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) 1996-2020, 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, Index newvarno,
84 : AppendRelInfo *appinfo);
85 : static bool is_simple_subquery(Query *subquery, RangeTblEntry *rte,
86 : JoinExpr *lowest_outer_join);
87 : static Node *pull_up_simple_values(PlannerInfo *root, Node *jtnode,
88 : RangeTblEntry *rte);
89 : static bool is_simple_values(PlannerInfo *root, RangeTblEntry *rte);
90 : static Node *pull_up_constant_function(PlannerInfo *root, Node *jtnode,
91 : RangeTblEntry *rte,
92 : JoinExpr *lowest_nulling_outer_join,
93 : AppendRelInfo *containing_appendrel);
94 : static bool is_simple_union_all(Query *subquery);
95 : static bool is_simple_union_all_recurse(Node *setOp, Query *setOpQuery,
96 : List *colTypes);
97 : static bool is_safe_append_member(Query *subquery);
98 : static bool jointree_contains_lateral_outer_refs(Node *jtnode, bool restricted,
99 : Relids safe_upper_varnos);
100 : static void perform_pullup_replace_vars(PlannerInfo *root,
101 : pullup_replace_vars_context *rvcontext,
102 : JoinExpr *lowest_nulling_outer_join,
103 : AppendRelInfo *containing_appendrel);
104 : static void replace_vars_in_jointree(Node *jtnode,
105 : pullup_replace_vars_context *context,
106 : JoinExpr *lowest_nulling_outer_join);
107 : static Node *pullup_replace_vars(Node *expr,
108 : pullup_replace_vars_context *context);
109 : static Node *pullup_replace_vars_callback(Var *var,
110 : replace_rte_variables_context *context);
111 : static Query *pullup_replace_vars_subquery(Query *query,
112 : pullup_replace_vars_context *context);
113 : static reduce_outer_joins_state *reduce_outer_joins_pass1(Node *jtnode);
114 : static void reduce_outer_joins_pass2(Node *jtnode,
115 : reduce_outer_joins_state *state,
116 : PlannerInfo *root,
117 : Relids nonnullable_rels,
118 : List *nonnullable_vars,
119 : List *forced_null_vars);
120 : static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode);
121 : static int get_result_relid(PlannerInfo *root, Node *jtnode);
122 : static void remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc);
123 : static bool find_dependent_phvs(PlannerInfo *root, int varno);
124 : static bool find_dependent_phvs_in_jointree(PlannerInfo *root,
125 : Node *node, int varno);
126 : static void substitute_phv_relids(Node *node,
127 : int varno, Relids subrelids);
128 : static void fix_append_rel_relids(List *append_rel_list, int varno,
129 : Relids subrelids);
130 : static Node *find_jointree_node_for_rel(Node *jtnode, int relid);
131 :
132 :
133 : /*
134 : * replace_empty_jointree
135 : * If the Query's jointree is empty, replace it with a dummy RTE_RESULT
136 : * relation.
137 : *
138 : * By doing this, we can avoid a bunch of corner cases that formerly existed
139 : * for SELECTs with omitted FROM clauses. An example is that a subquery
140 : * with empty jointree previously could not be pulled up, because that would
141 : * have resulted in an empty relid set, making the subquery not uniquely
142 : * identifiable for join or PlaceHolderVar processing.
143 : *
144 : * Unlike most other functions in this file, this function doesn't recurse;
145 : * we rely on other processing to invoke it on sub-queries at suitable times.
146 : */
147 : void
148 380882 : replace_empty_jointree(Query *parse)
149 : {
150 : RangeTblEntry *rte;
151 : Index rti;
152 : RangeTblRef *rtr;
153 :
154 : /* Nothing to do if jointree is already nonempty */
155 380882 : if (parse->jointree->fromlist != NIL)
156 255480 : return;
157 :
158 : /* We mustn't change it in the top level of a setop tree, either */
159 125402 : if (parse->setOperations)
160 2952 : return;
161 :
162 : /* Create suitable RTE */
163 122450 : rte = makeNode(RangeTblEntry);
164 122450 : rte->rtekind = RTE_RESULT;
165 122450 : rte->eref = makeAlias("*RESULT*", NIL);
166 :
167 : /* Add it to rangetable */
168 122450 : parse->rtable = lappend(parse->rtable, rte);
169 122450 : rti = list_length(parse->rtable);
170 :
171 : /* And jam a reference into the jointree */
172 122450 : rtr = makeNode(RangeTblRef);
173 122450 : rtr->rtindex = rti;
174 122450 : parse->jointree->fromlist = list_make1(rtr);
175 : }
176 :
177 : /*
178 : * pull_up_sublinks
179 : * Attempt to pull up ANY and EXISTS SubLinks to be treated as
180 : * semijoins or anti-semijoins.
181 : *
182 : * A clause "foo op ANY (sub-SELECT)" can be processed by pulling the
183 : * sub-SELECT up to become a rangetable entry and treating the implied
184 : * comparisons as quals of a semijoin. However, this optimization *only*
185 : * works at the top level of WHERE or a JOIN/ON clause, because we cannot
186 : * distinguish whether the ANY ought to return FALSE or NULL in cases
187 : * involving NULL inputs. Also, in an outer join's ON clause we can only
188 : * do this if the sublink is degenerate (ie, references only the nullable
189 : * side of the join). In that case it is legal to push the semijoin
190 : * down into the nullable side of the join. If the sublink references any
191 : * nonnullable-side variables then it would have to be evaluated as part
192 : * of the outer join, which makes things way too complicated.
193 : *
194 : * Under similar conditions, EXISTS and NOT EXISTS clauses can be handled
195 : * by pulling up the sub-SELECT and creating a semijoin or anti-semijoin.
196 : *
197 : * This routine searches for such clauses and does the necessary parsetree
198 : * transformations if any are found.
199 : *
200 : * This routine has to run before preprocess_expression(), so the quals
201 : * clauses are not yet reduced to implicit-AND format, and are not guaranteed
202 : * to be AND/OR-flat either. That means we need to recursively search through
203 : * explicit AND clauses. We stop as soon as we hit a non-AND item.
204 : */
205 : void
206 42698 : pull_up_sublinks(PlannerInfo *root)
207 : {
208 : Node *jtnode;
209 : Relids relids;
210 :
211 : /* Begin recursion through the jointree */
212 42698 : jtnode = pull_up_sublinks_jointree_recurse(root,
213 42698 : (Node *) root->parse->jointree,
214 : &relids);
215 :
216 : /*
217 : * root->parse->jointree must always be a FromExpr, so insert a dummy one
218 : * if we got a bare RangeTblRef or JoinExpr out of the recursion.
219 : */
220 42698 : if (IsA(jtnode, FromExpr))
221 34334 : root->parse->jointree = (FromExpr *) jtnode;
222 : else
223 8364 : root->parse->jointree = makeFromExpr(list_make1(jtnode), NULL);
224 42698 : }
225 :
226 : /*
227 : * Recurse through jointree nodes for pull_up_sublinks()
228 : *
229 : * In addition to returning the possibly-modified jointree node, we return
230 : * a relids set of the contained rels into *relids.
231 : */
232 : static Node *
233 129940 : pull_up_sublinks_jointree_recurse(PlannerInfo *root, Node *jtnode,
234 : Relids *relids)
235 : {
236 129940 : if (jtnode == NULL)
237 : {
238 0 : *relids = NULL;
239 : }
240 129940 : else if (IsA(jtnode, RangeTblRef))
241 : {
242 70082 : int varno = ((RangeTblRef *) jtnode)->rtindex;
243 :
244 70082 : *relids = bms_make_singleton(varno);
245 : /* jtnode is returned unmodified */
246 : }
247 59858 : else if (IsA(jtnode, FromExpr))
248 : {
249 42702 : FromExpr *f = (FromExpr *) jtnode;
250 42702 : List *newfromlist = NIL;
251 42702 : Relids frelids = NULL;
252 : FromExpr *newf;
253 : Node *jtlink;
254 : ListCell *l;
255 :
256 : /* First, recurse to process children and collect their relids */
257 86844 : foreach(l, f->fromlist)
258 : {
259 : Node *newchild;
260 : Relids childrelids;
261 :
262 44142 : newchild = pull_up_sublinks_jointree_recurse(root,
263 44142 : lfirst(l),
264 : &childrelids);
265 44142 : newfromlist = lappend(newfromlist, newchild);
266 44142 : frelids = bms_join(frelids, childrelids);
267 : }
268 : /* Build the replacement FromExpr; no quals yet */
269 42702 : newf = makeFromExpr(newfromlist, NULL);
270 : /* Set up a link representing the rebuilt jointree */
271 42702 : jtlink = (Node *) newf;
272 : /* Now process qual --- all children are available for use */
273 42702 : newf->quals = pull_up_sublinks_qual_recurse(root, f->quals,
274 : &jtlink, frelids,
275 : NULL, NULL);
276 :
277 : /*
278 : * Note that the result will be either newf, or a stack of JoinExprs
279 : * with newf at the base. We rely on subsequent optimization steps to
280 : * flatten this and rearrange the joins as needed.
281 : *
282 : * Although we could include the pulled-up subqueries in the returned
283 : * relids, there's no need since upper quals couldn't refer to their
284 : * outputs anyway.
285 : */
286 42702 : *relids = frelids;
287 42702 : jtnode = jtlink;
288 : }
289 17156 : else if (IsA(jtnode, JoinExpr))
290 : {
291 : JoinExpr *j;
292 : Relids leftrelids;
293 : Relids rightrelids;
294 : Node *jtlink;
295 :
296 : /*
297 : * Make a modifiable copy of join node, but don't bother copying its
298 : * subnodes (yet).
299 : */
300 17156 : j = (JoinExpr *) palloc(sizeof(JoinExpr));
301 17156 : memcpy(j, jtnode, sizeof(JoinExpr));
302 17156 : jtlink = (Node *) j;
303 :
304 : /* Recurse to process children and collect their relids */
305 17156 : j->larg = pull_up_sublinks_jointree_recurse(root, j->larg,
306 : &leftrelids);
307 17156 : j->rarg = pull_up_sublinks_jointree_recurse(root, j->rarg,
308 : &rightrelids);
309 :
310 : /*
311 : * Now process qual, showing appropriate child relids as available,
312 : * and attach any pulled-up jointree items at the right place. In the
313 : * inner-join case we put new JoinExprs above the existing one (much
314 : * as for a FromExpr-style join). In outer-join cases the new
315 : * JoinExprs must go into the nullable side of the outer join. The
316 : * point of the available_rels machinations is to ensure that we only
317 : * pull up quals for which that's okay.
318 : *
319 : * We don't expect to see any pre-existing JOIN_SEMI or JOIN_ANTI
320 : * nodes here.
321 : */
322 17156 : switch (j->jointype)
323 : {
324 4200 : case JOIN_INNER:
325 4200 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
326 : &jtlink,
327 : bms_union(leftrelids,
328 : rightrelids),
329 : NULL, NULL);
330 4200 : break;
331 12956 : case JOIN_LEFT:
332 12956 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
333 : &j->rarg,
334 : rightrelids,
335 : NULL, NULL);
336 12956 : break;
337 0 : case JOIN_FULL:
338 : /* can't do anything with full-join quals */
339 0 : break;
340 0 : case JOIN_RIGHT:
341 0 : j->quals = pull_up_sublinks_qual_recurse(root, j->quals,
342 : &j->larg,
343 : leftrelids,
344 : NULL, NULL);
345 0 : break;
346 0 : default:
347 0 : elog(ERROR, "unrecognized join type: %d",
348 : (int) j->jointype);
349 : break;
350 : }
351 :
352 : /*
353 : * Although we could include the pulled-up subqueries in the returned
354 : * relids, there's no need since upper quals couldn't refer to their
355 : * outputs anyway. But we *do* need to include the join's own rtindex
356 : * because we haven't yet collapsed join alias variables, so upper
357 : * levels would mistakenly think they couldn't use references to this
358 : * join.
359 : */
360 17156 : *relids = bms_join(leftrelids, rightrelids);
361 17156 : if (j->rtindex)
362 17156 : *relids = bms_add_member(*relids, j->rtindex);
363 17156 : jtnode = jtlink;
364 : }
365 : else
366 0 : elog(ERROR, "unrecognized node type: %d",
367 : (int) nodeTag(jtnode));
368 129940 : return jtnode;
369 : }
370 :
371 : /*
372 : * Recurse through top-level qual nodes for pull_up_sublinks()
373 : *
374 : * jtlink1 points to the link in the jointree where any new JoinExprs should
375 : * be inserted if they reference available_rels1 (i.e., available_rels1
376 : * denotes the relations present underneath jtlink1). Optionally, jtlink2 can
377 : * point to a second link where new JoinExprs should be inserted if they
378 : * reference available_rels2 (pass NULL for both those arguments if not used).
379 : * Note that SubLinks referencing both sets of variables cannot be optimized.
380 : * If we find multiple pull-up-able SubLinks, they'll get stacked onto jtlink1
381 : * and/or jtlink2 in the order we encounter them. We rely on subsequent
382 : * optimization to rearrange the stack if appropriate.
383 : *
384 : * Returns the replacement qual node, or NULL if the qual should be removed.
385 : */
386 : static Node *
387 118190 : pull_up_sublinks_qual_recurse(PlannerInfo *root, Node *node,
388 : Node **jtlink1, Relids available_rels1,
389 : Node **jtlink2, Relids available_rels2)
390 : {
391 118190 : if (node == NULL)
392 6700 : return NULL;
393 111490 : if (IsA(node, SubLink))
394 : {
395 928 : SubLink *sublink = (SubLink *) node;
396 : JoinExpr *j;
397 : Relids child_rels;
398 :
399 : /* Is it a convertible ANY or EXISTS clause? */
400 928 : if (sublink->subLinkType == ANY_SUBLINK)
401 : {
402 684 : if ((j = convert_ANY_sublink_to_join(root, sublink,
403 : available_rels1)) != NULL)
404 : {
405 : /* Yes; insert the new join node into the join tree */
406 612 : j->larg = *jtlink1;
407 612 : *jtlink1 = (Node *) j;
408 : /* Recursively process pulled-up jointree nodes */
409 612 : j->rarg = pull_up_sublinks_jointree_recurse(root,
410 : j->rarg,
411 : &child_rels);
412 :
413 : /*
414 : * Now recursively process the pulled-up quals. Any inserted
415 : * joins can get stacked onto either j->larg or j->rarg,
416 : * depending on which rels they reference.
417 : */
418 612 : j->quals = pull_up_sublinks_qual_recurse(root,
419 : j->quals,
420 : &j->larg,
421 : available_rels1,
422 : &j->rarg,
423 : child_rels);
424 : /* Return NULL representing constant TRUE */
425 612 : return NULL;
426 : }
427 72 : if (available_rels2 != NULL &&
428 0 : (j = convert_ANY_sublink_to_join(root, sublink,
429 : available_rels2)) != NULL)
430 : {
431 : /* Yes; insert the new join node into the join tree */
432 0 : j->larg = *jtlink2;
433 0 : *jtlink2 = (Node *) j;
434 : /* Recursively process pulled-up jointree nodes */
435 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
436 : j->rarg,
437 : &child_rels);
438 :
439 : /*
440 : * Now recursively process the pulled-up quals. Any inserted
441 : * joins can get stacked onto either j->larg or j->rarg,
442 : * depending on which rels they reference.
443 : */
444 0 : j->quals = pull_up_sublinks_qual_recurse(root,
445 : j->quals,
446 : &j->larg,
447 : available_rels2,
448 : &j->rarg,
449 : child_rels);
450 : /* Return NULL representing constant TRUE */
451 0 : return NULL;
452 : }
453 : }
454 244 : else if (sublink->subLinkType == EXISTS_SUBLINK)
455 : {
456 216 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, false,
457 : available_rels1)) != NULL)
458 : {
459 : /* Yes; insert the new join node into the join tree */
460 170 : j->larg = *jtlink1;
461 170 : *jtlink1 = (Node *) j;
462 : /* Recursively process pulled-up jointree nodes */
463 170 : j->rarg = pull_up_sublinks_jointree_recurse(root,
464 : j->rarg,
465 : &child_rels);
466 :
467 : /*
468 : * Now recursively process the pulled-up quals. Any inserted
469 : * joins can get stacked onto either j->larg or j->rarg,
470 : * depending on which rels they reference.
471 : */
472 170 : j->quals = pull_up_sublinks_qual_recurse(root,
473 : j->quals,
474 : &j->larg,
475 : available_rels1,
476 : &j->rarg,
477 : child_rels);
478 : /* Return NULL representing constant TRUE */
479 170 : return NULL;
480 : }
481 46 : if (available_rels2 != NULL &&
482 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, false,
483 : available_rels2)) != NULL)
484 : {
485 : /* Yes; insert the new join node into the join tree */
486 0 : j->larg = *jtlink2;
487 0 : *jtlink2 = (Node *) j;
488 : /* Recursively process pulled-up jointree nodes */
489 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
490 : j->rarg,
491 : &child_rels);
492 :
493 : /*
494 : * Now recursively process the pulled-up quals. Any inserted
495 : * joins can get stacked onto either j->larg or j->rarg,
496 : * depending on which rels they reference.
497 : */
498 0 : j->quals = pull_up_sublinks_qual_recurse(root,
499 : j->quals,
500 : &j->larg,
501 : available_rels2,
502 : &j->rarg,
503 : child_rels);
504 : /* Return NULL representing constant TRUE */
505 0 : return NULL;
506 : }
507 : }
508 : /* Else return it unmodified */
509 146 : return node;
510 : }
511 110562 : if (is_notclause(node))
512 : {
513 : /* If the immediate argument of NOT is EXISTS, try to convert */
514 10384 : SubLink *sublink = (SubLink *) get_notclausearg((Expr *) node);
515 : JoinExpr *j;
516 : Relids child_rels;
517 :
518 10384 : if (sublink && IsA(sublink, SubLink))
519 : {
520 8070 : if (sublink->subLinkType == EXISTS_SUBLINK)
521 : {
522 8022 : if ((j = convert_EXISTS_sublink_to_join(root, sublink, true,
523 : available_rels1)) != NULL)
524 : {
525 : /* Yes; insert the new join node into the join tree */
526 8006 : j->larg = *jtlink1;
527 8006 : *jtlink1 = (Node *) j;
528 : /* Recursively process pulled-up jointree nodes */
529 8006 : j->rarg = pull_up_sublinks_jointree_recurse(root,
530 : j->rarg,
531 : &child_rels);
532 :
533 : /*
534 : * Now recursively process the pulled-up quals. Because
535 : * we are underneath a NOT, we can't pull up sublinks that
536 : * reference the left-hand stuff, but it's still okay to
537 : * pull up sublinks referencing j->rarg.
538 : */
539 8006 : j->quals = pull_up_sublinks_qual_recurse(root,
540 : j->quals,
541 : &j->rarg,
542 : child_rels,
543 : NULL, NULL);
544 : /* Return NULL representing constant TRUE */
545 8006 : return NULL;
546 : }
547 16 : if (available_rels2 != NULL &&
548 0 : (j = convert_EXISTS_sublink_to_join(root, sublink, true,
549 : available_rels2)) != NULL)
550 : {
551 : /* Yes; insert the new join node into the join tree */
552 0 : j->larg = *jtlink2;
553 0 : *jtlink2 = (Node *) j;
554 : /* Recursively process pulled-up jointree nodes */
555 0 : j->rarg = pull_up_sublinks_jointree_recurse(root,
556 : j->rarg,
557 : &child_rels);
558 :
559 : /*
560 : * Now recursively process the pulled-up quals. Because
561 : * we are underneath a NOT, we can't pull up sublinks that
562 : * reference the left-hand stuff, but it's still okay to
563 : * pull up sublinks referencing j->rarg.
564 : */
565 0 : j->quals = pull_up_sublinks_qual_recurse(root,
566 : j->quals,
567 : &j->rarg,
568 : child_rels,
569 : NULL, NULL);
570 : /* Return NULL representing constant TRUE */
571 0 : return NULL;
572 : }
573 : }
574 : }
575 : /* Else return it unmodified */
576 2378 : return node;
577 : }
578 100178 : if (is_andclause(node))
579 : {
580 : /* Recurse into AND clause */
581 19332 : List *newclauses = NIL;
582 : ListCell *l;
583 :
584 68876 : foreach(l, ((BoolExpr *) node)->args)
585 : {
586 49544 : Node *oldclause = (Node *) lfirst(l);
587 : Node *newclause;
588 :
589 49544 : newclause = pull_up_sublinks_qual_recurse(root,
590 : oldclause,
591 : jtlink1,
592 : available_rels1,
593 : jtlink2,
594 : available_rels2);
595 49544 : if (newclause)
596 47184 : newclauses = lappend(newclauses, newclause);
597 : }
598 : /* We might have got back fewer clauses than we started with */
599 19332 : if (newclauses == NIL)
600 396 : return NULL;
601 18936 : else if (list_length(newclauses) == 1)
602 1014 : return (Node *) linitial(newclauses);
603 : else
604 17922 : return (Node *) make_andclause(newclauses);
605 : }
606 : /* Stop if not an AND */
607 80846 : return node;
608 : }
609 :
610 : /*
611 : * preprocess_function_rtes
612 : * Constant-simplify any FUNCTION RTEs in the FROM clause, and then
613 : * attempt to "inline" any that are set-returning functions.
614 : *
615 : * If an RTE_FUNCTION rtable entry invokes a set-returning function that
616 : * contains just a simple SELECT, we can convert the rtable entry to an
617 : * RTE_SUBQUERY entry exposing the SELECT directly. This is especially
618 : * useful if the subquery can then be "pulled up" for further optimization,
619 : * but we do it even if not, to reduce executor overhead.
620 : *
621 : * This has to be done before we have started to do any optimization of
622 : * subqueries, else any such steps wouldn't get applied to subqueries
623 : * obtained via inlining. However, we do it after pull_up_sublinks
624 : * so that we can inline any functions used in SubLink subselects.
625 : *
626 : * The reason for applying const-simplification at this stage is that
627 : * (a) we'd need to do it anyway to inline a SRF, and (b) by doing it now,
628 : * we can be sure that pull_up_constant_function() will see constants
629 : * if there are constants to be seen. This approach also guarantees
630 : * that every FUNCTION RTE has been const-simplified, allowing planner.c's
631 : * preprocess_expression() to skip doing it again.
632 : *
633 : * Like most of the planner, this feels free to scribble on its input data
634 : * structure.
635 : */
636 : void
637 372706 : preprocess_function_rtes(PlannerInfo *root)
638 : {
639 : ListCell *rt;
640 :
641 979406 : foreach(rt, root->parse->rtable)
642 : {
643 606704 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
644 :
645 606704 : if (rte->rtekind == RTE_FUNCTION)
646 : {
647 : Query *funcquery;
648 :
649 : /* Apply const-simplification */
650 31874 : rte->functions = (List *)
651 31874 : eval_const_expressions(root, (Node *) rte->functions);
652 :
653 : /* Check safety of expansion, and expand if possible */
654 31874 : funcquery = inline_set_returning_function(root, rte);
655 31870 : if (funcquery)
656 : {
657 : /* Successful expansion, convert the RTE to a subquery */
658 76 : rte->rtekind = RTE_SUBQUERY;
659 76 : rte->subquery = funcquery;
660 76 : rte->security_barrier = false;
661 : /* Clear fields that should not be set in a subquery RTE */
662 76 : rte->functions = NIL;
663 76 : rte->funcordinality = false;
664 : }
665 : }
666 : }
667 372702 : }
668 :
669 : /*
670 : * pull_up_subqueries
671 : * Look for subqueries in the rangetable that can be pulled up into
672 : * the parent query. If the subquery has no special features like
673 : * grouping/aggregation then we can merge it into the parent's jointree.
674 : * Also, subqueries that are simple UNION ALL structures can be
675 : * converted into "append relations".
676 : */
677 : void
678 372702 : pull_up_subqueries(PlannerInfo *root)
679 : {
680 : /* Top level of jointree must always be a FromExpr */
681 : Assert(IsA(root->parse->jointree, FromExpr));
682 : /* Recursion starts with no containing join nor appendrel */
683 745400 : root->parse->jointree = (FromExpr *)
684 372702 : pull_up_subqueries_recurse(root, (Node *) root->parse->jointree,
685 : NULL, NULL, NULL);
686 : /* We should still have a FromExpr */
687 : Assert(IsA(root->parse->jointree, FromExpr));
688 372698 : }
689 :
690 : /*
691 : * pull_up_subqueries_recurse
692 : * Recursive guts of pull_up_subqueries.
693 : *
694 : * This recursively processes the jointree and returns a modified jointree.
695 : *
696 : * If this jointree node is within either side of an outer join, then
697 : * lowest_outer_join references the lowest such JoinExpr node; otherwise
698 : * it is NULL. We use this to constrain the effects of LATERAL subqueries.
699 : *
700 : * If this jointree node is within the nullable side of an outer join, then
701 : * lowest_nulling_outer_join references the lowest such JoinExpr node;
702 : * otherwise it is NULL. This forces use of the PlaceHolderVar mechanism for
703 : * references to non-nullable targetlist items, but only for references above
704 : * that join.
705 : *
706 : * If we are looking at a member subquery of an append relation,
707 : * containing_appendrel describes that relation; else it is NULL.
708 : * This forces use of the PlaceHolderVar mechanism for all non-Var targetlist
709 : * items, and puts some additional restrictions on what can be pulled up.
710 : *
711 : * A tricky aspect of this code is that if we pull up a subquery we have
712 : * to replace Vars that reference the subquery's outputs throughout the
713 : * parent query, including quals attached to jointree nodes above the one
714 : * we are currently processing! We handle this by being careful to maintain
715 : * validity of the jointree structure while recursing, in the following sense:
716 : * whenever we recurse, all qual expressions in the tree must be reachable
717 : * from the top level, in case the recursive call needs to modify them.
718 : *
719 : * Notice also that we can't turn pullup_replace_vars loose on the whole
720 : * jointree, because it'd return a mutated copy of the tree; we have to
721 : * invoke it just on the quals, instead. This behavior is what makes it
722 : * reasonable to pass lowest_outer_join and lowest_nulling_outer_join as
723 : * pointers rather than some more-indirect way of identifying the lowest
724 : * OJs. Likewise, we don't replace append_rel_list members but only their
725 : * substructure, so the containing_appendrel reference is safe to use.
726 : */
727 : static Node *
728 896602 : pull_up_subqueries_recurse(PlannerInfo *root, Node *jtnode,
729 : JoinExpr *lowest_outer_join,
730 : JoinExpr *lowest_nulling_outer_join,
731 : AppendRelInfo *containing_appendrel)
732 : {
733 : Assert(jtnode != NULL);
734 896602 : if (IsA(jtnode, RangeTblRef))
735 : {
736 453262 : int varno = ((RangeTblRef *) jtnode)->rtindex;
737 453262 : RangeTblEntry *rte = rt_fetch(varno, root->parse->rtable);
738 :
739 : /*
740 : * Is this a subquery RTE, and if so, is the subquery simple enough to
741 : * pull up?
742 : *
743 : * If we are looking at an append-relation member, we can't pull it up
744 : * unless is_safe_append_member says so.
745 : */
746 502494 : if (rte->rtekind == RTE_SUBQUERY &&
747 93930 : is_simple_subquery(rte->subquery, rte, lowest_outer_join) &&
748 4232 : (containing_appendrel == NULL ||
749 4232 : is_safe_append_member(rte->subquery)))
750 42028 : return pull_up_simple_subquery(root, jtnode, rte,
751 : lowest_outer_join,
752 : lowest_nulling_outer_join,
753 : containing_appendrel);
754 :
755 : /*
756 : * Alternatively, is it a simple UNION ALL subquery? If so, flatten
757 : * into an "append relation".
758 : *
759 : * It's safe to do this regardless of whether this query is itself an
760 : * appendrel member. (If you're thinking we should try to flatten the
761 : * two levels of appendrel together, you're right; but we handle that
762 : * in set_append_rel_pathlist, not here.)
763 : */
764 418438 : if (rte->rtekind == RTE_SUBQUERY &&
765 7204 : is_simple_union_all(rte->subquery))
766 774 : return pull_up_simple_union_all(root, jtnode, rte);
767 :
768 : /*
769 : * Or perhaps it's a simple VALUES RTE?
770 : *
771 : * We don't allow VALUES pullup below an outer join nor into an
772 : * appendrel (such cases are impossible anyway at the moment).
773 : */
774 410460 : if (rte->rtekind == RTE_VALUES &&
775 4960 : lowest_outer_join == NULL &&
776 4960 : containing_appendrel == NULL &&
777 4960 : is_simple_values(root, rte))
778 602 : return pull_up_simple_values(root, jtnode, rte);
779 :
780 : /*
781 : * Or perhaps it's a FUNCTION RTE that we could inline?
782 : */
783 409858 : if (rte->rtekind == RTE_FUNCTION)
784 31794 : return pull_up_constant_function(root, jtnode, rte,
785 : lowest_nulling_outer_join,
786 : containing_appendrel);
787 :
788 : /* Otherwise, do nothing at this node. */
789 : }
790 443340 : else if (IsA(jtnode, FromExpr))
791 : {
792 381070 : FromExpr *f = (FromExpr *) jtnode;
793 : ListCell *l;
794 :
795 : Assert(containing_appendrel == NULL);
796 : /* Recursively transform all the child nodes */
797 775866 : foreach(l, f->fromlist)
798 : {
799 394800 : lfirst(l) = pull_up_subqueries_recurse(root, lfirst(l),
800 : lowest_outer_join,
801 : lowest_nulling_outer_join,
802 : NULL);
803 : }
804 : }
805 62270 : else if (IsA(jtnode, JoinExpr))
806 : {
807 62270 : JoinExpr *j = (JoinExpr *) jtnode;
808 :
809 : Assert(containing_appendrel == NULL);
810 : /* Recurse, being careful to tell myself when inside outer join */
811 62270 : switch (j->jointype)
812 : {
813 17010 : case JOIN_INNER:
814 17010 : j->larg = pull_up_subqueries_recurse(root, j->larg,
815 : lowest_outer_join,
816 : lowest_nulling_outer_join,
817 : NULL);
818 17010 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
819 : lowest_outer_join,
820 : lowest_nulling_outer_join,
821 : NULL);
822 17010 : break;
823 44498 : case JOIN_LEFT:
824 : case JOIN_SEMI:
825 : case JOIN_ANTI:
826 44498 : j->larg = pull_up_subqueries_recurse(root, j->larg,
827 : j,
828 : lowest_nulling_outer_join,
829 : NULL);
830 44498 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
831 : j,
832 : j,
833 : NULL);
834 44498 : break;
835 590 : case JOIN_FULL:
836 590 : j->larg = pull_up_subqueries_recurse(root, j->larg,
837 : j,
838 : j,
839 : NULL);
840 590 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
841 : j,
842 : j,
843 : NULL);
844 590 : break;
845 172 : case JOIN_RIGHT:
846 172 : j->larg = pull_up_subqueries_recurse(root, j->larg,
847 : j,
848 : j,
849 : NULL);
850 172 : j->rarg = pull_up_subqueries_recurse(root, j->rarg,
851 : j,
852 : lowest_nulling_outer_join,
853 : NULL);
854 172 : break;
855 0 : default:
856 0 : elog(ERROR, "unrecognized join type: %d",
857 : (int) j->jointype);
858 : break;
859 : }
860 : }
861 : else
862 0 : elog(ERROR, "unrecognized node type: %d",
863 : (int) nodeTag(jtnode));
864 821400 : return jtnode;
865 : }
866 :
867 : /*
868 : * pull_up_simple_subquery
869 : * Attempt to pull up a single simple subquery.
870 : *
871 : * jtnode is a RangeTblRef that has been tentatively identified as a simple
872 : * subquery by pull_up_subqueries. We return the replacement jointree node,
873 : * or jtnode itself if we determine that the subquery can't be pulled up
874 : * after all.
875 : *
876 : * rte is the RangeTblEntry referenced by jtnode. Remaining parameters are
877 : * as for pull_up_subqueries_recurse.
878 : */
879 : static Node *
880 42028 : pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
881 : JoinExpr *lowest_outer_join,
882 : JoinExpr *lowest_nulling_outer_join,
883 : AppendRelInfo *containing_appendrel)
884 : {
885 42028 : Query *parse = root->parse;
886 42028 : int varno = ((RangeTblRef *) jtnode)->rtindex;
887 : Query *subquery;
888 : PlannerInfo *subroot;
889 : int rtoffset;
890 : pullup_replace_vars_context rvcontext;
891 : ListCell *lc;
892 :
893 : /*
894 : * Need a modifiable copy of the subquery to hack on. Even if we didn't
895 : * sometimes choose not to pull up below, we must do this to avoid
896 : * problems if the same subquery is referenced from multiple jointree
897 : * items (which can't happen normally, but might after rule rewriting).
898 : */
899 42028 : subquery = copyObject(rte->subquery);
900 :
901 : /*
902 : * Create a PlannerInfo data structure for this subquery.
903 : *
904 : * NOTE: the next few steps should match the first processing in
905 : * subquery_planner(). Can we refactor to avoid code duplication, or
906 : * would that just make things uglier?
907 : */
908 42028 : subroot = makeNode(PlannerInfo);
909 42028 : subroot->parse = subquery;
910 42028 : subroot->glob = root->glob;
911 42028 : subroot->query_level = root->query_level;
912 42028 : subroot->parent_root = root->parent_root;
913 42028 : subroot->plan_params = NIL;
914 42028 : subroot->outer_params = NULL;
915 42028 : subroot->planner_cxt = CurrentMemoryContext;
916 42028 : subroot->init_plans = NIL;
917 42028 : subroot->cte_plan_ids = NIL;
918 42028 : subroot->multiexpr_params = NIL;
919 42028 : subroot->eq_classes = NIL;
920 42028 : subroot->ec_merging_done = false;
921 42028 : subroot->append_rel_list = NIL;
922 42028 : subroot->rowMarks = NIL;
923 42028 : memset(subroot->upper_rels, 0, sizeof(subroot->upper_rels));
924 42028 : memset(subroot->upper_targets, 0, sizeof(subroot->upper_targets));
925 42028 : subroot->processed_tlist = NIL;
926 42028 : subroot->grouping_map = NULL;
927 42028 : subroot->minmax_aggs = NIL;
928 42028 : subroot->qual_security_level = 0;
929 42028 : subroot->inhTargetKind = INHKIND_NONE;
930 42028 : subroot->hasRecursion = false;
931 42028 : subroot->wt_param_id = -1;
932 42028 : subroot->non_recursive_path = NULL;
933 :
934 : /* No CTEs to worry about */
935 : Assert(subquery->cteList == NIL);
936 :
937 : /*
938 : * If the FROM clause is empty, replace it with a dummy RTE_RESULT RTE, so
939 : * that we don't need so many special cases to deal with that situation.
940 : */
941 42028 : replace_empty_jointree(subquery);
942 :
943 : /*
944 : * Pull up any SubLinks within the subquery's quals, so that we don't
945 : * leave unoptimized SubLinks behind.
946 : */
947 42028 : if (subquery->hasSubLinks)
948 10536 : pull_up_sublinks(subroot);
949 :
950 : /*
951 : * Similarly, preprocess its function RTEs to inline any set-returning
952 : * functions in its rangetable.
953 : */
954 42028 : preprocess_function_rtes(subroot);
955 :
956 : /*
957 : * Recursively pull up the subquery's subqueries, so that
958 : * pull_up_subqueries' processing is complete for its jointree and
959 : * rangetable.
960 : *
961 : * Note: it's okay that the subquery's recursion starts with NULL for
962 : * containing-join info, even if we are within an outer join in the upper
963 : * query; the lower query starts with a clean slate for outer-join
964 : * semantics. Likewise, we needn't pass down appendrel state.
965 : */
966 42028 : pull_up_subqueries(subroot);
967 :
968 : /*
969 : * Now we must recheck whether the subquery is still simple enough to pull
970 : * up. If not, abandon processing it.
971 : *
972 : * We don't really need to recheck all the conditions involved, but it's
973 : * easier just to keep this "if" looking the same as the one in
974 : * pull_up_subqueries_recurse.
975 : */
976 43554 : if (is_simple_subquery(subquery, rte, lowest_outer_join) &&
977 1562 : (containing_appendrel == NULL || is_safe_append_member(subquery)))
978 : {
979 : /* good to go */
980 : }
981 : else
982 : {
983 : /*
984 : * Give up, return unmodified RangeTblRef.
985 : *
986 : * Note: The work we just did will be redone when the subquery gets
987 : * planned on its own. Perhaps we could avoid that by storing the
988 : * modified subquery back into the rangetable, but I'm not gonna risk
989 : * it now.
990 : */
991 36 : return jtnode;
992 : }
993 :
994 : /*
995 : * We must flatten any join alias Vars in the subquery's targetlist,
996 : * because pulling up the subquery's subqueries might have changed their
997 : * expansions into arbitrary expressions, which could affect
998 : * pullup_replace_vars' decisions about whether PlaceHolderVar wrappers
999 : * are needed for tlist entries. (Likely it'd be better to do
1000 : * flatten_join_alias_vars on the whole query tree at some earlier stage,
1001 : * maybe even in the rewriter; but for now let's just fix this case here.)
1002 : */
1003 41992 : subquery->targetList = (List *)
1004 41992 : flatten_join_alias_vars(subroot->parse, (Node *) subquery->targetList);
1005 :
1006 : /*
1007 : * Adjust level-0 varnos in subquery so that we can append its rangetable
1008 : * to upper query's. We have to fix the subquery's append_rel_list as
1009 : * well.
1010 : */
1011 41992 : rtoffset = list_length(parse->rtable);
1012 41992 : OffsetVarNodes((Node *) subquery, rtoffset, 0);
1013 41992 : OffsetVarNodes((Node *) subroot->append_rel_list, rtoffset, 0);
1014 :
1015 : /*
1016 : * Upper-level vars in subquery are now one level closer to their parent
1017 : * than before.
1018 : */
1019 41992 : IncrementVarSublevelsUp((Node *) subquery, -1, 1);
1020 41992 : IncrementVarSublevelsUp((Node *) subroot->append_rel_list, -1, 1);
1021 :
1022 : /*
1023 : * The subquery's targetlist items are now in the appropriate form to
1024 : * insert into the top query, except that we may need to wrap them in
1025 : * PlaceHolderVars. Set up required context data for pullup_replace_vars.
1026 : */
1027 41992 : rvcontext.root = root;
1028 41992 : rvcontext.targetlist = subquery->targetList;
1029 41992 : rvcontext.target_rte = rte;
1030 41992 : if (rte->lateral)
1031 332 : rvcontext.relids = get_relids_in_jointree((Node *) subquery->jointree,
1032 : true);
1033 : else /* won't need relids */
1034 41660 : rvcontext.relids = NULL;
1035 41992 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1036 41992 : rvcontext.varno = varno;
1037 : /* these flags will be set below, if needed */
1038 41992 : rvcontext.need_phvs = false;
1039 41992 : rvcontext.wrap_non_vars = false;
1040 : /* initialize cache array with indexes 0 .. length(tlist) */
1041 41992 : rvcontext.rv_cache = palloc0((list_length(subquery->targetList) + 1) *
1042 : sizeof(Node *));
1043 :
1044 : /*
1045 : * If we are under an outer join then non-nullable items and lateral
1046 : * references may have to be turned into PlaceHolderVars.
1047 : */
1048 41992 : if (lowest_nulling_outer_join != NULL)
1049 1198 : rvcontext.need_phvs = true;
1050 :
1051 : /*
1052 : * If we are dealing with an appendrel member then anything that's not a
1053 : * simple Var has to be turned into a PlaceHolderVar. We force this to
1054 : * ensure that what we pull up doesn't get merged into a surrounding
1055 : * expression during later processing and then fail to match the
1056 : * expression actually available from the appendrel.
1057 : */
1058 41992 : if (containing_appendrel != NULL)
1059 : {
1060 1526 : rvcontext.need_phvs = true;
1061 1526 : rvcontext.wrap_non_vars = true;
1062 : }
1063 :
1064 : /*
1065 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1066 : * anything that's not a simple Var. Again, this ensures that expressions
1067 : * retain their separate identity so that they will match grouping set
1068 : * columns when appropriate. (It'd be sufficient to wrap values used in
1069 : * grouping set columns, and do so only in non-aggregated portions of the
1070 : * tlist and havingQual, but that would require a lot of infrastructure
1071 : * that pullup_replace_vars hasn't currently got.)
1072 : */
1073 41992 : if (parse->groupingSets)
1074 : {
1075 136 : rvcontext.need_phvs = true;
1076 136 : rvcontext.wrap_non_vars = true;
1077 : }
1078 :
1079 : /*
1080 : * Replace all of the top query's references to the subquery's outputs
1081 : * with copies of the adjusted subtlist items, being careful not to
1082 : * replace any of the jointree structure.
1083 : */
1084 41992 : perform_pullup_replace_vars(root, &rvcontext,
1085 : lowest_nulling_outer_join,
1086 : containing_appendrel);
1087 :
1088 : /*
1089 : * If the subquery had a LATERAL marker, propagate that to any of its
1090 : * child RTEs that could possibly now contain lateral cross-references.
1091 : * The children might or might not contain any actual lateral
1092 : * cross-references, but we have to mark the pulled-up child RTEs so that
1093 : * later planner stages will check for such.
1094 : */
1095 41988 : if (rte->lateral)
1096 : {
1097 836 : foreach(lc, subquery->rtable)
1098 : {
1099 504 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(lc);
1100 :
1101 504 : switch (child_rte->rtekind)
1102 : {
1103 216 : case RTE_RELATION:
1104 216 : if (child_rte->tablesample)
1105 12 : child_rte->lateral = true;
1106 216 : break;
1107 124 : case RTE_SUBQUERY:
1108 : case RTE_FUNCTION:
1109 : case RTE_VALUES:
1110 : case RTE_TABLEFUNC:
1111 124 : child_rte->lateral = true;
1112 124 : break;
1113 164 : case RTE_JOIN:
1114 : case RTE_CTE:
1115 : case RTE_NAMEDTUPLESTORE:
1116 : case RTE_RESULT:
1117 : /* these can't contain any lateral references */
1118 164 : break;
1119 : }
1120 504 : }
1121 : }
1122 :
1123 : /*
1124 : * Now append the adjusted rtable entries to upper query. (We hold off
1125 : * until after fixing the upper rtable entries; no point in running that
1126 : * code on the subquery ones too.)
1127 : */
1128 41988 : parse->rtable = list_concat(parse->rtable, subquery->rtable);
1129 :
1130 : /*
1131 : * Pull up any FOR UPDATE/SHARE markers, too. (OffsetVarNodes already
1132 : * adjusted the marker rtindexes, so just concat the lists.)
1133 : */
1134 41988 : parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
1135 :
1136 : /*
1137 : * We also have to fix the relid sets of any PlaceHolderVar nodes in the
1138 : * parent query. (This could perhaps be done by pullup_replace_vars(),
1139 : * but it seems cleaner to use two passes.) Note in particular that any
1140 : * PlaceHolderVar nodes just created by pullup_replace_vars() will be
1141 : * adjusted, so having created them with the subquery's varno is correct.
1142 : *
1143 : * Likewise, relids appearing in AppendRelInfo nodes have to be fixed. We
1144 : * already checked that this won't require introducing multiple subrelids
1145 : * into the single-slot AppendRelInfo structs.
1146 : */
1147 41988 : if (parse->hasSubLinks || root->glob->lastPHId != 0 ||
1148 36272 : root->append_rel_list)
1149 : {
1150 : Relids subrelids;
1151 :
1152 6794 : subrelids = get_relids_in_jointree((Node *) subquery->jointree, false);
1153 6794 : substitute_phv_relids((Node *) parse, varno, subrelids);
1154 6794 : fix_append_rel_relids(root->append_rel_list, varno, subrelids);
1155 : }
1156 :
1157 : /*
1158 : * And now add subquery's AppendRelInfos to our list.
1159 : */
1160 83976 : root->append_rel_list = list_concat(root->append_rel_list,
1161 41988 : subroot->append_rel_list);
1162 :
1163 : /*
1164 : * We don't have to do the equivalent bookkeeping for outer-join info,
1165 : * because that hasn't been set up yet. placeholder_list likewise.
1166 : */
1167 : Assert(root->join_info_list == NIL);
1168 : Assert(subroot->join_info_list == NIL);
1169 : Assert(root->placeholder_list == NIL);
1170 : Assert(subroot->placeholder_list == NIL);
1171 :
1172 : /*
1173 : * Miscellaneous housekeeping.
1174 : *
1175 : * Although replace_rte_variables() faithfully updated parse->hasSubLinks
1176 : * if it copied any SubLinks out of the subquery's targetlist, we still
1177 : * could have SubLinks added to the query in the expressions of FUNCTION
1178 : * and VALUES RTEs copied up from the subquery. So it's necessary to copy
1179 : * subquery->hasSubLinks anyway. Perhaps this can be improved someday.
1180 : */
1181 41988 : parse->hasSubLinks |= subquery->hasSubLinks;
1182 :
1183 : /* If subquery had any RLS conditions, now main query does too */
1184 41988 : parse->hasRowSecurity |= subquery->hasRowSecurity;
1185 :
1186 : /*
1187 : * subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
1188 : * hasTargetSRFs, so no work needed on those flags
1189 : */
1190 :
1191 : /*
1192 : * Return the adjusted subquery jointree to replace the RangeTblRef entry
1193 : * in parent's jointree; or, if the FromExpr is degenerate, just return
1194 : * its single member.
1195 : */
1196 : Assert(IsA(subquery->jointree, FromExpr));
1197 : Assert(subquery->jointree->fromlist != NIL);
1198 78072 : if (subquery->jointree->quals == NULL &&
1199 36084 : list_length(subquery->jointree->fromlist) == 1)
1200 35956 : return (Node *) linitial(subquery->jointree->fromlist);
1201 :
1202 6032 : return (Node *) subquery->jointree;
1203 : }
1204 :
1205 : /*
1206 : * pull_up_simple_union_all
1207 : * Pull up a single simple UNION ALL subquery.
1208 : *
1209 : * jtnode is a RangeTblRef that has been identified as a simple UNION ALL
1210 : * subquery by pull_up_subqueries. We pull up the leaf subqueries and
1211 : * build an "append relation" for the union set. The result value is just
1212 : * jtnode, since we don't actually need to change the query jointree.
1213 : */
1214 : static Node *
1215 774 : pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1216 : {
1217 774 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1218 774 : Query *subquery = rte->subquery;
1219 774 : int rtoffset = list_length(root->parse->rtable);
1220 : List *rtable;
1221 :
1222 : /*
1223 : * Make a modifiable copy of the subquery's rtable, so we can adjust
1224 : * upper-level Vars in it. There are no such Vars in the setOperations
1225 : * tree proper, so fixing the rtable should be sufficient.
1226 : */
1227 774 : rtable = copyObject(subquery->rtable);
1228 :
1229 : /*
1230 : * Upper-level vars in subquery are now one level closer to their parent
1231 : * than before. We don't have to worry about offsetting varnos, though,
1232 : * because the UNION leaf queries can't cross-reference each other.
1233 : */
1234 774 : IncrementVarSublevelsUp_rtable(rtable, -1, 1);
1235 :
1236 : /*
1237 : * If the UNION ALL subquery had a LATERAL marker, propagate that to all
1238 : * its children. The individual children might or might not contain any
1239 : * actual lateral cross-references, but we have to mark the pulled-up
1240 : * child RTEs so that later planner stages will check for such.
1241 : */
1242 774 : if (rte->lateral)
1243 : {
1244 : ListCell *rt;
1245 :
1246 96 : foreach(rt, rtable)
1247 : {
1248 64 : RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
1249 :
1250 : Assert(child_rte->rtekind == RTE_SUBQUERY);
1251 64 : child_rte->lateral = true;
1252 : }
1253 : }
1254 :
1255 : /*
1256 : * Append child RTEs to parent rtable.
1257 : */
1258 774 : root->parse->rtable = list_concat(root->parse->rtable, rtable);
1259 :
1260 : /*
1261 : * Recursively scan the subquery's setOperations tree and add
1262 : * AppendRelInfo nodes for leaf subqueries to the parent's
1263 : * append_rel_list. Also apply pull_up_subqueries to the leaf subqueries.
1264 : */
1265 : Assert(subquery->setOperations);
1266 774 : pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
1267 : rtoffset);
1268 :
1269 : /*
1270 : * Mark the parent as an append relation.
1271 : */
1272 774 : rte->inh = true;
1273 :
1274 774 : return jtnode;
1275 : }
1276 :
1277 : /*
1278 : * pull_up_union_leaf_queries -- recursive guts of pull_up_simple_union_all
1279 : *
1280 : * Build an AppendRelInfo for each leaf query in the setop tree, and then
1281 : * apply pull_up_subqueries to the leaf query.
1282 : *
1283 : * Note that setOpQuery is the Query containing the setOp node, whose tlist
1284 : * contains references to all the setop output columns. When called from
1285 : * pull_up_simple_union_all, this is *not* the same as root->parse, which is
1286 : * the parent Query we are pulling up into.
1287 : *
1288 : * parentRTindex is the appendrel parent's index in root->parse->rtable.
1289 : *
1290 : * The child RTEs have already been copied to the parent. childRToffset
1291 : * tells us where in the parent's range table they were copied. When called
1292 : * from flatten_simple_union_all, childRToffset is 0 since the child RTEs
1293 : * were already in root->parse->rtable and no RT index adjustment is needed.
1294 : */
1295 : static void
1296 6960 : pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
1297 : Query *setOpQuery, int childRToffset)
1298 : {
1299 6960 : if (IsA(setOp, RangeTblRef))
1300 : {
1301 4560 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1302 : int childRTindex;
1303 : AppendRelInfo *appinfo;
1304 :
1305 : /*
1306 : * Calculate the index in the parent's range table
1307 : */
1308 4560 : childRTindex = childRToffset + rtr->rtindex;
1309 :
1310 : /*
1311 : * Build a suitable AppendRelInfo, and attach to parent's list.
1312 : */
1313 4560 : appinfo = makeNode(AppendRelInfo);
1314 4560 : appinfo->parent_relid = parentRTindex;
1315 4560 : appinfo->child_relid = childRTindex;
1316 4560 : appinfo->parent_reltype = InvalidOid;
1317 4560 : appinfo->child_reltype = InvalidOid;
1318 4560 : make_setop_translation_list(setOpQuery, childRTindex, appinfo);
1319 4560 : appinfo->parent_reloid = InvalidOid;
1320 4560 : root->append_rel_list = lappend(root->append_rel_list, appinfo);
1321 :
1322 : /*
1323 : * Recursively apply pull_up_subqueries to the new child RTE. (We
1324 : * must build the AppendRelInfo first, because this will modify it.)
1325 : * Note that we can pass NULL for containing-join info even if we're
1326 : * actually under an outer join, because the child's expressions
1327 : * aren't going to propagate up to the join. Also, we ignore the
1328 : * possibility that pull_up_subqueries_recurse() returns a different
1329 : * jointree node than what we pass it; if it does, the important thing
1330 : * is that it replaced the child relid in the AppendRelInfo node.
1331 : */
1332 4560 : rtr = makeNode(RangeTblRef);
1333 4560 : rtr->rtindex = childRTindex;
1334 4560 : (void) pull_up_subqueries_recurse(root, (Node *) rtr,
1335 : NULL, NULL, appinfo);
1336 : }
1337 2400 : else if (IsA(setOp, SetOperationStmt))
1338 : {
1339 2400 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1340 :
1341 : /* Recurse to reach leaf queries */
1342 2400 : pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
1343 : childRToffset);
1344 2400 : pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
1345 : childRToffset);
1346 : }
1347 : else
1348 : {
1349 0 : elog(ERROR, "unrecognized node type: %d",
1350 : (int) nodeTag(setOp));
1351 : }
1352 6960 : }
1353 :
1354 : /*
1355 : * make_setop_translation_list
1356 : * Build the list of translations from parent Vars to child Vars for
1357 : * a UNION ALL member. (At this point it's just a simple list of
1358 : * referencing Vars, but if we succeed in pulling up the member
1359 : * subquery, the Vars will get replaced by pulled-up expressions.)
1360 : * Also create the rather trivial reverse-translation array.
1361 : */
1362 : static void
1363 4560 : make_setop_translation_list(Query *query, Index newvarno,
1364 : AppendRelInfo *appinfo)
1365 : {
1366 4560 : List *vars = NIL;
1367 : AttrNumber *pcolnos;
1368 : ListCell *l;
1369 :
1370 : /* Initialize reverse-translation array with all entries zero */
1371 : /* (entries for resjunk columns will stay that way) */
1372 4560 : appinfo->num_child_cols = list_length(query->targetList);
1373 4560 : appinfo->parent_colnos = pcolnos =
1374 4560 : (AttrNumber *) palloc0(appinfo->num_child_cols * sizeof(AttrNumber));
1375 :
1376 12014 : foreach(l, query->targetList)
1377 : {
1378 7454 : TargetEntry *tle = (TargetEntry *) lfirst(l);
1379 :
1380 7454 : if (tle->resjunk)
1381 0 : continue;
1382 :
1383 7454 : vars = lappend(vars, makeVarFromTargetEntry(newvarno, tle));
1384 7454 : pcolnos[tle->resno - 1] = tle->resno;
1385 : }
1386 :
1387 4560 : appinfo->translated_vars = vars;
1388 4560 : }
1389 :
1390 : /*
1391 : * is_simple_subquery
1392 : * Check a subquery in the range table to see if it's simple enough
1393 : * to pull up into the parent query.
1394 : *
1395 : * rte is the RTE_SUBQUERY RangeTblEntry that contained the subquery.
1396 : * (Note subquery is not necessarily equal to rte->subquery; it could be a
1397 : * processed copy of that.)
1398 : * lowest_outer_join is the lowest outer join above the subquery, or NULL.
1399 : */
1400 : static bool
1401 91260 : is_simple_subquery(Query *subquery, RangeTblEntry *rte,
1402 : JoinExpr *lowest_outer_join)
1403 : {
1404 : /*
1405 : * Let's just make sure it's a valid subselect ...
1406 : */
1407 91260 : if (!IsA(subquery, Query) ||
1408 91260 : subquery->commandType != CMD_SELECT)
1409 0 : elog(ERROR, "subquery is bogus");
1410 :
1411 : /*
1412 : * Can't currently pull up a query with setops (unless it's simple UNION
1413 : * ALL, which is handled by a different code path). Maybe after querytree
1414 : * redesign...
1415 : */
1416 91260 : if (subquery->setOperations)
1417 1294 : return false;
1418 :
1419 : /*
1420 : * Can't pull up a subquery involving grouping, aggregation, SRFs,
1421 : * sorting, limiting, or WITH. (XXX WITH could possibly be allowed later)
1422 : *
1423 : * We also don't pull up a subquery that has explicit FOR UPDATE/SHARE
1424 : * clauses, because pullup would cause the locking to occur semantically
1425 : * higher than it should. Implicit FOR UPDATE/SHARE is okay because in
1426 : * that case the locking was originally declared in the upper query
1427 : * anyway.
1428 : */
1429 89966 : if (subquery->hasAggs ||
1430 89472 : subquery->hasWindowFuncs ||
1431 89376 : subquery->hasTargetSRFs ||
1432 88320 : subquery->groupClause ||
1433 88284 : subquery->groupingSets ||
1434 88284 : subquery->havingQual ||
1435 88284 : subquery->sortClause ||
1436 87530 : subquery->distinctClause ||
1437 87426 : subquery->limitOffset ||
1438 87242 : subquery->limitCount ||
1439 87070 : subquery->hasForUpdate ||
1440 87058 : subquery->cteList)
1441 2956 : return false;
1442 :
1443 : /*
1444 : * Don't pull up if the RTE represents a security-barrier view; we
1445 : * couldn't prevent information leakage once the RTE's Vars are scattered
1446 : * about in the upper query.
1447 : */
1448 87010 : if (rte->security_barrier)
1449 184 : return false;
1450 :
1451 : /*
1452 : * If the subquery is LATERAL, check for pullup restrictions from that.
1453 : */
1454 86826 : if (rte->lateral)
1455 : {
1456 : bool restricted;
1457 : Relids safe_upper_varnos;
1458 :
1459 : /*
1460 : * The subquery's WHERE and JOIN/ON quals mustn't contain any lateral
1461 : * references to rels outside a higher outer join (including the case
1462 : * where the outer join is within the subquery itself). In such a
1463 : * case, pulling up would result in a situation where we need to
1464 : * postpone quals from below an outer join to above it, which is
1465 : * probably completely wrong and in any case is a complication that
1466 : * doesn't seem worth addressing at the moment.
1467 : */
1468 708 : if (lowest_outer_join != NULL)
1469 : {
1470 248 : restricted = true;
1471 248 : safe_upper_varnos = get_relids_in_jointree((Node *) lowest_outer_join,
1472 : true);
1473 : }
1474 : else
1475 : {
1476 460 : restricted = false;
1477 460 : safe_upper_varnos = NULL; /* doesn't matter */
1478 : }
1479 :
1480 708 : if (jointree_contains_lateral_outer_refs((Node *) subquery->jointree,
1481 : restricted, safe_upper_varnos))
1482 8 : return false;
1483 :
1484 : /*
1485 : * If there's an outer join above the LATERAL subquery, also disallow
1486 : * pullup if the subquery's targetlist has any references to rels
1487 : * outside the outer join, since these might get pulled into quals
1488 : * above the subquery (but in or below the outer join) and then lead
1489 : * to qual-postponement issues similar to the case checked for above.
1490 : * (We wouldn't need to prevent pullup if no such references appear in
1491 : * outer-query quals, but we don't have enough info here to check
1492 : * that. Also, maybe this restriction could be removed if we forced
1493 : * such refs to be wrapped in PlaceHolderVars, even when they're below
1494 : * the nearest outer join? But it's a pretty hokey usage, so not
1495 : * clear this is worth sweating over.)
1496 : */
1497 700 : if (lowest_outer_join != NULL)
1498 : {
1499 248 : Relids lvarnos = pull_varnos_of_level((Node *) subquery->targetList, 1);
1500 :
1501 248 : if (!bms_is_subset(lvarnos, safe_upper_varnos))
1502 8 : return false;
1503 : }
1504 : }
1505 :
1506 : /*
1507 : * Don't pull up a subquery that has any volatile functions in its
1508 : * targetlist. Otherwise we might introduce multiple evaluations of these
1509 : * functions, if they get copied to multiple places in the upper query,
1510 : * leading to surprising results. (Note: the PlaceHolderVar mechanism
1511 : * doesn't quite guarantee single evaluation; else we could pull up anyway
1512 : * and just wrap such items in PlaceHolderVars ...)
1513 : */
1514 86810 : if (contain_volatile_functions((Node *) subquery->targetList))
1515 84 : return false;
1516 :
1517 86726 : return true;
1518 : }
1519 :
1520 : /*
1521 : * pull_up_simple_values
1522 : * Pull up a single simple VALUES RTE.
1523 : *
1524 : * jtnode is a RangeTblRef that has been identified as a simple VALUES RTE
1525 : * by pull_up_subqueries. We always return a RangeTblRef representing a
1526 : * RESULT RTE to replace it (all failure cases should have been detected by
1527 : * is_simple_values()). Actually, what we return is just jtnode, because
1528 : * we replace the VALUES RTE in the rangetable with the RESULT RTE.
1529 : *
1530 : * rte is the RangeTblEntry referenced by jtnode. Because of the limited
1531 : * possible usage of VALUES RTEs, we do not need the remaining parameters
1532 : * of pull_up_subqueries_recurse.
1533 : */
1534 : static Node *
1535 602 : pull_up_simple_values(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
1536 : {
1537 602 : Query *parse = root->parse;
1538 602 : int varno = ((RangeTblRef *) jtnode)->rtindex;
1539 : List *values_list;
1540 : List *tlist;
1541 : AttrNumber attrno;
1542 : pullup_replace_vars_context rvcontext;
1543 : ListCell *lc;
1544 :
1545 : Assert(rte->rtekind == RTE_VALUES);
1546 : Assert(list_length(rte->values_lists) == 1);
1547 :
1548 : /*
1549 : * Need a modifiable copy of the VALUES list to hack on, just in case it's
1550 : * multiply referenced.
1551 : */
1552 602 : values_list = copyObject(linitial(rte->values_lists));
1553 :
1554 : /*
1555 : * The VALUES RTE can't contain any Vars of level zero, let alone any that
1556 : * are join aliases, so no need to flatten join alias Vars.
1557 : */
1558 : Assert(!contain_vars_of_level((Node *) values_list, 0));
1559 :
1560 : /*
1561 : * Set up required context data for pullup_replace_vars. In particular,
1562 : * we have to make the VALUES list look like a subquery targetlist.
1563 : */
1564 602 : tlist = NIL;
1565 602 : attrno = 1;
1566 1360 : foreach(lc, values_list)
1567 : {
1568 758 : tlist = lappend(tlist,
1569 758 : makeTargetEntry((Expr *) lfirst(lc),
1570 : attrno,
1571 : NULL,
1572 : false));
1573 758 : attrno++;
1574 : }
1575 602 : rvcontext.root = root;
1576 602 : rvcontext.targetlist = tlist;
1577 602 : rvcontext.target_rte = rte;
1578 602 : rvcontext.relids = NULL;
1579 602 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1580 602 : rvcontext.varno = varno;
1581 602 : rvcontext.need_phvs = false;
1582 602 : rvcontext.wrap_non_vars = false;
1583 : /* initialize cache array with indexes 0 .. length(tlist) */
1584 602 : rvcontext.rv_cache = palloc0((list_length(tlist) + 1) *
1585 : sizeof(Node *));
1586 :
1587 : /*
1588 : * Replace all of the top query's references to the RTE's outputs with
1589 : * copies of the adjusted VALUES expressions, being careful not to replace
1590 : * any of the jointree structure. We can assume there's no outer joins or
1591 : * appendrels in the dummy Query that surrounds a VALUES RTE.
1592 : */
1593 602 : perform_pullup_replace_vars(root, &rvcontext, NULL, NULL);
1594 :
1595 : /*
1596 : * There should be no appendrels to fix, nor any outer joins and hence no
1597 : * PlaceHolderVars.
1598 : */
1599 : Assert(root->append_rel_list == NIL);
1600 : Assert(root->join_info_list == NIL);
1601 : Assert(root->placeholder_list == NIL);
1602 :
1603 : /*
1604 : * Replace the VALUES RTE with a RESULT RTE. The VALUES RTE is the only
1605 : * rtable entry in the current query level, so this is easy.
1606 : */
1607 : Assert(list_length(parse->rtable) == 1);
1608 :
1609 : /* Create suitable RTE */
1610 602 : rte = makeNode(RangeTblEntry);
1611 602 : rte->rtekind = RTE_RESULT;
1612 602 : rte->eref = makeAlias("*RESULT*", NIL);
1613 :
1614 : /* Replace rangetable */
1615 602 : parse->rtable = list_make1(rte);
1616 :
1617 : /* We could manufacture a new RangeTblRef, but the one we have is fine */
1618 : Assert(varno == 1);
1619 :
1620 602 : return jtnode;
1621 : }
1622 :
1623 : /*
1624 : * is_simple_values
1625 : * Check a VALUES RTE in the range table to see if it's simple enough
1626 : * to pull up into the parent query.
1627 : *
1628 : * rte is the RTE_VALUES RangeTblEntry to check.
1629 : */
1630 : static bool
1631 4960 : is_simple_values(PlannerInfo *root, RangeTblEntry *rte)
1632 : {
1633 : Assert(rte->rtekind == RTE_VALUES);
1634 :
1635 : /*
1636 : * There must be exactly one VALUES list, else it's not semantically
1637 : * correct to replace the VALUES RTE with a RESULT RTE, nor would we have
1638 : * a unique set of expressions to substitute into the parent query.
1639 : */
1640 4960 : if (list_length(rte->values_lists) != 1)
1641 4358 : return false;
1642 :
1643 : /*
1644 : * Because VALUES can't appear under an outer join (or at least, we won't
1645 : * try to pull it up if it does), we need not worry about LATERAL, nor
1646 : * about validity of PHVs for the VALUES' outputs.
1647 : */
1648 :
1649 : /*
1650 : * Don't pull up a VALUES that contains any set-returning or volatile
1651 : * functions. The considerations here are basically identical to the
1652 : * restrictions on a pull-able subquery's targetlist.
1653 : */
1654 1204 : if (expression_returns_set((Node *) rte->values_lists) ||
1655 602 : contain_volatile_functions((Node *) rte->values_lists))
1656 0 : return false;
1657 :
1658 : /*
1659 : * Do not pull up a VALUES that's not the only RTE in its parent query.
1660 : * This is actually the only case that the parser will generate at the
1661 : * moment, and assuming this is true greatly simplifies
1662 : * pull_up_simple_values().
1663 : */
1664 602 : if (list_length(root->parse->rtable) != 1 ||
1665 602 : rte != (RangeTblEntry *) linitial(root->parse->rtable))
1666 0 : return false;
1667 :
1668 602 : return true;
1669 : }
1670 :
1671 : /*
1672 : * pull_up_constant_function
1673 : * Pull up an RTE_FUNCTION expression that was simplified to a constant.
1674 : *
1675 : * jtnode is a RangeTblRef that has been identified as a FUNCTION RTE by
1676 : * pull_up_subqueries. If its expression is just a Const, hoist that value
1677 : * up into the parent query, and replace the RTE_FUNCTION with RTE_RESULT.
1678 : *
1679 : * In principle we could pull up any immutable expression, but we don't.
1680 : * That might result in multiple evaluations of the expression, which could
1681 : * be costly if it's not just a Const. Also, the main value of this is
1682 : * to let the constant participate in further const-folding, and of course
1683 : * that won't happen for a non-Const.
1684 : *
1685 : * The pulled-up value might need to be wrapped in a PlaceHolderVar if the
1686 : * RTE is below an outer join or is part of an appendrel; the extra
1687 : * parameters show whether that's needed.
1688 : */
1689 : static Node *
1690 31794 : pull_up_constant_function(PlannerInfo *root, Node *jtnode,
1691 : RangeTblEntry *rte,
1692 : JoinExpr *lowest_nulling_outer_join,
1693 : AppendRelInfo *containing_appendrel)
1694 : {
1695 31794 : Query *parse = root->parse;
1696 : RangeTblFunction *rtf;
1697 : TypeFuncClass functypclass;
1698 : Oid funcrettype;
1699 : TupleDesc tupdesc;
1700 : pullup_replace_vars_context rvcontext;
1701 :
1702 : /* Fail if the RTE has ORDINALITY - we don't implement that here. */
1703 31794 : if (rte->funcordinality)
1704 6374 : return jtnode;
1705 :
1706 : /* Fail if RTE isn't a single, simple Const expr */
1707 25420 : if (list_length(rte->functions) != 1)
1708 50 : return jtnode;
1709 25370 : rtf = linitial_node(RangeTblFunction, rte->functions);
1710 25370 : if (!IsA(rtf->funcexpr, Const))
1711 25146 : return jtnode;
1712 :
1713 : /*
1714 : * If the function's result is not a scalar, we punt. In principle we
1715 : * could break the composite constant value apart into per-column
1716 : * constants, but for now it seems not worth the work.
1717 : */
1718 224 : if (rtf->funccolcount != 1)
1719 16 : return jtnode; /* definitely composite */
1720 :
1721 208 : functypclass = get_expr_result_type(rtf->funcexpr,
1722 : &funcrettype,
1723 : &tupdesc);
1724 208 : if (functypclass != TYPEFUNC_SCALAR)
1725 8 : return jtnode; /* must be a one-column composite type */
1726 :
1727 : /* Create context for applying pullup_replace_vars */
1728 200 : rvcontext.root = root;
1729 200 : rvcontext.targetlist = list_make1(makeTargetEntry((Expr *) rtf->funcexpr,
1730 : 1, /* resno */
1731 : NULL, /* resname */
1732 : false)); /* resjunk */
1733 200 : rvcontext.target_rte = rte;
1734 :
1735 : /*
1736 : * Since this function was reduced to a Const, it doesn't contain any
1737 : * lateral references, even if it's marked as LATERAL. This means we
1738 : * don't need to fill relids.
1739 : */
1740 200 : rvcontext.relids = NULL;
1741 :
1742 200 : rvcontext.outer_hasSubLinks = &parse->hasSubLinks;
1743 200 : rvcontext.varno = ((RangeTblRef *) jtnode)->rtindex;
1744 : /* these flags will be set below, if needed */
1745 200 : rvcontext.need_phvs = false;
1746 200 : rvcontext.wrap_non_vars = false;
1747 : /* initialize cache array with indexes 0 .. length(tlist) */
1748 200 : rvcontext.rv_cache = palloc0((list_length(rvcontext.targetlist) + 1) *
1749 : sizeof(Node *));
1750 :
1751 : /*
1752 : * If we are under an outer join then non-nullable items and lateral
1753 : * references may have to be turned into PlaceHolderVars.
1754 : */
1755 200 : if (lowest_nulling_outer_join != NULL)
1756 12 : rvcontext.need_phvs = true;
1757 :
1758 : /*
1759 : * If we are dealing with an appendrel member then anything that's not a
1760 : * simple Var has to be turned into a PlaceHolderVar. (See comments in
1761 : * pull_up_simple_subquery().)
1762 : */
1763 200 : if (containing_appendrel != NULL)
1764 : {
1765 0 : rvcontext.need_phvs = true;
1766 0 : rvcontext.wrap_non_vars = true;
1767 : }
1768 :
1769 : /*
1770 : * If the parent query uses grouping sets, we need a PlaceHolderVar for
1771 : * anything that's not a simple Var.
1772 : */
1773 200 : if (parse->groupingSets)
1774 : {
1775 0 : rvcontext.need_phvs = true;
1776 0 : rvcontext.wrap_non_vars = true;
1777 : }
1778 :
1779 : /*
1780 : * Replace all of the top query's references to the RTE's output with
1781 : * copies of the funcexpr, being careful not to replace any of the
1782 : * jointree structure.
1783 : */
1784 200 : perform_pullup_replace_vars(root, &rvcontext,
1785 : lowest_nulling_outer_join,
1786 : containing_appendrel);
1787 :
1788 : /*
1789 : * We don't need to bother with changing PlaceHolderVars in the parent
1790 : * query. Their references to the RT index are still good for now, and
1791 : * will get removed later if we're able to drop the RTE_RESULT.
1792 : */
1793 :
1794 : /*
1795 : * Convert the RTE to be RTE_RESULT type, signifying that we don't need to
1796 : * scan it anymore, and zero out RTE_FUNCTION-specific fields.
1797 : */
1798 200 : rte->rtekind = RTE_RESULT;
1799 200 : rte->functions = NIL;
1800 :
1801 : /*
1802 : * We can reuse the RangeTblRef node.
1803 : */
1804 200 : return jtnode;
1805 : }
1806 :
1807 : /*
1808 : * is_simple_union_all
1809 : * Check a subquery to see if it's a simple UNION ALL.
1810 : *
1811 : * We require all the setops to be UNION ALL (no mixing) and there can't be
1812 : * any datatype coercions involved, ie, all the leaf queries must emit the
1813 : * same datatypes.
1814 : */
1815 : static bool
1816 7204 : is_simple_union_all(Query *subquery)
1817 : {
1818 : SetOperationStmt *topop;
1819 :
1820 : /* Let's just make sure it's a valid subselect ... */
1821 7204 : if (!IsA(subquery, Query) ||
1822 7204 : subquery->commandType != CMD_SELECT)
1823 0 : elog(ERROR, "subquery is bogus");
1824 :
1825 : /* Is it a set-operation query at all? */
1826 7204 : topop = castNode(SetOperationStmt, subquery->setOperations);
1827 7204 : if (!topop)
1828 5910 : return false;
1829 :
1830 : /* Can't handle ORDER BY, LIMIT/OFFSET, locking, or WITH */
1831 1294 : if (subquery->sortClause ||
1832 1266 : subquery->limitOffset ||
1833 1266 : subquery->limitCount ||
1834 1266 : subquery->rowMarks ||
1835 1266 : subquery->cteList)
1836 32 : return false;
1837 :
1838 : /* Recursively check the tree of set operations */
1839 1262 : return is_simple_union_all_recurse((Node *) topop, subquery,
1840 : topop->colTypes);
1841 : }
1842 :
1843 : static bool
1844 9248 : is_simple_union_all_recurse(Node *setOp, Query *setOpQuery, List *colTypes)
1845 : {
1846 9248 : if (IsA(setOp, RangeTblRef))
1847 : {
1848 4932 : RangeTblRef *rtr = (RangeTblRef *) setOp;
1849 4932 : RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
1850 4932 : Query *subquery = rte->subquery;
1851 :
1852 : Assert(subquery != NULL);
1853 :
1854 : /* Leaf nodes are OK if they match the toplevel column types */
1855 : /* We don't have to compare typmods or collations here */
1856 4932 : return tlist_same_datatypes(subquery->targetList, colTypes, true);
1857 : }
1858 4316 : else if (IsA(setOp, SetOperationStmt))
1859 : {
1860 4316 : SetOperationStmt *op = (SetOperationStmt *) setOp;
1861 :
1862 : /* Must be UNION ALL */
1863 4316 : if (op->op != SETOP_UNION || !op->all)
1864 1516 : return false;
1865 :
1866 : /* Recurse to check inputs */
1867 5380 : return is_simple_union_all_recurse(op->larg, setOpQuery, colTypes) &&
1868 2580 : is_simple_union_all_recurse(op->rarg, setOpQuery, colTypes);
1869 : }
1870 : else
1871 : {
1872 0 : elog(ERROR, "unrecognized node type: %d",
1873 : (int) nodeTag(setOp));
1874 : return false; /* keep compiler quiet */
1875 : }
1876 : }
1877 :
1878 : /*
1879 : * is_safe_append_member
1880 : * Check a subquery that is a leaf of a UNION ALL appendrel to see if it's
1881 : * safe to pull up.
1882 : */
1883 : static bool
1884 5794 : is_safe_append_member(Query *subquery)
1885 : {
1886 : FromExpr *jtnode;
1887 :
1888 : /*
1889 : * It's only safe to pull up the child if its jointree contains exactly
1890 : * one RTE, else the AppendRelInfo data structure breaks. The one base RTE
1891 : * could be buried in several levels of FromExpr, however. Also, if the
1892 : * child's jointree is completely empty, we can pull up because
1893 : * pull_up_simple_subquery will insert a single RTE_RESULT RTE instead.
1894 : *
1895 : * Also, the child can't have any WHERE quals because there's no place to
1896 : * put them in an appendrel. (This is a bit annoying...) If we didn't
1897 : * need to check this, we'd just test whether get_relids_in_jointree()
1898 : * yields a singleton set, to be more consistent with the coding of
1899 : * fix_append_rel_relids().
1900 : */
1901 5794 : jtnode = subquery->jointree;
1902 : Assert(IsA(jtnode, FromExpr));
1903 : /* Check the completely-empty case */
1904 5794 : if (jtnode->fromlist == NIL && jtnode->quals == NULL)
1905 324 : return true;
1906 : /* Check the more general case */
1907 8278 : while (IsA(jtnode, FromExpr))
1908 : {
1909 5478 : if (jtnode->quals != NULL)
1910 2670 : return false;
1911 2808 : if (list_length(jtnode->fromlist) != 1)
1912 0 : return false;
1913 2808 : jtnode = linitial(jtnode->fromlist);
1914 : }
1915 2800 : if (!IsA(jtnode, RangeTblRef))
1916 36 : return false;
1917 :
1918 2764 : return true;
1919 : }
1920 :
1921 : /*
1922 : * jointree_contains_lateral_outer_refs
1923 : * Check for disallowed lateral references in a jointree's quals
1924 : *
1925 : * If restricted is false, all level-1 Vars are allowed (but we still must
1926 : * search the jointree, since it might contain outer joins below which there
1927 : * will be restrictions). If restricted is true, return true when any qual
1928 : * in the jointree contains level-1 Vars coming from outside the rels listed
1929 : * in safe_upper_varnos.
1930 : */
1931 : static bool
1932 1640 : jointree_contains_lateral_outer_refs(Node *jtnode, bool restricted,
1933 : Relids safe_upper_varnos)
1934 : {
1935 1640 : if (jtnode == NULL)
1936 0 : return false;
1937 1640 : if (IsA(jtnode, RangeTblRef))
1938 792 : return false;
1939 848 : else if (IsA(jtnode, FromExpr))
1940 : {
1941 716 : FromExpr *f = (FromExpr *) jtnode;
1942 : ListCell *l;
1943 :
1944 : /* First, recurse to check child joins */
1945 1376 : foreach(l, f->fromlist)
1946 : {
1947 668 : if (jointree_contains_lateral_outer_refs(lfirst(l),
1948 : restricted,
1949 : safe_upper_varnos))
1950 8 : return true;
1951 : }
1952 :
1953 : /* Then check the top-level quals */
1954 708 : if (restricted &&
1955 256 : !bms_is_subset(pull_varnos_of_level(f->quals, 1),
1956 : safe_upper_varnos))
1957 0 : return true;
1958 : }
1959 132 : else if (IsA(jtnode, JoinExpr))
1960 : {
1961 132 : JoinExpr *j = (JoinExpr *) jtnode;
1962 :
1963 : /*
1964 : * If this is an outer join, we mustn't allow any upper lateral
1965 : * references in or below it.
1966 : */
1967 132 : if (j->jointype != JOIN_INNER)
1968 : {
1969 52 : restricted = true;
1970 52 : safe_upper_varnos = NULL;
1971 : }
1972 :
1973 : /* Check the child joins */
1974 132 : if (jointree_contains_lateral_outer_refs(j->larg,
1975 : restricted,
1976 : safe_upper_varnos))
1977 0 : return true;
1978 132 : if (jointree_contains_lateral_outer_refs(j->rarg,
1979 : restricted,
1980 : safe_upper_varnos))
1981 0 : return true;
1982 :
1983 : /* Check the JOIN's qual clauses */
1984 132 : if (restricted &&
1985 132 : !bms_is_subset(pull_varnos_of_level(j->quals, 1),
1986 : safe_upper_varnos))
1987 8 : return true;
1988 : }
1989 : else
1990 0 : elog(ERROR, "unrecognized node type: %d",
1991 : (int) nodeTag(jtnode));
1992 832 : return false;
1993 : }
1994 :
1995 : /*
1996 : * Perform pullup_replace_vars everyplace it's needed in the query tree.
1997 : *
1998 : * Caller has already filled *rvcontext with data describing what to
1999 : * substitute for Vars referencing the target subquery. In addition
2000 : * we need the identity of the lowest outer join that can null the
2001 : * target subquery, and its containing appendrel if any.
2002 : */
2003 : static void
2004 42794 : perform_pullup_replace_vars(PlannerInfo *root,
2005 : pullup_replace_vars_context *rvcontext,
2006 : JoinExpr *lowest_nulling_outer_join,
2007 : AppendRelInfo *containing_appendrel)
2008 : {
2009 42794 : Query *parse = root->parse;
2010 : ListCell *lc;
2011 :
2012 : /*
2013 : * Replace all of the top query's references to the subquery's outputs
2014 : * with copies of the adjusted subtlist items, being careful not to
2015 : * replace any of the jointree structure. (This'd be a lot cleaner if we
2016 : * could use query_tree_mutator.) We have to use PHVs in the targetList,
2017 : * returningList, and havingQual, since those are certainly above any
2018 : * outer join. replace_vars_in_jointree tracks its location in the
2019 : * jointree and uses PHVs or not appropriately.
2020 : */
2021 42794 : parse->targetList = (List *)
2022 42794 : pullup_replace_vars((Node *) parse->targetList, rvcontext);
2023 42794 : parse->returningList = (List *)
2024 42794 : pullup_replace_vars((Node *) parse->returningList, rvcontext);
2025 42794 : if (parse->onConflict)
2026 : {
2027 32 : parse->onConflict->onConflictSet = (List *)
2028 16 : pullup_replace_vars((Node *) parse->onConflict->onConflictSet,
2029 : rvcontext);
2030 16 : parse->onConflict->onConflictWhere =
2031 16 : pullup_replace_vars(parse->onConflict->onConflictWhere,
2032 : rvcontext);
2033 :
2034 : /*
2035 : * We assume ON CONFLICT's arbiterElems, arbiterWhere, exclRelTlist
2036 : * can't contain any references to a subquery.
2037 : */
2038 : }
2039 42794 : replace_vars_in_jointree((Node *) parse->jointree, rvcontext,
2040 : lowest_nulling_outer_join);
2041 : Assert(parse->setOperations == NULL);
2042 42790 : parse->havingQual = pullup_replace_vars(parse->havingQual, rvcontext);
2043 :
2044 : /*
2045 : * Replace references in the translated_vars lists of appendrels. When
2046 : * pulling up an appendrel member, we do not need PHVs in the list of the
2047 : * parent appendrel --- there isn't any outer join between. Elsewhere,
2048 : * use PHVs for safety. (This analysis could be made tighter but it seems
2049 : * unlikely to be worth much trouble.)
2050 : */
2051 45588 : foreach(lc, root->append_rel_list)
2052 : {
2053 2798 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
2054 2798 : bool save_need_phvs = rvcontext->need_phvs;
2055 :
2056 2798 : if (appinfo == containing_appendrel)
2057 1526 : rvcontext->need_phvs = false;
2058 2798 : appinfo->translated_vars = (List *)
2059 2798 : pullup_replace_vars((Node *) appinfo->translated_vars, rvcontext);
2060 2798 : rvcontext->need_phvs = save_need_phvs;
2061 : }
2062 :
2063 : /*
2064 : * Replace references in the joinaliasvars lists of join RTEs.
2065 : *
2066 : * You might think that we could avoid using PHVs for alias vars of joins
2067 : * below lowest_nulling_outer_join, but that doesn't work because the
2068 : * alias vars could be referenced above that join; we need the PHVs to be
2069 : * present in such references after the alias vars get flattened. (It
2070 : * might be worth trying to be smarter here, someday.)
2071 : */
2072 117020 : foreach(lc, parse->rtable)
2073 : {
2074 74230 : RangeTblEntry *otherrte = (RangeTblEntry *) lfirst(lc);
2075 :
2076 74230 : if (otherrte->rtekind == RTE_JOIN)
2077 2432 : otherrte->joinaliasvars = (List *)
2078 2432 : pullup_replace_vars((Node *) otherrte->joinaliasvars,
2079 : rvcontext);
2080 : }
2081 42790 : }
2082 :
2083 : /*
2084 : * Helper routine for perform_pullup_replace_vars: do pullup_replace_vars on
2085 : * every expression in the jointree, without changing the jointree structure
2086 : * itself. Ugly, but there's no other way...
2087 : *
2088 : * If we are at or below lowest_nulling_outer_join, we can suppress use of
2089 : * PlaceHolderVars wrapped around the replacement expressions.
2090 : */
2091 : static void
2092 96478 : replace_vars_in_jointree(Node *jtnode,
2093 : pullup_replace_vars_context *context,
2094 : JoinExpr *lowest_nulling_outer_join)
2095 : {
2096 96478 : if (jtnode == NULL)
2097 0 : return;
2098 96478 : if (IsA(jtnode, RangeTblRef))
2099 : {
2100 : /*
2101 : * If the RangeTblRef refers to a LATERAL subquery (that isn't the
2102 : * same subquery we're pulling up), it might contain references to the
2103 : * target subquery, which we must replace. We drive this from the
2104 : * jointree scan, rather than a scan of the rtable, for a couple of
2105 : * reasons: we can avoid processing no-longer-referenced RTEs, and we
2106 : * can use the appropriate setting of need_phvs depending on whether
2107 : * the RTE is above possibly-nulling outer joins or not.
2108 : */
2109 48440 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2110 :
2111 48440 : if (varno != context->varno) /* ignore target subquery itself */
2112 : {
2113 7172 : RangeTblEntry *rte = rt_fetch(varno, context->root->parse->rtable);
2114 :
2115 : Assert(rte != context->target_rte);
2116 7172 : if (rte->lateral)
2117 : {
2118 464 : switch (rte->rtekind)
2119 : {
2120 0 : case RTE_RELATION:
2121 : /* shouldn't be marked LATERAL unless tablesample */
2122 : Assert(rte->tablesample);
2123 0 : rte->tablesample = (TableSampleClause *)
2124 0 : pullup_replace_vars((Node *) rte->tablesample,
2125 : context);
2126 0 : break;
2127 248 : case RTE_SUBQUERY:
2128 248 : rte->subquery =
2129 248 : pullup_replace_vars_subquery(rte->subquery,
2130 : context);
2131 248 : break;
2132 172 : case RTE_FUNCTION:
2133 172 : rte->functions = (List *)
2134 172 : pullup_replace_vars((Node *) rte->functions,
2135 : context);
2136 172 : break;
2137 44 : case RTE_TABLEFUNC:
2138 44 : rte->tablefunc = (TableFunc *)
2139 44 : pullup_replace_vars((Node *) rte->tablefunc,
2140 : context);
2141 44 : break;
2142 0 : case RTE_VALUES:
2143 0 : rte->values_lists = (List *)
2144 0 : pullup_replace_vars((Node *) rte->values_lists,
2145 : context);
2146 0 : break;
2147 0 : case RTE_JOIN:
2148 : case RTE_CTE:
2149 : case RTE_NAMEDTUPLESTORE:
2150 : case RTE_RESULT:
2151 : /* these shouldn't be marked LATERAL */
2152 : Assert(false);
2153 0 : break;
2154 : }
2155 48440 : }
2156 : }
2157 : }
2158 48038 : else if (IsA(jtnode, FromExpr))
2159 : {
2160 44118 : FromExpr *f = (FromExpr *) jtnode;
2161 : ListCell *l;
2162 :
2163 89962 : foreach(l, f->fromlist)
2164 45844 : replace_vars_in_jointree(lfirst(l), context,
2165 : lowest_nulling_outer_join);
2166 44118 : f->quals = pullup_replace_vars(f->quals, context);
2167 : }
2168 3920 : else if (IsA(jtnode, JoinExpr))
2169 : {
2170 3920 : JoinExpr *j = (JoinExpr *) jtnode;
2171 3920 : bool save_need_phvs = context->need_phvs;
2172 :
2173 3920 : if (j == lowest_nulling_outer_join)
2174 : {
2175 : /* no more PHVs in or below this join */
2176 1210 : context->need_phvs = false;
2177 1210 : lowest_nulling_outer_join = NULL;
2178 : }
2179 3920 : replace_vars_in_jointree(j->larg, context, lowest_nulling_outer_join);
2180 3920 : replace_vars_in_jointree(j->rarg, context, lowest_nulling_outer_join);
2181 :
2182 : /*
2183 : * Use PHVs within the join quals of a full join, even when it's the
2184 : * lowest nulling outer join. Otherwise, we cannot identify which
2185 : * side of the join a pulled-up var-free expression came from, which
2186 : * can lead to failure to make a plan at all because none of the quals
2187 : * appear to be mergeable or hashable conditions. For this purpose we
2188 : * don't care about the state of wrap_non_vars, so leave it alone.
2189 : */
2190 3920 : if (j->jointype == JOIN_FULL)
2191 384 : context->need_phvs = true;
2192 :
2193 3920 : j->quals = pullup_replace_vars(j->quals, context);
2194 :
2195 : /*
2196 : * We don't bother to update the colvars list, since it won't be used
2197 : * again ...
2198 : */
2199 3920 : context->need_phvs = save_need_phvs;
2200 : }
2201 : else
2202 0 : elog(ERROR, "unrecognized node type: %d",
2203 : (int) nodeTag(jtnode));
2204 : }
2205 :
2206 : /*
2207 : * Apply pullup variable replacement throughout an expression tree
2208 : *
2209 : * Returns a modified copy of the tree, so this can't be used where we
2210 : * need to do in-place replacement.
2211 : */
2212 : static Node *
2213 181894 : pullup_replace_vars(Node *expr, pullup_replace_vars_context *context)
2214 : {
2215 181894 : return replace_rte_variables(expr,
2216 : context->varno, 0,
2217 : pullup_replace_vars_callback,
2218 : (void *) context,
2219 : context->outer_hasSubLinks);
2220 : }
2221 :
2222 : static Node *
2223 145536 : pullup_replace_vars_callback(Var *var,
2224 : replace_rte_variables_context *context)
2225 : {
2226 145536 : pullup_replace_vars_context *rcon = (pullup_replace_vars_context *) context->callback_arg;
2227 145536 : int varattno = var->varattno;
2228 : Node *newnode;
2229 :
2230 : /*
2231 : * If PlaceHolderVars are needed, we cache the modified expressions in
2232 : * rcon->rv_cache[]. This is not in hopes of any material speed gain
2233 : * within this function, but to avoid generating identical PHVs with
2234 : * different IDs. That would result in duplicate evaluations at runtime,
2235 : * and possibly prevent optimizations that rely on recognizing different
2236 : * references to the same subquery output as being equal(). So it's worth
2237 : * a bit of extra effort to avoid it.
2238 : */
2239 145536 : if (rcon->need_phvs &&
2240 7020 : varattno >= InvalidAttrNumber &&
2241 7020 : varattno <= list_length(rcon->targetlist) &&
2242 7020 : rcon->rv_cache[varattno] != NULL)
2243 : {
2244 : /* Just copy the entry and fall through to adjust its varlevelsup */
2245 3920 : newnode = copyObject(rcon->rv_cache[varattno]);
2246 : }
2247 141616 : else if (varattno == InvalidAttrNumber)
2248 : {
2249 : /* Must expand whole-tuple reference into RowExpr */
2250 : RowExpr *rowexpr;
2251 : List *colnames;
2252 : List *fields;
2253 276 : bool save_need_phvs = rcon->need_phvs;
2254 276 : int save_sublevelsup = context->sublevels_up;
2255 :
2256 : /*
2257 : * If generating an expansion for a var of a named rowtype (ie, this
2258 : * is a plain relation RTE), then we must include dummy items for
2259 : * dropped columns. If the var is RECORD (ie, this is a JOIN), then
2260 : * omit dropped columns. Either way, attach column names to the
2261 : * RowExpr for use of ruleutils.c.
2262 : *
2263 : * In order to be able to cache the results, we always generate the
2264 : * expansion with varlevelsup = 0, and then adjust if needed.
2265 : */
2266 552 : expandRTE(rcon->target_rte,
2267 276 : var->varno, 0 /* not varlevelsup */ , var->location,
2268 276 : (var->vartype != RECORDOID),
2269 : &colnames, &fields);
2270 : /* Adjust the generated per-field Vars, but don't insert PHVs */
2271 276 : rcon->need_phvs = false;
2272 276 : context->sublevels_up = 0; /* to match the expandRTE output */
2273 276 : fields = (List *) replace_rte_variables_mutator((Node *) fields,
2274 : context);
2275 276 : rcon->need_phvs = save_need_phvs;
2276 276 : context->sublevels_up = save_sublevelsup;
2277 :
2278 276 : rowexpr = makeNode(RowExpr);
2279 276 : rowexpr->args = fields;
2280 276 : rowexpr->row_typeid = var->vartype;
2281 276 : rowexpr->row_format = COERCE_IMPLICIT_CAST;
2282 276 : rowexpr->colnames = colnames;
2283 276 : rowexpr->location = var->location;
2284 276 : newnode = (Node *) rowexpr;
2285 :
2286 : /*
2287 : * Insert PlaceHolderVar if needed. Notice that we are wrapping one
2288 : * PlaceHolderVar around the whole RowExpr, rather than putting one
2289 : * around each element of the row. This is because we need the
2290 : * expression to yield NULL, not ROW(NULL,NULL,...) when it is forced
2291 : * to null by an outer join.
2292 : */
2293 276 : if (rcon->need_phvs)
2294 : {
2295 : /* RowExpr is certainly not strict, so always need PHV */
2296 : newnode = (Node *)
2297 8 : make_placeholder_expr(rcon->root,
2298 : (Expr *) newnode,
2299 : bms_make_singleton(rcon->varno));
2300 : /* cache it with the PHV, and with varlevelsup still zero */
2301 8 : rcon->rv_cache[InvalidAttrNumber] = copyObject(newnode);
2302 : }
2303 : }
2304 : else
2305 : {
2306 : /* Normal case referencing one targetlist element */
2307 141340 : TargetEntry *tle = get_tle_by_resno(rcon->targetlist, varattno);
2308 :
2309 141340 : if (tle == NULL) /* shouldn't happen */
2310 0 : elog(ERROR, "could not find attribute %d in subquery targetlist",
2311 : varattno);
2312 :
2313 : /* Make a copy of the tlist item to return */
2314 141340 : newnode = (Node *) copyObject(tle->expr);
2315 :
2316 : /* Insert PlaceHolderVar if needed */
2317 141340 : if (rcon->need_phvs)
2318 : {
2319 : bool wrap;
2320 :
2321 3092 : if (newnode && IsA(newnode, Var) &&
2322 2408 : ((Var *) newnode)->varlevelsup == 0)
2323 : {
2324 : /*
2325 : * Simple Vars always escape being wrapped, unless they are
2326 : * lateral references to something outside the subquery being
2327 : * pulled up. (Even then, we could omit the PlaceHolderVar if
2328 : * the referenced rel is under the same lowest outer join, but
2329 : * it doesn't seem worth the trouble to check that.)
2330 : */
2331 4808 : if (rcon->target_rte->lateral &&
2332 232 : !bms_is_member(((Var *) newnode)->varno, rcon->relids))
2333 16 : wrap = true;
2334 : else
2335 2388 : wrap = false;
2336 : }
2337 688 : else if (newnode && IsA(newnode, PlaceHolderVar) &&
2338 28 : ((PlaceHolderVar *) newnode)->phlevelsup == 0)
2339 : {
2340 : /* No need to wrap a PlaceHolderVar with another one, either */
2341 28 : wrap = false;
2342 : }
2343 660 : else if (rcon->wrap_non_vars)
2344 : {
2345 : /* Wrap all non-Vars in a PlaceHolderVar */
2346 64 : wrap = true;
2347 : }
2348 : else
2349 : {
2350 : /*
2351 : * If it contains a Var of the subquery being pulled up, and
2352 : * does not contain any non-strict constructs, then it's
2353 : * certainly nullable so we don't need to insert a
2354 : * PlaceHolderVar.
2355 : *
2356 : * This analysis could be tighter: in particular, a non-strict
2357 : * construct hidden within a lower-level PlaceHolderVar is not
2358 : * reason to add another PHV. But for now it doesn't seem
2359 : * worth the code to be more exact.
2360 : *
2361 : * Note: in future maybe we should insert a PlaceHolderVar
2362 : * anyway, if the tlist item is expensive to evaluate?
2363 : *
2364 : * For a LATERAL subquery, we have to check the actual var
2365 : * membership of the node, but if it's non-lateral then any
2366 : * level-zero var must belong to the subquery.
2367 : */
2368 660 : if ((rcon->target_rte->lateral ?
2369 64 : bms_overlap(pull_varnos((Node *) newnode), rcon->relids) :
2370 532 : contain_vars_of_level((Node *) newnode, 0)) &&
2371 176 : !contain_nonstrict_functions((Node *) newnode))
2372 : {
2373 : /* No wrap needed */
2374 0 : wrap = false;
2375 : }
2376 : else
2377 : {
2378 : /* Else wrap it in a PlaceHolderVar */
2379 596 : wrap = true;
2380 : }
2381 : }
2382 :
2383 3092 : if (wrap)
2384 : newnode = (Node *)
2385 676 : make_placeholder_expr(rcon->root,
2386 : (Expr *) newnode,
2387 : bms_make_singleton(rcon->varno));
2388 :
2389 : /*
2390 : * Cache it if possible (ie, if the attno is in range, which it
2391 : * probably always should be). We can cache the value even if we
2392 : * decided we didn't need a PHV, since this result will be
2393 : * suitable for any request that has need_phvs.
2394 : */
2395 6184 : if (varattno > InvalidAttrNumber &&
2396 3092 : varattno <= list_length(rcon->targetlist))
2397 3092 : rcon->rv_cache[varattno] = copyObject(newnode);
2398 : }
2399 : }
2400 :
2401 : /* Must adjust varlevelsup if tlist item is from higher query */
2402 145536 : if (var->varlevelsup > 0)
2403 426 : IncrementVarSublevelsUp(newnode, var->varlevelsup, 0);
2404 :
2405 145536 : return newnode;
2406 : }
2407 :
2408 : /*
2409 : * Apply pullup variable replacement to a subquery
2410 : *
2411 : * This needs to be different from pullup_replace_vars() because
2412 : * replace_rte_variables will think that it shouldn't increment sublevels_up
2413 : * before entering the Query; so we need to call it with sublevels_up == 1.
2414 : */
2415 : static Query *
2416 248 : pullup_replace_vars_subquery(Query *query,
2417 : pullup_replace_vars_context *context)
2418 : {
2419 : Assert(IsA(query, Query));
2420 248 : return (Query *) replace_rte_variables((Node *) query,
2421 : context->varno, 1,
2422 : pullup_replace_vars_callback,
2423 : (void *) context,
2424 : NULL);
2425 : }
2426 :
2427 :
2428 : /*
2429 : * flatten_simple_union_all
2430 : * Try to optimize top-level UNION ALL structure into an appendrel
2431 : *
2432 : * If a query's setOperations tree consists entirely of simple UNION ALL
2433 : * operations, flatten it into an append relation, which we can process more
2434 : * intelligently than the general setops case. Otherwise, do nothing.
2435 : *
2436 : * In most cases, this can succeed only for a top-level query, because for a
2437 : * subquery in FROM, the parent query's invocation of pull_up_subqueries would
2438 : * already have flattened the UNION via pull_up_simple_union_all. But there
2439 : * are a few cases we can support here but not in that code path, for example
2440 : * when the subquery also contains ORDER BY.
2441 : */
2442 : void
2443 2952 : flatten_simple_union_all(PlannerInfo *root)
2444 : {
2445 2952 : Query *parse = root->parse;
2446 : SetOperationStmt *topop;
2447 : Node *leftmostjtnode;
2448 : int leftmostRTI;
2449 : RangeTblEntry *leftmostRTE;
2450 : int childRTI;
2451 : RangeTblEntry *childRTE;
2452 : RangeTblRef *rtr;
2453 :
2454 : /* Shouldn't be called unless query has setops */
2455 2952 : topop = castNode(SetOperationStmt, parse->setOperations);
2456 : Assert(topop);
2457 :
2458 : /* Can't optimize away a recursive UNION */
2459 2952 : if (root->hasRecursion)
2460 346 : return;
2461 :
2462 : /*
2463 : * Recursively check the tree of set operations. If not all UNION ALL
2464 : * with identical column types, punt.
2465 : */
2466 2606 : if (!is_simple_union_all_recurse((Node *) topop, parse, topop->colTypes))
2467 1220 : return;
2468 :
2469 : /*
2470 : * Locate the leftmost leaf query in the setops tree. The upper query's
2471 : * Vars all refer to this RTE (see transformSetOperationStmt).
2472 : */
2473 1386 : leftmostjtnode = topop->larg;
2474 1436 : while (leftmostjtnode && IsA(leftmostjtnode, SetOperationStmt))
2475 50 : leftmostjtnode = ((SetOperationStmt *) leftmostjtnode)->larg;
2476 : Assert(leftmostjtnode && IsA(leftmostjtnode, RangeTblRef));
2477 1386 : leftmostRTI = ((RangeTblRef *) leftmostjtnode)->rtindex;
2478 1386 : leftmostRTE = rt_fetch(leftmostRTI, parse->rtable);
2479 : Assert(leftmostRTE->rtekind == RTE_SUBQUERY);
2480 :
2481 : /*
2482 : * Make a copy of the leftmost RTE and add it to the rtable. This copy
2483 : * will represent the leftmost leaf query in its capacity as a member of
2484 : * the appendrel. The original will represent the appendrel as a whole.
2485 : * (We must do things this way because the upper query's Vars have to be
2486 : * seen as referring to the whole appendrel.)
2487 : */
2488 1386 : childRTE = copyObject(leftmostRTE);
2489 1386 : parse->rtable = lappend(parse->rtable, childRTE);
2490 1386 : childRTI = list_length(parse->rtable);
2491 :
2492 : /* Modify the setops tree to reference the child copy */
2493 1386 : ((RangeTblRef *) leftmostjtnode)->rtindex = childRTI;
2494 :
2495 : /* Modify the formerly-leftmost RTE to mark it as an appendrel parent */
2496 1386 : leftmostRTE->inh = true;
2497 :
2498 : /*
2499 : * Form a RangeTblRef for the appendrel, and insert it into FROM. The top
2500 : * Query of a setops tree should have had an empty FromClause initially.
2501 : */
2502 1386 : rtr = makeNode(RangeTblRef);
2503 1386 : rtr->rtindex = leftmostRTI;
2504 : Assert(parse->jointree->fromlist == NIL);
2505 1386 : parse->jointree->fromlist = list_make1(rtr);
2506 :
2507 : /*
2508 : * Now pretend the query has no setops. We must do this before trying to
2509 : * do subquery pullup, because of Assert in pull_up_simple_subquery.
2510 : */
2511 1386 : parse->setOperations = NULL;
2512 :
2513 : /*
2514 : * Build AppendRelInfo information, and apply pull_up_subqueries to the
2515 : * leaf queries of the UNION ALL. (We must do that now because they
2516 : * weren't previously referenced by the jointree, and so were missed by
2517 : * the main invocation of pull_up_subqueries.)
2518 : */
2519 1386 : pull_up_union_leaf_queries((Node *) topop, root, leftmostRTI, parse, 0);
2520 : }
2521 :
2522 :
2523 : /*
2524 : * reduce_outer_joins
2525 : * Attempt to reduce outer joins to plain inner joins.
2526 : *
2527 : * The idea here is that given a query like
2528 : * SELECT ... FROM a LEFT JOIN b ON (...) WHERE b.y = 42;
2529 : * we can reduce the LEFT JOIN to a plain JOIN if the "=" operator in WHERE
2530 : * is strict. The strict operator will always return NULL, causing the outer
2531 : * WHERE to fail, on any row where the LEFT JOIN filled in NULLs for b's
2532 : * columns. Therefore, there's no need for the join to produce null-extended
2533 : * rows in the first place --- which makes it a plain join not an outer join.
2534 : * (This scenario may not be very likely in a query written out by hand, but
2535 : * it's reasonably likely when pushing quals down into complex views.)
2536 : *
2537 : * More generally, an outer join can be reduced in strength if there is a
2538 : * strict qual above it in the qual tree that constrains a Var from the
2539 : * nullable side of the join to be non-null. (For FULL joins this applies
2540 : * to each side separately.)
2541 : *
2542 : * Another transformation we apply here is to recognize cases like
2543 : * SELECT ... FROM a LEFT JOIN b ON (a.x = b.y) WHERE b.y IS NULL;
2544 : * If the join clause is strict for b.y, then only null-extended rows could
2545 : * pass the upper WHERE, and we can conclude that what the query is really
2546 : * specifying is an anti-semijoin. We change the join type from JOIN_LEFT
2547 : * to JOIN_ANTI. The IS NULL clause then becomes redundant, and must be
2548 : * removed to prevent bogus selectivity calculations, but we leave it to
2549 : * distribute_qual_to_rels to get rid of such clauses.
2550 : *
2551 : * Also, we get rid of JOIN_RIGHT cases by flipping them around to become
2552 : * JOIN_LEFT. This saves some code here and in some later planner routines,
2553 : * but the main reason to do it is to not need to invent a JOIN_REVERSE_ANTI
2554 : * join type.
2555 : *
2556 : * To ease recognition of strict qual clauses, we require this routine to be
2557 : * run after expression preprocessing (i.e., qual canonicalization and JOIN
2558 : * alias-var expansion).
2559 : */
2560 : void
2561 30806 : reduce_outer_joins(PlannerInfo *root)
2562 : {
2563 : reduce_outer_joins_state *state;
2564 :
2565 : /*
2566 : * To avoid doing strictness checks on more quals than necessary, we want
2567 : * to stop descending the jointree as soon as there are no outer joins
2568 : * below our current point. This consideration forces a two-pass process.
2569 : * The first pass gathers information about which base rels appear below
2570 : * each side of each join clause, and about whether there are outer
2571 : * join(s) below each side of each join clause. The second pass examines
2572 : * qual clauses and changes join types as it descends the tree.
2573 : */
2574 30806 : state = reduce_outer_joins_pass1((Node *) root->parse->jointree);
2575 :
2576 : /* planner.c shouldn't have called me if no outer joins */
2577 30806 : if (state == NULL || !state->contains_outer)
2578 0 : elog(ERROR, "so where are the outer joins?");
2579 :
2580 30806 : reduce_outer_joins_pass2((Node *) root->parse->jointree,
2581 : state, root, NULL, NIL, NIL);
2582 30806 : }
2583 :
2584 : /*
2585 : * reduce_outer_joins_pass1 - phase 1 data collection
2586 : *
2587 : * Returns a state node describing the given jointree node.
2588 : */
2589 : static reduce_outer_joins_state *
2590 149948 : reduce_outer_joins_pass1(Node *jtnode)
2591 : {
2592 : reduce_outer_joins_state *result;
2593 :
2594 : result = (reduce_outer_joins_state *)
2595 149948 : palloc(sizeof(reduce_outer_joins_state));
2596 149948 : result->relids = NULL;
2597 149948 : result->contains_outer = false;
2598 149948 : result->sub_states = NIL;
2599 :
2600 149948 : if (jtnode == NULL)
2601 0 : return result;
2602 149948 : if (IsA(jtnode, RangeTblRef))
2603 : {
2604 75050 : int varno = ((RangeTblRef *) jtnode)->rtindex;
2605 :
2606 75050 : result->relids = bms_make_singleton(varno);
2607 : }
2608 74898 : else if (IsA(jtnode, FromExpr))
2609 : {
2610 31870 : FromExpr *f = (FromExpr *) jtnode;
2611 : ListCell *l;
2612 :
2613 64956 : foreach(l, f->fromlist)
2614 : {
2615 : reduce_outer_joins_state *sub_state;
2616 :
2617 33086 : sub_state = reduce_outer_joins_pass1(lfirst(l));
2618 66172 : result->relids = bms_add_members(result->relids,
2619 33086 : sub_state->relids);
2620 33086 : result->contains_outer |= sub_state->contains_outer;
2621 33086 : result->sub_states = lappend(result->sub_states, sub_state);
2622 : }
2623 : }
2624 43028 : else if (IsA(jtnode, JoinExpr))
2625 : {
2626 43028 : JoinExpr *j = (JoinExpr *) jtnode;
2627 : reduce_outer_joins_state *sub_state;
2628 :
2629 : /* join's own RT index is not wanted in result->relids */
2630 43028 : if (IS_OUTER_JOIN(j->jointype))
2631 36658 : result->contains_outer = true;
2632 :
2633 43028 : sub_state = reduce_outer_joins_pass1(j->larg);
2634 86056 : result->relids = bms_add_members(result->relids,
2635 43028 : sub_state->relids);
2636 43028 : result->contains_outer |= sub_state->contains_outer;
2637 43028 : result->sub_states = lappend(result->sub_states, sub_state);
2638 :
2639 43028 : sub_state = reduce_outer_joins_pass1(j->rarg);
2640 86056 : result->relids = bms_add_members(result->relids,
2641 43028 : sub_state->relids);
2642 43028 : result->contains_outer |= sub_state->contains_outer;
2643 43028 : result->sub_states = lappend(result->sub_states, sub_state);
2644 : }
2645 : else
2646 0 : elog(ERROR, "unrecognized node type: %d",
2647 : (int) nodeTag(jtnode));
2648 149948 : return result;
2649 : }
2650 :
2651 : /*
2652 : * reduce_outer_joins_pass2 - phase 2 processing
2653 : *
2654 : * jtnode: current jointree node
2655 : * state: state data collected by phase 1 for this node
2656 : * root: toplevel planner state
2657 : * nonnullable_rels: set of base relids forced non-null by upper quals
2658 : * nonnullable_vars: list of Vars forced non-null by upper quals
2659 : * forced_null_vars: list of Vars forced null by upper quals
2660 : */
2661 : static void
2662 68426 : reduce_outer_joins_pass2(Node *jtnode,
2663 : reduce_outer_joins_state *state,
2664 : PlannerInfo *root,
2665 : Relids nonnullable_rels,
2666 : List *nonnullable_vars,
2667 : List *forced_null_vars)
2668 : {
2669 : /*
2670 : * pass 2 should never descend as far as an empty subnode or base rel,
2671 : * because it's only called on subtrees marked as contains_outer.
2672 : */
2673 68426 : if (jtnode == NULL)
2674 0 : elog(ERROR, "reached empty jointree");
2675 68426 : if (IsA(jtnode, RangeTblRef))
2676 0 : elog(ERROR, "reached base rel");
2677 68426 : else if (IsA(jtnode, FromExpr))
2678 : {
2679 31426 : FromExpr *f = (FromExpr *) jtnode;
2680 : ListCell *l;
2681 : ListCell *s;
2682 : Relids pass_nonnullable_rels;
2683 : List *pass_nonnullable_vars;
2684 : List *pass_forced_null_vars;
2685 :
2686 : /* Scan quals to see if we can add any constraints */
2687 31426 : pass_nonnullable_rels = find_nonnullable_rels(f->quals);
2688 31426 : pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
2689 : nonnullable_rels);
2690 31426 : pass_nonnullable_vars = find_nonnullable_vars(f->quals);
2691 31426 : pass_nonnullable_vars = list_concat(pass_nonnullable_vars,
2692 : nonnullable_vars);
2693 31426 : pass_forced_null_vars = find_forced_null_vars(f->quals);
2694 31426 : pass_forced_null_vars = list_concat(pass_forced_null_vars,
2695 : forced_null_vars);
2696 : /* And recurse --- but only into interesting subtrees */
2697 : Assert(list_length(f->fromlist) == list_length(state->sub_states));
2698 63992 : forboth(l, f->fromlist, s, state->sub_states)
2699 : {
2700 32566 : reduce_outer_joins_state *sub_state = lfirst(s);
2701 :
2702 32566 : if (sub_state->contains_outer)
2703 31446 : reduce_outer_joins_pass2(lfirst(l), sub_state, root,
2704 : pass_nonnullable_rels,
2705 : pass_nonnullable_vars,
2706 : pass_forced_null_vars);
2707 : }
2708 31426 : bms_free(pass_nonnullable_rels);
2709 : /* can't so easily clean up var lists, unfortunately */
2710 : }
2711 37000 : else if (IsA(jtnode, JoinExpr))
2712 : {
2713 37000 : JoinExpr *j = (JoinExpr *) jtnode;
2714 37000 : int rtindex = j->rtindex;
2715 37000 : JoinType jointype = j->jointype;
2716 37000 : reduce_outer_joins_state *left_state = linitial(state->sub_states);
2717 37000 : reduce_outer_joins_state *right_state = lsecond(state->sub_states);
2718 37000 : List *local_nonnullable_vars = NIL;
2719 37000 : bool computed_local_nonnullable_vars = false;
2720 :
2721 : /* Can we simplify this join? */
2722 37000 : switch (jointype)
2723 : {
2724 334 : case JOIN_INNER:
2725 334 : break;
2726 35710 : case JOIN_LEFT:
2727 35710 : if (bms_overlap(nonnullable_rels, right_state->relids))
2728 714 : jointype = JOIN_INNER;
2729 35710 : break;
2730 172 : case JOIN_RIGHT:
2731 172 : if (bms_overlap(nonnullable_rels, left_state->relids))
2732 12 : jointype = JOIN_INNER;
2733 172 : break;
2734 590 : case JOIN_FULL:
2735 590 : if (bms_overlap(nonnullable_rels, left_state->relids))
2736 : {
2737 0 : if (bms_overlap(nonnullable_rels, right_state->relids))
2738 0 : jointype = JOIN_INNER;
2739 : else
2740 0 : jointype = JOIN_LEFT;
2741 : }
2742 : else
2743 : {
2744 590 : if (bms_overlap(nonnullable_rels, right_state->relids))
2745 12 : jointype = JOIN_RIGHT;
2746 : }
2747 590 : break;
2748 194 : case JOIN_SEMI:
2749 : case JOIN_ANTI:
2750 :
2751 : /*
2752 : * These could only have been introduced by pull_up_sublinks,
2753 : * so there's no way that upper quals could refer to their
2754 : * righthand sides, and no point in checking.
2755 : */
2756 194 : break;
2757 0 : default:
2758 0 : elog(ERROR, "unrecognized join type: %d",
2759 : (int) jointype);
2760 : break;
2761 : }
2762 :
2763 : /*
2764 : * Convert JOIN_RIGHT to JOIN_LEFT. Note that in the case where we
2765 : * reduced JOIN_FULL to JOIN_RIGHT, this will mean the JoinExpr no
2766 : * longer matches the internal ordering of any CoalesceExpr's built to
2767 : * represent merged join variables. We don't care about that at
2768 : * present, but be wary of it ...
2769 : */
2770 37000 : if (jointype == JOIN_RIGHT)
2771 : {
2772 : Node *tmparg;
2773 :
2774 172 : tmparg = j->larg;
2775 172 : j->larg = j->rarg;
2776 172 : j->rarg = tmparg;
2777 172 : jointype = JOIN_LEFT;
2778 172 : right_state = linitial(state->sub_states);
2779 172 : left_state = lsecond(state->sub_states);
2780 : }
2781 :
2782 : /*
2783 : * See if we can reduce JOIN_LEFT to JOIN_ANTI. This is the case if
2784 : * the join's own quals are strict for any var that was forced null by
2785 : * higher qual levels. NOTE: there are other ways that we could
2786 : * detect an anti-join, in particular if we were to check whether Vars
2787 : * coming from the RHS must be non-null because of table constraints.
2788 : * That seems complicated and expensive though (in particular, one
2789 : * would have to be wary of lower outer joins). For the moment this
2790 : * seems sufficient.
2791 : */
2792 37000 : if (jointype == JOIN_LEFT)
2793 : {
2794 : List *overlap;
2795 :
2796 35168 : local_nonnullable_vars = find_nonnullable_vars(j->quals);
2797 35168 : computed_local_nonnullable_vars = true;
2798 :
2799 : /*
2800 : * It's not sufficient to check whether local_nonnullable_vars and
2801 : * forced_null_vars overlap: we need to know if the overlap
2802 : * includes any RHS variables.
2803 : */
2804 35168 : overlap = list_intersection(local_nonnullable_vars,
2805 : forced_null_vars);
2806 35862 : if (overlap != NIL &&
2807 694 : bms_overlap(pull_varnos((Node *) overlap),
2808 694 : right_state->relids))
2809 678 : jointype = JOIN_ANTI;
2810 : }
2811 :
2812 : /* Apply the jointype change, if any, to both jointree node and RTE */
2813 37000 : if (rtindex && jointype != j->jointype)
2814 : {
2815 1576 : RangeTblEntry *rte = rt_fetch(rtindex, root->parse->rtable);
2816 :
2817 : Assert(rte->rtekind == RTE_JOIN);
2818 : Assert(rte->jointype == j->jointype);
2819 1576 : rte->jointype = jointype;
2820 : }
2821 37000 : j->jointype = jointype;
2822 :
2823 : /* Only recurse if there's more to do below here */
2824 37000 : if (left_state->contains_outer || right_state->contains_outer)
2825 : {
2826 : Relids local_nonnullable_rels;
2827 : List *local_forced_null_vars;
2828 : Relids pass_nonnullable_rels;
2829 : List *pass_nonnullable_vars;
2830 : List *pass_forced_null_vars;
2831 :
2832 : /*
2833 : * If this join is (now) inner, we can add any constraints its
2834 : * quals provide to those we got from above. But if it is outer,
2835 : * we can pass down the local constraints only into the nullable
2836 : * side, because an outer join never eliminates any rows from its
2837 : * non-nullable side. Also, there is no point in passing upper
2838 : * constraints into the nullable side, since if there were any
2839 : * we'd have been able to reduce the join. (In the case of upper
2840 : * forced-null constraints, we *must not* pass them into the
2841 : * nullable side --- they either applied here, or not.) The upshot
2842 : * is that we pass either the local or the upper constraints,
2843 : * never both, to the children of an outer join.
2844 : *
2845 : * Note that a SEMI join works like an inner join here: it's okay
2846 : * to pass down both local and upper constraints. (There can't be
2847 : * any upper constraints affecting its inner side, but it's not
2848 : * worth having a separate code path to avoid passing them.)
2849 : *
2850 : * At a FULL join we just punt and pass nothing down --- is it
2851 : * possible to be smarter?
2852 : */
2853 6158 : if (jointype != JOIN_FULL)
2854 : {
2855 6052 : local_nonnullable_rels = find_nonnullable_rels(j->quals);
2856 6052 : if (!computed_local_nonnullable_vars)
2857 666 : local_nonnullable_vars = find_nonnullable_vars(j->quals);
2858 6052 : local_forced_null_vars = find_forced_null_vars(j->quals);
2859 6052 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
2860 : {
2861 : /* OK to merge upper and local constraints */
2862 480 : local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
2863 : nonnullable_rels);
2864 480 : local_nonnullable_vars = list_concat(local_nonnullable_vars,
2865 : nonnullable_vars);
2866 480 : local_forced_null_vars = list_concat(local_forced_null_vars,
2867 : forced_null_vars);
2868 : }
2869 : }
2870 : else
2871 : {
2872 : /* no use in calculating these */
2873 106 : local_nonnullable_rels = NULL;
2874 106 : local_forced_null_vars = NIL;
2875 : }
2876 :
2877 6158 : if (left_state->contains_outer)
2878 : {
2879 5846 : if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
2880 : {
2881 : /* pass union of local and upper constraints */
2882 382 : pass_nonnullable_rels = local_nonnullable_rels;
2883 382 : pass_nonnullable_vars = local_nonnullable_vars;
2884 382 : pass_forced_null_vars = local_forced_null_vars;
2885 : }
2886 5464 : else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
2887 : {
2888 : /* can't pass local constraints to non-nullable side */
2889 5382 : pass_nonnullable_rels = nonnullable_rels;
2890 5382 : pass_nonnullable_vars = nonnullable_vars;
2891 5382 : pass_forced_null_vars = forced_null_vars;
2892 : }
2893 : else
2894 : {
2895 : /* no constraints pass through JOIN_FULL */
2896 82 : pass_nonnullable_rels = NULL;
2897 82 : pass_nonnullable_vars = NIL;
2898 82 : pass_forced_null_vars = NIL;
2899 : }
2900 5846 : reduce_outer_joins_pass2(j->larg, left_state, root,
2901 : pass_nonnullable_rels,
2902 : pass_nonnullable_vars,
2903 : pass_forced_null_vars);
2904 : }
2905 :
2906 6158 : if (right_state->contains_outer)
2907 : {
2908 328 : if (jointype != JOIN_FULL) /* ie, INNER/LEFT/SEMI/ANTI */
2909 : {
2910 : /* pass appropriate constraints, per comment above */
2911 304 : pass_nonnullable_rels = local_nonnullable_rels;
2912 304 : pass_nonnullable_vars = local_nonnullable_vars;
2913 304 : pass_forced_null_vars = local_forced_null_vars;
2914 : }
2915 : else
2916 : {
2917 : /* no constraints pass through JOIN_FULL */
2918 24 : pass_nonnullable_rels = NULL;
2919 24 : pass_nonnullable_vars = NIL;
2920 24 : pass_forced_null_vars = NIL;
2921 : }
2922 328 : reduce_outer_joins_pass2(j->rarg, right_state, root,
2923 : pass_nonnullable_rels,
2924 : pass_nonnullable_vars,
2925 : pass_forced_null_vars);
2926 : }
2927 6158 : bms_free(local_nonnullable_rels);
2928 : }
2929 : }
2930 : else
2931 0 : elog(ERROR, "unrecognized node type: %d",
2932 : (int) nodeTag(jtnode));
2933 68426 : }
2934 :
2935 :
2936 : /*
2937 : * remove_useless_result_rtes
2938 : * Attempt to remove RTE_RESULT RTEs from the join tree.
2939 : *
2940 : * We can remove RTE_RESULT entries from the join tree using the knowledge
2941 : * that RTE_RESULT returns exactly one row and has no output columns. Hence,
2942 : * if one is inner-joined to anything else, we can delete it. Optimizations
2943 : * are also possible for some outer-join cases, as detailed below.
2944 : *
2945 : * Some of these optimizations depend on recognizing empty (constant-true)
2946 : * quals for FromExprs and JoinExprs. That makes it useful to apply this
2947 : * optimization pass after expression preprocessing, since that will have
2948 : * eliminated constant-true quals, allowing more cases to be recognized as
2949 : * optimizable. What's more, the usual reason for an RTE_RESULT to be present
2950 : * is that we pulled up a subquery or VALUES clause, thus very possibly
2951 : * replacing Vars with constants, making it more likely that a qual can be
2952 : * reduced to constant true. Also, because some optimizations depend on
2953 : * the outer-join type, it's best to have done reduce_outer_joins() first.
2954 : *
2955 : * A PlaceHolderVar referencing an RTE_RESULT RTE poses an obstacle to this
2956 : * process: we must remove the RTE_RESULT's relid from the PHV's phrels, but
2957 : * we must not reduce the phrels set to empty. If that would happen, and
2958 : * the RTE_RESULT is an immediate child of an outer join, we have to give up
2959 : * and not remove the RTE_RESULT: there is noplace else to evaluate the
2960 : * PlaceHolderVar. (That is, in such cases the RTE_RESULT *does* have output
2961 : * columns.) But if the RTE_RESULT is an immediate child of an inner join,
2962 : * we can usually change the PlaceHolderVar's phrels so as to evaluate it at
2963 : * the inner join instead. This is OK because we really only care that PHVs
2964 : * are evaluated above or below the correct outer joins. We can't, however,
2965 : * postpone the evaluation of a PHV to above where it is used; so there are
2966 : * some checks below on whether output PHVs are laterally referenced in the
2967 : * other join input rel(s).
2968 : *
2969 : * We used to try to do this work as part of pull_up_subqueries() where the
2970 : * potentially-optimizable cases get introduced; but it's way simpler, and
2971 : * more effective, to do it separately.
2972 : */
2973 : void
2974 121320 : remove_useless_result_rtes(PlannerInfo *root)
2975 : {
2976 : ListCell *cell;
2977 :
2978 : /* Top level of jointree must always be a FromExpr */
2979 : Assert(IsA(root->parse->jointree, FromExpr));
2980 : /* Recurse ... */
2981 242640 : root->parse->jointree = (FromExpr *)
2982 121320 : remove_useless_results_recurse(root, (Node *) root->parse->jointree);
2983 : /* We should still have a FromExpr */
2984 : Assert(IsA(root->parse->jointree, FromExpr));
2985 :
2986 : /*
2987 : * Remove any PlanRowMark referencing an RTE_RESULT RTE. We obviously
2988 : * must do that for any RTE_RESULT that we just removed. But one for a
2989 : * RTE that we did not remove can be dropped anyway: since the RTE has
2990 : * only one possible output row, there is no need for EPQ to mark and
2991 : * restore that row.
2992 : *
2993 : * It's necessary, not optional, to remove the PlanRowMark for a surviving
2994 : * RTE_RESULT RTE; otherwise we'll generate a whole-row Var for the
2995 : * RTE_RESULT, which the executor has no support for.
2996 : */
2997 121344 : foreach(cell, root->rowMarks)
2998 : {
2999 24 : PlanRowMark *rc = (PlanRowMark *) lfirst(cell);
3000 :
3001 24 : if (rt_fetch(rc->rti, root->parse->rtable)->rtekind == RTE_RESULT)
3002 16 : root->rowMarks = foreach_delete_current(root->rowMarks, cell);
3003 : }
3004 121320 : }
3005 :
3006 : /*
3007 : * remove_useless_results_recurse
3008 : * Recursive guts of remove_useless_result_rtes.
3009 : *
3010 : * This recursively processes the jointree and returns a modified jointree.
3011 : */
3012 : static Node *
3013 244354 : remove_useless_results_recurse(PlannerInfo *root, Node *jtnode)
3014 : {
3015 : Assert(jtnode != NULL);
3016 244354 : if (IsA(jtnode, RangeTblRef))
3017 : {
3018 : /* Can't immediately do anything with a RangeTblRef */
3019 : }
3020 122158 : else if (IsA(jtnode, FromExpr))
3021 : {
3022 121592 : FromExpr *f = (FromExpr *) jtnode;
3023 121592 : Relids result_relids = NULL;
3024 : ListCell *cell;
3025 :
3026 : /*
3027 : * We can drop RTE_RESULT rels from the fromlist so long as at least
3028 : * one child remains, since joining to a one-row table changes
3029 : * nothing. (But we can't drop a RTE_RESULT that computes PHV(s) that
3030 : * are needed by some sibling. The cleanup transformation below would
3031 : * reassign the PHVs to be computed at the join, which is too late for
3032 : * the sibling's use.) The easiest way to mechanize this rule is to
3033 : * modify the list in-place.
3034 : */
3035 243494 : foreach(cell, f->fromlist)
3036 : {
3037 121902 : Node *child = (Node *) lfirst(cell);
3038 : int varno;
3039 :
3040 : /* Recursively transform child ... */
3041 121902 : child = remove_useless_results_recurse(root, child);
3042 : /* ... and stick it back into the tree */
3043 121902 : lfirst(cell) = child;
3044 :
3045 : /*
3046 : * If it's an RTE_RESULT with at least one sibling, and no sibling
3047 : * references dependent PHVs, we can drop it. We don't yet know
3048 : * what the inner join's final relid set will be, so postpone
3049 : * cleanup of PHVs etc till after this loop.
3050 : */
3051 122394 : if (list_length(f->fromlist) > 1 &&
3052 492 : (varno = get_result_relid(root, child)) != 0 &&
3053 112 : !find_dependent_phvs_in_jointree(root, (Node *) f, varno))
3054 : {
3055 104 : f->fromlist = foreach_delete_current(f->fromlist, cell);
3056 104 : result_relids = bms_add_member(result_relids, varno);
3057 : }
3058 : }
3059 :
3060 : /*
3061 : * Clean up if we dropped any RTE_RESULT RTEs. This is a bit
3062 : * inefficient if there's more than one, but it seems better to
3063 : * optimize the support code for the single-relid case.
3064 : */
3065 121592 : if (result_relids)
3066 : {
3067 104 : int varno = -1;
3068 :
3069 208 : while ((varno = bms_next_member(result_relids, varno)) >= 0)
3070 104 : remove_result_refs(root, varno, (Node *) f);
3071 : }
3072 :
3073 : /*
3074 : * If we're not at the top of the jointree, it's valid to simplify a
3075 : * degenerate FromExpr into its single child. (At the top, we must
3076 : * keep the FromExpr since Query.jointree is required to point to a
3077 : * FromExpr.)
3078 : */
3079 121592 : if (f != root->parse->jointree &&
3080 280 : f->quals == NULL &&
3081 8 : list_length(f->fromlist) == 1)
3082 8 : return (Node *) linitial(f->fromlist);
3083 : }
3084 566 : else if (IsA(jtnode, JoinExpr))
3085 : {
3086 566 : JoinExpr *j = (JoinExpr *) jtnode;
3087 : int varno;
3088 :
3089 : /* First, recurse */
3090 566 : j->larg = remove_useless_results_recurse(root, j->larg);
3091 566 : j->rarg = remove_useless_results_recurse(root, j->rarg);
3092 :
3093 : /* Apply join-type-specific optimization rules */
3094 566 : switch (j->jointype)
3095 : {
3096 146 : case JOIN_INNER:
3097 :
3098 : /*
3099 : * An inner join is equivalent to a FromExpr, so if either
3100 : * side was simplified to an RTE_RESULT rel, we can replace
3101 : * the join with a FromExpr with just the other side; and if
3102 : * the qual is empty (JOIN ON TRUE) then we can omit the
3103 : * FromExpr as well.
3104 : *
3105 : * Just as in the FromExpr case, we can't simplify if the
3106 : * other input rel references any PHVs that are marked as to
3107 : * be evaluated at the RTE_RESULT rel, because we can't
3108 : * postpone their evaluation in that case. But we only have
3109 : * to check this in cases where it's syntactically legal for
3110 : * the other input to have a LATERAL reference to the
3111 : * RTE_RESULT rel. Only RHSes of inner and left joins are
3112 : * allowed to have such refs.
3113 : */
3114 146 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
3115 22 : !find_dependent_phvs_in_jointree(root, j->rarg, varno))
3116 : {
3117 22 : remove_result_refs(root, varno, j->rarg);
3118 44 : if (j->quals)
3119 : jtnode = (Node *)
3120 8 : makeFromExpr(list_make1(j->rarg), j->quals);
3121 : else
3122 14 : jtnode = j->rarg;
3123 : }
3124 124 : else if ((varno = get_result_relid(root, j->rarg)) != 0)
3125 : {
3126 58 : remove_result_refs(root, varno, j->larg);
3127 58 : if (j->quals)
3128 : jtnode = (Node *)
3129 46 : makeFromExpr(list_make1(j->larg), j->quals);
3130 : else
3131 12 : jtnode = j->larg;
3132 : }
3133 146 : break;
3134 152 : case JOIN_LEFT:
3135 :
3136 : /*
3137 : * We can simplify this case if the RHS is an RTE_RESULT, with
3138 : * two different possibilities:
3139 : *
3140 : * If the qual is empty (JOIN ON TRUE), then the join can be
3141 : * strength-reduced to a plain inner join, since each LHS row
3142 : * necessarily has exactly one join partner. So we can always
3143 : * discard the RHS, much as in the JOIN_INNER case above.
3144 : * (Again, the LHS could not contain a lateral reference to
3145 : * the RHS.)
3146 : *
3147 : * Otherwise, it's still true that each LHS row should be
3148 : * returned exactly once, and since the RHS returns no columns
3149 : * (unless there are PHVs that have to be evaluated there), we
3150 : * don't much care if it's null-extended or not. So in this
3151 : * case also, we can just ignore the qual and discard the left
3152 : * join.
3153 : */
3154 152 : if ((varno = get_result_relid(root, j->rarg)) != 0 &&
3155 24 : (j->quals == NULL ||
3156 16 : !find_dependent_phvs(root, varno)))
3157 : {
3158 8 : remove_result_refs(root, varno, j->larg);
3159 8 : jtnode = j->larg;
3160 : }
3161 152 : break;
3162 0 : case JOIN_RIGHT:
3163 : /* Mirror-image of the JOIN_LEFT case */
3164 0 : if ((varno = get_result_relid(root, j->larg)) != 0 &&
3165 0 : (j->quals == NULL ||
3166 0 : !find_dependent_phvs(root, varno)))
3167 : {
3168 0 : remove_result_refs(root, varno, j->rarg);
3169 0 : jtnode = j->rarg;
3170 : }
3171 0 : break;
3172 256 : case JOIN_SEMI:
3173 :
3174 : /*
3175 : * We may simplify this case if the RHS is an RTE_RESULT; the
3176 : * join qual becomes effectively just a filter qual for the
3177 : * LHS, since we should either return the LHS row or not. For
3178 : * simplicity we inject the filter qual into a new FromExpr.
3179 : *
3180 : * Unlike the LEFT/RIGHT cases, we just Assert that there are
3181 : * no PHVs that need to be evaluated at the semijoin's RHS,
3182 : * since the rest of the query couldn't reference any outputs
3183 : * of the semijoin's RHS.
3184 : */
3185 256 : if ((varno = get_result_relid(root, j->rarg)) != 0)
3186 : {
3187 : Assert(!find_dependent_phvs(root, varno));
3188 4 : remove_result_refs(root, varno, j->larg);
3189 4 : if (j->quals)
3190 : jtnode = (Node *)
3191 4 : makeFromExpr(list_make1(j->larg), j->quals);
3192 : else
3193 0 : jtnode = j->larg;
3194 : }
3195 256 : break;
3196 12 : case JOIN_FULL:
3197 : case JOIN_ANTI:
3198 : /* We have no special smarts for these cases */
3199 12 : break;
3200 0 : default:
3201 0 : elog(ERROR, "unrecognized join type: %d",
3202 : (int) j->jointype);
3203 : break;
3204 : }
3205 : }
3206 : else
3207 0 : elog(ERROR, "unrecognized node type: %d",
3208 : (int) nodeTag(jtnode));
3209 244346 : return jtnode;
3210 : }
3211 :
3212 : /*
3213 : * get_result_relid
3214 : * If jtnode is a RangeTblRef for an RTE_RESULT RTE, return its relid;
3215 : * otherwise return 0.
3216 : */
3217 : static int
3218 1170 : get_result_relid(PlannerInfo *root, Node *jtnode)
3219 : {
3220 : int varno;
3221 :
3222 1170 : if (!IsA(jtnode, RangeTblRef))
3223 132 : return 0;
3224 1038 : varno = ((RangeTblRef *) jtnode)->rtindex;
3225 1038 : if (rt_fetch(varno, root->parse->rtable)->rtekind != RTE_RESULT)
3226 818 : return 0;
3227 220 : return varno;
3228 : }
3229 :
3230 : /*
3231 : * remove_result_refs
3232 : * Helper routine for dropping an unneeded RTE_RESULT RTE.
3233 : *
3234 : * This doesn't physically remove the RTE from the jointree, because that's
3235 : * more easily handled in remove_useless_results_recurse. What it does do
3236 : * is the necessary cleanup in the rest of the tree: we must adjust any PHVs
3237 : * that may reference the RTE. Be sure to call this at a point where the
3238 : * jointree is valid (no disconnected nodes).
3239 : *
3240 : * Note that we don't need to process the append_rel_list, since RTEs
3241 : * referenced directly in the jointree won't be appendrel members.
3242 : *
3243 : * varno is the RTE_RESULT's relid.
3244 : * newjtloc is the jointree location at which any PHVs referencing the
3245 : * RTE_RESULT should be evaluated instead.
3246 : */
3247 : static void
3248 196 : remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc)
3249 : {
3250 : /* Fix up PlaceHolderVars as needed */
3251 : /* If there are no PHVs anywhere, we can skip this bit */
3252 196 : if (root->glob->lastPHId != 0)
3253 : {
3254 : Relids subrelids;
3255 :
3256 44 : subrelids = get_relids_in_jointree(newjtloc, false);
3257 : Assert(!bms_is_empty(subrelids));
3258 44 : substitute_phv_relids((Node *) root->parse, varno, subrelids);
3259 : }
3260 :
3261 : /*
3262 : * We also need to remove any PlanRowMark referencing the RTE, but we
3263 : * postpone that work until we return to remove_useless_result_rtes.
3264 : */
3265 196 : }
3266 :
3267 :
3268 : /*
3269 : * find_dependent_phvs - are there any PlaceHolderVars whose relids are
3270 : * exactly the given varno?
3271 : *
3272 : * find_dependent_phvs should be used when we want to see if there are
3273 : * any such PHVs anywhere in the Query. Another use-case is to see if
3274 : * a subtree of the join tree contains such PHVs; but for that, we have
3275 : * to look not only at the join tree nodes themselves but at the
3276 : * referenced RTEs. For that, use find_dependent_phvs_in_jointree.
3277 : */
3278 :
3279 : typedef struct
3280 : {
3281 : Relids relids;
3282 : int sublevels_up;
3283 : } find_dependent_phvs_context;
3284 :
3285 : static bool
3286 440 : find_dependent_phvs_walker(Node *node,
3287 : find_dependent_phvs_context *context)
3288 : {
3289 440 : if (node == NULL)
3290 32 : return false;
3291 408 : if (IsA(node, PlaceHolderVar))
3292 : {
3293 44 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
3294 :
3295 88 : if (phv->phlevelsup == context->sublevels_up &&
3296 44 : bms_equal(context->relids, phv->phrels))
3297 24 : return true;
3298 : /* fall through to examine children */
3299 : }
3300 384 : if (IsA(node, Query))
3301 : {
3302 : /* Recurse into subselects */
3303 : bool result;
3304 :
3305 8 : context->sublevels_up++;
3306 8 : result = query_tree_walker((Query *) node,
3307 : find_dependent_phvs_walker,
3308 : (void *) context, 0);
3309 8 : context->sublevels_up--;
3310 8 : return result;
3311 : }
3312 : /* Shouldn't need to handle planner auxiliary nodes here */
3313 : Assert(!IsA(node, SpecialJoinInfo));
3314 : Assert(!IsA(node, AppendRelInfo));
3315 : Assert(!IsA(node, PlaceHolderInfo));
3316 : Assert(!IsA(node, MinMaxAggInfo));
3317 :
3318 376 : return expression_tree_walker(node, find_dependent_phvs_walker,
3319 : (void *) context);
3320 : }
3321 :
3322 : static bool
3323 16 : find_dependent_phvs(PlannerInfo *root, int varno)
3324 : {
3325 : find_dependent_phvs_context context;
3326 :
3327 : /* If there are no PHVs anywhere, we needn't work hard */
3328 16 : if (root->glob->lastPHId == 0)
3329 0 : return false;
3330 :
3331 16 : context.relids = bms_make_singleton(varno);
3332 16 : context.sublevels_up = 0;
3333 :
3334 16 : return query_tree_walker(root->parse,
3335 : find_dependent_phvs_walker,
3336 : (void *) &context,
3337 : 0);
3338 : }
3339 :
3340 : static bool
3341 134 : find_dependent_phvs_in_jointree(PlannerInfo *root, Node *node, int varno)
3342 : {
3343 : find_dependent_phvs_context context;
3344 : Relids subrelids;
3345 : int relid;
3346 :
3347 : /* If there are no PHVs anywhere, we needn't work hard */
3348 134 : if (root->glob->lastPHId == 0)
3349 106 : return false;
3350 :
3351 28 : context.relids = bms_make_singleton(varno);
3352 28 : context.sublevels_up = 0;
3353 :
3354 : /*
3355 : * See if the jointree fragment itself contains references (in join quals)
3356 : */
3357 28 : if (find_dependent_phvs_walker(node, &context))
3358 0 : return true;
3359 :
3360 : /*
3361 : * Otherwise, identify the set of referenced RTEs (we can ignore joins,
3362 : * since they should be flattened already, so their join alias lists no
3363 : * longer matter), and tediously check each RTE. We can ignore RTEs that
3364 : * are not marked LATERAL, though, since they couldn't possibly contain
3365 : * any cross-references to other RTEs.
3366 : */
3367 28 : subrelids = get_relids_in_jointree(node, false);
3368 28 : relid = -1;
3369 72 : while ((relid = bms_next_member(subrelids, relid)) >= 0)
3370 : {
3371 52 : RangeTblEntry *rte = rt_fetch(relid, root->parse->rtable);
3372 :
3373 60 : if (rte->lateral &&
3374 8 : range_table_entry_walker(rte,
3375 : find_dependent_phvs_walker,
3376 : (void *) &context,
3377 : 0))
3378 8 : return true;
3379 : }
3380 :
3381 20 : return false;
3382 : }
3383 :
3384 : /*
3385 : * substitute_phv_relids - adjust PlaceHolderVar relid sets after pulling up
3386 : * a subquery or removing an RTE_RESULT jointree item
3387 : *
3388 : * Find any PlaceHolderVar nodes in the given tree that reference the
3389 : * pulled-up relid, and change them to reference the replacement relid(s).
3390 : *
3391 : * NOTE: although this has the form of a walker, we cheat and modify the
3392 : * nodes in-place. This should be OK since the tree was copied by
3393 : * pullup_replace_vars earlier. Avoid scribbling on the original values of
3394 : * the bitmapsets, though, because expression_tree_mutator doesn't copy those.
3395 : */
3396 :
3397 : typedef struct
3398 : {
3399 : int varno;
3400 : int sublevels_up;
3401 : Relids subrelids;
3402 : } substitute_phv_relids_context;
3403 :
3404 : static bool
3405 1001130 : substitute_phv_relids_walker(Node *node,
3406 : substitute_phv_relids_context *context)
3407 : {
3408 1001130 : if (node == NULL)
3409 392716 : return false;
3410 608414 : if (IsA(node, PlaceHolderVar))
3411 : {
3412 2588 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
3413 :
3414 5160 : if (phv->phlevelsup == context->sublevels_up &&
3415 2572 : bms_is_member(context->varno, phv->phrels))
3416 : {
3417 3284 : phv->phrels = bms_union(phv->phrels,
3418 1642 : context->subrelids);
3419 1642 : phv->phrels = bms_del_member(phv->phrels,
3420 : context->varno);
3421 : /* Assert we haven't broken the PHV */
3422 : Assert(!bms_is_empty(phv->phrels));
3423 : }
3424 : /* fall through to examine children */
3425 : }
3426 608414 : if (IsA(node, Query))
3427 : {
3428 : /* Recurse into subselects */
3429 : bool result;
3430 :
3431 25872 : context->sublevels_up++;
3432 25872 : result = query_tree_walker((Query *) node,
3433 : substitute_phv_relids_walker,
3434 : (void *) context, 0);
3435 25872 : context->sublevels_up--;
3436 25872 : return result;
3437 : }
3438 : /* Shouldn't need to handle planner auxiliary nodes here */
3439 : Assert(!IsA(node, SpecialJoinInfo));
3440 : Assert(!IsA(node, AppendRelInfo));
3441 : Assert(!IsA(node, PlaceHolderInfo));
3442 : Assert(!IsA(node, MinMaxAggInfo));
3443 :
3444 582542 : return expression_tree_walker(node, substitute_phv_relids_walker,
3445 : (void *) context);
3446 : }
3447 :
3448 : static void
3449 9636 : substitute_phv_relids(Node *node, int varno, Relids subrelids)
3450 : {
3451 : substitute_phv_relids_context context;
3452 :
3453 9636 : context.varno = varno;
3454 9636 : context.sublevels_up = 0;
3455 9636 : context.subrelids = subrelids;
3456 :
3457 : /*
3458 : * Must be prepared to start with a Query or a bare expression tree.
3459 : */
3460 9636 : query_or_expression_tree_walker(node,
3461 : substitute_phv_relids_walker,
3462 : (void *) &context,
3463 : 0);
3464 9636 : }
3465 :
3466 : /*
3467 : * fix_append_rel_relids: update RT-index fields of AppendRelInfo nodes
3468 : *
3469 : * When we pull up a subquery, any AppendRelInfo references to the subquery's
3470 : * RT index have to be replaced by the substituted relid (and there had better
3471 : * be only one). We also need to apply substitute_phv_relids to their
3472 : * translated_vars lists, since those might contain PlaceHolderVars.
3473 : *
3474 : * We assume we may modify the AppendRelInfo nodes in-place.
3475 : */
3476 : static void
3477 6794 : fix_append_rel_relids(List *append_rel_list, int varno, Relids subrelids)
3478 : {
3479 : ListCell *l;
3480 6794 : int subvarno = -1;
3481 :
3482 : /*
3483 : * We only want to extract the member relid once, but we mustn't fail
3484 : * immediately if there are multiple members; it could be that none of the
3485 : * AppendRelInfo nodes refer to it. So compute it on first use. Note that
3486 : * bms_singleton_member will complain if set is not singleton.
3487 : */
3488 9592 : foreach(l, append_rel_list)
3489 : {
3490 2798 : AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
3491 :
3492 : /* The parent_relid shouldn't ever be a pullup target */
3493 : Assert(appinfo->parent_relid != varno);
3494 :
3495 2798 : if (appinfo->child_relid == varno)
3496 : {
3497 1526 : if (subvarno < 0)
3498 1526 : subvarno = bms_singleton_member(subrelids);
3499 1526 : appinfo->child_relid = subvarno;
3500 : }
3501 :
3502 : /* Also fix up any PHVs in its translated vars */
3503 2798 : substitute_phv_relids((Node *) appinfo->translated_vars,
3504 : varno, subrelids);
3505 : }
3506 6794 : }
3507 :
3508 : /*
3509 : * get_relids_in_jointree: get set of RT indexes present in a jointree
3510 : *
3511 : * If include_joins is true, join RT indexes are included; if false,
3512 : * only base rels are included.
3513 : */
3514 : Relids
3515 63086 : get_relids_in_jointree(Node *jtnode, bool include_joins)
3516 : {
3517 63086 : Relids result = NULL;
3518 :
3519 63086 : if (jtnode == NULL)
3520 0 : return result;
3521 63086 : if (IsA(jtnode, RangeTblRef))
3522 : {
3523 32002 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3524 :
3525 32002 : result = bms_make_singleton(varno);
3526 : }
3527 31084 : else if (IsA(jtnode, FromExpr))
3528 : {
3529 28904 : FromExpr *f = (FromExpr *) jtnode;
3530 : ListCell *l;
3531 :
3532 58762 : foreach(l, f->fromlist)
3533 : {
3534 29858 : result = bms_join(result,
3535 29858 : get_relids_in_jointree(lfirst(l),
3536 : include_joins));
3537 : }
3538 : }
3539 2180 : else if (IsA(jtnode, JoinExpr))
3540 : {
3541 2180 : JoinExpr *j = (JoinExpr *) jtnode;
3542 :
3543 2180 : result = get_relids_in_jointree(j->larg, include_joins);
3544 2180 : result = bms_join(result,
3545 : get_relids_in_jointree(j->rarg, include_joins));
3546 2180 : if (include_joins && j->rtindex)
3547 396 : result = bms_add_member(result, j->rtindex);
3548 : }
3549 : else
3550 0 : elog(ERROR, "unrecognized node type: %d",
3551 : (int) nodeTag(jtnode));
3552 63086 : return result;
3553 : }
3554 :
3555 : /*
3556 : * get_relids_for_join: get set of base RT indexes making up a join
3557 : */
3558 : Relids
3559 0 : get_relids_for_join(Query *query, int joinrelid)
3560 : {
3561 : Node *jtnode;
3562 :
3563 0 : jtnode = find_jointree_node_for_rel((Node *) query->jointree,
3564 : joinrelid);
3565 0 : if (!jtnode)
3566 0 : elog(ERROR, "could not find join node %d", joinrelid);
3567 0 : return get_relids_in_jointree(jtnode, false);
3568 : }
3569 :
3570 : /*
3571 : * find_jointree_node_for_rel: locate jointree node for a base or join RT index
3572 : *
3573 : * Returns NULL if not found
3574 : */
3575 : static Node *
3576 0 : find_jointree_node_for_rel(Node *jtnode, int relid)
3577 : {
3578 0 : if (jtnode == NULL)
3579 0 : return NULL;
3580 0 : if (IsA(jtnode, RangeTblRef))
3581 : {
3582 0 : int varno = ((RangeTblRef *) jtnode)->rtindex;
3583 :
3584 0 : if (relid == varno)
3585 0 : return jtnode;
3586 : }
3587 0 : else if (IsA(jtnode, FromExpr))
3588 : {
3589 0 : FromExpr *f = (FromExpr *) jtnode;
3590 : ListCell *l;
3591 :
3592 0 : foreach(l, f->fromlist)
3593 : {
3594 0 : jtnode = find_jointree_node_for_rel(lfirst(l), relid);
3595 0 : if (jtnode)
3596 0 : return jtnode;
3597 : }
3598 : }
3599 0 : else if (IsA(jtnode, JoinExpr))
3600 : {
3601 0 : JoinExpr *j = (JoinExpr *) jtnode;
3602 :
3603 0 : if (relid == j->rtindex)
3604 0 : return jtnode;
3605 0 : jtnode = find_jointree_node_for_rel(j->larg, relid);
3606 0 : if (jtnode)
3607 0 : return jtnode;
3608 0 : jtnode = find_jointree_node_for_rel(j->rarg, relid);
3609 0 : if (jtnode)
3610 0 : return jtnode;
3611 : }
3612 : else
3613 0 : elog(ERROR, "unrecognized node type: %d",
3614 : (int) nodeTag(jtnode));
3615 0 : return NULL;
3616 : }
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