Presto 0.182 发布了,Presto 是 Facebook 开源的数据查询引擎,可对250PB以上的数据进行快速地交互式分析,查询的速度达到商业数据仓库的级别。据称该引擎的性能是 Hive 的 10 倍以上。
Presto 可以查询包括 Hive、Cassandra 甚至是一些商业的数据存储产品。单个 Presto 查询可合并来自多个数据源的数据进行统一分析。
更新如下:
General Changes
Fix correctness issue that causes :func:`corr` to return positive numbers for inverse correlations.
Fix the :doc:`/sql/explain` query plan for tables that are partitioned on TIMESTAMP or DATE columns.
Fix query failure when when using certain window functions that take arrays or maps as arguments (e.g., :func:`approx_percentile`).
Implement subtraction for all TIME and TIMESTAMP types.
Improve planning performance for queries that join multiple tables with a large number columns.
Improve the performance of joins with only non-equality conditions by using a nested loops join instead of a hash join.
Improve the performance of casting from JSON to ARRAY or MAP types.
Add a new :ref:`ipaddress_type` type to represent IP addresses.
Add :func:`to_milliseconds` function to convert intervals (day to second) to milliseconds.
Add support for column aliases in CREATE TABLE AS statements.
Add a config option to reject queries during cluster initialization. Queries are rejected if the active worker count is less than the query-manager.initialization-required-workers property while the coordinator has been running for less than query-manager.initialization-timeout.
Add :doc:`/connector/tpcds`. This connector provides a set of schemas to support the TPC Benchmark™ DS (TPC-DS).
CLI Changes
Fix an issue that would sometimes prevent queries from being cancelled when exiting from the pager.
Hive Changes
Fix reading decimal values in the optimized Parquet reader when they are backed by the int32 or int64 types.
Add a new experimental ORC writer implementation optimized for Presto. We have some upcoming improvements, so we recommend waiting a few releases before using this in production. The new writer can be enabled with the hive.orc.optimized-writer.enabled configuration property or with the orc_optimized_writer_enabled session property.