Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * pathnode.c
4 : * Routines to manipulate pathlists and create path nodes
5 : *
6 : * Portions Copyright (c) 1996-2019, 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 "miscadmin.h"
20 : #include "foreign/fdwapi.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 :
39 : typedef enum
40 : {
41 : COSTS_EQUAL, /* path costs are fuzzily equal */
42 : COSTS_BETTER1, /* first path is cheaper than second */
43 : COSTS_BETTER2, /* second path is cheaper than first */
44 : COSTS_DIFFERENT /* neither path dominates the other on cost */
45 : } PathCostComparison;
46 :
47 : /*
48 : * STD_FUZZ_FACTOR is the normal fuzz factor for compare_path_costs_fuzzily.
49 : * XXX is it worth making this user-controllable? It provides a tradeoff
50 : * between planner runtime and the accuracy of path cost comparisons.
51 : */
52 : #define STD_FUZZ_FACTOR 1.01
53 :
54 : static List *translate_sub_tlist(List *tlist, int relid);
55 : static int append_total_cost_compare(const void *a, const void *b);
56 : static int append_startup_cost_compare(const void *a, const void *b);
57 : static List *reparameterize_pathlist_by_child(PlannerInfo *root,
58 : List *pathlist,
59 : RelOptInfo *child_rel);
60 :
61 :
62 : /*****************************************************************************
63 : * MISC. PATH UTILITIES
64 : *****************************************************************************/
65 :
66 : /*
67 : * compare_path_costs
68 : * Return -1, 0, or +1 according as path1 is cheaper, the same cost,
69 : * or more expensive than path2 for the specified criterion.
70 : */
71 : int
72 383652 : compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
73 : {
74 383652 : if (criterion == STARTUP_COST)
75 : {
76 196362 : if (path1->startup_cost < path2->startup_cost)
77 96058 : return -1;
78 100304 : if (path1->startup_cost > path2->startup_cost)
79 43328 : return +1;
80 :
81 : /*
82 : * If paths have the same startup cost (not at all unlikely), order
83 : * them by total cost.
84 : */
85 56976 : if (path1->total_cost < path2->total_cost)
86 35728 : return -1;
87 21248 : if (path1->total_cost > path2->total_cost)
88 1496 : return +1;
89 : }
90 : else
91 : {
92 187290 : if (path1->total_cost < path2->total_cost)
93 179686 : return -1;
94 7604 : if (path1->total_cost > path2->total_cost)
95 1522 : return +1;
96 :
97 : /*
98 : * If paths have the same total cost, order them by startup cost.
99 : */
100 6082 : if (path1->startup_cost < path2->startup_cost)
101 8 : return -1;
102 6074 : if (path1->startup_cost > path2->startup_cost)
103 0 : return +1;
104 : }
105 25826 : return 0;
106 : }
107 :
108 : /*
109 : * compare_path_fractional_costs
110 : * Return -1, 0, or +1 according as path1 is cheaper, the same cost,
111 : * or more expensive than path2 for fetching the specified fraction
112 : * of the total tuples.
113 : *
114 : * If fraction is <= 0 or > 1, we interpret it as 1, ie, we select the
115 : * path with the cheaper total_cost.
116 : */
117 : int
118 2246 : compare_fractional_path_costs(Path *path1, Path *path2,
119 : double fraction)
120 : {
121 : Cost cost1,
122 : cost2;
123 :
124 2246 : if (fraction <= 0.0 || fraction >= 1.0)
125 1034 : return compare_path_costs(path1, path2, TOTAL_COST);
126 2424 : cost1 = path1->startup_cost +
127 1212 : fraction * (path1->total_cost - path1->startup_cost);
128 2424 : cost2 = path2->startup_cost +
129 1212 : fraction * (path2->total_cost - path2->startup_cost);
130 1212 : if (cost1 < cost2)
131 630 : return -1;
132 582 : if (cost1 > cost2)
133 582 : return +1;
134 0 : return 0;
135 : }
136 :
137 : /*
138 : * compare_path_costs_fuzzily
139 : * Compare the costs of two paths to see if either can be said to
140 : * dominate the other.
141 : *
142 : * We use fuzzy comparisons so that add_path() can avoid keeping both of
143 : * a pair of paths that really have insignificantly different cost.
144 : *
145 : * The fuzz_factor argument must be 1.0 plus delta, where delta is the
146 : * fraction of the smaller cost that is considered to be a significant
147 : * difference. For example, fuzz_factor = 1.01 makes the fuzziness limit
148 : * be 1% of the smaller cost.
149 : *
150 : * The two paths are said to have "equal" costs if both startup and total
151 : * costs are fuzzily the same. Path1 is said to be better than path2 if
152 : * it has fuzzily better startup cost and fuzzily no worse total cost,
153 : * or if it has fuzzily better total cost and fuzzily no worse startup cost.
154 : * Path2 is better than path1 if the reverse holds. Finally, if one path
155 : * is fuzzily better than the other on startup cost and fuzzily worse on
156 : * total cost, we just say that their costs are "different", since neither
157 : * dominates the other across the whole performance spectrum.
158 : *
159 : * This function also enforces a policy rule that paths for which the relevant
160 : * one of parent->consider_startup and parent->consider_param_startup is false
161 : * cannot survive comparisons solely on the grounds of good startup cost, so
162 : * we never return COSTS_DIFFERENT when that is true for the total-cost loser.
163 : * (But if total costs are fuzzily equal, we compare startup costs anyway,
164 : * in hopes of eliminating one path or the other.)
165 : */
166 : static PathCostComparison
167 1703358 : compare_path_costs_fuzzily(Path *path1, Path *path2, double fuzz_factor)
168 : {
169 : #define CONSIDER_PATH_STARTUP_COST(p) \
170 : ((p)->param_info == NULL ? (p)->parent->consider_startup : (p)->parent->consider_param_startup)
171 :
172 : /*
173 : * Check total cost first since it's more likely to be different; many
174 : * paths have zero startup cost.
175 : */
176 1703358 : if (path1->total_cost > path2->total_cost * fuzz_factor)
177 : {
178 : /* path1 fuzzily worse on total cost */
179 835214 : if (CONSIDER_PATH_STARTUP_COST(path1) &&
180 27210 : path2->startup_cost > path1->startup_cost * fuzz_factor)
181 : {
182 : /* ... but path2 fuzzily worse on startup, so DIFFERENT */
183 13116 : return COSTS_DIFFERENT;
184 : }
185 : /* else path2 dominates */
186 794888 : return COSTS_BETTER2;
187 : }
188 895354 : if (path2->total_cost > path1->total_cost * fuzz_factor)
189 : {
190 : /* path2 fuzzily worse on total cost */
191 464534 : if (CONSIDER_PATH_STARTUP_COST(path2) &&
192 11664 : path1->startup_cost > path2->startup_cost * fuzz_factor)
193 : {
194 : /* ... but path1 fuzzily worse on startup, so DIFFERENT */
195 6348 : return COSTS_DIFFERENT;
196 : }
197 : /* else path1 dominates */
198 446522 : return COSTS_BETTER1;
199 : }
200 : /* fuzzily the same on total cost ... */
201 442484 : if (path1->startup_cost > path2->startup_cost * fuzz_factor)
202 : {
203 : /* ... but path1 fuzzily worse on startup, so path2 wins */
204 174432 : return COSTS_BETTER2;
205 : }
206 268052 : if (path2->startup_cost > path1->startup_cost * fuzz_factor)
207 : {
208 : /* ... but path2 fuzzily worse on startup, so path1 wins */
209 36552 : return COSTS_BETTER1;
210 : }
211 : /* fuzzily the same on both costs */
212 231500 : return COSTS_EQUAL;
213 :
214 : #undef CONSIDER_PATH_STARTUP_COST
215 : }
216 :
217 : /*
218 : * set_cheapest
219 : * Find the minimum-cost paths from among a relation's paths,
220 : * and save them in the rel's cheapest-path fields.
221 : *
222 : * cheapest_total_path is normally the cheapest-total-cost unparameterized
223 : * path; but if there are no unparameterized paths, we assign it to be the
224 : * best (cheapest least-parameterized) parameterized path. However, only
225 : * unparameterized paths are considered candidates for cheapest_startup_path,
226 : * so that will be NULL if there are no unparameterized paths.
227 : *
228 : * The cheapest_parameterized_paths list collects all parameterized paths
229 : * that have survived the add_path() tournament for this relation. (Since
230 : * add_path ignores pathkeys for a parameterized path, these will be paths
231 : * that have best cost or best row count for their parameterization. We
232 : * may also have both a parallel-safe and a non-parallel-safe path in some
233 : * cases for the same parameterization in some cases, but this should be
234 : * relatively rare since, most typically, all paths for the same relation
235 : * will be parallel-safe or none of them will.)
236 : *
237 : * cheapest_parameterized_paths always includes the cheapest-total
238 : * unparameterized path, too, if there is one; the users of that list find
239 : * it more convenient if that's included.
240 : *
241 : * This is normally called only after we've finished constructing the path
242 : * list for the rel node.
243 : */
244 : void
245 1108192 : set_cheapest(RelOptInfo *parent_rel)
246 : {
247 : Path *cheapest_startup_path;
248 : Path *cheapest_total_path;
249 : Path *best_param_path;
250 : List *parameterized_paths;
251 : ListCell *p;
252 :
253 : Assert(IsA(parent_rel, RelOptInfo));
254 :
255 1108192 : if (parent_rel->pathlist == NIL)
256 0 : elog(ERROR, "could not devise a query plan for the given query");
257 :
258 1108192 : cheapest_startup_path = cheapest_total_path = best_param_path = NULL;
259 1108192 : parameterized_paths = NIL;
260 :
261 2422004 : foreach(p, parent_rel->pathlist)
262 : {
263 1313812 : Path *path = (Path *) lfirst(p);
264 : int cmp;
265 :
266 1313812 : if (path->param_info)
267 : {
268 : /* Parameterized path, so add it to parameterized_paths */
269 57986 : parameterized_paths = lappend(parameterized_paths, path);
270 :
271 : /*
272 : * If we have an unparameterized cheapest-total, we no longer care
273 : * about finding the best parameterized path, so move on.
274 : */
275 57986 : if (cheapest_total_path)
276 7794 : continue;
277 :
278 : /*
279 : * Otherwise, track the best parameterized path, which is the one
280 : * with least total cost among those of the minimum
281 : * parameterization.
282 : */
283 50192 : if (best_param_path == NULL)
284 47068 : best_param_path = path;
285 : else
286 : {
287 6248 : switch (bms_subset_compare(PATH_REQ_OUTER(path),
288 6248 : PATH_REQ_OUTER(best_param_path)))
289 : {
290 : case BMS_EQUAL:
291 : /* keep the cheaper one */
292 36 : if (compare_path_costs(path, best_param_path,
293 : TOTAL_COST) < 0)
294 0 : best_param_path = path;
295 36 : break;
296 : case BMS_SUBSET1:
297 : /* new path is less-parameterized */
298 138 : best_param_path = path;
299 138 : break;
300 : case BMS_SUBSET2:
301 : /* old path is less-parameterized, keep it */
302 8 : break;
303 : case BMS_DIFFERENT:
304 :
305 : /*
306 : * This means that neither path has the least possible
307 : * parameterization for the rel. We'll sit on the old
308 : * path until something better comes along.
309 : */
310 2942 : break;
311 : }
312 : }
313 : }
314 : else
315 : {
316 : /* Unparameterized path, so consider it for cheapest slots */
317 1255826 : if (cheapest_total_path == NULL)
318 : {
319 1106760 : cheapest_startup_path = cheapest_total_path = path;
320 1106760 : continue;
321 : }
322 :
323 : /*
324 : * If we find two paths of identical costs, try to keep the
325 : * better-sorted one. The paths might have unrelated sort
326 : * orderings, in which case we can only guess which might be
327 : * better to keep, but if one is superior then we definitely
328 : * should keep that one.
329 : */
330 149066 : cmp = compare_path_costs(cheapest_startup_path, path, STARTUP_COST);
331 149066 : if (cmp > 0 ||
332 66 : (cmp == 0 &&
333 66 : compare_pathkeys(cheapest_startup_path->pathkeys,
334 : path->pathkeys) == PATHKEYS_BETTER2))
335 35764 : cheapest_startup_path = path;
336 :
337 149066 : cmp = compare_path_costs(cheapest_total_path, path, TOTAL_COST);
338 149066 : if (cmp > 0 ||
339 0 : (cmp == 0 &&
340 0 : compare_pathkeys(cheapest_total_path->pathkeys,
341 : path->pathkeys) == PATHKEYS_BETTER2))
342 0 : cheapest_total_path = path;
343 : }
344 : }
345 :
346 : /* Add cheapest unparameterized path, if any, to parameterized_paths */
347 1108192 : if (cheapest_total_path)
348 1106760 : parameterized_paths = lcons(cheapest_total_path, parameterized_paths);
349 :
350 : /*
351 : * If there is no unparameterized path, use the best parameterized path as
352 : * cheapest_total_path (but not as cheapest_startup_path).
353 : */
354 1108192 : if (cheapest_total_path == NULL)
355 1432 : cheapest_total_path = best_param_path;
356 : Assert(cheapest_total_path != NULL);
357 :
358 1108192 : parent_rel->cheapest_startup_path = cheapest_startup_path;
359 1108192 : parent_rel->cheapest_total_path = cheapest_total_path;
360 1108192 : parent_rel->cheapest_unique_path = NULL; /* computed only if needed */
361 1108192 : parent_rel->cheapest_parameterized_paths = parameterized_paths;
362 1108192 : }
363 :
364 : /*
365 : * add_path
366 : * Consider a potential implementation path for the specified parent rel,
367 : * and add it to the rel's pathlist if it is worthy of consideration.
368 : * A path is worthy if it has a better sort order (better pathkeys) or
369 : * cheaper cost (on either dimension), or generates fewer rows, than any
370 : * existing path that has the same or superset parameterization rels.
371 : * We also consider parallel-safe paths more worthy than others.
372 : *
373 : * We also remove from the rel's pathlist any old paths that are dominated
374 : * by new_path --- that is, new_path is cheaper, at least as well ordered,
375 : * generates no more rows, requires no outer rels not required by the old
376 : * path, and is no less parallel-safe.
377 : *
378 : * In most cases, a path with a superset parameterization will generate
379 : * fewer rows (since it has more join clauses to apply), so that those two
380 : * figures of merit move in opposite directions; this means that a path of
381 : * one parameterization can seldom dominate a path of another. But such
382 : * cases do arise, so we make the full set of checks anyway.
383 : *
384 : * There are two policy decisions embedded in this function, along with
385 : * its sibling add_path_precheck. First, we treat all parameterized paths
386 : * as having NIL pathkeys, so that they cannot win comparisons on the
387 : * basis of sort order. This is to reduce the number of parameterized
388 : * paths that are kept; see discussion in src/backend/optimizer/README.
389 : *
390 : * Second, we only consider cheap startup cost to be interesting if
391 : * parent_rel->consider_startup is true for an unparameterized path, or
392 : * parent_rel->consider_param_startup is true for a parameterized one.
393 : * Again, this allows discarding useless paths sooner.
394 : *
395 : * The pathlist is kept sorted by total_cost, with cheaper paths
396 : * at the front. Within this routine, that's simply a speed hack:
397 : * doing it that way makes it more likely that we will reject an inferior
398 : * path after a few comparisons, rather than many comparisons.
399 : * However, add_path_precheck relies on this ordering to exit early
400 : * when possible.
401 : *
402 : * NOTE: discarded Path objects are immediately pfree'd to reduce planner
403 : * memory consumption. We dare not try to free the substructure of a Path,
404 : * since much of it may be shared with other Paths or the query tree itself;
405 : * but just recycling discarded Path nodes is a very useful savings in
406 : * a large join tree. We can recycle the List nodes of pathlist, too.
407 : *
408 : * As noted in optimizer/README, deleting a previously-accepted Path is
409 : * safe because we know that Paths of this rel cannot yet be referenced
410 : * from any other rel, such as a higher-level join. However, in some cases
411 : * it is possible that a Path is referenced by another Path for its own
412 : * rel; we must not delete such a Path, even if it is dominated by the new
413 : * Path. Currently this occurs only for IndexPath objects, which may be
414 : * referenced as children of BitmapHeapPaths as well as being paths in
415 : * their own right. Hence, we don't pfree IndexPaths when rejecting them.
416 : *
417 : * 'parent_rel' is the relation entry to which the path corresponds.
418 : * 'new_path' is a potential path for parent_rel.
419 : *
420 : * Returns nothing, but modifies parent_rel->pathlist.
421 : */
422 : void
423 2009920 : add_path(RelOptInfo *parent_rel, Path *new_path)
424 : {
425 2009920 : bool accept_new = true; /* unless we find a superior old path */
426 2009920 : ListCell *insert_after = NULL; /* where to insert new item */
427 : List *new_path_pathkeys;
428 : ListCell *p1;
429 : ListCell *p1_prev;
430 : ListCell *p1_next;
431 :
432 : /*
433 : * This is a convenient place to check for query cancel --- no part of the
434 : * planner goes very long without calling add_path().
435 : */
436 2009920 : CHECK_FOR_INTERRUPTS();
437 :
438 : /* Pretend parameterized paths have no pathkeys, per comment above */
439 2009920 : new_path_pathkeys = new_path->param_info ? NIL : new_path->pathkeys;
440 :
441 : /*
442 : * Loop to check proposed new path against old paths. Note it is possible
443 : * for more than one old path to be tossed out because new_path dominates
444 : * it.
445 : *
446 : * We can't use foreach here because the loop body may delete the current
447 : * list cell.
448 : */
449 2009920 : p1_prev = NULL;
450 2858882 : for (p1 = list_head(parent_rel->pathlist); p1 != NULL; p1 = p1_next)
451 : {
452 1543968 : Path *old_path = (Path *) lfirst(p1);
453 1543968 : bool remove_old = false; /* unless new proves superior */
454 : PathCostComparison costcmp;
455 : PathKeysComparison keyscmp;
456 : BMS_Comparison outercmp;
457 :
458 1543968 : p1_next = lnext(p1);
459 :
460 : /*
461 : * Do a fuzzy cost comparison with standard fuzziness limit.
462 : */
463 1543968 : costcmp = compare_path_costs_fuzzily(new_path, old_path,
464 : STD_FUZZ_FACTOR);
465 :
466 : /*
467 : * If the two paths compare differently for startup and total cost,
468 : * then we want to keep both, and we can skip comparing pathkeys and
469 : * required_outer rels. If they compare the same, proceed with the
470 : * other comparisons. Row count is checked last. (We make the tests
471 : * in this order because the cost comparison is most likely to turn
472 : * out "different", and the pathkeys comparison next most likely. As
473 : * explained above, row count very seldom makes a difference, so even
474 : * though it's cheap to compare there's not much point in checking it
475 : * earlier.)
476 : */
477 1543968 : if (costcmp != COSTS_DIFFERENT)
478 : {
479 : /* Similarly check to see if either dominates on pathkeys */
480 : List *old_path_pathkeys;
481 :
482 1524514 : old_path_pathkeys = old_path->param_info ? NIL : old_path->pathkeys;
483 1524514 : keyscmp = compare_pathkeys(new_path_pathkeys,
484 : old_path_pathkeys);
485 1524514 : if (keyscmp != PATHKEYS_DIFFERENT)
486 : {
487 1472808 : switch (costcmp)
488 : {
489 : case COSTS_EQUAL:
490 167814 : outercmp = bms_subset_compare(PATH_REQ_OUTER(new_path),
491 167814 : PATH_REQ_OUTER(old_path));
492 166734 : if (keyscmp == PATHKEYS_BETTER1)
493 : {
494 920 : if ((outercmp == BMS_EQUAL ||
495 920 : outercmp == BMS_SUBSET1) &&
496 1836 : new_path->rows <= old_path->rows &&
497 916 : new_path->parallel_safe >= old_path->parallel_safe)
498 916 : remove_old = true; /* new dominates old */
499 : }
500 165814 : else if (keyscmp == PATHKEYS_BETTER2)
501 : {
502 5370 : if ((outercmp == BMS_EQUAL ||
503 5370 : outercmp == BMS_SUBSET2) &&
504 10740 : new_path->rows >= old_path->rows &&
505 5370 : new_path->parallel_safe <= old_path->parallel_safe)
506 5370 : accept_new = false; /* old dominates new */
507 : }
508 : else /* keyscmp == PATHKEYS_EQUAL */
509 : {
510 160444 : if (outercmp == BMS_EQUAL)
511 : {
512 : /*
513 : * Same pathkeys and outer rels, and fuzzily
514 : * the same cost, so keep just one; to decide
515 : * which, first check parallel-safety, then
516 : * rows, then do a fuzzy cost comparison with
517 : * very small fuzz limit. (We used to do an
518 : * exact cost comparison, but that results in
519 : * annoying platform-specific plan variations
520 : * due to roundoff in the cost estimates.) If
521 : * things are still tied, arbitrarily keep
522 : * only the old path. Notice that we will
523 : * keep only the old path even if the
524 : * less-fuzzy comparison decides the startup
525 : * and total costs compare differently.
526 : */
527 319012 : if (new_path->parallel_safe >
528 159506 : old_path->parallel_safe)
529 32 : remove_old = true; /* new dominates old */
530 318948 : else if (new_path->parallel_safe <
531 159474 : old_path->parallel_safe)
532 68 : accept_new = false; /* old dominates new */
533 159406 : else if (new_path->rows < old_path->rows)
534 4 : remove_old = true; /* new dominates old */
535 159402 : else if (new_path->rows > old_path->rows)
536 12 : accept_new = false; /* old dominates new */
537 159390 : else if (compare_path_costs_fuzzily(new_path,
538 : old_path,
539 : 1.0000000001) == COSTS_BETTER1)
540 5338 : remove_old = true; /* new dominates old */
541 : else
542 154052 : accept_new = false; /* old equals or
543 : * dominates new */
544 : }
545 1120 : else if (outercmp == BMS_SUBSET1 &&
546 360 : new_path->rows <= old_path->rows &&
547 178 : new_path->parallel_safe >= old_path->parallel_safe)
548 178 : remove_old = true; /* new dominates old */
549 1414 : else if (outercmp == BMS_SUBSET2 &&
550 1294 : new_path->rows >= old_path->rows &&
551 640 : new_path->parallel_safe <= old_path->parallel_safe)
552 640 : accept_new = false; /* old dominates new */
553 : /* else different parameterizations, keep both */
554 : }
555 166734 : break;
556 : case COSTS_BETTER1:
557 468426 : if (keyscmp != PATHKEYS_BETTER2)
558 : {
559 330554 : outercmp = bms_subset_compare(PATH_REQ_OUTER(new_path),
560 330554 : PATH_REQ_OUTER(old_path));
561 323918 : if ((outercmp == BMS_EQUAL ||
562 278268 : outercmp == BMS_SUBSET1) &&
563 555288 : new_path->rows <= old_path->rows &&
564 277020 : new_path->parallel_safe >= old_path->parallel_safe)
565 275588 : remove_old = true; /* new dominates old */
566 : }
567 468426 : break;
568 : case COSTS_BETTER2:
569 837648 : if (keyscmp != PATHKEYS_BETTER1)
570 : {
571 669116 : outercmp = bms_subset_compare(PATH_REQ_OUTER(new_path),
572 669116 : PATH_REQ_OUTER(old_path));
573 585166 : if ((outercmp == BMS_EQUAL ||
574 556322 : outercmp == BMS_SUBSET2) &&
575 1092722 : new_path->rows >= old_path->rows &&
576 536400 : new_path->parallel_safe <= old_path->parallel_safe)
577 534864 : accept_new = false; /* old dominates new */
578 : }
579 837648 : break;
580 : case COSTS_DIFFERENT:
581 :
582 : /*
583 : * can't get here, but keep this case to keep compiler
584 : * quiet
585 : */
586 0 : break;
587 : }
588 : }
589 : }
590 :
591 : /*
592 : * Remove current element from pathlist if dominated by new.
593 : */
594 1543968 : if (remove_old)
595 : {
596 282056 : parent_rel->pathlist = list_delete_cell(parent_rel->pathlist,
597 : p1, p1_prev);
598 :
599 : /*
600 : * Delete the data pointed-to by the deleted cell, if possible
601 : */
602 282056 : if (!IsA(old_path, IndexPath))
603 269214 : pfree(old_path);
604 : /* p1_prev does not advance */
605 : }
606 : else
607 : {
608 : /* new belongs after this old path if it has cost >= old's */
609 1261912 : if (new_path->total_cost >= old_path->total_cost)
610 1014070 : insert_after = p1;
611 : /* p1_prev advances */
612 1261912 : p1_prev = p1;
613 : }
614 :
615 : /*
616 : * If we found an old path that dominates new_path, we can quit
617 : * scanning the pathlist; we will not add new_path, and we assume
618 : * new_path cannot dominate any other elements of the pathlist.
619 : */
620 1543968 : if (!accept_new)
621 695006 : break;
622 : }
623 :
624 2009920 : if (accept_new)
625 : {
626 : /* Accept the new path: insert it at proper place in pathlist */
627 1314914 : if (insert_after)
628 175704 : lappend_cell(parent_rel->pathlist, insert_after, new_path);
629 : else
630 1139210 : parent_rel->pathlist = lcons(new_path, parent_rel->pathlist);
631 : }
632 : else
633 : {
634 : /* Reject and recycle the new path */
635 695006 : if (!IsA(new_path, IndexPath))
636 645516 : pfree(new_path);
637 : }
638 2009920 : }
639 :
640 : /*
641 : * add_path_precheck
642 : * Check whether a proposed new path could possibly get accepted.
643 : * We assume we know the path's pathkeys and parameterization accurately,
644 : * and have lower bounds for its costs.
645 : *
646 : * Note that we do not know the path's rowcount, since getting an estimate for
647 : * that is too expensive to do before prechecking. We assume here that paths
648 : * of a superset parameterization will generate fewer rows; if that holds,
649 : * then paths with different parameterizations cannot dominate each other
650 : * and so we can simply ignore existing paths of another parameterization.
651 : * (In the infrequent cases where that rule of thumb fails, add_path will
652 : * get rid of the inferior path.)
653 : *
654 : * At the time this is called, we haven't actually built a Path structure,
655 : * so the required information has to be passed piecemeal.
656 : */
657 : bool
658 1739926 : add_path_precheck(RelOptInfo *parent_rel,
659 : Cost startup_cost, Cost total_cost,
660 : List *pathkeys, Relids required_outer)
661 : {
662 : List *new_path_pathkeys;
663 : bool consider_startup;
664 : ListCell *p1;
665 :
666 : /* Pretend parameterized paths have no pathkeys, per add_path policy */
667 1739926 : new_path_pathkeys = required_outer ? NIL : pathkeys;
668 :
669 : /* Decide whether new path's startup cost is interesting */
670 1739926 : consider_startup = required_outer ? parent_rel->consider_param_startup : parent_rel->consider_startup;
671 :
672 2154868 : foreach(p1, parent_rel->pathlist)
673 : {
674 2033776 : Path *old_path = (Path *) lfirst(p1);
675 : PathKeysComparison keyscmp;
676 :
677 : /*
678 : * We are looking for an old_path with the same parameterization (and
679 : * by assumption the same rowcount) that dominates the new path on
680 : * pathkeys as well as both cost metrics. If we find one, we can
681 : * reject the new path.
682 : *
683 : * Cost comparisons here should match compare_path_costs_fuzzily.
684 : */
685 2033776 : if (total_cost > old_path->total_cost * STD_FUZZ_FACTOR)
686 : {
687 : /* new path can win on startup cost only if consider_startup */
688 2018466 : if (startup_cost > old_path->startup_cost * STD_FUZZ_FACTOR ||
689 679914 : !consider_startup)
690 : {
691 : /* new path loses on cost, so check pathkeys... */
692 : List *old_path_pathkeys;
693 :
694 1327596 : old_path_pathkeys = old_path->param_info ? NIL : old_path->pathkeys;
695 1327596 : keyscmp = compare_pathkeys(new_path_pathkeys,
696 : old_path_pathkeys);
697 1327596 : if (keyscmp == PATHKEYS_EQUAL ||
698 : keyscmp == PATHKEYS_BETTER2)
699 : {
700 : /* new path does not win on pathkeys... */
701 935032 : if (bms_equal(required_outer, PATH_REQ_OUTER(old_path)))
702 : {
703 : /* Found an old path that dominates the new one */
704 923610 : return false;
705 : }
706 : }
707 : }
708 : }
709 : else
710 : {
711 : /*
712 : * Since the pathlist is sorted by total_cost, we can stop looking
713 : * once we reach a path with a total_cost larger than the new
714 : * path's.
715 : */
716 695224 : break;
717 : }
718 : }
719 :
720 816316 : return true;
721 : }
722 :
723 : /*
724 : * add_partial_path
725 : * Like add_path, our goal here is to consider whether a path is worthy
726 : * of being kept around, but the considerations here are a bit different.
727 : * A partial path is one which can be executed in any number of workers in
728 : * parallel such that each worker will generate a subset of the path's
729 : * overall result.
730 : *
731 : * As in add_path, the partial_pathlist is kept sorted with the cheapest
732 : * total path in front. This is depended on by multiple places, which
733 : * just take the front entry as the cheapest path without searching.
734 : *
735 : * We don't generate parameterized partial paths for several reasons. Most
736 : * importantly, they're not safe to execute, because there's nothing to
737 : * make sure that a parallel scan within the parameterized portion of the
738 : * plan is running with the same value in every worker at the same time.
739 : * Fortunately, it seems unlikely to be worthwhile anyway, because having
740 : * each worker scan the entire outer relation and a subset of the inner
741 : * relation will generally be a terrible plan. The inner (parameterized)
742 : * side of the plan will be small anyway. There could be rare cases where
743 : * this wins big - e.g. if join order constraints put a 1-row relation on
744 : * the outer side of the topmost join with a parameterized plan on the inner
745 : * side - but we'll have to be content not to handle such cases until
746 : * somebody builds an executor infrastructure that can cope with them.
747 : *
748 : * Because we don't consider parameterized paths here, we also don't
749 : * need to consider the row counts as a measure of quality: every path will
750 : * produce the same number of rows. Neither do we need to consider startup
751 : * costs: parallelism is only used for plans that will be run to completion.
752 : * Therefore, this routine is much simpler than add_path: it needs to
753 : * consider only pathkeys and total cost.
754 : *
755 : * As with add_path, we pfree paths that are found to be dominated by
756 : * another partial path; this requires that there be no other references to
757 : * such paths yet. Hence, GatherPaths must not be created for a rel until
758 : * we're done creating all partial paths for it. Unlike add_path, we don't
759 : * take an exception for IndexPaths as partial index paths won't be
760 : * referenced by partial BitmapHeapPaths.
761 : */
762 : void
763 33916 : add_partial_path(RelOptInfo *parent_rel, Path *new_path)
764 : {
765 33916 : bool accept_new = true; /* unless we find a superior old path */
766 33916 : ListCell *insert_after = NULL; /* where to insert new item */
767 : ListCell *p1;
768 : ListCell *p1_prev;
769 : ListCell *p1_next;
770 :
771 : /* Check for query cancel. */
772 33916 : CHECK_FOR_INTERRUPTS();
773 :
774 : /* Path to be added must be parallel safe. */
775 : Assert(new_path->parallel_safe);
776 :
777 : /* Relation should be OK for parallelism, too. */
778 : Assert(parent_rel->consider_parallel);
779 :
780 : /*
781 : * As in add_path, throw out any paths which are dominated by the new
782 : * path, but throw out the new path if some existing path dominates it.
783 : */
784 33916 : p1_prev = NULL;
785 75818 : for (p1 = list_head(parent_rel->partial_pathlist); p1 != NULL;
786 7986 : p1 = p1_next)
787 : {
788 11502 : Path *old_path = (Path *) lfirst(p1);
789 11502 : bool remove_old = false; /* unless new proves superior */
790 : PathKeysComparison keyscmp;
791 :
792 11502 : p1_next = lnext(p1);
793 :
794 : /* Compare pathkeys. */
795 11502 : keyscmp = compare_pathkeys(new_path->pathkeys, old_path->pathkeys);
796 :
797 : /* Unless pathkeys are incompable, keep just one of the two paths. */
798 11502 : if (keyscmp != PATHKEYS_DIFFERENT)
799 : {
800 11502 : if (new_path->total_cost > old_path->total_cost * STD_FUZZ_FACTOR)
801 : {
802 : /* New path costs more; keep it only if pathkeys are better. */
803 5710 : if (keyscmp != PATHKEYS_BETTER1)
804 2690 : accept_new = false;
805 : }
806 11584 : else if (old_path->total_cost > new_path->total_cost
807 5792 : * STD_FUZZ_FACTOR)
808 : {
809 : /* Old path costs more; keep it only if pathkeys are better. */
810 4798 : if (keyscmp != PATHKEYS_BETTER2)
811 2628 : remove_old = true;
812 : }
813 994 : else if (keyscmp == PATHKEYS_BETTER1)
814 : {
815 : /* Costs are about the same, new path has better pathkeys. */
816 0 : remove_old = true;
817 : }
818 994 : else if (keyscmp == PATHKEYS_BETTER2)
819 : {
820 : /* Costs are about the same, old path has better pathkeys. */
821 112 : accept_new = false;
822 : }
823 882 : else if (old_path->total_cost > new_path->total_cost * 1.0000000001)
824 : {
825 : /* Pathkeys are the same, and the old path costs more. */
826 168 : remove_old = true;
827 : }
828 : else
829 : {
830 : /*
831 : * Pathkeys are the same, and new path isn't materially
832 : * cheaper.
833 : */
834 714 : accept_new = false;
835 : }
836 : }
837 :
838 : /*
839 : * Remove current element from partial_pathlist if dominated by new.
840 : */
841 11502 : if (remove_old)
842 : {
843 2796 : parent_rel->partial_pathlist =
844 2796 : list_delete_cell(parent_rel->partial_pathlist, p1, p1_prev);
845 2796 : pfree(old_path);
846 : /* p1_prev does not advance */
847 : }
848 : else
849 : {
850 : /* new belongs after this old path if it has cost >= old's */
851 8706 : if (new_path->total_cost >= old_path->total_cost)
852 6496 : insert_after = p1;
853 : /* p1_prev advances */
854 8706 : p1_prev = p1;
855 : }
856 :
857 : /*
858 : * If we found an old path that dominates new_path, we can quit
859 : * scanning the partial_pathlist; we will not add new_path, and we
860 : * assume new_path cannot dominate any later path.
861 : */
862 11502 : if (!accept_new)
863 3516 : break;
864 : }
865 :
866 33916 : if (accept_new)
867 : {
868 : /* Accept the new path: insert it at proper place */
869 30400 : if (insert_after)
870 2724 : lappend_cell(parent_rel->partial_pathlist, insert_after, new_path);
871 : else
872 27676 : parent_rel->partial_pathlist =
873 27676 : lcons(new_path, parent_rel->partial_pathlist);
874 : }
875 : else
876 : {
877 : /* Reject and recycle the new path */
878 3516 : pfree(new_path);
879 : }
880 33916 : }
881 :
882 : /*
883 : * add_partial_path_precheck
884 : * Check whether a proposed new partial path could possibly get accepted.
885 : *
886 : * Unlike add_path_precheck, we can ignore startup cost and parameterization,
887 : * since they don't matter for partial paths (see add_partial_path). But
888 : * we do want to make sure we don't add a partial path if there's already
889 : * a complete path that dominates it, since in that case the proposed path
890 : * is surely a loser.
891 : */
892 : bool
893 19204 : add_partial_path_precheck(RelOptInfo *parent_rel, Cost total_cost,
894 : List *pathkeys)
895 : {
896 : ListCell *p1;
897 :
898 : /*
899 : * Our goal here is twofold. First, we want to find out whether this path
900 : * is clearly inferior to some existing partial path. If so, we want to
901 : * reject it immediately. Second, we want to find out whether this path
902 : * is clearly superior to some existing partial path -- at least, modulo
903 : * final cost computations. If so, we definitely want to consider it.
904 : *
905 : * Unlike add_path(), we always compare pathkeys here. This is because we
906 : * expect partial_pathlist to be very short, and getting a definitive
907 : * answer at this stage avoids the need to call add_path_precheck.
908 : */
909 24254 : foreach(p1, parent_rel->partial_pathlist)
910 : {
911 20412 : Path *old_path = (Path *) lfirst(p1);
912 : PathKeysComparison keyscmp;
913 :
914 20412 : keyscmp = compare_pathkeys(pathkeys, old_path->pathkeys);
915 20412 : if (keyscmp != PATHKEYS_DIFFERENT)
916 : {
917 20412 : if (total_cost > old_path->total_cost * STD_FUZZ_FACTOR &&
918 : keyscmp != PATHKEYS_BETTER1)
919 12458 : return false;
920 7954 : if (old_path->total_cost > total_cost * STD_FUZZ_FACTOR &&
921 : keyscmp != PATHKEYS_BETTER2)
922 2904 : return true;
923 : }
924 : }
925 :
926 : /*
927 : * This path is neither clearly inferior to an existing partial path nor
928 : * clearly good enough that it might replace one. Compare it to
929 : * non-parallel plans. If it loses even before accounting for the cost of
930 : * the Gather node, we should definitely reject it.
931 : *
932 : * Note that we pass the total_cost to add_path_precheck twice. This is
933 : * because it's never advantageous to consider the startup cost of a
934 : * partial path; the resulting plans, if run in parallel, will be run to
935 : * completion.
936 : */
937 3842 : if (!add_path_precheck(parent_rel, total_cost, total_cost, pathkeys,
938 : NULL))
939 240 : return false;
940 :
941 3602 : return true;
942 : }
943 :
944 :
945 : /*****************************************************************************
946 : * PATH NODE CREATION ROUTINES
947 : *****************************************************************************/
948 :
949 : /*
950 : * create_seqscan_path
951 : * Creates a path corresponding to a sequential scan, returning the
952 : * pathnode.
953 : */
954 : Path *
955 228696 : create_seqscan_path(PlannerInfo *root, RelOptInfo *rel,
956 : Relids required_outer, int parallel_workers)
957 : {
958 228696 : Path *pathnode = makeNode(Path);
959 :
960 228696 : pathnode->pathtype = T_SeqScan;
961 228696 : pathnode->parent = rel;
962 228696 : pathnode->pathtarget = rel->reltarget;
963 228696 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
964 : required_outer);
965 228696 : pathnode->parallel_aware = parallel_workers > 0 ? true : false;
966 228696 : pathnode->parallel_safe = rel->consider_parallel;
967 228696 : pathnode->parallel_workers = parallel_workers;
968 228696 : pathnode->pathkeys = NIL; /* seqscan has unordered result */
969 :
970 228696 : cost_seqscan(pathnode, root, rel, pathnode->param_info);
971 :
972 228696 : return pathnode;
973 : }
974 :
975 : /*
976 : * create_samplescan_path
977 : * Creates a path node for a sampled table scan.
978 : */
979 : Path *
980 180 : create_samplescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
981 : {
982 180 : Path *pathnode = makeNode(Path);
983 :
984 180 : pathnode->pathtype = T_SampleScan;
985 180 : pathnode->parent = rel;
986 180 : pathnode->pathtarget = rel->reltarget;
987 180 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
988 : required_outer);
989 180 : pathnode->parallel_aware = false;
990 180 : pathnode->parallel_safe = rel->consider_parallel;
991 180 : pathnode->parallel_workers = 0;
992 180 : pathnode->pathkeys = NIL; /* samplescan has unordered result */
993 :
994 180 : cost_samplescan(pathnode, root, rel, pathnode->param_info);
995 :
996 180 : return pathnode;
997 : }
998 :
999 : /*
1000 : * create_index_path
1001 : * Creates a path node for an index scan.
1002 : *
1003 : * 'index' is a usable index.
1004 : * 'indexclauses' is a list of IndexClause nodes representing clauses
1005 : * to be enforced as qual conditions in the scan.
1006 : * 'indexorderbys' is a list of bare expressions (no RestrictInfos)
1007 : * to be used as index ordering operators in the scan.
1008 : * 'indexorderbycols' is an integer list of index column numbers (zero based)
1009 : * the ordering operators can be used with.
1010 : * 'pathkeys' describes the ordering of the path.
1011 : * 'indexscandir' is ForwardScanDirection or BackwardScanDirection
1012 : * for an ordered index, or NoMovementScanDirection for
1013 : * an unordered index.
1014 : * 'indexonly' is true if an index-only scan is wanted.
1015 : * 'required_outer' is the set of outer relids for a parameterized path.
1016 : * 'loop_count' is the number of repetitions of the indexscan to factor into
1017 : * estimates of caching behavior.
1018 : * 'partial_path' is true if constructing a parallel index scan path.
1019 : *
1020 : * Returns the new path node.
1021 : */
1022 : IndexPath *
1023 366182 : create_index_path(PlannerInfo *root,
1024 : IndexOptInfo *index,
1025 : List *indexclauses,
1026 : List *indexorderbys,
1027 : List *indexorderbycols,
1028 : List *pathkeys,
1029 : ScanDirection indexscandir,
1030 : bool indexonly,
1031 : Relids required_outer,
1032 : double loop_count,
1033 : bool partial_path)
1034 : {
1035 366182 : IndexPath *pathnode = makeNode(IndexPath);
1036 366182 : RelOptInfo *rel = index->rel;
1037 :
1038 366182 : pathnode->path.pathtype = indexonly ? T_IndexOnlyScan : T_IndexScan;
1039 366182 : pathnode->path.parent = rel;
1040 366182 : pathnode->path.pathtarget = rel->reltarget;
1041 366182 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1042 : required_outer);
1043 366182 : pathnode->path.parallel_aware = false;
1044 366182 : pathnode->path.parallel_safe = rel->consider_parallel;
1045 366182 : pathnode->path.parallel_workers = 0;
1046 366182 : pathnode->path.pathkeys = pathkeys;
1047 :
1048 366182 : pathnode->indexinfo = index;
1049 366182 : pathnode->indexclauses = indexclauses;
1050 366182 : pathnode->indexorderbys = indexorderbys;
1051 366182 : pathnode->indexorderbycols = indexorderbycols;
1052 366182 : pathnode->indexscandir = indexscandir;
1053 :
1054 366182 : cost_index(pathnode, root, loop_count, partial_path);
1055 :
1056 366182 : return pathnode;
1057 : }
1058 :
1059 : /*
1060 : * create_bitmap_heap_path
1061 : * Creates a path node for a bitmap scan.
1062 : *
1063 : * 'bitmapqual' is a tree of IndexPath, BitmapAndPath, and BitmapOrPath nodes.
1064 : * 'required_outer' is the set of outer relids for a parameterized path.
1065 : * 'loop_count' is the number of repetitions of the indexscan to factor into
1066 : * estimates of caching behavior.
1067 : *
1068 : * loop_count should match the value used when creating the component
1069 : * IndexPaths.
1070 : */
1071 : BitmapHeapPath *
1072 173102 : create_bitmap_heap_path(PlannerInfo *root,
1073 : RelOptInfo *rel,
1074 : Path *bitmapqual,
1075 : Relids required_outer,
1076 : double loop_count,
1077 : int parallel_degree)
1078 : {
1079 173102 : BitmapHeapPath *pathnode = makeNode(BitmapHeapPath);
1080 :
1081 173102 : pathnode->path.pathtype = T_BitmapHeapScan;
1082 173102 : pathnode->path.parent = rel;
1083 173102 : pathnode->path.pathtarget = rel->reltarget;
1084 173102 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1085 : required_outer);
1086 173102 : pathnode->path.parallel_aware = parallel_degree > 0 ? true : false;
1087 173102 : pathnode->path.parallel_safe = rel->consider_parallel;
1088 173102 : pathnode->path.parallel_workers = parallel_degree;
1089 173102 : pathnode->path.pathkeys = NIL; /* always unordered */
1090 :
1091 173102 : pathnode->bitmapqual = bitmapqual;
1092 :
1093 173102 : cost_bitmap_heap_scan(&pathnode->path, root, rel,
1094 : pathnode->path.param_info,
1095 : bitmapqual, loop_count);
1096 :
1097 173102 : return pathnode;
1098 : }
1099 :
1100 : /*
1101 : * create_bitmap_and_path
1102 : * Creates a path node representing a BitmapAnd.
1103 : */
1104 : BitmapAndPath *
1105 44 : create_bitmap_and_path(PlannerInfo *root,
1106 : RelOptInfo *rel,
1107 : List *bitmapquals)
1108 : {
1109 44 : BitmapAndPath *pathnode = makeNode(BitmapAndPath);
1110 :
1111 44 : pathnode->path.pathtype = T_BitmapAnd;
1112 44 : pathnode->path.parent = rel;
1113 44 : pathnode->path.pathtarget = rel->reltarget;
1114 44 : pathnode->path.param_info = NULL; /* not used in bitmap trees */
1115 :
1116 : /*
1117 : * Currently, a BitmapHeapPath, BitmapAndPath, or BitmapOrPath will be
1118 : * parallel-safe if and only if rel->consider_parallel is set. So, we can
1119 : * set the flag for this path based only on the relation-level flag,
1120 : * without actually iterating over the list of children.
1121 : */
1122 44 : pathnode->path.parallel_aware = false;
1123 44 : pathnode->path.parallel_safe = rel->consider_parallel;
1124 44 : pathnode->path.parallel_workers = 0;
1125 :
1126 44 : pathnode->path.pathkeys = NIL; /* always unordered */
1127 :
1128 44 : pathnode->bitmapquals = bitmapquals;
1129 :
1130 : /* this sets bitmapselectivity as well as the regular cost fields: */
1131 44 : cost_bitmap_and_node(pathnode, root);
1132 :
1133 44 : return pathnode;
1134 : }
1135 :
1136 : /*
1137 : * create_bitmap_or_path
1138 : * Creates a path node representing a BitmapOr.
1139 : */
1140 : BitmapOrPath *
1141 318 : create_bitmap_or_path(PlannerInfo *root,
1142 : RelOptInfo *rel,
1143 : List *bitmapquals)
1144 : {
1145 318 : BitmapOrPath *pathnode = makeNode(BitmapOrPath);
1146 :
1147 318 : pathnode->path.pathtype = T_BitmapOr;
1148 318 : pathnode->path.parent = rel;
1149 318 : pathnode->path.pathtarget = rel->reltarget;
1150 318 : pathnode->path.param_info = NULL; /* not used in bitmap trees */
1151 :
1152 : /*
1153 : * Currently, a BitmapHeapPath, BitmapAndPath, or BitmapOrPath will be
1154 : * parallel-safe if and only if rel->consider_parallel is set. So, we can
1155 : * set the flag for this path based only on the relation-level flag,
1156 : * without actually iterating over the list of children.
1157 : */
1158 318 : pathnode->path.parallel_aware = false;
1159 318 : pathnode->path.parallel_safe = rel->consider_parallel;
1160 318 : pathnode->path.parallel_workers = 0;
1161 :
1162 318 : pathnode->path.pathkeys = NIL; /* always unordered */
1163 :
1164 318 : pathnode->bitmapquals = bitmapquals;
1165 :
1166 : /* this sets bitmapselectivity as well as the regular cost fields: */
1167 318 : cost_bitmap_or_node(pathnode, root);
1168 :
1169 318 : return pathnode;
1170 : }
1171 :
1172 : /*
1173 : * create_tidscan_path
1174 : * Creates a path corresponding to a scan by TID, returning the pathnode.
1175 : */
1176 : TidPath *
1177 594 : create_tidscan_path(PlannerInfo *root, RelOptInfo *rel, List *tidquals,
1178 : Relids required_outer)
1179 : {
1180 594 : TidPath *pathnode = makeNode(TidPath);
1181 :
1182 594 : pathnode->path.pathtype = T_TidScan;
1183 594 : pathnode->path.parent = rel;
1184 594 : pathnode->path.pathtarget = rel->reltarget;
1185 594 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1186 : required_outer);
1187 594 : pathnode->path.parallel_aware = false;
1188 594 : pathnode->path.parallel_safe = rel->consider_parallel;
1189 594 : pathnode->path.parallel_workers = 0;
1190 594 : pathnode->path.pathkeys = NIL; /* always unordered */
1191 :
1192 594 : pathnode->tidquals = tidquals;
1193 :
1194 594 : cost_tidscan(&pathnode->path, root, rel, tidquals,
1195 : pathnode->path.param_info);
1196 :
1197 594 : return pathnode;
1198 : }
1199 :
1200 : /*
1201 : * create_append_path
1202 : * Creates a path corresponding to an Append plan, returning the
1203 : * pathnode.
1204 : *
1205 : * Note that we must handle subpaths = NIL, representing a dummy access path.
1206 : * Also, there are callers that pass root = NULL.
1207 : */
1208 : AppendPath *
1209 27800 : create_append_path(PlannerInfo *root,
1210 : RelOptInfo *rel,
1211 : List *subpaths, List *partial_subpaths,
1212 : List *pathkeys, Relids required_outer,
1213 : int parallel_workers, bool parallel_aware,
1214 : List *partitioned_rels, double rows)
1215 : {
1216 27800 : AppendPath *pathnode = makeNode(AppendPath);
1217 : ListCell *l;
1218 :
1219 : Assert(!parallel_aware || parallel_workers > 0);
1220 :
1221 27800 : pathnode->path.pathtype = T_Append;
1222 27800 : pathnode->path.parent = rel;
1223 27800 : pathnode->path.pathtarget = rel->reltarget;
1224 :
1225 : /*
1226 : * When generating an Append path for a partitioned table, there may be
1227 : * parameters that are useful so we can eliminate certain partitions
1228 : * during execution. Here we'll go all the way and fully populate the
1229 : * parameter info data as we do for normal base relations. However, we
1230 : * need only bother doing this for RELOPT_BASEREL rels, as
1231 : * RELOPT_OTHER_MEMBER_REL's Append paths are merged into the base rel's
1232 : * Append subpaths. It would do no harm to do this, we just avoid it to
1233 : * save wasting effort.
1234 : */
1235 27800 : if (partitioned_rels != NIL && root && rel->reloptkind == RELOPT_BASEREL)
1236 11270 : pathnode->path.param_info = get_baserel_parampathinfo(root,
1237 : rel,
1238 : required_outer);
1239 : else
1240 16530 : pathnode->path.param_info = get_appendrel_parampathinfo(rel,
1241 : required_outer);
1242 :
1243 27800 : pathnode->path.parallel_aware = parallel_aware;
1244 27800 : pathnode->path.parallel_safe = rel->consider_parallel;
1245 27800 : pathnode->path.parallel_workers = parallel_workers;
1246 27800 : pathnode->path.pathkeys = pathkeys;
1247 27800 : pathnode->partitioned_rels = list_copy(partitioned_rels);
1248 :
1249 : /*
1250 : * For parallel append, non-partial paths are sorted by descending total
1251 : * costs. That way, the total time to finish all non-partial paths is
1252 : * minimized. Also, the partial paths are sorted by descending startup
1253 : * costs. There may be some paths that require to do startup work by a
1254 : * single worker. In such case, it's better for workers to choose the
1255 : * expensive ones first, whereas the leader should choose the cheapest
1256 : * startup plan.
1257 : */
1258 27800 : if (pathnode->path.parallel_aware)
1259 : {
1260 : /*
1261 : * We mustn't fiddle with the order of subpaths when the Append has
1262 : * pathkeys. The order they're listed in is critical to keeping the
1263 : * pathkeys valid.
1264 : */
1265 : Assert(pathkeys == NIL);
1266 :
1267 9552 : subpaths = list_qsort(subpaths, append_total_cost_compare);
1268 9552 : partial_subpaths = list_qsort(partial_subpaths,
1269 : append_startup_cost_compare);
1270 : }
1271 27800 : pathnode->first_partial_path = list_length(subpaths);
1272 27800 : pathnode->subpaths = list_concat(subpaths, partial_subpaths);
1273 :
1274 : /*
1275 : * Apply query-wide LIMIT if known and path is for sole base relation.
1276 : * (Handling this at this low level is a bit klugy.)
1277 : */
1278 27800 : if (root != NULL && bms_equal(rel->relids, root->all_baserels))
1279 13534 : pathnode->limit_tuples = root->limit_tuples;
1280 : else
1281 14266 : pathnode->limit_tuples = -1.0;
1282 :
1283 102058 : foreach(l, pathnode->subpaths)
1284 : {
1285 74258 : Path *subpath = (Path *) lfirst(l);
1286 :
1287 134614 : pathnode->path.parallel_safe = pathnode->path.parallel_safe &&
1288 60356 : subpath->parallel_safe;
1289 :
1290 : /* All child paths must have same parameterization */
1291 : Assert(bms_equal(PATH_REQ_OUTER(subpath), required_outer));
1292 : }
1293 :
1294 : Assert(!parallel_aware || pathnode->path.parallel_safe);
1295 :
1296 : /*
1297 : * If there's exactly one child path, the Append is a no-op and will be
1298 : * discarded later (in setrefs.c); therefore, we can inherit the child's
1299 : * size and cost, as well as its pathkeys if any (overriding whatever the
1300 : * caller might've said). Otherwise, we must do the normal costsize
1301 : * calculation.
1302 : */
1303 27800 : if (list_length(pathnode->subpaths) == 1)
1304 : {
1305 4686 : Path *child = (Path *) linitial(pathnode->subpaths);
1306 :
1307 4686 : pathnode->path.rows = child->rows;
1308 4686 : pathnode->path.startup_cost = child->startup_cost;
1309 4686 : pathnode->path.total_cost = child->total_cost;
1310 4686 : pathnode->path.pathkeys = child->pathkeys;
1311 : }
1312 : else
1313 23114 : cost_append(pathnode);
1314 :
1315 : /* If the caller provided a row estimate, override the computed value. */
1316 27800 : if (rows >= 0)
1317 244 : pathnode->path.rows = rows;
1318 :
1319 27800 : return pathnode;
1320 : }
1321 :
1322 : /*
1323 : * append_total_cost_compare
1324 : * qsort comparator for sorting append child paths by total_cost descending
1325 : *
1326 : * For equal total costs, we fall back to comparing startup costs; if those
1327 : * are equal too, break ties using bms_compare on the paths' relids.
1328 : * (This is to avoid getting unpredictable results from qsort.)
1329 : */
1330 : static int
1331 2036 : append_total_cost_compare(const void *a, const void *b)
1332 : {
1333 2036 : Path *path1 = (Path *) lfirst(*(ListCell **) a);
1334 2036 : Path *path2 = (Path *) lfirst(*(ListCell **) b);
1335 : int cmp;
1336 :
1337 2036 : cmp = compare_path_costs(path1, path2, TOTAL_COST);
1338 2036 : if (cmp != 0)
1339 1636 : return -cmp;
1340 400 : return bms_compare(path1->parent->relids, path2->parent->relids);
1341 : }
1342 :
1343 : /*
1344 : * append_startup_cost_compare
1345 : * qsort comparator for sorting append child paths by startup_cost descending
1346 : *
1347 : * For equal startup costs, we fall back to comparing total costs; if those
1348 : * are equal too, break ties using bms_compare on the paths' relids.
1349 : * (This is to avoid getting unpredictable results from qsort.)
1350 : */
1351 : static int
1352 17646 : append_startup_cost_compare(const void *a, const void *b)
1353 : {
1354 17646 : Path *path1 = (Path *) lfirst(*(ListCell **) a);
1355 17646 : Path *path2 = (Path *) lfirst(*(ListCell **) b);
1356 : int cmp;
1357 :
1358 17646 : cmp = compare_path_costs(path1, path2, STARTUP_COST);
1359 17646 : if (cmp != 0)
1360 4026 : return -cmp;
1361 13620 : return bms_compare(path1->parent->relids, path2->parent->relids);
1362 : }
1363 :
1364 : /*
1365 : * create_merge_append_path
1366 : * Creates a path corresponding to a MergeAppend plan, returning the
1367 : * pathnode.
1368 : */
1369 : MergeAppendPath *
1370 1344 : create_merge_append_path(PlannerInfo *root,
1371 : RelOptInfo *rel,
1372 : List *subpaths,
1373 : List *pathkeys,
1374 : Relids required_outer,
1375 : List *partitioned_rels)
1376 : {
1377 1344 : MergeAppendPath *pathnode = makeNode(MergeAppendPath);
1378 : Cost input_startup_cost;
1379 : Cost input_total_cost;
1380 : ListCell *l;
1381 :
1382 1344 : pathnode->path.pathtype = T_MergeAppend;
1383 1344 : pathnode->path.parent = rel;
1384 1344 : pathnode->path.pathtarget = rel->reltarget;
1385 1344 : pathnode->path.param_info = get_appendrel_parampathinfo(rel,
1386 : required_outer);
1387 1344 : pathnode->path.parallel_aware = false;
1388 1344 : pathnode->path.parallel_safe = rel->consider_parallel;
1389 1344 : pathnode->path.parallel_workers = 0;
1390 1344 : pathnode->path.pathkeys = pathkeys;
1391 1344 : pathnode->partitioned_rels = list_copy(partitioned_rels);
1392 1344 : pathnode->subpaths = subpaths;
1393 :
1394 : /*
1395 : * Apply query-wide LIMIT if known and path is for sole base relation.
1396 : * (Handling this at this low level is a bit klugy.)
1397 : */
1398 1344 : if (bms_equal(rel->relids, root->all_baserels))
1399 488 : pathnode->limit_tuples = root->limit_tuples;
1400 : else
1401 856 : pathnode->limit_tuples = -1.0;
1402 :
1403 : /*
1404 : * Add up the sizes and costs of the input paths.
1405 : */
1406 1344 : pathnode->path.rows = 0;
1407 1344 : input_startup_cost = 0;
1408 1344 : input_total_cost = 0;
1409 5158 : foreach(l, subpaths)
1410 : {
1411 3814 : Path *subpath = (Path *) lfirst(l);
1412 :
1413 3814 : pathnode->path.rows += subpath->rows;
1414 6378 : pathnode->path.parallel_safe = pathnode->path.parallel_safe &&
1415 2564 : subpath->parallel_safe;
1416 :
1417 3814 : if (pathkeys_contained_in(pathkeys, subpath->pathkeys))
1418 : {
1419 : /* Subpath is adequately ordered, we won't need to sort it */
1420 3674 : input_startup_cost += subpath->startup_cost;
1421 3674 : input_total_cost += subpath->total_cost;
1422 : }
1423 : else
1424 : {
1425 : /* We'll need to insert a Sort node, so include cost for that */
1426 : Path sort_path; /* dummy for result of cost_sort */
1427 :
1428 420 : cost_sort(&sort_path,
1429 : root,
1430 : pathkeys,
1431 : subpath->total_cost,
1432 140 : subpath->parent->tuples,
1433 140 : subpath->pathtarget->width,
1434 : 0.0,
1435 : work_mem,
1436 : pathnode->limit_tuples);
1437 140 : input_startup_cost += sort_path.startup_cost;
1438 140 : input_total_cost += sort_path.total_cost;
1439 : }
1440 :
1441 : /* All child paths must have same parameterization */
1442 : Assert(bms_equal(PATH_REQ_OUTER(subpath), required_outer));
1443 : }
1444 :
1445 : /*
1446 : * Now we can compute total costs of the MergeAppend. If there's exactly
1447 : * one child path, the MergeAppend is a no-op and will be discarded later
1448 : * (in setrefs.c); otherwise we do the normal cost calculation.
1449 : */
1450 1344 : if (list_length(subpaths) == 1)
1451 : {
1452 38 : pathnode->path.startup_cost = input_startup_cost;
1453 38 : pathnode->path.total_cost = input_total_cost;
1454 : }
1455 : else
1456 1306 : cost_merge_append(&pathnode->path, root,
1457 : pathkeys, list_length(subpaths),
1458 : input_startup_cost, input_total_cost,
1459 : pathnode->path.rows);
1460 :
1461 1344 : return pathnode;
1462 : }
1463 :
1464 : /*
1465 : * create_group_result_path
1466 : * Creates a path representing a Result-and-nothing-else plan.
1467 : *
1468 : * This is only used for degenerate grouping cases, in which we know we
1469 : * need to produce one result row, possibly filtered by a HAVING qual.
1470 : */
1471 : GroupResultPath *
1472 110030 : create_group_result_path(PlannerInfo *root, RelOptInfo *rel,
1473 : PathTarget *target, List *havingqual)
1474 : {
1475 110030 : GroupResultPath *pathnode = makeNode(GroupResultPath);
1476 :
1477 110030 : pathnode->path.pathtype = T_Result;
1478 110030 : pathnode->path.parent = rel;
1479 110030 : pathnode->path.pathtarget = target;
1480 110030 : pathnode->path.param_info = NULL; /* there are no other rels... */
1481 110030 : pathnode->path.parallel_aware = false;
1482 110030 : pathnode->path.parallel_safe = rel->consider_parallel;
1483 110030 : pathnode->path.parallel_workers = 0;
1484 110030 : pathnode->path.pathkeys = NIL;
1485 110030 : pathnode->quals = havingqual;
1486 :
1487 : /*
1488 : * We can't quite use cost_resultscan() because the quals we want to
1489 : * account for are not baserestrict quals of the rel. Might as well just
1490 : * hack it here.
1491 : */
1492 110030 : pathnode->path.rows = 1;
1493 110030 : pathnode->path.startup_cost = target->cost.startup;
1494 220060 : pathnode->path.total_cost = target->cost.startup +
1495 110030 : cpu_tuple_cost + target->cost.per_tuple;
1496 :
1497 : /*
1498 : * Add cost of qual, if any --- but we ignore its selectivity, since our
1499 : * rowcount estimate should be 1 no matter what the qual is.
1500 : */
1501 110030 : if (havingqual)
1502 : {
1503 : QualCost qual_cost;
1504 :
1505 260 : cost_qual_eval(&qual_cost, havingqual, root);
1506 : /* havingqual is evaluated once at startup */
1507 260 : pathnode->path.startup_cost += qual_cost.startup + qual_cost.per_tuple;
1508 260 : pathnode->path.total_cost += qual_cost.startup + qual_cost.per_tuple;
1509 : }
1510 :
1511 110030 : return pathnode;
1512 : }
1513 :
1514 : /*
1515 : * create_material_path
1516 : * Creates a path corresponding to a Material plan, returning the
1517 : * pathnode.
1518 : */
1519 : MaterialPath *
1520 214614 : create_material_path(RelOptInfo *rel, Path *subpath)
1521 : {
1522 214614 : MaterialPath *pathnode = makeNode(MaterialPath);
1523 :
1524 : Assert(subpath->parent == rel);
1525 :
1526 214614 : pathnode->path.pathtype = T_Material;
1527 214614 : pathnode->path.parent = rel;
1528 214614 : pathnode->path.pathtarget = rel->reltarget;
1529 214614 : pathnode->path.param_info = subpath->param_info;
1530 214614 : pathnode->path.parallel_aware = false;
1531 404482 : pathnode->path.parallel_safe = rel->consider_parallel &&
1532 189868 : subpath->parallel_safe;
1533 214614 : pathnode->path.parallel_workers = subpath->parallel_workers;
1534 214614 : pathnode->path.pathkeys = subpath->pathkeys;
1535 :
1536 214614 : pathnode->subpath = subpath;
1537 :
1538 214614 : cost_material(&pathnode->path,
1539 : subpath->startup_cost,
1540 : subpath->total_cost,
1541 : subpath->rows,
1542 214614 : subpath->pathtarget->width);
1543 :
1544 214614 : return pathnode;
1545 : }
1546 :
1547 : /*
1548 : * create_unique_path
1549 : * Creates a path representing elimination of distinct rows from the
1550 : * input data. Distinct-ness is defined according to the needs of the
1551 : * semijoin represented by sjinfo. If it is not possible to identify
1552 : * how to make the data unique, NULL is returned.
1553 : *
1554 : * If used at all, this is likely to be called repeatedly on the same rel;
1555 : * and the input subpath should always be the same (the cheapest_total path
1556 : * for the rel). So we cache the result.
1557 : */
1558 : UniquePath *
1559 10806 : create_unique_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
1560 : SpecialJoinInfo *sjinfo)
1561 : {
1562 : UniquePath *pathnode;
1563 : Path sort_path; /* dummy for result of cost_sort */
1564 : Path agg_path; /* dummy for result of cost_agg */
1565 : MemoryContext oldcontext;
1566 : int numCols;
1567 :
1568 : /* Caller made a mistake if subpath isn't cheapest_total ... */
1569 : Assert(subpath == rel->cheapest_total_path);
1570 : Assert(subpath->parent == rel);
1571 : /* ... or if SpecialJoinInfo is the wrong one */
1572 : Assert(sjinfo->jointype == JOIN_SEMI);
1573 : Assert(bms_equal(rel->relids, sjinfo->syn_righthand));
1574 :
1575 : /* If result already cached, return it */
1576 10806 : if (rel->cheapest_unique_path)
1577 9036 : return (UniquePath *) rel->cheapest_unique_path;
1578 :
1579 : /* If it's not possible to unique-ify, return NULL */
1580 1770 : if (!(sjinfo->semi_can_btree || sjinfo->semi_can_hash))
1581 62 : return NULL;
1582 :
1583 : /*
1584 : * When called during GEQO join planning, we are in a short-lived memory
1585 : * context. We must make sure that the path and any subsidiary data
1586 : * structures created for a baserel survive the GEQO cycle, else the
1587 : * baserel is trashed for future GEQO cycles. On the other hand, when we
1588 : * are creating those for a joinrel during GEQO, we don't want them to
1589 : * clutter the main planning context. Upshot is that the best solution is
1590 : * to explicitly allocate memory in the same context the given RelOptInfo
1591 : * is in.
1592 : */
1593 1708 : oldcontext = MemoryContextSwitchTo(GetMemoryChunkContext(rel));
1594 :
1595 1708 : pathnode = makeNode(UniquePath);
1596 :
1597 1708 : pathnode->path.pathtype = T_Unique;
1598 1708 : pathnode->path.parent = rel;
1599 1708 : pathnode->path.pathtarget = rel->reltarget;
1600 1708 : pathnode->path.param_info = subpath->param_info;
1601 1708 : pathnode->path.parallel_aware = false;
1602 3256 : pathnode->path.parallel_safe = rel->consider_parallel &&
1603 1548 : subpath->parallel_safe;
1604 1708 : pathnode->path.parallel_workers = subpath->parallel_workers;
1605 :
1606 : /*
1607 : * Assume the output is unsorted, since we don't necessarily have pathkeys
1608 : * to represent it. (This might get overridden below.)
1609 : */
1610 1708 : pathnode->path.pathkeys = NIL;
1611 :
1612 1708 : pathnode->subpath = subpath;
1613 1708 : pathnode->in_operators = sjinfo->semi_operators;
1614 1708 : pathnode->uniq_exprs = sjinfo->semi_rhs_exprs;
1615 :
1616 : /*
1617 : * If the input is a relation and it has a unique index that proves the
1618 : * semi_rhs_exprs are unique, then we don't need to do anything. Note
1619 : * that relation_has_unique_index_for automatically considers restriction
1620 : * clauses for the rel, as well.
1621 : */
1622 1980 : if (rel->rtekind == RTE_RELATION && sjinfo->semi_can_btree &&
1623 272 : relation_has_unique_index_for(root, rel, NIL,
1624 : sjinfo->semi_rhs_exprs,
1625 : sjinfo->semi_operators))
1626 : {
1627 0 : pathnode->umethod = UNIQUE_PATH_NOOP;
1628 0 : pathnode->path.rows = rel->rows;
1629 0 : pathnode->path.startup_cost = subpath->startup_cost;
1630 0 : pathnode->path.total_cost = subpath->total_cost;
1631 0 : pathnode->path.pathkeys = subpath->pathkeys;
1632 :
1633 0 : rel->cheapest_unique_path = (Path *) pathnode;
1634 :
1635 0 : MemoryContextSwitchTo(oldcontext);
1636 :
1637 0 : return pathnode;
1638 : }
1639 :
1640 : /*
1641 : * If the input is a subquery whose output must be unique already, then we
1642 : * don't need to do anything. The test for uniqueness has to consider
1643 : * exactly which columns we are extracting; for example "SELECT DISTINCT
1644 : * x,y" doesn't guarantee that x alone is distinct. So we cannot check for
1645 : * this optimization unless semi_rhs_exprs consists only of simple Vars
1646 : * referencing subquery outputs. (Possibly we could do something with
1647 : * expressions in the subquery outputs, too, but for now keep it simple.)
1648 : */
1649 1708 : if (rel->rtekind == RTE_SUBQUERY)
1650 : {
1651 256 : RangeTblEntry *rte = planner_rt_fetch(rel->relid, root);
1652 :
1653 256 : if (query_supports_distinctness(rte->subquery))
1654 : {
1655 : List *sub_tlist_colnos;
1656 :
1657 232 : sub_tlist_colnos = translate_sub_tlist(sjinfo->semi_rhs_exprs,
1658 232 : rel->relid);
1659 :
1660 272 : if (sub_tlist_colnos &&
1661 40 : query_is_distinct_for(rte->subquery,
1662 : sub_tlist_colnos,
1663 : sjinfo->semi_operators))
1664 : {
1665 0 : pathnode->umethod = UNIQUE_PATH_NOOP;
1666 0 : pathnode->path.rows = rel->rows;
1667 0 : pathnode->path.startup_cost = subpath->startup_cost;
1668 0 : pathnode->path.total_cost = subpath->total_cost;
1669 0 : pathnode->path.pathkeys = subpath->pathkeys;
1670 :
1671 0 : rel->cheapest_unique_path = (Path *) pathnode;
1672 :
1673 0 : MemoryContextSwitchTo(oldcontext);
1674 :
1675 0 : return pathnode;
1676 : }
1677 : }
1678 : }
1679 :
1680 : /* Estimate number of output rows */
1681 1708 : pathnode->path.rows = estimate_num_groups(root,
1682 : sjinfo->semi_rhs_exprs,
1683 : rel->rows,
1684 : NULL);
1685 1708 : numCols = list_length(sjinfo->semi_rhs_exprs);
1686 :
1687 1708 : if (sjinfo->semi_can_btree)
1688 : {
1689 : /*
1690 : * Estimate cost for sort+unique implementation
1691 : */
1692 3416 : cost_sort(&sort_path, root, NIL,
1693 : subpath->total_cost,
1694 : rel->rows,
1695 1708 : subpath->pathtarget->width,
1696 : 0.0,
1697 : work_mem,
1698 : -1.0);
1699 :
1700 : /*
1701 : * Charge one cpu_operator_cost per comparison per input tuple. We
1702 : * assume all columns get compared at most of the tuples. (XXX
1703 : * probably this is an overestimate.) This should agree with
1704 : * create_upper_unique_path.
1705 : */
1706 1708 : sort_path.total_cost += cpu_operator_cost * rel->rows * numCols;
1707 : }
1708 :
1709 1708 : if (sjinfo->semi_can_hash)
1710 : {
1711 : /*
1712 : * Estimate the overhead per hashtable entry at 64 bytes (same as in
1713 : * planner.c).
1714 : */
1715 1708 : int hashentrysize = subpath->pathtarget->width + 64;
1716 :
1717 1708 : if (hashentrysize * pathnode->path.rows > work_mem * 1024L)
1718 : {
1719 : /*
1720 : * We should not try to hash. Hack the SpecialJoinInfo to
1721 : * remember this, in case we come through here again.
1722 : */
1723 0 : sjinfo->semi_can_hash = false;
1724 : }
1725 : else
1726 1708 : cost_agg(&agg_path, root,
1727 : AGG_HASHED, NULL,
1728 : numCols, pathnode->path.rows,
1729 : NIL,
1730 : subpath->startup_cost,
1731 : subpath->total_cost,
1732 : rel->rows);
1733 : }
1734 :
1735 1708 : if (sjinfo->semi_can_btree && sjinfo->semi_can_hash)
1736 : {
1737 3416 : if (agg_path.total_cost < sort_path.total_cost)
1738 1658 : pathnode->umethod = UNIQUE_PATH_HASH;
1739 : else
1740 50 : pathnode->umethod = UNIQUE_PATH_SORT;
1741 : }
1742 0 : else if (sjinfo->semi_can_btree)
1743 0 : pathnode->umethod = UNIQUE_PATH_SORT;
1744 0 : else if (sjinfo->semi_can_hash)
1745 0 : pathnode->umethod = UNIQUE_PATH_HASH;
1746 : else
1747 : {
1748 : /* we can get here only if we abandoned hashing above */
1749 0 : MemoryContextSwitchTo(oldcontext);
1750 0 : return NULL;
1751 : }
1752 :
1753 1708 : if (pathnode->umethod == UNIQUE_PATH_HASH)
1754 : {
1755 1658 : pathnode->path.startup_cost = agg_path.startup_cost;
1756 1658 : pathnode->path.total_cost = agg_path.total_cost;
1757 : }
1758 : else
1759 : {
1760 50 : pathnode->path.startup_cost = sort_path.startup_cost;
1761 50 : pathnode->path.total_cost = sort_path.total_cost;
1762 : }
1763 :
1764 1708 : rel->cheapest_unique_path = (Path *) pathnode;
1765 :
1766 1708 : MemoryContextSwitchTo(oldcontext);
1767 :
1768 1708 : return pathnode;
1769 : }
1770 :
1771 : /*
1772 : * create_gather_merge_path
1773 : *
1774 : * Creates a path corresponding to a gather merge scan, returning
1775 : * the pathnode.
1776 : */
1777 : GatherMergePath *
1778 2844 : create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
1779 : PathTarget *target, List *pathkeys,
1780 : Relids required_outer, double *rows)
1781 : {
1782 2844 : GatherMergePath *pathnode = makeNode(GatherMergePath);
1783 2844 : Cost input_startup_cost = 0;
1784 2844 : Cost input_total_cost = 0;
1785 :
1786 : Assert(subpath->parallel_safe);
1787 : Assert(pathkeys);
1788 :
1789 2844 : pathnode->path.pathtype = T_GatherMerge;
1790 2844 : pathnode->path.parent = rel;
1791 2844 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1792 : required_outer);
1793 2844 : pathnode->path.parallel_aware = false;
1794 :
1795 2844 : pathnode->subpath = subpath;
1796 2844 : pathnode->num_workers = subpath->parallel_workers;
1797 2844 : pathnode->path.pathkeys = pathkeys;
1798 2844 : pathnode->path.pathtarget = target ? target : rel->reltarget;
1799 2844 : pathnode->path.rows += subpath->rows;
1800 :
1801 2844 : if (pathkeys_contained_in(pathkeys, subpath->pathkeys))
1802 : {
1803 : /* Subpath is adequately ordered, we won't need to sort it */
1804 2844 : input_startup_cost += subpath->startup_cost;
1805 2844 : input_total_cost += subpath->total_cost;
1806 : }
1807 : else
1808 : {
1809 : /* We'll need to insert a Sort node, so include cost for that */
1810 : Path sort_path; /* dummy for result of cost_sort */
1811 :
1812 0 : cost_sort(&sort_path,
1813 : root,
1814 : pathkeys,
1815 : subpath->total_cost,
1816 : subpath->rows,
1817 0 : subpath->pathtarget->width,
1818 : 0.0,
1819 : work_mem,
1820 : -1);
1821 0 : input_startup_cost += sort_path.startup_cost;
1822 0 : input_total_cost += sort_path.total_cost;
1823 : }
1824 :
1825 2844 : cost_gather_merge(pathnode, root, rel, pathnode->path.param_info,
1826 : input_startup_cost, input_total_cost, rows);
1827 :
1828 2844 : return pathnode;
1829 : }
1830 :
1831 : /*
1832 : * translate_sub_tlist - get subquery column numbers represented by tlist
1833 : *
1834 : * The given targetlist usually contains only Vars referencing the given relid.
1835 : * Extract their varattnos (ie, the column numbers of the subquery) and return
1836 : * as an integer List.
1837 : *
1838 : * If any of the tlist items is not a simple Var, we cannot determine whether
1839 : * the subquery's uniqueness condition (if any) matches ours, so punt and
1840 : * return NIL.
1841 : */
1842 : static List *
1843 232 : translate_sub_tlist(List *tlist, int relid)
1844 : {
1845 232 : List *result = NIL;
1846 : ListCell *l;
1847 :
1848 272 : foreach(l, tlist)
1849 : {
1850 232 : Var *var = (Var *) lfirst(l);
1851 :
1852 272 : if (!var || !IsA(var, Var) ||
1853 40 : var->varno != relid)
1854 192 : return NIL; /* punt */
1855 :
1856 40 : result = lappend_int(result, var->varattno);
1857 : }
1858 40 : return result;
1859 : }
1860 :
1861 : /*
1862 : * create_gather_path
1863 : * Creates a path corresponding to a gather scan, returning the
1864 : * pathnode.
1865 : *
1866 : * 'rows' may optionally be set to override row estimates from other sources.
1867 : */
1868 : GatherPath *
1869 7720 : create_gather_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
1870 : PathTarget *target, Relids required_outer, double *rows)
1871 : {
1872 7720 : GatherPath *pathnode = makeNode(GatherPath);
1873 :
1874 : Assert(subpath->parallel_safe);
1875 :
1876 7720 : pathnode->path.pathtype = T_Gather;
1877 7720 : pathnode->path.parent = rel;
1878 7720 : pathnode->path.pathtarget = target;
1879 7720 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1880 : required_outer);
1881 7720 : pathnode->path.parallel_aware = false;
1882 7720 : pathnode->path.parallel_safe = false;
1883 7720 : pathnode->path.parallel_workers = 0;
1884 7720 : pathnode->path.pathkeys = NIL; /* Gather has unordered result */
1885 :
1886 7720 : pathnode->subpath = subpath;
1887 7720 : pathnode->num_workers = subpath->parallel_workers;
1888 7720 : pathnode->single_copy = false;
1889 :
1890 7720 : if (pathnode->num_workers == 0)
1891 : {
1892 0 : pathnode->path.pathkeys = subpath->pathkeys;
1893 0 : pathnode->num_workers = 1;
1894 0 : pathnode->single_copy = true;
1895 : }
1896 :
1897 7720 : cost_gather(pathnode, root, rel, pathnode->path.param_info, rows);
1898 :
1899 7720 : return pathnode;
1900 : }
1901 :
1902 : /*
1903 : * create_subqueryscan_path
1904 : * Creates a path corresponding to a scan of a subquery,
1905 : * returning the pathnode.
1906 : */
1907 : SubqueryScanPath *
1908 7924 : create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
1909 : List *pathkeys, Relids required_outer)
1910 : {
1911 7924 : SubqueryScanPath *pathnode = makeNode(SubqueryScanPath);
1912 :
1913 7924 : pathnode->path.pathtype = T_SubqueryScan;
1914 7924 : pathnode->path.parent = rel;
1915 7924 : pathnode->path.pathtarget = rel->reltarget;
1916 7924 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
1917 : required_outer);
1918 7924 : pathnode->path.parallel_aware = false;
1919 12050 : pathnode->path.parallel_safe = rel->consider_parallel &&
1920 4126 : subpath->parallel_safe;
1921 7924 : pathnode->path.parallel_workers = subpath->parallel_workers;
1922 7924 : pathnode->path.pathkeys = pathkeys;
1923 7924 : pathnode->subpath = subpath;
1924 :
1925 7924 : cost_subqueryscan(pathnode, root, rel, pathnode->path.param_info);
1926 :
1927 7924 : return pathnode;
1928 : }
1929 :
1930 : /*
1931 : * create_functionscan_path
1932 : * Creates a path corresponding to a sequential scan of a function,
1933 : * returning the pathnode.
1934 : */
1935 : Path *
1936 28734 : create_functionscan_path(PlannerInfo *root, RelOptInfo *rel,
1937 : List *pathkeys, Relids required_outer)
1938 : {
1939 28734 : Path *pathnode = makeNode(Path);
1940 :
1941 28734 : pathnode->pathtype = T_FunctionScan;
1942 28734 : pathnode->parent = rel;
1943 28734 : pathnode->pathtarget = rel->reltarget;
1944 28734 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
1945 : required_outer);
1946 28734 : pathnode->parallel_aware = false;
1947 28734 : pathnode->parallel_safe = rel->consider_parallel;
1948 28734 : pathnode->parallel_workers = 0;
1949 28734 : pathnode->pathkeys = pathkeys;
1950 :
1951 28734 : cost_functionscan(pathnode, root, rel, pathnode->param_info);
1952 :
1953 28734 : return pathnode;
1954 : }
1955 :
1956 : /*
1957 : * create_tablefuncscan_path
1958 : * Creates a path corresponding to a sequential scan of a table function,
1959 : * returning the pathnode.
1960 : */
1961 : Path *
1962 140 : create_tablefuncscan_path(PlannerInfo *root, RelOptInfo *rel,
1963 : Relids required_outer)
1964 : {
1965 140 : Path *pathnode = makeNode(Path);
1966 :
1967 140 : pathnode->pathtype = T_TableFuncScan;
1968 140 : pathnode->parent = rel;
1969 140 : pathnode->pathtarget = rel->reltarget;
1970 140 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
1971 : required_outer);
1972 140 : pathnode->parallel_aware = false;
1973 140 : pathnode->parallel_safe = rel->consider_parallel;
1974 140 : pathnode->parallel_workers = 0;
1975 140 : pathnode->pathkeys = NIL; /* result is always unordered */
1976 :
1977 140 : cost_tablefuncscan(pathnode, root, rel, pathnode->param_info);
1978 :
1979 140 : return pathnode;
1980 : }
1981 :
1982 : /*
1983 : * create_valuesscan_path
1984 : * Creates a path corresponding to a scan of a VALUES list,
1985 : * returning the pathnode.
1986 : */
1987 : Path *
1988 3774 : create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel,
1989 : Relids required_outer)
1990 : {
1991 3774 : Path *pathnode = makeNode(Path);
1992 :
1993 3774 : pathnode->pathtype = T_ValuesScan;
1994 3774 : pathnode->parent = rel;
1995 3774 : pathnode->pathtarget = rel->reltarget;
1996 3774 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
1997 : required_outer);
1998 3774 : pathnode->parallel_aware = false;
1999 3774 : pathnode->parallel_safe = rel->consider_parallel;
2000 3774 : pathnode->parallel_workers = 0;
2001 3774 : pathnode->pathkeys = NIL; /* result is always unordered */
2002 :
2003 3774 : cost_valuesscan(pathnode, root, rel, pathnode->param_info);
2004 :
2005 3774 : return pathnode;
2006 : }
2007 :
2008 : /*
2009 : * create_ctescan_path
2010 : * Creates a path corresponding to a scan of a non-self-reference CTE,
2011 : * returning the pathnode.
2012 : */
2013 : Path *
2014 894 : create_ctescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
2015 : {
2016 894 : Path *pathnode = makeNode(Path);
2017 :
2018 894 : pathnode->pathtype = T_CteScan;
2019 894 : pathnode->parent = rel;
2020 894 : pathnode->pathtarget = rel->reltarget;
2021 894 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
2022 : required_outer);
2023 894 : pathnode->parallel_aware = false;
2024 894 : pathnode->parallel_safe = rel->consider_parallel;
2025 894 : pathnode->parallel_workers = 0;
2026 894 : pathnode->pathkeys = NIL; /* XXX for now, result is always unordered */
2027 :
2028 894 : cost_ctescan(pathnode, root, rel, pathnode->param_info);
2029 :
2030 894 : return pathnode;
2031 : }
2032 :
2033 : /*
2034 : * create_namedtuplestorescan_path
2035 : * Creates a path corresponding to a scan of a named tuplestore, returning
2036 : * the pathnode.
2037 : */
2038 : Path *
2039 258 : create_namedtuplestorescan_path(PlannerInfo *root, RelOptInfo *rel,
2040 : Relids required_outer)
2041 : {
2042 258 : Path *pathnode = makeNode(Path);
2043 :
2044 258 : pathnode->pathtype = T_NamedTuplestoreScan;
2045 258 : pathnode->parent = rel;
2046 258 : pathnode->pathtarget = rel->reltarget;
2047 258 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
2048 : required_outer);
2049 258 : pathnode->parallel_aware = false;
2050 258 : pathnode->parallel_safe = rel->consider_parallel;
2051 258 : pathnode->parallel_workers = 0;
2052 258 : pathnode->pathkeys = NIL; /* result is always unordered */
2053 :
2054 258 : cost_namedtuplestorescan(pathnode, root, rel, pathnode->param_info);
2055 :
2056 258 : return pathnode;
2057 : }
2058 :
2059 : /*
2060 : * create_resultscan_path
2061 : * Creates a path corresponding to a scan of an RTE_RESULT relation,
2062 : * returning the pathnode.
2063 : */
2064 : Path *
2065 598 : create_resultscan_path(PlannerInfo *root, RelOptInfo *rel,
2066 : Relids required_outer)
2067 : {
2068 598 : Path *pathnode = makeNode(Path);
2069 :
2070 598 : pathnode->pathtype = T_Result;
2071 598 : pathnode->parent = rel;
2072 598 : pathnode->pathtarget = rel->reltarget;
2073 598 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
2074 : required_outer);
2075 598 : pathnode->parallel_aware = false;
2076 598 : pathnode->parallel_safe = rel->consider_parallel;
2077 598 : pathnode->parallel_workers = 0;
2078 598 : pathnode->pathkeys = NIL; /* result is always unordered */
2079 :
2080 598 : cost_resultscan(pathnode, root, rel, pathnode->param_info);
2081 :
2082 598 : return pathnode;
2083 : }
2084 :
2085 : /*
2086 : * create_worktablescan_path
2087 : * Creates a path corresponding to a scan of a self-reference CTE,
2088 : * returning the pathnode.
2089 : */
2090 : Path *
2091 326 : create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel,
2092 : Relids required_outer)
2093 : {
2094 326 : Path *pathnode = makeNode(Path);
2095 :
2096 326 : pathnode->pathtype = T_WorkTableScan;
2097 326 : pathnode->parent = rel;
2098 326 : pathnode->pathtarget = rel->reltarget;
2099 326 : pathnode->param_info = get_baserel_parampathinfo(root, rel,
2100 : required_outer);
2101 326 : pathnode->parallel_aware = false;
2102 326 : pathnode->parallel_safe = rel->consider_parallel;
2103 326 : pathnode->parallel_workers = 0;
2104 326 : pathnode->pathkeys = NIL; /* result is always unordered */
2105 :
2106 : /* Cost is the same as for a regular CTE scan */
2107 326 : cost_ctescan(pathnode, root, rel, pathnode->param_info);
2108 :
2109 326 : return pathnode;
2110 : }
2111 :
2112 : /*
2113 : * create_foreignscan_path
2114 : * Creates a path corresponding to a scan of a foreign base table,
2115 : * returning the pathnode.
2116 : *
2117 : * This function is never called from core Postgres; rather, it's expected
2118 : * to be called by the GetForeignPaths function of a foreign data wrapper.
2119 : * We make the FDW supply all fields of the path, since we do not have any way
2120 : * to calculate them in core. However, there is a usually-sane default for
2121 : * the pathtarget (rel->reltarget), so we let a NULL for "target" select that.
2122 : */
2123 : ForeignPath *
2124 2718 : create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel,
2125 : PathTarget *target,
2126 : double rows, Cost startup_cost, Cost total_cost,
2127 : List *pathkeys,
2128 : Relids required_outer,
2129 : Path *fdw_outerpath,
2130 : List *fdw_private)
2131 : {
2132 2718 : ForeignPath *pathnode = makeNode(ForeignPath);
2133 :
2134 : /* Historically some FDWs were confused about when to use this */
2135 : Assert(IS_SIMPLE_REL(rel));
2136 :
2137 2718 : pathnode->path.pathtype = T_ForeignScan;
2138 2718 : pathnode->path.parent = rel;
2139 2718 : pathnode->path.pathtarget = target ? target : rel->reltarget;
2140 2718 : pathnode->path.param_info = get_baserel_parampathinfo(root, rel,
2141 : required_outer);
2142 2718 : pathnode->path.parallel_aware = false;
2143 2718 : pathnode->path.parallel_safe = rel->consider_parallel;
2144 2718 : pathnode->path.parallel_workers = 0;
2145 2718 : pathnode->path.rows = rows;
2146 2718 : pathnode->path.startup_cost = startup_cost;
2147 2718 : pathnode->path.total_cost = total_cost;
2148 2718 : pathnode->path.pathkeys = pathkeys;
2149 :
2150 2718 : pathnode->fdw_outerpath = fdw_outerpath;
2151 2718 : pathnode->fdw_private = fdw_private;
2152 :
2153 2718 : return pathnode;
2154 : }
2155 :
2156 : /*
2157 : * create_foreign_join_path
2158 : * Creates a path corresponding to a scan of a foreign join,
2159 : * returning the pathnode.
2160 : *
2161 : * This function is never called from core Postgres; rather, it's expected
2162 : * to be called by the GetForeignJoinPaths function of a foreign data wrapper.
2163 : * We make the FDW supply all fields of the path, since we do not have any way
2164 : * to calculate them in core. However, there is a usually-sane default for
2165 : * the pathtarget (rel->reltarget), so we let a NULL for "target" select that.
2166 : */
2167 : ForeignPath *
2168 702 : create_foreign_join_path(PlannerInfo *root, RelOptInfo *rel,
2169 : PathTarget *target,
2170 : double rows, Cost startup_cost, Cost total_cost,
2171 : List *pathkeys,
2172 : Relids required_outer,
2173 : Path *fdw_outerpath,
2174 : List *fdw_private)
2175 : {
2176 702 : ForeignPath *pathnode = makeNode(ForeignPath);
2177 :
2178 : /*
2179 : * We should use get_joinrel_parampathinfo to handle parameterized paths,
2180 : * but the API of this function doesn't support it, and existing
2181 : * extensions aren't yet trying to build such paths anyway. For the
2182 : * moment just throw an error if someone tries it; eventually we should
2183 : * revisit this.
2184 : */
2185 702 : if (!bms_is_empty(required_outer) || !bms_is_empty(rel->lateral_relids))
2186 0 : elog(ERROR, "parameterized foreign joins are not supported yet");
2187 :
2188 702 : pathnode->path.pathtype = T_ForeignScan;
2189 702 : pathnode->path.parent = rel;
2190 702 : pathnode->path.pathtarget = target ? target : rel->reltarget;
2191 702 : pathnode->path.param_info = NULL; /* XXX see above */
2192 702 : pathnode->path.parallel_aware = false;
2193 702 : pathnode->path.parallel_safe = rel->consider_parallel;
2194 702 : pathnode->path.parallel_workers = 0;
2195 702 : pathnode->path.rows = rows;
2196 702 : pathnode->path.startup_cost = startup_cost;
2197 702 : pathnode->path.total_cost = total_cost;
2198 702 : pathnode->path.pathkeys = pathkeys;
2199 :
2200 702 : pathnode->fdw_outerpath = fdw_outerpath;
2201 702 : pathnode->fdw_private = fdw_private;
2202 :
2203 702 : return pathnode;
2204 : }
2205 :
2206 : /*
2207 : * create_foreign_upper_path
2208 : * Creates a path corresponding to an upper relation that's computed
2209 : * directly by an FDW, returning the pathnode.
2210 : *
2211 : * This function is never called from core Postgres; rather, it's expected to
2212 : * be called by the GetForeignUpperPaths function of a foreign data wrapper.
2213 : * We make the FDW supply all fields of the path, since we do not have any way
2214 : * to calculate them in core. However, there is a usually-sane default for
2215 : * the pathtarget (rel->reltarget), so we let a NULL for "target" select that.
2216 : */
2217 : ForeignPath *
2218 448 : create_foreign_upper_path(PlannerInfo *root, RelOptInfo *rel,
2219 : PathTarget *target,
2220 : double rows, Cost startup_cost, Cost total_cost,
2221 : List *pathkeys,
2222 : Path *fdw_outerpath,
2223 : List *fdw_private)
2224 : {
2225 448 : ForeignPath *pathnode = makeNode(ForeignPath);
2226 :
2227 : /*
2228 : * Upper relations should never have any lateral references, since joining
2229 : * is complete.
2230 : */
2231 : Assert(bms_is_empty(rel->lateral_relids));
2232 :
2233 448 : pathnode->path.pathtype = T_ForeignScan;
2234 448 : pathnode->path.parent = rel;
2235 448 : pathnode->path.pathtarget = target ? target : rel->reltarget;
2236 448 : pathnode->path.param_info = NULL;
2237 448 : pathnode->path.parallel_aware = false;
2238 448 : pathnode->path.parallel_safe = rel->consider_parallel;
2239 448 : pathnode->path.parallel_workers = 0;
2240 448 : pathnode->path.rows = rows;
2241 448 : pathnode->path.startup_cost = startup_cost;
2242 448 : pathnode->path.total_cost = total_cost;
2243 448 : pathnode->path.pathkeys = pathkeys;
2244 :
2245 448 : pathnode->fdw_outerpath = fdw_outerpath;
2246 448 : pathnode->fdw_private = fdw_private;
2247 :
2248 448 : return pathnode;
2249 : }
2250 :
2251 : /*
2252 : * calc_nestloop_required_outer
2253 : * Compute the required_outer set for a nestloop join path
2254 : *
2255 : * Note: result must not share storage with either input
2256 : */
2257 : Relids
2258 1085450 : calc_nestloop_required_outer(Relids outerrelids,
2259 : Relids outer_paramrels,
2260 : Relids innerrelids,
2261 : Relids inner_paramrels)
2262 : {
2263 : Relids required_outer;
2264 :
2265 : /* inner_path can require rels from outer path, but not vice versa */
2266 : Assert(!bms_overlap(outer_paramrels, innerrelids));
2267 : /* easy case if inner path is not parameterized */
2268 1085450 : if (!inner_paramrels)
2269 839096 : return bms_copy(outer_paramrels);
2270 : /* else, form the union ... */
2271 246354 : required_outer = bms_union(outer_paramrels, inner_paramrels);
2272 : /* ... and remove any mention of now-satisfied outer rels */
2273 246354 : required_outer = bms_del_members(required_outer,
2274 : outerrelids);
2275 : /* maintain invariant that required_outer is exactly NULL if empty */
2276 246354 : if (bms_is_empty(required_outer))
2277 : {
2278 201250 : bms_free(required_outer);
2279 201250 : required_outer = NULL;
2280 : }
2281 246354 : return required_outer;
2282 : }
2283 :
2284 : /*
2285 : * calc_non_nestloop_required_outer
2286 : * Compute the required_outer set for a merge or hash join path
2287 : *
2288 : * Note: result must not share storage with either input
2289 : */
2290 : Relids
2291 770540 : calc_non_nestloop_required_outer(Path *outer_path, Path *inner_path)
2292 : {
2293 770540 : Relids outer_paramrels = PATH_REQ_OUTER(outer_path);
2294 770540 : Relids inner_paramrels = PATH_REQ_OUTER(inner_path);
2295 : Relids required_outer;
2296 :
2297 : /* neither path can require rels from the other */
2298 : Assert(!bms_overlap(outer_paramrels, inner_path->parent->relids));
2299 : Assert(!bms_overlap(inner_paramrels, outer_path->parent->relids));
2300 : /* form the union ... */
2301 770540 : required_outer = bms_union(outer_paramrels, inner_paramrels);
2302 : /* we do not need an explicit test for empty; bms_union gets it right */
2303 770540 : return required_outer;
2304 : }
2305 :
2306 : /*
2307 : * create_nestloop_path
2308 : * Creates a pathnode corresponding to a nestloop join between two
2309 : * relations.
2310 : *
2311 : * 'joinrel' is the join relation.
2312 : * 'jointype' is the type of join required
2313 : * 'workspace' is the result from initial_cost_nestloop
2314 : * 'extra' contains various information about the join
2315 : * 'outer_path' is the outer path
2316 : * 'inner_path' is the inner path
2317 : * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
2318 : * 'pathkeys' are the path keys of the new join path
2319 : * 'required_outer' is the set of required outer rels
2320 : *
2321 : * Returns the resulting path node.
2322 : */
2323 : NestPath *
2324 569384 : create_nestloop_path(PlannerInfo *root,
2325 : RelOptInfo *joinrel,
2326 : JoinType jointype,
2327 : JoinCostWorkspace *workspace,
2328 : JoinPathExtraData *extra,
2329 : Path *outer_path,
2330 : Path *inner_path,
2331 : List *restrict_clauses,
2332 : List *pathkeys,
2333 : Relids required_outer)
2334 : {
2335 569384 : NestPath *pathnode = makeNode(NestPath);
2336 569384 : Relids inner_req_outer = PATH_REQ_OUTER(inner_path);
2337 :
2338 : /*
2339 : * If the inner path is parameterized by the outer, we must drop any
2340 : * restrict_clauses that are due to be moved into the inner path. We have
2341 : * to do this now, rather than postpone the work till createplan time,
2342 : * because the restrict_clauses list can affect the size and cost
2343 : * estimates for this path.
2344 : */
2345 569384 : if (bms_overlap(inner_req_outer, outer_path->parent->relids))
2346 : {
2347 110614 : Relids inner_and_outer = bms_union(inner_path->parent->relids,
2348 : inner_req_outer);
2349 110614 : List *jclauses = NIL;
2350 : ListCell *lc;
2351 :
2352 230054 : foreach(lc, restrict_clauses)
2353 : {
2354 119440 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2355 :
2356 119440 : if (!join_clause_is_movable_into(rinfo,
2357 119440 : inner_path->parent->relids,
2358 : inner_and_outer))
2359 7530 : jclauses = lappend(jclauses, rinfo);
2360 : }
2361 110614 : restrict_clauses = jclauses;
2362 : }
2363 :
2364 569384 : pathnode->path.pathtype = T_NestLoop;
2365 569384 : pathnode->path.parent = joinrel;
2366 569384 : pathnode->path.pathtarget = joinrel->reltarget;
2367 569384 : pathnode->path.param_info =
2368 569384 : get_joinrel_parampathinfo(root,
2369 : joinrel,
2370 : outer_path,
2371 : inner_path,
2372 : extra->sjinfo,
2373 : required_outer,
2374 : &restrict_clauses);
2375 569384 : pathnode->path.parallel_aware = false;
2376 1649570 : pathnode->path.parallel_safe = joinrel->consider_parallel &&
2377 1079558 : outer_path->parallel_safe && inner_path->parallel_safe;
2378 : /* This is a foolish way to estimate parallel_workers, but for now... */
2379 569384 : pathnode->path.parallel_workers = outer_path->parallel_workers;
2380 569384 : pathnode->path.pathkeys = pathkeys;
2381 569384 : pathnode->jointype = jointype;
2382 569384 : pathnode->inner_unique = extra->inner_unique;
2383 569384 : pathnode->outerjoinpath = outer_path;
2384 569384 : pathnode->innerjoinpath = inner_path;
2385 569384 : pathnode->joinrestrictinfo = restrict_clauses;
2386 :
2387 569384 : final_cost_nestloop(root, pathnode, workspace, extra);
2388 :
2389 569384 : return pathnode;
2390 : }
2391 :
2392 : /*
2393 : * create_mergejoin_path
2394 : * Creates a pathnode corresponding to a mergejoin join between
2395 : * two relations
2396 : *
2397 : * 'joinrel' is the join relation
2398 : * 'jointype' is the type of join required
2399 : * 'workspace' is the result from initial_cost_mergejoin
2400 : * 'extra' contains various information about the join
2401 : * 'outer_path' is the outer path
2402 : * 'inner_path' is the inner path
2403 : * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
2404 : * 'pathkeys' are the path keys of the new join path
2405 : * 'required_outer' is the set of required outer rels
2406 : * 'mergeclauses' are the RestrictInfo nodes to use as merge clauses
2407 : * (this should be a subset of the restrict_clauses list)
2408 : * 'outersortkeys' are the sort varkeys for the outer relation
2409 : * 'innersortkeys' are the sort varkeys for the inner relation
2410 : */
2411 : MergePath *
2412 116436 : create_mergejoin_path(PlannerInfo *root,
2413 : RelOptInfo *joinrel,
2414 : JoinType jointype,
2415 : JoinCostWorkspace *workspace,
2416 : JoinPathExtraData *extra,
2417 : Path *outer_path,
2418 : Path *inner_path,
2419 : List *restrict_clauses,
2420 : List *pathkeys,
2421 : Relids required_outer,
2422 : List *mergeclauses,
2423 : List *outersortkeys,
2424 : List *innersortkeys)
2425 : {
2426 116436 : MergePath *pathnode = makeNode(MergePath);
2427 :
2428 116436 : pathnode->jpath.path.pathtype = T_MergeJoin;
2429 116436 : pathnode->jpath.path.parent = joinrel;
2430 116436 : pathnode->jpath.path.pathtarget = joinrel->reltarget;
2431 116436 : pathnode->jpath.path.param_info =
2432 116436 : get_joinrel_parampathinfo(root,
2433 : joinrel,
2434 : outer_path,
2435 : inner_path,
2436 : extra->sjinfo,
2437 : required_outer,
2438 : &restrict_clauses);
2439 116436 : pathnode->jpath.path.parallel_aware = false;
2440 329284 : pathnode->jpath.path.parallel_safe = joinrel->consider_parallel &&
2441 212748 : outer_path->parallel_safe && inner_path->parallel_safe;
2442 : /* This is a foolish way to estimate parallel_workers, but for now... */
2443 116436 : pathnode->jpath.path.parallel_workers = outer_path->parallel_workers;
2444 116436 : pathnode->jpath.path.pathkeys = pathkeys;
2445 116436 : pathnode->jpath.jointype = jointype;
2446 116436 : pathnode->jpath.inner_unique = extra->inner_unique;
2447 116436 : pathnode->jpath.outerjoinpath = outer_path;
2448 116436 : pathnode->jpath.innerjoinpath = inner_path;
2449 116436 : pathnode->jpath.joinrestrictinfo = restrict_clauses;
2450 116436 : pathnode->path_mergeclauses = mergeclauses;
2451 116436 : pathnode->outersortkeys = outersortkeys;
2452 116436 : pathnode->innersortkeys = innersortkeys;
2453 : /* pathnode->skip_mark_restore will be set by final_cost_mergejoin */
2454 : /* pathnode->materialize_inner will be set by final_cost_mergejoin */
2455 :
2456 116436 : final_cost_mergejoin(root, pathnode, workspace, extra);
2457 :
2458 116436 : return pathnode;
2459 : }
2460 :
2461 : /*
2462 : * create_hashjoin_path
2463 : * Creates a pathnode corresponding to a hash join between two relations.
2464 : *
2465 : * 'joinrel' is the join relation
2466 : * 'jointype' is the type of join required
2467 : * 'workspace' is the result from initial_cost_hashjoin
2468 : * 'extra' contains various information about the join
2469 : * 'outer_path' is the cheapest outer path
2470 : * 'inner_path' is the cheapest inner path
2471 : * 'parallel_hash' to select Parallel Hash of inner path (shared hash table)
2472 : * 'restrict_clauses' are the RestrictInfo nodes to apply at the join
2473 : * 'required_outer' is the set of required outer rels
2474 : * 'hashclauses' are the RestrictInfo nodes to use as hash clauses
2475 : * (this should be a subset of the restrict_clauses list)
2476 : */
2477 : HashPath *
2478 133400 : create_hashjoin_path(PlannerInfo *root,
2479 : RelOptInfo *joinrel,
2480 : JoinType jointype,
2481 : JoinCostWorkspace *workspace,
2482 : JoinPathExtraData *extra,
2483 : Path *outer_path,
2484 : Path *inner_path,
2485 : bool parallel_hash,
2486 : List *restrict_clauses,
2487 : Relids required_outer,
2488 : List *hashclauses)
2489 : {
2490 133400 : HashPath *pathnode = makeNode(HashPath);
2491 :
2492 133400 : pathnode->jpath.path.pathtype = T_HashJoin;
2493 133400 : pathnode->jpath.path.parent = joinrel;
2494 133400 : pathnode->jpath.path.pathtarget = joinrel->reltarget;
2495 133400 : pathnode->jpath.path.param_info =
2496 133400 : get_joinrel_parampathinfo(root,
2497 : joinrel,
2498 : outer_path,
2499 : inner_path,
2500 : extra->sjinfo,
2501 : required_outer,
2502 : &restrict_clauses);
2503 133400 : pathnode->jpath.path.parallel_aware =
2504 133400 : joinrel->consider_parallel && parallel_hash;
2505 376336 : pathnode->jpath.path.parallel_safe = joinrel->consider_parallel &&
2506 242614 : outer_path->parallel_safe && inner_path->parallel_safe;
2507 : /* This is a foolish way to estimate parallel_workers, but for now... */
2508 133400 : pathnode->jpath.path.parallel_workers = outer_path->parallel_workers;
2509 :
2510 : /*
2511 : * A hashjoin never has pathkeys, since its output ordering is
2512 : * unpredictable due to possible batching. XXX If the inner relation is
2513 : * small enough, we could instruct the executor that it must not batch,
2514 : * and then we could assume that the output inherits the outer relation's
2515 : * ordering, which might save a sort step. However there is considerable
2516 : * downside if our estimate of the inner relation size is badly off. For
2517 : * the moment we don't risk it. (Note also that if we wanted to take this
2518 : * seriously, joinpath.c would have to consider many more paths for the
2519 : * outer rel than it does now.)
2520 : */
2521 133400 : pathnode->jpath.path.pathkeys = NIL;
2522 133400 : pathnode->jpath.jointype = jointype;
2523 133400 : pathnode->jpath.inner_unique = extra->inner_unique;
2524 133400 : pathnode->jpath.outerjoinpath = outer_path;
2525 133400 : pathnode->jpath.innerjoinpath = inner_path;
2526 133400 : pathnode->jpath.joinrestrictinfo = restrict_clauses;
2527 133400 : pathnode->path_hashclauses = hashclauses;
2528 : /* final_cost_hashjoin will fill in pathnode->num_batches */
2529 :
2530 133400 : final_cost_hashjoin(root, pathnode, workspace, extra);
2531 :
2532 133400 : return pathnode;
2533 : }
2534 :
2535 : /*
2536 : * create_projection_path
2537 : * Creates a pathnode that represents performing a projection.
2538 : *
2539 : * 'rel' is the parent relation associated with the result
2540 : * 'subpath' is the path representing the source of data
2541 : * 'target' is the PathTarget to be computed
2542 : */
2543 : ProjectionPath *
2544 225894 : create_projection_path(PlannerInfo *root,
2545 : RelOptInfo *rel,
2546 : Path *subpath,
2547 : PathTarget *target)
2548 : {
2549 225894 : ProjectionPath *pathnode = makeNode(ProjectionPath);
2550 225894 : PathTarget *oldtarget = subpath->pathtarget;
2551 :
2552 225894 : pathnode->path.pathtype = T_Result;
2553 225894 : pathnode->path.parent = rel;
2554 225894 : pathnode->path.pathtarget = target;
2555 : /* For now, assume we are above any joins, so no parameterization */
2556 225894 : pathnode->path.param_info = NULL;
2557 225894 : pathnode->path.parallel_aware = false;
2558 485010 : pathnode->path.parallel_safe = rel->consider_parallel &&
2559 258484 : subpath->parallel_safe &&
2560 32590 : is_parallel_safe(root, (Node *) target->exprs);
2561 225894 : pathnode->path.parallel_workers = subpath->parallel_workers;
2562 : /* Projection does not change the sort order */
2563 225894 : pathnode->path.pathkeys = subpath->pathkeys;
2564 :
2565 225894 : pathnode->subpath = subpath;
2566 :
2567 : /*
2568 : * We might not need a separate Result node. If the input plan node type
2569 : * can project, we can just tell it to project something else. Or, if it
2570 : * can't project but the desired target has the same expression list as
2571 : * what the input will produce anyway, we can still give it the desired
2572 : * tlist (possibly changing its ressortgroupref labels, but nothing else).
2573 : * Note: in the latter case, create_projection_plan has to recheck our
2574 : * conclusion; see comments therein.
2575 : */
2576 234266 : if (is_projection_capable_path(subpath) ||
2577 8372 : equal(oldtarget->exprs, target->exprs))
2578 : {
2579 : /* No separate Result node needed */
2580 224776 : pathnode->dummypp = true;
2581 :
2582 : /*
2583 : * Set cost of plan as subpath's cost, adjusted for tlist replacement.
2584 : */
2585 224776 : pathnode->path.rows = subpath->rows;
2586 449552 : pathnode->path.startup_cost = subpath->startup_cost +
2587 224776 : (target->cost.startup - oldtarget->cost.startup);
2588 674328 : pathnode->path.total_cost = subpath->total_cost +
2589 449552 : (target->cost.startup - oldtarget->cost.startup) +
2590 224776 : (target->cost.per_tuple - oldtarget->cost.per_tuple) * subpath->rows;
2591 : }
2592 : else
2593 : {
2594 : /* We really do need the Result node */
2595 1118 : pathnode->dummypp = false;
2596 :
2597 : /*
2598 : * The Result node's cost is cpu_tuple_cost per row, plus the cost of
2599 : * evaluating the tlist. There is no qual to worry about.
2600 : */
2601 1118 : pathnode->path.rows = subpath->rows;
2602 2236 : pathnode->path.startup_cost = subpath->startup_cost +
2603 1118 : target->cost.startup;
2604 3354 : pathnode->path.total_cost = subpath->total_cost +
2605 2236 : target->cost.startup +
2606 1118 : (cpu_tuple_cost + target->cost.per_tuple) * subpath->rows;
2607 : }
2608 :
2609 225894 : return pathnode;
2610 : }
2611 :
2612 : /*
2613 : * apply_projection_to_path
2614 : * Add a projection step, or just apply the target directly to given path.
2615 : *
2616 : * This has the same net effect as create_projection_path(), except that if
2617 : * a separate Result plan node isn't needed, we just replace the given path's
2618 : * pathtarget with the desired one. This must be used only when the caller
2619 : * knows that the given path isn't referenced elsewhere and so can be modified
2620 : * in-place.
2621 : *
2622 : * If the input path is a GatherPath or GatherMergePath, we try to push the
2623 : * new target down to its input as well; this is a yet more invasive
2624 : * modification of the input path, which create_projection_path() can't do.
2625 : *
2626 : * Note that we mustn't change the source path's parent link; so when it is
2627 : * add_path'd to "rel" things will be a bit inconsistent. So far that has
2628 : * not caused any trouble.
2629 : *
2630 : * 'rel' is the parent relation associated with the result
2631 : * 'path' is the path representing the source of data
2632 : * 'target' is the PathTarget to be computed
2633 : */
2634 : Path *
2635 14392 : apply_projection_to_path(PlannerInfo *root,
2636 : RelOptInfo *rel,
2637 : Path *path,
2638 : PathTarget *target)
2639 : {
2640 : QualCost oldcost;
2641 :
2642 : /*
2643 : * If given path can't project, we might need a Result node, so make a
2644 : * separate ProjectionPath.
2645 : */
2646 14392 : if (!is_projection_capable_path(path))
2647 6812 : return (Path *) create_projection_path(root, rel, path, target);
2648 :
2649 : /*
2650 : * We can just jam the desired tlist into the existing path, being sure to
2651 : * update its cost estimates appropriately.
2652 : */
2653 7580 : oldcost = path->pathtarget->cost;
2654 7580 : path->pathtarget = target;
2655 :
2656 7580 : path->startup_cost += target->cost.startup - oldcost.startup;
2657 15160 : path->total_cost += target->cost.startup - oldcost.startup +
2658 7580 : (target->cost.per_tuple - oldcost.per_tuple) * path->rows;
2659 :
2660 : /*
2661 : * If the path happens to be a Gather or GatherMerge path, we'd like to
2662 : * arrange for the subpath to return the required target list so that
2663 : * workers can help project. But if there is something that is not
2664 : * parallel-safe in the target expressions, then we can't.
2665 : */
2666 8758 : if ((IsA(path, GatherPath) ||IsA(path, GatherMergePath)) &&
2667 1178 : is_parallel_safe(root, (Node *) target->exprs))
2668 : {
2669 : /*
2670 : * We always use create_projection_path here, even if the subpath is
2671 : * projection-capable, so as to avoid modifying the subpath in place.
2672 : * It seems unlikely at present that there could be any other
2673 : * references to the subpath, but better safe than sorry.
2674 : *
2675 : * Note that we don't change the parallel path's cost estimates; it
2676 : * might be appropriate to do so, to reflect the fact that the bulk of
2677 : * the target evaluation will happen in workers.
2678 : */
2679 2356 : if (IsA(path, GatherPath))
2680 : {
2681 0 : GatherPath *gpath = (GatherPath *) path;
2682 :
2683 0 : gpath->subpath = (Path *)
2684 0 : create_projection_path(root,
2685 0 : gpath->subpath->parent,
2686 : gpath->subpath,
2687 : target);
2688 : }
2689 : else
2690 : {
2691 1178 : GatherMergePath *gmpath = (GatherMergePath *) path;
2692 :
2693 1178 : gmpath->subpath = (Path *)
2694 2356 : create_projection_path(root,
2695 1178 : gmpath->subpath->parent,
2696 : gmpath->subpath,
2697 : target);
2698 : }
2699 : }
2700 9198 : else if (path->parallel_safe &&
2701 2796 : !is_parallel_safe(root, (Node *) target->exprs))
2702 : {
2703 : /*
2704 : * We're inserting a parallel-restricted target list into a path
2705 : * currently marked parallel-safe, so we have to mark it as no longer
2706 : * safe.
2707 : */
2708 8 : path->parallel_safe = false;
2709 : }
2710 :
2711 7580 : return path;
2712 : }
2713 :
2714 : /*
2715 : * create_set_projection_path
2716 : * Creates a pathnode that represents performing a projection that
2717 : * includes set-returning functions.
2718 : *
2719 : * 'rel' is the parent relation associated with the result
2720 : * 'subpath' is the path representing the source of data
2721 : * 'target' is the PathTarget to be computed
2722 : */
2723 : ProjectSetPath *
2724 3316 : create_set_projection_path(PlannerInfo *root,
2725 : RelOptInfo *rel,
2726 : Path *subpath,
2727 : PathTarget *target)
2728 : {
2729 3316 : ProjectSetPath *pathnode = makeNode(ProjectSetPath);
2730 : double tlist_rows;
2731 : ListCell *lc;
2732 :
2733 3316 : pathnode->path.pathtype = T_ProjectSet;
2734 3316 : pathnode->path.parent = rel;
2735 3316 : pathnode->path.pathtarget = target;
2736 : /* For now, assume we are above any joins, so no parameterization */
2737 3316 : pathnode->path.param_info = NULL;
2738 3316 : pathnode->path.parallel_aware = false;
2739 7050 : pathnode->path.parallel_safe = rel->consider_parallel &&
2740 3714 : subpath->parallel_safe &&
2741 398 : is_parallel_safe(root, (Node *) target->exprs);
2742 3316 : pathnode->path.parallel_workers = subpath->parallel_workers;
2743 : /* Projection does not change the sort order XXX? */
2744 3316 : pathnode->path.pathkeys = subpath->pathkeys;
2745 :
2746 3316 : pathnode->subpath = subpath;
2747 :
2748 : /*
2749 : * Estimate number of rows produced by SRFs for each row of input; if
2750 : * there's more than one in this node, use the maximum.
2751 : */
2752 3316 : tlist_rows = 1;
2753 7766 : foreach(lc, target->exprs)
2754 : {
2755 4450 : Node *node = (Node *) lfirst(lc);
2756 : double itemrows;
2757 :
2758 4450 : itemrows = expression_returns_set_rows(root, node);
2759 4450 : if (tlist_rows < itemrows)
2760 3186 : tlist_rows = itemrows;
2761 : }
2762 :
2763 : /*
2764 : * In addition to the cost of evaluating the tlist, charge cpu_tuple_cost
2765 : * per input row, and half of cpu_tuple_cost for each added output row.
2766 : * This is slightly bizarre maybe, but it's what 9.6 did; we may revisit
2767 : * this estimate later.
2768 : */
2769 3316 : pathnode->path.rows = subpath->rows * tlist_rows;
2770 6632 : pathnode->path.startup_cost = subpath->startup_cost +
2771 3316 : target->cost.startup;
2772 9948 : pathnode->path.total_cost = subpath->total_cost +
2773 6632 : target->cost.startup +
2774 6632 : (cpu_tuple_cost + target->cost.per_tuple) * subpath->rows +
2775 3316 : (pathnode->path.rows - subpath->rows) * cpu_tuple_cost / 2;
2776 :
2777 3316 : return pathnode;
2778 : }
2779 :
2780 : /*
2781 : * create_sort_path
2782 : * Creates a pathnode that represents performing an explicit sort.
2783 : *
2784 : * 'rel' is the parent relation associated with the result
2785 : * 'subpath' is the path representing the source of data
2786 : * 'pathkeys' represents the desired sort order
2787 : * 'limit_tuples' is the estimated bound on the number of output tuples,
2788 : * or -1 if no LIMIT or couldn't estimate
2789 : */
2790 : SortPath *
2791 35216 : create_sort_path(PlannerInfo *root,
2792 : RelOptInfo *rel,
2793 : Path *subpath,
2794 : List *pathkeys,
2795 : double limit_tuples)
2796 : {
2797 35216 : SortPath *pathnode = makeNode(SortPath);
2798 :
2799 35216 : pathnode->path.pathtype = T_Sort;
2800 35216 : pathnode->path.parent = rel;
2801 : /* Sort doesn't project, so use source path's pathtarget */
2802 35216 : pathnode->path.pathtarget = subpath->pathtarget;
2803 : /* For now, assume we are above any joins, so no parameterization */
2804 35216 : pathnode->path.param_info = NULL;
2805 35216 : pathnode->path.parallel_aware = false;
2806 53264 : pathnode->path.parallel_safe = rel->consider_parallel &&
2807 18048 : subpath->parallel_safe;
2808 35216 : pathnode->path.parallel_workers = subpath->parallel_workers;
2809 35216 : pathnode->path.pathkeys = pathkeys;
2810 :
2811 35216 : pathnode->subpath = subpath;
2812 :
2813 70432 : cost_sort(&pathnode->path, root, pathkeys,
2814 : subpath->total_cost,
2815 : subpath->rows,
2816 35216 : subpath->pathtarget->width,
2817 : 0.0, /* XXX comparison_cost shouldn't be 0? */
2818 : work_mem, limit_tuples);
2819 :
2820 35216 : return pathnode;
2821 : }
2822 :
2823 : /*
2824 : * create_group_path
2825 : * Creates a pathnode that represents performing grouping of presorted input
2826 : *
2827 : * 'rel' is the parent relation associated with the result
2828 : * 'subpath' is the path representing the source of data
2829 : * 'target' is the PathTarget to be computed
2830 : * 'groupClause' is a list of SortGroupClause's representing the grouping
2831 : * 'qual' is the HAVING quals if any
2832 : * 'numGroups' is the estimated number of groups
2833 : */
2834 : GroupPath *
2835 432 : create_group_path(PlannerInfo *root,
2836 : RelOptInfo *rel,
2837 : Path *subpath,
2838 : List *groupClause,
2839 : List *qual,
2840 : double numGroups)
2841 : {
2842 432 : GroupPath *pathnode = makeNode(GroupPath);
2843 432 : PathTarget *target = rel->reltarget;
2844 :
2845 432 : pathnode->path.pathtype = T_Group;
2846 432 : pathnode->path.parent = rel;
2847 432 : pathnode->path.pathtarget = target;
2848 : /* For now, assume we are above any joins, so no parameterization */
2849 432 : pathnode->path.param_info = NULL;
2850 432 : pathnode->path.parallel_aware = false;
2851 654 : pathnode->path.parallel_safe = rel->consider_parallel &&
2852 222 : subpath->parallel_safe;
2853 432 : pathnode->path.parallel_workers = subpath->parallel_workers;
2854 : /* Group doesn't change sort ordering */
2855 432 : pathnode->path.pathkeys = subpath->pathkeys;
2856 :
2857 432 : pathnode->subpath = subpath;
2858 :
2859 432 : pathnode->groupClause = groupClause;
2860 432 : pathnode->qual = qual;
2861 :
2862 432 : cost_group(&pathnode->path, root,
2863 : list_length(groupClause),
2864 : numGroups,
2865 : qual,
2866 : subpath->startup_cost, subpath->total_cost,
2867 : subpath->rows);
2868 :
2869 : /* add tlist eval cost for each output row */
2870 432 : pathnode->path.startup_cost += target->cost.startup;
2871 864 : pathnode->path.total_cost += target->cost.startup +
2872 432 : target->cost.per_tuple * pathnode->path.rows;
2873 :
2874 432 : return pathnode;
2875 : }
2876 :
2877 : /*
2878 : * create_upper_unique_path
2879 : * Creates a pathnode that represents performing an explicit Unique step
2880 : * on presorted input.
2881 : *
2882 : * This produces a Unique plan node, but the use-case is so different from
2883 : * create_unique_path that it doesn't seem worth trying to merge the two.
2884 : *
2885 : * 'rel' is the parent relation associated with the result
2886 : * 'subpath' is the path representing the source of data
2887 : * 'numCols' is the number of grouping columns
2888 : * 'numGroups' is the estimated number of groups
2889 : *
2890 : * The input path must be sorted on the grouping columns, plus possibly
2891 : * additional columns; so the first numCols pathkeys are the grouping columns
2892 : */
2893 : UpperUniquePath *
2894 526 : create_upper_unique_path(PlannerInfo *root,
2895 : RelOptInfo *rel,
2896 : Path *subpath,
2897 : int numCols,
2898 : double numGroups)
2899 : {
2900 526 : UpperUniquePath *pathnode = makeNode(UpperUniquePath);
2901 :
2902 526 : pathnode->path.pathtype = T_Unique;
2903 526 : pathnode->path.parent = rel;
2904 : /* Unique doesn't project, so use source path's pathtarget */
2905 526 : pathnode->path.pathtarget = subpath->pathtarget;
2906 : /* For now, assume we are above any joins, so no parameterization */
2907 526 : pathnode->path.param_info = NULL;
2908 526 : pathnode->path.parallel_aware = false;
2909 878 : pathnode->path.parallel_safe = rel->consider_parallel &&
2910 352 : subpath->parallel_safe;
2911 526 : pathnode->path.parallel_workers = subpath->parallel_workers;
2912 : /* Unique doesn't change the input ordering */
2913 526 : pathnode->path.pathkeys = subpath->pathkeys;
2914 :
2915 526 : pathnode->subpath = subpath;
2916 526 : pathnode->numkeys = numCols;
2917 :
2918 : /*
2919 : * Charge one cpu_operator_cost per comparison per input tuple. We assume
2920 : * all columns get compared at most of the tuples. (XXX probably this is
2921 : * an overestimate.)
2922 : */
2923 526 : pathnode->path.startup_cost = subpath->startup_cost;
2924 1052 : pathnode->path.total_cost = subpath->total_cost +
2925 526 : cpu_operator_cost * subpath->rows * numCols;
2926 526 : pathnode->path.rows = numGroups;
2927 :
2928 526 : return pathnode;
2929 : }
2930 :
2931 : /*
2932 : * create_agg_path
2933 : * Creates a pathnode that represents performing aggregation/grouping
2934 : *
2935 : * 'rel' is the parent relation associated with the result
2936 : * 'subpath' is the path representing the source of data
2937 : * 'target' is the PathTarget to be computed
2938 : * 'aggstrategy' is the Agg node's basic implementation strategy
2939 : * 'aggsplit' is the Agg node's aggregate-splitting mode
2940 : * 'groupClause' is a list of SortGroupClause's representing the grouping
2941 : * 'qual' is the HAVING quals if any
2942 : * 'aggcosts' contains cost info about the aggregate functions to be computed
2943 : * 'numGroups' is the estimated number of groups (1 if not grouping)
2944 : */
2945 : AggPath *
2946 31608 : create_agg_path(PlannerInfo *root,
2947 : RelOptInfo *rel,
2948 : Path *subpath,
2949 : PathTarget *target,
2950 : AggStrategy aggstrategy,
2951 : AggSplit aggsplit,
2952 : List *groupClause,
2953 : List *qual,
2954 : const AggClauseCosts *aggcosts,
2955 : double numGroups)
2956 : {
2957 31608 : AggPath *pathnode = makeNode(AggPath);
2958 :
2959 31608 : pathnode->path.pathtype = T_Agg;
2960 31608 : pathnode->path.parent = rel;
2961 31608 : pathnode->path.pathtarget = target;
2962 : /* For now, assume we are above any joins, so no parameterization */
2963 31608 : pathnode->path.param_info = NULL;
2964 31608 : pathnode->path.parallel_aware = false;
2965 47510 : pathnode->path.parallel_safe = rel->consider_parallel &&
2966 15902 : subpath->parallel_safe;
2967 31608 : pathnode->path.parallel_workers = subpath->parallel_workers;
2968 31608 : if (aggstrategy == AGG_SORTED)
2969 4062 : pathnode->path.pathkeys = subpath->pathkeys; /* preserves order */
2970 : else
2971 27546 : pathnode->path.pathkeys = NIL; /* output is unordered */
2972 31608 : pathnode->subpath = subpath;
2973 :
2974 31608 : pathnode->aggstrategy = aggstrategy;
2975 31608 : pathnode->aggsplit = aggsplit;
2976 31608 : pathnode->numGroups = numGroups;
2977 31608 : pathnode->groupClause = groupClause;
2978 31608 : pathnode->qual = qual;
2979 :
2980 31608 : cost_agg(&pathnode->path, root,
2981 : aggstrategy, aggcosts,
2982 : list_length(groupClause), numGroups,
2983 : qual,
2984 : subpath->startup_cost, subpath->total_cost,
2985 : subpath->rows);
2986 :
2987 : /* add tlist eval cost for each output row */
2988 31608 : pathnode->path.startup_cost += target->cost.startup;
2989 63216 : pathnode->path.total_cost += target->cost.startup +
2990 31608 : target->cost.per_tuple * pathnode->path.rows;
2991 :
2992 31608 : return pathnode;
2993 : }
2994 :
2995 : /*
2996 : * create_groupingsets_path
2997 : * Creates a pathnode that represents performing GROUPING SETS aggregation
2998 : *
2999 : * GroupingSetsPath represents sorted grouping with one or more grouping sets.
3000 : * The input path's result must be sorted to match the last entry in
3001 : * rollup_groupclauses.
3002 : *
3003 : * 'rel' is the parent relation associated with the result
3004 : * 'subpath' is the path representing the source of data
3005 : * 'target' is the PathTarget to be computed
3006 : * 'having_qual' is the HAVING quals if any
3007 : * 'rollups' is a list of RollupData nodes
3008 : * 'agg_costs' contains cost info about the aggregate functions to be computed
3009 : * 'numGroups' is the estimated total number of groups
3010 : */
3011 : GroupingSetsPath *
3012 948 : create_groupingsets_path(PlannerInfo *root,
3013 : RelOptInfo *rel,
3014 : Path *subpath,
3015 : List *having_qual,
3016 : AggStrategy aggstrategy,
3017 : List *rollups,
3018 : const AggClauseCosts *agg_costs,
3019 : double numGroups)
3020 : {
3021 948 : GroupingSetsPath *pathnode = makeNode(GroupingSetsPath);
3022 948 : PathTarget *target = rel->reltarget;
3023 : ListCell *lc;
3024 948 : bool is_first = true;
3025 948 : bool is_first_sort = true;
3026 :
3027 : /* The topmost generated Plan node will be an Agg */
3028 948 : pathnode->path.pathtype = T_Agg;
3029 948 : pathnode->path.parent = rel;
3030 948 : pathnode->path.pathtarget = target;
3031 948 : pathnode->path.param_info = subpath->param_info;
3032 948 : pathnode->path.parallel_aware = false;
3033 1360 : pathnode->path.parallel_safe = rel->consider_parallel &&
3034 412 : subpath->parallel_safe;
3035 948 : pathnode->path.parallel_workers = subpath->parallel_workers;
3036 948 : pathnode->subpath = subpath;
3037 :
3038 : /*
3039 : * Simplify callers by downgrading AGG_SORTED to AGG_PLAIN, and AGG_MIXED
3040 : * to AGG_HASHED, here if possible.
3041 : */
3042 1364 : if (aggstrategy == AGG_SORTED &&
3043 644 : list_length(rollups) == 1 &&
3044 228 : ((RollupData *) linitial(rollups))->groupClause == NIL)
3045 28 : aggstrategy = AGG_PLAIN;
3046 :
3047 1360 : if (aggstrategy == AGG_MIXED &&
3048 412 : list_length(rollups) == 1)
3049 0 : aggstrategy = AGG_HASHED;
3050 :
3051 : /*
3052 : * Output will be in sorted order by group_pathkeys if, and only if, there
3053 : * is a single rollup operation on a non-empty list of grouping
3054 : * expressions.
3055 : */
3056 948 : if (aggstrategy == AGG_SORTED && list_length(rollups) == 1)
3057 200 : pathnode->path.pathkeys = root->group_pathkeys;
3058 : else
3059 748 : pathnode->path.pathkeys = NIL;
3060 :
3061 948 : pathnode->aggstrategy = aggstrategy;
3062 948 : pathnode->rollups = rollups;
3063 948 : pathnode->qual = having_qual;
3064 :
3065 : Assert(rollups != NIL);
3066 : Assert(aggstrategy != AGG_PLAIN || list_length(rollups) == 1);
3067 : Assert(aggstrategy != AGG_MIXED || list_length(rollups) > 1);
3068 :
3069 3236 : foreach(lc, rollups)
3070 : {
3071 2288 : RollupData *rollup = lfirst(lc);
3072 2288 : List *gsets = rollup->gsets;
3073 2288 : int numGroupCols = list_length(linitial(gsets));
3074 :
3075 : /*
3076 : * In AGG_SORTED or AGG_PLAIN mode, the first rollup takes the
3077 : * (already-sorted) input, and following ones do their own sort.
3078 : *
3079 : * In AGG_HASHED mode, there is one rollup for each grouping set.
3080 : *
3081 : * In AGG_MIXED mode, the first rollups are hashed, the first
3082 : * non-hashed one takes the (already-sorted) input, and following ones
3083 : * do their own sort.
3084 : */
3085 2288 : if (is_first)
3086 : {
3087 948 : cost_agg(&pathnode->path, root,
3088 : aggstrategy,
3089 : agg_costs,
3090 : numGroupCols,
3091 : rollup->numGroups,
3092 : having_qual,
3093 : subpath->startup_cost,
3094 : subpath->total_cost,
3095 : subpath->rows);
3096 948 : is_first = false;
3097 948 : if (!rollup->is_hashed)
3098 416 : is_first_sort = false;
3099 : }
3100 : else
3101 : {
3102 : Path sort_path; /* dummy for result of cost_sort */
3103 : Path agg_path; /* dummy for result of cost_agg */
3104 :
3105 1340 : if (rollup->is_hashed || is_first_sort)
3106 : {
3107 : /*
3108 : * Account for cost of aggregation, but don't charge input
3109 : * cost again
3110 : */
3111 2000 : cost_agg(&agg_path, root,
3112 1000 : rollup->is_hashed ? AGG_HASHED : AGG_SORTED,
3113 : agg_costs,
3114 : numGroupCols,
3115 : rollup->numGroups,
3116 : having_qual,
3117 : 0.0, 0.0,
3118 : subpath->rows);
3119 2000 : if (!rollup->is_hashed)
3120 412 : is_first_sort = false;
3121 : }
3122 : else
3123 : {
3124 : /* Account for cost of sort, but don't charge input cost again */
3125 680 : cost_sort(&sort_path, root, NIL,
3126 : 0.0,
3127 : subpath->rows,
3128 340 : subpath->pathtarget->width,
3129 : 0.0,
3130 : work_mem,
3131 : -1.0);
3132 :
3133 : /* Account for cost of aggregation */
3134 :
3135 340 : cost_agg(&agg_path, root,
3136 : AGG_SORTED,
3137 : agg_costs,
3138 : numGroupCols,
3139 : rollup->numGroups,
3140 : having_qual,
3141 : sort_path.startup_cost,
3142 : sort_path.total_cost,
3143 : sort_path.rows);
3144 : }
3145 :
3146 1340 : pathnode->path.total_cost += agg_path.total_cost;
3147 1340 : pathnode->path.rows += agg_path.rows;
3148 : }
3149 : }
3150 :
3151 : /* add tlist eval cost for each output row */
3152 948 : pathnode->path.startup_cost += target->cost.startup;
3153 1896 : pathnode->path.total_cost += target->cost.startup +
3154 948 : target->cost.per_tuple * pathnode->path.rows;
3155 :
3156 948 : return pathnode;
3157 : }
3158 :
3159 : /*
3160 : * create_minmaxagg_path
3161 : * Creates a pathnode that represents computation of MIN/MAX aggregates
3162 : *
3163 : * 'rel' is the parent relation associated with the result
3164 : * 'target' is the PathTarget to be computed
3165 : * 'mmaggregates' is a list of MinMaxAggInfo structs
3166 : * 'quals' is the HAVING quals if any
3167 : */
3168 : MinMaxAggPath *
3169 398 : create_minmaxagg_path(PlannerInfo *root,
3170 : RelOptInfo *rel,
3171 : PathTarget *target,
3172 : List *mmaggregates,
3173 : List *quals)
3174 : {
3175 398 : MinMaxAggPath *pathnode = makeNode(MinMaxAggPath);
3176 : Cost initplan_cost;
3177 : ListCell *lc;
3178 :
3179 : /* The topmost generated Plan node will be a Result */
3180 398 : pathnode->path.pathtype = T_Result;
3181 398 : pathnode->path.parent = rel;
3182 398 : pathnode->path.pathtarget = target;
3183 : /* For now, assume we are above any joins, so no parameterization */
3184 398 : pathnode->path.param_info = NULL;
3185 398 : pathnode->path.parallel_aware = false;
3186 : /* A MinMaxAggPath implies use of subplans, so cannot be parallel-safe */
3187 398 : pathnode->path.parallel_safe = false;
3188 398 : pathnode->path.parallel_workers = 0;
3189 : /* Result is one unordered row */
3190 398 : pathnode->path.rows = 1;
3191 398 : pathnode->path.pathkeys = NIL;
3192 :
3193 398 : pathnode->mmaggregates = mmaggregates;
3194 398 : pathnode->quals = quals;
3195 :
3196 : /* Calculate cost of all the initplans ... */
3197 398 : initplan_cost = 0;
3198 820 : foreach(lc, mmaggregates)
3199 : {
3200 422 : MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc);
3201 :
3202 422 : initplan_cost += mminfo->pathcost;
3203 : }
3204 :
3205 : /* add tlist eval cost for each output row, plus cpu_tuple_cost */
3206 398 : pathnode->path.startup_cost = initplan_cost + target->cost.startup;
3207 1194 : pathnode->path.total_cost = initplan_cost + target->cost.startup +
3208 796 : target->cost.per_tuple + cpu_tuple_cost;
3209 :
3210 : /*
3211 : * Add cost of qual, if any --- but we ignore its selectivity, since our
3212 : * rowcount estimate should be 1 no matter what the qual is.
3213 : */
3214 398 : if (quals)
3215 : {
3216 : QualCost qual_cost;
3217 :
3218 0 : cost_qual_eval(&qual_cost, quals, root);
3219 0 : pathnode->path.startup_cost += qual_cost.startup;
3220 0 : pathnode->path.total_cost += qual_cost.startup + qual_cost.per_tuple;
3221 : }
3222 :
3223 398 : return pathnode;
3224 : }
3225 :
3226 : /*
3227 : * create_windowagg_path
3228 : * Creates a pathnode that represents computation of window functions
3229 : *
3230 : * 'rel' is the parent relation associated with the result
3231 : * 'subpath' is the path representing the source of data
3232 : * 'target' is the PathTarget to be computed
3233 : * 'windowFuncs' is a list of WindowFunc structs
3234 : * 'winclause' is a WindowClause that is common to all the WindowFuncs
3235 : *
3236 : * The input must be sorted according to the WindowClause's PARTITION keys
3237 : * plus ORDER BY keys.
3238 : */
3239 : WindowAggPath *
3240 1160 : create_windowagg_path(PlannerInfo *root,
3241 : RelOptInfo *rel,
3242 : Path *subpath,
3243 : PathTarget *target,
3244 : List *windowFuncs,
3245 : WindowClause *winclause)
3246 : {
3247 1160 : WindowAggPath *pathnode = makeNode(WindowAggPath);
3248 :
3249 1160 : pathnode->path.pathtype = T_WindowAgg;
3250 1160 : pathnode->path.parent = rel;
3251 1160 : pathnode->path.pathtarget = target;
3252 : /* For now, assume we are above any joins, so no parameterization */
3253 1160 : pathnode->path.param_info = NULL;
3254 1160 : pathnode->path.parallel_aware = false;
3255 1160 : pathnode->path.parallel_safe = rel->consider_parallel &&
3256 0 : subpath->parallel_safe;
3257 1160 : pathnode->path.parallel_workers = subpath->parallel_workers;
3258 : /* WindowAgg preserves the input sort order */
3259 1160 : pathnode->path.pathkeys = subpath->pathkeys;
3260 :
3261 1160 : pathnode->subpath = subpath;
3262 1160 : pathnode->winclause = winclause;
3263 :
3264 : /*
3265 : * For costing purposes, assume that there are no redundant partitioning
3266 : * or ordering columns; it's not worth the trouble to deal with that
3267 : * corner case here. So we just pass the unmodified list lengths to
3268 : * cost_windowagg.
3269 : */
3270 3480 : cost_windowagg(&pathnode->path, root,
3271 : windowFuncs,
3272 1160 : list_length(winclause->partitionClause),
3273 1160 : list_length(winclause->orderClause),
3274 : subpath->startup_cost,
3275 : subpath->total_cost,
3276 : subpath->rows);
3277 :
3278 : /* add tlist eval cost for each output row */
3279 1160 : pathnode->path.startup_cost += target->cost.startup;
3280 2320 : pathnode->path.total_cost += target->cost.startup +
3281 1160 : target->cost.per_tuple * pathnode->path.rows;
3282 :
3283 1160 : return pathnode;
3284 : }
3285 :
3286 : /*
3287 : * create_setop_path
3288 : * Creates a pathnode that represents computation of INTERSECT or EXCEPT
3289 : *
3290 : * 'rel' is the parent relation associated with the result
3291 : * 'subpath' is the path representing the source of data
3292 : * 'cmd' is the specific semantics (INTERSECT or EXCEPT, with/without ALL)
3293 : * 'strategy' is the implementation strategy (sorted or hashed)
3294 : * 'distinctList' is a list of SortGroupClause's representing the grouping
3295 : * 'flagColIdx' is the column number where the flag column will be, if any
3296 : * 'firstFlag' is the flag value for the first input relation when hashing;
3297 : * or -1 when sorting
3298 : * 'numGroups' is the estimated number of distinct groups
3299 : * 'outputRows' is the estimated number of output rows
3300 : */
3301 : SetOpPath *
3302 208 : create_setop_path(PlannerInfo *root,
3303 : RelOptInfo *rel,
3304 : Path *subpath,
3305 : SetOpCmd cmd,
3306 : SetOpStrategy strategy,
3307 : List *distinctList,
3308 : AttrNumber flagColIdx,
3309 : int firstFlag,
3310 : double numGroups,
3311 : double outputRows)
3312 : {
3313 208 : SetOpPath *pathnode = makeNode(SetOpPath);
3314 :
3315 208 : pathnode->path.pathtype = T_SetOp;
3316 208 : pathnode->path.parent = rel;
3317 : /* SetOp doesn't project, so use source path's pathtarget */
3318 208 : pathnode->path.pathtarget = subpath->pathtarget;
3319 : /* For now, assume we are above any joins, so no parameterization */
3320 208 : pathnode->path.param_info = NULL;
3321 208 : pathnode->path.parallel_aware = false;
3322 208 : pathnode->path.parallel_safe = rel->consider_parallel &&
3323 0 : subpath->parallel_safe;
3324 208 : pathnode->path.parallel_workers = subpath->parallel_workers;
3325 : /* SetOp preserves the input sort order if in sort mode */
3326 208 : pathnode->path.pathkeys =
3327 208 : (strategy == SETOP_SORTED) ? subpath->pathkeys : NIL;
3328 :
3329 208 : pathnode->subpath = subpath;
3330 208 : pathnode->cmd = cmd;
3331 208 : pathnode->strategy = strategy;
3332 208 : pathnode->distinctList = distinctList;
3333 208 : pathnode->flagColIdx = flagColIdx;
3334 208 : pathnode->firstFlag = firstFlag;
3335 208 : pathnode->numGroups = numGroups;
3336 :
3337 : /*
3338 : * Charge one cpu_operator_cost per comparison per input tuple. We assume
3339 : * all columns get compared at most of the tuples.
3340 : */
3341 208 : pathnode->path.startup_cost = subpath->startup_cost;
3342 416 : pathnode->path.total_cost = subpath->total_cost +
3343 208 : cpu_operator_cost * subpath->rows * list_length(distinctList);
3344 208 : pathnode->path.rows = outputRows;
3345 :
3346 208 : return pathnode;
3347 : }
3348 :
3349 : /*
3350 : * create_recursiveunion_path
3351 : * Creates a pathnode that represents a recursive UNION node
3352 : *
3353 : * 'rel' is the parent relation associated with the result
3354 : * 'leftpath' is the source of data for the non-recursive term
3355 : * 'rightpath' is the source of data for the recursive term
3356 : * 'target' is the PathTarget to be computed
3357 : * 'distinctList' is a list of SortGroupClause's representing the grouping
3358 : * 'wtParam' is the ID of Param representing work table
3359 : * 'numGroups' is the estimated number of groups
3360 : *
3361 : * For recursive UNION ALL, distinctList is empty and numGroups is zero
3362 : */
3363 : RecursiveUnionPath *
3364 326 : create_recursiveunion_path(PlannerInfo *root,
3365 : RelOptInfo *rel,
3366 : Path *leftpath,
3367 : Path *rightpath,
3368 : PathTarget *target,
3369 : List *distinctList,
3370 : int wtParam,
3371 : double numGroups)
3372 : {
3373 326 : RecursiveUnionPath *pathnode = makeNode(RecursiveUnionPath);
3374 :
3375 326 : pathnode->path.pathtype = T_RecursiveUnion;
3376 326 : pathnode->path.parent = rel;
3377 326 : pathnode->path.pathtarget = target;
3378 : /* For now, assume we are above any joins, so no parameterization */
3379 326 : pathnode->path.param_info = NULL;
3380 326 : pathnode->path.parallel_aware = false;
3381 652 : pathnode->path.parallel_safe = rel->consider_parallel &&
3382 326 : leftpath->parallel_safe && rightpath->parallel_safe;
3383 : /* Foolish, but we'll do it like joins for now: */
3384 326 : pathnode->path.parallel_workers = leftpath->parallel_workers;
3385 : /* RecursiveUnion result is always unsorted */
3386 326 : pathnode->path.pathkeys = NIL;
3387 :
3388 326 : pathnode->leftpath = leftpath;
3389 326 : pathnode->rightpath = rightpath;
3390 326 : pathnode->distinctList = distinctList;
3391 326 : pathnode->wtParam = wtParam;
3392 326 : pathnode->numGroups = numGroups;
3393 :
3394 326 : cost_recursive_union(&pathnode->path, leftpath, rightpath);
3395 :
3396 326 : return pathnode;
3397 : }
3398 :
3399 : /*
3400 : * create_lockrows_path
3401 : * Creates a pathnode that represents acquiring row locks
3402 : *
3403 : * 'rel' is the parent relation associated with the result
3404 : * 'subpath' is the path representing the source of data
3405 : * 'rowMarks' is a list of PlanRowMark's
3406 : * 'epqParam' is the ID of Param for EvalPlanQual re-eval
3407 : */
3408 : LockRowsPath *
3409 5260 : create_lockrows_path(PlannerInfo *root, RelOptInfo *rel,
3410 : Path *subpath, List *rowMarks, int epqParam)
3411 : {
3412 5260 : LockRowsPath *pathnode = makeNode(LockRowsPath);
3413 :
3414 5260 : pathnode->path.pathtype = T_LockRows;
3415 5260 : pathnode->path.parent = rel;
3416 : /* LockRows doesn't project, so use source path's pathtarget */
3417 5260 : pathnode->path.pathtarget = subpath->pathtarget;
3418 : /* For now, assume we are above any joins, so no parameterization */
3419 5260 : pathnode->path.param_info = NULL;
3420 5260 : pathnode->path.parallel_aware = false;
3421 5260 : pathnode->path.parallel_safe = false;
3422 5260 : pathnode->path.parallel_workers = 0;
3423 5260 : pathnode->path.rows = subpath->rows;
3424 :
3425 : /*
3426 : * The result cannot be assumed sorted, since locking might cause the sort
3427 : * key columns to be replaced with new values.
3428 : */
3429 5260 : pathnode->path.pathkeys = NIL;
3430 :
3431 5260 : pathnode->subpath = subpath;
3432 5260 : pathnode->rowMarks = rowMarks;
3433 5260 : pathnode->epqParam = epqParam;
3434 :
3435 : /*
3436 : * We should charge something extra for the costs of row locking and
3437 : * possible refetches, but it's hard to say how much. For now, use
3438 : * cpu_tuple_cost per row.
3439 : */
3440 5260 : pathnode->path.startup_cost = subpath->startup_cost;
3441 10520 : pathnode->path.total_cost = subpath->total_cost +
3442 5260 : cpu_tuple_cost * subpath->rows;
3443 :
3444 5260 : return pathnode;
3445 : }
3446 :
3447 : /*
3448 : * create_modifytable_path
3449 : * Creates a pathnode that represents performing INSERT/UPDATE/DELETE mods
3450 : *
3451 : * 'rel' is the parent relation associated with the result
3452 : * 'operation' is the operation type
3453 : * 'canSetTag' is true if we set the command tag/es_processed
3454 : * 'nominalRelation' is the parent RT index for use of EXPLAIN
3455 : * 'rootRelation' is the partitioned table root RT index, or 0 if none
3456 : * 'partColsUpdated' is true if any partitioning columns are being updated,
3457 : * either from the target relation or a descendent partitioned table.
3458 : * 'resultRelations' is an integer list of actual RT indexes of target rel(s)
3459 : * 'subpaths' is a list of Path(s) producing source data (one per rel)
3460 : * 'subroots' is a list of PlannerInfo structs (one per rel)
3461 : * 'withCheckOptionLists' is a list of WCO lists (one per rel)
3462 : * 'returningLists' is a list of RETURNING tlists (one per rel)
3463 : * 'rowMarks' is a list of PlanRowMarks (non-locking only)
3464 : * 'onconflict' is the ON CONFLICT clause, or NULL
3465 : * 'epqParam' is the ID of Param for EvalPlanQual re-eval
3466 : */
3467 : ModifyTablePath *
3468 72748 : create_modifytable_path(PlannerInfo *root, RelOptInfo *rel,
3469 : CmdType operation, bool canSetTag,
3470 : Index nominalRelation, Index rootRelation,
3471 : bool partColsUpdated,
3472 : List *resultRelations, List *subpaths,
3473 : List *subroots,
3474 : List *withCheckOptionLists, List *returningLists,
3475 : List *rowMarks, OnConflictExpr *onconflict,
3476 : int epqParam)
3477 : {
3478 72748 : ModifyTablePath *pathnode = makeNode(ModifyTablePath);
3479 : double total_size;
3480 : ListCell *lc;
3481 :
3482 : Assert(list_length(resultRelations) == list_length(subpaths));
3483 : Assert(list_length(resultRelations) == list_length(subroots));
3484 : Assert(withCheckOptionLists == NIL ||
3485 : list_length(resultRelations) == list_length(withCheckOptionLists));
3486 : Assert(returningLists == NIL ||
3487 : list_length(resultRelations) == list_length(returningLists));
3488 :
3489 72748 : pathnode->path.pathtype = T_ModifyTable;
3490 72748 : pathnode->path.parent = rel;
3491 : /* pathtarget is not interesting, just make it minimally valid */
3492 72748 : pathnode->path.pathtarget = rel->reltarget;
3493 : /* For now, assume we are above any joins, so no parameterization */
3494 72748 : pathnode->path.param_info = NULL;
3495 72748 : pathnode->path.parallel_aware = false;
3496 72748 : pathnode->path.parallel_safe = false;
3497 72748 : pathnode->path.parallel_workers = 0;
3498 72748 : pathnode->path.pathkeys = NIL;
3499 :
3500 : /*
3501 : * Compute cost & rowcount as sum of subpath costs & rowcounts.
3502 : *
3503 : * Currently, we don't charge anything extra for the actual table
3504 : * modification work, nor for the WITH CHECK OPTIONS or RETURNING
3505 : * expressions if any. It would only be window dressing, since
3506 : * ModifyTable is always a top-level node and there is no way for the
3507 : * costs to change any higher-level planning choices. But we might want
3508 : * to make it look better sometime.
3509 : */
3510 72748 : pathnode->path.startup_cost = 0;
3511 72748 : pathnode->path.total_cost = 0;
3512 72748 : pathnode->path.rows = 0;
3513 72748 : total_size = 0;
3514 146658 : foreach(lc, subpaths)
3515 : {
3516 73910 : Path *subpath = (Path *) lfirst(lc);
3517 :
3518 73910 : if (lc == list_head(subpaths)) /* first node? */
3519 72748 : pathnode->path.startup_cost = subpath->startup_cost;
3520 73910 : pathnode->path.total_cost += subpath->total_cost;
3521 73910 : pathnode->path.rows += subpath->rows;
3522 73910 : total_size += subpath->pathtarget->width * subpath->rows;
3523 : }
3524 :
3525 : /*
3526 : * Set width to the average width of the subpath outputs. XXX this is
3527 : * totally wrong: we should report zero if no RETURNING, else an average
3528 : * of the RETURNING tlist widths. But it's what happened historically,
3529 : * and improving it is a task for another day.
3530 : */
3531 72748 : if (pathnode->path.rows > 0)
3532 72680 : total_size /= pathnode->path.rows;
3533 72748 : pathnode->path.pathtarget->width = rint(total_size);
3534 :
3535 72748 : pathnode->operation = operation;
3536 72748 : pathnode->canSetTag = canSetTag;
3537 72748 : pathnode->nominalRelation = nominalRelation;
3538 72748 : pathnode->rootRelation = rootRelation;
3539 72748 : pathnode->partColsUpdated = partColsUpdated;
3540 72748 : pathnode->resultRelations = resultRelations;
3541 72748 : pathnode->subpaths = subpaths;
3542 72748 : pathnode->subroots = subroots;
3543 72748 : pathnode->withCheckOptionLists = withCheckOptionLists;
3544 72748 : pathnode->returningLists = returningLists;
3545 72748 : pathnode->rowMarks = rowMarks;
3546 72748 : pathnode->onconflict = onconflict;
3547 72748 : pathnode->epqParam = epqParam;
3548 :
3549 72748 : return pathnode;
3550 : }
3551 :
3552 : /*
3553 : * create_limit_path
3554 : * Creates a pathnode that represents performing LIMIT/OFFSET
3555 : *
3556 : * In addition to providing the actual OFFSET and LIMIT expressions,
3557 : * the caller must provide estimates of their values for costing purposes.
3558 : * The estimates are as computed by preprocess_limit(), ie, 0 represents
3559 : * the clause not being present, and -1 means it's present but we could
3560 : * not estimate its value.
3561 : *
3562 : * 'rel' is the parent relation associated with the result
3563 : * 'subpath' is the path representing the source of data
3564 : * 'limitOffset' is the actual OFFSET expression, or NULL
3565 : * 'limitCount' is the actual LIMIT expression, or NULL
3566 : * 'offset_est' is the estimated value of the OFFSET expression
3567 : * 'count_est' is the estimated value of the LIMIT expression
3568 : */
3569 : LimitPath *
3570 3370 : create_limit_path(PlannerInfo *root, RelOptInfo *rel,
3571 : Path *subpath,
3572 : Node *limitOffset, Node *limitCount,
3573 : int64 offset_est, int64 count_est)
3574 : {
3575 3370 : LimitPath *pathnode = makeNode(LimitPath);
3576 :
3577 3370 : pathnode->path.pathtype = T_Limit;
3578 3370 : pathnode->path.parent = rel;
3579 : /* Limit doesn't project, so use source path's pathtarget */
3580 3370 : pathnode->path.pathtarget = subpath->pathtarget;
3581 : /* For now, assume we are above any joins, so no parameterization */
3582 3370 : pathnode->path.param_info = NULL;
3583 3370 : pathnode->path.parallel_aware = false;
3584 4460 : pathnode->path.parallel_safe = rel->consider_parallel &&
3585 1090 : subpath->parallel_safe;
3586 3370 : pathnode->path.parallel_workers = subpath->parallel_workers;
3587 3370 : pathnode->path.rows = subpath->rows;
3588 3370 : pathnode->path.startup_cost = subpath->startup_cost;
3589 3370 : pathnode->path.total_cost = subpath->total_cost;
3590 3370 : pathnode->path.pathkeys = subpath->pathkeys;
3591 3370 : pathnode->subpath = subpath;
3592 3370 : pathnode->limitOffset = limitOffset;
3593 3370 : pathnode->limitCount = limitCount;
3594 :
3595 : /*
3596 : * Adjust the output rows count and costs according to the offset/limit.
3597 : */
3598 3370 : adjust_limit_rows_costs(&pathnode->path.rows,
3599 : &pathnode->path.startup_cost,
3600 : &pathnode->path.total_cost,
3601 : offset_est, count_est);
3602 :
3603 3370 : return pathnode;
3604 : }
3605 :
3606 : /*
3607 : * adjust_limit_rows_costs
3608 : * Adjust the size and cost estimates for a LimitPath node according to the
3609 : * offset/limit.
3610 : *
3611 : * This is only a cosmetic issue if we are at top level, but if we are
3612 : * building a subquery then it's important to report correct info to the outer
3613 : * planner.
3614 : *
3615 : * When the offset or count couldn't be estimated, use 10% of the estimated
3616 : * number of rows emitted from the subpath.
3617 : *
3618 : * XXX we don't bother to add eval costs of the offset/limit expressions
3619 : * themselves to the path costs. In theory we should, but in most cases those
3620 : * expressions are trivial and it's just not worth the trouble.
3621 : */
3622 : void
3623 3496 : adjust_limit_rows_costs(double *rows, /* in/out parameter */
3624 : Cost *startup_cost, /* in/out parameter */
3625 : Cost *total_cost, /* in/out parameter */
3626 : int64 offset_est,
3627 : int64 count_est)
3628 : {
3629 3496 : double input_rows = *rows;
3630 3496 : Cost input_startup_cost = *startup_cost;
3631 3496 : Cost input_total_cost = *total_cost;
3632 :
3633 3496 : if (offset_est != 0)
3634 : {
3635 : double offset_rows;
3636 :
3637 564 : if (offset_est > 0)
3638 548 : offset_rows = (double) offset_est;
3639 : else
3640 16 : offset_rows = clamp_row_est(input_rows * 0.10);
3641 564 : if (offset_rows > *rows)
3642 20 : offset_rows = *rows;
3643 564 : if (input_rows > 0)
3644 1128 : *startup_cost +=
3645 564 : (input_total_cost - input_startup_cost)
3646 564 : * offset_rows / input_rows;
3647 564 : *rows -= offset_rows;
3648 564 : if (*rows < 1)
3649 20 : *rows = 1;
3650 : }
3651 :
3652 3496 : if (count_est != 0)
3653 : {
3654 : double count_rows;
3655 :
3656 3480 : if (count_est > 0)
3657 3476 : count_rows = (double) count_est;
3658 : else
3659 4 : count_rows = clamp_row_est(input_rows * 0.10);
3660 3480 : if (count_rows > *rows)
3661 42 : count_rows = *rows;
3662 3480 : if (input_rows > 0)
3663 6960 : *total_cost = *startup_cost +
3664 3480 : (input_total_cost - input_startup_cost)
3665 3480 : * count_rows / input_rows;
3666 3480 : *rows = count_rows;
3667 3480 : if (*rows < 1)
3668 0 : *rows = 1;
3669 : }
3670 3496 : }
3671 :
3672 :
3673 : /*
3674 : * reparameterize_path
3675 : * Attempt to modify a Path to have greater parameterization
3676 : *
3677 : * We use this to attempt to bring all child paths of an appendrel to the
3678 : * same parameterization level, ensuring that they all enforce the same set
3679 : * of join quals (and thus that that parameterization can be attributed to
3680 : * an append path built from such paths). Currently, only a few path types
3681 : * are supported here, though more could be added at need. We return NULL
3682 : * if we can't reparameterize the given path.
3683 : *
3684 : * Note: we intentionally do not pass created paths to add_path(); it would
3685 : * possibly try to delete them on the grounds of being cost-inferior to the
3686 : * paths they were made from, and we don't want that. Paths made here are
3687 : * not necessarily of general-purpose usefulness, but they can be useful
3688 : * as members of an append path.
3689 : */
3690 : Path *
3691 188 : reparameterize_path(PlannerInfo *root, Path *path,
3692 : Relids required_outer,
3693 : double loop_count)
3694 : {
3695 188 : RelOptInfo *rel = path->parent;
3696 :
3697 : /* Can only increase, not decrease, path's parameterization */
3698 188 : if (!bms_is_subset(PATH_REQ_OUTER(path), required_outer))
3699 0 : return NULL;
3700 188 : switch (path->pathtype)
3701 : {
3702 : case T_SeqScan:
3703 124 : return create_seqscan_path(root, rel, required_outer, 0);
3704 : case T_SampleScan:
3705 0 : return (Path *) create_samplescan_path(root, rel, required_outer);
3706 : case T_IndexScan:
3707 : case T_IndexOnlyScan:
3708 : {
3709 0 : IndexPath *ipath = (IndexPath *) path;
3710 0 : IndexPath *newpath = makeNode(IndexPath);
3711 :
3712 : /*
3713 : * We can't use create_index_path directly, and would not want
3714 : * to because it would re-compute the indexqual conditions
3715 : * which is wasted effort. Instead we hack things a bit:
3716 : * flat-copy the path node, revise its param_info, and redo
3717 : * the cost estimate.
3718 : */
3719 0 : memcpy(newpath, ipath, sizeof(IndexPath));
3720 0 : newpath->path.param_info =
3721 0 : get_baserel_parampathinfo(root, rel, required_outer);
3722 0 : cost_index(newpath, root, loop_count, false);
3723 0 : return (Path *) newpath;
3724 : }
3725 : case T_BitmapHeapScan:
3726 : {
3727 0 : BitmapHeapPath *bpath = (BitmapHeapPath *) path;
3728 :
3729 0 : return (Path *) create_bitmap_heap_path(root,
3730 : rel,
3731 : bpath->bitmapqual,
3732 : required_outer,
3733 : loop_count, 0);
3734 : }
3735 : case T_SubqueryScan:
3736 : {
3737 0 : SubqueryScanPath *spath = (SubqueryScanPath *) path;
3738 :
3739 0 : return (Path *) create_subqueryscan_path(root,
3740 : rel,
3741 : spath->subpath,
3742 : spath->path.pathkeys,
3743 : required_outer);
3744 : }
3745 : case T_Result:
3746 : /* Supported only for RTE_RESULT scan paths */
3747 32 : if (IsA(path, Path))
3748 32 : return create_resultscan_path(root, rel, required_outer);
3749 0 : break;
3750 : case T_Append:
3751 : {
3752 0 : AppendPath *apath = (AppendPath *) path;
3753 0 : List *childpaths = NIL;
3754 0 : List *partialpaths = NIL;
3755 : int i;
3756 : ListCell *lc;
3757 :
3758 : /* Reparameterize the children */
3759 0 : i = 0;
3760 0 : foreach(lc, apath->subpaths)
3761 : {
3762 0 : Path *spath = (Path *) lfirst(lc);
3763 :
3764 0 : spath = reparameterize_path(root, spath,
3765 : required_outer,
3766 : loop_count);
3767 0 : if (spath == NULL)
3768 0 : return NULL;
3769 : /* We have to re-split the regular and partial paths */
3770 0 : if (i < apath->first_partial_path)
3771 0 : childpaths = lappend(childpaths, spath);
3772 : else
3773 0 : partialpaths = lappend(partialpaths, spath);
3774 0 : i++;
3775 : }
3776 0 : return (Path *)
3777 0 : create_append_path(root, rel, childpaths, partialpaths,
3778 : apath->path.pathkeys, required_outer,
3779 : apath->path.parallel_workers,
3780 0 : apath->path.parallel_aware,
3781 : apath->partitioned_rels,
3782 : -1);
3783 : }
3784 : default:
3785 32 : break;
3786 : }
3787 32 : return NULL;
3788 : }
3789 :
3790 : /*
3791 : * reparameterize_path_by_child
3792 : * Given a path parameterized by the parent of the given child relation,
3793 : * translate the path to be parameterized by the given child relation.
3794 : *
3795 : * The function creates a new path of the same type as the given path, but
3796 : * parameterized by the given child relation. Most fields from the original
3797 : * path can simply be flat-copied, but any expressions must be adjusted to
3798 : * refer to the correct varnos, and any paths must be recursively
3799 : * reparameterized. Other fields that refer to specific relids also need
3800 : * adjustment.
3801 : *
3802 : * The cost, number of rows, width and parallel path properties depend upon
3803 : * path->parent, which does not change during the translation. Hence those
3804 : * members are copied as they are.
3805 : *
3806 : * If the given path can not be reparameterized, the function returns NULL.
3807 : */
3808 : Path *
3809 2164 : reparameterize_path_by_child(PlannerInfo *root, Path *path,
3810 : RelOptInfo *child_rel)
3811 : {
3812 :
3813 : #define FLAT_COPY_PATH(newnode, node, nodetype) \
3814 : ( (newnode) = makeNode(nodetype), \
3815 : memcpy((newnode), (node), sizeof(nodetype)) )
3816 :
3817 : #define ADJUST_CHILD_ATTRS(node) \
3818 : ((node) = \
3819 : (List *) adjust_appendrel_attrs_multilevel(root, (Node *) (node), \
3820 : child_rel->relids, \
3821 : child_rel->top_parent_relids))
3822 :
3823 : #define REPARAMETERIZE_CHILD_PATH(path) \
3824 : do { \
3825 : (path) = reparameterize_path_by_child(root, (path), child_rel); \
3826 : if ((path) == NULL) \
3827 : return NULL; \
3828 : } while(0);
3829 :
3830 : #define REPARAMETERIZE_CHILD_PATH_LIST(pathlist) \
3831 : do { \
3832 : if ((pathlist) != NIL) \
3833 : { \
3834 : (pathlist) = reparameterize_pathlist_by_child(root, (pathlist), \
3835 : child_rel); \
3836 : if ((pathlist) == NIL) \
3837 : return NULL; \
3838 : } \
3839 : } while(0);
3840 :
3841 : Path *new_path;
3842 : ParamPathInfo *new_ppi;
3843 : ParamPathInfo *old_ppi;
3844 : Relids required_outer;
3845 :
3846 : /*
3847 : * If the path is not parameterized by parent of the given relation, it
3848 : * doesn't need reparameterization.
3849 : */
3850 4304 : if (!path->param_info ||
3851 2140 : !bms_overlap(PATH_REQ_OUTER(path), child_rel->top_parent_relids))
3852 128 : return path;
3853 :
3854 : /* Reparameterize a copy of given path. */
3855 2036 : switch (nodeTag(path))
3856 : {
3857 : case T_Path:
3858 288 : FLAT_COPY_PATH(new_path, path, Path);
3859 288 : break;
3860 :
3861 : case T_IndexPath:
3862 : {
3863 : IndexPath *ipath;
3864 :
3865 1280 : FLAT_COPY_PATH(ipath, path, IndexPath);
3866 1280 : ADJUST_CHILD_ATTRS(ipath->indexclauses);
3867 1280 : new_path = (Path *) ipath;
3868 : }
3869 1280 : break;
3870 :
3871 : case T_BitmapHeapPath:
3872 : {
3873 : BitmapHeapPath *bhpath;
3874 :
3875 0 : FLAT_COPY_PATH(bhpath, path, BitmapHeapPath);
3876 0 : REPARAMETERIZE_CHILD_PATH(bhpath->bitmapqual);
3877 0 : new_path = (Path *) bhpath;
3878 : }
3879 0 : break;
3880 :
3881 : case T_BitmapAndPath:
3882 : {
3883 : BitmapAndPath *bapath;
3884 :
3885 0 : FLAT_COPY_PATH(bapath, path, BitmapAndPath);
3886 0 : REPARAMETERIZE_CHILD_PATH_LIST(bapath->bitmapquals);
3887 0 : new_path = (Path *) bapath;
3888 : }
3889 0 : break;
3890 :
3891 : case T_BitmapOrPath:
3892 : {
3893 : BitmapOrPath *bopath;
3894 :
3895 0 : FLAT_COPY_PATH(bopath, path, BitmapOrPath);
3896 0 : REPARAMETERIZE_CHILD_PATH_LIST(bopath->bitmapquals);
3897 0 : new_path = (Path *) bopath;
3898 : }
3899 0 : break;
3900 :
3901 : case T_TidPath:
3902 : {
3903 : TidPath *tpath;
3904 :
3905 0 : FLAT_COPY_PATH(tpath, path, TidPath);
3906 0 : ADJUST_CHILD_ATTRS(tpath->tidquals);
3907 0 : new_path = (Path *) tpath;
3908 : }
3909 0 : break;
3910 :
3911 : case T_ForeignPath:
3912 : {
3913 : ForeignPath *fpath;
3914 : ReparameterizeForeignPathByChild_function rfpc_func;
3915 :
3916 52 : FLAT_COPY_PATH(fpath, path, ForeignPath);
3917 52 : if (fpath->fdw_outerpath)
3918 0 : REPARAMETERIZE_CHILD_PATH(fpath->fdw_outerpath);
3919 :
3920 : /* Hand over to FDW if needed. */
3921 52 : rfpc_func =
3922 52 : path->parent->fdwroutine->ReparameterizeForeignPathByChild;
3923 52 : if (rfpc_func)
3924 0 : fpath->fdw_private = rfpc_func(root, fpath->fdw_private,
3925 : child_rel);
3926 52 : new_path = (Path *) fpath;
3927 : }
3928 52 : break;
3929 :
3930 : case T_CustomPath:
3931 : {
3932 : CustomPath *cpath;
3933 :
3934 0 : FLAT_COPY_PATH(cpath, path, CustomPath);
3935 0 : REPARAMETERIZE_CHILD_PATH_LIST(cpath->custom_paths);
3936 0 : if (cpath->methods &&
3937 0 : cpath->methods->ReparameterizeCustomPathByChild)
3938 0 : cpath->custom_private =
3939 0 : cpath->methods->ReparameterizeCustomPathByChild(root,
3940 : cpath->custom_private,
3941 : child_rel);
3942 0 : new_path = (Path *) cpath;
3943 : }
3944 0 : break;
3945 :
3946 : case T_NestPath:
3947 : {
3948 : JoinPath *jpath;
3949 :
3950 200 : FLAT_COPY_PATH(jpath, path, NestPath);
3951 :
3952 200 : REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath);
3953 200 : REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath);
3954 200 : ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo);
3955 200 : new_path = (Path *) jpath;
3956 : }
3957 200 : break;
3958 :
3959 : case T_MergePath:
3960 : {
3961 : JoinPath *jpath;
3962 : MergePath *mpath;
3963 :
3964 24 : FLAT_COPY_PATH(mpath, path, MergePath);
3965 :
3966 24 : jpath = (JoinPath *) mpath;
3967 24 : REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath);
3968 24 : REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath);
3969 24 : ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo);
3970 24 : ADJUST_CHILD_ATTRS(mpath->path_mergeclauses);
3971 24 : new_path = (Path *) mpath;
3972 : }
3973 24 : break;
3974 :
3975 : case T_HashPath:
3976 : {
3977 : JoinPath *jpath;
3978 : HashPath *hpath;
3979 :
3980 112 : FLAT_COPY_PATH(hpath, path, HashPath);
3981 :
3982 112 : jpath = (JoinPath *) hpath;
3983 112 : REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath);
3984 112 : REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath);
3985 112 : ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo);
3986 112 : ADJUST_CHILD_ATTRS(hpath->path_hashclauses);
3987 112 : new_path = (Path *) hpath;
3988 : }
3989 112 : break;
3990 :
3991 : case T_AppendPath:
3992 : {
3993 : AppendPath *apath;
3994 :
3995 80 : FLAT_COPY_PATH(apath, path, AppendPath);
3996 80 : REPARAMETERIZE_CHILD_PATH_LIST(apath->subpaths);
3997 80 : new_path = (Path *) apath;
3998 : }
3999 80 : break;
4000 :
4001 : case T_MergeAppendPath:
4002 : {
4003 : MergeAppendPath *mapath;
4004 :
4005 0 : FLAT_COPY_PATH(mapath, path, MergeAppendPath);
4006 0 : REPARAMETERIZE_CHILD_PATH_LIST(mapath->subpaths);
4007 0 : new_path = (Path *) mapath;
4008 : }
4009 0 : break;
4010 :
4011 : case T_MaterialPath:
4012 : {
4013 : MaterialPath *mpath;
4014 :
4015 0 : FLAT_COPY_PATH(mpath, path, MaterialPath);
4016 0 : REPARAMETERIZE_CHILD_PATH(mpath->subpath);
4017 0 : new_path = (Path *) mpath;
4018 : }
4019 0 : break;
4020 :
4021 : case T_UniquePath:
4022 : {
4023 : UniquePath *upath;
4024 :
4025 0 : FLAT_COPY_PATH(upath, path, UniquePath);
4026 0 : REPARAMETERIZE_CHILD_PATH(upath->subpath);
4027 0 : ADJUST_CHILD_ATTRS(upath->uniq_exprs);
4028 0 : new_path = (Path *) upath;
4029 : }
4030 0 : break;
4031 :
4032 : case T_GatherPath:
4033 : {
4034 : GatherPath *gpath;
4035 :
4036 0 : FLAT_COPY_PATH(gpath, path, GatherPath);
4037 0 : REPARAMETERIZE_CHILD_PATH(gpath->subpath);
4038 0 : new_path = (Path *) gpath;
4039 : }
4040 0 : break;
4041 :
4042 : case T_GatherMergePath:
4043 : {
4044 : GatherMergePath *gmpath;
4045 :
4046 0 : FLAT_COPY_PATH(gmpath, path, GatherMergePath);
4047 0 : REPARAMETERIZE_CHILD_PATH(gmpath->subpath);
4048 0 : new_path = (Path *) gmpath;
4049 : }
4050 0 : break;
4051 :
4052 : default:
4053 :
4054 : /* We don't know how to reparameterize this path. */
4055 0 : return NULL;
4056 : }
4057 :
4058 : /*
4059 : * Adjust the parameterization information, which refers to the topmost
4060 : * parent. The topmost parent can be multiple levels away from the given
4061 : * child, hence use multi-level expression adjustment routines.
4062 : */
4063 2036 : old_ppi = new_path->param_info;
4064 2036 : required_outer =
4065 2036 : adjust_child_relids_multilevel(root, old_ppi->ppi_req_outer,
4066 : child_rel->relids,
4067 : child_rel->top_parent_relids);
4068 :
4069 : /* If we already have a PPI for this parameterization, just return it */
4070 2036 : new_ppi = find_param_path_info(new_path->parent, required_outer);
4071 :
4072 : /*
4073 : * If not, build a new one and link it to the list of PPIs. For the same
4074 : * reason as explained in mark_dummy_rel(), allocate new PPI in the same
4075 : * context the given RelOptInfo is in.
4076 : */
4077 2036 : if (new_ppi == NULL)
4078 : {
4079 : MemoryContext oldcontext;
4080 956 : RelOptInfo *rel = path->parent;
4081 :
4082 956 : oldcontext = MemoryContextSwitchTo(GetMemoryChunkContext(rel));
4083 :
4084 956 : new_ppi = makeNode(ParamPathInfo);
4085 956 : new_ppi->ppi_req_outer = bms_copy(required_outer);
4086 956 : new_ppi->ppi_rows = old_ppi->ppi_rows;
4087 956 : new_ppi->ppi_clauses = old_ppi->ppi_clauses;
4088 956 : ADJUST_CHILD_ATTRS(new_ppi->ppi_clauses);
4089 956 : rel->ppilist = lappend(rel->ppilist, new_ppi);
4090 :
4091 956 : MemoryContextSwitchTo(oldcontext);
4092 : }
4093 2036 : bms_free(required_outer);
4094 :
4095 2036 : new_path->param_info = new_ppi;
4096 :
4097 : /*
4098 : * Adjust the path target if the parent of the outer relation is
4099 : * referenced in the targetlist. This can happen when only the parent of
4100 : * outer relation is laterally referenced in this relation.
4101 : */
4102 2036 : if (bms_overlap(path->parent->lateral_relids,
4103 2036 : child_rel->top_parent_relids))
4104 : {
4105 768 : new_path->pathtarget = copy_pathtarget(new_path->pathtarget);
4106 768 : ADJUST_CHILD_ATTRS(new_path->pathtarget->exprs);
4107 : }
4108 :
4109 2036 : return new_path;
4110 : }
4111 :
4112 : /*
4113 : * reparameterize_pathlist_by_child
4114 : * Helper function to reparameterize a list of paths by given child rel.
4115 : */
4116 : static List *
4117 80 : reparameterize_pathlist_by_child(PlannerInfo *root,
4118 : List *pathlist,
4119 : RelOptInfo *child_rel)
4120 : {
4121 : ListCell *lc;
4122 80 : List *result = NIL;
4123 :
4124 240 : foreach(lc, pathlist)
4125 : {
4126 160 : Path *path = reparameterize_path_by_child(root, lfirst(lc),
4127 : child_rel);
4128 :
4129 160 : if (path == NULL)
4130 : {
4131 0 : list_free(result);
4132 0 : return NIL;
4133 : }
4134 :
4135 160 : result = lappend(result, path);
4136 : }
4137 :
4138 80 : return result;
4139 : }
|
