Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * indxpath.c
4 : * Routines to determine which indexes are usable for scanning a
5 : * given relation, and create Paths accordingly.
6 : *
7 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : *
11 : * IDENTIFICATION
12 : * src/backend/optimizer/path/indxpath.c
13 : *
14 : *-------------------------------------------------------------------------
15 : */
16 : #include "postgres.h"
17 :
18 : #include <math.h>
19 :
20 : #include "access/stratnum.h"
21 : #include "access/sysattr.h"
22 : #include "catalog/pg_am.h"
23 : #include "catalog/pg_amop.h"
24 : #include "catalog/pg_operator.h"
25 : #include "catalog/pg_opfamily.h"
26 : #include "catalog/pg_type.h"
27 : #include "nodes/makefuncs.h"
28 : #include "nodes/nodeFuncs.h"
29 : #include "nodes/supportnodes.h"
30 : #include "optimizer/cost.h"
31 : #include "optimizer/optimizer.h"
32 : #include "optimizer/pathnode.h"
33 : #include "optimizer/paths.h"
34 : #include "optimizer/prep.h"
35 : #include "optimizer/restrictinfo.h"
36 : #include "utils/lsyscache.h"
37 : #include "utils/selfuncs.h"
38 :
39 :
40 : /* XXX see PartCollMatchesExprColl */
41 : #define IndexCollMatchesExprColl(idxcollation, exprcollation) \
42 : ((idxcollation) == InvalidOid || (idxcollation) == (exprcollation))
43 :
44 : /* Whether we are looking for plain indexscan, bitmap scan, or either */
45 : typedef 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 */
53 : typedef 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() */
61 : typedef 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 */
71 : typedef 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 :
78 : static void consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
79 : IndexOptInfo *index,
80 : IndexClauseSet *rclauseset,
81 : IndexClauseSet *jclauseset,
82 : IndexClauseSet *eclauseset,
83 : List **bitindexpaths);
84 : static 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);
93 : static 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);
101 : static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
102 : List *indexjoinclauses);
103 : static void get_index_paths(PlannerInfo *root, RelOptInfo *rel,
104 : IndexOptInfo *index, IndexClauseSet *clauses,
105 : List **bitindexpaths);
106 : static 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);
111 : static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
112 : List *clauses, List *other_clauses);
113 : static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
114 : List *clauses, List *other_clauses);
115 : static Path *choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel,
116 : List *paths);
117 : static int path_usage_comparator(const void *a, const void *b);
118 : static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel,
119 : Path *ipath);
120 : static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel,
121 : List *paths);
122 : static PathClauseUsage *classify_index_clause_usage(Path *path,
123 : List **clauselist);
124 : static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds);
125 : static int find_list_position(Node *node, List **nodelist);
126 : static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index);
127 : static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids);
128 : static double adjust_rowcount_for_semijoins(PlannerInfo *root,
129 : Index cur_relid,
130 : Index outer_relid,
131 : double rowcount);
132 : static double approximate_joinrel_size(PlannerInfo *root, Relids relids);
133 : static void match_restriction_clauses_to_index(PlannerInfo *root,
134 : IndexOptInfo *index,
135 : IndexClauseSet *clauseset);
136 : static void match_join_clauses_to_index(PlannerInfo *root,
137 : RelOptInfo *rel, IndexOptInfo *index,
138 : IndexClauseSet *clauseset,
139 : List **joinorclauses);
140 : static void match_eclass_clauses_to_index(PlannerInfo *root,
141 : IndexOptInfo *index,
142 : IndexClauseSet *clauseset);
143 : static void match_clauses_to_index(PlannerInfo *root,
144 : List *clauses,
145 : IndexOptInfo *index,
146 : IndexClauseSet *clauseset);
147 : static void match_clause_to_index(PlannerInfo *root,
148 : RestrictInfo *rinfo,
149 : IndexOptInfo *index,
150 : IndexClauseSet *clauseset);
151 : static IndexClause *match_clause_to_indexcol(PlannerInfo *root,
152 : RestrictInfo *rinfo,
153 : int indexcol,
154 : IndexOptInfo *index);
155 : static bool IsBooleanOpfamily(Oid opfamily);
156 : static IndexClause *match_boolean_index_clause(PlannerInfo *root,
157 : RestrictInfo *rinfo,
158 : int indexcol, IndexOptInfo *index);
159 : static IndexClause *match_opclause_to_indexcol(PlannerInfo *root,
160 : RestrictInfo *rinfo,
161 : int indexcol,
162 : IndexOptInfo *index);
163 : static IndexClause *match_funcclause_to_indexcol(PlannerInfo *root,
164 : RestrictInfo *rinfo,
165 : int indexcol,
166 : IndexOptInfo *index);
167 : static IndexClause *get_index_clause_from_support(PlannerInfo *root,
168 : RestrictInfo *rinfo,
169 : Oid funcid,
170 : int indexarg,
171 : int indexcol,
172 : IndexOptInfo *index);
173 : static IndexClause *match_saopclause_to_indexcol(PlannerInfo *root,
174 : RestrictInfo *rinfo,
175 : int indexcol,
176 : IndexOptInfo *index);
177 : static IndexClause *match_rowcompare_to_indexcol(PlannerInfo *root,
178 : RestrictInfo *rinfo,
179 : int indexcol,
180 : IndexOptInfo *index);
181 : static IndexClause *match_orclause_to_indexcol(PlannerInfo *root,
182 : RestrictInfo *rinfo,
183 : int indexcol,
184 : IndexOptInfo *index);
185 : static IndexClause *expand_indexqual_rowcompare(PlannerInfo *root,
186 : RestrictInfo *rinfo,
187 : int indexcol,
188 : IndexOptInfo *index,
189 : Oid expr_op,
190 : bool var_on_left);
191 : static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
192 : List **orderby_clauses_p,
193 : List **clause_columns_p);
194 : static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
195 : int indexcol, Expr *clause, Oid pk_opfamily);
196 : static 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 : */
238 : void
239 404226 : create_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 404226 : if (rel->indexlist == NIL)
252 68778 : return;
253 :
254 : /* Bitmap paths are collected and then dealt with at the end */
255 335448 : bitindexpaths = bitjoinpaths = joinorclauses = NIL;
256 :
257 : /* Examine each index in turn */
258 1059964 : foreach(lc, rel->indexlist)
259 : {
260 724516 : 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 724516 : if (index->indpred != NIL && !index->predOK)
271 496 : continue;
272 :
273 : /*
274 : * Identify the restriction clauses that can match the index.
275 : */
276 24616680 : MemSet(&rclauseset, 0, sizeof(rclauseset));
277 724020 : 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 724020 : 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 24616680 : MemSet(&jclauseset, 0, sizeof(jclauseset));
294 724020 : 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 24616680 : MemSet(&eclauseset, 0, sizeof(eclauseset));
302 724020 : 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 724020 : if (jclauseset.nonempty || eclauseset.nonempty)
310 131430 : 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 335448 : indexpaths = generate_bitmap_or_paths(root, rel,
322 : rel->baserestrictinfo, NIL);
323 335448 : 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 335448 : indexpaths = generate_bitmap_or_paths(root, rel,
330 : joinorclauses, rel->baserestrictinfo);
331 335448 : 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 335448 : if (bitindexpaths != NIL)
341 : {
342 : Path *bitmapqual;
343 : BitmapHeapPath *bpath;
344 :
345 202014 : bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
346 202014 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
347 : rel->lateral_relids, 1.0, 0);
348 202014 : add_path(rel, (Path *) bpath);
349 :
350 : /* create a partial bitmap heap path */
351 202014 : if (rel->consider_parallel && rel->lateral_relids == NULL)
352 145428 : 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 335448 : if (bitjoinpaths != NIL)
366 : {
367 : List *all_path_outers;
368 :
369 : /* Identify each distinct parameterization seen in bitjoinpaths */
370 120170 : all_path_outers = NIL;
371 265320 : foreach(lc, bitjoinpaths)
372 : {
373 145150 : Path *path = (Path *) lfirst(lc);
374 145150 : Relids required_outer = PATH_REQ_OUTER(path);
375 :
376 145150 : all_path_outers = list_append_unique(all_path_outers,
377 : required_outer);
378 : }
379 :
380 : /* Now, for each distinct parameterization set ... */
381 258200 : foreach(lc, all_path_outers)
382 : {
383 138030 : 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 138030 : this_path_set = NIL;
393 331522 : foreach(lcp, bitjoinpaths)
394 : {
395 193492 : Path *path = (Path *) lfirst(lcp);
396 :
397 193492 : if (bms_is_subset(PATH_REQ_OUTER(path), max_outers))
398 152132 : 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 138030 : this_path_set = list_concat(this_path_set, bitindexpaths);
406 :
407 : /* Select best AND combination for this parameterization */
408 138030 : bitmapqual = choose_bitmap_and(root, rel, this_path_set);
409 :
410 : /* And push that path into the mix */
411 138030 : required_outer = PATH_REQ_OUTER(bitmapqual);
412 138030 : loop_count = get_loop_count(root, rel->relid, required_outer);
413 138030 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
414 : required_outer, loop_count, 0);
415 138030 : 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 : */
435 : static void
436 131430 : consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
437 : IndexOptInfo *index,
438 : IndexClauseSet *rclauseset,
439 : IndexClauseSet *jclauseset,
440 : IndexClauseSet *eclauseset,
441 : List **bitindexpaths)
442 : {
443 131430 : int considered_clauses = 0;
444 131430 : 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 328382 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
469 : {
470 : /* Consider each applicable simple join clause */
471 196952 : considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
472 196952 : 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 196952 : considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
480 196952 : 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 131430 : }
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 : */
501 : static void
502 393904 : consider_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 538538 : foreach(lc, indexjoinclauses)
516 : {
517 144634 : IndexClause *iclause = (IndexClause *) lfirst(lc);
518 144634 : Relids clause_relids = iclause->rinfo->clause_relids;
519 144634 : 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 144634 : if (list_member(*considered_relids, clause_relids))
524 2886 : 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 141748 : num_considered_relids = list_length(*considered_relids);
540 152432 : for (int pos = 0; pos < num_considered_relids; pos++)
541 : {
542 10684 : 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 10684 : if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
551 24 : 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 21158 : if (parent_ec &&
562 10498 : eclass_already_used(parent_ec, oldrelids,
563 : indexjoinclauses))
564 7240 : 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 3420 : if (list_length(*considered_relids) >= 10 * considered_clauses)
572 0 : break;
573 :
574 : /* OK, try the union set */
575 3420 : 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 141748 : get_join_index_paths(root, rel, index,
584 : rclauseset, jclauseset, eclauseset,
585 : bitindexpaths,
586 : clause_relids,
587 : considered_relids);
588 : }
589 393904 : }
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 : */
604 : static void
605 145168 : get_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 145168 : if (list_member(*considered_relids, relids))
619 0 : return;
620 :
621 : /* Identify indexclauses usable with this relids set */
622 4935712 : MemSet(&clauseset, 0, sizeof(clauseset));
623 :
624 367890 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
625 : {
626 : ListCell *lc;
627 :
628 : /* First find applicable simple join clauses */
629 259054 : foreach(lc, jclauseset->indexclauses[indexcol])
630 : {
631 36332 : IndexClause *iclause = (IndexClause *) lfirst(lc);
632 :
633 36332 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
634 35906 : clauseset.indexclauses[indexcol] =
635 35906 : 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 238264 : foreach(lc, eclauseset->indexclauses[indexcol])
645 : {
646 131038 : IndexClause *iclause = (IndexClause *) lfirst(lc);
647 :
648 131038 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
649 : {
650 115496 : clauseset.indexclauses[indexcol] =
651 115496 : lappend(clauseset.indexclauses[indexcol], iclause);
652 115496 : break;
653 : }
654 : }
655 :
656 : /* Add restriction clauses */
657 222722 : clauseset.indexclauses[indexcol] =
658 222722 : list_concat(clauseset.indexclauses[indexcol],
659 222722 : rclauseset->indexclauses[indexcol]);
660 :
661 222722 : if (clauseset.indexclauses[indexcol] != NIL)
662 178552 : 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 145168 : get_index_paths(root, rel, index, &clauseset, bitindexpaths);
670 :
671 : /*
672 : * Remember we considered paths for this set of relids.
673 : */
674 145168 : *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 : */
682 : static bool
683 10498 : eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
684 : List *indexjoinclauses)
685 : {
686 : ListCell *lc;
687 :
688 14218 : foreach(lc, indexjoinclauses)
689 : {
690 10960 : IndexClause *iclause = (IndexClause *) lfirst(lc);
691 10960 : RestrictInfo *rinfo = iclause->rinfo;
692 :
693 21920 : if (rinfo->parent_ec == parent_ec &&
694 10960 : bms_is_subset(rinfo->clause_relids, oldrelids))
695 7240 : return true;
696 : }
697 3258 : 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 : */
714 : static void
715 869188 : get_index_paths(PlannerInfo *root, RelOptInfo *rel,
716 : IndexOptInfo *index, IndexClauseSet *clauses,
717 : List **bitindexpaths)
718 : {
719 : List *indexpaths;
720 869188 : 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 869188 : indexpaths = build_index_paths(root, rel,
728 : index, clauses,
729 869188 : 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 1380102 : foreach(lc, indexpaths)
746 : {
747 510914 : IndexPath *ipath = (IndexPath *) lfirst(lc);
748 :
749 510914 : if (index->amhasgettuple)
750 497512 : add_path(rel, (Path *) ipath);
751 :
752 510914 : if (index->amhasgetbitmap &&
753 510914 : (ipath->path.pathkeys == NIL ||
754 313708 : ipath->indexselectivity < 1.0))
755 374244 : *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 869188 : if (skip_nonnative_saop)
764 : {
765 32 : indexpaths = build_index_paths(root, rel,
766 : index, clauses,
767 : false,
768 : ST_BITMAPSCAN,
769 : NULL);
770 32 : *bitindexpaths = list_concat(*bitindexpaths, indexpaths);
771 : }
772 869188 : }
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 : */
808 : static List *
809 872216 : build_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 872216 : 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 872216 : switch (scantype)
835 : {
836 0 : case ST_INDEXSCAN:
837 0 : if (!index->amhasgettuple)
838 0 : return NIL;
839 0 : break;
840 3028 : case ST_BITMAPSCAN:
841 3028 : if (!index->amhasgetbitmap)
842 0 : return NIL;
843 3028 : break;
844 869188 : case ST_ANYSCAN:
845 : /* either or both are OK */
846 869188 : 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 872216 : index_clauses = NIL;
862 872216 : outer_relids = bms_copy(rel->lateral_relids);
863 2477498 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
864 : {
865 : ListCell *lc;
866 :
867 2041648 : foreach(lc, clauses->indexclauses[indexcol])
868 : {
869 436036 : IndexClause *iclause = (IndexClause *) lfirst(lc);
870 436036 : RestrictInfo *rinfo = iclause->rinfo;
871 :
872 436036 : if (skip_nonnative_saop && !index->amsearcharray &&
873 21248 : 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 32 : *skip_nonnative_saop = true;
883 32 : continue;
884 : }
885 :
886 : /* OK to include this clause */
887 436004 : index_clauses = lappend(index_clauses, iclause);
888 436004 : outer_relids = bms_add_members(outer_relids,
889 436004 : 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 1605612 : if (index_clauses == NIL && !index->amoptionalkey)
901 330 : return NIL;
902 : }
903 :
904 : /* We do not want the index's rel itself listed in outer_relids */
905 871886 : outer_relids = bms_del_member(outer_relids, rel->relid);
906 :
907 : /* Compute loop_count for cost estimation purposes */
908 871886 : 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 1740744 : pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN &&
916 868858 : has_useful_pathkeys(root, rel));
917 871886 : index_is_ordered = (index->sortopfamily != NULL);
918 871886 : if (index_is_ordered && pathkeys_possibly_useful)
919 : {
920 647494 : index_pathkeys = build_index_pathkeys(root, index,
921 : ForwardScanDirection);
922 647494 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
923 : index_pathkeys);
924 647494 : orderbyclauses = NIL;
925 647494 : orderbyclausecols = NIL;
926 : }
927 224392 : 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 1074 : match_pathkeys_to_index(index, root->query_pathkeys,
936 : &orderbyclauses,
937 : &orderbyclausecols);
938 1074 : if (list_length(root->query_pathkeys) == list_length(orderbyclauses))
939 468 : useful_pathkeys = root->query_pathkeys;
940 : else
941 606 : useful_pathkeys = list_copy_head(root->query_pathkeys,
942 : list_length(orderbyclauses));
943 : }
944 : else
945 : {
946 223318 : useful_pathkeys = NIL;
947 223318 : orderbyclauses = NIL;
948 223318 : 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 1740744 : index_only_scan = (scantype != ST_BITMAPSCAN &&
957 868858 : 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 871886 : if (index_clauses != NIL || useful_pathkeys != NIL || useful_predicate ||
966 : index_only_scan)
967 : {
968 513352 : 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 513352 : 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 513352 : if (index->amcanparallel &&
985 492982 : rel->consider_parallel && outer_relids == NULL &&
986 : scantype != ST_BITMAPSCAN)
987 : {
988 273154 : 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 273154 : if (ipath->path.parallel_workers > 0)
1004 9854 : add_partial_path(rel, (Path *) ipath);
1005 : else
1006 263300 : pfree(ipath);
1007 : }
1008 : }
1009 :
1010 : /*
1011 : * 5. If the index is ordered, a backwards scan might be interesting.
1012 : */
1013 871886 : if (index_is_ordered && pathkeys_possibly_useful)
1014 : {
1015 647494 : index_pathkeys = build_index_pathkeys(root, index,
1016 : BackwardScanDirection);
1017 647494 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
1018 : index_pathkeys);
1019 647494 : if (useful_pathkeys != NIL)
1020 : {
1021 590 : 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 590 : result = lappend(result, ipath);
1032 :
1033 : /* If appropriate, consider parallel index scan */
1034 590 : if (index->amcanparallel &&
1035 590 : rel->consider_parallel && outer_relids == NULL &&
1036 : scantype != ST_BITMAPSCAN)
1037 : {
1038 500 : 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 500 : if (ipath->path.parallel_workers > 0)
1054 168 : add_partial_path(rel, (Path *) ipath);
1055 : else
1056 332 : pfree(ipath);
1057 : }
1058 : }
1059 : }
1060 :
1061 871886 : 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 : */
1090 : static List *
1091 11894 : build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
1092 : List *clauses, List *other_clauses)
1093 : {
1094 11894 : List *result = NIL;
1095 11894 : List *all_clauses = NIL; /* not computed till needed */
1096 : ListCell *lc;
1097 :
1098 41272 : foreach(lc, rel->indexlist)
1099 : {
1100 29378 : 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 29378 : if (!index->amhasgetbitmap)
1107 26382 : 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 29378 : useful_predicate = false;
1122 29378 : if (index->indpred != NIL)
1123 : {
1124 168 : 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 144 : if (all_clauses == NIL)
1132 60 : all_clauses = list_concat_copy(clauses, other_clauses);
1133 :
1134 144 : if (!predicate_implied_by(index->indpred, all_clauses, false))
1135 96 : continue; /* can't use it at all */
1136 :
1137 48 : if (!predicate_implied_by(index->indpred, other_clauses, false))
1138 48 : useful_predicate = true;
1139 : }
1140 : }
1141 :
1142 : /*
1143 : * Identify the restriction clauses that can match the index.
1144 : */
1145 995588 : MemSet(&clauseset, 0, sizeof(clauseset));
1146 29282 : 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 29282 : if (!clauseset.nonempty && !useful_predicate)
1153 26286 : continue;
1154 :
1155 : /*
1156 : * Add "other" restriction clauses to the clauseset.
1157 : */
1158 2996 : match_clauses_to_index(root, other_clauses, index, &clauseset);
1159 :
1160 : /*
1161 : * Construct paths if possible.
1162 : */
1163 2996 : indexpaths = build_index_paths(root, rel,
1164 : index, &clauseset,
1165 : useful_predicate,
1166 : ST_BITMAPSCAN,
1167 : NULL);
1168 2996 : result = list_concat(result, indexpaths);
1169 : }
1170 :
1171 11894 : 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 : */
1179 : typedef 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 : */
1198 : static int
1199 7964 : or_arg_index_match_cmp(const void *a, const void *b)
1200 : {
1201 7964 : const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1202 7964 : const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1203 :
1204 7964 : if (match_a->indexnum < match_b->indexnum)
1205 1514 : return -1;
1206 6450 : else if (match_a->indexnum > match_b->indexnum)
1207 3376 : return 1;
1208 :
1209 3074 : if (match_a->colnum < match_b->colnum)
1210 1058 : return -1;
1211 2016 : else if (match_a->colnum > match_b->colnum)
1212 24 : return 1;
1213 :
1214 1992 : if (match_a->opno < match_b->opno)
1215 18 : return -1;
1216 1974 : else if (match_a->opno > match_b->opno)
1217 42 : return 1;
1218 :
1219 1932 : if (match_a->inputcollid < match_b->inputcollid)
1220 0 : return -1;
1221 1932 : else if (match_a->inputcollid > match_b->inputcollid)
1222 0 : return 1;
1223 :
1224 1932 : if (match_a->argindex < match_b->argindex)
1225 1854 : return -1;
1226 78 : else if (match_a->argindex > match_b->argindex)
1227 78 : return 1;
1228 :
1229 0 : 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 : */
1236 : static int
1237 8066 : or_arg_index_match_cmp_group(const void *a, const void *b)
1238 : {
1239 8066 : const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1240 8066 : const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1241 :
1242 8066 : if (match_a->groupindex < match_b->groupindex)
1243 4048 : return -1;
1244 4018 : else if (match_a->groupindex > match_b->groupindex)
1245 3574 : return 1;
1246 :
1247 444 : if (match_a->argindex < match_b->argindex)
1248 444 : return -1;
1249 0 : else if (match_a->argindex > match_b->argindex)
1250 0 : return 1;
1251 :
1252 0 : 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 : */
1269 : static List *
1270 10198 : group_similar_or_args(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *rinfo)
1271 : {
1272 : int n;
1273 : int i;
1274 : int group_start;
1275 : OrArgIndexMatch *matches;
1276 10198 : bool matched = false;
1277 : ListCell *lc;
1278 : ListCell *lc2;
1279 : List *orargs;
1280 10198 : List *result = NIL;
1281 10198 : Index relid = rel->relid;
1282 :
1283 : Assert(IsA(rinfo->orclause, BoolExpr));
1284 10198 : orargs = ((BoolExpr *) rinfo->orclause)->args;
1285 10198 : 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 10198 : i = -1;
1293 10198 : matches = (OrArgIndexMatch *) palloc(sizeof(OrArgIndexMatch) * n);
1294 34096 : foreach(lc, orargs)
1295 : {
1296 23898 : 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 23898 : i++;
1307 23898 : matches[i].argindex = i;
1308 23898 : matches[i].groupindex = i;
1309 23898 : matches[i].indexnum = -1;
1310 23898 : matches[i].colnum = -1;
1311 23898 : matches[i].opno = InvalidOid;
1312 23898 : matches[i].inputcollid = InvalidOid;
1313 :
1314 23898 : if (!IsA(arg, RestrictInfo))
1315 2336 : continue;
1316 :
1317 21562 : argrinfo = castNode(RestrictInfo, arg);
1318 :
1319 : /* Only operator clauses can match */
1320 21562 : if (!IsA(argrinfo->clause, OpExpr))
1321 8830 : continue;
1322 :
1323 12732 : clause = (OpExpr *) argrinfo->clause;
1324 12732 : opno = clause->opno;
1325 :
1326 : /* Only binary operators can match */
1327 12732 : if (list_length(clause->args) != 2)
1328 0 : 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 12732 : leftop = get_leftop(clause);
1337 12732 : if (IsA(leftop, RelabelType))
1338 204 : leftop = (Node *) ((RelabelType *) leftop)->arg;
1339 :
1340 12732 : rightop = get_rightop(clause);
1341 12732 : if (IsA(rightop, RelabelType))
1342 992 : 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 12732 : if (bms_is_member(relid, argrinfo->right_relids) &&
1352 2342 : !bms_is_member(relid, argrinfo->left_relids) &&
1353 2270 : !contain_volatile_functions(leftop))
1354 : {
1355 2270 : opno = get_commutator(opno);
1356 :
1357 2270 : if (!OidIsValid(opno))
1358 : {
1359 : /* commutator doesn't exist, we can't reverse the order */
1360 0 : continue;
1361 : }
1362 2270 : nonConstExpr = rightop;
1363 : }
1364 10462 : else if (bms_is_member(relid, argrinfo->left_relids) &&
1365 8264 : !bms_is_member(relid, argrinfo->right_relids) &&
1366 8192 : !contain_volatile_functions(rightop))
1367 : {
1368 8192 : nonConstExpr = leftop;
1369 : }
1370 : else
1371 : {
1372 2270 : 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 10462 : indexnum = 0;
1383 22538 : foreach(lc2, rel->indexlist)
1384 : {
1385 18478 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc2);
1386 :
1387 : /*
1388 : * Ignore index if it doesn't support bitmap scans or SAOP
1389 : * clauses.
1390 : */
1391 18478 : if (!index->amhasgetbitmap || !index->amsearcharray)
1392 54 : continue;
1393 :
1394 41752 : for (colnum = 0; colnum < index->nkeycolumns; colnum++)
1395 : {
1396 29730 : if (match_index_to_operand(nonConstExpr, colnum, index))
1397 : {
1398 6402 : matches[i].indexnum = indexnum;
1399 6402 : matches[i].colnum = colnum;
1400 6402 : matches[i].opno = opno;
1401 6402 : matches[i].inputcollid = clause->inputcollid;
1402 6402 : matched = true;
1403 6402 : break;
1404 : }
1405 : }
1406 :
1407 : /*
1408 : * Stop looping through the indexes, if we managed to match
1409 : * nonConstExpr to any index column.
1410 : */
1411 18424 : if (matches[i].indexnum >= 0)
1412 6402 : break;
1413 12022 : 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 10198 : if (!matched)
1422 : {
1423 5726 : pfree(matches);
1424 5726 : 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 4472 : qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp);
1439 :
1440 : /* Assign groupindex to the sorted clauses */
1441 10690 : 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 6218 : if (matches[i].indexnum == matches[i - 1].indexnum &&
1451 2912 : matches[i].colnum == matches[i - 1].colnum &&
1452 1842 : matches[i].opno == matches[i - 1].opno &&
1453 1794 : matches[i].inputcollid == matches[i - 1].inputcollid &&
1454 1794 : matches[i].indexnum != -1)
1455 444 : matches[i].groupindex = matches[i - 1].groupindex;
1456 : }
1457 :
1458 : /* Re-sort clauses first by groupindex then by argindex */
1459 4472 : 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 4472 : group_start = 0;
1466 15162 : for (i = 1; i <= n; i++)
1467 : {
1468 : /* Check if it's a group boundary */
1469 10690 : if (group_start >= 0 &&
1470 6218 : (i == n ||
1471 6218 : matches[i].indexnum != matches[group_start].indexnum ||
1472 2840 : matches[i].colnum != matches[group_start].colnum ||
1473 1788 : matches[i].opno != matches[group_start].opno ||
1474 1746 : matches[i].inputcollid != matches[group_start].inputcollid ||
1475 1746 : matches[i].indexnum == -1))
1476 : {
1477 : /*
1478 : * One clause in group: add it "as is" to the upper-level OR.
1479 : */
1480 10246 : if (i - group_start == 1)
1481 : {
1482 9934 : result = lappend(result,
1483 : list_nth(orargs,
1484 9934 : matches[group_start].argindex));
1485 : }
1486 : else
1487 : {
1488 : /*
1489 : * Two or more clauses in a group: create a nested OR.
1490 : */
1491 312 : List *args = NIL;
1492 312 : 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 1068 : for (j = group_start; j < i; j++)
1500 : {
1501 756 : Node *arg = list_nth(orargs, matches[j].argindex);
1502 :
1503 756 : rargs = lappend(rargs, arg);
1504 756 : if (IsA(arg, RestrictInfo))
1505 756 : args = lappend(args, ((RestrictInfo *) arg)->clause);
1506 : else
1507 0 : args = lappend(args, arg);
1508 : }
1509 :
1510 : /* Construct the nested OR and wrap it with RestrictInfo */
1511 312 : subrinfo = make_plain_restrictinfo(root,
1512 : make_orclause(args),
1513 : make_orclause(rargs),
1514 312 : rinfo->is_pushed_down,
1515 312 : rinfo->has_clone,
1516 312 : rinfo->is_clone,
1517 312 : rinfo->pseudoconstant,
1518 : rinfo->security_level,
1519 : rinfo->required_relids,
1520 : rinfo->incompatible_relids,
1521 : rinfo->outer_relids);
1522 312 : result = lappend(result, subrinfo);
1523 : }
1524 :
1525 10246 : group_start = i;
1526 : }
1527 : }
1528 4472 : pfree(matches);
1529 4472 : 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 : */
1546 : static List *
1547 306 : make_bitmap_paths_for_or_group(PlannerInfo *root, RelOptInfo *rel,
1548 : RestrictInfo *ri, List *other_clauses)
1549 : {
1550 306 : List *jointlist = NIL;
1551 306 : List *splitlist = NIL;
1552 : ListCell *lc;
1553 : List *orargs;
1554 306 : List *args = ((BoolExpr *) ri->orclause)->args;
1555 306 : Cost jointcost = 0.0,
1556 306 : 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 306 : orargs = list_make1(ri);
1564 306 : indlist = build_paths_for_OR(root, rel,
1565 : orargs,
1566 : other_clauses);
1567 306 : if (indlist != NIL)
1568 : {
1569 300 : bitmapqual = choose_bitmap_and(root, rel, indlist);
1570 300 : jointcost = bitmapqual->total_cost;
1571 300 : 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 306 : if (jointlist != NIL && other_clauses == NIL)
1581 84 : return jointlist;
1582 :
1583 : /*
1584 : * Also try to match all containing clauses one-by-one.
1585 : */
1586 768 : foreach(lc, args)
1587 : {
1588 552 : orargs = list_make1(lfirst(lc));
1589 :
1590 552 : indlist = build_paths_for_OR(root, rel,
1591 : orargs,
1592 : other_clauses);
1593 :
1594 552 : if (indlist == NIL)
1595 : {
1596 6 : splitlist = NIL;
1597 6 : break;
1598 : }
1599 :
1600 546 : bitmapqual = choose_bitmap_and(root, rel, indlist);
1601 546 : splitcost += bitmapqual->total_cost;
1602 546 : splitlist = lappend(splitlist, bitmapqual);
1603 : }
1604 :
1605 : /*
1606 : * Pick the best option.
1607 : */
1608 222 : if (splitlist == NIL)
1609 6 : return jointlist;
1610 216 : else if (jointlist == NIL)
1611 0 : return splitlist;
1612 : else
1613 216 : 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 : */
1627 : static List *
1628 672326 : generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
1629 : List *clauses, List *other_clauses)
1630 : {
1631 672326 : 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 672326 : all_clauses = list_concat_copy(clauses, other_clauses);
1640 :
1641 1051810 : foreach(lc, clauses)
1642 : {
1643 379484 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1644 : List *pathlist;
1645 : Path *bitmapqual;
1646 : ListCell *j;
1647 : List *groupedArgs;
1648 379484 : List *inner_other_clauses = NIL;
1649 :
1650 : /* Ignore RestrictInfos that aren't ORs */
1651 379484 : if (!restriction_is_or_clause(rinfo))
1652 369286 : 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 10198 : 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 10198 : groupedArgs = group_similar_or_args(root, rel, rinfo);
1666 :
1667 10198 : 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 4472 : inner_other_clauses = list_delete(list_copy(all_clauses), rinfo);
1679 : }
1680 :
1681 12318 : foreach(j, groupedArgs)
1682 : {
1683 11342 : Node *orarg = (Node *) lfirst(j);
1684 : List *indlist;
1685 :
1686 : /* OR arguments should be ANDs or sub-RestrictInfos */
1687 11342 : if (is_andclause(orarg))
1688 : {
1689 1430 : List *andargs = ((BoolExpr *) orarg)->args;
1690 :
1691 1430 : indlist = build_paths_for_OR(root, rel,
1692 : andargs,
1693 : all_clauses);
1694 :
1695 : /* Recurse in case there are sub-ORs */
1696 1430 : indlist = list_concat(indlist,
1697 1430 : generate_bitmap_or_paths(root, rel,
1698 : andargs,
1699 : all_clauses));
1700 : }
1701 9912 : else if (restriction_is_or_clause(castNode(RestrictInfo, orarg)))
1702 : {
1703 306 : RestrictInfo *ri = castNode(RestrictInfo, orarg);
1704 :
1705 : /*
1706 : * Generate bitmap paths for the group of similar OR-clause
1707 : * arguments.
1708 : */
1709 306 : indlist = make_bitmap_paths_for_or_group(root,
1710 : rel, ri,
1711 : inner_other_clauses);
1712 :
1713 306 : if (indlist == NIL)
1714 : {
1715 6 : pathlist = NIL;
1716 6 : break;
1717 : }
1718 : else
1719 : {
1720 300 : pathlist = list_concat(pathlist, indlist);
1721 300 : continue;
1722 : }
1723 : }
1724 : else
1725 : {
1726 9606 : RestrictInfo *ri = castNode(RestrictInfo, orarg);
1727 : List *orargs;
1728 :
1729 9606 : orargs = list_make1(ri);
1730 :
1731 9606 : 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 11036 : if (indlist == NIL)
1741 : {
1742 9216 : pathlist = NIL;
1743 9216 : break;
1744 : }
1745 :
1746 : /*
1747 : * OK, pick the most promising AND combination, and add it to
1748 : * pathlist.
1749 : */
1750 1820 : bitmapqual = choose_bitmap_and(root, rel, indlist);
1751 1820 : pathlist = lappend(pathlist, bitmapqual);
1752 : }
1753 :
1754 10198 : if (inner_other_clauses != NIL)
1755 2554 : 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 10198 : if (pathlist != NIL)
1762 : {
1763 976 : bitmapqual = (Path *) create_bitmap_or_path(root, rel, pathlist);
1764 976 : result = lappend(result, bitmapqual);
1765 : }
1766 : }
1767 :
1768 672326 : 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 : */
1783 : static Path *
1784 342710 : choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
1785 : {
1786 342710 : int npaths = list_length(paths);
1787 : PathClauseUsage **pathinfoarray;
1788 : PathClauseUsage *pathinfo;
1789 : List *clauselist;
1790 342710 : List *bestpaths = NIL;
1791 342710 : Cost bestcost = 0;
1792 : int i,
1793 : j;
1794 : ListCell *l;
1795 :
1796 : Assert(npaths > 0); /* else caller error */
1797 342710 : if (npaths == 1)
1798 263230 : return (Path *) linitial(paths); /* easy case */
1799 :
1800 : /*
1801 : * In theory we should consider every nonempty subset of the given paths.
1802 : * In practice that seems like overkill, given the crude nature of the
1803 : * estimates, not to mention the possible effects of higher-level AND and
1804 : * OR clauses. Moreover, it's completely impractical if there are a large
1805 : * number of paths, since the work would grow as O(2^N).
1806 : *
1807 : * As a heuristic, we first check for paths using exactly the same sets of
1808 : * WHERE clauses + index predicate conditions, and reject all but the
1809 : * cheapest-to-scan in any such group. This primarily gets rid of indexes
1810 : * that include the interesting columns but also irrelevant columns. (In
1811 : * situations where the DBA has gone overboard on creating variant
1812 : * indexes, this can make for a very large reduction in the number of
1813 : * paths considered further.)
1814 : *
1815 : * We then sort the surviving paths with the cheapest-to-scan first, and
1816 : * for each path, consider using that path alone as the basis for a bitmap
1817 : * scan. Then we consider bitmap AND scans formed from that path plus
1818 : * each subsequent (higher-cost) path, adding on a subsequent path if it
1819 : * results in a reduction in the estimated total scan cost. This means we
1820 : * consider about O(N^2) rather than O(2^N) path combinations, which is
1821 : * quite tolerable, especially given than N is usually reasonably small
1822 : * because of the prefiltering step. The cheapest of these is returned.
1823 : *
1824 : * We will only consider AND combinations in which no two indexes use the
1825 : * same WHERE clause. This is a bit of a kluge: it's needed because
1826 : * costsize.c and clausesel.c aren't very smart about redundant clauses.
1827 : * They will usually double-count the redundant clauses, producing a
1828 : * too-small selectivity that makes a redundant AND step look like it
1829 : * reduces the total cost. Perhaps someday that code will be smarter and
1830 : * we can remove this limitation. (But note that this also defends
1831 : * against flat-out duplicate input paths, which can happen because
1832 : * match_join_clauses_to_index will find the same OR join clauses that
1833 : * extract_restriction_or_clauses has pulled OR restriction clauses out
1834 : * of.)
1835 : *
1836 : * For the same reason, we reject AND combinations in which an index
1837 : * predicate clause duplicates another clause. Here we find it necessary
1838 : * to be even stricter: we'll reject a partial index if any of its
1839 : * predicate clauses are implied by the set of WHERE clauses and predicate
1840 : * clauses used so far. This covers cases such as a condition "x = 42"
1841 : * used with a plain index, followed by a clauseless scan of a partial
1842 : * index "WHERE x >= 40 AND x < 50". The partial index has been accepted
1843 : * only because "x = 42" was present, and so allowing it would partially
1844 : * double-count selectivity. (We could use predicate_implied_by on
1845 : * regular qual clauses too, to have a more intelligent, but much more
1846 : * expensive, check for redundancy --- but in most cases simple equality
1847 : * seems to suffice.)
1848 : */
1849 :
1850 : /*
1851 : * Extract clause usage info and detect any paths that use exactly the
1852 : * same set of clauses; keep only the cheapest-to-scan of any such groups.
1853 : * The surviving paths are put into an array for qsort'ing.
1854 : */
1855 : pathinfoarray = (PathClauseUsage **)
1856 79480 : palloc(npaths * sizeof(PathClauseUsage *));
1857 79480 : clauselist = NIL;
1858 79480 : npaths = 0;
1859 261874 : foreach(l, paths)
1860 : {
1861 182394 : Path *ipath = (Path *) lfirst(l);
1862 :
1863 182394 : pathinfo = classify_index_clause_usage(ipath, &clauselist);
1864 :
1865 : /* If it's unclassifiable, treat it as distinct from all others */
1866 182394 : if (pathinfo->unclassifiable)
1867 : {
1868 0 : pathinfoarray[npaths++] = pathinfo;
1869 0 : continue;
1870 : }
1871 :
1872 284982 : for (i = 0; i < npaths; i++)
1873 : {
1874 252656 : if (!pathinfoarray[i]->unclassifiable &&
1875 126328 : bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
1876 23740 : break;
1877 : }
1878 182394 : if (i < npaths)
1879 : {
1880 : /* duplicate clauseids, keep the cheaper one */
1881 : Cost ncost;
1882 : Cost ocost;
1883 : Selectivity nselec;
1884 : Selectivity oselec;
1885 :
1886 23740 : cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
1887 23740 : cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
1888 23740 : if (ncost < ocost)
1889 5286 : pathinfoarray[i] = pathinfo;
1890 : }
1891 : else
1892 : {
1893 : /* not duplicate clauseids, add to array */
1894 158654 : pathinfoarray[npaths++] = pathinfo;
1895 : }
1896 : }
1897 :
1898 : /* If only one surviving path, we're done */
1899 79480 : if (npaths == 1)
1900 15028 : return pathinfoarray[0]->path;
1901 :
1902 : /* Sort the surviving paths by index access cost */
1903 64452 : qsort(pathinfoarray, npaths, sizeof(PathClauseUsage *),
1904 : path_usage_comparator);
1905 :
1906 : /*
1907 : * For each surviving index, consider it as an "AND group leader", and see
1908 : * whether adding on any of the later indexes results in an AND path with
1909 : * cheaper total cost than before. Then take the cheapest AND group.
1910 : *
1911 : * Note: paths that are either clauseless or unclassifiable will have
1912 : * empty clauseids, so that they will not be rejected by the clauseids
1913 : * filter here, nor will they cause later paths to be rejected by it.
1914 : */
1915 208078 : for (i = 0; i < npaths; i++)
1916 : {
1917 : Cost costsofar;
1918 : List *qualsofar;
1919 : Bitmapset *clauseidsofar;
1920 :
1921 143626 : pathinfo = pathinfoarray[i];
1922 143626 : paths = list_make1(pathinfo->path);
1923 143626 : costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
1924 143626 : qualsofar = list_concat_copy(pathinfo->quals, pathinfo->preds);
1925 143626 : clauseidsofar = bms_copy(pathinfo->clauseids);
1926 :
1927 237960 : for (j = i + 1; j < npaths; j++)
1928 : {
1929 : Cost newcost;
1930 :
1931 94334 : pathinfo = pathinfoarray[j];
1932 : /* Check for redundancy */
1933 94334 : if (bms_overlap(pathinfo->clauseids, clauseidsofar))
1934 42594 : continue; /* consider it redundant */
1935 51740 : if (pathinfo->preds)
1936 : {
1937 24 : bool redundant = false;
1938 :
1939 : /* we check each predicate clause separately */
1940 24 : foreach(l, pathinfo->preds)
1941 : {
1942 24 : Node *np = (Node *) lfirst(l);
1943 :
1944 24 : if (predicate_implied_by(list_make1(np), qualsofar, false))
1945 : {
1946 24 : redundant = true;
1947 24 : break; /* out of inner foreach loop */
1948 : }
1949 : }
1950 24 : if (redundant)
1951 24 : continue;
1952 : }
1953 : /* tentatively add new path to paths, so we can estimate cost */
1954 51716 : paths = lappend(paths, pathinfo->path);
1955 51716 : newcost = bitmap_and_cost_est(root, rel, paths);
1956 51716 : if (newcost < costsofar)
1957 : {
1958 : /* keep new path in paths, update subsidiary variables */
1959 272 : costsofar = newcost;
1960 272 : qualsofar = list_concat(qualsofar, pathinfo->quals);
1961 272 : qualsofar = list_concat(qualsofar, pathinfo->preds);
1962 272 : clauseidsofar = bms_add_members(clauseidsofar,
1963 272 : pathinfo->clauseids);
1964 : }
1965 : else
1966 : {
1967 : /* reject new path, remove it from paths list */
1968 51444 : paths = list_truncate(paths, list_length(paths) - 1);
1969 : }
1970 : }
1971 :
1972 : /* Keep the cheapest AND-group (or singleton) */
1973 143626 : if (i == 0 || costsofar < bestcost)
1974 : {
1975 67650 : bestpaths = paths;
1976 67650 : bestcost = costsofar;
1977 : }
1978 :
1979 : /* some easy cleanup (we don't try real hard though) */
1980 143626 : list_free(qualsofar);
1981 : }
1982 :
1983 64452 : if (list_length(bestpaths) == 1)
1984 64204 : return (Path *) linitial(bestpaths); /* no need for AND */
1985 248 : return (Path *) create_bitmap_and_path(root, rel, bestpaths);
1986 : }
1987 :
1988 : /* qsort comparator to sort in increasing index access cost order */
1989 : static int
1990 89130 : path_usage_comparator(const void *a, const void *b)
1991 : {
1992 89130 : PathClauseUsage *pa = *(PathClauseUsage *const *) a;
1993 89130 : PathClauseUsage *pb = *(PathClauseUsage *const *) b;
1994 : Cost acost;
1995 : Cost bcost;
1996 : Selectivity aselec;
1997 : Selectivity bselec;
1998 :
1999 89130 : cost_bitmap_tree_node(pa->path, &acost, &aselec);
2000 89130 : cost_bitmap_tree_node(pb->path, &bcost, &bselec);
2001 :
2002 : /*
2003 : * If costs are the same, sort by selectivity.
2004 : */
2005 89130 : if (acost < bcost)
2006 52520 : return -1;
2007 36610 : if (acost > bcost)
2008 24976 : return 1;
2009 :
2010 11634 : if (aselec < bselec)
2011 4266 : return -1;
2012 7368 : if (aselec > bselec)
2013 2996 : return 1;
2014 :
2015 4372 : return 0;
2016 : }
2017 :
2018 : /*
2019 : * Estimate the cost of actually executing a bitmap scan with a single
2020 : * index path (which could be a BitmapAnd or BitmapOr node).
2021 : */
2022 : static Cost
2023 195342 : bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
2024 : {
2025 : BitmapHeapPath bpath;
2026 :
2027 : /* Set up a dummy BitmapHeapPath */
2028 195342 : bpath.path.type = T_BitmapHeapPath;
2029 195342 : bpath.path.pathtype = T_BitmapHeapScan;
2030 195342 : bpath.path.parent = rel;
2031 195342 : bpath.path.pathtarget = rel->reltarget;
2032 195342 : bpath.path.param_info = ipath->param_info;
2033 195342 : bpath.path.pathkeys = NIL;
2034 195342 : bpath.bitmapqual = ipath;
2035 :
2036 : /*
2037 : * Check the cost of temporary path without considering parallelism.
2038 : * Parallel bitmap heap path will be considered at later stage.
2039 : */
2040 195342 : bpath.path.parallel_workers = 0;
2041 :
2042 : /* Now we can do cost_bitmap_heap_scan */
2043 195342 : cost_bitmap_heap_scan(&bpath.path, root, rel,
2044 : bpath.path.param_info,
2045 : ipath,
2046 : get_loop_count(root, rel->relid,
2047 195342 : PATH_REQ_OUTER(ipath)));
2048 :
2049 195342 : return bpath.path.total_cost;
2050 : }
2051 :
2052 : /*
2053 : * Estimate the cost of actually executing a BitmapAnd scan with the given
2054 : * inputs.
2055 : */
2056 : static Cost
2057 51716 : bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
2058 : {
2059 : BitmapAndPath *apath;
2060 :
2061 : /*
2062 : * Might as well build a real BitmapAndPath here, as the work is slightly
2063 : * too complicated to be worth repeating just to save one palloc.
2064 : */
2065 51716 : apath = create_bitmap_and_path(root, rel, paths);
2066 :
2067 51716 : return bitmap_scan_cost_est(root, rel, (Path *) apath);
2068 : }
2069 :
2070 :
2071 : /*
2072 : * classify_index_clause_usage
2073 : * Construct a PathClauseUsage struct describing the WHERE clauses and
2074 : * index predicate clauses used by the given indexscan path.
2075 : * We consider two clauses the same if they are equal().
2076 : *
2077 : * At some point we might want to migrate this info into the Path data
2078 : * structure proper, but for the moment it's only needed within
2079 : * choose_bitmap_and().
2080 : *
2081 : * *clauselist is used and expanded as needed to identify all the distinct
2082 : * clauses seen across successive calls. Caller must initialize it to NIL
2083 : * before first call of a set.
2084 : */
2085 : static PathClauseUsage *
2086 182394 : classify_index_clause_usage(Path *path, List **clauselist)
2087 : {
2088 : PathClauseUsage *result;
2089 : Bitmapset *clauseids;
2090 : ListCell *lc;
2091 :
2092 182394 : result = (PathClauseUsage *) palloc(sizeof(PathClauseUsage));
2093 182394 : result->path = path;
2094 :
2095 : /* Recursively find the quals and preds used by the path */
2096 182394 : result->quals = NIL;
2097 182394 : result->preds = NIL;
2098 182394 : find_indexpath_quals(path, &result->quals, &result->preds);
2099 :
2100 : /*
2101 : * Some machine-generated queries have outlandish numbers of qual clauses.
2102 : * To avoid getting into O(N^2) behavior even in this preliminary
2103 : * classification step, we want to limit the number of entries we can
2104 : * accumulate in *clauselist. Treat any path with more than 100 quals +
2105 : * preds as unclassifiable, which will cause calling code to consider it
2106 : * distinct from all other paths.
2107 : */
2108 182394 : if (list_length(result->quals) + list_length(result->preds) > 100)
2109 : {
2110 0 : result->clauseids = NULL;
2111 0 : result->unclassifiable = true;
2112 0 : return result;
2113 : }
2114 :
2115 : /* Build up a bitmapset representing the quals and preds */
2116 182394 : clauseids = NULL;
2117 418028 : foreach(lc, result->quals)
2118 : {
2119 235634 : Node *node = (Node *) lfirst(lc);
2120 :
2121 235634 : clauseids = bms_add_member(clauseids,
2122 : find_list_position(node, clauselist));
2123 : }
2124 182688 : foreach(lc, result->preds)
2125 : {
2126 294 : Node *node = (Node *) lfirst(lc);
2127 :
2128 294 : clauseids = bms_add_member(clauseids,
2129 : find_list_position(node, clauselist));
2130 : }
2131 182394 : result->clauseids = clauseids;
2132 182394 : result->unclassifiable = false;
2133 :
2134 182394 : return result;
2135 : }
2136 :
2137 :
2138 : /*
2139 : * find_indexpath_quals
2140 : *
2141 : * Given the Path structure for a plain or bitmap indexscan, extract lists
2142 : * of all the index clauses and index predicate conditions used in the Path.
2143 : * These are appended to the initial contents of *quals and *preds (hence
2144 : * caller should initialize those to NIL).
2145 : *
2146 : * Note we are not trying to produce an accurate representation of the AND/OR
2147 : * semantics of the Path, but just find out all the base conditions used.
2148 : *
2149 : * The result lists contain pointers to the expressions used in the Path,
2150 : * but all the list cells are freshly built, so it's safe to destructively
2151 : * modify the lists (eg, by concat'ing with other lists).
2152 : */
2153 : static void
2154 184512 : find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
2155 : {
2156 184512 : if (IsA(bitmapqual, BitmapAndPath))
2157 : {
2158 0 : BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
2159 : ListCell *l;
2160 :
2161 0 : foreach(l, apath->bitmapquals)
2162 : {
2163 0 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
2164 : }
2165 : }
2166 184512 : else if (IsA(bitmapqual, BitmapOrPath))
2167 : {
2168 1158 : BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
2169 : ListCell *l;
2170 :
2171 3276 : foreach(l, opath->bitmapquals)
2172 : {
2173 2118 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
2174 : }
2175 : }
2176 183354 : else if (IsA(bitmapqual, IndexPath))
2177 : {
2178 183354 : IndexPath *ipath = (IndexPath *) bitmapqual;
2179 : ListCell *l;
2180 :
2181 418988 : foreach(l, ipath->indexclauses)
2182 : {
2183 235634 : IndexClause *iclause = (IndexClause *) lfirst(l);
2184 :
2185 235634 : *quals = lappend(*quals, iclause->rinfo->clause);
2186 : }
2187 183354 : *preds = list_concat(*preds, ipath->indexinfo->indpred);
2188 : }
2189 : else
2190 0 : elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
2191 184512 : }
2192 :
2193 :
2194 : /*
2195 : * find_list_position
2196 : * Return the given node's position (counting from 0) in the given
2197 : * list of nodes. If it's not equal() to any existing list member,
2198 : * add it at the end, and return that position.
2199 : */
2200 : static int
2201 235928 : find_list_position(Node *node, List **nodelist)
2202 : {
2203 : int i;
2204 : ListCell *lc;
2205 :
2206 235928 : i = 0;
2207 372610 : foreach(lc, *nodelist)
2208 : {
2209 206420 : Node *oldnode = (Node *) lfirst(lc);
2210 :
2211 206420 : if (equal(node, oldnode))
2212 69738 : return i;
2213 136682 : i++;
2214 : }
2215 :
2216 166190 : *nodelist = lappend(*nodelist, node);
2217 :
2218 166190 : return i;
2219 : }
2220 :
2221 :
2222 : /*
2223 : * check_index_only
2224 : * Determine whether an index-only scan is possible for this index.
2225 : */
2226 : static bool
2227 868858 : check_index_only(RelOptInfo *rel, IndexOptInfo *index)
2228 : {
2229 : bool result;
2230 868858 : Bitmapset *attrs_used = NULL;
2231 868858 : Bitmapset *index_canreturn_attrs = NULL;
2232 : ListCell *lc;
2233 : int i;
2234 :
2235 : /* Index-only scans must be enabled */
2236 868858 : if (!enable_indexonlyscan)
2237 3688 : return false;
2238 :
2239 : /*
2240 : * Check that all needed attributes of the relation are available from the
2241 : * index.
2242 : */
2243 :
2244 : /*
2245 : * First, identify all the attributes needed for joins or final output.
2246 : * Note: we must look at rel's targetlist, not the attr_needed data,
2247 : * because attr_needed isn't computed for inheritance child rels.
2248 : */
2249 865170 : pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
2250 :
2251 : /*
2252 : * Add all the attributes used by restriction clauses; but consider only
2253 : * those clauses not implied by the index predicate, since ones that are
2254 : * so implied don't need to be checked explicitly in the plan.
2255 : *
2256 : * Note: attributes used only in index quals would not be needed at
2257 : * runtime either, if we are certain that the index is not lossy. However
2258 : * it'd be complicated to account for that accurately, and it doesn't
2259 : * matter in most cases, since we'd conclude that such attributes are
2260 : * available from the index anyway.
2261 : */
2262 1810630 : foreach(lc, index->indrestrictinfo)
2263 : {
2264 945460 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2265 :
2266 945460 : pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
2267 : }
2268 :
2269 : /*
2270 : * Construct a bitmapset of columns that the index can return back in an
2271 : * index-only scan.
2272 : */
2273 2461482 : for (i = 0; i < index->ncolumns; i++)
2274 : {
2275 1596312 : int attno = index->indexkeys[i];
2276 :
2277 : /*
2278 : * For the moment, we just ignore index expressions. It might be nice
2279 : * to do something with them, later.
2280 : */
2281 1596312 : if (attno == 0)
2282 3286 : continue;
2283 :
2284 1593026 : if (index->canreturn[i])
2285 : index_canreturn_attrs =
2286 1317892 : bms_add_member(index_canreturn_attrs,
2287 : attno - FirstLowInvalidHeapAttributeNumber);
2288 : }
2289 :
2290 : /* Do we have all the necessary attributes? */
2291 865170 : result = bms_is_subset(attrs_used, index_canreturn_attrs);
2292 :
2293 865170 : bms_free(attrs_used);
2294 865170 : bms_free(index_canreturn_attrs);
2295 :
2296 865170 : return result;
2297 : }
2298 :
2299 : /*
2300 : * get_loop_count
2301 : * Choose the loop count estimate to use for costing a parameterized path
2302 : * with the given set of outer relids.
2303 : *
2304 : * Since we produce parameterized paths before we've begun to generate join
2305 : * relations, it's impossible to predict exactly how many times a parameterized
2306 : * path will be iterated; we don't know the size of the relation that will be
2307 : * on the outside of the nestloop. However, we should try to account for
2308 : * multiple iterations somehow in costing the path. The heuristic embodied
2309 : * here is to use the rowcount of the smallest other base relation needed in
2310 : * the join clauses used by the path. (We could alternatively consider the
2311 : * largest one, but that seems too optimistic.) This is of course the right
2312 : * answer for single-other-relation cases, and it seems like a reasonable
2313 : * zero-order approximation for multiway-join cases.
2314 : *
2315 : * In addition, we check to see if the other side of each join clause is on
2316 : * the inside of some semijoin that the current relation is on the outside of.
2317 : * If so, the only way that a parameterized path could be used is if the
2318 : * semijoin RHS has been unique-ified, so we should use the number of unique
2319 : * RHS rows rather than using the relation's raw rowcount.
2320 : *
2321 : * Note: for this to work, allpaths.c must establish all baserel size
2322 : * estimates before it begins to compute paths, or at least before it
2323 : * calls create_index_paths().
2324 : */
2325 : static double
2326 1205258 : get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
2327 : {
2328 : double result;
2329 : int outer_relid;
2330 :
2331 : /* For a non-parameterized path, just return 1.0 quickly */
2332 1205258 : if (outer_relids == NULL)
2333 834398 : return 1.0;
2334 :
2335 370860 : result = 0.0;
2336 370860 : outer_relid = -1;
2337 752648 : while ((outer_relid = bms_next_member(outer_relids, outer_relid)) >= 0)
2338 : {
2339 : RelOptInfo *outer_rel;
2340 : double rowcount;
2341 :
2342 : /* Paranoia: ignore bogus relid indexes */
2343 381788 : if (outer_relid >= root->simple_rel_array_size)
2344 0 : continue;
2345 381788 : outer_rel = root->simple_rel_array[outer_relid];
2346 381788 : if (outer_rel == NULL)
2347 254 : continue;
2348 : Assert(outer_rel->relid == outer_relid); /* sanity check on array */
2349 :
2350 : /* Other relation could be proven empty, if so ignore */
2351 381534 : if (IS_DUMMY_REL(outer_rel))
2352 24 : continue;
2353 :
2354 : /* Otherwise, rel's rows estimate should be valid by now */
2355 : Assert(outer_rel->rows > 0);
2356 :
2357 : /* Check to see if rel is on the inside of any semijoins */
2358 381510 : rowcount = adjust_rowcount_for_semijoins(root,
2359 : cur_relid,
2360 : outer_relid,
2361 : outer_rel->rows);
2362 :
2363 : /* Remember smallest row count estimate among the outer rels */
2364 381510 : if (result == 0.0 || result > rowcount)
2365 377208 : result = rowcount;
2366 : }
2367 : /* Return 1.0 if we found no valid relations (shouldn't happen) */
2368 370860 : return (result > 0.0) ? result : 1.0;
2369 : }
2370 :
2371 : /*
2372 : * Check to see if outer_relid is on the inside of any semijoin that cur_relid
2373 : * is on the outside of. If so, replace rowcount with the estimated number of
2374 : * unique rows from the semijoin RHS (assuming that's smaller, which it might
2375 : * not be). The estimate is crude but it's the best we can do at this stage
2376 : * of the proceedings.
2377 : */
2378 : static double
2379 381510 : adjust_rowcount_for_semijoins(PlannerInfo *root,
2380 : Index cur_relid,
2381 : Index outer_relid,
2382 : double rowcount)
2383 : {
2384 : ListCell *lc;
2385 :
2386 613278 : foreach(lc, root->join_info_list)
2387 : {
2388 231768 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
2389 :
2390 239116 : if (sjinfo->jointype == JOIN_SEMI &&
2391 10530 : bms_is_member(cur_relid, sjinfo->syn_lefthand) &&
2392 3182 : bms_is_member(outer_relid, sjinfo->syn_righthand))
2393 : {
2394 : /* Estimate number of unique-ified rows */
2395 : double nraw;
2396 : double nunique;
2397 :
2398 1140 : nraw = approximate_joinrel_size(root, sjinfo->syn_righthand);
2399 1140 : nunique = estimate_num_groups(root,
2400 : sjinfo->semi_rhs_exprs,
2401 : nraw,
2402 : NULL,
2403 : NULL);
2404 1140 : if (rowcount > nunique)
2405 386 : rowcount = nunique;
2406 : }
2407 : }
2408 381510 : return rowcount;
2409 : }
2410 :
2411 : /*
2412 : * Make an approximate estimate of the size of a joinrel.
2413 : *
2414 : * We don't have enough info at this point to get a good estimate, so we
2415 : * just multiply the base relation sizes together. Fortunately, this is
2416 : * the right answer anyway for the most common case with a single relation
2417 : * on the RHS of a semijoin. Also, estimate_num_groups() has only a weak
2418 : * dependency on its input_rows argument (it basically uses it as a clamp).
2419 : * So we might be able to get a fairly decent end result even with a severe
2420 : * overestimate of the RHS's raw size.
2421 : */
2422 : static double
2423 1140 : approximate_joinrel_size(PlannerInfo *root, Relids relids)
2424 : {
2425 1140 : double rowcount = 1.0;
2426 : int relid;
2427 :
2428 1140 : relid = -1;
2429 2436 : while ((relid = bms_next_member(relids, relid)) >= 0)
2430 : {
2431 : RelOptInfo *rel;
2432 :
2433 : /* Paranoia: ignore bogus relid indexes */
2434 1296 : if (relid >= root->simple_rel_array_size)
2435 0 : continue;
2436 1296 : rel = root->simple_rel_array[relid];
2437 1296 : if (rel == NULL)
2438 0 : continue;
2439 : Assert(rel->relid == relid); /* sanity check on array */
2440 :
2441 : /* Relation could be proven empty, if so ignore */
2442 1296 : if (IS_DUMMY_REL(rel))
2443 0 : continue;
2444 :
2445 : /* Otherwise, rel's rows estimate should be valid by now */
2446 : Assert(rel->rows > 0);
2447 :
2448 : /* Accumulate product */
2449 1296 : rowcount *= rel->rows;
2450 : }
2451 1140 : return rowcount;
2452 : }
2453 :
2454 :
2455 : /****************************************************************************
2456 : * ---- ROUTINES TO CHECK QUERY CLAUSES ----
2457 : ****************************************************************************/
2458 :
2459 : /*
2460 : * match_restriction_clauses_to_index
2461 : * Identify restriction clauses for the rel that match the index.
2462 : * Matching clauses are added to *clauseset.
2463 : */
2464 : static void
2465 724020 : match_restriction_clauses_to_index(PlannerInfo *root,
2466 : IndexOptInfo *index,
2467 : IndexClauseSet *clauseset)
2468 : {
2469 : /* We can ignore clauses that are implied by the index predicate */
2470 724020 : match_clauses_to_index(root, index->indrestrictinfo, index, clauseset);
2471 724020 : }
2472 :
2473 : /*
2474 : * match_join_clauses_to_index
2475 : * Identify join clauses for the rel that match the index.
2476 : * Matching clauses are added to *clauseset.
2477 : * Also, add any potentially usable join OR clauses to *joinorclauses.
2478 : * They also might be processed by match_clause_to_index() as a whole.
2479 : */
2480 : static void
2481 724020 : match_join_clauses_to_index(PlannerInfo *root,
2482 : RelOptInfo *rel, IndexOptInfo *index,
2483 : IndexClauseSet *clauseset,
2484 : List **joinorclauses)
2485 : {
2486 : ListCell *lc;
2487 :
2488 : /* Scan the rel's join clauses */
2489 981074 : foreach(lc, rel->joininfo)
2490 : {
2491 257054 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2492 :
2493 : /* Check if clause can be moved to this rel */
2494 257054 : if (!join_clause_is_movable_to(rinfo, rel))
2495 151720 : continue;
2496 :
2497 : /*
2498 : * Potentially usable, so see if it matches the index or is an OR. Use
2499 : * list_append_unique_ptr() here to avoid possible duplicates when
2500 : * processing the same clauses with different indexes.
2501 : */
2502 105334 : if (restriction_is_or_clause(rinfo))
2503 15354 : *joinorclauses = list_append_unique_ptr(*joinorclauses, rinfo);
2504 :
2505 105334 : match_clause_to_index(root, rinfo, index, clauseset);
2506 : }
2507 724020 : }
2508 :
2509 : /*
2510 : * match_eclass_clauses_to_index
2511 : * Identify EquivalenceClass join clauses for the rel that match the index.
2512 : * Matching clauses are added to *clauseset.
2513 : */
2514 : static void
2515 724020 : match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index,
2516 : IndexClauseSet *clauseset)
2517 : {
2518 : int indexcol;
2519 :
2520 : /* No work if rel is not in any such ECs */
2521 724020 : if (!index->rel->has_eclass_joins)
2522 426814 : return;
2523 :
2524 779494 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2525 : {
2526 : ec_member_matches_arg arg;
2527 : List *clauses;
2528 :
2529 : /* Generate clauses, skipping any that join to lateral_referencers */
2530 482288 : arg.index = index;
2531 482288 : arg.indexcol = indexcol;
2532 482288 : clauses = generate_implied_equalities_for_column(root,
2533 : index->rel,
2534 : ec_member_matches_indexcol,
2535 : &arg,
2536 482288 : index->rel->lateral_referencers);
2537 :
2538 : /*
2539 : * We have to check whether the results actually do match the index,
2540 : * since for non-btree indexes the EC's equality operators might not
2541 : * be in the index opclass (cf ec_member_matches_indexcol).
2542 : */
2543 482288 : match_clauses_to_index(root, clauses, index, clauseset);
2544 : }
2545 : }
2546 :
2547 : /*
2548 : * match_clauses_to_index
2549 : * Perform match_clause_to_index() for each clause in a list.
2550 : * Matching clauses are added to *clauseset.
2551 : */
2552 : static void
2553 1238586 : match_clauses_to_index(PlannerInfo *root,
2554 : List *clauses,
2555 : IndexOptInfo *index,
2556 : IndexClauseSet *clauseset)
2557 : {
2558 : ListCell *lc;
2559 :
2560 2239600 : foreach(lc, clauses)
2561 : {
2562 1001014 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
2563 :
2564 1001014 : match_clause_to_index(root, rinfo, index, clauseset);
2565 : }
2566 1238586 : }
2567 :
2568 : /*
2569 : * match_clause_to_index
2570 : * Test whether a qual clause can be used with an index.
2571 : *
2572 : * If the clause is usable, add an IndexClause entry for it to the appropriate
2573 : * list in *clauseset. (*clauseset must be initialized to zeroes before first
2574 : * call.)
2575 : *
2576 : * Note: in some circumstances we may find the same RestrictInfos coming from
2577 : * multiple places. Defend against redundant outputs by refusing to add a
2578 : * clause twice (pointer equality should be a good enough check for this).
2579 : *
2580 : * Note: it's possible that a badly-defined index could have multiple matching
2581 : * columns. We always select the first match if so; this avoids scenarios
2582 : * wherein we get an inflated idea of the index's selectivity by using the
2583 : * same clause multiple times with different index columns.
2584 : */
2585 : static void
2586 1106348 : match_clause_to_index(PlannerInfo *root,
2587 : RestrictInfo *rinfo,
2588 : IndexOptInfo *index,
2589 : IndexClauseSet *clauseset)
2590 : {
2591 : int indexcol;
2592 :
2593 : /*
2594 : * Never match pseudoconstants to indexes. (Normally a match could not
2595 : * happen anyway, since a pseudoconstant clause couldn't contain a Var,
2596 : * but what if someone builds an expression index on a constant? It's not
2597 : * totally unreasonable to do so with a partial index, either.)
2598 : */
2599 1106348 : if (rinfo->pseudoconstant)
2600 13164 : return;
2601 :
2602 : /*
2603 : * If clause can't be used as an indexqual because it must wait till after
2604 : * some lower-security-level restriction clause, reject it.
2605 : */
2606 1093184 : if (!restriction_is_securely_promotable(rinfo, index->rel))
2607 474 : return;
2608 :
2609 : /* OK, check each index key column for a match */
2610 2429836 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2611 : {
2612 : IndexClause *iclause;
2613 : ListCell *lc;
2614 :
2615 : /* Ignore duplicates */
2616 1813794 : foreach(lc, clauseset->indexclauses[indexcol])
2617 : {
2618 75352 : iclause = (IndexClause *) lfirst(lc);
2619 :
2620 75352 : if (iclause->rinfo == rinfo)
2621 0 : return;
2622 : }
2623 :
2624 : /* OK, try to match the clause to the index column */
2625 1738442 : iclause = match_clause_to_indexcol(root,
2626 : rinfo,
2627 : indexcol,
2628 : index);
2629 1738442 : if (iclause)
2630 : {
2631 : /* Success, so record it */
2632 401316 : clauseset->indexclauses[indexcol] =
2633 401316 : lappend(clauseset->indexclauses[indexcol], iclause);
2634 401316 : clauseset->nonempty = true;
2635 401316 : return;
2636 : }
2637 : }
2638 : }
2639 :
2640 : /*
2641 : * match_clause_to_indexcol()
2642 : * Determine whether a restriction clause matches a column of an index,
2643 : * and if so, build an IndexClause node describing the details.
2644 : *
2645 : * To match an index normally, an operator clause:
2646 : *
2647 : * (1) must be in the form (indexkey op const) or (const op indexkey);
2648 : * and
2649 : * (2) must contain an operator which is in the index's operator family
2650 : * for this column; and
2651 : * (3) must match the collation of the index, if collation is relevant.
2652 : *
2653 : * Our definition of "const" is exceedingly liberal: we allow anything that
2654 : * doesn't involve a volatile function or a Var of the index's relation.
2655 : * In particular, Vars belonging to other relations of the query are
2656 : * accepted here, since a clause of that form can be used in a
2657 : * parameterized indexscan. It's the responsibility of higher code levels
2658 : * to manage restriction and join clauses appropriately.
2659 : *
2660 : * Note: we do need to check for Vars of the index's relation on the
2661 : * "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
2662 : * are not processable by a parameterized indexscan on a.f1, whereas
2663 : * something like (a.f1 OP (b.f2 OP c.f3)) is.
2664 : *
2665 : * Presently, the executor can only deal with indexquals that have the
2666 : * indexkey on the left, so we can only use clauses that have the indexkey
2667 : * on the right if we can commute the clause to put the key on the left.
2668 : * We handle that by generating an IndexClause with the correctly-commuted
2669 : * opclause as a derived indexqual.
2670 : *
2671 : * If the index has a collation, the clause must have the same collation.
2672 : * For collation-less indexes, we assume it doesn't matter; this is
2673 : * necessary for cases like "hstore ? text", wherein hstore's operators
2674 : * don't care about collation but the clause will get marked with a
2675 : * collation anyway because of the text argument. (This logic is
2676 : * embodied in the macro IndexCollMatchesExprColl.)
2677 : *
2678 : * It is also possible to match RowCompareExpr clauses to indexes (but
2679 : * currently, only btree indexes handle this).
2680 : *
2681 : * It is also possible to match ScalarArrayOpExpr clauses to indexes, when
2682 : * the clause is of the form "indexkey op ANY (arrayconst)".
2683 : *
2684 : * It is also possible to match a list of OR clauses if it might be
2685 : * transformed into a single ScalarArrayOpExpr clause. On success,
2686 : * the returning index clause will contain a transformed clause.
2687 : *
2688 : * For boolean indexes, it is also possible to match the clause directly
2689 : * to the indexkey; or perhaps the clause is (NOT indexkey).
2690 : *
2691 : * And, last but not least, some operators and functions can be processed
2692 : * to derive (typically lossy) indexquals from a clause that isn't in
2693 : * itself indexable. If we see that any operand of an OpExpr or FuncExpr
2694 : * matches the index key, and the function has a planner support function
2695 : * attached to it, we'll invoke the support function to see if such an
2696 : * indexqual can be built.
2697 : *
2698 : * 'rinfo' is the clause to be tested (as a RestrictInfo node).
2699 : * 'indexcol' is a column number of 'index' (counting from 0).
2700 : * 'index' is the index of interest.
2701 : *
2702 : * Returns an IndexClause if the clause can be used with this index key,
2703 : * or NULL if not.
2704 : *
2705 : * NOTE: This routine always returns NULL if the clause is an AND clause.
2706 : * Higher-level routines deal with OR and AND clauses. OR clause can be
2707 : * matched as a whole by match_orclause_to_indexcol() though.
2708 : */
2709 : static IndexClause *
2710 1738442 : match_clause_to_indexcol(PlannerInfo *root,
2711 : RestrictInfo *rinfo,
2712 : int indexcol,
2713 : IndexOptInfo *index)
2714 : {
2715 : IndexClause *iclause;
2716 1738442 : Expr *clause = rinfo->clause;
2717 : Oid opfamily;
2718 :
2719 : Assert(indexcol < index->nkeycolumns);
2720 :
2721 : /*
2722 : * Historically this code has coped with NULL clauses. That's probably
2723 : * not possible anymore, but we might as well continue to cope.
2724 : */
2725 1738442 : if (clause == NULL)
2726 0 : return NULL;
2727 :
2728 : /* First check for boolean-index cases. */
2729 1738442 : opfamily = index->opfamily[indexcol];
2730 1738442 : if (IsBooleanOpfamily(opfamily))
2731 : {
2732 446 : iclause = match_boolean_index_clause(root, rinfo, indexcol, index);
2733 446 : if (iclause)
2734 294 : return iclause;
2735 : }
2736 :
2737 : /*
2738 : * Clause must be an opclause, funcclause, ScalarArrayOpExpr,
2739 : * RowCompareExpr, or OR-clause that could be converted to SAOP. Or, if
2740 : * the index supports it, we can handle IS NULL/NOT NULL clauses.
2741 : */
2742 1738148 : if (IsA(clause, OpExpr))
2743 : {
2744 1447086 : return match_opclause_to_indexcol(root, rinfo, indexcol, index);
2745 : }
2746 291062 : else if (IsA(clause, FuncExpr))
2747 : {
2748 31468 : return match_funcclause_to_indexcol(root, rinfo, indexcol, index);
2749 : }
2750 259594 : else if (IsA(clause, ScalarArrayOpExpr))
2751 : {
2752 82674 : return match_saopclause_to_indexcol(root, rinfo, indexcol, index);
2753 : }
2754 176920 : else if (IsA(clause, RowCompareExpr))
2755 : {
2756 432 : return match_rowcompare_to_indexcol(root, rinfo, indexcol, index);
2757 : }
2758 176488 : else if (restriction_is_or_clause(rinfo))
2759 : {
2760 49008 : return match_orclause_to_indexcol(root, rinfo, indexcol, index);
2761 : }
2762 127480 : else if (index->amsearchnulls && IsA(clause, NullTest))
2763 : {
2764 16324 : NullTest *nt = (NullTest *) clause;
2765 :
2766 32648 : if (!nt->argisrow &&
2767 16324 : match_index_to_operand((Node *) nt->arg, indexcol, index))
2768 : {
2769 1474 : iclause = makeNode(IndexClause);
2770 1474 : iclause->rinfo = rinfo;
2771 1474 : iclause->indexquals = list_make1(rinfo);
2772 1474 : iclause->lossy = false;
2773 1474 : iclause->indexcol = indexcol;
2774 1474 : iclause->indexcols = NIL;
2775 1474 : return iclause;
2776 : }
2777 : }
2778 :
2779 126006 : return NULL;
2780 : }
2781 :
2782 : /*
2783 : * IsBooleanOpfamily
2784 : * Detect whether an opfamily supports boolean equality as an operator.
2785 : *
2786 : * If the opfamily OID is in the range of built-in objects, we can rely
2787 : * on hard-wired knowledge of which built-in opfamilies support this.
2788 : * For extension opfamilies, there's no choice but to do a catcache lookup.
2789 : */
2790 : static bool
2791 2384726 : IsBooleanOpfamily(Oid opfamily)
2792 : {
2793 2384726 : if (opfamily < FirstNormalObjectId)
2794 2381510 : return IsBuiltinBooleanOpfamily(opfamily);
2795 : else
2796 3216 : return op_in_opfamily(BooleanEqualOperator, opfamily);
2797 : }
2798 :
2799 : /*
2800 : * match_boolean_index_clause
2801 : * Recognize restriction clauses that can be matched to a boolean index.
2802 : *
2803 : * The idea here is that, for an index on a boolean column that supports the
2804 : * BooleanEqualOperator, we can transform a plain reference to the indexkey
2805 : * into "indexkey = true", or "NOT indexkey" into "indexkey = false", etc,
2806 : * so as to make the expression indexable using the index's "=" operator.
2807 : * Since Postgres 8.1, we must do this because constant simplification does
2808 : * the reverse transformation; without this code there'd be no way to use
2809 : * such an index at all.
2810 : *
2811 : * This should be called only when IsBooleanOpfamily() recognizes the
2812 : * index's operator family. We check to see if the clause matches the
2813 : * index's key, and if so, build a suitable IndexClause.
2814 : */
2815 : static IndexClause *
2816 1706 : match_boolean_index_clause(PlannerInfo *root,
2817 : RestrictInfo *rinfo,
2818 : int indexcol,
2819 : IndexOptInfo *index)
2820 : {
2821 1706 : Node *clause = (Node *) rinfo->clause;
2822 1706 : Expr *op = NULL;
2823 :
2824 : /* Direct match? */
2825 1706 : if (match_index_to_operand(clause, indexcol, index))
2826 : {
2827 : /* convert to indexkey = TRUE */
2828 274 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2829 : (Expr *) clause,
2830 274 : (Expr *) makeBoolConst(true, false),
2831 : InvalidOid, InvalidOid);
2832 : }
2833 : /* NOT clause? */
2834 1432 : else if (is_notclause(clause))
2835 : {
2836 1208 : Node *arg = (Node *) get_notclausearg((Expr *) clause);
2837 :
2838 1208 : if (match_index_to_operand(arg, indexcol, index))
2839 : {
2840 : /* convert to indexkey = FALSE */
2841 1208 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2842 : (Expr *) arg,
2843 1208 : (Expr *) makeBoolConst(false, false),
2844 : InvalidOid, InvalidOid);
2845 : }
2846 : }
2847 :
2848 : /*
2849 : * Since we only consider clauses at top level of WHERE, we can convert
2850 : * indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
2851 : * different meaning for NULL isn't important.
2852 : */
2853 224 : else if (clause && IsA(clause, BooleanTest))
2854 : {
2855 36 : BooleanTest *btest = (BooleanTest *) clause;
2856 36 : Node *arg = (Node *) btest->arg;
2857 :
2858 54 : if (btest->booltesttype == IS_TRUE &&
2859 18 : match_index_to_operand(arg, indexcol, index))
2860 : {
2861 : /* convert to indexkey = TRUE */
2862 18 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2863 : (Expr *) arg,
2864 18 : (Expr *) makeBoolConst(true, false),
2865 : InvalidOid, InvalidOid);
2866 : }
2867 36 : else if (btest->booltesttype == IS_FALSE &&
2868 18 : match_index_to_operand(arg, indexcol, index))
2869 : {
2870 : /* convert to indexkey = FALSE */
2871 18 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2872 : (Expr *) arg,
2873 18 : (Expr *) makeBoolConst(false, false),
2874 : InvalidOid, InvalidOid);
2875 : }
2876 : }
2877 :
2878 : /*
2879 : * If we successfully made an operator clause from the given qual, we must
2880 : * wrap it in an IndexClause. It's not lossy.
2881 : */
2882 1706 : if (op)
2883 : {
2884 1518 : IndexClause *iclause = makeNode(IndexClause);
2885 :
2886 1518 : iclause->rinfo = rinfo;
2887 1518 : iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
2888 1518 : iclause->lossy = false;
2889 1518 : iclause->indexcol = indexcol;
2890 1518 : iclause->indexcols = NIL;
2891 1518 : return iclause;
2892 : }
2893 :
2894 188 : return NULL;
2895 : }
2896 :
2897 : /*
2898 : * match_opclause_to_indexcol()
2899 : * Handles the OpExpr case for match_clause_to_indexcol(),
2900 : * which see for comments.
2901 : */
2902 : static IndexClause *
2903 1447086 : match_opclause_to_indexcol(PlannerInfo *root,
2904 : RestrictInfo *rinfo,
2905 : int indexcol,
2906 : IndexOptInfo *index)
2907 : {
2908 : IndexClause *iclause;
2909 1447086 : OpExpr *clause = (OpExpr *) rinfo->clause;
2910 : Node *leftop,
2911 : *rightop;
2912 : Oid expr_op;
2913 : Oid expr_coll;
2914 : Index index_relid;
2915 : Oid opfamily;
2916 : Oid idxcollation;
2917 :
2918 : /*
2919 : * Only binary operators need apply. (In theory, a planner support
2920 : * function could do something with a unary operator, but it seems
2921 : * unlikely to be worth the cycles to check.)
2922 : */
2923 1447086 : if (list_length(clause->args) != 2)
2924 0 : return NULL;
2925 :
2926 1447086 : leftop = (Node *) linitial(clause->args);
2927 1447086 : rightop = (Node *) lsecond(clause->args);
2928 1447086 : expr_op = clause->opno;
2929 1447086 : expr_coll = clause->inputcollid;
2930 :
2931 1447086 : index_relid = index->rel->relid;
2932 1447086 : opfamily = index->opfamily[indexcol];
2933 1447086 : idxcollation = index->indexcollations[indexcol];
2934 :
2935 : /*
2936 : * Check for clauses of the form: (indexkey operator constant) or
2937 : * (constant operator indexkey). See match_clause_to_indexcol's notes
2938 : * about const-ness.
2939 : *
2940 : * Note that we don't ask the support function about clauses that don't
2941 : * have one of these forms. Again, in principle it might be possible to
2942 : * do something, but it seems unlikely to be worth the cycles to check.
2943 : */
2944 1447086 : if (match_index_to_operand(leftop, indexcol, index) &&
2945 342010 : !bms_is_member(index_relid, rinfo->right_relids) &&
2946 341836 : !contain_volatile_functions(rightop))
2947 : {
2948 677082 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
2949 335246 : op_in_opfamily(expr_op, opfamily))
2950 : {
2951 327686 : iclause = makeNode(IndexClause);
2952 327686 : iclause->rinfo = rinfo;
2953 327686 : iclause->indexquals = list_make1(rinfo);
2954 327686 : iclause->lossy = false;
2955 327686 : iclause->indexcol = indexcol;
2956 327686 : iclause->indexcols = NIL;
2957 327686 : return iclause;
2958 : }
2959 :
2960 : /*
2961 : * If we didn't find a member of the index's opfamily, try the support
2962 : * function for the operator's underlying function.
2963 : */
2964 14150 : set_opfuncid(clause); /* make sure we have opfuncid */
2965 14150 : return get_index_clause_from_support(root,
2966 : rinfo,
2967 : clause->opfuncid,
2968 : 0, /* indexarg on left */
2969 : indexcol,
2970 : index);
2971 : }
2972 :
2973 1105250 : if (match_index_to_operand(rightop, indexcol, index) &&
2974 62978 : !bms_is_member(index_relid, rinfo->left_relids) &&
2975 62852 : !contain_volatile_functions(leftop))
2976 : {
2977 62852 : if (IndexCollMatchesExprColl(idxcollation, expr_coll))
2978 : {
2979 62840 : Oid comm_op = get_commutator(expr_op);
2980 :
2981 125680 : if (OidIsValid(comm_op) &&
2982 62840 : op_in_opfamily(comm_op, opfamily))
2983 : {
2984 : RestrictInfo *commrinfo;
2985 :
2986 : /* Build a commuted OpExpr and RestrictInfo */
2987 62260 : commrinfo = commute_restrictinfo(rinfo, comm_op);
2988 :
2989 : /* Make an IndexClause showing that as a derived qual */
2990 62260 : iclause = makeNode(IndexClause);
2991 62260 : iclause->rinfo = rinfo;
2992 62260 : iclause->indexquals = list_make1(commrinfo);
2993 62260 : iclause->lossy = false;
2994 62260 : iclause->indexcol = indexcol;
2995 62260 : iclause->indexcols = NIL;
2996 62260 : return iclause;
2997 : }
2998 : }
2999 :
3000 : /*
3001 : * If we didn't find a member of the index's opfamily, try the support
3002 : * function for the operator's underlying function.
3003 : */
3004 592 : set_opfuncid(clause); /* make sure we have opfuncid */
3005 592 : return get_index_clause_from_support(root,
3006 : rinfo,
3007 : clause->opfuncid,
3008 : 1, /* indexarg on right */
3009 : indexcol,
3010 : index);
3011 : }
3012 :
3013 1042398 : return NULL;
3014 : }
3015 :
3016 : /*
3017 : * match_funcclause_to_indexcol()
3018 : * Handles the FuncExpr case for match_clause_to_indexcol(),
3019 : * which see for comments.
3020 : */
3021 : static IndexClause *
3022 31468 : match_funcclause_to_indexcol(PlannerInfo *root,
3023 : RestrictInfo *rinfo,
3024 : int indexcol,
3025 : IndexOptInfo *index)
3026 : {
3027 31468 : FuncExpr *clause = (FuncExpr *) rinfo->clause;
3028 : int indexarg;
3029 : ListCell *lc;
3030 :
3031 : /*
3032 : * We have no built-in intelligence about function clauses, but if there's
3033 : * a planner support function, it might be able to do something. But, to
3034 : * cut down on wasted planning cycles, only call the support function if
3035 : * at least one argument matches the target index column.
3036 : *
3037 : * Note that we don't insist on the other arguments being pseudoconstants;
3038 : * the support function has to check that. This is to allow cases where
3039 : * only some of the other arguments need to be included in the indexqual.
3040 : */
3041 31468 : indexarg = 0;
3042 70668 : foreach(lc, clause->args)
3043 : {
3044 45402 : Node *op = (Node *) lfirst(lc);
3045 :
3046 45402 : if (match_index_to_operand(op, indexcol, index))
3047 : {
3048 6202 : return get_index_clause_from_support(root,
3049 : rinfo,
3050 : clause->funcid,
3051 : indexarg,
3052 : indexcol,
3053 : index);
3054 : }
3055 :
3056 39200 : indexarg++;
3057 : }
3058 :
3059 25266 : return NULL;
3060 : }
3061 :
3062 : /*
3063 : * get_index_clause_from_support()
3064 : * If the function has a planner support function, try to construct
3065 : * an IndexClause using indexquals created by the support function.
3066 : */
3067 : static IndexClause *
3068 20944 : get_index_clause_from_support(PlannerInfo *root,
3069 : RestrictInfo *rinfo,
3070 : Oid funcid,
3071 : int indexarg,
3072 : int indexcol,
3073 : IndexOptInfo *index)
3074 : {
3075 20944 : Oid prosupport = get_func_support(funcid);
3076 : SupportRequestIndexCondition req;
3077 : List *sresult;
3078 :
3079 20944 : if (!OidIsValid(prosupport))
3080 12878 : return NULL;
3081 :
3082 8066 : req.type = T_SupportRequestIndexCondition;
3083 8066 : req.root = root;
3084 8066 : req.funcid = funcid;
3085 8066 : req.node = (Node *) rinfo->clause;
3086 8066 : req.indexarg = indexarg;
3087 8066 : req.index = index;
3088 8066 : req.indexcol = indexcol;
3089 8066 : req.opfamily = index->opfamily[indexcol];
3090 8066 : req.indexcollation = index->indexcollations[indexcol];
3091 :
3092 8066 : req.lossy = true; /* default assumption */
3093 :
3094 : sresult = (List *)
3095 8066 : DatumGetPointer(OidFunctionCall1(prosupport,
3096 : PointerGetDatum(&req)));
3097 :
3098 8066 : if (sresult != NIL)
3099 : {
3100 1404 : IndexClause *iclause = makeNode(IndexClause);
3101 1404 : List *indexquals = NIL;
3102 : ListCell *lc;
3103 :
3104 : /*
3105 : * The support function API says it should just give back bare
3106 : * clauses, so here we must wrap each one in a RestrictInfo.
3107 : */
3108 4134 : foreach(lc, sresult)
3109 : {
3110 2730 : Expr *clause = (Expr *) lfirst(lc);
3111 :
3112 2730 : indexquals = lappend(indexquals,
3113 2730 : make_simple_restrictinfo(root, clause));
3114 : }
3115 :
3116 1404 : iclause->rinfo = rinfo;
3117 1404 : iclause->indexquals = indexquals;
3118 1404 : iclause->lossy = req.lossy;
3119 1404 : iclause->indexcol = indexcol;
3120 1404 : iclause->indexcols = NIL;
3121 :
3122 1404 : return iclause;
3123 : }
3124 :
3125 6662 : return NULL;
3126 : }
3127 :
3128 : /*
3129 : * match_saopclause_to_indexcol()
3130 : * Handles the ScalarArrayOpExpr case for match_clause_to_indexcol(),
3131 : * which see for comments.
3132 : */
3133 : static IndexClause *
3134 82674 : match_saopclause_to_indexcol(PlannerInfo *root,
3135 : RestrictInfo *rinfo,
3136 : int indexcol,
3137 : IndexOptInfo *index)
3138 : {
3139 82674 : ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
3140 : Node *leftop,
3141 : *rightop;
3142 : Relids right_relids;
3143 : Oid expr_op;
3144 : Oid expr_coll;
3145 : Index index_relid;
3146 : Oid opfamily;
3147 : Oid idxcollation;
3148 :
3149 : /* We only accept ANY clauses, not ALL */
3150 82674 : if (!saop->useOr)
3151 15200 : return NULL;
3152 67474 : leftop = (Node *) linitial(saop->args);
3153 67474 : rightop = (Node *) lsecond(saop->args);
3154 67474 : right_relids = pull_varnos(root, rightop);
3155 67474 : expr_op = saop->opno;
3156 67474 : expr_coll = saop->inputcollid;
3157 :
3158 67474 : index_relid = index->rel->relid;
3159 67474 : opfamily = index->opfamily[indexcol];
3160 67474 : idxcollation = index->indexcollations[indexcol];
3161 :
3162 : /*
3163 : * We must have indexkey on the left and a pseudo-constant array argument.
3164 : */
3165 67474 : if (match_index_to_operand(leftop, indexcol, index) &&
3166 7016 : !bms_is_member(index_relid, right_relids) &&
3167 7016 : !contain_volatile_functions(rightop))
3168 : {
3169 14026 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
3170 7010 : op_in_opfamily(expr_op, opfamily))
3171 : {
3172 6998 : IndexClause *iclause = makeNode(IndexClause);
3173 :
3174 6998 : iclause->rinfo = rinfo;
3175 6998 : iclause->indexquals = list_make1(rinfo);
3176 6998 : iclause->lossy = false;
3177 6998 : iclause->indexcol = indexcol;
3178 6998 : iclause->indexcols = NIL;
3179 6998 : return iclause;
3180 : }
3181 :
3182 : /*
3183 : * We do not currently ask support functions about ScalarArrayOpExprs,
3184 : * though in principle we could.
3185 : */
3186 : }
3187 :
3188 60476 : return NULL;
3189 : }
3190 :
3191 : /*
3192 : * match_rowcompare_to_indexcol()
3193 : * Handles the RowCompareExpr case for match_clause_to_indexcol(),
3194 : * which see for comments.
3195 : *
3196 : * In this routine we check whether the first column of the row comparison
3197 : * matches the target index column. This is sufficient to guarantee that some
3198 : * index condition can be constructed from the RowCompareExpr --- the rest
3199 : * is handled by expand_indexqual_rowcompare().
3200 : */
3201 : static IndexClause *
3202 432 : match_rowcompare_to_indexcol(PlannerInfo *root,
3203 : RestrictInfo *rinfo,
3204 : int indexcol,
3205 : IndexOptInfo *index)
3206 : {
3207 432 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3208 : Index index_relid;
3209 : Oid opfamily;
3210 : Oid idxcollation;
3211 : Node *leftop,
3212 : *rightop;
3213 : bool var_on_left;
3214 : Oid expr_op;
3215 : Oid expr_coll;
3216 :
3217 : /* Forget it if we're not dealing with a btree index */
3218 432 : if (index->relam != BTREE_AM_OID)
3219 0 : return NULL;
3220 :
3221 432 : index_relid = index->rel->relid;
3222 432 : opfamily = index->opfamily[indexcol];
3223 432 : idxcollation = index->indexcollations[indexcol];
3224 :
3225 : /*
3226 : * We could do the matching on the basis of insisting that the opfamily
3227 : * shown in the RowCompareExpr be the same as the index column's opfamily,
3228 : * but that could fail in the presence of reverse-sort opfamilies: it'd be
3229 : * a matter of chance whether RowCompareExpr had picked the forward or
3230 : * reverse-sort family. So look only at the operator, and match if it is
3231 : * a member of the index's opfamily (after commutation, if the indexkey is
3232 : * on the right). We'll worry later about whether any additional
3233 : * operators are matchable to the index.
3234 : */
3235 432 : leftop = (Node *) linitial(clause->largs);
3236 432 : rightop = (Node *) linitial(clause->rargs);
3237 432 : expr_op = linitial_oid(clause->opnos);
3238 432 : expr_coll = linitial_oid(clause->inputcollids);
3239 :
3240 : /* Collations must match, if relevant */
3241 432 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3242 0 : return NULL;
3243 :
3244 : /*
3245 : * These syntactic tests are the same as in match_opclause_to_indexcol()
3246 : */
3247 432 : if (match_index_to_operand(leftop, indexcol, index) &&
3248 126 : !bms_is_member(index_relid, pull_varnos(root, rightop)) &&
3249 126 : !contain_volatile_functions(rightop))
3250 : {
3251 : /* OK, indexkey is on left */
3252 126 : var_on_left = true;
3253 : }
3254 306 : else if (match_index_to_operand(rightop, indexcol, index) &&
3255 24 : !bms_is_member(index_relid, pull_varnos(root, leftop)) &&
3256 24 : !contain_volatile_functions(leftop))
3257 : {
3258 : /* indexkey is on right, so commute the operator */
3259 24 : expr_op = get_commutator(expr_op);
3260 24 : if (expr_op == InvalidOid)
3261 0 : return NULL;
3262 24 : var_on_left = false;
3263 : }
3264 : else
3265 282 : return NULL;
3266 :
3267 : /* We're good if the operator is the right type of opfamily member */
3268 150 : switch (get_op_opfamily_strategy(expr_op, opfamily))
3269 : {
3270 150 : case BTLessStrategyNumber:
3271 : case BTLessEqualStrategyNumber:
3272 : case BTGreaterEqualStrategyNumber:
3273 : case BTGreaterStrategyNumber:
3274 150 : return expand_indexqual_rowcompare(root,
3275 : rinfo,
3276 : indexcol,
3277 : index,
3278 : expr_op,
3279 : var_on_left);
3280 : }
3281 :
3282 0 : return NULL;
3283 : }
3284 :
3285 : /*
3286 : * match_orclause_to_indexcol()
3287 : * Handles the OR-expr case for match_clause_to_indexcol() in the case
3288 : * when it could be transformed to ScalarArrayOpExpr.
3289 : *
3290 : * In this routine, we attempt to transform a list of OR-clause args into a
3291 : * single SAOP expression matching the target index column. On success,
3292 : * return an IndexClause, containing the transformed expression or NULL,
3293 : * if failed.
3294 : */
3295 : static IndexClause *
3296 49008 : match_orclause_to_indexcol(PlannerInfo *root,
3297 : RestrictInfo *rinfo,
3298 : int indexcol,
3299 : IndexOptInfo *index)
3300 : {
3301 : ListCell *lc;
3302 49008 : BoolExpr *orclause = (BoolExpr *) rinfo->orclause;
3303 49008 : Node *indexExpr = NULL;
3304 49008 : List *consts = NIL;
3305 49008 : ScalarArrayOpExpr *saopexpr = NULL;
3306 49008 : Oid matchOpno = InvalidOid;
3307 : IndexClause *iclause;
3308 49008 : Oid consttype = InvalidOid;
3309 49008 : Oid arraytype = InvalidOid;
3310 49008 : Oid inputcollid = InvalidOid;
3311 49008 : bool firstTime = true;
3312 49008 : bool haveNonConst = false;
3313 49008 : Index indexRelid = index->rel->relid;
3314 :
3315 : Assert(IsA(orclause, BoolExpr));
3316 : Assert(orclause->boolop == OR_EXPR);
3317 :
3318 : /* Ignore index if it doesn't support SAOP clauses */
3319 49008 : if (!index->amsearcharray)
3320 106 : return NULL;
3321 :
3322 : /*
3323 : * Try to convert a list of OR-clauses to a single SAOP expression. Each
3324 : * OR entry must be in the form: (indexkey operator constant) or (constant
3325 : * operator indexkey). Operators of all the entries must match. To be
3326 : * effective, give up on the first non-matching entry. Exit is
3327 : * implemented as a break from the loop, which is catched afterwards.
3328 : */
3329 53290 : foreach(lc, orclause->args)
3330 : {
3331 : RestrictInfo *subRinfo;
3332 : OpExpr *subClause;
3333 : Oid opno;
3334 : Node *leftop,
3335 : *rightop;
3336 : Node *constExpr;
3337 :
3338 52240 : if (!IsA(lfirst(lc), RestrictInfo))
3339 5198 : break;
3340 :
3341 47042 : subRinfo = (RestrictInfo *) lfirst(lc);
3342 :
3343 : /* Only operator clauses can match */
3344 47042 : if (!IsA(subRinfo->clause, OpExpr))
3345 14622 : break;
3346 :
3347 32420 : subClause = (OpExpr *) subRinfo->clause;
3348 32420 : opno = subClause->opno;
3349 :
3350 : /* Only binary operators can match */
3351 32420 : if (list_length(subClause->args) != 2)
3352 0 : break;
3353 :
3354 : /*
3355 : * The parameters below must match between sub-rinfo and its parent as
3356 : * make_restrictinfo() fills them with the same values, and further
3357 : * modifications are also the same for the whole subtree. However,
3358 : * still make a sanity check.
3359 : */
3360 : Assert(subRinfo->is_pushed_down == rinfo->is_pushed_down);
3361 : Assert(subRinfo->is_clone == rinfo->is_clone);
3362 : Assert(subRinfo->security_level == rinfo->security_level);
3363 : Assert(bms_equal(subRinfo->incompatible_relids, rinfo->incompatible_relids));
3364 : Assert(bms_equal(subRinfo->outer_relids, rinfo->outer_relids));
3365 :
3366 : /*
3367 : * Also, check that required_relids in sub-rinfo is subset of parent's
3368 : * required_relids.
3369 : */
3370 : Assert(bms_is_subset(subRinfo->required_relids, rinfo->required_relids));
3371 :
3372 : /* Only the operator returning a boolean suit the transformation. */
3373 32420 : if (get_op_rettype(opno) != BOOLOID)
3374 0 : break;
3375 :
3376 : /*
3377 : * Check for clauses of the form: (indexkey operator constant) or
3378 : * (constant operator indexkey). See match_clause_to_indexcol's notes
3379 : * about const-ness.
3380 : */
3381 32420 : leftop = (Node *) linitial(subClause->args);
3382 32420 : rightop = (Node *) lsecond(subClause->args);
3383 32420 : if (match_index_to_operand(leftop, indexcol, index) &&
3384 6604 : !bms_is_member(indexRelid, subRinfo->right_relids) &&
3385 6574 : !contain_volatile_functions(rightop))
3386 : {
3387 6574 : indexExpr = leftop;
3388 6574 : constExpr = rightop;
3389 : }
3390 25846 : else if (match_index_to_operand(rightop, indexcol, index) &&
3391 170 : !bms_is_member(indexRelid, subRinfo->left_relids) &&
3392 164 : !contain_volatile_functions(leftop))
3393 : {
3394 164 : opno = get_commutator(opno);
3395 164 : if (!OidIsValid(opno))
3396 : {
3397 : /* commutator doesn't exist, we can't reverse the order */
3398 0 : break;
3399 : }
3400 164 : indexExpr = rightop;
3401 164 : constExpr = leftop;
3402 : }
3403 : else
3404 : {
3405 : break;
3406 : }
3407 :
3408 : /*
3409 : * Ignore any RelabelType node above the operands. This is needed to
3410 : * be able to apply indexscanning in binary-compatible-operator cases.
3411 : * Note: we can assume there is at most one RelabelType node;
3412 : * eval_const_expressions() will have simplified if more than one.
3413 : */
3414 6738 : if (IsA(constExpr, RelabelType))
3415 0 : constExpr = (Node *) ((RelabelType *) constExpr)->arg;
3416 6738 : if (IsA(indexExpr, RelabelType))
3417 12 : indexExpr = (Node *) ((RelabelType *) indexExpr)->arg;
3418 :
3419 : /* Forbid transformation for composite types, records. */
3420 13476 : if (type_is_rowtype(exprType(constExpr)) ||
3421 6738 : type_is_rowtype(exprType(indexExpr)))
3422 : break;
3423 :
3424 : /*
3425 : * Save information about the operator, type, and collation for the
3426 : * first matching qual. Then, check that subsequent quals match the
3427 : * first.
3428 : */
3429 6738 : if (firstTime)
3430 : {
3431 4998 : matchOpno = opno;
3432 4998 : consttype = exprType(constExpr);
3433 4998 : arraytype = get_array_type(consttype);
3434 4998 : inputcollid = subClause->inputcollid;
3435 :
3436 : /*
3437 : * Check that the operator is presented in the opfamily and that
3438 : * the expression collation matches the index collation. Also,
3439 : * there must be an array type to construct an array later.
3440 : */
3441 4998 : if (!IndexCollMatchesExprColl(index->indexcollations[indexcol], inputcollid) ||
3442 4872 : !op_in_opfamily(matchOpno, index->opfamily[indexcol]) ||
3443 : !OidIsValid(arraytype))
3444 : break;
3445 2774 : firstTime = false;
3446 : }
3447 : else
3448 : {
3449 1740 : if (opno != matchOpno ||
3450 3228 : inputcollid != subClause->inputcollid ||
3451 1614 : consttype != exprType(constExpr))
3452 : break;
3453 : }
3454 :
3455 : /*
3456 : * Check if our list of constants in match_clause_to_indexcol's
3457 : * understanding of const-ness have something other than Const.
3458 : */
3459 4388 : if (!IsA(constExpr, Const))
3460 344 : haveNonConst = true;
3461 4388 : consts = lappend(consts, constExpr);
3462 : }
3463 :
3464 : /*
3465 : * Catch the break from the loop above. Normally, a foreach() loop ends
3466 : * up with a NULL list cell. A non-NULL list cell indicates a break from
3467 : * the foreach() loop. Free the consts list and return NULL then.
3468 : */
3469 48902 : if (lc != NULL)
3470 : {
3471 47852 : list_free(consts);
3472 47852 : return NULL;
3473 : }
3474 :
3475 1050 : saopexpr = make_SAOP_expr(matchOpno, indexExpr, consttype, inputcollid,
3476 : inputcollid, consts, haveNonConst);
3477 :
3478 : /*
3479 : * Finally, build an IndexClause based on the SAOP node. Use
3480 : * make_simple_restrictinfo() to get RestrictInfo with clean selectivity
3481 : * estimations, because they may differ from the estimation made for an OR
3482 : * clause. Although it is not a lossy expression, keep the original rinfo
3483 : * in iclause->rinfo as prescribed.
3484 : */
3485 1050 : iclause = makeNode(IndexClause);
3486 1050 : iclause->rinfo = rinfo;
3487 1050 : iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3488 : &saopexpr->xpr));
3489 1050 : iclause->lossy = false;
3490 1050 : iclause->indexcol = indexcol;
3491 1050 : iclause->indexcols = NIL;
3492 1050 : return iclause;
3493 : }
3494 :
3495 : /*
3496 : * expand_indexqual_rowcompare --- expand a single indexqual condition
3497 : * that is a RowCompareExpr
3498 : *
3499 : * It's already known that the first column of the row comparison matches
3500 : * the specified column of the index. We can use additional columns of the
3501 : * row comparison as index qualifications, so long as they match the index
3502 : * in the "same direction", ie, the indexkeys are all on the same side of the
3503 : * clause and the operators are all the same-type members of the opfamilies.
3504 : *
3505 : * If all the columns of the RowCompareExpr match in this way, we just use it
3506 : * as-is, except for possibly commuting it to put the indexkeys on the left.
3507 : *
3508 : * Otherwise, we build a shortened RowCompareExpr (if more than one
3509 : * column matches) or a simple OpExpr (if the first-column match is all
3510 : * there is). In these cases the modified clause is always "<=" or ">="
3511 : * even when the original was "<" or ">" --- this is necessary to match all
3512 : * the rows that could match the original. (We are building a lossy version
3513 : * of the row comparison when we do this, so we set lossy = true.)
3514 : *
3515 : * Note: this is really just the last half of match_rowcompare_to_indexcol,
3516 : * but we split it out for comprehensibility.
3517 : */
3518 : static IndexClause *
3519 150 : expand_indexqual_rowcompare(PlannerInfo *root,
3520 : RestrictInfo *rinfo,
3521 : int indexcol,
3522 : IndexOptInfo *index,
3523 : Oid expr_op,
3524 : bool var_on_left)
3525 : {
3526 150 : IndexClause *iclause = makeNode(IndexClause);
3527 150 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3528 : int op_strategy;
3529 : Oid op_lefttype;
3530 : Oid op_righttype;
3531 : int matching_cols;
3532 : List *expr_ops;
3533 : List *opfamilies;
3534 : List *lefttypes;
3535 : List *righttypes;
3536 : List *new_ops;
3537 : List *var_args;
3538 : List *non_var_args;
3539 :
3540 150 : iclause->rinfo = rinfo;
3541 150 : iclause->indexcol = indexcol;
3542 :
3543 150 : if (var_on_left)
3544 : {
3545 126 : var_args = clause->largs;
3546 126 : non_var_args = clause->rargs;
3547 : }
3548 : else
3549 : {
3550 24 : var_args = clause->rargs;
3551 24 : non_var_args = clause->largs;
3552 : }
3553 :
3554 150 : get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
3555 : &op_strategy,
3556 : &op_lefttype,
3557 : &op_righttype);
3558 :
3559 : /* Initialize returned list of which index columns are used */
3560 150 : iclause->indexcols = list_make1_int(indexcol);
3561 :
3562 : /* Build lists of ops, opfamilies and operator datatypes in case needed */
3563 150 : expr_ops = list_make1_oid(expr_op);
3564 150 : opfamilies = list_make1_oid(index->opfamily[indexcol]);
3565 150 : lefttypes = list_make1_oid(op_lefttype);
3566 150 : righttypes = list_make1_oid(op_righttype);
3567 :
3568 : /*
3569 : * See how many of the remaining columns match some index column in the
3570 : * same way. As in match_clause_to_indexcol(), the "other" side of any
3571 : * potential index condition is OK as long as it doesn't use Vars from the
3572 : * indexed relation.
3573 : */
3574 150 : matching_cols = 1;
3575 :
3576 282 : while (matching_cols < list_length(var_args))
3577 : {
3578 186 : Node *varop = (Node *) list_nth(var_args, matching_cols);
3579 186 : Node *constop = (Node *) list_nth(non_var_args, matching_cols);
3580 : int i;
3581 :
3582 186 : expr_op = list_nth_oid(clause->opnos, matching_cols);
3583 186 : if (!var_on_left)
3584 : {
3585 : /* indexkey is on right, so commute the operator */
3586 24 : expr_op = get_commutator(expr_op);
3587 24 : if (expr_op == InvalidOid)
3588 0 : break; /* operator is not usable */
3589 : }
3590 186 : if (bms_is_member(index->rel->relid, pull_varnos(root, constop)))
3591 0 : break; /* no good, Var on wrong side */
3592 186 : if (contain_volatile_functions(constop))
3593 0 : break; /* no good, volatile comparison value */
3594 :
3595 : /*
3596 : * The Var side can match any key column of the index.
3597 : */
3598 444 : for (i = 0; i < index->nkeycolumns; i++)
3599 : {
3600 390 : if (match_index_to_operand(varop, i, index) &&
3601 132 : get_op_opfamily_strategy(expr_op,
3602 132 : index->opfamily[i]) == op_strategy &&
3603 132 : IndexCollMatchesExprColl(index->indexcollations[i],
3604 : list_nth_oid(clause->inputcollids,
3605 : matching_cols)))
3606 : break;
3607 : }
3608 186 : if (i >= index->nkeycolumns)
3609 54 : break; /* no match found */
3610 :
3611 : /* Add column number to returned list */
3612 132 : iclause->indexcols = lappend_int(iclause->indexcols, i);
3613 :
3614 : /* Add operator info to lists */
3615 132 : get_op_opfamily_properties(expr_op, index->opfamily[i], false,
3616 : &op_strategy,
3617 : &op_lefttype,
3618 : &op_righttype);
3619 132 : expr_ops = lappend_oid(expr_ops, expr_op);
3620 132 : opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
3621 132 : lefttypes = lappend_oid(lefttypes, op_lefttype);
3622 132 : righttypes = lappend_oid(righttypes, op_righttype);
3623 :
3624 : /* This column matches, keep scanning */
3625 132 : matching_cols++;
3626 : }
3627 :
3628 : /* Result is non-lossy if all columns are usable as index quals */
3629 150 : iclause->lossy = (matching_cols != list_length(clause->opnos));
3630 :
3631 : /*
3632 : * We can use rinfo->clause as-is if we have var on left and it's all
3633 : * usable as index quals.
3634 : */
3635 150 : if (var_on_left && !iclause->lossy)
3636 84 : iclause->indexquals = list_make1(rinfo);
3637 : else
3638 : {
3639 : /*
3640 : * We have to generate a modified rowcompare (possibly just one
3641 : * OpExpr). The painful part of this is changing < to <= or > to >=,
3642 : * so deal with that first.
3643 : */
3644 66 : if (!iclause->lossy)
3645 : {
3646 : /* very easy, just use the commuted operators */
3647 12 : new_ops = expr_ops;
3648 : }
3649 54 : else if (op_strategy == BTLessEqualStrategyNumber ||
3650 54 : op_strategy == BTGreaterEqualStrategyNumber)
3651 : {
3652 : /* easy, just use the same (possibly commuted) operators */
3653 0 : new_ops = list_truncate(expr_ops, matching_cols);
3654 : }
3655 : else
3656 : {
3657 : ListCell *opfamilies_cell;
3658 : ListCell *lefttypes_cell;
3659 : ListCell *righttypes_cell;
3660 :
3661 54 : if (op_strategy == BTLessStrategyNumber)
3662 30 : op_strategy = BTLessEqualStrategyNumber;
3663 24 : else if (op_strategy == BTGreaterStrategyNumber)
3664 24 : op_strategy = BTGreaterEqualStrategyNumber;
3665 : else
3666 0 : elog(ERROR, "unexpected strategy number %d", op_strategy);
3667 54 : new_ops = NIL;
3668 144 : forthree(opfamilies_cell, opfamilies,
3669 : lefttypes_cell, lefttypes,
3670 : righttypes_cell, righttypes)
3671 : {
3672 90 : Oid opfam = lfirst_oid(opfamilies_cell);
3673 90 : Oid lefttype = lfirst_oid(lefttypes_cell);
3674 90 : Oid righttype = lfirst_oid(righttypes_cell);
3675 :
3676 90 : expr_op = get_opfamily_member(opfam, lefttype, righttype,
3677 : op_strategy);
3678 90 : if (!OidIsValid(expr_op)) /* should not happen */
3679 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3680 : op_strategy, lefttype, righttype, opfam);
3681 90 : new_ops = lappend_oid(new_ops, expr_op);
3682 : }
3683 : }
3684 :
3685 : /* If we have more than one matching col, create a subset rowcompare */
3686 66 : if (matching_cols > 1)
3687 : {
3688 48 : RowCompareExpr *rc = makeNode(RowCompareExpr);
3689 :
3690 48 : rc->cmptype = (CompareType) op_strategy;
3691 48 : rc->opnos = new_ops;
3692 48 : rc->opfamilies = list_copy_head(clause->opfamilies,
3693 : matching_cols);
3694 48 : rc->inputcollids = list_copy_head(clause->inputcollids,
3695 : matching_cols);
3696 48 : rc->largs = list_copy_head(var_args, matching_cols);
3697 48 : rc->rargs = list_copy_head(non_var_args, matching_cols);
3698 48 : iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3699 : (Expr *) rc));
3700 : }
3701 : else
3702 : {
3703 : Expr *op;
3704 :
3705 : /* We don't report an index column list in this case */
3706 18 : iclause->indexcols = NIL;
3707 :
3708 18 : op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
3709 18 : copyObject(linitial(var_args)),
3710 18 : copyObject(linitial(non_var_args)),
3711 : InvalidOid,
3712 18 : linitial_oid(clause->inputcollids));
3713 18 : iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
3714 : }
3715 : }
3716 :
3717 150 : return iclause;
3718 : }
3719 :
3720 :
3721 : /****************************************************************************
3722 : * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3723 : ****************************************************************************/
3724 :
3725 : /*
3726 : * match_pathkeys_to_index
3727 : * For the given 'index' and 'pathkeys', output a list of suitable ORDER
3728 : * BY expressions, each of the form "indexedcol operator pseudoconstant",
3729 : * along with an integer list of the index column numbers (zero based)
3730 : * that each clause would be used with.
3731 : *
3732 : * This attempts to find an ORDER BY and index column number for all items in
3733 : * the pathkey list, however, if we're unable to match any given pathkey to an
3734 : * index column, we return just the ones matched by the function so far. This
3735 : * allows callers who are interested in partial matches to get them. Callers
3736 : * can determine a partial match vs a full match by checking the outputted
3737 : * list lengths. A full match will have one item in the output lists for each
3738 : * item in the given 'pathkeys' list.
3739 : */
3740 : static void
3741 1074 : match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3742 : List **orderby_clauses_p,
3743 : List **clause_columns_p)
3744 : {
3745 : ListCell *lc1;
3746 :
3747 1074 : *orderby_clauses_p = NIL; /* set default results */
3748 1074 : *clause_columns_p = NIL;
3749 :
3750 : /* Only indexes with the amcanorderbyop property are interesting here */
3751 1074 : if (!index->amcanorderbyop)
3752 0 : return;
3753 :
3754 1548 : foreach(lc1, pathkeys)
3755 : {
3756 1080 : PathKey *pathkey = (PathKey *) lfirst(lc1);
3757 1080 : bool found = false;
3758 : EquivalenceMemberIterator it;
3759 : EquivalenceMember *member;
3760 :
3761 :
3762 : /* Pathkey must request default sort order for the target opfamily */
3763 1080 : if (pathkey->pk_cmptype != COMPARE_LT || pathkey->pk_nulls_first)
3764 606 : return;
3765 :
3766 : /* If eclass is volatile, no hope of using an indexscan */
3767 1046 : if (pathkey->pk_eclass->ec_has_volatile)
3768 0 : return;
3769 :
3770 : /*
3771 : * Try to match eclass member expression(s) to index. Note that child
3772 : * EC members are considered, but only when they belong to the target
3773 : * relation. (Unlike regular members, the same expression could be a
3774 : * child member of more than one EC. Therefore, the same index could
3775 : * be considered to match more than one pathkey list, which is OK
3776 : * here. See also get_eclass_for_sort_expr.)
3777 : */
3778 1046 : setup_eclass_member_iterator(&it, pathkey->pk_eclass,
3779 1046 : index->rel->relids);
3780 1650 : while ((member = eclass_member_iterator_next(&it)) != NULL)
3781 : {
3782 : int indexcol;
3783 :
3784 : /* No possibility of match if it references other relations */
3785 1078 : if (!bms_equal(member->em_relids, index->rel->relids))
3786 32 : continue;
3787 :
3788 : /*
3789 : * We allow any column of the index to match each pathkey; they
3790 : * don't have to match left-to-right as you might expect. This is
3791 : * correct for GiST, and it doesn't matter for SP-GiST because
3792 : * that doesn't handle multiple columns anyway, and no other
3793 : * existing AMs support amcanorderbyop. We might need different
3794 : * logic in future for other implementations.
3795 : */
3796 1906 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3797 : {
3798 : Expr *expr;
3799 :
3800 1334 : expr = match_clause_to_ordering_op(index,
3801 : indexcol,
3802 : member->em_expr,
3803 : pathkey->pk_opfamily);
3804 1334 : if (expr)
3805 : {
3806 474 : *orderby_clauses_p = lappend(*orderby_clauses_p, expr);
3807 474 : *clause_columns_p = lappend_int(*clause_columns_p, indexcol);
3808 474 : found = true;
3809 474 : break;
3810 : }
3811 : }
3812 :
3813 1046 : if (found) /* don't want to look at remaining members */
3814 474 : break;
3815 : }
3816 :
3817 : /*
3818 : * Return the matches found so far when this pathkey couldn't be
3819 : * matched to the index.
3820 : */
3821 1046 : if (!found)
3822 572 : return;
3823 : }
3824 : }
3825 :
3826 : /*
3827 : * match_clause_to_ordering_op
3828 : * Determines whether an ordering operator expression matches an
3829 : * index column.
3830 : *
3831 : * This is similar to, but simpler than, match_clause_to_indexcol.
3832 : * We only care about simple OpExpr cases. The input is a bare
3833 : * expression that is being ordered by, which must be of the form
3834 : * (indexkey op const) or (const op indexkey) where op is an ordering
3835 : * operator for the column's opfamily.
3836 : *
3837 : * 'index' is the index of interest.
3838 : * 'indexcol' is a column number of 'index' (counting from 0).
3839 : * 'clause' is the ordering expression to be tested.
3840 : * 'pk_opfamily' is the btree opfamily describing the required sort order.
3841 : *
3842 : * Note that we currently do not consider the collation of the ordering
3843 : * operator's result. In practical cases the result type will be numeric
3844 : * and thus have no collation, and it's not very clear what to match to
3845 : * if it did have a collation. The index's collation should match the
3846 : * ordering operator's input collation, not its result.
3847 : *
3848 : * If successful, return 'clause' as-is if the indexkey is on the left,
3849 : * otherwise a commuted copy of 'clause'. If no match, return NULL.
3850 : */
3851 : static Expr *
3852 1334 : match_clause_to_ordering_op(IndexOptInfo *index,
3853 : int indexcol,
3854 : Expr *clause,
3855 : Oid pk_opfamily)
3856 : {
3857 : Oid opfamily;
3858 : Oid idxcollation;
3859 : Node *leftop,
3860 : *rightop;
3861 : Oid expr_op;
3862 : Oid expr_coll;
3863 : Oid sortfamily;
3864 : bool commuted;
3865 :
3866 : Assert(indexcol < index->nkeycolumns);
3867 :
3868 1334 : opfamily = index->opfamily[indexcol];
3869 1334 : idxcollation = index->indexcollations[indexcol];
3870 :
3871 : /*
3872 : * Clause must be a binary opclause.
3873 : */
3874 1334 : if (!is_opclause(clause))
3875 860 : return NULL;
3876 474 : leftop = get_leftop(clause);
3877 474 : rightop = get_rightop(clause);
3878 474 : if (!leftop || !rightop)
3879 0 : return NULL;
3880 474 : expr_op = ((OpExpr *) clause)->opno;
3881 474 : expr_coll = ((OpExpr *) clause)->inputcollid;
3882 :
3883 : /*
3884 : * We can forget the whole thing right away if wrong collation.
3885 : */
3886 474 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3887 0 : return NULL;
3888 :
3889 : /*
3890 : * Check for clauses of the form: (indexkey operator constant) or
3891 : * (constant operator indexkey).
3892 : */
3893 474 : if (match_index_to_operand(leftop, indexcol, index) &&
3894 450 : !contain_var_clause(rightop) &&
3895 450 : !contain_volatile_functions(rightop))
3896 : {
3897 450 : commuted = false;
3898 : }
3899 24 : else if (match_index_to_operand(rightop, indexcol, index) &&
3900 24 : !contain_var_clause(leftop) &&
3901 24 : !contain_volatile_functions(leftop))
3902 : {
3903 : /* Might match, but we need a commuted operator */
3904 24 : expr_op = get_commutator(expr_op);
3905 24 : if (expr_op == InvalidOid)
3906 0 : return NULL;
3907 24 : commuted = true;
3908 : }
3909 : else
3910 0 : return NULL;
3911 :
3912 : /*
3913 : * Is the (commuted) operator an ordering operator for the opfamily? And
3914 : * if so, does it yield the right sorting semantics?
3915 : */
3916 474 : sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3917 474 : if (sortfamily != pk_opfamily)
3918 0 : return NULL;
3919 :
3920 : /* We have a match. Return clause or a commuted version thereof. */
3921 474 : if (commuted)
3922 : {
3923 24 : OpExpr *newclause = makeNode(OpExpr);
3924 :
3925 : /* flat-copy all the fields of clause */
3926 24 : memcpy(newclause, clause, sizeof(OpExpr));
3927 :
3928 : /* commute it */
3929 24 : newclause->opno = expr_op;
3930 24 : newclause->opfuncid = InvalidOid;
3931 24 : newclause->args = list_make2(rightop, leftop);
3932 :
3933 24 : clause = (Expr *) newclause;
3934 : }
3935 :
3936 474 : return clause;
3937 : }
3938 :
3939 :
3940 : /****************************************************************************
3941 : * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3942 : ****************************************************************************/
3943 :
3944 : /*
3945 : * check_index_predicates
3946 : * Set the predicate-derived IndexOptInfo fields for each index
3947 : * of the specified relation.
3948 : *
3949 : * predOK is set true if the index is partial and its predicate is satisfied
3950 : * for this query, ie the query's WHERE clauses imply the predicate.
3951 : *
3952 : * indrestrictinfo is set to the relation's baserestrictinfo list less any
3953 : * conditions that are implied by the index's predicate. (Obviously, for a
3954 : * non-partial index, this is the same as baserestrictinfo.) Such conditions
3955 : * can be dropped from the plan when using the index, in certain cases.
3956 : *
3957 : * At one time it was possible for this to get re-run after adding more
3958 : * restrictions to the rel, thus possibly letting us prove more indexes OK.
3959 : * That doesn't happen any more (at least not in the core code's usage),
3960 : * but this code still supports it in case extensions want to mess with the
3961 : * baserestrictinfo list. We assume that adding more restrictions can't make
3962 : * an index not predOK. We must recompute indrestrictinfo each time, though,
3963 : * to make sure any newly-added restrictions get into it if needed.
3964 : */
3965 : void
3966 404966 : check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3967 : {
3968 : List *clauselist;
3969 : bool have_partial;
3970 : bool is_target_rel;
3971 : Relids otherrels;
3972 : ListCell *lc;
3973 :
3974 : /* Indexes are available only on base or "other" member relations. */
3975 : Assert(IS_SIMPLE_REL(rel));
3976 :
3977 : /*
3978 : * Initialize the indrestrictinfo lists to be identical to
3979 : * baserestrictinfo, and check whether there are any partial indexes. If
3980 : * not, this is all we need to do.
3981 : */
3982 404966 : have_partial = false;
3983 1129710 : foreach(lc, rel->indexlist)
3984 : {
3985 724744 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3986 :
3987 724744 : index->indrestrictinfo = rel->baserestrictinfo;
3988 724744 : if (index->indpred)
3989 984 : have_partial = true;
3990 : }
3991 404966 : if (!have_partial)
3992 404306 : return;
3993 :
3994 : /*
3995 : * Construct a list of clauses that we can assume true for the purpose of
3996 : * proving the index(es) usable. Restriction clauses for the rel are
3997 : * always usable, and so are any join clauses that are "movable to" this
3998 : * rel. Also, we can consider any EC-derivable join clauses (which must
3999 : * be "movable to" this rel, by definition).
4000 : */
4001 660 : clauselist = list_copy(rel->baserestrictinfo);
4002 :
4003 : /* Scan the rel's join clauses */
4004 660 : foreach(lc, rel->joininfo)
4005 : {
4006 0 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4007 :
4008 : /* Check if clause can be moved to this rel */
4009 0 : if (!join_clause_is_movable_to(rinfo, rel))
4010 0 : continue;
4011 :
4012 0 : clauselist = lappend(clauselist, rinfo);
4013 : }
4014 :
4015 : /*
4016 : * Add on any equivalence-derivable join clauses. Computing the correct
4017 : * relid sets for generate_join_implied_equalities is slightly tricky
4018 : * because the rel could be a child rel rather than a true baserel, and in
4019 : * that case we must subtract its parents' relid(s) from all_query_rels.
4020 : * Additionally, we mustn't consider clauses that are only computable
4021 : * after outer joins that can null the rel.
4022 : */
4023 660 : if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
4024 72 : otherrels = bms_difference(root->all_query_rels,
4025 72 : find_childrel_parents(root, rel));
4026 : else
4027 588 : otherrels = bms_difference(root->all_query_rels, rel->relids);
4028 660 : otherrels = bms_del_members(otherrels, rel->nulling_relids);
4029 :
4030 660 : if (!bms_is_empty(otherrels))
4031 : clauselist =
4032 88 : list_concat(clauselist,
4033 88 : generate_join_implied_equalities(root,
4034 88 : bms_union(rel->relids,
4035 : otherrels),
4036 : otherrels,
4037 : rel,
4038 : NULL));
4039 :
4040 : /*
4041 : * Normally we remove quals that are implied by a partial index's
4042 : * predicate from indrestrictinfo, indicating that they need not be
4043 : * checked explicitly by an indexscan plan using this index. However, if
4044 : * the rel is a target relation of UPDATE/DELETE/MERGE/SELECT FOR UPDATE,
4045 : * we cannot remove such quals from the plan, because they need to be in
4046 : * the plan so that they will be properly rechecked by EvalPlanQual
4047 : * testing. Some day we might want to remove such quals from the main
4048 : * plan anyway and pass them through to EvalPlanQual via a side channel;
4049 : * but for now, we just don't remove implied quals at all for target
4050 : * relations.
4051 : */
4052 1208 : is_target_rel = (bms_is_member(rel->relid, root->all_result_relids) ||
4053 548 : get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
4054 :
4055 : /*
4056 : * Now try to prove each index predicate true, and compute the
4057 : * indrestrictinfo lists for partial indexes. Note that we compute the
4058 : * indrestrictinfo list even for non-predOK indexes; this might seem
4059 : * wasteful, but we may be able to use such indexes in OR clauses, cf
4060 : * generate_bitmap_or_paths().
4061 : */
4062 2030 : foreach(lc, rel->indexlist)
4063 : {
4064 1370 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
4065 : ListCell *lcr;
4066 :
4067 1370 : if (index->indpred == NIL)
4068 386 : continue; /* ignore non-partial indexes here */
4069 :
4070 984 : if (!index->predOK) /* don't repeat work if already proven OK */
4071 984 : index->predOK = predicate_implied_by(index->indpred, clauselist,
4072 : false);
4073 :
4074 : /* If rel is an update target, leave indrestrictinfo as set above */
4075 984 : if (is_target_rel)
4076 172 : continue;
4077 :
4078 : /* Else compute indrestrictinfo as the non-implied quals */
4079 812 : index->indrestrictinfo = NIL;
4080 1914 : foreach(lcr, rel->baserestrictinfo)
4081 : {
4082 1102 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
4083 :
4084 : /* predicate_implied_by() assumes first arg is immutable */
4085 1102 : if (contain_mutable_functions((Node *) rinfo->clause) ||
4086 1102 : !predicate_implied_by(list_make1(rinfo->clause),
4087 : index->indpred, false))
4088 782 : index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
4089 : }
4090 : }
4091 : }
4092 :
4093 : /****************************************************************************
4094 : * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
4095 : ****************************************************************************/
4096 :
4097 : /*
4098 : * ec_member_matches_indexcol
4099 : * Test whether an EquivalenceClass member matches an index column.
4100 : *
4101 : * This is a callback for use by generate_implied_equalities_for_column.
4102 : */
4103 : static bool
4104 425338 : ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
4105 : EquivalenceClass *ec, EquivalenceMember *em,
4106 : void *arg)
4107 : {
4108 425338 : IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
4109 425338 : int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
4110 : Oid curFamily;
4111 : Oid curCollation;
4112 :
4113 : Assert(indexcol < index->nkeycolumns);
4114 :
4115 425338 : curFamily = index->opfamily[indexcol];
4116 425338 : curCollation = index->indexcollations[indexcol];
4117 :
4118 : /*
4119 : * If it's a btree index, we can reject it if its opfamily isn't
4120 : * compatible with the EC, since no clause generated from the EC could be
4121 : * used with the index. For non-btree indexes, we can't easily tell
4122 : * whether clauses generated from the EC could be used with the index, so
4123 : * don't check the opfamily. This might mean we return "true" for a
4124 : * useless EC, so we have to recheck the results of
4125 : * generate_implied_equalities_for_column; see
4126 : * match_eclass_clauses_to_index.
4127 : */
4128 425338 : if (index->relam == BTREE_AM_OID &&
4129 425296 : !list_member_oid(ec->ec_opfamilies, curFamily))
4130 129520 : return false;
4131 :
4132 : /* We insist on collation match for all index types, though */
4133 295818 : if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
4134 18 : return false;
4135 :
4136 295800 : return match_index_to_operand((Node *) em->em_expr, indexcol, index);
4137 : }
4138 :
4139 : /*
4140 : * relation_has_unique_index_for
4141 : * Determine whether the relation provably has at most one row satisfying
4142 : * a set of equality conditions, because the conditions constrain all
4143 : * columns of some unique index.
4144 : *
4145 : * The conditions can be represented in either or both of two ways:
4146 : * 1. A list of RestrictInfo nodes, where the caller has already determined
4147 : * that each condition is a mergejoinable equality with an expression in
4148 : * this relation on one side, and an expression not involving this relation
4149 : * on the other. The transient outer_is_left flag is used to identify which
4150 : * side we should look at: left side if outer_is_left is false, right side
4151 : * if it is true.
4152 : * 2. A list of expressions in this relation, and a corresponding list of
4153 : * equality operators. The caller must have already checked that the operators
4154 : * represent equality. (Note: the operators could be cross-type; the
4155 : * expressions should correspond to their RHS inputs.)
4156 : *
4157 : * The caller need only supply equality conditions arising from joins;
4158 : * this routine automatically adds in any usable baserestrictinfo clauses.
4159 : * (Note that the passed-in restrictlist will be destructively modified!)
4160 : */
4161 : bool
4162 936 : relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
4163 : List *restrictlist,
4164 : List *exprlist, List *oprlist)
4165 : {
4166 936 : return relation_has_unique_index_ext(root, rel, restrictlist,
4167 : exprlist, oprlist, NULL);
4168 : }
4169 :
4170 : /*
4171 : * relation_has_unique_index_ext
4172 : * Same as relation_has_unique_index_for(), but supports extra_clauses
4173 : * parameter. If extra_clauses isn't NULL, return baserestrictinfo clauses
4174 : * which were used to derive uniqueness.
4175 : */
4176 : bool
4177 206120 : relation_has_unique_index_ext(PlannerInfo *root, RelOptInfo *rel,
4178 : List *restrictlist,
4179 : List *exprlist, List *oprlist,
4180 : List **extra_clauses)
4181 : {
4182 : ListCell *ic;
4183 :
4184 : Assert(list_length(exprlist) == list_length(oprlist));
4185 :
4186 : /* Short-circuit if no indexes... */
4187 206120 : if (rel->indexlist == NIL)
4188 466 : return false;
4189 :
4190 : /*
4191 : * Examine the rel's restriction clauses for usable var = const clauses
4192 : * that we can add to the restrictlist.
4193 : */
4194 346552 : foreach(ic, rel->baserestrictinfo)
4195 : {
4196 140898 : RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
4197 :
4198 : /*
4199 : * Note: can_join won't be set for a restriction clause, but
4200 : * mergeopfamilies will be if it has a mergejoinable operator and
4201 : * doesn't contain volatile functions.
4202 : */
4203 140898 : if (restrictinfo->mergeopfamilies == NIL)
4204 59170 : continue; /* not mergejoinable */
4205 :
4206 : /*
4207 : * The clause certainly doesn't refer to anything but the given rel.
4208 : * If either side is pseudoconstant then we can use it.
4209 : */
4210 81728 : if (bms_is_empty(restrictinfo->left_relids))
4211 : {
4212 : /* righthand side is inner */
4213 58 : restrictinfo->outer_is_left = true;
4214 : }
4215 81670 : else if (bms_is_empty(restrictinfo->right_relids))
4216 : {
4217 : /* lefthand side is inner */
4218 81544 : restrictinfo->outer_is_left = false;
4219 : }
4220 : else
4221 126 : continue;
4222 :
4223 : /* OK, add to list */
4224 81602 : restrictlist = lappend(restrictlist, restrictinfo);
4225 : }
4226 :
4227 : /* Short-circuit the easy case */
4228 205654 : if (restrictlist == NIL && exprlist == NIL)
4229 994 : return false;
4230 :
4231 : /* Examine each index of the relation ... */
4232 541152 : foreach(ic, rel->indexlist)
4233 : {
4234 453724 : IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
4235 : int c;
4236 453724 : List *exprs = NIL;
4237 :
4238 : /*
4239 : * If the index is not unique, or not immediately enforced, or if it's
4240 : * a partial index, it's useless here. We're unable to make use of
4241 : * predOK partial unique indexes due to the fact that
4242 : * check_index_predicates() also makes use of join predicates to
4243 : * determine if the partial index is usable. Here we need proofs that
4244 : * hold true before any joins are evaluated.
4245 : */
4246 453724 : if (!ind->unique || !ind->immediate || ind->indpred != NIL)
4247 133174 : continue;
4248 :
4249 : /*
4250 : * Try to find each index column in the lists of conditions. This is
4251 : * O(N^2) or worse, but we expect all the lists to be short.
4252 : */
4253 520676 : for (c = 0; c < ind->nkeycolumns; c++)
4254 : {
4255 403444 : bool matched = false;
4256 : ListCell *lc;
4257 : ListCell *lc2;
4258 :
4259 776934 : foreach(lc, restrictlist)
4260 : {
4261 573616 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4262 : Node *rexpr;
4263 :
4264 : /*
4265 : * The condition's equality operator must be a member of the
4266 : * index opfamily, else it is not asserting the right kind of
4267 : * equality behavior for this index. We check this first
4268 : * since it's probably cheaper than match_index_to_operand().
4269 : */
4270 573616 : if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
4271 161428 : continue;
4272 :
4273 : /*
4274 : * XXX at some point we may need to check collations here too.
4275 : * For the moment we assume all collations reduce to the same
4276 : * notion of equality.
4277 : */
4278 :
4279 : /* OK, see if the condition operand matches the index key */
4280 412188 : if (rinfo->outer_is_left)
4281 177432 : rexpr = get_rightop(rinfo->clause);
4282 : else
4283 234756 : rexpr = get_leftop(rinfo->clause);
4284 :
4285 412188 : if (match_index_to_operand(rexpr, c, ind))
4286 : {
4287 200126 : matched = true; /* column is unique */
4288 :
4289 200126 : if (bms_membership(rinfo->clause_relids) == BMS_SINGLETON)
4290 : {
4291 : MemoryContext oldMemCtx =
4292 49304 : MemoryContextSwitchTo(root->planner_cxt);
4293 :
4294 : /*
4295 : * Add filter clause into a list allowing caller to
4296 : * know if uniqueness have made not only by join
4297 : * clauses.
4298 : */
4299 : Assert(bms_is_empty(rinfo->left_relids) ||
4300 : bms_is_empty(rinfo->right_relids));
4301 49304 : if (extra_clauses)
4302 144 : exprs = lappend(exprs, rinfo);
4303 49304 : MemoryContextSwitchTo(oldMemCtx);
4304 : }
4305 :
4306 200126 : break;
4307 : }
4308 : }
4309 :
4310 403444 : if (matched)
4311 200126 : continue;
4312 :
4313 203476 : forboth(lc, exprlist, lc2, oprlist)
4314 : {
4315 158 : Node *expr = (Node *) lfirst(lc);
4316 158 : Oid opr = lfirst_oid(lc2);
4317 :
4318 : /* See if the expression matches the index key */
4319 158 : if (!match_index_to_operand(expr, c, ind))
4320 158 : continue;
4321 :
4322 : /*
4323 : * The equality operator must be a member of the index
4324 : * opfamily, else it is not asserting the right kind of
4325 : * equality behavior for this index. We assume the caller
4326 : * determined it is an equality operator, so we don't need to
4327 : * check any more tightly than this.
4328 : */
4329 0 : if (!op_in_opfamily(opr, ind->opfamily[c]))
4330 0 : continue;
4331 :
4332 : /*
4333 : * XXX at some point we may need to check collations here too.
4334 : * For the moment we assume all collations reduce to the same
4335 : * notion of equality.
4336 : */
4337 :
4338 0 : matched = true; /* column is unique */
4339 0 : break;
4340 : }
4341 :
4342 203318 : if (!matched)
4343 203318 : break; /* no match; this index doesn't help us */
4344 : }
4345 :
4346 : /* Matched all key columns of this index? */
4347 320550 : if (c == ind->nkeycolumns)
4348 : {
4349 117232 : if (extra_clauses)
4350 654 : *extra_clauses = exprs;
4351 117232 : return true;
4352 : }
4353 : }
4354 :
4355 87428 : return false;
4356 : }
4357 :
4358 : /*
4359 : * indexcol_is_bool_constant_for_query
4360 : *
4361 : * If an index column is constrained to have a constant value by the query's
4362 : * WHERE conditions, then it's irrelevant for sort-order considerations.
4363 : * Usually that means we have a restriction clause WHERE indexcol = constant,
4364 : * which gets turned into an EquivalenceClass containing a constant, which
4365 : * is recognized as redundant by build_index_pathkeys(). But if the index
4366 : * column is a boolean variable (or expression), then we are not going to
4367 : * see WHERE indexcol = constant, because expression preprocessing will have
4368 : * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
4369 : * going to have a matching EquivalenceClass (unless the query also contains
4370 : * "ORDER BY indexcol"). To allow such cases to work the same as they would
4371 : * for non-boolean values, this function is provided to detect whether the
4372 : * specified index column matches a boolean restriction clause.
4373 : */
4374 : bool
4375 646284 : indexcol_is_bool_constant_for_query(PlannerInfo *root,
4376 : IndexOptInfo *index,
4377 : int indexcol)
4378 : {
4379 : ListCell *lc;
4380 :
4381 : /* If the index isn't boolean, we can't possibly get a match */
4382 646284 : if (!IsBooleanOpfamily(index->opfamily[indexcol]))
4383 641784 : return false;
4384 :
4385 : /* Check each restriction clause for the index's rel */
4386 4536 : foreach(lc, index->rel->baserestrictinfo)
4387 : {
4388 1260 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4389 :
4390 : /*
4391 : * As in match_clause_to_indexcol, never match pseudoconstants to
4392 : * indexes. (It might be semantically okay to do so here, but the
4393 : * odds of getting a match are negligible, so don't waste the cycles.)
4394 : */
4395 1260 : if (rinfo->pseudoconstant)
4396 0 : continue;
4397 :
4398 : /* See if we can match the clause's expression to the index column */
4399 1260 : if (match_boolean_index_clause(root, rinfo, indexcol, index))
4400 1224 : return true;
4401 : }
4402 :
4403 3276 : return false;
4404 : }
4405 :
4406 :
4407 : /****************************************************************************
4408 : * ---- ROUTINES TO CHECK OPERANDS ----
4409 : ****************************************************************************/
4410 :
4411 : /*
4412 : * match_index_to_operand()
4413 : * Generalized test for a match between an index's key
4414 : * and the operand on one side of a restriction or join clause.
4415 : *
4416 : * operand: the nodetree to be compared to the index
4417 : * indexcol: the column number of the index (counting from 0)
4418 : * index: the index of interest
4419 : *
4420 : * Note that we aren't interested in collations here; the caller must check
4421 : * for a collation match, if it's dealing with an operator where that matters.
4422 : *
4423 : * This is exported for use in selfuncs.c.
4424 : */
4425 : bool
4426 3730602 : match_index_to_operand(Node *operand,
4427 : int indexcol,
4428 : IndexOptInfo *index)
4429 : {
4430 : int indkey;
4431 :
4432 : /*
4433 : * Ignore any RelabelType node above the operand. This is needed to be
4434 : * able to apply indexscanning in binary-compatible-operator cases. Note:
4435 : * we can assume there is at most one RelabelType node;
4436 : * eval_const_expressions() will have simplified if more than one.
4437 : */
4438 3730602 : if (operand && IsA(operand, RelabelType))
4439 23898 : operand = (Node *) ((RelabelType *) operand)->arg;
4440 :
4441 3730602 : indkey = index->indexkeys[indexcol];
4442 3730602 : if (indkey != 0)
4443 : {
4444 : /*
4445 : * Simple index column; operand must be a matching Var.
4446 : */
4447 3724568 : if (operand && IsA(operand, Var) &&
4448 2740358 : index->rel->relid == ((Var *) operand)->varno &&
4449 2545024 : indkey == ((Var *) operand)->varattno &&
4450 859446 : ((Var *) operand)->varnullingrels == NULL)
4451 858520 : return true;
4452 : }
4453 : else
4454 : {
4455 : /*
4456 : * Index expression; find the correct expression. (This search could
4457 : * be avoided, at the cost of complicating all the callers of this
4458 : * routine; doesn't seem worth it.)
4459 : */
4460 : ListCell *indexpr_item;
4461 : int i;
4462 : Node *indexkey;
4463 :
4464 6034 : indexpr_item = list_head(index->indexprs);
4465 6034 : for (i = 0; i < indexcol; i++)
4466 : {
4467 0 : if (index->indexkeys[i] == 0)
4468 : {
4469 0 : if (indexpr_item == NULL)
4470 0 : elog(ERROR, "wrong number of index expressions");
4471 0 : indexpr_item = lnext(index->indexprs, indexpr_item);
4472 : }
4473 : }
4474 6034 : if (indexpr_item == NULL)
4475 0 : elog(ERROR, "wrong number of index expressions");
4476 6034 : indexkey = (Node *) lfirst(indexpr_item);
4477 :
4478 : /*
4479 : * Does it match the operand? Again, strip any relabeling.
4480 : */
4481 6034 : if (indexkey && IsA(indexkey, RelabelType))
4482 10 : indexkey = (Node *) ((RelabelType *) indexkey)->arg;
4483 :
4484 6034 : if (equal(indexkey, operand))
4485 2164 : return true;
4486 : }
4487 :
4488 2869918 : return false;
4489 : }
4490 :
4491 : /*
4492 : * is_pseudo_constant_for_index()
4493 : * Test whether the given expression can be used as an indexscan
4494 : * comparison value.
4495 : *
4496 : * An indexscan comparison value must not contain any volatile functions,
4497 : * and it can't contain any Vars of the index's own table. Vars of
4498 : * other tables are okay, though; in that case we'd be producing an
4499 : * indexqual usable in a parameterized indexscan. This is, therefore,
4500 : * a weaker condition than is_pseudo_constant_clause().
4501 : *
4502 : * This function is exported for use by planner support functions,
4503 : * which will have available the IndexOptInfo, but not any RestrictInfo
4504 : * infrastructure. It is making the same test made by functions above
4505 : * such as match_opclause_to_indexcol(), but those rely where possible
4506 : * on RestrictInfo information about variable membership.
4507 : *
4508 : * expr: the nodetree to be checked
4509 : * index: the index of interest
4510 : */
4511 : bool
4512 0 : is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
4513 : {
4514 : /* pull_varnos is cheaper than volatility check, so do that first */
4515 0 : if (bms_is_member(index->rel->relid, pull_varnos(root, expr)))
4516 0 : return false; /* no good, contains Var of table */
4517 0 : if (contain_volatile_functions(expr))
4518 0 : return false; /* no good, volatile comparison value */
4519 0 : return true;
4520 : }
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