Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * toasting.c
4 : * This file contains routines to support creation of toast tables
5 : *
6 : *
7 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
8 : * Portions Copyright (c) 1994, Regents of the University of California
9 : *
10 : * IDENTIFICATION
11 : * src/backend/catalog/toasting.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres.h"
16 :
17 : #include "access/heapam.h"
18 : #include "access/toast_compression.h"
19 : #include "access/xact.h"
20 : #include "catalog/binary_upgrade.h"
21 : #include "catalog/catalog.h"
22 : #include "catalog/dependency.h"
23 : #include "catalog/heap.h"
24 : #include "catalog/index.h"
25 : #include "catalog/namespace.h"
26 : #include "catalog/pg_am.h"
27 : #include "catalog/pg_namespace.h"
28 : #include "catalog/pg_opclass.h"
29 : #include "catalog/toasting.h"
30 : #include "miscadmin.h"
31 : #include "nodes/makefuncs.h"
32 : #include "utils/fmgroids.h"
33 : #include "utils/rel.h"
34 : #include "utils/syscache.h"
35 :
36 : static void CheckAndCreateToastTable(Oid relOid, Datum reloptions,
37 : LOCKMODE lockmode, bool check,
38 : Oid OIDOldToast);
39 : static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
40 : Datum reloptions, LOCKMODE lockmode, bool check,
41 : Oid OIDOldToast);
42 : static bool needs_toast_table(Relation rel);
43 :
44 :
45 : /*
46 : * CreateToastTable variants
47 : * If the table needs a toast table, and doesn't already have one,
48 : * then create a toast table for it.
49 : *
50 : * reloptions for the toast table can be passed, too. Pass (Datum) 0
51 : * for default reloptions.
52 : *
53 : * We expect the caller to have verified that the relation is a table and have
54 : * already done any necessary permission checks. Callers expect this function
55 : * to end with CommandCounterIncrement if it makes any changes.
56 : */
57 : void
58 15258 : AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
59 : {
60 15258 : CheckAndCreateToastTable(relOid, reloptions, lockmode, true, InvalidOid);
61 15258 : }
62 :
63 : void
64 433 : NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
65 : Oid OIDOldToast)
66 : {
67 433 : CheckAndCreateToastTable(relOid, reloptions, lockmode, false, OIDOldToast);
68 433 : }
69 :
70 : void
71 20116 : NewRelationCreateToastTable(Oid relOid, Datum reloptions)
72 : {
73 20116 : CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false,
74 : InvalidOid);
75 20116 : }
76 :
77 : static void
78 35807 : CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
79 : bool check, Oid OIDOldToast)
80 : {
81 : Relation rel;
82 :
83 35807 : rel = table_open(relOid, lockmode);
84 :
85 : /* create_toast_table does all the work */
86 35807 : (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode,
87 : check, OIDOldToast);
88 :
89 35807 : table_close(rel, NoLock);
90 35807 : }
91 :
92 : /*
93 : * Create a toast table during bootstrap
94 : *
95 : * Here we need to prespecify the OIDs of the toast table and its index
96 : */
97 : void
98 1785 : BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
99 : {
100 : Relation rel;
101 :
102 1785 : rel = table_openrv(makeRangeVar(NULL, relName, -1), AccessExclusiveLock);
103 :
104 1785 : if (rel->rd_rel->relkind != RELKIND_RELATION &&
105 0 : rel->rd_rel->relkind != RELKIND_MATVIEW)
106 0 : elog(ERROR, "\"%s\" is not a table or materialized view",
107 : relName);
108 :
109 : /* create_toast_table does all the work */
110 1785 : if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0,
111 : AccessExclusiveLock, false, InvalidOid))
112 0 : elog(ERROR, "\"%s\" does not require a toast table",
113 : relName);
114 :
115 1785 : table_close(rel, NoLock);
116 1785 : }
117 :
118 :
119 : /*
120 : * create_toast_table --- internal workhorse
121 : *
122 : * rel is already opened and locked
123 : * toastOid and toastIndexOid are normally InvalidOid, but during
124 : * bootstrap they can be nonzero to specify hand-assigned OIDs
125 : */
126 : static bool
127 37592 : create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
128 : Datum reloptions, LOCKMODE lockmode, bool check,
129 : Oid OIDOldToast)
130 : {
131 37592 : Oid relOid = RelationGetRelid(rel);
132 : HeapTuple reltup;
133 : TupleDesc tupdesc;
134 : bool shared_relation;
135 : bool mapped_relation;
136 : Relation toast_rel;
137 : Relation class_rel;
138 : Oid toast_relid;
139 : Oid namespaceid;
140 : char toast_relname[NAMEDATALEN];
141 : char toast_idxname[NAMEDATALEN];
142 : IndexInfo *indexInfo;
143 : Oid collationIds[2];
144 : Oid opclassIds[2];
145 : int16 coloptions[2];
146 : ObjectAddress baseobject,
147 : toastobject;
148 :
149 : /*
150 : * Is it already toasted?
151 : */
152 37592 : if (rel->rd_rel->reltoastrelid != InvalidOid)
153 5430 : return false;
154 :
155 : /*
156 : * Check to see whether the table actually needs a TOAST table.
157 : */
158 32162 : if (!IsBinaryUpgrade)
159 : {
160 : /* Normal mode, normal check */
161 30421 : if (!needs_toast_table(rel))
162 21673 : return false;
163 : }
164 : else
165 : {
166 : /*
167 : * In binary-upgrade mode, create a TOAST table if and only if
168 : * pg_upgrade told us to (ie, a TOAST table OID has been provided).
169 : *
170 : * This indicates that the old cluster had a TOAST table for the
171 : * current table. We must create a TOAST table to receive the old
172 : * TOAST file, even if the table seems not to need one.
173 : *
174 : * Contrariwise, if the old cluster did not have a TOAST table, we
175 : * should be able to get along without one even if the new version's
176 : * needs_toast_table rules suggest we should have one. There is a lot
177 : * of daylight between where we will create a TOAST table and where
178 : * one is really necessary to avoid failures, so small cross-version
179 : * differences in the when-to-create heuristic shouldn't be a problem.
180 : * If we tried to create a TOAST table anyway, we would have the
181 : * problem that it might take up an OID that will conflict with some
182 : * old-cluster table we haven't seen yet.
183 : */
184 1741 : if (!OidIsValid(binary_upgrade_next_toast_pg_class_oid))
185 1471 : return false;
186 : }
187 :
188 : /*
189 : * If requested check lockmode is sufficient. This is a cross check in
190 : * case of errors or conflicting decisions in earlier code.
191 : */
192 9018 : if (check && lockmode != AccessExclusiveLock)
193 0 : elog(ERROR, "AccessExclusiveLock required to add toast table.");
194 :
195 : /*
196 : * Create the toast table and its index
197 : */
198 9018 : snprintf(toast_relname, sizeof(toast_relname),
199 : "pg_toast_%u", relOid);
200 9018 : snprintf(toast_idxname, sizeof(toast_idxname),
201 : "pg_toast_%u_index", relOid);
202 :
203 : /* this is pretty painful... need a tuple descriptor */
204 9018 : tupdesc = CreateTemplateTupleDesc(3);
205 9018 : TupleDescInitEntry(tupdesc, (AttrNumber) 1,
206 : "chunk_id",
207 : OIDOID,
208 : -1, 0);
209 9018 : TupleDescInitEntry(tupdesc, (AttrNumber) 2,
210 : "chunk_seq",
211 : INT4OID,
212 : -1, 0);
213 9018 : TupleDescInitEntry(tupdesc, (AttrNumber) 3,
214 : "chunk_data",
215 : BYTEAOID,
216 : -1, 0);
217 :
218 : /*
219 : * Ensure that the toast table doesn't itself get toasted, or we'll be
220 : * toast :-(. This is essential for chunk_data because type bytea is
221 : * toastable; hit the other two just to be sure.
222 : */
223 9018 : TupleDescAttr(tupdesc, 0)->attstorage = TYPSTORAGE_PLAIN;
224 9018 : TupleDescAttr(tupdesc, 1)->attstorage = TYPSTORAGE_PLAIN;
225 9018 : TupleDescAttr(tupdesc, 2)->attstorage = TYPSTORAGE_PLAIN;
226 :
227 : /* Toast field should not be compressed */
228 9018 : TupleDescAttr(tupdesc, 0)->attcompression = InvalidCompressionMethod;
229 9018 : TupleDescAttr(tupdesc, 1)->attcompression = InvalidCompressionMethod;
230 9018 : TupleDescAttr(tupdesc, 2)->attcompression = InvalidCompressionMethod;
231 :
232 : /*
233 : * Toast tables for regular relations go in pg_toast; those for temp
234 : * relations go into the per-backend temp-toast-table namespace.
235 : */
236 9018 : if (isTempOrTempToastNamespace(rel->rd_rel->relnamespace))
237 477 : namespaceid = GetTempToastNamespace();
238 : else
239 8541 : namespaceid = PG_TOAST_NAMESPACE;
240 :
241 : /* Toast table is shared if and only if its parent is. */
242 9018 : shared_relation = rel->rd_rel->relisshared;
243 :
244 : /* It's mapped if and only if its parent is, too */
245 9018 : mapped_relation = RelationIsMapped(rel);
246 :
247 18036 : toast_relid = heap_create_with_catalog(toast_relname,
248 : namespaceid,
249 9018 : rel->rd_rel->reltablespace,
250 : toastOid,
251 : InvalidOid,
252 : InvalidOid,
253 9018 : rel->rd_rel->relowner,
254 : table_relation_toast_am(rel),
255 : tupdesc,
256 : NIL,
257 : RELKIND_TOASTVALUE,
258 9018 : rel->rd_rel->relpersistence,
259 : shared_relation,
260 : mapped_relation,
261 : ONCOMMIT_NOOP,
262 : reloptions,
263 : false,
264 : true,
265 : true,
266 : OIDOldToast,
267 : NULL);
268 : Assert(toast_relid != InvalidOid);
269 :
270 : /* make the toast relation visible, else table_open will fail */
271 9018 : CommandCounterIncrement();
272 :
273 : /* ShareLock is not really needed here, but take it anyway */
274 9018 : toast_rel = table_open(toast_relid, ShareLock);
275 :
276 : /*
277 : * Create unique index on chunk_id, chunk_seq.
278 : *
279 : * NOTE: the normal TOAST access routines could actually function with a
280 : * single-column index on chunk_id only. However, the slice access
281 : * routines use both columns for faster access to an individual chunk. In
282 : * addition, we want it to be unique as a check against the possibility of
283 : * duplicate TOAST chunk OIDs. The index might also be a little more
284 : * efficient this way, since btree isn't all that happy with large numbers
285 : * of equal keys.
286 : */
287 :
288 9018 : indexInfo = makeNode(IndexInfo);
289 9018 : indexInfo->ii_NumIndexAttrs = 2;
290 9018 : indexInfo->ii_NumIndexKeyAttrs = 2;
291 9018 : indexInfo->ii_IndexAttrNumbers[0] = 1;
292 9018 : indexInfo->ii_IndexAttrNumbers[1] = 2;
293 9018 : indexInfo->ii_Expressions = NIL;
294 9018 : indexInfo->ii_ExpressionsState = NIL;
295 9018 : indexInfo->ii_Predicate = NIL;
296 9018 : indexInfo->ii_PredicateState = NULL;
297 9018 : indexInfo->ii_ExclusionOps = NULL;
298 9018 : indexInfo->ii_ExclusionProcs = NULL;
299 9018 : indexInfo->ii_ExclusionStrats = NULL;
300 9018 : indexInfo->ii_Unique = true;
301 9018 : indexInfo->ii_NullsNotDistinct = false;
302 9018 : indexInfo->ii_ReadyForInserts = true;
303 9018 : indexInfo->ii_CheckedUnchanged = false;
304 9018 : indexInfo->ii_IndexUnchanged = false;
305 9018 : indexInfo->ii_Concurrent = false;
306 9018 : indexInfo->ii_BrokenHotChain = false;
307 9018 : indexInfo->ii_ParallelWorkers = 0;
308 9018 : indexInfo->ii_Am = BTREE_AM_OID;
309 9018 : indexInfo->ii_AmCache = NULL;
310 9018 : indexInfo->ii_Context = CurrentMemoryContext;
311 :
312 9018 : collationIds[0] = InvalidOid;
313 9018 : collationIds[1] = InvalidOid;
314 :
315 9018 : opclassIds[0] = OID_BTREE_OPS_OID;
316 9018 : opclassIds[1] = INT4_BTREE_OPS_OID;
317 :
318 9018 : coloptions[0] = 0;
319 9018 : coloptions[1] = 0;
320 :
321 9018 : index_create(toast_rel, toast_idxname, toastIndexOid, InvalidOid,
322 : InvalidOid, InvalidOid,
323 : indexInfo,
324 9018 : list_make2("chunk_id", "chunk_seq"),
325 : BTREE_AM_OID,
326 9018 : rel->rd_rel->reltablespace,
327 : collationIds, opclassIds, NULL, coloptions, NULL, (Datum) 0,
328 : INDEX_CREATE_IS_PRIMARY, 0, true, true, NULL);
329 :
330 9018 : table_close(toast_rel, NoLock);
331 :
332 : /*
333 : * Store the toast table's OID in the parent relation's pg_class row
334 : */
335 9018 : class_rel = table_open(RelationRelationId, RowExclusiveLock);
336 :
337 9018 : if (!IsBootstrapProcessingMode())
338 : {
339 : /* normal case, use a transactional update */
340 7233 : reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
341 7233 : if (!HeapTupleIsValid(reltup))
342 0 : elog(ERROR, "cache lookup failed for relation %u", relOid);
343 :
344 7233 : ((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
345 :
346 7233 : CatalogTupleUpdate(class_rel, &reltup->t_self, reltup);
347 : }
348 : else
349 : {
350 : /* While bootstrapping, we cannot UPDATE, so overwrite in-place */
351 :
352 : ScanKeyData key[1];
353 : void *state;
354 :
355 1785 : ScanKeyInit(&key[0],
356 : Anum_pg_class_oid,
357 : BTEqualStrategyNumber, F_OIDEQ,
358 : ObjectIdGetDatum(relOid));
359 1785 : systable_inplace_update_begin(class_rel, ClassOidIndexId, true,
360 : NULL, 1, key, &reltup, &state);
361 1785 : if (!HeapTupleIsValid(reltup))
362 0 : elog(ERROR, "cache lookup failed for relation %u", relOid);
363 :
364 1785 : ((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
365 :
366 1785 : systable_inplace_update_finish(state, reltup);
367 : }
368 :
369 9018 : heap_freetuple(reltup);
370 :
371 9018 : table_close(class_rel, RowExclusiveLock);
372 :
373 : /*
374 : * Register dependency from the toast table to the main, so that the toast
375 : * table will be deleted if the main is. Skip this in bootstrap mode.
376 : */
377 9018 : if (!IsBootstrapProcessingMode())
378 : {
379 7233 : baseobject.classId = RelationRelationId;
380 7233 : baseobject.objectId = relOid;
381 7233 : baseobject.objectSubId = 0;
382 7233 : toastobject.classId = RelationRelationId;
383 7233 : toastobject.objectId = toast_relid;
384 7233 : toastobject.objectSubId = 0;
385 :
386 7233 : recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
387 : }
388 :
389 : /*
390 : * Make changes visible
391 : */
392 9018 : CommandCounterIncrement();
393 :
394 9018 : return true;
395 : }
396 :
397 : /*
398 : * Check to see whether the table needs a TOAST table.
399 : */
400 : static bool
401 30421 : needs_toast_table(Relation rel)
402 : {
403 : /*
404 : * No need to create a TOAST table for partitioned tables.
405 : */
406 30421 : if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
407 4644 : return false;
408 :
409 : /*
410 : * We cannot allow toasting a shared relation after initdb (because
411 : * there's no way to mark it toasted in other databases' pg_class).
412 : */
413 25777 : if (rel->rd_rel->relisshared && !IsBootstrapProcessingMode())
414 343 : return false;
415 :
416 : /*
417 : * Ignore attempts to create toast tables on catalog tables after initdb.
418 : * Which catalogs get toast tables is explicitly chosen in catalog/pg_*.h.
419 : * (We could get here via some ALTER TABLE command if the catalog doesn't
420 : * have a toast table.)
421 : */
422 25434 : if (IsCatalogRelation(rel) && !IsBootstrapProcessingMode())
423 2205 : return false;
424 :
425 : /* Otherwise, let the AM decide. */
426 23229 : return table_relation_needs_toast_table(rel);
427 : }
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