diff options
Diffstat (limited to 'src/backend/utils/cache')
| -rw-r--r-- | src/backend/utils/cache/relcache.c | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c index d47d2d37fcb..2810b35eea1 100644 --- a/src/backend/utils/cache/relcache.c +++ b/src/backend/utils/cache/relcache.c @@ -1601,6 +1601,7 @@ RelationIdGetRelation(Oid relationId) RelationReloadIndexInfo(rd); else RelationClearRelation(rd, true); + Assert(rd->rd_isvalid); } return rd; } @@ -1712,8 +1713,9 @@ RelationReloadIndexInfo(Relation relation) /* Should be called only for invalidated indexes */ Assert(relation->rd_rel->relkind == RELKIND_INDEX && !relation->rd_isvalid); - /* Should be closed at smgr level */ - Assert(relation->rd_smgr == NULL); + + /* Ensure it's closed at smgr level */ + RelationCloseSmgr(relation); /* Must free any AM cached data upon relcache flush */ if (relation->rd_amcache) @@ -1892,12 +1894,11 @@ RelationClearRelation(Relation relation, bool rebuild) * be unable to recover. However, we must redo RelationInitPhysicalAddr * in case it is a mapped relation whose mapping changed. * - * If it's a nailed index, then we need to re-read the pg_class row to see - * if its relfilenode changed. We can't necessarily do that here, because - * we might be in a failed transaction. We assume it's okay to do it if - * there are open references to the relcache entry (cf notes for - * AtEOXact_RelationCache). Otherwise just mark the entry as possibly - * invalid, and it'll be fixed when next opened. + * If it's a nailed-but-not-mapped index, then we need to re-read the + * pg_class row to see if its relfilenode changed. We do that immediately + * if we're inside a valid transaction and the relation is open (not + * counting the nailed refcount). Otherwise just mark the entry as + * possibly invalid, and it'll be fixed when next opened. */ if (relation->rd_isnailed) { @@ -1906,7 +1907,7 @@ RelationClearRelation(Relation relation, bool rebuild) if (relation->rd_rel->relkind == RELKIND_INDEX) { relation->rd_isvalid = false; /* needs to be revalidated */ - if (relation->rd_refcnt > 1) + if (relation->rd_refcnt > 1 && IsTransactionState()) RelationReloadIndexInfo(relation); } return; @@ -1924,7 +1925,8 @@ RelationClearRelation(Relation relation, bool rebuild) relation->rd_indexcxt != NULL) { relation->rd_isvalid = false; /* needs to be revalidated */ - RelationReloadIndexInfo(relation); + if (IsTransactionState()) + RelationReloadIndexInfo(relation); return; } @@ -1945,6 +1947,29 @@ RelationClearRelation(Relation relation, bool rebuild) /* And release storage */ RelationDestroyRelation(relation); } + else if (!IsTransactionState()) + { + /* + * If we're not inside a valid transaction, we can't do any catalog + * access so it's not possible to rebuild yet. Just exit, leaving + * rd_isvalid = false so that the rebuild will occur when the entry is + * next opened. + * + * Note: it's possible that we come here during subtransaction abort, + * and the reason for wanting to rebuild is that the rel is open in + * the outer transaction. In that case it might seem unsafe to not + * rebuild immediately, since whatever code has the rel already open + * will keep on using the relcache entry as-is. However, in such a + * case the outer transaction should be holding a lock that's + * sufficient to prevent any significant change in the rel's schema, + * so the existing entry contents should be good enough for its + * purposes; at worst we might be behind on statistics updates or the + * like. (See also CheckTableNotInUse() and its callers.) These same + * remarks also apply to the cases above where we exit without having + * done RelationReloadIndexInfo() yet. + */ + return; + } else { /* @@ -2057,6 +2082,7 @@ RelationClearRelation(Relation relation, bool rebuild) * RelationFlushRelation * * Rebuild the relation if it is open (refcount > 0), else blow it away. + * This is used when we receive a cache invalidation event for the rel. */ static void RelationFlushRelation(Relation relation) |