diff options
| -rw-r--r-- | src/backend/bootstrap/bootstrap.c | 2 | ||||
| -rw-r--r-- | src/backend/catalog/heap.c | 2 | ||||
| -rw-r--r-- | src/backend/catalog/index.c | 38 | ||||
| -rw-r--r-- | src/backend/commands/cluster.c | 6 | ||||
| -rw-r--r-- | src/backend/commands/indexcmds.c | 2 | ||||
| -rw-r--r-- | src/include/catalog/index.h | 3 |
6 files changed, 42 insertions, 11 deletions
diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c index 5a0f852b6fe..faf5582edfc 100644 --- a/src/backend/bootstrap/bootstrap.c +++ b/src/backend/bootstrap/bootstrap.c @@ -1286,7 +1286,7 @@ build_indices(void) heap = heap_open(ILHead->il_heap, NoLock); ind = index_open(ILHead->il_ind, NoLock); - index_build(heap, ind, ILHead->il_info, false); + index_build(heap, ind, ILHead->il_info, false, false); index_close(ind, NoLock); heap_close(heap, NoLock); diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c index 071266536df..70a32011f42 100644 --- a/src/backend/catalog/heap.c +++ b/src/backend/catalog/heap.c @@ -2344,7 +2344,7 @@ RelationTruncateIndexes(Relation heapRelation) /* Initialize the index and rebuild */ /* Note: we do not need to re-establish pkey setting */ - index_build(heapRelation, currentIndex, indexInfo, false); + index_build(heapRelation, currentIndex, indexInfo, false, true); /* We're done with this index */ index_close(currentIndex, NoLock); diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 487dbbf24d2..a074150b630 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -866,7 +866,7 @@ index_create(Oid heapRelationId, } else { - index_build(heapRelation, indexRelation, indexInfo, isprimary); + index_build(heapRelation, indexRelation, indexInfo, isprimary, false); } /* @@ -1357,8 +1357,11 @@ setNewRelfilenode(Relation relation, TransactionId freezeXid) * entries of the index and heap relation as needed, using statistics * returned by ambuild as well as data passed by the caller. * - * Note: when reindexing an existing index, isprimary can be false; - * the index is already properly marked and need not be re-marked. + * isprimary tells whether to mark the index as a primary-key index. + * isreindex indicates we are recreating a previously-existing index. + * + * Note: when reindexing an existing index, isprimary can be false even if + * the index is a PK; it's already properly marked and need not be re-marked. * * Note: before Postgres 8.2, the passed-in heap and index Relations * were automatically closed by this routine. This is no longer the case. @@ -1368,7 +1371,8 @@ void index_build(Relation heapRelation, Relation indexRelation, IndexInfo *indexInfo, - bool isprimary) + bool isprimary, + bool isreindex) { RegProcedure procedure; IndexBuildResult *stats; @@ -1415,8 +1419,15 @@ index_build(Relation heapRelation, * If we found any potentially broken HOT chains, mark the index as not * being usable until the current transaction is below the event horizon. * See src/backend/access/heap/README.HOT for discussion. - */ - if (indexInfo->ii_BrokenHotChain) + * + * However, when reindexing an existing index, we should do nothing here. + * Any HOT chains that are broken with respect to the index must predate + * the index's original creation, so there is no need to change the + * index's usability horizon. Moreover, we *must not* try to change + * the index's pg_index entry while reindexing pg_index itself, and this + * optimization nicely prevents that. + */ + if (indexInfo->ii_BrokenHotChain && !isreindex) { Oid indexId = RelationGetRelid(indexRelation); Relation pg_index; @@ -1432,6 +1443,9 @@ index_build(Relation heapRelation, elog(ERROR, "cache lookup failed for index %u", indexId); indexForm = (Form_pg_index) GETSTRUCT(indexTuple); + /* If it's a new index, indcheckxmin shouldn't be set ... */ + Assert(!indexForm->indcheckxmin); + indexForm->indcheckxmin = true; simple_heap_update(pg_index, &indexTuple->t_self, indexTuple); CatalogUpdateIndexes(pg_index, indexTuple); @@ -2333,7 +2347,7 @@ reindex_index(Oid indexId) /* Initialize the index and rebuild */ /* Note: we do not need to re-establish pkey setting */ - index_build(heapRelation, iRel, indexInfo, false); + index_build(heapRelation, iRel, indexInfo, false, true); } PG_CATCH(); { @@ -2352,6 +2366,16 @@ reindex_index(Oid indexId) * We can also reset indcheckxmin, because we have now done a * non-concurrent index build, *except* in the case where index_build * found some still-broken HOT chains. + * + * Note that it is important to not update the pg_index entry if we don't + * have to, because updating it will move the index's usability horizon + * (recorded as the tuple's xmin value) if indcheckxmin is true. We don't + * really want REINDEX to move the usability horizon forward ever, but we + * have no choice if we are to fix indisvalid or indisready. Of course, + * clearing indcheckxmin eliminates the issue, so we're happy to do that + * if we can. Another reason for caution here is that while reindexing + * pg_index itself, we must not try to update it. We assume that + * pg_index's indexes will always have these flags in their clean state. */ pg_index = heap_open(IndexRelationId, RowExclusiveLock); diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index 816cf47bb3d..f6dc6e2c017 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -626,6 +626,12 @@ rebuild_relation(Relation OldHeap, Oid indexOid) * Rebuild each index on the relation (but not the toast table, which is * all-new at this point). We do not need CommandCounterIncrement() * because reindex_relation does it. + * + * Note: because index_build is called via reindex_relation, it will never + * set indcheckxmin true for the indexes. This is OK even though in some + * sense we are building new indexes rather than rebuilding existing ones, + * because the new heap won't contain any HOT chains at all, let alone + * broken ones, so it can't be necessary to set indcheckxmin. */ reindex_relation(tableOid, false); diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c index 77d6e53f70b..6ba5b5d36b8 100644 --- a/src/backend/commands/indexcmds.c +++ b/src/backend/commands/indexcmds.c @@ -554,7 +554,7 @@ DefineIndex(RangeVar *heapRelation, indexInfo->ii_BrokenHotChain = false; /* Now build the index */ - index_build(rel, indexRelation, indexInfo, primary); + index_build(rel, indexRelation, indexInfo, primary, false); /* Close both the relations, but keep the locks */ heap_close(rel, NoLock); diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h index 18064889aa1..5eca12b2ef5 100644 --- a/src/include/catalog/index.h +++ b/src/include/catalog/index.h @@ -58,7 +58,8 @@ extern void setNewRelfilenode(Relation relation, TransactionId freezeXid); extern void index_build(Relation heapRelation, Relation indexRelation, IndexInfo *indexInfo, - bool isprimary); + bool isprimary, + bool isreindex); extern double IndexBuildHeapScan(Relation heapRelation, Relation indexRelation, |