Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * rewriteHandler.c
4 : * Primary module of query rewriter.
5 : *
6 : * Portions Copyright (c) 1996-2024, 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/rewriteHandler.h"
40 : #include "rewrite/rewriteManip.h"
41 : #include "rewrite/rewriteSearchCycle.h"
42 : #include "rewrite/rowsecurity.h"
43 : #include "tcop/tcopprot.h"
44 : #include "utils/builtins.h"
45 : #include "utils/lsyscache.h"
46 : #include "utils/rel.h"
47 :
48 :
49 : /* We use a list of these to detect recursion in RewriteQuery */
50 : typedef struct rewrite_event
51 : {
52 : Oid relation; /* OID of relation having rules */
53 : CmdType event; /* type of rule being fired */
54 : } rewrite_event;
55 :
56 : typedef struct acquireLocksOnSubLinks_context
57 : {
58 : bool for_execute; /* AcquireRewriteLocks' forExecute param */
59 : } acquireLocksOnSubLinks_context;
60 :
61 : typedef struct fireRIRonSubLink_context
62 : {
63 : List *activeRIRs;
64 : bool hasRowSecurity;
65 : } fireRIRonSubLink_context;
66 :
67 : static bool acquireLocksOnSubLinks(Node *node,
68 : acquireLocksOnSubLinks_context *context);
69 : static Query *rewriteRuleAction(Query *parsetree,
70 : Query *rule_action,
71 : Node *rule_qual,
72 : int rt_index,
73 : CmdType event,
74 : bool *returning_flag);
75 : static List *adjustJoinTreeList(Query *parsetree, bool removert, int rt_index);
76 : static List *rewriteTargetListIU(List *targetList,
77 : CmdType commandType,
78 : OverridingKind override,
79 : Relation target_relation,
80 : RangeTblEntry *values_rte,
81 : int values_rte_index,
82 : Bitmapset **unused_values_attrnos);
83 : static TargetEntry *process_matched_tle(TargetEntry *src_tle,
84 : TargetEntry *prior_tle,
85 : const char *attrName);
86 : static Node *get_assignment_input(Node *node);
87 : static Bitmapset *findDefaultOnlyColumns(RangeTblEntry *rte);
88 : static bool rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
89 : Relation target_relation,
90 : Bitmapset *unused_cols);
91 : static void rewriteValuesRTEToNulls(Query *parsetree, RangeTblEntry *rte);
92 : static void markQueryForLocking(Query *qry, Node *jtnode,
93 : LockClauseStrength strength, LockWaitPolicy waitPolicy,
94 : bool pushedDown);
95 : static List *matchLocks(CmdType event, Relation relation,
96 : int varno, Query *parsetree, bool *hasUpdate);
97 : static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
98 : static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
99 :
100 :
101 : /*
102 : * AcquireRewriteLocks -
103 : * Acquire suitable locks on all the relations mentioned in the Query.
104 : * These locks will ensure that the relation schemas don't change under us
105 : * while we are rewriting, planning, and executing the query.
106 : *
107 : * Caution: this may modify the querytree, therefore caller should usually
108 : * have done a copyObject() to make a writable copy of the querytree in the
109 : * current memory context.
110 : *
111 : * forExecute indicates that the query is about to be executed. If so,
112 : * we'll acquire the lock modes specified in the RTE rellockmode fields.
113 : * If forExecute is false, AccessShareLock is acquired on all relations.
114 : * This case is suitable for ruleutils.c, for example, where we only need
115 : * schema stability and we don't intend to actually modify any relations.
116 : *
117 : * forUpdatePushedDown indicates that a pushed-down FOR [KEY] UPDATE/SHARE
118 : * applies to the current subquery, requiring all rels to be opened with at
119 : * least RowShareLock. This should always be false at the top of the
120 : * recursion. When it is true, we adjust RTE rellockmode fields to reflect
121 : * the higher lock level. This flag is ignored if forExecute is false.
122 : *
123 : * A secondary purpose of this routine is to fix up JOIN RTE references to
124 : * dropped columns (see details below). Such RTEs are modified in-place.
125 : *
126 : * This processing can, and for efficiency's sake should, be skipped when the
127 : * querytree has just been built by the parser: parse analysis already got
128 : * all the same locks we'd get here, and the parser will have omitted dropped
129 : * columns from JOINs to begin with. But we must do this whenever we are
130 : * dealing with a querytree produced earlier than the current command.
131 : *
132 : * About JOINs and dropped columns: although the parser never includes an
133 : * already-dropped column in a JOIN RTE's alias var list, it is possible for
134 : * such a list in a stored rule to include references to dropped columns.
135 : * (If the column is not explicitly referenced anywhere else in the query,
136 : * the dependency mechanism won't consider it used by the rule and so won't
137 : * prevent the column drop.) To support get_rte_attribute_is_dropped(), we
138 : * replace join alias vars that reference dropped columns with null pointers.
139 : *
140 : * (In PostgreSQL 8.0, we did not do this processing but instead had
141 : * get_rte_attribute_is_dropped() recurse to detect dropped columns in joins.
142 : * That approach had horrible performance unfortunately; in particular
143 : * construction of a nested join was O(N^2) in the nesting depth.)
144 : */
145 : void
146 35262 : AcquireRewriteLocks(Query *parsetree,
147 : bool forExecute,
148 : bool forUpdatePushedDown)
149 : {
150 : ListCell *l;
151 : int rt_index;
152 : acquireLocksOnSubLinks_context context;
153 :
154 35262 : context.for_execute = forExecute;
155 :
156 : /*
157 : * First, process RTEs of the current query level.
158 : */
159 35262 : rt_index = 0;
160 100826 : foreach(l, parsetree->rtable)
161 : {
162 65564 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
163 : Relation rel;
164 : LOCKMODE lockmode;
165 : List *newaliasvars;
166 : Index curinputvarno;
167 : RangeTblEntry *curinputrte;
168 : ListCell *ll;
169 :
170 65564 : ++rt_index;
171 65564 : switch (rte->rtekind)
172 : {
173 39588 : case RTE_RELATION:
174 :
175 : /*
176 : * Grab the appropriate lock type for the relation, and do not
177 : * release it until end of transaction. This protects the
178 : * rewriter, planner, and executor against schema changes
179 : * mid-query.
180 : *
181 : * If forExecute is false, ignore rellockmode and just use
182 : * AccessShareLock.
183 : */
184 39588 : if (!forExecute)
185 7786 : lockmode = AccessShareLock;
186 31802 : else if (forUpdatePushedDown)
187 : {
188 : /* Upgrade RTE's lock mode to reflect pushed-down lock */
189 96 : if (rte->rellockmode == AccessShareLock)
190 96 : rte->rellockmode = RowShareLock;
191 96 : lockmode = rte->rellockmode;
192 : }
193 : else
194 31706 : lockmode = rte->rellockmode;
195 :
196 39588 : rel = table_open(rte->relid, lockmode);
197 :
198 : /*
199 : * While we have the relation open, update the RTE's relkind,
200 : * just in case it changed since this rule was made.
201 : */
202 39588 : rte->relkind = rel->rd_rel->relkind;
203 :
204 39588 : table_close(rel, NoLock);
205 39588 : break;
206 :
207 14380 : case RTE_JOIN:
208 :
209 : /*
210 : * Scan the join's alias var list to see if any columns have
211 : * been dropped, and if so replace those Vars with null
212 : * pointers.
213 : *
214 : * Since a join has only two inputs, we can expect to see
215 : * multiple references to the same input RTE; optimize away
216 : * multiple fetches.
217 : */
218 14380 : newaliasvars = NIL;
219 14380 : curinputvarno = 0;
220 14380 : curinputrte = NULL;
221 575790 : foreach(ll, rte->joinaliasvars)
222 : {
223 561410 : Var *aliasitem = (Var *) lfirst(ll);
224 561410 : Var *aliasvar = aliasitem;
225 :
226 : /* Look through any implicit coercion */
227 561410 : aliasvar = (Var *) strip_implicit_coercions((Node *) aliasvar);
228 :
229 : /*
230 : * If the list item isn't a simple Var, then it must
231 : * represent a merged column, ie a USING column, and so it
232 : * couldn't possibly be dropped, since it's referenced in
233 : * the join clause. (Conceivably it could also be a null
234 : * pointer already? But that's OK too.)
235 : */
236 561410 : if (aliasvar && IsA(aliasvar, Var))
237 : {
238 : /*
239 : * The elements of an alias list have to refer to
240 : * earlier RTEs of the same rtable, because that's the
241 : * order the planner builds things in. So we already
242 : * processed the referenced RTE, and so it's safe to
243 : * use get_rte_attribute_is_dropped on it. (This might
244 : * not hold after rewriting or planning, but it's OK
245 : * to assume here.)
246 : */
247 : Assert(aliasvar->varlevelsup == 0);
248 561236 : if (aliasvar->varno != curinputvarno)
249 : {
250 37928 : curinputvarno = aliasvar->varno;
251 37928 : if (curinputvarno >= rt_index)
252 0 : elog(ERROR, "unexpected varno %d in JOIN RTE %d",
253 : curinputvarno, rt_index);
254 37928 : curinputrte = rt_fetch(curinputvarno,
255 : parsetree->rtable);
256 : }
257 561236 : if (get_rte_attribute_is_dropped(curinputrte,
258 561236 : aliasvar->varattno))
259 : {
260 : /* Replace the join alias item with a NULL */
261 6 : aliasitem = NULL;
262 : }
263 : }
264 561410 : newaliasvars = lappend(newaliasvars, aliasitem);
265 : }
266 14380 : rte->joinaliasvars = newaliasvars;
267 14380 : break;
268 :
269 2264 : case RTE_SUBQUERY:
270 :
271 : /*
272 : * The subquery RTE itself is all right, but we have to
273 : * recurse to process the represented subquery.
274 : */
275 2264 : AcquireRewriteLocks(rte->subquery,
276 : forExecute,
277 4528 : (forUpdatePushedDown ||
278 2264 : get_parse_rowmark(parsetree, rt_index) != NULL));
279 2264 : break;
280 :
281 9332 : default:
282 : /* ignore other types of RTEs */
283 9332 : break;
284 : }
285 : }
286 :
287 : /* Recurse into subqueries in WITH */
288 35432 : foreach(l, parsetree->cteList)
289 : {
290 170 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
291 :
292 170 : AcquireRewriteLocks((Query *) cte->ctequery, forExecute, false);
293 : }
294 :
295 : /*
296 : * Recurse into sublink subqueries, too. But we already did the ones in
297 : * the rtable and cteList.
298 : */
299 35262 : if (parsetree->hasSubLinks)
300 1776 : query_tree_walker(parsetree, acquireLocksOnSubLinks, &context,
301 : QTW_IGNORE_RC_SUBQUERIES);
302 35262 : }
303 :
304 : /*
305 : * Walker to find sublink subqueries for AcquireRewriteLocks
306 : */
307 : static bool
308 133364 : acquireLocksOnSubLinks(Node *node, acquireLocksOnSubLinks_context *context)
309 : {
310 133364 : if (node == NULL)
311 31364 : return false;
312 102000 : if (IsA(node, SubLink))
313 : {
314 3920 : SubLink *sub = (SubLink *) node;
315 :
316 : /* Do what we came for */
317 3920 : AcquireRewriteLocks((Query *) sub->subselect,
318 3920 : context->for_execute,
319 : false);
320 : /* Fall through to process lefthand args of SubLink */
321 : }
322 :
323 : /*
324 : * Do NOT recurse into Query nodes, because AcquireRewriteLocks already
325 : * processed subselects of subselects for us.
326 : */
327 102000 : return expression_tree_walker(node, acquireLocksOnSubLinks, context);
328 : }
329 :
330 :
331 : /*
332 : * rewriteRuleAction -
333 : * Rewrite the rule action with appropriate qualifiers (taken from
334 : * the triggering query).
335 : *
336 : * Input arguments:
337 : * parsetree - original query
338 : * rule_action - one action (query) of a rule
339 : * rule_qual - WHERE condition of rule, or NULL if unconditional
340 : * rt_index - RT index of result relation in original query
341 : * event - type of rule event
342 : * Output arguments:
343 : * *returning_flag - set true if we rewrite RETURNING clause in rule_action
344 : * (must be initialized to false)
345 : * Return value:
346 : * rewritten form of rule_action
347 : */
348 : static Query *
349 1344 : rewriteRuleAction(Query *parsetree,
350 : Query *rule_action,
351 : Node *rule_qual,
352 : int rt_index,
353 : CmdType event,
354 : bool *returning_flag)
355 : {
356 : int current_varno,
357 : new_varno;
358 : int rt_length;
359 : Query *sub_action;
360 : Query **sub_action_ptr;
361 : acquireLocksOnSubLinks_context context;
362 : ListCell *lc;
363 :
364 1344 : context.for_execute = true;
365 :
366 : /*
367 : * Make modifiable copies of rule action and qual (what we're passed are
368 : * the stored versions in the relcache; don't touch 'em!).
369 : */
370 1344 : rule_action = copyObject(rule_action);
371 1344 : rule_qual = copyObject(rule_qual);
372 :
373 : /*
374 : * Acquire necessary locks and fix any deleted JOIN RTE entries.
375 : */
376 1344 : AcquireRewriteLocks(rule_action, true, false);
377 1344 : (void) acquireLocksOnSubLinks(rule_qual, &context);
378 :
379 1344 : current_varno = rt_index;
380 1344 : rt_length = list_length(parsetree->rtable);
381 1344 : new_varno = PRS2_NEW_VARNO + rt_length;
382 :
383 : /*
384 : * Adjust rule action and qual to offset its varnos, so that we can merge
385 : * its rtable with the main parsetree's rtable.
386 : *
387 : * If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries
388 : * will be in the SELECT part, and we have to modify that rather than the
389 : * top-level INSERT (kluge!).
390 : */
391 1344 : sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr);
392 :
393 1344 : OffsetVarNodes((Node *) sub_action, rt_length, 0);
394 1344 : OffsetVarNodes(rule_qual, rt_length, 0);
395 : /* but references to OLD should point at original rt_index */
396 1344 : ChangeVarNodes((Node *) sub_action,
397 : PRS2_OLD_VARNO + rt_length, rt_index, 0);
398 1344 : ChangeVarNodes(rule_qual,
399 : PRS2_OLD_VARNO + rt_length, rt_index, 0);
400 :
401 : /*
402 : * Mark any subquery RTEs in the rule action as LATERAL if they contain
403 : * Vars referring to the current query level (references to NEW/OLD).
404 : * Those really are lateral references, but we've historically not
405 : * required users to mark such subqueries with LATERAL explicitly. But
406 : * the planner will complain if such Vars exist in a non-LATERAL subquery,
407 : * so we have to fix things up here.
408 : */
409 5304 : foreach(lc, sub_action->rtable)
410 : {
411 3960 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
412 :
413 3972 : if (rte->rtekind == RTE_SUBQUERY && !rte->lateral &&
414 12 : contain_vars_of_level((Node *) rte->subquery, 1))
415 12 : rte->lateral = true;
416 : }
417 :
418 : /*
419 : * Generate expanded rtable consisting of main parsetree's rtable plus
420 : * rule action's rtable; this becomes the complete rtable for the rule
421 : * action. Some of the entries may be unused after we finish rewriting,
422 : * but we leave them all in place to avoid having to adjust the query's
423 : * varnos. RT entries that are not referenced in the completed jointree
424 : * will be ignored by the planner, so they do not affect query semantics.
425 : *
426 : * Also merge RTEPermissionInfo lists to ensure that all permissions are
427 : * checked correctly.
428 : *
429 : * If the rule is INSTEAD, then the original query won't be executed at
430 : * all, and so its rteperminfos must be preserved so that the executor
431 : * will do the correct permissions checks on the relations referenced in
432 : * it. This allows us to check that the caller has, say, insert-permission
433 : * on a view, when the view is not semantically referenced at all in the
434 : * resulting query.
435 : *
436 : * When a rule is not INSTEAD, the permissions checks done using the
437 : * copied entries will be redundant with those done during execution of
438 : * the original query, but we don't bother to treat that case differently.
439 : *
440 : * NOTE: because planner will destructively alter rtable and rteperminfos,
441 : * we must ensure that rule action's lists are separate and shares no
442 : * substructure with the main query's lists. Hence do a deep copy here
443 : * for both.
444 : */
445 : {
446 1344 : List *rtable_tail = sub_action->rtable;
447 1344 : List *perminfos_tail = sub_action->rteperminfos;
448 :
449 : /*
450 : * RewriteQuery relies on the fact that RT entries from the original
451 : * query appear at the start of the expanded rtable, so we put the
452 : * action's original table at the end of the list.
453 : */
454 1344 : sub_action->rtable = copyObject(parsetree->rtable);
455 1344 : sub_action->rteperminfos = copyObject(parsetree->rteperminfos);
456 1344 : CombineRangeTables(&sub_action->rtable, &sub_action->rteperminfos,
457 : rtable_tail, perminfos_tail);
458 : }
459 :
460 : /*
461 : * There could have been some SubLinks in parsetree's rtable, in which
462 : * case we'd better mark the sub_action correctly.
463 : */
464 1344 : if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
465 : {
466 66 : foreach(lc, parsetree->rtable)
467 : {
468 48 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
469 :
470 48 : switch (rte->rtekind)
471 : {
472 42 : case RTE_RELATION:
473 42 : sub_action->hasSubLinks =
474 42 : checkExprHasSubLink((Node *) rte->tablesample);
475 42 : break;
476 0 : case RTE_FUNCTION:
477 0 : sub_action->hasSubLinks =
478 0 : checkExprHasSubLink((Node *) rte->functions);
479 0 : break;
480 0 : case RTE_TABLEFUNC:
481 0 : sub_action->hasSubLinks =
482 0 : checkExprHasSubLink((Node *) rte->tablefunc);
483 0 : break;
484 0 : case RTE_VALUES:
485 0 : sub_action->hasSubLinks =
486 0 : checkExprHasSubLink((Node *) rte->values_lists);
487 0 : break;
488 6 : default:
489 : /* other RTE types don't contain bare expressions */
490 6 : break;
491 : }
492 48 : sub_action->hasSubLinks |=
493 48 : checkExprHasSubLink((Node *) rte->securityQuals);
494 48 : if (sub_action->hasSubLinks)
495 6 : break; /* no need to keep scanning rtable */
496 : }
497 : }
498 :
499 : /*
500 : * Also, we might have absorbed some RTEs with RLS conditions into the
501 : * sub_action. If so, mark it as hasRowSecurity, whether or not those
502 : * RTEs will be referenced after we finish rewriting. (Note: currently
503 : * this is a no-op because RLS conditions aren't added till later, but it
504 : * seems like good future-proofing to do this anyway.)
505 : */
506 1344 : sub_action->hasRowSecurity |= parsetree->hasRowSecurity;
507 :
508 : /*
509 : * Each rule action's jointree should be the main parsetree's jointree
510 : * plus that rule's jointree, but usually *without* the original rtindex
511 : * that we're replacing (if present, which it won't be for INSERT). Note
512 : * that if the rule action refers to OLD, its jointree will add a
513 : * reference to rt_index. If the rule action doesn't refer to OLD, but
514 : * either the rule_qual or the user query quals do, then we need to keep
515 : * the original rtindex in the jointree to provide data for the quals. We
516 : * don't want the original rtindex to be joined twice, however, so avoid
517 : * keeping it if the rule action mentions it.
518 : *
519 : * As above, the action's jointree must not share substructure with the
520 : * main parsetree's.
521 : */
522 1344 : if (sub_action->commandType != CMD_UTILITY)
523 : {
524 : bool keeporig;
525 : List *newjointree;
526 :
527 : Assert(sub_action->jointree != NULL);
528 1314 : keeporig = (!rangeTableEntry_used((Node *) sub_action->jointree,
529 3114 : rt_index, 0)) &&
530 1800 : (rangeTableEntry_used(rule_qual, rt_index, 0) ||
531 900 : rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0));
532 1314 : newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index);
533 1314 : if (newjointree != NIL)
534 : {
535 : /*
536 : * If sub_action is a setop, manipulating its jointree will do no
537 : * good at all, because the jointree is dummy. (Perhaps someday
538 : * we could push the joining and quals down to the member
539 : * statements of the setop?)
540 : */
541 276 : if (sub_action->setOperations != NULL)
542 0 : ereport(ERROR,
543 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
544 : errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
545 :
546 552 : sub_action->jointree->fromlist =
547 276 : list_concat(newjointree, sub_action->jointree->fromlist);
548 :
549 : /*
550 : * There could have been some SubLinks in newjointree, in which
551 : * case we'd better mark the sub_action correctly.
552 : */
553 276 : if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
554 6 : sub_action->hasSubLinks =
555 6 : checkExprHasSubLink((Node *) newjointree);
556 : }
557 : }
558 :
559 : /*
560 : * If the original query has any CTEs, copy them into the rule action. But
561 : * we don't need them for a utility action.
562 : */
563 1344 : if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY)
564 : {
565 : /*
566 : * Annoying implementation restriction: because CTEs are identified by
567 : * name within a cteList, we can't merge a CTE from the original query
568 : * if it has the same name as any CTE in the rule action.
569 : *
570 : * This could possibly be fixed by using some sort of internally
571 : * generated ID, instead of names, to link CTE RTEs to their CTEs.
572 : * However, decompiling the results would be quite confusing; note the
573 : * merge of hasRecursive flags below, which could change the apparent
574 : * semantics of such redundantly-named CTEs.
575 : */
576 60 : foreach(lc, parsetree->cteList)
577 : {
578 30 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
579 : ListCell *lc2;
580 :
581 30 : foreach(lc2, sub_action->cteList)
582 : {
583 0 : CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(lc2);
584 :
585 0 : if (strcmp(cte->ctename, cte2->ctename) == 0)
586 0 : ereport(ERROR,
587 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
588 : errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten",
589 : cte->ctename)));
590 : }
591 : }
592 :
593 : /* OK, it's safe to combine the CTE lists */
594 30 : sub_action->cteList = list_concat(sub_action->cteList,
595 30 : copyObject(parsetree->cteList));
596 : /* ... and don't forget about the associated flags */
597 30 : sub_action->hasRecursive |= parsetree->hasRecursive;
598 30 : sub_action->hasModifyingCTE |= parsetree->hasModifyingCTE;
599 :
600 : /*
601 : * If rule_action is different from sub_action (i.e., the rule action
602 : * is an INSERT...SELECT), then we might have just added some
603 : * data-modifying CTEs that are not at the top query level. This is
604 : * disallowed by the parser and we mustn't generate such trees here
605 : * either, so throw an error.
606 : *
607 : * Conceivably such cases could be supported by attaching the original
608 : * query's CTEs to rule_action not sub_action. But to do that, we'd
609 : * have to increment ctelevelsup in RTEs and SubLinks copied from the
610 : * original query. For now, it doesn't seem worth the trouble.
611 : */
612 30 : if (sub_action->hasModifyingCTE && rule_action != sub_action)
613 6 : ereport(ERROR,
614 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
615 : errmsg("INSERT ... SELECT rule actions are not supported for queries having data-modifying statements in WITH")));
616 : }
617 :
618 : /*
619 : * Event Qualification forces copying of parsetree and splitting into two
620 : * queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual
621 : * onto rule action
622 : */
623 1338 : AddQual(sub_action, rule_qual);
624 :
625 1338 : AddQual(sub_action, parsetree->jointree->quals);
626 :
627 : /*
628 : * Rewrite new.attribute with right hand side of target-list entry for
629 : * appropriate field name in insert/update.
630 : *
631 : * KLUGE ALERT: since ReplaceVarsFromTargetList returns a mutated copy, we
632 : * can't just apply it to sub_action; we have to remember to update the
633 : * sublink inside rule_action, too.
634 : */
635 1338 : if ((event == CMD_INSERT || event == CMD_UPDATE) &&
636 1176 : sub_action->commandType != CMD_UTILITY)
637 : {
638 : sub_action = (Query *)
639 2292 : ReplaceVarsFromTargetList((Node *) sub_action,
640 : new_varno,
641 : 0,
642 1146 : rt_fetch(new_varno, sub_action->rtable),
643 : parsetree->targetList,
644 : (event == CMD_UPDATE) ?
645 : REPLACEVARS_CHANGE_VARNO :
646 : REPLACEVARS_SUBSTITUTE_NULL,
647 : current_varno,
648 : NULL);
649 1146 : if (sub_action_ptr)
650 54 : *sub_action_ptr = sub_action;
651 : else
652 1092 : rule_action = sub_action;
653 : }
654 :
655 : /*
656 : * If rule_action has a RETURNING clause, then either throw it away if the
657 : * triggering query has no RETURNING clause, or rewrite it to emit what
658 : * the triggering query's RETURNING clause asks for. Throw an error if
659 : * more than one rule has a RETURNING clause.
660 : */
661 1338 : if (!parsetree->returningList)
662 1218 : rule_action->returningList = NIL;
663 120 : else if (rule_action->returningList)
664 : {
665 108 : if (*returning_flag)
666 0 : ereport(ERROR,
667 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
668 : errmsg("cannot have RETURNING lists in multiple rules")));
669 108 : *returning_flag = true;
670 108 : rule_action->returningList = (List *)
671 108 : ReplaceVarsFromTargetList((Node *) parsetree->returningList,
672 : parsetree->resultRelation,
673 : 0,
674 108 : rt_fetch(parsetree->resultRelation,
675 : parsetree->rtable),
676 : rule_action->returningList,
677 : REPLACEVARS_REPORT_ERROR,
678 : 0,
679 : &rule_action->hasSubLinks);
680 :
681 : /*
682 : * There could have been some SubLinks in parsetree's returningList,
683 : * in which case we'd better mark the rule_action correctly.
684 : */
685 108 : if (parsetree->hasSubLinks && !rule_action->hasSubLinks)
686 0 : rule_action->hasSubLinks =
687 0 : checkExprHasSubLink((Node *) rule_action->returningList);
688 : }
689 :
690 1338 : return rule_action;
691 : }
692 :
693 : /*
694 : * Copy the query's jointree list, and optionally attempt to remove any
695 : * occurrence of the given rt_index as a top-level join item (we do not look
696 : * for it within join items; this is OK because we are only expecting to find
697 : * it as an UPDATE or DELETE target relation, which will be at the top level
698 : * of the join). Returns modified jointree list --- this is a separate copy
699 : * sharing no nodes with the original.
700 : */
701 : static List *
702 1314 : adjustJoinTreeList(Query *parsetree, bool removert, int rt_index)
703 : {
704 1314 : List *newjointree = copyObject(parsetree->jointree->fromlist);
705 : ListCell *l;
706 :
707 1314 : if (removert)
708 : {
709 1554 : foreach(l, newjointree)
710 : {
711 708 : RangeTblRef *rtr = lfirst(l);
712 :
713 708 : if (IsA(rtr, RangeTblRef) &&
714 708 : rtr->rtindex == rt_index)
715 : {
716 468 : newjointree = foreach_delete_current(newjointree, l);
717 468 : break;
718 : }
719 : }
720 : }
721 1314 : return newjointree;
722 : }
723 :
724 :
725 : /*
726 : * rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form
727 : *
728 : * This has the following responsibilities:
729 : *
730 : * 1. For an INSERT, add tlist entries to compute default values for any
731 : * attributes that have defaults and are not assigned to in the given tlist.
732 : * (We do not insert anything for default-less attributes, however. The
733 : * planner will later insert NULLs for them, but there's no reason to slow
734 : * down rewriter processing with extra tlist nodes.) Also, for both INSERT
735 : * and UPDATE, replace explicit DEFAULT specifications with column default
736 : * expressions.
737 : *
738 : * 2. Merge multiple entries for the same target attribute, or declare error
739 : * if we can't. Multiple entries are only allowed for INSERT/UPDATE of
740 : * portions of an array or record field, for example
741 : * UPDATE table SET foo[2] = 42, foo[4] = 43;
742 : * We can merge such operations into a single assignment op. Essentially,
743 : * the expression we want to produce in this case is like
744 : * foo = array_set_element(array_set_element(foo, 2, 42), 4, 43)
745 : *
746 : * 3. Sort the tlist into standard order: non-junk fields in order by resno,
747 : * then junk fields (these in no particular order).
748 : *
749 : * We must do items 1 and 2 before firing rewrite rules, else rewritten
750 : * references to NEW.foo will produce wrong or incomplete results. Item 3
751 : * is not needed for rewriting, but it is helpful for the planner, and we
752 : * can do it essentially for free while handling the other items.
753 : *
754 : * If values_rte is non-NULL (i.e., we are doing a multi-row INSERT using
755 : * values from a VALUES RTE), we populate *unused_values_attrnos with the
756 : * attribute numbers of any unused columns from the VALUES RTE. This can
757 : * happen for identity and generated columns whose targetlist entries are
758 : * replaced with generated expressions (if INSERT ... OVERRIDING USER VALUE is
759 : * used, or all the values to be inserted are DEFAULT). This information is
760 : * required by rewriteValuesRTE() to handle any DEFAULT items in the unused
761 : * columns. The caller must have initialized *unused_values_attrnos to NULL.
762 : */
763 : static List *
764 91114 : rewriteTargetListIU(List *targetList,
765 : CmdType commandType,
766 : OverridingKind override,
767 : Relation target_relation,
768 : RangeTblEntry *values_rte,
769 : int values_rte_index,
770 : Bitmapset **unused_values_attrnos)
771 : {
772 : TargetEntry **new_tles;
773 91114 : List *new_tlist = NIL;
774 91114 : List *junk_tlist = NIL;
775 : Form_pg_attribute att_tup;
776 : int attrno,
777 : next_junk_attrno,
778 : numattrs;
779 : ListCell *temp;
780 91114 : Bitmapset *default_only_cols = NULL;
781 :
782 : /*
783 : * We process the normal (non-junk) attributes by scanning the input tlist
784 : * once and transferring TLEs into an array, then scanning the array to
785 : * build an output tlist. This avoids O(N^2) behavior for large numbers
786 : * of attributes.
787 : *
788 : * Junk attributes are tossed into a separate list during the same tlist
789 : * scan, then appended to the reconstructed tlist.
790 : */
791 91114 : numattrs = RelationGetNumberOfAttributes(target_relation);
792 91114 : new_tles = (TargetEntry **) palloc0(numattrs * sizeof(TargetEntry *));
793 91114 : next_junk_attrno = numattrs + 1;
794 :
795 250302 : foreach(temp, targetList)
796 : {
797 159206 : TargetEntry *old_tle = (TargetEntry *) lfirst(temp);
798 :
799 159206 : if (!old_tle->resjunk)
800 : {
801 : /* Normal attr: stash it into new_tles[] */
802 159074 : attrno = old_tle->resno;
803 159074 : if (attrno < 1 || attrno > numattrs)
804 0 : elog(ERROR, "bogus resno %d in targetlist", attrno);
805 159074 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
806 :
807 : /* We can (and must) ignore deleted attributes */
808 159074 : if (att_tup->attisdropped)
809 0 : continue;
810 :
811 : /* Merge with any prior assignment to same attribute */
812 159056 : new_tles[attrno - 1] =
813 159074 : process_matched_tle(old_tle,
814 159074 : new_tles[attrno - 1],
815 159074 : NameStr(att_tup->attname));
816 : }
817 : else
818 : {
819 : /*
820 : * Copy all resjunk tlist entries to junk_tlist, and assign them
821 : * resnos above the last real resno.
822 : *
823 : * Typical junk entries include ORDER BY or GROUP BY expressions
824 : * (are these actually possible in an INSERT or UPDATE?), system
825 : * attribute references, etc.
826 : */
827 :
828 : /* Get the resno right, but don't copy unnecessarily */
829 132 : if (old_tle->resno != next_junk_attrno)
830 : {
831 0 : old_tle = flatCopyTargetEntry(old_tle);
832 0 : old_tle->resno = next_junk_attrno;
833 : }
834 132 : junk_tlist = lappend(junk_tlist, old_tle);
835 132 : next_junk_attrno++;
836 : }
837 : }
838 :
839 379086 : for (attrno = 1; attrno <= numattrs; attrno++)
840 : {
841 288116 : TargetEntry *new_tle = new_tles[attrno - 1];
842 : bool apply_default;
843 :
844 288116 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
845 :
846 : /* We can (and must) ignore deleted attributes */
847 288116 : if (att_tup->attisdropped)
848 908 : continue;
849 :
850 : /*
851 : * Handle the two cases where we need to insert a default expression:
852 : * it's an INSERT and there's no tlist entry for the column, or the
853 : * tlist entry is a DEFAULT placeholder node.
854 : */
855 445872 : apply_default = ((new_tle == NULL && commandType == CMD_INSERT) ||
856 158664 : (new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault)));
857 :
858 287208 : if (commandType == CMD_INSERT)
859 : {
860 162508 : int values_attrno = 0;
861 :
862 : /* Source attribute number for values that come from a VALUES RTE */
863 162508 : if (values_rte && new_tle && IsA(new_tle->expr, Var))
864 : {
865 7958 : Var *var = (Var *) new_tle->expr;
866 :
867 7958 : if (var->varno == values_rte_index)
868 7958 : values_attrno = var->varattno;
869 : }
870 :
871 : /*
872 : * Can only insert DEFAULT into GENERATED ALWAYS identity columns,
873 : * unless either OVERRIDING USER VALUE or OVERRIDING SYSTEM VALUE
874 : * is specified.
875 : */
876 162508 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS && !apply_default)
877 : {
878 142 : if (override == OVERRIDING_USER_VALUE)
879 42 : apply_default = true;
880 100 : else if (override != OVERRIDING_SYSTEM_VALUE)
881 : {
882 : /*
883 : * If this column's values come from a VALUES RTE, test
884 : * whether it contains only SetToDefault items. Since the
885 : * VALUES list might be quite large, we arrange to only
886 : * scan it once.
887 : */
888 52 : if (values_attrno != 0)
889 : {
890 28 : if (default_only_cols == NULL)
891 28 : default_only_cols = findDefaultOnlyColumns(values_rte);
892 :
893 28 : if (bms_is_member(values_attrno, default_only_cols))
894 10 : apply_default = true;
895 : }
896 :
897 52 : if (!apply_default)
898 42 : ereport(ERROR,
899 : (errcode(ERRCODE_GENERATED_ALWAYS),
900 : errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
901 : NameStr(att_tup->attname)),
902 : errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
903 : NameStr(att_tup->attname)),
904 : errhint("Use OVERRIDING SYSTEM VALUE to override.")));
905 : }
906 : }
907 :
908 : /*
909 : * Although inserting into a GENERATED BY DEFAULT identity column
910 : * is allowed, apply the default if OVERRIDING USER VALUE is
911 : * specified.
912 : */
913 162466 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_BY_DEFAULT &&
914 : override == OVERRIDING_USER_VALUE)
915 18 : apply_default = true;
916 :
917 : /*
918 : * Can only insert DEFAULT into generated columns, regardless of
919 : * any OVERRIDING clauses.
920 : */
921 162466 : if (att_tup->attgenerated && !apply_default)
922 : {
923 : /*
924 : * If this column's values come from a VALUES RTE, test
925 : * whether it contains only SetToDefault items, as above.
926 : */
927 86 : if (values_attrno != 0)
928 : {
929 56 : if (default_only_cols == NULL)
930 56 : default_only_cols = findDefaultOnlyColumns(values_rte);
931 :
932 56 : if (bms_is_member(values_attrno, default_only_cols))
933 14 : apply_default = true;
934 : }
935 :
936 86 : if (!apply_default)
937 72 : ereport(ERROR,
938 : (errcode(ERRCODE_GENERATED_ALWAYS),
939 : errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
940 : NameStr(att_tup->attname)),
941 : errdetail("Column \"%s\" is a generated column.",
942 : NameStr(att_tup->attname))));
943 : }
944 :
945 : /*
946 : * For an INSERT from a VALUES RTE, return the attribute numbers
947 : * of any VALUES columns that will no longer be used (due to the
948 : * targetlist entry being replaced by a default expression).
949 : */
950 162394 : if (values_attrno != 0 && apply_default && unused_values_attrnos)
951 48 : *unused_values_attrnos = bms_add_member(*unused_values_attrnos,
952 : values_attrno);
953 : }
954 :
955 : /*
956 : * Updates to identity and generated columns follow the same rules as
957 : * above, except that UPDATE doesn't admit OVERRIDING clauses. Also,
958 : * the source can't be a VALUES RTE, so we needn't consider that.
959 : */
960 287094 : if (commandType == CMD_UPDATE)
961 : {
962 124700 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS &&
963 12 : new_tle && !apply_default)
964 6 : ereport(ERROR,
965 : (errcode(ERRCODE_GENERATED_ALWAYS),
966 : errmsg("column \"%s\" can only be updated to DEFAULT",
967 : NameStr(att_tup->attname)),
968 : errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
969 : NameStr(att_tup->attname))));
970 :
971 124694 : if (att_tup->attgenerated && new_tle && !apply_default)
972 6 : ereport(ERROR,
973 : (errcode(ERRCODE_GENERATED_ALWAYS),
974 : errmsg("column \"%s\" can only be updated to DEFAULT",
975 : NameStr(att_tup->attname)),
976 : errdetail("Column \"%s\" is a generated column.",
977 : NameStr(att_tup->attname))));
978 : }
979 :
980 287082 : if (att_tup->attgenerated)
981 : {
982 : /*
983 : * stored generated column will be fixed in executor
984 : */
985 956 : new_tle = NULL;
986 : }
987 286126 : else if (apply_default)
988 : {
989 : Node *new_expr;
990 :
991 25110 : new_expr = build_column_default(target_relation, attrno);
992 :
993 : /*
994 : * If there is no default (ie, default is effectively NULL), we
995 : * can omit the tlist entry in the INSERT case, since the planner
996 : * can insert a NULL for itself, and there's no point in spending
997 : * any more rewriter cycles on the entry. But in the UPDATE case
998 : * we've got to explicitly set the column to NULL.
999 : */
1000 25110 : if (!new_expr)
1001 : {
1002 18550 : if (commandType == CMD_INSERT)
1003 18528 : new_tle = NULL;
1004 : else
1005 : {
1006 22 : new_expr = (Node *) makeConst(att_tup->atttypid,
1007 : -1,
1008 : att_tup->attcollation,
1009 22 : att_tup->attlen,
1010 : (Datum) 0,
1011 : true, /* isnull */
1012 22 : att_tup->attbyval);
1013 : /* this is to catch a NOT NULL domain constraint */
1014 22 : new_expr = coerce_to_domain(new_expr,
1015 : InvalidOid, -1,
1016 : att_tup->atttypid,
1017 : COERCION_IMPLICIT,
1018 : COERCE_IMPLICIT_CAST,
1019 : -1,
1020 : false);
1021 : }
1022 : }
1023 :
1024 25110 : if (new_expr)
1025 6582 : new_tle = makeTargetEntry((Expr *) new_expr,
1026 : attrno,
1027 6582 : pstrdup(NameStr(att_tup->attname)),
1028 : false);
1029 : }
1030 :
1031 287082 : if (new_tle)
1032 164374 : new_tlist = lappend(new_tlist, new_tle);
1033 : }
1034 :
1035 90970 : pfree(new_tles);
1036 :
1037 90970 : return list_concat(new_tlist, junk_tlist);
1038 : }
1039 :
1040 :
1041 : /*
1042 : * Convert a matched TLE from the original tlist into a correct new TLE.
1043 : *
1044 : * This routine detects and handles multiple assignments to the same target
1045 : * attribute. (The attribute name is needed only for error messages.)
1046 : */
1047 : static TargetEntry *
1048 159074 : process_matched_tle(TargetEntry *src_tle,
1049 : TargetEntry *prior_tle,
1050 : const char *attrName)
1051 : {
1052 : TargetEntry *result;
1053 159074 : CoerceToDomain *coerce_expr = NULL;
1054 : Node *src_expr;
1055 : Node *prior_expr;
1056 : Node *src_input;
1057 : Node *prior_input;
1058 : Node *priorbottom;
1059 : Node *newexpr;
1060 :
1061 159074 : if (prior_tle == NULL)
1062 : {
1063 : /*
1064 : * Normal case where this is the first assignment to the attribute.
1065 : */
1066 158736 : return src_tle;
1067 : }
1068 :
1069 : /*----------
1070 : * Multiple assignments to same attribute. Allow only if all are
1071 : * FieldStore or SubscriptingRef assignment operations. This is a bit
1072 : * tricky because what we may actually be looking at is a nest of
1073 : * such nodes; consider
1074 : * UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y
1075 : * The two expressions produced by the parser will look like
1076 : * FieldStore(col, fld1, FieldStore(placeholder, subfld1, x))
1077 : * FieldStore(col, fld2, FieldStore(placeholder, subfld2, y))
1078 : * However, we can ignore the substructure and just consider the top
1079 : * FieldStore or SubscriptingRef from each assignment, because it works to
1080 : * combine these as
1081 : * FieldStore(FieldStore(col, fld1,
1082 : * FieldStore(placeholder, subfld1, x)),
1083 : * fld2, FieldStore(placeholder, subfld2, y))
1084 : * Note the leftmost expression goes on the inside so that the
1085 : * assignments appear to occur left-to-right.
1086 : *
1087 : * For FieldStore, instead of nesting we can generate a single
1088 : * FieldStore with multiple target fields. We must nest when
1089 : * SubscriptingRefs are involved though.
1090 : *
1091 : * As a further complication, the destination column might be a domain,
1092 : * resulting in each assignment containing a CoerceToDomain node over a
1093 : * FieldStore or SubscriptingRef. These should have matching target
1094 : * domains, so we strip them and reconstitute a single CoerceToDomain over
1095 : * the combined FieldStore/SubscriptingRef nodes. (Notice that this has
1096 : * the result that the domain's checks are applied only after we do all
1097 : * the field or element updates, not after each one. This is desirable.)
1098 : *----------
1099 : */
1100 338 : src_expr = (Node *) src_tle->expr;
1101 338 : prior_expr = (Node *) prior_tle->expr;
1102 :
1103 338 : if (src_expr && IsA(src_expr, CoerceToDomain) &&
1104 162 : prior_expr && IsA(prior_expr, CoerceToDomain) &&
1105 162 : ((CoerceToDomain *) src_expr)->resulttype ==
1106 162 : ((CoerceToDomain *) prior_expr)->resulttype)
1107 : {
1108 : /* we assume without checking that resulttypmod/resultcollid match */
1109 162 : coerce_expr = (CoerceToDomain *) src_expr;
1110 162 : src_expr = (Node *) ((CoerceToDomain *) src_expr)->arg;
1111 162 : prior_expr = (Node *) ((CoerceToDomain *) prior_expr)->arg;
1112 : }
1113 :
1114 338 : src_input = get_assignment_input(src_expr);
1115 338 : prior_input = get_assignment_input(prior_expr);
1116 338 : if (src_input == NULL ||
1117 320 : prior_input == NULL ||
1118 320 : exprType(src_expr) != exprType(prior_expr))
1119 18 : ereport(ERROR,
1120 : (errcode(ERRCODE_SYNTAX_ERROR),
1121 : errmsg("multiple assignments to same column \"%s\"",
1122 : attrName)));
1123 :
1124 : /*
1125 : * Prior TLE could be a nest of assignments if we do this more than once.
1126 : */
1127 320 : priorbottom = prior_input;
1128 : for (;;)
1129 42 : {
1130 362 : Node *newbottom = get_assignment_input(priorbottom);
1131 :
1132 362 : if (newbottom == NULL)
1133 320 : break; /* found the original Var reference */
1134 42 : priorbottom = newbottom;
1135 : }
1136 320 : if (!equal(priorbottom, src_input))
1137 0 : ereport(ERROR,
1138 : (errcode(ERRCODE_SYNTAX_ERROR),
1139 : errmsg("multiple assignments to same column \"%s\"",
1140 : attrName)));
1141 :
1142 : /*
1143 : * Looks OK to nest 'em.
1144 : */
1145 320 : if (IsA(src_expr, FieldStore))
1146 : {
1147 126 : FieldStore *fstore = makeNode(FieldStore);
1148 :
1149 126 : if (IsA(prior_expr, FieldStore))
1150 : {
1151 : /* combine the two */
1152 126 : memcpy(fstore, prior_expr, sizeof(FieldStore));
1153 126 : fstore->newvals =
1154 126 : list_concat_copy(((FieldStore *) prior_expr)->newvals,
1155 126 : ((FieldStore *) src_expr)->newvals);
1156 126 : fstore->fieldnums =
1157 126 : list_concat_copy(((FieldStore *) prior_expr)->fieldnums,
1158 126 : ((FieldStore *) src_expr)->fieldnums);
1159 : }
1160 : else
1161 : {
1162 : /* general case, just nest 'em */
1163 0 : memcpy(fstore, src_expr, sizeof(FieldStore));
1164 0 : fstore->arg = (Expr *) prior_expr;
1165 : }
1166 126 : newexpr = (Node *) fstore;
1167 : }
1168 194 : else if (IsA(src_expr, SubscriptingRef))
1169 : {
1170 194 : SubscriptingRef *sbsref = makeNode(SubscriptingRef);
1171 :
1172 194 : memcpy(sbsref, src_expr, sizeof(SubscriptingRef));
1173 194 : sbsref->refexpr = (Expr *) prior_expr;
1174 194 : newexpr = (Node *) sbsref;
1175 : }
1176 : else
1177 : {
1178 0 : elog(ERROR, "cannot happen");
1179 : newexpr = NULL;
1180 : }
1181 :
1182 320 : if (coerce_expr)
1183 : {
1184 : /* put back the CoerceToDomain */
1185 162 : CoerceToDomain *newcoerce = makeNode(CoerceToDomain);
1186 :
1187 162 : memcpy(newcoerce, coerce_expr, sizeof(CoerceToDomain));
1188 162 : newcoerce->arg = (Expr *) newexpr;
1189 162 : newexpr = (Node *) newcoerce;
1190 : }
1191 :
1192 320 : result = flatCopyTargetEntry(src_tle);
1193 320 : result->expr = (Expr *) newexpr;
1194 320 : return result;
1195 : }
1196 :
1197 : /*
1198 : * If node is an assignment node, return its input; else return NULL
1199 : */
1200 : static Node *
1201 1038 : get_assignment_input(Node *node)
1202 : {
1203 1038 : if (node == NULL)
1204 0 : return NULL;
1205 1038 : if (IsA(node, FieldStore))
1206 : {
1207 252 : FieldStore *fstore = (FieldStore *) node;
1208 :
1209 252 : return (Node *) fstore->arg;
1210 : }
1211 786 : else if (IsA(node, SubscriptingRef))
1212 : {
1213 430 : SubscriptingRef *sbsref = (SubscriptingRef *) node;
1214 :
1215 430 : if (sbsref->refassgnexpr == NULL)
1216 0 : return NULL;
1217 :
1218 430 : return (Node *) sbsref->refexpr;
1219 : }
1220 :
1221 356 : return NULL;
1222 : }
1223 :
1224 : /*
1225 : * Make an expression tree for the default value for a column.
1226 : *
1227 : * If there is no default, return a NULL instead.
1228 : */
1229 : Node *
1230 186080 : build_column_default(Relation rel, int attrno)
1231 : {
1232 186080 : TupleDesc rd_att = rel->rd_att;
1233 186080 : Form_pg_attribute att_tup = TupleDescAttr(rd_att, attrno - 1);
1234 186080 : Oid atttype = att_tup->atttypid;
1235 186080 : int32 atttypmod = att_tup->atttypmod;
1236 186080 : Node *expr = NULL;
1237 : Oid exprtype;
1238 :
1239 186080 : if (att_tup->attidentity)
1240 : {
1241 462 : NextValueExpr *nve = makeNode(NextValueExpr);
1242 :
1243 462 : nve->seqid = getIdentitySequence(rel, attrno, false);
1244 462 : nve->typeId = att_tup->atttypid;
1245 :
1246 462 : return (Node *) nve;
1247 : }
1248 :
1249 : /*
1250 : * If relation has a default for this column, fetch that expression.
1251 : */
1252 185618 : if (att_tup->atthasdef)
1253 : {
1254 148470 : expr = TupleDescGetDefault(rd_att, attrno);
1255 148470 : if (expr == NULL)
1256 0 : elog(ERROR, "default expression not found for attribute %d of relation \"%s\"",
1257 : attrno, RelationGetRelationName(rel));
1258 : }
1259 :
1260 : /*
1261 : * No per-column default, so look for a default for the type itself. But
1262 : * not for generated columns.
1263 : */
1264 185618 : if (expr == NULL && !att_tup->attgenerated)
1265 37148 : expr = get_typdefault(atttype);
1266 :
1267 185618 : if (expr == NULL)
1268 36930 : return NULL; /* No default anywhere */
1269 :
1270 : /*
1271 : * Make sure the value is coerced to the target column type; this will
1272 : * generally be true already, but there seem to be some corner cases
1273 : * involving domain defaults where it might not be true. This should match
1274 : * the parser's processing of non-defaulted expressions --- see
1275 : * transformAssignedExpr().
1276 : */
1277 148688 : exprtype = exprType(expr);
1278 :
1279 148688 : expr = coerce_to_target_type(NULL, /* no UNKNOWN params here */
1280 : expr, exprtype,
1281 : atttype, atttypmod,
1282 : COERCION_ASSIGNMENT,
1283 : COERCE_IMPLICIT_CAST,
1284 : -1);
1285 148688 : if (expr == NULL)
1286 0 : ereport(ERROR,
1287 : (errcode(ERRCODE_DATATYPE_MISMATCH),
1288 : errmsg("column \"%s\" is of type %s"
1289 : " but default expression is of type %s",
1290 : NameStr(att_tup->attname),
1291 : format_type_be(atttype),
1292 : format_type_be(exprtype)),
1293 : errhint("You will need to rewrite or cast the expression.")));
1294 :
1295 148688 : return expr;
1296 : }
1297 :
1298 :
1299 : /* Does VALUES RTE contain any SetToDefault items? */
1300 : static bool
1301 4446 : searchForDefault(RangeTblEntry *rte)
1302 : {
1303 : ListCell *lc;
1304 :
1305 18378 : foreach(lc, rte->values_lists)
1306 : {
1307 14196 : List *sublist = (List *) lfirst(lc);
1308 : ListCell *lc2;
1309 :
1310 41306 : foreach(lc2, sublist)
1311 : {
1312 27374 : Node *col = (Node *) lfirst(lc2);
1313 :
1314 27374 : if (IsA(col, SetToDefault))
1315 264 : return true;
1316 : }
1317 : }
1318 4182 : return false;
1319 : }
1320 :
1321 :
1322 : /*
1323 : * Search a VALUES RTE for columns that contain only SetToDefault items,
1324 : * returning a Bitmapset containing the attribute numbers of any such columns.
1325 : */
1326 : static Bitmapset *
1327 84 : findDefaultOnlyColumns(RangeTblEntry *rte)
1328 : {
1329 84 : Bitmapset *default_only_cols = NULL;
1330 : ListCell *lc;
1331 :
1332 150 : foreach(lc, rte->values_lists)
1333 : {
1334 126 : List *sublist = (List *) lfirst(lc);
1335 : ListCell *lc2;
1336 : int i;
1337 :
1338 126 : if (default_only_cols == NULL)
1339 : {
1340 : /* Populate the initial result bitmap from the first row */
1341 84 : i = 0;
1342 250 : foreach(lc2, sublist)
1343 : {
1344 166 : Node *col = (Node *) lfirst(lc2);
1345 :
1346 166 : i++;
1347 166 : if (IsA(col, SetToDefault))
1348 42 : default_only_cols = bms_add_member(default_only_cols, i);
1349 : }
1350 : }
1351 : else
1352 : {
1353 : /* Update the result bitmap from this next row */
1354 42 : i = 0;
1355 124 : foreach(lc2, sublist)
1356 : {
1357 82 : Node *col = (Node *) lfirst(lc2);
1358 :
1359 82 : i++;
1360 82 : if (!IsA(col, SetToDefault))
1361 58 : default_only_cols = bms_del_member(default_only_cols, i);
1362 : }
1363 : }
1364 :
1365 : /*
1366 : * If no column in the rows read so far contains only DEFAULT items,
1367 : * we are done.
1368 : */
1369 126 : if (bms_is_empty(default_only_cols))
1370 60 : break;
1371 : }
1372 :
1373 84 : return default_only_cols;
1374 : }
1375 :
1376 :
1377 : /*
1378 : * When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES
1379 : * lists), we have to replace any DEFAULT items in the VALUES lists with
1380 : * the appropriate default expressions. The other aspects of targetlist
1381 : * rewriting need be applied only to the query's targetlist proper.
1382 : *
1383 : * For an auto-updatable view, each DEFAULT item in the VALUES list is
1384 : * replaced with the default from the view, if it has one. Otherwise it is
1385 : * left untouched so that the underlying base relation's default can be
1386 : * applied instead (when we later recurse to here after rewriting the query
1387 : * to refer to the base relation instead of the view).
1388 : *
1389 : * For other types of relation, including rule- and trigger-updatable views,
1390 : * all DEFAULT items are replaced, and if the target relation doesn't have a
1391 : * default, the value is explicitly set to NULL.
1392 : *
1393 : * Also, if a DEFAULT item is found in a column mentioned in unused_cols,
1394 : * it is explicitly set to NULL. This happens for columns in the VALUES RTE
1395 : * whose corresponding targetlist entries have already been replaced with the
1396 : * relation's default expressions, so that any values in those columns of the
1397 : * VALUES RTE are no longer used. This can happen for identity and generated
1398 : * columns (if INSERT ... OVERRIDING USER VALUE is used, or all the values to
1399 : * be inserted are DEFAULT). In principle we could replace all entries in
1400 : * such a column with NULL, whether DEFAULT or not; but it doesn't seem worth
1401 : * the trouble.
1402 : *
1403 : * Note that we may have subscripted or field assignment targetlist entries,
1404 : * as well as more complex expressions from already-replaced DEFAULT items if
1405 : * we have recursed to here for an auto-updatable view. However, it ought to
1406 : * be impossible for such entries to have DEFAULTs assigned to them, except
1407 : * for unused columns, as described above --- we should only have to replace
1408 : * DEFAULT items for targetlist entries that contain simple Vars referencing
1409 : * the VALUES RTE, or which are no longer referred to by the targetlist.
1410 : *
1411 : * Returns true if all DEFAULT items were replaced, and false if some were
1412 : * left untouched.
1413 : */
1414 : static bool
1415 4446 : rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
1416 : Relation target_relation,
1417 : Bitmapset *unused_cols)
1418 : {
1419 : List *newValues;
1420 : ListCell *lc;
1421 : bool isAutoUpdatableView;
1422 : bool allReplaced;
1423 : int numattrs;
1424 : int *attrnos;
1425 :
1426 : /* Steps below are not sensible for non-INSERT queries */
1427 : Assert(parsetree->commandType == CMD_INSERT);
1428 : Assert(rte->rtekind == RTE_VALUES);
1429 :
1430 : /*
1431 : * Rebuilding all the lists is a pretty expensive proposition in a big
1432 : * VALUES list, and it's a waste of time if there aren't any DEFAULT
1433 : * placeholders. So first scan to see if there are any.
1434 : */
1435 4446 : if (!searchForDefault(rte))
1436 4182 : return true; /* nothing to do */
1437 :
1438 : /*
1439 : * Scan the targetlist for entries referring to the VALUES RTE, and note
1440 : * the target attributes. As noted above, we should only need to do this
1441 : * for targetlist entries containing simple Vars --- nothing else in the
1442 : * VALUES RTE should contain DEFAULT items (except possibly for unused
1443 : * columns), and we complain if such a thing does occur.
1444 : */
1445 264 : numattrs = list_length(linitial(rte->values_lists));
1446 264 : attrnos = (int *) palloc0(numattrs * sizeof(int));
1447 :
1448 1118 : foreach(lc, parsetree->targetList)
1449 : {
1450 854 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
1451 :
1452 854 : if (IsA(tle->expr, Var))
1453 : {
1454 718 : Var *var = (Var *) tle->expr;
1455 :
1456 718 : if (var->varno == rti)
1457 : {
1458 718 : int attrno = var->varattno;
1459 :
1460 : Assert(attrno >= 1 && attrno <= numattrs);
1461 718 : attrnos[attrno - 1] = tle->resno;
1462 : }
1463 : }
1464 : }
1465 :
1466 : /*
1467 : * Check if the target relation is an auto-updatable view, in which case
1468 : * unresolved defaults will be left untouched rather than being set to
1469 : * NULL.
1470 : */
1471 264 : isAutoUpdatableView = false;
1472 264 : if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
1473 90 : !view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
1474 : {
1475 : List *locks;
1476 : bool hasUpdate;
1477 : bool found;
1478 : ListCell *l;
1479 :
1480 : /* Look for an unconditional DO INSTEAD rule */
1481 78 : locks = matchLocks(CMD_INSERT, target_relation,
1482 : parsetree->resultRelation, parsetree, &hasUpdate);
1483 :
1484 78 : found = false;
1485 102 : foreach(l, locks)
1486 : {
1487 36 : RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
1488 :
1489 36 : if (rule_lock->isInstead &&
1490 12 : rule_lock->qual == NULL)
1491 : {
1492 12 : found = true;
1493 12 : break;
1494 : }
1495 : }
1496 :
1497 : /*
1498 : * If we didn't find an unconditional DO INSTEAD rule, assume that the
1499 : * view is auto-updatable. If it isn't, rewriteTargetView() will
1500 : * throw an error.
1501 : */
1502 78 : if (!found)
1503 66 : isAutoUpdatableView = true;
1504 : }
1505 :
1506 264 : newValues = NIL;
1507 264 : allReplaced = true;
1508 804 : foreach(lc, rte->values_lists)
1509 : {
1510 540 : List *sublist = (List *) lfirst(lc);
1511 540 : List *newList = NIL;
1512 : ListCell *lc2;
1513 : int i;
1514 :
1515 : Assert(list_length(sublist) == numattrs);
1516 :
1517 540 : i = 0;
1518 2210 : foreach(lc2, sublist)
1519 : {
1520 1670 : Node *col = (Node *) lfirst(lc2);
1521 1670 : int attrno = attrnos[i++];
1522 :
1523 1670 : if (IsA(col, SetToDefault))
1524 : {
1525 : Form_pg_attribute att_tup;
1526 : Node *new_expr;
1527 :
1528 : /*
1529 : * If this column isn't used, just replace the DEFAULT with
1530 : * NULL (attrno will be 0 in this case because the targetlist
1531 : * entry will have been replaced by the default expression).
1532 : */
1533 792 : if (bms_is_member(i, unused_cols))
1534 : {
1535 72 : SetToDefault *def = (SetToDefault *) col;
1536 :
1537 72 : newList = lappend(newList,
1538 72 : makeNullConst(def->typeId,
1539 : def->typeMod,
1540 : def->collation));
1541 72 : continue;
1542 : }
1543 :
1544 720 : if (attrno == 0)
1545 0 : elog(ERROR, "cannot set value in column %d to DEFAULT", i);
1546 : Assert(attrno > 0 && attrno <= target_relation->rd_att->natts);
1547 720 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
1548 :
1549 720 : if (!att_tup->attisdropped)
1550 720 : new_expr = build_column_default(target_relation, attrno);
1551 : else
1552 0 : new_expr = NULL; /* force a NULL if dropped */
1553 :
1554 : /*
1555 : * If there is no default (ie, default is effectively NULL),
1556 : * we've got to explicitly set the column to NULL, unless the
1557 : * target relation is an auto-updatable view.
1558 : */
1559 720 : if (!new_expr)
1560 : {
1561 330 : if (isAutoUpdatableView)
1562 : {
1563 : /* Leave the value untouched */
1564 126 : newList = lappend(newList, col);
1565 126 : allReplaced = false;
1566 126 : continue;
1567 : }
1568 :
1569 204 : new_expr = (Node *) makeConst(att_tup->atttypid,
1570 : -1,
1571 : att_tup->attcollation,
1572 204 : att_tup->attlen,
1573 : (Datum) 0,
1574 : true, /* isnull */
1575 204 : att_tup->attbyval);
1576 : /* this is to catch a NOT NULL domain constraint */
1577 204 : new_expr = coerce_to_domain(new_expr,
1578 : InvalidOid, -1,
1579 : att_tup->atttypid,
1580 : COERCION_IMPLICIT,
1581 : COERCE_IMPLICIT_CAST,
1582 : -1,
1583 : false);
1584 : }
1585 594 : newList = lappend(newList, new_expr);
1586 : }
1587 : else
1588 878 : newList = lappend(newList, col);
1589 : }
1590 540 : newValues = lappend(newValues, newList);
1591 : }
1592 264 : rte->values_lists = newValues;
1593 :
1594 264 : pfree(attrnos);
1595 :
1596 264 : return allReplaced;
1597 : }
1598 :
1599 : /*
1600 : * Mop up any remaining DEFAULT items in the given VALUES RTE by
1601 : * replacing them with NULL constants.
1602 : *
1603 : * This is used for the product queries generated by DO ALSO rules attached to
1604 : * an auto-updatable view. The action can't depend on the "target relation"
1605 : * since the product query might not have one (it needn't be an INSERT).
1606 : * Essentially, such queries are treated as being attached to a rule-updatable
1607 : * view.
1608 : */
1609 : static void
1610 24 : rewriteValuesRTEToNulls(Query *parsetree, RangeTblEntry *rte)
1611 : {
1612 : List *newValues;
1613 : ListCell *lc;
1614 :
1615 24 : newValues = NIL;
1616 72 : foreach(lc, rte->values_lists)
1617 : {
1618 48 : List *sublist = (List *) lfirst(lc);
1619 48 : List *newList = NIL;
1620 : ListCell *lc2;
1621 :
1622 204 : foreach(lc2, sublist)
1623 : {
1624 156 : Node *col = (Node *) lfirst(lc2);
1625 :
1626 156 : if (IsA(col, SetToDefault))
1627 : {
1628 66 : SetToDefault *def = (SetToDefault *) col;
1629 :
1630 66 : newList = lappend(newList, makeNullConst(def->typeId,
1631 : def->typeMod,
1632 : def->collation));
1633 : }
1634 : else
1635 90 : newList = lappend(newList, col);
1636 : }
1637 48 : newValues = lappend(newValues, newList);
1638 : }
1639 24 : rte->values_lists = newValues;
1640 24 : }
1641 :
1642 :
1643 : /*
1644 : * matchLocks -
1645 : * match a relation's list of locks and returns the matching rules
1646 : */
1647 : static List *
1648 93746 : matchLocks(CmdType event,
1649 : Relation relation,
1650 : int varno,
1651 : Query *parsetree,
1652 : bool *hasUpdate)
1653 : {
1654 93746 : RuleLock *rulelocks = relation->rd_rules;
1655 93746 : List *matching_locks = NIL;
1656 : int nlocks;
1657 : int i;
1658 :
1659 93746 : if (rulelocks == NULL)
1660 88290 : return NIL;
1661 :
1662 5456 : if (parsetree->commandType != CMD_SELECT)
1663 : {
1664 5456 : if (parsetree->resultRelation != varno)
1665 0 : return NIL;
1666 : }
1667 :
1668 5456 : nlocks = rulelocks->numLocks;
1669 :
1670 12502 : for (i = 0; i < nlocks; i++)
1671 : {
1672 7064 : RewriteRule *oneLock = rulelocks->rules[i];
1673 :
1674 7064 : if (oneLock->event == CMD_UPDATE)
1675 642 : *hasUpdate = true;
1676 :
1677 : /*
1678 : * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
1679 : * configured to not fire during the current session's replication
1680 : * role. ON SELECT rules will always be applied in order to keep views
1681 : * working even in LOCAL or REPLICA role.
1682 : */
1683 7064 : if (oneLock->event != CMD_SELECT)
1684 : {
1685 2646 : if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA)
1686 : {
1687 12 : if (oneLock->enabled == RULE_FIRES_ON_ORIGIN ||
1688 6 : oneLock->enabled == RULE_DISABLED)
1689 6 : continue;
1690 : }
1691 : else /* ORIGIN or LOCAL ROLE */
1692 : {
1693 2634 : if (oneLock->enabled == RULE_FIRES_ON_REPLICA ||
1694 2628 : oneLock->enabled == RULE_DISABLED)
1695 30 : continue;
1696 : }
1697 :
1698 : /* Non-SELECT rules are not supported for MERGE */
1699 2610 : if (parsetree->commandType == CMD_MERGE)
1700 18 : ereport(ERROR,
1701 : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1702 : errmsg("cannot execute MERGE on relation \"%s\"",
1703 : RelationGetRelationName(relation)),
1704 : errdetail("MERGE is not supported for relations with rules."));
1705 : }
1706 :
1707 7010 : if (oneLock->event == event)
1708 : {
1709 1536 : if (parsetree->commandType != CMD_SELECT ||
1710 0 : rangeTableEntry_used((Node *) parsetree, varno, 0))
1711 1536 : matching_locks = lappend(matching_locks, oneLock);
1712 : }
1713 : }
1714 :
1715 5438 : return matching_locks;
1716 : }
1717 :
1718 :
1719 : /*
1720 : * ApplyRetrieveRule - expand an ON SELECT rule
1721 : */
1722 : static Query *
1723 13720 : ApplyRetrieveRule(Query *parsetree,
1724 : RewriteRule *rule,
1725 : int rt_index,
1726 : Relation relation,
1727 : List *activeRIRs)
1728 : {
1729 : Query *rule_action;
1730 : RangeTblEntry *rte;
1731 : RowMarkClause *rc;
1732 : int numCols;
1733 :
1734 13720 : if (list_length(rule->actions) != 1)
1735 0 : elog(ERROR, "expected just one rule action");
1736 13720 : if (rule->qual != NULL)
1737 0 : elog(ERROR, "cannot handle qualified ON SELECT rule");
1738 :
1739 : /* Check if the expansion of non-system views are restricted */
1740 13720 : if (unlikely((restrict_nonsystem_relation_kind & RESTRICT_RELKIND_VIEW) != 0 &&
1741 : RelationGetRelid(relation) >= FirstNormalObjectId))
1742 6 : ereport(ERROR,
1743 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1744 : errmsg("access to non-system view \"%s\" is restricted",
1745 : RelationGetRelationName(relation))));
1746 :
1747 13714 : if (rt_index == parsetree->resultRelation)
1748 : {
1749 : /*
1750 : * We have a view as the result relation of the query, and it wasn't
1751 : * rewritten by any rule. This case is supported if there is an
1752 : * INSTEAD OF trigger that will trap attempts to insert/update/delete
1753 : * view rows. The executor will check that; for the moment just plow
1754 : * ahead. We have two cases:
1755 : *
1756 : * For INSERT, we needn't do anything. The unmodified RTE will serve
1757 : * fine as the result relation.
1758 : *
1759 : * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
1760 : * source data for the operation. But we also need an unmodified RTE
1761 : * to serve as the target. So, copy the RTE and add the copy to the
1762 : * rangetable. Note that the copy does not get added to the jointree.
1763 : * Also note that there's a hack in fireRIRrules to avoid calling this
1764 : * function again when it arrives at the copied RTE.
1765 : */
1766 390 : if (parsetree->commandType == CMD_INSERT)
1767 120 : return parsetree;
1768 270 : else if (parsetree->commandType == CMD_UPDATE ||
1769 132 : parsetree->commandType == CMD_DELETE ||
1770 78 : parsetree->commandType == CMD_MERGE)
1771 270 : {
1772 : RangeTblEntry *newrte;
1773 : Var *var;
1774 : TargetEntry *tle;
1775 :
1776 270 : rte = rt_fetch(rt_index, parsetree->rtable);
1777 270 : newrte = copyObject(rte);
1778 270 : parsetree->rtable = lappend(parsetree->rtable, newrte);
1779 270 : parsetree->resultRelation = list_length(parsetree->rtable);
1780 : /* parsetree->mergeTargetRelation unchanged (use expanded view) */
1781 :
1782 : /*
1783 : * For the most part, Vars referencing the view should remain as
1784 : * they are, meaning that they implicitly represent OLD values.
1785 : * But in the RETURNING list if any, we want such Vars to
1786 : * represent NEW values, so change them to reference the new RTE.
1787 : *
1788 : * Since ChangeVarNodes scribbles on the tree in-place, copy the
1789 : * RETURNING list first for safety.
1790 : */
1791 270 : parsetree->returningList = copyObject(parsetree->returningList);
1792 270 : ChangeVarNodes((Node *) parsetree->returningList, rt_index,
1793 : parsetree->resultRelation, 0);
1794 :
1795 : /*
1796 : * To allow the executor to compute the original view row to pass
1797 : * to the INSTEAD OF trigger, we add a resjunk whole-row Var
1798 : * referencing the original RTE. This will later get expanded
1799 : * into a RowExpr computing all the OLD values of the view row.
1800 : */
1801 270 : var = makeWholeRowVar(rte, rt_index, 0, false);
1802 270 : tle = makeTargetEntry((Expr *) var,
1803 270 : list_length(parsetree->targetList) + 1,
1804 : pstrdup("wholerow"),
1805 : true);
1806 :
1807 270 : parsetree->targetList = lappend(parsetree->targetList, tle);
1808 :
1809 : /* Now, continue with expanding the original view RTE */
1810 : }
1811 : else
1812 0 : elog(ERROR, "unrecognized commandType: %d",
1813 : (int) parsetree->commandType);
1814 : }
1815 :
1816 : /*
1817 : * Check if there's a FOR [KEY] UPDATE/SHARE clause applying to this view.
1818 : *
1819 : * Note: we needn't explicitly consider any such clauses appearing in
1820 : * ancestor query levels; their effects have already been pushed down to
1821 : * here by markQueryForLocking, and will be reflected in "rc".
1822 : */
1823 13594 : rc = get_parse_rowmark(parsetree, rt_index);
1824 :
1825 : /*
1826 : * Make a modifiable copy of the view query, and acquire needed locks on
1827 : * the relations it mentions. Force at least RowShareLock for all such
1828 : * rels if there's a FOR [KEY] UPDATE/SHARE clause affecting this view.
1829 : */
1830 13594 : rule_action = copyObject(linitial(rule->actions));
1831 :
1832 13594 : AcquireRewriteLocks(rule_action, true, (rc != NULL));
1833 :
1834 : /*
1835 : * If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as
1836 : * implicit FOR [KEY] UPDATE/SHARE, the same as the parser would have done
1837 : * if the view's subquery had been written out explicitly.
1838 : */
1839 13594 : if (rc != NULL)
1840 96 : markQueryForLocking(rule_action, (Node *) rule_action->jointree,
1841 : rc->strength, rc->waitPolicy, true);
1842 :
1843 : /*
1844 : * Recursively expand any view references inside the view.
1845 : */
1846 13594 : rule_action = fireRIRrules(rule_action, activeRIRs);
1847 :
1848 : /*
1849 : * Make sure the query is marked as having row security if the view query
1850 : * does.
1851 : */
1852 13564 : parsetree->hasRowSecurity |= rule_action->hasRowSecurity;
1853 :
1854 : /*
1855 : * Now, plug the view query in as a subselect, converting the relation's
1856 : * original RTE to a subquery RTE.
1857 : */
1858 13564 : rte = rt_fetch(rt_index, parsetree->rtable);
1859 :
1860 13564 : rte->rtekind = RTE_SUBQUERY;
1861 13564 : rte->subquery = rule_action;
1862 13564 : rte->security_barrier = RelationIsSecurityView(relation);
1863 :
1864 : /*
1865 : * Clear fields that should not be set in a subquery RTE. Note that we
1866 : * leave the relid, relkind, rellockmode, and perminfoindex fields set, so
1867 : * that the view relation can be appropriately locked before execution and
1868 : * its permissions checked.
1869 : */
1870 13564 : rte->tablesample = NULL;
1871 13564 : rte->inh = false; /* must not be set for a subquery */
1872 :
1873 : /*
1874 : * Since we allow CREATE OR REPLACE VIEW to add columns to a view, the
1875 : * rule_action might emit more columns than we expected when the current
1876 : * query was parsed. Various places expect rte->eref->colnames to be
1877 : * consistent with the non-junk output columns of the subquery, so patch
1878 : * things up if necessary by adding some dummy column names.
1879 : */
1880 13564 : numCols = ExecCleanTargetListLength(rule_action->targetList);
1881 13582 : while (list_length(rte->eref->colnames) < numCols)
1882 : {
1883 18 : rte->eref->colnames = lappend(rte->eref->colnames,
1884 18 : makeString(pstrdup("?column?")));
1885 : }
1886 :
1887 13564 : return parsetree;
1888 : }
1889 :
1890 : /*
1891 : * Recursively mark all relations used by a view as FOR [KEY] UPDATE/SHARE.
1892 : *
1893 : * This may generate an invalid query, eg if some sub-query uses an
1894 : * aggregate. We leave it to the planner to detect that.
1895 : *
1896 : * NB: this must agree with the parser's transformLockingClause() routine.
1897 : * However, we used to have to avoid marking a view's OLD and NEW rels for
1898 : * updating, which motivated scanning the jointree to determine which rels
1899 : * are used. Possibly that could now be simplified into just scanning the
1900 : * rangetable as the parser does.
1901 : */
1902 : static void
1903 192 : markQueryForLocking(Query *qry, Node *jtnode,
1904 : LockClauseStrength strength, LockWaitPolicy waitPolicy,
1905 : bool pushedDown)
1906 : {
1907 192 : if (jtnode == NULL)
1908 0 : return;
1909 192 : if (IsA(jtnode, RangeTblRef))
1910 : {
1911 96 : int rti = ((RangeTblRef *) jtnode)->rtindex;
1912 96 : RangeTblEntry *rte = rt_fetch(rti, qry->rtable);
1913 :
1914 96 : if (rte->rtekind == RTE_RELATION)
1915 : {
1916 : RTEPermissionInfo *perminfo;
1917 :
1918 96 : applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
1919 :
1920 96 : perminfo = getRTEPermissionInfo(qry->rteperminfos, rte);
1921 96 : perminfo->requiredPerms |= ACL_SELECT_FOR_UPDATE;
1922 : }
1923 0 : else if (rte->rtekind == RTE_SUBQUERY)
1924 : {
1925 0 : applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
1926 : /* FOR UPDATE/SHARE of subquery is propagated to subquery's rels */
1927 0 : markQueryForLocking(rte->subquery, (Node *) rte->subquery->jointree,
1928 : strength, waitPolicy, true);
1929 : }
1930 : /* other RTE types are unaffected by FOR UPDATE */
1931 : }
1932 96 : else if (IsA(jtnode, FromExpr))
1933 : {
1934 96 : FromExpr *f = (FromExpr *) jtnode;
1935 : ListCell *l;
1936 :
1937 192 : foreach(l, f->fromlist)
1938 96 : markQueryForLocking(qry, lfirst(l), strength, waitPolicy, pushedDown);
1939 : }
1940 0 : else if (IsA(jtnode, JoinExpr))
1941 : {
1942 0 : JoinExpr *j = (JoinExpr *) jtnode;
1943 :
1944 0 : markQueryForLocking(qry, j->larg, strength, waitPolicy, pushedDown);
1945 0 : markQueryForLocking(qry, j->rarg, strength, waitPolicy, pushedDown);
1946 : }
1947 : else
1948 0 : elog(ERROR, "unrecognized node type: %d",
1949 : (int) nodeTag(jtnode));
1950 : }
1951 :
1952 :
1953 : /*
1954 : * fireRIRonSubLink -
1955 : * Apply fireRIRrules() to each SubLink (subselect in expression) found
1956 : * in the given tree.
1957 : *
1958 : * NOTE: although this has the form of a walker, we cheat and modify the
1959 : * SubLink nodes in-place. It is caller's responsibility to ensure that
1960 : * no unwanted side-effects occur!
1961 : *
1962 : * This is unlike most of the other routines that recurse into subselects,
1963 : * because we must take control at the SubLink node in order to replace
1964 : * the SubLink's subselect link with the possibly-rewritten subquery.
1965 : */
1966 : static bool
1967 2275554 : fireRIRonSubLink(Node *node, fireRIRonSubLink_context *context)
1968 : {
1969 2275554 : if (node == NULL)
1970 463354 : return false;
1971 1812200 : if (IsA(node, SubLink))
1972 : {
1973 39872 : SubLink *sub = (SubLink *) node;
1974 :
1975 : /* Do what we came for */
1976 39872 : sub->subselect = (Node *) fireRIRrules((Query *) sub->subselect,
1977 : context->activeRIRs);
1978 :
1979 : /*
1980 : * Remember if any of the sublinks have row security.
1981 : */
1982 39800 : context->hasRowSecurity |= ((Query *) sub->subselect)->hasRowSecurity;
1983 :
1984 : /* Fall through to process lefthand args of SubLink */
1985 : }
1986 :
1987 : /*
1988 : * Do NOT recurse into Query nodes, because fireRIRrules already processed
1989 : * subselects of subselects for us.
1990 : */
1991 1812128 : return expression_tree_walker(node, fireRIRonSubLink,
1992 : (void *) context);
1993 : }
1994 :
1995 :
1996 : /*
1997 : * fireRIRrules -
1998 : * Apply all RIR rules on each rangetable entry in the given query
1999 : *
2000 : * activeRIRs is a list of the OIDs of views we're already processing RIR
2001 : * rules for, used to detect/reject recursion.
2002 : */
2003 : static Query *
2004 537612 : fireRIRrules(Query *parsetree, List *activeRIRs)
2005 : {
2006 537612 : int origResultRelation = parsetree->resultRelation;
2007 : int rt_index;
2008 : ListCell *lc;
2009 :
2010 : /*
2011 : * Expand SEARCH and CYCLE clauses in CTEs.
2012 : *
2013 : * This is just a convenient place to do this, since we are already
2014 : * looking at each Query.
2015 : */
2016 541042 : foreach(lc, parsetree->cteList)
2017 : {
2018 3436 : CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc);
2019 :
2020 3436 : if (cte->search_clause || cte->cycle_clause)
2021 : {
2022 144 : cte = rewriteSearchAndCycle(cte);
2023 138 : lfirst(lc) = cte;
2024 : }
2025 : }
2026 :
2027 : /*
2028 : * don't try to convert this into a foreach loop, because rtable list can
2029 : * get changed each time through...
2030 : */
2031 537606 : rt_index = 0;
2032 1146538 : while (rt_index < list_length(parsetree->rtable))
2033 : {
2034 : RangeTblEntry *rte;
2035 : Relation rel;
2036 : List *locks;
2037 : RuleLock *rules;
2038 : RewriteRule *rule;
2039 : int i;
2040 :
2041 608968 : ++rt_index;
2042 :
2043 608968 : rte = rt_fetch(rt_index, parsetree->rtable);
2044 :
2045 : /*
2046 : * A subquery RTE can't have associated rules, so there's nothing to
2047 : * do to this level of the query, but we must recurse into the
2048 : * subquery to expand any rule references in it.
2049 : */
2050 608968 : if (rte->rtekind == RTE_SUBQUERY)
2051 : {
2052 37388 : rte->subquery = fireRIRrules(rte->subquery, activeRIRs);
2053 :
2054 : /*
2055 : * While we are here, make sure the query is marked as having row
2056 : * security if any of its subqueries do.
2057 : */
2058 37388 : parsetree->hasRowSecurity |= rte->subquery->hasRowSecurity;
2059 :
2060 37388 : continue;
2061 : }
2062 :
2063 : /*
2064 : * Joins and other non-relation RTEs can be ignored completely.
2065 : */
2066 571580 : if (rte->rtekind != RTE_RELATION)
2067 138956 : continue;
2068 :
2069 : /*
2070 : * Always ignore RIR rules for materialized views referenced in
2071 : * queries. (This does not prevent refreshing MVs, since they aren't
2072 : * referenced in their own query definitions.)
2073 : *
2074 : * Note: in the future we might want to allow MVs to be conditionally
2075 : * expanded as if they were regular views, if they are not scannable.
2076 : * In that case this test would need to be postponed till after we've
2077 : * opened the rel, so that we could check its state.
2078 : */
2079 432624 : if (rte->relkind == RELKIND_MATVIEW)
2080 458 : continue;
2081 :
2082 : /*
2083 : * In INSERT ... ON CONFLICT, ignore the EXCLUDED pseudo-relation;
2084 : * even if it points to a view, we needn't expand it, and should not
2085 : * because we want the RTE to remain of RTE_RELATION type. Otherwise,
2086 : * it would get changed to RTE_SUBQUERY type, which is an
2087 : * untested/unsupported situation.
2088 : */
2089 432166 : if (parsetree->onConflict &&
2090 3516 : rt_index == parsetree->onConflict->exclRelIndex)
2091 1258 : continue;
2092 :
2093 : /*
2094 : * If the table is not referenced in the query, then we ignore it.
2095 : * This prevents infinite expansion loop due to new rtable entries
2096 : * inserted by expansion of a rule. A table is referenced if it is
2097 : * part of the join set (a source table), or is referenced by any Var
2098 : * nodes, or is the result table.
2099 : */
2100 430908 : if (rt_index != parsetree->resultRelation &&
2101 341208 : !rangeTableEntry_used((Node *) parsetree, rt_index, 0))
2102 7052 : continue;
2103 :
2104 : /*
2105 : * Also, if this is a new result relation introduced by
2106 : * ApplyRetrieveRule, we don't want to do anything more with it.
2107 : */
2108 423856 : if (rt_index == parsetree->resultRelation &&
2109 : rt_index != origResultRelation)
2110 270 : continue;
2111 :
2112 : /*
2113 : * We can use NoLock here since either the parser or
2114 : * AcquireRewriteLocks should have locked the rel already.
2115 : */
2116 423586 : rel = table_open(rte->relid, NoLock);
2117 :
2118 : /*
2119 : * Collect the RIR rules that we must apply
2120 : */
2121 423586 : rules = rel->rd_rules;
2122 423586 : if (rules != NULL)
2123 : {
2124 14938 : locks = NIL;
2125 32678 : for (i = 0; i < rules->numLocks; i++)
2126 : {
2127 17740 : rule = rules->rules[i];
2128 17740 : if (rule->event != CMD_SELECT)
2129 4020 : continue;
2130 :
2131 13720 : locks = lappend(locks, rule);
2132 : }
2133 :
2134 : /*
2135 : * If we found any, apply them --- but first check for recursion!
2136 : */
2137 14938 : if (locks != NIL)
2138 : {
2139 : ListCell *l;
2140 :
2141 13720 : if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
2142 0 : ereport(ERROR,
2143 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2144 : errmsg("infinite recursion detected in rules for relation \"%s\"",
2145 : RelationGetRelationName(rel))));
2146 13720 : activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
2147 :
2148 27404 : foreach(l, locks)
2149 : {
2150 13720 : rule = lfirst(l);
2151 :
2152 13720 : parsetree = ApplyRetrieveRule(parsetree,
2153 : rule,
2154 : rt_index,
2155 : rel,
2156 : activeRIRs);
2157 : }
2158 :
2159 13684 : activeRIRs = list_delete_last(activeRIRs);
2160 : }
2161 : }
2162 :
2163 423550 : table_close(rel, NoLock);
2164 : }
2165 :
2166 : /* Recurse into subqueries in WITH */
2167 541000 : foreach(lc, parsetree->cteList)
2168 : {
2169 3430 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
2170 :
2171 3430 : cte->ctequery = (Node *)
2172 3430 : fireRIRrules((Query *) cte->ctequery, activeRIRs);
2173 :
2174 : /*
2175 : * While we are here, make sure the query is marked as having row
2176 : * security if any of its CTEs do.
2177 : */
2178 3430 : parsetree->hasRowSecurity |= ((Query *) cte->ctequery)->hasRowSecurity;
2179 : }
2180 :
2181 : /*
2182 : * Recurse into sublink subqueries, too. But we already did the ones in
2183 : * the rtable and cteList.
2184 : */
2185 537570 : if (parsetree->hasSubLinks)
2186 : {
2187 : fireRIRonSubLink_context context;
2188 :
2189 31658 : context.activeRIRs = activeRIRs;
2190 31658 : context.hasRowSecurity = false;
2191 :
2192 31658 : query_tree_walker(parsetree, fireRIRonSubLink, (void *) &context,
2193 : QTW_IGNORE_RC_SUBQUERIES);
2194 :
2195 : /*
2196 : * Make sure the query is marked as having row security if any of its
2197 : * sublinks do.
2198 : */
2199 31658 : parsetree->hasRowSecurity |= context.hasRowSecurity;
2200 : }
2201 :
2202 : /*
2203 : * Apply any row-level security policies. We do this last because it
2204 : * requires special recursion detection if the new quals have sublink
2205 : * subqueries, and if we did it in the loop above query_tree_walker would
2206 : * then recurse into those quals a second time.
2207 : */
2208 537570 : rt_index = 0;
2209 1146340 : foreach(lc, parsetree->rtable)
2210 : {
2211 608932 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
2212 : Relation rel;
2213 : List *securityQuals;
2214 : List *withCheckOptions;
2215 : bool hasRowSecurity;
2216 : bool hasSubLinks;
2217 :
2218 608932 : ++rt_index;
2219 :
2220 : /* Only normal relations can have RLS policies */
2221 608932 : if (rte->rtekind != RTE_RELATION ||
2222 419024 : (rte->relkind != RELKIND_RELATION &&
2223 25426 : rte->relkind != RELKIND_PARTITIONED_TABLE))
2224 198392 : continue;
2225 :
2226 410540 : rel = table_open(rte->relid, NoLock);
2227 :
2228 : /*
2229 : * Fetch any new security quals that must be applied to this RTE.
2230 : */
2231 410540 : get_row_security_policies(parsetree, rte, rt_index,
2232 : &securityQuals, &withCheckOptions,
2233 : &hasRowSecurity, &hasSubLinks);
2234 :
2235 410492 : if (securityQuals != NIL || withCheckOptions != NIL)
2236 : {
2237 2682 : if (hasSubLinks)
2238 : {
2239 : acquireLocksOnSubLinks_context context;
2240 : fireRIRonSubLink_context fire_context;
2241 :
2242 : /*
2243 : * Recursively process the new quals, checking for infinite
2244 : * recursion.
2245 : */
2246 660 : if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
2247 42 : ereport(ERROR,
2248 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2249 : errmsg("infinite recursion detected in policy for relation \"%s\"",
2250 : RelationGetRelationName(rel))));
2251 :
2252 618 : activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
2253 :
2254 : /*
2255 : * get_row_security_policies just passed back securityQuals
2256 : * and/or withCheckOptions, and there were SubLinks, make sure
2257 : * we lock any relations which are referenced.
2258 : *
2259 : * These locks would normally be acquired by the parser, but
2260 : * securityQuals and withCheckOptions are added post-parsing.
2261 : */
2262 618 : context.for_execute = true;
2263 618 : (void) acquireLocksOnSubLinks((Node *) securityQuals, &context);
2264 618 : (void) acquireLocksOnSubLinks((Node *) withCheckOptions,
2265 : &context);
2266 :
2267 : /*
2268 : * Now that we have the locks on anything added by
2269 : * get_row_security_policies, fire any RIR rules for them.
2270 : */
2271 618 : fire_context.activeRIRs = activeRIRs;
2272 618 : fire_context.hasRowSecurity = false;
2273 :
2274 618 : expression_tree_walker((Node *) securityQuals,
2275 : fireRIRonSubLink, (void *) &fire_context);
2276 :
2277 552 : expression_tree_walker((Node *) withCheckOptions,
2278 : fireRIRonSubLink, (void *) &fire_context);
2279 :
2280 : /*
2281 : * We can ignore the value of fire_context.hasRowSecurity
2282 : * since we only reach this code in cases where hasRowSecurity
2283 : * is already true.
2284 : */
2285 : Assert(hasRowSecurity);
2286 :
2287 546 : activeRIRs = list_delete_last(activeRIRs);
2288 : }
2289 :
2290 : /*
2291 : * Add the new security barrier quals to the start of the RTE's
2292 : * list so that they get applied before any existing barrier quals
2293 : * (which would have come from a security-barrier view, and should
2294 : * get lower priority than RLS conditions on the table itself).
2295 : */
2296 5136 : rte->securityQuals = list_concat(securityQuals,
2297 2568 : rte->securityQuals);
2298 :
2299 2568 : parsetree->withCheckOptions = list_concat(withCheckOptions,
2300 2568 : parsetree->withCheckOptions);
2301 : }
2302 :
2303 : /*
2304 : * Make sure the query is marked correctly if row-level security
2305 : * applies, or if the new quals had sublinks.
2306 : */
2307 410378 : if (hasRowSecurity)
2308 3130 : parsetree->hasRowSecurity = true;
2309 410378 : if (hasSubLinks)
2310 546 : parsetree->hasSubLinks = true;
2311 :
2312 410378 : table_close(rel, NoLock);
2313 : }
2314 :
2315 537408 : return parsetree;
2316 : }
2317 :
2318 :
2319 : /*
2320 : * Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its
2321 : * qualification. This is used to generate suitable "else clauses" for
2322 : * conditional INSTEAD rules. (Unfortunately we must use "x IS NOT TRUE",
2323 : * not just "NOT x" which the planner is much smarter about, else we will
2324 : * do the wrong thing when the qual evaluates to NULL.)
2325 : *
2326 : * The rule_qual may contain references to OLD or NEW. OLD references are
2327 : * replaced by references to the specified rt_index (the relation that the
2328 : * rule applies to). NEW references are only possible for INSERT and UPDATE
2329 : * queries on the relation itself, and so they should be replaced by copies
2330 : * of the related entries in the query's own targetlist.
2331 : */
2332 : static Query *
2333 444 : CopyAndAddInvertedQual(Query *parsetree,
2334 : Node *rule_qual,
2335 : int rt_index,
2336 : CmdType event)
2337 : {
2338 : /* Don't scribble on the passed qual (it's in the relcache!) */
2339 444 : Node *new_qual = copyObject(rule_qual);
2340 : acquireLocksOnSubLinks_context context;
2341 :
2342 444 : context.for_execute = true;
2343 :
2344 : /*
2345 : * In case there are subqueries in the qual, acquire necessary locks and
2346 : * fix any deleted JOIN RTE entries. (This is somewhat redundant with
2347 : * rewriteRuleAction, but not entirely ... consider restructuring so that
2348 : * we only need to process the qual this way once.)
2349 : */
2350 444 : (void) acquireLocksOnSubLinks(new_qual, &context);
2351 :
2352 : /* Fix references to OLD */
2353 444 : ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
2354 : /* Fix references to NEW */
2355 444 : if (event == CMD_INSERT || event == CMD_UPDATE)
2356 864 : new_qual = ReplaceVarsFromTargetList(new_qual,
2357 : PRS2_NEW_VARNO,
2358 : 0,
2359 432 : rt_fetch(rt_index,
2360 : parsetree->rtable),
2361 : parsetree->targetList,
2362 : (event == CMD_UPDATE) ?
2363 : REPLACEVARS_CHANGE_VARNO :
2364 : REPLACEVARS_SUBSTITUTE_NULL,
2365 : rt_index,
2366 : &parsetree->hasSubLinks);
2367 : /* And attach the fixed qual */
2368 444 : AddInvertedQual(parsetree, new_qual);
2369 :
2370 444 : return parsetree;
2371 : }
2372 :
2373 :
2374 : /*
2375 : * fireRules -
2376 : * Iterate through rule locks applying rules.
2377 : *
2378 : * Input arguments:
2379 : * parsetree - original query
2380 : * rt_index - RT index of result relation in original query
2381 : * event - type of rule event
2382 : * locks - list of rules to fire
2383 : * Output arguments:
2384 : * *instead_flag - set true if any unqualified INSTEAD rule is found
2385 : * (must be initialized to false)
2386 : * *returning_flag - set true if we rewrite RETURNING clause in any rule
2387 : * (must be initialized to false)
2388 : * *qual_product - filled with modified original query if any qualified
2389 : * INSTEAD rule is found (must be initialized to NULL)
2390 : * Return value:
2391 : * list of rule actions adjusted for use with this query
2392 : *
2393 : * Qualified INSTEAD rules generate their action with the qualification
2394 : * condition added. They also generate a modified version of the original
2395 : * query with the negated qualification added, so that it will run only for
2396 : * rows that the qualified action doesn't act on. (If there are multiple
2397 : * qualified INSTEAD rules, we AND all the negated quals onto a single
2398 : * modified original query.) We won't execute the original, unmodified
2399 : * query if we find either qualified or unqualified INSTEAD rules. If
2400 : * we find both, the modified original query is discarded too.
2401 : */
2402 : static List *
2403 93650 : fireRules(Query *parsetree,
2404 : int rt_index,
2405 : CmdType event,
2406 : List *locks,
2407 : bool *instead_flag,
2408 : bool *returning_flag,
2409 : Query **qual_product)
2410 : {
2411 93650 : List *results = NIL;
2412 : ListCell *l;
2413 :
2414 95144 : foreach(l, locks)
2415 : {
2416 1500 : RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
2417 1500 : Node *event_qual = rule_lock->qual;
2418 1500 : List *actions = rule_lock->actions;
2419 : QuerySource qsrc;
2420 : ListCell *r;
2421 :
2422 : /* Determine correct QuerySource value for actions */
2423 1500 : if (rule_lock->isInstead)
2424 : {
2425 1116 : if (event_qual != NULL)
2426 450 : qsrc = QSRC_QUAL_INSTEAD_RULE;
2427 : else
2428 : {
2429 666 : qsrc = QSRC_INSTEAD_RULE;
2430 666 : *instead_flag = true; /* report unqualified INSTEAD */
2431 : }
2432 : }
2433 : else
2434 384 : qsrc = QSRC_NON_INSTEAD_RULE;
2435 :
2436 1500 : if (qsrc == QSRC_QUAL_INSTEAD_RULE)
2437 : {
2438 : /*
2439 : * If there are INSTEAD rules with qualifications, the original
2440 : * query is still performed. But all the negated rule
2441 : * qualifications of the INSTEAD rules are added so it does its
2442 : * actions only in cases where the rule quals of all INSTEAD rules
2443 : * are false. Think of it as the default action in a case. We save
2444 : * this in *qual_product so RewriteQuery() can add it to the query
2445 : * list after we mangled it up enough.
2446 : *
2447 : * If we have already found an unqualified INSTEAD rule, then
2448 : * *qual_product won't be used, so don't bother building it.
2449 : */
2450 450 : if (!*instead_flag)
2451 : {
2452 444 : if (*qual_product == NULL)
2453 360 : *qual_product = copyObject(parsetree);
2454 444 : *qual_product = CopyAndAddInvertedQual(*qual_product,
2455 : event_qual,
2456 : rt_index,
2457 : event);
2458 : }
2459 : }
2460 :
2461 : /* Now process the rule's actions and add them to the result list */
2462 3048 : foreach(r, actions)
2463 : {
2464 1554 : Query *rule_action = lfirst(r);
2465 :
2466 1554 : if (rule_action->commandType == CMD_NOTHING)
2467 210 : continue;
2468 :
2469 1344 : rule_action = rewriteRuleAction(parsetree, rule_action,
2470 : event_qual, rt_index, event,
2471 : returning_flag);
2472 :
2473 1338 : rule_action->querySource = qsrc;
2474 1338 : rule_action->canSetTag = false; /* might change later */
2475 :
2476 1338 : results = lappend(results, rule_action);
2477 : }
2478 : }
2479 :
2480 93644 : return results;
2481 : }
2482 :
2483 :
2484 : /*
2485 : * get_view_query - get the Query from a view's _RETURN rule.
2486 : *
2487 : * Caller should have verified that the relation is a view, and therefore
2488 : * we should find an ON SELECT action.
2489 : *
2490 : * Note that the pointer returned is into the relcache and therefore must
2491 : * be treated as read-only to the caller and not modified or scribbled on.
2492 : */
2493 : Query *
2494 5614 : get_view_query(Relation view)
2495 : {
2496 : int i;
2497 :
2498 : Assert(view->rd_rel->relkind == RELKIND_VIEW);
2499 :
2500 5614 : for (i = 0; i < view->rd_rules->numLocks; i++)
2501 : {
2502 5614 : RewriteRule *rule = view->rd_rules->rules[i];
2503 :
2504 5614 : if (rule->event == CMD_SELECT)
2505 : {
2506 : /* A _RETURN rule should have only one action */
2507 5614 : if (list_length(rule->actions) != 1)
2508 0 : elog(ERROR, "invalid _RETURN rule action specification");
2509 :
2510 5614 : return (Query *) linitial(rule->actions);
2511 : }
2512 : }
2513 :
2514 0 : elog(ERROR, "failed to find _RETURN rule for view");
2515 : return NULL; /* keep compiler quiet */
2516 : }
2517 :
2518 :
2519 : /*
2520 : * view_has_instead_trigger - does view have an INSTEAD OF trigger for event?
2521 : *
2522 : * If it does, we don't want to treat it as auto-updatable. This test can't
2523 : * be folded into view_query_is_auto_updatable because it's not an error
2524 : * condition.
2525 : *
2526 : * For MERGE, this will return true if there is an INSTEAD OF trigger for
2527 : * every action in mergeActionList, and false if there are any actions that
2528 : * lack an INSTEAD OF trigger. If there are no data-modifying MERGE actions
2529 : * (only DO NOTHING actions), true is returned so that the view is treated
2530 : * as trigger-updatable, rather than erroring out if it's not auto-updatable.
2531 : */
2532 : bool
2533 5264 : view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
2534 : {
2535 5264 : TriggerDesc *trigDesc = view->trigdesc;
2536 :
2537 5264 : switch (event)
2538 : {
2539 1674 : case CMD_INSERT:
2540 1674 : if (trigDesc && trigDesc->trig_insert_instead_row)
2541 264 : return true;
2542 1410 : break;
2543 2006 : case CMD_UPDATE:
2544 2006 : if (trigDesc && trigDesc->trig_update_instead_row)
2545 282 : return true;
2546 1724 : break;
2547 582 : case CMD_DELETE:
2548 582 : if (trigDesc && trigDesc->trig_delete_instead_row)
2549 108 : return true;
2550 474 : break;
2551 1002 : case CMD_MERGE:
2552 1434 : foreach_node(MergeAction, action, mergeActionList)
2553 : {
2554 1122 : switch (action->commandType)
2555 : {
2556 180 : case CMD_INSERT:
2557 180 : if (!trigDesc || !trigDesc->trig_insert_instead_row)
2558 846 : return false;
2559 84 : break;
2560 744 : case CMD_UPDATE:
2561 744 : if (!trigDesc || !trigDesc->trig_update_instead_row)
2562 636 : return false;
2563 108 : break;
2564 138 : case CMD_DELETE:
2565 138 : if (!trigDesc || !trigDesc->trig_delete_instead_row)
2566 114 : return false;
2567 24 : break;
2568 60 : case CMD_NOTHING:
2569 : /* No trigger required */
2570 60 : break;
2571 0 : default:
2572 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
2573 : break;
2574 : }
2575 : }
2576 156 : return true; /* no actions without an INSTEAD OF trigger */
2577 0 : default:
2578 0 : elog(ERROR, "unrecognized CmdType: %d", (int) event);
2579 : break;
2580 : }
2581 3608 : return false;
2582 : }
2583 :
2584 :
2585 : /*
2586 : * view_col_is_auto_updatable - test whether the specified column of a view
2587 : * is auto-updatable. Returns NULL (if the column can be updated) or a message
2588 : * string giving the reason that it cannot be.
2589 : *
2590 : * The returned string has not been translated; if it is shown as an error
2591 : * message, the caller should apply _() to translate it.
2592 : *
2593 : * Note that the checks performed here are local to this view. We do not check
2594 : * whether the referenced column of the underlying base relation is updatable.
2595 : */
2596 : static const char *
2597 12978 : view_col_is_auto_updatable(RangeTblRef *rtr, TargetEntry *tle)
2598 : {
2599 12978 : Var *var = (Var *) tle->expr;
2600 :
2601 : /*
2602 : * For now, the only updatable columns we support are those that are Vars
2603 : * referring to user columns of the underlying base relation.
2604 : *
2605 : * The view targetlist may contain resjunk columns (e.g., a view defined
2606 : * like "SELECT * FROM t ORDER BY a+b" is auto-updatable) but such columns
2607 : * are not auto-updatable, and in fact should never appear in the outer
2608 : * query's targetlist.
2609 : */
2610 12978 : if (tle->resjunk)
2611 180 : return gettext_noop("Junk view columns are not updatable.");
2612 :
2613 12798 : if (!IsA(var, Var) ||
2614 11988 : var->varno != rtr->rtindex ||
2615 11988 : var->varlevelsup != 0)
2616 810 : return gettext_noop("View columns that are not columns of their base relation are not updatable.");
2617 :
2618 11988 : if (var->varattno < 0)
2619 402 : return gettext_noop("View columns that refer to system columns are not updatable.");
2620 :
2621 11586 : if (var->varattno == 0)
2622 0 : return gettext_noop("View columns that return whole-row references are not updatable.");
2623 :
2624 11586 : return NULL; /* the view column is updatable */
2625 : }
2626 :
2627 :
2628 : /*
2629 : * view_query_is_auto_updatable - test whether the specified view definition
2630 : * represents an auto-updatable view. Returns NULL (if the view can be updated)
2631 : * or a message string giving the reason that it cannot be.
2632 :
2633 : * The returned string has not been translated; if it is shown as an error
2634 : * message, the caller should apply _() to translate it.
2635 : *
2636 : * If check_cols is true, the view is required to have at least one updatable
2637 : * column (necessary for INSERT/UPDATE). Otherwise the view's columns are not
2638 : * checked for updatability. See also view_cols_are_auto_updatable.
2639 : *
2640 : * Note that the checks performed here are only based on the view definition.
2641 : * We do not check whether any base relations referred to by the view are
2642 : * updatable.
2643 : */
2644 : const char *
2645 5386 : view_query_is_auto_updatable(Query *viewquery, bool check_cols)
2646 : {
2647 : RangeTblRef *rtr;
2648 : RangeTblEntry *base_rte;
2649 :
2650 : /*----------
2651 : * Check if the view is simply updatable. According to SQL-92 this means:
2652 : * - No DISTINCT clause.
2653 : * - Each TLE is a column reference, and each column appears at most once.
2654 : * - FROM contains exactly one base relation.
2655 : * - No GROUP BY or HAVING clauses.
2656 : * - No set operations (UNION, INTERSECT or EXCEPT).
2657 : * - No sub-queries in the WHERE clause that reference the target table.
2658 : *
2659 : * We ignore that last restriction since it would be complex to enforce
2660 : * and there isn't any actual benefit to disallowing sub-queries. (The
2661 : * semantic issues that the standard is presumably concerned about don't
2662 : * arise in Postgres, since any such sub-query will not see any updates
2663 : * executed by the outer query anyway, thanks to MVCC snapshotting.)
2664 : *
2665 : * We also relax the second restriction by supporting part of SQL:1999
2666 : * feature T111, which allows for a mix of updatable and non-updatable
2667 : * columns, provided that an INSERT or UPDATE doesn't attempt to assign to
2668 : * a non-updatable column.
2669 : *
2670 : * In addition we impose these constraints, involving features that are
2671 : * not part of SQL-92:
2672 : * - No CTEs (WITH clauses).
2673 : * - No OFFSET or LIMIT clauses (this matches a SQL:2008 restriction).
2674 : * - No system columns (including whole-row references) in the tlist.
2675 : * - No window functions in the tlist.
2676 : * - No set-returning functions in the tlist.
2677 : *
2678 : * Note that we do these checks without recursively expanding the view.
2679 : * If the base relation is a view, we'll recursively deal with it later.
2680 : *----------
2681 : */
2682 5386 : if (viewquery->distinctClause != NIL)
2683 72 : return gettext_noop("Views containing DISTINCT are not automatically updatable.");
2684 :
2685 5314 : if (viewquery->groupClause != NIL || viewquery->groupingSets)
2686 36 : return gettext_noop("Views containing GROUP BY are not automatically updatable.");
2687 :
2688 5278 : if (viewquery->havingQual != NULL)
2689 30 : return gettext_noop("Views containing HAVING are not automatically updatable.");
2690 :
2691 5248 : if (viewquery->setOperations != NULL)
2692 36 : return gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not automatically updatable.");
2693 :
2694 5212 : if (viewquery->cteList != NIL)
2695 36 : return gettext_noop("Views containing WITH are not automatically updatable.");
2696 :
2697 5176 : if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL)
2698 504 : return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
2699 :
2700 : /*
2701 : * We must not allow window functions or set returning functions in the
2702 : * targetlist. Otherwise we might end up inserting them into the quals of
2703 : * the main query. We must also check for aggregates in the targetlist in
2704 : * case they appear without a GROUP BY.
2705 : *
2706 : * These restrictions ensure that each row of the view corresponds to a
2707 : * unique row in the underlying base relation.
2708 : */
2709 4672 : if (viewquery->hasAggs)
2710 30 : return gettext_noop("Views that return aggregate functions are not automatically updatable.");
2711 :
2712 4642 : if (viewquery->hasWindowFuncs)
2713 36 : return gettext_noop("Views that return window functions are not automatically updatable.");
2714 :
2715 4606 : if (viewquery->hasTargetSRFs)
2716 42 : return gettext_noop("Views that return set-returning functions are not automatically updatable.");
2717 :
2718 : /*
2719 : * The view query should select from a single base relation, which must be
2720 : * a table or another view.
2721 : */
2722 4564 : if (list_length(viewquery->jointree->fromlist) != 1)
2723 66 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2724 :
2725 4498 : rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
2726 4498 : if (!IsA(rtr, RangeTblRef))
2727 0 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2728 :
2729 4498 : base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
2730 4498 : if (base_rte->rtekind != RTE_RELATION ||
2731 4384 : (base_rte->relkind != RELKIND_RELATION &&
2732 1670 : base_rte->relkind != RELKIND_FOREIGN_TABLE &&
2733 1648 : base_rte->relkind != RELKIND_VIEW &&
2734 190 : base_rte->relkind != RELKIND_PARTITIONED_TABLE))
2735 156 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2736 :
2737 4342 : if (base_rte->tablesample)
2738 6 : return gettext_noop("Views containing TABLESAMPLE are not automatically updatable.");
2739 :
2740 : /*
2741 : * Check that the view has at least one updatable column. This is required
2742 : * for INSERT/UPDATE but not for DELETE.
2743 : */
2744 4336 : if (check_cols)
2745 : {
2746 : ListCell *cell;
2747 : bool found;
2748 :
2749 3016 : found = false;
2750 3202 : foreach(cell, viewquery->targetList)
2751 : {
2752 3202 : TargetEntry *tle = (TargetEntry *) lfirst(cell);
2753 :
2754 3202 : if (view_col_is_auto_updatable(rtr, tle) == NULL)
2755 : {
2756 3016 : found = true;
2757 3016 : break;
2758 : }
2759 : }
2760 :
2761 3016 : if (!found)
2762 0 : return gettext_noop("Views that have no updatable columns are not automatically updatable.");
2763 : }
2764 :
2765 4336 : return NULL; /* the view is updatable */
2766 : }
2767 :
2768 :
2769 : /*
2770 : * view_cols_are_auto_updatable - test whether all of the required columns of
2771 : * an auto-updatable view are actually updatable. Returns NULL (if all the
2772 : * required columns can be updated) or a message string giving the reason that
2773 : * they cannot be.
2774 : *
2775 : * The returned string has not been translated; if it is shown as an error
2776 : * message, the caller should apply _() to translate it.
2777 : *
2778 : * This should be used for INSERT/UPDATE to ensure that we don't attempt to
2779 : * assign to any non-updatable columns.
2780 : *
2781 : * Additionally it may be used to retrieve the set of updatable columns in the
2782 : * view, or if one or more of the required columns is not updatable, the name
2783 : * of the first offending non-updatable column.
2784 : *
2785 : * The caller must have already verified that this is an auto-updatable view
2786 : * using view_query_is_auto_updatable.
2787 : *
2788 : * Note that the checks performed here are only based on the view definition.
2789 : * We do not check whether the referenced columns of the base relation are
2790 : * updatable.
2791 : */
2792 : static const char *
2793 3836 : view_cols_are_auto_updatable(Query *viewquery,
2794 : Bitmapset *required_cols,
2795 : Bitmapset **updatable_cols,
2796 : char **non_updatable_col)
2797 : {
2798 : RangeTblRef *rtr;
2799 : AttrNumber col;
2800 : ListCell *cell;
2801 :
2802 : /*
2803 : * The caller should have verified that this view is auto-updatable and so
2804 : * there should be a single base relation.
2805 : */
2806 : Assert(list_length(viewquery->jointree->fromlist) == 1);
2807 3836 : rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
2808 :
2809 : /* Initialize the optional return values */
2810 3836 : if (updatable_cols != NULL)
2811 966 : *updatable_cols = NULL;
2812 3836 : if (non_updatable_col != NULL)
2813 2870 : *non_updatable_col = NULL;
2814 :
2815 : /* Test each view column for updatability */
2816 3836 : col = -FirstLowInvalidHeapAttributeNumber;
2817 13492 : foreach(cell, viewquery->targetList)
2818 : {
2819 9776 : TargetEntry *tle = (TargetEntry *) lfirst(cell);
2820 : const char *col_update_detail;
2821 :
2822 9776 : col++;
2823 9776 : col_update_detail = view_col_is_auto_updatable(rtr, tle);
2824 :
2825 9776 : if (col_update_detail == NULL)
2826 : {
2827 : /* The column is updatable */
2828 8570 : if (updatable_cols != NULL)
2829 1758 : *updatable_cols = bms_add_member(*updatable_cols, col);
2830 : }
2831 1206 : else if (bms_is_member(col, required_cols))
2832 : {
2833 : /* The required column is not updatable */
2834 120 : if (non_updatable_col != NULL)
2835 120 : *non_updatable_col = tle->resname;
2836 120 : return col_update_detail;
2837 : }
2838 : }
2839 :
2840 3716 : return NULL; /* all the required view columns are updatable */
2841 : }
2842 :
2843 :
2844 : /*
2845 : * relation_is_updatable - determine which update events the specified
2846 : * relation supports.
2847 : *
2848 : * Note that views may contain a mix of updatable and non-updatable columns.
2849 : * For a view to support INSERT/UPDATE it must have at least one updatable
2850 : * column, but there is no such restriction for DELETE. If include_cols is
2851 : * non-NULL, then only the specified columns are considered when testing for
2852 : * updatability.
2853 : *
2854 : * Unlike the preceding functions, this does recurse to look at a view's
2855 : * base relations, so it needs to detect recursion. To do that, we pass
2856 : * a list of currently-considered outer relations. External callers need
2857 : * only pass NIL.
2858 : *
2859 : * This is used for the information_schema views, which have separate concepts
2860 : * of "updatable" and "trigger updatable". A relation is "updatable" if it
2861 : * can be updated without the need for triggers (either because it has a
2862 : * suitable RULE, or because it is simple enough to be automatically updated).
2863 : * A relation is "trigger updatable" if it has a suitable INSTEAD OF trigger.
2864 : * The SQL standard regards this as not necessarily updatable, presumably
2865 : * because there is no way of knowing what the trigger will actually do.
2866 : * The information_schema views therefore call this function with
2867 : * include_triggers = false. However, other callers might only care whether
2868 : * data-modifying SQL will work, so they can pass include_triggers = true
2869 : * to have trigger updatability included in the result.
2870 : *
2871 : * The return value is a bitmask of rule event numbers indicating which of
2872 : * the INSERT, UPDATE and DELETE operations are supported. (We do it this way
2873 : * so that we can test for UPDATE plus DELETE support in a single call.)
2874 : */
2875 : int
2876 1956 : relation_is_updatable(Oid reloid,
2877 : List *outer_reloids,
2878 : bool include_triggers,
2879 : Bitmapset *include_cols)
2880 : {
2881 1956 : int events = 0;
2882 : Relation rel;
2883 : RuleLock *rulelocks;
2884 :
2885 : #define ALL_EVENTS ((1 << CMD_INSERT) | (1 << CMD_UPDATE) | (1 << CMD_DELETE))
2886 :
2887 : /* Since this function recurses, it could be driven to stack overflow */
2888 1956 : check_stack_depth();
2889 :
2890 1956 : rel = try_relation_open(reloid, AccessShareLock);
2891 :
2892 : /*
2893 : * If the relation doesn't exist, return zero rather than throwing an
2894 : * error. This is helpful since scanning an information_schema view under
2895 : * MVCC rules can result in referencing rels that have actually been
2896 : * deleted already.
2897 : */
2898 1956 : if (rel == NULL)
2899 0 : return 0;
2900 :
2901 : /* If we detect a recursive view, report that it is not updatable */
2902 1956 : if (list_member_oid(outer_reloids, RelationGetRelid(rel)))
2903 : {
2904 0 : relation_close(rel, AccessShareLock);
2905 0 : return 0;
2906 : }
2907 :
2908 : /* If the relation is a table, it is always updatable */
2909 1956 : if (rel->rd_rel->relkind == RELKIND_RELATION ||
2910 1956 : rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
2911 : {
2912 18 : relation_close(rel, AccessShareLock);
2913 18 : return ALL_EVENTS;
2914 : }
2915 :
2916 : /* Look for unconditional DO INSTEAD rules, and note supported events */
2917 1938 : rulelocks = rel->rd_rules;
2918 1938 : if (rulelocks != NULL)
2919 : {
2920 : int i;
2921 :
2922 4248 : for (i = 0; i < rulelocks->numLocks; i++)
2923 : {
2924 2310 : if (rulelocks->rules[i]->isInstead &&
2925 2298 : rulelocks->rules[i]->qual == NULL)
2926 : {
2927 2298 : events |= ((1 << rulelocks->rules[i]->event) & ALL_EVENTS);
2928 : }
2929 : }
2930 :
2931 : /* If we have rules for all events, we're done */
2932 1938 : if (events == ALL_EVENTS)
2933 : {
2934 60 : relation_close(rel, AccessShareLock);
2935 60 : return events;
2936 : }
2937 : }
2938 :
2939 : /* Similarly look for INSTEAD OF triggers, if they are to be included */
2940 1878 : if (include_triggers)
2941 : {
2942 0 : TriggerDesc *trigDesc = rel->trigdesc;
2943 :
2944 0 : if (trigDesc)
2945 : {
2946 0 : if (trigDesc->trig_insert_instead_row)
2947 0 : events |= (1 << CMD_INSERT);
2948 0 : if (trigDesc->trig_update_instead_row)
2949 0 : events |= (1 << CMD_UPDATE);
2950 0 : if (trigDesc->trig_delete_instead_row)
2951 0 : events |= (1 << CMD_DELETE);
2952 :
2953 : /* If we have triggers for all events, we're done */
2954 0 : if (events == ALL_EVENTS)
2955 : {
2956 0 : relation_close(rel, AccessShareLock);
2957 0 : return events;
2958 : }
2959 : }
2960 : }
2961 :
2962 : /* If this is a foreign table, check which update events it supports */
2963 1878 : if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
2964 : {
2965 0 : FdwRoutine *fdwroutine = GetFdwRoutineForRelation(rel, false);
2966 :
2967 0 : if (fdwroutine->IsForeignRelUpdatable != NULL)
2968 0 : events |= fdwroutine->IsForeignRelUpdatable(rel);
2969 : else
2970 : {
2971 : /* Assume presence of executor functions is sufficient */
2972 0 : if (fdwroutine->ExecForeignInsert != NULL)
2973 0 : events |= (1 << CMD_INSERT);
2974 0 : if (fdwroutine->ExecForeignUpdate != NULL)
2975 0 : events |= (1 << CMD_UPDATE);
2976 0 : if (fdwroutine->ExecForeignDelete != NULL)
2977 0 : events |= (1 << CMD_DELETE);
2978 : }
2979 :
2980 0 : relation_close(rel, AccessShareLock);
2981 0 : return events;
2982 : }
2983 :
2984 : /* Check if this is an automatically updatable view */
2985 1878 : if (rel->rd_rel->relkind == RELKIND_VIEW)
2986 : {
2987 1878 : Query *viewquery = get_view_query(rel);
2988 :
2989 1878 : if (view_query_is_auto_updatable(viewquery, false) == NULL)
2990 : {
2991 : Bitmapset *updatable_cols;
2992 : int auto_events;
2993 : RangeTblRef *rtr;
2994 : RangeTblEntry *base_rte;
2995 : Oid baseoid;
2996 :
2997 : /*
2998 : * Determine which of the view's columns are updatable. If there
2999 : * are none within the set of columns we are looking at, then the
3000 : * view doesn't support INSERT/UPDATE, but it may still support
3001 : * DELETE.
3002 : */
3003 966 : view_cols_are_auto_updatable(viewquery, NULL,
3004 : &updatable_cols, NULL);
3005 :
3006 966 : if (include_cols != NULL)
3007 498 : updatable_cols = bms_int_members(updatable_cols, include_cols);
3008 :
3009 966 : if (bms_is_empty(updatable_cols))
3010 102 : auto_events = (1 << CMD_DELETE); /* May support DELETE */
3011 : else
3012 864 : auto_events = ALL_EVENTS; /* May support all events */
3013 :
3014 : /*
3015 : * The base relation must also support these update commands.
3016 : * Tables are always updatable, but for any other kind of base
3017 : * relation we must do a recursive check limited to the columns
3018 : * referenced by the locally updatable columns in this view.
3019 : */
3020 966 : rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
3021 966 : base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
3022 : Assert(base_rte->rtekind == RTE_RELATION);
3023 :
3024 966 : if (base_rte->relkind != RELKIND_RELATION &&
3025 522 : base_rte->relkind != RELKIND_PARTITIONED_TABLE)
3026 : {
3027 492 : baseoid = base_rte->relid;
3028 492 : outer_reloids = lappend_oid(outer_reloids,
3029 : RelationGetRelid(rel));
3030 492 : include_cols = adjust_view_column_set(updatable_cols,
3031 : viewquery->targetList);
3032 492 : auto_events &= relation_is_updatable(baseoid,
3033 : outer_reloids,
3034 : include_triggers,
3035 : include_cols);
3036 492 : outer_reloids = list_delete_last(outer_reloids);
3037 : }
3038 966 : events |= auto_events;
3039 : }
3040 : }
3041 :
3042 : /* If we reach here, the relation may support some update commands */
3043 1878 : relation_close(rel, AccessShareLock);
3044 1878 : return events;
3045 : }
3046 :
3047 :
3048 : /*
3049 : * adjust_view_column_set - map a set of column numbers according to targetlist
3050 : *
3051 : * This is used with simply-updatable views to map column-permissions sets for
3052 : * the view columns onto the matching columns in the underlying base relation.
3053 : * Relevant entries in the targetlist must be plain Vars of the underlying
3054 : * relation (as per the checks above in view_query_is_auto_updatable).
3055 : */
3056 : static Bitmapset *
3057 6688 : adjust_view_column_set(Bitmapset *cols, List *targetlist)
3058 : {
3059 6688 : Bitmapset *result = NULL;
3060 : int col;
3061 :
3062 6688 : col = -1;
3063 11494 : while ((col = bms_next_member(cols, col)) >= 0)
3064 : {
3065 : /* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
3066 4806 : AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
3067 :
3068 4806 : if (attno == InvalidAttrNumber)
3069 : {
3070 : /*
3071 : * There's a whole-row reference to the view. For permissions
3072 : * purposes, treat it as a reference to each column available from
3073 : * the view. (We should *not* convert this to a whole-row
3074 : * reference to the base relation, since the view may not touch
3075 : * all columns of the base relation.)
3076 : */
3077 : ListCell *lc;
3078 :
3079 0 : foreach(lc, targetlist)
3080 : {
3081 0 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
3082 : Var *var;
3083 :
3084 0 : if (tle->resjunk)
3085 0 : continue;
3086 0 : var = castNode(Var, tle->expr);
3087 0 : result = bms_add_member(result,
3088 0 : var->varattno - FirstLowInvalidHeapAttributeNumber);
3089 : }
3090 : }
3091 : else
3092 : {
3093 : /*
3094 : * Views do not have system columns, so we do not expect to see
3095 : * any other system attnos here. If we do find one, the error
3096 : * case will apply.
3097 : */
3098 4806 : TargetEntry *tle = get_tle_by_resno(targetlist, attno);
3099 :
3100 4806 : if (tle != NULL && !tle->resjunk && IsA(tle->expr, Var))
3101 4806 : {
3102 4806 : Var *var = (Var *) tle->expr;
3103 :
3104 4806 : result = bms_add_member(result,
3105 4806 : var->varattno - FirstLowInvalidHeapAttributeNumber);
3106 : }
3107 : else
3108 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3109 : attno);
3110 : }
3111 : }
3112 :
3113 6688 : return result;
3114 : }
3115 :
3116 :
3117 : /*
3118 : * error_view_not_updatable -
3119 : * Report an error due to an attempt to update a non-updatable view.
3120 : *
3121 : * Generally this is expected to be called from the rewriter, with suitable
3122 : * error detail explaining why the view is not updatable. Note, however, that
3123 : * the executor also performs a just-in-case check that the target view is
3124 : * updatable. That check is expected to never fail, but if it does, it will
3125 : * call this function with NULL error detail --- see CheckValidResultRel().
3126 : *
3127 : * Note: for MERGE, at least one of the actions in mergeActionList is expected
3128 : * to lack a suitable INSTEAD OF trigger --- see view_has_instead_trigger().
3129 : */
3130 : void
3131 156 : error_view_not_updatable(Relation view,
3132 : CmdType command,
3133 : List *mergeActionList,
3134 : const char *detail)
3135 : {
3136 156 : TriggerDesc *trigDesc = view->trigdesc;
3137 :
3138 156 : switch (command)
3139 : {
3140 24 : case CMD_INSERT:
3141 24 : ereport(ERROR,
3142 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3143 : errmsg("cannot insert into view \"%s\"",
3144 : RelationGetRelationName(view)),
3145 : detail ? errdetail_internal("%s", _(detail)) : 0,
3146 : errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
3147 : break;
3148 54 : case CMD_UPDATE:
3149 54 : ereport(ERROR,
3150 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3151 : errmsg("cannot update view \"%s\"",
3152 : RelationGetRelationName(view)),
3153 : detail ? errdetail_internal("%s", _(detail)) : 0,
3154 : errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
3155 : break;
3156 48 : case CMD_DELETE:
3157 48 : ereport(ERROR,
3158 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3159 : errmsg("cannot delete from view \"%s\"",
3160 : RelationGetRelationName(view)),
3161 : detail ? errdetail_internal("%s", _(detail)) : 0,
3162 : errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
3163 : break;
3164 30 : case CMD_MERGE:
3165 :
3166 : /*
3167 : * Note that the error hints here differ from above, since MERGE
3168 : * doesn't support rules.
3169 : */
3170 36 : foreach_node(MergeAction, action, mergeActionList)
3171 : {
3172 36 : switch (action->commandType)
3173 : {
3174 12 : case CMD_INSERT:
3175 12 : if (!trigDesc || !trigDesc->trig_insert_instead_row)
3176 12 : ereport(ERROR,
3177 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3178 : errmsg("cannot insert into view \"%s\"",
3179 : RelationGetRelationName(view)),
3180 : detail ? errdetail_internal("%s", _(detail)) : 0,
3181 : errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
3182 0 : break;
3183 12 : case CMD_UPDATE:
3184 12 : if (!trigDesc || !trigDesc->trig_update_instead_row)
3185 6 : ereport(ERROR,
3186 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3187 : errmsg("cannot update view \"%s\"",
3188 : RelationGetRelationName(view)),
3189 : detail ? errdetail_internal("%s", _(detail)) : 0,
3190 : errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
3191 6 : break;
3192 12 : case CMD_DELETE:
3193 12 : if (!trigDesc || !trigDesc->trig_delete_instead_row)
3194 12 : ereport(ERROR,
3195 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3196 : errmsg("cannot delete from view \"%s\"",
3197 : RelationGetRelationName(view)),
3198 : detail ? errdetail_internal("%s", _(detail)) : 0,
3199 : errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
3200 0 : break;
3201 0 : case CMD_NOTHING:
3202 0 : break;
3203 0 : default:
3204 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
3205 : break;
3206 : }
3207 : }
3208 0 : break;
3209 0 : default:
3210 0 : elog(ERROR, "unrecognized CmdType: %d", (int) command);
3211 : break;
3212 : }
3213 0 : }
3214 :
3215 :
3216 : /*
3217 : * rewriteTargetView -
3218 : * Attempt to rewrite a query where the target relation is a view, so that
3219 : * the view's base relation becomes the target relation.
3220 : *
3221 : * Note that the base relation here may itself be a view, which may or may not
3222 : * have INSTEAD OF triggers or rules to handle the update. That is handled by
3223 : * the recursion in RewriteQuery.
3224 : */
3225 : static Query *
3226 3368 : rewriteTargetView(Query *parsetree, Relation view)
3227 : {
3228 : Query *viewquery;
3229 : bool insert_or_update;
3230 : const char *auto_update_detail;
3231 : RangeTblRef *rtr;
3232 : int base_rt_index;
3233 : int new_rt_index;
3234 : RangeTblEntry *base_rte;
3235 : RangeTblEntry *view_rte;
3236 : RangeTblEntry *new_rte;
3237 : RTEPermissionInfo *base_perminfo;
3238 : RTEPermissionInfo *view_perminfo;
3239 : RTEPermissionInfo *new_perminfo;
3240 : Relation base_rel;
3241 : List *view_targetlist;
3242 : ListCell *lc;
3243 :
3244 : /*
3245 : * Get the Query from the view's ON SELECT rule. We're going to munge the
3246 : * Query to change the view's base relation into the target relation,
3247 : * along with various other changes along the way, so we need to make a
3248 : * copy of it (get_view_query() returns a pointer into the relcache, so we
3249 : * have to treat it as read-only).
3250 : */
3251 3368 : viewquery = copyObject(get_view_query(view));
3252 :
3253 : /* Locate RTE and perminfo describing the view in the outer query */
3254 3368 : view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
3255 3368 : view_perminfo = getRTEPermissionInfo(parsetree->rteperminfos, view_rte);
3256 :
3257 : /*
3258 : * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE? If so,
3259 : * various additional checks on the view columns need to be applied, and
3260 : * any view CHECK OPTIONs need to be enforced.
3261 : */
3262 3368 : insert_or_update =
3263 5584 : (parsetree->commandType == CMD_INSERT ||
3264 2216 : parsetree->commandType == CMD_UPDATE);
3265 :
3266 3368 : if (parsetree->commandType == CMD_MERGE)
3267 : {
3268 1806 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3269 : {
3270 894 : if (action->commandType == CMD_INSERT ||
3271 810 : action->commandType == CMD_UPDATE)
3272 : {
3273 780 : insert_or_update = true;
3274 780 : break;
3275 : }
3276 : }
3277 : }
3278 :
3279 : /* Check if the expansion of non-system views are restricted */
3280 3368 : if (unlikely((restrict_nonsystem_relation_kind & RESTRICT_RELKIND_VIEW) != 0 &&
3281 : RelationGetRelid(view) >= FirstNormalObjectId))
3282 6 : ereport(ERROR,
3283 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3284 : errmsg("access to non-system view \"%s\" is restricted",
3285 : RelationGetRelationName(view))));
3286 :
3287 : /*
3288 : * The view must be updatable, else fail.
3289 : *
3290 : * If we are doing INSERT/UPDATE (or MERGE containing INSERT/UPDATE), we
3291 : * also check that there is at least one updatable column.
3292 : */
3293 : auto_update_detail =
3294 3362 : view_query_is_auto_updatable(viewquery, insert_or_update);
3295 :
3296 3362 : if (auto_update_detail)
3297 138 : error_view_not_updatable(view,
3298 : parsetree->commandType,
3299 : parsetree->mergeActionList,
3300 : auto_update_detail);
3301 :
3302 : /*
3303 : * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
3304 : * columns must all be updatable.
3305 : */
3306 3224 : if (insert_or_update)
3307 : {
3308 : Bitmapset *modified_cols;
3309 : char *non_updatable_col;
3310 :
3311 : /*
3312 : * Compute the set of modified columns as those listed in the result
3313 : * RTE's insertedCols and/or updatedCols sets plus those that are
3314 : * targets of the query's targetlist(s). We must consider the query's
3315 : * targetlist because rewriteTargetListIU may have added additional
3316 : * targetlist entries for view defaults, and these must also be
3317 : * updatable. But rewriteTargetListIU can also remove entries if they
3318 : * are DEFAULT markers and the column's default is NULL, so
3319 : * considering only the targetlist would also be wrong.
3320 : */
3321 2870 : modified_cols = bms_union(view_perminfo->insertedCols,
3322 2870 : view_perminfo->updatedCols);
3323 :
3324 6038 : foreach(lc, parsetree->targetList)
3325 : {
3326 3168 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3327 :
3328 3168 : if (!tle->resjunk)
3329 3168 : modified_cols = bms_add_member(modified_cols,
3330 3168 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3331 : }
3332 :
3333 2870 : if (parsetree->onConflict)
3334 : {
3335 336 : foreach(lc, parsetree->onConflict->onConflictSet)
3336 : {
3337 156 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3338 :
3339 156 : if (!tle->resjunk)
3340 156 : modified_cols = bms_add_member(modified_cols,
3341 156 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3342 : }
3343 : }
3344 :
3345 6694 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3346 : {
3347 954 : if (action->commandType == CMD_INSERT ||
3348 768 : action->commandType == CMD_UPDATE)
3349 : {
3350 2826 : foreach_node(TargetEntry, tle, action->targetList)
3351 : {
3352 1062 : if (!tle->resjunk)
3353 1062 : modified_cols = bms_add_member(modified_cols,
3354 1062 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3355 : }
3356 : }
3357 : }
3358 :
3359 2870 : auto_update_detail = view_cols_are_auto_updatable(viewquery,
3360 : modified_cols,
3361 : NULL,
3362 : &non_updatable_col);
3363 2870 : if (auto_update_detail)
3364 : {
3365 : /*
3366 : * This is a different error, caused by an attempt to update a
3367 : * non-updatable column in an otherwise updatable view.
3368 : */
3369 120 : switch (parsetree->commandType)
3370 : {
3371 72 : case CMD_INSERT:
3372 72 : ereport(ERROR,
3373 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3374 : errmsg("cannot insert into column \"%s\" of view \"%s\"",
3375 : non_updatable_col,
3376 : RelationGetRelationName(view)),
3377 : errdetail_internal("%s", _(auto_update_detail))));
3378 : break;
3379 42 : case CMD_UPDATE:
3380 42 : ereport(ERROR,
3381 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3382 : errmsg("cannot update column \"%s\" of view \"%s\"",
3383 : non_updatable_col,
3384 : RelationGetRelationName(view)),
3385 : errdetail_internal("%s", _(auto_update_detail))));
3386 : break;
3387 6 : case CMD_MERGE:
3388 6 : ereport(ERROR,
3389 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3390 : errmsg("cannot merge into column \"%s\" of view \"%s\"",
3391 : non_updatable_col,
3392 : RelationGetRelationName(view)),
3393 : errdetail_internal("%s", _(auto_update_detail))));
3394 : break;
3395 0 : default:
3396 0 : elog(ERROR, "unrecognized CmdType: %d",
3397 : (int) parsetree->commandType);
3398 : break;
3399 : }
3400 2750 : }
3401 : }
3402 :
3403 : /*
3404 : * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
3405 : * updatable view. The caller already checked that there isn't a full set
3406 : * of INSTEAD OF triggers, so this is to guard against having a partial
3407 : * set (mixing auto-update and trigger-update actions in a single command
3408 : * isn't supported).
3409 : */
3410 3104 : if (parsetree->commandType == CMD_MERGE)
3411 : {
3412 2604 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3413 : {
3414 1992 : if (action->commandType != CMD_NOTHING &&
3415 996 : view_has_instead_trigger(view, action->commandType, NIL))
3416 6 : ereport(ERROR,
3417 : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3418 : errmsg("cannot merge into view \"%s\"",
3419 : RelationGetRelationName(view)),
3420 : errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions but not all."),
3421 : errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
3422 : }
3423 : }
3424 :
3425 : /*
3426 : * If we get here, view_query_is_auto_updatable() has verified that the
3427 : * view contains a single base relation.
3428 : */
3429 : Assert(list_length(viewquery->jointree->fromlist) == 1);
3430 3098 : rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
3431 :
3432 3098 : base_rt_index = rtr->rtindex;
3433 3098 : base_rte = rt_fetch(base_rt_index, viewquery->rtable);
3434 : Assert(base_rte->rtekind == RTE_RELATION);
3435 3098 : base_perminfo = getRTEPermissionInfo(viewquery->rteperminfos, base_rte);
3436 :
3437 : /*
3438 : * Up to now, the base relation hasn't been touched at all in our query.
3439 : * We need to acquire lock on it before we try to do anything with it.
3440 : * (The subsequent recursive call of RewriteQuery will suppose that we
3441 : * already have the right lock!) Since it will become the query target
3442 : * relation, RowExclusiveLock is always the right thing.
3443 : */
3444 3098 : base_rel = table_open(base_rte->relid, RowExclusiveLock);
3445 :
3446 : /*
3447 : * While we have the relation open, update the RTE's relkind, just in case
3448 : * it changed since this view was made (cf. AcquireRewriteLocks).
3449 : */
3450 3098 : base_rte->relkind = base_rel->rd_rel->relkind;
3451 :
3452 : /*
3453 : * If the view query contains any sublink subqueries then we need to also
3454 : * acquire locks on any relations they refer to. We know that there won't
3455 : * be any subqueries in the range table or CTEs, so we can skip those, as
3456 : * in AcquireRewriteLocks.
3457 : */
3458 3098 : if (viewquery->hasSubLinks)
3459 : {
3460 : acquireLocksOnSubLinks_context context;
3461 :
3462 180 : context.for_execute = true;
3463 180 : query_tree_walker(viewquery, acquireLocksOnSubLinks, &context,
3464 : QTW_IGNORE_RC_SUBQUERIES);
3465 : }
3466 :
3467 : /*
3468 : * Create a new target RTE describing the base relation, and add it to the
3469 : * outer query's rangetable. (What's happening in the next few steps is
3470 : * very much like what the planner would do to "pull up" the view into the
3471 : * outer query. Perhaps someday we should refactor things enough so that
3472 : * we can share code with the planner.)
3473 : *
3474 : * Be sure to set rellockmode to the correct thing for the target table.
3475 : * Since we copied the whole viewquery above, we can just scribble on
3476 : * base_rte instead of copying it.
3477 : */
3478 3098 : new_rte = base_rte;
3479 3098 : new_rte->rellockmode = RowExclusiveLock;
3480 :
3481 3098 : parsetree->rtable = lappend(parsetree->rtable, new_rte);
3482 3098 : new_rt_index = list_length(parsetree->rtable);
3483 :
3484 : /*
3485 : * INSERTs never inherit. For UPDATE/DELETE/MERGE, we use the view
3486 : * query's inheritance flag for the base relation.
3487 : */
3488 3098 : if (parsetree->commandType == CMD_INSERT)
3489 1056 : new_rte->inh = false;
3490 :
3491 : /*
3492 : * Adjust the view's targetlist Vars to reference the new target RTE, ie
3493 : * make their varnos be new_rt_index instead of base_rt_index. There can
3494 : * be no Vars for other rels in the tlist, so this is sufficient to pull
3495 : * up the tlist expressions for use in the outer query. The tlist will
3496 : * provide the replacement expressions used by ReplaceVarsFromTargetList
3497 : * below.
3498 : */
3499 3098 : view_targetlist = viewquery->targetList;
3500 :
3501 3098 : ChangeVarNodes((Node *) view_targetlist,
3502 : base_rt_index,
3503 : new_rt_index,
3504 : 0);
3505 :
3506 : /*
3507 : * If the view has "security_invoker" set, mark the new target relation
3508 : * for the permissions checks that we want to enforce against the query
3509 : * caller. Otherwise we want to enforce them against the view owner.
3510 : *
3511 : * At the relation level, require the same INSERT/UPDATE/DELETE
3512 : * permissions that the query caller needs against the view. We drop the
3513 : * ACL_SELECT bit that is presumably in new_perminfo->requiredPerms
3514 : * initially.
3515 : *
3516 : * Note: the original view's RTEPermissionInfo remains in the query's
3517 : * rteperminfos so that the executor still performs appropriate
3518 : * permissions checks for the query caller's use of the view.
3519 : *
3520 : * Disregard the perminfo in viewquery->rteperminfos that the base_rte
3521 : * would currently be pointing at, because we'd like it to point now to a
3522 : * new one that will be filled below. Must set perminfoindex to 0 to not
3523 : * trip over the Assert in addRTEPermissionInfo().
3524 : */
3525 3098 : new_rte->perminfoindex = 0;
3526 3098 : new_perminfo = addRTEPermissionInfo(&parsetree->rteperminfos, new_rte);
3527 3098 : if (RelationHasSecurityInvoker(view))
3528 486 : new_perminfo->checkAsUser = InvalidOid;
3529 : else
3530 2612 : new_perminfo->checkAsUser = view->rd_rel->relowner;
3531 3098 : new_perminfo->requiredPerms = view_perminfo->requiredPerms;
3532 :
3533 : /*
3534 : * Now for the per-column permissions bits.
3535 : *
3536 : * Initially, new_perminfo (base_perminfo) contains selectedCols
3537 : * permission check bits for all base-rel columns referenced by the view,
3538 : * but since the view is a SELECT query its insertedCols/updatedCols is
3539 : * empty. We set insertedCols and updatedCols to include all the columns
3540 : * the outer query is trying to modify, adjusting the column numbers as
3541 : * needed. But we leave selectedCols as-is, so the view owner must have
3542 : * read permission for all columns used in the view definition, even if
3543 : * some of them are not read by the outer query. We could try to limit
3544 : * selectedCols to only columns used in the transformed query, but that
3545 : * does not correspond to what happens in ordinary SELECT usage of a view:
3546 : * all referenced columns must have read permission, even if optimization
3547 : * finds that some of them can be discarded during query transformation.
3548 : * The flattening we're doing here is an optional optimization, too. (If
3549 : * you are unpersuaded and want to change this, note that applying
3550 : * adjust_view_column_set to view_perminfo->selectedCols is clearly *not*
3551 : * the right answer, since that neglects base-rel columns used in the
3552 : * view's WHERE quals.)
3553 : *
3554 : * This step needs the modified view targetlist, so we have to do things
3555 : * in this order.
3556 : */
3557 : Assert(bms_is_empty(new_perminfo->insertedCols) &&
3558 : bms_is_empty(new_perminfo->updatedCols));
3559 :
3560 3098 : new_perminfo->selectedCols = base_perminfo->selectedCols;
3561 :
3562 3098 : new_perminfo->insertedCols =
3563 3098 : adjust_view_column_set(view_perminfo->insertedCols, view_targetlist);
3564 :
3565 3098 : new_perminfo->updatedCols =
3566 3098 : adjust_view_column_set(view_perminfo->updatedCols, view_targetlist);
3567 :
3568 : /*
3569 : * Move any security barrier quals from the view RTE onto the new target
3570 : * RTE. Any such quals should now apply to the new target RTE and will
3571 : * not reference the original view RTE in the rewritten query.
3572 : */
3573 3098 : new_rte->securityQuals = view_rte->securityQuals;
3574 3098 : view_rte->securityQuals = NIL;
3575 :
3576 : /*
3577 : * Now update all Vars in the outer query that reference the view to
3578 : * reference the appropriate column of the base relation instead.
3579 : */
3580 : parsetree = (Query *)
3581 3098 : ReplaceVarsFromTargetList((Node *) parsetree,
3582 : parsetree->resultRelation,
3583 : 0,
3584 : view_rte,
3585 : view_targetlist,
3586 : REPLACEVARS_REPORT_ERROR,
3587 : 0,
3588 : NULL);
3589 :
3590 : /*
3591 : * Update all other RTI references in the query that point to the view
3592 : * (for example, parsetree->resultRelation itself) to point to the new
3593 : * base relation instead. Vars will not be affected since none of them
3594 : * reference parsetree->resultRelation any longer.
3595 : */
3596 3098 : ChangeVarNodes((Node *) parsetree,
3597 : parsetree->resultRelation,
3598 : new_rt_index,
3599 : 0);
3600 : Assert(parsetree->resultRelation == new_rt_index);
3601 :
3602 : /*
3603 : * For INSERT/UPDATE we must also update resnos in the targetlist to refer
3604 : * to columns of the base relation, since those indicate the target
3605 : * columns to be affected. Similarly, for MERGE we must update the resnos
3606 : * in the merge action targetlists of any INSERT/UPDATE actions.
3607 : *
3608 : * Note that this destroys the resno ordering of the targetlists, but that
3609 : * will be fixed when we recurse through RewriteQuery, which will invoke
3610 : * rewriteTargetListIU again on the updated targetlists.
3611 : */
3612 3098 : if (parsetree->commandType != CMD_DELETE)
3613 : {
3614 5744 : foreach(lc, parsetree->targetList)
3615 : {
3616 2940 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3617 : TargetEntry *view_tle;
3618 :
3619 2940 : if (tle->resjunk)
3620 0 : continue;
3621 :
3622 2940 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3623 2940 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3624 2940 : tle->resno = ((Var *) view_tle->expr)->varattno;
3625 : else
3626 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3627 : tle->resno);
3628 : }
3629 :
3630 6598 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3631 : {
3632 990 : if (action->commandType == CMD_INSERT ||
3633 816 : action->commandType == CMD_UPDATE)
3634 : {
3635 2736 : foreach_node(TargetEntry, tle, action->targetList)
3636 : {
3637 : TargetEntry *view_tle;
3638 :
3639 1020 : if (tle->resjunk)
3640 0 : continue;
3641 :
3642 1020 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3643 1020 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3644 1020 : tle->resno = ((Var *) view_tle->expr)->varattno;
3645 : else
3646 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3647 : tle->resno);
3648 : }
3649 : }
3650 : }
3651 : }
3652 :
3653 : /*
3654 : * For INSERT .. ON CONFLICT .. DO UPDATE, we must also update assorted
3655 : * stuff in the onConflict data structure.
3656 : */
3657 3098 : if (parsetree->onConflict &&
3658 168 : parsetree->onConflict->action == ONCONFLICT_UPDATE)
3659 : {
3660 : Index old_exclRelIndex,
3661 : new_exclRelIndex;
3662 : ParseNamespaceItem *new_exclNSItem;
3663 : RangeTblEntry *new_exclRte;
3664 : List *tmp_tlist;
3665 :
3666 : /*
3667 : * Like the INSERT/UPDATE code above, update the resnos in the
3668 : * auxiliary UPDATE targetlist to refer to columns of the base
3669 : * relation.
3670 : */
3671 288 : foreach(lc, parsetree->onConflict->onConflictSet)
3672 : {
3673 144 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3674 : TargetEntry *view_tle;
3675 :
3676 144 : if (tle->resjunk)
3677 0 : continue;
3678 :
3679 144 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3680 144 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3681 144 : tle->resno = ((Var *) view_tle->expr)->varattno;
3682 : else
3683 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3684 : tle->resno);
3685 : }
3686 :
3687 : /*
3688 : * Also, create a new RTE for the EXCLUDED pseudo-relation, using the
3689 : * query's new base rel (which may well have a different column list
3690 : * from the view, hence we need a new column alias list). This should
3691 : * match transformOnConflictClause. In particular, note that the
3692 : * relkind is set to composite to signal that we're not dealing with
3693 : * an actual relation.
3694 : */
3695 144 : old_exclRelIndex = parsetree->onConflict->exclRelIndex;
3696 :
3697 144 : new_exclNSItem = addRangeTableEntryForRelation(make_parsestate(NULL),
3698 : base_rel,
3699 : RowExclusiveLock,
3700 : makeAlias("excluded", NIL),
3701 : false, false);
3702 144 : new_exclRte = new_exclNSItem->p_rte;
3703 144 : new_exclRte->relkind = RELKIND_COMPOSITE_TYPE;
3704 : /* Ignore the RTEPermissionInfo that would've been added. */
3705 144 : new_exclRte->perminfoindex = 0;
3706 :
3707 144 : parsetree->rtable = lappend(parsetree->rtable, new_exclRte);
3708 288 : new_exclRelIndex = parsetree->onConflict->exclRelIndex =
3709 144 : list_length(parsetree->rtable);
3710 :
3711 : /*
3712 : * Replace the targetlist for the EXCLUDED pseudo-relation with a new
3713 : * one, representing the columns from the new base relation.
3714 : */
3715 288 : parsetree->onConflict->exclRelTlist =
3716 144 : BuildOnConflictExcludedTargetlist(base_rel, new_exclRelIndex);
3717 :
3718 : /*
3719 : * Update all Vars in the ON CONFLICT clause that refer to the old
3720 : * EXCLUDED pseudo-relation. We want to use the column mappings
3721 : * defined in the view targetlist, but we need the outputs to refer to
3722 : * the new EXCLUDED pseudo-relation rather than the new target RTE.
3723 : * Also notice that "EXCLUDED.*" will be expanded using the view's
3724 : * rowtype, which seems correct.
3725 : */
3726 144 : tmp_tlist = copyObject(view_targetlist);
3727 :
3728 144 : ChangeVarNodes((Node *) tmp_tlist, new_rt_index,
3729 : new_exclRelIndex, 0);
3730 :
3731 144 : parsetree->onConflict = (OnConflictExpr *)
3732 144 : ReplaceVarsFromTargetList((Node *) parsetree->onConflict,
3733 : old_exclRelIndex,
3734 : 0,
3735 : view_rte,
3736 : tmp_tlist,
3737 : REPLACEVARS_REPORT_ERROR,
3738 : 0,
3739 : &parsetree->hasSubLinks);
3740 : }
3741 :
3742 : /*
3743 : * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view. We
3744 : * know that any Vars in the quals must reference the one base relation,
3745 : * so we need only adjust their varnos to reference the new target (just
3746 : * the same as we did with the view targetlist).
3747 : *
3748 : * If it's a security-barrier view, its WHERE quals must be applied before
3749 : * quals from the outer query, so we attach them to the RTE as security
3750 : * barrier quals rather than adding them to the main WHERE clause.
3751 : *
3752 : * For INSERT, the view's quals can be ignored in the main query.
3753 : */
3754 3098 : if (parsetree->commandType != CMD_INSERT &&
3755 2042 : viewquery->jointree->quals != NULL)
3756 : {
3757 698 : Node *viewqual = (Node *) viewquery->jointree->quals;
3758 :
3759 : /*
3760 : * Even though we copied viewquery already at the top of this
3761 : * function, we must duplicate the viewqual again here, because we may
3762 : * need to use the quals again below for a WithCheckOption clause.
3763 : */
3764 698 : viewqual = copyObject(viewqual);
3765 :
3766 698 : ChangeVarNodes(viewqual, base_rt_index, new_rt_index, 0);
3767 :
3768 698 : if (RelationIsSecurityView(view))
3769 : {
3770 : /*
3771 : * The view's quals go in front of existing barrier quals: those
3772 : * would have come from an outer level of security-barrier view,
3773 : * and so must get evaluated later.
3774 : *
3775 : * Note: the parsetree has been mutated, so the new_rte pointer is
3776 : * stale and needs to be re-computed.
3777 : */
3778 234 : new_rte = rt_fetch(new_rt_index, parsetree->rtable);
3779 234 : new_rte->securityQuals = lcons(viewqual, new_rte->securityQuals);
3780 :
3781 : /*
3782 : * Do not set parsetree->hasRowSecurity, because these aren't RLS
3783 : * conditions (they aren't affected by enabling/disabling RLS).
3784 : */
3785 :
3786 : /*
3787 : * Make sure that the query is marked correctly if the added qual
3788 : * has sublinks.
3789 : */
3790 234 : if (!parsetree->hasSubLinks)
3791 210 : parsetree->hasSubLinks = checkExprHasSubLink(viewqual);
3792 : }
3793 : else
3794 464 : AddQual(parsetree, (Node *) viewqual);
3795 : }
3796 :
3797 : /*
3798 : * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
3799 : * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
3800 : * OPTION, add the quals from the view to the query's withCheckOptions
3801 : * list.
3802 : */
3803 3098 : if (insert_or_update)
3804 : {
3805 2744 : bool has_wco = RelationHasCheckOption(view);
3806 2744 : bool cascaded = RelationHasCascadedCheckOption(view);
3807 :
3808 : /*
3809 : * If the parent view has a cascaded check option, treat this view as
3810 : * if it also had a cascaded check option.
3811 : *
3812 : * New WithCheckOptions are added to the start of the list, so if
3813 : * there is a cascaded check option, it will be the first item in the
3814 : * list.
3815 : */
3816 2744 : if (parsetree->withCheckOptions != NIL)
3817 : {
3818 114 : WithCheckOption *parent_wco =
3819 114 : (WithCheckOption *) linitial(parsetree->withCheckOptions);
3820 :
3821 114 : if (parent_wco->cascaded)
3822 : {
3823 90 : has_wco = true;
3824 90 : cascaded = true;
3825 : }
3826 : }
3827 :
3828 : /*
3829 : * Add the new WithCheckOption to the start of the list, so that
3830 : * checks on inner views are run before checks on outer views, as
3831 : * required by the SQL standard.
3832 : *
3833 : * If the new check is CASCADED, we need to add it even if this view
3834 : * has no quals, since there may be quals on child views. A LOCAL
3835 : * check can be omitted if this view has no quals.
3836 : */
3837 2744 : if (has_wco && (cascaded || viewquery->jointree->quals != NULL))
3838 : {
3839 : WithCheckOption *wco;
3840 :
3841 626 : wco = makeNode(WithCheckOption);
3842 626 : wco->kind = WCO_VIEW_CHECK;
3843 626 : wco->relname = pstrdup(RelationGetRelationName(view));
3844 626 : wco->polname = NULL;
3845 626 : wco->qual = NULL;
3846 626 : wco->cascaded = cascaded;
3847 :
3848 626 : parsetree->withCheckOptions = lcons(wco,
3849 : parsetree->withCheckOptions);
3850 :
3851 626 : if (viewquery->jointree->quals != NULL)
3852 : {
3853 566 : wco->qual = (Node *) viewquery->jointree->quals;
3854 566 : ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
3855 :
3856 : /*
3857 : * For INSERT, make sure that the query is marked correctly if
3858 : * the added qual has sublinks. This can be skipped for
3859 : * UPDATE/MERGE, since the same qual will have already been
3860 : * added above, and the check will already have been done.
3861 : */
3862 566 : if (!parsetree->hasSubLinks &&
3863 470 : parsetree->commandType == CMD_INSERT)
3864 312 : parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
3865 : }
3866 : }
3867 : }
3868 :
3869 3098 : table_close(base_rel, NoLock);
3870 :
3871 3098 : return parsetree;
3872 : }
3873 :
3874 :
3875 : /*
3876 : * RewriteQuery -
3877 : * rewrites the query and apply the rules again on the queries rewritten
3878 : *
3879 : * rewrite_events is a list of open query-rewrite actions, so we can detect
3880 : * infinite recursion.
3881 : *
3882 : * orig_rt_length is the length of the originating query's rtable, for product
3883 : * queries created by fireRules(), and 0 otherwise. This is used to skip any
3884 : * already-processed VALUES RTEs from the original query.
3885 : */
3886 : static List *
3887 447914 : RewriteQuery(Query *parsetree, List *rewrite_events, int orig_rt_length)
3888 : {
3889 447914 : CmdType event = parsetree->commandType;
3890 447914 : bool instead = false;
3891 447914 : bool returning = false;
3892 447914 : bool updatableview = false;
3893 447914 : Query *qual_product = NULL;
3894 447914 : List *rewritten = NIL;
3895 : ListCell *lc1;
3896 :
3897 : /*
3898 : * First, recursively process any insert/update/delete/merge statements in
3899 : * WITH clauses. (We have to do this first because the WITH clauses may
3900 : * get copied into rule actions below.)
3901 : */
3902 450938 : foreach(lc1, parsetree->cteList)
3903 : {
3904 3054 : CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc1);
3905 3054 : Query *ctequery = castNode(Query, cte->ctequery);
3906 : List *newstuff;
3907 :
3908 3054 : if (ctequery->commandType == CMD_SELECT)
3909 2736 : continue;
3910 :
3911 318 : newstuff = RewriteQuery(ctequery, rewrite_events, 0);
3912 :
3913 : /*
3914 : * Currently we can only handle unconditional, single-statement DO
3915 : * INSTEAD rules correctly; we have to get exactly one non-utility
3916 : * Query out of the rewrite operation to stuff back into the CTE node.
3917 : */
3918 318 : if (list_length(newstuff) == 1)
3919 : {
3920 : /* Must check it's not a utility command */
3921 294 : ctequery = linitial_node(Query, newstuff);
3922 294 : if (!(ctequery->commandType == CMD_SELECT ||
3923 294 : ctequery->commandType == CMD_UPDATE ||
3924 228 : ctequery->commandType == CMD_INSERT ||
3925 72 : ctequery->commandType == CMD_DELETE ||
3926 18 : ctequery->commandType == CMD_MERGE))
3927 : {
3928 : /*
3929 : * Currently it could only be NOTIFY; this error message will
3930 : * need work if we ever allow other utility commands in rules.
3931 : */
3932 6 : ereport(ERROR,
3933 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3934 : errmsg("DO INSTEAD NOTIFY rules are not supported for data-modifying statements in WITH")));
3935 : }
3936 : /* WITH queries should never be canSetTag */
3937 : Assert(!ctequery->canSetTag);
3938 : /* Push the single Query back into the CTE node */
3939 288 : cte->ctequery = (Node *) ctequery;
3940 : }
3941 24 : else if (newstuff == NIL)
3942 : {
3943 6 : ereport(ERROR,
3944 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3945 : errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
3946 : }
3947 : else
3948 : {
3949 : ListCell *lc2;
3950 :
3951 : /* examine queries to determine which error message to issue */
3952 42 : foreach(lc2, newstuff)
3953 : {
3954 36 : Query *q = (Query *) lfirst(lc2);
3955 :
3956 36 : if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
3957 6 : ereport(ERROR,
3958 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3959 : errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in WITH")));
3960 30 : if (q->querySource == QSRC_NON_INSTEAD_RULE)
3961 6 : ereport(ERROR,
3962 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3963 : errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
3964 : }
3965 :
3966 6 : ereport(ERROR,
3967 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3968 : errmsg("multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
3969 : }
3970 : }
3971 :
3972 : /*
3973 : * If the statement is an insert, update, delete, or merge, adjust its
3974 : * targetlist as needed, and then fire INSERT/UPDATE/DELETE rules on it.
3975 : *
3976 : * SELECT rules are handled later when we have all the queries that should
3977 : * get executed. Also, utilities aren't rewritten at all (do we still
3978 : * need that check?)
3979 : */
3980 447884 : if (event != CMD_SELECT && event != CMD_UTILITY)
3981 : {
3982 : int result_relation;
3983 : RangeTblEntry *rt_entry;
3984 : Relation rt_entry_relation;
3985 : List *locks;
3986 : int product_orig_rt_length;
3987 : List *product_queries;
3988 93812 : bool hasUpdate = false;
3989 93812 : int values_rte_index = 0;
3990 93812 : bool defaults_remaining = false;
3991 :
3992 93812 : result_relation = parsetree->resultRelation;
3993 : Assert(result_relation != 0);
3994 93812 : rt_entry = rt_fetch(result_relation, parsetree->rtable);
3995 : Assert(rt_entry->rtekind == RTE_RELATION);
3996 :
3997 : /*
3998 : * We can use NoLock here since either the parser or
3999 : * AcquireRewriteLocks should have locked the rel already.
4000 : */
4001 93812 : rt_entry_relation = table_open(rt_entry->relid, NoLock);
4002 :
4003 : /*
4004 : * Rewrite the targetlist as needed for the command type.
4005 : */
4006 93812 : if (event == CMD_INSERT)
4007 : {
4008 : ListCell *lc2;
4009 72628 : RangeTblEntry *values_rte = NULL;
4010 :
4011 : /*
4012 : * Test if it's a multi-row INSERT ... VALUES (...), (...), ... by
4013 : * looking for a VALUES RTE in the fromlist. For product queries,
4014 : * we must ignore any already-processed VALUES RTEs from the
4015 : * original query. These appear at the start of the rangetable.
4016 : */
4017 84298 : foreach(lc2, parsetree->jointree->fromlist)
4018 : {
4019 11670 : RangeTblRef *rtr = (RangeTblRef *) lfirst(lc2);
4020 :
4021 11670 : if (IsA(rtr, RangeTblRef) && rtr->rtindex > orig_rt_length)
4022 : {
4023 11346 : RangeTblEntry *rte = rt_fetch(rtr->rtindex,
4024 : parsetree->rtable);
4025 :
4026 11346 : if (rte->rtekind == RTE_VALUES)
4027 : {
4028 : /* should not find more than one VALUES RTE */
4029 4506 : if (values_rte != NULL)
4030 0 : elog(ERROR, "more than one VALUES RTE found");
4031 :
4032 4506 : values_rte = rte;
4033 4506 : values_rte_index = rtr->rtindex;
4034 : }
4035 : }
4036 : }
4037 :
4038 72628 : if (values_rte)
4039 : {
4040 4506 : Bitmapset *unused_values_attrnos = NULL;
4041 :
4042 : /* Process the main targetlist ... */
4043 4506 : parsetree->targetList = rewriteTargetListIU(parsetree->targetList,
4044 : parsetree->commandType,
4045 : parsetree->override,
4046 : rt_entry_relation,
4047 : values_rte,
4048 : values_rte_index,
4049 : &unused_values_attrnos);
4050 : /* ... and the VALUES expression lists */
4051 4446 : if (!rewriteValuesRTE(parsetree, values_rte, values_rte_index,
4052 : rt_entry_relation,
4053 : unused_values_attrnos))
4054 60 : defaults_remaining = true;
4055 : }
4056 : else
4057 : {
4058 : /* Process just the main targetlist */
4059 68068 : parsetree->targetList =
4060 68122 : rewriteTargetListIU(parsetree->targetList,
4061 : parsetree->commandType,
4062 : parsetree->override,
4063 : rt_entry_relation,
4064 : NULL, 0, NULL);
4065 : }
4066 :
4067 72514 : if (parsetree->onConflict &&
4068 1994 : parsetree->onConflict->action == ONCONFLICT_UPDATE)
4069 : {
4070 1420 : parsetree->onConflict->onConflictSet =
4071 1420 : rewriteTargetListIU(parsetree->onConflict->onConflictSet,
4072 : CMD_UPDATE,
4073 : parsetree->override,
4074 : rt_entry_relation,
4075 : NULL, 0, NULL);
4076 : }
4077 : }
4078 21184 : else if (event == CMD_UPDATE)
4079 : {
4080 : Assert(parsetree->override == OVERRIDING_NOT_SET);
4081 13816 : parsetree->targetList =
4082 13840 : rewriteTargetListIU(parsetree->targetList,
4083 : parsetree->commandType,
4084 : parsetree->override,
4085 : rt_entry_relation,
4086 : NULL, 0, NULL);
4087 : }
4088 7344 : else if (event == CMD_MERGE)
4089 : {
4090 : Assert(parsetree->override == OVERRIDING_NOT_SET);
4091 :
4092 : /*
4093 : * Rewrite each action targetlist separately
4094 : */
4095 6516 : foreach(lc1, parsetree->mergeActionList)
4096 : {
4097 3876 : MergeAction *action = (MergeAction *) lfirst(lc1);
4098 :
4099 3876 : switch (action->commandType)
4100 : {
4101 650 : case CMD_NOTHING:
4102 : case CMD_DELETE: /* Nothing to do here */
4103 650 : break;
4104 3226 : case CMD_UPDATE:
4105 : case CMD_INSERT:
4106 :
4107 : /*
4108 : * MERGE actions do not permit multi-row INSERTs, so
4109 : * there is no VALUES RTE to deal with here.
4110 : */
4111 3220 : action->targetList =
4112 3226 : rewriteTargetListIU(action->targetList,
4113 : action->commandType,
4114 : action->override,
4115 : rt_entry_relation,
4116 : NULL, 0, NULL);
4117 3220 : break;
4118 0 : default:
4119 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
4120 : break;
4121 : }
4122 : }
4123 : }
4124 4698 : else if (event == CMD_DELETE)
4125 : {
4126 : /* Nothing to do here */
4127 : }
4128 : else
4129 0 : elog(ERROR, "unrecognized commandType: %d", (int) event);
4130 :
4131 : /*
4132 : * Collect and apply the appropriate rules.
4133 : */
4134 93668 : locks = matchLocks(event, rt_entry_relation,
4135 : result_relation, parsetree, &hasUpdate);
4136 :
4137 93650 : product_orig_rt_length = list_length(parsetree->rtable);
4138 93650 : product_queries = fireRules(parsetree,
4139 : result_relation,
4140 : event,
4141 : locks,
4142 : &instead,
4143 : &returning,
4144 : &qual_product);
4145 :
4146 : /*
4147 : * If we have a VALUES RTE with any remaining untouched DEFAULT items,
4148 : * and we got any product queries, finalize the VALUES RTE for each
4149 : * product query (replacing the remaining DEFAULT items with NULLs).
4150 : * We don't do this for the original query, because we know that it
4151 : * must be an auto-insert on a view, and so should use the base
4152 : * relation's defaults for any remaining DEFAULT items.
4153 : */
4154 93644 : if (defaults_remaining && product_queries != NIL)
4155 : {
4156 : ListCell *n;
4157 :
4158 : /*
4159 : * Each product query has its own copy of the VALUES RTE at the
4160 : * same index in the rangetable, so we must finalize each one.
4161 : *
4162 : * Note that if the product query is an INSERT ... SELECT, then
4163 : * the VALUES RTE will be at the same index in the SELECT part of
4164 : * the product query rather than the top-level product query
4165 : * itself.
4166 : */
4167 48 : foreach(n, product_queries)
4168 : {
4169 24 : Query *pt = (Query *) lfirst(n);
4170 : RangeTblEntry *values_rte;
4171 :
4172 24 : if (pt->commandType == CMD_INSERT &&
4173 48 : pt->jointree && IsA(pt->jointree, FromExpr) &&
4174 24 : list_length(pt->jointree->fromlist) == 1)
4175 : {
4176 24 : Node *jtnode = (Node *) linitial(pt->jointree->fromlist);
4177 :
4178 24 : if (IsA(jtnode, RangeTblRef))
4179 : {
4180 24 : int rtindex = ((RangeTblRef *) jtnode)->rtindex;
4181 24 : RangeTblEntry *src_rte = rt_fetch(rtindex, pt->rtable);
4182 :
4183 24 : if (src_rte->rtekind == RTE_SUBQUERY &&
4184 6 : src_rte->subquery &&
4185 6 : IsA(src_rte->subquery, Query) &&
4186 6 : src_rte->subquery->commandType == CMD_SELECT)
4187 6 : pt = src_rte->subquery;
4188 : }
4189 : }
4190 :
4191 24 : values_rte = rt_fetch(values_rte_index, pt->rtable);
4192 24 : if (values_rte->rtekind != RTE_VALUES)
4193 0 : elog(ERROR, "failed to find VALUES RTE in product query");
4194 :
4195 24 : rewriteValuesRTEToNulls(pt, values_rte);
4196 : }
4197 : }
4198 :
4199 : /*
4200 : * If there was no unqualified INSTEAD rule, and the target relation
4201 : * is a view without any INSTEAD OF triggers, see if the view can be
4202 : * automatically updated. If so, we perform the necessary query
4203 : * transformation here and add the resulting query to the
4204 : * product_queries list, so that it gets recursively rewritten if
4205 : * necessary. For MERGE, the view must be automatically updatable if
4206 : * any of the merge actions lack a corresponding INSTEAD OF trigger.
4207 : *
4208 : * If the view cannot be automatically updated, we throw an error here
4209 : * which is OK since the query would fail at runtime anyway. Throwing
4210 : * the error here is preferable to the executor check since we have
4211 : * more detailed information available about why the view isn't
4212 : * updatable.
4213 : */
4214 93644 : if (!instead &&
4215 92990 : rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
4216 3776 : !view_has_instead_trigger(rt_entry_relation, event,
4217 : parsetree->mergeActionList))
4218 : {
4219 : /*
4220 : * If there were any qualified INSTEAD rules, don't allow the view
4221 : * to be automatically updated (an unqualified INSTEAD rule or
4222 : * INSTEAD OF trigger is required).
4223 : */
4224 3386 : if (qual_product != NULL)
4225 18 : error_view_not_updatable(rt_entry_relation,
4226 : parsetree->commandType,
4227 : parsetree->mergeActionList,
4228 : gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
4229 :
4230 : /*
4231 : * Attempt to rewrite the query to automatically update the view.
4232 : * This throws an error if the view can't be automatically
4233 : * updated.
4234 : */
4235 3368 : parsetree = rewriteTargetView(parsetree, rt_entry_relation);
4236 :
4237 : /*
4238 : * At this point product_queries contains any DO ALSO rule
4239 : * actions. Add the rewritten query before or after those. This
4240 : * must match the handling the original query would have gotten
4241 : * below, if we allowed it to be included again.
4242 : */
4243 3098 : if (parsetree->commandType == CMD_INSERT)
4244 1056 : product_queries = lcons(parsetree, product_queries);
4245 : else
4246 2042 : product_queries = lappend(product_queries, parsetree);
4247 :
4248 : /*
4249 : * Set the "instead" flag, as if there had been an unqualified
4250 : * INSTEAD, to prevent the original query from being included a
4251 : * second time below. The transformation will have rewritten any
4252 : * RETURNING list, so we can also set "returning" to forestall
4253 : * throwing an error below.
4254 : */
4255 3098 : instead = true;
4256 3098 : returning = true;
4257 3098 : updatableview = true;
4258 : }
4259 :
4260 : /*
4261 : * If we got any product queries, recursively rewrite them --- but
4262 : * first check for recursion!
4263 : */
4264 93356 : if (product_queries != NIL)
4265 : {
4266 : ListCell *n;
4267 : rewrite_event *rev;
4268 :
4269 5120 : foreach(n, rewrite_events)
4270 : {
4271 936 : rev = (rewrite_event *) lfirst(n);
4272 936 : if (rev->relation == RelationGetRelid(rt_entry_relation) &&
4273 0 : rev->event == event)
4274 0 : ereport(ERROR,
4275 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
4276 : errmsg("infinite recursion detected in rules for relation \"%s\"",
4277 : RelationGetRelationName(rt_entry_relation))));
4278 : }
4279 :
4280 4184 : rev = (rewrite_event *) palloc(sizeof(rewrite_event));
4281 4184 : rev->relation = RelationGetRelid(rt_entry_relation);
4282 4184 : rev->event = event;
4283 4184 : rewrite_events = lappend(rewrite_events, rev);
4284 :
4285 8494 : foreach(n, product_queries)
4286 : {
4287 4418 : Query *pt = (Query *) lfirst(n);
4288 : List *newstuff;
4289 :
4290 : /*
4291 : * For an updatable view, pt might be the rewritten version of
4292 : * the original query, in which case we pass on orig_rt_length
4293 : * to finish processing any VALUES RTE it contained.
4294 : *
4295 : * Otherwise, we have a product query created by fireRules().
4296 : * Any VALUES RTEs from the original query have been fully
4297 : * processed, and must be skipped when we recurse.
4298 : */
4299 4418 : newstuff = RewriteQuery(pt, rewrite_events,
4300 : pt == parsetree ?
4301 : orig_rt_length :
4302 : product_orig_rt_length);
4303 4310 : rewritten = list_concat(rewritten, newstuff);
4304 : }
4305 :
4306 4076 : rewrite_events = list_delete_last(rewrite_events);
4307 : }
4308 :
4309 : /*
4310 : * If there is an INSTEAD, and the original query has a RETURNING, we
4311 : * have to have found a RETURNING in the rule(s), else fail. (Because
4312 : * DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
4313 : * rules, there's no need to worry whether the substituted RETURNING
4314 : * will actually be executed --- it must be.)
4315 : */
4316 93248 : if ((instead || qual_product != NULL) &&
4317 3956 : parsetree->returningList &&
4318 270 : !returning)
4319 : {
4320 6 : switch (event)
4321 : {
4322 6 : case CMD_INSERT:
4323 6 : ereport(ERROR,
4324 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4325 : errmsg("cannot perform INSERT RETURNING on relation \"%s\"",
4326 : RelationGetRelationName(rt_entry_relation)),
4327 : errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.")));
4328 : break;
4329 0 : case CMD_UPDATE:
4330 0 : ereport(ERROR,
4331 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4332 : errmsg("cannot perform UPDATE RETURNING on relation \"%s\"",
4333 : RelationGetRelationName(rt_entry_relation)),
4334 : errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause.")));
4335 : break;
4336 0 : case CMD_DELETE:
4337 0 : ereport(ERROR,
4338 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4339 : errmsg("cannot perform DELETE RETURNING on relation \"%s\"",
4340 : RelationGetRelationName(rt_entry_relation)),
4341 : errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause.")));
4342 : break;
4343 0 : default:
4344 0 : elog(ERROR, "unrecognized commandType: %d",
4345 : (int) event);
4346 : break;
4347 : }
4348 93242 : }
4349 :
4350 : /*
4351 : * Updatable views are supported by ON CONFLICT, so don't prevent that
4352 : * case from proceeding
4353 : */
4354 93242 : if (parsetree->onConflict &&
4355 1802 : (product_queries != NIL || hasUpdate) &&
4356 180 : !updatableview)
4357 12 : ereport(ERROR,
4358 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4359 : errmsg("INSERT with ON CONFLICT clause cannot be used with table that has INSERT or UPDATE rules")));
4360 :
4361 93230 : table_close(rt_entry_relation, NoLock);
4362 : }
4363 :
4364 : /*
4365 : * For INSERTs, the original query is done first; for UPDATE/DELETE, it is
4366 : * done last. This is needed because update and delete rule actions might
4367 : * not do anything if they are invoked after the update or delete is
4368 : * performed. The command counter increment between the query executions
4369 : * makes the deleted (and maybe the updated) tuples disappear so the scans
4370 : * for them in the rule actions cannot find them.
4371 : *
4372 : * If we found any unqualified INSTEAD, the original query is not done at
4373 : * all, in any form. Otherwise, we add the modified form if qualified
4374 : * INSTEADs were found, else the unmodified form.
4375 : */
4376 447302 : if (!instead)
4377 : {
4378 443676 : if (parsetree->commandType == CMD_INSERT)
4379 : {
4380 70972 : if (qual_product != NULL)
4381 294 : rewritten = lcons(qual_product, rewritten);
4382 : else
4383 70678 : rewritten = lcons(parsetree, rewritten);
4384 : }
4385 : else
4386 : {
4387 372704 : if (qual_product != NULL)
4388 18 : rewritten = lappend(rewritten, qual_product);
4389 : else
4390 372686 : rewritten = lappend(rewritten, parsetree);
4391 : }
4392 : }
4393 :
4394 : /*
4395 : * If the original query has a CTE list, and we generated more than one
4396 : * non-utility result query, we have to fail because we'll have copied the
4397 : * CTE list into each result query. That would break the expectation of
4398 : * single evaluation of CTEs. This could possibly be fixed by
4399 : * restructuring so that a CTE list can be shared across multiple Query
4400 : * and PlannableStatement nodes.
4401 : */
4402 447302 : if (parsetree->cteList != NIL)
4403 : {
4404 2100 : int qcount = 0;
4405 :
4406 4200 : foreach(lc1, rewritten)
4407 : {
4408 2100 : Query *q = (Query *) lfirst(lc1);
4409 :
4410 2100 : if (q->commandType != CMD_UTILITY)
4411 2100 : qcount++;
4412 : }
4413 2100 : if (qcount > 1)
4414 0 : ereport(ERROR,
4415 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4416 : errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries")));
4417 : }
4418 :
4419 447302 : return rewritten;
4420 : }
4421 :
4422 :
4423 : /*
4424 : * QueryRewrite -
4425 : * Primary entry point to the query rewriter.
4426 : * Rewrite one query via query rewrite system, possibly returning 0
4427 : * or many queries.
4428 : *
4429 : * NOTE: the parsetree must either have come straight from the parser,
4430 : * or have been scanned by AcquireRewriteLocks to acquire suitable locks.
4431 : */
4432 : List *
4433 443178 : QueryRewrite(Query *parsetree)
4434 : {
4435 443178 : uint64 input_query_id = parsetree->queryId;
4436 : List *querylist;
4437 : List *results;
4438 : ListCell *l;
4439 : CmdType origCmdType;
4440 : bool foundOriginalQuery;
4441 : Query *lastInstead;
4442 :
4443 : /*
4444 : * This function is only applied to top-level original queries
4445 : */
4446 : Assert(parsetree->querySource == QSRC_ORIGINAL);
4447 : Assert(parsetree->canSetTag);
4448 :
4449 : /*
4450 : * Step 1
4451 : *
4452 : * Apply all non-SELECT rules possibly getting 0 or many queries
4453 : */
4454 443178 : querylist = RewriteQuery(parsetree, NIL, 0);
4455 :
4456 : /*
4457 : * Step 2
4458 : *
4459 : * Apply all the RIR rules on each query
4460 : *
4461 : * This is also a handy place to mark each query with the original queryId
4462 : */
4463 442674 : results = NIL;
4464 885900 : foreach(l, querylist)
4465 : {
4466 443328 : Query *query = (Query *) lfirst(l);
4467 :
4468 443328 : query = fireRIRrules(query, NIL);
4469 :
4470 443226 : query->queryId = input_query_id;
4471 :
4472 443226 : results = lappend(results, query);
4473 : }
4474 :
4475 : /*
4476 : * Step 3
4477 : *
4478 : * Determine which, if any, of the resulting queries is supposed to set
4479 : * the command-result tag; and update the canSetTag fields accordingly.
4480 : *
4481 : * If the original query is still in the list, it sets the command tag.
4482 : * Otherwise, the last INSTEAD query of the same kind as the original is
4483 : * allowed to set the tag. (Note these rules can leave us with no query
4484 : * setting the tag. The tcop code has to cope with this by setting up a
4485 : * default tag based on the original un-rewritten query.)
4486 : *
4487 : * The Asserts verify that at most one query in the result list is marked
4488 : * canSetTag. If we aren't checking asserts, we can fall out of the loop
4489 : * as soon as we find the original query.
4490 : */
4491 442572 : origCmdType = parsetree->commandType;
4492 442572 : foundOriginalQuery = false;
4493 442572 : lastInstead = NULL;
4494 :
4495 443376 : foreach(l, results)
4496 : {
4497 442770 : Query *query = (Query *) lfirst(l);
4498 :
4499 442770 : if (query->querySource == QSRC_ORIGINAL)
4500 : {
4501 : Assert(query->canSetTag);
4502 : Assert(!foundOriginalQuery);
4503 441966 : foundOriginalQuery = true;
4504 : #ifndef USE_ASSERT_CHECKING
4505 441966 : break;
4506 : #endif
4507 : }
4508 : else
4509 : {
4510 : Assert(!query->canSetTag);
4511 804 : if (query->commandType == origCmdType &&
4512 606 : (query->querySource == QSRC_INSTEAD_RULE ||
4513 108 : query->querySource == QSRC_QUAL_INSTEAD_RULE))
4514 546 : lastInstead = query;
4515 : }
4516 : }
4517 :
4518 442572 : if (!foundOriginalQuery && lastInstead != NULL)
4519 522 : lastInstead->canSetTag = true;
4520 :
4521 442572 : return results;
4522 : }
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