Release 0.181#
General#
Fix query failure and memory usage tracking when query contains
transform_keys()
ortransform_values()
.Prevent
CREATE TABLE IF NOT EXISTS
queries from ever failing with “Table already exists”.Fix query failure when
ORDER BY
expressions reference columns that are used in theGROUP BY
clause by their fully-qualified name.Fix excessive GC overhead caused by large arrays and maps containing
VARCHAR
elements.Improve error handling when passing too many arguments to various functions or operators that take a variable number of arguments.
Improve performance of
count(*)
aggregations over subqueries with known constant cardinality.Add
VERBOSE
option for EXPLAIN ANALYZE that provides additional low-level details about query performance.Add per-task distribution information to the output of
EXPLAIN ANALYZE
.Add support for
DROP COLUMN
in ALTER TABLE.Change local scheduler to prevent starvation of long running queries when the cluster is under constant load from short queries. The new behavior is disabled by default and can be enabled by setting the config property
task.level-absolute-priority=true
.Improve the fairness of the local scheduler such that long-running queries which spend more time on the CPU per scheduling quanta (e.g., due to slow connectors) do not get a disproportionate share of CPU. The new behavior is disabled by default and can be enabled by setting the config property
task.legacy-scheduling-behavior=false
.Add a config option to control the prioritization of queries based on elapsed scheduled time. The
task.level-time-multiplier
property controls the target scheduled time of a level relative to the next level. Higher values for this property increase the fraction of CPU that will be allocated to shorter queries. This config property only has an effect whentask.level-absolute-priority=true
andtask.legacy-scheduling-behavior=false
.
Hive#
Fix potential native memory leak when writing tables using RCFile.
Correctly categorize certain errors when writing tables using RCFile.
Decrease the number of file system metadata calls when reading tables.
Add support for dropping columns.
JDBC driver#
Add support for query cancellation using
Statement.cancel()
.
PostgreSQL#
Add support for operations on external tables.
Accumulo#
Improve query performance by scanning index ranges in parallel.
SPI#
Fix regression that broke serialization for
SchemaTableName
.Add access control check for
DROP COLUMN
.