diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtree.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtree.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c index cd2d4a6c54e..fc31fe4ad9f 100644 --- a/src/backend/access/nbtree/nbtree.c +++ b/src/backend/access/nbtree/nbtree.c @@ -804,6 +804,10 @@ btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats, } /* + * Check to see if we need to issue one final WAL record for this index, + * which may be needed for correctness on a hot standby node when non-MVCC + * index scans could take place. + * * If the WAL is replayed in hot standby, the replay process needs to get * cleanup locks on all index leaf pages, just as we've been doing here. * However, we won't issue any WAL records about pages that have no items @@ -1013,10 +1017,13 @@ restart: if (ndeletable > 0) { /* - * Notice that the issued XLOG_BTREE_VACUUM WAL record includes an - * instruction to the replay code to get cleanup lock on all pages - * between the previous lastBlockVacuumed and this page. This - * ensures that WAL replay locks all leaf pages at some point. + * Notice that the issued XLOG_BTREE_VACUUM WAL record includes + * all information to the replay code to allow it to get a cleanup + * lock on all pages between the previous lastBlockVacuumed and + * this page. This ensures that WAL replay locks all leaf pages at + * some point, which is important should non-MVCC scans be + * requested. This is currently unused on standby, but we record + * it anyway, so that the WAL contains the required information. * * Since we can visit leaf pages out-of-order when recursing, * replay might end up locking such pages an extra time, but it |