diff --git a/core/src/kvs/rocksdb/mod.rs b/core/src/kvs/rocksdb/mod.rs
index f7847f3e..d7bc9a8b 100644
--- a/core/src/kvs/rocksdb/mod.rs
+++ b/core/src/kvs/rocksdb/mod.rs
@@ -404,23 +404,21 @@ impl super::api::Transaction for Transaction {
 		// Set the ReadOptions with the snapshot
 		let mut ro = ReadOptions::default();
 		ro.set_snapshot(&inner.snapshot());
+		ro.set_async_io(true);
+		ro.fill_cache(true);
 		// Create the iterator
 		let mut iter = inner.raw_iterator_opt(ro);
 		// Seek to the start key
 		iter.seek(&rng.start);
-		// Scan the keys in the iterator
-		while iter.valid() {
-			// Check the scan limit
-			if res.len() < limit as usize {
-				// Get the key and value
-				let k = iter.key();
-				// Check the key and value
-				if let Some(k) = k {
-					if k >= beg && k < end {
-						res.push(k.to_vec());
-						iter.next();
-						continue;
-					}
+		// Check the scan limit
+		while res.len() < limit as usize {
+			// Check the key and value
+			if let Some(k) = iter.key() {
+				// Check the range validity
+				if k >= beg && k < end {
+					res.push(k.to_vec());
+					iter.next();
+					continue;
 				}
 			}
 			// Exit
@@ -455,23 +453,21 @@ impl super::api::Transaction for Transaction {
 		// Set the ReadOptions with the snapshot
 		let mut ro = ReadOptions::default();
 		ro.set_snapshot(&inner.snapshot());
+		ro.set_async_io(true);
+		ro.fill_cache(true);
 		// Create the iterator
 		let mut iter = inner.raw_iterator_opt(ro);
 		// Seek to the start key
 		iter.seek(&rng.start);
-		// Scan the keys in the iterator
-		while iter.valid() {
-			// Check the scan limit
-			if res.len() < limit as usize {
-				// Get the key and value
-				let (k, v) = (iter.key(), iter.value());
-				// Check the key and value
-				if let (Some(k), Some(v)) = (k, v) {
-					if k >= beg && k < end {
-						res.push((k.to_vec(), v.to_vec()));
-						iter.next();
-						continue;
-					}
+		// Check the scan limit
+		while res.len() < limit as usize {
+			// Check the key and value
+			if let Some((k, v)) = iter.item() {
+				// Check the range validity
+				if k >= beg && k < end {
+					res.push((k.to_vec(), v.to_vec()));
+					iter.next();
+					continue;
 				}
 			}
 			// Exit