Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * var.c
4 : * Var node manipulation routines
5 : *
6 : * Note: for most purposes, PlaceHolderVar is considered a Var too,
7 : * even if its contained expression is variable-free. Also, CurrentOfExpr
8 : * is treated as a Var for purposes of determining whether an expression
9 : * contains variables.
10 : *
11 : *
12 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
13 : * Portions Copyright (c) 1994, Regents of the University of California
14 : *
15 : *
16 : * IDENTIFICATION
17 : * src/backend/optimizer/util/var.c
18 : *
19 : *-------------------------------------------------------------------------
20 : */
21 : #include "postgres.h"
22 :
23 : #include "access/sysattr.h"
24 : #include "nodes/nodeFuncs.h"
25 : #include "optimizer/clauses.h"
26 : #include "optimizer/optimizer.h"
27 : #include "optimizer/placeholder.h"
28 : #include "optimizer/prep.h"
29 : #include "parser/parsetree.h"
30 : #include "rewrite/rewriteManip.h"
31 :
32 :
33 : typedef struct
34 : {
35 : Relids varnos;
36 : PlannerInfo *root;
37 : int sublevels_up;
38 : } pull_varnos_context;
39 :
40 : typedef struct
41 : {
42 : Bitmapset *varattnos;
43 : Index varno;
44 : } pull_varattnos_context;
45 :
46 : typedef struct
47 : {
48 : List *vars;
49 : int sublevels_up;
50 : } pull_vars_context;
51 :
52 : typedef struct
53 : {
54 : int var_location;
55 : int sublevels_up;
56 : } locate_var_of_level_context;
57 :
58 : typedef struct
59 : {
60 : List *varlist;
61 : int flags;
62 : } pull_var_clause_context;
63 :
64 : typedef struct
65 : {
66 : PlannerInfo *root; /* could be NULL! */
67 : Query *query; /* outer Query */
68 : int sublevels_up;
69 : bool possible_sublink; /* could aliases include a SubLink? */
70 : bool inserted_sublink; /* have we inserted a SubLink? */
71 : } flatten_join_alias_vars_context;
72 :
73 : static bool pull_varnos_walker(Node *node,
74 : pull_varnos_context *context);
75 : static bool pull_varattnos_walker(Node *node, pull_varattnos_context *context);
76 : static bool pull_vars_walker(Node *node, pull_vars_context *context);
77 : static bool contain_var_clause_walker(Node *node, void *context);
78 : static bool contain_vars_of_level_walker(Node *node, int *sublevels_up);
79 : static bool contain_vars_returning_old_or_new_walker(Node *node, void *context);
80 : static bool locate_var_of_level_walker(Node *node,
81 : locate_var_of_level_context *context);
82 : static bool pull_var_clause_walker(Node *node,
83 : pull_var_clause_context *context);
84 : static Node *flatten_join_alias_vars_mutator(Node *node,
85 : flatten_join_alias_vars_context *context);
86 : static Node *flatten_group_exprs_mutator(Node *node,
87 : flatten_join_alias_vars_context *context);
88 : static Node *mark_nullable_by_grouping(PlannerInfo *root, Node *newnode,
89 : Var *oldvar);
90 : static Node *add_nullingrels_if_needed(PlannerInfo *root, Node *newnode,
91 : Var *oldvar);
92 : static bool is_standard_join_alias_expression(Node *newnode, Var *oldvar);
93 : static void adjust_standard_join_alias_expression(Node *newnode, Var *oldvar);
94 : static Relids alias_relid_set(Query *query, Relids relids);
95 :
96 :
97 : /*
98 : * pull_varnos
99 : * Create a set of all the distinct varnos present in a parsetree.
100 : * Only varnos that reference level-zero rtable entries are considered.
101 : *
102 : * The result includes outer-join relids mentioned in Var.varnullingrels and
103 : * PlaceHolderVar.phnullingrels fields in the parsetree.
104 : *
105 : * "root" can be passed as NULL if it is not necessary to process
106 : * PlaceHolderVars.
107 : *
108 : * NOTE: this is used on not-yet-planned expressions. It may therefore find
109 : * bare SubLinks, and if so it needs to recurse into them to look for uplevel
110 : * references to the desired rtable level! But when we find a completed
111 : * SubPlan, we only need to look at the parameters passed to the subplan.
112 : */
113 : Relids
114 2649046 : pull_varnos(PlannerInfo *root, Node *node)
115 : {
116 : pull_varnos_context context;
117 :
118 2649046 : context.varnos = NULL;
119 2649046 : context.root = root;
120 2649046 : context.sublevels_up = 0;
121 :
122 : /*
123 : * Must be prepared to start with a Query or a bare expression tree; if
124 : * it's a Query, we don't want to increment sublevels_up.
125 : */
126 2649046 : query_or_expression_tree_walker(node,
127 : pull_varnos_walker,
128 : &context,
129 : 0);
130 :
131 2649046 : return context.varnos;
132 : }
133 :
134 : /*
135 : * pull_varnos_of_level
136 : * Create a set of all the distinct varnos present in a parsetree.
137 : * Only Vars of the specified level are considered.
138 : */
139 : Relids
140 7827 : pull_varnos_of_level(PlannerInfo *root, Node *node, int levelsup)
141 : {
142 : pull_varnos_context context;
143 :
144 7827 : context.varnos = NULL;
145 7827 : context.root = root;
146 7827 : context.sublevels_up = levelsup;
147 :
148 : /*
149 : * Must be prepared to start with a Query or a bare expression tree; if
150 : * it's a Query, we don't want to increment sublevels_up.
151 : */
152 7827 : query_or_expression_tree_walker(node,
153 : pull_varnos_walker,
154 : &context,
155 : 0);
156 :
157 7827 : return context.varnos;
158 : }
159 :
160 : static bool
161 4664954 : pull_varnos_walker(Node *node, pull_varnos_context *context)
162 : {
163 4664954 : if (node == NULL)
164 190414 : return false;
165 4474540 : if (IsA(node, Var))
166 : {
167 2237574 : Var *var = (Var *) node;
168 :
169 2237574 : if (var->varlevelsup == context->sublevels_up)
170 : {
171 2226988 : context->varnos = bms_add_member(context->varnos, var->varno);
172 2226988 : context->varnos = bms_add_members(context->varnos,
173 2226988 : var->varnullingrels);
174 : }
175 2237574 : return false;
176 : }
177 2236966 : if (IsA(node, CurrentOfExpr))
178 : {
179 660 : CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
180 :
181 660 : if (context->sublevels_up == 0)
182 660 : context->varnos = bms_add_member(context->varnos, cexpr->cvarno);
183 660 : return false;
184 : }
185 2236306 : if (IsA(node, PlaceHolderVar))
186 : {
187 4448 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
188 :
189 : /*
190 : * If a PlaceHolderVar is not of the target query level, ignore it,
191 : * instead recursing into its expression to see if it contains any
192 : * vars that are of the target level. We'll also do that when the
193 : * caller doesn't pass a "root" pointer. (We probably shouldn't see
194 : * PlaceHolderVars at all in such cases, but if we do, this is a
195 : * reasonable behavior.)
196 : */
197 4448 : if (phv->phlevelsup == context->sublevels_up &&
198 4448 : context->root != NULL)
199 : {
200 : /*
201 : * Ideally, the PHV's contribution to context->varnos is its
202 : * ph_eval_at set. However, this code can be invoked before
203 : * that's been computed. If we cannot find a PlaceHolderInfo,
204 : * fall back to the conservative assumption that the PHV will be
205 : * evaluated at its syntactic level (phv->phrels).
206 : *
207 : * Another problem is that a PlaceHolderVar can appear in quals or
208 : * tlists that have been translated for use in a child appendrel.
209 : * Typically such a PHV is a parameter expression sourced by some
210 : * other relation, so that the translation from parent appendrel
211 : * to child doesn't change its phrels, and we should still take
212 : * ph_eval_at at face value. But in corner cases, the PHV's
213 : * original phrels can include the parent appendrel itself, in
214 : * which case the translated PHV will have the child appendrel in
215 : * phrels, and we must translate ph_eval_at to match.
216 : */
217 4448 : PlaceHolderInfo *phinfo = NULL;
218 :
219 4448 : if (phv->phlevelsup == 0)
220 : {
221 4368 : if (phv->phid < context->root->placeholder_array_size)
222 3210 : phinfo = context->root->placeholder_array[phv->phid];
223 : }
224 4448 : if (phinfo == NULL)
225 : {
226 : /* No PlaceHolderInfo yet, use phrels */
227 1248 : context->varnos = bms_add_members(context->varnos,
228 1248 : phv->phrels);
229 : }
230 3200 : else if (bms_equal(phv->phrels, phinfo->ph_var->phrels))
231 : {
232 : /* Normal case: use ph_eval_at */
233 3050 : context->varnos = bms_add_members(context->varnos,
234 3050 : phinfo->ph_eval_at);
235 : }
236 : else
237 : {
238 : /* Translated PlaceHolderVar: translate ph_eval_at to match */
239 : Relids newevalat,
240 : delta;
241 :
242 : /* remove what was removed from phv->phrels ... */
243 150 : delta = bms_difference(phinfo->ph_var->phrels, phv->phrels);
244 150 : newevalat = bms_difference(phinfo->ph_eval_at, delta);
245 : /* ... then if that was in fact part of ph_eval_at ... */
246 150 : if (!bms_equal(newevalat, phinfo->ph_eval_at))
247 : {
248 : /* ... add what was added */
249 140 : delta = bms_difference(phv->phrels, phinfo->ph_var->phrels);
250 140 : newevalat = bms_join(newevalat, delta);
251 : }
252 150 : context->varnos = bms_join(context->varnos,
253 : newevalat);
254 : }
255 :
256 : /*
257 : * In all three cases, include phnullingrels in the result. We
258 : * don't worry about possibly needing to translate it, because
259 : * appendrels only translate varnos of baserels, not outer joins.
260 : */
261 8896 : context->varnos = bms_add_members(context->varnos,
262 4448 : phv->phnullingrels);
263 4448 : return false; /* don't recurse into expression */
264 : }
265 : }
266 2231858 : else if (IsA(node, Query))
267 : {
268 : /* Recurse into RTE subquery or not-yet-planned sublink subquery */
269 : bool result;
270 :
271 5973 : context->sublevels_up++;
272 5973 : result = query_tree_walker((Query *) node, pull_varnos_walker,
273 : context, 0);
274 5973 : context->sublevels_up--;
275 5973 : return result;
276 : }
277 2225885 : return expression_tree_walker(node, pull_varnos_walker, context);
278 : }
279 :
280 :
281 : /*
282 : * pull_varattnos
283 : * Find all the distinct attribute numbers present in an expression tree,
284 : * and add them to the initial contents of *varattnos.
285 : * Only Vars of the given varno and rtable level zero are considered.
286 : *
287 : * Attribute numbers are offset by FirstLowInvalidHeapAttributeNumber so that
288 : * we can include system attributes (e.g., OID) in the bitmap representation.
289 : *
290 : * Currently, this does not support unplanned subqueries; that is not needed
291 : * for current uses. It will handle already-planned SubPlan nodes, though,
292 : * looking into only the "testexpr" and the "args" list. (The subplan cannot
293 : * contain any other references to Vars of the current level.)
294 : */
295 : void
296 1318951 : pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
297 : {
298 : pull_varattnos_context context;
299 :
300 1318951 : context.varattnos = *varattnos;
301 1318951 : context.varno = varno;
302 :
303 1318951 : (void) pull_varattnos_walker(node, &context);
304 :
305 1318951 : *varattnos = context.varattnos;
306 1318951 : }
307 :
308 : static bool
309 4437437 : pull_varattnos_walker(Node *node, pull_varattnos_context *context)
310 : {
311 4437437 : if (node == NULL)
312 54946 : return false;
313 4382491 : if (IsA(node, Var))
314 : {
315 2534564 : Var *var = (Var *) node;
316 :
317 2534564 : if (var->varno == context->varno && var->varlevelsup == 0)
318 2534233 : context->varattnos =
319 2534233 : bms_add_member(context->varattnos,
320 2534233 : var->varattno - FirstLowInvalidHeapAttributeNumber);
321 2534564 : return false;
322 : }
323 :
324 : /* Should not find an unplanned subquery */
325 : Assert(!IsA(node, Query));
326 :
327 1847927 : return expression_tree_walker(node, pull_varattnos_walker, context);
328 : }
329 :
330 :
331 : /*
332 : * pull_vars_of_level
333 : * Create a list of all Vars (and PlaceHolderVars) referencing the
334 : * specified query level in the given parsetree.
335 : *
336 : * Caution: the Vars are not copied, only linked into the list.
337 : */
338 : List *
339 7099 : pull_vars_of_level(Node *node, int levelsup)
340 : {
341 : pull_vars_context context;
342 :
343 7099 : context.vars = NIL;
344 7099 : context.sublevels_up = levelsup;
345 :
346 : /*
347 : * Must be prepared to start with a Query or a bare expression tree; if
348 : * it's a Query, we don't want to increment sublevels_up.
349 : */
350 7099 : query_or_expression_tree_walker(node,
351 : pull_vars_walker,
352 : &context,
353 : 0);
354 :
355 7099 : return context.vars;
356 : }
357 :
358 : static bool
359 158382 : pull_vars_walker(Node *node, pull_vars_context *context)
360 : {
361 158382 : if (node == NULL)
362 36855 : return false;
363 121527 : if (IsA(node, Var))
364 : {
365 32724 : Var *var = (Var *) node;
366 :
367 32724 : if (var->varlevelsup == context->sublevels_up)
368 16734 : context->vars = lappend(context->vars, var);
369 32724 : return false;
370 : }
371 88803 : if (IsA(node, PlaceHolderVar))
372 : {
373 113 : PlaceHolderVar *phv = (PlaceHolderVar *) node;
374 :
375 113 : if (phv->phlevelsup == context->sublevels_up)
376 113 : context->vars = lappend(context->vars, phv);
377 : /* we don't want to look into the contained expression */
378 113 : return false;
379 : }
380 88690 : if (IsA(node, Query))
381 : {
382 : /* Recurse into RTE subquery or not-yet-planned sublink subquery */
383 : bool result;
384 :
385 1017 : context->sublevels_up++;
386 1017 : result = query_tree_walker((Query *) node, pull_vars_walker,
387 : context, 0);
388 1017 : context->sublevels_up--;
389 1017 : return result;
390 : }
391 87673 : return expression_tree_walker(node, pull_vars_walker, context);
392 : }
393 :
394 :
395 : /*
396 : * contain_var_clause
397 : * Recursively scan a clause to discover whether it contains any Var nodes
398 : * (of the current query level).
399 : *
400 : * Returns true if any varnode found.
401 : *
402 : * Does not examine subqueries, therefore must only be used after reduction
403 : * of sublinks to subplans!
404 : */
405 : bool
406 12423 : contain_var_clause(Node *node)
407 : {
408 12423 : return contain_var_clause_walker(node, NULL);
409 : }
410 :
411 : static bool
412 17431 : contain_var_clause_walker(Node *node, void *context)
413 : {
414 17431 : if (node == NULL)
415 80 : return false;
416 17351 : if (IsA(node, Var))
417 : {
418 2384 : if (((Var *) node)->varlevelsup == 0)
419 2384 : return true; /* abort the tree traversal and return true */
420 0 : return false;
421 : }
422 14967 : if (IsA(node, CurrentOfExpr))
423 0 : return true;
424 14967 : if (IsA(node, PlaceHolderVar))
425 : {
426 10 : if (((PlaceHolderVar *) node)->phlevelsup == 0)
427 10 : return true; /* abort the tree traversal and return true */
428 : /* else fall through to check the contained expr */
429 : }
430 14957 : return expression_tree_walker(node, contain_var_clause_walker, context);
431 : }
432 :
433 :
434 : /*
435 : * contain_vars_of_level
436 : * Recursively scan a clause to discover whether it contains any Var nodes
437 : * of the specified query level.
438 : *
439 : * Returns true if any such Var found.
440 : *
441 : * Will recurse into sublinks. Also, may be invoked directly on a Query.
442 : */
443 : bool
444 117572 : contain_vars_of_level(Node *node, int levelsup)
445 : {
446 117572 : int sublevels_up = levelsup;
447 :
448 117572 : return query_or_expression_tree_walker(node,
449 : contain_vars_of_level_walker,
450 : &sublevels_up,
451 : 0);
452 : }
453 :
454 : static bool
455 438035 : contain_vars_of_level_walker(Node *node, int *sublevels_up)
456 : {
457 438035 : if (node == NULL)
458 114871 : return false;
459 323164 : if (IsA(node, Var))
460 : {
461 57684 : if (((Var *) node)->varlevelsup == *sublevels_up)
462 36049 : return true; /* abort tree traversal and return true */
463 21635 : return false;
464 : }
465 265480 : if (IsA(node, CurrentOfExpr))
466 : {
467 152 : if (*sublevels_up == 0)
468 152 : return true;
469 0 : return false;
470 : }
471 265328 : if (IsA(node, PlaceHolderVar))
472 : {
473 65 : if (((PlaceHolderVar *) node)->phlevelsup == *sublevels_up)
474 65 : return true; /* abort the tree traversal and return true */
475 : /* else fall through to check the contained expr */
476 : }
477 265263 : if (IsA(node, Query))
478 : {
479 : /* Recurse into subselects */
480 : bool result;
481 :
482 454 : (*sublevels_up)++;
483 454 : result = query_tree_walker((Query *) node,
484 : contain_vars_of_level_walker,
485 : sublevels_up,
486 : 0);
487 454 : (*sublevels_up)--;
488 454 : return result;
489 : }
490 264809 : return expression_tree_walker(node,
491 : contain_vars_of_level_walker,
492 : sublevels_up);
493 : }
494 :
495 :
496 : /*
497 : * contain_vars_returning_old_or_new
498 : * Recursively scan a clause to discover whether it contains any Var nodes
499 : * (of the current query level) whose varreturningtype is VAR_RETURNING_OLD
500 : * or VAR_RETURNING_NEW.
501 : *
502 : * Returns true if any found.
503 : *
504 : * Any ReturningExprs are also detected --- if an OLD/NEW Var was rewritten,
505 : * we still regard this as a clause that returns OLD/NEW values.
506 : *
507 : * Does not examine subqueries, therefore must only be used after reduction
508 : * of sublinks to subplans!
509 : */
510 : bool
511 202 : contain_vars_returning_old_or_new(Node *node)
512 : {
513 202 : return contain_vars_returning_old_or_new_walker(node, NULL);
514 : }
515 :
516 : static bool
517 614 : contain_vars_returning_old_or_new_walker(Node *node, void *context)
518 : {
519 614 : if (node == NULL)
520 144 : return false;
521 470 : if (IsA(node, Var))
522 : {
523 201 : if (((Var *) node)->varlevelsup == 0 &&
524 201 : ((Var *) node)->varreturningtype != VAR_RETURNING_DEFAULT)
525 7 : return true; /* abort the tree traversal and return true */
526 194 : return false;
527 : }
528 269 : if (IsA(node, ReturningExpr))
529 : {
530 0 : if (((ReturningExpr *) node)->retlevelsup == 0)
531 0 : return true; /* abort the tree traversal and return true */
532 0 : return false;
533 : }
534 269 : return expression_tree_walker(node, contain_vars_returning_old_or_new_walker,
535 : context);
536 : }
537 :
538 :
539 : /*
540 : * locate_var_of_level
541 : * Find the parse location of any Var of the specified query level.
542 : *
543 : * Returns -1 if no such Var is in the querytree, or if they all have
544 : * unknown parse location. (The former case is probably caller error,
545 : * but we don't bother to distinguish it from the latter case.)
546 : *
547 : * Will recurse into sublinks. Also, may be invoked directly on a Query.
548 : *
549 : * Note: it might seem appropriate to merge this functionality into
550 : * contain_vars_of_level, but that would complicate that function's API.
551 : * Currently, the only uses of this function are for error reporting,
552 : * and so shaving cycles probably isn't very important.
553 : */
554 : int
555 8 : locate_var_of_level(Node *node, int levelsup)
556 : {
557 : locate_var_of_level_context context;
558 :
559 8 : context.var_location = -1; /* in case we find nothing */
560 8 : context.sublevels_up = levelsup;
561 :
562 8 : (void) query_or_expression_tree_walker(node,
563 : locate_var_of_level_walker,
564 : &context,
565 : 0);
566 :
567 8 : return context.var_location;
568 : }
569 :
570 : static bool
571 20 : locate_var_of_level_walker(Node *node,
572 : locate_var_of_level_context *context)
573 : {
574 20 : if (node == NULL)
575 0 : return false;
576 20 : if (IsA(node, Var))
577 : {
578 8 : Var *var = (Var *) node;
579 :
580 8 : if (var->varlevelsup == context->sublevels_up &&
581 8 : var->location >= 0)
582 : {
583 8 : context->var_location = var->location;
584 8 : return true; /* abort tree traversal and return true */
585 : }
586 0 : return false;
587 : }
588 12 : if (IsA(node, CurrentOfExpr))
589 : {
590 : /* since CurrentOfExpr doesn't carry location, nothing we can do */
591 0 : return false;
592 : }
593 : /* No extra code needed for PlaceHolderVar; just look in contained expr */
594 12 : if (IsA(node, Query))
595 : {
596 : /* Recurse into subselects */
597 : bool result;
598 :
599 0 : context->sublevels_up++;
600 0 : result = query_tree_walker((Query *) node,
601 : locate_var_of_level_walker,
602 : context,
603 : 0);
604 0 : context->sublevels_up--;
605 0 : return result;
606 : }
607 12 : return expression_tree_walker(node,
608 : locate_var_of_level_walker,
609 : context);
610 : }
611 :
612 :
613 : /*
614 : * pull_var_clause
615 : * Recursively pulls all Var nodes from an expression clause.
616 : *
617 : * Aggrefs are handled according to these bits in 'flags':
618 : * PVC_INCLUDE_AGGREGATES include Aggrefs in output list
619 : * PVC_RECURSE_AGGREGATES recurse into Aggref arguments
620 : * neither flag throw error if Aggref found
621 : * Vars within an Aggref's expression are included in the result only
622 : * when PVC_RECURSE_AGGREGATES is specified.
623 : *
624 : * WindowFuncs are handled according to these bits in 'flags':
625 : * PVC_INCLUDE_WINDOWFUNCS include WindowFuncs in output list
626 : * PVC_RECURSE_WINDOWFUNCS recurse into WindowFunc arguments
627 : * neither flag throw error if WindowFunc found
628 : * Vars within a WindowFunc's expression are included in the result only
629 : * when PVC_RECURSE_WINDOWFUNCS is specified.
630 : *
631 : * PlaceHolderVars are handled according to these bits in 'flags':
632 : * PVC_INCLUDE_PLACEHOLDERS include PlaceHolderVars in output list
633 : * PVC_RECURSE_PLACEHOLDERS recurse into PlaceHolderVar arguments
634 : * neither flag throw error if PlaceHolderVar found
635 : * Vars within a PHV's expression are included in the result only
636 : * when PVC_RECURSE_PLACEHOLDERS is specified.
637 : *
638 : * GroupingFuncs are treated exactly like Aggrefs, and so do not need
639 : * their own flag bits.
640 : *
641 : * CurrentOfExpr nodes are ignored in all cases.
642 : *
643 : * Upper-level vars (with varlevelsup > 0) should not be seen here,
644 : * likewise for upper-level Aggrefs and PlaceHolderVars.
645 : *
646 : * Returns list of nodes found. Note the nodes themselves are not
647 : * copied, only referenced.
648 : *
649 : * Does not examine subqueries, therefore must only be used after reduction
650 : * of sublinks to subplans!
651 : */
652 : List *
653 669425 : pull_var_clause(Node *node, int flags)
654 : {
655 : pull_var_clause_context context;
656 :
657 : /* Assert that caller has not specified inconsistent flags */
658 : Assert((flags & (PVC_INCLUDE_AGGREGATES | PVC_RECURSE_AGGREGATES))
659 : != (PVC_INCLUDE_AGGREGATES | PVC_RECURSE_AGGREGATES));
660 : Assert((flags & (PVC_INCLUDE_WINDOWFUNCS | PVC_RECURSE_WINDOWFUNCS))
661 : != (PVC_INCLUDE_WINDOWFUNCS | PVC_RECURSE_WINDOWFUNCS));
662 : Assert((flags & (PVC_INCLUDE_PLACEHOLDERS | PVC_RECURSE_PLACEHOLDERS))
663 : != (PVC_INCLUDE_PLACEHOLDERS | PVC_RECURSE_PLACEHOLDERS));
664 :
665 669425 : context.varlist = NIL;
666 669425 : context.flags = flags;
667 :
668 669425 : pull_var_clause_walker(node, &context);
669 669425 : return context.varlist;
670 : }
671 :
672 : static bool
673 3862375 : pull_var_clause_walker(Node *node, pull_var_clause_context *context)
674 : {
675 3862375 : if (node == NULL)
676 160805 : return false;
677 3701570 : if (IsA(node, Var))
678 : {
679 1433906 : if (((Var *) node)->varlevelsup != 0)
680 0 : elog(ERROR, "Upper-level Var found where not expected");
681 1433906 : context->varlist = lappend(context->varlist, node);
682 1433906 : return false;
683 : }
684 2267664 : else if (IsA(node, Aggref))
685 : {
686 85945 : if (((Aggref *) node)->agglevelsup != 0)
687 0 : elog(ERROR, "Upper-level Aggref found where not expected");
688 85945 : if (context->flags & PVC_INCLUDE_AGGREGATES)
689 : {
690 6758 : context->varlist = lappend(context->varlist, node);
691 : /* we do NOT descend into the contained expression */
692 6758 : return false;
693 : }
694 79187 : else if (context->flags & PVC_RECURSE_AGGREGATES)
695 : {
696 : /* fall through to recurse into the aggregate's arguments */
697 : }
698 : else
699 0 : elog(ERROR, "Aggref found where not expected");
700 : }
701 2181719 : else if (IsA(node, GroupingFunc))
702 : {
703 557 : if (((GroupingFunc *) node)->agglevelsup != 0)
704 0 : elog(ERROR, "Upper-level GROUPING found where not expected");
705 557 : if (context->flags & PVC_INCLUDE_AGGREGATES)
706 : {
707 2 : context->varlist = lappend(context->varlist, node);
708 : /* we do NOT descend into the contained expression */
709 2 : return false;
710 : }
711 555 : else if (context->flags & PVC_RECURSE_AGGREGATES)
712 : {
713 : /* fall through to recurse into the GroupingFunc's arguments */
714 : }
715 : else
716 0 : elog(ERROR, "GROUPING found where not expected");
717 : }
718 2181162 : else if (IsA(node, WindowFunc))
719 : {
720 : /* WindowFuncs have no levelsup field to check ... */
721 6287 : if (context->flags & PVC_INCLUDE_WINDOWFUNCS)
722 : {
723 62 : context->varlist = lappend(context->varlist, node);
724 : /* we do NOT descend into the contained expressions */
725 62 : return false;
726 : }
727 6225 : else if (context->flags & PVC_RECURSE_WINDOWFUNCS)
728 : {
729 : /* fall through to recurse into the windowfunc's arguments */
730 : }
731 : else
732 0 : elog(ERROR, "WindowFunc found where not expected");
733 : }
734 2174875 : else if (IsA(node, PlaceHolderVar))
735 : {
736 5577 : if (((PlaceHolderVar *) node)->phlevelsup != 0)
737 0 : elog(ERROR, "Upper-level PlaceHolderVar found where not expected");
738 5577 : if (context->flags & PVC_INCLUDE_PLACEHOLDERS)
739 : {
740 4257 : context->varlist = lappend(context->varlist, node);
741 : /* we do NOT descend into the contained expression */
742 4257 : return false;
743 : }
744 1320 : else if (context->flags & PVC_RECURSE_PLACEHOLDERS)
745 : {
746 : /* fall through to recurse into the placeholder's expression */
747 : }
748 : else
749 0 : elog(ERROR, "PlaceHolderVar found where not expected");
750 : }
751 2256585 : return expression_tree_walker(node, pull_var_clause_walker, context);
752 : }
753 :
754 :
755 : /*
756 : * flatten_join_alias_vars
757 : * Replace Vars that reference JOIN outputs with references to the original
758 : * relation variables instead. This allows quals involving such vars to be
759 : * pushed down. Whole-row Vars that reference JOIN relations are expanded
760 : * into RowExpr constructs that name the individual output Vars. This
761 : * is necessary since we will not scan the JOIN as a base relation, which
762 : * is the only way that the executor can directly handle whole-row Vars.
763 : *
764 : * This also adjusts relid sets found in some expression node types to
765 : * substitute the contained base+OJ rels for any join relid.
766 : *
767 : * If a JOIN contains sub-selects that have been flattened, its join alias
768 : * entries might now be arbitrary expressions, not just Vars. This affects
769 : * this function in two important ways. First, we might find ourselves
770 : * inserting SubLink expressions into subqueries, and we must make sure that
771 : * their Query.hasSubLinks fields get set to true if so. If there are any
772 : * SubLinks in the join alias lists, the outer Query should already have
773 : * hasSubLinks = true, so this is only relevant to un-flattened subqueries.
774 : * Second, we have to preserve any varnullingrels info attached to the
775 : * alias Vars we're replacing. If the replacement expression is a Var or
776 : * PlaceHolderVar or constructed from those, we can just add the
777 : * varnullingrels bits to the existing nullingrels field(s); otherwise
778 : * we have to add a PlaceHolderVar wrapper.
779 : */
780 : Node *
781 196907 : flatten_join_alias_vars(PlannerInfo *root, Query *query, Node *node)
782 : {
783 : flatten_join_alias_vars_context context;
784 :
785 : /*
786 : * We do not expect this to be applied to the whole Query, only to
787 : * expressions or LATERAL subqueries. Hence, if the top node is a Query,
788 : * it's okay to immediately increment sublevels_up.
789 : */
790 : Assert(node != (Node *) query);
791 :
792 196907 : context.root = root;
793 196907 : context.query = query;
794 196907 : context.sublevels_up = 0;
795 : /* flag whether join aliases could possibly contain SubLinks */
796 196907 : context.possible_sublink = query->hasSubLinks;
797 : /* if hasSubLinks is already true, no need to work hard */
798 196907 : context.inserted_sublink = query->hasSubLinks;
799 :
800 196907 : return flatten_join_alias_vars_mutator(node, &context);
801 : }
802 :
803 : /*
804 : * flatten_join_alias_for_parser
805 : *
806 : * This variant of flatten_join_alias_vars is used by the parser, to expand
807 : * join alias Vars before checking GROUP BY validity. In that case we lack
808 : * a root structure. Fortunately, we'd only need the root for making
809 : * PlaceHolderVars. We can avoid making PlaceHolderVars in the parser's
810 : * usage because it won't be dealing with arbitrary expressions: so long as
811 : * adjust_standard_join_alias_expression can handle everything the parser
812 : * would make as a join alias expression, we're OK.
813 : *
814 : * The "node" might be part of a sub-query of the Query whose join alias
815 : * Vars are to be expanded. "sublevels_up" indicates how far below the
816 : * given query we are starting.
817 : */
818 : Node *
819 3815 : flatten_join_alias_for_parser(Query *query, Node *node, int sublevels_up)
820 : {
821 : flatten_join_alias_vars_context context;
822 :
823 : /*
824 : * We do not expect this to be applied to the whole Query, only to
825 : * expressions or LATERAL subqueries. Hence, if the top node is a Query,
826 : * it's okay to immediately increment sublevels_up.
827 : */
828 : Assert(node != (Node *) query);
829 :
830 3815 : context.root = NULL;
831 3815 : context.query = query;
832 3815 : context.sublevels_up = sublevels_up;
833 : /* flag whether join aliases could possibly contain SubLinks */
834 3815 : context.possible_sublink = query->hasSubLinks;
835 : /* if hasSubLinks is already true, no need to work hard */
836 3815 : context.inserted_sublink = query->hasSubLinks;
837 :
838 3815 : return flatten_join_alias_vars_mutator(node, &context);
839 : }
840 :
841 : static Node *
842 2842632 : flatten_join_alias_vars_mutator(Node *node,
843 : flatten_join_alias_vars_context *context)
844 : {
845 2842632 : if (node == NULL)
846 252846 : return NULL;
847 2589786 : if (IsA(node, Var))
848 : {
849 765015 : Var *var = (Var *) node;
850 : RangeTblEntry *rte;
851 : Node *newvar;
852 :
853 : /* No change unless Var belongs to a JOIN of the target level */
854 765015 : if (var->varlevelsup != context->sublevels_up)
855 43052 : return node; /* no need to copy, really */
856 721963 : rte = rt_fetch(var->varno, context->query->rtable);
857 721963 : if (rte->rtekind != RTE_JOIN)
858 721419 : return node;
859 544 : if (var->varattno == InvalidAttrNumber)
860 : {
861 : /* Must expand whole-row reference */
862 : RowExpr *rowexpr;
863 5 : List *fields = NIL;
864 5 : List *colnames = NIL;
865 : ListCell *lv;
866 : ListCell *ln;
867 :
868 : Assert(list_length(rte->joinaliasvars) == list_length(rte->eref->colnames));
869 40 : forboth(lv, rte->joinaliasvars, ln, rte->eref->colnames)
870 : {
871 35 : newvar = (Node *) lfirst(lv);
872 : /* Ignore dropped columns */
873 35 : if (newvar == NULL)
874 0 : continue;
875 35 : newvar = copyObject(newvar);
876 :
877 : /*
878 : * If we are expanding an alias carried down from an upper
879 : * query, must adjust its varlevelsup fields.
880 : */
881 35 : if (context->sublevels_up != 0)
882 0 : IncrementVarSublevelsUp(newvar, context->sublevels_up, 0);
883 : /* Preserve original Var's location, if possible */
884 35 : if (IsA(newvar, Var))
885 35 : ((Var *) newvar)->location = var->location;
886 : /* Recurse in case join input is itself a join */
887 : /* (also takes care of setting inserted_sublink if needed) */
888 35 : newvar = flatten_join_alias_vars_mutator(newvar, context);
889 35 : fields = lappend(fields, newvar);
890 : /* We need the names of non-dropped columns, too */
891 35 : colnames = lappend(colnames, copyObject((Node *) lfirst(ln)));
892 : }
893 5 : rowexpr = makeNode(RowExpr);
894 5 : rowexpr->args = fields;
895 5 : rowexpr->row_typeid = var->vartype;
896 5 : rowexpr->row_format = COERCE_IMPLICIT_CAST;
897 : /* vartype will always be RECORDOID, so we always need colnames */
898 5 : rowexpr->colnames = colnames;
899 5 : rowexpr->location = var->location;
900 :
901 : /* Lastly, add any varnullingrels to the replacement expression */
902 5 : return add_nullingrels_if_needed(context->root, (Node *) rowexpr,
903 : var);
904 : }
905 :
906 : /* Expand join alias reference */
907 : Assert(var->varattno > 0);
908 539 : newvar = (Node *) list_nth(rte->joinaliasvars, var->varattno - 1);
909 : Assert(newvar != NULL);
910 539 : newvar = copyObject(newvar);
911 :
912 : /*
913 : * If we are expanding an alias carried down from an upper query, must
914 : * adjust its varlevelsup fields.
915 : */
916 539 : if (context->sublevels_up != 0)
917 28 : IncrementVarSublevelsUp(newvar, context->sublevels_up, 0);
918 :
919 : /* Preserve original Var's location, if possible */
920 539 : if (IsA(newvar, Var))
921 0 : ((Var *) newvar)->location = var->location;
922 :
923 : /* Recurse in case join input is itself a join */
924 539 : newvar = flatten_join_alias_vars_mutator(newvar, context);
925 :
926 : /* Detect if we are adding a sublink to query */
927 539 : if (context->possible_sublink && !context->inserted_sublink)
928 20 : context->inserted_sublink = checkExprHasSubLink(newvar);
929 :
930 : /* Lastly, add any varnullingrels to the replacement expression */
931 539 : return add_nullingrels_if_needed(context->root, newvar, var);
932 : }
933 1824771 : if (IsA(node, PlaceHolderVar))
934 : {
935 : /* Copy the PlaceHolderVar node with correct mutation of subnodes */
936 : PlaceHolderVar *phv;
937 :
938 1810 : phv = (PlaceHolderVar *) expression_tree_mutator(node,
939 : flatten_join_alias_vars_mutator,
940 : context);
941 : /* now fix PlaceHolderVar's relid sets */
942 1810 : if (phv->phlevelsup == context->sublevels_up)
943 : {
944 1730 : phv->phrels = alias_relid_set(context->query,
945 : phv->phrels);
946 : /* we *don't* change phnullingrels */
947 : }
948 1810 : return (Node *) phv;
949 : }
950 :
951 1822961 : if (IsA(node, Query))
952 : {
953 : /* Recurse into RTE subquery or not-yet-planned sublink subquery */
954 : Query *newnode;
955 : bool save_inserted_sublink;
956 :
957 12555 : context->sublevels_up++;
958 12555 : save_inserted_sublink = context->inserted_sublink;
959 12555 : context->inserted_sublink = ((Query *) node)->hasSubLinks;
960 12555 : newnode = query_tree_mutator((Query *) node,
961 : flatten_join_alias_vars_mutator,
962 : context,
963 : QTW_IGNORE_JOINALIASES);
964 12555 : newnode->hasSubLinks |= context->inserted_sublink;
965 12555 : context->inserted_sublink = save_inserted_sublink;
966 12555 : context->sublevels_up--;
967 12555 : return (Node *) newnode;
968 : }
969 : /* Already-planned tree not supported */
970 : Assert(!IsA(node, SubPlan));
971 : Assert(!IsA(node, AlternativeSubPlan));
972 : /* Shouldn't need to handle these planner auxiliary nodes here */
973 : Assert(!IsA(node, SpecialJoinInfo));
974 : Assert(!IsA(node, PlaceHolderInfo));
975 : Assert(!IsA(node, MinMaxAggInfo));
976 :
977 1810406 : return expression_tree_mutator(node, flatten_join_alias_vars_mutator, context);
978 : }
979 :
980 : /*
981 : * flatten_group_exprs
982 : * Replace Vars that reference GROUP outputs with the underlying grouping
983 : * expressions.
984 : *
985 : * We have to preserve any varnullingrels info attached to the group Vars we're
986 : * replacing. If the replacement expression is a Var or PlaceHolderVar or
987 : * constructed from those, we can just add the varnullingrels bits to the
988 : * existing nullingrels field(s); otherwise we have to add a PlaceHolderVar
989 : * wrapper.
990 : *
991 : * NOTE: root may be passed as NULL, which is why we have to pass the Query
992 : * separately. We need the root itself only for preserving varnullingrels.
993 : * Callers can safely pass NULL if preserving varnullingrels is unnecessary for
994 : * their specific use case (e.g., deparsing source text, or scanning for
995 : * volatile functions), or if it is already guaranteed that the query cannot
996 : * contain grouping sets.
997 : */
998 : Node *
999 8693 : flatten_group_exprs(PlannerInfo *root, Query *query, Node *node)
1000 : {
1001 : flatten_join_alias_vars_context context;
1002 :
1003 : /*
1004 : * We do not expect this to be applied to the whole Query, only to
1005 : * expressions or LATERAL subqueries. Hence, if the top node is a Query,
1006 : * it's okay to immediately increment sublevels_up.
1007 : */
1008 : Assert(node != (Node *) query);
1009 :
1010 8693 : context.root = root;
1011 8693 : context.query = query;
1012 8693 : context.sublevels_up = 0;
1013 : /* flag whether grouping expressions could possibly contain SubLinks */
1014 8693 : context.possible_sublink = query->hasSubLinks;
1015 : /* if hasSubLinks is already true, no need to work hard */
1016 8693 : context.inserted_sublink = query->hasSubLinks;
1017 :
1018 8693 : return flatten_group_exprs_mutator(node, &context);
1019 : }
1020 :
1021 : static Node *
1022 84720 : flatten_group_exprs_mutator(Node *node,
1023 : flatten_join_alias_vars_context *context)
1024 : {
1025 84720 : if (node == NULL)
1026 9838 : return NULL;
1027 74882 : if (IsA(node, Var))
1028 : {
1029 14627 : Var *var = (Var *) node;
1030 : RangeTblEntry *rte;
1031 : Node *newvar;
1032 :
1033 : /* No change unless Var belongs to the GROUP of the target level */
1034 14627 : if (var->varlevelsup != context->sublevels_up)
1035 0 : return node; /* no need to copy, really */
1036 14627 : rte = rt_fetch(var->varno, context->query->rtable);
1037 14627 : if (rte->rtekind != RTE_GROUP)
1038 195 : return node;
1039 :
1040 : /* Expand group exprs reference */
1041 : Assert(var->varattno > 0);
1042 14432 : newvar = (Node *) list_nth(rte->groupexprs, var->varattno - 1);
1043 : Assert(newvar != NULL);
1044 14432 : newvar = copyObject(newvar);
1045 :
1046 : /*
1047 : * If we are expanding an expr carried down from an upper query, must
1048 : * adjust its varlevelsup fields.
1049 : */
1050 14432 : if (context->sublevels_up != 0)
1051 0 : IncrementVarSublevelsUp(newvar, context->sublevels_up, 0);
1052 :
1053 : /* Preserve original Var's location, if possible */
1054 14432 : if (IsA(newvar, Var))
1055 12326 : ((Var *) newvar)->location = var->location;
1056 :
1057 : /* Detect if we are adding a sublink to query */
1058 14432 : if (context->possible_sublink && !context->inserted_sublink)
1059 0 : context->inserted_sublink = checkExprHasSubLink(newvar);
1060 :
1061 : /* Lastly, add any varnullingrels to the replacement expression */
1062 14432 : return mark_nullable_by_grouping(context->root, newvar, var);
1063 : }
1064 :
1065 60255 : if (IsA(node, Aggref))
1066 : {
1067 5933 : Aggref *agg = (Aggref *) node;
1068 :
1069 5933 : if ((int) agg->agglevelsup == context->sublevels_up)
1070 : {
1071 : /*
1072 : * If we find an aggregate call of the original level, do not
1073 : * recurse into its normal arguments, ORDER BY arguments, or
1074 : * filter; there are no grouped vars there. But we should check
1075 : * direct arguments as though they weren't in an aggregate.
1076 : */
1077 5933 : agg = copyObject(agg);
1078 5933 : agg->aggdirectargs = (List *)
1079 5933 : flatten_group_exprs_mutator((Node *) agg->aggdirectargs, context);
1080 :
1081 5933 : return (Node *) agg;
1082 : }
1083 :
1084 : /*
1085 : * We can skip recursing into aggregates of higher levels altogether,
1086 : * since they could not possibly contain Vars of concern to us (see
1087 : * transformAggregateCall). We do need to look at aggregates of lower
1088 : * levels, however.
1089 : */
1090 0 : if ((int) agg->agglevelsup > context->sublevels_up)
1091 0 : return node;
1092 : }
1093 :
1094 54322 : if (IsA(node, GroupingFunc))
1095 : {
1096 307 : GroupingFunc *grp = (GroupingFunc *) node;
1097 :
1098 : /*
1099 : * If we find a GroupingFunc node of the original or higher level, do
1100 : * not recurse into its arguments; there are no grouped vars there.
1101 : */
1102 307 : if ((int) grp->agglevelsup >= context->sublevels_up)
1103 307 : return node;
1104 : }
1105 :
1106 54015 : if (IsA(node, Query))
1107 : {
1108 : /* Recurse into RTE subquery or not-yet-planned sublink subquery */
1109 : Query *newnode;
1110 : bool save_inserted_sublink;
1111 :
1112 0 : context->sublevels_up++;
1113 0 : save_inserted_sublink = context->inserted_sublink;
1114 0 : context->inserted_sublink = ((Query *) node)->hasSubLinks;
1115 0 : newnode = query_tree_mutator((Query *) node,
1116 : flatten_group_exprs_mutator,
1117 : context,
1118 : QTW_IGNORE_GROUPEXPRS);
1119 0 : newnode->hasSubLinks |= context->inserted_sublink;
1120 0 : context->inserted_sublink = save_inserted_sublink;
1121 0 : context->sublevels_up--;
1122 0 : return (Node *) newnode;
1123 : }
1124 :
1125 54015 : return expression_tree_mutator(node, flatten_group_exprs_mutator,
1126 : context);
1127 : }
1128 :
1129 : /*
1130 : * Add oldvar's varnullingrels, if any, to a flattened grouping expression.
1131 : * The newnode has been copied, so we can modify it freely.
1132 : */
1133 : static Node *
1134 14432 : mark_nullable_by_grouping(PlannerInfo *root, Node *newnode, Var *oldvar)
1135 : {
1136 : Relids relids;
1137 :
1138 14432 : if (root == NULL)
1139 6084 : return newnode;
1140 8348 : if (oldvar->varnullingrels == NULL)
1141 6661 : return newnode; /* nothing to do */
1142 :
1143 : Assert(bms_equal(oldvar->varnullingrels,
1144 : bms_make_singleton(root->group_rtindex)));
1145 :
1146 1687 : relids = pull_varnos_of_level(root, newnode, oldvar->varlevelsup);
1147 :
1148 1687 : if (!bms_is_empty(relids))
1149 : {
1150 : /*
1151 : * If the newnode is not variable-free, we set the nullingrels of Vars
1152 : * or PHVs that are contained in the expression. This is not really
1153 : * 'correct' in theory, because it is the whole expression that can be
1154 : * nullable by grouping sets, not its individual vars. But it works
1155 : * in practice, because what we need is that the expression can be
1156 : * somehow distinguished from the same expression in ECs, and marking
1157 : * its vars is sufficient for this purpose.
1158 : */
1159 1647 : newnode = add_nulling_relids(newnode,
1160 : relids,
1161 1647 : oldvar->varnullingrels);
1162 : }
1163 : else /* variable-free? */
1164 : {
1165 : /*
1166 : * If the newnode is variable-free and does not contain volatile
1167 : * functions or set-returning functions, it can be treated as a member
1168 : * of EC that is redundant. So wrap it in a new PlaceHolderVar to
1169 : * carry the nullingrels. Otherwise we do not bother to make any
1170 : * changes.
1171 : *
1172 : * Aggregate functions and window functions are not allowed in
1173 : * grouping expressions.
1174 : */
1175 : Assert(!contain_agg_clause(newnode));
1176 : Assert(!contain_window_function(newnode));
1177 :
1178 40 : if (!contain_volatile_functions(newnode) &&
1179 40 : !expression_returns_set(newnode))
1180 : {
1181 : PlaceHolderVar *newphv;
1182 : Relids phrels;
1183 :
1184 25 : phrels = get_relids_in_jointree((Node *) root->parse->jointree,
1185 : true, false);
1186 : Assert(!bms_is_empty(phrels));
1187 :
1188 25 : newphv = make_placeholder_expr(root, (Expr *) newnode, phrels);
1189 : /* newphv has zero phlevelsup and NULL phnullingrels; fix it */
1190 25 : newphv->phlevelsup = oldvar->varlevelsup;
1191 25 : newphv->phnullingrels = bms_copy(oldvar->varnullingrels);
1192 25 : newnode = (Node *) newphv;
1193 : }
1194 : }
1195 :
1196 1687 : return newnode;
1197 : }
1198 :
1199 : /*
1200 : * Add oldvar's varnullingrels, if any, to a flattened join alias expression.
1201 : * The newnode has been copied, so we can modify it freely.
1202 : */
1203 : static Node *
1204 544 : add_nullingrels_if_needed(PlannerInfo *root, Node *newnode, Var *oldvar)
1205 : {
1206 544 : if (oldvar->varnullingrels == NULL)
1207 418 : return newnode; /* nothing to do */
1208 : /* If possible, do it by adding to existing nullingrel fields */
1209 126 : if (is_standard_join_alias_expression(newnode, oldvar))
1210 116 : adjust_standard_join_alias_expression(newnode, oldvar);
1211 10 : else if (root)
1212 : {
1213 : /*
1214 : * We can insert a PlaceHolderVar to carry the nullingrels. However,
1215 : * deciding where to evaluate the PHV is slightly tricky. We first
1216 : * try to evaluate it at the natural semantic level of the new
1217 : * expression; but if that expression is variable-free, fall back to
1218 : * evaluating it at the join that the oldvar is an alias Var for.
1219 : */
1220 : PlaceHolderVar *newphv;
1221 10 : Index levelsup = oldvar->varlevelsup;
1222 10 : Relids phrels = pull_varnos_of_level(root, newnode, levelsup);
1223 :
1224 10 : if (bms_is_empty(phrels)) /* variable-free? */
1225 : {
1226 10 : if (levelsup != 0) /* this won't work otherwise */
1227 0 : elog(ERROR, "unsupported join alias expression");
1228 10 : phrels = get_relids_for_join(root->parse, oldvar->varno);
1229 : /* If it's an outer join, eval below not above the join */
1230 10 : phrels = bms_del_member(phrels, oldvar->varno);
1231 : Assert(!bms_is_empty(phrels));
1232 : }
1233 10 : newphv = make_placeholder_expr(root, (Expr *) newnode, phrels);
1234 : /* newphv has zero phlevelsup and NULL phnullingrels; fix it */
1235 10 : newphv->phlevelsup = levelsup;
1236 10 : newphv->phnullingrels = bms_copy(oldvar->varnullingrels);
1237 10 : newnode = (Node *) newphv;
1238 : }
1239 : else
1240 : {
1241 : /* ooops, we're missing support for something the parser can make */
1242 0 : elog(ERROR, "unsupported join alias expression");
1243 : }
1244 126 : return newnode;
1245 : }
1246 :
1247 : /*
1248 : * Check to see if we can insert nullingrels into this join alias expression
1249 : * without use of a separate PlaceHolderVar.
1250 : *
1251 : * This will handle Vars, PlaceHolderVars, and implicit-coercion and COALESCE
1252 : * expressions built from those. This coverage needs to handle anything
1253 : * that the parser would put into joinaliasvars.
1254 : */
1255 : static bool
1256 382 : is_standard_join_alias_expression(Node *newnode, Var *oldvar)
1257 : {
1258 382 : if (newnode == NULL)
1259 0 : return false;
1260 382 : if (IsA(newnode, Var) &&
1261 226 : ((Var *) newnode)->varlevelsup == oldvar->varlevelsup)
1262 226 : return true;
1263 156 : else if (IsA(newnode, PlaceHolderVar) &&
1264 0 : ((PlaceHolderVar *) newnode)->phlevelsup == oldvar->varlevelsup)
1265 0 : return true;
1266 156 : else if (IsA(newnode, FuncExpr))
1267 : {
1268 23 : FuncExpr *fexpr = (FuncExpr *) newnode;
1269 :
1270 : /*
1271 : * We need to assume that the function wouldn't produce non-NULL from
1272 : * NULL, which is reasonable for implicit coercions but otherwise not
1273 : * so much. (Looking at its strictness is likely overkill, and anyway
1274 : * it would cause us to fail if someone forgot to mark an implicit
1275 : * coercion as strict.)
1276 : */
1277 23 : if (fexpr->funcformat != COERCE_IMPLICIT_CAST ||
1278 23 : fexpr->args == NIL)
1279 0 : return false;
1280 :
1281 : /*
1282 : * Examine only the first argument --- coercions might have additional
1283 : * arguments that are constants.
1284 : */
1285 23 : return is_standard_join_alias_expression(linitial(fexpr->args), oldvar);
1286 : }
1287 133 : else if (IsA(newnode, RelabelType))
1288 : {
1289 13 : RelabelType *relabel = (RelabelType *) newnode;
1290 :
1291 : /* This definitely won't produce non-NULL from NULL */
1292 13 : return is_standard_join_alias_expression((Node *) relabel->arg, oldvar);
1293 : }
1294 120 : else if (IsA(newnode, CoerceViaIO))
1295 : {
1296 0 : CoerceViaIO *iocoerce = (CoerceViaIO *) newnode;
1297 :
1298 : /* This definitely won't produce non-NULL from NULL */
1299 0 : return is_standard_join_alias_expression((Node *) iocoerce->arg, oldvar);
1300 : }
1301 120 : else if (IsA(newnode, ArrayCoerceExpr))
1302 : {
1303 0 : ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) newnode;
1304 :
1305 : /* This definitely won't produce non-NULL from NULL (at array level) */
1306 0 : return is_standard_join_alias_expression((Node *) acoerce->arg, oldvar);
1307 : }
1308 120 : else if (IsA(newnode, CoalesceExpr))
1309 : {
1310 110 : CoalesceExpr *cexpr = (CoalesceExpr *) newnode;
1311 : ListCell *lc;
1312 :
1313 : Assert(cexpr->args != NIL);
1314 330 : foreach(lc, cexpr->args)
1315 : {
1316 220 : if (!is_standard_join_alias_expression(lfirst(lc), oldvar))
1317 0 : return false;
1318 : }
1319 110 : return true;
1320 : }
1321 : else
1322 10 : return false;
1323 : }
1324 :
1325 : /*
1326 : * Insert nullingrels into an expression accepted by
1327 : * is_standard_join_alias_expression.
1328 : */
1329 : static void
1330 362 : adjust_standard_join_alias_expression(Node *newnode, Var *oldvar)
1331 : {
1332 362 : if (IsA(newnode, Var) &&
1333 226 : ((Var *) newnode)->varlevelsup == oldvar->varlevelsup)
1334 226 : {
1335 226 : Var *newvar = (Var *) newnode;
1336 :
1337 226 : newvar->varnullingrels = bms_add_members(newvar->varnullingrels,
1338 226 : oldvar->varnullingrels);
1339 : }
1340 136 : else if (IsA(newnode, PlaceHolderVar) &&
1341 0 : ((PlaceHolderVar *) newnode)->phlevelsup == oldvar->varlevelsup)
1342 0 : {
1343 0 : PlaceHolderVar *newphv = (PlaceHolderVar *) newnode;
1344 :
1345 0 : newphv->phnullingrels = bms_add_members(newphv->phnullingrels,
1346 0 : oldvar->varnullingrels);
1347 : }
1348 136 : else if (IsA(newnode, FuncExpr))
1349 : {
1350 13 : FuncExpr *fexpr = (FuncExpr *) newnode;
1351 :
1352 13 : adjust_standard_join_alias_expression(linitial(fexpr->args), oldvar);
1353 : }
1354 123 : else if (IsA(newnode, RelabelType))
1355 : {
1356 13 : RelabelType *relabel = (RelabelType *) newnode;
1357 :
1358 13 : adjust_standard_join_alias_expression((Node *) relabel->arg, oldvar);
1359 : }
1360 110 : else if (IsA(newnode, CoerceViaIO))
1361 : {
1362 0 : CoerceViaIO *iocoerce = (CoerceViaIO *) newnode;
1363 :
1364 0 : adjust_standard_join_alias_expression((Node *) iocoerce->arg, oldvar);
1365 : }
1366 110 : else if (IsA(newnode, ArrayCoerceExpr))
1367 : {
1368 0 : ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) newnode;
1369 :
1370 0 : adjust_standard_join_alias_expression((Node *) acoerce->arg, oldvar);
1371 : }
1372 110 : else if (IsA(newnode, CoalesceExpr))
1373 : {
1374 110 : CoalesceExpr *cexpr = (CoalesceExpr *) newnode;
1375 : ListCell *lc;
1376 :
1377 : Assert(cexpr->args != NIL);
1378 330 : foreach(lc, cexpr->args)
1379 : {
1380 220 : adjust_standard_join_alias_expression(lfirst(lc), oldvar);
1381 : }
1382 : }
1383 : else
1384 : Assert(false);
1385 362 : }
1386 :
1387 : /*
1388 : * alias_relid_set: in a set of RT indexes, replace joins by their
1389 : * underlying base+OJ relids
1390 : */
1391 : static Relids
1392 1730 : alias_relid_set(Query *query, Relids relids)
1393 : {
1394 1730 : Relids result = NULL;
1395 : int rtindex;
1396 :
1397 1730 : rtindex = -1;
1398 4280 : while ((rtindex = bms_next_member(relids, rtindex)) >= 0)
1399 : {
1400 2550 : RangeTblEntry *rte = rt_fetch(rtindex, query->rtable);
1401 :
1402 2550 : if (rte->rtekind == RTE_JOIN)
1403 287 : result = bms_join(result, get_relids_for_join(query, rtindex));
1404 : else
1405 2263 : result = bms_add_member(result, rtindex);
1406 : }
1407 1730 : return result;
1408 : }
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