Bug: PrquetRowConverter does not follow case sensitivity
Status: Resolved | Priority: Blocker | Resolution: Fixed
Created: 11/Mar/20 07:16
Affects Version/s: 3.0.0

After upgrading spark versrion to 3.0.0-SNAPSHOT. Selecting parquet columns got exception in case insensitive manner. Even we set spark.sql.caseSensitive to false. Reading parquet with case ignored schema (which means columns in parquet and catalyst types are same with respect to case insensitive manner)

 

To reproduce error executing follow code cause java.lang.IllegalArgumentException

 
{code:java}
import org.apache.spark.sql.types._
val path = "/some/temp/path"

spark
  .range(1L)
  .selectExpr("NAMED_STRUCT('lowercase', id, 'camelCase', id + 1) AS StructColumn")
  .write.parquet(path)

val caseInsensitiveSchema = new StructType()
  .add(
    "StructColumn",
    new StructType()
      .add("LowerCase", LongType)
      .add("camelcase", LongType))

spark.read.schema(caseInsensitiveSchema).parquet(path).show(){code}
Then we got following error.


{code:java}
23:57:09.077 ERROR org.apache.spark.executor.Executor: Exception in task 0.0 in stage 215.0 (TID 366)23:57:09.077 ERROR org.apache.spark.executor.Executor: Exception in task 0.0 in stage 215.0 (TID 366)java.lang.IllegalArgumentException: lowercase does not exist. Available: LowerCase, camelcase at org.apache.spark.sql.types.StructType.$anonfun$fieldIndex$1(StructType.scala:306) at scala.collection.immutable.Map$Map2.getOrElse(Map.scala:147) at org.apache.spark.sql.types.StructType.fieldIndex(StructType.scala:305) at org.apache.spark.sql.execution.datasources.parquet.ParquetRowConverter.$anonfun$fieldConverters$1(ParquetRowConverter.scala:182) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:62) at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:55) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:49) at scala.collection.TraversableLike.map(TraversableLike.scala:238) at scala.collection.TraversableLike.map$(TraversableLike.scala:231) at scala.collection.AbstractTraversable.map(Traversable.scala:108) at org.apache.spark.sql.execution.datasources.parquet.ParquetRowConverter.<init>(ParquetRowConverter.scala:181) at org.apache.spark.sql.execution.datasources.parquet.ParquetRowConverter.org$apache$spark$sql$execution$datasources$parquet$ParquetRowConverter$$newConverter(ParquetRowConverter.scala:351) at org.apache.spark.sql.execution.datasources.parquet.ParquetRowConverter.$anonfun$fieldConverters$1(ParquetRowConverter.scala:185) at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:238) at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:62) at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:55) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:49) at scala.collection.TraversableLike.map(TraversableLike.scala:238) at scala.collection.TraversableLike.map$(TraversableLike.scala:231) at scala.collection.AbstractTraversable.map(Traversable.scala:108) at org.apache.spark.sql.execution.datasources.parquet.ParquetRowConverter.<init>(ParquetRowConverter.scala:181) at org.apache.spark.sql.execution.datasources.parquet.ParquetRecordMaterializer.<init>(ParquetRecordMaterializer.scala:43) at org.apache.spark.sql.execution.datasources.parquet.ParquetReadSupport.prepareForRead(ParquetReadSupport.scala:130) at org.apache.parquet.hadoop.InternalParquetRecordReader.initialize(InternalParquetRecordReader.java:204) at org.apache.parquet.hadoop.ParquetRecordReader.initializeInternalReader(ParquetRecordReader.java:182) at org.apache.parquet.hadoop.ParquetRecordReader.initialize(ParquetRecordReader.java:140) at org.apache.spark.sql.execution.datasources.parquet.ParquetFileFormat.$anonfun$buildReaderWithPartitionValues$2(ParquetFileFormat.scala:341) at org.apache.spark.sql.execution.datasources.FileScanRDD$$anon$1.org$apache$spark$sql$execution$datasources$FileScanRDD$$anon$$readCurrentFile(FileScanRDD.scala:116) at org.apache.spark.sql.execution.datasources.FileScanRDD$$anon$1.nextIterator(FileScanRDD.scala:169) at org.apache.spark.sql.execution.datasources.FileScanRDD$$anon$1.hasNext(FileScanRDD.scala:93) at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:458) at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:458) at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:458) at org.apache.spark.util.Utils$.getIteratorSize(Utils.scala:1804) at org.apache.spark.rdd.RDD.$anonfun$count$1(RDD.scala:1229) at org.apache.spark.rdd.RDD.$anonfun$count$1$adapted(RDD.scala:1229) at org.apache.spark.SparkContext.$anonfun$runJob$5(SparkContext.scala:2144) at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:90) at org.apache.spark.scheduler.Task.run(Task.scala:127) at org.apache.spark.executor.Executor$TaskRunner.$anonfun$run$3(Executor.scala:460) at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1377) at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:463) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)


{code}
 

I think from 3.0.0, `org.apache.spark.sql.execution.datasources.parquet.ParquetRowConverter` does not have equal number of fields between parquetRequestedSchema and catalystRequestedSchema ([https://github.com/apache/spark/pull/22880]). So we consider case sensitivity in ParquetRowConverter or some related classes.