int batchSize = 100;
ExecutorAllCompletionService eacs = new ExecutorAllCompletionService(executor);
final TaskContext taskContext = new TaskContextImpl();
List<Map.Entry<byte[], byte[]>> entries = new ArrayList<Map.Entry<byte[], byte[]>>(batchSize);
DBIterator it = db.iterator(new ReadOptions().fillCache(false));
try {
for (it.seekToFirst(); it.hasNext();) {
Map.Entry<byte[], byte[]> entry = it.next();
entries.add(entry);
if (entries.size() == batchSize) {