Fix error during stats collection phase of query planning.
Fix a performance regression for some outer joins without equality predicates when
join_distribution_typeis set to
Improve performance for queries that have constant
VARCHARpredicates on join columns.
Add a variant of
strpos()that returns the position of the N-th instance of the substring.
strrpos()that returns the position of the N-th instance of a substring from the back of a string.
Add aggregation function
Add overload of
approx_set()which takes in the maximum standard error.
max_tasks_per_stagesession property and
stage.max-tasks-per-stageconfig property to limit the number of tasks per stage for grouped execution. Setting this session property allows queries running with grouped execution to use a predictable amount of memory independent of the cluster size.
Add encryption for spill files (see Spill to Disk).
Web UI Changes#
Add information about query warnings to the web UI.
Revert the change introduced in 0.219 to rebalance bucket assignment after restarting the cluster. Automatic rebalancing can cause unexpected downtime when restarting the cluster to resolve emergent issues.
Hive Connector Changes#
Improve coordinator memory utilization for Hive splits.
Improve performance of writing large ORC files.
ConnectorPageSinkProvider. It contains a boolean
partitionCommitRequired, which is false by default. See the note below about
commitPartitionfor more information.
ConnectorMetadata. This SPI is coupled with
pageSinkContext#partitionCommitRequiredand is used by the engine to commit a partition of data to the target connector. The connector that implements this SPI should ensure that if
pageSinkContext#isPartitionCommitRequiredis true in
ConnectorPageSinkProvider#createPageSink, the written data is not published until
ConnectorMetadata#commitPartitionis called. Also, it is expected for the connector to add
RowExpressionand prunes redundant part of it.
LogicalRowExpressionsto push negation down below conjunction or disjunction for a logical expression.
SplitSchedulingStrategyand a boolean
schedulerUsesHostAddressesthat indicates whether the network topology is used during scheduling. If false, the connector doesn’t need to provide the host addresses for remotely accessible splits.