20.41. Release 0.208
This release has the potential for data loss in the Hive connector when writing bucketed sorted tables.
- Fix an issue with memory accounting that would lead to garbage collection pauses and out of memory exceptions.
- Fix an issue that produces incorrect results when
push_aggregation_through_joinis enabled (#10724).
- Preserve field names when unnesting columns of type
- Make the cluster out of memory killer more resilient to memory accounting leaks. Previously, memory accounting leaks on the workers could effectively disable the out of memory killer.
- Improve planning time for queries over tables with high column count.
- Add a limit on the number of stages in a query. The default is
100and can be changed with the
query.max-stage-countconfiguration property and the
- Add a cluster memory leak detector that logs queries that have possibly accounted for memory usage incorrectly on workers. This is a tool to for debugging internal errors.
- Add support for correlated subqueries requiring coercions.
- Add experimental support for running on Linux ppc64le.
- Fix creation of the history file when it does not exist.
PRESTO_HISTORY_FILEenvironment variable to override location of history file.
Hive Connector Changes
- Remove size limit for writing bucketed sorted tables.
- Support writer scaling for Parquet.
- Improve stripe size estimation for the optimized ORC writer. This reduces the number of cases where tiny ORC stripes will be written.
- Provide the actual size of CHAR, VARCHAR, and VARBINARY columns to the cost based optimizer.
- Collect column level statistics when writing tables. This is disabled by default,
and can be enabled by setting the
Thrift Connector Changes
- Include error message from remote server in query failure message.