Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * prepjointree.c
4 : * Planner preprocessing for subqueries and join tree manipulation.
5 : *
6 : * NOTE: the intended sequence for invoking these operations is
7 : * replace_empty_jointree
8 : * pull_up_sublinks
9 : * preprocess_function_rtes
10 : * pull_up_subqueries
11 : * flatten_simple_union_all
12 : * do expression preprocessing (including flattening JOIN alias vars)
13 : * reduce_outer_joins
14 : * remove_useless_result_rtes
15 : *
16 : *
17 : * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
18 : * Portions Copyright (c) 1994, Regents of the University of California
19 : *
20 : *
21 : * IDENTIFICATION
22 : * src/backend/optimizer/prep/prepjointree.c
23 : *
24 : *-------------------------------------------------------------------------
25 : */
26 : #include "postgres.h"
27 :
28 : #include "catalog/pg_type.h"
29 : #include "funcapi.h"
30 : #include "nodes/makefuncs.h"
31 : #include "nodes/nodeFuncs.h"
32 : #include "optimizer/clauses.h"
33 : #include "optimizer/optimizer.h"
34 : #include "optimizer/placeholder.h"
35 : #include "optimizer/prep.h"
36 : #include "optimizer/subselect.h"
37 : #include "optimizer/tlist.h"
38 : #include "parser/parse_relation.h"
39 : #include "parser/parsetree.h"
40 : #include "rewrite/rewriteManip.h"
41 :
42 :
43 : typedef struct pullup_replace_vars_context
44 : {
45 : PlannerInfo *root;
46 : List *targetlist; /* tlist of subquery being pulled up */
47 : RangeTblEntry *target_rte; /* RTE of subquery */
48 : Relids relids; /* relids within subquery, as numbered after
49 : * pullup (set only if target_rte->lateral) */
50 : bool *outer_hasSubLinks; /* -> outer query's hasSubLinks */
51 : int varno; /* varno of subquery */
52 : bool need_phvs; /* do we need PlaceHolderVars? */
53 : bool wrap_non_vars; /* do we need 'em on *all* non-Vars? */
54 : Node **rv_cache; /* cache for results with PHVs */
55 : } pullup_replace_vars_context;
56 :
57 : typedef struct reduce_outer_joins_state
58 : {
59 : Relids relids; /* base relids within this subtree */
60 : bool contains_outer; /* does subtree contain outer join(s)? */
61 : List *sub_states; /* List of states for subtree components */
62 : } reduce_outer_joins_state;
63 :
64 : static Node *pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
65 : Relids *relids);
66 : static Node *pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
67 : Node **jtlink1, Relids available_rels1,
68 : Node **jtlink2, Relids available_rels2);
69 : static Node *pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
70 : JoinExpr *lowest_outer_join,
71 : JoinExpr *lowest_nulling_outer_join,
72 : AppendRelInfo *containing_appendrel);
73 : static Node *pull_up_simple_subquery(PlannerInfo *root, Node *jtnode,
74 : RangeTblEntry *rte,
75 : JoinExpr *lowest_outer_join,
76 : JoinExpr *lowest_nulling_outer_join,
77 : AppendRelInfo *containing_appendrel);
78 : static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
79 : RangeTblEntry *rte);
80 : static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
81 : int parentRTindex, Query *setOpQuery,
82 : int childRToffset);
83 : static void make_setop_translation_list(Query *query, int newvarno,
84 : AppendRelInfo *appinfo);
85 : static bool is_simple_subquery(PlannerInfo *root, Query *subquery,
86 : RangeTblEntry *rte,
87 : JoinExpr *lowest_outer_join);
88 : static Node *pull_up_simple_values(PlannerInfo *root, Node *jtnode,
89 : RangeTblEntry *rte);
90 : static bool is_simple_values(PlannerInfo *root, RangeTblEntry *rte);
91 : static Node *pull_up_constant_function(PlannerInfo *root, Node *jtnode,
92 : RangeTblEntry *rte,
93 : JoinExpr *lowest_nulling_outer_join,
94 : AppendRelInfo *containing_appendrel);
95 : static bool is_simple_union_all(Query *subquery);
96 : static bool is_simple_union_all_recurse(Node *setOp, Query *setOpQuery,
97 : List *colTypes);
98 : static bool is_safe_append_member(Query *subquery);
99 : static bool jointree_contains_lateral_outer_refs(PlannerInfo *root,
100 : Node *jtnode, bool restricted,
101 : Relids safe_upper_varnos);
102 : static void perform_pullup_replace_vars(PlannerInfo *root,
103 : pullup_replace_vars_context *rvcontext,
104 : JoinExpr *lowest_nulling_outer_join,
105 : AppendRelInfo *containing_appendrel);
106 : static void replace_vars_in_jointree(Node *jtnode,
107 : pullup_replace_vars_context *context,
108 : JoinExpr *lowest_nulling_outer_join);
109 : static Node *pullup_replace_vars(Node *expr,
110 : pullup_replace_vars_context *context);
111 : static Node *pullup_replace_vars_callback(Var *var,
112 : replace_rte_variables_context *context);
113 : static Query *pullup_replace_vars_subquery(Query *query,
114 : pullup_replace_vars_context *context);
115 : static reduce_outer_joins_state *reduce_outer_joins_pass1(Node *jtnode);
116 : static void reduce_outer_joins_pass2(Node *jtnode,
117 : reduce_outer_joins_state *state,
118 : PlannerInfo *root,
119 : Relids nonnullable_rels,
120 : List *nonnullable_vars,
121 : List *forced_null_vars);
122 : static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode);
123 : static int get_result_relid(PlannerInfo *root, Node *jtnode);
124 : static void remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc);
125 : static bool find_dependent_phvs(PlannerInfo *root, int varno);
126 : static bool find_dependent_phvs_in_jointree(PlannerInfo *root,
127 : Node *node, int varno);
128 : static void substitute_phv_relids(Node *node,
129 : int varno, Relids subrelids);
130 : static void fix_append_rel_relids(List *append_rel_list, int varno,
131 : Relids subrelids);
132 : static Node *find_jointree_node_for_rel(Node *jtnode, int relid);
133 :
134 :
135 : /*
136 : * replace_empty_jointree
137 : * If the Query's jointree is empty, replace it with a dummy RTE_RESULT
138 : * relation.
139 : *
140 : * By doing this, we can avoid a bunch of corner cases that formerly existed
141 : * for SELECTs with omitted FROM clauses. An example is that a subquery
142 : * with empty jointree previously could not be pulled up, because that would
143 : * have resulted in an empty relid set, making the subquery not uniquely
144 : * identifiable for join or PlaceHolderVar processing.
145 : *
146 : * Unlike most other functions in this file, this function doesn't recurse;
147 : * we rely on other processing to invoke it on sub-queries at suitable times.
148 : */
149 : void
150 479912 : replace_empty_jointree(Query *parse)
151 : {
152 : RangeTblEntry *rte;
153 : Index rti;
154 : RangeTblRef *rtr;
155 :
156 : /* Nothing to do if jointree is already nonempty */
157 479912 : if (parse->jointree->fromlist != NIL)
158 343906 : return;
159 :
160 : /* We mustn't change it in the top level of a setop tree, either */
161 139430 : if (parse->setOperations)
162 3424 : return;
163 :
164 : /* Create suitable RTE */
165 136006 : rte = makeNode(RangeTblEntry);
166 136006 : rte->rtekind = RTE_RESULT;
167 136006 : rte->eref = makeAlias("*RESULT*", NIL);
168 :
169 : /* Add it to rangetable */
170 136006 : parse->rtable = lappend(parse->rtable, rte);
171 136006 : rti = list_length(parse->rtable);
172 :
173 : /* And jam a reference into the jointree */
174 136006 : rtr = makeNode(RangeTblRef);
175 136006 : rtr->rtindex = rti;
176 136006 : parse->jointree->fromlist = list_make1(rtr);
177 : }
178 :
179 : /*
180 : * pull_up_sublinks
181 : * Attempt to pull up ANY and EXISTS SubLinks to be treated as
182 : * semijoins or anti-semijoins.
183 : *
184 : * A clause "foo op ANY (sub-SELECT)" can be processed by pulling the
185 : * sub-SELECT up to become a rangetable entry and treating the implied
186 : * comparisons as quals of a semijoin. However, this optimization *only*
187 : * works at the top level of WHERE or a JOIN/ON clause, because we cannot
188 : * distinguish whether the ANY ought to return FALSE or NULL in cases
189 : * involving NULL inputs. Also, in an outer join's ON clause we can only
190 : * do this if the sublink is degenerate (ie, references only the nullable
191 : * side of the join). In that case it is legal to push the semijoin
192 : * down into the nullable side of the join. If the sublink references any
193 : * nonnullable-side variables then it would have to be evaluated as part
194 : * of the outer join, which makes things way too complicated.
195 : *
196 : * Under similar conditions, EXISTS and NOT EXISTS clauses can be handled
197 : * by pulling up the sub-SELECT and creating a semijoin or anti-semijoin.
198 : *
199 : * This routine searches for such clauses and does the necessary parsetree
200 : * transformations if any are found.
201 : *
202 : * This routine has to run before preprocess_expression(), so the quals
203 : * clauses are not yet reduced to implicit-AND format, and are not guaranteed
204 : * to be AND/OR-flat either. That means we need to recursively search through
205 : * explicit AND clauses. We stop as soon as we hit a non-AND item.
206 : */
207 : void
208 71736 : pull_up_sublinks(PlannerInfo *root)
209 : {
210 : Node *jtnode;
211 : Relids relids;
212 :
213 : /* Begin recursion through the jointree */
214 71736 : jtnode = pull_up_sublinks_jointree_recurse(root,
215 71736 : (Node *) root->parse->jointree,
216 : &relids);
217 :
218 : /*
219 : * root->parse->jointree must always be a FromExpr, so insert a dummy one
220 : * if we got a bare RangeTblRef or JoinExpr out of the recursion.
221 : */
222 71736 : if (IsA(jtnode, FromExpr))
223 61618 : root->parse->jointree = (FromExpr *) jtnode;
224 : else
225 10118 : root->parse->jointree = makeFromExpr(list_make1(jtnode), NULL);
226 71736 : }
227 :
228 : /*
229 : * Recurse through jointree nodes for pull_up_sublinks()
230 : *
231 : * In addition to returning the possibly-modified jointree node, we return
232 : * a relids set of the contained rels into *relids.
233 : */
234 : static Node *
235 322686 : pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
236 : Relids *relids)
237 : {
238 322686 : if (jtnode == NULL)
239 : {
240 0 : *relids = NULL;
241 : }
242 322686 : else if (IsA(jtnode, RangeTblRef))
243 : {
244 167402 : int varno = ((RangeTblRef *) jtnode)->rtindex;
245 :
246 167402 : *relids = bms_make_singleton(varno);
247 : /* jtnode is returned unmodified */
248 : }
249 155284 : else if (IsA(jtnode, FromExpr))
250 : {
251 71740 : FromExpr *f = (FromExpr *) jtnode;
252 71740 : List *newfromlist = NIL;
253 71740 : Relids frelids = NULL;
254 : FromExpr *newf;
255 : Node *jtlink;
256 : ListCell *l;
257 :
258 : /* First, recurse to process children and collect their relids */
259 144970 : foreach(l, f->fromlist)
260 : {
261 : Node *newchild;
262 : Relids childrelids;
263 :
264 73230 : newchild = pull_up_sublinks_jointree_recurse(root,
265 73230 : lfirst(l),
266 : &childrelids);
267 73230 : newfromlist = lappend(newfromlist, newchild);
268 73230 : frelids = bms_join(frelids, childrelids);
269 : }
270 : /* Build the replacement FromExpr; no quals yet */
271 71740 : newf = makeFromExpr(newfromlist, NULL);
272 : /* Set up a link representing the rebuilt jointree */
273 71740 : jtlink = (Node *) newf;
274 : /* Now process qual --- all children are available for use */
275 71740 : newf->quals = pull_up_sublinks_qual_recurse(root, f->quals,
276 : &jtlink, frelids,
277 : NULL, NULL);
278 :
279 : /*
280 : * Note that the result will be either newf, or a stack of JoinExprs
281 : * with newf at the base. We rely on subsequent optimization steps to
282 : * flatten this and rearrange the joins as needed.
283 : *
284 : * Although we could include the pulled-up subqueries in the returned
285 : * relids, there's no need since upper quals couldn't refer to their
286 : * outputs anyway.
287 : */
288 71740 : *relids = frelids;
289 71740 : jtnode = jtlink;
290 : }
291 83544 : else if (IsA(jtnode, JoinExpr))
292 : {
293 : JoinExpr *j;
294 : Relids leftrelids;
295 : Relids rightrelids;
296 : Node *jtlink;
297 :
298 : /*
299 : * Make a modifiable copy of join node, but don't bother copying its
300 : * subnodes (yet).
301 : */
302 83544 : j = (JoinExpr *) palloc(sizeof(JoinExpr));
303 83544 : memcpy(j, jtnode, sizeof(JoinExpr));
304 83544 : jtlink = (Node *) j;
305 :
306 : /* Recurse to process children and collect their relids */
307 83544 : j->larg = pull_up_sublinks_jointree_recurse(root, j->larg,
308 : &leftrelids);
309 83544 : j->rarg = pull_up_sublinks_jointree_recurse(root, j->rarg,
310 : &rightrelids);
311 :
312 : /*
313 : * Now process qual, showing appropriate child relids as available,
314 : * and attach any pulled-up jointree items at the right place. In the
315 : * inner-join case we put new JoinExprs above the existing one (much
316 : * as for a FromExpr-style join). In outer-join cases the new
317 : * JoinExprs must go into the nullable side of the outer join. The
318 : * point of the available_rels machinations is to ensure that we only
319 : * pull up quals for which that's okay.
320 : *
321 : * We don't expect to see any pre-existing JOIN_SEMI or JOIN_ANTI
322 : * nodes here.
323 : */
324 83544 : switch (j->jointype)
325 : {
326 25614 : case JOIN_INNER:
327 25614 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
328 : &jtlink,
329 : bms_union(leftrelids,
330 : rightrelids),
331 : NULL, NULL);
332 25614 : break;
333 57930 : case JOIN_LEFT:
334 57930 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
335 : &j->rarg,
336 : rightrelids,
337 : NULL, NULL);
338 57930 : break;
339 0 : case JOIN_FULL:
340 : /* can't do anything with full-join quals */
341 0 : break;
342 0 : case JOIN_RIGHT:
343 0 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
344 : &j->larg,
345 : leftrelids,
346 : NULL, NULL);
347 0 : break;
348 0 : default:
349 0 : elog(ERROR, "unrecognized join type: %d",
350 : (int) j->jointype);
351 : break;
352 : }
353 :
354 : /*
355 : * Although we could include the pulled-up subqueries in the returned
356 : * relids, there's no need since upper quals couldn't refer to their
357 : * outputs anyway. But we *do* need to include the join's own rtindex
358 : * because we haven't yet collapsed join alias variables, so upper
359 : * levels would mistakenly think they couldn't use references to this
360 : * join.
361 : */
362 83544 : *relids = bms_join(leftrelids, rightrelids);
363 83544 : if (j->rtindex)
364 83544 : *relids = bms_add_member(*relids, j->rtindex);
365 83544 : jtnode = jtlink;
366 : }
367 : else
368 0 : elog(ERROR, "unrecognized node type: %d",
369 : (int) nodeTag(jtnode));
370 322686 : return jtnode;
371 : }
372 :
373 : /*
374 : * Recurse through top-level qual nodes for pull_up_sublinks()
375 : *
376 : * jtlink1 points to the link in the jointree where any new JoinExprs should
377 : * be inserted if they reference available_rels1 (i.e., available_rels1
378 : * denotes the relations present underneath jtlink1). Optionally, jtlink2 can
379 : * point to a second link where new JoinExprs should be inserted if they
380 : * reference available_rels2 (pass NULL for both those arguments if not used).
381 : * Note that SubLinks referencing both sets of variables cannot be optimized.
382 : * If we find multiple pull-up-able SubLinks, they'll get stacked onto jtlink1
383 : * and/or jtlink2 in the order we encounter them. We rely on subsequent
384 : * optimization to rearrange the stack if appropriate.
385 : *
386 : * Returns the replacement qual node, or NULL if the qual should be removed.
387 : */
388 : static Node *
389 328470 : pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
390 : Node **jtlink1, Relids available_rels1,
391 : Node **jtlink2, Relids available_rels2)
392 : {
393 328470 : if (node == NULL)
394 7406 : return NULL;
395 321064 : if (IsA(node, SubLink))
396 : {
397 1004 : SubLink *sublink = (SubLink *) node;
398 : JoinExpr *j;
399 : Relids child_rels;
400 :
401 : /* Is it a convertible ANY or EXISTS clause? */
402 1004 : if (sublink->subLinkType == ANY_SUBLINK)
403 : {
404 752 : if ((j = convert_ANY_sublink_to_join(root, sublink,
405 : available_rels1)) != NULL)
406 : {
407 : /* Yes; insert the new join node into the join tree */
408 680 : j->larg = *jtlink1;
409 680 : *jtlink1 = (Node *) j;
410 : /* Recursively process pulled-up jointree nodes */
411 680 : j->rarg = pull_up_sublinks_jointree_recurse(root,
412 : j->rarg,
413 : &child_rels);
414 :
415 : /*
416 : * Now recursively process the pulled-up quals. Any inserted
417 : * joins can get stacked onto either j->larg or j->rarg,
418 : * depending on which rels they reference.
419 : */
420 680 : j->quals = pull_up_sublinks_qual_recurse(root,
421 : j->quals,
422 : &j->larg,
423 : available_rels1,
424 : &j->rarg,
425 : child_rels);
426 : /* Return NULL representing constant TRUE */
427 680 : return NULL;
428 : }
429 72 : if (available_rels2 != NULL &&
430 0 : (j = convert_ANY_sublink_to_join(root, sublink,
431 : available_rels2)) != NULL)
432 : {
433 : /* Yes; insert the new join node into the join tree */
434 0 : j->larg = *jtlink2;
435 0 : *jtlink2 = (Node *) j;
436 : /* Recursively process pulled-up jointree nodes */
437 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
438 : j->rarg,
439 : &child_rels);
440 :
441 : /*
442 : * Now recursively process the pulled-up quals. Any inserted
443 : * joins can get stacked onto either j->larg or j->rarg,
444 : * depending on which rels they reference.
445 : */
446 0 : j->quals = pull_up_sublinks_qual_recurse(root,
447 : j->quals,
448 : &j->larg,
449 : available_rels2,
450 : &j->rarg,
451 : child_rels);
452 : /* Return NULL representing constant TRUE */
453 0 : return NULL;
454 : }
455 : }
456 252 : else if (sublink->subLinkType == EXISTS_SUBLINK)
457 : {
458 224 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, false,
459 : available_rels1)) != NULL)
460 : {
461 : /* Yes; insert the new join node into the join tree */
462 170 : j->larg = *jtlink1;
463 170 : *jtlink1 = (Node *) j;
464 : /* Recursively process pulled-up jointree nodes */
465 170 : j->rarg = pull_up_sublinks_jointree_recurse(root,
466 : j->rarg,
467 : &child_rels);
468 :
469 : /*
470 : * Now recursively process the pulled-up quals. Any inserted
471 : * joins can get stacked onto either j->larg or j->rarg,
472 : * depending on which rels they reference.
473 : */
474 170 : j->quals = pull_up_sublinks_qual_recurse(root,
475 : j->quals,
476 : &j->larg,
477 : available_rels1,
478 : &j->rarg,
479 : child_rels);
480 : /* Return NULL representing constant TRUE */
481 170 : return NULL;
482 : }
483 54 : if (available_rels2 != NULL &&
484 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, false,
485 : available_rels2)) != NULL)
486 : {
487 : /* Yes; insert the new join node into the join tree */
488 0 : j->larg = *jtlink2;
489 0 : *jtlink2 = (Node *) j;
490 : /* Recursively process pulled-up jointree nodes */
491 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
492 : j->rarg,
493 : &child_rels);
494 :
495 : /*
496 : * Now recursively process the pulled-up quals. Any inserted
497 : * joins can get stacked onto either j->larg or j->rarg,
498 : * depending on which rels they reference.
499 : */
500 0 : j->quals = pull_up_sublinks_qual_recurse(root,
501 : j->quals,
502 : &j->larg,
503 : available_rels2,
504 : &j->rarg,
505 : child_rels);
506 : /* Return NULL representing constant TRUE */
507 0 : return NULL;
508 : }
509 : }
510 : /* Else return it unmodified */
511 154 : return node;
512 : }
513 320060 : if (is_notclause(node))
514 : {
515 : /* If the immediate argument of NOT is EXISTS, try to convert */
516 12490 : SubLink *sublink = (SubLink *) get_notclausearg((Expr *) node);
517 : JoinExpr *j;
518 : Relids child_rels;
519 :
520 12490 : if (sublink && IsA(sublink, SubLink))
521 : {
522 9858 : if (sublink->subLinkType == EXISTS_SUBLINK)
523 : {
524 9802 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, true,
525 : available_rels1)) != NULL)
526 : {
527 : /* Yes; insert the new join node into the join tree */
528 9782 : j->larg = *jtlink1;
529 9782 : *jtlink1 = (Node *) j;
530 : /* Recursively process pulled-up jointree nodes */
531 9782 : j->rarg = pull_up_sublinks_jointree_recurse(root,
532 : j->rarg,
533 : &child_rels);
534 :
535 : /*
536 : * Now recursively process the pulled-up quals. Because
537 : * we are underneath a NOT, we can't pull up sublinks that
538 : * reference the left-hand stuff, but it's still okay to
539 : * pull up sublinks referencing j->rarg.
540 : */
541 9782 : j->quals = pull_up_sublinks_qual_recurse(root,
542 : j->quals,
543 : &j->rarg,
544 : child_rels,
545 : NULL, NULL);
546 : /* Return NULL representing constant TRUE */
547 9782 : return NULL;
548 : }
549 20 : if (available_rels2 != NULL &&
550 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, true,
551 : available_rels2)) != NULL)
552 : {
553 : /* Yes; insert the new join node into the join tree */
554 0 : j->larg = *jtlink2;
555 0 : *jtlink2 = (Node *) j;
556 : /* Recursively process pulled-up jointree nodes */
557 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
558 : j->rarg,
559 : &child_rels);
560 :
561 : /*
562 : * Now recursively process the pulled-up quals. Because
563 : * we are underneath a NOT, we can't pull up sublinks that
564 : * reference the left-hand stuff, but it's still okay to
565 : * pull up sublinks referencing j->rarg.
566 : */
567 0 : j->quals = pull_up_sublinks_qual_recurse(root,
568 : j->quals,
569 : &j->rarg,
570 : child_rels,
571 : NULL, NULL);
572 : /* Return NULL representing constant TRUE */
573 0 : return NULL;
574 : }
575 : }
576 : }
577 : /* Else return it unmodified */
578 2708 : return node;
579 : }
580 307570 : if (is_andclause(node))
581 : {
582 : /* Recurse into AND clause */
583 64760 : List *newclauses = NIL;
584 : ListCell *l;
585 :
586 227314 : foreach(l, ((BoolExpr *) node)->args)
587 : {
588 162554 : Node *oldclause = (Node *) lfirst(l);
589 : Node *newclause;
590 :
591 162554 : newclause = pull_up_sublinks_qual_recurse(root,
592 : oldclause,
593 : jtlink1,
594 : available_rels1,
595 : jtlink2,
596 : available_rels2);
597 162554 : if (newclause)
598 160356 : newclauses = lappend(newclauses, newclause);
599 : }
600 : /* We might have got back fewer clauses than we started with */
601 64760 : if (newclauses == NIL)
602 482 : return NULL;
603 64278 : else if (list_length(newclauses) == 1)
604 614 : return (Node *) linitial(newclauses);
605 : else
606 63664 : return (Node *) make_andclause(newclauses);
607 : }
608 : /* Stop if not an AND */
609 242810 : return node;
610 : }
611 :
612 : /*
613 : * preprocess_function_rtes
614 : * Constant-simplify any FUNCTION RTEs in the FROM clause, and then
615 : * attempt to "inline" any that are set-returning functions.
616 : *
617 : * If an RTE_FUNCTION rtable entry invokes a set-returning function that
618 : * contains just a simple SELECT, we can convert the rtable entry to an
619 : * RTE_SUBQUERY entry exposing the SELECT directly. This is especially
620 : * useful if the subquery can then be "pulled up" for further optimization,
621 : * but we do it even if not, to reduce executor overhead.
622 : *
623 : * This has to be done before we have started to do any optimization of
624 : * subqueries, else any such steps wouldn't get applied to subqueries
625 : * obtained via inlining. However, we do it after pull_up_sublinks
626 : * so that we can inline any functions used in SubLink subselects.
627 : *
628 : * The reason for applying const-simplification at this stage is that
629 : * (a) we'd need to do it anyway to inline a SRF, and (b) by doing it now,
630 : * we can be sure that pull_up_constant_function() will see constants
631 : * if there are constants to be seen. This approach also guarantees
632 : * that every FUNCTION RTE has been const-simplified, allowing planner.c's
633 : * preprocess_expression() to skip doing it again.
634 : *
635 : * Like most of the planner, this feels free to scribble on its input data
636 : * structure.
637 : */
638 : void
639 469960 : preprocess_function_rtes(PlannerInfo *root)
640 : {
641 : ListCell *rt;
642 :
643 1307738 : foreach(rt, root->parse->rtable)
644 : {
645 837782 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
646 :
647 837782 : if (rte->rtekind == RTE_FUNCTION)
648 : {
649 : Query *funcquery;
650 :
651 : /* Apply const-simplification */
652 66078 : rte->functions = (List *)
653 66078 : eval_const_expressions(root, (Node *) rte->functions);
654 :
655 : /* Check safety of expansion, and expand if possible */
656 66078 : funcquery = inline_set_returning_function(root, rte);
657 66074 : if (funcquery)
658 : {
659 : /* Successful expansion, convert the RTE to a subquery */
660 92 : rte->rtekind = RTE_SUBQUERY;
661 92 : rte->subquery = funcquery;
662 92 : rte->security_barrier = false;
663 : /* Clear fields that should not be set in a subquery RTE */
664 92 : rte->functions = NIL;
665 92 : rte->funcordinality = false;
666 : }
667 : }
668 : }
669 469956 : }
670 :
671 : /*
672 : * pull_up_subqueries
673 : * Look for subqueries in the rangetable that can be pulled up into
674 : * the parent query. If the subquery has no special features like
675 : * grouping/aggregation then we can merge it into the parent's jointree.
676 : * Also, subqueries that are simple UNION ALL structures can be
677 : * converted into "append relations".
678 : */
679 : void
680 469956 : pull_up_subqueries(PlannerInfo *root)
681 : {
682 : /* Top level of jointree must always be a FromExpr */
683 : Assert(IsA(root->parse->jointree, FromExpr));
684 : /* Recursion starts with no containing join nor appendrel */
685 939908 : root->parse->jointree = (FromExpr *)
686 469956 : pull_up_subqueries_recurse(root, (Node *) root->parse->jointree,
687 : NULL, NULL, NULL);
688 : /* We should still have a FromExpr */
689 : Assert(IsA(root->parse->jointree, FromExpr));
690 469952 : }
691 :
692 : /*
693 : * pull_up_subqueries_recurse
694 : * Recursive guts of pull_up_subqueries.
695 : *
696 : * This recursively processes the jointree and returns a modified jointree.
697 : *
698 : * If this jointree node is within either side of an outer join, then
699 : * lowest_outer_join references the lowest such JoinExpr node; otherwise
700 : * it is NULL. We use this to constrain the effects of LATERAL subqueries.
701 : *
702 : * If this jointree node is within the nullable side of an outer join, then
703 : * lowest_nulling_outer_join references the lowest such JoinExpr node;
704 : * otherwise it is NULL. This forces use of the PlaceHolderVar mechanism for
705 : * references to non-nullable targetlist items, but only for references above
706 : * that join.
707 : *
708 : * If we are looking at a member subquery of an append relation,
709 : * containing_appendrel describes that relation; else it is NULL.
710 : * This forces use of the PlaceHolderVar mechanism for all non-Var targetlist
711 : * items, and puts some additional restrictions on what can be pulled up.
712 : *
713 : * A tricky aspect of this code is that if we pull up a subquery we have
714 : * to replace Vars that reference the subquery's outputs throughout the
715 : * parent query, including quals attached to jointree nodes above the one
716 : * we are currently processing! We handle this by being careful to maintain
717 : * validity of the jointree structure while recursing, in the following sense:
718 : * whenever we recurse, all qual expressions in the tree must be reachable
719 : * from the top level, in case the recursive call needs to modify them.
720 : *
721 : * Notice also that we can't turn pullup_replace_vars loose on the whole
722 : * jointree, because it'd return a mutated copy of the tree; we have to
723 : * invoke it just on the quals, instead. This behavior is what makes it
724 : * reasonable to pass lowest_outer_join and lowest_nulling_outer_join as
725 : * pointers rather than some more-indirect way of identifying the lowest
726 : * OJs. Likewise, we don't replace append_rel_list members but only their
727 : * substructure, so the containing_appendrel reference is safe to use.
728 : */
729 : static Node *
730 1232600 : pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
731 : JoinExpr *lowest_outer_join,
732 : JoinExpr *lowest_nulling_outer_join,
733 : AppendRelInfo *containing_appendrel)
734 : {
735 : Assert(jtnode != NULL);
736 1232600 : if (IsA(jtnode, RangeTblRef))
737 : {
738 623832 : int varno = ((RangeTblRef *) jtnode)->rtindex;
739 623832 : RangeTblEntry *rte = rt_fetch(varno, root->parse->rtable);
740 :
741 : /*
742 : * Is this a subquery RTE, and if so, is the subquery simple enough to
743 : * pull up?
744 : *
745 : * If we are looking at an append-relation member, we can't pull it up
746 : * unless is_safe_append_member says so.
747 : */
748 661652 : if (rte->rtekind == RTE_SUBQUERY &&
749 70492 : is_simple_subquery(root, rte->subquery, rte, lowest_outer_join) &&
750 1916 : (containing_appendrel == NULL ||
751 1916 : is_safe_append_member(rte->subquery)))
752 32370 : return pull_up_simple_subquery(root, jtnode, rte,
753 : lowest_outer_join,
754 : lowest_nulling_outer_join,
755 : containing_appendrel);
756 :
757 : /*
758 : * Alternatively, is it a simple UNION ALL subquery? If so, flatten
759 : * into an "append relation".
760 : *
761 : * It's safe to do this regardless of whether this query is itself an
762 : * appendrel member. (If you're thinking we should try to flatten the
763 : * two levels of appendrel together, you're right; but we handle that
764 : * in set_append_rel_pathlist, not here.)
765 : */
766 596912 : if (rte->rtekind == RTE_SUBQUERY &&
767 5450 : is_simple_union_all(rte->subquery))
768 802 : return pull_up_simple_union_all(root, jtnode, rte);
769 :
770 : /*
771 : * Or perhaps it's a simple VALUES RTE?
772 : *
773 : * We don't allow VALUES pullup below an outer join nor into an
774 : * appendrel (such cases are impossible anyway at the moment).
775 : */
776 590660 : if (rte->rtekind == RTE_VALUES &&
777 5428 : lowest_outer_join == NULL &&
778 5428 : containing_appendrel == NULL &&
779 5428 : is_simple_values(root, rte))
780 692 : return pull_up_simple_values(root, jtnode, rte);
781 :
782 : /*
783 : * Or perhaps it's a FUNCTION RTE that we could inline?
784 : */
785 589968 : if (rte->rtekind == RTE_FUNCTION)
786 65982 : return pull_up_constant_function(root, jtnode, rte,
787 : lowest_nulling_outer_join,
788 : containing_appendrel);
789 :
790 : /* Otherwise, do nothing at this node. */
791 : }
792 608768 : else if (IsA(jtnode, FromExpr))
793 : {
794 480078 : FromExpr *f = (FromExpr *) jtnode;
795 : ListCell *l;
796 :
797 : Assert(containing_appendrel == NULL);
798 : /* Recursively transform all the child nodes */
799 983086 : foreach(l, f->fromlist)
800 : {
801 503012 : lfirst(l) = pull_up_subqueries_recurse(root, lfirst(l),
802 : lowest_outer_join,
803 : lowest_nulling_outer_join,
804 : NULL);
805 : }
806 : }
807 128690 : else if (IsA(jtnode, JoinExpr))
808 : {
809 128690 : JoinExpr *j = (JoinExpr *) jtnode;
810 :
811 : Assert(containing_appendrel == NULL);
812 : /* Recurse, being careful to tell myself when inside outer join */
813 128690 : switch (j->jointype)
814 : {
815 39054 : case JOIN_INNER:
816 39054 : j->larg = pull_up_subqueries_recurse(root, j->larg,
817 : lowest_outer_join,
818 : lowest_nulling_outer_join,
819 : NULL);
820 39054 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
821 : lowest_outer_join,
822 : lowest_nulling_outer_join,
823 : NULL);
824 39054 : break;
825 88846 : case JOIN_LEFT:
826 : case JOIN_SEMI:
827 : case JOIN_ANTI:
828 88846 : j->larg = pull_up_subqueries_recurse(root, j->larg,
829 : j,
830 : lowest_nulling_outer_join,
831 : NULL);
832 88846 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
833 : j,
834 : j,
835 : NULL);
836 88846 : break;
837 602 : case JOIN_FULL:
838 602 : j->larg = pull_up_subqueries_recurse(root, j->larg,
839 : j,
840 : j,
841 : NULL);
842 602 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
843 : j,
844 : j,
845 : NULL);
846 602 : break;
847 188 : case JOIN_RIGHT:
848 188 : j->larg = pull_up_subqueries_recurse(root, j->larg,
849 : j,
850 : j,
851 : NULL);
852 188 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
853 : j,
854 : lowest_nulling_outer_join,
855 : NULL);
856 188 : break;
857 0 : default:
858 0 : elog(ERROR, "unrecognized join type: %d",
859 : (int) j->jointype);
860 : break;
861 : }
862 : }
863 : else
864 0 : elog(ERROR, "unrecognized node type: %d",
865 : (int) nodeTag(jtnode));
866 1132750 : return jtnode;
867 : }
868 :
869 : /*
870 : * pull_up_simple_subquery
871 : * Attempt to pull up a single simple subquery.
872 : *
873 : * jtnode is a RangeTblRef that has been tentatively identified as a simple
874 : * subquery by pull_up_subqueries. We return the replacement jointree node,
875 : * or jtnode itself if we determine that the subquery can't be pulled up
876 : * after all.
877 : *
878 : * rte is the RangeTblEntry referenced by jtnode. Remaining parameters are
879 : * as for pull_up_subqueries_recurse.
880 : */
881 : static Node *
882 32370 : pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
883 : JoinExpr *lowest_outer_join,
884 : JoinExpr *lowest_nulling_outer_join,
885 : AppendRelInfo *containing_appendrel)
886 : {
887 32370 : Query *parse = root->parse;
888 32370 : int varno = ((RangeTblRef *) jtnode)->rtindex;
889 : Query *subquery;
890 : PlannerInfo *subroot;
891 : int rtoffset;
892 : pullup_replace_vars_context rvcontext;
893 : ListCell *lc;
894 :
895 : /*
896 : * Make a modifiable copy of the subquery to hack on, so that the RTE will
897 : * be left unchanged in case we decide below that we can't pull it up
898 : * after all.
899 : */
900 32370 : subquery = copyObject(rte->subquery);
901 :
902 : /*
903 : * Create a PlannerInfo data structure for this subquery.
904 : *
905 : * NOTE: the next few steps should match the first processing in
906 : * subquery_planner(). Can we refactor to avoid code duplication, or
907 : * would that just make things uglier?
908 : */
909 32370 : subroot = makeNode(PlannerInfo);
910 32370 : subroot->parse = subquery;
911 32370 : subroot->glob = root->glob;
912 32370 : subroot->query_level = root->query_level;
913 32370 : subroot->parent_root = root->parent_root;
914 32370 : subroot->plan_params = NIL;
915 32370 : subroot->outer_params = NULL;
916 32370 : subroot->planner_cxt = CurrentMemoryContext;
917 32370 : subroot->init_plans = NIL;
918 32370 : subroot->cte_plan_ids = NIL;
919 32370 : subroot->multiexpr_params = NIL;
920 32370 : subroot->eq_classes = NIL;
921 32370 : subroot->ec_merging_done = false;
922 32370 : subroot->all_result_relids = NULL;
923 32370 : subroot->leaf_result_relids = NULL;
924 32370 : subroot->append_rel_list = NIL;
925 32370 : subroot->row_identity_vars = NIL;
926 32370 : subroot->rowMarks = NIL;
927 32370 : memset(subroot->upper_rels, 0, sizeof(subroot->upper_rels));
928 32370 : memset(subroot->upper_targets, 0, sizeof(subroot->upper_targets));
929 32370 : subroot->processed_tlist = NIL;
930 32370 : subroot->update_colnos = NIL;
931 32370 : subroot->grouping_map = NULL;
932 32370 : subroot->minmax_aggs = NIL;
933 32370 : subroot->qual_security_level = 0;
934 32370 : subroot->hasRecursion = false;
935 32370 : subroot->wt_param_id = -1;
936 32370 : subroot->non_recursive_path = NULL;
937 :
938 : /* No CTEs to worry about */
939 : Assert(subquery->cteList == NIL);
940 :
941 : /*
942 : * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
943 : * that we don't need so many special cases to deal with that situation.
944 : */
945 32370 : replace_empty_jointree(subquery);
946 :
947 : /*
948 : * Pull up any SubLinks within the subquery's quals, so that we don't
949 : * leave unoptimized SubLinks behind.
950 : */
951 32370 : if (subquery->hasSubLinks)
952 12648 : pull_up_sublinks(subroot);
953 :
954 : /*
955 : * Similarly, preprocess its function RTEs to inline any set-returning
956 : * functions in its rangetable.
957 : */
958 32370 : preprocess_function_rtes(subroot);
959 :
960 : /*
961 : * Recursively pull up the subquery's subqueries, so that
962 : * pull_up_subqueries' processing is complete for its jointree and
963 : * rangetable.
964 : *
965 : * Note: it's okay that the subquery's recursion starts with NULL for
966 : * containing-join info, even if we are within an outer join in the upper
967 : * query; the lower query starts with a clean slate for outer-join
968 : * semantics. Likewise, we needn't pass down appendrel state.
969 : */
970 32370 : pull_up_subqueries(subroot);
971 :
972 : /*
973 : * Now we must recheck whether the subquery is still simple enough to pull
974 : * up. If not, abandon processing it.
975 : *
976 : * We don't really need to recheck all the conditions involved, but it's
977 : * easier just to keep this "if" looking the same as the one in
978 : * pull_up_subqueries_recurse.
979 : */
980 32370 : if (is_simple_subquery(root, subquery, rte, lowest_outer_join) &&
981 1614 : (containing_appendrel == NULL || is_safe_append_member(subquery)))
982 : {
983 : /* good to go */
984 : }
985 : else
986 : {
987 : /*
988 : * Give up, return unmodified RangeTblRef.
989 : *
990 : * Note: The work we just did will be redone when the subquery gets
991 : * planned on its own. Perhaps we could avoid that by storing the
992 : * modified subquery back into the rangetable, but I'm not gonna risk
993 : * it now.
994 : */
995 36 : return jtnode;
996 : }
997 :
998 : /*
999 : * We must flatten any join alias Vars in the subquery's targetlist,
1000 : * because pulling up the subquery's subqueries might have changed their
1001 : * expansions into arbitrary expressions, which could affect
1002 : * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
1003 : * are needed for tlist entries. (Likely it'd be better to do
1004 : * flatten_join_alias_vars on the whole query tree at some earlier stage,
1005 : * maybe even in the rewriter; but for now let's just fix this case here.)
1006 : */
1007 32334 : subquery->targetList = (List *)
1008 32334 : flatten_join_alias_vars(subroot->parse, (Node *) subquery->targetList);
1009 :
1010 : /*
1011 : * Adjust level-0 varnos in subquery so that we can append its rangetable
1012 : * to upper query's. We have to fix the subquery's append_rel_list as
1013 : * well.
1014 : */
1015 32334 : rtoffset = list_length(parse->rtable);
1016 32334 : OffsetVarNodes((Node *) subquery, rtoffset, 0);
1017 32334 : OffsetVarNodes((Node *) subroot->append_rel_list, rtoffset, 0);
1018 :
1019 : /*
1020 : * Upper-level vars in subquery are now one level closer to their parent
1021 : * than before.
1022 : */
1023 32334 : IncrementVarSublevelsUp((Node *) subquery, -1, 1);
1024 32334 : IncrementVarSublevelsUp((Node *) subroot->append_rel_list, -1, 1);
1025 :
1026 : /*
1027 : * The subquery's targetlist items are now in the appropriate form to
1028 : * insert into the top query, except that we may need to wrap them in
1029 : * PlaceHolderVars. Set up required context data for pullup_replace_vars.
1030 : */
1031 32334 : rvcontext.root = root;
1032 32334 : rvcontext.targetlist = subquery->targetList;
1033 32334 : rvcontext.target_rte = rte;
1034 32334 : if (rte->lateral)
1035 380 : rvcontext.relids = get_relids_in_jointree((Node *) subquery->jointree,
1036 : true);
1037 : else /* won't need relids */
1038 31954 : rvcontext.relids = NULL;
1039 32334 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1040 32334 : rvcontext.varno = varno;
1041 : /* these flags will be set below, if needed */
1042 32334 : rvcontext.need_phvs = false;
1043 32334 : rvcontext.wrap_non_vars = false;
1044 : /* initialize cache array with indexes 0 .. length(tlist) */
1045 32334 : rvcontext.rv_cache = palloc0((list_length(subquery->targetList) + 1) *
1046 : sizeof(Node *));
1047 :
1048 : /*
1049 : * If we are under an outer join then non-nullable items and lateral
1050 : * references may have to be turned into PlaceHolderVars.
1051 : */
1052 32334 : if (lowest_nulling_outer_join != NULL)
1053 1332 : rvcontext.need_phvs = true;
1054 :
1055 : /*
1056 : * If we are dealing with an appendrel member then anything that's not a
1057 : * simple Var has to be turned into a PlaceHolderVar. We force this to
1058 : * ensure that what we pull up doesn't get merged into a surrounding
1059 : * expression during later processing and then fail to match the
1060 : * expression actually available from the appendrel.
1061 : */
1062 32334 : if (containing_appendrel != NULL)
1063 : {
1064 1578 : rvcontext.need_phvs = true;
1065 1578 : rvcontext.wrap_non_vars = true;
1066 : }
1067 :
1068 : /*
1069 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1070 : * anything that's not a simple Var. Again, this ensures that expressions
1071 : * retain their separate identity so that they will match grouping set
1072 : * columns when appropriate. (It'd be sufficient to wrap values used in
1073 : * grouping set columns, and do so only in non-aggregated portions of the
1074 : * tlist and havingQual, but that would require a lot of infrastructure
1075 : * that pullup_replace_vars hasn't currently got.)
1076 : */
1077 32334 : if (parse->groupingSets)
1078 : {
1079 160 : rvcontext.need_phvs = true;
1080 160 : rvcontext.wrap_non_vars = true;
1081 : }
1082 :
1083 : /*
1084 : * Replace all of the top query's references to the subquery's outputs
1085 : * with copies of the adjusted subtlist items, being careful not to
1086 : * replace any of the jointree structure.
1087 : */
1088 32334 : perform_pullup_replace_vars(root, &rvcontext,
1089 : lowest_nulling_outer_join,
1090 : containing_appendrel);
1091 :
1092 : /*
1093 : * If the subquery had a LATERAL marker, propagate that to any of its
1094 : * child RTEs that could possibly now contain lateral cross-references.
1095 : * The children might or might not contain any actual lateral
1096 : * cross-references, but we have to mark the pulled-up child RTEs so that
1097 : * later planner stages will check for such.
1098 : */
1099 32330 : if (rte->lateral)
1100 : {
1101 964 : foreach(lc, subquery->rtable)
1102 : {
1103 584 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(lc);
1104 :
1105 584 : switch (child_rte->rtekind)
1106 : {
1107 256 : case RTE_RELATION:
1108 256 : if (child_rte->tablesample)
1109 12 : child_rte->lateral = true;
1110 256 : break;
1111 132 : case RTE_SUBQUERY:
1112 : case RTE_FUNCTION:
1113 : case RTE_VALUES:
1114 : case RTE_TABLEFUNC:
1115 132 : child_rte->lateral = true;
1116 132 : break;
1117 196 : case RTE_JOIN:
1118 : case RTE_CTE:
1119 : case RTE_NAMEDTUPLESTORE:
1120 : case RTE_RESULT:
1121 : /* these can't contain any lateral references */
1122 196 : break;
1123 : }
1124 584 : }
1125 : }
1126 :
1127 : /*
1128 : * Now append the adjusted rtable entries to upper query. (We hold off
1129 : * until after fixing the upper rtable entries; no point in running that
1130 : * code on the subquery ones too.)
1131 : */
1132 32330 : parse->rtable = list_concat(parse->rtable, subquery->rtable);
1133 :
1134 : /*
1135 : * Pull up any FOR UPDATE/SHARE markers, too. (OffsetVarNodes already
1136 : * adjusted the marker rtindexes, so just concat the lists.)
1137 : */
1138 32330 : parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
1139 :
1140 : /*
1141 : * We also have to fix the relid sets of any PlaceHolderVar nodes in the
1142 : * parent query. (This could perhaps be done by pullup_replace_vars(),
1143 : * but it seems cleaner to use two passes.) Note in particular that any
1144 : * PlaceHolderVar nodes just created by pullup_replace_vars() will be
1145 : * adjusted, so having created them with the subquery's varno is correct.
1146 : *
1147 : * Likewise, relids appearing in AppendRelInfo nodes have to be fixed. We
1148 : * already checked that this won't require introducing multiple subrelids
1149 : * into the single-slot AppendRelInfo structs.
1150 : */
1151 32330 : if (parse->hasSubLinks || root->glob->lastPHId != 0 ||
1152 25566 : root->append_rel_list)
1153 : {
1154 : Relids subrelids;
1155 :
1156 7870 : subrelids = get_relids_in_jointree((Node *) subquery->jointree, false);
1157 7870 : substitute_phv_relids((Node *) parse, varno, subrelids);
1158 7870 : fix_append_rel_relids(root->append_rel_list, varno, subrelids);
1159 : }
1160 :
1161 : /*
1162 : * And now add subquery's AppendRelInfos to our list.
1163 : */
1164 64660 : root->append_rel_list = list_concat(root->append_rel_list,
1165 32330 : subroot->append_rel_list);
1166 :
1167 : /*
1168 : * We don't have to do the equivalent bookkeeping for outer-join info,
1169 : * because that hasn't been set up yet. placeholder_list likewise.
1170 : */
1171 : Assert(root->join_info_list == NIL);
1172 : Assert(subroot->join_info_list == NIL);
1173 : Assert(root->placeholder_list == NIL);
1174 : Assert(subroot->placeholder_list == NIL);
1175 :
1176 : /*
1177 : * We no longer need the RTE's copy of the subquery's query tree. Getting
1178 : * rid of it saves nothing in particular so far as this level of query is
1179 : * concerned; but if this query level is in turn pulled up into a parent,
1180 : * we'd waste cycles copying the now-unused query tree.
1181 : */
1182 32330 : rte->subquery = NULL;
1183 :
1184 : /*
1185 : * Miscellaneous housekeeping.
1186 : *
1187 : * Although replace_rte_variables() faithfully updated parse->hasSubLinks
1188 : * if it copied any SubLinks out of the subquery's targetlist, we still
1189 : * could have SubLinks added to the query in the expressions of FUNCTION
1190 : * and VALUES RTEs copied up from the subquery. So it's necessary to copy
1191 : * subquery->hasSubLinks anyway. Perhaps this can be improved someday.
1192 : */
1193 32330 : parse->hasSubLinks |= subquery->hasSubLinks;
1194 :
1195 : /* If subquery had any RLS conditions, now main query does too */
1196 32330 : parse->hasRowSecurity |= subquery->hasRowSecurity;
1197 :
1198 : /*
1199 : * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
1200 : * hasTargetSRFs, so no work needed on those flags
1201 : */
1202 :
1203 : /*
1204 : * Return the adjusted subquery jointree to replace the RangeTblRef entry
1205 : * in parent's jointree; or, if the FromExpr is degenerate, just return
1206 : * its single member.
1207 : */
1208 : Assert(IsA(subquery->jointree, FromExpr));
1209 : Assert(subquery->jointree->fromlist != NIL);
1210 57882 : if (subquery->jointree->quals == NULL &&
1211 25552 : list_length(subquery->jointree->fromlist) == 1)
1212 25408 : return (Node *) linitial(subquery->jointree->fromlist);
1213 :
1214 6922 : return (Node *) subquery->jointree;
1215 : }
1216 :
1217 : /*
1218 : * pull_up_simple_union_all
1219 : * Pull up a single simple UNION ALL subquery.
1220 : *
1221 : * jtnode is a RangeTblRef that has been identified as a simple UNION ALL
1222 : * subquery by pull_up_subqueries. We pull up the leaf subqueries and
1223 : * build an "append relation" for the union set. The result value is just
1224 : * jtnode, since we don't actually need to change the query jointree.
1225 : */
1226 : static Node *
1227 802 : pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1228 : {
1229 802 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1230 802 : Query *subquery = rte->subquery;
1231 802 : int rtoffset = list_length(root->parse->rtable);
1232 : List *rtable;
1233 :
1234 : /*
1235 : * Make a modifiable copy of the subquery's rtable, so we can adjust
1236 : * upper-level Vars in it. There are no such Vars in the setOperations
1237 : * tree proper, so fixing the rtable should be sufficient.
1238 : */
1239 802 : rtable = copyObject(subquery->rtable);
1240 :
1241 : /*
1242 : * Upper-level vars in subquery are now one level closer to their parent
1243 : * than before. We don't have to worry about offsetting varnos, though,
1244 : * because the UNION leaf queries can't cross-reference each other.
1245 : */
1246 802 : IncrementVarSublevelsUp_rtable(rtable, -1, 1);
1247 :
1248 : /*
1249 : * If the UNION ALL subquery had a LATERAL marker, propagate that to all
1250 : * its children. The individual children might or might not contain any
1251 : * actual lateral cross-references, but we have to mark the pulled-up
1252 : * child RTEs so that later planner stages will check for such.
1253 : */
1254 802 : if (rte->lateral)
1255 : {
1256 : ListCell *rt;
1257 :
1258 120 : foreach(rt, rtable)
1259 : {
1260 80 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
1261 :
1262 : Assert(child_rte->rtekind == RTE_SUBQUERY);
1263 80 : child_rte->lateral = true;
1264 : }
1265 : }
1266 :
1267 : /*
1268 : * Append child RTEs to parent rtable.
1269 : */
1270 802 : root->parse->rtable = list_concat(root->parse->rtable, rtable);
1271 :
1272 : /*
1273 : * Recursively scan the subquery's setOperations tree and add
1274 : * AppendRelInfo nodes for leaf subqueries to the parent's
1275 : * append_rel_list. Also apply pull_up_subqueries to the leaf subqueries.
1276 : */
1277 : Assert(subquery->setOperations);
1278 802 : pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
1279 : rtoffset);
1280 :
1281 : /*
1282 : * Mark the parent as an append relation.
1283 : */
1284 802 : rte->inh = true;
1285 :
1286 802 : return jtnode;
1287 : }
1288 :
1289 : /*
1290 : * pull_up_union_leaf_queries -- recursive guts of pull_up_simple_union_all
1291 : *
1292 : * Build an AppendRelInfo for each leaf query in the setop tree, and then
1293 : * apply pull_up_subqueries to the leaf query.
1294 : *
1295 : * Note that setOpQuery is the Query containing the setOp node, whose tlist
1296 : * contains references to all the setop output columns. When called from
1297 : * pull_up_simple_union_all, this is *not* the same as root->parse, which is
1298 : * the parent Query we are pulling up into.
1299 : *
1300 : * parentRTindex is the appendrel parent's index in root->parse->rtable.
1301 : *
1302 : * The child RTEs have already been copied to the parent. childRToffset
1303 : * tells us where in the parent's range table they were copied. When called
1304 : * from flatten_simple_union_all, childRToffset is 0 since the child RTEs
1305 : * were already in root->parse->rtable and no RT index adjustment is needed.
1306 : */
1307 : static void
1308 3522 : pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
1309 : Query *setOpQuery, int childRToffset)
1310 : {
1311 3522 : if (IsA(setOp, RangeTblRef))
1312 : {
1313 2252 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1314 : int childRTindex;
1315 : AppendRelInfo *appinfo;
1316 :
1317 : /*
1318 : * Calculate the index in the parent's range table
1319 : */
1320 2252 : childRTindex = childRToffset + rtr->rtindex;
1321 :
1322 : /*
1323 : * Build a suitable AppendRelInfo, and attach to parent's list.
1324 : */
1325 2252 : appinfo = makeNode(AppendRelInfo);
1326 2252 : appinfo->parent_relid = parentRTindex;
1327 2252 : appinfo->child_relid = childRTindex;
1328 2252 : appinfo->parent_reltype = InvalidOid;
1329 2252 : appinfo->child_reltype = InvalidOid;
1330 2252 : make_setop_translation_list(setOpQuery, childRTindex, appinfo);
1331 2252 : appinfo->parent_reloid = InvalidOid;
1332 2252 : root->append_rel_list = lappend(root->append_rel_list, appinfo);
1333 :
1334 : /*
1335 : * Recursively apply pull_up_subqueries to the new child RTE. (We
1336 : * must build the AppendRelInfo first, because this will modify it.)
1337 : * Note that we can pass NULL for containing-join info even if we're
1338 : * actually under an outer join, because the child's expressions
1339 : * aren't going to propagate up to the join. Also, we ignore the
1340 : * possibility that pull_up_subqueries_recurse() returns a different
1341 : * jointree node than what we pass it; if it does, the important thing
1342 : * is that it replaced the child relid in the AppendRelInfo node.
1343 : */
1344 2252 : rtr = makeNode(RangeTblRef);
1345 2252 : rtr->rtindex = childRTindex;
1346 2252 : (void) pull_up_subqueries_recurse(root, (Node *) rtr,
1347 : NULL, NULL, appinfo);
1348 : }
1349 1270 : else if (IsA(setOp, SetOperationStmt))
1350 : {
1351 1270 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1352 :
1353 : /* Recurse to reach leaf queries */
1354 1270 : pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
1355 : childRToffset);
1356 1270 : pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
1357 : childRToffset);
1358 : }
1359 : else
1360 : {
1361 0 : elog(ERROR, "unrecognized node type: %d",
1362 : (int) nodeTag(setOp));
1363 : }
1364 3522 : }
1365 :
1366 : /*
1367 : * make_setop_translation_list
1368 : * Build the list of translations from parent Vars to child Vars for
1369 : * a UNION ALL member. (At this point it's just a simple list of
1370 : * referencing Vars, but if we succeed in pulling up the member
1371 : * subquery, the Vars will get replaced by pulled-up expressions.)
1372 : * Also create the rather trivial reverse-translation array.
1373 : */
1374 : static void
1375 2252 : make_setop_translation_list(Query *query, int newvarno,
1376 : AppendRelInfo *appinfo)
1377 : {
1378 2252 : List *vars = NIL;
1379 : AttrNumber *pcolnos;
1380 : ListCell *l;
1381 :
1382 : /* Initialize reverse-translation array with all entries zero */
1383 : /* (entries for resjunk columns will stay that way) */
1384 2252 : appinfo->num_child_cols = list_length(query->targetList);
1385 2252 : appinfo->parent_colnos = pcolnos =
1386 2252 : (AttrNumber *) palloc0(appinfo->num_child_cols * sizeof(AttrNumber));
1387 :
1388 7446 : foreach(l, query->targetList)
1389 : {
1390 5194 : TargetEntry *tle = (TargetEntry *) lfirst(l);
1391 :
1392 5194 : if (tle->resjunk)
1393 0 : continue;
1394 :
1395 5194 : vars = lappend(vars, makeVarFromTargetEntry(newvarno, tle));
1396 5194 : pcolnos[tle->resno - 1] = tle->resno;
1397 : }
1398 :
1399 2252 : appinfo->translated_vars = vars;
1400 2252 : }
1401 :
1402 : /*
1403 : * is_simple_subquery
1404 : * Check a subquery in the range table to see if it's simple enough
1405 : * to pull up into the parent query.
1406 : *
1407 : * rte is the RTE_SUBQUERY RangeTblEntry that contained the subquery.
1408 : * (Note subquery is not necessarily equal to rte->subquery; it could be a
1409 : * processed copy of that.)
1410 : * lowest_outer_join is the lowest outer join above the subquery, or NULL.
1411 : */
1412 : static bool
1413 70190 : is_simple_subquery(PlannerInfo *root, Query *subquery, RangeTblEntry *rte,
1414 : JoinExpr *lowest_outer_join)
1415 : {
1416 : /*
1417 : * Let's just make sure it's a valid subselect ...
1418 : */
1419 70190 : if (!IsA(subquery, Query) ||
1420 70190 : subquery->commandType != CMD_SELECT)
1421 0 : elog(ERROR, "subquery is bogus");
1422 :
1423 : /*
1424 : * Can't currently pull up a query with setops (unless it's simple UNION
1425 : * ALL, which is handled by a different code path). Maybe after querytree
1426 : * redesign...
1427 : */
1428 70190 : if (subquery->setOperations)
1429 1568 : return false;
1430 :
1431 : /*
1432 : * Can't pull up a subquery involving grouping, aggregation, SRFs,
1433 : * sorting, limiting, or WITH. (XXX WITH could possibly be allowed later)
1434 : *
1435 : * We also don't pull up a subquery that has explicit FOR UPDATE/SHARE
1436 : * clauses, because pullup would cause the locking to occur semantically
1437 : * higher than it should. Implicit FOR UPDATE/SHARE is okay because in
1438 : * that case the locking was originally declared in the upper query
1439 : * anyway.
1440 : */
1441 68622 : if (subquery->hasAggs ||
1442 68076 : subquery->hasWindowFuncs ||
1443 67980 : subquery->hasTargetSRFs ||
1444 66864 : subquery->groupClause ||
1445 66828 : subquery->groupingSets ||
1446 66828 : subquery->havingQual ||
1447 66828 : subquery->sortClause ||
1448 65956 : subquery->distinctClause ||
1449 65796 : subquery->limitOffset ||
1450 65612 : subquery->limitCount ||
1451 65440 : subquery->hasForUpdate ||
1452 65428 : subquery->cteList)
1453 3278 : return false;
1454 :
1455 : /*
1456 : * Don't pull up if the RTE represents a security-barrier view; we
1457 : * couldn't prevent information leakage once the RTE's Vars are scattered
1458 : * about in the upper query.
1459 : */
1460 65344 : if (rte->security_barrier)
1461 188 : return false;
1462 :
1463 : /*
1464 : * If the subquery is LATERAL, check for pullup restrictions from that.
1465 : */
1466 65156 : if (rte->lateral)
1467 : {
1468 : bool restricted;
1469 : Relids safe_upper_varnos;
1470 :
1471 : /*
1472 : * The subquery's WHERE and JOIN/ON quals mustn't contain any lateral
1473 : * references to rels outside a higher outer join (including the case
1474 : * where the outer join is within the subquery itself). In such a
1475 : * case, pulling up would result in a situation where we need to
1476 : * postpone quals from below an outer join to above it, which is
1477 : * probably completely wrong and in any case is a complication that
1478 : * doesn't seem worth addressing at the moment.
1479 : */
1480 804 : if (lowest_outer_join != NULL)
1481 : {
1482 264 : restricted = true;
1483 264 : safe_upper_varnos = get_relids_in_jointree((Node *) lowest_outer_join,
1484 : true);
1485 : }
1486 : else
1487 : {
1488 540 : restricted = false;
1489 540 : safe_upper_varnos = NULL; /* doesn't matter */
1490 : }
1491 :
1492 804 : if (jointree_contains_lateral_outer_refs(root,
1493 804 : (Node *) subquery->jointree,
1494 : restricted, safe_upper_varnos))
1495 8 : return false;
1496 :
1497 : /*
1498 : * If there's an outer join above the LATERAL subquery, also disallow
1499 : * pullup if the subquery's targetlist has any references to rels
1500 : * outside the outer join, since these might get pulled into quals
1501 : * above the subquery (but in or below the outer join) and then lead
1502 : * to qual-postponement issues similar to the case checked for above.
1503 : * (We wouldn't need to prevent pullup if no such references appear in
1504 : * outer-query quals, but we don't have enough info here to check
1505 : * that. Also, maybe this restriction could be removed if we forced
1506 : * such refs to be wrapped in PlaceHolderVars, even when they're below
1507 : * the nearest outer join? But it's a pretty hokey usage, so not
1508 : * clear this is worth sweating over.)
1509 : */
1510 796 : if (lowest_outer_join != NULL)
1511 : {
1512 264 : Relids lvarnos = pull_varnos_of_level(root,
1513 264 : (Node *) subquery->targetList,
1514 : 1);
1515 :
1516 264 : if (!bms_is_subset(lvarnos, safe_upper_varnos))
1517 8 : return false;
1518 : }
1519 : }
1520 :
1521 : /*
1522 : * Don't pull up a subquery that has any volatile functions in its
1523 : * targetlist. Otherwise we might introduce multiple evaluations of these
1524 : * functions, if they get copied to multiple places in the upper query,
1525 : * leading to surprising results. (Note: the PlaceHolderVar mechanism
1526 : * doesn't quite guarantee single evaluation; else we could pull up anyway
1527 : * and just wrap such items in PlaceHolderVars ...)
1528 : */
1529 65140 : if (contain_volatile_functions((Node *) subquery->targetList))
1530 98 : return false;
1531 :
1532 65042 : return true;
1533 : }
1534 :
1535 : /*
1536 : * pull_up_simple_values
1537 : * Pull up a single simple VALUES RTE.
1538 : *
1539 : * jtnode is a RangeTblRef that has been identified as a simple VALUES RTE
1540 : * by pull_up_subqueries. We always return a RangeTblRef representing a
1541 : * RESULT RTE to replace it (all failure cases should have been detected by
1542 : * is_simple_values()). Actually, what we return is just jtnode, because
1543 : * we replace the VALUES RTE in the rangetable with the RESULT RTE.
1544 : *
1545 : * rte is the RangeTblEntry referenced by jtnode. Because of the limited
1546 : * possible usage of VALUES RTEs, we do not need the remaining parameters
1547 : * of pull_up_subqueries_recurse.
1548 : */
1549 : static Node *
1550 692 : pull_up_simple_values(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1551 : {
1552 692 : Query *parse = root->parse;
1553 692 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1554 : List *values_list;
1555 : List *tlist;
1556 : AttrNumber attrno;
1557 : pullup_replace_vars_context rvcontext;
1558 : ListCell *lc;
1559 :
1560 : Assert(rte->rtekind == RTE_VALUES);
1561 : Assert(list_length(rte->values_lists) == 1);
1562 :
1563 : /*
1564 : * Need a modifiable copy of the VALUES list to hack on, just in case it's
1565 : * multiply referenced.
1566 : */
1567 692 : values_list = copyObject(linitial(rte->values_lists));
1568 :
1569 : /*
1570 : * The VALUES RTE can't contain any Vars of level zero, let alone any that
1571 : * are join aliases, so no need to flatten join alias Vars.
1572 : */
1573 : Assert(!contain_vars_of_level((Node *) values_list, 0));
1574 :
1575 : /*
1576 : * Set up required context data for pullup_replace_vars. In particular,
1577 : * we have to make the VALUES list look like a subquery targetlist.
1578 : */
1579 692 : tlist = NIL;
1580 692 : attrno = 1;
1581 1682 : foreach(lc, values_list)
1582 : {
1583 990 : tlist = lappend(tlist,
1584 990 : makeTargetEntry((Expr *) lfirst(lc),
1585 : attrno,
1586 : NULL,
1587 : false));
1588 990 : attrno++;
1589 : }
1590 692 : rvcontext.root = root;
1591 692 : rvcontext.targetlist = tlist;
1592 692 : rvcontext.target_rte = rte;
1593 692 : rvcontext.relids = NULL;
1594 692 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1595 692 : rvcontext.varno = varno;
1596 692 : rvcontext.need_phvs = false;
1597 692 : rvcontext.wrap_non_vars = false;
1598 : /* initialize cache array with indexes 0 .. length(tlist) */
1599 692 : rvcontext.rv_cache = palloc0((list_length(tlist) + 1) *
1600 : sizeof(Node *));
1601 :
1602 : /*
1603 : * Replace all of the top query's references to the RTE's outputs with
1604 : * copies of the adjusted VALUES expressions, being careful not to replace
1605 : * any of the jointree structure. We can assume there's no outer joins or
1606 : * appendrels in the dummy Query that surrounds a VALUES RTE.
1607 : */
1608 692 : perform_pullup_replace_vars(root, &rvcontext, NULL, NULL);
1609 :
1610 : /*
1611 : * There should be no appendrels to fix, nor any outer joins and hence no
1612 : * PlaceHolderVars.
1613 : */
1614 : Assert(root->append_rel_list == NIL);
1615 : Assert(root->join_info_list == NIL);
1616 : Assert(root->placeholder_list == NIL);
1617 :
1618 : /*
1619 : * Replace the VALUES RTE with a RESULT RTE. The VALUES RTE is the only
1620 : * rtable entry in the current query level, so this is easy.
1621 : */
1622 : Assert(list_length(parse->rtable) == 1);
1623 :
1624 : /* Create suitable RTE */
1625 692 : rte = makeNode(RangeTblEntry);
1626 692 : rte->rtekind = RTE_RESULT;
1627 692 : rte->eref = makeAlias("*RESULT*", NIL);
1628 :
1629 : /* Replace rangetable */
1630 692 : parse->rtable = list_make1(rte);
1631 :
1632 : /* We could manufacture a new RangeTblRef, but the one we have is fine */
1633 : Assert(varno == 1);
1634 :
1635 692 : return jtnode;
1636 : }
1637 :
1638 : /*
1639 : * is_simple_values
1640 : * Check a VALUES RTE in the range table to see if it's simple enough
1641 : * to pull up into the parent query.
1642 : *
1643 : * rte is the RTE_VALUES RangeTblEntry to check.
1644 : */
1645 : static bool
1646 5428 : is_simple_values(PlannerInfo *root, RangeTblEntry *rte)
1647 : {
1648 : Assert(rte->rtekind == RTE_VALUES);
1649 :
1650 : /*
1651 : * There must be exactly one VALUES list, else it's not semantically
1652 : * correct to replace the VALUES RTE with a RESULT RTE, nor would we have
1653 : * a unique set of expressions to substitute into the parent query.
1654 : */
1655 5428 : if (list_length(rte->values_lists) != 1)
1656 4736 : return false;
1657 :
1658 : /*
1659 : * Because VALUES can't appear under an outer join (or at least, we won't
1660 : * try to pull it up if it does), we need not worry about LATERAL, nor
1661 : * about validity of PHVs for the VALUES' outputs.
1662 : */
1663 :
1664 : /*
1665 : * Don't pull up a VALUES that contains any set-returning or volatile
1666 : * functions. The considerations here are basically identical to the
1667 : * restrictions on a pull-able subquery's targetlist.
1668 : */
1669 1384 : if (expression_returns_set((Node *) rte->values_lists) ||
1670 692 : contain_volatile_functions((Node *) rte->values_lists))
1671 0 : return false;
1672 :
1673 : /*
1674 : * Do not pull up a VALUES that's not the only RTE in its parent query.
1675 : * This is actually the only case that the parser will generate at the
1676 : * moment, and assuming this is true greatly simplifies
1677 : * pull_up_simple_values().
1678 : */
1679 692 : if (list_length(root->parse->rtable) != 1 ||
1680 692 : rte != (RangeTblEntry *) linitial(root->parse->rtable))
1681 0 : return false;
1682 :
1683 692 : return true;
1684 : }
1685 :
1686 : /*
1687 : * pull_up_constant_function
1688 : * Pull up an RTE_FUNCTION expression that was simplified to a constant.
1689 : *
1690 : * jtnode is a RangeTblRef that has been identified as a FUNCTION RTE by
1691 : * pull_up_subqueries. If its expression is just a Const, hoist that value
1692 : * up into the parent query, and replace the RTE_FUNCTION with RTE_RESULT.
1693 : *
1694 : * In principle we could pull up any immutable expression, but we don't.
1695 : * That might result in multiple evaluations of the expression, which could
1696 : * be costly if it's not just a Const. Also, the main value of this is
1697 : * to let the constant participate in further const-folding, and of course
1698 : * that won't happen for a non-Const.
1699 : *
1700 : * The pulled-up value might need to be wrapped in a PlaceHolderVar if the
1701 : * RTE is below an outer join or is part of an appendrel; the extra
1702 : * parameters show whether that's needed.
1703 : */
1704 : static Node *
1705 65982 : pull_up_constant_function(PlannerInfo *root, Node *jtnode,
1706 : RangeTblEntry *rte,
1707 : JoinExpr *lowest_nulling_outer_join,
1708 : AppendRelInfo *containing_appendrel)
1709 : {
1710 65982 : Query *parse = root->parse;
1711 : RangeTblFunction *rtf;
1712 : TypeFuncClass functypclass;
1713 : Oid funcrettype;
1714 : TupleDesc tupdesc;
1715 : pullup_replace_vars_context rvcontext;
1716 :
1717 : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
1718 65982 : if (rte->funcordinality)
1719 7626 : return jtnode;
1720 :
1721 : /* Fail if RTE isn't a single, simple Const expr */
1722 58356 : if (list_length(rte->functions) != 1)
1723 52 : return jtnode;
1724 58304 : rtf = linitial_node(RangeTblFunction, rte->functions);
1725 58304 : if (!IsA(rtf->funcexpr, Const))
1726 58064 : return jtnode;
1727 :
1728 : /*
1729 : * If the function's result is not a scalar, we punt. In principle we
1730 : * could break the composite constant value apart into per-column
1731 : * constants, but for now it seems not worth the work.
1732 : */
1733 240 : if (rtf->funccolcount != 1)
1734 16 : return jtnode; /* definitely composite */
1735 :
1736 224 : functypclass = get_expr_result_type(rtf->funcexpr,
1737 : &funcrettype,
1738 : &tupdesc);
1739 224 : if (functypclass != TYPEFUNC_SCALAR)
1740 8 : return jtnode; /* must be a one-column composite type */
1741 :
1742 : /* Create context for applying pullup_replace_vars */
1743 216 : rvcontext.root = root;
1744 216 : rvcontext.targetlist = list_make1(makeTargetEntry((Expr *) rtf->funcexpr,
1745 : 1, /* resno */
1746 : NULL, /* resname */
1747 : false)); /* resjunk */
1748 216 : rvcontext.target_rte = rte;
1749 :
1750 : /*
1751 : * Since this function was reduced to a Const, it doesn't contain any
1752 : * lateral references, even if it's marked as LATERAL. This means we
1753 : * don't need to fill relids.
1754 : */
1755 216 : rvcontext.relids = NULL;
1756 :
1757 216 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1758 216 : rvcontext.varno = ((RangeTblRef *) jtnode)->rtindex;
1759 : /* these flags will be set below, if needed */
1760 216 : rvcontext.need_phvs = false;
1761 216 : rvcontext.wrap_non_vars = false;
1762 : /* initialize cache array with indexes 0 .. length(tlist) */
1763 216 : rvcontext.rv_cache = palloc0((list_length(rvcontext.targetlist) + 1) *
1764 : sizeof(Node *));
1765 :
1766 : /*
1767 : * If we are under an outer join then non-nullable items and lateral
1768 : * references may have to be turned into PlaceHolderVars.
1769 : */
1770 216 : if (lowest_nulling_outer_join != NULL)
1771 12 : rvcontext.need_phvs = true;
1772 :
1773 : /*
1774 : * If we are dealing with an appendrel member then anything that's not a
1775 : * simple Var has to be turned into a PlaceHolderVar. (See comments in
1776 : * pull_up_simple_subquery().)
1777 : */
1778 216 : if (containing_appendrel != NULL)
1779 : {
1780 0 : rvcontext.need_phvs = true;
1781 0 : rvcontext.wrap_non_vars = true;
1782 : }
1783 :
1784 : /*
1785 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1786 : * anything that's not a simple Var.
1787 : */
1788 216 : if (parse->groupingSets)
1789 : {
1790 0 : rvcontext.need_phvs = true;
1791 0 : rvcontext.wrap_non_vars = true;
1792 : }
1793 :
1794 : /*
1795 : * Replace all of the top query's references to the RTE's output with
1796 : * copies of the funcexpr, being careful not to replace any of the
1797 : * jointree structure.
1798 : */
1799 216 : perform_pullup_replace_vars(root, &rvcontext,
1800 : lowest_nulling_outer_join,
1801 : containing_appendrel);
1802 :
1803 : /*
1804 : * We don't need to bother with changing PlaceHolderVars in the parent
1805 : * query. Their references to the RT index are still good for now, and
1806 : * will get removed later if we're able to drop the RTE_RESULT.
1807 : */
1808 :
1809 : /*
1810 : * Convert the RTE to be RTE_RESULT type, signifying that we don't need to
1811 : * scan it anymore, and zero out RTE_FUNCTION-specific fields. Also make
1812 : * sure the RTE is not marked LATERAL, since elsewhere we don't expect
1813 : * RTE_RESULTs to be LATERAL.
1814 : */
1815 216 : rte->rtekind = RTE_RESULT;
1816 216 : rte->functions = NIL;
1817 216 : rte->lateral = false;
1818 :
1819 : /*
1820 : * We can reuse the RangeTblRef node.
1821 : */
1822 216 : return jtnode;
1823 : }
1824 :
1825 : /*
1826 : * is_simple_union_all
1827 : * Check a subquery to see if it's a simple UNION ALL.
1828 : *
1829 : * We require all the setops to be UNION ALL (no mixing) and there can't be
1830 : * any datatype coercions involved, ie, all the leaf queries must emit the
1831 : * same datatypes.
1832 : */
1833 : static bool
1834 5450 : is_simple_union_all(Query *subquery)
1835 : {
1836 : SetOperationStmt *topop;
1837 :
1838 : /* Let's just make sure it's a valid subselect ... */
1839 5450 : if (!IsA(subquery, Query) ||
1840 5450 : subquery->commandType != CMD_SELECT)
1841 0 : elog(ERROR, "subquery is bogus");
1842 :
1843 : /* Is it a set-operation query at all? */
1844 5450 : topop = castNode(SetOperationStmt, subquery->setOperations);
1845 5450 : if (!topop)
1846 3882 : return false;
1847 :
1848 : /* Can't handle ORDER BY, LIMIT/OFFSET, locking, or WITH */
1849 1568 : if (subquery->sortClause ||
1850 1540 : subquery->limitOffset ||
1851 1540 : subquery->limitCount ||
1852 1540 : subquery->rowMarks ||
1853 1540 : subquery->cteList)
1854 56 : return false;
1855 :
1856 : /* Recursively check the tree of set operations */
1857 1512 : return is_simple_union_all_recurse((Node *) topop, subquery,
1858 : topop->colTypes);
1859 : }
1860 :
1861 : static bool
1862 7800 : is_simple_union_all_recurse(Node *setOp, Query *setOpQuery, List *colTypes)
1863 : {
1864 7800 : if (IsA(setOp, RangeTblRef))
1865 : {
1866 2808 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1867 2808 : RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
1868 2808 : Query *subquery = rte->subquery;
1869 :
1870 : Assert(subquery != NULL);
1871 :
1872 : /* Leaf nodes are OK if they match the toplevel column types */
1873 : /* We don't have to compare typmods or collations here */
1874 2808 : return tlist_same_datatypes(subquery->targetList, colTypes, true);
1875 : }
1876 4992 : else if (IsA(setOp, SetOperationStmt))
1877 : {
1878 4992 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1879 :
1880 : /* Must be UNION ALL */
1881 4992 : if (op->op != SETOP_UNION || !op->all)
1882 3210 : return false;
1883 :
1884 : /* Recurse to check inputs */
1885 3322 : return is_simple_union_all_recurse(op->larg, setOpQuery, colTypes) &&
1886 1540 : is_simple_union_all_recurse(op->rarg, setOpQuery, colTypes);
1887 : }
1888 : else
1889 : {
1890 0 : elog(ERROR, "unrecognized node type: %d",
1891 : (int) nodeTag(setOp));
1892 : return false; /* keep compiler quiet */
1893 : }
1894 : }
1895 :
1896 : /*
1897 : * is_safe_append_member
1898 : * Check a subquery that is a leaf of a UNION ALL appendrel to see if it's
1899 : * safe to pull up.
1900 : */
1901 : static bool
1902 3530 : is_safe_append_member(Query *subquery)
1903 : {
1904 : FromExpr *jtnode;
1905 :
1906 : /*
1907 : * It's only safe to pull up the child if its jointree contains exactly
1908 : * one RTE, else the AppendRelInfo data structure breaks. The one base RTE
1909 : * could be buried in several levels of FromExpr, however. Also, if the
1910 : * child's jointree is completely empty, we can pull up because
1911 : * pull_up_simple_subquery will insert a single RTE_RESULT RTE instead.
1912 : *
1913 : * Also, the child can't have any WHERE quals because there's no place to
1914 : * put them in an appendrel. (This is a bit annoying...) If we didn't
1915 : * need to check this, we'd just test whether get_relids_in_jointree()
1916 : * yields a singleton set, to be more consistent with the coding of
1917 : * fix_append_rel_relids().
1918 : */
1919 3530 : jtnode = subquery->jointree;
1920 : Assert(IsA(jtnode, FromExpr));
1921 : /* Check the completely-empty case */
1922 3530 : if (jtnode->fromlist == NIL && jtnode->quals == NULL)
1923 340 : return true;
1924 : /* Check the more general case */
1925 6086 : while (IsA(jtnode, FromExpr))
1926 : {
1927 3198 : if (jtnode->quals != NULL)
1928 302 : return false;
1929 2896 : if (list_length(jtnode->fromlist) != 1)
1930 0 : return false;
1931 2896 : jtnode = linitial(jtnode->fromlist);
1932 : }
1933 2888 : if (!IsA(jtnode, RangeTblRef))
1934 36 : return false;
1935 :
1936 2852 : return true;
1937 : }
1938 :
1939 : /*
1940 : * jointree_contains_lateral_outer_refs
1941 : * Check for disallowed lateral references in a jointree's quals
1942 : *
1943 : * If restricted is false, all level-1 Vars are allowed (but we still must
1944 : * search the jointree, since it might contain outer joins below which there
1945 : * will be restrictions). If restricted is true, return true when any qual
1946 : * in the jointree contains level-1 Vars coming from outside the rels listed
1947 : * in safe_upper_varnos.
1948 : */
1949 : static bool
1950 1856 : jointree_contains_lateral_outer_refs(PlannerInfo *root, Node *jtnode,
1951 : bool restricted,
1952 : Relids safe_upper_varnos)
1953 : {
1954 1856 : if (jtnode == NULL)
1955 0 : return false;
1956 1856 : if (IsA(jtnode, RangeTblRef))
1957 888 : return false;
1958 968 : else if (IsA(jtnode, FromExpr))
1959 : {
1960 820 : FromExpr *f = (FromExpr *) jtnode;
1961 : ListCell *l;
1962 :
1963 : /* First, recurse to check child joins */
1964 1568 : foreach(l, f->fromlist)
1965 : {
1966 756 : if (jointree_contains_lateral_outer_refs(root,
1967 756 : lfirst(l),
1968 : restricted,
1969 : safe_upper_varnos))
1970 8 : return true;
1971 : }
1972 :
1973 : /* Then check the top-level quals */
1974 812 : if (restricted &&
1975 280 : !bms_is_subset(pull_varnos_of_level(root, f->quals, 1),
1976 : safe_upper_varnos))
1977 0 : return true;
1978 : }
1979 148 : else if (IsA(jtnode, JoinExpr))
1980 : {
1981 148 : JoinExpr *j = (JoinExpr *) jtnode;
1982 :
1983 : /*
1984 : * If this is an outer join, we mustn't allow any upper lateral
1985 : * references in or below it.
1986 : */
1987 148 : if (j->jointype != JOIN_INNER)
1988 : {
1989 68 : restricted = true;
1990 68 : safe_upper_varnos = NULL;
1991 : }
1992 :
1993 : /* Check the child joins */
1994 148 : if (jointree_contains_lateral_outer_refs(root,
1995 : j->larg,
1996 : restricted,
1997 : safe_upper_varnos))
1998 0 : return true;
1999 148 : if (jointree_contains_lateral_outer_refs(root,
2000 : j->rarg,
2001 : restricted,
2002 : safe_upper_varnos))
2003 0 : return true;
2004 :
2005 : /* Check the JOIN's qual clauses */
2006 148 : if (restricted &&
2007 148 : !bms_is_subset(pull_varnos_of_level(root, j->quals, 1),
2008 : safe_upper_varnos))
2009 8 : return true;
2010 : }
2011 : else
2012 0 : elog(ERROR, "unrecognized node type: %d",
2013 : (int) nodeTag(jtnode));
2014 952 : return false;
2015 : }
2016 :
2017 : /*
2018 : * Perform pullup_replace_vars everyplace it's needed in the query tree.
2019 : *
2020 : * Caller has already filled *rvcontext with data describing what to
2021 : * substitute for Vars referencing the target subquery. In addition
2022 : * we need the identity of the lowest outer join that can null the
2023 : * target subquery, and its containing appendrel if any.
2024 : */
2025 : static void
2026 33242 : perform_pullup_replace_vars(PlannerInfo *root,
2027 : pullup_replace_vars_context *rvcontext,
2028 : JoinExpr *lowest_nulling_outer_join,
2029 : AppendRelInfo *containing_appendrel)
2030 : {
2031 33242 : Query *parse = root->parse;
2032 : ListCell *lc;
2033 :
2034 : /*
2035 : * Replace all of the top query's references to the subquery's outputs
2036 : * with copies of the adjusted subtlist items, being careful not to
2037 : * replace any of the jointree structure. (This'd be a lot cleaner if we
2038 : * could use query_tree_mutator.) We have to use PHVs in the targetList,
2039 : * returningList, and havingQual, since those are certainly above any
2040 : * outer join. replace_vars_in_jointree tracks its location in the
2041 : * jointree and uses PHVs or not appropriately.
2042 : */
2043 33242 : parse->targetList = (List *)
2044 33242 : pullup_replace_vars((Node *) parse->targetList, rvcontext);
2045 33242 : parse->returningList = (List *)
2046 33242 : pullup_replace_vars((Node *) parse->returningList, rvcontext);
2047 33242 : if (parse->onConflict)
2048 : {
2049 32 : parse->onConflict->onConflictSet = (List *)
2050 16 : pullup_replace_vars((Node *) parse->onConflict->onConflictSet,
2051 : rvcontext);
2052 16 : parse->onConflict->onConflictWhere =
2053 16 : pullup_replace_vars(parse->onConflict->onConflictWhere,
2054 : rvcontext);
2055 :
2056 : /*
2057 : * We assume ON CONFLICT's arbiterElems, arbiterWhere, exclRelTlist
2058 : * can't contain any references to a subquery.
2059 : */
2060 : }
2061 33242 : replace_vars_in_jointree((Node *) parse->jointree, rvcontext,
2062 : lowest_nulling_outer_join);
2063 : Assert(parse->setOperations == NULL);
2064 33238 : parse->havingQual = pullup_replace_vars(parse->havingQual, rvcontext);
2065 :
2066 : /*
2067 : * Replace references in the translated_vars lists of appendrels. When
2068 : * pulling up an appendrel member, we do not need PHVs in the list of the
2069 : * parent appendrel --- there isn't any outer join between. Elsewhere,
2070 : * use PHVs for safety. (This analysis could be made tighter but it seems
2071 : * unlikely to be worth much trouble.)
2072 : */
2073 36118 : foreach(lc, root->append_rel_list)
2074 : {
2075 2880 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
2076 2880 : bool save_need_phvs = rvcontext->need_phvs;
2077 :
2078 2880 : if (appinfo == containing_appendrel)
2079 1578 : rvcontext->need_phvs = false;
2080 2880 : appinfo->translated_vars = (List *)
2081 2880 : pullup_replace_vars((Node *) appinfo->translated_vars, rvcontext);
2082 2880 : rvcontext->need_phvs = save_need_phvs;
2083 : }
2084 :
2085 : /*
2086 : * Replace references in the joinaliasvars lists of join RTEs.
2087 : *
2088 : * You might think that we could avoid using PHVs for alias vars of joins
2089 : * below lowest_nulling_outer_join, but that doesn't work because the
2090 : * alias vars could be referenced above that join; we need the PHVs to be
2091 : * present in such references after the alias vars get flattened. (It
2092 : * might be worth trying to be smarter here, someday.)
2093 : */
2094 91516 : foreach(lc, parse->rtable)
2095 : {
2096 58278 : RangeTblEntry *otherrte = (RangeTblEntry *) lfirst(lc);
2097 :
2098 58278 : if (otherrte->rtekind == RTE_JOIN)
2099 2686 : otherrte->joinaliasvars = (List *)
2100 2686 : pullup_replace_vars((Node *) otherrte->joinaliasvars,
2101 : rvcontext);
2102 : }
2103 33238 : }
2104 :
2105 : /*
2106 : * Helper routine for perform_pullup_replace_vars: do pullup_replace_vars on
2107 : * every expression in the jointree, without changing the jointree structure
2108 : * itself. Ugly, but there's no other way...
2109 : *
2110 : * If we are at or below lowest_nulling_outer_join, we can suppress use of
2111 : * PlaceHolderVars wrapped around the replacement expressions.
2112 : */
2113 : static void
2114 78822 : replace_vars_in_jointree(Node *jtnode,
2115 : pullup_replace_vars_context *context,
2116 : JoinExpr *lowest_nulling_outer_join)
2117 : {
2118 78822 : if (jtnode == NULL)
2119 0 : return;
2120 78822 : if (IsA(jtnode, RangeTblRef))
2121 : {
2122 : /*
2123 : * If the RangeTblRef refers to a LATERAL subquery (that isn't the
2124 : * same subquery we're pulling up), it might contain references to the
2125 : * target subquery, which we must replace. We drive this from the
2126 : * jointree scan, rather than a scan of the rtable, for a couple of
2127 : * reasons: we can avoid processing no-longer-referenced RTEs, and we
2128 : * can use the appropriate setting of need_phvs depending on whether
2129 : * the RTE is above possibly-nulling outer joins or not.
2130 : */
2131 39676 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2132 :
2133 39676 : if (varno != context->varno) /* ignore target subquery itself */
2134 : {
2135 8012 : RangeTblEntry *rte = rt_fetch(varno, context->root->parse->rtable);
2136 :
2137 : Assert(rte != context->target_rte);
2138 8012 : if (rte->lateral)
2139 : {
2140 564 : switch (rte->rtekind)
2141 : {
2142 0 : case RTE_RELATION:
2143 : /* shouldn't be marked LATERAL unless tablesample */
2144 : Assert(rte->tablesample);
2145 0 : rte->tablesample = (TableSampleClause *)
2146 0 : pullup_replace_vars((Node *) rte->tablesample,
2147 : context);
2148 0 : break;
2149 284 : case RTE_SUBQUERY:
2150 284 : rte->subquery =
2151 284 : pullup_replace_vars_subquery(rte->subquery,
2152 : context);
2153 284 : break;
2154 236 : case RTE_FUNCTION:
2155 236 : rte->functions = (List *)
2156 236 : pullup_replace_vars((Node *) rte->functions,
2157 : context);
2158 236 : break;
2159 44 : case RTE_TABLEFUNC:
2160 44 : rte->tablefunc = (TableFunc *)
2161 44 : pullup_replace_vars((Node *) rte->tablefunc,
2162 : context);
2163 44 : break;
2164 0 : case RTE_VALUES:
2165 0 : rte->values_lists = (List *)
2166 0 : pullup_replace_vars((Node *) rte->values_lists,
2167 : context);
2168 0 : break;
2169 0 : case RTE_JOIN:
2170 : case RTE_CTE:
2171 : case RTE_NAMEDTUPLESTORE:
2172 : case RTE_RESULT:
2173 : /* these shouldn't be marked LATERAL */
2174 : Assert(false);
2175 0 : break;
2176 : }
2177 39676 : }
2178 : }
2179 : }
2180 39146 : else if (IsA(jtnode, FromExpr))
2181 : {
2182 34728 : FromExpr *f = (FromExpr *) jtnode;
2183 : ListCell *l;
2184 :
2185 71472 : foreach(l, f->fromlist)
2186 36744 : replace_vars_in_jointree(lfirst(l), context,
2187 : lowest_nulling_outer_join);
2188 34728 : f->quals = pullup_replace_vars(f->quals, context);
2189 : }
2190 4418 : else if (IsA(jtnode, JoinExpr))
2191 : {
2192 4418 : JoinExpr *j = (JoinExpr *) jtnode;
2193 4418 : bool save_need_phvs = context->need_phvs;
2194 :
2195 4418 : if (j == lowest_nulling_outer_join)
2196 : {
2197 : /* no more PHVs in or below this join */
2198 1344 : context->need_phvs = false;
2199 1344 : lowest_nulling_outer_join = NULL;
2200 : }
2201 4418 : replace_vars_in_jointree(j->larg, context, lowest_nulling_outer_join);
2202 4418 : replace_vars_in_jointree(j->rarg, context, lowest_nulling_outer_join);
2203 :
2204 : /*
2205 : * Use PHVs within the join quals of a full join, even when it's the
2206 : * lowest nulling outer join. Otherwise, we cannot identify which
2207 : * side of the join a pulled-up var-free expression came from, which
2208 : * can lead to failure to make a plan at all because none of the quals
2209 : * appear to be mergeable or hashable conditions. For this purpose we
2210 : * don't care about the state of wrap_non_vars, so leave it alone.
2211 : */
2212 4418 : if (j->jointype == JOIN_FULL)
2213 384 : context->need_phvs = true;
2214 :
2215 4418 : j->quals = pullup_replace_vars(j->quals, context);
2216 :
2217 : /*
2218 : * We don't bother to update the colvars list, since it won't be used
2219 : * again ...
2220 : */
2221 4418 : context->need_phvs = save_need_phvs;
2222 : }
2223 : else
2224 0 : elog(ERROR, "unrecognized node type: %d",
2225 : (int) nodeTag(jtnode));
2226 : }
2227 :
2228 : /*
2229 : * Apply pullup variable replacement throughout an expression tree
2230 : *
2231 : * Returns a modified copy of the tree, so this can't be used where we
2232 : * need to do in-place replacement.
2233 : */
2234 : static Node *
2235 144746 : pullup_replace_vars(Node *expr, pullup_replace_vars_context *context)
2236 : {
2237 144746 : return replace_rte_variables(expr,
2238 : context->varno, 0,
2239 : pullup_replace_vars_callback,
2240 : (void *) context,
2241 : context->outer_hasSubLinks);
2242 : }
2243 :
2244 : static Node *
2245 95558 : pullup_replace_vars_callback(Var *var,
2246 : replace_rte_variables_context *context)
2247 : {
2248 95558 : pullup_replace_vars_context *rcon = (pullup_replace_vars_context *) context->callback_arg;
2249 95558 : int varattno = var->varattno;
2250 : Node *newnode;
2251 :
2252 : /*
2253 : * If PlaceHolderVars are needed, we cache the modified expressions in
2254 : * rcon->rv_cache[]. This is not in hopes of any material speed gain
2255 : * within this function, but to avoid generating identical PHVs with
2256 : * different IDs. That would result in duplicate evaluations at runtime,
2257 : * and possibly prevent optimizations that rely on recognizing different
2258 : * references to the same subquery output as being equal(). So it's worth
2259 : * a bit of extra effort to avoid it.
2260 : */
2261 95558 : if (rcon->need_phvs &&
2262 7426 : varattno >= InvalidAttrNumber &&
2263 7426 : varattno <= list_length(rcon->targetlist) &&
2264 7426 : rcon->rv_cache[varattno] != NULL)
2265 : {
2266 : /* Just copy the entry and fall through to adjust its varlevelsup */
2267 4072 : newnode = copyObject(rcon->rv_cache[varattno]);
2268 : }
2269 91486 : else if (varattno == InvalidAttrNumber)
2270 : {
2271 : /* Must expand whole-tuple reference into RowExpr */
2272 : RowExpr *rowexpr;
2273 : List *colnames;
2274 : List *fields;
2275 280 : bool save_need_phvs = rcon->need_phvs;
2276 280 : int save_sublevelsup = context->sublevels_up;
2277 :
2278 : /*
2279 : * If generating an expansion for a var of a named rowtype (ie, this
2280 : * is a plain relation RTE), then we must include dummy items for
2281 : * dropped columns. If the var is RECORD (ie, this is a JOIN), then
2282 : * omit dropped columns. Either way, attach column names to the
2283 : * RowExpr for use of ruleutils.c.
2284 : *
2285 : * In order to be able to cache the results, we always generate the
2286 : * expansion with varlevelsup = 0, and then adjust if needed.
2287 : */
2288 280 : expandRTE(rcon->target_rte,
2289 : var->varno, 0 /* not varlevelsup */ , var->location,
2290 280 : (var->vartype != RECORDOID),
2291 : &colnames, &fields);
2292 : /* Adjust the generated per-field Vars, but don't insert PHVs */
2293 280 : rcon->need_phvs = false;
2294 280 : context->sublevels_up = 0; /* to match the expandRTE output */
2295 280 : fields = (List *) replace_rte_variables_mutator((Node *) fields,
2296 : context);
2297 280 : rcon->need_phvs = save_need_phvs;
2298 280 : context->sublevels_up = save_sublevelsup;
2299 :
2300 280 : rowexpr = makeNode(RowExpr);
2301 280 : rowexpr->args = fields;
2302 280 : rowexpr->row_typeid = var->vartype;
2303 280 : rowexpr->row_format = COERCE_IMPLICIT_CAST;
2304 280 : rowexpr->colnames = colnames;
2305 280 : rowexpr->location = var->location;
2306 280 : newnode = (Node *) rowexpr;
2307 :
2308 : /*
2309 : * Insert PlaceHolderVar if needed. Notice that we are wrapping one
2310 : * PlaceHolderVar around the whole RowExpr, rather than putting one
2311 : * around each element of the row. This is because we need the
2312 : * expression to yield NULL, not ROW(NULL,NULL,...) when it is forced
2313 : * to null by an outer join.
2314 : */
2315 280 : if (rcon->need_phvs)
2316 : {
2317 : /* RowExpr is certainly not strict, so always need PHV */
2318 : newnode = (Node *)
2319 8 : make_placeholder_expr(rcon->root,
2320 : (Expr *) newnode,
2321 : bms_make_singleton(rcon->varno));
2322 : /* cache it with the PHV, and with varlevelsup still zero */
2323 8 : rcon->rv_cache[InvalidAttrNumber] = copyObject(newnode);
2324 : }
2325 : }
2326 : else
2327 : {
2328 : /* Normal case referencing one targetlist element */
2329 91206 : TargetEntry *tle = get_tle_by_resno(rcon->targetlist, varattno);
2330 :
2331 91206 : if (tle == NULL) /* shouldn't happen */
2332 0 : elog(ERROR, "could not find attribute %d in subquery targetlist",
2333 : varattno);
2334 :
2335 : /* Make a copy of the tlist item to return */
2336 91206 : newnode = (Node *) copyObject(tle->expr);
2337 :
2338 : /* Insert PlaceHolderVar if needed */
2339 91206 : if (rcon->need_phvs)
2340 : {
2341 : bool wrap;
2342 :
2343 3346 : if (newnode && IsA(newnode, Var) &&
2344 2516 : ((Var *) newnode)->varlevelsup == 0)
2345 : {
2346 : /*
2347 : * Simple Vars always escape being wrapped, unless they are
2348 : * lateral references to something outside the subquery being
2349 : * pulled up. (Even then, we could omit the PlaceHolderVar if
2350 : * the referenced rel is under the same lowest outer join, but
2351 : * it doesn't seem worth the trouble to check that.)
2352 : */
2353 2504 : if (rcon->target_rte->lateral &&
2354 232 : !bms_is_member(((Var *) newnode)->varno, rcon->relids))
2355 16 : wrap = true;
2356 : else
2357 2488 : wrap = false;
2358 : }
2359 842 : else if (newnode && IsA(newnode, PlaceHolderVar) &&
2360 28 : ((PlaceHolderVar *) newnode)->phlevelsup == 0)
2361 : {
2362 : /* No need to wrap a PlaceHolderVar with another one, either */
2363 28 : wrap = false;
2364 : }
2365 814 : else if (rcon->wrap_non_vars)
2366 : {
2367 : /* Wrap all non-Vars in a PlaceHolderVar */
2368 72 : wrap = true;
2369 : }
2370 : else
2371 : {
2372 : /*
2373 : * If it contains a Var of the subquery being pulled up, and
2374 : * does not contain any non-strict constructs, then it's
2375 : * certainly nullable so we don't need to insert a
2376 : * PlaceHolderVar.
2377 : *
2378 : * This analysis could be tighter: in particular, a non-strict
2379 : * construct hidden within a lower-level PlaceHolderVar is not
2380 : * reason to add another PHV. But for now it doesn't seem
2381 : * worth the code to be more exact.
2382 : *
2383 : * Note: in future maybe we should insert a PlaceHolderVar
2384 : * anyway, if the tlist item is expensive to evaluate?
2385 : *
2386 : * For a LATERAL subquery, we have to check the actual var
2387 : * membership of the node, but if it's non-lateral then any
2388 : * level-zero var must belong to the subquery.
2389 : */
2390 814 : if ((rcon->target_rte->lateral ?
2391 72 : bms_overlap(pull_varnos(rcon->root, (Node *) newnode),
2392 72 : rcon->relids) :
2393 670 : contain_vars_of_level((Node *) newnode, 0)) &&
2394 176 : !contain_nonstrict_functions((Node *) newnode))
2395 : {
2396 : /* No wrap needed */
2397 0 : wrap = false;
2398 : }
2399 : else
2400 : {
2401 : /* Else wrap it in a PlaceHolderVar */
2402 742 : wrap = true;
2403 : }
2404 : }
2405 :
2406 3346 : if (wrap)
2407 : newnode = (Node *)
2408 830 : make_placeholder_expr(rcon->root,
2409 : (Expr *) newnode,
2410 : bms_make_singleton(rcon->varno));
2411 :
2412 : /*
2413 : * Cache it if possible (ie, if the attno is in range, which it
2414 : * probably always should be). We can cache the value even if we
2415 : * decided we didn't need a PHV, since this result will be
2416 : * suitable for any request that has need_phvs.
2417 : */
2418 6692 : if (varattno > InvalidAttrNumber &&
2419 3346 : varattno <= list_length(rcon->targetlist))
2420 3346 : rcon->rv_cache[varattno] = copyObject(newnode);
2421 : }
2422 : }
2423 :
2424 : /* Must adjust varlevelsup if tlist item is from higher query */
2425 95558 : if (var->varlevelsup > 0)
2426 448 : IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
2427 :
2428 95558 : return newnode;
2429 : }
2430 :
2431 : /*
2432 : * Apply pullup variable replacement to a subquery
2433 : *
2434 : * This needs to be different from pullup_replace_vars() because
2435 : * replace_rte_variables will think that it shouldn't increment sublevels_up
2436 : * before entering the Query; so we need to call it with sublevels_up == 1.
2437 : */
2438 : static Query *
2439 284 : pullup_replace_vars_subquery(Query *query,
2440 : pullup_replace_vars_context *context)
2441 : {
2442 : Assert(IsA(query, Query));
2443 284 : return (Query *) replace_rte_variables((Node *) query,
2444 : context->varno, 1,
2445 : pullup_replace_vars_callback,
2446 : (void *) context,
2447 : NULL);
2448 : }
2449 :
2450 :
2451 : /*
2452 : * flatten_simple_union_all
2453 : * Try to optimize top-level UNION ALL structure into an appendrel
2454 : *
2455 : * If a query's setOperations tree consists entirely of simple UNION ALL
2456 : * operations, flatten it into an append relation, which we can process more
2457 : * intelligently than the general setops case. Otherwise, do nothing.
2458 : *
2459 : * In most cases, this can succeed only for a top-level query, because for a
2460 : * subquery in FROM, the parent query's invocation of pull_up_subqueries would
2461 : * already have flattened the UNION via pull_up_simple_union_all. But there
2462 : * are a few cases we can support here but not in that code path, for example
2463 : * when the subquery also contains ORDER BY.
2464 : */
2465 : void
2466 3424 : flatten_simple_union_all(PlannerInfo *root)
2467 : {
2468 3424 : Query *parse = root->parse;
2469 : SetOperationStmt *topop;
2470 : Node *leftmostjtnode;
2471 : int leftmostRTI;
2472 : RangeTblEntry *leftmostRTE;
2473 : int childRTI;
2474 : RangeTblEntry *childRTE;
2475 : RangeTblRef *rtr;
2476 :
2477 : /* Shouldn't be called unless query has setops */
2478 3424 : topop = castNode(SetOperationStmt, parse->setOperations);
2479 : Assert(topop);
2480 :
2481 : /* Can't optimize away a recursive UNION */
2482 3424 : if (root->hasRecursion)
2483 3244 : return;
2484 :
2485 : /*
2486 : * Recursively check the tree of set operations. If not all UNION ALL
2487 : * with identical column types, punt.
2488 : */
2489 2966 : if (!is_simple_union_all_recurse((Node *) topop, parse, topop->colTypes))
2490 2786 : return;
2491 :
2492 : /*
2493 : * Locate the leftmost leaf query in the setops tree. The upper query's
2494 : * Vars all refer to this RTE (see transformSetOperationStmt).
2495 : */
2496 180 : leftmostjtnode = topop->larg;
2497 278 : while (leftmostjtnode && IsA(leftmostjtnode, SetOperationStmt))
2498 98 : leftmostjtnode = ((SetOperationStmt *) leftmostjtnode)->larg;
2499 : Assert(leftmostjtnode && IsA(leftmostjtnode, RangeTblRef));
2500 180 : leftmostRTI = ((RangeTblRef *) leftmostjtnode)->rtindex;
2501 180 : leftmostRTE = rt_fetch(leftmostRTI, parse->rtable);
2502 : Assert(leftmostRTE->rtekind == RTE_SUBQUERY);
2503 :
2504 : /*
2505 : * Make a copy of the leftmost RTE and add it to the rtable. This copy
2506 : * will represent the leftmost leaf query in its capacity as a member of
2507 : * the appendrel. The original will represent the appendrel as a whole.
2508 : * (We must do things this way because the upper query's Vars have to be
2509 : * seen as referring to the whole appendrel.)
2510 : */
2511 180 : childRTE = copyObject(leftmostRTE);
2512 180 : parse->rtable = lappend(parse->rtable, childRTE);
2513 180 : childRTI = list_length(parse->rtable);
2514 :
2515 : /* Modify the setops tree to reference the child copy */
2516 180 : ((RangeTblRef *) leftmostjtnode)->rtindex = childRTI;
2517 :
2518 : /* Modify the formerly-leftmost RTE to mark it as an appendrel parent */
2519 180 : leftmostRTE->inh = true;
2520 :
2521 : /*
2522 : * Form a RangeTblRef for the appendrel, and insert it into FROM. The top
2523 : * Query of a setops tree should have had an empty FromClause initially.
2524 : */
2525 180 : rtr = makeNode(RangeTblRef);
2526 180 : rtr->rtindex = leftmostRTI;
2527 : Assert(parse->jointree->fromlist == NIL);
2528 180 : parse->jointree->fromlist = list_make1(rtr);
2529 :
2530 : /*
2531 : * Now pretend the query has no setops. We must do this before trying to
2532 : * do subquery pullup, because of Assert in pull_up_simple_subquery.
2533 : */
2534 180 : parse->setOperations = NULL;
2535 :
2536 : /*
2537 : * Build AppendRelInfo information, and apply pull_up_subqueries to the
2538 : * leaf queries of the UNION ALL. (We must do that now because they
2539 : * weren't previously referenced by the jointree, and so were missed by
2540 : * the main invocation of pull_up_subqueries.)
2541 : */
2542 180 : pull_up_union_leaf_queries((Node *) topop, root, leftmostRTI, parse, 0);
2543 : }
2544 :
2545 :
2546 : /*
2547 : * reduce_outer_joins
2548 : * Attempt to reduce outer joins to plain inner joins.
2549 : *
2550 : * The idea here is that given a query like
2551 : * SELECT ... FROM a LEFT JOIN b ON (...) WHERE b.y = 42;
2552 : * we can reduce the LEFT JOIN to a plain JOIN if the "=" operator in WHERE
2553 : * is strict. The strict operator will always return NULL, causing the outer
2554 : * WHERE to fail, on any row where the LEFT JOIN filled in NULLs for b's
2555 : * columns. Therefore, there's no need for the join to produce null-extended
2556 : * rows in the first place --- which makes it a plain join not an outer join.
2557 : * (This scenario may not be very likely in a query written out by hand, but
2558 : * it's reasonably likely when pushing quals down into complex views.)
2559 : *
2560 : * More generally, an outer join can be reduced in strength if there is a
2561 : * strict qual above it in the qual tree that constrains a Var from the
2562 : * nullable side of the join to be non-null. (For FULL joins this applies
2563 : * to each side separately.)
2564 : *
2565 : * Another transformation we apply here is to recognize cases like
2566 : * SELECT ... FROM a LEFT JOIN b ON (a.x = b.y) WHERE b.y IS NULL;
2567 : * If the join clause is strict for b.y, then only null-extended rows could
2568 : * pass the upper WHERE, and we can conclude that what the query is really
2569 : * specifying is an anti-semijoin. We change the join type from JOIN_LEFT
2570 : * to JOIN_ANTI. The IS NULL clause then becomes redundant, and must be
2571 : * removed to prevent bogus selectivity calculations, but we leave it to
2572 : * distribute_qual_to_rels to get rid of such clauses.
2573 : *
2574 : * Also, we get rid of JOIN_RIGHT cases by flipping them around to become
2575 : * JOIN_LEFT. This saves some code here and in some later planner routines,
2576 : * but the main reason to do it is to not need to invent a JOIN_REVERSE_ANTI
2577 : * join type.
2578 : *
2579 : * To ease recognition of strict qual clauses, we require this routine to be
2580 : * run after expression preprocessing (i.e., qual canonicalization and JOIN
2581 : * alias-var expansion).
2582 : */
2583 : void
2584 62216 : reduce_outer_joins(PlannerInfo *root)
2585 : {
2586 : reduce_outer_joins_state *state;
2587 :
2588 : /*
2589 : * To avoid doing strictness checks on more quals than necessary, we want
2590 : * to stop descending the jointree as soon as there are no outer joins
2591 : * below our current point. This consideration forces a two-pass process.
2592 : * The first pass gathers information about which base rels appear below
2593 : * each side of each join clause, and about whether there are outer
2594 : * join(s) below each side of each join clause. The second pass examines
2595 : * qual clauses and changes join types as it descends the tree.
2596 : */
2597 62216 : state = reduce_outer_joins_pass1((Node *) root->parse->jointree);
2598 :
2599 : /* planner.c shouldn't have called me if no outer joins */
2600 62216 : if (state == NULL || !state->contains_outer)
2601 0 : elog(ERROR, "so where are the outer joins?");
2602 :
2603 62216 : reduce_outer_joins_pass2((Node *) root->parse->jointree,
2604 : state, root, NULL, NIL, NIL);
2605 62216 : }
2606 :
2607 : /*
2608 : * reduce_outer_joins_pass1 - phase 1 data collection
2609 : *
2610 : * Returns a state node describing the given jointree node.
2611 : */
2612 : static reduce_outer_joins_state *
2613 342498 : reduce_outer_joins_pass1(Node *jtnode)
2614 : {
2615 : reduce_outer_joins_state *result;
2616 :
2617 : result = (reduce_outer_joins_state *)
2618 342498 : palloc(sizeof(reduce_outer_joins_state));
2619 342498 : result->relids = NULL;
2620 342498 : result->contains_outer = false;
2621 342498 : result->sub_states = NIL;
2622 :
2623 342498 : if (jtnode == NULL)
2624 0 : return result;
2625 342498 : if (IsA(jtnode, RangeTblRef))
2626 : {
2627 171294 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2628 :
2629 171294 : result->relids = bms_make_singleton(varno);
2630 : }
2631 171204 : else if (IsA(jtnode, FromExpr))
2632 : {
2633 63442 : FromExpr *f = (FromExpr *) jtnode;
2634 : ListCell *l;
2635 :
2636 128200 : foreach(l, f->fromlist)
2637 : {
2638 : reduce_outer_joins_state *sub_state;
2639 :
2640 64758 : sub_state = reduce_outer_joins_pass1(lfirst(l));
2641 129516 : result->relids = bms_add_members(result->relids,
2642 64758 : sub_state->relids);
2643 64758 : result->contains_outer |= sub_state->contains_outer;
2644 64758 : result->sub_states = lappend(result->sub_states, sub_state);
2645 : }
2646 : }
2647 107762 : else if (IsA(jtnode, JoinExpr))
2648 : {
2649 107762 : JoinExpr *j = (JoinExpr *) jtnode;
2650 : reduce_outer_joins_state *sub_state;
2651 :
2652 : /* join's own RT index is not wanted in result->relids */
2653 107762 : if (IS_OUTER_JOIN(j->jointype))
2654 79208 : result->contains_outer = true;
2655 :
2656 107762 : sub_state = reduce_outer_joins_pass1(j->larg);
2657 215524 : result->relids = bms_add_members(result->relids,
2658 107762 : sub_state->relids);
2659 107762 : result->contains_outer |= sub_state->contains_outer;
2660 107762 : result->sub_states = lappend(result->sub_states, sub_state);
2661 :
2662 107762 : sub_state = reduce_outer_joins_pass1(j->rarg);
2663 215524 : result->relids = bms_add_members(result->relids,
2664 107762 : sub_state->relids);
2665 107762 : result->contains_outer |= sub_state->contains_outer;
2666 107762 : result->sub_states = lappend(result->sub_states, sub_state);
2667 : }
2668 : else
2669 0 : elog(ERROR, "unrecognized node type: %d",
2670 : (int) nodeTag(jtnode));
2671 342498 : return result;
2672 : }
2673 :
2674 : /*
2675 : * reduce_outer_joins_pass2 - phase 2 processing
2676 : *
2677 : * jtnode: current jointree node
2678 : * state: state data collected by phase 1 for this node
2679 : * root: toplevel planner state
2680 : * nonnullable_rels: set of base relids forced non-null by upper quals
2681 : * nonnullable_vars: list of Vars forced non-null by upper quals
2682 : * forced_null_vars: list of Vars forced null by upper quals
2683 : */
2684 : static void
2685 142494 : reduce_outer_joins_pass2(Node *jtnode,
2686 : reduce_outer_joins_state *state,
2687 : PlannerInfo *root,
2688 : Relids nonnullable_rels,
2689 : List *nonnullable_vars,
2690 : List *forced_null_vars)
2691 : {
2692 : /*
2693 : * pass 2 should never descend as far as an empty subnode or base rel,
2694 : * because it's only called on subtrees marked as contains_outer.
2695 : */
2696 142494 : if (jtnode == NULL)
2697 0 : elog(ERROR, "reached empty jointree");
2698 142494 : if (IsA(jtnode, RangeTblRef))
2699 0 : elog(ERROR, "reached base rel");
2700 142494 : else if (IsA(jtnode, FromExpr))
2701 : {
2702 62934 : FromExpr *f = (FromExpr *) jtnode;
2703 : ListCell *l;
2704 : ListCell *s;
2705 : Relids pass_nonnullable_rels;
2706 : List *pass_nonnullable_vars;
2707 : List *pass_forced_null_vars;
2708 :
2709 : /* Scan quals to see if we can add any constraints */
2710 62934 : pass_nonnullable_rels = find_nonnullable_rels(f->quals);
2711 62934 : pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
2712 : nonnullable_rels);
2713 62934 : pass_nonnullable_vars = find_nonnullable_vars(f->quals);
2714 62934 : pass_nonnullable_vars = list_concat(pass_nonnullable_vars,
2715 : nonnullable_vars);
2716 62934 : pass_forced_null_vars = find_forced_null_vars(f->quals);
2717 62934 : pass_forced_null_vars = list_concat(pass_forced_null_vars,
2718 : forced_null_vars);
2719 : /* And recurse --- but only into interesting subtrees */
2720 : Assert(list_length(f->fromlist) == list_length(state->sub_states));
2721 127100 : forboth(l, f->fromlist, s, state->sub_states)
2722 : {
2723 64166 : reduce_outer_joins_state *sub_state = lfirst(s);
2724 :
2725 64166 : if (sub_state->contains_outer)
2726 62954 : reduce_outer_joins_pass2(lfirst(l), sub_state, root,
2727 : pass_nonnullable_rels,
2728 : pass_nonnullable_vars,
2729 : pass_forced_null_vars);
2730 : }
2731 62934 : bms_free(pass_nonnullable_rels);
2732 : /* can't so easily clean up var lists, unfortunately */
2733 : }
2734 79560 : else if (IsA(jtnode, JoinExpr))
2735 : {
2736 79560 : JoinExpr *j = (JoinExpr *) jtnode;
2737 79560 : int rtindex = j->rtindex;
2738 79560 : JoinType jointype = j->jointype;
2739 79560 : reduce_outer_joins_state *left_state = linitial(state->sub_states);
2740 79560 : reduce_outer_joins_state *right_state = lsecond(state->sub_states);
2741 79560 : List *local_nonnullable_vars = NIL;
2742 79560 : bool computed_local_nonnullable_vars = false;
2743 :
2744 : /* Can we simplify this join? */
2745 79560 : switch (jointype)
2746 : {
2747 344 : case JOIN_INNER:
2748 344 : break;
2749 78214 : case JOIN_LEFT:
2750 78214 : if (bms_overlap(nonnullable_rels, right_state->relids))
2751 770 : jointype = JOIN_INNER;
2752 78214 : break;
2753 188 : case JOIN_RIGHT:
2754 188 : if (bms_overlap(nonnullable_rels, left_state->relids))
2755 28 : jointype = JOIN_INNER;
2756 188 : break;
2757 602 : case JOIN_FULL:
2758 602 : if (bms_overlap(nonnullable_rels, left_state->relids))
2759 : {
2760 0 : if (bms_overlap(nonnullable_rels, right_state->relids))
2761 0 : jointype = JOIN_INNER;
2762 : else
2763 0 : jointype = JOIN_LEFT;
2764 : }
2765 : else
2766 : {
2767 602 : if (bms_overlap(nonnullable_rels, right_state->relids))
2768 12 : jointype = JOIN_RIGHT;
2769 : }
2770 602 : break;
2771 212 : case JOIN_SEMI:
2772 : case JOIN_ANTI:
2773 :
2774 : /*
2775 : * These could only have been introduced by pull_up_sublinks,
2776 : * so there's no way that upper quals could refer to their
2777 : * righthand sides, and no point in checking.
2778 : */
2779 212 : break;
2780 0 : default:
2781 0 : elog(ERROR, "unrecognized join type: %d",
2782 : (int) jointype);
2783 : break;
2784 : }
2785 :
2786 : /*
2787 : * Convert JOIN_RIGHT to JOIN_LEFT. Note that in the case where we
2788 : * reduced JOIN_FULL to JOIN_RIGHT, this will mean the JoinExpr no
2789 : * longer matches the internal ordering of any CoalesceExpr's built to
2790 : * represent merged join variables. We don't care about that at
2791 : * present, but be wary of it ...
2792 : */
2793 79560 : if (jointype == JOIN_RIGHT)
2794 : {
2795 : Node *tmparg;
2796 :
2797 172 : tmparg = j->larg;
2798 172 : j->larg = j->rarg;
2799 172 : j->rarg = tmparg;
2800 172 : jointype = JOIN_LEFT;
2801 172 : right_state = linitial(state->sub_states);
2802 172 : left_state = lsecond(state->sub_states);
2803 : }
2804 :
2805 : /*
2806 : * See if we can reduce JOIN_LEFT to JOIN_ANTI. This is the case if
2807 : * the join's own quals are strict for any var that was forced null by
2808 : * higher qual levels. NOTE: there are other ways that we could
2809 : * detect an anti-join, in particular if we were to check whether Vars
2810 : * coming from the RHS must be non-null because of table constraints.
2811 : * That seems complicated and expensive though (in particular, one
2812 : * would have to be wary of lower outer joins). For the moment this
2813 : * seems sufficient.
2814 : */
2815 79560 : if (jointype == JOIN_LEFT)
2816 : {
2817 : List *overlap;
2818 :
2819 77616 : local_nonnullable_vars = find_nonnullable_vars(j->quals);
2820 77616 : computed_local_nonnullable_vars = true;
2821 :
2822 : /*
2823 : * It's not sufficient to check whether local_nonnullable_vars and
2824 : * forced_null_vars overlap: we need to know if the overlap
2825 : * includes any RHS variables.
2826 : */
2827 77616 : overlap = list_intersection(local_nonnullable_vars,
2828 : forced_null_vars);
2829 78334 : if (overlap != NIL &&
2830 718 : bms_overlap(pull_varnos(root, (Node *) overlap),
2831 718 : right_state->relids))
2832 702 : jointype = JOIN_ANTI;
2833 : }
2834 :
2835 : /* Apply the jointype change, if any, to both jointree node and RTE */
2836 79560 : if (rtindex && jointype != j->jointype)
2837 : {
2838 1672 : RangeTblEntry *rte = rt_fetch(rtindex, root->parse->rtable);
2839 :
2840 : Assert(rte->rtekind == RTE_JOIN);
2841 : Assert(rte->jointype == j->jointype);
2842 1672 : rte->jointype = jointype;
2843 : }
2844 79560 : j->jointype = jointype;
2845 :
2846 : /* Only recurse if there's more to do below here */
2847 79560 : if (left_state->contains_outer || right_state->contains_outer)
2848 : {
2849 : Relids local_nonnullable_rels;
2850 : List *local_forced_null_vars;
2851 : Relids pass_nonnullable_rels;
2852 : List *pass_nonnullable_vars;
2853 : List *pass_forced_null_vars;
2854 :
2855 : /*
2856 : * If this join is (now) inner, we can add any constraints its
2857 : * quals provide to those we got from above. But if it is outer,
2858 : * we can pass down the local constraints only into the nullable
2859 : * side, because an outer join never eliminates any rows from its
2860 : * non-nullable side. Also, there is no point in passing upper
2861 : * constraints into the nullable side, since if there were any
2862 : * we'd have been able to reduce the join. (In the case of upper
2863 : * forced-null constraints, we *must not* pass them into the
2864 : * nullable side --- they either applied here, or not.) The upshot
2865 : * is that we pass either the local or the upper constraints,
2866 : * never both, to the children of an outer join.
2867 : *
2868 : * Note that a SEMI join works like an inner join here: it's okay
2869 : * to pass down both local and upper constraints. (There can't be
2870 : * any upper constraints affecting its inner side, but it's not
2871 : * worth having a separate code path to avoid passing them.)
2872 : *
2873 : * At a FULL join we just punt and pass nothing down --- is it
2874 : * possible to be smarter?
2875 : */
2876 17304 : if (jointype != JOIN_FULL)
2877 : {
2878 17198 : local_nonnullable_rels = find_nonnullable_rels(j->quals);
2879 17198 : if (!computed_local_nonnullable_vars)
2880 754 : local_nonnullable_vars = find_nonnullable_vars(j->quals);
2881 17198 : local_forced_null_vars = find_forced_null_vars(j->quals);
2882 17198 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
2883 : {
2884 : /* OK to merge upper and local constraints */
2885 550 : local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
2886 : nonnullable_rels);
2887 550 : local_nonnullable_vars = list_concat(local_nonnullable_vars,
2888 : nonnullable_vars);
2889 550 : local_forced_null_vars = list_concat(local_forced_null_vars,
2890 : forced_null_vars);
2891 : }
2892 : }
2893 : else
2894 : {
2895 : /* no use in calculating these */
2896 106 : local_nonnullable_rels = NULL;
2897 106 : local_forced_null_vars = NIL;
2898 : }
2899 :
2900 17304 : if (left_state->contains_outer)
2901 : {
2902 16988 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
2903 : {
2904 : /* pass union of local and upper constraints */
2905 448 : pass_nonnullable_rels = local_nonnullable_rels;
2906 448 : pass_nonnullable_vars = local_nonnullable_vars;
2907 448 : pass_forced_null_vars = local_forced_null_vars;
2908 : }
2909 16540 : else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
2910 : {
2911 : /* can't pass local constraints to non-nullable side */
2912 16458 : pass_nonnullable_rels = nonnullable_rels;
2913 16458 : pass_nonnullable_vars = nonnullable_vars;
2914 16458 : pass_forced_null_vars = forced_null_vars;
2915 : }
2916 : else
2917 : {
2918 : /* no constraints pass through JOIN_FULL */
2919 82 : pass_nonnullable_rels = NULL;
2920 82 : pass_nonnullable_vars = NIL;
2921 82 : pass_forced_null_vars = NIL;
2922 : }
2923 16988 : reduce_outer_joins_pass2(j->larg, left_state, root,
2924 : pass_nonnullable_rels,
2925 : pass_nonnullable_vars,
2926 : pass_forced_null_vars);
2927 : }
2928 :
2929 17304 : if (right_state->contains_outer)
2930 : {
2931 336 : if (jointype != JOIN_FULL) /* ie, INNER/LEFT/SEMI/ANTI */
2932 : {
2933 : /* pass appropriate constraints, per comment above */
2934 312 : pass_nonnullable_rels = local_nonnullable_rels;
2935 312 : pass_nonnullable_vars = local_nonnullable_vars;
2936 312 : pass_forced_null_vars = local_forced_null_vars;
2937 : }
2938 : else
2939 : {
2940 : /* no constraints pass through JOIN_FULL */
2941 24 : pass_nonnullable_rels = NULL;
2942 24 : pass_nonnullable_vars = NIL;
2943 24 : pass_forced_null_vars = NIL;
2944 : }
2945 336 : reduce_outer_joins_pass2(j->rarg, right_state, root,
2946 : pass_nonnullable_rels,
2947 : pass_nonnullable_vars,
2948 : pass_forced_null_vars);
2949 : }
2950 17304 : bms_free(local_nonnullable_rels);
2951 : }
2952 : }
2953 : else
2954 0 : elog(ERROR, "unrecognized node type: %d",
2955 : (int) nodeTag(jtnode));
2956 142494 : }
2957 :
2958 :
2959 : /*
2960 : * remove_useless_result_rtes
2961 : * Attempt to remove RTE_RESULT RTEs from the join tree.
2962 : *
2963 : * We can remove RTE_RESULT entries from the join tree using the knowledge
2964 : * that RTE_RESULT returns exactly one row and has no output columns. Hence,
2965 : * if one is inner-joined to anything else, we can delete it. Optimizations
2966 : * are also possible for some outer-join cases, as detailed below.
2967 : *
2968 : * Some of these optimizations depend on recognizing empty (constant-true)
2969 : * quals for FromExprs and JoinExprs. That makes it useful to apply this
2970 : * optimization pass after expression preprocessing, since that will have
2971 : * eliminated constant-true quals, allowing more cases to be recognized as
2972 : * optimizable. What's more, the usual reason for an RTE_RESULT to be present
2973 : * is that we pulled up a subquery or VALUES clause, thus very possibly
2974 : * replacing Vars with constants, making it more likely that a qual can be
2975 : * reduced to constant true. Also, because some optimizations depend on
2976 : * the outer-join type, it's best to have done reduce_outer_joins() first.
2977 : *
2978 : * A PlaceHolderVar referencing an RTE_RESULT RTE poses an obstacle to this
2979 : * process: we must remove the RTE_RESULT's relid from the PHV's phrels, but
2980 : * we must not reduce the phrels set to empty. If that would happen, and
2981 : * the RTE_RESULT is an immediate child of an outer join, we have to give up
2982 : * and not remove the RTE_RESULT: there is noplace else to evaluate the
2983 : * PlaceHolderVar. (That is, in such cases the RTE_RESULT *does* have output
2984 : * columns.) But if the RTE_RESULT is an immediate child of an inner join,
2985 : * we can usually change the PlaceHolderVar's phrels so as to evaluate it at
2986 : * the inner join instead. This is OK because we really only care that PHVs
2987 : * are evaluated above or below the correct outer joins. We can't, however,
2988 : * postpone the evaluation of a PHV to above where it is used; so there are
2989 : * some checks below on whether output PHVs are laterally referenced in the
2990 : * other join input rel(s).
2991 : *
2992 : * We used to try to do this work as part of pull_up_subqueries() where the
2993 : * potentially-optimizable cases get introduced; but it's way simpler, and
2994 : * more effective, to do it separately.
2995 : */
2996 : void
2997 134706 : remove_useless_result_rtes(PlannerInfo *root)
2998 : {
2999 : ListCell *cell;
3000 :
3001 : /* Top level of jointree must always be a FromExpr */
3002 : Assert(IsA(root->parse->jointree, FromExpr));
3003 : /* Recurse ... */
3004 269412 : root->parse->jointree = (FromExpr *)
3005 134706 : remove_useless_results_recurse(root, (Node *) root->parse->jointree);
3006 : /* We should still have a FromExpr */
3007 : Assert(IsA(root->parse->jointree, FromExpr));
3008 :
3009 : /*
3010 : * Remove any PlanRowMark referencing an RTE_RESULT RTE. We obviously
3011 : * must do that for any RTE_RESULT that we just removed. But one for a
3012 : * RTE that we did not remove can be dropped anyway: since the RTE has
3013 : * only one possible output row, there is no need for EPQ to mark and
3014 : * restore that row.
3015 : *
3016 : * It's necessary, not optional, to remove the PlanRowMark for a surviving
3017 : * RTE_RESULT RTE; otherwise we'll generate a whole-row Var for the
3018 : * RTE_RESULT, which the executor has no support for.
3019 : */
3020 134730 : foreach(cell, root->rowMarks)
3021 : {
3022 24 : PlanRowMark *rc = (PlanRowMark *) lfirst(cell);
3023 :
3024 24 : if (rt_fetch(rc->rti, root->parse->rtable)->rtekind == RTE_RESULT)
3025 16 : root->rowMarks = foreach_delete_current(root->rowMarks, cell);
3026 : }
3027 134706 : }
3028 :
3029 : /*
3030 : * remove_useless_results_recurse
3031 : * Recursive guts of remove_useless_result_rtes.
3032 : *
3033 : * This recursively processes the jointree and returns a modified jointree.
3034 : */
3035 : static Node *
3036 271504 : remove_useless_results_recurse(PlannerInfo *root, Node *jtnode)
3037 : {
3038 : Assert(jtnode != NULL);
3039 271504 : if (IsA(jtnode, RangeTblRef))
3040 : {
3041 : /* Can't immediately do anything with a RangeTblRef */
3042 : }
3043 135746 : else if (IsA(jtnode, FromExpr))
3044 : {
3045 135052 : FromExpr *f = (FromExpr *) jtnode;
3046 135052 : Relids result_relids = NULL;
3047 : ListCell *cell;
3048 :
3049 : /*
3050 : * We can drop RTE_RESULT rels from the fromlist so long as at least
3051 : * one child remains, since joining to a one-row table changes
3052 : * nothing. (But we can't drop a RTE_RESULT that computes PHV(s) that
3053 : * are needed by some sibling. The cleanup transformation below would
3054 : * reassign the PHVs to be computed at the join, which is too late for
3055 : * the sibling's use.) The easiest way to mechanize this rule is to
3056 : * modify the list in-place.
3057 : */
3058 270462 : foreach(cell, f->fromlist)
3059 : {
3060 135410 : Node *child = (Node *) lfirst(cell);
3061 : int varno;
3062 :
3063 : /* Recursively transform child ... */
3064 135410 : child = remove_useless_results_recurse(root, child);
3065 : /* ... and stick it back into the tree */
3066 135410 : lfirst(cell) = child;
3067 :
3068 : /*
3069 : * If it's an RTE_RESULT with at least one sibling, and no sibling
3070 : * references dependent PHVs, we can drop it. We don't yet know
3071 : * what the inner join's final relid set will be, so postpone
3072 : * cleanup of PHVs etc till after this loop.
3073 : */
3074 135990 : if (list_length(f->fromlist) > 1 &&
3075 580 : (varno = get_result_relid(root, child)) != 0 &&
3076 160 : !find_dependent_phvs_in_jointree(root, (Node *) f, varno))
3077 : {
3078 144 : f->fromlist = foreach_delete_current(f->fromlist, cell);
3079 144 : result_relids = bms_add_member(result_relids, varno);
3080 : }
3081 : }
3082 :
3083 : /*
3084 : * Clean up if we dropped any RTE_RESULT RTEs. This is a bit
3085 : * inefficient if there's more than one, but it seems better to
3086 : * optimize the support code for the single-relid case.
3087 : */
3088 135052 : if (result_relids)
3089 : {
3090 136 : int varno = -1;
3091 :
3092 280 : while ((varno = bms_next_member(result_relids, varno)) >= 0)
3093 144 : remove_result_refs(root, varno, (Node *) f);
3094 : }
3095 :
3096 : /*
3097 : * If we're not at the top of the jointree, it's valid to simplify a
3098 : * degenerate FromExpr into its single child. (At the top, we must
3099 : * keep the FromExpr since Query.jointree is required to point to a
3100 : * FromExpr.)
3101 : */
3102 135052 : if (f != root->parse->jointree &&
3103 376 : f->quals == NULL &&
3104 30 : list_length(f->fromlist) == 1)
3105 30 : return (Node *) linitial(f->fromlist);
3106 : }
3107 694 : else if (IsA(jtnode, JoinExpr))
3108 : {
3109 694 : JoinExpr *j = (JoinExpr *) jtnode;
3110 : int varno;
3111 :
3112 : /* First, recurse */
3113 694 : j->larg = remove_useless_results_recurse(root, j->larg);
3114 694 : j->rarg = remove_useless_results_recurse(root, j->rarg);
3115 :
3116 : /* Apply join-type-specific optimization rules */
3117 694 : switch (j->jointype)
3118 : {
3119 182 : case JOIN_INNER:
3120 :
3121 : /*
3122 : * An inner join is equivalent to a FromExpr, so if either
3123 : * side was simplified to an RTE_RESULT rel, we can replace
3124 : * the join with a FromExpr with just the other side; and if
3125 : * the qual is empty (JOIN ON TRUE) then we can omit the
3126 : * FromExpr as well.
3127 : *
3128 : * Just as in the FromExpr case, we can't simplify if the
3129 : * other input rel references any PHVs that are marked as to
3130 : * be evaluated at the RTE_RESULT rel, because we can't
3131 : * postpone their evaluation in that case. But we only have
3132 : * to check this in cases where it's syntactically legal for
3133 : * the other input to have a LATERAL reference to the
3134 : * RTE_RESULT rel. Only RHSes of inner and left joins are
3135 : * allowed to have such refs.
3136 : */
3137 182 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
3138 22 : !find_dependent_phvs_in_jointree(root, j->rarg, varno))
3139 : {
3140 22 : remove_result_refs(root, varno, j->rarg);
3141 22 : if (j->quals)
3142 : jtnode = (Node *)
3143 8 : makeFromExpr(list_make1(j->rarg), j->quals);
3144 : else
3145 14 : jtnode = j->rarg;
3146 : }
3147 160 : else if ((varno = get_result_relid(root, j->rarg)) != 0)
3148 : {
3149 76 : remove_result_refs(root, varno, j->larg);
3150 76 : if (j->quals)
3151 : jtnode = (Node *)
3152 64 : makeFromExpr(list_make1(j->larg), j->quals);
3153 : else
3154 12 : jtnode = j->larg;
3155 : }
3156 182 : break;
3157 232 : case JOIN_LEFT:
3158 :
3159 : /*
3160 : * We can simplify this case if the RHS is an RTE_RESULT, with
3161 : * two different possibilities:
3162 : *
3163 : * If the qual is empty (JOIN ON TRUE), then the join can be
3164 : * strength-reduced to a plain inner join, since each LHS row
3165 : * necessarily has exactly one join partner. So we can always
3166 : * discard the RHS, much as in the JOIN_INNER case above.
3167 : * (Again, the LHS could not contain a lateral reference to
3168 : * the RHS.)
3169 : *
3170 : * Otherwise, it's still true that each LHS row should be
3171 : * returned exactly once, and since the RHS returns no columns
3172 : * (unless there are PHVs that have to be evaluated there), we
3173 : * don't much care if it's null-extended or not. So in this
3174 : * case also, we can just ignore the qual and discard the left
3175 : * join.
3176 : */
3177 232 : if ((varno = get_result_relid(root, j->rarg)) != 0 &&
3178 40 : (j->quals == NULL ||
3179 16 : !find_dependent_phvs(root, varno)))
3180 : {
3181 24 : remove_result_refs(root, varno, j->larg);
3182 24 : jtnode = j->larg;
3183 : }
3184 232 : break;
3185 0 : case JOIN_RIGHT:
3186 : /* Mirror-image of the JOIN_LEFT case */
3187 0 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
3188 0 : (j->quals == NULL ||
3189 0 : !find_dependent_phvs(root, varno)))
3190 : {
3191 0 : remove_result_refs(root, varno, j->rarg);
3192 0 : jtnode = j->rarg;
3193 : }
3194 0 : break;
3195 268 : case JOIN_SEMI:
3196 :
3197 : /*
3198 : * We may simplify this case if the RHS is an RTE_RESULT; the
3199 : * join qual becomes effectively just a filter qual for the
3200 : * LHS, since we should either return the LHS row or not. For
3201 : * simplicity we inject the filter qual into a new FromExpr.
3202 : *
3203 : * Unlike the LEFT/RIGHT cases, we just Assert that there are
3204 : * no PHVs that need to be evaluated at the semijoin's RHS,
3205 : * since the rest of the query couldn't reference any outputs
3206 : * of the semijoin's RHS.
3207 : */
3208 268 : if ((varno = get_result_relid(root, j->rarg)) != 0)
3209 : {
3210 : Assert(!find_dependent_phvs(root, varno));
3211 8 : remove_result_refs(root, varno, j->larg);
3212 8 : if (j->quals)
3213 : jtnode = (Node *)
3214 8 : makeFromExpr(list_make1(j->larg), j->quals);
3215 : else
3216 0 : jtnode = j->larg;
3217 : }
3218 268 : break;
3219 12 : case JOIN_FULL:
3220 : case JOIN_ANTI:
3221 : /* We have no special smarts for these cases */
3222 12 : break;
3223 0 : default:
3224 0 : elog(ERROR, "unrecognized join type: %d",
3225 : (int) j->jointype);
3226 : break;
3227 : }
3228 : }
3229 : else
3230 0 : elog(ERROR, "unrecognized node type: %d",
3231 : (int) nodeTag(jtnode));
3232 271474 : return jtnode;
3233 : }
3234 :
3235 : /*
3236 : * get_result_relid
3237 : * If jtnode is a RangeTblRef for an RTE_RESULT RTE, return its relid;
3238 : * otherwise return 0.
3239 : */
3240 : static int
3241 1422 : get_result_relid(PlannerInfo *root, Node *jtnode)
3242 : {
3243 : int varno;
3244 :
3245 1422 : if (!IsA(jtnode, RangeTblRef))
3246 186 : return 0;
3247 1236 : varno = ((RangeTblRef *) jtnode)->rtindex;
3248 1236 : if (rt_fetch(varno, root->parse->rtable)->rtekind != RTE_RESULT)
3249 930 : return 0;
3250 306 : return varno;
3251 : }
3252 :
3253 : /*
3254 : * remove_result_refs
3255 : * Helper routine for dropping an unneeded RTE_RESULT RTE.
3256 : *
3257 : * This doesn't physically remove the RTE from the jointree, because that's
3258 : * more easily handled in remove_useless_results_recurse. What it does do
3259 : * is the necessary cleanup in the rest of the tree: we must adjust any PHVs
3260 : * that may reference the RTE. Be sure to call this at a point where the
3261 : * jointree is valid (no disconnected nodes).
3262 : *
3263 : * Note that we don't need to process the append_rel_list, since RTEs
3264 : * referenced directly in the jointree won't be appendrel members.
3265 : *
3266 : * varno is the RTE_RESULT's relid.
3267 : * newjtloc is the jointree location at which any PHVs referencing the
3268 : * RTE_RESULT should be evaluated instead.
3269 : */
3270 : static void
3271 274 : remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc)
3272 : {
3273 : /* Fix up PlaceHolderVars as needed */
3274 : /* If there are no PHVs anywhere, we can skip this bit */
3275 274 : if (root->glob->lastPHId != 0)
3276 : {
3277 : Relids subrelids;
3278 :
3279 60 : subrelids = get_relids_in_jointree(newjtloc, false);
3280 : Assert(!bms_is_empty(subrelids));
3281 60 : substitute_phv_relids((Node *) root->parse, varno, subrelids);
3282 60 : fix_append_rel_relids(root->append_rel_list, varno, subrelids);
3283 : }
3284 :
3285 : /*
3286 : * We also need to remove any PlanRowMark referencing the RTE, but we
3287 : * postpone that work until we return to remove_useless_result_rtes.
3288 : */
3289 274 : }
3290 :
3291 :
3292 : /*
3293 : * find_dependent_phvs - are there any PlaceHolderVars whose relids are
3294 : * exactly the given varno?
3295 : *
3296 : * find_dependent_phvs should be used when we want to see if there are
3297 : * any such PHVs anywhere in the Query. Another use-case is to see if
3298 : * a subtree of the join tree contains such PHVs; but for that, we have
3299 : * to look not only at the join tree nodes themselves but at the
3300 : * referenced RTEs. For that, use find_dependent_phvs_in_jointree.
3301 : */
3302 :
3303 : typedef struct
3304 : {
3305 : Relids relids;
3306 : int sublevels_up;
3307 : } find_dependent_phvs_context;
3308 :
3309 : static bool
3310 784 : find_dependent_phvs_walker(Node *node,
3311 : find_dependent_phvs_context *context)
3312 : {
3313 784 : if (node == NULL)
3314 192 : return false;
3315 592 : if (IsA(node, PlaceHolderVar))
3316 : {
3317 52 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
3318 :
3319 104 : if (phv->phlevelsup == context->sublevels_up &&
3320 52 : bms_equal(context->relids, phv->phrels))
3321 32 : return true;
3322 : /* fall through to examine children */
3323 : }
3324 560 : if (IsA(node, Query))
3325 : {
3326 : /* Recurse into subselects */
3327 : bool result;
3328 :
3329 32 : context->sublevels_up++;
3330 32 : result = query_tree_walker((Query *) node,
3331 : find_dependent_phvs_walker,
3332 : (void *) context, 0);
3333 32 : context->sublevels_up--;
3334 32 : return result;
3335 : }
3336 : /* Shouldn't need to handle planner auxiliary nodes here */
3337 : Assert(!IsA(node, SpecialJoinInfo));
3338 : Assert(!IsA(node, AppendRelInfo));
3339 : Assert(!IsA(node, PlaceHolderInfo));
3340 : Assert(!IsA(node, MinMaxAggInfo));
3341 :
3342 528 : return expression_tree_walker(node, find_dependent_phvs_walker,
3343 : (void *) context);
3344 : }
3345 :
3346 : static bool
3347 16 : find_dependent_phvs(PlannerInfo *root, int varno)
3348 : {
3349 : find_dependent_phvs_context context;
3350 :
3351 : /* If there are no PHVs anywhere, we needn't work hard */
3352 16 : if (root->glob->lastPHId == 0)
3353 0 : return false;
3354 :
3355 16 : context.relids = bms_make_singleton(varno);
3356 16 : context.sublevels_up = 0;
3357 :
3358 16 : return query_tree_walker(root->parse,
3359 : find_dependent_phvs_walker,
3360 : (void *) &context,
3361 : 0);
3362 : }
3363 :
3364 : static bool
3365 182 : find_dependent_phvs_in_jointree(PlannerInfo *root, Node *node, int varno)
3366 : {
3367 : find_dependent_phvs_context context;
3368 : Relids subrelids;
3369 : int relid;
3370 :
3371 : /* If there are no PHVs anywhere, we needn't work hard */
3372 182 : if (root->glob->lastPHId == 0)
3373 146 : return false;
3374 :
3375 36 : context.relids = bms_make_singleton(varno);
3376 36 : context.sublevels_up = 0;
3377 :
3378 : /*
3379 : * See if the jointree fragment itself contains references (in join quals)
3380 : */
3381 36 : if (find_dependent_phvs_walker(node, &context))
3382 0 : return true;
3383 :
3384 : /*
3385 : * Otherwise, identify the set of referenced RTEs (we can ignore joins,
3386 : * since they should be flattened already, so their join alias lists no
3387 : * longer matter), and tediously check each RTE. We can ignore RTEs that
3388 : * are not marked LATERAL, though, since they couldn't possibly contain
3389 : * any cross-references to other RTEs.
3390 : */
3391 36 : subrelids = get_relids_in_jointree(node, false);
3392 36 : relid = -1;
3393 80 : while ((relid = bms_next_member(subrelids, relid)) >= 0)
3394 : {
3395 60 : RangeTblEntry *rte = rt_fetch(relid, root->parse->rtable);
3396 :
3397 76 : if (rte->lateral &&
3398 16 : range_table_entry_walker(rte,
3399 : find_dependent_phvs_walker,
3400 : (void *) &context,
3401 : 0))
3402 16 : return true;
3403 : }
3404 :
3405 20 : return false;
3406 : }
3407 :
3408 : /*
3409 : * substitute_phv_relids - adjust PlaceHolderVar relid sets after pulling up
3410 : * a subquery or removing an RTE_RESULT jointree item
3411 : *
3412 : * Find any PlaceHolderVar nodes in the given tree that reference the
3413 : * pulled-up relid, and change them to reference the replacement relid(s).
3414 : *
3415 : * NOTE: although this has the form of a walker, we cheat and modify the
3416 : * nodes in-place. This should be OK since the tree was copied by
3417 : * pullup_replace_vars earlier. Avoid scribbling on the original values of
3418 : * the bitmapsets, though, because expression_tree_mutator doesn't copy those.
3419 : */
3420 :
3421 : typedef struct
3422 : {
3423 : int varno;
3424 : int sublevels_up;
3425 : Relids subrelids;
3426 : } substitute_phv_relids_context;
3427 :
3428 : static bool
3429 1089672 : substitute_phv_relids_walker(Node *node,
3430 : substitute_phv_relids_context *context)
3431 : {
3432 1089672 : if (node == NULL)
3433 423340 : return false;
3434 666332 : if (IsA(node, PlaceHolderVar))
3435 : {
3436 2964 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
3437 :
3438 5904 : if (phv->phlevelsup == context->sublevels_up &&
3439 2940 : bms_is_member(context->varno, phv->phrels))
3440 : {
3441 3892 : phv->phrels = bms_union(phv->phrels,
3442 1946 : context->subrelids);
3443 1946 : phv->phrels = bms_del_member(phv->phrels,
3444 : context->varno);
3445 : /* Assert we haven't broken the PHV */
3446 : Assert(!bms_is_empty(phv->phrels));
3447 : }
3448 : /* fall through to examine children */
3449 : }
3450 666332 : if (IsA(node, Query))
3451 : {
3452 : /* Recurse into subselects */
3453 : bool result;
3454 :
3455 26970 : context->sublevels_up++;
3456 26970 : result = query_tree_walker((Query *) node,
3457 : substitute_phv_relids_walker,
3458 : (void *) context, 0);
3459 26970 : context->sublevels_up--;
3460 26970 : return result;
3461 : }
3462 : /* Shouldn't need to handle planner auxiliary nodes here */
3463 : Assert(!IsA(node, SpecialJoinInfo));
3464 : Assert(!IsA(node, AppendRelInfo));
3465 : Assert(!IsA(node, PlaceHolderInfo));
3466 : Assert(!IsA(node, MinMaxAggInfo));
3467 :
3468 639362 : return expression_tree_walker(node, substitute_phv_relids_walker,
3469 : (void *) context);
3470 : }
3471 :
3472 : static void
3473 10826 : substitute_phv_relids(Node *node, int varno, Relids subrelids)
3474 : {
3475 : substitute_phv_relids_context context;
3476 :
3477 10826 : context.varno = varno;
3478 10826 : context.sublevels_up = 0;
3479 10826 : context.subrelids = subrelids;
3480 :
3481 : /*
3482 : * Must be prepared to start with a Query or a bare expression tree.
3483 : */
3484 10826 : query_or_expression_tree_walker(node,
3485 : substitute_phv_relids_walker,
3486 : (void *) &context,
3487 : 0);
3488 10826 : }
3489 :
3490 : /*
3491 : * fix_append_rel_relids: update RT-index fields of AppendRelInfo nodes
3492 : *
3493 : * When we pull up a subquery, any AppendRelInfo references to the subquery's
3494 : * RT index have to be replaced by the substituted relid (and there had better
3495 : * be only one). We also need to apply substitute_phv_relids to their
3496 : * translated_vars lists, since those might contain PlaceHolderVars.
3497 : *
3498 : * We assume we may modify the AppendRelInfo nodes in-place.
3499 : */
3500 : static void
3501 7930 : fix_append_rel_relids(List *append_rel_list, int varno, Relids subrelids)
3502 : {
3503 : ListCell *l;
3504 7930 : int subvarno = -1;
3505 :
3506 : /*
3507 : * We only want to extract the member relid once, but we mustn't fail
3508 : * immediately if there are multiple members; it could be that none of the
3509 : * AppendRelInfo nodes refer to it. So compute it on first use. Note that
3510 : * bms_singleton_member will complain if set is not singleton.
3511 : */
3512 10826 : foreach(l, append_rel_list)
3513 : {
3514 2896 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
3515 :
3516 : /* The parent_relid shouldn't ever be a pullup target */
3517 : Assert(appinfo->parent_relid != varno);
3518 :
3519 2896 : if (appinfo->child_relid == varno)
3520 : {
3521 1578 : if (subvarno < 0)
3522 1578 : subvarno = bms_singleton_member(subrelids);
3523 1578 : appinfo->child_relid = subvarno;
3524 : }
3525 :
3526 : /* Also fix up any PHVs in its translated vars */
3527 2896 : substitute_phv_relids((Node *) appinfo->translated_vars,
3528 : varno, subrelids);
3529 : }
3530 7930 : }
3531 :
3532 : /*
3533 : * get_relids_in_jointree: get set of RT indexes present in a jointree
3534 : *
3535 : * If include_joins is true, join RT indexes are included; if false,
3536 : * only base rels are included.
3537 : */
3538 : Relids
3539 75412 : get_relids_in_jointree(Node *jtnode, bool include_joins)
3540 : {
3541 75412 : Relids result = NULL;
3542 :
3543 75412 : if (jtnode == NULL)
3544 0 : return result;
3545 75412 : if (IsA(jtnode, RangeTblRef))
3546 : {
3547 38184 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3548 :
3549 38184 : result = bms_make_singleton(varno);
3550 : }
3551 37228 : else if (IsA(jtnode, FromExpr))
3552 : {
3553 32154 : FromExpr *f = (FromExpr *) jtnode;
3554 : ListCell *l;
3555 :
3556 65312 : foreach(l, f->fromlist)
3557 : {
3558 33158 : result = bms_join(result,
3559 33158 : get_relids_in_jointree(lfirst(l),
3560 : include_joins));
3561 : }
3562 : }
3563 5074 : else if (IsA(jtnode, JoinExpr))
3564 : {
3565 5074 : JoinExpr *j = (JoinExpr *) jtnode;
3566 :
3567 5074 : result = get_relids_in_jointree(j->larg, include_joins);
3568 5074 : result = bms_join(result,
3569 : get_relids_in_jointree(j->rarg, include_joins));
3570 5074 : if (include_joins && j->rtindex)
3571 436 : result = bms_add_member(result, j->rtindex);
3572 : }
3573 : else
3574 0 : elog(ERROR, "unrecognized node type: %d",
3575 : (int) nodeTag(jtnode));
3576 75412 : return result;
3577 : }
3578 :
3579 : /*
3580 : * get_relids_for_join: get set of base RT indexes making up a join
3581 : */
3582 : Relids
3583 0 : get_relids_for_join(Query *query, int joinrelid)
3584 : {
3585 : Node *jtnode;
3586 :
3587 0 : jtnode = find_jointree_node_for_rel((Node *) query->jointree,
3588 : joinrelid);
3589 0 : if (!jtnode)
3590 0 : elog(ERROR, "could not find join node %d", joinrelid);
3591 0 : return get_relids_in_jointree(jtnode, false);
3592 : }
3593 :
3594 : /*
3595 : * find_jointree_node_for_rel: locate jointree node for a base or join RT index
3596 : *
3597 : * Returns NULL if not found
3598 : */
3599 : static Node *
3600 0 : find_jointree_node_for_rel(Node *jtnode, int relid)
3601 : {
3602 0 : if (jtnode == NULL)
3603 0 : return NULL;
3604 0 : if (IsA(jtnode, RangeTblRef))
3605 : {
3606 0 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3607 :
3608 0 : if (relid == varno)
3609 0 : return jtnode;
3610 : }
3611 0 : else if (IsA(jtnode, FromExpr))
3612 : {
3613 0 : FromExpr *f = (FromExpr *) jtnode;
3614 : ListCell *l;
3615 :
3616 0 : foreach(l, f->fromlist)
3617 : {
3618 0 : jtnode = find_jointree_node_for_rel(lfirst(l), relid);
3619 0 : if (jtnode)
3620 0 : return jtnode;
3621 : }
3622 : }
3623 0 : else if (IsA(jtnode, JoinExpr))
3624 : {
3625 0 : JoinExpr *j = (JoinExpr *) jtnode;
3626 :
3627 0 : if (relid == j->rtindex)
3628 0 : return jtnode;
3629 0 : jtnode = find_jointree_node_for_rel(j->larg, relid);
3630 0 : if (jtnode)
3631 0 : return jtnode;
3632 0 : jtnode = find_jointree_node_for_rel(j->rarg, relid);
3633 0 : if (jtnode)
3634 0 : return jtnode;
3635 : }
3636 : else
3637 0 : elog(ERROR, "unrecognized node type: %d",
3638 : (int) nodeTag(jtnode));
3639 0 : return NULL;
3640 : }
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