直接从 Spark shell 读取 ORC 文件 [英] Read ORC files directly from Spark shell

问题描述

我在直接从 Spark shell 读取 ORC 文件时遇到问题.注意:运行Hadoop 1.2和Spark 1.2，使用pyspark shell，可以使用spark-shell(运行scala).

I am having issues reading an ORC file directly from the Spark shell. Note: running Hadoop 1.2, and Spark 1.2, using pyspark shell, can use spark-shell (runs scala).

我使用过这个资源 http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.2.4/Apache_Spark_Quickstart_v224/content/ch_orc-spark-quickstart.html .

I have used this resource http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.2.4/Apache_Spark_Quickstart_v224/content/ch_orc-spark-quickstart.html .

from pyspark.sql import HiveContext
hiveCtx = HiveContext(sc)

inputRead = sc.hadoopFile("hdfs://user@server:/file_path",
classOf[inputFormat:org.apache.hadoop.hive.ql.io.orc.OrcInputFormat],
classOf[outputFormat:org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat])

我收到一条错误消息，通常说语法错误.有一次，代码似乎有效，我只使用了传递给 hadoopFile 的三个参数中的第一个，但是当我尝试使用

I get an error generally saying wrong syntax. One time, the code seemed to work, I used just the 1st of three arguments passed to hadoopFile, but when I tried to use

inputRead.first()

输出是 RDD[nothing, nothing].我不知道这是因为 inputRead 变量不是作为 RDD 创建的，还是根本没有创建.

the output was RDD[nothing, nothing]. I don't know if this is because the inputRead variable did not get created as an RDD or if it was not created at all.

感谢您的帮助！

推荐答案

在 Spark 1.5 中，我可以将我的 ORC 文件加载为:

In Spark 1.5, I'm able to load my ORC file as:

val orcfile = "hdfs:///ORC_FILE_PATH"
val df = sqlContext.read.format("orc").load(orcfile)
df.show

这篇关于直接从 Spark shell 读取 ORC 文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！