diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/catalog/index.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 0f33de7b60d..41309bc2c4c 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -1394,6 +1394,13 @@ index_build(Relation heapRelation, HeapTuple indexTuple; Form_pg_index indexForm; + /* + * Broken HOT chains should not get reported in system catalogs; in + * particular it would be quite dangerous to try to modify the index's + * pg_index entry if we are reindexing pg_index itself. + */ + Assert(!IsSystemRelation(heapRelation)); + pg_index = heap_open(IndexRelationId, RowExclusiveLock); indexTuple = SearchSysCacheCopy(INDEXRELID, @@ -1453,7 +1460,13 @@ index_build(Relation heapRelation, * A side effect is to set indexInfo->ii_BrokenHotChain to true if we detect * any potentially broken HOT chains. Currently, we set this if there are * any RECENTLY_DEAD entries in a HOT chain, without trying very hard to - * detect whether they're really incompatible with the chain tip. + * detect whether they're really incompatible with the chain tip. However, + * we do not ever set ii_BrokenHotChain true when the relation is a system + * catalog. This is to avoid problematic behavior when reindexing pg_index + * itself: we can't safely change the index's indcheckxmin field when we're + * partway through such an operation. It should be okay since the set of + * indexes on a system catalog ought not change during concurrent operations, + * so that no HOT chain in it could ever become broken. */ double IndexBuildHeapScan(Relation heapRelation, @@ -1463,6 +1476,7 @@ IndexBuildHeapScan(Relation heapRelation, IndexBuildCallback callback, void *callback_state) { + bool is_system_catalog; HeapScanDesc scan; HeapTuple heapTuple; Datum values[INDEX_MAX_KEYS]; @@ -1482,6 +1496,9 @@ IndexBuildHeapScan(Relation heapRelation, */ Assert(OidIsValid(indexRelation->rd_rel->relam)); + /* Remember if it's a system catalog */ + is_system_catalog = IsSystemRelation(heapRelation); + /* * Need an EState for evaluation of index expressions and partial-index * predicates. Also a slot to hold the current tuple. @@ -1620,7 +1637,8 @@ IndexBuildHeapScan(Relation heapRelation, { indexIt = false; /* mark the index as unsafe for old snapshots */ - indexInfo->ii_BrokenHotChain = true; + if (!is_system_catalog) + indexInfo->ii_BrokenHotChain = true; } else if (indexInfo->ii_BrokenHotChain) indexIt = false; @@ -1709,7 +1727,8 @@ IndexBuildHeapScan(Relation heapRelation, { indexIt = false; /* mark the index as unsafe for old snapshots */ - indexInfo->ii_BrokenHotChain = true; + if (!is_system_catalog) + indexInfo->ii_BrokenHotChain = true; } else if (indexInfo->ii_BrokenHotChain) indexIt = false; |