This document discusses adding complex data to the Spark stack using Apache Drill. It provides an overview of Drill, how to integrate it with Spark, the current status and next steps. Drill allows SQL-based querying of structured, semi-structured and unstructured data across various data sources. It can be used as an input to Spark jobs and to query Spark RDDs. The integration provides benefits like flexibility, rich storage support and efficient distributed processing while combining Drill and Spark's capabilities.