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 798378 : add_base_rels_to_query(PlannerInfo *root, Node *jtnode)
159 : {
160 798378 : if (jtnode == NULL)
161 0 : return;
162 798378 : if (IsA(jtnode, RangeTblRef))
163 : {
164 418372 : int varno = ((RangeTblRef *) jtnode)->rtindex;
165 :
166 418372 : (void) build_simple_rel(root, varno, NULL);
167 : }
168 380006 : else if (IsA(jtnode, FromExpr))
169 : {
170 299228 : FromExpr *f = (FromExpr *) jtnode;
171 : ListCell *l;
172 :
173 645292 : foreach(l, f->fromlist)
174 346082 : add_base_rels_to_query(root, lfirst(l));
175 : }
176 80778 : else if (IsA(jtnode, JoinExpr))
177 : {
178 80778 : JoinExpr *j = (JoinExpr *) jtnode;
179 :
180 80778 : add_base_rels_to_query(root, j->larg);
181 80778 : 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 290722 : add_other_rels_to_query(PlannerInfo *root)
197 : {
198 : int rti;
199 :
200 879728 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
201 : {
202 589008 : RelOptInfo *rel = root->simple_rel_array[rti];
203 589008 : RangeTblEntry *rte = root->simple_rte_array[rti];
204 :
205 : /* there may be empty slots corresponding to non-baserel RTEs */
206 589008 : if (rel == NULL)
207 136776 : continue;
208 :
209 : /* Ignore any "otherrels" that were already added. */
210 452232 : if (rel->reloptkind != RELOPT_BASEREL)
211 43446 : continue;
212 :
213 : /* If it's marked as inheritable, look for children. */
214 408786 : if (rte->inh)
215 17532 : expand_inherited_rtentry(root, rel, rte, rti);
216 : }
217 290720 : }
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 290752 : build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
236 : {
237 290752 : List *tlist_vars = pull_var_clause((Node *) final_tlist,
238 : PVC_RECURSE_AGGREGATES |
239 : PVC_RECURSE_WINDOWFUNCS |
240 : PVC_INCLUDE_PLACEHOLDERS);
241 :
242 290752 : if (tlist_vars != NIL)
243 : {
244 274316 : add_vars_to_targetlist(root, tlist_vars, bms_make_singleton(0));
245 274316 : 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 290752 : if (root->parse->havingQual)
253 : {
254 1148 : List *having_vars = pull_var_clause(root->parse->havingQual,
255 : PVC_RECURSE_AGGREGATES |
256 : PVC_INCLUDE_PLACEHOLDERS);
257 :
258 1148 : if (having_vars != NIL)
259 : {
260 1052 : add_vars_to_targetlist(root, having_vars,
261 : bms_make_singleton(0));
262 1052 : list_free(having_vars);
263 : }
264 : }
265 290752 : }
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 531992 : 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 1891446 : foreach(temp, vars)
290 : {
291 1359454 : Node *node = (Node *) lfirst(temp);
292 :
293 1359454 : if (IsA(node, Var))
294 : {
295 1357774 : Var *var = (Var *) node;
296 1357774 : RelOptInfo *rel = find_base_rel(root, var->varno);
297 1357774 : int attno = var->varattno;
298 :
299 1357774 : if (bms_is_subset(where_needed, rel->relids))
300 790 : continue;
301 : Assert(attno >= rel->min_attr && attno <= rel->max_attr);
302 1356984 : attno -= rel->min_attr;
303 1356984 : 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 1047014 : var = copyObject(var);
313 1047014 : var->varnullingrels = NULL;
314 1047014 : rel->reltarget->exprs = lappend(rel->reltarget->exprs, var);
315 : /* reltarget cost and width will be computed later */
316 : }
317 1356984 : rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
318 : where_needed);
319 : }
320 1680 : else if (IsA(node, PlaceHolderVar))
321 : {
322 1680 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
323 1680 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
324 :
325 1680 : 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 531992 : }
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 11030 : 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 25930 : foreach(temp, vars)
361 : {
362 14900 : Node *node = (Node *) lfirst(temp);
363 :
364 14900 : if (IsA(node, Var))
365 : {
366 14834 : Var *var = (Var *) node;
367 14834 : RelOptInfo *rel = find_base_rel(root, var->varno);
368 14834 : int attno = var->varattno;
369 :
370 14834 : if (bms_is_subset(where_needed, rel->relids))
371 12 : continue;
372 : Assert(attno >= rel->min_attr && attno <= rel->max_attr);
373 14822 : attno -= rel->min_attr;
374 14822 : rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
375 : where_needed);
376 : }
377 66 : else if (IsA(node, PlaceHolderVar))
378 : {
379 66 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
380 66 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
381 :
382 66 : 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 11030 : }
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 290722 : remove_useless_groupby_columns(PlannerInfo *root)
413 : {
414 290722 : Query *parse = root->parse;
415 : Bitmapset **groupbyattnos;
416 : Bitmapset **surplusvars;
417 290722 : 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 290722 : if (list_length(root->processed_groupClause) < 2)
423 288764 : return;
424 :
425 : /* Don't fiddle with the GROUP BY clause if the query has grouping sets */
426 1958 : if (parse->groupingSets)
427 638 : 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)
528 336 : continue;
529 :
530 : /* For simplicity, we currently don't support expression indexes */
531 380 : if (index->indexprs != NIL)
532 0 : continue;
533 :
534 380 : ind_attnos = NULL;
535 380 : nulls_check_ok = true;
536 946 : 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 : */
546 572 : if (!index->nullsnotdistinct &&
547 566 : !bms_is_member(index->indexkeys[i],
548 566 : rel->notnullattnums))
549 : {
550 6 : nulls_check_ok = false;
551 6 : break;
552 : }
553 :
554 : ind_attnos =
555 566 : bms_add_member(ind_attnos,
556 566 : index->indexkeys[i] -
557 : FirstLowInvalidHeapAttributeNumber);
558 : }
559 :
560 380 : 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 : */
567 374 : if (bms_subset_compare(ind_attnos, relattnos) != BMS_SUBSET1)
568 156 : 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 : */
578 218 : 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 290722 : find_lateral_references(PlannerInfo *root)
659 : {
660 : Index rti;
661 :
662 : /* We need do nothing if the query contains no LATERAL RTEs */
663 290722 : if (!root->hasLateralRTEs)
664 280768 : return;
665 :
666 : /*
667 : * Examine all baserels (the rel array has been set up by now).
668 : */
669 35728 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
670 : {
671 25774 : RelOptInfo *brel = root->simple_rel_array[rti];
672 :
673 : /* there may be empty slots corresponding to non-baserel RTEs */
674 25774 : if (brel == NULL)
675 4354 : 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 21420 : if (brel->reloptkind != RELOPT_BASEREL)
699 0 : continue;
700 :
701 21420 : extract_lateral_references(root, brel, rti);
702 : }
703 : }
704 :
705 : static void
706 21420 : extract_lateral_references(PlannerInfo *root, RelOptInfo *brel, Index rtindex)
707 : {
708 21420 : 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 21420 : if (!rte->lateral)
716 11972 : return;
717 :
718 : /* Fetch the appropriate variables */
719 9448 : if (rte->rtekind == RTE_RELATION)
720 30 : vars = pull_vars_of_level((Node *) rte->tablesample, 0);
721 9418 : else if (rte->rtekind == RTE_SUBQUERY)
722 566 : vars = pull_vars_of_level((Node *) rte->subquery, 1);
723 8852 : else if (rte->rtekind == RTE_FUNCTION)
724 8564 : vars = pull_vars_of_level((Node *) rte->functions, 0);
725 288 : else if (rte->rtekind == RTE_TABLEFUNC)
726 234 : vars = pull_vars_of_level((Node *) rte->tablefunc, 0);
727 54 : else if (rte->rtekind == RTE_VALUES)
728 54 : 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 9448 : if (vars == NIL)
736 88 : return; /* nothing to do */
737 :
738 : /* Copy each Var (or PlaceHolderVar) and adjust it to match our level */
739 9360 : newvars = NIL;
740 19696 : foreach(lc, vars)
741 : {
742 10336 : Node *node = (Node *) lfirst(lc);
743 :
744 10336 : node = copyObject(node);
745 10336 : if (IsA(node, Var))
746 : {
747 10264 : Var *var = (Var *) node;
748 :
749 : /* Adjustment is easy since it's just one node */
750 10264 : var->varlevelsup = 0;
751 : }
752 72 : else if (IsA(node, PlaceHolderVar))
753 : {
754 72 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
755 72 : int levelsup = phv->phlevelsup;
756 :
757 : /* Have to work harder to adjust the contained expression too */
758 72 : 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 72 : if (levelsup > 0)
767 72 : phv->phexpr = preprocess_phv_expression(root, phv->phexpr);
768 : }
769 : else
770 : Assert(false);
771 10336 : newvars = lappend(newvars, node);
772 : }
773 :
774 9360 : 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 9360 : 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 9360 : 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 9360 : 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 9568 : rebuild_lateral_attr_needed(PlannerInfo *root)
808 : {
809 : Index rti;
810 :
811 : /* We need do nothing if the query contains no LATERAL RTEs */
812 9568 : if (!root->hasLateralRTEs)
813 9454 : return;
814 :
815 : /* Examine the same baserels that find_lateral_references did */
816 1164 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
817 : {
818 1050 : RelOptInfo *brel = root->simple_rel_array[rti];
819 : Relids where_needed;
820 :
821 1050 : if (brel == NULL)
822 666 : continue;
823 384 : 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 : */
830 384 : if (brel->lateral_vars == NIL)
831 294 : continue;
832 :
833 90 : where_needed = bms_make_singleton(rti);
834 :
835 90 : 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 290722 : create_lateral_join_info(PlannerInfo *root)
846 : {
847 290722 : bool found_laterals = false;
848 : Index rti;
849 : ListCell *lc;
850 :
851 : /* We need do nothing if the query contains no LATERAL RTEs */
852 290722 : if (!root->hasLateralRTEs)
853 280768 : 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 35728 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
862 : {
863 25774 : RelOptInfo *brel = root->simple_rel_array[rti];
864 : Relids lateral_relids;
865 :
866 : /* there may be empty slots corresponding to non-baserel RTEs */
867 25774 : if (brel == NULL)
868 4468 : continue;
869 :
870 : Assert(brel->relid == rti); /* sanity check on array */
871 :
872 : /* ignore RTEs that are "other rels" */
873 21306 : if (brel->reloptkind != RELOPT_BASEREL)
874 0 : continue;
875 :
876 21306 : lateral_relids = NULL;
877 :
878 : /* consider each laterally-referenced Var or PHV */
879 31618 : foreach(lc, brel->lateral_vars)
880 : {
881 10312 : Node *node = (Node *) lfirst(lc);
882 :
883 10312 : if (IsA(node, Var))
884 : {
885 10240 : Var *var = (Var *) node;
886 :
887 10240 : found_laterals = true;
888 10240 : lateral_relids = bms_add_member(lateral_relids,
889 : var->varno);
890 : }
891 72 : else if (IsA(node, PlaceHolderVar))
892 : {
893 72 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
894 72 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
895 :
896 72 : found_laterals = true;
897 72 : lateral_relids = bms_add_members(lateral_relids,
898 72 : 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 21306 : brel->direct_lateral_relids = lateral_relids;
906 21306 : 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 10348 : foreach(lc, root->placeholder_list)
923 : {
924 394 : PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
925 394 : Relids eval_at = phinfo->ph_eval_at;
926 : Relids lateral_refs;
927 : int varno;
928 :
929 394 : if (phinfo->ph_lateral == NULL)
930 144 : continue; /* PHV is uninteresting if no lateral refs */
931 :
932 250 : 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 : */
940 250 : lateral_refs = bms_intersect(phinfo->ph_lateral, root->all_baserels);
941 : Assert(!bms_is_empty(lateral_refs));
942 :
943 250 : if (bms_get_singleton_member(eval_at, &varno))
944 : {
945 : /* Evaluation site is a baserel */
946 184 : RelOptInfo *brel = find_base_rel(root, varno);
947 :
948 184 : brel->direct_lateral_relids =
949 184 : bms_add_members(brel->direct_lateral_relids,
950 : lateral_refs);
951 184 : brel->lateral_relids =
952 184 : 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 9954 : if (!found_laterals)
976 : {
977 452 : root->hasLateralRTEs = false;
978 452 : 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 33044 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
993 : {
994 23542 : RelOptInfo *brel = root->simple_rel_array[rti];
995 : Relids outer_lateral_relids;
996 : Index rti2;
997 :
998 23542 : if (brel == NULL || brel->reloptkind != RELOPT_BASEREL)
999 3212 : continue;
1000 :
1001 : /* need not consider baserel further if it has no lateral refs */
1002 20330 : outer_lateral_relids = brel->lateral_relids;
1003 20330 : if (outer_lateral_relids == NULL)
1004 10678 : continue;
1005 :
1006 : /* else scan all baserels */
1007 34124 : for (rti2 = 1; rti2 < root->simple_rel_array_size; rti2++)
1008 : {
1009 24472 : RelOptInfo *brel2 = root->simple_rel_array[rti2];
1010 :
1011 24472 : if (brel2 == NULL || brel2->reloptkind != RELOPT_BASEREL)
1012 3596 : continue;
1013 :
1014 : /* if brel2 has lateral ref to brel, propagate brel's refs */
1015 20876 : 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 33044 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1027 : {
1028 23542 : RelOptInfo *brel = root->simple_rel_array[rti];
1029 : Relids lateral_relids;
1030 : int rti2;
1031 :
1032 23542 : if (brel == NULL || brel->reloptkind != RELOPT_BASEREL)
1033 3212 : continue;
1034 :
1035 : /* Nothing to do at rels with no lateral refs */
1036 20330 : lateral_relids = brel->lateral_relids;
1037 20330 : if (bms_is_empty(lateral_relids))
1038 10678 : 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 9652 : rti2 = -1;
1045 19532 : while ((rti2 = bms_next_member(lateral_relids, rti2)) >= 0)
1046 : {
1047 9880 : RelOptInfo *brel2 = root->simple_rel_array[rti2];
1048 :
1049 9880 : if (brel2 == NULL)
1050 12 : continue; /* must be an OJ */
1051 :
1052 : Assert(brel2->reloptkind == RELOPT_BASEREL);
1053 9868 : brel2->lateral_referencers =
1054 9868 : 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 290722 : deconstruct_jointree(PlannerInfo *root)
1085 : {
1086 : List *result;
1087 : JoinDomain *top_jdomain;
1088 290722 : 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 290722 : root->placeholdersFrozen = true;
1097 :
1098 : /* Fetch the already-created top-level join domain for the query */
1099 290722 : top_jdomain = linitial_node(JoinDomain, root->join_domains);
1100 290722 : 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 290722 : root->all_baserels = NULL;
1108 290722 : root->outer_join_rels = NULL;
1109 :
1110 : /* Perform the initial scan of the jointree */
1111 290722 : 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 290722 : 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 1089064 : foreach(lc, item_list)
1123 : {
1124 798342 : JoinTreeItem *jtitem = (JoinTreeItem *) lfirst(lc);
1125 :
1126 798342 : 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 290722 : if (root->join_info_list)
1134 : {
1135 216628 : foreach(lc, item_list)
1136 : {
1137 183706 : JoinTreeItem *jtitem = (JoinTreeItem *) lfirst(lc);
1138 :
1139 183706 : if (jtitem->oj_joinclauses != NIL)
1140 37932 : deconstruct_distribute_oj_quals(root, item_list, jtitem);
1141 : }
1142 : }
1143 :
1144 : /* Don't need the JoinTreeItems any more */
1145 290722 : list_free_deep(item_list);
1146 :
1147 290722 : 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 798342 : 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 798342 : jtitem = palloc0_object(JoinTreeItem);
1178 798342 : jtitem->jtnode = jtnode;
1179 798342 : jtitem->jti_parent = parent_jtitem;
1180 :
1181 798342 : if (IsA(jtnode, RangeTblRef))
1182 : {
1183 418354 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1184 :
1185 : /* Fill all_baserels as we encounter baserel jointree nodes */
1186 418354 : root->all_baserels = bms_add_member(root->all_baserels, varno);
1187 : /* This node belongs to parent_domain */
1188 418354 : jtitem->jdomain = parent_domain;
1189 418354 : parent_domain->jd_relids = bms_add_member(parent_domain->jd_relids,
1190 : varno);
1191 : /* qualscope is just the one RTE */
1192 418354 : jtitem->qualscope = bms_make_singleton(varno);
1193 : /* A single baserel does not create an inner join */
1194 418354 : jtitem->inner_join_rels = NULL;
1195 418354 : joinlist = list_make1(jtnode);
1196 : }
1197 379988 : else if (IsA(jtnode, FromExpr))
1198 : {
1199 299210 : FromExpr *f = (FromExpr *) jtnode;
1200 : int remaining;
1201 : ListCell *l;
1202 :
1203 : /* This node belongs to parent_domain, as do its children */
1204 299210 : 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 299210 : jtitem->qualscope = NULL;
1214 299210 : jtitem->inner_join_rels = NULL;
1215 299210 : joinlist = NIL;
1216 299210 : remaining = list_length(f->fromlist);
1217 645274 : foreach(l, f->fromlist)
1218 : {
1219 : JoinTreeItem *sub_item;
1220 : List *sub_joinlist;
1221 : int sub_members;
1222 :
1223 346064 : sub_joinlist = deconstruct_recurse(root, lfirst(l),
1224 : parent_domain,
1225 : jtitem,
1226 : item_list);
1227 346064 : sub_item = (JoinTreeItem *) llast(*item_list);
1228 692128 : jtitem->qualscope = bms_add_members(jtitem->qualscope,
1229 346064 : sub_item->qualscope);
1230 346064 : jtitem->inner_join_rels = sub_item->inner_join_rels;
1231 346064 : sub_members = list_length(sub_joinlist);
1232 346064 : remaining--;
1233 346064 : if (sub_members <= 1 ||
1234 50984 : list_length(joinlist) + sub_members + remaining <= from_collapse_limit)
1235 346064 : 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 299210 : if (list_length(f->fromlist) > 1)
1248 42836 : jtitem->inner_join_rels = jtitem->qualscope;
1249 : }
1250 80778 : else if (IsA(jtnode, JoinExpr))
1251 : {
1252 80778 : 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 80778 : switch (j->jointype)
1261 : {
1262 35048 : case JOIN_INNER:
1263 : /* This node belongs to parent_domain, as do its children */
1264 35048 : jtitem->jdomain = parent_domain;
1265 : /* Recurse */
1266 35048 : leftjoinlist = deconstruct_recurse(root, j->larg,
1267 : parent_domain,
1268 : jtitem,
1269 : item_list);
1270 35048 : left_item = (JoinTreeItem *) llast(*item_list);
1271 35048 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1272 : parent_domain,
1273 : jtitem,
1274 : item_list);
1275 35048 : right_item = (JoinTreeItem *) llast(*item_list);
1276 : /* Compute qualscope etc */
1277 70096 : jtitem->qualscope = bms_union(left_item->qualscope,
1278 35048 : right_item->qualscope);
1279 35048 : jtitem->inner_join_rels = jtitem->qualscope;
1280 35048 : jtitem->left_rels = left_item->qualscope;
1281 35048 : jtitem->right_rels = right_item->qualscope;
1282 : /* Inner join adds no restrictions for quals */
1283 35048 : jtitem->nonnullable_rels = NULL;
1284 35048 : break;
1285 42802 : case JOIN_LEFT:
1286 : case JOIN_ANTI:
1287 : /* Make new join domain for my quals and the RHS */
1288 42802 : child_domain = makeNode(JoinDomain);
1289 42802 : child_domain->jd_relids = NULL; /* filled by recursion */
1290 42802 : root->join_domains = lappend(root->join_domains, child_domain);
1291 42802 : jtitem->jdomain = child_domain;
1292 : /* Recurse */
1293 42802 : leftjoinlist = deconstruct_recurse(root, j->larg,
1294 : parent_domain,
1295 : jtitem,
1296 : item_list);
1297 42802 : left_item = (JoinTreeItem *) llast(*item_list);
1298 42802 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1299 : child_domain,
1300 : jtitem,
1301 : item_list);
1302 42802 : right_item = (JoinTreeItem *) llast(*item_list);
1303 : /* Compute join domain contents, qualscope etc */
1304 42802 : parent_domain->jd_relids =
1305 42802 : bms_add_members(parent_domain->jd_relids,
1306 42802 : child_domain->jd_relids);
1307 85604 : jtitem->qualscope = bms_union(left_item->qualscope,
1308 42802 : right_item->qualscope);
1309 : /* caution: ANTI join derived from SEMI will lack rtindex */
1310 42802 : if (j->rtindex != 0)
1311 : {
1312 40308 : parent_domain->jd_relids =
1313 40308 : bms_add_member(parent_domain->jd_relids,
1314 : j->rtindex);
1315 40308 : jtitem->qualscope = bms_add_member(jtitem->qualscope,
1316 : j->rtindex);
1317 40308 : root->outer_join_rels = bms_add_member(root->outer_join_rels,
1318 : j->rtindex);
1319 40308 : mark_rels_nulled_by_join(root, j->rtindex,
1320 : right_item->qualscope);
1321 : }
1322 85604 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1323 42802 : right_item->inner_join_rels);
1324 42802 : jtitem->left_rels = left_item->qualscope;
1325 42802 : jtitem->right_rels = right_item->qualscope;
1326 42802 : jtitem->nonnullable_rels = left_item->qualscope;
1327 42802 : break;
1328 1924 : case JOIN_SEMI:
1329 : /* This node belongs to parent_domain, as do its children */
1330 1924 : jtitem->jdomain = parent_domain;
1331 : /* Recurse */
1332 1924 : leftjoinlist = deconstruct_recurse(root, j->larg,
1333 : parent_domain,
1334 : jtitem,
1335 : item_list);
1336 1924 : left_item = (JoinTreeItem *) llast(*item_list);
1337 1924 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1338 : parent_domain,
1339 : jtitem,
1340 : item_list);
1341 1924 : right_item = (JoinTreeItem *) llast(*item_list);
1342 : /* Compute qualscope etc */
1343 3848 : jtitem->qualscope = bms_union(left_item->qualscope,
1344 1924 : right_item->qualscope);
1345 : /* SEMI join never has rtindex, so don't add to anything */
1346 : Assert(j->rtindex == 0);
1347 3848 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1348 1924 : right_item->inner_join_rels);
1349 1924 : jtitem->left_rels = left_item->qualscope;
1350 1924 : jtitem->right_rels = right_item->qualscope;
1351 : /* Semi join adds no restrictions for quals */
1352 1924 : jtitem->nonnullable_rels = NULL;
1353 1924 : break;
1354 1004 : case JOIN_FULL:
1355 : /* The FULL JOIN's quals need their very own domain */
1356 1004 : fj_domain = makeNode(JoinDomain);
1357 1004 : root->join_domains = lappend(root->join_domains, fj_domain);
1358 1004 : jtitem->jdomain = fj_domain;
1359 : /* Recurse, giving each side its own join domain */
1360 1004 : child_domain = makeNode(JoinDomain);
1361 1004 : child_domain->jd_relids = NULL; /* filled by recursion */
1362 1004 : root->join_domains = lappend(root->join_domains, child_domain);
1363 1004 : leftjoinlist = deconstruct_recurse(root, j->larg,
1364 : child_domain,
1365 : jtitem,
1366 : item_list);
1367 1004 : left_item = (JoinTreeItem *) llast(*item_list);
1368 1004 : fj_domain->jd_relids = bms_copy(child_domain->jd_relids);
1369 1004 : child_domain = makeNode(JoinDomain);
1370 1004 : child_domain->jd_relids = NULL; /* filled by recursion */
1371 1004 : root->join_domains = lappend(root->join_domains, child_domain);
1372 1004 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1373 : child_domain,
1374 : jtitem,
1375 : item_list);
1376 1004 : right_item = (JoinTreeItem *) llast(*item_list);
1377 : /* Compute qualscope etc */
1378 2008 : fj_domain->jd_relids = bms_add_members(fj_domain->jd_relids,
1379 1004 : child_domain->jd_relids);
1380 2008 : parent_domain->jd_relids = bms_add_members(parent_domain->jd_relids,
1381 1004 : fj_domain->jd_relids);
1382 2008 : jtitem->qualscope = bms_union(left_item->qualscope,
1383 1004 : right_item->qualscope);
1384 : Assert(j->rtindex != 0);
1385 1004 : parent_domain->jd_relids = bms_add_member(parent_domain->jd_relids,
1386 : j->rtindex);
1387 1004 : jtitem->qualscope = bms_add_member(jtitem->qualscope,
1388 : j->rtindex);
1389 1004 : root->outer_join_rels = bms_add_member(root->outer_join_rels,
1390 : j->rtindex);
1391 1004 : mark_rels_nulled_by_join(root, j->rtindex,
1392 : left_item->qualscope);
1393 1004 : mark_rels_nulled_by_join(root, j->rtindex,
1394 : right_item->qualscope);
1395 2008 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1396 1004 : right_item->inner_join_rels);
1397 1004 : jtitem->left_rels = left_item->qualscope;
1398 1004 : jtitem->right_rels = right_item->qualscope;
1399 : /* each side is both outer and inner */
1400 1004 : jtitem->nonnullable_rels = jtitem->qualscope;
1401 1004 : 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 80778 : if (j->jointype == JOIN_FULL)
1415 : {
1416 : /* force the join order exactly at this node */
1417 1004 : joinlist = list_make1(list_make2(leftjoinlist, rightjoinlist));
1418 : }
1419 79774 : else if (list_length(leftjoinlist) + list_length(rightjoinlist) <=
1420 : join_collapse_limit)
1421 : {
1422 : /* OK to combine subproblems */
1423 79648 : 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 126 : if (list_length(leftjoinlist) == 1)
1433 6 : leftpart = (Node *) linitial(leftjoinlist);
1434 : else
1435 120 : leftpart = (Node *) leftjoinlist;
1436 126 : if (list_length(rightjoinlist) == 1)
1437 0 : rightpart = (Node *) linitial(rightjoinlist);
1438 : else
1439 126 : rightpart = (Node *) rightjoinlist;
1440 126 : 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 798342 : *item_list = lappend(*item_list, jtitem);
1452 :
1453 798342 : 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 798342 : deconstruct_distribute(PlannerInfo *root, JoinTreeItem *jtitem)
1465 : {
1466 798342 : Node *jtnode = jtitem->jtnode;
1467 :
1468 798342 : if (IsA(jtnode, RangeTblRef))
1469 : {
1470 418354 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1471 :
1472 : /* Deal with any securityQuals attached to the RTE */
1473 418354 : if (root->qual_security_level > 0)
1474 2682 : process_security_barrier_quals(root,
1475 : varno,
1476 : jtitem);
1477 : }
1478 379988 : else if (IsA(jtnode, FromExpr))
1479 : {
1480 299210 : FromExpr *f = (FromExpr *) jtnode;
1481 :
1482 : /*
1483 : * Process any lateral-referencing quals that were postponed to this
1484 : * level by children.
1485 : */
1486 299210 : 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 299210 : 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 80778 : else if (IsA(jtnode, JoinExpr))
1508 : {
1509 80778 : 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 80778 : my_quals = list_concat(jtitem->lateral_clauses,
1522 80778 : (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 80778 : if (j->jointype != JOIN_INNER)
1532 : {
1533 45730 : sjinfo = make_outerjoininfo(root,
1534 : jtitem->left_rels,
1535 : jtitem->right_rels,
1536 : jtitem->inner_join_rels,
1537 : j->jointype,
1538 45730 : j->rtindex,
1539 : my_quals);
1540 45730 : jtitem->sjinfo = sjinfo;
1541 45730 : if (j->jointype == JOIN_SEMI)
1542 1924 : ojscope = NULL;
1543 : else
1544 43806 : ojscope = bms_union(sjinfo->min_lefthand,
1545 43806 : sjinfo->min_righthand);
1546 : }
1547 : else
1548 : {
1549 35048 : sjinfo = NULL;
1550 35048 : 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 80778 : if (j->jointype == JOIN_LEFT && sjinfo->lhs_strict)
1561 : {
1562 37932 : 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 37932 : ojscope = bms_add_members(ojscope, sjinfo->commute_below_l);
1574 37932 : ojscope = bms_add_members(ojscope, sjinfo->commute_below_r);
1575 : }
1576 : else
1577 42846 : postponed_oj_qual_list = NULL;
1578 :
1579 : /* Process the JOIN's qual clauses */
1580 80778 : 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 80778 : if (sjinfo)
1593 45730 : 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 798342 : }
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 2682 : process_security_barrier_quals(PlannerInfo *root,
1617 : int rti, JoinTreeItem *jtitem)
1618 : {
1619 2682 : RangeTblEntry *rte = root->simple_rte_array[rti];
1620 2682 : 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 5482 : foreach(lc, rte->securityQuals)
1630 : {
1631 2800 : 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 2800 : 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 2800 : 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 2682 : }
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 42316 : mark_rels_nulled_by_join(PlannerInfo *root, Index ojrelid,
1667 : Relids lower_rels)
1668 : {
1669 42316 : int relid = -1;
1670 :
1671 87294 : while ((relid = bms_next_member(lower_rels, relid)) > 0)
1672 : {
1673 44978 : RelOptInfo *rel = root->simple_rel_array[relid];
1674 :
1675 : /* ignore the RTE_GROUP RTE */
1676 44978 : if (relid == root->group_rtindex)
1677 0 : continue;
1678 :
1679 44978 : if (rel == NULL) /* must be an outer join */
1680 : {
1681 : Assert(bms_is_member(relid, root->outer_join_rels));
1682 788 : continue;
1683 : }
1684 44190 : rel->nulling_relids = bms_add_member(rel->nulling_relids, ojrelid);
1685 : }
1686 42316 : }
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 45730 : 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 45730 : 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 45774 : 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 45730 : sjinfo->syn_lefthand = left_rels;
1760 45730 : sjinfo->syn_righthand = right_rels;
1761 45730 : sjinfo->jointype = jointype;
1762 45730 : sjinfo->ojrelid = ojrelid;
1763 : /* these fields may get added to later: */
1764 45730 : sjinfo->commute_above_l = NULL;
1765 45730 : sjinfo->commute_above_r = NULL;
1766 45730 : sjinfo->commute_below_l = NULL;
1767 45730 : sjinfo->commute_below_r = NULL;
1768 :
1769 45730 : compute_semijoin_info(root, sjinfo, clause);
1770 :
1771 : /* If it's a full join, no need to be very smart */
1772 45730 : if (jointype == JOIN_FULL)
1773 : {
1774 1004 : sjinfo->min_lefthand = bms_copy(left_rels);
1775 1004 : sjinfo->min_righthand = bms_copy(right_rels);
1776 1004 : sjinfo->lhs_strict = false; /* don't care about this */
1777 1004 : return sjinfo;
1778 : }
1779 :
1780 : /*
1781 : * Retrieve all relids mentioned within the join clause.
1782 : */
1783 44726 : 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 44726 : strict_relids = find_nonnullable_rels((Node *) clause);
1790 :
1791 : /* Remember whether the clause is strict for any LHS relations */
1792 44726 : 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 44726 : 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 44726 : 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 44726 : commute_below_l = commute_below_r = NULL;
1817 59552 : foreach(l, root->join_info_list)
1818 : {
1819 14826 : 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 14826 : if (otherinfo->jointype == JOIN_FULL)
1828 : {
1829 : Assert(otherinfo->ojrelid != 0);
1830 82 : if (bms_overlap(left_rels, otherinfo->syn_lefthand) ||
1831 30 : bms_overlap(left_rels, otherinfo->syn_righthand))
1832 : {
1833 22 : min_lefthand = bms_add_members(min_lefthand,
1834 22 : otherinfo->syn_lefthand);
1835 22 : min_lefthand = bms_add_members(min_lefthand,
1836 22 : otherinfo->syn_righthand);
1837 22 : min_lefthand = bms_add_member(min_lefthand,
1838 22 : otherinfo->ojrelid);
1839 : }
1840 74 : if (bms_overlap(right_rels, otherinfo->syn_lefthand) ||
1841 22 : 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 52 : 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 14774 : if (otherinfo->ojrelid != 0)
1859 : have_unsafe_phvs =
1860 14496 : contain_placeholder_references_to(root,
1861 : (Node *) clause,
1862 14496 : otherinfo->ojrelid);
1863 : else
1864 278 : 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 14774 : if (bms_overlap(left_rels, otherinfo->syn_righthand))
1885 : {
1886 13950 : if (bms_overlap(clause_relids, otherinfo->syn_righthand) &&
1887 4384 : (have_unsafe_phvs ||
1888 4384 : jointype == JOIN_SEMI || jointype == JOIN_ANTI ||
1889 4384 : !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 13908 : else if (jointype == JOIN_LEFT &&
1901 26792 : otherinfo->jointype == JOIN_LEFT &&
1902 13396 : bms_overlap(strict_relids, otherinfo->min_righthand) &&
1903 4354 : !bms_overlap(clause_relids, otherinfo->syn_lefthand))
1904 : {
1905 : /* Identity 3 applies, so remove the ordering restriction */
1906 4300 : min_lefthand = bms_del_member(min_lefthand, otherinfo->ojrelid);
1907 : /* Record the (still tentative) commutability relationship */
1908 : commute_below_l =
1909 4300 : 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 14774 : if (bms_overlap(right_rels, otherinfo->syn_righthand))
1932 : {
1933 748 : if (bms_overlap(clause_relids, otherinfo->syn_righthand) ||
1934 700 : !bms_overlap(clause_relids, otherinfo->min_lefthand) ||
1935 406 : have_unsafe_phvs ||
1936 316 : jointype == JOIN_SEMI ||
1937 310 : jointype == JOIN_ANTI ||
1938 310 : otherinfo->jointype == JOIN_SEMI ||
1939 280 : otherinfo->jointype == JOIN_ANTI ||
1940 280 : !otherinfo->lhs_strict)
1941 : {
1942 : /* Preserve ordering */
1943 498 : min_righthand = bms_add_members(min_righthand,
1944 498 : otherinfo->syn_lefthand);
1945 498 : min_righthand = bms_add_members(min_righthand,
1946 498 : otherinfo->syn_righthand);
1947 498 : if (otherinfo->ojrelid != 0)
1948 378 : min_righthand = bms_add_member(min_righthand,
1949 378 : otherinfo->ojrelid);
1950 : }
1951 250 : else if (jointype == JOIN_LEFT &&
1952 250 : otherinfo->jointype == JOIN_LEFT &&
1953 250 : otherinfo->lhs_strict)
1954 : {
1955 : /* Identity 3 applies, so remove the ordering restriction */
1956 250 : min_righthand = bms_del_member(min_righthand,
1957 250 : otherinfo->ojrelid);
1958 : /* Record the (still tentative) commutability relationship */
1959 : commute_below_r =
1960 250 : 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 45958 : foreach(l, root->placeholder_list)
1974 : {
1975 1232 : PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(l);
1976 1232 : Relids ph_syn_level = phinfo->ph_var->phrels;
1977 :
1978 : /* Ignore placeholder if it didn't syntactically come from RHS */
1979 1232 : if (!bms_is_subset(ph_syn_level, right_rels))
1980 430 : continue;
1981 :
1982 : /* Else, prevent join from being formed before we eval the PHV */
1983 802 : 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 44726 : if (bms_is_empty(min_lefthand))
1993 1268 : min_lefthand = bms_copy(left_rels);
1994 44726 : if (bms_is_empty(min_righthand))
1995 488 : 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 44726 : sjinfo->min_lefthand = min_lefthand;
2004 44726 : 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 44726 : commute_below_l = bms_del_members(commute_below_l, min_lefthand);
2016 44726 : commute_below_r = bms_del_members(commute_below_r, min_righthand);
2017 :
2018 : /* Anything left? */
2019 44726 : if (commute_below_l || commute_below_r)
2020 : {
2021 : /* Yup, so we must update the derived data in the SpecialJoinInfos */
2022 4472 : sjinfo->commute_below_l = commute_below_l;
2023 4472 : sjinfo->commute_below_r = commute_below_r;
2024 9384 : foreach(l, root->join_info_list)
2025 : {
2026 4912 : SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l);
2027 :
2028 4912 : if (bms_is_member(otherinfo->ojrelid, commute_below_l))
2029 4300 : otherinfo->commute_above_l =
2030 4300 : bms_add_member(otherinfo->commute_above_l, ojrelid);
2031 612 : else if (bms_is_member(otherinfo->ojrelid, commute_below_r))
2032 220 : otherinfo->commute_above_r =
2033 220 : bms_add_member(otherinfo->commute_above_r, ojrelid);
2034 : }
2035 : }
2036 :
2037 44726 : 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 45730 : 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 45730 : sjinfo->semi_can_btree = false;
2058 45730 : sjinfo->semi_can_hash = false;
2059 45730 : sjinfo->semi_operators = NIL;
2060 45730 : sjinfo->semi_rhs_exprs = NIL;
2061 :
2062 : /* Nothing more to do if it's not a semijoin */
2063 45730 : if (sjinfo->jointype != JOIN_SEMI)
2064 43806 : 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 1924 : semi_operators = NIL;
2093 1924 : semi_rhs_exprs = NIL;
2094 1924 : all_btree = true;
2095 1924 : all_hash = enable_hashagg; /* don't consider hash if not enabled */
2096 4084 : foreach(lc, clause)
2097 : {
2098 2262 : 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 4416 : if (!IsA(op, OpExpr) ||
2109 2154 : 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 2154 : opno = op->opno;
2131 2154 : left_expr = linitial(op->args);
2132 2154 : right_expr = lsecond(op->args);
2133 2154 : left_varnos = pull_varnos(root, left_expr);
2134 2154 : right_varnos = pull_varnos(root, right_expr);
2135 2154 : all_varnos = bms_union(left_varnos, right_varnos);
2136 2154 : opinputtype = exprType(left_expr);
2137 :
2138 : /* Does it reference both sides? */
2139 4308 : if (!bms_overlap(all_varnos, sjinfo->syn_righthand) ||
2140 2154 : 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 38 : if (contain_volatile_functions((Node *) op))
2147 0 : return;
2148 38 : continue;
2149 : }
2150 :
2151 : /* check rel membership of arguments */
2152 4232 : if (!bms_is_empty(right_varnos) &&
2153 2116 : bms_is_subset(right_varnos, sjinfo->syn_righthand) &&
2154 1706 : !bms_overlap(left_varnos, sjinfo->syn_righthand))
2155 : {
2156 : /* typical case, right_expr is RHS variable */
2157 : }
2158 820 : else if (!bms_is_empty(left_varnos) &&
2159 410 : bms_is_subset(left_varnos, sjinfo->syn_righthand) &&
2160 404 : !bms_overlap(right_varnos, sjinfo->syn_righthand))
2161 : {
2162 : /* flipped case, left_expr is RHS variable */
2163 404 : opno = get_commutator(opno);
2164 404 : if (!OidIsValid(opno))
2165 0 : return;
2166 404 : 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 2110 : if (all_btree)
2176 : {
2177 : /* oprcanmerge is considered a hint... */
2178 4136 : if (!op_mergejoinable(opno, opinputtype) ||
2179 2026 : get_mergejoin_opfamilies(opno) == NIL)
2180 84 : all_btree = false;
2181 : }
2182 2110 : if (all_hash)
2183 : {
2184 : /* ... but oprcanhash had better be correct */
2185 2038 : if (!op_hashjoinable(opno, opinputtype))
2186 84 : all_hash = false;
2187 : }
2188 2110 : if (!(all_btree || all_hash))
2189 84 : return;
2190 :
2191 : /* so far so good, keep building lists */
2192 2026 : semi_operators = lappend_oid(semi_operators, opno);
2193 2026 : 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 1822 : 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 1810 : 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 1810 : sjinfo->semi_can_btree = all_btree;
2211 1810 : sjinfo->semi_can_hash = all_hash;
2212 1810 : sjinfo->semi_operators = semi_operators;
2213 1810 : 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 37932 : deconstruct_distribute_oj_quals(PlannerInfo *root,
2227 : List *jtitems,
2228 : JoinTreeItem *jtitem)
2229 : {
2230 37932 : SpecialJoinInfo *sjinfo = jtitem->sjinfo;
2231 : Relids qualscope,
2232 : ojscope,
2233 : nonnullable_rels;
2234 :
2235 : /* Recompute syntactic and semantic scopes of this left join */
2236 37932 : qualscope = bms_union(sjinfo->syn_lefthand, sjinfo->syn_righthand);
2237 37932 : qualscope = bms_add_member(qualscope, sjinfo->ojrelid);
2238 37932 : ojscope = bms_union(sjinfo->min_lefthand, sjinfo->min_righthand);
2239 37932 : 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 37932 : if (sjinfo->commute_above_r || sjinfo->commute_below_l)
2250 4484 : {
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 4484 : joins_above = sjinfo->commute_above_r;
2261 4484 : 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 4484 : quals = jtitem->oj_joinclauses;
2282 4484 : if (!bms_is_empty(joins_below))
2283 4264 : 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 4484 : incompatible_joins = bms_union(joins_below, joins_above);
2293 4484 : incompatible_joins = bms_add_member(incompatible_joins,
2294 4484 : 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 4484 : save_last_rinfo_serial = root->last_rinfo_serial;
2305 :
2306 4484 : joins_so_far = NULL;
2307 38172 : foreach(lc, jtitems)
2308 : {
2309 33688 : JoinTreeItem *otherjtitem = (JoinTreeItem *) lfirst(lc);
2310 33688 : SpecialJoinInfo *othersj = otherjtitem->sjinfo;
2311 33688 : bool below_sjinfo = false;
2312 33688 : bool above_sjinfo = false;
2313 : Relids this_qualscope;
2314 : Relids this_ojscope;
2315 : bool allow_equivalence,
2316 : has_clone,
2317 : is_clone;
2318 :
2319 33688 : if (othersj == NULL)
2320 24060 : continue; /* not an outer-join item, ignore */
2321 :
2322 9628 : if (bms_is_member(othersj->ojrelid, joins_below))
2323 : {
2324 : /* othersj commutes with sjinfo from below left */
2325 4300 : below_sjinfo = true;
2326 : }
2327 5328 : else if (othersj == sjinfo)
2328 : {
2329 : /* found our join in syntactic order */
2330 : Assert(bms_equal(joins_so_far, joins_below));
2331 : }
2332 844 : else if (bms_is_member(othersj->ojrelid, joins_above))
2333 : {
2334 : /* othersj commutes with sjinfo from above */
2335 220 : above_sjinfo = true;
2336 : }
2337 : else
2338 : {
2339 : /* othersj is not relevant, ignore */
2340 624 : continue;
2341 : }
2342 :
2343 : /* Reset serial counter for this version of the quals */
2344 9004 : 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 9004 : if (above_sjinfo)
2360 : {
2361 : quals = (List *)
2362 220 : add_nulling_relids((Node *) quals,
2363 220 : sjinfo->syn_lefthand,
2364 220 : bms_make_singleton(othersj->ojrelid));
2365 220 : incompatible_joins = bms_del_member(incompatible_joins,
2366 220 : othersj->ojrelid);
2367 : }
2368 :
2369 : /* Compute qualscope and ojscope for this join level */
2370 9004 : this_qualscope = bms_union(qualscope, joins_so_far);
2371 9004 : this_ojscope = bms_union(ojscope, joins_so_far);
2372 9004 : if (above_sjinfo)
2373 : {
2374 : /* othersj is not yet in joins_so_far, but we need it */
2375 220 : this_qualscope = bms_add_member(this_qualscope,
2376 220 : othersj->ojrelid);
2377 220 : this_ojscope = bms_add_member(this_ojscope,
2378 220 : othersj->ojrelid);
2379 : /* sjinfo is in joins_so_far, and we don't want it */
2380 220 : this_ojscope = bms_del_member(this_ojscope,
2381 220 : 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 9004 : allow_equivalence = (joins_so_far == NULL);
2400 9004 : has_clone = allow_equivalence;
2401 9004 : is_clone = !has_clone;
2402 :
2403 9004 : 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 9004 : if (below_sjinfo)
2425 : {
2426 : quals = (List *)
2427 4300 : add_nulling_relids((Node *) quals,
2428 4300 : othersj->syn_righthand,
2429 4300 : bms_make_singleton(othersj->ojrelid));
2430 4300 : incompatible_joins = bms_del_member(incompatible_joins,
2431 4300 : othersj->ojrelid);
2432 : }
2433 :
2434 : /* ... and track joins processed so far */
2435 9004 : 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 33448 : 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 37932 : }
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 724450 : 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 1245072 : foreach(lc, clauses)
2483 : {
2484 520622 : Node *clause = (Node *) lfirst(lc);
2485 :
2486 520622 : 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 724450 : }
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 520622 : 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 520622 : 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 520622 : 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 520622 : 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 360784 : 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 520512 : 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 520512 : if (bms_is_empty(relids))
2634 : {
2635 9914 : if (ojscope)
2636 : {
2637 : /* clause is attached to outer join, eval it there */
2638 380 : relids = bms_copy(ojscope);
2639 : /* mustn't use as gating qual, so don't mark pseudoconstant */
2640 : }
2641 9534 : 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 9360 : if (jtitem->jdomain == (JoinDomain *) linitial(root->join_domains))
2659 9312 : relids = bms_copy(jtitem->jdomain->jd_relids);
2660 : else
2661 48 : relids = bms_copy(qualscope);
2662 : /* mark as gating qual */
2663 9360 : pseudoconstant = true;
2664 : /* tell createplan.c to check for gating quals */
2665 9360 : 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 520512 : 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 94128 : if (postponed_oj_qual_list != NULL)
2711 : {
2712 41786 : *postponed_oj_qual_list = lappend(*postponed_oj_qual_list, clause);
2713 41786 : 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 52342 : is_pushed_down = false;
2724 52342 : maybe_equivalence = false;
2725 52342 : 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 52342 : 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 426384 : 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 426384 : if (check_redundant_nullability_qual(root, clause))
2753 1020 : return;
2754 :
2755 : /* Feed qual to the equivalence machinery, if allowed by caller */
2756 425364 : 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 425364 : maybe_outer_join = false;
2763 : }
2764 :
2765 : /*
2766 : * Build the RestrictInfo node itself.
2767 : */
2768 477706 : 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 477706 : if (bms_membership(relids) == BMS_MULTIPLE)
2801 : {
2802 133098 : List *vars = pull_var_clause(clause,
2803 : PVC_RECURSE_AGGREGATES |
2804 : PVC_RECURSE_WINDOWFUNCS |
2805 : PVC_INCLUDE_PLACEHOLDERS);
2806 : Relids where_needed;
2807 :
2808 133098 : if (is_clone)
2809 4568 : where_needed = bms_intersect(relids, root->all_baserels);
2810 : else
2811 128530 : where_needed = relids;
2812 133098 : add_vars_to_targetlist(root, vars, where_needed);
2813 133098 : 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 477706 : 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 477706 : if (restrictinfo->mergeopfamilies)
2856 : {
2857 319022 : if (maybe_equivalence)
2858 : {
2859 268016 : if (process_equivalence(root, &restrictinfo, jtitem->jdomain))
2860 267760 : return;
2861 : /* EC rejected it, so set left_ec/right_ec the hard way ... */
2862 256 : if (restrictinfo->mergeopfamilies) /* EC might have changed this */
2863 202 : initialize_mergeclause_eclasses(root, restrictinfo);
2864 : /* ... and fall through to distribute_restrictinfo_to_rels */
2865 : }
2866 51006 : else if (maybe_outer_join && restrictinfo->can_join)
2867 : {
2868 : /* we need to set up left_ec/right_ec the hard way */
2869 50328 : initialize_mergeclause_eclasses(root, restrictinfo);
2870 : /* now see if it should go to any outer-join lists */
2871 : Assert(sjinfo != NULL);
2872 50328 : if (bms_is_subset(restrictinfo->left_relids,
2873 24772 : outerjoin_nonnullable) &&
2874 24772 : !bms_overlap(restrictinfo->right_relids,
2875 : outerjoin_nonnullable))
2876 : {
2877 : /* we have outervar = innervar */
2878 23502 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
2879 :
2880 23502 : ojcinfo->rinfo = restrictinfo;
2881 23502 : ojcinfo->sjinfo = sjinfo;
2882 23502 : root->left_join_clauses = lappend(root->left_join_clauses,
2883 : ojcinfo);
2884 23502 : return;
2885 : }
2886 26826 : if (bms_is_subset(restrictinfo->right_relids,
2887 26642 : outerjoin_nonnullable) &&
2888 26642 : !bms_overlap(restrictinfo->left_relids,
2889 : outerjoin_nonnullable))
2890 : {
2891 : /* we have innervar = outervar */
2892 25372 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
2893 :
2894 25372 : ojcinfo->rinfo = restrictinfo;
2895 25372 : ojcinfo->sjinfo = sjinfo;
2896 25372 : root->right_join_clauses = lappend(root->right_join_clauses,
2897 : ojcinfo);
2898 25372 : return;
2899 : }
2900 1454 : if (sjinfo->jointype == JOIN_FULL)
2901 : {
2902 : /* FULL JOIN (above tests cannot match in this case) */
2903 1234 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
2904 :
2905 1234 : ojcinfo->rinfo = restrictinfo;
2906 1234 : ojcinfo->sjinfo = sjinfo;
2907 1234 : root->full_join_clauses = lappend(root->full_join_clauses,
2908 : ojcinfo);
2909 1234 : 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 678 : initialize_mergeclause_eclasses(root, restrictinfo);
2917 : }
2918 : }
2919 :
2920 : /* No EC special case applies, so push it into the clause lists */
2921 159838 : 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 426384 : 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 426384 : forced_null_var = find_forced_null_var(clause);
2942 426384 : if (forced_null_var == NULL)
2943 423880 : 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 2504 : if (forced_null_var->varnullingrels == NULL)
2952 1372 : return false;
2953 :
2954 1288 : foreach(lc, root->join_info_list)
2955 : {
2956 1176 : 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 2196 : if (sjinfo->jointype == JOIN_ANTI && sjinfo->ojrelid != 0 &&
2964 1020 : bms_is_member(sjinfo->ojrelid, forced_null_var->varnullingrels))
2965 1020 : 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 361816 : add_base_clause_to_rel(PlannerInfo *root, Index relid,
2981 : RestrictInfo *restrictinfo)
2982 : {
2983 361816 : RelOptInfo *rel = find_base_rel(root, relid);
2984 361816 : 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 361816 : if (!rte->inh || rte->relkind == RELKIND_PARTITIONED_TABLE)
3004 : {
3005 : /* Don't add the clause if it is always true */
3006 360062 : if (restriction_is_always_true(root, restrictinfo))
3007 344 : 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 359718 : if (restriction_is_always_false(root, restrictinfo))
3020 : {
3021 18 : int save_rinfo_serial = restrictinfo->rinfo_serial;
3022 18 : int save_last_rinfo_serial = root->last_rinfo_serial;
3023 :
3024 18 : restrictinfo = make_restrictinfo(root,
3025 18 : (Expr *) makeBoolConst(false, false),
3026 18 : restrictinfo->is_pushed_down,
3027 18 : restrictinfo->has_clone,
3028 18 : restrictinfo->is_clone,
3029 18 : restrictinfo->pseudoconstant,
3030 : 0, /* security_level */
3031 : restrictinfo->required_relids,
3032 : restrictinfo->incompatible_relids,
3033 : restrictinfo->outer_relids);
3034 18 : restrictinfo->rinfo_serial = save_rinfo_serial;
3035 18 : root->last_rinfo_serial = save_last_rinfo_serial;
3036 : }
3037 : }
3038 :
3039 : /* Add clause to rel's restriction list */
3040 361472 : rel->baserestrictinfo = lappend(rel->baserestrictinfo, restrictinfo);
3041 :
3042 : /* Update security level info */
3043 361472 : 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 9780 : expr_is_nonnullable(PlannerInfo *root, Expr *expr)
3056 : {
3057 : RelOptInfo *rel;
3058 : Var *var;
3059 :
3060 : /* For now only check simple Vars */
3061 9780 : if (!IsA(expr, Var))
3062 568 : return false;
3063 :
3064 9212 : var = (Var *) expr;
3065 :
3066 : /* could the Var be nulled by any outer joins? */
3067 9212 : if (!bms_is_empty(var->varnullingrels))
3068 818 : return false;
3069 :
3070 : /* system columns cannot be NULL */
3071 8394 : if (var->varattno < 0)
3072 24 : return true;
3073 :
3074 : /* is the column defined NOT NULL? */
3075 8370 : rel = find_base_rel(root, var->varno);
3076 16584 : if (var->varattno > 0 &&
3077 8214 : bms_is_member(var->varattno, rel->notnullattnums))
3078 434 : return true;
3079 :
3080 7936 : 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 466310 : restriction_is_always_true(PlannerInfo *root,
3092 : RestrictInfo *restrictinfo)
3093 : {
3094 : /* Check for NullTest qual */
3095 466310 : if (IsA(restrictinfo->clause, NullTest))
3096 : {
3097 10200 : NullTest *nulltest = (NullTest *) restrictinfo->clause;
3098 :
3099 : /* is this NullTest an IS_NOT_NULL qual? */
3100 10200 : if (nulltest->nulltesttype != IS_NOT_NULL)
3101 3070 : return false;
3102 :
3103 7130 : return expr_is_nonnullable(root, nulltest->arg);
3104 : }
3105 :
3106 : /* If it's an OR, check its sub-clauses */
3107 456110 : if (restriction_is_or_clause(restrictinfo))
3108 : {
3109 : ListCell *lc;
3110 :
3111 : Assert(is_orclause(restrictinfo->orclause));
3112 :
3113 : /*
3114 : * if any of the given OR branches is provably always true then the
3115 : * entire condition is true.
3116 : */
3117 27458 : foreach(lc, ((BoolExpr *) restrictinfo->orclause)->args)
3118 : {
3119 19264 : Node *orarg = (Node *) lfirst(lc);
3120 :
3121 19264 : if (!IsA(orarg, RestrictInfo))
3122 2812 : continue;
3123 :
3124 16452 : if (restriction_is_always_true(root, (RestrictInfo *) orarg))
3125 18 : return true;
3126 : }
3127 : }
3128 :
3129 456092 : return false;
3130 : }
3131 :
3132 : /*
3133 : * restriction_is_always_false
3134 : * Check to see if the RestrictInfo is always false.
3135 : *
3136 : * Currently we only check for NullTest quals and OR clauses that include
3137 : * NullTest quals. We may extend it in the future.
3138 : */
3139 : bool
3140 456456 : restriction_is_always_false(PlannerInfo *root,
3141 : RestrictInfo *restrictinfo)
3142 : {
3143 : /* Check for NullTest qual */
3144 456456 : if (IsA(restrictinfo->clause, NullTest))
3145 : {
3146 8744 : NullTest *nulltest = (NullTest *) restrictinfo->clause;
3147 :
3148 : /* is this NullTest an IS_NULL qual? */
3149 8744 : if (nulltest->nulltesttype != IS_NULL)
3150 6094 : return false;
3151 :
3152 2650 : return expr_is_nonnullable(root, nulltest->arg);
3153 : }
3154 :
3155 : /* If it's an OR, check its sub-clauses */
3156 447712 : if (restriction_is_or_clause(restrictinfo))
3157 : {
3158 : ListCell *lc;
3159 :
3160 : Assert(is_orclause(restrictinfo->orclause));
3161 :
3162 : /*
3163 : * Currently, when processing OR expressions, we only return true when
3164 : * all of the OR branches are always false. This could perhaps be
3165 : * expanded to remove OR branches that are provably false. This may
3166 : * be a useful thing to do as it could result in the OR being left
3167 : * with a single arg. That's useful as it would allow the OR
3168 : * condition to be replaced with its single argument which may allow
3169 : * use of an index for faster filtering on the remaining condition.
3170 : */
3171 8236 : foreach(lc, ((BoolExpr *) restrictinfo->orclause)->args)
3172 : {
3173 8224 : Node *orarg = (Node *) lfirst(lc);
3174 :
3175 8224 : if (!IsA(orarg, RestrictInfo) ||
3176 6954 : !restriction_is_always_false(root, (RestrictInfo *) orarg))
3177 8182 : return false;
3178 : }
3179 12 : return true;
3180 : }
3181 :
3182 439518 : return false;
3183 : }
3184 :
3185 : /*
3186 : * distribute_restrictinfo_to_rels
3187 : * Push a completed RestrictInfo into the proper restriction or join
3188 : * clause list(s).
3189 : *
3190 : * This is the last step of distribute_qual_to_rels() for ordinary qual
3191 : * clauses. Clauses that are interesting for equivalence-class processing
3192 : * are diverted to the EC machinery, but may ultimately get fed back here.
3193 : */
3194 : void
3195 423534 : distribute_restrictinfo_to_rels(PlannerInfo *root,
3196 : RestrictInfo *restrictinfo)
3197 : {
3198 423534 : Relids relids = restrictinfo->required_relids;
3199 :
3200 423534 : if (!bms_is_empty(relids))
3201 : {
3202 : int relid;
3203 :
3204 423534 : if (bms_get_singleton_member(relids, &relid))
3205 : {
3206 : /*
3207 : * There is only one relation participating in the clause, so it
3208 : * is a restriction clause for that relation.
3209 : */
3210 361816 : add_base_clause_to_rel(root, relid, restrictinfo);
3211 : }
3212 : else
3213 : {
3214 : /*
3215 : * The clause is a join clause, since there is more than one rel
3216 : * in its relid set.
3217 : */
3218 :
3219 : /*
3220 : * Check for hashjoinable operators. (We don't bother setting the
3221 : * hashjoin info except in true join clauses.)
3222 : */
3223 61718 : check_hashjoinable(restrictinfo);
3224 :
3225 : /*
3226 : * Likewise, check if the clause is suitable to be used with a
3227 : * Memoize node to cache inner tuples during a parameterized
3228 : * nested loop.
3229 : */
3230 61718 : check_memoizable(restrictinfo);
3231 :
3232 : /*
3233 : * Add clause to the join lists of all the relevant relations.
3234 : */
3235 61718 : add_join_clause_to_rels(root, restrictinfo, relids);
3236 : }
3237 : }
3238 : else
3239 : {
3240 : /*
3241 : * clause references no rels, and therefore we have no place to attach
3242 : * it. Shouldn't get here if callers are working properly.
3243 : */
3244 0 : elog(ERROR, "cannot cope with variable-free clause");
3245 : }
3246 423534 : }
3247 :
3248 : /*
3249 : * process_implied_equality
3250 : * Create a restrictinfo item that says "item1 op item2", and push it
3251 : * into the appropriate lists. (In practice opno is always a btree
3252 : * equality operator.)
3253 : *
3254 : * "qualscope" is the nominal syntactic level to impute to the restrictinfo.
3255 : * This must contain at least all the rels used in the expressions, but it
3256 : * is used only to set the qual application level when both exprs are
3257 : * variable-free. (Hence, it should usually match the join domain in which
3258 : * the clause applies.) Otherwise the qual is applied at the lowest join
3259 : * level that provides all its variables.
3260 : *
3261 : * "security_level" is the security level to assign to the new restrictinfo.
3262 : *
3263 : * "both_const" indicates whether both items are known pseudo-constant;
3264 : * in this case it is worth applying eval_const_expressions() in case we
3265 : * can produce constant TRUE or constant FALSE. (Otherwise it's not,
3266 : * because the expressions went through eval_const_expressions already.)
3267 : *
3268 : * Returns the generated RestrictInfo, if any. The result will be NULL
3269 : * if both_const is true and we successfully reduced the clause to
3270 : * constant TRUE.
3271 : *
3272 : * Note: this function will copy item1 and item2, but it is caller's
3273 : * responsibility to make sure that the Relids parameters are fresh copies
3274 : * not shared with other uses.
3275 : *
3276 : * Note: we do not do initialize_mergeclause_eclasses() here. It is
3277 : * caller's responsibility that left_ec/right_ec be set as necessary.
3278 : */
3279 : RestrictInfo *
3280 36904 : process_implied_equality(PlannerInfo *root,
3281 : Oid opno,
3282 : Oid collation,
3283 : Expr *item1,
3284 : Expr *item2,
3285 : Relids qualscope,
3286 : Index security_level,
3287 : bool both_const)
3288 : {
3289 : RestrictInfo *restrictinfo;
3290 : Node *clause;
3291 : Relids relids;
3292 36904 : bool pseudoconstant = false;
3293 :
3294 : /*
3295 : * Build the new clause. Copy to ensure it shares no substructure with
3296 : * original (this is necessary in case there are subselects in there...)
3297 : */
3298 36904 : clause = (Node *) make_opclause(opno,
3299 : BOOLOID, /* opresulttype */
3300 : false, /* opretset */
3301 36904 : copyObject(item1),
3302 36904 : copyObject(item2),
3303 : InvalidOid,
3304 : collation);
3305 :
3306 : /* If both constant, try to reduce to a boolean constant. */
3307 36904 : if (both_const)
3308 : {
3309 126 : clause = eval_const_expressions(root, clause);
3310 :
3311 : /* If we produced const TRUE, just drop the clause */
3312 126 : if (clause && IsA(clause, Const))
3313 : {
3314 126 : Const *cclause = (Const *) clause;
3315 :
3316 : Assert(cclause->consttype == BOOLOID);
3317 126 : if (!cclause->constisnull && DatumGetBool(cclause->constvalue))
3318 0 : return NULL;
3319 : }
3320 : }
3321 :
3322 : /*
3323 : * The rest of this is a very cut-down version of distribute_qual_to_rels.
3324 : * We can skip most of the work therein, but there are a couple of special
3325 : * cases we still have to handle.
3326 : *
3327 : * Retrieve all relids mentioned within the possibly-simplified clause.
3328 : */
3329 36904 : relids = pull_varnos(root, clause);
3330 : Assert(bms_is_subset(relids, qualscope));
3331 :
3332 : /*
3333 : * If the clause is variable-free, our normal heuristic for pushing it
3334 : * down to just the mentioned rels doesn't work, because there are none.
3335 : * Apply it as a gating qual at the appropriate level (see comments for
3336 : * get_join_domain_min_rels).
3337 : */
3338 36904 : if (bms_is_empty(relids))
3339 : {
3340 : /* eval at join domain's safe level */
3341 126 : relids = get_join_domain_min_rels(root, qualscope);
3342 : /* mark as gating qual */
3343 126 : pseudoconstant = true;
3344 : /* tell createplan.c to check for gating quals */
3345 126 : root->hasPseudoConstantQuals = true;
3346 : }
3347 :
3348 : /*
3349 : * Build the RestrictInfo node itself.
3350 : */
3351 36904 : restrictinfo = make_restrictinfo(root,
3352 : (Expr *) clause,
3353 : true, /* is_pushed_down */
3354 : false, /* !has_clone */
3355 : false, /* !is_clone */
3356 : pseudoconstant,
3357 : security_level,
3358 : relids,
3359 : NULL, /* incompatible_relids */
3360 : NULL); /* outer_relids */
3361 :
3362 : /*
3363 : * If it's a join clause, add vars used in the clause to targetlists of
3364 : * their relations, so that they will be emitted by the plan nodes that
3365 : * scan those relations (else they won't be available at the join node!).
3366 : *
3367 : * Typically, we'd have already done this when the component expressions
3368 : * were first seen by distribute_qual_to_rels; but it is possible that
3369 : * some of the Vars could have missed having that done because they only
3370 : * appeared in single-relation clauses originally. So do it here for
3371 : * safety.
3372 : *
3373 : * See also rebuild_joinclause_attr_needed, which has to partially repeat
3374 : * this work after removal of an outer join. (Since we will put this
3375 : * clause into the joininfo lists, that function needn't do any extra work
3376 : * to find it.)
3377 : */
3378 36904 : if (bms_membership(relids) == BMS_MULTIPLE)
3379 : {
3380 60 : List *vars = pull_var_clause(clause,
3381 : PVC_RECURSE_AGGREGATES |
3382 : PVC_RECURSE_WINDOWFUNCS |
3383 : PVC_INCLUDE_PLACEHOLDERS);
3384 :
3385 60 : add_vars_to_targetlist(root, vars, relids);
3386 60 : list_free(vars);
3387 : }
3388 :
3389 : /*
3390 : * Check mergejoinability. This will usually succeed, since the op came
3391 : * from an EquivalenceClass; but we could have reduced the original clause
3392 : * to a constant.
3393 : */
3394 36904 : check_mergejoinable(restrictinfo);
3395 :
3396 : /*
3397 : * Note we don't do initialize_mergeclause_eclasses(); the caller can
3398 : * handle that much more cheaply than we can. It's okay to call
3399 : * distribute_restrictinfo_to_rels() before that happens.
3400 : */
3401 :
3402 : /*
3403 : * Push the new clause into all the appropriate restrictinfo lists.
3404 : */
3405 36904 : distribute_restrictinfo_to_rels(root, restrictinfo);
3406 :
3407 36904 : return restrictinfo;
3408 : }
3409 :
3410 : /*
3411 : * build_implied_join_equality --- build a RestrictInfo for a derived equality
3412 : *
3413 : * This overlaps the functionality of process_implied_equality(), but we
3414 : * must not push the RestrictInfo into the joininfo tree.
3415 : *
3416 : * Note: this function will copy item1 and item2, but it is caller's
3417 : * responsibility to make sure that the Relids parameters are fresh copies
3418 : * not shared with other uses.
3419 : *
3420 : * Note: we do not do initialize_mergeclause_eclasses() here. It is
3421 : * caller's responsibility that left_ec/right_ec be set as necessary.
3422 : */
3423 : RestrictInfo *
3424 63198 : build_implied_join_equality(PlannerInfo *root,
3425 : Oid opno,
3426 : Oid collation,
3427 : Expr *item1,
3428 : Expr *item2,
3429 : Relids qualscope,
3430 : Index security_level)
3431 : {
3432 : RestrictInfo *restrictinfo;
3433 : Expr *clause;
3434 :
3435 : /*
3436 : * Build the new clause. Copy to ensure it shares no substructure with
3437 : * original (this is necessary in case there are subselects in there...)
3438 : */
3439 63198 : clause = make_opclause(opno,
3440 : BOOLOID, /* opresulttype */
3441 : false, /* opretset */
3442 63198 : copyObject(item1),
3443 63198 : copyObject(item2),
3444 : InvalidOid,
3445 : collation);
3446 :
3447 : /*
3448 : * Build the RestrictInfo node itself.
3449 : */
3450 63198 : restrictinfo = make_restrictinfo(root,
3451 : clause,
3452 : true, /* is_pushed_down */
3453 : false, /* !has_clone */
3454 : false, /* !is_clone */
3455 : false, /* pseudoconstant */
3456 : security_level, /* security_level */
3457 : qualscope, /* required_relids */
3458 : NULL, /* incompatible_relids */
3459 : NULL); /* outer_relids */
3460 :
3461 : /* Set mergejoinability/hashjoinability flags */
3462 63198 : check_mergejoinable(restrictinfo);
3463 63198 : check_hashjoinable(restrictinfo);
3464 63198 : check_memoizable(restrictinfo);
3465 :
3466 63198 : return restrictinfo;
3467 : }
3468 :
3469 : /*
3470 : * get_join_domain_min_rels
3471 : * Identify the appropriate join level for derived quals belonging
3472 : * to the join domain with the given relids.
3473 : *
3474 : * When we derive a pseudoconstant (Var-free) clause from an EquivalenceClass,
3475 : * we'd ideally apply the clause at the top level of the EC's join domain.
3476 : * However, if there are any outer joins inside that domain that get commuted
3477 : * with joins outside it, that leads to not finding a correct place to apply
3478 : * the clause. Instead, remove any lower outer joins from the relid set,
3479 : * and apply the clause to just the remaining rels. This still results in a
3480 : * correct answer, since if the clause produces FALSE then the LHS of these
3481 : * joins will be empty leading to an empty join result.
3482 : *
3483 : * However, there's no need to remove outer joins if this is the top-level
3484 : * join domain of the query, since then there's nothing else to commute with.
3485 : *
3486 : * Note: it's tempting to use this in distribute_qual_to_rels where it's
3487 : * dealing with pseudoconstant quals; but we can't because the necessary
3488 : * SpecialJoinInfos aren't all formed at that point.
3489 : *
3490 : * The result is always freshly palloc'd; we do not modify domain_relids.
3491 : */
3492 : static Relids
3493 126 : get_join_domain_min_rels(PlannerInfo *root, Relids domain_relids)
3494 : {
3495 126 : Relids result = bms_copy(domain_relids);
3496 : ListCell *lc;
3497 :
3498 : /* Top-level join domain? */
3499 126 : if (bms_equal(result, root->all_query_rels))
3500 60 : return result;
3501 :
3502 : /* Nope, look for lower outer joins that could potentially commute out */
3503 138 : foreach(lc, root->join_info_list)
3504 : {
3505 72 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
3506 :
3507 144 : if (sjinfo->jointype == JOIN_LEFT &&
3508 72 : bms_is_member(sjinfo->ojrelid, result))
3509 : {
3510 6 : result = bms_del_member(result, sjinfo->ojrelid);
3511 6 : result = bms_del_members(result, sjinfo->syn_righthand);
3512 : }
3513 : }
3514 66 : return result;
3515 : }
3516 :
3517 :
3518 : /*
3519 : * rebuild_joinclause_attr_needed
3520 : * Put back attr_needed bits for Vars/PHVs needed for join clauses.
3521 : *
3522 : * This is used to rebuild attr_needed/ph_needed sets after removal of a
3523 : * useless outer join. It should match what distribute_qual_to_rels did,
3524 : * except that we call add_vars_to_attr_needed not add_vars_to_targetlist.
3525 : */
3526 : void
3527 9568 : rebuild_joinclause_attr_needed(PlannerInfo *root)
3528 : {
3529 : /*
3530 : * We must examine all join clauses, but there's no value in processing
3531 : * any join clause more than once. So it's slightly annoying that we have
3532 : * to find them via the per-base-relation joininfo lists. Avoid duplicate
3533 : * processing by tracking the rinfo_serial numbers of join clauses we've
3534 : * already seen. (This doesn't work for is_clone clauses, so we must
3535 : * waste effort on them.)
3536 : */
3537 9568 : Bitmapset *seen_serials = NULL;
3538 : Index rti;
3539 :
3540 : /* Scan all baserels for join clauses */
3541 60584 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
3542 : {
3543 51016 : RelOptInfo *brel = root->simple_rel_array[rti];
3544 : ListCell *lc;
3545 :
3546 51016 : if (brel == NULL)
3547 34458 : continue;
3548 16558 : if (brel->reloptkind != RELOPT_BASEREL)
3549 0 : continue;
3550 :
3551 25306 : foreach(lc, brel->joininfo)
3552 : {
3553 8748 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3554 8748 : Relids relids = rinfo->required_relids;
3555 :
3556 8748 : if (!rinfo->is_clone) /* else serial number is not unique */
3557 : {
3558 8628 : if (bms_is_member(rinfo->rinfo_serial, seen_serials))
3559 4662 : continue; /* saw it already */
3560 3966 : seen_serials = bms_add_member(seen_serials,
3561 : rinfo->rinfo_serial);
3562 : }
3563 :
3564 4086 : if (bms_membership(relids) == BMS_MULTIPLE)
3565 : {
3566 4086 : List *vars = pull_var_clause((Node *) rinfo->clause,
3567 : PVC_RECURSE_AGGREGATES |
3568 : PVC_RECURSE_WINDOWFUNCS |
3569 : PVC_INCLUDE_PLACEHOLDERS);
3570 : Relids where_needed;
3571 :
3572 4086 : if (rinfo->is_clone)
3573 120 : where_needed = bms_intersect(relids, root->all_baserels);
3574 : else
3575 3966 : where_needed = relids;
3576 4086 : add_vars_to_attr_needed(root, vars, where_needed);
3577 4086 : list_free(vars);
3578 : }
3579 : }
3580 : }
3581 9568 : }
3582 :
3583 :
3584 : /*
3585 : * match_foreign_keys_to_quals
3586 : * Match foreign-key constraints to equivalence classes and join quals
3587 : *
3588 : * The idea here is to see which query join conditions match equality
3589 : * constraints of a foreign-key relationship. For such join conditions,
3590 : * we can use the FK semantics to make selectivity estimates that are more
3591 : * reliable than estimating from statistics, especially for multiple-column
3592 : * FKs, where the normal assumption of independent conditions tends to fail.
3593 : *
3594 : * In this function we annotate the ForeignKeyOptInfos in root->fkey_list
3595 : * with info about which eclasses and join qual clauses they match, and
3596 : * discard any ForeignKeyOptInfos that are irrelevant for the query.
3597 : */
3598 : void
3599 290722 : match_foreign_keys_to_quals(PlannerInfo *root)
3600 : {
3601 290722 : List *newlist = NIL;
3602 : ListCell *lc;
3603 :
3604 292430 : foreach(lc, root->fkey_list)
3605 : {
3606 1708 : ForeignKeyOptInfo *fkinfo = (ForeignKeyOptInfo *) lfirst(lc);
3607 : RelOptInfo *con_rel;
3608 : RelOptInfo *ref_rel;
3609 : int colno;
3610 :
3611 : /*
3612 : * Either relid might identify a rel that is in the query's rtable but
3613 : * isn't referenced by the jointree, or has been removed by join
3614 : * removal, so that it won't have a RelOptInfo. Hence don't use
3615 : * find_base_rel() here. We can ignore such FKs.
3616 : */
3617 1708 : if (fkinfo->con_relid >= root->simple_rel_array_size ||
3618 1708 : fkinfo->ref_relid >= root->simple_rel_array_size)
3619 0 : continue; /* just paranoia */
3620 1708 : con_rel = root->simple_rel_array[fkinfo->con_relid];
3621 1708 : if (con_rel == NULL)
3622 0 : continue;
3623 1708 : ref_rel = root->simple_rel_array[fkinfo->ref_relid];
3624 1708 : if (ref_rel == NULL)
3625 24 : continue;
3626 :
3627 : /*
3628 : * Ignore FK unless both rels are baserels. This gets rid of FKs that
3629 : * link to inheritance child rels (otherrels).
3630 : */
3631 1684 : if (con_rel->reloptkind != RELOPT_BASEREL ||
3632 1684 : ref_rel->reloptkind != RELOPT_BASEREL)
3633 0 : continue;
3634 :
3635 : /*
3636 : * Scan the columns and try to match them to eclasses and quals.
3637 : *
3638 : * Note: for simple inner joins, any match should be in an eclass.
3639 : * "Loose" quals that syntactically match an FK equality must have
3640 : * been rejected for EC status because they are outer-join quals or
3641 : * similar. We can still consider them to match the FK.
3642 : */
3643 3864 : for (colno = 0; colno < fkinfo->nkeys; colno++)
3644 : {
3645 : EquivalenceClass *ec;
3646 : AttrNumber con_attno,
3647 : ref_attno;
3648 : Oid fpeqop;
3649 : ListCell *lc2;
3650 :
3651 2180 : ec = match_eclasses_to_foreign_key_col(root, fkinfo, colno);
3652 : /* Don't bother looking for loose quals if we got an EC match */
3653 2180 : if (ec != NULL)
3654 : {
3655 342 : fkinfo->nmatched_ec++;
3656 342 : if (ec->ec_has_const)
3657 74 : fkinfo->nconst_ec++;
3658 342 : continue;
3659 : }
3660 :
3661 : /*
3662 : * Scan joininfo list for relevant clauses. Either rel's joininfo
3663 : * list would do equally well; we use con_rel's.
3664 : */
3665 1838 : con_attno = fkinfo->conkey[colno];
3666 1838 : ref_attno = fkinfo->confkey[colno];
3667 1838 : fpeqop = InvalidOid; /* we'll look this up only if needed */
3668 :
3669 4740 : foreach(lc2, con_rel->joininfo)
3670 : {
3671 2902 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc2);
3672 2902 : OpExpr *clause = (OpExpr *) rinfo->clause;
3673 : Var *leftvar;
3674 : Var *rightvar;
3675 :
3676 : /* Only binary OpExprs are useful for consideration */
3677 5804 : if (!IsA(clause, OpExpr) ||
3678 2902 : list_length(clause->args) != 2)
3679 0 : continue;
3680 2902 : leftvar = (Var *) get_leftop((Expr *) clause);
3681 2902 : rightvar = (Var *) get_rightop((Expr *) clause);
3682 :
3683 : /* Operands must be Vars, possibly with RelabelType */
3684 3148 : while (leftvar && IsA(leftvar, RelabelType))
3685 246 : leftvar = (Var *) ((RelabelType *) leftvar)->arg;
3686 2902 : if (!(leftvar && IsA(leftvar, Var)))
3687 0 : continue;
3688 3130 : while (rightvar && IsA(rightvar, RelabelType))
3689 228 : rightvar = (Var *) ((RelabelType *) rightvar)->arg;
3690 2902 : if (!(rightvar && IsA(rightvar, Var)))
3691 30 : continue;
3692 :
3693 : /* Now try to match the vars to the current foreign key cols */
3694 2872 : if (fkinfo->ref_relid == leftvar->varno &&
3695 2746 : ref_attno == leftvar->varattno &&
3696 1580 : fkinfo->con_relid == rightvar->varno &&
3697 1580 : con_attno == rightvar->varattno)
3698 : {
3699 : /* Vars match, but is it the right operator? */
3700 1502 : if (clause->opno == fkinfo->conpfeqop[colno])
3701 : {
3702 1502 : fkinfo->rinfos[colno] = lappend(fkinfo->rinfos[colno],
3703 : rinfo);
3704 1502 : fkinfo->nmatched_ri++;
3705 : }
3706 : }
3707 1370 : else if (fkinfo->ref_relid == rightvar->varno &&
3708 90 : ref_attno == rightvar->varattno &&
3709 36 : fkinfo->con_relid == leftvar->varno &&
3710 36 : con_attno == leftvar->varattno)
3711 : {
3712 : /*
3713 : * Reverse match, must check commutator operator. Look it
3714 : * up if we didn't already. (In the worst case we might
3715 : * do multiple lookups here, but that would require an FK
3716 : * equality operator without commutator, which is
3717 : * unlikely.)
3718 : */
3719 36 : if (!OidIsValid(fpeqop))
3720 36 : fpeqop = get_commutator(fkinfo->conpfeqop[colno]);
3721 36 : if (clause->opno == fpeqop)
3722 : {
3723 36 : fkinfo->rinfos[colno] = lappend(fkinfo->rinfos[colno],
3724 : rinfo);
3725 36 : fkinfo->nmatched_ri++;
3726 : }
3727 : }
3728 : }
3729 : /* If we found any matching loose quals, count col as matched */
3730 1838 : if (fkinfo->rinfos[colno])
3731 1538 : fkinfo->nmatched_rcols++;
3732 : }
3733 :
3734 : /*
3735 : * Currently, we drop multicolumn FKs that aren't fully matched to the
3736 : * query. Later we might figure out how to derive some sort of
3737 : * estimate from them, in which case this test should be weakened to
3738 : * "if ((fkinfo->nmatched_ec + fkinfo->nmatched_rcols) > 0)".
3739 : */
3740 1684 : if ((fkinfo->nmatched_ec + fkinfo->nmatched_rcols) == fkinfo->nkeys)
3741 1408 : newlist = lappend(newlist, fkinfo);
3742 : }
3743 : /* Replace fkey_list, thereby discarding any useless entries */
3744 290722 : root->fkey_list = newlist;
3745 290722 : }
3746 :
3747 :
3748 : /*****************************************************************************
3749 : *
3750 : * CHECKS FOR MERGEJOINABLE AND HASHJOINABLE CLAUSES
3751 : *
3752 : *****************************************************************************/
3753 :
3754 : /*
3755 : * check_mergejoinable
3756 : * If the restrictinfo's clause is mergejoinable, set the mergejoin
3757 : * info fields in the restrictinfo.
3758 : *
3759 : * Currently, we support mergejoin for binary opclauses where
3760 : * the operator is a mergejoinable operator. The arguments can be
3761 : * anything --- as long as there are no volatile functions in them.
3762 : */
3763 : static void
3764 577808 : check_mergejoinable(RestrictInfo *restrictinfo)
3765 : {
3766 577808 : Expr *clause = restrictinfo->clause;
3767 : Oid opno;
3768 : Node *leftarg;
3769 :
3770 577808 : if (restrictinfo->pseudoconstant)
3771 9486 : return;
3772 568322 : if (!is_opclause(clause))
3773 76138 : return;
3774 492184 : if (list_length(((OpExpr *) clause)->args) != 2)
3775 24 : return;
3776 :
3777 492160 : opno = ((OpExpr *) clause)->opno;
3778 492160 : leftarg = linitial(((OpExpr *) clause)->args);
3779 :
3780 492160 : if (op_mergejoinable(opno, exprType(leftarg)) &&
3781 419006 : !contain_volatile_functions((Node *) restrictinfo))
3782 418998 : restrictinfo->mergeopfamilies = get_mergejoin_opfamilies(opno);
3783 :
3784 : /*
3785 : * Note: op_mergejoinable is just a hint; if we fail to find the operator
3786 : * in any btree opfamilies, mergeopfamilies remains NIL and so the clause
3787 : * is not treated as mergejoinable.
3788 : */
3789 : }
3790 :
3791 : /*
3792 : * check_hashjoinable
3793 : * If the restrictinfo's clause is hashjoinable, set the hashjoin
3794 : * info fields in the restrictinfo.
3795 : *
3796 : * Currently, we support hashjoin for binary opclauses where
3797 : * the operator is a hashjoinable operator. The arguments can be
3798 : * anything --- as long as there are no volatile functions in them.
3799 : */
3800 : static void
3801 124916 : check_hashjoinable(RestrictInfo *restrictinfo)
3802 : {
3803 124916 : Expr *clause = restrictinfo->clause;
3804 : Oid opno;
3805 : Node *leftarg;
3806 :
3807 124916 : if (restrictinfo->pseudoconstant)
3808 3046 : return;
3809 121870 : if (!is_opclause(clause))
3810 6372 : return;
3811 115498 : if (list_length(((OpExpr *) clause)->args) != 2)
3812 0 : return;
3813 :
3814 115498 : opno = ((OpExpr *) clause)->opno;
3815 115498 : leftarg = linitial(((OpExpr *) clause)->args);
3816 :
3817 115498 : if (op_hashjoinable(opno, exprType(leftarg)) &&
3818 112348 : !contain_volatile_functions((Node *) restrictinfo))
3819 112340 : restrictinfo->hashjoinoperator = opno;
3820 : }
3821 :
3822 : /*
3823 : * check_memoizable
3824 : * If the restrictinfo's clause is suitable to be used for a Memoize node,
3825 : * set the left_hasheqoperator and right_hasheqoperator to the hash equality
3826 : * operator that will be needed during caching.
3827 : */
3828 : static void
3829 124916 : check_memoizable(RestrictInfo *restrictinfo)
3830 : {
3831 : TypeCacheEntry *typentry;
3832 124916 : Expr *clause = restrictinfo->clause;
3833 : Oid lefttype;
3834 : Oid righttype;
3835 :
3836 124916 : if (restrictinfo->pseudoconstant)
3837 3046 : return;
3838 121870 : if (!is_opclause(clause))
3839 6372 : return;
3840 115498 : if (list_length(((OpExpr *) clause)->args) != 2)
3841 0 : return;
3842 :
3843 115498 : lefttype = exprType(linitial(((OpExpr *) clause)->args));
3844 :
3845 115498 : typentry = lookup_type_cache(lefttype, TYPECACHE_HASH_PROC |
3846 : TYPECACHE_EQ_OPR);
3847 :
3848 115498 : if (OidIsValid(typentry->hash_proc) && OidIsValid(typentry->eq_opr))
3849 115090 : restrictinfo->left_hasheqoperator = typentry->eq_opr;
3850 :
3851 115498 : righttype = exprType(lsecond(((OpExpr *) clause)->args));
3852 :
3853 : /*
3854 : * Lookup the right type, unless it's the same as the left type, in which
3855 : * case typentry is already pointing to the required TypeCacheEntry.
3856 : */
3857 115498 : if (lefttype != righttype)
3858 1826 : typentry = lookup_type_cache(righttype, TYPECACHE_HASH_PROC |
3859 : TYPECACHE_EQ_OPR);
3860 :
3861 115498 : if (OidIsValid(typentry->hash_proc) && OidIsValid(typentry->eq_opr))
3862 114892 : restrictinfo->right_hasheqoperator = typentry->eq_opr;
3863 : }
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