diff options
| -rw-r--r-- | src/backend/executor/nodeBitmapHeapscan.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index f0ac4e27d95..4b1d0e1ed01 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -743,6 +743,20 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) scanstate->pstate = NULL; /* + * Unfortunately it turns out that the below optimization does not + * take the removal of TIDs by a concurrent vacuum into + * account. The concurrent vacuum can remove dead TIDs and make + * pages ALL_VISIBLE while those dead TIDs are referenced in the + * bitmap. This would lead to a !need_tuples scan returning too + * many tuples. + * + * In the back-branches, we therefore simply disable the + * optimization. Removing all the relevant code would be too + * invasive (and a major backpatching pain). + */ + scanstate->can_skip_fetch = false; +#ifdef NOT_ANYMORE + /* * We can potentially skip fetching heap pages if we do not need any * columns of the table, either for checking non-indexable quals or for * returning data. This test is a bit simplistic, as it checks the @@ -751,6 +765,7 @@ ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags) */ scanstate->can_skip_fetch = (node->scan.plan.qual == NIL && node->scan.plan.targetlist == NIL); +#endif /* * Miscellaneous initialization |