Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * rewriteHandler.c
4 : * Primary module of query rewriter.
5 : *
6 : * Portions Copyright (c) 1996-2025, 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 : static Node *expand_generated_columns_internal(Node *node, Relation rel, int rt_index,
100 : RangeTblEntry *rte, int result_relation);
101 :
102 :
103 : /*
104 : * AcquireRewriteLocks -
105 : * Acquire suitable locks on all the relations mentioned in the Query.
106 : * These locks will ensure that the relation schemas don't change under us
107 : * while we are rewriting, planning, and executing the query.
108 : *
109 : * Caution: this may modify the querytree, therefore caller should usually
110 : * have done a copyObject() to make a writable copy of the querytree in the
111 : * current memory context.
112 : *
113 : * forExecute indicates that the query is about to be executed. If so,
114 : * we'll acquire the lock modes specified in the RTE rellockmode fields.
115 : * If forExecute is false, AccessShareLock is acquired on all relations.
116 : * This case is suitable for ruleutils.c, for example, where we only need
117 : * schema stability and we don't intend to actually modify any relations.
118 : *
119 : * forUpdatePushedDown indicates that a pushed-down FOR [KEY] UPDATE/SHARE
120 : * applies to the current subquery, requiring all rels to be opened with at
121 : * least RowShareLock. This should always be false at the top of the
122 : * recursion. When it is true, we adjust RTE rellockmode fields to reflect
123 : * the higher lock level. This flag is ignored if forExecute is false.
124 : *
125 : * A secondary purpose of this routine is to fix up JOIN RTE references to
126 : * dropped columns (see details below). Such RTEs are modified in-place.
127 : *
128 : * This processing can, and for efficiency's sake should, be skipped when the
129 : * querytree has just been built by the parser: parse analysis already got
130 : * all the same locks we'd get here, and the parser will have omitted dropped
131 : * columns from JOINs to begin with. But we must do this whenever we are
132 : * dealing with a querytree produced earlier than the current command.
133 : *
134 : * About JOINs and dropped columns: although the parser never includes an
135 : * already-dropped column in a JOIN RTE's alias var list, it is possible for
136 : * such a list in a stored rule to include references to dropped columns.
137 : * (If the column is not explicitly referenced anywhere else in the query,
138 : * the dependency mechanism won't consider it used by the rule and so won't
139 : * prevent the column drop.) To support get_rte_attribute_is_dropped(), we
140 : * replace join alias vars that reference dropped columns with null pointers.
141 : *
142 : * (In PostgreSQL 8.0, we did not do this processing but instead had
143 : * get_rte_attribute_is_dropped() recurse to detect dropped columns in joins.
144 : * That approach had horrible performance unfortunately; in particular
145 : * construction of a nested join was O(N^2) in the nesting depth.)
146 : */
147 : void
148 42670 : AcquireRewriteLocks(Query *parsetree,
149 : bool forExecute,
150 : bool forUpdatePushedDown)
151 : {
152 : ListCell *l;
153 : int rt_index;
154 : acquireLocksOnSubLinks_context context;
155 :
156 42670 : context.for_execute = forExecute;
157 :
158 : /*
159 : * First, process RTEs of the current query level.
160 : */
161 42670 : rt_index = 0;
162 140002 : foreach(l, parsetree->rtable)
163 : {
164 97332 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
165 : Relation rel;
166 : LOCKMODE lockmode;
167 : List *newaliasvars;
168 : Index curinputvarno;
169 : RangeTblEntry *curinputrte;
170 : ListCell *ll;
171 :
172 97332 : ++rt_index;
173 97332 : switch (rte->rtekind)
174 : {
175 54384 : case RTE_RELATION:
176 :
177 : /*
178 : * Grab the appropriate lock type for the relation, and do not
179 : * release it until end of transaction. This protects the
180 : * rewriter, planner, and executor against schema changes
181 : * mid-query.
182 : *
183 : * If forExecute is false, ignore rellockmode and just use
184 : * AccessShareLock.
185 : */
186 54384 : if (!forExecute)
187 7982 : lockmode = AccessShareLock;
188 46402 : else if (forUpdatePushedDown)
189 : {
190 : /* Upgrade RTE's lock mode to reflect pushed-down lock */
191 96 : if (rte->rellockmode == AccessShareLock)
192 96 : rte->rellockmode = RowShareLock;
193 96 : lockmode = rte->rellockmode;
194 : }
195 : else
196 46306 : lockmode = rte->rellockmode;
197 :
198 54384 : rel = table_open(rte->relid, lockmode);
199 :
200 : /*
201 : * While we have the relation open, update the RTE's relkind,
202 : * just in case it changed since this rule was made.
203 : */
204 54384 : rte->relkind = rel->rd_rel->relkind;
205 :
206 54384 : table_close(rel, NoLock);
207 54384 : break;
208 :
209 24130 : case RTE_JOIN:
210 :
211 : /*
212 : * Scan the join's alias var list to see if any columns have
213 : * been dropped, and if so replace those Vars with null
214 : * pointers.
215 : *
216 : * Since a join has only two inputs, we can expect to see
217 : * multiple references to the same input RTE; optimize away
218 : * multiple fetches.
219 : */
220 24130 : newaliasvars = NIL;
221 24130 : curinputvarno = 0;
222 24130 : curinputrte = NULL;
223 940440 : foreach(ll, rte->joinaliasvars)
224 : {
225 916310 : Var *aliasitem = (Var *) lfirst(ll);
226 916310 : Var *aliasvar = aliasitem;
227 :
228 : /* Look through any implicit coercion */
229 916310 : aliasvar = (Var *) strip_implicit_coercions((Node *) aliasvar);
230 :
231 : /*
232 : * If the list item isn't a simple Var, then it must
233 : * represent a merged column, ie a USING column, and so it
234 : * couldn't possibly be dropped, since it's referenced in
235 : * the join clause. (Conceivably it could also be a null
236 : * pointer already? But that's OK too.)
237 : */
238 916310 : if (aliasvar && IsA(aliasvar, Var))
239 : {
240 : /*
241 : * The elements of an alias list have to refer to
242 : * earlier RTEs of the same rtable, because that's the
243 : * order the planner builds things in. So we already
244 : * processed the referenced RTE, and so it's safe to
245 : * use get_rte_attribute_is_dropped on it. (This might
246 : * not hold after rewriting or planning, but it's OK
247 : * to assume here.)
248 : */
249 : Assert(aliasvar->varlevelsup == 0);
250 916136 : if (aliasvar->varno != curinputvarno)
251 : {
252 61350 : curinputvarno = aliasvar->varno;
253 61350 : if (curinputvarno >= rt_index)
254 0 : elog(ERROR, "unexpected varno %d in JOIN RTE %d",
255 : curinputvarno, rt_index);
256 61350 : curinputrte = rt_fetch(curinputvarno,
257 : parsetree->rtable);
258 : }
259 916136 : if (get_rte_attribute_is_dropped(curinputrte,
260 916136 : aliasvar->varattno))
261 : {
262 : /* Replace the join alias item with a NULL */
263 6 : aliasitem = NULL;
264 : }
265 : }
266 916310 : newaliasvars = lappend(newaliasvars, aliasitem);
267 : }
268 24130 : rte->joinaliasvars = newaliasvars;
269 24130 : break;
270 :
271 7512 : case RTE_SUBQUERY:
272 :
273 : /*
274 : * The subquery RTE itself is all right, but we have to
275 : * recurse to process the represented subquery.
276 : */
277 7512 : AcquireRewriteLocks(rte->subquery,
278 : forExecute,
279 15024 : (forUpdatePushedDown ||
280 7512 : get_parse_rowmark(parsetree, rt_index) != NULL));
281 7512 : break;
282 :
283 11306 : default:
284 : /* ignore other types of RTEs */
285 11306 : break;
286 : }
287 : }
288 :
289 : /* Recurse into subqueries in WITH */
290 42900 : foreach(l, parsetree->cteList)
291 : {
292 230 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(l);
293 :
294 230 : AcquireRewriteLocks((Query *) cte->ctequery, forExecute, false);
295 : }
296 :
297 : /*
298 : * Recurse into sublink subqueries, too. But we already did the ones in
299 : * the rtable and cteList.
300 : */
301 42670 : if (parsetree->hasSubLinks)
302 1776 : query_tree_walker(parsetree, acquireLocksOnSubLinks, &context,
303 : QTW_IGNORE_RC_SUBQUERIES);
304 42670 : }
305 :
306 : /*
307 : * Walker to find sublink subqueries for AcquireRewriteLocks
308 : */
309 : static bool
310 136384 : acquireLocksOnSubLinks(Node *node, acquireLocksOnSubLinks_context *context)
311 : {
312 136384 : if (node == NULL)
313 32362 : return false;
314 104022 : if (IsA(node, SubLink))
315 : {
316 4032 : SubLink *sub = (SubLink *) node;
317 :
318 : /* Do what we came for */
319 4032 : AcquireRewriteLocks((Query *) sub->subselect,
320 4032 : context->for_execute,
321 : false);
322 : /* Fall through to process lefthand args of SubLink */
323 : }
324 :
325 : /*
326 : * Do NOT recurse into Query nodes, because AcquireRewriteLocks already
327 : * processed subselects of subselects for us.
328 : */
329 104022 : return expression_tree_walker(node, acquireLocksOnSubLinks, context);
330 : }
331 :
332 :
333 : /*
334 : * rewriteRuleAction -
335 : * Rewrite the rule action with appropriate qualifiers (taken from
336 : * the triggering query).
337 : *
338 : * Input arguments:
339 : * parsetree - original query
340 : * rule_action - one action (query) of a rule
341 : * rule_qual - WHERE condition of rule, or NULL if unconditional
342 : * rt_index - RT index of result relation in original query
343 : * event - type of rule event
344 : * Output arguments:
345 : * *returning_flag - set true if we rewrite RETURNING clause in rule_action
346 : * (must be initialized to false)
347 : * Return value:
348 : * rewritten form of rule_action
349 : */
350 : static Query *
351 1386 : rewriteRuleAction(Query *parsetree,
352 : Query *rule_action,
353 : Node *rule_qual,
354 : int rt_index,
355 : CmdType event,
356 : bool *returning_flag)
357 : {
358 : int current_varno,
359 : new_varno;
360 : int rt_length;
361 : Query *sub_action;
362 : Query **sub_action_ptr;
363 : acquireLocksOnSubLinks_context context;
364 : ListCell *lc;
365 :
366 1386 : context.for_execute = true;
367 :
368 : /*
369 : * Make modifiable copies of rule action and qual (what we're passed are
370 : * the stored versions in the relcache; don't touch 'em!).
371 : */
372 1386 : rule_action = copyObject(rule_action);
373 1386 : rule_qual = copyObject(rule_qual);
374 :
375 : /*
376 : * Acquire necessary locks and fix any deleted JOIN RTE entries.
377 : */
378 1386 : AcquireRewriteLocks(rule_action, true, false);
379 1386 : (void) acquireLocksOnSubLinks(rule_qual, &context);
380 :
381 1386 : current_varno = rt_index;
382 1386 : rt_length = list_length(parsetree->rtable);
383 1386 : new_varno = PRS2_NEW_VARNO + rt_length;
384 :
385 : /*
386 : * Adjust rule action and qual to offset its varnos, so that we can merge
387 : * its rtable with the main parsetree's rtable.
388 : *
389 : * If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries
390 : * will be in the SELECT part, and we have to modify that rather than the
391 : * top-level INSERT (kluge!).
392 : */
393 1386 : sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr);
394 :
395 1386 : OffsetVarNodes((Node *) sub_action, rt_length, 0);
396 1386 : OffsetVarNodes(rule_qual, rt_length, 0);
397 : /* but references to OLD should point at original rt_index */
398 1386 : ChangeVarNodes((Node *) sub_action,
399 : PRS2_OLD_VARNO + rt_length, rt_index, 0);
400 1386 : ChangeVarNodes(rule_qual,
401 : PRS2_OLD_VARNO + rt_length, rt_index, 0);
402 :
403 : /*
404 : * Mark any subquery RTEs in the rule action as LATERAL if they contain
405 : * Vars referring to the current query level (references to NEW/OLD).
406 : * Those really are lateral references, but we've historically not
407 : * required users to mark such subqueries with LATERAL explicitly. But
408 : * the planner will complain if such Vars exist in a non-LATERAL subquery,
409 : * so we have to fix things up here.
410 : */
411 5484 : foreach(lc, sub_action->rtable)
412 : {
413 4098 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
414 :
415 4110 : if (rte->rtekind == RTE_SUBQUERY && !rte->lateral &&
416 12 : contain_vars_of_level((Node *) rte->subquery, 1))
417 12 : rte->lateral = true;
418 : }
419 :
420 : /*
421 : * Generate expanded rtable consisting of main parsetree's rtable plus
422 : * rule action's rtable; this becomes the complete rtable for the rule
423 : * action. Some of the entries may be unused after we finish rewriting,
424 : * but we leave them all in place to avoid having to adjust the query's
425 : * varnos. RT entries that are not referenced in the completed jointree
426 : * will be ignored by the planner, so they do not affect query semantics.
427 : *
428 : * Also merge RTEPermissionInfo lists to ensure that all permissions are
429 : * checked correctly.
430 : *
431 : * If the rule is INSTEAD, then the original query won't be executed at
432 : * all, and so its rteperminfos must be preserved so that the executor
433 : * will do the correct permissions checks on the relations referenced in
434 : * it. This allows us to check that the caller has, say, insert-permission
435 : * on a view, when the view is not semantically referenced at all in the
436 : * resulting query.
437 : *
438 : * When a rule is not INSTEAD, the permissions checks done using the
439 : * copied entries will be redundant with those done during execution of
440 : * the original query, but we don't bother to treat that case differently.
441 : *
442 : * NOTE: because planner will destructively alter rtable and rteperminfos,
443 : * we must ensure that rule action's lists are separate and shares no
444 : * substructure with the main query's lists. Hence do a deep copy here
445 : * for both.
446 : */
447 : {
448 1386 : List *rtable_tail = sub_action->rtable;
449 1386 : List *perminfos_tail = sub_action->rteperminfos;
450 :
451 : /*
452 : * RewriteQuery relies on the fact that RT entries from the original
453 : * query appear at the start of the expanded rtable, so we put the
454 : * action's original table at the end of the list.
455 : */
456 1386 : sub_action->rtable = copyObject(parsetree->rtable);
457 1386 : sub_action->rteperminfos = copyObject(parsetree->rteperminfos);
458 1386 : CombineRangeTables(&sub_action->rtable, &sub_action->rteperminfos,
459 : rtable_tail, perminfos_tail);
460 : }
461 :
462 : /*
463 : * There could have been some SubLinks in parsetree's rtable, in which
464 : * case we'd better mark the sub_action correctly.
465 : */
466 1386 : if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
467 : {
468 66 : foreach(lc, parsetree->rtable)
469 : {
470 48 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
471 :
472 48 : switch (rte->rtekind)
473 : {
474 42 : case RTE_RELATION:
475 42 : sub_action->hasSubLinks =
476 42 : checkExprHasSubLink((Node *) rte->tablesample);
477 42 : break;
478 0 : case RTE_FUNCTION:
479 0 : sub_action->hasSubLinks =
480 0 : checkExprHasSubLink((Node *) rte->functions);
481 0 : break;
482 0 : case RTE_TABLEFUNC:
483 0 : sub_action->hasSubLinks =
484 0 : checkExprHasSubLink((Node *) rte->tablefunc);
485 0 : break;
486 0 : case RTE_VALUES:
487 0 : sub_action->hasSubLinks =
488 0 : checkExprHasSubLink((Node *) rte->values_lists);
489 0 : break;
490 6 : default:
491 : /* other RTE types don't contain bare expressions */
492 6 : break;
493 : }
494 48 : sub_action->hasSubLinks |=
495 48 : checkExprHasSubLink((Node *) rte->securityQuals);
496 48 : if (sub_action->hasSubLinks)
497 6 : break; /* no need to keep scanning rtable */
498 : }
499 : }
500 :
501 : /*
502 : * Also, we might have absorbed some RTEs with RLS conditions into the
503 : * sub_action. If so, mark it as hasRowSecurity, whether or not those
504 : * RTEs will be referenced after we finish rewriting. (Note: currently
505 : * this is a no-op because RLS conditions aren't added till later, but it
506 : * seems like good future-proofing to do this anyway.)
507 : */
508 1386 : sub_action->hasRowSecurity |= parsetree->hasRowSecurity;
509 :
510 : /*
511 : * Each rule action's jointree should be the main parsetree's jointree
512 : * plus that rule's jointree, but usually *without* the original rtindex
513 : * that we're replacing (if present, which it won't be for INSERT). Note
514 : * that if the rule action refers to OLD, its jointree will add a
515 : * reference to rt_index. If the rule action doesn't refer to OLD, but
516 : * either the rule_qual or the user query quals do, then we need to keep
517 : * the original rtindex in the jointree to provide data for the quals. We
518 : * don't want the original rtindex to be joined twice, however, so avoid
519 : * keeping it if the rule action mentions it.
520 : *
521 : * As above, the action's jointree must not share substructure with the
522 : * main parsetree's.
523 : */
524 1386 : if (sub_action->commandType != CMD_UTILITY)
525 : {
526 : bool keeporig;
527 : List *newjointree;
528 :
529 : Assert(sub_action->jointree != NULL);
530 1356 : keeporig = (!rangeTableEntry_used((Node *) sub_action->jointree,
531 3168 : rt_index, 0)) &&
532 1812 : (rangeTableEntry_used(rule_qual, rt_index, 0) ||
533 906 : rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0));
534 1356 : newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index);
535 1356 : if (newjointree != NIL)
536 : {
537 : /*
538 : * If sub_action is a setop, manipulating its jointree will do no
539 : * good at all, because the jointree is dummy. (Perhaps someday
540 : * we could push the joining and quals down to the member
541 : * statements of the setop?)
542 : */
543 276 : if (sub_action->setOperations != NULL)
544 0 : ereport(ERROR,
545 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
546 : errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
547 :
548 552 : sub_action->jointree->fromlist =
549 276 : list_concat(newjointree, sub_action->jointree->fromlist);
550 :
551 : /*
552 : * There could have been some SubLinks in newjointree, in which
553 : * case we'd better mark the sub_action correctly.
554 : */
555 276 : if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
556 6 : sub_action->hasSubLinks =
557 6 : checkExprHasSubLink((Node *) newjointree);
558 : }
559 : }
560 :
561 : /*
562 : * If the original query has any CTEs, copy them into the rule action. But
563 : * we don't need them for a utility action.
564 : */
565 1386 : if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY)
566 : {
567 : /*
568 : * Annoying implementation restriction: because CTEs are identified by
569 : * name within a cteList, we can't merge a CTE from the original query
570 : * if it has the same name as any CTE in the rule action.
571 : *
572 : * This could possibly be fixed by using some sort of internally
573 : * generated ID, instead of names, to link CTE RTEs to their CTEs.
574 : * However, decompiling the results would be quite confusing; note the
575 : * merge of hasRecursive flags below, which could change the apparent
576 : * semantics of such redundantly-named CTEs.
577 : */
578 72 : foreach(lc, parsetree->cteList)
579 : {
580 36 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
581 : ListCell *lc2;
582 :
583 42 : foreach(lc2, sub_action->cteList)
584 : {
585 6 : CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(lc2);
586 :
587 6 : if (strcmp(cte->ctename, cte2->ctename) == 0)
588 0 : ereport(ERROR,
589 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
590 : errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten",
591 : cte->ctename)));
592 : }
593 : }
594 :
595 : /*
596 : * OK, it's safe to combine the CTE lists. Beware that RewriteQuery
597 : * knows we concatenate the lists in this order.
598 : */
599 36 : sub_action->cteList = list_concat(sub_action->cteList,
600 36 : copyObject(parsetree->cteList));
601 : /* ... and don't forget about the associated flags */
602 36 : sub_action->hasRecursive |= parsetree->hasRecursive;
603 36 : sub_action->hasModifyingCTE |= parsetree->hasModifyingCTE;
604 :
605 : /*
606 : * If rule_action is different from sub_action (i.e., the rule action
607 : * is an INSERT...SELECT), then we might have just added some
608 : * data-modifying CTEs that are not at the top query level. This is
609 : * disallowed by the parser and we mustn't generate such trees here
610 : * either, so throw an error.
611 : *
612 : * Conceivably such cases could be supported by attaching the original
613 : * query's CTEs to rule_action not sub_action. But to do that, we'd
614 : * have to increment ctelevelsup in RTEs and SubLinks copied from the
615 : * original query. For now, it doesn't seem worth the trouble.
616 : */
617 36 : if (sub_action->hasModifyingCTE && rule_action != sub_action)
618 6 : ereport(ERROR,
619 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
620 : errmsg("INSERT ... SELECT rule actions are not supported for queries having data-modifying statements in WITH")));
621 : }
622 :
623 : /*
624 : * Event Qualification forces copying of parsetree and splitting into two
625 : * queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual
626 : * onto rule action
627 : */
628 1380 : AddQual(sub_action, rule_qual);
629 :
630 1380 : AddQual(sub_action, parsetree->jointree->quals);
631 :
632 : /*
633 : * Rewrite new.attribute with right hand side of target-list entry for
634 : * appropriate field name in insert/update.
635 : *
636 : * KLUGE ALERT: since ReplaceVarsFromTargetList returns a mutated copy, we
637 : * can't just apply it to sub_action; we have to remember to update the
638 : * sublink inside rule_action, too.
639 : */
640 1380 : if ((event == CMD_INSERT || event == CMD_UPDATE) &&
641 1200 : sub_action->commandType != CMD_UTILITY)
642 : {
643 : sub_action = (Query *)
644 2340 : ReplaceVarsFromTargetList((Node *) sub_action,
645 : new_varno,
646 : 0,
647 1170 : rt_fetch(new_varno, sub_action->rtable),
648 : parsetree->targetList,
649 : sub_action->resultRelation,
650 : (event == CMD_UPDATE) ?
651 : REPLACEVARS_CHANGE_VARNO :
652 : REPLACEVARS_SUBSTITUTE_NULL,
653 : current_varno,
654 : NULL);
655 1170 : if (sub_action_ptr)
656 54 : *sub_action_ptr = sub_action;
657 : else
658 1116 : rule_action = sub_action;
659 : }
660 :
661 : /*
662 : * If rule_action has a RETURNING clause, then either throw it away if the
663 : * triggering query has no RETURNING clause, or rewrite it to emit what
664 : * the triggering query's RETURNING clause asks for. Throw an error if
665 : * more than one rule has a RETURNING clause.
666 : */
667 1380 : if (!parsetree->returningList)
668 1224 : rule_action->returningList = NIL;
669 156 : else if (rule_action->returningList)
670 : {
671 144 : if (*returning_flag)
672 0 : ereport(ERROR,
673 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
674 : errmsg("cannot have RETURNING lists in multiple rules")));
675 144 : *returning_flag = true;
676 144 : rule_action->returningList = (List *)
677 144 : ReplaceVarsFromTargetList((Node *) parsetree->returningList,
678 : parsetree->resultRelation,
679 : 0,
680 144 : rt_fetch(parsetree->resultRelation,
681 : parsetree->rtable),
682 : rule_action->returningList,
683 : rule_action->resultRelation,
684 : REPLACEVARS_REPORT_ERROR,
685 : 0,
686 : &rule_action->hasSubLinks);
687 :
688 : /* use triggering query's aliases for OLD and NEW in RETURNING list */
689 144 : rule_action->returningOldAlias = parsetree->returningOldAlias;
690 144 : rule_action->returningNewAlias = parsetree->returningNewAlias;
691 :
692 : /*
693 : * There could have been some SubLinks in parsetree's returningList,
694 : * in which case we'd better mark the rule_action correctly.
695 : */
696 144 : if (parsetree->hasSubLinks && !rule_action->hasSubLinks)
697 0 : rule_action->hasSubLinks =
698 0 : checkExprHasSubLink((Node *) rule_action->returningList);
699 : }
700 :
701 1380 : return rule_action;
702 : }
703 :
704 : /*
705 : * Copy the query's jointree list, and optionally attempt to remove any
706 : * occurrence of the given rt_index as a top-level join item (we do not look
707 : * for it within join items; this is OK because we are only expecting to find
708 : * it as an UPDATE or DELETE target relation, which will be at the top level
709 : * of the join). Returns modified jointree list --- this is a separate copy
710 : * sharing no nodes with the original.
711 : */
712 : static List *
713 1356 : adjustJoinTreeList(Query *parsetree, bool removert, int rt_index)
714 : {
715 1356 : List *newjointree = copyObject(parsetree->jointree->fromlist);
716 : ListCell *l;
717 :
718 1356 : if (removert)
719 : {
720 1596 : foreach(l, newjointree)
721 : {
722 744 : RangeTblRef *rtr = lfirst(l);
723 :
724 744 : if (IsA(rtr, RangeTblRef) &&
725 744 : rtr->rtindex == rt_index)
726 : {
727 504 : newjointree = foreach_delete_current(newjointree, l);
728 504 : break;
729 : }
730 : }
731 : }
732 1356 : return newjointree;
733 : }
734 :
735 :
736 : /*
737 : * rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form
738 : *
739 : * This has the following responsibilities:
740 : *
741 : * 1. For an INSERT, add tlist entries to compute default values for any
742 : * attributes that have defaults and are not assigned to in the given tlist.
743 : * (We do not insert anything for default-less attributes, however. The
744 : * planner will later insert NULLs for them, but there's no reason to slow
745 : * down rewriter processing with extra tlist nodes.) Also, for both INSERT
746 : * and UPDATE, replace explicit DEFAULT specifications with column default
747 : * expressions.
748 : *
749 : * 2. Merge multiple entries for the same target attribute, or declare error
750 : * if we can't. Multiple entries are only allowed for INSERT/UPDATE of
751 : * portions of an array or record field, for example
752 : * UPDATE table SET foo[2] = 42, foo[4] = 43;
753 : * We can merge such operations into a single assignment op. Essentially,
754 : * the expression we want to produce in this case is like
755 : * foo = array_set_element(array_set_element(foo, 2, 42), 4, 43)
756 : *
757 : * 3. Sort the tlist into standard order: non-junk fields in order by resno,
758 : * then junk fields (these in no particular order).
759 : *
760 : * We must do items 1 and 2 before firing rewrite rules, else rewritten
761 : * references to NEW.foo will produce wrong or incomplete results. Item 3
762 : * is not needed for rewriting, but it is helpful for the planner, and we
763 : * can do it essentially for free while handling the other items.
764 : *
765 : * If values_rte is non-NULL (i.e., we are doing a multi-row INSERT using
766 : * values from a VALUES RTE), we populate *unused_values_attrnos with the
767 : * attribute numbers of any unused columns from the VALUES RTE. This can
768 : * happen for identity and generated columns whose targetlist entries are
769 : * replaced with generated expressions (if INSERT ... OVERRIDING USER VALUE is
770 : * used, or all the values to be inserted are DEFAULT). This information is
771 : * required by rewriteValuesRTE() to handle any DEFAULT items in the unused
772 : * columns. The caller must have initialized *unused_values_attrnos to NULL.
773 : */
774 : static List *
775 88942 : rewriteTargetListIU(List *targetList,
776 : CmdType commandType,
777 : OverridingKind override,
778 : Relation target_relation,
779 : RangeTblEntry *values_rte,
780 : int values_rte_index,
781 : Bitmapset **unused_values_attrnos)
782 : {
783 : TargetEntry **new_tles;
784 88942 : List *new_tlist = NIL;
785 88942 : List *junk_tlist = NIL;
786 : Form_pg_attribute att_tup;
787 : int attrno,
788 : next_junk_attrno,
789 : numattrs;
790 : ListCell *temp;
791 88942 : Bitmapset *default_only_cols = NULL;
792 :
793 : /*
794 : * We process the normal (non-junk) attributes by scanning the input tlist
795 : * once and transferring TLEs into an array, then scanning the array to
796 : * build an output tlist. This avoids O(N^2) behavior for large numbers
797 : * of attributes.
798 : *
799 : * Junk attributes are tossed into a separate list during the same tlist
800 : * scan, then appended to the reconstructed tlist.
801 : */
802 88942 : numattrs = RelationGetNumberOfAttributes(target_relation);
803 88942 : new_tles = (TargetEntry **) palloc0(numattrs * sizeof(TargetEntry *));
804 88942 : next_junk_attrno = numattrs + 1;
805 :
806 245162 : foreach(temp, targetList)
807 : {
808 156238 : TargetEntry *old_tle = (TargetEntry *) lfirst(temp);
809 :
810 156238 : if (!old_tle->resjunk)
811 : {
812 : /* Normal attr: stash it into new_tles[] */
813 156106 : attrno = old_tle->resno;
814 156106 : if (attrno < 1 || attrno > numattrs)
815 0 : elog(ERROR, "bogus resno %d in targetlist", attrno);
816 156106 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
817 :
818 : /* We can (and must) ignore deleted attributes */
819 156106 : if (att_tup->attisdropped)
820 0 : continue;
821 :
822 : /* Merge with any prior assignment to same attribute */
823 156088 : new_tles[attrno - 1] =
824 156106 : process_matched_tle(old_tle,
825 156106 : new_tles[attrno - 1],
826 156106 : NameStr(att_tup->attname));
827 : }
828 : else
829 : {
830 : /*
831 : * Copy all resjunk tlist entries to junk_tlist, and assign them
832 : * resnos above the last real resno.
833 : *
834 : * Typical junk entries include ORDER BY or GROUP BY expressions
835 : * (are these actually possible in an INSERT or UPDATE?), system
836 : * attribute references, etc.
837 : */
838 :
839 : /* Get the resno right, but don't copy unnecessarily */
840 132 : if (old_tle->resno != next_junk_attrno)
841 : {
842 0 : old_tle = flatCopyTargetEntry(old_tle);
843 0 : old_tle->resno = next_junk_attrno;
844 : }
845 132 : junk_tlist = lappend(junk_tlist, old_tle);
846 132 : next_junk_attrno++;
847 : }
848 : }
849 :
850 395188 : for (attrno = 1; attrno <= numattrs; attrno++)
851 : {
852 306462 : TargetEntry *new_tle = new_tles[attrno - 1];
853 : bool apply_default;
854 :
855 306462 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
856 :
857 : /* We can (and must) ignore deleted attributes */
858 306462 : if (att_tup->attisdropped)
859 968 : continue;
860 :
861 : /*
862 : * Handle the two cases where we need to insert a default expression:
863 : * it's an INSERT and there's no tlist entry for the column, or the
864 : * tlist entry is a DEFAULT placeholder node.
865 : */
866 461190 : apply_default = ((new_tle == NULL && commandType == CMD_INSERT) ||
867 155696 : (new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault)));
868 :
869 305494 : if (commandType == CMD_INSERT)
870 : {
871 158470 : int values_attrno = 0;
872 :
873 : /* Source attribute number for values that come from a VALUES RTE */
874 158470 : if (values_rte && new_tle && IsA(new_tle->expr, Var))
875 : {
876 8746 : Var *var = (Var *) new_tle->expr;
877 :
878 8746 : if (var->varno == values_rte_index)
879 8746 : values_attrno = var->varattno;
880 : }
881 :
882 : /*
883 : * Can only insert DEFAULT into GENERATED ALWAYS identity columns,
884 : * unless either OVERRIDING USER VALUE or OVERRIDING SYSTEM VALUE
885 : * is specified.
886 : */
887 158470 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS && !apply_default)
888 : {
889 140 : if (override == OVERRIDING_USER_VALUE)
890 42 : apply_default = true;
891 98 : else if (override != OVERRIDING_SYSTEM_VALUE)
892 : {
893 : /*
894 : * If this column's values come from a VALUES RTE, test
895 : * whether it contains only SetToDefault items. Since the
896 : * VALUES list might be quite large, we arrange to only
897 : * scan it once.
898 : */
899 50 : if (values_attrno != 0)
900 : {
901 26 : if (default_only_cols == NULL)
902 26 : default_only_cols = findDefaultOnlyColumns(values_rte);
903 :
904 26 : if (bms_is_member(values_attrno, default_only_cols))
905 8 : apply_default = true;
906 : }
907 :
908 50 : if (!apply_default)
909 42 : ereport(ERROR,
910 : (errcode(ERRCODE_GENERATED_ALWAYS),
911 : errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
912 : NameStr(att_tup->attname)),
913 : errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
914 : NameStr(att_tup->attname)),
915 : errhint("Use OVERRIDING SYSTEM VALUE to override.")));
916 : }
917 : }
918 :
919 : /*
920 : * Although inserting into a GENERATED BY DEFAULT identity column
921 : * is allowed, apply the default if OVERRIDING USER VALUE is
922 : * specified.
923 : */
924 158428 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_BY_DEFAULT &&
925 : override == OVERRIDING_USER_VALUE)
926 18 : apply_default = true;
927 :
928 : /*
929 : * Can only insert DEFAULT into generated columns. (The
930 : * OVERRIDING clause does not apply to generated columns, so we
931 : * don't consider it here.)
932 : */
933 158428 : if (att_tup->attgenerated && !apply_default)
934 : {
935 : /*
936 : * If this column's values come from a VALUES RTE, test
937 : * whether it contains only SetToDefault items, as above.
938 : */
939 170 : if (values_attrno != 0)
940 : {
941 116 : if (default_only_cols == NULL)
942 116 : default_only_cols = findDefaultOnlyColumns(values_rte);
943 :
944 116 : if (bms_is_member(values_attrno, default_only_cols))
945 32 : apply_default = true;
946 : }
947 :
948 170 : if (!apply_default)
949 138 : ereport(ERROR,
950 : (errcode(ERRCODE_GENERATED_ALWAYS),
951 : errmsg("cannot insert a non-DEFAULT value into column \"%s\"",
952 : NameStr(att_tup->attname)),
953 : errdetail("Column \"%s\" is a generated column.",
954 : NameStr(att_tup->attname))));
955 : }
956 :
957 : /*
958 : * For an INSERT from a VALUES RTE, return the attribute numbers
959 : * of any VALUES columns that will no longer be used (due to the
960 : * targetlist entry being replaced by a default expression).
961 : */
962 158290 : if (values_attrno != 0 && apply_default && unused_values_attrnos)
963 64 : *unused_values_attrnos = bms_add_member(*unused_values_attrnos,
964 : values_attrno);
965 : }
966 :
967 : /*
968 : * Updates to identity and generated columns follow the same rules as
969 : * above, except that UPDATE doesn't admit OVERRIDING clauses. Also,
970 : * the source can't be a VALUES RTE, so we needn't consider that.
971 : */
972 305314 : if (commandType == CMD_UPDATE)
973 : {
974 147024 : if (att_tup->attidentity == ATTRIBUTE_IDENTITY_ALWAYS &&
975 12 : new_tle && !apply_default)
976 6 : ereport(ERROR,
977 : (errcode(ERRCODE_GENERATED_ALWAYS),
978 : errmsg("column \"%s\" can only be updated to DEFAULT",
979 : NameStr(att_tup->attname)),
980 : errdetail("Column \"%s\" is an identity column defined as GENERATED ALWAYS.",
981 : NameStr(att_tup->attname))));
982 :
983 147018 : if (att_tup->attgenerated && new_tle && !apply_default)
984 12 : ereport(ERROR,
985 : (errcode(ERRCODE_GENERATED_ALWAYS),
986 : errmsg("column \"%s\" can only be updated to DEFAULT",
987 : NameStr(att_tup->attname)),
988 : errdetail("Column \"%s\" is a generated column.",
989 : NameStr(att_tup->attname))));
990 : }
991 :
992 305296 : if (att_tup->attgenerated)
993 : {
994 : /*
995 : * virtual generated column stores a null value; stored generated
996 : * column will be fixed in executor
997 : */
998 1624 : new_tle = NULL;
999 : }
1000 303672 : else if (apply_default)
1001 : {
1002 : Node *new_expr;
1003 :
1004 25578 : new_expr = build_column_default(target_relation, attrno);
1005 :
1006 : /*
1007 : * If there is no default (ie, default is effectively NULL), we
1008 : * can omit the tlist entry in the INSERT case, since the planner
1009 : * can insert a NULL for itself, and there's no point in spending
1010 : * any more rewriter cycles on the entry. But in the UPDATE case
1011 : * we've got to explicitly set the column to NULL.
1012 : */
1013 25578 : if (!new_expr)
1014 : {
1015 18932 : if (commandType == CMD_INSERT)
1016 18912 : new_tle = NULL;
1017 : else
1018 20 : new_expr = coerce_null_to_domain(att_tup->atttypid,
1019 : att_tup->atttypmod,
1020 : att_tup->attcollation,
1021 20 : att_tup->attlen,
1022 20 : att_tup->attbyval);
1023 : }
1024 :
1025 25578 : if (new_expr)
1026 6666 : new_tle = makeTargetEntry((Expr *) new_expr,
1027 : attrno,
1028 6666 : pstrdup(NameStr(att_tup->attname)),
1029 : false);
1030 : }
1031 :
1032 305296 : if (new_tle)
1033 161382 : new_tlist = lappend(new_tlist, new_tle);
1034 : }
1035 :
1036 88726 : pfree(new_tles);
1037 :
1038 88726 : return list_concat(new_tlist, junk_tlist);
1039 : }
1040 :
1041 :
1042 : /*
1043 : * Convert a matched TLE from the original tlist into a correct new TLE.
1044 : *
1045 : * This routine detects and handles multiple assignments to the same target
1046 : * attribute. (The attribute name is needed only for error messages.)
1047 : */
1048 : static TargetEntry *
1049 156106 : process_matched_tle(TargetEntry *src_tle,
1050 : TargetEntry *prior_tle,
1051 : const char *attrName)
1052 : {
1053 : TargetEntry *result;
1054 156106 : CoerceToDomain *coerce_expr = NULL;
1055 : Node *src_expr;
1056 : Node *prior_expr;
1057 : Node *src_input;
1058 : Node *prior_input;
1059 : Node *priorbottom;
1060 : Node *newexpr;
1061 :
1062 156106 : if (prior_tle == NULL)
1063 : {
1064 : /*
1065 : * Normal case where this is the first assignment to the attribute.
1066 : */
1067 155768 : return src_tle;
1068 : }
1069 :
1070 : /*----------
1071 : * Multiple assignments to same attribute. Allow only if all are
1072 : * FieldStore or SubscriptingRef assignment operations. This is a bit
1073 : * tricky because what we may actually be looking at is a nest of
1074 : * such nodes; consider
1075 : * UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y
1076 : * The two expressions produced by the parser will look like
1077 : * FieldStore(col, fld1, FieldStore(placeholder, subfld1, x))
1078 : * FieldStore(col, fld2, FieldStore(placeholder, subfld2, y))
1079 : * However, we can ignore the substructure and just consider the top
1080 : * FieldStore or SubscriptingRef from each assignment, because it works to
1081 : * combine these as
1082 : * FieldStore(FieldStore(col, fld1,
1083 : * FieldStore(placeholder, subfld1, x)),
1084 : * fld2, FieldStore(placeholder, subfld2, y))
1085 : * Note the leftmost expression goes on the inside so that the
1086 : * assignments appear to occur left-to-right.
1087 : *
1088 : * For FieldStore, instead of nesting we can generate a single
1089 : * FieldStore with multiple target fields. We must nest when
1090 : * SubscriptingRefs are involved though.
1091 : *
1092 : * As a further complication, the destination column might be a domain,
1093 : * resulting in each assignment containing a CoerceToDomain node over a
1094 : * FieldStore or SubscriptingRef. These should have matching target
1095 : * domains, so we strip them and reconstitute a single CoerceToDomain over
1096 : * the combined FieldStore/SubscriptingRef nodes. (Notice that this has
1097 : * the result that the domain's checks are applied only after we do all
1098 : * the field or element updates, not after each one. This is desirable.)
1099 : *----------
1100 : */
1101 338 : src_expr = (Node *) src_tle->expr;
1102 338 : prior_expr = (Node *) prior_tle->expr;
1103 :
1104 338 : if (src_expr && IsA(src_expr, CoerceToDomain) &&
1105 162 : prior_expr && IsA(prior_expr, CoerceToDomain) &&
1106 162 : ((CoerceToDomain *) src_expr)->resulttype ==
1107 162 : ((CoerceToDomain *) prior_expr)->resulttype)
1108 : {
1109 : /* we assume without checking that resulttypmod/resultcollid match */
1110 162 : coerce_expr = (CoerceToDomain *) src_expr;
1111 162 : src_expr = (Node *) ((CoerceToDomain *) src_expr)->arg;
1112 162 : prior_expr = (Node *) ((CoerceToDomain *) prior_expr)->arg;
1113 : }
1114 :
1115 338 : src_input = get_assignment_input(src_expr);
1116 338 : prior_input = get_assignment_input(prior_expr);
1117 338 : if (src_input == NULL ||
1118 320 : prior_input == NULL ||
1119 320 : exprType(src_expr) != exprType(prior_expr))
1120 18 : ereport(ERROR,
1121 : (errcode(ERRCODE_SYNTAX_ERROR),
1122 : errmsg("multiple assignments to same column \"%s\"",
1123 : attrName)));
1124 :
1125 : /*
1126 : * Prior TLE could be a nest of assignments if we do this more than once.
1127 : */
1128 320 : priorbottom = prior_input;
1129 : for (;;)
1130 42 : {
1131 362 : Node *newbottom = get_assignment_input(priorbottom);
1132 :
1133 362 : if (newbottom == NULL)
1134 320 : break; /* found the original Var reference */
1135 42 : priorbottom = newbottom;
1136 : }
1137 320 : if (!equal(priorbottom, src_input))
1138 0 : ereport(ERROR,
1139 : (errcode(ERRCODE_SYNTAX_ERROR),
1140 : errmsg("multiple assignments to same column \"%s\"",
1141 : attrName)));
1142 :
1143 : /*
1144 : * Looks OK to nest 'em.
1145 : */
1146 320 : if (IsA(src_expr, FieldStore))
1147 : {
1148 126 : FieldStore *fstore = makeNode(FieldStore);
1149 :
1150 126 : if (IsA(prior_expr, FieldStore))
1151 : {
1152 : /* combine the two */
1153 126 : memcpy(fstore, prior_expr, sizeof(FieldStore));
1154 126 : fstore->newvals =
1155 126 : list_concat_copy(((FieldStore *) prior_expr)->newvals,
1156 126 : ((FieldStore *) src_expr)->newvals);
1157 126 : fstore->fieldnums =
1158 126 : list_concat_copy(((FieldStore *) prior_expr)->fieldnums,
1159 126 : ((FieldStore *) src_expr)->fieldnums);
1160 : }
1161 : else
1162 : {
1163 : /* general case, just nest 'em */
1164 0 : memcpy(fstore, src_expr, sizeof(FieldStore));
1165 0 : fstore->arg = (Expr *) prior_expr;
1166 : }
1167 126 : newexpr = (Node *) fstore;
1168 : }
1169 194 : else if (IsA(src_expr, SubscriptingRef))
1170 : {
1171 194 : SubscriptingRef *sbsref = makeNode(SubscriptingRef);
1172 :
1173 194 : memcpy(sbsref, src_expr, sizeof(SubscriptingRef));
1174 194 : sbsref->refexpr = (Expr *) prior_expr;
1175 194 : newexpr = (Node *) sbsref;
1176 : }
1177 : else
1178 : {
1179 0 : elog(ERROR, "cannot happen");
1180 : newexpr = NULL;
1181 : }
1182 :
1183 320 : if (coerce_expr)
1184 : {
1185 : /* put back the CoerceToDomain */
1186 162 : CoerceToDomain *newcoerce = makeNode(CoerceToDomain);
1187 :
1188 162 : memcpy(newcoerce, coerce_expr, sizeof(CoerceToDomain));
1189 162 : newcoerce->arg = (Expr *) newexpr;
1190 162 : newexpr = (Node *) newcoerce;
1191 : }
1192 :
1193 320 : result = flatCopyTargetEntry(src_tle);
1194 320 : result->expr = (Expr *) newexpr;
1195 320 : return result;
1196 : }
1197 :
1198 : /*
1199 : * If node is an assignment node, return its input; else return NULL
1200 : */
1201 : static Node *
1202 1038 : get_assignment_input(Node *node)
1203 : {
1204 1038 : if (node == NULL)
1205 0 : return NULL;
1206 1038 : if (IsA(node, FieldStore))
1207 : {
1208 252 : FieldStore *fstore = (FieldStore *) node;
1209 :
1210 252 : return (Node *) fstore->arg;
1211 : }
1212 786 : else if (IsA(node, SubscriptingRef))
1213 : {
1214 430 : SubscriptingRef *sbsref = (SubscriptingRef *) node;
1215 :
1216 430 : if (sbsref->refassgnexpr == NULL)
1217 0 : return NULL;
1218 :
1219 430 : return (Node *) sbsref->refexpr;
1220 : }
1221 :
1222 356 : return NULL;
1223 : }
1224 :
1225 : /*
1226 : * Make an expression tree for the default value for a column.
1227 : *
1228 : * If there is no default, return a NULL instead.
1229 : */
1230 : Node *
1231 188964 : build_column_default(Relation rel, int attrno)
1232 : {
1233 188964 : TupleDesc rd_att = rel->rd_att;
1234 188964 : Form_pg_attribute att_tup = TupleDescAttr(rd_att, attrno - 1);
1235 188964 : Oid atttype = att_tup->atttypid;
1236 188964 : int32 atttypmod = att_tup->atttypmod;
1237 188964 : Node *expr = NULL;
1238 : Oid exprtype;
1239 :
1240 188964 : if (att_tup->attidentity)
1241 : {
1242 484 : NextValueExpr *nve = makeNode(NextValueExpr);
1243 :
1244 484 : nve->seqid = getIdentitySequence(rel, attrno, false);
1245 484 : nve->typeId = att_tup->atttypid;
1246 :
1247 484 : return (Node *) nve;
1248 : }
1249 :
1250 : /*
1251 : * If relation has a default for this column, fetch that expression.
1252 : */
1253 188480 : if (att_tup->atthasdef)
1254 : {
1255 150858 : expr = TupleDescGetDefault(rd_att, attrno);
1256 150858 : if (expr == NULL)
1257 0 : elog(ERROR, "default expression not found for attribute %d of relation \"%s\"",
1258 : attrno, RelationGetRelationName(rel));
1259 : }
1260 :
1261 : /*
1262 : * No per-column default, so look for a default for the type itself. But
1263 : * not for generated columns.
1264 : */
1265 188480 : if (expr == NULL && !att_tup->attgenerated)
1266 37622 : expr = get_typdefault(atttype);
1267 :
1268 188480 : if (expr == NULL)
1269 37392 : return NULL; /* No default anywhere */
1270 :
1271 : /*
1272 : * Make sure the value is coerced to the target column type; this will
1273 : * generally be true already, but there seem to be some corner cases
1274 : * involving domain defaults where it might not be true. This should match
1275 : * the parser's processing of non-defaulted expressions --- see
1276 : * transformAssignedExpr().
1277 : */
1278 151088 : exprtype = exprType(expr);
1279 :
1280 151088 : expr = coerce_to_target_type(NULL, /* no UNKNOWN params here */
1281 : expr, exprtype,
1282 : atttype, atttypmod,
1283 : COERCION_ASSIGNMENT,
1284 : COERCE_IMPLICIT_CAST,
1285 : -1);
1286 151088 : if (expr == NULL)
1287 0 : ereport(ERROR,
1288 : (errcode(ERRCODE_DATATYPE_MISMATCH),
1289 : errmsg("column \"%s\" is of type %s"
1290 : " but default expression is of type %s",
1291 : NameStr(att_tup->attname),
1292 : format_type_be(atttype),
1293 : format_type_be(exprtype)),
1294 : errhint("You will need to rewrite or cast the expression.")));
1295 :
1296 151088 : return expr;
1297 : }
1298 :
1299 :
1300 : /* Does VALUES RTE contain any SetToDefault items? */
1301 : static bool
1302 4798 : searchForDefault(RangeTblEntry *rte)
1303 : {
1304 : ListCell *lc;
1305 :
1306 19636 : foreach(lc, rte->values_lists)
1307 : {
1308 15142 : List *sublist = (List *) lfirst(lc);
1309 : ListCell *lc2;
1310 :
1311 44112 : foreach(lc2, sublist)
1312 : {
1313 29274 : Node *col = (Node *) lfirst(lc2);
1314 :
1315 29274 : if (IsA(col, SetToDefault))
1316 304 : return true;
1317 : }
1318 : }
1319 4494 : return false;
1320 : }
1321 :
1322 :
1323 : /*
1324 : * Search a VALUES RTE for columns that contain only SetToDefault items,
1325 : * returning a Bitmapset containing the attribute numbers of any such columns.
1326 : */
1327 : static Bitmapset *
1328 142 : findDefaultOnlyColumns(RangeTblEntry *rte)
1329 : {
1330 142 : Bitmapset *default_only_cols = NULL;
1331 : ListCell *lc;
1332 :
1333 258 : foreach(lc, rte->values_lists)
1334 : {
1335 218 : List *sublist = (List *) lfirst(lc);
1336 : ListCell *lc2;
1337 : int i;
1338 :
1339 218 : if (default_only_cols == NULL)
1340 : {
1341 : /* Populate the initial result bitmap from the first row */
1342 142 : i = 0;
1343 434 : foreach(lc2, sublist)
1344 : {
1345 292 : Node *col = (Node *) lfirst(lc2);
1346 :
1347 292 : i++;
1348 292 : if (IsA(col, SetToDefault))
1349 72 : default_only_cols = bms_add_member(default_only_cols, i);
1350 : }
1351 : }
1352 : else
1353 : {
1354 : /* Update the result bitmap from this next row */
1355 76 : i = 0;
1356 242 : foreach(lc2, sublist)
1357 : {
1358 166 : Node *col = (Node *) lfirst(lc2);
1359 :
1360 166 : i++;
1361 166 : if (!IsA(col, SetToDefault))
1362 118 : default_only_cols = bms_del_member(default_only_cols, i);
1363 : }
1364 : }
1365 :
1366 : /*
1367 : * If no column in the rows read so far contains only DEFAULT items,
1368 : * we are done.
1369 : */
1370 218 : if (bms_is_empty(default_only_cols))
1371 102 : break;
1372 : }
1373 :
1374 142 : return default_only_cols;
1375 : }
1376 :
1377 :
1378 : /*
1379 : * When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES
1380 : * lists), we have to replace any DEFAULT items in the VALUES lists with
1381 : * the appropriate default expressions. The other aspects of targetlist
1382 : * rewriting need be applied only to the query's targetlist proper.
1383 : *
1384 : * For an auto-updatable view, each DEFAULT item in the VALUES list is
1385 : * replaced with the default from the view, if it has one. Otherwise it is
1386 : * left untouched so that the underlying base relation's default can be
1387 : * applied instead (when we later recurse to here after rewriting the query
1388 : * to refer to the base relation instead of the view).
1389 : *
1390 : * For other types of relation, including rule- and trigger-updatable views,
1391 : * all DEFAULT items are replaced, and if the target relation doesn't have a
1392 : * default, the value is explicitly set to NULL.
1393 : *
1394 : * Also, if a DEFAULT item is found in a column mentioned in unused_cols,
1395 : * it is explicitly set to NULL. This happens for columns in the VALUES RTE
1396 : * whose corresponding targetlist entries have already been replaced with the
1397 : * relation's default expressions, so that any values in those columns of the
1398 : * VALUES RTE are no longer used. This can happen for identity and generated
1399 : * columns (if INSERT ... OVERRIDING USER VALUE is used, or all the values to
1400 : * be inserted are DEFAULT). In principle we could replace all entries in
1401 : * such a column with NULL, whether DEFAULT or not; but it doesn't seem worth
1402 : * the trouble.
1403 : *
1404 : * Note that we may have subscripted or field assignment targetlist entries,
1405 : * as well as more complex expressions from already-replaced DEFAULT items if
1406 : * we have recursed to here for an auto-updatable view. However, it ought to
1407 : * be impossible for such entries to have DEFAULTs assigned to them, except
1408 : * for unused columns, as described above --- we should only have to replace
1409 : * DEFAULT items for targetlist entries that contain simple Vars referencing
1410 : * the VALUES RTE, or which are no longer referred to by the targetlist.
1411 : *
1412 : * Returns true if all DEFAULT items were replaced, and false if some were
1413 : * left untouched.
1414 : */
1415 : static bool
1416 4798 : rewriteValuesRTE(Query *parsetree, RangeTblEntry *rte, int rti,
1417 : Relation target_relation,
1418 : Bitmapset *unused_cols)
1419 : {
1420 : List *newValues;
1421 : ListCell *lc;
1422 : bool isAutoUpdatableView;
1423 : bool allReplaced;
1424 : int numattrs;
1425 : int *attrnos;
1426 :
1427 : /* Steps below are not sensible for non-INSERT queries */
1428 : Assert(parsetree->commandType == CMD_INSERT);
1429 : Assert(rte->rtekind == RTE_VALUES);
1430 :
1431 : /*
1432 : * Rebuilding all the lists is a pretty expensive proposition in a big
1433 : * VALUES list, and it's a waste of time if there aren't any DEFAULT
1434 : * placeholders. So first scan to see if there are any.
1435 : */
1436 4798 : if (!searchForDefault(rte))
1437 4494 : return true; /* nothing to do */
1438 :
1439 : /*
1440 : * Scan the targetlist for entries referring to the VALUES RTE, and note
1441 : * the target attributes. As noted above, we should only need to do this
1442 : * for targetlist entries containing simple Vars --- nothing else in the
1443 : * VALUES RTE should contain DEFAULT items (except possibly for unused
1444 : * columns), and we complain if such a thing does occur.
1445 : */
1446 304 : numattrs = list_length(linitial(rte->values_lists));
1447 304 : attrnos = (int *) palloc0(numattrs * sizeof(int));
1448 :
1449 1230 : foreach(lc, parsetree->targetList)
1450 : {
1451 926 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
1452 :
1453 926 : if (IsA(tle->expr, Var))
1454 : {
1455 792 : Var *var = (Var *) tle->expr;
1456 :
1457 792 : if (var->varno == rti)
1458 : {
1459 792 : int attrno = var->varattno;
1460 :
1461 : Assert(attrno >= 1 && attrno <= numattrs);
1462 792 : attrnos[attrno - 1] = tle->resno;
1463 : }
1464 : }
1465 : }
1466 :
1467 : /*
1468 : * Check if the target relation is an auto-updatable view, in which case
1469 : * unresolved defaults will be left untouched rather than being set to
1470 : * NULL.
1471 : */
1472 304 : isAutoUpdatableView = false;
1473 304 : if (target_relation->rd_rel->relkind == RELKIND_VIEW &&
1474 114 : !view_has_instead_trigger(target_relation, CMD_INSERT, NIL))
1475 : {
1476 : List *locks;
1477 : bool hasUpdate;
1478 : bool found;
1479 : ListCell *l;
1480 :
1481 : /* Look for an unconditional DO INSTEAD rule */
1482 102 : locks = matchLocks(CMD_INSERT, target_relation,
1483 : parsetree->resultRelation, parsetree, &hasUpdate);
1484 :
1485 102 : found = false;
1486 126 : foreach(l, locks)
1487 : {
1488 36 : RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
1489 :
1490 36 : if (rule_lock->isInstead &&
1491 12 : rule_lock->qual == NULL)
1492 : {
1493 12 : found = true;
1494 12 : break;
1495 : }
1496 : }
1497 :
1498 : /*
1499 : * If we didn't find an unconditional DO INSTEAD rule, assume that the
1500 : * view is auto-updatable. If it isn't, rewriteTargetView() will
1501 : * throw an error.
1502 : */
1503 102 : if (!found)
1504 90 : isAutoUpdatableView = true;
1505 : }
1506 :
1507 304 : newValues = NIL;
1508 304 : allReplaced = true;
1509 930 : foreach(lc, rte->values_lists)
1510 : {
1511 626 : List *sublist = (List *) lfirst(lc);
1512 626 : List *newList = NIL;
1513 : ListCell *lc2;
1514 : int i;
1515 :
1516 : Assert(list_length(sublist) == numattrs);
1517 :
1518 626 : i = 0;
1519 2494 : foreach(lc2, sublist)
1520 : {
1521 1868 : Node *col = (Node *) lfirst(lc2);
1522 1868 : int attrno = attrnos[i++];
1523 :
1524 1868 : if (IsA(col, SetToDefault))
1525 : {
1526 : Form_pg_attribute att_tup;
1527 : Node *new_expr;
1528 :
1529 : /*
1530 : * If this column isn't used, just replace the DEFAULT with
1531 : * NULL (attrno will be 0 in this case because the targetlist
1532 : * entry will have been replaced by the default expression).
1533 : */
1534 870 : if (bms_is_member(i, unused_cols))
1535 110 : {
1536 110 : SetToDefault *def = (SetToDefault *) col;
1537 :
1538 110 : newList = lappend(newList,
1539 110 : makeNullConst(def->typeId,
1540 : def->typeMod,
1541 : def->collation));
1542 110 : continue;
1543 : }
1544 :
1545 760 : if (attrno == 0)
1546 0 : elog(ERROR, "cannot set value in column %d to DEFAULT", i);
1547 : Assert(attrno > 0 && attrno <= target_relation->rd_att->natts);
1548 760 : att_tup = TupleDescAttr(target_relation->rd_att, attrno - 1);
1549 :
1550 760 : if (!att_tup->attisdropped)
1551 760 : new_expr = build_column_default(target_relation, attrno);
1552 : else
1553 0 : new_expr = NULL; /* force a NULL if dropped */
1554 :
1555 : /*
1556 : * If there is no default (ie, default is effectively NULL),
1557 : * we've got to explicitly set the column to NULL, unless the
1558 : * target relation is an auto-updatable view.
1559 : */
1560 760 : if (!new_expr)
1561 : {
1562 358 : if (isAutoUpdatableView)
1563 : {
1564 : /* Leave the value untouched */
1565 150 : newList = lappend(newList, col);
1566 150 : allReplaced = false;
1567 150 : continue;
1568 : }
1569 :
1570 208 : new_expr = coerce_null_to_domain(att_tup->atttypid,
1571 : att_tup->atttypmod,
1572 : att_tup->attcollation,
1573 208 : att_tup->attlen,
1574 208 : att_tup->attbyval);
1575 : }
1576 610 : newList = lappend(newList, new_expr);
1577 : }
1578 : else
1579 998 : newList = lappend(newList, col);
1580 : }
1581 626 : newValues = lappend(newValues, newList);
1582 : }
1583 304 : rte->values_lists = newValues;
1584 :
1585 304 : pfree(attrnos);
1586 :
1587 304 : return allReplaced;
1588 : }
1589 :
1590 : /*
1591 : * Mop up any remaining DEFAULT items in the given VALUES RTE by
1592 : * replacing them with NULL constants.
1593 : *
1594 : * This is used for the product queries generated by DO ALSO rules attached to
1595 : * an auto-updatable view. The action can't depend on the "target relation"
1596 : * since the product query might not have one (it needn't be an INSERT).
1597 : * Essentially, such queries are treated as being attached to a rule-updatable
1598 : * view.
1599 : */
1600 : static void
1601 24 : rewriteValuesRTEToNulls(Query *parsetree, RangeTblEntry *rte)
1602 : {
1603 : List *newValues;
1604 : ListCell *lc;
1605 :
1606 24 : newValues = NIL;
1607 72 : foreach(lc, rte->values_lists)
1608 : {
1609 48 : List *sublist = (List *) lfirst(lc);
1610 48 : List *newList = NIL;
1611 : ListCell *lc2;
1612 :
1613 204 : foreach(lc2, sublist)
1614 : {
1615 156 : Node *col = (Node *) lfirst(lc2);
1616 :
1617 156 : if (IsA(col, SetToDefault))
1618 : {
1619 66 : SetToDefault *def = (SetToDefault *) col;
1620 :
1621 66 : newList = lappend(newList, makeNullConst(def->typeId,
1622 : def->typeMod,
1623 : def->collation));
1624 : }
1625 : else
1626 90 : newList = lappend(newList, col);
1627 : }
1628 48 : newValues = lappend(newValues, newList);
1629 : }
1630 24 : rte->values_lists = newValues;
1631 24 : }
1632 :
1633 :
1634 : /*
1635 : * matchLocks -
1636 : * match a relation's list of locks and returns the matching rules
1637 : */
1638 : static List *
1639 91600 : matchLocks(CmdType event,
1640 : Relation relation,
1641 : int varno,
1642 : Query *parsetree,
1643 : bool *hasUpdate)
1644 : {
1645 91600 : RuleLock *rulelocks = relation->rd_rules;
1646 91600 : List *matching_locks = NIL;
1647 : int nlocks;
1648 : int i;
1649 :
1650 91600 : if (rulelocks == NULL)
1651 85904 : return NIL;
1652 :
1653 5696 : if (parsetree->commandType != CMD_SELECT)
1654 : {
1655 5696 : if (parsetree->resultRelation != varno)
1656 0 : return NIL;
1657 : }
1658 :
1659 5696 : nlocks = rulelocks->numLocks;
1660 :
1661 13012 : for (i = 0; i < nlocks; i++)
1662 : {
1663 7334 : RewriteRule *oneLock = rulelocks->rules[i];
1664 :
1665 7334 : if (oneLock->event == CMD_UPDATE)
1666 660 : *hasUpdate = true;
1667 :
1668 : /*
1669 : * Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
1670 : * configured to not fire during the current session's replication
1671 : * role. ON SELECT rules will always be applied in order to keep views
1672 : * working even in LOCAL or REPLICA role.
1673 : */
1674 7334 : if (oneLock->event != CMD_SELECT)
1675 : {
1676 2724 : if (SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA)
1677 : {
1678 12 : if (oneLock->enabled == RULE_FIRES_ON_ORIGIN ||
1679 6 : oneLock->enabled == RULE_DISABLED)
1680 6 : continue;
1681 : }
1682 : else /* ORIGIN or LOCAL ROLE */
1683 : {
1684 2712 : if (oneLock->enabled == RULE_FIRES_ON_REPLICA ||
1685 2706 : oneLock->enabled == RULE_DISABLED)
1686 30 : continue;
1687 : }
1688 :
1689 : /* Non-SELECT rules are not supported for MERGE */
1690 2688 : if (parsetree->commandType == CMD_MERGE)
1691 18 : ereport(ERROR,
1692 : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1693 : errmsg("cannot execute MERGE on relation \"%s\"",
1694 : RelationGetRelationName(relation)),
1695 : errdetail("MERGE is not supported for relations with rules."));
1696 : }
1697 :
1698 7280 : if (oneLock->event == event)
1699 : {
1700 1578 : if (parsetree->commandType != CMD_SELECT ||
1701 0 : rangeTableEntry_used((Node *) parsetree, varno, 0))
1702 1578 : matching_locks = lappend(matching_locks, oneLock);
1703 : }
1704 : }
1705 :
1706 5678 : return matching_locks;
1707 : }
1708 :
1709 :
1710 : /*
1711 : * ApplyRetrieveRule - expand an ON SELECT rule
1712 : */
1713 : static Query *
1714 16388 : ApplyRetrieveRule(Query *parsetree,
1715 : RewriteRule *rule,
1716 : int rt_index,
1717 : Relation relation,
1718 : List *activeRIRs)
1719 : {
1720 : Query *rule_action;
1721 : RangeTblEntry *rte;
1722 : RowMarkClause *rc;
1723 : int numCols;
1724 :
1725 16388 : if (list_length(rule->actions) != 1)
1726 0 : elog(ERROR, "expected just one rule action");
1727 16388 : if (rule->qual != NULL)
1728 0 : elog(ERROR, "cannot handle qualified ON SELECT rule");
1729 :
1730 : /* Check if the expansion of non-system views are restricted */
1731 16388 : if (unlikely((restrict_nonsystem_relation_kind & RESTRICT_RELKIND_VIEW) != 0 &&
1732 : RelationGetRelid(relation) >= FirstNormalObjectId))
1733 6 : ereport(ERROR,
1734 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1735 : errmsg("access to non-system view \"%s\" is restricted",
1736 : RelationGetRelationName(relation))));
1737 :
1738 16382 : if (rt_index == parsetree->resultRelation)
1739 : {
1740 : /*
1741 : * We have a view as the result relation of the query, and it wasn't
1742 : * rewritten by any rule. This case is supported if there is an
1743 : * INSTEAD OF trigger that will trap attempts to insert/update/delete
1744 : * view rows. The executor will check that; for the moment just plow
1745 : * ahead. We have two cases:
1746 : *
1747 : * For INSERT, we needn't do anything. The unmodified RTE will serve
1748 : * fine as the result relation.
1749 : *
1750 : * For UPDATE/DELETE/MERGE, we need to expand the view so as to have
1751 : * source data for the operation. But we also need an unmodified RTE
1752 : * to serve as the target. So, copy the RTE and add the copy to the
1753 : * rangetable. Note that the copy does not get added to the jointree.
1754 : * Also note that there's a hack in fireRIRrules to avoid calling this
1755 : * function again when it arrives at the copied RTE.
1756 : */
1757 408 : if (parsetree->commandType == CMD_INSERT)
1758 120 : return parsetree;
1759 288 : else if (parsetree->commandType == CMD_UPDATE ||
1760 132 : parsetree->commandType == CMD_DELETE ||
1761 78 : parsetree->commandType == CMD_MERGE)
1762 288 : {
1763 : RangeTblEntry *newrte;
1764 : Var *var;
1765 : TargetEntry *tle;
1766 :
1767 288 : rte = rt_fetch(rt_index, parsetree->rtable);
1768 288 : newrte = copyObject(rte);
1769 288 : parsetree->rtable = lappend(parsetree->rtable, newrte);
1770 288 : parsetree->resultRelation = list_length(parsetree->rtable);
1771 : /* parsetree->mergeTargetRelation unchanged (use expanded view) */
1772 :
1773 : /*
1774 : * For the most part, Vars referencing the view should remain as
1775 : * they are, meaning that they implicitly represent OLD values.
1776 : * But in the RETURNING list if any, we want such Vars to
1777 : * represent NEW values, so change them to reference the new RTE.
1778 : *
1779 : * Since ChangeVarNodes scribbles on the tree in-place, copy the
1780 : * RETURNING list first for safety.
1781 : */
1782 288 : parsetree->returningList = copyObject(parsetree->returningList);
1783 288 : ChangeVarNodes((Node *) parsetree->returningList, rt_index,
1784 : parsetree->resultRelation, 0);
1785 :
1786 : /*
1787 : * To allow the executor to compute the original view row to pass
1788 : * to the INSTEAD OF trigger, we add a resjunk whole-row Var
1789 : * referencing the original RTE. This will later get expanded
1790 : * into a RowExpr computing all the OLD values of the view row.
1791 : */
1792 288 : var = makeWholeRowVar(rte, rt_index, 0, false);
1793 288 : tle = makeTargetEntry((Expr *) var,
1794 288 : list_length(parsetree->targetList) + 1,
1795 : pstrdup("wholerow"),
1796 : true);
1797 :
1798 288 : parsetree->targetList = lappend(parsetree->targetList, tle);
1799 :
1800 : /* Now, continue with expanding the original view RTE */
1801 : }
1802 : else
1803 0 : elog(ERROR, "unrecognized commandType: %d",
1804 : (int) parsetree->commandType);
1805 : }
1806 :
1807 : /*
1808 : * Check if there's a FOR [KEY] UPDATE/SHARE clause applying to this view.
1809 : *
1810 : * Note: we needn't explicitly consider any such clauses appearing in
1811 : * ancestor query levels; their effects have already been pushed down to
1812 : * here by markQueryForLocking, and will be reflected in "rc".
1813 : */
1814 16262 : rc = get_parse_rowmark(parsetree, rt_index);
1815 :
1816 : /*
1817 : * Make a modifiable copy of the view query, and acquire needed locks on
1818 : * the relations it mentions. Force at least RowShareLock for all such
1819 : * rels if there's a FOR [KEY] UPDATE/SHARE clause affecting this view.
1820 : */
1821 16262 : rule_action = copyObject(linitial(rule->actions));
1822 :
1823 16262 : AcquireRewriteLocks(rule_action, true, (rc != NULL));
1824 :
1825 : /*
1826 : * If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as
1827 : * implicit FOR [KEY] UPDATE/SHARE, the same as the parser would have done
1828 : * if the view's subquery had been written out explicitly.
1829 : */
1830 16262 : if (rc != NULL)
1831 96 : markQueryForLocking(rule_action, (Node *) rule_action->jointree,
1832 : rc->strength, rc->waitPolicy, true);
1833 :
1834 : /*
1835 : * Recursively expand any view references inside the view.
1836 : */
1837 16262 : rule_action = fireRIRrules(rule_action, activeRIRs);
1838 :
1839 : /*
1840 : * Make sure the query is marked as having row security if the view query
1841 : * does.
1842 : */
1843 16232 : parsetree->hasRowSecurity |= rule_action->hasRowSecurity;
1844 :
1845 : /*
1846 : * Now, plug the view query in as a subselect, converting the relation's
1847 : * original RTE to a subquery RTE.
1848 : */
1849 16232 : rte = rt_fetch(rt_index, parsetree->rtable);
1850 :
1851 16232 : rte->rtekind = RTE_SUBQUERY;
1852 16232 : rte->subquery = rule_action;
1853 16232 : rte->security_barrier = RelationIsSecurityView(relation);
1854 :
1855 : /*
1856 : * Clear fields that should not be set in a subquery RTE. Note that we
1857 : * leave the relid, relkind, rellockmode, and perminfoindex fields set, so
1858 : * that the view relation can be appropriately locked before execution and
1859 : * its permissions checked.
1860 : */
1861 16232 : rte->tablesample = NULL;
1862 16232 : rte->inh = false; /* must not be set for a subquery */
1863 :
1864 : /*
1865 : * Since we allow CREATE OR REPLACE VIEW to add columns to a view, the
1866 : * rule_action might emit more columns than we expected when the current
1867 : * query was parsed. Various places expect rte->eref->colnames to be
1868 : * consistent with the non-junk output columns of the subquery, so patch
1869 : * things up if necessary by adding some dummy column names.
1870 : */
1871 16232 : numCols = ExecCleanTargetListLength(rule_action->targetList);
1872 16250 : while (list_length(rte->eref->colnames) < numCols)
1873 : {
1874 18 : rte->eref->colnames = lappend(rte->eref->colnames,
1875 18 : makeString(pstrdup("?column?")));
1876 : }
1877 :
1878 16232 : return parsetree;
1879 : }
1880 :
1881 : /*
1882 : * Recursively mark all relations used by a view as FOR [KEY] UPDATE/SHARE.
1883 : *
1884 : * This may generate an invalid query, eg if some sub-query uses an
1885 : * aggregate. We leave it to the planner to detect that.
1886 : *
1887 : * NB: this must agree with the parser's transformLockingClause() routine.
1888 : * However, we used to have to avoid marking a view's OLD and NEW rels for
1889 : * updating, which motivated scanning the jointree to determine which rels
1890 : * are used. Possibly that could now be simplified into just scanning the
1891 : * rangetable as the parser does.
1892 : */
1893 : static void
1894 192 : markQueryForLocking(Query *qry, Node *jtnode,
1895 : LockClauseStrength strength, LockWaitPolicy waitPolicy,
1896 : bool pushedDown)
1897 : {
1898 192 : if (jtnode == NULL)
1899 0 : return;
1900 192 : if (IsA(jtnode, RangeTblRef))
1901 : {
1902 96 : int rti = ((RangeTblRef *) jtnode)->rtindex;
1903 96 : RangeTblEntry *rte = rt_fetch(rti, qry->rtable);
1904 :
1905 96 : if (rte->rtekind == RTE_RELATION)
1906 : {
1907 : RTEPermissionInfo *perminfo;
1908 :
1909 96 : applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
1910 :
1911 96 : perminfo = getRTEPermissionInfo(qry->rteperminfos, rte);
1912 96 : perminfo->requiredPerms |= ACL_SELECT_FOR_UPDATE;
1913 : }
1914 0 : else if (rte->rtekind == RTE_SUBQUERY)
1915 : {
1916 0 : applyLockingClause(qry, rti, strength, waitPolicy, pushedDown);
1917 : /* FOR UPDATE/SHARE of subquery is propagated to subquery's rels */
1918 0 : markQueryForLocking(rte->subquery, (Node *) rte->subquery->jointree,
1919 : strength, waitPolicy, true);
1920 : }
1921 : /* other RTE types are unaffected by FOR UPDATE */
1922 : }
1923 96 : else if (IsA(jtnode, FromExpr))
1924 : {
1925 96 : FromExpr *f = (FromExpr *) jtnode;
1926 : ListCell *l;
1927 :
1928 192 : foreach(l, f->fromlist)
1929 96 : markQueryForLocking(qry, lfirst(l), strength, waitPolicy, pushedDown);
1930 : }
1931 0 : else if (IsA(jtnode, JoinExpr))
1932 : {
1933 0 : JoinExpr *j = (JoinExpr *) jtnode;
1934 :
1935 0 : markQueryForLocking(qry, j->larg, strength, waitPolicy, pushedDown);
1936 0 : markQueryForLocking(qry, j->rarg, strength, waitPolicy, pushedDown);
1937 : }
1938 : else
1939 0 : elog(ERROR, "unrecognized node type: %d",
1940 : (int) nodeTag(jtnode));
1941 : }
1942 :
1943 :
1944 : /*
1945 : * fireRIRonSubLink -
1946 : * Apply fireRIRrules() to each SubLink (subselect in expression) found
1947 : * in the given tree.
1948 : *
1949 : * NOTE: although this has the form of a walker, we cheat and modify the
1950 : * SubLink nodes in-place. It is caller's responsibility to ensure that
1951 : * no unwanted side-effects occur!
1952 : *
1953 : * This is unlike most of the other routines that recurse into subselects,
1954 : * because we must take control at the SubLink node in order to replace
1955 : * the SubLink's subselect link with the possibly-rewritten subquery.
1956 : */
1957 : static bool
1958 2712070 : fireRIRonSubLink(Node *node, fireRIRonSubLink_context *context)
1959 : {
1960 2712070 : if (node == NULL)
1961 543788 : return false;
1962 2168282 : if (IsA(node, SubLink))
1963 : {
1964 47248 : SubLink *sub = (SubLink *) node;
1965 :
1966 : /* Do what we came for */
1967 47248 : sub->subselect = (Node *) fireRIRrules((Query *) sub->subselect,
1968 : context->activeRIRs);
1969 :
1970 : /*
1971 : * Remember if any of the sublinks have row security.
1972 : */
1973 47176 : context->hasRowSecurity |= ((Query *) sub->subselect)->hasRowSecurity;
1974 :
1975 : /* Fall through to process lefthand args of SubLink */
1976 : }
1977 :
1978 : /*
1979 : * Do NOT recurse into Query nodes, because fireRIRrules already processed
1980 : * subselects of subselects for us.
1981 : */
1982 2168210 : return expression_tree_walker(node, fireRIRonSubLink, context);
1983 : }
1984 :
1985 :
1986 : /*
1987 : * fireRIRrules -
1988 : * Apply all RIR rules on each rangetable entry in the given query
1989 : *
1990 : * activeRIRs is a list of the OIDs of views we're already processing RIR
1991 : * rules for, used to detect/reject recursion.
1992 : */
1993 : static Query *
1994 563512 : fireRIRrules(Query *parsetree, List *activeRIRs)
1995 : {
1996 563512 : int origResultRelation = parsetree->resultRelation;
1997 : int rt_index;
1998 : ListCell *lc;
1999 :
2000 : /*
2001 : * Expand SEARCH and CYCLE clauses in CTEs.
2002 : *
2003 : * This is just a convenient place to do this, since we are already
2004 : * looking at each Query.
2005 : */
2006 567622 : foreach(lc, parsetree->cteList)
2007 : {
2008 4116 : CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc);
2009 :
2010 4116 : if (cte->search_clause || cte->cycle_clause)
2011 : {
2012 144 : cte = rewriteSearchAndCycle(cte);
2013 138 : lfirst(lc) = cte;
2014 : }
2015 : }
2016 :
2017 : /*
2018 : * don't try to convert this into a foreach loop, because rtable list can
2019 : * get changed each time through...
2020 : */
2021 563506 : rt_index = 0;
2022 1262526 : while (rt_index < list_length(parsetree->rtable))
2023 : {
2024 : RangeTblEntry *rte;
2025 : Relation rel;
2026 : List *locks;
2027 : RuleLock *rules;
2028 : RewriteRule *rule;
2029 : int i;
2030 :
2031 699056 : ++rt_index;
2032 :
2033 699056 : rte = rt_fetch(rt_index, parsetree->rtable);
2034 :
2035 : /*
2036 : * A subquery RTE can't have associated rules, so there's nothing to
2037 : * do to this level of the query, but we must recurse into the
2038 : * subquery to expand any rule references in it.
2039 : */
2040 699056 : if (rte->rtekind == RTE_SUBQUERY)
2041 : {
2042 52638 : rte->subquery = fireRIRrules(rte->subquery, activeRIRs);
2043 :
2044 : /*
2045 : * While we are here, make sure the query is marked as having row
2046 : * security if any of its subqueries do.
2047 : */
2048 52638 : parsetree->hasRowSecurity |= rte->subquery->hasRowSecurity;
2049 :
2050 52638 : continue;
2051 : }
2052 :
2053 : /*
2054 : * Joins and other non-relation RTEs can be ignored completely.
2055 : */
2056 646418 : if (rte->rtekind != RTE_RELATION)
2057 167174 : continue;
2058 :
2059 : /*
2060 : * Always ignore RIR rules for materialized views referenced in
2061 : * queries. (This does not prevent refreshing MVs, since they aren't
2062 : * referenced in their own query definitions.)
2063 : *
2064 : * Note: in the future we might want to allow MVs to be conditionally
2065 : * expanded as if they were regular views, if they are not scannable.
2066 : * In that case this test would need to be postponed till after we've
2067 : * opened the rel, so that we could check its state.
2068 : */
2069 479244 : if (rte->relkind == RELKIND_MATVIEW)
2070 458 : continue;
2071 :
2072 : /*
2073 : * In INSERT ... ON CONFLICT, ignore the EXCLUDED pseudo-relation;
2074 : * even if it points to a view, we needn't expand it, and should not
2075 : * because we want the RTE to remain of RTE_RELATION type. Otherwise,
2076 : * it would get changed to RTE_SUBQUERY type, which is an
2077 : * untested/unsupported situation.
2078 : */
2079 478786 : if (parsetree->onConflict &&
2080 3706 : rt_index == parsetree->onConflict->exclRelIndex)
2081 1338 : continue;
2082 :
2083 : /*
2084 : * If the table is not referenced in the query, then we ignore it.
2085 : * This prevents infinite expansion loop due to new rtable entries
2086 : * inserted by expansion of a rule. A table is referenced if it is
2087 : * part of the join set (a source table), or is referenced by any Var
2088 : * nodes, or is the result table.
2089 : */
2090 477448 : if (rt_index != parsetree->resultRelation &&
2091 390062 : !rangeTableEntry_used((Node *) parsetree, rt_index, 0))
2092 7238 : continue;
2093 :
2094 : /*
2095 : * Also, if this is a new result relation introduced by
2096 : * ApplyRetrieveRule, we don't want to do anything more with it.
2097 : */
2098 470210 : if (rt_index == parsetree->resultRelation &&
2099 : rt_index != origResultRelation)
2100 288 : continue;
2101 :
2102 : /*
2103 : * We can use NoLock here since either the parser or
2104 : * AcquireRewriteLocks should have locked the rel already.
2105 : */
2106 469922 : rel = table_open(rte->relid, NoLock);
2107 :
2108 : /*
2109 : * Collect the RIR rules that we must apply
2110 : */
2111 469922 : rules = rel->rd_rules;
2112 469922 : if (rules != NULL)
2113 : {
2114 17696 : locks = NIL;
2115 38384 : for (i = 0; i < rules->numLocks; i++)
2116 : {
2117 20688 : rule = rules->rules[i];
2118 20688 : if (rule->event != CMD_SELECT)
2119 4300 : continue;
2120 :
2121 16388 : locks = lappend(locks, rule);
2122 : }
2123 :
2124 : /*
2125 : * If we found any, apply them --- but first check for recursion!
2126 : */
2127 17696 : if (locks != NIL)
2128 : {
2129 : ListCell *l;
2130 :
2131 16388 : if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
2132 0 : ereport(ERROR,
2133 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2134 : errmsg("infinite recursion detected in rules for relation \"%s\"",
2135 : RelationGetRelationName(rel))));
2136 16388 : activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
2137 :
2138 32740 : foreach(l, locks)
2139 : {
2140 16388 : rule = lfirst(l);
2141 :
2142 16388 : parsetree = ApplyRetrieveRule(parsetree,
2143 : rule,
2144 : rt_index,
2145 : rel,
2146 : activeRIRs);
2147 : }
2148 :
2149 16352 : activeRIRs = list_delete_last(activeRIRs);
2150 : }
2151 : }
2152 :
2153 469886 : table_close(rel, NoLock);
2154 : }
2155 :
2156 : /* Recurse into subqueries in WITH */
2157 567580 : foreach(lc, parsetree->cteList)
2158 : {
2159 4110 : CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
2160 :
2161 4110 : cte->ctequery = (Node *)
2162 4110 : fireRIRrules((Query *) cte->ctequery, activeRIRs);
2163 :
2164 : /*
2165 : * While we are here, make sure the query is marked as having row
2166 : * security if any of its CTEs do.
2167 : */
2168 4110 : parsetree->hasRowSecurity |= ((Query *) cte->ctequery)->hasRowSecurity;
2169 : }
2170 :
2171 : /*
2172 : * Recurse into sublink subqueries, too. But we already did the ones in
2173 : * the rtable and cteList.
2174 : */
2175 563470 : if (parsetree->hasSubLinks)
2176 : {
2177 : fireRIRonSubLink_context context;
2178 :
2179 37640 : context.activeRIRs = activeRIRs;
2180 37640 : context.hasRowSecurity = false;
2181 :
2182 37640 : query_tree_walker(parsetree, fireRIRonSubLink, &context,
2183 : QTW_IGNORE_RC_SUBQUERIES);
2184 :
2185 : /*
2186 : * Make sure the query is marked as having row security if any of its
2187 : * sublinks do.
2188 : */
2189 37640 : parsetree->hasRowSecurity |= context.hasRowSecurity;
2190 : }
2191 :
2192 : /*
2193 : * Apply any row-level security policies. We do this last because it
2194 : * requires special recursion detection if the new quals have sublink
2195 : * subqueries, and if we did it in the loop above query_tree_walker would
2196 : * then recurse into those quals a second time.
2197 : */
2198 563470 : rt_index = 0;
2199 1262316 : foreach(lc, parsetree->rtable)
2200 : {
2201 699020 : RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
2202 : Relation rel;
2203 : List *securityQuals;
2204 : List *withCheckOptions;
2205 : bool hasRowSecurity;
2206 : bool hasSubLinks;
2207 :
2208 699020 : ++rt_index;
2209 :
2210 : /* Only normal relations can have RLS policies */
2211 699020 : if (rte->rtekind != RTE_RELATION ||
2212 462976 : (rte->relkind != RELKIND_RELATION &&
2213 24710 : rte->relkind != RELKIND_PARTITIONED_TABLE))
2214 244864 : continue;
2215 :
2216 454156 : rel = table_open(rte->relid, NoLock);
2217 :
2218 : /*
2219 : * Fetch any new security quals that must be applied to this RTE.
2220 : */
2221 454156 : get_row_security_policies(parsetree, rte, rt_index,
2222 : &securityQuals, &withCheckOptions,
2223 : &hasRowSecurity, &hasSubLinks);
2224 :
2225 454096 : if (securityQuals != NIL || withCheckOptions != NIL)
2226 : {
2227 3084 : if (hasSubLinks)
2228 : {
2229 : acquireLocksOnSubLinks_context context;
2230 : fireRIRonSubLink_context fire_context;
2231 :
2232 : /*
2233 : * Recursively process the new quals, checking for infinite
2234 : * recursion.
2235 : */
2236 702 : if (list_member_oid(activeRIRs, RelationGetRelid(rel)))
2237 42 : ereport(ERROR,
2238 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
2239 : errmsg("infinite recursion detected in policy for relation \"%s\"",
2240 : RelationGetRelationName(rel))));
2241 :
2242 660 : activeRIRs = lappend_oid(activeRIRs, RelationGetRelid(rel));
2243 :
2244 : /*
2245 : * get_row_security_policies just passed back securityQuals
2246 : * and/or withCheckOptions, and there were SubLinks, make sure
2247 : * we lock any relations which are referenced.
2248 : *
2249 : * These locks would normally be acquired by the parser, but
2250 : * securityQuals and withCheckOptions are added post-parsing.
2251 : */
2252 660 : context.for_execute = true;
2253 660 : (void) acquireLocksOnSubLinks((Node *) securityQuals, &context);
2254 660 : (void) acquireLocksOnSubLinks((Node *) withCheckOptions,
2255 : &context);
2256 :
2257 : /*
2258 : * Now that we have the locks on anything added by
2259 : * get_row_security_policies, fire any RIR rules for them.
2260 : */
2261 660 : fire_context.activeRIRs = activeRIRs;
2262 660 : fire_context.hasRowSecurity = false;
2263 :
2264 660 : expression_tree_walker((Node *) securityQuals,
2265 : fireRIRonSubLink, &fire_context);
2266 :
2267 594 : expression_tree_walker((Node *) withCheckOptions,
2268 : fireRIRonSubLink, &fire_context);
2269 :
2270 : /*
2271 : * We can ignore the value of fire_context.hasRowSecurity
2272 : * since we only reach this code in cases where hasRowSecurity
2273 : * is already true.
2274 : */
2275 : Assert(hasRowSecurity);
2276 :
2277 588 : activeRIRs = list_delete_last(activeRIRs);
2278 : }
2279 :
2280 : /*
2281 : * Add the new security barrier quals to the start of the RTE's
2282 : * list so that they get applied before any existing barrier quals
2283 : * (which would have come from a security-barrier view, and should
2284 : * get lower priority than RLS conditions on the table itself).
2285 : */
2286 5940 : rte->securityQuals = list_concat(securityQuals,
2287 2970 : rte->securityQuals);
2288 :
2289 2970 : parsetree->withCheckOptions = list_concat(withCheckOptions,
2290 2970 : parsetree->withCheckOptions);
2291 : }
2292 :
2293 : /*
2294 : * Make sure the query is marked correctly if row-level security
2295 : * applies, or if the new quals had sublinks.
2296 : */
2297 453982 : if (hasRowSecurity)
2298 3582 : parsetree->hasRowSecurity = true;
2299 453982 : if (hasSubLinks)
2300 588 : parsetree->hasSubLinks = true;
2301 :
2302 453982 : table_close(rel, NoLock);
2303 : }
2304 :
2305 563296 : return parsetree;
2306 : }
2307 :
2308 :
2309 : /*
2310 : * Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its
2311 : * qualification. This is used to generate suitable "else clauses" for
2312 : * conditional INSTEAD rules. (Unfortunately we must use "x IS NOT TRUE",
2313 : * not just "NOT x" which the planner is much smarter about, else we will
2314 : * do the wrong thing when the qual evaluates to NULL.)
2315 : *
2316 : * The rule_qual may contain references to OLD or NEW. OLD references are
2317 : * replaced by references to the specified rt_index (the relation that the
2318 : * rule applies to). NEW references are only possible for INSERT and UPDATE
2319 : * queries on the relation itself, and so they should be replaced by copies
2320 : * of the related entries in the query's own targetlist.
2321 : */
2322 : static Query *
2323 444 : CopyAndAddInvertedQual(Query *parsetree,
2324 : Node *rule_qual,
2325 : int rt_index,
2326 : CmdType event)
2327 : {
2328 : /* Don't scribble on the passed qual (it's in the relcache!) */
2329 444 : Node *new_qual = copyObject(rule_qual);
2330 : acquireLocksOnSubLinks_context context;
2331 :
2332 444 : context.for_execute = true;
2333 :
2334 : /*
2335 : * In case there are subqueries in the qual, acquire necessary locks and
2336 : * fix any deleted JOIN RTE entries. (This is somewhat redundant with
2337 : * rewriteRuleAction, but not entirely ... consider restructuring so that
2338 : * we only need to process the qual this way once.)
2339 : */
2340 444 : (void) acquireLocksOnSubLinks(new_qual, &context);
2341 :
2342 : /* Fix references to OLD */
2343 444 : ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
2344 : /* Fix references to NEW */
2345 444 : if (event == CMD_INSERT || event == CMD_UPDATE)
2346 864 : new_qual = ReplaceVarsFromTargetList(new_qual,
2347 : PRS2_NEW_VARNO,
2348 : 0,
2349 432 : rt_fetch(rt_index,
2350 : parsetree->rtable),
2351 : parsetree->targetList,
2352 : parsetree->resultRelation,
2353 : (event == CMD_UPDATE) ?
2354 : REPLACEVARS_CHANGE_VARNO :
2355 : REPLACEVARS_SUBSTITUTE_NULL,
2356 : rt_index,
2357 : &parsetree->hasSubLinks);
2358 : /* And attach the fixed qual */
2359 444 : AddInvertedQual(parsetree, new_qual);
2360 :
2361 444 : return parsetree;
2362 : }
2363 :
2364 :
2365 : /*
2366 : * fireRules -
2367 : * Iterate through rule locks applying rules.
2368 : *
2369 : * Input arguments:
2370 : * parsetree - original query
2371 : * rt_index - RT index of result relation in original query
2372 : * event - type of rule event
2373 : * locks - list of rules to fire
2374 : * Output arguments:
2375 : * *instead_flag - set true if any unqualified INSTEAD rule is found
2376 : * (must be initialized to false)
2377 : * *returning_flag - set true if we rewrite RETURNING clause in any rule
2378 : * (must be initialized to false)
2379 : * *qual_product - filled with modified original query if any qualified
2380 : * INSTEAD rule is found (must be initialized to NULL)
2381 : * Return value:
2382 : * list of rule actions adjusted for use with this query
2383 : *
2384 : * Qualified INSTEAD rules generate their action with the qualification
2385 : * condition added. They also generate a modified version of the original
2386 : * query with the negated qualification added, so that it will run only for
2387 : * rows that the qualified action doesn't act on. (If there are multiple
2388 : * qualified INSTEAD rules, we AND all the negated quals onto a single
2389 : * modified original query.) We won't execute the original, unmodified
2390 : * query if we find either qualified or unqualified INSTEAD rules. If
2391 : * we find both, the modified original query is discarded too.
2392 : */
2393 : static List *
2394 91480 : fireRules(Query *parsetree,
2395 : int rt_index,
2396 : CmdType event,
2397 : List *locks,
2398 : bool *instead_flag,
2399 : bool *returning_flag,
2400 : Query **qual_product)
2401 : {
2402 91480 : List *results = NIL;
2403 : ListCell *l;
2404 :
2405 93016 : foreach(l, locks)
2406 : {
2407 1542 : RewriteRule *rule_lock = (RewriteRule *) lfirst(l);
2408 1542 : Node *event_qual = rule_lock->qual;
2409 1542 : List *actions = rule_lock->actions;
2410 : QuerySource qsrc;
2411 : ListCell *r;
2412 :
2413 : /* Determine correct QuerySource value for actions */
2414 1542 : if (rule_lock->isInstead)
2415 : {
2416 1158 : if (event_qual != NULL)
2417 450 : qsrc = QSRC_QUAL_INSTEAD_RULE;
2418 : else
2419 : {
2420 708 : qsrc = QSRC_INSTEAD_RULE;
2421 708 : *instead_flag = true; /* report unqualified INSTEAD */
2422 : }
2423 : }
2424 : else
2425 384 : qsrc = QSRC_NON_INSTEAD_RULE;
2426 :
2427 1542 : if (qsrc == QSRC_QUAL_INSTEAD_RULE)
2428 : {
2429 : /*
2430 : * If there are INSTEAD rules with qualifications, the original
2431 : * query is still performed. But all the negated rule
2432 : * qualifications of the INSTEAD rules are added so it does its
2433 : * actions only in cases where the rule quals of all INSTEAD rules
2434 : * are false. Think of it as the default action in a case. We save
2435 : * this in *qual_product so RewriteQuery() can add it to the query
2436 : * list after we mangled it up enough.
2437 : *
2438 : * If we have already found an unqualified INSTEAD rule, then
2439 : * *qual_product won't be used, so don't bother building it.
2440 : */
2441 450 : if (!*instead_flag)
2442 : {
2443 444 : if (*qual_product == NULL)
2444 360 : *qual_product = copyObject(parsetree);
2445 444 : *qual_product = CopyAndAddInvertedQual(*qual_product,
2446 : event_qual,
2447 : rt_index,
2448 : event);
2449 : }
2450 : }
2451 :
2452 : /* Now process the rule's actions and add them to the result list */
2453 3132 : foreach(r, actions)
2454 : {
2455 1596 : Query *rule_action = lfirst(r);
2456 :
2457 1596 : if (rule_action->commandType == CMD_NOTHING)
2458 210 : continue;
2459 :
2460 1386 : rule_action = rewriteRuleAction(parsetree, rule_action,
2461 : event_qual, rt_index, event,
2462 : returning_flag);
2463 :
2464 1380 : rule_action->querySource = qsrc;
2465 1380 : rule_action->canSetTag = false; /* might change later */
2466 :
2467 1380 : results = lappend(results, rule_action);
2468 : }
2469 : }
2470 :
2471 91474 : return results;
2472 : }
2473 :
2474 :
2475 : /*
2476 : * get_view_query - get the Query from a view's _RETURN rule.
2477 : *
2478 : * Caller should have verified that the relation is a view, and therefore
2479 : * we should find an ON SELECT action.
2480 : *
2481 : * Note that the pointer returned is into the relcache and therefore must
2482 : * be treated as read-only to the caller and not modified or scribbled on.
2483 : */
2484 : Query *
2485 5902 : get_view_query(Relation view)
2486 : {
2487 : int i;
2488 :
2489 : Assert(view->rd_rel->relkind == RELKIND_VIEW);
2490 :
2491 5902 : for (i = 0; i < view->rd_rules->numLocks; i++)
2492 : {
2493 5902 : RewriteRule *rule = view->rd_rules->rules[i];
2494 :
2495 5902 : if (rule->event == CMD_SELECT)
2496 : {
2497 : /* A _RETURN rule should have only one action */
2498 5902 : if (list_length(rule->actions) != 1)
2499 0 : elog(ERROR, "invalid _RETURN rule action specification");
2500 :
2501 5902 : return (Query *) linitial(rule->actions);
2502 : }
2503 : }
2504 :
2505 0 : elog(ERROR, "failed to find _RETURN rule for view");
2506 : return NULL; /* keep compiler quiet */
2507 : }
2508 :
2509 :
2510 : /*
2511 : * view_has_instead_trigger - does view have an INSTEAD OF trigger for event?
2512 : *
2513 : * If it does, we don't want to treat it as auto-updatable. This test can't
2514 : * be folded into view_query_is_auto_updatable because it's not an error
2515 : * condition.
2516 : *
2517 : * For MERGE, this will return true if there is an INSTEAD OF trigger for
2518 : * every action in mergeActionList, and false if there are any actions that
2519 : * lack an INSTEAD OF trigger. If there are no data-modifying MERGE actions
2520 : * (only DO NOTHING actions), true is returned so that the view is treated
2521 : * as trigger-updatable, rather than erroring out if it's not auto-updatable.
2522 : */
2523 : bool
2524 5504 : view_has_instead_trigger(Relation view, CmdType event, List *mergeActionList)
2525 : {
2526 5504 : TriggerDesc *trigDesc = view->trigdesc;
2527 :
2528 5504 : switch (event)
2529 : {
2530 1782 : case CMD_INSERT:
2531 1782 : if (trigDesc && trigDesc->trig_insert_instead_row)
2532 264 : return true;
2533 1518 : break;
2534 2060 : case CMD_UPDATE:
2535 2060 : if (trigDesc && trigDesc->trig_update_instead_row)
2536 318 : return true;
2537 1742 : break;
2538 612 : case CMD_DELETE:
2539 612 : if (trigDesc && trigDesc->trig_delete_instead_row)
2540 108 : return true;
2541 504 : break;
2542 1050 : case CMD_MERGE:
2543 1482 : foreach_node(MergeAction, action, mergeActionList)
2544 : {
2545 1170 : switch (action->commandType)
2546 : {
2547 204 : case CMD_INSERT:
2548 204 : if (!trigDesc || !trigDesc->trig_insert_instead_row)
2549 894 : return false;
2550 84 : break;
2551 744 : case CMD_UPDATE:
2552 744 : if (!trigDesc || !trigDesc->trig_update_instead_row)
2553 636 : return false;
2554 108 : break;
2555 162 : case CMD_DELETE:
2556 162 : if (!trigDesc || !trigDesc->trig_delete_instead_row)
2557 138 : return false;
2558 24 : break;
2559 60 : case CMD_NOTHING:
2560 : /* No trigger required */
2561 60 : break;
2562 0 : default:
2563 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
2564 : break;
2565 : }
2566 : }
2567 156 : return true; /* no actions without an INSTEAD OF trigger */
2568 0 : default:
2569 0 : elog(ERROR, "unrecognized CmdType: %d", (int) event);
2570 : break;
2571 : }
2572 3764 : return false;
2573 : }
2574 :
2575 :
2576 : /*
2577 : * view_col_is_auto_updatable - test whether the specified column of a view
2578 : * is auto-updatable. Returns NULL (if the column can be updated) or a message
2579 : * string giving the reason that it cannot be.
2580 : *
2581 : * The returned string has not been translated; if it is shown as an error
2582 : * message, the caller should apply _() to translate it.
2583 : *
2584 : * Note that the checks performed here are local to this view. We do not check
2585 : * whether the referenced column of the underlying base relation is updatable.
2586 : */
2587 : static const char *
2588 14412 : view_col_is_auto_updatable(RangeTblRef *rtr, TargetEntry *tle)
2589 : {
2590 14412 : Var *var = (Var *) tle->expr;
2591 :
2592 : /*
2593 : * For now, the only updatable columns we support are those that are Vars
2594 : * referring to user columns of the underlying base relation.
2595 : *
2596 : * The view targetlist may contain resjunk columns (e.g., a view defined
2597 : * like "SELECT * FROM t ORDER BY a+b" is auto-updatable) but such columns
2598 : * are not auto-updatable, and in fact should never appear in the outer
2599 : * query's targetlist.
2600 : */
2601 14412 : if (tle->resjunk)
2602 180 : return gettext_noop("Junk view columns are not updatable.");
2603 :
2604 14232 : if (!IsA(var, Var) ||
2605 12810 : var->varno != rtr->rtindex ||
2606 12810 : var->varlevelsup != 0)
2607 1422 : return gettext_noop("View columns that are not columns of their base relation are not updatable.");
2608 :
2609 12810 : if (var->varattno < 0)
2610 402 : return gettext_noop("View columns that refer to system columns are not updatable.");
2611 :
2612 12408 : if (var->varattno == 0)
2613 0 : return gettext_noop("View columns that return whole-row references are not updatable.");
2614 :
2615 12408 : return NULL; /* the view column is updatable */
2616 : }
2617 :
2618 :
2619 : /*
2620 : * view_query_is_auto_updatable - test whether the specified view definition
2621 : * represents an auto-updatable view. Returns NULL (if the view can be updated)
2622 : * or a message string giving the reason that it cannot be.
2623 :
2624 : * The returned string has not been translated; if it is shown as an error
2625 : * message, the caller should apply _() to translate it.
2626 : *
2627 : * If check_cols is true, the view is required to have at least one updatable
2628 : * column (necessary for INSERT/UPDATE). Otherwise the view's columns are not
2629 : * checked for updatability. See also view_cols_are_auto_updatable.
2630 : *
2631 : * Note that the checks performed here are only based on the view definition.
2632 : * We do not check whether any base relations referred to by the view are
2633 : * updatable.
2634 : */
2635 : const char *
2636 5680 : view_query_is_auto_updatable(Query *viewquery, bool check_cols)
2637 : {
2638 : RangeTblRef *rtr;
2639 : RangeTblEntry *base_rte;
2640 :
2641 : /*----------
2642 : * Check if the view is simply updatable. According to SQL-92 this means:
2643 : * - No DISTINCT clause.
2644 : * - Each TLE is a column reference, and each column appears at most once.
2645 : * - FROM contains exactly one base relation.
2646 : * - No GROUP BY or HAVING clauses.
2647 : * - No set operations (UNION, INTERSECT or EXCEPT).
2648 : * - No sub-queries in the WHERE clause that reference the target table.
2649 : *
2650 : * We ignore that last restriction since it would be complex to enforce
2651 : * and there isn't any actual benefit to disallowing sub-queries. (The
2652 : * semantic issues that the standard is presumably concerned about don't
2653 : * arise in Postgres, since any such sub-query will not see any updates
2654 : * executed by the outer query anyway, thanks to MVCC snapshotting.)
2655 : *
2656 : * We also relax the second restriction by supporting part of SQL:1999
2657 : * feature T111, which allows for a mix of updatable and non-updatable
2658 : * columns, provided that an INSERT or UPDATE doesn't attempt to assign to
2659 : * a non-updatable column.
2660 : *
2661 : * In addition we impose these constraints, involving features that are
2662 : * not part of SQL-92:
2663 : * - No CTEs (WITH clauses).
2664 : * - No OFFSET or LIMIT clauses (this matches a SQL:2008 restriction).
2665 : * - No system columns (including whole-row references) in the tlist.
2666 : * - No window functions in the tlist.
2667 : * - No set-returning functions in the tlist.
2668 : *
2669 : * Note that we do these checks without recursively expanding the view.
2670 : * If the base relation is a view, we'll recursively deal with it later.
2671 : *----------
2672 : */
2673 5680 : if (viewquery->distinctClause != NIL)
2674 72 : return gettext_noop("Views containing DISTINCT are not automatically updatable.");
2675 :
2676 5608 : if (viewquery->groupClause != NIL || viewquery->groupingSets)
2677 36 : return gettext_noop("Views containing GROUP BY are not automatically updatable.");
2678 :
2679 5572 : if (viewquery->havingQual != NULL)
2680 30 : return gettext_noop("Views containing HAVING are not automatically updatable.");
2681 :
2682 5542 : if (viewquery->setOperations != NULL)
2683 36 : return gettext_noop("Views containing UNION, INTERSECT, or EXCEPT are not automatically updatable.");
2684 :
2685 5506 : if (viewquery->cteList != NIL)
2686 36 : return gettext_noop("Views containing WITH are not automatically updatable.");
2687 :
2688 5470 : if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL)
2689 576 : return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
2690 :
2691 : /*
2692 : * We must not allow window functions or set returning functions in the
2693 : * targetlist. Otherwise we might end up inserting them into the quals of
2694 : * the main query. We must also check for aggregates in the targetlist in
2695 : * case they appear without a GROUP BY.
2696 : *
2697 : * These restrictions ensure that each row of the view corresponds to a
2698 : * unique row in the underlying base relation.
2699 : */
2700 4894 : if (viewquery->hasAggs)
2701 30 : return gettext_noop("Views that return aggregate functions are not automatically updatable.");
2702 :
2703 4864 : if (viewquery->hasWindowFuncs)
2704 36 : return gettext_noop("Views that return window functions are not automatically updatable.");
2705 :
2706 4828 : if (viewquery->hasTargetSRFs)
2707 42 : return gettext_noop("Views that return set-returning functions are not automatically updatable.");
2708 :
2709 : /*
2710 : * The view query should select from a single base relation, which must be
2711 : * a table or another view.
2712 : */
2713 4786 : if (list_length(viewquery->jointree->fromlist) != 1)
2714 66 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2715 :
2716 4720 : rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
2717 4720 : if (!IsA(rtr, RangeTblRef))
2718 0 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2719 :
2720 4720 : base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
2721 4720 : if (base_rte->rtekind != RTE_RELATION ||
2722 4606 : (base_rte->relkind != RELKIND_RELATION &&
2723 1802 : base_rte->relkind != RELKIND_FOREIGN_TABLE &&
2724 1780 : base_rte->relkind != RELKIND_VIEW &&
2725 256 : base_rte->relkind != RELKIND_PARTITIONED_TABLE))
2726 156 : return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
2727 :
2728 4564 : if (base_rte->tablesample)
2729 6 : return gettext_noop("Views containing TABLESAMPLE are not automatically updatable.");
2730 :
2731 : /*
2732 : * Check that the view has at least one updatable column. This is required
2733 : * for INSERT/UPDATE but not for DELETE.
2734 : */
2735 4558 : if (check_cols)
2736 : {
2737 : ListCell *cell;
2738 : bool found;
2739 :
2740 3124 : found = false;
2741 3310 : foreach(cell, viewquery->targetList)
2742 : {
2743 3310 : TargetEntry *tle = (TargetEntry *) lfirst(cell);
2744 :
2745 3310 : if (view_col_is_auto_updatable(rtr, tle) == NULL)
2746 : {
2747 3124 : found = true;
2748 3124 : break;
2749 : }
2750 : }
2751 :
2752 3124 : if (!found)
2753 0 : return gettext_noop("Views that have no updatable columns are not automatically updatable.");
2754 : }
2755 :
2756 4558 : return NULL; /* the view is updatable */
2757 : }
2758 :
2759 :
2760 : /*
2761 : * view_cols_are_auto_updatable - test whether all of the required columns of
2762 : * an auto-updatable view are actually updatable. Returns NULL (if all the
2763 : * required columns can be updated) or a message string giving the reason that
2764 : * they cannot be.
2765 : *
2766 : * The returned string has not been translated; if it is shown as an error
2767 : * message, the caller should apply _() to translate it.
2768 : *
2769 : * This should be used for INSERT/UPDATE to ensure that we don't attempt to
2770 : * assign to any non-updatable columns.
2771 : *
2772 : * Additionally it may be used to retrieve the set of updatable columns in the
2773 : * view, or if one or more of the required columns is not updatable, the name
2774 : * of the first offending non-updatable column.
2775 : *
2776 : * The caller must have already verified that this is an auto-updatable view
2777 : * using view_query_is_auto_updatable.
2778 : *
2779 : * Note that the checks performed here are only based on the view definition.
2780 : * We do not check whether the referenced columns of the base relation are
2781 : * updatable.
2782 : */
2783 : static const char *
2784 4022 : view_cols_are_auto_updatable(Query *viewquery,
2785 : Bitmapset *required_cols,
2786 : Bitmapset **updatable_cols,
2787 : char **non_updatable_col)
2788 : {
2789 : RangeTblRef *rtr;
2790 : AttrNumber col;
2791 : ListCell *cell;
2792 :
2793 : /*
2794 : * The caller should have verified that this view is auto-updatable and so
2795 : * there should be a single base relation.
2796 : */
2797 : Assert(list_length(viewquery->jointree->fromlist) == 1);
2798 4022 : rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
2799 :
2800 : /* Initialize the optional return values */
2801 4022 : if (updatable_cols != NULL)
2802 1050 : *updatable_cols = NULL;
2803 4022 : if (non_updatable_col != NULL)
2804 2972 : *non_updatable_col = NULL;
2805 :
2806 : /* Test each view column for updatability */
2807 4022 : col = -FirstLowInvalidHeapAttributeNumber;
2808 15004 : foreach(cell, viewquery->targetList)
2809 : {
2810 11102 : TargetEntry *tle = (TargetEntry *) lfirst(cell);
2811 : const char *col_update_detail;
2812 :
2813 11102 : col++;
2814 11102 : col_update_detail = view_col_is_auto_updatable(rtr, tle);
2815 :
2816 11102 : if (col_update_detail == NULL)
2817 : {
2818 : /* The column is updatable */
2819 9284 : if (updatable_cols != NULL)
2820 2136 : *updatable_cols = bms_add_member(*updatable_cols, col);
2821 : }
2822 1818 : else if (bms_is_member(col, required_cols))
2823 : {
2824 : /* The required column is not updatable */
2825 120 : if (non_updatable_col != NULL)
2826 120 : *non_updatable_col = tle->resname;
2827 120 : return col_update_detail;
2828 : }
2829 : }
2830 :
2831 3902 : return NULL; /* all the required view columns are updatable */
2832 : }
2833 :
2834 :
2835 : /*
2836 : * relation_is_updatable - determine which update events the specified
2837 : * relation supports.
2838 : *
2839 : * Note that views may contain a mix of updatable and non-updatable columns.
2840 : * For a view to support INSERT/UPDATE it must have at least one updatable
2841 : * column, but there is no such restriction for DELETE. If include_cols is
2842 : * non-NULL, then only the specified columns are considered when testing for
2843 : * updatability.
2844 : *
2845 : * Unlike the preceding functions, this does recurse to look at a view's
2846 : * base relations, so it needs to detect recursion. To do that, we pass
2847 : * a list of currently-considered outer relations. External callers need
2848 : * only pass NIL.
2849 : *
2850 : * This is used for the information_schema views, which have separate concepts
2851 : * of "updatable" and "trigger updatable". A relation is "updatable" if it
2852 : * can be updated without the need for triggers (either because it has a
2853 : * suitable RULE, or because it is simple enough to be automatically updated).
2854 : * A relation is "trigger updatable" if it has a suitable INSTEAD OF trigger.
2855 : * The SQL standard regards this as not necessarily updatable, presumably
2856 : * because there is no way of knowing what the trigger will actually do.
2857 : * The information_schema views therefore call this function with
2858 : * include_triggers = false. However, other callers might only care whether
2859 : * data-modifying SQL will work, so they can pass include_triggers = true
2860 : * to have trigger updatability included in the result.
2861 : *
2862 : * The return value is a bitmask of rule event numbers indicating which of
2863 : * the INSERT, UPDATE and DELETE operations are supported. (We do it this way
2864 : * so that we can test for UPDATE plus DELETE support in a single call.)
2865 : */
2866 : int
2867 2112 : relation_is_updatable(Oid reloid,
2868 : List *outer_reloids,
2869 : bool include_triggers,
2870 : Bitmapset *include_cols)
2871 : {
2872 2112 : int events = 0;
2873 : Relation rel;
2874 : RuleLock *rulelocks;
2875 :
2876 : #define ALL_EVENTS ((1 << CMD_INSERT) | (1 << CMD_UPDATE) | (1 << CMD_DELETE))
2877 :
2878 : /* Since this function recurses, it could be driven to stack overflow */
2879 2112 : check_stack_depth();
2880 :
2881 2112 : rel = try_relation_open(reloid, AccessShareLock);
2882 :
2883 : /*
2884 : * If the relation doesn't exist, return zero rather than throwing an
2885 : * error. This is helpful since scanning an information_schema view under
2886 : * MVCC rules can result in referencing rels that have actually been
2887 : * deleted already.
2888 : */
2889 2112 : if (rel == NULL)
2890 0 : return 0;
2891 :
2892 : /* If we detect a recursive view, report that it is not updatable */
2893 2112 : if (list_member_oid(outer_reloids, RelationGetRelid(rel)))
2894 : {
2895 0 : relation_close(rel, AccessShareLock);
2896 0 : return 0;
2897 : }
2898 :
2899 : /* If the relation is a table, it is always updatable */
2900 2112 : if (rel->rd_rel->relkind == RELKIND_RELATION ||
2901 2112 : rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
2902 : {
2903 18 : relation_close(rel, AccessShareLock);
2904 18 : return ALL_EVENTS;
2905 : }
2906 :
2907 : /* Look for unconditional DO INSTEAD rules, and note supported events */
2908 2094 : rulelocks = rel->rd_rules;
2909 2094 : if (rulelocks != NULL)
2910 : {
2911 : int i;
2912 :
2913 4560 : for (i = 0; i < rulelocks->numLocks; i++)
2914 : {
2915 2466 : if (rulelocks->rules[i]->isInstead &&
2916 2454 : rulelocks->rules[i]->qual == NULL)
2917 : {
2918 2454 : events |= ((1 << rulelocks->rules[i]->event) & ALL_EVENTS);
2919 : }
2920 : }
2921 :
2922 : /* If we have rules for all events, we're done */
2923 2094 : if (events == ALL_EVENTS)
2924 : {
2925 60 : relation_close(rel, AccessShareLock);
2926 60 : return events;
2927 : }
2928 : }
2929 :
2930 : /* Similarly look for INSTEAD OF triggers, if they are to be included */
2931 2034 : if (include_triggers)
2932 : {
2933 0 : TriggerDesc *trigDesc = rel->trigdesc;
2934 :
2935 0 : if (trigDesc)
2936 : {
2937 0 : if (trigDesc->trig_insert_instead_row)
2938 0 : events |= (1 << CMD_INSERT);
2939 0 : if (trigDesc->trig_update_instead_row)
2940 0 : events |= (1 << CMD_UPDATE);
2941 0 : if (trigDesc->trig_delete_instead_row)
2942 0 : events |= (1 << CMD_DELETE);
2943 :
2944 : /* If we have triggers for all events, we're done */
2945 0 : if (events == ALL_EVENTS)
2946 : {
2947 0 : relation_close(rel, AccessShareLock);
2948 0 : return events;
2949 : }
2950 : }
2951 : }
2952 :
2953 : /* If this is a foreign table, check which update events it supports */
2954 2034 : if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
2955 : {
2956 0 : FdwRoutine *fdwroutine = GetFdwRoutineForRelation(rel, false);
2957 :
2958 0 : if (fdwroutine->IsForeignRelUpdatable != NULL)
2959 0 : events |= fdwroutine->IsForeignRelUpdatable(rel);
2960 : else
2961 : {
2962 : /* Assume presence of executor functions is sufficient */
2963 0 : if (fdwroutine->ExecForeignInsert != NULL)
2964 0 : events |= (1 << CMD_INSERT);
2965 0 : if (fdwroutine->ExecForeignUpdate != NULL)
2966 0 : events |= (1 << CMD_UPDATE);
2967 0 : if (fdwroutine->ExecForeignDelete != NULL)
2968 0 : events |= (1 << CMD_DELETE);
2969 : }
2970 :
2971 0 : relation_close(rel, AccessShareLock);
2972 0 : return events;
2973 : }
2974 :
2975 : /* Check if this is an automatically updatable view */
2976 2034 : if (rel->rd_rel->relkind == RELKIND_VIEW)
2977 : {
2978 2034 : Query *viewquery = get_view_query(rel);
2979 :
2980 2034 : if (view_query_is_auto_updatable(viewquery, false) == NULL)
2981 : {
2982 : Bitmapset *updatable_cols;
2983 : int auto_events;
2984 : RangeTblRef *rtr;
2985 : RangeTblEntry *base_rte;
2986 : Oid baseoid;
2987 :
2988 : /*
2989 : * Determine which of the view's columns are updatable. If there
2990 : * are none within the set of columns we are looking at, then the
2991 : * view doesn't support INSERT/UPDATE, but it may still support
2992 : * DELETE.
2993 : */
2994 1050 : view_cols_are_auto_updatable(viewquery, NULL,
2995 : &updatable_cols, NULL);
2996 :
2997 1050 : if (include_cols != NULL)
2998 576 : updatable_cols = bms_int_members(updatable_cols, include_cols);
2999 :
3000 1050 : if (bms_is_empty(updatable_cols))
3001 150 : auto_events = (1 << CMD_DELETE); /* May support DELETE */
3002 : else
3003 900 : auto_events = ALL_EVENTS; /* May support all events */
3004 :
3005 : /*
3006 : * The base relation must also support these update commands.
3007 : * Tables are always updatable, but for any other kind of base
3008 : * relation we must do a recursive check limited to the columns
3009 : * referenced by the locally updatable columns in this view.
3010 : */
3011 1050 : rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
3012 1050 : base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
3013 : Assert(base_rte->rtekind == RTE_RELATION);
3014 :
3015 1050 : if (base_rte->relkind != RELKIND_RELATION &&
3016 582 : base_rte->relkind != RELKIND_PARTITIONED_TABLE)
3017 : {
3018 552 : baseoid = base_rte->relid;
3019 552 : outer_reloids = lappend_oid(outer_reloids,
3020 : RelationGetRelid(rel));
3021 552 : include_cols = adjust_view_column_set(updatable_cols,
3022 : viewquery->targetList);
3023 552 : auto_events &= relation_is_updatable(baseoid,
3024 : outer_reloids,
3025 : include_triggers,
3026 : include_cols);
3027 552 : outer_reloids = list_delete_last(outer_reloids);
3028 : }
3029 1050 : events |= auto_events;
3030 : }
3031 : }
3032 :
3033 : /* If we reach here, the relation may support some update commands */
3034 2034 : relation_close(rel, AccessShareLock);
3035 2034 : return events;
3036 : }
3037 :
3038 :
3039 : /*
3040 : * adjust_view_column_set - map a set of column numbers according to targetlist
3041 : *
3042 : * This is used with simply-updatable views to map column-permissions sets for
3043 : * the view columns onto the matching columns in the underlying base relation.
3044 : * Relevant entries in the targetlist must be plain Vars of the underlying
3045 : * relation (as per the checks above in view_query_is_auto_updatable).
3046 : */
3047 : static Bitmapset *
3048 7012 : adjust_view_column_set(Bitmapset *cols, List *targetlist)
3049 : {
3050 7012 : Bitmapset *result = NULL;
3051 : int col;
3052 :
3053 7012 : col = -1;
3054 12130 : while ((col = bms_next_member(cols, col)) >= 0)
3055 : {
3056 : /* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
3057 5118 : AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
3058 :
3059 5118 : if (attno == InvalidAttrNumber)
3060 : {
3061 : /*
3062 : * There's a whole-row reference to the view. For permissions
3063 : * purposes, treat it as a reference to each column available from
3064 : * the view. (We should *not* convert this to a whole-row
3065 : * reference to the base relation, since the view may not touch
3066 : * all columns of the base relation.)
3067 : */
3068 : ListCell *lc;
3069 :
3070 0 : foreach(lc, targetlist)
3071 : {
3072 0 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
3073 : Var *var;
3074 :
3075 0 : if (tle->resjunk)
3076 0 : continue;
3077 0 : var = castNode(Var, tle->expr);
3078 0 : result = bms_add_member(result,
3079 0 : var->varattno - FirstLowInvalidHeapAttributeNumber);
3080 : }
3081 : }
3082 : else
3083 : {
3084 : /*
3085 : * Views do not have system columns, so we do not expect to see
3086 : * any other system attnos here. If we do find one, the error
3087 : * case will apply.
3088 : */
3089 5118 : TargetEntry *tle = get_tle_by_resno(targetlist, attno);
3090 :
3091 5118 : if (tle != NULL && !tle->resjunk && IsA(tle->expr, Var))
3092 5118 : {
3093 5118 : Var *var = (Var *) tle->expr;
3094 :
3095 5118 : result = bms_add_member(result,
3096 5118 : var->varattno - FirstLowInvalidHeapAttributeNumber);
3097 : }
3098 : else
3099 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3100 : attno);
3101 : }
3102 : }
3103 :
3104 7012 : return result;
3105 : }
3106 :
3107 :
3108 : /*
3109 : * error_view_not_updatable -
3110 : * Report an error due to an attempt to update a non-updatable view.
3111 : *
3112 : * Generally this is expected to be called from the rewriter, with suitable
3113 : * error detail explaining why the view is not updatable. Note, however, that
3114 : * the executor also performs a just-in-case check that the target view is
3115 : * updatable. That check is expected to never fail, but if it does, it will
3116 : * call this function with NULL error detail --- see CheckValidResultRel().
3117 : *
3118 : * Note: for MERGE, at least one of the actions in mergeActionList is expected
3119 : * to lack a suitable INSTEAD OF trigger --- see view_has_instead_trigger().
3120 : */
3121 : void
3122 156 : error_view_not_updatable(Relation view,
3123 : CmdType command,
3124 : List *mergeActionList,
3125 : const char *detail)
3126 : {
3127 156 : TriggerDesc *trigDesc = view->trigdesc;
3128 :
3129 156 : switch (command)
3130 : {
3131 24 : case CMD_INSERT:
3132 24 : ereport(ERROR,
3133 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3134 : errmsg("cannot insert into view \"%s\"",
3135 : RelationGetRelationName(view)),
3136 : detail ? errdetail_internal("%s", _(detail)) : 0,
3137 : errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or an unconditional ON INSERT DO INSTEAD rule."));
3138 : break;
3139 54 : case CMD_UPDATE:
3140 54 : ereport(ERROR,
3141 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3142 : errmsg("cannot update view \"%s\"",
3143 : RelationGetRelationName(view)),
3144 : detail ? errdetail_internal("%s", _(detail)) : 0,
3145 : errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or an unconditional ON UPDATE DO INSTEAD rule."));
3146 : break;
3147 48 : case CMD_DELETE:
3148 48 : ereport(ERROR,
3149 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3150 : errmsg("cannot delete from view \"%s\"",
3151 : RelationGetRelationName(view)),
3152 : detail ? errdetail_internal("%s", _(detail)) : 0,
3153 : errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or an unconditional ON DELETE DO INSTEAD rule."));
3154 : break;
3155 30 : case CMD_MERGE:
3156 :
3157 : /*
3158 : * Note that the error hints here differ from above, since MERGE
3159 : * doesn't support rules.
3160 : */
3161 36 : foreach_node(MergeAction, action, mergeActionList)
3162 : {
3163 36 : switch (action->commandType)
3164 : {
3165 12 : case CMD_INSERT:
3166 12 : if (!trigDesc || !trigDesc->trig_insert_instead_row)
3167 12 : ereport(ERROR,
3168 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3169 : errmsg("cannot insert into view \"%s\"",
3170 : RelationGetRelationName(view)),
3171 : detail ? errdetail_internal("%s", _(detail)) : 0,
3172 : errhint("To enable inserting into the view using MERGE, provide an INSTEAD OF INSERT trigger."));
3173 0 : break;
3174 12 : case CMD_UPDATE:
3175 12 : if (!trigDesc || !trigDesc->trig_update_instead_row)
3176 6 : ereport(ERROR,
3177 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3178 : errmsg("cannot update view \"%s\"",
3179 : RelationGetRelationName(view)),
3180 : detail ? errdetail_internal("%s", _(detail)) : 0,
3181 : errhint("To enable updating the view using MERGE, provide an INSTEAD OF UPDATE trigger."));
3182 6 : break;
3183 12 : case CMD_DELETE:
3184 12 : if (!trigDesc || !trigDesc->trig_delete_instead_row)
3185 12 : ereport(ERROR,
3186 : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3187 : errmsg("cannot delete from view \"%s\"",
3188 : RelationGetRelationName(view)),
3189 : detail ? errdetail_internal("%s", _(detail)) : 0,
3190 : errhint("To enable deleting from the view using MERGE, provide an INSTEAD OF DELETE trigger."));
3191 0 : break;
3192 0 : case CMD_NOTHING:
3193 0 : break;
3194 0 : default:
3195 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
3196 : break;
3197 : }
3198 : }
3199 0 : break;
3200 0 : default:
3201 0 : elog(ERROR, "unrecognized CmdType: %d", (int) command);
3202 : break;
3203 : }
3204 0 : }
3205 :
3206 :
3207 : /*
3208 : * rewriteTargetView -
3209 : * Attempt to rewrite a query where the target relation is a view, so that
3210 : * the view's base relation becomes the target relation.
3211 : *
3212 : * Note that the base relation here may itself be a view, which may or may not
3213 : * have INSTEAD OF triggers or rules to handle the update. That is handled by
3214 : * the recursion in RewriteQuery.
3215 : */
3216 : static Query *
3217 3500 : rewriteTargetView(Query *parsetree, Relation view)
3218 : {
3219 : Query *viewquery;
3220 : bool insert_or_update;
3221 : const char *auto_update_detail;
3222 : RangeTblRef *rtr;
3223 : int base_rt_index;
3224 : int new_rt_index;
3225 : RangeTblEntry *base_rte;
3226 : RangeTblEntry *view_rte;
3227 : RangeTblEntry *new_rte;
3228 : RTEPermissionInfo *base_perminfo;
3229 : RTEPermissionInfo *view_perminfo;
3230 : RTEPermissionInfo *new_perminfo;
3231 : Relation base_rel;
3232 : List *view_targetlist;
3233 : ListCell *lc;
3234 :
3235 : /*
3236 : * Get the Query from the view's ON SELECT rule. We're going to munge the
3237 : * Query to change the view's base relation into the target relation,
3238 : * along with various other changes along the way, so we need to make a
3239 : * copy of it (get_view_query() returns a pointer into the relcache, so we
3240 : * have to treat it as read-only).
3241 : */
3242 3500 : viewquery = copyObject(get_view_query(view));
3243 :
3244 : /* Locate RTE and perminfo describing the view in the outer query */
3245 3500 : view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
3246 3500 : view_perminfo = getRTEPermissionInfo(parsetree->rteperminfos, view_rte);
3247 :
3248 : /*
3249 : * Are we doing INSERT/UPDATE, or MERGE containing INSERT/UPDATE? If so,
3250 : * various additional checks on the view columns need to be applied, and
3251 : * any view CHECK OPTIONs need to be enforced.
3252 : */
3253 3500 : insert_or_update =
3254 5788 : (parsetree->commandType == CMD_INSERT ||
3255 2288 : parsetree->commandType == CMD_UPDATE);
3256 :
3257 3500 : if (parsetree->commandType == CMD_MERGE)
3258 : {
3259 1926 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3260 : {
3261 942 : if (action->commandType == CMD_INSERT ||
3262 834 : action->commandType == CMD_UPDATE)
3263 : {
3264 804 : insert_or_update = true;
3265 804 : break;
3266 : }
3267 : }
3268 : }
3269 :
3270 : /* Check if the expansion of non-system views are restricted */
3271 3500 : if (unlikely((restrict_nonsystem_relation_kind & RESTRICT_RELKIND_VIEW) != 0 &&
3272 : RelationGetRelid(view) >= FirstNormalObjectId))
3273 6 : ereport(ERROR,
3274 : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3275 : errmsg("access to non-system view \"%s\" is restricted",
3276 : RelationGetRelationName(view))));
3277 :
3278 : /*
3279 : * The view must be updatable, else fail.
3280 : *
3281 : * If we are doing INSERT/UPDATE (or MERGE containing INSERT/UPDATE), we
3282 : * also check that there is at least one updatable column.
3283 : */
3284 : auto_update_detail =
3285 3494 : view_query_is_auto_updatable(viewquery, insert_or_update);
3286 :
3287 3494 : if (auto_update_detail)
3288 138 : error_view_not_updatable(view,
3289 : parsetree->commandType,
3290 : parsetree->mergeActionList,
3291 : auto_update_detail);
3292 :
3293 : /*
3294 : * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE) the modified
3295 : * columns must all be updatable.
3296 : */
3297 3356 : if (insert_or_update)
3298 : {
3299 : Bitmapset *modified_cols;
3300 : char *non_updatable_col;
3301 :
3302 : /*
3303 : * Compute the set of modified columns as those listed in the result
3304 : * RTE's insertedCols and/or updatedCols sets plus those that are
3305 : * targets of the query's targetlist(s). We must consider the query's
3306 : * targetlist because rewriteTargetListIU may have added additional
3307 : * targetlist entries for view defaults, and these must also be
3308 : * updatable. But rewriteTargetListIU can also remove entries if they
3309 : * are DEFAULT markers and the column's default is NULL, so
3310 : * considering only the targetlist would also be wrong.
3311 : */
3312 2972 : modified_cols = bms_union(view_perminfo->insertedCols,
3313 2972 : view_perminfo->updatedCols);
3314 :
3315 6254 : foreach(lc, parsetree->targetList)
3316 : {
3317 3282 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3318 :
3319 3282 : if (!tle->resjunk)
3320 3282 : modified_cols = bms_add_member(modified_cols,
3321 3282 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3322 : }
3323 :
3324 2972 : if (parsetree->onConflict)
3325 : {
3326 336 : foreach(lc, parsetree->onConflict->onConflictSet)
3327 : {
3328 156 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3329 :
3330 156 : if (!tle->resjunk)
3331 156 : modified_cols = bms_add_member(modified_cols,
3332 156 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3333 : }
3334 : }
3335 :
3336 6922 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3337 : {
3338 978 : if (action->commandType == CMD_INSERT ||
3339 768 : action->commandType == CMD_UPDATE)
3340 : {
3341 2946 : foreach_node(TargetEntry, tle, action->targetList)
3342 : {
3343 1134 : if (!tle->resjunk)
3344 1134 : modified_cols = bms_add_member(modified_cols,
3345 1134 : tle->resno - FirstLowInvalidHeapAttributeNumber);
3346 : }
3347 : }
3348 : }
3349 :
3350 2972 : auto_update_detail = view_cols_are_auto_updatable(viewquery,
3351 : modified_cols,
3352 : NULL,
3353 : &non_updatable_col);
3354 2972 : if (auto_update_detail)
3355 : {
3356 : /*
3357 : * This is a different error, caused by an attempt to update a
3358 : * non-updatable column in an otherwise updatable view.
3359 : */
3360 120 : switch (parsetree->commandType)
3361 : {
3362 72 : case CMD_INSERT:
3363 72 : ereport(ERROR,
3364 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3365 : errmsg("cannot insert into column \"%s\" of view \"%s\"",
3366 : non_updatable_col,
3367 : RelationGetRelationName(view)),
3368 : errdetail_internal("%s", _(auto_update_detail))));
3369 : break;
3370 42 : case CMD_UPDATE:
3371 42 : ereport(ERROR,
3372 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3373 : errmsg("cannot update column \"%s\" of view \"%s\"",
3374 : non_updatable_col,
3375 : RelationGetRelationName(view)),
3376 : errdetail_internal("%s", _(auto_update_detail))));
3377 : break;
3378 6 : case CMD_MERGE:
3379 6 : ereport(ERROR,
3380 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3381 : errmsg("cannot merge into column \"%s\" of view \"%s\"",
3382 : non_updatable_col,
3383 : RelationGetRelationName(view)),
3384 : errdetail_internal("%s", _(auto_update_detail))));
3385 : break;
3386 0 : default:
3387 0 : elog(ERROR, "unrecognized CmdType: %d",
3388 : (int) parsetree->commandType);
3389 : break;
3390 : }
3391 : }
3392 : }
3393 :
3394 : /*
3395 : * For MERGE, there must not be any INSTEAD OF triggers on an otherwise
3396 : * updatable view. The caller already checked that there isn't a full set
3397 : * of INSTEAD OF triggers, so this is to guard against having a partial
3398 : * set (mixing auto-update and trigger-update actions in a single command
3399 : * isn't supported).
3400 : */
3401 3236 : if (parsetree->commandType == CMD_MERGE)
3402 : {
3403 2748 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3404 : {
3405 2088 : if (action->commandType != CMD_NOTHING &&
3406 1044 : view_has_instead_trigger(view, action->commandType, NIL))
3407 6 : ereport(ERROR,
3408 : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3409 : errmsg("cannot merge into view \"%s\"",
3410 : RelationGetRelationName(view)),
3411 : errdetail("MERGE is not supported for views with INSTEAD OF triggers for some actions but not all."),
3412 : errhint("To enable merging into the view, either provide a full set of INSTEAD OF triggers or drop the existing INSTEAD OF triggers."));
3413 : }
3414 : }
3415 :
3416 : /*
3417 : * If we get here, view_query_is_auto_updatable() has verified that the
3418 : * view contains a single base relation.
3419 : */
3420 : Assert(list_length(viewquery->jointree->fromlist) == 1);
3421 3230 : rtr = linitial_node(RangeTblRef, viewquery->jointree->fromlist);
3422 :
3423 3230 : base_rt_index = rtr->rtindex;
3424 3230 : base_rte = rt_fetch(base_rt_index, viewquery->rtable);
3425 : Assert(base_rte->rtekind == RTE_RELATION);
3426 3230 : base_perminfo = getRTEPermissionInfo(viewquery->rteperminfos, base_rte);
3427 :
3428 : /*
3429 : * Up to now, the base relation hasn't been touched at all in our query.
3430 : * We need to acquire lock on it before we try to do anything with it.
3431 : * (The subsequent recursive call of RewriteQuery will suppose that we
3432 : * already have the right lock!) Since it will become the query target
3433 : * relation, RowExclusiveLock is always the right thing.
3434 : */
3435 3230 : base_rel = table_open(base_rte->relid, RowExclusiveLock);
3436 :
3437 : /*
3438 : * While we have the relation open, update the RTE's relkind, just in case
3439 : * it changed since this view was made (cf. AcquireRewriteLocks).
3440 : */
3441 3230 : base_rte->relkind = base_rel->rd_rel->relkind;
3442 :
3443 : /*
3444 : * If the view query contains any sublink subqueries then we need to also
3445 : * acquire locks on any relations they refer to. We know that there won't
3446 : * be any subqueries in the range table or CTEs, so we can skip those, as
3447 : * in AcquireRewriteLocks.
3448 : */
3449 3230 : if (viewquery->hasSubLinks)
3450 : {
3451 : acquireLocksOnSubLinks_context context;
3452 :
3453 258 : context.for_execute = true;
3454 258 : query_tree_walker(viewquery, acquireLocksOnSubLinks, &context,
3455 : QTW_IGNORE_RC_SUBQUERIES);
3456 : }
3457 :
3458 : /*
3459 : * Create a new target RTE describing the base relation, and add it to the
3460 : * outer query's rangetable. (What's happening in the next few steps is
3461 : * very much like what the planner would do to "pull up" the view into the
3462 : * outer query. Perhaps someday we should refactor things enough so that
3463 : * we can share code with the planner.)
3464 : *
3465 : * Be sure to set rellockmode to the correct thing for the target table.
3466 : * Since we copied the whole viewquery above, we can just scribble on
3467 : * base_rte instead of copying it.
3468 : */
3469 3230 : new_rte = base_rte;
3470 3230 : new_rte->rellockmode = RowExclusiveLock;
3471 :
3472 3230 : parsetree->rtable = lappend(parsetree->rtable, new_rte);
3473 3230 : new_rt_index = list_length(parsetree->rtable);
3474 :
3475 : /*
3476 : * INSERTs never inherit. For UPDATE/DELETE/MERGE, we use the view
3477 : * query's inheritance flag for the base relation.
3478 : */
3479 3230 : if (parsetree->commandType == CMD_INSERT)
3480 1116 : new_rte->inh = false;
3481 :
3482 : /*
3483 : * Adjust the view's targetlist Vars to reference the new target RTE, ie
3484 : * make their varnos be new_rt_index instead of base_rt_index. There can
3485 : * be no Vars for other rels in the tlist, so this is sufficient to pull
3486 : * up the tlist expressions for use in the outer query. The tlist will
3487 : * provide the replacement expressions used by ReplaceVarsFromTargetList
3488 : * below.
3489 : */
3490 3230 : view_targetlist = viewquery->targetList;
3491 :
3492 3230 : ChangeVarNodes((Node *) view_targetlist,
3493 : base_rt_index,
3494 : new_rt_index,
3495 : 0);
3496 :
3497 : /*
3498 : * If the view has "security_invoker" set, mark the new target relation
3499 : * for the permissions checks that we want to enforce against the query
3500 : * caller. Otherwise we want to enforce them against the view owner.
3501 : *
3502 : * At the relation level, require the same INSERT/UPDATE/DELETE
3503 : * permissions that the query caller needs against the view. We drop the
3504 : * ACL_SELECT bit that is presumably in new_perminfo->requiredPerms
3505 : * initially.
3506 : *
3507 : * Note: the original view's RTEPermissionInfo remains in the query's
3508 : * rteperminfos so that the executor still performs appropriate
3509 : * permissions checks for the query caller's use of the view.
3510 : *
3511 : * Disregard the perminfo in viewquery->rteperminfos that the base_rte
3512 : * would currently be pointing at, because we'd like it to point now to a
3513 : * new one that will be filled below. Must set perminfoindex to 0 to not
3514 : * trip over the Assert in addRTEPermissionInfo().
3515 : */
3516 3230 : new_rte->perminfoindex = 0;
3517 3230 : new_perminfo = addRTEPermissionInfo(&parsetree->rteperminfos, new_rte);
3518 3230 : if (RelationHasSecurityInvoker(view))
3519 486 : new_perminfo->checkAsUser = InvalidOid;
3520 : else
3521 2744 : new_perminfo->checkAsUser = view->rd_rel->relowner;
3522 3230 : new_perminfo->requiredPerms = view_perminfo->requiredPerms;
3523 :
3524 : /*
3525 : * Now for the per-column permissions bits.
3526 : *
3527 : * Initially, new_perminfo (base_perminfo) contains selectedCols
3528 : * permission check bits for all base-rel columns referenced by the view,
3529 : * but since the view is a SELECT query its insertedCols/updatedCols is
3530 : * empty. We set insertedCols and updatedCols to include all the columns
3531 : * the outer query is trying to modify, adjusting the column numbers as
3532 : * needed. But we leave selectedCols as-is, so the view owner must have
3533 : * read permission for all columns used in the view definition, even if
3534 : * some of them are not read by the outer query. We could try to limit
3535 : * selectedCols to only columns used in the transformed query, but that
3536 : * does not correspond to what happens in ordinary SELECT usage of a view:
3537 : * all referenced columns must have read permission, even if optimization
3538 : * finds that some of them can be discarded during query transformation.
3539 : * The flattening we're doing here is an optional optimization, too. (If
3540 : * you are unpersuaded and want to change this, note that applying
3541 : * adjust_view_column_set to view_perminfo->selectedCols is clearly *not*
3542 : * the right answer, since that neglects base-rel columns used in the
3543 : * view's WHERE quals.)
3544 : *
3545 : * This step needs the modified view targetlist, so we have to do things
3546 : * in this order.
3547 : */
3548 : Assert(bms_is_empty(new_perminfo->insertedCols) &&
3549 : bms_is_empty(new_perminfo->updatedCols));
3550 :
3551 3230 : new_perminfo->selectedCols = base_perminfo->selectedCols;
3552 :
3553 3230 : new_perminfo->insertedCols =
3554 3230 : adjust_view_column_set(view_perminfo->insertedCols, view_targetlist);
3555 :
3556 3230 : new_perminfo->updatedCols =
3557 3230 : adjust_view_column_set(view_perminfo->updatedCols, view_targetlist);
3558 :
3559 : /*
3560 : * Move any security barrier quals from the view RTE onto the new target
3561 : * RTE. Any such quals should now apply to the new target RTE and will
3562 : * not reference the original view RTE in the rewritten query.
3563 : */
3564 3230 : new_rte->securityQuals = view_rte->securityQuals;
3565 3230 : view_rte->securityQuals = NIL;
3566 :
3567 : /*
3568 : * Now update all Vars in the outer query that reference the view to
3569 : * reference the appropriate column of the base relation instead.
3570 : */
3571 : parsetree = (Query *)
3572 3230 : ReplaceVarsFromTargetList((Node *) parsetree,
3573 : parsetree->resultRelation,
3574 : 0,
3575 : view_rte,
3576 : view_targetlist,
3577 : new_rt_index,
3578 : REPLACEVARS_REPORT_ERROR,
3579 : 0,
3580 : NULL);
3581 :
3582 : /*
3583 : * Update all other RTI references in the query that point to the view
3584 : * (for example, parsetree->resultRelation itself) to point to the new
3585 : * base relation instead. Vars will not be affected since none of them
3586 : * reference parsetree->resultRelation any longer.
3587 : */
3588 3230 : ChangeVarNodes((Node *) parsetree,
3589 : parsetree->resultRelation,
3590 : new_rt_index,
3591 : 0);
3592 : Assert(parsetree->resultRelation == new_rt_index);
3593 :
3594 : /*
3595 : * For INSERT/UPDATE we must also update resnos in the targetlist to refer
3596 : * to columns of the base relation, since those indicate the target
3597 : * columns to be affected. Similarly, for MERGE we must update the resnos
3598 : * in the merge action targetlists of any INSERT/UPDATE actions.
3599 : *
3600 : * Note that this destroys the resno ordering of the targetlists, but that
3601 : * will be fixed when we recurse through RewriteQuery, which will invoke
3602 : * rewriteTargetListIU again on the updated targetlists.
3603 : */
3604 3230 : if (parsetree->commandType != CMD_DELETE)
3605 : {
3606 5984 : foreach(lc, parsetree->targetList)
3607 : {
3608 3054 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3609 : TargetEntry *view_tle;
3610 :
3611 3054 : if (tle->resjunk)
3612 0 : continue;
3613 :
3614 3054 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3615 3054 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3616 3054 : tle->resno = ((Var *) view_tle->expr)->varattno;
3617 : else
3618 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3619 : tle->resno);
3620 : }
3621 :
3622 6898 : foreach_node(MergeAction, action, parsetree->mergeActionList)
3623 : {
3624 1038 : if (action->commandType == CMD_INSERT ||
3625 840 : action->commandType == CMD_UPDATE)
3626 : {
3627 2856 : foreach_node(TargetEntry, tle, action->targetList)
3628 : {
3629 : TargetEntry *view_tle;
3630 :
3631 1092 : if (tle->resjunk)
3632 0 : continue;
3633 :
3634 1092 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3635 1092 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3636 1092 : tle->resno = ((Var *) view_tle->expr)->varattno;
3637 : else
3638 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3639 : tle->resno);
3640 : }
3641 : }
3642 : }
3643 : }
3644 :
3645 : /*
3646 : * For INSERT .. ON CONFLICT .. DO UPDATE, we must also update assorted
3647 : * stuff in the onConflict data structure.
3648 : */
3649 3230 : if (parsetree->onConflict &&
3650 168 : parsetree->onConflict->action == ONCONFLICT_UPDATE)
3651 : {
3652 : Index old_exclRelIndex,
3653 : new_exclRelIndex;
3654 : ParseNamespaceItem *new_exclNSItem;
3655 : RangeTblEntry *new_exclRte;
3656 : List *tmp_tlist;
3657 :
3658 : /*
3659 : * Like the INSERT/UPDATE code above, update the resnos in the
3660 : * auxiliary UPDATE targetlist to refer to columns of the base
3661 : * relation.
3662 : */
3663 288 : foreach(lc, parsetree->onConflict->onConflictSet)
3664 : {
3665 144 : TargetEntry *tle = (TargetEntry *) lfirst(lc);
3666 : TargetEntry *view_tle;
3667 :
3668 144 : if (tle->resjunk)
3669 0 : continue;
3670 :
3671 144 : view_tle = get_tle_by_resno(view_targetlist, tle->resno);
3672 144 : if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
3673 144 : tle->resno = ((Var *) view_tle->expr)->varattno;
3674 : else
3675 0 : elog(ERROR, "attribute number %d not found in view targetlist",
3676 : tle->resno);
3677 : }
3678 :
3679 : /*
3680 : * Also, create a new RTE for the EXCLUDED pseudo-relation, using the
3681 : * query's new base rel (which may well have a different column list
3682 : * from the view, hence we need a new column alias list). This should
3683 : * match transformOnConflictClause. In particular, note that the
3684 : * relkind is set to composite to signal that we're not dealing with
3685 : * an actual relation.
3686 : */
3687 144 : old_exclRelIndex = parsetree->onConflict->exclRelIndex;
3688 :
3689 144 : new_exclNSItem = addRangeTableEntryForRelation(make_parsestate(NULL),
3690 : base_rel,
3691 : RowExclusiveLock,
3692 : makeAlias("excluded", NIL),
3693 : false, false);
3694 144 : new_exclRte = new_exclNSItem->p_rte;
3695 144 : new_exclRte->relkind = RELKIND_COMPOSITE_TYPE;
3696 : /* Ignore the RTEPermissionInfo that would've been added. */
3697 144 : new_exclRte->perminfoindex = 0;
3698 :
3699 144 : parsetree->rtable = lappend(parsetree->rtable, new_exclRte);
3700 288 : new_exclRelIndex = parsetree->onConflict->exclRelIndex =
3701 144 : list_length(parsetree->rtable);
3702 :
3703 : /*
3704 : * Replace the targetlist for the EXCLUDED pseudo-relation with a new
3705 : * one, representing the columns from the new base relation.
3706 : */
3707 288 : parsetree->onConflict->exclRelTlist =
3708 144 : BuildOnConflictExcludedTargetlist(base_rel, new_exclRelIndex);
3709 :
3710 : /*
3711 : * Update all Vars in the ON CONFLICT clause that refer to the old
3712 : * EXCLUDED pseudo-relation. We want to use the column mappings
3713 : * defined in the view targetlist, but we need the outputs to refer to
3714 : * the new EXCLUDED pseudo-relation rather than the new target RTE.
3715 : * Also notice that "EXCLUDED.*" will be expanded using the view's
3716 : * rowtype, which seems correct.
3717 : */
3718 144 : tmp_tlist = copyObject(view_targetlist);
3719 :
3720 144 : ChangeVarNodes((Node *) tmp_tlist, new_rt_index,
3721 : new_exclRelIndex, 0);
3722 :
3723 144 : parsetree->onConflict = (OnConflictExpr *)
3724 144 : ReplaceVarsFromTargetList((Node *) parsetree->onConflict,
3725 : old_exclRelIndex,
3726 : 0,
3727 : view_rte,
3728 : tmp_tlist,
3729 : new_rt_index,
3730 : REPLACEVARS_REPORT_ERROR,
3731 : 0,
3732 : &parsetree->hasSubLinks);
3733 : }
3734 :
3735 : /*
3736 : * For UPDATE/DELETE/MERGE, pull up any WHERE quals from the view. We
3737 : * know that any Vars in the quals must reference the one base relation,
3738 : * so we need only adjust their varnos to reference the new target (just
3739 : * the same as we did with the view targetlist).
3740 : *
3741 : * If it's a security-barrier view, its WHERE quals must be applied before
3742 : * quals from the outer query, so we attach them to the RTE as security
3743 : * barrier quals rather than adding them to the main WHERE clause.
3744 : *
3745 : * For INSERT, the view's quals can be ignored in the main query.
3746 : */
3747 3230 : if (parsetree->commandType != CMD_INSERT &&
3748 2114 : viewquery->jointree->quals != NULL)
3749 : {
3750 758 : Node *viewqual = (Node *) viewquery->jointree->quals;
3751 :
3752 : /*
3753 : * Even though we copied viewquery already at the top of this
3754 : * function, we must duplicate the viewqual again here, because we may
3755 : * need to use the quals again below for a WithCheckOption clause.
3756 : */
3757 758 : viewqual = copyObject(viewqual);
3758 :
3759 758 : ChangeVarNodes(viewqual, base_rt_index, new_rt_index, 0);
3760 :
3761 758 : if (RelationIsSecurityView(view))
3762 : {
3763 : /*
3764 : * The view's quals go in front of existing barrier quals: those
3765 : * would have come from an outer level of security-barrier view,
3766 : * and so must get evaluated later.
3767 : *
3768 : * Note: the parsetree has been mutated, so the new_rte pointer is
3769 : * stale and needs to be re-computed.
3770 : */
3771 234 : new_rte = rt_fetch(new_rt_index, parsetree->rtable);
3772 234 : new_rte->securityQuals = lcons(viewqual, new_rte->securityQuals);
3773 :
3774 : /*
3775 : * Do not set parsetree->hasRowSecurity, because these aren't RLS
3776 : * conditions (they aren't affected by enabling/disabling RLS).
3777 : */
3778 :
3779 : /*
3780 : * Make sure that the query is marked correctly if the added qual
3781 : * has sublinks.
3782 : */
3783 234 : if (!parsetree->hasSubLinks)
3784 210 : parsetree->hasSubLinks = checkExprHasSubLink(viewqual);
3785 : }
3786 : else
3787 524 : AddQual(parsetree, (Node *) viewqual);
3788 : }
3789 :
3790 : /*
3791 : * For INSERT/UPDATE (or MERGE containing INSERT/UPDATE), if the view has
3792 : * the WITH CHECK OPTION, or any parent view specified WITH CASCADED CHECK
3793 : * OPTION, add the quals from the view to the query's withCheckOptions
3794 : * list.
3795 : */
3796 3230 : if (insert_or_update)
3797 : {
3798 2846 : bool has_wco = RelationHasCheckOption(view);
3799 2846 : bool cascaded = RelationHasCascadedCheckOption(view);
3800 :
3801 : /*
3802 : * If the parent view has a cascaded check option, treat this view as
3803 : * if it also had a cascaded check option.
3804 : *
3805 : * New WithCheckOptions are added to the start of the list, so if
3806 : * there is a cascaded check option, it will be the first item in the
3807 : * list.
3808 : */
3809 2846 : if (parsetree->withCheckOptions != NIL)
3810 : {
3811 114 : WithCheckOption *parent_wco =
3812 114 : (WithCheckOption *) linitial(parsetree->withCheckOptions);
3813 :
3814 114 : if (parent_wco->cascaded)
3815 : {
3816 90 : has_wco = true;
3817 90 : cascaded = true;
3818 : }
3819 : }
3820 :
3821 : /*
3822 : * Add the new WithCheckOption to the start of the list, so that
3823 : * checks on inner views are run before checks on outer views, as
3824 : * required by the SQL standard.
3825 : *
3826 : * If the new check is CASCADED, we need to add it even if this view
3827 : * has no quals, since there may be quals on child views. A LOCAL
3828 : * check can be omitted if this view has no quals.
3829 : */
3830 2846 : if (has_wco && (cascaded || viewquery->jointree->quals != NULL))
3831 : {
3832 : WithCheckOption *wco;
3833 :
3834 656 : wco = makeNode(WithCheckOption);
3835 656 : wco->kind = WCO_VIEW_CHECK;
3836 656 : wco->relname = pstrdup(RelationGetRelationName(view));
3837 656 : wco->polname = NULL;
3838 656 : wco->qual = NULL;
3839 656 : wco->cascaded = cascaded;
3840 :
3841 656 : parsetree->withCheckOptions = lcons(wco,
3842 : parsetree->withCheckOptions);
3843 :
3844 656 : if (viewquery->jointree->quals != NULL)
3845 : {
3846 596 : wco->qual = (Node *) viewquery->jointree->quals;
3847 596 : ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
3848 :
3849 : /*
3850 : * For INSERT, make sure that the query is marked correctly if
3851 : * the added qual has sublinks. This can be skipped for
3852 : * UPDATE/MERGE, since the same qual will have already been
3853 : * added above, and the check will already have been done.
3854 : */
3855 596 : if (!parsetree->hasSubLinks &&
3856 500 : parsetree->commandType == CMD_INSERT)
3857 312 : parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
3858 : }
3859 : }
3860 : }
3861 :
3862 3230 : table_close(base_rel, NoLock);
3863 :
3864 3230 : return parsetree;
3865 : }
3866 :
3867 :
3868 : /*
3869 : * RewriteQuery -
3870 : * rewrites the query and apply the rules again on the queries rewritten
3871 : *
3872 : * rewrite_events is a list of open query-rewrite actions, so we can detect
3873 : * infinite recursion.
3874 : *
3875 : * orig_rt_length is the length of the originating query's rtable, for product
3876 : * queries created by fireRules(), and 0 otherwise. This is used to skip any
3877 : * already-processed VALUES RTEs from the original query.
3878 : *
3879 : * num_ctes_processed is the number of CTEs at the end of the query's cteList
3880 : * that have already been rewritten, and must not be rewritten again.
3881 : */
3882 : static List *
3883 448126 : RewriteQuery(Query *parsetree, List *rewrite_events, int orig_rt_length,
3884 : int num_ctes_processed)
3885 : {
3886 448126 : CmdType event = parsetree->commandType;
3887 448126 : bool instead = false;
3888 448126 : bool returning = false;
3889 448126 : bool updatableview = false;
3890 448126 : Query *qual_product = NULL;
3891 448126 : List *rewritten = NIL;
3892 : ListCell *lc1;
3893 :
3894 : /*
3895 : * First, recursively process any insert/update/delete/merge statements in
3896 : * WITH clauses. (We have to do this first because the WITH clauses may
3897 : * get copied into rule actions below.)
3898 : *
3899 : * Any new WITH clauses from rule actions are processed when we recurse
3900 : * into product queries below. However, when recursing, we must take care
3901 : * to avoid rewriting a CTE query more than once (because expanding
3902 : * generated columns in the targetlist more than once would fail). Since
3903 : * new CTEs from product queries are added to the start of the list (see
3904 : * rewriteRuleAction), we just skip the last num_ctes_processed items.
3905 : */
3906 451704 : foreach(lc1, parsetree->cteList)
3907 : {
3908 3650 : CommonTableExpr *cte = lfirst_node(CommonTableExpr, lc1);
3909 3650 : Query *ctequery = castNode(Query, cte->ctequery);
3910 3650 : int i = foreach_current_index(lc1);
3911 : List *newstuff;
3912 :
3913 : /* Skip already-processed CTEs at the end of the list */
3914 3650 : if (i >= list_length(parsetree->cteList) - num_ctes_processed)
3915 42 : break;
3916 :
3917 3608 : if (ctequery->commandType == CMD_SELECT)
3918 3250 : continue;
3919 :
3920 358 : newstuff = RewriteQuery(ctequery, rewrite_events, 0, 0);
3921 :
3922 : /*
3923 : * Currently we can only handle unconditional, single-statement DO
3924 : * INSTEAD rules correctly; we have to get exactly one non-utility
3925 : * Query out of the rewrite operation to stuff back into the CTE node.
3926 : */
3927 358 : if (list_length(newstuff) == 1)
3928 : {
3929 : /* Must check it's not a utility command */
3930 334 : ctequery = linitial_node(Query, newstuff);
3931 334 : if (!(ctequery->commandType == CMD_SELECT ||
3932 334 : ctequery->commandType == CMD_UPDATE ||
3933 244 : ctequery->commandType == CMD_INSERT ||
3934 76 : ctequery->commandType == CMD_DELETE ||
3935 34 : ctequery->commandType == CMD_MERGE))
3936 : {
3937 : /*
3938 : * Currently it could only be NOTIFY; this error message will
3939 : * need work if we ever allow other utility commands in rules.
3940 : */
3941 6 : ereport(ERROR,
3942 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3943 : errmsg("DO INSTEAD NOTIFY rules are not supported for data-modifying statements in WITH")));
3944 : }
3945 : /* WITH queries should never be canSetTag */
3946 : Assert(!ctequery->canSetTag);
3947 : /* Push the single Query back into the CTE node */
3948 328 : cte->ctequery = (Node *) ctequery;
3949 : }
3950 24 : else if (newstuff == NIL)
3951 : {
3952 6 : ereport(ERROR,
3953 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3954 : errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
3955 : }
3956 : else
3957 : {
3958 : ListCell *lc2;
3959 :
3960 : /* examine queries to determine which error message to issue */
3961 42 : foreach(lc2, newstuff)
3962 : {
3963 36 : Query *q = (Query *) lfirst(lc2);
3964 :
3965 36 : if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
3966 6 : ereport(ERROR,
3967 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3968 : errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in WITH")));
3969 30 : if (q->querySource == QSRC_NON_INSTEAD_RULE)
3970 6 : ereport(ERROR,
3971 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3972 : errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
3973 : }
3974 :
3975 6 : ereport(ERROR,
3976 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
3977 : errmsg("multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
3978 : }
3979 : }
3980 448096 : num_ctes_processed = list_length(parsetree->cteList);
3981 :
3982 : /*
3983 : * If the statement is an insert, update, delete, or merge, adjust its
3984 : * targetlist as needed, and then fire INSERT/UPDATE/DELETE rules on it.
3985 : *
3986 : * SELECT rules are handled later when we have all the queries that should
3987 : * get executed. Also, utilities aren't rewritten at all (do we still
3988 : * need that check?)
3989 : */
3990 448096 : if (event != CMD_SELECT && event != CMD_UTILITY)
3991 : {
3992 : int result_relation;
3993 : RangeTblEntry *rt_entry;
3994 : Relation rt_entry_relation;
3995 : List *locks;
3996 : int product_orig_rt_length;
3997 : List *product_queries;
3998 91714 : bool hasUpdate = false;
3999 91714 : int values_rte_index = 0;
4000 91714 : bool defaults_remaining = false;
4001 :
4002 91714 : result_relation = parsetree->resultRelation;
4003 : Assert(result_relation != 0);
4004 91714 : rt_entry = rt_fetch(result_relation, parsetree->rtable);
4005 : Assert(rt_entry->rtekind == RTE_RELATION);
4006 :
4007 : /*
4008 : * We can use NoLock here since either the parser or
4009 : * AcquireRewriteLocks should have locked the rel already.
4010 : */
4011 91714 : rt_entry_relation = table_open(rt_entry->relid, NoLock);
4012 :
4013 : /*
4014 : * Rewrite the targetlist as needed for the command type.
4015 : */
4016 91714 : if (event == CMD_INSERT)
4017 : {
4018 : ListCell *lc2;
4019 68984 : RangeTblEntry *values_rte = NULL;
4020 :
4021 : /*
4022 : * Test if it's a multi-row INSERT ... VALUES (...), (...), ... by
4023 : * looking for a VALUES RTE in the fromlist. For product queries,
4024 : * we must ignore any already-processed VALUES RTEs from the
4025 : * original query. These appear at the start of the rangetable.
4026 : */
4027 81512 : foreach(lc2, parsetree->jointree->fromlist)
4028 : {
4029 12528 : RangeTblRef *rtr = (RangeTblRef *) lfirst(lc2);
4030 :
4031 12528 : if (IsA(rtr, RangeTblRef) && rtr->rtindex > orig_rt_length)
4032 : {
4033 12204 : RangeTblEntry *rte = rt_fetch(rtr->rtindex,
4034 : parsetree->rtable);
4035 :
4036 12204 : if (rte->rtekind == RTE_VALUES)
4037 : {
4038 : /* should not find more than one VALUES RTE */
4039 4900 : if (values_rte != NULL)
4040 0 : elog(ERROR, "more than one VALUES RTE found");
4041 :
4042 4900 : values_rte = rte;
4043 4900 : values_rte_index = rtr->rtindex;
4044 : }
4045 : }
4046 : }
4047 :
4048 68984 : if (values_rte)
4049 : {
4050 4900 : Bitmapset *unused_values_attrnos = NULL;
4051 :
4052 : /* Process the main targetlist ... */
4053 4900 : parsetree->targetList = rewriteTargetListIU(parsetree->targetList,
4054 : parsetree->commandType,
4055 : parsetree->override,
4056 : rt_entry_relation,
4057 : values_rte,
4058 : values_rte_index,
4059 : &unused_values_attrnos);
4060 : /* ... and the VALUES expression lists */
4061 4798 : if (!rewriteValuesRTE(parsetree, values_rte, values_rte_index,
4062 : rt_entry_relation,
4063 : unused_values_attrnos))
4064 78 : defaults_remaining = true;
4065 : }
4066 : else
4067 : {
4068 : /* Process just the main targetlist */
4069 64006 : parsetree->targetList =
4070 64084 : rewriteTargetListIU(parsetree->targetList,
4071 : parsetree->commandType,
4072 : parsetree->override,
4073 : rt_entry_relation,
4074 : NULL, 0, NULL);
4075 : }
4076 :
4077 68804 : if (parsetree->onConflict &&
4078 2104 : parsetree->onConflict->action == ONCONFLICT_UPDATE)
4079 : {
4080 1500 : parsetree->onConflict->onConflictSet =
4081 1500 : rewriteTargetListIU(parsetree->onConflict->onConflictSet,
4082 : CMD_UPDATE,
4083 : parsetree->override,
4084 : rt_entry_relation,
4085 : NULL, 0, NULL);
4086 : }
4087 : }
4088 22730 : else if (event == CMD_UPDATE)
4089 : {
4090 : Assert(parsetree->override == OVERRIDING_NOT_SET);
4091 14998 : parsetree->targetList =
4092 15028 : rewriteTargetListIU(parsetree->targetList,
4093 : parsetree->commandType,
4094 : parsetree->override,
4095 : rt_entry_relation,
4096 : NULL, 0, NULL);
4097 : }
4098 7702 : else if (event == CMD_MERGE)
4099 : {
4100 : Assert(parsetree->override == OVERRIDING_NOT_SET);
4101 :
4102 : /*
4103 : * Rewrite each action targetlist separately
4104 : */
4105 7062 : foreach(lc1, parsetree->mergeActionList)
4106 : {
4107 4182 : MergeAction *action = (MergeAction *) lfirst(lc1);
4108 :
4109 4182 : switch (action->commandType)
4110 : {
4111 752 : case CMD_NOTHING:
4112 : case CMD_DELETE: /* Nothing to do here */
4113 752 : break;
4114 3430 : case CMD_UPDATE:
4115 : case CMD_INSERT:
4116 :
4117 : /*
4118 : * MERGE actions do not permit multi-row INSERTs, so
4119 : * there is no VALUES RTE to deal with here.
4120 : */
4121 3424 : action->targetList =
4122 3430 : rewriteTargetListIU(action->targetList,
4123 : action->commandType,
4124 : action->override,
4125 : rt_entry_relation,
4126 : NULL, 0, NULL);
4127 3424 : break;
4128 0 : default:
4129 0 : elog(ERROR, "unrecognized commandType: %d", action->commandType);
4130 : break;
4131 : }
4132 : }
4133 : }
4134 4816 : else if (event == CMD_DELETE)
4135 : {
4136 : /* Nothing to do here */
4137 : }
4138 : else
4139 0 : elog(ERROR, "unrecognized commandType: %d", (int) event);
4140 :
4141 : /*
4142 : * Collect and apply the appropriate rules.
4143 : */
4144 91498 : locks = matchLocks(event, rt_entry_relation,
4145 : result_relation, parsetree, &hasUpdate);
4146 :
4147 91480 : product_orig_rt_length = list_length(parsetree->rtable);
4148 91480 : product_queries = fireRules(parsetree,
4149 : result_relation,
4150 : event,
4151 : locks,
4152 : &instead,
4153 : &returning,
4154 : &qual_product);
4155 :
4156 : /*
4157 : * If we have a VALUES RTE with any remaining untouched DEFAULT items,
4158 : * and we got any product queries, finalize the VALUES RTE for each
4159 : * product query (replacing the remaining DEFAULT items with NULLs).
4160 : * We don't do this for the original query, because we know that it
4161 : * must be an auto-insert on a view, and so should use the base
4162 : * relation's defaults for any remaining DEFAULT items.
4163 : */
4164 91474 : if (defaults_remaining && product_queries != NIL)
4165 : {
4166 : ListCell *n;
4167 :
4168 : /*
4169 : * Each product query has its own copy of the VALUES RTE at the
4170 : * same index in the rangetable, so we must finalize each one.
4171 : *
4172 : * Note that if the product query is an INSERT ... SELECT, then
4173 : * the VALUES RTE will be at the same index in the SELECT part of
4174 : * the product query rather than the top-level product query
4175 : * itself.
4176 : */
4177 48 : foreach(n, product_queries)
4178 : {
4179 24 : Query *pt = (Query *) lfirst(n);
4180 : RangeTblEntry *values_rte;
4181 :
4182 24 : if (pt->commandType == CMD_INSERT &&
4183 48 : pt->jointree && IsA(pt->jointree, FromExpr) &&
4184 24 : list_length(pt->jointree->fromlist) == 1)
4185 : {
4186 24 : Node *jtnode = (Node *) linitial(pt->jointree->fromlist);
4187 :
4188 24 : if (IsA(jtnode, RangeTblRef))
4189 : {
4190 24 : int rtindex = ((RangeTblRef *) jtnode)->rtindex;
4191 24 : RangeTblEntry *src_rte = rt_fetch(rtindex, pt->rtable);
4192 :
4193 24 : if (src_rte->rtekind == RTE_SUBQUERY &&
4194 6 : src_rte->subquery &&
4195 6 : IsA(src_rte->subquery, Query) &&
4196 6 : src_rte->subquery->commandType == CMD_SELECT)
4197 6 : pt = src_rte->subquery;
4198 : }
4199 : }
4200 :
4201 24 : values_rte = rt_fetch(values_rte_index, pt->rtable);
4202 24 : if (values_rte->rtekind != RTE_VALUES)
4203 0 : elog(ERROR, "failed to find VALUES RTE in product query");
4204 :
4205 24 : rewriteValuesRTEToNulls(pt, values_rte);
4206 : }
4207 : }
4208 :
4209 : /*
4210 : * If there was no unqualified INSTEAD rule, and the target relation
4211 : * is a view without any INSTEAD OF triggers, see if the view can be
4212 : * automatically updated. If so, we perform the necessary query
4213 : * transformation here and add the resulting query to the
4214 : * product_queries list, so that it gets recursively rewritten if
4215 : * necessary. For MERGE, the view must be automatically updatable if
4216 : * any of the merge actions lack a corresponding INSTEAD OF trigger.
4217 : *
4218 : * If the view cannot be automatically updated, we throw an error here
4219 : * which is OK since the query would fail at runtime anyway. Throwing
4220 : * the error here is preferable to the executor check since we have
4221 : * more detailed information available about why the view isn't
4222 : * updatable.
4223 : */
4224 91474 : if (!instead &&
4225 90778 : rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
4226 3926 : !view_has_instead_trigger(rt_entry_relation, event,
4227 : parsetree->mergeActionList))
4228 : {
4229 : /*
4230 : * If there were any qualified INSTEAD rules, don't allow the view
4231 : * to be automatically updated (an unqualified INSTEAD rule or
4232 : * INSTEAD OF trigger is required).
4233 : */
4234 3518 : if (qual_product != NULL)
4235 18 : error_view_not_updatable(rt_entry_relation,
4236 : parsetree->commandType,
4237 : parsetree->mergeActionList,
4238 : gettext_noop("Views with conditional DO INSTEAD rules are not automatically updatable."));
4239 :
4240 : /*
4241 : * Attempt to rewrite the query to automatically update the view.
4242 : * This throws an error if the view can't be automatically
4243 : * updated.
4244 : */
4245 3500 : parsetree = rewriteTargetView(parsetree, rt_entry_relation);
4246 :
4247 : /*
4248 : * At this point product_queries contains any DO ALSO rule
4249 : * actions. Add the rewritten query before or after those. This
4250 : * must match the handling the original query would have gotten
4251 : * below, if we allowed it to be included again.
4252 : */
4253 3230 : if (parsetree->commandType == CMD_INSERT)
4254 1116 : product_queries = lcons(parsetree, product_queries);
4255 : else
4256 2114 : product_queries = lappend(product_queries, parsetree);
4257 :
4258 : /*
4259 : * Set the "instead" flag, as if there had been an unqualified
4260 : * INSTEAD, to prevent the original query from being included a
4261 : * second time below. The transformation will have rewritten any
4262 : * RETURNING list, so we can also set "returning" to forestall
4263 : * throwing an error below.
4264 : */
4265 3230 : instead = true;
4266 3230 : returning = true;
4267 3230 : updatableview = true;
4268 : }
4269 :
4270 : /*
4271 : * If we got any product queries, recursively rewrite them --- but
4272 : * first check for recursion!
4273 : */
4274 91186 : if (product_queries != NIL)
4275 : {
4276 : ListCell *n;
4277 : rewrite_event *rev;
4278 :
4279 5318 : foreach(n, rewrite_events)
4280 : {
4281 960 : rev = (rewrite_event *) lfirst(n);
4282 960 : if (rev->relation == RelationGetRelid(rt_entry_relation) &&
4283 0 : rev->event == event)
4284 0 : ereport(ERROR,
4285 : (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
4286 : errmsg("infinite recursion detected in rules for relation \"%s\"",
4287 : RelationGetRelationName(rt_entry_relation))));
4288 : }
4289 :
4290 4358 : rev = (rewrite_event *) palloc(sizeof(rewrite_event));
4291 4358 : rev->relation = RelationGetRelid(rt_entry_relation);
4292 4358 : rev->event = event;
4293 4358 : rewrite_events = lappend(rewrite_events, rev);
4294 :
4295 8806 : foreach(n, product_queries)
4296 : {
4297 4592 : Query *pt = (Query *) lfirst(n);
4298 : List *newstuff;
4299 :
4300 : /*
4301 : * For an updatable view, pt might be the rewritten version of
4302 : * the original query, in which case we pass on orig_rt_length
4303 : * to finish processing any VALUES RTE it contained.
4304 : *
4305 : * Otherwise, we have a product query created by fireRules().
4306 : * Any VALUES RTEs from the original query have been fully
4307 : * processed, and must be skipped when we recurse.
4308 : */
4309 4592 : newstuff = RewriteQuery(pt, rewrite_events,
4310 : pt == parsetree ?
4311 : orig_rt_length :
4312 : product_orig_rt_length,
4313 : num_ctes_processed);
4314 4448 : rewritten = list_concat(rewritten, newstuff);
4315 : }
4316 :
4317 4214 : rewrite_events = list_delete_last(rewrite_events);
4318 : }
4319 :
4320 : /*
4321 : * If there is an INSTEAD, and the original query has a RETURNING, we
4322 : * have to have found a RETURNING in the rule(s), else fail. (Because
4323 : * DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
4324 : * rules, there's no need to worry whether the substituted RETURNING
4325 : * will actually be executed --- it must be.)
4326 : */
4327 91042 : if ((instead || qual_product != NULL) &&
4328 4094 : parsetree->returningList &&
4329 384 : !returning)
4330 : {
4331 6 : switch (event)
4332 : {
4333 6 : case CMD_INSERT:
4334 6 : ereport(ERROR,
4335 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4336 : errmsg("cannot perform INSERT RETURNING on relation \"%s\"",
4337 : RelationGetRelationName(rt_entry_relation)),
4338 : errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.")));
4339 : break;
4340 0 : case CMD_UPDATE:
4341 0 : ereport(ERROR,
4342 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4343 : errmsg("cannot perform UPDATE RETURNING on relation \"%s\"",
4344 : RelationGetRelationName(rt_entry_relation)),
4345 : errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause.")));
4346 : break;
4347 0 : case CMD_DELETE:
4348 0 : ereport(ERROR,
4349 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4350 : errmsg("cannot perform DELETE RETURNING on relation \"%s\"",
4351 : RelationGetRelationName(rt_entry_relation)),
4352 : errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause.")));
4353 : break;
4354 0 : default:
4355 0 : elog(ERROR, "unrecognized commandType: %d",
4356 : (int) event);
4357 : break;
4358 : }
4359 : }
4360 :
4361 : /*
4362 : * Updatable views are supported by ON CONFLICT, so don't prevent that
4363 : * case from proceeding
4364 : */
4365 91036 : if (parsetree->onConflict &&
4366 1912 : (product_queries != NIL || hasUpdate) &&
4367 180 : !updatableview)
4368 12 : ereport(ERROR,
4369 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4370 : errmsg("INSERT with ON CONFLICT clause cannot be used with table that has INSERT or UPDATE rules")));
4371 :
4372 91024 : table_close(rt_entry_relation, NoLock);
4373 : }
4374 :
4375 : /*
4376 : * For INSERTs, the original query is done first; for UPDATE/DELETE, it is
4377 : * done last. This is needed because update and delete rule actions might
4378 : * not do anything if they are invoked after the update or delete is
4379 : * performed. The command counter increment between the query executions
4380 : * makes the deleted (and maybe the updated) tuples disappear so the scans
4381 : * for them in the rule actions cannot find them.
4382 : *
4383 : * If we found any unqualified INSTEAD, the original query is not done at
4384 : * all, in any form. Otherwise, we add the modified form if qualified
4385 : * INSTEADs were found, else the unmodified form.
4386 : */
4387 447406 : if (!instead)
4388 : {
4389 443642 : if (parsetree->commandType == CMD_INSERT)
4390 : {
4391 67196 : if (qual_product != NULL)
4392 294 : rewritten = lcons(qual_product, rewritten);
4393 : else
4394 66902 : rewritten = lcons(parsetree, rewritten);
4395 : }
4396 : else
4397 : {
4398 376446 : if (qual_product != NULL)
4399 18 : rewritten = lappend(rewritten, qual_product);
4400 : else
4401 376428 : rewritten = lappend(rewritten, parsetree);
4402 : }
4403 : }
4404 :
4405 : /*
4406 : * If the original query has a CTE list, and we generated more than one
4407 : * non-utility result query, we have to fail because we'll have copied the
4408 : * CTE list into each result query. That would break the expectation of
4409 : * single evaluation of CTEs. This could possibly be fixed by
4410 : * restructuring so that a CTE list can be shared across multiple Query
4411 : * and PlannableStatement nodes.
4412 : */
4413 447406 : if (parsetree->cteList != NIL)
4414 : {
4415 2458 : int qcount = 0;
4416 :
4417 4916 : foreach(lc1, rewritten)
4418 : {
4419 2458 : Query *q = (Query *) lfirst(lc1);
4420 :
4421 2458 : if (q->commandType != CMD_UTILITY)
4422 2458 : qcount++;
4423 : }
4424 2458 : if (qcount > 1)
4425 0 : ereport(ERROR,
4426 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
4427 : errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries")));
4428 : }
4429 :
4430 447406 : return rewritten;
4431 : }
4432 :
4433 :
4434 : /*
4435 : * Expand virtual generated columns
4436 : *
4437 : * If the table contains virtual generated columns, build a target list
4438 : * containing the expanded expressions and use ReplaceVarsFromTargetList() to
4439 : * do the replacements.
4440 : *
4441 : * Vars matching rt_index at the current query level are replaced by the
4442 : * virtual generated column expressions from rel, if there are any.
4443 : *
4444 : * The caller must also provide rte, the RTE describing the target relation,
4445 : * in order to handle any whole-row Vars referencing the target, and
4446 : * result_relation, the index of the result relation, if this is part of an
4447 : * INSERT/UPDATE/DELETE/MERGE query.
4448 : */
4449 : static Node *
4450 284 : expand_generated_columns_internal(Node *node, Relation rel, int rt_index,
4451 : RangeTblEntry *rte, int result_relation)
4452 : {
4453 : TupleDesc tupdesc;
4454 :
4455 284 : tupdesc = RelationGetDescr(rel);
4456 284 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
4457 : {
4458 284 : List *tlist = NIL;
4459 :
4460 1010 : for (int i = 0; i < tupdesc->natts; i++)
4461 : {
4462 726 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
4463 :
4464 726 : if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
4465 : {
4466 : Node *defexpr;
4467 : TargetEntry *te;
4468 :
4469 302 : defexpr = build_generation_expression(rel, i + 1);
4470 302 : ChangeVarNodes(defexpr, 1, rt_index, 0);
4471 :
4472 302 : te = makeTargetEntry((Expr *) defexpr, i + 1, 0, false);
4473 302 : tlist = lappend(tlist, te);
4474 : }
4475 : }
4476 :
4477 : Assert(list_length(tlist) > 0);
4478 :
4479 284 : node = ReplaceVarsFromTargetList(node, rt_index, 0, rte, tlist,
4480 : result_relation,
4481 : REPLACEVARS_CHANGE_VARNO, rt_index,
4482 : NULL);
4483 : }
4484 :
4485 284 : return node;
4486 : }
4487 :
4488 : /*
4489 : * Expand virtual generated columns in an expression
4490 : *
4491 : * This is for expressions that are not part of a query, such as default
4492 : * expressions or index predicates. The rt_index is usually 1.
4493 : */
4494 : Node *
4495 12786 : expand_generated_columns_in_expr(Node *node, Relation rel, int rt_index)
4496 : {
4497 12786 : TupleDesc tupdesc = RelationGetDescr(rel);
4498 :
4499 12786 : if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
4500 : {
4501 : RangeTblEntry *rte;
4502 :
4503 284 : rte = makeNode(RangeTblEntry);
4504 : /* eref needs to be set, but the actual name doesn't matter */
4505 284 : rte->eref = makeAlias(RelationGetRelationName(rel), NIL);
4506 284 : rte->rtekind = RTE_RELATION;
4507 284 : rte->relid = RelationGetRelid(rel);
4508 :
4509 284 : node = expand_generated_columns_internal(node, rel, rt_index, rte, 0);
4510 : }
4511 :
4512 12786 : return node;
4513 : }
4514 :
4515 : /*
4516 : * Build the generation expression for the virtual generated column.
4517 : *
4518 : * Error out if there is no generation expression found for the given column.
4519 : */
4520 : Node *
4521 1866 : build_generation_expression(Relation rel, int attrno)
4522 : {
4523 1866 : TupleDesc rd_att = RelationGetDescr(rel);
4524 1866 : Form_pg_attribute att_tup = TupleDescAttr(rd_att, attrno - 1);
4525 : Node *defexpr;
4526 : Oid attcollid;
4527 :
4528 : Assert(rd_att->constr && rd_att->constr->has_generated_virtual);
4529 : Assert(att_tup->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL);
4530 :
4531 1866 : defexpr = build_column_default(rel, attrno);
4532 1866 : if (defexpr == NULL)
4533 0 : elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
4534 : attrno, RelationGetRelationName(rel));
4535 :
4536 : /*
4537 : * If the column definition has a collation and it is different from the
4538 : * collation of the generation expression, put a COLLATE clause around the
4539 : * expression.
4540 : */
4541 1866 : attcollid = att_tup->attcollation;
4542 1866 : if (attcollid && attcollid != exprCollation(defexpr))
4543 : {
4544 12 : CollateExpr *ce = makeNode(CollateExpr);
4545 :
4546 12 : ce->arg = (Expr *) defexpr;
4547 12 : ce->collOid = attcollid;
4548 12 : ce->location = -1;
4549 :
4550 12 : defexpr = (Node *) ce;
4551 : }
4552 :
4553 1866 : return defexpr;
4554 : }
4555 :
4556 :
4557 : /*
4558 : * QueryRewrite -
4559 : * Primary entry point to the query rewriter.
4560 : * Rewrite one query via query rewrite system, possibly returning 0
4561 : * or many queries.
4562 : *
4563 : * NOTE: the parsetree must either have come straight from the parser,
4564 : * or have been scanned by AcquireRewriteLocks to acquire suitable locks.
4565 : */
4566 : List *
4567 443176 : QueryRewrite(Query *parsetree)
4568 : {
4569 443176 : int64 input_query_id = parsetree->queryId;
4570 : List *querylist;
4571 : List *results;
4572 : ListCell *l;
4573 : CmdType origCmdType;
4574 : bool foundOriginalQuery;
4575 : Query *lastInstead;
4576 :
4577 : /*
4578 : * This function is only applied to top-level original queries
4579 : */
4580 : Assert(parsetree->querySource == QSRC_ORIGINAL);
4581 : Assert(parsetree->canSetTag);
4582 :
4583 : /*
4584 : * Step 1
4585 : *
4586 : * Apply all non-SELECT rules possibly getting 0 or many queries
4587 : */
4588 443176 : querylist = RewriteQuery(parsetree, NIL, 0, 0);
4589 :
4590 : /*
4591 : * Step 2
4592 : *
4593 : * Apply all the RIR rules on each query
4594 : *
4595 : * This is also a handy place to mark each query with the original queryId
4596 : */
4597 442600 : results = NIL;
4598 885740 : foreach(l, querylist)
4599 : {
4600 443254 : Query *query = (Query *) lfirst(l);
4601 :
4602 443254 : query = fireRIRrules(query, NIL);
4603 :
4604 443140 : query->queryId = input_query_id;
4605 :
4606 443140 : results = lappend(results, query);
4607 : }
4608 :
4609 : /*
4610 : * Step 3
4611 : *
4612 : * Determine which, if any, of the resulting queries is supposed to set
4613 : * the command-result tag; and update the canSetTag fields accordingly.
4614 : *
4615 : * If the original query is still in the list, it sets the command tag.
4616 : * Otherwise, the last INSTEAD query of the same kind as the original is
4617 : * allowed to set the tag. (Note these rules can leave us with no query
4618 : * setting the tag. The tcop code has to cope with this by setting up a
4619 : * default tag based on the original un-rewritten query.)
4620 : *
4621 : * The Asserts verify that at most one query in the result list is marked
4622 : * canSetTag. If we aren't checking asserts, we can fall out of the loop
4623 : * as soon as we find the original query.
4624 : */
4625 442486 : origCmdType = parsetree->commandType;
4626 442486 : foundOriginalQuery = false;
4627 442486 : lastInstead = NULL;
4628 :
4629 443332 : foreach(l, results)
4630 : {
4631 442684 : Query *query = (Query *) lfirst(l);
4632 :
4633 442684 : if (query->querySource == QSRC_ORIGINAL)
4634 : {
4635 : Assert(query->canSetTag);
4636 : Assert(!foundOriginalQuery);
4637 441838 : foundOriginalQuery = true;
4638 : #ifndef USE_ASSERT_CHECKING
4639 441838 : break;
4640 : #endif
4641 : }
4642 : else
4643 : {
4644 : Assert(!query->canSetTag);
4645 846 : if (query->commandType == origCmdType &&
4646 630 : (query->querySource == QSRC_INSTEAD_RULE ||
4647 108 : query->querySource == QSRC_QUAL_INSTEAD_RULE))
4648 570 : lastInstead = query;
4649 : }
4650 : }
4651 :
4652 442486 : if (!foundOriginalQuery && lastInstead != NULL)
4653 546 : lastInstead->canSetTag = true;
4654 :
4655 442486 : return results;
4656 : }
|
