============= Release 0.168

General Changes

• Fix correctness issues for certain JOIN queries that require implicit coercions for terms in the join criteria.
• Fix invalid "No more locations already set" error.
• Fix invalid "No more buffers already set" error.
• Temporarily revert empty join short-circuit optimization due to issue with hanging queries.
• Improve performance of DECIMAL type and operators.
• Optimize window frame computation for empty frames.
• :func:!json_extract and :func:!json_extract_scalar now support escaping double quotes or backslashes using a backslash with a JSON path subscript. This changes the semantics of any invocation using a backslash, as backslashes were previously treated as normal characters.
• Improve performance of :func:!filter and :func:!map_filter lambda functions.
• Add :doc:/connector/memory.
• Add :func:!arrays_overlap and :func:!array_except functions.
• Allow concatenating more than two arrays with concat() or maps with :func:!map_concat.
• Add a time limit for the iterative optimizer. It can be adjusted via the iterative_optimizer_timeout session property or experimental.iterative-optimizer-timeout configuration option.
• ROW types are now orderable if all of the field types are orderable. This allows using them in comparison expressions, ORDER BY and functions that require orderable types (e.g., :func:!max).

JDBC Driver Changes

• Update DatabaseMetaData to reflect features that are now supported.
• Update advertised JDBC version to 4.2, which part of Java 8.
• Return correct driver and server versions rather than 1.0.

Hive Changes

• Fix reading decimals for RCFile text format using non-optimized reader.
• Fix bug which prevented the file based metastore from being used.
• Enable optimized RCFile reader by default.
• Common user errors are now correctly categorized.
• Add new, experimental, RCFile writer optimized for Presto. The new writer can be enabled with the rcfile_optimized_writer_enabled session property or the hive.rcfile-optimized-writer.enabled Hive catalog property.

Cassandra Changes

• Add predicate pushdown for clustering key.

MongoDB Changes

• Allow SSL connections using the mongodb.ssl.enabled config flag.

SPI Changes

• ConnectorIndex now returns ConnectorPageSource instead of RecordSet. Existing connectors that support index join can use the RecordPageSource to adapt to the new API.