# Presto 316 Documentation

## 12.63. 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.