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allpaths.c
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1/*-------------------------------------------------------------------------
2 *
3 * allpaths.c
4 * Routines to find possible search paths for processing a query
5 *
6 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/optimizer/path/allpaths.c
12 *
13 *-------------------------------------------------------------------------
14 */
15
16#include "postgres.h"
17
18#include <limits.h>
19#include <math.h>
20
21#include "access/sysattr.h"
22#include "access/tsmapi.h"
23#include "catalog/pg_class.h"
24#include "catalog/pg_operator.h"
25#include "catalog/pg_proc.h"
26#include "foreign/fdwapi.h"
27#include "miscadmin.h"
28#include "nodes/makefuncs.h"
29#include "nodes/nodeFuncs.h"
30#include "nodes/supportnodes.h"
31#ifdef OPTIMIZER_DEBUG
32#include "nodes/print.h"
33#endif
34#include "optimizer/appendinfo.h"
35#include "optimizer/clauses.h"
36#include "optimizer/cost.h"
37#include "optimizer/geqo.h"
38#include "optimizer/optimizer.h"
39#include "optimizer/pathnode.h"
40#include "optimizer/paths.h"
41#include "optimizer/plancat.h"
42#include "optimizer/planner.h"
43#include "optimizer/tlist.h"
44#include "parser/parse_clause.h"
45#include "parser/parsetree.h"
46#include "partitioning/partbounds.h"
47#include "port/pg_bitutils.h"
48#include "rewrite/rewriteManip.h"
49#include "utils/lsyscache.h"
50
51
52/* Bitmask flags for pushdown_safety_info.unsafeFlags */
53#define UNSAFE_HAS_VOLATILE_FUNC (1 << 0)
54#define UNSAFE_HAS_SET_FUNC (1 << 1)
55#define UNSAFE_NOTIN_DISTINCTON_CLAUSE (1 << 2)
56#define UNSAFE_NOTIN_PARTITIONBY_CLAUSE (1 << 3)
57#define UNSAFE_TYPE_MISMATCH (1 << 4)
58
59/* results of subquery_is_pushdown_safe */
60typedef struct pushdown_safety_info
61{
62 unsigned char *unsafeFlags; /* bitmask of reasons why this target list
63 * column is unsafe for qual pushdown, or 0 if
64 * no reason. */
65 bool unsafeVolatile; /* don't push down volatile quals */
66 bool unsafeLeaky; /* don't push down leaky quals */
67} pushdown_safety_info;
68
69/* Return type for qual_is_pushdown_safe */
70typedef enum pushdown_safe_type
71{
72 PUSHDOWN_UNSAFE, /* unsafe to push qual into subquery */
73 PUSHDOWN_SAFE, /* safe to push qual into subquery */
74 PUSHDOWN_WINDOWCLAUSE_RUNCOND, /* unsafe, but may work as WindowClause
75 * run condition */
76} pushdown_safe_type;
77
78/* These parameters are set by GUC */
79bool enable_geqo = false; /* just in case GUC doesn't set it */
80int geqo_threshold;
81int min_parallel_table_scan_size;
82int min_parallel_index_scan_size;
83
84/* Hook for plugins to get control in set_rel_pathlist() */
85set_rel_pathlist_hook_type set_rel_pathlist_hook = NULL;
86
87/* Hook for plugins to replace standard_join_search() */
88join_search_hook_type join_search_hook = NULL;
89
90
91static void set_base_rel_consider_startup(PlannerInfo *root);
92static void set_base_rel_sizes(PlannerInfo *root);
93static void set_base_rel_pathlists(PlannerInfo *root);
94static void set_rel_size(PlannerInfo *root, RelOptInfo *rel,
95 Index rti, RangeTblEntry *rte);
96static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
97 Index rti, RangeTblEntry *rte);
98static void set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel,
99 RangeTblEntry *rte);
100static void create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel);
101static void set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
102 RangeTblEntry *rte);
103static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
104 RangeTblEntry *rte);
105static void set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel,
106 RangeTblEntry *rte);
107static void set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
108 RangeTblEntry *rte);
109static void set_foreign_size(PlannerInfo *root, RelOptInfo *rel,
110 RangeTblEntry *rte);
111static void set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel,
112 RangeTblEntry *rte);
113static void set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
114 Index rti, RangeTblEntry *rte);
115static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
116 Index rti, RangeTblEntry *rte);
117static void generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel,
118 List *live_childrels,
119 List *all_child_pathkeys);
120static Path *get_cheapest_parameterized_child_path(PlannerInfo *root,
121 RelOptInfo *rel,
122 Relids required_outer);
123static void accumulate_append_subpath(Path *path,
124 List **subpaths,
125 List **special_subpaths);
126static Path *get_singleton_append_subpath(Path *path);
127static void set_dummy_rel_pathlist(RelOptInfo *rel);
128static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel,
129 Index rti, RangeTblEntry *rte);
130static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel,
131 RangeTblEntry *rte);
132static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel,
133 RangeTblEntry *rte);
134static void set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel,
135 RangeTblEntry *rte);
136static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel,
137 RangeTblEntry *rte);
138static void set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel,
139 RangeTblEntry *rte);
140static void set_result_pathlist(PlannerInfo *root, RelOptInfo *rel,
141 RangeTblEntry *rte);
142static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel,
143 RangeTblEntry *rte);
144static RelOptInfo *make_rel_from_joinlist(PlannerInfo *root, List *joinlist);
145static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery,
146 pushdown_safety_info *safetyInfo);
147static bool recurse_pushdown_safe(Node *setOp, Query *topquery,
148 pushdown_safety_info *safetyInfo);
149static void check_output_expressions(Query *subquery,
150 pushdown_safety_info *safetyInfo);
151static void compare_tlist_datatypes(List *tlist, List *colTypes,
152 pushdown_safety_info *safetyInfo);
153static bool targetIsInAllPartitionLists(TargetEntry *tle, Query *query);
154static pushdown_safe_type qual_is_pushdown_safe(Query *subquery, Index rti,
155 RestrictInfo *rinfo,
156 pushdown_safety_info *safetyInfo);
157static void subquery_push_qual(Query *subquery,
158 RangeTblEntry *rte, Index rti, Node *qual);
159static void recurse_push_qual(Node *setOp, Query *topquery,
160 RangeTblEntry *rte, Index rti, Node *qual);
161static void remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel,
162 Bitmapset *extra_used_attrs);
163
164
165/*
166 * make_one_rel
167 * Finds all possible access paths for executing a query, returning a
168 * single rel that represents the join of all base rels in the query.
169 */
170RelOptInfo *
171make_one_rel(PlannerInfo *root, List *joinlist)
172{
173 RelOptInfo *rel;
174 Index rti;
175 double total_pages;
176
177 /* Mark base rels as to whether we care about fast-start plans */
178 set_base_rel_consider_startup(root);
179
180 /*
181 * Compute size estimates and consider_parallel flags for each base rel.
182 */
183 set_base_rel_sizes(root);
184
185 /*
186 * We should now have size estimates for every actual table involved in
187 * the query, and we also know which if any have been deleted from the
188 * query by join removal, pruned by partition pruning, or eliminated by
189 * constraint exclusion. So we can now compute total_table_pages.
190 *
191 * Note that appendrels are not double-counted here, even though we don't
192 * bother to distinguish RelOptInfos for appendrel parents, because the
193 * parents will have pages = 0.
194 *
195 * XXX if a table is self-joined, we will count it once per appearance,
196 * which perhaps is the wrong thing ... but that's not completely clear,
197 * and detecting self-joins here is difficult, so ignore it for now.
198 */
199 total_pages = 0;
200 for (rti = 1; rti < root->simple_rel_array_size; rti++)
201 {
202 RelOptInfo *brel = root->simple_rel_array[rti];
203
204 /* there may be empty slots corresponding to non-baserel RTEs */
205 if (brel == NULL)
206 continue;
207
208 Assert(brel->relid == rti); /* sanity check on array */
209
210 if (IS_DUMMY_REL(brel))
211 continue;
212
213 if (IS_SIMPLE_REL(brel))
214 total_pages += (double) brel->pages;
215 }
216 root->total_table_pages = total_pages;
217
218 /*
219 * Generate access paths for each base rel.
220 */
221 set_base_rel_pathlists(root);
222
223 /*
224 * Generate access paths for the entire join tree.
225 */
226 rel = make_rel_from_joinlist(root, joinlist);
227
228 /*
229 * The result should join all and only the query's base + outer-join rels.
230 */
231 Assert(bms_equal(rel->relids, root->all_query_rels));
232
233 return rel;
234}
235
236/*
237 * set_base_rel_consider_startup
238 * Set the consider_[param_]startup flags for each base-relation entry.
239 *
240 * For the moment, we only deal with consider_param_startup here; because the
241 * logic for consider_startup is pretty trivial and is the same for every base
242 * relation, we just let build_simple_rel() initialize that flag correctly to
243 * start with. If that logic ever gets more complicated it would probably
244 * be better to move it here.
245 */
246static void
247set_base_rel_consider_startup(PlannerInfo *root)
248{
249 /*
250 * Since parameterized paths can only be used on the inside of a nestloop
251 * join plan, there is usually little value in considering fast-start
252 * plans for them. However, for relations that are on the RHS of a SEMI
253 * or ANTI join, a fast-start plan can be useful because we're only going
254 * to care about fetching one tuple anyway.
255 *
256 * To minimize growth of planning time, we currently restrict this to
257 * cases where the RHS is a single base relation, not a join; there is no
258 * provision for consider_param_startup to get set at all on joinrels.
259 * Also we don't worry about appendrels. costsize.c's costing rules for
260 * nestloop semi/antijoins don't consider such cases either.
261 */
262 ListCell *lc;
263
264 foreach(lc, root->join_info_list)
265 {
266 SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
267 int varno;
268
269 if ((sjinfo->jointype == JOIN_SEMI || sjinfo->jointype == JOIN_ANTI) &&
270 bms_get_singleton_member(sjinfo->syn_righthand, &varno))
271 {
272 RelOptInfo *rel = find_base_rel(root, varno);
273
274 rel->consider_param_startup = true;
275 }
276 }
277}
278
279/*
280 * set_base_rel_sizes
281 * Set the size estimates (rows and widths) for each base-relation entry.
282 * Also determine whether to consider parallel paths for base relations.
283 *
284 * We do this in a separate pass over the base rels so that rowcount
285 * estimates are available for parameterized path generation, and also so
286 * that each rel's consider_parallel flag is set correctly before we begin to
287 * generate paths.
288 */
289static void
290set_base_rel_sizes(PlannerInfo *root)
291{
292 Index rti;
293
294 for (rti = 1; rti < root->simple_rel_array_size; rti++)
295 {
296 RelOptInfo *rel = root->simple_rel_array[rti];
297 RangeTblEntry *rte;
298
299 /* there may be empty slots corresponding to non-baserel RTEs */
300 if (rel == NULL)
301 continue;
302
303 Assert(rel->relid == rti); /* sanity check on array */
304
305 /* ignore RTEs that are "other rels" */
306 if (rel->reloptkind != RELOPT_BASEREL)
307 continue;
308
309 rte = root->simple_rte_array[rti];
310
311 /*
312 * If parallelism is allowable for this query in general, see whether
313 * it's allowable for this rel in particular. We have to do this
314 * before set_rel_size(), because (a) if this rel is an inheritance
315 * parent, set_append_rel_size() will use and perhaps change the rel's
316 * consider_parallel flag, and (b) for some RTE types, set_rel_size()
317 * goes ahead and makes paths immediately.
318 */
319 if (root->glob->parallelModeOK)
320 set_rel_consider_parallel(root, rel, rte);
321
322 set_rel_size(root, rel, rti, rte);
323 }
324}
325
326/*
327 * set_base_rel_pathlists
328 * Finds all paths available for scanning each base-relation entry.
329 * Sequential scan and any available indices are considered.
330 * Each useful path is attached to its relation's 'pathlist' field.
331 */
332static void
333set_base_rel_pathlists(PlannerInfo *root)
334{
335 Index rti;
336
337 for (rti = 1; rti < root->simple_rel_array_size; rti++)
338 {
339 RelOptInfo *rel = root->simple_rel_array[rti];
340
341 /* there may be empty slots corresponding to non-baserel RTEs */
342 if (rel == NULL)
343 continue;
344
345 Assert(rel->relid == rti); /* sanity check on array */
346
347 /* ignore RTEs that are "other rels" */
348 if (rel->reloptkind != RELOPT_BASEREL)
349 continue;
350
351 set_rel_pathlist(root, rel, rti, root->simple_rte_array[rti]);
352 }
353}
354
355/*
356 * set_rel_size
357 * Set size estimates for a base relation
358 */
359static void
360set_rel_size(PlannerInfo *root, RelOptInfo *rel,
361 Index rti, RangeTblEntry *rte)
362{
363 if (rel->reloptkind == RELOPT_BASEREL &&
364 relation_excluded_by_constraints(root, rel, rte))
365 {
366 /*
367 * We proved we don't need to scan the rel via constraint exclusion,
368 * so set up a single dummy path for it. Here we only check this for
369 * regular baserels; if it's an otherrel, CE was already checked in
370 * set_append_rel_size().
371 *
372 * In this case, we go ahead and set up the relation's path right away
373 * instead of leaving it for set_rel_pathlist to do. This is because
374 * we don't have a convention for marking a rel as dummy except by
375 * assigning a dummy path to it.
376 */
377 set_dummy_rel_pathlist(rel);
378 }
379 else if (rte->inh)
380 {
381 /* It's an "append relation", process accordingly */
382 set_append_rel_size(root, rel, rti, rte);
383 }
384 else
385 {
386 switch (rel->rtekind)
387 {
388 case RTE_RELATION:
389 if (rte->relkind == RELKIND_FOREIGN_TABLE)
390 {
391 /* Foreign table */
392 set_foreign_size(root, rel, rte);
393 }
394 else if (rte->relkind == RELKIND_PARTITIONED_TABLE)
395 {
396 /*
397 * We could get here if asked to scan a partitioned table
398 * with ONLY. In that case we shouldn't scan any of the
399 * partitions, so mark it as a dummy rel.
400 */
401 set_dummy_rel_pathlist(rel);
402 }
403 else if (rte->tablesample != NULL)
404 {
405 /* Sampled relation */
406 set_tablesample_rel_size(root, rel, rte);
407 }
408 else
409 {
410 /* Plain relation */
411 set_plain_rel_size(root, rel, rte);
412 }
413 break;
414 case RTE_SUBQUERY:
415
416 /*
417 * Subqueries don't support making a choice between
418 * parameterized and unparameterized paths, so just go ahead
419 * and build their paths immediately.
420 */
421 set_subquery_pathlist(root, rel, rti, rte);
422 break;
423 case RTE_FUNCTION:
424 set_function_size_estimates(root, rel);
425 break;
426 case RTE_TABLEFUNC:
427 set_tablefunc_size_estimates(root, rel);
428 break;
429 case RTE_VALUES:
430 set_values_size_estimates(root, rel);
431 break;
432 case RTE_CTE:
433
434 /*
435 * CTEs don't support making a choice between parameterized
436 * and unparameterized paths, so just go ahead and build their
437 * paths immediately.
438 */
439 if (rte->self_reference)
440 set_worktable_pathlist(root, rel, rte);
441 else
442 set_cte_pathlist(root, rel, rte);
443 break;
444 case RTE_NAMEDTUPLESTORE:
445 /* Might as well just build the path immediately */
446 set_namedtuplestore_pathlist(root, rel, rte);
447 break;
448 case RTE_RESULT:
449 /* Might as well just build the path immediately */
450 set_result_pathlist(root, rel, rte);
451 break;
452 default:
453 elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
454 break;
455 }
456 }
457
458 /*
459 * We insist that all non-dummy rels have a nonzero rowcount estimate.
460 */
461 Assert(rel->rows > 0 || IS_DUMMY_REL(rel));
462}
463
464/*
465 * set_rel_pathlist
466 * Build access paths for a base relation
467 */
468static void
469set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
470 Index rti, RangeTblEntry *rte)
471{
472 if (IS_DUMMY_REL(rel))
473 {
474 /* We already proved the relation empty, so nothing more to do */
475 }
476 else if (rte->inh)
477 {
478 /* It's an "append relation", process accordingly */
479 set_append_rel_pathlist(root, rel, rti, rte);
480 }
481 else
482 {
483 switch (rel->rtekind)
484 {
485 case RTE_RELATION:
486 if (rte->relkind == RELKIND_FOREIGN_TABLE)
487 {
488 /* Foreign table */
489 set_foreign_pathlist(root, rel, rte);
490 }
491 else if (rte->tablesample != NULL)
492 {
493 /* Sampled relation */
494 set_tablesample_rel_pathlist(root, rel, rte);
495 }
496 else
497 {
498 /* Plain relation */
499 set_plain_rel_pathlist(root, rel, rte);
500 }
501 break;
502 case RTE_SUBQUERY:
503 /* Subquery --- fully handled during set_rel_size */
504 break;
505 case RTE_FUNCTION:
506 /* RangeFunction */
507 set_function_pathlist(root, rel, rte);
508 break;
509 case RTE_TABLEFUNC:
510 /* Table Function */
511 set_tablefunc_pathlist(root, rel, rte);
512 break;
513 case RTE_VALUES:
514 /* Values list */
515 set_values_pathlist(root, rel, rte);
516 break;
517 case RTE_CTE:
518 /* CTE reference --- fully handled during set_rel_size */
519 break;
520 case RTE_NAMEDTUPLESTORE:
521 /* tuplestore reference --- fully handled during set_rel_size */
522 break;
523 case RTE_RESULT:
524 /* simple Result --- fully handled during set_rel_size */
525 break;
526 default:
527 elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
528 break;
529 }
530 }
531
532 /*
533 * Allow a plugin to editorialize on the set of Paths for this base
534 * relation. It could add new paths (such as CustomPaths) by calling
535 * add_path(), or add_partial_path() if parallel aware. It could also
536 * delete or modify paths added by the core code.
537 */
538 if (set_rel_pathlist_hook)
539 (*set_rel_pathlist_hook) (root, rel, rti, rte);
540
541 /*
542 * If this is a baserel, we should normally consider gathering any partial
543 * paths we may have created for it. We have to do this after calling the
544 * set_rel_pathlist_hook, else it cannot add partial paths to be included
545 * here.
546 *
547 * However, if this is an inheritance child, skip it. Otherwise, we could
548 * end up with a very large number of gather nodes, each trying to grab
549 * its own pool of workers. Instead, we'll consider gathering partial
550 * paths for the parent appendrel.
551 *
552 * Also, if this is the topmost scan/join rel, we postpone gathering until
553 * the final scan/join targetlist is available (see grouping_planner).
554 */
555 if (rel->reloptkind == RELOPT_BASEREL &&
556 !bms_equal(rel->relids, root->all_query_rels))
557 generate_useful_gather_paths(root, rel, false);
558
559 /* Now find the cheapest of the paths for this rel */
560 set_cheapest(rel);
561
562#ifdef OPTIMIZER_DEBUG
563 pprint(rel);
564#endif
565}
566
567/*
568 * set_plain_rel_size
569 * Set size estimates for a plain relation (no subquery, no inheritance)
570 */
571static void
572set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
573{
574 /*
575 * Test any partial indexes of rel for applicability. We must do this
576 * first since partial unique indexes can affect size estimates.
577 */
578 check_index_predicates(root, rel);
579
580 /* Mark rel with estimated output rows, width, etc */
581 set_baserel_size_estimates(root, rel);
582}
583
584/*
585 * If this relation could possibly be scanned from within a worker, then set
586 * its consider_parallel flag.
587 */
588static void
589set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
590 RangeTblEntry *rte)
591{
592 /*
593 * The flag has previously been initialized to false, so we can just
594 * return if it becomes clear that we can't safely set it.
595 */
596 Assert(!rel->consider_parallel);
597
598 /* Don't call this if parallelism is disallowed for the entire query. */
599 Assert(root->glob->parallelModeOK);
600
601 /* This should only be called for baserels and appendrel children. */
602 Assert(IS_SIMPLE_REL(rel));
603
604 /* Assorted checks based on rtekind. */
605 switch (rte->rtekind)
606 {
607 case RTE_RELATION:
608
609 /*
610 * Currently, parallel workers can't access the leader's temporary
611 * tables. We could possibly relax this if we wrote all of its
612 * local buffers at the start of the query and made no changes
613 * thereafter (maybe we could allow hint bit changes), and if we
614 * taught the workers to read them. Writing a large number of
615 * temporary buffers could be expensive, though, and we don't have
616 * the rest of the necessary infrastructure right now anyway. So
617 * for now, bail out if we see a temporary table.
618 */
619 if (get_rel_persistence(rte->relid) == RELPERSISTENCE_TEMP)
620 return;
621
622 /*
623 * Table sampling can be pushed down to workers if the sample
624 * function and its arguments are safe.
625 */
626 if (rte->tablesample != NULL)
627 {
628 char proparallel = func_parallel(rte->tablesample->tsmhandler);
629
630 if (proparallel != PROPARALLEL_SAFE)
631 return;
632 if (!is_parallel_safe(root, (Node *) rte->tablesample->args))
633 return;
634 }
635
636 /*
637 * Ask FDWs whether they can support performing a ForeignScan
638 * within a worker. Most often, the answer will be no. For
639 * example, if the nature of the FDW is such that it opens a TCP
640 * connection with a remote server, each parallel worker would end
641 * up with a separate connection, and these connections might not
642 * be appropriately coordinated between workers and the leader.
643 */
644 if (rte->relkind == RELKIND_FOREIGN_TABLE)
645 {
646 Assert(rel->fdwroutine);
647 if (!rel->fdwroutine->IsForeignScanParallelSafe)
648 return;
649 if (!rel->fdwroutine->IsForeignScanParallelSafe(root, rel, rte))
650 return;
651 }
652
653 /*
654 * There are additional considerations for appendrels, which we'll
655 * deal with in set_append_rel_size and set_append_rel_pathlist.
656 * For now, just set consider_parallel based on the rel's own
657 * quals and targetlist.
658 */
659 break;
660
661 case RTE_SUBQUERY:
662
663 /*
664 * There's no intrinsic problem with scanning a subquery-in-FROM
665 * (as distinct from a SubPlan or InitPlan) in a parallel worker.
666 * If the subquery doesn't happen to have any parallel-safe paths,
667 * then flagging it as consider_parallel won't change anything,
668 * but that's true for plain tables, too. We must set
669 * consider_parallel based on the rel's own quals and targetlist,
670 * so that if a subquery path is parallel-safe but the quals and
671 * projection we're sticking onto it are not, we correctly mark
672 * the SubqueryScanPath as not parallel-safe. (Note that
673 * set_subquery_pathlist() might push some of these quals down
674 * into the subquery itself, but that doesn't change anything.)
675 *
676 * We can't push sub-select containing LIMIT/OFFSET to workers as
677 * there is no guarantee that the row order will be fully
678 * deterministic, and applying LIMIT/OFFSET will lead to
679 * inconsistent results at the top-level. (In some cases, where
680 * the result is ordered, we could relax this restriction. But it
681 * doesn't currently seem worth expending extra effort to do so.)
682 */
683 {
684 Query *subquery = castNode(Query, rte->subquery);
685
686 if (limit_needed(subquery))
687 return;
688 }
689 break;
690
691 case RTE_JOIN:
692 /* Shouldn't happen; we're only considering baserels here. */
693 Assert(false);
694 return;
695
696 case RTE_FUNCTION:
697 /* Check for parallel-restricted functions. */
698 if (!is_parallel_safe(root, (Node *) rte->functions))
699 return;
700 break;
701
702 case RTE_TABLEFUNC:
703 /* not parallel safe */
704 return;
705
706 case RTE_VALUES:
707 /* Check for parallel-restricted functions. */
708 if (!is_parallel_safe(root, (Node *) rte->values_lists))
709 return;
710 break;
711
712 case RTE_CTE:
713
714 /*
715 * CTE tuplestores aren't shared among parallel workers, so we
716 * force all CTE scans to happen in the leader. Also, populating
717 * the CTE would require executing a subplan that's not available
718 * in the worker, might be parallel-restricted, and must get
719 * executed only once.
720 */
721 return;
722
723 case RTE_NAMEDTUPLESTORE:
724
725 /*
726 * tuplestore cannot be shared, at least without more
727 * infrastructure to support that.
728 */
729 return;
730
731 case RTE_RESULT:
732 /* RESULT RTEs, in themselves, are no problem. */
733 break;
734 case RTE_GROUP:
735 /* Shouldn't happen; we're only considering baserels here. */
736 Assert(false);
737 return;
738 }
739
740 /*
741 * If there's anything in baserestrictinfo that's parallel-restricted, we
742 * give up on parallelizing access to this relation. We could consider
743 * instead postponing application of the restricted quals until we're
744 * above all the parallelism in the plan tree, but it's not clear that
745 * that would be a win in very many cases, and it might be tricky to make
746 * outer join clauses work correctly. It would likely break equivalence
747 * classes, too.
748 */
749 if (!is_parallel_safe(root, (Node *) rel->baserestrictinfo))
750 return;
751
752 /*
753 * Likewise, if the relation's outputs are not parallel-safe, give up.
754 * (Usually, they're just Vars, but sometimes they're not.)
755 */
756 if (!is_parallel_safe(root, (Node *) rel->reltarget->exprs))
757 return;
758
759 /* We have a winner. */
760 rel->consider_parallel = true;
761}
762
763/*
764 * set_plain_rel_pathlist
765 * Build access paths for a plain relation (no subquery, no inheritance)
766 */
767static void
768set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
769{
770 Relids required_outer;
771
772 /*
773 * We don't support pushing join clauses into the quals of a seqscan, but
774 * it could still have required parameterization due to LATERAL refs in
775 * its tlist.
776 */
777 required_outer = rel->lateral_relids;
778
779 /*
780 * Consider TID scans.
781 *
782 * If create_tidscan_paths returns true, then a TID scan path is forced.
783 * This happens when rel->baserestrictinfo contains CurrentOfExpr, because
784 * the executor can't handle any other type of path for such queries.
785 * Hence, we return without adding any other paths.
786 */
787 if (create_tidscan_paths(root, rel))
788 return;
789
790 /* Consider sequential scan */
791 add_path(rel, create_seqscan_path(root, rel, required_outer, 0));
792
793 /* If appropriate, consider parallel sequential scan */
794 if (rel->consider_parallel && required_outer == NULL)
795 create_plain_partial_paths(root, rel);
796
797 /* Consider index scans */
798 create_index_paths(root, rel);
799}
800
801/*
802 * create_plain_partial_paths
803 * Build partial access paths for parallel scan of a plain relation
804 */
805static void
806create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel)
807{
808 int parallel_workers;
809
810 parallel_workers = compute_parallel_worker(rel, rel->pages, -1,
811 max_parallel_workers_per_gather);
812
813 /* If any limit was set to zero, the user doesn't want a parallel scan. */
814 if (parallel_workers <= 0)
815 return;
816
817 /* Add an unordered partial path based on a parallel sequential scan. */
818 add_partial_path(rel, create_seqscan_path(root, rel, NULL, parallel_workers));
819}
820
821/*
822 * set_tablesample_rel_size
823 * Set size estimates for a sampled relation
824 */
825static void
826set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
827{
828 TableSampleClause *tsc = rte->tablesample;
829 TsmRoutine *tsm;
830 BlockNumber pages;
831 double tuples;
832
833 /*
834 * Test any partial indexes of rel for applicability. We must do this
835 * first since partial unique indexes can affect size estimates.
836 */
837 check_index_predicates(root, rel);
838
839 /*
840 * Call the sampling method's estimation function to estimate the number
841 * of pages it will read and the number of tuples it will return. (Note:
842 * we assume the function returns sane values.)
843 */
844 tsm = GetTsmRoutine(tsc->tsmhandler);
845 tsm->SampleScanGetSampleSize(root, rel, tsc->args,
846 &pages, &tuples);
847
848 /*
849 * For the moment, because we will only consider a SampleScan path for the
850 * rel, it's okay to just overwrite the pages and tuples estimates for the
851 * whole relation. If we ever consider multiple path types for sampled
852 * rels, we'll need more complication.
853 */
854 rel->pages = pages;
855 rel->tuples = tuples;
856
857 /* Mark rel with estimated output rows, width, etc */
858 set_baserel_size_estimates(root, rel);
859}
860
861/*
862 * set_tablesample_rel_pathlist
863 * Build access paths for a sampled relation
864 */
865static void
866set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
867{
868 Relids required_outer;
869 Path *path;
870
871 /*
872 * We don't support pushing join clauses into the quals of a samplescan,
873 * but it could still have required parameterization due to LATERAL refs
874 * in its tlist or TABLESAMPLE arguments.
875 */
876 required_outer = rel->lateral_relids;
877
878 /* Consider sampled scan */
879 path = create_samplescan_path(root, rel, required_outer);
880
881 /*
882 * If the sampling method does not support repeatable scans, we must avoid
883 * plans that would scan the rel multiple times. Ideally, we'd simply
884 * avoid putting the rel on the inside of a nestloop join; but adding such
885 * a consideration to the planner seems like a great deal of complication
886 * to support an uncommon usage of second-rate sampling methods. Instead,
887 * if there is a risk that the query might perform an unsafe join, just
888 * wrap the SampleScan in a Materialize node. We can check for joins by
889 * counting the membership of all_query_rels (note that this correctly
890 * counts inheritance trees as single rels). If we're inside a subquery,
891 * we can't easily check whether a join might occur in the outer query, so
892 * just assume one is possible.
893 *
894 * GetTsmRoutine is relatively expensive compared to the other tests here,
895 * so check repeatable_across_scans last, even though that's a bit odd.
896 */
897 if ((root->query_level > 1 ||
898 bms_membership(root->all_query_rels) != BMS_SINGLETON) &&
899 !(GetTsmRoutine(rte->tablesample->tsmhandler)->repeatable_across_scans))
900 {
901 path = (Path *) create_material_path(rel, path);
902 }
903
904 add_path(rel, path);
905
906 /* For the moment, at least, there are no other paths to consider */
907}
908
909/*
910 * set_foreign_size
911 * Set size estimates for a foreign table RTE
912 */
913static void
914set_foreign_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
915{
916 /* Mark rel with estimated output rows, width, etc */
917 set_foreign_size_estimates(root, rel);
918
919 /* Let FDW adjust the size estimates, if it can */
920 rel->fdwroutine->GetForeignRelSize(root, rel, rte->relid);
921
922 /* ... but do not let it set the rows estimate to zero */
923 rel->rows = clamp_row_est(rel->rows);
924
925 /*
926 * Also, make sure rel->tuples is not insane relative to rel->rows.
927 * Notably, this ensures sanity if pg_class.reltuples contains -1 and the
928 * FDW doesn't do anything to replace that.
929 */
930 rel->tuples = Max(rel->tuples, rel->rows);
931}
932
933/*
934 * set_foreign_pathlist
935 * Build access paths for a foreign table RTE
936 */
937static void
938set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
939{
940 /* Call the FDW's GetForeignPaths function to generate path(s) */
941 rel->fdwroutine->GetForeignPaths(root, rel, rte->relid);
942}
943
944/*
945 * set_append_rel_size
946 * Set size estimates for a simple "append relation"
947 *
948 * The passed-in rel and RTE represent the entire append relation. The
949 * relation's contents are computed by appending together the output of the
950 * individual member relations. Note that in the non-partitioned inheritance
951 * case, the first member relation is actually the same table as is mentioned
952 * in the parent RTE ... but it has a different RTE and RelOptInfo. This is
953 * a good thing because their outputs are not the same size.
954 */
955static void
956set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
957 Index rti, RangeTblEntry *rte)
958{
959 int parentRTindex = rti;
960 bool has_live_children;
961 double parent_tuples;
962 double parent_rows;
963 double parent_size;
964 double *parent_attrsizes;
965 int nattrs;
966 ListCell *l;
967
968 /* Guard against stack overflow due to overly deep inheritance tree. */
969 check_stack_depth();
970
971 Assert(IS_SIMPLE_REL(rel));
972
973 /*
974 * If this is a partitioned baserel, set the consider_partitionwise_join
975 * flag; currently, we only consider partitionwise joins with the baserel
976 * if its targetlist doesn't contain a whole-row Var.
977 */
978 if (enable_partitionwise_join &&
979 rel->reloptkind == RELOPT_BASEREL &&
980 rte->relkind == RELKIND_PARTITIONED_TABLE &&
981 bms_is_empty(rel->attr_needed[InvalidAttrNumber - rel->min_attr]))
982 rel->consider_partitionwise_join = true;
983
984 /*
985 * Initialize to compute size estimates for whole append relation.
986 *
987 * We handle tuples estimates by setting "tuples" to the total number of
988 * tuples accumulated from each live child, rather than using "rows".
989 * Although an appendrel itself doesn't directly enforce any quals, its
990 * child relations may. Therefore, setting "tuples" equal to "rows" for
991 * an appendrel isn't always appropriate, and can lead to inaccurate cost
992 * estimates. For example, when estimating the number of distinct values
993 * from an appendrel, we would be unable to adjust the estimate based on
994 * the restriction selectivity (see estimate_num_groups).
995 *
996 * We handle width estimates by weighting the widths of different child
997 * rels proportionally to their number of rows. This is sensible because
998 * the use of width estimates is mainly to compute the total relation
999 * "footprint" if we have to sort or hash it. To do this, we sum the
1000 * total equivalent size (in "double" arithmetic) and then divide by the
1001 * total rowcount estimate. This is done separately for the total rel
1002 * width and each attribute.
1003 *
1004 * Note: if you consider changing this logic, beware that child rels could
1005 * have zero rows and/or width, if they were excluded by constraints.
1006 */
1007 has_live_children = false;
1008 parent_tuples = 0;
1009 parent_rows = 0;
1010 parent_size = 0;
1011 nattrs = rel->max_attr - rel->min_attr + 1;
1012 parent_attrsizes = (double *) palloc0(nattrs * sizeof(double));
1013
1014 foreach(l, root->append_rel_list)
1015 {
1016 AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
1017 int childRTindex;
1018 RangeTblEntry *childRTE;
1019 RelOptInfo *childrel;
1020 List *childrinfos;
1021 ListCell *parentvars;
1022 ListCell *childvars;
1023 ListCell *lc;
1024
1025 /* append_rel_list contains all append rels; ignore others */
1026 if (appinfo->parent_relid != parentRTindex)
1027 continue;
1028
1029 childRTindex = appinfo->child_relid;
1030 childRTE = root->simple_rte_array[childRTindex];
1031
1032 /*
1033 * The child rel's RelOptInfo was already created during
1034 * add_other_rels_to_query.
1035 */
1036 childrel = find_base_rel(root, childRTindex);
1037 Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
1038
1039 /* We may have already proven the child to be dummy. */
1040 if (IS_DUMMY_REL(childrel))
1041 continue;
1042
1043 /*
1044 * We have to copy the parent's targetlist and quals to the child,
1045 * with appropriate substitution of variables. However, the
1046 * baserestrictinfo quals were already copied/substituted when the
1047 * child RelOptInfo was built. So we don't need any additional setup
1048 * before applying constraint exclusion.
1049 */
1050 if (relation_excluded_by_constraints(root, childrel, childRTE))
1051 {
1052 /*
1053 * This child need not be scanned, so we can omit it from the
1054 * appendrel.
1055 */
1056 set_dummy_rel_pathlist(childrel);
1057 continue;
1058 }
1059
1060 /*
1061 * Constraint exclusion failed, so copy the parent's join quals and
1062 * targetlist to the child, with appropriate variable substitutions.
1063 *
1064 * We skip join quals that came from above outer joins that can null
1065 * this rel, since they would be of no value while generating paths
1066 * for the child. This saves some effort while processing the child
1067 * rel, and it also avoids an implementation restriction in
1068 * adjust_appendrel_attrs (it can't apply nullingrels to a non-Var).
1069 */
1070 childrinfos = NIL;
1071 foreach(lc, rel->joininfo)
1072 {
1073 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
1074
1075 if (!bms_overlap(rinfo->clause_relids, rel->nulling_relids))
1076 childrinfos = lappend(childrinfos,
1077 adjust_appendrel_attrs(root,
1078 (Node *) rinfo,
1079 1, &appinfo));
1080 }
1081 childrel->joininfo = childrinfos;
1082
1083 /*
1084 * Now for the child's targetlist.
1085 *
1086 * NB: the resulting childrel->reltarget->exprs may contain arbitrary
1087 * expressions, which otherwise would not occur in a rel's targetlist.
1088 * Code that might be looking at an appendrel child must cope with
1089 * such. (Normally, a rel's targetlist would only include Vars and
1090 * PlaceHolderVars.) XXX we do not bother to update the cost or width
1091 * fields of childrel->reltarget; not clear if that would be useful.
1092 */
1093 childrel->reltarget->exprs = (List *)
1094 adjust_appendrel_attrs(root,
1095 (Node *) rel->reltarget->exprs,
1096 1, &appinfo);
1097
1098 /*
1099 * We have to make child entries in the EquivalenceClass data
1100 * structures as well. This is needed either if the parent
1101 * participates in some eclass joins (because we will want to consider
1102 * inner-indexscan joins on the individual children) or if the parent
1103 * has useful pathkeys (because we should try to build MergeAppend
1104 * paths that produce those sort orderings).
1105 */
1106 if (rel->has_eclass_joins || has_useful_pathkeys(root, rel))
1107 add_child_rel_equivalences(root, appinfo, rel, childrel);
1108 childrel->has_eclass_joins = rel->has_eclass_joins;
1109
1110 /*
1111 * Note: we could compute appropriate attr_needed data for the child's
1112 * variables, by transforming the parent's attr_needed through the
1113 * translated_vars mapping. However, currently there's no need
1114 * because attr_needed is only examined for base relations not
1115 * otherrels. So we just leave the child's attr_needed empty.
1116 */
1117
1118 /*
1119 * If we consider partitionwise joins with the parent rel, do the same
1120 * for partitioned child rels.
1121 *
1122 * Note: here we abuse the consider_partitionwise_join flag by setting
1123 * it for child rels that are not themselves partitioned. We do so to
1124 * tell try_partitionwise_join() that the child rel is sufficiently
1125 * valid to be used as a per-partition input, even if it later gets
1126 * proven to be dummy. (It's not usable until we've set up the
1127 * reltarget and EC entries, which we just did.)
1128 */
1129 if (rel->consider_partitionwise_join)
1130 childrel->consider_partitionwise_join = true;
1131
1132 /*
1133 * If parallelism is allowable for this query in general, see whether
1134 * it's allowable for this childrel in particular. But if we've
1135 * already decided the appendrel is not parallel-safe as a whole,
1136 * there's no point in considering parallelism for this child. For
1137 * consistency, do this before calling set_rel_size() for the child.
1138 */
1139 if (root->glob->parallelModeOK && rel->consider_parallel)
1140 set_rel_consider_parallel(root, childrel, childRTE);
1141
1142 /*
1143 * Compute the child's size.
1144 */
1145 set_rel_size(root, childrel, childRTindex, childRTE);
1146
1147 /*
1148 * It is possible that constraint exclusion detected a contradiction
1149 * within a child subquery, even though we didn't prove one above. If
1150 * so, we can skip this child.
1151 */
1152 if (IS_DUMMY_REL(childrel))
1153 continue;
1154
1155 /* We have at least one live child. */
1156 has_live_children = true;
1157
1158 /*
1159 * If any live child is not parallel-safe, treat the whole appendrel
1160 * as not parallel-safe. In future we might be able to generate plans
1161 * in which some children are farmed out to workers while others are
1162 * not; but we don't have that today, so it's a waste to consider
1163 * partial paths anywhere in the appendrel unless it's all safe.
1164 * (Child rels visited before this one will be unmarked in
1165 * set_append_rel_pathlist().)
1166 */
1167 if (!childrel->consider_parallel)
1168 rel->consider_parallel = false;
1169
1170 /*
1171 * Accumulate size information from each live child.
1172 */
1173 Assert(childrel->rows > 0);
1174
1175 parent_tuples += childrel->tuples;
1176 parent_rows += childrel->rows;
1177 parent_size += childrel->reltarget->width * childrel->rows;
1178
1179 /*
1180 * Accumulate per-column estimates too. We need not do anything for
1181 * PlaceHolderVars in the parent list. If child expression isn't a
1182 * Var, or we didn't record a width estimate for it, we have to fall
1183 * back on a datatype-based estimate.
1184 *
1185 * By construction, child's targetlist is 1-to-1 with parent's.
1186 */
1187 forboth(parentvars, rel->reltarget->exprs,
1188 childvars, childrel->reltarget->exprs)
1189 {
1190 Var *parentvar = (Var *) lfirst(parentvars);
1191 Node *childvar = (Node *) lfirst(childvars);
1192
1193 if (IsA(parentvar, Var) && parentvar->varno == parentRTindex)
1194 {
1195 int pndx = parentvar->varattno - rel->min_attr;
1196 int32 child_width = 0;
1197
1198 if (IsA(childvar, Var) &&
1199 ((Var *) childvar)->varno == childrel->relid)
1200 {
1201 int cndx = ((Var *) childvar)->varattno - childrel->min_attr;
1202
1203 child_width = childrel->attr_widths[cndx];
1204 }
1205 if (child_width <= 0)
1206 child_width = get_typavgwidth(exprType(childvar),
1207 exprTypmod(childvar));
1208 Assert(child_width > 0);
1209 parent_attrsizes[pndx] += child_width * childrel->rows;
1210 }
1211 }
1212 }
1213
1214 if (has_live_children)
1215 {
1216 /*
1217 * Save the finished size estimates.
1218 */
1219 int i;
1220
1221 Assert(parent_rows > 0);
1222 rel->tuples = parent_tuples;
1223 rel->rows = parent_rows;
1224 rel->reltarget->width = rint(parent_size / parent_rows);
1225 for (i = 0; i < nattrs; i++)
1226 rel->attr_widths[i] = rint(parent_attrsizes[i] / parent_rows);
1227
1228 /*
1229 * Note that we leave rel->pages as zero; this is important to avoid
1230 * double-counting the appendrel tree in total_table_pages.
1231 */
1232 }
1233 else
1234 {
1235 /*
1236 * All children were excluded by constraints, so mark the whole
1237 * appendrel dummy. We must do this in this phase so that the rel's
1238 * dummy-ness is visible when we generate paths for other rels.
1239 */
1240 set_dummy_rel_pathlist(rel);
1241 }
1242
1243 pfree(parent_attrsizes);
1244}
1245
1246/*
1247 * set_append_rel_pathlist
1248 * Build access paths for an "append relation"
1249 */
1250static void
1251set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
1252 Index rti, RangeTblEntry *rte)
1253{
1254 int parentRTindex = rti;
1255 List *live_childrels = NIL;
1256 ListCell *l;
1257
1258 /*
1259 * Generate access paths for each member relation, and remember the
1260 * non-dummy children.
1261 */
1262 foreach(l, root->append_rel_list)
1263 {
1264 AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
1265 int childRTindex;
1266 RangeTblEntry *childRTE;
1267 RelOptInfo *childrel;
1268
1269 /* append_rel_list contains all append rels; ignore others */
1270 if (appinfo->parent_relid != parentRTindex)
1271 continue;
1272
1273 /* Re-locate the child RTE and RelOptInfo */
1274 childRTindex = appinfo->child_relid;
1275 childRTE = root->simple_rte_array[childRTindex];
1276 childrel = root->simple_rel_array[childRTindex];
1277
1278 /*
1279 * If set_append_rel_size() decided the parent appendrel was
1280 * parallel-unsafe at some point after visiting this child rel, we
1281 * need to propagate the unsafety marking down to the child, so that
1282 * we don't generate useless partial paths for it.
1283 */
1284 if (!rel->consider_parallel)
1285 childrel->consider_parallel = false;
1286
1287 /*
1288 * Compute the child's access paths.
1289 */
1290 set_rel_pathlist(root, childrel, childRTindex, childRTE);
1291
1292 /*
1293 * If child is dummy, ignore it.
1294 */
1295 if (IS_DUMMY_REL(childrel))
1296 continue;
1297
1298 /*
1299 * Child is live, so add it to the live_childrels list for use below.
1300 */
1301 live_childrels = lappend(live_childrels, childrel);
1302 }
1303
1304 /* Add paths to the append relation. */
1305 add_paths_to_append_rel(root, rel, live_childrels);
1306}
1307
1308
1309/*
1310 * add_paths_to_append_rel
1311 * Generate paths for the given append relation given the set of non-dummy
1312 * child rels.
1313 *
1314 * The function collects all parameterizations and orderings supported by the
1315 * non-dummy children. For every such parameterization or ordering, it creates
1316 * an append path collecting one path from each non-dummy child with given
1317 * parameterization or ordering. Similarly it collects partial paths from
1318 * non-dummy children to create partial append paths.
1319 */
1320void
1321add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
1322 List *live_childrels)
1323{
1324 List *subpaths = NIL;
1325 bool subpaths_valid = true;
1326 List *startup_subpaths = NIL;
1327 bool startup_subpaths_valid = true;
1328 List *partial_subpaths = NIL;
1329 List *pa_partial_subpaths = NIL;
1330 List *pa_nonpartial_subpaths = NIL;
1331 bool partial_subpaths_valid = true;
1332 bool pa_subpaths_valid;
1333 List *all_child_pathkeys = NIL;
1334 List *all_child_outers = NIL;
1335 ListCell *l;
1336 double partial_rows = -1;
1337
1338 /* If appropriate, consider parallel append */
1339 pa_subpaths_valid = enable_parallel_append && rel->consider_parallel;
1340
1341 /*
1342 * For every non-dummy child, remember the cheapest path. Also, identify
1343 * all pathkeys (orderings) and parameterizations (required_outer sets)
1344 * available for the non-dummy member relations.
1345 */
1346 foreach(l, live_childrels)
1347 {
1348 RelOptInfo *childrel = lfirst(l);
1349 ListCell *lcp;
1350 Path *cheapest_partial_path = NULL;
1351
1352 /*
1353 * If child has an unparameterized cheapest-total path, add that to
1354 * the unparameterized Append path we are constructing for the parent.
1355 * If not, there's no workable unparameterized path.
1356 *
1357 * With partitionwise aggregates, the child rel's pathlist may be
1358 * empty, so don't assume that a path exists here.
1359 */
1360 if (childrel->pathlist != NIL &&
1361 childrel->cheapest_total_path->param_info == NULL)
1362 accumulate_append_subpath(childrel->cheapest_total_path,
1363 &subpaths, NULL);
1364 else
1365 subpaths_valid = false;
1366
1367 /*
1368 * When the planner is considering cheap startup plans, we'll also
1369 * collect all the cheapest_startup_paths (if set) and build an
1370 * AppendPath containing those as subpaths.
1371 */
1372 if (rel->consider_startup && childrel->cheapest_startup_path != NULL)
1373 {
1374 Path *cheapest_path;
1375
1376 /*
1377 * With an indication of how many tuples the query should provide,
1378 * the optimizer tries to choose the path optimal for that
1379 * specific number of tuples.
1380 */
1381 if (root->tuple_fraction > 0.0)
1382 cheapest_path =
1383 get_cheapest_fractional_path(childrel,
1384 root->tuple_fraction);
1385 else
1386 cheapest_path = childrel->cheapest_startup_path;
1387
1388 /* cheapest_startup_path must not be a parameterized path. */
1389 Assert(cheapest_path->param_info == NULL);
1390 accumulate_append_subpath(cheapest_path,
1391 &startup_subpaths,
1392 NULL);
1393 }
1394 else
1395 startup_subpaths_valid = false;
1396
1397
1398 /* Same idea, but for a partial plan. */
1399 if (childrel->partial_pathlist != NIL)
1400 {
1401 cheapest_partial_path = linitial(childrel->partial_pathlist);
1402 accumulate_append_subpath(cheapest_partial_path,
1403 &partial_subpaths, NULL);
1404 }
1405 else
1406 partial_subpaths_valid = false;
1407
1408 /*
1409 * Same idea, but for a parallel append mixing partial and non-partial
1410 * paths.
1411 */
1412 if (pa_subpaths_valid)
1413 {
1414 Path *nppath = NULL;
1415
1416 nppath =
1417 get_cheapest_parallel_safe_total_inner(childrel->pathlist);
1418
1419 if (cheapest_partial_path == NULL && nppath == NULL)
1420 {
1421 /* Neither a partial nor a parallel-safe path? Forget it. */
1422 pa_subpaths_valid = false;
1423 }
1424 else if (nppath == NULL ||
1425 (cheapest_partial_path != NULL &&
1426 cheapest_partial_path->total_cost < nppath->total_cost))
1427 {
1428 /* Partial path is cheaper or the only option. */
1429 Assert(cheapest_partial_path != NULL);
1430 accumulate_append_subpath(cheapest_partial_path,
1431 &pa_partial_subpaths,
1432 &pa_nonpartial_subpaths);
1433 }
1434 else
1435 {
1436 /*
1437 * Either we've got only a non-partial path, or we think that
1438 * a single backend can execute the best non-partial path
1439 * faster than all the parallel backends working together can
1440 * execute the best partial path.
1441 *
1442 * It might make sense to be more aggressive here. Even if
1443 * the best non-partial path is more expensive than the best
1444 * partial path, it could still be better to choose the
1445 * non-partial path if there are several such paths that can
1446 * be given to different workers. For now, we don't try to
1447 * figure that out.
1448 */
1449 accumulate_append_subpath(nppath,
1450 &pa_nonpartial_subpaths,
1451 NULL);
1452 }
1453 }
1454
1455 /*
1456 * Collect lists of all the available path orderings and
1457 * parameterizations for all the children. We use these as a
1458 * heuristic to indicate which sort orderings and parameterizations we
1459 * should build Append and MergeAppend paths for.
1460 */
1461 foreach(lcp, childrel->pathlist)
1462 {
1463 Path *childpath = (Path *) lfirst(lcp);
1464 List *childkeys = childpath->pathkeys;
1465 Relids childouter = PATH_REQ_OUTER(childpath);
1466
1467 /* Unsorted paths don't contribute to pathkey list */
1468 if (childkeys != NIL)
1469 {
1470 ListCell *lpk;
1471 bool found = false;
1472
1473 /* Have we already seen this ordering? */
1474 foreach(lpk, all_child_pathkeys)
1475 {
1476 List *existing_pathkeys = (List *) lfirst(lpk);
1477
1478 if (compare_pathkeys(existing_pathkeys,
1479 childkeys) == PATHKEYS_EQUAL)
1480 {
1481 found = true;
1482 break;
1483 }
1484 }
1485 if (!found)
1486 {
1487 /* No, so add it to all_child_pathkeys */
1488 all_child_pathkeys = lappend(all_child_pathkeys,
1489 childkeys);
1490 }
1491 }
1492
1493 /* Unparameterized paths don't contribute to param-set list */
1494 if (childouter)
1495 {
1496 ListCell *lco;
1497 bool found = false;
1498
1499 /* Have we already seen this param set? */
1500 foreach(lco, all_child_outers)
1501 {
1502 Relids existing_outers = (Relids) lfirst(lco);
1503
1504 if (bms_equal(existing_outers, childouter))
1505 {
1506 found = true;
1507 break;
1508 }
1509 }
1510 if (!found)
1511 {
1512 /* No, so add it to all_child_outers */
1513 all_child_outers = lappend(all_child_outers,
1514 childouter);
1515 }
1516 }
1517 }
1518 }
1519
1520 /*
1521 * If we found unparameterized paths for all children, build an unordered,
1522 * unparameterized Append path for the rel. (Note: this is correct even
1523 * if we have zero or one live subpath due to constraint exclusion.)
1524 */
1525 if (subpaths_valid)
1526 add_path(rel, (Path *) create_append_path(root, rel, subpaths, NIL,
1527 NIL, NULL, 0, false,
1528 -1));
1529
1530 /* build an AppendPath for the cheap startup paths, if valid */
1531 if (startup_subpaths_valid)
1532 add_path(rel, (Path *) create_append_path(root, rel, startup_subpaths,
1533 NIL, NIL, NULL, 0, false, -1));
1534
1535 /*
1536 * Consider an append of unordered, unparameterized partial paths. Make
1537 * it parallel-aware if possible.
1538 */
1539 if (partial_subpaths_valid && partial_subpaths != NIL)
1540 {
1541 AppendPath *appendpath;
1542 ListCell *lc;
1543 int parallel_workers = 0;
1544
1545 /* Find the highest number of workers requested for any subpath. */
1546 foreach(lc, partial_subpaths)
1547 {
1548 Path *path = lfirst(lc);
1549
1550 parallel_workers = Max(parallel_workers, path->parallel_workers);
1551 }
1552 Assert(parallel_workers > 0);
1553
1554 /*
1555 * If the use of parallel append is permitted, always request at least
1556 * log2(# of children) workers. We assume it can be useful to have
1557 * extra workers in this case because they will be spread out across
1558 * the children. The precise formula is just a guess, but we don't
1559 * want to end up with a radically different answer for a table with N
1560 * partitions vs. an unpartitioned table with the same data, so the
1561 * use of some kind of log-scaling here seems to make some sense.
1562 */
1563 if (enable_parallel_append)
1564 {
1565 parallel_workers = Max(parallel_workers,
1566 pg_leftmost_one_pos32(list_length(live_childrels)) + 1);
1567 parallel_workers = Min(parallel_workers,
1568 max_parallel_workers_per_gather);
1569 }
1570 Assert(parallel_workers > 0);
1571
1572 /* Generate a partial append path. */
1573 appendpath = create_append_path(root, rel, NIL, partial_subpaths,
1574 NIL, NULL, parallel_workers,
1575 enable_parallel_append,
1576 -1);
1577
1578 /*
1579 * Make sure any subsequent partial paths use the same row count
1580 * estimate.
1581 */
1582 partial_rows = appendpath->path.rows;
1583
1584 /* Add the path. */
1585 add_partial_path(rel, (Path *) appendpath);
1586 }
1587
1588 /*
1589 * Consider a parallel-aware append using a mix of partial and non-partial
1590 * paths. (This only makes sense if there's at least one child which has
1591 * a non-partial path that is substantially cheaper than any partial path;
1592 * otherwise, we should use the append path added in the previous step.)
1593 */
1594 if (pa_subpaths_valid && pa_nonpartial_subpaths != NIL)
1595 {
1596 AppendPath *appendpath;
1597 ListCell *lc;
1598 int parallel_workers = 0;
1599
1600 /*
1601 * Find the highest number of workers requested for any partial
1602 * subpath.
1603 */
1604 foreach(lc, pa_partial_subpaths)
1605 {
1606 Path *path = lfirst(lc);
1607
1608 parallel_workers = Max(parallel_workers, path->parallel_workers);
1609 }
1610
1611 /*
1612 * Same formula here as above. It's even more important in this
1613 * instance because the non-partial paths won't contribute anything to
1614 * the planned number of parallel workers.
1615 */
1616 parallel_workers = Max(parallel_workers,
1617 pg_leftmost_one_pos32(list_length(live_childrels)) + 1);
1618 parallel_workers = Min(parallel_workers,
1619 max_parallel_workers_per_gather);
1620 Assert(parallel_workers > 0);
1621
1622 appendpath = create_append_path(root, rel, pa_nonpartial_subpaths,
1623 pa_partial_subpaths,
1624 NIL, NULL, parallel_workers, true,
1625 partial_rows);
1626 add_partial_path(rel, (Path *) appendpath);
1627 }
1628
1629 /*
1630 * Also build unparameterized ordered append paths based on the collected
1631 * list of child pathkeys.
1632 */
1633 if (subpaths_valid)
1634 generate_orderedappend_paths(root, rel, live_childrels,
1635 all_child_pathkeys);
1636
1637 /*
1638 * Build Append paths for each parameterization seen among the child rels.
1639 * (This may look pretty expensive, but in most cases of practical
1640 * interest, the child rels will expose mostly the same parameterizations,
1641 * so that not that many cases actually get considered here.)
1642 *
1643 * The Append node itself cannot enforce quals, so all qual checking must
1644 * be done in the child paths. This means that to have a parameterized
1645 * Append path, we must have the exact same parameterization for each
1646 * child path; otherwise some children might be failing to check the
1647 * moved-down quals. To make them match up, we can try to increase the
1648 * parameterization of lesser-parameterized paths.
1649 */
1650 foreach(l, all_child_outers)
1651 {
1652 Relids required_outer = (Relids) lfirst(l);
1653 ListCell *lcr;
1654
1655 /* Select the child paths for an Append with this parameterization */
1656 subpaths = NIL;
1657 subpaths_valid = true;
1658 foreach(lcr, live_childrels)
1659 {
1660 RelOptInfo *childrel = (RelOptInfo *) lfirst(lcr);
1661 Path *subpath;
1662
1663 if (childrel->pathlist == NIL)
1664 {
1665 /* failed to make a suitable path for this child */
1666 subpaths_valid = false;
1667 break;
1668 }
1669
1670 subpath = get_cheapest_parameterized_child_path(root,
1671 childrel,
1672 required_outer);
1673 if (subpath == NULL)
1674 {
1675 /* failed to make a suitable path for this child */
1676 subpaths_valid = false;
1677 break;
1678 }
1679 accumulate_append_subpath(subpath, &subpaths, NULL);
1680 }
1681
1682 if (subpaths_valid)
1683 add_path(rel, (Path *)
1684 create_append_path(root, rel, subpaths, NIL,
1685 NIL, required_outer, 0, false,
1686 -1));
1687 }
1688
1689 /*
1690 * When there is only a single child relation, the Append path can inherit
1691 * any ordering available for the child rel's path, so that it's useful to
1692 * consider ordered partial paths. Above we only considered the cheapest
1693 * partial path for each child, but let's also make paths using any
1694 * partial paths that have pathkeys.
1695 */
1696 if (list_length(live_childrels) == 1)
1697 {
1698 RelOptInfo *childrel = (RelOptInfo *) linitial(live_childrels);
1699
1700 /* skip the cheapest partial path, since we already used that above */
1701 for_each_from(l, childrel->partial_pathlist, 1)
1702 {
1703 Path *path = (Path *) lfirst(l);
1704 AppendPath *appendpath;
1705
1706 /* skip paths with no pathkeys. */
1707 if (path->pathkeys == NIL)
1708 continue;
1709
1710 appendpath = create_append_path(root, rel, NIL, list_make1(path),
1711 NIL, NULL,
1712 path->parallel_workers, true,
1713 partial_rows);
1714 add_partial_path(rel, (Path *) appendpath);
1715 }
1716 }
1717}
1718
1719/*
1720 * generate_orderedappend_paths
1721 * Generate ordered append paths for an append relation
1722 *
1723 * Usually we generate MergeAppend paths here, but there are some special
1724 * cases where we can generate simple Append paths, because the subpaths
1725 * can provide tuples in the required order already.
1726 *
1727 * We generate a path for each ordering (pathkey list) appearing in
1728 * all_child_pathkeys.
1729 *
1730 * We consider both cheapest-startup and cheapest-total cases, ie, for each
1731 * interesting ordering, collect all the cheapest startup subpaths and all the
1732 * cheapest total paths, and build a suitable path for each case.
1733 *
1734 * We don't currently generate any parameterized ordered paths here. While
1735 * it would not take much more code here to do so, it's very unclear that it
1736 * is worth the planning cycles to investigate such paths: there's little
1737 * use for an ordered path on the inside of a nestloop. In fact, it's likely
1738 * that the current coding of add_path would reject such paths out of hand,
1739 * because add_path gives no credit for sort ordering of parameterized paths,
1740 * and a parameterized MergeAppend is going to be more expensive than the
1741 * corresponding parameterized Append path. If we ever try harder to support
1742 * parameterized mergejoin plans, it might be worth adding support for
1743 * parameterized paths here to feed such joins. (See notes in
1744 * optimizer/README for why that might not ever happen, though.)
1745 */
1746static void
1747generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel,
1748 List *live_childrels,
1749 List *all_child_pathkeys)
1750{
1751 ListCell *lcp;
1752 List *partition_pathkeys = NIL;
1753 List *partition_pathkeys_desc = NIL;
1754 bool partition_pathkeys_partial = true;
1755 bool partition_pathkeys_desc_partial = true;
1756
1757 /*
1758 * Some partitioned table setups may allow us to use an Append node
1759 * instead of a MergeAppend. This is possible in cases such as RANGE
1760 * partitioned tables where it's guaranteed that an earlier partition must
1761 * contain rows which come earlier in the sort order. To detect whether
1762 * this is relevant, build pathkey descriptions of the partition ordering,
1763 * for both forward and reverse scans.
1764 */
1765 if (rel->part_scheme != NULL && IS_SIMPLE_REL(rel) &&
1766 partitions_are_ordered(rel->boundinfo, rel->live_parts))
1767 {
1768 partition_pathkeys = build_partition_pathkeys(root, rel,
1769 ForwardScanDirection,
1770 &partition_pathkeys_partial);
1771
1772 partition_pathkeys_desc = build_partition_pathkeys(root, rel,
1773 BackwardScanDirection,
1774 &partition_pathkeys_desc_partial);
1775
1776 /*
1777 * You might think we should truncate_useless_pathkeys here, but
1778 * allowing partition keys which are a subset of the query's pathkeys
1779 * can often be useful. For example, consider a table partitioned by
1780 * RANGE (a, b), and a query with ORDER BY a, b, c. If we have child
1781 * paths that can produce the a, b, c ordering (perhaps via indexes on
1782 * (a, b, c)) then it works to consider the appendrel output as
1783 * ordered by a, b, c.
1784 */
1785 }
1786
1787 /* Now consider each interesting sort ordering */
1788 foreach(lcp, all_child_pathkeys)
1789 {
1790 List *pathkeys = (List *) lfirst(lcp);
1791 List *startup_subpaths = NIL;
1792 List *total_subpaths = NIL;
1793 List *fractional_subpaths = NIL;
1794 bool startup_neq_total = false;
1795 bool match_partition_order;
1796 bool match_partition_order_desc;
1797 int end_index;
1798 int first_index;
1799 int direction;
1800
1801 /*
1802 * Determine if this sort ordering matches any partition pathkeys we
1803 * have, for both ascending and descending partition order. If the
1804 * partition pathkeys happen to be contained in pathkeys then it still
1805 * works, as described above, providing that the partition pathkeys
1806 * are complete and not just a prefix of the partition keys. (In such
1807 * cases we'll be relying on the child paths to have sorted the
1808 * lower-order columns of the required pathkeys.)
1809 */
1810 match_partition_order =
1811 pathkeys_contained_in(pathkeys, partition_pathkeys) ||
1812 (!partition_pathkeys_partial &&
1813 pathkeys_contained_in(partition_pathkeys, pathkeys));
1814
1815 match_partition_order_desc = !match_partition_order &&
1816 (pathkeys_contained_in(pathkeys, partition_pathkeys_desc) ||
1817 (!partition_pathkeys_desc_partial &&
1818 pathkeys_contained_in(partition_pathkeys_desc, pathkeys)));
1819
1820 /*
1821 * When the required pathkeys match the reverse of the partition
1822 * order, we must build the list of paths in reverse starting with the
1823 * last matching partition first. We can get away without making any
1824 * special cases for this in the loop below by just looping backward
1825 * over the child relations in this case.
1826 */
1827 if (match_partition_order_desc)
1828 {
1829 /* loop backward */
1830 first_index = list_length(live_childrels) - 1;
1831 end_index = -1;
1832 direction = -1;
1833
1834 /*
1835 * Set this to true to save us having to check for
1836 * match_partition_order_desc in the loop below.
1837 */
1838 match_partition_order = true;
1839 }
1840 else
1841 {
1842 /* for all other case, loop forward */
1843 first_index = 0;
1844 end_index = list_length(live_childrels);
1845 direction = 1;
1846 }
1847
1848 /* Select the child paths for this ordering... */
1849 for (int i = first_index; i != end_index; i += direction)
1850 {
1851 RelOptInfo *childrel = list_nth_node(RelOptInfo, live_childrels, i);
1852 Path *cheapest_startup,
1853 *cheapest_total,
1854 *cheapest_fractional = NULL;
1855
1856 /* Locate the right paths, if they are available. */
1857 cheapest_startup =
1858 get_cheapest_path_for_pathkeys(childrel->pathlist,
1859 pathkeys,
1860 NULL,
1861 STARTUP_COST,
1862 false);
1863 cheapest_total =
1864 get_cheapest_path_for_pathkeys(childrel->pathlist,
1865 pathkeys,
1866 NULL,
1867 TOTAL_COST,
1868 false);
1869
1870 /*
1871 * If we can't find any paths with the right order just use the
1872 * cheapest-total path; we'll have to sort it later.
1873 */
1874 if (cheapest_startup == NULL || cheapest_total == NULL)
1875 {
1876 cheapest_startup = cheapest_total =
1877 childrel->cheapest_total_path;
1878 /* Assert we do have an unparameterized path for this child */
1879 Assert(cheapest_total->param_info == NULL);
1880 }
1881
1882 /*
1883 * When building a fractional path, determine a cheapest
1884 * fractional path for each child relation too. Looking at startup
1885 * and total costs is not enough, because the cheapest fractional
1886 * path may be dominated by two separate paths (one for startup,
1887 * one for total).
1888 *
1889 * When needed (building fractional path), determine the cheapest
1890 * fractional path too.
1891 */
1892 if (root->tuple_fraction > 0)
1893 {
1894 double path_fraction = root->tuple_fraction;
1895
1896 /*
1897 * Merge Append considers only live children relations. Dummy
1898 * relations must be filtered out before.
1899 */
1900 Assert(childrel->rows > 0);
1901
1902 /* Convert absolute limit to a path fraction */
1903 if (path_fraction >= 1.0)
1904 path_fraction /= childrel->rows;
1905
1906 cheapest_fractional =
1907 get_cheapest_fractional_path_for_pathkeys(childrel->pathlist,
1908 pathkeys,
1909 NULL,
1910 path_fraction);
1911
1912 /*
1913 * If we found no path with matching pathkeys, use the
1914 * cheapest total path instead.
1915 *
1916 * XXX We might consider partially sorted paths too (with an
1917 * incremental sort on top). But we'd have to build all the
1918 * incremental paths, do the costing etc.
1919 */
1920 if (!cheapest_fractional)
1921 cheapest_fractional = cheapest_total;
1922 }
1923
1924 /*
1925 * Notice whether we actually have different paths for the
1926 * "cheapest" and "total" cases; frequently there will be no point
1927 * in two create_merge_append_path() calls.
1928 */
1929 if (cheapest_startup != cheapest_total)
1930 startup_neq_total = true;
1931
1932 /*
1933 * Collect the appropriate child paths. The required logic varies
1934 * for the Append and MergeAppend cases.
1935 */
1936 if (match_partition_order)
1937 {
1938 /*
1939 * We're going to make a plain Append path. We don't need
1940 * most of what accumulate_append_subpath would do, but we do
1941 * want to cut out child Appends or MergeAppends if they have
1942 * just a single subpath (and hence aren't doing anything
1943 * useful).
1944 */
1945 cheapest_startup = get_singleton_append_subpath(cheapest_startup);
1946 cheapest_total = get_singleton_append_subpath(cheapest_total);
1947
1948 startup_subpaths = lappend(startup_subpaths, cheapest_startup);
1949 total_subpaths = lappend(total_subpaths, cheapest_total);
1950
1951 if (cheapest_fractional)
1952 {
1953 cheapest_fractional = get_singleton_append_subpath(cheapest_fractional);
1954 fractional_subpaths = lappend(fractional_subpaths, cheapest_fractional);
1955 }
1956 }
1957 else
1958 {
1959 /*
1960 * Otherwise, rely on accumulate_append_subpath to collect the
1961 * child paths for the MergeAppend.
1962 */
1963 accumulate_append_subpath(cheapest_startup,
1964 &startup_subpaths, NULL);
1965 accumulate_append_subpath(cheapest_total,
1966 &total_subpaths, NULL);
1967
1968 if (cheapest_fractional)
1969 accumulate_append_subpath(cheapest_fractional,
1970 &fractional_subpaths, NULL);
1971 }
1972 }
1973
1974 /* ... and build the Append or MergeAppend paths */
1975 if (match_partition_order)
1976 {
1977 /* We only need Append */
1978 add_path(rel, (Path *) create_append_path(root,
1979 rel,
1980 startup_subpaths,
1981 NIL,
1982 pathkeys,
1983 NULL,
1984 0,
1985 false,
1986 -1));
1987 if (startup_neq_total)
1988 add_path(rel, (Path *) create_append_path(root,
1989 rel,
1990 total_subpaths,
1991 NIL,
1992 pathkeys,
1993 NULL,
1994 0,
1995 false,
1996 -1));
1997
1998 if (fractional_subpaths)
1999 add_path(rel, (Path *) create_append_path(root,
2000 rel,
2001 fractional_subpaths,
2002 NIL,
2003 pathkeys,
2004 NULL,
2005 0,
2006 false,
2007 -1));
2008 }
2009 else
2010 {
2011 /* We need MergeAppend */
2012 add_path(rel, (Path *) create_merge_append_path(root,
2013 rel,
2014 startup_subpaths,
2015 pathkeys,
2016 NULL));
2017 if (startup_neq_total)
2018 add_path(rel, (Path *) create_merge_append_path(root,
2019 rel,
2020 total_subpaths,
2021 pathkeys,
2022 NULL));
2023
2024 if (fractional_subpaths)
2025 add_path(rel, (Path *) create_merge_append_path(root,
2026 rel,
2027 fractional_subpaths,
2028 pathkeys,
2029 NULL));
2030 }
2031 }
2032}
2033
2034/*
2035 * get_cheapest_parameterized_child_path
2036 * Get cheapest path for this relation that has exactly the requested
2037 * parameterization.
2038 *
2039 * Returns NULL if unable to create such a path.
2040 */
2041static Path *
2042get_cheapest_parameterized_child_path(PlannerInfo *root, RelOptInfo *rel,
2043 Relids required_outer)
2044{
2045 Path *cheapest;
2046 ListCell *lc;
2047
2048 /*
2049 * Look up the cheapest existing path with no more than the needed
2050 * parameterization. If it has exactly the needed parameterization, we're
2051 * done.
2052 */
2053 cheapest = get_cheapest_path_for_pathkeys(rel->pathlist,
2054 NIL,
2055 required_outer,
2056 TOTAL_COST,
2057 false);
2058 Assert(cheapest != NULL);
2059 if (bms_equal(PATH_REQ_OUTER(cheapest), required_outer))
2060 return cheapest;
2061
2062 /*
2063 * Otherwise, we can "reparameterize" an existing path to match the given
2064 * parameterization, which effectively means pushing down additional
2065 * joinquals to be checked within the path's scan. However, some existing
2066 * paths might check the available joinquals already while others don't;
2067 * therefore, it's not clear which existing path will be cheapest after
2068 * reparameterization. We have to go through them all and find out.
2069 */
2070 cheapest = NULL;
2071 foreach(lc, rel->pathlist)
2072 {
2073 Path *path = (Path *) lfirst(lc);
2074
2075 /* Can't use it if it needs more than requested parameterization */
2076 if (!bms_is_subset(PATH_REQ_OUTER(path), required_outer))
2077 continue;
2078
2079 /*
2080 * Reparameterization can only increase the path's cost, so if it's
2081 * already more expensive than the current cheapest, forget it.
2082 */
2083 if (cheapest != NULL &&
2084 compare_path_costs(cheapest, path, TOTAL_COST) <= 0)
2085 continue;
2086
2087 /* Reparameterize if needed, then recheck cost */
2088 if (!bms_equal(PATH_REQ_OUTER(path), required_outer))
2089 {
2090 path = reparameterize_path(root, path, required_outer, 1.0);
2091 if (path == NULL)
2092 continue; /* failed to reparameterize this one */
2093 Assert(bms_equal(PATH_REQ_OUTER(path), required_outer));
2094
2095 if (cheapest != NULL &&
2096 compare_path_costs(cheapest, path, TOTAL_COST) <= 0)
2097 continue;
2098 }
2099
2100 /* We have a new best path */
2101 cheapest = path;
2102 }
2103
2104 /* Return the best path, or NULL if we found no suitable candidate */
2105 return cheapest;
2106}
2107
2108/*
2109 * accumulate_append_subpath
2110 * Add a subpath to the list being built for an Append or MergeAppend.
2111 *
2112 * It's possible that the child is itself an Append or MergeAppend path, in
2113 * which case we can "cut out the middleman" and just add its child paths to
2114 * our own list. (We don't try to do this earlier because we need to apply
2115 * both levels of transformation to the quals.)
2116 *
2117 * Note that if we omit a child MergeAppend in this way, we are effectively
2118 * omitting a sort step, which seems fine: if the parent is to be an Append,
2119 * its result would be unsorted anyway, while if the parent is to be a
2120 * MergeAppend, there's no point in a separate sort on a child.
2121 *
2122 * Normally, either path is a partial path and subpaths is a list of partial
2123 * paths, or else path is a non-partial plan and subpaths is a list of those.
2124 * However, if path is a parallel-aware Append, then we add its partial path
2125 * children to subpaths and the rest to special_subpaths. If the latter is
2126 * NULL, we don't flatten the path at all (unless it contains only partial
2127 * paths).
2128 */
2129static void
2130accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths)
2131{
2132 if (IsA(path, AppendPath))
2133 {
2134 AppendPath *apath = (AppendPath *) path;
2135
2136 if (!apath->path.parallel_aware || apath->first_partial_path == 0)
2137 {
2138 *subpaths = list_concat(*subpaths, apath->subpaths);
2139 return;
2140 }
2141 else if (special_subpaths != NULL)
2142 {
2143 List *new_special_subpaths;
2144
2145 /* Split Parallel Append into partial and non-partial subpaths */
2146 *subpaths = list_concat(*subpaths,
2147 list_copy_tail(apath->subpaths,
2148 apath->first_partial_path));
2149 new_special_subpaths = list_copy_head(apath->subpaths,
2150 apath->first_partial_path);
2151 *special_subpaths = list_concat(*special_subpaths,
2152 new_special_subpaths);
2153 return;
2154 }
2155 }
2156 else if (IsA(path, MergeAppendPath))
2157 {
2158 MergeAppendPath *mpath = (MergeAppendPath *) path;
2159
2160 *subpaths = list_concat(*subpaths, mpath->subpaths);
2161 return;
2162 }
2163
2164 *subpaths = lappend(*subpaths, path);
2165}
2166
2167/*
2168 * get_singleton_append_subpath
2169 * Returns the single subpath of an Append/MergeAppend, or just
2170 * return 'path' if it's not a single sub-path Append/MergeAppend.
2171 *
2172 * Note: 'path' must not be a parallel-aware path.
2173 */
2174static Path *
2175get_singleton_append_subpath(Path *path)
2176{
2177 Assert(!path->parallel_aware);
2178
2179 if (IsA(path, AppendPath))
2180 {
2181 AppendPath *apath = (AppendPath *) path;
2182
2183 if (list_length(apath->subpaths) == 1)
2184 return (Path *) linitial(apath->subpaths);
2185 }
2186 else if (IsA(path, MergeAppendPath))
2187 {
2188 MergeAppendPath *mpath = (MergeAppendPath *) path;
2189
2190 if (list_length(mpath->subpaths) == 1)
2191 return (Path *) linitial(mpath->subpaths);
2192 }
2193
2194 return path;
2195}
2196
2197/*
2198 * set_dummy_rel_pathlist
2199 * Build a dummy path for a relation that's been excluded by constraints
2200 *
2201 * Rather than inventing a special "dummy" path type, we represent this as an
2202 * AppendPath with no members (see also IS_DUMMY_APPEND/IS_DUMMY_REL macros).
2203 *
2204 * (See also mark_dummy_rel, which does basically the same thing, but is
2205 * typically used to change a rel into dummy state after we already made
2206 * paths for it.)
2207 */
2208static void
2209set_dummy_rel_pathlist(RelOptInfo *rel)
2210{
2211 /* Set dummy size estimates --- we leave attr_widths[] as zeroes */
2212 rel->rows = 0;
2213 rel->reltarget->width = 0;
2214
2215 /* Discard any pre-existing paths; no further need for them */
2216 rel->pathlist = NIL;
2217 rel->partial_pathlist = NIL;
2218
2219 /* Set up the dummy path */
2220 add_path(rel, (Path *) create_append_path(NULL, rel, NIL, NIL,
2221 NIL, rel->lateral_relids,
2222 0, false, -1));
2223
2224 /*
2225 * We set the cheapest-path fields immediately, just in case they were
2226 * pointing at some discarded path. This is redundant in current usage
2227 * because set_rel_pathlist will do it later, but it's cheap so we keep it
2228 * for safety and consistency with mark_dummy_rel.
2229 */
2230 set_cheapest(rel);
2231}
2232
2233/*
2234 * find_window_run_conditions
2235 * Determine if 'wfunc' is really a WindowFunc and call its prosupport
2236 * function to determine the function's monotonic properties. We then
2237 * see if 'opexpr' can be used to short-circuit execution.
2238 *
2239 * For example row_number() over (order by ...) always produces a value one
2240 * higher than the previous. If someone has a window function in a subquery
2241 * and has a WHERE clause in the outer query to filter rows <= 10, then we may
2242 * as well stop processing the windowagg once the row number reaches 11. Here
2243 * we check if 'opexpr' might help us to stop doing needless extra processing
2244 * in WindowAgg nodes.
2245 *
2246 * '*keep_original' is set to true if the caller should also use 'opexpr' for
2247 * its original purpose. This is set to false if the caller can assume that
2248 * the run condition will handle all of the required filtering.
2249 *
2250 * Returns true if 'opexpr' was found to be useful and was added to the
2251 * WindowFunc's runCondition. We also set *keep_original accordingly and add
2252 * 'attno' to *run_cond_attrs offset by FirstLowInvalidHeapAttributeNumber.
2253 * If the 'opexpr' cannot be used then we set *keep_original to true and
2254 * return false.
2255 */
2256static bool
2257find_window_run_conditions(Query *subquery, RangeTblEntry *rte, Index rti,
2258 AttrNumber attno, WindowFunc *wfunc, OpExpr *opexpr,
2259 bool wfunc_left, bool *keep_original,
2260 Bitmapset **run_cond_attrs)
2261{
2262 Oid prosupport;
2263 Expr *otherexpr;
2264 SupportRequestWFuncMonotonic req;
2265 SupportRequestWFuncMonotonic *res;
2266 WindowClause *wclause;
2267 List *opinfos;
2268 OpExpr *runopexpr;
2269 Oid runoperator;
2270 ListCell *lc;
2271
2272 *keep_original = true;
2273
2274 while (IsA(wfunc, RelabelType))
2275 wfunc = (WindowFunc *) ((RelabelType *) wfunc)->arg;
2276
2277 /* we can only work with window functions */
2278 if (!IsA(wfunc, WindowFunc))
2279 return false;
2280
2281 /* can't use it if there are subplans in the WindowFunc */
2282 if (contain_subplans((Node *) wfunc))
2283 return false;
2284
2285 prosupport = get_func_support(wfunc->winfnoid);
2286
2287 /* Check if there's a support function for 'wfunc' */
2288 if (!OidIsValid(prosupport))
2289 return false;
2290
2291 /* get the Expr from the other side of the OpExpr */
2292 if (wfunc_left)
2293 otherexpr = lsecond(opexpr->args);
2294 else
2295 otherexpr = linitial(opexpr->args);
2296
2297 /*
2298 * The value being compared must not change during the evaluation of the
2299 * window partition.
2300 */
2301 if (!is_pseudo_constant_clause((Node *) otherexpr))
2302 return false;
2303
2304 /* find the window clause belonging to the window function */
2305 wclause = (WindowClause *) list_nth(subquery->windowClause,
2306 wfunc->winref - 1);
2307
2308 req.type = T_SupportRequestWFuncMonotonic;
2309 req.window_func = wfunc;
2310 req.window_clause = wclause;
2311
2312 /* call the support function */
2313 res = (SupportRequestWFuncMonotonic *)
2314 DatumGetPointer(OidFunctionCall1(prosupport,
2315 PointerGetDatum(&req)));
2316
2317 /*
2318 * Nothing to do if the function is neither monotonically increasing nor
2319 * monotonically decreasing.
2320 */
2321 if (res == NULL || res->monotonic == MONOTONICFUNC_NONE)
2322 return false;
2323
2324 runopexpr = NULL;
2325 runoperator = InvalidOid;
2326 opinfos = get_op_index_interpretation(opexpr->opno);
2327
2328 foreach(lc, opinfos)
2329 {
2330 OpIndexInterpretation *opinfo = (OpIndexInterpretation *) lfirst(lc);
2331 CompareType cmptype = opinfo->cmptype;
2332
2333 /* handle < / <= */
2334 if (cmptype == COMPARE_LT || cmptype == COMPARE_LE)
2335 {
2336 /*
2337 * < / <= is supported for monotonically increasing functions in
2338 * the form <wfunc> op <pseudoconst> and <pseudoconst> op <wfunc>
2339 * for monotonically decreasing functions.
2340 */
2341 if ((wfunc_left && (res->monotonic & MONOTONICFUNC_INCREASING)) ||
2342 (!wfunc_left && (res->monotonic & MONOTONICFUNC_DECREASING)))
2343 {
2344 *keep_original = false;
2345 runopexpr = opexpr;
2346 runoperator = opexpr->opno;
2347 }
2348 break;
2349 }
2350 /* handle > / >= */
2351 else if (cmptype == COMPARE_GT || cmptype == COMPARE_GE)
2352 {
2353 /*
2354 * > / >= is supported for monotonically decreasing functions in
2355 * the form <wfunc> op <pseudoconst> and <pseudoconst> op <wfunc>
2356 * for monotonically increasing functions.
2357 */
2358 if ((wfunc_left && (res->monotonic & MONOTONICFUNC_DECREASING)) ||
2359 (!wfunc_left && (res->monotonic & MONOTONICFUNC_INCREASING)))
2360 {
2361 *keep_original = false;
2362 runopexpr = opexpr;
2363 runoperator = opexpr->opno;
2364 }
2365 break;
2366 }
2367 /* handle = */
2368 else if (cmptype == COMPARE_EQ)
2369 {
2370 CompareType newcmptype;
2371
2372 /*
2373 * When both monotonically increasing and decreasing then the
2374 * return value of the window function will be the same each time.
2375 * We can simply use 'opexpr' as the run condition without
2376 * modifying it.
2377 */
2378 if ((res->monotonic & MONOTONICFUNC_BOTH) == MONOTONICFUNC_BOTH)
2379 {
2380 *keep_original = false;
2381 runopexpr = opexpr;
2382 runoperator = opexpr->opno;
2383 break;
2384 }
2385
2386 /*
2387 * When monotonically increasing we make a qual with <wfunc> <=
2388 * <value> or <value> >= <wfunc> in order to filter out values
2389 * which are above the value in the equality condition. For
2390 * monotonically decreasing functions we want to filter values
2391 * below the value in the equality condition.
2392 */
2393 if (res->monotonic & MONOTONICFUNC_INCREASING)
2394 newcmptype = wfunc_left ? COMPARE_LE : COMPARE_GE;
2395 else
2396 newcmptype = wfunc_left ? COMPARE_GE : COMPARE_LE;
2397
2398 /* We must keep the original equality qual */
2399 *keep_original = true;
2400 runopexpr = opexpr;
2401
2402 /* determine the operator to use for the WindowFuncRunCondition */
2403 runoperator = get_opfamily_member_for_cmptype(opinfo->opfamily_id,
2404 opinfo->oplefttype,
2405 opinfo->oprighttype,
2406 newcmptype);
2407 break;
2408 }
2409 }
2410
2411 if (runopexpr != NULL)
2412 {
2413 WindowFuncRunCondition *wfuncrc;
2414
2415 wfuncrc = makeNode(WindowFuncRunCondition);
2416 wfuncrc->opno = runoperator;
2417 wfuncrc->inputcollid = runopexpr->inputcollid;
2418 wfuncrc->wfunc_left = wfunc_left;
2419 wfuncrc->arg = copyObject(otherexpr);
2420
2421 wfunc->runCondition = lappend(wfunc->runCondition, wfuncrc);
2422
2423 /* record that this attno was used in a run condition */
2424 *run_cond_attrs = bms_add_member(*run_cond_attrs,
2425 attno - FirstLowInvalidHeapAttributeNumber);
2426 return true;
2427 }
2428
2429 /* unsupported OpExpr */
2430 return false;
2431}
2432
2433/*
2434 * check_and_push_window_quals
2435 * Check if 'clause' is a qual that can be pushed into a WindowFunc
2436 * as a 'runCondition' qual. These, when present, allow some unnecessary
2437 * work to be skipped during execution.
2438 *
2439 * 'run_cond_attrs' will be populated with all targetlist resnos of subquery
2440 * targets (offset by FirstLowInvalidHeapAttributeNumber) that we pushed
2441 * window quals for.
2442 *
2443 * Returns true if the caller still must keep the original qual or false if
2444 * the caller can safely ignore the original qual because the WindowAgg node
2445 * will use the runCondition to stop returning tuples.
2446 */
2447static bool
2448check_and_push_window_quals(Query *subquery, RangeTblEntry *rte, Index rti,
2449 Node *clause, Bitmapset **run_cond_attrs)
2450{
2451 OpExpr *opexpr = (OpExpr *) clause;
2452 bool keep_original = true;
2453 Var *var1;
2454 Var *var2;
2455
2456 /* We're only able to use OpExprs with 2 operands */
2457 if (!IsA(opexpr, OpExpr))
2458 return true;
2459
2460 if (list_length(opexpr->args) != 2)
2461 return true;
2462
2463 /*
2464 * Currently, we restrict this optimization to strict OpExprs. The reason
2465 * for this is that during execution, once the runcondition becomes false,
2466 * we stop evaluating WindowFuncs. To avoid leaving around stale window
2467 * function result values, we set them to NULL. Having only strict
2468 * OpExprs here ensures that we properly filter out the tuples with NULLs
2469 * in the top-level WindowAgg.
2470 */
2471 set_opfuncid(opexpr);
2472 if (!func_strict(opexpr->opfuncid))
2473 return true;
2474
2475 /*
2476 * Check for plain Vars that reference window functions in the subquery.
2477 * If we find any, we'll ask find_window_run_conditions() if 'opexpr' can
2478 * be used as part of the run condition.
2479 */
2480
2481 /* Check the left side of the OpExpr */
2482 var1 = linitial(opexpr->args);
2483 if (IsA(var1, Var) && var1->varattno > 0)
2484 {
2485 TargetEntry *tle = list_nth(subquery->targetList, var1->varattno - 1);
2486 WindowFunc *wfunc = (WindowFunc *) tle->expr;
2487
2488 if (find_window_run_conditions(subquery, rte, rti, tle->resno, wfunc,
2489 opexpr, true, &keep_original,
2490 run_cond_attrs))
2491 return keep_original;
2492 }
2493
2494 /* and check the right side */
2495 var2 = lsecond(opexpr->args);
2496 if (IsA(var2, Var) && var2->varattno > 0)
2497 {
2498 TargetEntry *tle = list_nth(subquery->targetList, var2->varattno - 1);
2499 WindowFunc *wfunc = (WindowFunc *) tle->expr;
2500
2501 if (find_window_run_conditions(subquery, rte, rti, tle->resno, wfunc,
2502 opexpr, false, &keep_original,
2503 run_cond_attrs))
2504 return keep_original;
2505 }
2506
2507 return true;
2508}
2509
2510/*
2511 * set_subquery_pathlist
2512 * Generate SubqueryScan access paths for a subquery RTE
2513 *
2514 * We don't currently support generating parameterized paths for subqueries
2515 * by pushing join clauses down into them; it seems too expensive to re-plan
2516 * the subquery multiple times to consider different alternatives.
2517 * (XXX that could stand to be reconsidered, now that we use Paths.)
2518 * So the paths made here will be parameterized if the subquery contains
2519 * LATERAL references, otherwise not. As long as that's true, there's no need
2520 * for a separate set_subquery_size phase: just make the paths right away.
2521 */
2522static void
2523set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel,
2524 Index rti, RangeTblEntry *rte)
2525{
2526 Query *parse = root->parse;
2527 Query *subquery = rte->subquery;
2528 bool trivial_pathtarget;
2529 Relids required_outer;
2530 pushdown_safety_info safetyInfo;
2531 double tuple_fraction;
2532 RelOptInfo *sub_final_rel;
2533 Bitmapset *run_cond_attrs = NULL;
2534 ListCell *lc;
2535
2536 /*
2537 * Must copy the Query so that planning doesn't mess up the RTE contents
2538 * (really really need to fix the planner to not scribble on its input,
2539 * someday ... but see remove_unused_subquery_outputs to start with).
2540 */
2541 subquery = copyObject(subquery);
2542
2543 /*
2544 * If it's a LATERAL subquery, it might contain some Vars of the current
2545 * query level, requiring it to be treated as parameterized, even though
2546 * we don't support pushing down join quals into subqueries.
2547 */
2548 required_outer = rel->lateral_relids;
2549
2550 /*
2551 * Zero out result area for subquery_is_pushdown_safe, so that it can set
2552 * flags as needed while recursing. In particular, we need a workspace
2553 * for keeping track of the reasons why columns are unsafe to reference.
2554 * These reasons are stored in the bits inside unsafeFlags[i] when we
2555 * discover reasons that column i of the subquery is unsafe to be used in
2556 * a pushed-down qual.
2557 */
2558 memset(&safetyInfo, 0, sizeof(safetyInfo));
2559 safetyInfo.unsafeFlags = (unsigned char *)
2560 palloc0((list_length(subquery->targetList) + 1) * sizeof(unsigned char));
2561
2562 /*
2563 * If the subquery has the "security_barrier" flag, it means the subquery
2564 * originated from a view that must enforce row-level security. Then we
2565 * must not push down quals that contain leaky functions. (Ideally this
2566 * would be checked inside subquery_is_pushdown_safe, but since we don't
2567 * currently pass the RTE to that function, we must do it here.)
2568 */
2569 safetyInfo.unsafeLeaky = rte->security_barrier;
2570
2571 /*
2572 * If there are any restriction clauses that have been attached to the
2573 * subquery relation, consider pushing them down to become WHERE or HAVING
2574 * quals of the subquery itself. This transformation is useful because it
2575 * may allow us to generate a better plan for the subquery than evaluating
2576 * all the subquery output rows and then filtering them.
2577 *
2578 * There are several cases where we cannot push down clauses. Restrictions
2579 * involving the subquery are checked by subquery_is_pushdown_safe().
2580 * Restrictions on individual clauses are checked by
2581 * qual_is_pushdown_safe(). Also, we don't want to push down
2582 * pseudoconstant clauses; better to have the gating node above the
2583 * subquery.
2584 *
2585 * Non-pushed-down clauses will get evaluated as qpquals of the
2586 * SubqueryScan node.
2587 *
2588 * XXX Are there any cases where we want to make a policy decision not to
2589 * push down a pushable qual, because it'd result in a worse plan?
2590 */
2591 if (rel->baserestrictinfo != NIL &&
2592 subquery_is_pushdown_safe(subquery, subquery, &safetyInfo))
2593 {
2594 /* OK to consider pushing down individual quals */
2595 List *upperrestrictlist = NIL;
2596 ListCell *l;
2597
2598 foreach(l, rel->baserestrictinfo)
2599 {
2600 RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
2601 Node *clause = (Node *) rinfo->clause;
2602
2603 if (rinfo->pseudoconstant)
2604 {
2605 upperrestrictlist = lappend(upperrestrictlist, rinfo);
2606 continue;
2607 }
2608
2609 switch (qual_is_pushdown_safe(subquery, rti, rinfo, &safetyInfo))
2610 {
2611 case PUSHDOWN_SAFE:
2612 /* Push it down */
2613 subquery_push_qual(subquery, rte, rti, clause);
2614 break;
2615
2616 case PUSHDOWN_WINDOWCLAUSE_RUNCOND:
2617
2618 /*
2619 * Since we can't push the qual down into the subquery,
2620 * check if it happens to reference a window function. If
2621 * so then it might be useful to use for the WindowAgg's
2622 * runCondition.
2623 */
2624 if (!subquery->hasWindowFuncs ||
2625 check_and_push_window_quals(subquery, rte, rti, clause,
2626 &run_cond_attrs))
2627 {
2628 /*
2629 * subquery has no window funcs or the clause is not a
2630 * suitable window run condition qual or it is, but
2631 * the original must also be kept in the upper query.
2632 */
2633 upperrestrictlist = lappend(upperrestrictlist, rinfo);
2634 }
2635 break;
2636
2637 case PUSHDOWN_UNSAFE:
2638 upperrestrictlist = lappend(upperrestrictlist, rinfo);
2639 break;
2640 }
2641 }
2642 rel->baserestrictinfo = upperrestrictlist;
2643 /* We don't bother recomputing baserestrict_min_security */
2644 }
2645
2646 pfree(safetyInfo.unsafeFlags);
2647
2648 /*
2649 * The upper query might not use all the subquery's output columns; if
2650 * not, we can simplify. Pass the attributes that were pushed down into
2651 * WindowAgg run conditions to ensure we don't accidentally think those
2652 * are unused.
2653 */
2654 remove_unused_subquery_outputs(subquery, rel, run_cond_attrs);
2655
2656 /*
2657 * We can safely pass the outer tuple_fraction down to the subquery if the
2658 * outer level has no joining, aggregation, or sorting to do. Otherwise
2659 * we'd better tell the subquery to plan for full retrieval. (XXX This
2660 * could probably be made more intelligent ...)
2661 */
2662 if (parse->hasAggs ||
2663 parse->groupClause ||
2664 parse->groupingSets ||
2665 root->hasHavingQual ||
2666 parse->distinctClause ||
2667 parse->sortClause ||
2668 bms_membership(root->all_baserels) == BMS_MULTIPLE)
2669 tuple_fraction = 0.0; /* default case */
2670 else
2671 tuple_fraction = root->tuple_fraction;
2672
2673 /* plan_params should not be in use in current query level */
2674 Assert(root->plan_params == NIL);
2675
2676 /* Generate a subroot and Paths for the subquery */
2677 rel->subroot = subquery_planner(root->glob, subquery, root, false,
2678 tuple_fraction, NULL);
2679
2680 /* Isolate the params needed by this specific subplan */
2681 rel->subplan_params = root->plan_params;
2682 root->plan_params = NIL;
2683
2684 /*
2685 * It's possible that constraint exclusion proved the subquery empty. If
2686 * so, it's desirable to produce an unadorned dummy path so that we will
2687 * recognize appropriate optimizations at this query level.
2688 */
2689 sub_final_rel = fetch_upper_rel(rel->subroot, UPPERREL_FINAL, NULL);
2690
2691 if (IS_DUMMY_REL(sub_final_rel))
2692 {
2693 set_dummy_rel_pathlist(rel);
2694 return;
2695 }
2696
2697 /*
2698 * Mark rel with estimated output rows, width, etc. Note that we have to
2699 * do this before generating outer-query paths, else cost_subqueryscan is
2700 * not happy.
2701 */
2702 set_subquery_size_estimates(root, rel);
2703
2704 /*
2705 * Also detect whether the reltarget is trivial, so that we can pass that
2706 * info to cost_subqueryscan (rather than re-deriving it multiple times).
2707 * It's trivial if it fetches all the subplan output columns in order.
2708 */
2709 if (list_length(rel->reltarget->exprs) != list_length(subquery->targetList))
2710 trivial_pathtarget = false;
2711 else
2712 {
2713 trivial_pathtarget = true;
2714 foreach(lc, rel->reltarget->exprs)
2715 {
2716 Node *node = (Node *) lfirst(lc);
2717 Var *var;
2718
2719 if (!IsA(node, Var))
2720 {
2721 trivial_pathtarget = false;
2722 break;
2723 }
2724 var = (Var *) node;
2725 if (var->varno != rti ||
2726 var->varattno != foreach_current_index(lc) + 1)
2727 {
2728 trivial_pathtarget = false;
2729 break;
2730 }
2731 }
2732 }
2733
2734 /*
2735 * For each Path that subquery_planner produced, make a SubqueryScanPath
2736 * in the outer query.
2737 */
2738 foreach(lc, sub_final_rel->pathlist)
2739 {
2740 Path *subpath = (Path *) lfirst(lc);
2741 List *pathkeys;
2742
2743 /* Convert subpath's pathkeys to outer representation */
2744 pathkeys = convert_subquery_pathkeys(root,
2745 rel,
2746 subpath->pathkeys,
2747 make_tlist_from_pathtarget(subpath->pathtarget));
2748
2749 /* Generate outer path using this subpath */
2750 add_path(rel, (Path *)
2751 create_subqueryscan_path(root, rel, subpath,
2752 trivial_pathtarget,
2753 pathkeys, required_outer));
2754 }
2755
2756 /* If outer rel allows parallelism, do same for partial paths. */
2757 if (rel->consider_parallel && bms_is_empty(required_outer))
2758 {
2759 /* If consider_parallel is false, there should be no partial paths. */
2760 Assert(sub_final_rel->consider_parallel ||
2761 sub_final_rel->partial_pathlist == NIL);
2762
2763 /* Same for partial paths. */
2764 foreach(lc, sub_final_rel->partial_pathlist)
2765 {
2766 Path *subpath = (Path *) lfirst(lc);
2767 List *pathkeys;
2768
2769 /* Convert subpath's pathkeys to outer representation */
2770 pathkeys = convert_subquery_pathkeys(root,
2771 rel,
2772 subpath->pathkeys,
2773 make_tlist_from_pathtarget(subpath->pathtarget));
2774
2775 /* Generate outer path using this subpath */
2776 add_partial_path(rel, (Path *)
2777 create_subqueryscan_path(root, rel, subpath,
2778 trivial_pathtarget,
2779 pathkeys,
2780 required_outer));
2781 }
2782 }
2783}
2784
2785/*
2786 * set_function_pathlist
2787 * Build the (single) access path for a function RTE
2788 */
2789static void
2790set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2791{
2792 Relids required_outer;
2793 List *pathkeys = NIL;
2794
2795 /*
2796 * We don't support pushing join clauses into the quals of a function
2797 * scan, but it could still have required parameterization due to LATERAL
2798 * refs in the function expression.
2799 */
2800 required_outer = rel->lateral_relids;
2801
2802 /*
2803 * The result is considered unordered unless ORDINALITY was used, in which
2804 * case it is ordered by the ordinal column (the last one). See if we
2805 * care, by checking for uses of that Var in equivalence classes.
2806 */
2807 if (rte->funcordinality)
2808 {
2809 AttrNumber ordattno = rel->max_attr;
2810 Var *var = NULL;
2811 ListCell *lc;
2812
2813 /*
2814 * Is there a Var for it in rel's targetlist? If not, the query did
2815 * not reference the ordinality column, or at least not in any way
2816 * that would be interesting for sorting.
2817 */
2818 foreach(lc, rel->reltarget->exprs)
2819 {
2820 Var *node = (Var *) lfirst(lc);
2821
2822 /* checking varno/varlevelsup is just paranoia */
2823 if (IsA(node, Var) &&
2824 node->varattno == ordattno &&
2825 node->varno == rel->relid &&
2826 node->varlevelsup == 0)
2827 {
2828 var = node;
2829 break;
2830 }
2831 }
2832
2833 /*
2834 * Try to build pathkeys for this Var with int8 sorting. We tell
2835 * build_expression_pathkey not to build any new equivalence class; if
2836 * the Var isn't already mentioned in some EC, it means that nothing
2837 * cares about the ordering.
2838 */
2839 if (var)
2840 pathkeys = build_expression_pathkey(root,
2841 (Expr *) var,
2842 Int8LessOperator,
2843 rel->relids,
2844 false);
2845 }
2846
2847 /* Generate appropriate path */
2848 add_path(rel, create_functionscan_path(root, rel,
2849 pathkeys, required_outer));
2850}
2851
2852/*
2853 * set_values_pathlist
2854 * Build the (single) access path for a VALUES RTE
2855 */
2856static void
2857set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2858{
2859 Relids required_outer;
2860
2861 /*
2862 * We don't support pushing join clauses into the quals of a values scan,
2863 * but it could still have required parameterization due to LATERAL refs
2864 * in the values expressions.
2865 */
2866 required_outer = rel->lateral_relids;
2867
2868 /* Generate appropriate path */
2869 add_path(rel, create_valuesscan_path(root, rel, required_outer));
2870}
2871
2872/*
2873 * set_tablefunc_pathlist
2874 * Build the (single) access path for a table func RTE
2875 */
2876static void
2877set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2878{
2879 Relids required_outer;
2880
2881 /*
2882 * We don't support pushing join clauses into the quals of a tablefunc
2883 * scan, but it could still have required parameterization due to LATERAL
2884 * refs in the function expression.
2885 */
2886 required_outer = rel->lateral_relids;
2887
2888 /* Generate appropriate path */
2889 add_path(rel, create_tablefuncscan_path(root, rel,
2890 required_outer));
2891}
2892
2893/*
2894 * set_cte_pathlist
2895 * Build the (single) access path for a non-self-reference CTE RTE
2896 *
2897 * There's no need for a separate set_cte_size phase, since we don't
2898 * support join-qual-parameterized paths for CTEs.
2899 */
2900static void
2901set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
2902{
2903 Path *ctepath;
2904 Plan *cteplan;
2905 PlannerInfo *cteroot;
2906 Index levelsup;
2907 List *pathkeys;
2908 int ndx;
2909 ListCell *lc;
2910 int plan_id;
2911 Relids required_outer;
2912
2913 /*
2914 * Find the referenced CTE, and locate the path and plan previously made
2915 * for it.
2916 */
2917 levelsup = rte->ctelevelsup;
2918 cteroot = root;
2919 while (levelsup-- > 0)
2920 {
2921 cteroot = cteroot->parent_root;
2922 if (!cteroot) /* shouldn't happen */
2923 elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
2924 }
2925
2926 /*
2927 * Note: cte_plan_ids can be shorter than cteList, if we are still working
2928 * on planning the CTEs (ie, this is a side-reference from another CTE).
2929 * So we mustn't use forboth here.
2930 */
2931 ndx = 0;
2932 foreach(lc, cteroot->parse->cteList)
2933 {
2934 CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
2935
2936 if (strcmp(cte->ctename, rte->ctename) == 0)
2937 break;
2938 ndx++;
2939 }
2940 if (lc == NULL) /* shouldn't happen */
2941 elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
2942 if (ndx >= list_length(cteroot->cte_plan_ids))
2943 elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
2944 plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
2945 if (plan_id <= 0)
2946 elog(ERROR, "no plan was made for CTE \"%s\"", rte->ctename);
2947
2948 Assert(list_length(root->glob->subpaths) == list_length(root->glob->subplans));
2949 ctepath = (Path *) list_nth(root->glob->subpaths, plan_id - 1);
2950 cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1);
2951
2952 /* Mark rel with estimated output rows, width, etc */
2953 set_cte_size_estimates(root, rel, cteplan->plan_rows);
2954
2955 /* Convert the ctepath's pathkeys to outer query's representation */
2956 pathkeys = convert_subquery_pathkeys(root,
2957 rel,
2958 ctepath->pathkeys,
2959 cteplan->targetlist);
2960
2961 /*
2962 * We don't support pushing join clauses into the quals of a CTE scan, but
2963 * it could still have required parameterization due to LATERAL refs in
2964 * its tlist.
2965 */
2966 required_outer = rel->lateral_relids;
2967
2968 /* Generate appropriate path */
2969 add_path(rel, create_ctescan_path(root, rel, pathkeys, required_outer));
2970}
2971
2972/*
2973 * set_namedtuplestore_pathlist
2974 * Build the (single) access path for a named tuplestore RTE
2975 *
2976 * There's no need for a separate set_namedtuplestore_size phase, since we
2977 * don't support join-qual-parameterized paths for tuplestores.
2978 */
2979static void
2980set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel,
2981 RangeTblEntry *rte)
2982{
2983 Relids required_outer;
2984
2985 /* Mark rel with estimated output rows, width, etc */
2986 set_namedtuplestore_size_estimates(root, rel);
2987
2988 /*
2989 * We don't support pushing join clauses into the quals of a tuplestore
2990 * scan, but it could still have required parameterization due to LATERAL
2991 * refs in its tlist.
2992 */
2993 required_outer = rel->lateral_relids;
2994
2995 /* Generate appropriate path */
2996 add_path(rel, create_namedtuplestorescan_path(root, rel, required_outer));
2997}
2998
2999/*
3000 * set_result_pathlist
3001 * Build the (single) access path for an RTE_RESULT RTE
3002 *
3003 * There's no need for a separate set_result_size phase, since we
3004 * don't support join-qual-parameterized paths for these RTEs.
3005 */
3006static void
3007set_result_pathlist(PlannerInfo *root, RelOptInfo *rel,
3008 RangeTblEntry *rte)
3009{
3010 Relids required_outer;
3011
3012 /* Mark rel with estimated output rows, width, etc */
3013 set_result_size_estimates(root, rel);
3014
3015 /*
3016 * We don't support pushing join clauses into the quals of a Result scan,
3017 * but it could still have required parameterization due to LATERAL refs
3018 * in its tlist.
3019 */
3020 required_outer = rel->lateral_relids;
3021
3022 /* Generate appropriate path */
3023 add_path(rel, create_resultscan_path(root, rel, required_outer));
3024}
3025
3026/*
3027 * set_worktable_pathlist
3028 * Build the (single) access path for a self-reference CTE RTE
3029 *
3030 * There's no need for a separate set_worktable_size phase, since we don't
3031 * support join-qual-parameterized paths for CTEs.
3032 */
3033static void
3034set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
3035{
3036 Path *ctepath;
3037 PlannerInfo *cteroot;
3038 Index levelsup;
3039 Relids required_outer;
3040
3041 /*
3042 * We need to find the non-recursive term's path, which is in the plan
3043 * level that's processing the recursive UNION, which is one level *below*
3044 * where the CTE comes from.
3045 */
3046 levelsup = rte->ctelevelsup;
3047 if (levelsup == 0) /* shouldn't happen */
3048 elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
3049 levelsup--;
3050 cteroot = root;
3051 while (levelsup-- > 0)
3052 {
3053 cteroot = cteroot->parent_root;
3054 if (!cteroot) /* shouldn't happen */
3055 elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
3056 }
3057 ctepath = cteroot->non_recursive_path;
3058 if (!ctepath) /* shouldn't happen */
3059 elog(ERROR, "could not find path for CTE \"%s\"", rte->ctename);
3060
3061 /* Mark rel with estimated output rows, width, etc */
3062 set_cte_size_estimates(root, rel, ctepath->rows);
3063
3064 /*
3065 * We don't support pushing join clauses into the quals of a worktable
3066 * scan, but it could still have required parameterization due to LATERAL
3067 * refs in its tlist. (I'm not sure this is actually possible given the
3068 * restrictions on recursive references, but it's easy enough to support.)
3069 */
3070 required_outer = rel->lateral_relids;
3071
3072 /* Generate appropriate path */
3073 add_path(rel, create_worktablescan_path(root, rel, required_outer));
3074}
3075
3076/*
3077 * generate_gather_paths
3078 * Generate parallel access paths for a relation by pushing a Gather or
3079 * Gather Merge on top of a partial path.
3080 *
3081 * This must not be called until after we're done creating all partial paths
3082 * for the specified relation. (Otherwise, add_partial_path might delete a
3083 * path that some GatherPath or GatherMergePath has a reference to.)
3084 *
3085 * If we're generating paths for a scan or join relation, override_rows will
3086 * be false, and we'll just use the relation's size estimate. When we're
3087 * being called for a partially-grouped or partially-distinct path, though, we
3088 * need to override the rowcount estimate. (It's not clear that the
3089 * particular value we're using here is actually best, but the underlying rel
3090 * has no estimate so we must do something.)
3091 */
3092void
3093generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
3094{
3095 Path *cheapest_partial_path;
3096 Path *simple_gather_path;
3097 ListCell *lc;
3098 double rows;
3099 double *rowsp = NULL;
3100
3101 /* If there are no partial paths, there's nothing to do here. */
3102 if (rel->partial_pathlist == NIL)
3103 return;
3104
3105 /* Should we override the rel's rowcount estimate? */
3106 if (override_rows)
3107 rowsp = &rows;
3108
3109 /*
3110 * The output of Gather is always unsorted, so there's only one partial
3111 * path of interest: the cheapest one. That will be the one at the front
3112 * of partial_pathlist because of the way add_partial_path works.
3113 */
3114 cheapest_partial_path = linitial(rel->partial_pathlist);
3115 rows = compute_gather_rows(cheapest_partial_path);
3116 simple_gather_path = (Path *)
3117 create_gather_path(root, rel, cheapest_partial_path, rel->reltarget,
3118 NULL, rowsp);
3119 add_path(rel, simple_gather_path);
3120
3121 /*
3122 * For each useful ordering, we can consider an order-preserving Gather
3123 * Merge.
3124 */
3125 foreach(lc, rel->partial_pathlist)
3126 {
3127 Path *subpath = (Path *) lfirst(lc);
3128 GatherMergePath *path;
3129
3130 if (subpath->pathkeys == NIL)
3131 continue;
3132
3133 rows = compute_gather_rows(subpath);
3134 path = create_gather_merge_path(root, rel, subpath, rel->reltarget,
3135 subpath->pathkeys, NULL, rowsp);
3136 add_path(rel, &path->path);
3137 }
3138}
3139
3140/*
3141 * get_useful_pathkeys_for_relation
3142 * Determine which orderings of a relation might be useful.
3143 *
3144 * Getting data in sorted order can be useful either because the requested
3145 * order matches the final output ordering for the overall query we're
3146 * planning, or because it enables an efficient merge join. Here, we try
3147 * to figure out which pathkeys to consider.
3148 *
3149 * This allows us to do incremental sort on top of an index scan under a gather
3150 * merge node, i.e. parallelized.
3151 *
3152 * If the require_parallel_safe is true, we also require the expressions to
3153 * be parallel safe (which allows pushing the sort below Gather Merge).
3154 *
3155 * XXX At the moment this can only ever return a list with a single element,
3156 * because it looks at query_pathkeys only. So we might return the pathkeys
3157 * directly, but it seems plausible we'll want to consider other orderings
3158 * in the future. For example, we might want to consider pathkeys useful for
3159 * merge joins.
3160 */
3161static List *
3162get_useful_pathkeys_for_relation(PlannerInfo *root, RelOptInfo *rel,
3163 bool require_parallel_safe)
3164{
3165 List *useful_pathkeys_list = NIL;
3166
3167 /*
3168 * Considering query_pathkeys is always worth it, because it might allow
3169 * us to avoid a total sort when we have a partially presorted path
3170 * available or to push the total sort into the parallel portion of the
3171 * query.
3172 */
3173 if (root->query_pathkeys)
3174 {
3175 ListCell *lc;
3176 int npathkeys = 0; /* useful pathkeys */
3177
3178 foreach(lc, root->query_pathkeys)
3179 {
3180 PathKey *pathkey = (PathKey *) lfirst(lc);
3181 EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
3182
3183 /*
3184 * We can only build a sort for pathkeys that contain a
3185 * safe-to-compute-early EC member computable from the current
3186 * relation's reltarget, so ignore the remainder of the list as
3187 * soon as we find a pathkey without such a member.
3188 *
3189 * It's still worthwhile to return any prefix of the pathkeys list
3190 * that meets this requirement, as we may be able to do an
3191 * incremental sort.
3192 *
3193 * If requested, ensure the sort expression is parallel-safe too.
3194 */
3195 if (!relation_can_be_sorted_early(root, rel, pathkey_ec,
3196 require_parallel_safe))
3197 break;
3198
3199 npathkeys++;
3200 }
3201
3202 /*
3203 * The whole query_pathkeys list matches, so append it directly, to
3204 * allow comparing pathkeys easily by comparing list pointer. If we
3205 * have to truncate the pathkeys, we gotta do a copy though.
3206 */
3207 if (npathkeys == list_length(root->query_pathkeys))
3208 useful_pathkeys_list = lappend(useful_pathkeys_list,
3209 root->query_pathkeys);
3210 else if (npathkeys > 0)
3211 useful_pathkeys_list = lappend(useful_pathkeys_list,
3212 list_copy_head(root->query_pathkeys,
3213 npathkeys));
3214 }
3215
3216 return useful_pathkeys_list;
3217}
3218
3219/*
3220 * generate_useful_gather_paths
3221 * Generate parallel access paths for a relation by pushing a Gather or
3222 * Gather Merge on top of a partial path.
3223 *
3224 * Unlike plain generate_gather_paths, this looks both at pathkeys of input
3225 * paths (aiming to preserve the ordering), but also considers ordering that
3226 * might be useful for nodes above the gather merge node, and tries to add
3227 * a sort (regular or incremental) to provide that.
3228 */
3229void
3230generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
3231{
3232 ListCell *lc;
3233 double rows;
3234 double *rowsp = NULL;
3235 List *useful_pathkeys_list = NIL;
3236 Path *cheapest_partial_path = NULL;
3237
3238 /* If there are no partial paths, there's nothing to do here. */
3239 if (rel->partial_pathlist == NIL)
3240 return;
3241
3242 /* Should we override the rel's rowcount estimate? */
3243 if (override_rows)
3244 rowsp = &rows;
3245
3246 /* generate the regular gather (merge) paths */
3247 generate_gather_paths(root, rel, override_rows);
3248
3249 /* consider incremental sort for interesting orderings */
3250 useful_pathkeys_list = get_useful_pathkeys_for_relation(root, rel, true);
3251
3252 /* used for explicit (full) sort paths */
3253 cheapest_partial_path = linitial(rel->partial_pathlist);
3254
3255 /*
3256 * Consider sorted paths for each interesting ordering. We generate both
3257 * incremental and full sort.
3258 */
3259 foreach(lc, useful_pathkeys_list)
3260 {
3261 List *useful_pathkeys = lfirst(lc);
3262 ListCell *lc2;
3263 bool is_sorted;
3264 int presorted_keys;
3265
3266 foreach(lc2, rel->partial_pathlist)
3267 {
3268 Path *subpath = (Path *) lfirst(lc2);
3269 GatherMergePath *path;
3270
3271 is_sorted = pathkeys_count_contained_in(useful_pathkeys,
3272 subpath->pathkeys,
3273 &presorted_keys);
3274
3275 /*
3276 * We don't need to consider the case where a subpath is already
3277 * fully sorted because generate_gather_paths already creates a
3278 * gather merge path for every subpath that has pathkeys present.
3279 *
3280 * But since the subpath is already sorted, we know we don't need
3281 * to consider adding a sort (full or incremental) on top of it,
3282 * so we can continue here.
3283 */
3284 if (is_sorted)
3285 continue;
3286
3287 /*
3288 * Try at least sorting the cheapest path and also try
3289 * incrementally sorting any path which is partially sorted
3290 * already (no need to deal with paths which have presorted keys
3291 * when incremental sort is disabled unless it's the cheapest
3292 * input path).
3293 */
3294 if (subpath != cheapest_partial_path &&
3295 (presorted_keys == 0 || !enable_incremental_sort))
3296 continue;
3297
3298 /*
3299 * Consider regular sort for any path that's not presorted or if
3300 * incremental sort is disabled. We've no need to consider both
3301 * sort and incremental sort on the same path. We assume that
3302 * incremental sort is always faster when there are presorted
3303 * keys.
3304 *
3305 * This is not redundant with the gather paths created in
3306 * generate_gather_paths, because that doesn't generate ordered
3307 * output. Here we add an explicit sort to match the useful
3308 * ordering.
3309 */
3310 if (presorted_keys == 0 || !enable_incremental_sort)
3311 {
3312 subpath = (Path *) create_sort_path(root,
3313 rel,
3314 subpath,
3315 useful_pathkeys,
3316 -1.0);
3317 }
3318 else
3319 subpath = (Path *) create_incremental_sort_path(root,
3320 rel,
3321 subpath,
3322 useful_pathkeys,
3323 presorted_keys,
3324 -1);
3325 rows = compute_gather_rows(subpath);
3326 path = create_gather_merge_path(root, rel,
3327 subpath,
3328 rel->reltarget,
3329 subpath->pathkeys,
3330 NULL,
3331 rowsp);
3332
3333 add_path(rel, &path->path);
3334 }
3335 }
3336}
3337
3338/*
3339 * make_rel_from_joinlist
3340 * Build access paths using a "joinlist" to guide the join path search.
3341 *
3342 * See comments for deconstruct_jointree() for definition of the joinlist
3343 * data structure.
3344 */
3345static RelOptInfo *
3346make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
3347{
3348 int levels_needed;
3349 List *initial_rels;
3350 ListCell *jl;
3351
3352 /*
3353 * Count the number of child joinlist nodes. This is the depth of the
3354 * dynamic-programming algorithm we must employ to consider all ways of
3355 * joining the child nodes.
3356 */
3357 levels_needed = list_length(joinlist);
3358
3359 if (levels_needed <= 0)
3360 return NULL; /* nothing to do? */
3361
3362 /*
3363 * Construct a list of rels corresponding to the child joinlist nodes.
3364 * This may contain both base rels and rels constructed according to
3365 * sub-joinlists.
3366 */
3367 initial_rels = NIL;
3368 foreach(jl, joinlist)
3369 {
3370 Node *jlnode = (Node *) lfirst(jl);
3371 RelOptInfo *thisrel;
3372
3373 if (IsA(jlnode, RangeTblRef))
3374 {
3375 int varno = ((RangeTblRef *) jlnode)->rtindex;
3376
3377 thisrel = find_base_rel(root, varno);
3378 }
3379 else if (IsA(jlnode, List))
3380 {
3381 /* Recurse to handle subproblem */
3382 thisrel = make_rel_from_joinlist(root, (List *) jlnode);
3383 }
3384 else
3385 {
3386 elog(ERROR, "unrecognized joinlist node type: %d",
3387 (int) nodeTag(jlnode));
3388 thisrel = NULL; /* keep compiler quiet */
3389 }
3390
3391 initial_rels = lappend(initial_rels, thisrel);
3392 }
3393
3394 if (levels_needed == 1)
3395 {
3396 /*
3397 * Single joinlist node, so we're done.
3398 */
3399 return (RelOptInfo *) linitial(initial_rels);
3400 }
3401 else
3402 {
3403 /*
3404 * Consider the different orders in which we could join the rels,
3405 * using a plugin, GEQO, or the regular join search code.
3406 *
3407 * We put the initial_rels list into a PlannerInfo field because
3408 * has_legal_joinclause() needs to look at it (ugly :-().
3409 */
3410 root->initial_rels = initial_rels;
3411
3412 if (join_search_hook)
3413 return (*join_search_hook) (root, levels_needed, initial_rels);
3414 else if (enable_geqo && levels_needed >= geqo_threshold)
3415 return geqo(root, levels_needed, initial_rels);
3416 else
3417 return standard_join_search(root, levels_needed, initial_rels);
3418 }
3419}
3420
3421/*
3422 * standard_join_search
3423 * Find possible joinpaths for a query by successively finding ways
3424 * to join component relations into join relations.
3425 *
3426 * 'levels_needed' is the number of iterations needed, ie, the number of
3427 * independent jointree items in the query. This is > 1.
3428 *
3429 * 'initial_rels' is a list of RelOptInfo nodes for each independent
3430 * jointree item. These are the components to be joined together.
3431 * Note that levels_needed == list_length(initial_rels).
3432 *
3433 * Returns the final level of join relations, i.e., the relation that is
3434 * the result of joining all the original relations together.
3435 * At least one implementation path must be provided for this relation and
3436 * all required sub-relations.
3437 *
3438 * To support loadable plugins that modify planner behavior by changing the
3439 * join searching algorithm, we provide a hook variable that lets a plugin
3440 * replace or supplement this function. Any such hook must return the same
3441 * final join relation as the standard code would, but it might have a
3442 * different set of implementation paths attached, and only the sub-joinrels
3443 * needed for these paths need have been instantiated.
3444 *
3445 * Note to plugin authors: the functions invoked during standard_join_search()
3446 * modify root->join_rel_list and root->join_rel_hash. If you want to do more
3447 * than one join-order search, you'll probably need to save and restore the
3448 * original states of those data structures. See geqo_eval() for an example.
3449 */
3450RelOptInfo *
3451standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
3452{
3453 int lev;
3454 RelOptInfo *rel;
3455
3456 /*
3457 * This function cannot be invoked recursively within any one planning
3458 * problem, so join_rel_level[] can't be in use already.
3459 */
3460 Assert(root->join_rel_level == NULL);
3461
3462 /*
3463 * We employ a simple "dynamic programming" algorithm: we first find all
3464 * ways to build joins of two jointree items, then all ways to build joins
3465 * of three items (from two-item joins and single items), then four-item
3466 * joins, and so on until we have considered all ways to join all the
3467 * items into one rel.
3468 *
3469 * root->join_rel_level[j] is a list of all the j-item rels. Initially we
3470 * set root->join_rel_level[1] to represent all the single-jointree-item
3471 * relations.
3472 */
3473 root->join_rel_level = (List **) palloc0((levels_needed + 1) * sizeof(List *));
3474
3475 root->join_rel_level[1] = initial_rels;
3476
3477 for (lev = 2; lev <= levels_needed; lev++)
3478 {
3479 ListCell *lc;
3480
3481 /*
3482 * Determine all possible pairs of relations to be joined at this
3483 * level, and build paths for making each one from every available
3484 * pair of lower-level relations.
3485 */
3486 join_search_one_level(root, lev);
3487
3488 /*
3489 * Run generate_partitionwise_join_paths() and
3490 * generate_useful_gather_paths() for each just-processed joinrel. We
3491 * could not do this earlier because both regular and partial paths
3492 * can get added to a particular joinrel at multiple times within
3493 * join_search_one_level.
3494 *
3495 * After that, we're done creating paths for the joinrel, so run
3496 * set_cheapest().
3497 */
3498 foreach(lc, root->join_rel_level[lev])
3499 {
3500 rel = (RelOptInfo *) lfirst(lc);
3501
3502 /* Create paths for partitionwise joins. */
3503 generate_partitionwise_join_paths(root, rel);
3504
3505 /*
3506 * Except for the topmost scan/join rel, consider gathering
3507 * partial paths. We'll do the same for the topmost scan/join rel
3508 * once we know the final targetlist (see grouping_planner's and
3509 * its call to apply_scanjoin_target_to_paths).
3510 */
3511 if (!bms_equal(rel->relids, root->all_query_rels))
3512 generate_useful_gather_paths(root, rel, false);
3513
3514 /* Find and save the cheapest paths for this rel */
3515 set_cheapest(rel);
3516
3517#ifdef OPTIMIZER_DEBUG
3518 pprint(rel);
3519#endif
3520 }
3521 }
3522
3523 /*
3524 * We should have a single rel at the final level.
3525 */
3526 if (root->join_rel_level[levels_needed] == NIL)
3527 elog(ERROR, "failed to build any %d-way joins", levels_needed);
3528 Assert(list_length(root->join_rel_level[levels_needed]) == 1);
3529
3530 rel = (RelOptInfo *) linitial(root->join_rel_level[levels_needed]);
3531
3532 root->join_rel_level = NULL;
3533
3534 return rel;
3535}
3536
3537/*****************************************************************************
3538 * PUSHING QUALS DOWN INTO SUBQUERIES
3539 *****************************************************************************/
3540
3541/*
3542 * subquery_is_pushdown_safe - is a subquery safe for pushing down quals?
3543 *
3544 * subquery is the particular component query being checked. topquery
3545 * is the top component of a set-operations tree (the same Query if no
3546 * set-op is involved).
3547 *
3548 * Conditions checked here:
3549 *
3550 * 1. If the subquery has a LIMIT clause, we must not push down any quals,
3551 * since that could change the set of rows returned.
3552 *
3553 * 2. If the subquery contains EXCEPT or EXCEPT ALL set ops we cannot push
3554 * quals into it, because that could change the results.
3555 *
3556 * 3. If the subquery uses DISTINCT, we cannot push volatile quals into it.
3557 * This is because upper-level quals should semantically be evaluated only
3558 * once per distinct row, not once per original row, and if the qual is
3559 * volatile then extra evaluations could change the results. (This issue
3560 * does not apply to other forms of aggregation such as GROUP BY, because
3561 * when those are present we push into HAVING not WHERE, so that the quals
3562 * are still applied after aggregation.)
3563 *
3564 * 4. If the subquery contains window functions, we cannot push volatile quals
3565 * into it. The issue here is a bit different from DISTINCT: a volatile qual
3566 * might succeed for some rows of a window partition and fail for others,
3567 * thereby changing the partition contents and thus the window functions'
3568 * results for rows that remain.
3569 *
3570 * 5. If the subquery contains any set-returning functions in its targetlist,
3571 * we cannot push volatile quals into it. That would push them below the SRFs
3572 * and thereby change the number of times they are evaluated. Also, a
3573 * volatile qual could succeed for some SRF output rows and fail for others,
3574 * a behavior that cannot occur if it's evaluated before SRF expansion.
3575 *
3576 * 6. If the subquery has nonempty grouping sets, we cannot push down any
3577 * quals. The concern here is that a qual referencing a "constant" grouping
3578 * column could get constant-folded, which would be improper because the value
3579 * is potentially nullable by grouping-set expansion. This restriction could
3580 * be removed if we had a parsetree representation that shows that such
3581 * grouping columns are not really constant. (There are other ideas that
3582 * could be used to relax this restriction, but that's the approach most
3583 * likely to get taken in the future. Note that there's not much to be gained
3584 * so long as subquery_planner can't move HAVING clauses to WHERE within such
3585 * a subquery.)
3586 *
3587 * In addition, we make several checks on the subquery's output columns to see
3588 * if it is safe to reference them in pushed-down quals. If output column k
3589 * is found to be unsafe to reference, we set the reason for that inside
3590 * safetyInfo->unsafeFlags[k], but we don't reject the subquery overall since
3591 * column k might not be referenced by some/all quals. The unsafeFlags[]
3592 * array will be consulted later by qual_is_pushdown_safe(). It's better to
3593 * do it this way than to make the checks directly in qual_is_pushdown_safe(),
3594 * because when the subquery involves set operations we have to check the
3595 * output expressions in each arm of the set op.
3596 *
3597 * Note: pushing quals into a DISTINCT subquery is theoretically dubious:
3598 * we're effectively assuming that the quals cannot distinguish values that
3599 * the DISTINCT's equality operator sees as equal, yet there are many
3600 * counterexamples to that assumption. However use of such a qual with a
3601 * DISTINCT subquery would be unsafe anyway, since there's no guarantee which
3602 * "equal" value will be chosen as the output value by the DISTINCT operation.
3603 * So we don't worry too much about that. Another objection is that if the
3604 * qual is expensive to evaluate, running it for each original row might cost
3605 * more than we save by eliminating rows before the DISTINCT step. But it
3606 * would be very hard to estimate that at this stage, and in practice pushdown
3607 * seldom seems to make things worse, so we ignore that problem too.
3608 *
3609 * Note: likewise, pushing quals into a subquery with window functions is a
3610 * bit dubious: the quals might remove some rows of a window partition while
3611 * leaving others, causing changes in the window functions' results for the
3612 * surviving rows. We insist that such a qual reference only partitioning
3613 * columns, but again that only protects us if the qual does not distinguish
3614 * values that the partitioning equality operator sees as equal. The risks
3615 * here are perhaps larger than for DISTINCT, since no de-duplication of rows
3616 * occurs and thus there is no theoretical problem with such a qual. But
3617 * we'll do this anyway because the potential performance benefits are very
3618 * large, and we've seen no field complaints about the longstanding comparable
3619 * behavior with DISTINCT.
3620 */
3621static bool
3622subquery_is_pushdown_safe(Query *subquery, Query *topquery,
3623 pushdown_safety_info *safetyInfo)
3624{
3625 SetOperationStmt *topop;
3626
3627 /* Check point 1 */
3628 if (subquery->limitOffset != NULL || subquery->limitCount != NULL)
3629 return false;
3630
3631 /* Check point 6 */
3632 if (subquery->groupClause && subquery->groupingSets)
3633 return false;
3634
3635 /* Check points 3, 4, and 5 */
3636 if (subquery->distinctClause ||
3637 subquery->hasWindowFuncs ||
3638 subquery->hasTargetSRFs)
3639 safetyInfo->unsafeVolatile = true;
3640
3641 /*
3642 * If we're at a leaf query, check for unsafe expressions in its target
3643 * list, and mark any reasons why they're unsafe in unsafeFlags[].
3644 * (Non-leaf nodes in setop trees have only simple Vars in their tlists,
3645 * so no need to check them.)
3646 */
3647 if (subquery->setOperations == NULL)
3648 check_output_expressions(subquery, safetyInfo);
3649
3650 /* Are we at top level, or looking at a setop component? */
3651 if (subquery == topquery)
3652 {
3653 /* Top level, so check any component queries */
3654 if (subquery->setOperations != NULL)
3655 if (!recurse_pushdown_safe(subquery->setOperations, topquery,
3656 safetyInfo))
3657 return false;
3658 }
3659 else
3660 {
3661 /* Setop component must not have more components (too weird) */
3662 if (subquery->setOperations != NULL)
3663 return false;
3664 /* Check whether setop component output types match top level */
3665 topop = castNode(SetOperationStmt, topquery->setOperations);
3666 Assert(topop);
3667 compare_tlist_datatypes(subquery->targetList,
3668 topop->colTypes,
3669 safetyInfo);
3670 }
3671 return true;
3672}
3673
3674/*
3675 * Helper routine to recurse through setOperations tree
3676 */
3677static bool
3678recurse_pushdown_safe(Node *setOp, Query *topquery,
3679 pushdown_safety_info *safetyInfo)
3680{
3681 if (IsA(setOp, RangeTblRef))
3682 {
3683 RangeTblRef *rtr = (RangeTblRef *) setOp;
3684 RangeTblEntry *rte = rt_fetch(rtr->rtindex, topquery->rtable);
3685 Query *subquery = rte->subquery;
3686
3687 Assert(subquery != NULL);
3688 return subquery_is_pushdown_safe(subquery, topquery, safetyInfo);
3689 }
3690 else if (IsA(setOp, SetOperationStmt))
3691 {
3692 SetOperationStmt *op = (SetOperationStmt *) setOp;
3693
3694 /* EXCEPT is no good (point 2 for subquery_is_pushdown_safe) */
3695 if (op->op == SETOP_EXCEPT)
3696 return false;
3697 /* Else recurse */
3698 if (!recurse_pushdown_safe(op->larg, topquery, safetyInfo))
3699 return false;
3700 if (!recurse_pushdown_safe(op->rarg, topquery, safetyInfo))
3701 return false;
3702 }
3703 else
3704 {
3705 elog(ERROR, "unrecognized node type: %d",
3706 (int) nodeTag(setOp));
3707 }
3708 return true;
3709}
3710
3711/*
3712 * check_output_expressions - check subquery's output expressions for safety
3713 *
3714 * There are several cases in which it's unsafe to push down an upper-level
3715 * qual if it references a particular output column of a subquery. We check
3716 * each output column of the subquery and set flags in unsafeFlags[k] when we
3717 * see that column is unsafe for a pushed-down qual to reference. The
3718 * conditions checked here are:
3719 *
3720 * 1. We must not push down any quals that refer to subselect outputs that
3721 * return sets, else we'd introduce functions-returning-sets into the
3722 * subquery's WHERE/HAVING quals.
3723 *
3724 * 2. We must not push down any quals that refer to subselect outputs that
3725 * contain volatile functions, for fear of introducing strange results due
3726 * to multiple evaluation of a volatile function.
3727 *
3728 * 3. If the subquery uses DISTINCT ON, we must not push down any quals that
3729 * refer to non-DISTINCT output columns, because that could change the set
3730 * of rows returned. (This condition is vacuous for DISTINCT, because then
3731 * there are no non-DISTINCT output columns, so we needn't check. Note that
3732 * subquery_is_pushdown_safe already reported that we can't use volatile
3733 * quals if there's DISTINCT or DISTINCT ON.)
3734 *
3735 * 4. If the subquery has any window functions, we must not push down quals
3736 * that reference any output columns that are not listed in all the subquery's
3737 * window PARTITION BY clauses. We can push down quals that use only
3738 * partitioning columns because they should succeed or fail identically for
3739 * every row of any one window partition, and totally excluding some
3740 * partitions will not change a window function's results for remaining
3741 * partitions. (Again, this also requires nonvolatile quals, but
3742 * subquery_is_pushdown_safe handles that.). Subquery columns marked as
3743 * unsafe for this reason can still have WindowClause run conditions pushed
3744 * down.
3745 */
3746static void
3747check_output_expressions(Query *subquery, pushdown_safety_info *safetyInfo)
3748{
3749 ListCell *lc;
3750
3751 foreach(lc, subquery->targetList)
3752 {
3753 TargetEntry *tle = (TargetEntry *) lfirst(lc);
3754
3755 if (tle->resjunk)
3756 continue; /* ignore resjunk columns */
3757
3758 /* Functions returning sets are unsafe (point 1) */
3759 if (subquery->hasTargetSRFs &&
3760 (safetyInfo->unsafeFlags[tle->resno] &
3761 UNSAFE_HAS_SET_FUNC) == 0 &&
3762 expression_returns_set((Node *) tle->expr))
3763 {
3764 safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_HAS_SET_FUNC;
3765 continue;
3766 }
3767
3768 /* Volatile functions are unsafe (point 2) */
3769 if ((safetyInfo->unsafeFlags[tle->resno] &
3770 UNSAFE_HAS_VOLATILE_FUNC) == 0 &&
3771 contain_volatile_functions((Node *) tle->expr))
3772 {
3773 safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_HAS_VOLATILE_FUNC;
3774 continue;
3775 }
3776
3777 /* If subquery uses DISTINCT ON, check point 3 */
3778 if (subquery->hasDistinctOn &&
3779 (safetyInfo->unsafeFlags[tle->resno] &
3780 UNSAFE_NOTIN_DISTINCTON_CLAUSE) == 0 &&
3781 !targetIsInSortList(tle, InvalidOid, subquery->distinctClause))
3782 {
3783 /* non-DISTINCT column, so mark it unsafe */
3784 safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_NOTIN_DISTINCTON_CLAUSE;
3785 continue;
3786 }
3787
3788 /* If subquery uses window functions, check point 4 */
3789 if (subquery->hasWindowFuncs &&
3790 (safetyInfo->unsafeFlags[tle->resno] &
3791 UNSAFE_NOTIN_DISTINCTON_CLAUSE) == 0 &&
3792 !targetIsInAllPartitionLists(tle, subquery))
3793 {
3794 /* not present in all PARTITION BY clauses, so mark it unsafe */
3795 safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_NOTIN_PARTITIONBY_CLAUSE;
3796 continue;
3797 }
3798 }
3799}
3800
3801/*
3802 * For subqueries using UNION/UNION ALL/INTERSECT/INTERSECT ALL, we can
3803 * push quals into each component query, but the quals can only reference
3804 * subquery columns that suffer no type coercions in the set operation.
3805 * Otherwise there are possible semantic gotchas. So, we check the
3806 * component queries to see if any of them have output types different from
3807 * the top-level setop outputs. We set the UNSAFE_TYPE_MISMATCH bit in
3808 * unsafeFlags[k] if column k has different type in any component.
3809 *
3810 * We don't have to care about typmods here: the only allowed difference
3811 * between set-op input and output typmods is input is a specific typmod
3812 * and output is -1, and that does not require a coercion.
3813 *
3814 * tlist is a subquery tlist.
3815 * colTypes is an OID list of the top-level setop's output column types.
3816 * safetyInfo is the pushdown_safety_info to set unsafeFlags[] for.
3817 */
3818static void
3819compare_tlist_datatypes(List *tlist, List *colTypes,
3820 pushdown_safety_info *safetyInfo)
3821{
3822 ListCell *l;
3823 ListCell *colType = list_head(colTypes);
3824
3825 foreach(l, tlist)
3826 {
3827 TargetEntry *tle = (TargetEntry *) lfirst(l);
3828
3829 if (tle->resjunk)
3830 continue; /* ignore resjunk columns */
3831 if (colType == NULL)
3832 elog(ERROR, "wrong number of tlist entries");
3833 if (exprType((Node *) tle->expr) != lfirst_oid(colType))
3834 safetyInfo->unsafeFlags[tle->resno] |= UNSAFE_TYPE_MISMATCH;
3835 colType = lnext(colTypes, colType);
3836 }
3837 if (colType != NULL)
3838 elog(ERROR, "wrong number of tlist entries");
3839}
3840
3841/*
3842 * targetIsInAllPartitionLists
3843 * True if the TargetEntry is listed in the PARTITION BY clause
3844 * of every window defined in the query.
3845 *
3846 * It would be safe to ignore windows not actually used by any window
3847 * function, but it's not easy to get that info at this stage; and it's
3848 * unlikely to be useful to spend any extra cycles getting it, since
3849 * unreferenced window definitions are probably infrequent in practice.
3850 */
3851static bool
3852targetIsInAllPartitionLists(TargetEntry *tle, Query *query)
3853{
3854 ListCell *lc;
3855
3856 foreach(lc, query->windowClause)
3857 {
3858 WindowClause *wc = (WindowClause *) lfirst(lc);
3859
3860 if (!targetIsInSortList(tle, InvalidOid, wc->partitionClause))
3861 return false;
3862 }
3863 return true;
3864}
3865
3866/*
3867 * qual_is_pushdown_safe - is a particular rinfo safe to push down?
3868 *
3869 * rinfo is a restriction clause applying to the given subquery (whose RTE
3870 * has index rti in the parent query).
3871 *
3872 * Conditions checked here:
3873 *
3874 * 1. rinfo's clause must not contain any SubPlans (mainly because it's
3875 * unclear that it will work correctly: SubLinks will already have been
3876 * transformed into SubPlans in the qual, but not in the subquery). Note that
3877 * SubLinks that transform to initplans are safe, and will be accepted here
3878 * because what we'll see in the qual is just a Param referencing the initplan
3879 * output.
3880 *
3881 * 2. If unsafeVolatile is set, rinfo's clause must not contain any volatile
3882 * functions.
3883 *
3884 * 3. If unsafeLeaky is set, rinfo's clause must not contain any leaky
3885 * functions that are passed Var nodes, and therefore might reveal values from
3886 * the subquery as side effects.
3887 *
3888 * 4. rinfo's clause must not refer to the whole-row output of the subquery
3889 * (since there is no easy way to name that within the subquery itself).
3890 *
3891 * 5. rinfo's clause must not refer to any subquery output columns that were
3892 * found to be unsafe to reference by subquery_is_pushdown_safe().
3893 */
3894static pushdown_safe_type
3895qual_is_pushdown_safe(Query *subquery, Index rti, RestrictInfo *rinfo,
3896 pushdown_safety_info *safetyInfo)
3897{
3898 pushdown_safe_type safe = PUSHDOWN_SAFE;
3899 Node *qual = (Node *) rinfo->clause;
3900 List *vars;
3901 ListCell *vl;
3902
3903 /* Refuse subselects (point 1) */
3904 if (contain_subplans(qual))
3905 return PUSHDOWN_UNSAFE;
3906
3907 /* Refuse volatile quals if we found they'd be unsafe (point 2) */
3908 if (safetyInfo->unsafeVolatile &&
3909 contain_volatile_functions((Node *) rinfo))
3910 return PUSHDOWN_UNSAFE;
3911
3912 /* Refuse leaky quals if told to (point 3) */
3913 if (safetyInfo->unsafeLeaky &&
3914 contain_leaked_vars(qual))
3915 return PUSHDOWN_UNSAFE;
3916
3917 /*
3918 * Examine all Vars used in clause. Since it's a restriction clause, all
3919 * such Vars must refer to subselect output columns ... unless this is
3920 * part of a LATERAL subquery, in which case there could be lateral
3921 * references.
3922 *
3923 * By omitting the relevant flags, this also gives us a cheap sanity check
3924 * that no aggregates or window functions appear in the qual. Those would
3925 * be unsafe to push down, but at least for the moment we could never see
3926 * any in a qual anyhow.
3927 */
3928 vars = pull_var_clause(qual, PVC_INCLUDE_PLACEHOLDERS);
3929 foreach(vl, vars)
3930 {
3931 Var *var = (Var *) lfirst(vl);
3932
3933 /*
3934 * XXX Punt if we find any PlaceHolderVars in the restriction clause.
3935 * It's not clear whether a PHV could safely be pushed down, and even
3936 * less clear whether such a situation could arise in any cases of
3937 * practical interest anyway. So for the moment, just refuse to push
3938 * down.
3939 */
3940 if (!IsA(var, Var))
3941 {
3942 safe = PUSHDOWN_UNSAFE;
3943 break;
3944 }
3945
3946 /*
3947 * Punt if we find any lateral references. It would be safe to push
3948 * these down, but we'd have to convert them into outer references,
3949 * which subquery_push_qual lacks the infrastructure to do. The case
3950 * arises so seldom that it doesn't seem worth working hard on.
3951 */
3952 if (var->varno != rti)
3953 {
3954 safe = PUSHDOWN_UNSAFE;
3955 break;
3956 }
3957
3958 /* Subqueries have no system columns */
3959 Assert(var->varattno >= 0);
3960
3961 /* Check point 4 */
3962 if (var->varattno == 0)
3963 {
3964 safe = PUSHDOWN_UNSAFE;
3965 break;
3966 }
3967
3968 /* Check point 5 */
3969 if (safetyInfo->unsafeFlags[var->varattno] != 0)
3970 {
3971 if (safetyInfo->unsafeFlags[var->varattno] &
3972 (UNSAFE_HAS_VOLATILE_FUNC | UNSAFE_HAS_SET_FUNC |
3973 UNSAFE_NOTIN_DISTINCTON_CLAUSE | UNSAFE_TYPE_MISMATCH))
3974 {
3975 safe = PUSHDOWN_UNSAFE;
3976 break;
3977 }
3978 else
3979 {
3980 /* UNSAFE_NOTIN_PARTITIONBY_CLAUSE is ok for run conditions */
3981 safe = PUSHDOWN_WINDOWCLAUSE_RUNCOND;
3982 /* don't break, we might find another Var that's unsafe */
3983 }
3984 }
3985 }
3986
3987 list_free(vars);
3988
3989 return safe;
3990}
3991
3992/*
3993 * subquery_push_qual - push down a qual that we have determined is safe
3994 */
3995static void
3996subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
3997{
3998 if (subquery->setOperations != NULL)
3999 {
4000 /* Recurse to push it separately to each component query */
4001 recurse_push_qual(subquery->setOperations, subquery,
4002 rte, rti, qual);
4003 }
4004 else
4005 {
4006 /*
4007 * We need to replace Vars in the qual (which must refer to outputs of
4008 * the subquery) with copies of the subquery's targetlist expressions.
4009 * Note that at this point, any uplevel Vars in the qual should have
4010 * been replaced with Params, so they need no work.
4011 *
4012 * This step also ensures that when we are pushing into a setop tree,
4013 * each component query gets its own copy of the qual.
4014 */
4015 qual = ReplaceVarsFromTargetList(qual, rti, 0, rte,
4016 subquery->targetList,
4017 subquery->resultRelation,
4018 REPLACEVARS_REPORT_ERROR, 0,
4019 &subquery->hasSubLinks);
4020
4021 /*
4022 * Now attach the qual to the proper place: normally WHERE, but if the
4023 * subquery uses grouping or aggregation, put it in HAVING (since the
4024 * qual really refers to the group-result rows).
4025 */
4026 if (subquery->hasAggs || subquery->groupClause || subquery->groupingSets || subquery->havingQual)
4027 subquery->havingQual = make_and_qual(subquery->havingQual, qual);
4028 else
4029 subquery->jointree->quals =
4030 make_and_qual(subquery->jointree->quals, qual);
4031
4032 /*
4033 * We need not change the subquery's hasAggs or hasSubLinks flags,
4034 * since we can't be pushing down any aggregates that weren't there
4035 * before, and we don't push down subselects at all.
4036 */
4037 }
4038}
4039
4040/*
4041 * Helper routine to recurse through setOperations tree
4042 */
4043static void
4044recurse_push_qual(Node *setOp, Query *topquery,
4045 RangeTblEntry *rte, Index rti, Node *qual)
4046{
4047 if (IsA(setOp, RangeTblRef))
4048 {
4049 RangeTblRef *rtr = (RangeTblRef *) setOp;
4050 RangeTblEntry *subrte = rt_fetch(rtr->rtindex, topquery->rtable);
4051 Query *subquery = subrte->subquery;
4052
4053 Assert(subquery != NULL);
4054 subquery_push_qual(subquery, rte, rti, qual);
4055 }
4056 else if (IsA(setOp, SetOperationStmt))
4057 {
4058 SetOperationStmt *op = (SetOperationStmt *) setOp;
4059
4060 recurse_push_qual(op->larg, topquery, rte, rti, qual);
4061 recurse_push_qual(op->rarg, topquery, rte, rti, qual);
4062 }
4063 else
4064 {
4065 elog(ERROR, "unrecognized node type: %d",
4066 (int) nodeTag(setOp));
4067 }
4068}
4069
4070/*****************************************************************************
4071 * SIMPLIFYING SUBQUERY TARGETLISTS
4072 *****************************************************************************/
4073
4074/*
4075 * remove_unused_subquery_outputs
4076 * Remove subquery targetlist items we don't need
4077 *
4078 * It's possible, even likely, that the upper query does not read all the
4079 * output columns of the subquery. We can remove any such outputs that are
4080 * not needed by the subquery itself (e.g., as sort/group columns) and do not
4081 * affect semantics otherwise (e.g., volatile functions can't be removed).
4082 * This is useful not only because we might be able to remove expensive-to-
4083 * compute expressions, but because deletion of output columns might allow
4084 * optimizations such as join removal to occur within the subquery.
4085 *
4086 * extra_used_attrs can be passed as non-NULL to mark any columns (offset by
4087 * FirstLowInvalidHeapAttributeNumber) that we should not remove. This
4088 * parameter is modified by the function, so callers must make a copy if they
4089 * need to use the passed in Bitmapset after calling this function.
4090 *
4091 * To avoid affecting column numbering in the targetlist, we don't physically
4092 * remove unused tlist entries, but rather replace their expressions with NULL
4093 * constants. This is implemented by modifying subquery->targetList.
4094 */
4095static void
4096remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel,
4097 Bitmapset *extra_used_attrs)
4098{
4099 Bitmapset *attrs_used;
4100 ListCell *lc;
4101
4102 /*
4103 * Just point directly to extra_used_attrs. No need to bms_copy as none of
4104 * the current callers use the Bitmapset after calling this function.
4105 */
4106 attrs_used = extra_used_attrs;
4107
4108 /*
4109 * Do nothing if subquery has UNION/INTERSECT/EXCEPT: in principle we
4110 * could update all the child SELECTs' tlists, but it seems not worth the
4111 * trouble presently.
4112 */
4113 if (subquery->setOperations)
4114 return;
4115
4116 /*
4117 * If subquery has regular DISTINCT (not DISTINCT ON), we're wasting our
4118 * time: all its output columns must be used in the distinctClause.
4119 */
4120 if (subquery->distinctClause && !subquery->hasDistinctOn)
4121 return;
4122
4123 /*
4124 * Collect a bitmap of all the output column numbers used by the upper
4125 * query.
4126 *
4127 * Add all the attributes needed for joins or final output. Note: we must
4128 * look at rel's targetlist, not the attr_needed data, because attr_needed
4129 * isn't computed for inheritance child rels, cf set_append_rel_size().
4130 * (XXX might be worth changing that sometime.)
4131 */
4132 pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
4133
4134 /* Add all the attributes used by un-pushed-down restriction clauses. */
4135 foreach(lc, rel->baserestrictinfo)
4136 {
4137 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4138
4139 pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
4140 }
4141
4142 /*
4143 * If there's a whole-row reference to the subquery, we can't remove
4144 * anything.
4145 */
4146 if (bms_is_member(0 - FirstLowInvalidHeapAttributeNumber, attrs_used))
4147 return;
4148
4149 /*
4150 * Run through the tlist and zap entries we don't need. It's okay to
4151 * modify the tlist items in-place because set_subquery_pathlist made a
4152 * copy of the subquery.
4153 */
4154 foreach(lc, subquery->targetList)
4155 {
4156 TargetEntry *tle = (TargetEntry *) lfirst(lc);
4157 Node *texpr = (Node *) tle->expr;
4158
4159 /*
4160 * If it has a sortgroupref number, it's used in some sort/group
4161 * clause so we'd better not remove it. Also, don't remove any
4162 * resjunk columns, since their reason for being has nothing to do
4163 * with anybody reading the subquery's output. (It's likely that
4164 * resjunk columns in a sub-SELECT would always have ressortgroupref
4165 * set, but even if they don't, it seems imprudent to remove them.)
4166 */
4167 if (tle->ressortgroupref || tle->resjunk)
4168 continue;
4169
4170 /*
4171 * If it's used by the upper query, we can't remove it.
4172 */
4173 if (bms_is_member(tle->resno - FirstLowInvalidHeapAttributeNumber,
4174 attrs_used))
4175 continue;
4176
4177 /*
4178 * If it contains a set-returning function, we can't remove it since
4179 * that could change the number of rows returned by the subquery.
4180 */
4181 if (subquery->hasTargetSRFs &&
4182 expression_returns_set(texpr))
4183 continue;
4184
4185 /*
4186 * If it contains volatile functions, we daren't remove it for fear
4187 * that the user is expecting their side-effects to happen.
4188 */
4189 if (contain_volatile_functions(texpr))
4190 continue;
4191
4192 /*
4193 * OK, we don't need it. Replace the expression with a NULL constant.
4194 * Preserve the exposed type of the expression, in case something
4195 * looks at the rowtype of the subquery's result.
4196 */
4197 tle->expr = (Expr *) makeNullConst(exprType(texpr),
4198 exprTypmod(texpr),
4199 exprCollation(texpr));
4200 }
4201}
4202
4203/*
4204 * create_partial_bitmap_paths
4205 * Build partial bitmap heap path for the relation
4206 */
4207void
4208create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel,
4209 Path *bitmapqual)
4210{
4211 int parallel_workers;
4212 double pages_fetched;
4213
4214 /* Compute heap pages for bitmap heap scan */
4215 pages_fetched = compute_bitmap_pages(root, rel, bitmapqual, 1.0,
4216 NULL, NULL);
4217
4218 parallel_workers = compute_parallel_worker(rel, pages_fetched, -1,
4219 max_parallel_workers_per_gather);
4220
4221 if (parallel_workers <= 0)
4222 return;
4223
4224 add_partial_path(rel, (Path *) create_bitmap_heap_path(root, rel,
4225 bitmapqual, rel->lateral_relids, 1.0, parallel_workers));
4226}
4227
4228/*
4229 * Compute the number of parallel workers that should be used to scan a
4230 * relation. We compute the parallel workers based on the size of the heap to
4231 * be scanned and the size of the index to be scanned, then choose a minimum
4232 * of those.
4233 *
4234 * "heap_pages" is the number of pages from the table that we expect to scan, or
4235 * -1 if we don't expect to scan any.
4236 *
4237 * "index_pages" is the number of pages from the index that we expect to scan, or
4238 * -1 if we don't expect to scan any.
4239 *
4240 * "max_workers" is caller's limit on the number of workers. This typically
4241 * comes from a GUC.
4242 */
4243int
4244compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages,
4245 int max_workers)
4246{
4247 int parallel_workers = 0;
4248
4249 /*
4250 * If the user has set the parallel_workers reloption, use that; otherwise
4251 * select a default number of workers.
4252 */
4253 if (rel->rel_parallel_workers != -1)
4254 parallel_workers = rel->rel_parallel_workers;
4255 else
4256 {
4257 /*
4258 * If the number of pages being scanned is insufficient to justify a
4259 * parallel scan, just return zero ... unless it's an inheritance
4260 * child. In that case, we want to generate a parallel path here
4261 * anyway. It might not be worthwhile just for this relation, but
4262 * when combined with all of its inheritance siblings it may well pay
4263 * off.
4264 */
4265 if (rel->reloptkind == RELOPT_BASEREL &&
4266 ((heap_pages >= 0 && heap_pages < min_parallel_table_scan_size) ||
4267 (index_pages >= 0 && index_pages < min_parallel_index_scan_size)))
4268 return 0;
4269
4270 if (heap_pages >= 0)
4271 {
4272 int heap_parallel_threshold;
4273 int heap_parallel_workers = 1;
4274
4275 /*
4276 * Select the number of workers based on the log of the size of
4277 * the relation. This probably needs to be a good deal more
4278 * sophisticated, but we need something here for now. Note that
4279 * the upper limit of the min_parallel_table_scan_size GUC is
4280 * chosen to prevent overflow here.
4281 */
4282 heap_parallel_threshold = Max(min_parallel_table_scan_size, 1);
4283 while (heap_pages >= (BlockNumber) (heap_parallel_threshold * 3))
4284 {
4285 heap_parallel_workers++;
4286 heap_parallel_threshold *= 3;
4287 if (heap_parallel_threshold > INT_MAX / 3)
4288 break; /* avoid overflow */
4289 }
4290
4291 parallel_workers = heap_parallel_workers;
4292 }
4293
4294 if (index_pages >= 0)
4295 {
4296 int index_parallel_workers = 1;
4297 int index_parallel_threshold;
4298
4299 /* same calculation as for heap_pages above */
4300 index_parallel_threshold = Max(min_parallel_index_scan_size, 1);
4301 while (index_pages >= (BlockNumber) (index_parallel_threshold * 3))
4302 {
4303 index_parallel_workers++;
4304 index_parallel_threshold *= 3;
4305 if (index_parallel_threshold > INT_MAX / 3)
4306 break; /* avoid overflow */
4307 }
4308
4309 if (parallel_workers > 0)
4310 parallel_workers = Min(parallel_workers, index_parallel_workers);
4311 else
4312 parallel_workers = index_parallel_workers;
4313 }
4314 }
4315
4316 /* In no case use more than caller supplied maximum number of workers */
4317 parallel_workers = Min(parallel_workers, max_workers);
4318
4319 return parallel_workers;
4320}
4321
4322/*
4323 * generate_partitionwise_join_paths
4324 * Create paths representing partitionwise join for given partitioned
4325 * join relation.
4326 *
4327 * This must not be called until after we are done adding paths for all
4328 * child-joins. Otherwise, add_path might delete a path to which some path
4329 * generated here has a reference.
4330 */
4331void
4332generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
4333{
4334 List *live_children = NIL;
4335 int cnt_parts;
4336 int num_parts;
4337 RelOptInfo **part_rels;
4338
4339 /* Handle only join relations here. */
4340 if (!IS_JOIN_REL(rel))
4341 return;
4342
4343 /* We've nothing to do if the relation is not partitioned. */
4344 if (!IS_PARTITIONED_REL(rel))
4345 return;
4346
4347 /* The relation should have consider_partitionwise_join set. */
4348 Assert(rel->consider_partitionwise_join);
4349
4350 /* Guard against stack overflow due to overly deep partition hierarchy. */
4351 check_stack_depth();
4352
4353 num_parts = rel->nparts;
4354 part_rels = rel->part_rels;
4355
4356 /* Collect non-dummy child-joins. */
4357 for (cnt_parts = 0; cnt_parts < num_parts; cnt_parts++)
4358 {
4359 RelOptInfo *child_rel = part_rels[cnt_parts];
4360
4361 /* If it's been pruned entirely, it's certainly dummy. */
4362 if (child_rel == NULL)
4363 continue;
4364
4365 /* Make partitionwise join paths for this partitioned child-join. */
4366 generate_partitionwise_join_paths(root, child_rel);
4367
4368 /* If we failed to make any path for this child, we must give up. */
4369 if (child_rel->pathlist == NIL)
4370 {
4371 /*
4372 * Mark the parent joinrel as unpartitioned so that later
4373 * functions treat it correctly.
4374 */
4375 rel->nparts = 0;
4376 return;
4377 }
4378
4379 /* Else, identify the cheapest path for it. */
4380 set_cheapest(child_rel);
4381
4382 /* Dummy children need not be scanned, so ignore those. */
4383 if (IS_DUMMY_REL(child_rel))
4384 continue;
4385
4386#ifdef OPTIMIZER_DEBUG
4387 pprint(child_rel);
4388#endif
4389
4390 live_children = lappend(live_children, child_rel);
4391 }
4392
4393 /* If all child-joins are dummy, parent join is also dummy. */
4394 if (!live_children)
4395 {
4396 mark_dummy_rel(rel);
4397 return;
4398 }
4399
4400 /* Build additional paths for this rel from child-join paths. */
4401 add_paths_to_append_rel(root, rel, live_children);
4402 list_free(live_children);
4403}
set_base_rel_sizes
static void set_base_rel_sizes(PlannerInfo *root)
Definition: allpaths.c:290
get_useful_pathkeys_for_relation
static List * get_useful_pathkeys_for_relation(PlannerInfo *root, RelOptInfo *rel, bool require_parallel_safe)
Definition: allpaths.c:3162
set_subquery_pathlist
static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:2523
find_window_run_conditions
static bool find_window_run_conditions(Query *subquery, RangeTblEntry *rte, Index rti, AttrNumber attno, WindowFunc *wfunc, OpExpr *opexpr, bool wfunc_left, bool *keep_original, Bitmapset **run_cond_attrs)
Definition: allpaths.c:2257
UNSAFE_TYPE_MISMATCH
#define UNSAFE_TYPE_MISMATCH
Definition: allpaths.c:57
get_cheapest_parameterized_child_path
static Path * get_cheapest_parameterized_child_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: allpaths.c:2042
set_namedtuplestore_pathlist
static void set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2980
subquery_push_qual
static void subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:3996
generate_partitionwise_join_paths
void generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:4332
set_base_rel_consider_startup
static void set_base_rel_consider_startup(PlannerInfo *root)
Definition: allpaths.c:247
UNSAFE_HAS_VOLATILE_FUNC
#define UNSAFE_HAS_VOLATILE_FUNC
Definition: allpaths.c:53
UNSAFE_NOTIN_DISTINCTON_CLAUSE
#define UNSAFE_NOTIN_DISTINCTON_CLAUSE
Definition: allpaths.c:55
set_rel_pathlist
static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:469
get_singleton_append_subpath
static Path * get_singleton_append_subpath(Path *path)
Definition: allpaths.c:2175
set_tablesample_rel_size
static void set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:826
set_tablesample_rel_pathlist
static void set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:866
set_foreign_pathlist
static void set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:938
set_base_rel_pathlists
static void set_base_rel_pathlists(PlannerInfo *root)
Definition: allpaths.c:333
standard_join_search
RelOptInfo * standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
Definition: allpaths.c:3451
geqo_threshold
int geqo_threshold
Definition: allpaths.c:80
set_append_rel_pathlist
static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:1251
qual_is_pushdown_safe
static pushdown_safe_type qual_is_pushdown_safe(Query *subquery, Index rti, RestrictInfo *rinfo, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3895
set_result_pathlist
static void set_result_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:3007
compute_parallel_worker
int compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages, int max_workers)
Definition: allpaths.c:4244
generate_gather_paths
void generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:3093
set_dummy_rel_pathlist
static void set_dummy_rel_pathlist(RelOptInfo *rel)
Definition: allpaths.c:2209
compare_tlist_datatypes
static void compare_tlist_datatypes(List *tlist, List *colTypes, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3819
set_worktable_pathlist
static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:3034
targetIsInAllPartitionLists
static bool targetIsInAllPartitionLists(TargetEntry *tle, Query *query)
Definition: allpaths.c:3852
create_plain_partial_paths
static void create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:806
subquery_is_pushdown_safe
static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3622
join_search_hook
join_search_hook_type join_search_hook
Definition: allpaths.c:88
enable_geqo
bool enable_geqo
Definition: allpaths.c:79
check_and_push_window_quals
static bool check_and_push_window_quals(Query *subquery, RangeTblEntry *rte, Index rti, Node *clause, Bitmapset **run_cond_attrs)
Definition: allpaths.c:2448
generate_useful_gather_paths
void generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:3230
make_rel_from_joinlist
static RelOptInfo * make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
Definition: allpaths.c:3346
set_function_pathlist
static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2790
recurse_push_qual
static void recurse_push_qual(Node *setOp, Query *topquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:4044
set_plain_rel_pathlist
static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:768
remove_unused_subquery_outputs
static void remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel, Bitmapset *extra_used_attrs)
Definition: allpaths.c:4096
check_output_expressions
static void check_output_expressions(Query *subquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3747
set_tablefunc_pathlist
static void set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2877
set_foreign_size
static void set_foreign_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:914
set_rel_pathlist_hook
set_rel_pathlist_hook_type set_rel_pathlist_hook
Definition: allpaths.c:85
set_values_pathlist
static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2857
pushdown_safety_info
struct pushdown_safety_info pushdown_safety_info
make_one_rel
RelOptInfo * make_one_rel(PlannerInfo *root, List *joinlist)
Definition: allpaths.c:171
UNSAFE_HAS_SET_FUNC
#define UNSAFE_HAS_SET_FUNC
Definition: allpaths.c:54
set_cte_pathlist
static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2901
set_rel_consider_parallel
static void set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:589
set_append_rel_size
static void set_append_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:956
create_partial_bitmap_paths
void create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual)
Definition: allpaths.c:4208
set_plain_rel_size
static void set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:572
add_paths_to_append_rel
void add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel, List *live_childrels)
Definition: allpaths.c:1321
set_rel_size
static void set_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:360
generate_orderedappend_paths
static void generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel, List *live_childrels, List *all_child_pathkeys)
Definition: allpaths.c:1747
UNSAFE_NOTIN_PARTITIONBY_CLAUSE
#define UNSAFE_NOTIN_PARTITIONBY_CLAUSE
Definition: allpaths.c:56
recurse_pushdown_safe
static bool recurse_pushdown_safe(Node *setOp, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3678
pushdown_safe_type
pushdown_safe_type
Definition: allpaths.c:71
PUSHDOWN_WINDOWCLAUSE_RUNCOND
@ PUSHDOWN_WINDOWCLAUSE_RUNCOND
Definition: allpaths.c:74
PUSHDOWN_UNSAFE
@ PUSHDOWN_UNSAFE
Definition: allpaths.c:72
PUSHDOWN_SAFE
@ PUSHDOWN_SAFE
Definition: allpaths.c:73
accumulate_append_subpath
static void accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths)
Definition: allpaths.c:2130
min_parallel_index_scan_size
int min_parallel_index_scan_size
Definition: allpaths.c:82
min_parallel_table_scan_size
int min_parallel_table_scan_size
Definition: allpaths.c:81
adjust_appendrel_attrs
Node * adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos, AppendRelInfo **appinfos)
Definition: appendinfo.c:200
AttrNumber
int16 AttrNumber
Definition: attnum.h:21
InvalidAttrNumber
#define InvalidAttrNumber
Definition: attnum.h:23
pprint
void pprint(const void *obj)
Definition: print.c:54
bms_equal
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:142
bms_is_subset
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:412
bms_is_member
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
bms_add_member
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
bms_membership
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
bms_overlap
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:582
bms_get_singleton_member
bool bms_get_singleton_member(const Bitmapset *a, int *member)
Definition: bitmapset.c:715
bms_is_empty
#define bms_is_empty(a)
Definition: bitmapset.h:118
BMS_SINGLETON
@ BMS_SINGLETON
Definition: bitmapset.h:72
BMS_MULTIPLE
@ BMS_MULTIPLE
Definition: bitmapset.h:73
BlockNumber
uint32 BlockNumber
Definition: block.h:31
Min
#define Min(x, y)
Definition: c.h:975
Max
#define Max(x, y)
Definition: c.h:969
int32
int32_t int32
Definition: c.h:498
Index
unsigned int Index
Definition: c.h:585
OidIsValid
#define OidIsValid(objectId)
Definition: c.h:746
is_pseudo_constant_clause
bool is_pseudo_constant_clause(Node *clause)
Definition: clauses.c:2090
contain_leaked_vars
bool contain_leaked_vars(Node *clause)
Definition: clauses.c:1264
is_parallel_safe
bool is_parallel_safe(PlannerInfo *root, Node *node)
Definition: clauses.c:754
contain_subplans
bool contain_subplans(Node *clause)
Definition: clauses.c:331
contain_volatile_functions
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:539
CompareType
CompareType
Definition: cmptype.h:32
COMPARE_LE
@ COMPARE_LE
Definition: cmptype.h:35
COMPARE_GT
@ COMPARE_GT
Definition: cmptype.h:38
COMPARE_EQ
@ COMPARE_EQ
Definition: cmptype.h:36
COMPARE_GE
@ COMPARE_GE
Definition: cmptype.h:37
COMPARE_LT
@ COMPARE_LT
Definition: cmptype.h:34
set_namedtuplestore_size_estimates
void set_namedtuplestore_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6099
max_parallel_workers_per_gather
int max_parallel_workers_per_gather
Definition: costsize.c:143
set_baserel_size_estimates
void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5335
set_function_size_estimates
void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5969
set_cte_size_estimates
void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel, double cte_rows)
Definition: costsize.c:6061
compute_gather_rows
double compute_gather_rows(Path *path)
Definition: costsize.c:6611
set_result_size_estimates
void set_result_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6132
enable_partitionwise_join
bool enable_partitionwise_join
Definition: costsize.c:159
compute_bitmap_pages
double compute_bitmap_pages(PlannerInfo *root, RelOptInfo *baserel, Path *bitmapqual, double loop_count, Cost *cost_p, double *tuples_p)
Definition: costsize.c:6500
set_subquery_size_estimates
void set_subquery_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5889
enable_parallel_append
bool enable_parallel_append
Definition: costsize.c:161
set_foreign_size_estimates
void set_foreign_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6161
clamp_row_est
double clamp_row_est(double nrows)
Definition: costsize.c:213
set_tablefunc_size_estimates
void set_tablefunc_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6007
set_values_size_estimates
void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:6029
enable_incremental_sort
bool enable_incremental_sort
Definition: costsize.c:151
ERROR
#define ERROR
Definition: elog.h:39
elog
#define elog(elevel,...)
Definition: elog.h:225
add_child_rel_equivalences
void add_child_rel_equivalences(PlannerInfo *root, AppendRelInfo *appinfo, RelOptInfo *parent_rel, RelOptInfo *child_rel)
Definition: equivclass.c:2833
relation_can_be_sorted_early
bool relation_can_be_sorted_early(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, bool require_parallel_safe)
Definition: equivclass.c:1077
OidFunctionCall1
#define OidFunctionCall1(functionId, arg1)
Definition: fmgr.h:720
geqo
RelOptInfo * geqo(PlannerInfo *root, int number_of_rels, List *initial_rels)
Definition: geqo_main.c:72
Assert
Assert(PointerIsAligned(start, uint64))
check_index_predicates
void check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:3966
create_index_paths
void create_index_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:239
i
int i
Definition: isn.c:77
if
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:81
join_search_one_level
void join_search_one_level(PlannerInfo *root, int level)
Definition: joinrels.c:73
mark_dummy_rel
void mark_dummy_rel(RelOptInfo *rel)
Definition: joinrels.c:1385
lappend
List * lappend(List *list, void *datum)
Definition: list.c:339
list_copy_tail
List * list_copy_tail(const List *oldlist, int nskip)
Definition: list.c:1613
list_concat
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
list_free
void list_free(List *list)
Definition: list.c:1546
list_copy_head
List * list_copy_head(const List *oldlist, int len)
Definition: list.c:1593
get_rel_persistence
char get_rel_persistence(Oid relid)
Definition: lsyscache.c:2218
func_parallel
char func_parallel(Oid funcid)
Definition: lsyscache.c:1939
get_opfamily_member_for_cmptype
Oid get_opfamily_member_for_cmptype(Oid opfamily, Oid lefttype, Oid righttype, CompareType cmptype)
Definition: lsyscache.c:196
get_func_support
RegProcedure get_func_support(Oid funcid)
Definition: lsyscache.c:1998
func_strict
bool func_strict(Oid funcid)
Definition: lsyscache.c:1901
get_op_index_interpretation
List * get_op_index_interpretation(Oid opno)
Definition: lsyscache.c:672
get_typavgwidth
int32 get_typavgwidth(Oid typid, int32 typmod)
Definition: lsyscache.c:2718
subpath
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:311
makeNullConst
Const * makeNullConst(Oid consttype, int32 consttypmod, Oid constcollid)
Definition: makefuncs.c:388
make_and_qual
Node * make_and_qual(Node *qual1, Node *qual2)
Definition: makefuncs.c:780
pfree
void pfree(void *pointer)
Definition: mcxt.c:1528
palloc0
void * palloc0(Size size)
Definition: mcxt.c:1351
exprType
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
exprTypmod
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:301
exprCollation
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:821
expression_returns_set
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:763
set_opfuncid
void set_opfuncid(OpExpr *opexpr)
Definition: nodeFuncs.c:1872
IsA
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
copyObject
#define copyObject(obj)
Definition: nodes.h:230
nodeTag
#define nodeTag(nodeptr)
Definition: nodes.h:139
makeNode
#define makeNode(_type_)
Definition: nodes.h:161
castNode
#define castNode(_type_, nodeptr)
Definition: nodes.h:182
JOIN_SEMI
@ JOIN_SEMI
Definition: nodes.h:313
JOIN_ANTI
@ JOIN_ANTI
Definition: nodes.h:314
PVC_INCLUDE_PLACEHOLDERS
#define PVC_INCLUDE_PLACEHOLDERS
Definition: optimizer.h:196
targetIsInSortList
bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList)
Definition: parse_clause.c:3635
parse_clause.h
SETOP_EXCEPT
@ SETOP_EXCEPT
Definition: parsenodes.h:2170
RTE_JOIN
@ RTE_JOIN
Definition: parsenodes.h:1028
RTE_CTE
@ RTE_CTE
Definition: parsenodes.h:1032
RTE_NAMEDTUPLESTORE
@ RTE_NAMEDTUPLESTORE
Definition: parsenodes.h:1033
RTE_VALUES
@ RTE_VALUES
Definition: parsenodes.h:1031
RTE_SUBQUERY
@ RTE_SUBQUERY
Definition: parsenodes.h:1027
RTE_RESULT
@ RTE_RESULT
Definition: parsenodes.h:1034
RTE_FUNCTION
@ RTE_FUNCTION
Definition: parsenodes.h:1029
RTE_TABLEFUNC
@ RTE_TABLEFUNC
Definition: parsenodes.h:1030
RTE_GROUP
@ RTE_GROUP
Definition: parsenodes.h:1037
RTE_RELATION
@ RTE_RELATION
Definition: parsenodes.h:1026
rt_fetch
#define rt_fetch(rangetable_index, rangetable)
Definition: parsetree.h:31
partitions_are_ordered
bool partitions_are_ordered(PartitionBoundInfo boundinfo, Bitmapset *live_parts)
Definition: partbounds.c:2852
get_cheapest_fractional_path_for_pathkeys
Path * get_cheapest_fractional_path_for_pathkeys(List *paths, List *pathkeys, Relids required_outer, double fraction)
Definition: pathkeys.c:666
get_cheapest_path_for_pathkeys
Path * get_cheapest_path_for_pathkeys(List *paths, List *pathkeys, Relids required_outer, CostSelector cost_criterion, bool require_parallel_safe)
Definition: pathkeys.c:620
pathkeys_count_contained_in
bool pathkeys_count_contained_in(List *keys1, List *keys2, int *n_common)
Definition: pathkeys.c:558
has_useful_pathkeys
bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel)
Definition: pathkeys.c:2319
build_expression_pathkey
List * build_expression_pathkey(PlannerInfo *root, Expr *expr, Oid opno, Relids rel, bool create_it)
Definition: pathkeys.c:1000
build_partition_pathkeys
List * build_partition_pathkeys(PlannerInfo *root, RelOptInfo *partrel, ScanDirection scandir, bool *partialkeys)
Definition: pathkeys.c:919
convert_subquery_pathkeys
List * convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel, List *subquery_pathkeys, List *subquery_tlist)
Definition: pathkeys.c:1054
pathkeys_contained_in
bool pathkeys_contained_in(List *keys1, List *keys2)
Definition: pathkeys.c:343
compare_pathkeys
PathKeysComparison compare_pathkeys(List *keys1, List *keys2)
Definition: pathkeys.c:304
get_cheapest_parallel_safe_total_inner
Path * get_cheapest_parallel_safe_total_inner(List *paths)
Definition: pathkeys.c:699
create_functionscan_path
Path * create_functionscan_path(PlannerInfo *root, RelOptInfo *rel, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2118
create_valuesscan_path
Path * create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2170
create_worktablescan_path
Path * create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2274
create_seqscan_path
Path * create_seqscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer, int parallel_workers)
Definition: pathnode.c:983
create_gather_merge_path
GatherMergePath * create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, List *pathkeys, Relids required_outer, double *rows)
Definition: pathnode.c:1962
set_cheapest
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:269
add_partial_path
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:795
create_append_path
AppendPath * create_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *partial_subpaths, List *pathkeys, Relids required_outer, int parallel_workers, bool parallel_aware, double rows)
Definition: pathnode.c:1300
create_namedtuplestorescan_path
Path * create_namedtuplestorescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2222
create_subqueryscan_path
SubqueryScanPath * create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, bool trivial_pathtarget, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2088
create_incremental_sort_path
IncrementalSortPath * create_incremental_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, int presorted_keys, double limit_tuples)
Definition: pathnode.c:3035
create_bitmap_heap_path
BitmapHeapPath * create_bitmap_heap_path(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual, Relids required_outer, double loop_count, int parallel_degree)
Definition: pathnode.c:1098
create_tablefuncscan_path
Path * create_tablefuncscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2144
create_sort_path
SortPath * create_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, double limit_tuples)
Definition: pathnode.c:3085
create_gather_path
GatherPath * create_gather_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, Relids required_outer, double *rows)
Definition: pathnode.c:2044
create_samplescan_path
Path * create_samplescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1008
create_material_path
MaterialPath * create_material_path(RelOptInfo *rel, Path *subpath)
Definition: pathnode.c:1634
add_path
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:461
compare_path_costs
int compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
Definition: pathnode.c:69
create_resultscan_path
Path * create_resultscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2248
create_ctescan_path
Path * create_ctescan_path(PlannerInfo *root, RelOptInfo *rel, List *pathkeys, Relids required_outer)
Definition: pathnode.c:2196
create_merge_append_path
MergeAppendPath * create_merge_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *pathkeys, Relids required_outer)
Definition: pathnode.c:1471
reparameterize_path
Path * reparameterize_path(PlannerInfo *root, Path *path, Relids required_outer, double loop_count)
Definition: pathnode.c:4106
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:863
IS_DUMMY_REL
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:2080
IS_JOIN_REL
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:868
TOTAL_COST
@ TOTAL_COST
Definition: pathnodes.h:38
STARTUP_COST
@ STARTUP_COST
Definition: pathnodes.h:38
IS_PARTITIONED_REL
#define IS_PARTITIONED_REL(rel)
Definition: pathnodes.h:1086
PATH_REQ_OUTER
#define PATH_REQ_OUTER(path)
Definition: pathnodes.h:1803
Relids
Bitmapset * Relids
Definition: pathnodes.h:30
UPPERREL_FINAL
@ UPPERREL_FINAL
Definition: pathnodes.h:79
RELOPT_BASEREL
@ RELOPT_BASEREL
Definition: pathnodes.h:851
RELOPT_OTHER_MEMBER_REL
@ RELOPT_OTHER_MEMBER_REL
Definition: pathnodes.h:853
set_rel_pathlist_hook_type
void(* set_rel_pathlist_hook_type)(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: paths.h:30
join_search_hook_type
RelOptInfo *(* join_search_hook_type)(PlannerInfo *root, int levels_needed, List *initial_rels)
Definition: paths.h:46
PATHKEYS_EQUAL
@ PATHKEYS_EQUAL
Definition: paths.h:213
arg
void * arg
Definition: pg_backup_utils.c:29
pg_bitutils.h
pg_leftmost_one_pos32
static int pg_leftmost_one_pos32(uint32 word)
Definition: pg_bitutils.h:41
pg_class.h
lfirst
#define lfirst(lc)
Definition: pg_list.h:172
list_length
static int list_length(const List *l)
Definition: pg_list.h:152
NIL
#define NIL
Definition: pg_list.h:68
forboth
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:518
foreach_current_index
#define foreach_current_index(var_or_cell)
Definition: pg_list.h:403
list_make1
#define list_make1(x1)
Definition: pg_list.h:212
for_each_from
#define for_each_from(cell, lst, N)
Definition: pg_list.h:414
list_nth
static void * list_nth(const List *list, int n)
Definition: pg_list.h:299
linitial
#define linitial(l)
Definition: pg_list.h:178
lsecond
#define lsecond(l)
Definition: pg_list.h:183
list_head
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
list_nth_node
#define list_nth_node(type, list, n)
Definition: pg_list.h:327
lnext
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
lfirst_oid
#define lfirst_oid(lc)
Definition: pg_list.h:174
list_nth_int
static int list_nth_int(const List *list, int n)
Definition: pg_list.h:310
pg_operator.h
pg_proc.h
relation_excluded_by_constraints
bool relation_excluded_by_constraints(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: plancat.c:1596
get_cheapest_fractional_path
Path * get_cheapest_fractional_path(RelOptInfo *rel, double tuple_fraction)
Definition: planner.c:6529
subquery_planner
PlannerInfo * subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, bool hasRecursion, double tuple_fraction, SetOperationStmt *setops)
Definition: planner.c:650
limit_needed
bool limit_needed(Query *parse)
Definition: planner.c:2709
MONOTONICFUNC_NONE
@ MONOTONICFUNC_NONE
Definition: plannodes.h:1761
MONOTONICFUNC_DECREASING
@ MONOTONICFUNC_DECREASING
Definition: plannodes.h:1763
MONOTONICFUNC_INCREASING
@ MONOTONICFUNC_INCREASING
Definition: plannodes.h:1762
MONOTONICFUNC_BOTH
@ MONOTONICFUNC_BOTH
Definition: plannodes.h:1764
PointerGetDatum
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:327
DatumGetPointer
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:317
InvalidOid
#define InvalidOid
Definition: postgres_ext.h:35
Oid
unsigned int Oid
Definition: postgres_ext.h:30
root
tree ctl root
Definition: radixtree.h:1857
parse
static struct subre * parse(struct vars *v, int stopper, int type, struct state *init, struct state *final)
Definition: regcomp.c:717
find_base_rel
RelOptInfo * find_base_rel(PlannerInfo *root, int relid)
Definition: relnode.c:414
fetch_upper_rel
RelOptInfo * fetch_upper_rel(PlannerInfo *root, UpperRelationKind kind, Relids relids)
Definition: relnode.c:1458
ReplaceVarsFromTargetList
Node * ReplaceVarsFromTargetList(Node *node, int target_varno, int sublevels_up, RangeTblEntry *target_rte, List *targetlist, int result_relation, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno, bool *outer_hasSubLinks)
Definition: rewriteManip.c:1961
REPLACEVARS_REPORT_ERROR
@ REPLACEVARS_REPORT_ERROR
Definition: rewriteManip.h:39
BackwardScanDirection
@ BackwardScanDirection
Definition: sdir.h:26
ForwardScanDirection
@ ForwardScanDirection
Definition: sdir.h:28
check_stack_depth
void check_stack_depth(void)
Definition: stack_depth.c:95
AppendPath::first_partial_path
int first_partial_path
Definition: pathnodes.h:2068
AppendPath::subpaths
List * subpaths
Definition: pathnodes.h:2066
AppendRelInfo::child_relid
Index child_relid
Definition: pathnodes.h:3111
AppendRelInfo::parent_relid
Index parent_relid
Definition: pathnodes.h:3110
FromExpr::quals
Node * quals
Definition: primnodes.h:2338
List
Definition: pg_list.h:54
Node
Definition: nodes.h:135
OpExpr::opno
Oid opno
Definition: primnodes.h:835
OpExpr::args
List * args
Definition: primnodes.h:853
OpIndexInterpretation::cmptype
CompareType cmptype
Definition: lsyscache.h:28
PathTarget::exprs
List * exprs
Definition: pathnodes.h:1666
Path::pathkeys
List * pathkeys
Definition: pathnodes.h:1799
Path::rows
Cardinality rows
Definition: pathnodes.h:1793
Path::parallel_workers
int parallel_workers
Definition: pathnodes.h:1790
Path::total_cost
Cost total_cost
Definition: pathnodes.h:1796
Path::parallel_aware
bool parallel_aware
Definition: pathnodes.h:1786
Plan::plan_rows
Cardinality plan_rows
Definition: plannodes.h:178
Plan::targetlist
List * targetlist
Definition: plannodes.h:202
PlannerInfo::cte_plan_ids
List * cte_plan_ids
Definition: pathnodes.h:326
PlannerInfo::non_recursive_path
struct Path * non_recursive_path
Definition: pathnodes.h:559
PlannerInfo::parse
Query * parse
Definition: pathnodes.h:223
Query::limitCount
Node * limitCount
Definition: parsenodes.h:225
Query::jointree
FromExpr * jointree
Definition: parsenodes.h:177
Query::setOperations
Node * setOperations
Definition: parsenodes.h:230
Query::cteList
List * cteList
Definition: parsenodes.h:168
Query::groupClause
List * groupClause
Definition: parsenodes.h:211
Query::havingQual
Node * havingQual
Definition: parsenodes.h:216
Query::rtable
List * rtable
Definition: parsenodes.h:170
Query::limitOffset
Node * limitOffset
Definition: parsenodes.h:224
Query::windowClause
List * windowClause
Definition: parsenodes.h:218
Query::targetList
List * targetList
Definition: parsenodes.h:193
Query::groupingSets
List * groupingSets
Definition: parsenodes.h:214
Query::distinctClause
List * distinctClause
Definition: parsenodes.h:220
RangeTblEntry::ctename
char * ctename
Definition: parsenodes.h:1210
RangeTblEntry::ctelevelsup
Index ctelevelsup
Definition: parsenodes.h:1212
RangeTblEntry::funcordinality
bool funcordinality
Definition: parsenodes.h:1193
RangeTblEntry::tablesample
struct TableSampleClause * tablesample
Definition: parsenodes.h:1112
RangeTblEntry::subquery
Query * subquery
Definition: parsenodes.h:1118
RangeTblEntry::values_lists
List * values_lists
Definition: parsenodes.h:1204
RangeTblEntry::functions
List * functions
Definition: parsenodes.h:1191
RangeTblEntry::rtekind
RTEKind rtekind
Definition: parsenodes.h:1061
RelOptInfo::baserestrictinfo
List * baserestrictinfo
Definition: pathnodes.h:1009
RelOptInfo::consider_param_startup
bool consider_param_startup
Definition: pathnodes.h:909
RelOptInfo::subplan_params
List * subplan_params
Definition: pathnodes.h:978
RelOptInfo::joininfo
List * joininfo
Definition: pathnodes.h:1015
RelOptInfo::relids
Relids relids
Definition: pathnodes.h:895
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition: pathnodes.h:917
RelOptInfo::relid
Index relid
Definition: pathnodes.h:942
RelOptInfo::tuples
Cardinality tuples
Definition: pathnodes.h:973
RelOptInfo::consider_parallel
bool consider_parallel
Definition: pathnodes.h:911
RelOptInfo::pages
BlockNumber pages
Definition: pathnodes.h:972
RelOptInfo::lateral_relids
Relids lateral_relids
Definition: pathnodes.h:937
RelOptInfo::pathlist
List * pathlist
Definition: pathnodes.h:922
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition: pathnodes.h:889
RelOptInfo::cheapest_startup_path
struct Path * cheapest_startup_path
Definition: pathnodes.h:925
RelOptInfo::cheapest_total_path
struct Path * cheapest_total_path
Definition: pathnodes.h:926
RelOptInfo::has_eclass_joins
bool has_eclass_joins
Definition: pathnodes.h:1017
RelOptInfo::consider_startup
bool consider_startup
Definition: pathnodes.h:907
RelOptInfo::live_parts
Bitmapset * live_parts
Definition: pathnodes.h:1063
RelOptInfo::rel_parallel_workers
int rel_parallel_workers
Definition: pathnodes.h:980
RelOptInfo::consider_partitionwise_join
bool consider_partitionwise_join
Definition: pathnodes.h:1023
RelOptInfo::partial_pathlist
List * partial_pathlist
Definition: pathnodes.h:924
RelOptInfo::subroot
PlannerInfo * subroot
Definition: pathnodes.h:977
RelOptInfo::max_attr
AttrNumber max_attr
Definition: pathnodes.h:950
RelOptInfo::nulling_relids
Relids nulling_relids
Definition: pathnodes.h:962
RelOptInfo::rows
Cardinality rows
Definition: pathnodes.h:901
RelOptInfo::min_attr
AttrNumber min_attr
Definition: pathnodes.h:948
RelOptInfo::rtekind
RTEKind rtekind
Definition: pathnodes.h:946
RestrictInfo::clause
Expr * clause
Definition: pathnodes.h:2705
SetOperationStmt::op
SetOperation op
Definition: parsenodes.h:2247
SpecialJoinInfo::jointype
JoinType jointype
Definition: pathnodes.h:3039
SpecialJoinInfo::syn_righthand
Relids syn_righthand
Definition: pathnodes.h:3038
SupportRequestWFuncMonotonic::window_clause
struct WindowClause * window_clause
Definition: supportnodes.h:296
SupportRequestWFuncMonotonic::monotonic
MonotonicFunction monotonic
Definition: supportnodes.h:299
TargetEntry::expr
Expr * expr
Definition: primnodes.h:2219
TargetEntry::resno
AttrNumber resno
Definition: primnodes.h:2221
TargetEntry::ressortgroupref
Index ressortgroupref
Definition: primnodes.h:2225
TsmRoutine::repeatable_across_scans
bool repeatable_across_scans
Definition: tsmapi.h:65
TsmRoutine::SampleScanGetSampleSize
SampleScanGetSampleSize_function SampleScanGetSampleSize
Definition: tsmapi.h:68
Var
Definition: primnodes.h:262
Var::varattno
AttrNumber varattno
Definition: primnodes.h:274
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Definition: primnodes.h:269
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Definition: primnodes.h:294
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Definition: primnodes.h:584
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Definition: allpaths.c:61
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Definition: allpaths.c:62
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Definition: allpaths.c:65
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Definition: allpaths.c:66
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Definition: regcomp.c:282
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Definition: sysattr.h:27
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Definition: tablesample.c:27
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Definition: tlist.c:624
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Definition: var.c:653
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Definition: var.c:296