the path, since we do not have any way
2190  * to calculate them in core. However, there is a usually-sane default for
2191  * the pathtarget (rel->reltarget), so we let a NULL for "target" select that.
2192  */
2193 ForeignPath *
2195  PathTarget *target,
2196  double rows, Cost startup_cost, Cost total_cost,
2197  List *pathkeys,
2198  Path *fdw_outerpath,
2199  List *fdw_private)
2200 {
2201  ForeignPath *pathnode = makeNode(ForeignPath);
2202 
2203  /*
2204  * Upper relations should never have any lateral references, since joining
2205  * is complete.
2206  */
2208 
2209  pathnode->path.pathtype = T_ForeignScan;
2210  pathnode->path.parent = rel;
2211  pathnode->path.pathtarget = target ? target : rel->reltarget;
2212  pathnode->path.param_info = NULL;
2213  pathnode->path.parallel_aware = false;
2214  pathnode->path.parallel_safe = rel->consider_parallel;
2215  pathnode->path.parallel_workers = 0;
2216  pathnode->path.rows = rows;
2217  pathnode->path.startup_cost = startup_cost;
2218  pathnode->path.total_cost = total_cost;
2219  pathnode->path.pathkeys = pathkeys;
2220 
2221  pathnode->fdw_outerpath = fdw_outerpath;
2222  pathnode->fdw_private = fdw_private;
2223 
2224  return pathnode;
2225 }
2226 
2227 /*
2228  * calc_nestloop_required_outer
2229  * Compute the required_outer set for a nestloop join path
2230  *
2231  * Note: result must not share storage with either input
2232  */
2233 Relids
2235  Relids outer_paramrels,
2236  Relids innerrelids,
2237  Relids inner_paramrels)
2238 {
2239  Relids required_outer;
2240 
2241  /* inner_path can require rels from outer path, but not vice versa */
2242  Assert(!bms_overlap(outer_paramrels, innerrelids));
2243  /* easy case if inner path is not parameterized */
2244  if (!inner_paramrels)
2245  return bms_copy(outer_paramrels);
2246  /* else, form the union ... */
2247  required_outer = bms_union(outer_paramrels, inner_paramrels);
2248  /* ... and remove any mention of now-satisfied outer rels */
2249  required_outer = bms_del_members(required_outer,
2250  outerrelids);
2251  /* maintain invariant that required_outer is exactly NULL if empty */
2252  if (bms_is_empty(required_outer))
2253  {
2254  bms_free(required_outer);
2255  required_outer = NULL;
2256  }
2257  return required_outer;
2258 }
2259 
2260 /*
2261  * calc_non_nestloop_required_outer
2262  * Compute the required_outer set for a merge or hash join path
2263  *
2264  * Note: result must not share storage with either input
2265  */
2266 Relids
2267 calc_non_nestloop_required_outer(Path *outer_path, Path *inner_path)
2268 {
2269  Relids outer_paramrels = PATH_REQ_OUTER(outer_path);
2270  Relids inner_paramrels = PATH_REQ_OUTER(inner_path);
2271  Relids required_outer;
2272 
2273  /* neither path can require rels from the other */
2274  Assert(!bms_overlap(outer_paramrels, inner_path->parent->relids));
2275  Assert(!bms_overlap(inner_paramrels, outer_path->parent->relids));
2276  /* form the union ... */
2277  required_outer = bms_union(outer_paramrels, inner_paramrels);
2278  /* we do not need an explicit test for empty; bms_union gets it right */
2279  return required_outer;
2280 }
2281 
2282 /*
2283  * create_nestloop_path
2284  * Creates a pathnode corresponding to a nestloop join between two
2285  * relations.
2286  *
2287  * 'joinrel' is the join relation.
2288  * 'jointype' is the type of join required
2289  * 'workspace' is the result from initial_cost_nestloop
2290  * 'extra' contains various information about the join
2291  * 'outer_path' is the outer path
2292  * 'inner_path' is the inner path
2293  * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
2294  * 'pathkeys' are the path keys of the new join path
2295  * 'required_outer' is the set of required outer rels
2296  *
2297  * Returns the resulting path node.
2298  */
2299 NestPath *
2301  RelOptInfo *joinrel,
2302  JoinType jointype,
2303  JoinCostWorkspace *workspace,
2304  JoinPathExtraData *extra,
2305  Path *outer_path,
2306  Path *inner_path,
2307  List *restrict_clauses,
2308  List *pathkeys,
2309  Relids required_outer)
2310 {
2311  NestPath *pathnode = makeNode(NestPath);
2312  Relids inner_req_outer = PATH_REQ_OUTER(inner_path);
2313 
2314  /*
2315  * If the inner path is parameterized by the outer, we must drop any
2316  * restrict_clauses that are due to be moved into the inner path. We have
2317  * to do this now, rather than postpone the work till createplan time,
2318  * because the restrict_clauses list can affect the size and cost
2319  * estimates for this path.
2320  */
2321  if (bms_overlap(inner_req_outer, outer_path->parent->relids))
2322  {
2323  Relids inner_and_outer = bms_union(inner_path->parent->relids,
2324  inner_req_outer);
2325  List *jclauses = NIL;
2326  ListCell *lc;
2327 
2328  foreach(lc, restrict_clauses)
2329  {
2330  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2331 
2332  if (!join_clause_is_movable_into(rinfo,
2333  inner_path->parent->relids,
2334  inner_and_outer))
2335  jclauses = lappend(jclauses, rinfo);
2336  }
2337  restrict_clauses = jclauses;
2338  }
2339 
2340  pathnode->path.pathtype = T_NestLoop;
2341  pathnode->path.parent = joinrel;
2342  pathnode->path.pathtarget = joinrel->reltarget;
2343  pathnode->path.param_info =
2345  joinrel,
2346  outer_path,
2347  inner_path,
2348  extra->sjinfo,
2349  required_outer,
2350  &restrict_clauses);
2351  pathnode->path.parallel_aware = false;
2352  pathnode->path.parallel_safe = joinrel->consider_parallel &&
2353  outer_path->parallel_safe && inner_path->parallel_safe;
2354  /* This is a foolish way to estimate parallel_workers, but for now... */
2355  pathnode->path.parallel_workers = outer_path->parallel_workers;
2356  pathnode->path.pathkeys = pathkeys;
2357  pathnode->jointype = jointype;
2358  pathnode->inner_unique = extra->inner_unique;
2359  pathnode->outerjoinpath = outer_path;
2360  pathnode->innerjoinpath = inner_path;
2361  pathnode->joinrestrictinfo = restrict_clauses;
2362 
2363  final_cost_nestloop(root, pathnode, workspace, extra);
2364 
2365  return pathnode;
2366 }
2367 
2368 /*
2369  * create_mergejoin_path
2370  * Creates a pathnode corresponding to a mergejoin join between
2371  * two relations
2372  *
2373  * 'joinrel' is the join relation
2374  * 'jointype' is the type of join required
2375  * 'workspace' is the result from initial_cost_mergejoin
2376  * 'extra' contains various information about the join
2377  * 'outer_path' is the outer path
2378  * 'inner_path' is the inner path
2379  * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
2380  * 'pathkeys' are the path keys of the new join path
2381  * 'required_outer' is the set of required outer rels
2382  * 'mergeclauses' are the RestrictInfo nodes to use as merge clauses
2383  * (this should be a subset of the restrict_clauses list)
2384  * 'outersortkeys' are the sort varkeys for the outer relation
2385  * 'innersortkeys' are the sort varkeys for the inner relation
2386  */
2387 MergePath *
2389  RelOptInfo *joinrel,
2390  JoinType jointype,
2391  JoinCostWorkspace *workspace,
2392  JoinPathExtraData *extra,
2393  Path *outer_path,
2394  Path *inner_path,
2395  List *restrict_clauses,
2396  List *pathkeys,
2397  Relids required_outer,
2398  List *mergeclauses,
2399  List *outersortkeys,
2400  List *innersortkeys)
2401 {
2402  MergePath *pathnode = makeNode(MergePath);
2403 
2404  pathnode->jpath.path.pathtype = T_MergeJoin;
2405  pathnode->jpath.path.parent = joinrel;
2406  pathnode->jpath.path.pathtarget = joinrel->reltarget;
2407  pathnode->jpath.path.param_info =
2409  joinrel,
2410  outer_path,
2411  inner_path,
2412  extra->sjinfo,
2413  required_outer,
2414  &restrict_clauses);
2415  pathnode->jpath.path.parallel_aware = false;
2416  pathnode->jpath.path.parallel_safe = joinrel->consider_parallel &&
2417  outer_path->parallel_safe && inner_path->parallel_safe;
2418  /* This is a foolish way to estimate parallel_workers, but for now... */
2419  pathnode->jpath.path.parallel_workers = outer_path->parallel_workers;
2420  pathnode->jpath.path.pathkeys = pathkeys;
2421  pathnode->jpath.jointype = jointype;
2422  pathnode->jpath.inner_unique = extra->inner_unique;
2423  pathnode->jpath.outerjoinpath = outer_path;
2424  pathnode->jpath.innerjoinpath = inner_path;
2425  pathnode->jpath.joinrestrictinfo = restrict_clauses;
2426  pathnode->path_mergeclauses = mergeclauses;
2427  pathnode->outersortkeys = outersortkeys;
2428  pathnode->innersortkeys = innersortkeys;
2429  /* pathnode->skip_mark_restore will be set by final_cost_mergejoin */
2430  /* pathnode->materialize_inner will be set by final_cost_mergejoin */
2431 
2432  final_cost_mergejoin(root, pathnode, workspace, extra);
2433 
2434  return pathnode;
2435 }
2436 
2437 /*
2438  * create_hashjoin_path
2439  * Creates a pathnode corresponding to a hash join between two relations.
2440  *
2441  * 'joinrel' is the join relation
2442  * 'jointype' is the type of join required
2443  * 'workspace' is the result from initial_cost_hashjoin
2444  * 'extra' contains various information about the join
2445  * 'outer_path' is the cheapest outer path
2446  * 'inner_path' is the cheapest inner path
2447  * 'parallel_hash' to select Parallel Hash of inner path (shared hash table)
2448  * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
2449  * 'required_outer' is the set of required outer rels
2450  * 'hashclauses' are the RestrictInfo nodes to use as hash clauses
2451  * (this should be a subset of the restrict_clauses list)
2452  */
2453 HashPath *
2455  RelOptInfo *joinrel,
2456  JoinType jointype,
2457  JoinCostWorkspace *workspace,
2458  JoinPathExtraData *extra,
2459  Path *outer_path,
2460  Path *inner_path,
2461  bool parallel_hash,
2462  List *restrict_clauses,
2463  Relids required_outer,
2464  List *hashclauses)
2465 {
2466  HashPath *pathnode = makeNode(HashPath);
2467 
2468  pathnode->jpath.path.pathtype = T_HashJoin;
2469  pathnode->jpath.path.parent = joinrel;
2470  pathnode->jpath.path.pathtarget = joinrel->reltarget;
2471  pathnode->jpath.path.param_info =
2473  joinrel,
2474  outer_path,
2475  inner_path,
2476  extra->sjinfo,
2477  required_outer,
2478  &restrict_clauses);
2479  pathnode->jpath.path.parallel_aware =
2480  joinrel->consider_parallel && parallel_hash;
2481  pathnode->jpath.path.parallel_safe = joinrel->consider_parallel &&
2482  outer_path->parallel_safe && inner_path->parallel_safe;
2483  /* This is a foolish way to estimate parallel_workers, but for now... */
2484  pathnode->jpath.path.parallel_workers = outer_path->parallel_workers;
2485 
2486  /*
2487  * A hashjoin never has pathkeys, since its output ordering is
2488  * unpredictable due to possible batching. XXX If the inner relation is
2489  * small enough, we could instruct the executor that it must not batch,
2490  * and then we could assume that the output inherits the outer relation's
2491  * ordering, which might save a sort step. However there is considerable
2492  * downside if our estimate of the inner relation size is badly off. For
2493  * the moment we don't risk it. (Note also that if we wanted to take this
2494  * seriously, joinpath.c would have to consider many more paths for the
2495  * outer rel than it does now.)
2496  */
2497  pathnode->jpath.path.pathkeys = NIL;
2498  pathnode->jpath.jointype = jointype;
2499  pathnode->jpath.inner_unique = extra->inner_unique;
2500  pathnode->jpath.outerjoinpath = outer_path;
2501  pathnode->jpath.innerjoinpath = inner_path;
2502  pathnode->jpath.joinrestrictinfo = restrict_clauses;
2503  pathnode->path_hashclauses = hashclauses;
2504  /* final_cost_hashjoin will fill in pathnode->num_batches */
2505 
2506  final_cost_hashjoin(root, pathnode, workspace, extra);
2507 
2508  return pathnode;
2509 }
2510 
2511 /*
2512  * create_projection_path
2513  * Creates a pathnode that represents performing a projection.
2514  *
2515  * 'rel' is the parent relation associated with the result
2516  * 'subpath' is the path representing the source of data
2517  * 'target' is the PathTarget to be computed
2518  */
2521  RelOptInfo *rel,
2522  Path *subpath,
2523  PathTarget *target)
2524 {
2525  ProjectionPath *pathnode = makeNode(ProjectionPath);
2526  PathTarget *oldtarget = subpath->pathtarget;
2527 
2528  pathnode->path.pathtype = T_Result;
2529  pathnode->path.parent = rel;
2530  pathnode->path.pathtarget = target;
2531  /* For now, assume we are above any joins, so no parameterization */
2532  pathnode->path.param_info = NULL;
2533  pathnode->path.parallel_aware = false;
2534  pathnode->path.parallel_safe = rel->consider_parallel &&
2535  subpath->parallel_safe &&
2536  is_parallel_safe(root, (Node *) target->exprs);
2537  pathnode->path.parallel_workers = subpath->parallel_workers;
2538  /* Projection does not change the sort order */
2539  pathnode->path.pathkeys = subpath->pathkeys;
2540 
2541  pathnode->subpath = subpath;
2542 
2543  /*
2544  * We might not need a separate Result node. If the input plan node type
2545  * can project, we can just tell it to project something else. Or, if it
2546  * can't project but the desired target has the same expression list as
2547  * what the input will produce anyway, we can still give it the desired
2548  * tlist (possibly changing its ressortgroupref labels, but nothing else).
2549  * Note: in the latter case, create_projection_plan has to recheck our
2550  * conclusion; see comments therein.
2551  */
2552  if (is_projection_capable_path(subpath) ||
2553  equal(oldtarget->exprs, target->exprs))
2554  {
2555  /* No separate Result node needed */
2556  pathnode->dummypp = true;
2557 
2558  /*
2559  * Set cost of plan as subpath's cost, adjusted for tlist replacement.
2560  */
2561  pathnode->path.rows = subpath->rows;
2562  pathnode->path.startup_cost = subpath->startup_cost +
2563  (target->cost.startup - oldtarget->cost.startup);
2564  pathnode->path.total_cost = subpath->total_cost +
2565  (target->cost.startup - oldtarget->cost.startup) +
2566  (target->cost.per_tuple - oldtarget->cost.per_tuple) * subpath->rows;
2567  }
2568  else
2569  {
2570  /* We really do need the Result node */
2571  pathnode->dummypp = false;
2572 
2573  /*
2574  * The Result node's cost is cpu_tuple_cost per row, plus the cost of
2575  * evaluating the tlist. There is no qual to worry about.
2576  */
2577  pathnode->path.rows = subpath->rows;
2578  pathnode->path.startup_cost = subpath->startup_cost +
2579  target->cost.startup;
2580  pathnode->path.total_cost = subpath->total_cost +
2581  target->cost.startup +
2582  (cpu_tuple_cost + target->cost.per_tuple) * subpath->rows;
2583  }
2584 
2585  return pathnode;
2586 }
2587 
2588 /*
2589  * apply_projection_to_path
2590  * Add a projection step, or just apply the target directly to given path.
2591  *
2592  * This has the same net effect as create_projection_path(), except that if
2593  * a separate Result plan node isn't needed, we just replace the given path's
2594  * pathtarget with the desired one. This must be used only when the caller
2595  * knows that the given path isn't referenced elsewhere and so can be modified
2596  * in-place.
2597  *
2598  * If the input path is a GatherPath or GatherMergePath, we try to push the
2599  * new target down to its input as well; this is a yet more invasive
2600  * modification of the input path, which create_projection_path() can't do.
2601  *
2602  * Note that we mustn't change the source path's parent link; so when it is
2603  * add_path'd to "rel" things will be a bit inconsistent. So far that has
2604  * not caused any trouble.
2605  *
2606  * 'rel' is the parent relation associated with the result
2607  * 'path' is the path representing the source of data
2608  * 'target' is the PathTarget to be computed
2609  */
2610 Path *
2612  RelOptInfo *rel,
2613  Path *path,
2614  PathTarget *target)
2615 {
2616  QualCost oldcost;
2617 
2618  /*
2619  * If given path can't project, we might need a Result node, so make a
2620  * separate ProjectionPath.
2621  */
2622  if (!is_projection_capable_path(path))
2623  return (Path *) create_projection_path(root, rel, path, target);
2624 
2625  /*
2626  * We can just jam the desired tlist into the existing path, being sure to
2627  * update its cost estimates appropriately.
2628  */
2629  oldcost = path->pathtarget->cost;
2630  path->pathtarget = target;
2631 
2632  path->startup_cost += target->cost.startup - oldcost.startup;
2633  path->total_cost += target->cost.startup - oldcost.startup +
2634  (target->cost.per_tuple - oldcost.per_tuple) * path->rows;
2635 
2636  /*
2637  * If the path happens to be a Gather or GatherMerge path, we'd like to
2638  * arrange for the subpath to return the required target list so that
2639  * workers can help project. But if there is something that is not
2640  * parallel-safe in the target expressions, then we can't.
2641  */
2642  if ((IsA(path, GatherPath) || IsA(path, GatherMergePath)) &&
2643  is_parallel_safe(root, (Node *) target->exprs))
2644  {
2645  /*
2646  * We always use create_projection_path here, even if the subpath is
2647  * projection-capable, so as to avoid modifying the subpath in place.
2648  * It seems unlikely at present that there could be any other
2649  * references to the subpath, but better safe than sorry.
2650  *
2651  * Note that we don't change the parallel path's cost estimates; it
2652  * might be appropriate to do so, to reflect the fact that the bulk of
2653  * the target evaluation will happen in workers.
2654  */
2655  if (IsA(path, GatherPath))
2656  {
2657  GatherPath *gpath = (GatherPath *) path;
2658 
2659  gpath->subpath = (Path *)
2661  gpath->subpath->parent,
2662  gpath->subpath,
2663  target);
2664  }
2665  else
2666  {
2667  GatherMergePath *gmpath = (GatherMergePath *) path;
2668 
2669  gmpath->subpath = (Path *)
2671  gmpath->subpath->parent,
2672  gmpath->subpath,
2673  target);
2674  }
2675  }
2676  else if (path->parallel_safe &&
2677  !is_parallel_safe(root, (Node *) target->exprs))
2678  {
2679  /*
2680  * We're inserting a parallel-restricted target list into a path
2681  * currently marked parallel-safe, so we have to mark it as no longer
2682  * safe.
2683  */
2684  path->parallel_safe = false;
2685  }
2686 
2687  return path;
2688 }
2689 
2690 /*
2691  * create_set_projection_path
2692  * Creates a pathnode that represents performing a projection that
2693  * includes set-returning functions.
2694  *
2695  * 'rel' is the parent relation associated with the result
2696  * 'subpath' is the path representing the source of data
2697  * 'target' is the PathTarget to be computed
2698  */
2701  RelOptInfo *rel,
2702  Path *subpath,
2703  PathTarget *target)
2704 {
2705  ProjectSetPath *pathnode = makeNode(ProjectSetPath);
2706  double tlist_rows;
2707  ListCell *lc;
2708 
2709  pathnode->path.pathtype = T_ProjectSet;
2710  pathnode->path.parent = rel;
2711  pathnode->path.pathtarget = target;
2712  /* For now, assume we are above any joins, so no parameterization */
2713  pathnode->path.param_info = NULL;
2714  pathnode->path.parallel_aware = false;
2715  pathnode->path.parallel_safe = rel->consider_parallel &&
2716  subpath->parallel_safe &&
2717  is_parallel_safe(root, (Node *) target->exprs);
2718  pathnode->path.parallel_workers = subpath->parallel_workers;
2719  /* Projection does not change the sort order XXX? */
2720  pathnode->path.pathkeys = subpath->pathkeys;
2721 
2722  pathnode->subpath = subpath;
2723 
2724  /*
2725  * Estimate number of rows produced by SRFs for each row of input; if
2726  * there's more than one in this node, use the maximum.
2727  */
2728  tlist_rows = 1;
2729  foreach(lc, target->exprs)
2730  {
2731  Node *node = (Node *) lfirst(lc);
2732  double itemrows;
2733 
2734  itemrows = expression_returns_set_rows(root, node);
2735  if (tlist_rows < itemrows)
2736  tlist_rows = itemrows;
2737  }
2738 
2739  /*
2740  * In addition to the cost of evaluating the tlist, charge cpu_tuple_cost
2741  * per input row, and half of cpu_tuple_cost for each added output row.
2742  * This is slightly bizarre maybe, but it's what 9.6 did; we may revisit
2743  * this estimate later.
2744  */
2745  pathnode->path.rows = subpath->rows * tlist_rows;
2746  pathnode->path.startup_cost = subpath->startup_cost +
2747  target->cost.startup;
2748  pathnode->path.total_cost = subpath->total_cost +
2749  target->cost.startup +
2750  (cpu_tuple_cost + target->cost.per_tuple) * subpath->rows +
2751  (pathnode->path.rows - subpath->rows) * cpu_tuple_cost / 2;
2752 
2753  return pathnode;
2754 }
2755 
2756 /*
2757  * create_incremental_sort_path
2758  * Creates a pathnode that represents performing an incremental sort.
2759  *
2760  * 'rel' is the parent relation associated with the result
2761  * 'subpath' is the path representing the source of data
2762  * 'pathkeys' represents the desired sort order
2763  * 'presorted_keys' is the number of keys by which the input path is
2764  * already sorted
2765  * 'limit_tuples' is the estimated bound on the number of output tuples,
2766  * or -1 if no LIMIT or couldn't estimate
2767  */
2768 SortPath *
2770  RelOptInfo *rel,
2771  Path *subpath,
2772  List *pathkeys,
2773  int presorted_keys,
2774  double limit_tuples)
2775 {
2777  SortPath *pathnode = &sort->spath;
2778 
2779  pathnode->path.pathtype = T_IncrementalSort;
2780  pathnode->path.parent = rel;
2781  /* Sort doesn't project, so use source path's pathtarget */
2782  pathnode->path.pathtarget = subpath->pathtarget;
2783  /* For now, assume we are above any joins, so no parameterization */
2784  pathnode->path.param_info = NULL;
2785  pathnode->path.parallel_aware = false;
2786  pathnode->path.parallel_safe = rel->consider_parallel &&
2787  subpath->parallel_safe;
2788  pathnode->path.parallel_workers = subpath->parallel_workers;
2789  pathnode->path.pathkeys = pathkeys;
2790 
2791  pathnode->subpath = subpath;
2792 
2793  cost_incremental_sort(&pathnode->path,
2794  root, pathkeys, presorted_keys,
2795  subpath->startup_cost,
2796  subpath->total_cost,
2797  subpath->rows,
2798  subpath->pathtarget->width,
2799  0.0, /* XXX comparison_cost shouldn't be 0? */
2800  work_mem, limit_tuples);
2801 
2802  sort->nPresortedCols = presorted_keys;
2803 
2804  return pathnode;
2805 }
2806 
2807 /*
2808  * create_sort_path
2809  * Creates a pathnode that represents performing an explicit sort.
2810  *
2811  * 'rel' is the parent relation associated with the result
2812  * 'subpath' is the path representing the source of data
2813  * 'pathkeys' represents the desired sort order
2814  * 'limit_tuples' is the estimated bound on the number of output tuples,
2815  * or -1 if no LIMIT or couldn't estimate
2816  */
2817 SortPath *
2819  RelOptInfo *rel,
2820  Path *subpath,
2821  List *pathkeys,
2822  double limit_tuples)
2823 {
2824  SortPath *pathnode = makeNode(SortPath);
2825 
2826  pathnode->path.pathtype = T_Sort;
2827  pathnode->path.parent = rel;
2828  /* Sort doesn't project, so use source path's pathtarget */
2829  pathnode->path.pathtarget = subpath->pathtarget;
2830  /* For now, assume we are above any joins, so no parameterization */
2831  pathnode->path.param_info = NULL;
2832  pathnode->path.parallel_aware = false;
2833  pathnode->path.parallel_safe = rel->consider_parallel &&
2834  subpath->parallel_safe;
2835  pathnode->path.parallel_workers = subpath->parallel_workers;
2836  pathnode->path.pathkeys = pathkeys;
2837 
2838  pathnode->subpath = subpath;
2839 
2840  cost_sort(&pathnode->path, root, pathkeys,
2841  subpath->total_cost,
2842  subpath->rows,
2843  subpath->pathtarget->width,
2844  0.0, /* XXX comparison_cost shouldn't be 0? */
2845  work_mem, limit_tuples);
2846 
2847  return pathnode;
2848 }
2849 
2850 /*
2851  * create_group_path
2852  * Creates a pathnode that represents performing grouping of presorted input
2853  *
2854  * 'rel' is the parent relation associated with the result
2855  * 'subpath' is the path representing the source of data
2856  * 'target' is the PathTarget to be computed
2857  * 'groupClause' is a list of SortGroupClause's representing the grouping
2858  * 'qual' is the HAVING quals if any
2859  * 'numGroups' is the estimated number of groups
2860  */
2861 GroupPath *
2863  RelOptInfo *rel,
2864  Path *subpath,
2865  List *groupClause,
2866  List *qual,
2867  double numGroups)
2868 {
2869  GroupPath *pathnode = makeNode(GroupPath);
2870  PathTarget *target = rel->reltarget;
2871 
2872  pathnode->path.pathtype = T_Group;
2873  pathnode->path.parent = rel;
2874  pathnode->path.pathtarget = target;
2875  /* For now, assume we are above any joins, so no parameterization */
2876  pathnode->path.param_info = NULL;
2877  pathnode->path.parallel_aware = false;
2878  pathnode->path.parallel_safe = rel->consider_parallel &&
2879  subpath->parallel_safe;
2880  pathnode->path.parallel_workers = subpath->parallel_workers;
2881  /* Group doesn't change sort ordering */
2882  pathnode->path.pathkeys = subpath->pathkeys;
2883 
2884  pathnode->subpath = subpath;
2885 
2886  pathnode->groupClause = groupClause;
2887  pathnode->qual = qual;
2888 
2889  cost_group(&pathnode->path, root,
2890  list_length(groupClause),
2891  numGroups,
2892  qual,
2893  subpath->startup_cost, subpath->total_cost,
2894  subpath->rows);
2895 
2896  /* add tlist eval cost for each output row */
2897  pathnode->path.startup_cost += target->cost.startup;
2898  pathnode->path.total_cost += target->cost.startup +
2899  target->cost.per_tuple * pathnode->path.rows;
2900 
2901  return pathnode;
2902 }
2903 
2904 /*
2905  * create_upper_unique_path
2906  * Creates a pathnode that represents performing an explicit Unique step
2907  * on presorted input.
2908  *
2909  * This produces a Unique plan node, but the use-case is so different from
2910  * create_unique_path that it doesn't seem worth trying to merge the two.
2911  *
2912  * 'rel' is the parent relation associated with the result
2913  * 'subpath' is the path representing the source of data
2914  * 'numCols' is the number of grouping columns
2915  * 'numGroups' is the estimated number of groups
2916  *
2917  * The input path must be sorted on the grouping columns, plus possibly
2918  * additional columns; so the first numCols pathkeys are the grouping columns
2919  */
2922  RelOptInfo *rel,
2923  Path *subpath,
2924  int numCols,
2925  double numGroups)
2926 {
2928 
2929  pathnode->path.pathtype = T_Unique;
2930  pathnode->path.parent = rel;
2931  /* Unique doesn't project, so use source path's pathtarget */
2932  pathnode->path.pathtarget = subpath->pathtarget;
2933  /* For now, assume we are above any joins, so no parameterization */
2934  pathnode->path.param_info = NULL;
2935  pathnode->path.parallel_aware = false;
2936  pathnode->path.parallel_safe = rel->consider_parallel &&
2937  subpath->parallel_safe;
2938  pathnode->path.parallel_workers = subpath->parallel_workers;
2939  /* Unique doesn't change the input ordering */
2940  pathnode->path.pathkeys = subpath->pathkeys;
2941 
2942  pathnode->subpath = subpath;
2943  pathnode->numkeys = numCols;
2944 
2945  /*
2946  * Charge one cpu_operator_cost per comparison per input tuple. We assume
2947  * all columns get compared at most of the tuples. (XXX probably this is
2948  * an overestimate.)
2949  */
2950  pathnode->path.startup_cost = subpath->startup_cost;
2951  pathnode->path.total_cost = subpath->total_cost +
2952  cpu_operator_cost * subpath->rows * numCols;
2953  pathnode->path.rows = numGroups;
2954 
2955  return pathnode;
2956 }
2957 
2958 /*
2959  * create_agg_path
2960  * Creates a pathnode that represents performing aggregation/grouping
2961  *
2962  * 'rel' is the parent relation associated with the result
2963  * 'subpath' is the path representing the source of data
2964  * 'target' is the PathTarget to be computed
2965  * 'aggstrategy' is the Agg node's basic implementation strategy
2966  * 'aggsplit' is the Agg node's aggregate-splitting mode
2967  * 'groupClause' is a list of SortGroupClause's representing the grouping
2968  * 'qual' is the HAVING quals if any
2969  * 'aggcosts' contains cost info about the aggregate functions to be computed
2970  * 'numGroups' is the estimated number of groups (1 if not grouping)
2971  */
2972 AggPath *
2974  RelOptInfo *rel,
2975  Path *subpath,
2976  PathTarget *target,
2977  AggStrategy aggstrategy,
2978  AggSplit aggsplit,
2979  List *groupClause,
2980  List *qual,
2981  const AggClauseCosts *aggcosts,
2982  double numGroups)
2983 {
2984  AggPath *pathnode = makeNode(AggPath);
2985 
2986  pathnode->path.pathtype = T_Agg;
2987  pathnode->path.parent = rel;
2988  pathnode->path.pathtarget = target;
2989  /* For now, assume we are above any joins, so no parameterization */
2990  pathnode->path.param_info = NULL;
2991  pathnode->path.parallel_aware = false;
2992  pathnode->path.parallel_safe = rel->consider_parallel &&
2993  subpath->parallel_safe;
2994  pathnode->path.parallel_workers = subpath->parallel_workers;
2995  if (aggstrategy == AGG_SORTED)
2996  pathnode->path.pathkeys = subpath->pathkeys; /* preserves order */
2997  else
2998  pathnode->path.pathkeys = NIL; /* output is unordered */
2999  pathnode->subpath = subpath;
3000 
3001  pathnode->aggstrategy = aggstrategy;
3002  pathnode->aggsplit = aggsplit;
3003  pathnode->numGroups = numGroups;
3004  pathnode->transitionSpace = aggcosts ? aggcosts->transitionSpace : 0;
3005  pathnode->groupClause = groupClause;
3006  pathnode->qual = qual;
3007 
3008  cost_agg(&pathnode->path, root,
3009  aggstrategy, aggcosts,
3010  list_length(groupClause), numGroups,
3011  qual,
3012  subpath->startup_cost, subpath->total_cost,
3013  subpath->rows, subpath->pathtarget->width);
3014 
3015  /* add tlist eval cost for each output row */
3016  pathnode->path.startup_cost += target->cost.startup;
3017  pathnode->path.total_cost += target->cost.startup +
3018  target->cost.per_tuple * pathnode->path.rows;
3019 
3020  return pathnode;
3021 }
3022 
3023 /*
3024  * create_groupingsets_path
3025  * Creates a pathnode that represents performing GROUPING SETS aggregation
3026  *
3027  * GroupingSetsPath represents sorted grouping with one or more grouping sets.
3028  * The input path's result must be sorted to match the last entry in
3029  * rollup_groupclauses.
3030  *
3031  * 'rel' is the parent relation associated with the result
3032  * 'subpath' is the path representing the source of data
3033  * 'target' is the PathTarget to be computed
3034  * 'having_qual' is the HAVING quals if any
3035  * 'rollups' is a list of RollupData nodes
3036  * 'agg_costs' contains cost info about the aggregate functions to be computed
3037  * 'numGroups' is the estimated total number of groups
3038  */
3041  RelOptInfo *rel,
3042  Path *subpath,
3043  List *having_qual,
3044  AggStrategy aggstrategy,
3045  List *rollups,
3046  const AggClauseCosts *agg_costs,
3047  double numGroups)
3048 {
3050  PathTarget *target = rel->reltarget;
3051  ListCell *lc;
3052  bool is_first = true;
3053  bool is_first_sort = true;
3054 
3055  /* The topmost generated Plan node will be an Agg */
3056  pathnode->path.pathtype = T_Agg;
3057  pathnode->path.parent = rel;
3058  pathnode->path.pathtarget = target;
3059  pathnode->path.param_info = subpath->param_info;
3060  pathnode->path.parallel_aware = false;
3061  pathnode->path.parallel_safe = rel->consider_parallel &&
3062  subpath->parallel_safe;
3063  pathnode->path.parallel_workers = subpath->parallel_workers;
3064  pathnode->subpath = subpath;
3065 
3066  /*
3067  * Simplify callers by downgrading AGG_SORTED to AGG_PLAIN, and AGG_MIXED
3068  * to AGG_HASHED, here if possible.
3069  */
3070  if (aggstrategy == AGG_SORTED &&
3071  list_length(rollups) == 1 &&
3072  ((RollupData *) linitial(rollups))->groupClause == NIL)
3073  aggstrategy = AGG_PLAIN;
3074 
3075  if (aggstrategy == AGG_MIXED &&
3076  list_length(rollups) == 1)
3077  aggstrategy = AGG_HASHED;
3078 
3079  /*
3080  * Output will be in sorted order by group_pathkeys if, and only if, there
3081  * is a single rollup operation on a non-empty list of grouping
3082  * expressions.
3083  */
3084  if (aggstrategy == AGG_SORTED && list_length(rollups) == 1)
3085  pathnode->path.pathkeys = root->group_pathkeys;
3086  else
3087  pathnode->path.pathkeys = NIL;
3088 
3089  pathnode->aggstrategy = aggstrategy;
3090  pathnode->rollups = rollups;
3091  pathnode->qual = having_qual;
3092  pathnode->transitionSpace = agg_costs ? agg_costs->transitionSpace : 0;
3093 
3094  Assert(rollups != NIL);
3095  Assert(aggstrategy != AGG_PLAIN || list_length(rollups) == 1);
3096  Assert(aggstrategy != AGG_MIXED || list_length(rollups) > 1);
3097 
3098  foreach(lc, rollups)
3099  {
3100  RollupData *rollup = lfirst(lc);
3101  List *gsets = rollup->gsets;
3102  int numGroupCols = list_length(linitial(gsets));
3103 
3104  /*
3105  * In AGG_SORTED or AGG_PLAIN mode, the first rollup takes the
3106  * (already-sorted) input, and following ones do their own sort.
3107  *
3108  * In AGG_HASHED mode, there is one rollup for each grouping set.
3109  *
3110  * In AGG_MIXED mode, the first rollups are hashed, the first
3111  * non-hashed one takes the (already-sorted) input, and following ones
3112  * do their own sort.
3113  */
3114  if (is_first)
3115  {
3116  cost_agg(&pathnode->path, root,
3117  aggstrategy,
3118  agg_costs,
3119  numGroupCols,
3120  rollup->numGroups,
3121  having_qual,
3122  subpath->startup_cost,
3123  subpath->total_cost,
3124  subpath->rows,
3125  subpath->pathtarget->width);
3126  is_first = false;
3127  if (!rollup->is_hashed)
3128  is_first_sort = false;
3129  }
3130  else
3131  {
3132  Path sort_path; /* dummy for result of cost_sort */
3133  Path agg_path; /* dummy for result of cost_agg */
3134 
3135  if (rollup->is_hashed || is_first_sort)
3136  {
3137  /*
3138  * Account for cost of aggregation, but don't charge input
3139  * cost again
3140  */
3141  cost_agg(&agg_path, root,
3142  rollup->is_hashed ? AGG_HASHED : AGG_SORTED,
3143  agg_costs,
3144  numGroupCols,
3145  rollup->numGroups,
3146  having_qual,
3147  0.0, 0.0,
3148  subpath->rows,
3149  subpath->pathtarget->width);
3150  if (!rollup->is_hashed)
3151  is_first_sort = false;
3152  }
3153  else
3154  {
3155  /* Account for cost of sort, but don't charge input cost again */
3156  cost_sort(&sort_path, root, NIL,
3157  0.0,
3158  subpath->rows,
3159  subpath->pathtarget->width,
3160  0.0,
3161  work_mem,
3162  -1.0);
3163 
3164  /* Account for cost of aggregation */
3165 
3166  cost_agg(&agg_path, root,
3167  AGG_SORTED,
3168  agg_costs,
3169  numGroupCols,
3170  rollup->numGroups,
3171  having_qual,
3172  sort_path.startup_cost,
3173  sort_path.total_cost,
3174  sort_path.rows,
3175  subpath->pathtarget->width);
3176  }
3177 
3178  pathnode->path.total_cost += agg_path.total_cost;
3179  pathnode->path.rows += agg_path.rows;
3180  }
3181  }
3182 
3183  /* add tlist eval cost for each output row */
3184  pathnode->path.startup_cost += target->cost.startup;
3185  pathnode->path.total_cost += target->cost.startup +
3186  target->cost.per_tuple * pathnode->path.rows;
3187 
3188  return pathnode;
3189 }
3190 
3191 /*
3192  * create_minmaxagg_path
3193  * Creates a pathnode that represents computation of MIN/MAX aggregates
3194  *
3195  * 'rel' is the parent relation associated with the result
3196  * 'target' is the PathTarget to be computed
3197  * 'mmaggregates' is a list of MinMaxAggInfo structs
3198  * 'quals' is the HAVING quals if any
3199  */
3200 MinMaxAggPath *
3202  RelOptInfo *rel,
3203  PathTarget *target,
3204  List *mmaggregates,
3205  List *quals)
3206 {
3207  MinMaxAggPath *pathnode = makeNode(MinMaxAggPath);
3208  Cost initplan_cost;
3209  ListCell *lc;
3210 
3211  /* The topmost generated Plan node will be a Result */
3212  pathnode->path.pathtype = T_Result;
3213  pathnode->path.parent = rel;
3214  pathnode->path.pathtarget = target;
3215  /* For now, assume we are above any joins, so no parameterization */
3216  pathnode->path.param_info = NULL;
3217  pathnode->path.parallel_aware = false;
3218  /* A MinMaxAggPath implies use of subplans, so cannot be parallel-safe */
3219  pathnode->path.parallel_safe = false;
3220  pathnode->path.parallel_workers = 0;
3221  /* Result is one unordered row */
3222  pathnode->path.rows = 1;
3223  pathnode->path.pathkeys = NIL;
3224 
3225  pathnode->mmaggregates = mmaggregates;
3226  pathnode->quals = quals;
3227 
3228  /* Calculate cost of all the initplans ... */
3229  initplan_cost = 0;
3230  foreach(lc, mmaggregates)
3231  {
3232  MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc);
3233 
3234  initplan_cost += mminfo->pathcost;
3235  }
3236 
3237  /* add tlist eval cost for each output row, plus cpu_tuple_cost */
3238  pathnode->path.startup_cost = initplan_cost + target->cost.startup;
3239  pathnode->path.total_cost = initplan_cost + target->cost.startup +
3240  target->cost.per_tuple + cpu_tuple_cost;
3241 
3242  /*
3243  * Add cost of qual, if any --- but we ignore its selectivity, since our
3244  * rowcount estimate should be 1 no matter what the qual is.
3245  */
3246  if (quals)
3247  {
3248  QualCost qual_cost;
3249 
3250  cost_qual_eval(&qual_cost, quals, root);
3251  pathnode->path.startup_cost += qual_cost.startup;
3252  pathnode->path.total_cost += qual_cost.startup + qual_cost.per_tuple;
3253  }
3254 
3255  return pathnode;
3256 }
3257 
3258 /*
3259  * create_windowagg_path
3260  * Creates a pathnode that represents computation of window functions
3261  *
3262  * 'rel' is the parent relation associated with the result
3263  * 'subpath' is the path representing the source of data
3264  * 'target' is the PathTarget to be computed
3265  * 'windowFuncs' is a list of WindowFunc structs
3266  * 'winclause' is a WindowClause that is common to all the WindowFuncs
3267  *
3268  * The input must be sorted according to the WindowClause's PARTITION keys
3269  * plus ORDER BY keys.
3270  */
3271 WindowAggPath *
3273  RelOptInfo *rel,
3274  Path *subpath,
3275  PathTarget *target,
3276  List *windowFuncs,
3277  WindowClause *winclause)
3278 {
3279  WindowAggPath *pathnode = makeNode(WindowAggPath);
3280 
3281  pathnode->path.pathtype = T_WindowAgg;
3282  pathnode->path.parent = rel;
3283  pathnode->path.pathtarget = target;
3284  /* For now, assume we are above any joins, so no parameterization */
3285  pathnode->path.param_info = NULL;
3286  pathnode->path.parallel_aware = false;
3287  pathnode->path.parallel_safe = rel->consider_parallel &&
3288  subpath->parallel_safe;
3289  pathnode->path.parallel_workers = subpath->parallel_workers;
3290  /* WindowAgg preserves the input sort order */
3291  pathnode->path.pathkeys = subpath->pathkeys;
3292 
3293  pathnode->subpath = subpath;
3294  pathnode->winclause = winclause;
3295 
3296  /*
3297  * For costing purposes, assume that there are no redundant partitioning
3298  * or ordering columns; it's not worth the trouble to deal with that
3299  * corner case here. So we just pass the unmodified list lengths to
3300  * cost_windowagg.
3301  */
3302  cost_windowagg(&pathnode->path, root,
3303  windowFuncs,
3304  list_length(winclause->partitionClause),
3305  list_length(winclause->orderClause),
3306  subpath->startup_cost,
3307  subpath->total_cost,
3308  subpath->rows);
3309 
3310  /* add tlist eval cost for each output row */
3311  pathnode->path.startup_cost += target->cost.startup;
3312  pathnode->path.total_cost += target->cost.startup +
3313  target->cost.per_tuple * pathnode->path.rows;
3314 
3315  return pathnode;
3316 }
3317 
3318 /*
3319  * create_setop_path
3320  * Creates a pathnode that represents computation of INTERSECT or EXCEPT
3321  *
3322  * 'rel' is the parent relation associated with the result
3323  * 'subpath' is the path representing the source of data
3324  * 'cmd' is the specific semantics (INTERSECT or EXCEPT, with/without ALL)
3325  * 'strategy' is the implementation strategy (sorted or hashed)
3326  * 'distinctList' is a list of SortGroupClause's representing the grouping
3327  * 'flagColIdx' is the column number where the flag column will be, if any
3328  * 'firstFlag' is the flag value for the first input relation when hashing;
3329  * or -1 when sorting
3330  * 'numGroups' is the estimated number of distinct groups
3331  * 'outputRows' is the estimated number of output rows
3332  */
3333 SetOpPath *
3335  RelOptInfo *rel,
3336  Path *subpath,
3337  SetOpCmd cmd,
3338  SetOpStrategy strategy,
3339  List *distinctList,
3340  AttrNumber flagColIdx,
3341  int firstFlag,
3342  double numGroups,
3343  double outputRows)
3344 {
3345  SetOpPath *pathnode = makeNode(SetOpPath);
3346 
3347  pathnode->path.pathtype = T_SetOp;
3348  pathnode->path.parent = rel;
3349  /* SetOp doesn't project, so use source path's pathtarget */
3350  pathnode->path.pathtarget = subpath->pathtarget;
3351  /* For now, assume we are above any joins, so no parameterization */
3352  pathnode->path.param_info = NULL;
3353  pathnode->path.parallel_aware = false;
3354  pathnode->path.parallel_safe = rel->consider_parallel &&
3355  subpath->parallel_safe;
3356  pathnode->path.parallel_workers = subpath->parallel_workers;
3357  /* SetOp preserves the input sort order if in sort mode */
3358  pathnode->path.pathkeys =
3359  (strategy == SETOP_SORTED) ? subpath->pathkeys : NIL;
3360 
3361  pathnode->subpath = subpath;
3362  pathnode->cmd = cmd;
3363  pathnode->strategy = strategy;
3364  pathnode->distinctList = distinctList;
3365  pathnode->flagColIdx = flagColIdx;
3366  pathnode->firstFlag = firstFlag;
3367  pathnode->numGroups = numGroups;
3368 
3369  /*
3370  * Charge one cpu_operator_cost per comparison per input tuple. We assume
3371  * all columns get compared at most of the tuples.
3372  */
3373  pathnode->path.startup_cost = subpath->startup_cost;
3374  pathnode->path.total_cost = subpath->total_cost +
3375  cpu_operator_cost * subpath->rows * list_length(distinctList);
3376  pathnode->path.rows = outputRows;
3377 
3378  return pathnode;
3379 }
3380 
3381 /*
3382  * create_recursiveunion_path
3383  * Creates a pathnode that represents a recursive UNION node
3384  *
3385  * 'rel' is the parent relation associated with the result
3386  * 'leftpath' is the source of data for the non-recursive term
3387  * 'rightpath' is the source of data for the recursive term
3388  * 'target' is the PathTarget to be computed
3389  * 'distinctList' is a list of SortGroupClause's representing the grouping
3390  * 'wtParam' is the ID of Param representing work table
3391  * 'numGroups' is the estimated number of groups
3392  *
3393  * For recursive UNION ALL, distinctList is empty and numGroups is zero
3394  */
3397  RelOptInfo *rel,
3398  Path *leftpath,
3399  Path *rightpath,
3400  PathTarget *target,
3401  List *distinctList,
3402  int wtParam,
3403  double numGroups)
3404 {
3406 
3407  pathnode->path.pathtype = T_RecursiveUnion;
3408  pathnode->path.parent = rel;
3409  pathnode->path.pathtarget = target;
3410  /* For now, assume we are above any joins, so no parameterization */
3411  pathnode->path.param_info = NULL;
3412  pathnode->path.parallel_aware = false;
3413  pathnode->path.parallel_safe = rel->consider_parallel &&
3414  leftpath->parallel_safe && rightpath->parallel_safe;
3415  /* Foolish, but we'll do it like joins for now: */
3416  pathnode->path.parallel_workers = leftpath->parallel_workers;
3417  /* RecursiveUnion result is always unsorted */
3418  pathnode->path.pathkeys = NIL;
3419 
3420  pathnode->leftpath = leftpath;
3421  pathnode->rightpath = rightpath;
3422  pathnode->distinctList = distinctList;
3423  pathnode->wtParam = wtParam;
3424  pathnode->numGroups = numGroups;
3425 
3426  cost_recursive_union(&pathnode->path, leftpath, rightpath);
3427 
3428  return pathnode;
3429 }
3430 
3431 /*
3432  * create_lockrows_path
3433  * Creates a pathnode that represents acquiring row locks
3434  *
3435  * 'rel' is the parent relation associated with the result
3436  * 'subpath' is the path representing the source of data
3437  * 'rowMarks' is a list of PlanRowMark's
3438  * 'epqParam' is the ID of Param for EvalPlanQual re-eval
3439  */
3440 LockRowsPath *
3442  Path *subpath, List *rowMarks, int epqParam)
3443 {
3444  LockRowsPath *pathnode = makeNode(LockRowsPath);
3445 
3446  pathnode->path.pathtype = T_LockRows;
3447  pathnode->path.parent = rel;
3448  /* LockRows doesn't project, so use source path's pathtarget */
3449  pathnode->path.pathtarget = subpath->pathtarget;
3450  /* For now, assume we are above any joins, so no parameterization */
3451  pathnode->path.param_info = NULL;
3452  pathnode->path.parallel_aware = false;
3453  pathnode->path.parallel_safe = false;
3454  pathnode->path.parallel_workers = 0;
3455  pathnode->path.rows = subpath->rows;
3456 
3457  /*
3458  * The result cannot be assumed sorted, since locking might cause the sort
3459  * key columns to be replaced with new values.
3460  */
3461  pathnode->path.pathkeys = NIL;
3462 
3463  pathnode->subpath = subpath;
3464  pathnode->rowMarks = rowMarks;
3465  pathnode->epqParam = epqParam;
3466 
3467  /*
3468  * We should charge something extra for the costs of row locking and
3469  * possible refetches, but it's hard to say how much. For now, use
3470  * cpu_tuple_cost per row.
3471  */
3472  pathnode->path.startup_cost = subpath->startup_cost;
3473  pathnode->path.total_cost = subpath->total_cost +
3474  cpu_tuple_cost * subpath->rows;
3475 
3476  return pathnode;
3477 }
3478 
3479 /*
3480  * create_modifytable_path
3481  * Creates a pathnode that represents performing INSERT/UPDATE/DELETE mods
3482  *
3483  * 'rel' is the parent relation associated with the result
3484  * 'operation' is the operation type
3485  * 'canSetTag' is true if we set the command tag/es_processed
3486  * 'nominalRelation' is the parent RT index for use of EXPLAIN
3487  * 'rootRelation' is the partitioned table root RT index, or 0 if none
3488  * 'partColsUpdated' is true if any partitioning columns are being updated,
3489  * either from the target relation or a descendent partitioned table.
3490  * 'resultRelations' is an integer list of actual RT indexes of target rel(s)
3491  * 'subpaths' is a list of Path(s) producing source data (one per rel)
3492  * 'subroots' is a list of PlannerInfo structs (one per rel)
3493  * 'withCheckOptionLists' is a list of WCO lists (one per rel)
3494  * 'returningLists' is a list of RETURNING tlists (one per rel)
3495  * 'rowMarks' is a list of PlanRowMarks (non-locking only)
3496  * 'onconflict' is the ON CONFLICT clause, or NULL
3497  * 'epqParam' is the ID of Param for EvalPlanQual re-eval
3498  */
3501  CmdType operation, bool canSetTag,
3502  Index nominalRelation, Index rootRelation,
3503  bool partColsUpdated,
3504  List *resultRelations, List *subpaths,
3505  List *subroots,
3506  List *withCheckOptionLists, List *returningLists,
3507  List *rowMarks, OnConflictExpr *onconflict,
3508  int epqParam)
3509 {
3511  double total_size;
3512  ListCell *lc;
3513 
3514  Assert(list_length(resultRelations) == list_length(subpaths));
3515  Assert(list_length(resultRelations) == list_length(subroots));
3516  Assert(withCheckOptionLists == NIL ||
3517  list_length(resultRelations) == list_length(withCheckOptionLists));
3518  Assert(returningLists == NIL ||
3519  list_length(resultRelations) == list_length(returningLists));
3520 
3521  pathnode->path.pathtype = T_ModifyTable;
3522  pathnode->path.parent = rel;
3523  /* pathtarget is not interesting, just make it minimally valid */
3524  pathnode->path.pathtarget = rel->reltarget;
3525  /* For now, assume we are above any joins, so no parameterization */
3526  pathnode->path.param_info = NULL;
3527  pathnode->path.parallel_aware = false;
3528  pathnode->path.parallel_safe = false;
3529  pathnode->path.parallel_workers = 0;
3530  pathnode->path.pathkeys = NIL;
3531 
3532  /*
3533  * Compute cost & rowcount as sum of subpath costs & rowcounts.
3534  *
3535  * Currently, we don't charge anything extra for the actual table
3536  * modification work, nor for the WITH CHECK OPTIONS or RETURNING
3537  * expressions if any. It would only be window dressing, since
3538  * ModifyTable is always a top-level node and there is no way for the
3539  * costs to change any higher-level planning choices. But we might want
3540  * to make it look better sometime.
3541  */
3542  pathnode->path.startup_cost = 0;
3543  pathnode->path.total_cost = 0;
3544  pathnode->path.rows = 0;
3545  total_size = 0;
3546  foreach(lc, subpaths)
3547  {
3548  Path *subpath = (Path *) lfirst(lc);
3549 
3550  if (lc == list_head(subpaths)) /* first node? */
3551  pathnode->path.startup_cost = subpath->startup_cost;
3552  pathnode->path.total_cost += subpath->total_cost;
3553  pathnode->path.rows += subpath->rows;
3554  total_size += subpath->pathtarget->width * subpath->rows;
3555  }
3556 
3557  /*
3558  * Set width to the average width of the subpath outputs. XXX this is
3559  * totally wrong: we should report zero if no RETURNING, else an average
3560  * of the RETURNING tlist widths. But it's what happened historically,
3561  * and improving it is a task for another day.
3562  */
3563  if (pathnode->path.rows > 0)
3564  total_size /= pathnode->path.rows;
3565  pathnode->path.pathtarget->width = rint(total_size);
3566 
3567  pathnode->operation = operation;
3568  pathnode->canSetTag = canSetTag;
3569  pathnode->nominalRelation = nominalRelation;
3570  pathnode->rootRelation = rootRelation;
3571  pathnode->partColsUpdated = partColsUpdated;
3572  pathnode->resultRelations = resultRelations;
3573  pathnode->subpaths = subpaths;
3574  pathnode->subroots = subroots;
3575  pathnode->withCheckOptionLists = withCheckOptionLists;
3576  pathnode->returningLists = returningLists;
3577  pathnode->rowMarks = rowMarks;
3578  pathnode->onconflict = onconflict;
3579  pathnode->epqParam = epqParam;
3580 
3581  return pathnode;
3582 }
3583 
3584 /*
3585  * create_limit_path
3586  * Creates a pathnode that represents performing LIMIT/OFFSET
3587  *
3588  * In addition to providing the actual OFFSET and LIMIT expressions,
3589  * the caller must provide estimates of their values for costing purposes.
3590  * The estimates are as computed by preprocess_limit(), ie, 0 represents
3591  * the clause not being present, and -1 means it's present but we could
3592  * not estimate its value.
3593  *
3594  * 'rel' is the parent relation associated with the result
3595  * 'subpath' is the path representing the source of data
3596  * 'limitOffset' is the actual OFFSET expression, or NULL
3597  * 'limitCount' is the actual LIMIT expression, or NULL
3598  * 'offset_est' is the estimated value of the OFFSET expression
3599  * 'count_est' is the estimated value of the LIMIT expression
3600  */
3601 LimitPath *
3603  Path *subpath,
3604  Node *limitOffset, Node *limitCount,
3605  LimitOption limitOption,
3606  int64 offset_est, int64 count_est)
3607 {
3608  LimitPath *pathnode = makeNode(LimitPath);
3609 
3610  pathnode->path.pathtype = T_Limit;
3611  pathnode->path.parent = rel;
3612  /* Limit doesn't project, so use source path's pathtarget */
3613  pathnode->path.pathtarget = subpath->pathtarget;
3614  /* For now, assume we are above any joins, so no parameterization */
3615  pathnode->path.param_info = NULL;
3616  pathnode->path.parallel_aware = false;
3617  pathnode->path.parallel_safe = rel->consider_parallel &&
3618  subpath->parallel_safe;
3619  pathnode->path.parallel_workers = subpath->parallel_workers;
3620  pathnode->path.rows = subpath->rows;
3621  pathnode->path.startup_cost = subpath->startup_cost;
3622  pathnode->path.total_cost = subpath->total_cost;
3623  pathnode->path.pathkeys = subpath->pathkeys;
3624  pathnode->subpath = subpath;
3625  pathnode->limitOffset = limitOffset;
3626  pathnode->limitCount = limitCount;
3627  pathnode->limitOption = limitOption;
3628 
3629  /*
3630  * Adjust the output rows count and costs according to the offset/limit.
3631  */
3632  adjust_limit_rows_costs(&pathnode->path.rows,
3633  &pathnode->path.startup_cost,
3634  &pathnode->path.total_cost,
3635  offset_est, count_est);
3636 
3637  return pathnode;
3638 }
3639 
3640 /*
3641  * adjust_limit_rows_costs
3642  * Adjust the size and cost estimates for a LimitPath node according to the
3643  * offset/limit.
3644  *
3645  * This is only a cosmetic issue if we are at top level, but if we are
3646  * building a subquery then it's important to report correct info to the outer
3647  * planner.
3648  *
3649  * When the offset or count couldn't be estimated, use 10% of the estimated
3650  * number of rows emitted from the subpath.
3651  *
3652  * XXX we don't bother to add eval costs of the offset/limit expressions
3653  * themselves to the path costs. In theory we should, but in most cases those
3654  * expressions are trivial and it's just not worth the trouble.
3655  */
3656 void
3657 adjust_limit_rows_costs(double *rows, /* in/out parameter */
3658  Cost *startup_cost, /* in/out parameter */
3659  Cost *total_cost, /* in/out parameter */
3660  int64 offset_est,
3661  int64 count_est)
3662 {
3663  double input_rows = *rows;
3664  Cost input_startup_cost = *startup_cost;
3665  Cost input_total_cost = *total_cost;
3666 
3667  if (offset_est != 0)
3668  {
3669  double offset_rows;
3670 
3671  if (offset_est > 0)
3672  offset_rows = (double) offset_est;
3673  else
3674  offset_rows = clamp_row_est(input_rows * 0.10);
3675  if (offset_rows > *rows)
3676  offset_rows = *rows;
3677  if (input_rows > 0)
3678  *startup_cost +=
3679  (input_total_cost - input_startup_cost)
3680  * offset_rows / input_rows;
3681  *rows -= offset_rows;
3682  if (*rows < 1)
3683  *rows = 1;
3684  }
3685 
3686  if (count_est != 0)
3687  {
3688  double count_rows;
3689 
3690  if (count_est > 0)
3691  count_rows = (double) count_est;
3692  else
3693  count_rows = clamp_row_est(input_rows * 0.10);
3694  if (count_rows > *rows)
3695  count_rows = *rows;
3696  if (input_rows > 0)
3697  *total_cost = *startup_cost +
3698  (input_total_cost - input_startup_cost)
3699  * count_rows / input_rows;
3700  *rows = count_rows;
3701  if (*rows < 1)
3702  *rows = 1;
3703  }
3704 }
3705 
3706 
3707 /*
3708  * reparameterize_path
3709  * Attempt to modify a Path to have greater parameterization
3710  *
3711  * We use this to attempt to bring all child paths of an appendrel to the
3712  * same parameterization level, ensuring that they all enforce the same set
3713  * of join quals (and thus that that parameterization can be attributed to
3714  * an append path built from such paths). Currently, only a few path types
3715  * are supported here, though more could be added at need. We return NULL
3716  * if we can't reparameterize the given path.
3717  *
3718  * Note: we intentionally do not pass created paths to add_path(); it would
3719  * possibly try to delete them on the grounds of being cost-inferior to the
3720  * paths they were made from, and we don't want that. Paths made here are
3721  * not necessarily of general-purpose usefulness, but they can be useful
3722  * as members of an append path.
3723  */
3724 Path *
3726  Relids required_outer,
3727  double loop_count)
3728 {
3729  RelOptInfo *rel = path->parent;
3730 
3731  /* Can only increase, not decrease, path's parameterization */
3732  if (!bms_is_subset(PATH_REQ_OUTER(path), required_outer))
3733  return NULL;
3734  switch (path->pathtype)
3735  {
3736  case T_SeqScan:
3737  return create_seqscan_path(root, rel, required_outer, 0);
3738  case T_SampleScan:
3739  return (Path *) create_samplescan_path(root, rel, required_outer);
3740  case T_IndexScan:
3741  case T_IndexOnlyScan:
3742  {
3743  IndexPath *ipath = (IndexPath *) path;
3744  IndexPath *newpath = makeNode(IndexPath);
3745 
3746  /*
3747  * We can't use create_index_path directly, and would not want
3748  * to because it would re-compute the indexqual conditions
3749  * which is wasted effort. Instead we hack things a bit:
3750  * flat-copy the path node, revise its param_info, and redo
3751  * the cost estimate.
3752  */
3753  memcpy(newpath, ipath, sizeof(IndexPath));
3754  newpath->path.param_info =
3755  get_baserel_parampathinfo(root, rel, required_outer);
3756  cost_index(newpath, root, loop_count, false);
3757  return (Path *) newpath;
3758  }
3759  case T_BitmapHeapScan:
3760  {
3761  BitmapHeapPath *bpath = (BitmapHeapPath *) path;
3762 
3763  return (Path *) create_bitmap_heap_path(root,
3764  rel,
3765  bpath->bitmapqual,
3766  required_outer,
3767  loop_count, 0);
3768  }
3769  case T_SubqueryScan:
3770  {
3771  SubqueryScanPath *spath = (SubqueryScanPath *) path;
3772 
3773  return (Path *) create_subqueryscan_path(root,
3774  rel,
3775  spath->subpath,
3776  spath->path.pathkeys,
3777  required_outer);
3778  }
3779  case T_Result:
3780  /* Supported only for RTE_RESULT scan paths */
3781  if (IsA(path, Path))
3782  return create_resultscan_path(root, rel, required_outer);
3783  break;
3784  case T_Append:
3785  {
3786  AppendPath *apath = (AppendPath *) path;
3787  List *childpaths = NIL;
3788  List *partialpaths = NIL;
3789  int i;
3790  ListCell *lc;
3791 
3792  /* Reparameterize the children */
3793  i = 0;
3794  foreach(lc, apath->subpaths)
3795  {
3796  Path *spath = (Path *) lfirst(lc);
3797 
3798  spath = reparameterize_path(root, spath,
3799  required_outer,
3800  loop_count);
3801  if (spath == NULL)
3802  return NULL;
3803  /* We have to re-split the regular and partial paths */
3804  if (i < apath->first_partial_path)
3805  childpaths = lappend(childpaths, spath);
3806  else
3807  partialpaths = lappend(partialpaths, spath);
3808  i++;
3809  }
3810  return (Path *)
3811  create_append_path(root, rel, childpaths, partialpaths,
3812  apath->path.pathkeys, required_outer,
3813  apath->path.parallel_workers,
3814  apath->path.parallel_aware,
3815  apath->partitioned_rels,
3816  -1);
3817  }
3818  default:
3819  break;
3820  }
3821  return NULL;
3822 }
3823 
3824 /*
3825  * reparameterize_path_by_child
3826  * Given a path parameterized by the parent of the given child relation,
3827  * translate the path to be parameterized by the given child relation.
3828  *
3829  * The function creates a new path of the same type as the given path, but
3830  * parameterized by the given child relation. Most fields from the original
3831  * path can simply be flat-copied, but any expressions must be adjusted to
3832  * refer to the correct varnos, and any paths must be recursively
3833  * reparameterized. Other fields that refer to specific relids also need
3834  * adjustment.
3835  *
3836  * The cost, number of rows, width and parallel path properties depend upon
3837  * path->parent, which does not change during the translation. Hence those
3838  * members are copied as they are.
3839  *
3840  * If the given path can not be reparameterized, the function returns NULL.
3841  */
3842 Path *
3844  RelOptInfo *child_rel)
3845 {
3846 
3847 #define FLAT_COPY_PATH(newnode, node, nodetype) \
3848  ( (newnode) = makeNode(nodetype), \
3849  memcpy((newnode), (node), sizeof(nodetype)) )
3850 
3851 #define ADJUST_CHILD_ATTRS(node) \
3852  ((node) = \
3853  (List *) adjust_appendrel_attrs_multilevel(root, (Node *) (node), \
3854  child_rel->relids, \
3855  child_rel->top_parent_relids))
3856 
3857 #define REPARAMETERIZE_CHILD_PATH(path) \
3858 do { \
3859  (path) = reparameterize_path_by_child(root, (path), child_rel); \
3860  if ((path) == NULL) \
3861  return NULL; \
3862 } while(0)
3863 
3864 #define REPARAMETERIZE_CHILD_PATH_LIST(pathlist) \
3865 do { \
3866  if ((pathlist) != NIL) \
3867  { \
3868  (pathlist) = reparameterize_pathlist_by_child(root, (pathlist), \
3869  child_rel); \
3870  if ((pathlist) == NIL) \
3871  return NULL; \
3872  } \
3873 } while(0)
3874 
3875  Path *new_path;
3876  ParamPathInfo *new_ppi;
3877  ParamPathInfo *old_ppi;
3878  Relids required_outer;
3879 
3880  /*
3881  * If the path is not parameterized by parent of the given relation, it
3882  * doesn't need reparameterization.
3883  */
3884  if (!path->param_info ||
3885  !bms_overlap(PATH_REQ_OUTER(path), child_rel->top_parent_relids))
3886  return path;
3887 
3888  /* Reparameterize a copy of given path. */
3889  switch (nodeTag(path))
3890  {
3891  case T_Path:
3892  FLAT_COPY_PATH(new_path, path, Path);
3893  break;
3894 
3895  case T_IndexPath:
3896  {
3897  IndexPath *ipath;
3898 
3899  FLAT_COPY_PATH(ipath, path, IndexPath);
3901  new_path = (Path *) ipath;
3902  }
3903  break;
3904 
3905  case T_BitmapHeapPath:
3906  {
3907  BitmapHeapPath *bhpath;
3908 
3909  FLAT_COPY_PATH(bhpath, path, BitmapHeapPath);
3911  new_path = (Path *) bhpath;
3912  }
3913  break;
3914 
3915  case T_BitmapAndPath:
3916  {
3917  BitmapAndPath *bapath;
3918 
3919  FLAT_COPY_PATH(bapath, path, BitmapAndPath);
3921  new_path = (Path *) bapath;
3922  }
3923  break;
3924 
3925  case T_BitmapOrPath:
3926  {
3927  BitmapOrPath *bopath;
3928 
3929  FLAT_COPY_PATH(bopath, path, BitmapOrPath);
3931  new_path = (Path *) bopath;
3932  }
3933  break;
3934 
3935  case T_TidPath:
3936  {
3937  TidPath *tpath;
3938 
3939  FLAT_COPY_PATH(tpath, path, TidPath);
3940  ADJUST_CHILD_ATTRS(tpath->tidquals);
3941  new_path = (Path *) tpath;
3942  }
3943  break;
3944 
3945  case T_ForeignPath:
3946  {
3947  ForeignPath *fpath;
3949 
3950  FLAT_COPY_PATH(fpath, path, ForeignPath);
3951  if (fpath->fdw_outerpath)
3953 
3954  /* Hand over to FDW if needed. */
3955  rfpc_func =
3957  if (rfpc_func)
3958  fpath->fdw_private = rfpc_func(root, fpath->fdw_private,
3959  child_rel);
3960  new_path = (Path *) fpath;
3961  }
3962  break;
3963 
3964  case T_CustomPath:
3965  {
3966  CustomPath *cpath;
3967 
3968  FLAT_COPY_PATH(cpath, path, CustomPath);
3970  if (cpath->methods &&
3972  cpath->custom_private =
3974  cpath->custom_private,
3975  child_rel);
3976  new_path = (Path *) cpath;
3977  }
3978  break;
3979 
3980  case T_NestPath:
3981  {
3982  JoinPath *jpath;
3983 
3984  FLAT_COPY_PATH(jpath, path, NestPath);
3985 
3989  new_path = (Path *) jpath;
3990  }
3991  break;
3992 
3993  case T_MergePath:
3994  {
3995  JoinPath *jpath;
3996  MergePath *mpath;
3997 
3998  FLAT_COPY_PATH(mpath, path, MergePath);
3999 
4000  jpath = (JoinPath *) mpath;
4005  new_path = (Path *) mpath;
4006  }
4007  break;
4008 
4009  case T_HashPath:
4010  {
4011  JoinPath *jpath;
4012  HashPath *hpath;
4013 
4014  FLAT_COPY_PATH(hpath, path, HashPath);
4015 
4016  jpath = (JoinPath *) hpath;
4021  new_path = (Path *) hpath;
4022  }
4023  break;
4024 
4025  case T_AppendPath:
4026  {
4027  AppendPath *apath;
4028 
4029  FLAT_COPY_PATH(apath, path, AppendPath);
4031  new_path = (Path *) apath;
4032  }
4033  break;
4034 
4035  case T_MergeAppendPath:
4036  {
4037  MergeAppendPath *mapath;
4038 
4039  FLAT_COPY_PATH(mapath, path, MergeAppendPath);
4041  new_path = (Path *) mapath;
4042  }
4043  break;
4044 
4045  case T_MaterialPath:
4046  {
4047  MaterialPath *mpath;
4048 
4049  FLAT_COPY_PATH(mpath, path, MaterialPath);
4051  new_path = (Path *) mpath;
4052  }
4053  break;
4054 
4055  case T_UniquePath:
4056  {
4057  UniquePath *upath;
4058 
4059  FLAT_COPY_PATH(upath, path, UniquePath);
4062  new_path = (Path *) upath;
4063  }
4064  break;
4065 
4066  case T_GatherPath:
4067  {
4068  GatherPath *gpath;
4069 
4070  FLAT_COPY_PATH(gpath, path, GatherPath);
4072  new_path = (Path *) gpath;
4073  }
4074  break;
4075 
4076  case T_GatherMergePath:
4077  {
4078  GatherMergePath *gmpath;
4079 
4080  FLAT_COPY_PATH(gmpath, path, GatherMergePath);
4082  new_path = (Path *) gmpath;
4083  }
4084  break;
4085 
4086  default:
4087 
4088  /* We don't know how to reparameterize this path. */
4089  return NULL;
4090  }
4091 
4092  /*
4093  * Adjust the parameterization information, which refers to the topmost
4094  * parent. The topmost parent can be multiple levels away from the given
4095  * child, hence use multi-level expression adjustment routines.
4096  */
4097  old_ppi = new_path->param_info;
4098  required_outer =
4100  child_rel->relids,
4101  child_rel->top_parent_relids);
4102 
4103  /* If we already have a PPI for this parameterization, just return it */
4104  new_ppi = find_param_path_info(new_path->parent, required_outer);
4105 
4106  /*
4107  * If not, build a new one and link it to the list of PPIs. For the same
4108  * reason as explained in mark_dummy_rel(), allocate new PPI in the same
4109  * context the given RelOptInfo is in.
4110  */
4111  if (new_ppi == NULL)
4112  {
4113  MemoryContext oldcontext;
4114  RelOptInfo *rel = path->parent;
4115 
4116  oldcontext = MemoryContextSwitchTo(GetMemoryChunkContext(rel));
4117 
4118  new_ppi = makeNode(ParamPathInfo);
4119  new_ppi->ppi_req_outer = bms_copy(required_outer);
4120  new_ppi->ppi_rows = old_ppi->ppi_rows;
4121  new_ppi->ppi_clauses = old_ppi->ppi_clauses;
4122  ADJUST_CHILD_ATTRS(new_ppi->ppi_clauses);
4123  rel->ppilist = lappend(rel->ppilist, new_ppi);
4124 
4125  MemoryContextSwitchTo(oldcontext);
4126  }
4127  bms_free(required_outer);
4128 
4129  new_path->param_info = new_ppi;
4130 
4131  /*
4132  * Adjust the path target if the parent of the outer relation is
4133  * referenced in the targetlist. This can happen when only the parent of
4134  * outer relation is laterally referenced in this relation.
4135  */
4136  if (bms_overlap(path->parent->lateral_relids,
4137  child_rel->top_parent_relids))
4138  {
4139  new_path->pathtarget = copy_pathtarget(new_path->pathtarget);
4140  ADJUST_CHILD_ATTRS(new_path->pathtarget->exprs);
4141  }
4142 
4143  return new_path;
4144 }
4145 
4146 /*
4147  * reparameterize_pathlist_by_child
4148  * Helper function to reparameterize a list of paths by given child rel.
4149  */
4150 static List *
4152  List *pathlist,
4153  RelOptInfo *child_rel)
4154 {
4155  ListCell *lc;
4156  List *result = NIL;
4157 
4158  foreach(lc, pathlist)
4159  {
4160  Path *path = reparameterize_path_by_child(root, lfirst(lc),
4161  child_rel);
4162 
4163  if (path == NULL)
4164  {
4165  list_free(result);
4166  return NIL;
4167  }
4168 
4169  result = lappend(result, path);
4170  }
4171 
4172  return result;
4173 }
Path * apply_projection_to_path(PlannerInfo *root, RelOptInfo *rel, Path *path, PathTarget *target)
Definition: pathnode.c:2611
struct Path * cheapest_unique_path
Definition: pathnodes.h:684
List * indexorderbycols
Definition: pathnodes.h:1210
List * group_pathkeys
Definition: pathnodes.h:300
#define NIL
Definition: pg_list.h:65
PathTarget * copy_pathtarget(PathTarget *src)
Definition: tlist.c:672
void final_cost_hashjoin(PlannerInfo *root, HashPath *path, JoinCostWorkspace *workspace, JoinPathExtraData *extra)
Definition: costsize.c:3587
List * qual
Definition: pathnodes.h:1673
void cost_incremental_sort(Path *path, PlannerInfo *root, List *pathkeys, int presorted_keys, Cost input_startup_cost, Cost input_total_cost, double input_tuples, int width, Cost comparison_cost, int sort_mem, double limit_tuples)
Definition: costsize.c:1789
double expression_returns_set_rows(PlannerInfo *root, Node *clause)
Definition: clauses.c:571
ParamPathInfo * find_param_path_info(RelOptInfo *rel, Relids required_outer)
Definition: relnode.c:1608
double estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows, List **pgset)
Definition: selfuncs.c:3357
List * path_mergeclauses
Definition: pathnodes.h:1581
List * outersortkeys
Definition: pathnodes.h:1582
List * distinctList
Definition: pathnodes.h:1773
MinMaxAggPath * create_minmaxagg_path(PlannerInfo *root, RelOptInfo *rel, PathTarget *target, List *mmaggregates, List *quals)
Definition: pathnode.c:3201
Definition: nodes.h:79
GatherPath * create_gather_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, Relids required_outer, double *rows)
Definition: pathnode.c:1845
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
JoinPath jpath
Definition: pathnodes.h:1599
PathTarget * pathtarget
Definition: pathnodes.h:1145
ForeignPath * create_foreign_upper_path(PlannerInfo *root, RelOptInfo *rel, PathTarget *target, double rows, Cost startup_cost, Cost total_cost, List *pathkeys, Path *fdw_outerpath, List *fdw_private)
Definition: pathnode.c:2194
LimitOption limitOption
Definition: pathnodes.h:1837
List * returningLists
Definition: pathnodes.h:1822
bool query_is_distinct_for(Query *query, List *colnos, List *opids)
Definition: analyzejoins.c:775
OnConflictExpr * onconflict
Definition: pathnodes.h:1824
void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info, Path *bitmapqual, double loop_count)
Definition: costsize.c:943
Node * limitOffset
Definition: pathnodes.h:1835
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
Path path
Definition: pathnodes.h:1206
SubqueryScanPath * create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, Relids required_outer)
Definition: pathnode.c:1884
Bitmapset * bms_copy(const Bitmapset *a)
Definition: bitmapset.c:74
Path * subpath
Definition: pathnodes.h:1648
IndexOptInfo * indexinfo
Definition: pathnodes.h:1207
ParamPathInfo * get_baserel_parampathinfo(PlannerInfo *root, RelOptInfo *baserel, Relids required_outer)
Definition: relnode.c:1279
Index nominalRelation
Definition: pathnodes.h:1815
Path * fdw_outerpath
Definition: pathnodes.h:1349
RelOptKind reloptkind
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void cost_tidscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, List *tidquals, ParamPathInfo *param_info)
Definition: costsize.c:1179
void cost_windowagg(Path *path, PlannerInfo *root, List *windowFuncs, int numPartCols, int numOrderCols, Cost input_startup_cost, Cost input_total_cost, double input_tuples)
Definition: costsize.c:2495
List * custom_paths
Definition: pathnodes.h:1379
Definition: nodes.h:81
SetOpStrategy strategy
Definition: pathnodes.h:1772
AggStrategy aggstrategy
Definition: pathnodes.h:1700
LockRowsPath * create_lockrows_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *rowMarks, int epqParam)
Definition: pathnode.c:3441
SortPath * create_incremental_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, int presorted_keys, double limit_tuples)
Definition: pathnode.c:2769
int bms_compare(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:147
void cost_gather_merge(GatherMergePath *path, PlannerInfo *root, RelOptInfo *rel, ParamPathInfo *param_info, Cost input_startup_cost, Cost input_total_cost, double *rows)
Definition: costsize.c:404
SetOpPath * create_setop_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, SetOpCmd cmd, SetOpStrategy strategy, List *distinctList, AttrNumber flagColIdx, int firstFlag, double numGroups, double outputRows)
Definition: pathnode.c:3334
ParamPathInfo * get_joinrel_parampathinfo(PlannerInfo *root, RelOptInfo *joinrel, Path *outer_path, Path *inner_path, SpecialJoinInfo *sjinfo, Relids required_outer, List **restrict_clauses)
Definition: relnode.c:1369
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:3033
List * qual
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double limit_tuples
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UpperUniquePath * create_upper_unique_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, int numCols, double numGroups)
Definition: pathnode.c:2921
bool add_partial_path_precheck(RelOptInfo *parent_rel, Cost total_cost, List *pathkeys)
Definition: pathnode.c:867
bool add_path_precheck(RelOptInfo *parent_rel, Cost startup_cost, Cost total_cost, List *pathkeys, Relids required_outer)
Definition: pathnode.c:644
Path * innerjoinpath
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struct Path * cheapest_startup_path
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Path * create_resultscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
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void cost_agg(Path *path, PlannerInfo *root, AggStrategy aggstrategy, const AggClauseCosts *aggcosts, int numGroupCols, double numGroups, List *quals, Cost input_startup_cost, Cost input_total_cost, double input_tuples, double input_width)
Definition: costsize.c:2311
double tuples
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Path * subpath
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int parallel_workers
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void cost_bitmap_and_node(BitmapAndPath *path, PlannerInfo *root)
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static MemoryContext MemoryContextSwitchTo(MemoryContext context)
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struct List *(* ReparameterizeCustomPathByChild)(PlannerInfo *root, List *custom_private, RelOptInfo *child_rel)
Definition: extensible.h:99
bool is_hashed
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ParamPathInfo * param_info
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Relids calc_non_nestloop_required_outer(Path *outer_path, Path *inner_path)
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List * list_copy(const List *oldlist)
Definition: list.c:1403
Definition: nodes.h:529
ProjectionPath * create_projection_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target)
Definition: pathnode.c:2520
LimitPath * create_limit_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, Node *limitOffset, Node *limitCount, LimitOption limitOption, int64 offset_est, int64 count_est)
Definition: pathnode.c:3602
List * list_concat(List *list1, const List *list2)
Definition: list.c:515
Definition: nodes.h:49
List * partial_pathlist
Definition: pathnodes.h:681
HashPath * create_hashjoin_path(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, JoinCostWorkspace *workspace, JoinPathExtraData *extra, Path *outer_path, Path *inner_path, bool parallel_hash, List *restrict_clauses, Relids required_outer, List *hashclauses)
Definition: pathnode.c:2454
AttrNumber varattno
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void cost_valuesscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:1451
void cost_ctescan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:1501
Relids adjust_child_relids_multilevel(PlannerInfo *root, Relids relids, Relids child_relids, Relids top_parent_relids)
Definition: appendinfo.c:576
List * cheapest_parameterized_paths
Definition: pathnodes.h:685
bool single_copy
Definition: pathnodes.h:1496
UniquePathMethod umethod
Definition: pathnodes.h:1482
PathKeysComparison compare_pathkeys(List *keys1, List *keys2)
Definition: pathkeys.c:285
Definition: nodes.h:76
UniquePath * create_unique_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, SpecialJoinInfo *sjinfo)
Definition: pathnode.c:1534
Path * subpath
Definition: pathnodes.h:1456
List * indexclauses
Definition: pathnodes.h:1208
AggSplit aggsplit
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List * partitioned_rels
Definition: pathnodes.h:1429
MergePath * create_mergejoin_path(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, JoinCostWorkspace *workspace, JoinPathExtraData *extra, Path *outer_path, Path *inner_path, List *restrict_clauses, List *pathkeys, Relids required_outer, List *mergeclauses, List *outersortkeys, List *innersortkeys)
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static int append_total_cost_compare(const ListCell *a, const ListCell *b)
Definition: pathnode.c:1305
Definition: primnodes.h:181
Path * create_functionscan_path(PlannerInfo *root, RelOptInfo *rel, List *pathkeys, Relids required_outer)
Definition: pathnode.c:1912
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Definition: pathnodes.h:1702
double numGroups
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SetOpStrategy
Definition: nodes.h:810
#define ADJUST_CHILD_ATTRS(node)
List * rowMarks
Definition: pathnodes.h:1799
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:638
double numGroups
Definition: pathnodes.h:1725
Cost startup
Definition: pathnodes.h:45
void adjust_limit_rows_costs(double *rows, Cost *startup_cost, Cost *total_cost, int64 offset_est, int64 count_est)
Definition: pathnode.c:3657
List * bitmapquals
Definition: pathnodes.h:1292
List * custom_private
Definition: pathnodes.h:1380
uint64 transitionSpace
Definition: pathnodes.h:1741
JoinType
Definition: nodes.h:696
int first_partial_path
Definition: pathnodes.h:1406
WindowClause * winclause
Definition: pathnodes.h:1761
Path * create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1964
List * bitmapquals
Definition: pathnodes.h:1305
int num_workers
Definition: pathnodes.h:1497
Definition: type.h:89
#define foreach_delete_current(lst, cell)
Definition: pg_list.h:368
NodeTag pathtype
Definition: pathnodes.h:1142
Relids syn_righthand
Definition: pathnodes.h:2178
List * subpaths
Definition: pathnodes.h:1404
List * list_insert_nth(List *list, int pos, void *datum)
Definition: list.c:400
SetOpCmd cmd
Definition: pathnodes.h:1771
void final_cost_nestloop(PlannerInfo *root, NestPath *path, JoinCostWorkspace *workspace, JoinPathExtraData *extra)
Definition: costsize.c:2714
static List * reparameterize_pathlist_by_child(PlannerInfo *root, List *pathlist, RelOptInfo *child_rel)
Definition: pathnode.c:4151
#define true
Definition: c.h:321
bool consider_startup
Definition: pathnodes.h:671
bool is_parallel_safe(PlannerInfo *root, Node *node)
Definition: clauses.c:856
void cost_seqscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:214
Relids lateral_relids
Definition: pathnodes.h:690
static int append_startup_cost_compare(const ListCell *a, const ListCell *b)
Definition: pathnode.c:1327
Cost per_tuple
Definition: pathnodes.h:46
const struct CustomPathMethods * methods
Definition: pathnodes.h:1381
Path * subpath
Definition: pathnodes.h:1760
void pfree(void *pointer)
Definition: mcxt.c:1056
RelOptInfo * rel
Definition: pathnodes.h:820
SpecialJoinInfo * sjinfo
Definition: pathnodes.h:2427
#define linitial(l)
Definition: pg_list.h:195
Definition: nodes.h:46
Relids all_baserels
Definition: pathnodes.h:227
#define ERROR
Definition: elog.h:43
ModifyTablePath * create_modifytable_path(PlannerInfo *root, RelOptInfo *rel, CmdType operation, bool canSetTag, Index nominalRelation, Index rootRelation, bool partColsUpdated, List *resultRelations, List *subpaths, List *subroots, List *withCheckOptionLists, List *returningLists, List *rowMarks, OnConflictExpr *onconflict, int epqParam)
Definition: pathnode.c:3500
static List * translate_sub_tlist(List *tlist, int relid)
Definition: pathnode.c:1819
double limit_tuples
Definition: pathnodes.h:337
List * partitionClause
Definition: parsenodes.h:1353
void cost_qual_eval(QualCost *cost, List *quals, PlannerInfo *root)
Definition: costsize.c:4042
Cost startup_cost
Definition: pathnodes.h:1155
RecursiveUnionPath * create_recursiveunion_path(PlannerInfo *root, RelOptInfo *rel, Path *leftpath, Path *rightpath, PathTarget *target, List *distinctList, int wtParam, double numGroups)
Definition: pathnode.c:3396
List * semi_rhs_exprs
Definition: pathnodes.h:2186
void cost_subqueryscan(SubqueryScanPath *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:1285
void cost_group(Path *path, PlannerInfo *root, int numGroupCols, double numGroups, List *quals, Cost input_startup_cost, Cost input_total_cost, double input_tuples)
Definition: costsize.c:2569
Path * subpath
Definition: pathnodes.h:1834
List * joinrestrictinfo
Definition: pathnodes.h:1528
#define planner_rt_fetch(rti, root)
Definition: pathnodes.h:373
bool partColsUpdated
Definition: pathnodes.h:1817
RelOptInfo * parent
Definition: pathnodes.h:1144
List * uniq_exprs
Definition: pathnodes.h:1484
Path * reparameterize_path_by_child(PlannerInfo *root, Path *path, RelOptInfo *child_rel)
Definition: pathnode.c:3843
Path * bitmapqual
Definition: pathnodes.h:1280
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:315
Definition: nodes.h:78
Path path
Definition: pathnodes.h:1670
int compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
Definition: pathnode.c:71
NestPath * create_nestloop_path(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, JoinCostWorkspace *workspace, JoinPathExtraData *extra, Path *outer_path, Path *inner_path, List *restrict_clauses, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2300
AggPath * create_agg_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, AggStrategy aggstrategy, AggSplit aggsplit, List *groupClause, List *qual, const AggClauseCosts *aggcosts, double numGroups)
Definition: pathnode.c:2973
struct Path * cheapest_total_path
Definition: pathnodes.h:683
IndexPath * create_index_path(PlannerInfo *root, IndexOptInfo *index, List *indexclauses, List *indexorderbys, List *indexorderbycols, List *pathkeys, ScanDirection indexscandir, bool indexonly, Relids required_outer, double loop_count, bool partial_path)
Definition: pathnode.c:997
#define PATH_REQ_OUTER(path)
Definition: pathnodes.h:1163
ForeignPath * create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel, PathTarget *target, double rows, Cost startup_cost, Cost total_cost, List *pathkeys, Relids required_outer, Path *fdw_outerpath, List *fdw_private)
Definition: pathnode.c:2100
ProjectSetPath * create_set_projection_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target)
Definition: pathnode.c:2700
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:718
static PathCostComparison compare_path_costs_fuzzily(Path *path1, Path *path2, double fuzz_factor)
Definition: pathnode.c:166
ScanDirection
Definition: sdir.h:22
Datum sort(PG_FUNCTION_ARGS)
Definition: _int_op.c:195
List * groupClause
Definition: pathnodes.h:1704
static ListCell * list_head(const List *l)
Definition: pg_list.h:125
ForeignPath * create_foreign_join_path(PlannerInfo *root, RelOptInfo *rel, PathTarget *target, double rows, Cost startup_cost, Cost total_cost, List *pathkeys, Relids required_outer, Path *fdw_outerpath, List *fdw_private)
Definition: pathnode.c:2144
AttrNumber flagColIdx
Definition: pathnodes.h:1774
MergeAppendPath * create_merge_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *pathkeys, Relids required_outer, List *partitioned_rels)
Definition: pathnode.c:1345
Relids relids
Definition: pathnodes.h:665
AggStrategy aggstrategy
Definition: pathnodes.h:1738
double cpu_operator_cost
Definition: costsize.c:115
Path * subpath
Definition: pathnodes.h:1495
void cost_samplescan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:291
bool join_clause_is_movable_into(RestrictInfo *rinfo, Relids currentrelids, Relids current_and_outer)
Definition: restrictinfo.c:577
List * ppilist
Definition: pathnodes.h:680
AppendPath * create_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *partial_subpaths, List *pathkeys, Relids required_outer, int parallel_workers, bool parallel_aware, List *partitioned_rels, double rows)
Definition: pathnode.c:1183
List * lappend_int(List *list, int datum)
Definition: list.c:339
Index relid
Definition: pathnodes.h:693
Path * create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2067
List * lappend(List *list, void *datum)
Definition: list.c:321
Path * subpath
Definition: pathnodes.h:1798
bool bms_is_empty(const Bitmapset *a)
Definition: bitmapset.c:701
#define FLAT_COPY_PATH(newnode, node, nodetype)
Index varno
Definition: primnodes.h:184
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244
List * exprs
Definition: pathnodes.h:1074
#define REPARAMETERIZE_CHILD_PATH(path)
BitmapAndPath * create_bitmap_and_path(PlannerInfo *root, RelOptInfo *rel, List *bitmapquals)
Definition: pathnode.c:1079
bool pathkeys_contained_in(List *keys1, List *keys2)
Definition: pathkeys.c:324
Path * outerjoinpath
Definition: pathnodes.h:1525
void cost_index(IndexPath *path, PlannerInfo *root, double loop_count, bool partial_path)
Definition: costsize.c:479
List * indexorderbys
Definition: pathnodes.h:1209
void cost_recursive_union(Path *runion, Path *nrterm, Path *rterm)
Definition: costsize.c:1616
Path * create_samplescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:954
List * groupClause
Definition: pathnodes.h:1672
Path * create_tablefuncscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1938
List * mmaggregates
Definition: pathnodes.h:1750
List * tidquals
Definition: pathnodes.h:1319
void cost_sort(Path *path, PlannerInfo *root, List *pathkeys, Cost input_cost, double tuples, int width, Cost comparison_cost, int sort_mem, double limit_tuples)
Definition: costsize.c:1928
int work_mem
Definition: globals.c:121
Path * subpath
Definition: pathnodes.h:1671
#define REPARAMETERIZE_CHILD_PATH_LIST(pathlist)
unsigned int Index
Definition: c.h:475
int64 total_size
Definition: pg_checksums.c:68
RTEKind rtekind
Definition: pathnodes.h:695
PathCostComparison
Definition: pathnode.c:38
List * in_operators
Definition: pathnodes.h:1483
void cost_resultscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:1579
double rows
Definition: pathnodes.h:668
GatherMergePath * create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, List *pathkeys, Relids required_outer, double *rows)
Definition: pathnode.c:1754
SortPath * create_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, double limit_tuples)
Definition: pathnode.c:2818
BMS_Comparison bms_subset_compare(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:352
Cost total_cost
Definition: pathnodes.h:1156
void cost_material(Path *path, Cost input_startup_cost, Cost input_total_cost, double tuples, int width)
Definition: costsize.c:2257
CostSelector
Definition: pathnodes.h:34
int firstFlag
Definition: pathnodes.h:1775
List * lcons(void *datum, List *list)
Definition: list.c:453
List * pathkeys
Definition: pathnodes.h:1158
WindowAggPath * create_windowagg_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, List *windowFuncs, WindowClause *winclause)
Definition: pathnode.c:3272
void bms_free(Bitmapset *a)
Definition: bitmapset.c:208
#define makeNode(_type_)
Definition: nodes.h:577
void cost_tablefuncscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:1395
void cost_merge_append(Path *path, PlannerInfo *root, List *pathkeys, int n_streams, Cost input_startup_cost, Cost input_total_cost, double tuples)
Definition: costsize.c:2208
uint64 transitionSpace
Definition: pathnodes.h:1703
#define CONSIDER_PATH_STARTUP_COST(p)
Path path
Definition: pathnodes.h:1518
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
void cost_append(AppendPath *apath)
Definition: costsize.c:2035
Path * subpath
Definition: pathnodes.h:1634
double rows
Definition: pathnodes.h:1154
bool parallel_safe
Definition: pathnodes.h:1150
int compare_fractional_path_costs(Path *path1, Path *path2, double fraction)
Definition: pathnode.c:117
Index rootRelation
Definition: pathnodes.h:1816
JoinType jointype
Definition: pathnodes.h:2179
List * ppi_clauses
Definition: pathnodes.h:1105
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:225
#define STD_FUZZ_FACTOR
Definition: pathnode.c:51
QualCost cost
Definition: pathnodes.h:1076
AggSplit
Definition: nodes.h:780
static int list_length(const List *l)
Definition: pg_list.h:169
Relids calc_nestloop_required_outer(Relids outerrelids, Relids outer_paramrels, Relids innerrelids, Relids inner_paramrels)
Definition: pathnode.c:2234
bool inner_unique
Definition: pathnodes.h:1522
bool consider_parallel
Definition: pathnodes.h:673
List * innersortkeys
Definition: pathnodes.h:1583
double cpu_tuple_cost
Definition: costsize.c:113
Path * subpath
Definition: pathnodes.h:1699
bool query_supports_distinctness(Query *query)
Definition: analyzejoins.c:738
LimitOption
Definition: nodes.h:835
List * partitioned_rels
Definition: pathnodes.h:1403
void cost_gather(GatherPath *path, PlannerInfo *root, RelOptInfo *rel, ParamPathInfo *param_info, double *rows)
Definition: costsize.c:366
#define nodeTag(nodeptr)
Definition: nodes.h:534
double ppi_rows
Definition: pathnodes.h:1104
Path path
Definition: pathnodes.h:1833
Path path
Definition: pathnodes.h:1318
List * withCheckOptionLists
Definition: pathnodes.h:1821
Bitmapset * bms_del_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:928
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:494
Definition: nodes.h:85
List * orderClause
Definition: parsenodes.h:1354
PathKeysComparison
Definition: paths.h:181
Query * subquery
Definition: parsenodes.h:1011
AggStrategy
Definition: nodes.h:758
bool is_projection_capable_path(Path *path)
Definition: createplan.c:6943
TidPath * create_tidscan_path(PlannerInfo *root, RelOptInfo *rel, List *tidquals, Relids required_outer)
Definition: pathnode.c:1151
Path * reparameterize_path(PlannerInfo *root, Path *path, Relids required_outer, double loop_count)
Definition: pathnode.c:3725
void cost_functionscan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info)
Definition: costsize.c:1334
void list_sort(List *list, list_sort_comparator cmp)
Definition: list.c:1481
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:749
List * fdw_private
Definition: pathnodes.h:1350
SetOpCmd
Definition: nodes.h:802
JoinType jointype
Definition: pathnodes.h:1520
List * semi_operators
Definition: pathnodes.h:2185
ScanDirection indexscandir
Definition: pathnodes.h:1211
CmdType operation
Definition: pathnodes.h:1813
void list_free(List *list)
Definition: list.c:1376
Definition: nodes.h:82
#define elog(elevel,...)
Definition: elog.h:214
int i
List * resultRelations
Definition: pathnodes.h:1818
Size transitionSpace
Definition: pathnodes.h:64
void cost_bitmap_or_node(BitmapOrPath *path, PlannerInfo *root)
Definition: costsize.c:1131
JoinPath jpath
Definition: pathnodes.h:1580
bool parallel_aware
Definition: pathnodes.h:1149
List * path_hashclauses
Definition: pathnodes.h:1600
GroupResultPath * create_group_result_path(PlannerInfo *root, RelOptInfo *rel, PathTarget *target, List *havingqual)
Definition: pathnode.c:1447
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:99
List *(* ReparameterizeForeignPathByChild_function)(PlannerInfo *root, List *fdw_private, RelOptInfo *child_rel)
Definition: fdwapi.h:169
List * pathlist
Definition: pathnodes.h:679
Relids ppi_req_outer
Definition: pathnodes.h:1103
ParamPathInfo * get_appendrel_parampathinfo(RelOptInfo *appendrel, Relids required_outer)
Definition: relnode.c:1576
bool relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel, List *restrictlist, List *exprlist, List *oprlist)
Definition: indxpath.c:3586
Path * subpath
Definition: pathnodes.h:1622
Definition: nodes.h:228
GroupPath * create_group_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *groupClause, List *qual, double numGroups)
Definition: pathnode.c:2862
double clamp_row_est(double nrows)
Definition: costsize.c:190
Node * limitCount
Definition: pathnodes.h:1836
Definition: pg_list.h:50
Path path
Definition: pathnodes.h:1647
struct PathTarget * reltarget
Definition: pathnodes.h:676
int16 AttrNumber
Definition: attnum.h:21
Path path
Definition: pathnodes.h:1769
CmdType
Definition: nodes.h:672
Path * create_seqscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer, int parallel_workers)
Definition: pathnode.c:929
Path path
Definition: pathnodes.h:1698
double limit_tuples
Definition: pathnodes.h:1431
GroupingSetsPath * create_groupingsets_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *having_qual, AggStrategy aggstrategy, List *rollups, const AggClauseCosts *agg_costs, double numGroups)
Definition: pathnode.c:3040
BMS_Comparison
Definition: bitmapset.h:57
double Cost
Definition: nodes.h:663
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:241
#define foreach_current_index(cell)
Definition: pg_list.h:381
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:94
Relids top_parent_relids
Definition: pathnodes.h:738
static MemoryContext GetMemoryChunkContext(void *pointer)
Definition: memutils.h:113
void final_cost_mergejoin(PlannerInfo *root, MergePath *path, JoinCostWorkspace *workspace, JoinPathExtraData *extra)
Definition: costsize.c:3151
List * gsets
Definition: pathnodes.h:1723
static int cmp(const chr *x, const chr *y, size_t len)
Definition: regc_locale.c:742
Path * subpath
Definition: pathnodes.h:1481
BitmapHeapPath * create_bitmap_heap_path(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual, Relids required_outer, double loop_count, int parallel_degree)
Definition: pathnode.c:1046
Path * create_namedtuplestorescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2015
Definition: nodes.h:87
ReparameterizeForeignPathByChild_function ReparameterizeForeignPathByChild
Definition: fdwapi.h:248
Path * create_ctescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1990