PostgreSQL Source Code git master
Loading...
Searching...
No Matches
indxpath.c
Go to the documentation of this file.
1/*-------------------------------------------------------------------------
2 *
3 * indxpath.c
4 * Routines to determine which indexes are usable for scanning a
5 * given relation, and create Paths accordingly.
6 *
7 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
9 *
10 *
11 * IDENTIFICATION
12 * src/backend/optimizer/path/indxpath.c
13 *
14 *-------------------------------------------------------------------------
15 */
16#include "postgres.h"
17
18#include "access/stratnum.h"
19#include "access/sysattr.h"
20#include "access/transam.h"
21#include "catalog/pg_am.h"
22#include "catalog/pg_amop.h"
23#include "catalog/pg_operator.h"
24#include "catalog/pg_opfamily.h"
25#include "catalog/pg_type.h"
26#include "nodes/makefuncs.h"
27#include "nodes/nodeFuncs.h"
28#include "nodes/supportnodes.h"
29#include "optimizer/cost.h"
30#include "optimizer/optimizer.h"
31#include "optimizer/pathnode.h"
32#include "optimizer/paths.h"
33#include "optimizer/placeholder.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 = palloc_array(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 = palloc_array(PathClauseUsage *, npaths);
1856 clauselist = NIL;
1857 npaths = 0;
1858 foreach(l, paths)
1859 {
1860 Path *ipath = (Path *) lfirst(l);
1861
1862 pathinfo = classify_index_clause_usage(ipath, &clauselist);
1863
1864 /* If it's unclassifiable, treat it as distinct from all others */
1865 if (pathinfo->unclassifiable)
1866 {
1867 pathinfoarray[npaths++] = pathinfo;
1868 continue;
1869 }
1870
1871 for (i = 0; i < npaths; i++)
1872 {
1873 if (!pathinfoarray[i]->unclassifiable &&
1874 bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
1875 break;
1876 }
1877 if (i < npaths)
1878 {
1879 /* duplicate clauseids, keep the cheaper one */
1880 Cost ncost;
1881 Cost ocost;
1882 Selectivity nselec;
1883 Selectivity oselec;
1884
1885 cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
1886 cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
1887 if (ncost < ocost)
1888 pathinfoarray[i] = pathinfo;
1889 }
1890 else
1891 {
1892 /* not duplicate clauseids, add to array */
1893 pathinfoarray[npaths++] = pathinfo;
1894 }
1895 }
1896
1897 /* If only one surviving path, we're done */
1898 if (npaths == 1)
1899 return pathinfoarray[0]->path;
1900
1901 /* Sort the surviving paths by index access cost */
1902 qsort(pathinfoarray, npaths, sizeof(PathClauseUsage *),
1903 path_usage_comparator);
1904
1905 /*
1906 * For each surviving index, consider it as an "AND group leader", and see
1907 * whether adding on any of the later indexes results in an AND path with
1908 * cheaper total cost than before. Then take the cheapest AND group.
1909 *
1910 * Note: paths that are either clauseless or unclassifiable will have
1911 * empty clauseids, so that they will not be rejected by the clauseids
1912 * filter here, nor will they cause later paths to be rejected by it.
1913 */
1914 for (i = 0; i < npaths; i++)
1915 {
1916 Cost costsofar;
1917 List *qualsofar;
1918 Bitmapset *clauseidsofar;
1919
1920 pathinfo = pathinfoarray[i];
1921 paths = list_make1(pathinfo->path);
1922 costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
1923 qualsofar = list_concat_copy(pathinfo->quals, pathinfo->preds);
1924 clauseidsofar = bms_copy(pathinfo->clauseids);
1925
1926 for (j = i + 1; j < npaths; j++)
1927 {
1928 Cost newcost;
1929
1930 pathinfo = pathinfoarray[j];
1931 /* Check for redundancy */
1932 if (bms_overlap(pathinfo->clauseids, clauseidsofar))
1933 continue; /* consider it redundant */
1934 if (pathinfo->preds)
1935 {
1936 bool redundant = false;
1937
1938 /* we check each predicate clause separately */
1939 foreach(l, pathinfo->preds)
1940 {
1941 Node *np = (Node *) lfirst(l);
1942
1943 if (predicate_implied_by(list_make1(np), qualsofar, false))
1944 {
1945 redundant = true;
1946 break; /* out of inner foreach loop */
1947 }
1948 }
1949 if (redundant)
1950 continue;
1951 }
1952 /* tentatively add new path to paths, so we can estimate cost */
1953 paths = lappend(paths, pathinfo->path);
1954 newcost = bitmap_and_cost_est(root, rel, paths);
1955 if (newcost < costsofar)
1956 {
1957 /* keep new path in paths, update subsidiary variables */
1958 costsofar = newcost;
1959 qualsofar = list_concat(qualsofar, pathinfo->quals);
1960 qualsofar = list_concat(qualsofar, pathinfo->preds);
1961 clauseidsofar = bms_add_members(clauseidsofar,
1962 pathinfo->clauseids);
1963 }
1964 else
1965 {
1966 /* reject new path, remove it from paths list */
1967 paths = list_truncate(paths, list_length(paths) - 1);
1968 }
1969 }
1970
1971 /* Keep the cheapest AND-group (or singleton) */
1972 if (i == 0 || costsofar < bestcost)
1973 {
1974 bestpaths = paths;
1975 bestcost = costsofar;
1976 }
1977
1978 /* some easy cleanup (we don't try real hard though) */
1979 list_free(qualsofar);
1980 }
1981
1982 if (list_length(bestpaths) == 1)
1983 return (Path *) linitial(bestpaths); /* no need for AND */
1984 return (Path *) create_bitmap_and_path(root, rel, bestpaths);
1985}
1986
1987/* qsort comparator to sort in increasing index access cost order */
1988static int
1989path_usage_comparator(const void *a, const void *b)
1990{
1991 PathClauseUsage *pa = *(PathClauseUsage *const *) a;
1992 PathClauseUsage *pb = *(PathClauseUsage *const *) b;
1993 Cost acost;
1994 Cost bcost;
1995 Selectivity aselec;
1996 Selectivity bselec;
1997
1998 cost_bitmap_tree_node(pa->path, &acost, &aselec);
1999 cost_bitmap_tree_node(pb->path, &bcost, &bselec);
2000
2001 /*
2002 * If costs are the same, sort by selectivity.
2003 */
2004 if (acost < bcost)
2005 return -1;
2006 if (acost > bcost)
2007 return 1;
2008
2009 if (aselec < bselec)
2010 return -1;
2011 if (aselec > bselec)
2012 return 1;
2013
2014 return 0;
2015}
2016
2017/*
2018 * Estimate the cost of actually executing a bitmap scan with a single
2019 * index path (which could be a BitmapAnd or BitmapOr node).
2020 */
2021static Cost
2022bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
2023{
2024 BitmapHeapPath bpath;
2025
2026 /* Set up a dummy BitmapHeapPath */
2027 bpath.path.type = T_BitmapHeapPath;
2028 bpath.path.pathtype = T_BitmapHeapScan;
2029 bpath.path.parent = rel;
2030 bpath.path.pathtarget = rel->reltarget;
2031 bpath.path.param_info = ipath->param_info;
2032 bpath.path.pathkeys = NIL;
2033 bpath.bitmapqual = ipath;
2034
2035 /*
2036 * Check the cost of temporary path without considering parallelism.
2037 * Parallel bitmap heap path will be considered at later stage.
2038 */
2039 bpath.path.parallel_workers = 0;
2040
2041 /* Now we can do cost_bitmap_heap_scan */
2042 cost_bitmap_heap_scan(&bpath.path, root, rel,
2043 bpath.path.param_info,
2044 ipath,
2045 get_loop_count(root, rel->relid,
2046 PATH_REQ_OUTER(ipath)));
2047
2048 return bpath.path.total_cost;
2049}
2050
2051/*
2052 * Estimate the cost of actually executing a BitmapAnd scan with the given
2053 * inputs.
2054 */
2055static Cost
2056bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
2057{
2058 BitmapAndPath *apath;
2059
2060 /*
2061 * Might as well build a real BitmapAndPath here, as the work is slightly
2062 * too complicated to be worth repeating just to save one palloc.
2063 */
2064 apath = create_bitmap_and_path(root, rel, paths);
2065
2066 return bitmap_scan_cost_est(root, rel, (Path *) apath);
2067}
2068
2069
2070/*
2071 * classify_index_clause_usage
2072 * Construct a PathClauseUsage struct describing the WHERE clauses and
2073 * index predicate clauses used by the given indexscan path.
2074 * We consider two clauses the same if they are equal().
2075 *
2076 * At some point we might want to migrate this info into the Path data
2077 * structure proper, but for the moment it's only needed within
2078 * choose_bitmap_and().
2079 *
2080 * *clauselist is used and expanded as needed to identify all the distinct
2081 * clauses seen across successive calls. Caller must initialize it to NIL
2082 * before first call of a set.
2083 */
2084static PathClauseUsage *
2085classify_index_clause_usage(Path *path, List **clauselist)
2086{
2087 PathClauseUsage *result;
2088 Bitmapset *clauseids;
2089 ListCell *lc;
2090
2091 result = palloc_object(PathClauseUsage);
2092 result->path = path;
2093
2094 /* Recursively find the quals and preds used by the path */
2095 result->quals = NIL;
2096 result->preds = NIL;
2097 find_indexpath_quals(path, &result->quals, &result->preds);
2098
2099 /*
2100 * Some machine-generated queries have outlandish numbers of qual clauses.
2101 * To avoid getting into O(N^2) behavior even in this preliminary
2102 * classification step, we want to limit the number of entries we can
2103 * accumulate in *clauselist. Treat any path with more than 100 quals +
2104 * preds as unclassifiable, which will cause calling code to consider it
2105 * distinct from all other paths.
2106 */
2107 if (list_length(result->quals) + list_length(result->preds) > 100)
2108 {
2109 result->clauseids = NULL;
2110 result->unclassifiable = true;
2111 return result;
2112 }
2113
2114 /* Build up a bitmapset representing the quals and preds */
2115 clauseids = NULL;
2116 foreach(lc, result->quals)
2117 {
2118 Node *node = (Node *) lfirst(lc);
2119
2120 clauseids = bms_add_member(clauseids,
2121 find_list_position(node, clauselist));
2122 }
2123 foreach(lc, result->preds)
2124 {
2125 Node *node = (Node *) lfirst(lc);
2126
2127 clauseids = bms_add_member(clauseids,
2128 find_list_position(node, clauselist));
2129 }
2130 result->clauseids = clauseids;
2131 result->unclassifiable = false;
2132
2133 return result;
2134}
2135
2136
2137/*
2138 * find_indexpath_quals
2139 *
2140 * Given the Path structure for a plain or bitmap indexscan, extract lists
2141 * of all the index clauses and index predicate conditions used in the Path.
2142 * These are appended to the initial contents of *quals and *preds (hence
2143 * caller should initialize those to NIL).
2144 *
2145 * Note we are not trying to produce an accurate representation of the AND/OR
2146 * semantics of the Path, but just find out all the base conditions used.
2147 *
2148 * The result lists contain pointers to the expressions used in the Path,
2149 * but all the list cells are freshly built, so it's safe to destructively
2150 * modify the lists (eg, by concat'ing with other lists).
2151 */
2152static void
2153find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
2154{
2155 if (IsA(bitmapqual, BitmapAndPath))
2156 {
2157 BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
2158 ListCell *l;
2159
2160 foreach(l, apath->bitmapquals)
2161 {
2162 find_indexpath_quals((Path *) lfirst(l), quals, preds);
2163 }
2164 }
2165 else if (IsA(bitmapqual, BitmapOrPath))
2166 {
2167 BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
2168 ListCell *l;
2169
2170 foreach(l, opath->bitmapquals)
2171 {
2172 find_indexpath_quals((Path *) lfirst(l), quals, preds);
2173 }
2174 }
2175 else if (IsA(bitmapqual, IndexPath))
2176 {
2177 IndexPath *ipath = (IndexPath *) bitmapqual;
2178 ListCell *l;
2179
2180 foreach(l, ipath->indexclauses)
2181 {
2182 IndexClause *iclause = (IndexClause *) lfirst(l);
2183
2184 *quals = lappend(*quals, iclause->rinfo->clause);
2185 }
2186 *preds = list_concat(*preds, ipath->indexinfo->indpred);
2187 }
2188 else
2189 elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
2190}
2191
2192
2193/*
2194 * find_list_position
2195 * Return the given node's position (counting from 0) in the given
2196 * list of nodes. If it's not equal() to any existing list member,
2197 * add it at the end, and return that position.
2198 */
2199static int
2200find_list_position(Node *node, List **nodelist)
2201{
2202 int i;
2203 ListCell *lc;
2204
2205 i = 0;
2206 foreach(lc, *nodelist)
2207 {
2208 Node *oldnode = (Node *) lfirst(lc);
2209
2210 if (equal(node, oldnode))
2211 return i;
2212 i++;
2213 }
2214
2215 *nodelist = lappend(*nodelist, node);
2216
2217 return i;
2218}
2219
2220
2221/*
2222 * check_index_only
2223 * Determine whether an index-only scan is possible for this index.
2224 */
2225static bool
2226check_index_only(RelOptInfo *rel, IndexOptInfo *index)
2227{
2228 bool result;
2229 Bitmapset *attrs_used = NULL;
2230 Bitmapset *index_canreturn_attrs = NULL;
2231 ListCell *lc;
2232 int i;
2233
2234 /* If we're not allowed to consider index-only scans, give up now */
2235 if ((rel->pgs_mask & PGS_CONSIDER_INDEXONLY) == 0)
2236 return false;
2237
2238 /*
2239 * Check that all needed attributes of the relation are available from the
2240 * index.
2241 */
2242
2243 /*
2244 * First, identify all the attributes needed for joins or final output.
2245 * Note: we must look at rel's targetlist, not the attr_needed data,
2246 * because attr_needed isn't computed for inheritance child rels.
2247 */
2248 pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
2249
2250 /*
2251 * Add all the attributes used by restriction clauses; but consider only
2252 * those clauses not implied by the index predicate, since ones that are
2253 * so implied don't need to be checked explicitly in the plan.
2254 *
2255 * Note: attributes used only in index quals would not be needed at
2256 * runtime either, if we are certain that the index is not lossy. However
2257 * it'd be complicated to account for that accurately, and it doesn't
2258 * matter in most cases, since we'd conclude that such attributes are
2259 * available from the index anyway.
2260 */
2261 foreach(lc, index->indrestrictinfo)
2262 {
2263 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2264
2265 pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
2266 }
2267
2268 /*
2269 * Construct a bitmapset of columns that the index can return back in an
2270 * index-only scan.
2271 */
2272 for (i = 0; i < index->ncolumns; i++)
2273 {
2274 int attno = index->indexkeys[i];
2275
2276 /*
2277 * For the moment, we just ignore index expressions. It might be nice
2278 * to do something with them, later.
2279 */
2280 if (attno == 0)
2281 continue;
2282
2283 if (index->canreturn[i])
2284 index_canreturn_attrs =
2285 bms_add_member(index_canreturn_attrs,
2286 attno - FirstLowInvalidHeapAttributeNumber);
2287 }
2288
2289 /* Do we have all the necessary attributes? */
2290 result = bms_is_subset(attrs_used, index_canreturn_attrs);
2291
2292 bms_free(attrs_used);
2293 bms_free(index_canreturn_attrs);
2294
2295 return result;
2296}
2297
2298/*
2299 * get_loop_count
2300 * Choose the loop count estimate to use for costing a parameterized path
2301 * with the given set of outer relids.
2302 *
2303 * Since we produce parameterized paths before we've begun to generate join
2304 * relations, it's impossible to predict exactly how many times a parameterized
2305 * path will be iterated; we don't know the size of the relation that will be
2306 * on the outside of the nestloop. However, we should try to account for
2307 * multiple iterations somehow in costing the path. The heuristic embodied
2308 * here is to use the rowcount of the smallest other base relation needed in
2309 * the join clauses used by the path. (We could alternatively consider the
2310 * largest one, but that seems too optimistic.) This is of course the right
2311 * answer for single-other-relation cases, and it seems like a reasonable
2312 * zero-order approximation for multiway-join cases.
2313 *
2314 * In addition, we check to see if the other side of each join clause is on
2315 * the inside of some semijoin that the current relation is on the outside of.
2316 * If so, the only way that a parameterized path could be used is if the
2317 * semijoin RHS has been unique-ified, so we should use the number of unique
2318 * RHS rows rather than using the relation's raw rowcount.
2319 *
2320 * Note: for this to work, allpaths.c must establish all baserel size
2321 * estimates before it begins to compute paths, or at least before it
2322 * calls create_index_paths().
2323 */
2324static double
2325get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
2326{
2327 double result;
2328 int outer_relid;
2329
2330 /* For a non-parameterized path, just return 1.0 quickly */
2331 if (outer_relids == NULL)
2332 return 1.0;
2333
2334 result = 0.0;
2335 outer_relid = -1;
2336 while ((outer_relid = bms_next_member(outer_relids, outer_relid)) >= 0)
2337 {
2338 RelOptInfo *outer_rel;
2339 double rowcount;
2340
2341 /* Paranoia: ignore bogus relid indexes */
2342 if (outer_relid >= root->simple_rel_array_size)
2343 continue;
2344 outer_rel = root->simple_rel_array[outer_relid];
2345 if (outer_rel == NULL)
2346 continue;
2347 Assert(outer_rel->relid == outer_relid); /* sanity check on array */
2348
2349 /* Other relation could be proven empty, if so ignore */
2350 if (IS_DUMMY_REL(outer_rel))
2351 continue;
2352
2353 /* Otherwise, rel's rows estimate should be valid by now */
2354 Assert(outer_rel->rows > 0);
2355
2356 /* Check to see if rel is on the inside of any semijoins */
2357 rowcount = adjust_rowcount_for_semijoins(root,
2358 cur_relid,
2359 outer_relid,
2360 outer_rel->rows);
2361
2362 /* Remember smallest row count estimate among the outer rels */
2363 if (result == 0.0 || result > rowcount)
2364 result = rowcount;
2365 }
2366 /* Return 1.0 if we found no valid relations (shouldn't happen) */
2367 return (result > 0.0) ? result : 1.0;
2368}
2369
2370/*
2371 * Check to see if outer_relid is on the inside of any semijoin that cur_relid
2372 * is on the outside of. If so, replace rowcount with the estimated number of
2373 * unique rows from the semijoin RHS (assuming that's smaller, which it might
2374 * not be). The estimate is crude but it's the best we can do at this stage
2375 * of the proceedings.
2376 */
2377static double
2378adjust_rowcount_for_semijoins(PlannerInfo *root,
2379 Index cur_relid,
2380 Index outer_relid,
2381 double rowcount)
2382{
2383 ListCell *lc;
2384
2385 foreach(lc, root->join_info_list)
2386 {
2387 SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
2388
2389 if (sjinfo->jointype == JOIN_SEMI &&
2390 bms_is_member(cur_relid, sjinfo->syn_lefthand) &&
2391 bms_is_member(outer_relid, sjinfo->syn_righthand))
2392 {
2393 /* Estimate number of unique-ified rows */
2394 double nraw;
2395 double nunique;
2396
2397 nraw = approximate_joinrel_size(root, sjinfo->syn_righthand);
2398 nunique = estimate_num_groups(root,
2399 sjinfo->semi_rhs_exprs,
2400 nraw,
2401 NULL,
2402 NULL);
2403 if (rowcount > nunique)
2404 rowcount = nunique;
2405 }
2406 }
2407 return rowcount;
2408}
2409
2410/*
2411 * Make an approximate estimate of the size of a joinrel.
2412 *
2413 * We don't have enough info at this point to get a good estimate, so we
2414 * just multiply the base relation sizes together. Fortunately, this is
2415 * the right answer anyway for the most common case with a single relation
2416 * on the RHS of a semijoin. Also, estimate_num_groups() has only a weak
2417 * dependency on its input_rows argument (it basically uses it as a clamp).
2418 * So we might be able to get a fairly decent end result even with a severe
2419 * overestimate of the RHS's raw size.
2420 */
2421static double
2422approximate_joinrel_size(PlannerInfo *root, Relids relids)
2423{
2424 double rowcount = 1.0;
2425 int relid;
2426
2427 relid = -1;
2428 while ((relid = bms_next_member(relids, relid)) >= 0)
2429 {
2430 RelOptInfo *rel;
2431
2432 /* Paranoia: ignore bogus relid indexes */
2433 if (relid >= root->simple_rel_array_size)
2434 continue;
2435 rel = root->simple_rel_array[relid];
2436 if (rel == NULL)
2437 continue;
2438 Assert(rel->relid == relid); /* sanity check on array */
2439
2440 /* Relation could be proven empty, if so ignore */
2441 if (IS_DUMMY_REL(rel))
2442 continue;
2443
2444 /* Otherwise, rel's rows estimate should be valid by now */
2445 Assert(rel->rows > 0);
2446
2447 /* Accumulate product */
2448 rowcount *= rel->rows;
2449 }
2450 return rowcount;
2451}
2452
2453
2454/****************************************************************************
2455 * ---- ROUTINES TO CHECK QUERY CLAUSES ----
2456 ****************************************************************************/
2457
2458/*
2459 * match_restriction_clauses_to_index
2460 * Identify restriction clauses for the rel that match the index.
2461 * Matching clauses are added to *clauseset.
2462 */
2463static void
2464match_restriction_clauses_to_index(PlannerInfo *root,
2465 IndexOptInfo *index,
2466 IndexClauseSet *clauseset)
2467{
2468 /* We can ignore clauses that are implied by the index predicate */
2469 match_clauses_to_index(root, index->indrestrictinfo, index, clauseset);
2470}
2471
2472/*
2473 * match_join_clauses_to_index
2474 * Identify join clauses for the rel that match the index.
2475 * Matching clauses are added to *clauseset.
2476 * Also, add any potentially usable join OR clauses to *joinorclauses.
2477 * They also might be processed by match_clause_to_index() as a whole.
2478 */
2479static void
2480match_join_clauses_to_index(PlannerInfo *root,
2481 RelOptInfo *rel, IndexOptInfo *index,
2482 IndexClauseSet *clauseset,
2483 List **joinorclauses)
2484{
2485 ListCell *lc;
2486
2487 /* Scan the rel's join clauses */
2488 foreach(lc, rel->joininfo)
2489 {
2490 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2491
2492 /* Check if clause can be moved to this rel */
2493 if (!join_clause_is_movable_to(rinfo, rel))
2494 continue;
2495
2496 /*
2497 * Potentially usable, so see if it matches the index or is an OR. Use
2498 * list_append_unique_ptr() here to avoid possible duplicates when
2499 * processing the same clauses with different indexes.
2500 */
2501 if (restriction_is_or_clause(rinfo))
2502 *joinorclauses = list_append_unique_ptr(*joinorclauses, rinfo);
2503
2504 match_clause_to_index(root, rinfo, index, clauseset);
2505 }
2506}
2507
2508/*
2509 * match_eclass_clauses_to_index
2510 * Identify EquivalenceClass join clauses for the rel that match the index.
2511 * Matching clauses are added to *clauseset.
2512 */
2513static void
2514match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index,
2515 IndexClauseSet *clauseset)
2516{
2517 int indexcol;
2518
2519 /* No work if rel is not in any such ECs */
2520 if (!index->rel->has_eclass_joins)
2521 return;
2522
2523 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2524 {
2525 ec_member_matches_arg arg;
2526 List *clauses;
2527
2528 /* Generate clauses, skipping any that join to lateral_referencers */
2529 arg.index = index;
2530 arg.indexcol = indexcol;
2531 clauses = generate_implied_equalities_for_column(root,
2532 index->rel,
2533 ec_member_matches_indexcol,
2534 &arg,
2535 index->rel->lateral_referencers);
2536
2537 /*
2538 * We have to check whether the results actually do match the index,
2539 * since for non-btree indexes the EC's equality operators might not
2540 * be in the index opclass (cf ec_member_matches_indexcol).
2541 */
2542 match_clauses_to_index(root, clauses, index, clauseset);
2543 }
2544}
2545
2546/*
2547 * match_clauses_to_index
2548 * Perform match_clause_to_index() for each clause in a list.
2549 * Matching clauses are added to *clauseset.
2550 */
2551static void
2552match_clauses_to_index(PlannerInfo *root,
2553 List *clauses,
2554 IndexOptInfo *index,
2555 IndexClauseSet *clauseset)
2556{
2557 ListCell *lc;
2558
2559 foreach(lc, clauses)
2560 {
2561 RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
2562
2563 match_clause_to_index(root, rinfo, index, clauseset);
2564 }
2565}
2566
2567/*
2568 * match_clause_to_index
2569 * Test whether a qual clause can be used with an index.
2570 *
2571 * If the clause is usable, add an IndexClause entry for it to the appropriate
2572 * list in *clauseset. (*clauseset must be initialized to zeroes before first
2573 * call.)
2574 *
2575 * Note: in some circumstances we may find the same RestrictInfos coming from
2576 * multiple places. Defend against redundant outputs by refusing to add a
2577 * clause twice (pointer equality should be a good enough check for this).
2578 *
2579 * Note: it's possible that a badly-defined index could have multiple matching
2580 * columns. We always select the first match if so; this avoids scenarios
2581 * wherein we get an inflated idea of the index's selectivity by using the
2582 * same clause multiple times with different index columns.
2583 */
2584static void
2585match_clause_to_index(PlannerInfo *root,
2586 RestrictInfo *rinfo,
2587 IndexOptInfo *index,
2588 IndexClauseSet *clauseset)
2589{
2590 int indexcol;
2591
2592 /*
2593 * Never match pseudoconstants to indexes. (Normally a match could not
2594 * happen anyway, since a pseudoconstant clause couldn't contain a Var,
2595 * but what if someone builds an expression index on a constant? It's not
2596 * totally unreasonable to do so with a partial index, either.)
2597 */
2598 if (rinfo->pseudoconstant)
2599 return;
2600
2601 /*
2602 * If clause can't be used as an indexqual because it must wait till after
2603 * some lower-security-level restriction clause, reject it.
2604 */
2605 if (!restriction_is_securely_promotable(rinfo, index->rel))
2606 return;
2607
2608 /* OK, check each index key column for a match */
2609 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2610 {
2611 IndexClause *iclause;
2612 ListCell *lc;
2613
2614 /* Ignore duplicates */
2615 foreach(lc, clauseset->indexclauses[indexcol])
2616 {
2617 iclause = (IndexClause *) lfirst(lc);
2618
2619 if (iclause->rinfo == rinfo)
2620 return;
2621 }
2622
2623 /* OK, try to match the clause to the index column */
2624 iclause = match_clause_to_indexcol(root,
2625 rinfo,
2626 indexcol,
2627 index);
2628 if (iclause)
2629 {
2630 /* Success, so record it */
2631 clauseset->indexclauses[indexcol] =
2632 lappend(clauseset->indexclauses[indexcol], iclause);
2633 clauseset->nonempty = true;
2634 return;
2635 }
2636 }
2637}
2638
2639/*
2640 * match_clause_to_indexcol()
2641 * Determine whether a restriction clause matches a column of an index,
2642 * and if so, build an IndexClause node describing the details.
2643 *
2644 * To match an index normally, an operator clause:
2645 *
2646 * (1) must be in the form (indexkey op const) or (const op indexkey);
2647 * and
2648 * (2) must contain an operator which is in the index's operator family
2649 * for this column; and
2650 * (3) must match the collation of the index, if collation is relevant.
2651 *
2652 * Our definition of "const" is exceedingly liberal: we allow anything that
2653 * doesn't involve a volatile function or a Var of the index's relation.
2654 * In particular, Vars belonging to other relations of the query are
2655 * accepted here, since a clause of that form can be used in a
2656 * parameterized indexscan. It's the responsibility of higher code levels
2657 * to manage restriction and join clauses appropriately.
2658 *
2659 * Note: we do need to check for Vars of the index's relation on the
2660 * "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
2661 * are not processable by a parameterized indexscan on a.f1, whereas
2662 * something like (a.f1 OP (b.f2 OP c.f3)) is.
2663 *
2664 * Presently, the executor can only deal with indexquals that have the
2665 * indexkey on the left, so we can only use clauses that have the indexkey
2666 * on the right if we can commute the clause to put the key on the left.
2667 * We handle that by generating an IndexClause with the correctly-commuted
2668 * opclause as a derived indexqual.
2669 *
2670 * If the index has a collation, the clause must have the same collation.
2671 * For collation-less indexes, we assume it doesn't matter; this is
2672 * necessary for cases like "hstore ? text", wherein hstore's operators
2673 * don't care about collation but the clause will get marked with a
2674 * collation anyway because of the text argument. (This logic is
2675 * embodied in the macro IndexCollMatchesExprColl.)
2676 *
2677 * It is also possible to match RowCompareExpr clauses to indexes (but
2678 * currently, only btree indexes handle this).
2679 *
2680 * It is also possible to match ScalarArrayOpExpr clauses to indexes, when
2681 * the clause is of the form "indexkey op ANY (arrayconst)".
2682 *
2683 * It is also possible to match a list of OR clauses if it might be
2684 * transformed into a single ScalarArrayOpExpr clause. On success,
2685 * the returning index clause will contain a transformed clause.
2686 *
2687 * For boolean indexes, it is also possible to match the clause directly
2688 * to the indexkey; or perhaps the clause is (NOT indexkey).
2689 *
2690 * And, last but not least, some operators and functions can be processed
2691 * to derive (typically lossy) indexquals from a clause that isn't in
2692 * itself indexable. If we see that any operand of an OpExpr or FuncExpr
2693 * matches the index key, and the function has a planner support function
2694 * attached to it, we'll invoke the support function to see if such an
2695 * indexqual can be built.
2696 *
2697 * 'rinfo' is the clause to be tested (as a RestrictInfo node).
2698 * 'indexcol' is a column number of 'index' (counting from 0).
2699 * 'index' is the index of interest.
2700 *
2701 * Returns an IndexClause if the clause can be used with this index key,
2702 * or NULL if not.
2703 *
2704 * NOTE: This routine always returns NULL if the clause is an AND clause.
2705 * Higher-level routines deal with OR and AND clauses. OR clause can be
2706 * matched as a whole by match_orclause_to_indexcol() though.
2707 */
2708static IndexClause *
2709match_clause_to_indexcol(PlannerInfo *root,
2710 RestrictInfo *rinfo,
2711 int indexcol,
2712 IndexOptInfo *index)
2713{
2714 IndexClause *iclause;
2715 Expr *clause = rinfo->clause;
2716 Oid opfamily;
2717
2718 Assert(indexcol < index->nkeycolumns);
2719
2720 /*
2721 * Historically this code has coped with NULL clauses. That's probably
2722 * not possible anymore, but we might as well continue to cope.
2723 */
2724 if (clause == NULL)
2725 return NULL;
2726
2727 /* First check for boolean-index cases. */
2728 opfamily = index->opfamily[indexcol];
2729 if (IsBooleanOpfamily(opfamily))
2730 {
2731 iclause = match_boolean_index_clause(root, rinfo, indexcol, index);
2732 if (iclause)
2733 return iclause;
2734 }
2735
2736 /*
2737 * Clause must be an opclause, funcclause, ScalarArrayOpExpr,
2738 * RowCompareExpr, or OR-clause that could be converted to SAOP. Or, if
2739 * the index supports it, we can handle IS NULL/NOT NULL clauses.
2740 */
2741 if (IsA(clause, OpExpr))
2742 {
2743 return match_opclause_to_indexcol(root, rinfo, indexcol, index);
2744 }
2745 else if (IsA(clause, FuncExpr))
2746 {
2747 return match_funcclause_to_indexcol(root, rinfo, indexcol, index);
2748 }
2749 else if (IsA(clause, ScalarArrayOpExpr))
2750 {
2751 return match_saopclause_to_indexcol(root, rinfo, indexcol, index);
2752 }
2753 else if (IsA(clause, RowCompareExpr))
2754 {
2755 return match_rowcompare_to_indexcol(root, rinfo, indexcol, index);
2756 }
2757 else if (restriction_is_or_clause(rinfo))
2758 {
2759 return match_orclause_to_indexcol(root, rinfo, indexcol, index);
2760 }
2761 else if (index->amsearchnulls && IsA(clause, NullTest))
2762 {
2763 NullTest *nt = (NullTest *) clause;
2764
2765 if (!nt->argisrow &&
2766 match_index_to_operand((Node *) nt->arg, indexcol, index))
2767 {
2768 iclause = makeNode(IndexClause);
2769 iclause->rinfo = rinfo;
2770 iclause->indexquals = list_make1(rinfo);
2771 iclause->lossy = false;
2772 iclause->indexcol = indexcol;
2773 iclause->indexcols = NIL;
2774 return iclause;
2775 }
2776 }
2777
2778 return NULL;
2779}
2780
2781/*
2782 * IsBooleanOpfamily
2783 * Detect whether an opfamily supports boolean equality as an operator.
2784 *
2785 * If the opfamily OID is in the range of built-in objects, we can rely
2786 * on hard-wired knowledge of which built-in opfamilies support this.
2787 * For extension opfamilies, there's no choice but to do a catcache lookup.
2788 */
2789static bool
2790IsBooleanOpfamily(Oid opfamily)
2791{
2792 if (opfamily < FirstNormalObjectId)
2793 return IsBuiltinBooleanOpfamily(opfamily);
2794 else
2795 return op_in_opfamily(BooleanEqualOperator, opfamily);
2796}
2797
2798/*
2799 * match_boolean_index_clause
2800 * Recognize restriction clauses that can be matched to a boolean index.
2801 *
2802 * The idea here is that, for an index on a boolean column that supports the
2803 * BooleanEqualOperator, we can transform a plain reference to the indexkey
2804 * into "indexkey = true", or "NOT indexkey" into "indexkey = false", etc,
2805 * so as to make the expression indexable using the index's "=" operator.
2806 * Since Postgres 8.1, we must do this because constant simplification does
2807 * the reverse transformation; without this code there'd be no way to use
2808 * such an index at all.
2809 *
2810 * This should be called only when IsBooleanOpfamily() recognizes the
2811 * index's operator family. We check to see if the clause matches the
2812 * index's key, and if so, build a suitable IndexClause.
2813 */
2814static IndexClause *
2815match_boolean_index_clause(PlannerInfo *root,
2816 RestrictInfo *rinfo,
2817 int indexcol,
2818 IndexOptInfo *index)
2819{
2820 Node *clause = (Node *) rinfo->clause;
2821 Expr *op = NULL;
2822
2823 /* Direct match? */
2824 if (match_index_to_operand(clause, indexcol, index))
2825 {
2826 /* convert to indexkey = TRUE */
2827 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2828 (Expr *) clause,
2829 (Expr *) makeBoolConst(true, false),
2830 InvalidOid, InvalidOid);
2831 }
2832 /* NOT clause? */
2833 else if (is_notclause(clause))
2834 {
2835 Node *arg = (Node *) get_notclausearg((Expr *) clause);
2836
2837 if (match_index_to_operand(arg, indexcol, index))
2838 {
2839 /* convert to indexkey = FALSE */
2840 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2841 (Expr *) arg,
2842 (Expr *) makeBoolConst(false, false),
2843 InvalidOid, InvalidOid);
2844 }
2845 }
2846
2847 /*
2848 * Since we only consider clauses at top level of WHERE, we can convert
2849 * indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
2850 * different meaning for NULL isn't important.
2851 */
2852 else if (clause && IsA(clause, BooleanTest))
2853 {
2854 BooleanTest *btest = (BooleanTest *) clause;
2855 Node *arg = (Node *) btest->arg;
2856
2857 if (btest->booltesttype == IS_TRUE &&
2858 match_index_to_operand(arg, indexcol, index))
2859 {
2860 /* convert to indexkey = TRUE */
2861 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2862 (Expr *) arg,
2863 (Expr *) makeBoolConst(true, false),
2864 InvalidOid, InvalidOid);
2865 }
2866 else if (btest->booltesttype == IS_FALSE &&
2867 match_index_to_operand(arg, indexcol, index))
2868 {
2869 /* convert to indexkey = FALSE */
2870 op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2871 (Expr *) arg,
2872 (Expr *) makeBoolConst(false, false),
2873 InvalidOid, InvalidOid);
2874 }
2875 }
2876
2877 /*
2878 * If we successfully made an operator clause from the given qual, we must
2879 * wrap it in an IndexClause. It's not lossy.
2880 */
2881 if (op)
2882 {
2883 IndexClause *iclause = makeNode(IndexClause);
2884
2885 iclause->rinfo = rinfo;
2886 iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
2887 iclause->lossy = false;
2888 iclause->indexcol = indexcol;
2889 iclause->indexcols = NIL;
2890 return iclause;
2891 }
2892
2893 return NULL;
2894}
2895
2896/*
2897 * match_opclause_to_indexcol()
2898 * Handles the OpExpr case for match_clause_to_indexcol(),
2899 * which see for comments.
2900 */
2901static IndexClause *
2902match_opclause_to_indexcol(PlannerInfo *root,
2903 RestrictInfo *rinfo,
2904 int indexcol,
2905 IndexOptInfo *index)
2906{
2907 IndexClause *iclause;
2908 OpExpr *clause = (OpExpr *) rinfo->clause;
2909 Node *leftop,
2910 *rightop;
2911 Oid expr_op;
2912 Oid expr_coll;
2913 Index index_relid;
2914 Oid opfamily;
2915 Oid idxcollation;
2916
2917 /*
2918 * Only binary operators need apply. (In theory, a planner support
2919 * function could do something with a unary operator, but it seems
2920 * unlikely to be worth the cycles to check.)
2921 */
2922 if (list_length(clause->args) != 2)
2923 return NULL;
2924
2925 leftop = (Node *) linitial(clause->args);
2926 rightop = (Node *) lsecond(clause->args);
2927 expr_op = clause->opno;
2928 expr_coll = clause->inputcollid;
2929
2930 index_relid = index->rel->relid;
2931 opfamily = index->opfamily[indexcol];
2932 idxcollation = index->indexcollations[indexcol];
2933
2934 /*
2935 * Check for clauses of the form: (indexkey operator constant) or
2936 * (constant operator indexkey). See match_clause_to_indexcol's notes
2937 * about const-ness.
2938 *
2939 * Note that we don't ask the support function about clauses that don't
2940 * have one of these forms. Again, in principle it might be possible to
2941 * do something, but it seems unlikely to be worth the cycles to check.
2942 */
2943 if (match_index_to_operand(leftop, indexcol, index) &&
2944 !bms_is_member(index_relid, rinfo->right_relids) &&
2945 !contain_volatile_functions(rightop))
2946 {
2947 if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
2948 op_in_opfamily(expr_op, opfamily))
2949 {
2950 iclause = makeNode(IndexClause);
2951 iclause->rinfo = rinfo;
2952 iclause->indexquals = list_make1(rinfo);
2953 iclause->lossy = false;
2954 iclause->indexcol = indexcol;
2955 iclause->indexcols = NIL;
2956 return iclause;
2957 }
2958
2959 /*
2960 * If we didn't find a member of the index's opfamily, try the support
2961 * function for the operator's underlying function.
2962 */
2963 set_opfuncid(clause); /* make sure we have opfuncid */
2964 return get_index_clause_from_support(root,
2965 rinfo,
2966 clause->opfuncid,
2967 0, /* indexarg on left */
2968 indexcol,
2969 index);
2970 }
2971
2972 if (match_index_to_operand(rightop, indexcol, index) &&
2973 !bms_is_member(index_relid, rinfo->left_relids) &&
2974 !contain_volatile_functions(leftop))
2975 {
2976 if (IndexCollMatchesExprColl(idxcollation, expr_coll))
2977 {
2978 Oid comm_op = get_commutator(expr_op);
2979
2980 if (OidIsValid(comm_op) &&
2981 op_in_opfamily(comm_op, opfamily))
2982 {
2983 RestrictInfo *commrinfo;
2984
2985 /* Build a commuted OpExpr and RestrictInfo */
2986 commrinfo = commute_restrictinfo(rinfo, comm_op);
2987
2988 /* Make an IndexClause showing that as a derived qual */
2989 iclause = makeNode(IndexClause);
2990 iclause->rinfo = rinfo;
2991 iclause->indexquals = list_make1(commrinfo);
2992 iclause->lossy = false;
2993 iclause->indexcol = indexcol;
2994 iclause->indexcols = NIL;
2995 return iclause;
2996 }
2997 }
2998
2999 /*
3000 * If we didn't find a member of the index's opfamily, try the support
3001 * function for the operator's underlying function.
3002 */
3003 set_opfuncid(clause); /* make sure we have opfuncid */
3004 return get_index_clause_from_support(root,
3005 rinfo,
3006 clause->opfuncid,
3007 1, /* indexarg on right */
3008 indexcol,
3009 index);
3010 }
3011
3012 return NULL;
3013}
3014
3015/*
3016 * match_funcclause_to_indexcol()
3017 * Handles the FuncExpr case for match_clause_to_indexcol(),
3018 * which see for comments.
3019 */
3020static IndexClause *
3021match_funcclause_to_indexcol(PlannerInfo *root,
3022 RestrictInfo *rinfo,
3023 int indexcol,
3024 IndexOptInfo *index)
3025{
3026 FuncExpr *clause = (FuncExpr *) rinfo->clause;
3027 int indexarg;
3028 ListCell *lc;
3029
3030 /*
3031 * We have no built-in intelligence about function clauses, but if there's
3032 * a planner support function, it might be able to do something. But, to
3033 * cut down on wasted planning cycles, only call the support function if
3034 * at least one argument matches the target index column.
3035 *
3036 * Note that we don't insist on the other arguments being pseudoconstants;
3037 * the support function has to check that. This is to allow cases where
3038 * only some of the other arguments need to be included in the indexqual.
3039 */
3040 indexarg = 0;
3041 foreach(lc, clause->args)
3042 {
3043 Node *op = (Node *) lfirst(lc);
3044
3045 if (match_index_to_operand(op, indexcol, index))
3046 {
3047 return get_index_clause_from_support(root,
3048 rinfo,
3049 clause->funcid,
3050 indexarg,
3051 indexcol,
3052 index);
3053 }
3054
3055 indexarg++;
3056 }
3057
3058 return NULL;
3059}
3060
3061/*
3062 * get_index_clause_from_support()
3063 * If the function has a planner support function, try to construct
3064 * an IndexClause using indexquals created by the support function.
3065 */
3066static IndexClause *
3067get_index_clause_from_support(PlannerInfo *root,
3068 RestrictInfo *rinfo,
3069 Oid funcid,
3070 int indexarg,
3071 int indexcol,
3072 IndexOptInfo *index)
3073{
3074 Oid prosupport = get_func_support(funcid);
3075 SupportRequestIndexCondition req;
3076 List *sresult;
3077
3078 if (!OidIsValid(prosupport))
3079 return NULL;
3080
3081 req.type = T_SupportRequestIndexCondition;
3082 req.root = root;
3083 req.funcid = funcid;
3084 req.node = (Node *) rinfo->clause;
3085 req.indexarg = indexarg;
3086 req.index = index;
3087 req.indexcol = indexcol;
3088 req.opfamily = index->opfamily[indexcol];
3089 req.indexcollation = index->indexcollations[indexcol];
3090
3091 req.lossy = true; /* default assumption */
3092
3093 sresult = (List *)
3094 DatumGetPointer(OidFunctionCall1(prosupport,
3095 PointerGetDatum(&req)));
3096
3097 if (sresult != NIL)
3098 {
3099 IndexClause *iclause = makeNode(IndexClause);
3100 List *indexquals = NIL;
3101 ListCell *lc;
3102
3103 /*
3104 * The support function API says it should just give back bare
3105 * clauses, so here we must wrap each one in a RestrictInfo.
3106 */
3107 foreach(lc, sresult)
3108 {
3109 Expr *clause = (Expr *) lfirst(lc);
3110
3111 indexquals = lappend(indexquals,
3112 make_simple_restrictinfo(root, clause));
3113 }
3114
3115 iclause->rinfo = rinfo;
3116 iclause->indexquals = indexquals;
3117 iclause->lossy = req.lossy;
3118 iclause->indexcol = indexcol;
3119 iclause->indexcols = NIL;
3120
3121 return iclause;
3122 }
3123
3124 return NULL;
3125}
3126
3127/*
3128 * match_saopclause_to_indexcol()
3129 * Handles the ScalarArrayOpExpr case for match_clause_to_indexcol(),
3130 * which see for comments.
3131 */
3132static IndexClause *
3133match_saopclause_to_indexcol(PlannerInfo *root,
3134 RestrictInfo *rinfo,
3135 int indexcol,
3136 IndexOptInfo *index)
3137{
3138 ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
3139 Node *leftop,
3140 *rightop;
3141 Relids right_relids;
3142 Oid expr_op;
3143 Oid expr_coll;
3144 Index index_relid;
3145 Oid opfamily;
3146 Oid idxcollation;
3147
3148 /* We only accept ANY clauses, not ALL */
3149 if (!saop->useOr)
3150 return NULL;
3151 leftop = (Node *) linitial(saop->args);
3152 rightop = (Node *) lsecond(saop->args);
3153 right_relids = pull_varnos(root, rightop);
3154 expr_op = saop->opno;
3155 expr_coll = saop->inputcollid;
3156
3157 index_relid = index->rel->relid;
3158 opfamily = index->opfamily[indexcol];
3159 idxcollation = index->indexcollations[indexcol];
3160
3161 /*
3162 * We must have indexkey on the left and a pseudo-constant array argument.
3163 */
3164 if (match_index_to_operand(leftop, indexcol, index) &&
3165 !bms_is_member(index_relid, right_relids) &&
3166 !contain_volatile_functions(rightop))
3167 {
3168 if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
3169 op_in_opfamily(expr_op, opfamily))
3170 {
3171 IndexClause *iclause = makeNode(IndexClause);
3172
3173 iclause->rinfo = rinfo;
3174 iclause->indexquals = list_make1(rinfo);
3175 iclause->lossy = false;
3176 iclause->indexcol = indexcol;
3177 iclause->indexcols = NIL;
3178 return iclause;
3179 }
3180
3181 /*
3182 * We do not currently ask support functions about ScalarArrayOpExprs,
3183 * though in principle we could.
3184 */
3185 }
3186
3187 return NULL;
3188}
3189
3190/*
3191 * match_rowcompare_to_indexcol()
3192 * Handles the RowCompareExpr case for match_clause_to_indexcol(),
3193 * which see for comments.
3194 *
3195 * In this routine we check whether the first column of the row comparison
3196 * matches the target index column. This is sufficient to guarantee that some
3197 * index condition can be constructed from the RowCompareExpr --- the rest
3198 * is handled by expand_indexqual_rowcompare().
3199 */
3200static IndexClause *
3201match_rowcompare_to_indexcol(PlannerInfo *root,
3202 RestrictInfo *rinfo,
3203 int indexcol,
3204 IndexOptInfo *index)
3205{
3206 RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3207 Index index_relid;
3208 Oid opfamily;
3209 Oid idxcollation;
3210 Node *leftop,
3211 *rightop;
3212 bool var_on_left;
3213 Oid expr_op;
3214 Oid expr_coll;
3215
3216 /* Forget it if we're not dealing with a btree index */
3217 if (index->relam != BTREE_AM_OID)
3218 return NULL;
3219
3220 index_relid = index->rel->relid;
3221 opfamily = index->opfamily[indexcol];
3222 idxcollation = index->indexcollations[indexcol];
3223
3224 /*
3225 * We could do the matching on the basis of insisting that the opfamily
3226 * shown in the RowCompareExpr be the same as the index column's opfamily,
3227 * but that could fail in the presence of reverse-sort opfamilies: it'd be
3228 * a matter of chance whether RowCompareExpr had picked the forward or
3229 * reverse-sort family. So look only at the operator, and match if it is
3230 * a member of the index's opfamily (after commutation, if the indexkey is
3231 * on the right). We'll worry later about whether any additional
3232 * operators are matchable to the index.
3233 */
3234 leftop = (Node *) linitial(clause->largs);
3235 rightop = (Node *) linitial(clause->rargs);
3236 expr_op = linitial_oid(clause->opnos);
3237 expr_coll = linitial_oid(clause->inputcollids);
3238
3239 /* Collations must match, if relevant */
3240 if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3241 return NULL;
3242
3243 /*
3244 * These syntactic tests are the same as in match_opclause_to_indexcol()
3245 */
3246 if (match_index_to_operand(leftop, indexcol, index) &&
3247 !bms_is_member(index_relid, pull_varnos(root, rightop)) &&
3248 !contain_volatile_functions(rightop))
3249 {
3250 /* OK, indexkey is on left */
3251 var_on_left = true;
3252 }
3253 else if (match_index_to_operand(rightop, indexcol, index) &&
3254 !bms_is_member(index_relid, pull_varnos(root, leftop)) &&
3255 !contain_volatile_functions(leftop))
3256 {
3257 /* indexkey is on right, so commute the operator */
3258 expr_op = get_commutator(expr_op);
3259 if (expr_op == InvalidOid)
3260 return NULL;
3261 var_on_left = false;
3262 }
3263 else
3264 return NULL;
3265
3266 /* We're good if the operator is the right type of opfamily member */
3267 switch (get_op_opfamily_strategy(expr_op, opfamily))
3268 {
3269 case BTLessStrategyNumber:
3270 case BTLessEqualStrategyNumber:
3271 case BTGreaterEqualStrategyNumber:
3272 case BTGreaterStrategyNumber:
3273 return expand_indexqual_rowcompare(root,
3274 rinfo,
3275 indexcol,
3276 index,
3277 expr_op,
3278 var_on_left);
3279 }
3280
3281 return NULL;
3282}
3283
3284/*
3285 * match_orclause_to_indexcol()
3286 * Handles the OR-expr case for match_clause_to_indexcol() in the case
3287 * when it could be transformed to ScalarArrayOpExpr.
3288 *
3289 * In this routine, we attempt to transform a list of OR-clause args into a
3290 * single SAOP expression matching the target index column. On success,
3291 * return an IndexClause containing the transformed expression.
3292 * Return NULL if the transformation fails.
3293 */
3294static IndexClause *
3295match_orclause_to_indexcol(PlannerInfo *root,
3296 RestrictInfo *rinfo,
3297 int indexcol,
3298 IndexOptInfo *index)
3299{
3300 BoolExpr *orclause = (BoolExpr *) rinfo->orclause;
3301 List *consts = NIL;
3302 Node *indexExpr = NULL;
3303 Oid matchOpno = InvalidOid;
3304 Oid consttype = InvalidOid;
3305 Oid arraytype = InvalidOid;
3306 Oid inputcollid = InvalidOid;
3307 bool firstTime = true;
3308 bool haveNonConst = false;
3309 Index indexRelid = index->rel->relid;
3310 ScalarArrayOpExpr *saopexpr;
3311 IndexClause *iclause;
3312 ListCell *lc;
3313
3314 /* Forget it if index doesn't support SAOP clauses */
3315 if (!index->amsearcharray)
3316 return NULL;
3317
3318 /*
3319 * Try to convert a list of OR-clauses to a single SAOP expression. Each
3320 * OR entry must be in the form: (indexkey operator constant) or (constant
3321 * operator indexkey). Operators of all the entries must match. On
3322 * discovery of anything unsupported, we give up by breaking out of the
3323 * loop immediately and returning NULL.
3324 */
3325 foreach(lc, orclause->args)
3326 {
3327 RestrictInfo *subRinfo = (RestrictInfo *) lfirst(lc);
3328 OpExpr *subClause;
3329 Oid opno;
3330 Node *leftop,
3331 *rightop;
3332 Node *constExpr;
3333
3334 /* If it's not a RestrictInfo (i.e. it's a sub-AND), we can't use it */
3335 if (!IsA(subRinfo, RestrictInfo))
3336 break;
3337
3338 /* Only operator clauses can match */
3339 if (!IsA(subRinfo->clause, OpExpr))
3340 break;
3341
3342 subClause = (OpExpr *) subRinfo->clause;
3343 opno = subClause->opno;
3344
3345 /* Only binary operators can match */
3346 if (list_length(subClause->args) != 2)
3347 break;
3348
3349 /*
3350 * Check for clauses of the form: (indexkey operator constant) or
3351 * (constant operator indexkey). These tests should agree with
3352 * match_opclause_to_indexcol.
3353 */
3354 leftop = (Node *) linitial(subClause->args);
3355 rightop = (Node *) lsecond(subClause->args);
3356 if (match_index_to_operand(leftop, indexcol, index) &&
3357 !bms_is_member(indexRelid, subRinfo->right_relids) &&
3358 !contain_volatile_functions(rightop))
3359 {
3360 indexExpr = leftop;
3361 constExpr = rightop;
3362 }
3363 else if (match_index_to_operand(rightop, indexcol, index) &&
3364 !bms_is_member(indexRelid, subRinfo->left_relids) &&
3365 !contain_volatile_functions(leftop))
3366 {
3367 opno = get_commutator(opno);
3368 if (!OidIsValid(opno))
3369 {
3370 /* commutator doesn't exist, we can't reverse the order */
3371 break;
3372 }
3373 indexExpr = rightop;
3374 constExpr = leftop;
3375 }
3376 else
3377 {
3378 break;
3379 }
3380
3381 /*
3382 * Save information about the operator, type, and collation for the
3383 * first matching qual. Then, check that subsequent quals match the
3384 * first.
3385 */
3386 if (firstTime)
3387 {
3388 matchOpno = opno;
3389 consttype = exprType(constExpr);
3390 arraytype = get_array_type(consttype);
3391 inputcollid = subClause->inputcollid;
3392
3393 /*
3394 * Check that the operator is presented in the opfamily and that
3395 * the expression collation matches the index collation. Also,
3396 * there must be an array type to construct an array later.
3397 */
3398 if (!IndexCollMatchesExprColl(index->indexcollations[indexcol],
3399 inputcollid) ||
3400 !op_in_opfamily(matchOpno, index->opfamily[indexcol]) ||
3401 !OidIsValid(arraytype))
3402 break;
3403
3404 /*
3405 * Disallow if either type is RECORD, mainly because we can't be
3406 * positive that all the RHS expressions are the same record type.
3407 */
3408 if (consttype == RECORDOID || exprType(indexExpr) == RECORDOID)
3409 break;
3410
3411 firstTime = false;
3412 }
3413 else
3414 {
3415 if (matchOpno != opno ||
3416 inputcollid != subClause->inputcollid ||
3417 consttype != exprType(constExpr))
3418 break;
3419 }
3420
3421 /*
3422 * The righthand inputs don't necessarily have to be plain Consts, but
3423 * make_SAOP_expr needs to know if any are not.
3424 */
3425 if (!IsA(constExpr, Const))
3426 haveNonConst = true;
3427
3428 consts = lappend(consts, constExpr);
3429 }
3430
3431 /*
3432 * Handle failed conversion from breaking out of the loop because of an
3433 * unsupported qual. Also check that we have an indexExpr, just in case
3434 * the OR list was somehow empty (it shouldn't be). Return NULL to
3435 * indicate the conversion failed.
3436 */
3437 if (lc != NULL || indexExpr == NULL)
3438 {
3439 list_free(consts); /* might as well */
3440 return NULL;
3441 }
3442
3443 /*
3444 * Build the new SAOP node. We use the indexExpr from the last OR arm;
3445 * since all the arms passed match_index_to_operand, it shouldn't matter
3446 * which one we use. But using "inputcollid" twice is a bit of a cheat:
3447 * we might end up with an array Const node that is labeled with a
3448 * collation despite its elements being of a noncollatable type. But
3449 * nothing is likely to complain about that, so we don't bother being more
3450 * accurate.
3451 */
3452 saopexpr = make_SAOP_expr(matchOpno, indexExpr, consttype, inputcollid,
3453 inputcollid, consts, haveNonConst);
3454 Assert(saopexpr != NULL);
3455
3456 /*
3457 * Finally, build an IndexClause based on the SAOP node. It's not lossy.
3458 */
3459 iclause = makeNode(IndexClause);
3460 iclause->rinfo = rinfo;
3461 iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3462 (Expr *) saopexpr));
3463 iclause->lossy = false;
3464 iclause->indexcol = indexcol;
3465 iclause->indexcols = NIL;
3466 return iclause;
3467}
3468
3469/*
3470 * expand_indexqual_rowcompare --- expand a single indexqual condition
3471 * that is a RowCompareExpr
3472 *
3473 * It's already known that the first column of the row comparison matches
3474 * the specified column of the index. We can use additional columns of the
3475 * row comparison as index qualifications, so long as they match the index
3476 * in the "same direction", ie, the indexkeys are all on the same side of the
3477 * clause and the operators are all the same-type members of the opfamilies.
3478 *
3479 * If all the columns of the RowCompareExpr match in this way, we just use it
3480 * as-is, except for possibly commuting it to put the indexkeys on the left.
3481 *
3482 * Otherwise, we build a shortened RowCompareExpr (if more than one
3483 * column matches) or a simple OpExpr (if the first-column match is all
3484 * there is). In these cases the modified clause is always "<=" or ">="
3485 * even when the original was "<" or ">" --- this is necessary to match all
3486 * the rows that could match the original. (We are building a lossy version
3487 * of the row comparison when we do this, so we set lossy = true.)
3488 *
3489 * Note: this is really just the last half of match_rowcompare_to_indexcol,
3490 * but we split it out for comprehensibility.
3491 */
3492static IndexClause *
3493expand_indexqual_rowcompare(PlannerInfo *root,
3494 RestrictInfo *rinfo,
3495 int indexcol,
3496 IndexOptInfo *index,
3497 Oid expr_op,
3498 bool var_on_left)
3499{
3500 IndexClause *iclause = makeNode(IndexClause);
3501 RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3502 int op_strategy;
3503 Oid op_lefttype;
3504 Oid op_righttype;
3505 int matching_cols;
3506 List *expr_ops;
3507 List *opfamilies;
3508 List *lefttypes;
3509 List *righttypes;
3510 List *new_ops;
3511 List *var_args;
3512 List *non_var_args;
3513
3514 iclause->rinfo = rinfo;
3515 iclause->indexcol = indexcol;
3516
3517 if (var_on_left)
3518 {
3519 var_args = clause->largs;
3520 non_var_args = clause->rargs;
3521 }
3522 else
3523 {
3524 var_args = clause->rargs;
3525 non_var_args = clause->largs;
3526 }
3527
3528 get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
3529 &op_strategy,
3530 &op_lefttype,
3531 &op_righttype);
3532
3533 /* Initialize returned list of which index columns are used */
3534 iclause->indexcols = list_make1_int(indexcol);
3535
3536 /* Build lists of ops, opfamilies and operator datatypes in case needed */
3537 expr_ops = list_make1_oid(expr_op);
3538 opfamilies = list_make1_oid(index->opfamily[indexcol]);
3539 lefttypes = list_make1_oid(op_lefttype);
3540 righttypes = list_make1_oid(op_righttype);
3541
3542 /*
3543 * See how many of the remaining columns match some index column in the
3544 * same way. As in match_clause_to_indexcol(), the "other" side of any
3545 * potential index condition is OK as long as it doesn't use Vars from the
3546 * indexed relation.
3547 */
3548 matching_cols = 1;
3549
3550 while (matching_cols < list_length(var_args))
3551 {
3552 Node *varop = (Node *) list_nth(var_args, matching_cols);
3553 Node *constop = (Node *) list_nth(non_var_args, matching_cols);
3554 int i;
3555
3556 expr_op = list_nth_oid(clause->opnos, matching_cols);
3557 if (!var_on_left)
3558 {
3559 /* indexkey is on right, so commute the operator */
3560 expr_op = get_commutator(expr_op);
3561 if (expr_op == InvalidOid)
3562 break; /* operator is not usable */
3563 }
3564 if (bms_is_member(index->rel->relid, pull_varnos(root, constop)))
3565 break; /* no good, Var on wrong side */
3566 if (contain_volatile_functions(constop))
3567 break; /* no good, volatile comparison value */
3568
3569 /*
3570 * The Var side can match any key column of the index.
3571 */
3572 for (i = 0; i < index->nkeycolumns; i++)
3573 {
3574 if (match_index_to_operand(varop, i, index) &&
3575 get_op_opfamily_strategy(expr_op,
3576 index->opfamily[i]) == op_strategy &&
3577 IndexCollMatchesExprColl(index->indexcollations[i],
3578 list_nth_oid(clause->inputcollids,
3579 matching_cols)))
3580 break;
3581 }
3582 if (i >= index->nkeycolumns)
3583 break; /* no match found */
3584
3585 /* Add column number to returned list */
3586 iclause->indexcols = lappend_int(iclause->indexcols, i);
3587
3588 /* Add operator info to lists */
3589 get_op_opfamily_properties(expr_op, index->opfamily[i], false,
3590 &op_strategy,
3591 &op_lefttype,
3592 &op_righttype);
3593 expr_ops = lappend_oid(expr_ops, expr_op);
3594 opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
3595 lefttypes = lappend_oid(lefttypes, op_lefttype);
3596 righttypes = lappend_oid(righttypes, op_righttype);
3597
3598 /* This column matches, keep scanning */
3599 matching_cols++;
3600 }
3601
3602 /* Result is non-lossy if all columns are usable as index quals */
3603 iclause->lossy = (matching_cols != list_length(clause->opnos));
3604
3605 /*
3606 * We can use rinfo->clause as-is if we have var on left and it's all
3607 * usable as index quals.
3608 */
3609 if (var_on_left && !iclause->lossy)
3610 iclause->indexquals = list_make1(rinfo);
3611 else
3612 {
3613 /*
3614 * We have to generate a modified rowcompare (possibly just one
3615 * OpExpr). The painful part of this is changing < to <= or > to >=,
3616 * so deal with that first.
3617 */
3618 if (!iclause->lossy)
3619 {
3620 /* very easy, just use the commuted operators */
3621 new_ops = expr_ops;
3622 }
3623 else if (op_strategy == BTLessEqualStrategyNumber ||
3624 op_strategy == BTGreaterEqualStrategyNumber)
3625 {
3626 /* easy, just use the same (possibly commuted) operators */
3627 new_ops = list_truncate(expr_ops, matching_cols);
3628 }
3629 else
3630 {
3631 ListCell *opfamilies_cell;
3632 ListCell *lefttypes_cell;
3633 ListCell *righttypes_cell;
3634
3635 if (op_strategy == BTLessStrategyNumber)
3636 op_strategy = BTLessEqualStrategyNumber;
3637 else if (op_strategy == BTGreaterStrategyNumber)
3638 op_strategy = BTGreaterEqualStrategyNumber;
3639 else
3640 elog(ERROR, "unexpected strategy number %d", op_strategy);
3641 new_ops = NIL;
3642 forthree(opfamilies_cell, opfamilies,
3643 lefttypes_cell, lefttypes,
3644 righttypes_cell, righttypes)
3645 {
3646 Oid opfam = lfirst_oid(opfamilies_cell);
3647 Oid lefttype = lfirst_oid(lefttypes_cell);
3648 Oid righttype = lfirst_oid(righttypes_cell);
3649
3650 expr_op = get_opfamily_member(opfam, lefttype, righttype,
3651 op_strategy);
3652 if (!OidIsValid(expr_op)) /* should not happen */
3653 elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3654 op_strategy, lefttype, righttype, opfam);
3655 new_ops = lappend_oid(new_ops, expr_op);
3656 }
3657 }
3658
3659 /* If we have more than one matching col, create a subset rowcompare */
3660 if (matching_cols > 1)
3661 {
3662 RowCompareExpr *rc = makeNode(RowCompareExpr);
3663
3664 rc->cmptype = (CompareType) op_strategy;
3665 rc->opnos = new_ops;
3666 rc->opfamilies = list_copy_head(clause->opfamilies,
3667 matching_cols);
3668 rc->inputcollids = list_copy_head(clause->inputcollids,
3669 matching_cols);
3670 rc->largs = list_copy_head(var_args, matching_cols);
3671 rc->rargs = list_copy_head(non_var_args, matching_cols);
3672 iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3673 (Expr *) rc));
3674 }
3675 else
3676 {
3677 Expr *op;
3678
3679 /* We don't report an index column list in this case */
3680 iclause->indexcols = NIL;
3681
3682 op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
3683 copyObject(linitial(var_args)),
3684 copyObject(linitial(non_var_args)),
3685 InvalidOid,
3686 linitial_oid(clause->inputcollids));
3687 iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
3688 }
3689 }
3690
3691 return iclause;
3692}
3693
3694
3695/****************************************************************************
3696 * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3697 ****************************************************************************/
3698
3699/*
3700 * match_pathkeys_to_index
3701 * For the given 'index' and 'pathkeys', output a list of suitable ORDER
3702 * BY expressions, each of the form "indexedcol operator pseudoconstant",
3703 * along with an integer list of the index column numbers (zero based)
3704 * that each clause would be used with.
3705 *
3706 * This attempts to find an ORDER BY and index column number for all items in
3707 * the pathkey list, however, if we're unable to match any given pathkey to an
3708 * index column, we return just the ones matched by the function so far. This
3709 * allows callers who are interested in partial matches to get them. Callers
3710 * can determine a partial match vs a full match by checking the outputted
3711 * list lengths. A full match will have one item in the output lists for each
3712 * item in the given 'pathkeys' list.
3713 */
3714static void
3715match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3716 List **orderby_clauses_p,
3717 List **clause_columns_p)
3718{
3719 ListCell *lc1;
3720
3721 *orderby_clauses_p = NIL; /* set default results */
3722 *clause_columns_p = NIL;
3723
3724 /* Only indexes with the amcanorderbyop property are interesting here */
3725 if (!index->amcanorderbyop)
3726 return;
3727
3728 foreach(lc1, pathkeys)
3729 {
3730 PathKey *pathkey = (PathKey *) lfirst(lc1);
3731 bool found = false;
3732 EquivalenceMemberIterator it;
3733 EquivalenceMember *member;
3734
3735
3736 /* Pathkey must request default sort order for the target opfamily */
3737 if (pathkey->pk_cmptype != COMPARE_LT || pathkey->pk_nulls_first)
3738 return;
3739
3740 /* If eclass is volatile, no hope of using an indexscan */
3741 if (pathkey->pk_eclass->ec_has_volatile)
3742 return;
3743
3744 /*
3745 * Try to match eclass member expression(s) to index. Note that child
3746 * EC members are considered, but only when they belong to the target
3747 * relation. (Unlike regular members, the same expression could be a
3748 * child member of more than one EC. Therefore, the same index could
3749 * be considered to match more than one pathkey list, which is OK
3750 * here. See also get_eclass_for_sort_expr.)
3751 */
3752 setup_eclass_member_iterator(&it, pathkey->pk_eclass,
3753 index->rel->relids);
3754 while ((member = eclass_member_iterator_next(&it)) != NULL)
3755 {
3756 int indexcol;
3757
3758 /* No possibility of match if it references other relations */
3759 if (!bms_equal(member->em_relids, index->rel->relids))
3760 continue;
3761
3762 /*
3763 * We allow any column of the index to match each pathkey; they
3764 * don't have to match left-to-right as you might expect. This is
3765 * correct for GiST, and it doesn't matter for SP-GiST because
3766 * that doesn't handle multiple columns anyway, and no other
3767 * existing AMs support amcanorderbyop. We might need different
3768 * logic in future for other implementations.
3769 */
3770 for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3771 {
3772 Expr *expr;
3773
3774 expr = match_clause_to_ordering_op(index,
3775 indexcol,
3776 member->em_expr,
3777 pathkey->pk_opfamily);
3778 if (expr)
3779 {
3780 *orderby_clauses_p = lappend(*orderby_clauses_p, expr);
3781 *clause_columns_p = lappend_int(*clause_columns_p, indexcol);
3782 found = true;
3783 break;
3784 }
3785 }
3786
3787 if (found) /* don't want to look at remaining members */
3788 break;
3789 }
3790
3791 /*
3792 * Return the matches found so far when this pathkey couldn't be
3793 * matched to the index.
3794 */
3795 if (!found)
3796 return;
3797 }
3798}
3799
3800/*
3801 * match_clause_to_ordering_op
3802 * Determines whether an ordering operator expression matches an
3803 * index column.
3804 *
3805 * This is similar to, but simpler than, match_clause_to_indexcol.
3806 * We only care about simple OpExpr cases. The input is a bare
3807 * expression that is being ordered by, which must be of the form
3808 * (indexkey op const) or (const op indexkey) where op is an ordering
3809 * operator for the column's opfamily.
3810 *
3811 * 'index' is the index of interest.
3812 * 'indexcol' is a column number of 'index' (counting from 0).
3813 * 'clause' is the ordering expression to be tested.
3814 * 'pk_opfamily' is the btree opfamily describing the required sort order.
3815 *
3816 * Note that we currently do not consider the collation of the ordering
3817 * operator's result. In practical cases the result type will be numeric
3818 * and thus have no collation, and it's not very clear what to match to
3819 * if it did have a collation. The index's collation should match the
3820 * ordering operator's input collation, not its result.
3821 *
3822 * If successful, return 'clause' as-is if the indexkey is on the left,
3823 * otherwise a commuted copy of 'clause'. If no match, return NULL.
3824 */
3825static Expr *
3826match_clause_to_ordering_op(IndexOptInfo *index,
3827 int indexcol,
3828 Expr *clause,
3829 Oid pk_opfamily)
3830{
3831 Oid opfamily;
3832 Oid idxcollation;
3833 Node *leftop,
3834 *rightop;
3835 Oid expr_op;
3836 Oid expr_coll;
3837 Oid sortfamily;
3838 bool commuted;
3839
3840 Assert(indexcol < index->nkeycolumns);
3841
3842 opfamily = index->opfamily[indexcol];
3843 idxcollation = index->indexcollations[indexcol];
3844
3845 /*
3846 * Clause must be a binary opclause.
3847 */
3848 if (!is_opclause(clause))
3849 return NULL;
3850 leftop = get_leftop(clause);
3851 rightop = get_rightop(clause);
3852 if (!leftop || !rightop)
3853 return NULL;
3854 expr_op = ((OpExpr *) clause)->opno;
3855 expr_coll = ((OpExpr *) clause)->inputcollid;
3856
3857 /*
3858 * We can forget the whole thing right away if wrong collation.
3859 */
3860 if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3861 return NULL;
3862
3863 /*
3864 * Check for clauses of the form: (indexkey operator constant) or
3865 * (constant operator indexkey).
3866 */
3867 if (match_index_to_operand(leftop, indexcol, index) &&
3868 !contain_var_clause(rightop) &&
3869 !contain_volatile_functions(rightop))
3870 {
3871 commuted = false;
3872 }
3873 else if (match_index_to_operand(rightop, indexcol, index) &&
3874 !contain_var_clause(leftop) &&
3875 !contain_volatile_functions(leftop))
3876 {
3877 /* Might match, but we need a commuted operator */
3878 expr_op = get_commutator(expr_op);
3879 if (expr_op == InvalidOid)
3880 return NULL;
3881 commuted = true;
3882 }
3883 else
3884 return NULL;
3885
3886 /*
3887 * Is the (commuted) operator an ordering operator for the opfamily? And
3888 * if so, does it yield the right sorting semantics?
3889 */
3890 sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3891 if (sortfamily != pk_opfamily)
3892 return NULL;
3893
3894 /* We have a match. Return clause or a commuted version thereof. */
3895 if (commuted)
3896 {
3897 OpExpr *newclause = makeNode(OpExpr);
3898
3899 /* flat-copy all the fields of clause */
3900 memcpy(newclause, clause, sizeof(OpExpr));
3901
3902 /* commute it */
3903 newclause->opno = expr_op;
3904 newclause->opfuncid = InvalidOid;
3905 newclause->args = list_make2(rightop, leftop);
3906
3907 clause = (Expr *) newclause;
3908 }
3909
3910 return clause;
3911}
3912
3913
3914/****************************************************************************
3915 * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3916 ****************************************************************************/
3917
3918/*
3919 * check_index_predicates
3920 * Set the predicate-derived IndexOptInfo fields for each index
3921 * of the specified relation.
3922 *
3923 * predOK is set true if the index is partial and its predicate is satisfied
3924 * for this query, ie the query's WHERE clauses imply the predicate.
3925 *
3926 * indrestrictinfo is set to the relation's baserestrictinfo list less any
3927 * conditions that are implied by the index's predicate. (Obviously, for a
3928 * non-partial index, this is the same as baserestrictinfo.) Such conditions
3929 * can be dropped from the plan when using the index, in certain cases.
3930 *
3931 * At one time it was possible for this to get re-run after adding more
3932 * restrictions to the rel, thus possibly letting us prove more indexes OK.
3933 * That doesn't happen any more (at least not in the core code's usage),
3934 * but this code still supports it in case extensions want to mess with the
3935 * baserestrictinfo list. We assume that adding more restrictions can't make
3936 * an index not predOK. We must recompute indrestrictinfo each time, though,
3937 * to make sure any newly-added restrictions get into it if needed.
3938 */
3939void
3940check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3941{
3942 List *clauselist;
3943 bool have_partial;
3944 bool is_target_rel;
3945 Relids otherrels;
3946 ListCell *lc;
3947
3948 /* Indexes are available only on base or "other" member relations. */
3949 Assert(IS_SIMPLE_REL(rel));
3950
3951 /*
3952 * Initialize the indrestrictinfo lists to be identical to
3953 * baserestrictinfo, and check whether there are any partial indexes. If
3954 * not, this is all we need to do.
3955 */
3956 have_partial = false;
3957 foreach(lc, rel->indexlist)
3958 {
3959 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3960
3961 index->indrestrictinfo = rel->baserestrictinfo;
3962 if (index->indpred)
3963 have_partial = true;
3964 }
3965 if (!have_partial)
3966 return;
3967
3968 /*
3969 * Construct a list of clauses that we can assume true for the purpose of
3970 * proving the index(es) usable. Restriction clauses for the rel are
3971 * always usable, and so are any join clauses that are "movable to" this
3972 * rel. Also, we can consider any EC-derivable join clauses (which must
3973 * be "movable to" this rel, by definition).
3974 */
3975 clauselist = list_copy(rel->baserestrictinfo);
3976
3977 /* Scan the rel's join clauses */
3978 foreach(lc, rel->joininfo)
3979 {
3980 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3981
3982 /* Check if clause can be moved to this rel */
3983 if (!join_clause_is_movable_to(rinfo, rel))
3984 continue;
3985
3986 clauselist = lappend(clauselist, rinfo);
3987 }
3988
3989 /*
3990 * Add on any equivalence-derivable join clauses. Computing the correct
3991 * relid sets for generate_join_implied_equalities is slightly tricky
3992 * because the rel could be a child rel rather than a true baserel, and in
3993 * that case we must subtract its parents' relid(s) from all_query_rels.
3994 * Additionally, we mustn't consider clauses that are only computable
3995 * after outer joins that can null the rel.
3996 */
3997 if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3998 otherrels = bms_difference(root->all_query_rels,
3999 find_childrel_parents(root, rel));
4000 else
4001 otherrels = bms_difference(root->all_query_rels, rel->relids);
4002 otherrels = bms_del_members(otherrels, rel->nulling_relids);
4003
4004 if (!bms_is_empty(otherrels))
4005 clauselist =
4006 list_concat(clauselist,
4007 generate_join_implied_equalities(root,
4008 bms_union(rel->relids,
4009 otherrels),
4010 otherrels,
4011 rel,
4012 NULL));
4013
4014 /*
4015 * Normally we remove quals that are implied by a partial index's
4016 * predicate from indrestrictinfo, indicating that they need not be
4017 * checked explicitly by an indexscan plan using this index. However, if
4018 * the rel is a target relation of UPDATE/DELETE/MERGE/SELECT FOR UPDATE,
4019 * we cannot remove such quals from the plan, because they need to be in
4020 * the plan so that they will be properly rechecked by EvalPlanQual
4021 * testing. Some day we might want to remove such quals from the main
4022 * plan anyway and pass them through to EvalPlanQual via a side channel;
4023 * but for now, we just don't remove implied quals at all for target
4024 * relations.
4025 */
4026 is_target_rel = (bms_is_member(rel->relid, root->all_result_relids) ||
4027 get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
4028
4029 /*
4030 * Now try to prove each index predicate true, and compute the
4031 * indrestrictinfo lists for partial indexes. Note that we compute the
4032 * indrestrictinfo list even for non-predOK indexes; this might seem
4033 * wasteful, but we may be able to use such indexes in OR clauses, cf
4034 * generate_bitmap_or_paths().
4035 */
4036 foreach(lc, rel->indexlist)
4037 {
4038 IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
4039 ListCell *lcr;
4040
4041 if (index->indpred == NIL)
4042 continue; /* ignore non-partial indexes here */
4043
4044 if (!index->predOK) /* don't repeat work if already proven OK */
4045 index->predOK = predicate_implied_by(index->indpred, clauselist,
4046 false);
4047
4048 /* If rel is an update target, leave indrestrictinfo as set above */
4049 if (is_target_rel)
4050 continue;
4051
4052 /*
4053 * If index is !amoptionalkey, also leave indrestrictinfo as set
4054 * above. Otherwise we risk removing all quals for the first index
4055 * key and then not being able to generate an indexscan at all. It
4056 * would be better to be more selective, but we've not yet identified
4057 * which if any of the quals match the first index key.
4058 */
4059 if (!index->amoptionalkey)
4060 continue;
4061
4062 /* Else compute indrestrictinfo as the non-implied quals */
4063 index->indrestrictinfo = NIL;
4064 foreach(lcr, rel->baserestrictinfo)
4065 {
4066 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
4067
4068 /* predicate_implied_by() assumes first arg is immutable */
4069 if (contain_mutable_functions((Node *) rinfo->clause) ||
4070 !predicate_implied_by(list_make1(rinfo->clause),
4071 index->indpred, false))
4072 index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
4073 }
4074 }
4075}
4076
4077/****************************************************************************
4078 * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
4079 ****************************************************************************/
4080
4081/*
4082 * ec_member_matches_indexcol
4083 * Test whether an EquivalenceClass member matches an index column.
4084 *
4085 * This is a callback for use by generate_implied_equalities_for_column.
4086 */
4087static bool
4088ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
4089 EquivalenceClass *ec, EquivalenceMember *em,
4090 void *arg)
4091{
4092 IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
4093 int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
4094 Oid curFamily;
4095 Oid curCollation;
4096
4097 Assert(indexcol < index->nkeycolumns);
4098
4099 curFamily = index->opfamily[indexcol];
4100 curCollation = index->indexcollations[indexcol];
4101
4102 /*
4103 * If it's a btree index, we can reject it if its opfamily isn't
4104 * compatible with the EC, since no clause generated from the EC could be
4105 * used with the index. For non-btree indexes, we can't easily tell
4106 * whether clauses generated from the EC could be used with the index, so
4107 * don't check the opfamily. This might mean we return "true" for a
4108 * useless EC, so we have to recheck the results of
4109 * generate_implied_equalities_for_column; see
4110 * match_eclass_clauses_to_index.
4111 */
4112 if (index->relam == BTREE_AM_OID &&
4113 !list_member_oid(ec->ec_opfamilies, curFamily))
4114 return false;
4115
4116 /* We insist on collation match for all index types, though */
4117 if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
4118 return false;
4119
4120 return match_index_to_operand((Node *) em->em_expr, indexcol, index);
4121}
4122
4123/*
4124 * relation_has_unique_index_for
4125 * Determine whether the relation provably has at most one row satisfying
4126 * a set of equality conditions, because the conditions constrain all
4127 * columns of some unique index.
4128 *
4129 * The conditions are provided as a list of RestrictInfo nodes, where the
4130 * caller has already determined that each condition is a mergejoinable
4131 * equality with an expression in this relation on one side, and an
4132 * expression not involving this relation on the other. The transient
4133 * outer_is_left flag is used to identify which side we should look at:
4134 * left side if outer_is_left is false, right side if it is true.
4135 *
4136 * The caller need only supply equality conditions arising from joins;
4137 * this routine automatically adds in any usable baserestrictinfo clauses.
4138 * (Note that the passed-in restrictlist will be destructively modified!)
4139 *
4140 * If extra_clauses isn't NULL, return baserestrictinfo clauses which were used
4141 * to derive uniqueness.
4142 */
4143bool
4144relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
4145 List *restrictlist, List **extra_clauses)
4146{
4147 ListCell *ic;
4148
4149 /* Short-circuit if no indexes... */
4150 if (rel->indexlist == NIL)
4151 return false;
4152
4153 /*
4154 * Examine the rel's restriction clauses for usable var = const clauses
4155 * that we can add to the restrictlist.
4156 */
4157 foreach(ic, rel->baserestrictinfo)
4158 {
4159 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
4160
4161 /*
4162 * Note: can_join won't be set for a restriction clause, but
4163 * mergeopfamilies will be if it has a mergejoinable operator and
4164 * doesn't contain volatile functions.
4165 */
4166 if (restrictinfo->mergeopfamilies == NIL)
4167 continue; /* not mergejoinable */
4168
4169 /*
4170 * The clause certainly doesn't refer to anything but the given rel.
4171 * If either side is pseudoconstant then we can use it.
4172 */
4173 if (bms_is_empty(restrictinfo->left_relids))
4174 {
4175 /* righthand side is inner */
4176 restrictinfo->outer_is_left = true;
4177 }
4178 else if (bms_is_empty(restrictinfo->right_relids))
4179 {
4180 /* lefthand side is inner */
4181 restrictinfo->outer_is_left = false;
4182 }
4183 else
4184 continue;
4185
4186 /* OK, add to list */
4187 restrictlist = lappend(restrictlist, restrictinfo);
4188 }
4189
4190 /* Short-circuit the easy case */
4191 if (restrictlist == NIL)
4192 return false;
4193
4194 /* Examine each index of the relation ... */
4195 foreach(ic, rel->indexlist)
4196 {
4197 IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
4198 int c;
4199 List *exprs = NIL;
4200
4201 /*
4202 * If the index is not unique, or not immediately enforced, or if it's
4203 * a partial index, it's useless here. We're unable to make use of
4204 * predOK partial unique indexes due to the fact that
4205 * check_index_predicates() also makes use of join predicates to
4206 * determine if the partial index is usable. Here we need proofs that
4207 * hold true before any joins are evaluated.
4208 */
4209 if (!ind->unique || !ind->immediate || ind->indpred != NIL)
4210 continue;
4211
4212 /*
4213 * Try to find each index column in the list of conditions. This is
4214 * O(N^2) or worse, but we expect all the lists to be short.
4215 */
4216 for (c = 0; c < ind->nkeycolumns; c++)
4217 {
4218 ListCell *lc;
4219
4220 foreach(lc, restrictlist)
4221 {
4222 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4223 Node *rexpr;
4224
4225 /*
4226 * The condition's equality operator must be a member of the
4227 * index opfamily, else it is not asserting the right kind of
4228 * equality behavior for this index. We check this first
4229 * since it's probably cheaper than match_index_to_operand().
4230 */
4231 if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
4232 continue;
4233
4234 /*
4235 * XXX at some point we may need to check collations here too.
4236 * For the moment we assume all collations reduce to the same
4237 * notion of equality.
4238 */
4239
4240 /* OK, see if the condition operand matches the index key */
4241 if (rinfo->outer_is_left)
4242 rexpr = get_rightop(rinfo->clause);
4243 else
4244 rexpr = get_leftop(rinfo->clause);
4245
4246 if (match_index_to_operand(rexpr, c, ind))
4247 {
4248 if (bms_membership(rinfo->clause_relids) == BMS_SINGLETON)
4249 {
4250 MemoryContext oldMemCtx =
4251 MemoryContextSwitchTo(root->planner_cxt);
4252
4253 /*
4254 * Add filter clause into a list allowing caller to
4255 * know if uniqueness have made not only by join
4256 * clauses.
4257 */
4258 Assert(bms_is_empty(rinfo->left_relids) ||
4259 bms_is_empty(rinfo->right_relids));
4260 if (extra_clauses)
4261 exprs = lappend(exprs, rinfo);
4262 MemoryContextSwitchTo(oldMemCtx);
4263 }
4264
4265 break; /* found a match; column is unique */
4266 }
4267 }
4268
4269 if (lc == NULL)
4270 break; /* no match; this index doesn't help us */
4271 }
4272
4273 /* Matched all key columns of this index? */
4274 if (c == ind->nkeycolumns)
4275 {
4276 if (extra_clauses)
4277 *extra_clauses = exprs;
4278 return true;
4279 }
4280 }
4281
4282 return false;
4283}
4284
4285/*
4286 * indexcol_is_bool_constant_for_query
4287 *
4288 * If an index column is constrained to have a constant value by the query's
4289 * WHERE conditions, then it's irrelevant for sort-order considerations.
4290 * Usually that means we have a restriction clause WHERE indexcol = constant,
4291 * which gets turned into an EquivalenceClass containing a constant, which
4292 * is recognized as redundant by build_index_pathkeys(). But if the index
4293 * column is a boolean variable (or expression), then we are not going to
4294 * see WHERE indexcol = constant, because expression preprocessing will have
4295 * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
4296 * going to have a matching EquivalenceClass (unless the query also contains
4297 * "ORDER BY indexcol"). To allow such cases to work the same as they would
4298 * for non-boolean values, this function is provided to detect whether the
4299 * specified index column matches a boolean restriction clause.
4300 */
4301bool
4302indexcol_is_bool_constant_for_query(PlannerInfo *root,
4303 IndexOptInfo *index,
4304 int indexcol)
4305{
4306 ListCell *lc;
4307
4308 /* If the index isn't boolean, we can't possibly get a match */
4309 if (!IsBooleanOpfamily(index->opfamily[indexcol]))
4310 return false;
4311
4312 /* Check each restriction clause for the index's rel */
4313 foreach(lc, index->rel->baserestrictinfo)
4314 {
4315 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4316
4317 /*
4318 * As in match_clause_to_indexcol, never match pseudoconstants to
4319 * indexes. (It might be semantically okay to do so here, but the
4320 * odds of getting a match are negligible, so don't waste the cycles.)
4321 */
4322 if (rinfo->pseudoconstant)
4323 continue;
4324
4325 /* See if we can match the clause's expression to the index column */
4326 if (match_boolean_index_clause(root, rinfo, indexcol, index))
4327 return true;
4328 }
4329
4330 return false;
4331}
4332
4333
4334/****************************************************************************
4335 * ---- ROUTINES TO CHECK OPERANDS ----
4336 ****************************************************************************/
4337
4338/*
4339 * match_index_to_operand()
4340 * Generalized test for a match between an index's key
4341 * and the operand on one side of a restriction or join clause.
4342 *
4343 * operand: the nodetree to be compared to the index
4344 * indexcol: the column number of the index (counting from 0)
4345 * index: the index of interest
4346 *
4347 * Note that we aren't interested in collations here; the caller must check
4348 * for a collation match, if it's dealing with an operator where that matters.
4349 *
4350 * This is exported for use in selfuncs.c.
4351 */
4352bool
4353match_index_to_operand(Node *operand,
4354 int indexcol,
4355 IndexOptInfo *index)
4356{
4357 int indkey;
4358
4359 /*
4360 * Ignore any PlaceHolderVar node contained in the operand. This is
4361 * needed to be able to apply indexscanning in cases where the operand (or
4362 * a subtree) has been wrapped in PlaceHolderVars to enforce separate
4363 * identity or as a result of outer joins.
4364 */
4365 operand = strip_noop_phvs(operand);
4366
4367 /*
4368 * Ignore any RelabelType node above the operand. This is needed to be
4369 * able to apply indexscanning in binary-compatible-operator cases.
4370 *
4371 * Note: we must handle nested RelabelType nodes here. While
4372 * eval_const_expressions() will have simplified them to at most one
4373 * layer, our prior stripping of PlaceHolderVars may have brought separate
4374 * RelabelTypes into adjacency.
4375 */
4376 while (operand && IsA(operand, RelabelType))
4377 operand = (Node *) ((RelabelType *) operand)->arg;
4378
4379 indkey = index->indexkeys[indexcol];
4380 if (indkey != 0)
4381 {
4382 /*
4383 * Simple index column; operand must be a matching Var.
4384 */
4385 if (operand && IsA(operand, Var) &&
4386 index->rel->relid == ((Var *) operand)->varno &&
4387 indkey == ((Var *) operand)->varattno &&
4388 ((Var *) operand)->varnullingrels == NULL)
4389 return true;
4390 }
4391 else
4392 {
4393 /*
4394 * Index expression; find the correct expression. (This search could
4395 * be avoided, at the cost of complicating all the callers of this
4396 * routine; doesn't seem worth it.)
4397 */
4398 ListCell *indexpr_item;
4399 int i;
4400 Node *indexkey;
4401
4402 indexpr_item = list_head(index->indexprs);
4403 for (i = 0; i < indexcol; i++)
4404 {
4405 if (index->indexkeys[i] == 0)
4406 {
4407 if (indexpr_item == NULL)
4408 elog(ERROR, "wrong number of index expressions");
4409 indexpr_item = lnext(index->indexprs, indexpr_item);
4410 }
4411 }
4412 if (indexpr_item == NULL)
4413 elog(ERROR, "wrong number of index expressions");
4414 indexkey = (Node *) lfirst(indexpr_item);
4415
4416 /*
4417 * Does it match the operand? Again, strip any relabeling.
4418 */
4419 if (indexkey && IsA(indexkey, RelabelType))
4420 indexkey = (Node *) ((RelabelType *) indexkey)->arg;
4421
4422 if (equal(indexkey, operand))
4423 return true;
4424 }
4425
4426 return false;
4427}
4428
4429/*
4430 * is_pseudo_constant_for_index()
4431 * Test whether the given expression can be used as an indexscan
4432 * comparison value.
4433 *
4434 * An indexscan comparison value must not contain any volatile functions,
4435 * and it can't contain any Vars of the index's own table. Vars of
4436 * other tables are okay, though; in that case we'd be producing an
4437 * indexqual usable in a parameterized indexscan. This is, therefore,
4438 * a weaker condition than is_pseudo_constant_clause().
4439 *
4440 * This function is exported for use by planner support functions,
4441 * which will have available the IndexOptInfo, but not any RestrictInfo
4442 * infrastructure. It is making the same test made by functions above
4443 * such as match_opclause_to_indexcol(), but those rely where possible
4444 * on RestrictInfo information about variable membership.
4445 *
4446 * expr: the nodetree to be checked
4447 * index: the index of interest
4448 */
4449bool
4450is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
4451{
4452 /* pull_varnos is cheaper than volatility check, so do that first */
4453 if (bms_is_member(index->rel->relid, pull_varnos(root, expr)))
4454 return false; /* no good, contains Var of table */
4455 if (contain_volatile_functions(expr))
4456 return false; /* no good, volatile comparison value */
4457 return true;
4458}
create_partial_bitmap_paths
void create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual)
Definition allpaths.c:4758
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:1290
bms_del_members
Bitmapset * bms_del_members(Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:1145
bms_del_member
Bitmapset * bms_del_member(Bitmapset *a, int x)
Definition bitmapset.c:852
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:799
bms_add_members
Bitmapset * bms_add_members(Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:901
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:765
bms_overlap
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition bitmapset.c:575
bms_copy
Bitmapset * bms_copy(const Bitmapset *a)
Definition bitmapset.c:122
bms_is_empty
#define bms_is_empty(a)
Definition bitmapset.h:118
BMS_DIFFERENT
@ BMS_DIFFERENT
Definition bitmapset.h:65
BMS_SINGLETON
@ BMS_SINGLETON
Definition bitmapset.h:72
Assert
#define Assert(condition)
Definition c.h:943
Index
unsigned int Index
Definition c.h:698
MemSet
#define MemSet(start, val, len)
Definition c.h:1107
OidIsValid
#define OidIsValid(objectId)
Definition c.h:858
result
uint32 result
Definition checksum_block_internal.h:18
memcpy
memcpy(sums, checksumBaseOffsets, sizeof(checksumBaseOffsets))
contain_mutable_functions
bool contain_mutable_functions(Node *clause)
Definition clauses.c:381
make_SAOP_expr
ScalarArrayOpExpr * make_SAOP_expr(Oid oper, Node *leftexpr, Oid coltype, Oid arraycollid, Oid inputcollid, List *exprs, bool haveNonConst)
Definition clauses.c:6244
contain_volatile_functions
bool contain_volatile_functions(Node *clause)
Definition clauses.c:549
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:1115
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:1012
arg
Datum arg
Definition elog.c:1322
ERROR
#define ERROR
Definition elog.h:40
elog
#define elog(elevel,...)
Definition elog.h:228
equal
bool equal(const void *a, const void *b)
Definition equalfuncs.c:223
setup_eclass_member_iterator
void setup_eclass_member_iterator(EquivalenceMemberIterator *it, EquivalenceClass *ec, Relids child_relids)
Definition equivclass.c:3155
generate_implied_equalities_for_column
List * generate_implied_equalities_for_column(PlannerInfo *root, RelOptInfo *rel, ec_matches_callback_type callback, void *callback_arg, Relids prohibited_rels)
Definition equivclass.c:3238
eclass_member_iterator_next
EquivalenceMember * eclass_member_iterator_next(EquivalenceMemberIterator *it)
Definition equivclass.c:3174
generate_join_implied_equalities
List * generate_join_implied_equalities(PlannerInfo *root, Relids join_relids, Relids outer_relids, RelOptInfo *inner_rel, SpecialJoinInfo *sjinfo)
Definition equivclass.c:1549
palloc_object
#define palloc_object(type)
Definition fe_memutils.h:74
palloc_array
#define palloc_array(type, count)
Definition fe_memutils.h:76
OidFunctionCall1
#define OidFunctionCall1(functionId, arg1)
Definition fmgr.h:722
IsBooleanOpfamily
static bool IsBooleanOpfamily(Oid opfamily)
Definition indxpath.c:2790
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:2056
find_indexpath_quals
static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
Definition indxpath.c:2153
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:2585
is_pseudo_constant_for_index
bool is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
Definition indxpath.c:4450
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:2480
match_saopclause_to_indexcol
static IndexClause * match_saopclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3133
check_index_only
static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index)
Definition indxpath.c:2226
match_eclass_clauses_to_index
static void match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2514
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:2085
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:3940
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:3715
find_list_position
static int find_list_position(Node *node, List **nodelist)
Definition indxpath.c:2200
match_clauses_to_index
static void match_clauses_to_index(PlannerInfo *root, List *clauses, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2552
get_loop_count
static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
Definition indxpath.c:2325
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:2378
match_clause_to_indexcol
static IndexClause * match_clause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:2709
ec_member_matches_indexcol
static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, EquivalenceMember *em, void *arg)
Definition indxpath.c:4088
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:3067
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:3295
match_opclause_to_indexcol
static IndexClause * match_opclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:2902
bitmap_scan_cost_est
static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
Definition indxpath.c:2022
match_index_to_operand
bool match_index_to_operand(Node *operand, int indexcol, IndexOptInfo *index)
Definition indxpath.c:4353
match_boolean_index_clause
static IndexClause * match_boolean_index_clause(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:2815
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:3493
match_restriction_clauses_to_index
static void match_restriction_clauses_to_index(PlannerInfo *root, IndexOptInfo *index, IndexClauseSet *clauseset)
Definition indxpath.c:2464
match_rowcompare_to_indexcol
static IndexClause * match_rowcompare_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3201
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:4302
match_funcclause_to_indexcol
static IndexClause * match_funcclause_to_indexcol(PlannerInfo *root, RestrictInfo *rinfo, int indexcol, IndexOptInfo *index)
Definition indxpath.c:3021
path_usage_comparator
static int path_usage_comparator(const void *a, const void *b)
Definition indxpath.c:1989
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:2422
match_clause_to_ordering_op
static Expr * match_clause_to_ordering_op(IndexOptInfo *index, int indexcol, Expr *clause, Oid pk_opfamily)
Definition indxpath.c:3826
relation_has_unique_index_for
bool relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel, List *restrictlist, List **extra_clauses)
Definition indxpath.c:4144
generate_bitmap_or_paths
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
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:140
get_op_opfamily_sortfamily
Oid get_op_opfamily_sortfamily(Oid opno, Oid opfamily)
Definition lsyscache.c:112
get_func_support
RegProcedure get_func_support(Oid funcid)
Definition lsyscache.c:2078
get_op_opfamily_strategy
int get_op_opfamily_strategy(Oid opno, Oid opfamily)
Definition lsyscache.c:87
get_opfamily_member
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition lsyscache.c:170
get_array_type
Oid get_array_type(Oid typid)
Definition lsyscache.c:3009
op_in_opfamily
bool op_in_opfamily(Oid opno, Oid opfamily)
Definition lsyscache.c:70
get_commutator
Oid get_commutator(Oid opno)
Definition lsyscache.c:1729
make_orclause
Expr * make_orclause(List *orclauses)
Definition makefuncs.c:743
makeBoolConst
Node * makeBoolConst(bool value, bool isnull)
Definition makefuncs.c:408
make_opclause
Expr * make_opclause(Oid opno, Oid opresulttype, bool opretset, Expr *leftop, Expr *rightop, Oid opcollid, Oid inputcollid)
Definition makefuncs.c:701
pfree
void pfree(void *pointer)
Definition mcxt.c:1616
exprType
Oid exprType(const Node *expr)
Definition nodeFuncs.c:42
set_opfuncid
void set_opfuncid(OpExpr *opexpr)
Definition nodeFuncs.c:1879
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:232
Cost
double Cost
Definition nodes.h:261
nodeTag
#define nodeTag(nodeptr)
Definition nodes.h:139
Selectivity
double Selectivity
Definition nodes.h:260
makeNode
#define makeNode(_type_)
Definition nodes.h:161
castNode
#define castNode(_type_, nodeptr)
Definition nodes.h:182
JOIN_SEMI
@ JOIN_SEMI
Definition nodes.h:317
MemoryContextSwitchTo
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition palloc.h:124
truncate_useless_pathkeys
List * truncate_useless_pathkeys(PlannerInfo *root, RelOptInfo *rel, List *pathkeys)
Definition pathkeys.c:2200
has_useful_pathkeys
bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel)
Definition pathkeys.c:2291
build_index_pathkeys
List * build_index_pathkeys(PlannerInfo *root, IndexOptInfo *index, ScanDirection scandir)
Definition pathkeys.c:740
create_bitmap_and_path
BitmapAndPath * create_bitmap_and_path(PlannerInfo *root, RelOptInfo *rel, List *bitmapquals)
Definition pathnode.c:1182
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:1092
add_partial_path
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition pathnode.c:793
create_bitmap_or_path
BitmapOrPath * create_bitmap_or_path(PlannerInfo *root, RelOptInfo *rel, List *bitmapquals)
Definition pathnode.c:1234
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:1149
add_path
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition pathnode.c:459
IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel)
Definition pathnodes.h:989
IS_DUMMY_REL
#define IS_DUMMY_REL(r)
Definition pathnodes.h:2299
PGS_CONSIDER_INDEXONLY
#define PGS_CONSIDER_INDEXONLY
Definition pathnodes.h:82
PATH_REQ_OUTER
#define PATH_REQ_OUTER(path)
Definition pathnodes.h:2015
Relids
Bitmapset * Relids
Definition pathnodes.h:103
RELOPT_OTHER_MEMBER_REL
@ RELOPT_OTHER_MEMBER_REL
Definition pathnodes.h:979
pg_am.h
pg_amop.h
INDEX_MAX_KEYS
#define INDEX_MAX_KEYS
Definition pg_config_manual.h:79
lfirst
#define lfirst(lc)
Definition pg_list.h:172
lfirst_node
#define lfirst_node(type, lc)
Definition pg_list.h:176
list_length
static int list_length(const List *l)
Definition pg_list.h:152
NIL
#define NIL
Definition pg_list.h:68
list_nth_oid
static Oid list_nth_oid(const List *list, int n)
Definition pg_list.h:353
list_make1_oid
#define list_make1_oid(x1)
Definition pg_list.h:274
list_make1
#define list_make1(x1)
Definition pg_list.h:244
forthree
#define forthree(cell1, list1, cell2, list2, cell3, list3)
Definition pg_list.h:595
list_nth
static void * list_nth(const List *list, int n)
Definition pg_list.h:331
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:375
list_make1_int
#define list_make1_int(x1)
Definition pg_list.h:259
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:246
pg_operator.h
pg_opfamily.h
pg_type.h
strip_noop_phvs
Node * strip_noop_phvs(Node *node)
Definition placeholder.c:614
qsort
#define qsort(a, b, c, d)
Definition port.h:495
PointerGetDatum
static Datum PointerGetDatum(const void *X)
Definition postgres.h:342
DatumGetPointer
static Pointer DatumGetPointer(Datum X)
Definition postgres.h:332
InvalidOid
#define InvalidOid
Definition postgres_ext.h:37
Oid
unsigned int Oid
Definition postgres_ext.h:32
predicate_implied_by
bool predicate_implied_by(List *predicate_list, List *clause_list, bool weak)
Definition predtest.c:154
c
char * c
Definition preproc-cursor.c:31
fb
static int fb(int x)
Definition preproc-init.c:92
get_plan_rowmark
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition preptlist.c:528
IS_TRUE
@ IS_TRUE
Definition primnodes.h:2004
IS_FALSE
@ IS_FALSE
Definition primnodes.h:2004
root
tree ctl root
Definition radixtree.h:1857
find_childrel_parents
Relids find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
Definition relnode.c:1668
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:3788
BTGreaterStrategyNumber
#define BTGreaterStrategyNumber
Definition stratnum.h:33
BTLessStrategyNumber
#define BTLessStrategyNumber
Definition stratnum.h:29
BTLessEqualStrategyNumber
#define BTLessEqualStrategyNumber
Definition stratnum.h:30
BTGreaterEqualStrategyNumber
#define BTGreaterEqualStrategyNumber
Definition stratnum.h:32
FuncExpr::funcid
Oid funcid
Definition primnodes.h:783
FuncExpr::args
List * args
Definition primnodes.h:801
IndexClauseSet::indexclauses
List * indexclauses[INDEX_MAX_KEYS]
Definition indxpath.c:57
List
Definition pg_list.h:54
List::type
NodeTag type
Definition pg_list.h:55
Node
Definition nodes.h:135
OpExpr::opno
Oid opno
Definition primnodes.h:851
OpExpr::args
List * args
Definition primnodes.h:869
PathClauseUsage::clauseids
Bitmapset * clauseids
Definition indxpath.c:66
PathClauseUsage::unclassifiable
bool unclassifiable
Definition indxpath.c:67
PathTarget::exprs
List * exprs
Definition pathnodes.h:1878
Path::pathtype
NodeTag pathtype
Definition pathnodes.h:1971
Path::total_cost
Cost total_cost
Definition pathnodes.h:2008
RelOptInfo::baserestrictinfo
List * baserestrictinfo
Definition pathnodes.h:1142
RelOptInfo::joininfo
List * joininfo
Definition pathnodes.h:1148
RelOptInfo::relids
Relids relids
Definition pathnodes.h:1021
RelOptInfo::reltarget
struct PathTarget * reltarget
Definition pathnodes.h:1045
RelOptInfo::relid
Index relid
Definition pathnodes.h:1069
RelOptInfo::pgs_mask
uint64 pgs_mask
Definition pathnodes.h:1039
RelOptInfo::consider_parallel
bool consider_parallel
Definition pathnodes.h:1037
RelOptInfo::lateral_relids
Relids lateral_relids
Definition pathnodes.h:1064
RelOptInfo::reloptkind
RelOptKind reloptkind
Definition pathnodes.h:1015
RelOptInfo::indexlist
List * indexlist
Definition pathnodes.h:1091
RelOptInfo::nulling_relids
Relids nulling_relids
Definition pathnodes.h:1085
RelOptInfo::rows
Cardinality rows
Definition pathnodes.h:1027
RestrictInfo::is_pushed_down
bool is_pushed_down
Definition pathnodes.h:2904
RestrictInfo::security_level
Index security_level
Definition pathnodes.h:2923
RestrictInfo::required_relids
Relids required_relids
Definition pathnodes.h:2932
RestrictInfo::outer_relids
Relids outer_relids
Definition pathnodes.h:2938
RestrictInfo::incompatible_relids
Relids incompatible_relids
Definition pathnodes.h:2935
RestrictInfo::clause
Expr * clause
Definition pathnodes.h:2901
RowCompareExpr::cmptype
CompareType cmptype
Definition primnodes.h:1495
SpecialJoinInfo::syn_lefthand
Relids syn_lefthand
Definition pathnodes.h:3228
SpecialJoinInfo::semi_rhs_exprs
List * semi_rhs_exprs
Definition pathnodes.h:3241
SpecialJoinInfo::jointype
JoinType jointype
Definition pathnodes.h:3230
SpecialJoinInfo::syn_righthand
Relids syn_righthand
Definition pathnodes.h:3229
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