diff options
Diffstat (limited to 'src/backend/executor/nodeBitmapHeapscan.c')
| -rw-r--r-- | src/backend/executor/nodeBitmapHeapscan.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index d2b27213ffe..bbb89e69962 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -4,16 +4,16 @@ * Routines to support bitmapped scans of relations * * NOTE: it is critical that this plan type only be used with MVCC-compliant - * snapshots (ie, regular snapshots, not SnapshotNow or one of the other + * snapshots (ie, regular snapshots, not SnapshotAny or one of the other * special snapshots). The reason is that since index and heap scans are * decoupled, there can be no assurance that the index tuple prompting a * visit to a particular heap TID still exists when the visit is made. * Therefore the tuple might not exist anymore either (which is OK because * heap_fetch will cope) --- but worse, the tuple slot could have been * re-used for a newer tuple. With an MVCC snapshot the newer tuple is - * certain to fail the time qual and so it will not be mistakenly returned. - * With SnapshotNow we might return a tuple that doesn't meet the required - * index qual conditions. + * certain to fail the time qual and so it will not be mistakenly returned, + * but with anything else we might return a tuple that doesn't meet the + * required index qual conditions. * * * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group |