hadoop学习案例的相关内容

文章 2023-01-17 来自：开发者社区

Hadoop学习：MapReduce实现WordCount经典案例

一、✌题目要求> 统计文本中每个单词的数量二、✌实现思想> Map阶段默认输入为TextInputFormat，键值对对应为行的偏移量和每行的文本内容 > 在map函数中将每行文本进行切分，提取出每个单词 > 在Reduce阶段根据相同Key值进行累加求和 > 三、✌代码实现1.✌Map类public class WordCountMapper extends Ma....

文章 2017-11-20 来自：开发者社区

Hadoop Hive概念学习系列之hive的索引及案例（八）

hive里的索引是什么？　　索引是标准的数据库技术，hive 0.7版本之后支持索引。Hive提供有限的索引功能，这不像传统的关系型数据库那样有“键(key)”的概念，用户可以在某些列上创建索引来加速某些操作，给一个表创建的索引数据被保存在另外的表中。 Hive的索引功能现在还相对较晚，提供的选项还较少。但是，索引被设计为可使用内置的可插拔的java代码来定制，用户可以扩展这个功能来满足自己的....

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开源大数据平台 E-MapReduce

开源大数据平台 E-MapReduce（简称“EMR”）是云原生开源大数据平台，向客户提供简单易集成的Hadoop、Hive、Spark、Flink、Presto、ClickHouse、StarRocks、Delta、Hudi等开源大数据计算和存储引擎服务。

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