============= Release 0.170

General Changes

• Fix race condition that could cause queries to fail with InterruptedException in rare cases.
• Fix a performance regression for GROUP BY queries over UNION.
• Fix a performance regression that occurs when a significant number of exchange sources produce no data during an exchange (e.g., in a skewed hash join).

Web UI Changes

• Fix broken rendering when catalog properties are set.
• Fix rendering of live plan when query is queued.

JDBC Driver Changes

• Add support for DatabaseMetaData.getTypeInfo().

Hive Changes

• Improve decimal support for the Parquet reader.
• Remove misleading "HDFS" string from error messages.

Cassandra Changes

• Fix an intermittent connection issue for Cassandra 2.1.
• Remove support for selecting by partition key when the partition key is only partially specified. The cassandra.limit-for-partition-key-select and cassandra.fetch-size-for-partition-key-select config options are no longer supported.
• Remove partition key cache to improve consistency and reduce load on the Cassandra cluster due to background cache refresh.
• Reduce the number of connections opened to the Cassandra cluster. Now Presto opens a single connection from each node.
• Use exponential backoff for retries when Cassandra hosts are down. The retry timeout can be controlled via the cassandra.no-host-available-retry-timeout config option, which has a default value of 1m. The cassandra.no-host-available-retry-count config option is no longer supported.

Verifier Changes

• Add support for INSERT queries.