Release 0.157
Reduce CPU usage of coordinator in large, heavily loaded clusters.
Add bitwise_and_agg() and aggregation functions.
Add config flag to set the minimum number of splits to consider for scheduling per batch.
Remove support for scheduling multiple tasks in the same stage on a single worker.
Hive Changes
Improve error message when trying to query tables that are bucketed on non-existent columns.
Add support for processing partitions whose schema does not match the table schema.
Add support for creating external Hive tables using the table property.