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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) 1996-2025, 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 <math.h>
19
20#include "access/stratnum.h"
21#include "access/sysattr.h"
22#include "catalog/pg_am.h"
23#include "catalog/pg_amop.h"
24#include "catalog/pg_operator.h"
25#include "catalog/pg_opfamily.h"
26#include "catalog/pg_type.h"
27#include "nodes/makefuncs.h"
28#include "nodes/nodeFuncs.h"
29#include "nodes/supportnodes.h"
30#include "optimizer/cost.h"
31#include "optimizer/optimizer.h"
32#include "optimizer/pathnode.h"
33#include "optimizer/paths.h"
34#include "optimizer/prep.h"
35#include "optimizer/restrictinfo.h"
36#include "utils/lsyscache.h"
37#include "utils/selfuncs.h"
38
39
40/* XXX see PartCollMatchesExprColl */
41#define IndexCollMatchesExprColl(idxcollation, exprcollation) \
42 ((idxcollation) == InvalidOid || (idxcollation) == (exprcollation))
43
44/* Whether we are looking for plain indexscan, bitmap scan, or either */
45typedef enum
46{
47 ST_INDEXSCAN, /* must support amgettuple */
48 ST_BITMAPSCAN, /* must support amgetbitmap */
49 ST_ANYSCAN, /* either is okay */
50} ScanTypeControl;
51
52/* Data structure for collecting qual clauses that match an index */
53typedef struct
54{
55 bool nonempty; /* True if lists are not all empty */
56 /* Lists of IndexClause nodes, one list per index column */
57 List *indexclauses[INDEX_MAX_KEYS];
58} IndexClauseSet;
59
60/* Per-path data used within choose_bitmap_and() */
61typedef struct
62{
63 Path *path; /* IndexPath, BitmapAndPath, or BitmapOrPath */
64 List *quals; /* the WHERE clauses it uses */
65 List *preds; /* predicates of its partial index(es) */
66 Bitmapset *clauseids; /* quals+preds represented as a bitmapset */
67 bool unclassifiable; /* has too many quals+preds to process? */
68} PathClauseUsage;
69
70/* Callback argument for ec_member_matches_indexcol */
71typedef struct
72{
73 IndexOptInfo *index; /* index we're considering */
74 int indexcol; /* index column we want to match to */
75} ec_member_matches_arg;
76
77
78static void consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
79 IndexOptInfo *index,
80 IndexClauseSet *rclauseset,
81 IndexClauseSet *jclauseset,
82 IndexClauseSet *eclauseset,
83 List **bitindexpaths);
84static void consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
85 IndexOptInfo *index,
86 IndexClauseSet *rclauseset,
87 IndexClauseSet *jclauseset,
88 IndexClauseSet *eclauseset,
89 List **bitindexpaths,
90 List *indexjoinclauses,
91 int considered_clauses,
92 List **considered_relids);
93static void get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
94 IndexOptInfo *index,
95 IndexClauseSet *rclauseset,
96 IndexClauseSet *jclauseset,
97 IndexClauseSet *eclauseset,
98 List **bitindexpaths,
99 Relids relids,
100 List **considered_relids);
101static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
102 List *indexjoinclauses);
103static void get_index_paths(PlannerInfo *root, RelOptInfo *rel,
104 IndexOptInfo *index, IndexClauseSet *clauses,
105 List **bitindexpaths);
106static List *build_index_paths(PlannerInfo *root, RelOptInfo *rel,
107 IndexOptInfo *index, IndexClauseSet *clauses,
108 bool useful_predicate,
109 ScanTypeControl scantype,
110 bool *skip_nonnative_saop);
111static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
112 List *clauses, List *other_clauses);
113static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
114 List *clauses, List *other_clauses);
115static Path *choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel,
116 List *paths);
117static int path_usage_comparator(const void *a, const void *b);
118static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel,
119 Path *ipath);
120static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel,
121 List *paths);
122static PathClauseUsage *classify_index_clause_usage(Path *path,
123 List **clauselist);
124static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds);
125static int find_list_position(Node *node, List **nodelist);
126static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index);
127static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids);
128static double adjust_rowcount_for_semijoins(PlannerInfo *root,
129 Index cur_relid,
130 Index outer_relid,
131 double rowcount);
132static double approximate_joinrel_size(PlannerInfo *root, Relids relids);
133static void match_restriction_clauses_to_index(PlannerInfo *root,
134 IndexOptInfo *index,
135 IndexClauseSet *clauseset);
136static void match_join_clauses_to_index(PlannerInfo *root,
137 RelOptInfo *rel, IndexOptInfo *index,
138 IndexClauseSet *clauseset,
139 List **joinorclauses);
140static void match_eclass_clauses_to_index(PlannerInfo *root,
141 IndexOptInfo *index,
142 IndexClauseSet *clauseset);
143static void match_clauses_to_index(PlannerInfo *root,
144 List *clauses,
145 IndexOptInfo *index,
146 IndexClauseSet *clauseset);
147static void match_clause_to_index(PlannerInfo *root,
148 RestrictInfo *rinfo,
149 IndexOptInfo *index,
150 IndexClauseSet *clauseset);
151static IndexClause *match_clause_to_indexcol(PlannerInfo *root,
152 RestrictInfo *rinfo,
153 int indexcol,
154 IndexOptInfo *index);
155static bool IsBooleanOpfamily(Oid opfamily);
156static IndexClause *match_boolean_index_clause(PlannerInfo *root,
157 RestrictInfo *rinfo,
158 int indexcol, IndexOptInfo *index);
159static IndexClause *match_opclause_to_indexcol(PlannerInfo *root,
160 RestrictInfo *rinfo,
161 int indexcol,
162 IndexOptInfo *index);
163static IndexClause *match_funcclause_to_indexcol(PlannerInfo *root,
164 RestrictInfo *rinfo,
165 int indexcol,
166 IndexOptInfo *index);
167static IndexClause *get_index_clause_from_support(PlannerInfo *root,
168 RestrictInfo *rinfo,
169 Oid funcid,
170 int indexarg,
171 int indexcol,
172 IndexOptInfo *index);
173static IndexClause *match_saopclause_to_indexcol(PlannerInfo *root,
174 RestrictInfo *rinfo,
175 int indexcol,
176 IndexOptInfo *index);
177static IndexClause *match_rowcompare_to_indexcol(PlannerInfo *root,
178 RestrictInfo *rinfo,
179 int indexcol,
180 IndexOptInfo *index);
181static IndexClause *match_orclause_to_indexcol(PlannerInfo *root,
182 RestrictInfo *rinfo,
183 int indexcol,
184 IndexOptInfo *index);
185static IndexClause *expand_indexqual_rowcompare(PlannerInfo *root,
186 RestrictInfo *rinfo,
187 int indexcol,
188 IndexOptInfo *index,
189 Oid expr_op,
190 bool var_on_left);
191static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
192 List **orderby_clauses_p,
193 List **clause_columns_p);
194static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
195 int indexcol, Expr *clause, Oid pk_opfamily);
196static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
197 EquivalenceClass *ec, EquivalenceMember *em,
198 void *arg);
199
200
201/*
202 * create_index_paths()
203 * Generate all interesting index paths for the given relation.
204 * Candidate paths are added to the rel's pathlist (using add_path).
205 *
206 * To be considered for an index scan, an index must match one or more
207 * restriction clauses or join clauses from the query's qual condition,
208 * or match the query's ORDER BY condition, or have a predicate that
209 * matches the query's qual condition.
210 *
211 * There are two basic kinds of index scans. A "plain" index scan uses
212 * only restriction clauses (possibly none at all) in its indexqual,
213 * so it can be applied in any context. A "parameterized" index scan uses
214 * join clauses (plus restriction clauses, if available) in its indexqual.
215 * When joining such a scan to one of the relations supplying the other
216 * variables used in its indexqual, the parameterized scan must appear as
217 * the inner relation of a nestloop join; it can't be used on the outer side,
218 * nor in a merge or hash join. In that context, values for the other rels'
219 * attributes are available and fixed during any one scan of the indexpath.
220 *
221 * An IndexPath is generated and submitted to add_path() for each plain or
222 * parameterized index scan this routine deems potentially interesting for
223 * the current query.
224 *
225 * 'rel' is the relation for which we want to generate index paths
226 *
227 * Note: check_index_predicates() must have been run previously for this rel.
228 *
229 * Note: in cases involving LATERAL references in the relation's tlist, it's
230 * possible that rel->lateral_relids is nonempty. Currently, we include
231 * lateral_relids into the parameterization reported for each path, but don't
232 * take it into account otherwise. The fact that any such rels *must* be
233 * available as parameter sources perhaps should influence our choices of
234 * index quals ... but for now, it doesn't seem worth troubling over.
235 * In particular, comments below about "unparameterized" paths should be read
236 * as meaning "unparameterized so far as the indexquals are concerned".
237 */
238void
239create_index_paths(PlannerInfo *root, RelOptInfo *rel)
240{
241 List *indexpaths;
242 List *bitindexpaths;
243 List *bitjoinpaths;
244 List *joinorclauses;
245 IndexClauseSet rclauseset;
246 IndexClauseSet jclauseset;
247 IndexClauseSet eclauseset;
248 ListCell *lc;
249
250 /* Skip the whole mess if no indexes */
251 if (rel->indexlist == NIL)
252 return;
253
254 /* Bitmap paths are collected and then dealt with at the end */
255 bitindexpaths = bitjoinpaths = joinorclauses = NIL;
256
257 /* Examine each index in turn */
258 foreach(lc, rel->indexlist)
259 {
260 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
261
262 /* Protect limited-size array in IndexClauseSets */
263 Assert(index->nkeycolumns <= INDEX_MAX_KEYS);
264
265 /*
266 * Ignore partial indexes that do not match the query.
267 * (generate_bitmap_or_paths() might be able to do something with
268 * them, but that's of no concern here.)
269 */
270 if (index->indpred != NIL && !index->predOK)
271 continue;
272
273 /*
274 * Identify the restriction clauses that can match the index.
275 */
276 MemSet(&rclauseset, 0, sizeof(rclauseset));
277 match_restriction_clauses_to_index(root, index, &rclauseset);
278
279 /*
280 * Build index paths from the restriction clauses. These will be
281 * non-parameterized paths. Plain paths go directly to add_path(),
282 * bitmap paths are added to bitindexpaths to be handled below.
283 */
284 get_index_paths(root, rel, index, &rclauseset,
285 &bitindexpaths);
286
287 /*
288 * Identify the join clauses that can match the index. For the moment
289 * we keep them separate from the restriction clauses. Note that this
290 * step finds only "loose" join clauses that have not been merged into
291 * EquivalenceClasses. Also, collect join OR clauses for later.
292 */
293 MemSet(&jclauseset, 0, sizeof(jclauseset));
294 match_join_clauses_to_index(root, rel, index,
295 &jclauseset, &joinorclauses);
296
297 /*
298 * Look for EquivalenceClasses that can generate joinclauses matching
299 * the index.
300 */
301 MemSet(&eclauseset, 0, sizeof(eclauseset));
302 match_eclass_clauses_to_index(root, index,
303 &eclauseset);
304
305 /*
306 * If we found any plain or eclass join clauses, build parameterized
307 * index paths using them.
308 */
309 if (jclauseset.nonempty || eclauseset.nonempty)
310 consider_index_join_clauses(root, rel, index,
311 &rclauseset,
312 &jclauseset,
313 &eclauseset,
314 &bitjoinpaths);
315 }
316
317 /*
318 * Generate BitmapOrPaths for any suitable OR-clauses present in the
319 * restriction list. Add these to bitindexpaths.
320 */
321 indexpaths = generate_bitmap_or_paths(root, rel,
322 rel->baserestrictinfo, NIL);
323 bitindexpaths = list_concat(bitindexpaths, indexpaths);
324
325 /*
326 * Likewise, generate BitmapOrPaths for any suitable OR-clauses present in
327 * the joinclause list. Add these to bitjoinpaths.
328 */
329 indexpaths = generate_bitmap_or_paths(root, rel,
330 joinorclauses, rel->baserestrictinfo);
331 bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
332
333 /*
334 * If we found anything usable, generate a BitmapHeapPath for the most
335 * promising combination of restriction bitmap index paths. Note there
336 * will be only one such path no matter how many indexes exist. This
337 * should be sufficient since there's basically only one figure of merit
338 * (total cost) for such a path.
339 */
340 if (bitindexpaths != NIL)
341 {
342 Path *bitmapqual;
343 BitmapHeapPath *bpath;
344
345 bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
346 bpath = create_bitmap_heap_path(root, rel, bitmapqual,
347 rel->lateral_relids, 1.0, 0);
348 add_path(rel, (Path *) bpath);
349
350 /* create a partial bitmap heap path */
351 if (rel->consider_parallel && rel->lateral_relids == NULL)
352 create_partial_bitmap_paths(root, rel, bitmapqual);
353 }
354
355 /*
356 * Likewise, if we found anything usable, generate BitmapHeapPaths for the
357 * most promising combinations of join bitmap index paths. Our strategy
358 * is to generate one such path for each distinct parameterization seen
359 * among the available bitmap index paths. This may look pretty
360 * expensive, but usually there won't be very many distinct
361 * parameterizations. (This logic is quite similar to that in
362 * consider_index_join_clauses, but we're working with whole paths not
363 * individual clauses.)
364 */
365 if (bitjoinpaths != NIL)
366 {
367 List *all_path_outers;
368
369 /* Identify each distinct parameterization seen in bitjoinpaths */
370 all_path_outers = NIL;
371 foreach(lc, bitjoinpaths)
372 {
373 Path *path = (Path *) lfirst(lc);
374 Relids required_outer = PATH_REQ_OUTER(path);
375
376 all_path_outers = list_append_unique(all_path_outers,
377 required_outer);
378 }
379
380 /* Now, for each distinct parameterization set ... */
381 foreach(lc, all_path_outers)
382 {
383 Relids max_outers = (Relids) lfirst(lc);
384 List *this_path_set;
385 Path *bitmapqual;
386 Relids required_outer;
387 double loop_count;
388 BitmapHeapPath *bpath;
389 ListCell *lcp;
390
391 /* Identify all the bitmap join paths needing no more than that */
392 this_path_set = NIL;
393 foreach(lcp, bitjoinpaths)
394 {
395 Path *path = (Path *) lfirst(lcp);
396
397 if (bms_is_subset(PATH_REQ_OUTER(path), max_outers))
398 this_path_set = lappend(this_path_set, path);
399 }
400
401 /*
402 * Add in restriction bitmap paths, since they can be used
403 * together with any join paths.
404 */
405 this_path_set = list_concat(this_path_set, bitindexpaths);
406
407 /* Select best AND combination for this parameterization */
408 bitmapqual = choose_bitmap_and(root, rel, this_path_set);
409
410 /* And push that path into the mix */
411 required_outer = PATH_REQ_OUTER(bitmapqual);
412 loop_count = get_loop_count(root, rel->relid, required_outer);
413 bpath = create_bitmap_heap_path(root, rel, bitmapqual,
414 required_outer, loop_count, 0);
415 add_path(rel, (Path *) bpath);
416 }
417 }
418}
419
420/*
421 * consider_index_join_clauses
422 * Given sets of join clauses for an index, decide which parameterized
423 * index paths to build.
424 *
425 * Plain indexpaths are sent directly to add_path, while potential
426 * bitmap indexpaths are added to *bitindexpaths for later processing.
427 *
428 * 'rel' is the index's heap relation
429 * 'index' is the index for which we want to generate paths
430 * 'rclauseset' is the collection of indexable restriction clauses
431 * 'jclauseset' is the collection of indexable simple join clauses
432 * 'eclauseset' is the collection of indexable clauses from EquivalenceClasses
433 * '*bitindexpaths' is the list to add bitmap paths to
434 */
435static void
436consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
437 IndexOptInfo *index,
438 IndexClauseSet *rclauseset,
439 IndexClauseSet *jclauseset,
440 IndexClauseSet *eclauseset,
441 List **bitindexpaths)
442{
443 int considered_clauses = 0;
444 List *considered_relids = NIL;
445 int indexcol;
446
447 /*
448 * The strategy here is to identify every potentially useful set of outer
449 * rels that can provide indexable join clauses. For each such set,
450 * select all the join clauses available from those outer rels, add on all
451 * the indexable restriction clauses, and generate plain and/or bitmap
452 * index paths for that set of clauses. This is based on the assumption
453 * that it's always better to apply a clause as an indexqual than as a
454 * filter (qpqual); which is where an available clause would end up being
455 * applied if we omit it from the indexquals.
456 *
457 * This looks expensive, but in most practical cases there won't be very
458 * many distinct sets of outer rels to consider. As a safety valve when
459 * that's not true, we use a heuristic: limit the number of outer rel sets
460 * considered to a multiple of the number of clauses considered. (We'll
461 * always consider using each individual join clause, though.)
462 *
463 * For simplicity in selecting relevant clauses, we represent each set of
464 * outer rels as a maximum set of clause_relids --- that is, the indexed
465 * relation itself is also included in the relids set. considered_relids
466 * lists all relids sets we've already tried.
467 */
468 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
469 {
470 /* Consider each applicable simple join clause */
471 considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
472 consider_index_join_outer_rels(root, rel, index,
473 rclauseset, jclauseset, eclauseset,
474 bitindexpaths,
475 jclauseset->indexclauses[indexcol],
476 considered_clauses,
477 &considered_relids);
478 /* Consider each applicable eclass join clause */
479 considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
480 consider_index_join_outer_rels(root, rel, index,
481 rclauseset, jclauseset, eclauseset,
482 bitindexpaths,
483 eclauseset->indexclauses[indexcol],
484 considered_clauses,
485 &considered_relids);
486 }
487}
488
489/*
490 * consider_index_join_outer_rels
491 * Generate parameterized paths based on clause relids in the clause list.
492 *
493 * Workhorse for consider_index_join_clauses; see notes therein for rationale.
494 *
495 * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset', and
496 * 'bitindexpaths' as above
497 * 'indexjoinclauses' is a list of IndexClauses for join clauses
498 * 'considered_clauses' is the total number of clauses considered (so far)
499 * '*considered_relids' is a list of all relids sets already considered
500 */
501static void
502consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
503 IndexOptInfo *index,
504 IndexClauseSet *rclauseset,
505 IndexClauseSet *jclauseset,
506 IndexClauseSet *eclauseset,
507 List **bitindexpaths,
508 List *indexjoinclauses,
509 int considered_clauses,
510 List **considered_relids)
511{
512 ListCell *lc;
513
514 /* Examine relids of each joinclause in the given list */
515 foreach(lc, indexjoinclauses)
516 {
517 IndexClause *iclause = (IndexClause *) lfirst(lc);
518 Relids clause_relids = iclause->rinfo->clause_relids;
519 EquivalenceClass *parent_ec = iclause->rinfo->parent_ec;
520 int num_considered_relids;
521
522 /* If we already tried its relids set, no need to do so again */
523 if (list_member(*considered_relids, clause_relids))
524 continue;
525
526 /*
527 * Generate the union of this clause's relids set with each
528 * previously-tried set. This ensures we try this clause along with
529 * every interesting subset of previous clauses. However, to avoid
530 * exponential growth of planning time when there are many clauses,
531 * limit the number of relid sets accepted to 10 * considered_clauses.
532 *
533 * Note: get_join_index_paths appends entries to *considered_relids,
534 * but we do not need to visit such newly-added entries within this
535 * loop, so we don't use foreach() here. No real harm would be done
536 * if we did visit them, since the subset check would reject them; but
537 * it would waste some cycles.
538 */
539 num_considered_relids = list_length(*considered_relids);
540 for (int pos = 0; pos < num_considered_relids; pos++)
541 {
542 Relids oldrelids = (Relids) list_nth(*considered_relids, pos);
543
544 /*
545 * If either is a subset of the other, no new set is possible.
546 * This isn't a complete test for redundancy, but it's easy and
547 * cheap. get_join_index_paths will check more carefully if we
548 * already generated the same relids set.
549 */
550 if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
551 continue;
552
553 /*
554 * If this clause was derived from an equivalence class, the
555 * clause list may contain other clauses derived from the same
556 * eclass. We should not consider that combining this clause with
557 * one of those clauses generates a usefully different
558 * parameterization; so skip if any clause derived from the same
559 * eclass would already have been included when using oldrelids.
560 */
561 if (parent_ec &&
562 eclass_already_used(parent_ec, oldrelids,
563 indexjoinclauses))
564 continue;
565
566 /*
567 * If the number of relid sets considered exceeds our heuristic
568 * limit, stop considering combinations of clauses. We'll still
569 * consider the current clause alone, though (below this loop).
570 */
571 if (list_length(*considered_relids) >= 10 * considered_clauses)
572 break;
573
574 /* OK, try the union set */
575 get_join_index_paths(root, rel, index,
576 rclauseset, jclauseset, eclauseset,
577 bitindexpaths,
578 bms_union(clause_relids, oldrelids),
579 considered_relids);
580 }
581
582 /* Also try this set of relids by itself */
583 get_join_index_paths(root, rel, index,
584 rclauseset, jclauseset, eclauseset,
585 bitindexpaths,
586 clause_relids,
587 considered_relids);
588 }
589}
590
591/*
592 * get_join_index_paths
593 * Generate index paths using clauses from the specified outer relations.
594 * In addition to generating paths, relids is added to *considered_relids
595 * if not already present.
596 *
597 * Workhorse for consider_index_join_clauses; see notes therein for rationale.
598 *
599 * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset',
600 * 'bitindexpaths', 'considered_relids' as above
601 * 'relids' is the current set of relids to consider (the target rel plus
602 * one or more outer rels)
603 */
604static void
605get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
606 IndexOptInfo *index,
607 IndexClauseSet *rclauseset,
608 IndexClauseSet *jclauseset,
609 IndexClauseSet *eclauseset,
610 List **bitindexpaths,
611 Relids relids,
612 List **considered_relids)
613{
614 IndexClauseSet clauseset;
615 int indexcol;
616
617 /* If we already considered this relids set, don't repeat the work */
618 if (list_member(*considered_relids, relids))
619 return;
620
621 /* Identify indexclauses usable with this relids set */
622 MemSet(&clauseset, 0, sizeof(clauseset));
623
624 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
625 {
626 ListCell *lc;
627
628 /* First find applicable simple join clauses */
629 foreach(lc, jclauseset->indexclauses[indexcol])
630 {
631 IndexClause *iclause = (IndexClause *) lfirst(lc);
632
633 if (bms_is_subset(iclause->rinfo->clause_relids, relids))
634 clauseset.indexclauses[indexcol] =
635 lappend(clauseset.indexclauses[indexcol], iclause);
636 }
637
638 /*
639 * Add applicable eclass join clauses. The clauses generated for each
640 * column are redundant (cf generate_implied_equalities_for_column),
641 * so we need at most one. This is the only exception to the general
642 * rule of using all available index clauses.
643 */
644 foreach(lc, eclauseset->indexclauses[indexcol])
645 {
646 IndexClause *iclause = (IndexClause *) lfirst(lc);
647
648 if (bms_is_subset(iclause->rinfo->clause_relids, relids))
649 {
650 clauseset.indexclauses[indexcol] =
651 lappend(clauseset.indexclauses[indexcol], iclause);
652 break;
653 }
654 }
655
656 /* Add restriction clauses */
657 clauseset.indexclauses[indexcol] =
658 list_concat(clauseset.indexclauses[indexcol],
659 rclauseset->indexclauses[indexcol]);
660
661 if (clauseset.indexclauses[indexcol] != NIL)
662 clauseset.nonempty = true;
663 }
664
665 /* We should have found something, else caller passed silly relids */
666 Assert(clauseset.nonempty);
667
668 /* Build index path(s) using the collected set of clauses */
669 get_index_paths(root, rel, index, &clauseset, bitindexpaths);
670
671 /*
672 * Remember we considered paths for this set of relids.
673 */
674 *considered_relids = lappend(*considered_relids, relids);
675}
676
677/*
678 * eclass_already_used
679 * True if any join clause usable with oldrelids was generated from
680 * the specified equivalence class.
681 */
682static bool
683eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
684 List *indexjoinclauses)
685{
686 ListCell *lc;
687
688 foreach(lc, indexjoinclauses)
689 {
690 IndexClause *iclause = (IndexClause *) lfirst(lc);
691 RestrictInfo *rinfo = iclause->rinfo;
692
693 if (rinfo->parent_ec == parent_ec &&
694 bms_is_subset(rinfo->clause_relids, oldrelids))
695 return true;
696 }
697 return false;
698}
699
700
701/*
702 * get_index_paths
703 * Given an index and a set of index clauses for it, construct IndexPaths.
704 *
705 * Plain indexpaths are sent directly to add_path, while potential
706 * bitmap indexpaths are added to *bitindexpaths for later processing.
707 *
708 * This is a fairly simple frontend to build_index_paths(). Its reason for
709 * existence is mainly to handle ScalarArrayOpExpr quals properly. If the
710 * index AM supports them natively, we should just include them in simple
711 * index paths. If not, we should exclude them while building simple index
712 * paths, and then make a separate attempt to include them in bitmap paths.
713 */
714static void
715get_index_paths(PlannerInfo *root, RelOptInfo *rel,
716 IndexOptInfo *index, IndexClauseSet *clauses,
717 List **bitindexpaths)
718{
719 List *indexpaths;
720 bool skip_nonnative_saop = false;
721 ListCell *lc;
722
723 /*
724 * Build simple index paths using the clauses. Allow ScalarArrayOpExpr
725 * clauses only if the index AM supports them natively.
726 */
727 indexpaths = build_index_paths(root, rel,
728 index, clauses,
729 index->predOK,
730 ST_ANYSCAN,
731 &skip_nonnative_saop);
732
733 /*
734 * Submit all the ones that can form plain IndexScan plans to add_path. (A
735 * plain IndexPath can represent either a plain IndexScan or an
736 * IndexOnlyScan, but for our purposes here that distinction does not
737 * matter. However, some of the indexes might support only bitmap scans,
738 * and those we mustn't submit to add_path here.)
739 *
740 * Also, pick out the ones that are usable as bitmap scans. For that, we
741 * must discard indexes that don't support bitmap scans, and we also are
742 * only interested in paths that have some selectivity; we should discard
743 * anything that was generated solely for ordering purposes.
744 */
745 foreach(lc, indexpaths)
746 {
747 IndexPath *ipath = (IndexPath *) lfirst(lc);
748
749 if (index->amhasgettuple)
750 add_path(rel, (Path *) ipath);
751
752 if (index->amhasgetbitmap &&
753 (ipath->path.pathkeys == NIL ||
754 ipath->indexselectivity < 1.0))
755 *bitindexpaths = lappend(*bitindexpaths, ipath);
756 }
757
758 /*
759 * If there were ScalarArrayOpExpr clauses that the index can't handle
760 * natively, generate bitmap scan paths relying on executor-managed
761 * ScalarArrayOpExpr.
762 */
763 if (skip_nonnative_saop)
764 {
765 indexpaths = build_index_paths(root, rel,
766 index, clauses,
767 false,
768 ST_BITMAPSCAN,
769 NULL);
770 *bitindexpaths = list_concat(*bitindexpaths, indexpaths);
771 }
772}
773
774/*
775 * build_index_paths
776 * Given an index and a set of index clauses for it, construct zero
777 * or more IndexPaths. It also constructs zero or more partial IndexPaths.
778 *
779 * We return a list of paths because (1) this routine checks some cases
780 * that should cause us to not generate any IndexPath, and (2) in some
781 * cases we want to consider both a forward and a backward scan, so as
782 * to obtain both sort orders. Note that the paths are just returned
783 * to the caller and not immediately fed to add_path().
784 *
785 * At top level, useful_predicate should be exactly the index's predOK flag
786 * (ie, true if it has a predicate that was proven from the restriction
787 * clauses). When working on an arm of an OR clause, useful_predicate
788 * should be true if the predicate required the current OR list to be proven.
789 * Note that this routine should never be called at all if the index has an
790 * unprovable predicate.
791 *
792 * scantype indicates whether we want to create plain indexscans, bitmap
793 * indexscans, or both. When it's ST_BITMAPSCAN, we will not consider
794 * index ordering while deciding if a Path is worth generating.
795 *
796 * If skip_nonnative_saop is non-NULL, we ignore ScalarArrayOpExpr clauses
797 * unless the index AM supports them directly, and we set *skip_nonnative_saop
798 * to true if we found any such clauses (caller must initialize the variable
799 * to false). If it's NULL, we do not ignore ScalarArrayOpExpr clauses.
800 *
801 * 'rel' is the index's heap relation
802 * 'index' is the index for which we want to generate paths
803 * 'clauses' is the collection of indexable clauses (IndexClause nodes)
804 * 'useful_predicate' indicates whether the index has a useful predicate
805 * 'scantype' indicates whether we need plain or bitmap scan support
806 * 'skip_nonnative_saop' indicates whether to accept SAOP if index AM doesn't
807 */
808static List *
809build_index_paths(PlannerInfo *root, RelOptInfo *rel,
810 IndexOptInfo *index, IndexClauseSet *clauses,
811 bool useful_predicate,
812 ScanTypeControl scantype,
813 bool *skip_nonnative_saop)
814{
815 List *result = NIL;
816 IndexPath *ipath;
817 List *index_clauses;
818 Relids outer_relids;
819 double loop_count;
820 List *orderbyclauses;
821 List *orderbyclausecols;
822 List *index_pathkeys;
823 List *useful_pathkeys;
824 bool pathkeys_possibly_useful;
825 bool index_is_ordered;
826 bool index_only_scan;
827 int indexcol;
828
829 Assert(skip_nonnative_saop != NULL || scantype == ST_BITMAPSCAN);
830
831 /*
832 * Check that index supports the desired scan type(s)
833 */
834 switch (scantype)
835 {
836 case ST_INDEXSCAN:
837 if (!index->amhasgettuple)
838 return NIL;
839 break;
840 case ST_BITMAPSCAN:
841 if (!index->amhasgetbitmap)
842 return NIL;
843 break;
844 case ST_ANYSCAN:
845 /* either or both are OK */
846 break;
847 }
848
849 /*
850 * 1. Combine the per-column IndexClause lists into an overall list.
851 *
852 * In the resulting list, clauses are ordered by index key, so that the
853 * column numbers form a nondecreasing sequence. (This order is depended
854 * on by btree and possibly other places.) The list can be empty, if the
855 * index AM allows that.
856 *
857 * We also build a Relids set showing which outer rels are required by the
858 * selected clauses. Any lateral_relids are included in that, but not
859 * otherwise accounted for.
860 */
861 index_clauses = NIL;
862 outer_relids = bms_copy(rel->lateral_relids);
863 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
864 {
865 ListCell *lc;
866
867 foreach(lc, clauses->indexclauses[indexcol])
868 {
869 IndexClause *iclause = (IndexClause *) lfirst(lc);
870 RestrictInfo *rinfo = iclause->rinfo;
871
872 if (skip_nonnative_saop && !index->amsearcharray &&
873 IsA(rinfo->clause, ScalarArrayOpExpr))
874 {
875 /*
876 * Caller asked us to generate IndexPaths that omit any
877 * ScalarArrayOpExpr clauses when the underlying index AM
878 * lacks native support.
879 *
880 * We must omit this clause (and tell caller about it).
881 */
882 *skip_nonnative_saop = true;
883 continue;
884 }
885
886 /* OK to include this clause */
887 index_clauses = lappend(index_clauses, iclause);
888 outer_relids = bms_add_members(outer_relids,
889 rinfo->clause_relids);
890 }
891
892 /*
893 * If no clauses match the first index column, check for amoptionalkey
894 * restriction. We can't generate a scan over an index with
895 * amoptionalkey = false unless there's at least one index clause.
896 * (When working on columns after the first, this test cannot fail. It
897 * is always okay for columns after the first to not have any
898 * clauses.)
899 */
900 if (index_clauses == NIL && !index->amoptionalkey)
901 return NIL;
902 }
903
904 /* We do not want the index's rel itself listed in outer_relids */
905 outer_relids = bms_del_member(outer_relids, rel->relid);
906
907 /* Compute loop_count for cost estimation purposes */
908 loop_count = get_loop_count(root, rel->relid, outer_relids);
909
910 /*
911 * 2. Compute pathkeys describing index's ordering, if any, then see how
912 * many of them are actually useful for this query. This is not relevant
913 * if we are only trying to build bitmap indexscans.
914 */
915 pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN &&
916 has_useful_pathkeys(root, rel));
917 index_is_ordered = (index->sortopfamily != NULL);
918 if (index_is_ordered && pathkeys_possibly_useful)
919 {
920 index_pathkeys = build_index_pathkeys(root, index,
921 ForwardScanDirection);
922 useful_pathkeys = truncate_useless_pathkeys(root, rel,
923 index_pathkeys);
924 orderbyclauses = NIL;
925 orderbyclausecols = NIL;
926 }
927 else if (index->amcanorderbyop && pathkeys_possibly_useful)
928 {
929 /*
930 * See if we can generate ordering operators for query_pathkeys or at
931 * least some prefix thereof. Matching to just a prefix of the
932 * query_pathkeys will allow an incremental sort to be considered on
933 * the index's partially sorted results.
934 */
935 match_pathkeys_to_index(index, root->query_pathkeys,
936 &orderbyclauses,
937 &orderbyclausecols);
938 if (list_length(root->query_pathkeys) == list_length(orderbyclauses))
939 useful_pathkeys = root->query_pathkeys;
940 else
941 useful_pathkeys = list_copy_head(root->query_pathkeys,
942 list_length(orderbyclauses));
943 }
944 else
945 {
946 useful_pathkeys = NIL;
947 orderbyclauses = NIL;
948 orderbyclausecols = NIL;
949 }
950
951 /*
952 * 3. Check if an index-only scan is possible. If we're not building
953 * plain indexscans, this isn't relevant since bitmap scans don't support
954 * index data retrieval anyway.
955 */
956 index_only_scan = (scantype != ST_BITMAPSCAN &&
957 check_index_only(rel, index));
958
959 /*
960 * 4. Generate an indexscan path if there are relevant restriction clauses
961 * in the current clauses, OR the index ordering is potentially useful for
962 * later merging or final output ordering, OR the index has a useful
963 * predicate, OR an index-only scan is possible.
964 */
965 if (index_clauses != NIL || useful_pathkeys != NIL || useful_predicate ||
966 index_only_scan)
967 {
968 ipath = create_index_path(root, index,
969 index_clauses,
970 orderbyclauses,
971 orderbyclausecols,
972 useful_pathkeys,
973 ForwardScanDirection,
974 index_only_scan,
975 outer_relids,
976 loop_count,
977 false);
978 result = lappend(result, ipath);
979
980 /*
981 * If appropriate, consider parallel index scan. We don't allow
982 * parallel index scan for bitmap index scans.
983 */
984 if (index->amcanparallel &&
985 rel->consider_parallel && outer_relids == NULL &&
986 scantype != ST_BITMAPSCAN)
987 {
988 ipath = create_index_path(root, index,
989 index_clauses,
990 orderbyclauses,
991 orderbyclausecols,
992 useful_pathkeys,
993 ForwardScanDirection,
994 index_only_scan,
995 outer_relids,
996 loop_count,
997 true);
998
999 /*
1000 * if, after costing the path, we find that it's not worth using
1001 * parallel workers, just free it.
1002 */
1003 if (ipath->path.parallel_workers > 0)
1004 add_partial_path(rel, (Path *) ipath);
1005 else
1006 pfree(ipath);
1007 }
1008 }
1009
1010 /*
1011 * 5. If the index is ordered, a backwards scan might be interesting.
1012 */
1013 if (index_is_ordered && pathkeys_possibly_useful)
1014 {
1015 index_pathkeys = build_index_pathkeys(root, index,
1016 BackwardScanDirection);
1017 useful_pathkeys = truncate_useless_pathkeys(root, rel,
1018 index_pathkeys);
1019 if (useful_pathkeys != NIL)
1020 {
1021 ipath = create_index_path(root, index,
1022 index_clauses,
1023 NIL,
1024 NIL,
1025 useful_pathkeys,
1026 BackwardScanDirection,
1027 index_only_scan,
1028 outer_relids,
1029 loop_count,
1030 false);
1031 result = lappend(result, ipath);
1032
1033 /* If appropriate, consider parallel index scan */
1034 if (index->amcanparallel &&
1035 rel->consider_parallel && outer_relids == NULL &&
1036 scantype != ST_BITMAPSCAN)
1037 {
1038 ipath = create_index_path(root, index,
1039 index_clauses,
1040 NIL,
1041 NIL,
1042 useful_pathkeys,
1043 BackwardScanDirection,
1044 index_only_scan,
1045 outer_relids,
1046 loop_count,
1047 true);
1048
1049 /*
1050 * if, after costing the path, we find that it's not worth
1051 * using parallel workers, just free it.
1052 */
1053 if (ipath->path.parallel_workers > 0)
1054 add_partial_path(rel, (Path *) ipath);
1055 else
1056 pfree(ipath);
1057 }
1058 }
1059 }
1060
1061 return result;
1062}
1063
1064/*
1065 * build_paths_for_OR
1066 * Given a list of restriction clauses from one arm of an OR clause,
1067 * construct all matching IndexPaths for the relation.
1068 *
1069 * Here we must scan all indexes of the relation, since a bitmap OR tree
1070 * can use multiple indexes.
1071 *
1072 * The caller actually supplies two lists of restriction clauses: some
1073 * "current" ones and some "other" ones. Both lists can be used freely
1074 * to match keys of the index, but an index must use at least one of the
1075 * "current" clauses to be considered usable. The motivation for this is
1076 * examples like
1077 * WHERE (x = 42) AND (... OR (y = 52 AND z = 77) OR ....)
1078 * While we are considering the y/z subclause of the OR, we can use "x = 42"
1079 * as one of the available index conditions; but we shouldn't match the
1080 * subclause to any index on x alone, because such a Path would already have
1081 * been generated at the upper level. So we could use an index on x,y,z
1082 * or an index on x,y for the OR subclause, but not an index on just x.
1083 * When dealing with a partial index, a match of the index predicate to
1084 * one of the "current" clauses also makes the index usable.
1085 *
1086 * 'rel' is the relation for which we want to generate index paths
1087 * 'clauses' is the current list of clauses (RestrictInfo nodes)
1088 * 'other_clauses' is the list of additional upper-level clauses
1089 */
1090static List *
1091build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
1092 List *clauses, List *other_clauses)
1093{
1094 List *result = NIL;
1095 List *all_clauses = NIL; /* not computed till needed */
1096 ListCell *lc;
1097
1098 foreach(lc, rel->indexlist)
1099 {
1100 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
1101 IndexClauseSet clauseset;
1102 List *indexpaths;
1103 bool useful_predicate;
1104
1105 /* Ignore index if it doesn't support bitmap scans */
1106 if (!index->amhasgetbitmap)
1107 continue;
1108
1109 /*
1110 * Ignore partial indexes that do not match the query. If a partial
1111 * index is marked predOK then we know it's OK. Otherwise, we have to
1112 * test whether the added clauses are sufficient to imply the
1113 * predicate. If so, we can use the index in the current context.
1114 *
1115 * We set useful_predicate to true iff the predicate was proven using
1116 * the current set of clauses. This is needed to prevent matching a
1117 * predOK index to an arm of an OR, which would be a legal but
1118 * pointlessly inefficient plan. (A better plan will be generated by
1119 * just scanning the predOK index alone, no OR.)
1120 */
1121 useful_predicate = false;
1122 if (index->indpred != NIL)
1123 {
1124 if (index->predOK)
1125 {
1126 /* Usable, but don't set useful_predicate */
1127 }
1128 else
1129 {
1130 /* Form all_clauses if not done already */
1131 if (all_clauses == NIL)
1132 all_clauses = list_concat_copy(clauses, other_clauses);
1133
1134 if (!predicate_implied_by(index->indpred, all_clauses, false))
1135 continue; /* can't use it at all */
1136
1137 if (!predicate_implied_by(index->indpred, other_clauses, false))
1138 useful_predicate = true;
1139 }
1140 }
1141
1142 /*
1143 * Identify the restriction clauses that can match the index.
1144 */
1145 MemSet(&clauseset, 0, sizeof(clauseset));
1146 match_clauses_to_index(root, clauses, index, &clauseset);
1147
1148 /*
1149 * If no matches so far, and the index predicate isn't useful, we
1150 * don't want it.
1151 */
1152 if (!clauseset.nonempty && !useful_predicate)
1153 continue;
1154
1155 /*
1156 * Add "other" restriction clauses to the clauseset.
1157 */
1158 match_clauses_to_index(root, other_clauses, index, &clauseset);
1159
1160 /*
1161 * Construct paths if possible.
1162 */
1163 indexpaths = build_index_paths(root, rel,
1164 index, &clauseset,
1165 useful_predicate,
1166 ST_BITMAPSCAN,
1167 NULL);
1168 result = list_concat(result, indexpaths);
1169 }
1170
1171 return result;
1172}
1173
1174/*
1175 * Utility structure used to group similar OR-clause arguments in
1176 * group_similar_or_args(). It represents information about the OR-clause
1177 * argument and its matching index key.
1178 */
1179typedef struct
1180{
1181 int indexnum; /* index of the matching index, or -1 if no
1182 * matching index */
1183 int colnum; /* index of the matching column, or -1 if no
1184 * matching index */
1185 Oid opno; /* OID of the OpClause operator, or InvalidOid
1186 * if not an OpExpr */
1187 Oid inputcollid; /* OID of the OpClause input collation */
1188 int argindex; /* index of the clause in the list of
1189 * arguments */
1190 int groupindex; /* value of argindex for the fist clause in
1191 * the group of similar clauses */
1192} OrArgIndexMatch;
1193
1194/*
1195 * Comparison function for OrArgIndexMatch which provides sort order placing
1196 * similar OR-clause arguments together.
1197 */
1198static int
1199or_arg_index_match_cmp(const void *a, const void *b)
1200{
1201 const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1202 const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1203
1204 if (match_a->indexnum < match_b->indexnum)
1205 return -1;
1206 else if (match_a->indexnum > match_b->indexnum)
1207 return 1;
1208
1209 if (match_a->colnum < match_b->colnum)
1210 return -1;
1211 else if (match_a->colnum > match_b->colnum)
1212 return 1;
1213
1214 if (match_a->opno < match_b->opno)
1215 return -1;
1216 else if (match_a->opno > match_b->opno)
1217 return 1;
1218
1219 if (match_a->inputcollid < match_b->inputcollid)
1220 return -1;
1221 else if (match_a->inputcollid > match_b->inputcollid)
1222 return 1;
1223
1224 if (match_a->argindex < match_b->argindex)
1225 return -1;
1226 else if (match_a->argindex > match_b->argindex)
1227 return 1;
1228
1229 return 0;
1230}
1231
1232/*
1233 * Another comparison function for OrArgIndexMatch. It sorts groups together
1234 * using groupindex. The group items are then sorted by argindex.
1235 */
1236static int
1237or_arg_index_match_cmp_group(const void *a, const void *b)
1238{
1239 const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1240 const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1241
1242 if (match_a->groupindex < match_b->groupindex)
1243 return -1;
1244 else if (match_a->groupindex > match_b->groupindex)
1245 return 1;
1246
1247 if (match_a->argindex < match_b->argindex)
1248 return -1;
1249 else if (match_a->argindex > match_b->argindex)
1250 return 1;
1251
1252 return 0;
1253}
1254
1255/*
1256 * group_similar_or_args
1257 * Transform incoming OR-restrictinfo into a list of sub-restrictinfos,
1258 * each of them containing a subset of similar OR-clause arguments from
1259 * the source rinfo.
1260 *
1261 * Similar OR-clause arguments are of the form "indexkey op constant" having
1262 * the same indexkey, operator, and collation. Constant may comprise either
1263 * Const or Param. It may be employed later, during the
1264 * match_clause_to_indexcol() to transform the whole OR-sub-rinfo to an SAOP
1265 * clause.
1266 *
1267 * Returns the processed list of OR-clause arguments.
1268 */
1269static List *
1270group_similar_or_args(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *rinfo)
1271{
1272 int n;
1273 int i;
1274 int group_start;
1275 OrArgIndexMatch *matches;
1276 bool matched = false;
1277 ListCell *lc;
1278 ListCell *lc2;
1279 List *orargs;
1280 List *result = NIL;
1281 Index relid = rel->relid;
1282
1283 Assert(IsA(rinfo->orclause, BoolExpr));
1284 orargs = ((BoolExpr *) rinfo->orclause)->args;
1285 n = list_length(orargs);
1286
1287 /*
1288 * To avoid N^2 behavior, take utility pass along the list of OR-clause
1289 * arguments. For each argument, fill the OrArgIndexMatch structure,
1290 * which will be used to sort these arguments at the next step.
1291 */
1292 i = -1;
1293 matches = (OrArgIndexMatch *) palloc(sizeof(OrArgIndexMatch) * n);
1294 foreach(lc, orargs)
1295 {
1296 Node *arg = lfirst(lc);
1297 RestrictInfo *argrinfo;
1298 OpExpr *clause;
1299 Oid opno;
1300 Node *leftop,
1301 *rightop;
1302 Node *nonConstExpr;
1303 int indexnum;
1304 int colnum;
1305
1306 i++;
1307 matches[i].argindex = i;
1308 matches[i].groupindex = i;
1309 matches[i].indexnum = -1;
1310 matches[i].colnum = -1;
1311 matches[i].opno = InvalidOid;
1312 matches[i].inputcollid = InvalidOid;
1313
1314 if (!IsA(arg, RestrictInfo))
1315 continue;
1316
1317 argrinfo = castNode(RestrictInfo, arg);
1318
1319 /* Only operator clauses can match */
1320 if (!IsA(argrinfo->clause, OpExpr))
1321 continue;
1322
1323 clause = (OpExpr *) argrinfo->clause;
1324 opno = clause->opno;
1325
1326 /* Only binary operators can match */
1327 if (list_length(clause->args) != 2)
1328 continue;
1329
1330 /*
1331 * Ignore any RelabelType node above the operands. This is needed to
1332 * be able to apply indexscanning in binary-compatible-operator cases.
1333 * Note: we can assume there is at most one RelabelType node;
1334 * eval_const_expressions() will have simplified if more than one.
1335 */
1336 leftop = get_leftop(clause);
1337 if (IsA(leftop, RelabelType))
1338 leftop = (Node *) ((RelabelType *) leftop)->arg;
1339
1340 rightop = get_rightop(clause);
1341 if (IsA(rightop, RelabelType))
1342 rightop = (Node *) ((RelabelType *) rightop)->arg;
1343
1344 /*
1345 * Check for clauses of the form: (indexkey operator constant) or
1346 * (constant operator indexkey). But we don't know a particular index
1347 * yet. Therefore, we try to distinguish the potential index key and
1348 * constant first, then search for a matching index key among all
1349 * indexes.
1350 */
1351 if (bms_is_member(relid, argrinfo->right_relids) &&
1352 !bms_is_member(relid, argrinfo->left_relids) &&
1353 !contain_volatile_functions(leftop))
1354 {
1355 opno = get_commutator(opno);
1356
1357 if (!OidIsValid(opno))
1358 {
1359 /* commutator doesn't exist, we can't reverse the order */
1360 continue;
1361 }
1362 nonConstExpr = rightop;
1363 }
1364 else if (bms_is_member(relid, argrinfo->left_relids) &&
1365 !bms_is_member(relid, argrinfo->right_relids) &&
1366 !contain_volatile_functions(rightop))
1367 {
1368 nonConstExpr = leftop;
1369 }
1370 else
1371 {
1372 continue;
1373 }
1374
1375 /*
1376 * Match non-constant part to the index key. It's possible that a
1377 * single non-constant part matches multiple index keys. It's OK, we
1378 * just stop with first matching index key. Given that this choice is
1379 * determined the same for every clause, we will group similar clauses
1380 * together anyway.
1381 */
1382 indexnum = 0;
1383 foreach(lc2, rel->indexlist)
1384 {
1385 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc2);
1386
1387 /*
1388 * Ignore index if it doesn't support bitmap scans or SAOP
1389 * clauses.
1390 */
1391 if (!index->amhasgetbitmap || !index->amsearcharray)
1392 continue;
1393
1394 for (colnum = 0; colnum < index->nkeycolumns; colnum++)
1395 {
1396 if (match_index_to_operand(nonConstExpr, colnum, index))
1397 {
1398 matches[i].indexnum = indexnum;
1399 matches[i].colnum = colnum;
1400 matches[i].opno = opno;
1401 matches[i].inputcollid = clause->inputcollid;
1402 matched = true;
1403 break;
1404 }
1405 }
1406
1407 /*
1408 * Stop looping through the indexes, if we managed to match
1409 * nonConstExpr to any index column.
1410 */
1411 if (matches[i].indexnum >= 0)
1412 break;
1413 indexnum++;
1414 }
1415 }
1416
1417 /*
1418 * Fast-path check: if no clause is matching to the index column, we can
1419 * just give up at this stage and return the clause list as-is.
1420 */
1421 if (!matched)
1422 {
1423 pfree(matches);
1424 return orargs;
1425 }
1426
1427 /*
1428 * Sort clauses to make similar clauses go together. But at the same
1429 * time, we would like to change the order of clauses as little as
1430 * possible. To do so, we reorder each group of similar clauses so that
1431 * the first item of the group stays in place, and all the other items are
1432 * moved after it. So, if there are no similar clauses, the order of
1433 * clauses stays the same. When there are some groups, required
1434 * reordering happens while the rest of the clauses remain in their
1435 * places. That is achieved by assigning a 'groupindex' to each clause:
1436 * the number of the first item in the group in the original clause list.
1437 */
1438 qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp);
1439
1440 /* Assign groupindex to the sorted clauses */
1441 for (i = 1; i < n; i++)
1442 {
1443 /*
1444 * When two clauses are similar and should belong to the same group,
1445 * copy the 'groupindex' from the previous clause. Given we are
1446 * considering clauses in direct order, all the clauses would have a
1447 * 'groupindex' equal to the 'groupindex' of the first clause in the
1448 * group.
1449 */
1450 if (matches[i].indexnum == matches[i - 1].indexnum &&
1451 matches[i].colnum == matches[i - 1].colnum &&
1452 matches[i].opno == matches[i - 1].opno &&
1453 matches[i].inputcollid == matches[i - 1].inputcollid &&
1454 matches[i].indexnum != -1)
1455 matches[i].groupindex = matches[i - 1].groupindex;
1456 }
1457
1458 /* Re-sort clauses first by groupindex then by argindex */
1459 qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp_group);
1460
1461 /*
1462 * Group similar clauses into single sub-restrictinfo. Side effect: the
1463 * resulting list of restrictions will be sorted by indexnum and colnum.
1464 */
1465 group_start = 0;
1466 for (i = 1; i <= n; i++)
1467 {
1468 /* Check if it's a group boundary */
1469 if (group_start >= 0 &&
1470 (i == n ||
1471 matches[i].indexnum != matches[group_start].indexnum ||
1472 matches[i].colnum != matches[group_start].colnum ||
1473 matches[i].opno != matches[group_start].opno ||
1474 matches[i].inputcollid != matches[group_start].inputcollid ||
1475 matches[i].indexnum == -1))
1476 {
1477 /*
1478 * One clause in group: add it "as is" to the upper-level OR.
1479 */
1480 if (i - group_start == 1)
1481 {
1482 result = lappend(result,
1483 list_nth(orargs,
1484 matches[group_start].argindex));
1485 }
1486 else
1487 {
1488 /*
1489 * Two or more clauses in a group: create a nested OR.
1490 */
1491 List *args = NIL;
1492 List *rargs = NIL;
1493 RestrictInfo *subrinfo;
1494 int j;
1495
1496 Assert(i - group_start >= 2);
1497
1498 /* Construct the list of nested OR arguments */
1499 for (j = group_start; j < i; j++)
1500 {
1501 Node *arg = list_nth(orargs, matches[j].argindex);
1502
1503 rargs = lappend(rargs, arg);
1504 if (IsA(arg, RestrictInfo))
1505 args = lappend(args, ((RestrictInfo *) arg)->clause);
1506 else
1507 args = lappend(args, arg);
1508 }
1509
1510 /* Construct the nested OR and wrap it with RestrictInfo */
1511 subrinfo = make_plain_restrictinfo(root,
1512 make_orclause(args),
1513 make_orclause(rargs),
1514 rinfo->is_pushed_down,
1515 rinfo->has_clone,
1516 rinfo->is_clone,
1517 rinfo->pseudoconstant,
1518 rinfo->security_level,
1519 rinfo->required_relids,
1520 rinfo->incompatible_relids,
1521 rinfo->outer_relids);
1522 result = lappend(result, subrinfo);
1523 }
1524
1525 group_start = i;
1526 }
1527 }
1528 pfree(matches);
1529 return result;
1530}
1531
1532/*
1533 * make_bitmap_paths_for_or_group
1534 * Generate bitmap paths for a group of similar OR-clause arguments
1535 * produced by group_similar_or_args().
1536 *
1537 * This function considers two cases: (1) matching a group of clauses to
1538 * the index as a whole, and (2) matching the individual clauses one-by-one.
1539 * (1) typically comprises an optimal solution. If not, (2) typically
1540 * comprises fair alternative.
1541 *
1542 * Ideally, we could consider all arbitrary splits of arguments into
1543 * subgroups, but that could lead to unacceptable computational complexity.
1544 * This is why we only consider two cases of above.
1545 */
1546static List *
1547make_bitmap_paths_for_or_group(PlannerInfo *root, RelOptInfo *rel,
1548 RestrictInfo *ri, List *other_clauses)
1549{
1550 List *jointlist = NIL;
1551 List *splitlist = NIL;
1552 ListCell *lc;
1553 List *orargs;
1554 List *args = ((BoolExpr *) ri->orclause)->args;
1555 Cost jointcost = 0.0,
1556 splitcost = 0.0;
1557 Path *bitmapqual;
1558 List *indlist;
1559
1560 /*
1561 * First, try to match the whole group to the one index.
1562 */
1563 orargs = list_make1(ri);
1564 indlist = build_paths_for_OR(root, rel,
1565 orargs,
1566 other_clauses);
1567 if (indlist != NIL)
1568 {
1569 bitmapqual = choose_bitmap_and(root, rel, indlist);
1570 jointcost = bitmapqual->total_cost;
1571 jointlist = list_make1(bitmapqual);
1572 }
1573
1574 /*
1575 * If we manage to find a bitmap scan, which uses the group of OR-clause
1576 * arguments as a whole, we can skip matching OR-clause arguments
1577 * one-by-one as long as there are no other clauses, which can bring more
1578 * efficiency to one-by-one case.
1579 */
1580 if (jointlist != NIL && other_clauses == NIL)
1581 return jointlist;
1582
1583 /*
1584 * Also try to match all containing clauses one-by-one.
1585 */
1586 foreach(lc, args)
1587 {
1588 orargs = list_make1(lfirst(lc));
1589
1590 indlist = build_paths_for_OR(root, rel,
1591 orargs,
1592 other_clauses);
1593
1594 if (indlist == NIL)
1595 {
1596 splitlist = NIL;
1597 break;
1598 }
1599
1600 bitmapqual = choose_bitmap_and(root, rel, indlist);
1601 splitcost += bitmapqual->total_cost;
1602 splitlist = lappend(splitlist, bitmapqual);
1603 }
1604
1605 /*
1606 * Pick the best option.
1607 */
1608 if (splitlist == NIL)
1609 return jointlist;
1610 else if (jointlist == NIL)
1611 return splitlist;
1612 else
1613 return (jointcost < splitcost) ? jointlist : splitlist;
1614}
1615
1616
1617/*
1618 * generate_bitmap_or_paths
1619 * Look through the list of clauses to find OR clauses, and generate
1620 * a BitmapOrPath for each one we can handle that way. Return a list
1621 * of the generated BitmapOrPaths.
1622 *
1623 * other_clauses is a list of additional clauses that can be assumed true
1624 * for the purpose of generating indexquals, but are not to be searched for
1625 * ORs. (See build_paths_for_OR() for motivation.)
1626 */
1627static List *
1628generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
1629 List *clauses, List *other_clauses)
1630{
1631 List *result = NIL;
1632 List *all_clauses;
1633 ListCell *lc;
1634
1635 /*
1636 * We can use both the current and other clauses as context for
1637 * build_paths_for_OR; no need to remove ORs from the lists.
1638 */
1639 all_clauses = list_concat_copy(clauses, other_clauses);
1640
1641 foreach(lc, clauses)
1642 {
1643 RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1644 List *pathlist;
1645 Path *bitmapqual;
1646 ListCell *j;
1647 List *groupedArgs;
1648 List *inner_other_clauses = NIL;
1649
1650 /* Ignore RestrictInfos that aren't ORs */
1651 if (!restriction_is_or_clause(rinfo))
1652 continue;
1653
1654 /*
1655 * We must be able to match at least one index to each of the arms of
1656 * the OR, else we can't use it.
1657 */
1658 pathlist = NIL;
1659
1660 /*
1661 * Group the similar OR-clause arguments into dedicated RestrictInfos,
1662 * because each of those RestrictInfos has a chance to match the index
1663 * as a whole.
1664 */
1665 groupedArgs = group_similar_or_args(root, rel, rinfo);
1666
1667 if (groupedArgs != ((BoolExpr *) rinfo->orclause)->args)
1668 {
1669 /*
1670 * Some parts of the rinfo were probably grouped. In this case,
1671 * we have a set of sub-rinfos that together are an exact
1672 * duplicate of rinfo. Thus, we need to remove the rinfo from
1673 * other clauses. match_clauses_to_index detects duplicated
1674 * iclauses by comparing pointers to original rinfos that would be
1675 * different. So, we must delete rinfo to avoid de-facto
1676 * duplicated clauses in the index clauses list.
1677 */
1678 inner_other_clauses = list_delete(list_copy(all_clauses), rinfo);
1679 }
1680
1681 foreach(j, groupedArgs)
1682 {
1683 Node *orarg = (Node *) lfirst(j);
1684 List *indlist;
1685
1686 /* OR arguments should be ANDs or sub-RestrictInfos */
1687 if (is_andclause(orarg))
1688 {
1689 List *andargs = ((BoolExpr *) orarg)->args;
1690
1691 indlist = build_paths_for_OR(root, rel,
1692 andargs,
1693 all_clauses);
1694
1695 /* Recurse in case there are sub-ORs */
1696 indlist = list_concat(indlist,
1697 generate_bitmap_or_paths(root, rel,
1698 andargs,
1699 all_clauses));
1700 }
1701 else if (restriction_is_or_clause(castNode(RestrictInfo, orarg)))
1702 {
1703 RestrictInfo *ri = castNode(RestrictInfo, orarg);
1704
1705 /*
1706 * Generate bitmap paths for the group of similar OR-clause
1707 * arguments.
1708 */
1709 indlist = make_bitmap_paths_for_or_group(root,
1710 rel, ri,
1711 inner_other_clauses);
1712
1713 if (indlist == NIL)
1714 {
1715 pathlist = NIL;
1716 break;
1717 }
1718 else
1719 {
1720 pathlist = list_concat(pathlist, indlist);
1721 continue;
1722 }
1723 }
1724 else
1725 {
1726 RestrictInfo *ri = castNode(RestrictInfo, orarg);
1727 List *orargs;
1728
1729 orargs = list_make1(ri);
1730
1731 indlist = build_paths_for_OR(root, rel,
1732 orargs,
1733 all_clauses);
1734 }
1735
1736 /*
1737 * If nothing matched this arm, we can't do anything with this OR
1738 * clause.
1739 */
1740 if (indlist == NIL)
1741 {
1742 pathlist = NIL;
1743 break;
1744 }
1745
1746 /*
1747 * OK, pick the most promising AND combination, and add it to
1748 * pathlist.
1749 */
1750 bitmapqual = choose_bitmap_and(root, rel, indlist);
1751 pathlist = lappend(pathlist, bitmapqual);
1752 }
1753
1754 if (inner_other_clauses != NIL)
1755 list_free(inner_other_clauses);
1756
1757 /*
1758 * If we have a match for every arm, then turn them into a
1759 * BitmapOrPath, and add to result list.
1760 */
1761 if (pathlist != NIL)
1762 {
1763 bitmapqual = (Path *) create_bitmap_or_path(root, rel, pathlist);
1764 result = lappend(result, bitmapqual);
1765 }
1766 }
1767
1768 return result;
1769}
1770
1771
1772/*
1773 * choose_bitmap_and
1774 * Given a nonempty list of bitmap paths, AND them into one path.
1775 *
1776 * This is a nontrivial decision since we can legally use any subset of the
1777 * given path set. We want to choose a good tradeoff between selectivity
1778 * and cost of computing the bitmap.
1779 *
1780 * The result is either a single one of the inputs, or a BitmapAndPath
1781 * combining multiple inputs.
1782 */
1783static Path *
1784choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
1785{
1786 int npaths = list_length(paths);
1787 PathClauseUsage **pathinfoarray;
1788 PathClauseUsage *pathinfo;
1789 List *clauselist;
1790 List *bestpaths = NIL;
1791 Cost bestcost = 0;
1792 int i,
1793 j;
1794 ListCell *l;
1795
1796 Assert(npaths > 0); /* else caller error */
1797 if (npaths == 1)
1798 return (Path *) linitial(paths); /* easy case */
1799
1800 /*
1801 * In theory we should consider every nonempty subset of the given paths.
1802 * In practice that seems like overkill, given the crude nature of the
1803 * estimates, not to mention the possible effects of higher-level AND and
1804 * OR clauses. Moreover, it's completely impractical if there are a large
1805 * number of paths, since the work would grow as O(2^N).
1806 *
1807 * As a heuristic, we first check for paths using exactly the same sets of
1808 * WHERE clauses + index predicate conditions, and reject all but the
1809 * cheapest-to-scan in any such group. This primarily gets rid of indexes
1810 * that include the interesting columns but also irrelevant columns. (In
1811 * situations where the DBA has gone overboard on creating variant
1812 * indexes, this can make for a very large reduction in the number of
1813 * paths considered further.)
1814 *
1815 * We then sort the surviving paths with the cheapest-to-scan first, and
1816 * for each path, consider using that path alone as the basis for a bitmap
1817 * scan. Then we consider bitmap AND scans formed from that path plus
1818 * each subsequent (higher-cost) path, adding on a subsequent path if it
1819 * results in a reduction in the estimated total scan cost. This means we
1820 * consider about O(N^2) rather than O(2^N) path combinations, which is
1821 * quite tolerable, especially given than N is usually reasonably small
1822 * because of the prefiltering step. The cheapest of these is returned.
1823 *
1824 * We will only consider AND combinations in which no two indexes use the
1825 * same WHERE clause. This is a bit of a kluge: it's needed because
1826 * costsize.c and clausesel.c aren't very smart about redundant clauses.
1827 * They will usually double-count the redundant clauses, producing a
1828 * too-small selectivity that makes a redundant AND step look like it
1829 * reduces the total cost. Perhaps someday that code will be smarter and
1830 * we can remove this limitation. (But note that this also defends
1831 * against flat-out duplicate input paths, which can happen because
1832 * match_join_clauses_to_index will find the same OR join clauses that
1833 * extract_restriction_or_clauses has pulled OR restriction clauses out
1834 * of.)
1835 *
1836 * For the same reason, we reject AND combinations in which an index
1837 * predicate clause duplicates another clause. Here we find it necessary
1838 * to be even stricter: we'll reject a partial index if any of its
1839 * predicate clauses are implied by the set of WHERE clauses and predicate
1840 * clauses used so far. This covers cases such as a condition "x = 42"
1841 * used with a plain index, followed by a clauseless scan of a partial
1842 * index "WHERE x >= 40 AND x < 50". The partial index has been accepted
1843 * only because "x = 42" was present, and so allowing it would partially
1844 * double-count selectivity. (We could use predicate_implied_by on
1845 * regular qual clauses too, to have a more intelligent, but much more
1846 * expensive, check for redundancy --- but in most cases simple equality
1847 * seems to suffice.)
1848 */
1849
1850 /*
1851 * Extract clause usage info and detect any paths that use exactly the
1852 * same set of clauses; keep only the cheapest-to-scan of any such groups.
1853 * The surviving paths are put into an array for qsort'ing.
1854 */
1855 pathinfoarray = (PathClauseUsage **)
1856 palloc(npaths * sizeof(PathClauseUsage *));
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 = (PathClauseUsage *) palloc(sizeof(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 or NULL,
3293 * if failed.
3294 */
3295static IndexClause *
3296match_orclause_to_indexcol(PlannerInfo *root,
3297 RestrictInfo *rinfo,
3298 int indexcol,
3299 IndexOptInfo *index)
3300{
3301 ListCell *lc;
3302 BoolExpr *orclause = (BoolExpr *) rinfo->orclause;
3303 Node *indexExpr = NULL;
3304 List *consts = NIL;
3305 ScalarArrayOpExpr *saopexpr = NULL;
3306 Oid matchOpno = InvalidOid;
3307 IndexClause *iclause;
3308 Oid consttype = InvalidOid;
3309 Oid arraytype = InvalidOid;
3310 Oid inputcollid = InvalidOid;
3311 bool firstTime = true;
3312 bool haveNonConst = false;
3313 Index indexRelid = index->rel->relid;
3314
3315 Assert(IsA(orclause, BoolExpr));
3316 Assert(orclause->boolop == OR_EXPR);
3317
3318 /* Ignore index if it doesn't support SAOP clauses */
3319 if (!index->amsearcharray)
3320 return NULL;
3321
3322 /*
3323 * Try to convert a list of OR-clauses to a single SAOP expression. Each
3324 * OR entry must be in the form: (indexkey operator constant) or (constant
3325 * operator indexkey). Operators of all the entries must match. To be
3326 * effective, give up on the first non-matching entry. Exit is
3327 * implemented as a break from the loop, which is catched afterwards.
3328 */
3329 foreach(lc, orclause->args)
3330 {
3331 RestrictInfo *subRinfo;
3332 OpExpr *subClause;
3333 Oid opno;
3334 Node *leftop,
3335 *rightop;
3336 Node *constExpr;
3337
3338 if (!IsA(lfirst(lc), RestrictInfo))
3339 break;
3340
3341 subRinfo = (RestrictInfo *) lfirst(lc);
3342
3343 /* Only operator clauses can match */
3344 if (!IsA(subRinfo->clause, OpExpr))
3345 break;
3346
3347 subClause = (OpExpr *) subRinfo->clause;
3348 opno = subClause->opno;
3349
3350 /* Only binary operators can match */
3351 if (list_length(subClause->args) != 2)
3352 break;
3353
3354 /*
3355 * The parameters below must match between sub-rinfo and its parent as
3356 * make_restrictinfo() fills them with the same values, and further
3357 * modifications are also the same for the whole subtree. However,
3358 * still make a sanity check.
3359 */
3360 Assert(subRinfo->is_pushed_down == rinfo->is_pushed_down);
3361 Assert(subRinfo->is_clone == rinfo->is_clone);
3362 Assert(subRinfo->security_level == rinfo->security_level);
3363 Assert(bms_equal(subRinfo->incompatible_relids, rinfo->incompatible_relids));
3364 Assert(bms_equal(subRinfo->outer_relids, rinfo->outer_relids));
3365
3366 /*
3367 * Also, check that required_relids in sub-rinfo is subset of parent's
3368 * required_relids.
3369 */
3370 Assert(bms_is_subset(subRinfo->required_relids, rinfo->required_relids));
3371
3372 /* Only the operator returning a boolean suit the transformation. */
3373 if (get_op_rettype(opno) != BOOLOID)
3374 break;
3375
3376 /*
3377 * Check for clauses of the form: (indexkey operator constant) or
3378 * (constant operator indexkey). See match_clause_to_indexcol's notes
3379 * about const-ness.
3380 */
3381 leftop = (Node *) linitial(subClause->args);
3382 rightop = (Node *) lsecond(subClause->args);
3383 if (match_index_to_operand(leftop, indexcol, index) &&
3384 !bms_is_member(indexRelid, subRinfo->right_relids) &&
3385 !contain_volatile_functions(rightop))
3386 {
3387 indexExpr = leftop;
3388 constExpr = rightop;
3389 }
3390 else if (match_index_to_operand(rightop, indexcol, index) &&
3391 !bms_is_member(indexRelid, subRinfo->left_relids) &&
3392 !contain_volatile_functions(leftop))
3393 {
3394 opno = get_commutator(opno);
3395 if (!OidIsValid(opno))
3396 {
3397 /* commutator doesn't exist, we can't reverse the order */
3398 break;
3399 }
3400 indexExpr = rightop;
3401 constExpr = leftop;
3402 }
3403 else
3404 {
3405 break;
3406 }
3407
3408 /*
3409 * Ignore any RelabelType node above the operands. This is needed to
3410 * be able to apply indexscanning in binary-compatible-operator cases.
3411 * Note: we can assume there is at most one RelabelType node;
3412 * eval_const_expressions() will have simplified if more than one.
3413 */
3414 if (IsA(constExpr, RelabelType))
3415 constExpr = (Node *) ((RelabelType *) constExpr)->arg;
3416 if (IsA(indexExpr, RelabelType))
3417 indexExpr = (Node *) ((RelabelType *) indexExpr)->arg;
3418
3419 /* Forbid transformation for composite types, records. */
3420 if (type_is_rowtype(exprType(constExpr)) ||
3421 type_is_rowtype(exprType(indexExpr)))
3422 break;
3423
3424 /*
3425 * Save information about the operator, type, and collation for the
3426 * first matching qual. Then, check that subsequent quals match the
3427 * first.
3428 */
3429 if (firstTime)
3430 {
3431 matchOpno = opno;
3432 consttype = exprType(constExpr);
3433 arraytype = get_array_type(consttype);
3434 inputcollid = subClause->inputcollid;
3435
3436 /*
3437 * Check that the operator is presented in the opfamily and that
3438 * the expression collation matches the index collation. Also,
3439 * there must be an array type to construct an array later.
3440 */
3441 if (!IndexCollMatchesExprColl(index->indexcollations[indexcol], inputcollid) ||
3442 !op_in_opfamily(matchOpno, index->opfamily[indexcol]) ||
3443 !OidIsValid(arraytype))
3444 break;
3445 firstTime = false;
3446 }
3447 else
3448 {
3449 if (opno != matchOpno ||
3450 inputcollid != subClause->inputcollid ||
3451 consttype != exprType(constExpr))
3452 break;
3453 }
3454
3455 /*
3456 * Check if our list of constants in match_clause_to_indexcol's
3457 * understanding of const-ness have something other than Const.
3458 */
3459 if (!IsA(constExpr, Const))
3460 haveNonConst = true;
3461 consts = lappend(consts, constExpr);
3462 }
3463
3464 /*
3465 * Catch the break from the loop above. Normally, a foreach() loop ends
3466 * up with a NULL list cell. A non-NULL list cell indicates a break from
3467 * the foreach() loop. Free the consts list and return NULL then.
3468 */
3469 if (lc != NULL)
3470 {
3471 list_free(consts);
3472 return NULL;
3473 }
3474
3475 saopexpr = make_SAOP_expr(matchOpno, indexExpr, consttype, inputcollid,
3476 inputcollid, consts, haveNonConst);
3477
3478 /*
3479 * Finally, build an IndexClause based on the SAOP node. Use
3480 * make_simple_restrictinfo() to get RestrictInfo with clean selectivity
3481 * estimations, because they may differ from the estimation made for an OR
3482 * clause. Although it is not a lossy expression, keep the original rinfo
3483 * in iclause->rinfo as prescribed.
3484 */
3485 iclause = makeNode(IndexClause);
3486 iclause->rinfo = rinfo;
3487 iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3488 &saopexpr->xpr));
3489 iclause->lossy = false;
3490 iclause->indexcol = indexcol;
3491 iclause->indexcols = NIL;
3492 return iclause;
3493}
3494
3495/*
3496 * expand_indexqual_rowcompare --- expand a single indexqual condition
3497 * that is a RowCompareExpr
3498 *
3499 * It's already known that the first column of the row comparison matches
3500 * the specified column of the index. We can use additional columns of the
3501 * row comparison as index qualifications, so long as they match the index
3502 * in the "same direction", ie, the indexkeys are all on the same side of the
3503 * clause and the operators are all the same-type members of the opfamilies.
3504 *
3505 * If all the columns of the RowCompareExpr match in this way, we just use it
3506 * as-is, except for possibly commuting it to put the indexkeys on the left.
3507 *
3508 * Otherwise, we build a shortened RowCompareExpr (if more than one
3509 * column matches) or a simple OpExpr (if the first-column match is all
3510 * there is). In these cases the modified clause is always "<=" or ">="
3511 * even when the original was "<" or ">" --- this is necessary to match all
3512 * the rows that could match the original. (We are building a lossy version
3513 * of the row comparison when we do this, so we set lossy = true.)
3514 *
3515 * Note: this is really just the last half of match_rowcompare_to_indexcol,
3516 * but we split it out for comprehensibility.
3517 */
3518static IndexClause *
3519expand_indexqual_rowcompare(PlannerInfo *root,
3520 RestrictInfo *rinfo,
3521 int indexcol,
3522 IndexOptInfo *index,
3523 Oid expr_op,
3524 bool var_on_left)
3525{
3526 IndexClause *iclause = makeNode(IndexClause);
3527 RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3528 int op_strategy;
3529 Oid op_lefttype;
3530 Oid op_righttype;
3531 int matching_cols;
3532 List *expr_ops;
3533 List *opfamilies;
3534 List *lefttypes;
3535 List *righttypes;
3536 List *new_ops;
3537 List *var_args;
3538 List *non_var_args;
3539
3540 iclause->rinfo = rinfo;
3541 iclause->indexcol = indexcol;
3542
3543 if (var_on_left)
3544 {
3545 var_args = clause->largs;
3546 non_var_args = clause->rargs;
3547 }
3548 else
3549 {
3550 var_args = clause->rargs;
3551 non_var_args = clause->largs;
3552 }
3553
3554 get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
3555 &op_strategy,
3556 &op_lefttype,
3557 &op_righttype);
3558
3559 /* Initialize returned list of which index columns are used */
3560 iclause->indexcols = list_make1_int(indexcol);
3561
3562 /* Build lists of ops, opfamilies and operator datatypes in case needed */
3563 expr_ops = list_make1_oid(expr_op);
3564 opfamilies = list_make1_oid(index->opfamily[indexcol]);
3565 lefttypes = list_make1_oid(op_lefttype);
3566 righttypes = list_make1_oid(op_righttype);
3567
3568 /*
3569 * See how many of the remaining columns match some index column in the
3570 * same way. As in match_clause_to_indexcol(), the "other" side of any
3571 * potential index condition is OK as long as it doesn't use Vars from the
3572 * indexed relation.
3573 */
3574 matching_cols = 1;
3575
3576 while (matching_cols < list_length(var_args))
3577 {
3578 Node *varop = (Node *) list_nth(var_args, matching_cols);
3579 Node *constop = (Node *) list_nth(non_var_args, matching_cols);
3580 int i;
3581
3582 expr_op = list_nth_oid(clause->opnos, matching_cols);
3583 if (!var_on_left)
3584 {
3585 /* indexkey is on right, so commute the operator */
3586 expr_op = get_commutator(expr_op);
3587 if (expr_op == InvalidOid)
3588 break; /* operator is not usable */
3589 }
3590 if (bms_is_member(index->rel->relid, pull_varnos(root, constop)))
3591 break; /* no good, Var on wrong side */
3592 if (contain_volatile_functions(constop))
3593 break; /* no good, volatile comparison value */
3594
3595 /*
3596 * The Var side can match any key column of the index.
3597 */
3598 for (i = 0; i < index->nkeycolumns; i++)
3599 {
3600 if (match_index_to_operand(varop, i, index) &&
3601 get_op_opfamily_strategy(expr_op,
3602 index->opfamily[i]) == op_strategy &&
3603 IndexCollMatchesExprColl(index->indexcollations[i],
3604 list_nth_oid(clause->inputcollids,
3605 matching_cols)))
3606 break;
3607 }
3608 if (i >= index->nkeycolumns)
3609 break; /* no match found */
3610
3611 /* Add column number to returned list */
3612 iclause->indexcols = lappend_int(iclause->indexcols, i);
3613
3614 /* Add operator info to lists */
3615 get_op_opfamily_properties(expr_op, index->opfamily[i], false,
3616 &op_strategy,
3617 &op_lefttype,
3618 &op_righttype);
3619 expr_ops = lappend_oid(expr_ops, expr_op);
3620 opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
3621 lefttypes = lappend_oid(lefttypes, op_lefttype);
3622 righttypes = lappend_oid(righttypes, op_righttype);
3623
3624 /* This column matches, keep scanning */
3625 matching_cols++;
3626 }
3627
3628 /* Result is non-lossy if all columns are usable as index quals */
3629 iclause->lossy = (matching_cols != list_length(clause->opnos));
3630
3631 /*
3632 * We can use rinfo->clause as-is if we have var on left and it's all
3633 * usable as index quals.
3634 */
3635 if (var_on_left && !iclause->lossy)
3636 iclause->indexquals = list_make1(rinfo);
3637 else
3638 {
3639 /*
3640 * We have to generate a modified rowcompare (possibly just one
3641 * OpExpr). The painful part of this is changing < to <= or > to >=,
3642 * so deal with that first.
3643 */
3644 if (!iclause->lossy)
3645 {
3646 /* very easy, just use the commuted operators */
3647 new_ops = expr_ops;
3648 }
3649 else if (op_strategy == BTLessEqualStrategyNumber ||
3650 op_strategy == BTGreaterEqualStrategyNumber)
3651 {
3652 /* easy, just use the same (possibly commuted) operators */
3653 new_ops = list_truncate(expr_ops, matching_cols);
3654 }
3655 else
3656 {
3657 ListCell *opfamilies_cell;
3658 ListCell *lefttypes_cell;
3659 ListCell *righttypes_cell;
3660
3661 if (op_strategy == BTLessStrategyNumber)
3662 op_strategy = BTLessEqualStrategyNumber;
3663 else if (op_strategy == BTGreaterStrategyNumber)
3664 op_strategy = BTGreaterEqualStrategyNumber;
3665 else
3666 elog(ERROR, "unexpected strategy number %d", op_strategy);
3667 new_ops = NIL;
3668 forthree(opfamilies_cell, opfamilies,
3669 lefttypes_cell, lefttypes,
3670 righttypes_cell, righttypes)
3671 {
3672 Oid opfam = lfirst_oid(opfamilies_cell);
3673 Oid lefttype = lfirst_oid(lefttypes_cell);
3674 Oid righttype = lfirst_oid(righttypes_cell);
3675
3676 expr_op = get_opfamily_member(opfam, lefttype, righttype,
3677 op_strategy);
3678 if (!OidIsValid(expr_op)) /* should not happen */
3679 elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3680 op_strategy, lefttype, righttype, opfam);
3681 new_ops = lappend_oid(new_ops, expr_op);
3682 }
3683 }
3684
3685 /* If we have more than one matching col, create a subset rowcompare */
3686 if (matching_cols > 1)
3687 {
3688 RowCompareExpr *rc = makeNode(RowCompareExpr);
3689
3690 rc->cmptype = (CompareType) op_strategy;
3691 rc->opnos = new_ops;
3692 rc->opfamilies = list_copy_head(clause->opfamilies,
3693 matching_cols);
3694 rc->inputcollids = list_copy_head(clause->inputcollids,
3695 matching_cols);
3696 rc->largs = list_copy_head(var_args, matching_cols);
3697 rc->rargs = list_copy_head(non_var_args, matching_cols);
3698 iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3699 (Expr *) rc));
3700 }
3701 else
3702 {
3703 Expr *op;
3704
3705 /* We don't report an index column list in this case */
3706 iclause->indexcols = NIL;
3707
3708 op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
3709 copyObject(linitial(var_args)),
3710 copyObject(linitial(non_var_args)),
3711 InvalidOid,
3712 linitial_oid(clause->inputcollids));
3713 iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
3714 }
3715 }
3716
3717 return iclause;
3718}
3719
3720
3721/****************************************************************************
3722 * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3723 ****************************************************************************/
3724
3725/*
3726 * match_pathkeys_to_index
3727 * For the given 'index' and 'pathkeys', output a list of suitable ORDER
3728 * BY expressions, each of the form "indexedcol operator pseudoconstant",
3729 * along with an integer list of the index column numbers (zero based)
3730 * that each clause would be used with.
3731 *
3732 * This attempts to find an ORDER BY and index column number for all items in
3733 * the pathkey list, however, if we're unable to match any given pathkey to an
3734 * index column, we return just the ones matched by the function so far. This
3735 * allows callers who are interested in partial matches to get them. Callers
3736 * can determine a partial match vs a full match by checking the outputted
3737 * list lengths. A full match will have one item in the output lists for each
3738 * item in the given 'pathkeys' list.
3739 */
3740static void
3741match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3742 List **orderby_clauses_p,
3743 List **clause_columns_p)
3744{
3745 ListCell *lc1;
3746
3747 *orderby_clauses_p = NIL; /* set default results */
3748 *clause_columns_p = NIL;
3749
3750 /* Only indexes with the amcanorderbyop property are interesting here */
3751 if (!index->amcanorderbyop)
3752 return;
3753
3754 foreach(lc1, pathkeys)
3755 {
3756 PathKey *pathkey = (PathKey *) lfirst(lc1);
3757 bool found = false;
3758 EquivalenceMemberIterator it;
3759 EquivalenceMember *member;
3760
3761
3762 /* Pathkey must request default sort order for the target opfamily */
3763 if (pathkey->pk_cmptype != COMPARE_LT || pathkey->pk_nulls_first)
3764 return;
3765
3766 /* If eclass is volatile, no hope of using an indexscan */
3767 if (pathkey->pk_eclass->ec_has_volatile)
3768 return;
3769
3770 /*
3771 * Try to match eclass member expression(s) to index. Note that child
3772 * EC members are considered, but only when they belong to the target
3773 * relation. (Unlike regular members, the same expression could be a
3774 * child member of more than one EC. Therefore, the same index could
3775 * be considered to match more than one pathkey list, which is OK
3776 * here. See also get_eclass_for_sort_expr.)
3777 */
3778 setup_eclass_member_iterator(&it, pathkey->pk_eclass,
3779 index->rel->relids);
3780 while ((member = eclass_member_iterator_next(&it)) != NULL)
3781 {
3782 int indexcol;
3783
3784 /* No possibility of match if it references other relations */
3785 if (!bms_equal(member->em_relids, index->rel->relids))
3786 continue;
3787
3788 /*
3789 * We allow any column of the index to match each pathkey; they
3790 * don't have to match left-to-right as you might expect. This is
3791 * correct for GiST, and it doesn't matter for SP-GiST because
3792 * that doesn't handle multiple columns anyway, and no other
3793 * existing AMs support amcanorderbyop. We might need different
3794 * logic in future for other implementations.
3795 */
3796 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3797 {
3798 Expr *expr;
3799
3800 expr = match_clause_to_ordering_op(index,
3801 indexcol,
3802 member->em_expr,
3803 pathkey->pk_opfamily);
3804 if (expr)
3805 {
3806 *orderby_clauses_p = lappend(*orderby_clauses_p, expr);
3807 *clause_columns_p = lappend_int(*clause_columns_p, indexcol);
3808 found = true;
3809 break;
3810 }
3811 }
3812
3813 if (found) /* don't want to look at remaining members */
3814 break;
3815 }
3816
3817 /*
3818 * Return the matches found so far when this pathkey couldn't be
3819 * matched to the index.
3820 */
3821 if (!found)
3822 return;
3823 }
3824}
3825
3826/*
3827 * match_clause_to_ordering_op
3828 * Determines whether an ordering operator expression matches an
3829 * index column.
3830 *
3831 * This is similar to, but simpler than, match_clause_to_indexcol.
3832 * We only care about simple OpExpr cases. The input is a bare
3833 * expression that is being ordered by, which must be of the form
3834 * (indexkey op const) or (const op indexkey) where op is an ordering
3835 * operator for the column's opfamily.
3836 *
3837 * 'index' is the index of interest.
3838 * 'indexcol' is a column number of 'index' (counting from 0).
3839 * 'clause' is the ordering expression to be tested.
3840 * 'pk_opfamily' is the btree opfamily describing the required sort order.
3841 *
3842 * Note that we currently do not consider the collation of the ordering
3843 * operator's result. In practical cases the result type will be numeric
3844 * and thus have no collation, and it's not very clear what to match to
3845 * if it did have a collation. The index's collation should match the
3846 * ordering operator's input collation, not its result.
3847 *
3848 * If successful, return 'clause' as-is if the indexkey is on the left,
3849 * otherwise a commuted copy of 'clause'. If no match, return NULL.
3850 */
3851static Expr *
3852match_clause_to_ordering_op(IndexOptInfo *index,
3853 int indexcol,
3854 Expr *clause,
3855 Oid pk_opfamily)
3856{
3857 Oid opfamily;
3858 Oid idxcollation;
3859 Node *leftop,
3860 *rightop;
3861 Oid expr_op;
3862 Oid expr_coll;
3863 Oid sortfamily;
3864 bool commuted;
3865
3866 Assert(indexcol < index->nkeycolumns);
3867
3868 opfamily = index->opfamily[indexcol];
3869 idxcollation = index->indexcollations[indexcol];
3870
3871 /*
3872 * Clause must be a binary opclause.
3873 */
3874 if (!is_opclause(clause))
3875 return NULL;
3876 leftop = get_leftop(clause);
3877 rightop = get_rightop(clause);
3878 if (!leftop || !rightop)
3879 return NULL;
3880 expr_op = ((OpExpr *) clause)->opno;
3881 expr_coll = ((OpExpr *) clause)->inputcollid;
3882
3883 /*
3884 * We can forget the whole thing right away if wrong collation.
3885 */
3886 if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3887 return NULL;
3888
3889 /*
3890 * Check for clauses of the form: (indexkey operator constant) or
3891 * (constant operator indexkey).
3892 */
3893 if (match_index_to_operand(leftop, indexcol, index) &&
3894 !contain_var_clause(rightop) &&
3895 !contain_volatile_functions(rightop))
3896 {
3897 commuted = false;
3898 }
3899 else if (match_index_to_operand(rightop, indexcol, index) &&
3900 !contain_var_clause(leftop) &&
3901 !contain_volatile_functions(leftop))
3902 {
3903 /* Might match, but we need a commuted operator */
3904 expr_op = get_commutator(expr_op);
3905 if (expr_op == InvalidOid)
3906 return NULL;
3907 commuted = true;
3908 }
3909 else
3910 return NULL;
3911
3912 /*
3913 * Is the (commuted) operator an ordering operator for the opfamily? And
3914 * if so, does it yield the right sorting semantics?
3915 */
3916 sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3917 if (sortfamily != pk_opfamily)
3918 return NULL;
3919
3920 /* We have a match. Return clause or a commuted version thereof. */
3921 if (commuted)
3922 {
3923 OpExpr *newclause = makeNode(OpExpr);
3924
3925 /* flat-copy all the fields of clause */
3926 memcpy(newclause, clause, sizeof(OpExpr));
3927
3928 /* commute it */
3929 newclause->opno = expr_op;
3930 newclause->opfuncid = InvalidOid;
3931 newclause->args = list_make2(rightop, leftop);
3932
3933 clause = (Expr *) newclause;
3934 }
3935
3936 return clause;
3937}
3938
3939
3940/****************************************************************************
3941 * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3942 ****************************************************************************/
3943
3944/*
3945 * check_index_predicates
3946 * Set the predicate-derived IndexOptInfo fields for each index
3947 * of the specified relation.
3948 *
3949 * predOK is set true if the index is partial and its predicate is satisfied
3950 * for this query, ie the query's WHERE clauses imply the predicate.
3951 *
3952 * indrestrictinfo is set to the relation's baserestrictinfo list less any
3953 * conditions that are implied by the index's predicate. (Obviously, for a
3954 * non-partial index, this is the same as baserestrictinfo.) Such conditions
3955 * can be dropped from the plan when using the index, in certain cases.
3956 *
3957 * At one time it was possible for this to get re-run after adding more
3958 * restrictions to the rel, thus possibly letting us prove more indexes OK.
3959 * That doesn't happen any more (at least not in the core code's usage),
3960 * but this code still supports it in case extensions want to mess with the
3961 * baserestrictinfo list. We assume that adding more restrictions can't make
3962 * an index not predOK. We must recompute indrestrictinfo each time, though,
3963 * to make sure any newly-added restrictions get into it if needed.
3964 */
3965void
3966check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3967{
3968 List *clauselist;
3969 bool have_partial;
3970 bool is_target_rel;
3971 Relids otherrels;
3972 ListCell *lc;
3973
3974 /* Indexes are available only on base or "other" member relations. */
3975 Assert(IS_SIMPLE_REL(rel));
3976
3977 /*
3978 * Initialize the indrestrictinfo lists to be identical to
3979 * baserestrictinfo, and check whether there are any partial indexes. If
3980 * not, this is all we need to do.
3981 */
3982 have_partial = false;
3983 foreach(lc, rel->indexlist)
3984 {
3985 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3986
3987 index->indrestrictinfo = rel->baserestrictinfo;
3988 if (index->indpred)
3989 have_partial = true;
3990 }
3991 if (!have_partial)
3992 return;
3993
3994 /*
3995 * Construct a list of clauses that we can assume true for the purpose of
3996 * proving the index(es) usable. Restriction clauses for the rel are
3997 * always usable, and so are any join clauses that are "movable to" this
3998 * rel. Also, we can consider any EC-derivable join clauses (which must
3999 * be "movable to" this rel, by definition).
4000 */
4001 clauselist = list_copy(rel->baserestrictinfo);
4002
4003 /* Scan the rel's join clauses */
4004 foreach(lc, rel->joininfo)
4005 {
4006 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4007
4008 /* Check if clause can be moved to this rel */
4009 if (!join_clause_is_movable_to(rinfo, rel))
4010 continue;
4011
4012 clauselist = lappend(clauselist, rinfo);
4013 }
4014
4015 /*
4016 * Add on any equivalence-derivable join clauses. Computing the correct
4017 * relid sets for generate_join_implied_equalities is slightly tricky
4018 * because the rel could be a child rel rather than a true baserel, and in
4019 * that case we must subtract its parents' relid(s) from all_query_rels.
4020 * Additionally, we mustn't consider clauses that are only computable
4021 * after outer joins that can null the rel.
4022 */
4023 if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
4024 otherrels = bms_difference(root->all_query_rels,
4025 find_childrel_parents(root, rel));
4026 else
4027 otherrels = bms_difference(root->all_query_rels, rel->relids);
4028 otherrels = bms_del_members(otherrels, rel->nulling_relids);
4029
4030 if (!bms_is_empty(otherrels))
4031 clauselist =
4032 list_concat(clauselist,
4033 generate_join_implied_equalities(root,
4034 bms_union(rel->relids,
4035 otherrels),
4036 otherrels,
4037 rel,
4038 NULL));
4039
4040 /*
4041 * Normally we remove quals that are implied by a partial index's
4042 * predicate from indrestrictinfo, indicating that they need not be
4043 * checked explicitly by an indexscan plan using this index. However, if
4044 * the rel is a target relation of UPDATE/DELETE/MERGE/SELECT FOR UPDATE,
4045 * we cannot remove such quals from the plan, because they need to be in
4046 * the plan so that they will be properly rechecked by EvalPlanQual
4047 * testing. Some day we might want to remove such quals from the main
4048 * plan anyway and pass them through to EvalPlanQual via a side channel;
4049 * but for now, we just don't remove implied quals at all for target
4050 * relations.
4051 */
4052 is_target_rel = (bms_is_member(rel->relid, root->all_result_relids) ||
4053 get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
4054
4055 /*
4056 * Now try to prove each index predicate true, and compute the
4057 * indrestrictinfo lists for partial indexes. Note that we compute the
4058 * indrestrictinfo list even for non-predOK indexes; this might seem
4059 * wasteful, but we may be able to use such indexes in OR clauses, cf
4060 * generate_bitmap_or_paths().
4061 */
4062 foreach(lc, rel->indexlist)
4063 {
4064 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
4065 ListCell *lcr;
4066
4067 if (index->indpred == NIL)
4068 continue; /* ignore non-partial indexes here */
4069
4070 if (!index->predOK) /* don't repeat work if already proven OK */
4071 index->predOK = predicate_implied_by(index->indpred, clauselist,
4072 false);
4073
4074 /* If rel is an update target, leave indrestrictinfo as set above */
4075 if (is_target_rel)
4076 continue;
4077
4078 /* Else compute indrestrictinfo as the non-implied quals */
4079 index->indrestrictinfo = NIL;
4080 foreach(lcr, rel->baserestrictinfo)
4081 {
4082 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
4083
4084 /* predicate_implied_by() assumes first arg is immutable */
4085 if (contain_mutable_functions((Node *) rinfo->clause) ||
4086 !predicate_implied_by(list_make1(rinfo->clause),
4087 index->indpred, false))
4088 index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
4089 }
4090 }
4091}
4092
4093/****************************************************************************
4094 * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
4095 ****************************************************************************/
4096
4097/*
4098 * ec_member_matches_indexcol
4099 * Test whether an EquivalenceClass member matches an index column.
4100 *
4101 * This is a callback for use by generate_implied_equalities_for_column.
4102 */
4103static bool
4104ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
4105 EquivalenceClass *ec, EquivalenceMember *em,
4106 void *arg)
4107{
4108 IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
4109 int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
4110 Oid curFamily;
4111 Oid curCollation;
4112
4113 Assert(indexcol < index->nkeycolumns);
4114
4115 curFamily = index->opfamily[indexcol];
4116 curCollation = index->indexcollations[indexcol];
4117
4118 /*
4119 * If it's a btree index, we can reject it if its opfamily isn't
4120 * compatible with the EC, since no clause generated from the EC could be
4121 * used with the index. For non-btree indexes, we can't easily tell
4122 * whether clauses generated from the EC could be used with the index, so
4123 * don't check the opfamily. This might mean we return "true" for a
4124 * useless EC, so we have to recheck the results of
4125 * generate_implied_equalities_for_column; see
4126 * match_eclass_clauses_to_index.
4127 */
4128 if (index->relam == BTREE_AM_OID &&
4129 !list_member_oid(ec->ec_opfamilies, curFamily))
4130 return false;
4131
4132 /* We insist on collation match for all index types, though */
4133 if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
4134 return false;
4135
4136 return match_index_to_operand((Node *) em->em_expr, indexcol, index);
4137}
4138
4139/*
4140 * relation_has_unique_index_for
4141 * Determine whether the relation provably has at most one row satisfying
4142 * a set of equality conditions, because the conditions constrain all
4143 * columns of some unique index.
4144 *
4145 * The conditions can be represented in either or both of two ways:
4146 * 1. A list of RestrictInfo nodes, where the caller has already determined
4147 * that each condition is a mergejoinable equality with an expression in
4148 * this relation on one side, and an expression not involving this relation
4149 * on the other. The transient outer_is_left flag is used to identify which
4150 * side we should look at: left side if outer_is_left is false, right side
4151 * if it is true.
4152 * 2. A list of expressions in this relation, and a corresponding list of
4153 * equality operators. The caller must have already checked that the operators
4154 * represent equality. (Note: the operators could be cross-type; the
4155 * expressions should correspond to their RHS inputs.)
4156 *
4157 * The caller need only supply equality conditions arising from joins;
4158 * this routine automatically adds in any usable baserestrictinfo clauses.
4159 * (Note that the passed-in restrictlist will be destructively modified!)
4160 */
4161bool
4162relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
4163 List *restrictlist,
4164 List *exprlist, List *oprlist)
4165{
4166 return relation_has_unique_index_ext(root, rel, restrictlist,
4167 exprlist, oprlist, NULL);
4168}
4169
4170/*
4171 * relation_has_unique_index_ext
4172 * Same as relation_has_unique_index_for(), but supports extra_clauses
4173 * parameter. If extra_clauses isn't NULL, return baserestrictinfo clauses
4174 * which were used to derive uniqueness.
4175 */
4176bool
4177relation_has_unique_index_ext(PlannerInfo *root, RelOptInfo *rel,
4178 List *restrictlist,
4179 List *exprlist, List *oprlist,
4180 List **extra_clauses)
4181{
4182 ListCell *ic;
4183
4184 Assert(list_length(exprlist) == list_length(oprlist));
4185
4186 /* Short-circuit if no indexes... */
4187 if (rel->indexlist == NIL)
4188 return false;
4189
4190 /*
4191 * Examine the rel's restriction clauses for usable var = const clauses
4192 * that we can add to the restrictlist.
4193 */
4194 foreach(ic, rel->baserestrictinfo)
4195 {
4196 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
4197
4198 /*
4199 * Note: can_join won't be set for a restriction clause, but
4200 * mergeopfamilies will be if it has a mergejoinable operator and
4201 * doesn't contain volatile functions.
4202 */
4203 if (restrictinfo->mergeopfamilies == NIL)
4204 continue; /* not mergejoinable */
4205
4206 /*
4207 * The clause certainly doesn't refer to anything but the given rel.
4208 * If either side is pseudoconstant then we can use it.
4209 */
4210 if (bms_is_empty(restrictinfo->left_relids))
4211 {
4212 /* righthand side is inner */
4213 restrictinfo->outer_is_left = true;
4214 }
4215 else if (bms_is_empty(restrictinfo->right_relids))
4216 {
4217 /* lefthand side is inner */
4218 restrictinfo->outer_is_left = false;
4219 }
4220 else
4221 continue;
4222
4223 /* OK, add to list */
4224 restrictlist = lappend(restrictlist, restrictinfo);
4225 }
4226
4227 /* Short-circuit the easy case */
4228 if (restrictlist == NIL && exprlist == NIL)
4229 return false;
4230
4231 /* Examine each index of the relation ... */
4232 foreach(ic, rel->indexlist)
4233 {
4234 IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
4235 int c;
4236 List *exprs = NIL;
4237
4238 /*
4239 * If the index is not unique, or not immediately enforced, or if it's
4240 * a partial index, it's useless here. We're unable to make use of
4241 * predOK partial unique indexes due to the fact that
4242 * check_index_predicates() also makes use of join predicates to
4243 * determine if the partial index is usable. Here we need proofs that
4244 * hold true before any joins are evaluated.
4245 */
4246 if (!ind->unique || !ind->immediate || ind->indpred != NIL)
4247 continue;
4248
4249 /*
4250 * Try to find each index column in the lists of conditions. This is
4251 * O(N^2) or worse, but we expect all the lists to be short.
4252 */
4253 for (c = 0; c < ind->nkeycolumns; c++)
4254 {
4255 bool matched = false;
4256 ListCell *lc;
4257 ListCell *lc2;
4258
4259 foreach(lc, restrictlist)
4260 {
4261 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4262 Node *rexpr;
4263
4264 /*
4265 * The condition's equality operator must be a member of the
4266 * index opfamily, else it is not asserting the right kind of
4267 * equality behavior for this index. We check this first
4268 * since it's probably cheaper than match_index_to_operand().
4269 */
4270 if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
4271 continue;
4272
4273 /*
4274 * XXX at some point we may need to check collations here too.
4275 * For the moment we assume all collations reduce to the same
4276 * notion of equality.
4277 */
4278
4279 /* OK, see if the condition operand matches the index key */
4280 if (rinfo->outer_is_left)
4281 rexpr = get_rightop(rinfo->clause);
4282 else
4283 rexpr = get_leftop(rinfo->clause);
4284
4285 if (match_index_to_operand(rexpr, c, ind))
4286 {
4287 matched = true; /* column is unique */
4288
4289 if (bms_membership(rinfo->clause_relids) == BMS_SINGLETON)
4290 {
4291 MemoryContext oldMemCtx =
4292 MemoryContextSwitchTo(root->planner_cxt);
4293
4294 /*
4295 * Add filter clause into a list allowing caller to
4296 * know if uniqueness have made not only by join
4297 * clauses.
4298 */
4299 Assert(bms_is_empty(rinfo->left_relids) ||
4300 bms_is_empty(rinfo->right_relids));
4301 if (extra_clauses)
4302 exprs = lappend(exprs, rinfo);
4303 MemoryContextSwitchTo(oldMemCtx);
4304 }
4305
4306 break;
4307 }
4308 }
4309
4310 if (matched)
4311 continue;
4312
4313 forboth(lc, exprlist, lc2, oprlist)
4314 {
4315 Node *expr = (Node *) lfirst(lc);
4316 Oid opr = lfirst_oid(lc2);
4317
4318 /* See if the expression matches the index key */
4319 if (!match_index_to_operand(expr, c, ind))
4320 continue;
4321
4322 /*
4323 * The equality operator must be a member of the index
4324 * opfamily, else it is not asserting the right kind of
4325 * equality behavior for this index. We assume the caller
4326 * determined it is an equality operator, so we don't need to
4327 * check any more tightly than this.
4328 */
4329 if (!op_in_opfamily(opr, ind->opfamily[c]))
4330 continue;
4331
4332 /*
4333 * XXX at some point we may need to check collations here too.
4334 * For the moment we assume all collations reduce to the same
4335 * notion of equality.
4336 */
4337
4338 matched = true; /* column is unique */
4339 break;
4340 }
4341
4342 if (!matched)
4343 break; /* no match; this index doesn't help us */
4344 }
4345
4346 /* Matched all key columns of this index? */
4347 if (c == ind->nkeycolumns)
4348 {
4349 if (extra_clauses)
4350 *extra_clauses = exprs;
4351 return true;
4352 }
4353 }
4354
4355 return false;
4356}
4357
4358/*
4359 * indexcol_is_bool_constant_for_query
4360 *
4361 * If an index column is constrained to have a constant value by the query's
4362 * WHERE conditions, then it's irrelevant for sort-order considerations.
4363 * Usually that means we have a restriction clause WHERE indexcol = constant,
4364 * which gets turned into an EquivalenceClass containing a constant, which
4365 * is recognized as redundant by build_index_pathkeys(). But if the index
4366 * column is a boolean variable (or expression), then we are not going to
4367 * see WHERE indexcol = constant, because expression preprocessing will have
4368 * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
4369 * going to have a matching EquivalenceClass (unless the query also contains
4370 * "ORDER BY indexcol"). To allow such cases to work the same as they would
4371 * for non-boolean values, this function is provided to detect whether the
4372 * specified index column matches a boolean restriction clause.
4373 */
4374bool
4375indexcol_is_bool_constant_for_query(PlannerInfo *root,
4376 IndexOptInfo *index,
4377 int indexcol)
4378{
4379 ListCell *lc;
4380
4381 /* If the index isn't boolean, we can't possibly get a match */
4382 if (!IsBooleanOpfamily(index->opfamily[indexcol]))
4383 return false;
4384
4385 /* Check each restriction clause for the index's rel */
4386 foreach(lc, index->rel->baserestrictinfo)
4387 {
4388 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4389
4390 /*
4391 * As in match_clause_to_indexcol, never match pseudoconstants to
4392 * indexes. (It might be semantically okay to do so here, but the
4393 * odds of getting a match are negligible, so don't waste the cycles.)
4394 */
4395 if (rinfo->pseudoconstant)
4396 continue;
4397
4398 /* See if we can match the clause's expression to the index column */
4399 if (match_boolean_index_clause(root, rinfo, indexcol, index))
4400 return true;
4401 }
4402
4403 return false;
4404}
4405
4406
4407/****************************************************************************
4408 * ---- ROUTINES TO CHECK OPERANDS ----
4409 ****************************************************************************/
4410
4411/*
4412 * match_index_to_operand()
4413 * Generalized test for a match between an index's key
4414 * and the operand on one side of a restriction or join clause.
4415 *
4416 * operand: the nodetree to be compared to the index
4417 * indexcol: the column number of the index (counting from 0)
4418 * index: the index of interest
4419 *
4420 * Note that we aren't interested in collations here; the caller must check
4421 * for a collation match, if it's dealing with an operator where that matters.
4422 *
4423 * This is exported for use in selfuncs.c.
4424 */
4425bool
4426match_index_to_operand(Node *operand,
4427 int indexcol,
4428 IndexOptInfo *index)
4429{
4430 int indkey;
4431
4432 /*
4433 * Ignore any RelabelType node above the operand. This is needed to be
4434 * able to apply indexscanning in binary-compatible-operator cases. Note:
4435 * we can assume there is at most one RelabelType node;
4436 * eval_const_expressions() will have simplified if more than one.
4437 */
4438 if (operand && IsA(operand, RelabelType))
4439 operand = (Node *) ((RelabelType *) operand)->arg;
4440
4441 indkey = index->indexkeys[indexcol];
4442 if (indkey != 0)
4443 {
4444 /*
4445 * Simple index column; operand must be a matching Var.
4446 */
4447 if (operand && IsA(operand, Var) &&
4448 index->rel->relid == ((Var *) operand)->varno &&
4449 indkey == ((Var *) operand)->varattno &&
4450 ((Var *) operand)->varnullingrels == NULL)
4451 return true;
4452 }
4453 else
4454 {
4455 /*
4456 * Index expression; find the correct expression. (This search could
4457 * be avoided, at the cost of complicating all the callers of this
4458 * routine; doesn't seem worth it.)
4459 */
4460 ListCell *indexpr_item;
4461 int i;
4462 Node *indexkey;
4463
4464 indexpr_item = list_head(index->indexprs);
4465 for (i = 0; i < indexcol; i++)
4466 {
4467 if (index->indexkeys[i] == 0)
4468 {
4469 if (indexpr_item == NULL)
4470 elog(ERROR, "wrong number of index expressions");
4471 indexpr_item = lnext(index->indexprs, indexpr_item);
4472 }
4473 }
4474 if (indexpr_item == NULL)
4475 elog(ERROR, "wrong number of index expressions");
4476 indexkey = (Node *) lfirst(indexpr_item);
4477
4478 /*
4479 * Does it match the operand? Again, strip any relabeling.
4480 */
4481 if (indexkey && IsA(indexkey, RelabelType))
4482 indexkey = (Node *) ((RelabelType *) indexkey)->arg;
4483
4484 if (equal(indexkey, operand))
4485 return true;
4486 }
4487
4488 return false;
4489}
4490
4491/*
4492 * is_pseudo_constant_for_index()
4493 * Test whether the given expression can be used as an indexscan
4494 * comparison value.
4495 *
4496 * An indexscan comparison value must not contain any volatile functions,
4497 * and it can't contain any Vars of the index's own table. Vars of
4498 * other tables are okay, though; in that case we'd be producing an
4499 * indexqual usable in a parameterized indexscan. This is, therefore,
4500 * a weaker condition than is_pseudo_constant_clause().
4501 *
4502 * This function is exported for use by planner support functions,
4503 * which will have available the IndexOptInfo, but not any RestrictInfo
4504 * infrastructure. It is making the same test made by functions above
4505 * such as match_opclause_to_indexcol(), but those rely where possible
4506 * on RestrictInfo information about variable membership.
4507 *
4508 * expr: the nodetree to be checked
4509 * index: the index of interest
4510 */
4511bool
4512is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
4513{
4514 /* pull_varnos is cheaper than volatility check, so do that first */
4515 if (bms_is_member(index->rel->relid, pull_varnos(root, expr)))
4516 return false; /* no good, contains Var of table */
4517 if (contain_volatile_functions(expr))
4518 return false; /* no good, volatile comparison value */
4519 return true;
4520}
create_partial_bitmap_paths
void create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual)
Definition: allpaths.c:4198
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:1306
bms_del_members
Bitmapset * bms_del_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:1161
bms_del_member
Bitmapset * bms_del_member(Bitmapset *a, int x)
Definition: bitmapset.c:868
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:815
bms_add_members
Bitmapset * bms_add_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:917
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:781
bms_overlap
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:582
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
Index
unsigned int Index
Definition: c.h:585
MemSet
#define MemSet(start, val, len)
Definition: c.h:991
OidIsValid
#define OidIsValid(objectId)
Definition: c.h:746
contain_mutable_functions
bool contain_mutable_functions(Node *clause)
Definition: clauses.c:371
make_SAOP_expr
ScalarArrayOpExpr * make_SAOP_expr(Oid oper, Node *leftexpr, Oid coltype, Oid arraycollid, Oid inputcollid, List *exprs, bool haveNonConst)
Definition: clauses.c:5453
contain_volatile_functions
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:539
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:1122
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:1023
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:3156
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:3239
eclass_member_iterator_next
EquivalenceMember * eclass_member_iterator_next(EquivalenceMemberIterator *it)
Definition: equivclass.c:3175
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:1550
OidFunctionCall1
#define OidFunctionCall1(functionId, arg1)
Definition: fmgr.h:720
Assert
Assert(PointerIsAligned(start, uint64))
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:1784
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:605
or_arg_index_match_cmp
static int or_arg_index_match_cmp(const void *a, const void *b)
Definition: indxpath.c:1199
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:4512
eclass_already_used
static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids, List *indexjoinclauses)
Definition: indxpath.c:683
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:46
ST_ANYSCAN
@ ST_ANYSCAN
Definition: indxpath.c:49
ST_BITMAPSCAN
@ ST_BITMAPSCAN
Definition: indxpath.c:48
ST_INDEXSCAN
@ ST_INDEXSCAN
Definition: indxpath.c:47
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:715
check_index_predicates
void check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:3966
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:809
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:3741
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
relation_has_unique_index_for
bool relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel, List *restrictlist, List *exprlist, List *oprlist)
Definition: indxpath.c:4162
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:502
create_index_paths
void create_index_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:239
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:4104
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:41
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:4426
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:436
or_arg_index_match_cmp_group
static int or_arg_index_match_cmp_group(const void *a, const void *b)
Definition: indxpath.c:1237
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:3519
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:1091
indexcol_is_bool_constant_for_query
bool indexcol_is_bool_constant_for_query(PlannerInfo *root, IndexOptInfo *index, int indexcol)
Definition: indxpath.c:4375
relation_has_unique_index_ext
bool relation_has_unique_index_ext(PlannerInfo *root, RelOptInfo *rel, List *restrictlist, List *exprlist, List *oprlist, List **extra_clauses)
Definition: indxpath.c:4177
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
group_similar_or_args
static List * group_similar_or_args(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *rinfo)
Definition: indxpath.c:1270
approximate_joinrel_size
static double approximate_joinrel_size(PlannerInfo *root, Relids relids)
Definition: indxpath.c:2423
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static Expr * match_clause_to_ordering_op(IndexOptInfo *index, int indexcol, Expr *clause, Oid pk_opfamily)
Definition: indxpath.c:3852
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static List * generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel, List *clauses, List *other_clauses)
Definition: indxpath.c:1628
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:1547
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
if
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:81
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:137
get_op_opfamily_sortfamily
Oid get_op_opfamily_sortfamily(Oid opno, Oid opfamily)
Definition: lsyscache.c:109
type_is_rowtype
bool type_is_rowtype(Oid typid)
Definition: lsyscache.c:2795
get_func_support
RegProcedure get_func_support(Oid funcid)
Definition: lsyscache.c:1998
get_op_rettype
Oid get_op_rettype(Oid opno)
Definition: lsyscache.c:1473
get_op_opfamily_strategy
int get_op_opfamily_strategy(Oid opno, Oid opfamily)
Definition: lsyscache.c:84
get_opfamily_member
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition: lsyscache.c:167
get_array_type
Oid get_array_type(Oid typid)
Definition: lsyscache.c:2927
op_in_opfamily
bool op_in_opfamily(Oid opno, Oid opfamily)
Definition: lsyscache.c:67
get_commutator
Oid get_commutator(Oid opno)
Definition: lsyscache.c:1649
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:2147
palloc
void * palloc(Size size)
Definition: mcxt.c:1940
generate_unaccent_rules.args
args
Definition: generate_unaccent_rules.py:288
exprType
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
set_opfuncid
void set_opfuncid(OpExpr *opexpr)
Definition: nodeFuncs.c:1872
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
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:230
Cost
double Cost
Definition: nodes.h:257
nodeTag
#define nodeTag(nodeptr)
Definition: nodes.h:139
Selectivity
double Selectivity
Definition: nodes.h:256
makeNode
#define makeNode(_type_)
Definition: nodes.h:161
castNode
#define castNode(_type_, nodeptr)
Definition: nodes.h:182
JOIN_SEMI
@ JOIN_SEMI
Definition: nodes.h:313
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:2270
has_useful_pathkeys
bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel)
Definition: pathkeys.c:2319
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:1131
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:1049
add_partial_path
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:795
create_bitmap_or_path
BitmapOrPath * create_bitmap_or_path(PlannerInfo *root, RelOptInfo *rel, List *bitmapquals)
Definition: pathnode.c:1183
create_bitmap_heap_path
BitmapHeapPath * create_bitmap_heap_path(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual, Relids required_outer, double loop_count, int parallel_degree)
Definition: pathnode.c:1098
add_path
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:461
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:866
IS_DUMMY_REL
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:2083
PATH_REQ_OUTER
#define PATH_REQ_OUTER(path)
Definition: pathnodes.h:1806
Relids
Bitmapset * Relids
Definition: pathnodes.h:30
RELOPT_OTHER_MEMBER_REL
@ RELOPT_OTHER_MEMBER_REL
Definition: pathnodes.h:856
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:69
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
forboth
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:518
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:479
PointerGetDatum
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:327
DatumGetPointer
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:317
InvalidOid
#define InvalidOid
Definition: postgres_ext.h:35
Oid
unsigned int Oid
Definition: postgres_ext.h:30
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
get_plan_rowmark
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition: preptlist.c:503
IS_TRUE
@ IS_TRUE
Definition: primnodes.h:1981
IS_FALSE
@ IS_FALSE
Definition: primnodes.h:1981
OR_EXPR
@ OR_EXPR
Definition: primnodes.h:948
root
tree ctl root
Definition: radixtree.h:1857
find_childrel_parents
Relids find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
Definition: relnode.c:1509
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:3446
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
BitmapAndPath::bitmapquals
List * bitmapquals
Definition: pathnodes.h:1934
BitmapHeapPath::bitmapqual
Path * bitmapqual
Definition: pathnodes.h:1922
BitmapOrPath::bitmapquals
List * bitmapquals
Definition: pathnodes.h:1947
BoolExpr::boolop
BoolExprType boolop
Definition: primnodes.h:956
BoolExpr::args
List * args
Definition: primnodes.h:957
BooleanTest::booltesttype
BoolTestType booltesttype
Definition: primnodes.h:1988
BooleanTest::arg
Expr * arg
Definition: primnodes.h:1987
EquivalenceClass::ec_opfamilies
List * ec_opfamilies
Definition: pathnodes.h:1450
FuncExpr::funcid
Oid funcid
Definition: primnodes.h:767
FuncExpr::args
List * args
Definition: primnodes.h:785
IndexClauseSet::nonempty
bool nonempty
Definition: indxpath.c:55
IndexClauseSet::indexclauses
List * indexclauses[INDEX_MAX_KEYS]
Definition: indxpath.c:57
IndexClause::indexcol
AttrNumber indexcol
Definition: pathnodes.h:1898
IndexClause::indexcols
List * indexcols
Definition: pathnodes.h:1899
IndexClause::indexquals
List * indexquals
Definition: pathnodes.h:1896
IndexClause::rinfo
struct RestrictInfo * rinfo
Definition: pathnodes.h:1895
IndexOptInfo::indpred
List * indpred
Definition: pathnodes.h:1200
IndexPath::indexclauses
List * indexclauses
Definition: pathnodes.h:1848
IndexPath::path
Path path
Definition: pathnodes.h:1846
IndexPath::indexselectivity
Selectivity indexselectivity
Definition: pathnodes.h:1853
IndexPath::indexinfo
IndexOptInfo * indexinfo
Definition: pathnodes.h:1847
List
Definition: pg_list.h:54
Node
Definition: nodes.h:135
NullTest::arg
Expr * arg
Definition: primnodes.h:1963
OpExpr::opno
Oid opno
Definition: primnodes.h:835
OpExpr::args
List * args
Definition: primnodes.h:853
PathClauseUsage::quals
List * quals
Definition: indxpath.c:64
PathClauseUsage::preds
List * preds
Definition: indxpath.c:65
PathClauseUsage::clauseids
Bitmapset * clauseids
Definition: indxpath.c:66
PathClauseUsage::unclassifiable
bool unclassifiable
Definition: indxpath.c:67
PathClauseUsage::path
Path * path
Definition: indxpath.c:63
PathKey::pk_cmptype
CompareType pk_cmptype
Definition: pathnodes.h:1606
PathKey::pk_nulls_first
bool pk_nulls_first
Definition: pathnodes.h:1607
PathKey::pk_opfamily
Oid pk_opfamily
Definition: pathnodes.h:1605
PathTarget::exprs
List * exprs
Definition: pathnodes.h:1669
Path::pathkeys
List * pathkeys
Definition: pathnodes.h:1802
Path::pathtype
NodeTag pathtype
Definition: pathnodes.h:1762
Path::parallel_workers
int parallel_workers
Definition: pathnodes.h:1793
Path::total_cost
Cost total_cost
Definition: pathnodes.h:1799
RelOptInfo::baserestrictinfo
List * baserestrictinfo
Definition: pathnodes.h:1012
RelOptInfo::joininfo
List * joininfo
Definition: pathnodes.h:1018
RelOptInfo::relids
Relids relids
Definition: pathnodes.h:898
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition: pathnodes.h:920
RelOptInfo::relid
Index relid
Definition: pathnodes.h:945
RelOptInfo::consider_parallel
bool consider_parallel
Definition: pathnodes.h:914
RelOptInfo::lateral_relids
Relids lateral_relids
Definition: pathnodes.h:940
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition: pathnodes.h:892
RelOptInfo::indexlist
List * indexlist
Definition: pathnodes.h:971
RelOptInfo::nulling_relids
Relids nulling_relids
Definition: pathnodes.h:965
RelOptInfo::rows
Cardinality rows
Definition: pathnodes.h:904
RestrictInfo::is_pushed_down
bool is_pushed_down
Definition: pathnodes.h:2703
RestrictInfo::security_level
Index security_level
Definition: pathnodes.h:2722
RestrictInfo::required_relids
Relids required_relids
Definition: pathnodes.h:2731
RestrictInfo::outer_relids
Relids outer_relids
Definition: pathnodes.h:2737
RestrictInfo::incompatible_relids
Relids incompatible_relids
Definition: pathnodes.h:2734
RestrictInfo::clause
Expr * clause
Definition: pathnodes.h:2700
RestrictInfo::has_clone
bool has_clone
Definition: pathnodes.h:2712
RowCompareExpr::cmptype
CompareType cmptype
Definition: primnodes.h:1473
SpecialJoinInfo::syn_lefthand
Relids syn_lefthand
Definition: pathnodes.h:3032
SpecialJoinInfo::semi_rhs_exprs
List * semi_rhs_exprs
Definition: pathnodes.h:3045
SpecialJoinInfo::jointype
JoinType jointype
Definition: pathnodes.h:3034
SpecialJoinInfo::syn_righthand
Relids syn_righthand
Definition: pathnodes.h:3033
SupportRequestIndexCondition::index
struct IndexOptInfo * index
Definition: supportnodes.h:232
SupportRequestIndexCondition::root
struct PlannerInfo * root
Definition: supportnodes.h:228
Var
Definition: primnodes.h:262
ec_member_matches_arg
Definition: indxpath.c:72
ec_member_matches_arg::index
IndexOptInfo * index
Definition: indxpath.c:73
ec_member_matches_arg::indexcol
int indexcol
Definition: indxpath.c:74
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