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indxpath.c
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1/*-------------------------------------------------------------------------
2 *
3 * indxpath.c
4 * Routines to determine which indexes are usable for scanning a
5 * given relation, and create Paths accordingly.
6 *
7 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
9 *
10 *
11 * IDENTIFICATION
12 * src/backend/optimizer/path/indxpath.c
13 *
14 *-------------------------------------------------------------------------
15 */
16#include "postgres.h"
17
18#include "access/stratnum.h"
19#include "access/sysattr.h"
20#include "access/transam.h"
21#include "catalog/pg_am.h"
22#include "catalog/pg_amop.h"
23#include "catalog/pg_operator.h"
24#include "catalog/pg_opfamily.h"
25#include "catalog/pg_type.h"
26#include "nodes/makefuncs.h"
27#include "nodes/nodeFuncs.h"
28#include "nodes/supportnodes.h"
29#include "optimizer/cost.h"
30#include "optimizer/optimizer.h"
31#include "optimizer/pathnode.h"
32#include "optimizer/paths.h"
33#include "optimizer/prep.h"
34#include "optimizer/restrictinfo.h"
35#include "utils/lsyscache.h"
36#include "utils/selfuncs.h"
37
38
39/* XXX see PartCollMatchesExprColl */
40#define IndexCollMatchesExprColl(idxcollation, exprcollation) \
41 ((idxcollation) == InvalidOid || (idxcollation) == (exprcollation))
42
43/* Whether we are looking for plain indexscan, bitmap scan, or either */
44typedef enum
45{
46 ST_INDEXSCAN, /* must support amgettuple */
47 ST_BITMAPSCAN, /* must support amgetbitmap */
48 ST_ANYSCAN, /* either is okay */
49} ScanTypeControl;
50
51/* Data structure for collecting qual clauses that match an index */
52typedef struct
53{
54 bool nonempty; /* True if lists are not all empty */
55 /* Lists of IndexClause nodes, one list per index column */
56 List *indexclauses[INDEX_MAX_KEYS];
57} IndexClauseSet;
58
59/* Per-path data used within choose_bitmap_and() */
60typedef struct
61{
62 Path *path; /* IndexPath, BitmapAndPath, or BitmapOrPath */
63 List *quals; /* the WHERE clauses it uses */
64 List *preds; /* predicates of its partial index(es) */
65 Bitmapset *clauseids; /* quals+preds represented as a bitmapset */
66 bool unclassifiable; /* has too many quals+preds to process? */
67} PathClauseUsage;
68
69/* Callback argument for ec_member_matches_indexcol */
70typedef struct
71{
72 IndexOptInfo *index; /* index we're considering */
73 int indexcol; /* index column we want to match to */
74} ec_member_matches_arg;
75
76
77static void consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
78 IndexOptInfo *index,
79 IndexClauseSet *rclauseset,
80 IndexClauseSet *jclauseset,
81 IndexClauseSet *eclauseset,
82 List **bitindexpaths);
83static void consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
84 IndexOptInfo *index,
85 IndexClauseSet *rclauseset,
86 IndexClauseSet *jclauseset,
87 IndexClauseSet *eclauseset,
88 List **bitindexpaths,
89 List *indexjoinclauses,
90 int considered_clauses,
91 List **considered_relids);
92static void get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
93 IndexOptInfo *index,
94 IndexClauseSet *rclauseset,
95 IndexClauseSet *jclauseset,
96 IndexClauseSet *eclauseset,
97 List **bitindexpaths,
98 Relids relids,
99 List **considered_relids);
100static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
101 List *indexjoinclauses);
102static void get_index_paths(PlannerInfo *root, RelOptInfo *rel,
103 IndexOptInfo *index, IndexClauseSet *clauses,
104 List **bitindexpaths);
105static List *build_index_paths(PlannerInfo *root, RelOptInfo *rel,
106 IndexOptInfo *index, IndexClauseSet *clauses,
107 bool useful_predicate,
108 ScanTypeControl scantype,
109 bool *skip_nonnative_saop);
110static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
111 List *clauses, List *other_clauses);
112static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
113 List *clauses, List *other_clauses);
114static Path *choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel,
115 List *paths);
116static int path_usage_comparator(const void *a, const void *b);
117static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel,
118 Path *ipath);
119static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel,
120 List *paths);
121static PathClauseUsage *classify_index_clause_usage(Path *path,
122 List **clauselist);
123static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds);
124static int find_list_position(Node *node, List **nodelist);
125static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index);
126static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids);
127static double adjust_rowcount_for_semijoins(PlannerInfo *root,
128 Index cur_relid,
129 Index outer_relid,
130 double rowcount);
131static double approximate_joinrel_size(PlannerInfo *root, Relids relids);
132static void match_restriction_clauses_to_index(PlannerInfo *root,
133 IndexOptInfo *index,
134 IndexClauseSet *clauseset);
135static void match_join_clauses_to_index(PlannerInfo *root,
136 RelOptInfo *rel, IndexOptInfo *index,
137 IndexClauseSet *clauseset,
138 List **joinorclauses);
139static void match_eclass_clauses_to_index(PlannerInfo *root,
140 IndexOptInfo *index,
141 IndexClauseSet *clauseset);
142static void match_clauses_to_index(PlannerInfo *root,
143 List *clauses,
144 IndexOptInfo *index,
145 IndexClauseSet *clauseset);
146static void match_clause_to_index(PlannerInfo *root,
147 RestrictInfo *rinfo,
148 IndexOptInfo *index,
149 IndexClauseSet *clauseset);
150static IndexClause *match_clause_to_indexcol(PlannerInfo *root,
151 RestrictInfo *rinfo,
152 int indexcol,
153 IndexOptInfo *index);
154static bool IsBooleanOpfamily(Oid opfamily);
155static IndexClause *match_boolean_index_clause(PlannerInfo *root,
156 RestrictInfo *rinfo,
157 int indexcol, IndexOptInfo *index);
158static IndexClause *match_opclause_to_indexcol(PlannerInfo *root,
159 RestrictInfo *rinfo,
160 int indexcol,
161 IndexOptInfo *index);
162static IndexClause *match_funcclause_to_indexcol(PlannerInfo *root,
163 RestrictInfo *rinfo,
164 int indexcol,
165 IndexOptInfo *index);
166static IndexClause *get_index_clause_from_support(PlannerInfo *root,
167 RestrictInfo *rinfo,
168 Oid funcid,
169 int indexarg,
170 int indexcol,
171 IndexOptInfo *index);
172static IndexClause *match_saopclause_to_indexcol(PlannerInfo *root,
173 RestrictInfo *rinfo,
174 int indexcol,
175 IndexOptInfo *index);
176static IndexClause *match_rowcompare_to_indexcol(PlannerInfo *root,
177 RestrictInfo *rinfo,
178 int indexcol,
179 IndexOptInfo *index);
180static IndexClause *match_orclause_to_indexcol(PlannerInfo *root,
181 RestrictInfo *rinfo,
182 int indexcol,
183 IndexOptInfo *index);
184static IndexClause *expand_indexqual_rowcompare(PlannerInfo *root,
185 RestrictInfo *rinfo,
186 int indexcol,
187 IndexOptInfo *index,
188 Oid expr_op,
189 bool var_on_left);
190static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
191 List **orderby_clauses_p,
192 List **clause_columns_p);
193static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
194 int indexcol, Expr *clause, Oid pk_opfamily);
195static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
196 EquivalenceClass *ec, EquivalenceMember *em,
197 void *arg);
198static bool contain_strippable_phv_walker(Node *node, void *context);
199static Node *strip_phvs_in_index_operand_mutator(Node *node, void *context);
200
201
202/*
203 * create_index_paths()
204 * Generate all interesting index paths for the given relation.
205 * Candidate paths are added to the rel's pathlist (using add_path).
206 *
207 * To be considered for an index scan, an index must match one or more
208 * restriction clauses or join clauses from the query's qual condition,
209 * or match the query's ORDER BY condition, or have a predicate that
210 * matches the query's qual condition.
211 *
212 * There are two basic kinds of index scans. A "plain" index scan uses
213 * only restriction clauses (possibly none at all) in its indexqual,
214 * so it can be applied in any context. A "parameterized" index scan uses
215 * join clauses (plus restriction clauses, if available) in its indexqual.
216 * When joining such a scan to one of the relations supplying the other
217 * variables used in its indexqual, the parameterized scan must appear as
218 * the inner relation of a nestloop join; it can't be used on the outer side,
219 * nor in a merge or hash join. In that context, values for the other rels'
220 * attributes are available and fixed during any one scan of the indexpath.
221 *
222 * An IndexPath is generated and submitted to add_path() for each plain or
223 * parameterized index scan this routine deems potentially interesting for
224 * the current query.
225 *
226 * 'rel' is the relation for which we want to generate index paths
227 *
228 * Note: check_index_predicates() must have been run previously for this rel.
229 *
230 * Note: in cases involving LATERAL references in the relation's tlist, it's
231 * possible that rel->lateral_relids is nonempty. Currently, we include
232 * lateral_relids into the parameterization reported for each path, but don't
233 * take it into account otherwise. The fact that any such rels *must* be
234 * available as parameter sources perhaps should influence our choices of
235 * index quals ... but for now, it doesn't seem worth troubling over.
236 * In particular, comments below about "unparameterized" paths should be read
237 * as meaning "unparameterized so far as the indexquals are concerned".
238 */
239void
240create_index_paths(PlannerInfo *root, RelOptInfo *rel)
241{
242 List *indexpaths;
243 List *bitindexpaths;
244 List *bitjoinpaths;
245 List *joinorclauses;
246 IndexClauseSet rclauseset;
247 IndexClauseSet jclauseset;
248 IndexClauseSet eclauseset;
249 ListCell *lc;
250
251 /* Skip the whole mess if no indexes */
252 if (rel->indexlist == NIL)
253 return;
254
255 /* Bitmap paths are collected and then dealt with at the end */
256 bitindexpaths = bitjoinpaths = joinorclauses = NIL;
257
258 /* Examine each index in turn */
259 foreach(lc, rel->indexlist)
260 {
261 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
262
263 /* Protect limited-size array in IndexClauseSets */
264 Assert(index->nkeycolumns <= INDEX_MAX_KEYS);
265
266 /*
267 * Ignore partial indexes that do not match the query.
268 * (generate_bitmap_or_paths() might be able to do something with
269 * them, but that's of no concern here.)
270 */
271 if (index->indpred != NIL && !index->predOK)
272 continue;
273
274 /*
275 * Identify the restriction clauses that can match the index.
276 */
277 MemSet(&rclauseset, 0, sizeof(rclauseset));
278 match_restriction_clauses_to_index(root, index, &rclauseset);
279
280 /*
281 * Build index paths from the restriction clauses. These will be
282 * non-parameterized paths. Plain paths go directly to add_path(),
283 * bitmap paths are added to bitindexpaths to be handled below.
284 */
285 get_index_paths(root, rel, index, &rclauseset,
286 &bitindexpaths);
287
288 /*
289 * Identify the join clauses that can match the index. For the moment
290 * we keep them separate from the restriction clauses. Note that this
291 * step finds only "loose" join clauses that have not been merged into
292 * EquivalenceClasses. Also, collect join OR clauses for later.
293 */
294 MemSet(&jclauseset, 0, sizeof(jclauseset));
295 match_join_clauses_to_index(root, rel, index,
296 &jclauseset, &joinorclauses);
297
298 /*
299 * Look for EquivalenceClasses that can generate joinclauses matching
300 * the index.
301 */
302 MemSet(&eclauseset, 0, sizeof(eclauseset));
303 match_eclass_clauses_to_index(root, index,
304 &eclauseset);
305
306 /*
307 * If we found any plain or eclass join clauses, build parameterized
308 * index paths using them.
309 */
310 if (jclauseset.nonempty || eclauseset.nonempty)
311 consider_index_join_clauses(root, rel, index,
312 &rclauseset,
313 &jclauseset,
314 &eclauseset,
315 &bitjoinpaths);
316 }
317
318 /*
319 * Generate BitmapOrPaths for any suitable OR-clauses present in the
320 * restriction list. Add these to bitindexpaths.
321 */
322 indexpaths = generate_bitmap_or_paths(root, rel,
323 rel->baserestrictinfo, NIL);
324 bitindexpaths = list_concat(bitindexpaths, indexpaths);
325
326 /*
327 * Likewise, generate BitmapOrPaths for any suitable OR-clauses present in
328 * the joinclause list. Add these to bitjoinpaths.
329 */
330 indexpaths = generate_bitmap_or_paths(root, rel,
331 joinorclauses, rel->baserestrictinfo);
332 bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
333
334 /*
335 * If we found anything usable, generate a BitmapHeapPath for the most
336 * promising combination of restriction bitmap index paths. Note there
337 * will be only one such path no matter how many indexes exist. This
338 * should be sufficient since there's basically only one figure of merit
339 * (total cost) for such a path.
340 */
341 if (bitindexpaths != NIL)
342 {
343 Path *bitmapqual;
344 BitmapHeapPath *bpath;
345
346 bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
347 bpath = create_bitmap_heap_path(root, rel, bitmapqual,
348 rel->lateral_relids, 1.0, 0);
349 add_path(rel, (Path *) bpath);
350
351 /* create a partial bitmap heap path */
352 if (rel->consider_parallel && rel->lateral_relids == NULL)
353 create_partial_bitmap_paths(root, rel, bitmapqual);
354 }
355
356 /*
357 * Likewise, if we found anything usable, generate BitmapHeapPaths for the
358 * most promising combinations of join bitmap index paths. Our strategy
359 * is to generate one such path for each distinct parameterization seen
360 * among the available bitmap index paths. This may look pretty
361 * expensive, but usually there won't be very many distinct
362 * parameterizations. (This logic is quite similar to that in
363 * consider_index_join_clauses, but we're working with whole paths not
364 * individual clauses.)
365 */
366 if (bitjoinpaths != NIL)
367 {
368 List *all_path_outers;
369
370 /* Identify each distinct parameterization seen in bitjoinpaths */
371 all_path_outers = NIL;
372 foreach(lc, bitjoinpaths)
373 {
374 Path *path = (Path *) lfirst(lc);
375 Relids required_outer = PATH_REQ_OUTER(path);
376
377 all_path_outers = list_append_unique(all_path_outers,
378 required_outer);
379 }
380
381 /* Now, for each distinct parameterization set ... */
382 foreach(lc, all_path_outers)
383 {
384 Relids max_outers = (Relids) lfirst(lc);
385 List *this_path_set;
386 Path *bitmapqual;
387 Relids required_outer;
388 double loop_count;
389 BitmapHeapPath *bpath;
390 ListCell *lcp;
391
392 /* Identify all the bitmap join paths needing no more than that */
393 this_path_set = NIL;
394 foreach(lcp, bitjoinpaths)
395 {
396 Path *path = (Path *) lfirst(lcp);
397
398 if (bms_is_subset(PATH_REQ_OUTER(path), max_outers))
399 this_path_set = lappend(this_path_set, path);
400 }
401
402 /*
403 * Add in restriction bitmap paths, since they can be used
404 * together with any join paths.
405 */
406 this_path_set = list_concat(this_path_set, bitindexpaths);
407
408 /* Select best AND combination for this parameterization */
409 bitmapqual = choose_bitmap_and(root, rel, this_path_set);
410
411 /* And push that path into the mix */
412 required_outer = PATH_REQ_OUTER(bitmapqual);
413 loop_count = get_loop_count(root, rel->relid, required_outer);
414 bpath = create_bitmap_heap_path(root, rel, bitmapqual,
415 required_outer, loop_count, 0);
416 add_path(rel, (Path *) bpath);
417 }
418 }
419}
420
421/*
422 * consider_index_join_clauses
423 * Given sets of join clauses for an index, decide which parameterized
424 * index paths to build.
425 *
426 * Plain indexpaths are sent directly to add_path, while potential
427 * bitmap indexpaths are added to *bitindexpaths for later processing.
428 *
429 * 'rel' is the index's heap relation
430 * 'index' is the index for which we want to generate paths
431 * 'rclauseset' is the collection of indexable restriction clauses
432 * 'jclauseset' is the collection of indexable simple join clauses
433 * 'eclauseset' is the collection of indexable clauses from EquivalenceClasses
434 * '*bitindexpaths' is the list to add bitmap paths to
435 */
436static void
437consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
438 IndexOptInfo *index,
439 IndexClauseSet *rclauseset,
440 IndexClauseSet *jclauseset,
441 IndexClauseSet *eclauseset,
442 List **bitindexpaths)
443{
444 int considered_clauses = 0;
445 List *considered_relids = NIL;
446 int indexcol;
447
448 /*
449 * The strategy here is to identify every potentially useful set of outer
450 * rels that can provide indexable join clauses. For each such set,
451 * select all the join clauses available from those outer rels, add on all
452 * the indexable restriction clauses, and generate plain and/or bitmap
453 * index paths for that set of clauses. This is based on the assumption
454 * that it's always better to apply a clause as an indexqual than as a
455 * filter (qpqual); which is where an available clause would end up being
456 * applied if we omit it from the indexquals.
457 *
458 * This looks expensive, but in most practical cases there won't be very
459 * many distinct sets of outer rels to consider. As a safety valve when
460 * that's not true, we use a heuristic: limit the number of outer rel sets
461 * considered to a multiple of the number of clauses considered. (We'll
462 * always consider using each individual join clause, though.)
463 *
464 * For simplicity in selecting relevant clauses, we represent each set of
465 * outer rels as a maximum set of clause_relids --- that is, the indexed
466 * relation itself is also included in the relids set. considered_relids
467 * lists all relids sets we've already tried.
468 */
469 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
470 {
471 /* Consider each applicable simple join clause */
472 considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
473 consider_index_join_outer_rels(root, rel, index,
474 rclauseset, jclauseset, eclauseset,
475 bitindexpaths,
476 jclauseset->indexclauses[indexcol],
477 considered_clauses,
478 &considered_relids);
479 /* Consider each applicable eclass join clause */
480 considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
481 consider_index_join_outer_rels(root, rel, index,
482 rclauseset, jclauseset, eclauseset,
483 bitindexpaths,
484 eclauseset->indexclauses[indexcol],
485 considered_clauses,
486 &considered_relids);
487 }
488}
489
490/*
491 * consider_index_join_outer_rels
492 * Generate parameterized paths based on clause relids in the clause list.
493 *
494 * Workhorse for consider_index_join_clauses; see notes therein for rationale.
495 *
496 * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset', and
497 * 'bitindexpaths' as above
498 * 'indexjoinclauses' is a list of IndexClauses for join clauses
499 * 'considered_clauses' is the total number of clauses considered (so far)
500 * '*considered_relids' is a list of all relids sets already considered
501 */
502static void
503consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
504 IndexOptInfo *index,
505 IndexClauseSet *rclauseset,
506 IndexClauseSet *jclauseset,
507 IndexClauseSet *eclauseset,
508 List **bitindexpaths,
509 List *indexjoinclauses,
510 int considered_clauses,
511 List **considered_relids)
512{
513 ListCell *lc;
514
515 /* Examine relids of each joinclause in the given list */
516 foreach(lc, indexjoinclauses)
517 {
518 IndexClause *iclause = (IndexClause *) lfirst(lc);
519 Relids clause_relids = iclause->rinfo->clause_relids;
520 EquivalenceClass *parent_ec = iclause->rinfo->parent_ec;
521 int num_considered_relids;
522
523 /* If we already tried its relids set, no need to do so again */
524 if (list_member(*considered_relids, clause_relids))
525 continue;
526
527 /*
528 * Generate the union of this clause's relids set with each
529 * previously-tried set. This ensures we try this clause along with
530 * every interesting subset of previous clauses. However, to avoid
531 * exponential growth of planning time when there are many clauses,
532 * limit the number of relid sets accepted to 10 * considered_clauses.
533 *
534 * Note: get_join_index_paths appends entries to *considered_relids,
535 * but we do not need to visit such newly-added entries within this
536 * loop, so we don't use foreach() here. No real harm would be done
537 * if we did visit them, since the subset check would reject them; but
538 * it would waste some cycles.
539 */
540 num_considered_relids = list_length(*considered_relids);
541 for (int pos = 0; pos < num_considered_relids; pos++)
542 {
543 Relids oldrelids = (Relids) list_nth(*considered_relids, pos);
544
545 /*
546 * If either is a subset of the other, no new set is possible.
547 * This isn't a complete test for redundancy, but it's easy and
548 * cheap. get_join_index_paths will check more carefully if we
549 * already generated the same relids set.
550 */
551 if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
552 continue;
553
554 /*
555 * If this clause was derived from an equivalence class, the
556 * clause list may contain other clauses derived from the same
557 * eclass. We should not consider that combining this clause with
558 * one of those clauses generates a usefully different
559 * parameterization; so skip if any clause derived from the same
560 * eclass would already have been included when using oldrelids.
561 */
562 if (parent_ec &&
563 eclass_already_used(parent_ec, oldrelids,
564 indexjoinclauses))
565 continue;
566
567 /*
568 * If the number of relid sets considered exceeds our heuristic
569 * limit, stop considering combinations of clauses. We'll still
570 * consider the current clause alone, though (below this loop).
571 */
572 if (list_length(*considered_relids) >= 10 * considered_clauses)
573 break;
574
575 /* OK, try the union set */
576 get_join_index_paths(root, rel, index,
577 rclauseset, jclauseset, eclauseset,
578 bitindexpaths,
579 bms_union(clause_relids, oldrelids),
580 considered_relids);
581 }
582
583 /* Also try this set of relids by itself */
584 get_join_index_paths(root, rel, index,
585 rclauseset, jclauseset, eclauseset,
586 bitindexpaths,
587 clause_relids,
588 considered_relids);
589 }
590}
591
592/*
593 * get_join_index_paths
594 * Generate index paths using clauses from the specified outer relations.
595 * In addition to generating paths, relids is added to *considered_relids
596 * if not already present.
597 *
598 * Workhorse for consider_index_join_clauses; see notes therein for rationale.
599 *
600 * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset',
601 * 'bitindexpaths', 'considered_relids' as above
602 * 'relids' is the current set of relids to consider (the target rel plus
603 * one or more outer rels)
604 */
605static void
606get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
607 IndexOptInfo *index,
608 IndexClauseSet *rclauseset,
609 IndexClauseSet *jclauseset,
610 IndexClauseSet *eclauseset,
611 List **bitindexpaths,
612 Relids relids,
613 List **considered_relids)
614{
615 IndexClauseSet clauseset;
616 int indexcol;
617
618 /* If we already considered this relids set, don't repeat the work */
619 if (list_member(*considered_relids, relids))
620 return;
621
622 /* Identify indexclauses usable with this relids set */
623 MemSet(&clauseset, 0, sizeof(clauseset));
624
625 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
626 {
627 ListCell *lc;
628
629 /* First find applicable simple join clauses */
630 foreach(lc, jclauseset->indexclauses[indexcol])
631 {
632 IndexClause *iclause = (IndexClause *) lfirst(lc);
633
634 if (bms_is_subset(iclause->rinfo->clause_relids, relids))
635 clauseset.indexclauses[indexcol] =
636 lappend(clauseset.indexclauses[indexcol], iclause);
637 }
638
639 /*
640 * Add applicable eclass join clauses. The clauses generated for each
641 * column are redundant (cf generate_implied_equalities_for_column),
642 * so we need at most one. This is the only exception to the general
643 * rule of using all available index clauses.
644 */
645 foreach(lc, eclauseset->indexclauses[indexcol])
646 {
647 IndexClause *iclause = (IndexClause *) lfirst(lc);
648
649 if (bms_is_subset(iclause->rinfo->clause_relids, relids))
650 {
651 clauseset.indexclauses[indexcol] =
652 lappend(clauseset.indexclauses[indexcol], iclause);
653 break;
654 }
655 }
656
657 /* Add restriction clauses */
658 clauseset.indexclauses[indexcol] =
659 list_concat(clauseset.indexclauses[indexcol],
660 rclauseset->indexclauses[indexcol]);
661
662 if (clauseset.indexclauses[indexcol] != NIL)
663 clauseset.nonempty = true;
664 }
665
666 /* We should have found something, else caller passed silly relids */
667 Assert(clauseset.nonempty);
668
669 /* Build index path(s) using the collected set of clauses */
670 get_index_paths(root, rel, index, &clauseset, bitindexpaths);
671
672 /*
673 * Remember we considered paths for this set of relids.
674 */
675 *considered_relids = lappend(*considered_relids, relids);
676}
677
678/*
679 * eclass_already_used
680 * True if any join clause usable with oldrelids was generated from
681 * the specified equivalence class.
682 */
683static bool
684eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
685 List *indexjoinclauses)
686{
687 ListCell *lc;
688
689 foreach(lc, indexjoinclauses)
690 {
691 IndexClause *iclause = (IndexClause *) lfirst(lc);
692 RestrictInfo *rinfo = iclause->rinfo;
693
694 if (rinfo->parent_ec == parent_ec &&
695 bms_is_subset(rinfo->clause_relids, oldrelids))
696 return true;
697 }
698 return false;
699}
700
701
702/*
703 * get_index_paths
704 * Given an index and a set of index clauses for it, construct IndexPaths.
705 *
706 * Plain indexpaths are sent directly to add_path, while potential
707 * bitmap indexpaths are added to *bitindexpaths for later processing.
708 *
709 * This is a fairly simple frontend to build_index_paths(). Its reason for
710 * existence is mainly to handle ScalarArrayOpExpr quals properly. If the
711 * index AM supports them natively, we should just include them in simple
712 * index paths. If not, we should exclude them while building simple index
713 * paths, and then make a separate attempt to include them in bitmap paths.
714 */
715static void
716get_index_paths(PlannerInfo *root, RelOptInfo *rel,
717 IndexOptInfo *index, IndexClauseSet *clauses,
718 List **bitindexpaths)
719{
720 List *indexpaths;
721 bool skip_nonnative_saop = false;
722 ListCell *lc;
723
724 /*
725 * Build simple index paths using the clauses. Allow ScalarArrayOpExpr
726 * clauses only if the index AM supports them natively.
727 */
728 indexpaths = build_index_paths(root, rel,
729 index, clauses,
730 index->predOK,
731 ST_ANYSCAN,
732 &skip_nonnative_saop);
733
734 /*
735 * Submit all the ones that can form plain IndexScan plans to add_path. (A
736 * plain IndexPath can represent either a plain IndexScan or an
737 * IndexOnlyScan, but for our purposes here that distinction does not
738 * matter. However, some of the indexes might support only bitmap scans,
739 * and those we mustn't submit to add_path here.)
740 *
741 * Also, pick out the ones that are usable as bitmap scans. For that, we
742 * must discard indexes that don't support bitmap scans, and we also are
743 * only interested in paths that have some selectivity; we should discard
744 * anything that was generated solely for ordering purposes.
745 */
746 foreach(lc, indexpaths)
747 {
748 IndexPath *ipath = (IndexPath *) lfirst(lc);
749
750 if (index->amhasgettuple)
751 add_path(rel, (Path *) ipath);
752
753 if (index->amhasgetbitmap &&
754 (ipath->path.pathkeys == NIL ||
755 ipath->indexselectivity < 1.0))
756 *bitindexpaths = lappend(*bitindexpaths, ipath);
757 }
758
759 /*
760 * If there were ScalarArrayOpExpr clauses that the index can't handle
761 * natively, generate bitmap scan paths relying on executor-managed
762 * ScalarArrayOpExpr.
763 */
764 if (skip_nonnative_saop)
765 {
766 indexpaths = build_index_paths(root, rel,
767 index, clauses,
768 false,
769 ST_BITMAPSCAN,
770 NULL);
771 *bitindexpaths = list_concat(*bitindexpaths, indexpaths);
772 }
773}
774
775/*
776 * build_index_paths
777 * Given an index and a set of index clauses for it, construct zero
778 * or more IndexPaths. It also constructs zero or more partial IndexPaths.
779 *
780 * We return a list of paths because (1) this routine checks some cases
781 * that should cause us to not generate any IndexPath, and (2) in some
782 * cases we want to consider both a forward and a backward scan, so as
783 * to obtain both sort orders. Note that the paths are just returned
784 * to the caller and not immediately fed to add_path().
785 *
786 * At top level, useful_predicate should be exactly the index's predOK flag
787 * (ie, true if it has a predicate that was proven from the restriction
788 * clauses). When working on an arm of an OR clause, useful_predicate
789 * should be true if the predicate required the current OR list to be proven.
790 * Note that this routine should never be called at all if the index has an
791 * unprovable predicate.
792 *
793 * scantype indicates whether we want to create plain indexscans, bitmap
794 * indexscans, or both. When it's ST_BITMAPSCAN, we will not consider
795 * index ordering while deciding if a Path is worth generating.
796 *
797 * If skip_nonnative_saop is non-NULL, we ignore ScalarArrayOpExpr clauses
798 * unless the index AM supports them directly, and we set *skip_nonnative_saop
799 * to true if we found any such clauses (caller must initialize the variable
800 * to false). If it's NULL, we do not ignore ScalarArrayOpExpr clauses.
801 *
802 * 'rel' is the index's heap relation
803 * 'index' is the index for which we want to generate paths
804 * 'clauses' is the collection of indexable clauses (IndexClause nodes)
805 * 'useful_predicate' indicates whether the index has a useful predicate
806 * 'scantype' indicates whether we need plain or bitmap scan support
807 * 'skip_nonnative_saop' indicates whether to accept SAOP if index AM doesn't
808 */
809static List *
810build_index_paths(PlannerInfo *root, RelOptInfo *rel,
811 IndexOptInfo *index, IndexClauseSet *clauses,
812 bool useful_predicate,
813 ScanTypeControl scantype,
814 bool *skip_nonnative_saop)
815{
816 List *result = NIL;
817 IndexPath *ipath;
818 List *index_clauses;
819 Relids outer_relids;
820 double loop_count;
821 List *orderbyclauses;
822 List *orderbyclausecols;
823 List *index_pathkeys;
824 List *useful_pathkeys;
825 bool pathkeys_possibly_useful;
826 bool index_is_ordered;
827 bool index_only_scan;
828 int indexcol;
829
830 Assert(skip_nonnative_saop != NULL || scantype == ST_BITMAPSCAN);
831
832 /*
833 * Check that index supports the desired scan type(s)
834 */
835 switch (scantype)
836 {
837 case ST_INDEXSCAN:
838 if (!index->amhasgettuple)
839 return NIL;
840 break;
841 case ST_BITMAPSCAN:
842 if (!index->amhasgetbitmap)
843 return NIL;
844 break;
845 case ST_ANYSCAN:
846 /* either or both are OK */
847 break;
848 }
849
850 /*
851 * 1. Combine the per-column IndexClause lists into an overall list.
852 *
853 * In the resulting list, clauses are ordered by index key, so that the
854 * column numbers form a nondecreasing sequence. (This order is depended
855 * on by btree and possibly other places.) The list can be empty, if the
856 * index AM allows that.
857 *
858 * We also build a Relids set showing which outer rels are required by the
859 * selected clauses. Any lateral_relids are included in that, but not
860 * otherwise accounted for.
861 */
862 index_clauses = NIL;
863 outer_relids = bms_copy(rel->lateral_relids);
864 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
865 {
866 ListCell *lc;
867
868 foreach(lc, clauses->indexclauses[indexcol])
869 {
870 IndexClause *iclause = (IndexClause *) lfirst(lc);
871 RestrictInfo *rinfo = iclause->rinfo;
872
873 if (skip_nonnative_saop && !index->amsearcharray &&
874 IsA(rinfo->clause, ScalarArrayOpExpr))
875 {
876 /*
877 * Caller asked us to generate IndexPaths that omit any
878 * ScalarArrayOpExpr clauses when the underlying index AM
879 * lacks native support.
880 *
881 * We must omit this clause (and tell caller about it).
882 */
883 *skip_nonnative_saop = true;
884 continue;
885 }
886
887 /* OK to include this clause */
888 index_clauses = lappend(index_clauses, iclause);
889 outer_relids = bms_add_members(outer_relids,
890 rinfo->clause_relids);
891 }
892
893 /*
894 * If no clauses match the first index column, check for amoptionalkey
895 * restriction. We can't generate a scan over an index with
896 * amoptionalkey = false unless there's at least one index clause.
897 * (When working on columns after the first, this test cannot fail. It
898 * is always okay for columns after the first to not have any
899 * clauses.)
900 */
901 if (index_clauses == NIL && !index->amoptionalkey)
902 return NIL;
903 }
904
905 /* We do not want the index's rel itself listed in outer_relids */
906 outer_relids = bms_del_member(outer_relids, rel->relid);
907
908 /* Compute loop_count for cost estimation purposes */
909 loop_count = get_loop_count(root, rel->relid, outer_relids);
910
911 /*
912 * 2. Compute pathkeys describing index's ordering, if any, then see how
913 * many of them are actually useful for this query. This is not relevant
914 * if we are only trying to build bitmap indexscans.
915 */
916 pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN &&
917 has_useful_pathkeys(root, rel));
918 index_is_ordered = (index->sortopfamily != NULL);
919 if (index_is_ordered && pathkeys_possibly_useful)
920 {
921 index_pathkeys = build_index_pathkeys(root, index,
922 ForwardScanDirection);
923 useful_pathkeys = truncate_useless_pathkeys(root, rel,
924 index_pathkeys);
925 orderbyclauses = NIL;
926 orderbyclausecols = NIL;
927 }
928 else if (index->amcanorderbyop && pathkeys_possibly_useful)
929 {
930 /*
931 * See if we can generate ordering operators for query_pathkeys or at
932 * least some prefix thereof. Matching to just a prefix of the
933 * query_pathkeys will allow an incremental sort to be considered on
934 * the index's partially sorted results.
935 */
936 match_pathkeys_to_index(index, root->query_pathkeys,
937 &orderbyclauses,
938 &orderbyclausecols);
939 if (list_length(root->query_pathkeys) == list_length(orderbyclauses))
940 useful_pathkeys = root->query_pathkeys;
941 else
942 useful_pathkeys = list_copy_head(root->query_pathkeys,
943 list_length(orderbyclauses));
944 }
945 else
946 {
947 useful_pathkeys = NIL;
948 orderbyclauses = NIL;
949 orderbyclausecols = NIL;
950 }
951
952 /*
953 * 3. Check if an index-only scan is possible. If we're not building
954 * plain indexscans, this isn't relevant since bitmap scans don't support
955 * index data retrieval anyway.
956 */
957 index_only_scan = (scantype != ST_BITMAPSCAN &&
958 check_index_only(rel, index));
959
960 /*
961 * 4. Generate an indexscan path if there are relevant restriction clauses
962 * in the current clauses, OR the index ordering is potentially useful for
963 * later merging or final output ordering, OR the index has a useful
964 * predicate, OR an index-only scan is possible.
965 */
966 if (index_clauses != NIL || useful_pathkeys != NIL || useful_predicate ||
967 index_only_scan)
968 {
969 ipath = create_index_path(root, index,
970 index_clauses,
971 orderbyclauses,
972 orderbyclausecols,
973 useful_pathkeys,
974 ForwardScanDirection,
975 index_only_scan,
976 outer_relids,
977 loop_count,
978 false);
979 result = lappend(result, ipath);
980
981 /*
982 * If appropriate, consider parallel index scan. We don't allow
983 * parallel index scan for bitmap index scans.
984 */
985 if (index->amcanparallel &&
986 rel->consider_parallel && outer_relids == NULL &&
987 scantype != ST_BITMAPSCAN)
988 {
989 ipath = create_index_path(root, index,
990 index_clauses,
991 orderbyclauses,
992 orderbyclausecols,
993 useful_pathkeys,
994 ForwardScanDirection,
995 index_only_scan,
996 outer_relids,
997 loop_count,
998 true);
999
1000 /*
1001 * if, after costing the path, we find that it's not worth using
1002 * parallel workers, just free it.
1003 */
1004 if (ipath->path.parallel_workers > 0)
1005 add_partial_path(rel, (Path *) ipath);
1006 else
1007 pfree(ipath);
1008 }
1009 }
1010
1011 /*
1012 * 5. If the index is ordered, a backwards scan might be interesting.
1013 */
1014 if (index_is_ordered && pathkeys_possibly_useful)
1015 {
1016 index_pathkeys = build_index_pathkeys(root, index,
1017 BackwardScanDirection);
1018 useful_pathkeys = truncate_useless_pathkeys(root, rel,
1019 index_pathkeys);
1020 if (useful_pathkeys != NIL)
1021 {
1022 ipath = create_index_path(root, index,
1023 index_clauses,
1024 NIL,
1025 NIL,
1026 useful_pathkeys,
1027 BackwardScanDirection,
1028 index_only_scan,
1029 outer_relids,
1030 loop_count,
1031 false);
1032 result = lappend(result, ipath);
1033
1034 /* If appropriate, consider parallel index scan */
1035 if (index->amcanparallel &&
1036 rel->consider_parallel && outer_relids == NULL &&
1037 scantype != ST_BITMAPSCAN)
1038 {
1039 ipath = create_index_path(root, index,
1040 index_clauses,
1041 NIL,
1042 NIL,
1043 useful_pathkeys,
1044 BackwardScanDirection,
1045 index_only_scan,
1046 outer_relids,
1047 loop_count,
1048 true);
1049
1050 /*
1051 * if, after costing the path, we find that it's not worth
1052 * using parallel workers, just free it.
1053 */
1054 if (ipath->path.parallel_workers > 0)
1055 add_partial_path(rel, (Path *) ipath);
1056 else
1057 pfree(ipath);
1058 }
1059 }
1060 }
1061
1062 return result;
1063}
1064
1065/*
1066 * build_paths_for_OR
1067 * Given a list of restriction clauses from one arm of an OR clause,
1068 * construct all matching IndexPaths for the relation.
1069 *
1070 * Here we must scan all indexes of the relation, since a bitmap OR tree
1071 * can use multiple indexes.
1072 *
1073 * The caller actually supplies two lists of restriction clauses: some
1074 * "current" ones and some "other" ones. Both lists can be used freely
1075 * to match keys of the index, but an index must use at least one of the
1076 * "current" clauses to be considered usable. The motivation for this is
1077 * examples like
1078 * WHERE (x = 42) AND (... OR (y = 52 AND z = 77) OR ....)
1079 * While we are considering the y/z subclause of the OR, we can use "x = 42"
1080 * as one of the available index conditions; but we shouldn't match the
1081 * subclause to any index on x alone, because such a Path would already have
1082 * been generated at the upper level. So we could use an index on x,y,z
1083 * or an index on x,y for the OR subclause, but not an index on just x.
1084 * When dealing with a partial index, a match of the index predicate to
1085 * one of the "current" clauses also makes the index usable.
1086 *
1087 * 'rel' is the relation for which we want to generate index paths
1088 * 'clauses' is the current list of clauses (RestrictInfo nodes)
1089 * 'other_clauses' is the list of additional upper-level clauses
1090 */
1091static List *
1092build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
1093 List *clauses, List *other_clauses)
1094{
1095 List *result = NIL;
1096 List *all_clauses = NIL; /* not computed till needed */
1097 ListCell *lc;
1098
1099 foreach(lc, rel->indexlist)
1100 {
1101 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
1102 IndexClauseSet clauseset;
1103 List *indexpaths;
1104 bool useful_predicate;
1105
1106 /* Ignore index if it doesn't support bitmap scans */
1107 if (!index->amhasgetbitmap)
1108 continue;
1109
1110 /*
1111 * Ignore partial indexes that do not match the query. If a partial
1112 * index is marked predOK then we know it's OK. Otherwise, we have to
1113 * test whether the added clauses are sufficient to imply the
1114 * predicate. If so, we can use the index in the current context.
1115 *
1116 * We set useful_predicate to true iff the predicate was proven using
1117 * the current set of clauses. This is needed to prevent matching a
1118 * predOK index to an arm of an OR, which would be a legal but
1119 * pointlessly inefficient plan. (A better plan will be generated by
1120 * just scanning the predOK index alone, no OR.)
1121 */
1122 useful_predicate = false;
1123 if (index->indpred != NIL)
1124 {
1125 if (index->predOK)
1126 {
1127 /* Usable, but don't set useful_predicate */
1128 }
1129 else
1130 {
1131 /* Form all_clauses if not done already */
1132 if (all_clauses == NIL)
1133 all_clauses = list_concat_copy(clauses, other_clauses);
1134
1135 if (!predicate_implied_by(index->indpred, all_clauses, false))
1136 continue; /* can't use it at all */
1137
1138 if (!predicate_implied_by(index->indpred, other_clauses, false))
1139 useful_predicate = true;
1140 }
1141 }
1142
1143 /*
1144 * Identify the restriction clauses that can match the index.
1145 */
1146 MemSet(&clauseset, 0, sizeof(clauseset));
1147 match_clauses_to_index(root, clauses, index, &clauseset);
1148
1149 /*
1150 * If no matches so far, and the index predicate isn't useful, we
1151 * don't want it.
1152 */
1153 if (!clauseset.nonempty && !useful_predicate)
1154 continue;
1155
1156 /*
1157 * Add "other" restriction clauses to the clauseset.
1158 */
1159 match_clauses_to_index(root, other_clauses, index, &clauseset);
1160
1161 /*
1162 * Construct paths if possible.
1163 */
1164 indexpaths = build_index_paths(root, rel,
1165 index, &clauseset,
1166 useful_predicate,
1167 ST_BITMAPSCAN,
1168 NULL);
1169 result = list_concat(result, indexpaths);
1170 }
1171
1172 return result;
1173}
1174
1175/*
1176 * Utility structure used to group similar OR-clause arguments in
1177 * group_similar_or_args(). It represents information about the OR-clause
1178 * argument and its matching index key.
1179 */
1180typedef struct
1181{
1182 int indexnum; /* index of the matching index, or -1 if no
1183 * matching index */
1184 int colnum; /* index of the matching column, or -1 if no
1185 * matching index */
1186 Oid opno; /* OID of the OpClause operator, or InvalidOid
1187 * if not an OpExpr */
1188 Oid inputcollid; /* OID of the OpClause input collation */
1189 int argindex; /* index of the clause in the list of
1190 * arguments */
1191 int groupindex; /* value of argindex for the fist clause in
1192 * the group of similar clauses */
1193} OrArgIndexMatch;
1194
1195/*
1196 * Comparison function for OrArgIndexMatch which provides sort order placing
1197 * similar OR-clause arguments together.
1198 */
1199static int
1200or_arg_index_match_cmp(const void *a, const void *b)
1201{
1202 const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1203 const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1204
1205 if (match_a->indexnum < match_b->indexnum)
1206 return -1;
1207 else if (match_a->indexnum > match_b->indexnum)
1208 return 1;
1209
1210 if (match_a->colnum < match_b->colnum)
1211 return -1;
1212 else if (match_a->colnum > match_b->colnum)
1213 return 1;
1214
1215 if (match_a->opno < match_b->opno)
1216 return -1;
1217 else if (match_a->opno > match_b->opno)
1218 return 1;
1219
1220 if (match_a->inputcollid < match_b->inputcollid)
1221 return -1;
1222 else if (match_a->inputcollid > match_b->inputcollid)
1223 return 1;
1224
1225 if (match_a->argindex < match_b->argindex)
1226 return -1;
1227 else if (match_a->argindex > match_b->argindex)
1228 return 1;
1229
1230 return 0;
1231}
1232
1233/*
1234 * Another comparison function for OrArgIndexMatch. It sorts groups together
1235 * using groupindex. The group items are then sorted by argindex.
1236 */
1237static int
1238or_arg_index_match_cmp_group(const void *a, const void *b)
1239{
1240 const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1241 const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1242
1243 if (match_a->groupindex < match_b->groupindex)
1244 return -1;
1245 else if (match_a->groupindex > match_b->groupindex)
1246 return 1;
1247
1248 if (match_a->argindex < match_b->argindex)
1249 return -1;
1250 else if (match_a->argindex > match_b->argindex)
1251 return 1;
1252
1253 return 0;
1254}
1255
1256/*
1257 * group_similar_or_args
1258 * Transform incoming OR-restrictinfo into a list of sub-restrictinfos,
1259 * each of them containing a subset of similar OR-clause arguments from
1260 * the source rinfo.
1261 *
1262 * Similar OR-clause arguments are of the form "indexkey op constant" having
1263 * the same indexkey, operator, and collation. Constant may comprise either
1264 * Const or Param. It may be employed later, during the
1265 * match_clause_to_indexcol() to transform the whole OR-sub-rinfo to an SAOP
1266 * clause.
1267 *
1268 * Returns the processed list of OR-clause arguments.
1269 */
1270static List *
1271group_similar_or_args(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *rinfo)
1272{
1273 int n;
1274 int i;
1275 int group_start;
1276 OrArgIndexMatch *matches;
1277 bool matched = false;
1278 ListCell *lc;
1279 ListCell *lc2;
1280 List *orargs;
1281 List *result = NIL;
1282 Index relid = rel->relid;
1283
1284 Assert(IsA(rinfo->orclause, BoolExpr));
1285 orargs = ((BoolExpr *) rinfo->orclause)->args;
1286 n = list_length(orargs);
1287
1288 /*
1289 * To avoid N^2 behavior, take utility pass along the list of OR-clause
1290 * arguments. For each argument, fill the OrArgIndexMatch structure,
1291 * which will be used to sort these arguments at the next step.
1292 */
1293 i = -1;
1294 matches = palloc_array(OrArgIndexMatch, n);
1295 foreach(lc, orargs)
1296 {
1297 Node *arg = lfirst(lc);
1298 RestrictInfo *argrinfo;
1299 OpExpr *clause;
1300 Oid opno;
1301 Node *leftop,
1302 *rightop;
1303 Node *nonConstExpr;
1304 int indexnum;
1305 int colnum;
1306
1307 i++;
1308 matches[i].argindex = i;
1309 matches[i].groupindex = i;
1310 matches[i].indexnum = -1;
1311 matches[i].colnum = -1;
1312 matches[i].opno = InvalidOid;
1313 matches[i].inputcollid = InvalidOid;
1314
1315 if (!IsA(arg, RestrictInfo))
1316 continue;
1317
1318 argrinfo = castNode(RestrictInfo, arg);
1319
1320 /* Only operator clauses can match */
1321 if (!IsA(argrinfo->clause, OpExpr))
1322 continue;
1323
1324 clause = (OpExpr *) argrinfo->clause;
1325 opno = clause->opno;
1326
1327 /* Only binary operators can match */
1328 if (list_length(clause->args) != 2)
1329 continue;
1330
1331 /*
1332 * Ignore any RelabelType node above the operands. This is needed to
1333 * be able to apply indexscanning in binary-compatible-operator cases.
1334 * Note: we can assume there is at most one RelabelType node;
1335 * eval_const_expressions() will have simplified if more than one.
1336 */
1337 leftop = get_leftop(clause);
1338 if (IsA(leftop, RelabelType))
1339 leftop = (Node *) ((RelabelType *) leftop)->arg;
1340
1341 rightop = get_rightop(clause);
1342 if (IsA(rightop, RelabelType))
1343 rightop = (Node *) ((RelabelType *) rightop)->arg;
1344
1345 /*
1346 * Check for clauses of the form: (indexkey operator constant) or
1347 * (constant operator indexkey). But we don't know a particular index
1348 * yet. Therefore, we try to distinguish the potential index key and
1349 * constant first, then search for a matching index key among all
1350 * indexes.
1351 */
1352 if (bms_is_member(relid, argrinfo->right_relids) &&
1353 !bms_is_member(relid, argrinfo->left_relids) &&
1354 !contain_volatile_functions(leftop))
1355 {
1356 opno = get_commutator(opno);
1357
1358 if (!OidIsValid(opno))
1359 {
1360 /* commutator doesn't exist, we can't reverse the order */
1361 continue;
1362 }
1363 nonConstExpr = rightop;
1364 }
1365 else if (bms_is_member(relid, argrinfo->left_relids) &&
1366 !bms_is_member(relid, argrinfo->right_relids) &&
1367 !contain_volatile_functions(rightop))
1368 {
1369 nonConstExpr = leftop;
1370 }
1371 else
1372 {
1373 continue;
1374 }
1375
1376 /*
1377 * Match non-constant part to the index key. It's possible that a
1378 * single non-constant part matches multiple index keys. It's OK, we
1379 * just stop with first matching index key. Given that this choice is
1380 * determined the same for every clause, we will group similar clauses
1381 * together anyway.
1382 */
1383 indexnum = 0;
1384 foreach(lc2, rel->indexlist)
1385 {
1386 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc2);
1387
1388 /*
1389 * Ignore index if it doesn't support bitmap scans or SAOP
1390 * clauses.
1391 */
1392 if (!index->amhasgetbitmap || !index->amsearcharray)
1393 continue;
1394
1395 for (colnum = 0; colnum < index->nkeycolumns; colnum++)
1396 {
1397 if (match_index_to_operand(nonConstExpr, colnum, index))
1398 {
1399 matches[i].indexnum = indexnum;
1400 matches[i].colnum = colnum;
1401 matches[i].opno = opno;
1402 matches[i].inputcollid = clause->inputcollid;
1403 matched = true;
1404 break;
1405 }
1406 }
1407
1408 /*
1409 * Stop looping through the indexes, if we managed to match
1410 * nonConstExpr to any index column.
1411 */
1412 if (matches[i].indexnum >= 0)
1413 break;
1414 indexnum++;
1415 }
1416 }
1417
1418 /*
1419 * Fast-path check: if no clause is matching to the index column, we can
1420 * just give up at this stage and return the clause list as-is.
1421 */
1422 if (!matched)
1423 {
1424 pfree(matches);
1425 return orargs;
1426 }
1427
1428 /*
1429 * Sort clauses to make similar clauses go together. But at the same
1430 * time, we would like to change the order of clauses as little as
1431 * possible. To do so, we reorder each group of similar clauses so that
1432 * the first item of the group stays in place, and all the other items are
1433 * moved after it. So, if there are no similar clauses, the order of
1434 * clauses stays the same. When there are some groups, required
1435 * reordering happens while the rest of the clauses remain in their
1436 * places. That is achieved by assigning a 'groupindex' to each clause:
1437 * the number of the first item in the group in the original clause list.
1438 */
1439 qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp);
1440
1441 /* Assign groupindex to the sorted clauses */
1442 for (i = 1; i < n; i++)
1443 {
1444 /*
1445 * When two clauses are similar and should belong to the same group,
1446 * copy the 'groupindex' from the previous clause. Given we are
1447 * considering clauses in direct order, all the clauses would have a
1448 * 'groupindex' equal to the 'groupindex' of the first clause in the
1449 * group.
1450 */
1451 if (matches[i].indexnum == matches[i - 1].indexnum &&
1452 matches[i].colnum == matches[i - 1].colnum &&
1453 matches[i].opno == matches[i - 1].opno &&
1454 matches[i].inputcollid == matches[i - 1].inputcollid &&
1455 matches[i].indexnum != -1)
1456 matches[i].groupindex = matches[i - 1].groupindex;
1457 }
1458
1459 /* Re-sort clauses first by groupindex then by argindex */
1460 qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp_group);
1461
1462 /*
1463 * Group similar clauses into single sub-restrictinfo. Side effect: the
1464 * resulting list of restrictions will be sorted by indexnum and colnum.
1465 */
1466 group_start = 0;
1467 for (i = 1; i <= n; i++)
1468 {
1469 /* Check if it's a group boundary */
1470 if (group_start >= 0 &&
1471 (i == n ||
1472 matches[i].indexnum != matches[group_start].indexnum ||
1473 matches[i].colnum != matches[group_start].colnum ||
1474 matches[i].opno != matches[group_start].opno ||
1475 matches[i].inputcollid != matches[group_start].inputcollid ||
1476 matches[i].indexnum == -1))
1477 {
1478 /*
1479 * One clause in group: add it "as is" to the upper-level OR.
1480 */
1481 if (i - group_start == 1)
1482 {
1483 result = lappend(result,
1484 list_nth(orargs,
1485 matches[group_start].argindex));
1486 }
1487 else
1488 {
1489 /*
1490 * Two or more clauses in a group: create a nested OR.
1491 */
1492 List *args = NIL;
1493 List *rargs = NIL;
1494 RestrictInfo *subrinfo;
1495 int j;
1496
1497 Assert(i - group_start >= 2);
1498
1499 /* Construct the list of nested OR arguments */
1500 for (j = group_start; j < i; j++)
1501 {
1502 Node *arg = list_nth(orargs, matches[j].argindex);
1503
1504 rargs = lappend(rargs, arg);
1505 if (IsA(arg, RestrictInfo))
1506 args = lappend(args, ((RestrictInfo *) arg)->clause);
1507 else
1508 args = lappend(args, arg);
1509 }
1510
1511 /* Construct the nested OR and wrap it with RestrictInfo */
1512 subrinfo = make_plain_restrictinfo(root,
1513 make_orclause(args),
1514 make_orclause(rargs),
1515 rinfo->is_pushed_down,
1516 rinfo->has_clone,
1517 rinfo->is_clone,
1518 rinfo->pseudoconstant,
1519 rinfo->security_level,
1520 rinfo->required_relids,
1521 rinfo->incompatible_relids,
1522 rinfo->outer_relids);
1523 result = lappend(result, subrinfo);
1524 }
1525
1526 group_start = i;
1527 }
1528 }
1529 pfree(matches);
1530 return result;
1531}
1532
1533/*
1534 * make_bitmap_paths_for_or_group
1535 * Generate bitmap paths for a group of similar OR-clause arguments
1536 * produced by group_similar_or_args().
1537 *
1538 * This function considers two cases: (1) matching a group of clauses to
1539 * the index as a whole, and (2) matching the individual clauses one-by-one.
1540 * (1) typically comprises an optimal solution. If not, (2) typically
1541 * comprises fair alternative.
1542 *
1543 * Ideally, we could consider all arbitrary splits of arguments into
1544 * subgroups, but that could lead to unacceptable computational complexity.
1545 * This is why we only consider two cases of above.
1546 */
1547static List *
1548make_bitmap_paths_for_or_group(PlannerInfo *root, RelOptInfo *rel,
1549 RestrictInfo *ri, List *other_clauses)
1550{
1551 List *jointlist = NIL;
1552 List *splitlist = NIL;
1553 ListCell *lc;
1554 List *orargs;
1555 List *args = ((BoolExpr *) ri->orclause)->args;
1556 Cost jointcost = 0.0,
1557 splitcost = 0.0;
1558 Path *bitmapqual;
1559 List *indlist;
1560
1561 /*
1562 * First, try to match the whole group to the one index.
1563 */
1564 orargs = list_make1(ri);
1565 indlist = build_paths_for_OR(root, rel,
1566 orargs,
1567 other_clauses);
1568 if (indlist != NIL)
1569 {
1570 bitmapqual = choose_bitmap_and(root, rel, indlist);
1571 jointcost = bitmapqual->total_cost;
1572 jointlist = list_make1(bitmapqual);
1573 }
1574
1575 /*
1576 * If we manage to find a bitmap scan, which uses the group of OR-clause
1577 * arguments as a whole, we can skip matching OR-clause arguments
1578 * one-by-one as long as there are no other clauses, which can bring more
1579 * efficiency to one-by-one case.
1580 */
1581 if (jointlist != NIL && other_clauses == NIL)
1582 return jointlist;
1583
1584 /*
1585 * Also try to match all containing clauses one-by-one.
1586 */
1587 foreach(lc, args)
1588 {
1589 orargs = list_make1(lfirst(lc));
1590
1591 indlist = build_paths_for_OR(root, rel,
1592 orargs,
1593 other_clauses);
1594
1595 if (indlist == NIL)
1596 {
1597 splitlist = NIL;
1598 break;
1599 }
1600
1601 bitmapqual = choose_bitmap_and(root, rel, indlist);
1602 splitcost += bitmapqual->total_cost;
1603 splitlist = lappend(splitlist, bitmapqual);
1604 }
1605
1606 /*
1607 * Pick the best option.
1608 */
1609 if (splitlist == NIL)
1610 return jointlist;
1611 else if (jointlist == NIL)
1612 return splitlist;
1613 else
1614 return (jointcost < splitcost) ? jointlist : splitlist;
1615}
1616
1617
1618/*
1619 * generate_bitmap_or_paths
1620 * Look through the list of clauses to find OR clauses, and generate
1621 * a BitmapOrPath for each one we can handle that way. Return a list
1622 * of the generated BitmapOrPaths.
1623 *
1624 * other_clauses is a list of additional clauses that can be assumed true
1625 * for the purpose of generating indexquals, but are not to be searched for
1626 * ORs. (See build_paths_for_OR() for motivation.)
1627 */
1628static List *
1629generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
1630 List *clauses, List *other_clauses)
1631{
1632 List *result = NIL;
1633 List *all_clauses;
1634 ListCell *lc;
1635
1636 /*
1637 * We can use both the current and other clauses as context for
1638 * build_paths_for_OR; no need to remove ORs from the lists.
1639 */
1640 all_clauses = list_concat_copy(clauses, other_clauses);
1641
1642 foreach(lc, clauses)
1643 {
1644 RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1645 List *pathlist;
1646 Path *bitmapqual;
1647 ListCell *j;
1648 List *groupedArgs;
1649 List *inner_other_clauses = NIL;
1650
1651 /* Ignore RestrictInfos that aren't ORs */
1652 if (!restriction_is_or_clause(rinfo))
1653 continue;
1654
1655 /*
1656 * We must be able to match at least one index to each of the arms of
1657 * the OR, else we can't use it.
1658 */
1659 pathlist = NIL;
1660
1661 /*
1662 * Group the similar OR-clause arguments into dedicated RestrictInfos,
1663 * because each of those RestrictInfos has a chance to match the index
1664 * as a whole.
1665 */
1666 groupedArgs = group_similar_or_args(root, rel, rinfo);
1667
1668 if (groupedArgs != ((BoolExpr *) rinfo->orclause)->args)
1669 {
1670 /*
1671 * Some parts of the rinfo were probably grouped. In this case,
1672 * we have a set of sub-rinfos that together are an exact
1673 * duplicate of rinfo. Thus, we need to remove the rinfo from
1674 * other clauses. match_clauses_to_index detects duplicated
1675 * iclauses by comparing pointers to original rinfos that would be
1676 * different. So, we must delete rinfo to avoid de-facto
1677 * duplicated clauses in the index clauses list.
1678 */
1679 inner_other_clauses = list_delete(list_copy(all_clauses), rinfo);
1680 }
1681
1682 foreach(j, groupedArgs)
1683 {
1684 Node *orarg = (Node *) lfirst(j);
1685 List *indlist;
1686
1687 /* OR arguments should be ANDs or sub-RestrictInfos */
1688 if (is_andclause(orarg))
1689 {
1690 List *andargs = ((BoolExpr *) orarg)->args;
1691
1692 indlist = build_paths_for_OR(root, rel,
1693 andargs,
1694 all_clauses);
1695
1696 /* Recurse in case there are sub-ORs */
1697 indlist = list_concat(indlist,
1698 generate_bitmap_or_paths(root, rel,
1699 andargs,
1700 all_clauses));
1701 }
1702 else if (restriction_is_or_clause(castNode(RestrictInfo, orarg)))
1703 {
1704 RestrictInfo *ri = castNode(RestrictInfo, orarg);
1705
1706 /*
1707 * Generate bitmap paths for the group of similar OR-clause
1708 * arguments.
1709 */
1710 indlist = make_bitmap_paths_for_or_group(root,
1711 rel, ri,
1712 inner_other_clauses);
1713
1714 if (indlist == NIL)
1715 {
1716 pathlist = NIL;
1717 break;
1718 }
1719 else
1720 {
1721 pathlist = list_concat(pathlist, indlist);
1722 continue;
1723 }
1724 }
1725 else
1726 {
1727 RestrictInfo *ri = castNode(RestrictInfo, orarg);
1728 List *orargs;
1729
1730 orargs = list_make1(ri);
1731
1732 indlist = build_paths_for_OR(root, rel,
1733 orargs,
1734 all_clauses);
1735 }
1736
1737 /*
1738 * If nothing matched this arm, we can't do anything with this OR
1739 * clause.
1740 */
1741 if (indlist == NIL)
1742 {
1743 pathlist = NIL;
1744 break;
1745 }
1746
1747 /*
1748 * OK, pick the most promising AND combination, and add it to
1749 * pathlist.
1750 */
1751 bitmapqual = choose_bitmap_and(root, rel, indlist);
1752 pathlist = lappend(pathlist, bitmapqual);
1753 }
1754
1755 if (inner_other_clauses != NIL)
1756 list_free(inner_other_clauses);
1757
1758 /*
1759 * If we have a match for every arm, then turn them into a
1760 * BitmapOrPath, and add to result list.
1761 */
1762 if (pathlist != NIL)
1763 {
1764 bitmapqual = (Path *) create_bitmap_or_path(root, rel, pathlist);
1765 result = lappend(result, bitmapqual);
1766 }
1767 }
1768
1769 return result;
1770}
1771
1772
1773/*
1774 * choose_bitmap_and
1775 * Given a nonempty list of bitmap paths, AND them into one path.
1776 *
1777 * This is a nontrivial decision since we can legally use any subset of the
1778 * given path set. We want to choose a good tradeoff between selectivity
1779 * and cost of computing the bitmap.
1780 *
1781 * The result is either a single one of the inputs, or a BitmapAndPath
1782 * combining multiple inputs.
1783 */
1784static Path *
1785choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
1786{
1787 int npaths = list_length(paths);
1788 PathClauseUsage **pathinfoarray;
1789 PathClauseUsage *pathinfo;
1790 List *clauselist;
1791 List *bestpaths = NIL;
1792 Cost bestcost = 0;
1793 int i,
1794 j;
1795 ListCell *l;
1796
1797 Assert(npaths > 0); /* else caller error */
1798 if (npaths == 1)
1799 return (Path *) linitial(paths); /* easy case */
1800
1801 /*
1802 * In theory we should consider every nonempty subset of the given paths.
1803 * In practice that seems like overkill, given the crude nature of the
1804 * estimates, not to mention the possible effects of higher-level AND and
1805 * OR clauses. Moreover, it's completely impractical if there are a large
1806 * number of paths, since the work would grow as O(2^N).
1807 *
1808 * As a heuristic, we first check for paths using exactly the same sets of
1809 * WHERE clauses + index predicate conditions, and reject all but the
1810 * cheapest-to-scan in any such group. This primarily gets rid of indexes
1811 * that include the interesting columns but also irrelevant columns. (In
1812 * situations where the DBA has gone overboard on creating variant
1813 * indexes, this can make for a very large reduction in the number of
1814 * paths considered further.)
1815 *
1816 * We then sort the surviving paths with the cheapest-to-scan first, and
1817 * for each path, consider using that path alone as the basis for a bitmap
1818 * scan. Then we consider bitmap AND scans formed from that path plus
1819 * each subsequent (higher-cost) path, adding on a subsequent path if it
1820 * results in a reduction in the estimated total scan cost. This means we
1821 * consider about O(N^2) rather than O(2^N) path combinations, which is
1822 * quite tolerable, especially given than N is usually reasonably small
1823 * because of the prefiltering step. The cheapest of these is returned.
1824 *
1825 * We will only consider AND combinations in which no two indexes use the
1826 * same WHERE clause. This is a bit of a kluge: it's needed because
1827 * costsize.c and clausesel.c aren't very smart about redundant clauses.
1828 * They will usually double-count the redundant clauses, producing a
1829 * too-small selectivity that makes a redundant AND step look like it
1830 * reduces the total cost. Perhaps someday that code will be smarter and
1831 * we can remove this limitation. (But note that this also defends
1832 * against flat-out duplicate input paths, which can happen because
1833 * match_join_clauses_to_index will find the same OR join clauses that
1834 * extract_restriction_or_clauses has pulled OR restriction clauses out
1835 * of.)
1836 *
1837 * For the same reason, we reject AND combinations in which an index
1838 * predicate clause duplicates another clause. Here we find it necessary
1839 * to be even stricter: we'll reject a partial index if any of its
1840 * predicate clauses are implied by the set of WHERE clauses and predicate
1841 * clauses used so far. This covers cases such as a condition "x = 42"
1842 * used with a plain index, followed by a clauseless scan of a partial
1843 * index "WHERE x >= 40 AND x < 50". The partial index has been accepted
1844 * only because "x = 42" was present, and so allowing it would partially
1845 * double-count selectivity. (We could use predicate_implied_by on
1846 * regular qual clauses too, to have a more intelligent, but much more
1847 * expensive, check for redundancy --- but in most cases simple equality
1848 * seems to suffice.)
1849 */
1850
1851 /*
1852 * Extract clause usage info and detect any paths that use exactly the
1853 * same set of clauses; keep only the cheapest-to-scan of any such groups.
1854 * The surviving paths are put into an array for qsort'ing.
1855 */
1856 pathinfoarray = palloc_array(PathClauseUsage *, npaths);
1857 clauselist = NIL;
1858 npaths = 0;
1859 foreach(l, paths)
1860 {
1861 Path *ipath = (Path *) lfirst(l);
1862
1863 pathinfo = classify_index_clause_usage(ipath, &clauselist);
1864
1865 /* If it's unclassifiable, treat it as distinct from all others */
1866 if (pathinfo->unclassifiable)
1867 {
1868 pathinfoarray[npaths++] = pathinfo;
1869 continue;
1870 }
1871
1872 for (i = 0; i < npaths; i++)
1873 {
1874 if (!pathinfoarray[i]->unclassifiable &&
1875 bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
1876 break;
1877 }
1878 if (i < npaths)
1879 {
1880 /* duplicate clauseids, keep the cheaper one */
1881 Cost ncost;
1882 Cost ocost;
1883 Selectivity nselec;
1884 Selectivity oselec;
1885
1886 cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
1887 cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
1888 if (ncost < ocost)
1889 pathinfoarray[i] = pathinfo;
1890 }
1891 else
1892 {
1893 /* not duplicate clauseids, add to array */
1894 pathinfoarray[npaths++] = pathinfo;
1895 }
1896 }
1897
1898 /* If only one surviving path, we're done */
1899 if (npaths == 1)
1900 return pathinfoarray[0]->path;
1901
1902 /* Sort the surviving paths by index access cost */
1903 qsort(pathinfoarray, npaths, sizeof(PathClauseUsage *),
1904 path_usage_comparator);
1905
1906 /*
1907 * For each surviving index, consider it as an "AND group leader", and see
1908 * whether adding on any of the later indexes results in an AND path with
1909 * cheaper total cost than before. Then take the cheapest AND group.
1910 *
1911 * Note: paths that are either clauseless or unclassifiable will have
1912 * empty clauseids, so that they will not be rejected by the clauseids
1913 * filter here, nor will they cause later paths to be rejected by it.
1914 */
1915 for (i = 0; i < npaths; i++)
1916 {
1917 Cost costsofar;
1918 List *qualsofar;
1919 Bitmapset *clauseidsofar;
1920
1921 pathinfo = pathinfoarray[i];
1922 paths = list_make1(pathinfo->path);
1923 costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
1924 qualsofar = list_concat_copy(pathinfo->quals, pathinfo->preds);
1925 clauseidsofar = bms_copy(pathinfo->clauseids);
1926
1927 for (j = i + 1; j < npaths; j++)
1928 {
1929 Cost newcost;
1930
1931 pathinfo = pathinfoarray[j];
1932 /* Check for redundancy */
1933 if (bms_overlap(pathinfo->clauseids, clauseidsofar))
1934 continue; /* consider it redundant */
1935 if (pathinfo->preds)
1936 {
1937 bool redundant = false;
1938
1939 /* we check each predicate clause separately */
1940 foreach(l, pathinfo->preds)
1941 {
1942 Node *np = (Node *) lfirst(l);
1943
1944 if (predicate_implied_by(list_make1(np), qualsofar, false))
1945 {
1946 redundant = true;
1947 break; /* out of inner foreach loop */
1948 }
1949 }
1950 if (redundant)
1951 continue;
1952 }
1953 /* tentatively add new path to paths, so we can estimate cost */
1954 paths = lappend(paths, pathinfo->path);
1955 newcost = bitmap_and_cost_est(root, rel, paths);
1956 if (newcost < costsofar)
1957 {
1958 /* keep new path in paths, update subsidiary variables */
1959 costsofar = newcost;
1960 qualsofar = list_concat(qualsofar, pathinfo->quals);
1961 qualsofar = list_concat(qualsofar, pathinfo->preds);
1962 clauseidsofar = bms_add_members(clauseidsofar,
1963 pathinfo->clauseids);
1964 }
1965 else
1966 {
1967 /* reject new path, remove it from paths list */
1968 paths = list_truncate(paths, list_length(paths) - 1);
1969 }
1970 }
1971
1972 /* Keep the cheapest AND-group (or singleton) */
1973 if (i == 0 || costsofar < bestcost)
1974 {
1975 bestpaths = paths;
1976 bestcost = costsofar;
1977 }
1978
1979 /* some easy cleanup (we don't try real hard though) */
1980 list_free(qualsofar);
1981 }
1982
1983 if (list_length(bestpaths) == 1)
1984 return (Path *) linitial(bestpaths); /* no need for AND */
1985 return (Path *) create_bitmap_and_path(root, rel, bestpaths);
1986}
1987
1988/* qsort comparator to sort in increasing index access cost order */
1989static int
1990path_usage_comparator(const void *a, const void *b)
1991{
1992 PathClauseUsage *pa = *(PathClauseUsage *const *) a;
1993 PathClauseUsage *pb = *(PathClauseUsage *const *) b;
1994 Cost acost;
1995 Cost bcost;
1996 Selectivity aselec;
1997 Selectivity bselec;
1998
1999 cost_bitmap_tree_node(pa->path, &acost, &aselec);
2000 cost_bitmap_tree_node(pb->path, &bcost, &bselec);
2001
2002 /*
2003 * If costs are the same, sort by selectivity.
2004 */
2005 if (acost < bcost)
2006 return -1;
2007 if (acost > bcost)
2008 return 1;
2009
2010 if (aselec < bselec)
2011 return -1;
2012 if (aselec > bselec)
2013 return 1;
2014
2015 return 0;
2016}
2017
2018/*
2019 * Estimate the cost of actually executing a bitmap scan with a single
2020 * index path (which could be a BitmapAnd or BitmapOr node).
2021 */
2022static Cost
2023bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
2024{
2025 BitmapHeapPath bpath;
2026
2027 /* Set up a dummy BitmapHeapPath */
2028 bpath.path.type = T_BitmapHeapPath;
2029 bpath.path.pathtype = T_BitmapHeapScan;
2030 bpath.path.parent = rel;
2031 bpath.path.pathtarget = rel->reltarget;
2032 bpath.path.param_info = ipath->param_info;
2033 bpath.path.pathkeys = NIL;
2034 bpath.bitmapqual = ipath;
2035
2036 /*
2037 * Check the cost of temporary path without considering parallelism.
2038 * Parallel bitmap heap path will be considered at later stage.
2039 */
2040 bpath.path.parallel_workers = 0;
2041
2042 /* Now we can do cost_bitmap_heap_scan */
2043 cost_bitmap_heap_scan(&bpath.path, root, rel,
2044 bpath.path.param_info,
2045 ipath,
2046 get_loop_count(root, rel->relid,
2047 PATH_REQ_OUTER(ipath)));
2048
2049 return bpath.path.total_cost;
2050}
2051
2052/*
2053 * Estimate the cost of actually executing a BitmapAnd scan with the given
2054 * inputs.
2055 */
2056static Cost
2057bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
2058{
2059 BitmapAndPath *apath;
2060
2061 /*
2062 * Might as well build a real BitmapAndPath here, as the work is slightly
2063 * too complicated to be worth repeating just to save one palloc.
2064 */
2065 apath = create_bitmap_and_path(root, rel, paths);
2066
2067 return bitmap_scan_cost_est(root, rel, (Path *) apath);
2068}
2069
2070
2071/*
2072 * classify_index_clause_usage
2073 * Construct a PathClauseUsage struct describing the WHERE clauses and
2074 * index predicate clauses used by the given indexscan path.
2075 * We consider two clauses the same if they are equal().
2076 *
2077 * At some point we might want to migrate this info into the Path data
2078 * structure proper, but for the moment it's only needed within
2079 * choose_bitmap_and().
2080 *
2081 * *clauselist is used and expanded as needed to identify all the distinct
2082 * clauses seen across successive calls. Caller must initialize it to NIL
2083 * before first call of a set.
2084 */
2085static PathClauseUsage *
2086classify_index_clause_usage(Path *path, List **clauselist)
2087{
2088 PathClauseUsage *result;
2089 Bitmapset *clauseids;
2090 ListCell *lc;
2091
2092 result = palloc_object(PathClauseUsage);
2093 result->path = path;
2094
2095 /* Recursively find the quals and preds used by the path */
2096 result->quals = NIL;
2097 result->preds = NIL;
2098 find_indexpath_quals(path, &result->quals, &result->preds);
2099
2100 /*
2101 * Some machine-generated queries have outlandish numbers of qual clauses.
2102 * To avoid getting into O(N^2) behavior even in this preliminary
2103 * classification step, we want to limit the number of entries we can
2104 * accumulate in *clauselist. Treat any path with more than 100 quals +
2105 * preds as unclassifiable, which will cause calling code to consider it
2106 * distinct from all other paths.
2107 */
2108 if (list_length(result->quals) + list_length(result->preds) > 100)
2109 {
2110 result->clauseids = NULL;
2111 result->unclassifiable = true;
2112 return result;
2113 }
2114
2115 /* Build up a bitmapset representing the quals and preds */
2116 clauseids = NULL;
2117 foreach(lc, result->quals)
2118 {
2119 Node *node = (Node *) lfirst(lc);
2120
2121 clauseids = bms_add_member(clauseids,
2122 find_list_position(node, clauselist));
2123 }
2124 foreach(lc, result->preds)
2125 {
2126 Node *node = (Node *) lfirst(lc);
2127
2128 clauseids = bms_add_member(clauseids,
2129 find_list_position(node, clauselist));
2130 }
2131 result->clauseids = clauseids;
2132 result->unclassifiable = false;
2133
2134 return result;
2135}
2136
2137
2138/*
2139 * find_indexpath_quals
2140 *
2141 * Given the Path structure for a plain or bitmap indexscan, extract lists
2142 * of all the index clauses and index predicate conditions used in the Path.
2143 * These are appended to the initial contents of *quals and *preds (hence
2144 * caller should initialize those to NIL).
2145 *
2146 * Note we are not trying to produce an accurate representation of the AND/OR
2147 * semantics of the Path, but just find out all the base conditions used.
2148 *
2149 * The result lists contain pointers to the expressions used in the Path,
2150 * but all the list cells are freshly built, so it's safe to destructively
2151 * modify the lists (eg, by concat'ing with other lists).
2152 */
2153static void
2154find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
2155{
2156 if (IsA(bitmapqual, BitmapAndPath))
2157 {
2158 BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
2159 ListCell *l;
2160
2161 foreach(l, apath->bitmapquals)
2162 {
2163 find_indexpath_quals((Path *) lfirst(l), quals, preds);
2164 }
2165 }
2166 else if (IsA(bitmapqual, BitmapOrPath))
2167 {
2168 BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
2169 ListCell *l;
2170
2171 foreach(l, opath->bitmapquals)
2172 {
2173 find_indexpath_quals((Path *) lfirst(l), quals, preds);
2174 }
2175 }
2176 else if (IsA(bitmapqual, IndexPath))
2177 {
2178 IndexPath *ipath = (IndexPath *) bitmapqual;
2179 ListCell *l;
2180
2181 foreach(l, ipath->indexclauses)
2182 {
2183 IndexClause *iclause = (IndexClause *) lfirst(l);
2184
2185 *quals = lappend(*quals, iclause->rinfo->clause);
2186 }
2187 *preds = list_concat(*preds, ipath->indexinfo->indpred);
2188 }
2189 else
2190 elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
2191}
2192
2193
2194/*
2195 * find_list_position
2196 * Return the given node's position (counting from 0) in the given
2197 * list of nodes. If it's not equal() to any existing list member,
2198 * add it at the end, and return that position.
2199 */
2200static int
2201find_list_position(Node *node, List **nodelist)
2202{
2203 int i;
2204 ListCell *lc;
2205
2206 i = 0;
2207 foreach(lc, *nodelist)
2208 {
2209 Node *oldnode = (Node *) lfirst(lc);
2210
2211 if (equal(node, oldnode))
2212 return i;
2213 i++;
2214 }
2215
2216 *nodelist = lappend(*nodelist, node);
2217
2218 return i;
2219}
2220
2221
2222/*
2223 * check_index_only
2224 * Determine whether an index-only scan is possible for this index.
2225 */
2226static bool
2227check_index_only(RelOptInfo *rel, IndexOptInfo *index)
2228{
2229 bool result;
2230 Bitmapset *attrs_used = NULL;
2231 Bitmapset *index_canreturn_attrs = NULL;
2232 ListCell *lc;
2233 int i;
2234
2235 /* Index-only scans must be enabled */
2236 if (!enable_indexonlyscan)
2237 return false;
2238
2239 /*
2240 * Check that all needed attributes of the relation are available from the
2241 * index.
2242 */
2243
2244 /*
2245 * First, identify all the attributes needed for joins or final output.
2246 * Note: we must look at rel's targetlist, not the attr_needed data,
2247 * because attr_needed isn't computed for inheritance child rels.
2248 */
2249 pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
2250
2251 /*
2252 * Add all the attributes used by restriction clauses; but consider only
2253 * those clauses not implied by the index predicate, since ones that are
2254 * so implied don't need to be checked explicitly in the plan.
2255 *
2256 * Note: attributes used only in index quals would not be needed at
2257 * runtime either, if we are certain that the index is not lossy. However
2258 * it'd be complicated to account for that accurately, and it doesn't
2259 * matter in most cases, since we'd conclude that such attributes are
2260 * available from the index anyway.
2261 */
2262 foreach(lc, index->indrestrictinfo)
2263 {
2264 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2265
2266 pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
2267 }
2268
2269 /*
2270 * Construct a bitmapset of columns that the index can return back in an
2271 * index-only scan.
2272 */
2273 for (i = 0; i < index->ncolumns; i++)
2274 {
2275 int attno = index->indexkeys[i];
2276
2277 /*
2278 * For the moment, we just ignore index expressions. It might be nice
2279 * to do something with them, later.
2280 */
2281 if (attno == 0)
2282 continue;
2283
2284 if (index->canreturn[i])
2285 index_canreturn_attrs =
2286 bms_add_member(index_canreturn_attrs,
2287 attno - FirstLowInvalidHeapAttributeNumber);
2288 }
2289
2290 /* Do we have all the necessary attributes? */
2291 result = bms_is_subset(attrs_used, index_canreturn_attrs);
2292
2293 bms_free(attrs_used);
2294 bms_free(index_canreturn_attrs);
2295
2296 return result;
2297}
2298
2299/*
2300 * get_loop_count
2301 * Choose the loop count estimate to use for costing a parameterized path
2302 * with the given set of outer relids.
2303 *
2304 * Since we produce parameterized paths before we've begun to generate join
2305 * relations, it's impossible to predict exactly how many times a parameterized
2306 * path will be iterated; we don't know the size of the relation that will be
2307 * on the outside of the nestloop. However, we should try to account for
2308 * multiple iterations somehow in costing the path. The heuristic embodied
2309 * here is to use the rowcount of the smallest other base relation needed in
2310 * the join clauses used by the path. (We could alternatively consider the
2311 * largest one, but that seems too optimistic.) This is of course the right
2312 * answer for single-other-relation cases, and it seems like a reasonable
2313 * zero-order approximation for multiway-join cases.
2314 *
2315 * In addition, we check to see if the other side of each join clause is on
2316 * the inside of some semijoin that the current relation is on the outside of.
2317 * If so, the only way that a parameterized path could be used is if the
2318 * semijoin RHS has been unique-ified, so we should use the number of unique
2319 * RHS rows rather than using the relation's raw rowcount.
2320 *
2321 * Note: for this to work, allpaths.c must establish all baserel size
2322 * estimates before it begins to compute paths, or at least before it
2323 * calls create_index_paths().
2324 */
2325static double
2326get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
2327{
2328 double result;
2329 int outer_relid;
2330
2331 /* For a non-parameterized path, just return 1.0 quickly */
2332 if (outer_relids == NULL)
2333 return 1.0;
2334
2335 result = 0.0;
2336 outer_relid = -1;
2337 while ((outer_relid = bms_next_member(outer_relids, outer_relid)) >= 0)
2338 {
2339 RelOptInfo *outer_rel;
2340 double rowcount;
2341
2342 /* Paranoia: ignore bogus relid indexes */
2343 if (outer_relid >= root->simple_rel_array_size)
2344 continue;
2345 outer_rel = root->simple_rel_array[outer_relid];
2346 if (outer_rel == NULL)
2347 continue;
2348 Assert(outer_rel->relid == outer_relid); /* sanity check on array */
2349
2350 /* Other relation could be proven empty, if so ignore */
2351 if (IS_DUMMY_REL(outer_rel))
2352 continue;
2353
2354 /* Otherwise, rel's rows estimate should be valid by now */
2355 Assert(outer_rel->rows > 0);
2356
2357 /* Check to see if rel is on the inside of any semijoins */
2358 rowcount = adjust_rowcount_for_semijoins(root,
2359 cur_relid,
2360 outer_relid,
2361 outer_rel->rows);
2362
2363 /* Remember smallest row count estimate among the outer rels */
2364 if (result == 0.0 || result > rowcount)
2365 result = rowcount;
2366 }
2367 /* Return 1.0 if we found no valid relations (shouldn't happen) */
2368 return (result > 0.0) ? result : 1.0;
2369}
2370
2371/*
2372 * Check to see if outer_relid is on the inside of any semijoin that cur_relid
2373 * is on the outside of. If so, replace rowcount with the estimated number of
2374 * unique rows from the semijoin RHS (assuming that's smaller, which it might
2375 * not be). The estimate is crude but it's the best we can do at this stage
2376 * of the proceedings.
2377 */
2378static double
2379adjust_rowcount_for_semijoins(PlannerInfo *root,
2380 Index cur_relid,
2381 Index outer_relid,
2382 double rowcount)
2383{
2384 ListCell *lc;
2385
2386 foreach(lc, root->join_info_list)
2387 {
2388 SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
2389
2390 if (sjinfo->jointype == JOIN_SEMI &&
2391 bms_is_member(cur_relid, sjinfo->syn_lefthand) &&
2392 bms_is_member(outer_relid, sjinfo->syn_righthand))
2393 {
2394 /* Estimate number of unique-ified rows */
2395 double nraw;
2396 double nunique;
2397
2398 nraw = approximate_joinrel_size(root, sjinfo->syn_righthand);
2399 nunique = estimate_num_groups(root,
2400 sjinfo->semi_rhs_exprs,
2401 nraw,
2402 NULL,
2403 NULL);
2404 if (rowcount > nunique)
2405 rowcount = nunique;
2406 }
2407 }
2408 return rowcount;
2409}
2410
2411/*
2412 * Make an approximate estimate of the size of a joinrel.
2413 *
2414 * We don't have enough info at this point to get a good estimate, so we
2415 * just multiply the base relation sizes together. Fortunately, this is
2416 * the right answer anyway for the most common case with a single relation
2417 * on the RHS of a semijoin. Also, estimate_num_groups() has only a weak
2418 * dependency on its input_rows argument (it basically uses it as a clamp).
2419 * So we might be able to get a fairly decent end result even with a severe
2420 * overestimate of the RHS's raw size.
2421 */
2422static double
2423approximate_joinrel_size(PlannerInfo *root, Relids relids)
2424{
2425 double rowcount = 1.0;
2426 int relid;
2427
2428 relid = -1;
2429 while ((relid = bms_next_member(relids, relid)) >= 0)
2430 {
2431 RelOptInfo *rel;
2432
2433 /* Paranoia: ignore bogus relid indexes */
2434 if (relid >= root->simple_rel_array_size)
2435 continue;
2436 rel = root->simple_rel_array[relid];
2437 if (rel == NULL)
2438 continue;
2439 Assert(rel->relid == relid); /* sanity check on array */
2440
2441 /* Relation could be proven empty, if so ignore */
2442 if (IS_DUMMY_REL(rel))
2443 continue;
2444
2445 /* Otherwise, rel's rows estimate should be valid by now */
2446 Assert(rel->rows > 0);
2447
2448 /* Accumulate product */
2449 rowcount *= rel->rows;
2450 }
2451 return rowcount;
2452}
2453
2454
2455/****************************************************************************
2456 * ---- ROUTINES TO CHECK QUERY CLAUSES ----
2457 ****************************************************************************/
2458
2459/*
2460 * match_restriction_clauses_to_index
2461 * Identify restriction clauses for the rel that match the index.
2462 * Matching clauses are added to *clauseset.
2463 */
2464static void
2465match_restriction_clauses_to_index(PlannerInfo *root,
2466 IndexOptInfo *index,
2467 IndexClauseSet *clauseset)
2468{
2469 /* We can ignore clauses that are implied by the index predicate */
2470 match_clauses_to_index(root, index->indrestrictinfo, index, clauseset);
2471}
2472
2473/*
2474 * match_join_clauses_to_index
2475 * Identify join clauses for the rel that match the index.
2476 * Matching clauses are added to *clauseset.
2477 * Also, add any potentially usable join OR clauses to *joinorclauses.
2478 * They also might be processed by match_clause_to_index() as a whole.
2479 */
2480static void
2481match_join_clauses_to_index(PlannerInfo *root,
2482 RelOptInfo *rel, IndexOptInfo *index,
2483 IndexClauseSet *clauseset,
2484 List **joinorclauses)
2485{
2486 ListCell *lc;
2487
2488 /* Scan the rel's join clauses */
2489 foreach(lc, rel->joininfo)
2490 {
2491 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2492
2493 /* Check if clause can be moved to this rel */
2494 if (!join_clause_is_movable_to(rinfo, rel))
2495 continue;
2496
2497 /*
2498 * Potentially usable, so see if it matches the index or is an OR. Use
2499 * list_append_unique_ptr() here to avoid possible duplicates when
2500 * processing the same clauses with different indexes.
2501 */
2502 if (restriction_is_or_clause(rinfo))
2503 *joinorclauses = list_append_unique_ptr(*joinorclauses, rinfo);
2504
2505 match_clause_to_index(root, rinfo, index, clauseset);
2506 }
2507}
2508
2509/*
2510 * match_eclass_clauses_to_index
2511 * Identify EquivalenceClass join clauses for the rel that match the index.
2512 * Matching clauses are added to *clauseset.
2513 */
2514static void
2515match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index,
2516 IndexClauseSet *clauseset)
2517{
2518 int indexcol;
2519
2520 /* No work if rel is not in any such ECs */
2521 if (!index->rel->has_eclass_joins)
2522 return;
2523
2524 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2525 {
2526 ec_member_matches_arg arg;
2527 List *clauses;
2528
2529 /* Generate clauses, skipping any that join to lateral_referencers */
2530 arg.index = index;
2531 arg.indexcol = indexcol;
2532 clauses = generate_implied_equalities_for_column(root,
2533 index->rel,
2534 ec_member_matches_indexcol,
2535 &arg,
2536 index->rel->lateral_referencers);
2537
2538 /*
2539 * We have to check whether the results actually do match the index,
2540 * since for non-btree indexes the EC's equality operators might not
2541 * be in the index opclass (cf ec_member_matches_indexcol).
2542 */
2543 match_clauses_to_index(root, clauses, index, clauseset);
2544 }
2545}
2546
2547/*
2548 * match_clauses_to_index
2549 * Perform match_clause_to_index() for each clause in a list.
2550 * Matching clauses are added to *clauseset.
2551 */
2552static void
2553match_clauses_to_index(PlannerInfo *root,
2554 List *clauses,
2555 IndexOptInfo *index,
2556 IndexClauseSet *clauseset)
2557{
2558 ListCell *lc;
2559
2560 foreach(lc, clauses)
2561 {
2562 RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
2563
2564 match_clause_to_index(root, rinfo, index, clauseset);
2565 }
2566}
2567
2568/*
2569 * match_clause_to_index
2570 * Test whether a qual clause can be used with an index.
2571 *
2572 * If the clause is usable, add an IndexClause entry for it to the appropriate
2573 * list in *clauseset. (*clauseset must be initialized to zeroes before first
2574 * call.)
2575 *
2576 * Note: in some circumstances we may find the same RestrictInfos coming from
2577 * multiple places. Defend against redundant outputs by refusing to add a
2578 * clause twice (pointer equality should be a good enough check for this).
2579 *
2580 * Note: it's possible that a badly-defined index could have multiple matching
2581 * columns. We always select the first match if so; this avoids scenarios
2582 * wherein we get an inflated idea of the index's selectivity by using the
2583 * same clause multiple times with different index columns.
2584 */
2585static void
2586match_clause_to_index(PlannerInfo *root,
2587 RestrictInfo *rinfo,
2588 IndexOptInfo *index,
2589 IndexClauseSet *clauseset)
2590{
2591 int indexcol;
2592
2593 /*
2594 * Never match pseudoconstants to indexes. (Normally a match could not
2595 * happen anyway, since a pseudoconstant clause couldn't contain a Var,
2596 * but what if someone builds an expression index on a constant? It's not
2597 * totally unreasonable to do so with a partial index, either.)
2598 */
2599 if (rinfo->pseudoconstant)
2600 return;
2601
2602 /*
2603 * If clause can't be used as an indexqual because it must wait till after
2604 * some lower-security-level restriction clause, reject it.
2605 */
2606 if (!restriction_is_securely_promotable(rinfo, index->rel))
2607 return;
2608
2609 /* OK, check each index key column for a match */
2610 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2611 {
2612 IndexClause *iclause;
2613 ListCell *lc;
2614
2615 /* Ignore duplicates */
2616 foreach(lc, clauseset->indexclauses[indexcol])
2617 {
2618 iclause = (IndexClause *) lfirst(lc);
2619
2620 if (iclause->rinfo == rinfo)
2621 return;
2622 }
2623
2624 /* OK, try to match the clause to the index column */
2625 iclause = match_clause_to_indexcol(root,
2626 rinfo,
2627 indexcol,
2628 index);
2629 if (iclause)
2630 {
2631 /* Success, so record it */
2632 clauseset->indexclauses[indexcol] =
2633 lappend(clauseset->indexclauses[indexcol], iclause);
2634 clauseset->nonempty = true;
2635 return;
2636 }
2637 }
2638}
2639
2640/*
2641 * match_clause_to_indexcol()
2642 * Determine whether a restriction clause matches a column of an index,
2643 * and if so, build an IndexClause node describing the details.
2644 *
2645 * To match an index normally, an operator clause:
2646 *
2647 * (1) must be in the form (indexkey op const) or (const op indexkey);
2648 * and
2649 * (2) must contain an operator which is in the index's operator family
2650 * for this column; and
2651 * (3) must match the collation of the index, if collation is relevant.
2652 *
2653 * Our definition of "const" is exceedingly liberal: we allow anything that
2654 * doesn't involve a volatile function or a Var of the index's relation.
2655 * In particular, Vars belonging to other relations of the query are
2656 * accepted here, since a clause of that form can be used in a
2657 * parameterized indexscan. It's the responsibility of higher code levels
2658 * to manage restriction and join clauses appropriately.
2659 *
2660 * Note: we do need to check for Vars of the index's relation on the
2661 * "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
2662 * are not processable by a parameterized indexscan on a.f1, whereas
2663 * something like (a.f1 OP (b.f2 OP c.f3)) is.
2664 *
2665 * Presently, the executor can only deal with indexquals that have the
2666 * indexkey on the left, so we can only use clauses that have the indexkey
2667 * on the right if we can commute the clause to put the key on the left.
2668 * We handle that by generating an IndexClause with the correctly-commuted
2669 * opclause as a derived indexqual.
2670 *
2671 * If the index has a collation, the clause must have the same collation.
2672 * For collation-less indexes, we assume it doesn't matter; this is
2673 * necessary for cases like "hstore ? text", wherein hstore's operators
2674 * don't care about collation but the clause will get marked with a
2675 * collation anyway because of the text argument. (This logic is
2676 * embodied in the macro IndexCollMatchesExprColl.)
2677 *
2678 * It is also possible to match RowCompareExpr clauses to indexes (but
2679 * currently, only btree indexes handle this).
2680 *
2681 * It is also possible to match ScalarArrayOpExpr clauses to indexes, when
2682 * the clause is of the form "indexkey op ANY (arrayconst)".
2683 *
2684 * It is also possible to match a list of OR clauses if it might be
2685 * transformed into a single ScalarArrayOpExpr clause. On success,
2686 * the returning index clause will contain a transformed clause.
2687 *
2688 * For boolean indexes, it is also possible to match the clause directly
2689 * to the indexkey; or perhaps the clause is (NOT indexkey).
2690 *
2691 * And, last but not least, some operators and functions can be processed
2692 * to derive (typically lossy) indexquals from a clause that isn't in
2693 * itself indexable. If we see that any operand of an OpExpr or FuncExpr
2694 * matches the index key, and the function has a planner support function
2695 * attached to it, we'll invoke the support function to see if such an
2696 * indexqual can be built.
2697 *
2698 * 'rinfo' is the clause to be tested (as a RestrictInfo node).
2699 * 'indexcol' is a column number of 'index' (counting from 0).
2700 * 'index' is the index of interest.
2701 *
2702 * Returns an IndexClause if the clause can be used with this index key,
2703 * or NULL if not.
2704 *
2705 * NOTE: This routine always returns NULL if the clause is an AND clause.
2706 * Higher-level routines deal with OR and AND clauses. OR clause can be
2707 * matched as a whole by match_orclause_to_indexcol() though.
2708 */
2709static IndexClause *
2710match_clause_to_indexcol(PlannerInfo *root,
2711 RestrictInfo *rinfo,
2712 int indexcol,
2713 IndexOptInfo *index)
2714{
2715 IndexClause *iclause;
2716 Expr *clause = rinfo->clause;
2717 Oid opfamily;
2718
2719 Assert(indexcol < index->nkeycolumns);
2720
2721 /*
2722 * Historically this code has coped with NULL clauses. That's probably
2723 * not possible anymore, but we might as well continue to cope.
2724 */
2725 if (clause == NULL)
2726 return NULL;
2727
2728 /* First check for boolean-index cases. */
2729 opfamily = index->opfamily[indexcol];
2730 if (IsBooleanOpfamily(opfamily))
2731 {
2732 iclause = match_boolean_index_clause(root, rinfo, indexcol, index);
2733 if (iclause)
2734 return iclause;
2735 }
2736
2737 /*
2738 * Clause must be an opclause, funcclause, ScalarArrayOpExpr,
2739 * RowCompareExpr, or OR-clause that could be converted to SAOP. Or, if
2740 * the index supports it, we can handle IS NULL/NOT NULL clauses.
2741 */
2742 if (IsA(clause, OpExpr))
2743 {
2744 return match_opclause_to_indexcol(root, rinfo, indexcol, index);
2745 }
2746 else if (IsA(clause, FuncExpr))
2747 {
2748 return match_funcclause_to_indexcol(root, rinfo, indexcol, index);
2749 }
2750 else if (IsA(clause, ScalarArrayOpExpr))
2751 {
2752 return match_saopclause_to_indexcol(root, rinfo, indexcol, index);
2753 }
2754 else if (IsA(clause, RowCompareExpr))
2755 {
2756 return match_rowcompare_to_indexcol(root, rinfo, indexcol, index);
2757 }
2758 else if (restriction_is_or_clause(rinfo))
2759 {
2760 return match_orclause_to_indexcol(root, rinfo, indexcol, index);
2761 }
2762 else if (index->amsearchnulls && IsA(clause, NullTest))
2763 {
2764 NullTest *nt = (NullTest *) clause;
2765
2766 if (!nt->argisrow &&
2767 match_index_to_operand((Node *) nt->arg, indexcol, index))
2768 {
2769 iclause = makeNode(IndexClause);
2770 iclause->rinfo = rinfo;
2771 iclause->indexquals = list_make1(rinfo);
2772 iclause->lossy = false;
2773 iclause->indexcol = indexcol;
2774 iclause->indexcols = NIL;
2775 return iclause;
2776 }
2777 }
2778
2779 return NULL;
2780}
2781
2782/*
2783 * IsBooleanOpfamily
2784 * Detect whether an opfamily supports boolean equality as an operator.
2785 *
2786 * If the opfamily OID is in the range of built-in objects, we can rely
2787 * on hard-wired knowledge of which built-in opfamilies support this.
2788 * For extension opfamilies, there's no choice but to do a catcache lookup.
2789 */
2790static bool
2791IsBooleanOpfamily(Oid opfamily)
2792{
2793 if (opfamily < FirstNormalObjectId)
2794 return IsBuiltinBooleanOpfamily(opfamily);
2795 else
2796 return op_in_opfamily(BooleanEqualOperator, opfamily);
2797}
2798
2799/*
2800 * match_boolean_index_clause
2801 * Recognize restriction clauses that can be matched to a boolean index.
2802 *
2803 * The idea here is that, for an index on a boolean column that supports the
2804 * BooleanEqualOperator, we can transform a plain reference to the indexkey
2805 * into "indexkey = true", or "NOT indexkey" into "indexkey = false", etc,
2806 * so as to make the expression indexable using the index's "=" operator.
2807 * Since Postgres 8.1, we must do this because constant simplification does
2808 * the reverse transformation; without this code there'd be no way to use
2809 * such an index at all.
2810 *
2811 * This should be called only when IsBooleanOpfamily() recognizes the
2812 * index's operator family. We check to see if the clause matches the
2813 * index's key, and if so, build a suitable IndexClause.
2814 */
2815static IndexClause *
2816match_boolean_index_clause(PlannerInfo *root,
2817 RestrictInfo *rinfo,
2818 int indexcol,
2819 IndexOptInfo *index)
2820{
2821 Node *clause = (Node *) rinfo->clause;
2822 Expr *op = NULL;
2823
2824 /* Direct match? */
2825 if (match_index_to_operand(clause, indexcol, index))
2826 {
2827 /* convert to indexkey = TRUE */
2828 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2829 (Expr *) clause,
2830 (Expr *) makeBoolConst(true, false),
2831 InvalidOid, InvalidOid);
2832 }
2833 /* NOT clause? */
2834 else if (is_notclause(clause))
2835 {
2836 Node *arg = (Node *) get_notclausearg((Expr *) clause);
2837
2838 if (match_index_to_operand(arg, indexcol, index))
2839 {
2840 /* convert to indexkey = FALSE */
2841 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2842 (Expr *) arg,
2843 (Expr *) makeBoolConst(false, false),
2844 InvalidOid, InvalidOid);
2845 }
2846 }
2847
2848 /*
2849 * Since we only consider clauses at top level of WHERE, we can convert
2850 * indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
2851 * different meaning for NULL isn't important.
2852 */
2853 else if (clause && IsA(clause, BooleanTest))
2854 {
2855 BooleanTest *btest = (BooleanTest *) clause;
2856 Node *arg = (Node *) btest->arg;
2857
2858 if (btest->booltesttype == IS_TRUE &&
2859 match_index_to_operand(arg, indexcol, index))
2860 {
2861 /* convert to indexkey = TRUE */
2862 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2863 (Expr *) arg,
2864 (Expr *) makeBoolConst(true, false),
2865 InvalidOid, InvalidOid);
2866 }
2867 else if (btest->booltesttype == IS_FALSE &&
2868 match_index_to_operand(arg, indexcol, index))
2869 {
2870 /* convert to indexkey = FALSE */
2871 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2872 (Expr *) arg,
2873 (Expr *) makeBoolConst(false, false),
2874 InvalidOid, InvalidOid);
2875 }
2876 }
2877
2878 /*
2879 * If we successfully made an operator clause from the given qual, we must
2880 * wrap it in an IndexClause. It's not lossy.
2881 */
2882 if (op)
2883 {
2884 IndexClause *iclause = makeNode(IndexClause);
2885
2886 iclause->rinfo = rinfo;
2887 iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
2888 iclause->lossy = false;
2889 iclause->indexcol = indexcol;
2890 iclause->indexcols = NIL;
2891 return iclause;
2892 }
2893
2894 return NULL;
2895}
2896
2897/*
2898 * match_opclause_to_indexcol()
2899 * Handles the OpExpr case for match_clause_to_indexcol(),
2900 * which see for comments.
2901 */
2902static IndexClause *
2903match_opclause_to_indexcol(PlannerInfo *root,
2904 RestrictInfo *rinfo,
2905 int indexcol,
2906 IndexOptInfo *index)
2907{
2908 IndexClause *iclause;
2909 OpExpr *clause = (OpExpr *) rinfo->clause;
2910 Node *leftop,
2911 *rightop;
2912 Oid expr_op;
2913 Oid expr_coll;
2914 Index index_relid;
2915 Oid opfamily;
2916 Oid idxcollation;
2917
2918 /*
2919 * Only binary operators need apply. (In theory, a planner support
2920 * function could do something with a unary operator, but it seems
2921 * unlikely to be worth the cycles to check.)
2922 */
2923 if (list_length(clause->args) != 2)
2924 return NULL;
2925
2926 leftop = (Node *) linitial(clause->args);
2927 rightop = (Node *) lsecond(clause->args);
2928 expr_op = clause->opno;
2929 expr_coll = clause->inputcollid;
2930
2931 index_relid = index->rel->relid;
2932 opfamily = index->opfamily[indexcol];
2933 idxcollation = index->indexcollations[indexcol];
2934
2935 /*
2936 * Check for clauses of the form: (indexkey operator constant) or
2937 * (constant operator indexkey). See match_clause_to_indexcol's notes
2938 * about const-ness.
2939 *
2940 * Note that we don't ask the support function about clauses that don't
2941 * have one of these forms. Again, in principle it might be possible to
2942 * do something, but it seems unlikely to be worth the cycles to check.
2943 */
2944 if (match_index_to_operand(leftop, indexcol, index) &&
2945 !bms_is_member(index_relid, rinfo->right_relids) &&
2946 !contain_volatile_functions(rightop))
2947 {
2948 if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
2949 op_in_opfamily(expr_op, opfamily))
2950 {
2951 iclause = makeNode(IndexClause);
2952 iclause->rinfo = rinfo;
2953 iclause->indexquals = list_make1(rinfo);
2954 iclause->lossy = false;
2955 iclause->indexcol = indexcol;
2956 iclause->indexcols = NIL;
2957 return iclause;
2958 }
2959
2960 /*
2961 * If we didn't find a member of the index's opfamily, try the support
2962 * function for the operator's underlying function.
2963 */
2964 set_opfuncid(clause); /* make sure we have opfuncid */
2965 return get_index_clause_from_support(root,
2966 rinfo,
2967 clause->opfuncid,
2968 0, /* indexarg on left */
2969 indexcol,
2970 index);
2971 }
2972
2973 if (match_index_to_operand(rightop, indexcol, index) &&
2974 !bms_is_member(index_relid, rinfo->left_relids) &&
2975 !contain_volatile_functions(leftop))
2976 {
2977 if (IndexCollMatchesExprColl(idxcollation, expr_coll))
2978 {
2979 Oid comm_op = get_commutator(expr_op);
2980
2981 if (OidIsValid(comm_op) &&
2982 op_in_opfamily(comm_op, opfamily))
2983 {
2984 RestrictInfo *commrinfo;
2985
2986 /* Build a commuted OpExpr and RestrictInfo */
2987 commrinfo = commute_restrictinfo(rinfo, comm_op);
2988
2989 /* Make an IndexClause showing that as a derived qual */
2990 iclause = makeNode(IndexClause);
2991 iclause->rinfo = rinfo;
2992 iclause->indexquals = list_make1(commrinfo);
2993 iclause->lossy = false;
2994 iclause->indexcol = indexcol;
2995 iclause->indexcols = NIL;
2996 return iclause;
2997 }
2998 }
2999
3000 /*
3001 * If we didn't find a member of the index's opfamily, try the support
3002 * function for the operator's underlying function.
3003 */
3004 set_opfuncid(clause); /* make sure we have opfuncid */
3005 return get_index_clause_from_support(root,
3006 rinfo,
3007 clause->opfuncid,
3008 1, /* indexarg on right */
3009 indexcol,
3010 index);
3011 }
3012
3013 return NULL;
3014}
3015
3016/*
3017 * match_funcclause_to_indexcol()
3018 * Handles the FuncExpr case for match_clause_to_indexcol(),
3019 * which see for comments.
3020 */
3021static IndexClause *
3022match_funcclause_to_indexcol(PlannerInfo *root,
3023 RestrictInfo *rinfo,
3024 int indexcol,
3025 IndexOptInfo *index)
3026{
3027 FuncExpr *clause = (FuncExpr *) rinfo->clause;
3028 int indexarg;
3029 ListCell *lc;
3030
3031 /*
3032 * We have no built-in intelligence about function clauses, but if there's
3033 * a planner support function, it might be able to do something. But, to
3034 * cut down on wasted planning cycles, only call the support function if
3035 * at least one argument matches the target index column.
3036 *
3037 * Note that we don't insist on the other arguments being pseudoconstants;
3038 * the support function has to check that. This is to allow cases where
3039 * only some of the other arguments need to be included in the indexqual.
3040 */
3041 indexarg = 0;
3042 foreach(lc, clause->args)
3043 {
3044 Node *op = (Node *) lfirst(lc);
3045
3046 if (match_index_to_operand(op, indexcol, index))
3047 {
3048 return get_index_clause_from_support(root,
3049 rinfo,
3050 clause->funcid,
3051 indexarg,
3052 indexcol,
3053 index);
3054 }
3055
3056 indexarg++;
3057 }
3058
3059 return NULL;
3060}
3061
3062/*
3063 * get_index_clause_from_support()
3064 * If the function has a planner support function, try to construct
3065 * an IndexClause using indexquals created by the support function.
3066 */
3067static IndexClause *
3068get_index_clause_from_support(PlannerInfo *root,
3069 RestrictInfo *rinfo,
3070 Oid funcid,
3071 int indexarg,
3072 int indexcol,
3073 IndexOptInfo *index)
3074{
3075 Oid prosupport = get_func_support(funcid);
3076 SupportRequestIndexCondition req;
3077 List *sresult;
3078
3079 if (!OidIsValid(prosupport))
3080 return NULL;
3081
3082 req.type = T_SupportRequestIndexCondition;
3083 req.root = root;
3084 req.funcid = funcid;
3085 req.node = (Node *) rinfo->clause;
3086 req.indexarg = indexarg;
3087 req.index = index;
3088 req.indexcol = indexcol;
3089 req.opfamily = index->opfamily[indexcol];
3090 req.indexcollation = index->indexcollations[indexcol];
3091
3092 req.lossy = true; /* default assumption */
3093
3094 sresult = (List *)
3095 DatumGetPointer(OidFunctionCall1(prosupport,
3096 PointerGetDatum(&req)));
3097
3098 if (sresult != NIL)
3099 {
3100 IndexClause *iclause = makeNode(IndexClause);
3101 List *indexquals = NIL;
3102 ListCell *lc;
3103
3104 /*
3105 * The support function API says it should just give back bare
3106 * clauses, so here we must wrap each one in a RestrictInfo.
3107 */
3108 foreach(lc, sresult)
3109 {
3110 Expr *clause = (Expr *) lfirst(lc);
3111
3112 indexquals = lappend(indexquals,
3113 make_simple_restrictinfo(root, clause));
3114 }
3115
3116 iclause->rinfo = rinfo;
3117 iclause->indexquals = indexquals;
3118 iclause->lossy = req.lossy;
3119 iclause->indexcol = indexcol;
3120 iclause->indexcols = NIL;
3121
3122 return iclause;
3123 }
3124
3125 return NULL;
3126}
3127
3128/*
3129 * match_saopclause_to_indexcol()
3130 * Handles the ScalarArrayOpExpr case for match_clause_to_indexcol(),
3131 * which see for comments.
3132 */
3133static IndexClause *
3134match_saopclause_to_indexcol(PlannerInfo *root,
3135 RestrictInfo *rinfo,
3136 int indexcol,
3137 IndexOptInfo *index)
3138{
3139 ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
3140 Node *leftop,
3141 *rightop;
3142 Relids right_relids;
3143 Oid expr_op;
3144 Oid expr_coll;
3145 Index index_relid;
3146 Oid opfamily;
3147 Oid idxcollation;
3148
3149 /* We only accept ANY clauses, not ALL */
3150 if (!saop->useOr)
3151 return NULL;
3152 leftop = (Node *) linitial(saop->args);
3153 rightop = (Node *) lsecond(saop->args);
3154 right_relids = pull_varnos(root, rightop);
3155 expr_op = saop->opno;
3156 expr_coll = saop->inputcollid;
3157
3158 index_relid = index->rel->relid;
3159 opfamily = index->opfamily[indexcol];
3160 idxcollation = index->indexcollations[indexcol];
3161
3162 /*
3163 * We must have indexkey on the left and a pseudo-constant array argument.
3164 */
3165 if (match_index_to_operand(leftop, indexcol, index) &&
3166 !bms_is_member(index_relid, right_relids) &&
3167 !contain_volatile_functions(rightop))
3168 {
3169 if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
3170 op_in_opfamily(expr_op, opfamily))
3171 {
3172 IndexClause *iclause = makeNode(IndexClause);
3173
3174 iclause->rinfo = rinfo;
3175 iclause->indexquals = list_make1(rinfo);
3176 iclause->lossy = false;
3177 iclause->indexcol = indexcol;
3178 iclause->indexcols = NIL;
3179 return iclause;
3180 }
3181
3182 /*
3183 * We do not currently ask support functions about ScalarArrayOpExprs,
3184 * though in principle we could.
3185 */
3186 }
3187
3188 return NULL;
3189}
3190
3191/*
3192 * match_rowcompare_to_indexcol()
3193 * Handles the RowCompareExpr case for match_clause_to_indexcol(),
3194 * which see for comments.
3195 *
3196 * In this routine we check whether the first column of the row comparison
3197 * matches the target index column. This is sufficient to guarantee that some
3198 * index condition can be constructed from the RowCompareExpr --- the rest
3199 * is handled by expand_indexqual_rowcompare().
3200 */
3201static IndexClause *
3202match_rowcompare_to_indexcol(PlannerInfo *root,
3203 RestrictInfo *rinfo,
3204 int indexcol,
3205 IndexOptInfo *index)
3206{
3207 RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3208 Index index_relid;
3209 Oid opfamily;
3210 Oid idxcollation;
3211 Node *leftop,
3212 *rightop;
3213 bool var_on_left;
3214 Oid expr_op;
3215 Oid expr_coll;
3216
3217 /* Forget it if we're not dealing with a btree index */
3218 if (index->relam != BTREE_AM_OID)
3219 return NULL;
3220
3221 index_relid = index->rel->relid;
3222 opfamily = index->opfamily[indexcol];
3223 idxcollation = index->indexcollations[indexcol];
3224
3225 /*
3226 * We could do the matching on the basis of insisting that the opfamily
3227 * shown in the RowCompareExpr be the same as the index column's opfamily,
3228 * but that could fail in the presence of reverse-sort opfamilies: it'd be
3229 * a matter of chance whether RowCompareExpr had picked the forward or
3230 * reverse-sort family. So look only at the operator, and match if it is
3231 * a member of the index's opfamily (after commutation, if the indexkey is
3232 * on the right). We'll worry later about whether any additional
3233 * operators are matchable to the index.
3234 */
3235 leftop = (Node *) linitial(clause->largs);
3236 rightop = (Node *) linitial(clause->rargs);
3237 expr_op = linitial_oid(clause->opnos);
3238 expr_coll = linitial_oid(clause->inputcollids);
3239
3240 /* Collations must match, if relevant */
3241 if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3242 return NULL;
3243
3244 /*
3245 * These syntactic tests are the same as in match_opclause_to_indexcol()
3246 */
3247 if (match_index_to_operand(leftop, indexcol, index) &&
3248 !bms_is_member(index_relid, pull_varnos(root, rightop)) &&
3249 !contain_volatile_functions(rightop))
3250 {
3251 /* OK, indexkey is on left */
3252 var_on_left = true;
3253 }
3254 else if (match_index_to_operand(rightop, indexcol, index) &&
3255 !bms_is_member(index_relid, pull_varnos(root, leftop)) &&
3256 !contain_volatile_functions(leftop))
3257 {
3258 /* indexkey is on right, so commute the operator */
3259 expr_op = get_commutator(expr_op);
3260 if (expr_op == InvalidOid)
3261 return NULL;
3262 var_on_left = false;
3263 }
3264 else
3265 return NULL;
3266
3267 /* We're good if the operator is the right type of opfamily member */
3268 switch (get_op_opfamily_strategy(expr_op, opfamily))
3269 {
3270 case BTLessStrategyNumber:
3271 case BTLessEqualStrategyNumber:
3272 case BTGreaterEqualStrategyNumber:
3273 case BTGreaterStrategyNumber:
3274 return expand_indexqual_rowcompare(root,
3275 rinfo,
3276 indexcol,
3277 index,
3278 expr_op,
3279 var_on_left);
3280 }
3281
3282 return NULL;
3283}
3284
3285/*
3286 * match_orclause_to_indexcol()
3287 * Handles the OR-expr case for match_clause_to_indexcol() in the case
3288 * when it could be transformed to ScalarArrayOpExpr.
3289 *
3290 * In this routine, we attempt to transform a list of OR-clause args into a
3291 * single SAOP expression matching the target index column. On success,
3292 * return an IndexClause containing the transformed expression.
3293 * Return NULL if the transformation fails.
3294 */
3295static IndexClause *
3296match_orclause_to_indexcol(PlannerInfo *root,
3297 RestrictInfo *rinfo,
3298 int indexcol,
3299 IndexOptInfo *index)
3300{
3301 BoolExpr *orclause = (BoolExpr *) rinfo->orclause;
3302 List *consts = NIL;
3303 Node *indexExpr = NULL;
3304 Oid matchOpno = InvalidOid;
3305 Oid consttype = InvalidOid;
3306 Oid arraytype = InvalidOid;
3307 Oid inputcollid = InvalidOid;
3308 bool firstTime = true;
3309 bool haveNonConst = false;
3310 Index indexRelid = index->rel->relid;
3311 ScalarArrayOpExpr *saopexpr;
3312 IndexClause *iclause;
3313 ListCell *lc;
3314
3315 /* Forget it if index doesn't support SAOP clauses */
3316 if (!index->amsearcharray)
3317 return NULL;
3318
3319 /*
3320 * Try to convert a list of OR-clauses to a single SAOP expression. Each
3321 * OR entry must be in the form: (indexkey operator constant) or (constant
3322 * operator indexkey). Operators of all the entries must match. On
3323 * discovery of anything unsupported, we give up by breaking out of the
3324 * loop immediately and returning NULL.
3325 */
3326 foreach(lc, orclause->args)
3327 {
3328 RestrictInfo *subRinfo = (RestrictInfo *) lfirst(lc);
3329 OpExpr *subClause;
3330 Oid opno;
3331 Node *leftop,
3332 *rightop;
3333 Node *constExpr;
3334
3335 /* If it's not a RestrictInfo (i.e. it's a sub-AND), we can't use it */
3336 if (!IsA(subRinfo, RestrictInfo))
3337 break;
3338
3339 /* Only operator clauses can match */
3340 if (!IsA(subRinfo->clause, OpExpr))
3341 break;
3342
3343 subClause = (OpExpr *) subRinfo->clause;
3344 opno = subClause->opno;
3345
3346 /* Only binary operators can match */
3347 if (list_length(subClause->args) != 2)
3348 break;
3349
3350 /*
3351 * Check for clauses of the form: (indexkey operator constant) or
3352 * (constant operator indexkey). These tests should agree with
3353 * match_opclause_to_indexcol.
3354 */
3355 leftop = (Node *) linitial(subClause->args);
3356 rightop = (Node *) lsecond(subClause->args);
3357 if (match_index_to_operand(leftop, indexcol, index) &&
3358 !bms_is_member(indexRelid, subRinfo->right_relids) &&
3359 !contain_volatile_functions(rightop))
3360 {
3361 indexExpr = leftop;
3362 constExpr = rightop;
3363 }
3364 else if (match_index_to_operand(rightop, indexcol, index) &&
3365 !bms_is_member(indexRelid, subRinfo->left_relids) &&
3366 !contain_volatile_functions(leftop))
3367 {
3368 opno = get_commutator(opno);
3369 if (!OidIsValid(opno))
3370 {
3371 /* commutator doesn't exist, we can't reverse the order */
3372 break;
3373 }
3374 indexExpr = rightop;
3375 constExpr = leftop;
3376 }
3377 else
3378 {
3379 break;
3380 }
3381
3382 /*
3383 * Save information about the operator, type, and collation for the
3384 * first matching qual. Then, check that subsequent quals match the
3385 * first.
3386 */
3387 if (firstTime)
3388 {
3389 matchOpno = opno;
3390 consttype = exprType(constExpr);
3391 arraytype = get_array_type(consttype);
3392 inputcollid = subClause->inputcollid;
3393
3394 /*
3395 * Check that the operator is presented in the opfamily and that
3396 * the expression collation matches the index collation. Also,
3397 * there must be an array type to construct an array later.
3398 */
3399 if (!IndexCollMatchesExprColl(index->indexcollations[indexcol],
3400 inputcollid) ||
3401 !op_in_opfamily(matchOpno, index->opfamily[indexcol]) ||
3402 !OidIsValid(arraytype))
3403 break;
3404
3405 /*
3406 * Disallow if either type is RECORD, mainly because we can't be
3407 * positive that all the RHS expressions are the same record type.
3408 */
3409 if (consttype == RECORDOID || exprType(indexExpr) == RECORDOID)
3410 break;
3411
3412 firstTime = false;
3413 }
3414 else
3415 {
3416 if (matchOpno != opno ||
3417 inputcollid != subClause->inputcollid ||
3418 consttype != exprType(constExpr))
3419 break;
3420 }
3421
3422 /*
3423 * The righthand inputs don't necessarily have to be plain Consts, but
3424 * make_SAOP_expr needs to know if any are not.
3425 */
3426 if (!IsA(constExpr, Const))
3427 haveNonConst = true;
3428
3429 consts = lappend(consts, constExpr);
3430 }
3431
3432 /*
3433 * Handle failed conversion from breaking out of the loop because of an
3434 * unsupported qual. Also check that we have an indexExpr, just in case
3435 * the OR list was somehow empty (it shouldn't be). Return NULL to
3436 * indicate the conversion failed.
3437 */
3438 if (lc != NULL || indexExpr == NULL)
3439 {
3440 list_free(consts); /* might as well */
3441 return NULL;
3442 }
3443
3444 /*
3445 * Build the new SAOP node. We use the indexExpr from the last OR arm;
3446 * since all the arms passed match_index_to_operand, it shouldn't matter
3447 * which one we use. But using "inputcollid" twice is a bit of a cheat:
3448 * we might end up with an array Const node that is labeled with a
3449 * collation despite its elements being of a noncollatable type. But
3450 * nothing is likely to complain about that, so we don't bother being more
3451 * accurate.
3452 */
3453 saopexpr = make_SAOP_expr(matchOpno, indexExpr, consttype, inputcollid,
3454 inputcollid, consts, haveNonConst);
3455 Assert(saopexpr != NULL);
3456
3457 /*
3458 * Finally, build an IndexClause based on the SAOP node. It's not lossy.
3459 */
3460 iclause = makeNode(IndexClause);
3461 iclause->rinfo = rinfo;
3462 iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3463 (Expr *) saopexpr));
3464 iclause->lossy = false;
3465 iclause->indexcol = indexcol;
3466 iclause->indexcols = NIL;
3467 return iclause;
3468}
3469
3470/*
3471 * expand_indexqual_rowcompare --- expand a single indexqual condition
3472 * that is a RowCompareExpr
3473 *
3474 * It's already known that the first column of the row comparison matches
3475 * the specified column of the index. We can use additional columns of the
3476 * row comparison as index qualifications, so long as they match the index
3477 * in the "same direction", ie, the indexkeys are all on the same side of the
3478 * clause and the operators are all the same-type members of the opfamilies.
3479 *
3480 * If all the columns of the RowCompareExpr match in this way, we just use it
3481 * as-is, except for possibly commuting it to put the indexkeys on the left.
3482 *
3483 * Otherwise, we build a shortened RowCompareExpr (if more than one
3484 * column matches) or a simple OpExpr (if the first-column match is all
3485 * there is). In these cases the modified clause is always "<=" or ">="
3486 * even when the original was "<" or ">" --- this is necessary to match all
3487 * the rows that could match the original. (We are building a lossy version
3488 * of the row comparison when we do this, so we set lossy = true.)
3489 *
3490 * Note: this is really just the last half of match_rowcompare_to_indexcol,
3491 * but we split it out for comprehensibility.
3492 */
3493static IndexClause *
3494expand_indexqual_rowcompare(PlannerInfo *root,
3495 RestrictInfo *rinfo,
3496 int indexcol,
3497 IndexOptInfo *index,
3498 Oid expr_op,
3499 bool var_on_left)
3500{
3501 IndexClause *iclause = makeNode(IndexClause);
3502 RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3503 int op_strategy;
3504 Oid op_lefttype;
3505 Oid op_righttype;
3506 int matching_cols;
3507 List *expr_ops;
3508 List *opfamilies;
3509 List *lefttypes;
3510 List *righttypes;
3511 List *new_ops;
3512 List *var_args;
3513 List *non_var_args;
3514
3515 iclause->rinfo = rinfo;
3516 iclause->indexcol = indexcol;
3517
3518 if (var_on_left)
3519 {
3520 var_args = clause->largs;
3521 non_var_args = clause->rargs;
3522 }
3523 else
3524 {
3525 var_args = clause->rargs;
3526 non_var_args = clause->largs;
3527 }
3528
3529 get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
3530 &op_strategy,
3531 &op_lefttype,
3532 &op_righttype);
3533
3534 /* Initialize returned list of which index columns are used */
3535 iclause->indexcols = list_make1_int(indexcol);
3536
3537 /* Build lists of ops, opfamilies and operator datatypes in case needed */
3538 expr_ops = list_make1_oid(expr_op);
3539 opfamilies = list_make1_oid(index->opfamily[indexcol]);
3540 lefttypes = list_make1_oid(op_lefttype);
3541 righttypes = list_make1_oid(op_righttype);
3542
3543 /*
3544 * See how many of the remaining columns match some index column in the
3545 * same way. As in match_clause_to_indexcol(), the "other" side of any
3546 * potential index condition is OK as long as it doesn't use Vars from the
3547 * indexed relation.
3548 */
3549 matching_cols = 1;
3550
3551 while (matching_cols < list_length(var_args))
3552 {
3553 Node *varop = (Node *) list_nth(var_args, matching_cols);
3554 Node *constop = (Node *) list_nth(non_var_args, matching_cols);
3555 int i;
3556
3557 expr_op = list_nth_oid(clause->opnos, matching_cols);
3558 if (!var_on_left)
3559 {
3560 /* indexkey is on right, so commute the operator */
3561 expr_op = get_commutator(expr_op);
3562 if (expr_op == InvalidOid)
3563 break; /* operator is not usable */
3564 }
3565 if (bms_is_member(index->rel->relid, pull_varnos(root, constop)))
3566 break; /* no good, Var on wrong side */
3567 if (contain_volatile_functions(constop))
3568 break; /* no good, volatile comparison value */
3569
3570 /*
3571 * The Var side can match any key column of the index.
3572 */
3573 for (i = 0; i < index->nkeycolumns; i++)
3574 {
3575 if (match_index_to_operand(varop, i, index) &&
3576 get_op_opfamily_strategy(expr_op,
3577 index->opfamily[i]) == op_strategy &&
3578 IndexCollMatchesExprColl(index->indexcollations[i],
3579 list_nth_oid(clause->inputcollids,
3580 matching_cols)))
3581 break;
3582 }
3583 if (i >= index->nkeycolumns)
3584 break; /* no match found */
3585
3586 /* Add column number to returned list */
3587 iclause->indexcols = lappend_int(iclause->indexcols, i);
3588
3589 /* Add operator info to lists */
3590 get_op_opfamily_properties(expr_op, index->opfamily[i], false,
3591 &op_strategy,
3592 &op_lefttype,
3593 &op_righttype);
3594 expr_ops = lappend_oid(expr_ops, expr_op);
3595 opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
3596 lefttypes = lappend_oid(lefttypes, op_lefttype);
3597 righttypes = lappend_oid(righttypes, op_righttype);
3598
3599 /* This column matches, keep scanning */
3600 matching_cols++;
3601 }
3602
3603 /* Result is non-lossy if all columns are usable as index quals */
3604 iclause->lossy = (matching_cols != list_length(clause->opnos));
3605
3606 /*
3607 * We can use rinfo->clause as-is if we have var on left and it's all
3608 * usable as index quals.
3609 */
3610 if (var_on_left && !iclause->lossy)
3611 iclause->indexquals = list_make1(rinfo);
3612 else
3613 {
3614 /*
3615 * We have to generate a modified rowcompare (possibly just one
3616 * OpExpr). The painful part of this is changing < to <= or > to >=,
3617 * so deal with that first.
3618 */
3619 if (!iclause->lossy)
3620 {
3621 /* very easy, just use the commuted operators */
3622 new_ops = expr_ops;
3623 }
3624 else if (op_strategy == BTLessEqualStrategyNumber ||
3625 op_strategy == BTGreaterEqualStrategyNumber)
3626 {
3627 /* easy, just use the same (possibly commuted) operators */
3628 new_ops = list_truncate(expr_ops, matching_cols);
3629 }
3630 else
3631 {
3632 ListCell *opfamilies_cell;
3633 ListCell *lefttypes_cell;
3634 ListCell *righttypes_cell;
3635
3636 if (op_strategy == BTLessStrategyNumber)
3637 op_strategy = BTLessEqualStrategyNumber;
3638 else if (op_strategy == BTGreaterStrategyNumber)
3639 op_strategy = BTGreaterEqualStrategyNumber;
3640 else
3641 elog(ERROR, "unexpected strategy number %d", op_strategy);
3642 new_ops = NIL;
3643 forthree(opfamilies_cell, opfamilies,
3644 lefttypes_cell, lefttypes,
3645 righttypes_cell, righttypes)
3646 {
3647 Oid opfam = lfirst_oid(opfamilies_cell);
3648 Oid lefttype = lfirst_oid(lefttypes_cell);
3649 Oid righttype = lfirst_oid(righttypes_cell);
3650
3651 expr_op = get_opfamily_member(opfam, lefttype, righttype,
3652 op_strategy);
3653 if (!OidIsValid(expr_op)) /* should not happen */
3654 elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3655 op_strategy, lefttype, righttype, opfam);
3656 new_ops = lappend_oid(new_ops, expr_op);
3657 }
3658 }
3659
3660 /* If we have more than one matching col, create a subset rowcompare */
3661 if (matching_cols > 1)
3662 {
3663 RowCompareExpr *rc = makeNode(RowCompareExpr);
3664
3665 rc->cmptype = (CompareType) op_strategy;
3666 rc->opnos = new_ops;
3667 rc->opfamilies = list_copy_head(clause->opfamilies,
3668 matching_cols);
3669 rc->inputcollids = list_copy_head(clause->inputcollids,
3670 matching_cols);
3671 rc->largs = list_copy_head(var_args, matching_cols);
3672 rc->rargs = list_copy_head(non_var_args, matching_cols);
3673 iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3674 (Expr *) rc));
3675 }
3676 else
3677 {
3678 Expr *op;
3679
3680 /* We don't report an index column list in this case */
3681 iclause->indexcols = NIL;
3682
3683 op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
3684 copyObject(linitial(var_args)),
3685 copyObject(linitial(non_var_args)),
3686 InvalidOid,
3687 linitial_oid(clause->inputcollids));
3688 iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
3689 }
3690 }
3691
3692 return iclause;
3693}
3694
3695
3696/****************************************************************************
3697 * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3698 ****************************************************************************/
3699
3700/*
3701 * match_pathkeys_to_index
3702 * For the given 'index' and 'pathkeys', output a list of suitable ORDER
3703 * BY expressions, each of the form "indexedcol operator pseudoconstant",
3704 * along with an integer list of the index column numbers (zero based)
3705 * that each clause would be used with.
3706 *
3707 * This attempts to find an ORDER BY and index column number for all items in
3708 * the pathkey list, however, if we're unable to match any given pathkey to an
3709 * index column, we return just the ones matched by the function so far. This
3710 * allows callers who are interested in partial matches to get them. Callers
3711 * can determine a partial match vs a full match by checking the outputted
3712 * list lengths. A full match will have one item in the output lists for each
3713 * item in the given 'pathkeys' list.
3714 */
3715static void
3716match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3717 List **orderby_clauses_p,
3718 List **clause_columns_p)
3719{
3720 ListCell *lc1;
3721
3722 *orderby_clauses_p = NIL; /* set default results */
3723 *clause_columns_p = NIL;
3724
3725 /* Only indexes with the amcanorderbyop property are interesting here */
3726 if (!index->amcanorderbyop)
3727 return;
3728
3729 foreach(lc1, pathkeys)
3730 {
3731 PathKey *pathkey = (PathKey *) lfirst(lc1);
3732 bool found = false;
3733 EquivalenceMemberIterator it;
3734 EquivalenceMember *member;
3735
3736
3737 /* Pathkey must request default sort order for the target opfamily */
3738 if (pathkey->pk_cmptype != COMPARE_LT || pathkey->pk_nulls_first)
3739 return;
3740
3741 /* If eclass is volatile, no hope of using an indexscan */
3742 if (pathkey->pk_eclass->ec_has_volatile)
3743 return;
3744
3745 /*
3746 * Try to match eclass member expression(s) to index. Note that child
3747 * EC members are considered, but only when they belong to the target
3748 * relation. (Unlike regular members, the same expression could be a
3749 * child member of more than one EC. Therefore, the same index could
3750 * be considered to match more than one pathkey list, which is OK
3751 * here. See also get_eclass_for_sort_expr.)
3752 */
3753 setup_eclass_member_iterator(&it, pathkey->pk_eclass,
3754 index->rel->relids);
3755 while ((member = eclass_member_iterator_next(&it)) != NULL)
3756 {
3757 int indexcol;
3758
3759 /* No possibility of match if it references other relations */
3760 if (!bms_equal(member->em_relids, index->rel->relids))
3761 continue;
3762
3763 /*
3764 * We allow any column of the index to match each pathkey; they
3765 * don't have to match left-to-right as you might expect. This is
3766 * correct for GiST, and it doesn't matter for SP-GiST because
3767 * that doesn't handle multiple columns anyway, and no other
3768 * existing AMs support amcanorderbyop. We might need different
3769 * logic in future for other implementations.
3770 */
3771 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3772 {
3773 Expr *expr;
3774
3775 expr = match_clause_to_ordering_op(index,
3776 indexcol,
3777 member->em_expr,
3778 pathkey->pk_opfamily);
3779 if (expr)
3780 {
3781 *orderby_clauses_p = lappend(*orderby_clauses_p, expr);
3782 *clause_columns_p = lappend_int(*clause_columns_p, indexcol);
3783 found = true;
3784 break;
3785 }
3786 }
3787
3788 if (found) /* don't want to look at remaining members */
3789 break;
3790 }
3791
3792 /*
3793 * Return the matches found so far when this pathkey couldn't be
3794 * matched to the index.
3795 */
3796 if (!found)
3797 return;
3798 }
3799}
3800
3801/*
3802 * match_clause_to_ordering_op
3803 * Determines whether an ordering operator expression matches an
3804 * index column.
3805 *
3806 * This is similar to, but simpler than, match_clause_to_indexcol.
3807 * We only care about simple OpExpr cases. The input is a bare
3808 * expression that is being ordered by, which must be of the form
3809 * (indexkey op const) or (const op indexkey) where op is an ordering
3810 * operator for the column's opfamily.
3811 *
3812 * 'index' is the index of interest.
3813 * 'indexcol' is a column number of 'index' (counting from 0).
3814 * 'clause' is the ordering expression to be tested.
3815 * 'pk_opfamily' is the btree opfamily describing the required sort order.
3816 *
3817 * Note that we currently do not consider the collation of the ordering
3818 * operator's result. In practical cases the result type will be numeric
3819 * and thus have no collation, and it's not very clear what to match to
3820 * if it did have a collation. The index's collation should match the
3821 * ordering operator's input collation, not its result.
3822 *
3823 * If successful, return 'clause' as-is if the indexkey is on the left,
3824 * otherwise a commuted copy of 'clause'. If no match, return NULL.
3825 */
3826static Expr *
3827match_clause_to_ordering_op(IndexOptInfo *index,
3828 int indexcol,
3829 Expr *clause,
3830 Oid pk_opfamily)
3831{
3832 Oid opfamily;
3833 Oid idxcollation;
3834 Node *leftop,
3835 *rightop;
3836 Oid expr_op;
3837 Oid expr_coll;
3838 Oid sortfamily;
3839 bool commuted;
3840
3841 Assert(indexcol < index->nkeycolumns);
3842
3843 opfamily = index->opfamily[indexcol];
3844 idxcollation = index->indexcollations[indexcol];
3845
3846 /*
3847 * Clause must be a binary opclause.
3848 */
3849 if (!is_opclause(clause))
3850 return NULL;
3851 leftop = get_leftop(clause);
3852 rightop = get_rightop(clause);
3853 if (!leftop || !rightop)
3854 return NULL;
3855 expr_op = ((OpExpr *) clause)->opno;
3856 expr_coll = ((OpExpr *) clause)->inputcollid;
3857
3858 /*
3859 * We can forget the whole thing right away if wrong collation.
3860 */
3861 if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3862 return NULL;
3863
3864 /*
3865 * Check for clauses of the form: (indexkey operator constant) or
3866 * (constant operator indexkey).
3867 */
3868 if (match_index_to_operand(leftop, indexcol, index) &&
3869 !contain_var_clause(rightop) &&
3870 !contain_volatile_functions(rightop))
3871 {
3872 commuted = false;
3873 }
3874 else if (match_index_to_operand(rightop, indexcol, index) &&
3875 !contain_var_clause(leftop) &&
3876 !contain_volatile_functions(leftop))
3877 {
3878 /* Might match, but we need a commuted operator */
3879 expr_op = get_commutator(expr_op);
3880 if (expr_op == InvalidOid)
3881 return NULL;
3882 commuted = true;
3883 }
3884 else
3885 return NULL;
3886
3887 /*
3888 * Is the (commuted) operator an ordering operator for the opfamily? And
3889 * if so, does it yield the right sorting semantics?
3890 */
3891 sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3892 if (sortfamily != pk_opfamily)
3893 return NULL;
3894
3895 /* We have a match. Return clause or a commuted version thereof. */
3896 if (commuted)
3897 {
3898 OpExpr *newclause = makeNode(OpExpr);
3899
3900 /* flat-copy all the fields of clause */
3901 memcpy(newclause, clause, sizeof(OpExpr));
3902
3903 /* commute it */
3904 newclause->opno = expr_op;
3905 newclause->opfuncid = InvalidOid;
3906 newclause->args = list_make2(rightop, leftop);
3907
3908 clause = (Expr *) newclause;
3909 }
3910
3911 return clause;
3912}
3913
3914
3915/****************************************************************************
3916 * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3917 ****************************************************************************/
3918
3919/*
3920 * check_index_predicates
3921 * Set the predicate-derived IndexOptInfo fields for each index
3922 * of the specified relation.
3923 *
3924 * predOK is set true if the index is partial and its predicate is satisfied
3925 * for this query, ie the query's WHERE clauses imply the predicate.
3926 *
3927 * indrestrictinfo is set to the relation's baserestrictinfo list less any
3928 * conditions that are implied by the index's predicate. (Obviously, for a
3929 * non-partial index, this is the same as baserestrictinfo.) Such conditions
3930 * can be dropped from the plan when using the index, in certain cases.
3931 *
3932 * At one time it was possible for this to get re-run after adding more
3933 * restrictions to the rel, thus possibly letting us prove more indexes OK.
3934 * That doesn't happen any more (at least not in the core code's usage),
3935 * but this code still supports it in case extensions want to mess with the
3936 * baserestrictinfo list. We assume that adding more restrictions can't make
3937 * an index not predOK. We must recompute indrestrictinfo each time, though,
3938 * to make sure any newly-added restrictions get into it if needed.
3939 */
3940void
3941check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3942{
3943 List *clauselist;
3944 bool have_partial;
3945 bool is_target_rel;
3946 Relids otherrels;
3947 ListCell *lc;
3948
3949 /* Indexes are available only on base or "other" member relations. */
3950 Assert(IS_SIMPLE_REL(rel));
3951
3952 /*
3953 * Initialize the indrestrictinfo lists to be identical to
3954 * baserestrictinfo, and check whether there are any partial indexes. If
3955 * not, this is all we need to do.
3956 */
3957 have_partial = false;
3958 foreach(lc, rel->indexlist)
3959 {
3960 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3961
3962 index->indrestrictinfo = rel->baserestrictinfo;
3963 if (index->indpred)
3964 have_partial = true;
3965 }
3966 if (!have_partial)
3967 return;
3968
3969 /*
3970 * Construct a list of clauses that we can assume true for the purpose of
3971 * proving the index(es) usable. Restriction clauses for the rel are
3972 * always usable, and so are any join clauses that are "movable to" this
3973 * rel. Also, we can consider any EC-derivable join clauses (which must
3974 * be "movable to" this rel, by definition).
3975 */
3976 clauselist = list_copy(rel->baserestrictinfo);
3977
3978 /* Scan the rel's join clauses */
3979 foreach(lc, rel->joininfo)
3980 {
3981 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3982
3983 /* Check if clause can be moved to this rel */
3984 if (!join_clause_is_movable_to(rinfo, rel))
3985 continue;
3986
3987 clauselist = lappend(clauselist, rinfo);
3988 }
3989
3990 /*
3991 * Add on any equivalence-derivable join clauses. Computing the correct
3992 * relid sets for generate_join_implied_equalities is slightly tricky
3993 * because the rel could be a child rel rather than a true baserel, and in
3994 * that case we must subtract its parents' relid(s) from all_query_rels.
3995 * Additionally, we mustn't consider clauses that are only computable
3996 * after outer joins that can null the rel.
3997 */
3998 if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3999 otherrels = bms_difference(root->all_query_rels,
4000 find_childrel_parents(root, rel));
4001 else
4002 otherrels = bms_difference(root->all_query_rels, rel->relids);
4003 otherrels = bms_del_members(otherrels, rel->nulling_relids);
4004
4005 if (!bms_is_empty(otherrels))
4006 clauselist =
4007 list_concat(clauselist,
4008 generate_join_implied_equalities(root,
4009 bms_union(rel->relids,
4010 otherrels),
4011 otherrels,
4012 rel,
4013 NULL));
4014
4015 /*
4016 * Normally we remove quals that are implied by a partial index's
4017 * predicate from indrestrictinfo, indicating that they need not be
4018 * checked explicitly by an indexscan plan using this index. However, if
4019 * the rel is a target relation of UPDATE/DELETE/MERGE/SELECT FOR UPDATE,
4020 * we cannot remove such quals from the plan, because they need to be in
4021 * the plan so that they will be properly rechecked by EvalPlanQual
4022 * testing. Some day we might want to remove such quals from the main
4023 * plan anyway and pass them through to EvalPlanQual via a side channel;
4024 * but for now, we just don't remove implied quals at all for target
4025 * relations.
4026 */
4027 is_target_rel = (bms_is_member(rel->relid, root->all_result_relids) ||
4028 get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
4029
4030 /*
4031 * Now try to prove each index predicate true, and compute the
4032 * indrestrictinfo lists for partial indexes. Note that we compute the
4033 * indrestrictinfo list even for non-predOK indexes; this might seem
4034 * wasteful, but we may be able to use such indexes in OR clauses, cf
4035 * generate_bitmap_or_paths().
4036 */
4037 foreach(lc, rel->indexlist)
4038 {
4039 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
4040 ListCell *lcr;
4041
4042 if (index->indpred == NIL)
4043 continue; /* ignore non-partial indexes here */
4044
4045 if (!index->predOK) /* don't repeat work if already proven OK */
4046 index->predOK = predicate_implied_by(index->indpred, clauselist,
4047 false);
4048
4049 /* If rel is an update target, leave indrestrictinfo as set above */
4050 if (is_target_rel)
4051 continue;
4052
4053 /*
4054 * If index is !amoptionalkey, also leave indrestrictinfo as set
4055 * above. Otherwise we risk removing all quals for the first index
4056 * key and then not being able to generate an indexscan at all. It
4057 * would be better to be more selective, but we've not yet identified
4058 * which if any of the quals match the first index key.
4059 */
4060 if (!index->amoptionalkey)
4061 continue;
4062
4063 /* Else compute indrestrictinfo as the non-implied quals */
4064 index->indrestrictinfo = NIL;
4065 foreach(lcr, rel->baserestrictinfo)
4066 {
4067 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
4068
4069 /* predicate_implied_by() assumes first arg is immutable */
4070 if (contain_mutable_functions((Node *) rinfo->clause) ||
4071 !predicate_implied_by(list_make1(rinfo->clause),
4072 index->indpred, false))
4073 index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
4074 }
4075 }
4076}
4077
4078/****************************************************************************
4079 * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
4080 ****************************************************************************/
4081
4082/*
4083 * ec_member_matches_indexcol
4084 * Test whether an EquivalenceClass member matches an index column.
4085 *
4086 * This is a callback for use by generate_implied_equalities_for_column.
4087 */
4088static bool
4089ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
4090 EquivalenceClass *ec, EquivalenceMember *em,
4091 void *arg)
4092{
4093 IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
4094 int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
4095 Oid curFamily;
4096 Oid curCollation;
4097
4098 Assert(indexcol < index->nkeycolumns);
4099
4100 curFamily = index->opfamily[indexcol];
4101 curCollation = index->indexcollations[indexcol];
4102
4103 /*
4104 * If it's a btree index, we can reject it if its opfamily isn't
4105 * compatible with the EC, since no clause generated from the EC could be
4106 * used with the index. For non-btree indexes, we can't easily tell
4107 * whether clauses generated from the EC could be used with the index, so
4108 * don't check the opfamily. This might mean we return "true" for a
4109 * useless EC, so we have to recheck the results of
4110 * generate_implied_equalities_for_column; see
4111 * match_eclass_clauses_to_index.
4112 */
4113 if (index->relam == BTREE_AM_OID &&
4114 !list_member_oid(ec->ec_opfamilies, curFamily))
4115 return false;
4116
4117 /* We insist on collation match for all index types, though */
4118 if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
4119 return false;
4120
4121 return match_index_to_operand((Node *) em->em_expr, indexcol, index);
4122}
4123
4124/*
4125 * relation_has_unique_index_for
4126 * Determine whether the relation provably has at most one row satisfying
4127 * a set of equality conditions, because the conditions constrain all
4128 * columns of some unique index.
4129 *
4130 * The conditions are provided as a list of RestrictInfo nodes, where the
4131 * caller has already determined that each condition is a mergejoinable
4132 * equality with an expression in this relation on one side, and an
4133 * expression not involving this relation on the other. The transient
4134 * outer_is_left flag is used to identify which side we should look at:
4135 * left side if outer_is_left is false, right side if it is true.
4136 *
4137 * The caller need only supply equality conditions arising from joins;
4138 * this routine automatically adds in any usable baserestrictinfo clauses.
4139 * (Note that the passed-in restrictlist will be destructively modified!)
4140 *
4141 * If extra_clauses isn't NULL, return baserestrictinfo clauses which were used
4142 * to derive uniqueness.
4143 */
4144bool
4145relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
4146 List *restrictlist, List **extra_clauses)
4147{
4148 ListCell *ic;
4149
4150 /* Short-circuit if no indexes... */
4151 if (rel->indexlist == NIL)
4152 return false;
4153
4154 /*
4155 * Examine the rel's restriction clauses for usable var = const clauses
4156 * that we can add to the restrictlist.
4157 */
4158 foreach(ic, rel->baserestrictinfo)
4159 {
4160 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
4161
4162 /*
4163 * Note: can_join won't be set for a restriction clause, but
4164 * mergeopfamilies will be if it has a mergejoinable operator and
4165 * doesn't contain volatile functions.
4166 */
4167 if (restrictinfo->mergeopfamilies == NIL)
4168 continue; /* not mergejoinable */
4169
4170 /*
4171 * The clause certainly doesn't refer to anything but the given rel.
4172 * If either side is pseudoconstant then we can use it.
4173 */
4174 if (bms_is_empty(restrictinfo->left_relids))
4175 {
4176 /* righthand side is inner */
4177 restrictinfo->outer_is_left = true;
4178 }
4179 else if (bms_is_empty(restrictinfo->right_relids))
4180 {
4181 /* lefthand side is inner */
4182 restrictinfo->outer_is_left = false;
4183 }
4184 else
4185 continue;
4186
4187 /* OK, add to list */
4188 restrictlist = lappend(restrictlist, restrictinfo);
4189 }
4190
4191 /* Short-circuit the easy case */
4192 if (restrictlist == NIL)
4193 return false;
4194
4195 /* Examine each index of the relation ... */
4196 foreach(ic, rel->indexlist)
4197 {
4198 IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
4199 int c;
4200 List *exprs = NIL;
4201
4202 /*
4203 * If the index is not unique, or not immediately enforced, or if it's
4204 * a partial index, it's useless here. We're unable to make use of
4205 * predOK partial unique indexes due to the fact that
4206 * check_index_predicates() also makes use of join predicates to
4207 * determine if the partial index is usable. Here we need proofs that
4208 * hold true before any joins are evaluated.
4209 */
4210 if (!ind->unique || !ind->immediate || ind->indpred != NIL)
4211 continue;
4212
4213 /*
4214 * Try to find each index column in the list of conditions. This is
4215 * O(N^2) or worse, but we expect all the lists to be short.
4216 */
4217 for (c = 0; c < ind->nkeycolumns; c++)
4218 {
4219 ListCell *lc;
4220
4221 foreach(lc, restrictlist)
4222 {
4223 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4224 Node *rexpr;
4225
4226 /*
4227 * The condition's equality operator must be a member of the
4228 * index opfamily, else it is not asserting the right kind of
4229 * equality behavior for this index. We check this first
4230 * since it's probably cheaper than match_index_to_operand().
4231 */
4232 if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
4233 continue;
4234
4235 /*
4236 * XXX at some point we may need to check collations here too.
4237 * For the moment we assume all collations reduce to the same
4238 * notion of equality.
4239 */
4240
4241 /* OK, see if the condition operand matches the index key */
4242 if (rinfo->outer_is_left)
4243 rexpr = get_rightop(rinfo->clause);
4244 else
4245 rexpr = get_leftop(rinfo->clause);
4246
4247 if (match_index_to_operand(rexpr, c, ind))
4248 {
4249 if (bms_membership(rinfo->clause_relids) == BMS_SINGLETON)
4250 {
4251 MemoryContext oldMemCtx =
4252 MemoryContextSwitchTo(root->planner_cxt);
4253
4254 /*
4255 * Add filter clause into a list allowing caller to
4256 * know if uniqueness have made not only by join
4257 * clauses.
4258 */
4259 Assert(bms_is_empty(rinfo->left_relids) ||
4260 bms_is_empty(rinfo->right_relids));
4261 if (extra_clauses)
4262 exprs = lappend(exprs, rinfo);
4263 MemoryContextSwitchTo(oldMemCtx);
4264 }
4265
4266 break; /* found a match; column is unique */
4267 }
4268 }
4269
4270 if (lc == NULL)
4271 break; /* no match; this index doesn't help us */
4272 }
4273
4274 /* Matched all key columns of this index? */
4275 if (c == ind->nkeycolumns)
4276 {
4277 if (extra_clauses)
4278 *extra_clauses = exprs;
4279 return true;
4280 }
4281 }
4282
4283 return false;
4284}
4285
4286/*
4287 * indexcol_is_bool_constant_for_query
4288 *
4289 * If an index column is constrained to have a constant value by the query's
4290 * WHERE conditions, then it's irrelevant for sort-order considerations.
4291 * Usually that means we have a restriction clause WHERE indexcol = constant,
4292 * which gets turned into an EquivalenceClass containing a constant, which
4293 * is recognized as redundant by build_index_pathkeys(). But if the index
4294 * column is a boolean variable (or expression), then we are not going to
4295 * see WHERE indexcol = constant, because expression preprocessing will have
4296 * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
4297 * going to have a matching EquivalenceClass (unless the query also contains
4298 * "ORDER BY indexcol"). To allow such cases to work the same as they would
4299 * for non-boolean values, this function is provided to detect whether the
4300 * specified index column matches a boolean restriction clause.
4301 */
4302bool
4303indexcol_is_bool_constant_for_query(PlannerInfo *root,
4304 IndexOptInfo *index,
4305 int indexcol)
4306{
4307 ListCell *lc;
4308
4309 /* If the index isn't boolean, we can't possibly get a match */
4310 if (!IsBooleanOpfamily(index->opfamily[indexcol]))
4311 return false;
4312
4313 /* Check each restriction clause for the index's rel */
4314 foreach(lc, index->rel->baserestrictinfo)
4315 {
4316 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4317
4318 /*
4319 * As in match_clause_to_indexcol, never match pseudoconstants to
4320 * indexes. (It might be semantically okay to do so here, but the
4321 * odds of getting a match are negligible, so don't waste the cycles.)
4322 */
4323 if (rinfo->pseudoconstant)
4324 continue;
4325
4326 /* See if we can match the clause's expression to the index column */
4327 if (match_boolean_index_clause(root, rinfo, indexcol, index))
4328 return true;
4329 }
4330
4331 return false;
4332}
4333
4334
4335/****************************************************************************
4336 * ---- ROUTINES TO CHECK OPERANDS ----
4337 ****************************************************************************/
4338
4339/*
4340 * match_index_to_operand()
4341 * Generalized test for a match between an index's key
4342 * and the operand on one side of a restriction or join clause.
4343 *
4344 * operand: the nodetree to be compared to the index
4345 * indexcol: the column number of the index (counting from 0)
4346 * index: the index of interest
4347 *
4348 * Note that we aren't interested in collations here; the caller must check
4349 * for a collation match, if it's dealing with an operator where that matters.
4350 *
4351 * This is exported for use in selfuncs.c.
4352 */
4353bool
4354match_index_to_operand(Node *operand,
4355 int indexcol,
4356 IndexOptInfo *index)
4357{
4358 int indkey;
4359
4360 /*
4361 * Ignore any PlaceHolderVar node contained in the operand. This is
4362 * needed to be able to apply indexscanning in cases where the operand (or
4363 * a subtree) has been wrapped in PlaceHolderVars to enforce separate
4364 * identity or as a result of outer joins.
4365 */
4366 operand = strip_phvs_in_index_operand(operand);
4367
4368 /*
4369 * Ignore any RelabelType node above the operand. This is needed to be
4370 * able to apply indexscanning in binary-compatible-operator cases.
4371 *
4372 * Note: we must handle nested RelabelType nodes here. While
4373 * eval_const_expressions() will have simplified them to at most one
4374 * layer, our prior stripping of PlaceHolderVars may have brought separate
4375 * RelabelTypes into adjacency.
4376 */
4377 while (operand && IsA(operand, RelabelType))
4378 operand = (Node *) ((RelabelType *) operand)->arg;
4379
4380 indkey = index->indexkeys[indexcol];
4381 if (indkey != 0)
4382 {
4383 /*
4384 * Simple index column; operand must be a matching Var.
4385 */
4386 if (operand && IsA(operand, Var) &&
4387 index->rel->relid == ((Var *) operand)->varno &&
4388 indkey == ((Var *) operand)->varattno &&
4389 ((Var *) operand)->varnullingrels == NULL)
4390 return true;
4391 }
4392 else
4393 {
4394 /*
4395 * Index expression; find the correct expression. (This search could
4396 * be avoided, at the cost of complicating all the callers of this
4397 * routine; doesn't seem worth it.)
4398 */
4399 ListCell *indexpr_item;
4400 int i;
4401 Node *indexkey;
4402
4403 indexpr_item = list_head(index->indexprs);
4404 for (i = 0; i < indexcol; i++)
4405 {
4406 if (index->indexkeys[i] == 0)
4407 {
4408 if (indexpr_item == NULL)
4409 elog(ERROR, "wrong number of index expressions");
4410 indexpr_item = lnext(index->indexprs, indexpr_item);
4411 }
4412 }
4413 if (indexpr_item == NULL)
4414 elog(ERROR, "wrong number of index expressions");
4415 indexkey = (Node *) lfirst(indexpr_item);
4416
4417 /*
4418 * Does it match the operand? Again, strip any relabeling.
4419 */
4420 if (indexkey && IsA(indexkey, RelabelType))
4421 indexkey = (Node *) ((RelabelType *) indexkey)->arg;
4422
4423 if (equal(indexkey, operand))
4424 return true;
4425 }
4426
4427 return false;
4428}
4429
4430/*
4431 * strip_phvs_in_index_operand
4432 * Strip PlaceHolderVar nodes from the given operand expression to
4433 * facilitate matching against an index's key.
4434 *
4435 * A PlaceHolderVar appearing in a relation-scan-level expression is
4436 * effectively a no-op. Nevertheless, to play it safe, we strip only
4437 * PlaceHolderVars that are not marked nullable.
4438 *
4439 * The removal is performed recursively because PlaceHolderVars can be nested
4440 * or interleaved with other node types. We must peel back all layers to
4441 * expose the base operand.
4442 *
4443 * As a performance optimization, we first use a lightweight walker to check
4444 * for the presence of strippable PlaceHolderVars. The expensive mutator is
4445 * invoked only if a candidate is found, avoiding unnecessary memory allocation
4446 * and tree copying in the common case where no PlaceHolderVars are present.
4447 */
4448Node *
4449strip_phvs_in_index_operand(Node *operand)
4450{
4451 /* Don't mutate/copy if no target PHVs exist */
4452 if (!contain_strippable_phv_walker(operand, NULL))
4453 return operand;
4454
4455 return strip_phvs_in_index_operand_mutator(operand, NULL);
4456}
4457
4458/*
4459 * contain_strippable_phv_walker
4460 * Detect if there are any PlaceHolderVars in the tree that are candidates
4461 * for stripping.
4462 *
4463 * We identify a PlaceHolderVar as strippable only if its phnullingrels is
4464 * empty.
4465 */
4466static bool
4467contain_strippable_phv_walker(Node *node, void *context)
4468{
4469 if (node == NULL)
4470 return false;
4471
4472 if (IsA(node, PlaceHolderVar))
4473 {
4474 PlaceHolderVar *phv = (PlaceHolderVar *) node;
4475
4476 if (bms_is_empty(phv->phnullingrels))
4477 return true;
4478 }
4479
4480 return expression_tree_walker(node, contain_strippable_phv_walker,
4481 context);
4482}
4483
4484/*
4485 * strip_phvs_in_index_operand_mutator
4486 * Recursively remove PlaceHolderVars in the tree that match the criteria.
4487 *
4488 * We strip a PlaceHolderVar only if its phnullingrels is empty, replacing it
4489 * with its contained expression.
4490 */
4491static Node *
4492strip_phvs_in_index_operand_mutator(Node *node, void *context)
4493{
4494 if (node == NULL)
4495 return NULL;
4496
4497 if (IsA(node, PlaceHolderVar))
4498 {
4499 PlaceHolderVar *phv = (PlaceHolderVar *) node;
4500
4501 /* If matches the criteria, strip it */
4502 if (bms_is_empty(phv->phnullingrels))
4503 {
4504 /* Recurse on its contained expression */
4505 return strip_phvs_in_index_operand_mutator((Node *) phv->phexpr,
4506 context);
4507 }
4508
4509 /* Otherwise, keep this PHV but check its contained expression */
4510 }
4511
4512 return expression_tree_mutator(node, strip_phvs_in_index_operand_mutator,
4513 context);
4514}
4515
4516/*
4517 * is_pseudo_constant_for_index()
4518 * Test whether the given expression can be used as an indexscan
4519 * comparison value.
4520 *
4521 * An indexscan comparison value must not contain any volatile functions,
4522 * and it can't contain any Vars of the index's own table. Vars of
4523 * other tables are okay, though; in that case we'd be producing an
4524 * indexqual usable in a parameterized indexscan. This is, therefore,
4525 * a weaker condition than is_pseudo_constant_clause().
4526 *
4527 * This function is exported for use by planner support functions,
4528 * which will have available the IndexOptInfo, but not any RestrictInfo
4529 * infrastructure. It is making the same test made by functions above
4530 * such as match_opclause_to_indexcol(), but those rely where possible
4531 * on RestrictInfo information about variable membership.
4532 *
4533 * expr: the nodetree to be checked
4534 * index: the index of interest
4535 */
4536bool
4537is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
4538{
4539 /* pull_varnos is cheaper than volatility check, so do that first */
4540 if (bms_is_member(index->rel->relid, pull_varnos(root, expr)))
4541 return false; /* no good, contains Var of table */
4542 if (contain_volatile_functions(expr))
4543 return false; /* no good, volatile comparison value */
4544 return true;
4545}
create_partial_bitmap_paths
void create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual)
Definition allpaths.c:4690
bms_difference
Bitmapset * bms_difference(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:346
bms_equal
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:142
bms_subset_compare
BMS_Comparison bms_subset_compare(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:445
bms_next_member
int bms_next_member(const Bitmapset *a, int prevbit)
Definition bitmapset.c:1305
bms_del_members
Bitmapset * bms_del_members(Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:1160
bms_del_member
Bitmapset * bms_del_member(Bitmapset *a, int x)
Definition bitmapset.c:867
bms_is_subset
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:412
bms_free
void bms_free(Bitmapset *a)
Definition bitmapset.c:239
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:814
bms_add_members
Bitmapset * bms_add_members(Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:916
bms_union
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:251
bms_membership
BMS_Membership bms_membership(const Bitmapset *a)
Definition bitmapset.c:780
bms_overlap
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:581
bms_copy
Bitmapset * bms_copy(const Bitmapset *a)
Definition bitmapset.c:122
bms_is_empty
#define bms_is_empty(a)
Definition bitmapset.h:118
BMS_DIFFERENT
@ BMS_DIFFERENT
Definition bitmapset.h:65
BMS_SINGLETON
@ BMS_SINGLETON
Definition bitmapset.h:72
Assert
#define Assert(condition)
Definition c.h:873
Index
unsigned int Index
Definition c.h:628
MemSet
#define MemSet(start, val, len)
Definition c.h:1013
OidIsValid
#define OidIsValid(objectId)
Definition c.h:788
contain_mutable_functions
bool contain_mutable_functions(Node *clause)
Definition clauses.c:379
make_SAOP_expr
ScalarArrayOpExpr * make_SAOP_expr(Oid oper, Node *leftexpr, Oid coltype, Oid arraycollid, Oid inputcollid, List *exprs, bool haveNonConst)
Definition clauses.c:5832
contain_volatile_functions
bool contain_volatile_functions(Node *clause)
Definition clauses.c:547
CompareType
CompareType
Definition cmptype.h:32
COMPARE_LT
@ COMPARE_LT
Definition cmptype.h:34
cost_bitmap_tree_node
void cost_bitmap_tree_node(Path *path, Cost *cost, Selectivity *selec)
Definition costsize.c:1096
cost_bitmap_heap_scan
void cost_bitmap_heap_scan(Path *path, PlannerInfo *root, RelOptInfo *baserel, ParamPathInfo *param_info, Path *bitmapqual, double loop_count)
Definition costsize.c:997
enable_indexonlyscan
bool enable_indexonlyscan
Definition costsize.c:147
ERROR
#define ERROR
Definition elog.h:39
elog
#define elog(elevel,...)
Definition elog.h:226
equal
bool equal(const void *a, const void *b)
Definition equalfuncs.c:223
setup_eclass_member_iterator
void setup_eclass_member_iterator(EquivalenceMemberIterator *it, EquivalenceClass *ec, Relids child_relids)
Definition equivclass.c:3155
generate_implied_equalities_for_column
List * generate_implied_equalities_for_column(PlannerInfo *root, RelOptInfo *rel, ec_matches_callback_type callback, void *callback_arg, Relids prohibited_rels)
Definition equivclass.c:3238
eclass_member_iterator_next
EquivalenceMember * eclass_member_iterator_next(EquivalenceMemberIterator *it)
Definition equivclass.c:3174
generate_join_implied_equalities
List * generate_join_implied_equalities(PlannerInfo *root, Relids join_relids, Relids outer_relids, RelOptInfo *inner_rel, SpecialJoinInfo *sjinfo)
Definition equivclass.c:1549
palloc_object
#define palloc_object(type)
Definition fe_memutils.h:74
palloc_array
#define palloc_array(type, count)
Definition fe_memutils.h:76
OidFunctionCall1
#define OidFunctionCall1(functionId, arg1)
Definition fmgr.h:722
IsBooleanOpfamily
static bool IsBooleanOpfamily(Oid opfamily)
Definition indxpath.c:2791
choose_bitmap_and
static Path * choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
Definition indxpath.c:1785
bitmap_and_cost_est
static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
Definition indxpath.c:2057
find_indexpath_quals
static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
Definition indxpath.c:2154
get_join_index_paths
static void get_join_index_paths(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *rclauseset, IndexClauseSet *jclauseset, IndexClauseSet *eclauseset, List **bitindexpaths, Relids relids, List **considered_relids)
Definition indxpath.c:606
or_arg_index_match_cmp
static int or_arg_index_match_cmp(const void *a, const void *b)
Definition indxpath.c:1200
match_clause_to_index
static void match_clause_to_index(PlannerInfo *root, RestrictInfo *rinfo, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2586
is_pseudo_constant_for_index
bool is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
Definition indxpath.c:4537
eclass_already_used
static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids, List *indexjoinclauses)
Definition indxpath.c:684
match_join_clauses_to_index
static void match_join_clauses_to_index(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *clauseset, List **joinorclauses)
Definition indxpath.c:2481
match_saopclause_to_indexcol
static IndexClause * match_saopclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3134
check_index_only
static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index)
Definition indxpath.c:2227
match_eclass_clauses_to_index
static void match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2515
ScanTypeControl
ScanTypeControl
Definition indxpath.c:45
ST_ANYSCAN
@ ST_ANYSCAN
Definition indxpath.c:48
ST_BITMAPSCAN
@ ST_BITMAPSCAN
Definition indxpath.c:47
ST_INDEXSCAN
@ ST_INDEXSCAN
Definition indxpath.c:46
classify_index_clause_usage
static PathClauseUsage * classify_index_clause_usage(Path *path, List **clauselist)
Definition indxpath.c:2086
get_index_paths
static void get_index_paths(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *clauses, List **bitindexpaths)
Definition indxpath.c:716
strip_phvs_in_index_operand
Node * strip_phvs_in_index_operand(Node *operand)
Definition indxpath.c:4449
check_index_predicates
void check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
Definition indxpath.c:3941
build_index_paths
static List * build_index_paths(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *clauses, bool useful_predicate, ScanTypeControl scantype, bool *skip_nonnative_saop)
Definition indxpath.c:810
match_pathkeys_to_index
static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys, List **orderby_clauses_p, List **clause_columns_p)
Definition indxpath.c:3716
find_list_position
static int find_list_position(Node *node, List **nodelist)
Definition indxpath.c:2201
match_clauses_to_index
static void match_clauses_to_index(PlannerInfo *root, List *clauses, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2553
get_loop_count
static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
Definition indxpath.c:2326
consider_index_join_outer_rels
static void consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *rclauseset, IndexClauseSet *jclauseset, IndexClauseSet *eclauseset, List **bitindexpaths, List *indexjoinclauses, int considered_clauses, List **considered_relids)
Definition indxpath.c:503
create_index_paths
void create_index_paths(PlannerInfo *root, RelOptInfo *rel)
Definition indxpath.c:240
adjust_rowcount_for_semijoins
static double adjust_rowcount_for_semijoins(PlannerInfo *root, Index cur_relid, Index outer_relid, double rowcount)
Definition indxpath.c:2379
match_clause_to_indexcol
static IndexClause * match_clause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:2710
ec_member_matches_indexcol
static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg)
Definition indxpath.c:4089
get_index_clause_from_support
static IndexClause * get_index_clause_from_support(PlannerInfo *root, RestrictInfo *rinfo, Oid funcid, int indexarg, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3068
IndexCollMatchesExprColl
#define IndexCollMatchesExprColl(idxcollation, exprcollation)
Definition indxpath.c:40
match_orclause_to_indexcol
static IndexClause * match_orclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3296
match_opclause_to_indexcol
static IndexClause * match_opclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:2903
bitmap_scan_cost_est
static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
Definition indxpath.c:2023
match_index_to_operand
bool match_index_to_operand(Node *operand, int indexcol, IndexOptInfo *index)
Definition indxpath.c:4354
match_boolean_index_clause
static IndexClause * match_boolean_index_clause(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:2816
consider_index_join_clauses
static void consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *rclauseset, IndexClauseSet *jclauseset, IndexClauseSet *eclauseset, List **bitindexpaths)
Definition indxpath.c:437
or_arg_index_match_cmp_group
static int or_arg_index_match_cmp_group(const void *a, const void *b)
Definition indxpath.c:1238
strip_phvs_in_index_operand_mutator
static Node * strip_phvs_in_index_operand_mutator(Node *node, void *context)
Definition indxpath.c:4492
expand_indexqual_rowcompare
static IndexClause * expand_indexqual_rowcompare(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index, Oid expr_op, bool var_on_left)
Definition indxpath.c:3494
match_restriction_clauses_to_index
static void match_restriction_clauses_to_index(PlannerInfo *root, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2465
match_rowcompare_to_indexcol
static IndexClause * match_rowcompare_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3202
build_paths_for_OR
static List * build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel, List *clauses, List *other_clauses)
Definition indxpath.c:1092
indexcol_is_bool_constant_for_query
bool indexcol_is_bool_constant_for_query(PlannerInfo *root, IndexOptInfo *index, int indexcol)
Definition indxpath.c:4303
match_funcclause_to_indexcol
static IndexClause * match_funcclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3022
path_usage_comparator
static int path_usage_comparator(const void *a, const void *b)
Definition indxpath.c:1990
contain_strippable_phv_walker
static bool contain_strippable_phv_walker(Node *node, void *context)
Definition indxpath.c:4467
group_similar_or_args
static List * group_similar_or_args(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *rinfo)
Definition indxpath.c:1271
approximate_joinrel_size
static double approximate_joinrel_size(PlannerInfo *root, Relids relids)
Definition indxpath.c:2423
match_clause_to_ordering_op
static Expr * match_clause_to_ordering_op(IndexOptInfo *index, int indexcol, Expr *clause, Oid pk_opfamily)
Definition indxpath.c:3827
relation_has_unique_index_for
bool relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel, List *restrictlist, List **extra_clauses)
Definition indxpath.c:4145
generate_bitmap_or_paths
static List * generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel, List *clauses, List *other_clauses)
Definition indxpath.c:1629
make_bitmap_paths_for_or_group
static List * make_bitmap_paths_for_or_group(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *ri, List *other_clauses)
Definition indxpath.c:1548
b
int b
Definition isn.c:74
a
int a
Definition isn.c:73
j
int j
Definition isn.c:78
i
int i
Definition isn.c:77
lappend
List * lappend(List *list, void *datum)
Definition list.c:339
list_delete
List * list_delete(List *list, void *datum)
Definition list.c:853
list_append_unique
List * list_append_unique(List *list, void *datum)
Definition list.c:1343
list_concat
List * list_concat(List *list1, const List *list2)
Definition list.c:561
list_concat_copy
List * list_concat_copy(const List *list1, const List *list2)
Definition list.c:598
list_copy
List * list_copy(const List *oldlist)
Definition list.c:1573
lappend_int
List * lappend_int(List *list, int datum)
Definition list.c:357
lappend_oid
List * lappend_oid(List *list, Oid datum)
Definition list.c:375
list_free
void list_free(List *list)
Definition list.c:1546
list_member_oid
bool list_member_oid(const List *list, Oid datum)
Definition list.c:722
list_truncate
List * list_truncate(List *list, int new_size)
Definition list.c:631
list_member
bool list_member(const List *list, const void *datum)
Definition list.c:661
list_copy_head
List * list_copy_head(const List *oldlist, int len)
Definition list.c:1593
list_append_unique_ptr
List * list_append_unique_ptr(List *list, void *datum)
Definition list.c:1356
get_op_opfamily_properties
void get_op_opfamily_properties(Oid opno, Oid opfamily, bool ordering_op, int *strategy, Oid *lefttype, Oid *righttype)
Definition lsyscache.c:138
get_op_opfamily_sortfamily
Oid get_op_opfamily_sortfamily(Oid opno, Oid opfamily)
Definition lsyscache.c:110
get_func_support
RegProcedure get_func_support(Oid funcid)
Definition lsyscache.c:2008
get_op_opfamily_strategy
int get_op_opfamily_strategy(Oid opno, Oid opfamily)
Definition lsyscache.c:85
get_opfamily_member
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition lsyscache.c:168
get_array_type
Oid get_array_type(Oid typid)
Definition lsyscache.c:2937
op_in_opfamily
bool op_in_opfamily(Oid opno, Oid opfamily)
Definition lsyscache.c:68
get_commutator
Oid get_commutator(Oid opno)
Definition lsyscache.c:1659
make_orclause
Expr * make_orclause(List *orclauses)
Definition makefuncs.c:743
makeBoolConst
Node * makeBoolConst(bool value, bool isnull)
Definition makefuncs.c:408
make_opclause
Expr * make_opclause(Oid opno, Oid opresulttype, bool opretset, Expr *leftop, Expr *rightop, Oid opcollid, Oid inputcollid)
Definition makefuncs.c:701
pfree
void pfree(void *pointer)
Definition mcxt.c:1616
exprType
Oid exprType(const Node *expr)
Definition nodeFuncs.c:42
set_opfuncid
void set_opfuncid(OpExpr *opexpr)
Definition nodeFuncs.c:1871
expression_tree_mutator
#define expression_tree_mutator(n, m, c)
Definition nodeFuncs.h:155
is_andclause
static bool is_andclause(const void *clause)
Definition nodeFuncs.h:107
get_rightop
static Node * get_rightop(const void *clause)
Definition nodeFuncs.h:95
is_opclause
static bool is_opclause(const void *clause)
Definition nodeFuncs.h:76
expression_tree_walker
#define expression_tree_walker(n, w, c)
Definition nodeFuncs.h:153
is_notclause
static bool is_notclause(const void *clause)
Definition nodeFuncs.h:125
get_notclausearg
static Expr * get_notclausearg(const void *notclause)
Definition nodeFuncs.h:134
get_leftop
static Node * get_leftop(const void *clause)
Definition nodeFuncs.h:83
IsA
#define IsA(nodeptr, _type_)
Definition nodes.h:164
copyObject
#define copyObject(obj)
Definition nodes.h:232
Cost
double Cost
Definition nodes.h:261
nodeTag
#define nodeTag(nodeptr)
Definition nodes.h:139
Selectivity
double Selectivity
Definition nodes.h:260
makeNode
#define makeNode(_type_)
Definition nodes.h:161
castNode
#define castNode(_type_, nodeptr)
Definition nodes.h:182
JOIN_SEMI
@ JOIN_SEMI
Definition nodes.h:317
MemoryContextSwitchTo
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition palloc.h:124
truncate_useless_pathkeys
List * truncate_useless_pathkeys(PlannerInfo *root, RelOptInfo *rel, List *pathkeys)
Definition pathkeys.c:2200
has_useful_pathkeys
bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel)
Definition pathkeys.c:2291
build_index_pathkeys
List * build_index_pathkeys(PlannerInfo *root, IndexOptInfo *index, ScanDirection scandir)
Definition pathkeys.c:740
create_bitmap_and_path
BitmapAndPath * create_bitmap_and_path(PlannerInfo *root, RelOptInfo *rel, List *bitmapquals)
Definition pathnode.c:1129
create_index_path
IndexPath * create_index_path(PlannerInfo *root, IndexOptInfo *index, List *indexclauses, List *indexorderbys, List *indexorderbycols, List *pathkeys, ScanDirection indexscandir, bool indexonly, Relids required_outer, double loop_count, bool partial_path)
Definition pathnode.c:1047
add_partial_path
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition pathnode.c:793
create_bitmap_or_path
BitmapOrPath * create_bitmap_or_path(PlannerInfo *root, RelOptInfo *rel, List *bitmapquals)
Definition pathnode.c:1181
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:1096
add_path
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition pathnode.c:459
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition pathnodes.h:895
IS_DUMMY_REL
#define IS_DUMMY_REL(r)
Definition pathnodes.h:2194
PATH_REQ_OUTER
#define PATH_REQ_OUTER(path)
Definition pathnodes.h:1917
Relids
Bitmapset * Relids
Definition pathnodes.h:30
RELOPT_OTHER_MEMBER_REL
@ RELOPT_OTHER_MEMBER_REL
Definition pathnodes.h:885
pg_am.h
pg_amop.h
arg
void * arg
Definition pg_backup_utils.c:29
INDEX_MAX_KEYS
#define INDEX_MAX_KEYS
Definition pg_config_manual.h:79
lfirst
#define lfirst(lc)
Definition pg_list.h:172
lfirst_node
#define lfirst_node(type, lc)
Definition pg_list.h:176
list_length
static int list_length(const List *l)
Definition pg_list.h:152
NIL
#define NIL
Definition pg_list.h:68
list_nth_oid
static Oid list_nth_oid(const List *list, int n)
Definition pg_list.h:321
list_make1_oid
#define list_make1_oid(x1)
Definition pg_list.h:242
list_make1
#define list_make1(x1)
Definition pg_list.h:212
forthree
#define forthree(cell1, list1, cell2, list2, cell3, list3)
Definition pg_list.h:563
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
lnext
static ListCell * lnext(const List *l, const ListCell *c)
Definition pg_list.h:343
list_make1_int
#define list_make1_int(x1)
Definition pg_list.h:227
linitial_oid
#define linitial_oid(l)
Definition pg_list.h:180
lfirst_oid
#define lfirst_oid(lc)
Definition pg_list.h:174
list_make2
#define list_make2(x1, x2)
Definition pg_list.h:214
pg_operator.h
pg_opfamily.h
pg_type.h
qsort
#define qsort(a, b, c, d)
Definition port.h:495
PointerGetDatum
static Datum PointerGetDatum(const void *X)
Definition postgres.h:352
DatumGetPointer
static Pointer DatumGetPointer(Datum X)
Definition postgres.h:342
InvalidOid
#define InvalidOid
Definition postgres_ext.h:37
Oid
unsigned int Oid
Definition postgres_ext.h:32
predicate_implied_by
bool predicate_implied_by(List *predicate_list, List *clause_list, bool weak)
Definition predtest.c:152
c
char * c
Definition preproc-cursor.c:31
fb
static int fb(int x)
Definition preproc-init.c:92
get_plan_rowmark
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition preptlist.c:526
IS_TRUE
@ IS_TRUE
Definition primnodes.h:2001
IS_FALSE
@ IS_FALSE
Definition primnodes.h:2001
root
tree ctl root
Definition radixtree.h:1857
find_childrel_parents
Relids find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
Definition relnode.c:1631
restriction_is_or_clause
bool restriction_is_or_clause(RestrictInfo *restrictinfo)
Definition restrictinfo.c:407
restriction_is_securely_promotable
bool restriction_is_securely_promotable(RestrictInfo *restrictinfo, RelOptInfo *rel)
Definition restrictinfo.c:422
make_plain_restrictinfo
RestrictInfo * make_plain_restrictinfo(PlannerInfo *root, Expr *clause, Expr *orclause, bool is_pushed_down, bool has_clone, bool is_clone, bool pseudoconstant, Index security_level, Relids required_relids, Relids incompatible_relids, Relids outer_relids)
Definition restrictinfo.c:103
join_clause_is_movable_to
bool join_clause_is_movable_to(RestrictInfo *rinfo, RelOptInfo *baserel)
Definition restrictinfo.c:575
commute_restrictinfo
RestrictInfo * commute_restrictinfo(RestrictInfo *rinfo, Oid comm_op)
Definition restrictinfo.c:350
make_simple_restrictinfo
#define make_simple_restrictinfo(root, clause)
Definition restrictinfo.h:21
BackwardScanDirection
@ BackwardScanDirection
Definition sdir.h:26
ForwardScanDirection
@ ForwardScanDirection
Definition sdir.h:28
estimate_num_groups
double estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows, List **pgset, EstimationInfo *estinfo)
Definition selfuncs.c:3771
BTGreaterStrategyNumber
#define BTGreaterStrategyNumber
Definition stratnum.h:33
BTLessStrategyNumber
#define BTLessStrategyNumber
Definition stratnum.h:29
BTLessEqualStrategyNumber
#define BTLessEqualStrategyNumber
Definition stratnum.h:30
BTGreaterEqualStrategyNumber
#define BTGreaterEqualStrategyNumber
Definition stratnum.h:32
FuncExpr::funcid
Oid funcid
Definition primnodes.h:782
FuncExpr::args
List * args
Definition primnodes.h:800
IndexClauseSet::indexclauses
List * indexclauses[INDEX_MAX_KEYS]
Definition indxpath.c:56
List
Definition pg_list.h:54
List::type
NodeTag type
Definition pg_list.h:55
Node
Definition nodes.h:135
OpExpr::opno
Oid opno
Definition primnodes.h:850
OpExpr::args
List * args
Definition primnodes.h:868
PathClauseUsage::clauseids
Bitmapset * clauseids
Definition indxpath.c:65
PathClauseUsage::unclassifiable
bool unclassifiable
Definition indxpath.c:66
PathTarget::exprs
List * exprs
Definition pathnodes.h:1780
Path::pathtype
NodeTag pathtype
Definition pathnodes.h:1873
Path::total_cost
Cost total_cost
Definition pathnodes.h:1910
RelOptInfo::baserestrictinfo
List * baserestrictinfo
Definition pathnodes.h:1046
RelOptInfo::joininfo
List * joininfo
Definition pathnodes.h:1052
RelOptInfo::relids
Relids relids
Definition pathnodes.h:927
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition pathnodes.h:949
RelOptInfo::relid
Index relid
Definition pathnodes.h:973
RelOptInfo::consider_parallel
bool consider_parallel
Definition pathnodes.h:943
RelOptInfo::lateral_relids
Relids lateral_relids
Definition pathnodes.h:968
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition pathnodes.h:921
RelOptInfo::indexlist
List * indexlist
Definition pathnodes.h:995
RelOptInfo::nulling_relids
Relids nulling_relids
Definition pathnodes.h:989
RelOptInfo::rows
Cardinality rows
Definition pathnodes.h:933
RestrictInfo::is_pushed_down
bool is_pushed_down
Definition pathnodes.h:2795
RestrictInfo::security_level
Index security_level
Definition pathnodes.h:2814
RestrictInfo::required_relids
Relids required_relids
Definition pathnodes.h:2823
RestrictInfo::outer_relids
Relids outer_relids
Definition pathnodes.h:2829
RestrictInfo::incompatible_relids
Relids incompatible_relids
Definition pathnodes.h:2826
RestrictInfo::clause
Expr * clause
Definition pathnodes.h:2792
RowCompareExpr::cmptype
CompareType cmptype
Definition primnodes.h:1493
SpecialJoinInfo::syn_lefthand
Relids syn_lefthand
Definition pathnodes.h:3119
SpecialJoinInfo::semi_rhs_exprs
List * semi_rhs_exprs
Definition pathnodes.h:3132
SpecialJoinInfo::jointype
JoinType jointype
Definition pathnodes.h:3121
SpecialJoinInfo::syn_righthand
Relids syn_righthand
Definition pathnodes.h:3120
ec_member_matches_arg
Definition indxpath.c:71
ec_member_matches_arg::index
IndexOptInfo * index
Definition indxpath.c:72
ec_member_matches_arg::indexcol
int indexcol
Definition indxpath.c:73
index
Definition type.h:96
FirstLowInvalidHeapAttributeNumber
#define FirstLowInvalidHeapAttributeNumber
Definition sysattr.h:27
FirstNormalObjectId
#define FirstNormalObjectId
Definition transam.h:197
contain_var_clause
bool contain_var_clause(Node *node)
Definition var.c:406
pull_varnos
Relids pull_varnos(PlannerInfo *root, Node *node)
Definition var.c:114
pull_varattnos
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition var.c:296