Age Owner Branch data TLA 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) 1996-2024, 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 void get_index_paths(PlannerInfo *root, RelOptInfo *rel,
103 : : IndexOptInfo *index, IndexClauseSet *clauses,
104 : : List **bitindexpaths);
105 : : static List *build_index_paths(PlannerInfo *root, RelOptInfo *rel,
106 : : IndexOptInfo *index, IndexClauseSet *clauses,
107 : : bool useful_predicate,
108 : : ScanTypeControl scantype,
109 : : bool *skip_nonnative_saop);
110 : : static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
111 : : List *clauses, List *other_clauses);
112 : : static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
113 : : List *clauses, List *other_clauses);
114 : : static Path *choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel,
115 : : List *paths);
116 : : static int path_usage_comparator(const void *a, const void *b);
117 : : static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel,
118 : : Path *ipath);
119 : : static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel,
120 : : List *paths);
121 : : static PathClauseUsage *classify_index_clause_usage(Path *path,
122 : : List **clauselist);
123 : : static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds);
124 : : static int find_list_position(Node *node, List **nodelist);
125 : : static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index);
126 : : static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids);
127 : : static double adjust_rowcount_for_semijoins(PlannerInfo *root,
128 : : Index cur_relid,
129 : : Index outer_relid,
130 : : double rowcount);
131 : : static double approximate_joinrel_size(PlannerInfo *root, Relids relids);
132 : : static void match_restriction_clauses_to_index(PlannerInfo *root,
133 : : IndexOptInfo *index,
134 : : IndexClauseSet *clauseset);
135 : : static void match_join_clauses_to_index(PlannerInfo *root,
136 : : RelOptInfo *rel, IndexOptInfo *index,
137 : : IndexClauseSet *clauseset,
138 : : List **joinorclauses);
139 : : static void match_eclass_clauses_to_index(PlannerInfo *root,
140 : : IndexOptInfo *index,
141 : : IndexClauseSet *clauseset);
142 : : static void match_clauses_to_index(PlannerInfo *root,
143 : : List *clauses,
144 : : IndexOptInfo *index,
145 : : IndexClauseSet *clauseset);
146 : : static void match_clause_to_index(PlannerInfo *root,
147 : : RestrictInfo *rinfo,
148 : : IndexOptInfo *index,
149 : : IndexClauseSet *clauseset);
150 : : static IndexClause *match_clause_to_indexcol(PlannerInfo *root,
151 : : RestrictInfo *rinfo,
152 : : int indexcol,
153 : : IndexOptInfo *index);
154 : : static bool IsBooleanOpfamily(Oid opfamily);
155 : : static IndexClause *match_boolean_index_clause(PlannerInfo *root,
156 : : RestrictInfo *rinfo,
157 : : int indexcol, IndexOptInfo *index);
158 : : static IndexClause *match_opclause_to_indexcol(PlannerInfo *root,
159 : : RestrictInfo *rinfo,
160 : : int indexcol,
161 : : IndexOptInfo *index);
162 : : static IndexClause *match_funcclause_to_indexcol(PlannerInfo *root,
163 : : RestrictInfo *rinfo,
164 : : int indexcol,
165 : : IndexOptInfo *index);
166 : : static IndexClause *get_index_clause_from_support(PlannerInfo *root,
167 : : RestrictInfo *rinfo,
168 : : Oid funcid,
169 : : int indexarg,
170 : : int indexcol,
171 : : IndexOptInfo *index);
172 : : static IndexClause *match_saopclause_to_indexcol(PlannerInfo *root,
173 : : RestrictInfo *rinfo,
174 : : int indexcol,
175 : : IndexOptInfo *index);
176 : : static IndexClause *match_rowcompare_to_indexcol(PlannerInfo *root,
177 : : RestrictInfo *rinfo,
178 : : int indexcol,
179 : : IndexOptInfo *index);
180 : : static IndexClause *expand_indexqual_rowcompare(PlannerInfo *root,
181 : : RestrictInfo *rinfo,
182 : : int indexcol,
183 : : IndexOptInfo *index,
184 : : Oid expr_op,
185 : : bool var_on_left);
186 : : static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
187 : : List **orderby_clauses_p,
188 : : List **clause_columns_p);
189 : : static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
190 : : int indexcol, Expr *clause, Oid pk_opfamily);
191 : : static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
192 : : EquivalenceClass *ec, EquivalenceMember *em,
193 : : void *arg);
194 : :
195 : :
196 : : /*
197 : : * create_index_paths()
198 : : * Generate all interesting index paths for the given relation.
199 : : * Candidate paths are added to the rel's pathlist (using add_path).
200 : : *
201 : : * To be considered for an index scan, an index must match one or more
202 : : * restriction clauses or join clauses from the query's qual condition,
203 : : * or match the query's ORDER BY condition, or have a predicate that
204 : : * matches the query's qual condition.
205 : : *
206 : : * There are two basic kinds of index scans. A "plain" index scan uses
207 : : * only restriction clauses (possibly none at all) in its indexqual,
208 : : * so it can be applied in any context. A "parameterized" index scan uses
209 : : * join clauses (plus restriction clauses, if available) in its indexqual.
210 : : * When joining such a scan to one of the relations supplying the other
211 : : * variables used in its indexqual, the parameterized scan must appear as
212 : : * the inner relation of a nestloop join; it can't be used on the outer side,
213 : : * nor in a merge or hash join. In that context, values for the other rels'
214 : : * attributes are available and fixed during any one scan of the indexpath.
215 : : *
216 : : * An IndexPath is generated and submitted to add_path() for each plain or
217 : : * parameterized index scan this routine deems potentially interesting for
218 : : * the current query.
219 : : *
220 : : * 'rel' is the relation for which we want to generate index paths
221 : : *
222 : : * Note: check_index_predicates() must have been run previously for this rel.
223 : : *
224 : : * Note: in cases involving LATERAL references in the relation's tlist, it's
225 : : * possible that rel->lateral_relids is nonempty. Currently, we include
226 : : * lateral_relids into the parameterization reported for each path, but don't
227 : : * take it into account otherwise. The fact that any such rels *must* be
228 : : * available as parameter sources perhaps should influence our choices of
229 : : * index quals ... but for now, it doesn't seem worth troubling over.
230 : : * In particular, comments below about "unparameterized" paths should be read
231 : : * as meaning "unparameterized so far as the indexquals are concerned".
232 : : */
233 : : void
6888 tgl@sss.pgh.pa.us 234 :CBC 173241 : create_index_paths(PlannerInfo *root, RelOptInfo *rel)
235 : : {
236 : : List *indexpaths;
237 : : List *bitindexpaths;
238 : : List *bitjoinpaths;
239 : : List *joinorclauses;
240 : : IndexClauseSet rclauseset;
241 : : IndexClauseSet jclauseset;
242 : : IndexClauseSet eclauseset;
243 : : ListCell *lc;
244 : :
245 : : /* Skip the whole mess if no indexes */
6932 246 [ + + ]: 173241 : if (rel->indexlist == NIL)
247 : 33542 : return;
248 : :
249 : : /* Bitmap paths are collected and then dealt with at the end */
4461 250 : 139699 : bitindexpaths = bitjoinpaths = joinorclauses = NIL;
251 : :
252 : : /* Examine each index in turn */
4245 253 [ + - + + : 436849 : foreach(lc, rel->indexlist)
+ + ]
254 : : {
255 : 297150 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
256 : :
257 : : /* Protect limited-size array in IndexClauseSets */
1888 258 [ - + ]: 297150 : Assert(index->nkeycolumns <= INDEX_MAX_KEYS);
259 : :
260 : : /*
261 : : * Ignore partial indexes that do not match the query.
262 : : * (generate_bitmap_or_paths() might be able to do something with
263 : : * them, but that's of no concern here.)
264 : : */
4461 265 [ + + + + ]: 297150 : if (index->indpred != NIL && !index->predOK)
266 : 244 : continue;
267 : :
268 : : /*
269 : : * Identify the restriction clauses that can match the index.
270 : : */
271 [ + - + - : 10094804 : MemSet(&rclauseset, 0, sizeof(rclauseset));
+ - + - +
+ ]
1889 272 : 296906 : match_restriction_clauses_to_index(root, index, &rclauseset);
273 : :
274 : : /*
275 : : * Build index paths from the restriction clauses. These will be
276 : : * non-parameterized paths. Plain paths go directly to add_path(),
277 : : * bitmap paths are added to bitindexpaths to be handled below.
278 : : */
4461 279 : 296906 : get_index_paths(root, rel, index, &rclauseset,
280 : : &bitindexpaths);
281 : :
282 : : /*
283 : : * Identify the join clauses that can match the index. For the moment
284 : : * we keep them separate from the restriction clauses. Note that this
285 : : * step finds only "loose" join clauses that have not been merged into
286 : : * EquivalenceClasses. Also, collect join OR clauses for later.
287 : : */
288 [ + - + - : 10094804 : MemSet(&jclauseset, 0, sizeof(jclauseset));
+ - + - +
+ ]
3893 289 : 296906 : match_join_clauses_to_index(root, rel, index,
290 : : &jclauseset, &joinorclauses);
291 : :
292 : : /*
293 : : * Look for EquivalenceClasses that can generate joinclauses matching
294 : : * the index.
295 : : */
4461 296 [ + - + - : 10094804 : MemSet(&eclauseset, 0, sizeof(eclauseset));
+ - + - +
+ ]
3893 297 : 296906 : match_eclass_clauses_to_index(root, index,
298 : : &eclauseset);
299 : :
300 : : /*
301 : : * If we found any plain or eclass join clauses, build parameterized
302 : : * index paths using them.
303 : : */
4461 304 [ + + + + ]: 296906 : if (jclauseset.nonempty || eclauseset.nonempty)
305 : 53400 : consider_index_join_clauses(root, rel, index,
306 : : &rclauseset,
307 : : &jclauseset,
308 : : &eclauseset,
309 : : &bitjoinpaths);
310 : : }
311 : :
312 : : /*
313 : : * Generate BitmapOrPaths for any suitable OR-clauses present in the
314 : : * restriction list. Add these to bitindexpaths.
315 : : */
316 : 139699 : indexpaths = generate_bitmap_or_paths(root, rel,
317 : : rel->baserestrictinfo, NIL);
318 : 139699 : bitindexpaths = list_concat(bitindexpaths, indexpaths);
319 : :
320 : : /*
321 : : * Likewise, generate BitmapOrPaths for any suitable OR-clauses present in
322 : : * the joinclause list. Add these to bitjoinpaths.
323 : : */
324 : 139699 : indexpaths = generate_bitmap_or_paths(root, rel,
325 : : joinorclauses, rel->baserestrictinfo);
326 : 139699 : bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
327 : :
328 : : /*
329 : : * If we found anything usable, generate a BitmapHeapPath for the most
330 : : * promising combination of restriction bitmap index paths. Note there
331 : : * will be only one such path no matter how many indexes exist. This
332 : : * should be sufficient since there's basically only one figure of merit
333 : : * (total cost) for such a path.
334 : : */
335 [ + + ]: 139699 : if (bitindexpaths != NIL)
336 : : {
337 : : Path *bitmapqual;
338 : : BitmapHeapPath *bpath;
339 : :
340 : 87676 : bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
4249 341 : 87676 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
342 : : rel->lateral_relids, 1.0, 0);
4461 343 : 87676 : add_path(rel, (Path *) bpath);
344 : :
345 : : /* create a partial bitmap heap path */
2594 rhaas@postgresql.org 346 [ + + + + ]: 87676 : if (rel->consider_parallel && rel->lateral_relids == NULL)
347 : 63083 : create_partial_bitmap_paths(root, rel, bitmapqual);
348 : : }
349 : :
350 : : /*
351 : : * Likewise, if we found anything usable, generate BitmapHeapPaths for the
352 : : * most promising combinations of join bitmap index paths. Our strategy
353 : : * is to generate one such path for each distinct parameterization seen
354 : : * among the available bitmap index paths. This may look pretty
355 : : * expensive, but usually there won't be very many distinct
356 : : * parameterizations. (This logic is quite similar to that in
357 : : * consider_index_join_clauses, but we're working with whole paths not
358 : : * individual clauses.)
359 : : */
4461 tgl@sss.pgh.pa.us 360 [ + + ]: 139699 : if (bitjoinpaths != NIL)
361 : : {
362 : : List *all_path_outers;
363 : :
364 : : /* Identify each distinct parameterization seen in bitjoinpaths */
1370 365 : 49077 : all_path_outers = NIL;
4259 366 [ + - + + : 107398 : foreach(lc, bitjoinpaths)
+ + ]
367 : : {
368 : 58321 : Path *path = (Path *) lfirst(lc);
1370 369 [ + + ]: 58321 : Relids required_outer = PATH_REQ_OUTER(path);
370 : :
518 371 : 58321 : all_path_outers = list_append_unique(all_path_outers,
372 : : required_outer);
373 : : }
374 : :
375 : : /* Now, for each distinct parameterization set ... */
4259 376 [ + - + + : 104795 : foreach(lc, all_path_outers)
+ + ]
377 : : {
378 : 55718 : Relids max_outers = (Relids) lfirst(lc);
379 : : List *this_path_set;
380 : : Path *bitmapqual;
381 : : Relids required_outer;
382 : : double loop_count;
383 : : BitmapHeapPath *bpath;
384 : : ListCell *lcp;
385 : :
386 : : /* Identify all the bitmap join paths needing no more than that */
387 : 55718 : this_path_set = NIL;
1370 388 [ + - + + : 132068 : foreach(lcp, bitjoinpaths)
+ + ]
389 : : {
4259 390 : 76350 : Path *path = (Path *) lfirst(lcp);
391 : :
1370 392 [ + + + + ]: 76350 : if (bms_is_subset(PATH_REQ_OUTER(path), max_outers))
4259 393 : 61437 : this_path_set = lappend(this_path_set, path);
394 : : }
395 : :
396 : : /*
397 : : * Add in restriction bitmap paths, since they can be used
398 : : * together with any join paths.
399 : : */
400 : 55718 : this_path_set = list_concat(this_path_set, bitindexpaths);
401 : :
402 : : /* Select best AND combination for this parameterization */
403 : 55718 : bitmapqual = choose_bitmap_and(root, rel, this_path_set);
404 : :
405 : : /* And push that path into the mix */
1370 406 [ + + ]: 55718 : required_outer = PATH_REQ_OUTER(bitmapqual);
3322 407 : 55718 : loop_count = get_loop_count(root, rel->relid, required_outer);
4259 408 : 55718 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
409 : : required_outer, loop_count, 0);
410 : 55718 : add_path(rel, (Path *) bpath);
411 : : }
412 : : }
413 : : }
414 : :
415 : : /*
416 : : * consider_index_join_clauses
417 : : * Given sets of join clauses for an index, decide which parameterized
418 : : * index paths to build.
419 : : *
420 : : * Plain indexpaths are sent directly to add_path, while potential
421 : : * bitmap indexpaths are added to *bitindexpaths for later processing.
422 : : *
423 : : * 'rel' is the index's heap relation
424 : : * 'index' is the index for which we want to generate paths
425 : : * 'rclauseset' is the collection of indexable restriction clauses
426 : : * 'jclauseset' is the collection of indexable simple join clauses
427 : : * 'eclauseset' is the collection of indexable clauses from EquivalenceClasses
428 : : * '*bitindexpaths' is the list to add bitmap paths to
429 : : */
430 : : static void
4461 431 : 53400 : consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
432 : : IndexOptInfo *index,
433 : : IndexClauseSet *rclauseset,
434 : : IndexClauseSet *jclauseset,
435 : : IndexClauseSet *eclauseset,
436 : : List **bitindexpaths)
437 : : {
4182 438 : 53400 : int considered_clauses = 0;
4228 439 : 53400 : List *considered_relids = NIL;
440 : : int indexcol;
441 : :
442 : : /*
443 : : * The strategy here is to identify every potentially useful set of outer
444 : : * rels that can provide indexable join clauses. For each such set,
445 : : * select all the join clauses available from those outer rels, add on all
446 : : * the indexable restriction clauses, and generate plain and/or bitmap
447 : : * index paths for that set of clauses. This is based on the assumption
448 : : * that it's always better to apply a clause as an indexqual than as a
449 : : * filter (qpqual); which is where an available clause would end up being
450 : : * applied if we omit it from the indexquals.
451 : : *
452 : : * This looks expensive, but in most practical cases there won't be very
453 : : * many distinct sets of outer rels to consider. As a safety valve when
454 : : * that's not true, we use a heuristic: limit the number of outer rel sets
455 : : * considered to a multiple of the number of clauses considered. (We'll
456 : : * always consider using each individual join clause, though.)
457 : : *
458 : : * For simplicity in selecting relevant clauses, we represent each set of
459 : : * outer rels as a maximum set of clause_relids --- that is, the indexed
460 : : * relation itself is also included in the relids set. considered_relids
461 : : * lists all relids sets we've already tried.
462 : : */
1888 463 [ + + ]: 130018 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
464 : : {
465 : : /* Consider each applicable simple join clause */
4182 466 : 76618 : considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
4228 467 : 76618 : consider_index_join_outer_rels(root, rel, index,
468 : : rclauseset, jclauseset, eclauseset,
469 : : bitindexpaths,
470 : : jclauseset->indexclauses[indexcol],
471 : : considered_clauses,
472 : : &considered_relids);
473 : : /* Consider each applicable eclass join clause */
4182 474 : 76618 : considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
4228 475 : 76618 : consider_index_join_outer_rels(root, rel, index,
476 : : rclauseset, jclauseset, eclauseset,
477 : : bitindexpaths,
478 : : eclauseset->indexclauses[indexcol],
479 : : considered_clauses,
480 : : &considered_relids);
481 : : }
482 : 53400 : }
483 : :
484 : : /*
485 : : * consider_index_join_outer_rels
486 : : * Generate parameterized paths based on clause relids in the clause list.
487 : : *
488 : : * Workhorse for consider_index_join_clauses; see notes therein for rationale.
489 : : *
490 : : * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset', and
491 : : * 'bitindexpaths' as above
492 : : * 'indexjoinclauses' is a list of IndexClauses for join clauses
493 : : * 'considered_clauses' is the total number of clauses considered (so far)
494 : : * '*considered_relids' is a list of all relids sets already considered
495 : : */
496 : : static void
497 : 153236 : consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
498 : : IndexOptInfo *index,
499 : : IndexClauseSet *rclauseset,
500 : : IndexClauseSet *jclauseset,
501 : : IndexClauseSet *eclauseset,
502 : : List **bitindexpaths,
503 : : List *indexjoinclauses,
504 : : int considered_clauses,
505 : : List **considered_relids)
506 : : {
507 : : ListCell *lc;
508 : :
509 : : /* Examine relids of each joinclause in the given list */
510 [ + + + + : 210647 : foreach(lc, indexjoinclauses)
+ + ]
511 : : {
1891 512 : 57411 : IndexClause *iclause = (IndexClause *) lfirst(lc);
513 : 57411 : Relids clause_relids = iclause->rinfo->clause_relids;
514 : 57411 : EquivalenceClass *parent_ec = iclause->rinfo->parent_ec;
515 : : int num_considered_relids;
516 : :
517 : : /* If we already tried its relids set, no need to do so again */
518 518 [ + + ]: 57411 : if (list_member(*considered_relids, clause_relids))
4228 519 : 720 : continue;
520 : :
521 : : /*
522 : : * Generate the union of this clause's relids set with each
523 : : * previously-tried set. This ensures we try this clause along with
524 : : * every interesting subset of previous clauses. However, to avoid
525 : : * exponential growth of planning time when there are many clauses,
526 : : * limit the number of relid sets accepted to 10 * considered_clauses.
527 : : *
528 : : * Note: get_join_index_paths appends entries to *considered_relids,
529 : : * but we do not need to visit such newly-added entries within this
530 : : * loop, so we don't use foreach() here. No real harm would be done
531 : : * if we did visit them, since the subset check would reject them; but
532 : : * it would waste some cycles.
533 : : */
1735 534 : 56691 : num_considered_relids = list_length(*considered_relids);
535 [ + + ]: 60102 : for (int pos = 0; pos < num_considered_relids; pos++)
536 : : {
537 : 3411 : Relids oldrelids = (Relids) list_nth(*considered_relids, pos);
538 : :
539 : : /*
540 : : * If either is a subset of the other, no new set is possible.
541 : : * This isn't a complete test for redundancy, but it's easy and
542 : : * cheap. get_join_index_paths will check more carefully if we
543 : : * already generated the same relids set.
544 : : */
4228 545 [ + + ]: 3411 : if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
546 : 12 : continue;
547 : :
548 : : /*
549 : : * If this clause was derived from an equivalence class, the
550 : : * clause list may contain other clauses derived from the same
551 : : * eclass. We should not consider that combining this clause with
552 : : * one of those clauses generates a usefully different
553 : : * parameterization; so skip if any clause derived from the same
554 : : * eclass would already have been included when using oldrelids.
555 : : */
1891 556 [ + + + + ]: 6722 : if (parent_ec &&
557 : 3323 : eclass_already_used(parent_ec, oldrelids,
558 : : indexjoinclauses))
4182 559 : 1919 : continue;
560 : :
561 : : /*
562 : : * If the number of relid sets considered exceeds our heuristic
563 : : * limit, stop considering combinations of clauses. We'll still
564 : : * consider the current clause alone, though (below this loop).
565 : : */
566 [ - + ]: 1480 : if (list_length(*considered_relids) >= 10 * considered_clauses)
4182 tgl@sss.pgh.pa.us 567 :UBC 0 : break;
568 : :
569 : : /* OK, try the union set */
4228 tgl@sss.pgh.pa.us 570 :CBC 1480 : get_join_index_paths(root, rel, index,
571 : : rclauseset, jclauseset, eclauseset,
572 : : bitindexpaths,
573 : : bms_union(clause_relids, oldrelids),
574 : : considered_relids);
575 : : }
576 : :
577 : : /* Also try this set of relids by itself */
578 : 56691 : get_join_index_paths(root, rel, index,
579 : : rclauseset, jclauseset, eclauseset,
580 : : bitindexpaths,
581 : : clause_relids,
582 : : considered_relids);
583 : : }
4461 584 : 153236 : }
585 : :
586 : : /*
587 : : * get_join_index_paths
588 : : * Generate index paths using clauses from the specified outer relations.
589 : : * In addition to generating paths, relids is added to *considered_relids
590 : : * if not already present.
591 : : *
592 : : * Workhorse for consider_index_join_clauses; see notes therein for rationale.
593 : : *
594 : : * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset',
595 : : * 'bitindexpaths', 'considered_relids' as above
596 : : * 'relids' is the current set of relids to consider (the target rel plus
597 : : * one or more outer rels)
598 : : */
599 : : static void
4228 600 : 58171 : get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
601 : : IndexOptInfo *index,
602 : : IndexClauseSet *rclauseset,
603 : : IndexClauseSet *jclauseset,
604 : : IndexClauseSet *eclauseset,
605 : : List **bitindexpaths,
606 : : Relids relids,
607 : : List **considered_relids)
608 : : {
609 : : IndexClauseSet clauseset;
610 : : int indexcol;
611 : :
612 : : /* If we already considered this relids set, don't repeat the work */
518 613 [ - + ]: 58171 : if (list_member(*considered_relids, relids))
4461 tgl@sss.pgh.pa.us 614 :UBC 0 : return;
615 : :
616 : : /* Identify indexclauses usable with this relids set */
4228 tgl@sss.pgh.pa.us 617 [ + - + - :CBC 1977814 : MemSet(&clauseset, 0, sizeof(clauseset));
+ - + - +
+ ]
618 : :
1888 619 [ + + ]: 143686 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
620 : : {
621 : : ListCell *lc;
622 : :
623 : : /* First find applicable simple join clauses */
4228 624 [ + + + + : 102345 : foreach(lc, jclauseset->indexclauses[indexcol])
+ + ]
625 : : {
1891 626 : 16830 : IndexClause *iclause = (IndexClause *) lfirst(lc);
627 : :
628 [ + + ]: 16830 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
4228 629 : 16640 : clauseset.indexclauses[indexcol] =
1891 630 : 16640 : lappend(clauseset.indexclauses[indexcol], iclause);
631 : : }
632 : :
633 : : /*
634 : : * Add applicable eclass join clauses. The clauses generated for each
635 : : * column are redundant (cf generate_implied_equalities_for_column),
636 : : * so we need at most one. This is the only exception to the general
637 : : * rule of using all available index clauses.
638 : : */
4228 639 [ + + + + : 90504 : foreach(lc, eclauseset->indexclauses[indexcol])
+ + ]
640 : : {
1891 641 : 48702 : IndexClause *iclause = (IndexClause *) lfirst(lc);
642 : :
643 [ + + ]: 48702 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
644 : : {
4228 645 : 43713 : clauseset.indexclauses[indexcol] =
1891 646 : 43713 : lappend(clauseset.indexclauses[indexcol], iclause);
4228 647 : 43713 : break;
648 : : }
649 : : }
650 : :
651 : : /* Add restriction clauses */
652 : 85515 : clauseset.indexclauses[indexcol] =
653 : 85515 : list_concat(clauseset.indexclauses[indexcol],
654 : 85515 : rclauseset->indexclauses[indexcol]);
655 : :
656 [ + + ]: 85515 : if (clauseset.indexclauses[indexcol] != NIL)
657 : 70292 : clauseset.nonempty = true;
658 : : }
659 : :
660 : : /* We should have found something, else caller passed silly relids */
661 [ - + ]: 58171 : Assert(clauseset.nonempty);
662 : :
663 : : /* Build index path(s) using the collected set of clauses */
664 : 58171 : get_index_paths(root, rel, index, &clauseset, bitindexpaths);
665 : :
666 : : /*
667 : : * Remember we considered paths for this set of relids.
668 : : */
1735 669 : 58171 : *considered_relids = lappend(*considered_relids, relids);
670 : : }
671 : :
672 : : /*
673 : : * eclass_already_used
674 : : * True if any join clause usable with oldrelids was generated from
675 : : * the specified equivalence class.
676 : : */
677 : : static bool
4182 678 : 3323 : eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
679 : : List *indexjoinclauses)
680 : : {
681 : : ListCell *lc;
682 : :
683 [ + - + + : 4874 : foreach(lc, indexjoinclauses)
+ + ]
684 : : {
1891 685 : 3470 : IndexClause *iclause = (IndexClause *) lfirst(lc);
686 : 3470 : RestrictInfo *rinfo = iclause->rinfo;
687 : :
4182 688 [ + - + + ]: 6940 : if (rinfo->parent_ec == parent_ec &&
689 : 3470 : bms_is_subset(rinfo->clause_relids, oldrelids))
690 : 1919 : return true;
691 : : }
692 : 1404 : return false;
693 : : }
694 : :
695 : :
696 : : /*
697 : : * get_index_paths
698 : : * Given an index and a set of index clauses for it, construct IndexPaths.
699 : : *
700 : : * Plain indexpaths are sent directly to add_path, while potential
701 : : * bitmap indexpaths are added to *bitindexpaths for later processing.
702 : : *
703 : : * This is a fairly simple frontend to build_index_paths(). Its reason for
704 : : * existence is mainly to handle ScalarArrayOpExpr quals properly. If the
705 : : * index AM supports them natively, we should just include them in simple
706 : : * index paths. If not, we should exclude them while building simple index
707 : : * paths, and then make a separate attempt to include them in bitmap paths.
708 : : */
709 : : static void
4461 710 : 355077 : get_index_paths(PlannerInfo *root, RelOptInfo *rel,
711 : : IndexOptInfo *index, IndexClauseSet *clauses,
712 : : List **bitindexpaths)
713 : : {
714 : : List *indexpaths;
3458 715 : 355077 : bool skip_nonnative_saop = false;
716 : : ListCell *lc;
717 : :
718 : : /*
719 : : * Build simple index paths using the clauses. Allow ScalarArrayOpExpr
720 : : * clauses only if the index AM supports them natively.
721 : : */
4461 722 : 355077 : indexpaths = build_index_paths(root, rel,
723 : : index, clauses,
724 : 355077 : index->predOK,
725 : : ST_ANYSCAN,
726 : : &skip_nonnative_saop);
727 : :
728 : : /*
729 : : * Submit all the ones that can form plain IndexScan plans to add_path. (A
730 : : * plain IndexPath can represent either a plain IndexScan or an
731 : : * IndexOnlyScan, but for our purposes here that distinction does not
732 : : * matter. However, some of the indexes might support only bitmap scans,
733 : : * and those we mustn't submit to add_path here.)
734 : : *
735 : : * Also, pick out the ones that are usable as bitmap scans. For that, we
736 : : * must discard indexes that don't support bitmap scans, and we also are
737 : : * only interested in paths that have some selectivity; we should discard
738 : : * anything that was generated solely for ordering purposes.
739 : : */
740 [ + + + + : 565197 : foreach(lc, indexpaths)
+ + ]
741 : : {
742 : 210120 : IndexPath *ipath = (IndexPath *) lfirst(lc);
743 : :
744 [ + + ]: 210120 : if (index->amhasgettuple)
5519 745 : 203420 : add_path(rel, (Path *) ipath);
746 : :
4461 747 [ + - ]: 210120 : if (index->amhasgetbitmap &&
4842 748 [ + + ]: 210120 : (ipath->path.pathkeys == NIL ||
749 [ + + ]: 125691 : ipath->indexselectivity < 1.0))
4461 750 : 154751 : *bitindexpaths = lappend(*bitindexpaths, ipath);
751 : : }
752 : :
753 : : /*
754 : : * If there were ScalarArrayOpExpr clauses that the index can't handle
755 : : * natively, generate bitmap scan paths relying on executor-managed
756 : : * ScalarArrayOpExpr.
757 : : */
3458 758 [ + + ]: 355077 : if (skip_nonnative_saop)
759 : : {
4461 760 : 16 : indexpaths = build_index_paths(root, rel,
761 : : index, clauses,
762 : : false,
763 : : ST_BITMAPSCAN,
764 : : NULL);
765 : 16 : *bitindexpaths = list_concat(*bitindexpaths, indexpaths);
766 : : }
767 : 355077 : }
768 : :
769 : : /*
770 : : * build_index_paths
771 : : * Given an index and a set of index clauses for it, construct zero
772 : : * or more IndexPaths. It also constructs zero or more partial IndexPaths.
773 : : *
774 : : * We return a list of paths because (1) this routine checks some cases
775 : : * that should cause us to not generate any IndexPath, and (2) in some
776 : : * cases we want to consider both a forward and a backward scan, so as
777 : : * to obtain both sort orders. Note that the paths are just returned
778 : : * to the caller and not immediately fed to add_path().
779 : : *
780 : : * At top level, useful_predicate should be exactly the index's predOK flag
781 : : * (ie, true if it has a predicate that was proven from the restriction
782 : : * clauses). When working on an arm of an OR clause, useful_predicate
783 : : * should be true if the predicate required the current OR list to be proven.
784 : : * Note that this routine should never be called at all if the index has an
785 : : * unprovable predicate.
786 : : *
787 : : * scantype indicates whether we want to create plain indexscans, bitmap
788 : : * indexscans, or both. When it's ST_BITMAPSCAN, we will not consider
789 : : * index ordering while deciding if a Path is worth generating.
790 : : *
791 : : * If skip_nonnative_saop is non-NULL, we ignore ScalarArrayOpExpr clauses
792 : : * unless the index AM supports them directly, and we set *skip_nonnative_saop
793 : : * to true if we found any such clauses (caller must initialize the variable
794 : : * to false). If it's NULL, we do not ignore ScalarArrayOpExpr clauses.
795 : : *
796 : : * 'rel' is the index's heap relation
797 : : * 'index' is the index for which we want to generate paths
798 : : * 'clauses' is the collection of indexable clauses (IndexClause nodes)
799 : : * 'useful_predicate' indicates whether the index has a useful predicate
800 : : * 'scantype' indicates whether we need plain or bitmap scan support
801 : : * 'skip_nonnative_saop' indicates whether to accept SAOP if index AM doesn't
802 : : */
803 : : static List *
804 : 356432 : build_index_paths(PlannerInfo *root, RelOptInfo *rel,
805 : : IndexOptInfo *index, IndexClauseSet *clauses,
806 : : bool useful_predicate,
807 : : ScanTypeControl scantype,
808 : : bool *skip_nonnative_saop)
809 : : {
810 : 356432 : List *result = NIL;
811 : : IndexPath *ipath;
812 : : List *index_clauses;
813 : : Relids outer_relids;
814 : : double loop_count;
815 : : List *orderbyclauses;
816 : : List *orderbyclausecols;
817 : : List *index_pathkeys;
818 : : List *useful_pathkeys;
819 : : bool pathkeys_possibly_useful;
820 : : bool index_is_ordered;
821 : : bool index_only_scan;
822 : : int indexcol;
823 : :
8 pg@bowt.ie 824 [ + + - + ]:GNC 356432 : Assert(skip_nonnative_saop != NULL || scantype == ST_BITMAPSCAN);
825 : :
826 : : /*
827 : : * Check that index supports the desired scan type(s)
828 : : */
4461 tgl@sss.pgh.pa.us 829 [ - + + - ]:CBC 356432 : switch (scantype)
830 : : {
4461 tgl@sss.pgh.pa.us 831 :UBC 0 : case ST_INDEXSCAN:
832 [ # # ]: 0 : if (!index->amhasgettuple)
833 : 0 : return NIL;
834 : 0 : break;
4461 tgl@sss.pgh.pa.us 835 :CBC 1355 : case ST_BITMAPSCAN:
836 [ - + ]: 1355 : if (!index->amhasgetbitmap)
4461 tgl@sss.pgh.pa.us 837 :UBC 0 : return NIL;
4461 tgl@sss.pgh.pa.us 838 :CBC 1355 : break;
839 : 355077 : case ST_ANYSCAN:
840 : : /* either or both are OK */
841 : 355077 : break;
842 : : }
843 : :
844 : : /*
845 : : * 1. Combine the per-column IndexClause lists into an overall list.
846 : : *
847 : : * In the resulting list, clauses are ordered by index key, so that the
848 : : * column numbers form a nondecreasing sequence. (This order is depended
849 : : * on by btree and possibly other places.) The list can be empty, if the
850 : : * index AM allows that.
851 : : *
852 : : * We also build a Relids set showing which outer rels are required by the
853 : : * selected clauses. Any lateral_relids are included in that, but not
854 : : * otherwise accounted for.
855 : : */
856 : 356432 : index_clauses = NIL;
4249 857 : 356432 : outer_relids = bms_copy(rel->lateral_relids);
1888 858 [ + + ]: 1020925 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
859 : : {
860 : : ListCell *lc;
861 : :
4461 862 [ + + + + : 842864 : foreach(lc, clauses->indexclauses[indexcol])
+ + ]
863 : : {
1891 864 : 178224 : IndexClause *iclause = (IndexClause *) lfirst(lc);
865 : 178224 : RestrictInfo *rinfo = iclause->rinfo;
866 : :
8 pg@bowt.ie 867 [ + + + + ]:GNC 178224 : if (skip_nonnative_saop && !index->amsearcharray &&
868 [ + + ]: 10427 : IsA(rinfo->clause, ScalarArrayOpExpr))
869 : : {
870 : : /*
871 : : * Caller asked us to generate IndexPaths that omit any
872 : : * ScalarArrayOpExpr clauses when the underlying index AM
873 : : * lacks native support.
874 : : *
875 : : * We must omit this clause (and tell caller about it).
876 : : */
877 : 16 : *skip_nonnative_saop = true;
878 : 16 : continue;
879 : : }
880 : :
881 : : /* OK to include this clause */
1891 tgl@sss.pgh.pa.us 882 :CBC 178208 : index_clauses = lappend(index_clauses, iclause);
4461 883 : 178208 : outer_relids = bms_add_members(outer_relids,
884 : 178208 : rinfo->clause_relids);
885 : : }
886 : :
887 : : /*
888 : : * If no clauses match the first index column, check for amoptionalkey
889 : : * restriction. We can't generate a scan over an index with
890 : : * amoptionalkey = false unless there's at least one index clause.
891 : : * (When working on columns after the first, this test cannot fail. It
892 : : * is always okay for columns after the first to not have any
893 : : * clauses.)
894 : : */
895 [ + + + + ]: 664640 : if (index_clauses == NIL && !index->amoptionalkey)
896 : 147 : return NIL;
897 : : }
898 : :
899 : : /* We do not want the index's rel itself listed in outer_relids */
900 : 356285 : outer_relids = bms_del_member(outer_relids, rel->relid);
901 : :
902 : : /* Compute loop_count for cost estimation purposes */
3322 903 : 356285 : loop_count = get_loop_count(root, rel->relid, outer_relids);
904 : :
905 : : /*
906 : : * 2. Compute pathkeys describing index's ordering, if any, then see how
907 : : * many of them are actually useful for this query. This is not relevant
908 : : * if we are only trying to build bitmap indexscans.
909 : : */
4461 910 [ + + + + ]: 711215 : pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN &&
911 : 354930 : has_useful_pathkeys(root, rel));
912 : 356285 : index_is_ordered = (index->sortopfamily != NULL);
913 [ + + + + ]: 356285 : if (index_is_ordered && pathkeys_possibly_useful)
914 : : {
915 : 262861 : index_pathkeys = build_index_pathkeys(root, index,
916 : : ForwardScanDirection);
917 : 262861 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
918 : : index_pathkeys);
919 : 262861 : orderbyclauses = NIL;
920 : 262861 : orderbyclausecols = NIL;
921 : : }
922 [ + + + + ]: 93424 : else if (index->amcanorderbyop && pathkeys_possibly_useful)
923 : : {
924 : : /*
925 : : * See if we can generate ordering operators for query_pathkeys or at
926 : : * least some prefix thereof. Matching to just a prefix of the
927 : : * query_pathkeys will allow an incremental sort to be considered on
928 : : * the index's partially sorted results.
929 : : */
930 : 428 : match_pathkeys_to_index(index, root->query_pathkeys,
931 : : &orderbyclauses,
932 : : &orderbyclausecols);
285 drowley@postgresql.o 933 [ + + ]:GNC 856 : if (list_length(root->query_pathkeys) == list_length(orderbyclauses))
4461 tgl@sss.pgh.pa.us 934 :CBC 234 : useful_pathkeys = root->query_pathkeys;
935 : : else
285 drowley@postgresql.o 936 :GNC 194 : useful_pathkeys = list_copy_head(root->query_pathkeys,
937 : : list_length(orderbyclauses));
938 : : }
939 : : else
940 : : {
4461 tgl@sss.pgh.pa.us 941 :CBC 92996 : useful_pathkeys = NIL;
942 : 92996 : orderbyclauses = NIL;
943 : 92996 : orderbyclausecols = NIL;
944 : : }
945 : :
946 : : /*
947 : : * 3. Check if an index-only scan is possible. If we're not building
948 : : * plain indexscans, this isn't relevant since bitmap scans don't support
949 : : * index data retrieval anyway.
950 : : */
951 [ + + + + ]: 711215 : index_only_scan = (scantype != ST_BITMAPSCAN &&
952 : 354930 : check_index_only(rel, index));
953 : :
954 : : /*
955 : : * 4. Generate an indexscan path if there are relevant restriction clauses
956 : : * in the current clauses, OR the index ordering is potentially useful for
957 : : * later merging or final output ordering, OR the index has a useful
958 : : * predicate, OR an index-only scan is possible.
959 : : */
3458 960 [ + + + + : 356285 : if (index_clauses != NIL || useful_pathkeys != NIL || useful_predicate ||
+ + + + ]
961 : : index_only_scan)
962 : : {
4461 963 : 211210 : ipath = create_index_path(root, index,
964 : : index_clauses,
965 : : orderbyclauses,
966 : : orderbyclausecols,
967 : : useful_pathkeys,
968 : : ForwardScanDirection,
969 : : index_only_scan,
970 : : outer_relids,
971 : : loop_count,
972 : : false);
973 : 211210 : result = lappend(result, ipath);
974 : :
975 : : /*
976 : : * If appropriate, consider parallel index scan. We don't allow
977 : : * parallel index scan for bitmap index scans.
978 : : */
2611 rhaas@postgresql.org 979 [ + + ]: 211210 : if (index->amcanparallel &&
2615 980 [ + + + + : 201183 : rel->consider_parallel && outer_relids == NULL &&
+ + ]
981 : : scantype != ST_BITMAPSCAN)
982 : : {
983 : 110774 : ipath = create_index_path(root, index,
984 : : index_clauses,
985 : : orderbyclauses,
986 : : orderbyclausecols,
987 : : useful_pathkeys,
988 : : ForwardScanDirection,
989 : : index_only_scan,
990 : : outer_relids,
991 : : loop_count,
992 : : true);
993 : :
994 : : /*
995 : : * if, after costing the path, we find that it's not worth using
996 : : * parallel workers, just free it.
997 : : */
998 [ + + ]: 110774 : if (ipath->path.parallel_workers > 0)
999 : 4818 : add_partial_path(rel, (Path *) ipath);
1000 : : else
1001 : 105956 : pfree(ipath);
1002 : : }
1003 : : }
1004 : :
1005 : : /*
1006 : : * 5. If the index is ordered, a backwards scan might be interesting.
1007 : : */
4461 tgl@sss.pgh.pa.us 1008 [ + + + + ]: 356285 : if (index_is_ordered && pathkeys_possibly_useful)
1009 : : {
1010 : 262861 : index_pathkeys = build_index_pathkeys(root, index,
1011 : : BackwardScanDirection);
1012 : 262861 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
1013 : : index_pathkeys);
1014 [ + + ]: 262861 : if (useful_pathkeys != NIL)
1015 : : {
1016 : 265 : ipath = create_index_path(root, index,
1017 : : index_clauses,
1018 : : NIL,
1019 : : NIL,
1020 : : useful_pathkeys,
1021 : : BackwardScanDirection,
1022 : : index_only_scan,
1023 : : outer_relids,
1024 : : loop_count,
1025 : : false);
1026 : 265 : result = lappend(result, ipath);
1027 : :
1028 : : /* If appropriate, consider parallel index scan */
2611 rhaas@postgresql.org 1029 [ + - ]: 265 : if (index->amcanparallel &&
2615 1030 [ + + + + : 265 : rel->consider_parallel && outer_relids == NULL &&
+ - ]
1031 : : scantype != ST_BITMAPSCAN)
1032 : : {
1033 : 220 : ipath = create_index_path(root, index,
1034 : : index_clauses,
1035 : : NIL,
1036 : : NIL,
1037 : : useful_pathkeys,
1038 : : BackwardScanDirection,
1039 : : index_only_scan,
1040 : : outer_relids,
1041 : : loop_count,
1042 : : true);
1043 : :
1044 : : /*
1045 : : * if, after costing the path, we find that it's not worth
1046 : : * using parallel workers, just free it.
1047 : : */
1048 [ + + ]: 220 : if (ipath->path.parallel_workers > 0)
1049 : 84 : add_partial_path(rel, (Path *) ipath);
1050 : : else
1051 : 136 : pfree(ipath);
1052 : : }
1053 : : }
1054 : : }
1055 : :
4461 tgl@sss.pgh.pa.us 1056 : 356285 : return result;
1057 : : }
1058 : :
1059 : : /*
1060 : : * build_paths_for_OR
1061 : : * Given a list of restriction clauses from one arm of an OR clause,
1062 : : * construct all matching IndexPaths for the relation.
1063 : : *
1064 : : * Here we must scan all indexes of the relation, since a bitmap OR tree
1065 : : * can use multiple indexes.
1066 : : *
1067 : : * The caller actually supplies two lists of restriction clauses: some
1068 : : * "current" ones and some "other" ones. Both lists can be used freely
1069 : : * to match keys of the index, but an index must use at least one of the
1070 : : * "current" clauses to be considered usable. The motivation for this is
1071 : : * examples like
1072 : : * WHERE (x = 42) AND (... OR (y = 52 AND z = 77) OR ....)
1073 : : * While we are considering the y/z subclause of the OR, we can use "x = 42"
1074 : : * as one of the available index conditions; but we shouldn't match the
1075 : : * subclause to any index on x alone, because such a Path would already have
1076 : : * been generated at the upper level. So we could use an index on x,y,z
1077 : : * or an index on x,y for the OR subclause, but not an index on just x.
1078 : : * When dealing with a partial index, a match of the index predicate to
1079 : : * one of the "current" clauses also makes the index usable.
1080 : : *
1081 : : * 'rel' is the relation for which we want to generate index paths
1082 : : * 'clauses' is the current list of clauses (RestrictInfo nodes)
1083 : : * 'other_clauses' is the list of additional upper-level clauses
1084 : : */
1085 : : static List *
1086 : 7298 : build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
1087 : : List *clauses, List *other_clauses)
1088 : : {
6932 1089 : 7298 : List *result = NIL;
2489 1090 : 7298 : List *all_clauses = NIL; /* not computed till needed */
1091 : : ListCell *lc;
1092 : :
4461 1093 [ + - + + : 24985 : foreach(lc, rel->indexlist)
+ + ]
1094 : : {
1095 : 17687 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
1096 : : IndexClauseSet clauseset;
1097 : : List *indexpaths;
1098 : : bool useful_predicate;
1099 : :
1100 : : /* Ignore index if it doesn't support bitmap scans */
1101 [ - + ]: 17687 : if (!index->amhasgetbitmap)
4564 tgl@sss.pgh.pa.us 1102 :UBC 0 : continue;
1103 : :
1104 : : /*
1105 : : * Ignore partial indexes that do not match the query. If a partial
1106 : : * index is marked predOK then we know it's OK. Otherwise, we have to
1107 : : * test whether the added clauses are sufficient to imply the
1108 : : * predicate. If so, we can use the index in the current context.
1109 : : *
1110 : : * We set useful_predicate to true iff the predicate was proven using
1111 : : * the current set of clauses. This is needed to prevent matching a
1112 : : * predOK index to an arm of an OR, which would be a legal but
1113 : : * pointlessly inefficient plan. (A better plan will be generated by
1114 : : * just scanning the predOK index alone, no OR.)
1115 : : */
6835 tgl@sss.pgh.pa.us 1116 :CBC 17687 : useful_predicate = false;
1117 [ + + ]: 17687 : if (index->indpred != NIL)
1118 : : {
1119 [ + + ]: 72 : if (index->predOK)
1120 : : {
1121 : : /* Usable, but don't set useful_predicate */
1122 : : }
1123 : : else
1124 : : {
1125 : : /* Form all_clauses if not done already */
1126 [ + + ]: 60 : if (all_clauses == NIL)
1707 1127 : 24 : all_clauses = list_concat_copy(clauses, other_clauses);
1128 : :
2496 rhaas@postgresql.org 1129 [ + + ]: 60 : if (!predicate_implied_by(index->indpred, all_clauses, false))
6756 bruce@momjian.us 1130 : 42 : continue; /* can't use it at all */
1131 : :
2496 rhaas@postgresql.org 1132 [ + - ]: 18 : if (!predicate_implied_by(index->indpred, other_clauses, false))
6835 tgl@sss.pgh.pa.us 1133 : 18 : useful_predicate = true;
1134 : : }
1135 : : }
1136 : :
1137 : : /*
1138 : : * Identify the restriction clauses that can match the index.
1139 : : */
4461 1140 [ + - + - : 599930 : MemSet(&clauseset, 0, sizeof(clauseset));
+ - + - +
+ ]
1889 1141 : 17645 : match_clauses_to_index(root, clauses, index, &clauseset);
1142 : :
1143 : : /*
1144 : : * If no matches so far, and the index predicate isn't useful, we
1145 : : * don't want it.
1146 : : */
4461 1147 [ + + + - ]: 17645 : if (!clauseset.nonempty && !useful_predicate)
6835 1148 : 16306 : continue;
1149 : :
1150 : : /*
1151 : : * Add "other" restriction clauses to the clauseset.
1152 : : */
1889 1153 : 1339 : match_clauses_to_index(root, other_clauses, index, &clauseset);
1154 : :
1155 : : /*
1156 : : * Construct paths if possible.
1157 : : */
4461 1158 : 1339 : indexpaths = build_index_paths(root, rel,
1159 : : index, &clauseset,
1160 : : useful_predicate,
1161 : : ST_BITMAPSCAN,
1162 : : NULL);
1163 : 1339 : result = list_concat(result, indexpaths);
1164 : : }
1165 : :
6932 1166 : 7298 : return result;
1167 : : }
1168 : :
1169 : : /*
1170 : : * generate_bitmap_or_paths
1171 : : * Look through the list of clauses to find OR clauses, and generate
1172 : : * a BitmapOrPath for each one we can handle that way. Return a list
1173 : : * of the generated BitmapOrPaths.
1174 : : *
1175 : : * other_clauses is a list of additional clauses that can be assumed true
1176 : : * for the purpose of generating indexquals, but are not to be searched for
1177 : : * ORs. (See build_paths_for_OR() for motivation.)
1178 : : */
1179 : : static List *
6888 1180 : 280536 : generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
1181 : : List *clauses, List *other_clauses)
1182 : : {
6932 1183 : 280536 : List *result = NIL;
1184 : : List *all_clauses;
1185 : : ListCell *lc;
1186 : :
1187 : : /*
1188 : : * We can use both the current and other clauses as context for
1189 : : * build_paths_for_OR; no need to remove ORs from the lists.
1190 : : */
1707 1191 : 280536 : all_clauses = list_concat_copy(clauses, other_clauses);
1192 : :
4461 1193 [ + + + + : 441086 : foreach(lc, clauses)
+ + ]
1194 : : {
2561 1195 : 160550 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1196 : : List *pathlist;
1197 : : Path *bitmapqual;
1198 : : ListCell *j;
1199 : :
1200 : : /* Ignore RestrictInfos that aren't ORs */
6932 1201 [ + + ]: 160550 : if (!restriction_is_or_clause(rinfo))
1202 : 153988 : continue;
1203 : :
1204 : : /*
1205 : : * We must be able to match at least one index to each of the arms of
1206 : : * the OR, else we can't use it.
1207 : : */
1208 : 6562 : pathlist = NIL;
1209 [ + - + + : 7778 : foreach(j, ((BoolExpr *) rinfo->orclause)->args)
+ + ]
1210 : : {
6756 bruce@momjian.us 1211 : 7298 : Node *orarg = (Node *) lfirst(j);
1212 : : List *indlist;
1213 : :
1214 : : /* OR arguments should be ANDs or sub-RestrictInfos */
1902 tgl@sss.pgh.pa.us 1215 [ + + ]: 7298 : if (is_andclause(orarg))
1216 : : {
6756 bruce@momjian.us 1217 : 1138 : List *andargs = ((BoolExpr *) orarg)->args;
1218 : :
4461 tgl@sss.pgh.pa.us 1219 : 1138 : indlist = build_paths_for_OR(root, rel,
1220 : : andargs,
1221 : : all_clauses);
1222 : :
1223 : : /* Recurse in case there are sub-ORs */
6932 1224 : 1138 : indlist = list_concat(indlist,
1225 : 1138 : generate_bitmap_or_paths(root, rel,
1226 : : andargs,
1227 : : all_clauses));
1228 : : }
1229 : : else
1230 : : {
557 drowley@postgresql.o 1231 : 6160 : RestrictInfo *ri = castNode(RestrictInfo, orarg);
1232 : : List *orargs;
1233 : :
1234 [ - + ]: 6160 : Assert(!restriction_is_or_clause(ri));
1235 : 6160 : orargs = list_make1(ri);
1236 : :
4461 tgl@sss.pgh.pa.us 1237 : 6160 : indlist = build_paths_for_OR(root, rel,
1238 : : orargs,
1239 : : all_clauses);
1240 : : }
1241 : :
1242 : : /*
1243 : : * If nothing matched this arm, we can't do anything with this OR
1244 : : * clause.
1245 : : */
6932 1246 [ + + ]: 7298 : if (indlist == NIL)
1247 : : {
1248 : 6082 : pathlist = NIL;
1249 : 6082 : break;
1250 : : }
1251 : :
1252 : : /*
1253 : : * OK, pick the most promising AND combination, and add it to
1254 : : * pathlist.
1255 : : */
4461 1256 : 1216 : bitmapqual = choose_bitmap_and(root, rel, indlist);
6932 1257 : 1216 : pathlist = lappend(pathlist, bitmapqual);
1258 : : }
1259 : :
1260 : : /*
1261 : : * If we have a match for every arm, then turn them into a
1262 : : * BitmapOrPath, and add to result list.
1263 : : */
1264 [ + + ]: 6562 : if (pathlist != NIL)
1265 : : {
1266 : 480 : bitmapqual = (Path *) create_bitmap_or_path(root, rel, pathlist);
1267 : 480 : result = lappend(result, bitmapqual);
1268 : : }
1269 : : }
1270 : :
1271 : 280536 : return result;
1272 : : }
1273 : :
1274 : :
1275 : : /*
1276 : : * choose_bitmap_and
1277 : : * Given a nonempty list of bitmap paths, AND them into one path.
1278 : : *
1279 : : * This is a nontrivial decision since we can legally use any subset of the
1280 : : * given path set. We want to choose a good tradeoff between selectivity
1281 : : * and cost of computing the bitmap.
1282 : : *
1283 : : * The result is either a single one of the inputs, or a BitmapAndPath
1284 : : * combining multiple inputs.
1285 : : */
1286 : : static Path *
4461 1287 : 144610 : choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
1288 : : {
6931 1289 : 144610 : int npaths = list_length(paths);
1290 : : PathClauseUsage **pathinfoarray;
1291 : : PathClauseUsage *pathinfo;
1292 : : List *clauselist;
6207 1293 : 144610 : List *bestpaths = NIL;
1294 : 144610 : Cost bestcost = 0;
1295 : : int i,
1296 : : j;
1297 : : ListCell *l;
1298 : :
6756 bruce@momjian.us 1299 [ - + ]: 144610 : Assert(npaths > 0); /* else caller error */
6931 tgl@sss.pgh.pa.us 1300 [ + + ]: 144610 : if (npaths == 1)
2489 1301 : 116239 : return (Path *) linitial(paths); /* easy case */
1302 : :
1303 : : /*
1304 : : * In theory we should consider every nonempty subset of the given paths.
1305 : : * In practice that seems like overkill, given the crude nature of the
1306 : : * estimates, not to mention the possible effects of higher-level AND and
1307 : : * OR clauses. Moreover, it's completely impractical if there are a large
1308 : : * number of paths, since the work would grow as O(2^N).
1309 : : *
1310 : : * As a heuristic, we first check for paths using exactly the same sets of
1311 : : * WHERE clauses + index predicate conditions, and reject all but the
1312 : : * cheapest-to-scan in any such group. This primarily gets rid of indexes
1313 : : * that include the interesting columns but also irrelevant columns. (In
1314 : : * situations where the DBA has gone overboard on creating variant
1315 : : * indexes, this can make for a very large reduction in the number of
1316 : : * paths considered further.)
1317 : : *
1318 : : * We then sort the surviving paths with the cheapest-to-scan first, and
1319 : : * for each path, consider using that path alone as the basis for a bitmap
1320 : : * scan. Then we consider bitmap AND scans formed from that path plus
1321 : : * each subsequent (higher-cost) path, adding on a subsequent path if it
1322 : : * results in a reduction in the estimated total scan cost. This means we
1323 : : * consider about O(N^2) rather than O(2^N) path combinations, which is
1324 : : * quite tolerable, especially given than N is usually reasonably small
1325 : : * because of the prefiltering step. The cheapest of these is returned.
1326 : : *
1327 : : * We will only consider AND combinations in which no two indexes use the
1328 : : * same WHERE clause. This is a bit of a kluge: it's needed because
1329 : : * costsize.c and clausesel.c aren't very smart about redundant clauses.
1330 : : * They will usually double-count the redundant clauses, producing a
1331 : : * too-small selectivity that makes a redundant AND step look like it
1332 : : * reduces the total cost. Perhaps someday that code will be smarter and
1333 : : * we can remove this limitation. (But note that this also defends
1334 : : * against flat-out duplicate input paths, which can happen because
1335 : : * match_join_clauses_to_index will find the same OR join clauses that
1336 : : * extract_restriction_or_clauses has pulled OR restriction clauses out
1337 : : * of.)
1338 : : *
1339 : : * For the same reason, we reject AND combinations in which an index
1340 : : * predicate clause duplicates another clause. Here we find it necessary
1341 : : * to be even stricter: we'll reject a partial index if any of its
1342 : : * predicate clauses are implied by the set of WHERE clauses and predicate
1343 : : * clauses used so far. This covers cases such as a condition "x = 42"
1344 : : * used with a plain index, followed by a clauseless scan of a partial
1345 : : * index "WHERE x >= 40 AND x < 50". The partial index has been accepted
1346 : : * only because "x = 42" was present, and so allowing it would partially
1347 : : * double-count selectivity. (We could use predicate_implied_by on
1348 : : * regular qual clauses too, to have a more intelligent, but much more
1349 : : * expensive, check for redundancy --- but in most cases simple equality
1350 : : * seems to suffice.)
1351 : : */
1352 : :
1353 : : /*
1354 : : * Extract clause usage info and detect any paths that use exactly the
1355 : : * same set of clauses; keep only the cheapest-to-scan of any such groups.
1356 : : * The surviving paths are put into an array for qsort'ing.
1357 : : */
1358 : : pathinfoarray = (PathClauseUsage **)
6207 1359 : 28371 : palloc(npaths * sizeof(PathClauseUsage *));
1360 : 28371 : clauselist = NIL;
1361 : 28371 : npaths = 0;
6931 1362 [ + - + + : 93657 : foreach(l, paths)
+ + ]
1363 : : {
5995 bruce@momjian.us 1364 : 65286 : Path *ipath = (Path *) lfirst(l);
1365 : :
6207 tgl@sss.pgh.pa.us 1366 : 65286 : pathinfo = classify_index_clause_usage(ipath, &clauselist);
1367 : :
1368 : : /* If it's unclassifiable, treat it as distinct from all others */
1980 1369 [ - + ]: 65286 : if (pathinfo->unclassifiable)
1370 : : {
1980 tgl@sss.pgh.pa.us 1371 :UBC 0 : pathinfoarray[npaths++] = pathinfo;
1372 : 0 : continue;
1373 : : }
1374 : :
6207 tgl@sss.pgh.pa.us 1375 [ + + ]:CBC 102286 : for (i = 0; i < npaths; i++)
1376 : : {
1980 1377 [ + - + + ]: 90716 : if (!pathinfoarray[i]->unclassifiable &&
1378 : 45358 : bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
6207 1379 : 8358 : break;
1380 : : }
1381 [ + + ]: 65286 : if (i < npaths)
1382 : : {
1383 : : /* duplicate clauseids, keep the cheaper one */
1384 : : Cost ncost;
1385 : : Cost ocost;
1386 : : Selectivity nselec;
1387 : : Selectivity oselec;
1388 : :
1389 : 8358 : cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
1390 : 8358 : cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
1391 [ + + ]: 8358 : if (ncost < ocost)
1392 : 1318 : pathinfoarray[i] = pathinfo;
1393 : : }
1394 : : else
1395 : : {
1396 : : /* not duplicate clauseids, add to array */
1397 : 56928 : pathinfoarray[npaths++] = pathinfo;
1398 : : }
1399 : : }
1400 : :
1401 : : /* If only one surviving path, we're done */
1402 [ + + ]: 28371 : if (npaths == 1)
1403 : 4977 : return pathinfoarray[0]->path;
1404 : :
1405 : : /* Sort the surviving paths by index access cost */
1406 : 23394 : qsort(pathinfoarray, npaths, sizeof(PathClauseUsage *),
1407 : : path_usage_comparator);
1408 : :
1409 : : /*
1410 : : * For each surviving index, consider it as an "AND group leader", and see
1411 : : * whether adding on any of the later indexes results in an AND path with
1412 : : * cheaper total cost than before. Then take the cheapest AND group.
1413 : : *
1414 : : * Note: paths that are either clauseless or unclassifiable will have
1415 : : * empty clauseids, so that they will not be rejected by the clauseids
1416 : : * filter here, nor will they cause later paths to be rejected by it.
1417 : : */
1418 [ + + ]: 75345 : for (i = 0; i < npaths; i++)
1419 : : {
1420 : : Cost costsofar;
1421 : : List *qualsofar;
1422 : : Bitmapset *clauseidsofar;
1423 : :
1424 : 51951 : pathinfo = pathinfoarray[i];
1425 : 51951 : paths = list_make1(pathinfo->path);
4461 1426 : 51951 : costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
1707 1427 : 51951 : qualsofar = list_concat_copy(pathinfo->quals, pathinfo->preds);
6207 1428 : 51951 : clauseidsofar = bms_copy(pathinfo->clauseids);
1429 : :
5995 bruce@momjian.us 1430 [ + + ]: 85899 : for (j = i + 1; j < npaths; j++)
1431 : : {
1432 : : Cost newcost;
1433 : :
6207 tgl@sss.pgh.pa.us 1434 : 33948 : pathinfo = pathinfoarray[j];
1435 : : /* Check for redundancy */
1436 [ + + ]: 33948 : if (bms_overlap(pathinfo->clauseids, clauseidsofar))
5995 bruce@momjian.us 1437 : 16957 : continue; /* consider it redundant */
6207 tgl@sss.pgh.pa.us 1438 [ + + ]: 16991 : if (pathinfo->preds)
1439 : : {
5995 bruce@momjian.us 1440 : 12 : bool redundant = false;
1441 : :
1442 : : /* we check each predicate clause separately */
6207 tgl@sss.pgh.pa.us 1443 [ + - + - : 12 : foreach(l, pathinfo->preds)
+ - ]
1444 : : {
1445 : 12 : Node *np = (Node *) lfirst(l);
1446 : :
2496 rhaas@postgresql.org 1447 [ + - ]: 12 : if (predicate_implied_by(list_make1(np), qualsofar, false))
1448 : : {
6207 tgl@sss.pgh.pa.us 1449 : 12 : redundant = true;
5995 bruce@momjian.us 1450 : 12 : break; /* out of inner foreach loop */
1451 : : }
1452 : : }
6207 tgl@sss.pgh.pa.us 1453 [ + - ]: 12 : if (redundant)
1454 : 12 : continue;
1455 : : }
1456 : : /* tentatively add new path to paths, so we can estimate cost */
1457 : 16979 : paths = lappend(paths, pathinfo->path);
4461 1458 : 16979 : newcost = bitmap_and_cost_est(root, rel, paths);
6207 1459 [ + + ]: 16979 : if (newcost < costsofar)
1460 : : {
1461 : : /* keep new path in paths, update subsidiary variables */
1462 : 71 : costsofar = newcost;
1707 1463 : 71 : qualsofar = list_concat(qualsofar, pathinfo->quals);
1464 : 71 : qualsofar = list_concat(qualsofar, pathinfo->preds);
6207 1465 : 71 : clauseidsofar = bms_add_members(clauseidsofar,
1466 : 71 : pathinfo->clauseids);
1467 : : }
1468 : : else
1469 : : {
1470 : : /* reject new path, remove it from paths list */
1735 1471 : 16908 : paths = list_truncate(paths, list_length(paths) - 1);
1472 : : }
1473 : : }
1474 : :
1475 : : /* Keep the cheapest AND-group (or singleton) */
6207 1476 [ + + + + ]: 51951 : if (i == 0 || costsofar < bestcost)
1477 : : {
1478 : 24999 : bestpaths = paths;
1479 : 24999 : bestcost = costsofar;
1480 : : }
1481 : :
1482 : : /* some easy cleanup (we don't try real hard though) */
1483 : 51951 : list_free(qualsofar);
1484 : : }
1485 : :
1486 [ + + ]: 23394 : if (list_length(bestpaths) == 1)
5995 bruce@momjian.us 1487 : 23335 : return (Path *) linitial(bestpaths); /* no need for AND */
6207 tgl@sss.pgh.pa.us 1488 : 59 : return (Path *) create_bitmap_and_path(root, rel, bestpaths);
1489 : : }
1490 : :
1491 : : /* qsort comparator to sort in increasing index access cost order */
1492 : : static int
1493 : 31747 : path_usage_comparator(const void *a, const void *b)
1494 : : {
5995 bruce@momjian.us 1495 : 31747 : PathClauseUsage *pa = *(PathClauseUsage *const *) a;
1496 : 31747 : PathClauseUsage *pb = *(PathClauseUsage *const *) b;
1497 : : Cost acost;
1498 : : Cost bcost;
1499 : : Selectivity aselec;
1500 : : Selectivity bselec;
1501 : :
6207 tgl@sss.pgh.pa.us 1502 : 31747 : cost_bitmap_tree_node(pa->path, &acost, &aselec);
1503 : 31747 : cost_bitmap_tree_node(pb->path, &bcost, &bselec);
1504 : :
1505 : : /*
1506 : : * If costs are the same, sort by selectivity.
1507 : : */
1508 [ + + ]: 31747 : if (acost < bcost)
6931 1509 : 18979 : return -1;
6207 1510 [ + + ]: 12768 : if (acost > bcost)
6931 1511 : 8383 : return 1;
1512 : :
6207 1513 [ + + ]: 4385 : if (aselec < bselec)
6931 1514 : 1748 : return -1;
6207 1515 [ + + ]: 2637 : if (aselec > bselec)
6931 1516 : 416 : return 1;
1517 : :
1518 : 2221 : return 0;
1519 : : }
1520 : :
1521 : : /*
1522 : : * Estimate the cost of actually executing a bitmap scan with a single
1523 : : * index path (which could be a BitmapAnd or BitmapOr node).
1524 : : */
1525 : : static Cost
4461 1526 : 68930 : bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
1527 : : {
1528 : : BitmapHeapPath bpath;
1529 : :
1530 : : /* Set up a dummy BitmapHeapPath */
1531 : 68930 : bpath.path.type = T_BitmapHeapPath;
1532 : 68930 : bpath.path.pathtype = T_BitmapHeapScan;
1533 : 68930 : bpath.path.parent = rel;
2953 1534 : 68930 : bpath.path.pathtarget = rel->reltarget;
1370 1535 : 68930 : bpath.path.param_info = ipath->param_info;
4461 1536 : 68930 : bpath.path.pathkeys = NIL;
1537 : 68930 : bpath.bitmapqual = ipath;
1538 : :
1539 : : /*
1540 : : * Check the cost of temporary path without considering parallelism.
1541 : : * Parallel bitmap heap path will be considered at later stage.
1542 : : */
2594 rhaas@postgresql.org 1543 : 68930 : bpath.path.parallel_workers = 0;
1544 : :
1545 : : /* Now we can do cost_bitmap_heap_scan */
4378 tgl@sss.pgh.pa.us 1546 : 68930 : cost_bitmap_heap_scan(&bpath.path, root, rel,
1547 : : bpath.path.param_info,
1548 : : ipath,
1549 : : get_loop_count(root, rel->relid,
1370 1550 [ + + ]: 68930 : PATH_REQ_OUTER(ipath)));
1551 : :
4461 1552 : 68930 : return bpath.path.total_cost;
1553 : : }
1554 : :
1555 : : /*
1556 : : * Estimate the cost of actually executing a BitmapAnd scan with the given
1557 : : * inputs.
1558 : : */
1559 : : static Cost
1560 : 16979 : bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
1561 : : {
1562 : : BitmapAndPath *apath;
1563 : :
1564 : : /*
1565 : : * Might as well build a real BitmapAndPath here, as the work is slightly
1566 : : * too complicated to be worth repeating just to save one palloc.
1567 : : */
1370 1568 : 16979 : apath = create_bitmap_and_path(root, rel, paths);
1569 : :
1570 : 16979 : return bitmap_scan_cost_est(root, rel, (Path *) apath);
1571 : : }
1572 : :
1573 : :
1574 : : /*
1575 : : * classify_index_clause_usage
1576 : : * Construct a PathClauseUsage struct describing the WHERE clauses and
1577 : : * index predicate clauses used by the given indexscan path.
1578 : : * We consider two clauses the same if they are equal().
1579 : : *
1580 : : * At some point we might want to migrate this info into the Path data
1581 : : * structure proper, but for the moment it's only needed within
1582 : : * choose_bitmap_and().
1583 : : *
1584 : : * *clauselist is used and expanded as needed to identify all the distinct
1585 : : * clauses seen across successive calls. Caller must initialize it to NIL
1586 : : * before first call of a set.
1587 : : */
1588 : : static PathClauseUsage *
6207 1589 : 65286 : classify_index_clause_usage(Path *path, List **clauselist)
1590 : : {
1591 : : PathClauseUsage *result;
1592 : : Bitmapset *clauseids;
1593 : : ListCell *lc;
1594 : :
1595 : 65286 : result = (PathClauseUsage *) palloc(sizeof(PathClauseUsage));
1596 : 65286 : result->path = path;
1597 : :
1598 : : /* Recursively find the quals and preds used by the path */
1599 : 65286 : result->quals = NIL;
1600 : 65286 : result->preds = NIL;
1601 : 65286 : find_indexpath_quals(path, &result->quals, &result->preds);
1602 : :
1603 : : /*
1604 : : * Some machine-generated queries have outlandish numbers of qual clauses.
1605 : : * To avoid getting into O(N^2) behavior even in this preliminary
1606 : : * classification step, we want to limit the number of entries we can
1607 : : * accumulate in *clauselist. Treat any path with more than 100 quals +
1608 : : * preds as unclassifiable, which will cause calling code to consider it
1609 : : * distinct from all other paths.
1610 : : */
1980 1611 [ - + ]: 65286 : if (list_length(result->quals) + list_length(result->preds) > 100)
1612 : : {
1980 tgl@sss.pgh.pa.us 1613 :UBC 0 : result->clauseids = NULL;
1614 : 0 : result->unclassifiable = true;
1615 : 0 : return result;
1616 : : }
1617 : :
1618 : : /* Build up a bitmapset representing the quals and preds */
6207 tgl@sss.pgh.pa.us 1619 :CBC 65286 : clauseids = NULL;
1620 [ + + + + : 149635 : foreach(lc, result->quals)
+ + ]
1621 : : {
5995 bruce@momjian.us 1622 : 84349 : Node *node = (Node *) lfirst(lc);
1623 : :
6207 tgl@sss.pgh.pa.us 1624 : 84349 : clauseids = bms_add_member(clauseids,
1625 : : find_list_position(node, clauselist));
1626 : : }
1627 [ + + + + : 65433 : foreach(lc, result->preds)
+ + ]
1628 : : {
5995 bruce@momjian.us 1629 : 147 : Node *node = (Node *) lfirst(lc);
1630 : :
6207 tgl@sss.pgh.pa.us 1631 : 147 : clauseids = bms_add_member(clauseids,
1632 : : find_list_position(node, clauselist));
1633 : : }
1634 : 65286 : result->clauseids = clauseids;
1980 1635 : 65286 : result->unclassifiable = false;
1636 : :
6207 1637 : 65286 : return result;
1638 : : }
1639 : :
1640 : :
1641 : : /*
1642 : : * find_indexpath_quals
1643 : : *
1644 : : * Given the Path structure for a plain or bitmap indexscan, extract lists
1645 : : * of all the index clauses and index predicate conditions used in the Path.
1646 : : * These are appended to the initial contents of *quals and *preds (hence
1647 : : * caller should initialize those to NIL).
1648 : : *
1649 : : * Note we are not trying to produce an accurate representation of the AND/OR
1650 : : * semantics of the Path, but just find out all the base conditions used.
1651 : : *
1652 : : * The result lists contain pointers to the expressions used in the Path,
1653 : : * but all the list cells are freshly built, so it's safe to destructively
1654 : : * modify the lists (eg, by concat'ing with other lists).
1655 : : */
1656 : : static void
6234 1657 : 66609 : find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
1658 : : {
6580 1659 [ - + ]: 66609 : if (IsA(bitmapqual, BitmapAndPath))
1660 : : {
6580 tgl@sss.pgh.pa.us 1661 :UBC 0 : BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
1662 : : ListCell *l;
1663 : :
1664 [ # # # # : 0 : foreach(l, apath->bitmapquals)
# # ]
1665 : : {
6207 1666 : 0 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
1667 : : }
1668 : : }
6580 tgl@sss.pgh.pa.us 1669 [ + + ]:CBC 66609 : else if (IsA(bitmapqual, BitmapOrPath))
1670 : : {
1671 : 645 : BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
1672 : : ListCell *l;
1673 : :
1674 [ + - + + : 1968 : foreach(l, opath->bitmapquals)
+ + ]
1675 : : {
6207 1676 : 1323 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
1677 : : }
1678 : : }
6580 1679 [ + - ]: 65964 : else if (IsA(bitmapqual, IndexPath))
1680 : : {
1681 : 65964 : IndexPath *ipath = (IndexPath *) bitmapqual;
1682 : : ListCell *l;
1683 : :
1891 1684 [ + + + + : 150313 : foreach(l, ipath->indexclauses)
+ + ]
1685 : : {
1686 : 84349 : IndexClause *iclause = (IndexClause *) lfirst(l);
1687 : :
1688 : 84349 : *quals = lappend(*quals, iclause->rinfo->clause);
1689 : : }
1707 1690 : 65964 : *preds = list_concat(*preds, ipath->indexinfo->indpred);
1691 : : }
1692 : : else
6580 tgl@sss.pgh.pa.us 1693 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
6580 tgl@sss.pgh.pa.us 1694 :CBC 66609 : }
1695 : :
1696 : :
1697 : : /*
1698 : : * find_list_position
1699 : : * Return the given node's position (counting from 0) in the given
1700 : : * list of nodes. If it's not equal() to any existing list member,
1701 : : * add it at the end, and return that position.
1702 : : */
1703 : : static int
6207 1704 : 84496 : find_list_position(Node *node, List **nodelist)
1705 : : {
1706 : : int i;
1707 : : ListCell *lc;
1708 : :
1709 : 84496 : i = 0;
1710 [ + + + + : 130065 : foreach(lc, *nodelist)
+ + ]
1711 : : {
5995 bruce@momjian.us 1712 : 72233 : Node *oldnode = (Node *) lfirst(lc);
1713 : :
6207 tgl@sss.pgh.pa.us 1714 [ + + ]: 72233 : if (equal(node, oldnode))
1715 : 26664 : return i;
1716 : 45569 : i++;
1717 : : }
1718 : :
1719 : 57832 : *nodelist = lappend(*nodelist, node);
1720 : :
1721 : 57832 : return i;
1722 : : }
1723 : :
1724 : :
1725 : : /*
1726 : : * check_index_only
1727 : : * Determine whether an index-only scan is possible for this index.
1728 : : */
1729 : : static bool
4573 1730 : 354930 : check_index_only(RelOptInfo *rel, IndexOptInfo *index)
1731 : : {
1732 : : bool result;
1733 : 354930 : Bitmapset *attrs_used = NULL;
3307 heikki.linnakangas@i 1734 : 354930 : Bitmapset *index_canreturn_attrs = NULL;
1735 : : ListCell *lc;
1736 : : int i;
1737 : :
1738 : : /* Index-only scans must be enabled */
4573 tgl@sss.pgh.pa.us 1739 [ + + ]: 354930 : if (!enable_indexonlyscan)
1740 : 1921 : return false;
1741 : :
1742 : : /*
1743 : : * Check that all needed attributes of the relation are available from the
1744 : : * index.
1745 : : */
1746 : :
1747 : : /*
1748 : : * First, identify all the attributes needed for joins or final output.
1749 : : * Note: we must look at rel's targetlist, not the attr_needed data,
1750 : : * because attr_needed isn't computed for inheritance child rels.
1751 : : */
2953 1752 : 353009 : pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
1753 : :
1754 : : /*
1755 : : * Add all the attributes used by restriction clauses; but consider only
1756 : : * those clauses not implied by the index predicate, since ones that are
1757 : : * so implied don't need to be checked explicitly in the plan.
1758 : : *
1759 : : * Note: attributes used only in index quals would not be needed at
1760 : : * runtime either, if we are certain that the index is not lossy. However
1761 : : * it'd be complicated to account for that accurately, and it doesn't
1762 : : * matter in most cases, since we'd conclude that such attributes are
1763 : : * available from the index anyway.
1764 : : */
2936 1765 [ + + + + : 723127 : foreach(lc, index->indrestrictinfo)
+ + ]
1766 : : {
4326 bruce@momjian.us 1767 : 370118 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
1768 : :
4573 tgl@sss.pgh.pa.us 1769 : 370118 : pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
1770 : : }
1771 : :
1772 : : /*
1773 : : * Construct a bitmapset of columns that the index can return back in an
1774 : : * index-only scan.
1775 : : */
1776 [ + + ]: 1013329 : for (i = 0; i < index->ncolumns; i++)
1777 : : {
4326 bruce@momjian.us 1778 : 660320 : int attno = index->indexkeys[i];
1779 : :
1780 : : /*
1781 : : * For the moment, we just ignore index expressions. It might be nice
1782 : : * to do something with them, later.
1783 : : */
4569 tgl@sss.pgh.pa.us 1784 [ + + ]: 660320 : if (attno == 0)
4573 1785 : 1623 : continue;
1786 : :
3307 heikki.linnakangas@i 1787 [ + + ]: 658697 : if (index->canreturn[i])
1788 : : index_canreturn_attrs =
1789 : 521355 : bms_add_member(index_canreturn_attrs,
1790 : : attno - FirstLowInvalidHeapAttributeNumber);
1791 : : }
1792 : :
1793 : : /* Do we have all the necessary attributes? */
1794 : 353009 : result = bms_is_subset(attrs_used, index_canreturn_attrs);
1795 : :
4573 tgl@sss.pgh.pa.us 1796 : 353009 : bms_free(attrs_used);
3307 heikki.linnakangas@i 1797 : 353009 : bms_free(index_canreturn_attrs);
1798 : :
4573 tgl@sss.pgh.pa.us 1799 : 353009 : return result;
1800 : : }
1801 : :
1802 : : /*
1803 : : * get_loop_count
1804 : : * Choose the loop count estimate to use for costing a parameterized path
1805 : : * with the given set of outer relids.
1806 : : *
1807 : : * Since we produce parameterized paths before we've begun to generate join
1808 : : * relations, it's impossible to predict exactly how many times a parameterized
1809 : : * path will be iterated; we don't know the size of the relation that will be
1810 : : * on the outside of the nestloop. However, we should try to account for
1811 : : * multiple iterations somehow in costing the path. The heuristic embodied
1812 : : * here is to use the rowcount of the smallest other base relation needed in
1813 : : * the join clauses used by the path. (We could alternatively consider the
1814 : : * largest one, but that seems too optimistic.) This is of course the right
1815 : : * answer for single-other-relation cases, and it seems like a reasonable
1816 : : * zero-order approximation for multiway-join cases.
1817 : : *
1818 : : * In addition, we check to see if the other side of each join clause is on
1819 : : * the inside of some semijoin that the current relation is on the outside of.
1820 : : * If so, the only way that a parameterized path could be used is if the
1821 : : * semijoin RHS has been unique-ified, so we should use the number of unique
1822 : : * RHS rows rather than using the relation's raw rowcount.
1823 : : *
1824 : : * Note: for this to work, allpaths.c must establish all baserel size
1825 : : * estimates before it begins to compute paths, or at least before it
1826 : : * calls create_index_paths().
1827 : : */
1828 : : static double
3322 1829 : 480933 : get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
1830 : : {
1831 : : double result;
1832 : : int outer_relid;
1833 : :
1834 : : /* For a non-parameterized path, just return 1.0 quickly */
1835 [ + + ]: 480933 : if (outer_relids == NULL)
1836 : 334623 : return 1.0;
1837 : :
1838 : 146310 : result = 0.0;
1839 : 146310 : outer_relid = -1;
1840 [ + + ]: 297386 : while ((outer_relid = bms_next_member(outer_relids, outer_relid)) >= 0)
1841 : : {
1842 : : RelOptInfo *outer_rel;
1843 : : double rowcount;
1844 : :
1845 : : /* Paranoia: ignore bogus relid indexes */
1846 [ - + ]: 151076 : if (outer_relid >= root->simple_rel_array_size)
3322 tgl@sss.pgh.pa.us 1847 :UBC 0 : continue;
3322 tgl@sss.pgh.pa.us 1848 :CBC 151076 : outer_rel = root->simple_rel_array[outer_relid];
1849 [ + + ]: 151076 : if (outer_rel == NULL)
1850 : 131 : continue;
2489 1851 [ - + ]: 150945 : Assert(outer_rel->relid == outer_relid); /* sanity check on array */
1852 : :
1853 : : /* Other relation could be proven empty, if so ignore */
3322 1854 [ + + ]: 150945 : if (IS_DUMMY_REL(outer_rel))
1855 : 12 : continue;
1856 : :
1857 : : /* Otherwise, rel's rows estimate should be valid by now */
1858 [ - + ]: 150933 : Assert(outer_rel->rows > 0);
1859 : :
1860 : : /* Check to see if rel is on the inside of any semijoins */
1861 : 150933 : rowcount = adjust_rowcount_for_semijoins(root,
1862 : : cur_relid,
1863 : : outer_relid,
1864 : : outer_rel->rows);
1865 : :
1866 : : /* Remember smallest row count estimate among the outer rels */
1867 [ + + + + ]: 150933 : if (result == 0.0 || result > rowcount)
1868 : 148617 : result = rowcount;
1869 : : }
1870 : : /* Return 1.0 if we found no valid relations (shouldn't happen) */
1871 [ + + ]: 146310 : return (result > 0.0) ? result : 1.0;
1872 : : }
1873 : :
1874 : : /*
1875 : : * Check to see if outer_relid is on the inside of any semijoin that cur_relid
1876 : : * is on the outside of. If so, replace rowcount with the estimated number of
1877 : : * unique rows from the semijoin RHS (assuming that's smaller, which it might
1878 : : * not be). The estimate is crude but it's the best we can do at this stage
1879 : : * of the proceedings.
1880 : : */
1881 : : static double
1882 : 150933 : adjust_rowcount_for_semijoins(PlannerInfo *root,
1883 : : Index cur_relid,
1884 : : Index outer_relid,
1885 : : double rowcount)
1886 : : {
1887 : : ListCell *lc;
1888 : :
1889 [ + + + + : 251233 : foreach(lc, root->join_info_list)
+ + ]
1890 : : {
1891 : 100300 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
1892 : :
1893 [ + + + + ]: 103393 : if (sjinfo->jointype == JOIN_SEMI &&
1894 [ + + ]: 4205 : bms_is_member(cur_relid, sjinfo->syn_lefthand) &&
1895 : 1112 : bms_is_member(outer_relid, sjinfo->syn_righthand))
1896 : : {
1897 : : /* Estimate number of unique-ified rows */
1898 : : double nraw;
1899 : : double nunique;
1900 : :
1901 : 436 : nraw = approximate_joinrel_size(root, sjinfo->syn_righthand);
1902 : 436 : nunique = estimate_num_groups(root,
1903 : : sjinfo->semi_rhs_exprs,
1904 : : nraw,
1905 : : NULL,
1906 : : NULL);
1907 [ + + ]: 436 : if (rowcount > nunique)
1908 : 171 : rowcount = nunique;
1909 : : }
1910 : : }
1911 : 150933 : return rowcount;
1912 : : }
1913 : :
1914 : : /*
1915 : : * Make an approximate estimate of the size of a joinrel.
1916 : : *
1917 : : * We don't have enough info at this point to get a good estimate, so we
1918 : : * just multiply the base relation sizes together. Fortunately, this is
1919 : : * the right answer anyway for the most common case with a single relation
1920 : : * on the RHS of a semijoin. Also, estimate_num_groups() has only a weak
1921 : : * dependency on its input_rows argument (it basically uses it as a clamp).
1922 : : * So we might be able to get a fairly decent end result even with a severe
1923 : : * overestimate of the RHS's raw size.
1924 : : */
1925 : : static double
1926 : 436 : approximate_joinrel_size(PlannerInfo *root, Relids relids)
1927 : : {
1928 : 436 : double rowcount = 1.0;
1929 : : int relid;
1930 : :
1931 : 436 : relid = -1;
1932 [ + + ]: 950 : while ((relid = bms_next_member(relids, relid)) >= 0)
1933 : : {
1934 : : RelOptInfo *rel;
1935 : :
1936 : : /* Paranoia: ignore bogus relid indexes */
1937 [ - + ]: 514 : if (relid >= root->simple_rel_array_size)
3322 tgl@sss.pgh.pa.us 1938 :UBC 0 : continue;
3322 tgl@sss.pgh.pa.us 1939 :CBC 514 : rel = root->simple_rel_array[relid];
1940 [ - + ]: 514 : if (rel == NULL)
3322 tgl@sss.pgh.pa.us 1941 :UBC 0 : continue;
3322 tgl@sss.pgh.pa.us 1942 [ - + ]:CBC 514 : Assert(rel->relid == relid); /* sanity check on array */
1943 : :
1944 : : /* Relation could be proven empty, if so ignore */
1945 [ - + ]: 514 : if (IS_DUMMY_REL(rel))
3322 tgl@sss.pgh.pa.us 1946 :UBC 0 : continue;
1947 : :
1948 : : /* Otherwise, rel's rows estimate should be valid by now */
3322 tgl@sss.pgh.pa.us 1949 [ - + ]:CBC 514 : Assert(rel->rows > 0);
1950 : :
1951 : : /* Accumulate product */
1952 : 514 : rowcount *= rel->rows;
1953 : : }
1954 : 436 : return rowcount;
1955 : : }
1956 : :
1957 : :
1958 : : /****************************************************************************
1959 : : * ---- ROUTINES TO CHECK QUERY CLAUSES ----
1960 : : ****************************************************************************/
1961 : :
1962 : : /*
1963 : : * match_restriction_clauses_to_index
1964 : : * Identify restriction clauses for the rel that match the index.
1965 : : * Matching clauses are added to *clauseset.
1966 : : */
1967 : : static void
1889 1968 : 296906 : match_restriction_clauses_to_index(PlannerInfo *root,
1969 : : IndexOptInfo *index,
1970 : : IndexClauseSet *clauseset)
1971 : : {
1972 : : /* We can ignore clauses that are implied by the index predicate */
1973 : 296906 : match_clauses_to_index(root, index->indrestrictinfo, index, clauseset);
4461 1974 : 296906 : }
1975 : :
1976 : : /*
1977 : : * match_join_clauses_to_index
1978 : : * Identify join clauses for the rel that match the index.
1979 : : * Matching clauses are added to *clauseset.
1980 : : * Also, add any potentially usable join OR clauses to *joinorclauses.
1981 : : */
1982 : : static void
1983 : 296906 : match_join_clauses_to_index(PlannerInfo *root,
1984 : : RelOptInfo *rel, IndexOptInfo *index,
1985 : : IndexClauseSet *clauseset,
1986 : : List **joinorclauses)
1987 : : {
1988 : : ListCell *lc;
1989 : :
1990 : : /* Scan the rel's join clauses */
1991 [ + + + + : 415627 : foreach(lc, rel->joininfo)
+ + ]
1992 : : {
1993 : 118721 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
1994 : :
1995 : : /* Check if clause can be moved to this rel */
3893 1996 [ + + ]: 118721 : if (!join_clause_is_movable_to(rinfo, rel))
4245 1997 : 70805 : continue;
1998 : :
1999 : : /* Potentially usable, so see if it matches the index or is an OR */
4461 2000 [ + + ]: 47916 : if (restriction_is_or_clause(rinfo))
2001 : 5404 : *joinorclauses = lappend(*joinorclauses, rinfo);
2002 : : else
1889 2003 : 42512 : match_clause_to_index(root, rinfo, index, clauseset);
2004 : : }
4461 2005 : 296906 : }
2006 : :
2007 : : /*
2008 : : * match_eclass_clauses_to_index
2009 : : * Identify EquivalenceClass join clauses for the rel that match the index.
2010 : : * Matching clauses are added to *clauseset.
2011 : : */
2012 : : static void
2013 : 296906 : match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index,
2014 : : IndexClauseSet *clauseset)
2015 : : {
2016 : : int indexcol;
2017 : :
2018 : : /* No work if rel is not in any such ECs */
2019 [ + + ]: 296906 : if (!index->rel->has_eclass_joins)
2020 : 181816 : return;
2021 : :
2199 teodor@sigaev.ru 2022 [ + + ]: 295034 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2023 : : {
2024 : : ec_member_matches_arg arg;
2025 : : List *clauses;
2026 : :
2027 : : /* Generate clauses, skipping any that join to lateral_referencers */
4042 tgl@sss.pgh.pa.us 2028 : 179944 : arg.index = index;
2029 : 179944 : arg.indexcol = indexcol;
2030 : 179944 : clauses = generate_implied_equalities_for_column(root,
2031 : : index->rel,
2032 : : ec_member_matches_indexcol,
2033 : : (void *) &arg,
2489 2034 : 179944 : index->rel->lateral_referencers);
2035 : :
2036 : : /*
2037 : : * We have to check whether the results actually do match the index,
2038 : : * since for non-btree indexes the EC's equality operators might not
2039 : : * be in the index opclass (cf ec_member_matches_indexcol).
2040 : : */
1889 2041 : 179944 : match_clauses_to_index(root, clauses, index, clauseset);
2042 : : }
2043 : : }
2044 : :
2045 : : /*
2046 : : * match_clauses_to_index
2047 : : * Perform match_clause_to_index() for each clause in a list.
2048 : : * Matching clauses are added to *clauseset.
2049 : : */
2050 : : static void
2051 : 495834 : match_clauses_to_index(PlannerInfo *root,
2052 : : List *clauses,
2053 : : IndexOptInfo *index,
2054 : : IndexClauseSet *clauseset)
2055 : : {
2056 : : ListCell *lc;
2057 : :
4461 2058 [ + + + + : 900451 : foreach(lc, clauses)
+ + ]
2059 : : {
2561 2060 : 404617 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
2061 : :
1889 2062 : 404617 : match_clause_to_index(root, rinfo, index, clauseset);
2063 : : }
4461 2064 : 495834 : }
2065 : :
2066 : : /*
2067 : : * match_clause_to_index
2068 : : * Test whether a qual clause can be used with an index.
2069 : : *
2070 : : * If the clause is usable, add an IndexClause entry for it to the appropriate
2071 : : * list in *clauseset. (*clauseset must be initialized to zeroes before first
2072 : : * call.)
2073 : : *
2074 : : * Note: in some circumstances we may find the same RestrictInfos coming from
2075 : : * multiple places. Defend against redundant outputs by refusing to add a
2076 : : * clause twice (pointer equality should be a good enough check for this).
2077 : : *
2078 : : * Note: it's possible that a badly-defined index could have multiple matching
2079 : : * columns. We always select the first match if so; this avoids scenarios
2080 : : * wherein we get an inflated idea of the index's selectivity by using the
2081 : : * same clause multiple times with different index columns.
2082 : : */
2083 : : static void
1889 2084 : 447129 : match_clause_to_index(PlannerInfo *root,
2085 : : RestrictInfo *rinfo,
2086 : : IndexOptInfo *index,
2087 : : IndexClauseSet *clauseset)
2088 : : {
2089 : : int indexcol;
2090 : :
2091 : : /*
2092 : : * Never match pseudoconstants to indexes. (Normally a match could not
2093 : : * happen anyway, since a pseudoconstant clause couldn't contain a Var,
2094 : : * but what if someone builds an expression index on a constant? It's not
2095 : : * totally unreasonable to do so with a partial index, either.)
2096 : : */
2643 2097 [ + + ]: 447129 : if (rinfo->pseudoconstant)
2098 : 5708 : return;
2099 : :
2100 : : /*
2101 : : * If clause can't be used as an indexqual because it must wait till after
2102 : : * some lower-security-level restriction clause, reject it.
2103 : : */
2104 [ + + ]: 441421 : if (!restriction_is_securely_promotable(rinfo, index->rel))
2105 : 237 : return;
2106 : :
2107 : : /* OK, check each index key column for a match */
2198 teodor@sigaev.ru 2108 [ + + ]: 977496 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2109 : : {
2110 : : IndexClause *iclause;
2111 : : ListCell *lc;
2112 : :
2113 : : /* Ignore duplicates */
1891 tgl@sss.pgh.pa.us 2114 [ + + + + : 730252 : foreach(lc, clauseset->indexclauses[indexcol])
+ + ]
2115 : : {
597 drowley@postgresql.o 2116 : 28936 : iclause = (IndexClause *) lfirst(lc);
2117 : :
1891 tgl@sss.pgh.pa.us 2118 [ - + ]: 28936 : if (iclause->rinfo == rinfo)
1891 tgl@sss.pgh.pa.us 2119 :UBC 0 : return;
2120 : : }
2121 : :
2122 : : /* OK, try to match the clause to the index column */
1889 tgl@sss.pgh.pa.us 2123 :CBC 701316 : iclause = match_clause_to_indexcol(root,
2124 : : rinfo,
2125 : : indexcol,
2126 : : index);
2127 [ + + ]: 701316 : if (iclause)
2128 : : {
2129 : : /* Success, so record it */
4461 2130 : 165004 : clauseset->indexclauses[indexcol] =
1891 2131 : 165004 : lappend(clauseset->indexclauses[indexcol], iclause);
4461 2132 : 165004 : clauseset->nonempty = true;
4495 2133 : 165004 : return;
2134 : : }
2135 : : }
2136 : : }
2137 : :
2138 : : /*
2139 : : * match_clause_to_indexcol()
2140 : : * Determine whether a restriction clause matches a column of an index,
2141 : : * and if so, build an IndexClause node describing the details.
2142 : : *
2143 : : * To match an index normally, an operator clause:
2144 : : *
2145 : : * (1) must be in the form (indexkey op const) or (const op indexkey);
2146 : : * and
2147 : : * (2) must contain an operator which is in the index's operator family
2148 : : * for this column; and
2149 : : * (3) must match the collation of the index, if collation is relevant.
2150 : : *
2151 : : * Our definition of "const" is exceedingly liberal: we allow anything that
2152 : : * doesn't involve a volatile function or a Var of the index's relation.
2153 : : * In particular, Vars belonging to other relations of the query are
2154 : : * accepted here, since a clause of that form can be used in a
2155 : : * parameterized indexscan. It's the responsibility of higher code levels
2156 : : * to manage restriction and join clauses appropriately.
2157 : : *
2158 : : * Note: we do need to check for Vars of the index's relation on the
2159 : : * "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
2160 : : * are not processable by a parameterized indexscan on a.f1, whereas
2161 : : * something like (a.f1 OP (b.f2 OP c.f3)) is.
2162 : : *
2163 : : * Presently, the executor can only deal with indexquals that have the
2164 : : * indexkey on the left, so we can only use clauses that have the indexkey
2165 : : * on the right if we can commute the clause to put the key on the left.
2166 : : * We handle that by generating an IndexClause with the correctly-commuted
2167 : : * opclause as a derived indexqual.
2168 : : *
2169 : : * If the index has a collation, the clause must have the same collation.
2170 : : * For collation-less indexes, we assume it doesn't matter; this is
2171 : : * necessary for cases like "hstore ? text", wherein hstore's operators
2172 : : * don't care about collation but the clause will get marked with a
2173 : : * collation anyway because of the text argument. (This logic is
2174 : : * embodied in the macro IndexCollMatchesExprColl.)
2175 : : *
2176 : : * It is also possible to match RowCompareExpr clauses to indexes (but
2177 : : * currently, only btree indexes handle this).
2178 : : *
2179 : : * It is also possible to match ScalarArrayOpExpr clauses to indexes, when
2180 : : * the clause is of the form "indexkey op ANY (arrayconst)".
2181 : : *
2182 : : * For boolean indexes, it is also possible to match the clause directly
2183 : : * to the indexkey; or perhaps the clause is (NOT indexkey).
2184 : : *
2185 : : * And, last but not least, some operators and functions can be processed
2186 : : * to derive (typically lossy) indexquals from a clause that isn't in
2187 : : * itself indexable. If we see that any operand of an OpExpr or FuncExpr
2188 : : * matches the index key, and the function has a planner support function
2189 : : * attached to it, we'll invoke the support function to see if such an
2190 : : * indexqual can be built.
2191 : : *
2192 : : * 'rinfo' is the clause to be tested (as a RestrictInfo node).
2193 : : * 'indexcol' is a column number of 'index' (counting from 0).
2194 : : * 'index' is the index of interest.
2195 : : *
2196 : : * Returns an IndexClause if the clause can be used with this index key,
2197 : : * or NULL if not.
2198 : : *
2199 : : * NOTE: returns NULL if clause is an OR or AND clause; it is the
2200 : : * responsibility of higher-level routines to cope with those.
2201 : : */
2202 : : static IndexClause *
1889 2203 : 701316 : match_clause_to_indexcol(PlannerInfo *root,
2204 : : RestrictInfo *rinfo,
2205 : : int indexcol,
2206 : : IndexOptInfo *index)
2207 : : {
2208 : : IndexClause *iclause;
7406 2209 : 701316 : Expr *clause = rinfo->clause;
2210 : : Oid opfamily;
2211 : :
2194 teodor@sigaev.ru 2212 [ - + ]: 701316 : Assert(indexcol < index->nkeycolumns);
2213 : :
2214 : : /*
2215 : : * Historically this code has coped with NULL clauses. That's probably
2216 : : * not possible anymore, but we might as well continue to cope.
2217 : : */
1889 tgl@sss.pgh.pa.us 2218 [ - + ]: 701316 : if (clause == NULL)
1889 tgl@sss.pgh.pa.us 2219 :UBC 0 : return NULL;
2220 : :
2221 : : /* First check for boolean-index cases. */
1889 tgl@sss.pgh.pa.us 2222 :CBC 701316 : opfamily = index->opfamily[indexcol];
6322 2223 [ + + ]: 701316 : if (IsBooleanOpfamily(opfamily))
2224 : : {
1179 2225 : 97 : iclause = match_boolean_index_clause(root, rinfo, indexcol, index);
1889 2226 [ + + ]: 97 : if (iclause)
2227 : 48 : return iclause;
2228 : : }
2229 : :
2230 : : /*
2231 : : * Clause must be an opclause, funcclause, ScalarArrayOpExpr, or
2232 : : * RowCompareExpr. Or, if the index supports it, we can handle IS
2233 : : * NULL/NOT NULL clauses.
2234 : : */
2235 [ + + ]: 701268 : if (IsA(clause, OpExpr))
2236 : : {
2237 : 587080 : return match_opclause_to_indexcol(root, rinfo, indexcol, index);
2238 : : }
2239 [ + + ]: 114188 : else if (IsA(clause, FuncExpr))
2240 : : {
2241 : 12773 : return match_funcclause_to_indexcol(root, rinfo, indexcol, index);
2242 : : }
2243 [ + + ]: 101415 : else if (IsA(clause, ScalarArrayOpExpr))
2244 : : {
1179 2245 : 31184 : return match_saopclause_to_indexcol(root, rinfo, indexcol, index);
2246 : : }
1889 2247 [ + + ]: 70231 : else if (IsA(clause, RowCompareExpr))
2248 : : {
1179 2249 : 144 : return match_rowcompare_to_indexcol(root, rinfo, indexcol, index);
2250 : : }
6218 2251 [ + + + + ]: 70087 : else if (index->amsearchnulls && IsA(clause, NullTest))
2252 : : {
5995 bruce@momjian.us 2253 : 7924 : NullTest *nt = (NullTest *) clause;
2254 : :
5217 tgl@sss.pgh.pa.us 2255 [ + - + + ]: 15848 : if (!nt->argisrow &&
2256 : 7924 : match_index_to_operand((Node *) nt->arg, indexcol, index))
2257 : : {
1889 2258 : 682 : iclause = makeNode(IndexClause);
2259 : 682 : iclause->rinfo = rinfo;
1886 2260 : 682 : iclause->indexquals = list_make1(rinfo);
1889 2261 : 682 : iclause->lossy = false;
2262 : 682 : iclause->indexcol = indexcol;
2263 : 682 : iclause->indexcols = NIL;
2264 : 682 : return iclause;
2265 : : }
2266 : : }
2267 : :
2268 : 69405 : return NULL;
2269 : : }
2270 : :
2271 : : /*
2272 : : * IsBooleanOpfamily
2273 : : * Detect whether an opfamily supports boolean equality as an operator.
2274 : : *
2275 : : * If the opfamily OID is in the range of built-in objects, we can rely
2276 : : * on hard-wired knowledge of which built-in opfamilies support this.
2277 : : * For extension opfamilies, there's no choice but to do a catcache lookup.
2278 : : */
2279 : : static bool
590 2280 : 953382 : IsBooleanOpfamily(Oid opfamily)
2281 : : {
2282 [ + + ]: 953382 : if (opfamily < FirstNormalObjectId)
2283 [ + + - + ]: 951785 : return IsBuiltinBooleanOpfamily(opfamily);
2284 : : else
2285 : 1597 : return op_in_opfamily(BooleanEqualOperator, opfamily);
2286 : : }
2287 : :
2288 : : /*
2289 : : * match_boolean_index_clause
2290 : : * Recognize restriction clauses that can be matched to a boolean index.
2291 : : *
2292 : : * The idea here is that, for an index on a boolean column that supports the
2293 : : * BooleanEqualOperator, we can transform a plain reference to the indexkey
2294 : : * into "indexkey = true", or "NOT indexkey" into "indexkey = false", etc,
2295 : : * so as to make the expression indexable using the index's "=" operator.
2296 : : * Since Postgres 8.1, we must do this because constant simplification does
2297 : : * the reverse transformation; without this code there'd be no way to use
2298 : : * such an index at all.
2299 : : *
2300 : : * This should be called only when IsBooleanOpfamily() recognizes the
2301 : : * index's operator family. We check to see if the clause matches the
2302 : : * index's key, and if so, build a suitable IndexClause.
2303 : : */
2304 : : static IndexClause *
1179 2305 : 169 : match_boolean_index_clause(PlannerInfo *root,
2306 : : RestrictInfo *rinfo,
2307 : : int indexcol,
2308 : : IndexOptInfo *index)
2309 : : {
1889 2310 : 169 : Node *clause = (Node *) rinfo->clause;
2311 : 169 : Expr *op = NULL;
2312 : :
2313 : : /* Direct match? */
2314 [ + + ]: 169 : if (match_index_to_operand(clause, indexcol, index))
2315 : : {
2316 : : /* convert to indexkey = TRUE */
2317 : 47 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2318 : : (Expr *) clause,
2319 : 47 : (Expr *) makeBoolConst(true, false),
2320 : : InvalidOid, InvalidOid);
2321 : : }
2322 : : /* NOT clause? */
2323 [ + + ]: 122 : else if (is_notclause(clause))
2324 : : {
2325 : 37 : Node *arg = (Node *) get_notclausearg((Expr *) clause);
2326 : :
2327 [ + - ]: 37 : if (match_index_to_operand(arg, indexcol, index))
2328 : : {
2329 : : /* convert to indexkey = FALSE */
2330 : 37 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2331 : : (Expr *) arg,
2332 : 37 : (Expr *) makeBoolConst(false, false),
2333 : : InvalidOid, InvalidOid);
2334 : : }
2335 : : }
2336 : :
2337 : : /*
2338 : : * Since we only consider clauses at top level of WHERE, we can convert
2339 : : * indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
2340 : : * different meaning for NULL isn't important.
2341 : : */
2342 [ + - + + ]: 85 : else if (clause && IsA(clause, BooleanTest))
2343 : : {
2344 : 18 : BooleanTest *btest = (BooleanTest *) clause;
2345 : 18 : Node *arg = (Node *) btest->arg;
2346 : :
2347 [ + + + - ]: 27 : if (btest->booltesttype == IS_TRUE &&
2348 : 9 : match_index_to_operand(arg, indexcol, index))
2349 : : {
2350 : : /* convert to indexkey = TRUE */
2351 : 9 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2352 : : (Expr *) arg,
2353 : 9 : (Expr *) makeBoolConst(true, false),
2354 : : InvalidOid, InvalidOid);
2355 : : }
2356 [ + - + - ]: 18 : else if (btest->booltesttype == IS_FALSE &&
2357 : 9 : match_index_to_operand(arg, indexcol, index))
2358 : : {
2359 : : /* convert to indexkey = FALSE */
2360 : 9 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2361 : : (Expr *) arg,
2362 : 9 : (Expr *) makeBoolConst(false, false),
2363 : : InvalidOid, InvalidOid);
2364 : : }
2365 : : }
2366 : :
2367 : : /*
2368 : : * If we successfully made an operator clause from the given qual, we must
2369 : : * wrap it in an IndexClause. It's not lossy.
2370 : : */
2371 [ + + ]: 169 : if (op)
2372 : : {
2373 : 102 : IndexClause *iclause = makeNode(IndexClause);
2374 : :
2375 : 102 : iclause->rinfo = rinfo;
1179 2376 : 102 : iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
1889 2377 : 102 : iclause->lossy = false;
2378 : 102 : iclause->indexcol = indexcol;
2379 : 102 : iclause->indexcols = NIL;
2380 : 102 : return iclause;
2381 : : }
2382 : :
2383 : 67 : return NULL;
2384 : : }
2385 : :
2386 : : /*
2387 : : * match_opclause_to_indexcol()
2388 : : * Handles the OpExpr case for match_clause_to_indexcol(),
2389 : : * which see for comments.
2390 : : */
2391 : : static IndexClause *
2392 : 587080 : match_opclause_to_indexcol(PlannerInfo *root,
2393 : : RestrictInfo *rinfo,
2394 : : int indexcol,
2395 : : IndexOptInfo *index)
2396 : : {
2397 : : IndexClause *iclause;
2398 : 587080 : OpExpr *clause = (OpExpr *) rinfo->clause;
2399 : : Node *leftop,
2400 : : *rightop;
2401 : : Oid expr_op;
2402 : : Oid expr_coll;
2403 : : Index index_relid;
2404 : : Oid opfamily;
2405 : : Oid idxcollation;
2406 : :
2407 : : /*
2408 : : * Only binary operators need apply. (In theory, a planner support
2409 : : * function could do something with a unary operator, but it seems
2410 : : * unlikely to be worth the cycles to check.)
2411 : : */
2412 [ - + ]: 587080 : if (list_length(clause->args) != 2)
1889 tgl@sss.pgh.pa.us 2413 :UBC 0 : return NULL;
2414 : :
1889 tgl@sss.pgh.pa.us 2415 :CBC 587080 : leftop = (Node *) linitial(clause->args);
2416 : 587080 : rightop = (Node *) lsecond(clause->args);
2417 : 587080 : expr_op = clause->opno;
2418 : 587080 : expr_coll = clause->inputcollid;
2419 : :
2420 : 587080 : index_relid = index->rel->relid;
2421 : 587080 : opfamily = index->opfamily[indexcol];
2422 : 587080 : idxcollation = index->indexcollations[indexcol];
2423 : :
2424 : : /*
2425 : : * Check for clauses of the form: (indexkey operator constant) or
2426 : : * (constant operator indexkey). See match_clause_to_indexcol's notes
2427 : : * about const-ness.
2428 : : *
2429 : : * Note that we don't ask the support function about clauses that don't
2430 : : * have one of these forms. Again, in principle it might be possible to
2431 : : * do something, but it seems unlikely to be worth the cycles to check.
2432 : : */
6958 2433 [ + + ]: 587080 : if (match_index_to_operand(leftop, indexcol, index) &&
1889 2434 [ + + ]: 138431 : !bms_is_member(index_relid, rinfo->right_relids) &&
6932 2435 [ + - ]: 138350 : !contain_volatile_functions(rightop))
2436 : : {
4581 2437 [ + + + + : 273643 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
+ + ]
1889 2438 : 135293 : op_in_opfamily(expr_op, opfamily))
2439 : : {
2440 : 131450 : iclause = makeNode(IndexClause);
2441 : 131450 : iclause->rinfo = rinfo;
1886 2442 : 131450 : iclause->indexquals = list_make1(rinfo);
1889 2443 : 131450 : iclause->lossy = false;
2444 : 131450 : iclause->indexcol = indexcol;
2445 : 131450 : iclause->indexcols = NIL;
2446 : 131450 : return iclause;
2447 : : }
2448 : :
2449 : : /*
2450 : : * If we didn't find a member of the index's opfamily, try the support
2451 : : * function for the operator's underlying function.
2452 : : */
2453 : 6900 : set_opfuncid(clause); /* make sure we have opfuncid */
2454 : 6900 : return get_index_clause_from_support(root,
2455 : : rinfo,
2456 : : clause->opfuncid,
2457 : : 0, /* indexarg on left */
2458 : : indexcol,
2459 : : index);
2460 : : }
2461 : :
2462 [ + + ]: 448730 : if (match_index_to_operand(rightop, indexcol, index) &&
2463 [ + + ]: 26847 : !bms_is_member(index_relid, rinfo->left_relids) &&
6932 2464 [ + - ]: 26814 : !contain_volatile_functions(leftop))
2465 : : {
1889 2466 [ + + + + ]: 26814 : if (IndexCollMatchesExprColl(idxcollation, expr_coll))
2467 : : {
2468 : 26808 : Oid comm_op = get_commutator(expr_op);
2469 : :
2470 [ + - + + ]: 53616 : if (OidIsValid(comm_op) &&
2471 : 26808 : op_in_opfamily(comm_op, opfamily))
2472 : : {
2473 : : RestrictInfo *commrinfo;
2474 : :
2475 : : /* Build a commuted OpExpr and RestrictInfo */
2476 : 26574 : commrinfo = commute_restrictinfo(rinfo, comm_op);
2477 : :
2478 : : /* Make an IndexClause showing that as a derived qual */
2479 : 26574 : iclause = makeNode(IndexClause);
2480 : 26574 : iclause->rinfo = rinfo;
2481 : 26574 : iclause->indexquals = list_make1(commrinfo);
2482 : 26574 : iclause->lossy = false;
2483 : 26574 : iclause->indexcol = indexcol;
2484 : 26574 : iclause->indexcols = NIL;
2485 : 26574 : return iclause;
2486 : : }
2487 : : }
2488 : :
2489 : : /*
2490 : : * If we didn't find a member of the index's opfamily, try the support
2491 : : * function for the operator's underlying function.
2492 : : */
2493 : 240 : set_opfuncid(clause); /* make sure we have opfuncid */
2494 : 240 : return get_index_clause_from_support(root,
2495 : : rinfo,
2496 : : clause->opfuncid,
2497 : : 1, /* indexarg on right */
2498 : : indexcol,
2499 : : index);
2500 : : }
2501 : :
2502 : 421916 : return NULL;
2503 : : }
2504 : :
2505 : : /*
2506 : : * match_funcclause_to_indexcol()
2507 : : * Handles the FuncExpr case for match_clause_to_indexcol(),
2508 : : * which see for comments.
2509 : : */
2510 : : static IndexClause *
2511 : 12773 : match_funcclause_to_indexcol(PlannerInfo *root,
2512 : : RestrictInfo *rinfo,
2513 : : int indexcol,
2514 : : IndexOptInfo *index)
2515 : : {
2516 : 12773 : FuncExpr *clause = (FuncExpr *) rinfo->clause;
2517 : : int indexarg;
2518 : : ListCell *lc;
2519 : :
2520 : : /*
2521 : : * We have no built-in intelligence about function clauses, but if there's
2522 : : * a planner support function, it might be able to do something. But, to
2523 : : * cut down on wasted planning cycles, only call the support function if
2524 : : * at least one argument matches the target index column.
2525 : : *
2526 : : * Note that we don't insist on the other arguments being pseudoconstants;
2527 : : * the support function has to check that. This is to allow cases where
2528 : : * only some of the other arguments need to be included in the indexqual.
2529 : : */
2530 : 12773 : indexarg = 0;
2531 [ + - + + : 26396 : foreach(lc, clause->args)
+ + ]
2532 : : {
2533 : 15924 : Node *op = (Node *) lfirst(lc);
2534 : :
2535 [ + + ]: 15924 : if (match_index_to_operand(op, indexcol, index))
2536 : : {
2537 : 2301 : return get_index_clause_from_support(root,
2538 : : rinfo,
2539 : : clause->funcid,
2540 : : indexarg,
2541 : : indexcol,
2542 : : index);
2543 : : }
2544 : :
2545 : 13623 : indexarg++;
2546 : : }
2547 : :
2548 : 10472 : return NULL;
2549 : : }
2550 : :
2551 : : /*
2552 : : * get_index_clause_from_support()
2553 : : * If the function has a planner support function, try to construct
2554 : : * an IndexClause using indexquals created by the support function.
2555 : : */
2556 : : static IndexClause *
2557 : 9441 : get_index_clause_from_support(PlannerInfo *root,
2558 : : RestrictInfo *rinfo,
2559 : : Oid funcid,
2560 : : int indexarg,
2561 : : int indexcol,
2562 : : IndexOptInfo *index)
2563 : : {
2564 : 9441 : Oid prosupport = get_func_support(funcid);
2565 : : SupportRequestIndexCondition req;
2566 : : List *sresult;
2567 : :
2568 [ + + ]: 9441 : if (!OidIsValid(prosupport))
2569 : 5620 : return NULL;
2570 : :
2571 : 3821 : req.type = T_SupportRequestIndexCondition;
2572 : 3821 : req.root = root;
2573 : 3821 : req.funcid = funcid;
2574 : 3821 : req.node = (Node *) rinfo->clause;
2575 : 3821 : req.indexarg = indexarg;
2576 : 3821 : req.index = index;
2577 : 3821 : req.indexcol = indexcol;
2578 : 3821 : req.opfamily = index->opfamily[indexcol];
2579 : 3821 : req.indexcollation = index->indexcollations[indexcol];
2580 : :
2581 : 3821 : req.lossy = true; /* default assumption */
2582 : :
2583 : : sresult = (List *)
2584 : 3821 : DatumGetPointer(OidFunctionCall1(prosupport,
2585 : : PointerGetDatum(&req)));
2586 : :
2587 [ + + ]: 3821 : if (sresult != NIL)
2588 : : {
2589 : 3580 : IndexClause *iclause = makeNode(IndexClause);
2590 : 3580 : List *indexquals = NIL;
2591 : : ListCell *lc;
2592 : :
2593 : : /*
2594 : : * The support function API says it should just give back bare
2595 : : * clauses, so here we must wrap each one in a RestrictInfo.
2596 : : */
2597 [ + - + + : 7798 : foreach(lc, sresult)
+ + ]
2598 : : {
2599 : 4218 : Expr *clause = (Expr *) lfirst(lc);
2600 : :
1179 2601 : 4218 : indexquals = lappend(indexquals,
2602 : 4218 : make_simple_restrictinfo(root, clause));
2603 : : }
2604 : :
1889 2605 : 3580 : iclause->rinfo = rinfo;
2606 : 3580 : iclause->indexquals = indexquals;
2607 : 3580 : iclause->lossy = req.lossy;
2608 : 3580 : iclause->indexcol = indexcol;
2609 : 3580 : iclause->indexcols = NIL;
2610 : :
2611 : 3580 : return iclause;
2612 : : }
2613 : :
2614 : 241 : return NULL;
2615 : : }
2616 : :
2617 : : /*
2618 : : * match_saopclause_to_indexcol()
2619 : : * Handles the ScalarArrayOpExpr case for match_clause_to_indexcol(),
2620 : : * which see for comments.
2621 : : */
2622 : : static IndexClause *
1179 2623 : 31184 : match_saopclause_to_indexcol(PlannerInfo *root,
2624 : : RestrictInfo *rinfo,
2625 : : int indexcol,
2626 : : IndexOptInfo *index)
2627 : : {
1889 2628 : 31184 : ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
2629 : : Node *leftop,
2630 : : *rightop;
2631 : : Relids right_relids;
2632 : : Oid expr_op;
2633 : : Oid expr_coll;
2634 : : Index index_relid;
2635 : : Oid opfamily;
2636 : : Oid idxcollation;
2637 : :
2638 : : /* We only accept ANY clauses, not ALL */
2639 [ + + ]: 31184 : if (!saop->useOr)
2640 : 4133 : return NULL;
2641 : 27051 : leftop = (Node *) linitial(saop->args);
2642 : 27051 : rightop = (Node *) lsecond(saop->args);
1179 2643 : 27051 : right_relids = pull_varnos(root, rightop);
1889 2644 : 27051 : expr_op = saop->opno;
2645 : 27051 : expr_coll = saop->inputcollid;
2646 : :
2647 : 27051 : index_relid = index->rel->relid;
2648 : 27051 : opfamily = index->opfamily[indexcol];
2649 : 27051 : idxcollation = index->indexcollations[indexcol];
2650 : :
2651 : : /*
2652 : : * We must have indexkey on the left and a pseudo-constant array argument.
2653 : : */
2654 [ + + ]: 27051 : if (match_index_to_operand(leftop, indexcol, index) &&
2655 [ + - ]: 2634 : !bms_is_member(index_relid, right_relids) &&
2656 [ + - ]: 2634 : !contain_volatile_functions(rightop))
2657 : : {
2658 [ + + + + : 5265 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
+ + ]
2659 : 2631 : op_in_opfamily(expr_op, opfamily))
2660 : : {
2661 : 2625 : IndexClause *iclause = makeNode(IndexClause);
2662 : :
2663 : 2625 : iclause->rinfo = rinfo;
1886 2664 : 2625 : iclause->indexquals = list_make1(rinfo);
1889 2665 : 2625 : iclause->lossy = false;
2666 : 2625 : iclause->indexcol = indexcol;
2667 : 2625 : iclause->indexcols = NIL;
2668 : 2625 : return iclause;
2669 : : }
2670 : :
2671 : : /*
2672 : : * We do not currently ask support functions about ScalarArrayOpExprs,
2673 : : * though in principle we could.
2674 : : */
2675 : : }
2676 : :
2677 : 24426 : return NULL;
2678 : : }
2679 : :
2680 : : /*
2681 : : * match_rowcompare_to_indexcol()
2682 : : * Handles the RowCompareExpr case for match_clause_to_indexcol(),
2683 : : * which see for comments.
2684 : : *
2685 : : * In this routine we check whether the first column of the row comparison
2686 : : * matches the target index column. This is sufficient to guarantee that some
2687 : : * index condition can be constructed from the RowCompareExpr --- the rest
2688 : : * is handled by expand_indexqual_rowcompare().
2689 : : */
2690 : : static IndexClause *
1179 2691 : 144 : match_rowcompare_to_indexcol(PlannerInfo *root,
2692 : : RestrictInfo *rinfo,
2693 : : int indexcol,
2694 : : IndexOptInfo *index)
2695 : : {
1889 2696 : 144 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
2697 : : Index index_relid;
2698 : : Oid opfamily;
2699 : : Oid idxcollation;
2700 : : Node *leftop,
2701 : : *rightop;
2702 : : bool var_on_left;
2703 : : Oid expr_op;
2704 : : Oid expr_coll;
2705 : :
2706 : : /* Forget it if we're not dealing with a btree index */
6654 2707 [ - + ]: 144 : if (index->relam != BTREE_AM_OID)
1889 tgl@sss.pgh.pa.us 2708 :UBC 0 : return NULL;
2709 : :
1889 tgl@sss.pgh.pa.us 2710 :CBC 144 : index_relid = index->rel->relid;
2711 : 144 : opfamily = index->opfamily[indexcol];
2712 : 144 : idxcollation = index->indexcollations[indexcol];
2713 : :
2714 : : /*
2715 : : * We could do the matching on the basis of insisting that the opfamily
2716 : : * shown in the RowCompareExpr be the same as the index column's opfamily,
2717 : : * but that could fail in the presence of reverse-sort opfamilies: it'd be
2718 : : * a matter of chance whether RowCompareExpr had picked the forward or
2719 : : * reverse-sort family. So look only at the operator, and match if it is
2720 : : * a member of the index's opfamily (after commutation, if the indexkey is
2721 : : * on the right). We'll worry later about whether any additional
2722 : : * operators are matchable to the index.
2723 : : */
6654 2724 : 144 : leftop = (Node *) linitial(clause->largs);
2725 : 144 : rightop = (Node *) linitial(clause->rargs);
2726 : 144 : expr_op = linitial_oid(clause->opnos);
4755 2727 : 144 : expr_coll = linitial_oid(clause->inputcollids);
2728 : :
2729 : : /* Collations must match, if relevant */
4581 2730 [ + + - + ]: 144 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
1889 tgl@sss.pgh.pa.us 2731 :UBC 0 : return NULL;
2732 : :
2733 : : /*
2734 : : * These syntactic tests are the same as in match_opclause_to_indexcol()
2735 : : */
6654 tgl@sss.pgh.pa.us 2736 [ + + ]:CBC 144 : if (match_index_to_operand(leftop, indexcol, index) &&
1179 2737 [ + - ]: 33 : !bms_is_member(index_relid, pull_varnos(root, rightop)) &&
6654 2738 [ + - ]: 33 : !contain_volatile_functions(rightop))
2739 : : {
2740 : : /* OK, indexkey is on left */
1889 2741 : 33 : var_on_left = true;
2742 : : }
6654 2743 [ + + ]: 111 : else if (match_index_to_operand(rightop, indexcol, index) &&
1179 2744 [ + - ]: 12 : !bms_is_member(index_relid, pull_varnos(root, leftop)) &&
6654 2745 [ + - ]: 12 : !contain_volatile_functions(leftop))
2746 : : {
2747 : : /* indexkey is on right, so commute the operator */
2748 : 12 : expr_op = get_commutator(expr_op);
2749 [ - + ]: 12 : if (expr_op == InvalidOid)
1889 tgl@sss.pgh.pa.us 2750 :UBC 0 : return NULL;
1889 tgl@sss.pgh.pa.us 2751 :CBC 12 : var_on_left = false;
2752 : : }
2753 : : else
2754 : 99 : return NULL;
2755 : :
2756 : : /* We're good if the operator is the right type of opfamily member */
6322 2757 [ + - ]: 45 : switch (get_op_opfamily_strategy(expr_op, opfamily))
2758 : : {
6654 2759 : 45 : case BTLessStrategyNumber:
2760 : : case BTLessEqualStrategyNumber:
2761 : : case BTGreaterEqualStrategyNumber:
2762 : : case BTGreaterStrategyNumber:
1179 2763 : 45 : return expand_indexqual_rowcompare(root,
2764 : : rinfo,
2765 : : indexcol,
2766 : : index,
2767 : : expr_op,
2768 : : var_on_left);
2769 : : }
2770 : :
1889 tgl@sss.pgh.pa.us 2771 :UBC 0 : return NULL;
2772 : : }
2773 : :
2774 : : /*
2775 : : * expand_indexqual_rowcompare --- expand a single indexqual condition
2776 : : * that is a RowCompareExpr
2777 : : *
2778 : : * It's already known that the first column of the row comparison matches
2779 : : * the specified column of the index. We can use additional columns of the
2780 : : * row comparison as index qualifications, so long as they match the index
2781 : : * in the "same direction", ie, the indexkeys are all on the same side of the
2782 : : * clause and the operators are all the same-type members of the opfamilies.
2783 : : *
2784 : : * If all the columns of the RowCompareExpr match in this way, we just use it
2785 : : * as-is, except for possibly commuting it to put the indexkeys on the left.
2786 : : *
2787 : : * Otherwise, we build a shortened RowCompareExpr (if more than one
2788 : : * column matches) or a simple OpExpr (if the first-column match is all
2789 : : * there is). In these cases the modified clause is always "<=" or ">="
2790 : : * even when the original was "<" or ">" --- this is necessary to match all
2791 : : * the rows that could match the original. (We are building a lossy version
2792 : : * of the row comparison when we do this, so we set lossy = true.)
2793 : : *
2794 : : * Note: this is really just the last half of match_rowcompare_to_indexcol,
2795 : : * but we split it out for comprehensibility.
2796 : : */
2797 : : static IndexClause *
1179 tgl@sss.pgh.pa.us 2798 :CBC 45 : expand_indexqual_rowcompare(PlannerInfo *root,
2799 : : RestrictInfo *rinfo,
2800 : : int indexcol,
2801 : : IndexOptInfo *index,
2802 : : Oid expr_op,
2803 : : bool var_on_left)
2804 : : {
1889 2805 : 45 : IndexClause *iclause = makeNode(IndexClause);
2806 : 45 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
2807 : : int op_strategy;
2808 : : Oid op_lefttype;
2809 : : Oid op_righttype;
2810 : : int matching_cols;
2811 : : List *expr_ops;
2812 : : List *opfamilies;
2813 : : List *lefttypes;
2814 : : List *righttypes;
2815 : : List *new_ops;
2816 : : List *var_args;
2817 : : List *non_var_args;
2818 : :
2819 : 45 : iclause->rinfo = rinfo;
2820 : 45 : iclause->indexcol = indexcol;
2821 : :
2822 [ + + ]: 45 : if (var_on_left)
2823 : : {
2824 : 33 : var_args = clause->largs;
2825 : 33 : non_var_args = clause->rargs;
2826 : : }
2827 : : else
2828 : : {
2829 : 12 : var_args = clause->rargs;
2830 : 12 : non_var_args = clause->largs;
2831 : : }
2832 : :
2833 : 45 : get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
2834 : : &op_strategy,
2835 : : &op_lefttype,
2836 : : &op_righttype);
2837 : :
2838 : : /* Initialize returned list of which index columns are used */
2839 : 45 : iclause->indexcols = list_make1_int(indexcol);
2840 : :
2841 : : /* Build lists of ops, opfamilies and operator datatypes in case needed */
2842 : 45 : expr_ops = list_make1_oid(expr_op);
2843 : 45 : opfamilies = list_make1_oid(index->opfamily[indexcol]);
2844 : 45 : lefttypes = list_make1_oid(op_lefttype);
2845 : 45 : righttypes = list_make1_oid(op_righttype);
2846 : :
2847 : : /*
2848 : : * See how many of the remaining columns match some index column in the
2849 : : * same way. As in match_clause_to_indexcol(), the "other" side of any
2850 : : * potential index condition is OK as long as it doesn't use Vars from the
2851 : : * indexed relation.
2852 : : */
2853 : 45 : matching_cols = 1;
2854 : :
1735 2855 [ + + ]: 81 : while (matching_cols < list_length(var_args))
2856 : : {
2857 : 63 : Node *varop = (Node *) list_nth(var_args, matching_cols);
2858 : 63 : Node *constop = (Node *) list_nth(non_var_args, matching_cols);
2859 : : int i;
2860 : :
2861 : 63 : expr_op = list_nth_oid(clause->opnos, matching_cols);
1889 2862 [ + + ]: 63 : if (!var_on_left)
2863 : : {
2864 : : /* indexkey is on right, so commute the operator */
2865 : 12 : expr_op = get_commutator(expr_op);
2866 [ - + ]: 12 : if (expr_op == InvalidOid)
1889 tgl@sss.pgh.pa.us 2867 :UBC 0 : break; /* operator is not usable */
2868 : : }
1179 tgl@sss.pgh.pa.us 2869 [ - + ]:CBC 63 : if (bms_is_member(index->rel->relid, pull_varnos(root, constop)))
1889 tgl@sss.pgh.pa.us 2870 :UBC 0 : break; /* no good, Var on wrong side */
1889 tgl@sss.pgh.pa.us 2871 [ - + ]:CBC 63 : if (contain_volatile_functions(constop))
1889 tgl@sss.pgh.pa.us 2872 :UBC 0 : break; /* no good, volatile comparison value */
2873 : :
2874 : : /*
2875 : : * The Var side can match any key column of the index.
2876 : : */
1889 tgl@sss.pgh.pa.us 2877 [ + + ]:CBC 150 : for (i = 0; i < index->nkeycolumns; i++)
2878 : : {
2879 [ + + ]: 123 : if (match_index_to_operand(varop, i, index) &&
2880 : 36 : get_op_opfamily_strategy(expr_op,
2881 [ + - ]: 36 : index->opfamily[i]) == op_strategy &&
2882 [ + + - + ]: 36 : IndexCollMatchesExprColl(index->indexcollations[i],
2883 : : list_nth_oid(clause->inputcollids,
2884 : : matching_cols)))
2885 : : break;
2886 : : }
2887 [ + + ]: 63 : if (i >= index->nkeycolumns)
2888 : 27 : break; /* no match found */
2889 : :
2890 : : /* Add column number to returned list */
2891 : 36 : iclause->indexcols = lappend_int(iclause->indexcols, i);
2892 : :
2893 : : /* Add operator info to lists */
2894 : 36 : get_op_opfamily_properties(expr_op, index->opfamily[i], false,
2895 : : &op_strategy,
2896 : : &op_lefttype,
2897 : : &op_righttype);
2898 : 36 : expr_ops = lappend_oid(expr_ops, expr_op);
2899 : 36 : opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
2900 : 36 : lefttypes = lappend_oid(lefttypes, op_lefttype);
2901 : 36 : righttypes = lappend_oid(righttypes, op_righttype);
2902 : :
2903 : : /* This column matches, keep scanning */
2904 : 36 : matching_cols++;
2905 : : }
2906 : :
2907 : : /* Result is non-lossy if all columns are usable as index quals */
2908 : 45 : iclause->lossy = (matching_cols != list_length(clause->opnos));
2909 : :
2910 : : /*
2911 : : * We can use rinfo->clause as-is if we have var on left and it's all
2912 : : * usable as index quals.
2913 : : */
2914 [ + + + + ]: 45 : if (var_on_left && !iclause->lossy)
1886 2915 : 12 : iclause->indexquals = list_make1(rinfo);
2916 : : else
2917 : : {
2918 : : /*
2919 : : * We have to generate a modified rowcompare (possibly just one
2920 : : * OpExpr). The painful part of this is changing < to <= or > to >=,
2921 : : * so deal with that first.
2922 : : */
1889 2923 [ + + ]: 33 : if (!iclause->lossy)
2924 : : {
2925 : : /* very easy, just use the commuted operators */
2926 : 6 : new_ops = expr_ops;
2927 : : }
2928 [ + - ]: 27 : else if (op_strategy == BTLessEqualStrategyNumber ||
2929 [ - + ]: 27 : op_strategy == BTGreaterEqualStrategyNumber)
2930 : : {
2931 : : /* easy, just use the same (possibly commuted) operators */
1889 tgl@sss.pgh.pa.us 2932 :UBC 0 : new_ops = list_truncate(expr_ops, matching_cols);
2933 : : }
2934 : : else
2935 : : {
2936 : : ListCell *opfamilies_cell;
2937 : : ListCell *lefttypes_cell;
2938 : : ListCell *righttypes_cell;
2939 : :
1889 tgl@sss.pgh.pa.us 2940 [ + + ]:CBC 27 : if (op_strategy == BTLessStrategyNumber)
2941 : 15 : op_strategy = BTLessEqualStrategyNumber;
2942 [ + - ]: 12 : else if (op_strategy == BTGreaterStrategyNumber)
2943 : 12 : op_strategy = BTGreaterEqualStrategyNumber;
2944 : : else
1889 tgl@sss.pgh.pa.us 2945 [ # # ]:UBC 0 : elog(ERROR, "unexpected strategy number %d", op_strategy);
1889 tgl@sss.pgh.pa.us 2946 :CBC 27 : new_ops = NIL;
2947 [ + - + + : 72 : forthree(opfamilies_cell, opfamilies,
+ - + + +
- + + + +
+ - + - +
+ ]
2948 : : lefttypes_cell, lefttypes,
2949 : : righttypes_cell, righttypes)
2950 : : {
2951 : 45 : Oid opfam = lfirst_oid(opfamilies_cell);
2952 : 45 : Oid lefttype = lfirst_oid(lefttypes_cell);
2953 : 45 : Oid righttype = lfirst_oid(righttypes_cell);
2954 : :
2955 : 45 : expr_op = get_opfamily_member(opfam, lefttype, righttype,
2956 : : op_strategy);
2957 [ - + ]: 45 : if (!OidIsValid(expr_op)) /* should not happen */
1889 tgl@sss.pgh.pa.us 2958 [ # # ]:UBC 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
2959 : : op_strategy, lefttype, righttype, opfam);
1889 tgl@sss.pgh.pa.us 2960 :CBC 45 : new_ops = lappend_oid(new_ops, expr_op);
2961 : : }
2962 : : }
2963 : :
2964 : : /* If we have more than one matching col, create a subset rowcompare */
2965 [ + + ]: 33 : if (matching_cols > 1)
2966 : : {
2967 : 24 : RowCompareExpr *rc = makeNode(RowCompareExpr);
2968 : :
2969 : 24 : rc->rctype = (RowCompareType) op_strategy;
2970 : 24 : rc->opnos = new_ops;
641 drowley@postgresql.o 2971 : 24 : rc->opfamilies = list_copy_head(clause->opfamilies,
2972 : : matching_cols);
2973 : 24 : rc->inputcollids = list_copy_head(clause->inputcollids,
2974 : : matching_cols);
2975 : 24 : rc->largs = list_copy_head(var_args, matching_cols);
2976 : 24 : rc->rargs = list_copy_head(non_var_args, matching_cols);
1179 tgl@sss.pgh.pa.us 2977 : 24 : iclause->indexquals = list_make1(make_simple_restrictinfo(root,
2978 : : (Expr *) rc));
2979 : : }
2980 : : else
2981 : : {
2982 : : Expr *op;
2983 : :
2984 : : /* We don't report an index column list in this case */
1889 2985 : 9 : iclause->indexcols = NIL;
2986 : :
2987 : 9 : op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
2988 : 9 : copyObject(linitial(var_args)),
2989 : 9 : copyObject(linitial(non_var_args)),
2990 : : InvalidOid,
2991 : 9 : linitial_oid(clause->inputcollids));
1179 2992 : 9 : iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
2993 : : }
2994 : : }
2995 : :
1889 2996 : 45 : return iclause;
2997 : : }
2998 : :
2999 : :
3000 : : /****************************************************************************
3001 : : * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3002 : : ****************************************************************************/
3003 : :
3004 : : /*
3005 : : * match_pathkeys_to_index
3006 : : * For the given 'index' and 'pathkeys', output a list of suitable ORDER
3007 : : * BY expressions, each of the form "indexedcol operator pseudoconstant",
3008 : : * along with an integer list of the index column numbers (zero based)
3009 : : * that each clause would be used with.
3010 : : *
3011 : : * This attempts to find an ORDER BY and index column number for all items in
3012 : : * the pathkey list, however, if we're unable to match any given pathkey to an
3013 : : * index column, we return just the ones matched by the function so far. This
3014 : : * allows callers who are interested in partial matches to get them. Callers
3015 : : * can determine a partial match vs a full match by checking the outputted
3016 : : * list lengths. A full match will have one item in the output lists for each
3017 : : * item in the given 'pathkeys' list.
3018 : : */
3019 : : static void
4495 3020 : 428 : match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3021 : : List **orderby_clauses_p,
3022 : : List **clause_columns_p)
3023 : : {
3024 : : ListCell *lc1;
3025 : :
4326 bruce@momjian.us 3026 : 428 : *orderby_clauses_p = NIL; /* set default results */
4495 tgl@sss.pgh.pa.us 3027 : 428 : *clause_columns_p = NIL;
3028 : :
3029 : : /* Only indexes with the amcanorderbyop property are interesting here */
4882 3030 [ - + ]: 428 : if (!index->amcanorderbyop)
4495 tgl@sss.pgh.pa.us 3031 :UBC 0 : return;
3032 : :
4882 tgl@sss.pgh.pa.us 3033 [ + + + + :CBC 665 : foreach(lc1, pathkeys)
+ + ]
3034 : : {
4753 bruce@momjian.us 3035 : 431 : PathKey *pathkey = (PathKey *) lfirst(lc1);
4882 tgl@sss.pgh.pa.us 3036 : 431 : bool found = false;
3037 : : ListCell *lc2;
3038 : :
3039 : :
3040 : : /* Pathkey must request default sort order for the target opfamily */
3041 [ + + ]: 431 : if (pathkey->pk_strategy != BTLessStrategyNumber ||
3042 [ - + ]: 414 : pathkey->pk_nulls_first)
4495 3043 : 194 : return;
3044 : :
3045 : : /* If eclass is volatile, no hope of using an indexscan */
4882 3046 [ - + ]: 414 : if (pathkey->pk_eclass->ec_has_volatile)
4495 tgl@sss.pgh.pa.us 3047 :UBC 0 : return;
3048 : :
3049 : : /*
3050 : : * Try to match eclass member expression(s) to index. Note that child
3051 : : * EC members are considered, but only when they belong to the target
3052 : : * relation. (Unlike regular members, the same expression could be a
3053 : : * child member of more than one EC. Therefore, the same index could
3054 : : * be considered to match more than one pathkey list, which is OK
3055 : : * here. See also get_eclass_for_sort_expr.)
3056 : : */
4882 tgl@sss.pgh.pa.us 3057 [ + - + + :CBC 623 : foreach(lc2, pathkey->pk_eclass->ec_members)
+ + ]
3058 : : {
3059 : 446 : EquivalenceMember *member = (EquivalenceMember *) lfirst(lc2);
3060 : : int indexcol;
3061 : :
3062 : : /* No possibility of match if it references other relations */
3063 [ + + ]: 446 : if (!bms_equal(member->em_relids, index->rel->relids))
4882 tgl@sss.pgh.pa.us 3064 :GBC 32 : continue;
3065 : :
3066 : : /*
3067 : : * We allow any column of the index to match each pathkey; they
3068 : : * don't have to match left-to-right as you might expect. This is
3069 : : * correct for GiST, and it doesn't matter for SP-GiST because
3070 : : * that doesn't handle multiple columns anyway, and no other
3071 : : * existing AMs support amcanorderbyop. We might need different
3072 : : * logic in future for other implementations.
3073 : : */
1888 tgl@sss.pgh.pa.us 3074 [ + + ]:CBC 626 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3075 : : {
3076 : : Expr *expr;
3077 : :
4882 3078 : 449 : expr = match_clause_to_ordering_op(index,
3079 : : indexcol,
3080 : : member->em_expr,
3081 : : pathkey->pk_opfamily);
3082 [ + + ]: 449 : if (expr)
3083 : : {
285 drowley@postgresql.o 3084 :GNC 237 : *orderby_clauses_p = lappend(*orderby_clauses_p, expr);
3085 : 237 : *clause_columns_p = lappend_int(*clause_columns_p, indexcol);
4882 tgl@sss.pgh.pa.us 3086 :CBC 237 : found = true;
3087 : 237 : break;
3088 : : }
3089 : : }
3090 : :
3091 [ + + ]: 414 : if (found) /* don't want to look at remaining members */
3092 : 237 : break;
3093 : : }
3094 : :
3095 : : /*
3096 : : * Return the matches found so far when this pathkey couldn't be
3097 : : * matched to the index.
3098 : : */
285 drowley@postgresql.o 3099 [ + + ]:GNC 414 : if (!found)
4495 tgl@sss.pgh.pa.us 3100 :CBC 177 : return;
3101 : : }
3102 : : }
3103 : :
3104 : : /*
3105 : : * match_clause_to_ordering_op
3106 : : * Determines whether an ordering operator expression matches an
3107 : : * index column.
3108 : : *
3109 : : * This is similar to, but simpler than, match_clause_to_indexcol.
3110 : : * We only care about simple OpExpr cases. The input is a bare
3111 : : * expression that is being ordered by, which must be of the form
3112 : : * (indexkey op const) or (const op indexkey) where op is an ordering
3113 : : * operator for the column's opfamily.
3114 : : *
3115 : : * 'index' is the index of interest.
3116 : : * 'indexcol' is a column number of 'index' (counting from 0).
3117 : : * 'clause' is the ordering expression to be tested.
3118 : : * 'pk_opfamily' is the btree opfamily describing the required sort order.
3119 : : *
3120 : : * Note that we currently do not consider the collation of the ordering
3121 : : * operator's result. In practical cases the result type will be numeric
3122 : : * and thus have no collation, and it's not very clear what to match to
3123 : : * if it did have a collation. The index's collation should match the
3124 : : * ordering operator's input collation, not its result.
3125 : : *
3126 : : * If successful, return 'clause' as-is if the indexkey is on the left,
3127 : : * otherwise a commuted copy of 'clause'. If no match, return NULL.
3128 : : */
3129 : : static Expr *
4882 3130 : 449 : match_clause_to_ordering_op(IndexOptInfo *index,
3131 : : int indexcol,
3132 : : Expr *clause,
3133 : : Oid pk_opfamily)
3134 : : {
3135 : : Oid opfamily;
3136 : : Oid idxcollation;
3137 : : Node *leftop,
3138 : : *rightop;
3139 : : Oid expr_op;
3140 : : Oid expr_coll;
3141 : : Oid sortfamily;
3142 : : bool commuted;
3143 : :
2194 teodor@sigaev.ru 3144 [ - + ]: 449 : Assert(indexcol < index->nkeycolumns);
3145 : :
3146 : 449 : opfamily = index->opfamily[indexcol];
3147 : 449 : idxcollation = index->indexcollations[indexcol];
3148 : :
3149 : : /*
3150 : : * Clause must be a binary opclause.
3151 : : */
4882 tgl@sss.pgh.pa.us 3152 [ + + ]: 449 : if (!is_opclause(clause))
3153 : 212 : return NULL;
3154 : 237 : leftop = get_leftop(clause);
3155 : 237 : rightop = get_rightop(clause);
3156 [ + - - + ]: 237 : if (!leftop || !rightop)
4882 tgl@sss.pgh.pa.us 3157 :UBC 0 : return NULL;
4882 tgl@sss.pgh.pa.us 3158 :CBC 237 : expr_op = ((OpExpr *) clause)->opno;
4755 3159 : 237 : expr_coll = ((OpExpr *) clause)->inputcollid;
3160 : :
3161 : : /*
3162 : : * We can forget the whole thing right away if wrong collation.
3163 : : */
4581 3164 [ + + - + ]: 237 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
4755 tgl@sss.pgh.pa.us 3165 :UBC 0 : return NULL;
3166 : :
3167 : : /*
3168 : : * Check for clauses of the form: (indexkey operator constant) or
3169 : : * (constant operator indexkey).
3170 : : */
4882 tgl@sss.pgh.pa.us 3171 [ + + ]:CBC 237 : if (match_index_to_operand(leftop, indexcol, index) &&
3172 [ + - ]: 225 : !contain_var_clause(rightop) &&
3173 [ + - ]: 225 : !contain_volatile_functions(rightop))
3174 : : {
3175 : 225 : commuted = false;
3176 : : }
3177 [ + - ]: 12 : else if (match_index_to_operand(rightop, indexcol, index) &&
3178 [ + - ]: 12 : !contain_var_clause(leftop) &&
3179 [ + - ]: 12 : !contain_volatile_functions(leftop))
3180 : : {
3181 : : /* Might match, but we need a commuted operator */
3182 : 12 : expr_op = get_commutator(expr_op);
3183 [ - + ]: 12 : if (expr_op == InvalidOid)
4882 tgl@sss.pgh.pa.us 3184 :UBC 0 : return NULL;
4882 tgl@sss.pgh.pa.us 3185 :CBC 12 : commuted = true;
3186 : : }
3187 : : else
4882 tgl@sss.pgh.pa.us 3188 :UBC 0 : return NULL;
3189 : :
3190 : : /*
3191 : : * Is the (commuted) operator an ordering operator for the opfamily? And
3192 : : * if so, does it yield the right sorting semantics?
3193 : : */
4882 tgl@sss.pgh.pa.us 3194 :CBC 237 : sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3195 [ - + ]: 237 : if (sortfamily != pk_opfamily)
4882 tgl@sss.pgh.pa.us 3196 :UBC 0 : return NULL;
3197 : :
3198 : : /* We have a match. Return clause or a commuted version thereof. */
4882 tgl@sss.pgh.pa.us 3199 [ + + ]:CBC 237 : if (commuted)
3200 : : {
3201 : 12 : OpExpr *newclause = makeNode(OpExpr);
3202 : :
3203 : : /* flat-copy all the fields of clause */
3204 : 12 : memcpy(newclause, clause, sizeof(OpExpr));
3205 : :
3206 : : /* commute it */
3207 : 12 : newclause->opno = expr_op;
3208 : 12 : newclause->opfuncid = InvalidOid;
3209 : 12 : newclause->args = list_make2(rightop, leftop);
3210 : :
3211 : 12 : clause = (Expr *) newclause;
3212 : : }
3213 : :
3214 : 237 : return clause;
3215 : : }
3216 : :
3217 : :
3218 : : /****************************************************************************
3219 : : * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3220 : : ****************************************************************************/
3221 : :
3222 : : /*
3223 : : * check_index_predicates
3224 : : * Set the predicate-derived IndexOptInfo fields for each index
3225 : : * of the specified relation.
3226 : : *
3227 : : * predOK is set true if the index is partial and its predicate is satisfied
3228 : : * for this query, ie the query's WHERE clauses imply the predicate.
3229 : : *
3230 : : * indrestrictinfo is set to the relation's baserestrictinfo list less any
3231 : : * conditions that are implied by the index's predicate. (Obviously, for a
3232 : : * non-partial index, this is the same as baserestrictinfo.) Such conditions
3233 : : * can be dropped from the plan when using the index, in certain cases.
3234 : : *
3235 : : * At one time it was possible for this to get re-run after adding more
3236 : : * restrictions to the rel, thus possibly letting us prove more indexes OK.
3237 : : * That doesn't happen any more (at least not in the core code's usage),
3238 : : * but this code still supports it in case extensions want to mess with the
3239 : : * baserestrictinfo list. We assume that adding more restrictions can't make
3240 : : * an index not predOK. We must recompute indrestrictinfo each time, though,
3241 : : * to make sure any newly-added restrictions get into it if needed.
3242 : : */
3243 : : void
2936 3244 : 173403 : check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3245 : : {
3246 : : List *clauselist;
3247 : : bool have_partial;
3248 : : bool is_target_rel;
3249 : : Relids otherrels;
3250 : : ListCell *lc;
3251 : :
3252 : : /* Indexes are available only on base or "other" member relations. */
2568 rhaas@postgresql.org 3253 [ + + - + ]: 173403 : Assert(IS_SIMPLE_REL(rel));
3254 : :
3255 : : /*
3256 : : * Initialize the indrestrictinfo lists to be identical to
3257 : : * baserestrictinfo, and check whether there are any partial indexes. If
3258 : : * not, this is all we need to do.
3259 : : */
4168 tgl@sss.pgh.pa.us 3260 : 173403 : have_partial = false;
3261 [ + + + + : 470628 : foreach(lc, rel->indexlist)
+ + ]
3262 : : {
3263 : 297225 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3264 : :
2936 3265 : 297225 : index->indrestrictinfo = rel->baserestrictinfo;
3266 [ + + ]: 297225 : if (index->indpred)
3267 : 493 : have_partial = true;
3268 : : }
4168 3269 [ + + ]: 173403 : if (!have_partial)
3270 : 173069 : return;
3271 : :
3272 : : /*
3273 : : * Construct a list of clauses that we can assume true for the purpose of
3274 : : * proving the index(es) usable. Restriction clauses for the rel are
3275 : : * always usable, and so are any join clauses that are "movable to" this
3276 : : * rel. Also, we can consider any EC-derivable join clauses (which must
3277 : : * be "movable to" this rel, by definition).
3278 : : */
3279 : 334 : clauselist = list_copy(rel->baserestrictinfo);
3280 : :
3281 : : /* Scan the rel's join clauses */
3282 [ - + - - : 334 : foreach(lc, rel->joininfo)
- + ]
3283 : : {
4168 tgl@sss.pgh.pa.us 3284 :UBC 0 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3285 : :
3286 : : /* Check if clause can be moved to this rel */
3893 3287 [ # # ]: 0 : if (!join_clause_is_movable_to(rinfo, rel))
4168 3288 : 0 : continue;
3289 : :
3290 : 0 : clauselist = lappend(clauselist, rinfo);
3291 : : }
3292 : :
3293 : : /*
3294 : : * Add on any equivalence-derivable join clauses. Computing the correct
3295 : : * relid sets for generate_join_implied_equalities is slightly tricky
3296 : : * because the rel could be a child rel rather than a true baserel, and in
3297 : : * that case we must subtract its parents' relid(s) from all_query_rels.
3298 : : * Additionally, we mustn't consider clauses that are only computable
3299 : : * after outer joins that can null the rel.
3300 : : */
4168 tgl@sss.pgh.pa.us 3301 [ + + ]:CBC 334 : if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
440 3302 : 36 : otherrels = bms_difference(root->all_query_rels,
3483 3303 : 36 : find_childrel_parents(root, rel));
3304 : : else
440 3305 : 298 : otherrels = bms_difference(root->all_query_rels, rel->relids);
416 3306 : 334 : otherrels = bms_del_members(otherrels, rel->nulling_relids);
3307 : :
4168 3308 [ + + ]: 334 : if (!bms_is_empty(otherrels))
3309 : : clauselist =
3310 : 49 : list_concat(clauselist,
3311 : 49 : generate_join_implied_equalities(root,
2489 3312 : 49 : bms_union(rel->relids,
3313 : : otherrels),
3314 : : otherrels,
3315 : : rel,
3316 : : NULL));
3317 : :
3318 : : /*
3319 : : * Normally we remove quals that are implied by a partial index's
3320 : : * predicate from indrestrictinfo, indicating that they need not be
3321 : : * checked explicitly by an indexscan plan using this index. However, if
3322 : : * the rel is a target relation of UPDATE/DELETE/MERGE/SELECT FOR UPDATE,
3323 : : * we cannot remove such quals from the plan, because they need to be in
3324 : : * the plan so that they will be properly rechecked by EvalPlanQual
3325 : : * testing. Some day we might want to remove such quals from the main
3326 : : * plan anyway and pass them through to EvalPlanQual via a side channel;
3327 : : * but for now, we just don't remove implied quals at all for target
3328 : : * relations.
3329 : : */
1110 3330 [ + + + + ]: 602 : is_target_rel = (bms_is_member(rel->relid, root->all_result_relids) ||
2936 3331 : 268 : get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
3332 : :
3333 : : /*
3334 : : * Now try to prove each index predicate true, and compute the
3335 : : * indrestrictinfo lists for partial indexes. Note that we compute the
3336 : : * indrestrictinfo list even for non-predOK indexes; this might seem
3337 : : * wasteful, but we may be able to use such indexes in OR clauses, cf
3338 : : * generate_bitmap_or_paths().
3339 : : */
4168 3340 [ + - + + : 1017 : foreach(lc, rel->indexlist)
+ + ]
3341 : : {
3342 : 683 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3343 : : ListCell *lcr;
3344 : :
6883 3345 [ + + ]: 683 : if (index->indpred == NIL)
2936 3346 : 190 : continue; /* ignore non-partial indexes here */
3347 : :
3348 [ + - ]: 493 : if (!index->predOK) /* don't repeat work if already proven OK */
2496 rhaas@postgresql.org 3349 : 493 : index->predOK = predicate_implied_by(index->indpred, clauselist,
3350 : : false);
3351 : :
3352 : : /* If rel is an update target, leave indrestrictinfo as set above */
2936 tgl@sss.pgh.pa.us 3353 [ + + ]: 493 : if (is_target_rel)
3354 : 96 : continue;
3355 : :
3356 : : /* Else compute indrestrictinfo as the non-implied quals */
3357 : 397 : index->indrestrictinfo = NIL;
3358 [ + + + + : 936 : foreach(lcr, rel->baserestrictinfo)
+ + ]
3359 : : {
3360 : 539 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
3361 : :
3362 : : /* predicate_implied_by() assumes first arg is immutable */
3363 [ + - ]: 539 : if (contain_mutable_functions((Node *) rinfo->clause) ||
3364 [ + + ]: 539 : !predicate_implied_by(list_make1(rinfo->clause),
3365 : : index->indpred, false))
3366 : 385 : index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
3367 : : }
3368 : : }
3369 : : }
3370 : :
3371 : : /****************************************************************************
3372 : : * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
3373 : : ****************************************************************************/
3374 : :
3375 : : /*
3376 : : * ec_member_matches_indexcol
3377 : : * Test whether an EquivalenceClass member matches an index column.
3378 : : *
3379 : : * This is a callback for use by generate_implied_equalities_for_column.
3380 : : */
3381 : : static bool
4042 3382 : 151031 : ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
3383 : : EquivalenceClass *ec, EquivalenceMember *em,
3384 : : void *arg)
3385 : : {
3386 : 151031 : IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
3387 : 151031 : int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
3388 : : Oid curFamily;
3389 : : Oid curCollation;
3390 : :
2194 teodor@sigaev.ru 3391 [ - + ]: 151031 : Assert(indexcol < index->nkeycolumns);
3392 : :
3393 : 151031 : curFamily = index->opfamily[indexcol];
3394 : 151031 : curCollation = index->indexcollations[indexcol];
3395 : :
3396 : : /*
3397 : : * If it's a btree index, we can reject it if its opfamily isn't
3398 : : * compatible with the EC, since no clause generated from the EC could be
3399 : : * used with the index. For non-btree indexes, we can't easily tell
3400 : : * whether clauses generated from the EC could be used with the index, so
3401 : : * don't check the opfamily. This might mean we return "true" for a
3402 : : * useless EC, so we have to recheck the results of
3403 : : * generate_implied_equalities_for_column; see
3404 : : * match_eclass_clauses_to_index.
3405 : : */
4461 tgl@sss.pgh.pa.us 3406 [ + + ]: 151031 : if (index->relam == BTREE_AM_OID &&
3407 [ + + ]: 151010 : !list_member_oid(ec->ec_opfamilies, curFamily))
3408 : 45846 : return false;
3409 : :
3410 : : /* We insist on collation match for all index types, though */
3411 [ + + + + ]: 105185 : if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
3412 : 7 : return false;
3413 : :
3414 : 105178 : return match_index_to_operand((Node *) em->em_expr, indexcol, index);
3415 : : }
3416 : :
3417 : : /*
3418 : : * relation_has_unique_index_for
3419 : : * Determine whether the relation provably has at most one row satisfying
3420 : : * a set of equality conditions, because the conditions constrain all
3421 : : * columns of some unique index.
3422 : : *
3423 : : * The conditions can be represented in either or both of two ways:
3424 : : * 1. A list of RestrictInfo nodes, where the caller has already determined
3425 : : * that each condition is a mergejoinable equality with an expression in
3426 : : * this relation on one side, and an expression not involving this relation
3427 : : * on the other. The transient outer_is_left flag is used to identify which
3428 : : * side we should look at: left side if outer_is_left is false, right side
3429 : : * if it is true.
3430 : : * 2. A list of expressions in this relation, and a corresponding list of
3431 : : * equality operators. The caller must have already checked that the operators
3432 : : * represent equality. (Note: the operators could be cross-type; the
3433 : : * expressions should correspond to their RHS inputs.)
3434 : : *
3435 : : * The caller need only supply equality conditions arising from joins;
3436 : : * this routine automatically adds in any usable baserestrictinfo clauses.
3437 : : * (Note that the passed-in restrictlist will be destructively modified!)
3438 : : */
3439 : : bool
5323 3440 : 443 : relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
3441 : : List *restrictlist,
3442 : : List *exprlist, List *oprlist)
3443 : : {
172 akorotkov@postgresql 3444 :GNC 443 : return relation_has_unique_index_ext(root, rel, restrictlist,
3445 : : exprlist, oprlist, NULL);
3446 : : }
3447 : :
3448 : : /*
3449 : : * relation_has_unique_index_ext
3450 : : * Same as relation_has_unique_index_for(), but supports extra_clauses
3451 : : * parameter. If extra_clauses isn't NULL, return baserestrictinfo clauses
3452 : : * which were used to derive uniqueness.
3453 : : */
3454 : : bool
3455 : 83843 : relation_has_unique_index_ext(PlannerInfo *root, RelOptInfo *rel,
3456 : : List *restrictlist,
3457 : : List *exprlist, List *oprlist,
3458 : : List **extra_clauses)
3459 : : {
3460 : : ListCell *ic;
3461 : :
4554 tgl@sss.pgh.pa.us 3462 [ - + ]:CBC 83843 : Assert(list_length(exprlist) == list_length(oprlist));
3463 : :
3464 : : /* Short-circuit if no indexes... */
3465 [ + + ]: 83843 : if (rel->indexlist == NIL)
3466 : 220 : return false;
3467 : :
3468 : : /*
3469 : : * Examine the rel's restriction clauses for usable var = const clauses
3470 : : * that we can add to the restrictlist.
3471 : : */
3472 [ + + + + : 138645 : foreach(ic, rel->baserestrictinfo)
+ + ]
3473 : : {
3474 : 55022 : RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
3475 : :
3476 : : /*
3477 : : * Note: can_join won't be set for a restriction clause, but
3478 : : * mergeopfamilies will be if it has a mergejoinable operator and
3479 : : * doesn't contain volatile functions.
3480 : : */
3481 [ + + ]: 55022 : if (restrictinfo->mergeopfamilies == NIL)
3482 : 25000 : continue; /* not mergejoinable */
3483 : :
3484 : : /*
3485 : : * The clause certainly doesn't refer to anything but the given rel.
3486 : : * If either side is pseudoconstant then we can use it.
3487 : : */
3488 [ + + ]: 30022 : if (bms_is_empty(restrictinfo->left_relids))
3489 : : {
3490 : : /* righthand side is inner */
3491 : 20 : restrictinfo->outer_is_left = true;
3492 : : }
3493 [ + + ]: 30002 : else if (bms_is_empty(restrictinfo->right_relids))
3494 : : {
3495 : : /* lefthand side is inner */
3496 : 29939 : restrictinfo->outer_is_left = false;
3497 : : }
3498 : : else
3499 : 63 : continue;
3500 : :
3501 : : /* OK, add to list */
3502 : 29959 : restrictlist = lappend(restrictlist, restrictinfo);
3503 : : }
3504 : :
3505 : : /* Short-circuit the easy case */
3506 [ + + + + ]: 83623 : if (restrictlist == NIL && exprlist == NIL)
5323 3507 : 650 : return false;
3508 : :
3509 : : /* Examine each index of the relation ... */
3510 [ + - + + : 215854 : foreach(ic, rel->indexlist)
+ + ]
3511 : : {
5161 bruce@momjian.us 3512 : 183824 : IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
3513 : : int c;
172 akorotkov@postgresql 3514 :GNC 183824 : List *exprs = NIL;
3515 : :
3516 : : /*
3517 : : * If the index is not unique, or not immediately enforced, or if it's
3518 : : * a partial index, it's useless here. We're unable to make use of
3519 : : * predOK partial unique indexes due to the fact that
3520 : : * check_index_predicates() also makes use of join predicates to
3521 : : * determine if the partial index is usable. Here we need proofs that
3522 : : * hold true before any joins are evaluated.
3523 : : */
300 drowley@postgresql.o 3524 [ + + + - :CBC 183824 : if (!ind->unique || !ind->immediate || ind->indpred != NIL)
+ + ]
5323 tgl@sss.pgh.pa.us 3525 : 54141 : continue;
3526 : :
3527 : : /*
3528 : : * Try to find each index column in the lists of conditions. This is
3529 : : * O(N^2) or worse, but we expect all the lists to be short.
3530 : : */
1888 3531 [ + + ]: 209770 : for (c = 0; c < ind->nkeycolumns; c++)
3532 : : {
4554 3533 : 158827 : bool matched = false;
3534 : : ListCell *lc;
3535 : : ListCell *lc2;
3536 : :
5323 3537 [ + + + + : 298013 : foreach(lc, restrictlist)
+ + ]
3538 : : {
5161 bruce@momjian.us 3539 : 219270 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3540 : : Node *rexpr;
3541 : :
3542 : : /*
3543 : : * The condition's equality operator must be a member of the
3544 : : * index opfamily, else it is not asserting the right kind of
3545 : : * equality behavior for this index. We check this first
3546 : : * since it's probably cheaper than match_index_to_operand().
3547 : : */
5323 tgl@sss.pgh.pa.us 3548 [ + + ]: 219270 : if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
3549 : 65542 : continue;
3550 : :
3551 : : /*
3552 : : * XXX at some point we may need to check collations here too.
3553 : : * For the moment we assume all collations reduce to the same
3554 : : * notion of equality.
3555 : : */
3556 : :
3557 : : /* OK, see if the condition operand matches the index key */
3558 [ + + ]: 153728 : if (rinfo->outer_is_left)
3559 : 68558 : rexpr = get_rightop(rinfo->clause);
3560 : : else
3561 : 85170 : rexpr = get_leftop(rinfo->clause);
3562 : :
3563 [ + + ]: 153728 : if (match_index_to_operand(rexpr, c, ind))
3564 : : {
2489 3565 : 80084 : matched = true; /* column is unique */
3566 : :
172 akorotkov@postgresql 3567 [ + + ]:GNC 80084 : if (bms_membership(rinfo->clause_relids) == BMS_SINGLETON)
3568 : : {
3569 : : MemoryContext oldMemCtx =
3570 : 21349 : MemoryContextSwitchTo(root->planner_cxt);
3571 : :
3572 : : /*
3573 : : * Add filter clause into a list allowing caller to
3574 : : * know if uniqueness have made not only by join
3575 : : * clauses.
3576 : : */
3577 [ + + - + ]: 21349 : Assert(bms_is_empty(rinfo->left_relids) ||
3578 : : bms_is_empty(rinfo->right_relids));
3579 [ + + ]: 21349 : if (extra_clauses)
3580 : 123 : exprs = lappend(exprs, rinfo);
3581 : 21349 : MemoryContextSwitchTo(oldMemCtx);
3582 : : }
3583 : :
4554 tgl@sss.pgh.pa.us 3584 :CBC 80084 : break;
3585 : : }
3586 : : }
3587 : :
3588 [ + + ]: 158827 : if (matched)
3589 : 80084 : continue;
3590 : :
3591 [ + + + + : 78822 : forboth(lc, exprlist, lc2, oprlist)
+ + + + +
+ + - +
+ ]
3592 : : {
4554 tgl@sss.pgh.pa.us 3593 :GBC 82 : Node *expr = (Node *) lfirst(lc);
3594 : 82 : Oid opr = lfirst_oid(lc2);
3595 : :
3596 : : /* See if the expression matches the index key */
3597 [ + + ]: 82 : if (!match_index_to_operand(expr, c, ind))
3598 : 79 : continue;
3599 : :
3600 : : /*
3601 : : * The equality operator must be a member of the index
3602 : : * opfamily, else it is not asserting the right kind of
3603 : : * equality behavior for this index. We assume the caller
3604 : : * determined it is an equality operator, so we don't need to
3605 : : * check any more tightly than this.
3606 : : */
3607 [ - + ]: 3 : if (!op_in_opfamily(opr, ind->opfamily[c]))
4554 tgl@sss.pgh.pa.us 3608 :UBC 0 : continue;
3609 : :
3610 : : /*
3611 : : * XXX at some point we may need to check collations here too.
3612 : : * For the moment we assume all collations reduce to the same
3613 : : * notion of equality.
3614 : : */
3615 : :
4326 bruce@momjian.us 3616 :GBC 3 : matched = true; /* column is unique */
4554 tgl@sss.pgh.pa.us 3617 : 3 : break;
3618 : : }
3619 : :
4554 tgl@sss.pgh.pa.us 3620 [ + + ]:CBC 78743 : if (!matched)
5323 3621 : 78740 : break; /* no match; this index doesn't help us */
3622 : : }
3623 : :
3624 : : /* Matched all key columns of this index? */
1888 3625 [ + + ]: 129683 : if (c == ind->nkeycolumns)
3626 : : {
172 akorotkov@postgresql 3627 [ + + ]:GNC 50943 : if (extra_clauses)
3628 : 347 : *extra_clauses = exprs;
5323 tgl@sss.pgh.pa.us 3629 :CBC 50943 : return true;
3630 : : }
3631 : : }
3632 : :
3633 : 32030 : return false;
3634 : : }
3635 : :
3636 : : /*
3637 : : * indexcol_is_bool_constant_for_query
3638 : : *
3639 : : * If an index column is constrained to have a constant value by the query's
3640 : : * WHERE conditions, then it's irrelevant for sort-order considerations.
3641 : : * Usually that means we have a restriction clause WHERE indexcol = constant,
3642 : : * which gets turned into an EquivalenceClass containing a constant, which
3643 : : * is recognized as redundant by build_index_pathkeys(). But if the index
3644 : : * column is a boolean variable (or expression), then we are not going to
3645 : : * see WHERE indexcol = constant, because expression preprocessing will have
3646 : : * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
3647 : : * going to have a matching EquivalenceClass (unless the query also contains
3648 : : * "ORDER BY indexcol"). To allow such cases to work the same as they would
3649 : : * for non-boolean values, this function is provided to detect whether the
3650 : : * specified index column matches a boolean restriction clause.
3651 : : */
3652 : : bool
1179 3653 : 252066 : indexcol_is_bool_constant_for_query(PlannerInfo *root,
3654 : : IndexOptInfo *index,
3655 : : int indexcol)
3656 : : {
3657 : : ListCell *lc;
3658 : :
3659 : : /* If the index isn't boolean, we can't possibly get a match */
2646 3660 [ + + ]: 252066 : if (!IsBooleanOpfamily(index->opfamily[indexcol]))
3661 : 251760 : return false;
3662 : :
3663 : : /* Check each restriction clause for the index's rel */
3664 [ + + + + : 324 : foreach(lc, index->rel->baserestrictinfo)
+ + ]
3665 : : {
3666 : 72 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3667 : :
3668 : : /*
3669 : : * As in match_clause_to_indexcol, never match pseudoconstants to
3670 : : * indexes. (It might be semantically okay to do so here, but the
3671 : : * odds of getting a match are negligible, so don't waste the cycles.)
3672 : : */
3673 [ - + ]: 72 : if (rinfo->pseudoconstant)
2646 tgl@sss.pgh.pa.us 3674 :UBC 0 : continue;
3675 : :
3676 : : /* See if we can match the clause's expression to the index column */
1179 tgl@sss.pgh.pa.us 3677 [ + + ]:CBC 72 : if (match_boolean_index_clause(root, rinfo, indexcol, index))
2646 3678 : 54 : return true;
3679 : : }
3680 : :
3681 : 252 : return false;
3682 : : }
3683 : :
3684 : :
3685 : : /****************************************************************************
3686 : : * ---- ROUTINES TO CHECK OPERANDS ----
3687 : : ****************************************************************************/
3688 : :
3689 : : /*
3690 : : * match_index_to_operand()
3691 : : * Generalized test for a match between an index's key
3692 : : * and the operand on one side of a restriction or join clause.
3693 : : *
3694 : : * operand: the nodetree to be compared to the index
3695 : : * indexcol: the column number of the index (counting from 0)
3696 : : * index: the index of interest
3697 : : *
3698 : : * Note that we aren't interested in collations here; the caller must check
3699 : : * for a collation match, if it's dealing with an operator where that matters.
3700 : : *
3701 : : * This is exported for use in selfuncs.c.
3702 : : */
3703 : : bool
7627 3704 : 1467202 : match_index_to_operand(Node *operand,
3705 : : int indexcol,
3706 : : IndexOptInfo *index)
3707 : : {
3708 : : int indkey;
3709 : :
3710 : : /*
3711 : : * Ignore any RelabelType node above the operand. This is needed to be
3712 : : * able to apply indexscanning in binary-compatible-operator cases. Note:
3713 : : * we can assume there is at most one RelabelType node;
3714 : : * eval_const_expressions() will have simplified if more than one.
3715 : : */
8645 3716 [ + - + + ]: 1467202 : if (operand && IsA(operand, RelabelType))
7760 3717 : 10477 : operand = (Node *) ((RelabelType *) operand)->arg;
3718 : :
7627 3719 : 1467202 : indkey = index->indexkeys[indexcol];
3720 [ + + ]: 1467202 : if (indkey != 0)
3721 : : {
3722 : : /*
3723 : : * Simple index column; operand must be a matching Var.
3724 : : */
8645 3725 [ + - + + ]: 1464143 : if (operand && IsA(operand, Var) &&
6958 3726 [ + + ]: 1084418 : index->rel->relid == ((Var *) operand)->varno &&
440 3727 [ + + ]: 996932 : indkey == ((Var *) operand)->varattno &&
3728 [ + + ]: 346946 : ((Var *) operand)->varnullingrels == NULL)
9008 3729 : 344359 : return true;
3730 : : }
3731 : : else
3732 : : {
3733 : : /*
3734 : : * Index expression; find the correct expression. (This search could
3735 : : * be avoided, at the cost of complicating all the callers of this
3736 : : * routine; doesn't seem worth it.)
3737 : : */
3738 : : ListCell *indexpr_item;
3739 : : int i;
3740 : : Node *indexkey;
3741 : :
7263 neilc@samurai.com 3742 : 3059 : indexpr_item = list_head(index->indexprs);
7627 tgl@sss.pgh.pa.us 3743 [ - + ]: 3059 : for (i = 0; i < indexcol; i++)
3744 : : {
7627 tgl@sss.pgh.pa.us 3745 [ # # ]:UBC 0 : if (index->indexkeys[i] == 0)
3746 : : {
7263 neilc@samurai.com 3747 [ # # ]: 0 : if (indexpr_item == NULL)
7627 tgl@sss.pgh.pa.us 3748 [ # # ]: 0 : elog(ERROR, "wrong number of index expressions");
1735 3749 : 0 : indexpr_item = lnext(index->indexprs, indexpr_item);
3750 : : }
3751 : : }
7263 neilc@samurai.com 3752 [ - + ]:CBC 3059 : if (indexpr_item == NULL)
7627 tgl@sss.pgh.pa.us 3753 [ # # ]:UBC 0 : elog(ERROR, "wrong number of index expressions");
7263 neilc@samurai.com 3754 :CBC 3059 : indexkey = (Node *) lfirst(indexpr_item);
3755 : :
3756 : : /*
3757 : : * Does it match the operand? Again, strip any relabeling.
3758 : : */
7627 tgl@sss.pgh.pa.us 3759 [ + - + + ]: 3059 : if (indexkey && IsA(indexkey, RelabelType))
3760 : 5 : indexkey = (Node *) ((RelabelType *) indexkey)->arg;
3761 : :
3762 [ + + ]: 3059 : if (equal(indexkey, operand))
3763 : 1082 : return true;
3764 : : }
3765 : :
3766 : 1121761 : return false;
3767 : : }
3768 : :
3769 : : /*
3770 : : * is_pseudo_constant_for_index()
3771 : : * Test whether the given expression can be used as an indexscan
3772 : : * comparison value.
3773 : : *
3774 : : * An indexscan comparison value must not contain any volatile functions,
3775 : : * and it can't contain any Vars of the index's own table. Vars of
3776 : : * other tables are okay, though; in that case we'd be producing an
3777 : : * indexqual usable in a parameterized indexscan. This is, therefore,
3778 : : * a weaker condition than is_pseudo_constant_clause().
3779 : : *
3780 : : * This function is exported for use by planner support functions,
3781 : : * which will have available the IndexOptInfo, but not any RestrictInfo
3782 : : * infrastructure. It is making the same test made by functions above
3783 : : * such as match_opclause_to_indexcol(), but those rely where possible
3784 : : * on RestrictInfo information about variable membership.
3785 : : *
3786 : : * expr: the nodetree to be checked
3787 : : * index: the index of interest
3788 : : */
3789 : : bool
1179 tgl@sss.pgh.pa.us 3790 :UBC 0 : is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
3791 : : {
3792 : : /* pull_varnos is cheaper than volatility check, so do that first */
3793 [ # # ]: 0 : if (bms_is_member(index->rel->relid, pull_varnos(root, expr)))
1889 3794 : 0 : return false; /* no good, contains Var of table */
3795 [ # # ]: 0 : if (contain_volatile_functions(expr))
3796 : 0 : return false; /* no good, volatile comparison value */
3797 : 0 : return true;
3798 : : }
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