本文介绍了如何使用spark-cassandra-connector实现LEFT或RIGHT JOIN的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

限时删除!!

我有火花工作.我正在使用Cassandra作为数据存储.我有需要与cassandra表一起加入的流.我正在使用spark-cassandra-connector,有一个很棒的方法 joinWithCassandraTable ,据我所知,用cassandra表实现内部联接

I have spark streaming job. I am using Cassandra as datastore.I have stream which is need to be joined with cassandra table.I am using spark-cassandra-connector, there is great method joinWithCassandraTable which is as far as I can understand implementing inner join with cassandra table

val source: DStream[...] = ...
source.foreachRDD { rdd =>
  rdd.joinWithCassandraTable( "keyspace", "table" ).map{ ...
  }
}

所以问题是如何用cassandra表实现左外部联接?

So the question is how can I implement left outer join with cassandra table?

预先感谢

推荐答案

当前不支持此功能,但是有介绍该功能的票证.如果您希望将来引入它,请对其进行投票.

This is currently not supported, but there is a ticket to introduce the functionality. Please vote on it if you would like it introduced in the future.

https://datastax-oss.atlassian.net/browse/SPARKC-181

故障单中建议一种解决方法

A workaround is suggested in the ticket

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09-06 22:02