Release 0.208
Warning
This release has the potential for data loss in the Hive connector when writing bucketed sorted tables.
General Changes
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_join
is enabled (#10724).Preserve field names when unnesting columns of type
ROW
.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
100
and can be changed with thequery.max-stage-count
configuration property and thequery_max_stage_count
session property.Add
spooky_hash_v2_32()
andspooky_hash_v2_64()
functions.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.
CLI Changes
Fix creation of the history file when it does not exist.
Add
PRESTO_HISTORY_FILE
environment 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
hive.collect-column-statistics-on-write
property.
Thrift Connector Changes
- Include error message from remote server in query failure message.