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) 1996-2019, 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_operator.h"
24 : #include "catalog/pg_opfamily.h"
25 : #include "catalog/pg_type.h"
26 : #include "nodes/makefuncs.h"
27 : #include "nodes/nodeFuncs.h"
28 : #include "nodes/supportnodes.h"
29 : #include "optimizer/cost.h"
30 : #include "optimizer/optimizer.h"
31 : #include "optimizer/pathnode.h"
32 : #include "optimizer/paths.h"
33 : #include "optimizer/prep.h"
34 : #include "optimizer/restrictinfo.h"
35 : #include "utils/lsyscache.h"
36 : #include "utils/selfuncs.h"
37 :
38 :
39 : /* XXX see PartCollMatchesExprColl */
40 : #define IndexCollMatchesExprColl(idxcollation, exprcollation) \
41 : ((idxcollation) == InvalidOid || (idxcollation) == (exprcollation))
42 :
43 : /* Whether we are looking for plain indexscan, bitmap scan, or either */
44 : typedef enum
45 : {
46 : ST_INDEXSCAN, /* must support amgettuple */
47 : ST_BITMAPSCAN, /* must support amgetbitmap */
48 : ST_ANYSCAN /* either is okay */
49 : } ScanTypeControl;
50 :
51 : /* Data structure for collecting qual clauses that match an index */
52 : typedef struct
53 : {
54 : bool nonempty; /* True if lists are not all empty */
55 : /* Lists of IndexClause nodes, one list per index column */
56 : List *indexclauses[INDEX_MAX_KEYS];
57 : } IndexClauseSet;
58 :
59 : /* Per-path data used within choose_bitmap_and() */
60 : typedef struct
61 : {
62 : Path *path; /* IndexPath, BitmapAndPath, or BitmapOrPath */
63 : List *quals; /* the WHERE clauses it uses */
64 : List *preds; /* predicates of its partial index(es) */
65 : Bitmapset *clauseids; /* quals+preds represented as a bitmapset */
66 : bool unclassifiable; /* has too many quals+preds to process? */
67 : } PathClauseUsage;
68 :
69 : /* Callback argument for ec_member_matches_indexcol */
70 : typedef struct
71 : {
72 : IndexOptInfo *index; /* index we're considering */
73 : int indexcol; /* index column we want to match to */
74 : } ec_member_matches_arg;
75 :
76 :
77 : static void consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
78 : IndexOptInfo *index,
79 : IndexClauseSet *rclauseset,
80 : IndexClauseSet *jclauseset,
81 : IndexClauseSet *eclauseset,
82 : List **bitindexpaths);
83 : static void consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
84 : IndexOptInfo *index,
85 : IndexClauseSet *rclauseset,
86 : IndexClauseSet *jclauseset,
87 : IndexClauseSet *eclauseset,
88 : List **bitindexpaths,
89 : List *indexjoinclauses,
90 : int considered_clauses,
91 : List **considered_relids);
92 : static void get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
93 : IndexOptInfo *index,
94 : IndexClauseSet *rclauseset,
95 : IndexClauseSet *jclauseset,
96 : IndexClauseSet *eclauseset,
97 : List **bitindexpaths,
98 : Relids relids,
99 : List **considered_relids);
100 : static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
101 : List *indexjoinclauses);
102 : static bool bms_equal_any(Relids relids, List *relids_list);
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 : bool *skip_lower_saop);
112 : static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
113 : List *clauses, List *other_clauses);
114 : static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
115 : List *clauses, List *other_clauses);
116 : static Path *choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel,
117 : List *paths);
118 : static int path_usage_comparator(const void *a, const void *b);
119 : static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel,
120 : Path *ipath);
121 : static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel,
122 : List *paths);
123 : static PathClauseUsage *classify_index_clause_usage(Path *path,
124 : List **clauselist);
125 : static Relids get_bitmap_tree_required_outer(Path *bitmapqual);
126 : static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds);
127 : static int find_list_position(Node *node, List **nodelist);
128 : static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index);
129 : static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids);
130 : static double adjust_rowcount_for_semijoins(PlannerInfo *root,
131 : Index cur_relid,
132 : Index outer_relid,
133 : double rowcount);
134 : static double approximate_joinrel_size(PlannerInfo *root, Relids relids);
135 : static void match_restriction_clauses_to_index(PlannerInfo *root,
136 : IndexOptInfo *index,
137 : IndexClauseSet *clauseset);
138 : static void match_join_clauses_to_index(PlannerInfo *root,
139 : RelOptInfo *rel, IndexOptInfo *index,
140 : IndexClauseSet *clauseset,
141 : List **joinorclauses);
142 : static void match_eclass_clauses_to_index(PlannerInfo *root,
143 : IndexOptInfo *index,
144 : IndexClauseSet *clauseset);
145 : static void match_clauses_to_index(PlannerInfo *root,
146 : List *clauses,
147 : IndexOptInfo *index,
148 : IndexClauseSet *clauseset);
149 : static void match_clause_to_index(PlannerInfo *root,
150 : RestrictInfo *rinfo,
151 : IndexOptInfo *index,
152 : IndexClauseSet *clauseset);
153 : static IndexClause *match_clause_to_indexcol(PlannerInfo *root,
154 : RestrictInfo *rinfo,
155 : int indexcol,
156 : IndexOptInfo *index);
157 : static IndexClause *match_boolean_index_clause(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(RestrictInfo *rinfo,
174 : int indexcol,
175 : IndexOptInfo *index);
176 : static IndexClause *match_rowcompare_to_indexcol(RestrictInfo *rinfo,
177 : int indexcol,
178 : IndexOptInfo *index);
179 : static IndexClause *expand_indexqual_rowcompare(RestrictInfo *rinfo,
180 : int indexcol,
181 : IndexOptInfo *index,
182 : Oid expr_op,
183 : bool var_on_left);
184 : static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
185 : List **orderby_clauses_p,
186 : List **clause_columns_p);
187 : static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
188 : int indexcol, Expr *clause, Oid pk_opfamily);
189 : static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
190 : EquivalenceClass *ec, EquivalenceMember *em,
191 : void *arg);
192 :
193 :
194 : /*
195 : * create_index_paths()
196 : * Generate all interesting index paths for the given relation.
197 : * Candidate paths are added to the rel's pathlist (using add_path).
198 : *
199 : * To be considered for an index scan, an index must match one or more
200 : * restriction clauses or join clauses from the query's qual condition,
201 : * or match the query's ORDER BY condition, or have a predicate that
202 : * matches the query's qual condition.
203 : *
204 : * There are two basic kinds of index scans. A "plain" index scan uses
205 : * only restriction clauses (possibly none at all) in its indexqual,
206 : * so it can be applied in any context. A "parameterized" index scan uses
207 : * join clauses (plus restriction clauses, if available) in its indexqual.
208 : * When joining such a scan to one of the relations supplying the other
209 : * variables used in its indexqual, the parameterized scan must appear as
210 : * the inner relation of a nestloop join; it can't be used on the outer side,
211 : * nor in a merge or hash join. In that context, values for the other rels'
212 : * attributes are available and fixed during any one scan of the indexpath.
213 : *
214 : * An IndexPath is generated and submitted to add_path() for each plain or
215 : * parameterized index scan this routine deems potentially interesting for
216 : * the current query.
217 : *
218 : * 'rel' is the relation for which we want to generate index paths
219 : *
220 : * Note: check_index_predicates() must have been run previously for this rel.
221 : *
222 : * Note: in cases involving LATERAL references in the relation's tlist, it's
223 : * possible that rel->lateral_relids is nonempty. Currently, we include
224 : * lateral_relids into the parameterization reported for each path, but don't
225 : * take it into account otherwise. The fact that any such rels *must* be
226 : * available as parameter sources perhaps should influence our choices of
227 : * index quals ... but for now, it doesn't seem worth troubling over.
228 : * In particular, comments below about "unparameterized" paths should be read
229 : * as meaning "unparameterized so far as the indexquals are concerned".
230 : */
231 : void
232 216944 : create_index_paths(PlannerInfo *root, RelOptInfo *rel)
233 : {
234 : List *indexpaths;
235 : List *bitindexpaths;
236 : List *bitjoinpaths;
237 : List *joinorclauses;
238 : IndexClauseSet rclauseset;
239 : IndexClauseSet jclauseset;
240 : IndexClauseSet eclauseset;
241 : ListCell *lc;
242 :
243 : /* Skip the whole mess if no indexes */
244 216944 : if (rel->indexlist == NIL)
245 37618 : return;
246 :
247 : /* Bitmap paths are collected and then dealt with at the end */
248 179326 : bitindexpaths = bitjoinpaths = joinorclauses = NIL;
249 :
250 : /* Examine each index in turn */
251 553638 : foreach(lc, rel->indexlist)
252 : {
253 374312 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
254 :
255 : /* Protect limited-size array in IndexClauseSets */
256 : Assert(index->nkeycolumns <= INDEX_MAX_KEYS);
257 :
258 : /*
259 : * Ignore partial indexes that do not match the query.
260 : * (generate_bitmap_or_paths() might be able to do something with
261 : * them, but that's of no concern here.)
262 : */
263 374312 : if (index->indpred != NIL && !index->predOK)
264 330 : continue;
265 :
266 : /*
267 : * Identify the restriction clauses that can match the index.
268 : */
269 373982 : MemSet(&rclauseset, 0, sizeof(rclauseset));
270 373982 : match_restriction_clauses_to_index(root, index, &rclauseset);
271 :
272 : /*
273 : * Build index paths from the restriction clauses. These will be
274 : * non-parameterized paths. Plain paths go directly to add_path(),
275 : * bitmap paths are added to bitindexpaths to be handled below.
276 : */
277 373982 : get_index_paths(root, rel, index, &rclauseset,
278 : &bitindexpaths);
279 :
280 : /*
281 : * Identify the join clauses that can match the index. For the moment
282 : * we keep them separate from the restriction clauses. Note that this
283 : * step finds only "loose" join clauses that have not been merged into
284 : * EquivalenceClasses. Also, collect join OR clauses for later.
285 : */
286 373982 : MemSet(&jclauseset, 0, sizeof(jclauseset));
287 373982 : match_join_clauses_to_index(root, rel, index,
288 : &jclauseset, &joinorclauses);
289 :
290 : /*
291 : * Look for EquivalenceClasses that can generate joinclauses matching
292 : * the index.
293 : */
294 373982 : MemSet(&eclauseset, 0, sizeof(eclauseset));
295 373982 : match_eclass_clauses_to_index(root, index,
296 : &eclauseset);
297 :
298 : /*
299 : * If we found any plain or eclass join clauses, build parameterized
300 : * index paths using them.
301 : */
302 373982 : if (jclauseset.nonempty || eclauseset.nonempty)
303 59106 : consider_index_join_clauses(root, rel, index,
304 : &rclauseset,
305 : &jclauseset,
306 : &eclauseset,
307 : &bitjoinpaths);
308 : }
309 :
310 : /*
311 : * Generate BitmapOrPaths for any suitable OR-clauses present in the
312 : * restriction list. Add these to bitindexpaths.
313 : */
314 179326 : indexpaths = generate_bitmap_or_paths(root, rel,
315 : rel->baserestrictinfo, NIL);
316 179326 : bitindexpaths = list_concat(bitindexpaths, indexpaths);
317 :
318 : /*
319 : * Likewise, generate BitmapOrPaths for any suitable OR-clauses present in
320 : * the joinclause list. Add these to bitjoinpaths.
321 : */
322 179326 : indexpaths = generate_bitmap_or_paths(root, rel,
323 : joinorclauses, rel->baserestrictinfo);
324 179326 : bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
325 :
326 : /*
327 : * If we found anything usable, generate a BitmapHeapPath for the most
328 : * promising combination of restriction bitmap index paths. Note there
329 : * will be only one such path no matter how many indexes exist. This
330 : * should be sufficient since there's basically only one figure of merit
331 : * (total cost) for such a path.
332 : */
333 179326 : if (bitindexpaths != NIL)
334 : {
335 : Path *bitmapqual;
336 : BitmapHeapPath *bpath;
337 :
338 113504 : bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
339 113504 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
340 : rel->lateral_relids, 1.0, 0);
341 113504 : add_path(rel, (Path *) bpath);
342 :
343 : /* create a partial bitmap heap path */
344 113504 : if (rel->consider_parallel && rel->lateral_relids == NULL)
345 71860 : create_partial_bitmap_paths(root, rel, bitmapqual);
346 : }
347 :
348 : /*
349 : * Likewise, if we found anything usable, generate BitmapHeapPaths for the
350 : * most promising combinations of join bitmap index paths. Our strategy
351 : * is to generate one such path for each distinct parameterization seen
352 : * among the available bitmap index paths. This may look pretty
353 : * expensive, but usually there won't be very many distinct
354 : * parameterizations. (This logic is quite similar to that in
355 : * consider_index_join_clauses, but we're working with whole paths not
356 : * individual clauses.)
357 : */
358 179326 : if (bitjoinpaths != NIL)
359 : {
360 : List *path_outer;
361 : List *all_path_outers;
362 : ListCell *lc;
363 :
364 : /*
365 : * path_outer holds the parameterization of each path in bitjoinpaths
366 : * (to save recalculating that several times), while all_path_outers
367 : * holds all distinct parameterization sets.
368 : */
369 56572 : path_outer = all_path_outers = NIL;
370 117530 : foreach(lc, bitjoinpaths)
371 : {
372 60958 : Path *path = (Path *) lfirst(lc);
373 : Relids required_outer;
374 :
375 60958 : required_outer = get_bitmap_tree_required_outer(path);
376 60958 : path_outer = lappend(path_outer, required_outer);
377 60958 : if (!bms_equal_any(required_outer, all_path_outers))
378 59616 : all_path_outers = lappend(all_path_outers, required_outer);
379 : }
380 :
381 : /* Now, for each distinct parameterization set ... */
382 116188 : foreach(lc, all_path_outers)
383 : {
384 59616 : Relids max_outers = (Relids) lfirst(lc);
385 : List *this_path_set;
386 : Path *bitmapqual;
387 : Relids required_outer;
388 : double loop_count;
389 : BitmapHeapPath *bpath;
390 : ListCell *lcp;
391 : ListCell *lco;
392 :
393 : /* Identify all the bitmap join paths needing no more than that */
394 59616 : this_path_set = NIL;
395 128214 : forboth(lcp, bitjoinpaths, lco, path_outer)
396 : {
397 68598 : Path *path = (Path *) lfirst(lcp);
398 68598 : Relids p_outers = (Relids) lfirst(lco);
399 :
400 68598 : if (bms_is_subset(p_outers, max_outers))
401 61358 : this_path_set = lappend(this_path_set, path);
402 : }
403 :
404 : /*
405 : * Add in restriction bitmap paths, since they can be used
406 : * together with any join paths.
407 : */
408 59616 : this_path_set = list_concat(this_path_set, bitindexpaths);
409 :
410 : /* Select best AND combination for this parameterization */
411 59616 : bitmapqual = choose_bitmap_and(root, rel, this_path_set);
412 :
413 : /* And push that path into the mix */
414 59616 : required_outer = get_bitmap_tree_required_outer(bitmapqual);
415 59616 : loop_count = get_loop_count(root, rel->relid, required_outer);
416 59616 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
417 : required_outer, loop_count, 0);
418 59616 : add_path(rel, (Path *) bpath);
419 : }
420 : }
421 : }
422 :
423 : /*
424 : * consider_index_join_clauses
425 : * Given sets of join clauses for an index, decide which parameterized
426 : * index paths to build.
427 : *
428 : * Plain indexpaths are sent directly to add_path, while potential
429 : * bitmap indexpaths are added to *bitindexpaths for later processing.
430 : *
431 : * 'rel' is the index's heap relation
432 : * 'index' is the index for which we want to generate paths
433 : * 'rclauseset' is the collection of indexable restriction clauses
434 : * 'jclauseset' is the collection of indexable simple join clauses
435 : * 'eclauseset' is the collection of indexable clauses from EquivalenceClasses
436 : * '*bitindexpaths' is the list to add bitmap paths to
437 : */
438 : static void
439 59106 : consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
440 : IndexOptInfo *index,
441 : IndexClauseSet *rclauseset,
442 : IndexClauseSet *jclauseset,
443 : IndexClauseSet *eclauseset,
444 : List **bitindexpaths)
445 : {
446 59106 : int considered_clauses = 0;
447 59106 : List *considered_relids = NIL;
448 : int indexcol;
449 :
450 : /*
451 : * The strategy here is to identify every potentially useful set of outer
452 : * rels that can provide indexable join clauses. For each such set,
453 : * select all the join clauses available from those outer rels, add on all
454 : * the indexable restriction clauses, and generate plain and/or bitmap
455 : * index paths for that set of clauses. This is based on the assumption
456 : * that it's always better to apply a clause as an indexqual than as a
457 : * filter (qpqual); which is where an available clause would end up being
458 : * applied if we omit it from the indexquals.
459 : *
460 : * This looks expensive, but in most practical cases there won't be very
461 : * many distinct sets of outer rels to consider. As a safety valve when
462 : * that's not true, we use a heuristic: limit the number of outer rel sets
463 : * considered to a multiple of the number of clauses considered. (We'll
464 : * always consider using each individual join clause, though.)
465 : *
466 : * For simplicity in selecting relevant clauses, we represent each set of
467 : * outer rels as a maximum set of clause_relids --- that is, the indexed
468 : * relation itself is also included in the relids set. considered_relids
469 : * lists all relids sets we've already tried.
470 : */
471 147140 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
472 : {
473 : /* Consider each applicable simple join clause */
474 88034 : considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
475 88034 : consider_index_join_outer_rels(root, rel, index,
476 : rclauseset, jclauseset, eclauseset,
477 : bitindexpaths,
478 : jclauseset->indexclauses[indexcol],
479 : considered_clauses,
480 : &considered_relids);
481 : /* Consider each applicable eclass join clause */
482 88034 : considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
483 88034 : consider_index_join_outer_rels(root, rel, index,
484 : rclauseset, jclauseset, eclauseset,
485 : bitindexpaths,
486 : eclauseset->indexclauses[indexcol],
487 : considered_clauses,
488 : &considered_relids);
489 : }
490 59106 : }
491 :
492 : /*
493 : * consider_index_join_outer_rels
494 : * Generate parameterized paths based on clause relids in the clause list.
495 : *
496 : * Workhorse for consider_index_join_clauses; see notes therein for rationale.
497 : *
498 : * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset', and
499 : * 'bitindexpaths' as above
500 : * 'indexjoinclauses' is a list of IndexClauses for join clauses
501 : * 'considered_clauses' is the total number of clauses considered (so far)
502 : * '*considered_relids' is a list of all relids sets already considered
503 : */
504 : static void
505 176068 : consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
506 : IndexOptInfo *index,
507 : IndexClauseSet *rclauseset,
508 : IndexClauseSet *jclauseset,
509 : IndexClauseSet *eclauseset,
510 : List **bitindexpaths,
511 : List *indexjoinclauses,
512 : int considered_clauses,
513 : List **considered_relids)
514 : {
515 : ListCell *lc;
516 :
517 : /* Examine relids of each joinclause in the given list */
518 238088 : foreach(lc, indexjoinclauses)
519 : {
520 62020 : IndexClause *iclause = (IndexClause *) lfirst(lc);
521 62020 : Relids clause_relids = iclause->rinfo->clause_relids;
522 62020 : EquivalenceClass *parent_ec = iclause->rinfo->parent_ec;
523 : int num_considered_relids;
524 :
525 : /* If we already tried its relids set, no need to do so again */
526 62020 : if (bms_equal_any(clause_relids, *considered_relids))
527 1320 : continue;
528 :
529 : /*
530 : * Generate the union of this clause's relids set with each
531 : * previously-tried set. This ensures we try this clause along with
532 : * every interesting subset of previous clauses. However, to avoid
533 : * exponential growth of planning time when there are many clauses,
534 : * limit the number of relid sets accepted to 10 * considered_clauses.
535 : *
536 : * Note: get_join_index_paths appends entries to *considered_relids,
537 : * but we do not need to visit such newly-added entries within this
538 : * loop, so we don't use foreach() here. No real harm would be done
539 : * if we did visit them, since the subset check would reject them; but
540 : * it would waste some cycles.
541 : */
542 60700 : num_considered_relids = list_length(*considered_relids);
543 62334 : for (int pos = 0; pos < num_considered_relids; pos++)
544 : {
545 1634 : Relids oldrelids = (Relids) list_nth(*considered_relids, pos);
546 :
547 : /*
548 : * If either is a subset of the other, no new set is possible.
549 : * This isn't a complete test for redundancy, but it's easy and
550 : * cheap. get_join_index_paths will check more carefully if we
551 : * already generated the same relids set.
552 : */
553 1634 : if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
554 16 : continue;
555 :
556 : /*
557 : * If this clause was derived from an equivalence class, the
558 : * clause list may contain other clauses derived from the same
559 : * eclass. We should not consider that combining this clause with
560 : * one of those clauses generates a usefully different
561 : * parameterization; so skip if any clause derived from the same
562 : * eclass would already have been included when using oldrelids.
563 : */
564 3138 : if (parent_ec &&
565 1520 : eclass_already_used(parent_ec, oldrelids,
566 : indexjoinclauses))
567 1454 : continue;
568 :
569 : /*
570 : * If the number of relid sets considered exceeds our heuristic
571 : * limit, stop considering combinations of clauses. We'll still
572 : * consider the current clause alone, though (below this loop).
573 : */
574 164 : if (list_length(*considered_relids) >= 10 * considered_clauses)
575 0 : break;
576 :
577 : /* OK, try the union set */
578 164 : get_join_index_paths(root, rel, index,
579 : rclauseset, jclauseset, eclauseset,
580 : bitindexpaths,
581 : bms_union(clause_relids, oldrelids),
582 : considered_relids);
583 : }
584 :
585 : /* Also try this set of relids by itself */
586 60700 : get_join_index_paths(root, rel, index,
587 : rclauseset, jclauseset, eclauseset,
588 : bitindexpaths,
589 : clause_relids,
590 : considered_relids);
591 : }
592 176068 : }
593 :
594 : /*
595 : * get_join_index_paths
596 : * Generate index paths using clauses from the specified outer relations.
597 : * In addition to generating paths, relids is added to *considered_relids
598 : * if not already present.
599 : *
600 : * Workhorse for consider_index_join_clauses; see notes therein for rationale.
601 : *
602 : * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset',
603 : * 'bitindexpaths', 'considered_relids' as above
604 : * 'relids' is the current set of relids to consider (the target rel plus
605 : * one or more outer rels)
606 : */
607 : static void
608 60864 : get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
609 : IndexOptInfo *index,
610 : IndexClauseSet *rclauseset,
611 : IndexClauseSet *jclauseset,
612 : IndexClauseSet *eclauseset,
613 : List **bitindexpaths,
614 : Relids relids,
615 : List **considered_relids)
616 : {
617 : IndexClauseSet clauseset;
618 : int indexcol;
619 :
620 : /* If we already considered this relids set, don't repeat the work */
621 60864 : if (bms_equal_any(relids, *considered_relids))
622 0 : return;
623 :
624 : /* Identify indexclauses usable with this relids set */
625 60864 : MemSet(&clauseset, 0, sizeof(clauseset));
626 :
627 152050 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
628 : {
629 : ListCell *lc;
630 :
631 : /* First find applicable simple join clauses */
632 115702 : foreach(lc, jclauseset->indexclauses[indexcol])
633 : {
634 24516 : IndexClause *iclause = (IndexClause *) lfirst(lc);
635 :
636 24516 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
637 24298 : clauseset.indexclauses[indexcol] =
638 24298 : lappend(clauseset.indexclauses[indexcol], iclause);
639 : }
640 :
641 : /*
642 : * Add applicable eclass join clauses. The clauses generated for each
643 : * column are redundant (cf generate_implied_equalities_for_column),
644 : * so we need at most one. This is the only exception to the general
645 : * rule of using all available index clauses.
646 : */
647 93020 : foreach(lc, eclauseset->indexclauses[indexcol])
648 : {
649 39872 : IndexClause *iclause = (IndexClause *) lfirst(lc);
650 :
651 39872 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
652 : {
653 38038 : clauseset.indexclauses[indexcol] =
654 38038 : lappend(clauseset.indexclauses[indexcol], iclause);
655 38038 : break;
656 : }
657 : }
658 :
659 : /* Add restriction clauses */
660 91186 : clauseset.indexclauses[indexcol] =
661 91186 : list_concat(clauseset.indexclauses[indexcol],
662 91186 : rclauseset->indexclauses[indexcol]);
663 :
664 91186 : if (clauseset.indexclauses[indexcol] != NIL)
665 75882 : clauseset.nonempty = true;
666 : }
667 :
668 : /* We should have found something, else caller passed silly relids */
669 : Assert(clauseset.nonempty);
670 :
671 : /* Build index path(s) using the collected set of clauses */
672 60864 : get_index_paths(root, rel, index, &clauseset, bitindexpaths);
673 :
674 : /*
675 : * Remember we considered paths for this set of relids.
676 : */
677 60864 : *considered_relids = lappend(*considered_relids, relids);
678 : }
679 :
680 : /*
681 : * eclass_already_used
682 : * True if any join clause usable with oldrelids was generated from
683 : * the specified equivalence class.
684 : */
685 : static bool
686 1520 : eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
687 : List *indexjoinclauses)
688 : {
689 : ListCell *lc;
690 :
691 1618 : foreach(lc, indexjoinclauses)
692 : {
693 1552 : IndexClause *iclause = (IndexClause *) lfirst(lc);
694 1552 : RestrictInfo *rinfo = iclause->rinfo;
695 :
696 3104 : if (rinfo->parent_ec == parent_ec &&
697 1552 : bms_is_subset(rinfo->clause_relids, oldrelids))
698 1454 : return true;
699 : }
700 66 : return false;
701 : }
702 :
703 : /*
704 : * bms_equal_any
705 : * True if relids is bms_equal to any member of relids_list
706 : *
707 : * Perhaps this should be in bitmapset.c someday.
708 : */
709 : static bool
710 183842 : bms_equal_any(Relids relids, List *relids_list)
711 : {
712 : ListCell *lc;
713 :
714 191588 : foreach(lc, relids_list)
715 : {
716 10408 : if (bms_equal(relids, (Relids) lfirst(lc)))
717 2662 : return true;
718 : }
719 181180 : return false;
720 : }
721 :
722 :
723 : /*
724 : * get_index_paths
725 : * Given an index and a set of index clauses for it, construct IndexPaths.
726 : *
727 : * Plain indexpaths are sent directly to add_path, while potential
728 : * bitmap indexpaths are added to *bitindexpaths for later processing.
729 : *
730 : * This is a fairly simple frontend to build_index_paths(). Its reason for
731 : * existence is mainly to handle ScalarArrayOpExpr quals properly. If the
732 : * index AM supports them natively, we should just include them in simple
733 : * index paths. If not, we should exclude them while building simple index
734 : * paths, and then make a separate attempt to include them in bitmap paths.
735 : * Furthermore, we should consider excluding lower-order ScalarArrayOpExpr
736 : * quals so as to create ordered paths.
737 : */
738 : static void
739 434846 : get_index_paths(PlannerInfo *root, RelOptInfo *rel,
740 : IndexOptInfo *index, IndexClauseSet *clauses,
741 : List **bitindexpaths)
742 : {
743 : List *indexpaths;
744 434846 : bool skip_nonnative_saop = false;
745 434846 : bool skip_lower_saop = false;
746 : ListCell *lc;
747 :
748 : /*
749 : * Build simple index paths using the clauses. Allow ScalarArrayOpExpr
750 : * clauses only if the index AM supports them natively, and skip any such
751 : * clauses for index columns after the first (so that we produce ordered
752 : * paths if possible).
753 : */
754 434846 : indexpaths = build_index_paths(root, rel,
755 : index, clauses,
756 434846 : index->predOK,
757 : ST_ANYSCAN,
758 : &skip_nonnative_saop,
759 : &skip_lower_saop);
760 :
761 : /*
762 : * If we skipped any lower-order ScalarArrayOpExprs on an index with an AM
763 : * that supports them, then try again including those clauses. This will
764 : * produce paths with more selectivity but no ordering.
765 : */
766 434846 : if (skip_lower_saop)
767 : {
768 44 : indexpaths = list_concat(indexpaths,
769 44 : build_index_paths(root, rel,
770 : index, clauses,
771 44 : index->predOK,
772 : ST_ANYSCAN,
773 : &skip_nonnative_saop,
774 : NULL));
775 : }
776 :
777 : /*
778 : * Submit all the ones that can form plain IndexScan plans to add_path. (A
779 : * plain IndexPath can represent either a plain IndexScan or an
780 : * IndexOnlyScan, but for our purposes here that distinction does not
781 : * matter. However, some of the indexes might support only bitmap scans,
782 : * and those we mustn't submit to add_path here.)
783 : *
784 : * Also, pick out the ones that are usable as bitmap scans. For that, we
785 : * must discard indexes that don't support bitmap scans, and we also are
786 : * only interested in paths that have some selectivity; we should discard
787 : * anything that was generated solely for ordering purposes.
788 : */
789 679990 : foreach(lc, indexpaths)
790 : {
791 245144 : IndexPath *ipath = (IndexPath *) lfirst(lc);
792 :
793 245144 : if (index->amhasgettuple)
794 240014 : add_path(rel, (Path *) ipath);
795 :
796 490288 : if (index->amhasgetbitmap &&
797 381604 : (ipath->path.pathkeys == NIL ||
798 136460 : ipath->indexselectivity < 1.0))
799 190002 : *bitindexpaths = lappend(*bitindexpaths, ipath);
800 : }
801 :
802 : /*
803 : * If there were ScalarArrayOpExpr clauses that the index can't handle
804 : * natively, generate bitmap scan paths relying on executor-managed
805 : * ScalarArrayOpExpr.
806 : */
807 434846 : if (skip_nonnative_saop)
808 : {
809 12 : indexpaths = build_index_paths(root, rel,
810 : index, clauses,
811 : false,
812 : ST_BITMAPSCAN,
813 : NULL,
814 : NULL);
815 12 : *bitindexpaths = list_concat(*bitindexpaths, indexpaths);
816 : }
817 434846 : }
818 :
819 : /*
820 : * build_index_paths
821 : * Given an index and a set of index clauses for it, construct zero
822 : * or more IndexPaths. It also constructs zero or more partial IndexPaths.
823 : *
824 : * We return a list of paths because (1) this routine checks some cases
825 : * that should cause us to not generate any IndexPath, and (2) in some
826 : * cases we want to consider both a forward and a backward scan, so as
827 : * to obtain both sort orders. Note that the paths are just returned
828 : * to the caller and not immediately fed to add_path().
829 : *
830 : * At top level, useful_predicate should be exactly the index's predOK flag
831 : * (ie, true if it has a predicate that was proven from the restriction
832 : * clauses). When working on an arm of an OR clause, useful_predicate
833 : * should be true if the predicate required the current OR list to be proven.
834 : * Note that this routine should never be called at all if the index has an
835 : * unprovable predicate.
836 : *
837 : * scantype indicates whether we want to create plain indexscans, bitmap
838 : * indexscans, or both. When it's ST_BITMAPSCAN, we will not consider
839 : * index ordering while deciding if a Path is worth generating.
840 : *
841 : * If skip_nonnative_saop is non-NULL, we ignore ScalarArrayOpExpr clauses
842 : * unless the index AM supports them directly, and we set *skip_nonnative_saop
843 : * to true if we found any such clauses (caller must initialize the variable
844 : * to false). If it's NULL, we do not ignore ScalarArrayOpExpr clauses.
845 : *
846 : * If skip_lower_saop is non-NULL, we ignore ScalarArrayOpExpr clauses for
847 : * non-first index columns, and we set *skip_lower_saop to true if we found
848 : * any such clauses (caller must initialize the variable to false). If it's
849 : * NULL, we do not ignore non-first ScalarArrayOpExpr clauses, but they will
850 : * result in considering the scan's output to be unordered.
851 : *
852 : * 'rel' is the index's heap relation
853 : * 'index' is the index for which we want to generate paths
854 : * 'clauses' is the collection of indexable clauses (IndexClause nodes)
855 : * 'useful_predicate' indicates whether the index has a useful predicate
856 : * 'scantype' indicates whether we need plain or bitmap scan support
857 : * 'skip_nonnative_saop' indicates whether to accept SAOP if index AM doesn't
858 : * 'skip_lower_saop' indicates whether to accept non-first-column SAOP
859 : */
860 : static List *
861 435718 : build_index_paths(PlannerInfo *root, RelOptInfo *rel,
862 : IndexOptInfo *index, IndexClauseSet *clauses,
863 : bool useful_predicate,
864 : ScanTypeControl scantype,
865 : bool *skip_nonnative_saop,
866 : bool *skip_lower_saop)
867 : {
868 435718 : List *result = NIL;
869 : IndexPath *ipath;
870 : List *index_clauses;
871 : Relids outer_relids;
872 : double loop_count;
873 : List *orderbyclauses;
874 : List *orderbyclausecols;
875 : List *index_pathkeys;
876 : List *useful_pathkeys;
877 : bool found_lower_saop_clause;
878 : bool pathkeys_possibly_useful;
879 : bool index_is_ordered;
880 : bool index_only_scan;
881 : int indexcol;
882 :
883 : /*
884 : * Check that index supports the desired scan type(s)
885 : */
886 435718 : switch (scantype)
887 : {
888 : case ST_INDEXSCAN:
889 0 : if (!index->amhasgettuple)
890 0 : return NIL;
891 0 : break;
892 : case ST_BITMAPSCAN:
893 828 : if (!index->amhasgetbitmap)
894 0 : return NIL;
895 828 : break;
896 : case ST_ANYSCAN:
897 : /* either or both are OK */
898 434890 : break;
899 : }
900 :
901 : /*
902 : * 1. Combine the per-column IndexClause lists into an overall list.
903 : *
904 : * In the resulting list, clauses are ordered by index key, so that the
905 : * column numbers form a nondecreasing sequence. (This order is depended
906 : * on by btree and possibly other places.) The list can be empty, if the
907 : * index AM allows that.
908 : *
909 : * found_lower_saop_clause is set true if we accept a ScalarArrayOpExpr
910 : * index clause for a non-first index column. This prevents us from
911 : * assuming that the scan result is ordered. (Actually, the result is
912 : * still ordered if there are equality constraints for all earlier
913 : * columns, but it seems too expensive and non-modular for this code to be
914 : * aware of that refinement.)
915 : *
916 : * We also build a Relids set showing which outer rels are required by the
917 : * selected clauses. Any lateral_relids are included in that, but not
918 : * otherwise accounted for.
919 : */
920 435718 : index_clauses = NIL;
921 435718 : found_lower_saop_clause = false;
922 435718 : outer_relids = bms_copy(rel->lateral_relids);
923 1210764 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
924 : {
925 : ListCell *lc;
926 :
927 998752 : foreach(lc, clauses->indexclauses[indexcol])
928 : {
929 223550 : IndexClause *iclause = (IndexClause *) lfirst(lc);
930 223550 : RestrictInfo *rinfo = iclause->rinfo;
931 :
932 : /* We might need to omit ScalarArrayOpExpr clauses */
933 223550 : if (IsA(rinfo->clause, ScalarArrayOpExpr))
934 : {
935 6814 : if (!index->amsearcharray)
936 : {
937 24 : if (skip_nonnative_saop)
938 : {
939 : /* Ignore because not supported by index */
940 12 : *skip_nonnative_saop = true;
941 12 : continue;
942 : }
943 : /* Caller had better intend this only for bitmap scan */
944 : Assert(scantype == ST_BITMAPSCAN);
945 : }
946 6802 : if (indexcol > 0)
947 : {
948 88 : if (skip_lower_saop)
949 : {
950 : /* Caller doesn't want to lose index ordering */
951 44 : *skip_lower_saop = true;
952 44 : continue;
953 : }
954 44 : found_lower_saop_clause = true;
955 : }
956 : }
957 :
958 : /* OK to include this clause */
959 223494 : index_clauses = lappend(index_clauses, iclause);
960 223494 : outer_relids = bms_add_members(outer_relids,
961 223494 : rinfo->clause_relids);
962 : }
963 :
964 : /*
965 : * If no clauses match the first index column, check for amoptionalkey
966 : * restriction. We can't generate a scan over an index with
967 : * amoptionalkey = false unless there's at least one index clause.
968 : * (When working on columns after the first, this test cannot fail. It
969 : * is always okay for columns after the first to not have any
970 : * clauses.)
971 : */
972 775202 : if (index_clauses == NIL && !index->amoptionalkey)
973 156 : return NIL;
974 : }
975 :
976 : /* We do not want the index's rel itself listed in outer_relids */
977 435562 : outer_relids = bms_del_member(outer_relids, rel->relid);
978 : /* Enforce convention that outer_relids is exactly NULL if empty */
979 435562 : if (bms_is_empty(outer_relids))
980 374606 : outer_relids = NULL;
981 :
982 : /* Compute loop_count for cost estimation purposes */
983 435562 : loop_count = get_loop_count(root, rel->relid, outer_relids);
984 :
985 : /*
986 : * 2. Compute pathkeys describing index's ordering, if any, then see how
987 : * many of them are actually useful for this query. This is not relevant
988 : * if we are only trying to build bitmap indexscans, nor if we have to
989 : * assume the scan is unordered.
990 : */
991 870296 : pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN &&
992 870252 : !found_lower_saop_clause &&
993 434690 : has_useful_pathkeys(root, rel));
994 435562 : index_is_ordered = (index->sortopfamily != NULL);
995 435562 : if (index_is_ordered && pathkeys_possibly_useful)
996 : {
997 263978 : index_pathkeys = build_index_pathkeys(root, index,
998 : ForwardScanDirection);
999 263978 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
1000 : index_pathkeys);
1001 263978 : orderbyclauses = NIL;
1002 263978 : orderbyclausecols = NIL;
1003 : }
1004 171584 : else if (index->amcanorderbyop && pathkeys_possibly_useful)
1005 : {
1006 : /* see if we can generate ordering operators for query_pathkeys */
1007 538 : match_pathkeys_to_index(index, root->query_pathkeys,
1008 : &orderbyclauses,
1009 : &orderbyclausecols);
1010 1076 : if (orderbyclauses)
1011 308 : useful_pathkeys = root->query_pathkeys;
1012 : else
1013 230 : useful_pathkeys = NIL;
1014 : }
1015 : else
1016 : {
1017 171046 : useful_pathkeys = NIL;
1018 171046 : orderbyclauses = NIL;
1019 171046 : orderbyclausecols = NIL;
1020 : }
1021 :
1022 : /*
1023 : * 3. Check if an index-only scan is possible. If we're not building
1024 : * plain indexscans, this isn't relevant since bitmap scans don't support
1025 : * index data retrieval anyway.
1026 : */
1027 870296 : index_only_scan = (scantype != ST_BITMAPSCAN &&
1028 434734 : check_index_only(rel, index));
1029 :
1030 : /*
1031 : * 4. Generate an indexscan path if there are relevant restriction clauses
1032 : * in the current clauses, OR the index ordering is potentially useful for
1033 : * later merging or final output ordering, OR the index has a useful
1034 : * predicate, OR an index-only scan is possible.
1035 : */
1036 435562 : if (index_clauses != NIL || useful_pathkeys != NIL || useful_predicate ||
1037 : index_only_scan)
1038 : {
1039 245704 : ipath = create_index_path(root, index,
1040 : index_clauses,
1041 : orderbyclauses,
1042 : orderbyclausecols,
1043 : useful_pathkeys,
1044 : index_is_ordered ?
1045 : ForwardScanDirection :
1046 : NoMovementScanDirection,
1047 : index_only_scan,
1048 : outer_relids,
1049 : loop_count,
1050 : false);
1051 245704 : result = lappend(result, ipath);
1052 :
1053 : /*
1054 : * If appropriate, consider parallel index scan. We don't allow
1055 : * parallel index scan for bitmap index scans.
1056 : */
1057 483316 : if (index->amcanparallel &&
1058 415198 : rel->consider_parallel && outer_relids == NULL &&
1059 : scantype != ST_BITMAPSCAN)
1060 : {
1061 122558 : ipath = create_index_path(root, index,
1062 : index_clauses,
1063 : orderbyclauses,
1064 : orderbyclausecols,
1065 : useful_pathkeys,
1066 : index_is_ordered ?
1067 : ForwardScanDirection :
1068 : NoMovementScanDirection,
1069 : index_only_scan,
1070 : outer_relids,
1071 : loop_count,
1072 : true);
1073 :
1074 : /*
1075 : * if, after costing the path, we find that it's not worth using
1076 : * parallel workers, just free it.
1077 : */
1078 122558 : if (ipath->path.parallel_workers > 0)
1079 3082 : add_partial_path(rel, (Path *) ipath);
1080 : else
1081 119476 : pfree(ipath);
1082 : }
1083 : }
1084 :
1085 : /*
1086 : * 5. If the index is ordered, a backwards scan might be interesting.
1087 : */
1088 435562 : if (index_is_ordered && pathkeys_possibly_useful)
1089 : {
1090 263978 : index_pathkeys = build_index_pathkeys(root, index,
1091 : BackwardScanDirection);
1092 263978 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
1093 : index_pathkeys);
1094 263978 : if (useful_pathkeys != NIL)
1095 : {
1096 268 : ipath = create_index_path(root, index,
1097 : index_clauses,
1098 : NIL,
1099 : NIL,
1100 : useful_pathkeys,
1101 : BackwardScanDirection,
1102 : index_only_scan,
1103 : outer_relids,
1104 : loop_count,
1105 : false);
1106 268 : result = lappend(result, ipath);
1107 :
1108 : /* If appropriate, consider parallel index scan */
1109 536 : if (index->amcanparallel &&
1110 500 : rel->consider_parallel && outer_relids == NULL &&
1111 : scantype != ST_BITMAPSCAN)
1112 : {
1113 232 : ipath = create_index_path(root, index,
1114 : index_clauses,
1115 : NIL,
1116 : NIL,
1117 : useful_pathkeys,
1118 : BackwardScanDirection,
1119 : index_only_scan,
1120 : outer_relids,
1121 : loop_count,
1122 : true);
1123 :
1124 : /*
1125 : * if, after costing the path, we find that it's not worth
1126 : * using parallel workers, just free it.
1127 : */
1128 232 : if (ipath->path.parallel_workers > 0)
1129 112 : add_partial_path(rel, (Path *) ipath);
1130 : else
1131 120 : pfree(ipath);
1132 : }
1133 : }
1134 : }
1135 :
1136 435562 : return result;
1137 : }
1138 :
1139 : /*
1140 : * build_paths_for_OR
1141 : * Given a list of restriction clauses from one arm of an OR clause,
1142 : * construct all matching IndexPaths for the relation.
1143 : *
1144 : * Here we must scan all indexes of the relation, since a bitmap OR tree
1145 : * can use multiple indexes.
1146 : *
1147 : * The caller actually supplies two lists of restriction clauses: some
1148 : * "current" ones and some "other" ones. Both lists can be used freely
1149 : * to match keys of the index, but an index must use at least one of the
1150 : * "current" clauses to be considered usable. The motivation for this is
1151 : * examples like
1152 : * WHERE (x = 42) AND (... OR (y = 52 AND z = 77) OR ....)
1153 : * While we are considering the y/z subclause of the OR, we can use "x = 42"
1154 : * as one of the available index conditions; but we shouldn't match the
1155 : * subclause to any index on x alone, because such a Path would already have
1156 : * been generated at the upper level. So we could use an index on x,y,z
1157 : * or an index on x,y for the OR subclause, but not an index on just x.
1158 : * When dealing with a partial index, a match of the index predicate to
1159 : * one of the "current" clauses also makes the index usable.
1160 : *
1161 : * 'rel' is the relation for which we want to generate index paths
1162 : * 'clauses' is the current list of clauses (RestrictInfo nodes)
1163 : * 'other_clauses' is the list of additional upper-level clauses
1164 : */
1165 : static List *
1166 14778 : build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
1167 : List *clauses, List *other_clauses)
1168 : {
1169 14778 : List *result = NIL;
1170 14778 : List *all_clauses = NIL; /* not computed till needed */
1171 : ListCell *lc;
1172 :
1173 51810 : foreach(lc, rel->indexlist)
1174 : {
1175 37032 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
1176 : IndexClauseSet clauseset;
1177 : List *indexpaths;
1178 : bool useful_predicate;
1179 :
1180 : /* Ignore index if it doesn't support bitmap scans */
1181 37032 : if (!index->amhasgetbitmap)
1182 36216 : continue;
1183 :
1184 : /*
1185 : * Ignore partial indexes that do not match the query. If a partial
1186 : * index is marked predOK then we know it's OK. Otherwise, we have to
1187 : * test whether the added clauses are sufficient to imply the
1188 : * predicate. If so, we can use the index in the current context.
1189 : *
1190 : * We set useful_predicate to true iff the predicate was proven using
1191 : * the current set of clauses. This is needed to prevent matching a
1192 : * predOK index to an arm of an OR, which would be a legal but
1193 : * pointlessly inefficient plan. (A better plan will be generated by
1194 : * just scanning the predOK index alone, no OR.)
1195 : */
1196 37032 : useful_predicate = false;
1197 37032 : if (index->indpred != NIL)
1198 : {
1199 96 : if (index->predOK)
1200 : {
1201 : /* Usable, but don't set useful_predicate */
1202 : }
1203 : else
1204 : {
1205 : /* Form all_clauses if not done already */
1206 80 : if (all_clauses == NIL)
1207 32 : all_clauses = list_concat_copy(clauses, other_clauses);
1208 :
1209 80 : if (!predicate_implied_by(index->indpred, all_clauses, false))
1210 56 : continue; /* can't use it at all */
1211 :
1212 24 : if (!predicate_implied_by(index->indpred, other_clauses, false))
1213 24 : useful_predicate = true;
1214 : }
1215 : }
1216 :
1217 : /*
1218 : * Identify the restriction clauses that can match the index.
1219 : */
1220 36976 : MemSet(&clauseset, 0, sizeof(clauseset));
1221 36976 : match_clauses_to_index(root, clauses, index, &clauseset);
1222 :
1223 : /*
1224 : * If no matches so far, and the index predicate isn't useful, we
1225 : * don't want it.
1226 : */
1227 36976 : if (!clauseset.nonempty && !useful_predicate)
1228 36160 : continue;
1229 :
1230 : /*
1231 : * Add "other" restriction clauses to the clauseset.
1232 : */
1233 816 : match_clauses_to_index(root, other_clauses, index, &clauseset);
1234 :
1235 : /*
1236 : * Construct paths if possible.
1237 : */
1238 816 : indexpaths = build_index_paths(root, rel,
1239 : index, &clauseset,
1240 : useful_predicate,
1241 : ST_BITMAPSCAN,
1242 : NULL,
1243 : NULL);
1244 816 : result = list_concat(result, indexpaths);
1245 : }
1246 :
1247 14778 : return result;
1248 : }
1249 :
1250 : /*
1251 : * generate_bitmap_or_paths
1252 : * Look through the list of clauses to find OR clauses, and generate
1253 : * a BitmapOrPath for each one we can handle that way. Return a list
1254 : * of the generated BitmapOrPaths.
1255 : *
1256 : * other_clauses is a list of additional clauses that can be assumed true
1257 : * for the purpose of generating indexquals, but are not to be searched for
1258 : * ORs. (See build_paths_for_OR() for motivation.)
1259 : */
1260 : static List *
1261 359156 : generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
1262 : List *clauses, List *other_clauses)
1263 : {
1264 359156 : List *result = NIL;
1265 : List *all_clauses;
1266 : ListCell *lc;
1267 :
1268 : /*
1269 : * We can use both the current and other clauses as context for
1270 : * build_paths_for_OR; no need to remove ORs from the lists.
1271 : */
1272 359156 : all_clauses = list_concat_copy(clauses, other_clauses);
1273 :
1274 548086 : foreach(lc, clauses)
1275 : {
1276 188930 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1277 : List *pathlist;
1278 : Path *bitmapqual;
1279 : ListCell *j;
1280 :
1281 : /* Ignore RestrictInfos that aren't ORs */
1282 188930 : if (!restriction_is_or_clause(rinfo))
1283 174638 : continue;
1284 :
1285 : /*
1286 : * We must be able to match at least one index to each of the arms of
1287 : * the OR, else we can't use it.
1288 : */
1289 14292 : pathlist = NIL;
1290 15096 : foreach(j, ((BoolExpr *) rinfo->orclause)->args)
1291 : {
1292 14778 : Node *orarg = (Node *) lfirst(j);
1293 : List *indlist;
1294 :
1295 : /* OR arguments should be ANDs or sub-RestrictInfos */
1296 14778 : if (is_andclause(orarg))
1297 : {
1298 504 : List *andargs = ((BoolExpr *) orarg)->args;
1299 :
1300 504 : indlist = build_paths_for_OR(root, rel,
1301 : andargs,
1302 : all_clauses);
1303 :
1304 : /* Recurse in case there are sub-ORs */
1305 504 : indlist = list_concat(indlist,
1306 504 : generate_bitmap_or_paths(root, rel,
1307 : andargs,
1308 : all_clauses));
1309 : }
1310 : else
1311 : {
1312 14274 : RestrictInfo *rinfo = castNode(RestrictInfo, orarg);
1313 : List *orargs;
1314 :
1315 : Assert(!restriction_is_or_clause(rinfo));
1316 14274 : orargs = list_make1(rinfo);
1317 :
1318 14274 : indlist = build_paths_for_OR(root, rel,
1319 : orargs,
1320 : all_clauses);
1321 : }
1322 :
1323 : /*
1324 : * If nothing matched this arm, we can't do anything with this OR
1325 : * clause.
1326 : */
1327 14778 : if (indlist == NIL)
1328 : {
1329 13974 : pathlist = NIL;
1330 13974 : break;
1331 : }
1332 :
1333 : /*
1334 : * OK, pick the most promising AND combination, and add it to
1335 : * pathlist.
1336 : */
1337 804 : bitmapqual = choose_bitmap_and(root, rel, indlist);
1338 804 : pathlist = lappend(pathlist, bitmapqual);
1339 : }
1340 :
1341 : /*
1342 : * If we have a match for every arm, then turn them into a
1343 : * BitmapOrPath, and add to result list.
1344 : */
1345 14292 : if (pathlist != NIL)
1346 : {
1347 318 : bitmapqual = (Path *) create_bitmap_or_path(root, rel, pathlist);
1348 318 : result = lappend(result, bitmapqual);
1349 : }
1350 : }
1351 :
1352 359156 : return result;
1353 : }
1354 :
1355 :
1356 : /*
1357 : * choose_bitmap_and
1358 : * Given a nonempty list of bitmap paths, AND them into one path.
1359 : *
1360 : * This is a nontrivial decision since we can legally use any subset of the
1361 : * given path set. We want to choose a good tradeoff between selectivity
1362 : * and cost of computing the bitmap.
1363 : *
1364 : * The result is either a single one of the inputs, or a BitmapAndPath
1365 : * combining multiple inputs.
1366 : */
1367 : static Path *
1368 173924 : choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
1369 : {
1370 173924 : int npaths = list_length(paths);
1371 : PathClauseUsage **pathinfoarray;
1372 : PathClauseUsage *pathinfo;
1373 : List *clauselist;
1374 173924 : List *bestpaths = NIL;
1375 173924 : Cost bestcost = 0;
1376 : int i,
1377 : j;
1378 : ListCell *l;
1379 :
1380 : Assert(npaths > 0); /* else caller error */
1381 173924 : if (npaths == 1)
1382 137238 : return (Path *) linitial(paths); /* easy case */
1383 :
1384 : /*
1385 : * In theory we should consider every nonempty subset of the given paths.
1386 : * In practice that seems like overkill, given the crude nature of the
1387 : * estimates, not to mention the possible effects of higher-level AND and
1388 : * OR clauses. Moreover, it's completely impractical if there are a large
1389 : * number of paths, since the work would grow as O(2^N).
1390 : *
1391 : * As a heuristic, we first check for paths using exactly the same sets of
1392 : * WHERE clauses + index predicate conditions, and reject all but the
1393 : * cheapest-to-scan in any such group. This primarily gets rid of indexes
1394 : * that include the interesting columns but also irrelevant columns. (In
1395 : * situations where the DBA has gone overboard on creating variant
1396 : * indexes, this can make for a very large reduction in the number of
1397 : * paths considered further.)
1398 : *
1399 : * We then sort the surviving paths with the cheapest-to-scan first, and
1400 : * for each path, consider using that path alone as the basis for a bitmap
1401 : * scan. Then we consider bitmap AND scans formed from that path plus
1402 : * each subsequent (higher-cost) path, adding on a subsequent path if it
1403 : * results in a reduction in the estimated total scan cost. This means we
1404 : * consider about O(N^2) rather than O(2^N) path combinations, which is
1405 : * quite tolerable, especially given than N is usually reasonably small
1406 : * because of the prefiltering step. The cheapest of these is returned.
1407 : *
1408 : * We will only consider AND combinations in which no two indexes use the
1409 : * same WHERE clause. This is a bit of a kluge: it's needed because
1410 : * costsize.c and clausesel.c aren't very smart about redundant clauses.
1411 : * They will usually double-count the redundant clauses, producing a
1412 : * too-small selectivity that makes a redundant AND step look like it
1413 : * reduces the total cost. Perhaps someday that code will be smarter and
1414 : * we can remove this limitation. (But note that this also defends
1415 : * against flat-out duplicate input paths, which can happen because
1416 : * match_join_clauses_to_index will find the same OR join clauses that
1417 : * extract_restriction_or_clauses has pulled OR restriction clauses out
1418 : * of.)
1419 : *
1420 : * For the same reason, we reject AND combinations in which an index
1421 : * predicate clause duplicates another clause. Here we find it necessary
1422 : * to be even stricter: we'll reject a partial index if any of its
1423 : * predicate clauses are implied by the set of WHERE clauses and predicate
1424 : * clauses used so far. This covers cases such as a condition "x = 42"
1425 : * used with a plain index, followed by a clauseless scan of a partial
1426 : * index "WHERE x >= 40 AND x < 50". The partial index has been accepted
1427 : * only because "x = 42" was present, and so allowing it would partially
1428 : * double-count selectivity. (We could use predicate_implied_by on
1429 : * regular qual clauses too, to have a more intelligent, but much more
1430 : * expensive, check for redundancy --- but in most cases simple equality
1431 : * seems to suffice.)
1432 : */
1433 :
1434 : /*
1435 : * Extract clause usage info and detect any paths that use exactly the
1436 : * same set of clauses; keep only the cheapest-to-scan of any such groups.
1437 : * The surviving paths are put into an array for qsort'ing.
1438 : */
1439 36686 : pathinfoarray = (PathClauseUsage **)
1440 36686 : palloc(npaths * sizeof(PathClauseUsage *));
1441 36686 : clauselist = NIL;
1442 36686 : npaths = 0;
1443 113496 : foreach(l, paths)
1444 : {
1445 76810 : Path *ipath = (Path *) lfirst(l);
1446 :
1447 76810 : pathinfo = classify_index_clause_usage(ipath, &clauselist);
1448 :
1449 : /* If it's unclassifiable, treat it as distinct from all others */
1450 76810 : if (pathinfo->unclassifiable)
1451 : {
1452 0 : pathinfoarray[npaths++] = pathinfo;
1453 0 : continue;
1454 : }
1455 :
1456 112360 : for (i = 0; i < npaths; i++)
1457 : {
1458 87060 : if (!pathinfoarray[i]->unclassifiable &&
1459 43530 : bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
1460 7980 : break;
1461 : }
1462 76810 : if (i < npaths)
1463 : {
1464 : /* duplicate clauseids, keep the cheaper one */
1465 : Cost ncost;
1466 : Cost ocost;
1467 : Selectivity nselec;
1468 : Selectivity oselec;
1469 :
1470 7980 : cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
1471 7980 : cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
1472 7980 : if (ncost < ocost)
1473 594 : pathinfoarray[i] = pathinfo;
1474 : }
1475 : else
1476 : {
1477 : /* not duplicate clauseids, add to array */
1478 68830 : pathinfoarray[npaths++] = pathinfo;
1479 : }
1480 : }
1481 :
1482 : /* If only one surviving path, we're done */
1483 36686 : if (npaths == 1)
1484 6302 : return pathinfoarray[0]->path;
1485 :
1486 : /* Sort the surviving paths by index access cost */
1487 30384 : qsort(pathinfoarray, npaths, sizeof(PathClauseUsage *),
1488 : path_usage_comparator);
1489 :
1490 : /*
1491 : * For each surviving index, consider it as an "AND group leader", and see
1492 : * whether adding on any of the later indexes results in an AND path with
1493 : * cheaper total cost than before. Then take the cheapest AND group.
1494 : *
1495 : * Note: paths that are either clauseless or unclassifiable will have
1496 : * empty clauseids, so that they will not be rejected by the clauseids
1497 : * filter here, nor will they cause later paths to be rejected by it.
1498 : */
1499 92912 : for (i = 0; i < npaths; i++)
1500 : {
1501 : Cost costsofar;
1502 : List *qualsofar;
1503 : Bitmapset *clauseidsofar;
1504 :
1505 62528 : pathinfo = pathinfoarray[i];
1506 62528 : paths = list_make1(pathinfo->path);
1507 62528 : costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
1508 62528 : qualsofar = list_concat_copy(pathinfo->quals, pathinfo->preds);
1509 62528 : clauseidsofar = bms_copy(pathinfo->clauseids);
1510 :
1511 96688 : for (j = i + 1; j < npaths; j++)
1512 : {
1513 : Cost newcost;
1514 :
1515 34160 : pathinfo = pathinfoarray[j];
1516 : /* Check for redundancy */
1517 34160 : if (bms_overlap(pathinfo->clauseids, clauseidsofar))
1518 22234 : continue; /* consider it redundant */
1519 11926 : if (pathinfo->preds)
1520 : {
1521 8 : bool redundant = false;
1522 :
1523 : /* we check each predicate clause separately */
1524 8 : foreach(l, pathinfo->preds)
1525 : {
1526 8 : Node *np = (Node *) lfirst(l);
1527 :
1528 8 : if (predicate_implied_by(list_make1(np), qualsofar, false))
1529 : {
1530 8 : redundant = true;
1531 8 : break; /* out of inner foreach loop */
1532 : }
1533 : }
1534 8 : if (redundant)
1535 8 : continue;
1536 : }
1537 : /* tentatively add new path to paths, so we can estimate cost */
1538 11918 : paths = lappend(paths, pathinfo->path);
1539 11918 : newcost = bitmap_and_cost_est(root, rel, paths);
1540 11918 : if (newcost < costsofar)
1541 : {
1542 : /* keep new path in paths, update subsidiary variables */
1543 328 : costsofar = newcost;
1544 328 : qualsofar = list_concat(qualsofar, pathinfo->quals);
1545 328 : qualsofar = list_concat(qualsofar, pathinfo->preds);
1546 328 : clauseidsofar = bms_add_members(clauseidsofar,
1547 328 : pathinfo->clauseids);
1548 : }
1549 : else
1550 : {
1551 : /* reject new path, remove it from paths list */
1552 11590 : paths = list_truncate(paths, list_length(paths) - 1);
1553 : }
1554 : }
1555 :
1556 : /* Keep the cheapest AND-group (or singleton) */
1557 62528 : if (i == 0 || costsofar < bestcost)
1558 : {
1559 31410 : bestpaths = paths;
1560 31410 : bestcost = costsofar;
1561 : }
1562 :
1563 : /* some easy cleanup (we don't try real hard though) */
1564 62528 : list_free(qualsofar);
1565 : }
1566 :
1567 30384 : if (list_length(bestpaths) == 1)
1568 30336 : return (Path *) linitial(bestpaths); /* no need for AND */
1569 48 : return (Path *) create_bitmap_and_path(root, rel, bestpaths);
1570 : }
1571 :
1572 : /* qsort comparator to sort in increasing index access cost order */
1573 : static int
1574 33154 : path_usage_comparator(const void *a, const void *b)
1575 : {
1576 33154 : PathClauseUsage *pa = *(PathClauseUsage *const *) a;
1577 33154 : PathClauseUsage *pb = *(PathClauseUsage *const *) b;
1578 : Cost acost;
1579 : Cost bcost;
1580 : Selectivity aselec;
1581 : Selectivity bselec;
1582 :
1583 33154 : cost_bitmap_tree_node(pa->path, &acost, &aselec);
1584 33154 : cost_bitmap_tree_node(pb->path, &bcost, &bselec);
1585 :
1586 : /*
1587 : * If costs are the same, sort by selectivity.
1588 : */
1589 33154 : if (acost < bcost)
1590 23332 : return -1;
1591 9822 : if (acost > bcost)
1592 6806 : return 1;
1593 :
1594 3016 : if (aselec < bselec)
1595 2264 : return -1;
1596 752 : if (aselec > bselec)
1597 226 : return 1;
1598 :
1599 526 : return 0;
1600 : }
1601 :
1602 : /*
1603 : * Estimate the cost of actually executing a bitmap scan with a single
1604 : * index path (no BitmapAnd, at least not at this level; but it could be
1605 : * a BitmapOr).
1606 : */
1607 : static Cost
1608 62528 : bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
1609 : {
1610 : BitmapHeapPath bpath;
1611 : Relids required_outer;
1612 :
1613 : /* Identify required outer rels, in case it's a parameterized scan */
1614 62528 : required_outer = get_bitmap_tree_required_outer(ipath);
1615 :
1616 : /* Set up a dummy BitmapHeapPath */
1617 62528 : bpath.path.type = T_BitmapHeapPath;
1618 62528 : bpath.path.pathtype = T_BitmapHeapScan;
1619 62528 : bpath.path.parent = rel;
1620 62528 : bpath.path.pathtarget = rel->reltarget;
1621 62528 : bpath.path.param_info = get_baserel_parampathinfo(root, rel,
1622 : required_outer);
1623 62528 : bpath.path.pathkeys = NIL;
1624 62528 : bpath.bitmapqual = ipath;
1625 :
1626 : /*
1627 : * Check the cost of temporary path without considering parallelism.
1628 : * Parallel bitmap heap path will be considered at later stage.
1629 : */
1630 62528 : bpath.path.parallel_workers = 0;
1631 62528 : cost_bitmap_heap_scan(&bpath.path, root, rel,
1632 : bpath.path.param_info,
1633 : ipath,
1634 : get_loop_count(root, rel->relid, required_outer));
1635 :
1636 62528 : return bpath.path.total_cost;
1637 : }
1638 :
1639 : /*
1640 : * Estimate the cost of actually executing a BitmapAnd scan with the given
1641 : * inputs.
1642 : */
1643 : static Cost
1644 11918 : bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
1645 : {
1646 : BitmapAndPath apath;
1647 : BitmapHeapPath bpath;
1648 : Relids required_outer;
1649 :
1650 : /* Set up a dummy BitmapAndPath */
1651 11918 : apath.path.type = T_BitmapAndPath;
1652 11918 : apath.path.pathtype = T_BitmapAnd;
1653 11918 : apath.path.parent = rel;
1654 11918 : apath.path.pathtarget = rel->reltarget;
1655 11918 : apath.path.param_info = NULL; /* not used in bitmap trees */
1656 11918 : apath.path.pathkeys = NIL;
1657 11918 : apath.bitmapquals = paths;
1658 11918 : cost_bitmap_and_node(&apath, root);
1659 :
1660 : /* Identify required outer rels, in case it's a parameterized scan */
1661 11918 : required_outer = get_bitmap_tree_required_outer((Path *) &apath);
1662 :
1663 : /* Set up a dummy BitmapHeapPath */
1664 11918 : bpath.path.type = T_BitmapHeapPath;
1665 11918 : bpath.path.pathtype = T_BitmapHeapScan;
1666 11918 : bpath.path.parent = rel;
1667 11918 : bpath.path.pathtarget = rel->reltarget;
1668 11918 : bpath.path.param_info = get_baserel_parampathinfo(root, rel,
1669 : required_outer);
1670 11918 : bpath.path.pathkeys = NIL;
1671 11918 : bpath.bitmapqual = (Path *) &apath;
1672 :
1673 : /*
1674 : * Check the cost of temporary path without considering parallelism.
1675 : * Parallel bitmap heap path will be considered at later stage.
1676 : */
1677 11918 : bpath.path.parallel_workers = 0;
1678 :
1679 : /* Now we can do cost_bitmap_heap_scan */
1680 11918 : cost_bitmap_heap_scan(&bpath.path, root, rel,
1681 : bpath.path.param_info,
1682 : (Path *) &apath,
1683 : get_loop_count(root, rel->relid, required_outer));
1684 :
1685 11918 : return bpath.path.total_cost;
1686 : }
1687 :
1688 :
1689 : /*
1690 : * classify_index_clause_usage
1691 : * Construct a PathClauseUsage struct describing the WHERE clauses and
1692 : * index predicate clauses used by the given indexscan path.
1693 : * We consider two clauses the same if they are equal().
1694 : *
1695 : * At some point we might want to migrate this info into the Path data
1696 : * structure proper, but for the moment it's only needed within
1697 : * choose_bitmap_and().
1698 : *
1699 : * *clauselist is used and expanded as needed to identify all the distinct
1700 : * clauses seen across successive calls. Caller must initialize it to NIL
1701 : * before first call of a set.
1702 : */
1703 : static PathClauseUsage *
1704 76810 : classify_index_clause_usage(Path *path, List **clauselist)
1705 : {
1706 : PathClauseUsage *result;
1707 : Bitmapset *clauseids;
1708 : ListCell *lc;
1709 :
1710 76810 : result = (PathClauseUsage *) palloc(sizeof(PathClauseUsage));
1711 76810 : result->path = path;
1712 :
1713 : /* Recursively find the quals and preds used by the path */
1714 76810 : result->quals = NIL;
1715 76810 : result->preds = NIL;
1716 76810 : find_indexpath_quals(path, &result->quals, &result->preds);
1717 :
1718 : /*
1719 : * Some machine-generated queries have outlandish numbers of qual clauses.
1720 : * To avoid getting into O(N^2) behavior even in this preliminary
1721 : * classification step, we want to limit the number of entries we can
1722 : * accumulate in *clauselist. Treat any path with more than 100 quals +
1723 : * preds as unclassifiable, which will cause calling code to consider it
1724 : * distinct from all other paths.
1725 : */
1726 76810 : if (list_length(result->quals) + list_length(result->preds) > 100)
1727 : {
1728 0 : result->clauseids = NULL;
1729 0 : result->unclassifiable = true;
1730 0 : return result;
1731 : }
1732 :
1733 : /* Build up a bitmapset representing the quals and preds */
1734 76810 : clauseids = NULL;
1735 182596 : foreach(lc, result->quals)
1736 : {
1737 105786 : Node *node = (Node *) lfirst(lc);
1738 :
1739 105786 : clauseids = bms_add_member(clauseids,
1740 : find_list_position(node, clauselist));
1741 : }
1742 76922 : foreach(lc, result->preds)
1743 : {
1744 112 : Node *node = (Node *) lfirst(lc);
1745 :
1746 112 : clauseids = bms_add_member(clauseids,
1747 : find_list_position(node, clauselist));
1748 : }
1749 76810 : result->clauseids = clauseids;
1750 76810 : result->unclassifiable = false;
1751 :
1752 76810 : return result;
1753 : }
1754 :
1755 :
1756 : /*
1757 : * get_bitmap_tree_required_outer
1758 : * Find the required outer rels for a bitmap tree (index/and/or)
1759 : *
1760 : * We don't associate any particular parameterization with a BitmapAnd or
1761 : * BitmapOr node; however, the IndexPaths have parameterization info, in
1762 : * their capacity as standalone access paths. The parameterization required
1763 : * for the bitmap heap scan node is the union of rels referenced in the
1764 : * child IndexPaths.
1765 : */
1766 : static Relids
1767 219720 : get_bitmap_tree_required_outer(Path *bitmapqual)
1768 : {
1769 219720 : Relids result = NULL;
1770 : ListCell *lc;
1771 :
1772 219720 : if (IsA(bitmapqual, IndexPath))
1773 : {
1774 207384 : return bms_copy(PATH_REQ_OUTER(bitmapqual));
1775 : }
1776 12336 : else if (IsA(bitmapqual, BitmapAndPath))
1777 : {
1778 35766 : foreach(lc, ((BitmapAndPath *) bitmapqual)->bitmapquals)
1779 : {
1780 23844 : result = bms_join(result,
1781 23844 : get_bitmap_tree_required_outer((Path *) lfirst(lc)));
1782 : }
1783 : }
1784 414 : else if (IsA(bitmapqual, BitmapOrPath))
1785 : {
1786 1270 : foreach(lc, ((BitmapOrPath *) bitmapqual)->bitmapquals)
1787 : {
1788 856 : result = bms_join(result,
1789 856 : get_bitmap_tree_required_outer((Path *) lfirst(lc)));
1790 : }
1791 : }
1792 : else
1793 0 : elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
1794 :
1795 12336 : return result;
1796 : }
1797 :
1798 :
1799 : /*
1800 : * find_indexpath_quals
1801 : *
1802 : * Given the Path structure for a plain or bitmap indexscan, extract lists
1803 : * of all the index clauses and index predicate conditions used in the Path.
1804 : * These are appended to the initial contents of *quals and *preds (hence
1805 : * caller should initialize those to NIL).
1806 : *
1807 : * Note we are not trying to produce an accurate representation of the AND/OR
1808 : * semantics of the Path, but just find out all the base conditions used.
1809 : *
1810 : * The result lists contain pointers to the expressions used in the Path,
1811 : * but all the list cells are freshly built, so it's safe to destructively
1812 : * modify the lists (eg, by concat'ing with other lists).
1813 : */
1814 : static void
1815 77666 : find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
1816 : {
1817 77666 : if (IsA(bitmapqual, BitmapAndPath))
1818 : {
1819 0 : BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
1820 : ListCell *l;
1821 :
1822 0 : foreach(l, apath->bitmapquals)
1823 : {
1824 0 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
1825 : }
1826 : }
1827 77666 : else if (IsA(bitmapqual, BitmapOrPath))
1828 : {
1829 414 : BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
1830 : ListCell *l;
1831 :
1832 1270 : foreach(l, opath->bitmapquals)
1833 : {
1834 856 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
1835 : }
1836 : }
1837 77252 : else if (IsA(bitmapqual, IndexPath))
1838 : {
1839 77252 : IndexPath *ipath = (IndexPath *) bitmapqual;
1840 : ListCell *l;
1841 :
1842 183038 : foreach(l, ipath->indexclauses)
1843 : {
1844 105786 : IndexClause *iclause = (IndexClause *) lfirst(l);
1845 :
1846 105786 : *quals = lappend(*quals, iclause->rinfo->clause);
1847 : }
1848 77252 : *preds = list_concat(*preds, ipath->indexinfo->indpred);
1849 : }
1850 : else
1851 0 : elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
1852 77666 : }
1853 :
1854 :
1855 : /*
1856 : * find_list_position
1857 : * Return the given node's position (counting from 0) in the given
1858 : * list of nodes. If it's not equal() to any existing list member,
1859 : * add it at the end, and return that position.
1860 : */
1861 : static int
1862 105898 : find_list_position(Node *node, List **nodelist)
1863 : {
1864 : int i;
1865 : ListCell *lc;
1866 :
1867 105898 : i = 0;
1868 161874 : foreach(lc, *nodelist)
1869 : {
1870 88588 : Node *oldnode = (Node *) lfirst(lc);
1871 :
1872 88588 : if (equal(node, oldnode))
1873 32612 : return i;
1874 55976 : i++;
1875 : }
1876 :
1877 73286 : *nodelist = lappend(*nodelist, node);
1878 :
1879 73286 : return i;
1880 : }
1881 :
1882 :
1883 : /*
1884 : * check_index_only
1885 : * Determine whether an index-only scan is possible for this index.
1886 : */
1887 : static bool
1888 434734 : check_index_only(RelOptInfo *rel, IndexOptInfo *index)
1889 : {
1890 : bool result;
1891 434734 : Bitmapset *attrs_used = NULL;
1892 434734 : Bitmapset *index_canreturn_attrs = NULL;
1893 434734 : Bitmapset *index_cannotreturn_attrs = NULL;
1894 : ListCell *lc;
1895 : int i;
1896 :
1897 : /* Index-only scans must be enabled */
1898 434734 : if (!enable_indexonlyscan)
1899 1776 : return false;
1900 :
1901 : /*
1902 : * Check that all needed attributes of the relation are available from the
1903 : * index.
1904 : */
1905 :
1906 : /*
1907 : * First, identify all the attributes needed for joins or final output.
1908 : * Note: we must look at rel's targetlist, not the attr_needed data,
1909 : * because attr_needed isn't computed for inheritance child rels.
1910 : */
1911 432958 : pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
1912 :
1913 : /*
1914 : * Add all the attributes used by restriction clauses; but consider only
1915 : * those clauses not implied by the index predicate, since ones that are
1916 : * so implied don't need to be checked explicitly in the plan.
1917 : *
1918 : * Note: attributes used only in index quals would not be needed at
1919 : * runtime either, if we are certain that the index is not lossy. However
1920 : * it'd be complicated to account for that accurately, and it doesn't
1921 : * matter in most cases, since we'd conclude that such attributes are
1922 : * available from the index anyway.
1923 : */
1924 847486 : foreach(lc, index->indrestrictinfo)
1925 : {
1926 414528 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
1927 :
1928 414528 : pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
1929 : }
1930 :
1931 : /*
1932 : * Construct a bitmapset of columns that the index can return back in an
1933 : * index-only scan. If there are multiple index columns containing the
1934 : * same attribute, all of them must be capable of returning the value,
1935 : * since we might recheck operators on any of them. (Potentially we could
1936 : * be smarter about that, but it's such a weird situation that it doesn't
1937 : * seem worth spending a lot of sweat on.)
1938 : */
1939 1205180 : for (i = 0; i < index->ncolumns; i++)
1940 : {
1941 772222 : int attno = index->indexkeys[i];
1942 :
1943 : /*
1944 : * For the moment, we just ignore index expressions. It might be nice
1945 : * to do something with them, later.
1946 : */
1947 772222 : if (attno == 0)
1948 1694 : continue;
1949 :
1950 770528 : if (index->canreturn[i])
1951 649040 : index_canreturn_attrs =
1952 649040 : bms_add_member(index_canreturn_attrs,
1953 : attno - FirstLowInvalidHeapAttributeNumber);
1954 : else
1955 121488 : index_cannotreturn_attrs =
1956 121488 : bms_add_member(index_cannotreturn_attrs,
1957 : attno - FirstLowInvalidHeapAttributeNumber);
1958 : }
1959 :
1960 432958 : index_canreturn_attrs = bms_del_members(index_canreturn_attrs,
1961 : index_cannotreturn_attrs);
1962 :
1963 : /* Do we have all the necessary attributes? */
1964 432958 : result = bms_is_subset(attrs_used, index_canreturn_attrs);
1965 :
1966 432958 : bms_free(attrs_used);
1967 432958 : bms_free(index_canreturn_attrs);
1968 432958 : bms_free(index_cannotreturn_attrs);
1969 :
1970 432958 : return result;
1971 : }
1972 :
1973 : /*
1974 : * get_loop_count
1975 : * Choose the loop count estimate to use for costing a parameterized path
1976 : * with the given set of outer relids.
1977 : *
1978 : * Since we produce parameterized paths before we've begun to generate join
1979 : * relations, it's impossible to predict exactly how many times a parameterized
1980 : * path will be iterated; we don't know the size of the relation that will be
1981 : * on the outside of the nestloop. However, we should try to account for
1982 : * multiple iterations somehow in costing the path. The heuristic embodied
1983 : * here is to use the rowcount of the smallest other base relation needed in
1984 : * the join clauses used by the path. (We could alternatively consider the
1985 : * largest one, but that seems too optimistic.) This is of course the right
1986 : * answer for single-other-relation cases, and it seems like a reasonable
1987 : * zero-order approximation for multiway-join cases.
1988 : *
1989 : * In addition, we check to see if the other side of each join clause is on
1990 : * the inside of some semijoin that the current relation is on the outside of.
1991 : * If so, the only way that a parameterized path could be used is if the
1992 : * semijoin RHS has been unique-ified, so we should use the number of unique
1993 : * RHS rows rather than using the relation's raw rowcount.
1994 : *
1995 : * Note: for this to work, allpaths.c must establish all baserel size
1996 : * estimates before it begins to compute paths, or at least before it
1997 : * calls create_index_paths().
1998 : */
1999 : static double
2000 569624 : get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
2001 : {
2002 : double result;
2003 : int outer_relid;
2004 :
2005 : /* For a non-parameterized path, just return 1.0 quickly */
2006 569624 : if (outer_relids == NULL)
2007 423062 : return 1.0;
2008 :
2009 146562 : result = 0.0;
2010 146562 : outer_relid = -1;
2011 440428 : while ((outer_relid = bms_next_member(outer_relids, outer_relid)) >= 0)
2012 : {
2013 : RelOptInfo *outer_rel;
2014 : double rowcount;
2015 :
2016 : /* Paranoia: ignore bogus relid indexes */
2017 147304 : if (outer_relid >= root->simple_rel_array_size)
2018 0 : continue;
2019 147304 : outer_rel = root->simple_rel_array[outer_relid];
2020 147304 : if (outer_rel == NULL)
2021 0 : continue;
2022 : Assert(outer_rel->relid == outer_relid); /* sanity check on array */
2023 :
2024 : /* Other relation could be proven empty, if so ignore */
2025 147304 : if (IS_DUMMY_REL(outer_rel))
2026 16 : continue;
2027 :
2028 : /* Otherwise, rel's rows estimate should be valid by now */
2029 : Assert(outer_rel->rows > 0);
2030 :
2031 : /* Check to see if rel is on the inside of any semijoins */
2032 147288 : rowcount = adjust_rowcount_for_semijoins(root,
2033 : cur_relid,
2034 : outer_relid,
2035 : outer_rel->rows);
2036 :
2037 : /* Remember smallest row count estimate among the outer rels */
2038 147288 : if (result == 0.0 || result > rowcount)
2039 146830 : result = rowcount;
2040 : }
2041 : /* Return 1.0 if we found no valid relations (shouldn't happen) */
2042 146562 : return (result > 0.0) ? result : 1.0;
2043 : }
2044 :
2045 : /*
2046 : * Check to see if outer_relid is on the inside of any semijoin that cur_relid
2047 : * is on the outside of. If so, replace rowcount with the estimated number of
2048 : * unique rows from the semijoin RHS (assuming that's smaller, which it might
2049 : * not be). The estimate is crude but it's the best we can do at this stage
2050 : * of the proceedings.
2051 : */
2052 : static double
2053 147288 : adjust_rowcount_for_semijoins(PlannerInfo *root,
2054 : Index cur_relid,
2055 : Index outer_relid,
2056 : double rowcount)
2057 : {
2058 : ListCell *lc;
2059 :
2060 263266 : foreach(lc, root->join_info_list)
2061 : {
2062 115978 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
2063 :
2064 118090 : if (sjinfo->jointype == JOIN_SEMI &&
2065 2416 : bms_is_member(cur_relid, sjinfo->syn_lefthand) &&
2066 304 : bms_is_member(outer_relid, sjinfo->syn_righthand))
2067 : {
2068 : /* Estimate number of unique-ified rows */
2069 : double nraw;
2070 : double nunique;
2071 :
2072 248 : nraw = approximate_joinrel_size(root, sjinfo->syn_righthand);
2073 248 : nunique = estimate_num_groups(root,
2074 : sjinfo->semi_rhs_exprs,
2075 : nraw,
2076 : NULL);
2077 248 : if (rowcount > nunique)
2078 116 : rowcount = nunique;
2079 : }
2080 : }
2081 147288 : return rowcount;
2082 : }
2083 :
2084 : /*
2085 : * Make an approximate estimate of the size of a joinrel.
2086 : *
2087 : * We don't have enough info at this point to get a good estimate, so we
2088 : * just multiply the base relation sizes together. Fortunately, this is
2089 : * the right answer anyway for the most common case with a single relation
2090 : * on the RHS of a semijoin. Also, estimate_num_groups() has only a weak
2091 : * dependency on its input_rows argument (it basically uses it as a clamp).
2092 : * So we might be able to get a fairly decent end result even with a severe
2093 : * overestimate of the RHS's raw size.
2094 : */
2095 : static double
2096 248 : approximate_joinrel_size(PlannerInfo *root, Relids relids)
2097 : {
2098 248 : double rowcount = 1.0;
2099 : int relid;
2100 :
2101 248 : relid = -1;
2102 792 : while ((relid = bms_next_member(relids, relid)) >= 0)
2103 : {
2104 : RelOptInfo *rel;
2105 :
2106 : /* Paranoia: ignore bogus relid indexes */
2107 296 : if (relid >= root->simple_rel_array_size)
2108 0 : continue;
2109 296 : rel = root->simple_rel_array[relid];
2110 296 : if (rel == NULL)
2111 0 : continue;
2112 : Assert(rel->relid == relid); /* sanity check on array */
2113 :
2114 : /* Relation could be proven empty, if so ignore */
2115 296 : if (IS_DUMMY_REL(rel))
2116 0 : continue;
2117 :
2118 : /* Otherwise, rel's rows estimate should be valid by now */
2119 : Assert(rel->rows > 0);
2120 :
2121 : /* Accumulate product */
2122 296 : rowcount *= rel->rows;
2123 : }
2124 248 : return rowcount;
2125 : }
2126 :
2127 :
2128 : /****************************************************************************
2129 : * ---- ROUTINES TO CHECK QUERY CLAUSES ----
2130 : ****************************************************************************/
2131 :
2132 : /*
2133 : * match_restriction_clauses_to_index
2134 : * Identify restriction clauses for the rel that match the index.
2135 : * Matching clauses are added to *clauseset.
2136 : */
2137 : static void
2138 373982 : match_restriction_clauses_to_index(PlannerInfo *root,
2139 : IndexOptInfo *index,
2140 : IndexClauseSet *clauseset)
2141 : {
2142 : /* We can ignore clauses that are implied by the index predicate */
2143 373982 : match_clauses_to_index(root, index->indrestrictinfo, index, clauseset);
2144 373982 : }
2145 :
2146 : /*
2147 : * match_join_clauses_to_index
2148 : * Identify join clauses for the rel that match the index.
2149 : * Matching clauses are added to *clauseset.
2150 : * Also, add any potentially usable join OR clauses to *joinorclauses.
2151 : */
2152 : static void
2153 373982 : match_join_clauses_to_index(PlannerInfo *root,
2154 : RelOptInfo *rel, IndexOptInfo *index,
2155 : IndexClauseSet *clauseset,
2156 : List **joinorclauses)
2157 : {
2158 : ListCell *lc;
2159 :
2160 : /* Scan the rel's join clauses */
2161 524154 : foreach(lc, rel->joininfo)
2162 : {
2163 150172 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2164 :
2165 : /* Check if clause can be moved to this rel */
2166 150172 : if (!join_clause_is_movable_to(rinfo, rel))
2167 74032 : continue;
2168 :
2169 : /* Potentially usable, so see if it matches the index or is an OR */
2170 76140 : if (restriction_is_or_clause(rinfo))
2171 13286 : *joinorclauses = lappend(*joinorclauses, rinfo);
2172 : else
2173 62854 : match_clause_to_index(root, rinfo, index, clauseset);
2174 : }
2175 373982 : }
2176 :
2177 : /*
2178 : * match_eclass_clauses_to_index
2179 : * Identify EquivalenceClass join clauses for the rel that match the index.
2180 : * Matching clauses are added to *clauseset.
2181 : */
2182 : static void
2183 373982 : match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index,
2184 : IndexClauseSet *clauseset)
2185 : {
2186 : int indexcol;
2187 :
2188 : /* No work if rel is not in any such ECs */
2189 373982 : if (!index->rel->has_eclass_joins)
2190 281432 : return;
2191 :
2192 236234 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2193 : {
2194 : ec_member_matches_arg arg;
2195 : List *clauses;
2196 :
2197 : /* Generate clauses, skipping any that join to lateral_referencers */
2198 143684 : arg.index = index;
2199 143684 : arg.indexcol = indexcol;
2200 143684 : clauses = generate_implied_equalities_for_column(root,
2201 : index->rel,
2202 : ec_member_matches_indexcol,
2203 : (void *) &arg,
2204 143684 : index->rel->lateral_referencers);
2205 :
2206 : /*
2207 : * We have to check whether the results actually do match the index,
2208 : * since for non-btree indexes the EC's equality operators might not
2209 : * be in the index opclass (cf ec_member_matches_indexcol).
2210 : */
2211 143684 : match_clauses_to_index(root, clauses, index, clauseset);
2212 : }
2213 : }
2214 :
2215 : /*
2216 : * match_clauses_to_index
2217 : * Perform match_clause_to_index() for each clause in a list.
2218 : * Matching clauses are added to *clauseset.
2219 : */
2220 : static void
2221 555458 : match_clauses_to_index(PlannerInfo *root,
2222 : List *clauses,
2223 : IndexOptInfo *index,
2224 : IndexClauseSet *clauseset)
2225 : {
2226 : ListCell *lc;
2227 :
2228 1011388 : foreach(lc, clauses)
2229 : {
2230 455930 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
2231 :
2232 455930 : match_clause_to_index(root, rinfo, index, clauseset);
2233 : }
2234 555458 : }
2235 :
2236 : /*
2237 : * match_clause_to_index
2238 : * Test whether a qual clause can be used with an index.
2239 : *
2240 : * If the clause is usable, add an IndexClause entry for it to the appropriate
2241 : * list in *clauseset. (*clauseset must be initialized to zeroes before first
2242 : * call.)
2243 : *
2244 : * Note: in some circumstances we may find the same RestrictInfos coming from
2245 : * multiple places. Defend against redundant outputs by refusing to add a
2246 : * clause twice (pointer equality should be a good enough check for this).
2247 : *
2248 : * Note: it's possible that a badly-defined index could have multiple matching
2249 : * columns. We always select the first match if so; this avoids scenarios
2250 : * wherein we get an inflated idea of the index's selectivity by using the
2251 : * same clause multiple times with different index columns.
2252 : */
2253 : static void
2254 518784 : match_clause_to_index(PlannerInfo *root,
2255 : RestrictInfo *rinfo,
2256 : IndexOptInfo *index,
2257 : IndexClauseSet *clauseset)
2258 : {
2259 : int indexcol;
2260 :
2261 : /*
2262 : * Never match pseudoconstants to indexes. (Normally a match could not
2263 : * happen anyway, since a pseudoconstant clause couldn't contain a Var,
2264 : * but what if someone builds an expression index on a constant? It's not
2265 : * totally unreasonable to do so with a partial index, either.)
2266 : */
2267 518784 : if (rinfo->pseudoconstant)
2268 4736 : return;
2269 :
2270 : /*
2271 : * If clause can't be used as an indexqual because it must wait till after
2272 : * some lower-security-level restriction clause, reject it.
2273 : */
2274 514048 : if (!restriction_is_securely_promotable(rinfo, index->rel))
2275 524 : return;
2276 :
2277 : /* OK, check each index key column for a match */
2278 1096166 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2279 : {
2280 : IndexClause *iclause;
2281 : ListCell *lc;
2282 :
2283 : /* Ignore duplicates */
2284 821058 : foreach(lc, clauseset->indexclauses[indexcol])
2285 : {
2286 31390 : IndexClause *iclause = (IndexClause *) lfirst(lc);
2287 :
2288 31390 : if (iclause->rinfo == rinfo)
2289 0 : return;
2290 : }
2291 :
2292 : /* OK, try to match the clause to the index column */
2293 789668 : iclause = match_clause_to_indexcol(root,
2294 : rinfo,
2295 : indexcol,
2296 : index);
2297 789668 : if (iclause)
2298 : {
2299 : /* Success, so record it */
2300 207026 : clauseset->indexclauses[indexcol] =
2301 207026 : lappend(clauseset->indexclauses[indexcol], iclause);
2302 207026 : clauseset->nonempty = true;
2303 207026 : return;
2304 : }
2305 : }
2306 : }
2307 :
2308 : /*
2309 : * match_clause_to_indexcol()
2310 : * Determine whether a restriction clause matches a column of an index,
2311 : * and if so, build an IndexClause node describing the details.
2312 : *
2313 : * To match an index normally, an operator clause:
2314 : *
2315 : * (1) must be in the form (indexkey op const) or (const op indexkey);
2316 : * and
2317 : * (2) must contain an operator which is in the index's operator family
2318 : * for this column; and
2319 : * (3) must match the collation of the index, if collation is relevant.
2320 : *
2321 : * Our definition of "const" is exceedingly liberal: we allow anything that
2322 : * doesn't involve a volatile function or a Var of the index's relation.
2323 : * In particular, Vars belonging to other relations of the query are
2324 : * accepted here, since a clause of that form can be used in a
2325 : * parameterized indexscan. It's the responsibility of higher code levels
2326 : * to manage restriction and join clauses appropriately.
2327 : *
2328 : * Note: we do need to check for Vars of the index's relation on the
2329 : * "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
2330 : * are not processable by a parameterized indexscan on a.f1, whereas
2331 : * something like (a.f1 OP (b.f2 OP c.f3)) is.
2332 : *
2333 : * Presently, the executor can only deal with indexquals that have the
2334 : * indexkey on the left, so we can only use clauses that have the indexkey
2335 : * on the right if we can commute the clause to put the key on the left.
2336 : * We handle that by generating an IndexClause with the correctly-commuted
2337 : * opclause as a derived indexqual.
2338 : *
2339 : * If the index has a collation, the clause must have the same collation.
2340 : * For collation-less indexes, we assume it doesn't matter; this is
2341 : * necessary for cases like "hstore ? text", wherein hstore's operators
2342 : * don't care about collation but the clause will get marked with a
2343 : * collation anyway because of the text argument. (This logic is
2344 : * embodied in the macro IndexCollMatchesExprColl.)
2345 : *
2346 : * It is also possible to match RowCompareExpr clauses to indexes (but
2347 : * currently, only btree indexes handle this).
2348 : *
2349 : * It is also possible to match ScalarArrayOpExpr clauses to indexes, when
2350 : * the clause is of the form "indexkey op ANY (arrayconst)".
2351 : *
2352 : * For boolean indexes, it is also possible to match the clause directly
2353 : * to the indexkey; or perhaps the clause is (NOT indexkey).
2354 : *
2355 : * And, last but not least, some operators and functions can be processed
2356 : * to derive (typically lossy) indexquals from a clause that isn't in
2357 : * itself indexable. If we see that any operand of an OpExpr or FuncExpr
2358 : * matches the index key, and the function has a planner support function
2359 : * attached to it, we'll invoke the support function to see if such an
2360 : * indexqual can be built.
2361 : *
2362 : * 'rinfo' is the clause to be tested (as a RestrictInfo node).
2363 : * 'indexcol' is a column number of 'index' (counting from 0).
2364 : * 'index' is the index of interest.
2365 : *
2366 : * Returns an IndexClause if the clause can be used with this index key,
2367 : * or NULL if not.
2368 : *
2369 : * NOTE: returns NULL if clause is an OR or AND clause; it is the
2370 : * responsibility of higher-level routines to cope with those.
2371 : */
2372 : static IndexClause *
2373 789668 : match_clause_to_indexcol(PlannerInfo *root,
2374 : RestrictInfo *rinfo,
2375 : int indexcol,
2376 : IndexOptInfo *index)
2377 : {
2378 : IndexClause *iclause;
2379 789668 : Expr *clause = rinfo->clause;
2380 : Oid opfamily;
2381 :
2382 : Assert(indexcol < index->nkeycolumns);
2383 :
2384 : /*
2385 : * Historically this code has coped with NULL clauses. That's probably
2386 : * not possible anymore, but we might as well continue to cope.
2387 : */
2388 789668 : if (clause == NULL)
2389 0 : return NULL;
2390 :
2391 : /* First check for boolean-index cases. */
2392 789668 : opfamily = index->opfamily[indexcol];
2393 789668 : if (IsBooleanOpfamily(opfamily))
2394 : {
2395 80 : iclause = match_boolean_index_clause(rinfo, indexcol, index);
2396 80 : if (iclause)
2397 52 : return iclause;
2398 : }
2399 :
2400 : /*
2401 : * Clause must be an opclause, funcclause, ScalarArrayOpExpr, or
2402 : * RowCompareExpr. Or, if the index supports it, we can handle IS
2403 : * NULL/NOT NULL clauses.
2404 : */
2405 789616 : if (IsA(clause, OpExpr))
2406 : {
2407 635058 : return match_opclause_to_indexcol(root, rinfo, indexcol, index);
2408 : }
2409 154558 : else if (IsA(clause, FuncExpr))
2410 : {
2411 11128 : return match_funcclause_to_indexcol(root, rinfo, indexcol, index);
2412 : }
2413 143430 : else if (IsA(clause, ScalarArrayOpExpr))
2414 : {
2415 50060 : return match_saopclause_to_indexcol(rinfo, indexcol, index);
2416 : }
2417 93370 : else if (IsA(clause, RowCompareExpr))
2418 : {
2419 192 : return match_rowcompare_to_indexcol(rinfo, indexcol, index);
2420 : }
2421 93178 : else if (index->amsearchnulls && IsA(clause, NullTest))
2422 : {
2423 25036 : NullTest *nt = (NullTest *) clause;
2424 :
2425 50072 : if (!nt->argisrow &&
2426 25036 : match_index_to_operand((Node *) nt->arg, indexcol, index))
2427 : {
2428 906 : iclause = makeNode(IndexClause);
2429 906 : iclause->rinfo = rinfo;
2430 906 : iclause->indexquals = list_make1(rinfo);
2431 906 : iclause->lossy = false;
2432 906 : iclause->indexcol = indexcol;
2433 906 : iclause->indexcols = NIL;
2434 906 : return iclause;
2435 : }
2436 : }
2437 :
2438 92272 : return NULL;
2439 : }
2440 :
2441 : /*
2442 : * match_boolean_index_clause
2443 : * Recognize restriction clauses that can be matched to a boolean index.
2444 : *
2445 : * The idea here is that, for an index on a boolean column that supports the
2446 : * BooleanEqualOperator, we can transform a plain reference to the indexkey
2447 : * into "indexkey = true", or "NOT indexkey" into "indexkey = false", etc,
2448 : * so as to make the expression indexable using the index's "=" operator.
2449 : * Since Postgres 8.1, we must do this because constant simplification does
2450 : * the reverse transformation; without this code there'd be no way to use
2451 : * such an index at all.
2452 : *
2453 : * This should be called only when IsBooleanOpfamily() recognizes the
2454 : * index's operator family. We check to see if the clause matches the
2455 : * index's key, and if so, build a suitable IndexClause.
2456 : */
2457 : static IndexClause *
2458 176 : match_boolean_index_clause(RestrictInfo *rinfo,
2459 : int indexcol,
2460 : IndexOptInfo *index)
2461 : {
2462 176 : Node *clause = (Node *) rinfo->clause;
2463 176 : Expr *op = NULL;
2464 :
2465 : /* Direct match? */
2466 176 : if (match_index_to_operand(clause, indexcol, index))
2467 : {
2468 : /* convert to indexkey = TRUE */
2469 56 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2470 : (Expr *) clause,
2471 56 : (Expr *) makeBoolConst(true, false),
2472 : InvalidOid, InvalidOid);
2473 : }
2474 : /* NOT clause? */
2475 120 : else if (is_notclause(clause))
2476 : {
2477 44 : Node *arg = (Node *) get_notclausearg((Expr *) clause);
2478 :
2479 44 : if (match_index_to_operand(arg, indexcol, index))
2480 : {
2481 : /* convert to indexkey = FALSE */
2482 44 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2483 : (Expr *) arg,
2484 44 : (Expr *) makeBoolConst(false, false),
2485 : InvalidOid, InvalidOid);
2486 : }
2487 : }
2488 :
2489 : /*
2490 : * Since we only consider clauses at top level of WHERE, we can convert
2491 : * indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
2492 : * different meaning for NULL isn't important.
2493 : */
2494 76 : else if (clause && IsA(clause, BooleanTest))
2495 : {
2496 24 : BooleanTest *btest = (BooleanTest *) clause;
2497 24 : Node *arg = (Node *) btest->arg;
2498 :
2499 36 : if (btest->booltesttype == IS_TRUE &&
2500 12 : match_index_to_operand(arg, indexcol, index))
2501 : {
2502 : /* convert to indexkey = TRUE */
2503 12 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2504 : (Expr *) arg,
2505 12 : (Expr *) makeBoolConst(true, false),
2506 : InvalidOid, InvalidOid);
2507 : }
2508 24 : else if (btest->booltesttype == IS_FALSE &&
2509 12 : match_index_to_operand(arg, indexcol, index))
2510 : {
2511 : /* convert to indexkey = FALSE */
2512 12 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2513 : (Expr *) arg,
2514 12 : (Expr *) makeBoolConst(false, false),
2515 : InvalidOid, InvalidOid);
2516 : }
2517 : }
2518 :
2519 : /*
2520 : * If we successfully made an operator clause from the given qual, we must
2521 : * wrap it in an IndexClause. It's not lossy.
2522 : */
2523 176 : if (op)
2524 : {
2525 124 : IndexClause *iclause = makeNode(IndexClause);
2526 :
2527 124 : iclause->rinfo = rinfo;
2528 124 : iclause->indexquals = list_make1(make_simple_restrictinfo(op));
2529 124 : iclause->lossy = false;
2530 124 : iclause->indexcol = indexcol;
2531 124 : iclause->indexcols = NIL;
2532 124 : return iclause;
2533 : }
2534 :
2535 52 : return NULL;
2536 : }
2537 :
2538 : /*
2539 : * match_opclause_to_indexcol()
2540 : * Handles the OpExpr case for match_clause_to_indexcol(),
2541 : * which see for comments.
2542 : */
2543 : static IndexClause *
2544 635058 : match_opclause_to_indexcol(PlannerInfo *root,
2545 : RestrictInfo *rinfo,
2546 : int indexcol,
2547 : IndexOptInfo *index)
2548 : {
2549 : IndexClause *iclause;
2550 635058 : OpExpr *clause = (OpExpr *) rinfo->clause;
2551 : Node *leftop,
2552 : *rightop;
2553 : Oid expr_op;
2554 : Oid expr_coll;
2555 : Index index_relid;
2556 : Oid opfamily;
2557 : Oid idxcollation;
2558 :
2559 : /*
2560 : * Only binary operators need apply. (In theory, a planner support
2561 : * function could do something with a unary operator, but it seems
2562 : * unlikely to be worth the cycles to check.)
2563 : */
2564 635058 : if (list_length(clause->args) != 2)
2565 0 : return NULL;
2566 :
2567 635058 : leftop = (Node *) linitial(clause->args);
2568 635058 : rightop = (Node *) lsecond(clause->args);
2569 635058 : expr_op = clause->opno;
2570 635058 : expr_coll = clause->inputcollid;
2571 :
2572 635058 : index_relid = index->rel->relid;
2573 635058 : opfamily = index->opfamily[indexcol];
2574 635058 : idxcollation = index->indexcollations[indexcol];
2575 :
2576 : /*
2577 : * Check for clauses of the form: (indexkey operator constant) or
2578 : * (constant operator indexkey). See match_clause_to_indexcol's notes
2579 : * about const-ness.
2580 : *
2581 : * Note that we don't ask the support function about clauses that don't
2582 : * have one of these forms. Again, in principle it might be possible to
2583 : * do something, but it seems unlikely to be worth the cycles to check.
2584 : */
2585 819386 : if (match_index_to_operand(leftop, indexcol, index) &&
2586 368592 : !bms_is_member(index_relid, rinfo->right_relids) &&
2587 184264 : !contain_volatile_functions(rightop))
2588 : {
2589 366418 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
2590 182154 : op_in_opfamily(expr_op, opfamily))
2591 : {
2592 177850 : iclause = makeNode(IndexClause);
2593 177850 : iclause->rinfo = rinfo;
2594 177850 : iclause->indexquals = list_make1(rinfo);
2595 177850 : iclause->lossy = false;
2596 177850 : iclause->indexcol = indexcol;
2597 177850 : iclause->indexcols = NIL;
2598 177850 : return iclause;
2599 : }
2600 :
2601 : /*
2602 : * If we didn't find a member of the index's opfamily, try the support
2603 : * function for the operator's underlying function.
2604 : */
2605 6414 : set_opfuncid(clause); /* make sure we have opfuncid */
2606 6414 : return get_index_clause_from_support(root,
2607 : rinfo,
2608 : clause->opfuncid,
2609 : 0, /* indexarg on left */
2610 : indexcol,
2611 : index);
2612 : }
2613 :
2614 469474 : if (match_index_to_operand(rightop, indexcol, index) &&
2615 37324 : !bms_is_member(index_relid, rinfo->left_relids) &&
2616 18644 : !contain_volatile_functions(leftop))
2617 : {
2618 18644 : if (IndexCollMatchesExprColl(idxcollation, expr_coll))
2619 : {
2620 18644 : Oid comm_op = get_commutator(expr_op);
2621 :
2622 37288 : if (OidIsValid(comm_op) &&
2623 18644 : op_in_opfamily(comm_op, opfamily))
2624 : {
2625 : RestrictInfo *commrinfo;
2626 :
2627 : /* Build a commuted OpExpr and RestrictInfo */
2628 18416 : commrinfo = commute_restrictinfo(rinfo, comm_op);
2629 :
2630 : /* Make an IndexClause showing that as a derived qual */
2631 18416 : iclause = makeNode(IndexClause);
2632 18416 : iclause->rinfo = rinfo;
2633 18416 : iclause->indexquals = list_make1(commrinfo);
2634 18416 : iclause->lossy = false;
2635 18416 : iclause->indexcol = indexcol;
2636 18416 : iclause->indexcols = NIL;
2637 18416 : return iclause;
2638 : }
2639 : }
2640 :
2641 : /*
2642 : * If we didn't find a member of the index's opfamily, try the support
2643 : * function for the operator's underlying function.
2644 : */
2645 228 : set_opfuncid(clause); /* make sure we have opfuncid */
2646 228 : return get_index_clause_from_support(root,
2647 : rinfo,
2648 : clause->opfuncid,
2649 : 1, /* indexarg on right */
2650 : indexcol,
2651 : index);
2652 : }
2653 :
2654 432150 : return NULL;
2655 : }
2656 :
2657 : /*
2658 : * match_funcclause_to_indexcol()
2659 : * Handles the FuncExpr case for match_clause_to_indexcol(),
2660 : * which see for comments.
2661 : */
2662 : static IndexClause *
2663 11128 : match_funcclause_to_indexcol(PlannerInfo *root,
2664 : RestrictInfo *rinfo,
2665 : int indexcol,
2666 : IndexOptInfo *index)
2667 : {
2668 11128 : FuncExpr *clause = (FuncExpr *) rinfo->clause;
2669 : int indexarg;
2670 : ListCell *lc;
2671 :
2672 : /*
2673 : * We have no built-in intelligence about function clauses, but if there's
2674 : * a planner support function, it might be able to do something. But, to
2675 : * cut down on wasted planning cycles, only call the support function if
2676 : * at least one argument matches the target index column.
2677 : *
2678 : * Note that we don't insist on the other arguments being pseudoconstants;
2679 : * the support function has to check that. This is to allow cases where
2680 : * only some of the other arguments need to be included in the indexqual.
2681 : */
2682 11128 : indexarg = 0;
2683 24062 : foreach(lc, clause->args)
2684 : {
2685 14776 : Node *op = (Node *) lfirst(lc);
2686 :
2687 14776 : if (match_index_to_operand(op, indexcol, index))
2688 : {
2689 1842 : return get_index_clause_from_support(root,
2690 : rinfo,
2691 : clause->funcid,
2692 : indexarg,
2693 : indexcol,
2694 : index);
2695 : }
2696 :
2697 12934 : indexarg++;
2698 : }
2699 :
2700 9286 : return NULL;
2701 : }
2702 :
2703 : /*
2704 : * get_index_clause_from_support()
2705 : * If the function has a planner support function, try to construct
2706 : * an IndexClause using indexquals created by the support function.
2707 : */
2708 : static IndexClause *
2709 8484 : get_index_clause_from_support(PlannerInfo *root,
2710 : RestrictInfo *rinfo,
2711 : Oid funcid,
2712 : int indexarg,
2713 : int indexcol,
2714 : IndexOptInfo *index)
2715 : {
2716 8484 : Oid prosupport = get_func_support(funcid);
2717 : SupportRequestIndexCondition req;
2718 : List *sresult;
2719 :
2720 8484 : if (!OidIsValid(prosupport))
2721 5356 : return NULL;
2722 :
2723 3128 : req.type = T_SupportRequestIndexCondition;
2724 3128 : req.root = root;
2725 3128 : req.funcid = funcid;
2726 3128 : req.node = (Node *) rinfo->clause;
2727 3128 : req.indexarg = indexarg;
2728 3128 : req.index = index;
2729 3128 : req.indexcol = indexcol;
2730 3128 : req.opfamily = index->opfamily[indexcol];
2731 3128 : req.indexcollation = index->indexcollations[indexcol];
2732 :
2733 3128 : req.lossy = true; /* default assumption */
2734 :
2735 3128 : sresult = (List *)
2736 3128 : DatumGetPointer(OidFunctionCall1(prosupport,
2737 : PointerGetDatum(&req)));
2738 :
2739 3128 : if (sresult != NIL)
2740 : {
2741 3002 : IndexClause *iclause = makeNode(IndexClause);
2742 3002 : List *indexquals = NIL;
2743 : ListCell *lc;
2744 :
2745 : /*
2746 : * The support function API says it should just give back bare
2747 : * clauses, so here we must wrap each one in a RestrictInfo.
2748 : */
2749 6930 : foreach(lc, sresult)
2750 : {
2751 3928 : Expr *clause = (Expr *) lfirst(lc);
2752 :
2753 3928 : indexquals = lappend(indexquals, make_simple_restrictinfo(clause));
2754 : }
2755 :
2756 3002 : iclause->rinfo = rinfo;
2757 3002 : iclause->indexquals = indexquals;
2758 3002 : iclause->lossy = req.lossy;
2759 3002 : iclause->indexcol = indexcol;
2760 3002 : iclause->indexcols = NIL;
2761 :
2762 3002 : return iclause;
2763 : }
2764 :
2765 126 : return NULL;
2766 : }
2767 :
2768 : /*
2769 : * match_saopclause_to_indexcol()
2770 : * Handles the ScalarArrayOpExpr case for match_clause_to_indexcol(),
2771 : * which see for comments.
2772 : */
2773 : static IndexClause *
2774 50060 : match_saopclause_to_indexcol(RestrictInfo *rinfo,
2775 : int indexcol,
2776 : IndexOptInfo *index)
2777 : {
2778 50060 : ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
2779 : Node *leftop,
2780 : *rightop;
2781 : Relids right_relids;
2782 : Oid expr_op;
2783 : Oid expr_coll;
2784 : Index index_relid;
2785 : Oid opfamily;
2786 : Oid idxcollation;
2787 :
2788 : /* We only accept ANY clauses, not ALL */
2789 50060 : if (!saop->useOr)
2790 3158 : return NULL;
2791 46902 : leftop = (Node *) linitial(saop->args);
2792 46902 : rightop = (Node *) lsecond(saop->args);
2793 46902 : right_relids = pull_varnos(rightop);
2794 46902 : expr_op = saop->opno;
2795 46902 : expr_coll = saop->inputcollid;
2796 :
2797 46902 : index_relid = index->rel->relid;
2798 46902 : opfamily = index->opfamily[indexcol];
2799 46902 : idxcollation = index->indexcollations[indexcol];
2800 :
2801 : /*
2802 : * We must have indexkey on the left and a pseudo-constant array argument.
2803 : */
2804 53654 : if (match_index_to_operand(leftop, indexcol, index) &&
2805 13504 : !bms_is_member(index_relid, right_relids) &&
2806 6752 : !contain_volatile_functions(rightop))
2807 : {
2808 13500 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
2809 6748 : op_in_opfamily(expr_op, opfamily))
2810 : {
2811 6740 : IndexClause *iclause = makeNode(IndexClause);
2812 :
2813 6740 : iclause->rinfo = rinfo;
2814 6740 : iclause->indexquals = list_make1(rinfo);
2815 6740 : iclause->lossy = false;
2816 6740 : iclause->indexcol = indexcol;
2817 6740 : iclause->indexcols = NIL;
2818 6740 : return iclause;
2819 : }
2820 :
2821 : /*
2822 : * We do not currently ask support functions about ScalarArrayOpExprs,
2823 : * though in principle we could.
2824 : */
2825 : }
2826 :
2827 40162 : return NULL;
2828 : }
2829 :
2830 : /*
2831 : * match_rowcompare_to_indexcol()
2832 : * Handles the RowCompareExpr case for match_clause_to_indexcol(),
2833 : * which see for comments.
2834 : *
2835 : * In this routine we check whether the first column of the row comparison
2836 : * matches the target index column. This is sufficient to guarantee that some
2837 : * index condition can be constructed from the RowCompareExpr --- the rest
2838 : * is handled by expand_indexqual_rowcompare().
2839 : */
2840 : static IndexClause *
2841 192 : match_rowcompare_to_indexcol(RestrictInfo *rinfo,
2842 : int indexcol,
2843 : IndexOptInfo *index)
2844 : {
2845 192 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
2846 : Index index_relid;
2847 : Oid opfamily;
2848 : Oid idxcollation;
2849 : Node *leftop,
2850 : *rightop;
2851 : bool var_on_left;
2852 : Oid expr_op;
2853 : Oid expr_coll;
2854 :
2855 : /* Forget it if we're not dealing with a btree index */
2856 192 : if (index->relam != BTREE_AM_OID)
2857 0 : return NULL;
2858 :
2859 192 : index_relid = index->rel->relid;
2860 192 : opfamily = index->opfamily[indexcol];
2861 192 : idxcollation = index->indexcollations[indexcol];
2862 :
2863 : /*
2864 : * We could do the matching on the basis of insisting that the opfamily
2865 : * shown in the RowCompareExpr be the same as the index column's opfamily,
2866 : * but that could fail in the presence of reverse-sort opfamilies: it'd be
2867 : * a matter of chance whether RowCompareExpr had picked the forward or
2868 : * reverse-sort family. So look only at the operator, and match if it is
2869 : * a member of the index's opfamily (after commutation, if the indexkey is
2870 : * on the right). We'll worry later about whether any additional
2871 : * operators are matchable to the index.
2872 : */
2873 192 : leftop = (Node *) linitial(clause->largs);
2874 192 : rightop = (Node *) linitial(clause->rargs);
2875 192 : expr_op = linitial_oid(clause->opnos);
2876 192 : expr_coll = linitial_oid(clause->inputcollids);
2877 :
2878 : /* Collations must match, if relevant */
2879 192 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
2880 0 : return NULL;
2881 :
2882 : /*
2883 : * These syntactic tests are the same as in match_opclause_to_indexcol()
2884 : */
2885 236 : if (match_index_to_operand(leftop, indexcol, index) &&
2886 88 : !bms_is_member(index_relid, pull_varnos(rightop)) &&
2887 44 : !contain_volatile_functions(rightop))
2888 : {
2889 : /* OK, indexkey is on left */
2890 44 : var_on_left = true;
2891 : }
2892 164 : else if (match_index_to_operand(rightop, indexcol, index) &&
2893 32 : !bms_is_member(index_relid, pull_varnos(leftop)) &&
2894 16 : !contain_volatile_functions(leftop))
2895 : {
2896 : /* indexkey is on right, so commute the operator */
2897 16 : expr_op = get_commutator(expr_op);
2898 16 : if (expr_op == InvalidOid)
2899 0 : return NULL;
2900 16 : var_on_left = false;
2901 : }
2902 : else
2903 132 : return NULL;
2904 :
2905 : /* We're good if the operator is the right type of opfamily member */
2906 60 : switch (get_op_opfamily_strategy(expr_op, opfamily))
2907 : {
2908 : case BTLessStrategyNumber:
2909 : case BTLessEqualStrategyNumber:
2910 : case BTGreaterEqualStrategyNumber:
2911 : case BTGreaterStrategyNumber:
2912 60 : return expand_indexqual_rowcompare(rinfo,
2913 : indexcol,
2914 : index,
2915 : expr_op,
2916 : var_on_left);
2917 : }
2918 :
2919 0 : return NULL;
2920 : }
2921 :
2922 : /*
2923 : * expand_indexqual_rowcompare --- expand a single indexqual condition
2924 : * that is a RowCompareExpr
2925 : *
2926 : * It's already known that the first column of the row comparison matches
2927 : * the specified column of the index. We can use additional columns of the
2928 : * row comparison as index qualifications, so long as they match the index
2929 : * in the "same direction", ie, the indexkeys are all on the same side of the
2930 : * clause and the operators are all the same-type members of the opfamilies.
2931 : *
2932 : * If all the columns of the RowCompareExpr match in this way, we just use it
2933 : * as-is, except for possibly commuting it to put the indexkeys on the left.
2934 : *
2935 : * Otherwise, we build a shortened RowCompareExpr (if more than one
2936 : * column matches) or a simple OpExpr (if the first-column match is all
2937 : * there is). In these cases the modified clause is always "<=" or ">="
2938 : * even when the original was "<" or ">" --- this is necessary to match all
2939 : * the rows that could match the original. (We are building a lossy version
2940 : * of the row comparison when we do this, so we set lossy = true.)
2941 : *
2942 : * Note: this is really just the last half of match_rowcompare_to_indexcol,
2943 : * but we split it out for comprehensibility.
2944 : */
2945 : static IndexClause *
2946 60 : expand_indexqual_rowcompare(RestrictInfo *rinfo,
2947 : int indexcol,
2948 : IndexOptInfo *index,
2949 : Oid expr_op,
2950 : bool var_on_left)
2951 : {
2952 60 : IndexClause *iclause = makeNode(IndexClause);
2953 60 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
2954 : int op_strategy;
2955 : Oid op_lefttype;
2956 : Oid op_righttype;
2957 : int matching_cols;
2958 : List *expr_ops;
2959 : List *opfamilies;
2960 : List *lefttypes;
2961 : List *righttypes;
2962 : List *new_ops;
2963 : List *var_args;
2964 : List *non_var_args;
2965 :
2966 60 : iclause->rinfo = rinfo;
2967 60 : iclause->indexcol = indexcol;
2968 :
2969 60 : if (var_on_left)
2970 : {
2971 44 : var_args = clause->largs;
2972 44 : non_var_args = clause->rargs;
2973 : }
2974 : else
2975 : {
2976 16 : var_args = clause->rargs;
2977 16 : non_var_args = clause->largs;
2978 : }
2979 :
2980 60 : get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
2981 : &op_strategy,
2982 : &op_lefttype,
2983 : &op_righttype);
2984 :
2985 : /* Initialize returned list of which index columns are used */
2986 60 : iclause->indexcols = list_make1_int(indexcol);
2987 :
2988 : /* Build lists of ops, opfamilies and operator datatypes in case needed */
2989 60 : expr_ops = list_make1_oid(expr_op);
2990 60 : opfamilies = list_make1_oid(index->opfamily[indexcol]);
2991 60 : lefttypes = list_make1_oid(op_lefttype);
2992 60 : righttypes = list_make1_oid(op_righttype);
2993 :
2994 : /*
2995 : * See how many of the remaining columns match some index column in the
2996 : * same way. As in match_clause_to_indexcol(), the "other" side of any
2997 : * potential index condition is OK as long as it doesn't use Vars from the
2998 : * indexed relation.
2999 : */
3000 60 : matching_cols = 1;
3001 :
3002 168 : while (matching_cols < list_length(var_args))
3003 : {
3004 84 : Node *varop = (Node *) list_nth(var_args, matching_cols);
3005 84 : Node *constop = (Node *) list_nth(non_var_args, matching_cols);
3006 : int i;
3007 :
3008 84 : expr_op = list_nth_oid(clause->opnos, matching_cols);
3009 84 : if (!var_on_left)
3010 : {
3011 : /* indexkey is on right, so commute the operator */
3012 16 : expr_op = get_commutator(expr_op);
3013 16 : if (expr_op == InvalidOid)
3014 0 : break; /* operator is not usable */
3015 : }
3016 84 : if (bms_is_member(index->rel->relid, pull_varnos(constop)))
3017 0 : break; /* no good, Var on wrong side */
3018 84 : if (contain_volatile_functions(constop))
3019 0 : break; /* no good, volatile comparison value */
3020 :
3021 : /*
3022 : * The Var side can match any key column of the index.
3023 : */
3024 200 : for (i = 0; i < index->nkeycolumns; i++)
3025 : {
3026 212 : if (match_index_to_operand(varop, i, index) &&
3027 48 : get_op_opfamily_strategy(expr_op,
3028 144 : index->opfamily[i]) == op_strategy &&
3029 56 : IndexCollMatchesExprColl(index->indexcollations[i],
3030 : list_nth_oid(clause->inputcollids,
3031 : matching_cols)))
3032 : break;
3033 : }
3034 84 : if (i >= index->nkeycolumns)
3035 36 : break; /* no match found */
3036 :
3037 : /* Add column number to returned list */
3038 48 : iclause->indexcols = lappend_int(iclause->indexcols, i);
3039 :
3040 : /* Add operator info to lists */
3041 48 : get_op_opfamily_properties(expr_op, index->opfamily[i], false,
3042 : &op_strategy,
3043 : &op_lefttype,
3044 : &op_righttype);
3045 48 : expr_ops = lappend_oid(expr_ops, expr_op);
3046 48 : opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
3047 48 : lefttypes = lappend_oid(lefttypes, op_lefttype);
3048 48 : righttypes = lappend_oid(righttypes, op_righttype);
3049 :
3050 : /* This column matches, keep scanning */
3051 48 : matching_cols++;
3052 : }
3053 :
3054 : /* Result is non-lossy if all columns are usable as index quals */
3055 60 : iclause->lossy = (matching_cols != list_length(clause->opnos));
3056 :
3057 : /*
3058 : * We can use rinfo->clause as-is if we have var on left and it's all
3059 : * usable as index quals.
3060 : */
3061 60 : if (var_on_left && !iclause->lossy)
3062 16 : iclause->indexquals = list_make1(rinfo);
3063 : else
3064 : {
3065 : /*
3066 : * We have to generate a modified rowcompare (possibly just one
3067 : * OpExpr). The painful part of this is changing < to <= or > to >=,
3068 : * so deal with that first.
3069 : */
3070 44 : if (!iclause->lossy)
3071 : {
3072 : /* very easy, just use the commuted operators */
3073 8 : new_ops = expr_ops;
3074 : }
3075 72 : else if (op_strategy == BTLessEqualStrategyNumber ||
3076 36 : op_strategy == BTGreaterEqualStrategyNumber)
3077 : {
3078 : /* easy, just use the same (possibly commuted) operators */
3079 0 : new_ops = list_truncate(expr_ops, matching_cols);
3080 : }
3081 : else
3082 : {
3083 : ListCell *opfamilies_cell;
3084 : ListCell *lefttypes_cell;
3085 : ListCell *righttypes_cell;
3086 :
3087 36 : if (op_strategy == BTLessStrategyNumber)
3088 20 : op_strategy = BTLessEqualStrategyNumber;
3089 16 : else if (op_strategy == BTGreaterStrategyNumber)
3090 16 : op_strategy = BTGreaterEqualStrategyNumber;
3091 : else
3092 0 : elog(ERROR, "unexpected strategy number %d", op_strategy);
3093 36 : new_ops = NIL;
3094 96 : forthree(opfamilies_cell, opfamilies,
3095 : lefttypes_cell, lefttypes,
3096 : righttypes_cell, righttypes)
3097 : {
3098 60 : Oid opfam = lfirst_oid(opfamilies_cell);
3099 60 : Oid lefttype = lfirst_oid(lefttypes_cell);
3100 60 : Oid righttype = lfirst_oid(righttypes_cell);
3101 :
3102 60 : expr_op = get_opfamily_member(opfam, lefttype, righttype,
3103 : op_strategy);
3104 60 : if (!OidIsValid(expr_op)) /* should not happen */
3105 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3106 : op_strategy, lefttype, righttype, opfam);
3107 60 : new_ops = lappend_oid(new_ops, expr_op);
3108 : }
3109 : }
3110 :
3111 : /* If we have more than one matching col, create a subset rowcompare */
3112 44 : if (matching_cols > 1)
3113 : {
3114 32 : RowCompareExpr *rc = makeNode(RowCompareExpr);
3115 :
3116 32 : rc->rctype = (RowCompareType) op_strategy;
3117 32 : rc->opnos = new_ops;
3118 32 : rc->opfamilies = list_truncate(list_copy(clause->opfamilies),
3119 : matching_cols);
3120 32 : rc->inputcollids = list_truncate(list_copy(clause->inputcollids),
3121 : matching_cols);
3122 32 : rc->largs = list_truncate(copyObject(var_args),
3123 : matching_cols);
3124 32 : rc->rargs = list_truncate(copyObject(non_var_args),
3125 : matching_cols);
3126 32 : iclause->indexquals = list_make1(make_simple_restrictinfo((Expr *) rc));
3127 : }
3128 : else
3129 : {
3130 : Expr *op;
3131 :
3132 : /* We don't report an index column list in this case */
3133 12 : iclause->indexcols = NIL;
3134 :
3135 24 : op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
3136 12 : copyObject(linitial(var_args)),
3137 12 : copyObject(linitial(non_var_args)),
3138 : InvalidOid,
3139 12 : linitial_oid(clause->inputcollids));
3140 12 : iclause->indexquals = list_make1(make_simple_restrictinfo(op));
3141 : }
3142 : }
3143 :
3144 60 : return iclause;
3145 : }
3146 :
3147 :
3148 : /****************************************************************************
3149 : * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3150 : ****************************************************************************/
3151 :
3152 : /*
3153 : * match_pathkeys_to_index
3154 : * Test whether an index can produce output ordered according to the
3155 : * given pathkeys using "ordering operators".
3156 : *
3157 : * If it can, return a list of suitable ORDER BY expressions, each of the form
3158 : * "indexedcol operator pseudoconstant", along with an integer list of the
3159 : * index column numbers (zero based) that each clause would be used with.
3160 : * NIL lists are returned if the ordering is not achievable this way.
3161 : *
3162 : * On success, the result list is ordered by pathkeys, and in fact is
3163 : * one-to-one with the requested pathkeys.
3164 : */
3165 : static void
3166 538 : match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3167 : List **orderby_clauses_p,
3168 : List **clause_columns_p)
3169 : {
3170 538 : List *orderby_clauses = NIL;
3171 538 : List *clause_columns = NIL;
3172 : ListCell *lc1;
3173 :
3174 538 : *orderby_clauses_p = NIL; /* set default results */
3175 538 : *clause_columns_p = NIL;
3176 :
3177 : /* Only indexes with the amcanorderbyop property are interesting here */
3178 538 : if (!index->amcanorderbyop)
3179 0 : return;
3180 :
3181 846 : foreach(lc1, pathkeys)
3182 : {
3183 526 : PathKey *pathkey = (PathKey *) lfirst(lc1);
3184 526 : bool found = false;
3185 : ListCell *lc2;
3186 :
3187 : /*
3188 : * Note: for any failure to match, we just return NIL immediately.
3189 : * There is no value in matching just some of the pathkeys.
3190 : */
3191 :
3192 : /* Pathkey must request default sort order for the target opfamily */
3193 1030 : if (pathkey->pk_strategy != BTLessStrategyNumber ||
3194 504 : pathkey->pk_nulls_first)
3195 240 : return;
3196 :
3197 : /* If eclass is volatile, no hope of using an indexscan */
3198 504 : if (pathkey->pk_eclass->ec_has_volatile)
3199 0 : return;
3200 :
3201 : /*
3202 : * Try to match eclass member expression(s) to index. Note that child
3203 : * EC members are considered, but only when they belong to the target
3204 : * relation. (Unlike regular members, the same expression could be a
3205 : * child member of more than one EC. Therefore, the same index could
3206 : * be considered to match more than one pathkey list, which is OK
3207 : * here. See also get_eclass_for_sort_expr.)
3208 : */
3209 700 : foreach(lc2, pathkey->pk_eclass->ec_members)
3210 : {
3211 504 : EquivalenceMember *member = (EquivalenceMember *) lfirst(lc2);
3212 : int indexcol;
3213 :
3214 : /* No possibility of match if it references other relations */
3215 504 : if (!bms_equal(member->em_relids, index->rel->relids))
3216 0 : continue;
3217 :
3218 : /*
3219 : * We allow any column of the index to match each pathkey; they
3220 : * don't have to match left-to-right as you might expect. This is
3221 : * correct for GiST, and it doesn't matter for SP-GiST because
3222 : * that doesn't handle multiple columns anyway, and no other
3223 : * existing AMs support amcanorderbyop. We might need different
3224 : * logic in future for other implementations.
3225 : */
3226 700 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3227 : {
3228 : Expr *expr;
3229 :
3230 504 : expr = match_clause_to_ordering_op(index,
3231 : indexcol,
3232 : member->em_expr,
3233 : pathkey->pk_opfamily);
3234 504 : if (expr)
3235 : {
3236 308 : orderby_clauses = lappend(orderby_clauses, expr);
3237 308 : clause_columns = lappend_int(clause_columns, indexcol);
3238 308 : found = true;
3239 308 : break;
3240 : }
3241 : }
3242 :
3243 504 : if (found) /* don't want to look at remaining members */
3244 308 : break;
3245 : }
3246 :
3247 504 : if (!found) /* fail if no match for this pathkey */
3248 196 : return;
3249 : }
3250 :
3251 320 : *orderby_clauses_p = orderby_clauses; /* success! */
3252 320 : *clause_columns_p = clause_columns;
3253 : }
3254 :
3255 : /*
3256 : * match_clause_to_ordering_op
3257 : * Determines whether an ordering operator expression matches an
3258 : * index column.
3259 : *
3260 : * This is similar to, but simpler than, match_clause_to_indexcol.
3261 : * We only care about simple OpExpr cases. The input is a bare
3262 : * expression that is being ordered by, which must be of the form
3263 : * (indexkey op const) or (const op indexkey) where op is an ordering
3264 : * operator for the column's opfamily.
3265 : *
3266 : * 'index' is the index of interest.
3267 : * 'indexcol' is a column number of 'index' (counting from 0).
3268 : * 'clause' is the ordering expression to be tested.
3269 : * 'pk_opfamily' is the btree opfamily describing the required sort order.
3270 : *
3271 : * Note that we currently do not consider the collation of the ordering
3272 : * operator's result. In practical cases the result type will be numeric
3273 : * and thus have no collation, and it's not very clear what to match to
3274 : * if it did have a collation. The index's collation should match the
3275 : * ordering operator's input collation, not its result.
3276 : *
3277 : * If successful, return 'clause' as-is if the indexkey is on the left,
3278 : * otherwise a commuted copy of 'clause'. If no match, return NULL.
3279 : */
3280 : static Expr *
3281 504 : match_clause_to_ordering_op(IndexOptInfo *index,
3282 : int indexcol,
3283 : Expr *clause,
3284 : Oid pk_opfamily)
3285 : {
3286 : Oid opfamily;
3287 : Oid idxcollation;
3288 : Node *leftop,
3289 : *rightop;
3290 : Oid expr_op;
3291 : Oid expr_coll;
3292 : Oid sortfamily;
3293 : bool commuted;
3294 :
3295 : Assert(indexcol < index->nkeycolumns);
3296 :
3297 504 : opfamily = index->opfamily[indexcol];
3298 504 : idxcollation = index->indexcollations[indexcol];
3299 :
3300 : /*
3301 : * Clause must be a binary opclause.
3302 : */
3303 504 : if (!is_opclause(clause))
3304 196 : return NULL;
3305 308 : leftop = get_leftop(clause);
3306 308 : rightop = get_rightop(clause);
3307 308 : if (!leftop || !rightop)
3308 0 : return NULL;
3309 308 : expr_op = ((OpExpr *) clause)->opno;
3310 308 : expr_coll = ((OpExpr *) clause)->inputcollid;
3311 :
3312 : /*
3313 : * We can forget the whole thing right away if wrong collation.
3314 : */
3315 308 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
3316 0 : return NULL;
3317 :
3318 : /*
3319 : * Check for clauses of the form: (indexkey operator constant) or
3320 : * (constant operator indexkey).
3321 : */
3322 600 : if (match_index_to_operand(leftop, indexcol, index) &&
3323 584 : !contain_var_clause(rightop) &&
3324 292 : !contain_volatile_functions(rightop))
3325 : {
3326 292 : commuted = false;
3327 : }
3328 32 : else if (match_index_to_operand(rightop, indexcol, index) &&
3329 32 : !contain_var_clause(leftop) &&
3330 16 : !contain_volatile_functions(leftop))
3331 : {
3332 : /* Might match, but we need a commuted operator */
3333 16 : expr_op = get_commutator(expr_op);
3334 16 : if (expr_op == InvalidOid)
3335 0 : return NULL;
3336 16 : commuted = true;
3337 : }
3338 : else
3339 0 : return NULL;
3340 :
3341 : /*
3342 : * Is the (commuted) operator an ordering operator for the opfamily? And
3343 : * if so, does it yield the right sorting semantics?
3344 : */
3345 308 : sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3346 308 : if (sortfamily != pk_opfamily)
3347 0 : return NULL;
3348 :
3349 : /* We have a match. Return clause or a commuted version thereof. */
3350 308 : if (commuted)
3351 : {
3352 16 : OpExpr *newclause = makeNode(OpExpr);
3353 :
3354 : /* flat-copy all the fields of clause */
3355 16 : memcpy(newclause, clause, sizeof(OpExpr));
3356 :
3357 : /* commute it */
3358 16 : newclause->opno = expr_op;
3359 16 : newclause->opfuncid = InvalidOid;
3360 16 : newclause->args = list_make2(rightop, leftop);
3361 :
3362 16 : clause = (Expr *) newclause;
3363 : }
3364 :
3365 308 : return clause;
3366 : }
3367 :
3368 :
3369 : /****************************************************************************
3370 : * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3371 : ****************************************************************************/
3372 :
3373 : /*
3374 : * check_index_predicates
3375 : * Set the predicate-derived IndexOptInfo fields for each index
3376 : * of the specified relation.
3377 : *
3378 : * predOK is set true if the index is partial and its predicate is satisfied
3379 : * for this query, ie the query's WHERE clauses imply the predicate.
3380 : *
3381 : * indrestrictinfo is set to the relation's baserestrictinfo list less any
3382 : * conditions that are implied by the index's predicate. (Obviously, for a
3383 : * non-partial index, this is the same as baserestrictinfo.) Such conditions
3384 : * can be dropped from the plan when using the index, in certain cases.
3385 : *
3386 : * At one time it was possible for this to get re-run after adding more
3387 : * restrictions to the rel, thus possibly letting us prove more indexes OK.
3388 : * That doesn't happen any more (at least not in the core code's usage),
3389 : * but this code still supports it in case extensions want to mess with the
3390 : * baserestrictinfo list. We assume that adding more restrictions can't make
3391 : * an index not predOK. We must recompute indrestrictinfo each time, though,
3392 : * to make sure any newly-added restrictions get into it if needed.
3393 : */
3394 : void
3395 217124 : check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3396 : {
3397 : List *clauselist;
3398 : bool have_partial;
3399 : bool is_target_rel;
3400 : Relids otherrels;
3401 : ListCell *lc;
3402 :
3403 : /* Indexes are available only on base or "other" member relations. */
3404 : Assert(IS_SIMPLE_REL(rel));
3405 :
3406 : /*
3407 : * Initialize the indrestrictinfo lists to be identical to
3408 : * baserestrictinfo, and check whether there are any partial indexes. If
3409 : * not, this is all we need to do.
3410 : */
3411 217124 : have_partial = false;
3412 591524 : foreach(lc, rel->indexlist)
3413 : {
3414 374400 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3415 :
3416 374400 : index->indrestrictinfo = rel->baserestrictinfo;
3417 374400 : if (index->indpred)
3418 648 : have_partial = true;
3419 : }
3420 217124 : if (!have_partial)
3421 216704 : return;
3422 :
3423 : /*
3424 : * Construct a list of clauses that we can assume true for the purpose of
3425 : * proving the index(es) usable. Restriction clauses for the rel are
3426 : * always usable, and so are any join clauses that are "movable to" this
3427 : * rel. Also, we can consider any EC-derivable join clauses (which must
3428 : * be "movable to" this rel, by definition).
3429 : */
3430 420 : clauselist = list_copy(rel->baserestrictinfo);
3431 :
3432 : /* Scan the rel's join clauses */
3433 420 : foreach(lc, rel->joininfo)
3434 : {
3435 0 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3436 :
3437 : /* Check if clause can be moved to this rel */
3438 0 : if (!join_clause_is_movable_to(rinfo, rel))
3439 0 : continue;
3440 :
3441 0 : clauselist = lappend(clauselist, rinfo);
3442 : }
3443 :
3444 : /*
3445 : * Add on any equivalence-derivable join clauses. Computing the correct
3446 : * relid sets for generate_join_implied_equalities is slightly tricky
3447 : * because the rel could be a child rel rather than a true baserel, and in
3448 : * that case we must remove its parents' relid(s) from all_baserels.
3449 : */
3450 420 : if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
3451 48 : otherrels = bms_difference(root->all_baserels,
3452 48 : find_childrel_parents(root, rel));
3453 : else
3454 372 : otherrels = bms_difference(root->all_baserels, rel->relids);
3455 :
3456 420 : if (!bms_is_empty(otherrels))
3457 26 : clauselist =
3458 : list_concat(clauselist,
3459 26 : generate_join_implied_equalities(root,
3460 26 : bms_union(rel->relids,
3461 : otherrels),
3462 : otherrels,
3463 : rel));
3464 :
3465 : /*
3466 : * Normally we remove quals that are implied by a partial index's
3467 : * predicate from indrestrictinfo, indicating that they need not be
3468 : * checked explicitly by an indexscan plan using this index. However, if
3469 : * the rel is a target relation of UPDATE/DELETE/SELECT FOR UPDATE, we
3470 : * cannot remove such quals from the plan, because they need to be in the
3471 : * plan so that they will be properly rechecked by EvalPlanQual testing.
3472 : * Some day we might want to remove such quals from the main plan anyway
3473 : * and pass them through to EvalPlanQual via a side channel; but for now,
3474 : * we just don't remove implied quals at all for target relations.
3475 : */
3476 732 : is_target_rel = (rel->relid == root->parse->resultRelation ||
3477 312 : get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
3478 :
3479 : /*
3480 : * Now try to prove each index predicate true, and compute the
3481 : * indrestrictinfo lists for partial indexes. Note that we compute the
3482 : * indrestrictinfo list even for non-predOK indexes; this might seem
3483 : * wasteful, but we may be able to use such indexes in OR clauses, cf
3484 : * generate_bitmap_or_paths().
3485 : */
3486 1236 : foreach(lc, rel->indexlist)
3487 : {
3488 816 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3489 : ListCell *lcr;
3490 :
3491 816 : if (index->indpred == NIL)
3492 168 : continue; /* ignore non-partial indexes here */
3493 :
3494 648 : if (!index->predOK) /* don't repeat work if already proven OK */
3495 648 : index->predOK = predicate_implied_by(index->indpred, clauselist,
3496 : false);
3497 :
3498 : /* If rel is an update target, leave indrestrictinfo as set above */
3499 648 : if (is_target_rel)
3500 156 : continue;
3501 :
3502 : /* Else compute indrestrictinfo as the non-implied quals */
3503 492 : index->indrestrictinfo = NIL;
3504 1138 : foreach(lcr, rel->baserestrictinfo)
3505 : {
3506 646 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
3507 :
3508 : /* predicate_implied_by() assumes first arg is immutable */
3509 1292 : if (contain_mutable_functions((Node *) rinfo->clause) ||
3510 646 : !predicate_implied_by(list_make1(rinfo->clause),
3511 : index->indpred, false))
3512 470 : index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
3513 : }
3514 : }
3515 : }
3516 :
3517 : /****************************************************************************
3518 : * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
3519 : ****************************************************************************/
3520 :
3521 : /*
3522 : * ec_member_matches_indexcol
3523 : * Test whether an EquivalenceClass member matches an index column.
3524 : *
3525 : * This is a callback for use by generate_implied_equalities_for_column.
3526 : */
3527 : static bool
3528 131384 : ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
3529 : EquivalenceClass *ec, EquivalenceMember *em,
3530 : void *arg)
3531 : {
3532 131384 : IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
3533 131384 : int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
3534 : Oid curFamily;
3535 : Oid curCollation;
3536 :
3537 : Assert(indexcol < index->nkeycolumns);
3538 :
3539 131384 : curFamily = index->opfamily[indexcol];
3540 131384 : curCollation = index->indexcollations[indexcol];
3541 :
3542 : /*
3543 : * If it's a btree index, we can reject it if its opfamily isn't
3544 : * compatible with the EC, since no clause generated from the EC could be
3545 : * used with the index. For non-btree indexes, we can't easily tell
3546 : * whether clauses generated from the EC could be used with the index, so
3547 : * don't check the opfamily. This might mean we return "true" for a
3548 : * useless EC, so we have to recheck the results of
3549 : * generate_implied_equalities_for_column; see
3550 : * match_eclass_clauses_to_index.
3551 : */
3552 262764 : if (index->relam == BTREE_AM_OID &&
3553 131380 : !list_member_oid(ec->ec_opfamilies, curFamily))
3554 37516 : return false;
3555 :
3556 : /* We insist on collation match for all index types, though */
3557 93868 : if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
3558 6 : return false;
3559 :
3560 93862 : return match_index_to_operand((Node *) em->em_expr, indexcol, index);
3561 : }
3562 :
3563 : /*
3564 : * relation_has_unique_index_for
3565 : * Determine whether the relation provably has at most one row satisfying
3566 : * a set of equality conditions, because the conditions constrain all
3567 : * columns of some unique index.
3568 : *
3569 : * The conditions can be represented in either or both of two ways:
3570 : * 1. A list of RestrictInfo nodes, where the caller has already determined
3571 : * that each condition is a mergejoinable equality with an expression in
3572 : * this relation on one side, and an expression not involving this relation
3573 : * on the other. The transient outer_is_left flag is used to identify which
3574 : * side we should look at: left side if outer_is_left is false, right side
3575 : * if it is true.
3576 : * 2. A list of expressions in this relation, and a corresponding list of
3577 : * equality operators. The caller must have already checked that the operators
3578 : * represent equality. (Note: the operators could be cross-type; the
3579 : * expressions should correspond to their RHS inputs.)
3580 : *
3581 : * The caller need only supply equality conditions arising from joins;
3582 : * this routine automatically adds in any usable baserestrictinfo clauses.
3583 : * (Note that the passed-in restrictlist will be destructively modified!)
3584 : */
3585 : bool
3586 113228 : relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
3587 : List *restrictlist,
3588 : List *exprlist, List *oprlist)
3589 : {
3590 : ListCell *ic;
3591 :
3592 : Assert(list_length(exprlist) == list_length(oprlist));
3593 :
3594 : /* Short-circuit if no indexes... */
3595 113228 : if (rel->indexlist == NIL)
3596 164 : return false;
3597 :
3598 : /*
3599 : * Examine the rel's restriction clauses for usable var = const clauses
3600 : * that we can add to the restrictlist.
3601 : */
3602 215120 : foreach(ic, rel->baserestrictinfo)
3603 : {
3604 102056 : RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
3605 :
3606 : /*
3607 : * Note: can_join won't be set for a restriction clause, but
3608 : * mergeopfamilies will be if it has a mergejoinable operator and
3609 : * doesn't contain volatile functions.
3610 : */
3611 102056 : if (restrictinfo->mergeopfamilies == NIL)
3612 39206 : continue; /* not mergejoinable */
3613 :
3614 : /*
3615 : * The clause certainly doesn't refer to anything but the given rel.
3616 : * If either side is pseudoconstant then we can use it.
3617 : */
3618 62850 : if (bms_is_empty(restrictinfo->left_relids))
3619 : {
3620 : /* righthand side is inner */
3621 1226 : restrictinfo->outer_is_left = true;
3622 : }
3623 61624 : else if (bms_is_empty(restrictinfo->right_relids))
3624 : {
3625 : /* lefthand side is inner */
3626 61604 : restrictinfo->outer_is_left = false;
3627 : }
3628 : else
3629 20 : continue;
3630 :
3631 : /* OK, add to list */
3632 62830 : restrictlist = lappend(restrictlist, restrictinfo);
3633 : }
3634 :
3635 : /* Short-circuit the easy case */
3636 113064 : if (restrictlist == NIL && exprlist == NIL)
3637 148 : return false;
3638 :
3639 : /* Examine each index of the relation ... */
3640 295892 : foreach(ic, rel->indexlist)
3641 : {
3642 250084 : IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
3643 : int c;
3644 :
3645 : /*
3646 : * If the index is not unique, or not immediately enforced, or if it's
3647 : * a partial index that doesn't match the query, it's useless here.
3648 : */
3649 422052 : if (!ind->unique || !ind->immediate ||
3650 171968 : (ind->indpred != NIL && !ind->predOK))
3651 78116 : continue;
3652 :
3653 : /*
3654 : * Try to find each index column in the lists of conditions. This is
3655 : * O(N^2) or worse, but we expect all the lists to be short.
3656 : */
3657 301606 : for (c = 0; c < ind->nkeycolumns; c++)
3658 : {
3659 234498 : bool matched = false;
3660 : ListCell *lc;
3661 : ListCell *lc2;
3662 :
3663 463434 : foreach(lc, restrictlist)
3664 : {
3665 358574 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3666 : Node *rexpr;
3667 :
3668 : /*
3669 : * The condition's equality operator must be a member of the
3670 : * index opfamily, else it is not asserting the right kind of
3671 : * equality behavior for this index. We check this first
3672 : * since it's probably cheaper than match_index_to_operand().
3673 : */
3674 358574 : if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
3675 92276 : continue;
3676 :
3677 : /*
3678 : * XXX at some point we may need to check collations here too.
3679 : * For the moment we assume all collations reduce to the same
3680 : * notion of equality.
3681 : */
3682 :
3683 : /* OK, see if the condition operand matches the index key */
3684 266298 : if (rinfo->outer_is_left)
3685 128340 : rexpr = get_rightop(rinfo->clause);
3686 : else
3687 137958 : rexpr = get_leftop(rinfo->clause);
3688 :
3689 266298 : if (match_index_to_operand(rexpr, c, ind))
3690 : {
3691 129638 : matched = true; /* column is unique */
3692 129638 : break;
3693 : }
3694 : }
3695 :
3696 234498 : if (matched)
3697 129638 : continue;
3698 :
3699 104860 : forboth(lc, exprlist, lc2, oprlist)
3700 : {
3701 0 : Node *expr = (Node *) lfirst(lc);
3702 0 : Oid opr = lfirst_oid(lc2);
3703 :
3704 : /* See if the expression matches the index key */
3705 0 : if (!match_index_to_operand(expr, c, ind))
3706 0 : continue;
3707 :
3708 : /*
3709 : * The equality operator must be a member of the index
3710 : * opfamily, else it is not asserting the right kind of
3711 : * equality behavior for this index. We assume the caller
3712 : * determined it is an equality operator, so we don't need to
3713 : * check any more tightly than this.
3714 : */
3715 0 : if (!op_in_opfamily(opr, ind->opfamily[c]))
3716 0 : continue;
3717 :
3718 : /*
3719 : * XXX at some point we may need to check collations here too.
3720 : * For the moment we assume all collations reduce to the same
3721 : * notion of equality.
3722 : */
3723 :
3724 0 : matched = true; /* column is unique */
3725 0 : break;
3726 : }
3727 :
3728 104860 : if (!matched)
3729 104860 : break; /* no match; this index doesn't help us */
3730 : }
3731 :
3732 : /* Matched all key columns of this index? */
3733 171968 : if (c == ind->nkeycolumns)
3734 67108 : return true;
3735 : }
3736 :
3737 45808 : return false;
3738 : }
3739 :
3740 : /*
3741 : * indexcol_is_bool_constant_for_query
3742 : *
3743 : * If an index column is constrained to have a constant value by the query's
3744 : * WHERE conditions, then it's irrelevant for sort-order considerations.
3745 : * Usually that means we have a restriction clause WHERE indexcol = constant,
3746 : * which gets turned into an EquivalenceClass containing a constant, which
3747 : * is recognized as redundant by build_index_pathkeys(). But if the index
3748 : * column is a boolean variable (or expression), then we are not going to
3749 : * see WHERE indexcol = constant, because expression preprocessing will have
3750 : * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
3751 : * going to have a matching EquivalenceClass (unless the query also contains
3752 : * "ORDER BY indexcol"). To allow such cases to work the same as they would
3753 : * for non-boolean values, this function is provided to detect whether the
3754 : * specified index column matches a boolean restriction clause.
3755 : */
3756 : bool
3757 255760 : indexcol_is_bool_constant_for_query(IndexOptInfo *index, int indexcol)
3758 : {
3759 : ListCell *lc;
3760 :
3761 : /* If the index isn't boolean, we can't possibly get a match */
3762 255760 : if (!IsBooleanOpfamily(index->opfamily[indexcol]))
3763 255544 : return false;
3764 :
3765 : /* Check each restriction clause for the index's rel */
3766 240 : foreach(lc, index->rel->baserestrictinfo)
3767 : {
3768 96 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3769 :
3770 : /*
3771 : * As in match_clause_to_indexcol, never match pseudoconstants to
3772 : * indexes. (It might be semantically okay to do so here, but the
3773 : * odds of getting a match are negligible, so don't waste the cycles.)
3774 : */
3775 96 : if (rinfo->pseudoconstant)
3776 0 : continue;
3777 :
3778 : /* See if we can match the clause's expression to the index column */
3779 96 : if (match_boolean_index_clause(rinfo, indexcol, index))
3780 72 : return true;
3781 : }
3782 :
3783 144 : return false;
3784 : }
3785 :
3786 :
3787 : /****************************************************************************
3788 : * ---- ROUTINES TO CHECK OPERANDS ----
3789 : ****************************************************************************/
3790 :
3791 : /*
3792 : * match_index_to_operand()
3793 : * Generalized test for a match between an index's key
3794 : * and the operand on one side of a restriction or join clause.
3795 : *
3796 : * operand: the nodetree to be compared to the index
3797 : * indexcol: the column number of the index (counting from 0)
3798 : * index: the index of interest
3799 : *
3800 : * Note that we aren't interested in collations here; the caller must check
3801 : * for a collation match, if it's dealing with an operator where that matters.
3802 : *
3803 : * This is exported for use in selfuncs.c.
3804 : */
3805 : bool
3806 1733808 : match_index_to_operand(Node *operand,
3807 : int indexcol,
3808 : IndexOptInfo *index)
3809 : {
3810 : int indkey;
3811 :
3812 : /*
3813 : * Ignore any RelabelType node above the operand. This is needed to be
3814 : * able to apply indexscanning in binary-compatible-operator cases. Note:
3815 : * we can assume there is at most one RelabelType node;
3816 : * eval_const_expressions() will have simplified if more than one.
3817 : */
3818 1733808 : if (operand && IsA(operand, RelabelType))
3819 13742 : operand = (Node *) ((RelabelType *) operand)->arg;
3820 :
3821 1733808 : indkey = index->indexkeys[indexcol];
3822 1733808 : if (indkey != 0)
3823 : {
3824 : /*
3825 : * Simple index column; operand must be a matching Var.
3826 : */
3827 3083496 : if (operand && IsA(operand, Var) &&
3828 2604610 : index->rel->relid == ((Var *) operand)->varno &&
3829 1251852 : indkey == ((Var *) operand)->varattno)
3830 443524 : return true;
3831 : }
3832 : else
3833 : {
3834 : /*
3835 : * Index expression; find the correct expression. (This search could
3836 : * be avoided, at the cost of complicating all the callers of this
3837 : * routine; doesn't seem worth it.)
3838 : */
3839 : ListCell *indexpr_item;
3840 : int i;
3841 : Node *indexkey;
3842 :
3843 3070 : indexpr_item = list_head(index->indexprs);
3844 3070 : for (i = 0; i < indexcol; i++)
3845 : {
3846 0 : if (index->indexkeys[i] == 0)
3847 : {
3848 0 : if (indexpr_item == NULL)
3849 0 : elog(ERROR, "wrong number of index expressions");
3850 0 : indexpr_item = lnext(index->indexprs, indexpr_item);
3851 : }
3852 : }
3853 3070 : if (indexpr_item == NULL)
3854 0 : elog(ERROR, "wrong number of index expressions");
3855 3070 : indexkey = (Node *) lfirst(indexpr_item);
3856 :
3857 : /*
3858 : * Does it match the operand? Again, strip any relabeling.
3859 : */
3860 3070 : if (indexkey && IsA(indexkey, RelabelType))
3861 10 : indexkey = (Node *) ((RelabelType *) indexkey)->arg;
3862 :
3863 3070 : if (equal(indexkey, operand))
3864 1298 : return true;
3865 : }
3866 :
3867 1288986 : return false;
3868 : }
3869 :
3870 : /*
3871 : * is_pseudo_constant_for_index()
3872 : * Test whether the given expression can be used as an indexscan
3873 : * comparison value.
3874 : *
3875 : * An indexscan comparison value must not contain any volatile functions,
3876 : * and it can't contain any Vars of the index's own table. Vars of
3877 : * other tables are okay, though; in that case we'd be producing an
3878 : * indexqual usable in a parameterized indexscan. This is, therefore,
3879 : * a weaker condition than is_pseudo_constant_clause().
3880 : *
3881 : * This function is exported for use by planner support functions,
3882 : * which will have available the IndexOptInfo, but not any RestrictInfo
3883 : * infrastructure. It is making the same test made by functions above
3884 : * such as match_opclause_to_indexcol(), but those rely where possible
3885 : * on RestrictInfo information about variable membership.
3886 : *
3887 : * expr: the nodetree to be checked
3888 : * index: the index of interest
3889 : */
3890 : bool
3891 0 : is_pseudo_constant_for_index(Node *expr, IndexOptInfo *index)
3892 : {
3893 : /* pull_varnos is cheaper than volatility check, so do that first */
3894 0 : if (bms_is_member(index->rel->relid, pull_varnos(expr)))
3895 0 : return false; /* no good, contains Var of table */
3896 0 : if (contain_volatile_functions(expr))
3897 0 : return false; /* no good, volatile comparison value */
3898 0 : return true;
3899 : }
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