use forward mode for gc scan
@@ -548,7 +548,7 @@ fn process_write_impl(cid: u64,
}
Command::Gc { ref ctx, safe_point, ref mut scan_key, ref keys } => {
let mut scan_key = scan_key.take();
- let mut txn = MvccTxn::new(snapshot, &mut statistics, 0, Some(ScanMode::Mixed));
+ let mut txn = MvccTxn::new(snapshot, &mut statistics, 0, Some(ScanMode::Forward));
for k in keys {
try!(txn.gc(k, safe_point));
if txn.write_size() >= MAX_TXN_WRITE_SIZE {
