3131#include "catalog/pg_authid.h"
3232#include "catalog/pg_database.h"
3333#include "catalog/pg_db_role_setting.h"
34+ #include "catalog/pg_largeobject.h"
3435#include "catalog/pg_namespace.h"
3536#include "catalog/pg_replication_origin.h"
3637#include "catalog/pg_shdepend.h"
120121IsCatalogRelationOid (Oid relid )
121122{
122123 /*
123- * We consider a relation to be a system catalog if it has an OID that was
124- * manually assigned or assigned by genbki.pl. This includes all the
125- * defined catalogs, their indexes, and their TOAST tables and indexes.
124+ * We consider a relation to be a system catalog if it has a pinned OID.
125+ * This includes all the defined catalogs, their indexes, and their TOAST
126+ * tables and indexes.
126127 *
127128 * This rule excludes the relations in information_schema, which are not
128129 * integral to the system and can be treated the same as user relations.
@@ -132,7 +133,7 @@ IsCatalogRelationOid(Oid relid)
132133 * This test is reliable since an OID wraparound will skip this range of
133134 * OIDs; see GetNewObjectId().
134135 */
135- return (relid < (Oid ) FirstBootstrapObjectId );
136+ return (relid < (Oid ) FirstUnpinnedObjectId );
136137}
137138
138139/*
@@ -294,6 +295,64 @@ IsSharedRelation(Oid relationId)
294295 return false;
295296}
296297
298+ /*
299+ * IsPinnedObject
300+ * Given the class + OID identity of a database object, report whether
301+ * it is "pinned", that is not droppable because the system requires it.
302+ *
303+ * We used to represent this explicitly in pg_depend, but that proved to be
304+ * an undesirable amount of overhead, so now we rely on an OID range test.
305+ */
306+ bool
307+ IsPinnedObject (Oid classId , Oid objectId )
308+ {
309+ /*
310+ * Objects with OIDs above FirstUnpinnedObjectId are never pinned. Since
311+ * the OID generator skips this range when wrapping around, this check
312+ * guarantees that user-defined objects are never considered pinned.
313+ */
314+ if (objectId >= FirstUnpinnedObjectId )
315+ return false;
316+
317+ /*
318+ * Large objects are never pinned. We need this special case because
319+ * their OIDs can be user-assigned.
320+ */
321+ if (classId == LargeObjectRelationId )
322+ return false;
323+
324+ /*
325+ * There are a few objects defined in the catalog .dat files that, as a
326+ * matter of policy, we prefer not to treat as pinned. We used to handle
327+ * that by excluding them from pg_depend, but it's just as easy to
328+ * hard-wire their OIDs here. (If the user does indeed drop and recreate
329+ * them, they'll have new but certainly-unpinned OIDs, so no problem.)
330+ *
331+ * Checking both classId and objectId is overkill, since OIDs below
332+ * FirstGenbkiObjectId should be globally unique, but do it anyway for
333+ * robustness.
334+ */
335+
336+ /* template1 is not pinned */
337+ if (classId == DatabaseRelationId &&
338+ objectId == TemplateDbOid )
339+ return false;
340+
341+ /* the public namespace is not pinned */
342+ if (classId == NamespaceRelationId &&
343+ objectId == PG_PUBLIC_NAMESPACE )
344+ return false;
345+
346+ /*
347+ * All other initdb-created objects are pinned. This is overkill (the
348+ * system doesn't really depend on having every last weird datatype, for
349+ * instance) but generating only the minimum required set of dependencies
350+ * seems hard, and enforcing an accurate list would be much more expensive
351+ * than the simple range test used here.
352+ */
353+ return true;
354+ }
355+
297356
298357/*
299358 * GetNewOidWithIndex
@@ -533,7 +592,8 @@ pg_nextoid(PG_FUNCTION_ARGS)
533592 if (!superuser ())
534593 ereport (ERROR ,
535594 (errcode (ERRCODE_INSUFFICIENT_PRIVILEGE ),
536- errmsg ("must be superuser to call pg_nextoid()" )));
595+ errmsg ("must be superuser to call %s()" ,
596+ "pg_nextoid" )));
537597
538598 rel = table_open (reloid , RowExclusiveLock );
539599 idx = index_open (idxoid , RowExclusiveLock );
@@ -580,5 +640,29 @@ pg_nextoid(PG_FUNCTION_ARGS)
580640 table_close (rel , RowExclusiveLock );
581641 index_close (idx , RowExclusiveLock );
582642
583- return newoid ;
643+ PG_RETURN_OID (newoid );
644+ }
645+
646+ /*
647+ * SQL callable interface for StopGeneratingPinnedObjectIds().
648+ *
649+ * This is only to be used by initdb, so it's intentionally not documented in
650+ * the user facing docs.
651+ */
652+ Datum
653+ pg_stop_making_pinned_objects (PG_FUNCTION_ARGS )
654+ {
655+ /*
656+ * Belt-and-suspenders check, since StopGeneratingPinnedObjectIds will
657+ * fail anyway in non-single-user mode.
658+ */
659+ if (!superuser ())
660+ ereport (ERROR ,
661+ (errcode (ERRCODE_INSUFFICIENT_PRIVILEGE ),
662+ errmsg ("must be superuser to call %s()" ,
663+ "pg_stop_making_pinned_objects" )));
664+
665+ StopGeneratingPinnedObjectIds ();
666+
667+ PG_RETURN_VOID ();
584668}
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