Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * initsplan.c
4 : * Target list, group by, qualification, joininfo initialization routines
5 : *
6 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/optimizer/plan/initsplan.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres.h"
16 :
17 : #include "catalog/pg_constraint.h"
18 : #include "catalog/pg_type.h"
19 : #include "nodes/makefuncs.h"
20 : #include "nodes/nodeFuncs.h"
21 : #include "optimizer/clauses.h"
22 : #include "optimizer/cost.h"
23 : #include "optimizer/inherit.h"
24 : #include "optimizer/joininfo.h"
25 : #include "optimizer/optimizer.h"
26 : #include "optimizer/pathnode.h"
27 : #include "optimizer/paths.h"
28 : #include "optimizer/placeholder.h"
29 : #include "optimizer/planmain.h"
30 : #include "optimizer/planner.h"
31 : #include "optimizer/restrictinfo.h"
32 : #include "parser/analyze.h"
33 : #include "rewrite/rewriteManip.h"
34 : #include "utils/lsyscache.h"
35 : #include "utils/rel.h"
36 : #include "utils/typcache.h"
37 :
38 : /* These parameters are set by GUC */
39 : int from_collapse_limit;
40 : int join_collapse_limit;
41 :
42 :
43 : /*
44 : * deconstruct_jointree requires multiple passes over the join tree, because we
45 : * need to finish computing JoinDomains before we start distributing quals.
46 : * As long as we have to do that, other information such as the relevant
47 : * qualscopes might as well be computed in the first pass too.
48 : *
49 : * deconstruct_recurse recursively examines the join tree and builds a List
50 : * (in depth-first traversal order) of JoinTreeItem structs, which are then
51 : * processed iteratively by deconstruct_distribute. If there are outer
52 : * joins, non-degenerate outer join clauses are processed in a third pass
53 : * deconstruct_distribute_oj_quals.
54 : *
55 : * The JoinTreeItem structs themselves can be freed at the end of
56 : * deconstruct_jointree, but do not modify or free their substructure,
57 : * as the relid sets may also be pointed to by RestrictInfo and
58 : * SpecialJoinInfo nodes.
59 : */
60 : typedef struct JoinTreeItem
61 : {
62 : /* Fields filled during deconstruct_recurse: */
63 : Node *jtnode; /* jointree node to examine */
64 : JoinDomain *jdomain; /* join domain for its ON/WHERE clauses */
65 : struct JoinTreeItem *jti_parent; /* JoinTreeItem for this node's
66 : * parent, or NULL if it's the top */
67 : Relids qualscope; /* base+OJ Relids syntactically included in
68 : * this jointree node */
69 : Relids inner_join_rels; /* base+OJ Relids syntactically included
70 : * in inner joins appearing at or below
71 : * this jointree node */
72 : Relids left_rels; /* if join node, Relids of the left side */
73 : Relids right_rels; /* if join node, Relids of the right side */
74 : Relids nonnullable_rels; /* if outer join, Relids of the
75 : * non-nullable side */
76 : /* Fields filled during deconstruct_distribute: */
77 : SpecialJoinInfo *sjinfo; /* if outer join, its SpecialJoinInfo */
78 : List *oj_joinclauses; /* outer join quals not yet distributed */
79 : List *lateral_clauses; /* quals postponed from children due to
80 : * lateral references */
81 : } JoinTreeItem;
82 :
83 :
84 : static void extract_lateral_references(PlannerInfo *root, RelOptInfo *brel,
85 : Index rtindex);
86 : static List *deconstruct_recurse(PlannerInfo *root, Node *jtnode,
87 : JoinDomain *parent_domain,
88 : JoinTreeItem *parent_jtitem,
89 : List **item_list);
90 : static void deconstruct_distribute(PlannerInfo *root, JoinTreeItem *jtitem);
91 : static void process_security_barrier_quals(PlannerInfo *root,
92 : int rti, JoinTreeItem *jtitem);
93 : static void mark_rels_nulled_by_join(PlannerInfo *root, Index ojrelid,
94 : Relids lower_rels);
95 : static SpecialJoinInfo *make_outerjoininfo(PlannerInfo *root,
96 : Relids left_rels, Relids right_rels,
97 : Relids inner_join_rels,
98 : JoinType jointype, Index ojrelid,
99 : List *clause);
100 : static void compute_semijoin_info(PlannerInfo *root, SpecialJoinInfo *sjinfo,
101 : List *clause);
102 : static void deconstruct_distribute_oj_quals(PlannerInfo *root,
103 : List *jtitems,
104 : JoinTreeItem *jtitem);
105 : static void distribute_quals_to_rels(PlannerInfo *root, List *clauses,
106 : JoinTreeItem *jtitem,
107 : SpecialJoinInfo *sjinfo,
108 : Index security_level,
109 : Relids qualscope,
110 : Relids ojscope,
111 : Relids outerjoin_nonnullable,
112 : Relids incompatible_relids,
113 : bool allow_equivalence,
114 : bool has_clone,
115 : bool is_clone,
116 : List **postponed_oj_qual_list);
117 : static void distribute_qual_to_rels(PlannerInfo *root, Node *clause,
118 : JoinTreeItem *jtitem,
119 : SpecialJoinInfo *sjinfo,
120 : Index security_level,
121 : Relids qualscope,
122 : Relids ojscope,
123 : Relids outerjoin_nonnullable,
124 : Relids incompatible_relids,
125 : bool allow_equivalence,
126 : bool has_clone,
127 : bool is_clone,
128 : List **postponed_oj_qual_list);
129 : static bool check_redundant_nullability_qual(PlannerInfo *root, Node *clause);
130 : static Relids get_join_domain_min_rels(PlannerInfo *root, Relids domain_relids);
131 : static void check_mergejoinable(RestrictInfo *restrictinfo);
132 : static void check_hashjoinable(RestrictInfo *restrictinfo);
133 : static void check_memoizable(RestrictInfo *restrictinfo);
134 :
135 :
136 : /*****************************************************************************
137 : *
138 : * JOIN TREES
139 : *
140 : *****************************************************************************/
141 :
142 : /*
143 : * add_base_rels_to_query
144 : *
145 : * Scan the query's jointree and create baserel RelOptInfos for all
146 : * the base relations (e.g., table, subquery, and function RTEs)
147 : * appearing in the jointree.
148 : *
149 : * The initial invocation must pass root->parse->jointree as the value of
150 : * jtnode. Internally, the function recurses through the jointree.
151 : *
152 : * At the end of this process, there should be one baserel RelOptInfo for
153 : * every non-join RTE that is used in the query. Some of the baserels
154 : * may be appendrel parents, which will require additional "otherrel"
155 : * RelOptInfos for their member rels, but those are added later.
156 : */
157 : void
158 911432 : add_base_rels_to_query(PlannerInfo *root, Node *jtnode)
159 : {
160 911432 : if (jtnode == NULL)
161 0 : return;
162 911432 : if (IsA(jtnode, RangeTblRef))
163 : {
164 474724 : int varno = ((RangeTblRef *) jtnode)->rtindex;
165 :
166 474724 : (void) build_simple_rel(root, varno, NULL);
167 : }
168 436708 : else if (IsA(jtnode, FromExpr))
169 : {
170 340946 : FromExpr *f = (FromExpr *) jtnode;
171 : ListCell *l;
172 :
173 731850 : foreach(l, f->fromlist)
174 390922 : add_base_rels_to_query(root, lfirst(l));
175 : }
176 95762 : else if (IsA(jtnode, JoinExpr))
177 : {
178 95762 : JoinExpr *j = (JoinExpr *) jtnode;
179 :
180 95762 : add_base_rels_to_query(root, j->larg);
181 95762 : add_base_rels_to_query(root, j->rarg);
182 : }
183 : else
184 0 : elog(ERROR, "unrecognized node type: %d",
185 : (int) nodeTag(jtnode));
186 : }
187 :
188 : /*
189 : * add_other_rels_to_query
190 : * create "otherrel" RelOptInfos for the children of appendrel baserels
191 : *
192 : * At the end of this process, there should be RelOptInfos for all relations
193 : * that will be scanned by the query.
194 : */
195 : void
196 328968 : add_other_rels_to_query(PlannerInfo *root)
197 : {
198 : int rti;
199 :
200 999124 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
201 : {
202 670158 : RelOptInfo *rel = root->simple_rel_array[rti];
203 670158 : RangeTblEntry *rte = root->simple_rte_array[rti];
204 :
205 : /* there may be empty slots corresponding to non-baserel RTEs */
206 670158 : if (rel == NULL)
207 156930 : continue;
208 :
209 : /* Ignore any "otherrels" that were already added. */
210 513228 : if (rel->reloptkind != RELOPT_BASEREL)
211 50072 : continue;
212 :
213 : /* If it's marked as inheritable, look for children. */
214 463156 : if (rte->inh)
215 20564 : expand_inherited_rtentry(root, rel, rte, rti);
216 : }
217 328966 : }
218 :
219 :
220 : /*****************************************************************************
221 : *
222 : * TARGET LISTS
223 : *
224 : *****************************************************************************/
225 :
226 : /*
227 : * build_base_rel_tlists
228 : * Add targetlist entries for each var needed in the query's final tlist
229 : * (and HAVING clause, if any) to the appropriate base relations.
230 : *
231 : * We mark such vars as needed by "relation 0" to ensure that they will
232 : * propagate up through all join plan steps.
233 : */
234 : void
235 328998 : build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
236 : {
237 328998 : List *tlist_vars = pull_var_clause((Node *) final_tlist,
238 : PVC_RECURSE_AGGREGATES |
239 : PVC_RECURSE_WINDOWFUNCS |
240 : PVC_INCLUDE_PLACEHOLDERS);
241 :
242 328998 : if (tlist_vars != NIL)
243 : {
244 311778 : add_vars_to_targetlist(root, tlist_vars, bms_make_singleton(0));
245 311778 : list_free(tlist_vars);
246 : }
247 :
248 : /*
249 : * If there's a HAVING clause, we'll need the Vars it uses, too. Note
250 : * that HAVING can contain Aggrefs but not WindowFuncs.
251 : */
252 328998 : if (root->parse->havingQual)
253 : {
254 856 : List *having_vars = pull_var_clause(root->parse->havingQual,
255 : PVC_RECURSE_AGGREGATES |
256 : PVC_INCLUDE_PLACEHOLDERS);
257 :
258 856 : if (having_vars != NIL)
259 : {
260 760 : add_vars_to_targetlist(root, having_vars,
261 : bms_make_singleton(0));
262 760 : list_free(having_vars);
263 : }
264 : }
265 328998 : }
266 :
267 : /*
268 : * add_vars_to_targetlist
269 : * For each variable appearing in the list, add it to the owning
270 : * relation's targetlist if not already present, and mark the variable
271 : * as being needed for the indicated join (or for final output if
272 : * where_needed includes "relation 0").
273 : *
274 : * The list may also contain PlaceHolderVars. These don't necessarily
275 : * have a single owning relation; we keep their attr_needed info in
276 : * root->placeholder_list instead. Find or create the associated
277 : * PlaceHolderInfo entry, and update its ph_needed.
278 : *
279 : * See also add_vars_to_attr_needed.
280 : */
281 : void
282 616928 : add_vars_to_targetlist(PlannerInfo *root, List *vars,
283 : Relids where_needed)
284 : {
285 : ListCell *temp;
286 :
287 : Assert(!bms_is_empty(where_needed));
288 :
289 2240576 : foreach(temp, vars)
290 : {
291 1623648 : Node *node = (Node *) lfirst(temp);
292 :
293 1623648 : if (IsA(node, Var))
294 : {
295 1620624 : Var *var = (Var *) node;
296 1620624 : RelOptInfo *rel = find_base_rel(root, var->varno);
297 1620624 : int attno = var->varattno;
298 :
299 1620624 : if (bms_is_subset(where_needed, rel->relids))
300 1366 : continue;
301 : Assert(attno >= rel->min_attr && attno <= rel->max_attr);
302 1619258 : attno -= rel->min_attr;
303 1619258 : if (rel->attr_needed[attno] == NULL)
304 : {
305 : /*
306 : * Variable not yet requested, so add to rel's targetlist.
307 : *
308 : * The value available at the rel's scan level has not been
309 : * nulled by any outer join, so drop its varnullingrels.
310 : * (We'll put those back as we climb up the join tree.)
311 : */
312 1224442 : var = copyObject(var);
313 1224442 : var->varnullingrels = NULL;
314 1224442 : rel->reltarget->exprs = lappend(rel->reltarget->exprs, var);
315 : /* reltarget cost and width will be computed later */
316 : }
317 1619258 : rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
318 : where_needed);
319 : }
320 3024 : else if (IsA(node, PlaceHolderVar))
321 : {
322 3024 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
323 3024 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
324 :
325 3024 : phinfo->ph_needed = bms_add_members(phinfo->ph_needed,
326 : where_needed);
327 : }
328 : else
329 0 : elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
330 : }
331 616928 : }
332 :
333 : /*
334 : * add_vars_to_attr_needed
335 : * This does a subset of what add_vars_to_targetlist does: it just
336 : * updates attr_needed for Vars and ph_needed for PlaceHolderVars.
337 : * We assume the Vars are already in their relations' targetlists.
338 : *
339 : * This is used to rebuild attr_needed/ph_needed sets after removal
340 : * of a useless outer join. The removed join clause might have been
341 : * the only upper-level use of some other relation's Var, in which
342 : * case we can reduce that Var's attr_needed and thereby possibly
343 : * open the door to further join removals. But we can't tell that
344 : * without tedious reconstruction of the attr_needed data.
345 : *
346 : * Note that if a Var's attr_needed is successfully reduced to empty,
347 : * it will still be in the relation's targetlist even though we do
348 : * not really need the scan plan node to emit it. The extra plan
349 : * inefficiency seems tiny enough to not be worth spending planner
350 : * cycles to get rid of it.
351 : */
352 : void
353 13296 : add_vars_to_attr_needed(PlannerInfo *root, List *vars,
354 : Relids where_needed)
355 : {
356 : ListCell *temp;
357 :
358 : Assert(!bms_is_empty(where_needed));
359 :
360 30728 : foreach(temp, vars)
361 : {
362 17432 : Node *node = (Node *) lfirst(temp);
363 :
364 17432 : if (IsA(node, Var))
365 : {
366 17342 : Var *var = (Var *) node;
367 17342 : RelOptInfo *rel = find_base_rel(root, var->varno);
368 17342 : int attno = var->varattno;
369 :
370 17342 : if (bms_is_subset(where_needed, rel->relids))
371 844 : continue;
372 : Assert(attno >= rel->min_attr && attno <= rel->max_attr);
373 16498 : attno -= rel->min_attr;
374 16498 : rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
375 : where_needed);
376 : }
377 90 : else if (IsA(node, PlaceHolderVar))
378 : {
379 90 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
380 90 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
381 :
382 90 : phinfo->ph_needed = bms_add_members(phinfo->ph_needed,
383 : where_needed);
384 : }
385 : else
386 0 : elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
387 : }
388 13296 : }
389 :
390 : /*****************************************************************************
391 : *
392 : * GROUP BY
393 : *
394 : *****************************************************************************/
395 :
396 : /*
397 : * remove_useless_groupby_columns
398 : * Remove any columns in the GROUP BY clause that are redundant due to
399 : * being functionally dependent on other GROUP BY columns.
400 : *
401 : * Since some other DBMSes do not allow references to ungrouped columns, it's
402 : * not unusual to find all columns listed in GROUP BY even though listing the
403 : * primary-key columns, or columns of a unique constraint would be sufficient.
404 : * Deleting such excess columns avoids redundant sorting or hashing work, so
405 : * it's worth doing.
406 : *
407 : * Relcache invalidations will ensure that cached plans become invalidated
408 : * when the underlying supporting indexes are dropped or if a column's NOT
409 : * NULL attribute is removed.
410 : */
411 : void
412 328968 : remove_useless_groupby_columns(PlannerInfo *root)
413 : {
414 328968 : Query *parse = root->parse;
415 : Bitmapset **groupbyattnos;
416 : Bitmapset **surplusvars;
417 328968 : bool tryremove = false;
418 : ListCell *lc;
419 : int relid;
420 :
421 : /* No chance to do anything if there are less than two GROUP BY items */
422 328968 : if (list_length(root->processed_groupClause) < 2)
423 326986 : return;
424 :
425 : /* Don't fiddle with the GROUP BY clause if the query has grouping sets */
426 1982 : if (parse->groupingSets)
427 662 : return;
428 :
429 : /*
430 : * Scan the GROUP BY clause to find GROUP BY items that are simple Vars.
431 : * Fill groupbyattnos[k] with a bitmapset of the column attnos of RTE k
432 : * that are GROUP BY items.
433 : */
434 1320 : groupbyattnos = (Bitmapset **) palloc0(sizeof(Bitmapset *) *
435 1320 : (list_length(parse->rtable) + 1));
436 4736 : foreach(lc, root->processed_groupClause)
437 : {
438 3416 : SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
439 3416 : TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
440 3416 : Var *var = (Var *) tle->expr;
441 :
442 : /*
443 : * Ignore non-Vars and Vars from other query levels.
444 : *
445 : * XXX in principle, stable expressions containing Vars could also be
446 : * removed, if all the Vars are functionally dependent on other GROUP
447 : * BY items. But it's not clear that such cases occur often enough to
448 : * be worth troubling over.
449 : */
450 3416 : if (!IsA(var, Var) ||
451 2606 : var->varlevelsup > 0)
452 810 : continue;
453 :
454 : /* OK, remember we have this Var */
455 2606 : relid = var->varno;
456 : Assert(relid <= list_length(parse->rtable));
457 :
458 : /*
459 : * If this isn't the first column for this relation then we now have
460 : * multiple columns. That means there might be some that can be
461 : * removed.
462 : */
463 2606 : tryremove |= !bms_is_empty(groupbyattnos[relid]);
464 2606 : groupbyattnos[relid] = bms_add_member(groupbyattnos[relid],
465 2606 : var->varattno - FirstLowInvalidHeapAttributeNumber);
466 : }
467 :
468 : /*
469 : * No Vars or didn't find multiple Vars for any relation in the GROUP BY?
470 : * If so, nothing can be removed, so don't waste more effort trying.
471 : */
472 1320 : if (!tryremove)
473 452 : return;
474 :
475 : /*
476 : * Consider each relation and see if it is possible to remove some of its
477 : * Vars from GROUP BY. For simplicity and speed, we do the actual removal
478 : * in a separate pass. Here, we just fill surplusvars[k] with a bitmapset
479 : * of the column attnos of RTE k that are removable GROUP BY items.
480 : */
481 868 : surplusvars = NULL; /* don't allocate array unless required */
482 868 : relid = 0;
483 3342 : foreach(lc, parse->rtable)
484 : {
485 2474 : RangeTblEntry *rte = lfirst_node(RangeTblEntry, lc);
486 : RelOptInfo *rel;
487 : Bitmapset *relattnos;
488 2474 : Bitmapset *best_keycolumns = NULL;
489 2474 : int32 best_nkeycolumns = PG_INT32_MAX;
490 :
491 2474 : relid++;
492 :
493 : /* Only plain relations could have primary-key constraints */
494 2474 : if (rte->rtekind != RTE_RELATION)
495 1264 : continue;
496 :
497 : /*
498 : * We must skip inheritance parent tables as some of the child rels
499 : * may cause duplicate rows. This cannot happen with partitioned
500 : * tables, however.
501 : */
502 1210 : if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
503 18 : continue;
504 :
505 : /* Nothing to do unless this rel has multiple Vars in GROUP BY */
506 1192 : relattnos = groupbyattnos[relid];
507 1192 : if (bms_membership(relattnos) != BMS_MULTIPLE)
508 360 : continue;
509 :
510 832 : rel = root->simple_rel_array[relid];
511 :
512 : /*
513 : * Now check each index for this relation to see if there are any with
514 : * columns which are a proper subset of the grouping columns for this
515 : * relation.
516 : */
517 2380 : foreach_node(IndexOptInfo, index, rel->indexlist)
518 : {
519 : Bitmapset *ind_attnos;
520 : bool nulls_check_ok;
521 :
522 : /*
523 : * Skip any non-unique and deferrable indexes. Predicate indexes
524 : * have not been checked yet, so we must skip those too as the
525 : * predOK check that's done later might fail.
526 : */
527 716 : if (!index->unique || !index->immediate || index->indpred != NIL)
528 300 : continue;
529 :
530 : /* For simplicity, we currently don't support expression indexes */
531 416 : if (index->indexprs != NIL)
532 0 : continue;
533 :
534 416 : ind_attnos = NULL;
535 416 : nulls_check_ok = true;
536 1054 : for (int i = 0; i < index->nkeycolumns; i++)
537 : {
538 : /*
539 : * We must insist that the index columns are all defined NOT
540 : * NULL otherwise duplicate NULLs could exist. However, we
541 : * can relax this check when the index is defined with NULLS
542 : * NOT DISTINCT as there can only be 1 NULL row, therefore
543 : * functional dependency on the unique columns is maintained,
544 : * despite the NULL.
545 : */
546 644 : if (!index->nullsnotdistinct &&
547 638 : !bms_is_member(index->indexkeys[i],
548 638 : rel->notnullattnums))
549 : {
550 6 : nulls_check_ok = false;
551 6 : break;
552 : }
553 :
554 : ind_attnos =
555 638 : bms_add_member(ind_attnos,
556 638 : index->indexkeys[i] -
557 : FirstLowInvalidHeapAttributeNumber);
558 : }
559 :
560 416 : if (!nulls_check_ok)
561 6 : continue;
562 :
563 : /*
564 : * Skip any indexes where the indexed columns aren't a proper
565 : * subset of the GROUP BY.
566 : */
567 410 : if (bms_subset_compare(ind_attnos, relattnos) != BMS_SUBSET1)
568 180 : continue;
569 :
570 : /*
571 : * Record the attribute numbers from the index with the fewest
572 : * columns. This allows the largest number of columns to be
573 : * removed from the GROUP BY clause. In the future, we may wish
574 : * to consider using the narrowest set of columns and looking at
575 : * pg_statistic.stawidth as it might be better to use an index
576 : * with, say two INT4s, rather than, say, one long varlena column.
577 : */
578 230 : if (index->nkeycolumns < best_nkeycolumns)
579 : {
580 212 : best_keycolumns = ind_attnos;
581 212 : best_nkeycolumns = index->nkeycolumns;
582 : }
583 : }
584 :
585 : /* Did we find a suitable index? */
586 832 : if (!bms_is_empty(best_keycolumns))
587 : {
588 : /*
589 : * To easily remember whether we've found anything to do, we don't
590 : * allocate the surplusvars[] array until we find something.
591 : */
592 212 : if (surplusvars == NULL)
593 206 : surplusvars = (Bitmapset **) palloc0(sizeof(Bitmapset *) *
594 206 : (list_length(parse->rtable) + 1));
595 :
596 : /* Remember the attnos of the removable columns */
597 212 : surplusvars[relid] = bms_difference(relattnos, best_keycolumns);
598 : }
599 : }
600 :
601 : /*
602 : * If we found any surplus Vars, build a new GROUP BY clause without them.
603 : * (Note: this may leave some TLEs with unreferenced ressortgroupref
604 : * markings, but that's harmless.)
605 : */
606 868 : if (surplusvars != NULL)
607 : {
608 206 : List *new_groupby = NIL;
609 :
610 858 : foreach(lc, root->processed_groupClause)
611 : {
612 652 : SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
613 652 : TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
614 652 : Var *var = (Var *) tle->expr;
615 :
616 : /*
617 : * New list must include non-Vars, outer Vars, and anything not
618 : * marked as surplus.
619 : */
620 652 : if (!IsA(var, Var) ||
621 652 : var->varlevelsup > 0 ||
622 652 : !bms_is_member(var->varattno - FirstLowInvalidHeapAttributeNumber,
623 652 : surplusvars[var->varno]))
624 398 : new_groupby = lappend(new_groupby, sgc);
625 : }
626 :
627 206 : root->processed_groupClause = new_groupby;
628 : }
629 : }
630 :
631 : /*****************************************************************************
632 : *
633 : * LATERAL REFERENCES
634 : *
635 : *****************************************************************************/
636 :
637 : /*
638 : * find_lateral_references
639 : * For each LATERAL subquery, extract all its references to Vars and
640 : * PlaceHolderVars of the current query level, and make sure those values
641 : * will be available for evaluation of the subquery.
642 : *
643 : * While later planning steps ensure that the Var/PHV source rels are on the
644 : * outside of nestloops relative to the LATERAL subquery, we also need to
645 : * ensure that the Vars/PHVs propagate up to the nestloop join level; this
646 : * means setting suitable where_needed values for them.
647 : *
648 : * Note that this only deals with lateral references in unflattened LATERAL
649 : * subqueries. When we flatten a LATERAL subquery, its lateral references
650 : * become plain Vars in the parent query, but they may have to be wrapped in
651 : * PlaceHolderVars if they need to be forced NULL by outer joins that don't
652 : * also null the LATERAL subquery. That's all handled elsewhere.
653 : *
654 : * This has to run before deconstruct_jointree, since it might result in
655 : * creation of PlaceHolderInfos.
656 : */
657 : void
658 328968 : find_lateral_references(PlannerInfo *root)
659 : {
660 : Index rti;
661 :
662 : /* We need do nothing if the query contains no LATERAL RTEs */
663 328968 : if (!root->hasLateralRTEs)
664 318928 : return;
665 :
666 : /*
667 : * Examine all baserels (the rel array has been set up by now).
668 : */
669 37496 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
670 : {
671 27456 : RelOptInfo *brel = root->simple_rel_array[rti];
672 :
673 : /* there may be empty slots corresponding to non-baserel RTEs */
674 27456 : if (brel == NULL)
675 5586 : continue;
676 :
677 : Assert(brel->relid == rti); /* sanity check on array */
678 :
679 : /*
680 : * This bit is less obvious than it might look. We ignore appendrel
681 : * otherrels and consider only their parent baserels. In a case where
682 : * a LATERAL-containing UNION ALL subquery was pulled up, it is the
683 : * otherrel that is actually going to be in the plan. However, we
684 : * want to mark all its lateral references as needed by the parent,
685 : * because it is the parent's relid that will be used for join
686 : * planning purposes. And the parent's RTE will contain all the
687 : * lateral references we need to know, since the pulled-up member is
688 : * nothing but a copy of parts of the original RTE's subquery. We
689 : * could visit the parent's children instead and transform their
690 : * references back to the parent's relid, but it would be much more
691 : * complicated for no real gain. (Important here is that the child
692 : * members have not yet received any processing beyond being pulled
693 : * up.) Similarly, in appendrels created by inheritance expansion,
694 : * it's sufficient to look at the parent relation.
695 : */
696 :
697 : /* ignore RTEs that are "other rels" */
698 21870 : if (brel->reloptkind != RELOPT_BASEREL)
699 0 : continue;
700 :
701 21870 : extract_lateral_references(root, brel, rti);
702 : }
703 : }
704 :
705 : static void
706 21870 : extract_lateral_references(PlannerInfo *root, RelOptInfo *brel, Index rtindex)
707 : {
708 21870 : RangeTblEntry *rte = root->simple_rte_array[rtindex];
709 : List *vars;
710 : List *newvars;
711 : Relids where_needed;
712 : ListCell *lc;
713 :
714 : /* No cross-references are possible if it's not LATERAL */
715 21870 : if (!rte->lateral)
716 12536 : return;
717 :
718 : /* Fetch the appropriate variables */
719 9334 : if (rte->rtekind == RTE_RELATION)
720 36 : vars = pull_vars_of_level((Node *) rte->tablesample, 0);
721 9298 : else if (rte->rtekind == RTE_SUBQUERY)
722 584 : vars = pull_vars_of_level((Node *) rte->subquery, 1);
723 8714 : else if (rte->rtekind == RTE_FUNCTION)
724 8408 : vars = pull_vars_of_level((Node *) rte->functions, 0);
725 306 : else if (rte->rtekind == RTE_TABLEFUNC)
726 234 : vars = pull_vars_of_level((Node *) rte->tablefunc, 0);
727 72 : else if (rte->rtekind == RTE_VALUES)
728 72 : vars = pull_vars_of_level((Node *) rte->values_lists, 0);
729 : else
730 : {
731 : Assert(false);
732 0 : return; /* keep compiler quiet */
733 : }
734 :
735 9334 : if (vars == NIL)
736 94 : return; /* nothing to do */
737 :
738 : /* Copy each Var (or PlaceHolderVar) and adjust it to match our level */
739 9240 : newvars = NIL;
740 19370 : foreach(lc, vars)
741 : {
742 10130 : Node *node = (Node *) lfirst(lc);
743 :
744 10130 : node = copyObject(node);
745 10130 : if (IsA(node, Var))
746 : {
747 10022 : Var *var = (Var *) node;
748 :
749 : /* Adjustment is easy since it's just one node */
750 10022 : var->varlevelsup = 0;
751 : }
752 108 : else if (IsA(node, PlaceHolderVar))
753 : {
754 108 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
755 108 : int levelsup = phv->phlevelsup;
756 :
757 : /* Have to work harder to adjust the contained expression too */
758 108 : if (levelsup != 0)
759 72 : IncrementVarSublevelsUp(node, -levelsup, 0);
760 :
761 : /*
762 : * If we pulled the PHV out of a subquery RTE, its expression
763 : * needs to be preprocessed. subquery_planner() already did this
764 : * for level-zero PHVs in function and values RTEs, though.
765 : */
766 108 : if (levelsup > 0)
767 72 : phv->phexpr = preprocess_phv_expression(root, phv->phexpr);
768 : }
769 : else
770 : Assert(false);
771 10130 : newvars = lappend(newvars, node);
772 : }
773 :
774 9240 : list_free(vars);
775 :
776 : /*
777 : * We mark the Vars as being "needed" at the LATERAL RTE. This is a bit
778 : * of a cheat: a more formal approach would be to mark each one as needed
779 : * at the join of the LATERAL RTE with its source RTE. But it will work,
780 : * and it's much less tedious than computing a separate where_needed for
781 : * each Var.
782 : */
783 9240 : where_needed = bms_make_singleton(rtindex);
784 :
785 : /*
786 : * Push Vars into their source relations' targetlists, and PHVs into
787 : * root->placeholder_list.
788 : */
789 9240 : add_vars_to_targetlist(root, newvars, where_needed);
790 :
791 : /*
792 : * Remember the lateral references for rebuild_lateral_attr_needed and
793 : * create_lateral_join_info.
794 : */
795 9240 : brel->lateral_vars = newvars;
796 : }
797 :
798 : /*
799 : * rebuild_lateral_attr_needed
800 : * Put back attr_needed bits for Vars/PHVs needed for lateral references.
801 : *
802 : * This is used to rebuild attr_needed/ph_needed sets after removal of a
803 : * useless outer join. It should match what find_lateral_references did,
804 : * except that we call add_vars_to_attr_needed not add_vars_to_targetlist.
805 : */
806 : void
807 11550 : rebuild_lateral_attr_needed(PlannerInfo *root)
808 : {
809 : Index rti;
810 :
811 : /* We need do nothing if the query contains no LATERAL RTEs */
812 11550 : if (!root->hasLateralRTEs)
813 11202 : return;
814 :
815 : /* Examine the same baserels that find_lateral_references did */
816 3272 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
817 : {
818 2924 : RelOptInfo *brel = root->simple_rel_array[rti];
819 : Relids where_needed;
820 :
821 2924 : if (brel == NULL)
822 2068 : continue;
823 856 : if (brel->reloptkind != RELOPT_BASEREL)
824 0 : continue;
825 :
826 : /*
827 : * We don't need to repeat all of extract_lateral_references, since it
828 : * kindly saved the extracted Vars/PHVs in lateral_vars.
829 : */
830 856 : if (brel->lateral_vars == NIL)
831 734 : continue;
832 :
833 122 : where_needed = bms_make_singleton(rti);
834 :
835 122 : add_vars_to_attr_needed(root, brel->lateral_vars, where_needed);
836 : }
837 : }
838 :
839 : /*
840 : * create_lateral_join_info
841 : * Fill in the per-base-relation direct_lateral_relids, lateral_relids
842 : * and lateral_referencers sets.
843 : */
844 : void
845 328968 : create_lateral_join_info(PlannerInfo *root)
846 : {
847 328968 : bool found_laterals = false;
848 : Index rti;
849 : ListCell *lc;
850 :
851 : /* We need do nothing if the query contains no LATERAL RTEs */
852 328968 : if (!root->hasLateralRTEs)
853 318928 : return;
854 :
855 : /* We'll need to have the ph_eval_at values for PlaceHolderVars */
856 : Assert(root->placeholdersFrozen);
857 :
858 : /*
859 : * Examine all baserels (the rel array has been set up by now).
860 : */
861 37496 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
862 : {
863 27456 : RelOptInfo *brel = root->simple_rel_array[rti];
864 : Relids lateral_relids;
865 :
866 : /* there may be empty slots corresponding to non-baserel RTEs */
867 27456 : if (brel == NULL)
868 5934 : continue;
869 :
870 : Assert(brel->relid == rti); /* sanity check on array */
871 :
872 : /* ignore RTEs that are "other rels" */
873 21522 : if (brel->reloptkind != RELOPT_BASEREL)
874 0 : continue;
875 :
876 21522 : lateral_relids = NULL;
877 :
878 : /* consider each laterally-referenced Var or PHV */
879 31628 : foreach(lc, brel->lateral_vars)
880 : {
881 10106 : Node *node = (Node *) lfirst(lc);
882 :
883 10106 : if (IsA(node, Var))
884 : {
885 9998 : Var *var = (Var *) node;
886 :
887 9998 : found_laterals = true;
888 9998 : lateral_relids = bms_add_member(lateral_relids,
889 : var->varno);
890 : }
891 108 : else if (IsA(node, PlaceHolderVar))
892 : {
893 108 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
894 108 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
895 :
896 108 : found_laterals = true;
897 108 : lateral_relids = bms_add_members(lateral_relids,
898 108 : phinfo->ph_eval_at);
899 : }
900 : else
901 : Assert(false);
902 : }
903 :
904 : /* We now have all the simple lateral refs from this rel */
905 21522 : brel->direct_lateral_relids = lateral_relids;
906 21522 : brel->lateral_relids = bms_copy(lateral_relids);
907 : }
908 :
909 : /*
910 : * Now check for lateral references within PlaceHolderVars, and mark their
911 : * eval_at rels as having lateral references to the source rels.
912 : *
913 : * For a PHV that is due to be evaluated at a baserel, mark its source(s)
914 : * as direct lateral dependencies of the baserel (adding onto the ones
915 : * recorded above). If it's due to be evaluated at a join, mark its
916 : * source(s) as indirect lateral dependencies of each baserel in the join,
917 : * ie put them into lateral_relids but not direct_lateral_relids. This is
918 : * appropriate because we can't put any such baserel on the outside of a
919 : * join to one of the PHV's lateral dependencies, but on the other hand we
920 : * also can't yet join it directly to the dependency.
921 : */
922 10588 : foreach(lc, root->placeholder_list)
923 : {
924 548 : PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
925 548 : Relids eval_at = phinfo->ph_eval_at;
926 : Relids lateral_refs;
927 : int varno;
928 :
929 548 : if (phinfo->ph_lateral == NULL)
930 286 : continue; /* PHV is uninteresting if no lateral refs */
931 :
932 262 : found_laterals = true;
933 :
934 : /*
935 : * Include only baserels not outer joins in the evaluation sites'
936 : * lateral relids. This avoids problems when outer join order gets
937 : * rearranged, and it should still ensure that the lateral values are
938 : * available when needed.
939 : */
940 262 : lateral_refs = bms_intersect(phinfo->ph_lateral, root->all_baserels);
941 : Assert(!bms_is_empty(lateral_refs));
942 :
943 262 : if (bms_get_singleton_member(eval_at, &varno))
944 : {
945 : /* Evaluation site is a baserel */
946 196 : RelOptInfo *brel = find_base_rel(root, varno);
947 :
948 196 : brel->direct_lateral_relids =
949 196 : bms_add_members(brel->direct_lateral_relids,
950 : lateral_refs);
951 196 : brel->lateral_relids =
952 196 : bms_add_members(brel->lateral_relids,
953 : lateral_refs);
954 : }
955 : else
956 : {
957 : /* Evaluation site is a join */
958 66 : varno = -1;
959 198 : while ((varno = bms_next_member(eval_at, varno)) >= 0)
960 : {
961 132 : RelOptInfo *brel = find_base_rel_ignore_join(root, varno);
962 :
963 132 : if (brel == NULL)
964 0 : continue; /* ignore outer joins in eval_at */
965 132 : brel->lateral_relids = bms_add_members(brel->lateral_relids,
966 : lateral_refs);
967 : }
968 : }
969 : }
970 :
971 : /*
972 : * If we found no actual lateral references, we're done; but reset the
973 : * hasLateralRTEs flag to avoid useless work later.
974 : */
975 10040 : if (!found_laterals)
976 : {
977 646 : root->hasLateralRTEs = false;
978 646 : return;
979 : }
980 :
981 : /*
982 : * Calculate the transitive closure of the lateral_relids sets, so that
983 : * they describe both direct and indirect lateral references. If relation
984 : * X references Y laterally, and Y references Z laterally, then we will
985 : * have to scan X on the inside of a nestloop with Z, so for all intents
986 : * and purposes X is laterally dependent on Z too.
987 : *
988 : * This code is essentially Warshall's algorithm for transitive closure.
989 : * The outer loop considers each baserel, and propagates its lateral
990 : * dependencies to those baserels that have a lateral dependency on it.
991 : */
992 32928 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
993 : {
994 23534 : RelOptInfo *brel = root->simple_rel_array[rti];
995 : Relids outer_lateral_relids;
996 : Index rti2;
997 :
998 23534 : if (brel == NULL || brel->reloptkind != RELOPT_BASEREL)
999 3384 : continue;
1000 :
1001 : /* need not consider baserel further if it has no lateral refs */
1002 20150 : outer_lateral_relids = brel->lateral_relids;
1003 20150 : if (outer_lateral_relids == NULL)
1004 10606 : continue;
1005 :
1006 : /* else scan all baserels */
1007 34008 : for (rti2 = 1; rti2 < root->simple_rel_array_size; rti2++)
1008 : {
1009 24464 : RelOptInfo *brel2 = root->simple_rel_array[rti2];
1010 :
1011 24464 : if (brel2 == NULL || brel2->reloptkind != RELOPT_BASEREL)
1012 3768 : continue;
1013 :
1014 : /* if brel2 has lateral ref to brel, propagate brel's refs */
1015 20696 : if (bms_is_member(rti, brel2->lateral_relids))
1016 66 : brel2->lateral_relids = bms_add_members(brel2->lateral_relids,
1017 : outer_lateral_relids);
1018 : }
1019 : }
1020 :
1021 : /*
1022 : * Now that we've identified all lateral references, mark each baserel
1023 : * with the set of relids of rels that reference it laterally (possibly
1024 : * indirectly) --- that is, the inverse mapping of lateral_relids.
1025 : */
1026 32928 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1027 : {
1028 23534 : RelOptInfo *brel = root->simple_rel_array[rti];
1029 : Relids lateral_relids;
1030 : int rti2;
1031 :
1032 23534 : if (brel == NULL || brel->reloptkind != RELOPT_BASEREL)
1033 3384 : continue;
1034 :
1035 : /* Nothing to do at rels with no lateral refs */
1036 20150 : lateral_relids = brel->lateral_relids;
1037 20150 : if (bms_is_empty(lateral_relids))
1038 10606 : continue;
1039 :
1040 : /* No rel should have a lateral dependency on itself */
1041 : Assert(!bms_is_member(rti, lateral_relids));
1042 :
1043 : /* Mark this rel's referencees */
1044 9544 : rti2 = -1;
1045 19316 : while ((rti2 = bms_next_member(lateral_relids, rti2)) >= 0)
1046 : {
1047 9772 : RelOptInfo *brel2 = root->simple_rel_array[rti2];
1048 :
1049 9772 : if (brel2 == NULL)
1050 12 : continue; /* must be an OJ */
1051 :
1052 : Assert(brel2->reloptkind == RELOPT_BASEREL);
1053 9760 : brel2->lateral_referencers =
1054 9760 : bms_add_member(brel2->lateral_referencers, rti);
1055 : }
1056 : }
1057 : }
1058 :
1059 :
1060 : /*****************************************************************************
1061 : *
1062 : * JOIN TREE PROCESSING
1063 : *
1064 : *****************************************************************************/
1065 :
1066 : /*
1067 : * deconstruct_jointree
1068 : * Recursively scan the query's join tree for WHERE and JOIN/ON qual
1069 : * clauses, and add these to the appropriate restrictinfo and joininfo
1070 : * lists belonging to base RelOptInfos. Also, add SpecialJoinInfo nodes
1071 : * to root->join_info_list for any outer joins appearing in the query tree.
1072 : * Return a "joinlist" data structure showing the join order decisions
1073 : * that need to be made by make_one_rel().
1074 : *
1075 : * The "joinlist" result is a list of items that are either RangeTblRef
1076 : * jointree nodes or sub-joinlists. All the items at the same level of
1077 : * joinlist must be joined in an order to be determined by make_one_rel()
1078 : * (note that legal orders may be constrained by SpecialJoinInfo nodes).
1079 : * A sub-joinlist represents a subproblem to be planned separately. Currently
1080 : * sub-joinlists arise only from FULL OUTER JOIN or when collapsing of
1081 : * subproblems is stopped by join_collapse_limit or from_collapse_limit.
1082 : */
1083 : List *
1084 328968 : deconstruct_jointree(PlannerInfo *root)
1085 : {
1086 : List *result;
1087 : JoinDomain *top_jdomain;
1088 328968 : List *item_list = NIL;
1089 : ListCell *lc;
1090 :
1091 : /*
1092 : * After this point, no more PlaceHolderInfos may be made, because
1093 : * make_outerjoininfo requires all active placeholders to be present in
1094 : * root->placeholder_list while we crawl up the join tree.
1095 : */
1096 328968 : root->placeholdersFrozen = true;
1097 :
1098 : /* Fetch the already-created top-level join domain for the query */
1099 328968 : top_jdomain = linitial_node(JoinDomain, root->join_domains);
1100 328968 : top_jdomain->jd_relids = NULL; /* filled during deconstruct_recurse */
1101 :
1102 : /* Start recursion at top of jointree */
1103 : Assert(root->parse->jointree != NULL &&
1104 : IsA(root->parse->jointree, FromExpr));
1105 :
1106 : /* These are filled as we scan the jointree */
1107 328968 : root->all_baserels = NULL;
1108 328968 : root->outer_join_rels = NULL;
1109 :
1110 : /* Perform the initial scan of the jointree */
1111 328968 : result = deconstruct_recurse(root, (Node *) root->parse->jointree,
1112 : top_jdomain, NULL,
1113 : &item_list);
1114 :
1115 : /* Now we can form the value of all_query_rels, too */
1116 328968 : root->all_query_rels = bms_union(root->all_baserels, root->outer_join_rels);
1117 :
1118 : /* ... which should match what we computed for the top join domain */
1119 : Assert(bms_equal(root->all_query_rels, top_jdomain->jd_relids));
1120 :
1121 : /* Now scan all the jointree nodes again, and distribute quals */
1122 1240364 : foreach(lc, item_list)
1123 : {
1124 911396 : JoinTreeItem *jtitem = (JoinTreeItem *) lfirst(lc);
1125 :
1126 911396 : deconstruct_distribute(root, jtitem);
1127 : }
1128 :
1129 : /*
1130 : * If there were any special joins then we may have some postponed LEFT
1131 : * JOIN clauses to deal with.
1132 : */
1133 328968 : if (root->join_info_list)
1134 : {
1135 264648 : foreach(lc, item_list)
1136 : {
1137 224484 : JoinTreeItem *jtitem = (JoinTreeItem *) lfirst(lc);
1138 :
1139 224484 : if (jtitem->oj_joinclauses != NIL)
1140 43252 : deconstruct_distribute_oj_quals(root, item_list, jtitem);
1141 : }
1142 : }
1143 :
1144 : /* Don't need the JoinTreeItems any more */
1145 328968 : list_free_deep(item_list);
1146 :
1147 328968 : return result;
1148 : }
1149 :
1150 : /*
1151 : * deconstruct_recurse
1152 : * One recursion level of deconstruct_jointree's initial jointree scan.
1153 : *
1154 : * jtnode is the jointree node to examine, and parent_domain is the
1155 : * enclosing join domain. (We must add all base+OJ relids appearing
1156 : * here or below to parent_domain.) parent_jtitem is the JoinTreeItem
1157 : * for the parent jointree node, or NULL at the top of the recursion.
1158 : *
1159 : * item_list is an in/out parameter: we add a JoinTreeItem struct to
1160 : * that list for each jointree node, in depth-first traversal order.
1161 : * (Hence, after each call, the last list item corresponds to its jtnode.)
1162 : *
1163 : * Return value is the appropriate joinlist for this jointree node.
1164 : */
1165 : static List *
1166 911396 : deconstruct_recurse(PlannerInfo *root, Node *jtnode,
1167 : JoinDomain *parent_domain,
1168 : JoinTreeItem *parent_jtitem,
1169 : List **item_list)
1170 : {
1171 : List *joinlist;
1172 : JoinTreeItem *jtitem;
1173 :
1174 : Assert(jtnode != NULL);
1175 :
1176 : /* Make the new JoinTreeItem, but don't add it to item_list yet */
1177 911396 : jtitem = palloc0_object(JoinTreeItem);
1178 911396 : jtitem->jtnode = jtnode;
1179 911396 : jtitem->jti_parent = parent_jtitem;
1180 :
1181 911396 : if (IsA(jtnode, RangeTblRef))
1182 : {
1183 474706 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1184 :
1185 : /* Fill all_baserels as we encounter baserel jointree nodes */
1186 474706 : root->all_baserels = bms_add_member(root->all_baserels, varno);
1187 : /* This node belongs to parent_domain */
1188 474706 : jtitem->jdomain = parent_domain;
1189 474706 : parent_domain->jd_relids = bms_add_member(parent_domain->jd_relids,
1190 : varno);
1191 : /* qualscope is just the one RTE */
1192 474706 : jtitem->qualscope = bms_make_singleton(varno);
1193 : /* A single baserel does not create an inner join */
1194 474706 : jtitem->inner_join_rels = NULL;
1195 474706 : joinlist = list_make1(jtnode);
1196 : }
1197 436690 : else if (IsA(jtnode, FromExpr))
1198 : {
1199 340928 : FromExpr *f = (FromExpr *) jtnode;
1200 : int remaining;
1201 : ListCell *l;
1202 :
1203 : /* This node belongs to parent_domain, as do its children */
1204 340928 : jtitem->jdomain = parent_domain;
1205 :
1206 : /*
1207 : * Recurse to handle child nodes, and compute output joinlist. We
1208 : * collapse subproblems into a single joinlist whenever the resulting
1209 : * joinlist wouldn't exceed from_collapse_limit members. Also, always
1210 : * collapse one-element subproblems, since that won't lengthen the
1211 : * joinlist anyway.
1212 : */
1213 340928 : jtitem->qualscope = NULL;
1214 340928 : jtitem->inner_join_rels = NULL;
1215 340928 : joinlist = NIL;
1216 340928 : remaining = list_length(f->fromlist);
1217 731832 : foreach(l, f->fromlist)
1218 : {
1219 : JoinTreeItem *sub_item;
1220 : List *sub_joinlist;
1221 : int sub_members;
1222 :
1223 390904 : sub_joinlist = deconstruct_recurse(root, lfirst(l),
1224 : parent_domain,
1225 : jtitem,
1226 : item_list);
1227 390904 : sub_item = (JoinTreeItem *) llast(*item_list);
1228 781808 : jtitem->qualscope = bms_add_members(jtitem->qualscope,
1229 390904 : sub_item->qualscope);
1230 390904 : jtitem->inner_join_rels = sub_item->inner_join_rels;
1231 390904 : sub_members = list_length(sub_joinlist);
1232 390904 : remaining--;
1233 390904 : if (sub_members <= 1 ||
1234 60984 : list_length(joinlist) + sub_members + remaining <= from_collapse_limit)
1235 390904 : joinlist = list_concat(joinlist, sub_joinlist);
1236 : else
1237 0 : joinlist = lappend(joinlist, sub_joinlist);
1238 : }
1239 :
1240 : /*
1241 : * A FROM with more than one list element is an inner join subsuming
1242 : * all below it, so we should report inner_join_rels = qualscope. If
1243 : * there was exactly one element, we should (and already did) report
1244 : * whatever its inner_join_rels were. If there were no elements (is
1245 : * that still possible?) the initialization before the loop fixed it.
1246 : */
1247 340928 : if (list_length(f->fromlist) > 1)
1248 45484 : jtitem->inner_join_rels = jtitem->qualscope;
1249 : }
1250 95762 : else if (IsA(jtnode, JoinExpr))
1251 : {
1252 95762 : JoinExpr *j = (JoinExpr *) jtnode;
1253 : JoinDomain *child_domain,
1254 : *fj_domain;
1255 : JoinTreeItem *left_item,
1256 : *right_item;
1257 : List *leftjoinlist,
1258 : *rightjoinlist;
1259 :
1260 95762 : switch (j->jointype)
1261 : {
1262 41084 : case JOIN_INNER:
1263 : /* This node belongs to parent_domain, as do its children */
1264 41084 : jtitem->jdomain = parent_domain;
1265 : /* Recurse */
1266 41084 : leftjoinlist = deconstruct_recurse(root, j->larg,
1267 : parent_domain,
1268 : jtitem,
1269 : item_list);
1270 41084 : left_item = (JoinTreeItem *) llast(*item_list);
1271 41084 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1272 : parent_domain,
1273 : jtitem,
1274 : item_list);
1275 41084 : right_item = (JoinTreeItem *) llast(*item_list);
1276 : /* Compute qualscope etc */
1277 82168 : jtitem->qualscope = bms_union(left_item->qualscope,
1278 41084 : right_item->qualscope);
1279 41084 : jtitem->inner_join_rels = jtitem->qualscope;
1280 41084 : jtitem->left_rels = left_item->qualscope;
1281 41084 : jtitem->right_rels = right_item->qualscope;
1282 : /* Inner join adds no restrictions for quals */
1283 41084 : jtitem->nonnullable_rels = NULL;
1284 41084 : break;
1285 48838 : case JOIN_LEFT:
1286 : case JOIN_ANTI:
1287 : /* Make new join domain for my quals and the RHS */
1288 48838 : child_domain = makeNode(JoinDomain);
1289 48838 : child_domain->jd_relids = NULL; /* filled by recursion */
1290 48838 : root->join_domains = lappend(root->join_domains, child_domain);
1291 48838 : jtitem->jdomain = child_domain;
1292 : /* Recurse */
1293 48838 : leftjoinlist = deconstruct_recurse(root, j->larg,
1294 : parent_domain,
1295 : jtitem,
1296 : item_list);
1297 48838 : left_item = (JoinTreeItem *) llast(*item_list);
1298 48838 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1299 : child_domain,
1300 : jtitem,
1301 : item_list);
1302 48838 : right_item = (JoinTreeItem *) llast(*item_list);
1303 : /* Compute join domain contents, qualscope etc */
1304 48838 : parent_domain->jd_relids =
1305 48838 : bms_add_members(parent_domain->jd_relids,
1306 48838 : child_domain->jd_relids);
1307 97676 : jtitem->qualscope = bms_union(left_item->qualscope,
1308 48838 : right_item->qualscope);
1309 : /* caution: ANTI join derived from SEMI will lack rtindex */
1310 48838 : if (j->rtindex != 0)
1311 : {
1312 45918 : parent_domain->jd_relids =
1313 45918 : bms_add_member(parent_domain->jd_relids,
1314 : j->rtindex);
1315 45918 : jtitem->qualscope = bms_add_member(jtitem->qualscope,
1316 : j->rtindex);
1317 45918 : root->outer_join_rels = bms_add_member(root->outer_join_rels,
1318 : j->rtindex);
1319 45918 : mark_rels_nulled_by_join(root, j->rtindex,
1320 : right_item->qualscope);
1321 : }
1322 97676 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1323 48838 : right_item->inner_join_rels);
1324 48838 : jtitem->left_rels = left_item->qualscope;
1325 48838 : jtitem->right_rels = right_item->qualscope;
1326 48838 : jtitem->nonnullable_rels = left_item->qualscope;
1327 48838 : break;
1328 4812 : case JOIN_SEMI:
1329 : /* This node belongs to parent_domain, as do its children */
1330 4812 : jtitem->jdomain = parent_domain;
1331 : /* Recurse */
1332 4812 : leftjoinlist = deconstruct_recurse(root, j->larg,
1333 : parent_domain,
1334 : jtitem,
1335 : item_list);
1336 4812 : left_item = (JoinTreeItem *) llast(*item_list);
1337 4812 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1338 : parent_domain,
1339 : jtitem,
1340 : item_list);
1341 4812 : right_item = (JoinTreeItem *) llast(*item_list);
1342 : /* Compute qualscope etc */
1343 9624 : jtitem->qualscope = bms_union(left_item->qualscope,
1344 4812 : right_item->qualscope);
1345 : /* SEMI join never has rtindex, so don't add to anything */
1346 : Assert(j->rtindex == 0);
1347 9624 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1348 4812 : right_item->inner_join_rels);
1349 4812 : jtitem->left_rels = left_item->qualscope;
1350 4812 : jtitem->right_rels = right_item->qualscope;
1351 : /* Semi join adds no restrictions for quals */
1352 4812 : jtitem->nonnullable_rels = NULL;
1353 4812 : break;
1354 1028 : case JOIN_FULL:
1355 : /* The FULL JOIN's quals need their very own domain */
1356 1028 : fj_domain = makeNode(JoinDomain);
1357 1028 : root->join_domains = lappend(root->join_domains, fj_domain);
1358 1028 : jtitem->jdomain = fj_domain;
1359 : /* Recurse, giving each side its own join domain */
1360 1028 : child_domain = makeNode(JoinDomain);
1361 1028 : child_domain->jd_relids = NULL; /* filled by recursion */
1362 1028 : root->join_domains = lappend(root->join_domains, child_domain);
1363 1028 : leftjoinlist = deconstruct_recurse(root, j->larg,
1364 : child_domain,
1365 : jtitem,
1366 : item_list);
1367 1028 : left_item = (JoinTreeItem *) llast(*item_list);
1368 1028 : fj_domain->jd_relids = bms_copy(child_domain->jd_relids);
1369 1028 : child_domain = makeNode(JoinDomain);
1370 1028 : child_domain->jd_relids = NULL; /* filled by recursion */
1371 1028 : root->join_domains = lappend(root->join_domains, child_domain);
1372 1028 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1373 : child_domain,
1374 : jtitem,
1375 : item_list);
1376 1028 : right_item = (JoinTreeItem *) llast(*item_list);
1377 : /* Compute qualscope etc */
1378 2056 : fj_domain->jd_relids = bms_add_members(fj_domain->jd_relids,
1379 1028 : child_domain->jd_relids);
1380 2056 : parent_domain->jd_relids = bms_add_members(parent_domain->jd_relids,
1381 1028 : fj_domain->jd_relids);
1382 2056 : jtitem->qualscope = bms_union(left_item->qualscope,
1383 1028 : right_item->qualscope);
1384 : Assert(j->rtindex != 0);
1385 1028 : parent_domain->jd_relids = bms_add_member(parent_domain->jd_relids,
1386 : j->rtindex);
1387 1028 : jtitem->qualscope = bms_add_member(jtitem->qualscope,
1388 : j->rtindex);
1389 1028 : root->outer_join_rels = bms_add_member(root->outer_join_rels,
1390 : j->rtindex);
1391 1028 : mark_rels_nulled_by_join(root, j->rtindex,
1392 : left_item->qualscope);
1393 1028 : mark_rels_nulled_by_join(root, j->rtindex,
1394 : right_item->qualscope);
1395 2056 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1396 1028 : right_item->inner_join_rels);
1397 1028 : jtitem->left_rels = left_item->qualscope;
1398 1028 : jtitem->right_rels = right_item->qualscope;
1399 : /* each side is both outer and inner */
1400 1028 : jtitem->nonnullable_rels = jtitem->qualscope;
1401 1028 : break;
1402 0 : default:
1403 : /* JOIN_RIGHT was eliminated during reduce_outer_joins() */
1404 0 : elog(ERROR, "unrecognized join type: %d",
1405 : (int) j->jointype);
1406 : leftjoinlist = rightjoinlist = NIL; /* keep compiler quiet */
1407 : break;
1408 : }
1409 :
1410 : /*
1411 : * Compute the output joinlist. We fold subproblems together except
1412 : * at a FULL JOIN or where join_collapse_limit would be exceeded.
1413 : */
1414 95762 : if (j->jointype == JOIN_FULL)
1415 : {
1416 : /* force the join order exactly at this node */
1417 1028 : joinlist = list_make1(list_make2(leftjoinlist, rightjoinlist));
1418 : }
1419 94734 : else if (list_length(leftjoinlist) + list_length(rightjoinlist) <=
1420 : join_collapse_limit)
1421 : {
1422 : /* OK to combine subproblems */
1423 94566 : joinlist = list_concat(leftjoinlist, rightjoinlist);
1424 : }
1425 : else
1426 : {
1427 : /* can't combine, but needn't force join order above here */
1428 : Node *leftpart,
1429 : *rightpart;
1430 :
1431 : /* avoid creating useless 1-element sublists */
1432 168 : if (list_length(leftjoinlist) == 1)
1433 30 : leftpart = (Node *) linitial(leftjoinlist);
1434 : else
1435 138 : leftpart = (Node *) leftjoinlist;
1436 168 : if (list_length(rightjoinlist) == 1)
1437 24 : rightpart = (Node *) linitial(rightjoinlist);
1438 : else
1439 144 : rightpart = (Node *) rightjoinlist;
1440 168 : joinlist = list_make2(leftpart, rightpart);
1441 : }
1442 : }
1443 : else
1444 : {
1445 0 : elog(ERROR, "unrecognized node type: %d",
1446 : (int) nodeTag(jtnode));
1447 : joinlist = NIL; /* keep compiler quiet */
1448 : }
1449 :
1450 : /* Finally, we can add the new JoinTreeItem to item_list */
1451 911396 : *item_list = lappend(*item_list, jtitem);
1452 :
1453 911396 : return joinlist;
1454 : }
1455 :
1456 : /*
1457 : * deconstruct_distribute
1458 : * Process one jointree node in phase 2 of deconstruct_jointree processing.
1459 : *
1460 : * Distribute quals of the node to appropriate restriction and join lists.
1461 : * In addition, entries will be added to root->join_info_list for outer joins.
1462 : */
1463 : static void
1464 911396 : deconstruct_distribute(PlannerInfo *root, JoinTreeItem *jtitem)
1465 : {
1466 911396 : Node *jtnode = jtitem->jtnode;
1467 :
1468 911396 : if (IsA(jtnode, RangeTblRef))
1469 : {
1470 474706 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1471 :
1472 : /* Deal with any securityQuals attached to the RTE */
1473 474706 : if (root->qual_security_level > 0)
1474 2700 : process_security_barrier_quals(root,
1475 : varno,
1476 : jtitem);
1477 : }
1478 436690 : else if (IsA(jtnode, FromExpr))
1479 : {
1480 340928 : FromExpr *f = (FromExpr *) jtnode;
1481 :
1482 : /*
1483 : * Process any lateral-referencing quals that were postponed to this
1484 : * level by children.
1485 : */
1486 340928 : distribute_quals_to_rels(root, jtitem->lateral_clauses,
1487 : jtitem,
1488 : NULL,
1489 : root->qual_security_level,
1490 : jtitem->qualscope,
1491 : NULL, NULL, NULL,
1492 : true, false, false,
1493 : NULL);
1494 :
1495 : /*
1496 : * Now process the top-level quals.
1497 : */
1498 340928 : distribute_quals_to_rels(root, (List *) f->quals,
1499 : jtitem,
1500 : NULL,
1501 : root->qual_security_level,
1502 : jtitem->qualscope,
1503 : NULL, NULL, NULL,
1504 : true, false, false,
1505 : NULL);
1506 : }
1507 95762 : else if (IsA(jtnode, JoinExpr))
1508 : {
1509 95762 : JoinExpr *j = (JoinExpr *) jtnode;
1510 : Relids ojscope;
1511 : List *my_quals;
1512 : SpecialJoinInfo *sjinfo;
1513 : List **postponed_oj_qual_list;
1514 :
1515 : /*
1516 : * Include lateral-referencing quals postponed from children in
1517 : * my_quals, so that they'll be handled properly in
1518 : * make_outerjoininfo. (This is destructive to
1519 : * jtitem->lateral_clauses, but we won't use that again.)
1520 : */
1521 95762 : my_quals = list_concat(jtitem->lateral_clauses,
1522 95762 : (List *) j->quals);
1523 :
1524 : /*
1525 : * For an OJ, form the SpecialJoinInfo now, so that we can pass it to
1526 : * distribute_qual_to_rels. We must compute its ojscope too.
1527 : *
1528 : * Semijoins are a bit of a hybrid: we build a SpecialJoinInfo, but we
1529 : * want ojscope = NULL for distribute_qual_to_rels.
1530 : */
1531 95762 : if (j->jointype != JOIN_INNER)
1532 : {
1533 54678 : sjinfo = make_outerjoininfo(root,
1534 : jtitem->left_rels,
1535 : jtitem->right_rels,
1536 : jtitem->inner_join_rels,
1537 : j->jointype,
1538 54678 : j->rtindex,
1539 : my_quals);
1540 54678 : jtitem->sjinfo = sjinfo;
1541 54678 : if (j->jointype == JOIN_SEMI)
1542 4812 : ojscope = NULL;
1543 : else
1544 49866 : ojscope = bms_union(sjinfo->min_lefthand,
1545 49866 : sjinfo->min_righthand);
1546 : }
1547 : else
1548 : {
1549 41084 : sjinfo = NULL;
1550 41084 : ojscope = NULL;
1551 : }
1552 :
1553 : /*
1554 : * If it's a left join with a join clause that is strict for the LHS,
1555 : * then we need to postpone handling of any non-degenerate join
1556 : * clauses, in case the join is able to commute with another left join
1557 : * per identity 3. (Degenerate clauses need not be postponed, since
1558 : * they will drop down below this join anyway.)
1559 : */
1560 95762 : if (j->jointype == JOIN_LEFT && sjinfo->lhs_strict)
1561 : {
1562 43252 : postponed_oj_qual_list = &jtitem->oj_joinclauses;
1563 :
1564 : /*
1565 : * Add back any commutable lower OJ relids that were removed from
1566 : * min_lefthand or min_righthand, else the ojscope cross-check in
1567 : * distribute_qual_to_rels will complain. Since we are postponing
1568 : * processing of non-degenerate clauses, this addition doesn't
1569 : * affect anything except that cross-check. Real clause
1570 : * positioning decisions will be made later, when we revisit the
1571 : * postponed clauses.
1572 : */
1573 43252 : ojscope = bms_add_members(ojscope, sjinfo->commute_below_l);
1574 43252 : ojscope = bms_add_members(ojscope, sjinfo->commute_below_r);
1575 : }
1576 : else
1577 52510 : postponed_oj_qual_list = NULL;
1578 :
1579 : /* Process the JOIN's qual clauses */
1580 95762 : distribute_quals_to_rels(root, my_quals,
1581 : jtitem,
1582 : sjinfo,
1583 : root->qual_security_level,
1584 : jtitem->qualscope,
1585 : ojscope, jtitem->nonnullable_rels,
1586 : NULL, /* incompatible_relids */
1587 : true, /* allow_equivalence */
1588 : false, false, /* not clones */
1589 : postponed_oj_qual_list);
1590 :
1591 : /* And add the SpecialJoinInfo to join_info_list */
1592 95762 : if (sjinfo)
1593 54678 : root->join_info_list = lappend(root->join_info_list, sjinfo);
1594 : }
1595 : else
1596 : {
1597 0 : elog(ERROR, "unrecognized node type: %d",
1598 : (int) nodeTag(jtnode));
1599 : }
1600 911396 : }
1601 :
1602 : /*
1603 : * process_security_barrier_quals
1604 : * Transfer security-barrier quals into relation's baserestrictinfo list.
1605 : *
1606 : * The rewriter put any relevant security-barrier conditions into the RTE's
1607 : * securityQuals field, but it's now time to copy them into the rel's
1608 : * baserestrictinfo.
1609 : *
1610 : * In inheritance cases, we only consider quals attached to the parent rel
1611 : * here; they will be valid for all children too, so it's okay to consider
1612 : * them for purposes like equivalence class creation. Quals attached to
1613 : * individual child rels will be dealt with during path creation.
1614 : */
1615 : static void
1616 2700 : process_security_barrier_quals(PlannerInfo *root,
1617 : int rti, JoinTreeItem *jtitem)
1618 : {
1619 2700 : RangeTblEntry *rte = root->simple_rte_array[rti];
1620 2700 : Index security_level = 0;
1621 : ListCell *lc;
1622 :
1623 : /*
1624 : * Each element of the securityQuals list has been preprocessed into an
1625 : * implicitly-ANDed list of clauses. All the clauses in a given sublist
1626 : * should get the same security level, but successive sublists get higher
1627 : * levels.
1628 : */
1629 5530 : foreach(lc, rte->securityQuals)
1630 : {
1631 2830 : List *qualset = (List *) lfirst(lc);
1632 :
1633 : /*
1634 : * We cheat to the extent of passing ojscope = qualscope rather than
1635 : * its more logical value of NULL. The only effect this has is to
1636 : * force a Var-free qual to be evaluated at the rel rather than being
1637 : * pushed up to top of tree, which we don't want.
1638 : */
1639 2830 : distribute_quals_to_rels(root, qualset,
1640 : jtitem,
1641 : NULL,
1642 : security_level,
1643 : jtitem->qualscope,
1644 : jtitem->qualscope,
1645 : NULL,
1646 : NULL,
1647 : true,
1648 : false, false, /* not clones */
1649 : NULL);
1650 2830 : security_level++;
1651 : }
1652 :
1653 : /* Assert that qual_security_level is higher than anything we just used */
1654 : Assert(security_level <= root->qual_security_level);
1655 2700 : }
1656 :
1657 : /*
1658 : * mark_rels_nulled_by_join
1659 : * Fill RelOptInfo.nulling_relids of baserels nulled by this outer join
1660 : *
1661 : * Inputs:
1662 : * ojrelid: RT index of the join RTE (must not be 0)
1663 : * lower_rels: the base+OJ Relids syntactically below nullable side of join
1664 : */
1665 : static void
1666 47974 : mark_rels_nulled_by_join(PlannerInfo *root, Index ojrelid,
1667 : Relids lower_rels)
1668 : {
1669 47974 : int relid = -1;
1670 :
1671 98684 : while ((relid = bms_next_member(lower_rels, relid)) > 0)
1672 : {
1673 50710 : RelOptInfo *rel = root->simple_rel_array[relid];
1674 :
1675 : /* ignore the RTE_GROUP RTE */
1676 50710 : if (relid == root->group_rtindex)
1677 0 : continue;
1678 :
1679 50710 : if (rel == NULL) /* must be an outer join */
1680 : {
1681 : Assert(bms_is_member(relid, root->outer_join_rels));
1682 770 : continue;
1683 : }
1684 49940 : rel->nulling_relids = bms_add_member(rel->nulling_relids, ojrelid);
1685 : }
1686 47974 : }
1687 :
1688 : /*
1689 : * make_outerjoininfo
1690 : * Build a SpecialJoinInfo for the current outer join
1691 : *
1692 : * Inputs:
1693 : * left_rels: the base+OJ Relids syntactically on outer side of join
1694 : * right_rels: the base+OJ Relids syntactically on inner side of join
1695 : * inner_join_rels: base+OJ Relids participating in inner joins below this one
1696 : * jointype: what it says (must always be LEFT, FULL, SEMI, or ANTI)
1697 : * ojrelid: RT index of the join RTE (0 for SEMI, which isn't in the RT list)
1698 : * clause: the outer join's join condition (in implicit-AND format)
1699 : *
1700 : * The node should eventually be appended to root->join_info_list, but we
1701 : * do not do that here.
1702 : *
1703 : * Note: we assume that this function is invoked bottom-up, so that
1704 : * root->join_info_list already contains entries for all outer joins that are
1705 : * syntactically below this one.
1706 : */
1707 : static SpecialJoinInfo *
1708 54678 : make_outerjoininfo(PlannerInfo *root,
1709 : Relids left_rels, Relids right_rels,
1710 : Relids inner_join_rels,
1711 : JoinType jointype, Index ojrelid,
1712 : List *clause)
1713 : {
1714 54678 : SpecialJoinInfo *sjinfo = makeNode(SpecialJoinInfo);
1715 : Relids clause_relids;
1716 : Relids strict_relids;
1717 : Relids min_lefthand;
1718 : Relids min_righthand;
1719 : Relids commute_below_l;
1720 : Relids commute_below_r;
1721 : ListCell *l;
1722 :
1723 : /*
1724 : * We should not see RIGHT JOIN here because left/right were switched
1725 : * earlier
1726 : */
1727 : Assert(jointype != JOIN_INNER);
1728 : Assert(jointype != JOIN_RIGHT);
1729 :
1730 : /*
1731 : * Presently the executor cannot support FOR [KEY] UPDATE/SHARE marking of
1732 : * rels appearing on the nullable side of an outer join. (It's somewhat
1733 : * unclear what that would mean, anyway: what should we mark when a result
1734 : * row is generated from no element of the nullable relation?) So,
1735 : * complain if any nullable rel is FOR [KEY] UPDATE/SHARE.
1736 : *
1737 : * You might be wondering why this test isn't made far upstream in the
1738 : * parser. It's because the parser hasn't got enough info --- consider
1739 : * FOR UPDATE applied to a view. Only after rewriting and flattening do
1740 : * we know whether the view contains an outer join.
1741 : *
1742 : * We use the original RowMarkClause list here; the PlanRowMark list would
1743 : * list everything.
1744 : */
1745 54722 : foreach(l, root->parse->rowMarks)
1746 : {
1747 44 : RowMarkClause *rc = (RowMarkClause *) lfirst(l);
1748 :
1749 44 : if (bms_is_member(rc->rti, right_rels) ||
1750 8 : (jointype == JOIN_FULL && bms_is_member(rc->rti, left_rels)))
1751 0 : ereport(ERROR,
1752 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1753 : /*------
1754 : translator: %s is a SQL row locking clause such as FOR UPDATE */
1755 : errmsg("%s cannot be applied to the nullable side of an outer join",
1756 : LCS_asString(rc->strength))));
1757 : }
1758 :
1759 54678 : sjinfo->syn_lefthand = left_rels;
1760 54678 : sjinfo->syn_righthand = right_rels;
1761 54678 : sjinfo->jointype = jointype;
1762 54678 : sjinfo->ojrelid = ojrelid;
1763 : /* these fields may get added to later: */
1764 54678 : sjinfo->commute_above_l = NULL;
1765 54678 : sjinfo->commute_above_r = NULL;
1766 54678 : sjinfo->commute_below_l = NULL;
1767 54678 : sjinfo->commute_below_r = NULL;
1768 :
1769 54678 : compute_semijoin_info(root, sjinfo, clause);
1770 :
1771 : /* If it's a full join, no need to be very smart */
1772 54678 : if (jointype == JOIN_FULL)
1773 : {
1774 1028 : sjinfo->min_lefthand = bms_copy(left_rels);
1775 1028 : sjinfo->min_righthand = bms_copy(right_rels);
1776 1028 : sjinfo->lhs_strict = false; /* don't care about this */
1777 1028 : return sjinfo;
1778 : }
1779 :
1780 : /*
1781 : * Retrieve all relids mentioned within the join clause.
1782 : */
1783 53650 : clause_relids = pull_varnos(root, (Node *) clause);
1784 :
1785 : /*
1786 : * For which relids is the clause strict, ie, it cannot succeed if the
1787 : * rel's columns are all NULL?
1788 : */
1789 53650 : strict_relids = find_nonnullable_rels((Node *) clause);
1790 :
1791 : /* Remember whether the clause is strict for any LHS relations */
1792 53650 : sjinfo->lhs_strict = bms_overlap(strict_relids, left_rels);
1793 :
1794 : /*
1795 : * Required LHS always includes the LHS rels mentioned in the clause. We
1796 : * may have to add more rels based on lower outer joins; see below.
1797 : */
1798 53650 : min_lefthand = bms_intersect(clause_relids, left_rels);
1799 :
1800 : /*
1801 : * Similarly for required RHS. But here, we must also include any lower
1802 : * inner joins, to ensure we don't try to commute with any of them.
1803 : */
1804 53650 : min_righthand = bms_int_members(bms_union(clause_relids, inner_join_rels),
1805 : right_rels);
1806 :
1807 : /*
1808 : * Now check previous outer joins for ordering restrictions.
1809 : *
1810 : * commute_below_l and commute_below_r accumulate the relids of lower
1811 : * outer joins that we think this one can commute with. These decisions
1812 : * are just tentative within this loop, since we might find an
1813 : * intermediate outer join that prevents commutation. Surviving relids
1814 : * will get merged into the SpecialJoinInfo structs afterwards.
1815 : */
1816 53650 : commute_below_l = commute_below_r = NULL;
1817 70798 : foreach(l, root->join_info_list)
1818 : {
1819 17148 : SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l);
1820 : bool have_unsafe_phvs;
1821 :
1822 : /*
1823 : * A full join is an optimization barrier: we can't associate into or
1824 : * out of it. Hence, if it overlaps either LHS or RHS of the current
1825 : * rel, expand that side's min relset to cover the whole full join.
1826 : */
1827 17148 : if (otherinfo->jointype == JOIN_FULL)
1828 : {
1829 : Assert(otherinfo->ojrelid != 0);
1830 94 : if (bms_overlap(left_rels, otherinfo->syn_lefthand) ||
1831 30 : bms_overlap(left_rels, otherinfo->syn_righthand))
1832 : {
1833 34 : min_lefthand = bms_add_members(min_lefthand,
1834 34 : otherinfo->syn_lefthand);
1835 34 : min_lefthand = bms_add_members(min_lefthand,
1836 34 : otherinfo->syn_righthand);
1837 34 : min_lefthand = bms_add_member(min_lefthand,
1838 34 : otherinfo->ojrelid);
1839 : }
1840 98 : if (bms_overlap(right_rels, otherinfo->syn_lefthand) ||
1841 34 : bms_overlap(right_rels, otherinfo->syn_righthand))
1842 : {
1843 30 : min_righthand = bms_add_members(min_righthand,
1844 30 : otherinfo->syn_lefthand);
1845 30 : min_righthand = bms_add_members(min_righthand,
1846 30 : otherinfo->syn_righthand);
1847 30 : min_righthand = bms_add_member(min_righthand,
1848 30 : otherinfo->ojrelid);
1849 : }
1850 : /* Needn't do anything else with the full join */
1851 64 : continue;
1852 : }
1853 :
1854 : /*
1855 : * If our join condition contains any PlaceHolderVars that need to be
1856 : * evaluated above the lower OJ, then we can't commute with it.
1857 : */
1858 17084 : if (otherinfo->ojrelid != 0)
1859 : have_unsafe_phvs =
1860 16740 : contain_placeholder_references_to(root,
1861 : (Node *) clause,
1862 16740 : otherinfo->ojrelid);
1863 : else
1864 344 : have_unsafe_phvs = false;
1865 :
1866 : /*
1867 : * For a lower OJ in our LHS, if our join condition uses the lower
1868 : * join's RHS and is not strict for that rel, we must preserve the
1869 : * ordering of the two OJs, so add lower OJ's full syntactic relset to
1870 : * min_lefthand. (We must use its full syntactic relset, not just its
1871 : * min_lefthand + min_righthand. This is because there might be other
1872 : * OJs below this one that this one can commute with, but we cannot
1873 : * commute with them if we don't with this one.) Also, if we have
1874 : * unsafe PHVs or the current join is a semijoin or antijoin, we must
1875 : * preserve ordering regardless of strictness.
1876 : *
1877 : * Note: I believe we have to insist on being strict for at least one
1878 : * rel in the lower OJ's min_righthand, not its whole syn_righthand.
1879 : *
1880 : * When we don't need to preserve ordering, check to see if outer join
1881 : * identity 3 applies, and if so, remove the lower OJ's ojrelid from
1882 : * our min_lefthand so that commutation is allowed.
1883 : */
1884 17084 : if (bms_overlap(left_rels, otherinfo->syn_righthand))
1885 : {
1886 16238 : if (bms_overlap(clause_relids, otherinfo->syn_righthand) &&
1887 4596 : (have_unsafe_phvs ||
1888 4596 : jointype == JOIN_SEMI || jointype == JOIN_ANTI ||
1889 4596 : !bms_overlap(strict_relids, otherinfo->min_righthand)))
1890 : {
1891 : /* Preserve ordering */
1892 42 : min_lefthand = bms_add_members(min_lefthand,
1893 42 : otherinfo->syn_lefthand);
1894 42 : min_lefthand = bms_add_members(min_lefthand,
1895 42 : otherinfo->syn_righthand);
1896 42 : if (otherinfo->ojrelid != 0)
1897 42 : min_lefthand = bms_add_member(min_lefthand,
1898 42 : otherinfo->ojrelid);
1899 : }
1900 16196 : else if (jointype == JOIN_LEFT &&
1901 30972 : otherinfo->jointype == JOIN_LEFT &&
1902 15484 : bms_overlap(strict_relids, otherinfo->min_righthand) &&
1903 4566 : !bms_overlap(clause_relids, otherinfo->syn_lefthand))
1904 : {
1905 : /* Identity 3 applies, so remove the ordering restriction */
1906 4506 : min_lefthand = bms_del_member(min_lefthand, otherinfo->ojrelid);
1907 : /* Record the (still tentative) commutability relationship */
1908 : commute_below_l =
1909 4506 : bms_add_member(commute_below_l, otherinfo->ojrelid);
1910 : }
1911 : }
1912 :
1913 : /*
1914 : * For a lower OJ in our RHS, if our join condition does not use the
1915 : * lower join's RHS and the lower OJ's join condition is strict, we
1916 : * can interchange the ordering of the two OJs; otherwise we must add
1917 : * the lower OJ's full syntactic relset to min_righthand.
1918 : *
1919 : * Also, if our join condition does not use the lower join's LHS
1920 : * either, force the ordering to be preserved. Otherwise we can end
1921 : * up with SpecialJoinInfos with identical min_righthands, which can
1922 : * confuse join_is_legal (see discussion in backend/optimizer/README).
1923 : *
1924 : * Also, we must preserve ordering anyway if we have unsafe PHVs, or
1925 : * if either this join or the lower OJ is a semijoin or antijoin.
1926 : *
1927 : * When we don't need to preserve ordering, check to see if outer join
1928 : * identity 3 applies, and if so, remove the lower OJ's ojrelid from
1929 : * our min_righthand so that commutation is allowed.
1930 : */
1931 17084 : if (bms_overlap(right_rels, otherinfo->syn_righthand))
1932 : {
1933 760 : if (bms_overlap(clause_relids, otherinfo->syn_righthand) ||
1934 712 : !bms_overlap(clause_relids, otherinfo->min_lefthand) ||
1935 400 : have_unsafe_phvs ||
1936 310 : jointype == JOIN_SEMI ||
1937 304 : jointype == JOIN_ANTI ||
1938 304 : otherinfo->jointype == JOIN_SEMI ||
1939 244 : otherinfo->jointype == JOIN_ANTI ||
1940 244 : !otherinfo->lhs_strict)
1941 : {
1942 : /* Preserve ordering */
1943 540 : min_righthand = bms_add_members(min_righthand,
1944 540 : otherinfo->syn_lefthand);
1945 540 : min_righthand = bms_add_members(min_righthand,
1946 540 : otherinfo->syn_righthand);
1947 540 : if (otherinfo->ojrelid != 0)
1948 390 : min_righthand = bms_add_member(min_righthand,
1949 390 : otherinfo->ojrelid);
1950 : }
1951 220 : else if (jointype == JOIN_LEFT &&
1952 220 : otherinfo->jointype == JOIN_LEFT &&
1953 220 : otherinfo->lhs_strict)
1954 : {
1955 : /* Identity 3 applies, so remove the ordering restriction */
1956 220 : min_righthand = bms_del_member(min_righthand,
1957 220 : otherinfo->ojrelid);
1958 : /* Record the (still tentative) commutability relationship */
1959 : commute_below_r =
1960 220 : bms_add_member(commute_below_r, otherinfo->ojrelid);
1961 : }
1962 : }
1963 : }
1964 :
1965 : /*
1966 : * Examine PlaceHolderVars. If a PHV is supposed to be evaluated within
1967 : * this join's nullable side, then ensure that min_righthand contains the
1968 : * full eval_at set of the PHV. This ensures that the PHV actually can be
1969 : * evaluated within the RHS. Note that this works only because we should
1970 : * already have determined the final eval_at level for any PHV
1971 : * syntactically within this join.
1972 : */
1973 55038 : foreach(l, root->placeholder_list)
1974 : {
1975 1388 : PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(l);
1976 1388 : Relids ph_syn_level = phinfo->ph_var->phrels;
1977 :
1978 : /* Ignore placeholder if it didn't syntactically come from RHS */
1979 1388 : if (!bms_is_subset(ph_syn_level, right_rels))
1980 496 : continue;
1981 :
1982 : /* Else, prevent join from being formed before we eval the PHV */
1983 892 : min_righthand = bms_add_members(min_righthand, phinfo->ph_eval_at);
1984 : }
1985 :
1986 : /*
1987 : * If we found nothing to put in min_lefthand, punt and make it the full
1988 : * LHS, to avoid having an empty min_lefthand which will confuse later
1989 : * processing. (We don't try to be smart about such cases, just correct.)
1990 : * Likewise for min_righthand.
1991 : */
1992 53650 : if (bms_is_empty(min_lefthand))
1993 1380 : min_lefthand = bms_copy(left_rels);
1994 53650 : if (bms_is_empty(min_righthand))
1995 500 : min_righthand = bms_copy(right_rels);
1996 :
1997 : /* Now they'd better be nonempty */
1998 : Assert(!bms_is_empty(min_lefthand));
1999 : Assert(!bms_is_empty(min_righthand));
2000 : /* Shouldn't overlap either */
2001 : Assert(!bms_overlap(min_lefthand, min_righthand));
2002 :
2003 53650 : sjinfo->min_lefthand = min_lefthand;
2004 53650 : sjinfo->min_righthand = min_righthand;
2005 :
2006 : /*
2007 : * Now that we've identified the correct min_lefthand and min_righthand,
2008 : * any commute_below_l or commute_below_r relids that have not gotten
2009 : * added back into those sets (due to intervening outer joins) are indeed
2010 : * commutable with this one.
2011 : *
2012 : * First, delete any subsequently-added-back relids (this is easier than
2013 : * maintaining commute_below_l/r precisely through all the above).
2014 : */
2015 53650 : commute_below_l = bms_del_members(commute_below_l, min_lefthand);
2016 53650 : commute_below_r = bms_del_members(commute_below_r, min_righthand);
2017 :
2018 : /* Anything left? */
2019 53650 : if (commute_below_l || commute_below_r)
2020 : {
2021 : /* Yup, so we must update the derived data in the SpecialJoinInfos */
2022 4648 : sjinfo->commute_below_l = commute_below_l;
2023 4648 : sjinfo->commute_below_r = commute_below_r;
2024 9816 : foreach(l, root->join_info_list)
2025 : {
2026 5168 : SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l);
2027 :
2028 5168 : if (bms_is_member(otherinfo->ojrelid, commute_below_l))
2029 4506 : otherinfo->commute_above_l =
2030 4506 : bms_add_member(otherinfo->commute_above_l, ojrelid);
2031 662 : else if (bms_is_member(otherinfo->ojrelid, commute_below_r))
2032 190 : otherinfo->commute_above_r =
2033 190 : bms_add_member(otherinfo->commute_above_r, ojrelid);
2034 : }
2035 : }
2036 :
2037 53650 : return sjinfo;
2038 : }
2039 :
2040 : /*
2041 : * compute_semijoin_info
2042 : * Fill semijoin-related fields of a new SpecialJoinInfo
2043 : *
2044 : * Note: this relies on only the jointype and syn_righthand fields of the
2045 : * SpecialJoinInfo; the rest may not be set yet.
2046 : */
2047 : static void
2048 54678 : compute_semijoin_info(PlannerInfo *root, SpecialJoinInfo *sjinfo, List *clause)
2049 : {
2050 : List *semi_operators;
2051 : List *semi_rhs_exprs;
2052 : bool all_btree;
2053 : bool all_hash;
2054 : ListCell *lc;
2055 :
2056 : /* Initialize semijoin-related fields in case we can't unique-ify */
2057 54678 : sjinfo->semi_can_btree = false;
2058 54678 : sjinfo->semi_can_hash = false;
2059 54678 : sjinfo->semi_operators = NIL;
2060 54678 : sjinfo->semi_rhs_exprs = NIL;
2061 :
2062 : /* Nothing more to do if it's not a semijoin */
2063 54678 : if (sjinfo->jointype != JOIN_SEMI)
2064 49866 : return;
2065 :
2066 : /*
2067 : * Look to see whether the semijoin's join quals consist of AND'ed
2068 : * equality operators, with (only) RHS variables on only one side of each
2069 : * one. If so, we can figure out how to enforce uniqueness for the RHS.
2070 : *
2071 : * Note that the input clause list is the list of quals that are
2072 : * *syntactically* associated with the semijoin, which in practice means
2073 : * the synthesized comparison list for an IN or the WHERE of an EXISTS.
2074 : * Particularly in the latter case, it might contain clauses that aren't
2075 : * *semantically* associated with the join, but refer to just one side or
2076 : * the other. We can ignore such clauses here, as they will just drop
2077 : * down to be processed within one side or the other. (It is okay to
2078 : * consider only the syntactically-associated clauses here because for a
2079 : * semijoin, no higher-level quals could refer to the RHS, and so there
2080 : * can be no other quals that are semantically associated with this join.
2081 : * We do things this way because it is useful to have the set of potential
2082 : * unique-ification expressions before we can extract the list of quals
2083 : * that are actually semantically associated with the particular join.)
2084 : *
2085 : * Note that the semi_operators list consists of the joinqual operators
2086 : * themselves (but commuted if needed to put the RHS value on the right).
2087 : * These could be cross-type operators, in which case the operator
2088 : * actually needed for uniqueness is a related single-type operator. We
2089 : * assume here that that operator will be available from the btree or hash
2090 : * opclass when the time comes ... if not, create_unique_plan() will fail.
2091 : */
2092 4812 : semi_operators = NIL;
2093 4812 : semi_rhs_exprs = NIL;
2094 4812 : all_btree = true;
2095 4812 : all_hash = enable_hashagg; /* don't consider hash if not enabled */
2096 9910 : foreach(lc, clause)
2097 : {
2098 5200 : OpExpr *op = (OpExpr *) lfirst(lc);
2099 : Oid opno;
2100 : Node *left_expr;
2101 : Node *right_expr;
2102 : Relids left_varnos;
2103 : Relids right_varnos;
2104 : Relids all_varnos;
2105 : Oid opinputtype;
2106 :
2107 : /* Is it a binary opclause? */
2108 10292 : if (!IsA(op, OpExpr) ||
2109 5092 : list_length(op->args) != 2)
2110 : {
2111 : /* No, but does it reference both sides? */
2112 108 : all_varnos = pull_varnos(root, (Node *) op);
2113 204 : if (!bms_overlap(all_varnos, sjinfo->syn_righthand) ||
2114 96 : bms_is_subset(all_varnos, sjinfo->syn_righthand))
2115 : {
2116 : /*
2117 : * Clause refers to only one rel, so ignore it --- unless it
2118 : * contains volatile functions, in which case we'd better
2119 : * punt.
2120 : */
2121 96 : if (contain_volatile_functions((Node *) op))
2122 102 : return;
2123 96 : continue;
2124 : }
2125 : /* Non-operator clause referencing both sides, must punt */
2126 12 : return;
2127 : }
2128 :
2129 : /* Extract data from binary opclause */
2130 5092 : opno = op->opno;
2131 5092 : left_expr = linitial(op->args);
2132 5092 : right_expr = lsecond(op->args);
2133 5092 : left_varnos = pull_varnos(root, left_expr);
2134 5092 : right_varnos = pull_varnos(root, right_expr);
2135 5092 : all_varnos = bms_union(left_varnos, right_varnos);
2136 5092 : opinputtype = exprType(left_expr);
2137 :
2138 : /* Does it reference both sides? */
2139 10176 : if (!bms_overlap(all_varnos, sjinfo->syn_righthand) ||
2140 5084 : bms_is_subset(all_varnos, sjinfo->syn_righthand))
2141 : {
2142 : /*
2143 : * Clause refers to only one rel, so ignore it --- unless it
2144 : * contains volatile functions, in which case we'd better punt.
2145 : */
2146 82 : if (contain_volatile_functions((Node *) op))
2147 0 : return;
2148 82 : continue;
2149 : }
2150 :
2151 : /* check rel membership of arguments */
2152 10020 : if (!bms_is_empty(right_varnos) &&
2153 5010 : bms_is_subset(right_varnos, sjinfo->syn_righthand) &&
2154 4556 : !bms_overlap(left_varnos, sjinfo->syn_righthand))
2155 : {
2156 : /* typical case, right_expr is RHS variable */
2157 : }
2158 908 : else if (!bms_is_empty(left_varnos) &&
2159 454 : bms_is_subset(left_varnos, sjinfo->syn_righthand) &&
2160 448 : !bms_overlap(right_varnos, sjinfo->syn_righthand))
2161 : {
2162 : /* flipped case, left_expr is RHS variable */
2163 448 : opno = get_commutator(opno);
2164 448 : if (!OidIsValid(opno))
2165 0 : return;
2166 448 : right_expr = left_expr;
2167 : }
2168 : else
2169 : {
2170 : /* mixed membership of args, punt */
2171 6 : return;
2172 : }
2173 :
2174 : /* all operators must be btree equality or hash equality */
2175 5004 : if (all_btree)
2176 : {
2177 : /* oprcanmerge is considered a hint... */
2178 9924 : if (!op_mergejoinable(opno, opinputtype) ||
2179 4920 : get_mergejoin_opfamilies(opno) == NIL)
2180 84 : all_btree = false;
2181 : }
2182 5004 : if (all_hash)
2183 : {
2184 : /* ... but oprcanhash had better be correct */
2185 4932 : if (!op_hashjoinable(opno, opinputtype))
2186 84 : all_hash = false;
2187 : }
2188 5004 : if (!(all_btree || all_hash))
2189 84 : return;
2190 :
2191 : /* so far so good, keep building lists */
2192 4920 : semi_operators = lappend_oid(semi_operators, opno);
2193 4920 : semi_rhs_exprs = lappend(semi_rhs_exprs, copyObject(right_expr));
2194 : }
2195 :
2196 : /* Punt if we didn't find at least one column to unique-ify */
2197 4710 : if (semi_rhs_exprs == NIL)
2198 12 : return;
2199 :
2200 : /*
2201 : * The expressions we'd need to unique-ify mustn't be volatile.
2202 : */
2203 4698 : if (contain_volatile_functions((Node *) semi_rhs_exprs))
2204 0 : return;
2205 :
2206 : /*
2207 : * If we get here, we can unique-ify the semijoin's RHS using at least one
2208 : * of sorting and hashing. Save the information about how to do that.
2209 : */
2210 4698 : sjinfo->semi_can_btree = all_btree;
2211 4698 : sjinfo->semi_can_hash = all_hash;
2212 4698 : sjinfo->semi_operators = semi_operators;
2213 4698 : sjinfo->semi_rhs_exprs = semi_rhs_exprs;
2214 : }
2215 :
2216 : /*
2217 : * deconstruct_distribute_oj_quals
2218 : * Adjust LEFT JOIN quals to be suitable for commuted-left-join cases,
2219 : * then push them into the joinqual lists and EquivalenceClass structures.
2220 : *
2221 : * This runs immediately after we've completed the deconstruct_distribute scan.
2222 : * jtitems contains all the JoinTreeItems (in depth-first order), and jtitem
2223 : * is one that has postponed oj_joinclauses to deal with.
2224 : */
2225 : static void
2226 43252 : deconstruct_distribute_oj_quals(PlannerInfo *root,
2227 : List *jtitems,
2228 : JoinTreeItem *jtitem)
2229 : {
2230 43252 : SpecialJoinInfo *sjinfo = jtitem->sjinfo;
2231 : Relids qualscope,
2232 : ojscope,
2233 : nonnullable_rels;
2234 :
2235 : /* Recompute syntactic and semantic scopes of this left join */
2236 43252 : qualscope = bms_union(sjinfo->syn_lefthand, sjinfo->syn_righthand);
2237 43252 : qualscope = bms_add_member(qualscope, sjinfo->ojrelid);
2238 43252 : ojscope = bms_union(sjinfo->min_lefthand, sjinfo->min_righthand);
2239 43252 : nonnullable_rels = sjinfo->syn_lefthand;
2240 :
2241 : /*
2242 : * If this join can commute with any other ones per outer-join identity 3,
2243 : * and it is the one providing the join clause with flexible semantics,
2244 : * then we have to generate variants of the join clause with different
2245 : * nullingrels labeling. Otherwise, just push out the postponed clause
2246 : * as-is.
2247 : */
2248 : Assert(sjinfo->lhs_strict); /* else we shouldn't be here */
2249 43252 : if (sjinfo->commute_above_r || sjinfo->commute_below_l)
2250 4660 : {
2251 : Relids joins_above;
2252 : Relids joins_below;
2253 : Relids incompatible_joins;
2254 : Relids joins_so_far;
2255 : List *quals;
2256 : int save_last_rinfo_serial;
2257 : ListCell *lc;
2258 :
2259 : /* Identify the outer joins this one commutes with */
2260 4660 : joins_above = sjinfo->commute_above_r;
2261 4660 : joins_below = sjinfo->commute_below_l;
2262 :
2263 : /*
2264 : * Generate qual variants with different sets of nullingrels bits.
2265 : *
2266 : * We only need bit-sets that correspond to the successively less
2267 : * deeply syntactically-nested subsets of this join and its
2268 : * commutators. That's true first because obviously only those forms
2269 : * of the Vars and PHVs could appear elsewhere in the query, and
2270 : * second because the outer join identities do not provide a way to
2271 : * re-order such joins in a way that would require different marking.
2272 : * (That is, while the current join may commute with several others,
2273 : * none of those others can commute with each other.) To visit the
2274 : * interesting joins in syntactic nesting order, we rely on the
2275 : * jtitems list to be ordered that way.
2276 : *
2277 : * We first strip out all the nullingrels bits corresponding to
2278 : * commuting joins below this one, and then successively put them back
2279 : * as we crawl up the join stack.
2280 : */
2281 4660 : quals = jtitem->oj_joinclauses;
2282 4660 : if (!bms_is_empty(joins_below))
2283 4470 : quals = (List *) remove_nulling_relids((Node *) quals,
2284 : joins_below,
2285 : NULL);
2286 :
2287 : /*
2288 : * We'll need to mark the lower versions of the quals as not safe to
2289 : * apply above not-yet-processed joins of the stack. This prevents
2290 : * possibly applying a cloned qual at the wrong join level.
2291 : */
2292 4660 : incompatible_joins = bms_union(joins_below, joins_above);
2293 4660 : incompatible_joins = bms_add_member(incompatible_joins,
2294 4660 : sjinfo->ojrelid);
2295 :
2296 : /*
2297 : * Each time we produce RestrictInfo(s) from these quals, reset the
2298 : * last_rinfo_serial counter, so that the RestrictInfos for the "same"
2299 : * qual condition get identical serial numbers. (This relies on the
2300 : * fact that we're not changing the qual list in any way that'd affect
2301 : * the number of RestrictInfos built from it.) This'll allow us to
2302 : * detect duplicative qual usage later.
2303 : */
2304 4660 : save_last_rinfo_serial = root->last_rinfo_serial;
2305 :
2306 4660 : joins_so_far = NULL;
2307 39744 : foreach(lc, jtitems)
2308 : {
2309 35084 : JoinTreeItem *otherjtitem = (JoinTreeItem *) lfirst(lc);
2310 35084 : SpecialJoinInfo *othersj = otherjtitem->sjinfo;
2311 35084 : bool below_sjinfo = false;
2312 35084 : bool above_sjinfo = false;
2313 : Relids this_qualscope;
2314 : Relids this_ojscope;
2315 : bool allow_equivalence,
2316 : has_clone,
2317 : is_clone;
2318 :
2319 35084 : if (othersj == NULL)
2320 25000 : continue; /* not an outer-join item, ignore */
2321 :
2322 10084 : if (bms_is_member(othersj->ojrelid, joins_below))
2323 : {
2324 : /* othersj commutes with sjinfo from below left */
2325 4506 : below_sjinfo = true;
2326 : }
2327 5578 : else if (othersj == sjinfo)
2328 : {
2329 : /* found our join in syntactic order */
2330 : Assert(bms_equal(joins_so_far, joins_below));
2331 : }
2332 918 : else if (bms_is_member(othersj->ojrelid, joins_above))
2333 : {
2334 : /* othersj commutes with sjinfo from above */
2335 190 : above_sjinfo = true;
2336 : }
2337 : else
2338 : {
2339 : /* othersj is not relevant, ignore */
2340 728 : continue;
2341 : }
2342 :
2343 : /* Reset serial counter for this version of the quals */
2344 9356 : root->last_rinfo_serial = save_last_rinfo_serial;
2345 :
2346 : /*
2347 : * When we are looking at joins above sjinfo, we are envisioning
2348 : * pushing sjinfo to above othersj, so add othersj's nulling bit
2349 : * before distributing the quals. We should add it to Vars coming
2350 : * from the current join's LHS: we want to transform the second
2351 : * form of OJ identity 3 to the first form, in which Vars of
2352 : * relation B will appear nulled by the syntactically-upper OJ
2353 : * within the Pbc clause, but those of relation C will not. (In
2354 : * the notation used by optimizer/README, we're converting a qual
2355 : * of the form Pbc to Pb*c.) Of course, we must also remove that
2356 : * bit from the incompatible_joins value, else we'll make a qual
2357 : * that can't be placed anywhere.
2358 : */
2359 9356 : if (above_sjinfo)
2360 : {
2361 : quals = (List *)
2362 190 : add_nulling_relids((Node *) quals,
2363 190 : sjinfo->syn_lefthand,
2364 190 : bms_make_singleton(othersj->ojrelid));
2365 190 : incompatible_joins = bms_del_member(incompatible_joins,
2366 190 : othersj->ojrelid);
2367 : }
2368 :
2369 : /* Compute qualscope and ojscope for this join level */
2370 9356 : this_qualscope = bms_union(qualscope, joins_so_far);
2371 9356 : this_ojscope = bms_union(ojscope, joins_so_far);
2372 9356 : if (above_sjinfo)
2373 : {
2374 : /* othersj is not yet in joins_so_far, but we need it */
2375 190 : this_qualscope = bms_add_member(this_qualscope,
2376 190 : othersj->ojrelid);
2377 190 : this_ojscope = bms_add_member(this_ojscope,
2378 190 : othersj->ojrelid);
2379 : /* sjinfo is in joins_so_far, and we don't want it */
2380 190 : this_ojscope = bms_del_member(this_ojscope,
2381 190 : sjinfo->ojrelid);
2382 : }
2383 :
2384 : /*
2385 : * We generate EquivalenceClasses only from the first form of the
2386 : * quals, with the fewest nullingrels bits set. An EC made from
2387 : * this version of the quals can be useful below the outer-join
2388 : * nest, whereas versions with some nullingrels bits set would not
2389 : * be. We cannot generate ECs from more than one version, or
2390 : * we'll make nonsensical conclusions that Vars with nullingrels
2391 : * bits set are equal to their versions without. Fortunately,
2392 : * such ECs wouldn't be very useful anyway, because they'd equate
2393 : * values not observable outside the join nest. (See
2394 : * optimizer/README.)
2395 : *
2396 : * The first form of the quals is also the only one marked as
2397 : * has_clone rather than is_clone.
2398 : */
2399 9356 : allow_equivalence = (joins_so_far == NULL);
2400 9356 : has_clone = allow_equivalence;
2401 9356 : is_clone = !has_clone;
2402 :
2403 9356 : distribute_quals_to_rels(root, quals,
2404 : otherjtitem,
2405 : sjinfo,
2406 : root->qual_security_level,
2407 : this_qualscope,
2408 : this_ojscope, nonnullable_rels,
2409 : bms_copy(incompatible_joins),
2410 : allow_equivalence,
2411 : has_clone,
2412 : is_clone,
2413 : NULL); /* no more postponement */
2414 :
2415 : /*
2416 : * Adjust qual nulling bits for next level up, if needed. We
2417 : * don't want to put sjinfo's own bit in at all, and if we're
2418 : * above sjinfo then we did it already. Here, we should mark all
2419 : * Vars coming from the lower join's RHS. (Again, we are
2420 : * converting a qual of the form Pbc to Pb*c, but now we are
2421 : * putting back bits that were there in the parser output and were
2422 : * temporarily stripped above.) Update incompatible_joins too.
2423 : */
2424 9356 : if (below_sjinfo)
2425 : {
2426 : quals = (List *)
2427 4506 : add_nulling_relids((Node *) quals,
2428 4506 : othersj->syn_righthand,
2429 4506 : bms_make_singleton(othersj->ojrelid));
2430 4506 : incompatible_joins = bms_del_member(incompatible_joins,
2431 4506 : othersj->ojrelid);
2432 : }
2433 :
2434 : /* ... and track joins processed so far */
2435 9356 : joins_so_far = bms_add_member(joins_so_far, othersj->ojrelid);
2436 : }
2437 : }
2438 : else
2439 : {
2440 : /* No commutation possible, just process the postponed clauses */
2441 38592 : distribute_quals_to_rels(root, jtitem->oj_joinclauses,
2442 : jtitem,
2443 : sjinfo,
2444 : root->qual_security_level,
2445 : qualscope,
2446 : ojscope, nonnullable_rels,
2447 : NULL, /* incompatible_relids */
2448 : true, /* allow_equivalence */
2449 : false, false, /* not clones */
2450 : NULL); /* no more postponement */
2451 : }
2452 43252 : }
2453 :
2454 :
2455 : /*****************************************************************************
2456 : *
2457 : * QUALIFICATIONS
2458 : *
2459 : *****************************************************************************/
2460 :
2461 : /*
2462 : * distribute_quals_to_rels
2463 : * Convenience routine to apply distribute_qual_to_rels to each element
2464 : * of an AND'ed list of clauses.
2465 : */
2466 : static void
2467 828396 : distribute_quals_to_rels(PlannerInfo *root, List *clauses,
2468 : JoinTreeItem *jtitem,
2469 : SpecialJoinInfo *sjinfo,
2470 : Index security_level,
2471 : Relids qualscope,
2472 : Relids ojscope,
2473 : Relids outerjoin_nonnullable,
2474 : Relids incompatible_relids,
2475 : bool allow_equivalence,
2476 : bool has_clone,
2477 : bool is_clone,
2478 : List **postponed_oj_qual_list)
2479 : {
2480 : ListCell *lc;
2481 :
2482 1417990 : foreach(lc, clauses)
2483 : {
2484 589594 : Node *clause = (Node *) lfirst(lc);
2485 :
2486 589594 : distribute_qual_to_rels(root, clause,
2487 : jtitem,
2488 : sjinfo,
2489 : security_level,
2490 : qualscope,
2491 : ojscope,
2492 : outerjoin_nonnullable,
2493 : incompatible_relids,
2494 : allow_equivalence,
2495 : has_clone,
2496 : is_clone,
2497 : postponed_oj_qual_list);
2498 : }
2499 828396 : }
2500 :
2501 : /*
2502 : * distribute_qual_to_rels
2503 : * Add clause information to either the baserestrictinfo or joininfo list
2504 : * (depending on whether the clause is a join) of each base relation
2505 : * mentioned in the clause. A RestrictInfo node is created and added to
2506 : * the appropriate list for each rel. Alternatively, if the clause uses a
2507 : * mergejoinable operator, enter its left- and right-side expressions into
2508 : * the query's EquivalenceClasses.
2509 : *
2510 : * In some cases, quals will be added to parent jtitems' lateral_clauses
2511 : * or to postponed_oj_qual_list instead of being processed right away.
2512 : * These will be dealt with in later calls of deconstruct_distribute.
2513 : *
2514 : * 'clause': the qual clause to be distributed
2515 : * 'jtitem': the JoinTreeItem for the containing jointree node
2516 : * 'sjinfo': join's SpecialJoinInfo (NULL for an inner join or WHERE clause)
2517 : * 'security_level': security_level to assign to the qual
2518 : * 'qualscope': set of base+OJ rels the qual's syntactic scope covers
2519 : * 'ojscope': NULL if not an outer-join qual, else the minimum set of base+OJ
2520 : * rels needed to form this join
2521 : * 'outerjoin_nonnullable': NULL if not an outer-join qual, else the set of
2522 : * base+OJ rels appearing on the outer (nonnullable) side of the join
2523 : * (for FULL JOIN this includes both sides of the join, and must in fact
2524 : * equal qualscope)
2525 : * 'incompatible_relids': the set of outer-join relid(s) that must not be
2526 : * computed below this qual. We only bother to compute this for
2527 : * "clone" quals, otherwise it can be left NULL.
2528 : * 'allow_equivalence': true if it's okay to convert clause into an
2529 : * EquivalenceClass
2530 : * 'has_clone': has_clone property to assign to the qual
2531 : * 'is_clone': is_clone property to assign to the qual
2532 : * 'postponed_oj_qual_list': if not NULL, non-degenerate outer join clauses
2533 : * should be added to this list instead of being processed (list entries
2534 : * are just the bare clauses)
2535 : *
2536 : * 'qualscope' identifies what level of JOIN the qual came from syntactically.
2537 : * 'ojscope' is needed if we decide to force the qual up to the outer-join
2538 : * level, which will be ojscope not necessarily qualscope.
2539 : *
2540 : * At the time this is called, root->join_info_list must contain entries for
2541 : * at least those special joins that are syntactically below this qual.
2542 : * (We now need that only for detection of redundant IS NULL quals.)
2543 : */
2544 : static void
2545 589594 : distribute_qual_to_rels(PlannerInfo *root, Node *clause,
2546 : JoinTreeItem *jtitem,
2547 : SpecialJoinInfo *sjinfo,
2548 : Index security_level,
2549 : Relids qualscope,
2550 : Relids ojscope,
2551 : Relids outerjoin_nonnullable,
2552 : Relids incompatible_relids,
2553 : bool allow_equivalence,
2554 : bool has_clone,
2555 : bool is_clone,
2556 : List **postponed_oj_qual_list)
2557 : {
2558 : Relids relids;
2559 : bool is_pushed_down;
2560 589594 : bool pseudoconstant = false;
2561 : bool maybe_equivalence;
2562 : bool maybe_outer_join;
2563 : RestrictInfo *restrictinfo;
2564 :
2565 : /*
2566 : * Retrieve all relids mentioned within the clause.
2567 : */
2568 589594 : relids = pull_varnos(root, clause);
2569 :
2570 : /*
2571 : * In ordinary SQL, a WHERE or JOIN/ON clause can't reference any rels
2572 : * that aren't within its syntactic scope; however, if we pulled up a
2573 : * LATERAL subquery then we might find such references in quals that have
2574 : * been pulled up. We need to treat such quals as belonging to the join
2575 : * level that includes every rel they reference. Although we could make
2576 : * pull_up_subqueries() place such quals correctly to begin with, it's
2577 : * easier to handle it here. When we find a clause that contains Vars
2578 : * outside its syntactic scope, locate the nearest parent join level that
2579 : * includes all the required rels and add the clause to that level's
2580 : * lateral_clauses list. We'll process it when we reach that join level.
2581 : */
2582 589594 : if (!bms_is_subset(relids, qualscope))
2583 : {
2584 : JoinTreeItem *pitem;
2585 :
2586 : Assert(root->hasLateralRTEs); /* shouldn't happen otherwise */
2587 : Assert(sjinfo == NULL); /* mustn't postpone past outer join */
2588 116 : for (pitem = jtitem->jti_parent; pitem; pitem = pitem->jti_parent)
2589 : {
2590 116 : if (bms_is_subset(relids, pitem->qualscope))
2591 : {
2592 110 : pitem->lateral_clauses = lappend(pitem->lateral_clauses,
2593 : clause);
2594 415842 : return;
2595 : }
2596 :
2597 : /*
2598 : * We should not be postponing any quals past an outer join. If
2599 : * this Assert fires, pull_up_subqueries() messed up.
2600 : */
2601 : Assert(pitem->sjinfo == NULL);
2602 : }
2603 0 : elog(ERROR, "failed to postpone qual containing lateral reference");
2604 : }
2605 :
2606 : /*
2607 : * If it's an outer-join clause, also check that relids is a subset of
2608 : * ojscope. (This should not fail if the syntactic scope check passed.)
2609 : */
2610 589484 : if (ojscope && !bms_is_subset(relids, ojscope))
2611 0 : elog(ERROR, "JOIN qualification cannot refer to other relations");
2612 :
2613 : /*
2614 : * If the clause is variable-free, our normal heuristic for pushing it
2615 : * down to just the mentioned rels doesn't work, because there are none.
2616 : *
2617 : * If the clause is an outer-join clause, we must force it to the OJ's
2618 : * semantic level to preserve semantics.
2619 : *
2620 : * Otherwise, when the clause contains volatile functions, we force it to
2621 : * be evaluated at its original syntactic level. This preserves the
2622 : * expected semantics.
2623 : *
2624 : * When the clause contains no volatile functions either, it is actually a
2625 : * pseudoconstant clause that will not change value during any one
2626 : * execution of the plan, and hence can be used as a one-time qual in a
2627 : * gating Result plan node. We put such a clause into the regular
2628 : * RestrictInfo lists for the moment, but eventually createplan.c will
2629 : * pull it out and make a gating Result node immediately above whatever
2630 : * plan node the pseudoconstant clause is assigned to. It's usually best
2631 : * to put a gating node as high in the plan tree as possible.
2632 : */
2633 589484 : if (bms_is_empty(relids))
2634 : {
2635 10904 : if (ojscope)
2636 : {
2637 : /* clause is attached to outer join, eval it there */
2638 392 : relids = bms_copy(ojscope);
2639 : /* mustn't use as gating qual, so don't mark pseudoconstant */
2640 : }
2641 10512 : else if (contain_volatile_functions(clause))
2642 : {
2643 : /* eval at original syntactic level */
2644 174 : relids = bms_copy(qualscope);
2645 : /* again, can't mark pseudoconstant */
2646 : }
2647 : else
2648 : {
2649 : /*
2650 : * If we are in the top-level join domain, we can push the qual to
2651 : * the top of the plan tree. Otherwise, be conservative and eval
2652 : * it at original syntactic level. (Ideally we'd push it to the
2653 : * top of the current join domain in all cases, but that causes
2654 : * problems if we later rearrange outer-join evaluation order.
2655 : * Pseudoconstant quals below the top level are a pretty odd case,
2656 : * so it's not clear that it's worth working hard on.)
2657 : */
2658 10338 : if (jtitem->jdomain == (JoinDomain *) linitial(root->join_domains))
2659 10278 : relids = bms_copy(jtitem->jdomain->jd_relids);
2660 : else
2661 60 : relids = bms_copy(qualscope);
2662 : /* mark as gating qual */
2663 10338 : pseudoconstant = true;
2664 : /* tell createplan.c to check for gating quals */
2665 10338 : root->hasPseudoConstantQuals = true;
2666 : }
2667 : }
2668 :
2669 : /*----------
2670 : * Check to see if clause application must be delayed by outer-join
2671 : * considerations.
2672 : *
2673 : * A word about is_pushed_down: we mark the qual as "pushed down" if
2674 : * it is (potentially) applicable at a level different from its original
2675 : * syntactic level. This flag is used to distinguish OUTER JOIN ON quals
2676 : * from other quals pushed down to the same joinrel. The rules are:
2677 : * WHERE quals and INNER JOIN quals: is_pushed_down = true.
2678 : * Non-degenerate OUTER JOIN quals: is_pushed_down = false.
2679 : * Degenerate OUTER JOIN quals: is_pushed_down = true.
2680 : * A "degenerate" OUTER JOIN qual is one that doesn't mention the
2681 : * non-nullable side, and hence can be pushed down into the nullable side
2682 : * without changing the join result. It is correct to treat it as a
2683 : * regular filter condition at the level where it is evaluated.
2684 : *
2685 : * Note: it is not immediately obvious that a simple boolean is enough
2686 : * for this: if for some reason we were to attach a degenerate qual to
2687 : * its original join level, it would need to be treated as an outer join
2688 : * qual there. However, this cannot happen, because all the rels the
2689 : * clause mentions must be in the outer join's min_righthand, therefore
2690 : * the join it needs must be formed before the outer join; and we always
2691 : * attach quals to the lowest level where they can be evaluated. But
2692 : * if we were ever to re-introduce a mechanism for delaying evaluation
2693 : * of "expensive" quals, this area would need work.
2694 : *
2695 : * Note: generally, use of is_pushed_down has to go through the macro
2696 : * RINFO_IS_PUSHED_DOWN, because that flag alone is not always sufficient
2697 : * to tell whether a clause must be treated as pushed-down in context.
2698 : * This seems like another reason why it should perhaps be rethought.
2699 : *----------
2700 : */
2701 589484 : if (bms_overlap(relids, outerjoin_nonnullable))
2702 : {
2703 : /*
2704 : * The qual is attached to an outer join and mentions (some of the)
2705 : * rels on the nonnullable side, so it's not degenerate. If the
2706 : * caller wants to postpone handling such clauses, just add it to
2707 : * postponed_oj_qual_list and return. (The work we've done up to here
2708 : * will have to be redone later, but there's not much of it.)
2709 : */
2710 107702 : if (postponed_oj_qual_list != NULL)
2711 : {
2712 48018 : *postponed_oj_qual_list = lappend(*postponed_oj_qual_list, clause);
2713 48018 : return;
2714 : }
2715 :
2716 : /*
2717 : * We can't use such a clause to deduce equivalence (the left and
2718 : * right sides might be unequal above the join because one of them has
2719 : * gone to NULL) ... but we might be able to use it for more limited
2720 : * deductions, if it is mergejoinable. So consider adding it to the
2721 : * lists of set-aside outer-join clauses.
2722 : */
2723 59684 : is_pushed_down = false;
2724 59684 : maybe_equivalence = false;
2725 59684 : maybe_outer_join = true;
2726 :
2727 : /*
2728 : * Now force the qual to be evaluated exactly at the level of joining
2729 : * corresponding to the outer join. We cannot let it get pushed down
2730 : * into the nonnullable side, since then we'd produce no output rows,
2731 : * rather than the intended single null-extended row, for any
2732 : * nonnullable-side rows failing the qual.
2733 : */
2734 : Assert(ojscope);
2735 59684 : relids = ojscope;
2736 : Assert(!pseudoconstant);
2737 : }
2738 : else
2739 : {
2740 : /*
2741 : * Normal qual clause or degenerate outer-join clause. Either way, we
2742 : * can mark it as pushed-down.
2743 : */
2744 481782 : is_pushed_down = true;
2745 :
2746 : /*
2747 : * It's possible that this is an IS NULL clause that's redundant with
2748 : * a lower antijoin; if so we can just discard it. We need not test
2749 : * in any of the other cases, because this will only be possible for
2750 : * pushed-down clauses.
2751 : */
2752 481782 : if (check_redundant_nullability_qual(root, clause))
2753 1180 : return;
2754 :
2755 : /* Feed qual to the equivalence machinery, if allowed by caller */
2756 480602 : maybe_equivalence = allow_equivalence;
2757 :
2758 : /*
2759 : * Since it doesn't mention the LHS, it's certainly not useful as a
2760 : * set-aside OJ clause, even if it's in an OJ.
2761 : */
2762 480602 : maybe_outer_join = false;
2763 : }
2764 :
2765 : /*
2766 : * Build the RestrictInfo node itself.
2767 : */
2768 540286 : restrictinfo = make_restrictinfo(root,
2769 : (Expr *) clause,
2770 : is_pushed_down,
2771 : has_clone,
2772 : is_clone,
2773 : pseudoconstant,
2774 : security_level,
2775 : relids,
2776 : incompatible_relids,
2777 : outerjoin_nonnullable);
2778 :
2779 : /*
2780 : * If it's a join clause, add vars used in the clause to targetlists of
2781 : * their relations, so that they will be emitted by the plan nodes that
2782 : * scan those relations (else they won't be available at the join node!).
2783 : *
2784 : * Normally we mark the vars as needed at the join identified by "relids".
2785 : * However, if this is a clone clause then ignore the outer-join relids in
2786 : * that set. Otherwise, vars appearing in a cloned clause would end up
2787 : * marked as having to propagate to the highest one of the commuting
2788 : * joins, which would often be an overestimate. For such clauses, correct
2789 : * var propagation is ensured by making ojscope include input rels from
2790 : * both sides of the join.
2791 : *
2792 : * See also rebuild_joinclause_attr_needed, which has to partially repeat
2793 : * this work after removal of an outer join.
2794 : *
2795 : * Note: if the clause gets absorbed into an EquivalenceClass then this
2796 : * may be unnecessary, but for now we have to do it to cover the case
2797 : * where the EC becomes ec_broken and we end up reinserting the original
2798 : * clauses into the plan.
2799 : */
2800 540286 : if (bms_membership(relids) == BMS_MULTIPLE)
2801 : {
2802 155690 : List *vars = pull_var_clause(clause,
2803 : PVC_RECURSE_AGGREGATES |
2804 : PVC_RECURSE_WINDOWFUNCS |
2805 : PVC_INCLUDE_PLACEHOLDERS);
2806 : Relids where_needed;
2807 :
2808 155690 : if (is_clone)
2809 4738 : where_needed = bms_intersect(relids, root->all_baserels);
2810 : else
2811 150952 : where_needed = relids;
2812 155690 : add_vars_to_targetlist(root, vars, where_needed);
2813 155690 : list_free(vars);
2814 : }
2815 :
2816 : /*
2817 : * We check "mergejoinability" of every clause, not only join clauses,
2818 : * because we want to know about equivalences between vars of the same
2819 : * relation, or between vars and consts.
2820 : */
2821 540286 : check_mergejoinable(restrictinfo);
2822 :
2823 : /*
2824 : * If it is a true equivalence clause, send it to the EquivalenceClass
2825 : * machinery. We do *not* attach it directly to any restriction or join
2826 : * lists. The EC code will propagate it to the appropriate places later.
2827 : *
2828 : * If the clause has a mergejoinable operator, yet isn't an equivalence
2829 : * because it is an outer-join clause, the EC code may still be able to do
2830 : * something with it. We add it to appropriate lists for further
2831 : * consideration later. Specifically:
2832 : *
2833 : * If it is a left or right outer-join qualification that relates the two
2834 : * sides of the outer join (no funny business like leftvar1 = leftvar2 +
2835 : * rightvar), we add it to root->left_join_clauses or
2836 : * root->right_join_clauses according to which side the nonnullable
2837 : * variable appears on.
2838 : *
2839 : * If it is a full outer-join qualification, we add it to
2840 : * root->full_join_clauses. (Ideally we'd discard cases that aren't
2841 : * leftvar = rightvar, as we do for left/right joins, but this routine
2842 : * doesn't have the info needed to do that; and the current usage of the
2843 : * full_join_clauses list doesn't require that, so it's not currently
2844 : * worth complicating this routine's API to make it possible.)
2845 : *
2846 : * If none of the above hold, pass it off to
2847 : * distribute_restrictinfo_to_rels().
2848 : *
2849 : * In all cases, it's important to initialize the left_ec and right_ec
2850 : * fields of a mergejoinable clause, so that all possibly mergejoinable
2851 : * expressions have representations in EquivalenceClasses. If
2852 : * process_equivalence is successful, it will take care of that;
2853 : * otherwise, we have to call initialize_mergeclause_eclasses to do it.
2854 : */
2855 540286 : if (restrictinfo->mergeopfamilies)
2856 : {
2857 367794 : if (maybe_equivalence)
2858 : {
2859 309666 : if (process_equivalence(root, &restrictinfo, jtitem->jdomain))
2860 309404 : return;
2861 : /* EC rejected it, so set left_ec/right_ec the hard way ... */
2862 262 : if (restrictinfo->mergeopfamilies) /* EC might have changed this */
2863 208 : initialize_mergeclause_eclasses(root, restrictinfo);
2864 : /* ... and fall through to distribute_restrictinfo_to_rels */
2865 : }
2866 58128 : else if (maybe_outer_join && restrictinfo->can_join)
2867 : {
2868 : /* we need to set up left_ec/right_ec the hard way */
2869 57326 : initialize_mergeclause_eclasses(root, restrictinfo);
2870 : /* now see if it should go to any outer-join lists */
2871 : Assert(sjinfo != NULL);
2872 57326 : if (bms_is_subset(restrictinfo->left_relids,
2873 29164 : outerjoin_nonnullable) &&
2874 29164 : !bms_overlap(restrictinfo->right_relids,
2875 : outerjoin_nonnullable))
2876 : {
2877 : /* we have outervar = innervar */
2878 27882 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
2879 :
2880 27882 : ojcinfo->rinfo = restrictinfo;
2881 27882 : ojcinfo->sjinfo = sjinfo;
2882 27882 : root->left_join_clauses = lappend(root->left_join_clauses,
2883 : ojcinfo);
2884 27882 : return;
2885 : }
2886 29444 : if (bms_is_subset(restrictinfo->right_relids,
2887 29284 : outerjoin_nonnullable) &&
2888 29284 : !bms_overlap(restrictinfo->left_relids,
2889 : outerjoin_nonnullable))
2890 : {
2891 : /* we have innervar = outervar */
2892 28002 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
2893 :
2894 28002 : ojcinfo->rinfo = restrictinfo;
2895 28002 : ojcinfo->sjinfo = sjinfo;
2896 28002 : root->right_join_clauses = lappend(root->right_join_clauses,
2897 : ojcinfo);
2898 28002 : return;
2899 : }
2900 1442 : if (sjinfo->jointype == JOIN_FULL)
2901 : {
2902 : /* FULL JOIN (above tests cannot match in this case) */
2903 1246 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
2904 :
2905 1246 : ojcinfo->rinfo = restrictinfo;
2906 1246 : ojcinfo->sjinfo = sjinfo;
2907 1246 : root->full_join_clauses = lappend(root->full_join_clauses,
2908 : ojcinfo);
2909 1246 : return;
2910 : }
2911 : /* nope, so fall through to distribute_restrictinfo_to_rels */
2912 : }
2913 : else
2914 : {
2915 : /* we still need to set up left_ec/right_ec */
2916 802 : initialize_mergeclause_eclasses(root, restrictinfo);
2917 : }
2918 : }
2919 :
2920 : /* No EC special case applies, so push it into the clause lists */
2921 173752 : distribute_restrictinfo_to_rels(root, restrictinfo);
2922 : }
2923 :
2924 : /*
2925 : * check_redundant_nullability_qual
2926 : * Check to see if the qual is an IS NULL qual that is redundant with
2927 : * a lower JOIN_ANTI join.
2928 : *
2929 : * We want to suppress redundant IS NULL quals, not so much to save cycles
2930 : * as to avoid generating bogus selectivity estimates for them. So if
2931 : * redundancy is detected here, distribute_qual_to_rels() just throws away
2932 : * the qual.
2933 : */
2934 : static bool
2935 481782 : check_redundant_nullability_qual(PlannerInfo *root, Node *clause)
2936 : {
2937 : Var *forced_null_var;
2938 : ListCell *lc;
2939 :
2940 : /* Check for IS NULL, and identify the Var forced to NULL */
2941 481782 : forced_null_var = find_forced_null_var(clause);
2942 481782 : if (forced_null_var == NULL)
2943 479036 : return false;
2944 :
2945 : /*
2946 : * If the Var comes from the nullable side of a lower antijoin, the IS
2947 : * NULL condition is necessarily true. If it's not nulled by anything,
2948 : * there is no point in searching the join_info_list. Otherwise, we need
2949 : * to find out whether the nulling rel is an antijoin.
2950 : */
2951 2746 : if (forced_null_var->varnullingrels == NULL)
2952 1454 : return false;
2953 :
2954 1448 : foreach(lc, root->join_info_list)
2955 : {
2956 1336 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
2957 :
2958 : /*
2959 : * This test will not succeed if sjinfo->ojrelid is zero, which is
2960 : * possible for an antijoin that was converted from a semijoin; but in
2961 : * such a case the Var couldn't have come from its nullable side.
2962 : */
2963 2516 : if (sjinfo->jointype == JOIN_ANTI && sjinfo->ojrelid != 0 &&
2964 1180 : bms_is_member(sjinfo->ojrelid, forced_null_var->varnullingrels))
2965 1180 : return true;
2966 : }
2967 :
2968 112 : return false;
2969 : }
2970 :
2971 : /*
2972 : * add_base_clause_to_rel
2973 : * Add 'restrictinfo' as a baserestrictinfo to the base relation denoted
2974 : * by 'relid'. We offer some simple prechecks to try to determine if the
2975 : * qual is always true, in which case we ignore it rather than add it.
2976 : * If we detect the qual is always false, we replace it with
2977 : * constant-FALSE.
2978 : */
2979 : static void
2980 402822 : add_base_clause_to_rel(PlannerInfo *root, Index relid,
2981 : RestrictInfo *restrictinfo)
2982 : {
2983 402822 : RelOptInfo *rel = find_base_rel(root, relid);
2984 402822 : RangeTblEntry *rte = root->simple_rte_array[relid];
2985 :
2986 : Assert(bms_membership(restrictinfo->required_relids) == BMS_SINGLETON);
2987 :
2988 : /*
2989 : * For inheritance parent tables, we must always record the RestrictInfo
2990 : * in baserestrictinfo as is. If we were to transform or skip adding it,
2991 : * then the original wouldn't be available in apply_child_basequals. Since
2992 : * there are two RangeTblEntries for inheritance parents, one with
2993 : * inh==true and the other with inh==false, we're still able to apply this
2994 : * optimization to the inh==false one. The inh==true one is what
2995 : * apply_child_basequals() sees, whereas the inh==false one is what's used
2996 : * for the scan node in the final plan.
2997 : *
2998 : * We make an exception to this for partitioned tables. For these, we
2999 : * always apply the constant-TRUE and constant-FALSE transformations. A
3000 : * qual which is either of these for a partitioned table must also be that
3001 : * for all of its child partitions.
3002 : */
3003 402822 : if (!rte->inh || rte->relkind == RELKIND_PARTITIONED_TABLE)
3004 : {
3005 : /* Don't add the clause if it is always true */
3006 401062 : if (restriction_is_always_true(root, restrictinfo))
3007 670 : return;
3008 :
3009 : /*
3010 : * Substitute the origin qual with constant-FALSE if it is provably
3011 : * always false.
3012 : *
3013 : * Note that we need to keep the same rinfo_serial, since it is in
3014 : * practice the same condition. We also need to reset the
3015 : * last_rinfo_serial counter, which is essential to ensure that the
3016 : * RestrictInfos for the "same" qual condition get identical serial
3017 : * numbers (see deconstruct_distribute_oj_quals).
3018 : */
3019 400392 : if (restriction_is_always_false(root, restrictinfo))
3020 : {
3021 34 : int save_rinfo_serial = restrictinfo->rinfo_serial;
3022 34 : int save_last_rinfo_serial = root->last_rinfo_serial;
3023 :
3024 34 : restrictinfo = make_restrictinfo(root,
3025 34 : (Expr *) makeBoolConst(false, false),
3026 34 : restrictinfo->is_pushed_down,
3027 34 : restrictinfo->has_clone,
3028 34 : restrictinfo->is_clone,
3029 34 : restrictinfo->pseudoconstant,
3030 : 0, /* security_level */
3031 : restrictinfo->required_relids,
3032 : restrictinfo->incompatible_relids,
3033 : restrictinfo->outer_relids);
3034 34 : restrictinfo->rinfo_serial = save_rinfo_serial;
3035 34 : root->last_rinfo_serial = save_last_rinfo_serial;
3036 : }
3037 : }
3038 :
3039 : /* Add clause to rel's restriction list */
3040 402152 : rel->baserestrictinfo = lappend(rel->baserestrictinfo, restrictinfo);
3041 :
3042 : /* Update security level info */
3043 402152 : rel->baserestrict_min_security = Min(rel->baserestrict_min_security,
3044 : restrictinfo->security_level);
3045 : }
3046 :
3047 : /*
3048 : * expr_is_nonnullable
3049 : * Check to see if the Expr cannot be NULL
3050 : *
3051 : * If the Expr is a simple Var that is defined NOT NULL and meanwhile is not
3052 : * nulled by any outer joins, then we can know that it cannot be NULL.
3053 : */
3054 : static bool
3055 11168 : expr_is_nonnullable(PlannerInfo *root, Expr *expr)
3056 : {
3057 : RelOptInfo *rel;
3058 : Var *var;
3059 :
3060 : /* For now only check simple Vars */
3061 11168 : if (!IsA(expr, Var))
3062 616 : return false;
3063 :
3064 10552 : var = (Var *) expr;
3065 :
3066 : /* could the Var be nulled by any outer joins? */
3067 10552 : if (!bms_is_empty(var->varnullingrels))
3068 912 : return false;
3069 :
3070 : /* system columns cannot be NULL */
3071 9640 : if (var->varattno < 0)
3072 24 : return true;
3073 :
3074 : /* is the column defined NOT NULL? */
3075 9616 : rel = find_base_rel(root, var->varno);
3076 19220 : if (var->varattno > 0 &&
3077 9604 : bms_is_member(var->varattno, rel->notnullattnums))
3078 758 : return true;
3079 :
3080 8858 : return false;
3081 : }
3082 :
3083 : /*
3084 : * restriction_is_always_true
3085 : * Check to see if the RestrictInfo is always true.
3086 : *
3087 : * Currently we only check for NullTest quals and OR clauses that include
3088 : * NullTest quals. We may extend it in the future.
3089 : */
3090 : bool
3091 521558 : restriction_is_always_true(PlannerInfo *root,
3092 : RestrictInfo *restrictinfo)
3093 : {
3094 : /*
3095 : * For a clone clause, we don't have a reliable way to determine if the
3096 : * input expression of a NullTest is non-nullable: nullingrel bits in
3097 : * clone clauses may not reflect reality, so we dare not draw conclusions
3098 : * from clones about whether Vars are guaranteed not-null.
3099 : */
3100 521558 : if (restrictinfo->has_clone || restrictinfo->is_clone)
3101 9440 : return false;
3102 :
3103 : /* Check for NullTest qual */
3104 512118 : if (IsA(restrictinfo->clause, NullTest))
3105 : {
3106 11870 : NullTest *nulltest = (NullTest *) restrictinfo->clause;
3107 :
3108 : /* is this NullTest an IS_NOT_NULL qual? */
3109 11870 : if (nulltest->nulltesttype != IS_NOT_NULL)
3110 3146 : return false;
3111 :
3112 : /*
3113 : * Empty rows can appear NULL in some contexts and NOT NULL in others,
3114 : * so avoid this optimization for row expressions.
3115 : */
3116 8724 : if (nulltest->argisrow)
3117 156 : return false;
3118 :
3119 8568 : return expr_is_nonnullable(root, nulltest->arg);
3120 : }
3121 :
3122 : /* If it's an OR, check its sub-clauses */
3123 500248 : if (restriction_is_or_clause(restrictinfo))
3124 : {
3125 : ListCell *lc;
3126 :
3127 : Assert(is_orclause(restrictinfo->orclause));
3128 :
3129 : /*
3130 : * if any of the given OR branches is provably always true then the
3131 : * entire condition is true.
3132 : */
3133 33794 : foreach(lc, ((BoolExpr *) restrictinfo->orclause)->args)
3134 : {
3135 23640 : Node *orarg = (Node *) lfirst(lc);
3136 :
3137 23640 : if (!IsA(orarg, RestrictInfo))
3138 3150 : continue;
3139 :
3140 20490 : if (restriction_is_always_true(root, (RestrictInfo *) orarg))
3141 12 : return true;
3142 : }
3143 : }
3144 :
3145 500236 : return false;
3146 : }
3147 :
3148 : /*
3149 : * restriction_is_always_false
3150 : * Check to see if the RestrictInfo is always false.
3151 : *
3152 : * Currently we only check for NullTest quals and OR clauses that include
3153 : * NullTest quals. We may extend it in the future.
3154 : */
3155 : bool
3156 509066 : restriction_is_always_false(PlannerInfo *root,
3157 : RestrictInfo *restrictinfo)
3158 : {
3159 : /*
3160 : * For a clone clause, we don't have a reliable way to determine if the
3161 : * input expression of a NullTest is non-nullable: nullingrel bits in
3162 : * clone clauses may not reflect reality, so we dare not draw conclusions
3163 : * from clones about whether Vars are guaranteed not-null.
3164 : */
3165 509066 : if (restrictinfo->has_clone || restrictinfo->is_clone)
3166 9440 : return false;
3167 :
3168 : /* Check for NullTest qual */
3169 499626 : if (IsA(restrictinfo->clause, NullTest))
3170 : {
3171 9908 : NullTest *nulltest = (NullTest *) restrictinfo->clause;
3172 :
3173 : /* is this NullTest an IS_NULL qual? */
3174 9908 : if (nulltest->nulltesttype != IS_NULL)
3175 7188 : return false;
3176 :
3177 : /*
3178 : * Empty rows can appear NULL in some contexts and NOT NULL in others,
3179 : * so avoid this optimization for row expressions.
3180 : */
3181 2720 : if (nulltest->argisrow)
3182 120 : return false;
3183 :
3184 2600 : return expr_is_nonnullable(root, nulltest->arg);
3185 : }
3186 :
3187 : /* If it's an OR, check its sub-clauses */
3188 489718 : if (restriction_is_or_clause(restrictinfo))
3189 : {
3190 : ListCell *lc;
3191 :
3192 : Assert(is_orclause(restrictinfo->orclause));
3193 :
3194 : /*
3195 : * Currently, when processing OR expressions, we only return true when
3196 : * all of the OR branches are always false. This could perhaps be
3197 : * expanded to remove OR branches that are provably false. This may
3198 : * be a useful thing to do as it could result in the OR being left
3199 : * with a single arg. That's useful as it would allow the OR
3200 : * condition to be replaced with its single argument which may allow
3201 : * use of an index for faster filtering on the remaining condition.
3202 : */
3203 10196 : foreach(lc, ((BoolExpr *) restrictinfo->orclause)->args)
3204 : {
3205 10184 : Node *orarg = (Node *) lfirst(lc);
3206 :
3207 10184 : if (!IsA(orarg, RestrictInfo) ||
3208 8668 : !restriction_is_always_false(root, (RestrictInfo *) orarg))
3209 10142 : return false;
3210 : }
3211 12 : return true;
3212 : }
3213 :
3214 479564 : return false;
3215 : }
3216 :
3217 : /*
3218 : * distribute_restrictinfo_to_rels
3219 : * Push a completed RestrictInfo into the proper restriction or join
3220 : * clause list(s).
3221 : *
3222 : * This is the last step of distribute_qual_to_rels() for ordinary qual
3223 : * clauses. Clauses that are interesting for equivalence-class processing
3224 : * are diverted to the EC machinery, but may ultimately get fed back here.
3225 : */
3226 : void
3227 474508 : distribute_restrictinfo_to_rels(PlannerInfo *root,
3228 : RestrictInfo *restrictinfo)
3229 : {
3230 474508 : Relids relids = restrictinfo->required_relids;
3231 :
3232 474508 : if (!bms_is_empty(relids))
3233 : {
3234 : int relid;
3235 :
3236 474508 : if (bms_get_singleton_member(relids, &relid))
3237 : {
3238 : /*
3239 : * There is only one relation participating in the clause, so it
3240 : * is a restriction clause for that relation.
3241 : */
3242 402822 : add_base_clause_to_rel(root, relid, restrictinfo);
3243 : }
3244 : else
3245 : {
3246 : /*
3247 : * The clause is a join clause, since there is more than one rel
3248 : * in its relid set.
3249 : */
3250 :
3251 : /*
3252 : * Check for hashjoinable operators. (We don't bother setting the
3253 : * hashjoin info except in true join clauses.)
3254 : */
3255 71686 : check_hashjoinable(restrictinfo);
3256 :
3257 : /*
3258 : * Likewise, check if the clause is suitable to be used with a
3259 : * Memoize node to cache inner tuples during a parameterized
3260 : * nested loop.
3261 : */
3262 71686 : check_memoizable(restrictinfo);
3263 :
3264 : /*
3265 : * Add clause to the join lists of all the relevant relations.
3266 : */
3267 71686 : add_join_clause_to_rels(root, restrictinfo, relids);
3268 : }
3269 : }
3270 : else
3271 : {
3272 : /*
3273 : * clause references no rels, and therefore we have no place to attach
3274 : * it. Shouldn't get here if callers are working properly.
3275 : */
3276 0 : elog(ERROR, "cannot cope with variable-free clause");
3277 : }
3278 474508 : }
3279 :
3280 : /*
3281 : * process_implied_equality
3282 : * Create a restrictinfo item that says "item1 op item2", and push it
3283 : * into the appropriate lists. (In practice opno is always a btree
3284 : * equality operator.)
3285 : *
3286 : * "qualscope" is the nominal syntactic level to impute to the restrictinfo.
3287 : * This must contain at least all the rels used in the expressions, but it
3288 : * is used only to set the qual application level when both exprs are
3289 : * variable-free. (Hence, it should usually match the join domain in which
3290 : * the clause applies.) Otherwise the qual is applied at the lowest join
3291 : * level that provides all its variables.
3292 : *
3293 : * "security_level" is the security level to assign to the new restrictinfo.
3294 : *
3295 : * "both_const" indicates whether both items are known pseudo-constant;
3296 : * in this case it is worth applying eval_const_expressions() in case we
3297 : * can produce constant TRUE or constant FALSE. (Otherwise it's not,
3298 : * because the expressions went through eval_const_expressions already.)
3299 : *
3300 : * Returns the generated RestrictInfo, if any. The result will be NULL
3301 : * if both_const is true and we successfully reduced the clause to
3302 : * constant TRUE.
3303 : *
3304 : * Note: this function will copy item1 and item2, but it is caller's
3305 : * responsibility to make sure that the Relids parameters are fresh copies
3306 : * not shared with other uses.
3307 : *
3308 : * Note: we do not do initialize_mergeclause_eclasses() here. It is
3309 : * caller's responsibility that left_ec/right_ec be set as necessary.
3310 : */
3311 : RestrictInfo *
3312 37734 : process_implied_equality(PlannerInfo *root,
3313 : Oid opno,
3314 : Oid collation,
3315 : Expr *item1,
3316 : Expr *item2,
3317 : Relids qualscope,
3318 : Index security_level,
3319 : bool both_const)
3320 : {
3321 : RestrictInfo *restrictinfo;
3322 : Node *clause;
3323 : Relids relids;
3324 37734 : bool pseudoconstant = false;
3325 :
3326 : /*
3327 : * Build the new clause. Copy to ensure it shares no substructure with
3328 : * original (this is necessary in case there are subselects in there...)
3329 : */
3330 37734 : clause = (Node *) make_opclause(opno,
3331 : BOOLOID, /* opresulttype */
3332 : false, /* opretset */
3333 37734 : copyObject(item1),
3334 37734 : copyObject(item2),
3335 : InvalidOid,
3336 : collation);
3337 :
3338 : /* If both constant, try to reduce to a boolean constant. */
3339 37734 : if (both_const)
3340 : {
3341 132 : clause = eval_const_expressions(root, clause);
3342 :
3343 : /* If we produced const TRUE, just drop the clause */
3344 132 : if (clause && IsA(clause, Const))
3345 : {
3346 126 : Const *cclause = (Const *) clause;
3347 :
3348 : Assert(cclause->consttype == BOOLOID);
3349 126 : if (!cclause->constisnull && DatumGetBool(cclause->constvalue))
3350 0 : return NULL;
3351 : }
3352 : }
3353 :
3354 : /*
3355 : * The rest of this is a very cut-down version of distribute_qual_to_rels.
3356 : * We can skip most of the work therein, but there are a couple of special
3357 : * cases we still have to handle.
3358 : *
3359 : * Retrieve all relids mentioned within the possibly-simplified clause.
3360 : */
3361 37734 : relids = pull_varnos(root, clause);
3362 : Assert(bms_is_subset(relids, qualscope));
3363 :
3364 : /*
3365 : * If the clause is variable-free, our normal heuristic for pushing it
3366 : * down to just the mentioned rels doesn't work, because there are none.
3367 : * Apply it as a gating qual at the appropriate level (see comments for
3368 : * get_join_domain_min_rels).
3369 : */
3370 37734 : if (bms_is_empty(relids))
3371 : {
3372 : /* eval at join domain's safe level */
3373 132 : relids = get_join_domain_min_rels(root, qualscope);
3374 : /* mark as gating qual */
3375 132 : pseudoconstant = true;
3376 : /* tell createplan.c to check for gating quals */
3377 132 : root->hasPseudoConstantQuals = true;
3378 : }
3379 :
3380 : /*
3381 : * Build the RestrictInfo node itself.
3382 : */
3383 37734 : restrictinfo = make_restrictinfo(root,
3384 : (Expr *) clause,
3385 : true, /* is_pushed_down */
3386 : false, /* !has_clone */
3387 : false, /* !is_clone */
3388 : pseudoconstant,
3389 : security_level,
3390 : relids,
3391 : NULL, /* incompatible_relids */
3392 : NULL); /* outer_relids */
3393 :
3394 : /*
3395 : * If it's a join clause, add vars used in the clause to targetlists of
3396 : * their relations, so that they will be emitted by the plan nodes that
3397 : * scan those relations (else they won't be available at the join node!).
3398 : *
3399 : * Typically, we'd have already done this when the component expressions
3400 : * were first seen by distribute_qual_to_rels; but it is possible that
3401 : * some of the Vars could have missed having that done because they only
3402 : * appeared in single-relation clauses originally. So do it here for
3403 : * safety.
3404 : *
3405 : * See also rebuild_joinclause_attr_needed, which has to partially repeat
3406 : * this work after removal of an outer join. (Since we will put this
3407 : * clause into the joininfo lists, that function needn't do any extra work
3408 : * to find it.)
3409 : */
3410 37734 : if (bms_membership(relids) == BMS_MULTIPLE)
3411 : {
3412 60 : List *vars = pull_var_clause(clause,
3413 : PVC_RECURSE_AGGREGATES |
3414 : PVC_RECURSE_WINDOWFUNCS |
3415 : PVC_INCLUDE_PLACEHOLDERS);
3416 :
3417 60 : add_vars_to_targetlist(root, vars, relids);
3418 60 : list_free(vars);
3419 : }
3420 :
3421 : /*
3422 : * Check mergejoinability. This will usually succeed, since the op came
3423 : * from an EquivalenceClass; but we could have reduced the original clause
3424 : * to a constant.
3425 : */
3426 37734 : check_mergejoinable(restrictinfo);
3427 :
3428 : /*
3429 : * Note we don't do initialize_mergeclause_eclasses(); the caller can
3430 : * handle that much more cheaply than we can. It's okay to call
3431 : * distribute_restrictinfo_to_rels() before that happens.
3432 : */
3433 :
3434 : /*
3435 : * Push the new clause into all the appropriate restrictinfo lists.
3436 : */
3437 37734 : distribute_restrictinfo_to_rels(root, restrictinfo);
3438 :
3439 37734 : return restrictinfo;
3440 : }
3441 :
3442 : /*
3443 : * build_implied_join_equality --- build a RestrictInfo for a derived equality
3444 : *
3445 : * This overlaps the functionality of process_implied_equality(), but we
3446 : * must not push the RestrictInfo into the joininfo tree.
3447 : *
3448 : * Note: this function will copy item1 and item2, but it is caller's
3449 : * responsibility to make sure that the Relids parameters are fresh copies
3450 : * not shared with other uses.
3451 : *
3452 : * Note: we do not do initialize_mergeclause_eclasses() here. It is
3453 : * caller's responsibility that left_ec/right_ec be set as necessary.
3454 : */
3455 : RestrictInfo *
3456 77142 : build_implied_join_equality(PlannerInfo *root,
3457 : Oid opno,
3458 : Oid collation,
3459 : Expr *item1,
3460 : Expr *item2,
3461 : Relids qualscope,
3462 : Index security_level)
3463 : {
3464 : RestrictInfo *restrictinfo;
3465 : Expr *clause;
3466 :
3467 : /*
3468 : * Build the new clause. Copy to ensure it shares no substructure with
3469 : * original (this is necessary in case there are subselects in there...)
3470 : */
3471 77142 : clause = make_opclause(opno,
3472 : BOOLOID, /* opresulttype */
3473 : false, /* opretset */
3474 77142 : copyObject(item1),
3475 77142 : copyObject(item2),
3476 : InvalidOid,
3477 : collation);
3478 :
3479 : /*
3480 : * Build the RestrictInfo node itself.
3481 : */
3482 77142 : restrictinfo = make_restrictinfo(root,
3483 : clause,
3484 : true, /* is_pushed_down */
3485 : false, /* !has_clone */
3486 : false, /* !is_clone */
3487 : false, /* pseudoconstant */
3488 : security_level, /* security_level */
3489 : qualscope, /* required_relids */
3490 : NULL, /* incompatible_relids */
3491 : NULL); /* outer_relids */
3492 :
3493 : /* Set mergejoinability/hashjoinability flags */
3494 77142 : check_mergejoinable(restrictinfo);
3495 77142 : check_hashjoinable(restrictinfo);
3496 77142 : check_memoizable(restrictinfo);
3497 :
3498 77142 : return restrictinfo;
3499 : }
3500 :
3501 : /*
3502 : * get_join_domain_min_rels
3503 : * Identify the appropriate join level for derived quals belonging
3504 : * to the join domain with the given relids.
3505 : *
3506 : * When we derive a pseudoconstant (Var-free) clause from an EquivalenceClass,
3507 : * we'd ideally apply the clause at the top level of the EC's join domain.
3508 : * However, if there are any outer joins inside that domain that get commuted
3509 : * with joins outside it, that leads to not finding a correct place to apply
3510 : * the clause. Instead, remove any lower outer joins from the relid set,
3511 : * and apply the clause to just the remaining rels. This still results in a
3512 : * correct answer, since if the clause produces FALSE then the LHS of these
3513 : * joins will be empty leading to an empty join result.
3514 : *
3515 : * However, there's no need to remove outer joins if this is the top-level
3516 : * join domain of the query, since then there's nothing else to commute with.
3517 : *
3518 : * Note: it's tempting to use this in distribute_qual_to_rels where it's
3519 : * dealing with pseudoconstant quals; but we can't because the necessary
3520 : * SpecialJoinInfos aren't all formed at that point.
3521 : *
3522 : * The result is always freshly palloc'd; we do not modify domain_relids.
3523 : */
3524 : static Relids
3525 132 : get_join_domain_min_rels(PlannerInfo *root, Relids domain_relids)
3526 : {
3527 132 : Relids result = bms_copy(domain_relids);
3528 : ListCell *lc;
3529 :
3530 : /* Top-level join domain? */
3531 132 : if (bms_equal(result, root->all_query_rels))
3532 66 : return result;
3533 :
3534 : /* Nope, look for lower outer joins that could potentially commute out */
3535 138 : foreach(lc, root->join_info_list)
3536 : {
3537 72 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
3538 :
3539 144 : if (sjinfo->jointype == JOIN_LEFT &&
3540 72 : bms_is_member(sjinfo->ojrelid, result))
3541 : {
3542 6 : result = bms_del_member(result, sjinfo->ojrelid);
3543 6 : result = bms_del_members(result, sjinfo->syn_righthand);
3544 : }
3545 : }
3546 66 : return result;
3547 : }
3548 :
3549 :
3550 : /*
3551 : * rebuild_joinclause_attr_needed
3552 : * Put back attr_needed bits for Vars/PHVs needed for join clauses.
3553 : *
3554 : * This is used to rebuild attr_needed/ph_needed sets after removal of a
3555 : * useless outer join. It should match what distribute_qual_to_rels did,
3556 : * except that we call add_vars_to_attr_needed not add_vars_to_targetlist.
3557 : */
3558 : void
3559 11550 : rebuild_joinclause_attr_needed(PlannerInfo *root)
3560 : {
3561 : /*
3562 : * We must examine all join clauses, but there's no value in processing
3563 : * any join clause more than once. So it's slightly annoying that we have
3564 : * to find them via the per-base-relation joininfo lists. Avoid duplicate
3565 : * processing by tracking the rinfo_serial numbers of join clauses we've
3566 : * already seen. (This doesn't work for is_clone clauses, so we must
3567 : * waste effort on them.)
3568 : */
3569 11550 : Bitmapset *seen_serials = NULL;
3570 : Index rti;
3571 :
3572 : /* Scan all baserels for join clauses */
3573 71978 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
3574 : {
3575 60428 : RelOptInfo *brel = root->simple_rel_array[rti];
3576 : ListCell *lc;
3577 :
3578 60428 : if (brel == NULL)
3579 40990 : continue;
3580 19438 : if (brel->reloptkind != RELOPT_BASEREL)
3581 0 : continue;
3582 :
3583 28742 : foreach(lc, brel->joininfo)
3584 : {
3585 9304 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3586 9304 : Relids relids = rinfo->required_relids;
3587 :
3588 9304 : if (!rinfo->is_clone) /* else serial number is not unique */
3589 : {
3590 9208 : if (bms_is_member(rinfo->rinfo_serial, seen_serials))
3591 4958 : continue; /* saw it already */
3592 4250 : seen_serials = bms_add_member(seen_serials,
3593 : rinfo->rinfo_serial);
3594 : }
3595 :
3596 4346 : if (bms_membership(relids) == BMS_MULTIPLE)
3597 : {
3598 4346 : List *vars = pull_var_clause((Node *) rinfo->clause,
3599 : PVC_RECURSE_AGGREGATES |
3600 : PVC_RECURSE_WINDOWFUNCS |
3601 : PVC_INCLUDE_PLACEHOLDERS);
3602 : Relids where_needed;
3603 :
3604 4346 : if (rinfo->is_clone)
3605 96 : where_needed = bms_intersect(relids, root->all_baserels);
3606 : else
3607 4250 : where_needed = relids;
3608 4346 : add_vars_to_attr_needed(root, vars, where_needed);
3609 4346 : list_free(vars);
3610 : }
3611 : }
3612 : }
3613 11550 : }
3614 :
3615 :
3616 : /*
3617 : * match_foreign_keys_to_quals
3618 : * Match foreign-key constraints to equivalence classes and join quals
3619 : *
3620 : * The idea here is to see which query join conditions match equality
3621 : * constraints of a foreign-key relationship. For such join conditions,
3622 : * we can use the FK semantics to make selectivity estimates that are more
3623 : * reliable than estimating from statistics, especially for multiple-column
3624 : * FKs, where the normal assumption of independent conditions tends to fail.
3625 : *
3626 : * In this function we annotate the ForeignKeyOptInfos in root->fkey_list
3627 : * with info about which eclasses and join qual clauses they match, and
3628 : * discard any ForeignKeyOptInfos that are irrelevant for the query.
3629 : */
3630 : void
3631 328968 : match_foreign_keys_to_quals(PlannerInfo *root)
3632 : {
3633 328968 : List *newlist = NIL;
3634 : ListCell *lc;
3635 :
3636 330804 : foreach(lc, root->fkey_list)
3637 : {
3638 1836 : ForeignKeyOptInfo *fkinfo = (ForeignKeyOptInfo *) lfirst(lc);
3639 : RelOptInfo *con_rel;
3640 : RelOptInfo *ref_rel;
3641 : int colno;
3642 :
3643 : /*
3644 : * Either relid might identify a rel that is in the query's rtable but
3645 : * isn't referenced by the jointree, or has been removed by join
3646 : * removal, so that it won't have a RelOptInfo. Hence don't use
3647 : * find_base_rel() here. We can ignore such FKs.
3648 : */
3649 1836 : if (fkinfo->con_relid >= root->simple_rel_array_size ||
3650 1836 : fkinfo->ref_relid >= root->simple_rel_array_size)
3651 0 : continue; /* just paranoia */
3652 1836 : con_rel = root->simple_rel_array[fkinfo->con_relid];
3653 1836 : if (con_rel == NULL)
3654 12 : continue;
3655 1824 : ref_rel = root->simple_rel_array[fkinfo->ref_relid];
3656 1824 : if (ref_rel == NULL)
3657 24 : continue;
3658 :
3659 : /*
3660 : * Ignore FK unless both rels are baserels. This gets rid of FKs that
3661 : * link to inheritance child rels (otherrels).
3662 : */
3663 1800 : if (con_rel->reloptkind != RELOPT_BASEREL ||
3664 1800 : ref_rel->reloptkind != RELOPT_BASEREL)
3665 0 : continue;
3666 :
3667 : /*
3668 : * Scan the columns and try to match them to eclasses and quals.
3669 : *
3670 : * Note: for simple inner joins, any match should be in an eclass.
3671 : * "Loose" quals that syntactically match an FK equality must have
3672 : * been rejected for EC status because they are outer-join quals or
3673 : * similar. We can still consider them to match the FK.
3674 : */
3675 4202 : for (colno = 0; colno < fkinfo->nkeys; colno++)
3676 : {
3677 : EquivalenceClass *ec;
3678 : AttrNumber con_attno,
3679 : ref_attno;
3680 : Oid fpeqop;
3681 : ListCell *lc2;
3682 :
3683 2402 : ec = match_eclasses_to_foreign_key_col(root, fkinfo, colno);
3684 : /* Don't bother looking for loose quals if we got an EC match */
3685 2402 : if (ec != NULL)
3686 : {
3687 342 : fkinfo->nmatched_ec++;
3688 342 : if (ec->ec_has_const)
3689 74 : fkinfo->nconst_ec++;
3690 342 : continue;
3691 : }
3692 :
3693 : /*
3694 : * Scan joininfo list for relevant clauses. Either rel's joininfo
3695 : * list would do equally well; we use con_rel's.
3696 : */
3697 2060 : con_attno = fkinfo->conkey[colno];
3698 2060 : ref_attno = fkinfo->confkey[colno];
3699 2060 : fpeqop = InvalidOid; /* we'll look this up only if needed */
3700 :
3701 5408 : foreach(lc2, con_rel->joininfo)
3702 : {
3703 3348 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc2);
3704 3348 : OpExpr *clause = (OpExpr *) rinfo->clause;
3705 : Var *leftvar;
3706 : Var *rightvar;
3707 :
3708 : /* Only binary OpExprs are useful for consideration */
3709 6696 : if (!IsA(clause, OpExpr) ||
3710 3348 : list_length(clause->args) != 2)
3711 0 : continue;
3712 3348 : leftvar = (Var *) get_leftop((Expr *) clause);
3713 3348 : rightvar = (Var *) get_rightop((Expr *) clause);
3714 :
3715 : /* Operands must be Vars, possibly with RelabelType */
3716 3594 : while (leftvar && IsA(leftvar, RelabelType))
3717 246 : leftvar = (Var *) ((RelabelType *) leftvar)->arg;
3718 3348 : if (!(leftvar && IsA(leftvar, Var)))
3719 0 : continue;
3720 3576 : while (rightvar && IsA(rightvar, RelabelType))
3721 228 : rightvar = (Var *) ((RelabelType *) rightvar)->arg;
3722 3348 : if (!(rightvar && IsA(rightvar, Var)))
3723 30 : continue;
3724 :
3725 : /* Now try to match the vars to the current foreign key cols */
3726 3318 : if (fkinfo->ref_relid == leftvar->varno &&
3727 3192 : ref_attno == leftvar->varattno &&
3728 1814 : fkinfo->con_relid == rightvar->varno &&
3729 1814 : con_attno == rightvar->varattno)
3730 : {
3731 : /* Vars match, but is it the right operator? */
3732 1736 : if (clause->opno == fkinfo->conpfeqop[colno])
3733 : {
3734 1736 : fkinfo->rinfos[colno] = lappend(fkinfo->rinfos[colno],
3735 : rinfo);
3736 1736 : fkinfo->nmatched_ri++;
3737 : }
3738 : }
3739 1582 : else if (fkinfo->ref_relid == rightvar->varno &&
3740 90 : ref_attno == rightvar->varattno &&
3741 36 : fkinfo->con_relid == leftvar->varno &&
3742 36 : con_attno == leftvar->varattno)
3743 : {
3744 : /*
3745 : * Reverse match, must check commutator operator. Look it
3746 : * up if we didn't already. (In the worst case we might
3747 : * do multiple lookups here, but that would require an FK
3748 : * equality operator without commutator, which is
3749 : * unlikely.)
3750 : */
3751 36 : if (!OidIsValid(fpeqop))
3752 36 : fpeqop = get_commutator(fkinfo->conpfeqop[colno]);
3753 36 : if (clause->opno == fpeqop)
3754 : {
3755 36 : fkinfo->rinfos[colno] = lappend(fkinfo->rinfos[colno],
3756 : rinfo);
3757 36 : fkinfo->nmatched_ri++;
3758 : }
3759 : }
3760 : }
3761 : /* If we found any matching loose quals, count col as matched */
3762 2060 : if (fkinfo->rinfos[colno])
3763 1772 : fkinfo->nmatched_rcols++;
3764 : }
3765 :
3766 : /*
3767 : * Currently, we drop multicolumn FKs that aren't fully matched to the
3768 : * query. Later we might figure out how to derive some sort of
3769 : * estimate from them, in which case this test should be weakened to
3770 : * "if ((fkinfo->nmatched_ec + fkinfo->nmatched_rcols) > 0)".
3771 : */
3772 1800 : if ((fkinfo->nmatched_ec + fkinfo->nmatched_rcols) == fkinfo->nkeys)
3773 1536 : newlist = lappend(newlist, fkinfo);
3774 : }
3775 : /* Replace fkey_list, thereby discarding any useless entries */
3776 328968 : root->fkey_list = newlist;
3777 328968 : }
3778 :
3779 :
3780 : /*****************************************************************************
3781 : *
3782 : * CHECKS FOR MERGEJOINABLE AND HASHJOINABLE CLAUSES
3783 : *
3784 : *****************************************************************************/
3785 :
3786 : /*
3787 : * check_mergejoinable
3788 : * If the restrictinfo's clause is mergejoinable, set the mergejoin
3789 : * info fields in the restrictinfo.
3790 : *
3791 : * Currently, we support mergejoin for binary opclauses where
3792 : * the operator is a mergejoinable operator. The arguments can be
3793 : * anything --- as long as there are no volatile functions in them.
3794 : */
3795 : static void
3796 655162 : check_mergejoinable(RestrictInfo *restrictinfo)
3797 : {
3798 655162 : Expr *clause = restrictinfo->clause;
3799 : Oid opno;
3800 : Node *leftarg;
3801 :
3802 655162 : if (restrictinfo->pseudoconstant)
3803 10470 : return;
3804 644692 : if (!is_opclause(clause))
3805 84066 : return;
3806 560626 : if (list_length(((OpExpr *) clause)->args) != 2)
3807 24 : return;
3808 :
3809 560602 : opno = ((OpExpr *) clause)->opno;
3810 560602 : leftarg = linitial(((OpExpr *) clause)->args);
3811 :
3812 560602 : if (op_mergejoinable(opno, exprType(leftarg)) &&
3813 482570 : !contain_volatile_functions((Node *) restrictinfo))
3814 482538 : restrictinfo->mergeopfamilies = get_mergejoin_opfamilies(opno);
3815 :
3816 : /*
3817 : * Note: op_mergejoinable is just a hint; if we fail to find the operator
3818 : * in any btree opfamilies, mergeopfamilies remains NIL and so the clause
3819 : * is not treated as mergejoinable.
3820 : */
3821 : }
3822 :
3823 : /*
3824 : * check_hashjoinable
3825 : * If the restrictinfo's clause is hashjoinable, set the hashjoin
3826 : * info fields in the restrictinfo.
3827 : *
3828 : * Currently, we support hashjoin for binary opclauses where
3829 : * the operator is a hashjoinable operator. The arguments can be
3830 : * anything --- as long as there are no volatile functions in them.
3831 : */
3832 : static void
3833 148828 : check_hashjoinable(RestrictInfo *restrictinfo)
3834 : {
3835 148828 : Expr *clause = restrictinfo->clause;
3836 : Oid opno;
3837 : Node *leftarg;
3838 :
3839 148828 : if (restrictinfo->pseudoconstant)
3840 3550 : return;
3841 145278 : if (!is_opclause(clause))
3842 8462 : return;
3843 136816 : if (list_length(((OpExpr *) clause)->args) != 2)
3844 0 : return;
3845 :
3846 136816 : opno = ((OpExpr *) clause)->opno;
3847 136816 : leftarg = linitial(((OpExpr *) clause)->args);
3848 :
3849 136816 : if (op_hashjoinable(opno, exprType(leftarg)) &&
3850 133188 : !contain_volatile_functions((Node *) restrictinfo))
3851 133180 : restrictinfo->hashjoinoperator = opno;
3852 : }
3853 :
3854 : /*
3855 : * check_memoizable
3856 : * If the restrictinfo's clause is suitable to be used for a Memoize node,
3857 : * set the left_hasheqoperator and right_hasheqoperator to the hash equality
3858 : * operator that will be needed during caching.
3859 : */
3860 : static void
3861 148828 : check_memoizable(RestrictInfo *restrictinfo)
3862 : {
3863 : TypeCacheEntry *typentry;
3864 148828 : Expr *clause = restrictinfo->clause;
3865 : Oid lefttype;
3866 : Oid righttype;
3867 :
3868 148828 : if (restrictinfo->pseudoconstant)
3869 3550 : return;
3870 145278 : if (!is_opclause(clause))
3871 8462 : return;
3872 136816 : if (list_length(((OpExpr *) clause)->args) != 2)
3873 0 : return;
3874 :
3875 136816 : lefttype = exprType(linitial(((OpExpr *) clause)->args));
3876 :
3877 136816 : typentry = lookup_type_cache(lefttype, TYPECACHE_HASH_PROC |
3878 : TYPECACHE_EQ_OPR);
3879 :
3880 136816 : if (OidIsValid(typentry->hash_proc) && OidIsValid(typentry->eq_opr))
3881 136408 : restrictinfo->left_hasheqoperator = typentry->eq_opr;
3882 :
3883 136816 : righttype = exprType(lsecond(((OpExpr *) clause)->args));
3884 :
3885 : /*
3886 : * Lookup the right type, unless it's the same as the left type, in which
3887 : * case typentry is already pointing to the required TypeCacheEntry.
3888 : */
3889 136816 : if (lefttype != righttype)
3890 2054 : typentry = lookup_type_cache(righttype, TYPECACHE_HASH_PROC |
3891 : TYPECACHE_EQ_OPR);
3892 :
3893 136816 : if (OidIsValid(typentry->hash_proc) && OidIsValid(typentry->eq_opr))
3894 136204 : restrictinfo->right_hasheqoperator = typentry->eq_opr;
3895 : }
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