Spark 1.3.0
Two issues:
a) I'm unable to get a "lateral view explode" query to work on an array type
b) I'm unable to save an array type to a Parquet file
I keep running into this:
java.lang.ClassCastException: [I cannot be cast to
scala.collection.Seq
Here's a stack trace from the explode issue:
root
|-- col1: string (nullable = false)
|-- col2s: array (nullable = true)
| |-- element: integer (containsNull = true)
ERROR org.apache.spark.executor.Executor Exception in task 7.0 in stage 1.0
(TID 15)
java.lang.ClassCastException: [I cannot be cast to scala.collection.Seq
at
org.apache.spark.sql.catalyst.expressions.Explode.eval(generators.scala:125)
~[spark-catalyst_2.10-1.3.0.jar:1.3.0]
at
org.apache.spark.sql.execution.Generate$$anonfun$2$$anonfun$apply$1.apply(Generate.scala:70)
~[spark-sql_2.10-1.3.0.jar:1.3.0]
at
org.apache.spark.sql.execution.Generate$$anonfun$2$$anonfun$apply$1.apply(Generate.scala:69)
~[spark-sql_2.10-1.3.0.jar:1.3.0]
at scala.collection.Iterator$$anon$13.hasNext(Iterator.scala:371)
~[scala-library-2.10.4.jar:na]
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
~[scala-library-2.10.4.jar:na]
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
~[scala-library-2.10.4.jar:na]
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
~[scala-library-2.10.4.jar:na]
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
~[scala-library-2.10.4.jar:na]
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
~[scala-library-2.10.4.jar:na]
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
~[scala-library-2.10.4.jar:na]
at
scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
~[scala-library-2.10.4.jar:na]
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
~[scala-library-2.10.4.jar:na]
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
~[scala-library-2.10.4.jar:na]
at scala.collection.AbstractIterator.to(Iterator.scala:1157)
~[scala-library-2.10.4.jar:na]
at
scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
~[scala-library-2.10.4.jar:na]
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
~[scala-library-2.10.4.jar:na]
at
scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
~[scala-library-2.10.4.jar:na]
at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
~[scala-library-2.10.4.jar:na]
at org.apache.spark.rdd.RDD$$anonfun$17.apply(RDD.scala:813)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at org.apache.spark.rdd.RDD$$anonfun$17.apply(RDD.scala:813)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at
org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1497)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at
org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1497)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:61)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at org.apache.spark.scheduler.Task.run(Task.scala:64)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:203)
~[spark-core_2.10-1.3.0.jar:1.3.0]
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
[na:1.8.0_31]
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
[na:1.8.0_31]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_31]
WARN o.a.spark.scheduler.TaskSetManager Lost task 7.0 in stage 1.0 (TID
15, localhost): java.lang.ClassCastException: [I cannot be cast to
scala.collection.Seq
at
org.apache.spark.sql.catalyst.expressions.Explode.eval(generators.scala:125)
at
org.apache.spark.sql.execution.Generate$$anonfun$2$$anonfun$apply$1.apply(Generate.scala:70)
at
org.apache.spark.sql.execution.Generate$$anonfun$2$$anonfun$apply$1.apply(Generate.scala:69)
at scala.collection.Iterator$$anon$13.hasNext(Iterator.scala:371)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103)
at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47)
at scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273)
at scala.collection.AbstractIterator.to(Iterator.scala:1157)
at
scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265)
at scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157)
at scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252)
at scala.collection.AbstractIterator.toArray(Iterator.scala:1157)
at org.apache.spark.rdd.RDD$$anonfun$17.apply(RDD.scala:813)
at org.apache.spark.rdd.RDD$$anonfun$17.apply(RDD.scala:813)
at
org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1497)
at
org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1497)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:61)
at org.apache.spark.scheduler.Task.run(Task.scala:64)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:203)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Maybe I'm defining the schema incorrectly?
This test demonstrates both issues:
@Rule
public TemporaryFolder tmp = new TemporaryFolder();
@Test
public void testPercentileWithExplode() throws Exception {
StructType schema = DataTypes.createStructType(Lists.newArrayList(
DataTypes.createStructField("col1", DataTypes.StringType,
false),
DataTypes.createStructField("col2s",
DataTypes.createArrayType(DataTypes.IntegerType, true), true)
));
JavaRDD<Row> rowRDD = sc.parallelize(Lists.newArrayList(
RowFactory.create("test", new int[]{1, 2, 3})
));
DataFrame df = sql.createDataFrame(rowRDD, schema);
df.registerTempTable("df");
df.printSchema();
List<int[]> ints = sql.sql("select col2s from df").javaRDD()
.map(row -> (int[]) row.get(0)).collect();
assertEquals(1, ints.size());
assertArrayEquals(new int[]{1, 2, 3}, ints.get(0));
// fails: lateral view explode does not work:
java.lang.ClassCastException: [I cannot be cast to scala.collection.Seq
List<Integer> explodedInts = sql.sql("select col2 from df lateral
view explode(col2s) splode as col2").javaRDD()
.map(row ->
row.getInt(0)).collect();
assertEquals(3, explodedInts.size());
assertEquals(Lists.newArrayList(1, 2, 3), explodedInts);
// fails: java.lang.ClassCastException: [I cannot be cast to
scala.collection.Seq
df.saveAsParquetFile(tmp.getRoot().getAbsolutePath() + "/parquet");
DataFrame loadedDf = sql.load(tmp.getRoot().getAbsolutePath() +
"/parquet");
loadedDf.registerTempTable("loadedDf");
List<int[]> moreInts = sql.sql("select col2s from
loadedDf").javaRDD()
.map(row -> (int[]) row.get(0)).collect();
assertEquals(1, moreInts.size());
assertArrayEquals(new int[]{1, 2, 3}, moreInts.get(0));
}
