presto-docs/src/main/sphinx/release/release-0.224.rst
ROW with subscript.Planning Time in Query Details page.hive.max-buckets-for-grouped-execution and session
property max_buckets_for_grouped_execution to limit the number of buckets
a query can access while still taking the advantage of grouped execution.
If more than the configured number of buckets are queried, the query will
run without grouped execution.hive.virtual_bucket_count to support grouped
execution for queries that read unbucketed tables and have no joins or
aggregations. This session property controls the number of virtual buckets
that the connector will create for unbucketed tables.