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) 1996-2025, PostgreSQL Global Development Group
8 : : * Portions Copyright (c) 1994, Regents of the University of California
9 : : *
10 : : *
11 : : * IDENTIFICATION
12 : : * src/backend/optimizer/path/indxpath.c
13 : : *
14 : : *-------------------------------------------------------------------------
15 : : */
16 : : #include "postgres.h"
17 : :
18 : : #include <math.h>
19 : :
20 : : #include "access/stratnum.h"
21 : : #include "access/sysattr.h"
22 : : #include "catalog/pg_am.h"
23 : : #include "catalog/pg_amop.h"
24 : : #include "catalog/pg_operator.h"
25 : : #include "catalog/pg_opfamily.h"
26 : : #include "catalog/pg_type.h"
27 : : #include "nodes/makefuncs.h"
28 : : #include "nodes/nodeFuncs.h"
29 : : #include "nodes/supportnodes.h"
30 : : #include "optimizer/cost.h"
31 : : #include "optimizer/optimizer.h"
32 : : #include "optimizer/pathnode.h"
33 : : #include "optimizer/paths.h"
34 : : #include "optimizer/prep.h"
35 : : #include "optimizer/restrictinfo.h"
36 : : #include "utils/lsyscache.h"
37 : : #include "utils/selfuncs.h"
38 : :
39 : :
40 : : /* XXX see PartCollMatchesExprColl */
41 : : #define IndexCollMatchesExprColl(idxcollation, exprcollation) \
42 : : ((idxcollation) == InvalidOid || (idxcollation) == (exprcollation))
43 : :
44 : : /* Whether we are looking for plain indexscan, bitmap scan, or either */
45 : : typedef enum
46 : : {
47 : : ST_INDEXSCAN, /* must support amgettuple */
48 : : ST_BITMAPSCAN, /* must support amgetbitmap */
49 : : ST_ANYSCAN, /* either is okay */
50 : : } ScanTypeControl;
51 : :
52 : : /* Data structure for collecting qual clauses that match an index */
53 : : typedef struct
54 : : {
55 : : bool nonempty; /* True if lists are not all empty */
56 : : /* Lists of IndexClause nodes, one list per index column */
57 : : List *indexclauses[INDEX_MAX_KEYS];
58 : : } IndexClauseSet;
59 : :
60 : : /* Per-path data used within choose_bitmap_and() */
61 : : typedef struct
62 : : {
63 : : Path *path; /* IndexPath, BitmapAndPath, or BitmapOrPath */
64 : : List *quals; /* the WHERE clauses it uses */
65 : : List *preds; /* predicates of its partial index(es) */
66 : : Bitmapset *clauseids; /* quals+preds represented as a bitmapset */
67 : : bool unclassifiable; /* has too many quals+preds to process? */
68 : : } PathClauseUsage;
69 : :
70 : : /* Callback argument for ec_member_matches_indexcol */
71 : : typedef struct
72 : : {
73 : : IndexOptInfo *index; /* index we're considering */
74 : : int indexcol; /* index column we want to match to */
75 : : } ec_member_matches_arg;
76 : :
77 : :
78 : : static void consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
79 : : IndexOptInfo *index,
80 : : IndexClauseSet *rclauseset,
81 : : IndexClauseSet *jclauseset,
82 : : IndexClauseSet *eclauseset,
83 : : List **bitindexpaths);
84 : : static void consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
85 : : IndexOptInfo *index,
86 : : IndexClauseSet *rclauseset,
87 : : IndexClauseSet *jclauseset,
88 : : IndexClauseSet *eclauseset,
89 : : List **bitindexpaths,
90 : : List *indexjoinclauses,
91 : : int considered_clauses,
92 : : List **considered_relids);
93 : : static void get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
94 : : IndexOptInfo *index,
95 : : IndexClauseSet *rclauseset,
96 : : IndexClauseSet *jclauseset,
97 : : IndexClauseSet *eclauseset,
98 : : List **bitindexpaths,
99 : : Relids relids,
100 : : List **considered_relids);
101 : : static bool eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
102 : : List *indexjoinclauses);
103 : : static void get_index_paths(PlannerInfo *root, RelOptInfo *rel,
104 : : IndexOptInfo *index, IndexClauseSet *clauses,
105 : : List **bitindexpaths);
106 : : static List *build_index_paths(PlannerInfo *root, RelOptInfo *rel,
107 : : IndexOptInfo *index, IndexClauseSet *clauses,
108 : : bool useful_predicate,
109 : : ScanTypeControl scantype,
110 : : bool *skip_nonnative_saop);
111 : : static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
112 : : List *clauses, List *other_clauses);
113 : : static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
114 : : List *clauses, List *other_clauses);
115 : : static Path *choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel,
116 : : List *paths);
117 : : static int path_usage_comparator(const void *a, const void *b);
118 : : static Cost bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel,
119 : : Path *ipath);
120 : : static Cost bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel,
121 : : List *paths);
122 : : static PathClauseUsage *classify_index_clause_usage(Path *path,
123 : : List **clauselist);
124 : : static void find_indexpath_quals(Path *bitmapqual, List **quals, List **preds);
125 : : static int find_list_position(Node *node, List **nodelist);
126 : : static bool check_index_only(RelOptInfo *rel, IndexOptInfo *index);
127 : : static double get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids);
128 : : static double adjust_rowcount_for_semijoins(PlannerInfo *root,
129 : : Index cur_relid,
130 : : Index outer_relid,
131 : : double rowcount);
132 : : static double approximate_joinrel_size(PlannerInfo *root, Relids relids);
133 : : static void match_restriction_clauses_to_index(PlannerInfo *root,
134 : : IndexOptInfo *index,
135 : : IndexClauseSet *clauseset);
136 : : static void match_join_clauses_to_index(PlannerInfo *root,
137 : : RelOptInfo *rel, IndexOptInfo *index,
138 : : IndexClauseSet *clauseset,
139 : : List **joinorclauses);
140 : : static void match_eclass_clauses_to_index(PlannerInfo *root,
141 : : IndexOptInfo *index,
142 : : IndexClauseSet *clauseset);
143 : : static void match_clauses_to_index(PlannerInfo *root,
144 : : List *clauses,
145 : : IndexOptInfo *index,
146 : : IndexClauseSet *clauseset);
147 : : static void match_clause_to_index(PlannerInfo *root,
148 : : RestrictInfo *rinfo,
149 : : IndexOptInfo *index,
150 : : IndexClauseSet *clauseset);
151 : : static IndexClause *match_clause_to_indexcol(PlannerInfo *root,
152 : : RestrictInfo *rinfo,
153 : : int indexcol,
154 : : IndexOptInfo *index);
155 : : static bool IsBooleanOpfamily(Oid opfamily);
156 : : static IndexClause *match_boolean_index_clause(PlannerInfo *root,
157 : : RestrictInfo *rinfo,
158 : : int indexcol, IndexOptInfo *index);
159 : : static IndexClause *match_opclause_to_indexcol(PlannerInfo *root,
160 : : RestrictInfo *rinfo,
161 : : int indexcol,
162 : : IndexOptInfo *index);
163 : : static IndexClause *match_funcclause_to_indexcol(PlannerInfo *root,
164 : : RestrictInfo *rinfo,
165 : : int indexcol,
166 : : IndexOptInfo *index);
167 : : static IndexClause *get_index_clause_from_support(PlannerInfo *root,
168 : : RestrictInfo *rinfo,
169 : : Oid funcid,
170 : : int indexarg,
171 : : int indexcol,
172 : : IndexOptInfo *index);
173 : : static IndexClause *match_saopclause_to_indexcol(PlannerInfo *root,
174 : : RestrictInfo *rinfo,
175 : : int indexcol,
176 : : IndexOptInfo *index);
177 : : static IndexClause *match_rowcompare_to_indexcol(PlannerInfo *root,
178 : : RestrictInfo *rinfo,
179 : : int indexcol,
180 : : IndexOptInfo *index);
181 : : static IndexClause *match_orclause_to_indexcol(PlannerInfo *root,
182 : : RestrictInfo *rinfo,
183 : : int indexcol,
184 : : IndexOptInfo *index);
185 : : static IndexClause *expand_indexqual_rowcompare(PlannerInfo *root,
186 : : RestrictInfo *rinfo,
187 : : int indexcol,
188 : : IndexOptInfo *index,
189 : : Oid expr_op,
190 : : bool var_on_left);
191 : : static void match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
192 : : List **orderby_clauses_p,
193 : : List **clause_columns_p);
194 : : static Expr *match_clause_to_ordering_op(IndexOptInfo *index,
195 : : int indexcol, Expr *clause, Oid pk_opfamily);
196 : : static bool ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
197 : : EquivalenceClass *ec, EquivalenceMember *em,
198 : : void *arg);
199 : :
200 : :
201 : : /*
202 : : * create_index_paths()
203 : : * Generate all interesting index paths for the given relation.
204 : : * Candidate paths are added to the rel's pathlist (using add_path).
205 : : *
206 : : * To be considered for an index scan, an index must match one or more
207 : : * restriction clauses or join clauses from the query's qual condition,
208 : : * or match the query's ORDER BY condition, or have a predicate that
209 : : * matches the query's qual condition.
210 : : *
211 : : * There are two basic kinds of index scans. A "plain" index scan uses
212 : : * only restriction clauses (possibly none at all) in its indexqual,
213 : : * so it can be applied in any context. A "parameterized" index scan uses
214 : : * join clauses (plus restriction clauses, if available) in its indexqual.
215 : : * When joining such a scan to one of the relations supplying the other
216 : : * variables used in its indexqual, the parameterized scan must appear as
217 : : * the inner relation of a nestloop join; it can't be used on the outer side,
218 : : * nor in a merge or hash join. In that context, values for the other rels'
219 : : * attributes are available and fixed during any one scan of the indexpath.
220 : : *
221 : : * An IndexPath is generated and submitted to add_path() for each plain or
222 : : * parameterized index scan this routine deems potentially interesting for
223 : : * the current query.
224 : : *
225 : : * 'rel' is the relation for which we want to generate index paths
226 : : *
227 : : * Note: check_index_predicates() must have been run previously for this rel.
228 : : *
229 : : * Note: in cases involving LATERAL references in the relation's tlist, it's
230 : : * possible that rel->lateral_relids is nonempty. Currently, we include
231 : : * lateral_relids into the parameterization reported for each path, but don't
232 : : * take it into account otherwise. The fact that any such rels *must* be
233 : : * available as parameter sources perhaps should influence our choices of
234 : : * index quals ... but for now, it doesn't seem worth troubling over.
235 : : * In particular, comments below about "unparameterized" paths should be read
236 : : * as meaning "unparameterized so far as the indexquals are concerned".
237 : : */
238 : : void
7398 tgl@sss.pgh.pa.us 239 :CBC 196236 : create_index_paths(PlannerInfo *root, RelOptInfo *rel)
240 : : {
241 : : List *indexpaths;
242 : : List *bitindexpaths;
243 : : List *bitjoinpaths;
244 : : List *joinorclauses;
245 : : IndexClauseSet rclauseset;
246 : : IndexClauseSet jclauseset;
247 : : IndexClauseSet eclauseset;
248 : : ListCell *lc;
249 : :
250 : : /* Skip the whole mess if no indexes */
7442 251 [ + + ]: 196236 : if (rel->indexlist == NIL)
252 : 34547 : return;
253 : :
254 : : /* Bitmap paths are collected and then dealt with at the end */
4971 255 : 161689 : bitindexpaths = bitjoinpaths = joinorclauses = NIL;
256 : :
257 : : /* Examine each index in turn */
4755 258 [ + - + + : 510857 : foreach(lc, rel->indexlist)
+ + ]
259 : : {
260 : 349168 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
261 : :
262 : : /* Protect limited-size array in IndexClauseSets */
2398 263 [ - + ]: 349168 : Assert(index->nkeycolumns <= INDEX_MAX_KEYS);
264 : :
265 : : /*
266 : : * Ignore partial indexes that do not match the query.
267 : : * (generate_bitmap_or_paths() might be able to do something with
268 : : * them, but that's of no concern here.)
269 : : */
4971 270 [ + + + + ]: 349168 : if (index->indpred != NIL && !index->predOK)
271 : 248 : continue;
272 : :
273 : : /*
274 : : * Identify the restriction clauses that can match the index.
275 : : */
276 [ + - + - : 11863280 : MemSet(&rclauseset, 0, sizeof(rclauseset));
+ - + - +
+ ]
2399 277 : 348920 : match_restriction_clauses_to_index(root, index, &rclauseset);
278 : :
279 : : /*
280 : : * Build index paths from the restriction clauses. These will be
281 : : * non-parameterized paths. Plain paths go directly to add_path(),
282 : : * bitmap paths are added to bitindexpaths to be handled below.
283 : : */
4971 284 : 348920 : get_index_paths(root, rel, index, &rclauseset,
285 : : &bitindexpaths);
286 : :
287 : : /*
288 : : * Identify the join clauses that can match the index. For the moment
289 : : * we keep them separate from the restriction clauses. Note that this
290 : : * step finds only "loose" join clauses that have not been merged into
291 : : * EquivalenceClasses. Also, collect join OR clauses for later.
292 : : */
293 [ + - + - : 11863280 : MemSet(&jclauseset, 0, sizeof(jclauseset));
+ - + - +
+ ]
4403 294 : 348920 : match_join_clauses_to_index(root, rel, index,
295 : : &jclauseset, &joinorclauses);
296 : :
297 : : /*
298 : : * Look for EquivalenceClasses that can generate joinclauses matching
299 : : * the index.
300 : : */
4971 301 [ + - + - : 11863280 : MemSet(&eclauseset, 0, sizeof(eclauseset));
+ - + - +
+ ]
4403 302 : 348920 : match_eclass_clauses_to_index(root, index,
303 : : &eclauseset);
304 : :
305 : : /*
306 : : * If we found any plain or eclass join clauses, build parameterized
307 : : * index paths using them.
308 : : */
4971 309 [ + + + + ]: 348920 : if (jclauseset.nonempty || eclauseset.nonempty)
310 : 62962 : consider_index_join_clauses(root, rel, index,
311 : : &rclauseset,
312 : : &jclauseset,
313 : : &eclauseset,
314 : : &bitjoinpaths);
315 : : }
316 : :
317 : : /*
318 : : * Generate BitmapOrPaths for any suitable OR-clauses present in the
319 : : * restriction list. Add these to bitindexpaths.
320 : : */
321 : 161689 : indexpaths = generate_bitmap_or_paths(root, rel,
322 : : rel->baserestrictinfo, NIL);
323 : 161689 : bitindexpaths = list_concat(bitindexpaths, indexpaths);
324 : :
325 : : /*
326 : : * Likewise, generate BitmapOrPaths for any suitable OR-clauses present in
327 : : * the joinclause list. Add these to bitjoinpaths.
328 : : */
329 : 161689 : indexpaths = generate_bitmap_or_paths(root, rel,
330 : : joinorclauses, rel->baserestrictinfo);
331 : 161689 : bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
332 : :
333 : : /*
334 : : * If we found anything usable, generate a BitmapHeapPath for the most
335 : : * promising combination of restriction bitmap index paths. Note there
336 : : * will be only one such path no matter how many indexes exist. This
337 : : * should be sufficient since there's basically only one figure of merit
338 : : * (total cost) for such a path.
339 : : */
340 [ + + ]: 161689 : if (bitindexpaths != NIL)
341 : : {
342 : : Path *bitmapqual;
343 : : BitmapHeapPath *bpath;
344 : :
345 : 99398 : bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
4759 346 : 99398 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
347 : : rel->lateral_relids, 1.0, 0);
4971 348 : 99398 : add_path(rel, (Path *) bpath);
349 : :
350 : : /* create a partial bitmap heap path */
3104 rhaas@postgresql.org 351 [ + + + + ]: 99398 : if (rel->consider_parallel && rel->lateral_relids == NULL)
352 : 71749 : create_partial_bitmap_paths(root, rel, bitmapqual);
353 : : }
354 : :
355 : : /*
356 : : * Likewise, if we found anything usable, generate BitmapHeapPaths for the
357 : : * most promising combinations of join bitmap index paths. Our strategy
358 : : * is to generate one such path for each distinct parameterization seen
359 : : * among the available bitmap index paths. This may look pretty
360 : : * expensive, but usually there won't be very many distinct
361 : : * parameterizations. (This logic is quite similar to that in
362 : : * consider_index_join_clauses, but we're working with whole paths not
363 : : * individual clauses.)
364 : : */
4971 tgl@sss.pgh.pa.us 365 [ + + ]: 161689 : if (bitjoinpaths != NIL)
366 : : {
367 : : List *all_path_outers;
368 : :
369 : : /* Identify each distinct parameterization seen in bitjoinpaths */
1880 370 : 57769 : all_path_outers = NIL;
4769 371 [ + - + + : 126895 : foreach(lc, bitjoinpaths)
+ + ]
372 : : {
373 : 69126 : Path *path = (Path *) lfirst(lc);
1880 374 [ + + ]: 69126 : Relids required_outer = PATH_REQ_OUTER(path);
375 : :
1028 376 : 69126 : all_path_outers = list_append_unique(all_path_outers,
377 : : required_outer);
378 : : }
379 : :
380 : : /* Now, for each distinct parameterization set ... */
4769 381 [ + - + + : 123664 : foreach(lc, all_path_outers)
+ + ]
382 : : {
383 : 65895 : Relids max_outers = (Relids) lfirst(lc);
384 : : List *this_path_set;
385 : : Path *bitmapqual;
386 : : Relids required_outer;
387 : : double loop_count;
388 : : BitmapHeapPath *bpath;
389 : : ListCell *lcp;
390 : :
391 : : /* Identify all the bitmap join paths needing no more than that */
392 : 65895 : this_path_set = NIL;
1880 393 [ + - + + : 157150 : foreach(lcp, bitjoinpaths)
+ + ]
394 : : {
4769 395 : 91255 : Path *path = (Path *) lfirst(lcp);
396 : :
1880 397 [ + + + + ]: 91255 : if (bms_is_subset(PATH_REQ_OUTER(path), max_outers))
4769 398 : 72636 : this_path_set = lappend(this_path_set, path);
399 : : }
400 : :
401 : : /*
402 : : * Add in restriction bitmap paths, since they can be used
403 : : * together with any join paths.
404 : : */
405 : 65895 : this_path_set = list_concat(this_path_set, bitindexpaths);
406 : :
407 : : /* Select best AND combination for this parameterization */
408 : 65895 : bitmapqual = choose_bitmap_and(root, rel, this_path_set);
409 : :
410 : : /* And push that path into the mix */
1880 411 [ + + ]: 65895 : required_outer = PATH_REQ_OUTER(bitmapqual);
3832 412 : 65895 : loop_count = get_loop_count(root, rel->relid, required_outer);
4769 413 : 65895 : bpath = create_bitmap_heap_path(root, rel, bitmapqual,
414 : : required_outer, loop_count, 0);
415 : 65895 : add_path(rel, (Path *) bpath);
416 : : }
417 : : }
418 : : }
419 : :
420 : : /*
421 : : * consider_index_join_clauses
422 : : * Given sets of join clauses for an index, decide which parameterized
423 : : * index paths to build.
424 : : *
425 : : * Plain indexpaths are sent directly to add_path, while potential
426 : : * bitmap indexpaths are added to *bitindexpaths for later processing.
427 : : *
428 : : * 'rel' is the index's heap relation
429 : : * 'index' is the index for which we want to generate paths
430 : : * 'rclauseset' is the collection of indexable restriction clauses
431 : : * 'jclauseset' is the collection of indexable simple join clauses
432 : : * 'eclauseset' is the collection of indexable clauses from EquivalenceClasses
433 : : * '*bitindexpaths' is the list to add bitmap paths to
434 : : */
435 : : static void
4971 436 : 62962 : consider_index_join_clauses(PlannerInfo *root, RelOptInfo *rel,
437 : : IndexOptInfo *index,
438 : : IndexClauseSet *rclauseset,
439 : : IndexClauseSet *jclauseset,
440 : : IndexClauseSet *eclauseset,
441 : : List **bitindexpaths)
442 : : {
4692 443 : 62962 : int considered_clauses = 0;
4738 444 : 62962 : List *considered_relids = NIL;
445 : : int indexcol;
446 : :
447 : : /*
448 : : * The strategy here is to identify every potentially useful set of outer
449 : : * rels that can provide indexable join clauses. For each such set,
450 : : * select all the join clauses available from those outer rels, add on all
451 : : * the indexable restriction clauses, and generate plain and/or bitmap
452 : : * index paths for that set of clauses. This is based on the assumption
453 : : * that it's always better to apply a clause as an indexqual than as a
454 : : * filter (qpqual); which is where an available clause would end up being
455 : : * applied if we omit it from the indexquals.
456 : : *
457 : : * This looks expensive, but in most practical cases there won't be very
458 : : * many distinct sets of outer rels to consider. As a safety valve when
459 : : * that's not true, we use a heuristic: limit the number of outer rel sets
460 : : * considered to a multiple of the number of clauses considered. (We'll
461 : : * always consider using each individual join clause, though.)
462 : : *
463 : : * For simplicity in selecting relevant clauses, we represent each set of
464 : : * outer rels as a maximum set of clause_relids --- that is, the indexed
465 : : * relation itself is also included in the relids set. considered_relids
466 : : * lists all relids sets we've already tried.
467 : : */
2398 468 [ + + ]: 156418 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
469 : : {
470 : : /* Consider each applicable simple join clause */
4692 471 : 93456 : considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
4738 472 : 93456 : consider_index_join_outer_rels(root, rel, index,
473 : : rclauseset, jclauseset, eclauseset,
474 : : bitindexpaths,
475 : : jclauseset->indexclauses[indexcol],
476 : : considered_clauses,
477 : : &considered_relids);
478 : : /* Consider each applicable eclass join clause */
4692 479 : 93456 : considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
4738 480 : 93456 : consider_index_join_outer_rels(root, rel, index,
481 : : rclauseset, jclauseset, eclauseset,
482 : : bitindexpaths,
483 : : eclauseset->indexclauses[indexcol],
484 : : considered_clauses,
485 : : &considered_relids);
486 : : }
487 : 62962 : }
488 : :
489 : : /*
490 : : * consider_index_join_outer_rels
491 : : * Generate parameterized paths based on clause relids in the clause list.
492 : : *
493 : : * Workhorse for consider_index_join_clauses; see notes therein for rationale.
494 : : *
495 : : * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset', and
496 : : * 'bitindexpaths' as above
497 : : * 'indexjoinclauses' is a list of IndexClauses for join clauses
498 : : * 'considered_clauses' is the total number of clauses considered (so far)
499 : : * '*considered_relids' is a list of all relids sets already considered
500 : : */
501 : : static void
502 : 186912 : consider_index_join_outer_rels(PlannerInfo *root, RelOptInfo *rel,
503 : : IndexOptInfo *index,
504 : : IndexClauseSet *rclauseset,
505 : : IndexClauseSet *jclauseset,
506 : : IndexClauseSet *eclauseset,
507 : : List **bitindexpaths,
508 : : List *indexjoinclauses,
509 : : int considered_clauses,
510 : : List **considered_relids)
511 : : {
512 : : ListCell *lc;
513 : :
514 : : /* Examine relids of each joinclause in the given list */
515 [ + + + + : 255731 : foreach(lc, indexjoinclauses)
+ + ]
516 : : {
2401 517 : 68819 : IndexClause *iclause = (IndexClause *) lfirst(lc);
518 : 68819 : Relids clause_relids = iclause->rinfo->clause_relids;
519 : 68819 : EquivalenceClass *parent_ec = iclause->rinfo->parent_ec;
520 : : int num_considered_relids;
521 : :
522 : : /* If we already tried its relids set, no need to do so again */
1028 523 [ + + ]: 68819 : if (list_member(*considered_relids, clause_relids))
4738 524 : 1406 : continue;
525 : :
526 : : /*
527 : : * Generate the union of this clause's relids set with each
528 : : * previously-tried set. This ensures we try this clause along with
529 : : * every interesting subset of previous clauses. However, to avoid
530 : : * exponential growth of planning time when there are many clauses,
531 : : * limit the number of relid sets accepted to 10 * considered_clauses.
532 : : *
533 : : * Note: get_join_index_paths appends entries to *considered_relids,
534 : : * but we do not need to visit such newly-added entries within this
535 : : * loop, so we don't use foreach() here. No real harm would be done
536 : : * if we did visit them, since the subset check would reject them; but
537 : : * it would waste some cycles.
538 : : */
2245 539 : 67413 : num_considered_relids = list_length(*considered_relids);
540 [ + + ]: 72047 : for (int pos = 0; pos < num_considered_relids; pos++)
541 : : {
542 : 4634 : Relids oldrelids = (Relids) list_nth(*considered_relids, pos);
543 : :
544 : : /*
545 : : * If either is a subset of the other, no new set is possible.
546 : : * This isn't a complete test for redundancy, but it's easy and
547 : : * cheap. get_join_index_paths will check more carefully if we
548 : : * already generated the same relids set.
549 : : */
4738 550 [ + + ]: 4634 : if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
551 : 12 : continue;
552 : :
553 : : /*
554 : : * If this clause was derived from an equivalence class, the
555 : : * clause list may contain other clauses derived from the same
556 : : * eclass. We should not consider that combining this clause with
557 : : * one of those clauses generates a usefully different
558 : : * parameterization; so skip if any clause derived from the same
559 : : * eclass would already have been included when using oldrelids.
560 : : */
2401 561 [ + + + + ]: 9163 : if (parent_ec &&
562 : 4541 : eclass_already_used(parent_ec, oldrelids,
563 : : indexjoinclauses))
4692 564 : 2909 : continue;
565 : :
566 : : /*
567 : : * If the number of relid sets considered exceeds our heuristic
568 : : * limit, stop considering combinations of clauses. We'll still
569 : : * consider the current clause alone, though (below this loop).
570 : : */
571 [ - + ]: 1713 : if (list_length(*considered_relids) >= 10 * considered_clauses)
4692 tgl@sss.pgh.pa.us 572 :UBC 0 : break;
573 : :
574 : : /* OK, try the union set */
4738 tgl@sss.pgh.pa.us 575 :CBC 1713 : get_join_index_paths(root, rel, index,
576 : : rclauseset, jclauseset, eclauseset,
577 : : bitindexpaths,
578 : : bms_union(clause_relids, oldrelids),
579 : : considered_relids);
580 : : }
581 : :
582 : : /* Also try this set of relids by itself */
583 : 67413 : get_join_index_paths(root, rel, index,
584 : : rclauseset, jclauseset, eclauseset,
585 : : bitindexpaths,
586 : : clause_relids,
587 : : considered_relids);
588 : : }
4971 589 : 186912 : }
590 : :
591 : : /*
592 : : * get_join_index_paths
593 : : * Generate index paths using clauses from the specified outer relations.
594 : : * In addition to generating paths, relids is added to *considered_relids
595 : : * if not already present.
596 : : *
597 : : * Workhorse for consider_index_join_clauses; see notes therein for rationale.
598 : : *
599 : : * 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset',
600 : : * 'bitindexpaths', 'considered_relids' as above
601 : : * 'relids' is the current set of relids to consider (the target rel plus
602 : : * one or more outer rels)
603 : : */
604 : : static void
4738 605 : 69126 : get_join_index_paths(PlannerInfo *root, RelOptInfo *rel,
606 : : IndexOptInfo *index,
607 : : IndexClauseSet *rclauseset,
608 : : IndexClauseSet *jclauseset,
609 : : IndexClauseSet *eclauseset,
610 : : List **bitindexpaths,
611 : : Relids relids,
612 : : List **considered_relids)
613 : : {
614 : : IndexClauseSet clauseset;
615 : : int indexcol;
616 : :
617 : : /* If we already considered this relids set, don't repeat the work */
1028 618 [ - + ]: 69126 : if (list_member(*considered_relids, relids))
4971 tgl@sss.pgh.pa.us 619 :UBC 0 : return;
620 : :
621 : : /* Identify indexclauses usable with this relids set */
4738 tgl@sss.pgh.pa.us 622 [ + - + - :CBC 2350284 : MemSet(&clauseset, 0, sizeof(clauseset));
+ - + - +
+ ]
623 : :
2398 624 [ + + ]: 174128 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
625 : : {
626 : : ListCell *lc;
627 : :
628 : : /* First find applicable simple join clauses */
4738 629 [ + + + + : 122657 : foreach(lc, jclauseset->indexclauses[indexcol])
+ + ]
630 : : {
2401 631 : 17655 : IndexClause *iclause = (IndexClause *) lfirst(lc);
632 : :
633 [ + + ]: 17655 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
4738 634 : 17442 : clauseset.indexclauses[indexcol] =
2401 635 : 17442 : lappend(clauseset.indexclauses[indexcol], iclause);
636 : : }
637 : :
638 : : /*
639 : : * Add applicable eclass join clauses. The clauses generated for each
640 : : * column are redundant (cf generate_implied_equalities_for_column),
641 : : * so we need at most one. This is the only exception to the general
642 : : * rule of using all available index clauses.
643 : : */
4738 644 [ + + + + : 111826 : foreach(lc, eclauseset->indexclauses[indexcol])
+ + ]
645 : : {
2401 646 : 61591 : IndexClause *iclause = (IndexClause *) lfirst(lc);
647 : :
648 [ + + ]: 61591 : if (bms_is_subset(iclause->rinfo->clause_relids, relids))
649 : : {
4738 650 : 54767 : clauseset.indexclauses[indexcol] =
2401 651 : 54767 : lappend(clauseset.indexclauses[indexcol], iclause);
4738 652 : 54767 : break;
653 : : }
654 : : }
655 : :
656 : : /* Add restriction clauses */
657 : 105002 : clauseset.indexclauses[indexcol] =
658 : 105002 : list_concat(clauseset.indexclauses[indexcol],
659 : 105002 : rclauseset->indexclauses[indexcol]);
660 : :
661 [ + + ]: 105002 : if (clauseset.indexclauses[indexcol] != NIL)
662 : 84704 : clauseset.nonempty = true;
663 : : }
664 : :
665 : : /* We should have found something, else caller passed silly relids */
666 [ - + ]: 69126 : Assert(clauseset.nonempty);
667 : :
668 : : /* Build index path(s) using the collected set of clauses */
669 : 69126 : get_index_paths(root, rel, index, &clauseset, bitindexpaths);
670 : :
671 : : /*
672 : : * Remember we considered paths for this set of relids.
673 : : */
2245 674 : 69126 : *considered_relids = lappend(*considered_relids, relids);
675 : : }
676 : :
677 : : /*
678 : : * eclass_already_used
679 : : * True if any join clause usable with oldrelids was generated from
680 : : * the specified equivalence class.
681 : : */
682 : : static bool
4692 683 : 4541 : eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids,
684 : : List *indexjoinclauses)
685 : : {
686 : : ListCell *lc;
687 : :
688 [ + - + + : 6404 : foreach(lc, indexjoinclauses)
+ + ]
689 : : {
2401 690 : 4772 : IndexClause *iclause = (IndexClause *) lfirst(lc);
691 : 4772 : RestrictInfo *rinfo = iclause->rinfo;
692 : :
4692 693 [ + - + + ]: 9544 : if (rinfo->parent_ec == parent_ec &&
694 : 4772 : bms_is_subset(rinfo->clause_relids, oldrelids))
695 : 2909 : return true;
696 : : }
697 : 1632 : return false;
698 : : }
699 : :
700 : :
701 : : /*
702 : : * get_index_paths
703 : : * Given an index and a set of index clauses for it, construct IndexPaths.
704 : : *
705 : : * Plain indexpaths are sent directly to add_path, while potential
706 : : * bitmap indexpaths are added to *bitindexpaths for later processing.
707 : : *
708 : : * This is a fairly simple frontend to build_index_paths(). Its reason for
709 : : * existence is mainly to handle ScalarArrayOpExpr quals properly. If the
710 : : * index AM supports them natively, we should just include them in simple
711 : : * index paths. If not, we should exclude them while building simple index
712 : : * paths, and then make a separate attempt to include them in bitmap paths.
713 : : */
714 : : static void
4971 715 : 418046 : get_index_paths(PlannerInfo *root, RelOptInfo *rel,
716 : : IndexOptInfo *index, IndexClauseSet *clauses,
717 : : List **bitindexpaths)
718 : : {
719 : : List *indexpaths;
3968 720 : 418046 : bool skip_nonnative_saop = false;
721 : : ListCell *lc;
722 : :
723 : : /*
724 : : * Build simple index paths using the clauses. Allow ScalarArrayOpExpr
725 : : * clauses only if the index AM supports them natively.
726 : : */
4971 727 : 418046 : indexpaths = build_index_paths(root, rel,
728 : : index, clauses,
729 : 418046 : index->predOK,
730 : : ST_ANYSCAN,
731 : : &skip_nonnative_saop);
732 : :
733 : : /*
734 : : * Submit all the ones that can form plain IndexScan plans to add_path. (A
735 : : * plain IndexPath can represent either a plain IndexScan or an
736 : : * IndexOnlyScan, but for our purposes here that distinction does not
737 : : * matter. However, some of the indexes might support only bitmap scans,
738 : : * and those we mustn't submit to add_path here.)
739 : : *
740 : : * Also, pick out the ones that are usable as bitmap scans. For that, we
741 : : * must discard indexes that don't support bitmap scans, and we also are
742 : : * only interested in paths that have some selectivity; we should discard
743 : : * anything that was generated solely for ordering purposes.
744 : : */
745 [ + + + + : 665587 : foreach(lc, indexpaths)
+ + ]
746 : : {
747 : 247541 : IndexPath *ipath = (IndexPath *) lfirst(lc);
748 : :
749 [ + + ]: 247541 : if (index->amhasgettuple)
6029 750 : 240648 : add_path(rel, (Path *) ipath);
751 : :
4971 752 [ + - ]: 247541 : if (index->amhasgetbitmap &&
5352 753 [ + + ]: 247541 : (ipath->path.pathkeys == NIL ||
754 [ + + ]: 150082 : ipath->indexselectivity < 1.0))
4971 755 : 181612 : *bitindexpaths = lappend(*bitindexpaths, ipath);
756 : : }
757 : :
758 : : /*
759 : : * If there were ScalarArrayOpExpr clauses that the index can't handle
760 : : * natively, generate bitmap scan paths relying on executor-managed
761 : : * ScalarArrayOpExpr.
762 : : */
3968 763 [ + + ]: 418046 : if (skip_nonnative_saop)
764 : : {
4971 765 : 16 : indexpaths = build_index_paths(root, rel,
766 : : index, clauses,
767 : : false,
768 : : ST_BITMAPSCAN,
769 : : NULL);
770 : 16 : *bitindexpaths = list_concat(*bitindexpaths, indexpaths);
771 : : }
772 : 418046 : }
773 : :
774 : : /*
775 : : * build_index_paths
776 : : * Given an index and a set of index clauses for it, construct zero
777 : : * or more IndexPaths. It also constructs zero or more partial IndexPaths.
778 : : *
779 : : * We return a list of paths because (1) this routine checks some cases
780 : : * that should cause us to not generate any IndexPath, and (2) in some
781 : : * cases we want to consider both a forward and a backward scan, so as
782 : : * to obtain both sort orders. Note that the paths are just returned
783 : : * to the caller and not immediately fed to add_path().
784 : : *
785 : : * At top level, useful_predicate should be exactly the index's predOK flag
786 : : * (ie, true if it has a predicate that was proven from the restriction
787 : : * clauses). When working on an arm of an OR clause, useful_predicate
788 : : * should be true if the predicate required the current OR list to be proven.
789 : : * Note that this routine should never be called at all if the index has an
790 : : * unprovable predicate.
791 : : *
792 : : * scantype indicates whether we want to create plain indexscans, bitmap
793 : : * indexscans, or both. When it's ST_BITMAPSCAN, we will not consider
794 : : * index ordering while deciding if a Path is worth generating.
795 : : *
796 : : * If skip_nonnative_saop is non-NULL, we ignore ScalarArrayOpExpr clauses
797 : : * unless the index AM supports them directly, and we set *skip_nonnative_saop
798 : : * to true if we found any such clauses (caller must initialize the variable
799 : : * to false). If it's NULL, we do not ignore ScalarArrayOpExpr clauses.
800 : : *
801 : : * 'rel' is the index's heap relation
802 : : * 'index' is the index for which we want to generate paths
803 : : * 'clauses' is the collection of indexable clauses (IndexClause nodes)
804 : : * 'useful_predicate' indicates whether the index has a useful predicate
805 : : * 'scantype' indicates whether we need plain or bitmap scan support
806 : : * 'skip_nonnative_saop' indicates whether to accept SAOP if index AM doesn't
807 : : */
808 : : static List *
809 : 419612 : build_index_paths(PlannerInfo *root, RelOptInfo *rel,
810 : : IndexOptInfo *index, IndexClauseSet *clauses,
811 : : bool useful_predicate,
812 : : ScanTypeControl scantype,
813 : : bool *skip_nonnative_saop)
814 : : {
815 : 419612 : List *result = NIL;
816 : : IndexPath *ipath;
817 : : List *index_clauses;
818 : : Relids outer_relids;
819 : : double loop_count;
820 : : List *orderbyclauses;
821 : : List *orderbyclausecols;
822 : : List *index_pathkeys;
823 : : List *useful_pathkeys;
824 : : bool pathkeys_possibly_useful;
825 : : bool index_is_ordered;
826 : : bool index_only_scan;
827 : : int indexcol;
828 : :
518 pg@bowt.ie 829 [ + + - + ]: 419612 : Assert(skip_nonnative_saop != NULL || scantype == ST_BITMAPSCAN);
830 : :
831 : : /*
832 : : * Check that index supports the desired scan type(s)
833 : : */
4971 tgl@sss.pgh.pa.us 834 [ - + + - ]: 419612 : switch (scantype)
835 : : {
4971 tgl@sss.pgh.pa.us 836 :UBC 0 : case ST_INDEXSCAN:
837 [ # # ]: 0 : if (!index->amhasgettuple)
838 : 0 : return NIL;
839 : 0 : break;
4971 tgl@sss.pgh.pa.us 840 :CBC 1566 : case ST_BITMAPSCAN:
841 [ - + ]: 1566 : if (!index->amhasgetbitmap)
4971 tgl@sss.pgh.pa.us 842 :UBC 0 : return NIL;
4971 tgl@sss.pgh.pa.us 843 :CBC 1566 : break;
844 : 418046 : case ST_ANYSCAN:
845 : : /* either or both are OK */
846 : 418046 : break;
847 : : }
848 : :
849 : : /*
850 : : * 1. Combine the per-column IndexClause lists into an overall list.
851 : : *
852 : : * In the resulting list, clauses are ordered by index key, so that the
853 : : * column numbers form a nondecreasing sequence. (This order is depended
854 : : * on by btree and possibly other places.) The list can be empty, if the
855 : : * index AM allows that.
856 : : *
857 : : * We also build a Relids set showing which outer rels are required by the
858 : : * selected clauses. Any lateral_relids are included in that, but not
859 : : * otherwise accounted for.
860 : : */
861 : 419612 : index_clauses = NIL;
4759 862 : 419612 : outer_relids = bms_copy(rel->lateral_relids);
2398 863 [ + + ]: 1194797 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
864 : : {
865 : : ListCell *lc;
866 : :
4971 867 [ + + + + : 986146 : foreach(lc, clauses->indexclauses[indexcol])
+ + ]
868 : : {
2401 869 : 210795 : IndexClause *iclause = (IndexClause *) lfirst(lc);
870 : 210795 : RestrictInfo *rinfo = iclause->rinfo;
871 : :
518 pg@bowt.ie 872 [ + + + + ]: 210795 : if (skip_nonnative_saop && !index->amsearcharray &&
873 [ + + ]: 10826 : IsA(rinfo->clause, ScalarArrayOpExpr))
874 : : {
875 : : /*
876 : : * Caller asked us to generate IndexPaths that omit any
877 : : * ScalarArrayOpExpr clauses when the underlying index AM
878 : : * lacks native support.
879 : : *
880 : : * We must omit this clause (and tell caller about it).
881 : : */
882 : 16 : *skip_nonnative_saop = true;
883 : 16 : continue;
884 : : }
885 : :
886 : : /* OK to include this clause */
2401 tgl@sss.pgh.pa.us 887 : 210779 : index_clauses = lappend(index_clauses, iclause);
4971 888 : 210779 : outer_relids = bms_add_members(outer_relids,
889 : 210779 : rinfo->clause_relids);
890 : : }
891 : :
892 : : /*
893 : : * If no clauses match the first index column, check for amoptionalkey
894 : : * restriction. We can't generate a scan over an index with
895 : : * amoptionalkey = false unless there's at least one index clause.
896 : : * (When working on columns after the first, this test cannot fail. It
897 : : * is always okay for columns after the first to not have any
898 : : * clauses.)
899 : : */
900 [ + + + + ]: 775351 : if (index_clauses == NIL && !index->amoptionalkey)
901 : 166 : return NIL;
902 : : }
903 : :
904 : : /* We do not want the index's rel itself listed in outer_relids */
905 : 419446 : outer_relids = bms_del_member(outer_relids, rel->relid);
906 : :
907 : : /* Compute loop_count for cost estimation purposes */
3832 908 : 419446 : loop_count = get_loop_count(root, rel->relid, outer_relids);
909 : :
910 : : /*
911 : : * 2. Compute pathkeys describing index's ordering, if any, then see how
912 : : * many of them are actually useful for this query. This is not relevant
913 : : * if we are only trying to build bitmap indexscans.
914 : : */
4971 915 [ + + + + ]: 837326 : pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN &&
916 : 417880 : has_useful_pathkeys(root, rel));
917 : 419446 : index_is_ordered = (index->sortopfamily != NULL);
918 [ + + + + ]: 419446 : if (index_is_ordered && pathkeys_possibly_useful)
919 : : {
920 : 311398 : index_pathkeys = build_index_pathkeys(root, index,
921 : : ForwardScanDirection);
922 : 311398 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
923 : : index_pathkeys);
924 : 311398 : orderbyclauses = NIL;
925 : 311398 : orderbyclausecols = NIL;
926 : : }
927 [ + + + + ]: 108048 : else if (index->amcanorderbyop && pathkeys_possibly_useful)
928 : : {
929 : : /*
930 : : * See if we can generate ordering operators for query_pathkeys or at
931 : : * least some prefix thereof. Matching to just a prefix of the
932 : : * query_pathkeys will allow an incremental sort to be considered on
933 : : * the index's partially sorted results.
934 : : */
935 : 537 : match_pathkeys_to_index(index, root->query_pathkeys,
936 : : &orderbyclauses,
937 : : &orderbyclausecols);
795 drowley@postgresql.o 938 [ + + ]: 1074 : if (list_length(root->query_pathkeys) == list_length(orderbyclauses))
4971 tgl@sss.pgh.pa.us 939 : 234 : useful_pathkeys = root->query_pathkeys;
940 : : else
795 drowley@postgresql.o 941 : 303 : useful_pathkeys = list_copy_head(root->query_pathkeys,
942 : : list_length(orderbyclauses));
943 : : }
944 : : else
945 : : {
4971 tgl@sss.pgh.pa.us 946 : 107511 : useful_pathkeys = NIL;
947 : 107511 : orderbyclauses = NIL;
948 : 107511 : orderbyclausecols = NIL;
949 : : }
950 : :
951 : : /*
952 : : * 3. Check if an index-only scan is possible. If we're not building
953 : : * plain indexscans, this isn't relevant since bitmap scans don't support
954 : : * index data retrieval anyway.
955 : : */
956 [ + + + + ]: 837326 : index_only_scan = (scantype != ST_BITMAPSCAN &&
957 : 417880 : check_index_only(rel, index));
958 : :
959 : : /*
960 : : * 4. Generate an indexscan path if there are relevant restriction clauses
961 : : * in the current clauses, OR the index ordering is potentially useful for
962 : : * later merging or final output ordering, OR the index has a useful
963 : : * predicate, OR an index-only scan is possible.
964 : : */
3968 965 [ + + + + : 419446 : if (index_clauses != NIL || useful_pathkeys != NIL || useful_predicate ||
+ + + + ]
966 : : index_only_scan)
967 : : {
4971 968 : 248800 : ipath = create_index_path(root, index,
969 : : index_clauses,
970 : : orderbyclauses,
971 : : orderbyclausecols,
972 : : useful_pathkeys,
973 : : ForwardScanDirection,
974 : : index_only_scan,
975 : : outer_relids,
976 : : loop_count,
977 : : false);
978 : 248800 : result = lappend(result, ipath);
979 : :
980 : : /*
981 : : * If appropriate, consider parallel index scan. We don't allow
982 : : * parallel index scan for bitmap index scans.
983 : : */
3121 rhaas@postgresql.org 984 [ + + ]: 248800 : if (index->amcanparallel &&
3125 985 [ + + + + : 238416 : rel->consider_parallel && outer_relids == NULL &&
+ + ]
986 : : scantype != ST_BITMAPSCAN)
987 : : {
988 : 132781 : ipath = create_index_path(root, index,
989 : : index_clauses,
990 : : orderbyclauses,
991 : : orderbyclausecols,
992 : : useful_pathkeys,
993 : : ForwardScanDirection,
994 : : index_only_scan,
995 : : outer_relids,
996 : : loop_count,
997 : : true);
998 : :
999 : : /*
1000 : : * if, after costing the path, we find that it's not worth using
1001 : : * parallel workers, just free it.
1002 : : */
1003 [ + + ]: 132781 : if (ipath->path.parallel_workers > 0)
1004 : 4972 : add_partial_path(rel, (Path *) ipath);
1005 : : else
1006 : 127809 : pfree(ipath);
1007 : : }
1008 : : }
1009 : :
1010 : : /*
1011 : : * 5. If the index is ordered, a backwards scan might be interesting.
1012 : : */
4971 tgl@sss.pgh.pa.us 1013 [ + + + + ]: 419446 : if (index_is_ordered && pathkeys_possibly_useful)
1014 : : {
1015 : 311398 : index_pathkeys = build_index_pathkeys(root, index,
1016 : : BackwardScanDirection);
1017 : 311398 : useful_pathkeys = truncate_useless_pathkeys(root, rel,
1018 : : index_pathkeys);
1019 [ + + ]: 311398 : if (useful_pathkeys != NIL)
1020 : : {
1021 : 307 : ipath = create_index_path(root, index,
1022 : : index_clauses,
1023 : : NIL,
1024 : : NIL,
1025 : : useful_pathkeys,
1026 : : BackwardScanDirection,
1027 : : index_only_scan,
1028 : : outer_relids,
1029 : : loop_count,
1030 : : false);
1031 : 307 : result = lappend(result, ipath);
1032 : :
1033 : : /* If appropriate, consider parallel index scan */
3121 rhaas@postgresql.org 1034 [ + - ]: 307 : if (index->amcanparallel &&
3125 1035 [ + + + + : 307 : rel->consider_parallel && outer_relids == NULL &&
+ - ]
1036 : : scantype != ST_BITMAPSCAN)
1037 : : {
1038 : 256 : ipath = create_index_path(root, index,
1039 : : index_clauses,
1040 : : NIL,
1041 : : NIL,
1042 : : useful_pathkeys,
1043 : : BackwardScanDirection,
1044 : : index_only_scan,
1045 : : outer_relids,
1046 : : loop_count,
1047 : : true);
1048 : :
1049 : : /*
1050 : : * if, after costing the path, we find that it's not worth
1051 : : * using parallel workers, just free it.
1052 : : */
1053 [ + + ]: 256 : if (ipath->path.parallel_workers > 0)
1054 : 84 : add_partial_path(rel, (Path *) ipath);
1055 : : else
1056 : 172 : pfree(ipath);
1057 : : }
1058 : : }
1059 : : }
1060 : :
4971 tgl@sss.pgh.pa.us 1061 : 419446 : return result;
1062 : : }
1063 : :
1064 : : /*
1065 : : * build_paths_for_OR
1066 : : * Given a list of restriction clauses from one arm of an OR clause,
1067 : : * construct all matching IndexPaths for the relation.
1068 : : *
1069 : : * Here we must scan all indexes of the relation, since a bitmap OR tree
1070 : : * can use multiple indexes.
1071 : : *
1072 : : * The caller actually supplies two lists of restriction clauses: some
1073 : : * "current" ones and some "other" ones. Both lists can be used freely
1074 : : * to match keys of the index, but an index must use at least one of the
1075 : : * "current" clauses to be considered usable. The motivation for this is
1076 : : * examples like
1077 : : * WHERE (x = 42) AND (... OR (y = 52 AND z = 77) OR ....)
1078 : : * While we are considering the y/z subclause of the OR, we can use "x = 42"
1079 : : * as one of the available index conditions; but we shouldn't match the
1080 : : * subclause to any index on x alone, because such a Path would already have
1081 : : * been generated at the upper level. So we could use an index on x,y,z
1082 : : * or an index on x,y for the OR subclause, but not an index on just x.
1083 : : * When dealing with a partial index, a match of the index predicate to
1084 : : * one of the "current" clauses also makes the index usable.
1085 : : *
1086 : : * 'rel' is the relation for which we want to generate index paths
1087 : : * 'clauses' is the current list of clauses (RestrictInfo nodes)
1088 : : * 'other_clauses' is the list of additional upper-level clauses
1089 : : */
1090 : : static List *
1091 : 5366 : build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel,
1092 : : List *clauses, List *other_clauses)
1093 : : {
7442 1094 : 5366 : List *result = NIL;
2999 1095 : 5366 : List *all_clauses = NIL; /* not computed till needed */
1096 : : ListCell *lc;
1097 : :
4971 1098 [ + - + + : 18679 : foreach(lc, rel->indexlist)
+ + ]
1099 : : {
1100 : 13313 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
1101 : : IndexClauseSet clauseset;
1102 : : List *indexpaths;
1103 : : bool useful_predicate;
1104 : :
1105 : : /* Ignore index if it doesn't support bitmap scans */
1106 [ - + ]: 13313 : if (!index->amhasgetbitmap)
5074 1107 : 11763 : continue;
1108 : :
1109 : : /*
1110 : : * Ignore partial indexes that do not match the query. If a partial
1111 : : * index is marked predOK then we know it's OK. Otherwise, we have to
1112 : : * test whether the added clauses are sufficient to imply the
1113 : : * predicate. If so, we can use the index in the current context.
1114 : : *
1115 : : * We set useful_predicate to true iff the predicate was proven using
1116 : : * the current set of clauses. This is needed to prevent matching a
1117 : : * predOK index to an arm of an OR, which would be a legal but
1118 : : * pointlessly inefficient plan. (A better plan will be generated by
1119 : : * just scanning the predOK index alone, no OR.)
1120 : : */
7345 1121 : 13313 : useful_predicate = false;
1122 [ + + ]: 13313 : if (index->indpred != NIL)
1123 : : {
1124 [ + + ]: 84 : if (index->predOK)
1125 : : {
1126 : : /* Usable, but don't set useful_predicate */
1127 : : }
1128 : : else
1129 : : {
1130 : : /* Form all_clauses if not done already */
1131 [ + + ]: 72 : if (all_clauses == NIL)
2217 1132 : 30 : all_clauses = list_concat_copy(clauses, other_clauses);
1133 : :
3006 rhaas@postgresql.org 1134 [ + + ]: 72 : if (!predicate_implied_by(index->indpred, all_clauses, false))
7266 bruce@momjian.us 1135 : 48 : continue; /* can't use it at all */
1136 : :
3006 rhaas@postgresql.org 1137 [ + - ]: 24 : if (!predicate_implied_by(index->indpred, other_clauses, false))
7345 tgl@sss.pgh.pa.us 1138 : 24 : useful_predicate = true;
1139 : : }
1140 : : }
1141 : :
1142 : : /*
1143 : : * Identify the restriction clauses that can match the index.
1144 : : */
4971 1145 [ + - + - : 451010 : MemSet(&clauseset, 0, sizeof(clauseset));
+ - + - +
+ ]
2399 1146 : 13265 : match_clauses_to_index(root, clauses, index, &clauseset);
1147 : :
1148 : : /*
1149 : : * If no matches so far, and the index predicate isn't useful, we
1150 : : * don't want it.
1151 : : */
4971 1152 [ + + + + ]: 13265 : if (!clauseset.nonempty && !useful_predicate)
7345 1153 : 11715 : continue;
1154 : :
1155 : : /*
1156 : : * Add "other" restriction clauses to the clauseset.
1157 : : */
2399 1158 : 1550 : match_clauses_to_index(root, other_clauses, index, &clauseset);
1159 : :
1160 : : /*
1161 : : * Construct paths if possible.
1162 : : */
4971 1163 : 1550 : indexpaths = build_index_paths(root, rel,
1164 : : index, &clauseset,
1165 : : useful_predicate,
1166 : : ST_BITMAPSCAN,
1167 : : NULL);
1168 : 1550 : result = list_concat(result, indexpaths);
1169 : : }
1170 : :
7442 1171 : 5366 : return result;
1172 : : }
1173 : :
1174 : : /*
1175 : : * Utility structure used to group similar OR-clause arguments in
1176 : : * group_similar_or_args(). It represents information about the OR-clause
1177 : : * argument and its matching index key.
1178 : : */
1179 : : typedef struct
1180 : : {
1181 : : int indexnum; /* index of the matching index, or -1 if no
1182 : : * matching index */
1183 : : int colnum; /* index of the matching column, or -1 if no
1184 : : * matching index */
1185 : : Oid opno; /* OID of the OpClause operator, or InvalidOid
1186 : : * if not an OpExpr */
1187 : : Oid inputcollid; /* OID of the OpClause input collation */
1188 : : int argindex; /* index of the clause in the list of
1189 : : * arguments */
1190 : : int groupindex; /* value of argindex for the fist clause in
1191 : : * the group of similar clauses */
1192 : : } OrArgIndexMatch;
1193 : :
1194 : : /*
1195 : : * Comparison function for OrArgIndexMatch which provides sort order placing
1196 : : * similar OR-clause arguments together.
1197 : : */
1198 : : static int
286 akorotkov@postgresql 1199 : 3544 : or_arg_index_match_cmp(const void *a, const void *b)
1200 : : {
1201 : 3544 : const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1202 : 3544 : const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1203 : :
1204 [ + + ]: 3544 : if (match_a->indexnum < match_b->indexnum)
1205 : 668 : return -1;
1206 [ + + ]: 2876 : else if (match_a->indexnum > match_b->indexnum)
1207 : 1525 : return 1;
1208 : :
1209 [ + + ]: 1351 : if (match_a->colnum < match_b->colnum)
1210 : 431 : return -1;
1211 [ + + ]: 920 : else if (match_a->colnum > match_b->colnum)
1212 : 12 : return 1;
1213 : :
1214 [ + + ]: 908 : if (match_a->opno < match_b->opno)
1215 : 9 : return -1;
1216 [ + + ]: 899 : else if (match_a->opno > match_b->opno)
1217 : 21 : return 1;
1218 : :
1219 [ - + ]: 878 : if (match_a->inputcollid < match_b->inputcollid)
286 akorotkov@postgresql 1220 :UBC 0 : return -1;
286 akorotkov@postgresql 1221 [ - + ]:CBC 878 : else if (match_a->inputcollid > match_b->inputcollid)
286 akorotkov@postgresql 1222 :UBC 0 : return 1;
1223 : :
286 akorotkov@postgresql 1224 [ + + ]:CBC 878 : if (match_a->argindex < match_b->argindex)
1225 : 839 : return -1;
1226 [ + - ]: 39 : else if (match_a->argindex > match_b->argindex)
1227 : 39 : return 1;
1228 : :
286 akorotkov@postgresql 1229 :UBC 0 : return 0;
1230 : : }
1231 : :
1232 : : /*
1233 : : * Another comparison function for OrArgIndexMatch. It sorts groups together
1234 : : * using groupindex. The group items are then sorted by argindex.
1235 : : */
1236 : : static int
162 akorotkov@postgresql 1237 :CBC 3595 : or_arg_index_match_cmp_group(const void *a, const void *b)
1238 : : {
1239 : 3595 : const OrArgIndexMatch *match_a = (const OrArgIndexMatch *) a;
1240 : 3595 : const OrArgIndexMatch *match_b = (const OrArgIndexMatch *) b;
1241 : :
1242 [ + + ]: 3595 : if (match_a->groupindex < match_b->groupindex)
1243 : 1749 : return -1;
1244 [ + + ]: 1846 : else if (match_a->groupindex > match_b->groupindex)
1245 : 1624 : return 1;
1246 : :
1247 [ + - ]: 222 : if (match_a->argindex < match_b->argindex)
1248 : 222 : return -1;
162 akorotkov@postgresql 1249 [ # # ]:UBC 0 : else if (match_a->argindex > match_b->argindex)
1250 : 0 : return 1;
1251 : :
1252 : 0 : return 0;
1253 : : }
1254 : :
1255 : : /*
1256 : : * group_similar_or_args
1257 : : * Transform incoming OR-restrictinfo into a list of sub-restrictinfos,
1258 : : * each of them containing a subset of similar OR-clause arguments from
1259 : : * the source rinfo.
1260 : : *
1261 : : * Similar OR-clause arguments are of the form "indexkey op constant" having
1262 : : * the same indexkey, operator, and collation. Constant may comprise either
1263 : : * Const or Param. It may be employed later, during the
1264 : : * match_clause_to_indexcol() to transform the whole OR-sub-rinfo to an SAOP
1265 : : * clause.
1266 : : *
1267 : : * Returns the processed list of OR-clause arguments.
1268 : : */
1269 : : static List *
286 akorotkov@postgresql 1270 :CBC 4489 : group_similar_or_args(PlannerInfo *root, RelOptInfo *rel, RestrictInfo *rinfo)
1271 : : {
1272 : : int n;
1273 : : int i;
1274 : : int group_start;
1275 : : OrArgIndexMatch *matches;
1276 : 4489 : bool matched = false;
1277 : : ListCell *lc;
1278 : : ListCell *lc2;
1279 : : List *orargs;
1280 : 4489 : List *result = NIL;
214 1281 : 4489 : Index relid = rel->relid;
1282 : :
286 1283 [ - + ]: 4489 : Assert(IsA(rinfo->orclause, BoolExpr));
1284 : 4489 : orargs = ((BoolExpr *) rinfo->orclause)->args;
1285 : 4489 : n = list_length(orargs);
1286 : :
1287 : : /*
1288 : : * To avoid N^2 behavior, take utility pass along the list of OR-clause
1289 : : * arguments. For each argument, fill the OrArgIndexMatch structure,
1290 : : * which will be used to sort these arguments at the next step.
1291 : : */
1292 : 4489 : i = -1;
1293 : 4489 : matches = (OrArgIndexMatch *) palloc(sizeof(OrArgIndexMatch) * n);
1294 [ + - + + : 15130 : foreach(lc, orargs)
+ + ]
1295 : : {
1296 : 10641 : Node *arg = lfirst(lc);
1297 : : RestrictInfo *argrinfo;
1298 : : OpExpr *clause;
1299 : : Oid opno;
1300 : : Node *leftop,
1301 : : *rightop;
1302 : : Node *nonConstExpr;
1303 : : int indexnum;
1304 : : int colnum;
1305 : :
1306 : 10641 : i++;
1307 : 10641 : matches[i].argindex = i;
162 1308 : 10641 : matches[i].groupindex = i;
286 1309 : 10641 : matches[i].indexnum = -1;
1310 : 10641 : matches[i].colnum = -1;
1311 : 10641 : matches[i].opno = InvalidOid;
1312 : 10641 : matches[i].inputcollid = InvalidOid;
1313 : :
1314 [ + + ]: 10641 : if (!IsA(arg, RestrictInfo))
1315 : 1181 : continue;
1316 : :
1317 : 9460 : argrinfo = castNode(RestrictInfo, arg);
1318 : :
1319 : : /* Only operator clauses can match */
1320 [ + + ]: 9460 : if (!IsA(argrinfo->clause, OpExpr))
1321 : 3782 : continue;
1322 : :
1323 : 5678 : clause = (OpExpr *) argrinfo->clause;
1324 : 5678 : opno = clause->opno;
1325 : :
1326 : : /* Only binary operators can match */
1327 [ - + ]: 5678 : if (list_length(clause->args) != 2)
286 akorotkov@postgresql 1328 :UBC 0 : continue;
1329 : :
1330 : : /*
1331 : : * Ignore any RelabelType node above the operands. This is needed to
1332 : : * be able to apply indexscanning in binary-compatible-operator cases.
1333 : : * Note: we can assume there is at most one RelabelType node;
1334 : : * eval_const_expressions() will have simplified if more than one.
1335 : : */
286 akorotkov@postgresql 1336 :CBC 5678 : leftop = get_leftop(clause);
1337 [ + + ]: 5678 : if (IsA(leftop, RelabelType))
1338 : 102 : leftop = (Node *) ((RelabelType *) leftop)->arg;
1339 : :
1340 : 5678 : rightop = get_rightop(clause);
1341 [ + + ]: 5678 : if (IsA(rightop, RelabelType))
1342 : 398 : rightop = (Node *) ((RelabelType *) rightop)->arg;
1343 : :
1344 : : /*
1345 : : * Check for clauses of the form: (indexkey operator constant) or
1346 : : * (constant operator indexkey). But we don't know a particular index
1347 : : * yet. Therefore, we try to distinguish the potential index key and
1348 : : * constant first, then search for a matching index key among all
1349 : : * indexes.
1350 : : */
214 1351 [ + + ]: 5678 : if (bms_is_member(relid, argrinfo->right_relids) &&
1352 [ + + ]: 980 : !bms_is_member(relid, argrinfo->left_relids) &&
1353 [ + - ]: 944 : !contain_volatile_functions(leftop))
1354 : : {
286 1355 : 944 : opno = get_commutator(opno);
1356 : :
1357 [ - + ]: 944 : if (!OidIsValid(opno))
1358 : : {
1359 : : /* commutator doesn't exist, we can't reverse the order */
286 akorotkov@postgresql 1360 :UBC 0 : continue;
1361 : : }
286 akorotkov@postgresql 1362 :CBC 944 : nonConstExpr = rightop;
1363 : : }
214 1364 [ + + ]: 4734 : else if (bms_is_member(relid, argrinfo->left_relids) &&
1365 [ + + ]: 3781 : !bms_is_member(relid, argrinfo->right_relids) &&
1366 [ + - ]: 3745 : !contain_volatile_functions(rightop))
1367 : : {
286 1368 : 3745 : nonConstExpr = leftop;
1369 : : }
1370 : : else
1371 : : {
1372 : 989 : continue;
1373 : : }
1374 : :
1375 : : /*
1376 : : * Match non-constant part to the index key. It's possible that a
1377 : : * single non-constant part matches multiple index keys. It's OK, we
1378 : : * just stop with first matching index key. Given that this choice is
1379 : : * determined the same for every clause, we will group similar clauses
1380 : : * together anyway.
1381 : : */
1382 : 4689 : indexnum = 0;
1383 [ + - + + : 10189 : foreach(lc2, rel->indexlist)
+ + ]
1384 : : {
1385 : 8357 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc2);
1386 : :
1387 : : /*
1388 : : * Ignore index if it doesn't support bitmap scans or SAOP
1389 : : * clauses.
1390 : : */
281 1391 [ + - + + ]: 8357 : if (!index->amhasgetbitmap || !index->amsearcharray)
286 1392 : 27 : continue;
1393 : :
1394 [ + + ]: 18860 : for (colnum = 0; colnum < index->nkeycolumns; colnum++)
1395 : : {
1396 [ + + ]: 13387 : if (match_index_to_operand(nonConstExpr, colnum, index))
1397 : : {
1398 : 2857 : matches[i].indexnum = indexnum;
1399 : 2857 : matches[i].colnum = colnum;
1400 : 2857 : matches[i].opno = opno;
1401 : 2857 : matches[i].inputcollid = clause->inputcollid;
1402 : 2857 : matched = true;
1403 : 2857 : break;
1404 : : }
1405 : : }
1406 : :
1407 : : /*
1408 : : * Stop looping through the indexes, if we managed to match
1409 : : * nonConstExpr to any index column.
1410 : : */
1411 [ + + ]: 8330 : if (matches[i].indexnum >= 0)
1412 : 2857 : break;
1413 : 5473 : indexnum++;
1414 : : }
1415 : : }
1416 : :
1417 : : /*
1418 : : * Fast-path check: if no clause is matching to the index column, we can
1419 : : * just give up at this stage and return the clause list as-is.
1420 : : */
1421 [ + + ]: 4489 : if (!matched)
1422 : : {
1423 : 2512 : pfree(matches);
1424 : 2512 : return orargs;
1425 : : }
1426 : :
1427 : : /*
1428 : : * Sort clauses to make similar clauses go together. But at the same
1429 : : * time, we would like to change the order of clauses as little as
1430 : : * possible. To do so, we reorder each group of similar clauses so that
1431 : : * the first item of the group stays in place, and all the other items are
1432 : : * moved after it. So, if there are no similar clauses, the order of
1433 : : * clauses stays the same. When there are some groups, required
1434 : : * reordering happens while the rest of the clauses remain in their
1435 : : * places. That is achieved by assigning a 'groupindex' to each clause:
1436 : : * the number of the first item in the group in the original clause list.
1437 : : */
1438 : 1977 : qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp);
1439 : :
1440 : : /* Assign groupindex to the sorted clauses */
162 1441 [ + + ]: 4736 : for (i = 1; i < n; i++)
1442 : : {
1443 : : /*
1444 : : * When two clauses are similar and should belong to the same group,
1445 : : * copy the 'groupindex' from the previous clause. Given we are
1446 : : * considering clauses in direct order, all the clauses would have a
1447 : : * 'groupindex' equal to the 'groupindex' of the first clause in the
1448 : : * group.
1449 : : */
1450 [ + + ]: 2759 : if (matches[i].indexnum == matches[i - 1].indexnum &&
1451 [ + + ]: 1270 : matches[i].colnum == matches[i - 1].colnum &&
1452 [ + + ]: 833 : matches[i].opno == matches[i - 1].opno &&
1453 [ + - ]: 809 : matches[i].inputcollid == matches[i - 1].inputcollid &&
1454 [ + + ]: 809 : matches[i].indexnum != -1)
1455 : 222 : matches[i].groupindex = matches[i - 1].groupindex;
1456 : : }
1457 : :
1458 : : /* Re-sort clauses first by groupindex then by argindex */
1459 : 1977 : qsort(matches, n, sizeof(OrArgIndexMatch), or_arg_index_match_cmp_group);
1460 : :
1461 : : /*
1462 : : * Group similar clauses into single sub-restrictinfo. Side effect: the
1463 : : * resulting list of restrictions will be sorted by indexnum and colnum.
1464 : : */
286 1465 : 1977 : group_start = 0;
1466 [ + + ]: 6713 : for (i = 1; i <= n; i++)
1467 : : {
1468 : : /* Check if it's a group boundary */
1469 [ + - + + ]: 4736 : if (group_start >= 0 &&
1470 : 2759 : (i == n ||
1471 [ + + ]: 2759 : matches[i].indexnum != matches[group_start].indexnum ||
1472 [ + + ]: 1234 : matches[i].colnum != matches[group_start].colnum ||
1473 [ + + ]: 806 : matches[i].opno != matches[group_start].opno ||
1474 [ + - ]: 785 : matches[i].inputcollid != matches[group_start].inputcollid ||
1475 [ + + ]: 785 : matches[i].indexnum == -1))
1476 : : {
1477 : : /*
1478 : : * One clause in group: add it "as is" to the upper-level OR.
1479 : : */
1480 [ + + ]: 4514 : if (i - group_start == 1)
1481 : : {
1482 : 4358 : result = lappend(result,
1483 : : list_nth(orargs,
1484 : 4358 : matches[group_start].argindex));
1485 : : }
1486 : : else
1487 : : {
1488 : : /*
1489 : : * Two or more clauses in a group: create a nested OR.
1490 : : */
1491 : 156 : List *args = NIL;
1492 : 156 : List *rargs = NIL;
1493 : : RestrictInfo *subrinfo;
1494 : : int j;
1495 : :
1496 [ - + ]: 156 : Assert(i - group_start >= 2);
1497 : :
1498 : : /* Construct the list of nested OR arguments */
1499 [ + + ]: 534 : for (j = group_start; j < i; j++)
1500 : : {
1501 : 378 : Node *arg = list_nth(orargs, matches[j].argindex);
1502 : :
1503 : 378 : rargs = lappend(rargs, arg);
1504 [ + - ]: 378 : if (IsA(arg, RestrictInfo))
1505 : 378 : args = lappend(args, ((RestrictInfo *) arg)->clause);
1506 : : else
286 akorotkov@postgresql 1507 :UBC 0 : args = lappend(args, arg);
1508 : : }
1509 : :
1510 : : /* Construct the nested OR and wrap it with RestrictInfo */
286 akorotkov@postgresql 1511 :CBC 156 : subrinfo = make_plain_restrictinfo(root,
1512 : : make_orclause(args),
1513 : : make_orclause(rargs),
1514 : 156 : rinfo->is_pushed_down,
1515 : 156 : rinfo->has_clone,
1516 : 156 : rinfo->is_clone,
1517 : 156 : rinfo->pseudoconstant,
1518 : : rinfo->security_level,
1519 : : rinfo->required_relids,
1520 : : rinfo->incompatible_relids,
1521 : : rinfo->outer_relids);
1522 : 156 : result = lappend(result, subrinfo);
1523 : : }
1524 : :
1525 : 4514 : group_start = i;
1526 : : }
1527 : : }
1528 : 1977 : pfree(matches);
1529 : 1977 : return result;
1530 : : }
1531 : :
1532 : : /*
1533 : : * make_bitmap_paths_for_or_group
1534 : : * Generate bitmap paths for a group of similar OR-clause arguments
1535 : : * produced by group_similar_or_args().
1536 : : *
1537 : : * This function considers two cases: (1) matching a group of clauses to
1538 : : * the index as a whole, and (2) matching the individual clauses one-by-one.
1539 : : * (1) typically comprises an optimal solution. If not, (2) typically
1540 : : * comprises fair alternative.
1541 : : *
1542 : : * Ideally, we could consider all arbitrary splits of arguments into
1543 : : * subgroups, but that could lead to unacceptable computational complexity.
1544 : : * This is why we only consider two cases of above.
1545 : : */
1546 : : static List *
1547 : 153 : make_bitmap_paths_for_or_group(PlannerInfo *root, RelOptInfo *rel,
1548 : : RestrictInfo *ri, List *other_clauses)
1549 : : {
1550 : 153 : List *jointlist = NIL;
1551 : 153 : List *splitlist = NIL;
1552 : : ListCell *lc;
1553 : : List *orargs;
1554 : 153 : List *args = ((BoolExpr *) ri->orclause)->args;
1555 : 153 : Cost jointcost = 0.0,
1556 : 153 : splitcost = 0.0;
1557 : : Path *bitmapqual;
1558 : : List *indlist;
1559 : :
1560 : : /*
1561 : : * First, try to match the whole group to the one index.
1562 : : */
1563 : 153 : orargs = list_make1(ri);
1564 : 153 : indlist = build_paths_for_OR(root, rel,
1565 : : orargs,
1566 : : other_clauses);
1567 [ + + ]: 153 : if (indlist != NIL)
1568 : : {
1569 : 150 : bitmapqual = choose_bitmap_and(root, rel, indlist);
1570 : 150 : jointcost = bitmapqual->total_cost;
1571 : 150 : jointlist = list_make1(bitmapqual);
1572 : : }
1573 : :
1574 : : /*
1575 : : * If we manage to find a bitmap scan, which uses the group of OR-clause
1576 : : * arguments as a whole, we can skip matching OR-clause arguments
1577 : : * one-by-one as long as there are no other clauses, which can bring more
1578 : : * efficiency to one-by-one case.
1579 : : */
1580 [ + + + + ]: 153 : if (jointlist != NIL && other_clauses == NIL)
1581 : 42 : return jointlist;
1582 : :
1583 : : /*
1584 : : * Also try to match all containing clauses one-by-one.
1585 : : */
1586 [ + - + + : 384 : foreach(lc, args)
+ + ]
1587 : : {
1588 : 276 : orargs = list_make1(lfirst(lc));
1589 : :
1590 : 276 : indlist = build_paths_for_OR(root, rel,
1591 : : orargs,
1592 : : other_clauses);
1593 : :
1594 [ + + ]: 276 : if (indlist == NIL)
1595 : : {
1596 : 3 : splitlist = NIL;
1597 : 3 : break;
1598 : : }
1599 : :
1600 : 273 : bitmapqual = choose_bitmap_and(root, rel, indlist);
1601 : 273 : splitcost += bitmapqual->total_cost;
1602 : 273 : splitlist = lappend(splitlist, bitmapqual);
1603 : : }
1604 : :
1605 : : /*
1606 : : * Pick the best option.
1607 : : */
1608 [ + + ]: 111 : if (splitlist == NIL)
1609 : 3 : return jointlist;
1610 [ - + ]: 108 : else if (jointlist == NIL)
286 akorotkov@postgresql 1611 :UBC 0 : return splitlist;
1612 : : else
286 akorotkov@postgresql 1613 [ + + ]:CBC 108 : return (jointcost < splitcost) ? jointlist : splitlist;
1614 : : }
1615 : :
1616 : :
1617 : : /*
1618 : : * generate_bitmap_or_paths
1619 : : * Look through the list of clauses to find OR clauses, and generate
1620 : : * a BitmapOrPath for each one we can handle that way. Return a list
1621 : : * of the generated BitmapOrPaths.
1622 : : *
1623 : : * other_clauses is a list of additional clauses that can be assumed true
1624 : : * for the purpose of generating indexquals, but are not to be searched for
1625 : : * ORs. (See build_paths_for_OR() for motivation.)
1626 : : */
1627 : : static List *
7398 tgl@sss.pgh.pa.us 1628 : 324094 : generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel,
1629 : : List *clauses, List *other_clauses)
1630 : : {
7442 1631 : 324094 : List *result = NIL;
1632 : : List *all_clauses;
1633 : : ListCell *lc;
1634 : :
1635 : : /*
1636 : : * We can use both the current and other clauses as context for
1637 : : * build_paths_for_OR; no need to remove ORs from the lists.
1638 : : */
2217 1639 : 324094 : all_clauses = list_concat_copy(clauses, other_clauses);
1640 : :
4971 1641 [ + + + + : 507378 : foreach(lc, clauses)
+ + ]
1642 : : {
3071 1643 : 183284 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1644 : : List *pathlist;
1645 : : Path *bitmapqual;
1646 : : ListCell *j;
1647 : : List *groupedArgs;
286 akorotkov@postgresql 1648 : 183284 : List *inner_other_clauses = NIL;
1649 : :
1650 : : /* Ignore RestrictInfos that aren't ORs */
7442 tgl@sss.pgh.pa.us 1651 [ + + ]: 183284 : if (!restriction_is_or_clause(rinfo))
1652 : 178795 : continue;
1653 : :
1654 : : /*
1655 : : * We must be able to match at least one index to each of the arms of
1656 : : * the OR, else we can't use it.
1657 : : */
1658 : 4489 : pathlist = NIL;
1659 : :
1660 : : /*
1661 : : * Group the similar OR-clause arguments into dedicated RestrictInfos,
1662 : : * because each of those RestrictInfos has a chance to match the index
1663 : : * as a whole.
1664 : : */
286 akorotkov@postgresql 1665 : 4489 : groupedArgs = group_similar_or_args(root, rel, rinfo);
1666 : :
1667 [ + + ]: 4489 : if (groupedArgs != ((BoolExpr *) rinfo->orclause)->args)
1668 : : {
1669 : : /*
1670 : : * Some parts of the rinfo were probably grouped. In this case,
1671 : : * we have a set of sub-rinfos that together are an exact
1672 : : * duplicate of rinfo. Thus, we need to remove the rinfo from
1673 : : * other clauses. match_clauses_to_index detects duplicated
1674 : : * iclauses by comparing pointers to original rinfos that would be
1675 : : * different. So, we must delete rinfo to avoid de-facto
1676 : : * duplicated clauses in the index clauses list.
1677 : : */
1678 : 1977 : inner_other_clauses = list_delete(list_copy(all_clauses), rinfo);
1679 : : }
1680 : :
1681 [ + - + + : 5598 : foreach(j, groupedArgs)
+ + ]
1682 : : {
7266 bruce@momjian.us 1683 : 5090 : Node *orarg = (Node *) lfirst(j);
1684 : : List *indlist;
1685 : :
1686 : : /* OR arguments should be ANDs or sub-RestrictInfos */
2412 tgl@sss.pgh.pa.us 1687 [ + + ]: 5090 : if (is_andclause(orarg))
1688 : : {
7266 bruce@momjian.us 1689 : 716 : List *andargs = ((BoolExpr *) orarg)->args;
1690 : :
4971 tgl@sss.pgh.pa.us 1691 : 716 : indlist = build_paths_for_OR(root, rel,
1692 : : andargs,
1693 : : all_clauses);
1694 : :
1695 : : /* Recurse in case there are sub-ORs */
7442 1696 : 716 : indlist = list_concat(indlist,
1697 : 716 : generate_bitmap_or_paths(root, rel,
1698 : : andargs,
1699 : : all_clauses));
1700 : : }
286 akorotkov@postgresql 1701 [ + + ]: 4374 : else if (restriction_is_or_clause(castNode(RestrictInfo, orarg)))
1702 : : {
1703 : 153 : RestrictInfo *ri = castNode(RestrictInfo, orarg);
1704 : :
1705 : : /*
1706 : : * Generate bitmap paths for the group of similar OR-clause
1707 : : * arguments.
1708 : : */
1709 : 153 : indlist = make_bitmap_paths_for_or_group(root,
1710 : : rel, ri,
1711 : : inner_other_clauses);
1712 : :
1713 [ + + ]: 153 : if (indlist == NIL)
1714 : : {
1715 : 3 : pathlist = NIL;
1716 : 3 : break;
1717 : : }
1718 : : else
1719 : : {
1720 : 150 : pathlist = list_concat(pathlist, indlist);
1721 : 150 : continue;
1722 : : }
1723 : : }
1724 : : else
1725 : : {
1067 drowley@postgresql.o 1726 : 4221 : RestrictInfo *ri = castNode(RestrictInfo, orarg);
1727 : : List *orargs;
1728 : :
1729 : 4221 : orargs = list_make1(ri);
1730 : :
4971 tgl@sss.pgh.pa.us 1731 : 4221 : indlist = build_paths_for_OR(root, rel,
1732 : : orargs,
1733 : : all_clauses);
1734 : : }
1735 : :
1736 : : /*
1737 : : * If nothing matched this arm, we can't do anything with this OR
1738 : : * clause.
1739 : : */
7442 1740 [ + + ]: 4937 : if (indlist == NIL)
1741 : : {
1742 : 3978 : pathlist = NIL;
1743 : 3978 : break;
1744 : : }
1745 : :
1746 : : /*
1747 : : * OK, pick the most promising AND combination, and add it to
1748 : : * pathlist.
1749 : : */
4971 1750 : 959 : bitmapqual = choose_bitmap_and(root, rel, indlist);
7442 1751 : 959 : pathlist = lappend(pathlist, bitmapqual);
1752 : : }
1753 : :
286 akorotkov@postgresql 1754 [ + + ]: 4489 : if (inner_other_clauses != NIL)
1755 : 1100 : list_free(inner_other_clauses);
1756 : :
1757 : : /*
1758 : : * If we have a match for every arm, then turn them into a
1759 : : * BitmapOrPath, and add to result list.
1760 : : */
7442 tgl@sss.pgh.pa.us 1761 [ + + ]: 4489 : if (pathlist != NIL)
1762 : : {
1763 : 508 : bitmapqual = (Path *) create_bitmap_or_path(root, rel, pathlist);
1764 : 508 : result = lappend(result, bitmapqual);
1765 : : }
1766 : : }
1767 : :
1768 : 324094 : return result;
1769 : : }
1770 : :
1771 : :
1772 : : /*
1773 : : * choose_bitmap_and
1774 : : * Given a nonempty list of bitmap paths, AND them into one path.
1775 : : *
1776 : : * This is a nontrivial decision since we can legally use any subset of the
1777 : : * given path set. We want to choose a good tradeoff between selectivity
1778 : : * and cost of computing the bitmap.
1779 : : *
1780 : : * The result is either a single one of the inputs, or a BitmapAndPath
1781 : : * combining multiple inputs.
1782 : : */
1783 : : static Path *
4971 1784 : 166675 : choose_bitmap_and(PlannerInfo *root, RelOptInfo *rel, List *paths)
1785 : : {
7441 1786 : 166675 : int npaths = list_length(paths);
1787 : : PathClauseUsage **pathinfoarray;
1788 : : PathClauseUsage *pathinfo;
1789 : : List *clauselist;
6717 1790 : 166675 : List *bestpaths = NIL;
1791 : 166675 : Cost bestcost = 0;
1792 : : int i,
1793 : : j;
1794 : : ListCell *l;
1795 : :
7266 bruce@momjian.us 1796 [ - + ]: 166675 : Assert(npaths > 0); /* else caller error */
7441 tgl@sss.pgh.pa.us 1797 [ + + ]: 166675 : if (npaths == 1)
2999 1798 : 128932 : return (Path *) linitial(paths); /* easy case */
1799 : :
1800 : : /*
1801 : : * In theory we should consider every nonempty subset of the given paths.
1802 : : * In practice that seems like overkill, given the crude nature of the
1803 : : * estimates, not to mention the possible effects of higher-level AND and
1804 : : * OR clauses. Moreover, it's completely impractical if there are a large
1805 : : * number of paths, since the work would grow as O(2^N).
1806 : : *
1807 : : * As a heuristic, we first check for paths using exactly the same sets of
1808 : : * WHERE clauses + index predicate conditions, and reject all but the
1809 : : * cheapest-to-scan in any such group. This primarily gets rid of indexes
1810 : : * that include the interesting columns but also irrelevant columns. (In
1811 : : * situations where the DBA has gone overboard on creating variant
1812 : : * indexes, this can make for a very large reduction in the number of
1813 : : * paths considered further.)
1814 : : *
1815 : : * We then sort the surviving paths with the cheapest-to-scan first, and
1816 : : * for each path, consider using that path alone as the basis for a bitmap
1817 : : * scan. Then we consider bitmap AND scans formed from that path plus
1818 : : * each subsequent (higher-cost) path, adding on a subsequent path if it
1819 : : * results in a reduction in the estimated total scan cost. This means we
1820 : : * consider about O(N^2) rather than O(2^N) path combinations, which is
1821 : : * quite tolerable, especially given than N is usually reasonably small
1822 : : * because of the prefiltering step. The cheapest of these is returned.
1823 : : *
1824 : : * We will only consider AND combinations in which no two indexes use the
1825 : : * same WHERE clause. This is a bit of a kluge: it's needed because
1826 : : * costsize.c and clausesel.c aren't very smart about redundant clauses.
1827 : : * They will usually double-count the redundant clauses, producing a
1828 : : * too-small selectivity that makes a redundant AND step look like it
1829 : : * reduces the total cost. Perhaps someday that code will be smarter and
1830 : : * we can remove this limitation. (But note that this also defends
1831 : : * against flat-out duplicate input paths, which can happen because
1832 : : * match_join_clauses_to_index will find the same OR join clauses that
1833 : : * extract_restriction_or_clauses has pulled OR restriction clauses out
1834 : : * of.)
1835 : : *
1836 : : * For the same reason, we reject AND combinations in which an index
1837 : : * predicate clause duplicates another clause. Here we find it necessary
1838 : : * to be even stricter: we'll reject a partial index if any of its
1839 : : * predicate clauses are implied by the set of WHERE clauses and predicate
1840 : : * clauses used so far. This covers cases such as a condition "x = 42"
1841 : : * used with a plain index, followed by a clauseless scan of a partial
1842 : : * index "WHERE x >= 40 AND x < 50". The partial index has been accepted
1843 : : * only because "x = 42" was present, and so allowing it would partially
1844 : : * double-count selectivity. (We could use predicate_implied_by on
1845 : : * regular qual clauses too, to have a more intelligent, but much more
1846 : : * expensive, check for redundancy --- but in most cases simple equality
1847 : : * seems to suffice.)
1848 : : */
1849 : :
1850 : : /*
1851 : : * Extract clause usage info and detect any paths that use exactly the
1852 : : * same set of clauses; keep only the cheapest-to-scan of any such groups.
1853 : : * The surviving paths are put into an array for qsort'ing.
1854 : : */
1855 : : pathinfoarray = (PathClauseUsage **)
6717 1856 : 37743 : palloc(npaths * sizeof(PathClauseUsage *));
1857 : 37743 : clauselist = NIL;
1858 : 37743 : npaths = 0;
7441 1859 [ + - + + : 124700 : foreach(l, paths)
+ + ]
1860 : : {
6505 bruce@momjian.us 1861 : 86957 : Path *ipath = (Path *) lfirst(l);
1862 : :
6717 tgl@sss.pgh.pa.us 1863 : 86957 : pathinfo = classify_index_clause_usage(ipath, &clauselist);
1864 : :
1865 : : /* If it's unclassifiable, treat it as distinct from all others */
2490 1866 [ - + ]: 86957 : if (pathinfo->unclassifiable)
1867 : : {
2490 tgl@sss.pgh.pa.us 1868 :UBC 0 : pathinfoarray[npaths++] = pathinfo;
1869 : 0 : continue;
1870 : : }
1871 : :
6717 tgl@sss.pgh.pa.us 1872 [ + + ]:CBC 136236 : for (i = 0; i < npaths; i++)
1873 : : {
2490 1874 [ + - + + ]: 121352 : if (!pathinfoarray[i]->unclassifiable &&
1875 : 60676 : bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
6717 1876 : 11397 : break;
1877 : : }
1878 [ + + ]: 86957 : if (i < npaths)
1879 : : {
1880 : : /* duplicate clauseids, keep the cheaper one */
1881 : : Cost ncost;
1882 : : Cost ocost;
1883 : : Selectivity nselec;
1884 : : Selectivity oselec;
1885 : :
1886 : 11397 : cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
1887 : 11397 : cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
1888 [ + + ]: 11397 : if (ncost < ocost)
1889 : 2603 : pathinfoarray[i] = pathinfo;
1890 : : }
1891 : : else
1892 : : {
1893 : : /* not duplicate clauseids, add to array */
1894 : 75560 : pathinfoarray[npaths++] = pathinfo;
1895 : : }
1896 : : }
1897 : :
1898 : : /* If only one surviving path, we're done */
1899 [ + + ]: 37743 : if (npaths == 1)
1900 : 7104 : return pathinfoarray[0]->path;
1901 : :
1902 : : /* Sort the surviving paths by index access cost */
1903 : 30639 : qsort(pathinfoarray, npaths, sizeof(PathClauseUsage *),
1904 : : path_usage_comparator);
1905 : :
1906 : : /*
1907 : : * For each surviving index, consider it as an "AND group leader", and see
1908 : : * whether adding on any of the later indexes results in an AND path with
1909 : : * cheaper total cost than before. Then take the cheapest AND group.
1910 : : *
1911 : : * Note: paths that are either clauseless or unclassifiable will have
1912 : : * empty clauseids, so that they will not be rejected by the clauseids
1913 : : * filter here, nor will they cause later paths to be rejected by it.
1914 : : */
1915 [ + + ]: 99095 : for (i = 0; i < npaths; i++)
1916 : : {
1917 : : Cost costsofar;
1918 : : List *qualsofar;
1919 : : Bitmapset *clauseidsofar;
1920 : :
1921 : 68456 : pathinfo = pathinfoarray[i];
1922 : 68456 : paths = list_make1(pathinfo->path);
4971 1923 : 68456 : costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
2217 1924 : 68456 : qualsofar = list_concat_copy(pathinfo->quals, pathinfo->preds);
6717 1925 : 68456 : clauseidsofar = bms_copy(pathinfo->clauseids);
1926 : :
6505 bruce@momjian.us 1927 [ + + ]: 113670 : for (j = i + 1; j < npaths; j++)
1928 : : {
1929 : : Cost newcost;
1930 : :
6717 tgl@sss.pgh.pa.us 1931 : 45214 : pathinfo = pathinfoarray[j];
1932 : : /* Check for redundancy */
1933 [ + + ]: 45214 : if (bms_overlap(pathinfo->clauseids, clauseidsofar))
6505 bruce@momjian.us 1934 : 20307 : continue; /* consider it redundant */
6717 tgl@sss.pgh.pa.us 1935 [ + + ]: 24907 : if (pathinfo->preds)
1936 : : {
6505 bruce@momjian.us 1937 : 12 : bool redundant = false;
1938 : :
1939 : : /* we check each predicate clause separately */
6717 tgl@sss.pgh.pa.us 1940 [ + - + - : 12 : foreach(l, pathinfo->preds)
+ - ]
1941 : : {
1942 : 12 : Node *np = (Node *) lfirst(l);
1943 : :
3006 rhaas@postgresql.org 1944 [ + - ]: 12 : if (predicate_implied_by(list_make1(np), qualsofar, false))
1945 : : {
6717 tgl@sss.pgh.pa.us 1946 : 12 : redundant = true;
6505 bruce@momjian.us 1947 : 12 : break; /* out of inner foreach loop */
1948 : : }
1949 : : }
6717 tgl@sss.pgh.pa.us 1950 [ + - ]: 12 : if (redundant)
1951 : 12 : continue;
1952 : : }
1953 : : /* tentatively add new path to paths, so we can estimate cost */
1954 : 24895 : paths = lappend(paths, pathinfo->path);
4971 1955 : 24895 : newcost = bitmap_and_cost_est(root, rel, paths);
6717 1956 [ + + ]: 24895 : if (newcost < costsofar)
1957 : : {
1958 : : /* keep new path in paths, update subsidiary variables */
1959 : 142 : costsofar = newcost;
2217 1960 : 142 : qualsofar = list_concat(qualsofar, pathinfo->quals);
1961 : 142 : qualsofar = list_concat(qualsofar, pathinfo->preds);
6717 1962 : 142 : clauseidsofar = bms_add_members(clauseidsofar,
1963 : 142 : pathinfo->clauseids);
1964 : : }
1965 : : else
1966 : : {
1967 : : /* reject new path, remove it from paths list */
2245 1968 : 24753 : paths = list_truncate(paths, list_length(paths) - 1);
1969 : : }
1970 : : }
1971 : :
1972 : : /* Keep the cheapest AND-group (or singleton) */
6717 1973 [ + + + + ]: 68456 : if (i == 0 || costsofar < bestcost)
1974 : : {
1975 : 32041 : bestpaths = paths;
1976 : 32041 : bestcost = costsofar;
1977 : : }
1978 : :
1979 : : /* some easy cleanup (we don't try real hard though) */
1980 : 68456 : list_free(qualsofar);
1981 : : }
1982 : :
1983 [ + + ]: 30639 : if (list_length(bestpaths) == 1)
6505 bruce@momjian.us 1984 : 30509 : return (Path *) linitial(bestpaths); /* no need for AND */
6717 tgl@sss.pgh.pa.us 1985 : 130 : return (Path *) create_bitmap_and_path(root, rel, bestpaths);
1986 : : }
1987 : :
1988 : : /* qsort comparator to sort in increasing index access cost order */
1989 : : static int
1990 : 41323 : path_usage_comparator(const void *a, const void *b)
1991 : : {
6505 bruce@momjian.us 1992 : 41323 : PathClauseUsage *pa = *(PathClauseUsage *const *) a;
1993 : 41323 : PathClauseUsage *pb = *(PathClauseUsage *const *) b;
1994 : : Cost acost;
1995 : : Cost bcost;
1996 : : Selectivity aselec;
1997 : : Selectivity bselec;
1998 : :
6717 tgl@sss.pgh.pa.us 1999 : 41323 : cost_bitmap_tree_node(pa->path, &acost, &aselec);
2000 : 41323 : cost_bitmap_tree_node(pb->path, &bcost, &bselec);
2001 : :
2002 : : /*
2003 : : * If costs are the same, sort by selectivity.
2004 : : */
2005 [ + + ]: 41323 : if (acost < bcost)
7441 2006 : 26845 : return -1;
6717 2007 [ + + ]: 14478 : if (acost > bcost)
7441 2008 : 9668 : return 1;
2009 : :
6717 2010 [ + + ]: 4810 : if (aselec < bselec)
7441 2011 : 1804 : return -1;
6717 2012 [ + + ]: 3006 : if (aselec > bselec)
7441 2013 : 1166 : return 1;
2014 : :
2015 : 1840 : return 0;
2016 : : }
2017 : :
2018 : : /*
2019 : : * Estimate the cost of actually executing a bitmap scan with a single
2020 : : * index path (which could be a BitmapAnd or BitmapOr node).
2021 : : */
2022 : : static Cost
4971 2023 : 93351 : bitmap_scan_cost_est(PlannerInfo *root, RelOptInfo *rel, Path *ipath)
2024 : : {
2025 : : BitmapHeapPath bpath;
2026 : :
2027 : : /* Set up a dummy BitmapHeapPath */
2028 : 93351 : bpath.path.type = T_BitmapHeapPath;
2029 : 93351 : bpath.path.pathtype = T_BitmapHeapScan;
2030 : 93351 : bpath.path.parent = rel;
3463 2031 : 93351 : bpath.path.pathtarget = rel->reltarget;
1880 2032 : 93351 : bpath.path.param_info = ipath->param_info;
4971 2033 : 93351 : bpath.path.pathkeys = NIL;
2034 : 93351 : bpath.bitmapqual = ipath;
2035 : :
2036 : : /*
2037 : : * Check the cost of temporary path without considering parallelism.
2038 : : * Parallel bitmap heap path will be considered at later stage.
2039 : : */
3104 rhaas@postgresql.org 2040 : 93351 : bpath.path.parallel_workers = 0;
2041 : :
2042 : : /* Now we can do cost_bitmap_heap_scan */
4888 tgl@sss.pgh.pa.us 2043 : 93351 : cost_bitmap_heap_scan(&bpath.path, root, rel,
2044 : : bpath.path.param_info,
2045 : : ipath,
2046 : : get_loop_count(root, rel->relid,
1880 2047 [ + + ]: 93351 : PATH_REQ_OUTER(ipath)));
2048 : :
4971 2049 : 93351 : return bpath.path.total_cost;
2050 : : }
2051 : :
2052 : : /*
2053 : : * Estimate the cost of actually executing a BitmapAnd scan with the given
2054 : : * inputs.
2055 : : */
2056 : : static Cost
2057 : 24895 : bitmap_and_cost_est(PlannerInfo *root, RelOptInfo *rel, List *paths)
2058 : : {
2059 : : BitmapAndPath *apath;
2060 : :
2061 : : /*
2062 : : * Might as well build a real BitmapAndPath here, as the work is slightly
2063 : : * too complicated to be worth repeating just to save one palloc.
2064 : : */
1880 2065 : 24895 : apath = create_bitmap_and_path(root, rel, paths);
2066 : :
2067 : 24895 : return bitmap_scan_cost_est(root, rel, (Path *) apath);
2068 : : }
2069 : :
2070 : :
2071 : : /*
2072 : : * classify_index_clause_usage
2073 : : * Construct a PathClauseUsage struct describing the WHERE clauses and
2074 : : * index predicate clauses used by the given indexscan path.
2075 : : * We consider two clauses the same if they are equal().
2076 : : *
2077 : : * At some point we might want to migrate this info into the Path data
2078 : : * structure proper, but for the moment it's only needed within
2079 : : * choose_bitmap_and().
2080 : : *
2081 : : * *clauselist is used and expanded as needed to identify all the distinct
2082 : : * clauses seen across successive calls. Caller must initialize it to NIL
2083 : : * before first call of a set.
2084 : : */
2085 : : static PathClauseUsage *
6717 2086 : 86957 : classify_index_clause_usage(Path *path, List **clauselist)
2087 : : {
2088 : : PathClauseUsage *result;
2089 : : Bitmapset *clauseids;
2090 : : ListCell *lc;
2091 : :
2092 : 86957 : result = (PathClauseUsage *) palloc(sizeof(PathClauseUsage));
2093 : 86957 : result->path = path;
2094 : :
2095 : : /* Recursively find the quals and preds used by the path */
2096 : 86957 : result->quals = NIL;
2097 : 86957 : result->preds = NIL;
2098 : 86957 : find_indexpath_quals(path, &result->quals, &result->preds);
2099 : :
2100 : : /*
2101 : : * Some machine-generated queries have outlandish numbers of qual clauses.
2102 : : * To avoid getting into O(N^2) behavior even in this preliminary
2103 : : * classification step, we want to limit the number of entries we can
2104 : : * accumulate in *clauselist. Treat any path with more than 100 quals +
2105 : : * preds as unclassifiable, which will cause calling code to consider it
2106 : : * distinct from all other paths.
2107 : : */
2490 2108 [ - + ]: 86957 : if (list_length(result->quals) + list_length(result->preds) > 100)
2109 : : {
2490 tgl@sss.pgh.pa.us 2110 :UBC 0 : result->clauseids = NULL;
2111 : 0 : result->unclassifiable = true;
2112 : 0 : return result;
2113 : : }
2114 : :
2115 : : /* Build up a bitmapset representing the quals and preds */
6717 tgl@sss.pgh.pa.us 2116 :CBC 86957 : clauseids = NULL;
2117 [ + + + + : 199037 : foreach(lc, result->quals)
+ + ]
2118 : : {
6505 bruce@momjian.us 2119 : 112080 : Node *node = (Node *) lfirst(lc);
2120 : :
6717 tgl@sss.pgh.pa.us 2121 : 112080 : clauseids = bms_add_member(clauseids,
2122 : : find_list_position(node, clauselist));
2123 : : }
2124 [ + + + + : 87104 : foreach(lc, result->preds)
+ + ]
2125 : : {
6505 bruce@momjian.us 2126 : 147 : Node *node = (Node *) lfirst(lc);
2127 : :
6717 tgl@sss.pgh.pa.us 2128 : 147 : clauseids = bms_add_member(clauseids,
2129 : : find_list_position(node, clauselist));
2130 : : }
2131 : 86957 : result->clauseids = clauseids;
2490 2132 : 86957 : result->unclassifiable = false;
2133 : :
6717 2134 : 86957 : return result;
2135 : : }
2136 : :
2137 : :
2138 : : /*
2139 : : * find_indexpath_quals
2140 : : *
2141 : : * Given the Path structure for a plain or bitmap indexscan, extract lists
2142 : : * of all the index clauses and index predicate conditions used in the Path.
2143 : : * These are appended to the initial contents of *quals and *preds (hence
2144 : : * caller should initialize those to NIL).
2145 : : *
2146 : : * Note we are not trying to produce an accurate representation of the AND/OR
2147 : : * semantics of the Path, but just find out all the base conditions used.
2148 : : *
2149 : : * The result lists contain pointers to the expressions used in the Path,
2150 : : * but all the list cells are freshly built, so it's safe to destructively
2151 : : * modify the lists (eg, by concat'ing with other lists).
2152 : : */
2153 : : static void
6744 2154 : 88114 : find_indexpath_quals(Path *bitmapqual, List **quals, List **preds)
2155 : : {
7090 2156 [ - + ]: 88114 : if (IsA(bitmapqual, BitmapAndPath))
2157 : : {
7090 tgl@sss.pgh.pa.us 2158 :UBC 0 : BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
2159 : : ListCell *l;
2160 : :
2161 [ # # # # : 0 : foreach(l, apath->bitmapquals)
# # ]
2162 : : {
6717 2163 : 0 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
2164 : : }
2165 : : }
7090 tgl@sss.pgh.pa.us 2166 [ + + ]:CBC 88114 : else if (IsA(bitmapqual, BitmapOrPath))
2167 : : {
2168 : 631 : BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
2169 : : ListCell *l;
2170 : :
2171 [ + - + + : 1788 : foreach(l, opath->bitmapquals)
+ + ]
2172 : : {
6717 2173 : 1157 : find_indexpath_quals((Path *) lfirst(l), quals, preds);
2174 : : }
2175 : : }
7090 2176 [ + - ]: 87483 : else if (IsA(bitmapqual, IndexPath))
2177 : : {
2178 : 87483 : IndexPath *ipath = (IndexPath *) bitmapqual;
2179 : : ListCell *l;
2180 : :
2401 2181 [ + + + + : 199563 : foreach(l, ipath->indexclauses)
+ + ]
2182 : : {
2183 : 112080 : IndexClause *iclause = (IndexClause *) lfirst(l);
2184 : :
2185 : 112080 : *quals = lappend(*quals, iclause->rinfo->clause);
2186 : : }
2217 2187 : 87483 : *preds = list_concat(*preds, ipath->indexinfo->indpred);
2188 : : }
2189 : : else
7090 tgl@sss.pgh.pa.us 2190 [ # # ]:UBC 0 : elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
7090 tgl@sss.pgh.pa.us 2191 :CBC 88114 : }
2192 : :
2193 : :
2194 : : /*
2195 : : * find_list_position
2196 : : * Return the given node's position (counting from 0) in the given
2197 : : * list of nodes. If it's not equal() to any existing list member,
2198 : : * add it at the end, and return that position.
2199 : : */
2200 : : static int
6717 2201 : 112227 : find_list_position(Node *node, List **nodelist)
2202 : : {
2203 : : int i;
2204 : : ListCell *lc;
2205 : :
2206 : 112227 : i = 0;
2207 [ + + + + : 177298 : foreach(lc, *nodelist)
+ + ]
2208 : : {
6505 bruce@momjian.us 2209 : 98263 : Node *oldnode = (Node *) lfirst(lc);
2210 : :
6717 tgl@sss.pgh.pa.us 2211 [ + + ]: 98263 : if (equal(node, oldnode))
2212 : 33192 : return i;
2213 : 65071 : i++;
2214 : : }
2215 : :
2216 : 79035 : *nodelist = lappend(*nodelist, node);
2217 : :
2218 : 79035 : return i;
2219 : : }
2220 : :
2221 : :
2222 : : /*
2223 : : * check_index_only
2224 : : * Determine whether an index-only scan is possible for this index.
2225 : : */
2226 : : static bool
5083 2227 : 417880 : check_index_only(RelOptInfo *rel, IndexOptInfo *index)
2228 : : {
2229 : : bool result;
2230 : 417880 : Bitmapset *attrs_used = NULL;
3817 heikki.linnakangas@i 2231 : 417880 : Bitmapset *index_canreturn_attrs = NULL;
2232 : : ListCell *lc;
2233 : : int i;
2234 : :
2235 : : /* Index-only scans must be enabled */
5083 tgl@sss.pgh.pa.us 2236 [ + + ]: 417880 : if (!enable_indexonlyscan)
2237 : 1845 : return false;
2238 : :
2239 : : /*
2240 : : * Check that all needed attributes of the relation are available from the
2241 : : * index.
2242 : : */
2243 : :
2244 : : /*
2245 : : * First, identify all the attributes needed for joins or final output.
2246 : : * Note: we must look at rel's targetlist, not the attr_needed data,
2247 : : * because attr_needed isn't computed for inheritance child rels.
2248 : : */
3463 2249 : 416035 : pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
2250 : :
2251 : : /*
2252 : : * Add all the attributes used by restriction clauses; but consider only
2253 : : * those clauses not implied by the index predicate, since ones that are
2254 : : * so implied don't need to be checked explicitly in the plan.
2255 : : *
2256 : : * Note: attributes used only in index quals would not be needed at
2257 : : * runtime either, if we are certain that the index is not lossy. However
2258 : : * it'd be complicated to account for that accurately, and it doesn't
2259 : : * matter in most cases, since we'd conclude that such attributes are
2260 : : * available from the index anyway.
2261 : : */
3446 2262 [ + + + + : 872417 : foreach(lc, index->indrestrictinfo)
+ + ]
2263 : : {
4836 bruce@momjian.us 2264 : 456382 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2265 : :
5083 tgl@sss.pgh.pa.us 2266 : 456382 : pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
2267 : : }
2268 : :
2269 : : /*
2270 : : * Construct a bitmapset of columns that the index can return back in an
2271 : : * index-only scan.
2272 : : */
2273 [ + + ]: 1186651 : for (i = 0; i < index->ncolumns; i++)
2274 : : {
4836 bruce@momjian.us 2275 : 770616 : int attno = index->indexkeys[i];
2276 : :
2277 : : /*
2278 : : * For the moment, we just ignore index expressions. It might be nice
2279 : : * to do something with them, later.
2280 : : */
5079 tgl@sss.pgh.pa.us 2281 [ + + ]: 770616 : if (attno == 0)
5083 2282 : 1643 : continue;
2283 : :
3817 heikki.linnakangas@i 2284 [ + + ]: 768973 : if (index->canreturn[i])
2285 : : index_canreturn_attrs =
2286 : 631210 : bms_add_member(index_canreturn_attrs,
2287 : : attno - FirstLowInvalidHeapAttributeNumber);
2288 : : }
2289 : :
2290 : : /* Do we have all the necessary attributes? */
2291 : 416035 : result = bms_is_subset(attrs_used, index_canreturn_attrs);
2292 : :
5083 tgl@sss.pgh.pa.us 2293 : 416035 : bms_free(attrs_used);
3817 heikki.linnakangas@i 2294 : 416035 : bms_free(index_canreturn_attrs);
2295 : :
5083 tgl@sss.pgh.pa.us 2296 : 416035 : return result;
2297 : : }
2298 : :
2299 : : /*
2300 : : * get_loop_count
2301 : : * Choose the loop count estimate to use for costing a parameterized path
2302 : : * with the given set of outer relids.
2303 : : *
2304 : : * Since we produce parameterized paths before we've begun to generate join
2305 : : * relations, it's impossible to predict exactly how many times a parameterized
2306 : : * path will be iterated; we don't know the size of the relation that will be
2307 : : * on the outside of the nestloop. However, we should try to account for
2308 : : * multiple iterations somehow in costing the path. The heuristic embodied
2309 : : * here is to use the rowcount of the smallest other base relation needed in
2310 : : * the join clauses used by the path. (We could alternatively consider the
2311 : : * largest one, but that seems too optimistic.) This is of course the right
2312 : : * answer for single-other-relation cases, and it seems like a reasonable
2313 : : * zero-order approximation for multiway-join cases.
2314 : : *
2315 : : * In addition, we check to see if the other side of each join clause is on
2316 : : * the inside of some semijoin that the current relation is on the outside of.
2317 : : * If so, the only way that a parameterized path could be used is if the
2318 : : * semijoin RHS has been unique-ified, so we should use the number of unique
2319 : : * RHS rows rather than using the relation's raw rowcount.
2320 : : *
2321 : : * Note: for this to work, allpaths.c must establish all baserel size
2322 : : * estimates before it begins to compute paths, or at least before it
2323 : : * calls create_index_paths().
2324 : : */
2325 : : static double
3832 2326 : 578692 : get_loop_count(PlannerInfo *root, Index cur_relid, Relids outer_relids)
2327 : : {
2328 : : double result;
2329 : : int outer_relid;
2330 : :
2331 : : /* For a non-parameterized path, just return 1.0 quickly */
2332 [ + + ]: 578692 : if (outer_relids == NULL)
2333 : 402040 : return 1.0;
2334 : :
2335 : 176652 : result = 0.0;
2336 : 176652 : outer_relid = -1;
2337 [ + + ]: 358789 : while ((outer_relid = bms_next_member(outer_relids, outer_relid)) >= 0)
2338 : : {
2339 : : RelOptInfo *outer_rel;
2340 : : double rowcount;
2341 : :
2342 : : /* Paranoia: ignore bogus relid indexes */
2343 [ - + ]: 182137 : if (outer_relid >= root->simple_rel_array_size)
3832 tgl@sss.pgh.pa.us 2344 :UBC 0 : continue;
3832 tgl@sss.pgh.pa.us 2345 :CBC 182137 : outer_rel = root->simple_rel_array[outer_relid];
2346 [ + + ]: 182137 : if (outer_rel == NULL)
2347 : 127 : continue;
2999 2348 [ - + ]: 182010 : Assert(outer_rel->relid == outer_relid); /* sanity check on array */
2349 : :
2350 : : /* Other relation could be proven empty, if so ignore */
3832 2351 [ + + ]: 182010 : if (IS_DUMMY_REL(outer_rel))
2352 : 12 : continue;
2353 : :
2354 : : /* Otherwise, rel's rows estimate should be valid by now */
2355 [ - + ]: 181998 : Assert(outer_rel->rows > 0);
2356 : :
2357 : : /* Check to see if rel is on the inside of any semijoins */
2358 : 181998 : rowcount = adjust_rowcount_for_semijoins(root,
2359 : : cur_relid,
2360 : : outer_relid,
2361 : : outer_rel->rows);
2362 : :
2363 : : /* Remember smallest row count estimate among the outer rels */
2364 [ + + + + ]: 181998 : if (result == 0.0 || result > rowcount)
2365 : 180168 : result = rowcount;
2366 : : }
2367 : : /* Return 1.0 if we found no valid relations (shouldn't happen) */
2368 [ + + ]: 176652 : return (result > 0.0) ? result : 1.0;
2369 : : }
2370 : :
2371 : : /*
2372 : : * Check to see if outer_relid is on the inside of any semijoin that cur_relid
2373 : : * is on the outside of. If so, replace rowcount with the estimated number of
2374 : : * unique rows from the semijoin RHS (assuming that's smaller, which it might
2375 : : * not be). The estimate is crude but it's the best we can do at this stage
2376 : : * of the proceedings.
2377 : : */
2378 : : static double
2379 : 181998 : adjust_rowcount_for_semijoins(PlannerInfo *root,
2380 : : Index cur_relid,
2381 : : Index outer_relid,
2382 : : double rowcount)
2383 : : {
2384 : : ListCell *lc;
2385 : :
2386 [ + + + + : 292458 : foreach(lc, root->join_info_list)
+ + ]
2387 : : {
2388 : 110460 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
2389 : :
2390 [ + + + + ]: 114586 : if (sjinfo->jointype == JOIN_SEMI &&
2391 [ + + ]: 5941 : bms_is_member(cur_relid, sjinfo->syn_lefthand) &&
2392 : 1815 : bms_is_member(outer_relid, sjinfo->syn_righthand))
2393 : : {
2394 : : /* Estimate number of unique-ified rows */
2395 : : double nraw;
2396 : : double nunique;
2397 : :
2398 : 668 : nraw = approximate_joinrel_size(root, sjinfo->syn_righthand);
2399 : 668 : nunique = estimate_num_groups(root,
2400 : : sjinfo->semi_rhs_exprs,
2401 : : nraw,
2402 : : NULL,
2403 : : NULL);
2404 [ + + ]: 668 : if (rowcount > nunique)
2405 : 225 : rowcount = nunique;
2406 : : }
2407 : : }
2408 : 181998 : return rowcount;
2409 : : }
2410 : :
2411 : : /*
2412 : : * Make an approximate estimate of the size of a joinrel.
2413 : : *
2414 : : * We don't have enough info at this point to get a good estimate, so we
2415 : : * just multiply the base relation sizes together. Fortunately, this is
2416 : : * the right answer anyway for the most common case with a single relation
2417 : : * on the RHS of a semijoin. Also, estimate_num_groups() has only a weak
2418 : : * dependency on its input_rows argument (it basically uses it as a clamp).
2419 : : * So we might be able to get a fairly decent end result even with a severe
2420 : : * overestimate of the RHS's raw size.
2421 : : */
2422 : : static double
2423 : 668 : approximate_joinrel_size(PlannerInfo *root, Relids relids)
2424 : : {
2425 : 668 : double rowcount = 1.0;
2426 : : int relid;
2427 : :
2428 : 668 : relid = -1;
2429 [ + + ]: 1438 : while ((relid = bms_next_member(relids, relid)) >= 0)
2430 : : {
2431 : : RelOptInfo *rel;
2432 : :
2433 : : /* Paranoia: ignore bogus relid indexes */
2434 [ - + ]: 770 : if (relid >= root->simple_rel_array_size)
3832 tgl@sss.pgh.pa.us 2435 :UBC 0 : continue;
3832 tgl@sss.pgh.pa.us 2436 :CBC 770 : rel = root->simple_rel_array[relid];
2437 [ - + ]: 770 : if (rel == NULL)
3832 tgl@sss.pgh.pa.us 2438 :UBC 0 : continue;
3832 tgl@sss.pgh.pa.us 2439 [ - + ]:CBC 770 : Assert(rel->relid == relid); /* sanity check on array */
2440 : :
2441 : : /* Relation could be proven empty, if so ignore */
2442 [ - + ]: 770 : if (IS_DUMMY_REL(rel))
3832 tgl@sss.pgh.pa.us 2443 :UBC 0 : continue;
2444 : :
2445 : : /* Otherwise, rel's rows estimate should be valid by now */
3832 tgl@sss.pgh.pa.us 2446 [ - + ]:CBC 770 : Assert(rel->rows > 0);
2447 : :
2448 : : /* Accumulate product */
2449 : 770 : rowcount *= rel->rows;
2450 : : }
2451 : 668 : return rowcount;
2452 : : }
2453 : :
2454 : :
2455 : : /****************************************************************************
2456 : : * ---- ROUTINES TO CHECK QUERY CLAUSES ----
2457 : : ****************************************************************************/
2458 : :
2459 : : /*
2460 : : * match_restriction_clauses_to_index
2461 : : * Identify restriction clauses for the rel that match the index.
2462 : : * Matching clauses are added to *clauseset.
2463 : : */
2464 : : static void
2399 2465 : 348920 : match_restriction_clauses_to_index(PlannerInfo *root,
2466 : : IndexOptInfo *index,
2467 : : IndexClauseSet *clauseset)
2468 : : {
2469 : : /* We can ignore clauses that are implied by the index predicate */
2470 : 348920 : match_clauses_to_index(root, index->indrestrictinfo, index, clauseset);
4971 2471 : 348920 : }
2472 : :
2473 : : /*
2474 : : * match_join_clauses_to_index
2475 : : * Identify join clauses for the rel that match the index.
2476 : : * Matching clauses are added to *clauseset.
2477 : : * Also, add any potentially usable join OR clauses to *joinorclauses.
2478 : : * They also might be processed by match_clause_to_index() as a whole.
2479 : : */
2480 : : static void
2481 : 348920 : match_join_clauses_to_index(PlannerInfo *root,
2482 : : RelOptInfo *rel, IndexOptInfo *index,
2483 : : IndexClauseSet *clauseset,
2484 : : List **joinorclauses)
2485 : : {
2486 : : ListCell *lc;
2487 : :
2488 : : /* Scan the rel's join clauses */
2489 [ + + + + : 474013 : foreach(lc, rel->joininfo)
+ + ]
2490 : : {
2491 : 125093 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2492 : :
2493 : : /* Check if clause can be moved to this rel */
4403 2494 [ + + ]: 125093 : if (!join_clause_is_movable_to(rinfo, rel))
4755 2495 : 76523 : continue;
2496 : :
2497 : : /*
2498 : : * Potentially usable, so see if it matches the index or is an OR. Use
2499 : : * list_append_unique_ptr() here to avoid possible duplicates when
2500 : : * processing the same clauses with different indexes.
2501 : : */
4971 2502 [ + + ]: 48570 : if (restriction_is_or_clause(rinfo))
214 akorotkov@postgresql 2503 : 6617 : *joinorclauses = list_append_unique_ptr(*joinorclauses, rinfo);
2504 : :
2505 : 48570 : match_clause_to_index(root, rinfo, index, clauseset);
2506 : : }
4971 tgl@sss.pgh.pa.us 2507 : 348920 : }
2508 : :
2509 : : /*
2510 : : * match_eclass_clauses_to_index
2511 : : * Identify EquivalenceClass join clauses for the rel that match the index.
2512 : : * Matching clauses are added to *clauseset.
2513 : : */
2514 : : static void
2515 : 348920 : match_eclass_clauses_to_index(PlannerInfo *root, IndexOptInfo *index,
2516 : : IndexClauseSet *clauseset)
2517 : : {
2518 : : int indexcol;
2519 : :
2520 : : /* No work if rel is not in any such ECs */
2521 [ + + ]: 348920 : if (!index->rel->has_eclass_joins)
2522 : 205546 : return;
2523 : :
2709 teodor@sigaev.ru 2524 [ + + ]: 374892 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2525 : : {
2526 : : ec_member_matches_arg arg;
2527 : : List *clauses;
2528 : :
2529 : : /* Generate clauses, skipping any that join to lateral_referencers */
4552 tgl@sss.pgh.pa.us 2530 : 231518 : arg.index = index;
2531 : 231518 : arg.indexcol = indexcol;
2532 : 231518 : clauses = generate_implied_equalities_for_column(root,
2533 : : index->rel,
2534 : : ec_member_matches_indexcol,
2535 : : &arg,
2999 2536 : 231518 : index->rel->lateral_referencers);
2537 : :
2538 : : /*
2539 : : * We have to check whether the results actually do match the index,
2540 : : * since for non-btree indexes the EC's equality operators might not
2541 : : * be in the index opclass (cf ec_member_matches_indexcol).
2542 : : */
2399 2543 : 231518 : match_clauses_to_index(root, clauses, index, clauseset);
2544 : : }
2545 : : }
2546 : :
2547 : : /*
2548 : : * match_clauses_to_index
2549 : : * Perform match_clause_to_index() for each clause in a list.
2550 : : * Matching clauses are added to *clauseset.
2551 : : */
2552 : : static void
2553 : 595253 : match_clauses_to_index(PlannerInfo *root,
2554 : : List *clauses,
2555 : : IndexOptInfo *index,
2556 : : IndexClauseSet *clauseset)
2557 : : {
2558 : : ListCell *lc;
2559 : :
4971 2560 [ + + + + : 1078379 : foreach(lc, clauses)
+ + ]
2561 : : {
3071 2562 : 483126 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
2563 : :
2399 2564 : 483126 : match_clause_to_index(root, rinfo, index, clauseset);
2565 : : }
4971 2566 : 595253 : }
2567 : :
2568 : : /*
2569 : : * match_clause_to_index
2570 : : * Test whether a qual clause can be used with an index.
2571 : : *
2572 : : * If the clause is usable, add an IndexClause entry for it to the appropriate
2573 : : * list in *clauseset. (*clauseset must be initialized to zeroes before first
2574 : : * call.)
2575 : : *
2576 : : * Note: in some circumstances we may find the same RestrictInfos coming from
2577 : : * multiple places. Defend against redundant outputs by refusing to add a
2578 : : * clause twice (pointer equality should be a good enough check for this).
2579 : : *
2580 : : * Note: it's possible that a badly-defined index could have multiple matching
2581 : : * columns. We always select the first match if so; this avoids scenarios
2582 : : * wherein we get an inflated idea of the index's selectivity by using the
2583 : : * same clause multiple times with different index columns.
2584 : : */
2585 : : static void
2399 2586 : 531696 : match_clause_to_index(PlannerInfo *root,
2587 : : RestrictInfo *rinfo,
2588 : : IndexOptInfo *index,
2589 : : IndexClauseSet *clauseset)
2590 : : {
2591 : : int indexcol;
2592 : :
2593 : : /*
2594 : : * Never match pseudoconstants to indexes. (Normally a match could not
2595 : : * happen anyway, since a pseudoconstant clause couldn't contain a Var,
2596 : : * but what if someone builds an expression index on a constant? It's not
2597 : : * totally unreasonable to do so with a partial index, either.)
2598 : : */
3153 2599 [ + + ]: 531696 : if (rinfo->pseudoconstant)
2600 : 6578 : return;
2601 : :
2602 : : /*
2603 : : * If clause can't be used as an indexqual because it must wait till after
2604 : : * some lower-security-level restriction clause, reject it.
2605 : : */
2606 [ + + ]: 525118 : if (!restriction_is_securely_promotable(rinfo, index->rel))
2607 : 237 : return;
2608 : :
2609 : : /* OK, check each index key column for a match */
2708 teodor@sigaev.ru 2610 [ + + ]: 1166520 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
2611 : : {
2612 : : IndexClause *iclause;
2613 : : ListCell *lc;
2614 : :
2615 : : /* Ignore duplicates */
2401 tgl@sss.pgh.pa.us 2616 [ + + + + : 871424 : foreach(lc, clauseset->indexclauses[indexcol])
+ + ]
2617 : : {
1107 drowley@postgresql.o 2618 : 35276 : iclause = (IndexClause *) lfirst(lc);
2619 : :
2401 tgl@sss.pgh.pa.us 2620 [ - + ]: 35276 : if (iclause->rinfo == rinfo)
2401 tgl@sss.pgh.pa.us 2621 :UBC 0 : return;
2622 : : }
2623 : :
2624 : : /* OK, try to match the clause to the index column */
2399 tgl@sss.pgh.pa.us 2625 :CBC 836148 : iclause = match_clause_to_indexcol(root,
2626 : : rinfo,
2627 : : indexcol,
2628 : : index);
2629 [ + + ]: 836148 : if (iclause)
2630 : : {
2631 : : /* Success, so record it */
4971 2632 : 194509 : clauseset->indexclauses[indexcol] =
2401 2633 : 194509 : lappend(clauseset->indexclauses[indexcol], iclause);
4971 2634 : 194509 : clauseset->nonempty = true;
5005 2635 : 194509 : return;
2636 : : }
2637 : : }
2638 : : }
2639 : :
2640 : : /*
2641 : : * match_clause_to_indexcol()
2642 : : * Determine whether a restriction clause matches a column of an index,
2643 : : * and if so, build an IndexClause node describing the details.
2644 : : *
2645 : : * To match an index normally, an operator clause:
2646 : : *
2647 : : * (1) must be in the form (indexkey op const) or (const op indexkey);
2648 : : * and
2649 : : * (2) must contain an operator which is in the index's operator family
2650 : : * for this column; and
2651 : : * (3) must match the collation of the index, if collation is relevant.
2652 : : *
2653 : : * Our definition of "const" is exceedingly liberal: we allow anything that
2654 : : * doesn't involve a volatile function or a Var of the index's relation.
2655 : : * In particular, Vars belonging to other relations of the query are
2656 : : * accepted here, since a clause of that form can be used in a
2657 : : * parameterized indexscan. It's the responsibility of higher code levels
2658 : : * to manage restriction and join clauses appropriately.
2659 : : *
2660 : : * Note: we do need to check for Vars of the index's relation on the
2661 : : * "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
2662 : : * are not processable by a parameterized indexscan on a.f1, whereas
2663 : : * something like (a.f1 OP (b.f2 OP c.f3)) is.
2664 : : *
2665 : : * Presently, the executor can only deal with indexquals that have the
2666 : : * indexkey on the left, so we can only use clauses that have the indexkey
2667 : : * on the right if we can commute the clause to put the key on the left.
2668 : : * We handle that by generating an IndexClause with the correctly-commuted
2669 : : * opclause as a derived indexqual.
2670 : : *
2671 : : * If the index has a collation, the clause must have the same collation.
2672 : : * For collation-less indexes, we assume it doesn't matter; this is
2673 : : * necessary for cases like "hstore ? text", wherein hstore's operators
2674 : : * don't care about collation but the clause will get marked with a
2675 : : * collation anyway because of the text argument. (This logic is
2676 : : * embodied in the macro IndexCollMatchesExprColl.)
2677 : : *
2678 : : * It is also possible to match RowCompareExpr clauses to indexes (but
2679 : : * currently, only btree indexes handle this).
2680 : : *
2681 : : * It is also possible to match ScalarArrayOpExpr clauses to indexes, when
2682 : : * the clause is of the form "indexkey op ANY (arrayconst)".
2683 : : *
2684 : : * It is also possible to match a list of OR clauses if it might be
2685 : : * transformed into a single ScalarArrayOpExpr clause. On success,
2686 : : * the returning index clause will contain a transformed clause.
2687 : : *
2688 : : * For boolean indexes, it is also possible to match the clause directly
2689 : : * to the indexkey; or perhaps the clause is (NOT indexkey).
2690 : : *
2691 : : * And, last but not least, some operators and functions can be processed
2692 : : * to derive (typically lossy) indexquals from a clause that isn't in
2693 : : * itself indexable. If we see that any operand of an OpExpr or FuncExpr
2694 : : * matches the index key, and the function has a planner support function
2695 : : * attached to it, we'll invoke the support function to see if such an
2696 : : * indexqual can be built.
2697 : : *
2698 : : * 'rinfo' is the clause to be tested (as a RestrictInfo node).
2699 : : * 'indexcol' is a column number of 'index' (counting from 0).
2700 : : * 'index' is the index of interest.
2701 : : *
2702 : : * Returns an IndexClause if the clause can be used with this index key,
2703 : : * or NULL if not.
2704 : : *
2705 : : * NOTE: This routine always returns NULL if the clause is an AND clause.
2706 : : * Higher-level routines deal with OR and AND clauses. OR clause can be
2707 : : * matched as a whole by match_orclause_to_indexcol() though.
2708 : : */
2709 : : static IndexClause *
2399 2710 : 836148 : match_clause_to_indexcol(PlannerInfo *root,
2711 : : RestrictInfo *rinfo,
2712 : : int indexcol,
2713 : : IndexOptInfo *index)
2714 : : {
2715 : : IndexClause *iclause;
7916 2716 : 836148 : Expr *clause = rinfo->clause;
2717 : : Oid opfamily;
2718 : :
2704 teodor@sigaev.ru 2719 [ - + ]: 836148 : Assert(indexcol < index->nkeycolumns);
2720 : :
2721 : : /*
2722 : : * Historically this code has coped with NULL clauses. That's probably
2723 : : * not possible anymore, but we might as well continue to cope.
2724 : : */
2399 tgl@sss.pgh.pa.us 2725 [ - + ]: 836148 : if (clause == NULL)
2399 tgl@sss.pgh.pa.us 2726 :UBC 0 : return NULL;
2727 : :
2728 : : /* First check for boolean-index cases. */
2399 tgl@sss.pgh.pa.us 2729 :CBC 836148 : opfamily = index->opfamily[indexcol];
6832 2730 [ + + ]: 836148 : if (IsBooleanOpfamily(opfamily))
2731 : : {
1689 2732 : 228 : iclause = match_boolean_index_clause(root, rinfo, indexcol, index);
2399 2733 [ + + ]: 228 : if (iclause)
2734 : 149 : return iclause;
2735 : : }
2736 : :
2737 : : /*
2738 : : * Clause must be an opclause, funcclause, ScalarArrayOpExpr,
2739 : : * RowCompareExpr, or OR-clause that could be converted to SAOP. Or, if
2740 : : * the index supports it, we can handle IS NULL/NOT NULL clauses.
2741 : : */
2742 [ + + ]: 835999 : if (IsA(clause, OpExpr))
2743 : : {
2744 : 701069 : return match_opclause_to_indexcol(root, rinfo, indexcol, index);
2745 : : }
2746 [ + + ]: 134930 : else if (IsA(clause, FuncExpr))
2747 : : {
2748 : 14695 : return match_funcclause_to_indexcol(root, rinfo, indexcol, index);
2749 : : }
2750 [ + + ]: 120235 : else if (IsA(clause, ScalarArrayOpExpr))
2751 : : {
1689 2752 : 37954 : return match_saopclause_to_indexcol(root, rinfo, indexcol, index);
2753 : : }
2399 2754 [ + + ]: 82281 : else if (IsA(clause, RowCompareExpr))
2755 : : {
1689 2756 : 252 : return match_rowcompare_to_indexcol(root, rinfo, indexcol, index);
2757 : : }
286 akorotkov@postgresql 2758 [ + + ]: 82029 : else if (restriction_is_or_clause(rinfo))
2759 : : {
2760 : 21695 : return match_orclause_to_indexcol(root, rinfo, indexcol, index);
2761 : : }
6728 tgl@sss.pgh.pa.us 2762 [ + - + + ]: 60334 : else if (index->amsearchnulls && IsA(clause, NullTest))
2763 : : {
6505 bruce@momjian.us 2764 : 7812 : NullTest *nt = (NullTest *) clause;
2765 : :
5727 tgl@sss.pgh.pa.us 2766 [ + - + + ]: 15624 : if (!nt->argisrow &&
2767 : 7812 : match_index_to_operand((Node *) nt->arg, indexcol, index))
2768 : : {
2399 2769 : 724 : iclause = makeNode(IndexClause);
2770 : 724 : iclause->rinfo = rinfo;
2396 2771 : 724 : iclause->indexquals = list_make1(rinfo);
2399 2772 : 724 : iclause->lossy = false;
2773 : 724 : iclause->indexcol = indexcol;
2774 : 724 : iclause->indexcols = NIL;
2775 : 724 : return iclause;
2776 : : }
2777 : : }
2778 : :
2779 : 59610 : return NULL;
2780 : : }
2781 : :
2782 : : /*
2783 : : * IsBooleanOpfamily
2784 : : * Detect whether an opfamily supports boolean equality as an operator.
2785 : : *
2786 : : * If the opfamily OID is in the range of built-in objects, we can rely
2787 : : * on hard-wired knowledge of which built-in opfamilies support this.
2788 : : * For extension opfamilies, there's no choice but to do a catcache lookup.
2789 : : */
2790 : : static bool
1100 2791 : 1145388 : IsBooleanOpfamily(Oid opfamily)
2792 : : {
2793 [ + + ]: 1145388 : if (opfamily < FirstNormalObjectId)
2794 [ + + - + ]: 1143569 : return IsBuiltinBooleanOpfamily(opfamily);
2795 : : else
2796 : 1819 : return op_in_opfamily(BooleanEqualOperator, opfamily);
2797 : : }
2798 : :
2799 : : /*
2800 : : * match_boolean_index_clause
2801 : : * Recognize restriction clauses that can be matched to a boolean index.
2802 : : *
2803 : : * The idea here is that, for an index on a boolean column that supports the
2804 : : * BooleanEqualOperator, we can transform a plain reference to the indexkey
2805 : : * into "indexkey = true", or "NOT indexkey" into "indexkey = false", etc,
2806 : : * so as to make the expression indexable using the index's "=" operator.
2807 : : * Since Postgres 8.1, we must do this because constant simplification does
2808 : : * the reverse transformation; without this code there'd be no way to use
2809 : : * such an index at all.
2810 : : *
2811 : : * This should be called only when IsBooleanOpfamily() recognizes the
2812 : : * index's operator family. We check to see if the clause matches the
2813 : : * index's key, and if so, build a suitable IndexClause.
2814 : : */
2815 : : static IndexClause *
1689 2816 : 866 : match_boolean_index_clause(PlannerInfo *root,
2817 : : RestrictInfo *rinfo,
2818 : : int indexcol,
2819 : : IndexOptInfo *index)
2820 : : {
2399 2821 : 866 : Node *clause = (Node *) rinfo->clause;
2822 : 866 : Expr *op = NULL;
2823 : :
2824 : : /* Direct match? */
2825 [ + + ]: 866 : if (match_index_to_operand(clause, indexcol, index))
2826 : : {
2827 : : /* convert to indexkey = TRUE */
2828 : 147 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2829 : : (Expr *) clause,
2830 : 147 : (Expr *) makeBoolConst(true, false),
2831 : : InvalidOid, InvalidOid);
2832 : : }
2833 : : /* NOT clause? */
2834 [ + + ]: 719 : else if (is_notclause(clause))
2835 : : {
2836 : 604 : Node *arg = (Node *) get_notclausearg((Expr *) clause);
2837 : :
2838 [ + - ]: 604 : if (match_index_to_operand(arg, indexcol, index))
2839 : : {
2840 : : /* convert to indexkey = FALSE */
2841 : 604 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2842 : : (Expr *) arg,
2843 : 604 : (Expr *) makeBoolConst(false, false),
2844 : : InvalidOid, InvalidOid);
2845 : : }
2846 : : }
2847 : :
2848 : : /*
2849 : : * Since we only consider clauses at top level of WHERE, we can convert
2850 : : * indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
2851 : : * different meaning for NULL isn't important.
2852 : : */
2853 [ + - + + ]: 115 : else if (clause && IsA(clause, BooleanTest))
2854 : : {
2855 : 18 : BooleanTest *btest = (BooleanTest *) clause;
2856 : 18 : Node *arg = (Node *) btest->arg;
2857 : :
2858 [ + + + - ]: 27 : if (btest->booltesttype == IS_TRUE &&
2859 : 9 : match_index_to_operand(arg, indexcol, index))
2860 : : {
2861 : : /* convert to indexkey = TRUE */
2862 : 9 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2863 : : (Expr *) arg,
2864 : 9 : (Expr *) makeBoolConst(true, false),
2865 : : InvalidOid, InvalidOid);
2866 : : }
2867 [ + - + - ]: 18 : else if (btest->booltesttype == IS_FALSE &&
2868 : 9 : match_index_to_operand(arg, indexcol, index))
2869 : : {
2870 : : /* convert to indexkey = FALSE */
2871 : 9 : op = make_opclause(BooleanEqualOperator, BOOLOID, false,
2872 : : (Expr *) arg,
2873 : 9 : (Expr *) makeBoolConst(false, false),
2874 : : InvalidOid, InvalidOid);
2875 : : }
2876 : : }
2877 : :
2878 : : /*
2879 : : * If we successfully made an operator clause from the given qual, we must
2880 : : * wrap it in an IndexClause. It's not lossy.
2881 : : */
2882 [ + + ]: 866 : if (op)
2883 : : {
2884 : 769 : IndexClause *iclause = makeNode(IndexClause);
2885 : :
2886 : 769 : iclause->rinfo = rinfo;
1689 2887 : 769 : iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
2399 2888 : 769 : iclause->lossy = false;
2889 : 769 : iclause->indexcol = indexcol;
2890 : 769 : iclause->indexcols = NIL;
2891 : 769 : return iclause;
2892 : : }
2893 : :
2894 : 97 : return NULL;
2895 : : }
2896 : :
2897 : : /*
2898 : : * match_opclause_to_indexcol()
2899 : : * Handles the OpExpr case for match_clause_to_indexcol(),
2900 : : * which see for comments.
2901 : : */
2902 : : static IndexClause *
2903 : 701069 : match_opclause_to_indexcol(PlannerInfo *root,
2904 : : RestrictInfo *rinfo,
2905 : : int indexcol,
2906 : : IndexOptInfo *index)
2907 : : {
2908 : : IndexClause *iclause;
2909 : 701069 : OpExpr *clause = (OpExpr *) rinfo->clause;
2910 : : Node *leftop,
2911 : : *rightop;
2912 : : Oid expr_op;
2913 : : Oid expr_coll;
2914 : : Index index_relid;
2915 : : Oid opfamily;
2916 : : Oid idxcollation;
2917 : :
2918 : : /*
2919 : : * Only binary operators need apply. (In theory, a planner support
2920 : : * function could do something with a unary operator, but it seems
2921 : : * unlikely to be worth the cycles to check.)
2922 : : */
2923 [ - + ]: 701069 : if (list_length(clause->args) != 2)
2399 tgl@sss.pgh.pa.us 2924 :UBC 0 : return NULL;
2925 : :
2399 tgl@sss.pgh.pa.us 2926 :CBC 701069 : leftop = (Node *) linitial(clause->args);
2927 : 701069 : rightop = (Node *) lsecond(clause->args);
2928 : 701069 : expr_op = clause->opno;
2929 : 701069 : expr_coll = clause->inputcollid;
2930 : :
2931 : 701069 : index_relid = index->rel->relid;
2932 : 701069 : opfamily = index->opfamily[indexcol];
2933 : 701069 : idxcollation = index->indexcollations[indexcol];
2934 : :
2935 : : /*
2936 : : * Check for clauses of the form: (indexkey operator constant) or
2937 : : * (constant operator indexkey). See match_clause_to_indexcol's notes
2938 : : * about const-ness.
2939 : : *
2940 : : * Note that we don't ask the support function about clauses that don't
2941 : : * have one of these forms. Again, in principle it might be possible to
2942 : : * do something, but it seems unlikely to be worth the cycles to check.
2943 : : */
7468 2944 [ + + ]: 701069 : if (match_index_to_operand(leftop, indexcol, index) &&
2399 2945 [ + + ]: 166586 : !bms_is_member(index_relid, rinfo->right_relids) &&
7442 2946 [ + - ]: 166499 : !contain_volatile_functions(rightop))
2947 : : {
5091 2948 [ + + + + : 329696 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
+ + ]
2399 2949 : 163197 : op_in_opfamily(expr_op, opfamily))
2950 : : {
2951 : 159642 : iclause = makeNode(IndexClause);
2952 : 159642 : iclause->rinfo = rinfo;
2396 2953 : 159642 : iclause->indexquals = list_make1(rinfo);
2399 2954 : 159642 : iclause->lossy = false;
2955 : 159642 : iclause->indexcol = indexcol;
2956 : 159642 : iclause->indexcols = NIL;
2957 : 159642 : return iclause;
2958 : : }
2959 : :
2960 : : /*
2961 : : * If we didn't find a member of the index's opfamily, try the support
2962 : : * function for the operator's underlying function.
2963 : : */
2964 : 6857 : set_opfuncid(clause); /* make sure we have opfuncid */
2965 : 6857 : return get_index_clause_from_support(root,
2966 : : rinfo,
2967 : : clause->opfuncid,
2968 : : 0, /* indexarg on left */
2969 : : indexcol,
2970 : : index);
2971 : : }
2972 : :
2973 [ + + ]: 534570 : if (match_index_to_operand(rightop, indexcol, index) &&
2974 [ + + ]: 29634 : !bms_is_member(index_relid, rinfo->left_relids) &&
7442 2975 [ + - ]: 29571 : !contain_volatile_functions(leftop))
2976 : : {
2399 2977 [ + + + + ]: 29571 : if (IndexCollMatchesExprColl(idxcollation, expr_coll))
2978 : : {
2979 : 29565 : Oid comm_op = get_commutator(expr_op);
2980 : :
2981 [ + - + + ]: 59130 : if (OidIsValid(comm_op) &&
2982 : 29565 : op_in_opfamily(comm_op, opfamily))
2983 : : {
2984 : : RestrictInfo *commrinfo;
2985 : :
2986 : : /* Build a commuted OpExpr and RestrictInfo */
2987 : 29328 : commrinfo = commute_restrictinfo(rinfo, comm_op);
2988 : :
2989 : : /* Make an IndexClause showing that as a derived qual */
2990 : 29328 : iclause = makeNode(IndexClause);
2991 : 29328 : iclause->rinfo = rinfo;
2992 : 29328 : iclause->indexquals = list_make1(commrinfo);
2993 : 29328 : iclause->lossy = false;
2994 : 29328 : iclause->indexcol = indexcol;
2995 : 29328 : iclause->indexcols = NIL;
2996 : 29328 : return iclause;
2997 : : }
2998 : : }
2999 : :
3000 : : /*
3001 : : * If we didn't find a member of the index's opfamily, try the support
3002 : : * function for the operator's underlying function.
3003 : : */
3004 : 243 : set_opfuncid(clause); /* make sure we have opfuncid */
3005 : 243 : return get_index_clause_from_support(root,
3006 : : rinfo,
3007 : : clause->opfuncid,
3008 : : 1, /* indexarg on right */
3009 : : indexcol,
3010 : : index);
3011 : : }
3012 : :
3013 : 504999 : return NULL;
3014 : : }
3015 : :
3016 : : /*
3017 : : * match_funcclause_to_indexcol()
3018 : : * Handles the FuncExpr case for match_clause_to_indexcol(),
3019 : : * which see for comments.
3020 : : */
3021 : : static IndexClause *
3022 : 14695 : match_funcclause_to_indexcol(PlannerInfo *root,
3023 : : RestrictInfo *rinfo,
3024 : : int indexcol,
3025 : : IndexOptInfo *index)
3026 : : {
3027 : 14695 : FuncExpr *clause = (FuncExpr *) rinfo->clause;
3028 : : int indexarg;
3029 : : ListCell *lc;
3030 : :
3031 : : /*
3032 : : * We have no built-in intelligence about function clauses, but if there's
3033 : : * a planner support function, it might be able to do something. But, to
3034 : : * cut down on wasted planning cycles, only call the support function if
3035 : : * at least one argument matches the target index column.
3036 : : *
3037 : : * Note that we don't insist on the other arguments being pseudoconstants;
3038 : : * the support function has to check that. This is to allow cases where
3039 : : * only some of the other arguments need to be included in the indexqual.
3040 : : */
3041 : 14695 : indexarg = 0;
3042 [ + - + + : 31673 : foreach(lc, clause->args)
+ + ]
3043 : : {
3044 : 19847 : Node *op = (Node *) lfirst(lc);
3045 : :
3046 [ + + ]: 19847 : if (match_index_to_operand(op, indexcol, index))
3047 : : {
3048 : 2869 : return get_index_clause_from_support(root,
3049 : : rinfo,
3050 : : clause->funcid,
3051 : : indexarg,
3052 : : indexcol,
3053 : : index);
3054 : : }
3055 : :
3056 : 16978 : indexarg++;
3057 : : }
3058 : :
3059 : 11826 : return NULL;
3060 : : }
3061 : :
3062 : : /*
3063 : : * get_index_clause_from_support()
3064 : : * If the function has a planner support function, try to construct
3065 : : * an IndexClause using indexquals created by the support function.
3066 : : */
3067 : : static IndexClause *
3068 : 9969 : get_index_clause_from_support(PlannerInfo *root,
3069 : : RestrictInfo *rinfo,
3070 : : Oid funcid,
3071 : : int indexarg,
3072 : : int indexcol,
3073 : : IndexOptInfo *index)
3074 : : {
3075 : 9969 : Oid prosupport = get_func_support(funcid);
3076 : : SupportRequestIndexCondition req;
3077 : : List *sresult;
3078 : :
3079 [ + + ]: 9969 : if (!OidIsValid(prosupport))
3080 : 5933 : return NULL;
3081 : :
3082 : 4036 : req.type = T_SupportRequestIndexCondition;
3083 : 4036 : req.root = root;
3084 : 4036 : req.funcid = funcid;
3085 : 4036 : req.node = (Node *) rinfo->clause;
3086 : 4036 : req.indexarg = indexarg;
3087 : 4036 : req.index = index;
3088 : 4036 : req.indexcol = indexcol;
3089 : 4036 : req.opfamily = index->opfamily[indexcol];
3090 : 4036 : req.indexcollation = index->indexcollations[indexcol];
3091 : :
3092 : 4036 : req.lossy = true; /* default assumption */
3093 : :
3094 : : sresult = (List *)
3095 : 4036 : DatumGetPointer(OidFunctionCall1(prosupport,
3096 : : PointerGetDatum(&req)));
3097 : :
3098 [ + + ]: 4036 : if (sresult != NIL)
3099 : : {
3100 : 701 : IndexClause *iclause = makeNode(IndexClause);
3101 : 701 : List *indexquals = NIL;
3102 : : ListCell *lc;
3103 : :
3104 : : /*
3105 : : * The support function API says it should just give back bare
3106 : : * clauses, so here we must wrap each one in a RestrictInfo.
3107 : : */
3108 [ + - + + : 2064 : foreach(lc, sresult)
+ + ]
3109 : : {
3110 : 1363 : Expr *clause = (Expr *) lfirst(lc);
3111 : :
1689 3112 : 1363 : indexquals = lappend(indexquals,
3113 : 1363 : make_simple_restrictinfo(root, clause));
3114 : : }
3115 : :
2399 3116 : 701 : iclause->rinfo = rinfo;
3117 : 701 : iclause->indexquals = indexquals;
3118 : 701 : iclause->lossy = req.lossy;
3119 : 701 : iclause->indexcol = indexcol;
3120 : 701 : iclause->indexcols = NIL;
3121 : :
3122 : 701 : return iclause;
3123 : : }
3124 : :
3125 : 3335 : return NULL;
3126 : : }
3127 : :
3128 : : /*
3129 : : * match_saopclause_to_indexcol()
3130 : : * Handles the ScalarArrayOpExpr case for match_clause_to_indexcol(),
3131 : : * which see for comments.
3132 : : */
3133 : : static IndexClause *
1689 3134 : 37954 : match_saopclause_to_indexcol(PlannerInfo *root,
3135 : : RestrictInfo *rinfo,
3136 : : int indexcol,
3137 : : IndexOptInfo *index)
3138 : : {
2399 3139 : 37954 : ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
3140 : : Node *leftop,
3141 : : *rightop;
3142 : : Relids right_relids;
3143 : : Oid expr_op;
3144 : : Oid expr_coll;
3145 : : Index index_relid;
3146 : : Oid opfamily;
3147 : : Oid idxcollation;
3148 : :
3149 : : /* We only accept ANY clauses, not ALL */
3150 [ + + ]: 37954 : if (!saop->useOr)
3151 : 4549 : return NULL;
3152 : 33405 : leftop = (Node *) linitial(saop->args);
3153 : 33405 : rightop = (Node *) lsecond(saop->args);
1689 3154 : 33405 : right_relids = pull_varnos(root, rightop);
2399 3155 : 33405 : expr_op = saop->opno;
3156 : 33405 : expr_coll = saop->inputcollid;
3157 : :
3158 : 33405 : index_relid = index->rel->relid;
3159 : 33405 : opfamily = index->opfamily[indexcol];
3160 : 33405 : idxcollation = index->indexcollations[indexcol];
3161 : :
3162 : : /*
3163 : : * We must have indexkey on the left and a pseudo-constant array argument.
3164 : : */
3165 [ + + ]: 33405 : if (match_index_to_operand(leftop, indexcol, index) &&
3166 [ + - ]: 3356 : !bms_is_member(index_relid, right_relids) &&
3167 [ + - ]: 3356 : !contain_volatile_functions(rightop))
3168 : : {
3169 [ + + + + : 6709 : if (IndexCollMatchesExprColl(idxcollation, expr_coll) &&
+ + ]
3170 : 3353 : op_in_opfamily(expr_op, opfamily))
3171 : : {
3172 : 3347 : IndexClause *iclause = makeNode(IndexClause);
3173 : :
3174 : 3347 : iclause->rinfo = rinfo;
2396 3175 : 3347 : iclause->indexquals = list_make1(rinfo);
2399 3176 : 3347 : iclause->lossy = false;
3177 : 3347 : iclause->indexcol = indexcol;
3178 : 3347 : iclause->indexcols = NIL;
3179 : 3347 : return iclause;
3180 : : }
3181 : :
3182 : : /*
3183 : : * We do not currently ask support functions about ScalarArrayOpExprs,
3184 : : * though in principle we could.
3185 : : */
3186 : : }
3187 : :
3188 : 30058 : return NULL;
3189 : : }
3190 : :
3191 : : /*
3192 : : * match_rowcompare_to_indexcol()
3193 : : * Handles the RowCompareExpr case for match_clause_to_indexcol(),
3194 : : * which see for comments.
3195 : : *
3196 : : * In this routine we check whether the first column of the row comparison
3197 : : * matches the target index column. This is sufficient to guarantee that some
3198 : : * index condition can be constructed from the RowCompareExpr --- the rest
3199 : : * is handled by expand_indexqual_rowcompare().
3200 : : */
3201 : : static IndexClause *
1689 3202 : 252 : match_rowcompare_to_indexcol(PlannerInfo *root,
3203 : : RestrictInfo *rinfo,
3204 : : int indexcol,
3205 : : IndexOptInfo *index)
3206 : : {
2399 3207 : 252 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3208 : : Index index_relid;
3209 : : Oid opfamily;
3210 : : Oid idxcollation;
3211 : : Node *leftop,
3212 : : *rightop;
3213 : : bool var_on_left;
3214 : : Oid expr_op;
3215 : : Oid expr_coll;
3216 : :
3217 : : /* Forget it if we're not dealing with a btree index */
7164 3218 [ - + ]: 252 : if (index->relam != BTREE_AM_OID)
2399 tgl@sss.pgh.pa.us 3219 :UBC 0 : return NULL;
3220 : :
2399 tgl@sss.pgh.pa.us 3221 :CBC 252 : index_relid = index->rel->relid;
3222 : 252 : opfamily = index->opfamily[indexcol];
3223 : 252 : idxcollation = index->indexcollations[indexcol];
3224 : :
3225 : : /*
3226 : : * We could do the matching on the basis of insisting that the opfamily
3227 : : * shown in the RowCompareExpr be the same as the index column's opfamily,
3228 : : * but that could fail in the presence of reverse-sort opfamilies: it'd be
3229 : : * a matter of chance whether RowCompareExpr had picked the forward or
3230 : : * reverse-sort family. So look only at the operator, and match if it is
3231 : : * a member of the index's opfamily (after commutation, if the indexkey is
3232 : : * on the right). We'll worry later about whether any additional
3233 : : * operators are matchable to the index.
3234 : : */
7164 3235 : 252 : leftop = (Node *) linitial(clause->largs);
3236 : 252 : rightop = (Node *) linitial(clause->rargs);
3237 : 252 : expr_op = linitial_oid(clause->opnos);
5265 3238 : 252 : expr_coll = linitial_oid(clause->inputcollids);
3239 : :
3240 : : /* Collations must match, if relevant */
5091 3241 [ + + - + ]: 252 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
2399 tgl@sss.pgh.pa.us 3242 :UBC 0 : return NULL;
3243 : :
3244 : : /*
3245 : : * These syntactic tests are the same as in match_opclause_to_indexcol()
3246 : : */
7164 tgl@sss.pgh.pa.us 3247 [ + + ]:CBC 252 : if (match_index_to_operand(leftop, indexcol, index) &&
1689 3248 [ + - ]: 81 : !bms_is_member(index_relid, pull_varnos(root, rightop)) &&
7164 3249 [ + - ]: 81 : !contain_volatile_functions(rightop))
3250 : : {
3251 : : /* OK, indexkey is on left */
2399 3252 : 81 : var_on_left = true;
3253 : : }
7164 3254 [ + + ]: 171 : else if (match_index_to_operand(rightop, indexcol, index) &&
1689 3255 [ + - ]: 12 : !bms_is_member(index_relid, pull_varnos(root, leftop)) &&
7164 3256 [ + - ]: 12 : !contain_volatile_functions(leftop))
3257 : : {
3258 : : /* indexkey is on right, so commute the operator */
3259 : 12 : expr_op = get_commutator(expr_op);
3260 [ - + ]: 12 : if (expr_op == InvalidOid)
2399 tgl@sss.pgh.pa.us 3261 :UBC 0 : return NULL;
2399 tgl@sss.pgh.pa.us 3262 :CBC 12 : var_on_left = false;
3263 : : }
3264 : : else
3265 : 159 : return NULL;
3266 : :
3267 : : /* We're good if the operator is the right type of opfamily member */
6832 3268 [ + - ]: 93 : switch (get_op_opfamily_strategy(expr_op, opfamily))
3269 : : {
7164 3270 : 93 : case BTLessStrategyNumber:
3271 : : case BTLessEqualStrategyNumber:
3272 : : case BTGreaterEqualStrategyNumber:
3273 : : case BTGreaterStrategyNumber:
1689 3274 : 93 : return expand_indexqual_rowcompare(root,
3275 : : rinfo,
3276 : : indexcol,
3277 : : index,
3278 : : expr_op,
3279 : : var_on_left);
3280 : : }
3281 : :
2399 tgl@sss.pgh.pa.us 3282 :UBC 0 : return NULL;
3283 : : }
3284 : :
3285 : : /*
3286 : : * match_orclause_to_indexcol()
3287 : : * Handles the OR-expr case for match_clause_to_indexcol() in the case
3288 : : * when it could be transformed to ScalarArrayOpExpr.
3289 : : *
3290 : : * In this routine, we attempt to transform a list of OR-clause args into a
3291 : : * single SAOP expression matching the target index column. On success,
3292 : : * return an IndexClause, containing the transformed expression or NULL,
3293 : : * if failed.
3294 : : */
3295 : : static IndexClause *
286 akorotkov@postgresql 3296 :CBC 21695 : match_orclause_to_indexcol(PlannerInfo *root,
3297 : : RestrictInfo *rinfo,
3298 : : int indexcol,
3299 : : IndexOptInfo *index)
3300 : : {
3301 : : ListCell *lc;
3302 : 21695 : BoolExpr *orclause = (BoolExpr *) rinfo->orclause;
3303 : 21695 : Node *indexExpr = NULL;
3304 : 21695 : List *consts = NIL;
3305 : 21695 : ScalarArrayOpExpr *saopexpr = NULL;
3306 : 21695 : Oid matchOpno = InvalidOid;
3307 : : IndexClause *iclause;
3308 : 21695 : Oid consttype = InvalidOid;
3309 : 21695 : Oid arraytype = InvalidOid;
3310 : 21695 : Oid inputcollid = InvalidOid;
3311 : 21695 : bool firstTime = true;
214 3312 : 21695 : bool haveNonConst = false;
3313 : 21695 : Index indexRelid = index->rel->relid;
3314 : :
286 3315 [ - + ]: 21695 : Assert(IsA(orclause, BoolExpr));
3316 [ - + ]: 21695 : Assert(orclause->boolop == OR_EXPR);
3317 : :
3318 : : /* Ignore index if it doesn't support SAOP clauses */
281 3319 [ + + ]: 21695 : if (!index->amsearcharray)
3320 : 53 : return NULL;
3321 : :
3322 : : /*
3323 : : * Try to convert a list of OR-clauses to a single SAOP expression. Each
3324 : : * OR entry must be in the form: (indexkey operator constant) or (constant
3325 : : * operator indexkey). Operators of all the entries must match. To be
3326 : : * effective, give up on the first non-matching entry. Exit is
3327 : : * implemented as a break from the loop, which is catched afterwards.
3328 : : */
286 3329 [ + - + + : 23908 : foreach(lc, orclause->args)
+ + ]
3330 : : {
3331 : : RestrictInfo *subRinfo;
3332 : : OpExpr *subClause;
3333 : : Oid opno;
3334 : : Node *leftop,
3335 : : *rightop;
3336 : : Node *constExpr;
3337 : :
3338 [ + + ]: 23383 : if (!IsA(lfirst(lc), RestrictInfo))
3339 : 2558 : break;
3340 : :
3341 : 20825 : subRinfo = (RestrictInfo *) lfirst(lc);
3342 : :
3343 : : /* Only operator clauses can match */
3344 [ + + ]: 20825 : if (!IsA(subRinfo->clause, OpExpr))
3345 : 6140 : break;
3346 : :
3347 : 14685 : subClause = (OpExpr *) subRinfo->clause;
3348 : 14685 : opno = subClause->opno;
3349 : :
3350 : : /* Only binary operators can match */
3351 [ - + ]: 14685 : if (list_length(subClause->args) != 2)
286 akorotkov@postgresql 3352 :UBC 0 : break;
3353 : :
3354 : : /*
3355 : : * The parameters below must match between sub-rinfo and its parent as
3356 : : * make_restrictinfo() fills them with the same values, and further
3357 : : * modifications are also the same for the whole subtree. However,
3358 : : * still make a sanity check.
3359 : : */
286 akorotkov@postgresql 3360 [ - + ]:CBC 14685 : Assert(subRinfo->is_pushed_down == rinfo->is_pushed_down);
3361 [ - + ]: 14685 : Assert(subRinfo->is_clone == rinfo->is_clone);
3362 [ - + ]: 14685 : Assert(subRinfo->security_level == rinfo->security_level);
3363 [ - + ]: 14685 : Assert(bms_equal(subRinfo->incompatible_relids, rinfo->incompatible_relids));
3364 [ - + ]: 14685 : Assert(bms_equal(subRinfo->outer_relids, rinfo->outer_relids));
3365 : :
3366 : : /*
3367 : : * Also, check that required_relids in sub-rinfo is subset of parent's
3368 : : * required_relids.
3369 : : */
3370 [ - + ]: 14685 : Assert(bms_is_subset(subRinfo->required_relids, rinfo->required_relids));
3371 : :
3372 : : /* Only the operator returning a boolean suit the transformation. */
3373 [ - + ]: 14685 : if (get_op_rettype(opno) != BOOLOID)
286 akorotkov@postgresql 3374 :UBC 0 : break;
3375 : :
3376 : : /*
3377 : : * Check for clauses of the form: (indexkey operator constant) or
3378 : : * (constant operator indexkey). See match_clause_to_indexcol's notes
3379 : : * about const-ness.
3380 : : */
286 akorotkov@postgresql 3381 :CBC 14685 : leftop = (Node *) linitial(subClause->args);
3382 : 14685 : rightop = (Node *) lsecond(subClause->args);
214 3383 [ + + ]: 14685 : if (match_index_to_operand(leftop, indexcol, index) &&
3384 [ + + ]: 3175 : !bms_is_member(indexRelid, subRinfo->right_relids) &&
3385 [ + - ]: 3160 : !contain_volatile_functions(rightop))
3386 : : {
286 3387 : 3160 : indexExpr = leftop;
3388 : 3160 : constExpr = rightop;
3389 : : }
214 3390 [ + + ]: 11525 : else if (match_index_to_operand(rightop, indexcol, index) &&
3391 [ + + ]: 95 : !bms_is_member(indexRelid, subRinfo->left_relids) &&
3392 [ + - ]: 92 : !contain_volatile_functions(leftop))
3393 : : {
286 3394 : 92 : opno = get_commutator(opno);
3395 [ - + ]: 92 : if (!OidIsValid(opno))
3396 : : {
3397 : : /* commutator doesn't exist, we can't reverse the order */
286 akorotkov@postgresql 3398 :UBC 0 : break;
3399 : : }
286 akorotkov@postgresql 3400 :CBC 92 : indexExpr = rightop;
3401 : 92 : constExpr = leftop;
3402 : : }
3403 : : else
3404 : : {
3405 : : break;
3406 : : }
3407 : :
3408 : : /*
3409 : : * Ignore any RelabelType node above the operands. This is needed to
3410 : : * be able to apply indexscanning in binary-compatible-operator cases.
3411 : : * Note: we can assume there is at most one RelabelType node;
3412 : : * eval_const_expressions() will have simplified if more than one.
3413 : : */
3414 [ - + ]: 3252 : if (IsA(constExpr, RelabelType))
286 akorotkov@postgresql 3415 :UBC 0 : constExpr = (Node *) ((RelabelType *) constExpr)->arg;
286 akorotkov@postgresql 3416 [ + + ]:CBC 3252 : if (IsA(indexExpr, RelabelType))
3417 : 6 : indexExpr = (Node *) ((RelabelType *) indexExpr)->arg;
3418 : :
3419 : : /* Forbid transformation for composite types, records. */
3420 [ + - + - ]: 6504 : if (type_is_rowtype(exprType(constExpr)) ||
3421 : 3252 : type_is_rowtype(exprType(indexExpr)))
3422 : : break;
3423 : :
3424 : : /*
3425 : : * Save information about the operator, type, and collation for the
3426 : : * first matching qual. Then, check that subsequent quals match the
3427 : : * first.
3428 : : */
3429 [ + + ]: 3252 : if (firstTime)
3430 : : {
3431 : 2373 : matchOpno = opno;
3432 : 2373 : consttype = exprType(constExpr);
3433 : 2373 : arraytype = get_array_type(consttype);
3434 : 2373 : inputcollid = subClause->inputcollid;
3435 : :
3436 : : /*
3437 : : * Check that the operator is presented in the opfamily and that
3438 : : * the expression collation matches the index collation. Also,
3439 : : * there must be an array type to construct an array later.
3440 : : */
3441 [ + + + + ]: 2373 : if (!IndexCollMatchesExprColl(index->indexcollations[indexcol], inputcollid) ||
3442 [ + + + - ]: 2310 : !op_in_opfamily(matchOpno, index->opfamily[indexcol]) ||
3443 : : !OidIsValid(arraytype))
3444 : : break;
3445 : 1459 : firstTime = false;
3446 : : }
3447 : : else
3448 : : {
3449 [ + + ]: 879 : if (opno != matchOpno ||
3450 [ + - + - ]: 1614 : inputcollid != subClause->inputcollid ||
3451 : 807 : consttype != exprType(constExpr))
3452 : : break;
3453 : : }
3454 : :
3455 : : /*
3456 : : * Check if our list of constants in match_clause_to_indexcol's
3457 : : * understanding of const-ness have something other than Const.
3458 : : */
214 3459 [ + + ]: 2266 : if (!IsA(constExpr, Const))
3460 : 182 : haveNonConst = true;
286 3461 : 2266 : consts = lappend(consts, constExpr);
3462 : : }
3463 : :
3464 : : /*
3465 : : * Catch the break from the loop above. Normally, a foreach() loop ends
3466 : : * up with a NULL list cell. A non-NULL list cell indicates a break from
3467 : : * the foreach() loop. Free the consts list and return NULL then.
3468 : : */
3469 [ + + ]: 21642 : if (lc != NULL)
3470 : : {
3471 : 21117 : list_free(consts);
3472 : 21117 : return NULL;
3473 : : }
3474 : :
155 3475 : 525 : saopexpr = make_SAOP_expr(matchOpno, indexExpr, consttype, inputcollid,
3476 : : inputcollid, consts, haveNonConst);
3477 : :
3478 : : /*
3479 : : * Finally, build an IndexClause based on the SAOP node. Use
3480 : : * make_simple_restrictinfo() to get RestrictInfo with clean selectivity
3481 : : * estimations, because they may differ from the estimation made for an OR
3482 : : * clause. Although it is not a lossy expression, keep the original rinfo
3483 : : * in iclause->rinfo as prescribed.
3484 : : */
286 3485 : 525 : iclause = makeNode(IndexClause);
3486 : 525 : iclause->rinfo = rinfo;
3487 : 525 : iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3488 : : &saopexpr->xpr));
3489 : 525 : iclause->lossy = false;
3490 : 525 : iclause->indexcol = indexcol;
3491 : 525 : iclause->indexcols = NIL;
3492 : 525 : return iclause;
3493 : : }
3494 : :
3495 : : /*
3496 : : * expand_indexqual_rowcompare --- expand a single indexqual condition
3497 : : * that is a RowCompareExpr
3498 : : *
3499 : : * It's already known that the first column of the row comparison matches
3500 : : * the specified column of the index. We can use additional columns of the
3501 : : * row comparison as index qualifications, so long as they match the index
3502 : : * in the "same direction", ie, the indexkeys are all on the same side of the
3503 : : * clause and the operators are all the same-type members of the opfamilies.
3504 : : *
3505 : : * If all the columns of the RowCompareExpr match in this way, we just use it
3506 : : * as-is, except for possibly commuting it to put the indexkeys on the left.
3507 : : *
3508 : : * Otherwise, we build a shortened RowCompareExpr (if more than one
3509 : : * column matches) or a simple OpExpr (if the first-column match is all
3510 : : * there is). In these cases the modified clause is always "<=" or ">="
3511 : : * even when the original was "<" or ">" --- this is necessary to match all
3512 : : * the rows that could match the original. (We are building a lossy version
3513 : : * of the row comparison when we do this, so we set lossy = true.)
3514 : : *
3515 : : * Note: this is really just the last half of match_rowcompare_to_indexcol,
3516 : : * but we split it out for comprehensibility.
3517 : : */
3518 : : static IndexClause *
1689 tgl@sss.pgh.pa.us 3519 : 93 : expand_indexqual_rowcompare(PlannerInfo *root,
3520 : : RestrictInfo *rinfo,
3521 : : int indexcol,
3522 : : IndexOptInfo *index,
3523 : : Oid expr_op,
3524 : : bool var_on_left)
3525 : : {
2399 3526 : 93 : IndexClause *iclause = makeNode(IndexClause);
3527 : 93 : RowCompareExpr *clause = (RowCompareExpr *) rinfo->clause;
3528 : : int op_strategy;
3529 : : Oid op_lefttype;
3530 : : Oid op_righttype;
3531 : : int matching_cols;
3532 : : List *expr_ops;
3533 : : List *opfamilies;
3534 : : List *lefttypes;
3535 : : List *righttypes;
3536 : : List *new_ops;
3537 : : List *var_args;
3538 : : List *non_var_args;
3539 : :
3540 : 93 : iclause->rinfo = rinfo;
3541 : 93 : iclause->indexcol = indexcol;
3542 : :
3543 [ + + ]: 93 : if (var_on_left)
3544 : : {
3545 : 81 : var_args = clause->largs;
3546 : 81 : non_var_args = clause->rargs;
3547 : : }
3548 : : else
3549 : : {
3550 : 12 : var_args = clause->rargs;
3551 : 12 : non_var_args = clause->largs;
3552 : : }
3553 : :
3554 : 93 : get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false,
3555 : : &op_strategy,
3556 : : &op_lefttype,
3557 : : &op_righttype);
3558 : :
3559 : : /* Initialize returned list of which index columns are used */
3560 : 93 : iclause->indexcols = list_make1_int(indexcol);
3561 : :
3562 : : /* Build lists of ops, opfamilies and operator datatypes in case needed */
3563 : 93 : expr_ops = list_make1_oid(expr_op);
3564 : 93 : opfamilies = list_make1_oid(index->opfamily[indexcol]);
3565 : 93 : lefttypes = list_make1_oid(op_lefttype);
3566 : 93 : righttypes = list_make1_oid(op_righttype);
3567 : :
3568 : : /*
3569 : : * See how many of the remaining columns match some index column in the
3570 : : * same way. As in match_clause_to_indexcol(), the "other" side of any
3571 : : * potential index condition is OK as long as it doesn't use Vars from the
3572 : : * indexed relation.
3573 : : */
3574 : 93 : matching_cols = 1;
3575 : :
2245 3576 [ + + ]: 177 : while (matching_cols < list_length(var_args))
3577 : : {
3578 : 111 : Node *varop = (Node *) list_nth(var_args, matching_cols);
3579 : 111 : Node *constop = (Node *) list_nth(non_var_args, matching_cols);
3580 : : int i;
3581 : :
3582 : 111 : expr_op = list_nth_oid(clause->opnos, matching_cols);
2399 3583 [ + + ]: 111 : if (!var_on_left)
3584 : : {
3585 : : /* indexkey is on right, so commute the operator */
3586 : 12 : expr_op = get_commutator(expr_op);
3587 [ - + ]: 12 : if (expr_op == InvalidOid)
2399 tgl@sss.pgh.pa.us 3588 :UBC 0 : break; /* operator is not usable */
3589 : : }
1689 tgl@sss.pgh.pa.us 3590 [ - + ]:CBC 111 : if (bms_is_member(index->rel->relid, pull_varnos(root, constop)))
2399 tgl@sss.pgh.pa.us 3591 :UBC 0 : break; /* no good, Var on wrong side */
2399 tgl@sss.pgh.pa.us 3592 [ - + ]:CBC 111 : if (contain_volatile_functions(constop))
2399 tgl@sss.pgh.pa.us 3593 :UBC 0 : break; /* no good, volatile comparison value */
3594 : :
3595 : : /*
3596 : : * The Var side can match any key column of the index.
3597 : : */
2399 tgl@sss.pgh.pa.us 3598 [ + + ]:CBC 258 : for (i = 0; i < index->nkeycolumns; i++)
3599 : : {
3600 [ + + ]: 231 : if (match_index_to_operand(varop, i, index) &&
3601 : 84 : get_op_opfamily_strategy(expr_op,
3602 [ + - ]: 84 : index->opfamily[i]) == op_strategy &&
3603 [ + + - + ]: 84 : IndexCollMatchesExprColl(index->indexcollations[i],
3604 : : list_nth_oid(clause->inputcollids,
3605 : : matching_cols)))
3606 : : break;
3607 : : }
3608 [ + + ]: 111 : if (i >= index->nkeycolumns)
3609 : 27 : break; /* no match found */
3610 : :
3611 : : /* Add column number to returned list */
3612 : 84 : iclause->indexcols = lappend_int(iclause->indexcols, i);
3613 : :
3614 : : /* Add operator info to lists */
3615 : 84 : get_op_opfamily_properties(expr_op, index->opfamily[i], false,
3616 : : &op_strategy,
3617 : : &op_lefttype,
3618 : : &op_righttype);
3619 : 84 : expr_ops = lappend_oid(expr_ops, expr_op);
3620 : 84 : opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
3621 : 84 : lefttypes = lappend_oid(lefttypes, op_lefttype);
3622 : 84 : righttypes = lappend_oid(righttypes, op_righttype);
3623 : :
3624 : : /* This column matches, keep scanning */
3625 : 84 : matching_cols++;
3626 : : }
3627 : :
3628 : : /* Result is non-lossy if all columns are usable as index quals */
3629 : 93 : iclause->lossy = (matching_cols != list_length(clause->opnos));
3630 : :
3631 : : /*
3632 : : * We can use rinfo->clause as-is if we have var on left and it's all
3633 : : * usable as index quals.
3634 : : */
3635 [ + + + + ]: 93 : if (var_on_left && !iclause->lossy)
2396 3636 : 60 : iclause->indexquals = list_make1(rinfo);
3637 : : else
3638 : : {
3639 : : /*
3640 : : * We have to generate a modified rowcompare (possibly just one
3641 : : * OpExpr). The painful part of this is changing < to <= or > to >=,
3642 : : * so deal with that first.
3643 : : */
2399 3644 [ + + ]: 33 : if (!iclause->lossy)
3645 : : {
3646 : : /* very easy, just use the commuted operators */
3647 : 6 : new_ops = expr_ops;
3648 : : }
3649 [ + - ]: 27 : else if (op_strategy == BTLessEqualStrategyNumber ||
3650 [ - + ]: 27 : op_strategy == BTGreaterEqualStrategyNumber)
3651 : : {
3652 : : /* easy, just use the same (possibly commuted) operators */
2399 tgl@sss.pgh.pa.us 3653 :UBC 0 : new_ops = list_truncate(expr_ops, matching_cols);
3654 : : }
3655 : : else
3656 : : {
3657 : : ListCell *opfamilies_cell;
3658 : : ListCell *lefttypes_cell;
3659 : : ListCell *righttypes_cell;
3660 : :
2399 tgl@sss.pgh.pa.us 3661 [ + + ]:CBC 27 : if (op_strategy == BTLessStrategyNumber)
3662 : 15 : op_strategy = BTLessEqualStrategyNumber;
3663 [ + - ]: 12 : else if (op_strategy == BTGreaterStrategyNumber)
3664 : 12 : op_strategy = BTGreaterEqualStrategyNumber;
3665 : : else
2399 tgl@sss.pgh.pa.us 3666 [ # # ]:UBC 0 : elog(ERROR, "unexpected strategy number %d", op_strategy);
2399 tgl@sss.pgh.pa.us 3667 :CBC 27 : new_ops = NIL;
3668 [ + - + + : 72 : forthree(opfamilies_cell, opfamilies,
+ - + + +
- + + + +
+ - + - +
+ ]
3669 : : lefttypes_cell, lefttypes,
3670 : : righttypes_cell, righttypes)
3671 : : {
3672 : 45 : Oid opfam = lfirst_oid(opfamilies_cell);
3673 : 45 : Oid lefttype = lfirst_oid(lefttypes_cell);
3674 : 45 : Oid righttype = lfirst_oid(righttypes_cell);
3675 : :
3676 : 45 : expr_op = get_opfamily_member(opfam, lefttype, righttype,
3677 : : op_strategy);
3678 [ - + ]: 45 : if (!OidIsValid(expr_op)) /* should not happen */
2399 tgl@sss.pgh.pa.us 3679 [ # # ]:UBC 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3680 : : op_strategy, lefttype, righttype, opfam);
2399 tgl@sss.pgh.pa.us 3681 :CBC 45 : new_ops = lappend_oid(new_ops, expr_op);
3682 : : }
3683 : : }
3684 : :
3685 : : /* If we have more than one matching col, create a subset rowcompare */
3686 [ + + ]: 33 : if (matching_cols > 1)
3687 : : {
3688 : 24 : RowCompareExpr *rc = makeNode(RowCompareExpr);
3689 : :
234 peter@eisentraut.org 3690 : 24 : rc->cmptype = (CompareType) op_strategy;
2399 tgl@sss.pgh.pa.us 3691 : 24 : rc->opnos = new_ops;
1151 drowley@postgresql.o 3692 : 24 : rc->opfamilies = list_copy_head(clause->opfamilies,
3693 : : matching_cols);
3694 : 24 : rc->inputcollids = list_copy_head(clause->inputcollids,
3695 : : matching_cols);
3696 : 24 : rc->largs = list_copy_head(var_args, matching_cols);
3697 : 24 : rc->rargs = list_copy_head(non_var_args, matching_cols);
1689 tgl@sss.pgh.pa.us 3698 : 24 : iclause->indexquals = list_make1(make_simple_restrictinfo(root,
3699 : : (Expr *) rc));
3700 : : }
3701 : : else
3702 : : {
3703 : : Expr *op;
3704 : :
3705 : : /* We don't report an index column list in this case */
2399 3706 : 9 : iclause->indexcols = NIL;
3707 : :
3708 : 9 : op = make_opclause(linitial_oid(new_ops), BOOLOID, false,
3709 : 9 : copyObject(linitial(var_args)),
3710 : 9 : copyObject(linitial(non_var_args)),
3711 : : InvalidOid,
3712 : 9 : linitial_oid(clause->inputcollids));
1689 3713 : 9 : iclause->indexquals = list_make1(make_simple_restrictinfo(root, op));
3714 : : }
3715 : : }
3716 : :
2399 3717 : 93 : return iclause;
3718 : : }
3719 : :
3720 : :
3721 : : /****************************************************************************
3722 : : * ---- ROUTINES TO CHECK ORDERING OPERATORS ----
3723 : : ****************************************************************************/
3724 : :
3725 : : /*
3726 : : * match_pathkeys_to_index
3727 : : * For the given 'index' and 'pathkeys', output a list of suitable ORDER
3728 : : * BY expressions, each of the form "indexedcol operator pseudoconstant",
3729 : : * along with an integer list of the index column numbers (zero based)
3730 : : * that each clause would be used with.
3731 : : *
3732 : : * This attempts to find an ORDER BY and index column number for all items in
3733 : : * the pathkey list, however, if we're unable to match any given pathkey to an
3734 : : * index column, we return just the ones matched by the function so far. This
3735 : : * allows callers who are interested in partial matches to get them. Callers
3736 : : * can determine a partial match vs a full match by checking the outputted
3737 : : * list lengths. A full match will have one item in the output lists for each
3738 : : * item in the given 'pathkeys' list.
3739 : : */
3740 : : static void
5005 3741 : 537 : match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys,
3742 : : List **orderby_clauses_p,
3743 : : List **clause_columns_p)
3744 : : {
3745 : : ListCell *lc1;
3746 : :
4836 bruce@momjian.us 3747 : 537 : *orderby_clauses_p = NIL; /* set default results */
5005 tgl@sss.pgh.pa.us 3748 : 537 : *clause_columns_p = NIL;
3749 : :
3750 : : /* Only indexes with the amcanorderbyop property are interesting here */
5392 3751 [ - + ]: 537 : if (!index->amcanorderbyop)
5005 tgl@sss.pgh.pa.us 3752 :UBC 0 : return;
3753 : :
5392 tgl@sss.pgh.pa.us 3754 [ + + + + :CBC 774 : foreach(lc1, pathkeys)
+ + ]
3755 : : {
5263 bruce@momjian.us 3756 : 540 : PathKey *pathkey = (PathKey *) lfirst(lc1);
5392 tgl@sss.pgh.pa.us 3757 : 540 : bool found = false;
3758 : : EquivalenceMemberIterator it;
3759 : : EquivalenceMember *member;
3760 : :
3761 : :
3762 : : /* Pathkey must request default sort order for the target opfamily */
155 peter@eisentraut.org 3763 [ + + - + ]: 540 : if (pathkey->pk_cmptype != COMPARE_LT || pathkey->pk_nulls_first)
5005 tgl@sss.pgh.pa.us 3764 : 303 : return;
3765 : :
3766 : : /* If eclass is volatile, no hope of using an indexscan */
5392 3767 [ - + ]: 523 : if (pathkey->pk_eclass->ec_has_volatile)
5005 tgl@sss.pgh.pa.us 3768 :UBC 0 : return;
3769 : :
3770 : : /*
3771 : : * Try to match eclass member expression(s) to index. Note that child
3772 : : * EC members are considered, but only when they belong to the target
3773 : : * relation. (Unlike regular members, the same expression could be a
3774 : : * child member of more than one EC. Therefore, the same index could
3775 : : * be considered to match more than one pathkey list, which is OK
3776 : : * here. See also get_eclass_for_sort_expr.)
3777 : : */
151 drowley@postgresql.o 3778 :CBC 523 : setup_eclass_member_iterator(&it, pathkey->pk_eclass,
3779 : 523 : index->rel->relids);
3780 [ + + ]: 825 : while ((member = eclass_member_iterator_next(&it)) != NULL)
3781 : : {
3782 : : int indexcol;
3783 : :
3784 : : /* No possibility of match if it references other relations */
5392 tgl@sss.pgh.pa.us 3785 [ + + ]: 539 : if (!bms_equal(member->em_relids, index->rel->relids))
3786 : 16 : continue;
3787 : :
3788 : : /*
3789 : : * We allow any column of the index to match each pathkey; they
3790 : : * don't have to match left-to-right as you might expect. This is
3791 : : * correct for GiST, and it doesn't matter for SP-GiST because
3792 : : * that doesn't handle multiple columns anyway, and no other
3793 : : * existing AMs support amcanorderbyop. We might need different
3794 : : * logic in future for other implementations.
3795 : : */
2398 3796 [ + + ]: 953 : for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++)
3797 : : {
3798 : : Expr *expr;
3799 : :
5392 3800 : 667 : expr = match_clause_to_ordering_op(index,
3801 : : indexcol,
3802 : : member->em_expr,
3803 : : pathkey->pk_opfamily);
3804 [ + + ]: 667 : if (expr)
3805 : : {
795 drowley@postgresql.o 3806 : 237 : *orderby_clauses_p = lappend(*orderby_clauses_p, expr);
3807 : 237 : *clause_columns_p = lappend_int(*clause_columns_p, indexcol);
5392 tgl@sss.pgh.pa.us 3808 : 237 : found = true;
3809 : 237 : break;
3810 : : }
3811 : : }
3812 : :
3813 [ + + ]: 523 : if (found) /* don't want to look at remaining members */
3814 : 237 : break;
3815 : : }
3816 : :
3817 : : /*
3818 : : * Return the matches found so far when this pathkey couldn't be
3819 : : * matched to the index.
3820 : : */
795 drowley@postgresql.o 3821 [ + + ]: 523 : if (!found)
5005 tgl@sss.pgh.pa.us 3822 : 286 : return;
3823 : : }
3824 : : }
3825 : :
3826 : : /*
3827 : : * match_clause_to_ordering_op
3828 : : * Determines whether an ordering operator expression matches an
3829 : : * index column.
3830 : : *
3831 : : * This is similar to, but simpler than, match_clause_to_indexcol.
3832 : : * We only care about simple OpExpr cases. The input is a bare
3833 : : * expression that is being ordered by, which must be of the form
3834 : : * (indexkey op const) or (const op indexkey) where op is an ordering
3835 : : * operator for the column's opfamily.
3836 : : *
3837 : : * 'index' is the index of interest.
3838 : : * 'indexcol' is a column number of 'index' (counting from 0).
3839 : : * 'clause' is the ordering expression to be tested.
3840 : : * 'pk_opfamily' is the btree opfamily describing the required sort order.
3841 : : *
3842 : : * Note that we currently do not consider the collation of the ordering
3843 : : * operator's result. In practical cases the result type will be numeric
3844 : : * and thus have no collation, and it's not very clear what to match to
3845 : : * if it did have a collation. The index's collation should match the
3846 : : * ordering operator's input collation, not its result.
3847 : : *
3848 : : * If successful, return 'clause' as-is if the indexkey is on the left,
3849 : : * otherwise a commuted copy of 'clause'. If no match, return NULL.
3850 : : */
3851 : : static Expr *
5392 3852 : 667 : match_clause_to_ordering_op(IndexOptInfo *index,
3853 : : int indexcol,
3854 : : Expr *clause,
3855 : : Oid pk_opfamily)
3856 : : {
3857 : : Oid opfamily;
3858 : : Oid idxcollation;
3859 : : Node *leftop,
3860 : : *rightop;
3861 : : Oid expr_op;
3862 : : Oid expr_coll;
3863 : : Oid sortfamily;
3864 : : bool commuted;
3865 : :
2704 teodor@sigaev.ru 3866 [ - + ]: 667 : Assert(indexcol < index->nkeycolumns);
3867 : :
3868 : 667 : opfamily = index->opfamily[indexcol];
3869 : 667 : idxcollation = index->indexcollations[indexcol];
3870 : :
3871 : : /*
3872 : : * Clause must be a binary opclause.
3873 : : */
5392 tgl@sss.pgh.pa.us 3874 [ + + ]: 667 : if (!is_opclause(clause))
3875 : 430 : return NULL;
3876 : 237 : leftop = get_leftop(clause);
3877 : 237 : rightop = get_rightop(clause);
3878 [ + - - + ]: 237 : if (!leftop || !rightop)
5392 tgl@sss.pgh.pa.us 3879 :UBC 0 : return NULL;
5392 tgl@sss.pgh.pa.us 3880 :CBC 237 : expr_op = ((OpExpr *) clause)->opno;
5265 3881 : 237 : expr_coll = ((OpExpr *) clause)->inputcollid;
3882 : :
3883 : : /*
3884 : : * We can forget the whole thing right away if wrong collation.
3885 : : */
5091 3886 [ + + - + ]: 237 : if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
5265 tgl@sss.pgh.pa.us 3887 :UBC 0 : return NULL;
3888 : :
3889 : : /*
3890 : : * Check for clauses of the form: (indexkey operator constant) or
3891 : : * (constant operator indexkey).
3892 : : */
5392 tgl@sss.pgh.pa.us 3893 [ + + ]:CBC 237 : if (match_index_to_operand(leftop, indexcol, index) &&
3894 [ + - ]: 225 : !contain_var_clause(rightop) &&
3895 [ + - ]: 225 : !contain_volatile_functions(rightop))
3896 : : {
3897 : 225 : commuted = false;
3898 : : }
3899 [ + - ]: 12 : else if (match_index_to_operand(rightop, indexcol, index) &&
3900 [ + - ]: 12 : !contain_var_clause(leftop) &&
3901 [ + - ]: 12 : !contain_volatile_functions(leftop))
3902 : : {
3903 : : /* Might match, but we need a commuted operator */
3904 : 12 : expr_op = get_commutator(expr_op);
3905 [ - + ]: 12 : if (expr_op == InvalidOid)
5392 tgl@sss.pgh.pa.us 3906 :UBC 0 : return NULL;
5392 tgl@sss.pgh.pa.us 3907 :CBC 12 : commuted = true;
3908 : : }
3909 : : else
5392 tgl@sss.pgh.pa.us 3910 :UBC 0 : return NULL;
3911 : :
3912 : : /*
3913 : : * Is the (commuted) operator an ordering operator for the opfamily? And
3914 : : * if so, does it yield the right sorting semantics?
3915 : : */
5392 tgl@sss.pgh.pa.us 3916 :CBC 237 : sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
3917 [ - + ]: 237 : if (sortfamily != pk_opfamily)
5392 tgl@sss.pgh.pa.us 3918 :UBC 0 : return NULL;
3919 : :
3920 : : /* We have a match. Return clause or a commuted version thereof. */
5392 tgl@sss.pgh.pa.us 3921 [ + + ]:CBC 237 : if (commuted)
3922 : : {
3923 : 12 : OpExpr *newclause = makeNode(OpExpr);
3924 : :
3925 : : /* flat-copy all the fields of clause */
3926 : 12 : memcpy(newclause, clause, sizeof(OpExpr));
3927 : :
3928 : : /* commute it */
3929 : 12 : newclause->opno = expr_op;
3930 : 12 : newclause->opfuncid = InvalidOid;
3931 : 12 : newclause->args = list_make2(rightop, leftop);
3932 : :
3933 : 12 : clause = (Expr *) newclause;
3934 : : }
3935 : :
3936 : 237 : return clause;
3937 : : }
3938 : :
3939 : :
3940 : : /****************************************************************************
3941 : : * ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
3942 : : ****************************************************************************/
3943 : :
3944 : : /*
3945 : : * check_index_predicates
3946 : : * Set the predicate-derived IndexOptInfo fields for each index
3947 : : * of the specified relation.
3948 : : *
3949 : : * predOK is set true if the index is partial and its predicate is satisfied
3950 : : * for this query, ie the query's WHERE clauses imply the predicate.
3951 : : *
3952 : : * indrestrictinfo is set to the relation's baserestrictinfo list less any
3953 : : * conditions that are implied by the index's predicate. (Obviously, for a
3954 : : * non-partial index, this is the same as baserestrictinfo.) Such conditions
3955 : : * can be dropped from the plan when using the index, in certain cases.
3956 : : *
3957 : : * At one time it was possible for this to get re-run after adding more
3958 : : * restrictions to the rel, thus possibly letting us prove more indexes OK.
3959 : : * That doesn't happen any more (at least not in the core code's usage),
3960 : : * but this code still supports it in case extensions want to mess with the
3961 : : * baserestrictinfo list. We assume that adding more restrictions can't make
3962 : : * an index not predOK. We must recompute indrestrictinfo each time, though,
3963 : : * to make sure any newly-added restrictions get into it if needed.
3964 : : */
3965 : : void
3446 3966 : 196606 : check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
3967 : : {
3968 : : List *clauselist;
3969 : : bool have_partial;
3970 : : bool is_target_rel;
3971 : : Relids otherrels;
3972 : : ListCell *lc;
3973 : :
3974 : : /* Indexes are available only on base or "other" member relations. */
3078 rhaas@postgresql.org 3975 [ + + - + ]: 196606 : Assert(IS_SIMPLE_REL(rel));
3976 : :
3977 : : /*
3978 : : * Initialize the indrestrictinfo lists to be identical to
3979 : : * baserestrictinfo, and check whether there are any partial indexes. If
3980 : : * not, this is all we need to do.
3981 : : */
4678 tgl@sss.pgh.pa.us 3982 : 196606 : have_partial = false;
3983 [ + + + + : 545888 : foreach(lc, rel->indexlist)
+ + ]
3984 : : {
3985 : 349282 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
3986 : :
3446 3987 : 349282 : index->indrestrictinfo = rel->baserestrictinfo;
3988 [ + + ]: 349282 : if (index->indpred)
3989 : 492 : have_partial = true;
3990 : : }
4678 3991 [ + + ]: 196606 : if (!have_partial)
3992 : 196276 : return;
3993 : :
3994 : : /*
3995 : : * Construct a list of clauses that we can assume true for the purpose of
3996 : : * proving the index(es) usable. Restriction clauses for the rel are
3997 : : * always usable, and so are any join clauses that are "movable to" this
3998 : : * rel. Also, we can consider any EC-derivable join clauses (which must
3999 : : * be "movable to" this rel, by definition).
4000 : : */
4001 : 330 : clauselist = list_copy(rel->baserestrictinfo);
4002 : :
4003 : : /* Scan the rel's join clauses */
4004 [ - + - - : 330 : foreach(lc, rel->joininfo)
- + ]
4005 : : {
4678 tgl@sss.pgh.pa.us 4006 :UBC 0 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4007 : :
4008 : : /* Check if clause can be moved to this rel */
4403 4009 [ # # ]: 0 : if (!join_clause_is_movable_to(rinfo, rel))
4678 4010 : 0 : continue;
4011 : :
4012 : 0 : clauselist = lappend(clauselist, rinfo);
4013 : : }
4014 : :
4015 : : /*
4016 : : * Add on any equivalence-derivable join clauses. Computing the correct
4017 : : * relid sets for generate_join_implied_equalities is slightly tricky
4018 : : * because the rel could be a child rel rather than a true baserel, and in
4019 : : * that case we must subtract its parents' relid(s) from all_query_rels.
4020 : : * Additionally, we mustn't consider clauses that are only computable
4021 : : * after outer joins that can null the rel.
4022 : : */
4678 tgl@sss.pgh.pa.us 4023 [ + + ]:CBC 330 : if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
950 4024 : 36 : otherrels = bms_difference(root->all_query_rels,
3993 4025 : 36 : find_childrel_parents(root, rel));
4026 : : else
950 4027 : 294 : otherrels = bms_difference(root->all_query_rels, rel->relids);
926 4028 : 330 : otherrels = bms_del_members(otherrels, rel->nulling_relids);
4029 : :
4678 4030 [ + + ]: 330 : if (!bms_is_empty(otherrels))
4031 : : clauselist =
4032 : 44 : list_concat(clauselist,
4033 : 44 : generate_join_implied_equalities(root,
2999 4034 : 44 : bms_union(rel->relids,
4035 : : otherrels),
4036 : : otherrels,
4037 : : rel,
4038 : : NULL));
4039 : :
4040 : : /*
4041 : : * Normally we remove quals that are implied by a partial index's
4042 : : * predicate from indrestrictinfo, indicating that they need not be
4043 : : * checked explicitly by an indexscan plan using this index. However, if
4044 : : * the rel is a target relation of UPDATE/DELETE/MERGE/SELECT FOR UPDATE,
4045 : : * we cannot remove such quals from the plan, because they need to be in
4046 : : * the plan so that they will be properly rechecked by EvalPlanQual
4047 : : * testing. Some day we might want to remove such quals from the main
4048 : : * plan anyway and pass them through to EvalPlanQual via a side channel;
4049 : : * but for now, we just don't remove implied quals at all for target
4050 : : * relations.
4051 : : */
1620 4052 [ + + + + ]: 604 : is_target_rel = (bms_is_member(rel->relid, root->all_result_relids) ||
3446 4053 : 274 : get_plan_rowmark(root->rowMarks, rel->relid) != NULL);
4054 : :
4055 : : /*
4056 : : * Now try to prove each index predicate true, and compute the
4057 : : * indrestrictinfo lists for partial indexes. Note that we compute the
4058 : : * indrestrictinfo list even for non-predOK indexes; this might seem
4059 : : * wasteful, but we may be able to use such indexes in OR clauses, cf
4060 : : * generate_bitmap_or_paths().
4061 : : */
4678 4062 [ + - + + : 1015 : foreach(lc, rel->indexlist)
+ + ]
4063 : : {
4064 : 685 : IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
4065 : : ListCell *lcr;
4066 : :
7393 4067 [ + + ]: 685 : if (index->indpred == NIL)
3446 4068 : 193 : continue; /* ignore non-partial indexes here */
4069 : :
4070 [ + - ]: 492 : if (!index->predOK) /* don't repeat work if already proven OK */
3006 rhaas@postgresql.org 4071 : 492 : index->predOK = predicate_implied_by(index->indpred, clauselist,
4072 : : false);
4073 : :
4074 : : /* If rel is an update target, leave indrestrictinfo as set above */
3446 tgl@sss.pgh.pa.us 4075 [ + + ]: 492 : if (is_target_rel)
4076 : 86 : continue;
4077 : :
4078 : : /* Else compute indrestrictinfo as the non-implied quals */
4079 : 406 : index->indrestrictinfo = NIL;
4080 [ + + + + : 957 : foreach(lcr, rel->baserestrictinfo)
+ + ]
4081 : : {
4082 : 551 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcr);
4083 : :
4084 : : /* predicate_implied_by() assumes first arg is immutable */
4085 [ + - ]: 551 : if (contain_mutable_functions((Node *) rinfo->clause) ||
4086 [ + + ]: 551 : !predicate_implied_by(list_make1(rinfo->clause),
4087 : : index->indpred, false))
4088 : 391 : index->indrestrictinfo = lappend(index->indrestrictinfo, rinfo);
4089 : : }
4090 : : }
4091 : : }
4092 : :
4093 : : /****************************************************************************
4094 : : * ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
4095 : : ****************************************************************************/
4096 : :
4097 : : /*
4098 : : * ec_member_matches_indexcol
4099 : : * Test whether an EquivalenceClass member matches an index column.
4100 : : *
4101 : : * This is a callback for use by generate_implied_equalities_for_column.
4102 : : */
4103 : : static bool
4552 4104 : 203557 : ec_member_matches_indexcol(PlannerInfo *root, RelOptInfo *rel,
4105 : : EquivalenceClass *ec, EquivalenceMember *em,
4106 : : void *arg)
4107 : : {
4108 : 203557 : IndexOptInfo *index = ((ec_member_matches_arg *) arg)->index;
4109 : 203557 : int indexcol = ((ec_member_matches_arg *) arg)->indexcol;
4110 : : Oid curFamily;
4111 : : Oid curCollation;
4112 : :
2704 teodor@sigaev.ru 4113 [ - + ]: 203557 : Assert(indexcol < index->nkeycolumns);
4114 : :
4115 : 203557 : curFamily = index->opfamily[indexcol];
4116 : 203557 : curCollation = index->indexcollations[indexcol];
4117 : :
4118 : : /*
4119 : : * If it's a btree index, we can reject it if its opfamily isn't
4120 : : * compatible with the EC, since no clause generated from the EC could be
4121 : : * used with the index. For non-btree indexes, we can't easily tell
4122 : : * whether clauses generated from the EC could be used with the index, so
4123 : : * don't check the opfamily. This might mean we return "true" for a
4124 : : * useless EC, so we have to recheck the results of
4125 : : * generate_implied_equalities_for_column; see
4126 : : * match_eclass_clauses_to_index.
4127 : : */
4971 tgl@sss.pgh.pa.us 4128 [ + + ]: 203557 : if (index->relam == BTREE_AM_OID &&
4129 [ + + ]: 203536 : !list_member_oid(ec->ec_opfamilies, curFamily))
4130 : 61640 : return false;
4131 : :
4132 : : /* We insist on collation match for all index types, though */
4133 [ + + + + ]: 141917 : if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
4134 : 9 : return false;
4135 : :
4136 : 141908 : return match_index_to_operand((Node *) em->em_expr, indexcol, index);
4137 : : }
4138 : :
4139 : : /*
4140 : : * relation_has_unique_index_for
4141 : : * Determine whether the relation provably has at most one row satisfying
4142 : : * a set of equality conditions, because the conditions constrain all
4143 : : * columns of some unique index.
4144 : : *
4145 : : * The conditions are provided as a list of RestrictInfo nodes, where the
4146 : : * caller has already determined that each condition is a mergejoinable
4147 : : * equality with an expression in this relation on one side, and an
4148 : : * expression not involving this relation on the other. The transient
4149 : : * outer_is_left flag is used to identify which side we should look at:
4150 : : * left side if outer_is_left is false, right side if it is true.
4151 : : *
4152 : : * The caller need only supply equality conditions arising from joins;
4153 : : * this routine automatically adds in any usable baserestrictinfo clauses.
4154 : : * (Note that the passed-in restrictlist will be destructively modified!)
4155 : : *
4156 : : * If extra_clauses isn't NULL, return baserestrictinfo clauses which were used
4157 : : * to derive uniqueness.
4158 : : */
4159 : : bool
5833 4160 : 99900 : relation_has_unique_index_for(PlannerInfo *root, RelOptInfo *rel,
4161 : : List *restrictlist, List **extra_clauses)
4162 : : {
4163 : : ListCell *ic;
4164 : :
4165 : : /* Short-circuit if no indexes... */
5064 4166 [ - + ]: 99900 : if (rel->indexlist == NIL)
5064 tgl@sss.pgh.pa.us 4167 :LBC (227) : return false;
4168 : :
4169 : : /*
4170 : : * Examine the rel's restriction clauses for usable var = const clauses
4171 : : * that we can add to the restrictlist.
4172 : : */
5064 tgl@sss.pgh.pa.us 4173 [ + + + + :CBC 167367 : foreach(ic, rel->baserestrictinfo)
+ + ]
4174 : : {
4175 : 67467 : RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(ic);
4176 : :
4177 : : /*
4178 : : * Note: can_join won't be set for a restriction clause, but
4179 : : * mergeopfamilies will be if it has a mergejoinable operator and
4180 : : * doesn't contain volatile functions.
4181 : : */
4182 [ + + ]: 67467 : if (restrictinfo->mergeopfamilies == NIL)
4183 : 27449 : continue; /* not mergejoinable */
4184 : :
4185 : : /*
4186 : : * The clause certainly doesn't refer to anything but the given rel.
4187 : : * If either side is pseudoconstant then we can use it.
4188 : : */
4189 [ + + ]: 40018 : if (bms_is_empty(restrictinfo->left_relids))
4190 : : {
4191 : : /* righthand side is inner */
4192 : 30 : restrictinfo->outer_is_left = true;
4193 : : }
4194 [ + + ]: 39988 : else if (bms_is_empty(restrictinfo->right_relids))
4195 : : {
4196 : : /* lefthand side is inner */
4197 : 39925 : restrictinfo->outer_is_left = false;
4198 : : }
4199 : : else
4200 : 63 : continue;
4201 : :
4202 : : /* OK, add to list */
4203 : 39955 : restrictlist = lappend(restrictlist, restrictinfo);
4204 : : }
4205 : :
4206 : : /* Short-circuit the easy case */
18 rguo@postgresql.org 4207 [ + + ]:GNC 99900 : if (restrictlist == NIL)
5833 tgl@sss.pgh.pa.us 4208 :CBC 551 : return false;
4209 : :
4210 : : /* Examine each index of the relation ... */
4211 [ + - + + : 257875 : foreach(ic, rel->indexlist)
+ + ]
4212 : : {
5671 bruce@momjian.us 4213 : 216381 : IndexOptInfo *ind = (IndexOptInfo *) lfirst(ic);
4214 : : int c;
205 akorotkov@postgresql 4215 : 216381 : List *exprs = NIL;
4216 : :
4217 : : /*
4218 : : * If the index is not unique, or not immediately enforced, or if it's
4219 : : * a partial index, it's useless here. We're unable to make use of
4220 : : * predOK partial unique indexes due to the fact that
4221 : : * check_index_predicates() also makes use of join predicates to
4222 : : * determine if the partial index is usable. Here we need proofs that
4223 : : * hold true before any joins are evaluated.
4224 : : */
810 drowley@postgresql.o 4225 [ + + + - : 216381 : if (!ind->unique || !ind->immediate || ind->indpred != NIL)
+ + ]
5833 tgl@sss.pgh.pa.us 4226 : 61316 : continue;
4227 : :
4228 : : /*
4229 : : * Try to find each index column in the list of conditions. This is
4230 : : * O(N^2) or worse, but we expect all the lists to be short.
4231 : : */
2398 4232 [ + + ]: 252924 : for (c = 0; c < ind->nkeycolumns; c++)
4233 : : {
4234 : : ListCell *lc;
4235 : :
5833 4236 [ + - + + : 375789 : foreach(lc, restrictlist)
+ + ]
4237 : : {
5671 bruce@momjian.us 4238 : 278579 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4239 : : Node *rexpr;
4240 : :
4241 : : /*
4242 : : * The condition's equality operator must be a member of the
4243 : : * index opfamily, else it is not asserting the right kind of
4244 : : * equality behavior for this index. We check this first
4245 : : * since it's probably cheaper than match_index_to_operand().
4246 : : */
5833 tgl@sss.pgh.pa.us 4247 [ + + ]: 278579 : if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
4248 : 78668 : continue;
4249 : :
4250 : : /*
4251 : : * XXX at some point we may need to check collations here too.
4252 : : * For the moment we assume all collations reduce to the same
4253 : : * notion of equality.
4254 : : */
4255 : :
4256 : : /* OK, see if the condition operand matches the index key */
4257 [ + + ]: 199911 : if (rinfo->outer_is_left)
4258 : 81756 : rexpr = get_rightop(rinfo->clause);
4259 : : else
4260 : 118155 : rexpr = get_leftop(rinfo->clause);
4261 : :
4262 [ + + ]: 199911 : if (match_index_to_operand(rexpr, c, ind))
4263 : : {
205 akorotkov@postgresql 4264 [ + + ]: 97859 : if (bms_membership(rinfo->clause_relids) == BMS_SINGLETON)
4265 : : {
4266 : : MemoryContext oldMemCtx =
4267 : 24174 : MemoryContextSwitchTo(root->planner_cxt);
4268 : :
4269 : : /*
4270 : : * Add filter clause into a list allowing caller to
4271 : : * know if uniqueness have made not only by join
4272 : : * clauses.
4273 : : */
4274 [ + + - + ]: 24174 : Assert(bms_is_empty(rinfo->left_relids) ||
4275 : : bms_is_empty(rinfo->right_relids));
4276 [ + + ]: 24174 : if (extra_clauses)
4277 : 72 : exprs = lappend(exprs, rinfo);
4278 : 24174 : MemoryContextSwitchTo(oldMemCtx);
4279 : : }
4280 : :
18 rguo@postgresql.org 4281 :GNC 97859 : break; /* found a match; column is unique */
4282 : : }
4283 : : }
4284 : :
4285 [ + + ]: 195069 : if (lc == NULL)
5833 tgl@sss.pgh.pa.us 4286 :CBC 97210 : break; /* no match; this index doesn't help us */
4287 : : }
4288 : :
4289 : : /* Matched all key columns of this index? */
2398 4290 [ + + ]: 155065 : if (c == ind->nkeycolumns)
4291 : : {
205 akorotkov@postgresql 4292 [ + + ]: 57855 : if (extra_clauses)
4293 : 327 : *extra_clauses = exprs;
5833 tgl@sss.pgh.pa.us 4294 : 57855 : return true;
4295 : : }
4296 : : }
4297 : :
4298 : 41494 : return false;
4299 : : }
4300 : :
4301 : : /*
4302 : : * indexcol_is_bool_constant_for_query
4303 : : *
4304 : : * If an index column is constrained to have a constant value by the query's
4305 : : * WHERE conditions, then it's irrelevant for sort-order considerations.
4306 : : * Usually that means we have a restriction clause WHERE indexcol = constant,
4307 : : * which gets turned into an EquivalenceClass containing a constant, which
4308 : : * is recognized as redundant by build_index_pathkeys(). But if the index
4309 : : * column is a boolean variable (or expression), then we are not going to
4310 : : * see WHERE indexcol = constant, because expression preprocessing will have
4311 : : * simplified that to "WHERE indexcol" or "WHERE NOT indexcol". So we are not
4312 : : * going to have a matching EquivalenceClass (unless the query also contains
4313 : : * "ORDER BY indexcol"). To allow such cases to work the same as they would
4314 : : * for non-boolean values, this function is provided to detect whether the
4315 : : * specified index column matches a boolean restriction clause.
4316 : : */
4317 : : bool
1689 4318 : 309240 : indexcol_is_bool_constant_for_query(PlannerInfo *root,
4319 : : IndexOptInfo *index,
4320 : : int indexcol)
4321 : : {
4322 : : ListCell *lc;
4323 : :
4324 : : /* If the index isn't boolean, we can't possibly get a match */
3156 4325 [ + + ]: 309240 : if (!IsBooleanOpfamily(index->opfamily[indexcol]))
4326 : 307708 : return false;
4327 : :
4328 : : /* Check each restriction clause for the index's rel */
4329 [ + + + + : 1550 : foreach(lc, index->rel->baserestrictinfo)
+ + ]
4330 : : {
4331 : 638 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4332 : :
4333 : : /*
4334 : : * As in match_clause_to_indexcol, never match pseudoconstants to
4335 : : * indexes. (It might be semantically okay to do so here, but the
4336 : : * odds of getting a match are negligible, so don't waste the cycles.)
4337 : : */
4338 [ - + ]: 638 : if (rinfo->pseudoconstant)
3156 tgl@sss.pgh.pa.us 4339 :UBC 0 : continue;
4340 : :
4341 : : /* See if we can match the clause's expression to the index column */
1689 tgl@sss.pgh.pa.us 4342 [ + + ]:CBC 638 : if (match_boolean_index_clause(root, rinfo, indexcol, index))
3156 4343 : 620 : return true;
4344 : : }
4345 : :
4346 : 912 : return false;
4347 : : }
4348 : :
4349 : :
4350 : : /****************************************************************************
4351 : : * ---- ROUTINES TO CHECK OPERANDS ----
4352 : : ****************************************************************************/
4353 : :
4354 : : /*
4355 : : * match_index_to_operand()
4356 : : * Generalized test for a match between an index's key
4357 : : * and the operand on one side of a restriction or join clause.
4358 : : *
4359 : : * operand: the nodetree to be compared to the index
4360 : : * indexcol: the column number of the index (counting from 0)
4361 : : * index: the index of interest
4362 : : *
4363 : : * Note that we aren't interested in collations here; the caller must check
4364 : : * for a collation match, if it's dealing with an operator where that matters.
4365 : : *
4366 : : * This is exported for use in selfuncs.c.
4367 : : */
4368 : : bool
8137 4369 : 1806643 : match_index_to_operand(Node *operand,
4370 : : int indexcol,
4371 : : IndexOptInfo *index)
4372 : : {
4373 : : int indkey;
4374 : :
4375 : : /*
4376 : : * Ignore any RelabelType node above the operand. This is needed to be
4377 : : * able to apply indexscanning in binary-compatible-operator cases. Note:
4378 : : * we can assume there is at most one RelabelType node;
4379 : : * eval_const_expressions() will have simplified if more than one.
4380 : : */
9155 4381 [ + - + + ]: 1806643 : if (operand && IsA(operand, RelabelType))
8270 4382 : 11242 : operand = (Node *) ((RelabelType *) operand)->arg;
4383 : :
8137 4384 : 1806643 : indkey = index->indexkeys[indexcol];
4385 [ + + ]: 1806643 : if (indkey != 0)
4386 : : {
4387 : : /*
4388 : : * Simple index column; operand must be a matching Var.
4389 : : */
9155 4390 [ + - + + ]: 1803626 : if (operand && IsA(operand, Var) &&
7468 4391 [ + + ]: 1326390 : index->rel->relid == ((Var *) operand)->varno &&
950 4392 [ + + ]: 1236163 : indkey == ((Var *) operand)->varattno &&
4393 [ + + ]: 419045 : ((Var *) operand)->varnullingrels == NULL)
9518 4394 : 418246 : return true;
4395 : : }
4396 : : else
4397 : : {
4398 : : /*
4399 : : * Index expression; find the correct expression. (This search could
4400 : : * be avoided, at the cost of complicating all the callers of this
4401 : : * routine; doesn't seem worth it.)
4402 : : */
4403 : : ListCell *indexpr_item;
4404 : : int i;
4405 : : Node *indexkey;
4406 : :
7773 neilc@samurai.com 4407 : 3017 : indexpr_item = list_head(index->indexprs);
8137 tgl@sss.pgh.pa.us 4408 [ - + ]: 3017 : for (i = 0; i < indexcol; i++)
4409 : : {
8137 tgl@sss.pgh.pa.us 4410 [ # # ]:UBC 0 : if (index->indexkeys[i] == 0)
4411 : : {
7773 neilc@samurai.com 4412 [ # # ]: 0 : if (indexpr_item == NULL)
8137 tgl@sss.pgh.pa.us 4413 [ # # ]: 0 : elog(ERROR, "wrong number of index expressions");
2245 4414 : 0 : indexpr_item = lnext(index->indexprs, indexpr_item);
4415 : : }
4416 : : }
7773 neilc@samurai.com 4417 [ - + ]:CBC 3017 : if (indexpr_item == NULL)
8137 tgl@sss.pgh.pa.us 4418 [ # # ]:UBC 0 : elog(ERROR, "wrong number of index expressions");
7773 neilc@samurai.com 4419 :CBC 3017 : indexkey = (Node *) lfirst(indexpr_item);
4420 : :
4421 : : /*
4422 : : * Does it match the operand? Again, strip any relabeling.
4423 : : */
8137 tgl@sss.pgh.pa.us 4424 [ + - + + ]: 3017 : if (indexkey && IsA(indexkey, RelabelType))
4425 : 5 : indexkey = (Node *) ((RelabelType *) indexkey)->arg;
4426 : :
4427 [ + + ]: 3017 : if (equal(indexkey, operand))
4428 : 1082 : return true;
4429 : : }
4430 : :
4431 : 1387315 : return false;
4432 : : }
4433 : :
4434 : : /*
4435 : : * is_pseudo_constant_for_index()
4436 : : * Test whether the given expression can be used as an indexscan
4437 : : * comparison value.
4438 : : *
4439 : : * An indexscan comparison value must not contain any volatile functions,
4440 : : * and it can't contain any Vars of the index's own table. Vars of
4441 : : * other tables are okay, though; in that case we'd be producing an
4442 : : * indexqual usable in a parameterized indexscan. This is, therefore,
4443 : : * a weaker condition than is_pseudo_constant_clause().
4444 : : *
4445 : : * This function is exported for use by planner support functions,
4446 : : * which will have available the IndexOptInfo, but not any RestrictInfo
4447 : : * infrastructure. It is making the same test made by functions above
4448 : : * such as match_opclause_to_indexcol(), but those rely where possible
4449 : : * on RestrictInfo information about variable membership.
4450 : : *
4451 : : * expr: the nodetree to be checked
4452 : : * index: the index of interest
4453 : : */
4454 : : bool
1689 tgl@sss.pgh.pa.us 4455 :UBC 0 : is_pseudo_constant_for_index(PlannerInfo *root, Node *expr, IndexOptInfo *index)
4456 : : {
4457 : : /* pull_varnos is cheaper than volatility check, so do that first */
4458 [ # # ]: 0 : if (bms_is_member(index->rel->relid, pull_varnos(root, expr)))
2399 4459 : 0 : return false; /* no good, contains Var of table */
4460 [ # # ]: 0 : if (contain_volatile_functions(expr))
4461 : 0 : return false; /* no good, volatile comparison value */
4462 : 0 : return true;
4463 : : }
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