Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * rewriteHandler.c
4 : * Primary module of query rewriter.
5 : *
6 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : * IDENTIFICATION
10 : * src/backend/rewrite/rewriteHandler.c
11 : *
12 : * NOTES
13 : * Some of the terms used in this file are of historic nature: "retrieve"
14 : * was the PostQUEL keyword for what today is SELECT. "RIR" stands for
15 : * "Retrieve-Instead-Retrieve", that is an ON SELECT DO INSTEAD SELECT rule
16 : * (which has to be unconditional and where only one rule can exist on each
17 : * relation).
18 : *
19 : *-------------------------------------------------------------------------
20 : */
21 : #include "postgres.h"
22 :
23 : #include "access/relation.h"
24 : #include "access/sysattr.h"
25 : #include "access/table.h"
26 : #include "catalog/dependency.h"
27 : #include "commands/trigger.h"
28 : #include "executor/executor.h"
29 : #include "foreign/fdwapi.h"
30 : #include "miscadmin.h"
31 : #include "nodes/makefuncs.h"
32 : #include "nodes/nodeFuncs.h"
33 : #include "optimizer/optimizer.h"
34 : #include "parser/analyze.h"
35 : #include "parser/parse_coerce.h"
36 : #include "parser/parse_relation.h"
37 : #include "parser/parsetree.h"
38 : #include "rewrite/rewriteDefine.h"
39 : #include "rewrite/rewriteGraphTable.h"
40 : #include "rewrite/rewriteHandler.h"
41 : #include "rewrite/rewriteManip.h"
42 : #include "rewrite/rewriteSearchCycle.h"
43 : #include "rewrite/rowsecurity.h"
44 : #include "tcop/tcopprot.h"
45 : #include "utils/builtins.h"
46 : #include "utils/lsyscache.h"
47 : #include "utils/rel.h"
48 :
49 :
50 : /* We use a list of these to detect recursion in RewriteQuery */
51 : typedef struct rewrite_event
52 : {
53 : Oid relation; /* OID of relation having rules */
54 : CmdType event; /* type of rule being fired */
55 : } rewrite_event;
56 :
57 : typedef struct acquireLocksOnSubLinks_context
58 : {
59 : bool for_execute; /* AcquireRewriteLocks' forExecute param */
60 : } acquireLocksOnSubLinks_context;
61 :
62 : typedef struct fireRIRonSubLink_context
63 : {
64 : List *activeRIRs;
65 : bool hasRowSecurity;
66 : } fireRIRonSubLink_context;
67 :
68 : static bool acquireLocksOnSubLinks(Node *node,
69 : acquireLocksOnSubLinks_context *context);
70 : static Query *rewriteRuleAction(Query *parsetree,
71 : Query *rule_action,
72 : Node *rule_qual,
73 : int rt_index,
74 : CmdType event,
75 : bool *returning_flag);
76 : static List *adjustJoinTreeList(Query *parsetree, bool removert, int rt_index);
77 : static List *rewriteTargetListIU(List *targetList,
78 : CmdType commandType,
79 : OverridingKind override,
80 : Relation target_relation,
81 : RangeTblEntry *values_rte,
82 : int values_rte_index,
83 : Bitmapset **unused_values_attrnos);
84 : static TargetEntry *process_matched_tle(TargetEntry *src_tle,
85 : TargetEntry *prior_tle,
86 : const char *attrName);
87 : static Node *get_assignment_input(Node *node);
88 : static Bitmapset *findDefaultOnlyColumns(RangeTblEntry *rte);
89 : static bool rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
90 : Relation target_relation,
91 : Bitmapset *unused_cols);
92 : static void rewriteValuesRTEToNulls(Query *parsetree, RangeTblEntry *rte);
93 : static void markQueryForLocking(Query *qry, Node *jtnode,
94 : LockClauseStrength strength, LockWaitPolicy waitPolicy,
95 : bool pushedDown);
96 : static List *matchLocks(CmdType event, Relation relation,
97 : int varno, Query *parsetree, bool *hasUpdate);
98 : static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
99 : static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
100 : static Node *expand_generated_columns_internal(Node *node, Relation rel, int rt_index,
101 : RangeTblEntry *rte, int result_relation);
102 :
103 :
104 : /*
105 : * AcquireRewriteLocks -
106 : * Acquire suitable locks on all the relations mentioned in the Query.
107 : * These locks will ensure that the relation schemas don't change under us
108 : * while we are rewriting, planning, and executing the query.
109 : *
110 : * Caution: this may modify the querytree, therefore caller should usually
111 : * have done a copyObject() to make a writable copy of the querytree in the
112 : * current memory context.
113 : *
114 : * forExecute indicates that the query is about to be executed. If so,
115 : * we'll acquire the lock modes specified in the RTE rellockmode fields.
116 : * If forExecute is false, AccessShareLock is acquired on all relations.
117 : * This case is suitable for ruleutils.c, for example, where we only need
118 : * schema stability and we don't intend to actually modify any relations.
119 : *
120 : * forUpdatePushedDown indicates that a pushed-down FOR [KEY] UPDATE/SHARE
121 : * applies to the current subquery, requiring all rels to be opened with at
122 : * least RowShareLock. This should always be false at the top of the
123 : * recursion. When it is true, we adjust RTE rellockmode fields to reflect
124 : * the higher lock level. This flag is ignored if forExecute is false.
125 : *
126 : * A secondary purpose of this routine is to fix up JOIN RTE references to
127 : * dropped columns (see details below). Such RTEs are modified in-place.
128 : *
129 : * This processing can, and for efficiency's sake should, be skipped when the
130 : * querytree has just been built by the parser: parse analysis already got
131 : * all the same locks we'd get here, and the parser will have omitted dropped
132 : * columns from JOINs to begin with. But we must do this whenever we are
133 : * dealing with a querytree produced earlier than the current command.
134 : *
135 : * About JOINs and dropped columns: although the parser never includes an
136 : * already-dropped column in a JOIN RTE's alias var list, it is possible for
137 : * such a list in a stored rule to include references to dropped columns.
138 : * (If the column is not explicitly referenced anywhere else in the query,
139 : * the dependency mechanism won't consider it used by the rule and so won't
140 : * prevent the column drop.) To support get_rte_attribute_is_dropped(), we
141 : * replace join alias vars that reference dropped columns with null pointers.
142 : *
143 : * (In PostgreSQL 8.0, we did not do this processing but instead had
144 : * get_rte_attribute_is_dropped() recurse to detect dropped columns in joins.
145 : * That approach had horrible performance unfortunately; in particular
146 : * construction of a nested join was O(N^2) in the nesting depth.)
147 : */
148 : void
149 29020 : AcquireRewriteLocks(Query *parsetree,
150 : bool forExecute,
151 : bool forUpdatePushedDown)
152 : {
153 : ListCell *l;
154 : int rt_index;
155 : acquireLocksOnSubLinks_context context;
156 :
157 29020 : context.for_execute = forExecute;
158 :
159 : /*
160 : * First, process RTEs of the current query level.
161 : */
162 29020 : rt_index = 0;
163 97863 : foreach(l, parsetree->rtable)
164 : {
165 68843 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
166 : Relation rel;
167 : LOCKMODE lockmode;
168 : List *newaliasvars;
169 : Index curinputvarno;
170 : RangeTblEntry *curinputrte;
171 : ListCell *ll;
172 :
173 68843 : ++rt_index;
174 68843 : switch (rte->rtekind)
175 : {
176 39928 : case RTE_RELATION:
177 : case RTE_GRAPH_TABLE:
178 :
179 : /*
180 : * Grab the appropriate lock type for the relation, and do not
181 : * release it until end of transaction. This protects the
182 : * rewriter, planner, and executor against schema changes
183 : * mid-query.
184 : *
185 : * If forExecute is false, ignore rellockmode and just use
186 : * AccessShareLock.
187 : */
188 39928 : if (!forExecute)
189 4696 : lockmode = AccessShareLock;
190 35232 : else if (forUpdatePushedDown)
191 : {
192 : /* Upgrade RTE's lock mode to reflect pushed-down lock */
193 64 : if (rte->rellockmode == AccessShareLock)
194 64 : rte->rellockmode = RowShareLock;
195 64 : lockmode = rte->rellockmode;
196 : }
197 : else
198 35168 : lockmode = rte->rellockmode;
199 :
200 39928 : rel = relation_open(rte->relid, lockmode);
201 :
202 : /*
203 : * While we have the relation open, update the RTE's relkind,
204 : * just in case it changed since this rule was made.
205 : */
206 39928 : rte->relkind = rel->rd_rel->relkind;
207 :
208 39928 : relation_close(rel, NoLock);
209 39928 : break;
210 :
211 16296 : case RTE_JOIN:
212 :
213 : /*
214 : * Scan the join's alias var list to see if any columns have
215 : * been dropped, and if so replace those Vars with null
216 : * pointers.
217 : *
218 : * Since a join has only two inputs, we can expect to see
219 : * multiple references to the same input RTE; optimize away
220 : * multiple fetches.
221 : */
222 16296 : newaliasvars = NIL;
223 16296 : curinputvarno = 0;
224 16296 : curinputrte = NULL;
225 636517 : foreach(ll, rte->joinaliasvars)
226 : {
227 620221 : Var *aliasitem = (Var *) lfirst(ll);
228 620221 : Var *aliasvar = aliasitem;
229 :
230 : /* Look through any implicit coercion */
231 620221 : aliasvar = (Var *) strip_implicit_coercions((Node *) aliasvar);
232 :
233 : /*
234 : * If the list item isn't a simple Var, then it must
235 : * represent a merged column, ie a USING column, and so it
236 : * couldn't possibly be dropped, since it's referenced in
237 : * the join clause. (Conceivably it could also be a null
238 : * pointer already? But that's OK too.)
239 : */
240 620221 : if (aliasvar && IsA(aliasvar, Var))
241 : {
242 : /*
243 : * The elements of an alias list have to refer to
244 : * earlier RTEs of the same rtable, because that's the
245 : * order the planner builds things in. So we already
246 : * processed the referenced RTE, and so it's safe to
247 : * use get_rte_attribute_is_dropped on it. (This might
248 : * not hold after rewriting or planning, but it's OK
249 : * to assume here.)
250 : */
251 : Assert(aliasvar->varlevelsup == 0);
252 620105 : if (aliasvar->varno != curinputvarno)
253 : {
254 42880 : curinputvarno = aliasvar->varno;
255 42880 : if (curinputvarno >= rt_index)
256 0 : elog(ERROR, "unexpected varno %d in JOIN RTE %d",
257 : curinputvarno, rt_index);
258 42880 : curinputrte = rt_fetch(curinputvarno,
259 : parsetree->rtable);
260 : }
261 620105 : if (get_rte_attribute_is_dropped(curinputrte,
262 620105 : aliasvar->varattno))
263 : {
264 : /* Replace the join alias item with a NULL */
265 4 : aliasitem = NULL;
266 : }
267 : }
268 620221 : newaliasvars = lappend(newaliasvars, aliasitem);
269 : }
270 16296 : rte->joinaliasvars = newaliasvars;
271 16296 : break;
272 :
273 6053 : case RTE_SUBQUERY:
274 :
275 : /*
276 : * The subquery RTE itself is all right, but we have to
277 : * recurse to process the represented subquery.
278 : */
279 6053 : AcquireRewriteLocks(rte->subquery,
280 : forExecute,
281 12106 : (forUpdatePushedDown ||
282 12106 : get_parse_rowmark(parsetree, rt_index) != NULL));
283 6053 : break;
284 :
285 6566 : default:
286 : /* ignore other types of RTEs */
287 6566 : break;
288 : }
289 : }
290 :
291 : /* Recurse into subqueries in WITH */
292 29221 : foreach(l, parsetree->cteList)
293 : {
294 201 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
295 :
296 201 : AcquireRewriteLocks((Query *) cte->ctequery, forExecute, false);
297 : }
298 :
299 : /*
300 : * Recurse into sublink subqueries, too. But we already did the ones in
301 : * the rtable and cteList.
302 : */
303 29020 : if (parsetree->hasSubLinks)
304 1390 : query_tree_walker(parsetree, acquireLocksOnSubLinks, &context,
305 : QTW_IGNORE_RC_SUBQUERIES);
306 29020 : }
307 :
308 : /*
309 : * Walker to find sublink subqueries for AcquireRewriteLocks
310 : */
311 : static bool
312 129442 : acquireLocksOnSubLinks(Node *node, acquireLocksOnSubLinks_context *context)
313 : {
314 129442 : if (node == NULL)
315 25401 : return false;
316 104041 : if (IsA(node, SubLink))
317 : {
318 2942 : SubLink *sub = (SubLink *) node;
319 :
320 : /* Do what we came for */
321 2942 : AcquireRewriteLocks((Query *) sub->subselect,
322 2942 : context->for_execute,
323 : false);
324 : /* Fall through to process lefthand args of SubLink */
325 : }
326 :
327 : /*
328 : * Do NOT recurse into Query nodes, because AcquireRewriteLocks already
329 : * processed subselects of subselects for us.
330 : */
331 104041 : return expression_tree_walker(node, acquireLocksOnSubLinks, context);
332 : }
333 :
334 :
335 : /*
336 : * rewriteRuleAction -
337 : * Rewrite the rule action with appropriate qualifiers (taken from
338 : * the triggering query).
339 : *
340 : * Input arguments:
341 : * parsetree - original query
342 : * rule_action - one action (query) of a rule
343 : * rule_qual - WHERE condition of rule, or NULL if unconditional
344 : * rt_index - RT index of result relation in original query
345 : * event - type of rule event
346 : * Output arguments:
347 : * *returning_flag - set true if we rewrite RETURNING clause in rule_action
348 : * (must be initialized to false)
349 : * Return value:
350 : * rewritten form of rule_action
351 : */
352 : static Query *
353 944 : rewriteRuleAction(Query *parsetree,
354 : Query *rule_action,
355 : Node *rule_qual,
356 : int rt_index,
357 : CmdType event,
358 : bool *returning_flag)
359 : {
360 : int current_varno,
361 : new_varno;
362 : int rt_length;
363 : Query *sub_action;
364 : Query **sub_action_ptr;
365 : acquireLocksOnSubLinks_context context;
366 : ListCell *lc;
367 :
368 944 : context.for_execute = true;
369 :
370 : /*
371 : * Make modifiable copies of rule action and qual (what we're passed are
372 : * the stored versions in the relcache; don't touch 'em!).
373 : */
374 944 : rule_action = copyObject(rule_action);
375 944 : rule_qual = copyObject(rule_qual);
376 :
377 : /*
378 : * Acquire necessary locks and fix any deleted JOIN RTE entries.
379 : */
380 944 : AcquireRewriteLocks(rule_action, true, false);
381 944 : (void) acquireLocksOnSubLinks(rule_qual, &context);
382 :
383 944 : current_varno = rt_index;
384 944 : rt_length = list_length(parsetree->rtable);
385 944 : new_varno = PRS2_NEW_VARNO + rt_length;
386 :
387 : /*
388 : * Adjust rule action and qual to offset its varnos, so that we can merge
389 : * its rtable with the main parsetree's rtable.
390 : *
391 : * If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries
392 : * will be in the SELECT part, and we have to modify that rather than the
393 : * top-level INSERT (kluge!).
394 : */
395 944 : sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr);
396 :
397 944 : OffsetVarNodes((Node *) sub_action, rt_length, 0);
398 944 : OffsetVarNodes(rule_qual, rt_length, 0);
399 : /* but references to OLD should point at original rt_index */
400 944 : ChangeVarNodes((Node *) sub_action,
401 : PRS2_OLD_VARNO + rt_length, rt_index, 0);
402 944 : ChangeVarNodes(rule_qual,
403 : PRS2_OLD_VARNO + rt_length, rt_index, 0);
404 :
405 : /*
406 : * Mark any subquery RTEs in the rule action as LATERAL if they contain
407 : * Vars referring to the current query level (references to NEW/OLD).
408 : * Those really are lateral references, but we've historically not
409 : * required users to mark such subqueries with LATERAL explicitly. But
410 : * the planner will complain if such Vars exist in a non-LATERAL subquery,
411 : * so we have to fix things up here.
412 : */
413 3756 : foreach(lc, sub_action->rtable)
414 : {
415 2812 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
416 :
417 2820 : if (rte->rtekind == RTE_SUBQUERY && !rte->lateral &&
418 8 : contain_vars_of_level((Node *) rte->subquery, 1))
419 8 : rte->lateral = true;
420 : }
421 :
422 : /*
423 : * Generate expanded rtable consisting of main parsetree's rtable plus
424 : * rule action's rtable; this becomes the complete rtable for the rule
425 : * action. Some of the entries may be unused after we finish rewriting,
426 : * but we leave them all in place to avoid having to adjust the query's
427 : * varnos. RT entries that are not referenced in the completed jointree
428 : * will be ignored by the planner, so they do not affect query semantics.
429 : *
430 : * Also merge RTEPermissionInfo lists to ensure that all permissions are
431 : * checked correctly.
432 : *
433 : * If the rule is INSTEAD, then the original query won't be executed at
434 : * all, and so its rteperminfos must be preserved so that the executor
435 : * will do the correct permissions checks on the relations referenced in
436 : * it. This allows us to check that the caller has, say, insert-permission
437 : * on a view, when the view is not semantically referenced at all in the
438 : * resulting query.
439 : *
440 : * When a rule is not INSTEAD, the permissions checks done using the
441 : * copied entries will be redundant with those done during execution of
442 : * the original query, but we don't bother to treat that case differently.
443 : *
444 : * NOTE: because planner will destructively alter rtable and rteperminfos,
445 : * we must ensure that rule action's lists are separate and shares no
446 : * substructure with the main query's lists. Hence do a deep copy here
447 : * for both.
448 : */
449 : {
450 944 : List *rtable_tail = sub_action->rtable;
451 944 : List *perminfos_tail = sub_action->rteperminfos;
452 :
453 : /*
454 : * RewriteQuery relies on the fact that RT entries from the original
455 : * query appear at the start of the expanded rtable, so we put the
456 : * action's original table at the end of the list.
457 : */
458 944 : sub_action->rtable = copyObject(parsetree->rtable);
459 944 : sub_action->rteperminfos = copyObject(parsetree->rteperminfos);
460 944 : CombineRangeTables(&sub_action->rtable, &sub_action->rteperminfos,
461 : rtable_tail, perminfos_tail);
462 : }
463 :
464 : /*
465 : * There could have been some SubLinks in parsetree's rtable, in which
466 : * case we'd better mark the sub_action correctly.
467 : */
468 944 : if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
469 : {
470 44 : foreach(lc, parsetree->rtable)
471 : {
472 32 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
473 :
474 32 : switch (rte->rtekind)
475 : {
476 28 : case RTE_RELATION:
477 28 : sub_action->hasSubLinks =
478 28 : checkExprHasSubLink((Node *) rte->tablesample);
479 28 : break;
480 0 : case RTE_FUNCTION:
481 0 : sub_action->hasSubLinks =
482 0 : checkExprHasSubLink((Node *) rte->functions);
483 0 : break;
484 0 : case RTE_TABLEFUNC:
485 0 : sub_action->hasSubLinks =
486 0 : checkExprHasSubLink((Node *) rte->tablefunc);
487 0 : break;
488 0 : case RTE_VALUES:
489 0 : sub_action->hasSubLinks =
490 0 : checkExprHasSubLink((Node *) rte->values_lists);
491 0 : break;
492 4 : default:
493 : /* other RTE types don't contain bare expressions */
494 4 : break;
495 : }
496 32 : sub_action->hasSubLinks |=
497 32 : checkExprHasSubLink((Node *) rte->securityQuals);
498 32 : if (sub_action->hasSubLinks)
499 4 : break; /* no need to keep scanning rtable */
500 : }
501 : }
502 :
503 : /*
504 : * Also, we might have absorbed some RTEs with RLS conditions into the
505 : * sub_action. If so, mark it as hasRowSecurity, whether or not those
506 : * RTEs will be referenced after we finish rewriting. (Note: currently
507 : * this is a no-op because RLS conditions aren't added till later, but it
508 : * seems like good future-proofing to do this anyway.)
509 : */
510 944 : sub_action->hasRowSecurity |= parsetree->hasRowSecurity;
511 :
512 : /*
513 : * Each rule action's jointree should be the main parsetree's jointree
514 : * plus that rule's jointree, but usually *without* the original rtindex
515 : * that we're replacing (if present, which it won't be for INSERT). Note
516 : * that if the rule action refers to OLD, its jointree will add a
517 : * reference to rt_index. If the rule action doesn't refer to OLD, but
518 : * either the rule_qual or the user query quals do, then we need to keep
519 : * the original rtindex in the jointree to provide data for the quals. We
520 : * don't want the original rtindex to be joined twice, however, so avoid
521 : * keeping it if the rule action mentions it.
522 : *
523 : * As above, the action's jointree must not share substructure with the
524 : * main parsetree's.
525 : */
526 944 : if (sub_action->commandType != CMD_UTILITY)
527 : {
528 : bool keeporig;
529 : List *newjointree;
530 :
531 : Assert(sub_action->jointree != NULL);
532 924 : keeporig = (!rangeTableEntry_used((Node *) sub_action->jointree,
533 2172 : rt_index, 0)) &&
534 1248 : (rangeTableEntry_used(rule_qual, rt_index, 0) ||
535 624 : rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0));
536 924 : newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index);
537 924 : if (newjointree != NIL)
538 : {
539 : /*
540 : * If sub_action is a setop, manipulating its jointree will do no
541 : * good at all, because the jointree is dummy. (Perhaps someday
542 : * we could push the joining and quals down to the member
543 : * statements of the setop?)
544 : */
545 184 : if (sub_action->setOperations != NULL)
546 0 : ereport(ERROR,
547 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
548 : errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
549 :
550 368 : sub_action->jointree->fromlist =
551 184 : list_concat(newjointree, sub_action->jointree->fromlist);
552 :
553 : /*
554 : * There could have been some SubLinks in newjointree, in which
555 : * case we'd better mark the sub_action correctly.
556 : */
557 184 : if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
558 4 : sub_action->hasSubLinks =
559 4 : checkExprHasSubLink((Node *) newjointree);
560 : }
561 : }
562 :
563 : /*
564 : * If the original query has any CTEs, copy them into the rule action. But
565 : * we don't need them for a utility action.
566 : */
567 944 : if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY)
568 : {
569 : /*
570 : * Annoying implementation restriction: because CTEs are identified by
571 : * name within a cteList, we can't merge a CTE from the original query
572 : * if it has the same name as any CTE in the rule action.
573 : *
574 : * This could possibly be fixed by using some sort of internally
575 : * generated ID, instead of names, to link CTE RTEs to their CTEs.
576 : * However, decompiling the results would be quite confusing; note the
577 : * merge of hasRecursive flags below, which could change the apparent
578 : * semantics of such redundantly-named CTEs.
579 : */
580 48 : foreach(lc, parsetree->cteList)
581 : {
582 24 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
583 : ListCell *lc2;
584 :
585 28 : foreach(lc2, sub_action->cteList)
586 : {
587 4 : CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(lc2);
588 :
589 4 : if (strcmp(cte->ctename, cte2->ctename) == 0)
590 0 : ereport(ERROR,
591 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
592 : errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten",
593 : cte->ctename)));
594 : }
595 : }
596 :
597 : /*
598 : * OK, it's safe to combine the CTE lists. Beware that RewriteQuery
599 : * knows we concatenate the lists in this order.
600 : */
601 24 : sub_action->cteList = list_concat(sub_action->cteList,
602 24 : copyObject(parsetree->cteList));
603 : /* ... and don't forget about the associated flags */
604 24 : sub_action->hasRecursive |= parsetree->hasRecursive;
605 24 : sub_action->hasModifyingCTE |= parsetree->hasModifyingCTE;
606 :
607 : /*
608 : * If rule_action is different from sub_action (i.e., the rule action
609 : * is an INSERT...SELECT), then we might have just added some
610 : * data-modifying CTEs that are not at the top query level. This is
611 : * disallowed by the parser and we mustn't generate such trees here
612 : * either, so throw an error.
613 : *
614 : * Conceivably such cases could be supported by attaching the original
615 : * query's CTEs to rule_action not sub_action. But to do that, we'd
616 : * have to increment ctelevelsup in RTEs and SubLinks copied from the
617 : * original query. For now, it doesn't seem worth the trouble.
618 : */
619 24 : if (sub_action->hasModifyingCTE && rule_action != sub_action)
620 4 : ereport(ERROR,
621 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
622 : errmsg("INSERT ... SELECT rule actions are not supported for queries having data-modifying statements in WITH")));
623 : }
624 :
625 : /*
626 : * Event Qualification forces copying of parsetree and splitting into two
627 : * queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual
628 : * onto rule action
629 : */
630 940 : AddQual(sub_action, rule_qual);
631 :
632 940 : AddQual(sub_action, parsetree->jointree->quals);
633 :
634 : /*
635 : * Rewrite new.attribute with right hand side of target-list entry for
636 : * appropriate field name in insert/update.
637 : *
638 : * KLUGE ALERT: since ReplaceVarsFromTargetList returns a mutated copy, we
639 : * can't just apply it to sub_action; we have to remember to update the
640 : * sublink inside rule_action, too.
641 : */
642 940 : if ((event == CMD_INSERT || event == CMD_UPDATE) &&
643 820 : sub_action->commandType != CMD_UTILITY)
644 : {
645 : sub_action = (Query *)
646 1600 : ReplaceVarsFromTargetList((Node *) sub_action,
647 : new_varno,
648 : 0,
649 800 : rt_fetch(new_varno, sub_action->rtable),
650 : parsetree->targetList,
651 : sub_action->resultRelation,
652 : (event == CMD_UPDATE) ?
653 : REPLACEVARS_CHANGE_VARNO :
654 : REPLACEVARS_SUBSTITUTE_NULL,
655 : current_varno,
656 : NULL);
657 800 : if (sub_action_ptr)
658 36 : *sub_action_ptr = sub_action;
659 : else
660 764 : rule_action = sub_action;
661 : }
662 :
663 : /*
664 : * If rule_action is INSERT .. ON CONFLICT DO SELECT, the parser should
665 : * have verified that it has a RETURNING clause, but we must also check
666 : * that the triggering query has a RETURNING clause.
667 : */
668 940 : if (rule_action->onConflict &&
669 52 : rule_action->onConflict->action == ONCONFLICT_SELECT &&
670 20 : (!rule_action->returningList || !parsetree->returningList))
671 4 : ereport(ERROR,
672 : errcode(ERRCODE_SYNTAX_ERROR),
673 : errmsg("ON CONFLICT DO SELECT requires a RETURNING clause"),
674 : errdetail("A rule action is INSERT ... ON CONFLICT DO SELECT, which requires a RETURNING clause."));
675 :
676 : /*
677 : * If rule_action has a RETURNING clause, then either throw it away if the
678 : * triggering query has no RETURNING clause, or rewrite it to emit what
679 : * the triggering query's RETURNING clause asks for. Throw an error if
680 : * more than one rule has a RETURNING clause.
681 : */
682 936 : if (!parsetree->returningList)
683 816 : rule_action->returningList = NIL;
684 120 : else if (rule_action->returningList)
685 : {
686 112 : if (*returning_flag)
687 0 : ereport(ERROR,
688 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
689 : errmsg("cannot have RETURNING lists in multiple rules")));
690 112 : *returning_flag = true;
691 112 : rule_action->returningList = (List *)
692 112 : ReplaceVarsFromTargetList((Node *) parsetree->returningList,
693 : parsetree->resultRelation,
694 : 0,
695 112 : rt_fetch(parsetree->resultRelation,
696 : parsetree->rtable),
697 : rule_action->returningList,
698 : rule_action->resultRelation,
699 : REPLACEVARS_REPORT_ERROR,
700 : 0,
701 : &rule_action->hasSubLinks);
702 :
703 : /* use triggering query's aliases for OLD and NEW in RETURNING list */
704 112 : rule_action->returningOldAlias = parsetree->returningOldAlias;
705 112 : rule_action->returningNewAlias = parsetree->returningNewAlias;
706 :
707 : /*
708 : * There could have been some SubLinks in parsetree's returningList,
709 : * in which case we'd better mark the rule_action correctly.
710 : */
711 112 : if (parsetree->hasSubLinks && !rule_action->hasSubLinks)
712 0 : rule_action->hasSubLinks =
713 0 : checkExprHasSubLink((Node *) rule_action->returningList);
714 : }
715 :
716 936 : return rule_action;
717 : }
718 :
719 : /*
720 : * Copy the query's jointree list, and optionally attempt to remove any
721 : * occurrence of the given rt_index as a top-level join item (we do not look
722 : * for it within join items; this is OK because we are only expecting to find
723 : * it as an UPDATE or DELETE target relation, which will be at the top level
724 : * of the join). Returns modified jointree list --- this is a separate copy
725 : * sharing no nodes with the original.
726 : */
727 : static List *
728 924 : adjustJoinTreeList(Query *parsetree, bool removert, int rt_index)
729 : {
730 924 : List *newjointree = copyObject(parsetree->jointree->fromlist);
731 : ListCell *l;
732 :
733 924 : if (removert)
734 : {
735 1084 : foreach(l, newjointree)
736 : {
737 496 : RangeTblRef *rtr = lfirst(l);
738 :
739 496 : if (IsA(rtr, RangeTblRef) &&
740 496 : rtr->rtindex == rt_index)
741 : {
742 336 : newjointree = foreach_delete_current(newjointree, l);
743 336 : break;
744 : }
745 : }
746 : }
747 924 : return newjointree;
748 : }
749 :
750 :
751 : /*
752 : * rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form
753 : *
754 : * This has the following responsibilities:
755 : *
756 : * 1. For an INSERT, add tlist entries to compute default values for any
757 : * attributes that have defaults and are not assigned to in the given tlist.
758 : * (We do not insert anything for default-less attributes, however. The
759 : * planner will later insert NULLs for them, but there's no reason to slow
760 : * down rewriter processing with extra tlist nodes.) Also, for both INSERT
761 : * and UPDATE, replace explicit DEFAULT specifications with column default
762 : * expressions.
763 : *
764 : * 2. Merge multiple entries for the same target attribute, or declare error
765 : * if we can't. Multiple entries are only allowed for INSERT/UPDATE of
766 : * portions of an array or record field, for example
767 : * UPDATE table SET foo[2] = 42, foo[4] = 43;
768 : * We can merge such operations into a single assignment op. Essentially,
769 : * the expression we want to produce in this case is like
770 : * foo = array_set_element(array_set_element(foo, 2, 42), 4, 43)
771 : *
772 : * 3. Sort the tlist into standard order: non-junk fields in order by resno,
773 : * then junk fields (these in no particular order).
774 : *
775 : * We must do items 1 and 2 before firing rewrite rules, else rewritten
776 : * references to NEW.foo will produce wrong or incomplete results. Item 3
777 : * is not needed for rewriting, but it is helpful for the planner, and we
778 : * can do it essentially for free while handling the other items.
779 : *
780 : * If values_rte is non-NULL (i.e., we are doing a multi-row INSERT using
781 : * values from a VALUES RTE), we populate *unused_values_attrnos with the
782 : * attribute numbers of any unused columns from the VALUES RTE. This can
783 : * happen for identity and generated columns whose targetlist entries are
784 : * replaced with generated expressions (if INSERT ... OVERRIDING USER VALUE is
785 : * used, or all the values to be inserted are DEFAULT). This information is
786 : * required by rewriteValuesRTE() to handle any DEFAULT items in the unused
787 : * columns. The caller must have initialized *unused_values_attrnos to NULL.
788 : */
789 : static List *
790 56619 : rewriteTargetListIU(List *targetList,
791 : CmdType commandType,
792 : OverridingKind override,
793 : Relation target_relation,
794 : RangeTblEntry *values_rte,
795 : int values_rte_index,
796 : Bitmapset **unused_values_attrnos)
797 : {
798 : TargetEntry **new_tles;
799 56619 : List *new_tlist = NIL;
800 56619 : List *junk_tlist = NIL;
801 : Form_pg_attribute att_tup;
802 : int attrno,
803 : next_junk_attrno,
804 : numattrs;
805 : ListCell *temp;
806 56619 : Bitmapset *default_only_cols = NULL;
807 :
808 : /*
809 : * We process the normal (non-junk) attributes by scanning the input tlist
810 : * once and transferring TLEs into an array, then scanning the array to
811 : * build an output tlist. This avoids O(N^2) behavior for large numbers
812 : * of attributes.
813 : *
814 : * Junk attributes are tossed into a separate list during the same tlist
815 : * scan, then appended to the reconstructed tlist.
816 : */
817 56619 : numattrs = RelationGetNumberOfAttributes(target_relation);
818 56619 : new_tles = (TargetEntry **) palloc0(numattrs * sizeof(TargetEntry *));
819 56619 : next_junk_attrno = numattrs + 1;
820 :
821 158033 : foreach(temp, targetList)
822 : {
823 101426 : TargetEntry *old_tle = (TargetEntry *) lfirst(temp);
824 :
825 101426 : if (!old_tle->resjunk)
826 : {
827 : /* Normal attr: stash it into new_tles[] */
828 101339 : attrno = old_tle->resno;
829 101339 : if (attrno < 1 || attrno > numattrs)
830 0 : elog(ERROR, "bogus resno %d in targetlist", attrno);
831 101339 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
832 :
833 : /* We can (and must) ignore deleted attributes */
834 101339 : if (att_tup->attisdropped)
835 0 : continue;
836 :
837 : /* Merge with any prior assignment to same attribute */
838 101327 : new_tles[attrno - 1] =
839 101339 : process_matched_tle(old_tle,
840 101339 : new_tles[attrno - 1],
841 101339 : NameStr(att_tup->attname));
842 : }
843 : else
844 : {
845 : /*
846 : * Copy all resjunk tlist entries to junk_tlist, and assign them
847 : * resnos above the last real resno.
848 : *
849 : * Typical junk entries include ORDER BY or GROUP BY expressions
850 : * (are these actually possible in an INSERT or UPDATE?), system
851 : * attribute references, etc.
852 : */
853 :
854 : /* Get the resno right, but don't copy unnecessarily */
855 87 : if (old_tle->resno != next_junk_attrno)
856 : {
857 0 : old_tle = flatCopyTargetEntry(old_tle);
858 0 : old_tle->resno = next_junk_attrno;
859 : }
860 87 : junk_tlist = lappend(junk_tlist, old_tle);
861 87 : next_junk_attrno++;
862 : }
863 : }
864 :
865 243438 : for (attrno = 1; attrno <= numattrs; attrno++)
866 : {
867 186963 : TargetEntry *new_tle = new_tles[attrno - 1];
868 : bool apply_default;
869 :
870 186963 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
871 :
872 : /* We can (and must) ignore deleted attributes */
873 186963 : if (att_tup->attisdropped)
874 652 : continue;
875 :
876 : /*
877 : * Handle the two cases where we need to insert a default expression:
878 : * it's an INSERT and there's no tlist entry for the column, or the
879 : * tlist entry is a DEFAULT placeholder node.
880 : */
881 287377 : apply_default = ((new_tle == NULL && commandType == CMD_INSERT) ||
882 101066 : (new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault)));
883 :
884 186311 : if (commandType == CMD_INSERT)
885 : {
886 102905 : int values_attrno = 0;
887 :
888 : /* Source attribute number for values that come from a VALUES RTE */
889 102905 : if (values_rte && new_tle && IsA(new_tle->expr, Var))
890 : {
891 6185 : Var *var = (Var *) new_tle->expr;
892 :
893 6185 : if (var->varno == values_rte_index)
894 6185 : values_attrno = var->varattno;
895 : }
896 :
897 : /*
898 : * Can only insert DEFAULT into GENERATED ALWAYS identity columns,
899 : * unless either OVERRIDING USER VALUE or OVERRIDING SYSTEM VALUE
900 : * is specified.
901 : */
902 102905 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS && !apply_default)
903 : {
904 94 : if (override == OVERRIDING_USER_VALUE)
905 28 : apply_default = true;
906 66 : else if (override != OVERRIDING_SYSTEM_VALUE)
907 : {
908 : /*
909 : * If this column's values come from a VALUES RTE, test
910 : * whether it contains only SetToDefault items. Since the
911 : * VALUES list might be quite large, we arrange to only
912 : * scan it once.
913 : */
914 34 : if (values_attrno != 0)
915 : {
916 18 : if (default_only_cols == NULL)
917 18 : default_only_cols = findDefaultOnlyColumns(values_rte);
918 :
919 18 : if (bms_is_member(values_attrno, default_only_cols))
920 6 : apply_default = true;
921 : }
922 :
923 34 : if (!apply_default)
924 28 : ereport(ERROR,
925 : (errcode(ERRCODE_GENERATED_ALWAYS),
926 : errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
927 : NameStr(att_tup->attname)),
928 : errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
929 : NameStr(att_tup->attname)),
930 : errhint("Use OVERRIDING SYSTEM VALUE to override.")));
931 : }
932 : }
933 :
934 : /*
935 : * Although inserting into a GENERATED BY DEFAULT identity column
936 : * is allowed, apply the default if OVERRIDING USER VALUE is
937 : * specified.
938 : */
939 102877 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_BY_DEFAULT &&
940 : override == OVERRIDING_USER_VALUE)
941 12 : apply_default = true;
942 :
943 : /*
944 : * Can only insert DEFAULT into generated columns. (The
945 : * OVERRIDING clause does not apply to generated columns, so we
946 : * don't consider it here.)
947 : */
948 102877 : if (att_tup->attgenerated && !apply_default)
949 : {
950 : /*
951 : * If this column's values come from a VALUES RTE, test
952 : * whether it contains only SetToDefault items, as above.
953 : */
954 113 : if (values_attrno != 0)
955 : {
956 77 : if (default_only_cols == NULL)
957 77 : default_only_cols = findDefaultOnlyColumns(values_rte);
958 :
959 77 : if (bms_is_member(values_attrno, default_only_cols))
960 21 : apply_default = true;
961 : }
962 :
963 113 : if (!apply_default)
964 92 : ereport(ERROR,
965 : (errcode(ERRCODE_GENERATED_ALWAYS),
966 : errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
967 : NameStr(att_tup->attname)),
968 : errdetail("Column \"%s\" is a generated column.",
969 : NameStr(att_tup->attname))));
970 : }
971 :
972 : /*
973 : * For an INSERT from a VALUES RTE, return the attribute numbers
974 : * of any VALUES columns that will no longer be used (due to the
975 : * targetlist entry being replaced by a default expression).
976 : */
977 102785 : if (values_attrno != 0 && apply_default && unused_values_attrnos)
978 43 : *unused_values_attrnos = bms_add_member(*unused_values_attrnos,
979 : values_attrno);
980 : }
981 :
982 : /*
983 : * Updates to identity and generated columns follow the same rules as
984 : * above, except that UPDATE doesn't admit OVERRIDING clauses. Also,
985 : * the source can't be a VALUES RTE, so we needn't consider that.
986 : */
987 186191 : if (commandType == CMD_UPDATE)
988 : {
989 83406 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS &&
990 8 : new_tle && !apply_default)
991 4 : ereport(ERROR,
992 : (errcode(ERRCODE_GENERATED_ALWAYS),
993 : errmsg("column \"%s\" can only be updated to DEFAULT",
994 : NameStr(att_tup->attname)),
995 : errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
996 : NameStr(att_tup->attname))));
997 :
998 83402 : if (att_tup->attgenerated && new_tle && !apply_default)
999 8 : ereport(ERROR,
1000 : (errcode(ERRCODE_GENERATED_ALWAYS),
1001 : errmsg("column \"%s\" can only be updated to DEFAULT",
1002 : NameStr(att_tup->attname)),
1003 : errdetail("Column \"%s\" is a generated column.",
1004 : NameStr(att_tup->attname))));
1005 : }
1006 :
1007 186179 : if (att_tup->attgenerated)
1008 : {
1009 : /*
1010 : * virtual generated column stores a null value; stored generated
1011 : * column will be fixed in executor
1012 : */
1013 1047 : new_tle = NULL;
1014 : }
1015 185132 : else if (apply_default)
1016 : {
1017 : Node *new_expr;
1018 :
1019 15804 : new_expr = build_column_default(target_relation, attrno);
1020 :
1021 : /*
1022 : * If there is no default (ie, default is effectively NULL), we
1023 : * can omit the tlist entry in the INSERT case, since the planner
1024 : * can insert a NULL for itself, and there's no point in spending
1025 : * any more rewriter cycles on the entry. But in the UPDATE case
1026 : * we've got to explicitly set the column to NULL.
1027 : */
1028 15804 : if (!new_expr)
1029 : {
1030 11652 : if (commandType == CMD_INSERT)
1031 11639 : new_tle = NULL;
1032 : else
1033 13 : new_expr = coerce_null_to_domain(att_tup->atttypid,
1034 : att_tup->atttypmod,
1035 : att_tup->attcollation,
1036 13 : att_tup->attlen,
1037 13 : att_tup->attbyval);
1038 : }
1039 :
1040 15804 : if (new_expr)
1041 4165 : new_tle = makeTargetEntry((Expr *) new_expr,
1042 : attrno,
1043 4165 : pstrdup(NameStr(att_tup->attname)),
1044 : false);
1045 : }
1046 :
1047 186179 : if (new_tle)
1048 104555 : new_tlist = lappend(new_tlist, new_tle);
1049 : }
1050 :
1051 56475 : pfree(new_tles);
1052 :
1053 56475 : return list_concat(new_tlist, junk_tlist);
1054 : }
1055 :
1056 :
1057 : /*
1058 : * Convert a matched TLE from the original tlist into a correct new TLE.
1059 : *
1060 : * This routine detects and handles multiple assignments to the same target
1061 : * attribute. (The attribute name is needed only for error messages.)
1062 : */
1063 : static TargetEntry *
1064 101339 : process_matched_tle(TargetEntry *src_tle,
1065 : TargetEntry *prior_tle,
1066 : const char *attrName)
1067 : {
1068 : TargetEntry *result;
1069 101339 : CoerceToDomain *coerce_expr = NULL;
1070 : Node *src_expr;
1071 : Node *prior_expr;
1072 : Node *src_input;
1073 : Node *prior_input;
1074 : Node *priorbottom;
1075 : Node *newexpr;
1076 :
1077 101339 : if (prior_tle == NULL)
1078 : {
1079 : /*
1080 : * Normal case where this is the first assignment to the attribute.
1081 : */
1082 101114 : return src_tle;
1083 : }
1084 :
1085 : /*----------
1086 : * Multiple assignments to same attribute. Allow only if all are
1087 : * FieldStore or SubscriptingRef assignment operations. This is a bit
1088 : * tricky because what we may actually be looking at is a nest of
1089 : * such nodes; consider
1090 : * UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y
1091 : * The two expressions produced by the parser will look like
1092 : * FieldStore(col, fld1, FieldStore(placeholder, subfld1, x))
1093 : * FieldStore(col, fld2, FieldStore(placeholder, subfld2, y))
1094 : * However, we can ignore the substructure and just consider the top
1095 : * FieldStore or SubscriptingRef from each assignment, because it works to
1096 : * combine these as
1097 : * FieldStore(FieldStore(col, fld1,
1098 : * FieldStore(placeholder, subfld1, x)),
1099 : * fld2, FieldStore(placeholder, subfld2, y))
1100 : * Note the leftmost expression goes on the inside so that the
1101 : * assignments appear to occur left-to-right.
1102 : *
1103 : * For FieldStore, instead of nesting we can generate a single
1104 : * FieldStore with multiple target fields. We must nest when
1105 : * SubscriptingRefs are involved though.
1106 : *
1107 : * As a further complication, the destination column might be a domain,
1108 : * resulting in each assignment containing a CoerceToDomain node over a
1109 : * FieldStore or SubscriptingRef. These should have matching target
1110 : * domains, so we strip them and reconstitute a single CoerceToDomain over
1111 : * the combined FieldStore/SubscriptingRef nodes. (Notice that this has
1112 : * the result that the domain's checks are applied only after we do all
1113 : * the field or element updates, not after each one. This is desirable.)
1114 : *----------
1115 : */
1116 225 : src_expr = (Node *) src_tle->expr;
1117 225 : prior_expr = (Node *) prior_tle->expr;
1118 :
1119 225 : if (src_expr && IsA(src_expr, CoerceToDomain) &&
1120 108 : prior_expr && IsA(prior_expr, CoerceToDomain) &&
1121 108 : ((CoerceToDomain *) src_expr)->resulttype ==
1122 108 : ((CoerceToDomain *) prior_expr)->resulttype)
1123 : {
1124 : /* we assume without checking that resulttypmod/resultcollid match */
1125 108 : coerce_expr = (CoerceToDomain *) src_expr;
1126 108 : src_expr = (Node *) ((CoerceToDomain *) src_expr)->arg;
1127 108 : prior_expr = (Node *) ((CoerceToDomain *) prior_expr)->arg;
1128 : }
1129 :
1130 225 : src_input = get_assignment_input(src_expr);
1131 225 : prior_input = get_assignment_input(prior_expr);
1132 225 : if (src_input == NULL ||
1133 213 : prior_input == NULL ||
1134 213 : exprType(src_expr) != exprType(prior_expr))
1135 12 : ereport(ERROR,
1136 : (errcode(ERRCODE_SYNTAX_ERROR),
1137 : errmsg("multiple assignments to same column \"%s\"",
1138 : attrName)));
1139 :
1140 : /*
1141 : * Prior TLE could be a nest of assignments if we do this more than once.
1142 : */
1143 213 : priorbottom = prior_input;
1144 : for (;;)
1145 28 : {
1146 241 : Node *newbottom = get_assignment_input(priorbottom);
1147 :
1148 241 : if (newbottom == NULL)
1149 213 : break; /* found the original Var reference */
1150 28 : priorbottom = newbottom;
1151 : }
1152 213 : if (!equal(priorbottom, src_input))
1153 0 : ereport(ERROR,
1154 : (errcode(ERRCODE_SYNTAX_ERROR),
1155 : errmsg("multiple assignments to same column \"%s\"",
1156 : attrName)));
1157 :
1158 : /*
1159 : * Looks OK to nest 'em.
1160 : */
1161 213 : if (IsA(src_expr, FieldStore))
1162 : {
1163 84 : FieldStore *fstore = makeNode(FieldStore);
1164 :
1165 84 : if (IsA(prior_expr, FieldStore))
1166 : {
1167 : /* combine the two */
1168 84 : memcpy(fstore, prior_expr, sizeof(FieldStore));
1169 84 : fstore->newvals =
1170 84 : list_concat_copy(((FieldStore *) prior_expr)->newvals,
1171 84 : ((FieldStore *) src_expr)->newvals);
1172 84 : fstore->fieldnums =
1173 84 : list_concat_copy(((FieldStore *) prior_expr)->fieldnums,
1174 84 : ((FieldStore *) src_expr)->fieldnums);
1175 : }
1176 : else
1177 : {
1178 : /* general case, just nest 'em */
1179 0 : memcpy(fstore, src_expr, sizeof(FieldStore));
1180 0 : fstore->arg = (Expr *) prior_expr;
1181 : }
1182 84 : newexpr = (Node *) fstore;
1183 : }
1184 129 : else if (IsA(src_expr, SubscriptingRef))
1185 : {
1186 129 : SubscriptingRef *sbsref = makeNode(SubscriptingRef);
1187 :
1188 129 : memcpy(sbsref, src_expr, sizeof(SubscriptingRef));
1189 129 : sbsref->refexpr = (Expr *) prior_expr;
1190 129 : newexpr = (Node *) sbsref;
1191 : }
1192 : else
1193 : {
1194 0 : elog(ERROR, "cannot happen");
1195 : newexpr = NULL;
1196 : }
1197 :
1198 213 : if (coerce_expr)
1199 : {
1200 : /* put back the CoerceToDomain */
1201 108 : CoerceToDomain *newcoerce = makeNode(CoerceToDomain);
1202 :
1203 108 : memcpy(newcoerce, coerce_expr, sizeof(CoerceToDomain));
1204 108 : newcoerce->arg = (Expr *) newexpr;
1205 108 : newexpr = (Node *) newcoerce;
1206 : }
1207 :
1208 213 : result = flatCopyTargetEntry(src_tle);
1209 213 : result->expr = (Expr *) newexpr;
1210 213 : return result;
1211 : }
1212 :
1213 : /*
1214 : * If node is an assignment node, return its input; else return NULL
1215 : */
1216 : static Node *
1217 691 : get_assignment_input(Node *node)
1218 : {
1219 691 : if (node == NULL)
1220 0 : return NULL;
1221 691 : if (IsA(node, FieldStore))
1222 : {
1223 168 : FieldStore *fstore = (FieldStore *) node;
1224 :
1225 168 : return (Node *) fstore->arg;
1226 : }
1227 523 : else if (IsA(node, SubscriptingRef))
1228 : {
1229 286 : SubscriptingRef *sbsref = (SubscriptingRef *) node;
1230 :
1231 286 : if (sbsref->refassgnexpr == NULL)
1232 0 : return NULL;
1233 :
1234 286 : return (Node *) sbsref->refexpr;
1235 : }
1236 :
1237 237 : return NULL;
1238 : }
1239 :
1240 : /*
1241 : * Make an expression tree for the default value for a column.
1242 : *
1243 : * If there is no default, return a NULL instead.
1244 : */
1245 : Node *
1246 98953 : build_column_default(Relation rel, int attrno)
1247 : {
1248 98953 : TupleDesc rd_att = rel->rd_att;
1249 98953 : Form_pg_attribute att_tup = TupleDescAttr(rd_att, attrno - 1);
1250 98953 : Oid atttype = att_tup->atttypid;
1251 98953 : int32 atttypmod = att_tup->atttypmod;
1252 98953 : Node *expr = NULL;
1253 : Oid exprtype;
1254 :
1255 98953 : if (att_tup->attidentity)
1256 : {
1257 335 : NextValueExpr *nve = makeNode(NextValueExpr);
1258 :
1259 335 : nve->seqid = getIdentitySequence(rel, attrno, false);
1260 335 : nve->typeId = att_tup->atttypid;
1261 :
1262 335 : return (Node *) nve;
1263 : }
1264 :
1265 : /*
1266 : * If relation has a default for this column, fetch that expression.
1267 : */
1268 98618 : if (att_tup->atthasdef)
1269 : {
1270 77244 : expr = TupleDescGetDefault(rd_att, attrno);
1271 77244 : if (expr == NULL)
1272 0 : elog(ERROR, "default expression not found for attribute %d of relation \"%s\"",
1273 : attrno, RelationGetRelationName(rel));
1274 : }
1275 :
1276 : /*
1277 : * No per-column default, so look for a default for the type itself. But
1278 : * not for generated columns.
1279 : */
1280 98618 : if (expr == NULL && !att_tup->attgenerated)
1281 21374 : expr = get_typdefault(atttype);
1282 :
1283 98618 : if (expr == NULL)
1284 21209 : return NULL; /* No default anywhere */
1285 :
1286 : /*
1287 : * Make sure the value is coerced to the target column type; this will
1288 : * generally be true already, but there seem to be some corner cases
1289 : * involving domain defaults where it might not be true. This should match
1290 : * the parser's processing of non-defaulted expressions --- see
1291 : * transformAssignedExpr().
1292 : */
1293 77409 : exprtype = exprType(expr);
1294 :
1295 77409 : expr = coerce_to_target_type(NULL, /* no UNKNOWN params here */
1296 : expr, exprtype,
1297 : atttype, atttypmod,
1298 : COERCION_ASSIGNMENT,
1299 : COERCE_IMPLICIT_CAST,
1300 : -1);
1301 77409 : if (expr == NULL)
1302 0 : ereport(ERROR,
1303 : (errcode(ERRCODE_DATATYPE_MISMATCH),
1304 : errmsg("column \"%s\" is of type %s"
1305 : " but default expression is of type %s",
1306 : NameStr(att_tup->attname),
1307 : format_type_be(atttype),
1308 : format_type_be(exprtype)),
1309 : errhint("You will need to rewrite or cast the expression.")));
1310 :
1311 77409 : return expr;
1312 : }
1313 :
1314 :
1315 : /* Does VALUES RTE contain any SetToDefault items? */
1316 : static bool
1317 3223 : searchForDefault(RangeTblEntry *rte)
1318 : {
1319 : ListCell *lc;
1320 :
1321 13933 : foreach(lc, rte->values_lists)
1322 : {
1323 10913 : List *sublist = (List *) lfirst(lc);
1324 : ListCell *lc2;
1325 :
1326 34281 : foreach(lc2, sublist)
1327 : {
1328 23571 : Node *col = (Node *) lfirst(lc2);
1329 :
1330 23571 : if (IsA(col, SetToDefault))
1331 203 : return true;
1332 : }
1333 : }
1334 3020 : return false;
1335 : }
1336 :
1337 :
1338 : /*
1339 : * Search a VALUES RTE for columns that contain only SetToDefault items,
1340 : * returning a Bitmapset containing the attribute numbers of any such columns.
1341 : */
1342 : static Bitmapset *
1343 95 : findDefaultOnlyColumns(RangeTblEntry *rte)
1344 : {
1345 95 : Bitmapset *default_only_cols = NULL;
1346 : ListCell *lc;
1347 :
1348 173 : foreach(lc, rte->values_lists)
1349 : {
1350 146 : List *sublist = (List *) lfirst(lc);
1351 : ListCell *lc2;
1352 : int i;
1353 :
1354 146 : if (default_only_cols == NULL)
1355 : {
1356 : /* Populate the initial result bitmap from the first row */
1357 95 : i = 0;
1358 289 : foreach(lc2, sublist)
1359 : {
1360 194 : Node *col = (Node *) lfirst(lc2);
1361 :
1362 194 : i++;
1363 194 : if (IsA(col, SetToDefault))
1364 48 : default_only_cols = bms_add_member(default_only_cols, i);
1365 : }
1366 : }
1367 : else
1368 : {
1369 : /* Update the result bitmap from this next row */
1370 51 : i = 0;
1371 161 : foreach(lc2, sublist)
1372 : {
1373 110 : Node *col = (Node *) lfirst(lc2);
1374 :
1375 110 : i++;
1376 110 : if (!IsA(col, SetToDefault))
1377 78 : default_only_cols = bms_del_member(default_only_cols, i);
1378 : }
1379 : }
1380 :
1381 : /*
1382 : * If no column in the rows read so far contains only DEFAULT items,
1383 : * we are done.
1384 : */
1385 146 : if (bms_is_empty(default_only_cols))
1386 68 : break;
1387 : }
1388 :
1389 95 : return default_only_cols;
1390 : }
1391 :
1392 :
1393 : /*
1394 : * When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES
1395 : * lists), we have to replace any DEFAULT items in the VALUES lists with
1396 : * the appropriate default expressions. The other aspects of targetlist
1397 : * rewriting need be applied only to the query's targetlist proper.
1398 : *
1399 : * For an auto-updatable view, each DEFAULT item in the VALUES list is
1400 : * replaced with the default from the view, if it has one. Otherwise it is
1401 : * left untouched so that the underlying base relation's default can be
1402 : * applied instead (when we later recurse to here after rewriting the query
1403 : * to refer to the base relation instead of the view).
1404 : *
1405 : * For other types of relation, including rule- and trigger-updatable views,
1406 : * all DEFAULT items are replaced, and if the target relation doesn't have a
1407 : * default, the value is explicitly set to NULL.
1408 : *
1409 : * Also, if a DEFAULT item is found in a column mentioned in unused_cols,
1410 : * it is explicitly set to NULL. This happens for columns in the VALUES RTE
1411 : * whose corresponding targetlist entries have already been replaced with the
1412 : * relation's default expressions, so that any values in those columns of the
1413 : * VALUES RTE are no longer used. This can happen for identity and generated
1414 : * columns (if INSERT ... OVERRIDING USER VALUE is used, or all the values to
1415 : * be inserted are DEFAULT). In principle we could replace all entries in
1416 : * such a column with NULL, whether DEFAULT or not; but it doesn't seem worth
1417 : * the trouble.
1418 : *
1419 : * Note that we may have subscripted or field assignment targetlist entries,
1420 : * as well as more complex expressions from already-replaced DEFAULT items if
1421 : * we have recursed to here for an auto-updatable view. However, it ought to
1422 : * be impossible for such entries to have DEFAULTs assigned to them, except
1423 : * for unused columns, as described above --- we should only have to replace
1424 : * DEFAULT items for targetlist entries that contain simple Vars referencing
1425 : * the VALUES RTE, or which are no longer referred to by the targetlist.
1426 : *
1427 : * Returns true if all DEFAULT items were replaced, and false if some were
1428 : * left untouched.
1429 : */
1430 : static bool
1431 3223 : rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
1432 : Relation target_relation,
1433 : Bitmapset *unused_cols)
1434 : {
1435 : List *newValues;
1436 : ListCell *lc;
1437 : bool isAutoUpdatableView;
1438 : bool allReplaced;
1439 : int numattrs;
1440 : int *attrnos;
1441 :
1442 : /* Steps below are not sensible for non-INSERT queries */
1443 : Assert(parsetree->commandType == CMD_INSERT);
1444 : Assert(rte->rtekind == RTE_VALUES);
1445 :
1446 : /*
1447 : * Rebuilding all the lists is a pretty expensive proposition in a big
1448 : * VALUES list, and it's a waste of time if there aren't any DEFAULT
1449 : * placeholders. So first scan to see if there are any.
1450 : */
1451 3223 : if (!searchForDefault(rte))
1452 3020 : return true; /* nothing to do */
1453 :
1454 : /*
1455 : * Scan the targetlist for entries referring to the VALUES RTE, and note
1456 : * the target attributes. As noted above, we should only need to do this
1457 : * for targetlist entries containing simple Vars --- nothing else in the
1458 : * VALUES RTE should contain DEFAULT items (except possibly for unused
1459 : * columns), and we complain if such a thing does occur.
1460 : */
1461 203 : numattrs = list_length(linitial(rte->values_lists));
1462 203 : attrnos = (int *) palloc0(numattrs * sizeof(int));
1463 :
1464 820 : foreach(lc, parsetree->targetList)
1465 : {
1466 617 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
1467 :
1468 617 : if (IsA(tle->expr, Var))
1469 : {
1470 527 : Var *var = (Var *) tle->expr;
1471 :
1472 527 : if (var->varno == rti)
1473 : {
1474 527 : int attrno = var->varattno;
1475 :
1476 : Assert(attrno >= 1 && attrno <= numattrs);
1477 527 : attrnos[attrno - 1] = tle->resno;
1478 : }
1479 : }
1480 : }
1481 :
1482 : /*
1483 : * Check if the target relation is an auto-updatable view, in which case
1484 : * unresolved defaults will be left untouched rather than being set to
1485 : * NULL.
1486 : */
1487 203 : isAutoUpdatableView = false;
1488 203 : if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
1489 76 : !view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
1490 : {
1491 : List *locks;
1492 : bool hasUpdate;
1493 : bool found;
1494 : ListCell *l;
1495 :
1496 : /* Look for an unconditional DO INSTEAD rule */
1497 68 : locks = matchLocks(CMD_INSERT, target_relation,
1498 : parsetree->resultRelation, parsetree, &hasUpdate);
1499 :
1500 68 : found = false;
1501 84 : foreach(l, locks)
1502 : {
1503 24 : RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
1504 :
1505 24 : if (rule_lock->isInstead &&
1506 8 : rule_lock->qual == NULL)
1507 : {
1508 8 : found = true;
1509 8 : break;
1510 : }
1511 : }
1512 :
1513 : /*
1514 : * If we didn't find an unconditional DO INSTEAD rule, assume that the
1515 : * view is auto-updatable. If it isn't, rewriteTargetView() will
1516 : * throw an error.
1517 : */
1518 68 : if (!found)
1519 60 : isAutoUpdatableView = true;
1520 : }
1521 :
1522 203 : newValues = NIL;
1523 203 : allReplaced = true;
1524 621 : foreach(lc, rte->values_lists)
1525 : {
1526 418 : List *sublist = (List *) lfirst(lc);
1527 418 : List *newList = NIL;
1528 : ListCell *lc2;
1529 : int i;
1530 :
1531 : Assert(list_length(sublist) == numattrs);
1532 :
1533 418 : i = 0;
1534 1662 : foreach(lc2, sublist)
1535 : {
1536 1244 : Node *col = (Node *) lfirst(lc2);
1537 1244 : int attrno = attrnos[i++];
1538 :
1539 1244 : if (IsA(col, SetToDefault))
1540 : {
1541 : Form_pg_attribute att_tup;
1542 : Node *new_expr;
1543 :
1544 : /*
1545 : * If this column isn't used, just replace the DEFAULT with
1546 : * NULL (attrno will be 0 in this case because the targetlist
1547 : * entry will have been replaced by the default expression).
1548 : */
1549 580 : if (bms_is_member(i, unused_cols))
1550 74 : {
1551 74 : SetToDefault *def = (SetToDefault *) col;
1552 :
1553 74 : newList = lappend(newList,
1554 74 : makeNullConst(def->typeId,
1555 : def->typeMod,
1556 : def->collation));
1557 74 : continue;
1558 : }
1559 :
1560 506 : if (attrno == 0)
1561 0 : elog(ERROR, "cannot set value in column %d to DEFAULT", i);
1562 : Assert(attrno > 0 && attrno <= target_relation->rd_att->natts);
1563 506 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
1564 :
1565 506 : if (!att_tup->attisdropped)
1566 506 : new_expr = build_column_default(target_relation, attrno);
1567 : else
1568 0 : new_expr = NULL; /* force a NULL if dropped */
1569 :
1570 : /*
1571 : * If there is no default (ie, default is effectively NULL),
1572 : * we've got to explicitly set the column to NULL, unless the
1573 : * target relation is an auto-updatable view.
1574 : */
1575 506 : if (!new_expr)
1576 : {
1577 238 : if (isAutoUpdatableView)
1578 : {
1579 : /* Leave the value untouched */
1580 100 : newList = lappend(newList, col);
1581 100 : allReplaced = false;
1582 100 : continue;
1583 : }
1584 :
1585 138 : new_expr = coerce_null_to_domain(att_tup->atttypid,
1586 : att_tup->atttypmod,
1587 : att_tup->attcollation,
1588 138 : att_tup->attlen,
1589 138 : att_tup->attbyval);
1590 : }
1591 406 : newList = lappend(newList, new_expr);
1592 : }
1593 : else
1594 664 : newList = lappend(newList, col);
1595 : }
1596 418 : newValues = lappend(newValues, newList);
1597 : }
1598 203 : rte->values_lists = newValues;
1599 :
1600 203 : pfree(attrnos);
1601 :
1602 203 : return allReplaced;
1603 : }
1604 :
1605 : /*
1606 : * Mop up any remaining DEFAULT items in the given VALUES RTE by
1607 : * replacing them with NULL constants.
1608 : *
1609 : * This is used for the product queries generated by DO ALSO rules attached to
1610 : * an auto-updatable view. The action can't depend on the "target relation"
1611 : * since the product query might not have one (it needn't be an INSERT).
1612 : * Essentially, such queries are treated as being attached to a rule-updatable
1613 : * view.
1614 : */
1615 : static void
1616 16 : rewriteValuesRTEToNulls(Query *parsetree, RangeTblEntry *rte)
1617 : {
1618 : List *newValues;
1619 : ListCell *lc;
1620 :
1621 16 : newValues = NIL;
1622 48 : foreach(lc, rte->values_lists)
1623 : {
1624 32 : List *sublist = (List *) lfirst(lc);
1625 32 : List *newList = NIL;
1626 : ListCell *lc2;
1627 :
1628 136 : foreach(lc2, sublist)
1629 : {
1630 104 : Node *col = (Node *) lfirst(lc2);
1631 :
1632 104 : if (IsA(col, SetToDefault))
1633 : {
1634 44 : SetToDefault *def = (SetToDefault *) col;
1635 :
1636 44 : newList = lappend(newList, makeNullConst(def->typeId,
1637 : def->typeMod,
1638 : def->collation));
1639 : }
1640 : else
1641 60 : newList = lappend(newList, col);
1642 : }
1643 32 : newValues = lappend(newValues, newList);
1644 : }
1645 16 : rte->values_lists = newValues;
1646 16 : }
1647 :
1648 :
1649 : /*
1650 : * matchLocks -
1651 : * match a relation's list of locks and returns the matching rules
1652 : */
1653 : static List *
1654 58238 : matchLocks(CmdType event,
1655 : Relation relation,
1656 : int varno,
1657 : Query *parsetree,
1658 : bool *hasUpdate)
1659 : {
1660 58238 : RuleLock *rulelocks = relation->rd_rules;
1661 58238 : List *matching_locks = NIL;
1662 : int nlocks;
1663 : int i;
1664 :
1665 58238 : if (rulelocks == NULL)
1666 54385 : return NIL;
1667 :
1668 3853 : if (parsetree->commandType != CMD_SELECT)
1669 : {
1670 3853 : if (parsetree->resultRelation != varno)
1671 0 : return NIL;
1672 : }
1673 :
1674 3853 : nlocks = rulelocks->numLocks;
1675 :
1676 8786 : for (i = 0; i < nlocks; i++)
1677 : {
1678 4945 : RewriteRule *oneLock = rulelocks->rules[i];
1679 :
1680 4945 : if (oneLock->event == CMD_UPDATE)
1681 440 : *hasUpdate = true;
1682 :
1683 : /*
1684 : * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
1685 : * configured to not fire during the current session's replication
1686 : * role. ON SELECT rules will always be applied in order to keep views
1687 : * working even in LOCAL or REPLICA role.
1688 : */
1689 4945 : if (oneLock->event != CMD_SELECT)
1690 : {
1691 1836 : if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA)
1692 : {
1693 8 : if (oneLock->enabled == RULE_FIRES_ON_ORIGIN ||
1694 4 : oneLock->enabled == RULE_DISABLED)
1695 4 : continue;
1696 : }
1697 : else /* ORIGIN or LOCAL ROLE */
1698 : {
1699 1828 : if (oneLock->enabled == RULE_FIRES_ON_REPLICA ||
1700 1824 : oneLock->enabled == RULE_DISABLED)
1701 20 : continue;
1702 : }
1703 :
1704 : /* Non-SELECT rules are not supported for MERGE */
1705 1812 : if (parsetree->commandType == CMD_MERGE)
1706 12 : ereport(ERROR,
1707 : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1708 : errmsg("cannot execute MERGE on relation \"%s\"",
1709 : RelationGetRelationName(relation)),
1710 : errdetail("MERGE is not supported for relations with rules."));
1711 : }
1712 :
1713 4909 : if (oneLock->event == event)
1714 : {
1715 1072 : if (parsetree->commandType != CMD_SELECT ||
1716 0 : rangeTableEntry_used((Node *) parsetree, varno, 0))
1717 1072 : matching_locks = lappend(matching_locks, oneLock);
1718 : }
1719 : }
1720 :
1721 3841 : return matching_locks;
1722 : }
1723 :
1724 :
1725 : /*
1726 : * ApplyRetrieveRule - expand an ON SELECT rule
1727 : */
1728 : static Query *
1729 10702 : ApplyRetrieveRule(Query *parsetree,
1730 : RewriteRule *rule,
1731 : int rt_index,
1732 : Relation relation,
1733 : List *activeRIRs)
1734 : {
1735 : Query *rule_action;
1736 : RangeTblEntry *rte;
1737 : RowMarkClause *rc;
1738 : int numCols;
1739 :
1740 10702 : if (list_length(rule->actions) != 1)
1741 0 : elog(ERROR, "expected just one rule action");
1742 10702 : if (rule->qual != NULL)
1743 0 : elog(ERROR, "cannot handle qualified ON SELECT rule");
1744 :
1745 : /* Check if the expansion of non-system views are restricted */
1746 10702 : if (unlikely((restrict_nonsystem_relation_kind & RESTRICT_RELKIND_VIEW) != 0 &&
1747 : RelationGetRelid(relation) >= FirstNormalObjectId))
1748 4 : ereport(ERROR,
1749 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1750 : errmsg("access to non-system view \"%s\" is restricted",
1751 : RelationGetRelationName(relation))));
1752 :
1753 10698 : if (rt_index == parsetree->resultRelation)
1754 : {
1755 : /*
1756 : * We have a view as the result relation of the query, and it wasn't
1757 : * rewritten by any rule. This case is supported if there is an
1758 : * INSTEAD OF trigger that will trap attempts to insert/update/delete
1759 : * view rows. The executor will check that; for the moment just plow
1760 : * ahead. We have two cases:
1761 : *
1762 : * For INSERT, we needn't do anything. The unmodified RTE will serve
1763 : * fine as the result relation.
1764 : *
1765 : * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
1766 : * source data for the operation. But we also need an unmodified RTE
1767 : * to serve as the target. So, copy the RTE and add the copy to the
1768 : * rangetable. Note that the copy does not get added to the jointree.
1769 : * Also note that there's a hack in fireRIRrules to avoid calling this
1770 : * function again when it arrives at the copied RTE.
1771 : */
1772 269 : if (parsetree->commandType == CMD_INSERT)
1773 79 : return parsetree;
1774 190 : else if (parsetree->commandType == CMD_UPDATE ||
1775 87 : parsetree->commandType == CMD_DELETE ||
1776 52 : parsetree->commandType == CMD_MERGE)
1777 190 : {
1778 : RangeTblEntry *newrte;
1779 : Var *var;
1780 : TargetEntry *tle;
1781 :
1782 190 : rte = rt_fetch(rt_index, parsetree->rtable);
1783 190 : newrte = copyObject(rte);
1784 190 : parsetree->rtable = lappend(parsetree->rtable, newrte);
1785 190 : parsetree->resultRelation = list_length(parsetree->rtable);
1786 : /* parsetree->mergeTargetRelation unchanged (use expanded view) */
1787 :
1788 : /*
1789 : * For the most part, Vars referencing the view should remain as
1790 : * they are, meaning that they implicitly represent OLD values.
1791 : * But in the RETURNING list if any, we want such Vars to
1792 : * represent NEW values, so change them to reference the new RTE.
1793 : *
1794 : * Since ChangeVarNodes scribbles on the tree in-place, copy the
1795 : * RETURNING list first for safety.
1796 : */
1797 190 : parsetree->returningList = copyObject(parsetree->returningList);
1798 190 : ChangeVarNodes((Node *) parsetree->returningList, rt_index,
1799 : parsetree->resultRelation, 0);
1800 :
1801 : /*
1802 : * To allow the executor to compute the original view row to pass
1803 : * to the INSTEAD OF trigger, we add a resjunk whole-row Var
1804 : * referencing the original RTE. This will later get expanded
1805 : * into a RowExpr computing all the OLD values of the view row.
1806 : */
1807 190 : var = makeWholeRowVar(rte, rt_index, 0, false);
1808 190 : tle = makeTargetEntry((Expr *) var,
1809 190 : list_length(parsetree->targetList) + 1,
1810 : pstrdup("wholerow"),
1811 : true);
1812 :
1813 190 : parsetree->targetList = lappend(parsetree->targetList, tle);
1814 :
1815 : /* Now, continue with expanding the original view RTE */
1816 : }
1817 : else
1818 0 : elog(ERROR, "unrecognized commandType: %d",
1819 : (int) parsetree->commandType);
1820 : }
1821 :
1822 : /*
1823 : * Check if there's a FOR [KEY] UPDATE/SHARE clause applying to this view.
1824 : *
1825 : * Note: we needn't explicitly consider any such clauses appearing in
1826 : * ancestor query levels; their effects have already been pushed down to
1827 : * here by markQueryForLocking, and will be reflected in "rc".
1828 : */
1829 10619 : rc = get_parse_rowmark(parsetree, rt_index);
1830 :
1831 : /*
1832 : * Make a modifiable copy of the view query, and acquire needed locks on
1833 : * the relations it mentions. Force at least RowShareLock for all such
1834 : * rels if there's a FOR [KEY] UPDATE/SHARE clause affecting this view.
1835 : */
1836 10619 : rule_action = copyObject(linitial(rule->actions));
1837 :
1838 10619 : AcquireRewriteLocks(rule_action, true, (rc != NULL));
1839 :
1840 : /*
1841 : * If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as
1842 : * implicit FOR [KEY] UPDATE/SHARE, the same as the parser would have done
1843 : * if the view's subquery had been written out explicitly.
1844 : */
1845 10619 : if (rc != NULL)
1846 64 : markQueryForLocking(rule_action, (Node *) rule_action->jointree,
1847 : rc->strength, rc->waitPolicy, true);
1848 :
1849 : /*
1850 : * Recursively expand any view references inside the view.
1851 : */
1852 10619 : rule_action = fireRIRrules(rule_action, activeRIRs);
1853 :
1854 : /*
1855 : * Make sure the query is marked as having row security if the view query
1856 : * does.
1857 : */
1858 10599 : parsetree->hasRowSecurity |= rule_action->hasRowSecurity;
1859 :
1860 : /*
1861 : * Now, plug the view query in as a subselect, converting the relation's
1862 : * original RTE to a subquery RTE.
1863 : */
1864 10599 : rte = rt_fetch(rt_index, parsetree->rtable);
1865 :
1866 10599 : rte->rtekind = RTE_SUBQUERY;
1867 10599 : rte->subquery = rule_action;
1868 10599 : rte->security_barrier = RelationIsSecurityView(relation);
1869 :
1870 : /*
1871 : * Clear fields that should not be set in a subquery RTE. Note that we
1872 : * leave the relid, relkind, rellockmode, and perminfoindex fields set, so
1873 : * that the view relation can be appropriately locked before execution and
1874 : * its permissions checked.
1875 : */
1876 10599 : rte->tablesample = NULL;
1877 10599 : rte->inh = false; /* must not be set for a subquery */
1878 :
1879 : /*
1880 : * Since we allow CREATE OR REPLACE VIEW to add columns to a view, the
1881 : * rule_action might emit more columns than we expected when the current
1882 : * query was parsed. Various places expect rte->eref->colnames to be
1883 : * consistent with the non-junk output columns of the subquery, so patch
1884 : * things up if necessary by adding some dummy column names.
1885 : */
1886 10599 : numCols = ExecCleanTargetListLength(rule_action->targetList);
1887 10611 : while (list_length(rte->eref->colnames) < numCols)
1888 : {
1889 12 : rte->eref->colnames = lappend(rte->eref->colnames,
1890 12 : makeString(pstrdup("?column?")));
1891 : }
1892 :
1893 10599 : return parsetree;
1894 : }
1895 :
1896 : /*
1897 : * Recursively mark all relations used by a view as FOR [KEY] UPDATE/SHARE.
1898 : *
1899 : * This may generate an invalid query, eg if some sub-query uses an
1900 : * aggregate. We leave it to the planner to detect that.
1901 : *
1902 : * NB: this must agree with the parser's transformLockingClause() routine.
1903 : * However, we used to have to avoid marking a view's OLD and NEW rels for
1904 : * updating, which motivated scanning the jointree to determine which rels
1905 : * are used. Possibly that could now be simplified into just scanning the
1906 : * rangetable as the parser does.
1907 : */
1908 : static void
1909 128 : markQueryForLocking(Query *qry, Node *jtnode,
1910 : LockClauseStrength strength, LockWaitPolicy waitPolicy,
1911 : bool pushedDown)
1912 : {
1913 128 : if (jtnode == NULL)
1914 0 : return;
1915 128 : if (IsA(jtnode, RangeTblRef))
1916 : {
1917 64 : int rti = ((RangeTblRef *) jtnode)->rtindex;
1918 64 : RangeTblEntry *rte = rt_fetch(rti, qry->rtable);
1919 :
1920 64 : if (rte->rtekind == RTE_RELATION)
1921 : {
1922 : RTEPermissionInfo *perminfo;
1923 :
1924 64 : applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
1925 :
1926 64 : perminfo = getRTEPermissionInfo(qry->rteperminfos, rte);
1927 64 : perminfo->requiredPerms |= ACL_SELECT_FOR_UPDATE;
1928 : }
1929 0 : else if (rte->rtekind == RTE_SUBQUERY)
1930 : {
1931 0 : applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
1932 : /* FOR UPDATE/SHARE of subquery is propagated to subquery's rels */
1933 0 : markQueryForLocking(rte->subquery, (Node *) rte->subquery->jointree,
1934 : strength, waitPolicy, true);
1935 : }
1936 : /* other RTE types are unaffected by FOR UPDATE */
1937 : }
1938 64 : else if (IsA(jtnode, FromExpr))
1939 : {
1940 64 : FromExpr *f = (FromExpr *) jtnode;
1941 : ListCell *l;
1942 :
1943 128 : foreach(l, f->fromlist)
1944 64 : markQueryForLocking(qry, lfirst(l), strength, waitPolicy, pushedDown);
1945 : }
1946 0 : else if (IsA(jtnode, JoinExpr))
1947 : {
1948 0 : JoinExpr *j = (JoinExpr *) jtnode;
1949 :
1950 0 : markQueryForLocking(qry, j->larg, strength, waitPolicy, pushedDown);
1951 0 : markQueryForLocking(qry, j->rarg, strength, waitPolicy, pushedDown);
1952 : }
1953 : else
1954 0 : elog(ERROR, "unrecognized node type: %d",
1955 : (int) nodeTag(jtnode));
1956 : }
1957 :
1958 :
1959 : /*
1960 : * fireRIRonSubLink -
1961 : * Apply fireRIRrules() to each SubLink (subselect in expression) found
1962 : * in the given tree.
1963 : *
1964 : * NOTE: although this has the form of a walker, we cheat and modify the
1965 : * SubLink nodes in-place. It is caller's responsibility to ensure that
1966 : * no unwanted side-effects occur!
1967 : *
1968 : * This is unlike most of the other routines that recurse into subselects,
1969 : * because we must take control at the SubLink node in order to replace
1970 : * the SubLink's subselect link with the possibly-rewritten subquery.
1971 : */
1972 : static bool
1973 1942439 : fireRIRonSubLink(Node *node, fireRIRonSubLink_context *context)
1974 : {
1975 1942439 : if (node == NULL)
1976 386470 : return false;
1977 1555969 : if (IsA(node, SubLink))
1978 : {
1979 33571 : SubLink *sub = (SubLink *) node;
1980 :
1981 : /* Do what we came for */
1982 33571 : sub->subselect = (Node *) fireRIRrules((Query *) sub->subselect,
1983 : context->activeRIRs);
1984 :
1985 : /*
1986 : * Remember if any of the sublinks have row security.
1987 : */
1988 33519 : context->hasRowSecurity |= ((Query *) sub->subselect)->hasRowSecurity;
1989 :
1990 : /* Fall through to process lefthand args of SubLink */
1991 : }
1992 :
1993 : /*
1994 : * Do NOT recurse into Query nodes, because fireRIRrules already processed
1995 : * subselects of subselects for us.
1996 : */
1997 1555917 : return expression_tree_walker(node, fireRIRonSubLink, context);
1998 : }
1999 :
2000 :
2001 : /*
2002 : * fireRIRrules -
2003 : * Apply all RIR rules on each rangetable entry in the given query
2004 : *
2005 : * activeRIRs is a list of the OIDs of views we're already processing RIR
2006 : * rules for, used to detect/reject recursion.
2007 : */
2008 : static Query *
2009 370145 : fireRIRrules(Query *parsetree, List *activeRIRs)
2010 : {
2011 370145 : int origResultRelation = parsetree->resultRelation;
2012 : int rt_index;
2013 : ListCell *lc;
2014 :
2015 : /*
2016 : * Expand SEARCH and CYCLE clauses in CTEs.
2017 : *
2018 : * This is just a convenient place to do this, since we are already
2019 : * looking at each Query.
2020 : */
2021 372785 : foreach(lc, parsetree->cteList)
2022 : {
2023 2644 : CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc);
2024 :
2025 2644 : if (cte->search_clause || cte->cycle_clause)
2026 : {
2027 96 : cte = rewriteSearchAndCycle(cte);
2028 92 : lfirst(lc) = cte;
2029 : }
2030 : }
2031 :
2032 : /*
2033 : * don't try to convert this into a foreach loop, because rtable list can
2034 : * get changed each time through...
2035 : */
2036 370141 : rt_index = 0;
2037 841133 : while (rt_index < list_length(parsetree->rtable))
2038 : {
2039 : RangeTblEntry *rte;
2040 : Relation rel;
2041 : List *locks;
2042 : RuleLock *rules;
2043 : RewriteRule *rule;
2044 : int i;
2045 :
2046 471080 : ++rt_index;
2047 :
2048 471080 : rte = rt_fetch(rt_index, parsetree->rtable);
2049 :
2050 : /*
2051 : * Convert GRAPH_TABLE clause into a subquery using relational
2052 : * operators. (This will change the rtekind to subquery, so it must
2053 : * be done before the subquery handling below.)
2054 : */
2055 471080 : if (rte->rtekind == RTE_GRAPH_TABLE)
2056 : {
2057 481 : parsetree = rewriteGraphTable(parsetree, rt_index);
2058 : }
2059 :
2060 : /*
2061 : * A subquery RTE can't have associated rules, so there's nothing to
2062 : * do to this level of the query, but we must recurse into the
2063 : * subquery to expand any rule references in it.
2064 : */
2065 471040 : if (rte->rtekind == RTE_SUBQUERY)
2066 : {
2067 38826 : rte->subquery = fireRIRrules(rte->subquery, activeRIRs);
2068 :
2069 : /*
2070 : * While we are here, make sure the query is marked as having row
2071 : * security if any of its subqueries do.
2072 : */
2073 38802 : parsetree->hasRowSecurity |= rte->subquery->hasRowSecurity;
2074 :
2075 38802 : continue;
2076 : }
2077 :
2078 : /*
2079 : * Joins and other non-relation RTEs can be ignored completely.
2080 : */
2081 432214 : if (rte->rtekind != RTE_RELATION)
2082 109758 : continue;
2083 :
2084 : /*
2085 : * Always ignore RIR rules for materialized views referenced in
2086 : * queries. (This does not prevent refreshing MVs, since they aren't
2087 : * referenced in their own query definitions.)
2088 : *
2089 : * Note: in the future we might want to allow MVs to be conditionally
2090 : * expanded as if they were regular views, if they are not scannable.
2091 : * In that case this test would need to be postponed till after we've
2092 : * opened the rel, so that we could check its state.
2093 : */
2094 322456 : if (rte->relkind == RELKIND_MATVIEW)
2095 291 : continue;
2096 :
2097 : /*
2098 : * In INSERT ... ON CONFLICT, ignore the EXCLUDED pseudo-relation;
2099 : * even if it points to a view, we needn't expand it, and should not
2100 : * because we want the RTE to remain of RTE_RELATION type. Otherwise,
2101 : * it would get changed to RTE_SUBQUERY type, which is an
2102 : * untested/unsupported situation.
2103 : */
2104 322165 : if (parsetree->onConflict &&
2105 3102 : rt_index == parsetree->onConflict->exclRelIndex)
2106 1138 : continue;
2107 :
2108 : /*
2109 : * If the table is not referenced in the query, then we ignore it.
2110 : * This prevents infinite expansion loop due to new rtable entries
2111 : * inserted by expansion of a rule. A table is referenced if it is
2112 : * part of the join set (a source table), or is referenced by any Var
2113 : * nodes, or is the result table.
2114 : */
2115 321027 : if (rt_index != parsetree->resultRelation &&
2116 265659 : !rangeTableEntry_used((Node *) parsetree, rt_index, 0))
2117 4970 : continue;
2118 :
2119 : /*
2120 : * Also, if this is a new result relation introduced by
2121 : * ApplyRetrieveRule, we don't want to do anything more with it.
2122 : */
2123 316057 : if (rt_index == parsetree->resultRelation &&
2124 : rt_index != origResultRelation)
2125 190 : continue;
2126 :
2127 : /*
2128 : * We can use NoLock here since either the parser or
2129 : * AcquireRewriteLocks should have locked the rel already.
2130 : */
2131 315867 : rel = relation_open(rte->relid, NoLock);
2132 :
2133 : /*
2134 : * Collect the RIR rules that we must apply
2135 : */
2136 315867 : rules = rel->rd_rules;
2137 315867 : if (rules != NULL)
2138 : {
2139 11573 : locks = NIL;
2140 25134 : for (i = 0; i < rules->numLocks; i++)
2141 : {
2142 13561 : rule = rules->rules[i];
2143 13561 : if (rule->event != CMD_SELECT)
2144 2859 : continue;
2145 :
2146 10702 : locks = lappend(locks, rule);
2147 : }
2148 :
2149 : /*
2150 : * If we found any, apply them --- but first check for recursion!
2151 : */
2152 11573 : if (locks != NIL)
2153 : {
2154 : ListCell *l;
2155 :
2156 10702 : if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
2157 0 : ereport(ERROR,
2158 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2159 : errmsg("infinite recursion detected in rules for relation \"%s\"",
2160 : RelationGetRelationName(rel))));
2161 10702 : activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
2162 :
2163 21380 : foreach(l, locks)
2164 : {
2165 10702 : rule = lfirst(l);
2166 :
2167 10702 : parsetree = ApplyRetrieveRule(parsetree,
2168 : rule,
2169 : rt_index,
2170 : rel,
2171 : activeRIRs);
2172 : }
2173 :
2174 10678 : activeRIRs = list_delete_last(activeRIRs);
2175 : }
2176 : }
2177 :
2178 315843 : table_close(rel, NoLock);
2179 : }
2180 :
2181 : /* Recurse into subqueries in WITH */
2182 372693 : foreach(lc, parsetree->cteList)
2183 : {
2184 2640 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
2185 :
2186 2640 : cte->ctequery = (Node *)
2187 2640 : fireRIRrules((Query *) cte->ctequery, activeRIRs);
2188 :
2189 : /*
2190 : * While we are here, make sure the query is marked as having row
2191 : * security if any of its CTEs do.
2192 : */
2193 2640 : parsetree->hasRowSecurity |= ((Query *) cte->ctequery)->hasRowSecurity;
2194 : }
2195 :
2196 : /*
2197 : * Recurse into sublink subqueries, too. But we already did the ones in
2198 : * the rtable and cteList.
2199 : */
2200 370053 : if (parsetree->hasSubLinks)
2201 : {
2202 : fireRIRonSubLink_context context;
2203 :
2204 26948 : context.activeRIRs = activeRIRs;
2205 26948 : context.hasRowSecurity = false;
2206 :
2207 26948 : query_tree_walker(parsetree, fireRIRonSubLink, &context,
2208 : QTW_IGNORE_RC_SUBQUERIES);
2209 :
2210 : /*
2211 : * Make sure the query is marked as having row security if any of its
2212 : * sublinks do.
2213 : */
2214 26948 : parsetree->hasRowSecurity |= context.hasRowSecurity;
2215 : }
2216 :
2217 : /*
2218 : * Apply any row-level security policies. We do this last because it
2219 : * requires special recursion detection if the new quals have sublink
2220 : * subqueries, and if we did it in the loop above query_tree_walker would
2221 : * then recurse into those quals a second time.
2222 : */
2223 370053 : rt_index = 0;
2224 840905 : foreach(lc, parsetree->rtable)
2225 : {
2226 470992 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
2227 : Relation rel;
2228 : List *securityQuals;
2229 : List *withCheckOptions;
2230 : bool hasRowSecurity;
2231 : bool hasSubLinks;
2232 :
2233 470992 : ++rt_index;
2234 :
2235 : /* Only normal relations can have RLS policies */
2236 470992 : if (rte->rtekind != RTE_RELATION ||
2237 311833 : (rte->relkind != RELKIND_RELATION &&
2238 17636 : rte->relkind != RELKIND_PARTITIONED_TABLE))
2239 165016 : continue;
2240 :
2241 305976 : rel = relation_open(rte->relid, NoLock);
2242 :
2243 : /*
2244 : * Fetch any new security quals that must be applied to this RTE.
2245 : */
2246 305976 : get_row_security_policies(parsetree, rte, rt_index,
2247 : &securityQuals, &withCheckOptions,
2248 : &hasRowSecurity, &hasSubLinks);
2249 :
2250 305920 : if (securityQuals != NIL || withCheckOptions != NIL)
2251 : {
2252 2218 : if (hasSubLinks)
2253 : {
2254 : acquireLocksOnSubLinks_context context;
2255 : fireRIRonSubLink_context fire_context;
2256 :
2257 : /*
2258 : * Recursively process the new quals, checking for infinite
2259 : * recursion.
2260 : */
2261 536 : if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
2262 32 : ereport(ERROR,
2263 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2264 : errmsg("infinite recursion detected in policy for relation \"%s\"",
2265 : RelationGetRelationName(rel))));
2266 :
2267 504 : activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
2268 :
2269 : /*
2270 : * get_row_security_policies just passed back securityQuals
2271 : * and/or withCheckOptions, and there were SubLinks, make sure
2272 : * we lock any relations which are referenced.
2273 : *
2274 : * These locks would normally be acquired by the parser, but
2275 : * securityQuals and withCheckOptions are added post-parsing.
2276 : */
2277 504 : context.for_execute = true;
2278 504 : (void) acquireLocksOnSubLinks((Node *) securityQuals, &context);
2279 504 : (void) acquireLocksOnSubLinks((Node *) withCheckOptions,
2280 : &context);
2281 :
2282 : /*
2283 : * Now that we have the locks on anything added by
2284 : * get_row_security_policies, fire any RIR rules for them.
2285 : */
2286 504 : fire_context.activeRIRs = activeRIRs;
2287 504 : fire_context.hasRowSecurity = false;
2288 :
2289 504 : expression_tree_walker((Node *) securityQuals,
2290 : fireRIRonSubLink, &fire_context);
2291 :
2292 456 : expression_tree_walker((Node *) withCheckOptions,
2293 : fireRIRonSubLink, &fire_context);
2294 :
2295 : /*
2296 : * We can ignore the value of fire_context.hasRowSecurity
2297 : * since we only reach this code in cases where hasRowSecurity
2298 : * is already true.
2299 : */
2300 : Assert(hasRowSecurity);
2301 :
2302 452 : activeRIRs = list_delete_last(activeRIRs);
2303 : }
2304 :
2305 : /*
2306 : * Add the new security barrier quals to the start of the RTE's
2307 : * list so that they get applied before any existing barrier quals
2308 : * (which would have come from a security-barrier view, and should
2309 : * get lower priority than RLS conditions on the table itself).
2310 : */
2311 4268 : rte->securityQuals = list_concat(securityQuals,
2312 2134 : rte->securityQuals);
2313 :
2314 2134 : parsetree->withCheckOptions = list_concat(withCheckOptions,
2315 2134 : parsetree->withCheckOptions);
2316 : }
2317 :
2318 : /*
2319 : * Make sure the query is marked correctly if row-level security
2320 : * applies, or if the new quals had sublinks.
2321 : */
2322 305836 : if (hasRowSecurity)
2323 2602 : parsetree->hasRowSecurity = true;
2324 305836 : if (hasSubLinks)
2325 452 : parsetree->hasSubLinks = true;
2326 :
2327 305836 : table_close(rel, NoLock);
2328 : }
2329 :
2330 369913 : return parsetree;
2331 : }
2332 :
2333 :
2334 : /*
2335 : * Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its
2336 : * qualification. This is used to generate suitable "else clauses" for
2337 : * conditional INSTEAD rules. (Unfortunately we must use "x IS NOT TRUE",
2338 : * not just "NOT x" which the planner is much smarter about, else we will
2339 : * do the wrong thing when the qual evaluates to NULL.)
2340 : *
2341 : * The rule_qual may contain references to OLD or NEW. OLD references are
2342 : * replaced by references to the specified rt_index (the relation that the
2343 : * rule applies to). NEW references are only possible for INSERT and UPDATE
2344 : * queries on the relation itself, and so they should be replaced by copies
2345 : * of the related entries in the query's own targetlist.
2346 : */
2347 : static Query *
2348 296 : CopyAndAddInvertedQual(Query *parsetree,
2349 : Node *rule_qual,
2350 : int rt_index,
2351 : CmdType event)
2352 : {
2353 : /* Don't scribble on the passed qual (it's in the relcache!) */
2354 296 : Node *new_qual = copyObject(rule_qual);
2355 : acquireLocksOnSubLinks_context context;
2356 :
2357 296 : context.for_execute = true;
2358 :
2359 : /*
2360 : * In case there are subqueries in the qual, acquire necessary locks and
2361 : * fix any deleted JOIN RTE entries. (This is somewhat redundant with
2362 : * rewriteRuleAction, but not entirely ... consider restructuring so that
2363 : * we only need to process the qual this way once.)
2364 : */
2365 296 : (void) acquireLocksOnSubLinks(new_qual, &context);
2366 :
2367 : /* Fix references to OLD */
2368 296 : ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
2369 : /* Fix references to NEW */
2370 296 : if (event == CMD_INSERT || event == CMD_UPDATE)
2371 576 : new_qual = ReplaceVarsFromTargetList(new_qual,
2372 : PRS2_NEW_VARNO,
2373 : 0,
2374 288 : rt_fetch(rt_index,
2375 : parsetree->rtable),
2376 : parsetree->targetList,
2377 : parsetree->resultRelation,
2378 : (event == CMD_UPDATE) ?
2379 : REPLACEVARS_CHANGE_VARNO :
2380 : REPLACEVARS_SUBSTITUTE_NULL,
2381 : rt_index,
2382 : &parsetree->hasSubLinks);
2383 : /* And attach the fixed qual */
2384 296 : AddInvertedQual(parsetree, new_qual);
2385 :
2386 296 : return parsetree;
2387 : }
2388 :
2389 :
2390 : /*
2391 : * fireRules -
2392 : * Iterate through rule locks applying rules.
2393 : *
2394 : * Input arguments:
2395 : * parsetree - original query
2396 : * rt_index - RT index of result relation in original query
2397 : * event - type of rule event
2398 : * locks - list of rules to fire
2399 : * Output arguments:
2400 : * *instead_flag - set true if any unqualified INSTEAD rule is found
2401 : * (must be initialized to false)
2402 : * *returning_flag - set true if we rewrite RETURNING clause in any rule
2403 : * (must be initialized to false)
2404 : * *qual_product - filled with modified original query if any qualified
2405 : * INSTEAD rule is found (must be initialized to NULL)
2406 : * Return value:
2407 : * list of rule actions adjusted for use with this query
2408 : *
2409 : * Qualified INSTEAD rules generate their action with the qualification
2410 : * condition added. They also generate a modified version of the original
2411 : * query with the negated qualification added, so that it will run only for
2412 : * rows that the qualified action doesn't act on. (If there are multiple
2413 : * qualified INSTEAD rules, we AND all the negated quals onto a single
2414 : * modified original query.) We won't execute the original, unmodified
2415 : * query if we find either qualified or unqualified INSTEAD rules. If
2416 : * we find both, the modified original query is discarded too.
2417 : */
2418 : static List *
2419 58158 : fireRules(Query *parsetree,
2420 : int rt_index,
2421 : CmdType event,
2422 : List *locks,
2423 : bool *instead_flag,
2424 : bool *returning_flag,
2425 : Query **qual_product)
2426 : {
2427 58158 : List *results = NIL;
2428 : ListCell *l;
2429 :
2430 59198 : foreach(l, locks)
2431 : {
2432 1048 : RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
2433 1048 : Node *event_qual = rule_lock->qual;
2434 1048 : List *actions = rule_lock->actions;
2435 : QuerySource qsrc;
2436 : ListCell *r;
2437 :
2438 : /* Determine correct QuerySource value for actions */
2439 1048 : if (rule_lock->isInstead)
2440 : {
2441 792 : if (event_qual != NULL)
2442 300 : qsrc = QSRC_QUAL_INSTEAD_RULE;
2443 : else
2444 : {
2445 492 : qsrc = QSRC_INSTEAD_RULE;
2446 492 : *instead_flag = true; /* report unqualified INSTEAD */
2447 : }
2448 : }
2449 : else
2450 256 : qsrc = QSRC_NON_INSTEAD_RULE;
2451 :
2452 1048 : if (qsrc == QSRC_QUAL_INSTEAD_RULE)
2453 : {
2454 : /*
2455 : * If there are INSTEAD rules with qualifications, the original
2456 : * query is still performed. But all the negated rule
2457 : * qualifications of the INSTEAD rules are added so it does its
2458 : * actions only in cases where the rule quals of all INSTEAD rules
2459 : * are false. Think of it as the default action in a case. We save
2460 : * this in *qual_product so RewriteQuery() can add it to the query
2461 : * list after we mangled it up enough.
2462 : *
2463 : * If we have already found an unqualified INSTEAD rule, then
2464 : * *qual_product won't be used, so don't bother building it.
2465 : */
2466 300 : if (!*instead_flag)
2467 : {
2468 296 : if (*qual_product == NULL)
2469 240 : *qual_product = copyObject(parsetree);
2470 296 : *qual_product = CopyAndAddInvertedQual(*qual_product,
2471 : event_qual,
2472 : rt_index,
2473 : event);
2474 : }
2475 : }
2476 :
2477 : /* Now process the rule's actions and add them to the result list */
2478 2124 : foreach(r, actions)
2479 : {
2480 1084 : Query *rule_action = lfirst(r);
2481 :
2482 1084 : if (rule_action->commandType == CMD_NOTHING)
2483 140 : continue;
2484 :
2485 944 : rule_action = rewriteRuleAction(parsetree, rule_action,
2486 : event_qual, rt_index, event,
2487 : returning_flag);
2488 :
2489 936 : rule_action->querySource = qsrc;
2490 936 : rule_action->canSetTag = false; /* might change later */
2491 :
2492 936 : results = lappend(results, rule_action);
2493 : }
2494 : }
2495 :
2496 58150 : return results;
2497 : }
2498 :
2499 :
2500 : /*
2501 : * get_view_query - get the Query from a view's _RETURN rule.
2502 : *
2503 : * Caller should have verified that the relation is a view, and therefore
2504 : * we should find an ON SELECT action.
2505 : *
2506 : * Note that the pointer returned is into the relcache and therefore must
2507 : * be treated as read-only to the caller and not modified or scribbled on.
2508 : */
2509 : Query *
2510 3983 : get_view_query(Relation view)
2511 : {
2512 : int i;
2513 :
2514 : Assert(view->rd_rel->relkind == RELKIND_VIEW);
2515 :
2516 3983 : for (i = 0; i < view->rd_rules->numLocks; i++)
2517 : {
2518 3983 : RewriteRule *rule = view->rd_rules->rules[i];
2519 :
2520 3983 : if (rule->event == CMD_SELECT)
2521 : {
2522 : /* A _RETURN rule should have only one action */
2523 3983 : if (list_length(rule->actions) != 1)
2524 0 : elog(ERROR, "invalid _RETURN rule action specification");
2525 :
2526 3983 : return (Query *) linitial(rule->actions);
2527 : }
2528 : }
2529 :
2530 0 : elog(ERROR, "failed to find _RETURN rule for view");
2531 : return NULL; /* keep compiler quiet */
2532 : }
2533 :
2534 :
2535 : /*
2536 : * view_has_instead_trigger - does view have an INSTEAD OF trigger for event?
2537 : *
2538 : * If it does, we don't want to treat it as auto-updatable. This test can't
2539 : * be folded into view_query_is_auto_updatable because it's not an error
2540 : * condition.
2541 : *
2542 : * For MERGE, this will return true if there is an INSTEAD OF trigger for
2543 : * every action in mergeActionList, and false if there are any actions that
2544 : * lack an INSTEAD OF trigger. If there are no data-modifying MERGE actions
2545 : * (only DO NOTHING actions), true is returned so that the view is treated
2546 : * as trigger-updatable, rather than erroring out if it's not auto-updatable.
2547 : */
2548 : bool
2549 3708 : view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
2550 : {
2551 3708 : TriggerDesc *trigDesc = view->trigdesc;
2552 :
2553 3708 : switch (event)
2554 : {
2555 1234 : case CMD_INSERT:
2556 1234 : if (trigDesc && trigDesc->trig_insert_instead_row)
2557 174 : return true;
2558 1060 : break;
2559 1368 : case CMD_UPDATE:
2560 1368 : if (trigDesc && trigDesc->trig_update_instead_row)
2561 210 : return true;
2562 1158 : break;
2563 406 : case CMD_DELETE:
2564 406 : if (trigDesc && trigDesc->trig_delete_instead_row)
2565 70 : return true;
2566 336 : break;
2567 700 : case CMD_MERGE:
2568 988 : foreach_node(MergeAction, action, mergeActionList)
2569 : {
2570 780 : switch (action->commandType)
2571 : {
2572 136 : case CMD_INSERT:
2573 136 : if (!trigDesc || !trigDesc->trig_insert_instead_row)
2574 596 : return false;
2575 56 : break;
2576 496 : case CMD_UPDATE:
2577 496 : if (!trigDesc || !trigDesc->trig_update_instead_row)
2578 424 : return false;
2579 72 : break;
2580 108 : case CMD_DELETE:
2581 108 : if (!trigDesc || !trigDesc->trig_delete_instead_row)
2582 92 : return false;
2583 16 : break;
2584 40 : case CMD_NOTHING:
2585 : /* No trigger required */
2586 40 : break;
2587 0 : default:
2588 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
2589 : break;
2590 : }
2591 : }
2592 104 : return true; /* no actions without an INSTEAD OF trigger */
2593 0 : default:
2594 0 : elog(ERROR, "unrecognized CmdType: %d", (int) event);
2595 : break;
2596 : }
2597 2554 : return false;
2598 : }
2599 :
2600 :
2601 : /*
2602 : * view_col_is_auto_updatable - test whether the specified column of a view
2603 : * is auto-updatable. Returns NULL (if the column can be updated) or a message
2604 : * string giving the reason that it cannot be.
2605 : *
2606 : * The returned string has not been translated; if it is shown as an error
2607 : * message, the caller should apply _() to translate it.
2608 : *
2609 : * Note that the checks performed here are local to this view. We do not check
2610 : * whether the referenced column of the underlying base relation is updatable.
2611 : */
2612 : static const char *
2613 9784 : view_col_is_auto_updatable(RangeTblRef *rtr, TargetEntry *tle)
2614 : {
2615 9784 : Var *var = (Var *) tle->expr;
2616 :
2617 : /*
2618 : * For now, the only updatable columns we support are those that are Vars
2619 : * referring to user columns of the underlying base relation.
2620 : *
2621 : * The view targetlist may contain resjunk columns (e.g., a view defined
2622 : * like "SELECT * FROM t ORDER BY a+b" is auto-updatable) but such columns
2623 : * are not auto-updatable, and in fact should never appear in the outer
2624 : * query's targetlist.
2625 : */
2626 9784 : if (tle->resjunk)
2627 120 : return gettext_noop("Junk view columns are not updatable.");
2628 :
2629 9664 : if (!IsA(var, Var) ||
2630 8684 : var->varno != rtr->rtindex ||
2631 8684 : var->varlevelsup != 0)
2632 980 : return gettext_noop("View columns that are not columns of their base relation are not updatable.");
2633 :
2634 8684 : if (var->varattno < 0)
2635 268 : return gettext_noop("View columns that refer to system columns are not updatable.");
2636 :
2637 8416 : if (var->varattno == 0)
2638 0 : return gettext_noop("View columns that return whole-row references are not updatable.");
2639 :
2640 8416 : return NULL; /* the view column is updatable */
2641 : }
2642 :
2643 :
2644 : /*
2645 : * view_query_is_auto_updatable - test whether the specified view definition
2646 : * represents an auto-updatable view. Returns NULL (if the view can be updated)
2647 : * or a message string giving the reason that it cannot be.
2648 : *
2649 : * The returned string has not been translated; if it is shown as an error
2650 : * message, the caller should apply _() to translate it.
2651 : *
2652 : * If check_cols is true, the view is required to have at least one updatable
2653 : * column (necessary for INSERT/UPDATE). Otherwise the view's columns are not
2654 : * checked for updatability. See also view_cols_are_auto_updatable.
2655 : *
2656 : * Note that the checks performed here are only based on the view definition.
2657 : * We do not check whether any base relations referred to by the view are
2658 : * updatable.
2659 : */
2660 : const char *
2661 3830 : view_query_is_auto_updatable(Query *viewquery, bool check_cols)
2662 : {
2663 : RangeTblRef *rtr;
2664 : RangeTblEntry *base_rte;
2665 :
2666 : /*----------
2667 : * Check if the view is simply updatable. According to SQL-92 this means:
2668 : * - No DISTINCT clause.
2669 : * - Each TLE is a column reference, and each column appears at most once.
2670 : * - FROM contains exactly one base relation.
2671 : * - No GROUP BY or HAVING clauses.
2672 : * - No set operations (UNION, INTERSECT or EXCEPT).
2673 : * - No sub-queries in the WHERE clause that reference the target table.
2674 : *
2675 : * We ignore that last restriction since it would be complex to enforce
2676 : * and there isn't any actual benefit to disallowing sub-queries. (The
2677 : * semantic issues that the standard is presumably concerned about don't
2678 : * arise in Postgres, since any such sub-query will not see any updates
2679 : * executed by the outer query anyway, thanks to MVCC snapshotting.)
2680 : *
2681 : * We also relax the second restriction by supporting part of SQL:1999
2682 : * feature T111, which allows for a mix of updatable and non-updatable
2683 : * columns, provided that an INSERT or UPDATE doesn't attempt to assign to
2684 : * a non-updatable column.
2685 : *
2686 : * In addition we impose these constraints, involving features that are
2687 : * not part of SQL-92:
2688 : * - No CTEs (WITH clauses).
2689 : * - No OFFSET or LIMIT clauses (this matches a SQL:2008 restriction).
2690 : * - No system columns (including whole-row references) in the tlist.
2691 : * - No window functions in the tlist.
2692 : * - No set-returning functions in the tlist.
2693 : *
2694 : * Note that we do these checks without recursively expanding the view.
2695 : * If the base relation is a view, we'll recursively deal with it later.
2696 : *----------
2697 : */
2698 3830 : if (viewquery->distinctClause != NIL)
2699 48 : return gettext_noop("Views containing DISTINCT are not automatically updatable.");
2700 :
2701 3782 : if (viewquery->groupClause != NIL || viewquery->groupingSets)
2702 24 : return gettext_noop("Views containing GROUP BY are not automatically updatable.");
2703 :
2704 3758 : if (viewquery->havingQual != NULL)
2705 20 : return gettext_noop("Views containing HAVING are not automatically updatable.");
2706 :
2707 3738 : if (viewquery->setOperations != NULL)
2708 24 : return gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not automatically updatable.");
2709 :
2710 3714 : if (viewquery->cteList != NIL)
2711 24 : return gettext_noop("Views containing WITH are not automatically updatable.");
2712 :
2713 3690 : if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL)
2714 384 : return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
2715 :
2716 : /*
2717 : * We must not allow window functions or set returning functions in the
2718 : * targetlist. Otherwise we might end up inserting them into the quals of
2719 : * the main query. We must also check for aggregates in the targetlist in
2720 : * case they appear without a GROUP BY.
2721 : *
2722 : * These restrictions ensure that each row of the view corresponds to a
2723 : * unique row in the underlying base relation.
2724 : */
2725 3306 : if (viewquery->hasAggs)
2726 20 : return gettext_noop("Views that return aggregate functions are not automatically updatable.");
2727 :
2728 3286 : if (viewquery->hasWindowFuncs)
2729 24 : return gettext_noop("Views that return window functions are not automatically updatable.");
2730 :
2731 3262 : if (viewquery->hasTargetSRFs)
2732 28 : return gettext_noop("Views that return set-returning functions are not automatically updatable.");
2733 :
2734 : /*
2735 : * The view query should select from a single base relation, which must be
2736 : * a table or another view.
2737 : */
2738 3234 : if (list_length(viewquery->jointree->fromlist) != 1)
2739 44 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2740 :
2741 3190 : rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
2742 3190 : if (!IsA(rtr, RangeTblRef))
2743 0 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2744 :
2745 3190 : base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
2746 3190 : if (base_rte->rtekind != RTE_RELATION ||
2747 3114 : (base_rte->relkind != RELKIND_RELATION &&
2748 1197 : base_rte->relkind != RELKIND_FOREIGN_TABLE &&
2749 1186 : base_rte->relkind != RELKIND_VIEW &&
2750 166 : base_rte->relkind != RELKIND_PARTITIONED_TABLE))
2751 104 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2752 :
2753 3086 : if (base_rte->tablesample)
2754 4 : return gettext_noop("Views containing TABLESAMPLE are not automatically updatable.");
2755 :
2756 : /*
2757 : * Check that the view has at least one updatable column. This is required
2758 : * for INSERT/UPDATE but not for DELETE.
2759 : */
2760 3082 : if (check_cols)
2761 : {
2762 : ListCell *cell;
2763 : bool found;
2764 :
2765 2126 : found = false;
2766 2250 : foreach(cell, viewquery->targetList)
2767 : {
2768 2250 : TargetEntry *tle = (TargetEntry *) lfirst(cell);
2769 :
2770 2250 : if (view_col_is_auto_updatable(rtr, tle) == NULL)
2771 : {
2772 2126 : found = true;
2773 2126 : break;
2774 : }
2775 : }
2776 :
2777 2126 : if (!found)
2778 0 : return gettext_noop("Views that have no updatable columns are not automatically updatable.");
2779 : }
2780 :
2781 3082 : return NULL; /* the view is updatable */
2782 : }
2783 :
2784 :
2785 : /*
2786 : * view_cols_are_auto_updatable - test whether all of the required columns of
2787 : * an auto-updatable view are actually updatable. Returns NULL (if all the
2788 : * required columns can be updated) or a message string giving the reason that
2789 : * they cannot be.
2790 : *
2791 : * The returned string has not been translated; if it is shown as an error
2792 : * message, the caller should apply _() to translate it.
2793 : *
2794 : * This should be used for INSERT/UPDATE to ensure that we don't attempt to
2795 : * assign to any non-updatable columns.
2796 : *
2797 : * Additionally it may be used to retrieve the set of updatable columns in the
2798 : * view, or if one or more of the required columns is not updatable, the name
2799 : * of the first offending non-updatable column.
2800 : *
2801 : * The caller must have already verified that this is an auto-updatable view
2802 : * using view_query_is_auto_updatable.
2803 : *
2804 : * Note that the checks performed here are only based on the view definition.
2805 : * We do not check whether the referenced columns of the base relation are
2806 : * updatable.
2807 : */
2808 : static const char *
2809 2726 : view_cols_are_auto_updatable(Query *viewquery,
2810 : Bitmapset *required_cols,
2811 : Bitmapset **updatable_cols,
2812 : char **non_updatable_col)
2813 : {
2814 : RangeTblRef *rtr;
2815 : AttrNumber col;
2816 : ListCell *cell;
2817 :
2818 : /*
2819 : * The caller should have verified that this view is auto-updatable and so
2820 : * there should be a single base relation.
2821 : */
2822 : Assert(list_length(viewquery->jointree->fromlist) == 1);
2823 2726 : rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
2824 :
2825 : /* Initialize the optional return values */
2826 2726 : if (updatable_cols != NULL)
2827 700 : *updatable_cols = NULL;
2828 2726 : if (non_updatable_col != NULL)
2829 2026 : *non_updatable_col = NULL;
2830 :
2831 : /* Test each view column for updatability */
2832 2726 : col = -FirstLowInvalidHeapAttributeNumber;
2833 10180 : foreach(cell, viewquery->targetList)
2834 : {
2835 7534 : TargetEntry *tle = (TargetEntry *) lfirst(cell);
2836 : const char *col_update_detail;
2837 :
2838 7534 : col++;
2839 7534 : col_update_detail = view_col_is_auto_updatable(rtr, tle);
2840 :
2841 7534 : if (col_update_detail == NULL)
2842 : {
2843 : /* The column is updatable */
2844 6290 : if (updatable_cols != NULL)
2845 1424 : *updatable_cols = bms_add_member(*updatable_cols, col);
2846 : }
2847 1244 : else if (bms_is_member(col, required_cols))
2848 : {
2849 : /* The required column is not updatable */
2850 80 : if (non_updatable_col != NULL)
2851 80 : *non_updatable_col = tle->resname;
2852 80 : return col_update_detail;
2853 : }
2854 : }
2855 :
2856 2646 : return NULL; /* all the required view columns are updatable */
2857 : }
2858 :
2859 :
2860 : /*
2861 : * relation_is_updatable - determine which update events the specified
2862 : * relation supports.
2863 : *
2864 : * Note that views may contain a mix of updatable and non-updatable columns.
2865 : * For a view to support INSERT/UPDATE it must have at least one updatable
2866 : * column, but there is no such restriction for DELETE. If include_cols is
2867 : * non-NULL, then only the specified columns are considered when testing for
2868 : * updatability.
2869 : *
2870 : * Unlike the preceding functions, this does recurse to look at a view's
2871 : * base relations, so it needs to detect recursion. To do that, we pass
2872 : * a list of currently-considered outer relations. External callers need
2873 : * only pass NIL.
2874 : *
2875 : * This is used for the information_schema views, which have separate concepts
2876 : * of "updatable" and "trigger updatable". A relation is "updatable" if it
2877 : * can be updated without the need for triggers (either because it has a
2878 : * suitable RULE, or because it is simple enough to be automatically updated).
2879 : * A relation is "trigger updatable" if it has a suitable INSTEAD OF trigger.
2880 : * The SQL standard regards this as not necessarily updatable, presumably
2881 : * because there is no way of knowing what the trigger will actually do.
2882 : * The information_schema views therefore call this function with
2883 : * include_triggers = false. However, other callers might only care whether
2884 : * data-modifying SQL will work, so they can pass include_triggers = true
2885 : * to have trigger updatability included in the result.
2886 : *
2887 : * The return value is a bitmask of rule event numbers indicating which of
2888 : * the INSERT, UPDATE and DELETE operations are supported. (We do it this way
2889 : * so that we can test for UPDATE plus DELETE support in a single call.)
2890 : */
2891 : int
2892 1408 : relation_is_updatable(Oid reloid,
2893 : List *outer_reloids,
2894 : bool include_triggers,
2895 : Bitmapset *include_cols)
2896 : {
2897 1408 : int events = 0;
2898 : Relation rel;
2899 : RuleLock *rulelocks;
2900 :
2901 : #define ALL_EVENTS ((1 << CMD_INSERT) | (1 << CMD_UPDATE) | (1 << CMD_DELETE))
2902 :
2903 : /* Since this function recurses, it could be driven to stack overflow */
2904 1408 : check_stack_depth();
2905 :
2906 1408 : rel = try_relation_open(reloid, AccessShareLock);
2907 :
2908 : /*
2909 : * If the relation doesn't exist, return zero rather than throwing an
2910 : * error. This is helpful since scanning an information_schema view under
2911 : * MVCC rules can result in referencing rels that have actually been
2912 : * deleted already.
2913 : */
2914 1408 : if (rel == NULL)
2915 0 : return 0;
2916 :
2917 : /* If we detect a recursive view, report that it is not updatable */
2918 1408 : if (list_member_oid(outer_reloids, RelationGetRelid(rel)))
2919 : {
2920 0 : relation_close(rel, AccessShareLock);
2921 0 : return 0;
2922 : }
2923 :
2924 : /* If the relation is a table, it is always updatable */
2925 1408 : if (rel->rd_rel->relkind == RELKIND_RELATION ||
2926 1408 : rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
2927 : {
2928 12 : relation_close(rel, AccessShareLock);
2929 12 : return ALL_EVENTS;
2930 : }
2931 :
2932 : /* Look for unconditional DO INSTEAD rules, and note supported events */
2933 1396 : rulelocks = rel->rd_rules;
2934 1396 : if (rulelocks != NULL)
2935 : {
2936 : int i;
2937 :
2938 3040 : for (i = 0; i < rulelocks->numLocks; i++)
2939 : {
2940 1644 : if (rulelocks->rules[i]->isInstead &&
2941 1636 : rulelocks->rules[i]->qual == NULL)
2942 : {
2943 1636 : events |= ((1 << rulelocks->rules[i]->event) & ALL_EVENTS);
2944 : }
2945 : }
2946 :
2947 : /* If we have rules for all events, we're done */
2948 1396 : if (events == ALL_EVENTS)
2949 : {
2950 40 : relation_close(rel, AccessShareLock);
2951 40 : return events;
2952 : }
2953 : }
2954 :
2955 : /* Similarly look for INSTEAD OF triggers, if they are to be included */
2956 1356 : if (include_triggers)
2957 : {
2958 0 : TriggerDesc *trigDesc = rel->trigdesc;
2959 :
2960 0 : if (trigDesc)
2961 : {
2962 0 : if (trigDesc->trig_insert_instead_row)
2963 0 : events |= (1 << CMD_INSERT);
2964 0 : if (trigDesc->trig_update_instead_row)
2965 0 : events |= (1 << CMD_UPDATE);
2966 0 : if (trigDesc->trig_delete_instead_row)
2967 0 : events |= (1 << CMD_DELETE);
2968 :
2969 : /* If we have triggers for all events, we're done */
2970 0 : if (events == ALL_EVENTS)
2971 : {
2972 0 : relation_close(rel, AccessShareLock);
2973 0 : return events;
2974 : }
2975 : }
2976 : }
2977 :
2978 : /* If this is a foreign table, check which update events it supports */
2979 1356 : if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
2980 : {
2981 0 : FdwRoutine *fdwroutine = GetFdwRoutineForRelation(rel, false);
2982 :
2983 0 : if (fdwroutine->IsForeignRelUpdatable != NULL)
2984 0 : events |= fdwroutine->IsForeignRelUpdatable(rel);
2985 : else
2986 : {
2987 : /* Assume presence of executor functions is sufficient */
2988 0 : if (fdwroutine->ExecForeignInsert != NULL)
2989 0 : events |= (1 << CMD_INSERT);
2990 0 : if (fdwroutine->ExecForeignUpdate != NULL)
2991 0 : events |= (1 << CMD_UPDATE);
2992 0 : if (fdwroutine->ExecForeignDelete != NULL)
2993 0 : events |= (1 << CMD_DELETE);
2994 : }
2995 :
2996 0 : relation_close(rel, AccessShareLock);
2997 0 : return events;
2998 : }
2999 :
3000 : /* Check if this is an automatically updatable view */
3001 1356 : if (rel->rd_rel->relkind == RELKIND_VIEW)
3002 : {
3003 1356 : Query *viewquery = get_view_query(rel);
3004 :
3005 1356 : if (view_query_is_auto_updatable(viewquery, false) == NULL)
3006 : {
3007 : Bitmapset *updatable_cols;
3008 : int auto_events;
3009 : RangeTblRef *rtr;
3010 : RangeTblEntry *base_rte;
3011 : Oid baseoid;
3012 :
3013 : /*
3014 : * Determine which of the view's columns are updatable. If there
3015 : * are none within the set of columns we are looking at, then the
3016 : * view doesn't support INSERT/UPDATE, but it may still support
3017 : * DELETE.
3018 : */
3019 700 : view_cols_are_auto_updatable(viewquery, NULL,
3020 : &updatable_cols, NULL);
3021 :
3022 700 : if (include_cols != NULL)
3023 384 : updatable_cols = bms_int_members(updatable_cols, include_cols);
3024 :
3025 700 : if (bms_is_empty(updatable_cols))
3026 100 : auto_events = (1 << CMD_DELETE); /* May support DELETE */
3027 : else
3028 600 : auto_events = ALL_EVENTS; /* May support all events */
3029 :
3030 : /*
3031 : * The base relation must also support these update commands.
3032 : * Tables are always updatable, but for any other kind of base
3033 : * relation we must do a recursive check limited to the columns
3034 : * referenced by the locally updatable columns in this view.
3035 : */
3036 700 : rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
3037 700 : base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
3038 : Assert(base_rte->rtekind == RTE_RELATION);
3039 :
3040 700 : if (base_rte->relkind != RELKIND_RELATION &&
3041 388 : base_rte->relkind != RELKIND_PARTITIONED_TABLE)
3042 : {
3043 368 : baseoid = base_rte->relid;
3044 368 : outer_reloids = lappend_oid(outer_reloids,
3045 : RelationGetRelid(rel));
3046 368 : include_cols = adjust_view_column_set(updatable_cols,
3047 : viewquery->targetList);
3048 368 : auto_events &= relation_is_updatable(baseoid,
3049 : outer_reloids,
3050 : include_triggers,
3051 : include_cols);
3052 368 : outer_reloids = list_delete_last(outer_reloids);
3053 : }
3054 700 : events |= auto_events;
3055 : }
3056 : }
3057 :
3058 : /* If we reach here, the relation may support some update commands */
3059 1356 : relation_close(rel, AccessShareLock);
3060 1356 : return events;
3061 : }
3062 :
3063 :
3064 : /*
3065 : * adjust_view_column_set - map a set of column numbers according to targetlist
3066 : *
3067 : * This is used with simply-updatable views to map column-permissions sets for
3068 : * the view columns onto the matching columns in the underlying base relation.
3069 : * Relevant entries in the targetlist must be plain Vars of the underlying
3070 : * relation (as per the checks above in view_query_is_auto_updatable).
3071 : */
3072 : static Bitmapset *
3073 4764 : adjust_view_column_set(Bitmapset *cols, List *targetlist)
3074 : {
3075 4764 : Bitmapset *result = NULL;
3076 : int col;
3077 :
3078 4764 : col = -1;
3079 8264 : while ((col = bms_next_member(cols, col)) >= 0)
3080 : {
3081 : /* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
3082 3500 : AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
3083 :
3084 3500 : if (attno == InvalidAttrNumber)
3085 : {
3086 : /*
3087 : * There's a whole-row reference to the view. For permissions
3088 : * purposes, treat it as a reference to each column available from
3089 : * the view. (We should *not* convert this to a whole-row
3090 : * reference to the base relation, since the view may not touch
3091 : * all columns of the base relation.)
3092 : */
3093 : ListCell *lc;
3094 :
3095 0 : foreach(lc, targetlist)
3096 : {
3097 0 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
3098 : Var *var;
3099 :
3100 0 : if (tle->resjunk)
3101 0 : continue;
3102 0 : var = castNode(Var, tle->expr);
3103 0 : result = bms_add_member(result,
3104 0 : var->varattno - FirstLowInvalidHeapAttributeNumber);
3105 : }
3106 : }
3107 : else
3108 : {
3109 : /*
3110 : * Views do not have system columns, so we do not expect to see
3111 : * any other system attnos here. If we do find one, the error
3112 : * case will apply.
3113 : */
3114 3500 : TargetEntry *tle = get_tle_by_resno(targetlist, attno);
3115 :
3116 3500 : if (tle != NULL && !tle->resjunk && IsA(tle->expr, Var))
3117 3500 : {
3118 3500 : Var *var = (Var *) tle->expr;
3119 :
3120 3500 : result = bms_add_member(result,
3121 3500 : var->varattno - FirstLowInvalidHeapAttributeNumber);
3122 : }
3123 : else
3124 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3125 : attno);
3126 : }
3127 : }
3128 :
3129 4764 : return result;
3130 : }
3131 :
3132 :
3133 : /*
3134 : * error_view_not_updatable -
3135 : * Report an error due to an attempt to update a non-updatable view.
3136 : *
3137 : * Generally this is expected to be called from the rewriter, with suitable
3138 : * error detail explaining why the view is not updatable. Note, however, that
3139 : * the executor also performs a just-in-case check that the target view is
3140 : * updatable. That check is expected to never fail, but if it does, it will
3141 : * call this function with NULL error detail --- see CheckValidResultRel().
3142 : *
3143 : * Note: for MERGE, at least one of the actions in mergeActionList is expected
3144 : * to lack a suitable INSTEAD OF trigger --- see view_has_instead_trigger().
3145 : */
3146 : void
3147 104 : error_view_not_updatable(Relation view,
3148 : CmdType command,
3149 : List *mergeActionList,
3150 : const char *detail)
3151 : {
3152 104 : TriggerDesc *trigDesc = view->trigdesc;
3153 :
3154 104 : switch (command)
3155 : {
3156 16 : case CMD_INSERT:
3157 16 : ereport(ERROR,
3158 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3159 : errmsg("cannot insert into view \"%s\"",
3160 : RelationGetRelationName(view)),
3161 : detail ? errdetail_internal("%s", _(detail)) : 0,
3162 : errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
3163 : break;
3164 36 : case CMD_UPDATE:
3165 36 : ereport(ERROR,
3166 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3167 : errmsg("cannot update view \"%s\"",
3168 : RelationGetRelationName(view)),
3169 : detail ? errdetail_internal("%s", _(detail)) : 0,
3170 : errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
3171 : break;
3172 32 : case CMD_DELETE:
3173 32 : ereport(ERROR,
3174 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3175 : errmsg("cannot delete from view \"%s\"",
3176 : RelationGetRelationName(view)),
3177 : detail ? errdetail_internal("%s", _(detail)) : 0,
3178 : errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
3179 : break;
3180 20 : case CMD_MERGE:
3181 :
3182 : /*
3183 : * Note that the error hints here differ from above, since MERGE
3184 : * doesn't support rules.
3185 : */
3186 24 : foreach_node(MergeAction, action, mergeActionList)
3187 : {
3188 24 : switch (action->commandType)
3189 : {
3190 8 : case CMD_INSERT:
3191 8 : if (!trigDesc || !trigDesc->trig_insert_instead_row)
3192 8 : ereport(ERROR,
3193 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3194 : errmsg("cannot insert into view \"%s\"",
3195 : RelationGetRelationName(view)),
3196 : detail ? errdetail_internal("%s", _(detail)) : 0,
3197 : errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
3198 0 : break;
3199 8 : case CMD_UPDATE:
3200 8 : if (!trigDesc || !trigDesc->trig_update_instead_row)
3201 4 : ereport(ERROR,
3202 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3203 : errmsg("cannot update view \"%s\"",
3204 : RelationGetRelationName(view)),
3205 : detail ? errdetail_internal("%s", _(detail)) : 0,
3206 : errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
3207 4 : break;
3208 8 : case CMD_DELETE:
3209 8 : if (!trigDesc || !trigDesc->trig_delete_instead_row)
3210 8 : ereport(ERROR,
3211 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3212 : errmsg("cannot delete from view \"%s\"",
3213 : RelationGetRelationName(view)),
3214 : detail ? errdetail_internal("%s", _(detail)) : 0,
3215 : errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
3216 0 : break;
3217 0 : case CMD_NOTHING:
3218 0 : break;
3219 0 : default:
3220 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
3221 : break;
3222 : }
3223 : }
3224 0 : break;
3225 0 : default:
3226 0 : elog(ERROR, "unrecognized CmdType: %d", (int) command);
3227 : break;
3228 : }
3229 0 : }
3230 :
3231 :
3232 : /*
3233 : * rewriteTargetView -
3234 : * Attempt to rewrite a query where the target relation is a view, so that
3235 : * the view's base relation becomes the target relation.
3236 : *
3237 : * Note that the base relation here may itself be a view, which may or may not
3238 : * have INSTEAD OF triggers or rules to handle the update. That is handled by
3239 : * the recursion in RewriteQuery.
3240 : */
3241 : static Query *
3242 2378 : rewriteTargetView(Query *parsetree, Relation view)
3243 : {
3244 : Query *viewquery;
3245 : bool insert_or_update;
3246 : const char *auto_update_detail;
3247 : RangeTblRef *rtr;
3248 : int base_rt_index;
3249 : int new_rt_index;
3250 : RangeTblEntry *base_rte;
3251 : RangeTblEntry *view_rte;
3252 : RangeTblEntry *new_rte;
3253 : RTEPermissionInfo *base_perminfo;
3254 : RTEPermissionInfo *view_perminfo;
3255 : RTEPermissionInfo *new_perminfo;
3256 : Relation base_rel;
3257 : List *view_targetlist;
3258 : ListCell *lc;
3259 :
3260 : /*
3261 : * Get the Query from the view's ON SELECT rule. We're going to munge the
3262 : * Query to change the view's base relation into the target relation,
3263 : * along with various other changes along the way, so we need to make a
3264 : * copy of it (get_view_query() returns a pointer into the relcache, so we
3265 : * have to treat it as read-only).
3266 : */
3267 2378 : viewquery = copyObject(get_view_query(view));
3268 :
3269 : /* Locate RTE and perminfo describing the view in the outer query */
3270 2378 : view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
3271 2378 : view_perminfo = getRTEPermissionInfo(parsetree->rteperminfos, view_rte);
3272 :
3273 : /*
3274 : * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE? If so,
3275 : * various additional checks on the view columns need to be applied, and
3276 : * any view CHECK OPTIONs need to be enforced.
3277 : */
3278 2378 : insert_or_update =
3279 3900 : (parsetree->commandType == CMD_INSERT ||
3280 1522 : parsetree->commandType == CMD_UPDATE);
3281 :
3282 2378 : if (parsetree->commandType == CMD_MERGE)
3283 : {
3284 1284 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3285 : {
3286 628 : if (action->commandType == CMD_INSERT ||
3287 556 : action->commandType == CMD_UPDATE)
3288 : {
3289 536 : insert_or_update = true;
3290 536 : break;
3291 : }
3292 : }
3293 : }
3294 :
3295 : /* Check if the expansion of non-system views are restricted */
3296 2378 : if (unlikely((restrict_nonsystem_relation_kind & RESTRICT_RELKIND_VIEW) != 0 &&
3297 : RelationGetRelid(view) >= FirstNormalObjectId))
3298 4 : ereport(ERROR,
3299 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3300 : errmsg("access to non-system view \"%s\" is restricted",
3301 : RelationGetRelationName(view))));
3302 :
3303 : /*
3304 : * The view must be updatable, else fail.
3305 : *
3306 : * If we are doing INSERT/UPDATE (or MERGE containing INSERT/UPDATE), we
3307 : * also check that there is at least one updatable column.
3308 : */
3309 : auto_update_detail =
3310 2374 : view_query_is_auto_updatable(viewquery, insert_or_update);
3311 :
3312 2374 : if (auto_update_detail)
3313 92 : error_view_not_updatable(view,
3314 : parsetree->commandType,
3315 : parsetree->mergeActionList,
3316 : auto_update_detail);
3317 :
3318 : /*
3319 : * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
3320 : * columns must all be updatable.
3321 : */
3322 2282 : if (insert_or_update)
3323 : {
3324 : Bitmapset *modified_cols;
3325 : char *non_updatable_col;
3326 :
3327 : /*
3328 : * Compute the set of modified columns as those listed in the result
3329 : * RTE's insertedCols and/or updatedCols sets plus those that are
3330 : * targets of the query's targetlist(s). We must consider the query's
3331 : * targetlist because rewriteTargetListIU may have added additional
3332 : * targetlist entries for view defaults, and these must also be
3333 : * updatable. But rewriteTargetListIU can also remove entries if they
3334 : * are DEFAULT markers and the column's default is NULL, so
3335 : * considering only the targetlist would also be wrong.
3336 : */
3337 2026 : modified_cols = bms_union(view_perminfo->insertedCols,
3338 2026 : view_perminfo->updatedCols);
3339 :
3340 4302 : foreach(lc, parsetree->targetList)
3341 : {
3342 2276 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3343 :
3344 2276 : if (!tle->resjunk)
3345 2276 : modified_cols = bms_add_member(modified_cols,
3346 2276 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3347 : }
3348 :
3349 2026 : if (parsetree->onConflict)
3350 : {
3351 280 : foreach(lc, parsetree->onConflict->onConflictSet)
3352 : {
3353 108 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3354 :
3355 108 : if (!tle->resjunk)
3356 108 : modified_cols = bms_add_member(modified_cols,
3357 108 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3358 : }
3359 : }
3360 :
3361 4704 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3362 : {
3363 652 : if (action->commandType == CMD_INSERT ||
3364 512 : action->commandType == CMD_UPDATE)
3365 : {
3366 1964 : foreach_node(TargetEntry, tle, action->targetList)
3367 : {
3368 756 : if (!tle->resjunk)
3369 756 : modified_cols = bms_add_member(modified_cols,
3370 756 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3371 : }
3372 : }
3373 : }
3374 :
3375 2026 : auto_update_detail = view_cols_are_auto_updatable(viewquery,
3376 : modified_cols,
3377 : NULL,
3378 : &non_updatable_col);
3379 2026 : if (auto_update_detail)
3380 : {
3381 : /*
3382 : * This is a different error, caused by an attempt to update a
3383 : * non-updatable column in an otherwise updatable view.
3384 : */
3385 80 : switch (parsetree->commandType)
3386 : {
3387 48 : case CMD_INSERT:
3388 48 : ereport(ERROR,
3389 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3390 : errmsg("cannot insert into column \"%s\" of view \"%s\"",
3391 : non_updatable_col,
3392 : RelationGetRelationName(view)),
3393 : errdetail_internal("%s", _(auto_update_detail))));
3394 : break;
3395 28 : case CMD_UPDATE:
3396 28 : ereport(ERROR,
3397 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3398 : errmsg("cannot update column \"%s\" of view \"%s\"",
3399 : non_updatable_col,
3400 : RelationGetRelationName(view)),
3401 : errdetail_internal("%s", _(auto_update_detail))));
3402 : break;
3403 4 : case CMD_MERGE:
3404 4 : ereport(ERROR,
3405 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3406 : errmsg("cannot merge into column \"%s\" of view \"%s\"",
3407 : non_updatable_col,
3408 : RelationGetRelationName(view)),
3409 : errdetail_internal("%s", _(auto_update_detail))));
3410 : break;
3411 0 : default:
3412 0 : elog(ERROR, "unrecognized CmdType: %d",
3413 : (int) parsetree->commandType);
3414 : break;
3415 : }
3416 : }
3417 : }
3418 :
3419 : /*
3420 : * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
3421 : * updatable view. The caller already checked that there isn't a full set
3422 : * of INSTEAD OF triggers, so this is to guard against having a partial
3423 : * set (mixing auto-update and trigger-update actions in a single command
3424 : * isn't supported).
3425 : */
3426 2202 : if (parsetree->commandType == CMD_MERGE)
3427 : {
3428 1832 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3429 : {
3430 1392 : if (action->commandType != CMD_NOTHING &&
3431 696 : view_has_instead_trigger(view, action->commandType, NIL))
3432 4 : ereport(ERROR,
3433 : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3434 : errmsg("cannot merge into view \"%s\"",
3435 : RelationGetRelationName(view)),
3436 : errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions but not all."),
3437 : errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
3438 : }
3439 : }
3440 :
3441 : /*
3442 : * If we get here, view_query_is_auto_updatable() has verified that the
3443 : * view contains a single base relation.
3444 : */
3445 : Assert(list_length(viewquery->jointree->fromlist) == 1);
3446 2198 : rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
3447 :
3448 2198 : base_rt_index = rtr->rtindex;
3449 2198 : base_rte = rt_fetch(base_rt_index, viewquery->rtable);
3450 : Assert(base_rte->rtekind == RTE_RELATION);
3451 2198 : base_perminfo = getRTEPermissionInfo(viewquery->rteperminfos, base_rte);
3452 :
3453 : /*
3454 : * Up to now, the base relation hasn't been touched at all in our query.
3455 : * We need to acquire lock on it before we try to do anything with it.
3456 : * (The subsequent recursive call of RewriteQuery will suppose that we
3457 : * already have the right lock!) Since it will become the query target
3458 : * relation, RowExclusiveLock is always the right thing.
3459 : */
3460 2198 : base_rel = relation_open(base_rte->relid, RowExclusiveLock);
3461 :
3462 : /*
3463 : * While we have the relation open, update the RTE's relkind, just in case
3464 : * it changed since this view was made (cf. AcquireRewriteLocks).
3465 : */
3466 2198 : base_rte->relkind = base_rel->rd_rel->relkind;
3467 :
3468 : /*
3469 : * If the view query contains any sublink subqueries then we need to also
3470 : * acquire locks on any relations they refer to. We know that there won't
3471 : * be any subqueries in the range table or CTEs, so we can skip those, as
3472 : * in AcquireRewriteLocks.
3473 : */
3474 2198 : if (viewquery->hasSubLinks)
3475 : {
3476 : acquireLocksOnSubLinks_context context;
3477 :
3478 172 : context.for_execute = true;
3479 172 : query_tree_walker(viewquery, acquireLocksOnSubLinks, &context,
3480 : QTW_IGNORE_RC_SUBQUERIES);
3481 : }
3482 :
3483 : /*
3484 : * Create a new target RTE describing the base relation, and add it to the
3485 : * outer query's rangetable. (What's happening in the next few steps is
3486 : * very much like what the planner would do to "pull up" the view into the
3487 : * outer query. Perhaps someday we should refactor things enough so that
3488 : * we can share code with the planner.)
3489 : *
3490 : * Be sure to set rellockmode to the correct thing for the target table.
3491 : * Since we copied the whole viewquery above, we can just scribble on
3492 : * base_rte instead of copying it.
3493 : */
3494 2198 : new_rte = base_rte;
3495 2198 : new_rte->rellockmode = RowExclusiveLock;
3496 :
3497 2198 : parsetree->rtable = lappend(parsetree->rtable, new_rte);
3498 2198 : new_rt_index = list_length(parsetree->rtable);
3499 :
3500 : /*
3501 : * INSERTs never inherit. For UPDATE/DELETE/MERGE, we use the view
3502 : * query's inheritance flag for the base relation.
3503 : */
3504 2198 : if (parsetree->commandType == CMD_INSERT)
3505 792 : new_rte->inh = false;
3506 :
3507 : /*
3508 : * Adjust the view's targetlist Vars to reference the new target RTE, ie
3509 : * make their varnos be new_rt_index instead of base_rt_index. There can
3510 : * be no Vars for other rels in the tlist, so this is sufficient to pull
3511 : * up the tlist expressions for use in the outer query. The tlist will
3512 : * provide the replacement expressions used by ReplaceVarsFromTargetList
3513 : * below.
3514 : */
3515 2198 : view_targetlist = viewquery->targetList;
3516 :
3517 2198 : ChangeVarNodes((Node *) view_targetlist,
3518 : base_rt_index,
3519 : new_rt_index,
3520 : 0);
3521 :
3522 : /*
3523 : * If the view has "security_invoker" set, mark the new target relation
3524 : * for the permissions checks that we want to enforce against the query
3525 : * caller. Otherwise we want to enforce them against the view owner.
3526 : *
3527 : * At the relation level, require the same INSERT/UPDATE/DELETE
3528 : * permissions that the query caller needs against the view. We drop the
3529 : * ACL_SELECT bit that is presumably in new_perminfo->requiredPerms
3530 : * initially.
3531 : *
3532 : * Note: the original view's RTEPermissionInfo remains in the query's
3533 : * rteperminfos so that the executor still performs appropriate
3534 : * permissions checks for the query caller's use of the view.
3535 : *
3536 : * Disregard the perminfo in viewquery->rteperminfos that the base_rte
3537 : * would currently be pointing at, because we'd like it to point now to a
3538 : * new one that will be filled below. Must set perminfoindex to 0 to not
3539 : * trip over the Assert in addRTEPermissionInfo().
3540 : */
3541 2198 : new_rte->perminfoindex = 0;
3542 2198 : new_perminfo = addRTEPermissionInfo(&parsetree->rteperminfos, new_rte);
3543 2198 : if (RelationHasSecurityInvoker(view))
3544 324 : new_perminfo->checkAsUser = InvalidOid;
3545 : else
3546 1874 : new_perminfo->checkAsUser = view->rd_rel->relowner;
3547 2198 : new_perminfo->requiredPerms = view_perminfo->requiredPerms;
3548 :
3549 : /*
3550 : * Now for the per-column permissions bits.
3551 : *
3552 : * Initially, new_perminfo (base_perminfo) contains selectedCols
3553 : * permission check bits for all base-rel columns referenced by the view,
3554 : * but since the view is a SELECT query its insertedCols/updatedCols is
3555 : * empty. We set insertedCols and updatedCols to include all the columns
3556 : * the outer query is trying to modify, adjusting the column numbers as
3557 : * needed. But we leave selectedCols as-is, so the view owner must have
3558 : * read permission for all columns used in the view definition, even if
3559 : * some of them are not read by the outer query. We could try to limit
3560 : * selectedCols to only columns used in the transformed query, but that
3561 : * does not correspond to what happens in ordinary SELECT usage of a view:
3562 : * all referenced columns must have read permission, even if optimization
3563 : * finds that some of them can be discarded during query transformation.
3564 : * The flattening we're doing here is an optional optimization, too. (If
3565 : * you are unpersuaded and want to change this, note that applying
3566 : * adjust_view_column_set to view_perminfo->selectedCols is clearly *not*
3567 : * the right answer, since that neglects base-rel columns used in the
3568 : * view's WHERE quals.)
3569 : *
3570 : * This step needs the modified view targetlist, so we have to do things
3571 : * in this order.
3572 : */
3573 : Assert(bms_is_empty(new_perminfo->insertedCols) &&
3574 : bms_is_empty(new_perminfo->updatedCols));
3575 :
3576 2198 : new_perminfo->selectedCols = base_perminfo->selectedCols;
3577 :
3578 2198 : new_perminfo->insertedCols =
3579 2198 : adjust_view_column_set(view_perminfo->insertedCols, view_targetlist);
3580 :
3581 2198 : new_perminfo->updatedCols =
3582 2198 : adjust_view_column_set(view_perminfo->updatedCols, view_targetlist);
3583 :
3584 : /*
3585 : * Move any security barrier quals from the view RTE onto the new target
3586 : * RTE. Any such quals should now apply to the new target RTE and will
3587 : * not reference the original view RTE in the rewritten query.
3588 : */
3589 2198 : new_rte->securityQuals = view_rte->securityQuals;
3590 2198 : view_rte->securityQuals = NIL;
3591 :
3592 : /*
3593 : * Now update all Vars in the outer query that reference the view to
3594 : * reference the appropriate column of the base relation instead.
3595 : */
3596 : parsetree = (Query *)
3597 2198 : ReplaceVarsFromTargetList((Node *) parsetree,
3598 : parsetree->resultRelation,
3599 : 0,
3600 : view_rte,
3601 : view_targetlist,
3602 : new_rt_index,
3603 : REPLACEVARS_REPORT_ERROR,
3604 : 0,
3605 : NULL);
3606 :
3607 : /*
3608 : * Update all other RTI references in the query that point to the view
3609 : * (for example, parsetree->resultRelation itself) to point to the new
3610 : * base relation instead. Vars will not be affected since none of them
3611 : * reference parsetree->resultRelation any longer.
3612 : */
3613 2198 : ChangeVarNodes((Node *) parsetree,
3614 : parsetree->resultRelation,
3615 : new_rt_index,
3616 : 0);
3617 : Assert(parsetree->resultRelation == new_rt_index);
3618 :
3619 : /*
3620 : * For INSERT/UPDATE we must also update resnos in the targetlist to refer
3621 : * to columns of the base relation, since those indicate the target
3622 : * columns to be affected. Similarly, for MERGE we must update the resnos
3623 : * in the merge action targetlists of any INSERT/UPDATE actions.
3624 : *
3625 : * Note that this destroys the resno ordering of the targetlists, but that
3626 : * will be fixed when we recurse through RewriteQuery, which will invoke
3627 : * rewriteTargetListIU again on the updated targetlists.
3628 : */
3629 2198 : if (parsetree->commandType != CMD_DELETE)
3630 : {
3631 4122 : foreach(lc, parsetree->targetList)
3632 : {
3633 2124 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3634 : TargetEntry *view_tle;
3635 :
3636 2124 : if (tle->resjunk)
3637 0 : continue;
3638 :
3639 2124 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3640 2124 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3641 2124 : tle->resno = ((Var *) view_tle->expr)->varattno;
3642 : else
3643 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3644 : tle->resno);
3645 : }
3646 :
3647 4688 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3648 : {
3649 692 : if (action->commandType == CMD_INSERT ||
3650 560 : action->commandType == CMD_UPDATE)
3651 : {
3652 1904 : foreach_node(TargetEntry, tle, action->targetList)
3653 : {
3654 : TargetEntry *view_tle;
3655 :
3656 728 : if (tle->resjunk)
3657 0 : continue;
3658 :
3659 728 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3660 728 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3661 728 : tle->resno = ((Var *) view_tle->expr)->varattno;
3662 : else
3663 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3664 : tle->resno);
3665 : }
3666 : }
3667 : }
3668 : }
3669 :
3670 : /*
3671 : * For INSERT .. ON CONFLICT .. DO SELECT/UPDATE, we must also update
3672 : * assorted stuff in the onConflict data structure.
3673 : */
3674 2198 : if (parsetree->onConflict &&
3675 164 : (parsetree->onConflict->action == ONCONFLICT_UPDATE ||
3676 64 : parsetree->onConflict->action == ONCONFLICT_SELECT))
3677 : {
3678 : Index old_exclRelIndex,
3679 : new_exclRelIndex;
3680 : ParseNamespaceItem *new_exclNSItem;
3681 : RangeTblEntry *new_exclRte;
3682 : List *tmp_tlist;
3683 :
3684 : /*
3685 : * For ON CONFLICT DO UPDATE, update the resnos in the auxiliary
3686 : * UPDATE targetlist to refer to columns of the base relation.
3687 : */
3688 248 : foreach(lc, parsetree->onConflict->onConflictSet)
3689 : {
3690 100 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3691 : TargetEntry *view_tle;
3692 :
3693 100 : if (tle->resjunk)
3694 0 : continue;
3695 :
3696 100 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3697 100 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3698 100 : tle->resno = ((Var *) view_tle->expr)->varattno;
3699 : else
3700 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3701 : tle->resno);
3702 : }
3703 :
3704 : /*
3705 : * Create a new RTE for the EXCLUDED pseudo-relation, using the
3706 : * query's new base rel (which may well have a different column list
3707 : * from the view, hence we need a new column alias list). This should
3708 : * match transformOnConflictClause. In particular, note that the
3709 : * relkind is set to composite to signal that we're not dealing with
3710 : * an actual relation.
3711 : */
3712 148 : old_exclRelIndex = parsetree->onConflict->exclRelIndex;
3713 :
3714 148 : new_exclNSItem = addRangeTableEntryForRelation(make_parsestate(NULL),
3715 : base_rel,
3716 : RowExclusiveLock,
3717 : makeAlias("excluded", NIL),
3718 : false, false);
3719 148 : new_exclRte = new_exclNSItem->p_rte;
3720 148 : new_exclRte->relkind = RELKIND_COMPOSITE_TYPE;
3721 : /* Ignore the RTEPermissionInfo that would've been added. */
3722 148 : new_exclRte->perminfoindex = 0;
3723 :
3724 148 : parsetree->rtable = lappend(parsetree->rtable, new_exclRte);
3725 296 : new_exclRelIndex = parsetree->onConflict->exclRelIndex =
3726 148 : list_length(parsetree->rtable);
3727 :
3728 : /*
3729 : * Replace the targetlist for the EXCLUDED pseudo-relation with a new
3730 : * one, representing the columns from the new base relation.
3731 : */
3732 296 : parsetree->onConflict->exclRelTlist =
3733 148 : BuildOnConflictExcludedTargetlist(base_rel, new_exclRelIndex);
3734 :
3735 : /*
3736 : * Update all Vars in the ON CONFLICT clause that refer to the old
3737 : * EXCLUDED pseudo-relation. We want to use the column mappings
3738 : * defined in the view targetlist, but we need the outputs to refer to
3739 : * the new EXCLUDED pseudo-relation rather than the new target RTE.
3740 : * Also notice that "EXCLUDED.*" will be expanded using the view's
3741 : * rowtype, which seems correct.
3742 : */
3743 148 : tmp_tlist = copyObject(view_targetlist);
3744 :
3745 148 : ChangeVarNodes((Node *) tmp_tlist, new_rt_index,
3746 : new_exclRelIndex, 0);
3747 :
3748 148 : parsetree->onConflict = (OnConflictExpr *)
3749 148 : ReplaceVarsFromTargetList((Node *) parsetree->onConflict,
3750 : old_exclRelIndex,
3751 : 0,
3752 : view_rte,
3753 : tmp_tlist,
3754 : new_rt_index,
3755 : REPLACEVARS_REPORT_ERROR,
3756 : 0,
3757 : &parsetree->hasSubLinks);
3758 : }
3759 :
3760 : /*
3761 : * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view. We
3762 : * know that any Vars in the quals must reference the one base relation,
3763 : * so we need only adjust their varnos to reference the new target (just
3764 : * the same as we did with the view targetlist).
3765 : *
3766 : * If it's a security-barrier view, its WHERE quals must be applied before
3767 : * quals from the outer query, so we attach them to the RTE as security
3768 : * barrier quals rather than adding them to the main WHERE clause.
3769 : *
3770 : * For INSERT, the view's quals can be ignored in the main query.
3771 : */
3772 2198 : if (parsetree->commandType != CMD_INSERT &&
3773 1406 : viewquery->jointree->quals != NULL)
3774 : {
3775 502 : Node *viewqual = (Node *) viewquery->jointree->quals;
3776 :
3777 : /*
3778 : * Even though we copied viewquery already at the top of this
3779 : * function, we must duplicate the viewqual again here, because we may
3780 : * need to use the quals again below for a WithCheckOption clause.
3781 : */
3782 502 : viewqual = copyObject(viewqual);
3783 :
3784 502 : ChangeVarNodes(viewqual, base_rt_index, new_rt_index, 0);
3785 :
3786 502 : if (RelationIsSecurityView(view))
3787 : {
3788 : /*
3789 : * The view's quals go in front of existing barrier quals: those
3790 : * would have come from an outer level of security-barrier view,
3791 : * and so must get evaluated later.
3792 : *
3793 : * Note: the parsetree has been mutated, so the new_rte pointer is
3794 : * stale and needs to be re-computed.
3795 : */
3796 156 : new_rte = rt_fetch(new_rt_index, parsetree->rtable);
3797 156 : new_rte->securityQuals = lcons(viewqual, new_rte->securityQuals);
3798 :
3799 : /*
3800 : * Do not set parsetree->hasRowSecurity, because these aren't RLS
3801 : * conditions (they aren't affected by enabling/disabling RLS).
3802 : */
3803 :
3804 : /*
3805 : * Make sure that the query is marked correctly if the added qual
3806 : * has sublinks.
3807 : */
3808 156 : if (!parsetree->hasSubLinks)
3809 140 : parsetree->hasSubLinks = checkExprHasSubLink(viewqual);
3810 : }
3811 : else
3812 346 : AddQual(parsetree, viewqual);
3813 : }
3814 :
3815 : /*
3816 : * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
3817 : * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
3818 : * OPTION, add the quals from the view to the query's withCheckOptions
3819 : * list.
3820 : */
3821 2198 : if (insert_or_update)
3822 : {
3823 1942 : bool has_wco = RelationHasCheckOption(view);
3824 1942 : bool cascaded = RelationHasCascadedCheckOption(view);
3825 :
3826 : /*
3827 : * If the parent view has a cascaded check option, treat this view as
3828 : * if it also had a cascaded check option.
3829 : *
3830 : * New WithCheckOptions are added to the start of the list, so if
3831 : * there is a cascaded check option, it will be the first item in the
3832 : * list.
3833 : */
3834 1942 : if (parsetree->withCheckOptions != NIL)
3835 : {
3836 76 : WithCheckOption *parent_wco =
3837 76 : (WithCheckOption *) linitial(parsetree->withCheckOptions);
3838 :
3839 76 : if (parent_wco->cascaded)
3840 : {
3841 60 : has_wco = true;
3842 60 : cascaded = true;
3843 : }
3844 : }
3845 :
3846 : /*
3847 : * Add the new WithCheckOption to the start of the list, so that
3848 : * checks on inner views are run before checks on outer views, as
3849 : * required by the SQL standard.
3850 : *
3851 : * If the new check is CASCADED, we need to add it even if this view
3852 : * has no quals, since there may be quals on child views. A LOCAL
3853 : * check can be omitted if this view has no quals.
3854 : */
3855 1942 : if (has_wco && (cascaded || viewquery->jointree->quals != NULL))
3856 : {
3857 : WithCheckOption *wco;
3858 :
3859 430 : wco = makeNode(WithCheckOption);
3860 430 : wco->kind = WCO_VIEW_CHECK;
3861 430 : wco->relname = pstrdup(RelationGetRelationName(view));
3862 430 : wco->polname = NULL;
3863 430 : wco->qual = NULL;
3864 430 : wco->cascaded = cascaded;
3865 :
3866 430 : parsetree->withCheckOptions = lcons(wco,
3867 : parsetree->withCheckOptions);
3868 :
3869 430 : if (viewquery->jointree->quals != NULL)
3870 : {
3871 390 : wco->qual = (Node *) viewquery->jointree->quals;
3872 390 : ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
3873 :
3874 : /*
3875 : * For INSERT, make sure that the query is marked correctly if
3876 : * the added qual has sublinks. This can be skipped for
3877 : * UPDATE/MERGE, since the same qual will have already been
3878 : * added above, and the check will already have been done.
3879 : */
3880 390 : if (!parsetree->hasSubLinks &&
3881 326 : parsetree->commandType == CMD_INSERT)
3882 204 : parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
3883 : }
3884 : }
3885 : }
3886 :
3887 2198 : table_close(base_rel, NoLock);
3888 :
3889 2198 : return parsetree;
3890 : }
3891 :
3892 :
3893 : /*
3894 : * RewriteQuery -
3895 : * rewrites the query and apply the rules again on the queries rewritten
3896 : *
3897 : * rewrite_events is a list of open query-rewrite actions, so we can detect
3898 : * infinite recursion.
3899 : *
3900 : * orig_rt_length is the length of the originating query's rtable, for product
3901 : * queries created by fireRules(), and 0 otherwise. This is used to skip any
3902 : * already-processed VALUES RTEs from the original query.
3903 : *
3904 : * num_ctes_processed is the number of CTEs at the end of the query's cteList
3905 : * that have already been rewritten, and must not be rewritten again.
3906 : */
3907 : static List *
3908 287805 : RewriteQuery(Query *parsetree, List *rewrite_events, int orig_rt_length,
3909 : int num_ctes_processed)
3910 : {
3911 287805 : CmdType event = parsetree->commandType;
3912 287805 : bool instead = false;
3913 287805 : bool returning = false;
3914 287805 : bool updatableview = false;
3915 287805 : Query *qual_product = NULL;
3916 287805 : List *rewritten = NIL;
3917 : ListCell *lc1;
3918 :
3919 : /*
3920 : * First, recursively process any insert/update/delete/merge statements in
3921 : * WITH clauses. (We have to do this first because the WITH clauses may
3922 : * get copied into rule actions below.)
3923 : *
3924 : * Any new WITH clauses from rule actions are processed when we recurse
3925 : * into product queries below. However, when recursing, we must take care
3926 : * to avoid rewriting a CTE query more than once (because expanding
3927 : * generated columns in the targetlist more than once would fail). Since
3928 : * new CTEs from product queries are added to the start of the list (see
3929 : * rewriteRuleAction), we just skip the last num_ctes_processed items.
3930 : */
3931 290108 : foreach(lc1, parsetree->cteList)
3932 : {
3933 2351 : CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc1);
3934 2351 : Query *ctequery = castNode(Query, cte->ctequery);
3935 2351 : int i = foreach_current_index(lc1);
3936 : List *newstuff;
3937 :
3938 : /* Skip already-processed CTEs at the end of the list */
3939 2351 : if (i >= list_length(parsetree->cteList) - num_ctes_processed)
3940 28 : break;
3941 :
3942 2323 : if (ctequery->commandType == CMD_SELECT)
3943 2081 : continue;
3944 :
3945 242 : newstuff = RewriteQuery(ctequery, rewrite_events, 0, 0);
3946 :
3947 : /*
3948 : * Currently we can only handle unconditional, single-statement DO
3949 : * INSTEAD rules correctly; we have to get exactly one non-utility
3950 : * Query out of the rewrite operation to stuff back into the CTE node.
3951 : */
3952 242 : if (list_length(newstuff) == 1)
3953 : {
3954 : /* Must check it's not a utility command */
3955 226 : ctequery = linitial_node(Query, newstuff);
3956 226 : if (!(ctequery->commandType == CMD_SELECT ||
3957 226 : ctequery->commandType == CMD_UPDATE ||
3958 169 : ctequery->commandType == CMD_INSERT ||
3959 54 : ctequery->commandType == CMD_DELETE ||
3960 22 : ctequery->commandType == CMD_MERGE))
3961 : {
3962 : /*
3963 : * Currently it could only be NOTIFY; this error message will
3964 : * need work if we ever allow other utility commands in rules.
3965 : */
3966 4 : ereport(ERROR,
3967 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3968 : errmsg("DO INSTEAD NOTIFY rules are not supported for data-modifying statements in WITH")));
3969 : }
3970 : /* WITH queries should never be canSetTag */
3971 : Assert(!ctequery->canSetTag);
3972 : /* Push the single Query back into the CTE node */
3973 222 : cte->ctequery = (Node *) ctequery;
3974 : }
3975 16 : else if (newstuff == NIL)
3976 : {
3977 4 : ereport(ERROR,
3978 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3979 : errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
3980 : }
3981 : else
3982 : {
3983 : ListCell *lc2;
3984 :
3985 : /* examine queries to determine which error message to issue */
3986 28 : foreach(lc2, newstuff)
3987 : {
3988 24 : Query *q = (Query *) lfirst(lc2);
3989 :
3990 24 : if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
3991 4 : ereport(ERROR,
3992 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3993 : errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in WITH")));
3994 20 : if (q->querySource == QSRC_NON_INSTEAD_RULE)
3995 4 : ereport(ERROR,
3996 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3997 : errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
3998 : }
3999 :
4000 4 : ereport(ERROR,
4001 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4002 : errmsg("multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
4003 : }
4004 : }
4005 287785 : num_ctes_processed = list_length(parsetree->cteList);
4006 :
4007 : /*
4008 : * If the statement is an insert, update, delete, or merge, adjust its
4009 : * targetlist as needed, and then fire INSERT/UPDATE/DELETE rules on it.
4010 : *
4011 : * SELECT rules are handled later when we have all the queries that should
4012 : * get executed. Also, utilities aren't rewritten at all (do we still
4013 : * need that check?)
4014 : */
4015 287785 : if (event != CMD_SELECT && event != CMD_UTILITY)
4016 : {
4017 : int result_relation;
4018 : RangeTblEntry *rt_entry;
4019 : Relation rt_entry_relation;
4020 : List *locks;
4021 : int product_orig_rt_length;
4022 : List *product_queries;
4023 58314 : bool hasUpdate = false;
4024 58314 : int values_rte_index = 0;
4025 58314 : bool defaults_remaining = false;
4026 :
4027 58314 : result_relation = parsetree->resultRelation;
4028 : Assert(result_relation != 0);
4029 58314 : rt_entry = rt_fetch(result_relation, parsetree->rtable);
4030 : Assert(rt_entry->rtekind == RTE_RELATION);
4031 :
4032 : /*
4033 : * We can use NoLock here since either the parser or
4034 : * AcquireRewriteLocks should have locked the rel already.
4035 : */
4036 58314 : rt_entry_relation = relation_open(rt_entry->relid, NoLock);
4037 :
4038 : /*
4039 : * Rewrite the targetlist as needed for the command type.
4040 : */
4041 58314 : if (event == CMD_INSERT)
4042 : {
4043 : ListCell *lc2;
4044 44193 : RangeTblEntry *values_rte = NULL;
4045 :
4046 : /*
4047 : * Test if it's a multi-row INSERT ... VALUES (...), (...), ... by
4048 : * looking for a VALUES RTE in the fromlist. For product queries,
4049 : * we must ignore any already-processed VALUES RTEs from the
4050 : * original query. These appear at the start of the rangetable.
4051 : */
4052 51993 : foreach(lc2, parsetree->jointree->fromlist)
4053 : {
4054 7800 : RangeTblRef *rtr = (RangeTblRef *) lfirst(lc2);
4055 :
4056 7800 : if (IsA(rtr, RangeTblRef) && rtr->rtindex > orig_rt_length)
4057 : {
4058 7584 : RangeTblEntry *rte = rt_fetch(rtr->rtindex,
4059 : parsetree->rtable);
4060 :
4061 7584 : if (rte->rtekind == RTE_VALUES)
4062 : {
4063 : /* should not find more than one VALUES RTE */
4064 3291 : if (values_rte != NULL)
4065 0 : elog(ERROR, "more than one VALUES RTE found");
4066 :
4067 3291 : values_rte = rte;
4068 3291 : values_rte_index = rtr->rtindex;
4069 : }
4070 : }
4071 : }
4072 :
4073 44193 : if (values_rte)
4074 : {
4075 3291 : Bitmapset *unused_values_attrnos = NULL;
4076 :
4077 : /* Process the main targetlist ... */
4078 3291 : parsetree->targetList = rewriteTargetListIU(parsetree->targetList,
4079 : parsetree->commandType,
4080 : parsetree->override,
4081 : rt_entry_relation,
4082 : values_rte,
4083 : values_rte_index,
4084 : &unused_values_attrnos);
4085 : /* ... and the VALUES expression lists */
4086 3223 : if (!rewriteValuesRTE(parsetree, values_rte, values_rte_index,
4087 : rt_entry_relation,
4088 : unused_values_attrnos))
4089 52 : defaults_remaining = true;
4090 : }
4091 : else
4092 : {
4093 : /* Process just the main targetlist */
4094 40850 : parsetree->targetList =
4095 40902 : rewriteTargetListIU(parsetree->targetList,
4096 : parsetree->commandType,
4097 : parsetree->override,
4098 : rt_entry_relation,
4099 : NULL, 0, NULL);
4100 : }
4101 :
4102 44073 : if (parsetree->onConflict &&
4103 1688 : parsetree->onConflict->action == ONCONFLICT_UPDATE)
4104 : {
4105 1002 : parsetree->onConflict->onConflictSet =
4106 1002 : rewriteTargetListIU(parsetree->onConflict->onConflictSet,
4107 : CMD_UPDATE,
4108 : parsetree->override,
4109 : rt_entry_relation,
4110 : NULL, 0, NULL);
4111 : }
4112 : }
4113 14121 : else if (event == CMD_UPDATE)
4114 : {
4115 : Assert(parsetree->override == OVERRIDING_NOT_SET);
4116 9174 : parsetree->targetList =
4117 9194 : rewriteTargetListIU(parsetree->targetList,
4118 : parsetree->commandType,
4119 : parsetree->override,
4120 : rt_entry_relation,
4121 : NULL, 0, NULL);
4122 : }
4123 4927 : else if (event == CMD_MERGE)
4124 : {
4125 : Assert(parsetree->override == OVERRIDING_NOT_SET);
4126 :
4127 : /*
4128 : * Rewrite each action targetlist separately
4129 : */
4130 4621 : foreach(lc1, parsetree->mergeActionList)
4131 : {
4132 2727 : MergeAction *action = (MergeAction *) lfirst(lc1);
4133 :
4134 2727 : switch (action->commandType)
4135 : {
4136 497 : case CMD_NOTHING:
4137 : case CMD_DELETE: /* Nothing to do here */
4138 497 : break;
4139 2230 : case CMD_UPDATE:
4140 : case CMD_INSERT:
4141 :
4142 : /*
4143 : * MERGE actions do not permit multi-row INSERTs, so
4144 : * there is no VALUES RTE to deal with here.
4145 : */
4146 2226 : action->targetList =
4147 2230 : rewriteTargetListIU(action->targetList,
4148 : action->commandType,
4149 : action->override,
4150 : rt_entry_relation,
4151 : NULL, 0, NULL);
4152 2226 : break;
4153 0 : default:
4154 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
4155 : break;
4156 : }
4157 : }
4158 : }
4159 3029 : else if (event == CMD_DELETE)
4160 : {
4161 : /* Nothing to do here */
4162 : }
4163 : else
4164 0 : elog(ERROR, "unrecognized commandType: %d", (int) event);
4165 :
4166 : /*
4167 : * Collect and apply the appropriate rules.
4168 : */
4169 58170 : locks = matchLocks(event, rt_entry_relation,
4170 : result_relation, parsetree, &hasUpdate);
4171 :
4172 58158 : product_orig_rt_length = list_length(parsetree->rtable);
4173 58158 : product_queries = fireRules(parsetree,
4174 : result_relation,
4175 : event,
4176 : locks,
4177 : &instead,
4178 : &returning,
4179 : &qual_product);
4180 :
4181 : /*
4182 : * If we have a VALUES RTE with any remaining untouched DEFAULT items,
4183 : * and we got any product queries, finalize the VALUES RTE for each
4184 : * product query (replacing the remaining DEFAULT items with NULLs).
4185 : * We don't do this for the original query, because we know that it
4186 : * must be an auto-insert on a view, and so should use the base
4187 : * relation's defaults for any remaining DEFAULT items.
4188 : */
4189 58150 : if (defaults_remaining && product_queries != NIL)
4190 : {
4191 : ListCell *n;
4192 :
4193 : /*
4194 : * Each product query has its own copy of the VALUES RTE at the
4195 : * same index in the rangetable, so we must finalize each one.
4196 : *
4197 : * Note that if the product query is an INSERT ... SELECT, then
4198 : * the VALUES RTE will be at the same index in the SELECT part of
4199 : * the product query rather than the top-level product query
4200 : * itself.
4201 : */
4202 32 : foreach(n, product_queries)
4203 : {
4204 16 : Query *pt = (Query *) lfirst(n);
4205 : RangeTblEntry *values_rte;
4206 :
4207 16 : if (pt->commandType == CMD_INSERT &&
4208 32 : pt->jointree && IsA(pt->jointree, FromExpr) &&
4209 16 : list_length(pt->jointree->fromlist) == 1)
4210 : {
4211 16 : Node *jtnode = (Node *) linitial(pt->jointree->fromlist);
4212 :
4213 16 : if (IsA(jtnode, RangeTblRef))
4214 : {
4215 16 : int rtindex = ((RangeTblRef *) jtnode)->rtindex;
4216 16 : RangeTblEntry *src_rte = rt_fetch(rtindex, pt->rtable);
4217 :
4218 16 : if (src_rte->rtekind == RTE_SUBQUERY &&
4219 4 : src_rte->subquery &&
4220 4 : IsA(src_rte->subquery, Query) &&
4221 4 : src_rte->subquery->commandType == CMD_SELECT)
4222 4 : pt = src_rte->subquery;
4223 : }
4224 : }
4225 :
4226 16 : values_rte = rt_fetch(values_rte_index, pt->rtable);
4227 16 : if (values_rte->rtekind != RTE_VALUES)
4228 0 : elog(ERROR, "failed to find VALUES RTE in product query");
4229 :
4230 16 : rewriteValuesRTEToNulls(pt, values_rte);
4231 : }
4232 : }
4233 :
4234 : /*
4235 : * If there was no unqualified INSTEAD rule, and the target relation
4236 : * is a view without any INSTEAD OF triggers, see if the view can be
4237 : * automatically updated. If so, we perform the necessary query
4238 : * transformation here and add the resulting query to the
4239 : * product_queries list, so that it gets recursively rewritten if
4240 : * necessary. For MERGE, the view must be automatically updatable if
4241 : * any of the merge actions lack a corresponding INSTEAD OF trigger.
4242 : *
4243 : * If the view cannot be automatically updated, we throw an error here
4244 : * which is OK since the query would fail at runtime anyway. Throwing
4245 : * the error here is preferable to the executor check since we have
4246 : * more detailed information available about why the view isn't
4247 : * updatable.
4248 : */
4249 58150 : if (!instead &&
4250 57670 : rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
4251 2659 : !view_has_instead_trigger(rt_entry_relation, event,
4252 : parsetree->mergeActionList))
4253 : {
4254 : /*
4255 : * If there were any qualified INSTEAD rules, don't allow the view
4256 : * to be automatically updated (an unqualified INSTEAD rule or
4257 : * INSTEAD OF trigger is required).
4258 : */
4259 2390 : if (qual_product != NULL)
4260 12 : error_view_not_updatable(rt_entry_relation,
4261 : parsetree->commandType,
4262 : parsetree->mergeActionList,
4263 : gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
4264 :
4265 : /*
4266 : * Attempt to rewrite the query to automatically update the view.
4267 : * This throws an error if the view can't be automatically
4268 : * updated.
4269 : */
4270 2378 : parsetree = rewriteTargetView(parsetree, rt_entry_relation);
4271 :
4272 : /*
4273 : * At this point product_queries contains any DO ALSO rule
4274 : * actions. Add the rewritten query before or after those. This
4275 : * must match the handling the original query would have gotten
4276 : * below, if we allowed it to be included again.
4277 : */
4278 2198 : if (parsetree->commandType == CMD_INSERT)
4279 792 : product_queries = lcons(parsetree, product_queries);
4280 : else
4281 1406 : product_queries = lappend(product_queries, parsetree);
4282 :
4283 : /*
4284 : * Set the "instead" flag, as if there had been an unqualified
4285 : * INSTEAD, to prevent the original query from being included a
4286 : * second time below. The transformation will have rewritten any
4287 : * RETURNING list, so we can also set "returning" to forestall
4288 : * throwing an error below.
4289 : */
4290 2198 : instead = true;
4291 2198 : returning = true;
4292 2198 : updatableview = true;
4293 : }
4294 :
4295 : /*
4296 : * If we got any product queries, recursively rewrite them --- but
4297 : * first check for recursion!
4298 : */
4299 57958 : if (product_queries != NIL)
4300 : {
4301 : ListCell *n;
4302 : rewrite_event *rev;
4303 :
4304 3610 : foreach(n, rewrite_events)
4305 : {
4306 644 : rev = (rewrite_event *) lfirst(n);
4307 644 : if (rev->relation == RelationGetRelid(rt_entry_relation) &&
4308 0 : rev->event == event)
4309 0 : ereport(ERROR,
4310 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
4311 : errmsg("infinite recursion detected in rules for relation \"%s\"",
4312 : RelationGetRelationName(rt_entry_relation))));
4313 : }
4314 :
4315 2966 : rev = palloc_object(rewrite_event);
4316 2966 : rev->relation = RelationGetRelid(rt_entry_relation);
4317 2966 : rev->event = event;
4318 2966 : rewrite_events = lappend(rewrite_events, rev);
4319 :
4320 5992 : foreach(n, product_queries)
4321 : {
4322 3122 : Query *pt = (Query *) lfirst(n);
4323 : List *newstuff;
4324 :
4325 : /*
4326 : * For an updatable view, pt might be the rewritten version of
4327 : * the original query, in which case we pass on orig_rt_length
4328 : * to finish processing any VALUES RTE it contained.
4329 : *
4330 : * Otherwise, we have a product query created by fireRules().
4331 : * Any VALUES RTEs from the original query have been fully
4332 : * processed, and must be skipped when we recurse.
4333 : */
4334 3122 : newstuff = RewriteQuery(pt, rewrite_events,
4335 : pt == parsetree ?
4336 : orig_rt_length :
4337 : product_orig_rt_length,
4338 : num_ctes_processed);
4339 3026 : rewritten = list_concat(rewritten, newstuff);
4340 : }
4341 :
4342 2870 : rewrite_events = list_delete_last(rewrite_events);
4343 : }
4344 :
4345 : /*
4346 : * If there is an INSTEAD, and the original query has a RETURNING, we
4347 : * have to have found a RETURNING in the rule(s), else fail. (Because
4348 : * DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
4349 : * rules, there's no need to worry whether the substituted RETURNING
4350 : * will actually be executed --- it must be.)
4351 : */
4352 57862 : if ((instead || qual_product != NULL) &&
4353 2790 : parsetree->returningList &&
4354 324 : !returning)
4355 : {
4356 4 : switch (event)
4357 : {
4358 4 : case CMD_INSERT:
4359 4 : ereport(ERROR,
4360 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4361 : errmsg("cannot perform INSERT RETURNING on relation \"%s\"",
4362 : RelationGetRelationName(rt_entry_relation)),
4363 : errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.")));
4364 : break;
4365 0 : case CMD_UPDATE:
4366 0 : ereport(ERROR,
4367 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4368 : errmsg("cannot perform UPDATE RETURNING on relation \"%s\"",
4369 : RelationGetRelationName(rt_entry_relation)),
4370 : errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause.")));
4371 : break;
4372 0 : case CMD_DELETE:
4373 0 : ereport(ERROR,
4374 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4375 : errmsg("cannot perform DELETE RETURNING on relation \"%s\"",
4376 : RelationGetRelationName(rt_entry_relation)),
4377 : errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause.")));
4378 : break;
4379 0 : default:
4380 0 : elog(ERROR, "unrecognized commandType: %d",
4381 : (int) event);
4382 : break;
4383 : }
4384 : }
4385 :
4386 : /*
4387 : * Updatable views are supported by ON CONFLICT, so don't prevent that
4388 : * case from proceeding
4389 : */
4390 57858 : if (parsetree->onConflict &&
4391 1508 : (product_queries != NIL || hasUpdate) &&
4392 172 : !updatableview)
4393 8 : ereport(ERROR,
4394 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4395 : errmsg("INSERT with ON CONFLICT clause cannot be used with table that has INSERT or UPDATE rules")));
4396 :
4397 57850 : table_close(rt_entry_relation, NoLock);
4398 : }
4399 :
4400 : /*
4401 : * For INSERTs, the original query is done first; for UPDATE/DELETE, it is
4402 : * done last. This is needed because update and delete rule actions might
4403 : * not do anything if they are invoked after the update or delete is
4404 : * performed. The command counter increment between the query executions
4405 : * makes the deleted (and maybe the updated) tuples disappear so the scans
4406 : * for them in the rule actions cannot find them.
4407 : *
4408 : * If we found any unqualified INSTEAD, the original query is not done at
4409 : * all, in any form. Otherwise, we add the modified form if qualified
4410 : * INSTEADs were found, else the unmodified form.
4411 : */
4412 287321 : if (!instead)
4413 : {
4414 284751 : if (parsetree->commandType == CMD_INSERT)
4415 : {
4416 42933 : if (qual_product != NULL)
4417 196 : rewritten = lcons(qual_product, rewritten);
4418 : else
4419 42737 : rewritten = lcons(parsetree, rewritten);
4420 : }
4421 : else
4422 : {
4423 241818 : if (qual_product != NULL)
4424 12 : rewritten = lappend(rewritten, qual_product);
4425 : else
4426 241806 : rewritten = lappend(rewritten, parsetree);
4427 : }
4428 : }
4429 :
4430 : /*
4431 : * If the original query has a CTE list, and we generated more than one
4432 : * non-utility result query, we have to fail because we'll have copied the
4433 : * CTE list into each result query. That would break the expectation of
4434 : * single evaluation of CTEs. This could possibly be fixed by
4435 : * restructuring so that a CTE list can be shared across multiple Query
4436 : * and PlannableStatement nodes.
4437 : */
4438 287321 : if (parsetree->cteList != NIL)
4439 : {
4440 1647 : int qcount = 0;
4441 :
4442 3294 : foreach(lc1, rewritten)
4443 : {
4444 1647 : Query *q = (Query *) lfirst(lc1);
4445 :
4446 1647 : if (q->commandType != CMD_UTILITY)
4447 1647 : qcount++;
4448 : }
4449 1647 : if (qcount > 1)
4450 0 : ereport(ERROR,
4451 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4452 : errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries")));
4453 : }
4454 :
4455 287321 : return rewritten;
4456 : }
4457 :
4458 :
4459 : /*
4460 : * Expand virtual generated columns
4461 : *
4462 : * If the table contains virtual generated columns, build a target list
4463 : * containing the expanded expressions and use ReplaceVarsFromTargetList() to
4464 : * do the replacements.
4465 : *
4466 : * Vars matching rt_index at the current query level are replaced by the
4467 : * virtual generated column expressions from rel, if there are any.
4468 : *
4469 : * The caller must also provide rte, the RTE describing the target relation,
4470 : * in order to handle any whole-row Vars referencing the target, and
4471 : * result_relation, the index of the result relation, if this is part of an
4472 : * INSERT/UPDATE/DELETE/MERGE query.
4473 : */
4474 : static Node *
4475 307 : expand_generated_columns_internal(Node *node, Relation rel, int rt_index,
4476 : RangeTblEntry *rte, int result_relation)
4477 : {
4478 : TupleDesc tupdesc;
4479 :
4480 307 : tupdesc = RelationGetDescr(rel);
4481 307 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
4482 : {
4483 307 : List *tlist = NIL;
4484 :
4485 1072 : for (int i = 0; i < tupdesc->natts; i++)
4486 : {
4487 765 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
4488 :
4489 765 : if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
4490 : {
4491 : Node *defexpr;
4492 : TargetEntry *te;
4493 :
4494 319 : defexpr = build_generation_expression(rel, i + 1);
4495 319 : ChangeVarNodes(defexpr, 1, rt_index, 0);
4496 :
4497 319 : te = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
4498 319 : tlist = lappend(tlist, te);
4499 : }
4500 : }
4501 :
4502 : Assert(list_length(tlist) > 0);
4503 :
4504 307 : node = ReplaceVarsFromTargetList(node, rt_index, 0, rte, tlist,
4505 : result_relation,
4506 : REPLACEVARS_CHANGE_VARNO, rt_index,
4507 : NULL);
4508 : }
4509 :
4510 307 : return node;
4511 : }
4512 :
4513 : /*
4514 : * Expand virtual generated columns in an expression
4515 : *
4516 : * This is for expressions that are not part of a query, such as default
4517 : * expressions or index predicates. The rt_index is usually 1.
4518 : */
4519 : Node *
4520 9669 : expand_generated_columns_in_expr(Node *node, Relation rel, int rt_index)
4521 : {
4522 9669 : TupleDesc tupdesc = RelationGetDescr(rel);
4523 :
4524 9669 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
4525 : {
4526 : RangeTblEntry *rte;
4527 :
4528 307 : rte = makeNode(RangeTblEntry);
4529 : /* eref needs to be set, but the actual name doesn't matter */
4530 307 : rte->eref = makeAlias(RelationGetRelationName(rel), NIL);
4531 307 : rte->rtekind = RTE_RELATION;
4532 307 : rte->relid = RelationGetRelid(rel);
4533 :
4534 307 : node = expand_generated_columns_internal(node, rel, rt_index, rte, 0);
4535 : }
4536 :
4537 9669 : return node;
4538 : }
4539 :
4540 : /*
4541 : * Build the generation expression for the virtual generated column.
4542 : *
4543 : * Error out if there is no generation expression found for the given column.
4544 : */
4545 : Node *
4546 1597 : build_generation_expression(Relation rel, int attrno)
4547 : {
4548 1597 : TupleDesc rd_att = RelationGetDescr(rel);
4549 1597 : Form_pg_attribute att_tup = TupleDescAttr(rd_att, attrno - 1);
4550 : Node *defexpr;
4551 : Oid attcollid;
4552 :
4553 : Assert(rd_att->constr && rd_att->constr->has_generated_virtual);
4554 : Assert(att_tup->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL);
4555 :
4556 1597 : defexpr = build_column_default(rel, attrno);
4557 1597 : if (defexpr == NULL)
4558 0 : elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
4559 : attrno, RelationGetRelationName(rel));
4560 :
4561 : /*
4562 : * If the column definition has a collation and it is different from the
4563 : * collation of the generation expression, put a COLLATE clause around the
4564 : * expression.
4565 : */
4566 1597 : attcollid = att_tup->attcollation;
4567 1597 : if (attcollid && attcollid != exprCollation(defexpr))
4568 : {
4569 10 : CollateExpr *ce = makeNode(CollateExpr);
4570 :
4571 10 : ce->arg = (Expr *) defexpr;
4572 10 : ce->collOid = attcollid;
4573 10 : ce->location = -1;
4574 :
4575 10 : defexpr = (Node *) ce;
4576 : }
4577 :
4578 1597 : return defexpr;
4579 : }
4580 :
4581 :
4582 : /*
4583 : * QueryRewrite -
4584 : * Primary entry point to the query rewriter.
4585 : * Rewrite one query via query rewrite system, possibly returning 0
4586 : * or many queries.
4587 : *
4588 : * NOTE: the parsetree must either have come straight from the parser,
4589 : * or have been scanned by AcquireRewriteLocks to acquire suitable locks.
4590 : */
4591 : List *
4592 284441 : QueryRewrite(Query *parsetree)
4593 : {
4594 284441 : int64 input_query_id = parsetree->queryId;
4595 : List *querylist;
4596 : List *results;
4597 : ListCell *l;
4598 : CmdType origCmdType;
4599 : bool foundOriginalQuery;
4600 : Query *lastInstead;
4601 :
4602 : /*
4603 : * This function is only applied to top-level original queries
4604 : */
4605 : Assert(parsetree->querySource == QSRC_ORIGINAL);
4606 : Assert(parsetree->canSetTag);
4607 :
4608 : /*
4609 : * Step 1
4610 : *
4611 : * Apply all non-SELECT rules possibly getting 0 or many queries
4612 : */
4613 284441 : querylist = RewriteQuery(parsetree, NIL, 0, 0);
4614 :
4615 : /*
4616 : * Step 2
4617 : *
4618 : * Apply all the RIR rules on each query
4619 : *
4620 : * This is also a handy place to mark each query with the original queryId
4621 : */
4622 284053 : results = NIL;
4623 568406 : foreach(l, querylist)
4624 : {
4625 284489 : Query *query = (Query *) lfirst(l);
4626 :
4627 284489 : query = fireRIRrules(query, NIL);
4628 :
4629 284353 : query->queryId = input_query_id;
4630 :
4631 284353 : results = lappend(results, query);
4632 : }
4633 :
4634 : /*
4635 : * Step 3
4636 : *
4637 : * Determine which, if any, of the resulting queries is supposed to set
4638 : * the command-result tag; and update the canSetTag fields accordingly.
4639 : *
4640 : * If the original query is still in the list, it sets the command tag.
4641 : * Otherwise, the last INSTEAD query of the same kind as the original is
4642 : * allowed to set the tag. (Note these rules can leave us with no query
4643 : * setting the tag. The tcop code has to cope with this by setting up a
4644 : * default tag based on the original un-rewritten query.)
4645 : *
4646 : * The Asserts verify that at most one query in the result list is marked
4647 : * canSetTag. If we aren't checking asserts, we can fall out of the loop
4648 : * as soon as we find the original query.
4649 : */
4650 283917 : origCmdType = parsetree->commandType;
4651 283917 : foundOriginalQuery = false;
4652 283917 : lastInstead = NULL;
4653 :
4654 284497 : foreach(l, results)
4655 : {
4656 284049 : Query *query = (Query *) lfirst(l);
4657 :
4658 284049 : if (query->querySource == QSRC_ORIGINAL)
4659 : {
4660 : Assert(query->canSetTag);
4661 : Assert(!foundOriginalQuery);
4662 283469 : foundOriginalQuery = true;
4663 : #ifndef USE_ASSERT_CHECKING
4664 283469 : break;
4665 : #endif
4666 : }
4667 : else
4668 : {
4669 : Assert(!query->canSetTag);
4670 580 : if (query->commandType == origCmdType &&
4671 436 : (query->querySource == QSRC_INSTEAD_RULE ||
4672 72 : query->querySource == QSRC_QUAL_INSTEAD_RULE))
4673 396 : lastInstead = query;
4674 : }
4675 : }
4676 :
4677 283917 : if (!foundOriginalQuery && lastInstead != NULL)
4678 380 : lastInstead->canSetTag = true;
4679 :
4680 283917 : return results;
4681 : }
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