新特性版本Impala各版本新特性

新手發帖，很多方面都是剛入門，有錯誤的地方請大家見諒，歡迎批評指正

    自0.3以後的重點新特性

    1.0

    ·        支撐​​ALTER TABLE​​。

    ·        支撐通過Hints指定join政策。支撐的Hints：

    o    [broadcast]：broadcast join政策（将小表放到全部節點上與大表停止分片join）

    o    [shuffle]：   partitionedjoin政策（分片join）

    ·        支撐重新整理單個表的中繼資料。中繼資料的自動重新整理仍然不支撐。

    ·        動态資源管理，允許高并發的查詢。

    0.7

    ·        支撐Parquet檔案格式。Parquet是列存儲的格式，對查詢特别是面向列的查詢性能提升有非常大的提升。

    ·        支撐Avro。

    ·        支撐記憶體制約。之前Impala程序對記憶體應用沒有制約，會造成節點記憶體耗盡。

    ·        通過供給broadcast join供給更大和更快的join。

    ·        完全分布式的聚合（aggregations）計算。之前的計算須要全部資料拖到一個節點上停止聚合處理。

    ·        完全分布式的top計算。之前的計算須要全部資料拖到一個節點上停止top處理。

    ·        支撐建立和修改表。

    ·        支撐對floats和doubles 的GROUP BY。

    0.6.

    ·        支撐SUSE和Debian/Ubuntu，目前支撐以下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

    ·        支撐RCFile檔案格式。

    0.5

    ·        添加JDBC驅動，運作使用者從java用戶端拜訪Impala。

    附錄：Impala各版本新特性曆史

    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​​.

    ·        Added support for Avro.

    每日一道理

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    ·        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:

    ·        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'

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新特性和版本