============= Release 0.167

General Changes

• Fix planning failure when a window function depends on the output of another window function.
• Fix planning failure for certain aggregation with both DISTINCT and GROUP BY.
• Fix incorrect aggregation of operator summary statistics.
• Fix a join issue that could cause joins that produce and filter many rows to monopolize worker threads, even after the query has finished.
• Expand plan predicate pushdown capabilities involving implicitly coerced types.
• Short-circuit inner and right join when right side is empty.
• Optimize constant patterns for LIKE predicates that use an escape character.
• Validate escape sequences in LIKE predicates per the SQL standard.
• Reduce memory usage of :func:!min_by and :func:!max_by.
• Add :func:!transform_keys, :func:!transform_values and :func:!zip_with lambda functions.
• Add :func:!levenshtein_distance function.
• Add JMX stat for the elapsed time of the longest currently active split.
• Add JMX stats for compiler caches.
• Raise required Java version to 8u92.

Security Changes

• The http.server.authentication.enabled config option that previously enabled Kerberos has been replaced with http-server.authentication.type=KERBEROS.
• Add support for :doc:/security/ldap using username and password.
• Add a read-only :doc:/develop/system-access-control named read-only.
• Allow access controls to filter the results of listing catalogs, schemas and tables.
• Add access control checks for :doc:/sql/show-schemas and :doc:/sql/show-tables.

Web UI Changes

• Add operator-level performance analysis.
• Improve visibility of blocked and reserved query states.
• Lots of minor improvements.

JDBC Driver Changes

• Allow escaping in DatabaseMetaData patterns.

Hive Changes

• Fix write operations for ViewFileSystem by using a relative location.
• Remove support for the hive-cdh4 and hive-hadoop1 connectors which support CDH 4 and Hadoop 1.x, respectively.
• Remove the hive-cdh5 connector as an alias for hive-hadoop2.
• Remove support for the legacy S3 block-based file system.
• Add support for KMS-managed keys for S3 server-side encryption.

Cassandra Changes

• Add support for Cassandra 3.x by removing the deprecated Thrift interface used to connect to Cassandra. The following config options are now defunct and must be removed: cassandra.thrift-port, cassandra.thrift-connection-factory-class, cassandra.transport-factory-options and cassandra.partitioner.

SPI Changes

• Add methods to SystemAccessControl and ConnectorAccessControl to filter the list of catalogs, schemas and tables.
• Add access control checks for :doc:/sql/show-schemas and :doc:/sql/show-tables.
• Add beginQuery and cleanupQuery notifications to ConnectorMetadata.