新特性版本Impala各版本新特性
新手发帖，很多方面都是刚入门，有错误的地方请大家见谅，欢迎批评指正
自0.3以后的重点新特性
1.0
· 支撑ALTER TABLE。
· 支撑通过Hints指定join策略。支撑的Hints：
o [broadcast]：broadcast join策略（将小表放到全部节点上与大表停止分片join）
o [shuffle]： partitionedjoin策略（分片join）
· 支撑刷新单个表的元数据。元数据的自动刷新仍然不支撑。
· 动态资源管理，允许高并发的查询。
0.7
· 支撑Parquet文件格式。Parquet是列存储的格式，对查询特别是面向列的查询性能提升有非常大的提升。
· 支撑内存制约。之前Impala进程对内存应用没有制约，会造成节点内存耗尽。
· 通过供给broadcast join供给更大和更快的join。
· 完全分布式的聚合（aggregations）计算。之前的计算须要全部数据拖到一个节点上停止聚合处理。
· 完全分布式的top计算。之前的计算须要全部数据拖到一个节点上停止top处理。
· 支撑创建和修改表。
· 支撑对floats和doubles 的GROUP BY。
0.6.
· 支撑SUSE和Debian/Ubuntu，目前支撑以下OS：
o RHEL5.7/6.2 and Centos5.7/6.2
o SUSE 11 with Service Pack 1 or later
o Ubuntu 10.04/12.04 and Debian 6.03
· 支撑RCFile文件格式。
0.5
· 添加JDBC驱动，运行用户从java客户端拜访Impala。
附录：Impala各版本新特性历史
New Features inImpala
Impala contains the following changesand enhancements from previous releases.
New Features in Impala Version 1.0
This version has multiple performance improvementsand adds the following functionality:
· Several bug fixes. See KnownIssues Fixed in the 1.0 GA Release.
· ALTER TABLE statement.
· Hints to allow specifying a particularjoin strategy.
· REFRESH for a single table.
· Dynamic resource management, allowing high concurrencyfor Impala queries.
New Features in Version 0.7 of theCloudera Impala Beta Release
This version has multiple performanceimprovements and adds the following functionality:
· Several bug fixes. See KnownIssues Fixed in Version 0.7 of the Beta Release.
· Support for the Parquet file format. For more informationon file formats, see UnderstandingFile Formats.
· Support for the memory limits. For more information, seethe example on modifying memory limits in ModifyingImpala Startup Options.
· Bigger and faster joins through the addition ofpartitioned joins to the already supported broadcast joins.
· Fully distributed aggregations.
· Fully distributed top-n computation.
· Support for creating and altering tables.
· Support for GROUP BY with floats and doubles.
In this version, both CDH4.1 and 4.2 aresupported, but due to performance improvements added, we highly recommend youuse CDH4.2 to see the full benefit. If you are using Cloudera Manager, version4.5 is required.
New Features in Version 0.6 of theCloudera Impala Beta Release
· Several bug fixes. See KnownIssues Fixed in Version 0.6 of the Beta Release.
· Added support for Impala on SUSE and Debian/Ubuntu.Impala is now supported on:
o RHEL5.7/6.2 and Centos5.7/6.2
o SUSE 11 with Service Pack 1 or later
o Ubuntu 10.04/12.04 and Debian 6.03
· Cloudera Manager 4.5 and CDH 4.2 support Impala 0.6.
· Support for the RCFile file format. For more informationon file formats, see UnderstandingFile Formats.
New Features in Version 0.5 of theCloudera Impala Beta Release
· Several bug fixes. See KnownIssues Fixed in Version 0.5 of the Beta Release.
· Added support for a JDBC driver that allows you to accessImpala from a Java client. To use this feature, you must follow theinstructions in ConfiguringImpala to Work with JDBC to install the JDBC driver JARs onthe client machine and modify the classpath on the client to include the JARs.
New Features in Version 0.4 of theCloudera Impala Beta Release
· Several bug fixes. See KnownIssues Fixed in Version 0.4 of the Beta Release.
· Added support for Impala on RHEL5.7/Centos5.7. Impala isnow supported on RHEL5.7/6.2 and Centos5.7/6.2.
· Cloudera Manager 4.1.3 supports Impala 0.4.
· The Impala debug webserver now has the ability to servestatic files from ${IMPALA_HOME}/www. This can be disabled by setting --enable_webserver_doc_root=false on the command line. As a result,Impala now uses the Twitter Bootstrap library to style its debug webpages, andthe /queriespage now tracksthe last 25 queries run by each Impala daemon.
· Additional metrics available on the Impala Debug Webpage.
New Features in Version 0.3 of theCloudera Impala Beta Release
· Several bug fixes. See KnownIssues Fixed in Version 0.3 of the Beta Release.
· The state-store-service binary has been renamed statestored.
· The location of the Impala configuration files haschanged from the /usr/lib/impala/conf directory to the /etc/impala/conf directory.
New Features in Version 0.2 of theCloudera Impala Beta Release
· Several bug fixes. See KnownIssues Fixed in Version 0.2 of the Beta Release.
· Added Default Query Options Default query options override alldefault QueryOption values when starting impalad. The format is:
-default_query_options='key=value;key=value'
文章结束给大家分享下程序员的一些笑话语录： 那是习惯决定的，一直保持一个习惯是不好的！IE6的用户不习惯多标签，但是最终肯定还是得转到多标签的浏览器。历史（软件UI）的进步（改善）不是以个人意志（习惯）为转移的！
--------------------------------- 原创文章 By
新特性和版本
---------------------------------