Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * cluster.c
4 : * CLUSTER a table on an index. This is now also used for VACUUM FULL.
5 : *
6 : * There is hardly anything left of Paul Brown's original implementation...
7 : *
8 : *
9 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
10 : * Portions Copyright (c) 1994-5, Regents of the University of California
11 : *
12 : *
13 : * IDENTIFICATION
14 : * src/backend/commands/cluster.c
15 : *
16 : *-------------------------------------------------------------------------
17 : */
18 : #include "postgres.h"
19 :
20 : #include "access/amapi.h"
21 : #include "access/heapam.h"
22 : #include "access/multixact.h"
23 : #include "access/relscan.h"
24 : #include "access/tableam.h"
25 : #include "access/toast_internals.h"
26 : #include "access/transam.h"
27 : #include "access/xact.h"
28 : #include "catalog/catalog.h"
29 : #include "catalog/dependency.h"
30 : #include "catalog/heap.h"
31 : #include "catalog/index.h"
32 : #include "catalog/namespace.h"
33 : #include "catalog/objectaccess.h"
34 : #include "catalog/pg_am.h"
35 : #include "catalog/pg_inherits.h"
36 : #include "catalog/toasting.h"
37 : #include "commands/cluster.h"
38 : #include "commands/defrem.h"
39 : #include "commands/progress.h"
40 : #include "commands/tablecmds.h"
41 : #include "commands/vacuum.h"
42 : #include "miscadmin.h"
43 : #include "optimizer/optimizer.h"
44 : #include "pgstat.h"
45 : #include "storage/bufmgr.h"
46 : #include "storage/lmgr.h"
47 : #include "storage/predicate.h"
48 : #include "utils/acl.h"
49 : #include "utils/fmgroids.h"
50 : #include "utils/guc.h"
51 : #include "utils/inval.h"
52 : #include "utils/lsyscache.h"
53 : #include "utils/memutils.h"
54 : #include "utils/pg_rusage.h"
55 : #include "utils/relmapper.h"
56 : #include "utils/snapmgr.h"
57 : #include "utils/syscache.h"
58 :
59 : /*
60 : * This struct is used to pass around the information on tables to be
61 : * clustered. We need this so we can make a list of them when invoked without
62 : * a specific table/index pair.
63 : */
64 : typedef struct
65 : {
66 : Oid tableOid;
67 : Oid indexOid;
68 : } RelToCluster;
69 :
70 :
71 : static void cluster_multiple_rels(List *rtcs, ClusterParams *params);
72 : static void rebuild_relation(Relation OldHeap, Relation index, bool verbose);
73 : static void copy_table_data(Relation NewHeap, Relation OldHeap, Relation OldIndex,
74 : bool verbose, bool *pSwapToastByContent,
75 : TransactionId *pFreezeXid, MultiXactId *pCutoffMulti);
76 : static List *get_tables_to_cluster(MemoryContext cluster_context);
77 : static List *get_tables_to_cluster_partitioned(MemoryContext cluster_context,
78 : Oid indexOid);
79 : static bool cluster_is_permitted_for_relation(Oid relid, Oid userid);
80 :
81 :
82 : /*---------------------------------------------------------------------------
83 : * This cluster code allows for clustering multiple tables at once. Because
84 : * of this, we cannot just run everything on a single transaction, or we
85 : * would be forced to acquire exclusive locks on all the tables being
86 : * clustered, simultaneously --- very likely leading to deadlock.
87 : *
88 : * To solve this we follow a similar strategy to VACUUM code,
89 : * clustering each relation in a separate transaction. For this to work,
90 : * we need to:
91 : * - provide a separate memory context so that we can pass information in
92 : * a way that survives across transactions
93 : * - start a new transaction every time a new relation is clustered
94 : * - check for validity of the information on to-be-clustered relations,
95 : * as someone might have deleted a relation behind our back, or
96 : * clustered one on a different index
97 : * - end the transaction
98 : *
99 : * The single-relation case does not have any such overhead.
100 : *
101 : * We also allow a relation to be specified without index. In that case,
102 : * the indisclustered bit will be looked up, and an ERROR will be thrown
103 : * if there is no index with the bit set.
104 : *---------------------------------------------------------------------------
105 : */
106 : void
107 238 : cluster(ParseState *pstate, ClusterStmt *stmt, bool isTopLevel)
108 : {
109 : ListCell *lc;
110 238 : ClusterParams params = {0};
111 238 : bool verbose = false;
112 238 : Relation rel = NULL;
113 238 : Oid indexOid = InvalidOid;
114 : MemoryContext cluster_context;
115 : List *rtcs;
116 :
117 : /* Parse option list */
118 252 : foreach(lc, stmt->params)
119 : {
120 14 : DefElem *opt = (DefElem *) lfirst(lc);
121 :
122 14 : if (strcmp(opt->defname, "verbose") == 0)
123 14 : verbose = defGetBoolean(opt);
124 : else
125 0 : ereport(ERROR,
126 : (errcode(ERRCODE_SYNTAX_ERROR),
127 : errmsg("unrecognized CLUSTER option \"%s\"",
128 : opt->defname),
129 : parser_errposition(pstate, opt->location)));
130 : }
131 :
132 238 : params.options = (verbose ? CLUOPT_VERBOSE : 0);
133 :
134 238 : if (stmt->relation != NULL)
135 : {
136 : /* This is the single-relation case. */
137 : Oid tableOid;
138 :
139 : /*
140 : * Find, lock, and check permissions on the table. We obtain
141 : * AccessExclusiveLock right away to avoid lock-upgrade hazard in the
142 : * single-transaction case.
143 : */
144 208 : tableOid = RangeVarGetRelidExtended(stmt->relation,
145 : AccessExclusiveLock,
146 : 0,
147 : RangeVarCallbackMaintainsTable,
148 : NULL);
149 196 : rel = table_open(tableOid, NoLock);
150 :
151 : /*
152 : * Reject clustering a remote temp table ... their local buffer
153 : * manager is not going to cope.
154 : */
155 196 : if (RELATION_IS_OTHER_TEMP(rel))
156 0 : ereport(ERROR,
157 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
158 : errmsg("cannot cluster temporary tables of other sessions")));
159 :
160 196 : if (stmt->indexname == NULL)
161 : {
162 : ListCell *index;
163 :
164 : /* We need to find the index that has indisclustered set. */
165 46 : foreach(index, RelationGetIndexList(rel))
166 : {
167 34 : indexOid = lfirst_oid(index);
168 34 : if (get_index_isclustered(indexOid))
169 22 : break;
170 12 : indexOid = InvalidOid;
171 : }
172 :
173 34 : if (!OidIsValid(indexOid))
174 12 : ereport(ERROR,
175 : (errcode(ERRCODE_UNDEFINED_OBJECT),
176 : errmsg("there is no previously clustered index for table \"%s\"",
177 : stmt->relation->relname)));
178 : }
179 : else
180 : {
181 : /*
182 : * The index is expected to be in the same namespace as the
183 : * relation.
184 : */
185 162 : indexOid = get_relname_relid(stmt->indexname,
186 162 : rel->rd_rel->relnamespace);
187 162 : if (!OidIsValid(indexOid))
188 0 : ereport(ERROR,
189 : (errcode(ERRCODE_UNDEFINED_OBJECT),
190 : errmsg("index \"%s\" for table \"%s\" does not exist",
191 : stmt->indexname, stmt->relation->relname)));
192 : }
193 :
194 : /* For non-partitioned tables, do what we came here to do. */
195 184 : if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
196 : {
197 158 : cluster_rel(rel, indexOid, ¶ms);
198 : /* cluster_rel closes the relation, but keeps lock */
199 :
200 158 : return;
201 : }
202 : }
203 :
204 : /*
205 : * By here, we know we are in a multi-table situation. In order to avoid
206 : * holding locks for too long, we want to process each table in its own
207 : * transaction. This forces us to disallow running inside a user
208 : * transaction block.
209 : */
210 56 : PreventInTransactionBlock(isTopLevel, "CLUSTER");
211 :
212 : /* Also, we need a memory context to hold our list of relations */
213 56 : cluster_context = AllocSetContextCreate(PortalContext,
214 : "Cluster",
215 : ALLOCSET_DEFAULT_SIZES);
216 :
217 : /*
218 : * Either we're processing a partitioned table, or we were not given any
219 : * table name at all. In either case, obtain a list of relations to
220 : * process.
221 : *
222 : * In the former case, an index name must have been given, so we don't
223 : * need to recheck its "indisclustered" bit, but we have to check that it
224 : * is an index that we can cluster on. In the latter case, we set the
225 : * option bit to have indisclustered verified.
226 : *
227 : * Rechecking the relation itself is necessary here in all cases.
228 : */
229 56 : params.options |= CLUOPT_RECHECK;
230 56 : if (rel != NULL)
231 : {
232 : Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
233 26 : check_index_is_clusterable(rel, indexOid, AccessShareLock);
234 20 : rtcs = get_tables_to_cluster_partitioned(cluster_context, indexOid);
235 :
236 : /* close relation, releasing lock on parent table */
237 20 : table_close(rel, AccessExclusiveLock);
238 : }
239 : else
240 : {
241 30 : rtcs = get_tables_to_cluster(cluster_context);
242 30 : params.options |= CLUOPT_RECHECK_ISCLUSTERED;
243 : }
244 :
245 : /* Do the job. */
246 50 : cluster_multiple_rels(rtcs, ¶ms);
247 :
248 : /* Start a new transaction for the cleanup work. */
249 50 : StartTransactionCommand();
250 :
251 : /* Clean up working storage */
252 50 : MemoryContextDelete(cluster_context);
253 : }
254 :
255 : /*
256 : * Given a list of relations to cluster, process each of them in a separate
257 : * transaction.
258 : *
259 : * We expect to be in a transaction at start, but there isn't one when we
260 : * return.
261 : */
262 : static void
263 50 : cluster_multiple_rels(List *rtcs, ClusterParams *params)
264 : {
265 : ListCell *lc;
266 :
267 : /* Commit to get out of starting transaction */
268 50 : PopActiveSnapshot();
269 50 : CommitTransactionCommand();
270 :
271 : /* Cluster the tables, each in a separate transaction */
272 80 : foreach(lc, rtcs)
273 : {
274 30 : RelToCluster *rtc = (RelToCluster *) lfirst(lc);
275 : Relation rel;
276 :
277 : /* Start a new transaction for each relation. */
278 30 : StartTransactionCommand();
279 :
280 : /* functions in indexes may want a snapshot set */
281 30 : PushActiveSnapshot(GetTransactionSnapshot());
282 :
283 30 : rel = table_open(rtc->tableOid, AccessExclusiveLock);
284 :
285 : /* Process this table */
286 30 : cluster_rel(rel, rtc->indexOid, params);
287 : /* cluster_rel closes the relation, but keeps lock */
288 :
289 30 : PopActiveSnapshot();
290 30 : CommitTransactionCommand();
291 : }
292 50 : }
293 :
294 : /*
295 : * cluster_rel
296 : *
297 : * This clusters the table by creating a new, clustered table and
298 : * swapping the relfilenumbers of the new table and the old table, so
299 : * the OID of the original table is preserved. Thus we do not lose
300 : * GRANT, inheritance nor references to this table.
301 : *
302 : * Indexes are rebuilt too, via REINDEX. Since we are effectively bulk-loading
303 : * the new table, it's better to create the indexes afterwards than to fill
304 : * them incrementally while we load the table.
305 : *
306 : * If indexOid is InvalidOid, the table will be rewritten in physical order
307 : * instead of index order. This is the new implementation of VACUUM FULL,
308 : * and error messages should refer to the operation as VACUUM not CLUSTER.
309 : */
310 : void
311 562 : cluster_rel(Relation OldHeap, Oid indexOid, ClusterParams *params)
312 : {
313 562 : Oid tableOid = RelationGetRelid(OldHeap);
314 : Oid save_userid;
315 : int save_sec_context;
316 : int save_nestlevel;
317 562 : bool verbose = ((params->options & CLUOPT_VERBOSE) != 0);
318 562 : bool recheck = ((params->options & CLUOPT_RECHECK) != 0);
319 : Relation index;
320 :
321 : Assert(CheckRelationLockedByMe(OldHeap, AccessExclusiveLock, false));
322 :
323 : /* Check for user-requested abort. */
324 562 : CHECK_FOR_INTERRUPTS();
325 :
326 562 : pgstat_progress_start_command(PROGRESS_COMMAND_CLUSTER, tableOid);
327 562 : if (OidIsValid(indexOid))
328 188 : pgstat_progress_update_param(PROGRESS_CLUSTER_COMMAND,
329 : PROGRESS_CLUSTER_COMMAND_CLUSTER);
330 : else
331 374 : pgstat_progress_update_param(PROGRESS_CLUSTER_COMMAND,
332 : PROGRESS_CLUSTER_COMMAND_VACUUM_FULL);
333 :
334 : /*
335 : * Switch to the table owner's userid, so that any index functions are run
336 : * as that user. Also lock down security-restricted operations and
337 : * arrange to make GUC variable changes local to this command.
338 : */
339 562 : GetUserIdAndSecContext(&save_userid, &save_sec_context);
340 562 : SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
341 : save_sec_context | SECURITY_RESTRICTED_OPERATION);
342 562 : save_nestlevel = NewGUCNestLevel();
343 562 : RestrictSearchPath();
344 :
345 : /*
346 : * Since we may open a new transaction for each relation, we have to check
347 : * that the relation still is what we think it is.
348 : *
349 : * If this is a single-transaction CLUSTER, we can skip these tests. We
350 : * *must* skip the one on indisclustered since it would reject an attempt
351 : * to cluster a not-previously-clustered index.
352 : */
353 562 : if (recheck)
354 : {
355 : /* Check that the user still has privileges for the relation */
356 30 : if (!cluster_is_permitted_for_relation(tableOid, save_userid))
357 : {
358 0 : relation_close(OldHeap, AccessExclusiveLock);
359 0 : goto out;
360 : }
361 :
362 : /*
363 : * Silently skip a temp table for a remote session. Only doing this
364 : * check in the "recheck" case is appropriate (which currently means
365 : * somebody is executing a database-wide CLUSTER or on a partitioned
366 : * table), because there is another check in cluster() which will stop
367 : * any attempt to cluster remote temp tables by name. There is
368 : * another check in cluster_rel which is redundant, but we leave it
369 : * for extra safety.
370 : */
371 30 : if (RELATION_IS_OTHER_TEMP(OldHeap))
372 : {
373 0 : relation_close(OldHeap, AccessExclusiveLock);
374 0 : goto out;
375 : }
376 :
377 30 : if (OidIsValid(indexOid))
378 : {
379 : /*
380 : * Check that the index still exists
381 : */
382 30 : if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(indexOid)))
383 : {
384 0 : relation_close(OldHeap, AccessExclusiveLock);
385 0 : goto out;
386 : }
387 :
388 : /*
389 : * Check that the index is still the one with indisclustered set,
390 : * if needed.
391 : */
392 30 : if ((params->options & CLUOPT_RECHECK_ISCLUSTERED) != 0 &&
393 6 : !get_index_isclustered(indexOid))
394 : {
395 0 : relation_close(OldHeap, AccessExclusiveLock);
396 0 : goto out;
397 : }
398 : }
399 : }
400 :
401 : /*
402 : * We allow VACUUM FULL, but not CLUSTER, on shared catalogs. CLUSTER
403 : * would work in most respects, but the index would only get marked as
404 : * indisclustered in the current database, leading to unexpected behavior
405 : * if CLUSTER were later invoked in another database.
406 : */
407 562 : if (OidIsValid(indexOid) && OldHeap->rd_rel->relisshared)
408 0 : ereport(ERROR,
409 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
410 : errmsg("cannot cluster a shared catalog")));
411 :
412 : /*
413 : * Don't process temp tables of other backends ... their local buffer
414 : * manager is not going to cope.
415 : */
416 562 : if (RELATION_IS_OTHER_TEMP(OldHeap))
417 : {
418 0 : if (OidIsValid(indexOid))
419 0 : ereport(ERROR,
420 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
421 : errmsg("cannot cluster temporary tables of other sessions")));
422 : else
423 0 : ereport(ERROR,
424 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
425 : errmsg("cannot vacuum temporary tables of other sessions")));
426 : }
427 :
428 : /*
429 : * Also check for active uses of the relation in the current transaction,
430 : * including open scans and pending AFTER trigger events.
431 : */
432 562 : CheckTableNotInUse(OldHeap, OidIsValid(indexOid) ? "CLUSTER" : "VACUUM");
433 :
434 : /* Check heap and index are valid to cluster on */
435 562 : if (OidIsValid(indexOid))
436 : {
437 : /* verify the index is good and lock it */
438 188 : check_index_is_clusterable(OldHeap, indexOid, AccessExclusiveLock);
439 : /* also open it */
440 188 : index = index_open(indexOid, NoLock);
441 : }
442 : else
443 374 : index = NULL;
444 :
445 : /*
446 : * Quietly ignore the request if this is a materialized view which has not
447 : * been populated from its query. No harm is done because there is no data
448 : * to deal with, and we don't want to throw an error if this is part of a
449 : * multi-relation request -- for example, CLUSTER was run on the entire
450 : * database.
451 : */
452 562 : if (OldHeap->rd_rel->relkind == RELKIND_MATVIEW &&
453 0 : !RelationIsPopulated(OldHeap))
454 : {
455 0 : relation_close(OldHeap, AccessExclusiveLock);
456 0 : goto out;
457 : }
458 :
459 : Assert(OldHeap->rd_rel->relkind == RELKIND_RELATION ||
460 : OldHeap->rd_rel->relkind == RELKIND_MATVIEW ||
461 : OldHeap->rd_rel->relkind == RELKIND_TOASTVALUE);
462 :
463 : /*
464 : * All predicate locks on the tuples or pages are about to be made
465 : * invalid, because we move tuples around. Promote them to relation
466 : * locks. Predicate locks on indexes will be promoted when they are
467 : * reindexed.
468 : */
469 562 : TransferPredicateLocksToHeapRelation(OldHeap);
470 :
471 : /* rebuild_relation does all the dirty work */
472 562 : rebuild_relation(OldHeap, index, verbose);
473 : /* rebuild_relation closes OldHeap, and index if valid */
474 :
475 556 : out:
476 : /* Roll back any GUC changes executed by index functions */
477 556 : AtEOXact_GUC(false, save_nestlevel);
478 :
479 : /* Restore userid and security context */
480 556 : SetUserIdAndSecContext(save_userid, save_sec_context);
481 :
482 556 : pgstat_progress_end_command();
483 556 : }
484 :
485 : /*
486 : * Verify that the specified heap and index are valid to cluster on
487 : *
488 : * Side effect: obtains lock on the index. The caller may
489 : * in some cases already have AccessExclusiveLock on the table, but
490 : * not in all cases so we can't rely on the table-level lock for
491 : * protection here.
492 : */
493 : void
494 278 : check_index_is_clusterable(Relation OldHeap, Oid indexOid, LOCKMODE lockmode)
495 : {
496 : Relation OldIndex;
497 :
498 278 : OldIndex = index_open(indexOid, lockmode);
499 :
500 : /*
501 : * Check that index is in fact an index on the given relation
502 : */
503 278 : if (OldIndex->rd_index == NULL ||
504 278 : OldIndex->rd_index->indrelid != RelationGetRelid(OldHeap))
505 0 : ereport(ERROR,
506 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
507 : errmsg("\"%s\" is not an index for table \"%s\"",
508 : RelationGetRelationName(OldIndex),
509 : RelationGetRelationName(OldHeap))));
510 :
511 : /* Index AM must allow clustering */
512 278 : if (!OldIndex->rd_indam->amclusterable)
513 0 : ereport(ERROR,
514 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
515 : errmsg("cannot cluster on index \"%s\" because access method does not support clustering",
516 : RelationGetRelationName(OldIndex))));
517 :
518 : /*
519 : * Disallow clustering on incomplete indexes (those that might not index
520 : * every row of the relation). We could relax this by making a separate
521 : * seqscan pass over the table to copy the missing rows, but that seems
522 : * expensive and tedious.
523 : */
524 278 : if (!heap_attisnull(OldIndex->rd_indextuple, Anum_pg_index_indpred, NULL))
525 0 : ereport(ERROR,
526 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
527 : errmsg("cannot cluster on partial index \"%s\"",
528 : RelationGetRelationName(OldIndex))));
529 :
530 : /*
531 : * Disallow if index is left over from a failed CREATE INDEX CONCURRENTLY;
532 : * it might well not contain entries for every heap row, or might not even
533 : * be internally consistent. (But note that we don't check indcheckxmin;
534 : * the worst consequence of following broken HOT chains would be that we
535 : * might put recently-dead tuples out-of-order in the new table, and there
536 : * is little harm in that.)
537 : */
538 278 : if (!OldIndex->rd_index->indisvalid)
539 6 : ereport(ERROR,
540 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
541 : errmsg("cannot cluster on invalid index \"%s\"",
542 : RelationGetRelationName(OldIndex))));
543 :
544 : /* Drop relcache refcnt on OldIndex, but keep lock */
545 272 : index_close(OldIndex, NoLock);
546 272 : }
547 :
548 : /*
549 : * mark_index_clustered: mark the specified index as the one clustered on
550 : *
551 : * With indexOid == InvalidOid, will mark all indexes of rel not-clustered.
552 : */
553 : void
554 270 : mark_index_clustered(Relation rel, Oid indexOid, bool is_internal)
555 : {
556 : HeapTuple indexTuple;
557 : Form_pg_index indexForm;
558 : Relation pg_index;
559 : ListCell *index;
560 :
561 : /* Disallow applying to a partitioned table */
562 270 : if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
563 12 : ereport(ERROR,
564 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
565 : errmsg("cannot mark index clustered in partitioned table")));
566 :
567 : /*
568 : * If the index is already marked clustered, no need to do anything.
569 : */
570 258 : if (OidIsValid(indexOid))
571 : {
572 246 : if (get_index_isclustered(indexOid))
573 40 : return;
574 : }
575 :
576 : /*
577 : * Check each index of the relation and set/clear the bit as needed.
578 : */
579 218 : pg_index = table_open(IndexRelationId, RowExclusiveLock);
580 :
581 642 : foreach(index, RelationGetIndexList(rel))
582 : {
583 424 : Oid thisIndexOid = lfirst_oid(index);
584 :
585 424 : indexTuple = SearchSysCacheCopy1(INDEXRELID,
586 : ObjectIdGetDatum(thisIndexOid));
587 424 : if (!HeapTupleIsValid(indexTuple))
588 0 : elog(ERROR, "cache lookup failed for index %u", thisIndexOid);
589 424 : indexForm = (Form_pg_index) GETSTRUCT(indexTuple);
590 :
591 : /*
592 : * Unset the bit if set. We know it's wrong because we checked this
593 : * earlier.
594 : */
595 424 : if (indexForm->indisclustered)
596 : {
597 30 : indexForm->indisclustered = false;
598 30 : CatalogTupleUpdate(pg_index, &indexTuple->t_self, indexTuple);
599 : }
600 394 : else if (thisIndexOid == indexOid)
601 : {
602 : /* this was checked earlier, but let's be real sure */
603 206 : if (!indexForm->indisvalid)
604 0 : elog(ERROR, "cannot cluster on invalid index %u", indexOid);
605 206 : indexForm->indisclustered = true;
606 206 : CatalogTupleUpdate(pg_index, &indexTuple->t_self, indexTuple);
607 : }
608 :
609 424 : InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0,
610 : InvalidOid, is_internal);
611 :
612 424 : heap_freetuple(indexTuple);
613 : }
614 :
615 218 : table_close(pg_index, RowExclusiveLock);
616 : }
617 :
618 : /*
619 : * rebuild_relation: rebuild an existing relation in index or physical order
620 : *
621 : * OldHeap: table to rebuild.
622 : * index: index to cluster by, or NULL to rewrite in physical order.
623 : *
624 : * On entry, heap and index (if one is given) must be open, and
625 : * AccessExclusiveLock held on them.
626 : * On exit, they are closed, but locks on them are not released.
627 : */
628 : static void
629 562 : rebuild_relation(Relation OldHeap, Relation index, bool verbose)
630 : {
631 562 : Oid tableOid = RelationGetRelid(OldHeap);
632 562 : Oid accessMethod = OldHeap->rd_rel->relam;
633 562 : Oid tableSpace = OldHeap->rd_rel->reltablespace;
634 : Oid OIDNewHeap;
635 : Relation NewHeap;
636 : char relpersistence;
637 : bool is_system_catalog;
638 : bool swap_toast_by_content;
639 : TransactionId frozenXid;
640 : MultiXactId cutoffMulti;
641 :
642 : Assert(CheckRelationLockedByMe(OldHeap, AccessExclusiveLock, false) &&
643 : (index == NULL || CheckRelationLockedByMe(index, AccessExclusiveLock, false)));
644 :
645 562 : if (index)
646 : /* Mark the correct index as clustered */
647 188 : mark_index_clustered(OldHeap, RelationGetRelid(index), true);
648 :
649 : /* Remember info about rel before closing OldHeap */
650 562 : relpersistence = OldHeap->rd_rel->relpersistence;
651 562 : is_system_catalog = IsSystemRelation(OldHeap);
652 :
653 : /*
654 : * Create the transient table that will receive the re-ordered data.
655 : *
656 : * OldHeap is already locked, so no need to lock it again. make_new_heap
657 : * obtains AccessExclusiveLock on the new heap and its toast table.
658 : */
659 562 : OIDNewHeap = make_new_heap(tableOid, tableSpace,
660 : accessMethod,
661 : relpersistence,
662 : NoLock);
663 : Assert(CheckRelationOidLockedByMe(OIDNewHeap, AccessExclusiveLock, false));
664 562 : NewHeap = table_open(OIDNewHeap, NoLock);
665 :
666 : /* Copy the heap data into the new table in the desired order */
667 562 : copy_table_data(NewHeap, OldHeap, index, verbose,
668 : &swap_toast_by_content, &frozenXid, &cutoffMulti);
669 :
670 :
671 : /* Close relcache entries, but keep lock until transaction commit */
672 562 : table_close(OldHeap, NoLock);
673 562 : if (index)
674 188 : index_close(index, NoLock);
675 :
676 : /*
677 : * Close the new relation so it can be dropped as soon as the storage is
678 : * swapped. The relation is not visible to others, so no need to unlock it
679 : * explicitly.
680 : */
681 562 : table_close(NewHeap, NoLock);
682 :
683 : /*
684 : * Swap the physical files of the target and transient tables, then
685 : * rebuild the target's indexes and throw away the transient table.
686 : */
687 562 : finish_heap_swap(tableOid, OIDNewHeap, is_system_catalog,
688 : swap_toast_by_content, false, true,
689 : frozenXid, cutoffMulti,
690 : relpersistence);
691 556 : }
692 :
693 :
694 : /*
695 : * Create the transient table that will be filled with new data during
696 : * CLUSTER, ALTER TABLE, and similar operations. The transient table
697 : * duplicates the logical structure of the OldHeap; but will have the
698 : * specified physical storage properties NewTableSpace, NewAccessMethod, and
699 : * relpersistence.
700 : *
701 : * After this, the caller should load the new heap with transferred/modified
702 : * data, then call finish_heap_swap to complete the operation.
703 : */
704 : Oid
705 2166 : make_new_heap(Oid OIDOldHeap, Oid NewTableSpace, Oid NewAccessMethod,
706 : char relpersistence, LOCKMODE lockmode)
707 : {
708 : TupleDesc OldHeapDesc;
709 : char NewHeapName[NAMEDATALEN];
710 : Oid OIDNewHeap;
711 : Oid toastid;
712 : Relation OldHeap;
713 : HeapTuple tuple;
714 : Datum reloptions;
715 : bool isNull;
716 : Oid namespaceid;
717 :
718 2166 : OldHeap = table_open(OIDOldHeap, lockmode);
719 2166 : OldHeapDesc = RelationGetDescr(OldHeap);
720 :
721 : /*
722 : * Note that the NewHeap will not receive any of the defaults or
723 : * constraints associated with the OldHeap; we don't need 'em, and there's
724 : * no reason to spend cycles inserting them into the catalogs only to
725 : * delete them.
726 : */
727 :
728 : /*
729 : * But we do want to use reloptions of the old heap for new heap.
730 : */
731 2166 : tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(OIDOldHeap));
732 2166 : if (!HeapTupleIsValid(tuple))
733 0 : elog(ERROR, "cache lookup failed for relation %u", OIDOldHeap);
734 2166 : reloptions = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
735 : &isNull);
736 2166 : if (isNull)
737 2128 : reloptions = (Datum) 0;
738 :
739 2166 : if (relpersistence == RELPERSISTENCE_TEMP)
740 152 : namespaceid = LookupCreationNamespace("pg_temp");
741 : else
742 2014 : namespaceid = RelationGetNamespace(OldHeap);
743 :
744 : /*
745 : * Create the new heap, using a temporary name in the same namespace as
746 : * the existing table. NOTE: there is some risk of collision with user
747 : * relnames. Working around this seems more trouble than it's worth; in
748 : * particular, we can't create the new heap in a different namespace from
749 : * the old, or we will have problems with the TEMP status of temp tables.
750 : *
751 : * Note: the new heap is not a shared relation, even if we are rebuilding
752 : * a shared rel. However, we do make the new heap mapped if the source is
753 : * mapped. This simplifies swap_relation_files, and is absolutely
754 : * necessary for rebuilding pg_class, for reasons explained there.
755 : */
756 2166 : snprintf(NewHeapName, sizeof(NewHeapName), "pg_temp_%u", OIDOldHeap);
757 :
758 2166 : OIDNewHeap = heap_create_with_catalog(NewHeapName,
759 : namespaceid,
760 : NewTableSpace,
761 : InvalidOid,
762 : InvalidOid,
763 : InvalidOid,
764 2166 : OldHeap->rd_rel->relowner,
765 : NewAccessMethod,
766 : OldHeapDesc,
767 : NIL,
768 : RELKIND_RELATION,
769 : relpersistence,
770 : false,
771 2166 : RelationIsMapped(OldHeap),
772 : ONCOMMIT_NOOP,
773 : reloptions,
774 : false,
775 : true,
776 : true,
777 : OIDOldHeap,
778 : NULL);
779 : Assert(OIDNewHeap != InvalidOid);
780 :
781 2166 : ReleaseSysCache(tuple);
782 :
783 : /*
784 : * Advance command counter so that the newly-created relation's catalog
785 : * tuples will be visible to table_open.
786 : */
787 2166 : CommandCounterIncrement();
788 :
789 : /*
790 : * If necessary, create a TOAST table for the new relation.
791 : *
792 : * If the relation doesn't have a TOAST table already, we can't need one
793 : * for the new relation. The other way around is possible though: if some
794 : * wide columns have been dropped, NewHeapCreateToastTable can decide that
795 : * no TOAST table is needed for the new table.
796 : *
797 : * Note that NewHeapCreateToastTable ends with CommandCounterIncrement, so
798 : * that the TOAST table will be visible for insertion.
799 : */
800 2166 : toastid = OldHeap->rd_rel->reltoastrelid;
801 2166 : if (OidIsValid(toastid))
802 : {
803 : /* keep the existing toast table's reloptions, if any */
804 868 : tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid));
805 868 : if (!HeapTupleIsValid(tuple))
806 0 : elog(ERROR, "cache lookup failed for relation %u", toastid);
807 868 : reloptions = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
808 : &isNull);
809 868 : if (isNull)
810 868 : reloptions = (Datum) 0;
811 :
812 868 : NewHeapCreateToastTable(OIDNewHeap, reloptions, lockmode, toastid);
813 :
814 868 : ReleaseSysCache(tuple);
815 : }
816 :
817 2166 : table_close(OldHeap, NoLock);
818 :
819 2166 : return OIDNewHeap;
820 : }
821 :
822 : /*
823 : * Do the physical copying of table data.
824 : *
825 : * There are three output parameters:
826 : * *pSwapToastByContent is set true if toast tables must be swapped by content.
827 : * *pFreezeXid receives the TransactionId used as freeze cutoff point.
828 : * *pCutoffMulti receives the MultiXactId used as a cutoff point.
829 : */
830 : static void
831 562 : copy_table_data(Relation NewHeap, Relation OldHeap, Relation OldIndex, bool verbose,
832 : bool *pSwapToastByContent, TransactionId *pFreezeXid,
833 : MultiXactId *pCutoffMulti)
834 : {
835 : Relation relRelation;
836 : HeapTuple reltup;
837 : Form_pg_class relform;
838 : TupleDesc oldTupDesc PG_USED_FOR_ASSERTS_ONLY;
839 : TupleDesc newTupDesc PG_USED_FOR_ASSERTS_ONLY;
840 : VacuumParams params;
841 : struct VacuumCutoffs cutoffs;
842 : bool use_sort;
843 562 : double num_tuples = 0,
844 562 : tups_vacuumed = 0,
845 562 : tups_recently_dead = 0;
846 : BlockNumber num_pages;
847 562 : int elevel = verbose ? INFO : DEBUG2;
848 : PGRUsage ru0;
849 : char *nspname;
850 :
851 562 : pg_rusage_init(&ru0);
852 :
853 : /* Store a copy of the namespace name for logging purposes */
854 562 : nspname = get_namespace_name(RelationGetNamespace(OldHeap));
855 :
856 : /*
857 : * Their tuple descriptors should be exactly alike, but here we only need
858 : * assume that they have the same number of columns.
859 : */
860 562 : oldTupDesc = RelationGetDescr(OldHeap);
861 562 : newTupDesc = RelationGetDescr(NewHeap);
862 : Assert(newTupDesc->natts == oldTupDesc->natts);
863 :
864 : /*
865 : * If the OldHeap has a toast table, get lock on the toast table to keep
866 : * it from being vacuumed. This is needed because autovacuum processes
867 : * toast tables independently of their main tables, with no lock on the
868 : * latter. If an autovacuum were to start on the toast table after we
869 : * compute our OldestXmin below, it would use a later OldestXmin, and then
870 : * possibly remove as DEAD toast tuples belonging to main tuples we think
871 : * are only RECENTLY_DEAD. Then we'd fail while trying to copy those
872 : * tuples.
873 : *
874 : * We don't need to open the toast relation here, just lock it. The lock
875 : * will be held till end of transaction.
876 : */
877 562 : if (OldHeap->rd_rel->reltoastrelid)
878 184 : LockRelationOid(OldHeap->rd_rel->reltoastrelid, AccessExclusiveLock);
879 :
880 : /*
881 : * If both tables have TOAST tables, perform toast swap by content. It is
882 : * possible that the old table has a toast table but the new one doesn't,
883 : * if toastable columns have been dropped. In that case we have to do
884 : * swap by links. This is okay because swap by content is only essential
885 : * for system catalogs, and we don't support schema changes for them.
886 : */
887 562 : if (OldHeap->rd_rel->reltoastrelid && NewHeap->rd_rel->reltoastrelid)
888 : {
889 184 : *pSwapToastByContent = true;
890 :
891 : /*
892 : * When doing swap by content, any toast pointers written into NewHeap
893 : * must use the old toast table's OID, because that's where the toast
894 : * data will eventually be found. Set this up by setting rd_toastoid.
895 : * This also tells toast_save_datum() to preserve the toast value
896 : * OIDs, which we want so as not to invalidate toast pointers in
897 : * system catalog caches, and to avoid making multiple copies of a
898 : * single toast value.
899 : *
900 : * Note that we must hold NewHeap open until we are done writing data,
901 : * since the relcache will not guarantee to remember this setting once
902 : * the relation is closed. Also, this technique depends on the fact
903 : * that no one will try to read from the NewHeap until after we've
904 : * finished writing it and swapping the rels --- otherwise they could
905 : * follow the toast pointers to the wrong place. (It would actually
906 : * work for values copied over from the old toast table, but not for
907 : * any values that we toast which were previously not toasted.)
908 : */
909 184 : NewHeap->rd_toastoid = OldHeap->rd_rel->reltoastrelid;
910 : }
911 : else
912 378 : *pSwapToastByContent = false;
913 :
914 : /*
915 : * Compute xids used to freeze and weed out dead tuples and multixacts.
916 : * Since we're going to rewrite the whole table anyway, there's no reason
917 : * not to be aggressive about this.
918 : */
919 562 : memset(¶ms, 0, sizeof(VacuumParams));
920 562 : vacuum_get_cutoffs(OldHeap, ¶ms, &cutoffs);
921 :
922 : /*
923 : * FreezeXid will become the table's new relfrozenxid, and that mustn't go
924 : * backwards, so take the max.
925 : */
926 : {
927 562 : TransactionId relfrozenxid = OldHeap->rd_rel->relfrozenxid;
928 :
929 1124 : if (TransactionIdIsValid(relfrozenxid) &&
930 562 : TransactionIdPrecedes(cutoffs.FreezeLimit, relfrozenxid))
931 96 : cutoffs.FreezeLimit = relfrozenxid;
932 : }
933 :
934 : /*
935 : * MultiXactCutoff, similarly, shouldn't go backwards either.
936 : */
937 : {
938 562 : MultiXactId relminmxid = OldHeap->rd_rel->relminmxid;
939 :
940 1124 : if (MultiXactIdIsValid(relminmxid) &&
941 562 : MultiXactIdPrecedes(cutoffs.MultiXactCutoff, relminmxid))
942 0 : cutoffs.MultiXactCutoff = relminmxid;
943 : }
944 :
945 : /*
946 : * Decide whether to use an indexscan or seqscan-and-optional-sort to scan
947 : * the OldHeap. We know how to use a sort to duplicate the ordering of a
948 : * btree index, and will use seqscan-and-sort for that case if the planner
949 : * tells us it's cheaper. Otherwise, always indexscan if an index is
950 : * provided, else plain seqscan.
951 : */
952 562 : if (OldIndex != NULL && OldIndex->rd_rel->relam == BTREE_AM_OID)
953 188 : use_sort = plan_cluster_use_sort(RelationGetRelid(OldHeap),
954 : RelationGetRelid(OldIndex));
955 : else
956 374 : use_sort = false;
957 :
958 : /* Log what we're doing */
959 562 : if (OldIndex != NULL && !use_sort)
960 78 : ereport(elevel,
961 : (errmsg("clustering \"%s.%s\" using index scan on \"%s\"",
962 : nspname,
963 : RelationGetRelationName(OldHeap),
964 : RelationGetRelationName(OldIndex))));
965 484 : else if (use_sort)
966 110 : ereport(elevel,
967 : (errmsg("clustering \"%s.%s\" using sequential scan and sort",
968 : nspname,
969 : RelationGetRelationName(OldHeap))));
970 : else
971 374 : ereport(elevel,
972 : (errmsg("vacuuming \"%s.%s\"",
973 : nspname,
974 : RelationGetRelationName(OldHeap))));
975 :
976 : /*
977 : * Hand off the actual copying to AM specific function, the generic code
978 : * cannot know how to deal with visibility across AMs. Note that this
979 : * routine is allowed to set FreezeXid / MultiXactCutoff to different
980 : * values (e.g. because the AM doesn't use freezing).
981 : */
982 562 : table_relation_copy_for_cluster(OldHeap, NewHeap, OldIndex, use_sort,
983 : cutoffs.OldestXmin, &cutoffs.FreezeLimit,
984 : &cutoffs.MultiXactCutoff,
985 : &num_tuples, &tups_vacuumed,
986 : &tups_recently_dead);
987 :
988 : /* return selected values to caller, get set as relfrozenxid/minmxid */
989 562 : *pFreezeXid = cutoffs.FreezeLimit;
990 562 : *pCutoffMulti = cutoffs.MultiXactCutoff;
991 :
992 : /* Reset rd_toastoid just to be tidy --- it shouldn't be looked at again */
993 562 : NewHeap->rd_toastoid = InvalidOid;
994 :
995 562 : num_pages = RelationGetNumberOfBlocks(NewHeap);
996 :
997 : /* Log what we did */
998 562 : ereport(elevel,
999 : (errmsg("\"%s.%s\": found %.0f removable, %.0f nonremovable row versions in %u pages",
1000 : nspname,
1001 : RelationGetRelationName(OldHeap),
1002 : tups_vacuumed, num_tuples,
1003 : RelationGetNumberOfBlocks(OldHeap)),
1004 : errdetail("%.0f dead row versions cannot be removed yet.\n"
1005 : "%s.",
1006 : tups_recently_dead,
1007 : pg_rusage_show(&ru0))));
1008 :
1009 : /* Update pg_class to reflect the correct values of pages and tuples. */
1010 562 : relRelation = table_open(RelationRelationId, RowExclusiveLock);
1011 :
1012 562 : reltup = SearchSysCacheCopy1(RELOID,
1013 : ObjectIdGetDatum(RelationGetRelid(NewHeap)));
1014 562 : if (!HeapTupleIsValid(reltup))
1015 0 : elog(ERROR, "cache lookup failed for relation %u",
1016 : RelationGetRelid(NewHeap));
1017 562 : relform = (Form_pg_class) GETSTRUCT(reltup);
1018 :
1019 562 : relform->relpages = num_pages;
1020 562 : relform->reltuples = num_tuples;
1021 :
1022 : /* Don't update the stats for pg_class. See swap_relation_files. */
1023 562 : if (RelationGetRelid(OldHeap) != RelationRelationId)
1024 518 : CatalogTupleUpdate(relRelation, &reltup->t_self, reltup);
1025 : else
1026 44 : CacheInvalidateRelcacheByTuple(reltup);
1027 :
1028 : /* Clean up. */
1029 562 : heap_freetuple(reltup);
1030 562 : table_close(relRelation, RowExclusiveLock);
1031 :
1032 : /* Make the update visible */
1033 562 : CommandCounterIncrement();
1034 562 : }
1035 :
1036 : /*
1037 : * Swap the physical files of two given relations.
1038 : *
1039 : * We swap the physical identity (reltablespace, relfilenumber) while keeping
1040 : * the same logical identities of the two relations. relpersistence is also
1041 : * swapped, which is critical since it determines where buffers live for each
1042 : * relation.
1043 : *
1044 : * We can swap associated TOAST data in either of two ways: recursively swap
1045 : * the physical content of the toast tables (and their indexes), or swap the
1046 : * TOAST links in the given relations' pg_class entries. The former is needed
1047 : * to manage rewrites of shared catalogs (where we cannot change the pg_class
1048 : * links) while the latter is the only way to handle cases in which a toast
1049 : * table is added or removed altogether.
1050 : *
1051 : * Additionally, the first relation is marked with relfrozenxid set to
1052 : * frozenXid. It seems a bit ugly to have this here, but the caller would
1053 : * have to do it anyway, so having it here saves a heap_update. Note: in
1054 : * the swap-toast-links case, we assume we don't need to change the toast
1055 : * table's relfrozenxid: the new version of the toast table should already
1056 : * have relfrozenxid set to RecentXmin, which is good enough.
1057 : *
1058 : * Lastly, if r2 and its toast table and toast index (if any) are mapped,
1059 : * their OIDs are emitted into mapped_tables[]. This is hacky but beats
1060 : * having to look the information up again later in finish_heap_swap.
1061 : */
1062 : static void
1063 2378 : swap_relation_files(Oid r1, Oid r2, bool target_is_pg_class,
1064 : bool swap_toast_by_content,
1065 : bool is_internal,
1066 : TransactionId frozenXid,
1067 : MultiXactId cutoffMulti,
1068 : Oid *mapped_tables)
1069 : {
1070 : Relation relRelation;
1071 : HeapTuple reltup1,
1072 : reltup2;
1073 : Form_pg_class relform1,
1074 : relform2;
1075 : RelFileNumber relfilenumber1,
1076 : relfilenumber2;
1077 : RelFileNumber swaptemp;
1078 : char swptmpchr;
1079 : Oid relam1,
1080 : relam2;
1081 :
1082 : /* We need writable copies of both pg_class tuples. */
1083 2378 : relRelation = table_open(RelationRelationId, RowExclusiveLock);
1084 :
1085 2378 : reltup1 = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(r1));
1086 2378 : if (!HeapTupleIsValid(reltup1))
1087 0 : elog(ERROR, "cache lookup failed for relation %u", r1);
1088 2378 : relform1 = (Form_pg_class) GETSTRUCT(reltup1);
1089 :
1090 2378 : reltup2 = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(r2));
1091 2378 : if (!HeapTupleIsValid(reltup2))
1092 0 : elog(ERROR, "cache lookup failed for relation %u", r2);
1093 2378 : relform2 = (Form_pg_class) GETSTRUCT(reltup2);
1094 :
1095 2378 : relfilenumber1 = relform1->relfilenode;
1096 2378 : relfilenumber2 = relform2->relfilenode;
1097 2378 : relam1 = relform1->relam;
1098 2378 : relam2 = relform2->relam;
1099 :
1100 2378 : if (RelFileNumberIsValid(relfilenumber1) &&
1101 : RelFileNumberIsValid(relfilenumber2))
1102 : {
1103 : /*
1104 : * Normal non-mapped relations: swap relfilenumbers, reltablespaces,
1105 : * relpersistence
1106 : */
1107 : Assert(!target_is_pg_class);
1108 :
1109 2204 : swaptemp = relform1->relfilenode;
1110 2204 : relform1->relfilenode = relform2->relfilenode;
1111 2204 : relform2->relfilenode = swaptemp;
1112 :
1113 2204 : swaptemp = relform1->reltablespace;
1114 2204 : relform1->reltablespace = relform2->reltablespace;
1115 2204 : relform2->reltablespace = swaptemp;
1116 :
1117 2204 : swaptemp = relform1->relam;
1118 2204 : relform1->relam = relform2->relam;
1119 2204 : relform2->relam = swaptemp;
1120 :
1121 2204 : swptmpchr = relform1->relpersistence;
1122 2204 : relform1->relpersistence = relform2->relpersistence;
1123 2204 : relform2->relpersistence = swptmpchr;
1124 :
1125 : /* Also swap toast links, if we're swapping by links */
1126 2204 : if (!swap_toast_by_content)
1127 : {
1128 1772 : swaptemp = relform1->reltoastrelid;
1129 1772 : relform1->reltoastrelid = relform2->reltoastrelid;
1130 1772 : relform2->reltoastrelid = swaptemp;
1131 : }
1132 : }
1133 : else
1134 : {
1135 : /*
1136 : * Mapped-relation case. Here we have to swap the relation mappings
1137 : * instead of modifying the pg_class columns. Both must be mapped.
1138 : */
1139 174 : if (RelFileNumberIsValid(relfilenumber1) ||
1140 : RelFileNumberIsValid(relfilenumber2))
1141 0 : elog(ERROR, "cannot swap mapped relation \"%s\" with non-mapped relation",
1142 : NameStr(relform1->relname));
1143 :
1144 : /*
1145 : * We can't change the tablespace nor persistence of a mapped rel, and
1146 : * we can't handle toast link swapping for one either, because we must
1147 : * not apply any critical changes to its pg_class row. These cases
1148 : * should be prevented by upstream permissions tests, so these checks
1149 : * are non-user-facing emergency backstop.
1150 : */
1151 174 : if (relform1->reltablespace != relform2->reltablespace)
1152 0 : elog(ERROR, "cannot change tablespace of mapped relation \"%s\"",
1153 : NameStr(relform1->relname));
1154 174 : if (relform1->relpersistence != relform2->relpersistence)
1155 0 : elog(ERROR, "cannot change persistence of mapped relation \"%s\"",
1156 : NameStr(relform1->relname));
1157 174 : if (relform1->relam != relform2->relam)
1158 0 : elog(ERROR, "cannot change access method of mapped relation \"%s\"",
1159 : NameStr(relform1->relname));
1160 174 : if (!swap_toast_by_content &&
1161 54 : (relform1->reltoastrelid || relform2->reltoastrelid))
1162 0 : elog(ERROR, "cannot swap toast by links for mapped relation \"%s\"",
1163 : NameStr(relform1->relname));
1164 :
1165 : /*
1166 : * Fetch the mappings --- shouldn't fail, but be paranoid
1167 : */
1168 174 : relfilenumber1 = RelationMapOidToFilenumber(r1, relform1->relisshared);
1169 174 : if (!RelFileNumberIsValid(relfilenumber1))
1170 0 : elog(ERROR, "could not find relation mapping for relation \"%s\", OID %u",
1171 : NameStr(relform1->relname), r1);
1172 174 : relfilenumber2 = RelationMapOidToFilenumber(r2, relform2->relisshared);
1173 174 : if (!RelFileNumberIsValid(relfilenumber2))
1174 0 : elog(ERROR, "could not find relation mapping for relation \"%s\", OID %u",
1175 : NameStr(relform2->relname), r2);
1176 :
1177 : /*
1178 : * Send replacement mappings to relmapper. Note these won't actually
1179 : * take effect until CommandCounterIncrement.
1180 : */
1181 174 : RelationMapUpdateMap(r1, relfilenumber2, relform1->relisshared, false);
1182 174 : RelationMapUpdateMap(r2, relfilenumber1, relform2->relisshared, false);
1183 :
1184 : /* Pass OIDs of mapped r2 tables back to caller */
1185 174 : *mapped_tables++ = r2;
1186 : }
1187 :
1188 : /*
1189 : * Recognize that rel1's relfilenumber (swapped from rel2) is new in this
1190 : * subtransaction. The rel2 storage (swapped from rel1) may or may not be
1191 : * new.
1192 : */
1193 : {
1194 : Relation rel1,
1195 : rel2;
1196 :
1197 2378 : rel1 = relation_open(r1, NoLock);
1198 2378 : rel2 = relation_open(r2, NoLock);
1199 2378 : rel2->rd_createSubid = rel1->rd_createSubid;
1200 2378 : rel2->rd_newRelfilelocatorSubid = rel1->rd_newRelfilelocatorSubid;
1201 2378 : rel2->rd_firstRelfilelocatorSubid = rel1->rd_firstRelfilelocatorSubid;
1202 2378 : RelationAssumeNewRelfilelocator(rel1);
1203 2378 : relation_close(rel1, NoLock);
1204 2378 : relation_close(rel2, NoLock);
1205 : }
1206 :
1207 : /*
1208 : * In the case of a shared catalog, these next few steps will only affect
1209 : * our own database's pg_class row; but that's okay, because they are all
1210 : * noncritical updates. That's also an important fact for the case of a
1211 : * mapped catalog, because it's possible that we'll commit the map change
1212 : * and then fail to commit the pg_class update.
1213 : */
1214 :
1215 : /* set rel1's frozen Xid and minimum MultiXid */
1216 2378 : if (relform1->relkind != RELKIND_INDEX)
1217 : {
1218 : Assert(!TransactionIdIsValid(frozenXid) ||
1219 : TransactionIdIsNormal(frozenXid));
1220 2194 : relform1->relfrozenxid = frozenXid;
1221 2194 : relform1->relminmxid = cutoffMulti;
1222 : }
1223 :
1224 : /* swap size statistics too, since new rel has freshly-updated stats */
1225 : {
1226 : int32 swap_pages;
1227 : float4 swap_tuples;
1228 : int32 swap_allvisible;
1229 : int32 swap_allfrozen;
1230 :
1231 2378 : swap_pages = relform1->relpages;
1232 2378 : relform1->relpages = relform2->relpages;
1233 2378 : relform2->relpages = swap_pages;
1234 :
1235 2378 : swap_tuples = relform1->reltuples;
1236 2378 : relform1->reltuples = relform2->reltuples;
1237 2378 : relform2->reltuples = swap_tuples;
1238 :
1239 2378 : swap_allvisible = relform1->relallvisible;
1240 2378 : relform1->relallvisible = relform2->relallvisible;
1241 2378 : relform2->relallvisible = swap_allvisible;
1242 :
1243 2378 : swap_allfrozen = relform1->relallfrozen;
1244 2378 : relform1->relallfrozen = relform2->relallfrozen;
1245 2378 : relform2->relallfrozen = swap_allfrozen;
1246 : }
1247 :
1248 : /*
1249 : * Update the tuples in pg_class --- unless the target relation of the
1250 : * swap is pg_class itself. In that case, there is zero point in making
1251 : * changes because we'd be updating the old data that we're about to throw
1252 : * away. Because the real work being done here for a mapped relation is
1253 : * just to change the relation map settings, it's all right to not update
1254 : * the pg_class rows in this case. The most important changes will instead
1255 : * performed later, in finish_heap_swap() itself.
1256 : */
1257 2378 : if (!target_is_pg_class)
1258 : {
1259 : CatalogIndexState indstate;
1260 :
1261 2334 : indstate = CatalogOpenIndexes(relRelation);
1262 2334 : CatalogTupleUpdateWithInfo(relRelation, &reltup1->t_self, reltup1,
1263 : indstate);
1264 2334 : CatalogTupleUpdateWithInfo(relRelation, &reltup2->t_self, reltup2,
1265 : indstate);
1266 2334 : CatalogCloseIndexes(indstate);
1267 : }
1268 : else
1269 : {
1270 : /* no update ... but we do still need relcache inval */
1271 44 : CacheInvalidateRelcacheByTuple(reltup1);
1272 44 : CacheInvalidateRelcacheByTuple(reltup2);
1273 : }
1274 :
1275 : /*
1276 : * Now that pg_class has been updated with its relevant information for
1277 : * the swap, update the dependency of the relations to point to their new
1278 : * table AM, if it has changed.
1279 : */
1280 2378 : if (relam1 != relam2)
1281 : {
1282 36 : if (changeDependencyFor(RelationRelationId,
1283 : r1,
1284 : AccessMethodRelationId,
1285 : relam1,
1286 : relam2) != 1)
1287 0 : elog(ERROR, "could not change access method dependency for relation \"%s.%s\"",
1288 : get_namespace_name(get_rel_namespace(r1)),
1289 : get_rel_name(r1));
1290 36 : if (changeDependencyFor(RelationRelationId,
1291 : r2,
1292 : AccessMethodRelationId,
1293 : relam2,
1294 : relam1) != 1)
1295 0 : elog(ERROR, "could not change access method dependency for relation \"%s.%s\"",
1296 : get_namespace_name(get_rel_namespace(r2)),
1297 : get_rel_name(r2));
1298 : }
1299 :
1300 : /*
1301 : * Post alter hook for modified relations. The change to r2 is always
1302 : * internal, but r1 depends on the invocation context.
1303 : */
1304 2378 : InvokeObjectPostAlterHookArg(RelationRelationId, r1, 0,
1305 : InvalidOid, is_internal);
1306 2378 : InvokeObjectPostAlterHookArg(RelationRelationId, r2, 0,
1307 : InvalidOid, true);
1308 :
1309 : /*
1310 : * If we have toast tables associated with the relations being swapped,
1311 : * deal with them too.
1312 : */
1313 2378 : if (relform1->reltoastrelid || relform2->reltoastrelid)
1314 : {
1315 826 : if (swap_toast_by_content)
1316 : {
1317 184 : if (relform1->reltoastrelid && relform2->reltoastrelid)
1318 : {
1319 : /* Recursively swap the contents of the toast tables */
1320 184 : swap_relation_files(relform1->reltoastrelid,
1321 : relform2->reltoastrelid,
1322 : target_is_pg_class,
1323 : swap_toast_by_content,
1324 : is_internal,
1325 : frozenXid,
1326 : cutoffMulti,
1327 : mapped_tables);
1328 : }
1329 : else
1330 : {
1331 : /* caller messed up */
1332 0 : elog(ERROR, "cannot swap toast files by content when there's only one");
1333 : }
1334 : }
1335 : else
1336 : {
1337 : /*
1338 : * We swapped the ownership links, so we need to change dependency
1339 : * data to match.
1340 : *
1341 : * NOTE: it is possible that only one table has a toast table.
1342 : *
1343 : * NOTE: at present, a TOAST table's only dependency is the one on
1344 : * its owning table. If more are ever created, we'd need to use
1345 : * something more selective than deleteDependencyRecordsFor() to
1346 : * get rid of just the link we want.
1347 : */
1348 : ObjectAddress baseobject,
1349 : toastobject;
1350 : long count;
1351 :
1352 : /*
1353 : * We disallow this case for system catalogs, to avoid the
1354 : * possibility that the catalog we're rebuilding is one of the
1355 : * ones the dependency changes would change. It's too late to be
1356 : * making any data changes to the target catalog.
1357 : */
1358 642 : if (IsSystemClass(r1, relform1))
1359 0 : elog(ERROR, "cannot swap toast files by links for system catalogs");
1360 :
1361 : /* Delete old dependencies */
1362 642 : if (relform1->reltoastrelid)
1363 : {
1364 610 : count = deleteDependencyRecordsFor(RelationRelationId,
1365 : relform1->reltoastrelid,
1366 : false);
1367 610 : if (count != 1)
1368 0 : elog(ERROR, "expected one dependency record for TOAST table, found %ld",
1369 : count);
1370 : }
1371 642 : if (relform2->reltoastrelid)
1372 : {
1373 642 : count = deleteDependencyRecordsFor(RelationRelationId,
1374 : relform2->reltoastrelid,
1375 : false);
1376 642 : if (count != 1)
1377 0 : elog(ERROR, "expected one dependency record for TOAST table, found %ld",
1378 : count);
1379 : }
1380 :
1381 : /* Register new dependencies */
1382 642 : baseobject.classId = RelationRelationId;
1383 642 : baseobject.objectSubId = 0;
1384 642 : toastobject.classId = RelationRelationId;
1385 642 : toastobject.objectSubId = 0;
1386 :
1387 642 : if (relform1->reltoastrelid)
1388 : {
1389 610 : baseobject.objectId = r1;
1390 610 : toastobject.objectId = relform1->reltoastrelid;
1391 610 : recordDependencyOn(&toastobject, &baseobject,
1392 : DEPENDENCY_INTERNAL);
1393 : }
1394 :
1395 642 : if (relform2->reltoastrelid)
1396 : {
1397 642 : baseobject.objectId = r2;
1398 642 : toastobject.objectId = relform2->reltoastrelid;
1399 642 : recordDependencyOn(&toastobject, &baseobject,
1400 : DEPENDENCY_INTERNAL);
1401 : }
1402 : }
1403 : }
1404 :
1405 : /*
1406 : * If we're swapping two toast tables by content, do the same for their
1407 : * valid index. The swap can actually be safely done only if the relations
1408 : * have indexes.
1409 : */
1410 2378 : if (swap_toast_by_content &&
1411 552 : relform1->relkind == RELKIND_TOASTVALUE &&
1412 184 : relform2->relkind == RELKIND_TOASTVALUE)
1413 : {
1414 : Oid toastIndex1,
1415 : toastIndex2;
1416 :
1417 : /* Get valid index for each relation */
1418 184 : toastIndex1 = toast_get_valid_index(r1,
1419 : AccessExclusiveLock);
1420 184 : toastIndex2 = toast_get_valid_index(r2,
1421 : AccessExclusiveLock);
1422 :
1423 184 : swap_relation_files(toastIndex1,
1424 : toastIndex2,
1425 : target_is_pg_class,
1426 : swap_toast_by_content,
1427 : is_internal,
1428 : InvalidTransactionId,
1429 : InvalidMultiXactId,
1430 : mapped_tables);
1431 : }
1432 :
1433 : /* Clean up. */
1434 2378 : heap_freetuple(reltup1);
1435 2378 : heap_freetuple(reltup2);
1436 :
1437 2378 : table_close(relRelation, RowExclusiveLock);
1438 2378 : }
1439 :
1440 : /*
1441 : * Remove the transient table that was built by make_new_heap, and finish
1442 : * cleaning up (including rebuilding all indexes on the old heap).
1443 : */
1444 : void
1445 2010 : finish_heap_swap(Oid OIDOldHeap, Oid OIDNewHeap,
1446 : bool is_system_catalog,
1447 : bool swap_toast_by_content,
1448 : bool check_constraints,
1449 : bool is_internal,
1450 : TransactionId frozenXid,
1451 : MultiXactId cutoffMulti,
1452 : char newrelpersistence)
1453 : {
1454 : ObjectAddress object;
1455 : Oid mapped_tables[4];
1456 : int reindex_flags;
1457 2010 : ReindexParams reindex_params = {0};
1458 : int i;
1459 :
1460 : /* Report that we are now swapping relation files */
1461 2010 : pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
1462 : PROGRESS_CLUSTER_PHASE_SWAP_REL_FILES);
1463 :
1464 : /* Zero out possible results from swapped_relation_files */
1465 2010 : memset(mapped_tables, 0, sizeof(mapped_tables));
1466 :
1467 : /*
1468 : * Swap the contents of the heap relations (including any toast tables).
1469 : * Also set old heap's relfrozenxid to frozenXid.
1470 : */
1471 2010 : swap_relation_files(OIDOldHeap, OIDNewHeap,
1472 : (OIDOldHeap == RelationRelationId),
1473 : swap_toast_by_content, is_internal,
1474 : frozenXid, cutoffMulti, mapped_tables);
1475 :
1476 : /*
1477 : * If it's a system catalog, queue a sinval message to flush all catcaches
1478 : * on the catalog when we reach CommandCounterIncrement.
1479 : */
1480 2010 : if (is_system_catalog)
1481 222 : CacheInvalidateCatalog(OIDOldHeap);
1482 :
1483 : /*
1484 : * Rebuild each index on the relation (but not the toast table, which is
1485 : * all-new at this point). It is important to do this before the DROP
1486 : * step because if we are processing a system catalog that will be used
1487 : * during DROP, we want to have its indexes available. There is no
1488 : * advantage to the other order anyway because this is all transactional,
1489 : * so no chance to reclaim disk space before commit. We do not need a
1490 : * final CommandCounterIncrement() because reindex_relation does it.
1491 : *
1492 : * Note: because index_build is called via reindex_relation, it will never
1493 : * set indcheckxmin true for the indexes. This is OK even though in some
1494 : * sense we are building new indexes rather than rebuilding existing ones,
1495 : * because the new heap won't contain any HOT chains at all, let alone
1496 : * broken ones, so it can't be necessary to set indcheckxmin.
1497 : */
1498 2010 : reindex_flags = REINDEX_REL_SUPPRESS_INDEX_USE;
1499 2010 : if (check_constraints)
1500 1448 : reindex_flags |= REINDEX_REL_CHECK_CONSTRAINTS;
1501 :
1502 : /*
1503 : * Ensure that the indexes have the same persistence as the parent
1504 : * relation.
1505 : */
1506 2010 : if (newrelpersistence == RELPERSISTENCE_UNLOGGED)
1507 38 : reindex_flags |= REINDEX_REL_FORCE_INDEXES_UNLOGGED;
1508 1972 : else if (newrelpersistence == RELPERSISTENCE_PERMANENT)
1509 1892 : reindex_flags |= REINDEX_REL_FORCE_INDEXES_PERMANENT;
1510 :
1511 : /* Report that we are now reindexing relations */
1512 2010 : pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
1513 : PROGRESS_CLUSTER_PHASE_REBUILD_INDEX);
1514 :
1515 2010 : reindex_relation(NULL, OIDOldHeap, reindex_flags, &reindex_params);
1516 :
1517 : /* Report that we are now doing clean up */
1518 1992 : pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
1519 : PROGRESS_CLUSTER_PHASE_FINAL_CLEANUP);
1520 :
1521 : /*
1522 : * If the relation being rebuilt is pg_class, swap_relation_files()
1523 : * couldn't update pg_class's own pg_class entry (check comments in
1524 : * swap_relation_files()), thus relfrozenxid was not updated. That's
1525 : * annoying because a potential reason for doing a VACUUM FULL is a
1526 : * imminent or actual anti-wraparound shutdown. So, now that we can
1527 : * access the new relation using its indices, update relfrozenxid.
1528 : * pg_class doesn't have a toast relation, so we don't need to update the
1529 : * corresponding toast relation. Not that there's little point moving all
1530 : * relfrozenxid updates here since swap_relation_files() needs to write to
1531 : * pg_class for non-mapped relations anyway.
1532 : */
1533 1992 : if (OIDOldHeap == RelationRelationId)
1534 : {
1535 : Relation relRelation;
1536 : HeapTuple reltup;
1537 : Form_pg_class relform;
1538 :
1539 44 : relRelation = table_open(RelationRelationId, RowExclusiveLock);
1540 :
1541 44 : reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(OIDOldHeap));
1542 44 : if (!HeapTupleIsValid(reltup))
1543 0 : elog(ERROR, "cache lookup failed for relation %u", OIDOldHeap);
1544 44 : relform = (Form_pg_class) GETSTRUCT(reltup);
1545 :
1546 44 : relform->relfrozenxid = frozenXid;
1547 44 : relform->relminmxid = cutoffMulti;
1548 :
1549 44 : CatalogTupleUpdate(relRelation, &reltup->t_self, reltup);
1550 :
1551 44 : table_close(relRelation, RowExclusiveLock);
1552 : }
1553 :
1554 : /* Destroy new heap with old filenumber */
1555 1992 : object.classId = RelationRelationId;
1556 1992 : object.objectId = OIDNewHeap;
1557 1992 : object.objectSubId = 0;
1558 :
1559 : /*
1560 : * The new relation is local to our transaction and we know nothing
1561 : * depends on it, so DROP_RESTRICT should be OK.
1562 : */
1563 1992 : performDeletion(&object, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
1564 :
1565 : /* performDeletion does CommandCounterIncrement at end */
1566 :
1567 : /*
1568 : * Now we must remove any relation mapping entries that we set up for the
1569 : * transient table, as well as its toast table and toast index if any. If
1570 : * we fail to do this before commit, the relmapper will complain about new
1571 : * permanent map entries being added post-bootstrap.
1572 : */
1573 2166 : for (i = 0; OidIsValid(mapped_tables[i]); i++)
1574 174 : RelationMapRemoveMapping(mapped_tables[i]);
1575 :
1576 : /*
1577 : * At this point, everything is kosher except that, if we did toast swap
1578 : * by links, the toast table's name corresponds to the transient table.
1579 : * The name is irrelevant to the backend because it's referenced by OID,
1580 : * but users looking at the catalogs could be confused. Rename it to
1581 : * prevent this problem.
1582 : *
1583 : * Note no lock required on the relation, because we already hold an
1584 : * exclusive lock on it.
1585 : */
1586 1992 : if (!swap_toast_by_content)
1587 : {
1588 : Relation newrel;
1589 :
1590 1808 : newrel = table_open(OIDOldHeap, NoLock);
1591 1808 : if (OidIsValid(newrel->rd_rel->reltoastrelid))
1592 : {
1593 : Oid toastidx;
1594 : char NewToastName[NAMEDATALEN];
1595 :
1596 : /* Get the associated valid index to be renamed */
1597 610 : toastidx = toast_get_valid_index(newrel->rd_rel->reltoastrelid,
1598 : NoLock);
1599 :
1600 : /* rename the toast table ... */
1601 610 : snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u",
1602 : OIDOldHeap);
1603 610 : RenameRelationInternal(newrel->rd_rel->reltoastrelid,
1604 : NewToastName, true, false);
1605 :
1606 : /* ... and its valid index too. */
1607 610 : snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u_index",
1608 : OIDOldHeap);
1609 :
1610 610 : RenameRelationInternal(toastidx,
1611 : NewToastName, true, true);
1612 :
1613 : /*
1614 : * Reset the relrewrite for the toast. The command-counter
1615 : * increment is required here as we are about to update the tuple
1616 : * that is updated as part of RenameRelationInternal.
1617 : */
1618 610 : CommandCounterIncrement();
1619 610 : ResetRelRewrite(newrel->rd_rel->reltoastrelid);
1620 : }
1621 1808 : relation_close(newrel, NoLock);
1622 : }
1623 :
1624 : /* if it's not a catalog table, clear any missing attribute settings */
1625 1992 : if (!is_system_catalog)
1626 : {
1627 : Relation newrel;
1628 :
1629 1770 : newrel = table_open(OIDOldHeap, NoLock);
1630 1770 : RelationClearMissing(newrel);
1631 1770 : relation_close(newrel, NoLock);
1632 : }
1633 1992 : }
1634 :
1635 :
1636 : /*
1637 : * Get a list of tables that the current user has privileges on and
1638 : * have indisclustered set. Return the list in a List * of RelToCluster
1639 : * (stored in the specified memory context), each one giving the tableOid
1640 : * and the indexOid on which the table is already clustered.
1641 : */
1642 : static List *
1643 30 : get_tables_to_cluster(MemoryContext cluster_context)
1644 : {
1645 : Relation indRelation;
1646 : TableScanDesc scan;
1647 : ScanKeyData entry;
1648 : HeapTuple indexTuple;
1649 : Form_pg_index index;
1650 : MemoryContext old_context;
1651 30 : List *rtcs = NIL;
1652 :
1653 : /*
1654 : * Get all indexes that have indisclustered set and that the current user
1655 : * has the appropriate privileges for.
1656 : */
1657 30 : indRelation = table_open(IndexRelationId, AccessShareLock);
1658 30 : ScanKeyInit(&entry,
1659 : Anum_pg_index_indisclustered,
1660 : BTEqualStrategyNumber, F_BOOLEQ,
1661 : BoolGetDatum(true));
1662 30 : scan = table_beginscan_catalog(indRelation, 1, &entry);
1663 48 : while ((indexTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
1664 : {
1665 : RelToCluster *rtc;
1666 :
1667 18 : index = (Form_pg_index) GETSTRUCT(indexTuple);
1668 :
1669 18 : if (!cluster_is_permitted_for_relation(index->indrelid, GetUserId()))
1670 12 : continue;
1671 :
1672 : /* Use a permanent memory context for the result list */
1673 6 : old_context = MemoryContextSwitchTo(cluster_context);
1674 :
1675 6 : rtc = (RelToCluster *) palloc(sizeof(RelToCluster));
1676 6 : rtc->tableOid = index->indrelid;
1677 6 : rtc->indexOid = index->indexrelid;
1678 6 : rtcs = lappend(rtcs, rtc);
1679 :
1680 6 : MemoryContextSwitchTo(old_context);
1681 : }
1682 30 : table_endscan(scan);
1683 :
1684 30 : relation_close(indRelation, AccessShareLock);
1685 :
1686 30 : return rtcs;
1687 : }
1688 :
1689 : /*
1690 : * Given an index on a partitioned table, return a list of RelToCluster for
1691 : * all the children leaves tables/indexes.
1692 : *
1693 : * Like expand_vacuum_rel, but here caller must hold AccessExclusiveLock
1694 : * on the table containing the index.
1695 : */
1696 : static List *
1697 20 : get_tables_to_cluster_partitioned(MemoryContext cluster_context, Oid indexOid)
1698 : {
1699 : List *inhoids;
1700 : ListCell *lc;
1701 20 : List *rtcs = NIL;
1702 : MemoryContext old_context;
1703 :
1704 : /* Do not lock the children until they're processed */
1705 20 : inhoids = find_all_inheritors(indexOid, NoLock, NULL);
1706 :
1707 104 : foreach(lc, inhoids)
1708 : {
1709 84 : Oid indexrelid = lfirst_oid(lc);
1710 84 : Oid relid = IndexGetRelation(indexrelid, false);
1711 : RelToCluster *rtc;
1712 :
1713 : /* consider only leaf indexes */
1714 84 : if (get_rel_relkind(indexrelid) != RELKIND_INDEX)
1715 38 : continue;
1716 :
1717 : /*
1718 : * It's possible that the user does not have privileges to CLUSTER the
1719 : * leaf partition despite having such privileges on the partitioned
1720 : * table. We skip any partitions which the user is not permitted to
1721 : * CLUSTER.
1722 : */
1723 46 : if (!cluster_is_permitted_for_relation(relid, GetUserId()))
1724 22 : continue;
1725 :
1726 : /* Use a permanent memory context for the result list */
1727 24 : old_context = MemoryContextSwitchTo(cluster_context);
1728 :
1729 24 : rtc = (RelToCluster *) palloc(sizeof(RelToCluster));
1730 24 : rtc->tableOid = relid;
1731 24 : rtc->indexOid = indexrelid;
1732 24 : rtcs = lappend(rtcs, rtc);
1733 :
1734 24 : MemoryContextSwitchTo(old_context);
1735 : }
1736 :
1737 20 : return rtcs;
1738 : }
1739 :
1740 : /*
1741 : * Return whether userid has privileges to CLUSTER relid. If not, this
1742 : * function emits a WARNING.
1743 : */
1744 : static bool
1745 94 : cluster_is_permitted_for_relation(Oid relid, Oid userid)
1746 : {
1747 94 : if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
1748 60 : return true;
1749 :
1750 34 : ereport(WARNING,
1751 : (errmsg("permission denied to cluster \"%s\", skipping it",
1752 : get_rel_name(relid))));
1753 34 : return false;
1754 : }
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