============= Release 0.158

General Changes

Fix regression that could cause high CPU and heap usage on coordinator when processing certain types of long running queries.
Fix incorrect pruning of output columns in EXPLAIN ANALYZE.
Fix ordering of CHAR values so that trailing spaces are ordered after control characters.
Fix query failures for connectors that produce non-remotely accessible splits.
Fix non-linear performance issue when parsing certain SQL expressions.
Fix case-sensitivity issues when operating on columns of ROW data type.
Fix failure when creating views for tables names that need quoting.
Return NULL from :func:!element_at for out-of-range indices instead of failing.
Remove redundancies in query plans, which can reduce data transfers over the network and reduce CPU requirements.
Validate resource groups configuration file on startup to ensure that all selectors reference a configured resource group.
Add experimental on-disk merge sort for aggregations. This can be enabled with the experimental.spill-enabled configuration flag.
Push down predicates for DECIMAL, TINYINT, SMALLINT and REAL data types.

Add hidden $bucket column for bucketed tables that contains the bucket number for the current row.
Prevent inserting into non-managed (i.e., external) tables.
Add configurable size limit to Hive metastore cache to avoid using too much coordinator memory.