Release 0.201#
General#
Change grouped aggregations to use
IS NOT DISTINCT FROM
semantics rather than equality semantics. This fixes incorrect results and degraded performance when grouping onNaN
floating point values, and adds support for grouping on structural types that contain nulls.Fix planning error when column names are reused in
ORDER BY
query.System memory pool is now unused by default and it will eventually be removed completely. All memory allocations will now be served from the general/user memory pool. The old behavior can be restored with the
deprecated.legacy-system-pool-enabled
config option.Improve performance and memory usage for queries using
row_number()
followed by a filter on the row numbers generated.Improve performance and memory usage for queries using
ORDER BY
followed by aLIMIT
.Improve performance of queries that process structural types and contain joins, aggregations, or table writes.
Add session property
prefer-partial-aggregation
to allow users to disable partial aggregations for queries that do not benefit.Add support for
current_user
(see Функции получения информации о сессии).
Security#
Change rules in the Обзор контроля доступа в CedrusData for enforcing matches between authentication credentials and a chosen username to allow more fine-grained control and ability to define superuser-like credentials.
Hive#
Replace ORC writer stripe minimum row configuration
hive.orc.writer.stripe-min-rows
with stripe minimum data sizehive.orc.writer.stripe-min-size
.Change ORC writer validation configuration
hive.orc.writer.validate
to switch to a sampling percentagehive.orc.writer.validation-percentage
.Fix optimized ORC writer writing incorrect data of type
map
orarray
.Fix
SHOW PARTITIONS
and the$partitions
table for tables that have null partition values.Fix impersonation for the simple HDFS authentication to use login user rather than current user.
SPI#
Support resource group selection based on resource estimates.