3 ms·
You're right that the data is still stored in HDFS, and you can access the data that was originally accessed in Hive. However, because of the way Impala works,
by monstrado 14y ago
You're right that the data is still stored in HDFS, and you can access the data that was originally accessed in Hive. However, because of the way Impala works, it does in fact provide a real-time query interface for data that is sitting in Hadoop (HDFS). The back-end is written in C++ and accesses/processes data much differently than MapReduce which allows for some pretty awesome performance numbers :-)