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 "access/nbtree.h"
18 : #include "catalog/pg_constraint.h"
19 : #include "catalog/pg_type.h"
20 : #include "nodes/makefuncs.h"
21 : #include "nodes/nodeFuncs.h"
22 : #include "optimizer/clauses.h"
23 : #include "optimizer/cost.h"
24 : #include "optimizer/inherit.h"
25 : #include "optimizer/joininfo.h"
26 : #include "optimizer/optimizer.h"
27 : #include "optimizer/pathnode.h"
28 : #include "optimizer/paths.h"
29 : #include "optimizer/placeholder.h"
30 : #include "optimizer/planmain.h"
31 : #include "optimizer/planner.h"
32 : #include "optimizer/restrictinfo.h"
33 : #include "parser/analyze.h"
34 : #include "rewrite/rewriteManip.h"
35 : #include "utils/lsyscache.h"
36 : #include "utils/rel.h"
37 : #include "utils/typcache.h"
38 :
39 : /* These parameters are set by GUC */
40 : int from_collapse_limit;
41 : int join_collapse_limit;
42 :
43 :
44 : /*
45 : * deconstruct_jointree requires multiple passes over the join tree, because we
46 : * need to finish computing JoinDomains before we start distributing quals.
47 : * As long as we have to do that, other information such as the relevant
48 : * qualscopes might as well be computed in the first pass too.
49 : *
50 : * deconstruct_recurse recursively examines the join tree and builds a List
51 : * (in depth-first traversal order) of JoinTreeItem structs, which are then
52 : * processed iteratively by deconstruct_distribute. If there are outer
53 : * joins, non-degenerate outer join clauses are processed in a third pass
54 : * deconstruct_distribute_oj_quals.
55 : *
56 : * The JoinTreeItem structs themselves can be freed at the end of
57 : * deconstruct_jointree, but do not modify or free their substructure,
58 : * as the relid sets may also be pointed to by RestrictInfo and
59 : * SpecialJoinInfo nodes.
60 : */
61 : typedef struct JoinTreeItem
62 : {
63 : /* Fields filled during deconstruct_recurse: */
64 : Node *jtnode; /* jointree node to examine */
65 : JoinDomain *jdomain; /* join domain for its ON/WHERE clauses */
66 : struct JoinTreeItem *jti_parent; /* JoinTreeItem for this node's
67 : * parent, or NULL if it's the top */
68 : Relids qualscope; /* base+OJ Relids syntactically included in
69 : * this jointree node */
70 : Relids inner_join_rels; /* base+OJ Relids syntactically included
71 : * in inner joins appearing at or below
72 : * this jointree node */
73 : Relids left_rels; /* if join node, Relids of the left side */
74 : Relids right_rels; /* if join node, Relids of the right side */
75 : Relids nonnullable_rels; /* if outer join, Relids of the
76 : * non-nullable side */
77 : /* Fields filled during deconstruct_distribute: */
78 : SpecialJoinInfo *sjinfo; /* if outer join, its SpecialJoinInfo */
79 : List *oj_joinclauses; /* outer join quals not yet distributed */
80 : List *lateral_clauses; /* quals postponed from children due to
81 : * lateral references */
82 : } JoinTreeItem;
83 :
84 :
85 : static bool is_partial_agg_memory_risky(PlannerInfo *root);
86 : static void create_agg_clause_infos(PlannerInfo *root);
87 : static void create_grouping_expr_infos(PlannerInfo *root);
88 : static EquivalenceClass *get_eclass_for_sortgroupclause(PlannerInfo *root,
89 : SortGroupClause *sgc,
90 : Expr *expr);
91 : static void extract_lateral_references(PlannerInfo *root, RelOptInfo *brel,
92 : Index rtindex);
93 : static List *deconstruct_recurse(PlannerInfo *root, Node *jtnode,
94 : JoinDomain *parent_domain,
95 : JoinTreeItem *parent_jtitem,
96 : List **item_list);
97 : static void deconstruct_distribute(PlannerInfo *root, JoinTreeItem *jtitem);
98 : static void process_security_barrier_quals(PlannerInfo *root,
99 : int rti, JoinTreeItem *jtitem);
100 : static void mark_rels_nulled_by_join(PlannerInfo *root, Index ojrelid,
101 : Relids lower_rels);
102 : static SpecialJoinInfo *make_outerjoininfo(PlannerInfo *root,
103 : Relids left_rels, Relids right_rels,
104 : Relids inner_join_rels,
105 : JoinType jointype, Index ojrelid,
106 : List *clause);
107 : static void compute_semijoin_info(PlannerInfo *root, SpecialJoinInfo *sjinfo,
108 : List *clause);
109 : static void deconstruct_distribute_oj_quals(PlannerInfo *root,
110 : List *jtitems,
111 : JoinTreeItem *jtitem);
112 : static void distribute_quals_to_rels(PlannerInfo *root, List *clauses,
113 : JoinTreeItem *jtitem,
114 : SpecialJoinInfo *sjinfo,
115 : Index security_level,
116 : Relids qualscope,
117 : Relids ojscope,
118 : Relids outerjoin_nonnullable,
119 : Relids incompatible_relids,
120 : bool allow_equivalence,
121 : bool has_clone,
122 : bool is_clone,
123 : List **postponed_oj_qual_list);
124 : static void distribute_qual_to_rels(PlannerInfo *root, Node *clause,
125 : JoinTreeItem *jtitem,
126 : SpecialJoinInfo *sjinfo,
127 : Index security_level,
128 : Relids qualscope,
129 : Relids ojscope,
130 : Relids outerjoin_nonnullable,
131 : Relids incompatible_relids,
132 : bool allow_equivalence,
133 : bool has_clone,
134 : bool is_clone,
135 : List **postponed_oj_qual_list);
136 : static bool check_redundant_nullability_qual(PlannerInfo *root, Node *clause);
137 : static Relids get_join_domain_min_rels(PlannerInfo *root, Relids domain_relids);
138 : static void check_mergejoinable(RestrictInfo *restrictinfo);
139 : static void check_hashjoinable(RestrictInfo *restrictinfo);
140 : static void check_memoizable(RestrictInfo *restrictinfo);
141 :
142 :
143 : /*****************************************************************************
144 : *
145 : * JOIN TREES
146 : *
147 : *****************************************************************************/
148 :
149 : /*
150 : * add_base_rels_to_query
151 : *
152 : * Scan the query's jointree and create baserel RelOptInfos for all
153 : * the base relations (e.g., table, subquery, and function RTEs)
154 : * appearing in the jointree.
155 : *
156 : * The initial invocation must pass root->parse->jointree as the value of
157 : * jtnode. Internally, the function recurses through the jointree.
158 : *
159 : * At the end of this process, there should be one baserel RelOptInfo for
160 : * every non-join RTE that is used in the query. Some of the baserels
161 : * may be appendrel parents, which will require additional "otherrel"
162 : * RelOptInfos for their member rels, but those are added later.
163 : */
164 : void
165 943128 : add_base_rels_to_query(PlannerInfo *root, Node *jtnode)
166 : {
167 943128 : if (jtnode == NULL)
168 0 : return;
169 943128 : if (IsA(jtnode, RangeTblRef))
170 : {
171 490452 : int varno = ((RangeTblRef *) jtnode)->rtindex;
172 :
173 490452 : (void) build_simple_rel(root, varno, NULL);
174 : }
175 452676 : else if (IsA(jtnode, FromExpr))
176 : {
177 351664 : FromExpr *f = (FromExpr *) jtnode;
178 : ListCell *l;
179 :
180 753528 : foreach(l, f->fromlist)
181 401882 : add_base_rels_to_query(root, lfirst(l));
182 : }
183 101012 : else if (IsA(jtnode, JoinExpr))
184 : {
185 101012 : JoinExpr *j = (JoinExpr *) jtnode;
186 :
187 101012 : add_base_rels_to_query(root, j->larg);
188 101012 : add_base_rels_to_query(root, j->rarg);
189 : }
190 : else
191 0 : elog(ERROR, "unrecognized node type: %d",
192 : (int) nodeTag(jtnode));
193 : }
194 :
195 : /*
196 : * add_other_rels_to_query
197 : * create "otherrel" RelOptInfos for the children of appendrel baserels
198 : *
199 : * At the end of this process, there should be RelOptInfos for all relations
200 : * that will be scanned by the query.
201 : */
202 : void
203 339204 : add_other_rels_to_query(PlannerInfo *root)
204 : {
205 : int rti;
206 :
207 1039618 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
208 : {
209 700416 : RelOptInfo *rel = root->simple_rel_array[rti];
210 700416 : RangeTblEntry *rte = root->simple_rte_array[rti];
211 :
212 : /* there may be empty slots corresponding to non-baserel RTEs */
213 700416 : if (rel == NULL)
214 163772 : continue;
215 :
216 : /* Ignore any "otherrels" that were already added. */
217 536644 : if (rel->reloptkind != RELOPT_BASEREL)
218 58256 : continue;
219 :
220 : /* If it's marked as inheritable, look for children. */
221 478388 : if (rte->inh)
222 22036 : expand_inherited_rtentry(root, rel, rte, rti);
223 : }
224 339202 : }
225 :
226 :
227 : /*****************************************************************************
228 : *
229 : * TARGET LISTS
230 : *
231 : *****************************************************************************/
232 :
233 : /*
234 : * build_base_rel_tlists
235 : * Add targetlist entries for each var needed in the query's final tlist
236 : * (and HAVING clause, if any) to the appropriate base relations.
237 : *
238 : * We mark such vars as needed by "relation 0" to ensure that they will
239 : * propagate up through all join plan steps.
240 : */
241 : void
242 339234 : build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
243 : {
244 339234 : List *tlist_vars = pull_var_clause((Node *) final_tlist,
245 : PVC_RECURSE_AGGREGATES |
246 : PVC_RECURSE_WINDOWFUNCS |
247 : PVC_INCLUDE_PLACEHOLDERS);
248 :
249 339234 : if (tlist_vars != NIL)
250 : {
251 315432 : add_vars_to_targetlist(root, tlist_vars, bms_make_singleton(0));
252 315432 : list_free(tlist_vars);
253 : }
254 :
255 : /*
256 : * If there's a HAVING clause, we'll need the Vars it uses, too. Note
257 : * that HAVING can contain Aggrefs but not WindowFuncs.
258 : */
259 339234 : if (root->parse->havingQual)
260 : {
261 932 : List *having_vars = pull_var_clause(root->parse->havingQual,
262 : PVC_RECURSE_AGGREGATES |
263 : PVC_INCLUDE_PLACEHOLDERS);
264 :
265 932 : if (having_vars != NIL)
266 : {
267 812 : add_vars_to_targetlist(root, having_vars,
268 : bms_make_singleton(0));
269 812 : list_free(having_vars);
270 : }
271 : }
272 339234 : }
273 :
274 : /*
275 : * add_vars_to_targetlist
276 : * For each variable appearing in the list, add it to the owning
277 : * relation's targetlist if not already present, and mark the variable
278 : * as being needed for the indicated join (or for final output if
279 : * where_needed includes "relation 0").
280 : *
281 : * The list may also contain PlaceHolderVars. These don't necessarily
282 : * have a single owning relation; we keep their attr_needed info in
283 : * root->placeholder_list instead. Find or create the associated
284 : * PlaceHolderInfo entry, and update its ph_needed.
285 : *
286 : * See also add_vars_to_attr_needed.
287 : */
288 : void
289 649890 : add_vars_to_targetlist(PlannerInfo *root, List *vars,
290 : Relids where_needed)
291 : {
292 : ListCell *temp;
293 :
294 : Assert(!bms_is_empty(where_needed));
295 :
296 2278430 : foreach(temp, vars)
297 : {
298 1628540 : Node *node = (Node *) lfirst(temp);
299 :
300 1628540 : if (IsA(node, Var))
301 : {
302 1625360 : Var *var = (Var *) node;
303 1625360 : RelOptInfo *rel = find_base_rel(root, var->varno);
304 1625360 : int attno = var->varattno;
305 :
306 1625360 : if (bms_is_subset(where_needed, rel->relids))
307 1408 : continue;
308 : Assert(attno >= rel->min_attr && attno <= rel->max_attr);
309 1623952 : attno -= rel->min_attr;
310 1623952 : if (rel->attr_needed[attno] == NULL)
311 : {
312 : /*
313 : * Variable not yet requested, so add to rel's targetlist.
314 : *
315 : * The value available at the rel's scan level has not been
316 : * nulled by any outer join, so drop its varnullingrels.
317 : * (We'll put those back as we climb up the join tree.)
318 : */
319 1222192 : var = copyObject(var);
320 1222192 : var->varnullingrels = NULL;
321 1222192 : rel->reltarget->exprs = lappend(rel->reltarget->exprs, var);
322 : /* reltarget cost and width will be computed later */
323 : }
324 1623952 : rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
325 : where_needed);
326 : }
327 3180 : else if (IsA(node, PlaceHolderVar))
328 : {
329 3180 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
330 3180 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
331 :
332 3180 : phinfo->ph_needed = bms_add_members(phinfo->ph_needed,
333 : where_needed);
334 : }
335 : else
336 0 : elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
337 : }
338 649890 : }
339 :
340 : /*
341 : * add_vars_to_attr_needed
342 : * This does a subset of what add_vars_to_targetlist does: it just
343 : * updates attr_needed for Vars and ph_needed for PlaceHolderVars.
344 : * We assume the Vars are already in their relations' targetlists.
345 : *
346 : * This is used to rebuild attr_needed/ph_needed sets after removal
347 : * of a useless outer join. The removed join clause might have been
348 : * the only upper-level use of some other relation's Var, in which
349 : * case we can reduce that Var's attr_needed and thereby possibly
350 : * open the door to further join removals. But we can't tell that
351 : * without tedious reconstruction of the attr_needed data.
352 : *
353 : * Note that if a Var's attr_needed is successfully reduced to empty,
354 : * it will still be in the relation's targetlist even though we do
355 : * not really need the scan plan node to emit it. The extra plan
356 : * inefficiency seems tiny enough to not be worth spending planner
357 : * cycles to get rid of it.
358 : */
359 : void
360 14102 : add_vars_to_attr_needed(PlannerInfo *root, List *vars,
361 : Relids where_needed)
362 : {
363 : ListCell *temp;
364 :
365 : Assert(!bms_is_empty(where_needed));
366 :
367 32638 : foreach(temp, vars)
368 : {
369 18536 : Node *node = (Node *) lfirst(temp);
370 :
371 18536 : if (IsA(node, Var))
372 : {
373 18440 : Var *var = (Var *) node;
374 18440 : RelOptInfo *rel = find_base_rel(root, var->varno);
375 18440 : int attno = var->varattno;
376 :
377 18440 : if (bms_is_subset(where_needed, rel->relids))
378 856 : continue;
379 : Assert(attno >= rel->min_attr && attno <= rel->max_attr);
380 17584 : attno -= rel->min_attr;
381 17584 : rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
382 : where_needed);
383 : }
384 96 : else if (IsA(node, PlaceHolderVar))
385 : {
386 96 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
387 96 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
388 :
389 96 : phinfo->ph_needed = bms_add_members(phinfo->ph_needed,
390 : where_needed);
391 : }
392 : else
393 0 : elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
394 : }
395 14102 : }
396 :
397 : /*****************************************************************************
398 : *
399 : * GROUP BY
400 : *
401 : *****************************************************************************/
402 :
403 : /*
404 : * remove_useless_groupby_columns
405 : * Remove any columns in the GROUP BY clause that are redundant due to
406 : * being functionally dependent on other GROUP BY columns.
407 : *
408 : * Since some other DBMSes do not allow references to ungrouped columns, it's
409 : * not unusual to find all columns listed in GROUP BY even though listing the
410 : * primary-key columns, or columns of a unique constraint would be sufficient.
411 : * Deleting such excess columns avoids redundant sorting or hashing work, so
412 : * it's worth doing.
413 : *
414 : * Relcache invalidations will ensure that cached plans become invalidated
415 : * when the underlying supporting indexes are dropped or if a column's NOT
416 : * NULL attribute is removed.
417 : */
418 : void
419 339204 : remove_useless_groupby_columns(PlannerInfo *root)
420 : {
421 339204 : Query *parse = root->parse;
422 : Bitmapset **groupbyattnos;
423 : Bitmapset **surplusvars;
424 339204 : bool tryremove = false;
425 : ListCell *lc;
426 : int relid;
427 :
428 : /* No chance to do anything if there are less than two GROUP BY items */
429 339204 : if (list_length(root->processed_groupClause) < 2)
430 337076 : return;
431 :
432 : /* Don't fiddle with the GROUP BY clause if the query has grouping sets */
433 2128 : if (parse->groupingSets)
434 686 : return;
435 :
436 : /*
437 : * Scan the GROUP BY clause to find GROUP BY items that are simple Vars.
438 : * Fill groupbyattnos[k] with a bitmapset of the column attnos of RTE k
439 : * that are GROUP BY items.
440 : */
441 1442 : groupbyattnos = palloc0_array(Bitmapset *, list_length(parse->rtable) + 1);
442 5218 : foreach(lc, root->processed_groupClause)
443 : {
444 3776 : SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
445 3776 : TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
446 3776 : Var *var = (Var *) tle->expr;
447 :
448 : /*
449 : * Ignore non-Vars and Vars from other query levels.
450 : *
451 : * XXX in principle, stable expressions containing Vars could also be
452 : * removed, if all the Vars are functionally dependent on other GROUP
453 : * BY items. But it's not clear that such cases occur often enough to
454 : * be worth troubling over.
455 : */
456 3776 : if (!IsA(var, Var) ||
457 2966 : var->varlevelsup > 0)
458 810 : continue;
459 :
460 : /* OK, remember we have this Var */
461 2966 : relid = var->varno;
462 : Assert(relid <= list_length(parse->rtable));
463 :
464 : /*
465 : * If this isn't the first column for this relation then we now have
466 : * multiple columns. That means there might be some that can be
467 : * removed.
468 : */
469 2966 : tryremove |= !bms_is_empty(groupbyattnos[relid]);
470 2966 : groupbyattnos[relid] = bms_add_member(groupbyattnos[relid],
471 2966 : var->varattno - FirstLowInvalidHeapAttributeNumber);
472 : }
473 :
474 : /*
475 : * No Vars or didn't find multiple Vars for any relation in the GROUP BY?
476 : * If so, nothing can be removed, so don't waste more effort trying.
477 : */
478 1442 : if (!tryremove)
479 452 : return;
480 :
481 : /*
482 : * Consider each relation and see if it is possible to remove some of its
483 : * Vars from GROUP BY. For simplicity and speed, we do the actual removal
484 : * in a separate pass. Here, we just fill surplusvars[k] with a bitmapset
485 : * of the column attnos of RTE k that are removable GROUP BY items.
486 : */
487 990 : surplusvars = NULL; /* don't allocate array unless required */
488 990 : relid = 0;
489 4148 : foreach(lc, parse->rtable)
490 : {
491 3158 : RangeTblEntry *rte = lfirst_node(RangeTblEntry, lc);
492 : RelOptInfo *rel;
493 : Bitmapset *relattnos;
494 3158 : Bitmapset *best_keycolumns = NULL;
495 3158 : int32 best_nkeycolumns = PG_INT32_MAX;
496 :
497 3158 : relid++;
498 :
499 : /* Only plain relations could have primary-key constraints */
500 3158 : if (rte->rtekind != RTE_RELATION)
501 1606 : continue;
502 :
503 : /*
504 : * We must skip inheritance parent tables as some of the child rels
505 : * may cause duplicate rows. This cannot happen with partitioned
506 : * tables, however.
507 : */
508 1552 : if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
509 18 : continue;
510 :
511 : /* Nothing to do unless this rel has multiple Vars in GROUP BY */
512 1534 : relattnos = groupbyattnos[relid];
513 1534 : if (bms_membership(relattnos) != BMS_MULTIPLE)
514 580 : continue;
515 :
516 954 : rel = root->simple_rel_array[relid];
517 :
518 : /*
519 : * Now check each index for this relation to see if there are any with
520 : * columns which are a proper subset of the grouping columns for this
521 : * relation.
522 : */
523 2954 : foreach_node(IndexOptInfo, index, rel->indexlist)
524 : {
525 : Bitmapset *ind_attnos;
526 : bool nulls_check_ok;
527 :
528 : /*
529 : * Skip any non-unique and deferrable indexes. Predicate indexes
530 : * have not been checked yet, so we must skip those too as the
531 : * predOK check that's done later might fail.
532 : */
533 1046 : if (!index->unique || !index->immediate || index->indpred != NIL)
534 410 : continue;
535 :
536 : /* For simplicity, we currently don't support expression indexes */
537 636 : if (index->indexprs != NIL)
538 0 : continue;
539 :
540 636 : ind_attnos = NULL;
541 636 : nulls_check_ok = true;
542 1604 : for (int i = 0; i < index->nkeycolumns; i++)
543 : {
544 : /*
545 : * We must insist that the index columns are all defined NOT
546 : * NULL otherwise duplicate NULLs could exist. However, we
547 : * can relax this check when the index is defined with NULLS
548 : * NOT DISTINCT as there can only be 1 NULL row, therefore
549 : * functional dependency on the unique columns is maintained,
550 : * despite the NULL.
551 : */
552 974 : if (!index->nullsnotdistinct &&
553 968 : !bms_is_member(index->indexkeys[i],
554 968 : rel->notnullattnums))
555 : {
556 6 : nulls_check_ok = false;
557 6 : break;
558 : }
559 :
560 : ind_attnos =
561 968 : bms_add_member(ind_attnos,
562 968 : index->indexkeys[i] -
563 : FirstLowInvalidHeapAttributeNumber);
564 : }
565 :
566 636 : if (!nulls_check_ok)
567 6 : continue;
568 :
569 : /*
570 : * Skip any indexes where the indexed columns aren't a proper
571 : * subset of the GROUP BY.
572 : */
573 630 : if (bms_subset_compare(ind_attnos, relattnos) != BMS_SUBSET1)
574 290 : continue;
575 :
576 : /*
577 : * Record the attribute numbers from the index with the fewest
578 : * columns. This allows the largest number of columns to be
579 : * removed from the GROUP BY clause. In the future, we may wish
580 : * to consider using the narrowest set of columns and looking at
581 : * pg_statistic.stawidth as it might be better to use an index
582 : * with, say two INT4s, rather than, say, one long varlena column.
583 : */
584 340 : if (index->nkeycolumns < best_nkeycolumns)
585 : {
586 322 : best_keycolumns = ind_attnos;
587 322 : best_nkeycolumns = index->nkeycolumns;
588 : }
589 : }
590 :
591 : /* Did we find a suitable index? */
592 954 : if (!bms_is_empty(best_keycolumns))
593 : {
594 : /*
595 : * To easily remember whether we've found anything to do, we don't
596 : * allocate the surplusvars[] array until we find something.
597 : */
598 322 : if (surplusvars == NULL)
599 316 : surplusvars = palloc0_array(Bitmapset *, list_length(parse->rtable) + 1);
600 :
601 : /* Remember the attnos of the removable columns */
602 322 : surplusvars[relid] = bms_difference(relattnos, best_keycolumns);
603 : }
604 : }
605 :
606 : /*
607 : * If we found any surplus Vars, build a new GROUP BY clause without them.
608 : * (Note: this may leave some TLEs with unreferenced ressortgroupref
609 : * markings, but that's harmless.)
610 : */
611 990 : if (surplusvars != NULL)
612 : {
613 316 : List *new_groupby = NIL;
614 :
615 1298 : foreach(lc, root->processed_groupClause)
616 : {
617 982 : SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
618 982 : TargetEntry *tle = get_sortgroupclause_tle(sgc, parse->targetList);
619 982 : Var *var = (Var *) tle->expr;
620 :
621 : /*
622 : * New list must include non-Vars, outer Vars, and anything not
623 : * marked as surplus.
624 : */
625 982 : if (!IsA(var, Var) ||
626 982 : var->varlevelsup > 0 ||
627 982 : !bms_is_member(var->varattno - FirstLowInvalidHeapAttributeNumber,
628 982 : surplusvars[var->varno]))
629 618 : new_groupby = lappend(new_groupby, sgc);
630 : }
631 :
632 316 : root->processed_groupClause = new_groupby;
633 : }
634 : }
635 :
636 : /*
637 : * setup_eager_aggregation
638 : * Check if eager aggregation is applicable, and if so collect suitable
639 : * aggregate expressions and grouping expressions in the query.
640 : */
641 : void
642 339204 : setup_eager_aggregation(PlannerInfo *root)
643 : {
644 : /*
645 : * Don't apply eager aggregation if disabled by user.
646 : */
647 339204 : if (!enable_eager_aggregate)
648 480 : return;
649 :
650 : /*
651 : * Don't apply eager aggregation if there are no available GROUP BY
652 : * clauses.
653 : */
654 338724 : if (!root->processed_groupClause)
655 334470 : return;
656 :
657 : /*
658 : * For now we don't try to support grouping sets.
659 : */
660 4254 : if (root->parse->groupingSets)
661 778 : return;
662 :
663 : /*
664 : * For now we don't try to support DISTINCT or ORDER BY aggregates.
665 : */
666 3476 : if (root->numOrderedAggs > 0)
667 192 : return;
668 :
669 : /*
670 : * If there are any aggregates that do not support partial mode, or any
671 : * partial aggregates that are non-serializable, do not apply eager
672 : * aggregation.
673 : */
674 3284 : if (root->hasNonPartialAggs || root->hasNonSerialAggs)
675 154 : return;
676 :
677 : /*
678 : * We don't try to apply eager aggregation if there are set-returning
679 : * functions in targetlist.
680 : */
681 3130 : if (root->parse->hasTargetSRFs)
682 72 : return;
683 :
684 : /*
685 : * Eager aggregation only makes sense if there are multiple base rels in
686 : * the query.
687 : */
688 3058 : if (bms_membership(root->all_baserels) != BMS_MULTIPLE)
689 2072 : return;
690 :
691 : /*
692 : * Don't apply eager aggregation if any aggregate poses a risk of
693 : * excessive memory usage during partial aggregation.
694 : */
695 986 : if (is_partial_agg_memory_risky(root))
696 2 : return;
697 :
698 : /*
699 : * Collect aggregate expressions and plain Vars that appear in the
700 : * targetlist and havingQual.
701 : */
702 984 : create_agg_clause_infos(root);
703 :
704 : /*
705 : * If there are no suitable aggregate expressions, we cannot apply eager
706 : * aggregation.
707 : */
708 984 : if (root->agg_clause_list == NIL)
709 326 : return;
710 :
711 : /*
712 : * Collect grouping expressions that appear in grouping clauses.
713 : */
714 658 : create_grouping_expr_infos(root);
715 : }
716 :
717 : /*
718 : * is_partial_agg_memory_risky
719 : * Check if any aggregate poses a risk of excessive memory usage during
720 : * partial aggregation.
721 : *
722 : * We check if any aggregate has a negative aggtransspace value, which
723 : * indicates that its transition state data can grow unboundedly in size.
724 : * Applying eager aggregation in such cases risks high memory usage since
725 : * partial aggregation results might be stored in join hash tables or
726 : * materialized nodes.
727 : */
728 : static bool
729 986 : is_partial_agg_memory_risky(PlannerInfo *root)
730 : {
731 : ListCell *lc;
732 :
733 1902 : foreach(lc, root->aggtransinfos)
734 : {
735 918 : AggTransInfo *transinfo = lfirst_node(AggTransInfo, lc);
736 :
737 918 : if (transinfo->aggtransspace < 0)
738 2 : return true;
739 : }
740 :
741 984 : return false;
742 : }
743 :
744 : /*
745 : * create_agg_clause_infos
746 : * Search the targetlist and havingQual for Aggrefs and plain Vars, and
747 : * create an AggClauseInfo for each Aggref node.
748 : */
749 : static void
750 984 : create_agg_clause_infos(PlannerInfo *root)
751 : {
752 : List *tlist_exprs;
753 984 : List *agg_clause_list = NIL;
754 984 : List *tlist_vars = NIL;
755 984 : Relids aggregate_relids = NULL;
756 984 : bool eager_agg_applicable = true;
757 : ListCell *lc;
758 :
759 : Assert(root->agg_clause_list == NIL);
760 : Assert(root->tlist_vars == NIL);
761 :
762 984 : tlist_exprs = pull_var_clause((Node *) root->processed_tlist,
763 : PVC_INCLUDE_AGGREGATES |
764 : PVC_RECURSE_WINDOWFUNCS |
765 : PVC_RECURSE_PLACEHOLDERS);
766 :
767 : /*
768 : * Aggregates within the HAVING clause need to be processed in the same
769 : * way as those in the targetlist. Note that HAVING can contain Aggrefs
770 : * but not WindowFuncs.
771 : */
772 984 : if (root->parse->havingQual != NULL)
773 : {
774 : List *having_exprs;
775 :
776 58 : having_exprs = pull_var_clause((Node *) root->parse->havingQual,
777 : PVC_INCLUDE_AGGREGATES |
778 : PVC_RECURSE_PLACEHOLDERS);
779 58 : if (having_exprs != NIL)
780 : {
781 58 : tlist_exprs = list_concat(tlist_exprs, having_exprs);
782 58 : list_free(having_exprs);
783 : }
784 : }
785 :
786 4368 : foreach(lc, tlist_exprs)
787 : {
788 3432 : Expr *expr = (Expr *) lfirst(lc);
789 : Aggref *aggref;
790 : Relids agg_eval_at;
791 : AggClauseInfo *ac_info;
792 :
793 : /* For now we don't try to support GROUPING() expressions */
794 3432 : if (IsA(expr, GroupingFunc))
795 : {
796 0 : eager_agg_applicable = false;
797 0 : break;
798 : }
799 :
800 : /* Collect plain Vars for future reference */
801 3432 : if (IsA(expr, Var))
802 : {
803 2510 : tlist_vars = list_append_unique(tlist_vars, expr);
804 2510 : continue;
805 : }
806 :
807 922 : aggref = castNode(Aggref, expr);
808 :
809 : Assert(aggref->aggorder == NIL);
810 : Assert(aggref->aggdistinct == NIL);
811 :
812 : /*
813 : * If there are any securityQuals, do not try to apply eager
814 : * aggregation if any non-leakproof aggregate functions are present.
815 : * This is overly strict, but for now...
816 : */
817 922 : if (root->qual_security_level > 0 &&
818 0 : !get_func_leakproof(aggref->aggfnoid))
819 : {
820 0 : eager_agg_applicable = false;
821 0 : break;
822 : }
823 :
824 922 : agg_eval_at = pull_varnos(root, (Node *) aggref);
825 :
826 : /*
827 : * If all base relations in the query are referenced by aggregate
828 : * functions, then eager aggregation is not applicable.
829 : */
830 922 : aggregate_relids = bms_add_members(aggregate_relids, agg_eval_at);
831 922 : if (bms_is_subset(root->all_baserels, aggregate_relids))
832 : {
833 48 : eager_agg_applicable = false;
834 48 : break;
835 : }
836 :
837 : /* OK, create the AggClauseInfo node */
838 874 : ac_info = makeNode(AggClauseInfo);
839 874 : ac_info->aggref = aggref;
840 874 : ac_info->agg_eval_at = agg_eval_at;
841 :
842 : /* ... and add it to the list */
843 874 : agg_clause_list = list_append_unique(agg_clause_list, ac_info);
844 : }
845 :
846 984 : list_free(tlist_exprs);
847 :
848 984 : if (eager_agg_applicable)
849 : {
850 936 : root->agg_clause_list = agg_clause_list;
851 936 : root->tlist_vars = tlist_vars;
852 : }
853 : else
854 : {
855 48 : list_free_deep(agg_clause_list);
856 48 : list_free(tlist_vars);
857 : }
858 984 : }
859 :
860 : /*
861 : * create_grouping_expr_infos
862 : * Create a GroupingExprInfo for each expression usable as grouping key.
863 : *
864 : * If any grouping expression is not suitable, we will just return with
865 : * root->group_expr_list being NIL.
866 : */
867 : static void
868 658 : create_grouping_expr_infos(PlannerInfo *root)
869 : {
870 658 : List *exprs = NIL;
871 658 : List *sortgrouprefs = NIL;
872 658 : List *ecs = NIL;
873 : ListCell *lc,
874 : *lc1,
875 : *lc2,
876 : *lc3;
877 :
878 : Assert(root->group_expr_list == NIL);
879 :
880 1306 : foreach(lc, root->processed_groupClause)
881 : {
882 714 : SortGroupClause *sgc = lfirst_node(SortGroupClause, lc);
883 714 : TargetEntry *tle = get_sortgroupclause_tle(sgc, root->processed_tlist);
884 : TypeCacheEntry *tce;
885 : Oid equalimageproc;
886 :
887 : Assert(tle->ressortgroupref > 0);
888 :
889 : /*
890 : * For now we only support plain Vars as grouping expressions.
891 : */
892 714 : if (!IsA(tle->expr, Var))
893 66 : return;
894 :
895 : /*
896 : * Eager aggregation is only possible if equality implies image
897 : * equality for each grouping key. Otherwise, placing keys with
898 : * different byte images into the same group may result in the loss of
899 : * information that could be necessary to evaluate upper qual clauses.
900 : *
901 : * For instance, the NUMERIC data type is not supported, as values
902 : * that are considered equal by the equality operator (e.g., 0 and
903 : * 0.0) can have different scales.
904 : */
905 654 : tce = lookup_type_cache(exprType((Node *) tle->expr),
906 : TYPECACHE_BTREE_OPFAMILY);
907 654 : if (!OidIsValid(tce->btree_opf) ||
908 654 : !OidIsValid(tce->btree_opintype))
909 0 : return;
910 :
911 654 : equalimageproc = get_opfamily_proc(tce->btree_opf,
912 : tce->btree_opintype,
913 : tce->btree_opintype,
914 : BTEQUALIMAGE_PROC);
915 654 : if (!OidIsValid(equalimageproc) ||
916 648 : !DatumGetBool(OidFunctionCall1Coll(equalimageproc,
917 : tce->typcollation,
918 : ObjectIdGetDatum(tce->btree_opintype))))
919 6 : return;
920 :
921 648 : exprs = lappend(exprs, tle->expr);
922 648 : sortgrouprefs = lappend_int(sortgrouprefs, tle->ressortgroupref);
923 648 : ecs = lappend(ecs, get_eclass_for_sortgroupclause(root, sgc, tle->expr));
924 : }
925 :
926 : /*
927 : * Construct a GroupingExprInfo for each expression.
928 : */
929 1228 : forthree(lc1, exprs, lc2, sortgrouprefs, lc3, ecs)
930 : {
931 636 : Expr *expr = (Expr *) lfirst(lc1);
932 636 : int sortgroupref = lfirst_int(lc2);
933 636 : EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc3);
934 : GroupingExprInfo *ge_info;
935 :
936 636 : ge_info = makeNode(GroupingExprInfo);
937 636 : ge_info->expr = (Expr *) copyObject(expr);
938 636 : ge_info->sortgroupref = sortgroupref;
939 636 : ge_info->ec = ec;
940 :
941 636 : root->group_expr_list = lappend(root->group_expr_list, ge_info);
942 : }
943 : }
944 :
945 : /*
946 : * get_eclass_for_sortgroupclause
947 : * Given a group clause and an expression, find an existing equivalence
948 : * class that the expression is a member of; return NULL if none.
949 : */
950 : static EquivalenceClass *
951 648 : get_eclass_for_sortgroupclause(PlannerInfo *root, SortGroupClause *sgc,
952 : Expr *expr)
953 : {
954 : Oid opfamily,
955 : opcintype,
956 : collation;
957 : CompareType cmptype;
958 : Oid equality_op;
959 : List *opfamilies;
960 :
961 : /* Punt if the group clause is not sortable */
962 648 : if (!OidIsValid(sgc->sortop))
963 0 : return NULL;
964 :
965 : /* Find the operator in pg_amop --- failure shouldn't happen */
966 648 : if (!get_ordering_op_properties(sgc->sortop,
967 : &opfamily, &opcintype, &cmptype))
968 0 : elog(ERROR, "operator %u is not a valid ordering operator",
969 : sgc->sortop);
970 :
971 : /* Because SortGroupClause doesn't carry collation, consult the expr */
972 648 : collation = exprCollation((Node *) expr);
973 :
974 : /*
975 : * EquivalenceClasses need to contain opfamily lists based on the family
976 : * membership of mergejoinable equality operators, which could belong to
977 : * more than one opfamily. So we have to look up the opfamily's equality
978 : * operator and get its membership.
979 : */
980 648 : equality_op = get_opfamily_member_for_cmptype(opfamily,
981 : opcintype,
982 : opcintype,
983 : COMPARE_EQ);
984 648 : if (!OidIsValid(equality_op)) /* shouldn't happen */
985 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
986 : COMPARE_EQ, opcintype, opcintype, opfamily);
987 648 : opfamilies = get_mergejoin_opfamilies(equality_op);
988 648 : if (!opfamilies) /* certainly should find some */
989 0 : elog(ERROR, "could not find opfamilies for equality operator %u",
990 : equality_op);
991 :
992 : /* Now find a matching EquivalenceClass */
993 648 : return get_eclass_for_sort_expr(root, expr, opfamilies, opcintype,
994 : collation, sgc->tleSortGroupRef,
995 : NULL, false);
996 : }
997 :
998 : /*****************************************************************************
999 : *
1000 : * LATERAL REFERENCES
1001 : *
1002 : *****************************************************************************/
1003 :
1004 : /*
1005 : * find_lateral_references
1006 : * For each LATERAL subquery, extract all its references to Vars and
1007 : * PlaceHolderVars of the current query level, and make sure those values
1008 : * will be available for evaluation of the subquery.
1009 : *
1010 : * While later planning steps ensure that the Var/PHV source rels are on the
1011 : * outside of nestloops relative to the LATERAL subquery, we also need to
1012 : * ensure that the Vars/PHVs propagate up to the nestloop join level; this
1013 : * means setting suitable where_needed values for them.
1014 : *
1015 : * Note that this only deals with lateral references in unflattened LATERAL
1016 : * subqueries. When we flatten a LATERAL subquery, its lateral references
1017 : * become plain Vars in the parent query, but they may have to be wrapped in
1018 : * PlaceHolderVars if they need to be forced NULL by outer joins that don't
1019 : * also null the LATERAL subquery. That's all handled elsewhere.
1020 : *
1021 : * This has to run before deconstruct_jointree, since it might result in
1022 : * creation of PlaceHolderInfos.
1023 : */
1024 : void
1025 339204 : find_lateral_references(PlannerInfo *root)
1026 : {
1027 : Index rti;
1028 :
1029 : /* We need do nothing if the query contains no LATERAL RTEs */
1030 339204 : if (!root->hasLateralRTEs)
1031 328770 : return;
1032 :
1033 : /*
1034 : * Examine all baserels (the rel array has been set up by now).
1035 : */
1036 41260 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1037 : {
1038 30826 : RelOptInfo *brel = root->simple_rel_array[rti];
1039 :
1040 : /* there may be empty slots corresponding to non-baserel RTEs */
1041 30826 : if (brel == NULL)
1042 7052 : continue;
1043 :
1044 : Assert(brel->relid == rti); /* sanity check on array */
1045 :
1046 : /*
1047 : * This bit is less obvious than it might look. We ignore appendrel
1048 : * otherrels and consider only their parent baserels. In a case where
1049 : * a LATERAL-containing UNION ALL subquery was pulled up, it is the
1050 : * otherrel that is actually going to be in the plan. However, we
1051 : * want to mark all its lateral references as needed by the parent,
1052 : * because it is the parent's relid that will be used for join
1053 : * planning purposes. And the parent's RTE will contain all the
1054 : * lateral references we need to know, since the pulled-up member is
1055 : * nothing but a copy of parts of the original RTE's subquery. We
1056 : * could visit the parent's children instead and transform their
1057 : * references back to the parent's relid, but it would be much more
1058 : * complicated for no real gain. (Important here is that the child
1059 : * members have not yet received any processing beyond being pulled
1060 : * up.) Similarly, in appendrels created by inheritance expansion,
1061 : * it's sufficient to look at the parent relation.
1062 : */
1063 :
1064 : /* ignore RTEs that are "other rels" */
1065 23774 : if (brel->reloptkind != RELOPT_BASEREL)
1066 0 : continue;
1067 :
1068 23774 : extract_lateral_references(root, brel, rti);
1069 : }
1070 : }
1071 :
1072 : static void
1073 23774 : extract_lateral_references(PlannerInfo *root, RelOptInfo *brel, Index rtindex)
1074 : {
1075 23774 : RangeTblEntry *rte = root->simple_rte_array[rtindex];
1076 : List *vars;
1077 : List *newvars;
1078 : Relids where_needed;
1079 : ListCell *lc;
1080 :
1081 : /* No cross-references are possible if it's not LATERAL */
1082 23774 : if (!rte->lateral)
1083 13984 : return;
1084 :
1085 : /* Fetch the appropriate variables */
1086 9790 : if (rte->rtekind == RTE_RELATION)
1087 36 : vars = pull_vars_of_level((Node *) rte->tablesample, 0);
1088 9754 : else if (rte->rtekind == RTE_SUBQUERY)
1089 800 : vars = pull_vars_of_level((Node *) rte->subquery, 1);
1090 8954 : else if (rte->rtekind == RTE_FUNCTION)
1091 8648 : vars = pull_vars_of_level((Node *) rte->functions, 0);
1092 306 : else if (rte->rtekind == RTE_TABLEFUNC)
1093 234 : vars = pull_vars_of_level((Node *) rte->tablefunc, 0);
1094 72 : else if (rte->rtekind == RTE_VALUES)
1095 72 : vars = pull_vars_of_level((Node *) rte->values_lists, 0);
1096 : else
1097 : {
1098 : Assert(false);
1099 0 : return; /* keep compiler quiet */
1100 : }
1101 :
1102 9790 : if (vars == NIL)
1103 100 : return; /* nothing to do */
1104 :
1105 : /* Copy each Var (or PlaceHolderVar) and adjust it to match our level */
1106 9690 : newvars = NIL;
1107 20294 : foreach(lc, vars)
1108 : {
1109 10604 : Node *node = (Node *) lfirst(lc);
1110 :
1111 10604 : node = copyObject(node);
1112 10604 : if (IsA(node, Var))
1113 : {
1114 10478 : Var *var = (Var *) node;
1115 :
1116 : /* Adjustment is easy since it's just one node */
1117 10478 : var->varlevelsup = 0;
1118 : }
1119 126 : else if (IsA(node, PlaceHolderVar))
1120 : {
1121 126 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
1122 126 : int levelsup = phv->phlevelsup;
1123 :
1124 : /* Have to work harder to adjust the contained expression too */
1125 126 : if (levelsup != 0)
1126 90 : IncrementVarSublevelsUp(node, -levelsup, 0);
1127 :
1128 : /*
1129 : * If we pulled the PHV out of a subquery RTE, its expression
1130 : * needs to be preprocessed. subquery_planner() already did this
1131 : * for level-zero PHVs in function and values RTEs, though.
1132 : */
1133 126 : if (levelsup > 0)
1134 90 : phv->phexpr = preprocess_phv_expression(root, phv->phexpr);
1135 : }
1136 : else
1137 : Assert(false);
1138 10604 : newvars = lappend(newvars, node);
1139 : }
1140 :
1141 9690 : list_free(vars);
1142 :
1143 : /*
1144 : * We mark the Vars as being "needed" at the LATERAL RTE. This is a bit
1145 : * of a cheat: a more formal approach would be to mark each one as needed
1146 : * at the join of the LATERAL RTE with its source RTE. But it will work,
1147 : * and it's much less tedious than computing a separate where_needed for
1148 : * each Var.
1149 : */
1150 9690 : where_needed = bms_make_singleton(rtindex);
1151 :
1152 : /*
1153 : * Push Vars into their source relations' targetlists, and PHVs into
1154 : * root->placeholder_list.
1155 : */
1156 9690 : add_vars_to_targetlist(root, newvars, where_needed);
1157 :
1158 : /*
1159 : * Remember the lateral references for rebuild_lateral_attr_needed and
1160 : * create_lateral_join_info.
1161 : */
1162 9690 : brel->lateral_vars = newvars;
1163 : }
1164 :
1165 : /*
1166 : * rebuild_lateral_attr_needed
1167 : * Put back attr_needed bits for Vars/PHVs needed for lateral references.
1168 : *
1169 : * This is used to rebuild attr_needed/ph_needed sets after removal of a
1170 : * useless outer join. It should match what find_lateral_references did,
1171 : * except that we call add_vars_to_attr_needed not add_vars_to_targetlist.
1172 : */
1173 : void
1174 12046 : rebuild_lateral_attr_needed(PlannerInfo *root)
1175 : {
1176 : Index rti;
1177 :
1178 : /* We need do nothing if the query contains no LATERAL RTEs */
1179 12046 : if (!root->hasLateralRTEs)
1180 11386 : return;
1181 :
1182 : /* Examine the same baserels that find_lateral_references did */
1183 6814 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1184 : {
1185 6154 : RelOptInfo *brel = root->simple_rel_array[rti];
1186 : Relids where_needed;
1187 :
1188 6154 : if (brel == NULL)
1189 4386 : continue;
1190 1768 : if (brel->reloptkind != RELOPT_BASEREL)
1191 0 : continue;
1192 :
1193 : /*
1194 : * We don't need to repeat all of extract_lateral_references, since it
1195 : * kindly saved the extracted Vars/PHVs in lateral_vars.
1196 : */
1197 1768 : if (brel->lateral_vars == NIL)
1198 1428 : continue;
1199 :
1200 340 : where_needed = bms_make_singleton(rti);
1201 :
1202 340 : add_vars_to_attr_needed(root, brel->lateral_vars, where_needed);
1203 : }
1204 : }
1205 :
1206 : /*
1207 : * create_lateral_join_info
1208 : * Fill in the per-base-relation direct_lateral_relids, lateral_relids
1209 : * and lateral_referencers sets.
1210 : */
1211 : void
1212 339204 : create_lateral_join_info(PlannerInfo *root)
1213 : {
1214 339204 : bool found_laterals = false;
1215 : Index rti;
1216 : ListCell *lc;
1217 :
1218 : /* We need do nothing if the query contains no LATERAL RTEs */
1219 339204 : if (!root->hasLateralRTEs)
1220 328770 : return;
1221 :
1222 : /* We'll need to have the ph_eval_at values for PlaceHolderVars */
1223 : Assert(root->placeholdersFrozen);
1224 :
1225 : /*
1226 : * Examine all baserels (the rel array has been set up by now).
1227 : */
1228 41260 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1229 : {
1230 30826 : RelOptInfo *brel = root->simple_rel_array[rti];
1231 : Relids lateral_relids;
1232 :
1233 : /* there may be empty slots corresponding to non-baserel RTEs */
1234 30826 : if (brel == NULL)
1235 7712 : continue;
1236 :
1237 : Assert(brel->relid == rti); /* sanity check on array */
1238 :
1239 : /* ignore RTEs that are "other rels" */
1240 23114 : if (brel->reloptkind != RELOPT_BASEREL)
1241 0 : continue;
1242 :
1243 23114 : lateral_relids = NULL;
1244 :
1245 : /* consider each laterally-referenced Var or PHV */
1246 33550 : foreach(lc, brel->lateral_vars)
1247 : {
1248 10436 : Node *node = (Node *) lfirst(lc);
1249 :
1250 10436 : if (IsA(node, Var))
1251 : {
1252 10310 : Var *var = (Var *) node;
1253 :
1254 10310 : found_laterals = true;
1255 10310 : lateral_relids = bms_add_member(lateral_relids,
1256 : var->varno);
1257 : }
1258 126 : else if (IsA(node, PlaceHolderVar))
1259 : {
1260 126 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
1261 126 : PlaceHolderInfo *phinfo = find_placeholder_info(root, phv);
1262 :
1263 126 : found_laterals = true;
1264 126 : lateral_relids = bms_add_members(lateral_relids,
1265 126 : phinfo->ph_eval_at);
1266 : }
1267 : else
1268 : Assert(false);
1269 : }
1270 :
1271 : /* We now have all the simple lateral refs from this rel */
1272 23114 : brel->direct_lateral_relids = lateral_relids;
1273 23114 : brel->lateral_relids = bms_copy(lateral_relids);
1274 : }
1275 :
1276 : /*
1277 : * Now check for lateral references within PlaceHolderVars, and mark their
1278 : * eval_at rels as having lateral references to the source rels.
1279 : *
1280 : * For a PHV that is due to be evaluated at a baserel, mark its source(s)
1281 : * as direct lateral dependencies of the baserel (adding onto the ones
1282 : * recorded above). If it's due to be evaluated at a join, mark its
1283 : * source(s) as indirect lateral dependencies of each baserel in the join,
1284 : * ie put them into lateral_relids but not direct_lateral_relids. This is
1285 : * appropriate because we can't put any such baserel on the outside of a
1286 : * join to one of the PHV's lateral dependencies, but on the other hand we
1287 : * also can't yet join it directly to the dependency.
1288 : */
1289 11024 : foreach(lc, root->placeholder_list)
1290 : {
1291 590 : PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
1292 590 : Relids eval_at = phinfo->ph_eval_at;
1293 : Relids lateral_refs;
1294 : int varno;
1295 :
1296 590 : if (phinfo->ph_lateral == NULL)
1297 328 : continue; /* PHV is uninteresting if no lateral refs */
1298 :
1299 262 : found_laterals = true;
1300 :
1301 : /*
1302 : * Include only baserels not outer joins in the evaluation sites'
1303 : * lateral relids. This avoids problems when outer join order gets
1304 : * rearranged, and it should still ensure that the lateral values are
1305 : * available when needed.
1306 : */
1307 262 : lateral_refs = bms_intersect(phinfo->ph_lateral, root->all_baserels);
1308 : Assert(!bms_is_empty(lateral_refs));
1309 :
1310 262 : if (bms_get_singleton_member(eval_at, &varno))
1311 : {
1312 : /* Evaluation site is a baserel */
1313 196 : RelOptInfo *brel = find_base_rel(root, varno);
1314 :
1315 196 : brel->direct_lateral_relids =
1316 196 : bms_add_members(brel->direct_lateral_relids,
1317 : lateral_refs);
1318 196 : brel->lateral_relids =
1319 196 : bms_add_members(brel->lateral_relids,
1320 : lateral_refs);
1321 : }
1322 : else
1323 : {
1324 : /* Evaluation site is a join */
1325 66 : varno = -1;
1326 198 : while ((varno = bms_next_member(eval_at, varno)) >= 0)
1327 : {
1328 132 : RelOptInfo *brel = find_base_rel_ignore_join(root, varno);
1329 :
1330 132 : if (brel == NULL)
1331 0 : continue; /* ignore outer joins in eval_at */
1332 132 : brel->lateral_relids = bms_add_members(brel->lateral_relids,
1333 : lateral_refs);
1334 : }
1335 : }
1336 : }
1337 :
1338 : /*
1339 : * If we found no actual lateral references, we're done; but reset the
1340 : * hasLateralRTEs flag to avoid useless work later.
1341 : */
1342 10434 : if (!found_laterals)
1343 : {
1344 740 : root->hasLateralRTEs = false;
1345 740 : return;
1346 : }
1347 :
1348 : /*
1349 : * Calculate the transitive closure of the lateral_relids sets, so that
1350 : * they describe both direct and indirect lateral references. If relation
1351 : * X references Y laterally, and Y references Z laterally, then we will
1352 : * have to scan X on the inside of a nestloop with Z, so for all intents
1353 : * and purposes X is laterally dependent on Z too.
1354 : *
1355 : * This code is essentially Warshall's algorithm for transitive closure.
1356 : * The outer loop considers each baserel, and propagates its lateral
1357 : * dependencies to those baserels that have a lateral dependency on it.
1358 : */
1359 35648 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1360 : {
1361 25954 : RelOptInfo *brel = root->simple_rel_array[rti];
1362 : Relids outer_lateral_relids;
1363 : Index rti2;
1364 :
1365 25954 : if (brel == NULL || brel->reloptkind != RELOPT_BASEREL)
1366 4364 : continue;
1367 :
1368 : /* need not consider baserel further if it has no lateral refs */
1369 21590 : outer_lateral_relids = brel->lateral_relids;
1370 21590 : if (outer_lateral_relids == NULL)
1371 11740 : continue;
1372 :
1373 : /* else scan all baserels */
1374 36788 : for (rti2 = 1; rti2 < root->simple_rel_array_size; rti2++)
1375 : {
1376 26938 : RelOptInfo *brel2 = root->simple_rel_array[rti2];
1377 :
1378 26938 : if (brel2 == NULL || brel2->reloptkind != RELOPT_BASEREL)
1379 4778 : continue;
1380 :
1381 : /* if brel2 has lateral ref to brel, propagate brel's refs */
1382 22160 : if (bms_is_member(rti, brel2->lateral_relids))
1383 72 : brel2->lateral_relids = bms_add_members(brel2->lateral_relids,
1384 : outer_lateral_relids);
1385 : }
1386 : }
1387 :
1388 : /*
1389 : * Now that we've identified all lateral references, mark each baserel
1390 : * with the set of relids of rels that reference it laterally (possibly
1391 : * indirectly) --- that is, the inverse mapping of lateral_relids.
1392 : */
1393 35648 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
1394 : {
1395 25954 : RelOptInfo *brel = root->simple_rel_array[rti];
1396 : Relids lateral_relids;
1397 : int rti2;
1398 :
1399 25954 : if (brel == NULL || brel->reloptkind != RELOPT_BASEREL)
1400 4364 : continue;
1401 :
1402 : /* Nothing to do at rels with no lateral refs */
1403 21590 : lateral_relids = brel->lateral_relids;
1404 21590 : if (bms_is_empty(lateral_relids))
1405 11740 : continue;
1406 :
1407 : /* No rel should have a lateral dependency on itself */
1408 : Assert(!bms_is_member(rti, lateral_relids));
1409 :
1410 : /* Mark this rel's referencees */
1411 9850 : rti2 = -1;
1412 19970 : while ((rti2 = bms_next_member(lateral_relids, rti2)) >= 0)
1413 : {
1414 10120 : RelOptInfo *brel2 = root->simple_rel_array[rti2];
1415 :
1416 10120 : if (brel2 == NULL)
1417 12 : continue; /* must be an OJ */
1418 :
1419 : Assert(brel2->reloptkind == RELOPT_BASEREL);
1420 10108 : brel2->lateral_referencers =
1421 10108 : bms_add_member(brel2->lateral_referencers, rti);
1422 : }
1423 : }
1424 : }
1425 :
1426 :
1427 : /*****************************************************************************
1428 : *
1429 : * JOIN TREE PROCESSING
1430 : *
1431 : *****************************************************************************/
1432 :
1433 : /*
1434 : * deconstruct_jointree
1435 : * Recursively scan the query's join tree for WHERE and JOIN/ON qual
1436 : * clauses, and add these to the appropriate restrictinfo and joininfo
1437 : * lists belonging to base RelOptInfos. Also, add SpecialJoinInfo nodes
1438 : * to root->join_info_list for any outer joins appearing in the query tree.
1439 : * Return a "joinlist" data structure showing the join order decisions
1440 : * that need to be made by make_one_rel().
1441 : *
1442 : * The "joinlist" result is a list of items that are either RangeTblRef
1443 : * jointree nodes or sub-joinlists. All the items at the same level of
1444 : * joinlist must be joined in an order to be determined by make_one_rel()
1445 : * (note that legal orders may be constrained by SpecialJoinInfo nodes).
1446 : * A sub-joinlist represents a subproblem to be planned separately. Currently
1447 : * sub-joinlists arise only from FULL OUTER JOIN or when collapsing of
1448 : * subproblems is stopped by join_collapse_limit or from_collapse_limit.
1449 : */
1450 : List *
1451 339204 : deconstruct_jointree(PlannerInfo *root)
1452 : {
1453 : List *result;
1454 : JoinDomain *top_jdomain;
1455 339204 : List *item_list = NIL;
1456 : ListCell *lc;
1457 :
1458 : /*
1459 : * After this point, no more PlaceHolderInfos may be made, because
1460 : * make_outerjoininfo requires all active placeholders to be present in
1461 : * root->placeholder_list while we crawl up the join tree.
1462 : */
1463 339204 : root->placeholdersFrozen = true;
1464 :
1465 : /* Fetch the already-created top-level join domain for the query */
1466 339204 : top_jdomain = linitial_node(JoinDomain, root->join_domains);
1467 339204 : top_jdomain->jd_relids = NULL; /* filled during deconstruct_recurse */
1468 :
1469 : /* Start recursion at top of jointree */
1470 : Assert(root->parse->jointree != NULL &&
1471 : IsA(root->parse->jointree, FromExpr));
1472 :
1473 : /* These are filled as we scan the jointree */
1474 339204 : root->all_baserels = NULL;
1475 339204 : root->outer_join_rels = NULL;
1476 :
1477 : /* Perform the initial scan of the jointree */
1478 339204 : result = deconstruct_recurse(root, (Node *) root->parse->jointree,
1479 : top_jdomain, NULL,
1480 : &item_list);
1481 :
1482 : /* Now we can form the value of all_query_rels, too */
1483 339204 : root->all_query_rels = bms_union(root->all_baserels, root->outer_join_rels);
1484 :
1485 : /* ... which should match what we computed for the top join domain */
1486 : Assert(bms_equal(root->all_query_rels, top_jdomain->jd_relids));
1487 :
1488 : /* Now scan all the jointree nodes again, and distribute quals */
1489 1282296 : foreach(lc, item_list)
1490 : {
1491 943092 : JoinTreeItem *jtitem = (JoinTreeItem *) lfirst(lc);
1492 :
1493 943092 : deconstruct_distribute(root, jtitem);
1494 : }
1495 :
1496 : /*
1497 : * If there were any special joins then we may have some postponed LEFT
1498 : * JOIN clauses to deal with.
1499 : */
1500 339204 : if (root->join_info_list)
1501 : {
1502 261498 : foreach(lc, item_list)
1503 : {
1504 221784 : JoinTreeItem *jtitem = (JoinTreeItem *) lfirst(lc);
1505 :
1506 221784 : if (jtitem->oj_joinclauses != NIL)
1507 42728 : deconstruct_distribute_oj_quals(root, item_list, jtitem);
1508 : }
1509 : }
1510 :
1511 : /* Don't need the JoinTreeItems any more */
1512 339204 : list_free_deep(item_list);
1513 :
1514 339204 : return result;
1515 : }
1516 :
1517 : /*
1518 : * deconstruct_recurse
1519 : * One recursion level of deconstruct_jointree's initial jointree scan.
1520 : *
1521 : * jtnode is the jointree node to examine, and parent_domain is the
1522 : * enclosing join domain. (We must add all base+OJ relids appearing
1523 : * here or below to parent_domain.) parent_jtitem is the JoinTreeItem
1524 : * for the parent jointree node, or NULL at the top of the recursion.
1525 : *
1526 : * item_list is an in/out parameter: we add a JoinTreeItem struct to
1527 : * that list for each jointree node, in depth-first traversal order.
1528 : * (Hence, after each call, the last list item corresponds to its jtnode.)
1529 : *
1530 : * Return value is the appropriate joinlist for this jointree node.
1531 : */
1532 : static List *
1533 943092 : deconstruct_recurse(PlannerInfo *root, Node *jtnode,
1534 : JoinDomain *parent_domain,
1535 : JoinTreeItem *parent_jtitem,
1536 : List **item_list)
1537 : {
1538 : List *joinlist;
1539 : JoinTreeItem *jtitem;
1540 :
1541 : Assert(jtnode != NULL);
1542 :
1543 : /* Make the new JoinTreeItem, but don't add it to item_list yet */
1544 943092 : jtitem = palloc0_object(JoinTreeItem);
1545 943092 : jtitem->jtnode = jtnode;
1546 943092 : jtitem->jti_parent = parent_jtitem;
1547 :
1548 943092 : if (IsA(jtnode, RangeTblRef))
1549 : {
1550 490434 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1551 :
1552 : /* Fill all_baserels as we encounter baserel jointree nodes */
1553 490434 : root->all_baserels = bms_add_member(root->all_baserels, varno);
1554 : /* This node belongs to parent_domain */
1555 490434 : jtitem->jdomain = parent_domain;
1556 490434 : parent_domain->jd_relids = bms_add_member(parent_domain->jd_relids,
1557 : varno);
1558 : /* qualscope is just the one RTE */
1559 490434 : jtitem->qualscope = bms_make_singleton(varno);
1560 : /* A single baserel does not create an inner join */
1561 490434 : jtitem->inner_join_rels = NULL;
1562 490434 : joinlist = list_make1(jtnode);
1563 : }
1564 452658 : else if (IsA(jtnode, FromExpr))
1565 : {
1566 351646 : FromExpr *f = (FromExpr *) jtnode;
1567 : int remaining;
1568 : ListCell *l;
1569 :
1570 : /* This node belongs to parent_domain, as do its children */
1571 351646 : jtitem->jdomain = parent_domain;
1572 :
1573 : /*
1574 : * Recurse to handle child nodes, and compute output joinlist. We
1575 : * collapse subproblems into a single joinlist whenever the resulting
1576 : * joinlist wouldn't exceed from_collapse_limit members. Also, always
1577 : * collapse one-element subproblems, since that won't lengthen the
1578 : * joinlist anyway.
1579 : */
1580 351646 : jtitem->qualscope = NULL;
1581 351646 : jtitem->inner_join_rels = NULL;
1582 351646 : joinlist = NIL;
1583 351646 : remaining = list_length(f->fromlist);
1584 753510 : foreach(l, f->fromlist)
1585 : {
1586 : JoinTreeItem *sub_item;
1587 : List *sub_joinlist;
1588 : int sub_members;
1589 :
1590 401864 : sub_joinlist = deconstruct_recurse(root, lfirst(l),
1591 : parent_domain,
1592 : jtitem,
1593 : item_list);
1594 401864 : sub_item = (JoinTreeItem *) llast(*item_list);
1595 803728 : jtitem->qualscope = bms_add_members(jtitem->qualscope,
1596 401864 : sub_item->qualscope);
1597 401864 : jtitem->inner_join_rels = sub_item->inner_join_rels;
1598 401864 : sub_members = list_length(sub_joinlist);
1599 401864 : remaining--;
1600 401864 : if (sub_members <= 1 ||
1601 65510 : list_length(joinlist) + sub_members + remaining <= from_collapse_limit)
1602 401852 : joinlist = list_concat(joinlist, sub_joinlist);
1603 : else
1604 12 : joinlist = lappend(joinlist, sub_joinlist);
1605 : }
1606 :
1607 : /*
1608 : * A FROM with more than one list element is an inner join subsuming
1609 : * all below it, so we should report inner_join_rels = qualscope. If
1610 : * there was exactly one element, we should (and already did) report
1611 : * whatever its inner_join_rels were. If there were no elements (is
1612 : * that still possible?) the initialization before the loop fixed it.
1613 : */
1614 351646 : if (list_length(f->fromlist) > 1)
1615 45232 : jtitem->inner_join_rels = jtitem->qualscope;
1616 : }
1617 101012 : else if (IsA(jtnode, JoinExpr))
1618 : {
1619 101012 : JoinExpr *j = (JoinExpr *) jtnode;
1620 : JoinDomain *child_domain,
1621 : *fj_domain;
1622 : JoinTreeItem *left_item,
1623 : *right_item;
1624 : List *leftjoinlist,
1625 : *rightjoinlist;
1626 :
1627 101012 : switch (j->jointype)
1628 : {
1629 46598 : case JOIN_INNER:
1630 : /* This node belongs to parent_domain, as do its children */
1631 46598 : jtitem->jdomain = parent_domain;
1632 : /* Recurse */
1633 46598 : leftjoinlist = deconstruct_recurse(root, j->larg,
1634 : parent_domain,
1635 : jtitem,
1636 : item_list);
1637 46598 : left_item = (JoinTreeItem *) llast(*item_list);
1638 46598 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1639 : parent_domain,
1640 : jtitem,
1641 : item_list);
1642 46598 : right_item = (JoinTreeItem *) llast(*item_list);
1643 : /* Compute qualscope etc */
1644 93196 : jtitem->qualscope = bms_union(left_item->qualscope,
1645 46598 : right_item->qualscope);
1646 46598 : jtitem->inner_join_rels = jtitem->qualscope;
1647 46598 : jtitem->left_rels = left_item->qualscope;
1648 46598 : jtitem->right_rels = right_item->qualscope;
1649 : /* Inner join adds no restrictions for quals */
1650 46598 : jtitem->nonnullable_rels = NULL;
1651 46598 : break;
1652 48346 : case JOIN_LEFT:
1653 : case JOIN_ANTI:
1654 : /* Make new join domain for my quals and the RHS */
1655 48346 : child_domain = makeNode(JoinDomain);
1656 48346 : child_domain->jd_relids = NULL; /* filled by recursion */
1657 48346 : root->join_domains = lappend(root->join_domains, child_domain);
1658 48346 : jtitem->jdomain = child_domain;
1659 : /* Recurse */
1660 48346 : leftjoinlist = deconstruct_recurse(root, j->larg,
1661 : parent_domain,
1662 : jtitem,
1663 : item_list);
1664 48346 : left_item = (JoinTreeItem *) llast(*item_list);
1665 48346 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1666 : child_domain,
1667 : jtitem,
1668 : item_list);
1669 48346 : right_item = (JoinTreeItem *) llast(*item_list);
1670 : /* Compute join domain contents, qualscope etc */
1671 48346 : parent_domain->jd_relids =
1672 48346 : bms_add_members(parent_domain->jd_relids,
1673 48346 : child_domain->jd_relids);
1674 96692 : jtitem->qualscope = bms_union(left_item->qualscope,
1675 48346 : right_item->qualscope);
1676 : /* caution: ANTI join derived from SEMI will lack rtindex */
1677 48346 : if (j->rtindex != 0)
1678 : {
1679 45586 : parent_domain->jd_relids =
1680 45586 : bms_add_member(parent_domain->jd_relids,
1681 : j->rtindex);
1682 45586 : jtitem->qualscope = bms_add_member(jtitem->qualscope,
1683 : j->rtindex);
1684 45586 : root->outer_join_rels = bms_add_member(root->outer_join_rels,
1685 : j->rtindex);
1686 45586 : mark_rels_nulled_by_join(root, j->rtindex,
1687 : right_item->qualscope);
1688 : }
1689 96692 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1690 48346 : right_item->inner_join_rels);
1691 48346 : jtitem->left_rels = left_item->qualscope;
1692 48346 : jtitem->right_rels = right_item->qualscope;
1693 48346 : jtitem->nonnullable_rels = left_item->qualscope;
1694 48346 : break;
1695 5034 : case JOIN_SEMI:
1696 : /* This node belongs to parent_domain, as do its children */
1697 5034 : jtitem->jdomain = parent_domain;
1698 : /* Recurse */
1699 5034 : leftjoinlist = deconstruct_recurse(root, j->larg,
1700 : parent_domain,
1701 : jtitem,
1702 : item_list);
1703 5034 : left_item = (JoinTreeItem *) llast(*item_list);
1704 5034 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1705 : parent_domain,
1706 : jtitem,
1707 : item_list);
1708 5034 : right_item = (JoinTreeItem *) llast(*item_list);
1709 : /* Compute qualscope etc */
1710 10068 : jtitem->qualscope = bms_union(left_item->qualscope,
1711 5034 : right_item->qualscope);
1712 : /* SEMI join never has rtindex, so don't add to anything */
1713 : Assert(j->rtindex == 0);
1714 10068 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1715 5034 : right_item->inner_join_rels);
1716 5034 : jtitem->left_rels = left_item->qualscope;
1717 5034 : jtitem->right_rels = right_item->qualscope;
1718 : /* Semi join adds no restrictions for quals */
1719 5034 : jtitem->nonnullable_rels = NULL;
1720 5034 : break;
1721 1034 : case JOIN_FULL:
1722 : /* The FULL JOIN's quals need their very own domain */
1723 1034 : fj_domain = makeNode(JoinDomain);
1724 1034 : root->join_domains = lappend(root->join_domains, fj_domain);
1725 1034 : jtitem->jdomain = fj_domain;
1726 : /* Recurse, giving each side its own join domain */
1727 1034 : child_domain = makeNode(JoinDomain);
1728 1034 : child_domain->jd_relids = NULL; /* filled by recursion */
1729 1034 : root->join_domains = lappend(root->join_domains, child_domain);
1730 1034 : leftjoinlist = deconstruct_recurse(root, j->larg,
1731 : child_domain,
1732 : jtitem,
1733 : item_list);
1734 1034 : left_item = (JoinTreeItem *) llast(*item_list);
1735 1034 : fj_domain->jd_relids = bms_copy(child_domain->jd_relids);
1736 1034 : child_domain = makeNode(JoinDomain);
1737 1034 : child_domain->jd_relids = NULL; /* filled by recursion */
1738 1034 : root->join_domains = lappend(root->join_domains, child_domain);
1739 1034 : rightjoinlist = deconstruct_recurse(root, j->rarg,
1740 : child_domain,
1741 : jtitem,
1742 : item_list);
1743 1034 : right_item = (JoinTreeItem *) llast(*item_list);
1744 : /* Compute qualscope etc */
1745 2068 : fj_domain->jd_relids = bms_add_members(fj_domain->jd_relids,
1746 1034 : child_domain->jd_relids);
1747 2068 : parent_domain->jd_relids = bms_add_members(parent_domain->jd_relids,
1748 1034 : fj_domain->jd_relids);
1749 2068 : jtitem->qualscope = bms_union(left_item->qualscope,
1750 1034 : right_item->qualscope);
1751 : Assert(j->rtindex != 0);
1752 1034 : parent_domain->jd_relids = bms_add_member(parent_domain->jd_relids,
1753 : j->rtindex);
1754 1034 : jtitem->qualscope = bms_add_member(jtitem->qualscope,
1755 : j->rtindex);
1756 1034 : root->outer_join_rels = bms_add_member(root->outer_join_rels,
1757 : j->rtindex);
1758 1034 : mark_rels_nulled_by_join(root, j->rtindex,
1759 : left_item->qualscope);
1760 1034 : mark_rels_nulled_by_join(root, j->rtindex,
1761 : right_item->qualscope);
1762 2068 : jtitem->inner_join_rels = bms_union(left_item->inner_join_rels,
1763 1034 : right_item->inner_join_rels);
1764 1034 : jtitem->left_rels = left_item->qualscope;
1765 1034 : jtitem->right_rels = right_item->qualscope;
1766 : /* each side is both outer and inner */
1767 1034 : jtitem->nonnullable_rels = jtitem->qualscope;
1768 1034 : break;
1769 0 : default:
1770 : /* JOIN_RIGHT was eliminated during reduce_outer_joins() */
1771 0 : elog(ERROR, "unrecognized join type: %d",
1772 : (int) j->jointype);
1773 : leftjoinlist = rightjoinlist = NIL; /* keep compiler quiet */
1774 : break;
1775 : }
1776 :
1777 : /*
1778 : * Compute the output joinlist. We fold subproblems together except
1779 : * at a FULL JOIN or where join_collapse_limit would be exceeded.
1780 : */
1781 101012 : if (j->jointype == JOIN_FULL)
1782 : {
1783 : /* force the join order exactly at this node */
1784 1034 : joinlist = list_make1(list_make2(leftjoinlist, rightjoinlist));
1785 : }
1786 99978 : else if (list_length(leftjoinlist) + list_length(rightjoinlist) <=
1787 : join_collapse_limit)
1788 : {
1789 : /* OK to combine subproblems */
1790 99810 : joinlist = list_concat(leftjoinlist, rightjoinlist);
1791 : }
1792 : else
1793 : {
1794 : /* can't combine, but needn't force join order above here */
1795 : Node *leftpart,
1796 : *rightpart;
1797 :
1798 : /* avoid creating useless 1-element sublists */
1799 168 : if (list_length(leftjoinlist) == 1)
1800 30 : leftpart = (Node *) linitial(leftjoinlist);
1801 : else
1802 138 : leftpart = (Node *) leftjoinlist;
1803 168 : if (list_length(rightjoinlist) == 1)
1804 24 : rightpart = (Node *) linitial(rightjoinlist);
1805 : else
1806 144 : rightpart = (Node *) rightjoinlist;
1807 168 : joinlist = list_make2(leftpart, rightpart);
1808 : }
1809 : }
1810 : else
1811 : {
1812 0 : elog(ERROR, "unrecognized node type: %d",
1813 : (int) nodeTag(jtnode));
1814 : joinlist = NIL; /* keep compiler quiet */
1815 : }
1816 :
1817 : /* Finally, we can add the new JoinTreeItem to item_list */
1818 943092 : *item_list = lappend(*item_list, jtitem);
1819 :
1820 943092 : return joinlist;
1821 : }
1822 :
1823 : /*
1824 : * deconstruct_distribute
1825 : * Process one jointree node in phase 2 of deconstruct_jointree processing.
1826 : *
1827 : * Distribute quals of the node to appropriate restriction and join lists.
1828 : * In addition, entries will be added to root->join_info_list for outer joins.
1829 : */
1830 : static void
1831 943092 : deconstruct_distribute(PlannerInfo *root, JoinTreeItem *jtitem)
1832 : {
1833 943092 : Node *jtnode = jtitem->jtnode;
1834 :
1835 943092 : if (IsA(jtnode, RangeTblRef))
1836 : {
1837 490434 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1838 :
1839 : /* Deal with any securityQuals attached to the RTE */
1840 490434 : if (root->qual_security_level > 0)
1841 2988 : process_security_barrier_quals(root,
1842 : varno,
1843 : jtitem);
1844 : }
1845 452658 : else if (IsA(jtnode, FromExpr))
1846 : {
1847 351646 : FromExpr *f = (FromExpr *) jtnode;
1848 :
1849 : /*
1850 : * Process any lateral-referencing quals that were postponed to this
1851 : * level by children.
1852 : */
1853 351646 : distribute_quals_to_rels(root, jtitem->lateral_clauses,
1854 : jtitem,
1855 : NULL,
1856 : root->qual_security_level,
1857 : jtitem->qualscope,
1858 : NULL, NULL, NULL,
1859 : true, false, false,
1860 : NULL);
1861 :
1862 : /*
1863 : * Now process the top-level quals.
1864 : */
1865 351646 : distribute_quals_to_rels(root, (List *) f->quals,
1866 : jtitem,
1867 : NULL,
1868 : root->qual_security_level,
1869 : jtitem->qualscope,
1870 : NULL, NULL, NULL,
1871 : true, false, false,
1872 : NULL);
1873 : }
1874 101012 : else if (IsA(jtnode, JoinExpr))
1875 : {
1876 101012 : JoinExpr *j = (JoinExpr *) jtnode;
1877 : Relids ojscope;
1878 : List *my_quals;
1879 : SpecialJoinInfo *sjinfo;
1880 : List **postponed_oj_qual_list;
1881 :
1882 : /*
1883 : * Include lateral-referencing quals postponed from children in
1884 : * my_quals, so that they'll be handled properly in
1885 : * make_outerjoininfo. (This is destructive to
1886 : * jtitem->lateral_clauses, but we won't use that again.)
1887 : */
1888 101012 : my_quals = list_concat(jtitem->lateral_clauses,
1889 101012 : (List *) j->quals);
1890 :
1891 : /*
1892 : * For an OJ, form the SpecialJoinInfo now, so that we can pass it to
1893 : * distribute_qual_to_rels. We must compute its ojscope too.
1894 : *
1895 : * Semijoins are a bit of a hybrid: we build a SpecialJoinInfo, but we
1896 : * want ojscope = NULL for distribute_qual_to_rels.
1897 : */
1898 101012 : if (j->jointype != JOIN_INNER)
1899 : {
1900 54414 : sjinfo = make_outerjoininfo(root,
1901 : jtitem->left_rels,
1902 : jtitem->right_rels,
1903 : jtitem->inner_join_rels,
1904 : j->jointype,
1905 54414 : j->rtindex,
1906 : my_quals);
1907 54414 : jtitem->sjinfo = sjinfo;
1908 54414 : if (j->jointype == JOIN_SEMI)
1909 5034 : ojscope = NULL;
1910 : else
1911 49380 : ojscope = bms_union(sjinfo->min_lefthand,
1912 49380 : sjinfo->min_righthand);
1913 : }
1914 : else
1915 : {
1916 46598 : sjinfo = NULL;
1917 46598 : ojscope = NULL;
1918 : }
1919 :
1920 : /*
1921 : * If it's a left join with a join clause that is strict for the LHS,
1922 : * then we need to postpone handling of any non-degenerate join
1923 : * clauses, in case the join is able to commute with another left join
1924 : * per identity 3. (Degenerate clauses need not be postponed, since
1925 : * they will drop down below this join anyway.)
1926 : */
1927 101012 : if (j->jointype == JOIN_LEFT && sjinfo->lhs_strict)
1928 : {
1929 42728 : postponed_oj_qual_list = &jtitem->oj_joinclauses;
1930 :
1931 : /*
1932 : * Add back any commutable lower OJ relids that were removed from
1933 : * min_lefthand or min_righthand, else the ojscope cross-check in
1934 : * distribute_qual_to_rels will complain. Since we are postponing
1935 : * processing of non-degenerate clauses, this addition doesn't
1936 : * affect anything except that cross-check. Real clause
1937 : * positioning decisions will be made later, when we revisit the
1938 : * postponed clauses.
1939 : */
1940 42728 : ojscope = bms_add_members(ojscope, sjinfo->commute_below_l);
1941 42728 : ojscope = bms_add_members(ojscope, sjinfo->commute_below_r);
1942 : }
1943 : else
1944 58284 : postponed_oj_qual_list = NULL;
1945 :
1946 : /* Process the JOIN's qual clauses */
1947 101012 : distribute_quals_to_rels(root, my_quals,
1948 : jtitem,
1949 : sjinfo,
1950 : root->qual_security_level,
1951 : jtitem->qualscope,
1952 : ojscope, jtitem->nonnullable_rels,
1953 : NULL, /* incompatible_relids */
1954 : true, /* allow_equivalence */
1955 : false, false, /* not clones */
1956 : postponed_oj_qual_list);
1957 :
1958 : /* And add the SpecialJoinInfo to join_info_list */
1959 101012 : if (sjinfo)
1960 54414 : root->join_info_list = lappend(root->join_info_list, sjinfo);
1961 : }
1962 : else
1963 : {
1964 0 : elog(ERROR, "unrecognized node type: %d",
1965 : (int) nodeTag(jtnode));
1966 : }
1967 943092 : }
1968 :
1969 : /*
1970 : * process_security_barrier_quals
1971 : * Transfer security-barrier quals into relation's baserestrictinfo list.
1972 : *
1973 : * The rewriter put any relevant security-barrier conditions into the RTE's
1974 : * securityQuals field, but it's now time to copy them into the rel's
1975 : * baserestrictinfo.
1976 : *
1977 : * In inheritance cases, we only consider quals attached to the parent rel
1978 : * here; they will be valid for all children too, so it's okay to consider
1979 : * them for purposes like equivalence class creation. Quals attached to
1980 : * individual child rels will be dealt with during path creation.
1981 : */
1982 : static void
1983 2988 : process_security_barrier_quals(PlannerInfo *root,
1984 : int rti, JoinTreeItem *jtitem)
1985 : {
1986 2988 : RangeTblEntry *rte = root->simple_rte_array[rti];
1987 2988 : Index security_level = 0;
1988 : ListCell *lc;
1989 :
1990 : /*
1991 : * Each element of the securityQuals list has been preprocessed into an
1992 : * implicitly-ANDed list of clauses. All the clauses in a given sublist
1993 : * should get the same security level, but successive sublists get higher
1994 : * levels.
1995 : */
1996 6118 : foreach(lc, rte->securityQuals)
1997 : {
1998 3130 : List *qualset = (List *) lfirst(lc);
1999 :
2000 : /*
2001 : * We cheat to the extent of passing ojscope = qualscope rather than
2002 : * its more logical value of NULL. The only effect this has is to
2003 : * force a Var-free qual to be evaluated at the rel rather than being
2004 : * pushed up to top of tree, which we don't want.
2005 : */
2006 3130 : distribute_quals_to_rels(root, qualset,
2007 : jtitem,
2008 : NULL,
2009 : security_level,
2010 : jtitem->qualscope,
2011 : jtitem->qualscope,
2012 : NULL,
2013 : NULL,
2014 : true,
2015 : false, false, /* not clones */
2016 : NULL);
2017 3130 : security_level++;
2018 : }
2019 :
2020 : /* Assert that qual_security_level is higher than anything we just used */
2021 : Assert(security_level <= root->qual_security_level);
2022 2988 : }
2023 :
2024 : /*
2025 : * mark_rels_nulled_by_join
2026 : * Fill RelOptInfo.nulling_relids of baserels nulled by this outer join
2027 : *
2028 : * Inputs:
2029 : * ojrelid: RT index of the join RTE (must not be 0)
2030 : * lower_rels: the base+OJ Relids syntactically below nullable side of join
2031 : */
2032 : static void
2033 47654 : mark_rels_nulled_by_join(PlannerInfo *root, Index ojrelid,
2034 : Relids lower_rels)
2035 : {
2036 47654 : int relid = -1;
2037 :
2038 98060 : while ((relid = bms_next_member(lower_rels, relid)) > 0)
2039 : {
2040 50406 : RelOptInfo *rel = root->simple_rel_array[relid];
2041 :
2042 : /* ignore the RTE_GROUP RTE */
2043 50406 : if (relid == root->group_rtindex)
2044 0 : continue;
2045 :
2046 50406 : if (rel == NULL) /* must be an outer join */
2047 : {
2048 : Assert(bms_is_member(relid, root->outer_join_rels));
2049 770 : continue;
2050 : }
2051 49636 : rel->nulling_relids = bms_add_member(rel->nulling_relids, ojrelid);
2052 : }
2053 47654 : }
2054 :
2055 : /*
2056 : * make_outerjoininfo
2057 : * Build a SpecialJoinInfo for the current outer join
2058 : *
2059 : * Inputs:
2060 : * left_rels: the base+OJ Relids syntactically on outer side of join
2061 : * right_rels: the base+OJ Relids syntactically on inner side of join
2062 : * inner_join_rels: base+OJ Relids participating in inner joins below this one
2063 : * jointype: what it says (must always be LEFT, FULL, SEMI, or ANTI)
2064 : * ojrelid: RT index of the join RTE (0 for SEMI, which isn't in the RT list)
2065 : * clause: the outer join's join condition (in implicit-AND format)
2066 : *
2067 : * The node should eventually be appended to root->join_info_list, but we
2068 : * do not do that here.
2069 : *
2070 : * Note: we assume that this function is invoked bottom-up, so that
2071 : * root->join_info_list already contains entries for all outer joins that are
2072 : * syntactically below this one.
2073 : */
2074 : static SpecialJoinInfo *
2075 54414 : make_outerjoininfo(PlannerInfo *root,
2076 : Relids left_rels, Relids right_rels,
2077 : Relids inner_join_rels,
2078 : JoinType jointype, Index ojrelid,
2079 : List *clause)
2080 : {
2081 54414 : SpecialJoinInfo *sjinfo = makeNode(SpecialJoinInfo);
2082 : Relids clause_relids;
2083 : Relids strict_relids;
2084 : Relids min_lefthand;
2085 : Relids min_righthand;
2086 : Relids commute_below_l;
2087 : Relids commute_below_r;
2088 : ListCell *l;
2089 :
2090 : /*
2091 : * We should not see RIGHT JOIN here because left/right were switched
2092 : * earlier
2093 : */
2094 : Assert(jointype != JOIN_INNER);
2095 : Assert(jointype != JOIN_RIGHT);
2096 :
2097 : /*
2098 : * Presently the executor cannot support FOR [KEY] UPDATE/SHARE marking of
2099 : * rels appearing on the nullable side of an outer join. (It's somewhat
2100 : * unclear what that would mean, anyway: what should we mark when a result
2101 : * row is generated from no element of the nullable relation?) So,
2102 : * complain if any nullable rel is FOR [KEY] UPDATE/SHARE.
2103 : *
2104 : * You might be wondering why this test isn't made far upstream in the
2105 : * parser. It's because the parser hasn't got enough info --- consider
2106 : * FOR UPDATE applied to a view. Only after rewriting and flattening do
2107 : * we know whether the view contains an outer join.
2108 : *
2109 : * We use the original RowMarkClause list here; the PlanRowMark list would
2110 : * list everything.
2111 : */
2112 54458 : foreach(l, root->parse->rowMarks)
2113 : {
2114 44 : RowMarkClause *rc = (RowMarkClause *) lfirst(l);
2115 :
2116 44 : if (bms_is_member(rc->rti, right_rels) ||
2117 8 : (jointype == JOIN_FULL && bms_is_member(rc->rti, left_rels)))
2118 0 : ereport(ERROR,
2119 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2120 : /*------
2121 : translator: %s is a SQL row locking clause such as FOR UPDATE */
2122 : errmsg("%s cannot be applied to the nullable side of an outer join",
2123 : LCS_asString(rc->strength))));
2124 : }
2125 :
2126 54414 : sjinfo->syn_lefthand = left_rels;
2127 54414 : sjinfo->syn_righthand = right_rels;
2128 54414 : sjinfo->jointype = jointype;
2129 54414 : sjinfo->ojrelid = ojrelid;
2130 : /* these fields may get added to later: */
2131 54414 : sjinfo->commute_above_l = NULL;
2132 54414 : sjinfo->commute_above_r = NULL;
2133 54414 : sjinfo->commute_below_l = NULL;
2134 54414 : sjinfo->commute_below_r = NULL;
2135 :
2136 54414 : compute_semijoin_info(root, sjinfo, clause);
2137 :
2138 : /* If it's a full join, no need to be very smart */
2139 54414 : if (jointype == JOIN_FULL)
2140 : {
2141 1034 : sjinfo->min_lefthand = bms_copy(left_rels);
2142 1034 : sjinfo->min_righthand = bms_copy(right_rels);
2143 1034 : sjinfo->lhs_strict = false; /* don't care about this */
2144 1034 : return sjinfo;
2145 : }
2146 :
2147 : /*
2148 : * Retrieve all relids mentioned within the join clause.
2149 : */
2150 53380 : clause_relids = pull_varnos(root, (Node *) clause);
2151 :
2152 : /*
2153 : * For which relids is the clause strict, ie, it cannot succeed if the
2154 : * rel's columns are all NULL?
2155 : */
2156 53380 : strict_relids = find_nonnullable_rels((Node *) clause);
2157 :
2158 : /* Remember whether the clause is strict for any LHS relations */
2159 53380 : sjinfo->lhs_strict = bms_overlap(strict_relids, left_rels);
2160 :
2161 : /*
2162 : * Required LHS always includes the LHS rels mentioned in the clause. We
2163 : * may have to add more rels based on lower outer joins; see below.
2164 : */
2165 53380 : min_lefthand = bms_intersect(clause_relids, left_rels);
2166 :
2167 : /*
2168 : * Similarly for required RHS. But here, we must also include any lower
2169 : * inner joins, to ensure we don't try to commute with any of them.
2170 : */
2171 53380 : min_righthand = bms_int_members(bms_union(clause_relids, inner_join_rels),
2172 : right_rels);
2173 :
2174 : /*
2175 : * Now check previous outer joins for ordering restrictions.
2176 : *
2177 : * commute_below_l and commute_below_r accumulate the relids of lower
2178 : * outer joins that we think this one can commute with. These decisions
2179 : * are just tentative within this loop, since we might find an
2180 : * intermediate outer join that prevents commutation. Surviving relids
2181 : * will get merged into the SpecialJoinInfo structs afterwards.
2182 : */
2183 53380 : commute_below_l = commute_below_r = NULL;
2184 71046 : foreach(l, root->join_info_list)
2185 : {
2186 17666 : SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l);
2187 : bool have_unsafe_phvs;
2188 :
2189 : /*
2190 : * A full join is an optimization barrier: we can't associate into or
2191 : * out of it. Hence, if it overlaps either LHS or RHS of the current
2192 : * rel, expand that side's min relset to cover the whole full join.
2193 : */
2194 17666 : if (otherinfo->jointype == JOIN_FULL)
2195 : {
2196 : Assert(otherinfo->ojrelid != 0);
2197 94 : if (bms_overlap(left_rels, otherinfo->syn_lefthand) ||
2198 30 : bms_overlap(left_rels, otherinfo->syn_righthand))
2199 : {
2200 34 : min_lefthand = bms_add_members(min_lefthand,
2201 34 : otherinfo->syn_lefthand);
2202 34 : min_lefthand = bms_add_members(min_lefthand,
2203 34 : otherinfo->syn_righthand);
2204 34 : min_lefthand = bms_add_member(min_lefthand,
2205 34 : otherinfo->ojrelid);
2206 : }
2207 98 : if (bms_overlap(right_rels, otherinfo->syn_lefthand) ||
2208 34 : bms_overlap(right_rels, otherinfo->syn_righthand))
2209 : {
2210 30 : min_righthand = bms_add_members(min_righthand,
2211 30 : otherinfo->syn_lefthand);
2212 30 : min_righthand = bms_add_members(min_righthand,
2213 30 : otherinfo->syn_righthand);
2214 30 : min_righthand = bms_add_member(min_righthand,
2215 30 : otherinfo->ojrelid);
2216 : }
2217 : /* Needn't do anything else with the full join */
2218 64 : continue;
2219 : }
2220 :
2221 : /*
2222 : * If our join condition contains any PlaceHolderVars that need to be
2223 : * evaluated above the lower OJ, then we can't commute with it.
2224 : */
2225 17602 : if (otherinfo->ojrelid != 0)
2226 : have_unsafe_phvs =
2227 17248 : contain_placeholder_references_to(root,
2228 : (Node *) clause,
2229 17248 : otherinfo->ojrelid);
2230 : else
2231 354 : have_unsafe_phvs = false;
2232 :
2233 : /*
2234 : * For a lower OJ in our LHS, if our join condition uses the lower
2235 : * join's RHS and is not strict for that rel, we must preserve the
2236 : * ordering of the two OJs, so add lower OJ's full syntactic relset to
2237 : * min_lefthand. (We must use its full syntactic relset, not just its
2238 : * min_lefthand + min_righthand. This is because there might be other
2239 : * OJs below this one that this one can commute with, but we cannot
2240 : * commute with them if we don't with this one.) Also, if we have
2241 : * unsafe PHVs or the current join is a semijoin or antijoin, we must
2242 : * preserve ordering regardless of strictness.
2243 : *
2244 : * Note: I believe we have to insist on being strict for at least one
2245 : * rel in the lower OJ's min_righthand, not its whole syn_righthand.
2246 : *
2247 : * When we don't need to preserve ordering, check to see if outer join
2248 : * identity 3 applies, and if so, remove the lower OJ's ojrelid from
2249 : * our min_lefthand so that commutation is allowed.
2250 : */
2251 17602 : if (bms_overlap(left_rels, otherinfo->syn_righthand))
2252 : {
2253 16750 : if (bms_overlap(clause_relids, otherinfo->syn_righthand) &&
2254 4858 : (have_unsafe_phvs ||
2255 4858 : jointype == JOIN_SEMI || jointype == JOIN_ANTI ||
2256 4858 : !bms_overlap(strict_relids, otherinfo->min_righthand)))
2257 : {
2258 : /* Preserve ordering */
2259 42 : min_lefthand = bms_add_members(min_lefthand,
2260 42 : otherinfo->syn_lefthand);
2261 42 : min_lefthand = bms_add_members(min_lefthand,
2262 42 : otherinfo->syn_righthand);
2263 42 : if (otherinfo->ojrelid != 0)
2264 42 : min_lefthand = bms_add_member(min_lefthand,
2265 42 : otherinfo->ojrelid);
2266 : }
2267 16708 : else if (jointype == JOIN_LEFT &&
2268 32152 : otherinfo->jointype == JOIN_LEFT &&
2269 16074 : bms_overlap(strict_relids, otherinfo->min_righthand) &&
2270 4828 : !bms_overlap(clause_relids, otherinfo->syn_lefthand))
2271 : {
2272 : /* Identity 3 applies, so remove the ordering restriction */
2273 4774 : min_lefthand = bms_del_member(min_lefthand, otherinfo->ojrelid);
2274 : /* Record the (still tentative) commutability relationship */
2275 : commute_below_l =
2276 4774 : bms_add_member(commute_below_l, otherinfo->ojrelid);
2277 : }
2278 : }
2279 :
2280 : /*
2281 : * For a lower OJ in our RHS, if our join condition does not use the
2282 : * lower join's RHS and the lower OJ's join condition is strict, we
2283 : * can interchange the ordering of the two OJs; otherwise we must add
2284 : * the lower OJ's full syntactic relset to min_righthand.
2285 : *
2286 : * Also, if our join condition does not use the lower join's LHS
2287 : * either, force the ordering to be preserved. Otherwise we can end
2288 : * up with SpecialJoinInfos with identical min_righthands, which can
2289 : * confuse join_is_legal (see discussion in backend/optimizer/README).
2290 : *
2291 : * Also, we must preserve ordering anyway if we have unsafe PHVs, or
2292 : * if either this join or the lower OJ is a semijoin or antijoin.
2293 : *
2294 : * When we don't need to preserve ordering, check to see if outer join
2295 : * identity 3 applies, and if so, remove the lower OJ's ojrelid from
2296 : * our min_righthand so that commutation is allowed.
2297 : */
2298 17602 : if (bms_overlap(right_rels, otherinfo->syn_righthand))
2299 : {
2300 766 : if (bms_overlap(clause_relids, otherinfo->syn_righthand) ||
2301 718 : !bms_overlap(clause_relids, otherinfo->min_lefthand) ||
2302 406 : have_unsafe_phvs ||
2303 310 : jointype == JOIN_SEMI ||
2304 304 : jointype == JOIN_ANTI ||
2305 304 : otherinfo->jointype == JOIN_SEMI ||
2306 244 : otherinfo->jointype == JOIN_ANTI ||
2307 244 : !otherinfo->lhs_strict)
2308 : {
2309 : /* Preserve ordering */
2310 546 : min_righthand = bms_add_members(min_righthand,
2311 546 : otherinfo->syn_lefthand);
2312 546 : min_righthand = bms_add_members(min_righthand,
2313 546 : otherinfo->syn_righthand);
2314 546 : if (otherinfo->ojrelid != 0)
2315 390 : min_righthand = bms_add_member(min_righthand,
2316 390 : otherinfo->ojrelid);
2317 : }
2318 220 : else if (jointype == JOIN_LEFT &&
2319 220 : otherinfo->jointype == JOIN_LEFT &&
2320 220 : otherinfo->lhs_strict)
2321 : {
2322 : /* Identity 3 applies, so remove the ordering restriction */
2323 220 : min_righthand = bms_del_member(min_righthand,
2324 220 : otherinfo->ojrelid);
2325 : /* Record the (still tentative) commutability relationship */
2326 : commute_below_r =
2327 220 : bms_add_member(commute_below_r, otherinfo->ojrelid);
2328 : }
2329 : }
2330 : }
2331 :
2332 : /*
2333 : * Examine PlaceHolderVars. If a PHV is supposed to be evaluated within
2334 : * this join's nullable side, then ensure that min_righthand contains the
2335 : * full eval_at set of the PHV. This ensures that the PHV actually can be
2336 : * evaluated within the RHS. Note that this works only because we should
2337 : * already have determined the final eval_at level for any PHV
2338 : * syntactically within this join.
2339 : */
2340 54816 : foreach(l, root->placeholder_list)
2341 : {
2342 1436 : PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(l);
2343 1436 : Relids ph_syn_level = phinfo->ph_var->phrels;
2344 :
2345 : /* Ignore placeholder if it didn't syntactically come from RHS */
2346 1436 : if (!bms_is_subset(ph_syn_level, right_rels))
2347 520 : continue;
2348 :
2349 : /* Else, prevent join from being formed before we eval the PHV */
2350 916 : min_righthand = bms_add_members(min_righthand, phinfo->ph_eval_at);
2351 : }
2352 :
2353 : /*
2354 : * If we found nothing to put in min_lefthand, punt and make it the full
2355 : * LHS, to avoid having an empty min_lefthand which will confuse later
2356 : * processing. (We don't try to be smart about such cases, just correct.)
2357 : * Likewise for min_righthand.
2358 : */
2359 53380 : if (bms_is_empty(min_lefthand))
2360 1614 : min_lefthand = bms_copy(left_rels);
2361 53380 : if (bms_is_empty(min_righthand))
2362 674 : min_righthand = bms_copy(right_rels);
2363 :
2364 : /* Now they'd better be nonempty */
2365 : Assert(!bms_is_empty(min_lefthand));
2366 : Assert(!bms_is_empty(min_righthand));
2367 : /* Shouldn't overlap either */
2368 : Assert(!bms_overlap(min_lefthand, min_righthand));
2369 :
2370 53380 : sjinfo->min_lefthand = min_lefthand;
2371 53380 : sjinfo->min_righthand = min_righthand;
2372 :
2373 : /*
2374 : * Now that we've identified the correct min_lefthand and min_righthand,
2375 : * any commute_below_l or commute_below_r relids that have not gotten
2376 : * added back into those sets (due to intervening outer joins) are indeed
2377 : * commutable with this one.
2378 : *
2379 : * First, delete any subsequently-added-back relids (this is easier than
2380 : * maintaining commute_below_l/r precisely through all the above).
2381 : */
2382 53380 : commute_below_l = bms_del_members(commute_below_l, min_lefthand);
2383 53380 : commute_below_r = bms_del_members(commute_below_r, min_righthand);
2384 :
2385 : /* Anything left? */
2386 53380 : if (commute_below_l || commute_below_r)
2387 : {
2388 : /* Yup, so we must update the derived data in the SpecialJoinInfos */
2389 4916 : sjinfo->commute_below_l = commute_below_l;
2390 4916 : sjinfo->commute_below_r = commute_below_r;
2391 10762 : foreach(l, root->join_info_list)
2392 : {
2393 5846 : SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l);
2394 :
2395 5846 : if (bms_is_member(otherinfo->ojrelid, commute_below_l))
2396 4774 : otherinfo->commute_above_l =
2397 4774 : bms_add_member(otherinfo->commute_above_l, ojrelid);
2398 1072 : else if (bms_is_member(otherinfo->ojrelid, commute_below_r))
2399 190 : otherinfo->commute_above_r =
2400 190 : bms_add_member(otherinfo->commute_above_r, ojrelid);
2401 : }
2402 : }
2403 :
2404 53380 : return sjinfo;
2405 : }
2406 :
2407 : /*
2408 : * compute_semijoin_info
2409 : * Fill semijoin-related fields of a new SpecialJoinInfo
2410 : *
2411 : * Note: this relies on only the jointype and syn_righthand fields of the
2412 : * SpecialJoinInfo; the rest may not be set yet.
2413 : */
2414 : static void
2415 54414 : compute_semijoin_info(PlannerInfo *root, SpecialJoinInfo *sjinfo, List *clause)
2416 : {
2417 : List *semi_operators;
2418 : List *semi_rhs_exprs;
2419 : bool all_btree;
2420 : bool all_hash;
2421 : ListCell *lc;
2422 :
2423 : /* Initialize semijoin-related fields in case we can't unique-ify */
2424 54414 : sjinfo->semi_can_btree = false;
2425 54414 : sjinfo->semi_can_hash = false;
2426 54414 : sjinfo->semi_operators = NIL;
2427 54414 : sjinfo->semi_rhs_exprs = NIL;
2428 :
2429 : /* Nothing more to do if it's not a semijoin */
2430 54414 : if (sjinfo->jointype != JOIN_SEMI)
2431 49380 : return;
2432 :
2433 : /*
2434 : * Look to see whether the semijoin's join quals consist of AND'ed
2435 : * equality operators, with (only) RHS variables on only one side of each
2436 : * one. If so, we can figure out how to enforce uniqueness for the RHS.
2437 : *
2438 : * Note that the input clause list is the list of quals that are
2439 : * *syntactically* associated with the semijoin, which in practice means
2440 : * the synthesized comparison list for an IN or the WHERE of an EXISTS.
2441 : * Particularly in the latter case, it might contain clauses that aren't
2442 : * *semantically* associated with the join, but refer to just one side or
2443 : * the other. We can ignore such clauses here, as they will just drop
2444 : * down to be processed within one side or the other. (It is okay to
2445 : * consider only the syntactically-associated clauses here because for a
2446 : * semijoin, no higher-level quals could refer to the RHS, and so there
2447 : * can be no other quals that are semantically associated with this join.
2448 : * We do things this way because it is useful to have the set of potential
2449 : * unique-ification expressions before we can extract the list of quals
2450 : * that are actually semantically associated with the particular join.)
2451 : *
2452 : * Note that the semi_operators list consists of the joinqual operators
2453 : * themselves (but commuted if needed to put the RHS value on the right).
2454 : * These could be cross-type operators, in which case the operator
2455 : * actually needed for uniqueness is a related single-type operator. We
2456 : * assume here that that operator will be available from the btree or hash
2457 : * opclass when the time comes ... if not, create_unique_plan() will fail.
2458 : */
2459 5034 : semi_operators = NIL;
2460 5034 : semi_rhs_exprs = NIL;
2461 5034 : all_btree = true;
2462 5034 : all_hash = enable_hashagg; /* don't consider hash if not enabled */
2463 10438 : foreach(lc, clause)
2464 : {
2465 5518 : OpExpr *op = (OpExpr *) lfirst(lc);
2466 : Oid opno;
2467 : Node *left_expr;
2468 : Node *right_expr;
2469 : Relids left_varnos;
2470 : Relids right_varnos;
2471 : Relids all_varnos;
2472 : Oid opinputtype;
2473 :
2474 : /* Is it a binary opclause? */
2475 10928 : if (!IsA(op, OpExpr) ||
2476 5410 : list_length(op->args) != 2)
2477 : {
2478 : /* No, but does it reference both sides? */
2479 108 : all_varnos = pull_varnos(root, (Node *) op);
2480 204 : if (!bms_overlap(all_varnos, sjinfo->syn_righthand) ||
2481 96 : bms_is_subset(all_varnos, sjinfo->syn_righthand))
2482 : {
2483 : /*
2484 : * Clause refers to only one rel, so ignore it --- unless it
2485 : * contains volatile functions, in which case we'd better
2486 : * punt.
2487 : */
2488 96 : if (contain_volatile_functions((Node *) op))
2489 114 : return;
2490 96 : continue;
2491 : }
2492 : /* Non-operator clause referencing both sides, must punt */
2493 12 : return;
2494 : }
2495 :
2496 : /* Extract data from binary opclause */
2497 5410 : opno = op->opno;
2498 5410 : left_expr = linitial(op->args);
2499 5410 : right_expr = lsecond(op->args);
2500 5410 : left_varnos = pull_varnos(root, left_expr);
2501 5410 : right_varnos = pull_varnos(root, right_expr);
2502 5410 : all_varnos = bms_union(left_varnos, right_varnos);
2503 5410 : opinputtype = exprType(left_expr);
2504 :
2505 : /* Does it reference both sides? */
2506 10800 : if (!bms_overlap(all_varnos, sjinfo->syn_righthand) ||
2507 5390 : bms_is_subset(all_varnos, sjinfo->syn_righthand))
2508 : {
2509 : /*
2510 : * Clause refers to only one rel, so ignore it --- unless it
2511 : * contains volatile functions, in which case we'd better punt.
2512 : */
2513 130 : if (contain_volatile_functions((Node *) op))
2514 0 : return;
2515 130 : continue;
2516 : }
2517 :
2518 : /* check rel membership of arguments */
2519 10560 : if (!bms_is_empty(right_varnos) &&
2520 5280 : bms_is_subset(right_varnos, sjinfo->syn_righthand) &&
2521 4820 : !bms_overlap(left_varnos, sjinfo->syn_righthand))
2522 : {
2523 : /* typical case, right_expr is RHS variable */
2524 : }
2525 920 : else if (!bms_is_empty(left_varnos) &&
2526 460 : bms_is_subset(left_varnos, sjinfo->syn_righthand) &&
2527 454 : !bms_overlap(right_varnos, sjinfo->syn_righthand))
2528 : {
2529 : /* flipped case, left_expr is RHS variable */
2530 454 : opno = get_commutator(opno);
2531 454 : if (!OidIsValid(opno))
2532 0 : return;
2533 454 : right_expr = left_expr;
2534 : }
2535 : else
2536 : {
2537 : /* mixed membership of args, punt */
2538 6 : return;
2539 : }
2540 :
2541 : /* all operators must be btree equality or hash equality */
2542 5274 : if (all_btree)
2543 : {
2544 : /* oprcanmerge is considered a hint... */
2545 10452 : if (!op_mergejoinable(opno, opinputtype) ||
2546 5178 : get_mergejoin_opfamilies(opno) == NIL)
2547 96 : all_btree = false;
2548 : }
2549 5274 : if (all_hash)
2550 : {
2551 : /* ... but oprcanhash had better be correct */
2552 5202 : if (!op_hashjoinable(opno, opinputtype))
2553 96 : all_hash = false;
2554 : }
2555 5274 : if (!(all_btree || all_hash))
2556 96 : return;
2557 :
2558 : /* so far so good, keep building lists */
2559 5178 : semi_operators = lappend_oid(semi_operators, opno);
2560 5178 : semi_rhs_exprs = lappend(semi_rhs_exprs, copyObject(right_expr));
2561 : }
2562 :
2563 : /* Punt if we didn't find at least one column to unique-ify */
2564 4920 : if (semi_rhs_exprs == NIL)
2565 12 : return;
2566 :
2567 : /*
2568 : * The expressions we'd need to unique-ify mustn't be volatile.
2569 : */
2570 4908 : if (contain_volatile_functions((Node *) semi_rhs_exprs))
2571 0 : return;
2572 :
2573 : /*
2574 : * If we get here, we can unique-ify the semijoin's RHS using at least one
2575 : * of sorting and hashing. Save the information about how to do that.
2576 : */
2577 4908 : sjinfo->semi_can_btree = all_btree;
2578 4908 : sjinfo->semi_can_hash = all_hash;
2579 4908 : sjinfo->semi_operators = semi_operators;
2580 4908 : sjinfo->semi_rhs_exprs = semi_rhs_exprs;
2581 : }
2582 :
2583 : /*
2584 : * deconstruct_distribute_oj_quals
2585 : * Adjust LEFT JOIN quals to be suitable for commuted-left-join cases,
2586 : * then push them into the joinqual lists and EquivalenceClass structures.
2587 : *
2588 : * This runs immediately after we've completed the deconstruct_distribute scan.
2589 : * jtitems contains all the JoinTreeItems (in depth-first order), and jtitem
2590 : * is one that has postponed oj_joinclauses to deal with.
2591 : */
2592 : static void
2593 42728 : deconstruct_distribute_oj_quals(PlannerInfo *root,
2594 : List *jtitems,
2595 : JoinTreeItem *jtitem)
2596 : {
2597 42728 : SpecialJoinInfo *sjinfo = jtitem->sjinfo;
2598 : Relids qualscope,
2599 : ojscope,
2600 : nonnullable_rels;
2601 :
2602 : /* Recompute syntactic and semantic scopes of this left join */
2603 42728 : qualscope = bms_union(sjinfo->syn_lefthand, sjinfo->syn_righthand);
2604 42728 : qualscope = bms_add_member(qualscope, sjinfo->ojrelid);
2605 42728 : ojscope = bms_union(sjinfo->min_lefthand, sjinfo->min_righthand);
2606 42728 : nonnullable_rels = sjinfo->syn_lefthand;
2607 :
2608 : /*
2609 : * If this join can commute with any other ones per outer-join identity 3,
2610 : * and it is the one providing the join clause with flexible semantics,
2611 : * then we have to generate variants of the join clause with different
2612 : * nullingrels labeling. Otherwise, just push out the postponed clause
2613 : * as-is.
2614 : */
2615 : Assert(sjinfo->lhs_strict); /* else we shouldn't be here */
2616 42728 : if (sjinfo->commute_above_r || sjinfo->commute_below_l)
2617 4928 : {
2618 : Relids joins_above;
2619 : Relids joins_below;
2620 : Relids incompatible_joins;
2621 : Relids joins_so_far;
2622 : List *quals;
2623 : int save_last_rinfo_serial;
2624 : ListCell *lc;
2625 :
2626 : /* Identify the outer joins this one commutes with */
2627 4928 : joins_above = sjinfo->commute_above_r;
2628 4928 : joins_below = sjinfo->commute_below_l;
2629 :
2630 : /*
2631 : * Generate qual variants with different sets of nullingrels bits.
2632 : *
2633 : * We only need bit-sets that correspond to the successively less
2634 : * deeply syntactically-nested subsets of this join and its
2635 : * commutators. That's true first because obviously only those forms
2636 : * of the Vars and PHVs could appear elsewhere in the query, and
2637 : * second because the outer join identities do not provide a way to
2638 : * re-order such joins in a way that would require different marking.
2639 : * (That is, while the current join may commute with several others,
2640 : * none of those others can commute with each other.) To visit the
2641 : * interesting joins in syntactic nesting order, we rely on the
2642 : * jtitems list to be ordered that way.
2643 : *
2644 : * We first strip out all the nullingrels bits corresponding to
2645 : * commuting joins below this one, and then successively put them back
2646 : * as we crawl up the join stack.
2647 : */
2648 4928 : quals = jtitem->oj_joinclauses;
2649 4928 : if (!bms_is_empty(joins_below))
2650 4738 : quals = (List *) remove_nulling_relids((Node *) quals,
2651 : joins_below,
2652 : NULL);
2653 :
2654 : /*
2655 : * We'll need to mark the lower versions of the quals as not safe to
2656 : * apply above not-yet-processed joins of the stack. This prevents
2657 : * possibly applying a cloned qual at the wrong join level.
2658 : */
2659 4928 : incompatible_joins = bms_union(joins_below, joins_above);
2660 4928 : incompatible_joins = bms_add_member(incompatible_joins,
2661 4928 : sjinfo->ojrelid);
2662 :
2663 : /*
2664 : * Each time we produce RestrictInfo(s) from these quals, reset the
2665 : * last_rinfo_serial counter, so that the RestrictInfos for the "same"
2666 : * qual condition get identical serial numbers. (This relies on the
2667 : * fact that we're not changing the qual list in any way that'd affect
2668 : * the number of RestrictInfos built from it.) This'll allow us to
2669 : * detect duplicative qual usage later.
2670 : */
2671 4928 : save_last_rinfo_serial = root->last_rinfo_serial;
2672 :
2673 4928 : joins_so_far = NULL;
2674 42984 : foreach(lc, jtitems)
2675 : {
2676 38056 : JoinTreeItem *otherjtitem = (JoinTreeItem *) lfirst(lc);
2677 38056 : SpecialJoinInfo *othersj = otherjtitem->sjinfo;
2678 38056 : bool below_sjinfo = false;
2679 38056 : bool above_sjinfo = false;
2680 : Relids this_qualscope;
2681 : Relids this_ojscope;
2682 : bool allow_equivalence,
2683 : has_clone,
2684 : is_clone;
2685 :
2686 38056 : if (othersj == NULL)
2687 27026 : continue; /* not an outer-join item, ignore */
2688 :
2689 11030 : if (bms_is_member(othersj->ojrelid, joins_below))
2690 : {
2691 : /* othersj commutes with sjinfo from below left */
2692 4774 : below_sjinfo = true;
2693 : }
2694 6256 : else if (othersj == sjinfo)
2695 : {
2696 : /* found our join in syntactic order */
2697 : Assert(bms_equal(joins_so_far, joins_below));
2698 : }
2699 1328 : else if (bms_is_member(othersj->ojrelid, joins_above))
2700 : {
2701 : /* othersj commutes with sjinfo from above */
2702 190 : above_sjinfo = true;
2703 : }
2704 : else
2705 : {
2706 : /* othersj is not relevant, ignore */
2707 1138 : continue;
2708 : }
2709 :
2710 : /* Reset serial counter for this version of the quals */
2711 9892 : root->last_rinfo_serial = save_last_rinfo_serial;
2712 :
2713 : /*
2714 : * When we are looking at joins above sjinfo, we are envisioning
2715 : * pushing sjinfo to above othersj, so add othersj's nulling bit
2716 : * before distributing the quals. We should add it to Vars coming
2717 : * from the current join's LHS: we want to transform the second
2718 : * form of OJ identity 3 to the first form, in which Vars of
2719 : * relation B will appear nulled by the syntactically-upper OJ
2720 : * within the Pbc clause, but those of relation C will not. (In
2721 : * the notation used by optimizer/README, we're converting a qual
2722 : * of the form Pbc to Pb*c.) Of course, we must also remove that
2723 : * bit from the incompatible_joins value, else we'll make a qual
2724 : * that can't be placed anywhere.
2725 : */
2726 9892 : if (above_sjinfo)
2727 : {
2728 : quals = (List *)
2729 190 : add_nulling_relids((Node *) quals,
2730 190 : sjinfo->syn_lefthand,
2731 190 : bms_make_singleton(othersj->ojrelid));
2732 190 : incompatible_joins = bms_del_member(incompatible_joins,
2733 190 : othersj->ojrelid);
2734 : }
2735 :
2736 : /* Compute qualscope and ojscope for this join level */
2737 9892 : this_qualscope = bms_union(qualscope, joins_so_far);
2738 9892 : this_ojscope = bms_union(ojscope, joins_so_far);
2739 9892 : if (above_sjinfo)
2740 : {
2741 : /* othersj is not yet in joins_so_far, but we need it */
2742 190 : this_qualscope = bms_add_member(this_qualscope,
2743 190 : othersj->ojrelid);
2744 190 : this_ojscope = bms_add_member(this_ojscope,
2745 190 : othersj->ojrelid);
2746 : /* sjinfo is in joins_so_far, and we don't want it */
2747 190 : this_ojscope = bms_del_member(this_ojscope,
2748 190 : sjinfo->ojrelid);
2749 : }
2750 :
2751 : /*
2752 : * We generate EquivalenceClasses only from the first form of the
2753 : * quals, with the fewest nullingrels bits set. An EC made from
2754 : * this version of the quals can be useful below the outer-join
2755 : * nest, whereas versions with some nullingrels bits set would not
2756 : * be. We cannot generate ECs from more than one version, or
2757 : * we'll make nonsensical conclusions that Vars with nullingrels
2758 : * bits set are equal to their versions without. Fortunately,
2759 : * such ECs wouldn't be very useful anyway, because they'd equate
2760 : * values not observable outside the join nest. (See
2761 : * optimizer/README.)
2762 : *
2763 : * The first form of the quals is also the only one marked as
2764 : * has_clone rather than is_clone.
2765 : */
2766 9892 : allow_equivalence = (joins_so_far == NULL);
2767 9892 : has_clone = allow_equivalence;
2768 9892 : is_clone = !has_clone;
2769 :
2770 9892 : distribute_quals_to_rels(root, quals,
2771 : otherjtitem,
2772 : sjinfo,
2773 : root->qual_security_level,
2774 : this_qualscope,
2775 : this_ojscope, nonnullable_rels,
2776 : bms_copy(incompatible_joins),
2777 : allow_equivalence,
2778 : has_clone,
2779 : is_clone,
2780 : NULL); /* no more postponement */
2781 :
2782 : /*
2783 : * Adjust qual nulling bits for next level up, if needed. We
2784 : * don't want to put sjinfo's own bit in at all, and if we're
2785 : * above sjinfo then we did it already. Here, we should mark all
2786 : * Vars coming from the lower join's RHS. (Again, we are
2787 : * converting a qual of the form Pbc to Pb*c, but now we are
2788 : * putting back bits that were there in the parser output and were
2789 : * temporarily stripped above.) Update incompatible_joins too.
2790 : */
2791 9892 : if (below_sjinfo)
2792 : {
2793 : quals = (List *)
2794 4774 : add_nulling_relids((Node *) quals,
2795 4774 : othersj->syn_righthand,
2796 4774 : bms_make_singleton(othersj->ojrelid));
2797 4774 : incompatible_joins = bms_del_member(incompatible_joins,
2798 4774 : othersj->ojrelid);
2799 : }
2800 :
2801 : /* ... and track joins processed so far */
2802 9892 : joins_so_far = bms_add_member(joins_so_far, othersj->ojrelid);
2803 : }
2804 : }
2805 : else
2806 : {
2807 : /* No commutation possible, just process the postponed clauses */
2808 37800 : distribute_quals_to_rels(root, jtitem->oj_joinclauses,
2809 : jtitem,
2810 : sjinfo,
2811 : root->qual_security_level,
2812 : qualscope,
2813 : ojscope, nonnullable_rels,
2814 : NULL, /* incompatible_relids */
2815 : true, /* allow_equivalence */
2816 : false, false, /* not clones */
2817 : NULL); /* no more postponement */
2818 : }
2819 42728 : }
2820 :
2821 :
2822 : /*****************************************************************************
2823 : *
2824 : * QUALIFICATIONS
2825 : *
2826 : *****************************************************************************/
2827 :
2828 : /*
2829 : * distribute_quals_to_rels
2830 : * Convenience routine to apply distribute_qual_to_rels to each element
2831 : * of an AND'ed list of clauses.
2832 : */
2833 : static void
2834 855126 : distribute_quals_to_rels(PlannerInfo *root, List *clauses,
2835 : JoinTreeItem *jtitem,
2836 : SpecialJoinInfo *sjinfo,
2837 : Index security_level,
2838 : Relids qualscope,
2839 : Relids ojscope,
2840 : Relids outerjoin_nonnullable,
2841 : Relids incompatible_relids,
2842 : bool allow_equivalence,
2843 : bool has_clone,
2844 : bool is_clone,
2845 : List **postponed_oj_qual_list)
2846 : {
2847 : ListCell *lc;
2848 :
2849 1456130 : foreach(lc, clauses)
2850 : {
2851 601004 : Node *clause = (Node *) lfirst(lc);
2852 :
2853 601004 : distribute_qual_to_rels(root, clause,
2854 : jtitem,
2855 : sjinfo,
2856 : security_level,
2857 : qualscope,
2858 : ojscope,
2859 : outerjoin_nonnullable,
2860 : incompatible_relids,
2861 : allow_equivalence,
2862 : has_clone,
2863 : is_clone,
2864 : postponed_oj_qual_list);
2865 : }
2866 855126 : }
2867 :
2868 : /*
2869 : * distribute_qual_to_rels
2870 : * Add clause information to either the baserestrictinfo or joininfo list
2871 : * (depending on whether the clause is a join) of each base relation
2872 : * mentioned in the clause. A RestrictInfo node is created and added to
2873 : * the appropriate list for each rel. Alternatively, if the clause uses a
2874 : * mergejoinable operator, enter its left- and right-side expressions into
2875 : * the query's EquivalenceClasses.
2876 : *
2877 : * In some cases, quals will be added to parent jtitems' lateral_clauses
2878 : * or to postponed_oj_qual_list instead of being processed right away.
2879 : * These will be dealt with in later calls of deconstruct_distribute.
2880 : *
2881 : * 'clause': the qual clause to be distributed
2882 : * 'jtitem': the JoinTreeItem for the containing jointree node
2883 : * 'sjinfo': join's SpecialJoinInfo (NULL for an inner join or WHERE clause)
2884 : * 'security_level': security_level to assign to the qual
2885 : * 'qualscope': set of base+OJ rels the qual's syntactic scope covers
2886 : * 'ojscope': NULL if not an outer-join qual, else the minimum set of base+OJ
2887 : * rels needed to form this join
2888 : * 'outerjoin_nonnullable': NULL if not an outer-join qual, else the set of
2889 : * base+OJ rels appearing on the outer (nonnullable) side of the join
2890 : * (for FULL JOIN this includes both sides of the join, and must in fact
2891 : * equal qualscope)
2892 : * 'incompatible_relids': the set of outer-join relid(s) that must not be
2893 : * computed below this qual. We only bother to compute this for
2894 : * "clone" quals, otherwise it can be left NULL.
2895 : * 'allow_equivalence': true if it's okay to convert clause into an
2896 : * EquivalenceClass
2897 : * 'has_clone': has_clone property to assign to the qual
2898 : * 'is_clone': is_clone property to assign to the qual
2899 : * 'postponed_oj_qual_list': if not NULL, non-degenerate outer join clauses
2900 : * should be added to this list instead of being processed (list entries
2901 : * are just the bare clauses)
2902 : *
2903 : * 'qualscope' identifies what level of JOIN the qual came from syntactically.
2904 : * 'ojscope' is needed if we decide to force the qual up to the outer-join
2905 : * level, which will be ojscope not necessarily qualscope.
2906 : *
2907 : * At the time this is called, root->join_info_list must contain entries for
2908 : * at least those special joins that are syntactically below this qual.
2909 : * (We now need that only for detection of redundant IS NULL quals.)
2910 : */
2911 : static void
2912 601004 : distribute_qual_to_rels(PlannerInfo *root, Node *clause,
2913 : JoinTreeItem *jtitem,
2914 : SpecialJoinInfo *sjinfo,
2915 : Index security_level,
2916 : Relids qualscope,
2917 : Relids ojscope,
2918 : Relids outerjoin_nonnullable,
2919 : Relids incompatible_relids,
2920 : bool allow_equivalence,
2921 : bool has_clone,
2922 : bool is_clone,
2923 : List **postponed_oj_qual_list)
2924 : {
2925 : Relids relids;
2926 : bool is_pushed_down;
2927 601004 : bool pseudoconstant = false;
2928 : bool maybe_equivalence;
2929 : bool maybe_outer_join;
2930 : RestrictInfo *restrictinfo;
2931 :
2932 : /*
2933 : * Retrieve all relids mentioned within the clause.
2934 : */
2935 601004 : relids = pull_varnos(root, clause);
2936 :
2937 : /*
2938 : * In ordinary SQL, a WHERE or JOIN/ON clause can't reference any rels
2939 : * that aren't within its syntactic scope; however, if we pulled up a
2940 : * LATERAL subquery then we might find such references in quals that have
2941 : * been pulled up. We need to treat such quals as belonging to the join
2942 : * level that includes every rel they reference. Although we could make
2943 : * pull_up_subqueries() place such quals correctly to begin with, it's
2944 : * easier to handle it here. When we find a clause that contains Vars
2945 : * outside its syntactic scope, locate the nearest parent join level that
2946 : * includes all the required rels and add the clause to that level's
2947 : * lateral_clauses list. We'll process it when we reach that join level.
2948 : */
2949 601004 : if (!bms_is_subset(relids, qualscope))
2950 : {
2951 : JoinTreeItem *pitem;
2952 :
2953 : Assert(root->hasLateralRTEs); /* shouldn't happen otherwise */
2954 : Assert(sjinfo == NULL); /* mustn't postpone past outer join */
2955 116 : for (pitem = jtitem->jti_parent; pitem; pitem = pitem->jti_parent)
2956 : {
2957 116 : if (bms_is_subset(relids, pitem->qualscope))
2958 : {
2959 110 : pitem->lateral_clauses = lappend(pitem->lateral_clauses,
2960 : clause);
2961 422600 : return;
2962 : }
2963 :
2964 : /*
2965 : * We should not be postponing any quals past an outer join. If
2966 : * this Assert fires, pull_up_subqueries() messed up.
2967 : */
2968 : Assert(pitem->sjinfo == NULL);
2969 : }
2970 0 : elog(ERROR, "failed to postpone qual containing lateral reference");
2971 : }
2972 :
2973 : /*
2974 : * If it's an outer-join clause, also check that relids is a subset of
2975 : * ojscope. (This should not fail if the syntactic scope check passed.)
2976 : */
2977 600894 : if (ojscope && !bms_is_subset(relids, ojscope))
2978 0 : elog(ERROR, "JOIN qualification cannot refer to other relations");
2979 :
2980 : /*
2981 : * If the clause is variable-free, our normal heuristic for pushing it
2982 : * down to just the mentioned rels doesn't work, because there are none.
2983 : *
2984 : * If the clause is an outer-join clause, we must force it to the OJ's
2985 : * semantic level to preserve semantics.
2986 : *
2987 : * Otherwise, when the clause contains volatile functions, we force it to
2988 : * be evaluated at its original syntactic level. This preserves the
2989 : * expected semantics.
2990 : *
2991 : * When the clause contains no volatile functions either, it is actually a
2992 : * pseudoconstant clause that will not change value during any one
2993 : * execution of the plan, and hence can be used as a one-time qual in a
2994 : * gating Result plan node. We put such a clause into the regular
2995 : * RestrictInfo lists for the moment, but eventually createplan.c will
2996 : * pull it out and make a gating Result node immediately above whatever
2997 : * plan node the pseudoconstant clause is assigned to. It's usually best
2998 : * to put a gating node as high in the plan tree as possible.
2999 : */
3000 600894 : if (bms_is_empty(relids))
3001 : {
3002 11182 : if (ojscope)
3003 : {
3004 : /* clause is attached to outer join, eval it there */
3005 404 : relids = bms_copy(ojscope);
3006 : /* mustn't use as gating qual, so don't mark pseudoconstant */
3007 : }
3008 10778 : else if (contain_volatile_functions(clause))
3009 : {
3010 : /* eval at original syntactic level */
3011 174 : relids = bms_copy(qualscope);
3012 : /* again, can't mark pseudoconstant */
3013 : }
3014 : else
3015 : {
3016 : /*
3017 : * If we are in the top-level join domain, we can push the qual to
3018 : * the top of the plan tree. Otherwise, be conservative and eval
3019 : * it at original syntactic level. (Ideally we'd push it to the
3020 : * top of the current join domain in all cases, but that causes
3021 : * problems if we later rearrange outer-join evaluation order.
3022 : * Pseudoconstant quals below the top level are a pretty odd case,
3023 : * so it's not clear that it's worth working hard on.)
3024 : */
3025 10604 : if (jtitem->jdomain == (JoinDomain *) linitial(root->join_domains))
3026 10544 : relids = bms_copy(jtitem->jdomain->jd_relids);
3027 : else
3028 60 : relids = bms_copy(qualscope);
3029 : /* mark as gating qual */
3030 10604 : pseudoconstant = true;
3031 : /* tell createplan.c to check for gating quals */
3032 10604 : root->hasPseudoConstantQuals = true;
3033 : }
3034 : }
3035 :
3036 : /*----------
3037 : * Check to see if clause application must be delayed by outer-join
3038 : * considerations.
3039 : *
3040 : * A word about is_pushed_down: we mark the qual as "pushed down" if
3041 : * it is (potentially) applicable at a level different from its original
3042 : * syntactic level. This flag is used to distinguish OUTER JOIN ON quals
3043 : * from other quals pushed down to the same joinrel. The rules are:
3044 : * WHERE quals and INNER JOIN quals: is_pushed_down = true.
3045 : * Non-degenerate OUTER JOIN quals: is_pushed_down = false.
3046 : * Degenerate OUTER JOIN quals: is_pushed_down = true.
3047 : * A "degenerate" OUTER JOIN qual is one that doesn't mention the
3048 : * non-nullable side, and hence can be pushed down into the nullable side
3049 : * without changing the join result. It is correct to treat it as a
3050 : * regular filter condition at the level where it is evaluated.
3051 : *
3052 : * Note: it is not immediately obvious that a simple boolean is enough
3053 : * for this: if for some reason we were to attach a degenerate qual to
3054 : * its original join level, it would need to be treated as an outer join
3055 : * qual there. However, this cannot happen, because all the rels the
3056 : * clause mentions must be in the outer join's min_righthand, therefore
3057 : * the join it needs must be formed before the outer join; and we always
3058 : * attach quals to the lowest level where they can be evaluated. But
3059 : * if we were ever to re-introduce a mechanism for delaying evaluation
3060 : * of "expensive" quals, this area would need work.
3061 : *
3062 : * Note: generally, use of is_pushed_down has to go through the macro
3063 : * RINFO_IS_PUSHED_DOWN, because that flag alone is not always sufficient
3064 : * to tell whether a clause must be treated as pushed-down in context.
3065 : * This seems like another reason why it should perhaps be rethought.
3066 : *----------
3067 : */
3068 600894 : if (bms_overlap(relids, outerjoin_nonnullable))
3069 : {
3070 : /*
3071 : * The qual is attached to an outer join and mentions (some of the)
3072 : * rels on the nonnullable side, so it's not degenerate. If the
3073 : * caller wants to postpone handling such clauses, just add it to
3074 : * postponed_oj_qual_list and return. (The work we've done up to here
3075 : * will have to be redone later, but there's not much of it.)
3076 : */
3077 106804 : if (postponed_oj_qual_list != NULL)
3078 : {
3079 47372 : *postponed_oj_qual_list = lappend(*postponed_oj_qual_list, clause);
3080 47372 : return;
3081 : }
3082 :
3083 : /*
3084 : * We can't use such a clause to deduce equivalence (the left and
3085 : * right sides might be unequal above the join because one of them has
3086 : * gone to NULL) ... but we might be able to use it for more limited
3087 : * deductions, if it is mergejoinable. So consider adding it to the
3088 : * lists of set-aside outer-join clauses.
3089 : */
3090 59432 : is_pushed_down = false;
3091 59432 : maybe_equivalence = false;
3092 59432 : maybe_outer_join = true;
3093 :
3094 : /*
3095 : * Now force the qual to be evaluated exactly at the level of joining
3096 : * corresponding to the outer join. We cannot let it get pushed down
3097 : * into the nonnullable side, since then we'd produce no output rows,
3098 : * rather than the intended single null-extended row, for any
3099 : * nonnullable-side rows failing the qual.
3100 : */
3101 : Assert(ojscope);
3102 59432 : relids = ojscope;
3103 : Assert(!pseudoconstant);
3104 : }
3105 : else
3106 : {
3107 : /*
3108 : * Normal qual clause or degenerate outer-join clause. Either way, we
3109 : * can mark it as pushed-down.
3110 : */
3111 494090 : is_pushed_down = true;
3112 :
3113 : /*
3114 : * It's possible that this is an IS NULL clause that's redundant with
3115 : * a lower antijoin; if so we can just discard it. We need not test
3116 : * in any of the other cases, because this will only be possible for
3117 : * pushed-down clauses.
3118 : */
3119 494090 : if (check_redundant_nullability_qual(root, clause))
3120 1156 : return;
3121 :
3122 : /* Feed qual to the equivalence machinery, if allowed by caller */
3123 492934 : maybe_equivalence = allow_equivalence;
3124 :
3125 : /*
3126 : * Since it doesn't mention the LHS, it's certainly not useful as a
3127 : * set-aside OJ clause, even if it's in an OJ.
3128 : */
3129 492934 : maybe_outer_join = false;
3130 : }
3131 :
3132 : /*
3133 : * Build the RestrictInfo node itself.
3134 : */
3135 552366 : restrictinfo = make_restrictinfo(root,
3136 : (Expr *) clause,
3137 : is_pushed_down,
3138 : has_clone,
3139 : is_clone,
3140 : pseudoconstant,
3141 : security_level,
3142 : relids,
3143 : incompatible_relids,
3144 : outerjoin_nonnullable);
3145 :
3146 : /*
3147 : * If it's a join clause, add vars used in the clause to targetlists of
3148 : * their relations, so that they will be emitted by the plan nodes that
3149 : * scan those relations (else they won't be available at the join node!).
3150 : *
3151 : * Normally we mark the vars as needed at the join identified by "relids".
3152 : * However, if this is a clone clause then ignore the outer-join relids in
3153 : * that set. Otherwise, vars appearing in a cloned clause would end up
3154 : * marked as having to propagate to the highest one of the commuting
3155 : * joins, which would often be an overestimate. For such clauses, correct
3156 : * var propagation is ensured by making ojscope include input rels from
3157 : * both sides of the join.
3158 : *
3159 : * See also rebuild_joinclause_attr_needed, which has to partially repeat
3160 : * this work after removal of an outer join.
3161 : *
3162 : * Note: if the clause gets absorbed into an EquivalenceClass then this
3163 : * may be unnecessary, but for now we have to do it to cover the case
3164 : * where the EC becomes ec_broken and we end up reinserting the original
3165 : * clauses into the plan.
3166 : */
3167 552366 : if (bms_membership(relids) == BMS_MULTIPLE)
3168 : {
3169 164348 : List *vars = pull_var_clause(clause,
3170 : PVC_RECURSE_AGGREGATES |
3171 : PVC_RECURSE_WINDOWFUNCS |
3172 : PVC_INCLUDE_PLACEHOLDERS);
3173 : Relids where_needed;
3174 :
3175 164348 : if (is_clone)
3176 5378 : where_needed = bms_intersect(relids, root->all_baserels);
3177 : else
3178 158970 : where_needed = relids;
3179 164348 : add_vars_to_targetlist(root, vars, where_needed);
3180 164348 : list_free(vars);
3181 : }
3182 :
3183 : /*
3184 : * We check "mergejoinability" of every clause, not only join clauses,
3185 : * because we want to know about equivalences between vars of the same
3186 : * relation, or between vars and consts.
3187 : */
3188 552366 : check_mergejoinable(restrictinfo);
3189 :
3190 : /*
3191 : * If it is a true equivalence clause, send it to the EquivalenceClass
3192 : * machinery. We do *not* attach it directly to any restriction or join
3193 : * lists. The EC code will propagate it to the appropriate places later.
3194 : *
3195 : * If the clause has a mergejoinable operator, yet isn't an equivalence
3196 : * because it is an outer-join clause, the EC code may still be able to do
3197 : * something with it. We add it to appropriate lists for further
3198 : * consideration later. Specifically:
3199 : *
3200 : * If it is a left or right outer-join qualification that relates the two
3201 : * sides of the outer join (no funny business like leftvar1 = leftvar2 +
3202 : * rightvar), we add it to root->left_join_clauses or
3203 : * root->right_join_clauses according to which side the nonnullable
3204 : * variable appears on.
3205 : *
3206 : * If it is a full outer-join qualification, we add it to
3207 : * root->full_join_clauses. (Ideally we'd discard cases that aren't
3208 : * leftvar = rightvar, as we do for left/right joins, but this routine
3209 : * doesn't have the info needed to do that; and the current usage of the
3210 : * full_join_clauses list doesn't require that, so it's not currently
3211 : * worth complicating this routine's API to make it possible.)
3212 : *
3213 : * If none of the above hold, pass it off to
3214 : * distribute_restrictinfo_to_rels().
3215 : *
3216 : * In all cases, it's important to initialize the left_ec and right_ec
3217 : * fields of a mergejoinable clause, so that all possibly mergejoinable
3218 : * expressions have representations in EquivalenceClasses. If
3219 : * process_equivalence is successful, it will take care of that;
3220 : * otherwise, we have to call initialize_mergeclause_eclasses to do it.
3221 : */
3222 552366 : if (restrictinfo->mergeopfamilies)
3223 : {
3224 375128 : if (maybe_equivalence)
3225 : {
3226 317186 : if (process_equivalence(root, &restrictinfo, jtitem->jdomain))
3227 316924 : return;
3228 : /* EC rejected it, so set left_ec/right_ec the hard way ... */
3229 262 : if (restrictinfo->mergeopfamilies) /* EC might have changed this */
3230 208 : initialize_mergeclause_eclasses(root, restrictinfo);
3231 : /* ... and fall through to distribute_restrictinfo_to_rels */
3232 : }
3233 57942 : else if (maybe_outer_join && restrictinfo->can_join)
3234 : {
3235 : /* we need to set up left_ec/right_ec the hard way */
3236 57234 : initialize_mergeclause_eclasses(root, restrictinfo);
3237 : /* now see if it should go to any outer-join lists */
3238 : Assert(sjinfo != NULL);
3239 57234 : if (bms_is_subset(restrictinfo->left_relids,
3240 28626 : outerjoin_nonnullable) &&
3241 28626 : !bms_overlap(restrictinfo->right_relids,
3242 : outerjoin_nonnullable))
3243 : {
3244 : /* we have outervar = innervar */
3245 27326 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
3246 :
3247 27326 : ojcinfo->rinfo = restrictinfo;
3248 27326 : ojcinfo->sjinfo = sjinfo;
3249 27326 : root->left_join_clauses = lappend(root->left_join_clauses,
3250 : ojcinfo);
3251 27326 : return;
3252 : }
3253 29908 : if (bms_is_subset(restrictinfo->right_relids,
3254 29748 : outerjoin_nonnullable) &&
3255 29748 : !bms_overlap(restrictinfo->left_relids,
3256 : outerjoin_nonnullable))
3257 : {
3258 : /* we have innervar = outervar */
3259 28448 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
3260 :
3261 28448 : ojcinfo->rinfo = restrictinfo;
3262 28448 : ojcinfo->sjinfo = sjinfo;
3263 28448 : root->right_join_clauses = lappend(root->right_join_clauses,
3264 : ojcinfo);
3265 28448 : return;
3266 : }
3267 1460 : if (sjinfo->jointype == JOIN_FULL)
3268 : {
3269 : /* FULL JOIN (above tests cannot match in this case) */
3270 1264 : OuterJoinClauseInfo *ojcinfo = makeNode(OuterJoinClauseInfo);
3271 :
3272 1264 : ojcinfo->rinfo = restrictinfo;
3273 1264 : ojcinfo->sjinfo = sjinfo;
3274 1264 : root->full_join_clauses = lappend(root->full_join_clauses,
3275 : ojcinfo);
3276 1264 : return;
3277 : }
3278 : /* nope, so fall through to distribute_restrictinfo_to_rels */
3279 : }
3280 : else
3281 : {
3282 : /* we still need to set up left_ec/right_ec */
3283 708 : initialize_mergeclause_eclasses(root, restrictinfo);
3284 : }
3285 : }
3286 :
3287 : /* No EC special case applies, so push it into the clause lists */
3288 178404 : distribute_restrictinfo_to_rels(root, restrictinfo);
3289 : }
3290 :
3291 : /*
3292 : * check_redundant_nullability_qual
3293 : * Check to see if the qual is an IS NULL qual that is redundant with
3294 : * a lower JOIN_ANTI join.
3295 : *
3296 : * We want to suppress redundant IS NULL quals, not so much to save cycles
3297 : * as to avoid generating bogus selectivity estimates for them. So if
3298 : * redundancy is detected here, distribute_qual_to_rels() just throws away
3299 : * the qual.
3300 : */
3301 : static bool
3302 494090 : check_redundant_nullability_qual(PlannerInfo *root, Node *clause)
3303 : {
3304 : Var *forced_null_var;
3305 : ListCell *lc;
3306 :
3307 : /* Check for IS NULL, and identify the Var forced to NULL */
3308 494090 : forced_null_var = find_forced_null_var(clause);
3309 494090 : if (forced_null_var == NULL)
3310 491386 : return false;
3311 :
3312 : /*
3313 : * If the Var comes from the nullable side of a lower antijoin, the IS
3314 : * NULL condition is necessarily true. If it's not nulled by anything,
3315 : * there is no point in searching the join_info_list. Otherwise, we need
3316 : * to find out whether the nulling rel is an antijoin.
3317 : */
3318 2704 : if (forced_null_var->varnullingrels == NULL)
3319 1442 : return false;
3320 :
3321 1412 : foreach(lc, root->join_info_list)
3322 : {
3323 1306 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
3324 :
3325 : /*
3326 : * This test will not succeed if sjinfo->ojrelid is zero, which is
3327 : * possible for an antijoin that was converted from a semijoin; but in
3328 : * such a case the Var couldn't have come from its nullable side.
3329 : */
3330 2462 : if (sjinfo->jointype == JOIN_ANTI && sjinfo->ojrelid != 0 &&
3331 1156 : bms_is_member(sjinfo->ojrelid, forced_null_var->varnullingrels))
3332 1156 : return true;
3333 : }
3334 :
3335 106 : return false;
3336 : }
3337 :
3338 : /*
3339 : * add_base_clause_to_rel
3340 : * Add 'restrictinfo' as a baserestrictinfo to the base relation denoted
3341 : * by 'relid'. We offer some simple prechecks to try to determine if the
3342 : * qual is always true, in which case we ignore it rather than add it.
3343 : * If we detect the qual is always false, we replace it with
3344 : * constant-FALSE.
3345 : */
3346 : static void
3347 406134 : add_base_clause_to_rel(PlannerInfo *root, Index relid,
3348 : RestrictInfo *restrictinfo)
3349 : {
3350 406134 : RelOptInfo *rel = find_base_rel(root, relid);
3351 406134 : RangeTblEntry *rte = root->simple_rte_array[relid];
3352 :
3353 : Assert(bms_membership(restrictinfo->required_relids) == BMS_SINGLETON);
3354 :
3355 : /*
3356 : * For inheritance parent tables, we must always record the RestrictInfo
3357 : * in baserestrictinfo as is. If we were to transform or skip adding it,
3358 : * then the original wouldn't be available in apply_child_basequals. Since
3359 : * there are two RangeTblEntries for inheritance parents, one with
3360 : * inh==true and the other with inh==false, we're still able to apply this
3361 : * optimization to the inh==false one. The inh==true one is what
3362 : * apply_child_basequals() sees, whereas the inh==false one is what's used
3363 : * for the scan node in the final plan.
3364 : *
3365 : * We make an exception to this for partitioned tables. For these, we
3366 : * always apply the constant-TRUE and constant-FALSE transformations. A
3367 : * qual which is either of these for a partitioned table must also be that
3368 : * for all of its child partitions.
3369 : */
3370 406134 : if (!rte->inh || rte->relkind == RELKIND_PARTITIONED_TABLE)
3371 : {
3372 : /* Don't add the clause if it is always true */
3373 404134 : if (restriction_is_always_true(root, restrictinfo))
3374 480 : return;
3375 :
3376 : /*
3377 : * Substitute the origin qual with constant-FALSE if it is provably
3378 : * always false.
3379 : *
3380 : * Note that we need to keep the same rinfo_serial, since it is in
3381 : * practice the same condition. We also need to reset the
3382 : * last_rinfo_serial counter, which is essential to ensure that the
3383 : * RestrictInfos for the "same" qual condition get identical serial
3384 : * numbers (see deconstruct_distribute_oj_quals).
3385 : */
3386 403654 : if (restriction_is_always_false(root, restrictinfo))
3387 : {
3388 0 : int save_rinfo_serial = restrictinfo->rinfo_serial;
3389 0 : int save_last_rinfo_serial = root->last_rinfo_serial;
3390 :
3391 0 : restrictinfo = make_restrictinfo(root,
3392 0 : (Expr *) makeBoolConst(false, false),
3393 0 : restrictinfo->is_pushed_down,
3394 0 : restrictinfo->has_clone,
3395 0 : restrictinfo->is_clone,
3396 0 : restrictinfo->pseudoconstant,
3397 : 0, /* security_level */
3398 : restrictinfo->required_relids,
3399 : restrictinfo->incompatible_relids,
3400 : restrictinfo->outer_relids);
3401 0 : restrictinfo->rinfo_serial = save_rinfo_serial;
3402 0 : root->last_rinfo_serial = save_last_rinfo_serial;
3403 : }
3404 : }
3405 :
3406 : /* Add clause to rel's restriction list */
3407 405654 : rel->baserestrictinfo = lappend(rel->baserestrictinfo, restrictinfo);
3408 :
3409 : /* Update security level info */
3410 405654 : rel->baserestrict_min_security = Min(rel->baserestrict_min_security,
3411 : restrictinfo->security_level);
3412 : }
3413 :
3414 : /*
3415 : * restriction_is_always_true
3416 : * Check to see if the RestrictInfo is always true.
3417 : *
3418 : * Currently we only check for NullTest quals and OR clauses that include
3419 : * NullTest quals. We may extend it in the future.
3420 : */
3421 : bool
3422 522568 : restriction_is_always_true(PlannerInfo *root,
3423 : RestrictInfo *restrictinfo)
3424 : {
3425 : /*
3426 : * For a clone clause, we don't have a reliable way to determine if the
3427 : * input expression of a NullTest is non-nullable: nullingrel bits in
3428 : * clone clauses may not reflect reality, so we dare not draw conclusions
3429 : * from clones about whether Vars are guaranteed not-null.
3430 : */
3431 522568 : if (restrictinfo->has_clone || restrictinfo->is_clone)
3432 10720 : return false;
3433 :
3434 : /* Check for NullTest qual */
3435 511848 : if (IsA(restrictinfo->clause, NullTest))
3436 : {
3437 11474 : NullTest *nulltest = (NullTest *) restrictinfo->clause;
3438 :
3439 : /* is this NullTest an IS_NOT_NULL qual? */
3440 11474 : if (nulltest->nulltesttype != IS_NOT_NULL)
3441 3040 : return false;
3442 :
3443 : /*
3444 : * Empty rows can appear NULL in some contexts and NOT NULL in others,
3445 : * so avoid this optimization for row expressions.
3446 : */
3447 8434 : if (nulltest->argisrow)
3448 156 : return false;
3449 :
3450 8278 : return expr_is_nonnullable(root, nulltest->arg, true);
3451 : }
3452 :
3453 : /* If it's an OR, check its sub-clauses */
3454 500374 : if (restriction_is_or_clause(restrictinfo))
3455 : {
3456 : ListCell *lc;
3457 :
3458 : Assert(is_orclause(restrictinfo->orclause));
3459 :
3460 : /*
3461 : * if any of the given OR branches is provably always true then the
3462 : * entire condition is true.
3463 : */
3464 30936 : foreach(lc, ((BoolExpr *) restrictinfo->orclause)->args)
3465 : {
3466 21676 : Node *orarg = (Node *) lfirst(lc);
3467 :
3468 21676 : if (!IsA(orarg, RestrictInfo))
3469 3122 : continue;
3470 :
3471 18554 : if (restriction_is_always_true(root, (RestrictInfo *) orarg))
3472 0 : return true;
3473 : }
3474 : }
3475 :
3476 500374 : return false;
3477 : }
3478 :
3479 : /*
3480 : * restriction_is_always_false
3481 : * Check to see if the RestrictInfo is always false.
3482 : *
3483 : * Currently we only check for NullTest quals and OR clauses that include
3484 : * NullTest quals. We may extend it in the future.
3485 : */
3486 : bool
3487 511342 : restriction_is_always_false(PlannerInfo *root,
3488 : RestrictInfo *restrictinfo)
3489 : {
3490 : /*
3491 : * For a clone clause, we don't have a reliable way to determine if the
3492 : * input expression of a NullTest is non-nullable: nullingrel bits in
3493 : * clone clauses may not reflect reality, so we dare not draw conclusions
3494 : * from clones about whether Vars are guaranteed not-null.
3495 : */
3496 511342 : if (restrictinfo->has_clone || restrictinfo->is_clone)
3497 10720 : return false;
3498 :
3499 : /* Check for NullTest qual */
3500 500622 : if (IsA(restrictinfo->clause, NullTest))
3501 : {
3502 9832 : NullTest *nulltest = (NullTest *) restrictinfo->clause;
3503 :
3504 : /* is this NullTest an IS_NULL qual? */
3505 9832 : if (nulltest->nulltesttype != IS_NULL)
3506 7192 : return false;
3507 :
3508 : /*
3509 : * Empty rows can appear NULL in some contexts and NOT NULL in others,
3510 : * so avoid this optimization for row expressions.
3511 : */
3512 2640 : if (nulltest->argisrow)
3513 120 : return false;
3514 :
3515 2520 : return expr_is_nonnullable(root, nulltest->arg, true);
3516 : }
3517 :
3518 : /* If it's an OR, check its sub-clauses */
3519 490790 : if (restriction_is_or_clause(restrictinfo))
3520 : {
3521 : ListCell *lc;
3522 :
3523 : Assert(is_orclause(restrictinfo->orclause));
3524 :
3525 : /*
3526 : * Currently, when processing OR expressions, we only return true when
3527 : * all of the OR branches are always false. This could perhaps be
3528 : * expanded to remove OR branches that are provably false. This may
3529 : * be a useful thing to do as it could result in the OR being left
3530 : * with a single arg. That's useful as it would allow the OR
3531 : * condition to be replaced with its single argument which may allow
3532 : * use of an index for faster filtering on the remaining condition.
3533 : */
3534 9260 : foreach(lc, ((BoolExpr *) restrictinfo->orclause)->args)
3535 : {
3536 9260 : Node *orarg = (Node *) lfirst(lc);
3537 :
3538 9260 : if (!IsA(orarg, RestrictInfo) ||
3539 7808 : !restriction_is_always_false(root, (RestrictInfo *) orarg))
3540 9260 : return false;
3541 : }
3542 0 : return true;
3543 : }
3544 :
3545 481530 : return false;
3546 : }
3547 :
3548 : /*
3549 : * distribute_restrictinfo_to_rels
3550 : * Push a completed RestrictInfo into the proper restriction or join
3551 : * clause list(s).
3552 : *
3553 : * This is the last step of distribute_qual_to_rels() for ordinary qual
3554 : * clauses. Clauses that are interesting for equivalence-class processing
3555 : * are diverted to the EC machinery, but may ultimately get fed back here.
3556 : */
3557 : void
3558 476502 : distribute_restrictinfo_to_rels(PlannerInfo *root,
3559 : RestrictInfo *restrictinfo)
3560 : {
3561 476502 : Relids relids = restrictinfo->required_relids;
3562 :
3563 476502 : if (!bms_is_empty(relids))
3564 : {
3565 : int relid;
3566 :
3567 476502 : if (bms_get_singleton_member(relids, &relid))
3568 : {
3569 : /*
3570 : * There is only one relation participating in the clause, so it
3571 : * is a restriction clause for that relation.
3572 : */
3573 406134 : add_base_clause_to_rel(root, relid, restrictinfo);
3574 : }
3575 : else
3576 : {
3577 : /*
3578 : * The clause is a join clause, since there is more than one rel
3579 : * in its relid set.
3580 : */
3581 :
3582 : /*
3583 : * Check for hashjoinable operators. (We don't bother setting the
3584 : * hashjoin info except in true join clauses.)
3585 : */
3586 70368 : check_hashjoinable(restrictinfo);
3587 :
3588 : /*
3589 : * Likewise, check if the clause is suitable to be used with a
3590 : * Memoize node to cache inner tuples during a parameterized
3591 : * nested loop.
3592 : */
3593 70368 : check_memoizable(restrictinfo);
3594 :
3595 : /*
3596 : * Add clause to the join lists of all the relevant relations.
3597 : */
3598 70368 : add_join_clause_to_rels(root, restrictinfo, relids);
3599 : }
3600 : }
3601 : else
3602 : {
3603 : /*
3604 : * clause references no rels, and therefore we have no place to attach
3605 : * it. Shouldn't get here if callers are working properly.
3606 : */
3607 0 : elog(ERROR, "cannot cope with variable-free clause");
3608 : }
3609 476502 : }
3610 :
3611 : /*
3612 : * process_implied_equality
3613 : * Create a restrictinfo item that says "item1 op item2", and push it
3614 : * into the appropriate lists. (In practice opno is always a btree
3615 : * equality operator.)
3616 : *
3617 : * "qualscope" is the nominal syntactic level to impute to the restrictinfo.
3618 : * This must contain at least all the rels used in the expressions, but it
3619 : * is used only to set the qual application level when both exprs are
3620 : * variable-free. (Hence, it should usually match the join domain in which
3621 : * the clause applies.) Otherwise the qual is applied at the lowest join
3622 : * level that provides all its variables.
3623 : *
3624 : * "security_level" is the security level to assign to the new restrictinfo.
3625 : *
3626 : * "both_const" indicates whether both items are known pseudo-constant;
3627 : * in this case it is worth applying eval_const_expressions() in case we
3628 : * can produce constant TRUE or constant FALSE. (Otherwise it's not,
3629 : * because the expressions went through eval_const_expressions already.)
3630 : *
3631 : * Returns the generated RestrictInfo, if any. The result will be NULL
3632 : * if both_const is true and we successfully reduced the clause to
3633 : * constant TRUE.
3634 : *
3635 : * Note: this function will copy item1 and item2, but it is caller's
3636 : * responsibility to make sure that the Relids parameters are fresh copies
3637 : * not shared with other uses.
3638 : *
3639 : * Note: we do not do initialize_mergeclause_eclasses() here. It is
3640 : * caller's responsibility that left_ec/right_ec be set as necessary.
3641 : */
3642 : RestrictInfo *
3643 37366 : process_implied_equality(PlannerInfo *root,
3644 : Oid opno,
3645 : Oid collation,
3646 : Expr *item1,
3647 : Expr *item2,
3648 : Relids qualscope,
3649 : Index security_level,
3650 : bool both_const)
3651 : {
3652 : RestrictInfo *restrictinfo;
3653 : Node *clause;
3654 : Relids relids;
3655 37366 : bool pseudoconstant = false;
3656 :
3657 : /*
3658 : * Build the new clause. Copy to ensure it shares no substructure with
3659 : * original (this is necessary in case there are subselects in there...)
3660 : */
3661 37366 : clause = (Node *) make_opclause(opno,
3662 : BOOLOID, /* opresulttype */
3663 : false, /* opretset */
3664 37366 : copyObject(item1),
3665 37366 : copyObject(item2),
3666 : InvalidOid,
3667 : collation);
3668 :
3669 : /* If both constant, try to reduce to a boolean constant. */
3670 37366 : if (both_const)
3671 : {
3672 132 : clause = eval_const_expressions(root, clause);
3673 :
3674 : /* If we produced const TRUE, just drop the clause */
3675 132 : if (clause && IsA(clause, Const))
3676 : {
3677 126 : Const *cclause = (Const *) clause;
3678 :
3679 : Assert(cclause->consttype == BOOLOID);
3680 126 : if (!cclause->constisnull && DatumGetBool(cclause->constvalue))
3681 0 : return NULL;
3682 : }
3683 : }
3684 :
3685 : /*
3686 : * The rest of this is a very cut-down version of distribute_qual_to_rels.
3687 : * We can skip most of the work therein, but there are a couple of special
3688 : * cases we still have to handle.
3689 : *
3690 : * Retrieve all relids mentioned within the possibly-simplified clause.
3691 : */
3692 37366 : relids = pull_varnos(root, clause);
3693 : Assert(bms_is_subset(relids, qualscope));
3694 :
3695 : /*
3696 : * If the clause is variable-free, our normal heuristic for pushing it
3697 : * down to just the mentioned rels doesn't work, because there are none.
3698 : * Apply it as a gating qual at the appropriate level (see comments for
3699 : * get_join_domain_min_rels).
3700 : */
3701 37366 : if (bms_is_empty(relids))
3702 : {
3703 : /* eval at join domain's safe level */
3704 132 : relids = get_join_domain_min_rels(root, qualscope);
3705 : /* mark as gating qual */
3706 132 : pseudoconstant = true;
3707 : /* tell createplan.c to check for gating quals */
3708 132 : root->hasPseudoConstantQuals = true;
3709 : }
3710 :
3711 : /*
3712 : * Build the RestrictInfo node itself.
3713 : */
3714 37366 : restrictinfo = make_restrictinfo(root,
3715 : (Expr *) clause,
3716 : true, /* is_pushed_down */
3717 : false, /* !has_clone */
3718 : false, /* !is_clone */
3719 : pseudoconstant,
3720 : security_level,
3721 : relids,
3722 : NULL, /* incompatible_relids */
3723 : NULL); /* outer_relids */
3724 :
3725 : /*
3726 : * If it's a join clause, add vars used in the clause to targetlists of
3727 : * their relations, so that they will be emitted by the plan nodes that
3728 : * scan those relations (else they won't be available at the join node!).
3729 : *
3730 : * Typically, we'd have already done this when the component expressions
3731 : * were first seen by distribute_qual_to_rels; but it is possible that
3732 : * some of the Vars could have missed having that done because they only
3733 : * appeared in single-relation clauses originally. So do it here for
3734 : * safety.
3735 : *
3736 : * See also rebuild_joinclause_attr_needed, which has to partially repeat
3737 : * this work after removal of an outer join. (Since we will put this
3738 : * clause into the joininfo lists, that function needn't do any extra work
3739 : * to find it.)
3740 : */
3741 37366 : if (bms_membership(relids) == BMS_MULTIPLE)
3742 : {
3743 60 : List *vars = pull_var_clause(clause,
3744 : PVC_RECURSE_AGGREGATES |
3745 : PVC_RECURSE_WINDOWFUNCS |
3746 : PVC_INCLUDE_PLACEHOLDERS);
3747 :
3748 60 : add_vars_to_targetlist(root, vars, relids);
3749 60 : list_free(vars);
3750 : }
3751 :
3752 : /*
3753 : * Check mergejoinability. This will usually succeed, since the op came
3754 : * from an EquivalenceClass; but we could have reduced the original clause
3755 : * to a constant.
3756 : */
3757 37366 : check_mergejoinable(restrictinfo);
3758 :
3759 : /*
3760 : * Note we don't do initialize_mergeclause_eclasses(); the caller can
3761 : * handle that much more cheaply than we can. It's okay to call
3762 : * distribute_restrictinfo_to_rels() before that happens.
3763 : */
3764 :
3765 : /*
3766 : * Push the new clause into all the appropriate restrictinfo lists.
3767 : */
3768 37366 : distribute_restrictinfo_to_rels(root, restrictinfo);
3769 :
3770 37366 : return restrictinfo;
3771 : }
3772 :
3773 : /*
3774 : * build_implied_join_equality --- build a RestrictInfo for a derived equality
3775 : *
3776 : * This overlaps the functionality of process_implied_equality(), but we
3777 : * must not push the RestrictInfo into the joininfo tree.
3778 : *
3779 : * Note: this function will copy item1 and item2, but it is caller's
3780 : * responsibility to make sure that the Relids parameters are fresh copies
3781 : * not shared with other uses.
3782 : *
3783 : * Note: we do not do initialize_mergeclause_eclasses() here. It is
3784 : * caller's responsibility that left_ec/right_ec be set as necessary.
3785 : */
3786 : RestrictInfo *
3787 87344 : build_implied_join_equality(PlannerInfo *root,
3788 : Oid opno,
3789 : Oid collation,
3790 : Expr *item1,
3791 : Expr *item2,
3792 : Relids qualscope,
3793 : Index security_level)
3794 : {
3795 : RestrictInfo *restrictinfo;
3796 : Expr *clause;
3797 :
3798 : /*
3799 : * Build the new clause. Copy to ensure it shares no substructure with
3800 : * original (this is necessary in case there are subselects in there...)
3801 : */
3802 87344 : clause = make_opclause(opno,
3803 : BOOLOID, /* opresulttype */
3804 : false, /* opretset */
3805 87344 : copyObject(item1),
3806 87344 : copyObject(item2),
3807 : InvalidOid,
3808 : collation);
3809 :
3810 : /*
3811 : * Build the RestrictInfo node itself.
3812 : */
3813 87344 : restrictinfo = make_restrictinfo(root,
3814 : clause,
3815 : true, /* is_pushed_down */
3816 : false, /* !has_clone */
3817 : false, /* !is_clone */
3818 : false, /* pseudoconstant */
3819 : security_level, /* security_level */
3820 : qualscope, /* required_relids */
3821 : NULL, /* incompatible_relids */
3822 : NULL); /* outer_relids */
3823 :
3824 : /* Set mergejoinability/hashjoinability flags */
3825 87344 : check_mergejoinable(restrictinfo);
3826 87344 : check_hashjoinable(restrictinfo);
3827 87344 : check_memoizable(restrictinfo);
3828 :
3829 87344 : return restrictinfo;
3830 : }
3831 :
3832 : /*
3833 : * get_join_domain_min_rels
3834 : * Identify the appropriate join level for derived quals belonging
3835 : * to the join domain with the given relids.
3836 : *
3837 : * When we derive a pseudoconstant (Var-free) clause from an EquivalenceClass,
3838 : * we'd ideally apply the clause at the top level of the EC's join domain.
3839 : * However, if there are any outer joins inside that domain that get commuted
3840 : * with joins outside it, that leads to not finding a correct place to apply
3841 : * the clause. Instead, remove any lower outer joins from the relid set,
3842 : * and apply the clause to just the remaining rels. This still results in a
3843 : * correct answer, since if the clause produces FALSE then the LHS of these
3844 : * joins will be empty leading to an empty join result.
3845 : *
3846 : * However, there's no need to remove outer joins if this is the top-level
3847 : * join domain of the query, since then there's nothing else to commute with.
3848 : *
3849 : * Note: it's tempting to use this in distribute_qual_to_rels where it's
3850 : * dealing with pseudoconstant quals; but we can't because the necessary
3851 : * SpecialJoinInfos aren't all formed at that point.
3852 : *
3853 : * The result is always freshly palloc'd; we do not modify domain_relids.
3854 : */
3855 : static Relids
3856 132 : get_join_domain_min_rels(PlannerInfo *root, Relids domain_relids)
3857 : {
3858 132 : Relids result = bms_copy(domain_relids);
3859 : ListCell *lc;
3860 :
3861 : /* Top-level join domain? */
3862 132 : if (bms_equal(result, root->all_query_rels))
3863 66 : return result;
3864 :
3865 : /* Nope, look for lower outer joins that could potentially commute out */
3866 138 : foreach(lc, root->join_info_list)
3867 : {
3868 72 : SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
3869 :
3870 144 : if (sjinfo->jointype == JOIN_LEFT &&
3871 72 : bms_is_member(sjinfo->ojrelid, result))
3872 : {
3873 6 : result = bms_del_member(result, sjinfo->ojrelid);
3874 6 : result = bms_del_members(result, sjinfo->syn_righthand);
3875 : }
3876 : }
3877 66 : return result;
3878 : }
3879 :
3880 :
3881 : /*
3882 : * rebuild_joinclause_attr_needed
3883 : * Put back attr_needed bits for Vars/PHVs needed for join clauses.
3884 : *
3885 : * This is used to rebuild attr_needed/ph_needed sets after removal of a
3886 : * useless outer join. It should match what distribute_qual_to_rels did,
3887 : * except that we call add_vars_to_attr_needed not add_vars_to_targetlist.
3888 : */
3889 : void
3890 12046 : rebuild_joinclause_attr_needed(PlannerInfo *root)
3891 : {
3892 : /*
3893 : * We must examine all join clauses, but there's no value in processing
3894 : * any join clause more than once. So it's slightly annoying that we have
3895 : * to find them via the per-base-relation joininfo lists. Avoid duplicate
3896 : * processing by tracking the rinfo_serial numbers of join clauses we've
3897 : * already seen. (This doesn't work for is_clone clauses, so we must
3898 : * waste effort on them.)
3899 : */
3900 12046 : Bitmapset *seen_serials = NULL;
3901 : Index rti;
3902 :
3903 : /* Scan all baserels for join clauses */
3904 77146 : for (rti = 1; rti < root->simple_rel_array_size; rti++)
3905 : {
3906 65100 : RelOptInfo *brel = root->simple_rel_array[rti];
3907 : ListCell *lc;
3908 :
3909 65100 : if (brel == NULL)
3910 44344 : continue;
3911 20756 : if (brel->reloptkind != RELOPT_BASEREL)
3912 0 : continue;
3913 :
3914 30716 : foreach(lc, brel->joininfo)
3915 : {
3916 9960 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3917 9960 : Relids relids = rinfo->required_relids;
3918 :
3919 9960 : if (!rinfo->is_clone) /* else serial number is not unique */
3920 : {
3921 9864 : if (bms_is_member(rinfo->rinfo_serial, seen_serials))
3922 5286 : continue; /* saw it already */
3923 4578 : seen_serials = bms_add_member(seen_serials,
3924 : rinfo->rinfo_serial);
3925 : }
3926 :
3927 4674 : if (bms_membership(relids) == BMS_MULTIPLE)
3928 : {
3929 4674 : List *vars = pull_var_clause((Node *) rinfo->clause,
3930 : PVC_RECURSE_AGGREGATES |
3931 : PVC_RECURSE_WINDOWFUNCS |
3932 : PVC_INCLUDE_PLACEHOLDERS);
3933 : Relids where_needed;
3934 :
3935 4674 : if (rinfo->is_clone)
3936 96 : where_needed = bms_intersect(relids, root->all_baserels);
3937 : else
3938 4578 : where_needed = relids;
3939 4674 : add_vars_to_attr_needed(root, vars, where_needed);
3940 4674 : list_free(vars);
3941 : }
3942 : }
3943 : }
3944 12046 : }
3945 :
3946 :
3947 : /*
3948 : * match_foreign_keys_to_quals
3949 : * Match foreign-key constraints to equivalence classes and join quals
3950 : *
3951 : * The idea here is to see which query join conditions match equality
3952 : * constraints of a foreign-key relationship. For such join conditions,
3953 : * we can use the FK semantics to make selectivity estimates that are more
3954 : * reliable than estimating from statistics, especially for multiple-column
3955 : * FKs, where the normal assumption of independent conditions tends to fail.
3956 : *
3957 : * In this function we annotate the ForeignKeyOptInfos in root->fkey_list
3958 : * with info about which eclasses and join qual clauses they match, and
3959 : * discard any ForeignKeyOptInfos that are irrelevant for the query.
3960 : */
3961 : void
3962 339204 : match_foreign_keys_to_quals(PlannerInfo *root)
3963 : {
3964 339204 : List *newlist = NIL;
3965 : ListCell *lc;
3966 :
3967 340984 : foreach(lc, root->fkey_list)
3968 : {
3969 1780 : ForeignKeyOptInfo *fkinfo = (ForeignKeyOptInfo *) lfirst(lc);
3970 : RelOptInfo *con_rel;
3971 : RelOptInfo *ref_rel;
3972 : int colno;
3973 :
3974 : /*
3975 : * Either relid might identify a rel that is in the query's rtable but
3976 : * isn't referenced by the jointree, or has been removed by join
3977 : * removal, so that it won't have a RelOptInfo. Hence don't use
3978 : * find_base_rel() here. We can ignore such FKs.
3979 : */
3980 1780 : if (fkinfo->con_relid >= root->simple_rel_array_size ||
3981 1780 : fkinfo->ref_relid >= root->simple_rel_array_size)
3982 0 : continue; /* just paranoia */
3983 1780 : con_rel = root->simple_rel_array[fkinfo->con_relid];
3984 1780 : if (con_rel == NULL)
3985 12 : continue;
3986 1768 : ref_rel = root->simple_rel_array[fkinfo->ref_relid];
3987 1768 : if (ref_rel == NULL)
3988 24 : continue;
3989 :
3990 : /*
3991 : * Ignore FK unless both rels are baserels. This gets rid of FKs that
3992 : * link to inheritance child rels (otherrels).
3993 : */
3994 1744 : if (con_rel->reloptkind != RELOPT_BASEREL ||
3995 1744 : ref_rel->reloptkind != RELOPT_BASEREL)
3996 0 : continue;
3997 :
3998 : /*
3999 : * Scan the columns and try to match them to eclasses and quals.
4000 : *
4001 : * Note: for simple inner joins, any match should be in an eclass.
4002 : * "Loose" quals that syntactically match an FK equality must have
4003 : * been rejected for EC status because they are outer-join quals or
4004 : * similar. We can still consider them to match the FK.
4005 : */
4006 4044 : for (colno = 0; colno < fkinfo->nkeys; colno++)
4007 : {
4008 : EquivalenceClass *ec;
4009 : AttrNumber con_attno,
4010 : ref_attno;
4011 : Oid fpeqop;
4012 : ListCell *lc2;
4013 :
4014 2300 : ec = match_eclasses_to_foreign_key_col(root, fkinfo, colno);
4015 : /* Don't bother looking for loose quals if we got an EC match */
4016 2300 : if (ec != NULL)
4017 : {
4018 342 : fkinfo->nmatched_ec++;
4019 342 : if (ec->ec_has_const)
4020 74 : fkinfo->nconst_ec++;
4021 342 : continue;
4022 : }
4023 :
4024 : /*
4025 : * Scan joininfo list for relevant clauses. Either rel's joininfo
4026 : * list would do equally well; we use con_rel's.
4027 : */
4028 1958 : con_attno = fkinfo->conkey[colno];
4029 1958 : ref_attno = fkinfo->confkey[colno];
4030 1958 : fpeqop = InvalidOid; /* we'll look this up only if needed */
4031 :
4032 5112 : foreach(lc2, con_rel->joininfo)
4033 : {
4034 3154 : RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc2);
4035 3154 : OpExpr *clause = (OpExpr *) rinfo->clause;
4036 : Var *leftvar;
4037 : Var *rightvar;
4038 :
4039 : /* Only binary OpExprs are useful for consideration */
4040 6308 : if (!IsA(clause, OpExpr) ||
4041 3154 : list_length(clause->args) != 2)
4042 0 : continue;
4043 3154 : leftvar = (Var *) get_leftop((Expr *) clause);
4044 3154 : rightvar = (Var *) get_rightop((Expr *) clause);
4045 :
4046 : /* Operands must be Vars, possibly with RelabelType */
4047 3400 : while (leftvar && IsA(leftvar, RelabelType))
4048 246 : leftvar = (Var *) ((RelabelType *) leftvar)->arg;
4049 3154 : if (!(leftvar && IsA(leftvar, Var)))
4050 0 : continue;
4051 3382 : while (rightvar && IsA(rightvar, RelabelType))
4052 228 : rightvar = (Var *) ((RelabelType *) rightvar)->arg;
4053 3154 : if (!(rightvar && IsA(rightvar, Var)))
4054 30 : continue;
4055 :
4056 : /* Now try to match the vars to the current foreign key cols */
4057 3124 : if (fkinfo->ref_relid == leftvar->varno &&
4058 2998 : ref_attno == leftvar->varattno &&
4059 1712 : fkinfo->con_relid == rightvar->varno &&
4060 1712 : con_attno == rightvar->varattno)
4061 : {
4062 : /* Vars match, but is it the right operator? */
4063 1634 : if (clause->opno == fkinfo->conpfeqop[colno])
4064 : {
4065 1634 : fkinfo->rinfos[colno] = lappend(fkinfo->rinfos[colno],
4066 : rinfo);
4067 1634 : fkinfo->nmatched_ri++;
4068 : }
4069 : }
4070 1490 : else if (fkinfo->ref_relid == rightvar->varno &&
4071 90 : ref_attno == rightvar->varattno &&
4072 36 : fkinfo->con_relid == leftvar->varno &&
4073 36 : con_attno == leftvar->varattno)
4074 : {
4075 : /*
4076 : * Reverse match, must check commutator operator. Look it
4077 : * up if we didn't already. (In the worst case we might
4078 : * do multiple lookups here, but that would require an FK
4079 : * equality operator without commutator, which is
4080 : * unlikely.)
4081 : */
4082 36 : if (!OidIsValid(fpeqop))
4083 36 : fpeqop = get_commutator(fkinfo->conpfeqop[colno]);
4084 36 : if (clause->opno == fpeqop)
4085 : {
4086 36 : fkinfo->rinfos[colno] = lappend(fkinfo->rinfos[colno],
4087 : rinfo);
4088 36 : fkinfo->nmatched_ri++;
4089 : }
4090 : }
4091 : }
4092 : /* If we found any matching loose quals, count col as matched */
4093 1958 : if (fkinfo->rinfos[colno])
4094 1670 : fkinfo->nmatched_rcols++;
4095 : }
4096 :
4097 : /*
4098 : * Currently, we drop multicolumn FKs that aren't fully matched to the
4099 : * query. Later we might figure out how to derive some sort of
4100 : * estimate from them, in which case this test should be weakened to
4101 : * "if ((fkinfo->nmatched_ec + fkinfo->nmatched_rcols) > 0)".
4102 : */
4103 1744 : if ((fkinfo->nmatched_ec + fkinfo->nmatched_rcols) == fkinfo->nkeys)
4104 1480 : newlist = lappend(newlist, fkinfo);
4105 : }
4106 : /* Replace fkey_list, thereby discarding any useless entries */
4107 339204 : root->fkey_list = newlist;
4108 339204 : }
4109 :
4110 :
4111 : /*****************************************************************************
4112 : *
4113 : * CHECKS FOR MERGEJOINABLE AND HASHJOINABLE CLAUSES
4114 : *
4115 : *****************************************************************************/
4116 :
4117 : /*
4118 : * check_mergejoinable
4119 : * If the restrictinfo's clause is mergejoinable, set the mergejoin
4120 : * info fields in the restrictinfo.
4121 : *
4122 : * Currently, we support mergejoin for binary opclauses where
4123 : * the operator is a mergejoinable operator. The arguments can be
4124 : * anything --- as long as there are no volatile functions in them.
4125 : */
4126 : static void
4127 677076 : check_mergejoinable(RestrictInfo *restrictinfo)
4128 : {
4129 677076 : Expr *clause = restrictinfo->clause;
4130 : Oid opno;
4131 : Node *leftarg;
4132 :
4133 677076 : if (restrictinfo->pseudoconstant)
4134 10736 : return;
4135 666340 : if (!is_opclause(clause))
4136 82572 : return;
4137 583768 : if (list_length(((OpExpr *) clause)->args) != 2)
4138 24 : return;
4139 :
4140 583744 : opno = ((OpExpr *) clause)->opno;
4141 583744 : leftarg = linitial(((OpExpr *) clause)->args);
4142 :
4143 583744 : if (op_mergejoinable(opno, exprType(leftarg)) &&
4144 499738 : !contain_volatile_functions((Node *) restrictinfo))
4145 499706 : restrictinfo->mergeopfamilies = get_mergejoin_opfamilies(opno);
4146 :
4147 : /*
4148 : * Note: op_mergejoinable is just a hint; if we fail to find the operator
4149 : * in any btree opfamilies, mergeopfamilies remains NIL and so the clause
4150 : * is not treated as mergejoinable.
4151 : */
4152 : }
4153 :
4154 : /*
4155 : * check_hashjoinable
4156 : * If the restrictinfo's clause is hashjoinable, set the hashjoin
4157 : * info fields in the restrictinfo.
4158 : *
4159 : * Currently, we support hashjoin for binary opclauses where
4160 : * the operator is a hashjoinable operator. The arguments can be
4161 : * anything --- as long as there are no volatile functions in them.
4162 : */
4163 : static void
4164 157712 : check_hashjoinable(RestrictInfo *restrictinfo)
4165 : {
4166 157712 : Expr *clause = restrictinfo->clause;
4167 : Oid opno;
4168 : Node *leftarg;
4169 :
4170 157712 : if (restrictinfo->pseudoconstant)
4171 3472 : return;
4172 154240 : if (!is_opclause(clause))
4173 7560 : return;
4174 146680 : if (list_length(((OpExpr *) clause)->args) != 2)
4175 0 : return;
4176 :
4177 146680 : opno = ((OpExpr *) clause)->opno;
4178 146680 : leftarg = linitial(((OpExpr *) clause)->args);
4179 :
4180 146680 : if (op_hashjoinable(opno, exprType(leftarg)) &&
4181 143308 : !contain_volatile_functions((Node *) restrictinfo))
4182 143300 : restrictinfo->hashjoinoperator = opno;
4183 : }
4184 :
4185 : /*
4186 : * check_memoizable
4187 : * If the restrictinfo's clause is suitable to be used for a Memoize node,
4188 : * set the left_hasheqoperator and right_hasheqoperator to the hash equality
4189 : * operator that will be needed during caching.
4190 : */
4191 : static void
4192 157712 : check_memoizable(RestrictInfo *restrictinfo)
4193 : {
4194 : TypeCacheEntry *typentry;
4195 157712 : Expr *clause = restrictinfo->clause;
4196 : Oid lefttype;
4197 : Oid righttype;
4198 :
4199 157712 : if (restrictinfo->pseudoconstant)
4200 3472 : return;
4201 154240 : if (!is_opclause(clause))
4202 7560 : return;
4203 146680 : if (list_length(((OpExpr *) clause)->args) != 2)
4204 0 : return;
4205 :
4206 146680 : lefttype = exprType(linitial(((OpExpr *) clause)->args));
4207 :
4208 146680 : typentry = lookup_type_cache(lefttype, TYPECACHE_HASH_PROC |
4209 : TYPECACHE_EQ_OPR);
4210 :
4211 146680 : if (OidIsValid(typentry->hash_proc) && OidIsValid(typentry->eq_opr))
4212 146272 : restrictinfo->left_hasheqoperator = typentry->eq_opr;
4213 :
4214 146680 : righttype = exprType(lsecond(((OpExpr *) clause)->args));
4215 :
4216 : /*
4217 : * Lookup the right type, unless it's the same as the left type, in which
4218 : * case typentry is already pointing to the required TypeCacheEntry.
4219 : */
4220 146680 : if (lefttype != righttype)
4221 2320 : typentry = lookup_type_cache(righttype, TYPECACHE_HASH_PROC |
4222 : TYPECACHE_EQ_OPR);
4223 :
4224 146680 : if (OidIsValid(typentry->hash_proc) && OidIsValid(typentry->eq_opr))
4225 146068 : restrictinfo->right_hasheqoperator = typentry->eq_opr;
4226 : }
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