Read ORC files directly from Spark shell

问题:

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).

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])

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()

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.

I appreciate any help!

回答1:

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

回答2:

You can try this code, it's working for me.

val LoadOrc = spark.read.option("inferSchema", true).orc("filepath")
LoadOrc.show()

回答3:

you can also add the multiple path to read from

val df = sqlContext.read.format("orc").load("hdfs://localhost:8020/user/aks/input1/*","hdfs://localhost:8020/aks/input2/*/part-r-*.orc")