Integrate Apache Flink with Apache Hive to provide: 1. Unified catalog APIs for Flink's metadata storage and management. This includes in-memory and persistent catalog implementations. 2. Deep integration with Hive by implementing a Hive catalog and connectors for reading and writing Hive metadata and data. 3. Support for a complete set of SQL DDL/DML statements in Flink. This work will provide a seamless experience for both batch and streaming SQL queries across Flink and Hive, enabling users to benefit from Flink's processing capabilities directly through Hive. An initial release is targeted for June 2019 in Flink 1.9.0.