Apache Drill vs Apache Impala

Apache Drill
Schema-free SQL Query Engine for Hadoop, NoSQL and Cloud Storage. Get faster insights without the overhead (data loading, schema creation and maintenance, transformations, etc.). Analyze the multi-structured and nested data in non-relational datastores directly without transforming or restricting the data
Apache Impala
Apache Impala is a modern, open source, distributed SQL query engine for Apache Hadoop.