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) 1996-2023, 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/pg_type.h"
30 : #include "catalog/toasting.h"
31 : #include "miscadmin.h"
32 : #include "nodes/makefuncs.h"
33 : #include "storage/lock.h"
34 : #include "utils/builtins.h"
35 : #include "utils/rel.h"
36 : #include "utils/syscache.h"
37 :
38 : static void CheckAndCreateToastTable(Oid relOid, Datum reloptions,
39 : LOCKMODE lockmode, bool check,
40 : Oid OIDOldToast);
41 : static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
42 : Datum reloptions, LOCKMODE lockmode, bool check,
43 : Oid OIDOldToast);
44 : static bool needs_toast_table(Relation rel);
45 :
46 :
47 : /*
48 : * CreateToastTable variants
49 : * If the table needs a toast table, and doesn't already have one,
50 : * then create a toast table for it.
51 : *
52 : * reloptions for the toast table can be passed, too. Pass (Datum) 0
53 : * for default reloptions.
54 : *
55 : * We expect the caller to have verified that the relation is a table and have
56 : * already done any necessary permission checks. Callers expect this function
57 : * to end with CommandCounterIncrement if it makes any changes.
58 : */
59 : void
60 81172 : AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
61 : {
62 81172 : CheckAndCreateToastTable(relOid, reloptions, lockmode, true, InvalidOid);
63 81172 : }
64 :
65 : void
66 588 : NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
67 : Oid OIDOldToast)
68 : {
69 588 : CheckAndCreateToastTable(relOid, reloptions, lockmode, false, OIDOldToast);
70 588 : }
71 :
72 : void
73 34480 : NewRelationCreateToastTable(Oid relOid, Datum reloptions)
74 : {
75 34480 : CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false,
76 : InvalidOid);
77 34480 : }
78 :
79 : static void
80 116240 : CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
81 : bool check, Oid OIDOldToast)
82 : {
83 : Relation rel;
84 :
85 116240 : rel = table_open(relOid, lockmode);
86 :
87 : /* create_toast_table does all the work */
88 116240 : (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode,
89 : check, OIDOldToast);
90 :
91 116240 : table_close(rel, NoLock);
92 116240 : }
93 :
94 : /*
95 : * Create a toast table during bootstrap
96 : *
97 : * Here we need to prespecify the OIDs of the toast table and its index
98 : */
99 : void
100 21816 : BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
101 : {
102 : Relation rel;
103 :
104 21816 : rel = table_openrv(makeRangeVar(NULL, relName, -1), AccessExclusiveLock);
105 :
106 21816 : if (rel->rd_rel->relkind != RELKIND_RELATION &&
107 0 : rel->rd_rel->relkind != RELKIND_MATVIEW)
108 0 : elog(ERROR, "\"%s\" is not a table or materialized view",
109 : relName);
110 :
111 : /* create_toast_table does all the work */
112 21816 : if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0,
113 : AccessExclusiveLock, false, InvalidOid))
114 0 : elog(ERROR, "\"%s\" does not require a toast table",
115 : relName);
116 :
117 21816 : table_close(rel, NoLock);
118 21816 : }
119 :
120 :
121 : /*
122 : * create_toast_table --- internal workhorse
123 : *
124 : * rel is already opened and locked
125 : * toastOid and toastIndexOid are normally InvalidOid, but during
126 : * bootstrap they can be nonzero to specify hand-assigned OIDs
127 : */
128 : static bool
129 138056 : create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
130 : Datum reloptions, LOCKMODE lockmode, bool check,
131 : Oid OIDOldToast)
132 : {
133 138056 : Oid relOid = RelationGetRelid(rel);
134 : HeapTuple reltup;
135 : TupleDesc tupdesc;
136 : bool shared_relation;
137 : bool mapped_relation;
138 : Relation toast_rel;
139 : Relation class_rel;
140 : Oid toast_relid;
141 : Oid namespaceid;
142 : char toast_relname[NAMEDATALEN];
143 : char toast_idxname[NAMEDATALEN];
144 : IndexInfo *indexInfo;
145 : Oid collationObjectId[2];
146 : Oid classObjectId[2];
147 : int16 coloptions[2];
148 : ObjectAddress baseobject,
149 : toastobject;
150 :
151 : /*
152 : * Is it already toasted?
153 : */
154 138056 : if (rel->rd_rel->reltoastrelid != InvalidOid)
155 40704 : return false;
156 :
157 : /*
158 : * Check to see whether the table actually needs a TOAST table.
159 : */
160 97352 : if (!IsBinaryUpgrade)
161 : {
162 : /* Normal mode, normal check */
163 94582 : if (!needs_toast_table(rel))
164 59180 : return false;
165 : }
166 : else
167 : {
168 : /*
169 : * In binary-upgrade mode, create a TOAST table if and only if
170 : * pg_upgrade told us to (ie, a TOAST table OID has been provided).
171 : *
172 : * This indicates that the old cluster had a TOAST table for the
173 : * current table. We must create a TOAST table to receive the old
174 : * TOAST file, even if the table seems not to need one.
175 : *
176 : * Contrariwise, if the old cluster did not have a TOAST table, we
177 : * should be able to get along without one even if the new version's
178 : * needs_toast_table rules suggest we should have one. There is a lot
179 : * of daylight between where we will create a TOAST table and where
180 : * one is really necessary to avoid failures, so small cross-version
181 : * differences in the when-to-create heuristic shouldn't be a problem.
182 : * If we tried to create a TOAST table anyway, we would have the
183 : * problem that it might take up an OID that will conflict with some
184 : * old-cluster table we haven't seen yet.
185 : */
186 2770 : if (!OidIsValid(binary_upgrade_next_toast_pg_class_oid))
187 2282 : return false;
188 : }
189 :
190 : /*
191 : * If requested check lockmode is sufficient. This is a cross check in
192 : * case of errors or conflicting decisions in earlier code.
193 : */
194 35890 : if (check && lockmode != AccessExclusiveLock)
195 0 : elog(ERROR, "AccessExclusiveLock required to add toast table.");
196 :
197 : /*
198 : * Create the toast table and its index
199 : */
200 35890 : snprintf(toast_relname, sizeof(toast_relname),
201 : "pg_toast_%u", relOid);
202 35890 : snprintf(toast_idxname, sizeof(toast_idxname),
203 : "pg_toast_%u_index", relOid);
204 :
205 : /* this is pretty painful... need a tuple descriptor */
206 35890 : tupdesc = CreateTemplateTupleDesc(3);
207 35890 : TupleDescInitEntry(tupdesc, (AttrNumber) 1,
208 : "chunk_id",
209 : OIDOID,
210 : -1, 0);
211 35890 : TupleDescInitEntry(tupdesc, (AttrNumber) 2,
212 : "chunk_seq",
213 : INT4OID,
214 : -1, 0);
215 35890 : TupleDescInitEntry(tupdesc, (AttrNumber) 3,
216 : "chunk_data",
217 : BYTEAOID,
218 : -1, 0);
219 :
220 : /*
221 : * Ensure that the toast table doesn't itself get toasted, or we'll be
222 : * toast :-(. This is essential for chunk_data because type bytea is
223 : * toastable; hit the other two just to be sure.
224 : */
225 35890 : TupleDescAttr(tupdesc, 0)->attstorage = TYPSTORAGE_PLAIN;
226 35890 : TupleDescAttr(tupdesc, 1)->attstorage = TYPSTORAGE_PLAIN;
227 35890 : TupleDescAttr(tupdesc, 2)->attstorage = TYPSTORAGE_PLAIN;
228 :
229 : /* Toast field should not be compressed */
230 35890 : TupleDescAttr(tupdesc, 0)->attcompression = InvalidCompressionMethod;
231 35890 : TupleDescAttr(tupdesc, 1)->attcompression = InvalidCompressionMethod;
232 35890 : TupleDescAttr(tupdesc, 2)->attcompression = InvalidCompressionMethod;
233 :
234 : /*
235 : * Toast tables for regular relations go in pg_toast; those for temp
236 : * relations go into the per-backend temp-toast-table namespace.
237 : */
238 35890 : if (isTempOrTempToastNamespace(rel->rd_rel->relnamespace))
239 860 : namespaceid = GetTempToastNamespace();
240 : else
241 35030 : namespaceid = PG_TOAST_NAMESPACE;
242 :
243 : /* Toast table is shared if and only if its parent is. */
244 35890 : shared_relation = rel->rd_rel->relisshared;
245 :
246 : /* It's mapped if and only if its parent is, too */
247 35890 : mapped_relation = RelationIsMapped(rel);
248 :
249 71780 : toast_relid = heap_create_with_catalog(toast_relname,
250 : namespaceid,
251 35890 : rel->rd_rel->reltablespace,
252 : toastOid,
253 : InvalidOid,
254 : InvalidOid,
255 35890 : rel->rd_rel->relowner,
256 : table_relation_toast_am(rel),
257 : tupdesc,
258 : NIL,
259 : RELKIND_TOASTVALUE,
260 35890 : rel->rd_rel->relpersistence,
261 : shared_relation,
262 : mapped_relation,
263 : ONCOMMIT_NOOP,
264 : reloptions,
265 : false,
266 : true,
267 : true,
268 : OIDOldToast,
269 : NULL);
270 : Assert(toast_relid != InvalidOid);
271 :
272 : /* make the toast relation visible, else table_open will fail */
273 35890 : CommandCounterIncrement();
274 :
275 : /* ShareLock is not really needed here, but take it anyway */
276 35890 : toast_rel = table_open(toast_relid, ShareLock);
277 :
278 : /*
279 : * Create unique index on chunk_id, chunk_seq.
280 : *
281 : * NOTE: the normal TOAST access routines could actually function with a
282 : * single-column index on chunk_id only. However, the slice access
283 : * routines use both columns for faster access to an individual chunk. In
284 : * addition, we want it to be unique as a check against the possibility of
285 : * duplicate TOAST chunk OIDs. The index might also be a little more
286 : * efficient this way, since btree isn't all that happy with large numbers
287 : * of equal keys.
288 : */
289 :
290 35890 : indexInfo = makeNode(IndexInfo);
291 35890 : indexInfo->ii_NumIndexAttrs = 2;
292 35890 : indexInfo->ii_NumIndexKeyAttrs = 2;
293 35890 : indexInfo->ii_IndexAttrNumbers[0] = 1;
294 35890 : indexInfo->ii_IndexAttrNumbers[1] = 2;
295 35890 : indexInfo->ii_Expressions = NIL;
296 35890 : indexInfo->ii_ExpressionsState = NIL;
297 35890 : indexInfo->ii_Predicate = NIL;
298 35890 : indexInfo->ii_PredicateState = NULL;
299 35890 : indexInfo->ii_ExclusionOps = NULL;
300 35890 : indexInfo->ii_ExclusionProcs = NULL;
301 35890 : indexInfo->ii_ExclusionStrats = NULL;
302 35890 : indexInfo->ii_OpclassOptions = NULL;
303 35890 : indexInfo->ii_Unique = true;
304 35890 : indexInfo->ii_NullsNotDistinct = false;
305 35890 : indexInfo->ii_ReadyForInserts = true;
306 35890 : indexInfo->ii_CheckedUnchanged = false;
307 35890 : indexInfo->ii_IndexUnchanged = false;
308 35890 : indexInfo->ii_Concurrent = false;
309 35890 : indexInfo->ii_BrokenHotChain = false;
310 35890 : indexInfo->ii_ParallelWorkers = 0;
311 35890 : indexInfo->ii_Am = BTREE_AM_OID;
312 35890 : indexInfo->ii_AmCache = NULL;
313 35890 : indexInfo->ii_Context = CurrentMemoryContext;
314 :
315 35890 : collationObjectId[0] = InvalidOid;
316 35890 : collationObjectId[1] = InvalidOid;
317 :
318 35890 : classObjectId[0] = OID_BTREE_OPS_OID;
319 35890 : classObjectId[1] = INT4_BTREE_OPS_OID;
320 :
321 35890 : coloptions[0] = 0;
322 35890 : coloptions[1] = 0;
323 :
324 35890 : index_create(toast_rel, toast_idxname, toastIndexOid, InvalidOid,
325 : InvalidOid, InvalidOid,
326 : indexInfo,
327 35890 : list_make2("chunk_id", "chunk_seq"),
328 : BTREE_AM_OID,
329 35890 : rel->rd_rel->reltablespace,
330 : collationObjectId, classObjectId, coloptions, (Datum) 0,
331 : INDEX_CREATE_IS_PRIMARY, 0, true, true, NULL);
332 :
333 35890 : table_close(toast_rel, NoLock);
334 :
335 : /*
336 : * Store the toast table's OID in the parent relation's pg_class row
337 : */
338 35890 : class_rel = table_open(RelationRelationId, RowExclusiveLock);
339 :
340 35890 : reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
341 35890 : if (!HeapTupleIsValid(reltup))
342 0 : elog(ERROR, "cache lookup failed for relation %u", relOid);
343 :
344 35890 : ((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
345 :
346 35890 : if (!IsBootstrapProcessingMode())
347 : {
348 : /* normal case, use a transactional update */
349 14074 : CatalogTupleUpdate(class_rel, &reltup->t_self, reltup);
350 : }
351 : else
352 : {
353 : /* While bootstrapping, we cannot UPDATE, so overwrite in-place */
354 21816 : heap_inplace_update(class_rel, reltup);
355 : }
356 :
357 35890 : heap_freetuple(reltup);
358 :
359 35890 : table_close(class_rel, RowExclusiveLock);
360 :
361 : /*
362 : * Register dependency from the toast table to the main, so that the toast
363 : * table will be deleted if the main is. Skip this in bootstrap mode.
364 : */
365 35890 : if (!IsBootstrapProcessingMode())
366 : {
367 14074 : baseobject.classId = RelationRelationId;
368 14074 : baseobject.objectId = relOid;
369 14074 : baseobject.objectSubId = 0;
370 14074 : toastobject.classId = RelationRelationId;
371 14074 : toastobject.objectId = toast_relid;
372 14074 : toastobject.objectSubId = 0;
373 :
374 14074 : recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
375 : }
376 :
377 : /*
378 : * Make changes visible
379 : */
380 35890 : CommandCounterIncrement();
381 :
382 35890 : return true;
383 : }
384 :
385 : /*
386 : * Check to see whether the table needs a TOAST table.
387 : */
388 : static bool
389 94582 : needs_toast_table(Relation rel)
390 : {
391 : /*
392 : * No need to create a TOAST table for partitioned tables.
393 : */
394 94582 : if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
395 6964 : return false;
396 :
397 : /*
398 : * We cannot allow toasting a shared relation after initdb (because
399 : * there's no way to mark it toasted in other databases' pg_class).
400 : */
401 87618 : if (rel->rd_rel->relisshared && !IsBootstrapProcessingMode())
402 1806 : return false;
403 :
404 : /*
405 : * Ignore attempts to create toast tables on catalog tables after initdb.
406 : * Which catalogs get toast tables is explicitly chosen in catalog/pg_*.h.
407 : * (We could get here via some ALTER TABLE command if the catalog doesn't
408 : * have a toast table.)
409 : */
410 85812 : if (IsCatalogRelation(rel) && !IsBootstrapProcessingMode())
411 27692 : return false;
412 :
413 : /* Otherwise, let the AM decide. */
414 58120 : return table_relation_needs_toast_table(rel);
415 : }
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