String className = new String(db.get(metaType + indexName + ":class"));
Class indexClass = Class.forName(className);
List<byte[]> keys = db.smembers(metaType + indexName + ":keys");
HashSet<String> indexKeys = new HashSet<String>();
if(null != keys){
for(byte[] key : keys){
indexKeys.add(new String(key));