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Solve the problem of OID collisions by probing for duplicate OIDs

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whenever we generate a new OID.  This prevents occasional duplicate-OID
errors that can otherwise occur once the OID counter has wrapped around.
Duplicate relfilenode values are also checked for when creating new
physical files.  Per my recent proposal.
This commit is contained in:
Tom Lane
2005-08-12 01:36:05 +00:00
parent 9e4a2de844
commit 721e53785d
20 changed files with 416 additions and 268 deletions
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57
src/backend/utils/cache/relcache.c vendored
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/cache/relcache.c,v 1.226 2005/08/08 19:17:22 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/cache/relcache.c,v 1.227 2005/08/12 01:35:59 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1899,6 +1899,7 @@ AtEOXact_RelationCache(bool isCommit)
{
list_free(relation->rd_indexlist);
relation->rd_indexlist = NIL;
relation->rd_oidindex = InvalidOid;
relation->rd_indexvalid = 0;
}
}
@ -1959,6 +1960,7 @@ AtEOSubXact_RelationCache(bool isCommit, SubTransactionId mySubid,
{
list_free(relation->rd_indexlist);
relation->rd_indexlist = NIL;
relation->rd_oidindex = InvalidOid;
relation->rd_indexvalid = 0;
}
}
@ -2512,6 +2514,11 @@ CheckConstraintFetch(Relation relation)
* may freeList() the returned list after scanning it. This is necessary
* since the caller will typically be doing syscache lookups on the relevant
* indexes, and syscache lookup could cause SI messages to be processed!
*
* We also update rd_oidindex, which this module treats as effectively part
* of the index list. rd_oidindex is valid when rd_indexvalid isn't zero;
* it is the pg_class OID of a unique index on OID when the relation has one,
* and InvalidOid if there is no such index.
*/
List *
RelationGetIndexList(Relation relation)
@ -2521,6 +2528,7 @@ RelationGetIndexList(Relation relation)
ScanKeyData skey;
HeapTuple htup;
List *result;
Oid oidIndex;
MemoryContext oldcxt;
/* Quick exit if we already computed the list. */
@ -2534,6 +2542,7 @@ RelationGetIndexList(Relation relation)
* memory leakage if we get some sort of error partway through.
*/
result = NIL;
oidIndex = InvalidOid;
/* Prepare to scan pg_index for entries having indrelid = this rel. */
ScanKeyInit(&skey,
@ -2549,7 +2558,16 @@ RelationGetIndexList(Relation relation)
{
Form_pg_index index = (Form_pg_index) GETSTRUCT(htup);
/* Add index's OID to result list in the proper order */
result = insert_ordered_oid(result, index->indexrelid);
/* Check to see if it is a unique, non-partial btree index on OID */
if (index->indnatts == 1 &&
index->indisunique &&
index->indkey.values[0] == ObjectIdAttributeNumber &&
index->indclass.values[0] == OID_BTREE_OPS_OID &&
heap_attisnull(htup, Anum_pg_index_indpred))
oidIndex = index->indexrelid;
}
systable_endscan(indscan);
@ -2558,6 +2576,7 @@ RelationGetIndexList(Relation relation)
/* Now save a copy of the completed list in the relcache entry. */
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
relation->rd_indexlist = list_copy(result);
relation->rd_oidindex = oidIndex;
relation->rd_indexvalid = 1;
MemoryContextSwitchTo(oldcxt);
@ -2601,8 +2620,8 @@ insert_ordered_oid(List *list, Oid datum)
* RelationSetIndexList -- externally force the index list contents
*
* This is used to temporarily override what we think the set of valid
* indexes is. The forcing will be valid only until transaction commit
* or abort.
* indexes is (including the presence or absence of an OID index).
* The forcing will be valid only until transaction commit or abort.
*
* This should only be applied to nailed relations, because in a non-nailed
* relation the hacked index list could be lost at any time due to SI
@ -2611,7 +2630,7 @@ insert_ordered_oid(List *list, Oid datum)
* It is up to the caller to make sure the given list is correctly ordered.
*/
void
RelationSetIndexList(Relation relation, List *indexIds)
RelationSetIndexList(Relation relation, List *indexIds, Oid oidIndex)
{
MemoryContext oldcxt;
@ -2623,11 +2642,40 @@ RelationSetIndexList(Relation relation, List *indexIds)
/* Okay to replace old list */
list_free(relation->rd_indexlist);
relation->rd_indexlist = indexIds;
relation->rd_oidindex = oidIndex;
relation->rd_indexvalid = 2; /* mark list as forced */
/* must flag that we have a forced index list */
need_eoxact_work = true;
}
/*
* RelationGetOidIndex -- get the pg_class OID of the relation's OID index
*
* Returns InvalidOid if there is no such index.
*/
Oid
RelationGetOidIndex(Relation relation)
{
List *ilist;
/*
* If relation doesn't have OIDs at all, caller is probably confused.
* (We could just silently return InvalidOid, but it seems better to
* throw an assertion.)
*/
Assert(relation->rd_rel->relhasoids);
if (relation->rd_indexvalid == 0)
{
/* RelationGetIndexList does the heavy lifting. */
ilist = RelationGetIndexList(relation);
list_free(ilist);
Assert(relation->rd_indexvalid != 0);
}
return relation->rd_oidindex;
}
/*
* RelationGetIndexExpressions -- get the index expressions for an index
*
@ -3057,6 +3105,7 @@ load_relcache_init_file(void)
rel->rd_refcnt = 0;
rel->rd_indexvalid = 0;
rel->rd_indexlist = NIL;
rel->rd_oidindex = InvalidOid;
rel->rd_createSubid = InvalidSubTransactionId;
MemSet(&rel->pgstat_info, 0, sizeof(rel->pgstat_info));