UrV*_*Val 5 scala spark-dataframe
我有 2 个具有以下架构的数据框:
root
|-- pid: long (nullable = true)
|-- lv: timestamp (nullable = true)
root
|-- m_pid: long (nullable = true)
|-- vp: double (nullable = true)
|-- created: timestamp (nullable = true)
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如果我尝试显示()这两个数据帧中的任何一个,一切正常,则会显示前 20 行。如果我尝试加入这 2 个数据框并显示结果(连接转换时不会出现错误,仅在调用“显示”操作时)
var joined = df1.join(df2, df2("pid") === df1("m_pid")).drop("m_pid")
joined.show()
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我收到一个我不明白的错误。它与镶木地板有关。其中一个数据帧是从镶木地板中读取的(另一个是从文本中读取的),但是如果这是与读取数据相关的问题,那么为什么只有在加入数据帧时才会出现问题,而不是在单独显示时才出现问题。
错误是:
org.apache.spark.SparkException: Job aborted due to stage failure: Task 51 in stage 403.0 failed 4 times, most recent failure: Lost task 51.3 in stage 403.0 : java.lang.UnsupportedOperationException: org.apache.parquet.column.values.dictionary.PlainValuesDictionary$PlainLongDictionary
...
Caused by: java.lang.UnsupportedOperationException: org.apache.parquet.column.values.dictionary.PlainValuesDictionary$PlainLongDictionary
at org.apache.parquet.column.Dictionary.decodeToDouble(Dictionary.java:60)
at org.apache.spark.sql.execution.vectorized.OnHeapColumnVector.getDouble(OnHeapColumnVector.java:354)
at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIterator.processNext(Unknown Source)
at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
at org.apache.spark.sql.execution.WholeStageCodegenExec$$anonfun$8$$anon$1.hasNext(WholeStageCodegenExec.scala:370)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:408)
at org.apache.spark.shuffle.sort.BypassMergeSortShuffleWriter.write(BypassMergeSortShuffleWriter.java:147)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:79)
at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:47)
at org.apache.spark.scheduler.Task.run(Task.scala:85)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:274)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
... 1 more
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有没有人知道导致错误的原因以及如何解决它?