diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 26 |
1 files changed, 9 insertions, 17 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index ec9853603fd..d8d4f3b1f5a 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -1654,8 +1654,8 @@ heap_hot_search_buffer(ItemPointer tid, Relation relation, Buffer buffer, /* * heap_get_latest_tid - get the latest tid of a specified tuple * - * Actually, this gets the latest version that is visible according to - * the passed snapshot. You can pass SnapshotDirty to get the very latest, + * Actually, this gets the latest version that is visible according to the + * scan's snapshot. Create a scan using SnapshotDirty to get the very latest, * possibly uncommitted version. * * *tid is both an input and an output parameter: it is updated to @@ -1663,28 +1663,20 @@ heap_hot_search_buffer(ItemPointer tid, Relation relation, Buffer buffer, * if no version of the row passes the snapshot test. */ void -heap_get_latest_tid(Relation relation, - Snapshot snapshot, +heap_get_latest_tid(TableScanDesc sscan, ItemPointer tid) { - BlockNumber blk; + Relation relation = sscan->rs_rd; + Snapshot snapshot = sscan->rs_snapshot; ItemPointerData ctid; TransactionId priorXmax; - /* this is to avoid Assert failures on bad input */ - if (!ItemPointerIsValid(tid)) - return; - /* - * Since this can be called with user-supplied TID, don't trust the input - * too much. (RelationGetNumberOfBlocks is an expensive check, so we - * don't check t_ctid links again this way. Note that it would not do to - * call it just once and save the result, either.) + * table_get_latest_tid verified that the passed in tid is valid. Assume + * that t_ctid links are valid however - there shouldn't be invalid ones + * in the table. */ - blk = ItemPointerGetBlockNumber(tid); - if (blk >= RelationGetNumberOfBlocks(relation)) - elog(ERROR, "block number %u is out of range for relation \"%s\"", - blk, RelationGetRelationName(relation)); + Assert(ItemPointerIsValid(tid)); /* * Loop to chase down t_ctid links. At top of loop, ctid is the tuple we |