1/*-------------------------------------------------------------------------
2 *
3 * namespace.c
4 * code to support accessing and searching namespaces
5 *
6 * This is separate from pg_namespace.c, which contains the routines that
7 * directly manipulate the pg_namespace system catalog. This module
8 * provides routines associated with defining a "namespace search path"
9 * and implementing search-path-controlled searches.
10 *
11 *
12 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
14 *
15 * IDENTIFICATION
16 * src/backend/catalog/namespace.c
17 *
18 *-------------------------------------------------------------------------
19 */
20#include "postgres.h"
21
22#include "access/htup_details.h"
23#include "access/parallel.h"
24#include "access/xact.h"
25#include "access/xlog.h"
26#include "catalog/dependency.h"
27#include "catalog/objectaccess.h"
28#include "catalog/pg_authid.h"
29#include "catalog/pg_collation.h"
30#include "catalog/pg_conversion.h"
31#include "catalog/pg_namespace.h"
32#include "catalog/pg_opclass.h"
33#include "catalog/pg_operator.h"
34#include "catalog/pg_opfamily.h"
35#include "catalog/pg_proc.h"
36#include "catalog/pg_statistic_ext.h"
37#include "catalog/pg_ts_config.h"
38#include "catalog/pg_ts_dict.h"
39#include "catalog/pg_ts_parser.h"
40#include "catalog/pg_ts_template.h"
41#include "catalog/pg_type.h"
42#include "commands/dbcommands.h"
43#include "funcapi.h"
44#include "mb/pg_wchar.h"
45#include "miscadmin.h"
46#include "nodes/makefuncs.h"
47#include "parser/parse_func.h"
48#include "storage/ipc.h"
49#include "storage/lmgr.h"
50#include "storage/sinvaladt.h"
51#include "utils/acl.h"
52#include "utils/builtins.h"
53#include "utils/catcache.h"
54#include "utils/guc.h"
55#include "utils/inval.h"
56#include "utils/lsyscache.h"
57#include "utils/memutils.h"
58#include "utils/syscache.h"
59#include "utils/varlena.h"
60
61
62/*
63 * The namespace search path is a possibly-empty list of namespace OIDs.
64 * In addition to the explicit list, implicitly-searched namespaces
65 * may be included:
66 *
67 * 1. If a TEMP table namespace has been initialized in this session, it
68 * is implicitly searched first. (The only time this doesn't happen is
69 * when we are obeying an override search path spec that says not to use the
70 * temp namespace, or the temp namespace is included in the explicit list.)
71 *
72 * 2. The system catalog namespace is always searched. If the system
73 * namespace is present in the explicit path then it will be searched in
74 * the specified order; otherwise it will be searched after TEMP tables and
75 * *before* the explicit list. (It might seem that the system namespace
76 * should be implicitly last, but this behavior appears to be required by
77 * SQL99. Also, this provides a way to search the system namespace first
78 * without thereby making it the default creation target namespace.)
79 *
80 * For security reasons, searches using the search path will ignore the temp
81 * namespace when searching for any object type other than relations and
82 * types. (We must allow types since temp tables have rowtypes.)
83 *
84 * The default creation target namespace is always the first element of the
85 * explicit list. If the explicit list is empty, there is no default target.
86 *
87 * The textual specification of search_path can include "$user" to refer to
88 * the namespace named the same as the current user, if any. (This is just
89 * ignored if there is no such namespace.) Also, it can include "pg_temp"
90 * to refer to the current backend's temp namespace. This is usually also
91 * ignorable if the temp namespace hasn't been set up, but there's a special
92 * case: if "pg_temp" appears first then it should be the default creation
93 * target. We kluge this case a little bit so that the temp namespace isn't
94 * set up until the first attempt to create something in it. (The reason for
95 * klugery is that we can't create the temp namespace outside a transaction,
96 * but initial GUC processing of search_path happens outside a transaction.)
97 * activeTempCreationPending is true if "pg_temp" appears first in the string
98 * but is not reflected in activeCreationNamespace because the namespace isn't
99 * set up yet.
100 *
101 * In bootstrap mode, the search path is set equal to "pg_catalog", so that
102 * the system namespace is the only one searched or inserted into.
103 * initdb is also careful to set search_path to "pg_catalog" for its
104 * post-bootstrap standalone backend runs. Otherwise the default search
105 * path is determined by GUC. The factory default path contains the PUBLIC
106 * namespace (if it exists), preceded by the user's personal namespace
107 * (if one exists).
108 *
109 * We support a stack of "override" search path settings for use within
110 * specific sections of backend code. namespace_search_path is ignored
111 * whenever the override stack is nonempty. activeSearchPath is always
112 * the actually active path; it points either to the search list of the
113 * topmost stack entry, or to baseSearchPath which is the list derived
114 * from namespace_search_path.
115 *
116 * If baseSearchPathValid is false, then baseSearchPath (and other
117 * derived variables) need to be recomputed from namespace_search_path.
118 * We mark it invalid upon an assignment to namespace_search_path or receipt
119 * of a syscache invalidation event for pg_namespace. The recomputation
120 * is done during the next non-overridden lookup attempt. Note that an
121 * override spec is never subject to recomputation.
122 *
123 * Any namespaces mentioned in namespace_search_path that are not readable
124 * by the current user ID are simply left out of baseSearchPath; so
125 * we have to be willing to recompute the path when current userid changes.
126 * namespaceUser is the userid the path has been computed for.
127 *
128 * Note: all data pointed to by these List variables is in TopMemoryContext.
129 */
130
131/* These variables define the actually active state: */
132
133static List *activeSearchPath = NIL;
134
135/* default place to create stuff; if InvalidOid, no default */
136static Oid activeCreationNamespace = InvalidOid;
137
138/* if true, activeCreationNamespace is wrong, it should be temp namespace */
139static bool activeTempCreationPending = false;
140
141/* These variables are the values last derived from namespace_search_path: */
142
143static List *baseSearchPath = NIL;
144
145static Oid baseCreationNamespace = InvalidOid;
146
147static bool baseTempCreationPending = false;
148
149static Oid namespaceUser = InvalidOid;
150
151/* The above four values are valid only if baseSearchPathValid */
152static bool baseSearchPathValid = true;
153
154/* Override requests are remembered in a stack of OverrideStackEntry structs */
155
156typedef struct
157{
158 List *searchPath; /* the desired search path */
159 Oid creationNamespace; /* the desired creation namespace */
160 int nestLevel; /* subtransaction nesting level */
161} OverrideStackEntry;
162
163static List *overrideStack = NIL;
164
165/*
166 * myTempNamespace is InvalidOid until and unless a TEMP namespace is set up
167 * in a particular backend session (this happens when a CREATE TEMP TABLE
168 * command is first executed). Thereafter it's the OID of the temp namespace.
169 *
170 * myTempToastNamespace is the OID of the namespace for my temp tables' toast
171 * tables. It is set when myTempNamespace is, and is InvalidOid before that.
172 *
173 * myTempNamespaceSubID shows whether we've created the TEMP namespace in the
174 * current subtransaction. The flag propagates up the subtransaction tree,
175 * so the main transaction will correctly recognize the flag if all
176 * intermediate subtransactions commit. When it is InvalidSubTransactionId,
177 * we either haven't made the TEMP namespace yet, or have successfully
178 * committed its creation, depending on whether myTempNamespace is valid.
179 */
180static Oid myTempNamespace = InvalidOid;
181
182static Oid myTempToastNamespace = InvalidOid;
183
184static SubTransactionId myTempNamespaceSubID = InvalidSubTransactionId;
185
186/*
187 * This is the user's textual search path specification --- it's the value
188 * of the GUC variable 'search_path'.
189 */
190char *namespace_search_path = NULL;
191
192
193/* Local functions */
194static void recomputeNamespacePath(void);
195static void AccessTempTableNamespace(bool force);
196static void InitTempTableNamespace(void);
197static void RemoveTempRelations(Oid tempNamespaceId);
198static void RemoveTempRelationsCallback(int code, Datum arg);
199static void NamespaceCallback(Datum arg, int cacheid, uint32 hashvalue);
200static bool MatchNamedCall(HeapTuple proctup, int nargs, List *argnames,
201 int **argnumbers);
202
203
204/*
205 * RangeVarGetRelidExtended
206 * Given a RangeVar describing an existing relation,
207 * select the proper namespace and look up the relation OID.
208 *
209 * If the schema or relation is not found, return InvalidOid if flags contains
210 * RVR_MISSING_OK, otherwise raise an error.
211 *
212 * If flags contains RVR_NOWAIT, throw an error if we'd have to wait for a
213 * lock.
214 *
215 * If flags contains RVR_SKIP_LOCKED, return InvalidOid if we'd have to wait
216 * for a lock.
217 *
218 * flags cannot contain both RVR_NOWAIT and RVR_SKIP_LOCKED.
219 *
220 * Note that if RVR_MISSING_OK and RVR_SKIP_LOCKED are both specified, a
221 * return value of InvalidOid could either mean the relation is missing or it
222 * could not be locked.
223 *
224 * Callback allows caller to check permissions or acquire additional locks
225 * prior to grabbing the relation lock.
226 */
227Oid
228RangeVarGetRelidExtended(const RangeVar *relation, LOCKMODE lockmode,
229 uint32 flags,
230 RangeVarGetRelidCallback callback, void *callback_arg)
231{
232 uint64 inval_count;
233 Oid relId;
234 Oid oldRelId = InvalidOid;
235 bool retry = false;
236 bool missing_ok = (flags & RVR_MISSING_OK) != 0;
237
238 /* verify that flags do no conflict */
239 Assert(!((flags & RVR_NOWAIT) && (flags & RVR_SKIP_LOCKED)));
240
241 /*
242 * We check the catalog name and then ignore it.
243 */
244 if (relation->catalogname)
245 {
246 if (strcmp(relation->catalogname, get_database_name(MyDatabaseId)) != 0)
247 ereport(ERROR,
248 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
249 errmsg("cross-database references are not implemented: \"%s.%s.%s\"",
250 relation->catalogname, relation->schemaname,
251 relation->relname)));
252 }
253
254 /*
255 * DDL operations can change the results of a name lookup. Since all such
256 * operations will generate invalidation messages, we keep track of
257 * whether any such messages show up while we're performing the operation,
258 * and retry until either (1) no more invalidation messages show up or (2)
259 * the answer doesn't change.
260 *
261 * But if lockmode = NoLock, then we assume that either the caller is OK
262 * with the answer changing under them, or that they already hold some
263 * appropriate lock, and therefore return the first answer we get without
264 * checking for invalidation messages. Also, if the requested lock is
265 * already held, LockRelationOid will not AcceptInvalidationMessages, so
266 * we may fail to notice a change. We could protect against that case by
267 * calling AcceptInvalidationMessages() before beginning this loop, but
268 * that would add a significant amount overhead, so for now we don't.
269 */
270 for (;;)
271 {
272 /*
273 * Remember this value, so that, after looking up the relation name
274 * and locking its OID, we can check whether any invalidation messages
275 * have been processed that might require a do-over.
276 */
277 inval_count = SharedInvalidMessageCounter;
278
279 /*
280 * Some non-default relpersistence value may have been specified. The
281 * parser never generates such a RangeVar in simple DML, but it can
282 * happen in contexts such as "CREATE TEMP TABLE foo (f1 int PRIMARY
283 * KEY)". Such a command will generate an added CREATE INDEX
284 * operation, which must be careful to find the temp table, even when
285 * pg_temp is not first in the search path.
286 */
287 if (relation->relpersistence == RELPERSISTENCE_TEMP)
288 {
289 if (!OidIsValid(myTempNamespace))
290 relId = InvalidOid; /* this probably can't happen? */
291 else
292 {
293 if (relation->schemaname)
294 {
295 Oid namespaceId;
296
297 namespaceId = LookupExplicitNamespace(relation->schemaname, missing_ok);
298
299 /*
300 * For missing_ok, allow a non-existent schema name to
301 * return InvalidOid.
302 */
303 if (namespaceId != myTempNamespace)
304 ereport(ERROR,
305 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
306 errmsg("temporary tables cannot specify a schema name")));
307 }
308
309 relId = get_relname_relid(relation->relname, myTempNamespace);
310 }
311 }
312 else if (relation->schemaname)
313 {
314 Oid namespaceId;
315
316 /* use exact schema given */
317 namespaceId = LookupExplicitNamespace(relation->schemaname, missing_ok);
318 if (missing_ok && !OidIsValid(namespaceId))
319 relId = InvalidOid;
320 else
321 relId = get_relname_relid(relation->relname, namespaceId);
322 }
323 else
324 {
325 /* search the namespace path */
326 relId = RelnameGetRelid(relation->relname);
327 }
328
329 /*
330 * Invoke caller-supplied callback, if any.
331 *
332 * This callback is a good place to check permissions: we haven't
333 * taken the table lock yet (and it's really best to check permissions
334 * before locking anything!), but we've gotten far enough to know what
335 * OID we think we should lock. Of course, concurrent DDL might
336 * change things while we're waiting for the lock, but in that case
337 * the callback will be invoked again for the new OID.
338 */
339 if (callback)
340 callback(relation, relId, oldRelId, callback_arg);
341
342 /*
343 * If no lock requested, we assume the caller knows what they're
344 * doing. They should have already acquired a heavyweight lock on
345 * this relation earlier in the processing of this same statement, so
346 * it wouldn't be appropriate to AcceptInvalidationMessages() here, as
347 * that might pull the rug out from under them.
348 */
349 if (lockmode == NoLock)
350 break;
351
352 /*
353 * If, upon retry, we get back the same OID we did last time, then the
354 * invalidation messages we processed did not change the final answer.
355 * So we're done.
356 *
357 * If we got a different OID, we've locked the relation that used to
358 * have this name rather than the one that does now. So release the
359 * lock.
360 */
361 if (retry)
362 {
363 if (relId == oldRelId)
364 break;
365 if (OidIsValid(oldRelId))
366 UnlockRelationOid(oldRelId, lockmode);
367 }
368
369 /*
370 * Lock relation. This will also accept any pending invalidation
371 * messages. If we got back InvalidOid, indicating not found, then
372 * there's nothing to lock, but we accept invalidation messages
373 * anyway, to flush any negative catcache entries that may be
374 * lingering.
375 */
376 if (!OidIsValid(relId))
377 AcceptInvalidationMessages();
378 else if (!(flags & (RVR_NOWAIT | RVR_SKIP_LOCKED)))
379 LockRelationOid(relId, lockmode);
380 else if (!ConditionalLockRelationOid(relId, lockmode))
381 {
382 int elevel = (flags & RVR_SKIP_LOCKED) ? DEBUG1 : ERROR;
383
384 if (relation->schemaname)
385 ereport(elevel,
386 (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
387 errmsg("could not obtain lock on relation \"%s.%s\"",
388 relation->schemaname, relation->relname)));
389 else
390 ereport(elevel,
391 (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
392 errmsg("could not obtain lock on relation \"%s\"",
393 relation->relname)));
394
395 return InvalidOid;
396 }
397
398 /*
399 * If no invalidation message were processed, we're done!
400 */
401 if (inval_count == SharedInvalidMessageCounter)
402 break;
403
404 /*
405 * Something may have changed. Let's repeat the name lookup, to make
406 * sure this name still references the same relation it did
407 * previously.
408 */
409 retry = true;
410 oldRelId = relId;
411 }
412
413 if (!OidIsValid(relId))
414 {
415 int elevel = missing_ok ? DEBUG1 : ERROR;
416
417 if (relation->schemaname)
418 ereport(elevel,
419 (errcode(ERRCODE_UNDEFINED_TABLE),
420 errmsg("relation \"%s.%s\" does not exist",
421 relation->schemaname, relation->relname)));
422 else
423 ereport(elevel,
424 (errcode(ERRCODE_UNDEFINED_TABLE),
425 errmsg("relation \"%s\" does not exist",
426 relation->relname)));
427 }
428 return relId;
429}
430
431/*
432 * RangeVarGetCreationNamespace
433 * Given a RangeVar describing a to-be-created relation,
434 * choose which namespace to create it in.
435 *
436 * Note: calling this may result in a CommandCounterIncrement operation.
437 * That will happen on the first request for a temp table in any particular
438 * backend run; we will need to either create or clean out the temp schema.
439 */
440Oid
441RangeVarGetCreationNamespace(const RangeVar *newRelation)
442{
443 Oid namespaceId;
444
445 /*
446 * We check the catalog name and then ignore it.
447 */
448 if (newRelation->catalogname)
449 {
450 if (strcmp(newRelation->catalogname, get_database_name(MyDatabaseId)) != 0)
451 ereport(ERROR,
452 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
453 errmsg("cross-database references are not implemented: \"%s.%s.%s\"",
454 newRelation->catalogname, newRelation->schemaname,
455 newRelation->relname)));
456 }
457
458 if (newRelation->schemaname)
459 {
460 /* check for pg_temp alias */
461 if (strcmp(newRelation->schemaname, "pg_temp") == 0)
462 {
463 /* Initialize temp namespace */
464 AccessTempTableNamespace(false);
465 return myTempNamespace;
466 }
467 /* use exact schema given */
468 namespaceId = get_namespace_oid(newRelation->schemaname, false);
469 /* we do not check for USAGE rights here! */
470 }
471 else if (newRelation->relpersistence == RELPERSISTENCE_TEMP)
472 {
473 /* Initialize temp namespace */
474 AccessTempTableNamespace(false);
475 return myTempNamespace;
476 }
477 else
478 {
479 /* use the default creation namespace */
480 recomputeNamespacePath();
481 if (activeTempCreationPending)
482 {
483 /* Need to initialize temp namespace */
484 AccessTempTableNamespace(true);
485 return myTempNamespace;
486 }
487 namespaceId = activeCreationNamespace;
488 if (!OidIsValid(namespaceId))
489 ereport(ERROR,
490 (errcode(ERRCODE_UNDEFINED_SCHEMA),
491 errmsg("no schema has been selected to create in")));
492 }
493
494 /* Note: callers will check for CREATE rights when appropriate */
495
496 return namespaceId;
497}
498
499/*
500 * RangeVarGetAndCheckCreationNamespace
501 *
502 * This function returns the OID of the namespace in which a new relation
503 * with a given name should be created. If the user does not have CREATE
504 * permission on the target namespace, this function will instead signal
505 * an ERROR.
506 *
507 * If non-NULL, *existing_oid is set to the OID of any existing relation with
508 * the same name which already exists in that namespace, or to InvalidOid if
509 * no such relation exists.
510 *
511 * If lockmode != NoLock, the specified lock mode is acquired on the existing
512 * relation, if any, provided that the current user owns the target relation.
513 * However, if lockmode != NoLock and the user does not own the target
514 * relation, we throw an ERROR, as we must not try to lock relations the
515 * user does not have permissions on.
516 *
517 * As a side effect, this function acquires AccessShareLock on the target
518 * namespace. Without this, the namespace could be dropped before our
519 * transaction commits, leaving behind relations with relnamespace pointing
520 * to a no-longer-existent namespace.
521 *
522 * As a further side-effect, if the selected namespace is a temporary namespace,
523 * we mark the RangeVar as RELPERSISTENCE_TEMP.
524 */
525Oid
526RangeVarGetAndCheckCreationNamespace(RangeVar *relation,
527 LOCKMODE lockmode,
528 Oid *existing_relation_id)
529{
530 uint64 inval_count;
531 Oid relid;
532 Oid oldrelid = InvalidOid;
533 Oid nspid;
534 Oid oldnspid = InvalidOid;
535 bool retry = false;
536
537 /*
538 * We check the catalog name and then ignore it.
539 */
540 if (relation->catalogname)
541 {
542 if (strcmp(relation->catalogname, get_database_name(MyDatabaseId)) != 0)
543 ereport(ERROR,
544 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
545 errmsg("cross-database references are not implemented: \"%s.%s.%s\"",
546 relation->catalogname, relation->schemaname,
547 relation->relname)));
548 }
549
550 /*
551 * As in RangeVarGetRelidExtended(), we guard against concurrent DDL
552 * operations by tracking whether any invalidation messages are processed
553 * while we're doing the name lookups and acquiring locks. See comments
554 * in that function for a more detailed explanation of this logic.
555 */
556 for (;;)
557 {
558 AclResult aclresult;
559
560 inval_count = SharedInvalidMessageCounter;
561
562 /* Look up creation namespace and check for existing relation. */
563 nspid = RangeVarGetCreationNamespace(relation);
564 Assert(OidIsValid(nspid));
565 if (existing_relation_id != NULL)
566 relid = get_relname_relid(relation->relname, nspid);
567 else
568 relid = InvalidOid;
569
570 /*
571 * In bootstrap processing mode, we don't bother with permissions or
572 * locking. Permissions might not be working yet, and locking is
573 * unnecessary.
574 */
575 if (IsBootstrapProcessingMode())
576 break;
577
578 /* Check namespace permissions. */
579 aclresult = pg_namespace_aclcheck(nspid, GetUserId(), ACL_CREATE);
580 if (aclresult != ACLCHECK_OK)
581 aclcheck_error(aclresult, OBJECT_SCHEMA,
582 get_namespace_name(nspid));
583
584 if (retry)
585 {
586 /* If nothing changed, we're done. */
587 if (relid == oldrelid && nspid == oldnspid)
588 break;
589 /* If creation namespace has changed, give up old lock. */
590 if (nspid != oldnspid)
591 UnlockDatabaseObject(NamespaceRelationId, oldnspid, 0,
592 AccessShareLock);
593 /* If name points to something different, give up old lock. */
594 if (relid != oldrelid && OidIsValid(oldrelid) && lockmode != NoLock)
595 UnlockRelationOid(oldrelid, lockmode);
596 }
597
598 /* Lock namespace. */
599 if (nspid != oldnspid)
600 LockDatabaseObject(NamespaceRelationId, nspid, 0, AccessShareLock);
601
602 /* Lock relation, if required if and we have permission. */
603 if (lockmode != NoLock && OidIsValid(relid))
604 {
605 if (!pg_class_ownercheck(relid, GetUserId()))
606 aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)),
607 relation->relname);
608 if (relid != oldrelid)
609 LockRelationOid(relid, lockmode);
610 }
611
612 /* If no invalidation message were processed, we're done! */
613 if (inval_count == SharedInvalidMessageCounter)
614 break;
615
616 /* Something may have changed, so recheck our work. */
617 retry = true;
618 oldrelid = relid;
619 oldnspid = nspid;
620 }
621
622 RangeVarAdjustRelationPersistence(relation, nspid);
623 if (existing_relation_id != NULL)
624 *existing_relation_id = relid;
625 return nspid;
626}
627
628/*
629 * Adjust the relpersistence for an about-to-be-created relation based on the
630 * creation namespace, and throw an error for invalid combinations.
631 */
632void
633RangeVarAdjustRelationPersistence(RangeVar *newRelation, Oid nspid)
634{
635 switch (newRelation->relpersistence)
636 {
637 case RELPERSISTENCE_TEMP:
638 if (!isTempOrTempToastNamespace(nspid))
639 {
640 if (isAnyTempNamespace(nspid))
641 ereport(ERROR,
642 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
643 errmsg("cannot create relations in temporary schemas of other sessions")));
644 else
645 ereport(ERROR,
646 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
647 errmsg("cannot create temporary relation in non-temporary schema")));
648 }
649 break;
650 case RELPERSISTENCE_PERMANENT:
651 if (isTempOrTempToastNamespace(nspid))
652 newRelation->relpersistence = RELPERSISTENCE_TEMP;
653 else if (isAnyTempNamespace(nspid))
654 ereport(ERROR,
655 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
656 errmsg("cannot create relations in temporary schemas of other sessions")));
657 break;
658 default:
659 if (isAnyTempNamespace(nspid))
660 ereport(ERROR,
661 (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
662 errmsg("only temporary relations may be created in temporary schemas")));
663 }
664}
665
666/*
667 * RelnameGetRelid
668 * Try to resolve an unqualified relation name.
669 * Returns OID if relation found in search path, else InvalidOid.
670 */
671Oid
672RelnameGetRelid(const char *relname)
673{
674 Oid relid;
675 ListCell *l;
676
677 recomputeNamespacePath();
678
679 foreach(l, activeSearchPath)
680 {
681 Oid namespaceId = lfirst_oid(l);
682
683 relid = get_relname_relid(relname, namespaceId);
684 if (OidIsValid(relid))
685 return relid;
686 }
687
688 /* Not found in path */
689 return InvalidOid;
690}
691
692
693/*
694 * RelationIsVisible
695 * Determine whether a relation (identified by OID) is visible in the
696 * current search path. Visible means "would be found by searching
697 * for the unqualified relation name".
698 */
699bool
700RelationIsVisible(Oid relid)
701{
702 HeapTuple reltup;
703 Form_pg_class relform;
704 Oid relnamespace;
705 bool visible;
706
707 reltup = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
708 if (!HeapTupleIsValid(reltup))
709 elog(ERROR, "cache lookup failed for relation %u", relid);
710 relform = (Form_pg_class) GETSTRUCT(reltup);
711
712 recomputeNamespacePath();
713
714 /*
715 * Quick check: if it ain't in the path at all, it ain't visible. Items in
716 * the system namespace are surely in the path and so we needn't even do
717 * list_member_oid() for them.
718 */
719 relnamespace = relform->relnamespace;
720 if (relnamespace != PG_CATALOG_NAMESPACE &&
721 !list_member_oid(activeSearchPath, relnamespace))
722 visible = false;
723 else
724 {
725 /*
726 * If it is in the path, it might still not be visible; it could be
727 * hidden by another relation of the same name earlier in the path. So
728 * we must do a slow check for conflicting relations.
729 */
730 char *relname = NameStr(relform->relname);
731 ListCell *l;
732
733 visible = false;
734 foreach(l, activeSearchPath)
735 {
736 Oid namespaceId = lfirst_oid(l);
737
738 if (namespaceId == relnamespace)
739 {
740 /* Found it first in path */
741 visible = true;
742 break;
743 }
744 if (OidIsValid(get_relname_relid(relname, namespaceId)))
745 {
746 /* Found something else first in path */
747 break;
748 }
749 }
750 }
751
752 ReleaseSysCache(reltup);
753
754 return visible;
755}
756
757
758/*
759 * TypenameGetTypid
760 * Wrapper for binary compatibility.
761 */
762Oid
763TypenameGetTypid(const char *typname)
764{
765 return TypenameGetTypidExtended(typname, true);
766}
767
768/*
769 * TypenameGetTypidExtended
770 * Try to resolve an unqualified datatype name.
771 * Returns OID if type found in search path, else InvalidOid.
772 *
773 * This is essentially the same as RelnameGetRelid.
774 */
775Oid
776TypenameGetTypidExtended(const char *typname, bool temp_ok)
777{
778 Oid typid;
779 ListCell *l;
780
781 recomputeNamespacePath();
782
783 foreach(l, activeSearchPath)
784 {
785 Oid namespaceId = lfirst_oid(l);
786
787 if (!temp_ok && namespaceId == myTempNamespace)
788 continue; /* do not look in temp namespace */
789
790 typid = GetSysCacheOid2(TYPENAMENSP, Anum_pg_type_oid,
791 PointerGetDatum(typname),
792 ObjectIdGetDatum(namespaceId));
793 if (OidIsValid(typid))
794 return typid;
795 }
796
797 /* Not found in path */
798 return InvalidOid;
799}
800
801/*
802 * TypeIsVisible
803 * Determine whether a type (identified by OID) is visible in the
804 * current search path. Visible means "would be found by searching
805 * for the unqualified type name".
806 */
807bool
808TypeIsVisible(Oid typid)
809{
810 HeapTuple typtup;
811 Form_pg_type typform;
812 Oid typnamespace;
813 bool visible;
814
815 typtup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
816 if (!HeapTupleIsValid(typtup))
817 elog(ERROR, "cache lookup failed for type %u", typid);
818 typform = (Form_pg_type) GETSTRUCT(typtup);
819
820 recomputeNamespacePath();
821
822 /*
823 * Quick check: if it ain't in the path at all, it ain't visible. Items in
824 * the system namespace are surely in the path and so we needn't even do
825 * list_member_oid() for them.
826 */
827 typnamespace = typform->typnamespace;
828 if (typnamespace != PG_CATALOG_NAMESPACE &&
829 !list_member_oid(activeSearchPath, typnamespace))
830 visible = false;
831 else
832 {
833 /*
834 * If it is in the path, it might still not be visible; it could be
835 * hidden by another type of the same name earlier in the path. So we
836 * must do a slow check for conflicting types.
837 */
838 char *typname = NameStr(typform->typname);
839 ListCell *l;
840
841 visible = false;
842 foreach(l, activeSearchPath)
843 {
844 Oid namespaceId = lfirst_oid(l);
845
846 if (namespaceId == typnamespace)
847 {
848 /* Found it first in path */
849 visible = true;
850 break;
851 }
852 if (SearchSysCacheExists2(TYPENAMENSP,
853 PointerGetDatum(typname),
854 ObjectIdGetDatum(namespaceId)))
855 {
856 /* Found something else first in path */
857 break;
858 }
859 }
860 }
861
862 ReleaseSysCache(typtup);
863
864 return visible;
865}
866
867
868/*
869 * FuncnameGetCandidates
870 * Given a possibly-qualified function name and argument count,
871 * retrieve a list of the possible matches.
872 *
873 * If nargs is -1, we return all functions matching the given name,
874 * regardless of argument count. (argnames must be NIL, and expand_variadic
875 * and expand_defaults must be false, in this case.)
876 *
877 * If argnames isn't NIL, we are considering a named- or mixed-notation call,
878 * and only functions having all the listed argument names will be returned.
879 * (We assume that length(argnames) <= nargs and all the passed-in names are
880 * distinct.) The returned structs will include an argnumbers array showing
881 * the actual argument index for each logical argument position.
882 *
883 * If expand_variadic is true, then variadic functions having the same number
884 * or fewer arguments will be retrieved, with the variadic argument and any
885 * additional argument positions filled with the variadic element type.
886 * nvargs in the returned struct is set to the number of such arguments.
887 * If expand_variadic is false, variadic arguments are not treated specially,
888 * and the returned nvargs will always be zero.
889 *
890 * If expand_defaults is true, functions that could match after insertion of
891 * default argument values will also be retrieved. In this case the returned
892 * structs could have nargs > passed-in nargs, and ndargs is set to the number
893 * of additional args (which can be retrieved from the function's
894 * proargdefaults entry).
895 *
896 * It is not possible for nvargs and ndargs to both be nonzero in the same
897 * list entry, since default insertion allows matches to functions with more
898 * than nargs arguments while the variadic transformation requires the same
899 * number or less.
900 *
901 * When argnames isn't NIL, the returned args[] type arrays are not ordered
902 * according to the functions' declarations, but rather according to the call:
903 * first any positional arguments, then the named arguments, then defaulted
904 * arguments (if needed and allowed by expand_defaults). The argnumbers[]
905 * array can be used to map this back to the catalog information.
906 * argnumbers[k] is set to the proargtypes index of the k'th call argument.
907 *
908 * We search a single namespace if the function name is qualified, else
909 * all namespaces in the search path. In the multiple-namespace case,
910 * we arrange for entries in earlier namespaces to mask identical entries in
911 * later namespaces.
912 *
913 * When expanding variadics, we arrange for non-variadic functions to mask
914 * variadic ones if the expanded argument list is the same. It is still
915 * possible for there to be conflicts between different variadic functions,
916 * however.
917 *
918 * It is guaranteed that the return list will never contain multiple entries
919 * with identical argument lists. When expand_defaults is true, the entries
920 * could have more than nargs positions, but we still guarantee that they are
921 * distinct in the first nargs positions. However, if argnames isn't NIL or
922 * either expand_variadic or expand_defaults is true, there might be multiple
923 * candidate functions that expand to identical argument lists. Rather than
924 * throw error here, we report such situations by returning a single entry
925 * with oid = 0 that represents a set of such conflicting candidates.
926 * The caller might end up discarding such an entry anyway, but if it selects
927 * such an entry it should react as though the call were ambiguous.
928 *
929 * If missing_ok is true, an empty list (NULL) is returned if the name was
930 * schema- qualified with a schema that does not exist. Likewise if no
931 * candidate is found for other reasons.
932 */
933FuncCandidateList
934FuncnameGetCandidates(List *names, int nargs, List *argnames,
935 bool expand_variadic, bool expand_defaults,
936 bool missing_ok)
937{
938 FuncCandidateList resultList = NULL;
939 bool any_special = false;
940 char *schemaname;
941 char *funcname;
942 Oid namespaceId;
943 CatCList *catlist;
944 int i;
945
946 /* check for caller error */
947 Assert(nargs >= 0 || !(expand_variadic | expand_defaults));
948
949 /* deconstruct the name list */
950 DeconstructQualifiedName(names, &schemaname, &funcname);
951
952 if (schemaname)
953 {
954 /* use exact schema given */
955 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
956 if (!OidIsValid(namespaceId))
957 return NULL;
958 }
959 else
960 {
961 /* flag to indicate we need namespace search */
962 namespaceId = InvalidOid;
963 recomputeNamespacePath();
964 }
965
966 /* Search syscache by name only */
967 catlist = SearchSysCacheList1(PROCNAMEARGSNSP, CStringGetDatum(funcname));
968
969 for (i = 0; i < catlist->n_members; i++)
970 {
971 HeapTuple proctup = &catlist->members[i]->tuple;
972 Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
973 int pronargs = procform->pronargs;
974 int effective_nargs;
975 int pathpos = 0;
976 bool variadic;
977 bool use_defaults;
978 Oid va_elem_type;
979 int *argnumbers = NULL;
980 FuncCandidateList newResult;
981
982 if (OidIsValid(namespaceId))
983 {
984 /* Consider only procs in specified namespace */
985 if (procform->pronamespace != namespaceId)
986 continue;
987 }
988 else
989 {
990 /*
991 * Consider only procs that are in the search path and are not in
992 * the temp namespace.
993 */
994 ListCell *nsp;
995
996 foreach(nsp, activeSearchPath)
997 {
998 if (procform->pronamespace == lfirst_oid(nsp) &&
999 procform->pronamespace != myTempNamespace)
1000 break;
1001 pathpos++;
1002 }
1003 if (nsp == NULL)
1004 continue; /* proc is not in search path */
1005 }
1006
1007 if (argnames != NIL)
1008 {
1009 /*
1010 * Call uses named or mixed notation
1011 *
1012 * Named or mixed notation can match a variadic function only if
1013 * expand_variadic is off; otherwise there is no way to match the
1014 * presumed-nameless parameters expanded from the variadic array.
1015 */
1016 if (OidIsValid(procform->provariadic) && expand_variadic)
1017 continue;
1018 va_elem_type = InvalidOid;
1019 variadic = false;
1020
1021 /*
1022 * Check argument count.
1023 */
1024 Assert(nargs >= 0); /* -1 not supported with argnames */
1025
1026 if (pronargs > nargs && expand_defaults)
1027 {
1028 /* Ignore if not enough default expressions */
1029 if (nargs + procform->pronargdefaults < pronargs)
1030 continue;
1031 use_defaults = true;
1032 }
1033 else
1034 use_defaults = false;
1035
1036 /* Ignore if it doesn't match requested argument count */
1037 if (pronargs != nargs && !use_defaults)
1038 continue;
1039
1040 /* Check for argument name match, generate positional mapping */
1041 if (!MatchNamedCall(proctup, nargs, argnames,
1042 &argnumbers))
1043 continue;
1044
1045 /* Named argument matching is always "special" */
1046 any_special = true;
1047 }
1048 else
1049 {
1050 /*
1051 * Call uses positional notation
1052 *
1053 * Check if function is variadic, and get variadic element type if
1054 * so. If expand_variadic is false, we should just ignore
1055 * variadic-ness.
1056 */
1057 if (pronargs <= nargs && expand_variadic)
1058 {
1059 va_elem_type = procform->provariadic;
1060 variadic = OidIsValid(va_elem_type);
1061 any_special |= variadic;
1062 }
1063 else
1064 {
1065 va_elem_type = InvalidOid;
1066 variadic = false;
1067 }
1068
1069 /*
1070 * Check if function can match by using parameter defaults.
1071 */
1072 if (pronargs > nargs && expand_defaults)
1073 {
1074 /* Ignore if not enough default expressions */
1075 if (nargs + procform->pronargdefaults < pronargs)
1076 continue;
1077 use_defaults = true;
1078 any_special = true;
1079 }
1080 else
1081 use_defaults = false;
1082
1083 /* Ignore if it doesn't match requested argument count */
1084 if (nargs >= 0 && pronargs != nargs && !variadic && !use_defaults)
1085 continue;
1086 }
1087
1088 /*
1089 * We must compute the effective argument list so that we can easily
1090 * compare it to earlier results. We waste a palloc cycle if it gets
1091 * masked by an earlier result, but really that's a pretty infrequent
1092 * case so it's not worth worrying about.
1093 */
1094 effective_nargs = Max(pronargs, nargs);
1095 newResult = (FuncCandidateList)
1096 palloc(offsetof(struct _FuncCandidateList, args) +
1097 effective_nargs * sizeof(Oid));
1098 newResult->pathpos = pathpos;
1099 newResult->oid = procform->oid;
1100 newResult->nargs = effective_nargs;
1101 newResult->argnumbers = argnumbers;
1102 if (argnumbers)
1103 {
1104 /* Re-order the argument types into call's logical order */
1105 Oid *proargtypes = procform->proargtypes.values;
1106 int i;
1107
1108 for (i = 0; i < pronargs; i++)
1109 newResult->args[i] = proargtypes[argnumbers[i]];
1110 }
1111 else
1112 {
1113 /* Simple positional case, just copy proargtypes as-is */
1114 memcpy(newResult->args, procform->proargtypes.values,
1115 pronargs * sizeof(Oid));
1116 }
1117 if (variadic)
1118 {
1119 int i;
1120
1121 newResult->nvargs = effective_nargs - pronargs + 1;
1122 /* Expand variadic argument into N copies of element type */
1123 for (i = pronargs - 1; i < effective_nargs; i++)
1124 newResult->args[i] = va_elem_type;
1125 }
1126 else
1127 newResult->nvargs = 0;
1128 newResult->ndargs = use_defaults ? pronargs - nargs : 0;
1129
1130 /*
1131 * Does it have the same arguments as something we already accepted?
1132 * If so, decide what to do to avoid returning duplicate argument
1133 * lists. We can skip this check for the single-namespace case if no
1134 * special (named, variadic or defaults) match has been made, since
1135 * then the unique index on pg_proc guarantees all the matches have
1136 * different argument lists.
1137 */
1138 if (resultList != NULL &&
1139 (any_special || !OidIsValid(namespaceId)))
1140 {
1141 /*
1142 * If we have an ordered list from SearchSysCacheList (the normal
1143 * case), then any conflicting proc must immediately adjoin this
1144 * one in the list, so we only need to look at the newest result
1145 * item. If we have an unordered list, we have to scan the whole
1146 * result list. Also, if either the current candidate or any
1147 * previous candidate is a special match, we can't assume that
1148 * conflicts are adjacent.
1149 *
1150 * We ignore defaulted arguments in deciding what is a match.
1151 */
1152 FuncCandidateList prevResult;
1153
1154 if (catlist->ordered && !any_special)
1155 {
1156 /* ndargs must be 0 if !any_special */
1157 if (effective_nargs == resultList->nargs &&
1158 memcmp(newResult->args,
1159 resultList->args,
1160 effective_nargs * sizeof(Oid)) == 0)
1161 prevResult = resultList;
1162 else
1163 prevResult = NULL;
1164 }
1165 else
1166 {
1167 int cmp_nargs = newResult->nargs - newResult->ndargs;
1168
1169 for (prevResult = resultList;
1170 prevResult;
1171 prevResult = prevResult->next)
1172 {
1173 if (cmp_nargs == prevResult->nargs - prevResult->ndargs &&
1174 memcmp(newResult->args,
1175 prevResult->args,
1176 cmp_nargs * sizeof(Oid)) == 0)
1177 break;
1178 }
1179 }
1180
1181 if (prevResult)
1182 {
1183 /*
1184 * We have a match with a previous result. Decide which one
1185 * to keep, or mark it ambiguous if we can't decide. The
1186 * logic here is preference > 0 means prefer the old result,
1187 * preference < 0 means prefer the new, preference = 0 means
1188 * ambiguous.
1189 */
1190 int preference;
1191
1192 if (pathpos != prevResult->pathpos)
1193 {
1194 /*
1195 * Prefer the one that's earlier in the search path.
1196 */
1197 preference = pathpos - prevResult->pathpos;
1198 }
1199 else if (variadic && prevResult->nvargs == 0)
1200 {
1201 /*
1202 * With variadic functions we could have, for example,
1203 * both foo(numeric) and foo(variadic numeric[]) in the
1204 * same namespace; if so we prefer the non-variadic match
1205 * on efficiency grounds.
1206 */
1207 preference = 1;
1208 }
1209 else if (!variadic && prevResult->nvargs > 0)
1210 {
1211 preference = -1;
1212 }
1213 else
1214 {
1215 /*----------
1216 * We can't decide. This can happen with, for example,
1217 * both foo(numeric, variadic numeric[]) and
1218 * foo(variadic numeric[]) in the same namespace, or
1219 * both foo(int) and foo (int, int default something)
1220 * in the same namespace, or both foo(a int, b text)
1221 * and foo(b text, a int) in the same namespace.
1222 *----------
1223 */
1224 preference = 0;
1225 }
1226
1227 if (preference > 0)
1228 {
1229 /* keep previous result */
1230 pfree(newResult);
1231 continue;
1232 }
1233 else if (preference < 0)
1234 {
1235 /* remove previous result from the list */
1236 if (prevResult == resultList)
1237 resultList = prevResult->next;
1238 else
1239 {
1240 FuncCandidateList prevPrevResult;
1241
1242 for (prevPrevResult = resultList;
1243 prevPrevResult;
1244 prevPrevResult = prevPrevResult->next)
1245 {
1246 if (prevResult == prevPrevResult->next)
1247 {
1248 prevPrevResult->next = prevResult->next;
1249 break;
1250 }
1251 }
1252 Assert(prevPrevResult); /* assert we found it */
1253 }
1254 pfree(prevResult);
1255 /* fall through to add newResult to list */
1256 }
1257 else
1258 {
1259 /* mark old result as ambiguous, discard new */
1260 prevResult->oid = InvalidOid;
1261 pfree(newResult);
1262 continue;
1263 }
1264 }
1265 }
1266
1267 /*
1268 * Okay to add it to result list
1269 */
1270 newResult->next = resultList;
1271 resultList = newResult;
1272 }
1273
1274 ReleaseSysCacheList(catlist);
1275
1276 return resultList;
1277}
1278
1279/*
1280 * MatchNamedCall
1281 * Given a pg_proc heap tuple and a call's list of argument names,
1282 * check whether the function could match the call.
1283 *
1284 * The call could match if all supplied argument names are accepted by
1285 * the function, in positions after the last positional argument, and there
1286 * are defaults for all unsupplied arguments.
1287 *
1288 * The number of positional arguments is nargs - list_length(argnames).
1289 * Note caller has already done basic checks on argument count.
1290 *
1291 * On match, return true and fill *argnumbers with a palloc'd array showing
1292 * the mapping from call argument positions to actual function argument
1293 * numbers. Defaulted arguments are included in this map, at positions
1294 * after the last supplied argument.
1295 */
1296static bool
1297MatchNamedCall(HeapTuple proctup, int nargs, List *argnames,
1298 int **argnumbers)
1299{
1300 Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
1301 int pronargs = procform->pronargs;
1302 int numposargs = nargs - list_length(argnames);
1303 int pronallargs;
1304 Oid *p_argtypes;
1305 char **p_argnames;
1306 char *p_argmodes;
1307 bool arggiven[FUNC_MAX_ARGS];
1308 bool isnull;
1309 int ap; /* call args position */
1310 int pp; /* proargs position */
1311 ListCell *lc;
1312
1313 Assert(argnames != NIL);
1314 Assert(numposargs >= 0);
1315 Assert(nargs <= pronargs);
1316
1317 /* Ignore this function if its proargnames is null */
1318 (void) SysCacheGetAttr(PROCOID, proctup, Anum_pg_proc_proargnames,
1319 &isnull);
1320 if (isnull)
1321 return false;
1322
1323 /* OK, let's extract the argument names and types */
1324 pronallargs = get_func_arg_info(proctup,
1325 &p_argtypes, &p_argnames, &p_argmodes);
1326 Assert(p_argnames != NULL);
1327
1328 /* initialize state for matching */
1329 *argnumbers = (int *) palloc(pronargs * sizeof(int));
1330 memset(arggiven, false, pronargs * sizeof(bool));
1331
1332 /* there are numposargs positional args before the named args */
1333 for (ap = 0; ap < numposargs; ap++)
1334 {
1335 (*argnumbers)[ap] = ap;
1336 arggiven[ap] = true;
1337 }
1338
1339 /* now examine the named args */
1340 foreach(lc, argnames)
1341 {
1342 char *argname = (char *) lfirst(lc);
1343 bool found;
1344 int i;
1345
1346 pp = 0;
1347 found = false;
1348 for (i = 0; i < pronallargs; i++)
1349 {
1350 /* consider only input parameters */
1351 if (p_argmodes &&
1352 (p_argmodes[i] != FUNC_PARAM_IN &&
1353 p_argmodes[i] != FUNC_PARAM_INOUT &&
1354 p_argmodes[i] != FUNC_PARAM_VARIADIC))
1355 continue;
1356 if (p_argnames[i] && strcmp(p_argnames[i], argname) == 0)
1357 {
1358 /* fail if argname matches a positional argument */
1359 if (arggiven[pp])
1360 return false;
1361 arggiven[pp] = true;
1362 (*argnumbers)[ap] = pp;
1363 found = true;
1364 break;
1365 }
1366 /* increase pp only for input parameters */
1367 pp++;
1368 }
1369 /* if name isn't in proargnames, fail */
1370 if (!found)
1371 return false;
1372 ap++;
1373 }
1374
1375 Assert(ap == nargs); /* processed all actual parameters */
1376
1377 /* Check for default arguments */
1378 if (nargs < pronargs)
1379 {
1380 int first_arg_with_default = pronargs - procform->pronargdefaults;
1381
1382 for (pp = numposargs; pp < pronargs; pp++)
1383 {
1384 if (arggiven[pp])
1385 continue;
1386 /* fail if arg not given and no default available */
1387 if (pp < first_arg_with_default)
1388 return false;
1389 (*argnumbers)[ap++] = pp;
1390 }
1391 }
1392
1393 Assert(ap == pronargs); /* processed all function parameters */
1394
1395 return true;
1396}
1397
1398/*
1399 * FunctionIsVisible
1400 * Determine whether a function (identified by OID) is visible in the
1401 * current search path. Visible means "would be found by searching
1402 * for the unqualified function name with exact argument matches".
1403 */
1404bool
1405FunctionIsVisible(Oid funcid)
1406{
1407 HeapTuple proctup;
1408 Form_pg_proc procform;
1409 Oid pronamespace;
1410 bool visible;
1411
1412 proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
1413 if (!HeapTupleIsValid(proctup))
1414 elog(ERROR, "cache lookup failed for function %u", funcid);
1415 procform = (Form_pg_proc) GETSTRUCT(proctup);
1416
1417 recomputeNamespacePath();
1418
1419 /*
1420 * Quick check: if it ain't in the path at all, it ain't visible. Items in
1421 * the system namespace are surely in the path and so we needn't even do
1422 * list_member_oid() for them.
1423 */
1424 pronamespace = procform->pronamespace;
1425 if (pronamespace != PG_CATALOG_NAMESPACE &&
1426 !list_member_oid(activeSearchPath, pronamespace))
1427 visible = false;
1428 else
1429 {
1430 /*
1431 * If it is in the path, it might still not be visible; it could be
1432 * hidden by another proc of the same name and arguments earlier in
1433 * the path. So we must do a slow check to see if this is the same
1434 * proc that would be found by FuncnameGetCandidates.
1435 */
1436 char *proname = NameStr(procform->proname);
1437 int nargs = procform->pronargs;
1438 FuncCandidateList clist;
1439
1440 visible = false;
1441
1442 clist = FuncnameGetCandidates(list_make1(makeString(proname)),
1443 nargs, NIL, false, false, false);
1444
1445 for (; clist; clist = clist->next)
1446 {
1447 if (memcmp(clist->args, procform->proargtypes.values,
1448 nargs * sizeof(Oid)) == 0)
1449 {
1450 /* Found the expected entry; is it the right proc? */
1451 visible = (clist->oid == funcid);
1452 break;
1453 }
1454 }
1455 }
1456
1457 ReleaseSysCache(proctup);
1458
1459 return visible;
1460}
1461
1462
1463/*
1464 * OpernameGetOprid
1465 * Given a possibly-qualified operator name and exact input datatypes,
1466 * look up the operator. Returns InvalidOid if not found.
1467 *
1468 * Pass oprleft = InvalidOid for a prefix op, oprright = InvalidOid for
1469 * a postfix op.
1470 *
1471 * If the operator name is not schema-qualified, it is sought in the current
1472 * namespace search path. If the name is schema-qualified and the given
1473 * schema does not exist, InvalidOid is returned.
1474 */
1475Oid
1476OpernameGetOprid(List *names, Oid oprleft, Oid oprright)
1477{
1478 char *schemaname;
1479 char *opername;
1480 CatCList *catlist;
1481 ListCell *l;
1482
1483 /* deconstruct the name list */
1484 DeconstructQualifiedName(names, &schemaname, &opername);
1485
1486 if (schemaname)
1487 {
1488 /* search only in exact schema given */
1489 Oid namespaceId;
1490
1491 namespaceId = LookupExplicitNamespace(schemaname, true);
1492 if (OidIsValid(namespaceId))
1493 {
1494 HeapTuple opertup;
1495
1496 opertup = SearchSysCache4(OPERNAMENSP,
1497 CStringGetDatum(opername),
1498 ObjectIdGetDatum(oprleft),
1499 ObjectIdGetDatum(oprright),
1500 ObjectIdGetDatum(namespaceId));
1501 if (HeapTupleIsValid(opertup))
1502 {
1503 Form_pg_operator operclass = (Form_pg_operator) GETSTRUCT(opertup);
1504 Oid result = operclass->oid;
1505
1506 ReleaseSysCache(opertup);
1507 return result;
1508 }
1509 }
1510
1511 return InvalidOid;
1512 }
1513
1514 /* Search syscache by name and argument types */
1515 catlist = SearchSysCacheList3(OPERNAMENSP,
1516 CStringGetDatum(opername),
1517 ObjectIdGetDatum(oprleft),
1518 ObjectIdGetDatum(oprright));
1519
1520 if (catlist->n_members == 0)
1521 {
1522 /* no hope, fall out early */
1523 ReleaseSysCacheList(catlist);
1524 return InvalidOid;
1525 }
1526
1527 /*
1528 * We have to find the list member that is first in the search path, if
1529 * there's more than one. This doubly-nested loop looks ugly, but in
1530 * practice there should usually be few catlist members.
1531 */
1532 recomputeNamespacePath();
1533
1534 foreach(l, activeSearchPath)
1535 {
1536 Oid namespaceId = lfirst_oid(l);
1537 int i;
1538
1539 if (namespaceId == myTempNamespace)
1540 continue; /* do not look in temp namespace */
1541
1542 for (i = 0; i < catlist->n_members; i++)
1543 {
1544 HeapTuple opertup = &catlist->members[i]->tuple;
1545 Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup);
1546
1547 if (operform->oprnamespace == namespaceId)
1548 {
1549 Oid result = operform->oid;
1550
1551 ReleaseSysCacheList(catlist);
1552 return result;
1553 }
1554 }
1555 }
1556
1557 ReleaseSysCacheList(catlist);
1558 return InvalidOid;
1559}
1560
1561/*
1562 * OpernameGetCandidates
1563 * Given a possibly-qualified operator name and operator kind,
1564 * retrieve a list of the possible matches.
1565 *
1566 * If oprkind is '\0', we return all operators matching the given name,
1567 * regardless of arguments.
1568 *
1569 * We search a single namespace if the operator name is qualified, else
1570 * all namespaces in the search path. The return list will never contain
1571 * multiple entries with identical argument lists --- in the multiple-
1572 * namespace case, we arrange for entries in earlier namespaces to mask
1573 * identical entries in later namespaces.
1574 *
1575 * The returned items always have two args[] entries --- one or the other
1576 * will be InvalidOid for a prefix or postfix oprkind. nargs is 2, too.
1577 */
1578FuncCandidateList
1579OpernameGetCandidates(List *names, char oprkind, bool missing_schema_ok)
1580{
1581 FuncCandidateList resultList = NULL;
1582 char *resultSpace = NULL;
1583 int nextResult = 0;
1584 char *schemaname;
1585 char *opername;
1586 Oid namespaceId;
1587 CatCList *catlist;
1588 int i;
1589
1590 /* deconstruct the name list */
1591 DeconstructQualifiedName(names, &schemaname, &opername);
1592
1593 if (schemaname)
1594 {
1595 /* use exact schema given */
1596 namespaceId = LookupExplicitNamespace(schemaname, missing_schema_ok);
1597 if (missing_schema_ok && !OidIsValid(namespaceId))
1598 return NULL;
1599 }
1600 else
1601 {
1602 /* flag to indicate we need namespace search */
1603 namespaceId = InvalidOid;
1604 recomputeNamespacePath();
1605 }
1606
1607 /* Search syscache by name only */
1608 catlist = SearchSysCacheList1(OPERNAMENSP, CStringGetDatum(opername));
1609
1610 /*
1611 * In typical scenarios, most if not all of the operators found by the
1612 * catcache search will end up getting returned; and there can be quite a
1613 * few, for common operator names such as '=' or '+'. To reduce the time
1614 * spent in palloc, we allocate the result space as an array large enough
1615 * to hold all the operators. The original coding of this routine did a
1616 * separate palloc for each operator, but profiling revealed that the
1617 * pallocs used an unreasonably large fraction of parsing time.
1618 */
1619#define SPACE_PER_OP MAXALIGN(offsetof(struct _FuncCandidateList, args) + \
1620 2 * sizeof(Oid))
1621
1622 if (catlist->n_members > 0)
1623 resultSpace = palloc(catlist->n_members * SPACE_PER_OP);
1624
1625 for (i = 0; i < catlist->n_members; i++)
1626 {
1627 HeapTuple opertup = &catlist->members[i]->tuple;
1628 Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup);
1629 int pathpos = 0;
1630 FuncCandidateList newResult;
1631
1632 /* Ignore operators of wrong kind, if specific kind requested */
1633 if (oprkind && operform->oprkind != oprkind)
1634 continue;
1635
1636 if (OidIsValid(namespaceId))
1637 {
1638 /* Consider only opers in specified namespace */
1639 if (operform->oprnamespace != namespaceId)
1640 continue;
1641 /* No need to check args, they must all be different */
1642 }
1643 else
1644 {
1645 /*
1646 * Consider only opers that are in the search path and are not in
1647 * the temp namespace.
1648 */
1649 ListCell *nsp;
1650
1651 foreach(nsp, activeSearchPath)
1652 {
1653 if (operform->oprnamespace == lfirst_oid(nsp) &&
1654 operform->oprnamespace != myTempNamespace)
1655 break;
1656 pathpos++;
1657 }
1658 if (nsp == NULL)
1659 continue; /* oper is not in search path */
1660
1661 /*
1662 * Okay, it's in the search path, but does it have the same
1663 * arguments as something we already accepted? If so, keep only
1664 * the one that appears earlier in the search path.
1665 *
1666 * If we have an ordered list from SearchSysCacheList (the normal
1667 * case), then any conflicting oper must immediately adjoin this
1668 * one in the list, so we only need to look at the newest result
1669 * item. If we have an unordered list, we have to scan the whole
1670 * result list.
1671 */
1672 if (resultList)
1673 {
1674 FuncCandidateList prevResult;
1675
1676 if (catlist->ordered)
1677 {
1678 if (operform->oprleft == resultList->args[0] &&
1679 operform->oprright == resultList->args[1])
1680 prevResult = resultList;
1681 else
1682 prevResult = NULL;
1683 }
1684 else
1685 {
1686 for (prevResult = resultList;
1687 prevResult;
1688 prevResult = prevResult->next)
1689 {
1690 if (operform->oprleft == prevResult->args[0] &&
1691 operform->oprright == prevResult->args[1])
1692 break;
1693 }
1694 }
1695 if (prevResult)
1696 {
1697 /* We have a match with a previous result */
1698 Assert(pathpos != prevResult->pathpos);
1699 if (pathpos > prevResult->pathpos)
1700 continue; /* keep previous result */
1701 /* replace previous result */
1702 prevResult->pathpos = pathpos;
1703 prevResult->oid = operform->oid;
1704 continue; /* args are same, of course */
1705 }
1706 }
1707 }
1708
1709 /*
1710 * Okay to add it to result list
1711 */
1712 newResult = (FuncCandidateList) (resultSpace + nextResult);
1713 nextResult += SPACE_PER_OP;
1714
1715 newResult->pathpos = pathpos;
1716 newResult->oid = operform->oid;
1717 newResult->nargs = 2;
1718 newResult->nvargs = 0;
1719 newResult->ndargs = 0;
1720 newResult->argnumbers = NULL;
1721 newResult->args[0] = operform->oprleft;
1722 newResult->args[1] = operform->oprright;
1723 newResult->next = resultList;
1724 resultList = newResult;
1725 }
1726
1727 ReleaseSysCacheList(catlist);
1728
1729 return resultList;
1730}
1731
1732/*
1733 * OperatorIsVisible
1734 * Determine whether an operator (identified by OID) is visible in the
1735 * current search path. Visible means "would be found by searching
1736 * for the unqualified operator name with exact argument matches".
1737 */
1738bool
1739OperatorIsVisible(Oid oprid)
1740{
1741 HeapTuple oprtup;
1742 Form_pg_operator oprform;
1743 Oid oprnamespace;
1744 bool visible;
1745
1746 oprtup = SearchSysCache1(OPEROID, ObjectIdGetDatum(oprid));
1747 if (!HeapTupleIsValid(oprtup))
1748 elog(ERROR, "cache lookup failed for operator %u", oprid);
1749 oprform = (Form_pg_operator) GETSTRUCT(oprtup);
1750
1751 recomputeNamespacePath();
1752
1753 /*
1754 * Quick check: if it ain't in the path at all, it ain't visible. Items in
1755 * the system namespace are surely in the path and so we needn't even do
1756 * list_member_oid() for them.
1757 */
1758 oprnamespace = oprform->oprnamespace;
1759 if (oprnamespace != PG_CATALOG_NAMESPACE &&
1760 !list_member_oid(activeSearchPath, oprnamespace))
1761 visible = false;
1762 else
1763 {
1764 /*
1765 * If it is in the path, it might still not be visible; it could be
1766 * hidden by another operator of the same name and arguments earlier
1767 * in the path. So we must do a slow check to see if this is the same
1768 * operator that would be found by OpernameGetOprid.
1769 */
1770 char *oprname = NameStr(oprform->oprname);
1771
1772 visible = (OpernameGetOprid(list_make1(makeString(oprname)),
1773 oprform->oprleft, oprform->oprright)
1774 == oprid);
1775 }
1776
1777 ReleaseSysCache(oprtup);
1778
1779 return visible;
1780}
1781
1782
1783/*
1784 * OpclassnameGetOpcid
1785 * Try to resolve an unqualified index opclass name.
1786 * Returns OID if opclass found in search path, else InvalidOid.
1787 *
1788 * This is essentially the same as TypenameGetTypid, but we have to have
1789 * an extra argument for the index AM OID.
1790 */
1791Oid
1792OpclassnameGetOpcid(Oid amid, const char *opcname)
1793{
1794 Oid opcid;
1795 ListCell *l;
1796
1797 recomputeNamespacePath();
1798
1799 foreach(l, activeSearchPath)
1800 {
1801 Oid namespaceId = lfirst_oid(l);
1802
1803 if (namespaceId == myTempNamespace)
1804 continue; /* do not look in temp namespace */
1805
1806 opcid = GetSysCacheOid3(CLAAMNAMENSP, Anum_pg_opclass_oid,
1807 ObjectIdGetDatum(amid),
1808 PointerGetDatum(opcname),
1809 ObjectIdGetDatum(namespaceId));
1810 if (OidIsValid(opcid))
1811 return opcid;
1812 }
1813
1814 /* Not found in path */
1815 return InvalidOid;
1816}
1817
1818/*
1819 * OpclassIsVisible
1820 * Determine whether an opclass (identified by OID) is visible in the
1821 * current search path. Visible means "would be found by searching
1822 * for the unqualified opclass name".
1823 */
1824bool
1825OpclassIsVisible(Oid opcid)
1826{
1827 HeapTuple opctup;
1828 Form_pg_opclass opcform;
1829 Oid opcnamespace;
1830 bool visible;
1831
1832 opctup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opcid));
1833 if (!HeapTupleIsValid(opctup))
1834 elog(ERROR, "cache lookup failed for opclass %u", opcid);
1835 opcform = (Form_pg_opclass) GETSTRUCT(opctup);
1836
1837 recomputeNamespacePath();
1838
1839 /*
1840 * Quick check: if it ain't in the path at all, it ain't visible. Items in
1841 * the system namespace are surely in the path and so we needn't even do
1842 * list_member_oid() for them.
1843 */
1844 opcnamespace = opcform->opcnamespace;
1845 if (opcnamespace != PG_CATALOG_NAMESPACE &&
1846 !list_member_oid(activeSearchPath, opcnamespace))
1847 visible = false;
1848 else
1849 {
1850 /*
1851 * If it is in the path, it might still not be visible; it could be
1852 * hidden by another opclass of the same name earlier in the path. So
1853 * we must do a slow check to see if this opclass would be found by
1854 * OpclassnameGetOpcid.
1855 */
1856 char *opcname = NameStr(opcform->opcname);
1857
1858 visible = (OpclassnameGetOpcid(opcform->opcmethod, opcname) == opcid);
1859 }
1860
1861 ReleaseSysCache(opctup);
1862
1863 return visible;
1864}
1865
1866/*
1867 * OpfamilynameGetOpfid
1868 * Try to resolve an unqualified index opfamily name.
1869 * Returns OID if opfamily found in search path, else InvalidOid.
1870 *
1871 * This is essentially the same as TypenameGetTypid, but we have to have
1872 * an extra argument for the index AM OID.
1873 */
1874Oid
1875OpfamilynameGetOpfid(Oid amid, const char *opfname)
1876{
1877 Oid opfid;
1878 ListCell *l;
1879
1880 recomputeNamespacePath();
1881
1882 foreach(l, activeSearchPath)
1883 {
1884 Oid namespaceId = lfirst_oid(l);
1885
1886 if (namespaceId == myTempNamespace)
1887 continue; /* do not look in temp namespace */
1888
1889 opfid = GetSysCacheOid3(OPFAMILYAMNAMENSP, Anum_pg_opfamily_oid,
1890 ObjectIdGetDatum(amid),
1891 PointerGetDatum(opfname),
1892 ObjectIdGetDatum(namespaceId));
1893 if (OidIsValid(opfid))
1894 return opfid;
1895 }
1896
1897 /* Not found in path */
1898 return InvalidOid;
1899}
1900
1901/*
1902 * OpfamilyIsVisible
1903 * Determine whether an opfamily (identified by OID) is visible in the
1904 * current search path. Visible means "would be found by searching
1905 * for the unqualified opfamily name".
1906 */
1907bool
1908OpfamilyIsVisible(Oid opfid)
1909{
1910 HeapTuple opftup;
1911 Form_pg_opfamily opfform;
1912 Oid opfnamespace;
1913 bool visible;
1914
1915 opftup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfid));
1916 if (!HeapTupleIsValid(opftup))
1917 elog(ERROR, "cache lookup failed for opfamily %u", opfid);
1918 opfform = (Form_pg_opfamily) GETSTRUCT(opftup);
1919
1920 recomputeNamespacePath();
1921
1922 /*
1923 * Quick check: if it ain't in the path at all, it ain't visible. Items in
1924 * the system namespace are surely in the path and so we needn't even do
1925 * list_member_oid() for them.
1926 */
1927 opfnamespace = opfform->opfnamespace;
1928 if (opfnamespace != PG_CATALOG_NAMESPACE &&
1929 !list_member_oid(activeSearchPath, opfnamespace))
1930 visible = false;
1931 else
1932 {
1933 /*
1934 * If it is in the path, it might still not be visible; it could be
1935 * hidden by another opfamily of the same name earlier in the path. So
1936 * we must do a slow check to see if this opfamily would be found by
1937 * OpfamilynameGetOpfid.
1938 */
1939 char *opfname = NameStr(opfform->opfname);
1940
1941 visible = (OpfamilynameGetOpfid(opfform->opfmethod, opfname) == opfid);
1942 }
1943
1944 ReleaseSysCache(opftup);
1945
1946 return visible;
1947}
1948
1949/*
1950 * lookup_collation
1951 * If there's a collation of the given name/namespace, and it works
1952 * with the given encoding, return its OID. Else return InvalidOid.
1953 */
1954static Oid
1955lookup_collation(const char *collname, Oid collnamespace, int32 encoding)
1956{
1957 Oid collid;
1958 HeapTuple colltup;
1959 Form_pg_collation collform;
1960
1961 /* Check for encoding-specific entry (exact match) */
1962 collid = GetSysCacheOid3(COLLNAMEENCNSP, Anum_pg_collation_oid,
1963 PointerGetDatum(collname),
1964 Int32GetDatum(encoding),
1965 ObjectIdGetDatum(collnamespace));
1966 if (OidIsValid(collid))
1967 return collid;
1968
1969 /*
1970 * Check for any-encoding entry. This takes a bit more work: while libc
1971 * collations with collencoding = -1 do work with all encodings, ICU
1972 * collations only work with certain encodings, so we have to check that
1973 * aspect before deciding it's a match.
1974 */
1975 colltup = SearchSysCache3(COLLNAMEENCNSP,
1976 PointerGetDatum(collname),
1977 Int32GetDatum(-1),
1978 ObjectIdGetDatum(collnamespace));
1979 if (!HeapTupleIsValid(colltup))
1980 return InvalidOid;
1981 collform = (Form_pg_collation) GETSTRUCT(colltup);
1982 if (collform->collprovider == COLLPROVIDER_ICU)
1983 {
1984 if (is_encoding_supported_by_icu(encoding))
1985 collid = collform->oid;
1986 else
1987 collid = InvalidOid;
1988 }
1989 else
1990 {
1991 collid = collform->oid;
1992 }
1993 ReleaseSysCache(colltup);
1994 return collid;
1995}
1996
1997/*
1998 * CollationGetCollid
1999 * Try to resolve an unqualified collation name.
2000 * Returns OID if collation found in search path, else InvalidOid.
2001 *
2002 * Note that this will only find collations that work with the current
2003 * database's encoding.
2004 */
2005Oid
2006CollationGetCollid(const char *collname)
2007{
2008 int32 dbencoding = GetDatabaseEncoding();
2009 ListCell *l;
2010
2011 recomputeNamespacePath();
2012
2013 foreach(l, activeSearchPath)
2014 {
2015 Oid namespaceId = lfirst_oid(l);
2016 Oid collid;
2017
2018 if (namespaceId == myTempNamespace)
2019 continue; /* do not look in temp namespace */
2020
2021 collid = lookup_collation(collname, namespaceId, dbencoding);
2022 if (OidIsValid(collid))
2023 return collid;
2024 }
2025
2026 /* Not found in path */
2027 return InvalidOid;
2028}
2029
2030/*
2031 * CollationIsVisible
2032 * Determine whether a collation (identified by OID) is visible in the
2033 * current search path. Visible means "would be found by searching
2034 * for the unqualified collation name".
2035 *
2036 * Note that only collations that work with the current database's encoding
2037 * will be considered visible.
2038 */
2039bool
2040CollationIsVisible(Oid collid)
2041{
2042 HeapTuple colltup;
2043 Form_pg_collation collform;
2044 Oid collnamespace;
2045 bool visible;
2046
2047 colltup = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
2048 if (!HeapTupleIsValid(colltup))
2049 elog(ERROR, "cache lookup failed for collation %u", collid);
2050 collform = (Form_pg_collation) GETSTRUCT(colltup);
2051
2052 recomputeNamespacePath();
2053
2054 /*
2055 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2056 * the system namespace are surely in the path and so we needn't even do
2057 * list_member_oid() for them.
2058 */
2059 collnamespace = collform->collnamespace;
2060 if (collnamespace != PG_CATALOG_NAMESPACE &&
2061 !list_member_oid(activeSearchPath, collnamespace))
2062 visible = false;
2063 else
2064 {
2065 /*
2066 * If it is in the path, it might still not be visible; it could be
2067 * hidden by another collation of the same name earlier in the path,
2068 * or it might not work with the current DB encoding. So we must do a
2069 * slow check to see if this collation would be found by
2070 * CollationGetCollid.
2071 */
2072 char *collname = NameStr(collform->collname);
2073
2074 visible = (CollationGetCollid(collname) == collid);
2075 }
2076
2077 ReleaseSysCache(colltup);
2078
2079 return visible;
2080}
2081
2082
2083/*
2084 * ConversionGetConid
2085 * Try to resolve an unqualified conversion name.
2086 * Returns OID if conversion found in search path, else InvalidOid.
2087 *
2088 * This is essentially the same as RelnameGetRelid.
2089 */
2090Oid
2091ConversionGetConid(const char *conname)
2092{
2093 Oid conid;
2094 ListCell *l;
2095
2096 recomputeNamespacePath();
2097
2098 foreach(l, activeSearchPath)
2099 {
2100 Oid namespaceId = lfirst_oid(l);
2101
2102 if (namespaceId == myTempNamespace)
2103 continue; /* do not look in temp namespace */
2104
2105 conid = GetSysCacheOid2(CONNAMENSP, Anum_pg_conversion_oid,
2106 PointerGetDatum(conname),
2107 ObjectIdGetDatum(namespaceId));
2108 if (OidIsValid(conid))
2109 return conid;
2110 }
2111
2112 /* Not found in path */
2113 return InvalidOid;
2114}
2115
2116/*
2117 * ConversionIsVisible
2118 * Determine whether a conversion (identified by OID) is visible in the
2119 * current search path. Visible means "would be found by searching
2120 * for the unqualified conversion name".
2121 */
2122bool
2123ConversionIsVisible(Oid conid)
2124{
2125 HeapTuple contup;
2126 Form_pg_conversion conform;
2127 Oid connamespace;
2128 bool visible;
2129
2130 contup = SearchSysCache1(CONVOID, ObjectIdGetDatum(conid));
2131 if (!HeapTupleIsValid(contup))
2132 elog(ERROR, "cache lookup failed for conversion %u", conid);
2133 conform = (Form_pg_conversion) GETSTRUCT(contup);
2134
2135 recomputeNamespacePath();
2136
2137 /*
2138 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2139 * the system namespace are surely in the path and so we needn't even do
2140 * list_member_oid() for them.
2141 */
2142 connamespace = conform->connamespace;
2143 if (connamespace != PG_CATALOG_NAMESPACE &&
2144 !list_member_oid(activeSearchPath, connamespace))
2145 visible = false;
2146 else
2147 {
2148 /*
2149 * If it is in the path, it might still not be visible; it could be
2150 * hidden by another conversion of the same name earlier in the path.
2151 * So we must do a slow check to see if this conversion would be found
2152 * by ConversionGetConid.
2153 */
2154 char *conname = NameStr(conform->conname);
2155
2156 visible = (ConversionGetConid(conname) == conid);
2157 }
2158
2159 ReleaseSysCache(contup);
2160
2161 return visible;
2162}
2163
2164/*
2165 * get_statistics_object_oid - find a statistics object by possibly qualified name
2166 *
2167 * If not found, returns InvalidOid if missing_ok, else throws error
2168 */
2169Oid
2170get_statistics_object_oid(List *names, bool missing_ok)
2171{
2172 char *schemaname;
2173 char *stats_name;
2174 Oid namespaceId;
2175 Oid stats_oid = InvalidOid;
2176 ListCell *l;
2177
2178 /* deconstruct the name list */
2179 DeconstructQualifiedName(names, &schemaname, &stats_name);
2180
2181 if (schemaname)
2182 {
2183 /* use exact schema given */
2184 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
2185 if (missing_ok && !OidIsValid(namespaceId))
2186 stats_oid = InvalidOid;
2187 else
2188 stats_oid = GetSysCacheOid2(STATEXTNAMENSP, Anum_pg_statistic_ext_oid,
2189 PointerGetDatum(stats_name),
2190 ObjectIdGetDatum(namespaceId));
2191 }
2192 else
2193 {
2194 /* search for it in search path */
2195 recomputeNamespacePath();
2196
2197 foreach(l, activeSearchPath)
2198 {
2199 namespaceId = lfirst_oid(l);
2200
2201 if (namespaceId == myTempNamespace)
2202 continue; /* do not look in temp namespace */
2203 stats_oid = GetSysCacheOid2(STATEXTNAMENSP, Anum_pg_statistic_ext_oid,
2204 PointerGetDatum(stats_name),
2205 ObjectIdGetDatum(namespaceId));
2206 if (OidIsValid(stats_oid))
2207 break;
2208 }
2209 }
2210
2211 if (!OidIsValid(stats_oid) && !missing_ok)
2212 ereport(ERROR,
2213 (errcode(ERRCODE_UNDEFINED_OBJECT),
2214 errmsg("statistics object \"%s\" does not exist",
2215 NameListToString(names))));
2216
2217 return stats_oid;
2218}
2219
2220/*
2221 * StatisticsObjIsVisible
2222 * Determine whether a statistics object (identified by OID) is visible in
2223 * the current search path. Visible means "would be found by searching
2224 * for the unqualified statistics object name".
2225 */
2226bool
2227StatisticsObjIsVisible(Oid relid)
2228{
2229 HeapTuple stxtup;
2230 Form_pg_statistic_ext stxform;
2231 Oid stxnamespace;
2232 bool visible;
2233
2234 stxtup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(relid));
2235 if (!HeapTupleIsValid(stxtup))
2236 elog(ERROR, "cache lookup failed for statistics object %u", relid);
2237 stxform = (Form_pg_statistic_ext) GETSTRUCT(stxtup);
2238
2239 recomputeNamespacePath();
2240
2241 /*
2242 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2243 * the system namespace are surely in the path and so we needn't even do
2244 * list_member_oid() for them.
2245 */
2246 stxnamespace = stxform->stxnamespace;
2247 if (stxnamespace != PG_CATALOG_NAMESPACE &&
2248 !list_member_oid(activeSearchPath, stxnamespace))
2249 visible = false;
2250 else
2251 {
2252 /*
2253 * If it is in the path, it might still not be visible; it could be
2254 * hidden by another statistics object of the same name earlier in the
2255 * path. So we must do a slow check for conflicting objects.
2256 */
2257 char *stxname = NameStr(stxform->stxname);
2258 ListCell *l;
2259
2260 visible = false;
2261 foreach(l, activeSearchPath)
2262 {
2263 Oid namespaceId = lfirst_oid(l);
2264
2265 if (namespaceId == stxnamespace)
2266 {
2267 /* Found it first in path */
2268 visible = true;
2269 break;
2270 }
2271 if (SearchSysCacheExists2(STATEXTNAMENSP,
2272 PointerGetDatum(stxname),
2273 ObjectIdGetDatum(namespaceId)))
2274 {
2275 /* Found something else first in path */
2276 break;
2277 }
2278 }
2279 }
2280
2281 ReleaseSysCache(stxtup);
2282
2283 return visible;
2284}
2285
2286/*
2287 * get_ts_parser_oid - find a TS parser by possibly qualified name
2288 *
2289 * If not found, returns InvalidOid if missing_ok, else throws error
2290 */
2291Oid
2292get_ts_parser_oid(List *names, bool missing_ok)
2293{
2294 char *schemaname;
2295 char *parser_name;
2296 Oid namespaceId;
2297 Oid prsoid = InvalidOid;
2298 ListCell *l;
2299
2300 /* deconstruct the name list */
2301 DeconstructQualifiedName(names, &schemaname, &parser_name);
2302
2303 if (schemaname)
2304 {
2305 /* use exact schema given */
2306 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
2307 if (missing_ok && !OidIsValid(namespaceId))
2308 prsoid = InvalidOid;
2309 else
2310 prsoid = GetSysCacheOid2(TSPARSERNAMENSP, Anum_pg_ts_parser_oid,
2311 PointerGetDatum(parser_name),
2312 ObjectIdGetDatum(namespaceId));
2313 }
2314 else
2315 {
2316 /* search for it in search path */
2317 recomputeNamespacePath();
2318
2319 foreach(l, activeSearchPath)
2320 {
2321 namespaceId = lfirst_oid(l);
2322
2323 if (namespaceId == myTempNamespace)
2324 continue; /* do not look in temp namespace */
2325
2326 prsoid = GetSysCacheOid2(TSPARSERNAMENSP, Anum_pg_ts_parser_oid,
2327 PointerGetDatum(parser_name),
2328 ObjectIdGetDatum(namespaceId));
2329 if (OidIsValid(prsoid))
2330 break;
2331 }
2332 }
2333
2334 if (!OidIsValid(prsoid) && !missing_ok)
2335 ereport(ERROR,
2336 (errcode(ERRCODE_UNDEFINED_OBJECT),
2337 errmsg("text search parser \"%s\" does not exist",
2338 NameListToString(names))));
2339
2340 return prsoid;
2341}
2342
2343/*
2344 * TSParserIsVisible
2345 * Determine whether a parser (identified by OID) is visible in the
2346 * current search path. Visible means "would be found by searching
2347 * for the unqualified parser name".
2348 */
2349bool
2350TSParserIsVisible(Oid prsId)
2351{
2352 HeapTuple tup;
2353 Form_pg_ts_parser form;
2354 Oid namespace;
2355 bool visible;
2356
2357 tup = SearchSysCache1(TSPARSEROID, ObjectIdGetDatum(prsId));
2358 if (!HeapTupleIsValid(tup))
2359 elog(ERROR, "cache lookup failed for text search parser %u", prsId);
2360 form = (Form_pg_ts_parser) GETSTRUCT(tup);
2361
2362 recomputeNamespacePath();
2363
2364 /*
2365 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2366 * the system namespace are surely in the path and so we needn't even do
2367 * list_member_oid() for them.
2368 */
2369 namespace = form->prsnamespace;
2370 if (namespace != PG_CATALOG_NAMESPACE &&
2371 !list_member_oid(activeSearchPath, namespace))
2372 visible = false;
2373 else
2374 {
2375 /*
2376 * If it is in the path, it might still not be visible; it could be
2377 * hidden by another parser of the same name earlier in the path. So
2378 * we must do a slow check for conflicting parsers.
2379 */
2380 char *name = NameStr(form->prsname);
2381 ListCell *l;
2382
2383 visible = false;
2384 foreach(l, activeSearchPath)
2385 {
2386 Oid namespaceId = lfirst_oid(l);
2387
2388 if (namespaceId == myTempNamespace)
2389 continue; /* do not look in temp namespace */
2390
2391 if (namespaceId == namespace)
2392 {
2393 /* Found it first in path */
2394 visible = true;
2395 break;
2396 }
2397 if (SearchSysCacheExists2(TSPARSERNAMENSP,
2398 PointerGetDatum(name),
2399 ObjectIdGetDatum(namespaceId)))
2400 {
2401 /* Found something else first in path */
2402 break;
2403 }
2404 }
2405 }
2406
2407 ReleaseSysCache(tup);
2408
2409 return visible;
2410}
2411
2412/*
2413 * get_ts_dict_oid - find a TS dictionary by possibly qualified name
2414 *
2415 * If not found, returns InvalidOid if failOK, else throws error
2416 */
2417Oid
2418get_ts_dict_oid(List *names, bool missing_ok)
2419{
2420 char *schemaname;
2421 char *dict_name;
2422 Oid namespaceId;
2423 Oid dictoid = InvalidOid;
2424 ListCell *l;
2425
2426 /* deconstruct the name list */
2427 DeconstructQualifiedName(names, &schemaname, &dict_name);
2428
2429 if (schemaname)
2430 {
2431 /* use exact schema given */
2432 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
2433 if (missing_ok && !OidIsValid(namespaceId))
2434 dictoid = InvalidOid;
2435 else
2436 dictoid = GetSysCacheOid2(TSDICTNAMENSP, Anum_pg_ts_dict_oid,
2437 PointerGetDatum(dict_name),
2438 ObjectIdGetDatum(namespaceId));
2439 }
2440 else
2441 {
2442 /* search for it in search path */
2443 recomputeNamespacePath();
2444
2445 foreach(l, activeSearchPath)
2446 {
2447 namespaceId = lfirst_oid(l);
2448
2449 if (namespaceId == myTempNamespace)
2450 continue; /* do not look in temp namespace */
2451
2452 dictoid = GetSysCacheOid2(TSDICTNAMENSP, Anum_pg_ts_dict_oid,
2453 PointerGetDatum(dict_name),
2454 ObjectIdGetDatum(namespaceId));
2455 if (OidIsValid(dictoid))
2456 break;
2457 }
2458 }
2459
2460 if (!OidIsValid(dictoid) && !missing_ok)
2461 ereport(ERROR,
2462 (errcode(ERRCODE_UNDEFINED_OBJECT),
2463 errmsg("text search dictionary \"%s\" does not exist",
2464 NameListToString(names))));
2465
2466 return dictoid;
2467}
2468
2469/*
2470 * TSDictionaryIsVisible
2471 * Determine whether a dictionary (identified by OID) is visible in the
2472 * current search path. Visible means "would be found by searching
2473 * for the unqualified dictionary name".
2474 */
2475bool
2476TSDictionaryIsVisible(Oid dictId)
2477{
2478 HeapTuple tup;
2479 Form_pg_ts_dict form;
2480 Oid namespace;
2481 bool visible;
2482
2483 tup = SearchSysCache1(TSDICTOID, ObjectIdGetDatum(dictId));
2484 if (!HeapTupleIsValid(tup))
2485 elog(ERROR, "cache lookup failed for text search dictionary %u",
2486 dictId);
2487 form = (Form_pg_ts_dict) GETSTRUCT(tup);
2488
2489 recomputeNamespacePath();
2490
2491 /*
2492 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2493 * the system namespace are surely in the path and so we needn't even do
2494 * list_member_oid() for them.
2495 */
2496 namespace = form->dictnamespace;
2497 if (namespace != PG_CATALOG_NAMESPACE &&
2498 !list_member_oid(activeSearchPath, namespace))
2499 visible = false;
2500 else
2501 {
2502 /*
2503 * If it is in the path, it might still not be visible; it could be
2504 * hidden by another dictionary of the same name earlier in the path.
2505 * So we must do a slow check for conflicting dictionaries.
2506 */
2507 char *name = NameStr(form->dictname);
2508 ListCell *l;
2509
2510 visible = false;
2511 foreach(l, activeSearchPath)
2512 {
2513 Oid namespaceId = lfirst_oid(l);
2514
2515 if (namespaceId == myTempNamespace)
2516 continue; /* do not look in temp namespace */
2517
2518 if (namespaceId == namespace)
2519 {
2520 /* Found it first in path */
2521 visible = true;
2522 break;
2523 }
2524 if (SearchSysCacheExists2(TSDICTNAMENSP,
2525 PointerGetDatum(name),
2526 ObjectIdGetDatum(namespaceId)))
2527 {
2528 /* Found something else first in path */
2529 break;
2530 }
2531 }
2532 }
2533
2534 ReleaseSysCache(tup);
2535
2536 return visible;
2537}
2538
2539/*
2540 * get_ts_template_oid - find a TS template by possibly qualified name
2541 *
2542 * If not found, returns InvalidOid if missing_ok, else throws error
2543 */
2544Oid
2545get_ts_template_oid(List *names, bool missing_ok)
2546{
2547 char *schemaname;
2548 char *template_name;
2549 Oid namespaceId;
2550 Oid tmploid = InvalidOid;
2551 ListCell *l;
2552
2553 /* deconstruct the name list */
2554 DeconstructQualifiedName(names, &schemaname, &template_name);
2555
2556 if (schemaname)
2557 {
2558 /* use exact schema given */
2559 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
2560 if (missing_ok && !OidIsValid(namespaceId))
2561 tmploid = InvalidOid;
2562 else
2563 tmploid = GetSysCacheOid2(TSTEMPLATENAMENSP, Anum_pg_ts_template_oid,
2564 PointerGetDatum(template_name),
2565 ObjectIdGetDatum(namespaceId));
2566 }
2567 else
2568 {
2569 /* search for it in search path */
2570 recomputeNamespacePath();
2571
2572 foreach(l, activeSearchPath)
2573 {
2574 namespaceId = lfirst_oid(l);
2575
2576 if (namespaceId == myTempNamespace)
2577 continue; /* do not look in temp namespace */
2578
2579 tmploid = GetSysCacheOid2(TSTEMPLATENAMENSP, Anum_pg_ts_template_oid,
2580 PointerGetDatum(template_name),
2581 ObjectIdGetDatum(namespaceId));
2582 if (OidIsValid(tmploid))
2583 break;
2584 }
2585 }
2586
2587 if (!OidIsValid(tmploid) && !missing_ok)
2588 ereport(ERROR,
2589 (errcode(ERRCODE_UNDEFINED_OBJECT),
2590 errmsg("text search template \"%s\" does not exist",
2591 NameListToString(names))));
2592
2593 return tmploid;
2594}
2595
2596/*
2597 * TSTemplateIsVisible
2598 * Determine whether a template (identified by OID) is visible in the
2599 * current search path. Visible means "would be found by searching
2600 * for the unqualified template name".
2601 */
2602bool
2603TSTemplateIsVisible(Oid tmplId)
2604{
2605 HeapTuple tup;
2606 Form_pg_ts_template form;
2607 Oid namespace;
2608 bool visible;
2609
2610 tup = SearchSysCache1(TSTEMPLATEOID, ObjectIdGetDatum(tmplId));
2611 if (!HeapTupleIsValid(tup))
2612 elog(ERROR, "cache lookup failed for text search template %u", tmplId);
2613 form = (Form_pg_ts_template) GETSTRUCT(tup);
2614
2615 recomputeNamespacePath();
2616
2617 /*
2618 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2619 * the system namespace are surely in the path and so we needn't even do
2620 * list_member_oid() for them.
2621 */
2622 namespace = form->tmplnamespace;
2623 if (namespace != PG_CATALOG_NAMESPACE &&
2624 !list_member_oid(activeSearchPath, namespace))
2625 visible = false;
2626 else
2627 {
2628 /*
2629 * If it is in the path, it might still not be visible; it could be
2630 * hidden by another template of the same name earlier in the path. So
2631 * we must do a slow check for conflicting templates.
2632 */
2633 char *name = NameStr(form->tmplname);
2634 ListCell *l;
2635
2636 visible = false;
2637 foreach(l, activeSearchPath)
2638 {
2639 Oid namespaceId = lfirst_oid(l);
2640
2641 if (namespaceId == myTempNamespace)
2642 continue; /* do not look in temp namespace */
2643
2644 if (namespaceId == namespace)
2645 {
2646 /* Found it first in path */
2647 visible = true;
2648 break;
2649 }
2650 if (SearchSysCacheExists2(TSTEMPLATENAMENSP,
2651 PointerGetDatum(name),
2652 ObjectIdGetDatum(namespaceId)))
2653 {
2654 /* Found something else first in path */
2655 break;
2656 }
2657 }
2658 }
2659
2660 ReleaseSysCache(tup);
2661
2662 return visible;
2663}
2664
2665/*
2666 * get_ts_config_oid - find a TS config by possibly qualified name
2667 *
2668 * If not found, returns InvalidOid if missing_ok, else throws error
2669 */
2670Oid
2671get_ts_config_oid(List *names, bool missing_ok)
2672{
2673 char *schemaname;
2674 char *config_name;
2675 Oid namespaceId;
2676 Oid cfgoid = InvalidOid;
2677 ListCell *l;
2678
2679 /* deconstruct the name list */
2680 DeconstructQualifiedName(names, &schemaname, &config_name);
2681
2682 if (schemaname)
2683 {
2684 /* use exact schema given */
2685 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
2686 if (missing_ok && !OidIsValid(namespaceId))
2687 cfgoid = InvalidOid;
2688 else
2689 cfgoid = GetSysCacheOid2(TSCONFIGNAMENSP, Anum_pg_ts_config_oid,
2690 PointerGetDatum(config_name),
2691 ObjectIdGetDatum(namespaceId));
2692 }
2693 else
2694 {
2695 /* search for it in search path */
2696 recomputeNamespacePath();
2697
2698 foreach(l, activeSearchPath)
2699 {
2700 namespaceId = lfirst_oid(l);
2701
2702 if (namespaceId == myTempNamespace)
2703 continue; /* do not look in temp namespace */
2704
2705 cfgoid = GetSysCacheOid2(TSCONFIGNAMENSP, Anum_pg_ts_config_oid,
2706 PointerGetDatum(config_name),
2707 ObjectIdGetDatum(namespaceId));
2708 if (OidIsValid(cfgoid))
2709 break;
2710 }
2711 }
2712
2713 if (!OidIsValid(cfgoid) && !missing_ok)
2714 ereport(ERROR,
2715 (errcode(ERRCODE_UNDEFINED_OBJECT),
2716 errmsg("text search configuration \"%s\" does not exist",
2717 NameListToString(names))));
2718
2719 return cfgoid;
2720}
2721
2722/*
2723 * TSConfigIsVisible
2724 * Determine whether a text search configuration (identified by OID)
2725 * is visible in the current search path. Visible means "would be found
2726 * by searching for the unqualified text search configuration name".
2727 */
2728bool
2729TSConfigIsVisible(Oid cfgid)
2730{
2731 HeapTuple tup;
2732 Form_pg_ts_config form;
2733 Oid namespace;
2734 bool visible;
2735
2736 tup = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgid));
2737 if (!HeapTupleIsValid(tup))
2738 elog(ERROR, "cache lookup failed for text search configuration %u",
2739 cfgid);
2740 form = (Form_pg_ts_config) GETSTRUCT(tup);
2741
2742 recomputeNamespacePath();
2743
2744 /*
2745 * Quick check: if it ain't in the path at all, it ain't visible. Items in
2746 * the system namespace are surely in the path and so we needn't even do
2747 * list_member_oid() for them.
2748 */
2749 namespace = form->cfgnamespace;
2750 if (namespace != PG_CATALOG_NAMESPACE &&
2751 !list_member_oid(activeSearchPath, namespace))
2752 visible = false;
2753 else
2754 {
2755 /*
2756 * If it is in the path, it might still not be visible; it could be
2757 * hidden by another configuration of the same name earlier in the
2758 * path. So we must do a slow check for conflicting configurations.
2759 */
2760 char *name = NameStr(form->cfgname);
2761 ListCell *l;
2762
2763 visible = false;
2764 foreach(l, activeSearchPath)
2765 {
2766 Oid namespaceId = lfirst_oid(l);
2767
2768 if (namespaceId == myTempNamespace)
2769 continue; /* do not look in temp namespace */
2770
2771 if (namespaceId == namespace)
2772 {
2773 /* Found it first in path */
2774 visible = true;
2775 break;
2776 }
2777 if (SearchSysCacheExists2(TSCONFIGNAMENSP,
2778 PointerGetDatum(name),
2779 ObjectIdGetDatum(namespaceId)))
2780 {
2781 /* Found something else first in path */
2782 break;
2783 }
2784 }
2785 }
2786
2787 ReleaseSysCache(tup);
2788
2789 return visible;
2790}
2791
2792
2793/*
2794 * DeconstructQualifiedName
2795 * Given a possibly-qualified name expressed as a list of String nodes,
2796 * extract the schema name and object name.
2797 *
2798 * *nspname_p is set to NULL if there is no explicit schema name.
2799 */
2800void
2801DeconstructQualifiedName(List *names,
2802 char **nspname_p,
2803 char **objname_p)
2804{
2805 char *catalogname;
2806 char *schemaname = NULL;
2807 char *objname = NULL;
2808
2809 switch (list_length(names))
2810 {
2811 case 1:
2812 objname = strVal(linitial(names));
2813 break;
2814 case 2:
2815 schemaname = strVal(linitial(names));
2816 objname = strVal(lsecond(names));
2817 break;
2818 case 3:
2819 catalogname = strVal(linitial(names));
2820 schemaname = strVal(lsecond(names));
2821 objname = strVal(lthird(names));
2822
2823 /*
2824 * We check the catalog name and then ignore it.
2825 */
2826 if (strcmp(catalogname, get_database_name(MyDatabaseId)) != 0)
2827 ereport(ERROR,
2828 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2829 errmsg("cross-database references are not implemented: %s",
2830 NameListToString(names))));
2831 break;
2832 default:
2833 ereport(ERROR,
2834 (errcode(ERRCODE_SYNTAX_ERROR),
2835 errmsg("improper qualified name (too many dotted names): %s",
2836 NameListToString(names))));
2837 break;
2838 }
2839
2840 *nspname_p = schemaname;
2841 *objname_p = objname;
2842}
2843
2844/*
2845 * LookupNamespaceNoError
2846 * Look up a schema name.
2847 *
2848 * Returns the namespace OID, or InvalidOid if not found.
2849 *
2850 * Note this does NOT perform any permissions check --- callers are
2851 * responsible for being sure that an appropriate check is made.
2852 * In the majority of cases LookupExplicitNamespace is preferable.
2853 */
2854Oid
2855LookupNamespaceNoError(const char *nspname)
2856{
2857 /* check for pg_temp alias */
2858 if (strcmp(nspname, "pg_temp") == 0)
2859 {
2860 if (OidIsValid(myTempNamespace))
2861 {
2862 InvokeNamespaceSearchHook(myTempNamespace, true);
2863 return myTempNamespace;
2864 }
2865
2866 /*
2867 * Since this is used only for looking up existing objects, there is
2868 * no point in trying to initialize the temp namespace here; and doing
2869 * so might create problems for some callers. Just report "not found".
2870 */
2871 return InvalidOid;
2872 }
2873
2874 return get_namespace_oid(nspname, true);
2875}
2876
2877/*
2878 * LookupExplicitNamespace
2879 * Process an explicitly-specified schema name: look up the schema
2880 * and verify we have USAGE (lookup) rights in it.
2881 *
2882 * Returns the namespace OID
2883 */
2884Oid
2885LookupExplicitNamespace(const char *nspname, bool missing_ok)
2886{
2887 Oid namespaceId;
2888 AclResult aclresult;
2889
2890 /* check for pg_temp alias */
2891 if (strcmp(nspname, "pg_temp") == 0)
2892 {
2893 if (OidIsValid(myTempNamespace))
2894 return myTempNamespace;
2895
2896 /*
2897 * Since this is used only for looking up existing objects, there is
2898 * no point in trying to initialize the temp namespace here; and doing
2899 * so might create problems for some callers --- just fall through.
2900 */
2901 }
2902
2903 namespaceId = get_namespace_oid(nspname, missing_ok);
2904 if (missing_ok && !OidIsValid(namespaceId))
2905 return InvalidOid;
2906
2907 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
2908 if (aclresult != ACLCHECK_OK)
2909 aclcheck_error(aclresult, OBJECT_SCHEMA,
2910 nspname);
2911 /* Schema search hook for this lookup */
2912 InvokeNamespaceSearchHook(namespaceId, true);
2913
2914 return namespaceId;
2915}
2916
2917/*
2918 * LookupCreationNamespace
2919 * Look up the schema and verify we have CREATE rights on it.
2920 *
2921 * This is just like LookupExplicitNamespace except for the different
2922 * permission check, and that we are willing to create pg_temp if needed.
2923 *
2924 * Note: calling this may result in a CommandCounterIncrement operation,
2925 * if we have to create or clean out the temp namespace.
2926 */
2927Oid
2928LookupCreationNamespace(const char *nspname)
2929{
2930 Oid namespaceId;
2931 AclResult aclresult;
2932
2933 /* check for pg_temp alias */
2934 if (strcmp(nspname, "pg_temp") == 0)
2935 {
2936 /* Initialize temp namespace */
2937 AccessTempTableNamespace(false);
2938 return myTempNamespace;
2939 }
2940
2941 namespaceId = get_namespace_oid(nspname, false);
2942
2943 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
2944 if (aclresult != ACLCHECK_OK)
2945 aclcheck_error(aclresult, OBJECT_SCHEMA,
2946 nspname);
2947
2948 return namespaceId;
2949}
2950
2951/*
2952 * Common checks on switching namespaces.
2953 *
2954 * We complain if either the old or new namespaces is a temporary schema
2955 * (or temporary toast schema), or if either the old or new namespaces is the
2956 * TOAST schema.
2957 */
2958void
2959CheckSetNamespace(Oid oldNspOid, Oid nspOid)
2960{
2961 /* disallow renaming into or out of temp schemas */
2962 if (isAnyTempNamespace(nspOid) || isAnyTempNamespace(oldNspOid))
2963 ereport(ERROR,
2964 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2965 errmsg("cannot move objects into or out of temporary schemas")));
2966
2967 /* same for TOAST schema */
2968 if (nspOid == PG_TOAST_NAMESPACE || oldNspOid == PG_TOAST_NAMESPACE)
2969 ereport(ERROR,
2970 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
2971 errmsg("cannot move objects into or out of TOAST schema")));
2972}
2973
2974/*
2975 * QualifiedNameGetCreationNamespace
2976 * Given a possibly-qualified name for an object (in List-of-Values
2977 * format), determine what namespace the object should be created in.
2978 * Also extract and return the object name (last component of list).
2979 *
2980 * Note: this does not apply any permissions check. Callers must check
2981 * for CREATE rights on the selected namespace when appropriate.
2982 *
2983 * Note: calling this may result in a CommandCounterIncrement operation,
2984 * if we have to create or clean out the temp namespace.
2985 */
2986Oid
2987QualifiedNameGetCreationNamespace(List *names, char **objname_p)
2988{
2989 char *schemaname;
2990 Oid namespaceId;
2991
2992 /* deconstruct the name list */
2993 DeconstructQualifiedName(names, &schemaname, objname_p);
2994
2995 if (schemaname)
2996 {
2997 /* check for pg_temp alias */
2998 if (strcmp(schemaname, "pg_temp") == 0)
2999 {
3000 /* Initialize temp namespace */
3001 AccessTempTableNamespace(false);
3002 return myTempNamespace;
3003 }
3004 /* use exact schema given */
3005 namespaceId = get_namespace_oid(schemaname, false);
3006 /* we do not check for USAGE rights here! */
3007 }
3008 else
3009 {
3010 /* use the default creation namespace */
3011 recomputeNamespacePath();
3012 if (activeTempCreationPending)
3013 {
3014 /* Need to initialize temp namespace */
3015 AccessTempTableNamespace(true);
3016 return myTempNamespace;
3017 }
3018 namespaceId = activeCreationNamespace;
3019 if (!OidIsValid(namespaceId))
3020 ereport(ERROR,
3021 (errcode(ERRCODE_UNDEFINED_SCHEMA),
3022 errmsg("no schema has been selected to create in")));
3023 }
3024
3025 return namespaceId;
3026}
3027
3028/*
3029 * get_namespace_oid - given a namespace name, look up the OID
3030 *
3031 * If missing_ok is false, throw an error if namespace name not found. If
3032 * true, just return InvalidOid.
3033 */
3034Oid
3035get_namespace_oid(const char *nspname, bool missing_ok)
3036{
3037 Oid oid;
3038
3039 oid = GetSysCacheOid1(NAMESPACENAME, Anum_pg_namespace_oid,
3040 CStringGetDatum(nspname));
3041 if (!OidIsValid(oid) && !missing_ok)
3042 ereport(ERROR,
3043 (errcode(ERRCODE_UNDEFINED_SCHEMA),
3044 errmsg("schema \"%s\" does not exist", nspname)));
3045
3046 return oid;
3047}
3048
3049/*
3050 * makeRangeVarFromNameList
3051 * Utility routine to convert a qualified-name list into RangeVar form.
3052 */
3053RangeVar *
3054makeRangeVarFromNameList(List *names)
3055{
3056 RangeVar *rel = makeRangeVar(NULL, NULL, -1);
3057
3058 switch (list_length(names))
3059 {
3060 case 1:
3061 rel->relname = strVal(linitial(names));
3062 break;
3063 case 2:
3064 rel->schemaname = strVal(linitial(names));
3065 rel->relname = strVal(lsecond(names));
3066 break;
3067 case 3:
3068 rel->catalogname = strVal(linitial(names));
3069 rel->schemaname = strVal(lsecond(names));
3070 rel->relname = strVal(lthird(names));
3071 break;
3072 default:
3073 ereport(ERROR,
3074 (errcode(ERRCODE_SYNTAX_ERROR),
3075 errmsg("improper relation name (too many dotted names): %s",
3076 NameListToString(names))));
3077 break;
3078 }
3079
3080 return rel;
3081}
3082
3083/*
3084 * NameListToString
3085 * Utility routine to convert a qualified-name list into a string.
3086 *
3087 * This is used primarily to form error messages, and so we do not quote
3088 * the list elements, for the sake of legibility.
3089 *
3090 * In most scenarios the list elements should always be Value strings,
3091 * but we also allow A_Star for the convenience of ColumnRef processing.
3092 */
3093char *
3094NameListToString(List *names)
3095{
3096 StringInfoData string;
3097 ListCell *l;
3098
3099 initStringInfo(&string);
3100
3101 foreach(l, names)
3102 {
3103 Node *name = (Node *) lfirst(l);
3104
3105 if (l != list_head(names))
3106 appendStringInfoChar(&string, '.');
3107
3108 if (IsA(name, String))
3109 appendStringInfoString(&string, strVal(name));
3110 else if (IsA(name, A_Star))
3111 appendStringInfoChar(&string, '*');
3112 else
3113 elog(ERROR, "unexpected node type in name list: %d",
3114 (int) nodeTag(name));
3115 }
3116
3117 return string.data;
3118}
3119
3120/*
3121 * NameListToQuotedString
3122 * Utility routine to convert a qualified-name list into a string.
3123 *
3124 * Same as above except that names will be double-quoted where necessary,
3125 * so the string could be re-parsed (eg, by textToQualifiedNameList).
3126 */
3127char *
3128NameListToQuotedString(List *names)
3129{
3130 StringInfoData string;
3131 ListCell *l;
3132
3133 initStringInfo(&string);
3134
3135 foreach(l, names)
3136 {
3137 if (l != list_head(names))
3138 appendStringInfoChar(&string, '.');
3139 appendStringInfoString(&string, quote_identifier(strVal(lfirst(l))));
3140 }
3141
3142 return string.data;
3143}
3144
3145/*
3146 * isTempNamespace - is the given namespace my temporary-table namespace?
3147 */
3148bool
3149isTempNamespace(Oid namespaceId)
3150{
3151 if (OidIsValid(myTempNamespace) && myTempNamespace == namespaceId)
3152 return true;
3153 return false;
3154}
3155
3156/*
3157 * isTempToastNamespace - is the given namespace my temporary-toast-table
3158 * namespace?
3159 */
3160bool
3161isTempToastNamespace(Oid namespaceId)
3162{
3163 if (OidIsValid(myTempToastNamespace) && myTempToastNamespace == namespaceId)
3164 return true;
3165 return false;
3166}
3167
3168/*
3169 * isTempOrTempToastNamespace - is the given namespace my temporary-table
3170 * namespace or my temporary-toast-table namespace?
3171 */
3172bool
3173isTempOrTempToastNamespace(Oid namespaceId)
3174{
3175 if (OidIsValid(myTempNamespace) &&
3176 (myTempNamespace == namespaceId || myTempToastNamespace == namespaceId))
3177 return true;
3178 return false;
3179}
3180
3181/*
3182 * isAnyTempNamespace - is the given namespace a temporary-table namespace
3183 * (either my own, or another backend's)? Temporary-toast-table namespaces
3184 * are included, too.
3185 */
3186bool
3187isAnyTempNamespace(Oid namespaceId)
3188{
3189 bool result;
3190 char *nspname;
3191
3192 /* True if the namespace name starts with "pg_temp_" or "pg_toast_temp_" */
3193 nspname = get_namespace_name(namespaceId);
3194 if (!nspname)
3195 return false; /* no such namespace? */
3196 result = (strncmp(nspname, "pg_temp_", 8) == 0) ||
3197 (strncmp(nspname, "pg_toast_temp_", 14) == 0);
3198 pfree(nspname);
3199 return result;
3200}
3201
3202/*
3203 * isOtherTempNamespace - is the given namespace some other backend's
3204 * temporary-table namespace (including temporary-toast-table namespaces)?
3205 *
3206 * Note: for most purposes in the C code, this function is obsolete. Use
3207 * RELATION_IS_OTHER_TEMP() instead to detect non-local temp relations.
3208 */
3209bool
3210isOtherTempNamespace(Oid namespaceId)
3211{
3212 /* If it's my own temp namespace, say "false" */
3213 if (isTempOrTempToastNamespace(namespaceId))
3214 return false;
3215 /* Else, if it's any temp namespace, say "true" */
3216 return isAnyTempNamespace(namespaceId);
3217}
3218
3219/*
3220 * isTempNamespaceInUse - is the given namespace owned and actively used
3221 * by a backend?
3222 *
3223 * Note: this can be used while scanning relations in pg_class to detect
3224 * orphaned temporary tables or namespaces with a backend connected to a
3225 * given database. The result may be out of date quickly, so the caller
3226 * must be careful how to handle this information.
3227 */
3228bool
3229isTempNamespaceInUse(Oid namespaceId)
3230{
3231 PGPROC *proc;
3232 int backendId;
3233
3234 Assert(OidIsValid(MyDatabaseId));
3235
3236 backendId = GetTempNamespaceBackendId(namespaceId);
3237
3238 if (backendId == InvalidBackendId ||
3239 backendId == MyBackendId)
3240 return false;
3241
3242 /* Is the backend alive? */
3243 proc = BackendIdGetProc(backendId);
3244 if (proc == NULL)
3245 return false;
3246
3247 /* Is the backend connected to the same database we are looking at? */
3248 if (proc->databaseId != MyDatabaseId)
3249 return false;
3250
3251 /* Does the backend own the temporary namespace? */
3252 if (proc->tempNamespaceId != namespaceId)
3253 return false;
3254
3255 /* all good to go */
3256 return true;
3257}
3258
3259/*
3260 * GetTempNamespaceBackendId - if the given namespace is a temporary-table
3261 * namespace (either my own, or another backend's), return the BackendId
3262 * that owns it. Temporary-toast-table namespaces are included, too.
3263 * If it isn't a temp namespace, return InvalidBackendId.
3264 */
3265int
3266GetTempNamespaceBackendId(Oid namespaceId)
3267{
3268 int result;
3269 char *nspname;
3270
3271 /* See if the namespace name starts with "pg_temp_" or "pg_toast_temp_" */
3272 nspname = get_namespace_name(namespaceId);
3273 if (!nspname)
3274 return InvalidBackendId; /* no such namespace? */
3275 if (strncmp(nspname, "pg_temp_", 8) == 0)
3276 result = atoi(nspname + 8);
3277 else if (strncmp(nspname, "pg_toast_temp_", 14) == 0)
3278 result = atoi(nspname + 14);
3279 else
3280 result = InvalidBackendId;
3281 pfree(nspname);
3282 return result;
3283}
3284
3285/*
3286 * GetTempToastNamespace - get the OID of my temporary-toast-table namespace,
3287 * which must already be assigned. (This is only used when creating a toast
3288 * table for a temp table, so we must have already done InitTempTableNamespace)
3289 */
3290Oid
3291GetTempToastNamespace(void)
3292{
3293 Assert(OidIsValid(myTempToastNamespace));
3294 return myTempToastNamespace;
3295}
3296
3297
3298/*
3299 * GetTempNamespaceState - fetch status of session's temporary namespace
3300 *
3301 * This is used for conveying state to a parallel worker, and is not meant
3302 * for general-purpose access.
3303 */
3304void
3305GetTempNamespaceState(Oid *tempNamespaceId, Oid *tempToastNamespaceId)
3306{
3307 /* Return namespace OIDs, or 0 if session has not created temp namespace */
3308 *tempNamespaceId = myTempNamespace;
3309 *tempToastNamespaceId = myTempToastNamespace;
3310}
3311
3312/*
3313 * SetTempNamespaceState - set status of session's temporary namespace
3314 *
3315 * This is used for conveying state to a parallel worker, and is not meant for
3316 * general-purpose access. By transferring these namespace OIDs to workers,
3317 * we ensure they will have the same notion of the search path as their leader
3318 * does.
3319 */
3320void
3321SetTempNamespaceState(Oid tempNamespaceId, Oid tempToastNamespaceId)
3322{
3323 /* Worker should not have created its own namespaces ... */
3324 Assert(myTempNamespace == InvalidOid);
3325 Assert(myTempToastNamespace == InvalidOid);
3326 Assert(myTempNamespaceSubID == InvalidSubTransactionId);
3327
3328 /* Assign same namespace OIDs that leader has */
3329 myTempNamespace = tempNamespaceId;
3330 myTempToastNamespace = tempToastNamespaceId;
3331
3332 /*
3333 * It's fine to leave myTempNamespaceSubID == InvalidSubTransactionId.
3334 * Even if the namespace is new so far as the leader is concerned, it's
3335 * not new to the worker, and we certainly wouldn't want the worker trying
3336 * to destroy it.
3337 */
3338
3339 baseSearchPathValid = false; /* may need to rebuild list */
3340}
3341
3342
3343/*
3344 * GetOverrideSearchPath - fetch current search path definition in form
3345 * used by PushOverrideSearchPath.
3346 *
3347 * The result structure is allocated in the specified memory context
3348 * (which might or might not be equal to CurrentMemoryContext); but any
3349 * junk created by revalidation calculations will be in CurrentMemoryContext.
3350 */
3351OverrideSearchPath *
3352GetOverrideSearchPath(MemoryContext context)
3353{
3354 OverrideSearchPath *result;
3355 List *schemas;
3356 MemoryContext oldcxt;
3357
3358 recomputeNamespacePath();
3359
3360 oldcxt = MemoryContextSwitchTo(context);
3361
3362 result = (OverrideSearchPath *) palloc0(sizeof(OverrideSearchPath));
3363 schemas = list_copy(activeSearchPath);
3364 while (schemas && linitial_oid(schemas) != activeCreationNamespace)
3365 {
3366 if (linitial_oid(schemas) == myTempNamespace)
3367 result->addTemp = true;
3368 else
3369 {
3370 Assert(linitial_oid(schemas) == PG_CATALOG_NAMESPACE);
3371 result->addCatalog = true;
3372 }
3373 schemas = list_delete_first(schemas);
3374 }
3375 result->schemas = schemas;
3376
3377 MemoryContextSwitchTo(oldcxt);
3378
3379 return result;
3380}
3381
3382/*
3383 * CopyOverrideSearchPath - copy the specified OverrideSearchPath.
3384 *
3385 * The result structure is allocated in CurrentMemoryContext.
3386 */
3387OverrideSearchPath *
3388CopyOverrideSearchPath(OverrideSearchPath *path)
3389{
3390 OverrideSearchPath *result;
3391
3392 result = (OverrideSearchPath *) palloc(sizeof(OverrideSearchPath));
3393 result->schemas = list_copy(path->schemas);
3394 result->addCatalog = path->addCatalog;
3395 result->addTemp = path->addTemp;
3396
3397 return result;
3398}
3399
3400/*
3401 * OverrideSearchPathMatchesCurrent - does path match current setting?
3402 */
3403bool
3404OverrideSearchPathMatchesCurrent(OverrideSearchPath *path)
3405{
3406 ListCell *lc,
3407 *lcp;
3408
3409 recomputeNamespacePath();
3410
3411 /* We scan down the activeSearchPath to see if it matches the input. */
3412 lc = list_head(activeSearchPath);
3413
3414 /* If path->addTemp, first item should be my temp namespace. */
3415 if (path->addTemp)
3416 {
3417 if (lc && lfirst_oid(lc) == myTempNamespace)
3418 lc = lnext(lc);
3419 else
3420 return false;
3421 }
3422 /* If path->addCatalog, next item should be pg_catalog. */
3423 if (path->addCatalog)
3424 {
3425 if (lc && lfirst_oid(lc) == PG_CATALOG_NAMESPACE)
3426 lc = lnext(lc);
3427 else
3428 return false;
3429 }
3430 /* We should now be looking at the activeCreationNamespace. */
3431 if (activeCreationNamespace != (lc ? lfirst_oid(lc) : InvalidOid))
3432 return false;
3433 /* The remainder of activeSearchPath should match path->schemas. */
3434 foreach(lcp, path->schemas)
3435 {
3436 if (lc && lfirst_oid(lc) == lfirst_oid(lcp))
3437 lc = lnext(lc);
3438 else
3439 return false;
3440 }
3441 if (lc)
3442 return false;
3443 return true;
3444}
3445
3446/*
3447 * PushOverrideSearchPath - temporarily override the search path
3448 *
3449 * We allow nested overrides, hence the push/pop terminology. The GUC
3450 * search_path variable is ignored while an override is active.
3451 *
3452 * It's possible that newpath->useTemp is set but there is no longer any
3453 * active temp namespace, if the path was saved during a transaction that
3454 * created a temp namespace and was later rolled back. In that case we just
3455 * ignore useTemp. A plausible alternative would be to create a new temp
3456 * namespace, but for existing callers that's not necessary because an empty
3457 * temp namespace wouldn't affect their results anyway.
3458 *
3459 * It's also worth noting that other schemas listed in newpath might not
3460 * exist anymore either. We don't worry about this because OIDs that match
3461 * no existing namespace will simply not produce any hits during searches.
3462 */
3463void
3464PushOverrideSearchPath(OverrideSearchPath *newpath)
3465{
3466 OverrideStackEntry *entry;
3467 List *oidlist;
3468 Oid firstNS;
3469 MemoryContext oldcxt;
3470
3471 /*
3472 * Copy the list for safekeeping, and insert implicitly-searched
3473 * namespaces as needed. This code should track recomputeNamespacePath.
3474 */
3475 oldcxt = MemoryContextSwitchTo(TopMemoryContext);
3476
3477 oidlist = list_copy(newpath->schemas);
3478
3479 /*
3480 * Remember the first member of the explicit list.
3481 */
3482 if (oidlist == NIL)
3483 firstNS = InvalidOid;
3484 else
3485 firstNS = linitial_oid(oidlist);
3486
3487 /*
3488 * Add any implicitly-searched namespaces to the list. Note these go on
3489 * the front, not the back; also notice that we do not check USAGE
3490 * permissions for these.
3491 */
3492 if (newpath->addCatalog)
3493 oidlist = lcons_oid(PG_CATALOG_NAMESPACE, oidlist);
3494
3495 if (newpath->addTemp && OidIsValid(myTempNamespace))
3496 oidlist = lcons_oid(myTempNamespace, oidlist);
3497
3498 /*
3499 * Build the new stack entry, then insert it at the head of the list.
3500 */
3501 entry = (OverrideStackEntry *) palloc(sizeof(OverrideStackEntry));
3502 entry->searchPath = oidlist;
3503 entry->creationNamespace = firstNS;
3504 entry->nestLevel = GetCurrentTransactionNestLevel();
3505
3506 overrideStack = lcons(entry, overrideStack);
3507
3508 /* And make it active. */
3509 activeSearchPath = entry->searchPath;
3510 activeCreationNamespace = entry->creationNamespace;
3511 activeTempCreationPending = false; /* XXX is this OK? */
3512
3513 MemoryContextSwitchTo(oldcxt);
3514}
3515
3516/*
3517 * PopOverrideSearchPath - undo a previous PushOverrideSearchPath
3518 *
3519 * Any push during a (sub)transaction will be popped automatically at abort.
3520 * But it's caller error if a push isn't popped in normal control flow.
3521 */
3522void
3523PopOverrideSearchPath(void)
3524{
3525 OverrideStackEntry *entry;
3526
3527 /* Sanity checks. */
3528 if (overrideStack == NIL)
3529 elog(ERROR, "bogus PopOverrideSearchPath call");
3530 entry = (OverrideStackEntry *) linitial(overrideStack);
3531 if (entry->nestLevel != GetCurrentTransactionNestLevel())
3532 elog(ERROR, "bogus PopOverrideSearchPath call");
3533
3534 /* Pop the stack and free storage. */
3535 overrideStack = list_delete_first(overrideStack);
3536 list_free(entry->searchPath);
3537 pfree(entry);
3538
3539 /* Activate the next level down. */
3540 if (overrideStack)
3541 {
3542 entry = (OverrideStackEntry *) linitial(overrideStack);
3543 activeSearchPath = entry->searchPath;
3544 activeCreationNamespace = entry->creationNamespace;
3545 activeTempCreationPending = false; /* XXX is this OK? */
3546 }
3547 else
3548 {
3549 /* If not baseSearchPathValid, this is useless but harmless */
3550 activeSearchPath = baseSearchPath;
3551 activeCreationNamespace = baseCreationNamespace;
3552 activeTempCreationPending = baseTempCreationPending;
3553 }
3554}
3555
3556
3557/*
3558 * get_collation_oid - find a collation by possibly qualified name
3559 *
3560 * Note that this will only find collations that work with the current
3561 * database's encoding.
3562 */
3563Oid
3564get_collation_oid(List *name, bool missing_ok)
3565{
3566 char *schemaname;
3567 char *collation_name;
3568 int32 dbencoding = GetDatabaseEncoding();
3569 Oid namespaceId;
3570 Oid colloid;
3571 ListCell *l;
3572
3573 /* deconstruct the name list */
3574 DeconstructQualifiedName(name, &schemaname, &collation_name);
3575
3576 if (schemaname)
3577 {
3578 /* use exact schema given */
3579 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
3580 if (missing_ok && !OidIsValid(namespaceId))
3581 return InvalidOid;
3582
3583 colloid = lookup_collation(collation_name, namespaceId, dbencoding);
3584 if (OidIsValid(colloid))
3585 return colloid;
3586 }
3587 else
3588 {
3589 /* search for it in search path */
3590 recomputeNamespacePath();
3591
3592 foreach(l, activeSearchPath)
3593 {
3594 namespaceId = lfirst_oid(l);
3595
3596 if (namespaceId == myTempNamespace)
3597 continue; /* do not look in temp namespace */
3598
3599 colloid = lookup_collation(collation_name, namespaceId, dbencoding);
3600 if (OidIsValid(colloid))
3601 return colloid;
3602 }
3603 }
3604
3605 /* Not found in path */
3606 if (!missing_ok)
3607 ereport(ERROR,
3608 (errcode(ERRCODE_UNDEFINED_OBJECT),
3609 errmsg("collation \"%s\" for encoding \"%s\" does not exist",
3610 NameListToString(name), GetDatabaseEncodingName())));
3611 return InvalidOid;
3612}
3613
3614/*
3615 * get_conversion_oid - find a conversion by possibly qualified name
3616 */
3617Oid
3618get_conversion_oid(List *name, bool missing_ok)
3619{
3620 char *schemaname;
3621 char *conversion_name;
3622 Oid namespaceId;
3623 Oid conoid = InvalidOid;
3624 ListCell *l;
3625
3626 /* deconstruct the name list */
3627 DeconstructQualifiedName(name, &schemaname, &conversion_name);
3628
3629 if (schemaname)
3630 {
3631 /* use exact schema given */
3632 namespaceId = LookupExplicitNamespace(schemaname, missing_ok);
3633 if (missing_ok && !OidIsValid(namespaceId))
3634 conoid = InvalidOid;
3635 else
3636 conoid = GetSysCacheOid2(CONNAMENSP, Anum_pg_conversion_oid,
3637 PointerGetDatum(conversion_name),
3638 ObjectIdGetDatum(namespaceId));
3639 }
3640 else
3641 {
3642 /* search for it in search path */
3643 recomputeNamespacePath();
3644
3645 foreach(l, activeSearchPath)
3646 {
3647 namespaceId = lfirst_oid(l);
3648
3649 if (namespaceId == myTempNamespace)
3650 continue; /* do not look in temp namespace */
3651
3652 conoid = GetSysCacheOid2(CONNAMENSP, Anum_pg_conversion_oid,
3653 PointerGetDatum(conversion_name),
3654 ObjectIdGetDatum(namespaceId));
3655 if (OidIsValid(conoid))
3656 return conoid;
3657 }
3658 }
3659
3660 /* Not found in path */
3661 if (!OidIsValid(conoid) && !missing_ok)
3662 ereport(ERROR,
3663 (errcode(ERRCODE_UNDEFINED_OBJECT),
3664 errmsg("conversion \"%s\" does not exist",
3665 NameListToString(name))));
3666 return conoid;
3667}
3668
3669/*
3670 * FindDefaultConversionProc - find default encoding conversion proc
3671 */
3672Oid
3673FindDefaultConversionProc(int32 for_encoding, int32 to_encoding)
3674{
3675 Oid proc;
3676 ListCell *l;
3677
3678 recomputeNamespacePath();
3679
3680 foreach(l, activeSearchPath)
3681 {
3682 Oid namespaceId = lfirst_oid(l);
3683
3684 if (namespaceId == myTempNamespace)
3685 continue; /* do not look in temp namespace */
3686
3687 proc = FindDefaultConversion(namespaceId, for_encoding, to_encoding);
3688 if (OidIsValid(proc))
3689 return proc;
3690 }
3691
3692 /* Not found in path */
3693 return InvalidOid;
3694}
3695
3696/*
3697 * recomputeNamespacePath - recompute path derived variables if needed.
3698 */
3699static void
3700recomputeNamespacePath(void)
3701{
3702 Oid roleid = GetUserId();
3703 char *rawname;
3704 List *namelist;
3705 List *oidlist;
3706 List *newpath;
3707 ListCell *l;
3708 bool temp_missing;
3709 Oid firstNS;
3710 MemoryContext oldcxt;
3711
3712 /* Do nothing if an override search spec is active. */
3713 if (overrideStack)
3714 return;
3715
3716 /* Do nothing if path is already valid. */
3717 if (baseSearchPathValid && namespaceUser == roleid)
3718 return;
3719
3720 /* Need a modifiable copy of namespace_search_path string */
3721 rawname = pstrdup(namespace_search_path);
3722
3723 /* Parse string into list of identifiers */
3724 if (!SplitIdentifierString(rawname, ',', &namelist))
3725 {
3726 /* syntax error in name list */
3727 /* this should not happen if GUC checked check_search_path */
3728 elog(ERROR, "invalid list syntax");
3729 }
3730
3731 /*
3732 * Convert the list of names to a list of OIDs. If any names are not
3733 * recognizable or we don't have read access, just leave them out of the
3734 * list. (We can't raise an error, since the search_path setting has
3735 * already been accepted.) Don't make duplicate entries, either.
3736 */
3737 oidlist = NIL;
3738 temp_missing = false;
3739 foreach(l, namelist)
3740 {
3741 char *curname = (char *) lfirst(l);
3742 Oid namespaceId;
3743
3744 if (strcmp(curname, "$user") == 0)
3745 {
3746 /* $user --- substitute namespace matching user name, if any */
3747 HeapTuple tuple;
3748
3749 tuple = SearchSysCache1(AUTHOID, ObjectIdGetDatum(roleid));
3750 if (HeapTupleIsValid(tuple))
3751 {
3752 char *rname;
3753
3754 rname = NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname);
3755 namespaceId = get_namespace_oid(rname, true);
3756 ReleaseSysCache(tuple);
3757 if (OidIsValid(namespaceId) &&
3758 !list_member_oid(oidlist, namespaceId) &&
3759 pg_namespace_aclcheck(namespaceId, roleid,
3760 ACL_USAGE) == ACLCHECK_OK &&
3761 InvokeNamespaceSearchHook(namespaceId, false))
3762 oidlist = lappend_oid(oidlist, namespaceId);
3763 }
3764 }
3765 else if (strcmp(curname, "pg_temp") == 0)
3766 {
3767 /* pg_temp --- substitute temp namespace, if any */
3768 if (OidIsValid(myTempNamespace))
3769 {
3770 if (!list_member_oid(oidlist, myTempNamespace) &&
3771 InvokeNamespaceSearchHook(myTempNamespace, false))
3772 oidlist = lappend_oid(oidlist, myTempNamespace);
3773 }
3774 else
3775 {
3776 /* If it ought to be the creation namespace, set flag */
3777 if (oidlist == NIL)
3778 temp_missing = true;
3779 }
3780 }
3781 else
3782 {
3783 /* normal namespace reference */
3784 namespaceId = get_namespace_oid(curname, true);
3785 if (OidIsValid(namespaceId) &&
3786 !list_member_oid(oidlist, namespaceId) &&
3787 pg_namespace_aclcheck(namespaceId, roleid,
3788 ACL_USAGE) == ACLCHECK_OK &&
3789 InvokeNamespaceSearchHook(namespaceId, false))
3790 oidlist = lappend_oid(oidlist, namespaceId);
3791 }
3792 }
3793
3794 /*
3795 * Remember the first member of the explicit list. (Note: this is
3796 * nominally wrong if temp_missing, but we need it anyway to distinguish
3797 * explicit from implicit mention of pg_catalog.)
3798 */
3799 if (oidlist == NIL)
3800 firstNS = InvalidOid;
3801 else
3802 firstNS = linitial_oid(oidlist);
3803
3804 /*
3805 * Add any implicitly-searched namespaces to the list. Note these go on
3806 * the front, not the back; also notice that we do not check USAGE
3807 * permissions for these.
3808 */
3809 if (!list_member_oid(oidlist, PG_CATALOG_NAMESPACE))
3810 oidlist = lcons_oid(PG_CATALOG_NAMESPACE, oidlist);
3811
3812 if (OidIsValid(myTempNamespace) &&
3813 !list_member_oid(oidlist, myTempNamespace))
3814 oidlist = lcons_oid(myTempNamespace, oidlist);
3815
3816 /*
3817 * Now that we've successfully built the new list of namespace OIDs, save
3818 * it in permanent storage.
3819 */
3820 oldcxt = MemoryContextSwitchTo(TopMemoryContext);
3821 newpath = list_copy(oidlist);
3822 MemoryContextSwitchTo(oldcxt);
3823
3824 /* Now safe to assign to state variables. */
3825 list_free(baseSearchPath);
3826 baseSearchPath = newpath;
3827 baseCreationNamespace = firstNS;
3828 baseTempCreationPending = temp_missing;
3829
3830 /* Mark the path valid. */
3831 baseSearchPathValid = true;
3832 namespaceUser = roleid;
3833
3834 /* And make it active. */
3835 activeSearchPath = baseSearchPath;
3836 activeCreationNamespace = baseCreationNamespace;
3837 activeTempCreationPending = baseTempCreationPending;
3838
3839 /* Clean up. */
3840 pfree(rawname);
3841 list_free(namelist);
3842 list_free(oidlist);
3843}
3844
3845/*
3846 * AccessTempTableNamespace
3847 * Provide access to a temporary namespace, potentially creating it
3848 * if not present yet. This routine registers if the namespace gets
3849 * in use in this transaction. 'force' can be set to true to allow
3850 * the caller to enforce the creation of the temporary namespace for
3851 * use in this backend, which happens if its creation is pending.
3852 */
3853static void
3854AccessTempTableNamespace(bool force)
3855{
3856 /*
3857 * Make note that this temporary namespace has been accessed in this
3858 * transaction.
3859 */
3860 MyXactFlags |= XACT_FLAGS_ACCESSEDTEMPNAMESPACE;
3861
3862 /*
3863 * If the caller attempting to access a temporary schema expects the
3864 * creation of the namespace to be pending and should be enforced, then go
3865 * through the creation.
3866 */
3867 if (!force && OidIsValid(myTempNamespace))
3868 return;
3869
3870 /*
3871 * The temporary tablespace does not exist yet and is wanted, so
3872 * initialize it.
3873 */
3874 InitTempTableNamespace();
3875}
3876
3877/*
3878 * InitTempTableNamespace
3879 * Initialize temp table namespace on first use in a particular backend
3880 */
3881static void
3882InitTempTableNamespace(void)
3883{
3884 char namespaceName[NAMEDATALEN];
3885 Oid namespaceId;
3886 Oid toastspaceId;
3887
3888 Assert(!OidIsValid(myTempNamespace));
3889
3890 /*
3891 * First, do permission check to see if we are authorized to make temp
3892 * tables. We use a nonstandard error message here since "databasename:
3893 * permission denied" might be a tad cryptic.
3894 *
3895 * Note that ACL_CREATE_TEMP rights are rechecked in pg_namespace_aclmask;
3896 * that's necessary since current user ID could change during the session.
3897 * But there's no need to make the namespace in the first place until a
3898 * temp table creation request is made by someone with appropriate rights.
3899 */
3900 if (pg_database_aclcheck(MyDatabaseId, GetUserId(),
3901 ACL_CREATE_TEMP) != ACLCHECK_OK)
3902 ereport(ERROR,
3903 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
3904 errmsg("permission denied to create temporary tables in database \"%s\"",
3905 get_database_name(MyDatabaseId))));
3906
3907 /*
3908 * Do not allow a Hot Standby session to make temp tables. Aside from
3909 * problems with modifying the system catalogs, there is a naming
3910 * conflict: pg_temp_N belongs to the session with BackendId N on the
3911 * master, not to a hot standby session with the same BackendId. We
3912 * should not be able to get here anyway due to XactReadOnly checks, but
3913 * let's just make real sure. Note that this also backstops various
3914 * operations that allow XactReadOnly transactions to modify temp tables;
3915 * they'd need RecoveryInProgress checks if not for this.
3916 */
3917 if (RecoveryInProgress())
3918 ereport(ERROR,
3919 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
3920 errmsg("cannot create temporary tables during recovery")));
3921
3922 /* Parallel workers can't create temporary tables, either. */
3923 if (IsParallelWorker())
3924 ereport(ERROR,
3925 (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
3926 errmsg("cannot create temporary tables during a parallel operation")));
3927
3928 snprintf(namespaceName, sizeof(namespaceName), "pg_temp_%d", MyBackendId);
3929
3930 namespaceId = get_namespace_oid(namespaceName, true);
3931 if (!OidIsValid(namespaceId))
3932 {
3933 /*
3934 * First use of this temp namespace in this database; create it. The
3935 * temp namespaces are always owned by the superuser. We leave their
3936 * permissions at default --- i.e., no access except to superuser ---
3937 * to ensure that unprivileged users can't peek at other backends'
3938 * temp tables. This works because the places that access the temp
3939 * namespace for my own backend skip permissions checks on it.
3940 */
3941 namespaceId = NamespaceCreate(namespaceName, BOOTSTRAP_SUPERUSERID,
3942 true);
3943 /* Advance command counter to make namespace visible */
3944 CommandCounterIncrement();
3945 }
3946 else
3947 {
3948 /*
3949 * If the namespace already exists, clean it out (in case the former
3950 * owner crashed without doing so).
3951 */
3952 RemoveTempRelations(namespaceId);
3953 }
3954
3955 /*
3956 * If the corresponding toast-table namespace doesn't exist yet, create
3957 * it. (We assume there is no need to clean it out if it does exist, since
3958 * dropping a parent table should make its toast table go away.)
3959 */
3960 snprintf(namespaceName, sizeof(namespaceName), "pg_toast_temp_%d",
3961 MyBackendId);
3962
3963 toastspaceId = get_namespace_oid(namespaceName, true);
3964 if (!OidIsValid(toastspaceId))
3965 {
3966 toastspaceId = NamespaceCreate(namespaceName, BOOTSTRAP_SUPERUSERID,
3967 true);
3968 /* Advance command counter to make namespace visible */
3969 CommandCounterIncrement();
3970 }
3971
3972 /*
3973 * Okay, we've prepared the temp namespace ... but it's not committed yet,
3974 * so all our work could be undone by transaction rollback. Set flag for
3975 * AtEOXact_Namespace to know what to do.
3976 */
3977 myTempNamespace = namespaceId;
3978 myTempToastNamespace = toastspaceId;
3979
3980 /*
3981 * Mark MyProc as owning this namespace which other processes can use to
3982 * decide if a temporary namespace is in use or not. We assume that
3983 * assignment of namespaceId is an atomic operation. Even if it is not,
3984 * the temporary relation which resulted in the creation of this temporary
3985 * namespace is still locked until the current transaction commits, and
3986 * its pg_namespace row is not visible yet. However it does not matter:
3987 * this flag makes the namespace as being in use, so no objects created on
3988 * it would be removed concurrently.
3989 */
3990 MyProc->tempNamespaceId = namespaceId;
3991
3992 /* It should not be done already. */
3993 AssertState(myTempNamespaceSubID == InvalidSubTransactionId);
3994 myTempNamespaceSubID = GetCurrentSubTransactionId();
3995
3996 baseSearchPathValid = false; /* need to rebuild list */
3997}
3998
3999/*
4000 * End-of-transaction cleanup for namespaces.
4001 */
4002void
4003AtEOXact_Namespace(bool isCommit, bool parallel)
4004{
4005 /*
4006 * If we abort the transaction in which a temp namespace was selected,
4007 * we'll have to do any creation or cleanout work over again. So, just
4008 * forget the namespace entirely until next time. On the other hand, if
4009 * we commit then register an exit callback to clean out the temp tables
4010 * at backend shutdown. (We only want to register the callback once per
4011 * session, so this is a good place to do it.)
4012 */
4013 if (myTempNamespaceSubID != InvalidSubTransactionId && !parallel)
4014 {
4015 if (isCommit)
4016 before_shmem_exit(RemoveTempRelationsCallback, 0);
4017 else
4018 {
4019 myTempNamespace = InvalidOid;
4020 myTempToastNamespace = InvalidOid;
4021 baseSearchPathValid = false; /* need to rebuild list */
4022
4023 /*
4024 * Reset the temporary namespace flag in MyProc. We assume that
4025 * this operation is atomic.
4026 *
4027 * Because this transaction is aborting, the pg_namespace row is
4028 * not visible to anyone else anyway, but that doesn't matter:
4029 * it's not a problem if objects contained in this namespace are
4030 * removed concurrently.
4031 */
4032 MyProc->tempNamespaceId = InvalidOid;
4033 }
4034 myTempNamespaceSubID = InvalidSubTransactionId;
4035 }
4036
4037 /*
4038 * Clean up if someone failed to do PopOverrideSearchPath
4039 */
4040 if (overrideStack)
4041 {
4042 if (isCommit)
4043 elog(WARNING, "leaked override search path");
4044 while (overrideStack)
4045 {
4046 OverrideStackEntry *entry;
4047
4048 entry = (OverrideStackEntry *) linitial(overrideStack);
4049 overrideStack = list_delete_first(overrideStack);
4050 list_free(entry->searchPath);
4051 pfree(entry);
4052 }
4053 /* If not baseSearchPathValid, this is useless but harmless */
4054 activeSearchPath = baseSearchPath;
4055 activeCreationNamespace = baseCreationNamespace;
4056 activeTempCreationPending = baseTempCreationPending;
4057 }
4058}
4059
4060/*
4061 * AtEOSubXact_Namespace
4062 *
4063 * At subtransaction commit, propagate the temp-namespace-creation
4064 * flag to the parent subtransaction.
4065 *
4066 * At subtransaction abort, forget the flag if we set it up.
4067 */
4068void
4069AtEOSubXact_Namespace(bool isCommit, SubTransactionId mySubid,
4070 SubTransactionId parentSubid)
4071{
4072 OverrideStackEntry *entry;
4073
4074 if (myTempNamespaceSubID == mySubid)
4075 {
4076 if (isCommit)
4077 myTempNamespaceSubID = parentSubid;
4078 else
4079 {
4080 myTempNamespaceSubID = InvalidSubTransactionId;
4081 /* TEMP namespace creation failed, so reset state */
4082 myTempNamespace = InvalidOid;
4083 myTempToastNamespace = InvalidOid;
4084 baseSearchPathValid = false; /* need to rebuild list */
4085
4086 /*
4087 * Reset the temporary namespace flag in MyProc. We assume that
4088 * this operation is atomic.
4089 *
4090 * Because this subtransaction is aborting, the pg_namespace row
4091 * is not visible to anyone else anyway, but that doesn't matter:
4092 * it's not a problem if objects contained in this namespace are
4093 * removed concurrently.
4094 */
4095 MyProc->tempNamespaceId = InvalidOid;
4096 }
4097 }
4098
4099 /*
4100 * Clean up if someone failed to do PopOverrideSearchPath
4101 */
4102 while (overrideStack)
4103 {
4104 entry = (OverrideStackEntry *) linitial(overrideStack);
4105 if (entry->nestLevel < GetCurrentTransactionNestLevel())
4106 break;
4107 if (isCommit)
4108 elog(WARNING, "leaked override search path");
4109 overrideStack = list_delete_first(overrideStack);
4110 list_free(entry->searchPath);
4111 pfree(entry);
4112 }
4113
4114 /* Activate the next level down. */
4115 if (overrideStack)
4116 {
4117 entry = (OverrideStackEntry *) linitial(overrideStack);
4118 activeSearchPath = entry->searchPath;
4119 activeCreationNamespace = entry->creationNamespace;
4120 activeTempCreationPending = false; /* XXX is this OK? */
4121 }
4122 else
4123 {
4124 /* If not baseSearchPathValid, this is useless but harmless */
4125 activeSearchPath = baseSearchPath;
4126 activeCreationNamespace = baseCreationNamespace;
4127 activeTempCreationPending = baseTempCreationPending;
4128 }
4129}
4130
4131/*
4132 * Remove all relations in the specified temp namespace.
4133 *
4134 * This is called at backend shutdown (if we made any temp relations).
4135 * It is also called when we begin using a pre-existing temp namespace,
4136 * in order to clean out any relations that might have been created by
4137 * a crashed backend.
4138 */
4139static void
4140RemoveTempRelations(Oid tempNamespaceId)
4141{
4142 ObjectAddress object;
4143
4144 /*
4145 * We want to get rid of everything in the target namespace, but not the
4146 * namespace itself (deleting it only to recreate it later would be a
4147 * waste of cycles). Hence, specify SKIP_ORIGINAL. It's also an INTERNAL
4148 * deletion, and we want to not drop any extensions that might happen to
4149 * own temp objects.
4150 */
4151 object.classId = NamespaceRelationId;
4152 object.objectId = tempNamespaceId;
4153 object.objectSubId = 0;
4154
4155 performDeletion(&object, DROP_CASCADE,
4156 PERFORM_DELETION_INTERNAL |
4157 PERFORM_DELETION_QUIETLY |
4158 PERFORM_DELETION_SKIP_ORIGINAL |
4159 PERFORM_DELETION_SKIP_EXTENSIONS);
4160}
4161
4162/*
4163 * Callback to remove temp relations at backend exit.
4164 */
4165static void
4166RemoveTempRelationsCallback(int code, Datum arg)
4167{
4168 if (OidIsValid(myTempNamespace)) /* should always be true */
4169 {
4170 /* Need to ensure we have a usable transaction. */
4171 AbortOutOfAnyTransaction();
4172 StartTransactionCommand();
4173
4174 RemoveTempRelations(myTempNamespace);
4175
4176 CommitTransactionCommand();
4177 }
4178}
4179
4180/*
4181 * Remove all temp tables from the temporary namespace.
4182 */
4183void
4184ResetTempTableNamespace(void)
4185{
4186 if (OidIsValid(myTempNamespace))
4187 RemoveTempRelations(myTempNamespace);
4188}
4189
4190
4191/*
4192 * Routines for handling the GUC variable 'search_path'.
4193 */
4194
4195/* check_hook: validate new search_path value */
4196bool
4197check_search_path(char **newval, void **extra, GucSource source)
4198{
4199 char *rawname;
4200 List *namelist;
4201
4202 /* Need a modifiable copy of string */
4203 rawname = pstrdup(*newval);
4204
4205 /* Parse string into list of identifiers */
4206 if (!SplitIdentifierString(rawname, ',', &namelist))
4207 {
4208 /* syntax error in name list */
4209 GUC_check_errdetail("List syntax is invalid.");
4210 pfree(rawname);
4211 list_free(namelist);
4212 return false;
4213 }
4214
4215 /*
4216 * We used to try to check that the named schemas exist, but there are
4217 * many valid use-cases for having search_path settings that include
4218 * schemas that don't exist; and often, we are not inside a transaction
4219 * here and so can't consult the system catalogs anyway. So now, the only
4220 * requirement is syntactic validity of the identifier list.
4221 */
4222
4223 pfree(rawname);
4224 list_free(namelist);
4225
4226 return true;
4227}
4228
4229/* assign_hook: do extra actions as needed */
4230void
4231assign_search_path(const char *newval, void *extra)
4232{
4233 /*
4234 * We mark the path as needing recomputation, but don't do anything until
4235 * it's needed. This avoids trying to do database access during GUC
4236 * initialization, or outside a transaction.
4237 */
4238 baseSearchPathValid = false;
4239}
4240
4241/*
4242 * InitializeSearchPath: initialize module during InitPostgres.
4243 *
4244 * This is called after we are up enough to be able to do catalog lookups.
4245 */
4246void
4247InitializeSearchPath(void)
4248{
4249 if (IsBootstrapProcessingMode())
4250 {
4251 /*
4252 * In bootstrap mode, the search path must be 'pg_catalog' so that
4253 * tables are created in the proper namespace; ignore the GUC setting.
4254 */
4255 MemoryContext oldcxt;
4256
4257 oldcxt = MemoryContextSwitchTo(TopMemoryContext);
4258 baseSearchPath = list_make1_oid(PG_CATALOG_NAMESPACE);
4259 MemoryContextSwitchTo(oldcxt);
4260 baseCreationNamespace = PG_CATALOG_NAMESPACE;
4261 baseTempCreationPending = false;
4262 baseSearchPathValid = true;
4263 namespaceUser = GetUserId();
4264 activeSearchPath = baseSearchPath;
4265 activeCreationNamespace = baseCreationNamespace;
4266 activeTempCreationPending = baseTempCreationPending;
4267 }
4268 else
4269 {
4270 /*
4271 * In normal mode, arrange for a callback on any syscache invalidation
4272 * of pg_namespace rows.
4273 */
4274 CacheRegisterSyscacheCallback(NAMESPACEOID,
4275 NamespaceCallback,
4276 (Datum) 0);
4277 /* Force search path to be recomputed on next use */
4278 baseSearchPathValid = false;
4279 }
4280}
4281
4282/*
4283 * NamespaceCallback
4284 * Syscache inval callback function
4285 */
4286static void
4287NamespaceCallback(Datum arg, int cacheid, uint32 hashvalue)
4288{
4289 /* Force search path to be recomputed on next use */
4290 baseSearchPathValid = false;
4291}
4292
4293/*
4294 * Fetch the active search path. The return value is a palloc'ed list
4295 * of OIDs; the caller is responsible for freeing this storage as
4296 * appropriate.
4297 *
4298 * The returned list includes the implicitly-prepended namespaces only if
4299 * includeImplicit is true.
4300 *
4301 * Note: calling this may result in a CommandCounterIncrement operation,
4302 * if we have to create or clean out the temp namespace.
4303 */
4304List *
4305fetch_search_path(bool includeImplicit)
4306{
4307 List *result;
4308
4309 recomputeNamespacePath();
4310
4311 /*
4312 * If the temp namespace should be first, force it to exist. This is so
4313 * that callers can trust the result to reflect the actual default
4314 * creation namespace. It's a bit bogus to do this here, since
4315 * current_schema() is supposedly a stable function without side-effects,
4316 * but the alternatives seem worse.
4317 */
4318 if (activeTempCreationPending)
4319 {
4320 AccessTempTableNamespace(true);
4321 recomputeNamespacePath();
4322 }
4323
4324 result = list_copy(activeSearchPath);
4325 if (!includeImplicit)
4326 {
4327 while (result && linitial_oid(result) != activeCreationNamespace)
4328 result = list_delete_first(result);
4329 }
4330
4331 return result;
4332}
4333
4334/*
4335 * Fetch the active search path into a caller-allocated array of OIDs.
4336 * Returns the number of path entries. (If this is more than sarray_len,
4337 * then the data didn't fit and is not all stored.)
4338 *
4339 * The returned list always includes the implicitly-prepended namespaces,
4340 * but never includes the temp namespace. (This is suitable for existing
4341 * users, which would want to ignore the temp namespace anyway.) This
4342 * definition allows us to not worry about initializing the temp namespace.
4343 */
4344int
4345fetch_search_path_array(Oid *sarray, int sarray_len)
4346{
4347 int count = 0;
4348 ListCell *l;
4349
4350 recomputeNamespacePath();
4351
4352 foreach(l, activeSearchPath)
4353 {
4354 Oid namespaceId = lfirst_oid(l);
4355
4356 if (namespaceId == myTempNamespace)
4357 continue; /* do not include temp namespace */
4358
4359 if (count < sarray_len)
4360 sarray[count] = namespaceId;
4361 count++;
4362 }
4363
4364 return count;
4365}
4366
4367
4368/*
4369 * Export the FooIsVisible functions as SQL-callable functions.
4370 *
4371 * Note: as of Postgres 8.4, these will silently return NULL if called on
4372 * a nonexistent object OID, rather than failing. This is to avoid race
4373 * condition errors when a query that's scanning a catalog using an MVCC
4374 * snapshot uses one of these functions. The underlying IsVisible functions
4375 * always use an up-to-date snapshot and so might see the object as already
4376 * gone when it's still visible to the transaction snapshot. (There is no race
4377 * condition in the current coding because we don't accept sinval messages
4378 * between the SearchSysCacheExists test and the subsequent lookup.)
4379 */
4380
4381Datum
4382pg_table_is_visible(PG_FUNCTION_ARGS)
4383{
4384 Oid oid = PG_GETARG_OID(0);
4385
4386 if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(oid)))
4387 PG_RETURN_NULL();
4388
4389 PG_RETURN_BOOL(RelationIsVisible(oid));
4390}
4391
4392Datum
4393pg_type_is_visible(PG_FUNCTION_ARGS)
4394{
4395 Oid oid = PG_GETARG_OID(0);
4396
4397 if (!SearchSysCacheExists1(TYPEOID, ObjectIdGetDatum(oid)))
4398 PG_RETURN_NULL();
4399
4400 PG_RETURN_BOOL(TypeIsVisible(oid));
4401}
4402
4403Datum
4404pg_function_is_visible(PG_FUNCTION_ARGS)
4405{
4406 Oid oid = PG_GETARG_OID(0);
4407
4408 if (!SearchSysCacheExists1(PROCOID, ObjectIdGetDatum(oid)))
4409 PG_RETURN_NULL();
4410
4411 PG_RETURN_BOOL(FunctionIsVisible(oid));
4412}
4413
4414Datum
4415pg_operator_is_visible(PG_FUNCTION_ARGS)
4416{
4417 Oid oid = PG_GETARG_OID(0);
4418
4419 if (!SearchSysCacheExists1(OPEROID, ObjectIdGetDatum(oid)))
4420 PG_RETURN_NULL();
4421
4422 PG_RETURN_BOOL(OperatorIsVisible(oid));
4423}
4424
4425Datum
4426pg_opclass_is_visible(PG_FUNCTION_ARGS)
4427{
4428 Oid oid = PG_GETARG_OID(0);
4429
4430 if (!SearchSysCacheExists1(CLAOID, ObjectIdGetDatum(oid)))
4431 PG_RETURN_NULL();
4432
4433 PG_RETURN_BOOL(OpclassIsVisible(oid));
4434}
4435
4436Datum
4437pg_opfamily_is_visible(PG_FUNCTION_ARGS)
4438{
4439 Oid oid = PG_GETARG_OID(0);
4440
4441 if (!SearchSysCacheExists1(OPFAMILYOID, ObjectIdGetDatum(oid)))
4442 PG_RETURN_NULL();
4443
4444 PG_RETURN_BOOL(OpfamilyIsVisible(oid));
4445}
4446
4447Datum
4448pg_collation_is_visible(PG_FUNCTION_ARGS)
4449{
4450 Oid oid = PG_GETARG_OID(0);
4451
4452 if (!SearchSysCacheExists1(COLLOID, ObjectIdGetDatum(oid)))
4453 PG_RETURN_NULL();
4454
4455 PG_RETURN_BOOL(CollationIsVisible(oid));
4456}
4457
4458Datum
4459pg_conversion_is_visible(PG_FUNCTION_ARGS)
4460{
4461 Oid oid = PG_GETARG_OID(0);
4462
4463 if (!SearchSysCacheExists1(CONVOID, ObjectIdGetDatum(oid)))
4464 PG_RETURN_NULL();
4465
4466 PG_RETURN_BOOL(ConversionIsVisible(oid));
4467}
4468
4469Datum
4470pg_statistics_obj_is_visible(PG_FUNCTION_ARGS)
4471{
4472 Oid oid = PG_GETARG_OID(0);
4473
4474 if (!SearchSysCacheExists1(STATEXTOID, ObjectIdGetDatum(oid)))
4475 PG_RETURN_NULL();
4476
4477 PG_RETURN_BOOL(StatisticsObjIsVisible(oid));
4478}
4479
4480Datum
4481pg_ts_parser_is_visible(PG_FUNCTION_ARGS)
4482{
4483 Oid oid = PG_GETARG_OID(0);
4484
4485 if (!SearchSysCacheExists1(TSPARSEROID, ObjectIdGetDatum(oid)))
4486 PG_RETURN_NULL();
4487
4488 PG_RETURN_BOOL(TSParserIsVisible(oid));
4489}
4490
4491Datum
4492pg_ts_dict_is_visible(PG_FUNCTION_ARGS)
4493{
4494 Oid oid = PG_GETARG_OID(0);
4495
4496 if (!SearchSysCacheExists1(TSDICTOID, ObjectIdGetDatum(oid)))
4497 PG_RETURN_NULL();
4498
4499 PG_RETURN_BOOL(TSDictionaryIsVisible(oid));
4500}
4501
4502Datum
4503pg_ts_template_is_visible(PG_FUNCTION_ARGS)
4504{
4505 Oid oid = PG_GETARG_OID(0);
4506
4507 if (!SearchSysCacheExists1(TSTEMPLATEOID, ObjectIdGetDatum(oid)))
4508 PG_RETURN_NULL();
4509
4510 PG_RETURN_BOOL(TSTemplateIsVisible(oid));
4511}
4512
4513Datum
4514pg_ts_config_is_visible(PG_FUNCTION_ARGS)
4515{
4516 Oid oid = PG_GETARG_OID(0);
4517
4518 if (!SearchSysCacheExists1(TSCONFIGOID, ObjectIdGetDatum(oid)))
4519 PG_RETURN_NULL();
4520
4521 PG_RETURN_BOOL(TSConfigIsVisible(oid));
4522}
4523
4524Datum
4525pg_my_temp_schema(PG_FUNCTION_ARGS)
4526{
4527 PG_RETURN_OID(myTempNamespace);
4528}
4529
4530Datum
4531pg_is_other_temp_schema(PG_FUNCTION_ARGS)
4532{
4533 Oid oid = PG_GETARG_OID(0);
4534
4535 PG_RETURN_BOOL(isOtherTempNamespace(oid));
4536}
4537